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Biomedical subjects

B Yang

Publications and source records attributed to B Yang.

At least 415 records · Page 23Linked to original sources
PubMed1991

The relationship between war and homicide rates.

A time-series study from 1933 to 1986 in the USA showed that the nation's military participation rate was concurrently associated with lower homicide rates among nonwhite but not white individuals.

Cross-Sectional Studies↗
PubMed1991

The relationship between divorce, unemployment and female participation in the labour force and suicide rates in Australia and America.

Identical data sets for Australia and the USA from 1946 to 1984 were analysed to explore the association of unemployment rates, female participation in the labour force and divorce with suicide rates. While female participation in the labour force was related to suicide rates in Australia, unemployment was not. For the USA, both female participation in the labour force and unemployment were related to suicide rates.

Australia↗
PubMed1991

[Biological significance of DNA content in parotid carcinoma].

The DNA content was analysed by flow cytometry in 5 samples of normal salivary tissue, 36 cases of benign salivary gland tumors and 50 cases of parotid carcinoma. It was found that the difference in the DNA index (DI) and proliferative index (PI) in age, sex, tumor size and TNM staging were insignificant (P greater than 0.05). The DI and PI of poorly differentiated parotid carcinoma were much higher than those of well differentiated parotid carcinoma (P less than 0.05). The DI and PI were closely related to the presence of lymph node metastasis (P less than 0.001). The DI and PI of patients with facial nerve paralysis and with disease free period shorter than 5 years were remarkably higher than those with normal facial nerve and disease free survival for more than 5 years (P less than 0.01). The above results indicate that DI and PI, showing cell proliferative kinetic characteristics, can provide reliable and objective parameters for assessing the degree of differentiation, degree of malignancy, biological behavior and prognosis of parotid carcinomas.

Adenoma, Pleomorphic↗
PubMed1991

[Plasma PGI2 and TXA2 levels on a model of PDH in leptospirosis].

Guinea pigs were intravenously injected with icterhemorrhagiae serogroup Lai serovar strain 017 leptospirosis to model the pulmonary diffuse hemorrhage (PDH) in leptospirosis. Thirty-eight hours after the injection, the jugular arteries were catheterized to collect blood sample. The plasma was prepared for radioimmunoassay of TXB2 and 6-keto-PGF1a, the stable metabolites of TXA2 and PGI2 respectively. The plasma level of TXB2 in the experimental group, 107.15 +/- 41.65 pg/ml (n = 7), almost doubled that of the control, 54.05 +/- 12.93 pg/ml (n = 7), with significant difference (P less than 0.01); meanwhile, no significant difference was observed of 6-keto-PGF1a, 67.97 +/- 16.89 pg/ml (n = 6) vs. 98.06 +/- 40.63 pg/ml (n = 9) with P greater than 0.1. The fact that TXA2 causes vasoconstriction and increases vessel permeability suggests that TXA2 elevation should play a role in the mechanism of PDH in leptospirosis.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

[Pharmacokinetics of four benzimidazoles administered intragastrically to mice infected with secondary cysts of Echinococcus granulosus].

Mice infected with secondary cysts of Echinococcus granulosus were treated ig with mebendazole (Meb), albendazole (Alb), albendazole sulfoxide (AlbSO) or albendazole sulphone (AlbSP) at equal effective dosage. The blood concentrations-time courses of the four drugs were adequately fitted to a liner one-compartment open model analysed with a modified NONLIN program, and the major pharmaco- kinetic parameters were then calculated (Table 1). When Alb was given ig to the infected mice, 76.2-84.5% of the drug absorbed was metabolized to AlbSO. There fore, the pharmacokinetics of AlbSO in Alb group was determined. After ig administration of Meb to the infected mice, the ratio of the drug contents in cyst wall to corresponding plasma concentrations of Meb was 10.6-26.9%, but much less in cyst fluid. In Alb and AlbSO groups, similar AlbSO contents in cyst wall and cyst fluid with higher ratio to plasma concentrations were observed (Fig 3). The results suggest that E granulosus cysts were more susceptible to Meb than to Alb or AlbSO, and improvement of Meb absorption would be favourable for enhancement of efficacy in the treatment of hydatid disease.

Albendazole↗
PubMed1991

[Toxic principles of Oxytropis glabra DC].

Eight alkaloids were isolated from Oxytropis glabra and identified as anagirine, thermopsine, N-methylcytisine, sparteine, baptifoline, adenine, dictamnine and ethyl allophanate respectively by spectral analysis and physicochemical methods. All these alkaloids were isolated from this genus for the first time and ethyl allophanate was found in nature for the first time.

Alkaloids↗
PubMed1991

[In vitro cultivation of the exoerythrocytic stage of Plasmodium berghei].

This paper reports on an in vitro culture system for the exoerythrocytic (EE) stage of Plasmodium berghei (P.b.) using embryonic lung cells. The system was first developed by our laboratory in China. The embryonic lung cells were isolated by trypsin digestion of a human embryonic lung obtained from a therapeutic abortion case and was designated as cell line Elu 8801. Anopheles stephensi mosquitoes were infected by biting P.b. ANKA strain infected Kunming mice and after 18-21 days were dissected under aseptic conditions for preparation of a sporozoite suspension. This suspension was used to inoculate the monolayer cultures of Elu 8801. Regular examination found that following a cultivation for 48 hours, up to 100 multinuclear EE schizonts of P.b. could be observed on 1 x 1 cm cover slide. Seventy-two hours later mature merozoites were seen among part of the schizonts. An intraperitoneal inoculation of the supernatant culture medium to mice could induce malaria infection which could be transferred to other mice by blood inoculation. When the mice infected with the second generation were allowed to feed A. stephensi, sporozoites developed in the mosquitoes. The results demonstrate that the human embryonic lung cell line Elu 8801 established in our laboratory is susceptible to P.b. ANKA sporozoites and can support the developmental maturation of EE stages, producing potentially infectious merozoites.

Animals↗
PubMed1990

A study on the inhibition of rat myocardium glutathione peroxidase and glutathione reductase by moniliformin.

In preparations of Wistar rat myocardium, Km values of GSH-Px to the substrates, H2O2 and GSH, as determined by the DTNB method, were 1.9 x 10(-4) mol/L and 2.0 x 10(-3) mol/L respectively. The Km value of GSSG-R to GSSG was 6.0 x 10(-5) mol/L by UV spectrophotometric assay. In vitro, the activity of GSH-Px was inhibited by 1.0, 6.0 and 16.0 mmol/L synthetic moniliformin (MF) with the corresponding activities of 89.4%, 65.2% and 47.9% of control values (n = 6). The activities of GSSG-R in the presence of 16.0 and 32.0 mmol/L MF were 74.4% and 61.9% of controls (n = 5) respectively. These results revealed that the inhibition of GSH-Px by MF was stronger than that of GSSG-R. As determined by Lineweaver-Burk and of Dixon plots, the inhibition of GSH-Px and GSSG-R by MF was competitive and noncompetitive, respectively. The affinity of GSH-Px to MF was higher than that of GSSG-R because the inhibition constant Ki of the former (6.0 mmol/L) was less than that of the latter (39 mmol/L). We suggest that the mechanism of toxic-damaging effects of MF on myocardium, may be closely related to the failure of remove of free radicals by some enzymes, as GSH-Px and GSSG-R, and that MF may be involved in keshan disease.

Animals↗
PubMed1990

Time-series analyses of the American suicide rate.

A time-series study of suicide in the USA from 1940 to 1984 explored the extent to which social and economic variables could predict the actual suicide rate, the smoothed trend in the suicide rate, and deviations of the actual suicide rate from the smoothed trend. It was found that the social and economic variables were more successful in predicting the smoothed trend in the suicide rate.

Cross-Sectional Studies↗
PubMed1990

[Reconstitution of rabbit brain GABA binding protein (receptor) on Xenopus oocytes].

Gurdon's Xenopus laevis oocyte translation system has been extensively employed to investigate the molecular biology of gamma-aminobutyric acid (GABA) receptors in the brains of embryonic chick, rat, etc. As GABA and its receptor may play a role in the pathogenesis of hepatic encephalopathy and a rabbit model of fulminant hepatitis has been established, we reconstituted the rabbit model of fulminant hepatitis has been established, we reconstituted the rabbit brain GABA binding protein (receptor) on Xenopus laevis oocytes to offer a base for further study of the pathological effects of GABA receptor at molecular level. In this report, total RNA was extracted from rabbit brain by guanidine hydrochloride method. The total RNA was then subjected to oligo-(dT)-cellulose affinity chromatography to isolate mRNA. All the RNA samples achieved a high purity with an average OD260/OD280 ratio of about 2.10. The clear bands of 18 S and 28S rRNA in electrophoresis implied that the RNA was not degraded and was therefore available for expression. After two days of incubation of the oocytes injected with mRNA, radioreceptor assay indicated that saturable and specifically displaceable GABA binding sites were implanted onto the oocyte membrane. This result led us to the conclusion that rabbit brain GABA binding protein (receptor) can be reconstituted by injecting exogenous mRNA inclusive of those encoding the receptor into Xenopus oocytes. However, the functional activity of the reconstituted receptor as a GABA gated chloride ion channel needs to be further characterized by patch clamping.

Animals↗