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Biomedical subjects

J Wei

Publications and source records attributed to J Wei.

At least 145 records · Page 8Linked to original sources
PubMed1998

TaqI polymorphic sites at the human dopamine beta-hydroxylase gene possibly associated with biochemical alterations of the catecholamine pathway in schizophrenia.

Two parts of the dopamine beta-hydroxylase (DBH) gene, one a 7.5-kb single copy fragment (F1) spanning the 5'-flanking region to exon 3 and the second a 9.0-kb single copy fragment (F2) spanning exon 3 to exon 7, were amplified by a long PCR procedure in 161 unrelated patients with schizophrenia and 67 unrelated control subjects. The PCR products were completely digested with the restriction enzyme TaqI. These subjects were classified into genetic subgroups according to the TaqI restriction fragment length polymorphisms (RFLPs) for the human DBH gene, and the association of the TaqI RFLPs with biochemical alterations of the catecholamine pathway in schizophrenia was then examined. The frequencies of the two TaqI polymorphic sites did not show significant differences between the patients and control subjects, but the TaqI RFLPs were found to be associated with biochemical alterations of the catecholamine pathway in schizophrenia.

Adult↗
PubMed1998

Association of the Ban I dimorphic site at the human cytosolic phospholipase A2 gene with schizophrenia.

There is evidence of increased phospholipid breakdown in cell membranes of patients suffering from schizophrenia. This may be related to increased levels of the enzyme cytosolic phospholipase A2 (cPLA2) which have been reported in schizophrenic subjects. We have identified a Ban I dimorphic site on the first intron of the cPLA2 gene. Schizophrenic subjects were found to have a significant excess of the A2/A2 homozygote relative to healthy control subjects. Genetically determined alterations in phospholipase activity may thus underlie the reported abnormalities of phospholipid metabolism in schizophrenia.

Cytosol↗
PubMed1998

Hypothalamic-pituitary-gonadal axis in the mutant weaver mouse.

The weaver (wv) mutant mouse manifests severe locomotor defects, a deficiency in granule cells of the cerebellum, and cellular deficits in the midbrain dopaminergic system. The wv phenotype is associated with a missense mutation in the pore region of the G-protein-gated inwardly rectifying potassium channel, GIRK2. The homozygous male wv mouse is essentially infertile due to an inadequate level of sperm production. Females are fertile although they also manifest the neurological phenotype. Homozygotes of both sexes have reduced body weight. We have evaluated the hypothalamic-pituitary-gonadal axis in heterozygote and homozygote male and female wv mutants in comparison with wild-type controls. Testicular weight was significantly reduced in the homozygous males, due to degenerative changes of seminiferous epithelium. Serum and pituitary content of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were normal in all groups, and the normal sex differences were noted (FSH and LH higher in males, prolactin higher in females). Pituitary growth hormone (GH) concentration was normal, with control and mutant males showing higher GH than females. Serum testosterone levels were normal in the mutants, as was testicular testosterone. Testicular alpha-inhibin content was mildly reduced, but high in proportion to testicular weight. The defect in spermatogenesis appeared predominantly in the postmeiotic stages. In situ hybridization was consistent with expression of some GIRK2 mRNA isoforms in seminiferous epithelium. There were no significant differences between genotypes in the levels of dopamine, dihydroxyphenylacetic acid, serotonin and 5-hydroxyindoleacetic acid in the mediobasal and preoptic hypothalamic regions. Homovanillic acid levels in these two areas were, however, reduced in wv homozygotes compared to wild-type animals. In the light of normal pituitary hormone levels, normal hypothalamic monoamine concentrations and normal sex differences in gonadotropins, we conclude that the infertility in the male homozygote wv mouse lies within the tubule and is probably a primary defect in the germ cells. The hormonal data suggest that Leydig cell function, and at least some aspects of Sertoli cell function, are normal in the mutant mice.

Animals↗
PubMed1998

Development and characterization of monoclonal antibodies specific to the serotonin 5-HT2A receptor.

Serotonin (5-hydroxytryptamine, 5-HT) mediates many functions of the central and peripheral nervous systems by its interaction with specific neuronal and glial receptors. Fourteen serotonin receptors belonging to seven families have been identified through physiological, pharmacological, and molecular cloning studies. Monoclonal antibodies (MAbs) specific for each of these receptor subtypes are needed to characterize their expression, distribution, and function in embryonic, adult, and pathological tissues. In this article we report the development and characterization of MAbs specific to the serotonin 5-HT2A receptor. To generate MAbs against 5-HT2AR, mice were immunized with the N-terminal domain of the receptor. The antigens were produced as glutathionine S-transferase (GST) fusion proteins in insect cells using a Baculovirus expression system. The hybridomas were initially screened by ELISA against the GST-5-HT2AR recombinant proteins and subsequently against GST control proteins to eliminate clones with unwanted reactivity. They were further tested by Western blotting against recombinant GST-5-HT2AR, rat and human brain lysate, and lysate from cell lines transfected with 5-HT2AR cDNA. One of the MAbs G186-1117, which recognizes a portion of the 5-HT2AR N-terminus, was selected for further characterization. G186-1117 reacted with a band of molecular size 55 kD corresponding to the predicted size of 5-HT2AR in lysates from rat brain and a 5-HT2AR-transfected cell line. Its specificity was further confirmed by adsorption of immunoreactivity with recombinant 5-HT2AR but not with recombinant 5-HT2BR and 5-HT2CR. Rat brain sections and Schwann cell cultures were immunohistochemically labeled with this MAb. G186-1117 showed differential staining in various regions of the rat brain, varying from regions with no staining to regions of intense reactivity. In particular, staining of cell bodies and dendrites of the pyramidal neurons in the cortex was observed, which is in agreement with observations of electrophysiological studies.

Aged↗
PubMed1998

Properties and tissue distribution of mouse monomeric carbonyl reductase.

We previously cloned a cDNA for mouse cerebellum carbonyl reductase which shows more than 81% homology to the cDNAs for monomeric carbonyl reductases of the rat, rabbit and human, and for pig 20beta-hydroxysteroid dehydrogenase. In the present study, we expressed the recombinant monomeric enzyme (34 kDa and pI 8.3) from the cDNA and compared its properties with the recombinant human enzyme. The mouse and human enzymes showed similar functional properties, although they differed in kinetic constants for carbonyl substrates and in inhibitor sensitivity. Both enzymes lacked glutathione S-transferase activity. Western blot and reverse transcription-polymerase chain reaction analyses showed that the enzyme protein and its mRNA are expressed in various mouse tissues.

Alcohol Oxidoreductases↗
PubMed1998

[Thallium poisoning a clinical analysis of 5 cases].

OBJECTIVE: To sumarize the clinical features, diagnosis and treatment of thallium poisoning by analysis of clinical cases. METHODS: Five cases of thallium poisoning were reported. The clinical manifestations, quantitative-analysed thallium level, methods and effect of treatment, and prognosis were analysed. RESULTS: Three of the 5 cases were acute, and the other two chronic. Four of them had a history of poison contact. The clinical features included alopicia (4 cases), transverse white stripes in the nails (Mee's stripes, 2) polyneuropathy, cranial nerve and central nervous system impairments (5), and abdominal pain and other digestion disturbances (3). All of the 5 cases were treated with antidotes and other methods to increase thallium excretion. One case died of lung infection 3 days after diagnosis. The serum and urine thallium levels of the 4 survivors decreased to normal after treatment (3 recovered, one had neurologic sequelae). CONCLUSION: It is not difficult to diagnose thallium poisoning by definite poison contact history, classical manifestation, and serum or urine thallium quantitative analysis. Attention should be paid to those patients with indefinite exposure to thallium. For those suspected cases, it is necessary to measure the thallium level in blood and urine in order to verify the diagnosis.

Adult↗
PubMed1998

[Influence of shenxu gutong capsule on femoral inorganic elements content and ash weight in rats].

OBJECTIVE: To explore the mechanism of Shenxu Gutong Capsule (SXGTC) in treating postmenopausal osteoporosis. METHODS: Using ovariectomized rats as the model of postmenopausal osteoporosis, the effect of SXGTC on inorganic element content of femur and femoral ash weight of the model rats were surveyed. Animals were divided into model group, SXGTC high dose group, SXGTC low dose group, positive control group (treated with Gushukang) and normal control group. The medication began at one week after operation and lasting for 120 days. RESULTS: The contents of inorganic elements, including Ca, P, Mg, Zn, Cu and Mn in the three medicated groups were higher than those of the model group (P < 0.01). The effect of SXGTC was dose dependent. The difference between the SXGTC groups and the positive control group was insignificant. The femoral ash weight of the SXGTC high dose group and the positive control group was significantly higher than that of the model group (P < 0.01). CONCLUSIONS: SXGTC could antagonize the rat's bony change caused by ovariectomy to increase the inorganic contents in bone, which may, in grneral, lead to a bone-strengthening effect.

Animals↗
PubMed1998

Temporal and spatial features of slow positive potential related to visual selective response during head-down-tilt.

The temporal and spatial features of visual ERP changes during 2 hour HDT (-10 degrees) were compared with that during HUT (+20 degrees) in 15 normal subjects. The stimuli consisted of two color LED flashes appeared randomly in left (LVF) or right (RVF) visual field with the same probability. The subjects were asked to make switch response to target signals (T) differentially: switching to left for T in LVF and to right for T in RVF, and making no response to non-target signals (N). Five sets of tests were made during HUT and HDT. ERPs were obtained from 9 locations on the scalp. Mean amplitude of the ERPs in the period 0.30-0.55 s were taken as the amplitude of slow positive potential (P400). The results obtained were: (1) The mean amplitude of P400 decreased during HDT which was more significant at the 2nd, 3rd and 5th set of tests; (2) spatially, the reduction of mean P400 amplitude during HDT was more significant for signals from RVF and were more significant at posterior and central brain regions than those from frontal locations. These data provide further evidence showing that the higher brain function was affected by the simulated weightlessness and that this effect was not only transient but also with interesting spatial characteristics.

Adult↗
PubMed1998

[Changes of brain potentials related to selective mental arithmetic during simulated weightlessness].

To study the effect of simulated weightlessness on brain function state, the brain event-related potentials (ERPs) during a selective mental arithmetic task were compared between head down tilt (HDT) and head up tilt (HUT) in 15 normal subjects. The results were: target (T) flash signals induced significant slow positive potentials and they decreased significantly in amplitude especially during HDT as compared with that during HUT. The data provide new evidence indicating that the ability of brain response declined during simulated weightlessness.

Adult↗
PubMed1998

[Noninvasive evaluation of cardiovascular autonomic regulation and its application in physiological studies under weightlessness].

Recent progress in the noninvasive evaluation methods of cardiovascular autonomic regulation, including autonomic function tests, baroreflex function assessment, and heart rate, blood pressure variability analysis were discussed, and the results of applying these methods in physiological studies on head-down bed rest, head-up tilt, lower body negative pressure and aerobic training were reported. It suggests that noninvasive evaluation methods of cardiovascular autonomic regulation are effective means in weightlessness physiology study.

Aerospace Medicine↗
PubMed1998

[The application of perfluoroethane made in China for treatment of retinal detachment].

OBJECTIVE: To evaluate perfluoroethane in the treatment of retinal detachment. METHODS: Various percentages of perfluoroethane were used and combined with routine scleral buckling and/or vitrectomy to treat 100 cases of retinal detachment. RESULTS: The reattachment rate of retinal detachment was up to 76.0% after 2 to 14 months of follow-up. CONCLUSION: Perfluoroethane is a safe, reliable and middle-effective intraocular gas tamponade.

Adolescent↗
PubMed1998

[Determination of steroidal saponins in Rhizoma paridis by RP-HPLC].

A reversed phase HPLC method for the separation and determination of nine steroidal saponins in Rhizoma paridis is described. The column was Symmetry C8, mobile phase was acetonitrile-water (42:58), UV detection was performed at 203 nm. The calibration curves showed good linearity over the range of 0.8-12.0 micrograms, gamma = 0.9996-0.9999, the recoveries were 97.1%-100.2% for the nine steroidal saponins. The method is simple, fast, sensitive and accurate and has been applied to the analysis of Rhizoma paridis. The results showed that the contents of the nine steroidal saponins in Rhizoma paridis were different with different sources.

Chromatography, High Pressure Liquid↗
PubMed1998

[Chitosan pin fixation of rabbit proximal tibia osteotomy].

Degradatable chitosan pin, 4 millimeters in diameter and 30 to 40 millimeters in length, was studied radiographically and histologically (oxytetracycline-labeling) at 3, 6, 12, 24 and 48 weeks after the implantation for fixation of a transverse proximal tibia osteotomy in fourty rabbits. The results showed that new bone formation and oxytetracycline uptake were increased 3-6 weeks after operation and the fracture was completely healed 12 weeks after operation, but in two rabbits the chitosan pin broke, in 3 weeks. Histologically, there was a massive inflammation (non-specific foreign body reaction) 3-12 weeks after implantation, which gradually subsided 24 weeks aften operation. Chitosan pin was slowly degradated in bone and was not replaced by normal tissue 48 weeks after operation. The questions to be addressed in future include how to increase the mechanical strength of chitosan pin and how to improve the characteristics of its surface.

Animals↗
PubMed1998

[Ultrasensitive analysis of R6G and R110 in solution].

This paper describes the ultrasensitive detection of R6G and R110 in a flowing aqueous sample, based on laser-induced fluorescence (LIF) combined with mode-locked pulsed excitation and time-correlated single-photon counting. A high repetition rate mode-locked argon ion laser operated at 514.5 nm was used as the excitation source. The laser beam was found tightly into a thin wall capillary flow cell. The probe volume was about 12.6 x 10(-12)L. Fluorescence was collected at 90 degrees using a x 40 microscope objective, and was detected by a fast response PMT detector. A time-gate was used to discriminate Raman scattering light background. Using the criterion of 3 standard deviations above background, the detection limits obtained for R6G and R110 were 3.8 x 10(-14) mol/L and 1 x 10(-13) mol/L respectively, and the average probability was lower than 1 in the presence of a R6G or a R110 molecule in the detection volume.

Lasers↗
PubMed1998

The association of serum anticholinergic activity with delirium in elderly medical patients.

To investigate the hypothesis that elevated serum anticholinergic activity is independently associated with delirium in ill elderly persons, the authors performed a cross-sectional study of 67 acutely ill older medical inpatients. The presence of delirium was evaluated with the Confusion Assessment Method, and the presence of many delirium symptoms was measured by the Delirium Symptom Interview. Demographic data and clinical characteristics that may be important for the development of delirium were also collected. Logistic regression techniques demonstrated that elevated serum anticholinergic activity was independently associated with delirium. Among the subjects with delirium, a greater number of delirium symptoms was associated with higher serum anticholinergic activity.

Aged↗
PubMed1997

Polyacrylamide gel electrophoresis coupled with matrix-assisted laser desorption/ionization mass spectrometry for tRNA mutant analysis.

In analogy to two-dimensional analysis, the mobility shift in native polyacrylamide gel electrophoresis (PAGE) due to a nucleotide substitution of a single-stranded transfer ribonucleic acid (tRNA) fragment serves as the first dimension for tRNA mutation analysis. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), as the second dimension, allows precise determination of the mass of the tRNA fragments resolved by native PAGE. Off-line combination of native PAGE with MALDI-MS is demonstrated for high-resolution analysis of tRNAval and its mutants, including a three-nucleotide deletion and 12 single-base substitutions. Three approaches, including direct extraction of tRNAs from gel into buffer solution, dissolution of membrane in the matrix solution, and direct desorption of tRNAs from the membrane, are studied for coupling native PAGE with MALDI-MS. The membrane dissolution method is simple, and the resulting mixture is amenable to MALDI-MS analysis. In the membrane dissolution method, as little as 1 microg or 40 pmol of tRNA sample is loaded on a native gel, separated, capillary eluted onto a nitrocellulose membrane, and recovered using the matrix solution of 2,4,6-trihydroxyacetophenone in acetone.

Base Sequence↗