Biomedical subjects
Publications and source records attributed to Xiaofeng Wang.
A number of aglycon analogues of sarmentosin were prepared and their bioactivities on the proliferation of T-lymphocytes and B-lymphocytes were assayed.
Three heptapeptide toxins, microcystin-RR, microcystin-RY and microcystin-LR, which can cause health problems in animals and humans were monitored in Bang Phra Reservoir, Thailand using reversed-phase high performance liquid chromatography. The concentrations of the three toxins in the reservoir varied greatly depending on location and time water samples were collected. Water quality parameters such as light intensity, temperature, pH, dissolved oxygen, suspended solid, chemical oxygen demand, dissolved organic carbon, total nitrogen, total phosphorus, ammonia, nitrate, phosphate, total dissolved nitrogen, total dissolved phosphorus and chlorophyll-a were also measured in parallel with microcystin determinations. Relationships among water quality parameters, toxins and chlorophyll-a were established. Toxin concentration increased in proportion to increases in total phosphorus, fraction of dissolved phosphorus, but was inversely correlated with water pH and total suspended solids. The other measured parameters in the study showed no correlations to toxin level in reservoir water. Significant correlations between chlorophyll-a and suspended solids, phosphate, nitrate and ammonia were observed suggesting that nitrogen and phosphorus are the two major nutrients governing growth of algae in the reservoir. This relationship suggests that algal production as well as toxin concentration are dependant on nutrient levels in the water body, since both measured light intensity and temperature level was favorable for algal growth. A small algal bloom observed in the rainy season of each year (lasting for only a couple of months) paralleled measured increases in toxin concentration, chlorophyll-a, TP and TN in the water column. Toxin level in the water column remain detectable for 3-4 months period following the initiation of algal bloom. Results indicate that major blooms are likely to occur following the raining season which usually occurs near the end of October when runoff would increase nutrient level entering the reservoir. This study also demonstrated that an ongoing field-monitoring program is needed in these lakes and reservoirs for predicting toxic level of microcystin production for use in risk assessment and for alerting the public to potential health hazards. Concentration of toxin in the reservoir can perhaps be controlled by reducing non point source nutrient input within the watershed.
OBJECTIVE: To analyze the effect of castration on risk factors for arteriosclerosis of patients with prostate cancer. METHODS: Thirty patients with primary regional prostate adenocarcinoma limited to the prostate theca were selected in this study. Serum levels of testosterone (T), free testosterone (FT), dehydroepiandrosterone (DHEA), sex hormone-binding globulin (SHBG), prostatic specific antigen (PSA), triglyceride (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), apoprotein alpha(1) (APOalpha(1)) and apoprotein beta (APObeta), insulin, plasma fibrinopeptide A (FPA), plasminogen activator inhibitor-1 (PAI-1) and fibrinogen were determined just prior to, 1 week and 1, 4 and 8 months after castration. RESULTS: T, FT and PSA decreased significantly 1 week after castration (21.12 +/- 15.11 ng/ml vs 383.9 +/- 62.6 ng/ml, P < 0.001; 4.08 +/- 3.29 pmol/L vs 34.11 +/- 11.59 pmol/L, P < 0.001; 14.34 +/- 7.77 ng/ml vs 23.51 +/- 6.57 ng/ml, P = 0.001, respectively) and continued to decrease until reaching their lowest levels 8 months after castration. DHEA and SHBG did not undergo any changes. TG, fasting insulin and glucose, 2-hour insulin and glucose levels were significantly elevated 1 month after castration (1.84 +/- 0.61 mmol/L vs 1.30 +/- 0.40 mmol/L, P < 0.05; 18.16 +/- 5.57 mU/L vs 9.47 +/- 3.81 mU/L, P < 0.05; 4.77 +/- 0.66 mmol/L vs 3.92 +/- 0.34 mmol/L, P < 0.05; 65.52 +/- 14.78 mU/L vs 36.94 +/- 17.12 mU/L, P < 0.01; 6.98 +/- 0.79 mmol/L vs 6.01 +/- 0.23 mmol/L, P = 0.001, respectively). TC, LDL-C, FPA and PAI-1 levels were elevated 4 months after castration (6.56 +/- 0.99 mmol/L vs 5.29 +/- 0.75 mmol/L, P < 0.01; 4.09 +/- 0.86 mmol/L vs 3.04 +/- 0.15 mmol/L, P < 0.01; 3.39 +/- 1.67 nmol/L vs 1.48 +/- 0.50 nmol/L, P < 0.01; 27.02 +/- 5.98 ng/ml vs 21.78 +/- 3.16 ng/ml, P < 0.05, respectively), continuing to increase after that point. Insulin sensitive index (ISI) decreased significantly 1 month after surgery (-4.42 +/- 0.36 vs -3.50 +/- 0.39, P < 0.001), and continued to decrease from that point forward. HDL-C, APOalpha(1), APObeta and fibrinogen remained at pre-operative levels. There was a negative linear correlation between FT and TG, TC, LDL-C, PAI-1, FPA, fasting insulin and glucose, 2-hour insulin and glucose (r = -0.311, -0.384, -0.385, -0.339, -0.353, -0.381, -0.303, -0.460 and -0.395, respectively; P < 0.05). A similar phenomenon occurred with T (r = -0.308, -0.309, -0.356, -0.320, -0.430, -0.453, -0.435, -0.483 and -0.512, respectively; P < 0.05). T and FT were positively associated with ISI (r = 0.555 and 0.501; P < 0.001). CONCLUSIONS: At 8 months follow-up of the study subjects, we found that lower androgen levels have adverse effects on lipid metabolism, coagulative function and insulin sensitivity, related to arteriosclerosis in men.
OBJECTIVE: To investigate a non-invasive, effective and rapid mode of detecting the recurrence of bladder cancer during follow-up. METHODS: Ninety patients following transurethral resection of bladder tumor (TURBt) surgery were recruited from January 1998 to March 2000. Standard ELISA was used to determine the quantity of nuclear matrix protein (NMP-22) in urine of all bladder cancer patients during their follow-up periods. Urine bladder tumor antigen (BTA) stat test was simultaneously performed and followed by cystoscopy. RESULTS: The total positive rates of urinary NMP-22 and BTA stat test were 76.7% (33/43) and 67.4% (29/43), respectively. Comparatively, this positive rate would increase to 93.0% (40/43) when the combination of both urine NMP-22 and BTA test were adopted. CONCLUSION: Examination of NMP-22 in urine is a rapid and effective way to detect the recurrence of bladder cancer. If combined with BTA test, NMP-22 may be used as a non-invasive method in surveillance of recurring of bladder cancer, which may reduce the frequency of patients needing to undergo conventional invasive cystoscopy.