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Biomedical subjects

F Song

Publications and source records attributed to F Song.

At least 73 records · Page 4Linked to original sources
PubMed1999

A method for identifying differentially expressed genes in rare populations of primary human hematopoietic cells.

Differential display (DD) is widely employed for identifying uniquely expressed genes within two different cell populations. While potentially powerful, DD is problematic because apparent positive clones require time-consuming verification which may be made even more difficult if only small amounts of starting material are available. We have devised a screening approach to address these issues in primary human hematopoietic cells. Candidate clones are identified in a slot-blot format and verified by 'Virtual Northern' blot analyses using globally amplified cDNA as the verification probe. This method is fast, and since it requires only approximately 0.2 microg of total RNA, it is particularly useful when only limited amounts of study tissue are available.

Blotting, Northern↗
PubMed1999

Systematic reviews and meta-analysis: a structured review of the methodological literature.

OBJECTIVE: To systematically review methods for systematic review/meta-analysis in order to identify the different methodological and statistical methods that have been proposed. A summary of the main findings is presented here, with emphasis given to health services research topics. METHODS: A thorough systematic search for methodological papers was carried out using a variety of methods, including the use of electronic databases. Approximately 1000 potentially relevant references were identified, a number of them from education, psychology and sociology. RESULTS: After briefly reviewing the procedural methods required to carry out a review, and the basic statistical methods used to combine study estimates, less established methods are discussed. These include methods for dealing with publication bias, meta-regression, meta-analysis of individual patient data, the synthesis of non-randomized evidence alone and in combination with randomized studies. Bayesian modelling and economic evaluation through meta-analysis. Recommendations for meta-analytical practice are given; these are either distilled from previous guidelines, or constructed where there appears to be a broad consensus across the literature. CONCLUSIONS: It is hoped that this review will provide a consistent and comprehensive, but concise, description of the methods available for synthesizing evidence, that it will promote better quality reviews of the results of health services research and identify specific areas which require methodological development.

Bayes Theorem↗
PubMed1999

Regulation of the mucosal immune response.

Infectious diseases continue to exact an extensive toll on populations living closest to the equatorial regions of the globe. A substantial proportion of these infections gain access to the host via the mucosal tissues. Thus, the development of new vaccines that enhance mucosal immunity is considered to be of paramount importance in order to prevent or limit the impact of these infections. Mucosal immune responses must discriminate between commensal flora within the lumen and potential pathogens. These responses are highly adapted to induce protection without excessive amounts of inflammation. The balances that regulate mucosal immune and inflammatory responses have to be understood if effective mucosal immunity is to be induced through local immunization. This review will summarize some of the unique properties of mucosal immune responses and focus on recent advances that have significantly influenced our understanding of the regulation of immune and inflammatory responses following infection.

Animals↗
PubMed1999

Quality-assessed reviews of health care interventions and the database of abstracts of reviews of effectiveness (DARE). NHS CRD Review, Dissemination, and Information Teams.

OBJECTIVES: Database of Abstracts of Reviews of Effectiveness (DARE) (http:@www.york.ac.uk/inst/crd/) at the NHS Centre for Reviews and Dissemination provides a unique international resource of structured summaries of quality-assessed reviews of health care interventions. These reviews have been identified from searches of electronic databases and by hand-searching journals. This paper describes and summarizes the DARE database, including the topic areas covered and the review methods used. METHODS: The first 480 structured abstracts on the DARE database were summarized. Data were extracted from each database field and coded for analysis. RESULTS: Most of the systematic reviews investigated the effectiveness of treatments: 54% investigated the effectiveness of medical therapies, and 10% assessed surgical interventions. Around two-thirds used meta-analytic methods to combine primary studies. The quality of the reviews was variable, with just over half of the reviews (52%, n = 251) having systematically assessed the validity of the included primary studies. Narrative reviews were more likely than meta-analyses to reach negative conclusions (42% vs. 25%, p = .0001). The 21 reviews that reported drug company funding were more likely to reach positive conclusions (81% vs. 66%, p = .15). CONCLUSION: The DARE database is a valuable source of quality-assessed systematic reviews, and is free and easily accessible. It provides a valuable online resource to help in filtering out poorer quality reviews when assessing the effectiveness of health technologies.

Abstracting and Indexing↗
PubMed1999

[Effects of long-term morphine exposure on the cAMP system and c-Fos phosphorylation in differentiated SH-SY5Y cells].

OBJECTIVE: To further understand the effects of long-term morphine exposure on the cAMP system and c-Fos phosphorylation in differentiated SH-SY5Y human neuroblastoma cells. METHODS: Cellular changes of cAMP, PKA and c-Fos were detected by protein competitive conjunction, enzyme activity and isotope incorporation methods respectively. RESULTS: (1) Long-term exposure (2 min-36 h) to morphine (100 mumol/L) could induce the biphasic changes in cAMP contents. Treament for 2 min to 1 h, morphine caused rapid and siginificant decrease of the cAMP level and then gradully recovered and apparently increased at 36 h. At that time, naloxone added to the incubation media caused an overshoot of cellular cAMP; (2) Long-term exposure to morphine could also induce the biphasic changes in cytosolic PKA activity. This is consistent with the changes of cAMP during the chronic treatment of cells with morphine. But no changes were observed in membrane PKA activity; (3) In morphine dependent-like cells decreased c-Fos phosphorylation level was observed. PKA inhibitor could significantly inhibit this change; (4) Concomitant administration of naloxone could block the changes in PKA activity and c-Fos phosphorylation described above. CONCLUSIONS: The up-regulation of cAMP system in differentiated SH-SY5Y cells may be involved in the development of morphine dependent and in morphine dependent-like SH-SY5Y cells and PKA was suggested to regulate c-Fos dephosphorylation through activating phosphatase and then activate some genes transcription, which might be one of the important mechanism regardingas cellular adaptive responses underlying dependence to opioid drugs.

Cyclic AMP↗
PubMed1999

[The 1. 54 microm laser and upconversion luminescence of YELPP noncrystalline induced by 969 nm LD laser].

In this paper, the absorption of Er3+, Yb3+ penta-phosphate noncrystalline (YELPP) was measured and the basic spectral parameters were calculated. Adopting the longitudinal-pump method with a domestic diode laser (LD), we achieved CW 1.5 microm chipped laser in China for the first time. The power of 1.5 microm laser was quite stable. The target of 1.5 microm laser reached the international level of early 1990s' in this field. In addition, the up-conversion luminescence was measured under the condition that 1.5 microm laser was either oscillating or not. The relationship between 1.5 microm chipped laser and up-conversion luminescence was analyzed initially.

English Abstract↗
PubMed1998

Search for human T-lymphotropic virus type I carriers among northeastern Chinese.

Human T-lymphotropic virus type I (HTLV-I) is thought to be the causative agent of adult T-cell leukemia/ lymphoma (ATL). This virus infection is endemic in southwestern Japan, parts of Africa and the Caribbean Islands. We examined sera of 1645 subjects of Liaoning province, northeastern China to detect HTLV-I carriers in an effort to reveal the migratory route taken by the early Japanese (Jomon people). As a result, all sera were found to be negative as tested by particle-agglutination (PA), immunofluorescence (IF), enzyme-linked immunoabsorbent (ELISA) and Western blotting methods. This suggests that the Jomon people, who are thought to have brought HTLV-I to the Japan archipelago tens of thousands of years ago, did not come from northeast China.

Adult↗
PubMed1998

Antimicrobial prophylaxis in colorectal surgery: a systematic review of randomized controlled trials.

BACKGROUND: A systematic review was carried out to assess the relative efficacy of antimicrobial prophylaxis for the prevention of postoperative wound infection in patients undergoing colorectal surgery. METHODS: MEDLINE, EMBASE, the Cochrane Trials Register and the references cited in retrieved studies were searched to identify relevant trials published between 1984 and 1995. RESULTS: Some 147 relevant trials were identified. The quality of trials has improved over the past 12 years. The results confirm that the use of antimicrobial prophylaxis is effective for the prevention of surgical wound infection after colorectal surgery. There was no significant difference in the rate of surgical wound infections between many different regimens. However, certain regimens appear to be inadequate (e.g. metronidazole alone, doxycycline alone, piperacillin alone, oral neomycin plus erythromycin on the day before operation). A single dose administered immediately before the operation (or short-term use) is as effective as long-term postoperative antimicrobial prophylaxis (odds ratio 1.17 (95 per cent confidence interval (c.i.) 0.90-1.53)). There is no convincing evidence to suggest that the new-generation cephalosporins are more effective than first-generation cephalosporins (odds ratio 1.07 (95 per cent c.i. 0.54-2.12)). CONCLUSION: Antibiotics selected for prophylaxis in colorectal surgery should be active against both aerobic and anaerobic bacteria. Administration should be timed to make sure that the tissue concentration of antibiotics around the wound area is sufficiently high when bacterial contamination occurs. Guidelines should be developed locally in order to achieve a more cost-effective use of antimicrobial prophylaxis in colorectal surgery.

Anti-Bacterial Agents↗
PubMed1998

[Water-soluble ginsenosides in American ginseng].

OBJECTIVE: To have further comprehension of American Ginseng on the basis of its water-soluble components. METHOD: The water suspension of 80% methanol extract of American Ginseng was sequentially extracted with ethyl ether and n-butyl alcohol. The saccharides in the water-soluble portion were removed by macro-reticular resin column, and three compounds were obtained by silica-gel column chromatography. Their structures were confirmed on the basis of spectral analysis(IR, NMR, MALDI-MS) melting points and optical degrees. RESULT: Three compounds were identified as malonyl ginsenosides Rb1, ginsenoside Rb1 and Re respectively. Among them Rb1 and Re are known, while malonyl ginsenoside Rb1 was isolated from American Ginseng for the first time. Its structure was elucidated as (3 beta, 12 beta)-20-[(-6-O-beta-D- glucopyranosyl-beta-D-glucopyranosyl)oxy]-12-hydroxylammar-24-en-3-yl-O- [6-O-(carboxyacetyl)-beta-D-glucopyranosyl)]-beta-D-glucopyranoside. CONCLUSION: Water-soluble ginsenosides were isolated from the water-soluble extract of American Ginseng suggesting that malonyl ginsenosides exist both in American Ginseng and Ginseng.

Ginsenosides↗
PubMed1998

[Application of capillary non-gel sieving electrophoresis to the analysis of short tandem repeat in phenylalanine hydroxylase gene and gene diagnosis of phenylketonuria].

OBJECTIVE: To establish a sensitive, accurate and reliable method for analysis of short tandem repeat (STR) markers for gene diagnosis, capillary electrophoresis (CE) was used for analysis of a polymorphic tetranucleotide (TCTA)n in intron 3 of the phenylalanine hydroxylase (PAH) gene. METHODS: Capillary non-gel sieving electrophoresis (CNGSE) system was used to analyze PCR products of PAH STR among 61 normal Chinese individuals and 6 phenylketonuria (PKU) families. RESULTS: The PCR fragments that differ 4 bp from each other were well separated by CNGSE. Ten alleles were identified, with a continuous distribution from 224 bp to 260 bp. The largest allele (260 bp) was first detected in Chinese population. The alleles frequencies were calculated and PIC is 0.738. The genotypes of PAH STR of total 80 Chinese people were also analyzed and the heterozygosity is 75%. We used this procedure to PAH gene linkage analysis in 6 PKU families, in which pathogenic gene could be affirmed in 3 families, including one case of prenatal diagnosis. CONCLUSIONS: In comparison with denaturing polyacrylamide gel electrophoresis, CE is an accurate, rapid, automatic and with high resolution analytical tool. CE in combination with PCR is a hopeful technique and might be widely used for gene diagnosis of genetic diseases in the future.

Alleles↗
PubMed1998

[Comparative study of portal-systemic shunt rate measured by formula and radioactive method].

OBJECTIVE: To establish a new simple and useful formula for the observation of portosystemic shunt. METHOD: In the same animals and the same patients, portosystemic shunt rate was measured individually by the two different methods, i.e. formula and radio active method. Using the results of the radio active method as a gold standard, the reliability of the formula method was assessed tested. RESULT: In 11 normal dogs, the portal-systemic shunt rate measured by the formula and radio active methods was 7.03% and 7.55% respectively (P > 0.05). In 9 portosystemic shunting model dogs, the portosystemic shunt rate calculated from the two methods was 48.64% and 51.11% respectively (P > 0.05). In 22 patients with portal hypertension, the preoperative results from the formula and radioactive methods were 52.38% and 55.86% respectively (P > 0.05). In these patients, the postoperative portal-systemic shunt rate was 26.22% and 31.00% respectively (P > 0.05). CONCLUSION: These results fully testified the reliability of the formula method we had established.

Adult↗
PubMed1998

[Modulation of cGMP levels, soluble guanylate cyclase and phosphodiesterase activities in brain of morphine-dependent mice].

By inducing morphine dependence in mice, the changes of cGMP contents, phosphodiesterase (PDE) and soluble guanylate cyclase (sGC) activities and their phosphorylation regulated by protein kinase A (PKA) were observed. It was found that: (1) cGMP contents in cerebellum, striatum, hippocampus and cerebral cortex were significantly lower. (2) The sGC activities were apparently decreased in cerebellum and striatum. In the striatum and cerebral cortex the sGC activities and phosphorylation levels in vitro were significantly increased and were inhibited by PKA inhibitor. (3) The PDE activities showed no change in cerebellum and hippocampus, but in striatum and cerebral cortex PDE activities and phosphorylation levels in vitro were significantly increased and were inhibited by PKA inhibitor. (4) These changes described above were not observed in mice treated with naloxone 30 min prior to daily morphine injection. Our data indicate that the decrease of cGMP contents occurred generally in brain regions of morphine-dependent mice. The decrease of cGMP contents in cerebellum and hippocampus may be due to the decrease of sGC activities, but the decrease of cGMP contents in striatum and cerebral cortex may be mainly due to the increase of PDE activity. Both sGC and PDE activities were regulated by PKA.

Animals↗