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X F Zhou

Publications and source records attributed to X F Zhou.

84 records · Page 5Linked to original sources
PubMed1990

Capsaicin-sensitive nerves are required for glucostasis but not for catecholamine output during hypoglycemia in rats.

We have studied the glucose response and catecholamine (CA) response to insulin in the conscious rat to evaluate the role of sensory fibers in these responses in animals pretreated with capsaicin as neonates. In contrast to previous results obtained in anesthetized rats (Z. Khalil, B.G. Livett, and P.D. Marley. J. Physiol. Lond. 370: 201-215, 1986; Z. Khalil, B.G. Livett, and P.D. Marley. J. Physiol. Lond. 391: 511-526, 1987.), in conscious rats, insulin (1 IU/kg iv) produced only a mild hypoglycemia, which quickly returned to resting levels and caused no significant changes in plasma epinephrine levels. Somatostatin and SMS-(201-995), a somatostatin analogue, both potentiated and prolonged the insulin-induced hypoglycemia, resulting in an increase in circulating CA levels that was suppressed by hexamethonium and atropine. In capsaicin-pretreated rats the blood glucose levels at 90 min after insulin were significantly lower than those in vehicle-pretreated rats both in the presence (1 IU/kg insulin, 48 +/- 6 vs. 92 +/- 6 mg/100 ml, P less than 0.01) and absence (10 IU/kg insulin, 38 +/- 4 vs. 51 +/- 2 mg/100 ml, P less than 0.01) of SMS-(201-995). The CA levels in capsaicin-pretreated rats at 90 min after insulin were higher than in vehicle-pretreated rats (epinephrine levels: 27 +/- 4 vs. 10 +/- 1 pmol/ml in 1 IU/kg insulin, P less than 0.01; 64 +/- 14 vs. 25 +/- 5 pmol/ml in 10 IU/kg insulin, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Molecular cloning of a DNA segment essential for replication from Streptomyces hygroscopicus strain 10-22 and localization of its minimal functional region.

The 13 kb DNA segment responsible for replication has been isolated from Streptomyces hygroscopicus subsp. yingchengensis strain 10-22 using a pBR322-derived Streptomyces replication-probe vector pIJ2703. The restriction map of the hybrid plasmid, pHZ54, has been constructed. Following a series of deletion and subcloning experiments, the minimal functional region for replication was located within a 2.86 kb DNA fragment. Subsequently, this region was further shortened into a 2 kb region by exonuclease III deletion. A few small bifunctional plasmids able to replicate in E. coli as well as in Streptomyces, were obtained during the above process. Some plasmids could be used as shuttle vectors.

Cloning, Molecular↗
PubMed1989

[Mechanism of active oxygen in cytocidal activity of tetrabromofluorescein].

Photosensitization induced by tetrabromofluorescein (eosin, 3.8 mumol/L) in ascites hepatoma cells or in normal kidney cells of mice was found to be significant. The cytocidal activity increased in proportion to the concentration of fluorescein as well as with irradiation time. ESR signals were not detected using a trapping agent, 2,2,6,6-tetramethyltetrahydroxy-piperidine (TMHP) which functions as a singlet oxygen probe. No effect on photosensitization by superoxide dismutase (SOD), NaN3, histidine, mannitol or beta-carotene were observed. However, catalase did decrease photosensitization. These results indicate that cytocidal activity is not related to 1O2, O2-. or OH., but is related to H2O2. The cytocidal activity of tetrabromofluorescein in ascites hepatoma cells is stronger than that in normal kidney cells.

Animals↗
PubMed1989

Interspecific protoplast fusion of Streptomyces hygroscopicus var. yingchengenisis with Streptomyces qingfengmyceticus and biological characterization of their recombinants.

The frequency of recombination between Streptomyces hygroscopicus var. yingchengensis and Streptomyces qingfengmyceticus as a result of interspecific protoplast fusion was 4.5 x 10(-4). Characterization of biological properties revealed differences in spore mass color, drug resistance, antimicrobial activity, and antibiotic production capacity between the recombinants and their parents. Two recombinant strains, FL-42 and FL-48, exhibited production of the antibiotics originally elaborated by the two parents individually. They also produced two compounds with antimicrobial activity that their parents could not synthesize.

Anti-Bacterial Agents↗
PubMed1983

Cerebral infarction improved by safflower treatment.

The effect of safflower on cerebral infarction was studied in 152 Mongolian gerbils. Sixty-three animals were evaluated neurological deficit over 8 hours postoperation, then sacrificed and NE, DA and 5-HT contents of each cerebral hemisphere and brain stem were determined. NE, DA and 5-HT of hemisphere ipsilateral to the ligated artery in untreated animals declined significantly compared with sham-operated animals and safflower-treated gerbils. There was no significant difference between safflower-treated and sham-operated animals in NE, DA and 5-HT contents. The mean stroke index at 8 hours in safflower treated animals was 2.1 +/- 0.7, whereas untreated gerbils was 7.8 +/- 1.9 (P less than 0.01). Eighty-nine animals were followed up for 5 days, the safflower-treated animals showed a benign clinical course and mortality rate was reduced by 29.7% (6/34 vs. 26/55) in safflower-treated animals compared with untreated animals (P less than 0.01). Safflower has a protective and beneficial effect on cerebral ischemia induced in Mongolian gerbils.

Animals↗
PubMedDate not supplied

Roles of transforming growth factor-alpha and related molecules in the nervous system.

The epidermal growth factor (EGF) family of polypeptides is regulators for tissue development and repair, and is characterized by the fact that their mature forms are proteolytically derived from their integral membrane precursors. This article reviews roles of the prominent members of the EGF family (EGF, transforming growth factor-alpha [TGF-alpha] and heparin-binding EGF [HB-EGF]) and the related neuregulin family in the nerve system. These polypeptides, produced by neurons and glial cells, play an important role in the development of the nervous system, stimulating proliferation, migration, and differentiation of neuronal, glial, and Schwann precursor cells. These peptides are also neurotrophic, enhancing survival and inhibiting apoptosis of post-mitotic neurons, probably acting directly through receptors on neurons, or indirectly via stimulating glial proliferation and glial synthesis of other molecules such as neurotrophic factors. TGF-alpha, EGF, and neuregulins are involved in mediating glial-neuronal and axonal-glial interactions, regulating nerve injury responses, and participating in injury-associated astrocytic gliosis, brain tumors, and other disorders of the nerve system. Although the collective roles of the EGF family (as well as those of the neuregulins) are shown to be essential for the nervous system, redundancy may exist among members of the EGF family.

Animals↗
PubMedDate not supplied

Diagnosing anorexia based on partial least squares, back propagation neural network, and support vector machines.

Support vector machine (SVM), as a novel type of learning machine, for the first time, was used to develop a predictive model for early diagnosis of anorexia. It was based on the concentration of six elements (Zn, Fe, Mg, Cu, Ca, and Mn) and the age extracted from 90 cases. Compared with the results obtained from two other classifiers, partial least squares (PLS) and back-propagation neural network (BPNN), the SVM method exhibited the best whole performance. The accuracies for the test set by PLS, BPNN, and SVM methods were 52%, 65%, and 87%, respectively. Moreover, the models we proposed could also provide some insight into what factors were related to anorexia.

Anorexia↗