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Biomedical subjects

Z Dai

Publications and source records attributed to Z Dai.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Yu Jinghe's Chronicle].

The life and origin of medical learning from family of Yu Jinghe, renowned doctor of the Qing Dynasty, are described here in the form of chronicle. He was born in Yixing, Jiangsu. His parent died when he was a boy and he joined the Taiping Army for 5 years with difficult experiences. Later, he moved to Menghe and learned pharmacology from his elder brother. His works include Yu's Annotation on Shanghanlun Yi, Collection of Case Records on External Diseases, Collection After Practising Hour etc. Moreover, Yu's descendents and his close relationship with other modern celebrated doctors such as Ding Ganren and his son Ding Zhongying, and Yun Tieqiao are also mentioned.

China↗
PubMed1997

[Experimental research on the prediction of human body thermal responses in special hot environment].

The assessment of thermal environment is very important in the research of human body-thermal environment system. On the basis of systematic study, the characteristics and the components of human body-thermal environment system have been analyzed, the stationary mathematical model of human body-thermal environment system was established. Prediction and Assessment System for Thermal Environment (PASTE system) was developed. It consists of thermal environment monitor and simulator based on the IBM PC/XT computer with suitable hardware and software. Thermal environment monitor can measure fifteen parameters continuously including dry bulb temperature, dewpoint temperature, air velocity and thermal radiation in six directions. The simulator can simulate different heat exchange processes of human body-thermal environment system and human thermal responses. PASTE system is integrated with monitor and computer simulator. Test results showed that the differences between experimental result and predicted result were about +/-10%.

Body Temperature Regulation↗
PubMed1997

[Retrospective epidemiological study of pregnancy complicated by heart disease during 15 years in Shanghai].

OBJECTIVE: To investigate the changes of pregnancy complicated by heart disease. METHOD: Clinical data of hospitalized pregnant women with heart disease, collected from 10 teaching hospitals in Shanghai during 1981-1995, were analysed retrospectively. RESULTS: 2,680 of 379,065 deliveries (0.71%) were complicated by heart disease during that period. There were a total of 121 maternal deaths, 15 of them due to heart disease, the mortality of heart disease was 0.56%, and the percentage in total maternal deaths was 12.40%. The incidence and mortality rates were similar in 1981-1985, 1986-1990, 1991-1995, but the percentage due to heart disease increased after the late 1980s. The rates of congenital heart disease increased and rhumatic heart disease decreased apparently, the ratio of the former to the latter was 1.76:1. The pregnancy induced hypertension heart disease, the peripartum cardiomyopathy and the miscellaneous heart disease all increased obviously during the 1990s. The heart functions of grade I and II accounted for a considerable proportion (85.45%), but the grade IV tended to increase during the 1990s. Heart failure occurred in 172 cases, with an incidence of 7.6%. The perinatal mortality rate was 7.76%. Cesarean sections were often performed in heart disease women. CONCLUSION: Pregnancy complicated by heart disease is still one of the major cause of maternal deaths up till now. More effective management should be adopted.

Adult↗
PubMed1997

[Simultaneous determination of eight kinds of conjunct bile acids in human bile by R-HPLC].

A method for the simultaneous determination of eight kinds of conjunct bile acids in human bile was developed by HPLC. They were separated on a YWG-C18 (3 microns) column at 30 degrees C, with methanol/water (65/35, V/V, pH3.0) as mobile phase, and detection wavelength at UV 210 nm. The linear ranges were 50-1,000 microns.ml-1, the recoveries were 91.2%-108.6%. The biles of 30 cases with cholelithiasis cholecystolithiasis and 20 cases without gallstone were detected by HPLC. The results showed that the constitution of bile acids was different between patients with cholelithiasis cholecystolithiasis and patients without gallstone.

Bile↗
PubMed1996

In vivo actions of insulin-like growth factor-I (IGF-I) on cerebellum development in transgenic mice: evidence that IGF-I increases proliferation of granule cell progenitors.

The in vivo actions of insulin-like growth factor-I (IGF-I) on cerebellum development have been investigated in transgenic (Tg) mice (IGF-II/I Tg mice) in whom an IGF-II promoter-driven IGF-I transgene is highly expressed in cerebellum. Compared to normal littermates, the brains of IGF-II/I Tg mice exhibited overgrowth beginning from the second week of postnatal life. Among the brain regions examined, cerebellum exhibited the greatest increase in size, such that by 50 days of age cerebellar weight and DNA content were increased by 90% and 143%, respectively, compared to littermate controls. Morphological studies of adult IGF-II/I Tg mice showed that the total number of granule and Purkinje cells was increased by 82% and 20%, respectively, findings consistent with the increased cerebellar DNA content and indicating that the increased cerebellar weight was due in part to an increase in cell number. The thickness of the molecular layer also was increased in IGF-II/I Tg mice. During early postnatal development the number of external granular layer cells, as well as the number of BrdU labeled external granular cells, was increased. These data strongly indicate that IGF-I increases granule cell number by a mechanism that involves the stimulation of granule cell progenitor proliferation. Our findings also indicate that IGF-I influences the growth of Purkinje cells and possibly of other cell types in the cerebellum.

Animals↗
PubMed1996

Association of phosphotyrosine with rapsyn expression in Xenopus embryonic cells.

The postsynaptic membrane of the neuromuscular junction is highly enriched in rapsyn, which is thought to interact directly with nicotinic acetylcholine receptors (AChR) and anchor them at the synapse. We expressed rapsyn with or without AChRs in Xenopus embryos by mRNA injection. Co-expression of AChR and rapsyn caused the clustering of these two proteins in cultured cells isolated from the injected embryos. When rapsyn was expressed alone, it also became clustered at the substratum-facing membrane in cultured cells and at cell-cell contacts in whole mount embryos. No clusters were observed in cells that expressed AChRs alone. In rapsyn-expressing cells, proteins that are tyrosine phosphorylated as shown by anti-phosphotyrosine antibody labeling were concentrated at rapsyn clusters. Rapsyn itself does not appear to be a substrate for tyrosine kinase. This suggests that other phosphotyrosine-containing proteins are co-clustered with rapsyn in these cells.

Animals↗
PubMed1996

Dynamics of synaptic vesicles in cultured spinal cord neurons in relationship to synaptogenesis.

The dynamics of synaptic vesicles (SVs) during the development of presynaptic specializations in cultured Xenopus spinal cord neurons was studied with the fluorescent vesicular probe FM1-43. In naive neurons that have not contacted synaptic targets, packets of SVs are distributed along the entire neurite and are quite mobile. The interaction with the synaptic target, such as a muscle cell or a latex bead coated with basic fibroblast growth factor, results in the localization and immobilization of SV packets at the contact site. Depolarization resulted in exocytosis of SVs in both naive and target-contacted neurites. Okadaic acid, a phosphatase inhibitor, caused a dispersal of SV packets in both naive and target-contacted neurites. Thus, prior to target contact, SVs are already organized into packets capable of release and recycling by a phosphorylation-dependent mechanism. Target interaction then recruits and anchors these functional SV packets into forming the presynaptic nerve terminal. With fluorescent phalloidin as a probe, F-actin was found to colocalize with SV clusters at bead-neurite contacts. Although okadaic acid caused a dispersal of SVs at the beads, F-actin localization there was relatively resistant to this drug treatment. This suggests that SVs become localized at the target by interacting with an actin-based cytoskeletal specialization in a phosphorylation-sensitive manner. The induction of this cytoskeletal specialization by the target may be an early event in presynaptic differentiation.

Actins↗
PubMed1996

Promoter elements controlling developmental and environmental regulation of a tobacco ribosomal protein gene L34.

The rpL34 gene, which encodes a cytoplasmic ribosomal protein with a high homology to the rat 60S r-protein L34, was isolated from a genomic library of tobacco (Nicotiana tabacum L. cv. Xanthi-nc). A 1500 bp upstream promoter fragment was fused to the chloramphenicol acetyltransferase (CAT) reporter gene or beta-glucuronidase (GUS) reporter gene and transferred into tobacco plants by the Agrobhacterium-mediated leaf disk transformation method. Analysis of CAT activity in leaf tissues showed that mechanical wounding increased the rpL34 promoter activity about 5 times as compared to untreated controls and that the promoter activity was further enhanced by plant growth regulators, 2,4-dichlorophenoxyacetic acid and benzyladenine. Histochemical GUS staining patterns of the transgenic plants showed that the rpL34 promoter activity is high in actively growing tissues, including various meristems, floral organs, and developing fruits. A series of 5' deletion analyses of the rpL34 promoter indicated that a 50 bp region located between -179 and -129 is essential for wound, auxin and cytokinin responses. Deletion of this region reduced the promoter activity to an undetectable level. Insertion of the 50 nucleotide sequence into a minimal promoter restored the promoter activity and the promoter strength was proportional to the copy number of the upstream sequence. The role of TATA and CAAT box regions was studied by a series of 3' deletion analyses. A 3' deletion up to -28 did not significantly affect the promoter strength. However deletion of the promoter up to 70 bp, which deleted the TATA box region, significantly reduced promoter activity. Further deletion of the promoter up to - 104. eliminating the CAAT box region, abolished the promoter activity. These results suggest that the TATA box and CAAT box regions are also important for the rpL34 promoter activity in addition to the 50 bp upstream region.

Base Sequence↗
PubMed1996

[Selective embolization of coronary vein of the stomach--a new approach for the treatment of bleeding from esophageal varices].

Selective embolization of coronary vein of stomach was employed for the treatment of 222 patients with bleeding from esophageal varices due to portal hypertension. The coronary vein was separated at middle segment and tube was inserted and clamped 5 cm below and above the cardia. The gamma-octyl-cyanoacrylate was used for embolization. 19 patients received preventive operation, 106 was subject to emergency surgery and 98 patients was treated by elective operation. The bleeding of all patients receiving emergency procedure was stopped. 3 died of liver failure after operation. 219 survived. 189 cases were followed up for 1-2 years and on varices was found. 182 cases followed up for 6 years revealed no relapse of bleeding. This technique could achieve good curative effect, which provides a new approach for the treatment of bleeding from esophageal varices of portal hypertension.

Adolescent↗
PubMed1996

Synergistic renal protection by combining alkaline-diuresis with lipid peroxidation inhibitors in rhabdomyolysis: possible interaction between oxidant and non-oxidant mechanisms.

BACKGROUND AND PURPOSE: Heme-proteins, besides causing renal tubular obstruction, may contribute to rhabdomyolysis-induced renal injury through a heme-iron-mediated lipid peroxidation process. In the present study, we compared the combined therapy of a lipid peroxidation inhibitor, 21-aminosteroid (21-AS) and fluid-alkaline-mannitol (FAM) diuresis with either of them alone to determine the efficacy of the combination therapy and to delineate the roles of lipid peroxidation and cast formation. METHODS AND RESULTS: Employing Raman spectroscopy, we confirmed in vitro the ability of 21-AS to inhibit iron-induced fatty acid peroxidation. 21-AS was then administered to rats developing renal failure from glycerol-induced rhabdomyolysis. Although 21-AS inhibited rhabdomyolysis-induced plasma and renal lipid peroxidation, renal protection was incomplete. Administration of FAM to inhibit cast formation afforded a better renal protection. However, when these therapies were combined to inhibit both lipid peroxidation and cast formation, there was a synergistic renal functional protection. This was accompanied by a maximum inhibition of renal and plasma lipid peroxidation, as well as, renal tubular necrosis and cast formation. Compared to combination therapy, FAM therapy alone, despite identical volume, was accompanied by a higher tubular necrosis and cast formation. CONCLUSIONS: That combining a lipid peroxidation inhibitor with fluid-alkaline diuresis in rhabdomyolysis further lowers renal lipid peroxidation, tubular necrosis and cast formation and synergistically limits renal dysfunction (i) supports a role for lipid peroxidation in the pathophysiology of rhabdomyolysis ARF, (ii) underscores the role of the intratubular heme retention, a cause for tubular obstruction as well as a source for prodigious amount of iron, likely involved in the lipid peroxidation, and (iii) raises the possibility of interactions between non-oxidant and oxidant mechanisms.

Acute Kidney Injury↗
PubMed1996

[A preliminary study of biochemistry of patients with crystalline retinopathy].

PURPOSE: To investigate the pathogenesis and biochemical changes of crystalline retinopathy by detecting and analyzing the levels of trace elements (Cu++ and Zn++), blood-lipids and free amino acids in the serum of patients. METHODS: Blood samples of 10 patients with crystalline retinopathy and 30 normal subjects were collected. The levels of serum Cu++ and Zn++ were detected by using flame atomic absorption spectrometry, while cholesterol and triglyceride were detected by direct colordeveloping process and acetyl-acetone developing process respectively and serum amino acids by the Beckman amino acid analyzer. RESULTS: In comparison with the normal control group, the level of Zinc in serum was much decreased in the crystalline retinopathy group, while Cu++/Zn++ ratio and total cholesterol level in serum were significantly increased. In 3 out of 4 patients the level of taurine is lower than that of control group. CONCLUSION: The decrease of serum trace elements and taurine and the increase of cholesterol may be one of the important factors for the pathological changes of crystalline retinopathy. The administration of trace elements e. g. Zn++ and taurine might be a new therapy for the patients.

Adult↗
PubMed1996

Relationship between some humoral factors and left ventricular hypertrophy in essential hypertension.

OBJECTIVE: To evaluate the relationship between certain humoral factors and left ventricular hypertrophy (LVH) in essential hypertension. PATIENTS AND METHODS: 62 essential hypertension (EH) patients (32 men, 30 women; mean age, 55 years) and 20 normotensive healthy subjects (10 men, 10 women: mean age, 52 years) were studied. EH patients were divided into LVH group and non-LVH group by echocardiography. After an overnight fast, blood samples were taken for the determination of parathyroid hormone (PTH), angiotensin II (ATII) and aldosterone (ALD) by radioimmunoassay. RESULTS: There was a significant difference in PTH. AT II and ALD between the EH group and control group. Furthermore, in LVH group PTH, ATII and ALD elevated significantly as compared with non-LVH group. In addition, we found that LVMI (left ventricular mass index) correlated with ATII (r = 0.342, P < 0.01) and ALD (r = 0.356, P < 0.01). There was a more significant correlation between LVMI and PTH (r = 0.422, P < 0.0025). CONCLUSIONS: Some humoral factors are important determinants of LV mass. Besides the reninangiotensin-aldosterone system, PTH might play an important role in cardiac hypertrophy.

Aldosterone↗
PubMed1996

[Inhibitory effect of interleukin-10 on inflammatory reaction in rat mesangial cells].

OBJECTIVE: To investigate the inhibitory effect of IL-10 on inflammatory reaction in rat mesangial cells (rMC). METHODS: Cell proliferation was tested by 3H-thymidine uptake and absolute cell counts. The production of IL-1 and TNF alpha by rMC was assessed by bioactivity assay and their gene expression by Northern blot hybridization. The expression of intercellular adhesion molecule-1 (ICAM-1) on rMC was determined by ELISA. RESULTS: IL-10 (25 ng/ml) inhibited 5% FCS and IL-1 induced cell proliferation by 39% and 52% respectively. It also suppressed the production of IL-1 and TNF alpha bioactivity by rMC by 48% and 68%, which was consistent with the decline of IL-1 and TNF alpha gene expression. The IL-1-induced expression of ICAM-1 on surface of rMC was attenuated by IL-10 treatment. CONCLUSION: Our data suggest that IL-10 may be an inhibitory cytokine in regulation of inflammatory reaction in glomerular mesangial cells.

Animals↗
PubMed1995

Abi-2, a novel SH3-containing protein interacts with the c-Abl tyrosine kinase and modulates c-Abl transforming activity.

A protein has been identified that interacts specifically with both the Src homologous 3 (SH3) domain and carboxy-terminal sequences of the c-Abl tyrosine kinase. The cDNA encoding the Abl interactor protein (Abi-2), was isolated from a human lymphocyte library using the yeast two-hybrid system with the Abl SH3 domain as bait. Abi-2 binds to c-Abl in vitro and in vivo. Abi-2 is a novel protein that contains an SH3 domain and proline-rich sequences critical for binding to c-Abl. A basic region in the amino terminus of Abi-2 is homologous to the DNA-binding sequence of homeo-domain proteins. We show that Abi-2 is a substrate for the c-Abl tyrosine kinase. Expression of an Abi-2 mutant protein that lacks sequences required for binding to the Abl SH3 domain but retains binding to the Abl carboxyl terminus activates the transforming capacity of c-Abl. The properties of Abi-2 are consistent with a dual role as regulator and potential effector of the c-Abl protein and suggest that Abi-2 may function as a tumor suppressor in mammalian cells.

Adaptor Proteins, Signal Transducing↗
PubMed1995

Human insulin-like growth factor binding protein-1 (hIGFBP-1) transgenic mice: insights into hIGFBP-1 regulation and actions.

Three hemizygous transgenic (Tg) mouse lines were generated with a fusion gene composed of the mouse metallothionein promoter (mMT-1) and a full length human insulin-like growth factor binding protein-1 (hIGFBP-1) cDNA that was truncated in its 3' untranslated (3'UT) region. The transgene was ectopically expressed in the brain of each line and resulted in postnatal brain-growth retardation that was manifested by 2 weeks of age. Despite the expression of the transgene in multiple other tissues and high serum hIGFBP-1 concentrations in two of the three lines, studies designed to detect alterations in somatic growth, in reproduction and in glucose metabolism revealed few other abnormalities. Unexpectedly, however, we found that the regulation of the transgene shared characteristics with that of the native gene, despite the fact that it lacked the endogenous gene's 5' regulatory region, as well as most of its 3' UT region. Our studies suggest that factors controlling mRNA stability are important to regulation of both the native and transgene, and that an AU-rich element 17 base pairs (bp) from the end of coding sequence is responsible for the instability of the transgene and in part for instability of the endogenous gene.

Animals↗