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Biomedical subjects

M Zhang

Publications and source records attributed to M Zhang.

At least 811 records · Page 45Linked to original sources
PubMed1996

Vascular expression of glucose transporter in and around hematogenous metastases of the human brain. Immunohistochemical observations.

The expression of the glucose transporter protein, GLUT 1, in endothelial cells of microvessels within and around hematogenous metastases of the human brain was investigated by immunohistochemistry using a polyclonal antibody raised against the carboxyl terminus of the transporter molecule. The metastases were obtained from 18 autopsy cases with pulmonary carcinomas. Endothelial cells of controls without evidence of brain pathology showed a strong immunoreactivity, indicating that the antigenic sites of the glucose transporter remained in the postmortem material. The endothelial cells of microvessels around the metastases did not show any changes with regard to expression of the glucose transporter. However, in 14 of the 18 tumor cases, microvessels located in the metastases did not express the transporter. Our results indicate that in human cases of brain metastases functional changes with regard to glucose transport occur within the metastases rather than in the peritumoral region.

Adult↗
PubMed1996

[Clinical evaluation of TPA-assay kit using monoclonal antibodies].

The clinical utility of a newly-developed radioimmunometric assay kit for tissue polypeptide antigen (TPA) was evaluated focusing on the serum diagnosis of gastrointestinal cancers. Serum TPA concentrations of normal subjects, patients with various benign and gastrointestinal malignant diseases were measured using this kit. From the TPA concentrations of normal subjects, the cut-off value was determined to be 70 U/l, which was 40 U lower than the previous kit. It showed a fairly high false positive rate in patients with liver dysfunction, so care should be taken in evaluating patients with liver disorders. It showed high positive rates in patients with wide range of gastrointestinal cancers, confirming the wide-range usefulness of this assay. Cancer patients with advanced stages and recurrences showed a higher positive rate and also higher serum TPA concentrations than in the early stages, indicating that this TPA assay is especially useful in the evaluation of therapeutic effects and in the detection of recurrent diseases.

Antibodies, Monoclonal↗
PubMed1996

HLA-DRB1 and DQB typing of Hispanic American patients with rheumatoid arthritis: the "shared epitope" hypothesis may not apply.

OBJECTIVE: To determine whether the association of particular MHC class II alleles and the DRB1 "shared epitope" with disease susceptibility and severity in rheumatoid arthritis (RA) applies to ethnic groups other than Caucasian Americans. METHODS: 67 Hispanic American patients with RA and a similar number of ethnically matched controls were typed for DRB1 using polymerase chain reaction methods. DR4 subtype and DQB1 type were determined for the subjects positive for DR4. Disease severity in the patients with RA was assessed by clinical, radiographic and laboratory variables. RESULTS: The frequency of DR4 was significantly increased in the subjects with RA compared to the control group. However, the "shared" DRB1 amino acid sequence was relatively infrequent in the Hispanic American patients with RA, and there was no association of specific DR4 or DQ alleles with more severe disease or extraarticular manifestations. CONCLUSION: The HLA markers that predict poor prognosis and suggest that more aggressive clinical management may be appropriate in Caucasian American patients with RA may not be useful in other ethnic groups.

Arthritis, Rheumatoid↗
PubMed1996

[Experimental study on delayed effect of external skin expansion].

In using the external skin expander, we found that the expanded skin had the feature similar to a delayed flap. To study its mechanism, we chose 20 New Zealand rabbits and divided them into 2 groups randomly. The skin on the animal's back in the experimental group was expanded with the external skin expander. The laser Doppler flowmeter (LDF) and oxyhemograph (SpO2) were applied to detect skin microcirculation. The survival area and the results of microangiography of the two groups were compared. Results showed that the value of LDF of the expanded skin increased and the value of SpO2 returned to its origingal level at 12 days after expansion. The survival area in the experimental group was larger than the control. Microangiographic examinations indicated that the subcutaneous vascular anastomoses were obviously increased in the experimental group. We conclude that external skin expansion does not affect the quality of the expanded skin, and its effect is similar to delay technique.

Animals↗
PubMed1996

[16S rRNA gene PCR-SSCP analysis of the reference strains from 15 serovars (14 serogroups) of pathogenic leptospires in China].

The DNAs of reference strains from 15 serovars (14 serogroups) of pathogenic leptospires in China were amplified with 16S rRNA gene primers, and then single-strand conformation polymorphism (SSCP) of the products were analyzed in 12.5% nondenaturing mini polyacrylamide gel (containing 5% glycerol) combining with silver-staining. All products showed two bands on electrophoresis at different parameters of voltage or current and concentration of gel. It proved that serovar lai, serovar canicola, serovar pyrogenes, serovar autumnalis, serovar australis, serovar pomona, serovar linhai, serovar hebdomadis, serovar haemolytica, serovar wolffi and serovar paidjan have the identical pattern (Leptospira interrogans), while serovar javanica, serovar ballum, serovar tarassovi and serovar manhao I belong to another pattern (L. borgpetersenii). The result was consistent with the classification of genetic species by Yasuda et al (1987) and Ramadass et al (1992).

China↗
PubMed1996

[Study on platelet antioxidant enzyme activity and platelet granule membrane glycoprotein in patients with pregnancy induced hypertension].

OBJECTIVE: To evaluate the platelet antioxidant enzyme activity and platelet activation degree in patients with pregnancy induced hypertension (PIH). METHODS: A monoclonal antibody specific for alpha-granule membrane protein (GMP-140) of platelet was used to evaluate the platelet (plt) activation degree in 44 cases with PIH and 28 cases of normal pregnant women. Meanwhile, the platelet antioxidant enzyme (superoxide dismutase, SOD; catalase, CAT) activity were determined. RESULTS: Platelet SOD activity of PIH (22.08 +/- 7.66 U/10(9) plt) was markedly lower than that of the controls (26.67 +/- 7.59 U/10(9)plt, P < 0.01). There was no difference between the CAT activity of PIH and controls (9.26 +/- 4.53 K/10(12) plt, 8.57 +/- 3.69 K/10(12) plt, P > 0.05). The number of GMP-140 molecules on platelet surface and serum levels of PIH (2073 +/- 902 molecules/plt, 4.65 +/- 1.74 molecules/L x 10(-13) were significantly higher than those of the normal pregnant women (1319 +/- 716 molecules/plt, 1.69 +/- 0.78 molecules/L x 10(-12), P < 0.01). Correlation analysis between GMP-140 on platelet surface, GMP-140 in the serum and SOD activity of PIH showed definite negative correlation (r = -0.601, -0.670 respectively, P < 0.05). CONCLUSIONS: The decline of platelet antioxidant enzyme activity (especially SOD) and platelet activation could play an important role in the pathophysiological changes in PIH. The platelet SOD activity and GMP-140 could be new index of platelet hyperactivity.

Adult↗
PubMed1996

[Expression of placental alkaline phosphatase in esophageal cancer cell line Eca109].

The expression and property of alkaline phosphatase (ALP) in Eca109 cells, a cell line derived from human esophageal carcinoma were studied with specific inhibition assay and poly-acrylamide gel electrophoresis. The results showed that ALP of Eca109 cells was heat stable and was strongly inhibited by L-phenyalanine, but slightly inhibited by urea. Prednisolone could cause dramatic increase in activity of ALP, but no change in ALP isozyme spectrum and concomitant increase in lactic dehydrogenase activity were found after prednisolone treatment. The results suggested that placental alkaline phosphatase as an oncofetal gene product could be expressed ectopically by Eca109 cells and prednisolone could specifically induce increase in its activity.

Alkaline Phosphatase↗
PubMed1996

[99mTc-pingyangmycin imaging to assess treatment response of patients with lung cancer].

The aim of this study was to investigate the possibility of functional imaging for the assessing of treatment response in patients with lung cancer. Thirty one patients were studied by 99mTc-Pingyangmycin (PYM) imaging. A region-of-interest technique was used in planar scan and the retention index (RI) was obtained to evaluate quantitatively the degree of 99mTc-PYM retention in the lesions. It was found that the RI was significant difference between responder (-5.01 +/- 4.97, -6.78 +/- 3.05) and nonresponder (4.38 +/- 2.13, 15.25 +/- 5.92, P < 0.05, P < 0.001) to chemotherapy or radiotherapy. Significant difference was also seen between patients with stable disease (-6.07 +/- 8.45) and those with disease progression (12.66 +/- 5.23, P < 0.01) after surgical treatment. Repeated examinations showed good correlation between difference of pretreatment and posttreatment RI and reduction of tumor volume (r = 0.8959, P < 0.01). Therefore, RI can be taken as a predictive index in assessing tumor response to treatment and in monitoring lung cancer patients surgically treated.

Adenocarcinoma↗
PubMed1996

[Clinical importance of p53 gene mutation and PCNA expression in ureteral and renal pelvic cancers].

In order to know the clinical importance of p53 gene mutation and PCNA expression in ureteral and renal pelvic cancers, research was carried out with immunohistochemistry S-P method in 45 cases. Mutant p53 nuclear staining was positive in 24 cases (53.3%) and correlated with PCNA expression, being higher in clinical stages T3 and T4 than in T1 + T2. They also correlated with the grade of cell differentiation, being higher in G3 than in G1 + G2.

Genes, p53↗
PubMed1996

[Experimental study on vascularized area of the prefabricated axial skin flap after implantation of vascular bundles].

Thirty-eight New Zealand white male rabbits were used to study vascularized area of the prefabricated axial skin flaps (PASFs) after implantation of vascular bundles (VBs) into subcutaneous tissues of the animal's abdomen. Influential factors were investigated including the interval after implantation, the size of VBs, the subcutaneous layer where VBs were implanted and simultaneous skin expansion. The results indicated that the suitable time for PASFs transferring was 3-4 weeks after implantation of VBs. The VBs of larger diameter prefabricated larger area of PASFs. Larger areas of PASFs were created by implanting VBs into the subcutaneous layers that possessed rich vascular plexuses. It was possible that the expanded PASFs could be transferred.

Animals↗
PubMed1996

[The value of the clinical test of glucocorticoid receptors of peripheral blood leukocytes in patients with chronic pulmonary heart disease].

In order to inquire into the functional state of adrenal cortex in patients with pulmonary heart disease, the number of glucocorticoid receptors(GCR) of peripheral blood leukocytes in patients with chronic pulmonary heart disease was determined with radioligand-binding assay and the corresponding plasma cortisol levels were assessed with radioimmune assays. The results showed that the number of GCR in the patients was significantly reduced (P < 0.01) and it was increased when their health state was improved. However, it was still lower than that in healthy subjects (P < 0.01). The number of GCR in the patients was greatly increased when these patients were treated with oxygen (P < 0.01). No difference in plasma cortisol was found between the patients and the healthy subjects (P > 0.05). These results indicate that the function of adrenal cortex may be improved by the compensation mechanism of the patients, but the lower GCR number was the result of lacking of oxygen in the patients. The number of GCR may be improved by inhalation of oxygen. Therefore oxygen therapy is helpful in raising the activity of glucocorticoid receptors and controlling the development of the disease.

Adult↗
PubMed1996

[A study on the control of air toxic chemicals in workplace for bakelite manufacturing and casting].

Air concentrations of phenol, formaldehyde and ammonia related to the contents of free phenol, formaldehyde in raw material, and solidifying agent-urotropine in bakelite. Due to the solubility of phenol and formaldehyde, in the manufacture process, water was added to lower contents of phenol and formaldehyde in bakelite, and content of urotropine was reduced in bakelite sand presceription to lower air concentrations of phenol, formaldehyde and ammonia. As contents of phenol and formaldehyde in bakelite reduced to 4.9% and 0.037% from 6.32% and 0.062%, respectively, air concentrations of phenol, formaldehyde and ammonia lowered to 0.61 mg/m3, 0.69 mg/m3, and 5.1 mg/m3 from 2.94 mg/m3, 1.72 mg/m3, and 12.9 mg/m3, respectively, and incidence rate of skin disease in the employees of the workplace decreased to zero from 80.2%. It is recommended that a hygienic standard for allowable concentration of mixed toxic chemicals in the workplace air for bakelite manufacturing be formulated as soon as possible.

Air Pollutants, Occupational↗
PubMed1996

[Observation on TXB2 and 6-keto-PGF1 alpha in serum of patients with cor pulmonale].

To know the changes of TXA2 and PGI2 in serum of patients with cor pulmonale, the levels of their stable metabolites TXB2 and 6-keto-PGF1 alpha in serum were examined in 28 patients with cor pulmonale during alleviation, 29 patients with cor pulmonale during exacerbation before and after treatment and 10 healthy subjects. TXB2 and 6-keto-PGF1 alpha were 109.74 +/- 56.14 ng/L and 54.76 +/- 35.62 ng/L respectively in healthy subjects; TXB2/6-keto-PGF1 alpha = 2.004. The TXB2 level of patients with cor pulmonale at every stage was higher than that of healthy subjects (P < 0.05-0.01). Patients with cor pulmonale during exacerbation had the highest TXB2 level of 709.22 +/- 354.49 ng/L, which decreased to 408.24 +/- 289.41 ng/L (P < 0.05) after treatment with traditional Chinese medicine combined with western medicine and the decreased level as such was not significantly different from that during alleviation (333.14 +/- 324.14 ng/L). The 6-keto-PGF1 alpha level in patients with cor pulmonale at every stage was not significantly different from that of healthy subjects. Since TXB2 increased, the value TXB2/6-keto-PGF1 alpha of patients with cor pulmonale was greater than that of healthy subjects. It is most likely that chronic hypoxia and hypercapnia lead to prostaglandin release in the lung of patients with cor pulmonale; hypoxia and hypercapnia become more severe during exacerbation resulting from infection; which lead to increased prostaglandin release, then high TXB2 level ensue as the result. TXB2 decreases after amelioration of hypoxia during treatment. But the change of 6-keto-PGF1 alpha is not obvious.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

[Dynamic analysis of cell surface markers in acute leukemias unclassified with immunologic criteria].

In order to study the cell origin of acute leukemia with lack of lineage specific antigen expression, the dynamic change of cell surface markers in 25 patients of acute leukemia unclassified with immunologic criteria were analysed by using APAAP immunoenzymatic method with monoclonal antibodies after chemotherapy or relapse. The results showed that 5 patients, whose leukemic cells expressed only CD38 antigen in the first visit, expressed T cell differentiated antigen after chemotherapy or relapse. 4 patients, who expressed B cell specific markers after chemotherapy or relapse, all expressed only CD9 antigen in the first visit. 4 of the 6 patients who expressed only HLA-DR antigen were found to have B cell markers on their leukemic cells surface after chemotherapy or relapse. One patient expressed B cell surface markers after chemotherapy and another expressed T cell surface markers after relapse, both of them expressed CD38 and HLA-DR antigens in the first visit. In 4 other patients whose leukemic cells were lacking of in any cell differentiated antigen expressing, one expressed B cell markers and another expressed T cell markers after chemotherapy. The change of cell surface markers showed the evolution and progression of leukemic cell clone. Dynamic study is useful to distinguish the cell origin of leukemia.

Acute Disease↗