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Biomedical subjects

C Wang

Publications and source records attributed to C Wang.

At least 955 records · Page 53Linked to original sources
PubMed1995

Prospective studies on the relationship between the 50 g glucose challenge test and pregnant outcome.

The 50 g oral glucose challenge test (50gGCT) was performed on 622 pregnant women, and 75 g oral glucose tolerance test (75gGTT) was further done on subjects with screening tests value of > or = 7.78 mmol/L. The results showed that there were 16.56% (103/622) women with screening value of > or = 7.78 mmol/L, among whom, 32 were identified as having gestational impaired glucose tolerance (GIGT) and 12, gestational diabetes mellitus (GDM) by confirmatory test of 75gGTT. The sensitivity of 50gGCT was 42.72%(44/103). The incidences of edema-proteinuria-hypertension syndrome (EPH-syndrome), premature rupture of membranes, fetal macrosomia, operative deliveries and perinatal morbidity were higher in women with GIGT/GDM than in women without GIGT/GDM. It suggests that 50gGCT is an ideal method of screening for GDM and should be performed on all pregnant women.

Adult↗
PubMed1995

[Lupus nephritis in male adults, an analysis of the clinical and pathological features].

Systemic lupus erythematosus is an uncommon disease in men. The clinical and pathological features and prognosis in 50 male patients with lupus nephritis (LN) and 50 age-matched female patients with LN were analysed. The age at which the disease began and the diagnosis was made was generally older in the male. The incidence of LN was higher in the male than in female (P < 0.01). The incidence of types IV and V LN was more common in the male than in female. Type II LN was not found in male patients. Proteinuria over 3.5g/24h and renal failure were more common in the male than in female (P < 0.05). The three most common clinical manifestations in male patients were irregular fever, skin rashes and painful joints. Rashes, hepatomegaly and neuropsychiatric dysfunction were more common in the male than in female. The patients were followed up one to twelve years. The rate of recovery and improvement was lower, but that of relapse and mortality higher in the male than in female.

Adolescent↗
PubMed1995

[The effect of dynorphin A on intracellular cAMP and cGMP contents in spleen cells of burn rats and its relation to immune function].

The lymphocyte response to Con A and IL-2 synthesis was clearly suppressed in rats after thermal injury. In burn rats, the cAMP content in lymphocytes was significantly increased, but cGMP level was not changed. The serum of burn rat could inhibit Con A-induced lymphocyte proliferation and IL-2 production. The burn rat serum could also increase intracellular cAMP concentration. Dynorphin A enhanced lymphocyte proliferation and IL-2 synthesis, increased cAMP level in lymphocytes. Naloxone could inhibit the action of dynorphin A. Moreover, ynorphin A could partly reversed suppression effect of burn serum on lymphocyte proliferation and suppressed the increase of intracellular cAMP content induced by burn and rat serum. Our results suggested that dynorphin A augmented immune function of burn rats, and the action of dynorphin A was mediated by cAMP pathway.

Adjuvants, Immunologic↗
PubMed1995

[A preliminary observation of preventive and blocking effect of Gynostemma pentaphyllum (Thunb) Makino on esophageal cancer in rats].

Gynostemma pentaphyllum (Thunb) Makino is a kind of natural plant growing in the southern provinces of China. In this experiment, rats were given drinks of 2% Gynostemma Pentaphyllum (Thunb) makino aqua boiled solution freely for 2 weeks before administration of carcinogen. Subsequently, the rats were injected with carcinogen (MANA) for 18 weeks and were sacrificed at intervals. The result showed that the number of cases of esophageal epithelial papilloma, the average number of tumor and the incidence of esophageal cancer in the experimental group were lower than those in the control group (MANA only), though no statistical significant difference was found. The initiation of cancer was delayed for 6 weeks. These indicated that Gynostemma Pentaphllum Makino might have some preventive and blocking effect on esophageal cancer in rats.

Animals↗
PubMed1995

[nm23 gene product/NDPK expression and its clinical significance in human colorectal carcinoma].

The expression of nm23 gene product/NDPK was examined immunohistochemically in resected human colorectal carcinomas using anti-NDPK polyclonal antibody. Of the 103 carcinomas tested, 76.7% (79 cases) showed positive staining of nm23/NDPK in the primary lesions. In patients without regional lymph node metastasis, the positive staining rate (90.5%, 38/42) was significantly higher than that in those with nodal involvement (67.2%, 41/61). Inverse relationships were found between nm23/NDPK expression and tumor invasion or the progression of Dukes' staging. Expression of NDPK was positively associated with longer post-operative survival and the relationship was significant. Therefore, our data indicated that nm23 gene plays an important role in lymph node metastasis and invasion in colorectal carcinomas. The expression of nm23 gene product/NDPK may be a useful tool for prognosis of human colorectal carcinomas.

Adenocarcinoma↗
PubMed1995

[The cervical ripening score by trans-perineum ultrasound].

OBJECTIVE: To evaluate cervical ripening in pregnancy at term by trans-perineum ultrasound. METHODS: The cervical length, cervical internal os width, cervical echo intensity, cervical position and distance between fetal presentation and vaginal external os were assessed by trans-perineum ultrasound (transducer 3.5MHz) in 100 cases of normal pregnant women at term. RESULTS: On the basis of Bishop score, the results showed, cervical ripening score > or = 9, 14 cases were in labor, mean parturient time 3.9 +/- 3.1 hours; 5 approximately 8 scores, 54 cases were in labor, mean parturient time 20.8 +/- 3.9 hours; < or = 4 scores, 32 cases in which only 21 cases were in labor, mean parturient time 46.9 +/- 3.9 hours. The results were significantly different among the three groups. CONCLUSION: Ultrasonographic cervical ripening score is an objective noninvasive method for assessment of cervical ripening at term.

Adult↗
PubMed1995

[Effect of acupuncture on the contents of enkephalins in different brain regions of rats with traumatic shock].

The study was carried out on the animal model of traumatic shock which induced by ligating bilateral hind legs. The contents of enkephalins in hippocampus, striatum, hypothalamus, diencephalon and brain stem were determined with radioimmunoassay. The results show that: (1) when traumatic shock occurs, the contents of Met-enkephalin are not obvious change in the above 5 brain regions, and also not significant change after acupuncture; (2) there is a tendency to increase the content of Leu-enkephalin in each brain region described above of shock animal, while it is decreased in hypothalamus after acupuncture. The result suggests that the occurrence of traumatic shock may be related to the functional activities of Leu-enkephalinergic system in the central nervous system; the anti-shock of acupuncture may be through a decrease in the level of central Leu-enkephalin to improve micro-circulation and raise the blood pressure.

Animals↗
PubMed1995

[Swallowing pattern in skeletal Class III malocclusion].

In this research, we compared the swallowing pattern in 33 normal occlusion adults with that in 29 skeletal Class III malocclusion adults, using computerized videofluoscopy. We found that: 1) in skeletal Class III malocclusion patients, the tongue, the hyoid bone and the mandible were in much lower position than those in normal people at postural position. The gap separation between the upper and lower lip was much larger. So was the space between the upper and lower molars. During swallowing, the tongue tip moved upward and backward, and continually moved back along with the backward movement of the tongue dorsum. This was the typical tongue retraction swallowing pattern in Class III malocclusion. The lips kept separation during deglutition, so did the molar region. 2) Abnormal swallowing pattern in skeletal Angle Class III patients was the adaptable change with the dentoalveolar disharmony, while the long time abnormal swallowing could change dentoalveolar structure.

Adolescent↗
PubMed1995

Dental abnormalities and early diagnosis of hyperphosphatasemia.

Dental hard tissue abnormalities have never been described as part of the symptoms associated with hyperphosphatasemia. Fourteen teeth obtained from a young man, who had a mild form of hyperphosphatasemia, were analyzed using scanning electron microscopy (SEM), secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), and infrared (IR) spectroscopy. SEM revealed a thin enamel, presenting a prismatic structure with many pits, and atypical cementum and dentin showing numerous resorption areas. The X-ray diffractograms revealed poorly crystalline hydroxyapatite associated with alpha-tricalcium phosphate and magnesium hydroxide phases. SIMS data showed high Ca concentrations: 40.5 weight % ¿wt%; standard deviation (SD = 0.13) and 42.5 wt% (SD = 1.03) in enamel and dentin respectively, and high Ca/P weight ratios: 2.28 in the enamel, 2.65 in the dentin. The lack of crystallinity may be linked to the high content of proteins and magnesium adsorbed onto apatite. This study demonstrates the need for thorough radiographical and biological investigations for skeletal abnormalities, even in the absence of systemic symptoms, when generalized dental abnormalities of both enamel and dentin are observed.

Adult↗
PubMed1995

[Promoter activity detection and transcription initiation site determination of the D-xylose isomerase gene of Streptomyces diastaticus strain No.7 M1033].

The DNA segment of the Streptomyces diastaticus strain No.7 M1033 D-xylose Isomerase gene, from -192 to +581 bp according to the translation start site (tss), was cloned in Streptomyces promoter-probe plasmid pIJ4083 from recombination plasmid pUB1 and its M13 subclone S1 respectively. The protoplasts of S. lividans TK24 were transformed with the recombinant, and then detected the promoter activity by measuring the catethol dioxygenase expression. Results of S1 mapping of total RNA of S. di. M1033 indicatedthat: the transcription initiation site of D-XI gene was 40bp upstream the coding region; there was another gene encoded on the antisense strand upstream D-XI gene, with a 114-nucleotide sequence separating their coding regions. According to its DNA sequence, we believed it was the xylulose kinase gene. Data from quantitive S1 mapping also suggested that transcription of the two genes was induced by D-xylose and repressed by glucose.

Aldose-Ketose Isomerases↗
PubMed1995

Translation of hepatitis C virus genome.

Translation of the human hepatitis C virus (HCV) RNA genome occurs by internal ribosome entry through the 5' end (5' noncoding region) in a cap-independent fashion. The relatively long stretch of this noncoding region contains multiple initiation codons that are apparently not used for translation. Translation of the HCV polyprotein is initiated instead from an AUG located at nt 342. Using computer-assisted analysis (and subsequently substantiated by enzymatic probing), a complex secondary and tertiary structure of the 5' noncoding region (5'NCR) has been predicted. Based on an RNA folding model proposed by Brown et al. (1992), a detailed mutational analysis carried out identified the key secondary structural regions that are of functional significance in translational control. Maintenance of a helical structural element relevant to an oligopyrimidine tract is essential for internal initiation. A putative coaxial stacking or a pseudoknot structure upstream of the initiator AUG seems to be central to an internal ribosome entry site (IRES)-mediated translation of the HCV RNA genome.

Hepacivirus↗
PubMed1994

Development of a model for the delta opioid receptor pharmacophore. 1. Conformationally restricted Tyr1 replacements in the cyclic delta receptor selective tetrapeptide Tyr-c[D-Cys-Phe-D-Pen]OH (JOM-13).

A series of analogues of the conformationally restricted delta opioid receptor selective tetrapeptide Tyr-c[D-Cys-Phe-D-Pen]OH (JOM 13) was prepared in which the conformationally labile Tyr residue was replaced with several less flexible tyrosine analogues. Among these tyrosine analogues were the bicyclic structures 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid (HO-Tic), 2-amino-6-hydroxytetralin-2-carboxylic acid (Hat), and 2-amino-5-hydroxyindan-2-carboxylic acid (Hai) in which rotations about the C alpha-C beta and C beta-C gamma bonds are restricted due to cyclization of the side chain to the backbone. Also examined were analogues in which tyrosine was replaced with either trans-3-(4'-hydroxyphenyl)proline (t-Hpp) or cis-3-(4'-hydroxyphenyl)proline (c-Hpp), residues in which rotations about C alpha-C beta, but not C beta-C gamma, are restricted. Both the t-Hpp1 and c-Hpp1 analogues displayed delta receptor binding affinity similar to the parent Tyr1-containing peptide, while the D-Hat1, L-Hat1, and L-Hai1 analogues exhibited somewhat lower affinity. The results observed for the t-Hpp1 and c-Hpp1 analogues are particularly significant since these two residues have little accessible conformational space in common. Since the binding conformation of residue 1 must be included in this limited conformational intersection, its elucidation is facilitated. Bioassay results from guinea pig ileum and mouse vas deferens preparations are in general agreement with the binding results; however some potency discrepancies are observed. These discrepancies may reflect different selectivities among delta receptor subtypes for the analogues or may represent differing efficacies among these conformationally restricted peptides. The conformational properties of the parent tetrapeptide and the residue 1-modified analogues were studied by molecular mechanics computations. All these peptides share a common rigid tripeptide cycle with a single energetically preferred backbone conformation and three different conformers of the D-Cys, D-Pen disulfide bridge, two of which are observed in the solid state and in aqueous solution, as previously determined from X-ray crystallography and 1H NMR spectroscopy data (Lomize, A; et al. J. Am. Chem. Soc. 1994, 116, 429-436). All the peptides have similar sets of low-energy conformations of their common flexible elements, the Phe3 side chain and the peptide group between the first residue and the rigid tripeptide cycle. However, possible conformations of the first residue differ and depend on the covalent constraints incorporated into the side chain.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1994

Activity-dependent mobilization of the adhesion molecule polysialic NCAM to the cell surface of neurons and endocrine cells.

The alpha-2,8-linked sialic acid polymer (PSA) on the neural cell adhesion molecule (NCAM) is an important regulator of cell surface interactions. We have examined the translocation of PSA-NCAM to the surface of cultured cortical neurons and insulin secreting beta cells under different conditions of cell activity. Endoneuraminidase N, an enzyme that specifically cleaves PSA chains, was used to remove pre-existing PSA from the plasma membrane and the re-expression of the molecule was monitored by immunocytochemistry. Punctate PSA immunostaining was restored on the surface of 68% of neurons within 1 h. This recovery was almost completely prevented by tetrodotoxin, suggesting that spontaneous electrical activity is required. K+ depolarization (50 mM) allowed recovery of PSA surface staining in the presence of tetrodotoxin and this effect required the presence of extracellular Ca2+. Rapid redistribution of PSA-NCAM to the surface of beta cells was observed under conditions that stimulate insulin secretion. Ca2+ channel inhibition decreased both PSA-NCAM expression and insulin secretion to control, non-stimulated levels. Finally, subcellular fractionation of an insulin-secreting cell line showed that the secretory vesicle fraction is highly enriched in PSA-NCAM. These results suggest that PSA-NCAM can be translocated to the cell surface via regulated exocytosis. Taken together, our results provide unprecedented evidence linking cell activity and PSA-NCAM expression, and suggest a mechanism for rapid modulation of cell surface interactions.

Animals↗
PubMed1994

Direct measurement of the influenza A virus M2 protein ion channel activity in mammalian cells.

The influenza A virus M2 integral membrane protein has an ion channel activity which is thought to play an essential role in the uncoating process of influenza virus in infected cells and, for some strains of influenza virus, in maintaining the hemagglutinin in its pH neutral form during transport through the trans Golgi network. To demonstrate directly that the M2 protein forms an ion channel in mammalian cells, the M2 protein was expressed in CV-1 cells by using an SV40-M2 recombinant virus and the whole cell membrane currents were recorded. It was found that the whole cell current was activated by low pH and inhibited by the M2 ion channel-specific blocker, amantadine hydrochloride. Expression of an altered M2 protein that contains a deletion of four residues in the transmembrane domain (M2-del28-31) and that when found in influenza virus confers amantadine resistance, resulted in a current that was activated by hyperpolarization of the membrane, was pH insensitive, and was resistant to block by amantadine. The data obtained in mammalian cells for the wild-type M2 and M2-del28-31 protein ion channel activities were very similar to those obtained when using the heterologous oocyte expression system.

Amantadine↗
PubMed1994

The range and nature of flexion-extension motion in the cervical spine.

OBJECTIVE: The full flexion to full extension angular ranges of motion (ROM) from C2 to C7 were measured for 78 normal subjects and 50 cervical myelopathic cases to examine the cervical motions for these two groups in a Chinese population. METHODS: Measurements were all taken from standard lateral radiographs. RESULTS: The normal group showed an average total ROM slightly less than in Western subjects, but a similar distribution of motion throughout C2 to C7. The proportion of motion at levels C4:C5 and C5:C6 were functions of the total ROM, the greatest proportion of motion being at C4:C5 for low (< 50 degrees) total ROM and moving to C5:C6 for high (> 90 degrees) total ROM. The myelopathic group showed a similar but less clearly established pattern of motion to this. A significantly lower average total ROM than in the normal group was also found. CONCLUSIONS: This work suggests that the reduction in total angular ROM concomitant with aging results in the emphasis of cervical flexion-extension motion moving from C5:C6 to C4:C5, both in normal cases and those suffering from cervical myelopathy.

Adult↗
PubMed1994

Cyclosporine nephrotoxicity: attenuation by an antioxidant-inhibitor of lipid peroxidation in vitro and in vivo.

The exact mechanisms by which cyclosporine (CsA) causes renal injury is not known. The possibility that reactive oxygen species (ROS) may play a role, since CsA induces renal microsomal lipid peroxidation and reduces glutathione levels, was investigated by examining whether administration of an antioxidant attenuates CsA-induced nephrotoxicity. One of three groups of uninephrectomized rats received vehicles, another CsA 25 mg/kg/day and the third, CsA plus antioxidant lazaroid (U-74389 G) 20 mg/kg/day, for 8 weeks. CsA-induced functional and structural derangements were accompanied by a significant induction of renal cortical lipid peroxidation (thiobarbituric acid reactive substances and conjugated diene). Administration of lazaroid significantly suppressed CsA-induced lipid peroxidation and provided significant functional and structural protection. That lazaroid affords renal functional protection against CsA in the rat was again demonstrable in a crossover study. To examine the relation between CsA nephrotoxicity and lipid peroxidation, cell culture studies were undertaken. CsA induced renal epithelial (LLC-PK1) cell injury (LDH release) as well as lipid peroxidation and degradation (prelabeled 3H arachidonic acid release). Lazaroid prevented CsA-induced cell injury and limited lipid alterations. These new findings--that an antioxidant inhibitor of lipid peroxidation limits CsA-induced renal toxicity in vitro and in vivo--suggest a pathogenic role for ROS-mediated lipid peroxidation in CsA-induced renal toxicity. Antioxidant therapy may minimize CsA-induced renal toxicity in humans.

Animals↗