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Other Publications (45)

Articles by Han Jiang in JoVE

 JoVE Neuroscience

Gene Transfer to the Developing Mouse Inner Ear by In Vivo Electroporation

1Oregon Hearing Research Center, Oregon Health & Science University

JoVE 3653

The mouse inner ear is a placode-derived sensory organ whose developmental program is elaborated during gestation. We define an in utero gene transfer technique consisting of three steps: mouse ventral laparotomy, transuterine microinjection, and in vivo electroporation. We use digital video microscopy to demonstrate the critical experimental embryological techniques.

 JoVE Clinical and Translational Medicine

Cerenkov Luminescence Imaging (CLI) for Cancer Therapy Monitoring

1Department of Radiology and Bio-X Program Canary Cancer at Stanford for Cancer Early Detection, Stanford University

JoVE 4341

Use of Cerenkov Luminescence Imaging (CLI) for monitoring preclinical cancer treatment is described here. This method takes advantage of Cerenkov Radiation (CR) and optical imaging (OI) to visualize radiolabeled probes and thus provides an alternative to PET in preclinical therapeutic monitoring and drug screening.

Other articles by Han Jiang on PubMed

[A Survey on Dental Knowledge and Behavior of Mothers and Teachers of School Children]

The purpose of this survey was to assess dental knowledge and behaviors of the teachers and mothers of school children.

Can School-based Oral Health Education and a Sugar-free Chewing Gum Program Improve Oral Health? Results from a Two-year Study in PR China

The purpose of the study was to assess the outcome of school-based oral health education (OHE) and a sugar-free chewing gum program on the oral health status of children in terms of reduced caries increment and gingival bleeding over a period of 2 years. Nine primary schools randomly chosen from one district were divided into three groups: OHE group (Group E), sugar-free chewing gum in addition to OHE group (Group G), and the control group (Group C). All children of grade 1 (aged 6-7 years) were recruited (n = 1342). After 2 years, 1143 children remained in the study group at follow-up. The overall drop-out rate was about 15%. Data on dental caries and gingival bleeding were collected by clinical examination. The results showed that the mean increment of DMFS in Group G was 42% lower than in groups E and C (P < 0.05). The mean increments in F-S were higher in Groups G and E than in Group C (P < 0.01). The gingival bleeding scores were statistically significant among the three groups. Compared to Group C, the mean increment in bleeding scores of Group G was 71% lower (P < 0.01) and in Group E 42% lower (P < 0.05). The school-based OHE programs had some positive effect improving children's oral hygiene; in certain circumstances children may benefit from using polyol-containing chewing gum in terms of reduced dental caries.

Effect of Professional Application of APF Foam on Caries Reduction in Permanent First Molars in 6-7-year-old Children: 24-month Clinical Trial

The purpose of the study was to evaluate the effect of 6-monthly professional application of APF foam on caries reduction in permanent first molars in 6-7-year-old children over 24 months, and to compare the caries-preventive effect between APF foam and APF gel.

[A New Discovery of Anaerobic Sludge Granular with Big Aera Minerals Core]

A anaerobic sludge granular containing mineral core with a diameter of 1mm was discovered in lab scale expanded granular sludge bed (EGSB) reactor operated only with glucose as substrate. By SEM, the granular was a core packed by compact bacterium, in which minerals distribute equally and there are caves caused by biological self-degradation. By energy spectrum and X-ray, the core is composed of Ca5 (PO4 x CO3)3 (OH). On the basis of its construction characteristics, the developing mechanism was investigated as well as the developing model of the sludge granular was present, the results shown that the contributing factors influencing mineral core formation are external and internal pH value of sludge granular.

Self-assessed Dental Health, Oral Health Practices, and General Health Behaviors in Chinese Urban Adolescents

The objectives of this study were: to describe perceived dental health status and oral health-related knowledge, attitudes, and behavior in Chinese urban adolescents; to assess the associations of oral health variables with socio-economic status and school performance; and to analyse the relative effect of socio-behavioral risk factors on perceived dental health, perceived need for dental care, and experience of dental symptoms. A cross-sectional survey of 2662 adolescents was conducted in eight capital cities in China; the response rate was 92%. The study population was chosen by multistage cluster sampling and covered three age groups: 11, 13, and 15 years. Data on dental and general health were collected by self-administered questionnaires. Self-assessment of dental health of Chinese adolescents was generally good, only 12% of the students answered that their teeth were "poor" or "very poor", and 9% claimed having "poor" or "very poor" gums. Eleven percent of participants said that other students made fun of their teeth; 24% of the respondents were dissatisfied with the appearance of their teeth, and 41% claimed that they had experienced toothache or symptoms during the previous 12 months. Positive attitudes towards dental care were found in all age groups; 67% of adolescents brushed their teeth at least twice a day and 48% of the students used fluoridated toothpaste. Only 26% of the students visited a dentist during the previous 12 months. In all, 6% of the adolescents had tried cigarette smoking at least once, while 41% reported having tasted alcohol drinks. Multivariate regression analyses showed that perceived dental health status and needs were associated with gender, age, unhealthy lifestyles, poor school performance, and socio-economic status. The establishment of school-based health promotion programs in China is urgently needed, and promotion of oral health lifestyles should be integrated with other general health actions.

Anti-gingivitis Effect of a Dentifrice Containing Bioactive Glass (NovaMin) Particulate

The objective of this pilot clinical trial was to evaluate the anti-gingivitis and anti-plaque effects of a dentifrice containing bioactive glass (NovaMin) compared with a placebo control dentifrice in a 6 weeks clinical study.

[A Three-year Evaluation of the Effectiveness of the School-based Oral Health Education Program]

The aim of this study was to evaluate the oral health outcomes of a school-based oral health education (OHE) programme on children, mothers and school teachers.

Promoter-associated RNA is Required for RNA-directed Transcriptional Gene Silencing in Human Cells

siRNAs targeted to gene promoters can direct epigenetic modifications that result in transcriptional gene silencing in human cells. It is not clear whether the antisense strand of the siRNAs bind directly to DNA or to a sense-stranded RNA transcript corresponding to the known promoter region. We present evidence that an RNA polymerase II expressed mRNA containing an extended 5' untranslated region that overlaps the gene promoter is required for RNA-directed epigenetic modifications and transcriptional silencing of the RNA-targeted promoter. These promoter-associated RNAs were detected by their hybridization to the antisense strand of the complementary promoter-directed siRNA. Antisense phosphorothioate oligodeoxynucleotides were used to degrade the promoter-associated RNA transcripts, the loss of which abrogated the effect of siRNA-mediated transcriptional gene silencing, as well as the complexing of the siRNA with the silent state histone methyl mark and the promoter-associated RNA. These data demonstrate that low-copy promoter-associated RNAs transcribed through RNAPII promoters are recognized by the antisense strand of the siRNA and function as a recognition motif to direct epigenetic silencing complexes to the corresponding targeted promoters to mediate transcriptional silencing in human cells.

An RNA Targeted to the HIV-1 LTR Promoter Modulates Indiscriminate Off-target Gene Activation

Transcriptional gene silencing (TGS) can be achieved by small RNAs targeted to upstream promoter regions. Previously we characterized siRNAs targeted to the HIV-1 long terminal repeat (LTR) promoter at site 247, and found that a 21-base antisense strand of siRNA-247 (LTR-247as) suppressed LTR-mediated expression. To characterize the specificity of LTR-247as, vectors expressing antisense RNAs targeted to a region spanning 50 bases up- and downstream of the 247 target site were generated. LTR-247as+7, a approximately 22 base antisense RNA that is shifted by only seven bases upstream of LTR-247as, showed a significant increase in LTR-driven reporter gene expression that was independent of cell type and active chromatin methyl-marks. Promoter-targeting siRNAs have been recently shown to induce gene activation. However, here we demonstrate gene activation via a sequence-specific off-target effect. Microarray analysis of LTR-247as+7-treated cultures resulted in the deregulation of approximately 185 genes. A gene of unknown function, C10orf76, was responsive to inhibition by LTR-247as+7 and the loss of C10orf76 resulted in the upregulation of several genes that were activated by LTR-247as+7. These data suggest caution when using short antisense RNAs or siRNAs designed to target promoter sequences, since promoter-targeted RNAs may have unintended inhibitory effects against factors with suppressive gene activity.

[A Two-year Randomized Clinical Trial of 1.23% Fluoride Foam on Dental Caries Increment in Primary Teeth]

To evaluate the effect of bi-annual professional application of 1.23% fluoride foam on caries reduction in the primary dentition over a two-year period.

Oral and General Health Behaviours Among Chinese Urban Adolescents

The objectives of this study were to measure the association of general and oral health-related behaviours with living conditions and to explore the interrelationships between general and oral health-related behaviours in Chinese urban adolescents.

Radiographic Predictors of Residual Low Back Pain After Laminectomy for Lumbar Canal Stenosis: a Minimum of 6-year Follow-up

To identify radiographic predictors of residual low back pain (LBP) after laminectomy for lumbar canal stenosis (LCS).

Clinical Evaluation of a Dentifrice Containing Calcium Sodium Phosphosilicate (novamin) for the Treatment of Dentin Hypersensitivity

To evaluate the efficacy of a dentifrice containing calcium sodium phosphosilicate (NovaMin) study versus a placebo and a commercially-available SrCl2 containing dentifrice for the treatment of dentin hypersensitivity.

[Inoculation of Murine Bone Marrow Mesenchymal Stem Cells Induces Tumor Necrosis in Mouse with Orthotopic Hepatocellular Carcinoma]

To observe whether murine bone marrow mesenchymal stem cells (MSCs) implantation improves the survival of hepatocellular carcinoma (HCC)-bearing mice,and to investigate whether MSCs can differentiate to hepatocytes in HCC microenvironment in a mouse model of orthotopic HCC and its effects on tumor cells.

Egg Albumin As a Nanoreactor for Growing Single-crystalline Fe3O4 Nanotubes with High Yields

Single-crystalline Fe(3)O(4) nanotubes have been synthesized successfully by using egg albumin as a nanoreactor; these three-dimensional material nanotubes are formed through a rolling mechanism under mild biological conditions.

[The Correlation Between Interleukin-1 Receptor Antagonist Genotype and Coronary Heart Disease in Patients with Chronic Periodontitis]

To investigate the correlation between interleukin-1 receptor antagonist (IL-1ra) genotype and chronic periodontitis in patients with coronary heart disease.

Root Caries Patterns and Risk Factors of Middle-aged and Elderly People in China

The objectives of this study were to describe root caries patterns of Chinese adults and to analyze the effect of selected demographic and socioeconomic factors on these patterns. A total sample of 1080 residents aged 35-44-years-old and 1080 residents aged 65-74-years-old from three urban and three rural survey sites in Hubei Province participated in both an oral health interview and a clinical oral health examination. Root surface caries prevalence rates were 13.1% in the middle-aged group and 43.9% in the elderly group. The mean number of teeth affected by caries in the middle-aged group was reported at 0.21 and 1.0 in the elderly group. Mean Root Caries Index (RCI) scores of the middle-aged were reported at 6.29 and elderly subjects were reported at 11.95. Elderly people living in rural areas reported a higher RCI score (13.24) than those living in urban areas (10.70). A significantly higher frequency of root surface caries was observed in elderly participants (P < 0.001, OR = 3.80) and ethnic minorities (P < 0.001, OR = 1.93). In addition, smokers, nontea drinkers, and those with an annual household income of 10,000 yuan or less tended to have higher caries prevalence. RCI figures for the different tooth types ranged from 1% to 16%, indicating a wide variation in attack rates. In conclusion, our study suggests that root surface caries occurrence is high among the Chinese adult population, especially older adults. With an increasing number of retained teeth in both middle-aged and elderly people, root caries is a growing disease in the People's Republic of China which deserves more attention in future research.

Assessing the Effectiveness of a School-based Oral Health Promotion Programme in Yichang City, China

To assess the outcome of oral health promotion in schoolchildren over a 3-year period in Yichang City, Hubei, China.

Effects of Colchicine or Demecolcine on Cytoplasmic Protrusions and Assisted Enucleation of Golden Hamster Oocytes

To establish experimental protocols for cloning golden hamsters, optimal concentrations of colchicine and demecolcine were determined for inducing cytoplasmic protrusion (containing chromosomes) and assisting enucleation of their oocytes. Denuded oocytes at different ages were treated with 2.5-10 microg/ml of colchicine for 1-4h or 0.02-0.6 microg/ml of demecolcine for 15-60 min. Cytoplasmic protrusions of oocytes were removed with a micromanipulation pipette. The results show that: 1) at 13.5-18h post-hCG injection, approximately 90% of oocytes treated for with 10 microg/ml of colchicine formed cytoplasmic protrusions, and in some oocytes enucleation occurred; 2) when treated with 0.4 microg/ml of demecolcine for 1h, cytoplasmic protrusions 13.5-18h post-hCG treatment were present in almost all oocytes; 3) after the protrusions induced by either treatment had been removed, the assisted enucleation rate was >80%, whereas it was approximately 32% with blind enucleation.

[Study on Maternal Periodontal Diseases of the Relationships Between Porphyromonas Gingivalis, Serum Pro-immflamatory Mediators and Preterm Low Birth Weight]

To investigate the associations between periodontal diseases, presence of Porphyromonas gingivalis (P. gingivalis), serum levels of pro-inflammatory mediators and preterm low birth weight (PLBW).

Immunomodulation by Hepatitis C Virus-derived Proteins: Targeting Human Dendritic Cells by Multiple Mechanisms

Hepatitis C virus (HCV) has the ability to persist in the majority of infected people. Strong, multispecific and sustained T-cell response is correlated with viral clearance. The mechanisms of chronicity by HCV are unclear. HCV could restrain the immune system and establish chronic infection by modulating dendritic cell (DC) function, T-cell function or both. DC dysfunction has been postulated to be either due to direct HCV infection or by the presence of HCV proteins. In this report, for the first time, we have examined whether soluble HCV proteins can impair DC function or directly inhibit T-cell responses in the cells obtained from healthy uninfected people. Our studies revealed that different HCV proteins used distinct mechanisms to down-regulate DC functions. Individual HCV proteins, Core, NS3, NS4, NS5 as well as fused Polyprotein (Core-NS3-NS4) were found to impair functions of both immature DCs and mature DCs by regulating the expression of co-stimulatory and antigen presentation molecules, strikingly reducing IL-12 secretion, inducing the expression of FasL to mediate apoptosis, interfering with allo-stimulatory capacity, inhibiting toll-like receptor signaling and inhibiting nuclear translocation of NFkappaB in DCs. Interestingly, HCV proteins did not directly inhibit T-cell proliferation. Our findings clearly demonstrate that HCV proteins impair T-cell responses indirectly by inhibiting DCs that could result in a sub-optimal cellular immune response allowing for persistent HCV infections. These studies delineate important mechanisms by which initial DC dysfunction can establish contributing to chronicity. Our data are in agreement with earlier observations that DCs are impaired in HCV infected people.

Effect of Bioaggregate on Mineral-associated Gene Expression in Osteoblast Cells

This study investigated the cytotoxicity of bioaggregate (BA) and the effect of BA on mineral associated gene expression in osteoblast cells.

Current Progress of Chinese Medicinal Treatment of Endometriosis

Endometriosis (EM) is one of the common and frequently encountered gynecological diseases that seriously influences women's health. Its morbidity reaches 10%-15% in women at reproductive ages, and shows an evident rising tendency. In recent years, the Chinese medicine treatment of EM has won favorable therapeutic effects with few adverse reactions. A brief review on this topic has been made through analyzing and summarizing recent pertinent literatures in terms of treatment depending on syndrome differentiation, cycle treatment, external treatment, integrative medicinal treatment, so as to try to know the status quo of Chinese medicine treatment on EM, and to provide some instructive views for clinical treatment and research.

[Video-assisted Thoracoscopic Radical Resection of Early-stage Non-small Cell Lung Cancer]

To study the reliability and feasibility of video-assisted thoracoscopic surgery (VATS) for radical resection of early-stage non-small cell lung cancer (NSCLC).

Experimental Study on the Therapeutic Effect of Positron Emission Tomography Agent [¹⁸F]-labeled 2-deoxy-2-fluoro-d-glucose in a Colon Cancer Mouse Model

The purpose of this study was to assess the therapeutic effect of positron emission tomography agent [¹⁸F]-labeled 2-deoxy-2-fluoro-d-glucose (¹⁸F-FDG) in a colorectal cancer mouse model. Three (3) tumor-bearing mice groups were treated with different doses of ¹⁸F-FDG. Mice were imaged by positron emission tomography with ¹⁸F-FDG before and after treatment weekly and the tumor growth rate was calculated. Tumor, brain, heart, and kidney of mice were analyzed for expression of glucose transporters and vascular endothelial growth factor (VEGF) by immunofluorescent staining, and the presence of apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) method. All 3 treated groups showed significant ¹⁸F-FDG reduction compared with the control group (p < 0.05). With higher treatment dose, better treatment response was observed. The tumor growth rate of all 3 treated groups was also significantly decreased after treatment (p < 0.05). Immunohistochemistry showed that tumors expressed more glucose transporters than in brain, heart, and kidney. The ¹⁸F-FDG treatment of mice resulted in apoptotic cell death in all 3 treated groups, which showed significant higher apoptotic cells than the control group (p < 0.05). The study suggests that ¹⁸F-FDG has a therapeutic effect in colonic cancer animal model, which indicates the potential for the development of positron therapy for colonic cancer and other cancers.

[Study of Dental Caries and the Influence of Social-behavioral Risk Factors on Dental Caries of 1,080 15-year-old Adolescents]

To describe the dental caries of 15-year-old adolescents in Hubei province, and to determine the influence of various social-behavioral risk factors on dental caries in the population.

In Vivo Imaging of Embryonic Stem Cell Therapy

Embryonic stem cells (ESCs) have the most pluripotent potential of any stem cell. These cells, isolated from the inner cell mass of the blastocyst, are "pluripotent," meaning that they can give rise to all cell types within the developing embryo. As a result, ESCs have been regarded as a leading candidate source for novel regenerative medicine therapies and have been used to derive diverse cell populations, including myocardial and endothelial cells. However, before they can be safely applied clinically, it is important to understand the in vivo behavior of ESCs and their derivatives. In vivo analysis of ESC-derived cells remains critically important to define how these cells may function in novel regenerative medicine therapies. In this review, we describe several available imaging modalities for assessing cell engraftment and discuss their strengths and limitations. We also analyze the applications of these modalities in assessing the utility of ESCs in regenerative medicine therapies.

Simultaneous Reduction-etching Route to Pt/ZnSnO3 Hollow Polyhedral Architectures for Methanol Electrooxidation in Alkaline Media with Superior Performance

In this communication, a simultaneous reduction-etching route is exploited to fabricate Pt/ZnSnO(3) hollow polyhedra. The hollow ZnSnO(3) polyhedron is found to act as a novel and efficient support of Pt-based catalyst for methanol electrooxidation in alkaline media.

[Randomized Clinical Case-control Trial for the Comparison of Docetaxel Plus Thiotepa Versus Docetaxel Plus Capecitabine in Patients with Metastatic Breast Cancer]

To evaluate the efficacy and safety of docetaxel plus thiotepa(TXT/TSPA) and docetaxel plus capecitabine(TXT/CAPE) in patients with metastatic breast cancer.

Silver and Gold Icosahedra: One-pot Water-based Synthesis and Their Superior Performance in the Electrocatalysis for Oxygen Reduction Reactions in Alkaline Media

Much effort has gone into generating polyhedral noble metal nanostructures because of their superior electrocatalytic activities for fuel cells. Herein, we report uniform, high-yield icosahedral silver and gold nanoparticles by using a facile one-pot, seedless, water-based approach that incorporates polyvinyl pyrrolidone and ammonia. Electrocatalysis of the oxygen-reduction reaction was carried out in alkaline media to evaluate the performance of the icosahedral nanoparticles. They showed excellent stability and much higher electrocatalytic activity than the spherelike nanoparticles; they display a positive shift in reduction peak potential for O(2) of 0.14 and 0.05 V, while the reduction peak currents of the silver and gold icosahedra are 1.5- and 1.6-fold, respectively, better than the spherelike nanoparticles. More importantly, the icosahedral nanoparticles display electrocatalytic activities comparable with commercial Pt/C electrocatalysts. The facile preparation of icosahedral silver and gold nanoparticles and their superior performance in the oxygen reduction reaction render them attractive replacements for Pt as cathode electrocatalysts in alkaline fuel cells.

Scleraxis is Required for Differentiation of the Stapedius and Tensor Tympani Tendons of the Middle Ear

Scleraxis (Scx) is a basic helix-loop-helix transcription factor expressed in tendon and ligament progenitor cells and the differentiated cells within these connective tissues in the axial and appendicular skeleton. Unexpectedly, we found expression of the Scx transgenic reporter mouse, Scx-GFP, in interdental cells, sensory hair cells, and cochlear supporting cells at embryonic day 18.5 (E18.5). We evaluated Scx-null mice to gain insight into the function of Scx in the inner ear. Paradoxical hearing loss was detected in Scx-nulls, with ~50% of the mutants presenting elevated auditory thresholds. However, Scx-null mice have no obvious, gross alterations in cochlear morphology or cellular patterning. Moreover, we show that the elevated auditory thresholds correlate with middle ear infection. Laser interferometric measurement of sound-induced malleal movements in the infected Scx-nulls demonstrates increased impedance of the middle ear that accounts for the hearing loss observed. The vertebrate middle ear transmits vibrations of the tympanic membrane to the cochlea. The tensor tympani and stapedius muscles insert into the malleus and stapes via distinct tendons and mediate the middle ear muscle reflex that in part protects the inner ear from noise-induced damage. Nothing, however, is known about the development and function of these tendons. Scx is expressed in tendon progenitors at E14.5 and differentiated tenocytes of the stapedius and tensor tympani tendons at E16.5-18.5. Scx-nulls have dramatically shorter stapedius and tensor tympani tendons with altered extracellular matrix consistent with abnormal differentiation in which condensed tendon progenitors are inefficiently incorporated into the elongating tendons. Scx-GFP is the first transgenic reporter that identifies middle ear tendon lineages from the time of their formation through complete tendon maturation. Scx-null is the first genetically defined mouse model for abnormal middle ear tendon differentiation. Scx mouse models will facilitate studies of tendon and muscle formation and function in the middle ear.

One-step Radiosynthesis of ¹⁸F-AlF-NOTA-RGD₂ for Tumor Angiogenesis PET Imaging

One of the major obstacles of the clinical translation of (18)F-labeled arginine-glycine-aspartic acid (RGD) peptides has been the laborious multistep radiosynthesis. In order to facilitate the application of RGD-based positron emission tomography (PET) probes in the clinical setting we investigated in this study the feasibility of using the chelation reaction between Al(18)F and a macrocyclic chelator-conjugated dimeric RGD peptide as a simple one-step (18)F labeling strategy for development of a PET probe for tumor angiogenesis imaging.

In Vitro Study on Apoptosis Induced by Strontium-89 in Human Breast Carcinoma Cell Line

Many radiopharmaceuticals used for medical diagnosis and therapy are beta emitters; however, the mechanism of the cell death caused by beta-irradiation is not well understood. The objective of this study was to investigate the apoptosis of human breast carcinoma MCF-7 cell lines induced by Strontium-89 (⁸⁹Sr) and its regulation and control mechanism. High-metastatic Breast Carcinoma MCF-7 cells were cultured in vitro using ⁸⁹Sr with different radioactive concentration. The inhibition rate of cell proliferation was measured by MTT color matching method. The cell cycle retardation, apoptosis conditions, mitochondrion transmembrane potential difference and Fas expression were tested and analyzed. The genes P53 and bcl-2 expressions was also analyzed using immunity histochemical analysis. After being induced by ⁸⁹Sr with various of radioactive concentration, it was found that the inhibition of cell proliferation of MCF-7 cells was obviously, the retardation of cell cycle occurred mainly in G2-M. It was also found that the obvious apoptosis occurred after being induced by ⁸⁹Sr, the highest apoptosis rate reached 46.28%. The expressions of Fas acceptor and P53 gene increased, while bcl-2 gene expression decreasesd. These findings demonstrate that in the ranges of a certain radioactive concentration, the inhibition rate of MCF-7 cell proliferation and retardation of cell cycle had positive correlation with the concentration of ⁸⁹Sr. And the mitochondrion transmembrane potential decrease would induce the apoptosis of MCF-7 cell notably, which were controlled by P53 and bcl-2 genes, involved with the Fas acceptor.

Non-invasive Imaging of Cysteine Cathepsin Activity in Solid Tumors Using a 64Cu-labeled Activity-based Probe

The papain family of cysteine cathepsins are actively involved in multiple stages of tumorigenesis. Because elevated cathepsin activity can be found in many types of human cancers, they are promising biomarkers that can be used to target radiological contrast agents for tumor detection. However, currently there are no radiological imaging agents available for these important molecular targets. We report here the development of positron emission tomography (PET) radionuclide-labeled probes that target the cysteine cathepsins by formation of an enzyme activity-dependent bond with the active site cysteine. These probes contain an acyloxymethyl ketone (AOMK) functional group that irreversibly labels the active site cysteine of papain family proteases attached to a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) tag for labeling with (64)Cu for PET imaging studies. We performed biodistribution and microPET imaging studies in nude mice bearing subcutaneous tumors expressing various levels of cysteine cathepsin activity and found that the extent of probe uptake by tumors correlated with overall protease activity as measured by biochemical methods. Furthermore, probe signals could be reduced by pre-treatment with a general cathepsin inhibitor. We also found that inclusion of a Cy5 tag on the probe increased tumor uptake relative to probes lacking this fluorogenic dye. Overall, these results demonstrate that small molecule activity-based probes carrying radio-tracers can be used to image protease activity in living subjects.

Randomized Controlled Trial on Fluoride Varnish Application for Treatment of White Spot Lesion After Fixed Orthodontic Treatment

The purpose of this study was to determine the efficacy of fluoride varnish (5% sodium fluoride, Duraphat(®), Colgate) in reverting white spot lesions (WSLs) after fixed orthodontic treatment. This study was a randomized, parallel group, controlled clinical trial. Using saline solution as control, 110 participants (mean age ± standard deviation: 16.6 ± 3.2 years) ranging from 12 to 22 years old were randomly assigned to either the test group (group 1) or the control group (group 2). Application of fluoride varnish or saline was applied onto tooth surfaces with WSLs every month during the first 6 months after debonding. The labial (buccal) surfaces of the teeth were assessed by the use of a DIAGNOdent pen (DD) at the baseline, 3- and 6-month follow-up visits. After 6 months, 96 subjects with a total of 209 study teeth (47 subjects, 104 teeth in group 1; 49 subjects, 105 teeth in group 2) remained. The WSLs had a mean DD reading at baseline of 17.66 ± 5.36 in group 1 and 16.19 ± 5.70 in group 2, which decreased by 5.78 and 2.44, respectively, at the 3-month follow-up visit and decreased by 7.56 and 3.09, respectively, at the 6-month follow-up visit. The mean baseline DD readings in the two groups were similar (t test, P > 0.05). There was statistically significant differences between the mean DD readings of the two groups at the 3-month (P < 0.05) and at the 6-month follow-up visits (P < 0.01). Topical fluoride varnish application is effective in reversing WSLs after debonding and should be advocated as a routine caries prevention measure after orthodontic treatment.

Proof-of-concept Study of Monitoring Cancer Drug Therapy with Cerenkov Luminescence Imaging

Cerenkov luminescence imaging (CLI) has emerged as a less expensive, easier-to-use, and higher-throughput alternative to other nuclear imaging modalities such as PET. It is expected that CLI will find many applications in biomedical research such as cancer detection, probe development, drug screening, and therapy monitoring. In this study, we explored the possibility of using CLI to monitor drug efficacy by comparisons against PET. To assess the performance of both modalities in therapy monitoring, 2 murine tumor models (large cell lung cancer cell line H460 and prostate cancer cell line PC3) were given bevacizumab versus vehicle treatments. Two common radiotracers, 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) and (18)F-FDG, were used to monitor bevacizumab treatment efficacy.

177Lu-DO3A-HSA-Z EGFR:1907: Characterization As a Potential Radiopharmaceutical for Radionuclide Therapy of EGFR-expressing Head and Neck Carcinomas

Epidermal growth factor receptor 1 (EGFR) is an attractive target for radionuclide therapy of head and neck carcinomas. Affibody molecules against EGFR (Z(EGFR)) show excellent tumor localizations in imaging studies. However, one major drawback is that radiometal-labeled Affibody molecules display extremely high uptakes in the radiosensitive kidneys which may impact their use as radiotherapeutic agents. The purpose of this study is to further explore whether radiometal-labeled human serum albumin (HSA)-Z(EFGR) bioconjugates display desirable profiles for the use in radionuclide therapy of EGFR-positive head and neck carcinomas. The Z(EFGR) analog, Ac-Cys-Z(EGFR:1907), was site-specifically conjugated with HSA. The resulting bioconjugate 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A)-HSA-Z(EGFR:1907) was then radiolabeled with either (64)Cu or (177)Lu and subjected to in vitro cell uptake and internalization studies using the human oral squamous carcinoma cell line SAS. Positron emission tomography (PET), single photon emission computed tomography (SPECT), and biodistribution studies were conducted using SAS-tumor-bearing mice. Cell studies revealed a high (8.43 ± 0.55 % at 4 h) and specific (0.95 ± 0.09 % at 4 h) uptake of (177)Lu-DO3A-HSA-Z(EGFR:1907) as determined by blocking with nonradioactive Z(EGFR:1907). The internalization of (177)Lu-DO3A-HSA-Z(EGFR:1907) was verified in vitro and found to be significantly higher than that of (177)Lu-labeled Z(EFGR) at 2-24 h of incubation. PET and SPECT studies showed good tumor imaging contrasts. The biodistribution of (177)Lu-DO3A-HSA-Z(EGFR:1907) in SAS-tumor-bearing mice displayed high tumor uptake (5.1 ± 0.44 % ID/g) and liver uptake (31.5 ± 7.66 % ID/g) and moderate kidney uptake (8.5 ± 1.08 % ID/g) at 72 h after injection. (177)Lu-DO3A-HSA-Z(EGFR:1907) shows promising in vivo profiles and may be a potential radiopharmaceutical for radionuclide therapy of EGFR-expressing head and neck carcinomas.

Molecular Imaging in Tracking Tumor Stem-like Cells

Cancer remains a major public health problem in many countries. It was found to contain a subset of cancer stem cells (CSCs) that are capable of proliferation and self-renewal, and differentiation into various types of cancer cells. CSCs often display characteristics of chemotherapy resistance and radiotherapy resistance. Numerous putative biomarkers of CSCs are currently identified including CD133, CD44, CD24, ALDH (aldehyde dehydrogenase), and ABCG2. Interestingly, no single marker is exclusively expressed by CSCs. Thus, the various combinations of different biomarkers will be possible to identify CSCs, and considerable work is being done to recognize new ones. In order to demonstrate the mechanisms of resistance and response to therapy and predict the outcome as well as prognosis, the ways to track and identify CSCs will be extremely important. The technologies of molecular imaging will reveal mechanisms of cancer progression and provide visual targets for novel therapeutics. Limited studies were investigated on the detection of various types of CSCs by molecular imaging. Although the tracking of circulating CSCs is still hampered by technological challenges, personalized diagnosis and therapies of cancers are expected to be established based on increased understanding of molecular imaging of cancer stem-like cells biomarkers.

Synthesis of Galactosylated Chitosan/5-fluorouracil Nanoparticles and Its Characteristics, in Vitro and in Vivo Release Studies

Biodegradable polymer nanoparticle drug delivery systems are characterized by targeted drug delivery, improved pharmacokinetic and biodistribution, enhanced drug stability, and lowered side effects; these drug delivery systems are widely used for delivery of cytotoxic agents. The galactosylated chitosan (GC)/5-fluorouracil (5-FU) nanoparticle is a nanomaterial made by coupling GC, a polymer known to have the advantages described above, and 5-FU. We found that when 5-FU and GC were mixed at the mass ratio of 10:1, the nanoparticle reached a maximum encapsulation efficiency of 81.82% ± 5.32%, with a drug loading of 6.12% ± 1.36%, a particle size of 35.19 ± 9.50 nm, and a Zeta potential of +10.34 ± 1.43 mV. The GC/5-FU nanoparticle is a sustained release system, whose anticancer effects were shown to be dose and time dependent, with a higher cytotoxicity to hepatic cancer than to other cell types. The distribution of GC/5-FU in vivo revealed the greatest accumulation in the hepatic cancer tissues, with an 8.69-, 23.35-, 79.96-, and 85.15-fold increase when compared to normal liver tissue, kidney, heart and blood, respectively, suggesting that the hepatic cell was the target of the nanoparticles. In vivo experiments showed that GC/5-FU can significantly inhibit tumor growth in an orthotropic liver cancer mouse model. GC/5-FU treatment can significantly lower the tumor weight and increase the survival time of mice when compared to 5-FU treatment alone. Flow cytometry revealed that compared to 5-FU, GC/5-FU caused higher rates of G0-G1 arrest and apoptosis in hepatic cancer cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.

Intraoperative Imaging of Tumors Using Cerenkov Luminescence Endoscopy: a Feasibility Experimental Study

Cerenkov luminescence imaging (CLI) is an emerging new molecular imaging modality that is relatively inexpensive, easy to use, and has high throughput. CLI can image clinically available PET and SPECT probes using optical instrumentation. Cerenkov luminescence endoscopy (CLE) is one of the most intriguing applications that promise potential clinical translation. We developed a prototype customized fiberscopic Cerenkov imaging system to investigate the potential in guiding minimally invasive surgical resection.

Evaluation of in Vivo Antioxidant and Immunity Enhancing Activities of Sodium Aescinate Injection Liquid

Oxidative stress is involved in the development and progression of disease. Because sodium aescinate has been reported to have immunity enhancing and antioxidative effects, we investigated its activity by employing a hepatocellular carcinoma (HCC) mouse model. Sixty BALB/c mice were randomly divided into four groups, including a 1.4 mg/kg treated group (n = 15), a 2.8 mg/kg treated group (n = 15), an untreated hepatocellular carcinoma control group (n = 15) and a normal control group (n = 15). After H22 cells were cultured for one week, we collected 2 × 10⁶ cells and injected them subcutaneously as 0.2 mL cell suspensions in sterile saline into the right shoulder region of every mouse. The animals were monitored for changes in activity, physical condition and body weight during the experiment. The next day after injection of H22 cells, animals in these test groups received one intraperitoneal injection of drug or physiological saline for 13 days. Results showed that in the sodium aescinate injection liquid (SAIL)-treated HCC mice, serum interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), Gamma-glutamyltransferase (γ-GT), alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) levels were significantly decreased compared with normal control mice. In addition, treatment with sodium aescinate injection liquid significantly decreased blood and liver malondialdehyde (MDA) levels, increased glutathione (GSH) levels, and antioxidant enzyme [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px)] activities in a dose-dependent manner. We conclude that sodium aescinate injection liquid can decrease oxidative injury and enhance immunity functions in HCC mice.

A Novel Radiofluorinated Agouti-related Protein for Tumor Angiogenesis Imaging

A novel protein scaffold based on the cystine knot domain of the agouti-related protein (AgRP) has been used to engineer mutants that can bind to the α(v)β(3) integrin receptor with high affinity and specificity. In the current study, an (18)F-labeled AgRP mutant (7C) was prepared and evaluated as a positron emission tomography (PET) probe for imaging tumor angiogenesis. AgRP-7C was synthesized by solid phase peptide synthesis and site-specifically conjugated with 4-nitrophenyl 2-(18/19)F-fluoropropionate ((18/19)F-NFP) to produce the fluorinated peptide, (18/19)F-FP-AgRP-7C. Competition binding assays were used to measure the relative affinities of AgRP-7C and (19)F-FP-AgRP-7C to human glioblastoma U87MG cells that overexpress α(v)β(3) integrin. In addition, biodistribution, metabolic stability, and small animal PET imaging studies were conducted with (18)F-FP-AgRP-7C using U87MG tumor-bearing mice. Both AgRP-7C and (19)F-FP-AgRP-7C specifically competed with (125)I-echistatin for binding to U87MG cells with half maximal inhibitory concentration (IC(50)) values of 9.40 and 8.37 nM, respectively. Non-invasive small animal PET imaging revealed that (18)F-FP-AgRP-7C exhibited rapid and good tumor uptake (3.24 percentage injected dose per gram [% ID/g] at 0.5 h post injection [p.i.]). The probe was rapidly cleared from the blood and from most organs, resulting in excellent tumor-to-normal tissue contrasts. Tumor uptake and rapid clearance were further confirmed with biodistribution studies. Furthermore, co-injection of (18)F-FP-AgRP-7C with a large molar excess of blocking peptide c(RGDyK) significantly inhibited tumor uptake in U87MG xenograft models, demonstrating the integrin-targeting specificity of the probe. Metabolite assays showed that the probe had high stability, making it suitable for in vivo applications. (18)F-FP-AgRP-7C exhibits promising in vivo properties such as rapid tumor targeting, good tumor uptake, and excellent tumor-to-normal tissue ratios, and warrants further investigation as a novel PET probe for imaging tumor angiogenesis.

The Preliminary Pharmacology of Galactosylated Chitosan/5-fluorouracil Nanoparticles and Its Inhibition of Hepatocellular Carcinoma in Mice

Biodegradable polymer nanoparticle drug delivery systems are characterized by targeted drug delivery, improved pharmacokinetic and biodistribution, enhanced drug stability and lowered side effects; these drug delivery systems are widely used for delivery of cytotoxic agents. The galactosylated chitosan (GC)/5-fluorouracil (5-FU) nanoparticle is a nanomaterial made by coupling GC, a polymer known to have the advantages described above, and 5-FU. The GC/5-FU nanoparticle is a sustained release system, it was showed that the peak time, half-life time, mean residence time (MRT) and area of under curve (AUC) of GC/5-FU were longer or more than those of the 5-FU group, but the Cmax was lower. The distribution of GC/5-FU in vivo revealed the greatest accumulation in the hepatic cancer tissues, and the hepatic cell was the target of the nanoparticles. Toxicology research showed that the toxicity of GC-5-FU was lower than that of 5-FU in mice. In vivo experiments showed that GC/5-FU can significantly inhibit tumor growth in an orthotropic liver cancer mouse model. GC/5-FU treatment can significantly lower the tumor weight and in-crease the survival time of mice when compared to 5-FU treatment alone. Flow cytometry and the TUNEL assay revealed that compared to 5-FU, GC/5-FU caused higher rates of G0-G1 arrest and apoptosis in hepatic cancer cells.

5-Fluorouracil Nanoparticles Inhibit Hepatocellular Carcinoma Via Activation of the P53 Pathway in the Orthotopic Transplant Mouse Model

Biodegradable polymer nanoparticle drug delivery systems provide targeted drug delivery, improved pharmacokinetic and biodistribution, enhanced drug stability and fewer side effects. These drug delivery systems are widely used for delivering cytotoxic agents. In the present study, we synthesized GC/5-FU nanoparticles by combining galactosylated chitosan (GC) material with 5-FU, and tested its effect on liver cancer in vitro and in vivo. The in vitro anti-cancer effects of this sustained release system were both dose- and time-dependent, and demonstrated higher cytotoxicity against hepatic cancer cells than against other cell types. The distribution of GC/5-FU in vivo revealed the greatest accumulation in hepatic cancer tissues. GC/5-FU significantly inhibited tumor growth in an orthotropic liver cancer mouse model, resulting in a significant reduction in tumor weight and increased survival time in comparison to 5-FU alone. Flow cytometry and TUNEL assays in hepatic cancer cells showed that GC/5-FU was associated with higher rates of G0-G1 arrest and apoptosis than 5-FU. Analysis of apoptosis pathways indicated that GC/5-FU upregulates p53 expression at both protein and mRNA levels. This in turn lowers Bcl-2/Bax expression resulting in mitochondrial release of cytochrome C into the cytosol with subsequent caspase-3 activation. Upregulation of caspase-3 expression decreased poly ADP-ribose polymerase 1 (PARP-1) at mRNA and protein levels, further promoting apoptosis. These findings indicate that sustained release of GC/5-FU nanoparticles are more effective at targeting hepatic cancer cells than 5-FU monotherapy in the mouse orthotropic liver cancer mouse model.

Novel, Cysteine-Modified Chelation Strategy for the Incorporation of [M(I)(CO)(3)](+) (M = Re, (99m)Tc) in an α-MSH Peptide

Engineering peptide-based targeting agents with residues for site-specific and stable complexation of radionuclides is a highly desirable strategy for producing diagnostic and therapeutic agents for cancer and other diseases. In this report, a model N-S-N(Py) ligand (3) and a cysteine-derived α-melanocyte stimulating hormone (α-MSH) peptide (6) were used as novel demonstrations of a widely applicable chelation strategy for incorporation of the [M(I)(CO)(3)](+) (M = Re, (99m)Tc) core into peptide-based molecules for radiopharmaceutical applications. The structural details of the core ligand-metal complexes as model systems were demonstrated by full chemical characterization of fac-[Re(I)(CO)(3)(N,S,N(Py)-3)](+) (4) and comparative high-performance liquid chromatography (HPLC) analysis between 4 and [(99m)Tc(I)(CO)(3)(N,S,N(Py)-3)](+) (4a). The α-MSH analogue bearing the N-S-N(Py) chelate on a modified cysteine residue (6) was generated and complexed with [M(I)(CO)(3)](+) to confirm the chelation strategy's utility when applied in a peptide-based targeting agent. Characterization of the Re(I)(CO)(3)-6 peptide conjugate (7) confirmed the efficient incorporation of the metal center, and the (99m)Tc(I)(CO)(3)-6 analogue (7a) was explored as a potential single photon emission computed tomography (SPECT) compound for imaging the melanocortin 1 receptor (MC1R) in melanoma. Peptide 7a showed excellent radiolabeling yields and in vitro stability during amino acid challenge and serum stability assays. In vitro B16F10 melanoma cell uptake of 7a reached a modest value of 2.3 ± 0.08% of applied activity at 2 h at 37 °C, while this uptake was significantly reduced by coincubation with a nonlabeled α-MSH analogue, NAPamide (3.2 μM) (P < 0.05). In vivo SPECT/X-ray computed tomography (SPECT/CT) imaging and biodistribution of 7a were evaluated in a B16F10 melanoma xenografted mouse model. SPECT/CT imaging clearly visualized the tumor at 1 h post injection (p.i.) with high tumor-to-background contrast. Blocking studies with coinjected NAPamide (10 mg per kg of mouse body weight) confirmed the in vivo specificity of 7a for MC1R-positive tumors. Biodistribution results with 7a yielded a moderate tumor uptake of 1.20 ± 0.09 percentage of the injected radioactive dose per gram of tissue (% ID/g) at 1 h p.i. Relatively high uptake of 7a was also seen in the kidneys and liver at 1 h p.i. (6.55 ± 0.36% ID/g and 4.44 ± 0.17% ID/g, respectively), although reduced kidney uptake was seen at 4 h p.i. (3.20 ± 0.48% ID/g). These results demonstrate the utility of the novel [M(I)(CO)(3)](+) chelation strategy when applied in a targeting peptide.

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