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Biomedical subjects

Y Lin

Publications and source records attributed to Y Lin.

At least 559 records · Page 31Linked to original sources
PubMed1994

Cellular localization of tissue factor and prothrombin in the estrogen-treated immature rat uterus.

The immediate early responses of the immature rat uterus to estradiol include increases in tissue factor and prothrombin, two proteins of the coagulation cascade. Both attain maximum activity within 3 h after the administration of estradiol and return to control levels after 12-18 h. The presence of the two proteins allows the generation of thrombin (a known growth factor for fibroblasts) in the uterus at the time when uterine growth begins. To further our hypothesis that thrombin is an estrogen-regulated uterine growth factor, we used immunohistochemistry, Western blotting, and coagulation assays to localize the cell types in which these proteins are increased by estradiol. Tissue factor is increased in both the stromal and the epithelial cells. Increased prothrombin is localized primarily along the basement membrane that separates the epithelial and stromal layers and also at the luminal surface of the epithelium.

Amino Acid Sequence↗
PubMed1994

New nonionic triiodinated x-ray contrast media containing the N-(2-hydroxyethyl)aminopropane-2,3-diol side chain.

We have found the amino alcohol (HE)APD to be an effective solubilizing and detoxifying agent for triiodinated benzene XRCM. Most of the compounds containing the (HE)APD moiety displayed good solution properties (low osmolality and viscosity) and relatively low toxicities. A general trend was observed in which compounds with low hydrophilicity were more toxic. High hydrophilicity was found to be necessary for low intracisternal toxicity, but is not the only criterion. Use of the 5-glycolamido group provides compounds with high hydrophilicity. When all the properties were compared, the best compounds in this study were found to be the three asymmetrically substituted isophthalamides containing the (HE)APD and APD side chains (4a-c: MP-1556, MP-1683, and MP-1689). These compounds have excellent solution properties (low osmolality and viscosity) and low intravenous and intracisternal toxicities, and compare favorably to current clinical agents.

Animals↗
PubMed1994

Protective effects of a recombinant N-terminal fragment of bactericidal/permeability increasing protein on endotoxic shock in conscious rabbits.

Endotoxin (lipopolysaccharide, LPS) can induce shock, multiple organ failure, and death. A recombinant N-terminal fragment of bactericidal/permeability increasing protein, rBPI23, binds with high affinity to gram-negative bacterial LPS and neutralizes its biological activity. We sought to determine the effect of rBPI23 on LPS-induced respiratory dysfunction and cardiovascular depression in conscious rabbits. Rabbits were injected with Escherichia coli O113 LPS (6 micrograms/kg) and treated with rBPI23 (2 mg/kg), vehicle, or control protein after recovery from surgery performed to implant catheters for hemodynamic assessments and intravenous injections. LPS challenge caused respiratory dysfunction including tachypnea, significant decreases in arterial O2 tension (PO2), arterial oxygen content, and an increase in alveolar-arterial O2 gradient (A-aDO2). LPS administration also resulted in profound and prolonged decreases in mean arterial blood pressure and cardiac index. Treatment with rBPI23 prevented LPS-induced respiratory dysfunction and significantly ameliorated the cardiovascular depression. 5 of 16 LPS-challenged animals died of respiratory failure and acidosis, whereas none died in the rBPI23 treated group (p = .11). The results demonstrate that rBPI23 protects animals against LPS-induced cardiopulmonary depression in endotoxic shock.

Analysis of Variance↗
PubMed1994

5' proximal regions of Arabidopsis nitrate reductase genes direct nitrate-induced transcription in transgenic tobacco.

Nitrate reductase (NR) is the first enzyme in nitrate assimilation, a critical process for plant survival. The regulation of NR gene expression is complex, involving both internal and external factors. Of these, nitrate induction of NR gene expression has been studied most extensively and is well conserved among bacteria, fungi, and higher plants. We are interested in understanding the mechanism of nitrate induction of higher plant NR genes. Here we describe promoter analyses of the 5' flanking regions of the Arabidopsis NR genes, NR1 and NR2, with respect to nitrate induction of gene expression. To facilitate these analyses, a nitrate induction procedure using T1 transgenic tobacco plants was established. Approximately 1.5-kb 5' flanking regions of the two Arabidopsis NR genes (NR1 and NR2) were fused to a reporter gene and its expression in transgenic plants was analyzed. Deletion analyses of these regions show that 238- and 188-bp 5' flanking regions of the NR1 and NR2, respectively, contain sequences responsive to nitrate induction.

Arabidopsis↗
PubMed1994

Vulnerability of conducted vasomotor response to ischemia.

Many vasoactive substances induce two responses, a direct effect at the site of application and a conducted response that spreads along the vessel length. In the microcirculation, we find that these two components of the vasomotor response display quite different sensitivities to occlusion and/or ischemia. Conducted vasomotor responses were induced in arterioles of the hamster cheek pouch by micropipette application of two test agents: phenylephrine (PE), which causes a receptor-mediated vasomotor response, and KCl, which causes an alteration in the membrane potential by a simple change in the K+ gradient. Ischemia was produced either by total occlusion of the vascular supply, which resulted in a complete cessation of flow in all vessels, or by venous occlusion, which was achieved by gradually inflating a pressurized cuff positioned across the pedicle of the pouch until venous return from the pouch was arrested while the feed arterioles remained patent. Both types of occlusion produced ischemia, the former with low intravascular pressure, the latter with high intravascular pressure. During both types of occlusion, arterioles were initially maximally dilated and unresponsive to both agonists, but over a subsequent 3- to 5-min period, resting arteriolar tone and local responses to both agonists returned. With total occlusion, the conducted response to KCl returned in parallel with the local response, whereas the conducted response to PE was diminished or absent. With venous occlusion, the local responses recovered as with total occlusion, but the conducted responses to both PE and KCl recovered as well.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[The expression of hepatitis C antigen in hepatitis and liver cancer tissues].

30 specimens of hepatocellular carcinoma (HCC) from laporotomy biopsy and 15 specimens of hepatitis from aspiration biopsy were subjected to hepatitis C (HCV) immunohistochemistry. Anti-HCV core monoclone antibodies and ABPAP detection method were used. The results showed that 5 specimens (17%) in the HCC group and 3 (20%) in the hepatitis group were positive, with a total positive rate of 18%. The expression pattern was scattered, located in the cytoplasm. There were positive signals in the para-carcinomatous tissues of the 5 positive cases of HCC, and there were scattered positive signals just inside the cytoplasm of the cancer cells in 3 positive HCC specimens.

Adult↗
PubMed1994

[Chinese strain of hepatitis D virus: molecular cloning and sequencing, and the significance of its genome divergence].

The hepatitis D virus (HDV) obtained from a chronic asymptomatic HDV/HBsAg carrier (SZ 93) in Sichuan province was cloned with 1,684 nucleotides in full-length genome by reverse transcription-PCR. Comparison of SZ 93 with those obtained from different geographic area: i.e., Italia, United States, British, Nauru, Taiwan, Netherland, showed 81.8%-95.4% homology in nucleotide sequence of whole genome, 88.9%-96.1% homology in nucleotide sequence of HDAg-coding region, and 86.4%-93.0% homology in amino acid sequence of HDAg protein. Also, another isolate (SZ 92) obtained from a chronic severe hepatitis patient in Sichuan was cloned with HDAg-coding region. There were some mutations in SZ 92 compared with SZ 93 as well as the other clones mentioned above. The meaning for the genome divergence of HDV SZ 93 and SZ 92 was discussed.

Adult↗
PubMed1994

[Investigation on traditional Chinese medicine and Western medicine susceptible factors on senile cataract].

In 743 cases, the TCM and WM susceptible factors of senile cataract (SC) was studied by the clinical epidemiological investigation. By single factor analysis, the result showed that in WM, the susceptible factors of SC mostly related to (1) case history: coronary heart disease, old ages, smoking, multiple offsprings; (2) physical sign: short build, with coronary sulcus, higher systolic pressure, pulse pressure and average arterial pressure; (3) cardiovascular function: abnormal EKG, higher heart beat index, short microcirculatory stasis time, lower carrier viscosity of blood; (4) dysfunction of brain; (5) deficiency of pulmonary function; (6) lower RBC ATPase, higher whole blood reduction viscosity. While in TCM, it was related to (1) old aged and general asthenia, (2) deficiency of Qi, Heart, Liver or Kidney, (3) Blood Stasis. By stepwise regression analysis, the result showed that SC occurred through the combination with 13 factors of TCM and WM, including Yin Deficiency, senility index, hemorheology index, brain function, pulmonary function, blood pressure, body height, character, optical fundus, etc.

Adult↗
PubMed1994

Study on application of the principle of eliminating stasis and refreshing spirit for acute stage of hemorrhagic apoplexy.

Patients with hemorrhage less than 30 ml or more than 30 ml but unsuitable for surgery were qualified as the subjects of observation in this study. Ninety-two cases were randomly divided into the elimination of stasis and refreshment of spirit therapeutic group (the treated group and the control group treated wholely with Western drugs, for a prospective study. The results showed that the therapeutic effect was better in the treated group than in the controls, the total effective rate accounting for 79.1% in the treated group (61.2% in the control group), while the ineffective rate accounted for 20.9% in the therapeutic group (38.8% in the control group).

Adult↗
PubMed1994

Potential artifacts in TBARS measurement in tissues from animals treated with antioxidants.

When measuring endogenous TBARS levels from tissues of animals (in vitro) the presence of exogenous antioxidants in the tissue is likely to interfere with the TBARS assay to give artificially low values. Such low values do not then reflect protection against peroxidation in vivo. The type and extent of the reduction in TBARS values depend on the TBARS assay conditions. Firstly there appears to be an initial (probably iron induced) burst of peroxidation during homogenisation, which is antioxidant susceptible. In addition added TBARS products are formed during the final heating stage in methods which retain membrane bound reactants throughout the assay, and this step is also susceptible to antioxidant presence.

Animals↗
PubMed1993

Molecular cloning of the human and monkey sperm surface protein PH-20.

The guinea pig sperm surface protein PH-20 has an essential function in sperm adhesion to the zona pellucida of guinea pig eggs. Fully effective contraception has been achieved by immunizing either male or female guinea pigs with purified guinea pig PH-20. Here we report the isolation of human and cynomolgus monkey PH-20 cDNAs as a key step toward testing the function of primate PH-20 and the contraceptive efficacy of PH-20 immunization in primates. The deduced amino acid sequence of human PH-20 has 509 residues and is 59% identical with guinea pig PH-20, suggesting they may have a conserved function and immunogenicity. Southern blots show that there is a single PH-20 gene in the human genome and Northern blots of human testis poly(A)+ RNA show a 2.4-kb message. Northern blots of tissues other than testis are negative for PH-20, indicating that human PH-20 is testis-specific.

Algorithms↗
PubMed1993

Preparation of substituted N-phenyl-4-aryl-2-pyrimidinamines as mediator release inhibitors.

The role of immunologically released mediators, such as histamine, leukotrienes, and platelet-activating factor, is well-established for asthma and other allergic disorders. Developing therapeutic agents which would block mediator release from mast cells and other relevant cell types would provide a rational approach to asthma therapy. Using human basophil as a screen, a series of 4-aryl-2-(phenylamino)pyrimidines was found which inhibited mediator release. These compounds were prepared by condensing acetyl heterocycles with dimethylformamide dimethyl acetal to form enaminones which are cyclized with aryl guanidines to give pyrimidines. After examining a large number of analogs, N-[3-(1H-imidazol-1-yl)phenyl]-4-(2-pyridinyl)-2- pyrimidinamine (1-27) was chosen for toxicological evaluation.

Animals↗
PubMed1993

Affinity biosensors based on preconcentration/voltammetric analysis. Detection of phenothiazine drugs at Langmuir-Blodgett films of tyrosine hydroxylase.

A new route for operating affinity biosensors based on the voltammetric monitoring of the accumulated guest (analyte) is described. High sensitivity and selectivity accrue from the coupling of the specific receptor binding process and the inherent sensitivity of the preconcentration/pulse-voltammetric scheme. The redox (measurement) process results in dissociation of the receptor-guest complex, thus allowing multiple analytical determinations. The receptor layer also serves as an effective barrier that excludes interfering species. The new concept of preconcentration/voltammetric affinity biosensors is illustrated in connection with the detection of phenothiazine drugs using Langmuir-Blodgett films of their receptor, the enzyme tyrosine hydroxylase. The effect of various experimental variables upon the sensor performance is described.

Biosensing Techniques↗
PubMed1993

Characterization of linear and cyclic glucagon analogs by fast atom bombardment mass spectrometry.

Fast atom bombardment mass spectral mapping of endoproteinase Asp-N digest mixtures is used for characterization of new synthetic linear and cyclic glucagon analogs. The results allow rapid identification of sequence modifications in linear glucagon analogs. For the cyclic compounds, the technique allows confirmation of the presence and position of the cyclic amide bond, as well as verification of the sequence of the modified glucagon analogs. The specificity of the Asp-N enables differentiation of isometric glucagon analogs which differ only in the position of the cyclic amide bond. Important information concerning the purity of the synthetic analogs is also available.

Amino Acid Sequence↗