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F Z Wang

Publications and source records attributed to F Z Wang.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Effect of adenosine on intracellular free calcium in cultured rat hippocampal CA1 neurons during anoxia].

Intracellular free Ca2+ concentration ([Ca2+]i) was measured by laser scanning confocal microscope, using Ca2+ indicator Fluo-3 in cultured hippocampal CA1 neurons isolated from newborn rat. The results showed that acute anoxia induced a rapid increase of [Ca2+]i in hippocampal CA1 neurons, and this increase could be attenuated by 100 mumol/L adenosine significantly. This effect of adenosine could be suppressed by adenosine A1 receptor antagonist CPT or potassium channel blockers, 4-AP and glipizide. These results suggest that adenosine activates 4-AP- or ATP-sensitive potassium channels through A1 receptors, and consequently inhibits the [Ca2+]i elevation in hippocampal neurons during anoxia.

Adenosine↗
PubMed1996

Lymphotropic herpesviruses in allogeneic bone marrow transplantation.

Human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), Epstein-Barr virus (EBV), and human cytomegalovirus (CMV) DNA were repeatedly assayed in peripheral blood leukocytes from 37 allogeneic bone marrow transplant (BMT) patients by polymerase chain reaction. Before BMT, HHV-6 DNA was detected in 8 (22%) patients. HHV-7, EBV, and CMV DNA were detected in 21 (57%), 10 (27%), and 1 (3%) patient, respectively. After BMT, HHV-6 DNA was detected in 26 (70%), HHV-7 in 21 (57%), EBV in 28 (76%), and CMV in 21 (57%) patients. Thirty-two (87%) patients were positive with more than one virus. HHV-6, HHV-7, and EBV DNA were found earlier than CMV DNA in most patients after BMT. The proportions of HHV-6-positive samples during the first 3 months after BMT were higher in the patients with either delayed granulocyte engraftment (P = .04, Fisher's exact test) or delayed platelet engraftment (P = .001, Fisher's exact test). The HHV-6 DNA in samples from the patients with delayed engraftment was confirmed to be variant B. The detection of any lymphotropic herpesvirus was not related to the development of acute graft-versus-host disease (aGVHD). High-dose acyclovir (ACV) prophylaxis significantly (P < .01) reduced the proportion of HHV-6-positive samples and tended to lower HHV-6 DNA levels (P = .06). Our data indicate that HHV-6 variant B can inhibit marrow engraftment and that high-dose ACV may be beneficial to engraftment after BMT by preventing HHV-6 reactivation. No relation between the proportions of HHV-7-, EBV-, and CMV-positive samples in the first 3 months and engraftment or aGVHD was found.

Acyclovir↗
PubMed1996

Diagnosis of pulmonary infections in immunocompromised patients by fiber-optic bronchoscopy with bronchoalveolar lavage and serology.

Fiber-optic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) were performed on 67 occasions in 57 immunocompromised patients with symptoms consistent with pulmonary infection. Diagnosis was achieved more often in renal transplant patients than in patients with hematological malignancies (85% versus 28%). Culture (bacteria, virus, fungi), staining and microscopy (bacteria, fungi, Pneumocystis carinii (PC)) and antigen detection by indirect immunofluorescence (cytomegalovirus (CMV), respiratory viruses, PC, Legionella) were used for diagnosis. On 20 occasions transbronchial biopsies with histopathologic examination were performed. In addition, serology comprising the herpes group (HHV-6) and respiratory viruses was done. A microbial diagnosis was obtained on 45% of occasions. The most common pathogens found were CMV (31%) and PC (25%). On 22 (33%) occasions a rapid diagnosis of 1 or more microbial agents was obtained within 24 h by conventional staining or indirect immunofluorescence. The clinical relevance of findings of CMV, HHV-6, and Epstein-Barr virus in BAL by polymerase chain detection on 18, 6 and 3 occasions is discussed. On 4 occasions pathogenic bacteria were found. It was not possible to relate findings of coagulase-negative staphylococci, alpha-streptococci and Candida albicans to the pulmonary infection.

Adolescent↗
PubMed1996

[Involvement of the nerve fiber elements in the anterior pituitary in the regulation of ACTH secretion].

While peptidergic nerve fibers have been immunoreactively identified in the adenohypophysis of mammals, the function of these fibers in the regulation of hormone secretion remain unknown. The present work was undertaken to investigate possible modulating effects of these fibers on the secretion of ACTH in the anterior pituitary. Electrical field stimulation (EFS) was applied to excite the nerve terminals in anterior pituitary quarters of male rats under static incubation, and the ACTH level was determined by radioimmunoassay. It was found that the ACTH release from the anterior pituitary was significantly enhanced by EFS (30 mA, 0.5 ms and 10 Hz), which could be significantly decreased by adding TTX or veratridine into the incubation medium. However, TTX failed to inhibit AVP-induced ACTH secretion. Since the dispersed cultured anterior pituitary cells did not respond to the same EFS, it was suggested that there might exist dual modulatory mechanisms on the anterior pituitary hormone secretion.

Adrenocorticotropic Hormone↗
PubMed1995

[Effects of cytokines on hippocampus in central nervous system].

Cytokines consist of a group of polypeptides, whose main functions are considered to be mediating the non-specific immune reaction and promoting differentiation, proliferation and growth of white blood cells. But according to recent studies, these cytokines such as interleukin-1 (IL-1), interleukin-2 (IL-2) and interleukin-6 (IL-6) and their receptors are also found in the central nervous system (CNS) and may play a role in modulating the physiological functions of neuronal and glial cells in CNS. In review, we summarize the representative studies concerning mainly the interleukins' effects on the hippocampus.

Acetylcholine↗
PubMed1995

Effect of ginsenosides against anoxic damage of hippocampal neurons in culture.

AIM: To study the protective effect of ginsenosides (Gin) against anoxic injury in brain cells. METHODS: On d 12 after plating of the hippocampal cells from newborn rat, the cultures were exposed to anoxic atmosphere (95% N2 + 5% CO2) for 4-24 h. The cellular morphology, survival rate, and effluxes of lactate dehydrogenase (LDH) and K+ from cells were observed. RESULTS: After 24-h anoxia, the survival rate of cells was decreased from 92% +/- 4% before anoxia to 1.0% +/- 2.0%; the effluxes of LDH and K+ were increased from 2.3 +/- 0.6 U L-1 and 5.56 +/- 0.16 mmol L-1 before anoxia to 36 +/- 5 U L-1 and 8.5 +/- 0.7 mmol L-1, respectively. In the Gin group exposed anoxia for 24 h, the survival rate of cells was 4% +/- 4%; the effluxes of LDH and K+ were 30 +/- 3 U L-1 and 7.9 +/- 0.8 mmol L-1, respectively. All these changes were lower in Gin group than those of control. CONCLUSION: Under anoxia the cultured hippocampal neurons were seriously damaged, which may be protected by Gin.

Animals↗
PubMed1994

[Protective effect of calcitonin gene-related peptide on synaptic function in hippocampal slice during hypoxia].

Rat hippocampal slices placed in two compartments of a dual chamber were immersed in the superfusing artificial cerebrospinal fluid (ACSF) with 95% O2 + 5% CO2. The population spike (PS) and presynaptic fiber volley (PV) were recorded in CA1 pyramidal cells by stimulating Schaffer collateral pathways. Following hypoxia produced by replacing O2 with N2, the PS became gradually diminished and abolished, and in parts of the slices hypoxic injury spikes (HIP) could be observed. When 4 nmol/L beta-calcitonin gene-related peptide (beta-CGRP) -containing ACSF was superfused to the slice before and during hypoxia, the time at which PS began to decrease and got in complete abolishment were both postponed, and HIP were delayed or disappeared. After reoxygenation the recovery rate of PS was obviously higher in slices treated with CGRP than the control slices and the protective effect of CGRP was dose-dependent. In addition, superfusion of CGRP after hypoxia also increased the recovery of PS. These results indicate that (1) the time for the appearance of attenuation and disappearance of PS are varied according to the degree of hypoxia; (2) CGRP has a neuronal protective action against hypoxia.

Animals↗
PubMed1994

[Effects of interleukin-1 and interleukin-2 on electrophysiological characteristics of rat hippocampal neurons in culture].

The effects of recombinant human interleukin-1 beta (rhIL-1 beta) and interleukin-2 (rhIL-2) on the cultured rat hippocampal neurons were investigated with intracellular recording and extracellular micropressure ejection techniques. Experimental results showed that all of the neurons tested with rhIL-1 beta (100 U/ml) exhibited a 4.20 +/- 1.86 mV membrane hyperpolarization. 50% of the neurons treated with rhIL-2 (100 U/ml) showed a depolarization of 11.12 +/- 3.71 mV accompanied by bursting activity, while in a still higher concentration (1,000 U/ml) a 3.25 +/- 0.63 mV hyperpolarization was observed. All the above effects of rhIL-1 beta and rhIL-2 on the hippocampal neurons were completely reversible. The membrane resistance of the neurons was not significantly affected by these cytokines. These results suggest that the effects of cytokines IL-1 and IL-2 on the excitability of hippocampal neurons may be a way by which the immune system exerts a regulatory action on hippocampal function.

Animals↗
PubMed1992

Detection of human cytomegalovirus antigen and DNA in lymph nodes and peripheral blood mononuclear cells of patients with angioimmunoblastic lymphadenopathy with dysproteinemia.

The cause of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) remains unknown. It is characterized by acute onset, severe constitutional symptoms, cervical or generalized lymphadenopathy, lymphopenia, and polyclonal hypergammaglobulinemia, all of which are highly suggestive of a viral origin. Using immunohistochemical methods, employing murine monoclonal antibody as the primary antibody, we detected human cytomegalovirus antigen in the lymph nodes of eight of 11 patients with AILD. Cytomegalovirus DNA was also detected in the peripheral blood mononuclear cells by DNA dot hybridization in all five of the patients with AILD who were tested using this technique. None of the lymph nodes from the 11 patients stained positive for the rubella virus antigen. Based on the above evidence and the similarity of the immunologic abnormalities found in both AILD and cytomegalovirus infection, the possible role of cytomegalovirus as one of the causative agents for AILD is proposed.

Adult↗
PubMed1992

[Effects of electrical lesioning of hippocampal CA3 region and anterior commissura hippocampi fornix on plasma insulin level and islet cells in the rat].

Bilateral electrical lesioning of the hippocampal CA3 region (HCA3-EL) or anterior commissura hippocampi (ACHF-EL) caused marked elevations in plasma basal levels of insulin. 2 weeks later, fasting blood glucose levels were also augmented with decreased glucose tolerance. In contrast, the secretory response of pancreatic B cells to glucose stimulation was markedly enhanced. Following intravenous glucose tolerance test (IVGTT), the relative amounts of glucagon-like and insulin-like immunoreactants were reduced in the pancreatic islets of both HCA3-EL and ACHF-EL rats in comparison with the controls. In the HCA3-EL group, the relative amounts of somatostatin-like immunoreactants and gross numbers of such immunostained cells in islets were also decreased as compared with the control. No difference was seen in pancreatic-polypeptide-like immunoreactivities as assessed by immunohistochemistry plus microphotometry method. The above results suggest strongly that HCA3 and ACHF exert a tonic inhibitory action on the insulin secretion in the rat.

Animals↗
PubMed1992

Transcoronary chemical ablation of ventricular tachycardia.

Transcoronary chemical ablation of ventricular tachycardia was recently performed in one patient with refractory ventricular tachycardia in our hospital. The procedure was successful. The arrhythmia was cured and no recurrence occurred in a 24-month period. The clinical application and mechanism of transcoronary chemical ablation were discussed.

Adult↗
PubMed1992

Electrophysiologic follow-up in dogs receiving intracoronary ethyl alcohol injection.

96% ethyl alcohol was injected into a diagonal branch of the left anterior descending coronary artery of 10 out of 12 anesthetized dogs, and saline solution was injected in the remaining 2. After chest closure, the dogs were subjected to ambulatory monitoring (H) during days 1, 2, 3 and 7. The electrophysiologic study (EPS) and signal-averaged electrocardiography. (SA-ECG) were performed before the injection and again at day 7 after injection. H failed in one dog which died of ventricular fibrillation. In the other 9 dogs that received alcohol injection, H showed frequent ventricular premature and ventricular tachycardia (VT) after injection; six of the 9 dogs sustained VT, which was not inducible by EPS. VT was not found in 2 control dogs receiving saline solution injection. The SA-ECG showed no ventricular late potentials in dogs receiving alcohol injection. Post-ablation ventricular arrhythmia (including VT) occurred after intracoronary ethyl alcohol injection in all dogs. Arrhythmogenicity markedly declined during the first 3 days and almost completely disappeared on day 7 after ablation. There was no evidence in favor of reentry as the mechanism of these arrhythmias. Enhanced automaticity was considered as the mechanism for ventricular arrhythmia.

Animals↗
PubMed1991

Relation between acute ventricular arrhythmias, ventricular late potentials and mortality in acute myocardial infarction.

The relation between ventricular late potentials and the occurrence of acute (in-hospital) and hyperacute (before hospital admission) ventricular tachycardia or fibrillation was studied in 281 consecutive patients with uninterrupted acute myocardial infarction. The prevalence of late potentials was significantly higher in patients with than without ventricular tachycardia/fibrillation (65 vs 22%; p less than 0.01). These relations persisted among patients with left bundle branch block, although a different definition was used for identifying late potentials in these patients. Multivariate analysis showed that presence of late potentials and peak creatine kinase enzyme level were the only 2 independent variables associated with early ventricular tachycardia/fibrillation. Total in-hospital mortality, as well as in-hospital cardiac mortality, was significantly higher among patients with than without acute ventricular tachycardia/fibrillation. However, at 1 year, mortality rates did not differ between the 2 groups. The following conclusions were drawn from this study: (1) Late potentials are closely related to ventricular tachycardia/fibrillation in hyperacute and acute phases of infarction. (2) Presence of left bundle branch block does not mitigate against the finding of late potentials in these patients. (3) Early ventricular tachycardia/fibrillation in acute infarction is related to large infarctions and to a high in-hospital mortality rate.

Aged↗
PubMed1991

Delayed-type hypersensitivity antigens detected in culture supernatants of Salmonella typhimurium.

Protein antigens eliciting delayed type hypersensitivity (DTH) were analyzed and purified from the supernatants of protein-free cultures in which Salmonella typhimurium TV148 organisms had grown. DTH activity was measured by the footpad swelling test in mice immunized with living organisms of S. typhimurium TV148 or Escherichia coli K-12. DTH activity in the culture supernatant was specific to TV148-immunized mice. This activity was destroyed by pronase. DTH activity was unable to pass through an ultrafilter with an exclusion limit of 10 kD. After condensation of the supernatant and following centrifugation (100,000 g for 1 h), the DTH activities of the sediment and the supernatant were examined, and both showed DTH activity. Further analyses of DTH antigens in the supernatant by HPLC gel filtration separated the activity into three portions. The most active portion was further fractionated by hydroxyapatite HPLC, revealing the presence of two DTH antigens, with molecular weights of 65 and less than 10 kD. These results indicate that the culture supernatant of S. typhimurium TV148 organisms contains a variety of macromolecular protein DTH-eliciting antigens, and one of the antigens is 65 kD, which is dissociated partly by organic solvents into a low molecular weight (less than 10 kD) antigen.

Animals↗
PubMed1991

Transcoronary ethanol ablation of experimental ventricular tachycardia after epicardial ice mapping and localizing.

Thirty-seven reproducible ventricular tachycardias (VTs) were induced in 19 dogs after the onset of myocardial infarction. The site of origin of VT was localized in 19 (59%) of 32 VTs by ice epicardial mapping. After 0.3-1.2 ml of 95% ethanol was injected into a small coronary artery supplying the arrhythmogenic area, VT was no longer inducible in 10 of 14 dogs. Intramyocardial ethanol (1-3 ml) was injected into the site of origin of VT in 9 dogs including 4 with VTs reinduced after intracoronary ethanol. Six of these VTs were not reinduced. Thus, the total efficacy rate was 84%. In 7 dogs, after injection of 0.4-1.2 ml (mean 0.5 ml) of 95% ethanol into a small normal coronary artery, the extent of the changes in ECG, CK-MB and pathology was found to be related to the size of myocardial damage and to the dose of ethanol. The smaller the dose of ethanol was given and the more distal the branch of coronary artery into which the ethanol was injected, the smaller the myocardial damage was. The data demonstrated that intracoronary or intramyocardial injection of ethanol may ablate the experimental VT induced by programmed heart stimulation in dogs after myocardial infarction, indicating that this approach may be useful and meaningful in some selected instances. However, it is necessary to limit the myocardial damage as far as possible.

Animals↗