Search PubMed⌕ Search

Biomedical subjects

W Jiang

Publications and source records attributed to W Jiang.

At least 199 records · Page 11Linked to original sources
PubMed1998

[Influence of fry-processing on outward character and inner quality of volatile oil containing drugs such as fructus Viticis, etc].

According to the requirement of outward character in processing traditional Chinese drugs, five volatile oil containing drugs Fructus Viticis, Rhizoma Atractylodis Macrocephalae, Rhizoma Cyperi, Fructus Foeniculi and Fructus Aurantii were fry-processed. The conditions of frying technology were measured; the amounts of volatile oil before and after processing were determined with accurate volatile oil extractor; and the volatile oil in Rhizoma Atractylodis Macrocephalae and Fructus Aurantii was analyzed by means of GC.

Apiaceae↗
PubMed1998

[Changes in distortion product otoacoustic emissions and hair cells after noise exposure in guinea pigs].

In order to observe the changes in distortion product otoacoustic emissions (DPOAE) and hair cells after noise exposure, sixteen healthy guinea pigs were used. The animals were divided into 3 groups. Group 1 was normal animals. Group 2 and 3 were animal right and 7 days after exposed to 115 dB SPL simulated submarine engine room noise for 4 hours, respectively. The DPOAE audiogram and I/O function were measured before and after exposure. The changes of hair cells were observed by light microscope and scanning electron microscope. The amplitudes of DPOAE disappeared right after noise exposure(P < 0.01) and recovered to normal at 7 days after exposure (P > 0.05). The light microscopy and scanning electron microscopy showed the stereocilia of the outer hair cells were disarrangement and some disappeared at 2,3,4 kHz regions of the cochlea. The results indicated that the normal outer cells can regulate and compensate the function of some damaged outer hair cells which result in a normal DPOAE in mild damaged cochlea.

Animals↗
PubMed1998

[Efficacy of regimens containing INH, RFP with varied chemotherapy courses on retreated culture positive pneumoconio-tuberculosis].

OBJECTIVE: To evaluate the short and long-term effects of regimens containing INH, RFP with varied chemotherapy courses on culture-positive pneumoconio-tuberculosis. METHOD: 79 patients with culture-positive pneumoconio-tuberculosis were divided into three groups according to chemotherapy duration: 9-months group (M9: 2SHRZ/7HRE) 28 cases, 12-month group (2SHRZ/10HRE) 25 cases, 18-month group (M18: 2SHRZ/10HRE/6HR) 26 cases. Evaluating the efficacy of regimens depended predominantly on sputum bacteriological conversion, and the patients who completed the regimens were followed up for 5-8 years. RESULT: Sputum negative conversion rates of three groups at the end of chemotherapy were 83%, 96%, 95%, and their recurrent rates in follow-up period 41%, 4% and 5% respectively. Of all patients who completed the regimens bacteriological relapse rates from the first to fourth year are 6%, 8%, 2%, 2% in the follow-up period. There was no bacteriological relapse from fifth to eighth year. CONCLUSION: It is effective for SHRZ/HRE combination with 12-months course to retreated tubercle bacillus positive pneumoconio-tuberculosis, and it is appropriate for such patients to be followed up for 4-5 years.

Aged↗
PubMed1998

[p53 gene mutation in hepatocellular carcinoma].

OBJECTIVE: To study the relationship between mutation of p53 gene and hepatocellular carcinoma (HCC). METHOD: Sixty-five cases of HCC from Nanning prefecture of high aflatoxin (AFB1) exposure were studied by polymerase chain reaction and restrictive fragment length polymorphism (PCR-RFLP) analysis to examine the exon 7 of p53 gene in HCC. RESULT: 58.5% of the cases were found to show mutation at codon 249 of p53 gene; 63.6% for the HCCs with HBsAg negative, and 57.4% for those with HBsAg positive; 88.9% for those with metastasis, and 46.8% for those with no metastasis. The mutation rate of p53 gene was 10.0%, 55.2% and 80.8% in the well-, moderately- and poorly-differentiated HCC respectively. CONCLUSION: AFB1 is the most important agent for the mutation at the hot-spot, and hepatitis B virus is the synergistic risk factor. Further study indicated that the p53 gene mutation is correlated with the differentiation and the metastasis of HCC and may serve as an important prognostic factor.

Aflatoxin B1↗
PubMed1998

[Bone scintigraphy in evaluating revascularization of the heat-devitalised autografts in adult dogs].

OBJECTIVE: To establish an animal model of microwave hyperthermic devitalization of long bones and compare bone scintigraphy of the devitalised bone with pathologic examination. METHOD: 16 Mongrel adult dogs were used. Enght 8 cm of one femur of each dog was exposed and isolated by heat-proof material. Two microwave antennas were inserted into the medullary cavity at a distance of 2.5 cm, and the bone was heated intermittently to maintain a surface temperature of 50 degrees C to 60 degrees C for 30 minutes. Bone scintigraphy was carried out at different postoperative time, combined with tetracycline labeling, microangiography with Indian ink and HE staining. RESULT: About 5 cm - 6 cm of segmental femur was deprived of blood supply after devitalization which was confirmed by microangiography and negative labeling of tetracyclines. At two weeks, the devitalised bone demonstrated a cold region on the scintiscan and no revascularization in microangiography. 12 - 16 weeks after the operation, partial devitalised bone was revascularized and HE staining showed widel bone resorption and minimum formation of new bone. However, the radionuclide uptakes of the devitalised segments were greater than those of the normal femurs. At one year, the devitalised segment was well (not completely) revascularised and showed evident appositional new bone formation. The scintigraphic bone-imaging was slightly lower than that of the normal femur. CONCLUSION: A strong positive scintiscan in early stage might demonstrate a good potential of revascularization of the heat-devitalised cortical bone rather than its viability. And the scintiscans of long-term follow-up more than one year should be more informative.

Angiography↗
PubMed1998

[A study of non-steady flow properties in flow chamber experiment].

A time-dependent velocity equation has been achieved by means of eigenfunction method in this paper, which can satisfy any impetus and describe the changing process from the initial time to any time. The theoretical basis is provided to study the nature of blood cells in non-steady flow.

Nonlinear Dynamics↗
PubMed1998

Cdc2-mediated phosphorylation of the gap junction protein, connexin43, during mitosis.

As cells enter mitosis, gap junctional communication with neighboring cells decreases (H. Xie et al., J. Cell Biol., 137: 203-210, 1997). Phosphorylation of the gap junction protein, connexin43 (Cx43), has been implicated in reducing junctional permeability. Cx43 contains p34cdc2 phosphorylation consensus sites in its COOH-terminal region. Accordingly, we examined the role of p34cdc2/cyclin B in Cx43 phosphorylation. Purified p34cdc2/cyclin B, or p34cdc2/cyclin B complex immunoprecipitated from mitotic cells, phosphorylated GSTCx43 in vitro. The synthetic peptide, SDPYHATTGPLSPSKDCGSPK, corresponding to amino acids 241-264 of Cx43, was also phosphorylated by p34cdc2/cyclin B in vitro. Sites phosphorylated in vitro were phosphorylated in vivo. Butyrolactone I, an inhibitor of cdc2 kinase, inhibited increases in Cx43 phosphorylation during mitosis. We conclude that phosphorylation of Cx43 by p34cdc2/cyclin B may contribute to the increased Cx43 phosphorylation and reduced gap junctional communication observed during mitosis.

4-Butyrolactone↗
PubMed1997

Identification and characterization of a human protein kinase related to budding yeast Cdc7p.

The Cdc7p protein kinase is essential for the G1/S transition and initiation of DNA replication during the cell division cycle in Saccharomyces cerevisiae. Cdc7p appears to be an evolutionarily conserved protein, since a homolog Hsk1 has been isolated from Schizosaccharomyces pombe. Here, we report the isolation of a human cDNA, HsCdc7, whose product is closely related in sequence to Cdc7p and Hsk1. The HsCdc7 cDNA encodes a protein of 574 amino acids with predicted size of 64 kDa. HsCdc7 contains the conserved subdomains common to all protein-serine/threonine kinases and three "kinase inserts" that are characteristic of Cdc7p and Hsk1. Immune complexes of HsCdc7 from cell lysates were able to phosphorylate histone H1 in vitro. Indirect immunofluorescence staining demonstrated that HsCdc7 protein was predominantly localized in the nucleus. Although the expression levels of HsCdc7 appeared to be constant throughout the cell cycle, the protein kinase activity of HsCdc7 increased during S phase of the cell cycle at approximately the same time as that of Cdk2. These results, together with the functions of Cdc7p in yeast, suggest that HsCdc7 may phosphorylate critical substrate(s) that regulate the G1/S phase transition and/or DNA replication in mammalian cells.

Amino Acid Sequence↗
PubMed1997

Decreased Stability of Transforming Growth Factor beta Type II Receptor mRNA in RER+ Human Colon Carcinoma Cells

Transforming growth factor beta (TGF-beta) is a potent inhibitor of cell growth and tumor progression. Previous work has shown that loss of functional TGF-beta type II receptor (RII) due to a frameshift mutation in the 5' half of the RII gene leads to TGF-beta resistance in a highly progressed, RER+ human colon carcinoma cell line designated HCT116. Expression of this mutated RII gene was highly repressed in RER+ cell lines such as HCT116 and RKO, as analyzed by RNase protection assays. Nuclear run-on and RII promoter-reporter (CAT) assays showed that the transcriptional levels of the RII gene in these RER+ cells were not reduced, compared to RII-expressing cells. However, the half-lives of the RII mRNA, as analyzed by RNase protection assays following actinomycin D treatment, were significantly decreased. This suggested that the decreased expression of the RII gene mutant was due to decreased mRNA stability. Furthermore, RII mRNA from HCT116 transfected with wild-type RII had a longer half-life than the endogenous mutated RII mRNA. A dominant negative RII mutant, which encodes a similarly truncated RII protein as HCT116 but lacks the extensive 3' untranslated region of RII mRNA, gave the same half-life as endogenous wild-type RII mRNA. We conclude that the frameshift mutation which results in a premature stop codon in the 5' half of the mRNA transcript accounts for the reduced RII mRNA levels in RER+ cells.

Journal Article↗
PubMed1997

Stress management and exercise training in cardiac patients with myocardial ischemia. Effects on prognosis and evaluation of mechanisms.

BACKGROUND: Previous studies have demonstrated that myocardial ischemia can be elicited by mental stress in the laboratory and during daily life and that ischemia induced by mental stress is associated with an increased risk for future cardiac events in patients with coronary artery disease. OBJECTIVES: To examine the extent to which ischemia induced by mental stress can be modified by exercise stress management, and to evaluate the impact of these interventions on clinical outcomes. METHODS: One hundred seven patients with coronary artery disease and ischemia documented during mental stress testing or ambulatory electrocardiographic monitoring were randomly assigned to a 4-month program of exercise or stress management training. Patients living at a distance from the facility formed a nonrandom, usual care comparison group. Myocardial ischemia was reassessed following treatment, and patients were contacted annually for as long as 5 years to document cardiac events, including death, nonfatal myocardial infarction, and cardiac revascularization procedures. RESULTS: Twenty-two patients (21%) experienced at least 1 cardiac event during a mean (+/- SD) follow-up period of 38 +/- 17 months. Stress management was associated with a relative risk of 0.26 compared with controls. The relative risk for the exercise group also was lower than that of controls, but the effect did not reach statistical significance. Stress management also was associated with reduced ischemia induced by mental stress and ambulatory ischemia. CONCLUSION: These data suggest that behavioral interventions offer additional benefit over and above usual medical care in cardiac patients with evidence of myocardial ischemia.

Adult↗
PubMed1997

Effects of cyclin D1 overexpression on G1 progression-related events.

In previous studies (W. Jiang, S. M. Kahn, P. Zhou, Y. (J. Zhang, A. M. Cacace, A. S. Infance, Y. Doi, R. M. Santella, and I. B. Weinstein 1993, Oncogene 8, 3447-3457) we reported that stable overexpression of cyclin D1 in R6 rat embryo fibroblasts shortens the G1 phase and impairs growth control. In the present study we examined the effects of cyclin D1 overexpression on other events involved in the G1 to S progression, utilizing the overexpressor cell line R6-ccnD1. We found that when compared to R6 control cells, serum-starved quiescent R6-ccnD1 cells had not only increased levels of the cyclin D1 protein but also increased levels of the cyclin E protein. The latter protein was complexed to phosphorylated cyclin-dependent kinase 2 (CDK2). However, in quiescent serum-starved R6-ccnD1 cells this cyclin E-CKD2 complex lacked in vitro kinase activity due to the presence of a heat-stable inhibitory activity, apparently reflecting the inhibitory effects of the CDK inhibitors (CDKIs) p21WAF1 and p27KIP1. Serum stimulation of the quiescent R6-ccnD1 cells was associated with a loss of this inhibitory activity and a decrease in the levels of the latter two proteins, as the cells progressed through the G1 phase. On the other hand, serum stimulation of the control R6 cells was associated with both induction of cyclin E and increased levels of phosphorylated CDK2 proteins and decreased levels of p21WAF1 and p27KIP1, as the cells progressed through the G1 phase. Thus, even though overexpression of cyclin D1 can induce the expression of cyclin E and phosphorylated CDK2, premature activation of cyclin E-CDK2 kinase activity in quiescent cells or during progression through G1 appears to be blocked by CDKIs. Nevertheless, the R6ccnD1 cells have a shorter G1 phase than the control cells presumably due to the high levels of both cyclin D1 and cyclin E. Taken together, these results indicate that overexpression of cyclin D, which is frequently seen in human tumors, can have complex effects on the expression of other genes that control cell cycle progression.

Animals↗
PubMed1997

Ability of heart rate variability to predict prognosis in patients with advanced congestive heart failure.

We analyzed heart rate variability from normal RR intervals in patients with advanced congestive heart failure. Although most patients had decreased HRV, patients with a life-threatening cardiac event or death (n = 8) within 18 months had significantly lower heart rate variability than those who did not (n = 18), which may have value in determining prognosis in this population.

Adult↗
PubMed1997

Neurodegeneration in Lurcher mice caused by mutation in delta2 glutamate receptor gene.

Lurcher (Lc) is a spontaneous, semidominant mouse neurological mutation. Heterozygous Lurcher mice (Lc/+) display ataxia as a result of a selective, cell-autonomous and apoptotic death of cerebellar Purkinje cells during postnatal development. Homozygous Lurcher mice (Lc/Lc) die shortly after birth because of a massive loss of mid- and hindbrain neurons during late embryogenesis. We have used positional cloning to identify the mutations responsible for neurodegeneration in two independent Lc alleles as G-to-A transitions that change a highly conserved alanine to a threonine residue in transmembrane domain III of the mouse delta2 glutamate receptor gene (GluR delta2). Lc/+ Purkinje cells have a very high membrane conductance and a depolarized resting potential, indicating the presence of a large, constitutive inward current. Expression of the mutant GluR delta2(Lc) protein in Xenopus oocytes confirmed these results, demonstrating that Lc is inherited as a neurodegenerative disorder resulting from a gain-of-function mutation in a glutamate receptor gene. Thus the activation of apoptotic neuronal death in Lurcher mice may provide a physiologically relevant model for excitotoxic cell death.

Amino Acid Sequence↗
PubMed1997

Nitric oxide-mediated apoptosis of K-1735 melanoma cells is associated with downregulation of Bcl-2.

Recent studies have shown that the treatment of nonmetastatic K-1735 murine melanoma cells with cytokines induces the production of nitric oxide (NO) and hence cell death. The purpose of this study was to determine the mechanism of this cytokine-induced NO-mediated apoptosis. Incubation of nonmetastatic K-1735 cells with interleukin-1 alpha (IL-1alpha) and interferon-gamma (IFN-gamma) induced high NO production, Bcl-2 downregulation, and apoptotic cell death. In contrast, incubation of metastatic K-1735 cells with IL-1alpha and IFN-gamma did not induce significant production of NO, downregulation of Bcl-2, or cell death. The exposure to exogenous NO derived from the NO donors, sodium nitroprusside (SNP), or GEA5024 produced a dose-dependent apoptotic cell death in both the metastatic and nonmetastatic K-1735 cells, which was associated with downregulation of Bcl-2 at the mRNA level and, to a lesser extent, at the protein level. Nonmetastatic and metastatic K-1735 cells transfected with the Bcl-2 gene were more resistant to apoptosis mediated by both endogenous and exogenous NO. Subsequent to intravenous injection, the tumor cells transfected with the Bcl-2 gene had an increased survival rate in the lungs of nude mice and produced a higher number of experimental lung metastases. These data suggest that NO-induced apoptosis in K-1735 melanoma cells is associated with downregulation of Bcl-2.

Animals↗
PubMed1997

Effects of mental stress on myocardial ischemia during daily life.

OBJECTIVE: To determine the relative risk of myocardial ischemia triggered by specific emotions during daily life. DESIGN AND SETTING: Relative risk was calculated by the recently developed case-crossover method, in which the frequency of a presumed trigger during nonischemic, or control, hours is compared with the trigger's frequency during ischemic, or case, hours. Outpatients at Duke University Medical Center, Durham, NC, underwent 48 hours of ambulatory electrocardiographic (ECG) monitoring with concurrent self-report measures of activities and emotions. Occurrences of negative emotions in the hour before the onset of myocardial ischemia were compared with their usual frequency based on all hours in which ischemia did not occur. SUBJECTS: From a sample of 132 patients with coronary artery disease and recent evidence of exercise-induced ischemia who underwent 48 hours of ambulatory ECG monitoring, 58 patients exhibited ambulatory ischemia and were included in the analysis. OUTCOME MEASURES: Myocardial ischemia during 48-hour ECG monitoring was defined as horizontal or downsloping ST-segment depression of 1 mm (0.1 mV) or more for 1 minute or longer compared with resting baseline. The ECG data were cross-tabulated with subjects' concurrent diary ratings of 3 negative emotions-tension, sadness, and frustration-and 2 positive emotions-happiness and feeling in contro-on a 5-point scale of intensity. RESULTS: The unadjusted relative risk of occurrence of myocardial ischemia in the hour following high levels of negative emotions was 3.0 (95% confidence interval [CI], 1.5-5.9; P<.01) for tension, 2.9 (95% CI, 1.0-8.0; P<.05) for sadness, and 2.6 (95% CI, 1.3-5.1; P<.01) for frustration. The corresponding risk ratios adjusted for physical activity and time of day were 2.2 (95% CI, 1.1 -4.5; P<.05) for tension, 2.2 (95% CI, 0.7-6.4; P=.16) for sadness, and 2.2 (95% CI, 1.1-4.3; P<.05) for frustration. CONCLUSIONS: Mental stress during daily life, including reported feelings of tension, frustration, and sadness, can more than double the risk of myocardial ischemia in the subsequent hour. The clinical significance of mental stress-induced ischemia during daily life needs to be further evaluated.

Activities of Daily Living↗