Crohn's Disease: in Defense of a Microvascular Aetiology

International Journal of Colorectal Disease. Sep, 2002  |  Pubmed ID: 12172921

BACKGROUND AND AIMS: There appears little doubt that microvascular ischaemia is involved in Crohn's disease. Studies have consistently demonstrated that the number of blood vessels and the total volume of blood feeding segments of bowel with Crohn's disease are reduced. However, the aetiology of the microvascular ischaemia is yet to be determined. Potential aetiological factors that appear to be disease specific include increased mesenteric platelet aggregation and increased platelet surface expression of P-selectin and GP53. However, there are several other factors known to be raised in active and quiescent disease for which disease specificity is not yet known, including increased submucosal endothelial endothelin-1 receptor expression, increased m RNA expression for several interleukins and cytokines including TNFalpha, increased PAF and thrombomodulin and finally altered cellular adhesion molecule expression. CONCLUSION: Proving cause and effect will always be a difficult task given the self-perpetuating nature of the inflammatory and coagulation cascades and our inability at present to identify persons who subsequently develop Crohn's disease at a point prior to mucosal inflammation. Results to date however, are supportive of each of these factors, alone or in combination playing an integral part in the development of microvascular ischaemia, a pathological process which appears to precede the classic changes which characterize Crohn's disease.

Long-term Outcomes of Pelvic Floor Exercise and Biofeedback Treatment for Patients with Fecal Incontinence

Diseases of the Colon and Rectum. Aug, 2002  |  Pubmed ID: 12195181

The aim of this study was to assess the long-term clinical and quality of life outcomes for patients after referral to a four-month treatment program for fecal incontinence based on pelvic floor exercises and biofeedback. Secondary objectives were to document patients' subsequent treatment activities and their perception of the biofeedback training; to establish the long-term outcomes and initial predictors for the subset of patients who did not complete the treatment, or who failed to improve during the program; and to correlate changes in clinical outcome measures and quality of life over time.

Appendectomy Protects Against the Development of Ulcerative Colitis but Does Not Affect Its Course

The American Journal of Gastroenterology. Nov, 2002  |  Pubmed ID: 12425556

Appendectomy has been shown to protect against the development of ulcerative colitis. The objective of this study was to examine the effect of appendectomy on the clinical features and natural history of colitis.

Assessment of Quality of Life in the Treatment of Patients with Neuropathic Fecal Incontinence

Diseases of the Colon and Rectum. Nov, 2002  |  Pubmed ID: 12432287

Development of quality-of-life measures has been the focus of research in colorectal disorders in recent years. The assessment of quality of life for fecal incontinence should be more important than quantitative measurement of soiling.

Management of Patients with Colorectal Cancer: Do Australian Surgeons Know the Scientific Evidence?

Archives of Surgery (Chicago, Ill. : 1960). Dec, 2002  |  Pubmed ID: 12470106

Not all Australian surgeons are aware of the status of the current evidence for the management of colorectal cancer.

Acute Malignant Colorectal Obstruction and Self-expandable Metallic Stents

ANZ Journal of Surgery. Dec, 2002  |  Pubmed ID: 12485215

Probe Size Effects on the Microrheology of Associating Polymer Solutions

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Dec, 2002  |  Pubmed ID: 12513289

Diffusing wave spectroscopy has been used to investigate the thermally driven displacement of colloidal particles dispersed in solutions of associating polymers (APs). The effect of varying colloidal probe size on the measured particle displacements is studied in particular. Recent theories of microrheology are examined in light of the observed effects. The associating polymer used in this research was a linear polyethylene oxide (PEO) chain (molecular weight 35 000 g/mole) with a Cl14 aliphatic group appended to each end of the PEO. Above a critical concentration, the associating polymers display linear viscoelasticity consistent with the Maxwell model. The concentration of aqueous AP solutions was varied from 0.25 to 4.0 wt. %. At low concentration of APs, the mean square displacement of the colloidal beads was indistinguishable from simple Brownian diffusion in the aqueous solvent. However, at concentrations greater than 0.5 wt. %, the mean square displacement differed from simple diffusion in a way that was found to be consistent with the Maxwell model linear viscoelasticity (LVE) of the AP solutions. Significantly, for the most concentrated solutions, as the probe particle size was varied from 0.3 to 2.2 microm, the observed mean square displacement deviated substantially from the generalized Stokes-Einstein behavior predicted by microrheological theories. Our experiments showed that these deviations could not be attributed to specific physicochemical interactions at the probe-matrix interface, since observed mean square displacements were independent of different probe surface chemistries studied. Moreover, this particle size effect was not observed in semidilute, high molecular weight PEO solutions (molecular weight 4.0 x 10(6) g/mole). We concluded that possible effects of AP network compressibility and AP depletion at the probe surface could not account for the observed particle size effects. We examined recent reports of the structural heterogeneity in AP solutions for their possible connection to our observation of the breakdown of the generalized Stokes-Einstein equation for this system. Numerical conversion of the microscopic results to the linear viscoelastic moduli, G'(omega) and G"(omega), by means of a constrained regularization method (CONTIN), demonstrates that the experiments with larger probe particles are most consistent with the single-mode Maxwell model LVE observed by macroscopic mechanical rheology.

P53, Deleted in Colorectal Cancer Gene, and Thymidylate Synthase As Predictors of Histopathologic Response and Survival in Low, Locally Advanced Rectal Cancer Treated with Preoperative Adjuvant Therapy

Diseases of the Colon and Rectum. Feb, 2003  |  Pubmed ID: 12576893

Adjuvant therapy, either preoperatively or postoperatively, and modifications of surgery have been used to try to improve outcome of surgery for rectal cancer in regard to both local recurrence and survival. Assessment of prognosis in patients after resection is currently primarily based on clinicopathologic factors. These predict the subsequent behavior of the tumor only imperfectly. The aim of this study was to evaluate three potential molecular genetic markers of prognosis (p53, deleted in colorectal cancer gene, and thymidylate synthase) in Dukes Stage B and C low rectal tumors treated with adjuvant therapy and to determine whether they correlate with survival, local recurrence, or the pathologic response to adjuvant therapy (assessed by extent of tumor regression and tumor down-staging).

Measuring the Importance of Attributes That Influence Consumer Attitudes to Colorectal Cancer Screening

ANZ Journal of Surgery. Mar, 2003  |  Pubmed ID: 12608975

The aim of the present study was to rate the importance of attributes of screening for bowel cancer.

The Gist of It: Case Reports of a Gastrointestinal Stromal Tumour and a Leiomyoma of the Anorectum

ANZ Journal of Surgery. Mar, 2003  |  Pubmed ID: 12608988

Self-diffusion in Dilute Colloidal Suspensions with Attractive Potential Interactions

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. May, 2003  |  Pubmed ID: 12786122

The colloidal short-time self-diffusivity D(s)(s)(phi) is significantly retarded relative to hard sphere suspensions for the case of interparticle potential interactions induced by a nonadsorbing polymer. A comparison of diffusing wave spectroscopy measurements with direct calculations of D(s)(s)(phi) demonstrates that depletion effects on structure explain the observed retardation. We show that coexistence boundaries place unexpectedly severe constraints on the amount of D(s)(s)(phi) retardation possible for stable suspensions. The measured retardation is demonstrated to be an indicator of suspension metastability.

Randomized, Controlled Trial of Biofeedback with Anal Manometry, Transanal Ultrasound, or Pelvic Floor Retraining with Digital Guidance Alone in the Treatment of Mild to Moderate Fecal Incontinence

Diseases of the Colon and Rectum. Jun, 2003  |  Pubmed ID: 12794569

A prospective, three-armed, randomized, controlled trial was performed to assess whether pelvic floor exercises with biofeedback using anal manometry or transanal ultrasound are superior to pelvic floor exercises with feedback from digital examination alone in terms of continence, quality of life, physiologic sphincter strength, and compliance. Its secondary objectives were to assess whether there are any differences in these outcomes between biofeedback with transanal ultrasound vs. anal manometry and to correlate the physiologic measures with clinical outcome.

Patient Entry into Randomized Controlled Trials of Colorectal Cancer Treatment: Factors Influencing Participation

Surgery. Jun, 2003  |  Pubmed ID: 12796726

The objective of this study was to investigate willingness to participate in hypothetical surgical randomized controlled trials (RCTs) among patients and clinicians, who answered as if they themselves were patients.

An Economic Perspective on Evidence-based Patient Choice in Surgery

ANZ Journal of Surgery. Jun, 2003  |  Pubmed ID: 12801343

The aim of the present paper is to provide an economic perspective on current and emerging issues relating to surgical decision-making. The central issue discussed in the paper is choice and how this relates to patient management. The paper explores three factors that may influence the nature of choice; they are--evidence-based medicine, patient involvement in making choices and the role of cost-effectiveness analysis in surgery. Together, these factors are driving a shift from the traditional model of care based on medical beneficence to one based more on individual patient autonomy. This shift has been described as a move towards 'evidence-based patient choice' (EBPC). The concept of EBPC is relatively new and ill defined. Yet it encapsulates what is happening now and what will occur more dramatically in the future; that is, the nature of the relationship between surgeon and patient is changing. We hope that this paper will provoke discussion on the concept of EBPC and cost-effectiveness analysis in surgical decision-making.

Improving the Evidence Base in Surgery: Sources of Bias in Surgical Studies

ANZ Journal of Surgery. Jul, 2003  |  Pubmed ID: 12864825

Clinical epidemiology, which is concerned with the application of epidemiological principles to patient care, provides the scientific basis for evidence-based medicine. The present paper reviews the epidemiological concepts of selection bias, measurement bias and confounding in surgical research and discusses ways in which these sources of bias can be minimized in surgical studies.

Improving the Evidence-base in Surgery: Evaluating Surgical Effectiveness

ANZ Journal of Surgery. Jul, 2003  |  Pubmed ID: 12864826

This second of two articles about clinical epidemiology reviews the generation and synthesis of evidence for the effectiveness of surgical procedures. While well-designed randomized controlled trials of surgical procedures are considered the 'gold standard' of evaluation design, they may achieve high internal validity at the expense of external validity (generalizability). Improving the -evidence-base in surgery likely will require a comprehensive approach to surgical outcomes assessment, involving both improvements in the quality and quantity of randomized controlled trials as well as recognition of the complementary role of alternate study designs.

What Do Patients Want? Patient Preferences and Surrogate Decision Making in the Treatment of Colorectal Cancer

Diseases of the Colon and Rectum. Oct, 2003  |  Pubmed ID: 14530674

Clinicians often make decisions for their patients, despite evidence that suggests that correspondence between patient and clinician decision making is poor. The management of colorectal cancer presents difficult decisions because the impact of treatment on quality of life might overshadow its survival efficacy. This study investigated whether patients are able to trade survival for quality of life as a means to express their preference for treatment options and to compare their preferences with those expressed by clinicians.

Cholecystectomy in Patients with Crohn's Ileitis

Diseases of the Colon and Rectum. Nov, 2003  |  Pubmed ID: 14605566

Gallstone disease is reported to be higher in patients with Crohn's disease than in the general population. This study was designed to determine the prevalence of cholecystectomy in patients with Crohn's ileitis, attempt to identify any associated risk factors, and determine whether it is justified to perform prophylactic cholecystectomy during ileocolic resection.

Laparoscopic Versus Open Ileocolic Resection for Crohn's Disease

Journal of Laparoendoscopic & Advanced Surgical Techniques. Part A. Apr, 2004  |  Pubmed ID: 15107212

Laparoscopic ileocolic (LI) resection for Crohn's disease has several potential advantages over the traditional open technique. The objective of this study was to compare early surgical outcomes in patients having laparoscopic versus open ileocolic resections for Crohn's disease.

Effect of Monomer Geometry on the Fractal Structure of Colloidal Rod Aggregates

Physical Review Letters. Apr, 2004  |  Pubmed ID: 15169295

The fractal structure of clusters formed by diffusion-limited aggregation of rodlike particles is characterized over three decades of the scattering vector q, and displays an unexpected dependence on the aspect ratio of the constituent monomers. Monte Carlo simulations of aggregating Brownian rods corroborate the experimental finding that the measured fractal dimension is an increasing function of the monomer aspect ratio. Moreover, increasing the rod aspect ratio eliminates the structural distinction between diffusion- and reaction-limited cluster aggregation that is observed for spheres.

Free Colorectal Cancer Cells on the Peritoneal Surface: Correlation with Pathologic Variables and Survival

Diseases of the Colon and Rectum. Dec, 2004  |  Pubmed ID: 15657657

Clinicopathologic staging of colorectal cancer remains the best predictor of survival. Prognostication for an individual with colorectal cancer remains elusive. This study was designed to investigate the incidence of free surface colorectal cancer cells detected by cytology during elective open curative resection, to correlate their presence with particular clinicopathologic variables and determine whether their presence was predictive of cancer-specific survival.

Long-term Indwelling Seton for Complex Anal Fistulas in Crohn's Disease

Diseases of the Colon and Rectum. Mar, 2005  |  Pubmed ID: 15719188

This study was designed to review the results of long-term indwelling seton or depezzar catheter in the management of perianal Crohn's disease.

Direct Visualization of Colloidal Rod Assembly by Confocal Microscopy

Langmuir : the ACS Journal of Surfaces and Colloids. Jun, 2005  |  Pubmed ID: 15924453

The development of model materials and image processing methods to directly visualize and quantify colloidal rod assembly by means of confocal laser scanning microscopy (CLSM) is reported. Monodisperse fluorescent colloidal rods are prepared by the uniaxial extensional deformation of sterically stabilized microspheres at elevated temperatures. The particles are stably dispersed in refractive index matching mixed organic solvents for CLSM. An image processing algorithm is developed to detect rod backbones and extract particle centroids and orientation angles from the CLSM image volumes. By means of these methods we quantify the distribution of rod orientation angles in self-assembled structures of rods formed by sedimentation. We find the observations to be consistent with aspect-ratio-dependent jamming and orientational order/disorder transition in the rod sediments.

Telephone Vs. Face-to-face Biofeedback for Fecal Incontinence: Comparison of Two Techniques in 239 Patients

Diseases of the Colon and Rectum. Dec, 2005  |  Pubmed ID: 16258709

Biofeedback is an effective treatment for patients with fecal incontinence, yet little is known about how it works or the minimum regime necessary to provide clinical benefit. This study compares the effectiveness of a novel protocol of telephone-assisted biofeedback treatment for patients living in rural and remote areas with the standard face-to-face protocol for patients with fecal incontinence.

Is It Worth the Risk? A Systematic Review of Instruments That Measure Risk Propensity for Use in the Health Setting

Social Science & Medicine (1982). Mar, 2005  |  Pubmed ID: 15626532

In this era of shared doctor-patient decision-making, eliciting and incorporating patients' treatment choices is essential to ensure all patients receive the treatment that is right for them. Clinicians and researchers should fully understand the many factors that influence and guide patients in their preferences for treatment. One of these influences is an individual's general risk propensity or willingness to take risks, yet there is little in the literature about methods for measuring risk propensity. A systematic review was undertaken to identify instruments that measure risk propensity and to appraise their validity and relevance for a clinical setting. Of 3546 articles, 139 were potentially relevant. From these, 14 instruments were identified. Eight measured risk propensity, whereas six measured personality traits associated with risk propensity. Most instruments demonstrated good internal reliability but their appropriateness for patients, particularly older adults, remains unclear. While no instrument was specific to or tested in a clinical setting, instruments that directly measured risk propensity were considered to be the most useful for clinical populations. The further adaptation and validation of these instruments among older adults are important avenues for future research.

Clinical Trials in Head and Neck Oncology: an Evaluation of Clinicians' Willingness to Participate

Head & Neck. Mar, 2006  |  Pubmed ID: 16265653

This study investigated the individual and collective ("community") equipoise of surgeons and oncologists and their willingness to take part in each of six hypothetical randomized controlled trials in head and neck oncology.

Laparoscopic Management of Rectal Endometriosis

Diseases of the Colon and Rectum. Feb, 2006  |  Pubmed ID: 16322961

Surgical treatment of females with rectal endometriosis is challenging. The aim of this study was to review the results of laparoscopic intervention in the management of females with this complex disorder.

Multiplex Detection of Surface Molecules on Colorectal Cancers

Proteomics. Mar, 2006  |  Pubmed ID: 16485257

A technique of fluorescence multiplexing is described for analysis of the plasma membrane proteome of colorectal cancer cells from surgically resected specimens, enabling detection and immunophenotyping when the cancer cells are in the minority. A single-cell suspension was prepared from a colorectal tumour, and the mixed population of cells was captured on a CD antibody microarray. The cancer cells were detected using a fluorescently tagged antibody for carcinoembryonic antigen (CEA-Alexa647) or epithelial cell adhesion marker (EpCAM-Alexa488). Using this multiplexing procedure, dot patterns from colorectal cancers were distinct from those of adjacent normal tissue. Subtraction of the expression levels for each antigen from normal tissue from those for the cancer shows differential expression in the cancer of CD66c, CD15s, CD55, CD45, CD71, CD45RO, CD11b and CEA, in descending order. Cells captured on the same microarray were also labelled with fluorescent CD3-phycoerythrin antibody revealing the presence of tumour-infiltrating lymphocytes. The immunophenotypes of T lymphocytes from the tumour samples showed differential expression of HLA-DR, TCR alpha/beta, CD49d, CD52, CD49e, CD5, CD95, CD28, CD38 and CD71, in descending order. Fluorescence multiplexing of mixed cell populations captured on a single antibody microarray enables expression profiling of multiple sub-populations of cells within a tumour sample.

The Role of Telomeres and Telomerase in the Pathology of Human Cancer and Aging

Pathology. Apr, 2006  |  Pubmed ID: 16581649

Cellular senescence, the state of permanent growth arrest, is the inevitable fate of replicating normal somatic cells. Postulated to underlie this finite replicative span is the physiology of telomeres, which constitute the ends of chromosomes. The repetitive sequences of these DNA-protein complexes progressively shorten with each mitosis. When the critical length is bridged, telomeres trigger DNA repair and cell cycle checkpoint mechanisms that result in chromosomal fusions, cell cycle arrest, senescence and/or apoptosis. Should senescence be bypassed at such time, continued cell divisions in the face of dysfunctional telomeres and activated DNA repair machinery can result in the genomic instability favourable for oncogenesis. The longevity and malignant progression of the thus transformed cell requires coincident telomerase expression or other means to negate the constitutional telomeric loss. Practically then, telomeres and telomerase may represent plausible prognostic and screening cancer markers. Furthermore, if the argument is extended, with assumptions that telomeric attrition is indeed the basis of cellular senescence and that accumulation of the latter equates to aging at the organismal level, then telomeres may well explain the increased incidence of cancer with human aging.

Stacking Fault Structure in Shear-induced Colloidal Crystallization

The Journal of Chemical Physics. Apr, 2006  |  Pubmed ID: 16613475

We report measurements of the spatial distribution of stacking faults in colloidal crystals formed by means of an oscillatory shear field at a particle volume fraction of 52% in a system where the pair potential interactions are mildly repulsive. Stacking faults are directly visualized via confocal laser scanning microscopy. Consistent with previous scattering studies, shear orders the initially amorphous colloids into close-packed planes parallel to the shearing surface. Upon increasing the strain amplitude, the close-packed direction of the (111) crystal plane shifts from an orientation parallel to the vorticity direction to parallel the flow direction. The quality of the layer ordering, as characterized by the mean stacking parameter, decreases with strain amplitude. In addition, we directly observe the three-dimensional structure of stacking faults in sheared crystals. We observe and quantify spatial heterogeneity in the stacking fault arrangement in both the flow-vorticity plane and the gradient direction, particularly at high strain amplitudes (gamma> or =3). At these conditions, layer ordering persists in the flow-vorticity plane only over scales of approximately 5-10 particle diameters. This heterogeneity is one component of the random layer ordering deduced from previous scattering studies. In addition, in the gradient direction, the stacking registry shows that crystals with intermediate global mean stacking probability are comprised of short sequences of face-centered cubic and hexagonal close-packed layers with a stacking that includes a component that is nonrandom and alternating in character.

A Systematic Review of Reasons for Nonentry of Eligible Patients into Surgical Randomized Controlled Trials

Surgery. Apr, 2006  |  Pubmed ID: 16627056

The low recruitment rates into surgical randomized controlled trials (RCTs) threaten the validity of their findings. We reviewed the reasons for nonentry of eligible patients into surgical RCTs that would form the basis for future prospective research.

Gelation and Internal Dynamics of Colloidal Rod Aggregates

Journal of Colloid and Interface Science. Aug, 2006  |  Pubmed ID: 16631779

The internal dynamics of fractal cluster gels of colloidal boehmite rods with aspect ratios r = 3.9, 8.6, and 30.1, and colloidal polystyrene spheres (r = 1) are reported. Increasing r decreases the minimum colloid volume fraction for gelation. The behavior of the dynamic structure factor of rod gels is consistent with the internal dynamics of a constrained Brownian fractal object. Colloidal boehmite gels display an abrupt transition from floppy to brittle dynamics at phi approximately 10(-4). Moreover, the fractal cluster size of rod gels is not the determinant of the relaxation time of density fluctuations as it is in spherical particle gels. Instead, the relative behavior of the magnitude and time scale of the constrained fluctuations suggests that the fractal rod network is viscously coupled only on local, rather than cluster, scales. We hypothesize that noncentral forces between the anisometric particles are responsible for this anomalous behavior.

Consumer Choice and the National Bowel Cancer Screening Program

The Medical Journal of Australia. Jun, 2006  |  Pubmed ID: 16768656

The opportunity for informed choice in screening is limited.

Publication Bias in Papers Presented to the Australian Orthopaedic Association Annual Scientific Meeting

ANZ Journal of Surgery. Jun, 2006  |  Pubmed ID: 16768761

The selective publication of articles based on factors, such as positive outcome, statistical significance and study size is known as publication bias. If publication bias is present, any clinical decision based on a review of the published work will also be biased. Publication bias has been shown in various specialties, based on review of publication rates for abstracts presented at major scientific meetings. This study was conducted to investigate publication bias in orthopaedics.

How Does an Historic Control Study of a Surgical Procedure Compare with the "gold Standard"?

Diseases of the Colon and Rectum. Aug, 2006  |  Pubmed ID: 16841269

It has been suggested that nonrandomized studies of interventions can neither discriminate between the effect of an intervention and that of bias nor accurately estimate the magnitude of measured effects. This study was designed to compare the results of an historic control study of a surgical procedure with those of a subsequent randomized control trial conducted under similar circumstances.

Non-entry of Eligible Patients into the Australasian Laparoscopic Colon Cancer Study

ANZ Journal of Surgery. Sep, 2006  |  Pubmed ID: 16922907

There is currently a need to assess the reasons for non-entry of eligible patients into surgical randomized controlled trials to determine measures to improve the low recruitment rates in such trials.

Universal Scaling for Polymer Chain Scission in Turbulence

Proceedings of the National Academy of Sciences of the United States of America. Nov, 2006  |  Pubmed ID: 17075043

We report that previous polymer chain scission experiments in strong flows, long analyzed according to accepted laminar flow scission theories, were in fact affected by turbulence. We reconcile existing anomalies between theory and experiment with the hypothesis that the local stress at the Kolmogorov scale generates the molecular tension leading to polymer covalent bond breakage. The hypothesis yields a universal scaling for polymer scission in turbulent flows. This surprising reassessment of over 40 years of experimental data simplifies the theoretical picture of polymer dynamics leading to scission and allows control of scission in commercial polymers and genomic DNA.

Structure and Dynamics of Colloidal Depletion Gels: Coincidence of Transitions and Heterogeneity

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Oct, 2006  |  Pubmed ID: 17155053

Transitions in structural heterogeneity of colloidal depletion gels formed through short-range attractive interactions are correlated with their dynamical arrest. The system is a density and refractive index matched suspension of 0.20 volume fraction poly(methyl methacyrlate) colloids with the nonadsorbing depletant polystyrene added at a size ratio of depletant to colloid of 0.043. As the strength of the short-range attractive interaction is increased, clusters become increasingly structurally heterogeneous, as characterized by number-density fluctuations, and dynamically immobilized, as characterized by the single-particle mean-squared displacement. The number of free colloids in the suspension also progressively declines. As an immobile cluster to gel transition is traversed, structural heterogeneity abruptly decreases. Simultaneously, the mean single-particle dynamics saturates at a localization length on the order of the short-range attractive potential range. Both immobile cluster and gel regimes show dynamical heterogeneity. Non-Gaussian distributions of single particle displacements reveal enhanced populations of dynamical trajectories localized on two different length scales. Similar dependencies of number density fluctuations, free particle number, and dynamical length scales on the order of the range of short-range attraction suggests a collective structural origin of dynamic heterogeneity in colloidal gels.

Review: Computed Tomographic Colonography is Accurate for Medium and Large Colorectal Polyps and Cancer

Evidence-based Medicine. Oct, 2006  |  Pubmed ID: 17213155

Concordance with National Guidelines for Colorectal Cancer Care in New South Wales: a Population-based Patterns of Care Study

The Medical Journal of Australia. Mar, 2007  |  Pubmed ID: 17371209

To investigate predictors of evidence-based surgical care in a population-based sample of patients with newly diagnosed colorectal cancer.

Patient Preferences Between Surgical and Medical Treatment in Crohn's Disease

Diseases of the Colon and Rectum. May, 2007  |  Pubmed ID: 17380368

Crohn's disease poses difficult choices in which the most appropriate treatment option is not always obvious. When this state of uncertainty exists, patients' preferences should have an increasingly important part of clinical decision making. The purpose of this study was to compare patients' preferences for surgical intervention in Crohn's disease with the preferences of surgeons and gastroenterologists.

Biofeedback for Fecal Incontinence: Short-term Outcomes of 513 Consecutive Patients and Predictors of Successful Treatment

Diseases of the Colon and Rectum. Apr, 2007  |  Pubmed ID: 17476558

Biofeedback is well established as a treatment for fecal incontinence but little is known about factors that may be associated with its effectiveness. This study assessed short-term outcomes, predictors of patients who completed treatment, and predictors of treatment success.

Translational and Rotational Dynamics of Colloidal Rods by Direct Visualization with Confocal Microscopy

Journal of Colloid and Interface Science. Oct, 2007  |  Pubmed ID: 17560590

We report an experimental method to characterize the dynamics of colloidal rods by measuring their rotation and translation in three dimensions with confocal microscopy. The method relies on solvent viscosification to retard dynamics to time scales that are compatible with 3D confocal optical microscopy. Because the method yields a full three-dimensional characterization of rod displacement and orientation, it is applicable to situations in which complex, anisotropic dynamics emerge. Examples include behavior in liquid crystal phases with both orientational and positional order, suspensions subjected to applied fields such as shear flow or sedimentation, and the emerging area of anisotropic particle dynamics. We demonstrate the performance of the method by quantifying the Brownian motion of fluorescent poly(methyl methacrylate) rods (aspect ratio, L/D=3.1 and 7.0) grafted with poly(dimethylsiloxane) stabilizer. The rods are dispersed at dilute concentration in a solvent mixture of viscosity 2.0 Pa s. Rod translational and rotational diffusivities are extracted from the measured translational mean square displacement of the centroid positions and of the rod unit vector u(t), respectively. Rod orientational dynamics are characterized relative to both their azimuthal and polar angles. Probability distributions for the translation and rotation in the frame of rod are computed from the measurements. Experimental values obtained agree well with theory available for the dynamics of isolated rods.

Factors Associated with Back Pain After Physical Injury: a Survey of Consecutive Major Trauma Patients

Spine. Jun, 2007  |  Pubmed ID: 17572628

Cross-sectional survey.

Meta-analysis of Non-randomized Comparative Studies of the Short-term Outcomes of Laparoscopic Resection for Colorectal Cancer

ANZ Journal of Surgery. Jul, 2007  |  Pubmed ID: 17610681

Laparoscopic resection remains to be established as the procedure of first choice for operable colorectal cancer. The aim of the study was to conduct a systematic review of non-randomized comparative studies of laparoscopic resection for colorectal cancer. Published work in English was searched for relevant articles published by the end of 2003. The MOOSE statement was used to conduct the meta-analysis. Study quality was assessed by two investigators using the MINORS tool and the analysis was conducted using Comprehensive Meta-analysis software (Biostat, Englewood, NJ, USA) and Microsoft Excel (Microsoft, Redmond, WA, USA). One thousand two hundred and twenty abstracts were reviewed and 398 articles examined in detail. Out of 108 articles reporting the results of relevant studies, 75 were reports of 64 non-randomized comparative studies. Fifteen studies were excluded. Analysis of the outcomes of 6438 resections showed that the conversion rate was 13.3% with a statistically significant difference between studies with more than 50 versus those with 50 or less attempted resections (11.7 vs 16.5%; P<0.001). Laparoscopic resection took 27.6% (41 min) longer to carry out than open resection. There was no significant difference between the two groups in early mortality rates (1.2 vs 1.1%; P=0.787) or likelihood of re-operation (2.3 vs 1.5%; P=0.319). Laparoscopic resection was associated with a lower morbidity rate (24.05 vs 30.80%, odds ratio (95% confidence interval)=0.77 (0.63-0.95); P=0.014, n=4111, random-effects model). Time until passage of first flatus, passage of a bowel motion, tolerating oral fluids and a solid diet was 1.2-1.6 days (26 to 37%) shorter, measurements of pain and narcotic analgesic requirements were 16-35% lower and hospital stay was 3.5 days (18.8%) shorter following laparoscopic resection compared with open resection. The two approaches were 99% similar in terms of adequacy of oncological clearance. Meta-analysis of non-randomized comparative studies favours laparoscopic over open resection for colorectal cancer. The results were remarkably similar to those of a contemporaneous meta-analysis of randomized controlled trials published by the end of 2002.

Surgical and Oncology Trials for Rectal Cancer: Who Will Participate?

Surgery. Jul, 2007  |  Pubmed ID: 17630005

The assessment of patients' and clinicians' willingness to participate in clinical trials is advisable as part of a feasibility exercise prior to the commencement of randomized controlled trials (RCTs) to ensure adequate support in terms of likely accrual to achieve the required sample size in a timely fashion. Furthermore, understanding why patients are unwilling to enter RCTs is imperative before the current trend of low participation can be reversed.

Anisotropy of Building Blocks and Their Assembly into Complex Structures

Nature Materials. Aug, 2007  |  Pubmed ID: 17667968

A revolution in novel nanoparticles and colloidal building blocks has been enabled by recent breakthroughs in particle synthesis. These new particles are poised to become the 'atoms' and 'molecules' of tomorrow's materials if they can be successfully assembled into useful structures. Here, we discuss the recent progress made in the synthesis of nanocrystals and colloidal particles and draw analogies between these new particulate building blocks and better-studied molecules and supramolecular objects. We argue for a conceptual framework for these new building blocks based on anisotropy attributes and discuss the prognosis for future progress in exploiting anisotropy for materials design and assembly.

Including the Questionnaire with an Invitation Letter Did Not Improve a Telephone Survey's Response Rate

Journal of Clinical Epidemiology. Dec, 2007  |  Pubmed ID: 17998087

To determine whether including the study questionnaire with a letter of invitation improves the response rate in a telephone-based survey.

What is the Value of Computered Tomography Colonography in Patients Screening Positive for Fecal Occult Blood? A Systematic Review and Economic Evaluation

Clinical Gastroenterology and Hepatology : the Official Clinical Practice Journal of the American Gastroenterological Association. Dec, 2007  |  Pubmed ID: 18054752

Computerized tomography colonography (CTC) is a highly accurate test for the detection of colorectal polyps and cancers and has been proposed as a potential alternative to colonoscopy. Bowel cancer screening using fecal occult blood testing (FOBT) and follow-up diagnostic colonoscopy is an effective intervention that currently is being implemented in screening programs internationally. Because of high false-positive rates for FOBT, concerns have been raised about patient uptake and access to colonoscopy services. This study assessed the value of CTC as an alternative to colonoscopy in FOBT-positive individuals.

Programmable Fluidic Production of Microparticles with Configurable Anisotropy

Journal of the American Chemical Society. Jan, 2008  |  Pubmed ID: 18166053

We report a technique for continuous production of microparticles of variable size with new forms of anisotropy including alternating bond angles, configurable patchiness, and uniform roughness. The sequence and shape of the anisotropic particles are configured by exploiting a combination of confinement effects and microfluidics to pack precursor colloids with different properties into a narrow, terminal channel. The width and length of the channel relative to the particle size fully specify the configuration of the anisotropic particle that will be produced. The precursor spheres packed in the production zone are then permanently bonded into particles by thermal fusing. The flow in the production zone is reversed to release the particles for collection and use. Particles produced have linear chain structure with precisely configured, repeatable bond angles. With software programmable microfluidics, sequence and shape anisotropy are combined to yield synthesized homogeneous (type "A"), surfactantlike (type "A-B") or triblock (type "A-B-A") internal sequences in a single device. By controlling the dimensions of the microfluidic production zone, triangular prisms and particles with controlled roughness and patchiness are produced. The fabrication method is performed with precursors spheres with diameter as small as 3.0 microm.

Extended Radical Resection: the Choice for Locally Recurrent Rectal Cancer

Diseases of the Colon and Rectum. Mar, 2008  |  Pubmed ID: 18204879

Surgery for recurrent rectal cancer is the only therapy with curative potential. This study was designed to assess factors that affect survival after surgery for locally recurrent rectal cancer.

Fluidic Assembly and Packing of Microspheres in Confined Channels

Langmuir : the ACS Journal of Surfaces and Colloids. Apr, 2008  |  Pubmed ID: 18294020

We study fluidic assembly and packing of spherical particles in rectilinear microchannels that are terminated by a flow constriction. First, we introduce a method for active assembly of particles in the confined microchannels by triggering a local constriction in the fluid channel using a partially closed membrane valve. This microfluidic valve allows active, on-demand particle assembly as opposed to previous passive assembly methods based on terminal channels and weirs. Second, we study the three-dimensional assembly and packing of particles against a weir in confined rectilinear microchannels. The packings result in achiral particle chains with alternating (zigzag) structure. This structure is characterized by a single, repeated bond angle whose components projected into the frame of the channel are quantified by confocal microscopy and image processing. Brownian dynamics simulation of the packing comprehensively delineates the range of bond angles possible in narrow, rectilinear microchannels as well as the complex dependence of these angles on the relative dimensions of the channel and particles. The simulations of the three-dimensional packings are accurately modeled by a compact theory based on trigonometric relationships. The experimentally measured bond angles show excellent agreement with the simulations, thereby validating the functional dependence of the achiral packing bond angles on channel dimensions. This functional relationship is immediately useful for the design of anisotropic particles by microfluidic synthesis.

The Effect of Compensation on General Health in Patients Sustaining Fractures in Motor Vehicle Trauma

Journal of Orthopaedic Trauma. Apr, 2008  |  Pubmed ID: 18404028

The receipt or pursuit of compensation after injury has been associated with poor outcomes. This study aims to determine the association between compensation-related factors and general health in patients with fractures sustained in motor vehicle trauma.

Predictors of General Health After Major Trauma

The Journal of Trauma. Apr, 2008  |  Pubmed ID: 18404063

Traumatic injury is a leading contributor to the global burden of disease, yet there has been little research on possible predictors of general health after major trauma. This study aims to explore possible predictors of general health after major physical trauma.

Patient and Physician Preferences for Surgical and Adjuvant Treatment Options for Rectal Cancer

Archives of Surgery (Chicago, Ill. : 1960). Apr, 2008  |  Pubmed ID: 18427027

Patients and their clinicians hold varying preferences for surgical and adjuvant treatment therapies for rectal cancer.

Measuring Patient Preference and Surgeon Choice

Surgery. May, 2008  |  Pubmed ID: 18436005

One of the major barriers to randomized trials in the field of surgery is the presence of strong preferences for one of the treatment options. Patients and surgeons who favor strongly a particular treatment approach are usually reluctant to participate in trials where operative intervention is determined on the basis of randomization. This then affects both the feasibility of the trial in terms of achieving the required sample size as well as the generalizability of the study's findings. Therefore, measurement of patient and surgeon preference is a crucial component of the feasibility assessment for surgery trials. In this article, we introduce the Prospective Measure of Preference, which is a novel method to measure preferences that has been designed to accommodate the complexity of surgical decision-making. We also present a simple method to measure individual and community equipoise among expert clinicians to assess the feasibility of future randomized trials in surgery.

Lottery Incentives Did Not Improve Response Rate to a Mailed Survey: a Randomized Controlled Trial

Journal of Clinical Epidemiology. Jun, 2008  |  Pubmed ID: 18471665

Our study aimed to examine the effect of an instant lottery ticket incentive on the response rate to a mailed questionnaire in a population of trauma patients.

Predictors of Post-traumatic Stress Disorder Following Major Trauma

ANZ Journal of Surgery. Jul, 2008  |  Pubmed ID: 18593415

Post-traumatic stress disorder (PTSD) is a common sequel to physical trauma, but there is disagreement regarding the predictors of this condition. This study aims to examine the role of physical, psychosocial and compensation-related factors in the development of PTSD following major trauma.

Structural Origins of Dynamical Heterogeneity in Colloidal Gels

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. May, 2008  |  Pubmed ID: 18643012

We show by resolving single-particle dynamics as a function of contact number that dynamical heterogeneity in depletion colloidal gels must have more than one structural origin. Although the magnitude of dynamical heterogeneity of weak gels with cluster structure and strong gels with string structure is similar, the dependence of particle localization on contact number differs significantly in each. The observed transition between contact number dependent and independent dynamics for the weak and strong gels is abrupt. The results suggest that spatially heterogeneous dynamics cannot be a complete explanation of the dynamical heterogeneity of colloidal gels.

Long-term Functional Outcomes After Laparoscopic and Open Rectopexy for the Treatment of Rectal Prolapse

Diseases of the Colon and Rectum. Nov, 2008  |  Pubmed ID: 18758861

Laparoscopic rectopexy to treat full-thickness rectal prolapse has proven short-term benefits, but there is little long-term follow-up and functional outcome data available.

Local Stress Control of Spatiotemporal Ordering of Colloidal Crystals in Complex Flows

Physical Review Letters. Jul, 2008  |  Pubmed ID: 18764301

We show that spin coating, an unsteady, nonuniform shear flow, produces spatiotemporal variation in the crystal order of concentrated colloidal dispersions that is a universal function of the local reduced critical stress and the macroscopic strain. The dependence of the crystal quality of model poly(methyl methacrylate) colloids on radial and axial position, spin speed, and particle size is quantified by confocal microscopy. The coupling of flow-induced crystallization with the centrifugally driven spin coating flow determines local crystal quality without a priori knowledge of the suspension rheology.

Short-term Outcomes of the Australasian Randomized Clinical Study Comparing Laparoscopic and Conventional Open Surgical Treatments for Colon Cancer: the ALCCaS Trial

Annals of Surgery. Nov, 2008  |  Pubmed ID: 18948799

Laparoscopy has revolutionized many abdominal surgical procedures. Laparoscopic colectomy has become increasingly popular. The short- and long-term benefits and satisfactory surgical oncological treatment of colorectal cancer by laparoscopic-assisted resection remain topical. The long-term outcomes of all international randomized controlled trials are still awaited, and short-term outcomes are important in the interim.

The Australasian Laparaoscopic Colon Cancer Study

ANZ Journal of Surgery. Oct, 2008  |  Pubmed ID: 18959629

Australian and New Zealand Study Comparing Laparoscopic and Open Surgeries for Colon Cancer in Adults: Organization and Conduct

ANZ Journal of Surgery. Oct, 2008  |  Pubmed ID: 18959634

This article describes the initiation and implementation of the multicentre Australia and New Zealand prospective randomized controlled clinical study comparing laparoscopic and conventional open surgical treatments of right-sided and left-sided potentially curable colon cancer (Australasian Laparoscopic Colon Cancer Study). Six hundred and one adult patients were admitted with a clinical diagnosis of a single adenocarcinoma based on a physical examination and colonoscopy, barium enema or computed tomography scan and randomly allocated to either laparoscopic or open surgery. The primary aim of the study is to compare 5-year mortality and tumour recurrence rates between the two groups. Secondary aims include comparisons of safety (intraoperative and early postoperative complications, wound site recurrence, postoperative recovery and 30-day mortality), quality of life, in-hospital costs and short-term mortality and tumour recurrence. The data for 592 patients have been collected. There are currently 3141 person years of follow up. In all 370 patients have been assessed at 5 years. This study shows that large cooperative Australia-New Zealand surgical trials can and should be carried out to address significant clinical issues. When possible, coherence with similar, concurrent international trial protocols ensures broader analyses and applicability of results. It is important to recognize that special attention to sustained funding, surgeon credentialing, clinical protocol standardization, data management, publication policy and the protection of study credibility is required from the outset. The Australasian Laparoscopic Colon Cancer Study will achieve its aims with 5-year assessments of all entered patients in March 2010.

Willingness of Pregnant Women and Clinicians to Participate in a Hypothetical Randomised Controlled Trial Comparing Vaginal Delivery and Elective Caesarean Section

The Australian & New Zealand Journal of Obstetrics & Gynaecology. Dec, 2008  |  Pubmed ID: 19133040

Elective caesarean section is controversial in the absence of compelling evidence of the relative benefits and harms compared with vaginal delivery. A randomised trial of the two procedures to compare outcomes for women and babies would provide the best quality scientific evidence to confirm this debate but it is not known whether such a trial would be feasible.

Adsorption and Elution Characteristics of Nucleic Acids on Silica Surfaces and Their Use in Designing a Miniaturized Purification Unit

Analytical Biochemistry. Feb, 2008  |  Pubmed ID: 18022378

We report nucleic acid (NA) adsorption isotherms and elution profiles for silica surfaces and use these to design a miniaturized NA purification unit based on solid-phase extraction with silica beads. The procedure is based on a pressure drop equation for flow through a packed bed and allows estimation of key design parameters such as channel dimensions, liquid flow rates, sample volume, and amount of silica needed. The usefulness of this design procedure is demonstrated by applying it to a column-based NA purification device for influenza detection for a case study of Madin-Darby canine kidney cells infected with influenza A virus.

Viscous Solvent Colloidal System for Direct Visualization of Suspension Structure, Dynamics and Rheology

Journal of Colloid and Interface Science. Feb, 2008  |  Pubmed ID: 18054033

We introduce a model colloid system comprised of particles dispersed in a viscous solvent that can be applied to 3D direct visualization studies of suspension structure, dynamics and rheology. The colloids are poly(methyl methacrylate) (PMMA) spheres sterically stabilized by a copolymer of poly(diphenyl-dimethyl) (DPDM) siloxane that matches the refractive index of PMMA. The monodisperse particles, synthesized with mean diameter varying from 0.7 to 1.1 microm, are stably dispersed in a DPDM siloxane solvent, with viscosity varying from 2.2 to 4.3 Pa s at 20 degrees C. As opposed to other classes of PMMA colloids dispersed in organic solvents, this system displays minimal charge interactions. At room temperature, pair potential interactions (measured by extrapolation of pair correlation functions to infinite dilution) are well modeled by a generalized Lennard-Jones alpha-2alpha potential (alpha=10) with dimensionless interaction energy, epsilon/k(B)T=0.6. We use the DPDM-PMMA colloidal system in conjunction with confocal microscopy studies to measure: (i) the radial distribution function in 3D at dilute concentrations and (ii) the colloid self-diffusivity in 3D at dilute concentrations. Both measurements, neither previously reported in uncharged systems, are facilitated by the slow, viscous dynamics of the system. We also show that the viscosity and particle size of the system are such that the high-volume fraction shear thickening transition can be accessed at shear rates amenable to direct visualization.

How to Critically Appraise an Article

Nature Clinical Practice. Gastroenterology & Hepatology. Feb, 2009  |  Pubmed ID: 19153565

Critical appraisal is a systematic process used to identify the strengths and weaknesses of a research article in order to assess the usefulness and validity of research findings. The most important components of a critical appraisal are an evaluation of the appropriateness of the study design for the research question and a careful assessment of the key methodological features of this design. Other factors that also should be considered include the suitability of the statistical methods used and their subsequent interpretation, potential conflicts of interest and the relevance of the research to one's own practice. This Review presents a 10-step guide to critical appraisal that aims to assist clinicians to identify the most relevant high-quality studies available to guide their clinical practice.

Flexible Microfluidic Device for Mechanical Property Characterization of Soft Viscoelastic Solids Such As Bacterial Biofilms

Langmuir : the ACS Journal of Surfaces and Colloids. Jul, 2009  |  Pubmed ID: 19219968

We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as bacterial biofilms. In the device, stress is imposed on a test specimen by the application of a fixed pressure to a thin, flexible poly(dimethyl siloxane) (PDMS) membrane that is in contact with the specimen. The stress is applied by pressurizing a microfabricated air channel located above the test area. The strain resulting from the applied stress is quantified by measuring the membrane deflection with a confocal laser scanning microscope. The deflection is governed by the viscoelastic properties of the PDMS membrane and of the test specimen. The relative contributions of the membrane and test material to the measured deformation are quantified by comparing a finite element analysis with an independent (control) measurement of the PDMS membrane mechanical properties. The flexible microfluidic rheometer was used to characterize both the steady-state elastic modulus and the transient strain recoil of two soft materials: gellan gums and bacterial biofilms. The measured linear elastic moduli and viscoelastic relaxation times of gellan gum solutions were in good agreement with the results of conventional mechanical rheometry. The linear Young's moduli of biofilms of Staphylococcus epidermidis and Klebsiella pneumoniae, which could not be measured using conventional methods, were found to be 3.2 and 1.1 kPa, respectively, and the relaxation time of the S. epidermidis biofilm was 13.8 s. Additionally, strain hardening was observed in all the biofilms studied. Finally, design parameters and detection limits of the method show that the device is capable of characterizing soft viscoelastic solids with elastic moduli in the range of 102-105 Pa. The flexible microfluidic rheometer addresses the need for mechanical property characterization of soft viscoelastic solids common in fields such as biomaterials, food, and consumer products. It requires only 200 pL of the test specimen.

What Are the Unmet Supportive Care Needs of People with Cancer? A Systematic Review

Supportive Care in Cancer : Official Journal of the Multinational Association of Supportive Care in Cancer. Mar, 2009  |  Pubmed ID: 19319577

GOALS OF WORK: The identification and management of unmet supportive care needs is an essential component of health care for people with cancer. Information about the prevalence of unmet need can inform service planning/redesign. MATERIALS AND METHODS: A systematic review of electronic databases was conducted to determine the prevalence of unmet supportive care needs at difference time points of the cancer experience. RESULTS: Of 94 articles or reports identified, 57 quantified the prevalence of unmet need. Prevalence of unmet need, their trends and predictors were highly variable in all domains at all time points. The most frequently reported unmet needs were those in the activities of daily living domain (1-73%), followed by psychological (12-85%), information (6-93%), psychosocial (1-89%) and physical (7-89%). Needs within the spiritual (14-51%), communication (2-57%) and sexuality (33-63%) domains were least frequently investigated. Unmet needs appear to be highest and most varied during treatment, however a greater number of individuals were likely to express unmet need post-treatment compared to any other time. Tumour-specific unmet needs were difficult to distinguish. Variations in the classification of unmet need, differences in reporting methods and the diverse samples from which patients were drawn inhibit comparisons of studies. CONCLUSION: The diversity of methods used in studies hinders analysis of patterns and predictors of unmet need among people with cancer and precludes generalisation. Well-designed, context-specific, prospective studies, using validated instruments and standard methods of analysis and reporting, are needed to benefit future interventional research to identify how best to address the unmet supportive care needs of people with cancer.

Evidence-based and Clinical Outcome Scores to Facilitate Audit and Feedback for Colorectal Cancer Care

Diseases of the Colon and Rectum. Apr, 2009  |  Pubmed ID: 19404063

To describe a methodology for surgical audit and feedback based on hospital-level indicators of the quality of colorectal cancer care.

Fundamentals of Magnet-actuated Droplet Manipulation on an Open Hydrophobic Surface

Lab on a Chip. Jun, 2009  |  Pubmed ID: 19458864

We systematically investigate droplet movement, coalescence, and splitting on an open hydrophobic surface. These processes are actuated by magnetic beads internalized in an oil-coated aqueous droplet using an external magnet. Results are organized into an 'operating diagram' that describes regions of droplet stable motion, breakage, and release from the magnet. The results are explained theoretically with a simple model that balances magnetic, friction, and capillary-induced drag forces and includes the effects of particle type, droplet size, surrounding oil layer, surface tension, and viscosity. Finally, we discuss the implications of the results for the design of magnet-actuated droplet systems for applications such as nucleic acid purification, immunoassay and drug delivery.

The Effect of Compensation on Health Care Utilisation in a Trauma Cohort

The Medical Journal of Australia. Jun, 2009  |  Pubmed ID: 19485839

To determine whether there is an association between compensation factors and health care utilisation following major trauma.

Pelvic Exenteration with En Bloc Iliac Vessel Resection for Lateral Pelvic Wall Involvement

Diseases of the Colon and Rectum. Jul, 2009  |  Pubmed ID: 19571697

Lateral pelvic recurrence is considered a poor prognostic variable and a relative contraindication to surgery because of the difficulty in achieving clear margins. The aim of this study was to outline our surgical approach to lateral pelvic sidewall involvement and assess the oncologic and long-term outcomes.

Colloidal System to Explore Structural and Dynamical Transitions in Rod Networks, Gels, and Glasses

Langmuir : the ACS Journal of Surfaces and Colloids. Aug, 2009  |  Pubmed ID: 19572513

We introduce a model system consisting of self-assembled polyamide anisotropic colloids suspended in an aqueous surfactant solution for studies of the dynamics of rod networks, gels, and glasses. The colloidal particles are formed by recrystallization of a polyamide from an aqueous surfactant phase at temperatures from 59 to 100 degrees C. The aspect ratio increases monotonically with temperature from T=59 degrees C to T=100 degrees C and rods with an aspect ratio r=8+/-1 to r=306+/-14 form. We show by confocal laser scanning microscopy and dynamic light scattering a structural transition from dilute rod behavior with diffusive dynamics to a homogeneous network structure with increasingly slow dynamics as the volume fraction is increased. Furthermore, increasing the aspect ratio of rods induces a similar structural transition from dilute rod behavior to a network structure, although at a lower volume fraction. Finally, we vary the pair potential between the rods by a polymer-induced depletion interaction and thereby observe an unexpected network-to-bundle transition. The bundles are several rod diameters wide and 1-2 rod lengths long. The rods appear to be ordered nematically within each bundle. The bundling transition leads to an order of magnitude decrease in the storage modulus of the suspensions. The results can be applied to develop strategies for complex fluid stabilization as well as for fundamental studies of rod gelation and vitrification.

Incidence and Etiology of Pelvic Floor Dysfunction and Mode of Delivery: an Overview

Diseases of the Colon and Rectum. Jun, 2009  |  Pubmed ID: 19581867

Elective cesarean section at patient request is becoming common place. Women are requesting the intervention for preservation of the pelvic floor, but there is conflicting evidence to suggest that this mode of delivery has such benefits. The risks vs. benefits of both vaginal delivery and cesarean section need to be well understood before deciding on a surgical delivery. This review outlines the current available evidence of the risks and benefits associated with vaginal delivery and elective cesarean section and the incidence and mechanisms of injury that lead to pelvic floor dysfunction. As in most surgical conditions, a better understanding of causality of pelvic floor dysfunction may help treatment effectiveness.

Preferences for Outcomes of Treatment for Rectal Cancer: Patient and Clinician Utilities and Their Application in an Interactive Computer-based Decision Aid

Diseases of the Colon and Rectum. Dec, 2009  |  Pubmed ID: 19934920

To quantify the importance that patients and clinicians assign to specific quality-of-life outcomes associated with the treatment of rectal cancer and to demonstrate a clinical application of these data in a computer-based multidimension decision aid (Annalisa).

Invited Commentary

Diseases of the Colon and Rectum. Oct, 2009  |  Pubmed ID: 19966606

Predictors of Patient and Surgeon Satisfaction After Orthopaedic Trauma

Injury. Apr, 2009  |  Pubmed ID: 19041968

Patient satisfaction has only recently gained attention as an outcome measure in orthopaedics, where it has been reported for joint replacement surgery. Little has been published regarding predictors of patient satisfaction in orthopaedic trauma. This study aims to explore the predictors of patient satisfaction, and of surgeon satisfaction, after orthopaedic trauma.

Electric-field-induced Yielding of Colloidal Gels in Microfluidic Capillaries

Langmuir : the ACS Journal of Surfaces and Colloids. Jan, 2010  |  Pubmed ID: 20067317

We introduce a method to generate a purely internal rupture of colloidal particle gels by application of an electric field as they are confined in a microfluidic device. Characterization of the local, microstructural effect of yielding made possible by the device avoids the complication of shear banding that often occurs in attempts to generate yielding of colloidal gels. The gels are comprised of spherical sterically stabilized poly(methyl methacrylate) particles suspended in a density and refractive index matched organic solvent mixture. Because the particles are charged, application of an electric field imposes a force on the gel body that results in homogeneous internal rupture and yielding. After cessation of the electric field, the gel network rapidly reforms. The structure of the reformed gel differs significantly from the one present prior to the application of the electric field. The microstructural changes that accompany the yielding transition are quantified by comparing confocal microscopy image volumes acquired before and after rupture. We find that the local structure of the colloidal gel after recovery, as quantified by the contact number distribution, is negligibly affected by the yielding transition; however, the long-range structure of the gel, as quantified by spatial fluctuations in number density, is significantly impacted. The result highlights the effect of the small number of short-range bond-breaking events that induce the observed changes in collective, long-range structure.

Surface Antigen Profiling of Colorectal Cancer Using Antibody Microarrays with Fluorescence Multiplexing

Journal of Immunological Methods. Apr, 2010  |  Pubmed ID: 20156443

A procedure is described for the disaggregation of colorectal cancers (CRC) and normal intestinal mucosal tissues to produce suspensions of viable single cells, which are then captured on customized antibody microarrays recognising 122 different surface antigens (DotScan CRC microarray). Cell binding patterns recorded by optical scanning of microarrays provide a surface profile of antigens on the cells. Sub-populations of cells bound on the microarray can be profiled by fluorescence multiplexing using monoclonal antibodies tagged with Quantum Dots or other fluorescent dyes. Surface profiles are presented for 6 CRC cell lines (T84, LIM1215, SW480, HT29, CaCo and SW620) and surgical samples from 40 CRC patients. Statistical analysis revealed significant differences between profiles for CRC samples and mucosal controls. Hierarchical clustering of CRC data identified several disease clusters that showed some correlation with clinico-pathological stage as determined by conventional histopathological analysis. Fluorescence multiplexing using Phycoerythrin- or Alexa Fluor 647-conjugated antibodies was more effective than multiplexing with antibodies labelled with Quantum Dots. This relatively simple method yields a large amount of information for each patient sample and, with further application, should provide disease signatures and enable the identification of patients with good or poor prognosis.

Materials Science: Reconfigurable Colloids

Nature. Mar, 2010  |  Pubmed ID: 20336124

Selective Arraying of Complex Particle Patterns

Lab on a Chip. May, 2010  |  Pubmed ID: 20390132

Procedures requiring precise and accurate positioning of particles and cells have impacted a broad range of research interests including molecular detection, self-assembly and tissue and cell engineering. These fields would be greatly aided by more advanced, yet straightforward, micro-object positioning methods that are precise, scalable, responsive and flexible. We have developed an arrayed, multilayer surface patterned microfluidic device which uses laminar convective flow to actively position particles into any desired, two-dimensional, predesigned pattern. Objects including 10 microm polystyrene particles and Saccharomycodes ludwigii cells are rapidly (approximately 2 s) loaded onto vacuum-actuated holes, allowing us to both generate anisotropic particles and culture S. ludwigii cells. The device was further modified to individually control two sets of holes, adding control of pattern composition. With rapid, precise and adaptable operation, multilayer microfluidic devices should greatly assist in research where precise object placement and proximity is necessary.

What Are the Current Barriers to Effective Cancer Care Coordination? A Qualitative Study

BMC Health Services Research. 2010  |  Pubmed ID: 20482884

National cancer policies identify the improvement of care coordination as a priority to improve the delivery of health services for people with cancer. Identification of the current barriers to effective cancer care coordination is needed to drive service improvement.

Quality of Life of Survivors After Pelvic Exenteration for Rectal Cancer

Diseases of the Colon and Rectum. Aug, 2010  |  Pubmed ID: 20628274

There is little information about the impact of pelvic exenteration on patients' quality of life. This study aimed to measure quality of life for longer-term disease-free survivors after pelvic exenteration.

Pair Interaction Potentials of Colloids by Extrapolation of Confocal Microscopy Measurements of Collective Suspension Structure

The Journal of Chemical Physics. Oct, 2010  |  Pubmed ID: 21033819

A method for measuring the pair interaction potential between colloidal particles by extrapolation measurement of collective structure to infinite dilution is presented and explored using simulation and experiment. The method is particularly well suited to systems in which the colloid is fluorescent and refractive index matched with the solvent. The method involves characterizing the potential of mean force between colloidal particles in suspension by measurement of the radial distribution function using 3D direct visualization. The potentials of mean force are extrapolated to infinite dilution to yield an estimate of the pair interaction potential, U(r). We use Monte Carlo simulation to test and establish our methodology as well as to explore the effects of polydispersity on the accuracy. We use poly-12-hydroxystearic acid-stabilized poly(methyl methacrylate) particles dispersed in the solvent dioctyl phthalate to test the method and assess its accuracy for three different repulsive systems for which the range has been manipulated by addition of electrolyte.

Boundary-driven Colloidal Crystallization in Simple Shear Flow

Physical Review Letters. Nov, 2010  |  Pubmed ID: 21231427

Using confocal microscopy, we directly observe that simple shear flow induces transient crystallization of colloids by wall-normal propagation of crystallization fronts from each shearing surface. The initial rate of the front propagation was 1.75±0.07 colloidal layers per unit of applied strain. The rate slowed to 0.29±0.04 colloidal layers per unit of applied strain as the two fronts approached each other at the midplane. The retardation of the front propagation is caused by self-concentration of shear strain in the growing bands of the lower-viscosity crystal, an effect that leads to a progressive reduction of the shear rate in the remaining amorphous material. These findings differ significantly from previous hypotheses for flow-induced colloidal crystallization by homogeneous mechanisms.

Meta-analysis of Well-designed Nonrandomized Comparative Studies of Surgical Procedures is As Good As Randomized Controlled Trials

Journal of Clinical Epidemiology. Mar, 2010  |  Pubmed ID: 19716267

To compare the results of meta-analysis of nonrandomized comparative studies (NRCSs) of a surgical procedure with that of randomized controlled trials (RCTs), and to assess the effect of design and conduct issues in NRCSs on measured outcomes.

Toward Assembly of Non-close-packed Colloidal Structures from Anisotropic Pentamer Particles

Macromolecular Rapid Communications. Jan, 2010  |  Pubmed ID: 21590892

Particles combining multiple anisotropy dimensions offer possibilities for self-assembly that have not been extensively explored to date. The scope for assembly of microparticles in which the anisotropy dimensions of internal bond angle and chemical ordering have been varied is investigated. Colloidal assemblies with interesting open (i.e., non-close-packed) structures can be assembled from these building blocks. The structure of the assemblies formed is linked to the building block anisotropy because the steric constraints introduced induce deviations from close packing. Key challenges addressed in pursuit of these structures are parallelization of microfluidic synthesis methods, simulation to efficiently search the available anisotropy space, and methods that characterize the properties of the resulting assemblies. This combined program of synthesis, simulation, assembly, and characterization may be applied to develop design rules that guide efforts to fabricate microparticle building blocks and their assemblies.

Unmet Supportive Care Needs in Colorectal Cancer: Differences by Age

Supportive Care in Cancer : Official Journal of the Multinational Association of Supportive Care in Cancer. Jun, 2011  |  Pubmed ID: 21691847

PURPOSE: Cancer is primarily a disease of ageing, yet the unmet supportive care needs of older cancer patients are not well understood. This study aims to explore how unmet needs differ by age over the 3 months following colorectal cancer surgery. METHODS: Control groups from pilot phases of an ongoing randomised trial completed the Supportive Care Needs Survey-Short Form 34 (SCNS-SF34) at 1 and 3 months following hospital discharge (n = 57). Multiple regression was used to investigate whether age was an independent predictor of unmet needs in each of the five SCNS-SF34 domains. The proportion of patients with unmet needs and the pattern of item responses were compared between patients aged <65 and ≥65 years at both time points. RESULTS: Older age independently predicted significantly lower levels of unmet need than younger age in nearly all SCNS-SF34 domains. However, more than half of all older patients had unmet needs at both time points (56% and 65%), and age differences in unmet needs were less apparent by 3 months. Older patients were less likely than younger patients to report 'satisfied' needs, as older patients were significantly more likely to report items were 'not applicable' at both 1 month (mean difference 29%, p < 0.001) and 3 months (mean difference 23%, p = 0.01). CONCLUSIONS: While older patients reported lower levels of unmet need than younger patients, the high prevalence of unmet needs and age differences in item response patterns indicate that further research is needed to determine whether older patients' needs are being accurately captured.

Measuring Cancer Care Coordination: Development and Validation of a Questionnaire for Patients

BMC Cancer. 2011  |  Pubmed ID: 21756360

Improving the coordination of cancer care is a priority area for service improvement. However, quality improvement initiatives are hindered by the lack of accurate and reliable measures of this aspect of cancer care. This study was conducted to develop a questionnaire to measures patients' experience of cancer care coordination and to assess the psychometric properties of this instrument.

Predictors of Neck Pain After Motor Vehicle Collisions: a Prospective Survey

Journal of Orthopaedic Surgery (Hong Kong). Dec, 2011  |  Pubmed ID: 22184162

To identify possible predictors (psychosocial) of neck pain in patients with acute injuries following motor vehicle trauma.

Contribution of the Klebsiella Pneumoniae Capsule to Bacterial Aggregate and Biofilm Microstructures

Applied and Environmental Microbiology. Mar, 2011  |  Pubmed ID: 21239544

We studied the interaction between capsule production and hydrodynamic growth conditions on the internal and macroscopic structure of biofilms and spontaneously formed aggregates of Klebsiella pneumoniae. Wild-type and capsule-deficient strains were studied as biofilms and under strong and mild hydrodynamic conditions. Internal organization of multicellular structures was determined with a novel image-processing algorithm for feature extraction from high-resolution confocal microscopy. Measures included interbacterial spacing and local angular alignment of individual bacteria. Macroscopic organization was measured via the size distribution of aggregate populations forming under various conditions. Compared with wild-type organisms, unencapsulated mutant organisms formed more organized aggregates with less variability in interbacterial spacing and greater interbacterial angular alignment. Internal aggregate structure was not detectably affected by the severity of hydrodynamic growth conditions. However, hydrodynamic conditions affected both wild-type and mutant aggregate size distributions. Bacteria grown under high-speed shaking conditions (i.e., at Reynolds' numbers beyond the laminar-turbulent transition) formed few multicellular aggregates while clumpy growth was common in bacteria grown under milder conditions. Our results indicate that both capsule and environment contribute to the structure of communities of K. pneumoniae, with capsule exerting influence at an interbacterial length scale and fluid dynamic forces affecting overall particle size.

Older Patients and Adjuvant Therapy for Colorectal Cancer: Surgeon Knowledge, Opinions, and Practice

Diseases of the Colon and Rectum. Mar, 2011  |  Pubmed ID: 21304306

Increasing patient age independently predicts nonreferral and nonreceipt of adjuvant therapy among patients with colorectal cancer.

Ethical Issues with the Disclosure of Surgical Trial Short-term Data

ANZ Journal of Surgery. Mar, 2011  |  Pubmed ID: 21342382

This paper describes the distinctions between major surgical and pharmaceutical trials and questions the application of a common ethical paradigm to guide their conduct and reporting.

Quality of Life in Perianal Crohn's Disease: What Do Patients Consider Important?

Diseases of the Colon and Rectum. May, 2011  |  Pubmed ID: 21471759

Perianal Crohn's disease can affect quality of life across physical, functional, and psychosocial domains. Little is known about how patients prioritize factors affecting their quality of life.

Randomized Pilot Evaluation of the Supportive Care Intervention "CONNECT" for People Following Surgery for Colorectal Cancer

Diseases of the Colon and Rectum. May, 2011  |  Pubmed ID: 21471765

Improvements can be made in the quality of cancer care if supportive care needs are addressed; however, there are few trials of supportive care interventions to guide policy and practice.

Self-reported Depressive Symptoms and Suicidal Feelings in Perianal Crohn's Disease

Colorectal Disease : the Official Journal of the Association of Coloproctology of Great Britain and Ireland. Mar, 2012  |  Pubmed ID: 21689304

Aim  Crohn's disease is a chronic inflammatory condition that has been associated with high rates of mental illness. Perianal lesions are prevalent; however, their specific impact on depression has not been studied. The aim of our study was to investigate the prevalence and associations of self-reported depressive symptoms in the subset of Crohn's patients with perianal disease. Method  Patients with perianal Crohn's disease from one institution were surveyed to elicit the frequency of self-reported depressive symptoms. Patients completed a questionnaire and consented to medical records audit. Results  Of the 130 patients invited, 69 (53%) returned a survey. Depressive symptoms were self-reported at very high rates, with 73% reporting feeling depressed and 13% reporting feeling suicidal at some point. Associations were found between depressive symptoms and duration of disease, prior surgery, past or present stoma, and anal stenosis. Patients who self-reported depressive symptoms had lower overall utilities, and were willing to trade very significant proportions (upwards of 15%) of their life expectancy for disease cure. Conclusion  This study suggests that many patients with perianal Crohn's disease experience significant emotional distress that impairs their overall quality of life. Further controlled studies are required to assess the impact of perianal disease and to address the need to target interventions to meet the mental health needs of this population.