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Biomedical subjects

Q Zeng

Publications and source records attributed to Q Zeng.

At least 145 records · Page 8Linked to original sources
PubMed1995

[Plasma nitric oxide in patients with renal transplants].

The plasma nitric oxide (NO) in 32 patients with renal allografts was observed before transplantation and in the early period of three months after transplantation. Endothelin (ET), cyclosporin A blood concentration, Creatinine (Cr), blood urea nitrogen (BUN) were measured simultaneously. The results showed that plasma NO level (24.01 +/- 1.15 mumol/L) before transplantation was significantly higher than that after transplantation. There was significant correlation between plasma NO level and ET, Cr, BUN and blood pressure. We consider that plasma NO concentration may reflect the function of renal transplant and play an important role in early renal injury after kidney transplantation.

Adult↗
PubMed1995

Glycoconjugates and keratin 18 define subsets of taste cells.

Sections of neonatal, normal adult and denervated adult rat tongue were examined with lectin histochemistry. Attention was focused upon intragemmal cells (cells within the taste bud) and the surrounding perigemmal cells. Informative staining patterns were observed with four of 12 lectins: Ulex europaeus (UEA-I), Bauhinia purpurea (BPA), Helix pomatia (HPA) and Lotus tetragonolobus (LTA) agglutinins. In normal adult tongues, BPA bound to those lingual epithelial cells lacking contact with the basal lamina. After they formed, vallate taste buds were laterally surrounded by distinctive BPA-positive cells. HPA reacted selectively with 28% and LTA with 23% of the intragemmal cells in vallate/foliate taste buds. In double-stained taste buds there was a statistically significant overlap of LTA-positive cells and keratin 18-positive cells. The overlap between HPA binding and keratin 18 was more marked: double-stained cells comprized 67% of all stained cells. During taste bud development in neonates keratin 18 synthesis preceded HPA binding. In contrast, during the replacement of adult taste cells, keratin 18 synthesis and HPA binding were generally concurrent. Keratin 18 and HPA probably identify the same subset of older taste receptor cells. HPA may bind to glycoconjugates on the surface of keratin 18-positive cells. In denervated adult tongue the loss of all UEA-I-positive or BPA-positive perigemmal cells suggests that perigemmal as well as intragemmal cells are nerve-dependent.

Animals↗
PubMed1994

Cell specific expression of a vasopressin transgene in rats.

A transgene consisting of the rat vasopressin structural gene containing a reporter in exon III, flanked by 5 kb of upstream and 3 kb of downstream sequences, is expressed in vasopressinergic, but not oxytocinergic, magnocellular neurons of rats. Functionally appropriate physiological stimuli increase transgene expression in magnocellular neurons in an exaggerated fashion; the magnitude of the transgene response to osmotic challenge exceeds that of the endogenous gene by 10-15 fold. Magnocellular vasopressinergic neurons in the rat are now accessible to rational and precise genetic perturbation of function and regulation.

Animals↗
PubMed1994

Expression of a rat vasopressin transgene in rat testes.

The rat vasopressin gene contains two transcriptional promoters; the activity of one is confined to the hypothalamus, while the other is testis specific. To define the sequences mediating the cell-specific expression of the vasopressin gene, we introduced rat vasopressin transgenes into the rat germ line. Neither transgene 1.5-V beta gal-0.2, which consists of the entire vasopressin structural gene containing a 3 kbp beta-galactosidase reporter element in exon III, flanked by 1.5 kbp upstream of the start of hypothalamic transcription and 0.2 kbp downstream of the polyadenylation site, nor transgene 3-V beta gal-0.2, which consists of the entire VP structural gene containing a 3 kbp beta-galactosidase reporter element in exon III, flanked by 3 kbp upstream of the start of hypothalamic transcription and 0.2kbp downstream of the polyadenylation site, were expressed in the hypothalamus. This contrasts with a previously described transgene consisting of the rat vasopressin structural gene containing a reporter in exon III, flanked by 5 kbp of upstream and 3 kbp of downstream sequences, which is expressed in vasopressinergic hypothalamic neurons. Both the 3-V beta gal-0.2 and 1.5-V beta gal-0.2 transgenes were expressed in testicular germ cells using a promoter located within the beta-galactosidase reporter element. Transgene RNA was most abundant during the late stages of meiosis. Rats bearing vasopressin-beta-galactosidase transgenes provide new models for the study of the mechanisms whereby an epigenetic choice is made between the use of a germ cell or a somatic promoter, and the stage-specific transcriptional regulation of a germ cell promoter during spermatogenesis.

Animals↗
PubMed1994

Effects of Panax notoginseng saponins on myocardial adenosinetriphosphatase.

Effects of total Panax notoginseng saponins (PNS) and Panax notoginseng saponin monomers Rb1 and Rg1 (Rb1, Rg1) on total ATPase and Na(+)-K(+)-exchanging ATPase of guinea pig heart were studied. It was found that PNS inhibited the total myocardial ATPase, but had no significant effect on the myocardial Na(+)-K(+)-exchanging ATPase. The total ATPase was inhibited by Rg1, and more clearly by Rb1. The automaticity and contractility of isolated guinea pig atria were inhibited by Rb1. Rg1 decreased the spontaneous frequency of isolated guinea pig right atrium, but not markedly the contractility of the left atrium. These results demonstrate that Rb1 is the main ingredient in PNS.

Adenosine Triphosphatases↗
PubMed1994

Observation on the changes of plasma cardionatrion before and after microwave acupuncture in coronary heart disease.

This paper reports the therapeutic effect of microwave acupuncture (MWA) and its influence on the plasma level of cardionatrion. Twenty-eight cases with coronary heart disease (CHD) were systemically observed and investigated. Atrial natriuretic polypeptides (ANP) were determined by radioimmunoassay. Plasma level of ANP was elevated, the rising rate being 100%. The therapeutic effect of MWA in the 28 cases with CHD was 85.7%, the ECG improving rate was 82.2%. Effect of MWA was briefly discussed. The authors consider that the therapeutic effect of MWA in the treatment of CHD could be ascertained, and the measurement of plasma ANP concentration is a useful method and an objective parameter for further research.

Acupuncture Points↗
PubMed1994

Small-for-size liver transplanted into larger recipient: a model of hepatic regeneration.

Orthotopic liver transplantation was performed in 60 recipient rats weighing 200 to 250 gm. Sixty rats of the same strain were used as liver donors, 30 weighing 100 to 140 gm (small for size) and the other 30 weighing 200 to 250 gm (same size). After 1, 2, 3, 4, 7 and 14 days (n = 5 each) DNA synthesis, nuclear thymidine labeling and mitoses were increased in both the small-for-size and same-size groups, but significantly more in the former. These changes were maximal after 48 to 72 hr, similar to but later than the well-known regeneration response after partial hepatectomy, which peaks at 24 hr in rats. Indirect indexes of regeneration of the transplanted livers also were measured: plasma or serum ornithine decarboxylase; insulin and glucagon serum levels; estradiol and testosterone serum levels (and their nuclear and cytosolic receptors); and transforming growth factor-beta, c-Ha-ras and c-jun mRNA expressions. With the small-for-size transplantation, these followed the same delayed pattern as the direct regeneration parameters. The small livers gradually increased in size over the course of 1 to 2 wk and achieved a volume equal to that of the liver originally present in the recipient. In contrast, no significant liver weight gain occurred in the transplanted livers from same-size donors despite the evidence of regeneration by direct indexes, but not by most of the surrogate parameters, including ornithine decarboxylase.

Animals↗
PubMed1993

Rapid and simultaneous determination of monoamine oxidase A and monoamine oxidase B activities in mouse brain homogenates by liquid chromatography with electrochemical detection.

Sensitive and rapid enzymatic assays have been developed and optimized to measure the separate and combined activities of monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B) in mouse brain tissue homogenates using liquid chromatography with electrochemical detection (LCEC). The selectivity for the two isozymes is primarily afforded by use of selective substrates, 5-hydroxytryptamine (5-HT) for MAO-A and 3-methoxy-4-hydroxybenzylamine (MHBA) for MAO-B. The selectivity of the separate assays is further enhanced by the use of inhibitors, deprenyl to block MAO-B and clorgyline to block MAO-A. The dual assay procedure, which employs no inhibitors, shows remarkably enhanced selectivity for each of the isozymes through the use of the two substrates; the preferred substrate for one isozyme acts as an effective competitive inhibitor of the nontargeted substrate for that isozyme, leading to substantially decreased activity for the latter substrate. Using the dual assay, kinetic constants determined for MAO-A (mean +/- SD) were: Km,5-HT = 39 +/- 7 microM, Vmax,5-HT = 37.6 +/- 2.1 pmol/mg wet tissue/min, Km,MHBA = 341 +/- 75 microM, and Vmax,MHBA = 27.7 +/- 2.3 pmol/mg wet tissue/min; those for MAO-B were: Km,MHBA = 108 +/- 11 microM, Vmax,MHBA = 44.3 +/- 1.2 pmol/mg wet tissue/min, Km,5-HT = 1704 +/- 122 microM, and Vmax,5-HT = 12.0 +/- 0.3 pmol/mg wet tissue/min. The separate isozyme procedures, when used without selective inhibitors, reflect only 88.3% of the MAO-A activity using the 5-HT velocity and only 66.0% of the MAO-B activity using the MHBA velocity. On the other hand, when the dual assay is employed, 98% of the observed 5-HT velocity can be directly attributed to MAO-A, and 94% of the observed MHBA velocity can be directly attributed to MAO-B. The dual assay was employed to demonstrate the relative change in the activity of these two enzymes in whole mouse brain between 27 and 74 days of age. During this time, the MAO-B activity increased from approximately 40 to approximately 60% of the total MAO activity. Under typical conditions, results can be easily obtained from any of the three procedures outlined for 100 samples in less than 2 working days, including only 3.5 h for the LCEC portion.

Animals↗
PubMed1993

[Determination of plasma endothelin-1 in aged patients with chronic obstructive pulmonary disease in its clinical significance].

The levels of plasma endothelin-1 (ET-1) were determined by radioimmunoassay in 25 aged healty men and 88 aged patients with chronic obstructive pulmonary disease (COPD) at different stages. The results showed that plasma ET-1 levels of stable patients with COPD did not significantly change, but it were significantly higher during attacks than that in healthy subjects; The levels of plasma ET-1 in the patients with cor pulmonale were significantly higher than those in the healthy and COPD patients. Plasma ET-1 levels of patients with cor pulmonale at acute exacerbation stage were the highest in all groups. It was demonstrated that ET-1 correlated negatively to PaO2 and PH and correlated positively to PaCO2 and blood creatinine. This study suggested that the elevation of ET-1 level may contribute to the pathophysiological changes in patients with COPD and cor pulmonale.

Aged↗
PubMed1993

Cloning, sequencing and expression in E. coli of interferon-omega 1 gene.

Human interferon omega 1 (huIFN-omega 1) gene was isolated and cloned from chromosome DNA derived from a Chinese fetal liver via polymerase chain reaction (PCR). By determining its nucleotide sequence we proved that the 88th codon should be GGA, coding for Gly. After engineering the original IFN-omega 1 gene clone to a form that may be expressed as a nonfused protein, we also took the IFN-omega 1 gene under the control of the PRPL promoter with an expression vector pBV220 in E. coli. The antivirus activity of the recombinant IFN-omega 1 is about 6.5 x 10(7) units/L CULTURE (OD600 = 0.75). Since IFN-omega 1 not only has antivirus activity but also shows considerably high homology with animal trophoblast proteins which have been proved antiluteolysins as a maternal recognition signal for pregnancy, we believe that study on it will be practically and theoretically significant.

Amino Acid Sequence↗
PubMed1992

Neuropeptide gene expression in transgenic animals.

Transgenic animal techniques offer today's neuroscientist the ability to experimentally manipulate neurosecretory systems with a precision undreamt of by our predecessors. The range of techniques now available, building as it does on our growing knowledge of physiological systems at the inter- and intercellular level, allows us to critically define molecular lesions and ask about their consequences to the whole organism. Neuroscientist should grasp the opportunities afforded by these recent developments.

Animals↗
PubMed1992

[Effects of Panax notoginseng saponins on monophasic action potentials of heart and automaticity and contractility of isolated atria].

The effects of Panax notoginseng saponins (PNS) on monophasic action potentials (MAP) recorded from the myocardial surface by means of contact electrode were studied in 30 open-chest rabbits. The MAPA was increased and MAPD50, MAPD90 were prolonged with PNS (100, 200 mg.kg-1, iv), while the Vmax remained unchanged. PNS (300-1200 micrograms.ml-1) inhibited the automaticity of isolated guinea pig right atria and the contractility of the left atria. The positive inotropic action of ouabain (0.2 mumol.L-1) on isolated guinea pig left atria was decreased in the presence of PNS 300 micrograms.ml-1.

Action Potentials↗
PubMed1992

[Volatile oil in Ephedra sinica Stapf. and its processed products by GC-MS].

This paper deals with the changes in contents and chemical composition in the volatile oil of Ephedra sinica before and after processing. The results indicate that after processing, the more the substances of low boiling point, the higher their contents and vice versa. The changes are particularly obvious in yellow-fried Ephedra sinica.

Drugs, Chinese Herbal↗
PubMed1991

[Clinical observation of macular disease in patients with diabetic retinopathy].

The population was 65 cases (122 eyes) of diabetic macular disease. Background diabetic retinopathy was observed in 40 eyes, i.e., 32.80%. For the 82 eyes present proliferative diabetic retinopathy, i.e., 67.20%. According to Sigelmen's classification, 17 eyes were in stage I, i.e., 13.93% of the cases; 41 eyes were in stage II, i.e., 33.60% of the cases; 40 eyes were in stage III, i.e., 32.80% of the cases; 24 eyes were in stage IV, i.e., 19.67% of the cases. There were 122 eyes in this group. The visual acuity of 66 eyes showed > or = 0.3, i.e., 54.00%, while that of 56 eyes showed 40.3 i.e. 46.00%. Nearly half patients showed low visual acuity and loss of vision. This result was responsible for the cases who were at the late stage of diabetic and with a long history of diabetic or the diabetic was poorly controlled. So the writer appeal to ophthalmologists and physicians to prescribe the effective guides to all the diabetic patients. We suggest that it is important that dynamic observation be carried out of hemorhelological manifestation and early treatment diabetic retinopathy for the clinical prevention and treatment of diabetic retinopathy.

Adult↗
PubMed1989

The effect of different types of hepatic injury on the estrogen and androgen receptor activity of liver.

Mammalian liver contains receptors for both estrogens and androgens. Hepatic regeneration after partial hepatectomy in male rats is associated with a loss of certain male-specific hepatic characteristics. In this study we investigated the effects of lesser forms of hepatic injury on the levels of estrogen and androgen receptor activity in the liver. Adult male rats were subjected to portacaval shunt, partial portal vein ligation, hepatic artery ligation, or two-thirds partial hepatectomy. Another group of animals was treated with cyclosporine. At the time of sacrifice the livers were removed and used to determine the estrogen and androgen receptor activity in the hepatic cytosol. A significant reduction (p less than 0.05) in the hepatic cytosolic androgen receptor activity and a slight increase in the estrogen receptor activity occurred following total portosystemic shunting. Partial ligation of the portal vein, which produces a lesser degree of portosystemic shunting, had no effect on the levels of the estrogen and androgen receptor activity present within hepatic cytosol. Cyclosporine-treated animals had significantly greater (p less than 0.01) levels of estrogen receptor activity in the hepatic cytosol compared to vehicle-treated control animals. Levels of estrogen and androgen receptor activity within the hepatic cytosol remained unchanged after ligation of the hepatic artery. The reduction in the cytosolic estrogen and androgen receptor activity in the liver after partial hepatectomy was confirmed. In summary, certain types of hepatic injury are associated with profound changes in the estrogen and androgen receptor content within the liver.

Animals↗
PubMed1988

Studies on the regulation of renin genes using transgenic mice.

Transgenic mice are being used as an assay to identify the DNA sequences that direct the tissue specificity and physiological regulation of murine renin gene expression. In initial studies, a DNA segment encoding the duplicated renin gene, Ren-2, has been injected into the pronuclei of fertilized eggs homozygous for the Ren-1c allele. The 24 kb XhoI fragment utilized consists of 5.3 kb of upstream flanking sequences and 9.5 kb of 3' flanking sequence in addition to the 10 kb segment encoding the 9 exons of the natural gene. Seventeen transgenic founder mice were identified of which at least 7 exhibited evidence of transgene expression. The 4 expressing lines that have been studied in detail integrated from 5 to 15 copies of the transgene but expression was not proportional to the number of copies integrated. Qualitatively, expression is detected in the correct spectrum of tissues, and submandibular gland expression of the transgene responds appropriately to known hormonal modulators. However, quantitatively, the levels of expression deviate considerably from normal.

Animals↗