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Biomedical subjects

J Wu

Publications and source records attributed to J Wu.

At least 1,117 records · Page 62Linked to original sources
PubMed1996

[Isolation of specific DNA probes from Cryptococcus neoformans].

OBJECTIVE: To construct plasmid library and screen specific DNA probes for Cryptococcus neoformans. METHODS: Serotype A Cryptococcus neoformans was used as the study strain, plasmid pUC18 as vector, and Escherichia coli JM103 as host cell. The plasmid library of cryptococcus neoformans was constructed (pCN). Other pathogenes causing affection diseases which should be distinguished from cryptococcusis clinically, and other fungi similar to Cryptococcus neoformans with physiological and biochemical characteristics were used as a distinguishing system, specific colonies were screened by hibridization in double steps. RESULTS: The inserts of the library were 280 to 1800 base pairs and 580 base pairs in average length. Repeated sequence was 32.43% and single copy sequence was 67.57% in genome of cryptococcus neoformans respectively. Three specific colonies were isolated from the library. Colony pCNII A6 was serotype A specific, pCNII B5 species specific and pCNIII G1-specific for var. neoformans. CONCLUSION: A rapid diagnosis of Cryptococcus neoformans infection at early stage can be made by using species-specific probe, and serotype and variaty of neoformans and gattii be distinguished in epidemic study.

Cloning, Molecular↗
PubMed1996

[Azathioprine and its combination with methylprednisolone: preventive effect on chronic cerebral vasospasm].

OBJECTIVE: To study the effects of azathioprine alone and combined azathioprine and methylprednisolone on chronic cerebral vasospasm. METHODS: An animal model of "double subarachnoid hemorrhage" was established by two cisterna magna injections of non-heparinized autologous arterial blood (0.3 ml/kg). The preventive effect of azathioprine alone and its combination with methylprednisolone on chronic cerebral vasospasm was studied. By angiography of vertebrobasilar artery with a transfemoral catheter, assay of LPO (lipid peroxidation) was performed on BA wall. Chronic cerebral vasospasm following subarachnoid hemorrhage was noted and the drugs' effect on chronic cerebral vasospasm also observed. RESULTS: Seven days after subarachniod hemorrhage, the basilar arterial (BA) diameter was 87% +/- 26% of the original BA diameter, and LPO content of BA wall was 0.03 +/- 0.01 nmol/mg in azathioprine group and 93% +/- 20% (BA diameter) and 0.02 +/- 0.01 nmol/L (LPO content) in azathioprine plus methylprednisolone group. When the BA diameter was 53% +/- 19%, the LPO content was 0.11 +/- 0.05 nmol/mg in the control group. Pathological examination showed that azathioprine alone and its combination with methylprednisolone obviously reduced the damage to the BA wall. CONCLUSION: Azathioprine has preventive effect on chronic cerebral vasospasm, supresses the production of free radicals and reduces damage to the BA wall following subarachnoid hemorrhage. Combined azathioprine methylprednisolone has produces better effects when only lower dosage is used.

Animals↗
PubMed1996

[Human mucoepidermoid carcinoma MEC-1 cells induced differentiation by HMBA].

Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands. In this report, we used hexamethylene bisacetamide (HMBA) as a inducer to induce human mucoepidermoid carcinoma cell line MEC-1 cells to differentiate. The growth kinetics, morphological changes and DNA contents of the cells were investigated. The results showed that HMBA-treated MEC-1 cells tend to become mature cells, implying that HMBA can induce differentiation of MEC-1 cells in vitro.

Acetamides↗
PubMed1996

[Percutanous trans-catheter intervention for the diagnosis and treatment of malignant pericardial effusion, with a report of 50 cases].

Diagnosis and treatment of malignant pericardial effusion are difficult in clinical practice. This paper reports the feasibility and reliability of percutanous trans-catheter intervention for the diagnosis and treatment of malignant pericardial effusion. Under echocardiagraphic guidence, pericardial puncture was performed and a heamostasis sheath was placed in situ by Seldinger technique. Through the sheath multiple biopsies of the pericardium were taken for pathological examination. A pigtail catheter was inserted to drain off the effusion. According to pathological report suitable anti-cancer drugs were instilled into the pericardial cavity through indwelling catheter for 3-5 days. The catheter was withdrawn when fluid did not re-accumulate. Diagnosis was made in over 96.0% of the cases. Upon follow-up for 3-6 months, complete remission was seen in 96.0% of the treated patients. No significant complication was found in all patients. Percutaneous trans-catheter intervention is a useful approach for the diagnosis and treatment of malignant pericardial effusion.

Adenocarcinoma↗
PubMed1996

[Expression of CD44v mRNA and its clinical significance in colorectal carcinoma].

In order to study the correlation of the CD44v gene abnormal expression and splicing with the clinicopathologic features, the expression of CD44v mRNA from normal colorectal mucosa, adenomatous polypi (precancerous disease) and colorectal carcinoma was studied by RT-PCR and cDNA hybridization. The results showed that CD44v mRNA was expressed in 65 of 67 (97%) primary cancers, in 20 of 20 metastatic tumors (100%) and in 5 of 7 (71.4%) precancerous diseases, but was not expressed in all 15 normal colon mucosa specimens. Abnormally spliced, high molecular weight CD44v could be detected in 10 of 20 (50%) primary cancers and in 18 of 20 (90%) metastatic cancers. In 10 patients with high molecular weight CD44v, metastases were found in 8, while metastases were found in only 2 of 10 patients with low expression of CD44v mRNA in the primary cancers. The results suggest that the expression of CD44v is very common in colorectal carcinoma. CD44v mRNA might be an early marker of colorectal carcinoma and its high expression is suggestive of tumor metastasis.

Adult↗
PubMed1996

[Detection of micrometastases in axillary lymph nodes of node-negative breast cancer patients and its clinical significance].

Monoclonal antibodies against cytokeratin (AE1/AE3) were applied as a prob, using APAAP immunohistochemistry technique to detect 635 lymph nodes from 45 breast cancer patients with negative lymph nodes. Micrometastases were identified in 14 lymph nodes of 9 cases (20%). A significant difference was found between cytokeratin staining positive group and cytokeratin staining negative group in disease-free and over-all Kaplan-Meier survival curves. The detection of micrometastases had more clinical value for T1 and T2 patients. One of 2 T1 cytokeratin positive cases relapsed while only 1 of 19 T1 negative cases relapsed within 5 years, three of 5 T2 cytokeratin positive cases relapsed while 1 of 17 negative cases did. The presence of micrometastases had the same value in predicting local recurrence and distant metastases.

Adenocarcinoma↗
PubMed1996

Inhibition of spontaneous apoptosis in human breast cancer.

Breast tumorigenesis proceeds through an accumulation of specific genetic alteration. Breast malignant transformation is dependent on not only the rate of cell production but also on apoptosis, a genetically programed process of autonomous cell death. We investigated whether breast tumorigenesis involved an altered susceptibility to apoptosis and proliferation by examining normal breast epithelium and breast cancer samples. We found there is a great inhibition of spontaneous apoptosis in breast cancer cells compared with normal breast epithelium. The inhibition of apoptosis in breast cancer may contribute to neoplastic transformation.

Apoptosis↗
PubMed1996

[Differentiation effect of hexamethylene bisacetamide (HMBA) on mucoepidermoid carcinoma in vivo].

The differentiation effect of HMBA was examined in mucoepidermoid carcinoma transplanted to athymic mice. The animals were divided into HMBA and control groups. The effects were evaluated by inhibitory rate of tumor growth, the survival period and the morphological changes of cells. The results showed that the inhibitory rate of tumor growth was 71.7%, the survival period of HMBA group was 49.6 days while control group was 38.3 days, the cells of HMBA group tended to become more mature, and the mean number of AgNORs was also significantly reduced. These results indicate that HMBA can induce the MEC-1 cells to differentiate toward nomal or benign cells in vivo.

Acetamides↗
PubMed1996

[An electromyographic study of masticatory muscle changes in patients with mandibular protrusion before and after orthognathic surgery].

27 patients with mandibular prognathism were studied with 40 normal people as controls. All subjects were examined with electromyogram. The result shows that the voltage were lower in patients before surgery, the double-silent period inspect rate were much higher than normal subjects. It was concluded that the electromyo-activity of masticatory muscles had some character in patients after surgery: (1) The voltage of masseter and temporal muscle increased significantly during maximal voluntary clenching. (2) During protrusive border movement the voltage of masseter increased while the changes of voltage in the temporal muscle were small. (3) In lateral border movement, the voltage of masseter and temporal muscle increased in the working side, while the balaning side changed slightly. (4) Electromyo-voltage decreased in rest position. (5) The duration of silent period had a tendency of shortening after surgery. It demonstrated the feasibility and necessity of treating mandible deformity through orthognathic surgery, and it provided theoretical and practical support of evaluating the treatment effect of such kind of patients.

Adult↗
PubMed1996

[An investigation of immunoreactive substances in normal gingival tissue and periodontitis tissue].

In order to study the effects of NO, endothelin (ET), substancep (SP) and caleiton gene-related paptide (CGRP) immunoreactive substances in chronic periodontitis tissue and the relationship with periodontitis, immunohistochemical and histochemical staining methods were used respectively to detect the expression of the above immunoreactive substances in 20 patients with chronic periodontitis. Quantitative analysis showed that NO and ET in periodontitis tissues were increased significantly (P < 0.01), particularly the content of ET, in comparison to normal tissue. Due to the increase of ET content, the bolld supply was diminished and influenced the periodontal tissue by causing tissue damage. This study suggests that NO and ET immunoreactive substances are closely associated with periodontitis and may play an important role in the disease. There were no marked changes on SP and CGRP.

Calcitonin Gene-Related Peptide↗
PubMed1996

[Causes of death of pancrease hemorrhage. Report of 35 autopsy cases].

The causes of death of 35 cases of pancreas hemorrhage have been analysed. The pancreas hemorrhage was seen not only in acute hemorrhagic pancreatitis, but also in poisoning, mechanical injury, mechanical asphyxia, and heart disease. The diagnosis and pathogenesis of acute hemorrhagic pancreatitis were discussed.

Acute Disease↗
PubMed1996

[Genetic polymorphism of antithrombin III in five Chinese populations].

The genetic polymorphisms of antithrombin III (AT III) in 5 Chinese populations were studied by isoelectric focusing on polyacrylamide gels followed by immunoblotting. The products of two alleles at the antithrombin III locus together with 1 AT III anodic variant and 3 cathode variants were observed. The results revealed that the predominant allele of AT III blood group system in Chinese populations was AT III *1, with frequencies between 0.9773-0.9850. Frequencies of AT III *2 ranged from 0.0091 to 0.0169. These results indicate that the polymorphic information content of AT III blood group system in Chinese populations is limited.

Alleles↗
PubMed1996

[Immunohistochemical study on morphine in human tissues from opiate associated death].

The morphine distribution in human tissues was studied by immunohistochemical method. Four cases of opiate associated death were examined. Morphine was demonstrated not only in some neuronal cytoplasma of cerebral cortex, hippocampus, basal ganglia thalamus, brainstem, and cerebellum, but also found in some nervous fibers and some capillary walls in the central nervous system. Besides, it was also found in the capsule and mesenchyma of heart, liver, spleen, lung, kidney, adrenal gland, pancreas, thymus, thyroidea and testis. Morphine was not seen in the parenchyma of these organs. It was suggested that the postmortem redistribution was not in the central nervous system, but in other organs. We considered that immunohistochemical staining of morphine is useful in the diagnosis of death from opiate addiction.

Adult↗
PubMed1996

[Nested polymerase chain reaction (PCR) and multiple cloned antibody capture PCR for the examination of serum hepatitis B virus DNA in negative hepatitis B surface antigen patients suffering from liver diseases].

In order to find out rapidly the causes of the liver diseases suffered by patients with negative hepatitis B surface antigen (HBsAg), nested polymerase chain reaction (PCR) and multiple cloned antibody capture PCR techniques were established to examine serum hepatitis B virus (HBV) DNA. By using both techniques along with the examination of hepatitis C virus (HCV) infection, the causes of chronic liver diseases with negative HBsAg were studied. It is found that nested-PCR can increase the sensitivity of single PCR more than 1,000 fold and multiple cloned antibody capture-PCR can detect concentration of HBV DNA as low as 0.1-0.01 pg/L. HBV DNA positive patients were found in 45.5%, 30.8%, 13.3% and 100% respectively of the patients suffering from liver cirhosis with negative HBsAg (group A, 22 cases), chronic hepatitis with negative HBsAg (group B, 13 cases), normal subjects with negative HBsAg and positive hepatitis B core antibody (HBcAb, group C, 30 cases) and liver cirhosis with positive HBsAg and negative HBeAg (group D, 12 cases). HBV DNA can be also found in the serum of HBsAb positive patients and subjects supposed to be healthy, 81.8% and 53.8% of the patients were infected with HBV and/or HCV in group A and group B respectively. All these results suggest that nested-PCR and multiple cloned antibody capture-PCR are rapid and highly sensitive methods for detection of serum HBV DNA. HBV infection is an important cause of chronic liver diseases in patients with negative HBsAg. The causes of most of the HBsAg-negative chronic liver diseases are related with infection of viruses. The clinical significance of serum HBsAb in naturally infected patients should be reconsidered.

Adult↗
PubMed1996

[The diagnostic value of flow cytometric DNA analysis of bronchial washing and lavage fluids in lung cancer].

OBJECTIVE: To evaluate the diagnostic value of flow cytometric DNA analysis of bronchial washing and lavage fluids in lung cancer. METHODS: The cellular DNA contents of bronchial washing and lavage fluids from 68 patients (43 with lung cancer and 25 with benign pulmonary disorder) were analyzed by flow cytometry, and the diagnostic value of this method in lung cancer was compared with that of fiberoptic bronchoscopic biopsy and brushing. RESULTS: The presence of aneuploidy was used as a diagnostic criterion, the sensitivity of DNA analysis was 81%, and the specificity was 92%. The positive rate of aneuploidy in central lung cancer (29) was 83%, and there was no statistical difference when compared with biopsy (90%) and brushing (69%). The positive rate of aneuploidy in peripheral lung cancer (14) was 79%, significantly higher than biopsy (29%) (P < 0.025) and brushing (29%) (P < 0.025). In a few patients from both central and peripheral lung cancer groups, biopsy and brushing appeared negative, but aneuploidy was obtained from cytometry. CONCLUSION: These results suggest that flow cytometric DNA analysis of bronchial washing and lavage fluids may be a valuable adjunctive method in the diagnosis of lung cancer, particularly in peripheral lung cancer.

Adenocarcinoma↗
PubMed1995

Mechanisms of animal cell damage associated with gas bubbles and cell protection by medium additives.

Animal cell damage arising from gas sparging is considered to be a major barrier to large-scale production of recombinant biologicals in animal cell culture. Understanding sparging cell damage is therefore of significance to the application of animal cell culture. The paper reviews the hydrodynamics of bubble rupture, mechanisms of cell-bubble interaction, mathematical modelling and quantification of the sparging damage. Another interesting topic addressed in the paper is the protective effects of various medium additives against fluid mechanical cell damage, especially those surface-active polymers such as pluronic polyols, methylcellulose and polyethylene glycol. Experimental results obtained recently by the author and other researchers were examined to reveal the mechanisms of additive protection. The interactions of additives with air-liquid interfaces and the animal cells were analyzed with respect to their physical properties and chemical structure.

Animals↗
PubMed1995

Participation of reactive oxygen species in the lysophosphatidic acid-stimulated mitogen-activated protein kinase kinase activation pathway.

Recent evidence suggests that reactive oxygen species (ROS) may function as second messengers in intracellular signal transduction pathways. We explored the possibility that ROS were involved in lysophosphatidic acid (LPA)-induced mitogen-activated protein (MAP) kinase signaling pathway in HeLa cells. Antioxidant N-acetylcysteine inhibited the LPA-stimulated MAP kinase kinase activity. Direct exposure of HeLa cells to hydrogen peroxide resulted in a concentration- and time-dependent activation of MAP kinase kinase. Inhibition of catalase with aminotriazole enhanced the effect of LPA on induction of MAP kinase kinase. Further, LPA stimulated ROS production in HeLa cells. These findings suggest that ROS participate in the LPA-elicited MAP kinase signaling pathway.

Enzyme Activation↗