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Biomedical subjects

T Zhang

Publications and source records attributed to T Zhang.

At least 397 records · Page 22Linked to original sources
PubMed1992

Release of peptide-YY from the dog pancreas.

The objectives of this study were to characterize the distribution of immunoreactive peptide-YY (PYY) in the dog pancreas and to examine whether vagal stimulation can release PYY from the pancreas. Levels of pancreatic polypeptide (PP) were also measured. PYY levels in extracts of the right lobe (0.43 +/- 0.03 ng/mg tissue) and head (0.35 +/- 0.12 ng/mg tissue) of the pancreas were approximately 10- to 20-fold higher than those in extracts of the stomach (0.03 +/- 0.01 ng/mg tissue; P less than 0.05) and left lobe of the pancreas (0.02 +/- 0.01 ng/mg tissue). However, PYY levels in extracts of the pancreas and stomach were significantly lower than PYY levels in extracts of the colonic mucosa (7.63 +/- 0.71 ng/mg tissue). PP levels were significantly (300-fold) higher in pancreatic extracts than in stomach and colonic extracts. Immunoreactive PYY and PP in pancreatic and colonic mucosal extracts coeluted with synthetic PYY and PP standards on HPLC. Electrical vagal stimulation of dogs resulted in a significant (P less than 0.05) release of PYY and PP, which was abolished by atropine treatment (2 mg/kg, iv). PYY levels in the pancreatic veins increased more quickly than in the peripheral veins. The integrated levels of PYY in the pancreatic veins [1.63 +/- 0.30 ng (0-30 min)/ml] were significantly (P less than 0.05) higher than those in peripheral veins [0.86 +/- 0.16 ng (0-30 min)/ml], but lower than those in colonic veins [3.14 +/- 0.22 ng (0-30 min)/ml]. Our results indicate that PYY is primarily produced in the colon; however, the pancreas contains a measurable amount of PYY, which is mainly distributed in the right lobe and head of the pancreas. In addition, PYY can be released from the pancreas in response to vagal stimulation. These data suggest that pancreatic PYY may participate in the regulation of pancreatic and gastrointestinal functions through endocrine and paracrine actions.

Animals↗
PubMed1992

[Isolation and characterization of prolactin messenger RNA from bovine anterior pituitary glands].

The messenger RNA was extracted from bovine anterior pituitary glands and was purified by oligo(dT)-cellulose chromatography. The length of the mRNA was 1,200 nucleotides measured by agarose gel electrophoresis containing methylmercury hydroxide. The bovine prolactin (PRL) mRNA was confirmed by Northern blot analysis of the mRNA with gamma-32P labelled synthetic oligonucleotide probes based on the partial amino acid sequences of bovine PRL and could stimulate the incorporation of 35S-methionine into protein in the rabbit reticulocyte cell-free system. The translation product of bovine PRL mRNA was immunoprecipitable by rabbit anti-ovine PRL anti-antibodies. The molecular weight of the translation product corresponding to the bovine PRL precursor was estimated to be approximately 25,000 by SDS polyacrylamide gel electrophoresis and autoradiograph.

Amino Acid Sequence↗
PubMed1992

[Factors related with stroke recovery].

81 patients with an average of 61 who had a hemispheric stroke for the first time and survived more than 12 months were followed in order to study the factors related with recovery. The results are: (1). The severity of the initial attack and the presence of depression and other complications in recovery period are the main relating factors with both the quality of life and recovery of neurological deficits. (2). The size of the lesion shown in CT is the main relating factor with the recovery of neurological deficits. (3). function of affected hand is a main relating factor with the quality of life. According to these results, it is essential to have a preliminary consideration to facilitate recovery at the initial stage of stroke and to organize the rehabilitation programs for the patients.

Activities of Daily Living↗
PubMed1991

Peptide YY, a new gut hormone (a mini-review).

This report describes our current knowledge of a new gut peptide hormone, peptide YY. The localization, action, and possible mechanisms that control release of peptide YY are described.

Amino Acid Sequence↗
PubMed1991

Substance P-containing neurons innervating LHRH-containing neurons in the septo-preoptic area of rats.

Neuroanatomical attempts have been made to determine the synapses between luteinizing hormone-releasing hormone (LHRH)-containing neurons and substance P (SP)-containing neurons in the hypothalamus of female rats. Wheat germ agglutinin was injected into the septo-preoptic area (SPA) and found to be incorporated into certain SP-containing neurons within the arcuate nucleus and the ventrolateral portion of the anterior hypothalamus. Hence, we used a preembedding double immuno-staining technique in demonstrating LHRH and SP neurons in the SPA. In light-microscopic preparations LHRH was labeled with 3,3'-diaminobenzidine tetrahydrochloride (DAB) as chromogen while SP was labeled with silver-gold particles; brown LHRH cells appeared to be surrounded by black silver-gold dots. In electron-microscopic preparations, the labelings for LHRH and SP were made reversely; SP was localized with DAB chromogen, and SP-containing axonal terminals appeared to make synaptic contacts on silver-gold-labeled LHRH cell bodies and dendritic processes. The terminals contained numerous small clear vesicles and some large dense-cored vesicles, and the synaptic membrane specialization appeared to be symmetric and asymmetric. These findings indicate that certain SP neurons existing in the arcuate nucleus and the ventrolateral portion of the anterior hypothalamus may project fibers to make synaptic contact with LHRH neurons in the SPA in the rat.

Animals↗
PubMed1991

[Transplacental passage of vanadium after treatment with vanadium pentoxide in Wistar rat].

The passage of vanadium pentoxide across the placenta into the embryo/fetus was investigated by analyzing the vanadium content in embryo/fetus at various intervals between 1 h and 48 h after treatment of pregnant Wistar rats with single dose of the V2O5 (5mg/kg) on days 16-18 of gestation, at 4h after treatment of pregnant rats with single dose of V2O5 (5mg/kg) on day 12, and at 120 h after treatment of pregnant rats with dose of V2O5 0.33, 1.0, 3.0 mg/kg on days 6 through 15. The V concentration was determined by catalytic polarography. At after treatment on day 12, the V concentrations in maternal blood, placenta and embryos were elevated in comparison with those of the untreated group. At 4-48 h after treatment on days 16-18, the V concentrations in placenta and fetuses were elevated in comparison with those of the untreated group. The V concentration at 4 h after treatment in various tissues is the highest one among different time points. On days 16-18, 4 h after treatment, the V concentration in placenta was elevated in comparison with that on day 12 of gestation, but the V concentration in embryo/fetus was decreased. At 120 h after treatment on days 6-15, the V concentration in fetus is still high in comparison with that of the untreated group. The V content of fetus varied according to doses, suggesting that embryo/fetus accumulates vanadium. The results showed that vanadium can pass through the placental barrier and enter the embryo/fetus during the embryonal organogenesis in rat, but placenta accumulates vanadium, and the barrier action increases with placental maturity.

Animals↗
PubMed1991

[Studies of the blood-group of chicken. X. Analysis of blood-group and plasma protein polymorphism in eleven Chinese native fowl breeds].

This paper reports the results of blood-group and plasma protein polymorphism of eleven Chinese native fowl breeds. 1. The distribution frequencies of the blood-group genes (3 loci 12 alleles) in eleven Chinese native fowl breeds were significantly different in A and C loci, but not significant in B locus. The coefficients of homozygosity of blood-group gene in all breeds were almost similar, except in Gushi and Chonren pitted chickens. The distribution of blood-group factors in all breeds was extensive, and this means that the selection potential in these local breeds was very large. 2. The gene frequencies of alkaline phosphatase (Akp and Akp-2) transferrin (Tf) in some breeds were more different, while that of esterase (Es-1) was less different. Among Chinese Japanese and American-European native breeds, the difference of gene frequencies of esterase was greater, while that of alkaline phosphatase and transferrin was smaller. It showed the identity or diversity in breed origin and evolution in these Chinese local breeds and Japanese or American-European native breeds. 3. The cluster analysis of the eleven Chinese native fowl breeds showed that these breeds could be divided into four groups: White ear-lobe- Shouguang- Luyuan chickens; Xiaoshan-Xianju- Pudong chickens; Langshan- Taihe Silky- Beijing Youkei chickens and Gushi-Chonren pitted chickens.

Alkaline Phosphatase↗
PubMed1991

[A study on developmental toxicity of vanadium pentoxide in NIH mice].

There is no general agreement yet about the teratogenic effects or developmental toxicity of vanadium in animal studies. This is a report on developmental toxicity in NIH mice following injection of vanadium pentoxide (V2O5, 5 mg/kg body weight, i.p.) at different times of gestation (on days 1-5, 6-15, 7, 8, 9, 10, 11, 14-17 of gestation). No adverse effects of V2O5 on pre-implantation and implantation were noted, and neither were teratogenicity and premature birth. However, there was toxic effect on embryofetus. Increased frequency of resorption or fetal death on days 6-15, 7, 14-17 of gestation were observed. Delayed ossification of bones was noted on days 6-15, 8, 10, 14-17 of gestation. These results suggest that V2O5 may be a weak developmental toxicant but not a teratogen in NIH mice. In addition, this paper reports the developmental toxicity, especially teratogenicity of N, N'-methylene-bis (2-amino-1, 3, 4-thiadiazole) which was used as the positive control in NIH mice.

Animals↗
PubMed1991

[Distribution of vanadium in tissues of nonpregnant and pregnant Wistar rats].

This paper reports tissue distribution of vanadium in nonpregnant and pregnant Wistar rats. The experimental results showed that vanadium concentrations in nonpregnant rats were respectively from high to low: I. no treatment: ovary greater than uterus greater than kidney greater than lung greater than heart muscle greater than spleen greater than brain greater than liver greater than blood; II. 4h after single i.p. injection of V2O5 (5 mg/kg): kidney greater than ovary greater than liver greater than bone greater than uterus greater than lung greater than heart muscle greater than spleen greater than brain greater than blood. The results suggest that female genital organs are important organs in distribution of vanadium. The kidney is a main excretory organ. After 24h of treatment, a larger amount of vanadium in body has been excreted. Vanadium can pass through blood-brain barrier. Distribution of vanadium on gestation days 12 after 4h single i.p. injection of V2O5 (5 mg/kg) is: kidney greater than ovary greater than uterus greater than placenta greater than liver greater than fetus greater than bone greater than heart muscle greater than lung greater than brain greater than spleen greater than blood; on gestation days 16-18 after 4h single i.p. injection of V2O5 (5 mg/kg) is: kidney ovary greater than placenta greater than lung greater than bone greater than uterus greater than heart muscle greater than spleen greater than fetus greater than liver greater than brain greater than blood; after 24h (on gestation days 16-18) is: kidney greater than ovary greater than placenta greater than spleen greater than bone greater than lung greater than liver greater than fetus heart muscle greater than brain blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Orthogonal test for the best conditions of treating licorice seeds with sulphuric acid].

Adopting the method of orthogonal test and using the orthogonal table of L25(5(6)), this paper has made a test of the influential factors in treating the licorice seeds with sulphuric acid. The result shows that the best treating conditions are as follows: H2SO4 concentration over 80%. H2SO4 amount 10-20 ml/kg. Treating temperature 10-25 degrees C. Treating time 2 hours.

Analysis of Variance↗