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Biomedical subjects

Y Zeng

Publications and source records attributed to Y Zeng.

At least 199 records · Page 11Linked to original sources
PubMed1994

An examination of reforms on the social security system of retirement based on practices in Hainan province.

"The first task of this article is to analyze and dissect the seven major drawbacks of the current disjointed retirement system [in China] characterized by collection of pension for immediate distribution. This will be followed by an introduction of the reforms on the social security system of elderly support for enterprise retirees carried out in Hainan Province and specific social security and elderly support practices by private businesses in Haikou, capital city of Hainan Province....Special inquiries are made regarding the necessity and feasibility of establishing a national uniform social security system of elderly support covering civil servants, enterprise workers, private business owners, managers, and employees and farmers."

Asia↗
PubMed1994

Establishment of a human malignant T lymphoma cell line carrying retrovirus-like particles with RT activity.

We have established an IL-2 independent malignant lymphoma line (CM-1) from peripheral T lymphocytes donated by a female patient with nervous system disease, the biological characteristics of CM-1 cells was studied in this paper. Another T lymphocytes, such as peripheral T lymphocytes donated by a male patient with multiple sclerosis, could be transformed into a malignant lymphoma line by using filtered supernatant of the CM-1 cultured medium, thus the CM-2 cell line was established. The CM-1 and CM-2 cells were transplanted by subcutaneous inoculation into nude mice, and could cause the occurrence of typical malignant lymphoma. The observation of electron micrographs suggested the existence of virions in the CM-1 and CM-2 cells, and these virions were similar to retrovirus in the ultra-structure characteristics. It was found that this virus possesses reverse transcriptase activity. Results obtained from serological assay, molecular hybridization and PCR excluded the existence of other human viruses, which were commonly used in our laboratory. The unknown virus possesses strong transformation activity, and probably is a new retrovirus. Meanwhile, the work on the clone and sequence analysis of this virus are being carried out.

Adult↗
PubMed1994

[Laboratory research of biomechanics assay of skin wound healing].

The study described skin wound healing process in mice in the field of biomechanics by assaying the wound breaking strength (WBS) at different time with the INSTRON 4300 Materials Tester (England). The result revealed there was no significant change of WBS on the 3rd and 4th days. From the 5th to 21st day the WBS increased rapidly. From the 21st to 28th day the increased of WBC became slow and after the 28th day WBS tended to be stable. By the day of seven, the healing wound strength was 14% of normal skin and by the day of 28 the strength was 80%. Histopathologic appearance manifested a gradual change process of wound from inflammation to fibril healing. By this we divided the wound healing process into three periods: adhesion period (1st to 4th day), fibril healing period (5th to 28th day) and fibril reconstructive period (after the 28th day). The study provided a clinical reference for the best times of removing sutures and taking functional exercise after an operation.

Animals↗
PubMed1994

[The case-control study of hepatitis risk factors in Shashi City].

Hepatitis was regarded as a main health problem in Shashi city, Hubei province, according to DSP data at present. The case-control study of hepatitis risk factors were carried out among 115 hepatitis cases and 60 controls that all were negative serologically in Shashi city. The result indicates that economic status, way of having breakfast outside, habits of washing hands before meals and after feces, levels of knowing about route of infection of hepatitis are independently associated with morbidity probability of hepatitis A, the comprehensive preventive measures are presented in the light of these conclusions.

Case-Control Studies↗
PubMed1994

Screening of Epstein-Barr virus early antigen expression inducers from Chinese medicinal herbs and plants.

Ether extracts of 1693 Chinese medicinal herbs and plants from 268 families were studied for the induction of Epstein-Barr viral (EBV) early antigen (EA) expression in the Raji cell line. Fifty-two from 18 families were found to have inducing activity. Twenty-five and seven of them were from Euphorbiaceae and Thymelaeaeeae, respectively. Some of them, such as Croton tiglium, Euphorbia kansui, Daphne genkwa, Wikstroemia chamaedaphne, Wikstroemia indica, Prunus mandshurica Koehne and Achyranthes bidentata are commonly used drugs. The significance of these herbs in the activation of EBV in vivo and their relation to the development of nasopharyngeal carcinoma were discussed.

Antigens, Viral↗
PubMed1993

Biosynthesis of glucosidase II in suspension-cultured soybean cells.

Since antibody against homogeneous mung bean glucosidase II cross-reacted with a 110-kDa protein from cultured soybean cells and also precipitated this activity from extracts of soybean cells, we used this antibody to examine the biosynthesis, turnover, and cellular localization of glucosidase II in soybean cells. Time course studies of [35S]methionine incorporation into glucosidase II (as well as pulse-chase studies) showed that this enzyme is synthesized as a 110-kDa protein that does not change in size from very early labeling times to those as late as 60 h, indicating the absence of a cleavable signal sequence or extensive modification of the carbohydrate. Furthermore, glucosidase II remained susceptible to digestion by endo-beta-N-acetylglucosaminidase H throughout this time period, and the major oligosaccharide structure was a Man9(GlcNAc)2 with small amounts of Glc1Man9(GlcNAc)2. The half-life of the biosynthesized glucosidase II was about 36 h, and no secretion of this protein occurred. Membranes of gently disrupted cells were separated by sucrose-density gradient centrifugation, and fractions were tested for glucosidase II activity as well as for marker enzymes. The bulk of the glucosidase II activity fractionated with endoplasmic reticulum membranes. Detergent solubility studies with Triton X-114 suggested that glucosidase II did not have a hydrophobic domain and is probably a luminal endoplasmic reticulum protein.

Autoradiography↗
PubMed1993

A molecular inventory of human pancreatic islets: sequence analysis of 1000 cDNA clones.

The islets of Langerhans play a central role in glucose homeostasis by secreting the polypeptide hormones insulin and glucagon. They are comprised primarily of four endocrine cell types: insulin-secreting beta-cells which represent about 70% of the cells in the islet along with smaller number of cells secreting glucagon, somatostatin and pancreatic polypeptide. Diabetes mellitus results from the specific loss or dysfunction of the beta-cells. Because of the central role of the islets of Langerhans in the regulation of glucose homeostasis, we are preparing a database of genes expressed in this tissue. One thousand cDNA clones randomly isolated from a human pancreatic islet library were partially sequenced yielding 280 kilobases of sequence. Database searches indicated that 397 of the cDNAs represented known human genes or human homologs of genes identified in other species and a further 58 sequences corresponded to expressed sequence tags identified in other tissues or cells (contamination by exocrine pancreatic tissue was estimated to be less than 10%). 545 of the cDNAs were not related to any other sequences in the databases. The islet cDNA collection provides a unique source of genes for genetic studies of diabetes as well as for molecular studies of islet function in normal and diabetic states.

Animals↗
PubMed1993

Human oropharyngeal lesions with a defective Epstein-Barr virus that disrupts viral latency.

The Epstein-Barr virus (EBV), a human herpesvirus that is predominantly latent after infection, can be induced to replicate by deleted, rearranged EBV DNA from cultures of laboratory strain P3HR-1. Because mucosal surfaces are permissive of EBV replication, 101 oral biopsies from 70 Chinese and 5 American patients were examined for natural counterparts to tissue culture defective virus (WZhet), using as marker the abnormal juxtaposition of BamHI W and Z EBV DNA restriction fragments. Of the 49 oral biopsies that contained EBV DNA, 12 (24%) had the rearranged WZ fragment by polymerase chain reaction analysis: 3 (42%) of 7 EBV-positive epithelial dysplasias or carcinomas, 6 (38%) of 16 hairy leukoplakias, and 3 (12%) of 25 nonmalignant salivary gland biopsies. Accompanying viral replication was confirmed by in situ cytohybridization and demonstration of the linear configuration of the genome in select WZhet-positive lesions. These findings indicate that defective EBV with the unusual property of disrupting EBV latency is prevalent in natural infections and may contribute to EBV's pathogenic diversity.

Blotting, Southern↗
PubMed1993

Human, rodent, and canine pancreatic beta-cells express a sodium channel alpha 1-subunit related to a fetal brain isoform.

Voltage-dependent, tetrodotoxin-sensitive Na+ currents have been identified by the patch-clamp technique in rodent, canine, and human pancreatic beta-cells, but their exact role in insulin secretion remains uncertain. Misler et al. (Diabetes 41:1221-28, 1992) recently reviewed data showing that human and rat beta-cell action potentials differ, in that trains of Na(+)-dependent action potentials are seen in human (and canine) cells, but the vast majority of rat beta-cell Na+ channels are inactivated. We have now identified Na+ channel alpha 1-subunit mRNAs expressed in normal adult human, canine, and rat islets, and two insulinoma cell lines, by mRNA amplification (reverse transcription followed by polymerase chain reaction). cDNA sequencing showed that all amplified human islet products and the majority of rodent islet cDNAs are most closely related to the rat brain III alpha 1-subunit isoform, previously found to be expressed primarily in fetal rat brain. Canine islets expressed both brain II and brain III isoforms. Reverse transcription followed by polymerase chain reaction experiments with hamster and mouse insulinoma cell lines also showed expression of the message related to the rat brain III isoform. In situ hybridization of human pancreas sections using a partial human Na+ channel III cDNA probe showed the message to be expressed in the majority of islet cells, and not in the acinar tissue, confirming its presence in pancreatic beta-cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Cloning of thienamycin biosynthetase genes from Streptomyces cattleya.

A mutant Y3 blocked in the thienamycin biosynthetic pathway was obtained from thienamycin producing strain Streptomyces cattleya by NTG treatment. Preliminary cloning system has been established on the basis of studies on the conditions for protoplast formation, regeneration, as well as DNA transformation for Y3 mutant strain. The shotgun cloning was carried out from S. cattleya using pIJ680 as a vector and the Y3 mutant as a host. The transformant No. 12 produced a thienamycin-like substance identified by paper chromatography and HPLC analysis. A recombinant plasmid p6BC12, which has molecular size of 9.8kb and an insert of 4.5kb, could be recovered. Southern hybridization confirmed that the transformant No. 12 harbors the recombinant plasmid p6BC12. The intermediate accumulated by Y3 mutant was identified as a polypeptide. The product of transformant containing p6BC12 could turn this polypeptide to a bioactivity substance in vitro. This gene can hybridizate with S. lipmanii IPNS gene. We presume that a cyclase gene from S. cattleya was cloned according to the function of the expression product.

Cloning, Molecular↗
PubMed1993

Surveillance and care of four Chinese hemophiliacs with human immunodeficiency virus (HIV) infection.

Four Chinese hemophiliacs with HIV infection have been followed up in Zhejiang Province since 1985. A plan for optimal care of HIV seropositive patients was proposed, including surveillance and care; clinical follow-up and preventive education of asymptomatic HIV seropositive patients; keeping the disease confidential so as not to stir up unnecessary social unease; propaganda and health education about acquired immunodeficiency syndrome (AIDS); treatment with traditional Chinese medicines; and regular surveillance of family members and medical personnel. This plan is regarded as feasible and effective for the prevention and control of AIDS in China.

Acquired Immunodeficiency Syndrome↗
PubMed1993

The effect of prednisone on pancreatic islet autografts in dogs.

Prednisone was shown to induce hyperglycemia in dogs submitted to total pancreatectomy and pancreatic islet autotransplantation. The hyperglycemia caused by a 10-day course of prednisone, 1 mg/kg/day, starting on the day of operation was reversible within 1 week after steroid discontinuance. Three weeks after prednisone was stopped, there was no detectable adverse effect on glucose homeostasis as judged by fasting blood sugar levels and intravenous glucose tolerance test results. Four months after transplantation, glucose disappearance was delayed in animals previously treated with the prednisone compared with those previously treated with prednisone plus insulin or control animals. This was accompanied by lower insulin values on intravenous glucose tolerance testing and suggests a long-term subtle effect on islet function. The mechanism of the steroid effect is not known. However, this model could be used to test the diabetogenicity of other immunosuppressive agents including cyclosporine, FK 506, and azathioprine.

Animals↗