Adaptive changes in insulin secretion by islets from neonatal rats raised on a high-carbohydrate formula

Artificial rearing of neonatal rats on a high-carbohydrate (HC) milk formula resulted in the immediate onset of hyperinsulinemia. This study examines, in islets of 12-day-old HC rats, adaptive changes that support the hyperinsulinemic state. Increases in plasma glucagon-like peptide-1 (GLP-1) levels and islet GLP-1 receptor mRNA supported increased insulin secretion by HC islets. Isolated HC islets, but not mother-fed (MF) islets, secreted moderate amounts of insulin in a glucose- and Ca(2+)-independent manner. Under stringent Ca(2+)-free conditions and in the presence of glucose, GLP-1 plus acetylcholine augmented insulin release to a larger extent in HC islets. Levels of adenylyl cyclase type VI mRNA and activities of protein kinase A, protein kinase C, and calcium calmodulin kinase II were increased in HC islets. A tenfold increase in norepinephrine concentration was required to inhibit insulin secretion in HC islets compared with MF islets, indicating reduced sensitivity to adrenergic signals. This study shows that significant alterations at proximal and distal sites of the insulin secretory pathway in HC islets may support the hyperinsulinemic state of these rats.

[Expression and synergism of two cry insecticidal protein genes in Pseudomonas fluorescens]

Several engineered Pseudomonas fluorescens(Pf) strains were constructed mainly based on a Pseudomonas plasmid pJMS6 alpha-lac and two insecticidal crystal protein genes of Bacillus thuringiensis, cry1Ac and cry2Aa, and the host Pf strain, P303, which was with highly antifungal activity to some plant disease fungi and colonizing ability on a wide range of plants. The DNA introduction was confirmed by PCR-RFLP and Southern blot. The 132 kD insecticidal protein was detected in IPP101 and IPP202 by SDS-PAGE and rhombic insecticidal protein crystals of them were observed through electron microscope, also indicating that cry1Ac gene was highly expressed. The results of insecticidal bioassay indicated that IPP101 was more toxic than IPP201, and IPP202 was the most toxic among the 3 strains. LC50 to the neonates of cotton boll worm(Helicoverpa armigera) were 0.02604, 0.00812 and 0.00186 mL/g feed, consecutively. In IPP202, two gene products showed significant synergism, with the co-toxicity coefficient of 332.8.

Indirect comparison in evaluating relative efficacy illustrated by antimicrobial prophylaxis in colorectal surgery

This paper aims to explore the potential usefulness and limitations of indirect comparisons in evaluating the relative efficacy of interventions. From a systematic review of antimicrobial prophylaxis in colorectal surgery, we identified 11 sets of randomized trials that can be used to compare antibiotics both directly and indirectly. The discrepancy between the direct and the indirect comparison is defined as the absolute value of difference in log odds ratio. The adjusted indirect comparison has the advantages that the prognostic factors of participants in different trials can be partially taken into account and more uncertainty be incorporated into its result by providing a wider confidence interval. However, considerable discrepancies exist between the direct and the adjusted indirect comparisons. When there is no direct comparison, the adjusted indirect method may be used to obtain some evidence about the relative efficacy of competing interventions, although such indirect results should be interpreted with great caution. Further empirical and methodologic research is needed to explore the validity and generalizability of the adjusted indirect comparison for evaluating different interventions.

The causes, consequences and detection of publication bias in psychiatry

OBJECTIVE

Publication bias threatens the validity of published research, although this topic has received little attention in psychiatry. The purpose of this article is to produce a systematic overview of the causes and consequences of publication bias and to summarize the available methods with which it is detected and corrected.

METHOD

Empirical evidence for the existence of publication bias is reviewed and the following methods are applied to an illustrative case example from psychiatry: funnel plot analysis; the 'file drawer method'; linear regression techniques; rank correlation; 'trim and fill'.

RESULTS

Small studies are particularly susceptible to publication and related bias. All methods to detect publication bias depend upon the availability of a number of individual studies with a range of sample sizes. Unfortunately, large numbers of studies of varying sample size are not always available in many areas of psychiatric research.

CONCLUSION

Where possible researchers should always test for the presence of publication bias. The problem of publication bias will not be solved by anything other than a prospective trials register.

Modelling publication bias in meta-analysis: a review

Meta-analysis is now a widely used technique for summarizing evidence from multiple studies. Publication bias, the bias induced by the fact that research with statistically significant results is potentially more likely to be submitted and published than work with null or non-significant results, poses a threat to the validity of such analyses. The implication of this is that combining only the identified published studies uncritically may lead to an incorrect, usually over optimistic, conclusion. How publication bias should be addressed when carrying out a meta-analysis is currently a hotly debated subject. While statistical methods to test for its presence are starting be used, they do not address the problem of how to proceed if publication bias is suspected. This paper provides a review of methods, which can be employed as a sensitivity analysis to assess the likely impact of publication bias on a meta-analysis. It is hoped that this will raise awareness of such methods, and promote their use and development, as well as provide an agenda for future research.

Factors influencing the expression of Fas and Fas ligand on newborn murine keratinocytes and fibroblasts

OBJECTIVE

To investigate the expression of Fas, FasL mRNA and proteins on keratinocytes and fibroblasts, and the influence by retinoid acid (RA) and dexamethasone (Dex).

METHODS

RNase protection assay and flow cytometry were used.

RESULTS

Fas mRNA was expressed on neonatal murine keratinocytes and was up-regulated by all-trans retinoid acid and down-regulated by Dex. RA and Dex also increased the Fas protein expression on keratinocytes. Newborn murine keratinocytes express FasL mRNA, which was up-regulated by RA and Dex, while its protein expression was moderately induced by RA. Newborn murine fibroblasts also expressed Fas and FasL mRNA, which were up-regulated by the RA and Dex.

CONCLUSIONS

The results indicated that RA and Dex might regulate apoptosis of keratinocytes and fibroblasts via the Fas-FasL system.

[Identification of cry-type genes of 31 Bacillus thuringiensis isolates and analysis of their expression product]

In this study, cry-type gene of 31 isolates of Bt had been identified using PCR-RFLP identification system, and SDS-PAGE analysis and bioassay had been performed. 25 strains containing cry1 type gene express 130-150 kD protein and 16 of them contain cry1I gene, which codes 80 kD protein and is larvicidal to both lepidopteran and coleopteran species. 15 strains contain both cry1 and cry2 type gene; 10 strains contain unknown cry-type gene; 6 strains don't contain seven identified cry-type gene. Result of bioassay shows that the strains containing both cry1 and cry2 gene have high toxicity to lepidopteran order, 7 of them are strongly insecticidal to Pristiphora beijingensis and Lymantria dispar larvae; the strains containing cry1Ab + 1Ac + 2A or cry1Aa + 1Ac + 2A have high activity to Heliothis armigera; no cry gene, no activity. It is indicated that identification of cry-type gene and its analysis of SDS-PAGE protein can predict insecticidal activity of Bt isolates, and it is no pertinency between cry-type gene and serotype of Bt strain.

[Activities of superoxide dismutase in Xanthomonas oryzae pv. oryzae and its induction]

The activities of superoxide dismutase(SOD) in Xanthomonas oryzae pv. oryzae were determined to demonstrate the correlation of SOD activities with the bacterial virulence. In liquid culture, SOD activities of the tested strains reached the maxima at the end of lag phase and then declined. The virulent strain PXO99A showed higher SOD activities than the avirulent strain PXO99A (pBUavr Xa10.F1). Analysis on the subcellular location indicated that SOD activities detected from the cytoplasm and periplasm were over 70% and 20%-30% of the total, respectively. Treatment of the bacterial culture for 1 h with exogenous O2- at concentration of 50-800 mumol/L induced SOD activities of both the strains. The treatment with 200 mumol/L resulted in the highest SOD activities. The effect of exogenous O2- on SOD induction was more significant in 12 h-culture than in 24 h-culture, and more notable for the virulent strain PXO99A. The treatment with exogenous O2- resulted in significantly decreased survival rate off both the strains. The decreases of survival rate were greater in 24 h-culture than in 12 h-culture, and more significantly for the virulent strain than for the avirulent one.

[Laryngostroboscopy in the monitoring of precancerous lesion of vocal cord and in canceration tracing]

OBJECTIVE

To evaluate the value of laryngostroboscopy in the monitoring of precancerous lesion of vocal cord and in the canceration tracing.

METHODS

Fifty-two cases of precancerous lesion of vocal cord were examined under Laryngostroboscope. The modifications of mucosal wave and amplitude of vocal cord vibration were observed. All cases were monitored for 1-6 years.

RESULTS

The mucosal wave was weak in 45 of 52 cases (86.3%) and the amplitude of vocal cord vibration was weak in 4 of 52 cases (9.6%) with precancerous lesions. However, the mucosal wave disappeared and the amplitude of vocal cord vibration weakened in all 14 cases with early glottic cancer.

CONCLUSION

Laryngostroboscopy can be used in diagnosis of glottic precancerous lesion and distinguishing it from the early glottic cancer. It is also an effective means of canceration tracing.

Staphylococcal enterotoxin B stimulates expansion of autoreactive T cells that induce apoptosis in intestinal epithelial cells: regulation of autoreactive responses by IL-10

T cell responses to self Ags and normal microbial flora are carefully regulated to prevent autoreactivity. Because IL-10-deficient mice develop colitis, and this response is triggered by luminal flora, we investigated whether IL-10 regulates the ability of microbial Ags to induce autoreactive T cells that could contribute to intestinal inflammation. T cells from wild-type mice were primed with staphylococcal enterotoxin B (SEB) in vitro, which induced an autoreactive proliferative response to syngeneic feeder cells. The cells were predominately CD3+ and CD4+. T cells from IL-10-deficient mice were constitutively autoreactive, and SEB priming enhanced this further. The autoreactive, proliferative response of T cells from wild-type mice was suppressed by IL-10 in the primary or secondary culture, and this effect was inhibited by neutralizing Abs to the IL-10R. To confirm that an autoreactive repertoire was expanded after SEB priming, we used CBA/J mice (Mls-1a) in which autoreactive T cells recognizing the endogenous viral superantigen are depleted (Vbeta6, 7, 8.1 TCR-bearing cells). However, SEB rescued these autoreactive T cell repertoires. Adding anti-MHC class II Ab blocked the autoreactive response. SEB-primed splenic or colonic T cells also induced apoptosis in syngeneic intestinal epithelial cells that was blocked significantly by IL-10. Thus, microbial Ags have the potential to abrogate self tolerance by stimulating autoreactive T cells that become cytolytic to target cells. IL-10 plays a protective role in maintaining self tolerance after microbial stimulation by preventing the activation of T cells that contribute to epithelial cell damage.

Publication bias and the integrity of psychiatry research

The cornerstone of evidence-based medicine is the belief that good quality research should form the basis of clinical practice and decision-making (Muir Gray, 1997). Psychiatry has kept abreast of this movement (Geddes et al. 1997) and claims have been made that randomized-controlled trials (the highest quality primary evaluative research) can be used to justify 65% of routine clinical decisions (Geddes et al. 1996). However, it is largely published research that forms the ‘knowledge base’ of the evidence movement. A fundamental difficulty arises when published research results are a biased sample of all research results – published and unpublished. Publication bias presents one such threat and has been much discussed in wider healthcare (Easterbrook et al. 1991; Dickersin & Min, 1993; Dickersin, 1997), but has been little discussed or researched in psychiatry, despite the fact that psychiatry is likely to be at least as prone to publication bias as other specialities.

Total syntheses of (+/-)-anchinopeptolide D and (+/-)-cycloanchinopeptolide D

The first synthesis of (+/-)-anchinopeptolide D (4) has been accomplished in seven steps in 10% overall yield from octopamine hydrochloride (17), N-(Boc)glycine (16), and 5-amino-2-hydroxypentanoic acid (22). The key step is the aldol dimerization and hemiaminal formation of alpha-keto amide 26, which gives primarily protected anchinopeptolide D 27 under kinetically controlled conditions. Cycloanchinopeptolide D (31) has been prepared by the unprecedented head-to-head photodimerization of the two hydroxystyrylamides of 4 using the hydrophobic effect in water to force the two side chains into close proximity so that [2 + 2] cycloaddition is faster than trans to cis double bond isomerization. Coupling of amine 21 with pyroglutamic acid affords the naturally occurring tripeptide 35, which had been assigned glutamic acid structure 34.

Synthesis of the N-((1E)-alkenyl)-(2Z,4Z)-heptadienamide side chain of salicylihalamide A and apicularens A and B

[reaction: see text] The unstable N-((1E)-alkenyl)-(2Z,4Z)-heptadienamide side chain of salicylihalamide A (1) and apicularens A and B (3 and 4) has been prepared in one pot by the addition of (1Z,3Z)-hexadienylcuprate, prepared in situ from EtLi, CuBr.SMe2, and acetylene, to a (1 E)-alkenyl isocyanate.

Expression of IL-10 receptors on epithelial cells from the murine small and large intestine

The appearance of chronic intestinal inflammation in IL-10 knockout mice suggests IL-10 may inhibit adverse responses to luminal antigen. Moreover, this inflammation is associated with an increase in class II MHC molecule expression on intestinal epithelial cells. Thus, the role of IL-10 regulation in epithelial cell function was investigated. Using RT-PCR, it was shown that intestinal epithelial cells express mRNA for both subunits of the IL-10 receptor-signaling complex. In addition, biotinylated IL-10 was shown to bind to both cultured and freshly isolated intestinal epithelial cells prepared from the small or large intestine. This binding appeared specific as it was blocked by neutralizing antibodies to IL-10 but not the isotype control. Moreover, an excess of native IL-10 also inhibited the binding of radiolabeled IL-10. To evaluate whether IL-10 mediated any functions through this receptor, epithelial cells were cultured with IL-10 alone or with IFN-gamma plus IL-10. IL-10 alone had no detectable effects on epithelial cell growth or their expression of class II MHC molecules but it did antagonize the effect of IFN-gamma on the viability of cultured cells. In addition, IL-10 blocked the IFN-gamma-induced expression of class II MHC molecules on cultured epithelial cells. These results suggest that IL-10 binds to a specific receptor on intestinal epithelial cells and may regulate the contribution of epithelial cells to the inflammatory and immune response in the digestive tract.

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.

Enhancement of ultraviolet photorefraction in highly magnesium-doped lithium niobate crystals

We investigate UV photorefraction in Mg-doped LiNbO(3) crystals. Strong UV photorefraction is achieved in highly Mg-doped LiNbO(3) crystals with high two-wave mixing gain, fast response, and low noise. It is also demonstrated experimentally that so-called damage-resistant dopants such as Mg are damage resistant only in the visible and that they will enhance photorefraction in the UV.

Beds, mattresses and cushions for pressure sore prevention and treatment

OBJECTIVES

To assess the effectiveness of pressure relieving beds, mattresses and cushions (support surfaces) in the prevention and treatment of pressure sores.

SEARCH STRATEGY

Searches of 19 databases, hand searching of journals, conference proceedings, and bibliographies.

SELECTION CRITERIA

Randomised controlled trials evaluating support surfaces for the prevention or treatment of pressure sores. There was no restriction on articles based on language or publication status.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of study quality was undertaken by two reviewers independently. Trials with similar patients, comparisons, and outcomes were pooled. Where pooling was inappropriate, trials are discussed in a narrative review.

PREVENTION

29 RCTs of support surfaces for pressure sore prevention were identified. Some high specification foam mattresses were more effective than 'standard' hospital foam mattresses in moderate-high risk patients. Pressure relieving mattresses in the operating theatre reduced the incidence of pressure sores post-operatively. The relative merits of alternating and constant low pressure, and of the different alternating pressure devices are unclear. Seat cushions and simple, constant low-pressure devices have not been adequately evaluated. Limited evidence suggests that low air loss beds reduce the incidence of pressure sores in intensive care.

TREATMENT

6 RCTs of support surfaces for pressure sore treatment were identified. There is good evidence that air-fluidised and low air loss beds improve healing rates. Seat cushions have not been adequately evaluated. 2 RCTs evaluated surfaces for both prevention and treatment in the same trial.

REVIEWER'S CONCLUSIONS

PREVENTION - There is good evidence of the effectiveness of high specification foam over standard hospital foam, and pressure relief in the operating theatre. Treatment - There is good evidence of the effectiveness of air-fluidised and low air loss devices as treatments. Overall, however, it is impossible to determine the most effective surface for either prevention or treatment.

Rapid identification of saponins in plant extracts by electrospray ionization multi-stage tandem mass spectrometry and liquid chromatography/tandem mass spectrometry

Electrospray ionization multi-stage tandem mass spectrometry (ESI-MS(n)) and liquid chromatography coupled with on-line mass spectrometry (LC/MS/MS) were applied to characterize saponins in crude extracts from Panax ginseng. The MS(n) data of the [M - H](-) ions of saponins can provide structural information on the sugar sequences of the saccharide chains and on the sapogins of saponins. By ESI-MS(n), non-isomeric saponins and isomeric saponins with different aglycones can be determined rapidly in plant extracts. LC/MS/MS is a good complementary analytical tool for determination of isomeric saponins. These approaches constitute powerful analytical tools for rapid screening and structural assignment of saponins in plant extracts.

Risperidone versus typical antipsychotic medication for schizophrenia

BACKGROUND

The 'conventional' neuroleptic drugs, such as haloperidol and chlorpromazine, are frequently used as the first line treatment for people with schizophrenia. However, about 5-25% of these people show poor response to these treatments and side effects often makes compliance with the 'older generation' of drug treatment problematic. Although the efficacy of these medications with respect to 'positive' symptoms is well described, little evidence exists that 'conventional' antipsychotic treatment has any effect on the 'negative' symptoms of schizophrenia. Risperidone is one of the 'new generation' neuroleptic compounds. As well as its reputed tendency to cause fewer movement disorders it is claimed that risperidone may improve negative symptoms.

OBJECTIVES

To evaluate the effectiveness of risperidone for schizophrenia in comparison to 'conventional' neuroleptic drugs.

SEARCH STRATEGY

Electronic searches of Biological Abstracts (1980-1997), Cochrane Schizophrenia Group's Register (1997), The Cochrane Library (1997, Issue1), EMBASE (1980-1997), MEDLINE (1966-1997), PsycLIT (1974-1997), and SCISEARCH (1997) were undertaken. References of all identified studies were searched for further trial citations. Pharmaceutical companies and authors of trials were contacted.

SELECTION CRITERIA

All randomised trials comparing risperidone to any 'conventional' neuroleptic treatment for those with schizophrenia or other serious mental illnesses.

DATA COLLECTION AND ANALYSIS

Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were also independently extracted. Sensitivity analyses on dose of risperidone, haloperidol and duration of illness were undertaken for the primary outcomes of clinical improvement, side effects (movement disorders) and acceptability of treatment. For homogeneous dichotomous data the odds ratio (OR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis.

MAIN RESULTS

Twelve short-term studies and two long term studies provided data on 3401 people. This review provides no evidence relating to the effect of risperidone on cognitive or social functioning, quality of life, employment status, discharge from hospital and relapse rates. Risperidone increases the odds of moderate clinical improvement (OR 0.65, CI 0.55-0.77, NNT 10, CI 7-16). It appears to have little or no additional effect on the positive and negative symptoms of schizophrenia but did have less tendency to cause movement disorders, largely in comparison with haloperidol (OR 0.43, CI 0.34-0.55, NNT 7, CI 5-10) for use of antiparkinsonian medication. Risperidone seems to be more acceptable to those with schizophrenia (OR 0.69 CI 0.57-0.83, NNT 15, CI 10-30, 30% baseline risk of dropping out). Those taking risperidone are also marginally less likely to experience somnolence (OR 0.78, CI 0. 61-0.99, NNT 22). Weight gain, however, is more likely with risperidone (OR 1.51 CI 1.14-2.00, NNT 13). Funnel plots show that smaller studies generally show greater benefit for risperidone than larger studies. A publication bias in favour of risperidone amongst the included studies may explain this effect. Sensitivity analyses on dose of risperidone (excluding those receiving 1 or 2 mg) did not materially change the results for the principal outcomes. Excluding data from those on higher doses of haloperidol (>10mg/day) does marginally change the results. Risperidone is less effective in achieving clinical improvement and preventing dropout but outcomes relating to movement disorders change little.

REVIEWER'S CONCLUSIONS

Little can be concluded about the long term effects of risperidone and generalising results beyond a comparison with haloperidol would be imprudent. Risperidone may be more acceptable to those with schizophrenia and have marginal benefits in terms of limited clinical improvement and side

[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.

[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.

Exploring heterogeneity in meta-analysis: is the L'Abbé plot useful?

By using a published meta-analysis as an example, this paper discusses the use of L'Abbe plot for investigating the potential sources of heterogeneity in meta-analysis. As compared with other graphic procedures, the L'Abbe plot is useful to identify not only the studies having different results from other studies, but also the study arms that are responsible for such differences. This may be important for determining the focus of heterogeneity investigations. Results of stochastic simulation indicate that, purely because of random variation, studies with event rates of around 50% are more likely to be identified as outliers in a L'Abbe plot. This paper also demonstrates that different methods may identify different trials as "outliers" in meta-analysis.

Application of capillary nongel sieving electrophoresis for gene analysis

Capillary electrophoresis (CE) has proved to be a strong tool for DNA analysis and has found abundant applications in the fields of restriction fragment sizing, mutation screening, polymerase chain reaction (PCR) product characterizing and forensic identifying. CE may be the main alternative to slab gel electrophoresis. Capillary nongel electrophoresis is the most favorable mode when aiming for this purpose because of its advantages of long lifetime, easy operation, good reproducibility, and low expense. In this paper, a new kind of sieving matrix, with mannitol as the additive for capillary electrophoresis, as well as related methods and their application for gene analysis were reported. Nine DNA fragments amplified by multiplex PCR from a normal dystrophin gene were well separated by this system. Three different deletions were found in Duchenne muscular dystrophy (DMD) patients. Three to four copies of the sex-determination region of the Y chromosome (SRY) gene, as well as the phenylalanine hydroxylase (PAH) gene, could be detected in mixed samples. The frequencies of short tandem repeats (STR) in PAH genes was analyzed in 61 normal Chinese individuals and 6 phenylketonuria families. One case of prenatal gene diagnosis was performed. By using this matrix, CE coupled with reverse transcription PCR (RT-PCR), the analysis of the alternative splicing expression pattern of the fragile X mental retardation 1 (FMR1) gene in adult lung tissue was achieved.

The role of electronic journals in reducing publication bias

Publication bias poses a threat to the validity of medical research. It is unlikely that conventional paper journals can solve the problem of selective publication of studies with striking results because of their space limitation and need to be newsworthy. Peer-reviewed electronic journals without limitation of space might provide a solution to this paradox. To maintain the integrity of medical publication, editorial policy needs to be changed to accept clinical trials for publication, based only on the methodological criteria and not on the impact of their findings.

Simultaneous determination of lipo-alkaloids extracted from Aconitum carmiechaeli using electrospray ionization mass spectrometry and multiple tandem mass spectrometry

Electrospray ionization mass spectrometry (ESI-MS) combined with multiple tandem mass spectrometry (MS (n)) has been applied for simultaneously determining lipo-alkaloids from the aconite tubers. ESI-MS can give a very good mass separation for lipo-alkaloid mixture and MS (n) can provide structural information. Accordingly, structures were assigned to 12 known lipo-alkaloids including lipoaconitines, lipomesaconitines, lipodeoxyaconitines, and lipohypaconitines on the base of the information obtained using MS ( n). Also, four new lipo-alkaloids were found and their structures were interpreted using the MS (n) data.

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.

Expression of the neutrophil chemokine KC in the colon of mice with enterocolitis and by intestinal epithelial cell lines: effects of flora and proinflammatory cytokines

IL-10 plays an important role in preventing excessive inflammation to the normal flora in the intestinal lumen. The purpose of this study was to compare the effect of normal flora on inflammation in mice in which the IL-10 gene was disrupted. IL-10 knock-out mice housed in germfree conditions remained healthy while those housed in conventional conditions developed colitis after weaning, suggesting that IL-10 inhibits the adverse responses to luminal Ag. Crypt abscesses were present in virtually all of the diseased animals as evidenced by flattening of the epithelial cells and a large number of neutrophils in the lumen of the crypt. Since KC is a chemokine that is capable of recruiting neutrophils in mice, mRNA and protein for KC was measured. Increased levels of both KC mRNA and protein were detected in the colon of diseased mice. To determine whether the epithelial cells were capable of synthesizing KC and contributing to neutrophil accumulation in the crypts, a murine intestinal epithelial cell line (Mode-K) was shown to express mRNA and protein for KC. Two cytokines induced in association with colitis in these mice, TNF-alpha and IFN-gamma, increased the expression of KC mRNA and protein in murine epithelial cells. However, IL-10 was incapable of decreasing the induction of KC, even though the cells expressed the IL-10 receptor. These results suggest that the neutrophil chemokine KC is produced by gastrointestinal epithelial cells in response to inflammatory mediators that are expressed following exposure to normal flora in animals lacking IL-10.

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.

Application of Electrospray Ionization Mass Spectrometry Combined with Sequential Tandem Mass Spectrometry Techniques for the Profiling of Steroidal Saponin Mixture Extracted from Tribulus terrestris

Using electrospray ionization mass spectrometry combined with sequential tandem mass spectrometry (ESI-MS (n)), the steroidal saponin mixture extracted from TRIBULUS TERRESTRIS was studied. The structures of five known steroidal saponins and two unknown steroidal saponins in the saponin mixture were investigated by sequential tandem mass spectrometry experiments. All of the steroidal saponins displayed similar fragmentation behavior in ESI-MS (n), and the characteristic cross ring cleavage pattern could be used as a fingerprint for the identification of steroidal saponins. The methodology has been established as a powerful tool for the profiling of mixtures, especially of crude plant extracts, and the structural elucidation of compounds.

Quantitative analysis of pethidine using liquid secondary ion and tandem mass spectrometry

A method for the quantatitive determination of pethidine in human urine by liquid secondary ion and tandem mass spectrometry is presented. Quantification was carried out by using ketamine as internal standard. It was found that the collision-induced dissociation (CID) spectrum of the [M + H]+ ion of pethidine exhibited a prominent daughter ion at m/z 220 and ketamine also yielded the same daughter ion at m/z 220. For ((quadrupole)) quantitative analysis, the first quadrupole mass filter was set to transmit m/z 220 and a narrow-range magnet scan yielded a spectrum of parents, including m/z 238 and 248, correspending to ketamine and pethidine, respectively.

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.

Antimicrobial prophylaxis in colorectal surgery

This article summarises the findings of a systematic review of the literature concerning antimicrobial prophylaxis before colorectal surgery. From analysing 152 clinical trials certain conclusions can be drawn, such as the importance of ensuring that prophylactic therapy is active against both aerobic and anaerobic bacteria; and, single dose treatment can be as effective as a full course of antibiotics.

[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.

[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.

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.

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.

[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.

[Indirect sensitized upconversion in Tm3+ and Yb3+ codoped non-crystal pentaphosphate]

We report the blue upconversion luminescence of Tm3+ and Yb3+ codoped non-crystal pentaphosphate pumped by -798nm laser diode. The samples were directly excited to 3F4 level of Tm3+ ion. Two energy transfer processes between Tm3+ and Yb3+ contribute mainly to the population of 1G4 level of Tm3+. Phonon plays an important role in the upconversion process.

[Three-dimensional volumetric display--a new application of frequency up-conversion]

This paper discusses the present research situation and the application prospect of 3-D volumetric display technology. The possible usability and science significance of frequency up-conversion in 3-D volumetric display field are also demonstrated systematically. In ZBLAN: Pr, Yb glasses, we primarily demonstrated and achieved a new application of frequency up-conversion three dimensional volumetric display, using the two-frequency up-conversion of the rare earth ions. The efficiency of luminescence of Pr was enhanced much by the energy transfer between Pr and Yb ions.

[XPS and MS study of phosphorous heterocycle compounds]

7 new phosphorous heterocycle compounds have been studied by XPS and MS. From XPS and MS data we have discussed the existence form and manner of the compounds isomer, and verified that the isomer only exists in gaseous state and liquid state.

[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.