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Biomedical subjects

B Zhang

Publications and source records attributed to B Zhang.

At least 235 records · Page 13Linked to original sources
PubMed2000

Oxychlordane and trans-nonachlor in breast adipose tissue and risk of female breast cancer.

BACKGROUND: Organochlorine compounds, including organochlorine pesticides, have been suggested by some, but not all, studies to be associated with female breast-cancer risk. So far, studies relating organochlorine compounds and breast-cancer risk have mainly focused on polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) as risk factors for female breast cancer. This paper examines the hypothesis that environmental exposure to trans-nonachlor (TNC) and oxychlordane (OCD), a major metabolite of the insecticide chlordane, increases the METHODS: A total of 304 histologically confirmed, incident primary breast-cancer patients and 186 histologically confirmed incident benign breast-disease controls were included in the study between 1994 and 1997. Breast adipose tissue not needed for diagnostic purposes was collected and analysed for TNC, OCD and other organochlorine compounds. A standardised, structured questionnaire was used to obtain information on major known, or suspected, risk factors for breast cancer. RESULTS: The age and lipid-adjusted geometric mean adipose-tissue levels of OCD were similar between the cases [36.4 p.p.b., 95% confidence interval (CI) 34.7-38.2 p.p.b.] and controls (38.0 p.p.b., 95% Cl 35.7-40.6 p.p.b.). The age and lipid-adjusted geometric mean adipose-tissue levels of TNC between the cases (55.5 p.p.b., 95% CI 52.6-58.5 p.p.b.) and controls (58.1 p.p.b., 95% CI 54.2-62.3 p.p.b.) were also similar. There was no association between breast-cancer risk and mean adipose-tissue levels of OCD and TNC. The covariate-adjusted odds ratio (OR) was 0.7 (95% CI 0.4-1.3) for OCD and 1.1 (95% CI 0.6-1.9) for TNC, when the highest quartile was compared with the lowest. The risk also did not vary based on oestrogen or progesterone receptor status or menopausal status. DISCUSSION: We found no significantly increased risk of breast cancer associated with breast adipose-tissue levels of OCD or TNC; this is consistent with recent epidemiological studies, indicating that environmental exposure to organochlorine compounds does not have an overall significant impact on breast-cancer risk.

Adipose Tissue↗
PubMed2000

[Studies of the active site, thermostability and thermophilicity of the thermostable alkaline phosphatase by site-directed mutagenesis].

Through PCR-mediated mutagenesis, three mutants E68S, S70A and E68SS70A around active site S(69) were obtained. Their enzymatic characteristics was determined. It was found that the specific activity of E68S ascended 8 times while its optional reactive temperature climbed 20 degrees C and its Tm descended 3 degrees C; the specific activity of S70A ascended 1 time while its optional reactive temperature climbed 5 degrees C and its Tm descended 2 degrees C; the specific activity of E68SS70A descended 50% while its optional reactive temperature climbed 5 degrees C and its Tm descended 19 degrees C. These result implied that the amino acids, beside the active site, were contributed not only to enzymatic activity but also to its thermostability and thermophilicity. The work provided the direction for mutation to improve enzymatic specific activity and studying the mechanism of thermostability and thermophilicity.

Alkaline Phosphatase↗
PubMed2000

[Experimental study on endothelialization of autologous pericardial heart valves in vitro].

OBJECTIVE: To investigate a method of autologous pericardial heart valves (APHV) treatment beneficial to endothelialization. METHODS: Bovine aortic endothelium cells (BAEC) were cultured and seeded in autologous pericardial pieces treated with different methods in vitro. The influence of different treatment on cellular growing, amount of 3H-TdR incorporation and PGI2 releasing, contents of intracellular cAMP was studied by means of transmission electron microscopy, 3H-TdR incorporation experimentation and radioimmunity method. RESULTS: The BAEC seeded in bovine pericardial pieces treated with three different concentrations of GA 10 minutes could alive. In the group with method of treatment with 0.2% GA, the growing of BAEC was best, the cellular density and the amount of 3H-TdR incorporation at different time spots were higher than that of the other groups and it did not enhance the abnormal synthesis of cAMP and PGI2 in BAEC. CONCLUSION: The pericardium treated with 0.2% GA 10 minutes has little toxicity to endothelium cell, which indicates that this method is beneficial to endothelialization of APHV postoperatively.

Animals↗
PubMed2000

[Seroepidemiology of adult diarrhea rotavirus in some countries of Asia].

OBJECTIVE: Adult diarrhea rotavirus (ADRV) is the major cause of severe adult diarrhea. This paper is to survey the ADRV antibody in sera of normal persons of some areas of Asia including China cities of Changchun, Nanking, Taiyuan, Wuhan, Kathmandu of Nepal, Seoul of South Korea and Hong Kong China. METHODS: The ADRV antibody was detected by enzyme-linked immunosorbent blocking test. RESULTS: The data of survey showed that 1. A total detection of 2183 normal sera from persons of Asian areas showed an ADRV antibody positive rate of 3.6% (79/2183); 2. In cities in China and in Hong Kong, the ADRV antibody showed a lower level in age groups of 10-20,20-30-; 3. The ADRV antibody was detectable in normal persons in 1997 in Hong Kong which indicated an earlier existence of ADRV there before the ADRV outbreak in mainland China in 1983; 4. The ADRV antibody level observed in 1986-1991 in Hong Kong showed no obvious difference; 5. ADRV antibody was detectable in normal persons in Nepal and South Korea. CONCLUSIONS: The survey showed there was only a low level of ADRV antibody in normal persons in the Asian areas surveyed.

Adolescent↗
PubMed2000

[Protective effects of gangliosides on cerebral neuronal damage of rat during acute hypoxia].

OBJECTIVE: To observe the preventive and therapeutic effects of gangliosides on acute altitude hypoxic brain damage. METHOD: Fifteen Wistar rats, weighed 180-220 g, were randomly divided into 3 groups, hypoxia group A, hypoxia group B and normoxia group. The rats in hypoxia group A were exposed to a simulated altitude of 7000 m for 5 hours and the rats in hypoxia group B were exposed to hypoxia after intraperitoneal administration of mixed gangliosides (100 mg/kg/d) for 3 days. RESULT: Gangliosides could ameliorate the severity of damage in neuronal bodies, cellular skeletons and synapses, especially in synapses. CONCLUSION: It is suggested that gangliosides are effective in preventing and treating hypoxic brain damages by decreasing the accumulation of intracellular Ca2+, and stabilizing CaM and CaM PKII activity during acute hypoxia.

Altitude Sickness↗
PubMed2000

[Reconstruction of anus in low rectum cancer operation].

OBJECTIVE: While low rectum cancer being resected with Mile's operation, the anus was reconstructed in situ simultaneously. METHODS: Thirty cases of artificial anus were perfectly reconstructed in situ with transferring of the gracilis and invaginating of the end of the sigmoid for the outer and inner sphincter of the anus. The artificial rectum valve was used for the rectum angle. RESULTS: The rate of excellent and good operative results reached 90.63%. CONCLUSION: The results show that this method is suitable for radical operation of low rectum cancer and functional incapacitation of the anus from other diseases as well.

Adenocarcinoma, Mucinous↗
PubMed2000

[Effect of different source iron on piglet's growth, metabolism and environment].

In order to approach the effect of different source Fe on piglet's growth, metabolism and environment, an experiment was conducted with 158 suckling pigs from 15 litters, which were randomly allocated to group I, II and III, and fed with diet I (basal diet + FeSO4.H2O), II (basal diet + Fe-citric acid) and III (basal diet + Fe-methionine complex), respectively. Each of the diets contained 146 mg.kg-1 Fe. The results show that after the experiment ended, the body weight, daily increment, grades for appearance and behavior, hemoglobin concentration in blood, Fe-transferring albumen concentration in plasma, and Fe contents in plasma and liver of 35 days old piglets in group II and III were higher (P < 0.05 or P < 0.01) than those in group I, while the feed conversion, diarrhea incidence, fecal amount and its Fe content of the piglets in group II and III were lower (P < 0.05 or P < 0.01) than those in group I. The body weight and daily gain of the piglets in group III were also higher (P < 0.05) than those in group II, but no significant differences (P > 0.05) in other traits between group II and III. It is suggested that Fe-methionine complex and Fe-citric acid could improve piglet's health, growth and development, feed conversion, and physiological and biochemical parameters, increase the absorption and utilization of Fe by piglet's body, and decrease the fecal amount and its Fe content. Both of them should be effective and safe Fe sources for suckling pigs.

Animals↗
PubMed2000

[Factors affecting colonization of introduced microorganisms on plant roots].

Microorganisms such as biological control agents (BCA), plant growth-promoting rhizobacteria (PGPR) and yield increasing bacteria (YIB) were introduced along growing roots. The colonization process of introduced bacteria was proved that they attached root tipfirst, then distributed along roots, multiplicated there, and survived as certain population size. The colonization location was closely related with root exudates, which was usually at the junction between cortex cells or at the base of lateral roots or root hairs. The variation of colonization by introduced microorganisms in the rhizosphere was caused by biotic and abiotic factors. Biotic factors included the physiological characters of introduced microorganisms and interactions between introduced microorganisms and native microbes. The more important factors were plant genotypes which associated with introduced beneficial microbes and regulated the population and community of those microbes affecting the colonization of introduced microorganisms. Abiotic factors here referred to soil environmental conditions, e.g., soil texture, water content, soil temperature and pH value.

Ecosystem↗
PubMed2000

[Gastric evacuation rate of black sea bream(Sparus macrocephalus)].

The gastric evacuation rate of black sea bream(Sparus macrocephalus) weighing 20-40 g was determined at 18 degrees C in laboratory. Three mathematical models were applied to simulate it. The result indicated that all of these three kinds of models fitted to the experiment data, while statistical analysis showed that the linear model was the best, whether the remained food in stomach was expressed by wet weight or dry weight. When the remained food in stomach was expressed by wet weight, the model was Y = 1.14 - 0.06 t(r2 = 0.82, p < 0.001), and by dry weight, it was Y = 1.36 - 0.07 t(r2 = 0.62, p < 0.001). The gastric evacuation rate of black sea bream was 6-7% of consumed food per hour at 18 degrees C.

Animals↗
PubMed2000

[Assimilation efficiency of pacific oyster Crassortrea gigas].

The effects of body size, food density and its quality on assimilation efficiency of pacific oyster (Crassostrea gigas) were studied under artificial conditions in laboratory. The experimental results show that the filtration and ingestion rates of pacific oyster increased with its body size, which tallied with power function. The assimilation efficiency of pacific oyster was not significantly correlated with its body size, but correlated positively with the organic matter content of food and negatively with food density.

Animal Nutritional Physiological Phenomena↗
PubMed2000

[Treatment of ischemic necrosis of femoral head by focal cleaning and bone graft].

OBJECTIVE: To explore a simple and effective method for the treatment of ischemic necrosis of femoral head. METHODS: The anterior region of hip joint was exposed by anterior hip route, a 1.5 cm x 1.0 cm hole was made at the upper region of the femoral neck just below the head. The necrotic bone and sclerotic bone were completely cleaned by drill and curettage until the fresh cancellous bone was exposed. After irrigation, the bone cavity was filled tightly by iliac bone graft until the collapsed femoral head recovered its normal shape. Traction and continuous passive motion(CPM) were performed at the early stage after operation. RESULTS: Twenty cases with 29 femoral head ischemic necrosis (Marcus III to IV stage) were treated by above methods. After 1 to 3 years follow-up, the results were all satisfactory. The pain disappeared, and the functions of the hip joint were all excellent with almost normal walking and squatting. CONCLUSION: The necrotic bone and the sclerotic bone can be removed by this method, thus optimal conditions for the reconstruction of blood supply is obtained. Abundant cancellous bone graft in the residual bone cavity can support the round shape of the femoral head. CPM is very important in the repair of hyaline cartilage and prevention of joint stiffness. It is a simple and effective method in treating femoral head ischemic necrosis.

Adult↗
PubMed2000

[Clinical significance of sentinel lymph node biopsy in breast cancer].

OBJECTIVE: To study the necessity, feasibility, accuracy and clinical value of sentinel lymph node(SLN) biopsy in the management of breast cancer. METHODS: Technetium-99m labeled colloid particles were injected subcutaneously below the breast tumor before mastectomy. The sentinel lymph nodes identified by lymphoscintigraphy and gamma-counter were dissected out from the excised axillary tissue and separately examined manually for consistency and histologically. RESULTS: In 30 cases studied, SLNs were identified in all but one, with a detection rate of 96.7%. Metastases were detected in SLNS in 8 cases. The other case showed positive axillary lymph nodes but SLN was negative. The sensitivity of SLN biopsy in this study was 88.9%, accuracy was 93.3%, false positive was 0, false negative was 11.1%. CONCLUSION: SLN biopsy, though still under investigation, may in the future substitute routine axillary lymph node dissection in the management of breast cancer.

Adult↗
PubMed2000

[Evaluation of several biological markers in the prognosis of patients with node-negative breast cancer].

OBJECTIVE: To evaluate the practical significance of microvessel count (MVC), c-erbB-2, CD44, cathepsin D and nm23 expression, and clinico-pathological parameters in the prognosis of node-negative breast cancer. METHODS: Sixty two patients with node-negative invasive breast cancer were treated by surgery alone, and followed-up for at least 10 years. Microvessel count (MVC), C-erbB-2, CD44, Cathepsin D and nm23 expression were studied by immunohistochemical technique. With other clinico-pathological parameters, they were evaluated prognostically. RESULTS: Univariate analysis showed that the prognostic factors influencing 10-year overall survival rate were MVC, C-erbB-2, stromal cell cath-D and CD44 expression. Multivariate analysis demonstrated that MVC was the sole independent prognostic factor determining 10-year survival. CONCLUSION: Although MVC, c-erbB-2, stromal cell cath-D and CD44 expression are all of prognostic significance, MVC is most meaningful in evaluating prognosis of node-negative breast cancer patients.

Adult↗
PubMed2000

[Improvement and application of multi-infarct dementia model in rats].

OBJECTIVE: To improve the method of inducing the multi-infarct dementia (MID) model in rats to observe the pharmacodynamic effect of Jiannao Yizhi (JNYZ) granule on MID. METHODS: Retrograde injection with the homologous embolus through the external carotid artery initiated the multi-infarct dementia in rats. The experiment of behavior and morphology were conducted. RESULTS: The extensive and multiple foci of infarction and the obviously declining ability of learning and memory were observed in the model group; the action of JNYZ granule and hydergine could obviously improve them. CONCLUSION: This model is useful to carry out basic research and screen new drugs in treating MID.

Animals↗
PubMed2000

[Treatment of 121 heroin addicts with Han's acupoint nerve stimulator].

OBJECTIVE: To observe the Han's Acupoint Nerve Stimulator (HANS) for the treatment of heroin addicts. METHODS: One hundred and eighty-one cases of heroin addiction with obvious withdrawal syndrome were selected. Among them, 121 cases were randomly assigned to be treated with HANS, and the other 60 cases was taken as the control group. In the HANS group, patients were treated with HANS from the second day of their admission in the treatment center (when the withdrawal symptoms were obvious), they were given 4 treatments (30 min each) a day at the first 3 days, twice a day for 3 more days, and once a day 7 days later. The total treatment lasted 15 days. The acupoints selected were Hegu (LI4) and Laogong (PC 8) on one hand, Neiguan (PC 6) and Waiguan (SJ 5) on the other hand, and Zusanli (ST 36), Sanyinjiao (SP 6) on both legs. The frequency was 2/100 Hz, the intensities of the stimulations were 12-16 mA on arms and 16-26 mA on legs. All the manipulations in the control group were the same as in the HANS group, except that electrodes were placed at the acupoints without any electrical stimulation. RESULTS: There was no significant difference (P < 0.05) on the 8 indices (heart rate, body weight, sleeping time, chilling, pain, anxiety, catarrh and craving) observed between the 2 groups before treatment. After the HANS treatment, all the 8 indices improved significantly as compared with those observed before treatment (P < 0.01), while in the control group only a moderate improvement was observed. CONCLUSION: HANS is obviously effective in relieving the withdrawal syndrome in heroin addicts.

Acupuncture Points↗
PubMed2000

[Prophylaxis against ventilator-induced lung injury by Ambroxol].

OBJECTIVE: To investigate the protective effect of Ambroxol on ventilator induced lung injury (VILI) of rats. METHODS: 30 healthy SD rats were randomly divided into three groups: group A was served as control group (n = 10, V(T) 8 ml/kg), group B received large V(T) ventilation (n = 10, V(T) 40 ml/kg), group C received large V(T) ventilation with pre-treatment of IP ambroxol. The contents of protein, TNF-alpha, IL1-beta, IL-8 in BALF and MDA, SOD, GSH levels in the homogenate of the rat lungs were assayed respectively. Total white blood cells in BALF were counted; The severities of lung injury of the three groups were assessed under a light microscope. RESULTS: The albumin and total protein contents in BALF were significantly higher group A than in groups B and C. A large quantity of WBCs infiltration were found in BALF of group B, while the amount of WBCs were decreased in group C. TNF-alpha, IL-1beta and IL-8 level in BALF of group B were 101.6 pmol.L(-1).mg(-1) Pr +/- 37.4 pmol.L(-1).mg(-1) Pr, 0.47 microgram.L(-1).mg(-1) Pr +/- 0.14 microgram.L(-1).mg(-1) Pr and 2.02 microgram.L(-1).mg(-1) Pr +/- 0.49 microgram.L(-1).mg(-1) Pr, respectively. MDA, one of the parameters reflecting the extent of oxidative reaction, were produced profoundly in the lungs of group B, but the local levels of SOD, which reflects the ability of antioxidation, were decreased significantly in group B. There existed significant differences of the above parameters between group B and group A. Ambroxol could significantly decrease the locally produced TNF-alpha and inhibit the oxidative reactions, and increase the locally antioxidative potency. Severe acute lung injuries were detected in group A by histological examination and the extent of injury was much lighter in group C than in group B. CONCLUSION: Locally increased inflammatory cytokines formation and the imbalanced oxidative/antioxidative reaction play important roles in the pathogenesis of VILI. Ambroxol has an obvious protective effect on VILI through its antioxidant/anti-inflammation potent.

Ambroxol↗
PubMed2000

[Detection of remnants after removal of medullary thyroid carcinoma].

OBJECTIVE: To assess whether calcium stimulation test or somatostain-receptor (SS-R) imaging could early detect remnants after removal of medullary thyroid carcinoma (MTC). METHODS: Calcitonin stimulation (calcium element 3 mg/kg weight, i.v. 10 min), carcino-embryonic antigen (CEA), gastrin (GST) and vasoactive intestinal peptide (VIP) were tested in 14 patients with postoperative MTC. SS-R imaging was used to localize the remnants after removal of MTC in patients with elevated calcitonin. RESULTS: Calcitonin stimulation test showed that the peak value of serum calcitonin was elevated in all patients, of whom 7 had the elevated vatue of basic calcitonin and peak calcitonin. In the 7 patients, SS-R imaging showed normal CEA, GST and VIP. CONCLUSIONS: It is necessary for patients after removal of MTC to perform calcitonin stimulation test for detecting remnants early. SS-R imaging may be useful for localizing remnants and metastatic foci. CEA, GST and VIP are not significant in monitoring MTC after operation.

Adult↗