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Biomedical subjects

F Zhang

Publications and source records attributed to F Zhang.

At least 415 records · Page 23Linked to original sources
PubMed1997

Pulmonary artery smooth muscle cell [Ca2+]i and contraction: responses to diphenyleneiodonium and hypoxia.

To investigate mechanisms of inhibition of hypoxic pulmonary vasoconstriction (HPV), we studied pulmonary artery smooth muscle cell (PASMC) responses to hypoxia, utilizing diphenyleneiodonium (DPI), which blocks HPV. We measured cell contraction in primary cultures of rat PASMC grown on collagen gels and cytosolic free Ca2+ concentration ([Ca2+]i) in PASMC grown on glass. DPI (5 and 20 microM) caused contraction of PASMC and increased [Ca2+]i. Omission of extracellular Ca2+ diminished the DPI-induced PASMC contraction and greatly reduced the increase in [Ca2+]i. DPI substantially inhibited KCl-induced PASMC contraction (1 microM DPI) and the increase in [Ca2+]i (5 microM DPI). Severe hypoxia contracted PASMC and quadrupled [Ca2+]i. DPI, 1 microM, substantially inhibited hypoxic contraction, but neither 1 nor 5 microM DPI diminished the hypoxia-induced increase in [Ca2+]i, which was greatly attenuated by 20 microM DPI. These data show 1) that DPI increases [Ca2+]i, accounting for DPI-induced PASMC contraction and 2) that 1 and 5 microM DPI inhibit the hypoxia-induced contraction but not the hypoxia-induced increase in [Ca2+]i, suggesting that DPI inhibits hypoxic PASMC contraction downstream of the Ca2+ signal by desensitizing the contractile apparatus and indicating a potential control point for modulation of HPV.

Animals↗
PubMed1997

Role of calcium-calmodulin-dependent protein kinase II in modulation of sensorimotor synapses in Aplysia.

The Ca2+-calmodulin-dependent protein kinase II (CaMKII) inhibitor, [1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazi ne) (KN-62), was used to investigate the role of CaMKII in synaptic transmission and serotonin (5-HT)-induced facilitation in Aplysia. Application of KN-62 (10 microM) by itself increased the amplitude of excitatory postsynaptic potentials (EPSPs) at sensorimotor synapses in pleural-pedal ganglia. Moreover, in the presence of KN-62, 5-HT-induced short-term facilitation was attenuated. Application of KN-62 by itself slightly increased the duration of action potentials in isolated sensory neuron somata but did not block spike broadening produced by 5-HT. KN-62 had no effect on excitability of isolated sensory neuron somata nor did it block 5-HT-induced enhancement of excitability. These results indicate that the attenuation of short-term facilitation by KN-62 is not due to modulation of the membrane currents contributing to 5-HT-induced spike broadening or enhancement of excitability. Rather, these data are consistent with the hypothesis that CaMKII contributes to the regulation of sensorimotor connections and that it has a role in spike-duration-independent processes contributing to short-term facilitation.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1997

[Effects of both puerarin and gypsum on the firing of pyrogen-treated thermosensitive neurons in the region POAH of anesthetized cats].

To investigate the possible central mechanism of antipyretic effects of Chinese medicines, puerarin and gypsum, the firing rate of thermosensitive neurons in preoptic-anterior hypothalamus (POAH) region of 34 cats was recorded by using extracellular micro-electrode technigue. Injection of pyrogen caused decrease in firing rate of 14 warm-sensitive neurons and increase in firing rate of 11 cold-sensitive neurons in the region of POAH. The effects could be reversed by the injection of puerarin and gypsum. The results showed the antipyretic action of puerarin and gypsum might be mediated by influences on the electroactivity of pyrogen-treated thermosensitive neurons in the region of POAH. Effect of puerarin and gypsum on cold-sensitive neurons was stronger than that of single one, suggesting that both are synergic in central level.

Action Potentials↗
PubMed1997

[The usage of allograft nasal septal cartilage in partial laryngectomy].

Based on the experiment of five dogs, 22 cases of laryngeal carcinoma using allograft nasal septal cartilage as a framework for laryngeal defect after partial larygectomy are reported. After 5 years follow-up, the functions of phonation and respiration of 17 cases were satisfying and their phonatic loudness was raised remarkably. The method was used mainly for patients with T1 glottic carcinoma involving anterion commissure and selective T2, T3 glottic carcinoma. The advantages of allograft nasal septal cartilage in partial laryngectomy are discussed in comparison with auto nasal mucoseptal graft.

Aged↗
PubMed1997

[Clinical observation on juvenile-children type of Coats' disease].

OBJECTIVES: To observe the clinical features and the effects of management of juvenile-children type of Coats' disease and to approach the classification of the disease. METHODS: Fundus was examined and fundus fluorescein angiography (FFA) was made. Laser photocoagulation and cryotherapy were used for treatment. RESULTS: Compared to adult type of Coats' disease, this type was characterized by early onset, severe macular lesion, rapid progression and poor visual prognosis. The vision in 75.0% of eyes was unchanged, and in 19.2% of eyes was improved after treatment. CONCLUSIONS: Visual damage is more severe in this type. Early examination and early treatment are the key points to decrease visual deterioration. The classification of the disease is helpful in understanding the disease.

Adolescent↗
PubMed1997

A research on scalp acupuncture for cerebral infarction.

In order to evaluate the clinical value of the describes in the Standard Nomenclature of Scalp Acupuncture Lines, 105 patients suffering from cerebral infarction have been treated by needling along the anterior and posterior oblique lines of vertex-temple, and the line 1 and line 2 lateral to vertex. The markedly effective rate was 71.43%, and the total effective rate 88.57%. After treatment, such symptoms as hemiplegia, lingual dysfunction, facial and tongue paralysis, and the laboratory indexes of blood fat, fibrinogen and hemorrheology were obviously improved (P < 0.01 or 0.05). The therapeutic effect of scalp acupuncture was obviously better than that of Western medicine (P < 0.01).

Acupuncture Therapy↗
PubMed1997

Effect of acupuncture on vasoactive intestinal peptide in ischemic cerebrovascular diseases.

BACKGROUND AND PURPOSE: Vasoactive intestinal peptide (VIP) appears to play an important role as a neurotransmitter or neuromediater in ischemic cerebrovascular diseases (ICVD). The effect of acupuncture, which is used in treatment of ICVD with good efficiency, on VIP has not been known. For finding the mechanism of acupuncture in treatment of ICVD and the effect of electro-acupuncture on VIP, the present study was performed. MATERIALS AND METHODS: 59 patients with acute ICVD were randomly divided into two groups. Electro-acupuncture and routine treatment were given in Group 1 (n = 29), and routine treatment was used alone in Group 2 (n = 30). The cerebrospinal fluid (CSF) and blood were taken before the beginning of treatment and after a course of treatment in both groups. The control group consisted of 38 cases of non-ICVD. VIP was measured by radioimmunoassay. RESULTS: The level of CSF VIP in patients with acute ICVD was significantly lower than that in the controls, while the levels of plamsa VIP showed no significant difference between the ICVD and control groups, and the level of CSF VIP was not significantly correlated with the level of plasma VIP. After acupuncture treatment, the level of CSF VIP was increased and showed no significant difference as compared with the control group. CONCLUSION: Acupuncture might alleviate the disturbance of metabolism of VIP in CNS.

Acupuncture Therapy↗
PubMed1997

[The expression of rat brain constitutive nitric oxide synthase in NG108-15 cell].

Full length cDNA of rat brain cNOS was inserted into the polylinker area of pRC/CMV with specific orientation and an eukaryocyte expression vector pCMVcNOS was obtained. The existence of cNOS gene was demonstrated by PCR amplification, using pCMVcNOS gene as the model and primers designed in accord with the internal sequence of cNOS gene. The insertion and orientation of pCMVcNOS were further verified by enzymatic cleavage. NG108-15 cells were transfected with pCMVcNOS by calcium phosphate DNA coprecipitation and lipofectin transfection. G418 resistant monoclonal cells were selected with a culture medium containing 600 micrograms/ml G418. NOS activity of each clone was assayed by monitoring the conversion of 3H-Arginine to 3H-Citrulline. High expression cell lines were selected through measurement of the cytosol and particulate NOS activity. Out of 42 resistant monoclonal cell lines, 3 stable high expression clones have been finally selected. The increase of expressed cytosol NOS was more obvious. The result showed that the cell lines expressing cNOS at a high level had been obtained.

Animals↗
PubMed1997

[Treatment of liver or renal cyst by percutaneous injection of TH glue into the cyst cavities].

From April 1995 to May 1996, 32 cases of liver or renal cyts were detected by B ultra sound. Among them, TH glue was injected into the cyst to make it coagulated and occluded in 4 cases of liver cyst and 8 cases of renal cyst after intracapsular fluid was abstracted. The curative effect was good. The curative rate of single injection was 83.3%. The period of treatment and the curative rate were obviously different from the past methods. The present method is easy, quick, small wounded, few complicated and no toxic and side effects.

Adult↗
PubMed1997

Exon-by-exon screening for RB germline mutations using Heteroduplex-SSCP analysis.

OBJECTIVE: To disclose the nature of RB1 germline mutations in Chinese and to develop a practical and effective way for mutational screening. METHODS: Leukocyte DNA was prepared from 8 Chinese patients with hereditary retinoblastoma. PCR combined with nonisotopic heteroduplex-SSCP analysis was used to screen leukocyte DNA for RB1 germline mutations, exon-by-exon, without the use of restriction endonuclease digestion. The mutations were finally identified by sequencing. In order to testify the effectiveness of this method, the same method was used to detect other 17 samples which have been previously analyzed by other methods. RESULTS: Heterozygous germline mutations were detected in the leukocyte DNA of 6 out of 8 Chinese patients: G del/codon 46, T del/codon 131, CAGAA del/codon 257-258, GCAgta-->GCAgca/donor of exon 16, C-->T/codon 661, and C-->T/codon 787. Heteroduplex-SSCP analysis may detect RB1 germline mutations in 68% (17/25) unselected patients, which is more effective than SSCP(56%) or heteroduplex analysis(64%) alone. The corrected RB1 mutation detection rate may be 80% if the samples were previously analyzed by Southern blotting, which is much higher than those reported on literature. CONCLUSION: Mutations involving a few base pairs in RB1 gene are common in Chinese. Heteroduplex-SSCP analysis is more useful and effective than SSCP or heteroduplex analysis alone for the rapid screening for unknown mutations.

Female↗
PubMed1997

[An analysis of dynamic ECG of 36 pilots].

24h dynamic electrocardiogram (DCG) of 36 healthy male fighter pilots, aged 25-35 years were recorded and analysed, then the data were compared with DCG of 55 normal subjects. The results showed that supraventricular arrythmias were more than ventricularones; both supraventricular and ventricular arrythmias of pilots were more than that of the control; the appearing rate of ST setment depression of pilots was higher.

Adult↗
PubMed1997

Analysis of heart rate variability and its application.

Heart rate variability (HRV) has considerable potentials in assessing the role of autonomic nervous system fluctuations in healthy individuals and patients. This paper reviews the analytical methods of HRV and its application. HRV is a useful parameter for predicting cardiac risk after acute myocardial infarction, and an early warning sign of diabetes neuropath in clinical medicine. In space medical studies, HRV analysis have been used to assess changes in autonomic regulation after weightlessness or simulated weightlessness, evaluate tolerance in various stress test, study regulatory mechanisms of cardiovascular system, and assess the effect of countermeasure against weightlessness.

Aerospace Medicine↗
PubMed1997

[Detection of hepatitis G virus RNA in sera in non A-E hepatitis patients using polymerase chain reaction with multiple set primers].

A double polymerase chain reaction, involoving nested primers deduced from NS3-5 regions of the hepatitis G virus (GBV-c/HGV) genome, was developed for a sensitive and specific detection of GBV-C (HGV) RNA. With this method, 10 anti-HGV positive patients with non A-E hepatitis and 10 healthy subjects were tested. Among 10 patients, GBV-C RNA was detected in 9, 8, 4, 9 patients by the NS-3 (1) primers, the NS3(2) primers, the NS4 primers, the NS5(1) primers and the NS5(2) primers respectively. Control sera from 10 healthy subjects did not reveal GBV-C (HGV) RNA by any set of the primers. These data suggest that the detection rate of GBV-C (HGV) RNA is different in various set of primers, the NS3(1) and the NS5(2) primers are superior to other primers and are more suitable for RT-PCR of GBV-C (HGV) RNA.

DNA Primers↗
PubMed1997

[Serum G-CSF levels in patients with chronic aplastic anemia].

OBJECTIVE: To explore the pathogenesis of aplastic anemia. METHODS: The spleen cells of BALB/c miceimmunized with rhG-CSF were fused with myeloma cell line SP2/0. Three murine hybridomas producing monoclonal antibody (McAb) against rhG-CSF were obtained. Serum levels of G-CSF in 54 cases of chronic aplastic anemia (CAA) were detected by ELISA method. RESULTS: Serum G-CSF levels in 70.4% (38 of 54 cases) of the CAA patients were increased (272.76 +/- 58.39ng/L). There was a negative correlation between blood neutrophil counts and serum G-CSF levels (r = -0.535, P<0.01). CFU-GM were detected in 12 cases of CAA, and all was decreased (17.92 +/- 10.28/2 x 10(5) nucleated cell). Serum G-CSF levels in almost 30% (12 of 54 cases) of the CAA patients were not increased. CONCLUSION: The hematopoietic progenitor cells of CAA patients were impaired, and some CAA could be treated with rhG-CSF and immunosuppressive agents.

Adult↗
PubMed1997

[Study of antisense oligodeoxynucleotide in reversing multidrug resistance and inducing apoptosis of tumor cells].

OBJECTIVE: T o explore an approach to the reversal of multidrug resistance(MDR) of tumor cells. METHODS: Antisense oligodeoxynucleotide (mdr-1-AS PS-ODN) was used. RESULTS: A large amount of DNA fragments was found in mdr-1-AS PS-ODN treated K562/ADM cells and almost all the mdr-1+ K562/ADM cells underwent apoptosis. CONCLUSION: mdr-1-AS PS-ODN could inhibit specifically mdr-1 gene expression, effectively reverse MDR of the tumor cells and promote ADM induced apoptosis of mdr-1+ K562/ADM.

Apoptosis↗
PubMed1997

Canine lung transplantation after more than twenty-four hours of normothermic preservation.

BACKGROUND: Consistent clinical results have not been achieved when lung preservation times exceed 6 hours. The aim of this study was to use an alternative normothermic autoperfusion technique for lung preservation and transplantation. METHODS: In six paired dogs, donor lungs were removed, along with the heart, liver, pancreas, duodenum, and both kidneys, and were preserved for 24 to 33 hours in a normothermic autoperfused multiple organ block. Orthotopic left lung transplantation was performed at the end of the preservation period. RESULTS: Lung function was good during the preservation period. With a gas mixture of 50% O2 + 3% CO2 + 47% N2 delivered to the multiorgan block, arterial oxygen tension ranged from 331 +/- 19 to 383 +/- 8 mm Hg; carbon dioxide tension ranged from 18 +/- 5 to 32 +/- 5 mm Hg; and pH ranged from 7.36 +/- 0.02 to 7.45 +/- 0.08. After transplantation, the dogs were kept anesthetized and ventilated for 24 hours with the same gas mixture. The opposite pulmonary artery was occluded 0 to 6 hours after transplantation. Arterial blood pressures were stable after surgery. Arterial oxygen tension was maintained between 205 +/- 39 and 320 +/- 57 mm Hg, and arterial carbon dioxide tension was maintained between 23 +/- 2 and 34 +/- 2 mm Hg. Lung tissue wet/dry weight ratio was 4.94 +/- 0.17 after preservation; this ratio did not differ from that found in normal controls (4.91 +/- 0.10). CONCLUSIONS: This study shows that the lungs were well preserved for more than 24 hours of preservation when the normothermic multiorgan block preparation was used. The transplanted left lung was able to support the anesthetized dog after the opposite pulmonary artery was occluded.

Animals↗