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Biomedical subjects

J Hu

Publications and source records attributed to J Hu.

At least 397 records · Page 22Linked to original sources
PubMed1998

[Study on voltammetric behaviour of clozapine and its single-sweep oscillopolarography].

A sensitive reduction peak of clozapine is obtained by single-sweep oscillopolarography in 0.1 mol.L-1 H2SO4 solution. The peak potential is -0.95 V (vs. SCE). The peak current is directly proportional to the concentration of clozapine with a detection limit of 2.0 x 10(-8) mol.L-1. The voltammetric behaviour of clozapine and its mechanism of electrode reaction have been studied by linear-sweep and cyclic voltammetry and pulse polarography etc. The reduction process is irreversible with adsorptive characteristics. The number of electrons transferred n is 2. The electron transfer coefficient alpha is 0.62. Its behaviour obeys Langmuir adsorption isotherm. The adsorption coefficient beta is 1.91 x 10(6) L.mol-1. The energy of adsorption delta G0 = -35.83 kJ.mol-1. The method has been applied to the determination of clozepine in tablet and urine.

Antipsychotic Agents↗
PubMed1998

[The determination of ligustilide in Ligusticum chuanxiong Hort. by supercritical fluid extraction].

In this study, a systematic method was used to optimize the supercritical fluid extraction (SFE) of ligustilide in Ligusticum chuanxiong Hort. Overall five variables (pressure, temperature, static extracting time, modifier concentration and CO2 dynamic extracting volume) were considered. To reduce the loss of volatile substance, a solid-liquid trap was developed for SFE collection. Comparisons were made on the solvent trap for SFE. The extracts were analyzed by high performance liquid chromatography (HPLC) with ultraviolet absorbance detection. The recoveries of 99.34% (RSD 1.70%) and 92.11% (RSD 5.72%) were achieved for solid-liquid trap and solvent trap, respectively. SFE conditions: temperature 40 degrees C, pressure 27.6 MPa, static extraction 3 min, dynamic extraction 7 ml and 0.1 ml CHCl3 as modifier. HPLC conditions: The HPLC column (3.9 mm x 150 mm) was packed with Nova-Pak C18(4 microns). Naphthalene was used as internal standard. The mobile phase was methanol--10% isopropyl alcohol solution (53:47 v/v). The detection wavelength was 280 nm and the flow rate was 0.8 ml.min-1.

4-Butyrolactone↗
PubMed1998

[The use of orthognathic surgery in the treatment of maxillofacial fractures].

35 cases with bony malunion following maxillofacial fractures had been treated successfully by orthognathic surgery technique. Mini-titanium plate had been used in the rigid internal fixation. The article introduced the surgical method and discussed some primary principals which should be paid attention during operation.

Adolescent↗
PubMed1998

[Effect of RNA against hepatic fibrosis in rabbits infected with Schistosoma japonicum].

AIM: To study the effect of ribonucleic acid (RNA) against schistosomal hepatic fibrosis in rabbits. METHODS: 54 rabbits were randomly and equally divided into normal group, infected group, and RNA group. On the 40, 70, 100th day after RNA i.m. injection, 6 rabbits from each of the above 3 groups were killed and their plasma and liver were examined by way of biochemistry and pathology. RESULTS: Compared with the infected group the collagen fiber of liver in RNA group was less produced, the hepatic cellular nucleolus was enlarged, the number of rough endoplasmic reticulum (RER) and the granules on the RER were increased, the collagen fiber around fat-storing cell was decreased, the content of hyaluronic acid in plasma, the hydroxyproline level in liver tissue, the percentage of collagen fiber distribution and the collagen fiber level in liver tissue of RNA group were significantly reduced. CONCLUSION: RNA might play a role in the prevention of schistosomal hepatic fibrosis.

Animals↗
PubMed1998

[Immunohistochemical study of Fas ligand in liver tissue of chronic hepatitis B virus infection].

To evaluate the role of apoptosis on liver injury of chronic hepatitis B, we studied the expression of Fas ligand and HBsAg immunohistochemically. Sixty-eight liver biopsy samples from patients with type B chronic liver disease were immunostained for Fas ligand and thirty-two of which were immunostained for HBsAg.35/68(51.47%) cases showed FasL immunoreactive in liver-infiltrating mononuclear cells, and more expression of FasL were found in cytoplasm of hepatocytes. Both were closely linked to the degree of inflammation in liver(P = 0.008 and P = 0.011, respectively). But the expression of FasL had no close relationship with that of HBsAg in liver tissue (P > 0.05). These findings suggest that apoptosis caused by CTL through Fas-mediated pathway plays an important role in liver cell injury by hepatitis B virus infection. At the same time, FasL-positive hepatocytes may express cytotoxic activity and eliminate themselves by both fratricide and suicide; 'Bystander effect' can be used to account for the difference expression between FasL and HBsAg.

Adult↗
PubMed1998

[The localization of FasL mRNA in liver tissues of chronic hepatitis B].

To study the expression of FasL mRNA in liver tissues of CHB, we investigated FasL mRNA by in situ hybridization in liver tissues from patients with chronic hepatitis B. FasL oligonucleotide probes were synthesized and labeled with DIG-Oligonucleotide 3'-End Labeling Kit. FasL mRNA was found in cytoplasm of liver-infiltrating mononuclear cells, hepatocytes and some sinus cells. FasL mRNA-positive hepatocytes were present mainly at the edges of 'piecemeal necrosis(PN)' and 'bridging necrosis (BN)'. These results demonstrated that human hepatocytes themselves can express FasL in chronic hepatitis B. We deem that FasL-positive hepatocytes might express cytotoxic activity and eliminate Fas-positive hepatocytes by both 'fratricide' and 'suicide'. These results also emphasize that apoptosis caused by CTL through Fas-mediated pathway may play an important role in CHB.

Apoptosis↗
PubMed1998

[Purification and properties of antifungal protein X98III from Bacillus subtilis].

Bacillus subtilis BS-98 is one of the antagonistic strains strongly against plant fungal pathogens such as Physalospora piricola Nose. The antifungal protein was purified by ammonium sulphate precipitation and column chromatography on Sephadex G-100 and DEAE-cellulose, and it was named X98III. Molecular weight of X98III is 59,000 by SDS-PAGE and PI value is 4.50 by PAG-IEF, respectively. X98III was demonstrated as glycoprotein and lipoprotein by CAM (cellulose acetate membrane) electrophoresis and special staining. We estimated it contains 6% saccharides by using DNS methods. This protein was also found to be thermostabale and partially sensitive to proteinases. The amino acid analysis of the protein X98III showed that it comprises of 11 different amino acids and Glu, Tyr, Cys are the abundant amino acids. No Asp, Phe and Met were found. Purified X98III has strong inhibiting activity against the pathogens of Physalospora piricola, Phoma asparagi, etc. The antifungal mechanism of X98III was mainly disintegration of the cell wall to make the hyphae abnormal and the spores germinate abnormally or can not germinate at all.

Amino Acids↗
PubMed1998

[Identification of Radix and Rhizoma Rhei by UV and TLC].

This paper deals with the identification of radix and rhizoma of 24 species (varieties) of Genus Rheum by UV and TLC. This results provide authentic methods for the identification of Radix and Rhizoma Rhei.

Chromatography, Thin Layer↗
PubMed1998

[Study of the circular dichroism for tribasic complex of amine derivative of beta-cyclodextrindien-Cu2+ -benzoic acid].

The circular dichroism spectra of beta-cyclodextrindien, beta-cyclodextrindien-Cu2+ complex, beta-cyclodextrindien-benzoic acid complex, tribasic complex of beta-cyclodextrindien-Cu2+ -benzoic acid were determined by using JASCO J-20C automatic recording spectropolarimeter. The attribution of the bands obtained were made according to the order of orbit energy of Cu2+ complex and benzoic acid, and the coordination structure of tribasic complex of amine derivative of beta-cyclodextrindien-Cu2+ -benzoic acid were decided acording to the structure character of Cu2+ complex and KAJART sector rule of inclusion complex of beta-cyclodextrindien with aromatic compounds.

Amines↗
PubMed1998

Immunophenotypic characterization of simian immunodeficiency virus-infected dendritic cells in cervix, vagina, and draining lymph nodes of rhesus monkeys.

Significant progress has been made in understanding the biology of heterosexual transmission of HIV by utilizing the simian immunodeficiency virus (SIV)/rhesus monkey animal model. Our previous studies have shown that SIV-infected cells within the stratified squamous epithelium of the vagina have a dendritic morphology. However, the type of cell infected was not conclusively determined. The purpose of the present study was to immunophenotype the SIV-infected cells in the lower reproductive tract and genital lymph nodes of the female rhesus monkey. Vagina, cervix, and iliac lymph node from eight chronically SIV-infected adult female monkeys were examined for this study. None of the animals had histologic evidence of opportunistic infections or genital tract pathogens other than SIV. Combined in situ hybridization and immunohistochemistry were used to detect SIV RNA and to determine the immunophenotype of SIV-infected cells in tissue sections and cytospin preparations of cells from the tissues. We now show that SIV-infected cells were most common in iliac lymph node and that the majority of infected cells in the lymph node were T lymphocytes. SIV-infected macrophages, Langerhans' cells, and dendritic cells were also found in the lymph node. SIV-infected cells were found within the epithelium and lamina propria of the vagina. Although most of the infected cells were T cells, a significant proportion (approximately 40%) of the SIV-infected cells in cytospin preparations from explant cultures of vagina and cervix were Langerhans' cells. SIV-infected T cells in the lower genital tract were commonly associated with focal mononuclear cell infiltrates. SIV-infected macrophages were rarely found in the genital tract. The present study provides the first direct demonstration that Langerhans' cells and dendritic cells in the genital tract and lymph nodes are infected with SIV in vivo. Thus, dendritic cells, in general, and Langerhans' cells, in particular, are important reservoirs for HIV/SIV replication in vivo.

Animals↗
PubMed1998

Comparative genomic hybridization of esophageal and gastroesophageal adenocarcinomas shows consensus areas of DNA gain and loss.

Relatively little is known about the genetic changes that occur in esophageal and gastroesophageal adenocarcinomas. To provide a survey of relative DNA gains and losses in these cancers, we microdissected 15 primary human esophageal and gastroesophageal adenocarcinomas to enrich for cancer cells and subsequently performed comparative genomic hybridization. Eighteen regions of high-level amplification were detected in 11 tumors, with 8p23, 17q21, and 18p11 showing four, three, and two such events, respectively. The most common minimal regions of gain were 8q24 (8/15), 20q (7/15), 17q21 (7/15), and 7p 1-15 (7/15 ). The most common minimal regions of loss were 5q 12-21 (8/15), 4q10-24 (5/15), 4p (5/15), and 18q (3/15). These results implicate the well-characterized oncogenes MYC (8q24) and ERBB2 (17q21), and they predict the involvement of additional oncogenes on 8p23, 20q, and chromosome 7 in the pathogenesis of these cancers. Chromosomes 4 and 5 are frequent targets of deletion in these tumors and may harbor novel tumor suppressor genes.

Adenocarcinoma↗
PubMed1998

Physical assignment of two porcine microsatellites to the short arm of chromosome 1 by modified DISC-PCR.

Direct in situ single copy PCR (DISC-PCR) was modified to increase signal detection efficiency and physically assign two porcine microsatellites (MS), Sw552 and Sw137, to chromosome 1p at Flpter 0.1-0.2 and Flpter 0.01-0.2, respectively. These are the first two MS localized to chromosome 1p by an in situ method. The modifications of the DISC-PCR procedure included use of buffered formalin and pepsin as pre-reaction treatments, and tetramethylbenzidine (TMB) for signal detection. The detection efficiency of the modified method is twofold higher than that of the original technique.

Animals↗
PubMed1998

Mechanical Properties of Large Arteries in Mother and Fetus during Normal and Diabetic Pregnancy.

> Objective: To assess the influence of diabetes mellitus on the mechanical wall properties of large maternal and fetal arteries in pregnant women. Methods: Prospective serial monitoring of arterial wall characteristics, using ultrasonic phase-locked tracking of vessel diameters and oscillometric brachial blood pressure measurements. Ten pregnant women with insulin-dependent diabetes mellitus and 15 with gestational diabetes were studied and compared with 20 women in uncomplicated gestation. Results: In women with uncomplicated pregnancy, the stiffness index and the elastic modulus of the maternal aorta were lower (both P < 0.05), whereas the pulse amplitude and the strain were higher (both P < 0.05) in the 12th gestational week than in the 6th week postpartum. These differences did not appear in pregnancy complicated by insulin-dependent diabetes. In early gestation, higher aortic stiffness index and elastic modulus (both P < 0.05) and lower pulse amplitude and strain (both P < 0.05) were recorded in gravidae with insulin-dependent diabetes compared with nondiabetic pregnant women; those with gestational diabetes were not detected in early pregnancy. No intergroup or intragroup differences of stiffness index and pulse amplitude were found in the carotid artery in corresponding gestational ages. In the fetal aorta, the pulse wave velocity increased during the third trimester of normal gestation (P < 0.05) but not in insulin-dependent diabetic pregnancy. Conclusion: The difference found concerning the aortic stiffness between women with insulin-dependent diabetes during pregnancy and those with uncomplicated pregnancy might be interpreted as an altered cardiovascular adaptation to pregnancy in women with diabetes.

Journal Article↗
PubMed1997

Development of an epithelium-specific expression cassette with human DNA regulatory elements for transgene expression in lung airways.

The efficient expression of therapeutic genes in target cells or tissues is an important component of efficient and safe gene therapy. Utilizing regulatory elements from the human cytokeratin 18 (K18) gene, including 5' genomic sequences and one of its introns, we have developed a novel expression cassette that can efficiently express reporter genes, as well as the human cystic fibrosis transmembrane conductance regulator (CFTR) gene, in cultured lung epithelial cells. CFTR transcripts expressed from the native K18 enhancer/promoter include two alternative splicing products, due to the activation of two cryptic splice sites in the CFTR coding region. Modification of the K18 intron and CFTR cDNA sequences eliminated the cryptic splice sites without changing the CFTR amino acid sequence, and led to enhanced CFTR mRNA and protein expression as well as biological function. Transgenic expression analysis in mice showed that the modified expression cassette can direct efficient and epithelium-specific expression of the Escherichia coli LacZ gene in the airways of fetal lungs, with no detectable expression in lung fibroblasts or endothelial cells. This is the first expression cassette which selectively directs lung transgene expression for CFTR gene therapy to airway epithelia.

Animals↗
PubMed1997

A case-control study of diet and lung cancer in northeast China.

A case-control study involving interviews with 227 lung-cancer cases and 227 matched hospital controls was conducted in Heilongjiang Province in northeast China to examine the influence of dietary factors on the risk of developing lung cancer. Lung-cancer cases were all incident cases judged to be suitable candidates for tumor removal by surgery. Controls were selected among hospitalized patients with non-neoplastic and non-lung disease. The overall male lung-cancer risks associated with cigarette smoking were similar to those reported in other Chinese studies but quite low compared to risks in Western countries. However, the subjects in this study were relatively young (average age 53.2), had started to smoke on average at a relatively old age (21.3 years), and only smoked an average of 18.7 cigarettes per day. Lung-cancer risk was not strongly associated with any of the nutrients examined, when all cases were compared to all controls. However, the data were suggestive of differences in the relationship of diet to risk among smokers and non-smokers. Cautious interpretation is required because of the wide confidence intervals due to limited sample size. Among the smokers, only higher beta-carotene was associated with estimates suggesting a lowered risk. Among non-smokers, the evidence suggested that increased vegetable consumption might reduce risk, consumption of any fruit might reduce risk but beta-carotene was unrelated to risk. The differences observed in the relationship of diet to lung-cancer risk between Chinese smokers and non-smokers warrant further study.

Case-Control Studies↗