Biomedical subjects

B Zhang

Publications and source records attributed to B Zhang.

At least 325 records · Page 18Linked to original sources

PubMed1999

[CAG trinucleotide mutation detection in patients with hereditary spinocerebellar ataxia].

OBJECTIVE: To assess the frequency of the SCA1, SCA2,SCA3/MJD, SCA6, SCA7 and DRPLA CAG trinucleotide repeat expansions(CAG)n among individuals diagnosed with hereditary spinocerebellar ataxia(SCA) from Chinese families. METHODS: The SCA1, SCA2, SCA3/MJD, SCA6, SCA7 and DRPLA(CAG)n mutations were detected by polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis and silver staining technique in 167 patients with autosomal dominant SCA from 85 Chinese families and 37 sporadic SCA patients. RESULTS: Among 85 families, four families(4.70%) had seven SCA1 patients with the CAG repeat expanded to 53 to 62 repeats, five (5.88%) had twelve SCA2 patients with the CAG repeat expanded to 43 to 47 repeats, and 41 (48.23%) had 83 SCA3/MJD patients with the CAG repeat expanded to 68 to 83 repeats. Analysis of the mutation in these families showed a strong negative correlation between the size of the expanded CAG repeat and the age of disease onset. None of the SCA patients were positive for SCA6, SCA7, or DRPLA. Nor was any of the sporadic SCA patients positive for the CAG repeat expansion in the SCA1, SCA2, SCA3/MJD, SCA6, SCA7, or DRPLA gene. CONCLUSION: The frequency of SCA3/MJD is substantially higher than that of SCA1 and SCA2 in the autosomal dominant SCA from Chinese families. Chinese SCA3/MJD patients are non-Portuguese. Clinical expressions of the various SCAs overlap one another and hence can make the phenotype-based diagnostic classification inaccurate in many instances. It is important for SCA clinical studies to make an SCA gene diagnosis and genotype analysis.

Adult↗

PubMed1999

[Screening and early diagnosis of primary liver cancer].

OBJECTIVE: To investigate the value of screening for early diagnosis of primary liver cancer (PLC). METHODS: A total of 18,816 persons, who were high-risk population of PLC, were divided randomly to allocated screening group and control group. In the screening group every individual was checked up by serum AFP test and ultrasound every 6 months but those in the control group were not. RESULTS: Eighty-six patients with PLC were detected in the screening group, while 51 patients with PLC occurred in the control group. In patients from the screening group 60.5% were in the early stage, 45.3% of them were with small liver cancer. However, in the control group the figures were 0 and 0 respectively. In the screening group, 57 patients with PLC were detected by follow-up screening every 6 months, 77.2% patients of this series were in the early stage. However in the screening group the other 29 patients with PLC were detected by screening but they were not followed up every 6 months. Early-stage patients were only 27.6% in this series. CONCLUSION: This suggests mass screening, especially continual screening every 6 months in fixed population can diagnose PLC early.

Humans↗

PubMed1999

Construction of high ergosterol-producing yeast strains and study on the optimal conditions for culture.

High ergosterol-producing yeast strains were constructed by primary screening isolation of haploid mutagenesis and protoplasts fusion. The fermentation conditions of fused strain YEF-21 were studied. Under the optimal conditions, i.e., the medium for fermentation consisted of 8% glucose 1% polypeptone 1% yeast extract; initial pH nature; 60 mL broth/250 mL flask; inoculum volume 10%; fermentation time 30 hours at 28 degrees C and 200 r/min; the comprehensive value of biomass and ergosterol content of YEF-21 is 1.54 and 1.55 times that of the parent strains YE227 and YE180, respectively. The fused strain YEF-21 is stable enough genetically according to the analysis of genetic stability, and it is a high ergosterol-producing strain that has prospect for application.

Culture Media↗

PubMed1999

Holistic approach to health education on AIDS.

OBJECTIVE: To identify a method for health education using the example of an educational seminar on AIDS prevention and control at Hebei Medical University in China, 1994. METHODS: Our goal is the theoretical formulation of a unified community approach for problem solving through the combination of the self regulative approach and the case analytical approach. "Quality improvement", "essential quality" and "human ecosystems" provide the basic ideas for better understanding the integration of culture, science and technology within the "cultural norm". RESULTS: The present seminar was successfully organized for Chinese medical students based on the theme of "living with AIDS". Through this program, we identified that self regulative and case analytical approach were major issues for holistic approach to health education. We also identified that a community approach provides the scientific basis for health education in the community. CONCLUSIONS: The present paper generates a healthcare paradigm for surveillance in health/medical education. Through a better understanding of community approach, we related "community care" (emphasizing self, mutual, professional and institutional care) to the "practical norm"; and "preventive epidemiology" (emphasizing the unification of quality and quantity, as well as systems and population) to the "research norm".

Acquired Immunodeficiency Syndrome↗

PubMed1999

[Antisense oligonucleotides inhibit c-myc and PCNA expression in the vascular smooth muscle cells].

OBJECTIVE: To study the methods for prevention and treatment of vascular restenosis. METHODS: We used two factors which result in hyperplasia of vascular smooth muscle cells (VSMCs) and applied antisense c-myc, PCNA oligonucleotides to attenuate the expression of their related gene. The sense, antisense, and mismatched oligomers for c-myc or PCNA were designed and synthesized. They were individually delivered to the cultured VSMCs after the oligomers were stable in culture medium for 5 days and could cross the plasma membranes into the cells. Using RT-PCR and the image analysis system, we observed the changes of both c-myc and PCNA gene expression in the VSMCs. RESULTS: Antisense c-myc and PCNA at a concentration of 10 mumol/L were able to inhibit the expression of c-myc and PCNA gene in VSMCs (P < 0.05), whereas the sense and the mismatched ones couldn't inhibit the expression (P > 0.05). CONCLUSION: The antisense technique is an effective method for the inhibition of VSMCs proliferation.

Animals↗

PubMed1999

[Cisplatin-induced apoptosis in laryngeal squamous cell carcinoma strain and the influence on cell cycle].

OBJECTIVE: To find more effective chemotherapeutic agents and treatment regimens, we studied the cytotoxicity of cisplatin to human laryngeal squamous cell carcinoma strain Hep2. METHODS: Using flow cytometry, fluorescence microscopy, and DNA agarose gel electrophoresis technique, we investigated in vitro Hep2 cells in different conditions. RESULTS: Hep2 was adherent cells in normal survival condition. Cisplatin affected Hep2 cell growth apparently. Under fluorescence microscope, necrotic cells were red, apoptotic cells were blue with condensed and fragmented nuclei, and normal cells were evenly blue. Adherent cells were 86%-96% viable. But nonadherent cells were 6%-13% viable. Death cells increased with the increase of drug concentration and time elapsing. Death cells were mainly apoptotic cells. The latter appeared to be time- and dose-dependent. DNA "ladder" was observed for nonadherent cells in agarose gel electrophoresis, but adherent cells were not. "Sub-G1" phase peak occurred in flow cytometry. After cisplatin treatment, the volume of adherent cells increased with dose- and time dependence. Cisplatin could cause Hep2 cell cycle to change. At first, G1 phase cell percentage reduced, while S phase increased. With time elapsing, G2/M phase increased. Cells experienced a slow-down in S-phase followed by a G2 block. CONCLUSION: Apoptosis is a major way of Hep2 cell death after cisplatin treatment and appeared to be time- and dose-dependent. In clinical chemotherapy, cisplatin should be used in high concentration. Inducing apoptosis is one of the characteristics of chemotherapeutic agents. Cisplatin should be taken a combination regimen with cell cycle-special agents.

Antineoplastic Agents↗

PubMed1999

[Randomized controlled prospective study of secondary prevention for primary liver cancer].

OBJECTIVE: To evaluated the effectiveness of secondary prevention for primary liver cancer (PLC). METHODS: This is a randomized controlled study. 18,816 Shanghai urban residents, aged 35-55, with serum evidence of HBV infection or chronic hepatitis were randomly assigned into the screening group (9,373) or the control group (9,443). In the screening group, participants were tested with serum AFP and real time ultrasound every 6 months, while in the control group, participants were not informed about the study and received no screening. Participants with positive results underwent a diagnostic evaluation, and all patients diagnosed as PLC were treated appropriately and followed up. RESULTS: After 5 years of study, there were 22,631.5 person-years screened. 86 patients with PLC were detected. 51 patients were detected in the control group within 32,944 person-years. In the screened group, 60.5% (52/86) of patients were in stage I, and 45.3% (40/86) with small liver cancer. However, there were no patients in stage I or with small liver cancer in the control group. The resection rates were 46.5% in the screened group, and 7.8% in the control group. The 1 to 5 years survival rates of PLC patients in the screening group were 65.0%, 65.0%, 52.7%, 52.7% and 52.7%, respectively, and in the control group were 30.0%, 6.5%, 0%, 0% and 0%, respectively. CONCLUSION: Screening can detect PLC in the early stage, and improve the prognosis of PLC, indicating that secondary prevention can decrease the mortality of PLC.

Adult↗

PubMed1999

[Diagnosis and treatment of early gastric cancer: an experience from 61 cases].

OBJECTIVE: To review the clinical signs of diagnostic significance and treatment of early gastric cancer. METHODS: Sixty-one gastric cancer patients were collected for this study. They were surgically treated and pathologically confirmed to be in the early stage of disease. The x-ray and gastroscopic findings of these patients were reviewed. RESULTS: Double-contrast barium meal examination was performed in 46 cases and 27 of them were diagnosed as gastric cancer with a detection rate of 58.7%. Superficial type of tumor was easily misdiagnosed as superficial gastritis and concave type of tumor misdiagnosed as benign gastric ulcer under x-ray imaging. All the patients were gastroscopically examined. With examiner's naked eyes, diagnosis of cancer was made in 27 cases (44.3%). Visual diagnosis was difficult when the tumor was small. Attention should be focused on the gastric incisura angularis, antrum and lesser curvature to perform site-directed biopsy. Final diagnosis depended on the pathological diagnosis of the biopsied materials. Pathologic diagnosis would be correct provided the biopsy material was taken from the proper site. It was correct in 58 of the 61 cases (95.1). Surgical treatment consisted of radical gastrectomy and D2 lymph node dissection. All but 2 were tumor free after surgical treatment. Prognosis was good in this series of early gastric cancer patients, 38 of them were alive over 5 years and 12 patients survived over 10 years. CONCLUSION: Careful x-ray and gastroscopic examinations of patients with epigastric symptoms are indicated not to miss any early case of gastric cancer.

Adult↗

PubMed1999

[Antitumor effect of peri-cryosurgical immunotherapy].

OBJECTIVE: To evaluate the anti-tumor effect of combined cryosurgery and immunotherapy in mice. METHODS: C57BL/6 mice bearing B16 melanoma were randomly divided into 3 groups: (1) peri-cryosurgical immunotherapy group, (2) cryosurgery group, (3) immunotherapy group and (4) saline group. RESULTS: The tumor size on day 35 was 0.4 cm3 in group 1, 1.1 in group 2, 1.9 in group 3, and 3.9 in group 4 of mice. The survival period was 71, 62, 53 and 46 days, respectively. None in group 3 and 4 was cured, while 14% of mice in group 2 and 50% in group 1 were tumor tree. In tumor-free mice, no tumor cell in the primary tumor sites was found by light and electron microscopy 3 months later. CONCLUSION: The combined use of cryosurgery and immunotherapy is curative in 50% of mice bearing established B16 melanoma.

Animals↗

PubMed1999

[Effects of tracheal gas insufflation on blood gases and respiratory mechanics in acute hypercapnia rabbits].

OBJECTIVE: To evaluate the effects of tracheal gas insufflation (TGI) on elimination of CO2 and improvement of ventilation efficiency. METHODS: Using self-designed TGI device, physiological parameters such as PaCO2, Ppeak, Ppause, end expiratory carbondioxide pressure (PetCO2), lung statistic compliance(Cst), respiratory resistance(Re) and expiratory lung volume(VE) in the two animal groups of conventional mechanical ventilation (CMV) and hypercapnia (HC) by applying two different TGI flow(0.2 L/min and 0.4 L/min) were observed. RESULTS: TGI can significantly decrease the PaCO2 level, enhance CO2 elimination and maintain PaCO2 in the normal range while decreasing VT by 30%, the eliminating effect of CO2 is flow dependent. TGI can elevate airway pressure in both animal groups, but the level of Ppeak, Ppause in HC group are significantly lower than those of CMV group. PetCO2 levels are significantly decreased after TGI while Re and VE increased significantly after TGI. TGI shows no obvious influence on Cst, mean arterial pressure and heart rate. CONCLUSIONS: Our results reveals that TGI is a simple and practical adjunct method to mechanical ventilation, it can effectively decrease PaCO2, and maintain low airway pressure.

Animals↗

PubMed1999

[A clinical study of mucosa-associated lymphoid tissue lymphoma].

OBJECTIVE: To have a better understanding of the clinical characteristics of mucosa-associated lymphoid tissue (MALT) lymphoma. METHODS: The clinical data of 24 patients with MALT lymphoma were analyzed. RESULTS: The patients were divided into two groups according to the initial location of the lymphoma in the gastrointestinal (GI) tract or not. Eighteen patients (75.0%) had GI involvement and six (25.0%) had involvement of other extranodal sites including salivary gland in three, lung in two and bladder in one. Among the 24 cases, 12 were in stage I, 7 in stage II and 5 in stage III-IV at the time of presentation. Fourteen cases underwent endoscopic biopsy and the pathologic diagnoses were in accordance with those of post-operative specimen in 11 but different in 3. Surgical resection was performed alone in 21 patients, with adjuvant chemotherapy in 7 and with adjuvant radiotherapy in 1. Three patients were treated with chemotherapy only. Results of survival analysis showed that the overall survival rate was 58.8% after 1 year, 35.3% after 3 years, 29.4% after 5 years and 5.9% after 10 years. No significant difference in clinical or biologic characteristics was observed between GI and non-GI patients (P > 0.05). The clinical stage and therapeutic measure had no significant relation with the prognosis. CONCLUSION: MALT lymphoma is an indolent disease that presents in localized extranodal location without any associated adverse prognostic factor in nearly all the patients and that these patients have a high response rate to treatment and a long survival.

Adult↗

PubMed1999

[Low fever of unknown reason in patients undergoing autologous stem cell transplantation after hematopoietic reconstitution: a clinical analysis of 13 cases].

OBJECTIVE: To investigate the reason of low fever in patients undergoing autologous stem cell transplantation after hematopoietic reconstitution. METHODS: The reasons for low fever in 13 patients undergoing autologous stem cell transplantation after hematopoietic reconstitution were comprehensively analyzed. RESULTS: After analysis of clinical features, laboratory tests, imaging and microbiological data, no reason was found for the low fever. There was no effect on the fever with anti-microbial therapy. However the low fever was controlled by low dose prednisone 5-10 mg/d or dexamethasone 2-4 mg. CONCLUSION: The reason for the low fever is not clear; it is probably nonspecific low fever induced by high-dose radiotherapy or high-dose chemotherapy.

Adolescent↗

PubMed1999

[Hepatic resection with removal of tumor thrombi for hepatocellular carcinoma with tumor thrombi in portal vein and curative analysis].

OBJECTIVE: To study the therapeutic effects of surgical treatment for hepatocellular carcinoma (HCC) with tumor thrombi in the main trunk or the first branch of the portal vein (PVTT) and factors affecting prognosis. METHODS: 111 HCC patients with PVTT underwent hepatic resection with removal of tumor thrombi in the first left or the right branch of the portal vein or removal of tumor thrombi by direct opening of the main trunk of the portal vein. Hepatic artery infusion and/or portal vein infusion were performed after hepatic resection with removal of tumor thrombi for HCC with PVTT in 22 of the patients. Among 111 patients, 32 received postoperative transhepatic arterial chemoembolization and/or portal vein chemotherapy. Conservative treatment and surgical exploration or hepatic artery ligation (HAL) and infusion (HAI) and/or portal vein infusion (PVI) were performed in other 14 and 20 HCC patients with PVTT, respectively. RESULTS: The 1-, 2-, 3-, 4- and 5- year survival rates were 61.7%, 36.2%, 32.3%, 24.4% and 22.4% in the resected group, respectively, whereas 14 HCC patients with PVTT treated conservatively died in three months and the 1-, 2- year survival rates were 6.0% and 0 in the 20 patients with surgical exploration or HAL and HAI and/or PVI respectively. CONCLUSIONS: Hepatic resection with removal of tumor thrombi for HCC with PVTT should be encouraged for the prolongation of life span and quality of life.

Adult↗

PubMed1999

[Experimental observation of origins of osteoblasts in guided bone regeneration in long bone].

OBJECTIVE: To study the origins of osteoblasts in guided bone regeneration (GBR) so as to understand the mechanism of GBR. METHODS: New Zealand rabbits were used. Standard ununited defect models were made in bilateral middle radial shaft of each rabbit. Randomly, one defect enveloped with silicon membrane as test, another without membrane as control. 12 rabbits were selected for X-ray examination weekly after procedure. 30 rabbits were divided into 6 groups, and sacrificed at 3 days, 1, 2, 3, 4, 5 weeks after surgery for histological observation by immunohistochemical staining of BMP, BGP. RESULTS: The sealed spaces were made by silicon membranes in the defects to prevent peripheral tissue ingrowing early. The defect spaces were filled by granulation tissue formed from proliferative endoperiosteal and medullary stromal cells in bone end. Histological characteristics after callus forming showed that there were 2 - 3 layers of osteoblasts in the surface of callus, and granulation tissue in the center of bone defect. The transforming region existed between the extending callus and granulation tissue, which consisted of a few of cells and a lot of stroma. Early proliferative endo-periosteal and medullary stromal cells in the bone end were positive against BMP, BGP. Some cells in the transforming region were positive against BMP, BGP after callus forming. CONCLUSIONS: Osteoblasts derive from endoperiosteum and medullary stroma in the early stage of GBR and from granulation tissue formed by proliferative endo-periosteal and medullary stromal cells in the later stage.

Animals↗

PubMed1999

[Direct intramuscular injection of pSV-VEGF(165) augments capillaries formation in a rabbit model of hindlimb ischemia].

OBJECTIVE: To investigate an easier and safer clinical method of gene therapy for treating arterial ischemic diseases in the lower extremity. METHODS: Recombinant plasmid pSV-VEGF(165) constructed in vitro was directly injected into the ischemic hindlimb muscles in rabbit models. 30 days after gene transfer, the capillary density and the capillary to muscle fiber ratio were determined histochemically in the resected samples. RESULTS: The capillary density and the capillary to muscle fiber ratio were significantly higher for pSV-VEGF(165) transfected group than for control group, particularly increased in the shank of the hindlimbs. CONCLUSIONS: Direct intramuscular injection of pSV-VEGF(165) was an easier and efficient gene therapy method, and it significantly augmented the capillary formation in ischemic limbs.

Animals↗

PubMed1999

[Expression of BMP-2, TGF-beta, bFGF in guided bone regeneration].

OBJECTIVE: To study the mechanism of guided bone regeneration combined with osteoinduction by observation of expression of BMP-2, TGF-beta, bFGF. METHODS: 42 adult, male, New Zealand rabbits were randomly divided into 6 groups, each group being 7 rabbits. 10mm standard bone defect model was produced bilaterally in the middle radial shaft of each rabbit. Randomly, one defect enveloped with silicon membrane was tested, and the other served as control, sacrificed at 3 days, 1, 2, 3, 4, 5 weeks after surgery for histological observation, immunohistochemical staining of BMP-2, TGF-beta, bFGF and in situ hybridization of their cDNA probes. RESULTS: Histologically bone defects was sealed by silicon membrane, in which inflammation tissue and callus were formed from cells in bone ends. Similar expression of BMP-2, TGF-beta, bFGF between the test groups and control groups was noted. Inflammatory cells in the hematoma expressed bFGF and proliferating periosteal cells, endosteal cells, medullary mesenchymal cells expressed TGF-beta at 3 days postoperatively. Osteocytes in the bone ends and osteoblasts lining callus surface started to express BMP-2, TGF-beta at first week after surgery. Following the formation of inflammation tissue, in which giant cells, macrophages, mesenchymal cells expressed TGF-beta, bFGF respectively. Although the expression of three osteoinductors was the same between the test and control sides, their content was very different in both sides. The whole content in all test sides was much more than all control sides (P < 0.01), the content of test side was also much more than control side in each group. CONCLUSIONS: It is a key reason for successful guided bone regeneration that membrane tube formed a relatively independent bone regenerative situation to prevent around tissue from interruption, and to prevent osteoinductors from diffusion, so that enhanced osteoinductors induced bone regeneration to repair bone defects.

Animals↗

PubMed1999

[Distribution of genotypes of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 in Japanese twin children].

OBJECTIVE: In order to prevent alcohol related deseases, this study investigated the distribution of the genes controlling alcohol metabolism in Japan's twin. METHODS: Restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) technique was used to measure the control gene of alcohol metabolized enzymes and the genotypes of alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2), which were distributed in Japan's twins. At the same time, according to the difference in genotypes, the sensitive individuals were screened from the study subjects. RESULTS: The distribution of ADH2 and ALDH2 genes were consistent with the Hardy-weinberg equation. The three genotypes of ADH2 gene were ADH2(1)/ADH2(1) (1.1%), ADH2(1)/ADH2(2) (44.6%) and ADH2(2)/ADH2(2) (54.3%). And those of ALDH2 gene were ALDH2(1)/ALDH2(1) (41.3%), ALDH2(1)/ALDH2(2) (39.1%) and ALDH2(2)/ALDH2(2) (19.6%). The frequency of ADH2 and ALDH2 genes was 0.255, 0.745 and 0.609, 0.391 respectively. CONCLUSION: Not only the distribution of genotypes of ADH2 and ALDH2 is known, but also the sensitive individuals are found, which can help prevent alcohol related disease.

Alcohol Dehydrogenase↗

PubMed1999

[Molecular cloning of hTRT catalytic domain and its expression in tumors].

OBJECTIVE: To study the expression of hTRT gene in tumors and its significance in cancer diagnosis. METHODS: The expression of hTRT in HeLa cells and PG cells was estimated by RT-PCR and the hTRT cDNA encoding the catalytic domain from HeLa cells were cloned and sequenced. Using in situ hybridization (ISH) techniques, the expression of hTRT mRNA in 54 human tumors were observed and compared with the expression of hTR. RESULTS: hTRT was detected in both HeLa and PG cells. Sequencing showed that the cloned hTRT catalytic domain cDNA was identical with that reported in the literature. hTRT and hTR expressions were detected in 38/46 and 40/46 malignant tumors respectively, while both hTRT and hTR were not detected in 8 benign tumors. CONCLUSION: hTRT was detected in both HeLa and PG cancer cells. hTRT catalytic domains were highly conservative. The expression of hTRT and hTR were both high in malignant tumors and they were strongly correlated. Our results suggest that detection of hTRT was valuable to clinical oncology diagnosis.

Catalytic Domain↗