Biomedical subjects

J Wu

Publications and source records attributed to J Wu.

At least 811 records · Page 45Linked to original sources

PubMed1998

The side-to-side differences of bone mass at proximal femur in female rhythmic sports gymnasts.

This cross-sectional study examined the side-to-side differences of the bone mineral density (BMD) at proximal femora in female rhythmic sports gymnasts (RSGs). The hypothesis on which the study is based is that gymnasts use a different leg in take-off (left leg) and in landing (right leg) and therefore differ in the loading for the left and right legs. The gymnasts made up two groups: the regular group, which consisted of 15 regular players who had trained for about 28 h/week, and the substitutes group, which consisted of 8 substitute players who had trained for about 12 h/week. The control group consisted of 10 nonathletic college women who had not participated in any kind of regular sports activity. BMD (g/cm2) was measured in three hip sites using the XR-26 dual-energy X-ray absorptiometer scanner. Muscle strength at knee extensors (EXT) and flexors (FLX) was examined using an isokinetic dynamometer (CYBEX6000), and the vertical ground reaction force was determined with a force platform during take-off and landing movements. In the regular players, the BMDs of the left leg were significantly higher than those of the right leg at the femoral necks, greater trochanters, and Ward's triangles (p < 0.01 to approximately 0.005). The side-to-side differences were 4.7 to approximately 9.6%. Regarding the strength parameters, the left side was greater than the right side significantly at EXT 60 degrees/s (p < 0.01), although the overall side-to-side difference was small. In the substitutes, the BMDs at the three sites mentioned above were also higher in the left leg than the right, but the side-to-side difference was statistically significant only at Ward's triangles (93%, p < 0.05). The side-to-side difference of strength was not significant. In the controls, there were small left-to-right differences of the BMDs, ranging from -1.8 to 0.5%, which was significantly lower than in the regular players at each site. The overall average strength measurements were larger in the right leg than in the left except at the 120 degrees/s. The side-to-side difference was statistically significant at EXT 30 degrees/s and 60 degrees/s (p < 0.05). The peak force was greater in take-off than in landing, and the unit time force during take-off was significantly greater than that during landing (p < 0.001). In conclusion, regarding the side-to-side difference of the BMD at proximal femora, our results demonstrate: that the left leg for take-off had higher measurements than the right leg for landing in both gymnasts' groups, which accounts for the vertical ground reaction force during take-off being greater than that during landing; that the difference in the regular players group was greater than that in the substitute group, which can be explained because the regular players practiced much more than the substitutes did; and that there was no difference in the control group.

Adolescent↗

PubMed1998

The prospects of hepatic drug delivery and gene therapy.

Liver targeted therapy is designed to deliver a substance preferentially to the organ in order to increase the accumulation, improve the therapeutic effect and reduce toxicity to other organs. The aim of selective targeting is to deliver a substance to a specific cell type in the liver. A variety of vehicles have been designed and further modified for selective targeting of therapeutics to the liver. The targeting properties and strategies of commonly used agents, such as liposomes, microspheres and recombinant chylomicrons, are discussed. Viral and non-viral vectors, such as cationic liposomes, reconstituted chylomicron remnants, adenoviruses, adeno-associated viruses, retroviruses, and SV-40, are currently being evaluated for the delivery of DNA to the liver. New developments in improving the targeting efficiency of the available vectors while avoiding their disadvantages have made their use in clinical trials of various genetic disorders possible. For viral hepatitis, antisense and ribozyme techniques are being employed with selective targeting approaches. A commonly employed current strategy for targeting hepatocellular carcinoma cells is to make the tumour cells convert non-toxic 'prodrugs' to toxic metabolites in situ, achieving a high concentration of the toxic product in the local milieu, while avoiding systemic toxicity. Although gene therapy itself is in its infancy, some encouraging results have been developed in studies of familial hypercholesterolaemia, haemophilia, alpha1-antitrypsin deficiency and Crigler-Najjar syndrome. The potential strengths as well as the problems with these studies are discussed.

Journal Article↗

PubMed1998

Far UV photolysis of uracil and cytosine in phosphate solution.

The photolysis of nucleobases, nucleosides and nucleotides (NA) was enhanced by phosphate under irradiation of medium pressure mercury lamp (MPML). Uracil and Cytosine in phosphate solution were selected to study the mechanism of phosphate effect. Photoproducts were produced in the irradiated uracil and cytosine of phosphate solution which have been isolated by anion exchange resin. Ultraviolet irradiation (190-220nm) of uracil in 0.05 mol/dm3 phosphate buffered solution at pH 8-9 leads to the production of a novel compound C4H5N2O6P which has been identified by UV, 1H-NMR spectroscopy and LC/MS/MS. The formation mechanism of the photoproduct and the kinetics were studied.

Amino Acids↗

PubMed1998

Real-time CT fluoroscopy: usefulness in thoracic drainage.

OBJECTIVE: The purpose of our study was to review the application of real-time CT fluoroscopy in the drainage of localized pleural and mediastinal collections. SUBJECTS AND METHODS: Between July 1996 and August 1997, 20 patients with 10 loculated pleural effusions, two mediastinal fluid collections, and 12 focal pneumothoraces were treated using CT fluoroscopy. The patient population was 25-77 years old and included 14 men and six women. Methods of drainage included using a modified Seldinger technique with a guidewire and serial dilators in 10 patients and a single-stick trocar technique in the remaining 14. Total room time, procedure time, and CT fluoroscopy time were recorded. RESULTS: All 24 collections were successfully evacuated using either real-time or interrupted real-time CT fluoroscopy. The real-time capability of CT fluoroscopy proved particularly useful for rapid placement of drainage tubes in patients who were unable to cooperate with breathing instructions and in patients who had a narrow window of access. Average total room time was 65 min. Average procedure time was 32 min, and average CT fluoroscopy time was 143 sec. CONCLUSION: CT fluoroscopy permits rapid drainage of intrathoracic collections. CT fluoroscopy is a particularly useful treatment for patients who are unable to perform breath-holding or in whom access to the drainage site is difficult.

Drainage↗

PubMed1998

Effect of 10% phosphoric acid conditioning on the efficacy of a dentin bonding system.

The efficacy of a commercial total-etch wet-bonding dentin bonding system and the effect of conditioning using 10% phosphoric acid both on the Ca-content in the substrate dentin and on the efficacy of the experimental contraction gap-free dentin bonding system were evaluated by measuring the wall-to-wall polymerization contraction gap width of a commercial light-activated resin composite filled into a cylindrical cavity prepared in extracted human dentin. The Ca-content in the dentin was measured with an EDS. Complete marginal adaptation was obtained only in the experimental contraction gap-free dentin bonding system group. The Ca-content in the dentin was rapidly reduced by the 10% phosphoric acid conditioning. It was concluded that the dentist should not decalcify the dentin cavity wall possibly by using a dentin conditioner such as 10% phosphoric acid because the resin composite paste is apt to separate easily from the decalcified dentin cavity wall during polymerization.

Acid Etching, Dental↗

PubMed1998

[Establishment of transgenic cell line CHL-3A4 and its metabolic activation].

OBJECTIVE: To establish a model cell line CHL-3A4 to study metabolic pathways for some genotoxic chemicals. METHODS: Complimentary DNA (cDNA) of cloned cytochrome P450-3A4 gene in human liver tissue was transferred to Bluescript M13 vector with reverse transcription polymerase chain reaction (RT-PCR) and DNA recombinant techniques. Restriction endonuclease map analysis and sequencing of partial cloned fragment proved that CYP3A4 cDNA was cloned into Bluescript M13 vector. Then, recombinant expression plasmid pREP9-3A4 was constructed in eukaryotic cell and transfected into Chinese hamster CHL cells. RESULTS: It was proved that a CHL-3A4 transgenic cell line was established, which could lead metabolic activation for aflatoxin B1 (AFB1), sterigmatocystin (STC) and cyclophosphamide (CPA). CONCLUSION: The CHL-3A4 cell line established did express human cytochrome P450 3A4 and could lead metabolic activation for three genotoxic chemicals AFB1, STC and CPA.

Animals↗

PubMed1998

Enhancing effects of beta-endorphin on glutamate neurotoxicity.

AIM: To study the effect of beta-endorphin (beta-End) on monosodium glutamate (MSG)-induced neurotoxicity (GNT). METHODS: Image analysis of neuronal areas and determination of mitochondrial membrane protein-bound Ca2+ and intracellular free Ca2+ ([Ca2+]i) were used. RESULTS: beta-End aggravated MSG-induced neuronal injury in arcuate nucleus of hypothalamus in a dose-dependent manner in the range from 0.5 to 5.0 mg.kg-1. MSG-induced increase in mitochondrial membrane protein-bound Ca2+ was enhanced when treated with beta-End 2 g.L-1. MSG-induced elevation in [Ca2+]i in single neuron was also augmented from 320 +/- 84 to 589 +/- 78 nmol.L-1 by the treatment with beta-End 2 g.L-1. CONCLUSION: beta-End enhanced GNT via aggravating the disruption of intracellular Ca2+ homeostasis induced by MSG.

Animals↗

PubMed1998

[The effect of sex steroids on human ovarian granulosa cell apoptosis].

OBJECTIVES: To study the molecular mechanism of human follicular atresia by exploring the effects of estrogen, androgen on human granulosa cell (GC) apoptosis. METHODS: Ovarian GC DNA fragments of both atretic and developing follicles before and after estrogen (1 microgram/ml), androgen (1 microgram/ml) treatments were analysed by agarose gel electrophoresis. The expression of bcl-2 mRNA was also determined by northern blotting in GC of developing follicle after sex steroids addition. RESULTS: Internucleosomal DNA cleavage occurred in granulosa cells in atretic follicles and after androgen treatment. In granulosa cells of developing follicles, estrogen treatment increased the expression of bcl-2 mRNA by 45%, while androgen treatment downregulated the expression of bcl-2 mRNA by 35%. CONCLUSION: Androgens increase apoptotic DNA fragmentation, and decrease the expression of bcl-2 mRNA in GC of developing follicles, while estrogens produce the opposite effect. Therefore, expression of bcl-2 may be involved in the mechanism of follicular development and atresia.

Adult↗

PubMed1998

[Distribution of morphine in acute morphine-treated rats].

The distribution of morphine in acute morphine-treated rats was studied by immunohistochemistry (PAP). Samples were examined for morphine distribution and localization in internal organs at 10-160 min after intraperitoneal injection of morphine. The results showed that morphine was distributed in the heart, hepatocytes, epithelial cells of the bile canalicular cells in liver, spleen, kidney, adrenal glands, stomach parietal cells, small intestinal villus, pancreas islet, sublingual glands and submandibular glands. Morphine was found in the cardiac tissue, liver, spleen, pancreas islet, small intestinal villus at 10 min after injection and in the cardiac tissue, stomach parietal cells at 160 min after injection. The cause of the postmortem the distribution of morphine in internal organs at different times after injection was discussed. The results of this study may be used as a basis for the choice of samples for the forensic toxicological analysis.

Animals↗

PubMed1998

[A retrospective study of neurogenic pulmonary edema following intracranial injury without open wound].

To find factors that relate to the occurrence of neurogenic pulmonary edema(NPE) following intracranial injury without open wound, thirty-founr autopsies on such cases were studied retrospectively. The rate of NPE in the 34 cases was 41.18%, and it was 44.44% in those aged 10 to 49. The rate of NPE in the persons who died immediately or 0-6 hours after injury was 41.18%, and in those who died 7-48 hours after injury, 41.18% too. The rate of NPE was 69.23% for the cases with only one site of bleeding and 23.81% for ones with multiple sites of bleeding. These findings suggest that the occurrence of NPE is not related with the duration of time after head injury or the location of brain injury, but it is related with the severity of brain injury.

Adolescent↗

PubMed1998

[The effect of a vaccine made from 39kd hydrophobic outer membrane protein of Leptospira interrogans on neurohumoral and red cell immunity function of the guinea pigs].

A randomized control trial was conducted to determine the immunoprotective efficacy of OmpL39. 36 guinea pigs were divided into OmpL39 group, whole leptospiral cell vaccine (WLCV) group, other proteins of Leptospira group, and negative control group (normal saline, NS). The results showed that all the guinea pigs of infected OmpL39 and WLCV still survived, but all the control guinea pigs died. Immunoprotective efficacy was 100% for OmpL39 and WLCV. OmpL39 levels were similar to WLCV levels and higher than controls (P < 0.05). These suggested that OmpL39 could be used as important immunoprotective antigen to develop the genetic vaccine of the targeting delivery system. Also it was observed that OmpL39 could produce 100% immunoprotective efficacy, have higher MAT level (> 1:3200) and regulate 5-HT, 5-HIAA, DA, NE. The 5-HT, DA, NE concentration was lower and 5-HIAA was higher than that of controls after stimulating the guinea pigs with OmpL39 (P < 0.05). The results suggested that OmpL39 genetic vaccine could produce immunity function and have an active effect on absorbing inflammation and protecting organs and tissues. Besides, the red cell immunity efficacy of the guinea pigs was changed during immunity response and the RBC-C3b RR and the RBC-ICR were increased. The RFER was increased; the RFIR was decreased. RFER/RFIR was remarkably higher than that of control (P < 0.05). These suggested that OmpL39 could increase red cell immunity function.

Animals↗

PubMed1998

[Cloning and orientation of cefoperazone resistance gene on plasmid pFC in E. coli HX88108].

Cefoperazone resistance gene (CPZr) has been cloned from plasmid pFC of E. coli HX88108 using the vector pMB9 (TCr, 5.3 kb). The plasmid pFC DNA was partially digested with Sau3A I, and its 1-2 kb fragments were ligated into BamH I site of vector plasmid pMB9. The recombinant DNA was then transformed into E. coli DH5 prepared using calcium chloride. CPZ resistant bacterial colonies were selected on the agar SOB plates containing CPZ (40 micrograms/ml). The resistance to CPZ could be stably reserved in generation after generation. The recombinant plasmids which encoded CPZ resistance were designated pFL11, pFL25, pFL33, pFL82, pFL86 and pFL102. Rapid small-scale preparation of plasmid and DNA restrication enzyme analysis were used for identification of bacterial colonies. Five plasmids DNA physical maps have been established. Comparison of recombinant plasmids maps with pFC map confirmed that the CPZr gene was oriented between nucleotide no. 3200 bp and no. 4800 + 40 bp of plasmid pFC total sequence. Its molecular weight was about 1.6 kb. There were EcoR I, Sma I and Pvu II sites within CPZr gene.

Cefoperazone↗

PubMed1998

[Quantitive analysis of 5-hydroxytryptamine levels on edges of incised skin of rats].

To find index for early diagnosis of antemortem wound, the authors used the ICS analysis in a quantitive study of 5-hydroxytryptamine(5-HT) levels on rat's incised-skin antemortem wound in comparison with the postmortem wound inficted at various intervals. The results showed that the 5-HT increased significantly at 5 min, reached a peak at 15 min and decreased at 60 min on antemortem wounds. The 5-HT levels of antemortem groups were prominently high (more than 40%, P < 0.05) as compared with those of postmortem group and the levels of 5-HT on the wounds of postmortem groups were higher (35.77%, P < 0.05) than those of controls as well. The authors suggest that in the cases where the levels of 5-HT are as high as 40% on the edges of the injured skin, the injury should be considered an antemortem wound.

Animals↗

PubMed1998

[Morphologic changes of red blood cells in various conditions under scanning electron microscope].

To study the changes of RBC in various conditions, blood clots elapsed 6 days in water and air and bloodstains stored in variant time were observed under Scanning Electron Microscope (SEM). The results showed that the morphology of RBC elapsed 6 days in water and air seemed to retain their integrity. They were measured 5, 48-5, 88 microns in diameter, whereas the RBC in the bloodstains stored 14 years were obviously disfigured and some appeared membrane cracking. However, the structure of RBC membrane was well recognized under the SEM. The morphological changes under the SEM and the forensic significance of the RBC were discussed.

Blood Stains↗

PubMed1998

[MMC conditioning regimen (Melphalan, MeCCNU and cyclophosphamide) followed by allogeneic peripheral blood stem cells transplantation for chronic myeloid leukemia].

This paper reports 3 cases of allogeneic peripheral blood stem cell transplantation (Allo-PBSCT) for the patients with chronic myeloid leukemia (CML). The patients received MMC preparative regimen with high dose chemotherapy (Melphalan 170 mg/m2, p.o. on Day-5, MeCCNU 400 mg/m2, p.o. on Day-4, and Cyclophosphomide 60 mg/kg/day, i.v. on Days-3 and -2). The HLA-identical sibling donors received filgrastim (rhG-CSF) for mobilization at a dose of 300 micrograms/day for 6 days. Leukaphereses were done at the 6th day of mobilization. A median of 8000 ml (2 times total blood volume) of blood was processed the collecting: 2.5-4.5 x 10(8)/kg MNC, 12.8-20.0 x 10(6)/kg CD34+ cells (including 4.8-7.5 x 10(6)/kg CD34+CD33-, 8.0-13.0 x 10(6)/kg CD34+CD33+), and 3.5-4.3 x 10(5)/kg CFU-GM. Cyclosporin A and methotrexate were used for GVHD prophylaxis. Hematopoitic function recovered as for 14-20 days to > 0.5 x 10(9)/L of neutrophil count, and for 16-34 days to > 20 x 10(9)/L of platelet count. At day + 100, chromosome analysis of bone marrow cells showed that complete chimera without ph1 positive chromosome in Cases 1 and 3, and a partial chimera with 73% donor karyotype in Case 2. All patients now are in disease free survival. No episode of acute graft versus host disease (GVHD) developed. It was concluded that HLA matched sibling allogeneic PBSCT result in rapid hematopoitic reconstitution and the MMC conditioning regimen is effective both in leukemic cells eradication and in immunosuppression for stem cells engraftment, and the drug related toxicity could be tolerated by patients.

Adult↗

PubMed1998

[Genetic polymorphisms of the D19S400 locus in Chinese Zhuang, Bai, Tibetan, Mongolian populations].

Four Chinese populations have been studied by the polymerase chain reaction (PCR) for obtaining the data on genetic polymorphisms of D19S400 locus in four populations in China and for evaluating its use in forensic practice. EDTA-blood samples were collected from 356 unrelated individuals in Nanning (Zhuang), Dali (Bai), Lasa (Tibetan); Hailaer (Mongolian), DNA samples were extracted by Phenol/Chloroform method. The PCR products were analyzed by PAG vertical electrophoresis. Nine alleles and 42 genotypes were found at D19S400 locus in these four populations. The heterozygosity was between 0.75 and 0.89 and the discriminating power between 0.9274 and 0.9625. Significant difference was observed in the distribution of allele frequencies among the four Chinese populations. According to the results obtained in this study, D19S400 locus is a useful marker for individual indentification, paternity testing and for genetics study.

Alleles↗

PubMed1998

[Apoptosis of human oocytes is age-related].

OBJECTIVE: To study the morphological characteristics, and rate of apoptosis of human oocytes in relation to age. METHODS: 206 oocytes were aspirated from antral follicles 4-6 mm in diameter from 58 patients who had surgery done for ovarian cysts. These oocytes were incubated in Ham's F10 with 10% fetal cord serum (FCS) for 48-120 hours, and examined under inverted microscope every 6-8 hours to see their morphological changes. In situ end-labeling (ISEL) of fragmented DNA was used to confirm apoptosis. RESULTS: The characteristics of apoptosis are: (1) shape change of oocytes. (2) oocyte shrinkage. (3) chromatic condensation and apoptotic body formation. (4) internucleosomal DNA cleavage was shown by ISEL. Apoptosis occurred in 13.9% (women aged 21-30), 37.7% (women aged 31-40), and 61.5% (women aged 41-50) respectively. The rate of apoptosis was much higher in women aged 41-50 than that in the other two groups. CONCLUSION: The rate of apoptosis of human immature oocytes cultured in vitro is much higher in older women aged 41-50 than in those aged 21-40, which may account for the poor response to superovulation stimulation and low oocyte quality in older women.

Adult↗

PubMed1998

[Development of human preantral follicles and oocytes maturation in vitro].

OBJECTIVE: To study the development of human preantral follicles and oocytes maturation by in vitro culture. METHODS: Preantral follicles obtained from follicular fluid during egg retrieval in an in vitro fertilization (IVF) program was first incubated in Ham's F10 with 15% fetal cord serum (FCS). After 28 days, the medium was supplemented with different doses of hMG, mature follicular fluid (mFF) and epidermal growth factor (EGF) by orthogonal design. Induction of final maturation was completed in the presence of human menopasual gonadotropin hMG and mFF. RESULTS: Development from preantral to antral follicles was found within 6-12 days of culture. With increasing time, the proportion of follicles with diameters of more than 300 micrograms increased at 21-28 days of culture (P < 0.005). The maximal number of oocytes extrusion and first polar body formation occurred in the presence of 1501U/L hMG, 40% (v/v) mFF and 6 micrograms/L EGF. CONCLUSIONS: Follicular fluid obtained during egg retrieval in an IVF program was found to contain many preantral follicles which could develop into antral follicles with extrusion of oocytes in culture, and the oocytes matured in vitro. However, the course of development of follicles and maturation of oocytes in vitro is quite different from that in vivo.

Cells, Cultured↗