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Biomedical subjects

Q Zhang

Publications and source records attributed to Q Zhang.

At least 667 records · Page 37Linked to original sources
PubMed1997

[Quantitative determination of 7-ketocholesterol in human fetal liver cell supernatant and lysate by high performance liquid chromatography].

7-Ketocholesterol (7-KC), which is a major oxidation product of cholesterol and is selective cytotoxic to tumour cells, was isolated from human fetal liver. A fast, sensitive method of high performance liquid chromatography for the quantitation of 7-KC has been developed and applied to the determination of 7-KC in human fetal liver cell suspension. In this procedure a mixture of 2 : 1 chloroform-methanol (V/V) was used as extraction solvent. The extract was washed with distilled water and then evaporated to dryness under N2. An adsorption liquid chromatographic system used included mu-Porasil SiO2 column, hexane : iso-propanol (91 : 9) mobile phase and UV detector at 233nm. It was found that the level of 7-KC in human fetal liver cell supernatant was higher than in liver lysate.

Chromatography, High Pressure Liquid↗
PubMed1997

[Luminescence properties and energy transfer between Ce3+ and Tb3+ ions in KA1F4: Ce, Tb].

Matrix KA1F4 was prepared through reaction of mixtures of solution K2CO3 upon certain solution of Al(OH)3 plus HF(40%),dehydrating at 100 degrees C and annealing for 48hr at 450 degrees C. A series of KA1F4 : Ce,Tb phosphors were synthesized by a solid reaction method. Their excitation and emission spectra have been investigated. It was observed that Ce3+ can effectively sensitize Tb3+ in KA1F4, so as to enhance the emission of Tb3+ significantly. KA1F4 :Ce,Tb might be a new high efficient green emitting phosphor.

English Abstract↗
PubMed1997

[Far FT-IR spectra of gallium hexafluoride ions].

Far FT-IR spectra of Rb3GaF6, alpha-Cs3GaF6 and high temperature form Cs3GaF6 and their XDS have been studied in this paper. The results indicated that Rb3GaF6 and high temperature form Cs3GaF6 are tetragonal, a = 0.632,c = 0. 886nm and a = 0.687,c = 0. 987nm respectively. alpha-Cs3GaF6 is orthorhombic, a = 1. 062,b = 0. 996,c = 0. 561nm

English Abstract↗
PubMed1997

BCL6 can repress transcription from the human immunodeficiency virus type I promoter/enhancer region.

The gene BCL6 encodes a zinc finger protein with similarities to transcription factors. We previously reported that a number of viral genomes, including human immunodeficiency virus type I (HIV-1), contain sequences which are similar to the BCL6 DNA-binding consensus in their promoter regions. Electrophoretic mobility shift assays showed that the full-length BCL6 protein extracted from transfected COS cells and a bacterially expressed truncated protein containing the BCL6 zinc fingers can bind specifically to DNA from the U3 promoter/enhancer region of HIV-1. Transient transfections were performed to analyze the effects of the BCL6 protein on luciferase expression driven by the HIV-1 long terminal repeat (LTR) sequences. Full-length BCL6 significantly repressed luciferase activity compared with multiple controls. We conclude that the BCL6 protein can bind to the HIV-1 promoter-enhancer region and contains a domain upstream of its zinc fingers that can repress transcription from the HIV-1 LTR.

Animals↗
PubMed1997

[Study on relationship between personality traits and social life abilities in children].

Author surveyed 330 pupils and their parents by using Eysenck Pensonality Questionnaire (E. P. Q) and Infants-Junior Middle School Students' Social-Life Abilities Scale, to explore the relationship between personality and Social-life abilities in children. Result show there was no relationship between social-Life abilities and degrees of psychoticism, neuroticism and lie in children. It was closely related between social-life abilities and personality of children. The children with low social-life abilities are mostly introverted. The children with high social-life abilities, especially in communication, are mostly extroverted. Children over 10 year-old with high locomotion are mostly extroverted (P < 0.05). As results of the study, parents and pediatric nurses should assist the personality of children to be developed toward extroversion tendencies.

Child↗
PubMed1997

High responsiveness of cytosolic free calcium concentration to angiotensin II in cultured pulmonary arterial myocytes from pulmonary hypertensive rats.

Pulmonary arterial myocytes were cultured from normotensive and pulmonary hypertensive rats. Microfluorimetry of Ca2+ signals in fluo-3-loaded single myocytes at day 7 of culture was performed by a laser-scanned confocal imaging system. The resting level of cytoplasmic Ca2+ concentration ([Ca2+]i) in vascular myocytes obtained from hypertensive rats was higher than that in cultured myocytes obtained from normotensive rats. Angiotensin II elevated [Ca2+]i in the vascular myocytes cultured from both normotensive and hypertensive rats. However, a rise of [Ca2+]i induced by angiotensin II in the vascular myocytes obtained from pulmonary hypertensive rats was higher than that obtained from normotensive rats. On the other hand, the response of [Ca2+]i to A23187 did not differ between the vascular myocytes cultured from normotensive and hypertensive rats. The present results suggest that the resting and angiotensin II-responsive levels of [Ca2+]i in pulmonary arterial myocytes cultured from pulmonary hypertensive rats are higher than those cultured from normotensive rats.

Angiotensin II↗
PubMed1997

Responsiveness of cytosolic free calcium concentration in cultured rat pulmonary arterial smooth muscle cells: confocal microscopic measurement.

Rat pulmonary arterial smooth muscle cells were primarily cultured. alpha-actins in pulmonary arterial smooth muscle cells at day 7 of culture were observed by an immunofluorescence staining method using anti-alpha-actin antibody. Microfluorimetry of Ca2+ signals in fluo-3-loaded single smooth cell at day 7 of culture was performed by a laser-scanned confocal imaging system. The effects of several kinds of Ca(2+)-mobilizing drugs on cytoplasmic Ca2+ concentration ([Ca2+]i) were examined. KCl, a depolarizing agent, and norepinephrine, an alpha-adrenergic agonist, equally increased [Ca2+]i. Angiotensin II, a receptor agonist, and caffeine, a Ca(2+)-induced Ca2+ releaser, elevated [Ca2+]i in the same manner but was more potent than KCl and norepinephrine. Br-A23187, a Ca2+ ionophore, most potently increased [Ca2+]i. The present results suggest that drug receptors on plasma membrane, Ca2+ entry pathways and Ca(2+)-releasing mechanisms act normally, and that our cultured pulmonary arterial smooth muscle cells may be a good model for the study on the essential role of Ca2+ in vasoconstriction.

Adrenergic alpha-Agonists↗
PubMed1997

Axon-target interactions in the developing cerebellum.

After entering target regions, afferent growth cones grow among putative target cells, stop extending upon meeting target cells, and transit into a synaptic ending. During these events, signals are transmitted to and from target cells to stimulate programs of differentiation. Here we describe three approaches to unraveling mechanisms of these phases of synaptogenesis. First, dye-labeling in the intact cerebellum has revealed the orchestration of afferent ingrowth and contacts with target cells. Second, an in vitro model based on purified granule neurons has shed light on the role of target cells in the arrest of afferent extension. Third, coculture of purified granule neurons (parallel fiber afferents) with purified Purkinje cells has demonstrated facets of afferent regulation of target cell differentiation. These analyses have suggested molecular mechanisms that mediate maturation of afferents and their targets.

Afferent Pathways↗
PubMed1997

The study of IL-1 beta, TNF-alpha, IL-6 gene expression and plasma levels on hemodialysis before and after dialyzer reuse.

OBJECTIVE: To investigate the biocompatibility of dialyzer reuse. METHODS: Twenty-two hemodialysis patients were randomized into cuprophan (CU, 7), polymethylmethacrylate (PMMA, 7) and polysulphone (PS, 8) membrane groups to observe IL-1 beta, TNF-alpha, IL-6 gene expression and their plasma levels by using themselves as control with enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. RESULTS: Plasma levels of interlukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) were 14.07 +/- 3.32 pg/ml, 67.41 +/- 19.79 pg/ml, 83.67 +/- 40.34 pg/ml; 12.80 +/- 3.01 pg/ml, 49.65 +/- 9.75 pg/ml, 33.36 +/- 12.14 pg/ml and 14.41 +/- 3.16 pg/ml, 80.56 +/- 23.22 pg/ml, 48.14 +/- 16.01 pg/ml, respectively, after patients dialyzed with CU, PMMA and PS membranes. Plasma cytokine levels decreased after reuse compared with those before reuse in each group. But no significant difference was found between them (P > 0.05); the levels of IL-1 beta, TNF-alpha, IL-6 gene expression after reuse were 5.61 +/- 0.33, 2.11 +/- 0.12, 5.04 +/- 0.19%; 2.43 +/- 0.19, 1.29 +/- 0.11, 3.48 +/- 0.20% and 2.48 +/- 0.20, 1.24 +/- 0.11, 3.22 +/- 0.20% respectively by in situ hybridization, and 0.92 +/- 0.07, 0.63 +/- 0.05, 0.53 +/- 0.05; 0.61 +/- 0.06, 0.47 +/- 0.04, 0.37 +/- 0.03 and 0.59 +/- 0.05, 0.44 +/- 0.04, 0.38 +/- 0.03 by RT-PCR, respectively. After reuse there was significant decrease as compared with that before reuse (P < 0.001, P < 0.005 and P < 0.05, respectively). CONCLUSIONS: This suggested reprocessing dialyzer with formaldehyde reduced cytokine release and gene expression in peripheral blood mononuclear cells and enhanced dialyzer biocompatibility. It would be beneficial to reduce the dialysis cost and may reduce the complication related to a long term hemodialysis.

Adult↗
PubMed1997

Detection of chlamydia trachomatis by polymerase chain reaction assay in nonbacterial prostatitis.

OBJECTIVE: To evaluate the sensitivity and specificity of polymerase chain reaction (PCR) technique in comparison with diethylaminoethyl-dextran (DEAE-dextran)-treated HeLa cell culture method for detection of chlamydia trachomatis in nonbacterial prostatitis. METHODS: Thirty patients had symptoms of prostatitis for at least three months. None of them had evidence of urethritis on urethral Gram stain or recurrent bacteria. Routine localization of bacteria was negative. White blood cell count in expressed prostatic secretion (EPS) was more than 10 per high-power field (10/HPF). None of these patients had received antibiotics during the six weeks before the study, although all had received multiple courses of antibiotics for treatment of prostatitis syndrome. The EPS specimens from these patients were placed in 0.5-ml Eppendorf tubes and stored at -70 degrees C until they were processed for PCR and DEAE-dextran-treated HeLa cell culture. RESULTS: Six specimens were positive for C. trachomatis by both PCR and culture, and 21 were negative by both tests. There were three specimens with discrepant results, including two that were positive by PCR and negative by culture, and one that was positive by culture and negative by PCR. Comparing PCR technique with culture method, the sensitivity, specificity, positive predictive value and negative predictive value of the former were 85.7%, 91.3%, 75.0% and 95.5% respectively. CONCLUSIONS: PCR analysis of EPS is a highly sensitive and specific noninvasive technique for detection of chlamydia trachomatis. It provides a unique opportunity for early identification of or rapid screening for chlamydia trachomatis infection in patients with nonbacterial prostatitis. The reliability of PCR assay offers clinicians a clear indication for the initiation of treatment of chlamydia trachomatis infection.

Chlamydia Infections↗
PubMed1997

[Tissue and body fluid distribution of antibacterial agents in pregnant and lactating women].

OBJECTIVE: To determine the placental transfer and milk excretion of antibacterial agents. METHODS: A prospective study was conducted in pregnant and lactating women. The concentrations of 13 agents in tissue and body fluid were determined by bioassay or high performance liquid chromatography method. RESULTS: The results showed that metronidazole, ofloxacin, chloramphenicol, gentamicin and ampicillin crossed blood-placental barrier well, the ratio of fetal tissue or amniotic fluid/maternal serum drug concentration was higher than those of the other agents. The penetration of penicillins (except ampicillin) and cephalosporins was poor, but the drug concentrations were still reached therapeutic levels in the most tissues and body fluids. The placental transfer of amikacin, clindamycin and erythromycin was slightly higher than beta-lactams. The drug concentrations in breast milk was low, except metronidazole and erythromycin, the breast milk levels of the two drugs were more than 100% of maternal serum levels. CONCLUSION: Based on the results of the study and the consideration of possible adverse effects which may affect both the mother and the developing fetus as well as antibacterial activities of the drugs, the indications and reasonable use of the agents in pregnant and lactating period were recommended.

Anti-Bacterial Agents↗
PubMed1997

[Infective factors of adult secretory otitis media].

There were histories of the upper expiratory tract infection in 49 out of 86 cases in adult secretory otitis media (SOM). Among them, thirty two cases were administrated antibiotics a week ago when the effusions were collected. The patient's Eustachian tubes in twenty nine cases were clinically ventilated. The endotoxins were positive in 39 out of 86 specimen tested with limulus assay, among these specimen, bacteria were cultured from 11 specimen. The data exibited that the appearance of the SOM is related to the existence of the infective factors in the middle ear cavity. The upper expiratory tract infection before the onset of the middle ear effusions is one of the important causes inducing the disease. The lower rate of bacteria culture than that of endotoxins is related with the administration of antibiotics before the onset of the disease. The administration of antibiotics in the treatment of the middle ear effusions will help to elimilate bacteria in the cavity of the middle ear effusions, improve the ventilating function of the Eustachian tube and make the effusions turn to disappearance.

Adolescent↗
PubMed1997

[Changes of inflammatory mediator in aucte necrotizing pancreatitis and effect of somatostatin analogne stilamin in rats].

OBJECTIVES: To investigate the changes of inflammatory mediator in ANP and to explore the effectiveness of stilamin treatment on ANP. METHODS: SD rats were divided into experimental groups (ANP = 12, ANP + NS = 10, ANP + Stilamin = 12) and control group (NC = 10). Rat ANP models were made by retrograde injection of 3.5% sodium taurocholate 2.5 ml/kg into the pancreatic duct, and treated by intravenous injection of stilamin 84 micrograms.kg-1.d-1 or same amount of normal saline respectively. Serum IL-1 beta, IL-6, IL-12, TNF-alpha, PLA2, amylase and endotoxin were examined. Finally, the morphology and pathology of the pancreas, liver, lung, heart and kidney, as well as the electronmicroscopical investigation of liver and lung cells were observed. RESULTS: The mean IL-1 beta, IL-6, IL-12, TNF-alpha, in the ANP and ANP + NS group were higher than those in the ANP + stilamin group and Control group (P < 0.01). The endotoxin, amlyase, PLA2 level in the ANP + stilamin group was lower than those in the ANP and ANP + NS groups (P < 0.001). ANP significantly increased white blood cell chemotax and infiltration, as well as hemorrhagic focus in liver, kidney and lung, but the pathological examinations of the liver, pancreas, lung and kidney demonstrated much less destruction in the stilamin group. CONCLUSIONS: Inflammatory cytokins play an essential role to induce pathophysiological process of ANP, and its related MODS may be effectively prevented and treated by stilamin.

Animals↗
PubMed1997

[Clinical characterizations of familial diabetes mellitus associated with mitochondrial gene mutation].

OBJECTIVE: To discuss clinical features at diabetic subtype which is apparently caused by a single mutation in the mitochondrial tRNA(Leu(UUR)) gene. METHODS: According to WHO criteria of diabetes mellitus (DM), 130 patients with DM and the family history of DM (either NIDDM or IDDM) were screened by using genetic diagnosis. Clinical and laboratory analyses were made in three unrelated patients with the mutation in mtDNA and their relatives. RESULTS: Four unrelated subjects (3.1%) were detected with mutation at position 3243 of mitochondrial DNA. The nine diabetes patients from first degree relatives of three probands were also identified with the mutation, in which eight patients were associated with sensory hearing loss and required insulin therapy due to secondary failure to oral hypoglycemic agents. All these nine patients had a lower frequency of obesity in the past, and most of them had a mother with diabetes, were younger at diagnosis, and were generally accompanied by in paired insulin secretion. CONCLUSION: Since the patients have the clinical characteristics of maternal transmission, hearing loss and impaired insulin secretion, we conclude that maternally inherited diabetes and deafness (MIDD) is a new diabetes subtype associated with a single mitochondrial mutation.

Adult↗
PubMed1997

[A study of the mechanism of L-NNA on sleep inhibition].

In the present study, the sleep-waking cycle and the immunoreactivity of 5-HT-containing neurons in rats receiving intraperitoneal injections of N-Nitro-L-arginine (L-NNA, 50 mg/kg) and L-arginine (L-arg, 110 mg/kg) were observed respectively. The results showed that injection of L-NNA suppressed both slow wave sleep (SWS) and rapid eye movement sleep (REMS) and increased mean arterial pressure (MAP). L-arg markedly attenuated MAP, whereas SWS and REMS were unchanged. The effects of L-NNA on sleep and MAP were reversed by preinjection of L-arg. In comparison with control group, the positive cells in dorsal raphe nucleus (DR) and raphe magus nucleus (MnR) increased 2 h after injection of L-NNA. The effect was attenuated by preadministration of L-arg. All these results suggest that L-arg: NO pathway is involved in the regulation of sleep-waking cycle and the increment of the positive immunoreactivity of the 5-HT-containing neurons in the DR may be related to the sleep-suppressive effects induced by L-NNA.

Animals↗
PubMed1997

[Experimental study in vivo on implantation of autogenous tendon cells after combining culture with carbon fibers].

In order to investigate the possibility of repairing injuried tendon with living artificial tendon, after combining culture, subcultured autogenous tendon cells with carbon fibers were implanted into the calcaneous tendon of rabbits. In different stages, the synthesis of type I collagen and their relevant morphological changes were observed. The results showed as follows: after implantation, tendon cells continued proliferating. Four weeks after implantation, tendon cells were detached from the carbon fibers and proliferated and produced collagen among the carbon fibers. The collagen fibrils were linked with each other to formed a dense structure. In the linkage site, the collagen fibrils originated from the implants joined to that from the ruptured end of the tendon, which meaned that the implant was healed with the recipient tendon. Observed under scanning electronic microscope, the tendon cells were lined among the carbon fibers evenly and in order, the collagen fibrils joined each other and formed an network, the fibrils were lined parallel to the carbon fibers. Under transparent electron microscope, the nucleolus were clear and organelle were abundant.

Animals↗