JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Deformability analysis of sickle blood using ektacytometry.
Biorheology
PUBLISHED: 06-06-2014
Show Abstract
Hide Abstract
Sickle cell disease (SCD) is characterized by decreased erythrocyte deformability, microvessel occlusion and severe painful infarctions of different organs. Ektacytometry of SCD red blood cells (RBC) is made difficult by the presence of rigid, poorly-deformable irreversibly sickled cells (ISC) that do not align with the fluid shear field and distort the elliptical diffraction pattern seen with normal RBC. In operation, the computer software fits an outline to the diffraction pattern, then reports an elongation index (EI) at each shear stress based on the length and width of the fitted ellipse: EI=(length-width)/(length+width). Using a commercial ektacytometer (LORCA, Mechatronics Instruments, The Netherlands) we have approached the problem of ellipse fitting in two ways: (1) altering the height of the diffraction image on a computer monitor using an aperture within the camera lens; (2) altering the light intensity level (gray level) used by the software to fit the image to an elliptical shape. Neither of these methods affected deformability results (elongation index-shear stress relations) for normal RBC but did markedly affect results for SCD erythrocytes: (1) decreasing image height by 15% and 30% increased EI at moderate to high stresses; (2) progressively increasing the light level increased EI over a wide range of stresses. Fitting data obtained at different image heights using the Lineweaver-Burke routine yielded percentage ISC results in good agreement with microscopic cell counting. We suggest that these two relatively simple approaches allow minimizing artifacts due to the presence of rigid discs or ISC and also suggest the need for additional studies to evaluate the physiological relevance of deformability data obtained via these methods.
Related JoVE Video
Related JoVE Video
Antihypertensive efficacy of triple combination perindopril/indapamide plus amlodipine in high-risk hypertensives: results of the PIANIST study (Perindopril-Indapamide plus AmlodipiNe in high rISk hyperTensive patients).
Am J Cardiovasc Drugs
PUBLISHED: 03-05-2014
Show Abstract
Hide Abstract
Our objective was to evaluate a triple-drug antihypertensive strategy for blood pressure control in patients with difficult-to-treat hypertension.
Related JoVE Video
A quinazoline-derivative compound with PARP inhibitory effect suppresses hypertension-induced vascular alterations in spontaneously hypertensive rats.
Biochim. Biophys. Acta
PUBLISHED: 02-25-2014
Show Abstract
Hide Abstract
Oxidative stress and neurohumoral factors play important role in the development of hypertension-induced vascular remodeling, likely by disregulating kinase cascades and transcription factors. Oxidative stress activates poly(ADP-ribose)-polymerase (PARP-1), which promotes inflammation and cell death. We assumed that inhibition of PARP-1 reduces the hypertension-induced adverse vascular changes. This hypothesis was tested in spontaneously hypertensive rats (SHR).
Related JoVE Video
Comparison of minor bleeding complications using dabigatran or enoxaparin after cemented total hip arthroplasty.
Arch Orthop Trauma Surg
PUBLISHED: 02-02-2014
Show Abstract
Hide Abstract
Orally administered chemical thromboprophylactic agents for total hip replacement (THR) have become popular in recent years. Certain clinical trials suggest that the efficacy and the risk of major bleeding after administration of direct thrombin inhibitor dabigatran etexilate are equivalent to the clinical trial comparator, subcutaneous low-molecular-weight heparin enoxaparin. Our aim was to compare and evaluate the incidence of minor haemorrhagic and soft-tissue adverse effects of enoxaparin and dabigatran.
Related JoVE Video
Effects of moderate aerobic exercise training on hemorheological and laboratory parameters in ischemic heart disease patients.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
In this study we set out to determine the effects of long-term physical training on hemorheological, laboratory parameters, exercise tolerability, psychological factors in cardiac patients participating in an ambulatory rehabilitation program.
Related JoVE Video
PARP-inhibitor treatment prevents hypertension induced cardiac remodeling by favorable modulation of heat shock proteins, Akt-1/GSK-3? and several PKC isoforms.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Spontaneously hypertensive rat (SHR) is a suitable model for studies of the complications of hypertension. It is known that activation of poly(ADP-ribose) polymerase enzyme (PARP) plays an important role in the development of postinfarction as well as long-term hypertension induced heart failure. In this study, we examined whether PARP-inhibitor (L-2286) treatment could prevent the development of hypertensive cardiopathy in SHRs. 6-week-old SHR animals were treated with L-2286 (SHR-L group) or placebo (SHR-C group) for 24 weeks. Wistar-Kyoto rats were used as aged-matched, normotensive controls (WKY group). Echocardiography was performed, brain-derived natriuretic peptide (BNP) activity and blood pressure were determined at the end of the study. We detected the extent of fibrotic areas. The amount of heat-shock proteins (Hsps) and the phosphorylation state of Akt-1(Ser473), glycogen synthase kinase (GSK)-3?(Ser9), forkhead transcription factor (FKHR)(Ser256), mitogen activated protein kinases (MAPKs), and protein kinase C (PKC) isoenzymes were monitored. The elevated blood pressure in SHRs was not influenced by PARP-inhibitor treatment. Systolic left ventricular function and BNP activity did not differ among the three groups. L-2286 treatment decreased the marked left ventricular (LV) hypertrophy which was developed in SHRs. Interstitial collagen deposition was also decreased by L-2286 treatment. The phosphorylation of extracellular signal-regulated kinase (ERK)1/2(Thr183-Tyr185), Akt-1(Ser473), GSK-3?(Ser9), FKHR(Ser256), and PKC ?(Ser729) and the level of Hsp90 were increased, while the activity of PKC ?/?II(Thr638/641), ?/?(410/403) were mitigated by L-2286 administration. We could detect signs of LV hypertrophy without congestive heart failure in SHR groups. This alteration was prevented by PARP inhibition. Our results suggest that PARP-inhibitor treatment has protective effect already in the early stage of hypertensive myocardial remodeling.
Related JoVE Video
A strongly emitting liquid-crystalline derivative of Y(3)N@C(80): bright and long-lived near-IR luminescence from a charge transfer state.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 06-27-2013
Show Abstract
Hide Abstract
Great balls of fire: C60 and Y3 N@C80 were connected to the same oligo(phenyleneethynylene) unit to investigate their structural and photophysical properties. NMR investigations revealed a fulleroid structure for the Y3 N@C80 derivative, and both dyads gave rise to columnar phases with core-shell cylinders. The black and gray spheres represent the fullerene core units of the Y3 N@C80 derivative, which is an ideal candidate to be involved in energy and electron transfer processes.
Related JoVE Video
Highlights of cardiology in Hungary.
Eur. Heart J.
PUBLISHED: 08-20-2011
Show Abstract
Hide Abstract
The authors discuss cardiology and their Society in this small central European country.
Related JoVE Video
Regulation of kinase cascade activation and heat shock protein expression by poly(ADP-ribose) polymerase inhibition in doxorubicin-induced heart failure.
J. Cardiovasc. Pharmacol.
PUBLISHED: 06-24-2011
Show Abstract
Hide Abstract
Cardiomyopathy is one of the most severe side effects of the chemotherapeutic agent doxorubicin (DOX). The formation of reactive oxygen species plays a critical role in the development of cardiomyopathies, and the pathophysiological cascade activates nuclear enzyme poly(ADP-ribose) polymerase (PARP), and kinase pathways. We characterized the effects of the PARP-inhibitor and kinase-modulator compound L-2286 in DOX-induced cardiac injury models. We studied the effect of the established superoxide dismutase-mimic Tempol and compared the effects of this agent with those of the PARP inhibitor. In the rat H9C2 cardiomyocytes, in which DOX-induced poly(ADP-ribosyl)ation, L-2286 protected them from the DOX-induced injury in a concentration-dependent manner. In the in vivo studies, mice were pretreated (for 1 week) with L-2286 or Tempol before the DOX treatment. Both the agents improved the activation of cytoprotective kinases, Akt, phospho-specific protein kinase C ϵ, ?/? and suppressed the activity of cell death promoting kinases glycogen synthase kinase-3?, JNK, and p38 mitogen-activated protein kinase, but the effect of PARP inhibitor was more pronounced and improved the survival as well. L-2286 activated the phosphorylation of proapoptotic transcription factor FKHR1 and promoted the expression of Hsp72 and Hsp90. These data suggest that the mode of the cytoprotective action of the PARP inhibitor may include the modulation of kinase pathways and heat shock protein expression.
Related JoVE Video
Puma deletion delays cardiac dysfunction in murine heart failure models through attenuation of apoptosis.
Circulation
PUBLISHED: 06-13-2011
Show Abstract
Hide Abstract
Puma (p53-upregulated modulator of apoptosis) is a proapoptotic Bcl-2 family protein that serves as a general sensor in response to pathological apoptotic stimuli. In previous work, we demonstrated that puma ablation protects the heart from reperfusion injury in a Langendorff setting. Consistent with this, downregulation of Puma in isolated cardiac myocytes prevented apoptosis induced by different proapoptotic agents. Here, we extended our research to investigate the role of Puma, a downstream mediator of p53, in the development of heart failure using Puma(-/-) mice.
Related JoVE Video
Calcaneo-stop procedure for paediatric flexible flatfoot.
Arch Orthop Trauma Surg
PUBLISHED: 05-19-2011
Show Abstract
Hide Abstract
Flexible flatfoot is a frequent deformity found in children. The aim of this study is to evaluate the pedographic outcome of the percutaneous arthroereisis with the use of a screw through the sinus tarsi into the talus.
Related JoVE Video
Cardiac arrest in kearns-sayre syndrome.
JIMD Rep
PUBLISHED: 05-17-2011
Show Abstract
Hide Abstract
The prognosis of progressive ophthalmoplegia in patients with large-scale mitochondrial DNA deletions is highly variable and almost unpredictable. The risk to develop cardiac involvement and sudden cardiac death is strikingly high, especially in patients with Kearns-Sayre syndrome (KSS). The most typical cardiac complications of the disease are conduction defects, which usually begin with left anterior fascicular block with or without right bundle branch block (RBBB), progressing sometimes rapidly to complete atrioventricular block. Other cardiac manifestations reported are first or second degree of AV block, QT prolongation, torsades de pointes ventricular tachycardia, and rarely dilated cardiomyopathy. Most frequently syncope, sometimes even sudden cardiac death, is the first clinical sign of the cardiac disease in KSS. Due to these life-threatening cardiac conditions, patients should be carefully monitored for cardiac signs and symptoms and pacemaker implantation should be suggested early to avoid sudden cardiac arrest in KSS.Here, we present two cases of KSS with life-threatening syncope due to complete atrioventricular block. To emphasize the importance of an early pacemaker implantation, we review the literature on cardiac complications in KSS in the last 20 years. In almost all of the reviewed cases, ophthalmoplegia or ptosis was present before the cardiac manifestations. In most of the cases, syncope was the first symptom of the cardiac involvement. There was no correlation between the age of the onset of the disease and the onset of cardiac manifestations.With our current report, we increase awareness for life-threatening cardiac complications in patients with KSS.
Related JoVE Video
Pathological femoral neck fracture caused by an echinococcus cyst of the vastus lateralis--case report.
BMC Infect. Dis.
PUBLISHED: 04-21-2011
Show Abstract
Hide Abstract
Musculoskeletal hydatid cysts are rare, but being locally invasive, can potentially cause significant deformity or pathological fracture.
Related JoVE Video
Thrombosis preventive potential of chicory coffee consumption: a clinical study.
Phytother Res
PUBLISHED: 02-19-2011
Show Abstract
Hide Abstract
The protective effects of plant polyphenol intake on cardiovascular morbidity and mortality are widely acknowledged. Caffeine-free chicory coffee is a rich source of plant phenolics, including caffeic acid, which inhibits in vitro platelet aggregation, and also phenylpyruvate tautomerase enzymatic activity of the proinflammatory cytokine, macrophage migration inhibitory factor (MIF). To assess whether chicory coffee consumption might confer cardiovascular benefits a clinical intervention study was performed with 27 healthy volunteers, who consumed 300?mL chicory coffee every day for 1?week. The dietary intervention produced variable effects on platelet aggregation, depending on the inducer used for the aggregation test. Whole blood and plasma viscosity were both significantly decreased, along with serum MIF levels, after 1?week of chicory coffee consumption. Moreover, significant improvements were seen in red blood cell deformability. No changes in hematocrit, fibrinogen level or red blood cell counts were detected. The full spectrum of these effects is unlikely to be attributable to a single compound present in chicory coffee, nevertheless, the phenolics, including caffeic acid, are expected to play a substantial role. In conclusion, our study offers an encouraging starting-point to delineate the antithrombotic and antiinflammatory effects of phenolic compounds found in chicory coffee.
Related JoVE Video
Biomechanical comparison of three cemented stem removal techniques in revision hip surgery.
Arch Orthop Trauma Surg
PUBLISHED: 01-04-2011
Show Abstract
Hide Abstract
There are various techniques available to remove a cemented femoral component and distal cement in the case of septic or aseptic loosening, periprosthetic or component fracture. The present study describes the mechanical effects of three techniques: the transfemoral approach (TFA), the distal fenestration technique (DF) and the retrograde stem removal technique (RSR). An experiment on cadaveric femora was performed to establish if there are any differences in the resistance to fracture in and between the various groups.
Related JoVE Video
Detection and isolation of cell-derived microparticles are compromised by protein complexes resulting from shared biophysical parameters.
Blood
PUBLISHED: 11-01-2010
Show Abstract
Hide Abstract
Numerous diseases, recently reported to associate with elevated microvesicle/microparticle (MP) counts, have also long been known to be characterized by accelerated immune complex (IC) formation. The goal of this study was to investigate the potential overlap between parameters of protein complexes (eg, ICs or avidin-biotin complexes) and MPs, which might perturb detection and/or isolation of MPs. In this work, after comprehensive characterization of MPs by electron microscopy, atomic force microscopy, dynamic light-scattering analysis, and flow cytometry, for the first time, we drive attention to the fact that protein complexes, especially insoluble ICs, overlap in biophysical properties (size, light scattering, and sedimentation) with MPs. This, in turn, affects MP quantification by flow cytometry and purification by differential centrifugation, especially in diseases in which IC formation is common, including not only autoimmune diseases, but also hematologic disorders, infections, and cancer. These data may necessitate reevaluation of certain published data on patient-derived MPs and contribute to correct the clinical laboratory assessment of the presence and biologic functions of MPs in health and disease.
Related JoVE Video
Peripheral antinociceptive effect of 2-arachidonoyl-glycerol and its interaction with endomorphin-1 in arthritic rat ankle joints.
Clin. Exp. Pharmacol. Physiol.
PUBLISHED: 06-10-2010
Show Abstract
Hide Abstract
1. Both cannabinoid and opioid receptors are localized at the peripheral level, and drugs acting on these receptors may produce antinociception after topical administration; however, the effect of endogenous ligands at these receptors is poorly understood. Our goal was to determine the antinociceptive potency of the endogenous cannabinoid 2-arachidonoyl-glycerol (2-AG), and its interaction with endomorphin-1 (EM1) at joint level in the rat inflammation model. 2. Mechanical hypersensitivity was produced by injection of carrageenan (300 microg/30 microL) into the tibiotarsal joint of the right hind leg. The mechanical threshold was assessed by von Frey filaments. 2-AG (3-200 microg), EM1 (100-300 microg) and their combinations in a fixed-dose ratio (1 : 10) were given into the inflamed joint, and the threshold was determined repeatedly for 105 min after the drug administrations. 3. Both ligands produced dose-dependent anti-hyperalgesia, and the highest doses caused prolonged effects, but they did not influence the degree of oedema and the withdrawal threshold at the non-inflamed side. EM1 had lower potency compared to 2-AG (ED(25): 233 (CI: 198-268) microg and 126 (CI: 88-162) microg, respectively; P < 0.05). The effects of EM1 and 2-AG were prevented by mu-opioid and cannabinoid 1 receptor antagonists, respectively. The ED(25) value for the combination (98 (CI: 80-112) microg) did not differ significantly from the value of 2-AG; however, the largest dose combination produced a significantly higher effect than the ligands by themselves. 4. Our data showed that 2-AG was an effective antinociceptive ligand at joint level, and its combination with EM1 produced long-lasting, effective antinociception.
Related JoVE Video
Successful treatment of late Salmonella infections in total hip replacement - report of two cases.
BMC Infect. Dis.
PUBLISHED: 06-08-2010
Show Abstract
Hide Abstract
Salmonella species can be rarely isolated from periprosthetic joint infections, however when present, are usually part of a severe septic clinical picture.
Related JoVE Video
Clinical importance of aspirin and clopidogrel resistance.
World J Cardiol
PUBLISHED: 04-12-2010
Show Abstract
Hide Abstract
Aspirin and clopidogrel are important components of medical therapy for patients with acute coronary syndromes, for those who received coronary artery stents and in the secondary prevention of ischaemic stroke. Despite their use, a significant number of patients experience recurrent adverse ischaemic events. Interindividual variability of platelet aggregation in response to these antiplatelet agents may be an explanation for some of these recurrent events, and small trials have linked "aspirin and/or clopidogrel resistance", as measured by platelet function tests, to adverse events. We systematically reviewed all available evidence on the prevalence of aspirin/clopidogrel resistance, their possible risk factors and their association with clinical outcomes. We also identified articles showing possible treatments. After analyzing the data on different laboratory methods, we found that aspirin/clopidogrel resistance seems to be associated with poor clinical outcomes and there is currently no standardized or widely accepted definition of clopidogrel resistance. Therefore, we conclude that specific treatment recommendations are not established for patients who exhibit high platelet reactivity during aspirin/clopidogrel therapy or who have poor platelet inhibition by clopidogrel.
Related JoVE Video
Familiar ochronotic arthropathy-caused by a gene mutation traced three hundred years.
Joint Bone Spine
PUBLISHED: 03-19-2010
Show Abstract
Hide Abstract
Authors trace an ochronotic Hungarian family, which moved from Slovakia to Hungary 300 years ago. As the family members lived in a relatively close village community the gene mutation had been survived silently for ages before the clinical symptoms developed. Family tree analysis could detect with the use of allele specific PCR amplification-the p.G161R mutation of the homogentisic acid 1,2-dioxygenase (HGD) gene, which resulted in a specific genotype appearing in the Slovak population. We found a heterozygote member of this family who has children with an alkaptonuria-homozygote and known-heterozygote genotypes so there would be a high risk of alkaptonuria in their offsprings. Therefore genetic counselling is highly recommended to minimize the risk factors.
Related JoVE Video
Synovial fluid ?-endorphin level in avascular necrosis, rheumatoid arthritis, and osteoarthritis of the femoral head and knee. A controlled pilot study.
Clin. Rheumatol.
PUBLISHED: 02-09-2010
Show Abstract
Hide Abstract
The goal of this study is to determine and compare the ?-endorphin levels in the synovial fluid of patients with different joint disorders (avascular necrosis, AVN; osteoarthritis, OA; and rheumatoid arthritis, RA of the hip or knee). Eighty-seven patients were involved in our study with an average age of 62 years. Thirty-three patients had AVN (18 hips, 15 knees). Twenty-three patients were diagnosed with OA (14 hips, 9 knees), and 31 patients suffered from RA (12 hips, 19 knees). We measured the ?-endorphin levels of the synovial fluids -harvested from surgery-with radioimmunoassay. No significant difference was found in the ?-endorphin levels of the synovial fluid from AVN comparing to OA and RA, however ?-endorphin level was significantly higher in RA group than among patients with OA (p?=?0.01). Synovial ?-endorphin level was slightly lower in knee comparing to hip joint p?=?(0.06). When examining the different joints separately in compliance with diagnoses, we concluded that the synovial ?-endorphin level from AVN was between the values of OA and RA without significant difference, whereas it was significantly higher in the knee of RA, than of OA groups (p?=?0.05 knee, p?=?0.2 hip). Our results confirmed those experiments which stated that there is a significant increase in synovial ?-endorphin level in patients with inflammatory autoimmune diseases (e.g., RA), comparing to the level measured in degenerative conditions (e.g., OA).
Related JoVE Video
Retrograde genocephalic removal of fractured or immovable femoral stems in revision hip surgery.
Hip Int
PUBLISHED: 01-22-2010
Show Abstract
Hide Abstract
Revision arthroplasty for femoral stem breakage can be challenging. We report a new method for the removal of the distal stem segment performed in 6 cases between 2004 and 2008. After extracting the proximal part of the femoral component, the femoral canal was opened at the knee joint and a modified intramedullary nail was used to dislodge the distal stem under fluoroscopic control. In five cases the surgery was uneventful. In one case femoral perforation occurred due to the contour of the cement mantle at the tip of the stem. In the postoperative period all patients progessed well. Removal of a broken stem using our method has limited indications, and it is not recommended in septic cases or when the cement mantle at the tip of the stem has an oblique contour. It also requires opening of the knee joint, but the technique is simple, saves surgical time and in selected cases it does not weaken the femur.
Related JoVE Video
Fixation of Akin osteotomy for hallux abductus with absorbable suture.
Arch Orthop Trauma Surg
PUBLISHED: 01-05-2010
Show Abstract
Hide Abstract
The Akin osteotomy is a widely used procedure where various fixation methods are available, predominantly with the use of metallic component (wire, screw, staple etc.). The aim of this study is to demonstrate the results of our modified Akin procedures, where the fixation of the phalangeal osteotomy is achieved by absorbable suture, without metallic component.
Related JoVE Video
Use of octreotide in the treatment of chylopericardium.
Heart Lung
PUBLISHED: 01-04-2010
Show Abstract
Hide Abstract
Chylopericardium involves the pericardial effusion of chyle, which can be a primary (idiopathic) or secondary condition to injury or obstruction of the thoracic duct. We present a case of isolated chylopericardium that appeared after coronary artery bypass grafting in a 46-year-old woman. After failure of the usual conservative therapy for chylopericardium, ie, pericardial drainage and a low-fat, medium-chain triglyceride diet, her treatment was completed with octreotide, a long-acting somatostatin analog. Octreotide was used subcutaneously at a 3 × 100 ?g daily dose for 2 weeks. The production of pericardial fluid decreased gradually, and had normalized by the end of treatment. No side effects were evident during therapy.
Related JoVE Video
Alcohol-free red wine inhibits isoproterenol-induced cardiac remodeling in rats by the regulation of Akt1 and protein kinase C alpha/beta II.
J. Nutr. Biochem.
PUBLISHED: 10-23-2009
Show Abstract
Hide Abstract
There is increasing evidence that moderate consumption of red wine containing high amount of polyphenols and anthocyanins is associated with decreased incidence of cardiovascular morbidity and mortality. Therefore, we hypothesized that cardiac hypertrophy and fibrosis as well as Akt (protein kinase B, PKB) and protein kinase C (PKC) cascades can be beneficially influenced by an alcohol-free red wine (AFRW) extract rich in 14 types of polyphenols and 4 types of anthocyanins during cardiac remodeling. To test this assumption, rats were treated with isoproterenol (ISO) to induce postinfarction remodeling and were given tap water or AFRW ad libitum for 8 weeks. Control rats received vehicle instead of ISO. Heart mass/body mass and ventricle mass/body mass ratios, diameter of cardiomyocytes, phosphorylation of PKC alpha/beta II and protein kinase B/Akt, and deposition of collagen type III were determined from the hearts of all four groups of rats. All measured gravimetric parameters, myocyte diameters and the amount of collagen type III decreased, and the phosphorylation of PKC alpha/beta II was reduced in the ISO+AFRW group compared to the ISO group. AFRW induced activation of Akt, one of the best characterized cytoprotective pathways even without ISO treatment, and this activation was further increased in the ISO+AFRW group. These data suggest that AFRW treatment has a protective effect on hearts undergoing postinfarction remodeling by repressing hypertrophy-associated increased phosphorylation of PKC alpha/beta II and by activating Akt, providing a molecular mechanism for the cardioprotective effect of red wine polyphenols.
Related JoVE Video
Relationships between hemodynamic, hemorheological and metabolic responses during exercise.
Biorheology
PUBLISHED: 05-22-2009
Show Abstract
Hide Abstract
Aerobic performance is dependent on both cardio-respiratory and peripheral factors with hemodynamic parameters playing a major role. However, whether blood rheology might affect aerobic performance through an effect on hemodynamic factors is not known. The aim of the present study was to assess the relationships between hemodynamic, hemorheological and metabolic parameters in response to a sub-maximal cycling exercise protocol consisting of three successive levels of nine min duration (50, 100 and 150 W). Ten young sportsmen participated in the present study. Mean arterial pressure (MAP) was measured manually, with thoracic impedance used to monitor cardiac output (Qc): systemic vascular resistance (SVR) was then calculated. Whole blood viscosity (etab) was measured and used to calculate systemic vascular hindrance. Hematocrit (Hct) was determined by micro-centrifugation and red blood cell (RBC) deformability (EI) was determined by ecktacytometry. A breath-by-breath gas analyzer was used to measure oxygen uptake (VO2); the Fick equation was used to calculate arterio-venous oxygen difference [(a-v)O(2)] from VO(2) and Qc. All measurements were performed at rest, during exercise and during recovery. Compared to baseline, Qc, MAP, Hct, EI, VO(2), and (a-v)O(2) increased during exercise. etab increased above baseline only at 150 W and remained elevated during recovery; the increase in etab during the last level of exercise was associated with a decrease of SVR and systemic vascular hindrance. There was a significant negative correlation between EI and SVR (r=-0.35, p<0.01) and a significant positive relationship between EI and (a-v)O(2) (r=0.35, p<0.01) and between EI and VO(2) (r=0.37, p<0.01) across all exercise workloads, thus suggesting a potential role for RBC deformability as a factor affecting aerobic performance via oxygen delivery to tissues. These data lend support to the concept that hemorheological parameters may contribute to hemodynamic and cardio-respiratory adaptations in response to exercise in moderately trained sportsmen.
Related JoVE Video
PARP inhibition delays transition of hypertensive cardiopathy to heart failure in spontaneously hypertensive rats.
Cardiovasc. Res.
PUBLISHED: 05-14-2009
Show Abstract
Hide Abstract
Oxidative stress followed by abnormal signalling can play a critical role in the development of long-term, high blood pressure-induced cardiac remodelling in heart failure (HF). Since oxidative stress-induced poly(ADP-ribose)polymerase (PARP) activation and cell death have been observed in several experimental models, we investigated the possibility that inhibition of nuclear PARP improves cardiac performance and delays transition from hypertensive cardiopathy to HF in a spontaneously hypertensive rat (SHR) model of HF.
Related JoVE Video
Effect of Sclerovit on endothelial dysfunction, hemorheological parameters, platelet aggregation, plasma concentration of homocysteine and progression of atherosclerosis in patients with vascular diseases.
Clin. Hemorheol. Microcirc.
PUBLISHED: 04-14-2009
Show Abstract
Hide Abstract
In our prospective study the effect of Sclerovit (0.8 mg folic acid, 20 mug vitamin B12,5 mg vitamin B6,100 mg vitamin E) on inflammatory markers, hemorheological parameters, platelet aggregation, von Willebrand factor activity as a marker of endothelium dysfunction, plasma lipids, plasma levels of folic acid, vitamin B12 and homocysteine (hcy), flow mediated vasodilatation (FMD) and thickness of carotis intima-media after 1 and 6 months of treatment in patients with vascular diseases (10 patients took 1 capsule, 10 patients 2 capsules of Sclerovit and 10 patients placebo) was determined.Plasma level of vitamin B12, folic acid and elongation index of red blood cells (RBC) increased significantly (p<0.05-0.001), hcy and triglyceride concentrations decreased significantly (p<0.05-0.001) in patients taking Sclerovit. HDL-cholesterol, RBC count, hematocrit, plasma and whole blood viscosity increased significantly (p<0.05-0.001) both in patients taking placebo or vitamins. Fibrinogen and CRP showed a significant (p<0.05-0.01) increase in patients on placebo, but did not change in patients on Sclerovit therapy. FMD showed a significant (p<0.05) amelioration in patients on 1 capsule of Sclerovit.Beside the favorable effects of Sclerovit on some of the measured parameters, the observed deterioration in hemorheological parameters can correlate with the contradictory results of large prospective studies with vitamins.
Related JoVE Video
Gene expression and activity of cartilage degrading glycosidases in human rheumatoid arthritis and osteoarthritis synovial fibroblasts.
Arthritis Res. Ther.
PUBLISHED: 03-09-2009
Show Abstract
Hide Abstract
Similar to matrix metalloproteinases, glycosidases also play a major role in cartilage degradation. Carbohydrate cleavage products, generated by these latter enzymes, are released from degrading cartilage during arthritis. Some of the cleavage products (such as hyaluronate oligosaccharides) have been shown to bind to Toll-like receptors and provide endogenous danger signals, while others (like N-acetyl glucosamine) are reported to have chondroprotective functions. In the current study for the first time we systematically investigated the expression of glycosidases within the joints.
Related JoVE Video
Effect of parenteral or oral vinpocetine on the hemorheological parameters of patients with chronic cerebrovascular diseases.
Phytomedicine
PUBLISHED: 01-08-2009
Show Abstract
Hide Abstract
Hemorheological factors play an important role in the pathomechanism of ischemic cerebrovascular disorders. Abnormal rheological conditions in patients with chronic cerebrovascular disease predispose for recurrent strokes. Vinpocetine (VP), a synthetic ethyl esther of apovincamine, has successfully been used in the treatment of cerebrovascular diseases, in part because of its favourable rheological effects.
Related JoVE Video
[Vinpocetin in neurological diseases].
Ideggyogy Sz
Show Abstract
Hide Abstract
Stroke is the third leading cause of death worldwide (following cardiovascular and cancer mortality) and associated with serious disability for the vast majority of patients. There is no salvage therapy for irreversibly damaged brain areas, improving the circulation of the surrounding hypoperfused areas may be associated with beneficial clinical effects. Cerebral hypoperfusion may play a role in the pathogenesis of other kind of neurological diseases, improvement of global circulation may have a preventive effect on these conditions.
Related JoVE Video
[The heart as an endocrine organ].
Orv Hetil
Show Abstract
Hide Abstract
The discovery of cardiac hormone production significantly changed the evaluation of the function of the heart, which is rather regarded as a determining factor of the electrolyte and hemodynamic homeostasis cooperating with other organ systems instead of a mechanical pump. The most important hormones produced by the heart are the natriuretic peptides that have the primary role of protection against volume overload through natriuretic, diuretic, vasodilator and antiproliferative effects. They are integrative markers of the cardiac, vascular and renal functions and marking cardiorenal distress. Brain natriuretic peptide and the N-terminal pro-hormone (NT-proBNP) became generally accepted markers of heart failure exceeding traditional pathophysiological significance of those. They are useful in the diagnosis, estimation of prognosis and therapy guidance and their therapeutic administration is also available. Although the detection of extraadrenal aldosterone production is an exciting new discovery, intracardial aldosterone production is not significant in human beings. The intracardial thyroid hormone production is regulated by deiodinase activity. The role of elevated T3 concentration was suggested in the development of cardiac hypertrophy, while low T3 is assumed to be important in adaptation to hypoxia. An unexpected, complex relation can be determined between epicardial adipose tissue and coronary artery diseases, cytokine and adipokine production of adipocytes might be a part of the self-enhancing process of atherosclerosis.
Related JoVE Video
Improved flow cytometric assessment reveals distinct microvesicle (cell-derived microparticle) signatures in joint diseases.
PLoS ONE
Show Abstract
Hide Abstract
Microvesicles (MVs), earlier referred to as microparticles, represent a major type of extracellular vesicles currently considered as novel biomarkers in various clinical settings such as autoimmune disorders. However, the analysis of MVs in body fluids has not been fully standardized yet, and there are numerous pitfalls that hinder the correct assessment of these structures.
Related JoVE Video
The recently identified hexosaminidase D enzyme substantially contributes to the elevated hexosaminidase activity in rheumatoid arthritis.
Immunol. Lett.
Show Abstract
Hide Abstract
Since the 1970s, numerous reports have described elevated hexosaminidase activities in rheumatoid arthritis. However, due to the overlapping substrate specificities of different hexosaminidases, identification of the exact enzyme(s) responsible for the elevated activity remains incomplete. In this work we tested if the recently described enzyme, hexosaminidase D was expressed in human arthritic joints, and could contribute to the elevated hexosaminidase activity in rheumatoid arthritis. Thermostable ?-d-N-acetyl-galactosaminidase (hexosaminidase D) activities were determined in synovial fluid samples, synovial membranes, synovial fibroblast cell strains and synovial fibroblast-derived extracellular vesicles of patients with rheumatoid arthritis and osteoarthritis using chromogenic substrates. Expression of the HEXDC gene was detected both in steady state and in TGF-? treated synovial fibroblasts by real time PCR. Strikingly, hexosaminidase D accounted for approximately 50% of the total ?-N-acetyl-galactosaminidase activity in synovial membranes and synovial fibroblasts, and it was responsible for the vast majority of the ?-d-N-acetyl-galactosaminidase activity in synovial fluid samples. TGF-? downregulated the expression of hexosaminidase D in synovial fibroblasts dose-dependently. Of note, significant activity of hexosaminidase D was also found in association with extracellular vesicles released by synovial fibroblasts. This first study that describes the expression and disease relevance of the HEXDC gene in humans demonstrates the expression of this novel enzyme within the joints, and suggests that its activity may significantly contribute to the overall local exoglycosidase activity.
Related JoVE Video
[Experimental studies of microcirculatory changes in the bone].
Magy Seb
Show Abstract
Hide Abstract
Our aim was to characterize the periosteal microvascular reaction induced by the destruction of endosteal vasculature by reaming, and to monitor the time sequence of the events. We have also compared the microcirculatory effects of different implant materials that are most frequently employed in human endoprosthetics.
Related JoVE Video
Periosteal microvascular reorganization after tibial reaming and intramedullary nailing in rats.
J Orthop Sci
Show Abstract
Hide Abstract
Intramedullary reaming and nailing of long bones impairs the endosteal circulation, often causing necrosis of the inner region of the bone cortex. We hypothesized that compensatory hypertrophy of the periosteal microcirculation may develop in response to mechanical destruction of the endosteum, and that this may affect bone survival in these circumstances. In these studies, nailing was performed with materials that affect regeneration of the endosteum differently, and the effects on the tibial periosteal microvasculatory organization were examined.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.