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Biomedical subjects

J Wei

Publications and source records attributed to J Wei.

At least 217 records · Page 12Linked to original sources
PubMed1995

Effects of endothelin 1 on calcium and sodium currents in isolated human cardiac myocytes.

We have used the whole-cell voltage-clamp technique to study the effects of endothelin 1 (ET-1, 10 nM) on L-type Ca2+ currents and voltage-dependent Na+ inward currents in human cardiac cells. Myocytes were enzymatically isolated from atrial specimens obtained during open-heart surgery and from human ventricular tissues of explanted hearts. Extracellular application of ET-1 decreased the peak amplitude of Ca2+ currents by 26 +/- 6% (n = 13) in atrial myocytes and by 19 +/- 3% (n = 8) in ventricular myocytes. In three atrial cells, treatment with 1 microM BQ123 prevented the decrease in Ca2+ currents induced by ET-1. When GTP (0.2 mM) was added to the dialyzing pipette solution, ET-1 still caused a small decline by 12 +/- 5% (n = 16), in peak Ca2+ currents, in atrial myocytes. When Ca2+ currents were increased (+210 +/- 19%) by a beta-adrenoceptor agonist (0.1 microM isoproterenol) or by the phosphodiesterase inhibitor isobutylmethylxanthine (10 microM), ET-1 reduced Ca2+ currents by 35 +/- 6% (n = 4) and 30 +/- 4% (n = 5), respectively. In human ventricular myocytes in the presence of 1 microM isoproterenol, which increased the peak Ca2+ currents by 150 +/- 30%, ET-1 also induced a drastic reduction in Ca2+ currents, by 40 +/- 11% (n = 5). The tetrodotoxin-sensitive Na+ currents measured in the presence of 5 mM [Na]o were significantly enhanced (+28 +/- 7%) by ET-1 in five atrial myocytes. The stimulatory effect of ET-1 on Na+ currents was partially reversible. The present findings in human cardiac cells show that ET-1 did not enhance the Ca2+ currents in the absence or presence of internal GTP. The positive inotropic actions induced by ET-1 in human heart may be mediated mainly by signal-transduction pathways other than the G-protein-adenylyl cyclase-cAMP system.

1-Methyl-3-isobutylxanthine↗
PubMed1995

Alterations in the expression of the genes encoding specific muscarinic receptor subtypes in the hypothalamus of spontaneously hypertensive rats.

A significant body of evidence exists that is consistent with the possibility that heightened cholinergic activity in certain brain regions, such as the hypothalamus, leads to increased sympathetic tone and subsequent hypertension. The increase in cholinergic activity is mediated at least in part through enhanced sensitivity of muscarinic receptors. In this study, we used the technique of reverse transcriptase-polymerase chain reaction to estimate the relative levels of mRNA encoding the five known subtypes of muscarinic receptors within the hypothalamus of spontaneously hypertensive rats (SHR), a genetic model of the disease, and their normotensive counterparts (Wistar-Kyoto rats). SHR exhibited a significant increase (40% to 50%) in the excitatory M1 subtype (confirmed by receptor binding) and a decrease in the inhibitory M4 subtype of muscarinic receptors before and during the establishment of hypertension. Such alterations may form part of the genotypic profile of inherited hypertension.

Animals↗
PubMed1995

Color appearance under chromatic adaptation varied along theoretically significant axes in color space.

Changes in color appearance caused by chromatic adaptation were measured with a wide range of adapting fields. Observers viewed a 39'-55' annular test field composed of an admixture of lights from the red phosphor and the green phosphor of a CRT. The annular mixture field was centered and superimposed upon a 4.7 degrees steady, circular background field. After the observer was completely adapted to the background, the luminance of the red phosphor in the test was held fixed while the observer adjusted the luminance of the green phosphor until the test appeared neither reddish nor greenish. Twenty-two equiluminant backgrounds (4.5 cd/m2, approximately 50 Td) were systematically selected along two axes in Judd chromaticity space. One axis was along tritanopic confusion lines, with middle-wavelength-sensitive- (M-) and long-wavelength-sensitive- (L-) cone stimulation held constant. The other axis maintained constant short-wavelength-sensitive- (S-) cone stimulation. The results show that adapting backgrounds that were varied along tritanopic confusion lines do not have a differential effect on color appearance at high test levels (well above the adapting level). At lower test levels there is a systematic change in color appearance of the test light, which is quantitatively described by additive redness. Along constant S-cone-stimulation lines, adapting backgrounds differentially affect color appearance in a systematic way, reflecting changes in receptoral gain and the additive contribution. The measurements taken with adapting fields throughout color space are described by the two-process model of chromatic adaptation.

Adaptation, Ocular↗
PubMed1995

[A new zoonosis--investigation of Gardnerella vaginalis disease of fox. II. Identification of pathogenic bacteria].

16 strains isolated from aborted foetus and vaginal exeretions of foxes were used for examination of cell morphology including fine structure of the cell wall and septa, test for homolysis, biochemical reactions and analysis of G+C content of the bacterial DNA. The cells are pleomorphic bacilli and coccobacilli, Gram stain reaction appear positive to variable, catalse and oxidase-negative, with a fermentative type of glucose metabolism, giving acetic and lactic acid as the major end products of fermentation. It's differentiated from the human strains of G. vaginalis by its less fastidious in growth requirements and being facultatively anaerobic to aerobic. We propose the name: a new subspecies--Gardnerella vaginalis subsp. fox, the type strain is U80.

Animals↗
PubMed1995

Morphology and morphogenesis of hepatitis E virus (strain 87A).

The morphology and morphogenesis of isolated hepatitis E virus (HEV, strain 87A) were observed by electron microscopy (EM) and immune electron microscopy (IEM). Progressively developing local vesicles, virions accumulation in crystalline arrays and viroplasmic focus were seen in cytoplasm of infected cells. Replication and assembly of the new generation viruses were closely associated with rough endoplasmic reticulum (RER), inclusion body (IB) and microfibrils. Condensation and margination of chromatin, dispersion of nucleolar material, nuclear membrane alteration and masses of threads, granular material, and fibrillar component of the nucleus were frequently found. These changes revealed that this strain virus was confirmed as a RNA virus. The shape of the virus particles appeared approximately spherical whether the specimens were from the tissue culture crude suspension or purified highly concentrated preparations. The size of the virion was about 30 nm in diameter. The viral particles appeared unsmooth and irregular in outline. The spike-like structures may be occasionally observed on the surface of some viral capsides. The diameter of the strain 87 A virus is larger than the picornavirus and smaller than the calicivirus. This strain virus is different from classical calicivirus in without the cup-shaped surface depressions. The new genus, heparnavirus genus of caliciviridae family should be proposed for HEV.

Hepatitis E virus↗
PubMed1995

Research of the exploitation of human resources in blind prevention and primary eye care.

PURPOSE: This research studied how to establish a relatively advanced blindness prevention and eye care cause in economically underdeveloped countryside. METHODS: Ophthalmic vocational schools and professional lectures were held to train "practical type" primary eye care workers for the countryside. Further study in high-level (above provincial) hospitals was taken to train blindness prevention & eye care backbones and leaders. RESULTS: In 1986, the ratio of the number of the eye care workers of all levels to the number of the whole population in the prefecture was 1:26,000. In 1992, it rose to 1:17,000. An eye care network of 222 stations had been established in the countryside. Ten in the 13 county hospitals had a seperated ophthalmology department, in which 3 were awarded "National advanced blindness prevention County". Twenty one hospitals were appointed as the Unit of Surgical Vision-Rehabilitation of Cataract. Blindness prevention and eye care covered 1,000,000 population (eye care available within 5 kilometers), 23.5% of the whole population. CONCLUSIONS: In a demographically large but economically underdeveloped countryside area, the key to wide-range blindness prevention and eye care is to exploit human resources effectively. We should train "Practical type" primary eye care workers, and have a number of department leaders who are authoritive, influential in this field and ready to sacrifice to this cause.

Blindness↗
PubMed1995

Harmful effects of MSG on function of hypothalamus-pituitary-target gland system.

It has been demonstrated that neonatal administration of monosodium glutamate (MSG) results in a clearly defined lesion of the arcuate nucleus (AN) of the hypothalamus. The present study shows that fat was accumulated in the abdomen of male rats treated with MSG; weights of the body, pituitary and testis were lower; beta-EP content in hypothalamus decreased while L.EnK content increased; serum LH, FSH, TSH, GH and TS levels all decreased in varying degrees while serum PRL level significantly increased. The cAMP content lowered in pituitary, but nor in testes; clear histological changes occurred in testicular tissue; Se-GSH-Px activity in both testis and adrenal gland lowered while LPO level significantly increased. Both Se-GSH-Px activity and LPO level in liver increased. These results indicate that MSG is harmful to the function of the hypothalamus-pituitary-target system of neonatal rats.

Adrenal Glands↗
PubMed1994

Analysis of region-specific library constructed by sequence-independent amplification of microdissected fragments surrounding weaver (wv) gene on mouse chromosome 16.

The C3-C4 region of mouse chromosome 16 was microdissected and amplified directly by sequence-independent amplification (SIA). The SIA product was proved to originate from the microdissected region by fluorescence in situ hybridization (FISH) and was cloned into the PCR II vector (mean insert size 506 bp). Colony hybridization showed that about 59% of the clones contained either unique or low copy number sequences. Southern blot analysis of 100 unique clones demonstrated that 50 clones hybridized with single (33 clones) or multiple (17 clones) bands on blots of DNA from a hamster-mouse hybrid cell line that contains mouse chromosome 16, 13 clones hybridized with mouse but not with the hamster-mouse hybrid DNA, 19 clones contained repetitive sequences, and the remaining 18 clones failed to yield bands. One third of the 100 unique clones hybridized to human genomic DNA. Thirty-three clones were sequenced. None of them was found in GenBank. Our results demonstrate that this relatively simple method of microdissection and cloning can produce a library of good quality.

Animals↗
PubMed1994

Increased serum IgE in schizophrenic patients who responded poorly to neuroleptic treatment.

Total serum IgE and plasma Interleukin (IL)-4 have been determined in patients with schizophrenia, 26 neuroleptic-free, and 81 neuroleptic-treated, and in 46 healthy control subjects. The total serum IgE was significantly higher in the patients who responded poorly to neuroleptic treatment compared with the other four groups (F = 4.27, df = 4, 148, P < 0.003). No significant changes were found in plasma IL-4 levels between any of the five groups. It is possible that raised serum IgE levels may characterise a subgroup of schizophrenia.

Adult↗
PubMed1994

m1-m5 muscarinic receptor distribution in rat CNS by RT-PCR and HPLC.

Five muscarinic receptor genes (m1-m5) that encode distinct muscarinic receptor subtypes have been cloned. Because of their structural homology and pharmacological similarity, ligand binding probes currently available do not clearly distinguish among the subtypes. To obtain a clear distribution within the CNS of molecularly defined muscarinic receptor subtypes, seven brain regions were examined for the expression of the respective mRNAs. The most sensitive method for detecting mRNA is through amplification of the respective cDNAs. Brain regions were obtained from male Wistar rats, and total RNA was isolated. The isolates were extensively treated with RNase-free DNase to remove any residual genomic DNA. Total RNA (1 microgram) was reverse-transcribed using random primers and reverse transcriptase. The resulting cDNA was amplified using a thermal cycler, and the polymerase chain reaction (PCR)-amplified products were analyzed by gel electrophoresis containing ethidium bromide and visualized with fluorescent illumination. PCR-amplified samples were also injected directly onto an HPLC anion exchange column and quantified by UV detection. Each of the five muscarinic subtypes was found in every brain region examined. The m1 subtype was most abundant in cortex and gradually declined in content caudally to the spinal cord. The m2 subtype was most abundant in thalamus-hypothalamus and ponsmedulla. The m4 subtype was found in greatest amount in the striatum, whereas m3 and m5 were expressed consistently throughout the CNS. The combination of RT-PCR and HPLC provides a rapid and sensitive method for quantifying the expression of mRNA coding for all five muscarinic receptor subtypes derived from the CNS.

Animals↗
PubMed1994

Genetic study of indirect inguinal hernia.

We performed a genetic analysis of 280 families with congenital indirect inguinal hernia ascertained in Shandong province. The multifactorial threshold model and segregation analysis were applied to these families to investigate the mode of inheritance of congenital indirect inguinal hernia. Our results indicate that congenital indirect inguinal hernia is not compatible with a multifactorial threshold model, and the frequent vertical transmission and high segregation ratio suggest autosomal dominant inheritance with incomplete penetrance and sex influence. Through further pedigree analysis of the multiple case families with at least two closely related affected members, we noted preferential paternal transmission of the disease gene, which might suggest the role of genomic imprinting in the aetiology of this condition.

Chi-Square Distribution↗
PubMed1994

Changes of plasma concentrations of interleukin-1 alpha and interleukin-6 with neuroleptic treatment for schizophrenia.

A significant difference of plasma interleukin (IL)-1 alpha concentration was found between schizophrenic patients taking neuroleptic drugs (n = 38) and those not taking them (n = 14; P < 0.02); Kruskal-Wallis analysis revealed a significant difference of plasma IL-6 concentration among the patients taking neuroleptic drugs, those not taking them, and healthy control subjects (H = 7.1, d.f. = 2, P < 0.05); also, there was a significant difference of plasma IL-6 concentration between the patients taking neuroleptic drugs (n = 32) and those not taking them (n = 13; P < 0.01). No significant differences were found between the three groups in the concentrations of IL-1 beta, IL-2 and tumour necrosis factor (TNF)-alpha. The present results suggest that neuroleptic treatment may change IL-1 alpha and IL-6 production in schizophrenic patients.

Adult↗
PubMed1994

[Restriction fragment length polymorphism of Bam HI and Rsa I loci in the retinoblastoma gene].

The retinoblastoma (Rb) gene probe p123 M1.8 and p68 Rs2.0 were used to study the frequencies of the Bam HI and Rsa I restriction fragment length polymorphisms (RFLPs) in the RB gene among the population of Han nationality in Guangdong province. The result showed that the heterozygote rate of the Rsa I locus was only 55.0%, remarkably different from reports in the literature. Linkage study of the Bam HI and the Rsa I RFLPs demonstrated that 10.5% of the Rsa I polymorphic loci were heterozygous for the Bam HI RFLP. Thus the combined use of the two RFLPs can give information for about 65.5% of the population.

Asian People↗
PubMed1994

[A new species of Pseudomonas].

A strain No. 9191 isolated from fruit juice mineral drink is gram-negative short-rod. It differs from reported species of Pseudomonas in morphological, physiological and biochemical characteristics. Main characteristics of No. 9191 are single polar flagelled, oxidase and catalase positive, no acid from glucose but producing alkali, nitrate reduced to nitrite, inability to hydrolize gelatin and starch, arginine dihydrolase absent, no growth in presence of 0.85% NaCl. The G+C mol% of DNA is 65.15. It is named Pseudomonas halosensibilis Zou & Cai nov. sp. by the sensibility property for salt.

Beverages↗
PubMed1993

Smith-Fineman-Myers syndrome: report on a large family.

Smith-Fineman-Myers syndrome is considered an X-linked mental retardation (XLMR) syndrome. Three families have been reported to date. However, none presented a typical pattern of X-linked inheritance. Here we reported on 5 males with Smith-Fineman-Myers syndrome with similar phenotypic expression as in those cases reported previously; they were distributed in 4 sibships of one large maternal kindred. This finding adds strong support to the hypothesis of the Smith-Fineman-Myers syndrome being a rare XLMR syndrome.

Child↗
PubMed1993

Retinoic acid-induced differentiation of a human neuroblastoma cell line alters muscarinic receptor expression.

Muscarinic receptor density increased by approximately 36% after differentiation induced by retinoic acid (Bmax, control = 126 +/- 13 fmol/mg protein; Bmax, retinoic acid-treated = 170 +/- 17 fmol/mg protein; P < 0.05), corresponding to a 170% increase in receptor content per cell. The affinity of [3H]NMS for the receptors was somewhat lower in the retinoic acid-treated cells (Kd, control = 0.14 +/- 0.04 nM; Kd, retinoic acid-treated = 0.25 +/- 0.04 nM; P < 0.05). Reverse transcriptase/polymerase chain reaction analysis using subtype-specific primers revealed that undifferentiated Sk-N-SH cells transcribed mRNA for all 5 receptor subtypes; this pattern was not affected by retinoic acid treatment. [3H]NMS displacement curves with subtype selective receptor ligands (pirenzepine, m1; AFDX-116, m2; 4-DAMP, m3) indicated the predominant expression of m3 and m1 receptor subtypes, and differentiation did not affect the pharmacological profile of the expressed receptor populations. The present results indicate that differentiation induces selective changes in the expression and activity of muscarinic receptors in a neuronal cell line.

Base Sequence↗