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Biomedical subjects

B Wang

Publications and source records attributed to B Wang.

917 records · Page 51Linked to original sources
PubMedDate not supplied

Solar ultraviolet radiation and skin damage: an epidemiological study among a Chinese population.

To explore skin damage resulting from solar ultraviolet radiation on Mongoloid people, we investigated 470 healthy people in northeast China. We assessed their skin texture and elastic fibers, number of Langerhans cells, and the incidence of p53 gene mutations. The results showed that solar ultraviolet radiation played a significant role in aging of skin in Chinese people; aging began at 30 y of age (i.e., 20 y later than in Caucasians). In the high-exposure group, aging of skin was twice as severe and occurred 10 y earlier than in the low-exposure group. The counts of Langerhans cells had a tendency to decrease in the high-exposure group. Neither p53 mutations nor solar keratosis were found in individuals of any age-findings that indicated a qualitative different pattern than that of Caucasians.

Adolescent↗
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Clinical engineering & equipment policy for Sao Paulo State, Brazil.

A comprehensive equipment policy was established for the health system of Sao Paulo State, Brazil. Research, development and regulation issues were integrated with all phases of the equipment life cycle, including: planning, procurement, acceptance testing, commissioning, maintenance, repair, refitting, and decommissioning. This policy was implemented by a multidisciplinary group, which advised and coordinated planning and procurement, created a technology management and maintenance network composed of clinical engineering teams and reference centers, and worked closely with manufacturers, universities and research institutes to improve the quality and increase the variety of domestic medical products in order to substitute for imported devices.

Brazil↗
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Arsenic trioxide induces apoptosis in cisplatin-sensitive and -resistant ovarian cancer cell lines.

Arsenic trioxide (As(2)O(3)), has been used for centuries in traditional Chinese medicine; it has considerable efficacy in the treatment of relapsed acute promyelocytic leukemia, inducing partial differentiation and promoting apoptosis of malignant promyelocytes. Although a number of studies have demonstrated that As(2)O(3) has potent activity against cell growth in a series of leukemia cell lines, little information is available regarding this compound's effect on cell growth in solid tumor cell lines. In this study, we investigated the effects of As(2)O(3)in vitro on ovarian cancer cell lines sensitive (3AO) and resistant (3AO/CDDP) to cisplatin. The 3-(4,5-dimethy-thiazoyl-2-yl)-2,5-diphenyl-tetrazolium bromide assay was used to evaluate cytotoxicity. Flow cytometric analysis was used to determine the apoptosis, cell cycle distribution. We clearly demonstrated that As(2)O(3) induced cell apoptosis and inhibition of cell growth in both the cell lines. Furthermore, we identified that As(2)O(3)-induced apoptosis involved Fas pathway. As(2)O(3) is an active agent against ovarian cancer cells and could be effective in the clinical treatment of ovarian cancer.

Apoptosis↗
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Inhibition of nuclear factor-kappaB by an antioxidant enhances paclitaxel sensitivity in ovarian carcinoma cell line.

The objective of this study was to determine whether paclitaxel and a strong antioxidant, pyrrolidinedithiocarbamate (PDTC), can affect the activation of nuclear factor-kappa B (NF-kappaB) in SKOV-3 human ovarian cancer cell line and the effect of these two agents on the growth and apoptosis of the cancer cells. The cells were treated with various concentrations of paclitaxel and/or PDTC at various time intervals. Following treatments, cell growth and apoptosis were determined by 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphonyl)-2H-tetrazolium (WST-8) (WST) assay and flow cytometry, respectively. Western blot assay was used to determine the nuclear p65 protein and cytoplasmic IkappaB-alpha protein. High doses of PDTC significantly inhibited the growth of SKOV-3 cells and caused apoptosis. Paclitaxel and lower doses of PDTC combined demonstrated additive inhibition of cell growth and increased levels of apoptosis. Treatment of paclitaxel alone showed increased nuclear p65 protein and decreased cytoplasmic IkappaB-alpha protein expression, while pretreatment of PDTC reversed this function. PDTC blocks the paclitaxel-induced activation of NF-kappaB leading to increased chemosensitivity to paclitaxel and enhanced apoptosis. Combining antioxidants and paclitaxel has significant potential to overcome the risk of paclitaxel resistance.

Antineoplastic Agents, Phytogenic↗
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Safety and immunogenicity of intramuscular and intravaginal delivery of HIV-1 DNA constructs to infant chimpanzees.

Any global strategy for controlling the human immunodeficiency virus (HIV) epidemic is likely to rely heavily on immunization of infants and children. Given the well-documented differences in children's responses to traditional vaccines, we initiated this study to extend our findings on DNA vaccination of adult chimpanzees to immunologically immature infant chimpanzees. Our findings were consistent with our previous work in adults as we observed that the DNA vaccines used here were both well tolerated and immunogenic within weeks of the initial vaccination.

AIDS Vaccines↗
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beta(2)-adrenergic receptor overexpression exacerbates development of heart failure after aortic stenosis.

BACKGROUND: Beta-adrenergic signaling is downregulated in the failing heart, and the significance of such change remains unclear. METHODS AND RESULTS: To address the role of beta-adrenergic dysfunction in heart failure (HF), aortic stenosis (AS) was induced in wild-type (WT) and transgenic (TG) mice with cardiac targeted overexpression of beta(2)-adrenergic receptors (ARs), and animals were studied 9 weeks later. The extents of increase in systolic arterial pressure (P<0.01 versus controls), left ventricular (LV) hypertrophy (TG, 94+/-6 to 175+/-7 mg; WT, 110+/-6 to 168+/-10 mg; both P<0.01), and expression of ANP mRNA were similar between TG and WT mice with AS. TG mice had higher incidences of premature death and critical illness due to heart failure (75% versus 23%), pleural effusion (81% versus 45%), and left atrial thrombosis (81% versus 36%, all P<0.05). A more extensive focal fibrosis was found in the hypertrophied LV of TG mice (P<0.05). These findings indicate a more severe LV dysfunction in TG mice. In sham-operated mice, LV dP/dt(max) and heart rate were markedly higher in TG than WT mice (both P<0.01). dP/dt(max) was lower in both AS groups than in sham-operated controls, and this tended to be more pronounced in TG than WT mice (-32+/-5% versus -16+/-6%, P=0.059), although dP/dt(max) remained higher in TG than WT groups (P<0.05). CONCLUSIONS: Elevated cardiac beta-adrenergic activity by beta(2)-AR overexpression leads to functional deterioration after pressure overload.

Animals↗
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Indoor air pollution and respiratory health in urban and rural China.

During the summer of 1999, information about respiratory health outcomes and relevant covariates was collected from 3,709 Chinese adults in Beijing, Anqing City, and rural communities in Anqing Prefecture. Indoor PM10 and SO2 were measured in a random sample of selected households. Using logistic regression and controlling for important covariates (excluding PM10 and SO2) and familial intraclass correlation, highly significant differences were found between study areas in the prevalences of chronic cough, chronic phlegm, wheeze, and shortness of breath, but not physician-diagnosed asthma. Generally, the lowest prevalence of respiratory symptoms was observed in Anqing City, a higher prevalence in rural Anqing, and the highest prevalence in Beijing. Median indoor concentrations of PM10 were similar in Anqing City (239 microg/m3) and rural Anqing (248 microg/m3), but much higher in Beijing (557 microg/m3). Median indoor concentrations of SO2 were similar in all three areas (Beijing: 14 microg/m3, Anqing City: 25 microg/m3, rural Anqing: 20 microg/m3).

Adult↗
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Particulate matter, sulfur dioxide, and pulmonary function in never-smoking adults in Chongqing, China.

Chongquing is one of the most polluted cities in China. To study the respiratory health effects of air pollution for this city, the authors monitored the ambient levels of particulate matter (PM2.5) and sulfur dioxide (SO2) in urban and suburban areas and performed pulmonary function testing on 1,075 adults 35 to 60 years of age who had never smoked and did not use coal stoves for cooking or heating. The mean concentration of SO2 in the urban areas (213 micrograms/m3) was twice as high as that in suburban areas (103 micrograms/m3). Mean PM2.5 levels were high in both urban (143 micrograms/m3) and suburban (139 micrograms/m3) areas. A generalized additive model was used to estimate the differences between the two areas in FEV1, FVC, and FEV1/FVC%, with adjustment for potential confounding factors, including sex, age, height, education, passive smoking, and occupational exposures to dust, gas, or fumes. Estimated differences in FEV1 between the urban and suburban areas were 199 mL (SE = 50 mL) for men and 87 mL (SE = 30 mL) for women, both statistically significant. When the men and women were pooled, the estimated difference in FEV1 was 126 mL (SE = 27 mL). Similar trends were observed for FVC and FEV1/FVC%. After exclusion of 104 subjects with histories of occupational exposures to dust, gas, or fumes, the estimated difference was some-what smaller than that of the total samples. However, the effects on FEV1 and FEV1/FVC% remained significant for both men and women.

Adult↗
PubMedDate not supplied

CYP2C9 Ile359Leu polymorphism, plasma irbesartan concentration and acute blood pressure reductions in response to irbesartan treatment in Chinese hypertensive patients.

Our previous study demonstrated that the CYP2C9*3 gene variant was significantly associated with elevated plasma irbesartan concentration and blood pressure decline, assessed by a 4-week follow-up and revisit following daily administration of irbesartan. We conducted a further analysis to examine the acute effects of the CYP2C9 polymorphism on plasma concentration and blood pressure through remeasurement 6 h after administration of irbesartan. We used an extreme-sampling approach by selecting individuals from the top and bottom deciles of blood pressure response residuals to irbesartan from the previous study population in Anhui, Taihu, and Dongzhi Counties, in China. A total of 196 subjects were available for the analysis. Pre- and posttreatment systolic and diastolic blood pressures (SBP and DBP), and venous blood samples (0.5, 2, and 6 h following the first treatment) were collected from each individual. Plasma irbesartan concentrations were determined by a standard HPLC/fluorescence method. The observed frequencies were 97.7% for CYP2C9*1 (Ile359) and 2.3% for CYP2C9*3 (Leu359). Subjects with the CYP2C9*1/CYP2C9*3 genotype had significantly higher plasma irbesartan concentrations when compared with those with the CYP2C9*1/CYP2C9*1 genotype (beta +/- SE = 81 +/- 36) and greater DBP response (beta +/- SE = 5.6 +/- 2.5 mmHg) at the 6-h time point after adjusting for important confounders. Our finding suggests that the CYP2C9*3 gene variant significantly alters the plasma concentration and acute DBP response at the 6-h point following irbesartan treatment in Chinese hypertensive patients.

Administration, Oral↗
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Gold sodium thiomalate suppresses the differentiation and function of human dendritic cells from peripheral blood monocytes.

OBJECTIVE: Gold sodium thiomalate (GST) is a drug commonly used for the treatment of rheumatoid arthritis (RA). To clarify the mechanism of therapeutic effects of GST on RA, we investigated if GST affects the differentiation of dendritic cells (DC), which are thought to play a pivotal role in RA pathogenesis. METHODS: We generated immature DC (iDC) in vitro from PB monocytes during the 5 to 7-day culture in the presence of IL-4 and GM-CSF. Mature DC (mDC) were induced by adding TNF alpha on day 5 of the 7-day culture with GM-CSF and IL-4. DC capacity of stimulating T cells was examined in allogenic MLR using generated DC as stimulators. IL-12 production from DC was assayed with ELISA. RESULTS: We found that: 1) mDC generated in the presence of GST showed lower expression of CD1a, CD83, CD80, CD86, HLA-ABC and HLA-DR compared to control mDC on FACS analysis. 2) GST-treated mDC showed reduced capacity of stimulating allogenic T cells in mixed leukocyte reaction. 3) IL-12p70 production after stimulation with SAC or LPS plus IFN gamma was markedly reduced in GST-treated mDC. CONCLUSION: GST suppresses the differentiation and function of DC generated from peripheral blood monocytes. This previously unknown action may explain the in vivo effects of GST in the treatment of RA.

Antirheumatic Agents↗
PubMedDate not supplied

Dysbaric osteonecrosis by X-ray and CT scan in Chinese divers.

OBJECTIVE: To compare the results of X-ray and CT scan for dysbaric osteonecrosis in Chinese divers. METHODS: Both shoulders, hips and knees of 66 asymptomatic divers with diving duration of more than one year were examined by X-ray and CT scan. RESULTS: The most frequent locations of dysbaric osteonecrosis were the upper femurs, followed by the upper humerus, lower femurs and upper tibias, and the most frequent radiographic lesions were calcification spots and cystic changes. Of the lesions detected, 38% (27/71) and 42% (95/229) werejuxta-articular of the femoral and humeral heads by X-ray and CT respectively. The detection rates of dysbaric necrosis (juxta- and/or other lesions) of X-ray and CT scan were 42.4% (95% confidence interval: 30.5%-54.3%) and 81.8% (95% CI: 72.4%-91.2%) respectively (p<0.05). If CT scan was used as the gold standard, the sensitivity of X-ray was 100% and the specificity was 31.6%. CONCLUSION: CT scan showed a higher detection rate of dysbaric necrosis than X-ray. We recommend that CT scan be used for early diagnosis of dysbaric osteonecrosis.

Adult↗
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Treatment of urgency and urge incontinence with flavoxate in the People's Republic of China.

Flavoxate is a smooth muscle relaxant widely used to treat urgency and urge incontinence. It has been used in an unblinded, uncontrolled clinical trial in 14 urology departments in universities and major hospitals in the People's Republic of China involving 361 patients with urgency/incontinence of various types. Patients were given 200 mg three times daily, orally, for 2 weeks, although 33 patients received a daily dosage of 1200 mg. Frequency, urgency, dysuria, nocturia and incontinence were assessed and scored clinically prior to and after treatment. Three departments also included urodynamic investigations, e.g. monitoring of the end-residual volume. Results from 336 evaluable patients indicate that 228 (67%) were completely cured of urgency/incontinence symptoms, 66 (20%) were improved and 42 (13%) patients were unchanged. Flavoxate was also effective in 77.4% of patients refractory to previous anti-cholinergic treatment. Treatment did not increase the end-residual volume and adverse events occurred only in four (1.3%) patients, two (0.6%) of which discontinued the therapy. The 1200 mg dose produced a complete cure in 82% of patients and improvement in the remaining 18%, with no side-effects. In conclusion, flavoxate is an effective and well tolerated treatment for urgency/incontinence of various causes.

Adolescent↗
PubMedDate not supplied

A fetal alcohol syndrome surveillance pilot project in American Indian communities in the Northern Plains.

A pilot fetal alcohol syndrome (FAS) surveillance was carried out in four American Indian communities in the Northern Plains by the Aberdeen Area Indian Health Service to determine the incidence of FAS and to evaluate the feasibility of establishing continuing surveillance for FAS. Baseline data on the incidence of FAS would be used by the Indian Health Service to develop and evaluate preventive interventions, including treatment programs for pregnant women who drink alcohol. Four of the 1,022 children included in the project were found to have FAS, a rate of 3.9 per 1,000 live births. The rate is believed to underestimate the true rate of FAS because some low birth weight children were not screened, parents or guardians were reluctant to bring children suspected of FAS for evaluation, clinicians were hesitant to diagnose possible alcohol-damaged children for fear of labeling the child, and some children with FAS died before the diagnosis of FAS could be confirmed. If the rate of FAS is similar for the 39 percent of the infants not screened and for the 25 percent of suspected infants who were not evaluated, a rate of 8.5 cases of FAS per 1,000 live births may be postulated. The authors recommend routine screening of prenatal patients for substance abuse and establishing a tracking system for low birth weight infants suspected to have FAS or other alcohol-related developmental disorders, in an effort to establish more accurate FAS rates. Such a surveillance system would identify women at risk of having alcohol-affected infants so that appropriate treatment and counseling could be provided, possibly reducing the severity of adverse effects of alcohol on their fetuses.

Fetal Alcohol Spectrum Disorders↗
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Activated c-Ha-ras is not sufficient to produce the preneoplastic phenotype of human breast cell line MCF10AT.

MCF10AT cells are human breast epithelial cells which are able to establish preneoplastic lesions in immune deficient mice. Although, the preneoplastic phenotype was observed following transfection with a mutated c-Ha-ras (codon 12 valine), clones of MCF10AT are unable to form lesions in vivo. Restriction size fragment analysis was used to confirm that a clone unable to form the preneoplastic lesions retained the activated c-HA-ras and confirmed that the insertion site of the activated c-Ha-ras was the same for the clone as for MCF10AT1 which was selected for its ability to form lesions in vivo. Western blotting with antibody specific for the codon 12 valine c-Ha-ras demonstrated that p21 protein was comparable as well. Thus, the activated c-Ha-ras is not sufficient for the preneoplastic phenotype of human breast stem cell line MCF10AT.

Animals↗
PubMedDate not supplied

Transforming and oncogenic potential of activated c-Ha-ras in three immortalized human breast epithelial cell lines.

The ability of activated c-Ha-ras (codon 12 valine) to transform human breast epithelial cells varied for three different immortalized normal human breast epithelial cell lines established from two different women. Although activated c-Ha-ras may transform and induce a preneoplastic phenotype in MCF10A cells, activated c-Ha-ras was not sufficient to transform MCF10-2A cells. Only two of three MCF10-2A clones which expressed mutant p21 protein acquired the ability to form colonies in soft agar. When xenografted into nude beige mice, two MCF10-2A clones formed squamous carcinomas and one formed no lesions at all. The ability to form tumors did not correlate with growth in soft agar. All three activated c-Ha-ras-transfected clones of MCF-12A formed colonies in soft agar but only two produced squamous carcinomas in nude beige mice. Unlike activated c-Ha-ras-transfected MCF10A cells, none of the activated c-Ha-ras-transfected MCF10-2A or MCF-12A clones formed ducts in xenografts. Rather, initial xenograft lesions consisted of nests of cells with squamous differentiation. These observations illustrate that additional events are involved in the transformation and progression of human breast epithelial cells with activated c-Ha-ras.

Animals↗