Biomedical subjects

J Wang

Publications and source records attributed to J Wang.

At least 91 records · Page 5Linked to original sources

PubMed2006

Primary glioma spheroids maintain tumourogenicity and essential phenotypic traits after cryopreservation.

Tumour spheroids initiated from glioma biopsy specimens provide a valuable three-dimensional cell culture system that share several biological features of malignant brain tumours in situ. Upon xenotransplantation in immunodeficient rats, tumours derived from such spheroids exhibit a highly infiltrative growth. Successful cryopreservation of spheroid specimens therefore represents an excellent tool for future comparative studies of tumour growth and progression. Thus, if frozen stocks of human glioma spheroids can be established, similar to those obtained from cancer cell lines, it would ease the planning of biopsy-based experiments. In this context, it is crucial that cryopreservation does not alter the biological behaviour of the tumour spheroids. The biopsy spheroids were frozen to -40 degrees Celsius, stored for 1 week at -196 degrees Celsius, thawed rapidly and cultured for 1 week. The viability of the spheroids was compared against controls using a two-colour fluorescence assay, which demonstrated that cryopreservation was well tolerated. Using an in vitro invasion assay, it is shown that the freezing procedures did not affect the spheroids ability to invade a collagen gel. Cryopreserved and control tumour spheroids were equally tumourogenic, and produced overlapping survival curves when transplanted into the brains of immunocompromised rats. Immunohistochemical analyses showed no significant changes regarding microvessel density or proliferation index. Furthermore, gene expression profiling using a macroarray system detected no significant changes following cryopreservation. The present data show that cryopreservation is well tolerated, and represent a methodologically reliable storage method for biopsy spheroids that can be used in experimental studies at later time points.

Animals↗

PubMed2006

Chimaeric protein improved immunogenicity compared with fusion protein of Ag85B and ESAT-6 antigens of Mycobacterium tuberculosis.

Antigen 85B (Ag85B) and ESAT-6 are important immunodominant antigens of Mycobacterium tuberculosis, and both are very promising vaccine candidate molecules. In this study, we relied on the T-cell epitopes of Ag85B and ESAT-6 to design a chimaeric protein by inserting ESAT-6 into Ag85B from the amino acids 167-182. We found the ratio of IgG2b/IgG1 and the secretion of interferon (IFN)-gamma in the mice vaccinated with the new protein with adjuvant MPL and TDM were higher than the mice immunized with fusion protein Ag85B-ESAT-6, which have been reported and could induce levels of protective immunity similar to BCG in the mouse model of tuberculosis (TB) infection. These results suggest that the chimaeric protein Ag85B(N)-ESAT-6-Ag85B(C) is a strong candidate for further study and the T-cell epitopes of the antigens should be considered when we design the subunit vaccine.

Acyltransferases↗

PubMed2006

Characterization of HLA-B5516, -B1313, -B9512, and -DRB11457 alleles identified in a southwest Chinese population.

The human leukocyte antigen (HLA)-B*5516 allele differs from the B*5502 by a single 97 T --> C substitution (His to Tyr at position 33) in exon 2. The B*1313 allele results from 419 T --> A and 420 A --> C substitutions, encoding a Leu to Tyr substitution at 140 in exon 2 of the B*1301 allele. The B*9512 allele differs from B*1502 by a single 360 G --> C substitution (Gln to His at 120) in exon 3. The DRB1*1457 allele appears to be a hybrid molecule generated by recombination between the DRB1*13 and DRB1*14 alleles. The serological equivalents of these new alleles are HLA-B22, -B13, -B15, and DR13, respectively. Family studies detected two rare haplotypes: A*11, B*9512, DRB1*14 and A*24, B*52, Cw*07, DRB1*1457, DRB3*020201, DQB1*050301. The gene frequencies of these alleles in the Chinese population are less than 0.0001.

Alleles↗

PubMed2006

Genetics of sex pheromone blend differences between Heliothis virescens and Heliothis subflexa: a chromosome mapping approach.

Males of the noctuid moths, Heliothis virescens and H. subflexa locate mates based on species-specific responses to female-emitted pheromones that are composed of distinct blends of volatile compounds. We conducted genetic crosses between these two species and used AFLP marker-based mapping of backcross families (H. subflexa direction) to determine which of the 30 autosomes in these moths contained quantitative trait loci (QTL) controlling the proportion of specific chemical components in the pheromone blends. Presence/absence of single H. virescens chromosomes accounted for 7-34% of the phenotypic variation among backcross females in seven pheromone components. For a set of three similar 16-carbon acetates, two H. virescens chromosomes interacted in determining their relative amounts within the pheromone gland and together accounted for 53% of the phenotypic variance. Our results are discussed relative to theories about population genetic processes and biochemical mechanisms involved in the evolution of new sexual communication systems.

Animals↗

PubMed2006

Increased calcium deposits and decreased Ca2+-ATPase in right ventricular myocardium of ascitic broiler chickens.

Right ventricular hypertrophy and failure is an important step in the development of ascites syndrome (AS) in broiler chickens. Cytoplasmic calcium concentration is a major regulator of cardiac contractile function and various physiological processes in cardiac muscle cells. The purpose of this study was to measure the right ventricular pressure and investigate the precise ultrastructural location of Ca(2+) and Ca(2+)-ATPase in the right ventricular myocardium of chickens with AS induced by low ambient temperature. The results showed that the right ventricular diastolic pressure of ascitic broilers was significantly higher than that of control broilers (P < 0.01), and the maximum change ratio of right intraventricular pressure (RV +/- dp/dt(max)) of ascitic broilers was significantly lower than that of the controls (P < 0.01). Extensively increased calcium deposits were observed in the right ventricular myocardium of ascitic broilers, whereas in the age-matched control broilers, calcium deposits were much less. The Ca(2+)-ATPase reactive products were obviously found on the sarcoplasmic reticulum and mitochondrial membrane of the control right ventricular myocardium, but rarely observed in the ascitic broilers. The data suggest that in ascitic broilers there is the right ventricular diastolic dysfunction, in which the overload of intracellular calcium and the decreased Ca(2+)-ATPase activity might be the important factors.

Animals↗

PubMed2006

Stiff skin syndrome.

Stiff skin syndrome is a rare disorder characterized by pronounced skin induration, mild hypertrichosis and limited joint mobility, predominantly on the buttocks and thighs. Many heterogeneous cases have been reported under the name of stiff skin syndrome. We present a case of stiff skin syndrome from China, the diagnosis based on the patient's typical clinical and histopathological features.

Child, Preschool↗

PubMed2006

Enabling a powerful marine and offshore decision-support solution through Bayesian network technique.

A powerful practical solution is by far the most desired output when making decisions under the realm of uncertainty on any safety-critical marine or offshore units and their systems. With data and information typically being obtained incrementally, adopting Bayesian network (BN) is shown to realistically deal with the random uncertainties while at the same time making risk assessments easier to build and to check. A well-matched methodology is proposed to formalize the reasoning in which the focal mechanism of inference processing relies on the sound Bayes's rule/theorem that permits the logic. Expanding one or more influencing nodal parameters with decision and utility node(s) also yields an influence diagram (ID). BN and ID feasibility is shown in a marine evacuation scenario and that of authorized vessels to floating, production, storage, and offloading collision, developed via a commercial computer tool. Sensitivity analysis and validation of the produced results are also presented.

Accidents, Occupational↗

PubMed2006

A mouse model for polyomavirus-associated nephropathy of kidney transplants.

Polyomavirus-associated nephropathy is an important cause of dysfunction and failure of renal transplants. BK virus is an ubiquitous human polyoma virus that persistently infects the kidney. This otherwise silent infection can reactivate in immunosuppressed individuals, resulting in renal complications. Because polyoma viruses are highly species-specific, we developed a mouse polyoma virus-renal transplant model in order to investigate the pathogenesis of polyomavirus-associated nephropathy. Using this model, we found that polyoma virus preferentially replicates in the allogeneic kidney grafts, accelerating graft failure; thus, this animal model is able to mimic the polyomavirus-associated nephropathy seen in human renal transplant patients. Acute polyoma virus infection of mouse allograft recipients augmented the alloreactive CD8+ T-cell response, while maintaining the anti-viral CD8+ T-cell response. In addition to the known virus-induced cytopathology, these findings demonstrate a potential role for an enhanced anti-donor T-cell response in the pathogenesis of polyomavirus-associated nephropathy.

Animals↗

PubMed2006

NOD mouse model for Sjögren's syndrome: lack of longitudinal stability.

OBJECTIVES: The non-obese diabetic (NOD) mouse is not only a widely used model for diabetes mellitus type I, but also for the chronic autoimmune disease Sjögren's syndrome (SS), mainly affecting salivary and lacrimal glands. We studied the efficacy of local recombinant serotype 2 adeno-associated viral (rAAV2) vector transfer of immunomodulatory transgenes to alter the SS-like disease in NOD mice. Data collected over a 2-year period indicated a changing SS phenotype in these mice and this phenomenon was investigated. METHODS: 10(10) particles rAAV2LacZ/gland were delivered to both submandibular glands (SMGs) of NOD/LtJ mice at 8 weeks (before sialadenitis onset) of age. Salivary flow rates were determined at 8 weeks and time of killing. Blood glucose levels and body weights were measured weekly. After killing, saliva and SMGs were harvested. Analyses of salivary output, inflammatory infiltrates (focus score), SMG cytokine profile, body weight, and diabetes mellitus status were performed. Data from six different experimental studies over 2 years were analyzed and compared. RESULTS: Salivary flow rate, focus score, and SMG cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12(p70), tumor necrosis factor-alpha and IFNgamma showed changes over time. There were no differences for body weight, diabetes mellitus prevalence, or blood glucose level of non-diabetic mice. CONCLUSION: This retrospective report is the first to describe longitudinal variability in the NOD mouse as a model for SS. We advise other investigators to continuously monitor the SS phenotype parameters and include appropriate controls when studying this disease in NOD mice.

Analysis of Variance↗

PubMed2006

Sequencing-based analysis of the HLA-DPB1 polymorphism in Nu ethnic group of south-west China.

In the present study, DNA typing for HLA-DPB1 was performed using polymerase chain reaction-sequencing-based typing method in 72 randomly selected Nu ethnic individuals inhabiting the Yunnan province of south-west China. Among the 12 detected DPB1 alleles, the most frequent was DPB1*1301, with the percentage of 20.83%, followed by DPB1*0501 (19.44%), DPB1*040101 (16.67%) and DPB1*2801 (9.72%). The allele DPB1*1501 was found for the first time in the Chinese population. Neighbour-joining showed that the Nu ethnic minority belonged to East Asian cluster and was most closely related to Lisu, being consistent with the historical records. In addition, the results obtained in this study will also provide useful information on organ transplantation, forensic investigations and disease association studies.

China↗

PubMed2006

A cohort study of 20,822 young drivers: the DRIVE study methods and population.

BACKGROUND AND OBJECTIVE: Research on young drivers directly linking risk factors to serious injury and death outcomes is required. The DRIVE Study was established to facilitate this aim. This paper outlines the study methods and describes the population that has been recruited, in order to demonstrate that the necessary heterogeneity in risk factors has been attained. DESIGN, SETTING AND PARTICIPANTS: Drivers aged 17-24 years holding their first-stage provisional driver's licence from New South Wales, Australia, were recruited into a prospective cohort study. The participants were contacted by mail and asked to complete the study questionnaire at an online site or via a mailed questionnaire. Baseline data collection involved a questionnaire with questions to drivers about their training, risk perception, driver behavior, sensation-seeking behavior and mental health. Participants gave consent for prospective data linkage to their data on licensing, crashes and injuries, held in routinely collected databases. RESULTS: 20 822 drivers completed the baseline questionnaire, of whom 45.4% were men, 74.3% resided in capital cities and 25.7% in regional or remote areas. The recruited study population showed a wide variation in the risk factors under examination. For example, almost 40% of drivers reported drinking alcohol at hazardous levels and about 32% of participants seemed to be at a high or very high risk of psychological distress. Participants reported a mean of 67.3 h (median 60 h) of supervised driver training while holding their learner's permit. CONCLUSIONS: The DRIVE Study has a robust study design aimed at minimizing bias in the collection of outcome data. Analyses of baseline data showed substantial heterogeneity of risk factors in the study population. Subsequent prospective linkages comparing relative differences in exposures at baseline with the outcomes of interest have the potential to provide important new information needed to develop targeted interventions aimed at young drivers.

Accidents, Traffic↗

PubMed2006

RAPD analysis of jasmine rice-specific genomic structure.

Total genomic DNA was extracted from 29 samples of rice seed, including jasmine rice Oryza sativa L. subsp indica 'KDML105', 'KDML105'-derived varieties, nonaromatic Thailand rice, and japonica rice. Polymorphism in RAPD profiles was analyzed to explore the genomic structure specific to jasmine rice. The degree of band sharing was used to evaluate genetic distance between varieties and to construct a phylogenetic tree. RD15, CNTLR85033, and CNT87040 were found to be closest to 'KDML105', which was consistent with the true relation among them. Four RAPD fragments that cooperatively distinguished jasmine rice from others were cloned and sequenced. PCR amplification using pairs of primers designed specifically further confirmed the credibility of the RAPD result. Comparison through Genbank revealed that a 454 bp RAPD band was similar to the first intron of a putative Cf2/Cf5 disease resistance gene and a 1,107 bp RAPD band similar to a wall-associated kinase (wak) gene sequence.

Crosses, Genetic↗

PubMed2006

Karyotypic evolution of the family Sciuridae: inferences from the genome organizations of ground squirrels.

Cross-species chromosome painting has made a great contribution to our understanding of the evolution of karyotypes and genome organizations of mammals. Several recent papers of comparative painting between tree and flying squirrels have shed some light on the evolution of the family Sciuridae and the order Rodentia. In the present study we have extended the comparative painting to the Himalayan marmot (Marmotahimalayana) and the African ground squirrel (Xerus cf. erythropus), i.e. representative species from another important squirrel group--the ground squirrels--, and have established genome-wide comparative chromosome maps between human, eastern gray squirrel, and these two ground squirrels. The results show that 1) the squirrels so far studied all have conserved karyotypes that resemble the ancestral karyotype of the order Rodentia; 2) the African ground squirrels could have retained the ancestral karyotype of the family Sciuridae. Furthermore, we have mapped the evolutionary rearrangements onto a molecular-based consensus phylogenetic tree of the family Sciuridae.

Animals↗

PubMed2006

Chromosomal mechanisms underlying the karyotype evolution of the oriental voles (Muridae, Eothenomys).

We have investigated the karyotype relationships of two oriental voles, i.e. the Yulong vole (Eothenomys proditor, 2n = 32) and the large oriental vole (Eothenomys miletus, 2n = 56) as well as the Clarke's vole (Microtus clarkei, 2n = 52), by a combined approach of cross-species chromosome painting and high-resolution G-banding comparison. Chromosome-specific painting probes were generated from flow-sorted chromosomes of E. proditor and hybridized onto metaphases of E. proditor, E. miletus and M. clarkei, leading to the establishment of genome-wide comparative chromosome maps. Our results demonstrate that Robertsonian translocations (centric fusions) have played a major role in the karyotype evolution of oriental voles with no obvious evidence for the involvement of tandem fusions as proposed previously and that the genome organizations of vole species are highly conserved. The comparative chromosome maps of these three vole species belonging to two phylogenetically distinct genera provide a framework for future studies on the karyotype evolution in voles.

Animals↗

PubMed2006

Karyotype relationships of six bat species (Chiroptera, Vespertilionidae) from China revealed by chromosome painting and G-banding comparison.

The Vespertilionidae is the largest family in the order Chiroptera and has a worldwide distribution in the temperate and tropical regions. In order to further clarify the karyotype relationships at the lower taxonomic level in Vespertilionidae, genome-wide comparative maps have been constructed between Myotis myotis (MMY, 2n = 44) and six vesper bats from China: Myotis altarium (MAL, 2n = 44), Hypsugo pulveratus (HPU, 2n = 44), Nyctalus velutinus (NVE, 2n = 36), Tylonycteris robustula (TRO, 2n = 32), Tylonycteris sp. (TSP, 2n = 30)and Miniopterus fuliginosus (MFU, 2n = 46) by cross-species chromosome painting with a set of painting probes derived from flow-sorted chromosomes of Myotis myotis. Each Myotis myotis autosomal probe detected a single homologous chromosomal segment in the genomes of these six vesper bats except for MMY chromosome 3/4 paint which hybridized onto two chromosomes in the genome of M. fuliginosus. Our results show that Robertsonian translocation is the main mode of karyotype evolution in Vespertilionidae and that the addition of heterochromatic material also plays an important role in the karyotypic evolution of the genera Tylonycteris and Nyctalus. Two conserved syntenic associations (MMY9 + 23 and 18 + 19) could be the synapomorphic features for the genus Tylonycteris. The integration of our maps with the published maps has enabled us to deduce chromosomal homologies between human and these six vesper bats and provided new insight into the karyotype evolution of the family Vespertilionidae.

Animals↗

PubMed2006

Postoperative transhepatic arterial chemoembolization and portal vein chemotherapy for patients with hepatocellular carcinoma: a randomized study with 131 cases.

OBJECTIVE: To explore the value of postoperative transarterial chemoembolization (TACE) and portal vein chemotherapy (PVC) in patients with hepatocellular carcinoma (HCC) in the prevention of recurrence, and to evaluate prognostic factors in a randomized study. METHOD: 131 patients with HCC were randomly divided into 3 groups: operation only (group A, n = 45); operation plus TACE (group B, n = 39), and operation plus TACE and PVC (group C, n = 47). Disease-free survival rates as well as prognostic factors were analyzed. RESULTS: Most of the side effects and complications related to the operation, catheters and local chemotherapy were liver decompensation (16.1%), catheter obstruction (12.9%), and nausea and loss of appetite (25.8%), respectively. The disease-free survival curves were significantly different between the 3 groups as estimated by the Kaplan-Meier method (p < 0.05). Group C had a significantly higher disease-free survival rate compared to group A (p < 0.05). But no statistical differences were found between groups A and B and groups B and C (both p > 0.05). Tumor number and treatment modalities were independent prognostic factors for HCC patients (p < 0.05). CONCLUSION: Postoperative TACE combined with PVC may benefit the survival of patients with HCC. In specialized medical centers, aggressive methods such as TACE and PVC should be attempted on HCC patients without contraindications.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2006

Effect of renal function on the pharmacokinetics of palifermin.

Palifermin (deltaN23KGF) decreases the incidence, severity, and duration of oral mucositis. The objectives of this open-label study were to evaluate the pharmacokinetics of single-dose palifermin in subjects with varying degrees of renal function. A single 90-mcg/kg intravenous dose of palifermin was administered to 31 subjects with varying levels of renal function (normal to requiring hemodialysis). Pharmacokinetic analyses were conducted using serum palifermin concentrations. There was considerable overlap in mean palifermin serum clearance among the groups, ranging from 318 to 495 mL/h/kg, indicating that the level of renal function did not affect clearance in humans; thus, no dose adjustment of palifermin is indicated for patients with renal dysfunction.

Adult↗

PubMed2006

Ectopic cartilage formation induced by mesenchymal stem cells on porous gelatin-chondroitin-hyaluronate scaffold containing microspheres loaded with TGF-beta1.

The study aimed to produce a novel porous gelatin-chondroitin-hyaluronate scaffold in combination with a controlled release of TGF- beta1 and to evaluate its potentials in ectopic cartilage formation. The gelatin-chondroitin-hyaluronate scaffold was developed to mimic the natural extra cellular matrix of cartilage. Gelatin microspheres loaded with TGF- beta1 (MS-TGF beta1) showed a fast cytokine release at initial phase (37.4%) and the ultimate accumulated release was 83.1% by day 18. Then MS-TGF beta1 were incorporated into scaffold. The MSCs seeded on scaffold with or without MS-TGF beta1 were incubated in vitro or implanted subcutaneously in nude mice. In vitro study showed that, compared to the scaffold, the scaffold/MS-TGF beta1 significantly augmented the proliferation of MSCs and GAG synthesis. Three weeks postoperatively histology observation showed that in MSCs/scaffold/MS-TGF beta1 implantation group, cells of newly formed ectopic cartilage were located within typical lacunae and demonstrated morphological characteristics of chondrocytes. Six weeks later the ectopic cartilage grew more and islands of cartilage were observed. The matrix was extensively metachromatic by safranin-O/Fast green staining. Immunohistochemical staining also indicated ectopic cartilage was intensely stained for type II collagen. Instead, in the MSCs/scaffold implantation group, no cartilage-like tissue formed and matrix showed negative or weak positive staining. The percentage of positive staining area was significantly larger in MSCs/scaffold/MS-TGF beta1 group (p<0.05) at each time point. The results indicated that the novel gelatin-chondroitin-hyaluronate scaffold with MS-TGF beta1 could induce the chondral differentiation of MSCs to form cartilage and might serve as a new way to repair cartilage defects.

Animals↗