Assignment and cloning of mouse Arhgap7 to chromosome 8A4-B2, a conserved syntenic region of human chromosome 8p22-->p21.
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Amino Acid Sequence↗
Biomedical subjects
Y Yang
Publications and source records attributed to Y Yang.
A role for leptin in sexual maturation and puberty?
Leptin, the ob gene product, is involved in the regulation of body weight in rodents, primates and humans. It provides a molecular basis for the lipostatic theory of the regulation of energy balance. White adipose tissue and placenta are the main sites of leptin synthesis. There is also evidence of ob gene expression in brown fat. Leptin seems to play a key role in the control of body fat stores by coordinated regulation of feeding behaviour, metabolic rate, autonomic nervous system regulation and body energy balance. Apart from the function of leptin in the central nervous system on the regulation of energy balance, it may well be one of the hormonal factors that signal to the brain the body's readiness for sexual maturation and reproduction. During late pregnancy and at birth when maternal fat stores have been developed, leptin levels are high. During these developmental stages leptin could be a messenger molecule signalling the adequacy of the fat stores for reproduction and maintenance of pregnancy. At later stages of gestation leptin could signal the expansion of fat stores in order to prepare the expectant mother for the energy requirements of full-term gestation, labour and lactation. Leptin serum concentrations change during pubertal development in rodents, primates and humans. In girls, leptin serum concentrations increase dramatically as pubertal development proceeds. The pubertal rise in leptin levels parallels the increase in body fat mass. In contrast, leptin levels increase shortly before and during the early stages of puberty in boys and decline thereafter. Testosterone has been found to suppress leptin synthesis by adipocytes both in vivo and in vitro. The decline of leptin levels in late puberty in boys accompanies increased androgen production during that time and most likely reflects suppression of leptin by testosterone and a decrease in fat mass and relative increase in muscle mass during late puberty in males. This overview focuses on those topics of leptin research which are of particular interest in reproductive and adolescent medicine.
Animals↗
Effect of chromosome 19 transfer on blood pressure in the spontaneously hypertensive rat.
Linkage studies in the spontaneously hypertensive rat (SHR) have suggested that a gene or genes regulating blood pressure may exist on rat chromosome 19 in the vicinity of the angiotensinogen gene. To test this hypothesis, we measured blood pressure in SHR progenitor and congenic strains that are genetically identical except for a segment of chromosome 19 containing the angiotensinogen gene transferred from the normotensive Brown Norway (BN) strain. Transfer of this segment of chromosome 19 from the BN strain onto the genetic background of the SHR induced significant decreases in systolic and diastolic blood pressures in the recipient SHR chromosome 19 congenic strain. To test for differences in angiotensinogen gene expression between the congenic and progenitor strains, we measured angiotensinogen mRNA levels in a variety of tissues, including aorta, brain, kidney, and liver. We found no differences between the progenitor and congenic strains in the angiotensinogen coding sequence or in angiotensinogen expression that would account for the blood pressure differences between the strains. In addition, no significant differences in plasma levels of angiotensinogen or plasma renin activity were detected between the 2 strains. Thus, transfer of a segment of chromosome 19 containing angiotensinogen from the BN rat into the SHR induces a decrease in blood pressure without inducing any major changes in plasma angiotensinogen levels or plasma renin activity. These results indicate that the differential chromosome segment trapped in the SHR chromosome 19 congenic strain contains a quantitative trait locus that influences blood pressure in the SHR but that this blood pressure effect is not explained by differences in plasma angiotensinogen levels or angiotensinogen expression.
Angiotensinogen↗
Autotaxin expression in non-small-cell lung cancer.
Autotaxin (ATX) is one of the newly discovered autocrine motility-stimulating factors with peptide sequences identical to those of the brain-type phosphodiesterase I (PD-Ialpha). Although ATX/PD-Ialpha is believed to play a role in tumor progression, its expression in various human cancers has not been extensively studied. We have studied the expression of ATX messenger RNA (mRNA) in normal human bronchial epithelial cell (HBEC) and non-small-cell lung cancer (NSCLC) cell lines, and in primary NSCLC with their corresponding normal lung tissues, using reverse transcription-polymerase chain reaction, Northern blot analysis, and in situ hybridization. ATX mRNA was commonly expressed in these cell lines and tissues. The predominantly expressed mRNA species corresponded to the ATX complementary DNA isolated from a human teratocarcinoma cell line. Overexpression of ATX mRNA was detected in seven of 12 (58%) tumor cell lines; however, there was no correlation between the levels of expression of ATX mRNA and the spontaneous motility of these cells. In situ hybridization localized ATX mRNA expression to the basal cells of normal bronchial epithelium, stromal B lymphocytes, and tumor cells. An overexpression of ATX mRNA as compared with its expression in normal bronchial epithelium was mainly found in poorly differentiated carcinomas. Our findings suggest that ATX may have roles additional to its motility-stimulating function in undifferentiated NSCLC.
Antigens, CD20↗
Genetics of Cd36 and the clustering of multiple cardiovascular risk factors in spontaneous hypertension.
Disorders of carbohydrate and lipid metabolism have been reported to cluster in patients with essential hypertension and in spontaneously hypertensive rats (SHRs). A deletion in the Cd36 gene on chromosome 4 has recently been implicated in defective carbohydrate and lipid metabolism in isolated adipocytes from SHRs. However, the role of Cd36 and chromosome 4 in the control of blood pressure and systemic cardiovascular risk factors in SHRs is unknown. In the SHR. BN-Il6/Npy congenic strain, we have found that transfer of a segment of chromosome 4 (including Cd36) from the Brown Norway (BN) rat onto the SHR background induces reductions in blood pressure and ameliorates dietary-induced glucose intolerance, hyperinsulinemia, and hypertriglyceridemia. These results demonstrate that a single chromosome region can influence a broad spectrum of cardiovascular risk factors involved in the hypertension metabolic syndrome. However, analysis of Cd36 genotypes in the SHR and stroke-prone SHR strains indicates that the deletion variant of Cd36 was not critical to the initial selection for hypertension in the SHR model. Thus, the ability of chromosome 4 to influence multiple cardiovascular risk factors, including hypertension, may depend on linkage of Cd36 to other genes trapped within the differential segment of the SHR. BN-Il6/Npy strain.
Animals↗
Embryonic mesenchymal cells share the potential for smooth muscle differentiation: myogenesis is controlled by the cell's shape.
Undifferentiated embryonic mesenchymal cells are round/cuboidal in shape. During development, visceral myogenesis is shortly preceded by mesenchymal cell elongation. To determine the role of the cell's shape on smooth muscle development, undifferentiated embryonic mesenchymal cells from intestine (abundant visceral muscle), lung (some visceral muscle) or kidney (no visceral muscle) were plated under conditions that maintained cell rounding or promoted elongation. Regardless of their fate in vivo, all the cells differentiated into smooth muscle upon elongation as indicated by the expression of smooth muscle-specific proteins and the development of membrane potentials of -60 mV and voltage-dependent Ca2+ currents, characteristic of excitable cells. Smooth muscle differentiation occurred within 24 hours and was independent of cell proliferation. Regardless of their fate in vivo, all the round cells remained negative for smooth muscle markers, had membrane potentials of -30 mV and showed no voltage-activated current. These cells, however, differentiated into smooth muscle upon elongation. The role of the cell's shape in controlling smooth muscle differentiation was not overcome by treatment with retinoic acid, TGF-beta1, PDGF BB or epithelial-conditioned medium (all modulators of smooth muscle differentiation). These studies suggest that the mesenchymal cell shape plays a main role in visceral myogenesis.
Animals↗
The expression of proUK in Escherichia coli: the vgb promoter replaces IPTG and coexpression of argU compensates for rare codons in a hypoxic induction model.
The expression of the proUK gene was improved by the coexpression of the argU gene cloned in a moderate copy number vector. As the proUK gene contains 2% AGG/AGA codons, which is much higher than the normal frequency in E. coli, about 0.14%-0.21%, the argU gene cloned in a multicopy plasmid was coexpressed with the proUK expression vector in our experiments. In E. coli strain BL21(DE3), IPTG is known to induce the expression of T7 RNA polymerase gene and this enzyme can transcribe the proUK gene under the control of the T7 promoter leading to expression of proUK. To replace IPTG by a cheaper alternative on a large scale, we constructed a plasmid in which the vgb promoter--which is known to be activated by the onset of hypoxic conditions--controls the T7RNA polymerase gene expression. Low oxygen conditions were then used to activate the vgb promoter causing T7RNA polymerase gene expression and finally leading to the expression of proUK as inactive inclusion bodies. Our experiments on a large scale in a bioreactor show that the expression of proUK accounts for about 30% of total protein after about 6 h of anaerobic cultivation, so the presented model represents an economical alternative to IPTG induction.
Bacterial Proteins↗
Production and characterization of an antibody specific for a novel protein serine/threonine kinase, MPK38, highly expressed in hematopoietic cells.
We report an antibody that selectively recognizes MPK38, a new protein serine/threonine kinase closely related to the SNF1 serine/threonine kinase family. This antibody recognized a region of the N-terminal kinase catalytic domain and part of the remaining C-terminal portion and was sensitive enough to detect a 72-kDa recombinant MPK38 in insect cells by Western blotting. Immunoblot analysis showed that the recombinant MPK38 was expressed in a time-dependent manner and reached a maximum after 48 h postinfection. In addition, the immune complex kinase assay revealed that the recombinant and endogenous MPK38 protein autophosphorylated in vitro. Phosphoamino acid analysis of autophosphorylated MPK38 protein showed that the phosphorylation was exclusively on serine and threonine residues, suggesting that MPK38 is a protein serine/threonine kinase. Thus, this antibody could be helpful for elucidating the biological functions of MPK38 in the MPK38-expressing cells.
Animals↗
Molecular analysis and heterologous expression of the gene encoding methylmalonyl-coenzyme A mutase from rifamycin SV-producing strain Amycolatopsis mediterranei U32.
The conversion of succinyl-coenzyme A (CoA) into methylmalonyl-CoA, catalyzed by adenosylcobalamin-dependent methylmalonyl-CoA mutase (MCM), represents an important source of building blocks for rifamycin SV biosynthesis. The structural gene for MCM from rifamycin SV-producing strain Amycolatopsis mediterranei U32 was isolated by using a heterologous gene probe encoding the MCM of Streptomyces cinnamonesis. A 7.8-kbp fragment was sequenced and four complete open reading frames (ORFs) and two incomplete ORFs were found. Two central ORFs, ORF3 and ORF4, overlap by four nucleotides and were found to encode MCM small (602 residues) and large (721 residues) subunits, respectively. Comparison showed that the MCM gene of A. mediterranei U32 was quite similar to those from other sources. The functionally unknown ORF5, immediately downstream of the mutAB gene, was quite similar to the ORFs downstream of mutAB from S. cinnamonensis and Mycobacterium tuberculosis. Such a striking cross-species conservation of gene order suggested that ORF5 could also be involved in the metabolism of methylmalonyl-CoA. MCM gene was overexpressed in Escherichia coli under T7 promoter, and MCM activity could be detected in the recombinant E. coli clone harboring MCM gene after the addition of coenzyme B12. A purification procedure based on the B12 affinity column was established to purify the MCM from E. coli. The molecular weight of purified MCM from E. coli was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis, which corresponds to that calculated from the MCM protein sequence and is also the same size as that of the enzyme purified directly from A. mediterranei U32. MCM gene was overexpressed in polyketide monensin producing S. cinnamonensis, and the total monensin production was increased by 32%.
Actinomycetales↗
An experimental study on the endurance of immunologic memory of intradermal micro-injection with rabies vaccine and boosting immune effect.
The purpose of the experimental study is to observe the effect of the immune recall responses induced by intramuscular (i.m.) injection with concentrated Primary Hamster Kidney Cell Vaccine(PHKCV) on days 180, 365, 545 and 730 after 0.1 mL nonconcentrated PHKCV was inoculated intradermally (i.d.), so as to determine the duration of the immunologic memory induced by i.d. 0.1 mL nonconcentrated PHKCV and chieve the goal of protecting the rabies patients with a short incubation. The results indicated that there were four intervals of 180, 365, 545 and 730 days between i.d. and i.d. PHKCV, the seroconversion rates being respectively 96.55%, 100%, 100%(180 day); 76.67%, 100%, 100%(365 day); 75.86%, 100%, 100%(545 day) and 75.00%, 100%, 100%(730 day) on days 7, 14 and 30 after the first dose i.m., the seroconversion rates of four experimental groups were all markedly higher than that of five routine doses (40.74%) (P < 0.01) on days 7 after the first dose i.m. The immune endurance of concentrated PHKCV and the enhancing immune effect of the vaccine following booster injection 365 days later were also observed. The results indicated that the seroconversion rates on days 180, 365 and 380 (on day 15 after boosting injection) were 96%, 83.33% and 100% respectively. The stated results prove that the concentrated PHKCV has better immune endurance and the immunologic memory induced by i.d. 0.1 mL nonconcentrated PHKCV can maintain two years. The immune effect inoculated by i.m. two or three doses on day 730 after i.d. 0.1 mL nonconcentrated PHKCV was better than that of five routine doses as the first time vaccination. If intradermal micro-injection were performed with higher titre of rabies vaccines, the longer time of immunologic memory would be maintained.
Adolescent↗
Phenotypic characteristics of early-onset autosomal-dominant type 2 diabetes unlinked to known maturity-onset diabetes of the young (MODY) genes.
OBJECTIVE: To investigate whether there are forms of early-onset autosomal-dominant type 2 diabetes that are distinct from typical maturity-onset diabetes of the young (MODY) and to characterize their phenotypic characteristics. RESEARCH DESIGN AND METHODS: The study included 220 affected subjects from 29 families in which early-onset type 2 diabetes occurred in multiple generations and was not linked to known MODY genes (MODY gene-negative families). All individuals underwent an oral glucose tolerance test and other clinical measurements aimed at investigating the underlying metabolic defect and the presence of diabetic complications. For comparison, 79 affected carriers of MODY3 (hepatocyte nuclear factor [HNF]-1 alpha) mutations were similarly examined. RESULTS: Subjects from MODY gene-negative pedigrees were diagnosed with diabetes at an older age (36 +/- 17 vs. 21 +/- 10 years, P = 0.0001) and were more frequently obese (52 vs. 18%, P = 0.0001) than MODY3 individuals. MODY gene-negative patients who were insulin treated required more exogenous insulin than did MODY3 subjects (0.7 +/- 0.4 vs. 0.45 +/- 0.2 U.kg-1.day-1, P = 0.04), despite similar C-peptide levels. Among subjects not treated with insulin, MODY gene-negative subjects had significantly higher serum insulin levels, both fasting (16.5 +/- 15 vs. 6.5 +/- 5 microU/ml, P = 0.027) and 2 h after a glucose load (53 +/- 44 vs. 11 +/- 10, P = 0.002). They also had higher serum triglycerides (P = 0.02), higher cholesterol levels (P = 0.02), more hypertension (P = 0.0001), and more nephropathy (P = 0.001). Differences persisted when families were matched for age at diagnosis. CONCLUSIONS: Our findings indicate the existence of forms of early-onset autosomal-dominant type 2 diabetes that are distinct from MODY and are frequently characterized by insulin resistance, similar to later-onset type 2 diabetes. Because of the Mendelian pattern of inheritance, the goal of identifying the genes involved in these forms of diabetes appears to be particularly feasible.
Adult↗
Kinetics of thermal inactivation of penaeus penicillatus acid phosphatase
The kinetics of thermal inactivation of Penaeus penicillatus acid phosphatase have been studied using a kinetic method related to the substrate reaction during irreversible inhibition of the enzyme activity as previously described by Tsou (Adv. Enzymol. Relat. Areas Mol. Biol. (1988) 61, 381-436). The kinetics of thermal inactivation of the enzyme show that the reaction is irreversible. The microscopic rate constants were determined for thermal inactivation of free enzyme and the enzyme--substrate complex. The results show that the presence of substrate has a significant protective effect against thermal inactivation of the enzyme.
Journal Article↗
[Distribution of six STR loci in Bai ethnic group in Yunnan province of China].
OBJECTIVE: This study was conducted to make known the distribution of six STR loci in Bai ethnic group in Yunnan province. METHODS: DAN extraction from blood samples (126 in number ) and multiplex amplification of CSF1PO,TPOX, TH01,F13A01, FESFPS and vWA were carried out. Using denaturing polyacrylamide gel electrophoresis and silver stain, the authors investigated the distribution of allele frequencies of CSF1PO, TPOX,TH01,F13A01,FESFPS and vWA loci in Bai ethnic group living in Yunnan province. RESULTS: 7 alleles and 19 genotypes of CSF1PO locus, 5 alleles and 11 genotypes of TPOX locus, 6 alleles and 16 genotypes of TH01 locus 6 alleles and 16 genotypes of F13A01 locus, 7 alleles and 15 genotypes of FESFPS locus,and 7 alleles and 21 genotypes of vWA locus were observed. CONCLUSION: The allele distribution of the loci was in good agreement with the Hardy-Weinberg equilibrium.
China↗
WT1, renal development, and glomerulopathies.
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Animals↗
[The establishment and application of genomic DNA extraction from peripheral blood].
OBJECTIVE: To establish the method of genomic DNA extraction. METHODS: Genomic DNA was directly extracted from peripheral blood with the use of potassium iodide. RESULTS: The genomic DNA extracted with potassium iodide was of large molecular weight. A(260)/A(280) and A(260)/ A(230) were 1.85 and 2.2 respectively. The extraction efficiency was greater than 90%. The result of PCR for the DNA was good. CONCLUSION: The method is simple, quick, economical and could be used for studying numbers of clinical samples.
DNA↗
Effect of aerobic exercise and ginsenosides on lipid metabolism in diet-induced hyperlipidemia mice.
AIM: To study the effect of aerobic exercise and its combination with Gin (ginsenosides from stems and leaves of ginseng) on lipid metabolism in diet-induced hyperlipidemia mice. METHODS: The mouse hyperlipidemia model was set up by feeding high cholesterol diet. Unloaded swimming was designed to be a manner of aerobic exercise. The effects of aerobic exercise and its combination with Gin on total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-c) in serum, malondialdehyde (MDA), and superoxide dismutase (SOD) in liver tissue were measured; the thymus and liver were weighed. RESULTS: (1) The mouse hyperlipidemia model was set up successfully: TC and MDA increased (P < 0.05) but HDL-c and SOD decreased (P < 0.05); the liver weight increased and the thymus weight reduced; fatty liver was found; (2) aerobic exercise reduced TC but increased MDA and HDL-c in cholesterol-rich diet mice; the liver weight did not reduce, and fatty liver did not clear up; and (3) when aerobic exercise combined with Gin, TC and TG decreased markedly (P < 0.01), and MDA also decreased (P < 0.05); SOD and HDL-c increased markedly (P < 0.01); the thymus weight increased and the liver weight decreased to normal level; fatty liver cleared up. CONCLUSION: Aerobic exercise could lower serum lipid to some extent but could not satisfactorily regulate lipid metabolism. When combined with Gin, aerobic exercise could better lower serum lipid, regulate lipid metabolism, promote antioxidation, and enhance immune activity.
Animals↗
[Clinical observation of hysteroscopic electric resection: an analysis of 36 patients with abnormal uterine bleeding].
OBJECTIVE: To assess the efficacy and influences of hysteroscopic electrosurgery in treating abnormal uterine bleeding (AUB). METHODS: 36 women with AUB received hysteroscopic transcervical resection of the endometrium or intrauterine lesions with a continuous flow resectoscope. RESULTS: The complications rate was 8.3%. 32 patients were followed for 4 to 12 months. Menstrual symptoms ameliorated in 82.4% of the patients. 5.9% of the women became amenorrhoeic. 58.8% had only spotting, 17.6% recovered normal period. 6 out of the 8 cases with dysmenorrhea had relieved their pain. Satisfactory rate of the procedure was 76.5%. Two patients received hysterectomy later for recurrent uterine bleeding. CONCLUSION: Hysteroscopic electrosurgery is an effective procedure in treating abnormal uterine bleeding. But its long-term efficacy is yet to be identified. When improving the technique and basic knowledge, the indications should be given appropriatly.
Electrosurgery↗
[The effect of vasectomy on spermatogenesis and proliferation of rat spermatogenic cell].
In order to explore the effect of vasectomy on spermatogenesis and proliferation of rat spermatogenic cell, we detected the DNA content of rat spermatogenic cells by flow cytometry at 4 weeks and 8 weeks after vasectomy. The results showed that the percentages of 1C cell group (spermatid and sperm) in the two experimental groups were apparently lower than that of the two control groups respectively (P < 0.05), but the percentage of 2C cell group (spermatogonium and spermotocyte) in the two experiment groups were much higher than those of the two control groups respectively (P < 0.05); The proliferation index (PI) of experimental groups was significantly lower than that of control groups (P < 0.05) and most of the cells in the experimental groups were on G0/G phase. The percentage of S-phase cell in the 8 weeks experimental group was obviously lower than that of the 4 weeks experimental group. These findings suggest that vasectomy in rat may affect many stages in spermatogenesis and delay the proliferation of spermatogenic cell.
Animals↗