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Biomedical subjects

R Wang

Publications and source records attributed to R Wang.

At least 505 records · Page 28Linked to original sources
PubMed1996

[Study on sister chromatid exchange in lymphocytes of women with fetal intrauterine growth retardation].

OBJECTIVE: To study sister chromatid exchange (SCE) frequency in lymphocytes of pregnant women with intrauterine growth retardation (IUGR) infants. METHODS: The frequency of SCE in peripheral blood lymphocytes of 14 pregnant women with IUGR babies and 90 normal pregnant women as well as the umbilical blood of their infants were investigated. RESULTS: The mean frequency of SCE in maternal and umbilical blood with normal pregnancy were 7.58 +/- 0.32 and 5.05 +/- 0.29 respectively, while they were 10.53 +/- 2.69 and 7.25 +/- 1.34 in IUGR group respectively. The difference of SCE levels between the 2 groups of mother was statistically significant (P < 0.01), so was that of the umbilical blood group. CONCLUSION: One of the causes of IUGR may be related to heredity injury. Thus, SCE will be a new diagnostic index to predict IUGR.

Adult↗
PubMed1996

[Multiple genetic expression abnormalities in gastric cancer].

UNLABELLED: By means of LSAB and ABC techniques, the expressions of p53, c-erbB-2, EGFR and ras were examined on 75 cases of gastric cancer (GC) specimens. RESULTS: (1) The positive rate of p53, c-erbB-2, EGFR and ras expression was 41.3%, 18.7%, 61.3% and 46.7%, respectively. The early cases and the intestinal type cases of GC had higher p53 positive rates than those of the advanced and the diffuse type ones, respectively. Two of 4 cases of severe dysplasia lesions adjacent to carcinoma sites were positive. c-erbB-2 positive immunoreactivity was only localized in the cancer cells, and tissues adjacent to the carcinoma sites were negative. Higher frequencies of c-erbB-2 expression were found in the well-differentiated GC. Positive correlation was found between EGFR expression and degree of malignancy of GC. (2) No correlation was found between the expression of c-erbB-2 and EGFR. (3) The expression of ras correlated positively with EGFR expression, but negatively with c-erbB-2 (P < 0.05). (4) No correlation was found between the expression of p53 and other genes examined. The results demonstrate that many gene abnormalities are present in the process of gastrocarcinogenesis.

Female↗
PubMed1996

[Expression of myelin basic protein gene in the developing human brain].

The expression of myelin basic protein (MBP) gene in the developing human brain was studied by using Northern dot blot and in situ hybridization with 32P- and biotin-labeled rat MBP cDNA and Diglabeled human MBP cRNA probes so as to explore the relation of temporal and spatial expression of human MBP gene to myelinogenesis and myelination. The results of dot blot analysis showed that the expression of MBP mRNA was near 2.0 A590/microgram of RNA in the fetal brain at 16 weeks of conceptional age, and it increased progressively with development to have 9-fold increment (18 A590/microgram of RNA) in the adult brain. The insitu hybridization was performed with the sections of fetal spinal cord and medulla oblongata at 8-25 weeks of conceptional age, and of pons, midbrain, thalamus, cerebellum and cerebrum at 20, 22 and 25 weeks. The results indicated that the expression of MBP mRNA was found as early as 8-9 weeks and localized within the perinuclear cytoplasm of the scattered cells in the ventral horn of spinal cord and near the basis of the fourth ventricle of medulla oblongata. Whether the above-mentioned labeled cells are neurons or precursors of glial cell remains to be identified because they are larger in size and have more abundant cytoplasm than oligodendrocytes. The labeling of MBP mRNA abruptly increased and spread with the processes of oligodendrocytes to form a network in spinal cord and medulla at 20 weeks; meanwhile, labeling was obvious in pons and scattering in the other brain regions examined.

Adult↗
PubMed1996

[Expression of human brain myelin basic protein gene cDNA in Escherichia coli].

A 612bp full-length cDNA sequence coding for 21.5 kd myelin basic protein (MBP) was amplified from human brain cDNA library by polymerase chain reaction, cloned into vector pGEM-3Zf(+) with blunt-end. The 561bp cloned fragment was recovered from recombinant pGEMP after BamHI digestion, and then inserted into the BamHI site downstream of the glutathione-S-transferase gene of the expression vector pGEX-5T. The recombinant vector p5TBP was transformed into E. coli JM 109 and positive colonies were incubated in LB medium containing 1 mmol/L IPTG for six hours at 37 degrees C. A new polypeptide band with an apparent molecular weight 49 kd was detected in transformed cell lysates by SDS-PAGE. Western blotting analysis confirmed that this fusion protein reacted specifically with rabbit antibodies to human MBP. The expression level of MBP in this system was about 50 mg/L of bacterial culture estimate by immuno-dot blot, ELISA and absorbance scanning of SDS-PAGE.

Cloning, Molecular↗
PubMed1996

[The serum MBP, myelin sheath immunohistochemistry and electromicroscope of expetrimental epilepsy rats].

We detected the level of myelin basic protein (MBP) in the serum of experimental epilepsy rats using simplified MBP ELISA, and the myelin sheaths of their brain with MBP immuno-histochemistry (IHC) and transmitted electronmicroscopy (TEM) in order to explore the relation of brain myelin sheaths and MBP to the pathogenic mechanism of epileptic seizure. The results show that the serum MBP level in the experimental epilepsy group is significantly higher than that in the control groups (P < 0.05), and is similar to that in some patients with generalized myoclonic seizures reported by us previously. The IHC and TEM findings in the brain of epilepsy rats indicate that the lamelliform structure of myelin sheaths in some part of hippocampus region becomes relaxing, disorderly and homogenized. Our studies imply that epileptic seizures are associated with MBP release from the subtle damaged regions of myelin sheaths during epileptic seizures, and the change of MBP component in myelin sheath may play and important role in the pathogenesis of epilepsy.

Animals↗
PubMed1996

[Pterygium and lipid peroxidation].

OBJECTIVE: The mechanism of light damage causing pterygium was investigated from the point of view of lipid peroxidation. METHODS: 22 patients with pterygium underwent excision of pterygium and a little superior bulbar conjunctiva was excised as normal control. The lipid peroxidation reaction of both pathologic and normal samples was analyzed by measuring the concentration of malondialdehyde. RESULT: The concentration of malondialdehyde in the pathologic samples was much higher than that in the normal samples (P < 0.01). CONCLUSION: Light Induced peroxidation reaction is closely related to the pterygium formation.

Humans↗
PubMed1996

[The effect of tinidazole in the treatment of adult periodontitis].

Fifty-two adult periodontitis patients were treated by the tablets of tinidazole (TNZ), and 23 patients treated by metronidazole (MNZ) served as control group. The effective rate of TNZ in adult periodontitis patients was 73.1%, which was significantly higher than that of the control group (43.5%). Antimicrobial studies showed that the capability of TNZ to kill the periodontal dominant anaerobic bacteria, especially B. gingivalis and B. melaninogenicus, was better than that of MNZ. The minimal inhibitory concentration (MIC) of TNZ to Bacteroides, Fusobacterium, Veillonella, Eubacterium, Antinomyces, Peotostreptococus and Anaerobic Streptococus was lower than that of MNZ and actylspiramycine.

Adult↗
PubMed1996

[Nasal septal deviation in fetuses].

To investigate the etiology of nasal septal deviation, twenty-four fetal sinonasal specimens aged between 8-40 weeks of gestation were studied under light microscopy. Sixteen fetal heads aged between 32-40 weeks were examined using 2.7 mm 5 degrees Wolf endoscope. Five of 24 fetal sinonasal specimens were confirmed histopathologically to have deviated nasal septum. 1 of 16 fetal heads was considered to have nasal septal deviation. The existence of nasal septal deviation in fetuses was confirmed. To explain the embryogenesis, we suggested that maldevelopment of vomeropalatal complex is responsible for the formation of nasal septal deviation in fetuses.

Female↗
PubMed1996

[CT study of the ostiomeatal complex in patients with deviated nasal septum].

This study was designed to evaluate the influence of nasal septal deviation on ostiomeatal complex (OMC). From April 1994 to February 1995, 32 patients with deviated nasal septum were investigated by high-resolution CT scan. The results showed that (1) 15 patients (15/32) were found to have ipsilateral or bilateral ostiomeatal complex disease (OMCD). The incidence of OMCD was related to the severity of the septal deviation; (2) measurement of uncinate process angulation and ethmoid infundibulum width in patients with OMCD was of limited value; (3) the relationship between septal deviation and OMC variation needed further study. It has been indicated that for patients with septal deviation coronal CT study is necessary to evaluate the degree of OMCD.

Adult↗
PubMed1995

An anti-neoplastic glycan isolated from Mycobacterium bovis (BCG vaccine).

Tice substrain BCG is used clinically as an immunotherapeutic agent against superficial bladder cancer. A boiling-water extract of this BCG showed anti-tumour activity against a murine S180 sarcoma model and was fractionated into three fractions, A, B and C, by the use of Sephadex LH-20 chromatography. An anti-tumour glucan, PS1A1, was isolated from fraction PS1A with Sephadex G-75. The molecular mass of PS1A1 was between 65 and 87 kDa by Sephadex G-100 chromatography. The structure of PS1A1 was investigated by one- and two-dimensional NMR spectroscopy and methylation analysis and was demonstrated to be primarily 1-->6-alpha-linked glucose units. We postulate that the repeating unit is: [Formula: see text]

Animals↗
PubMed1995

Identification of a tyrosinase epitope recognized by HLA-A24-restricted, tumor-infiltrating lymphocytes.

A number of Ags recognized by class I-restricted, melanoma-specific T cells have recently been identified. In this report we demonstrated that tumor-infiltrating lymphocytes (TIL) from melanoma patient 1413 recognize a tumor Ag, tyrosinase, in the context of HLA-A24. This Ag had previously been shown to be recognized by an HLA-A24-restricted TIL, TIL 888, as well as HLA-A2-restricted, melanoma-specific T cells isolated from two additional patients. The peptide epitope recognized by TIL 1413 was then identified through the use of sequential deletions of the tyrosinase cDNA, as well as through prediction of HLA-A24 binding peptides based on a previously identified motif. Two peptides, a 9-amino acid peptide (AFLPWHRLF) and an overlapping 10-amino acid peptide (AFLPWHRLFL) containing an additional leucine at the carboxyl terminus, were both recognized by TIL 1413. Anti-peptide-specific CTL could be induced by repeated stimulation of peripheral blood lymphocytes from melanoma patient 1413, and this CTL line specifically recognized both HLA-A24+ B cell lines pulsed with the peptide and HLA-A24+ tyrosinase+ melanoma cells. This peptide thus represents a reagent that may be used to generate melanoma-specific T cells for adoptive immunotherapy, as well as in peptide vaccines for HLA-A24+ melanoma patients.

Amino Acid Sequence↗
PubMed1995

Role of the carbonyl group in thioester chain length recognition by the medium chain acyl-CoA dehydrogenase.

Medium chain acyl-CoA dehydrogenase from pig kidney catalyzes the oxidation of acyl-CoA thioesters to trans-2-enoyl-CoA derivatives with an optimal chain length of about C-8. The binding energy for alkyl-SCoA thioethers shows no such optimum but increases linearly from C-2 to C-16 with a slope of about 390 cal/-CH2 group. In contrast, four types of CoA-thioester analogues (2-aza-acyl-, 3-thia-acyl-, 3-keto-acyl-, and trans-2-enoyl-) yield an incremental binding energy of about 800 cal/-CH2 group until a chain length of about C-8 is reached. The observed binding energy then decreases, or remains constant, with increasing chain length. Studies with dithiooctanoyl-CoA and 2-azadithiooctanoyl-CoA show that the C = S moiety is accommodated poorly by the medium chain dehydrogenase. A model for chain length discrimination, based on the crystal structure of the enzyme [Kim, J. J. P., Wang, M., & Paschke, R. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 7523-7527], is proposed in which hydrogen-bonding interactions between enzyme and thioester carbonyl oxygen atom are maximized at optimal chain lengths. Oversized chains decrease the frequency of effective alignment between enzyme and the C-1 to C-3 region of thioester ligands. Thus the extent of polarization of bound 4-thia-trans-2-enoyl-CoA thioesters decreases sharply with chains longer than C-12.(ABSTRACT TRUNCATED AT 250 WORDS)

Acyl-CoA Dehydrogenase↗