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Biomedical subjects

C Wang

Publications and source records attributed to C Wang.

At least 397 records · Page 22Linked to original sources
PubMed2000

Relationship between p53 gene mutation and protein expression: clinical significance in transitional cell carcinoma of the bladder.

Although the mutated p53 gene has been postulated to induce immunohistochemically-detectable p53 protein, reports regarding the relationship between p53 mutation and p53 protein expression have been contradictory. This study investigated the relationship between p53 mutations and p53 expression and their clinical significance for patients with transitional cell carcinoma of the bladder. Eighty-seven transitional cell carcinoma of the bladder were analyzed by immunohistochemistry (IHC) for p53 nuclear accumulation, and the results compared to mutations detected in the p53 gene evaluated by polymerase chain reaction single-strand conformation polymorphism (SSCP) and DNA sequence analysis. By p53 IHC analysis, positive p53 staining was observed in 50 (57.5%) of the 87 tumors. The specificity of IHC, defined as a percentage of IHC negative (<20%) tumors among tumors without mutation, was 94.6%. Despite the good concordance between p53 mutation and p53 protein expression (p<0.0001), 48.0% (24/50) of the tumors showed p53 overexpression without mutation, and 2 (5.4%) tumors with mutation showed no p53 immunoreactivity. Patients with higher grade (grade 3), stage (stages pT2-4), and p53 mutations had a poorer prognosis by Kaplan-Meier survival analysis. A Cox univariate analysis found that grading (hazard ratio 3.139; p=0.002), staging (hazard ratio 3.832; p=0.0005) and p53 mutation (hazard ratio 2.498; p=0.013) were significant variables in these patients, but no variable was independently associated with an increased survival of bladder carcinoma by multivariate analysis. We found that a 20% cut-off level of p53 overexpression showed the highest correlation with prognosis and p53 mutation, however, p53 overexpression and mutation were not superior to staging as prognostic markers. These data suggest that careful assessment of the TNM staging system remains the most reliable predictive indicator of survival for patients with transitional cell carcinoma of the bladder.

Adult↗
PubMed2000

[Analysis of chromosomal karyotypes in 300 fetal blood samples during the second and third trimesters of gestation].

OBJECTIVE: To analyze the fetal chromosomal karyotypes from the blood samples obtained by cordocenteses during the second and third trimesters, and to investigate the types of chromosomal abnormalities, as well as the relationship between the abnormal karyotypes and the indications of prenatal diagnosis. METHODS: Cordocenteses were performed in 300 pregnant women with different indications for prenatal diagnosis during the 18 to 38 gestational weeks, and fetal chromosomal karyotypes were examined. RESULTS: Twenty three chromosomal abnormalities(7.7%) were checked out. In the second trimester, there were 15 abnormalities in 174 samples(8. 6%); whereas in the third trimester, it was 8 out of 126(6.3%), P=0. 77. Trisomy, the leading abnormality, consisted of 60.9%(14/23) of all abnormalities and 9 out of 14 were trisomy 21, which was 39. 1%(9/23). In those aged over 35 years, trisomy 21 was detected in 5 of 92(5.4%), and in the age under 35 years, it was 4 out of 208(1. 9%), P=0.26. Thirty three women had the history of giving a birth of trisomy 21 previously, this time, however, no one was recurrent. Highest chromosomal aberration rate, 26.3%(5/19), was detected in the fetuses with intrauterine growth retardation(IUGR), and all were trisomy. Balanced translocation was found in 5 fetuses (1 associated with Robertsonian translocation), which was 21.7%(5/23). CONCLUSION: During the second and third trimesters, the rate of chromosomal abnormality is 7.7% in those fetuses who have maternal indications for prenatal diagnosis. trisomy, especially trisomy 21, is the most common abnormal karyotype found in these periods and in advanced maternal age, as well as in severe IUGR.

Adult↗
PubMed2000

Mechanisms of N-methyl-D-aspartate-induced apoptosis in phencyclidine-treated cultured forebrain neurons.

Chronic administration of phencyclidine (PCP) to rats has been demonstrated to produce a sensitized locomotor response to PCP challenge that is associated with apoptotic cell death and an up-regulation of the N-methyl-D-aspartate (NMDA) receptor. To determine the underlying mechanisms, dissociated forebrain cultures were treated for 2 days with 3 microM PCP. After washout of PCP, NMDA was added (in the presence of Mg(2+)) for 20 h. The uptake of a vital dye and the release of lactate dehydrogenase measured cell viability. Apoptosis was assessed by an enzyme-linked immunosorbent assay that was specific for fragmented (histone-associated) DNA and an in situ assay for nicked DNA, terminal dUTP nick-end labeling. These assays showed that the effect of a nontoxic concentration of NMDA (30 microM) became lethal to approximately one-third of the neurons after chronic (48-h) PCP treatment. This treatment also resulted in a 47% increase in NR1 subunit mRNA, suggesting that NMDA-induced neuronal cell death after chronic PCP is due to NMDA receptor up-regulation. Furthermore, exposure of PCP-treated cultures to NMDA led to increased expression of Bax and decreased expression of Bcl-X(L). The Bcl-X(L)/Bax ratio was markedly decreased by 30 microM NMDA in the PCP-treated, but not control, cultures. Addition of superoxide dismutase and catalase prevented the decrease in Bcl-X(L)/Bax. This study suggests that NMDA-induced changes in Bax and/or Bcl-X(L) involve the formation of reactive oxygen species. By extrapolation, these data suggest that PCP-induced apoptosis in vivo may involve similar mechanisms and that cultured neurons may be a suitable model for the mechanistic study PCP toxicity in vivo.

Animals↗
PubMed2000

Determining functions of multiple phospholipase Ds in stress response of Arabidopsis.

Phospholipase D (PLD) is encoded by a multiple gene family, and several PLDs from Arabidopsis have been characterized at the molecular biological and biochemical levels. PLDalpha is the most abundant plant PLD and exhibits a number of different biochemical properties to the other isoforms. The other PLDs have many overlapping catalytic properties but display some unique patterns of expression during development and in response to stress cues. Accumulating data indicate that different PLDs have multiple and different roles in plant responses to stress.

Abscisic Acid↗
PubMed2000

[The construction and physical-mechanical characterization of polymer foams of D. L-PLA].

This study was intended to construct biogradable polymer foam used in tissue engineering. The D. L-PLA was supplied by chengdu institute of organic chemistry. Biogradable polymer membranes were prepared with a novel solvent-casting particulate-leaching technique, then, the constituent membranes with the proper order were laminated to produce three-dimensional foams with continuous pore structure and morphology. Afterwards, the physical-mechanical property of polymer foams were tested. The test results indicated that the lamination process did not change the physical-mechanical property of the polymer membranes.

Biocompatible Materials↗
PubMed2000

[Determination of fructose-1,6-diphosphate with aldolase-DNPH by the colorimetric method].

This paper presents a modified method of enzymatic assay for Fructose-1,6-diphosphate(FDP). FDP is split to dihydroxyacetone phosphate (DAP) and glyceraldehyde-3-phosphate (GAP) by the action of aldolase. DAP is hydrolyzed at room temperature to free triose. Under alkaline conditions, the free triose is reacted with 2,4-dinitrophenylhydrazine (DNPH), yielding a 2,4-dinitrophenylhydrazine derivative which dissolve in alkali forming a purple color mixture, with maximum absorption at 540.nm. It is proportional to the contents of FDP. Because the method depends on the colorimetric determination of triose formed from fructose-1,6-diphosphate only by aldolase, glycerophosphate dehydrogenase/triosephosphate isomerase (GDH/TIM) and reduced nicotinamide adenine dinucleotide (NADH) which usually applied in multienzymatic method, are omitted in the modified method. The method is specific, convenient and accuracy for the determination of FDP.

Colorimetry↗
PubMed2000

[Summary of 42 patients with acute aortic occlusion].

OBJECTIVE: To summarize the experience of diagnosis and treatment in 42 patients with acute aortic occlusion. METHODS: Clinic data were analyzed. The emergency surgery of retrograde catheter thrombolectomy of transaortic thromboembolism were done, and the propathy and complications were treated simultaneously. RESULTS: Normal blood flow were restored just after operation. Four patients died of myonephropathic metabolic syndrome and heart failure. 38 patients were followed up for 0.5 to 4 years. Among them, 36 were followed for more than 1 year. A better effectiveness was achieved in 28 patients. Two patients died of recurrence accompanied with heart failure. CONCLUSION: Early diagnosis and treatment may increase the curative ratio and decrease the mortality in patients with acute aortic occlusion.

Acute Disease↗
PubMed2000

[Study of ADRV antibody persistence in the serum of ADRV positive cases].

OBJECTIVE: This research aimed at observing the persistent time of ADRV antibody in the sera of ADRV cases. METHODS: We adopted a sensitive and specific Enzyme-linked immunosorbent assay (ELISA) for detecting ADRV antibody in patients who had recovered. RESULTS: We tested 260 human sera from Yi-Ma town of Henan Province. One year, six years and ten years after the patients had recovered, the of positive rates for ADRV antibody were respectively 27.7%, 36.3% and 23.3%. Thirty subjects of ADRV antibody positive were followed up retrospectively, no recurrent diarrhea was found. CONCLUSIONS: The ADRV antibody can last 16 years after primary infection.

Adult↗
PubMed2000

[Seroepidemiology of adult diarrhea rotavirus in some countries of Asia].

OBJECTIVE: Adult diarrhea rotavirus (ADRV) is the major cause of severe adult diarrhea. This paper is to survey the ADRV antibody in sera of normal persons of some areas of Asia including China cities of Changchun, Nanking, Taiyuan, Wuhan, Kathmandu of Nepal, Seoul of South Korea and Hong Kong China. METHODS: The ADRV antibody was detected by enzyme-linked immunosorbent blocking test. RESULTS: The data of survey showed that 1. A total detection of 2183 normal sera from persons of Asian areas showed an ADRV antibody positive rate of 3.6% (79/2183); 2. In cities in China and in Hong Kong, the ADRV antibody showed a lower level in age groups of 10-20,20-30-; 3. The ADRV antibody was detectable in normal persons in 1997 in Hong Kong which indicated an earlier existence of ADRV there before the ADRV outbreak in mainland China in 1983; 4. The ADRV antibody level observed in 1986-1991 in Hong Kong showed no obvious difference; 5. ADRV antibody was detectable in normal persons in Nepal and South Korea. CONCLUSIONS: The survey showed there was only a low level of ADRV antibody in normal persons in the Asian areas surveyed.

Adolescent↗
PubMed2000

[Individual biomass of natural Pinus densiflora].

The aboveground biomass of individuals with different growth potentials in natural Pinus densiflora forest with different stand densities was measured in Yanbian, Jilin Province. The variation of individual biomass affected by densities was in order of dominant tree < intermediate tree < suppressed tree, while the distribution proportion of biomass in different organs affected by densities was: in order of trunk > branch > needle > bark. The biomass components of P. densifliora with different growth potentials varied markedly with the approaching of density class III, and the change of intermediate trees was similar to the whole stand. The vertical distributions of biomass of different trees were different from each other, but all showed that the biomass of trunks and barks was mainly distributed below 6 m high from ground, that of branches was within 6-10 m high, that of needles was uniform in the upper, middle and lower layers, and that of branches and needles in upper layer was least affected by density.

Biomass↗
PubMed2000

Chinese-made electrolytic detachable coil in the embolization of a dog aneurysmal model.

OBJECTIVE: To develop a Chinese-made electrolytic detachable coil (CEDC) that would allow patients to enjoy the benefit of electrolytic detachable coil without having to rely on the expensive Guglielmi detachable coil (GDC), and to test the safety and efficiency of CEDC. METHODS: Radiopacity of the marker of the CEDC was tested. The anti-strain force of coils and connection points were measured. In vitro and in vivo electrolyses were conducted. We produced 21 aneurysm models including lateral, bifurcation, and terminal aneurysm models, and embolized 18 models with CEDC. RESULTS: Radiopacity of the marker was satisfactory. Anti-strain of the coil and the connection point have shown the safety and efficiency of CEDC. Electrolysis in vitro and vivo, was similar to that of GDC. 83% of the aneurysm models were completely occluded. Coils were found to induce thrombosis in the aneurysm cavity, and could lead to a new endothelium over the entrance of the aneurysm, with organized tissue replacing thrombosis in 2 months. CONCLUSIONS: CEDC is as efficient and safe as GDC. The marker, the ability to induce thrombosis inside the sac and the growth of new endothelium over the orifice are very satisfactory.

Animals↗
PubMed2000

Effect of superantigen on ion electrophysiology and permeability in rabbit maxillary sinus epithelia.

OBJECTIVE: Superantigens are potent inflammatory stimuli which derive from pathogenic microbes such as bacteria, viruses and protozoa. The aim of this study was to investigate the role of superantigens on the function of rabbit maxillary sinus epithelium. METHODS: Twenty New Zealand white rabbits were divided into 4 groups. Rabbit sinus mucosa was separated under a surgical microscope and mounted in Ussing chambers to record short circuit current, conductance and permeability to horseradish peroxidase (HRP). Group A was used as normal control. Group B was stimulated with an injection of superantigen into the sinus for 4 hours. The sinus mucosa of Group C was stimulated by the addition of tumor necrosis factor alpha (TNF-alpha) into Ussing chambers. Group D sinus mucosa was stimulated by superantigen after pretreatment with anti-TNF-alpha antibody. RESULTS: Superantigen evoked increases in sinus epithelial cell baseline short circuit current, conductance and permeability to HRP stimulated by the addition of TNF-alpha into Ussing chambers. These were similar to results from superantigen stimulation in vivo. The effect of superantigen on sinus epithelial cells could be blocked by pretreatment with anti-TNF-alpha antibody. CONCLUSIONS: Superantigen affected the function of sinus epithelial cells, including the capability of epithelial defensive barrier, which might be mediated by TNF-alpha.

Animals↗
PubMed2000

Azathioprine and methylprednisolone: prevention of chronic cerebral vasospasm in dogs.

OBJECTIVE: To study the preventive effects of single use of azathioprine and its combination with methylprednisolone on chronic cerebral vasospasm (CVS). METHODS: A canine model of the "double subarachnoid hemorrhage (SAH)" was established to study the angiogram characteristics of chronic CVS. The effects of azathioprine and its combination with methylprednisolone on the prevention of chronic CVS were observed in a randomized study. The content of malondialdehyde (MDA) and pathological changes in the basilar artery (BA) wall were also analyzed. RESULTS: The results were obtained on the 7th day after subcarachnoid hemorrhage. In the azathioprine group, the BA diameter was 87% +/- 26% of the original BA diameter, and the MDA content of BA wall was 0.03 +/- 0.01 nmol/mg tissue. In the azathioprine plus methylprednisolone group, it was 93% +/- 20% (BA diameter) and 0.02 +/- 0.01 nmol/mg tissue (MDA content). In the control group, the BA diameter was 53% +/- 19% and MDA content was 0.11 +/- 0.05 nmol/mg tissue. Pathological examination confirmed the reduction in BA wall damage in the experimental groups. CONCLUSION: Azathioprine has a preventive effect on chronic CVS following SAH. It may suppress the production of free radicals and reduce damage to the BA wall. Combined use of azathioprine with methylprednisolone allows lower dosage and less complication compared with a single agent, and results in a better outcome.

Animals↗
PubMed2000

[Analysis of the clinical characteristics and prognostic factors with primary normal-sized epithelial ovarian carcinoma syndrome].

OBJECTIVE: To investigate the clinical characteristics and prognostic factors of the primary normal-sized epithelial ovarian carcinoma syndrome. METHODS: The clinical records and pathologic slides of the 10 patients who satisfied the diagnostic criteria were retrospectively analyzed. RESULTS: The primary normal-sized epithelial ovarian carcinoma syndrome was detected in approximately 1.92% of the patients with the epithelial ovarian carcinoma. The age of the patients at diagnosis ranged from 43-70 years, with a median age of 57 years. The most common presentations included anorexia, increasing abdominal girth and awareness of abdominal or pelvic mass. During the exploratory laparotomy although we often discovered the diffuse metastasis throughout the abdominal and pelvic cavity, the ovaries both appeared normal size and had a fine granularity on the external surface. The survival time of patients with remained tumors smaller than 2.0 cm was longer than those with remained tumors larger than 2.0 cm, but the Log-rank evaluation indicated chi 2 = 0.61, P > 0.05. The patients who underwent postoperative chemotherapy have been noted to achieve some long-term survival. The median survival time was 20 months. CONCLUSION: The results predict that the size of the remained tumors may be one of the important factors to the survival and the disease is sensitive to the postoperative chemotherapy.

Adult↗
PubMed2000

[Breast cancer accompanied by Paget's disease: an anlysis of 34 cases].

OBJECTIVE: To better understand the clinical and pathological features, diagnosis, treatment and prognosis of Paget's disease accompanying breast cancer. METHODS: From 1958 to 1997, 34 such patients were operated and pathologically confirmed. RESULTS: Breast cancer combined with Pagat's disease accounted for 0.9% of the total number of breast cancer patients treated in the same period of time. The mean age of patients was 47.3 years, and the mean duration of symptoms was 23.9 months. The patients received combination treatment with surgery as the major treatment modality. Among patients with nipple change as the first symptom, 26.7% of them had positive axillary nodes. The rate of metastasis was 26.7% as confirmed by surgical pathology. The 5-, 10-, and 20-year survival rate was 93.1%, 78.1% and 67.0%, respectively. Among those with palpable mass as the first symptom, metastasis to the axillary lymph nodes occurred in 52.6% of the cases, and distant metastasis in 42.1% of the cases. The rate of 5-, 10- and 20-year survival rate was 60.5%, 53.8% and 53.8%, respectively. CONCLUSION: Paget's disease, as a special form of breast cancer, may accompany cancer inside of the breast. In patients whose disease is confined to the nipple, their prognosis is better than those accompanied by palpable mass in the breast.

Adult↗
PubMed2000

[Sequential non-invasive following short-term invasive mechanical ventilation in COPD induced hypercapnic respiratory failure].

OBJECTIVE: To estimate the feasibility and the efficacy of early extubation and sequential non-invasive mechanical ventilation(MV) in COPD with exacerbated hypercapnic respiratory failure. METHODS: 22 intubated COPD cases with severe hypercapnic respiratory failure due to pulmonary infection (pneumonia or purulent bronchitis) were involved in the study. At the time pulmonary infection had been significantly controlled (resolution of fever and decrease in purulent sputum, radiographic infiltrations, and leukocytosis. We call the time as "Pulmonary Infection Control Window", PIC window) after the antibiotic and the comprehensive therapy, the early extubation was conducted and followed by non-invasive MV via facial mask immediately in 11 cases (study group). Other 11 COPD cases with similar clinical characteristics who continuously received invasive MV after PIC window were used as control group. RESULTS: The groups had similar clinical characteristics and gas exchange, initially and at the time of PIC window. For study group and control group, the duration of invasive MV was (7.1 +/- 2.9) vs (23.0 +/- 14.0) days, P < 0.01; the total duration of ventilatory support was (13 +/- 7) vs (23 +/- 14) days, P < 0.05; the incidence of VAP were 0/11 vs 6/11, P < 0.01; the duration of ICU stay was (13 +/- 7) vs (26 +/- 14) days, P < 0.05, respectively. CONCLUSIONS: In COPD patients requiring intubation and MV for pulmonary infection and hypercapnic respiratory failure, early extubation followed by non-invasive MV initiated at the point of PIC window may significantly decrease the invasive and total durations of ventilatory support, the risk of VAP, and the duration of ICU stay.

Aged↗
PubMed2000

[Proportional assist ventilation: methodology therapeutics on COPD patients compared with pressure support ventilation].

OBJECTIVE: To establish the method for clinical use of proportional assist ventilation (PAV) and evaluate the effect on COPD patients. The main similarities and differences of PAV and pressure support ventilation (PSV) were described. METHODS: 10 ventilated patients of COPD were studied. The elastance and resistance were determined before PAV by both inspiratory-hold technique during a brief period of volume control ventilation and "runaway technique". Either different assist levels of PAV (% assist 80%, 60%, 40%, respectively) or PSV was selected randomly. Values of hemodynamics, blood gas and pulmonary mechanics were monitored. Patients' response was described also. RESULTS: Runaway technique was convenient and reliable. Among different assist percentage no significant difference was found on hemodynamics in stabilized COPD patients. PaO2 was in a good level. Either tidal volume or respiratory rate did not change in a consistent way as the level of assist was decreased. But peak inspiratory pressure was increasing significantly r = 0.928 (P < 0.01) and patients' work of breath had the tendency to decrease (P < 0.05). A significant difference of Borg Category Scale was observed between PAV and PSV [0.50(1.50)] vs [0.75(2.00)], (P < 0.05). No significant difference of hemodynamics was found between the two modes. PaCO2 was significantly higher on PAV than on PSV, 54(24) and 48(23) mm Hg, respectively (P < 0.05). Peak inspiratory pressure on PAV (16 +/- 4) cm H2O was significantly lower than on PSV (21 +/- 3) cm H2O (P < 0.05). CONCLUSIONS: PAV is a feasible method of supporting ventilator-dependent patients that is well tolerated. It can improve breathing pattern and reduce inspiratory effort by decreasing work of breath. PAV can be implemented at much lower peak inspiratory pressure than PSV at the same condition of work of breath by patients. It can also apply proportional pressure support according to patients' ventilatory demand. System that operates according to the theory of PAV is not easy to implement. How to measure elastance and resistance is still a question during the development of PAV.

Aged↗