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Biomedical subjects

R Crowther

Publications and source records attributed to R Crowther.

At least 19 recordsLinked to original sources

Day hospital versus admission for acute psychiatric disorders.

BACKGROUND: Inpatient treatment is an expensive way of caring for people with acute psychiatric disorders. It has been proposed that many of those currently treated as inpatients could be cared for in acute psychiatric day hospitals. OBJECTIVES: To assess the effects of day hospital versus inpatient care for people with acute psychiatric disorders. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (Cochrane Library, issue 4, 2000), MEDLINE (January 1966 to December 2000), EMBASE (1980 to December 2000), CINAHL (1982 to December 2000), PsycLIT (1966 to December 2000), and the reference lists of articles. We approached trialists to identify unpublished studies. SELECTION CRITERIA: Randomised controlled trials of day hospital versus inpatient care, for people with acute psychiatric disorders. Studies were ineligible if a majority of participants were under 18 or over 65, or had a primary diagnosis of substance abuse or organic brain disorder. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers and cross-checked. Relative risks and 95% confidence intervals (CI) were calculated for dichotomous data. Weighted or standardised means were calculated for continuous data. Day hospital trials tend to present similar outcomes in slightly different formats, making it difficult to synthesise data. Individual patient data were therefore sought so that outcomes could be reanalysed in a common format. MAIN RESULTS: Nine trials (involving 1568 people) met the inclusion criteria. Individual patient data were obtained for four trials (involving 594 people). Combined data suggested that, at the most pessimistic estimate, day hospital treatment was feasible for 23% (n=2268, CI 21 to 25) of those currently admitted to inpatient care. Individual patient data from three trials showed no difference in number of days in hospital between day hospital patients and controls (n=465, 3 RCTs, WMD -0.38 days/month CI -1.32 to 0.55). However, compared to controls, people randomised to day hospital care spent significantly more days in day hospital care (n=265, 3 RCTs, WMD 2.34 days/month CI 1.97 to 2.70) and significantly fewer days in inpatient care (n=265, 3 RCTs, WMD -2.75 days/month CI -3.63 to -1.87). There was no significant difference in readmission rates between day hospital patients and controls (n=667, 5 RCTs, RR 0.91 CI 0.72 to 1.15). For patients judged suitable for day hospital care, individual patient data from three trials showed a significant time-treatment interaction, indicating a more rapid improvement in mental state (n=407, Chi-squared 9.66, p=0.002), but not social functioning (n=295, Chi-squared 0.006, p=0.941) amongst patients treated in the day hospital. Four of five trials found that day hospital care was cheaper than inpatient care (with cost reductions ranging from 20.9 to 36.9%). REVIEWER'S CONCLUSIONS: Caring for people in acute day hospitals can achieve substantial reductions in the numbers of people needing inpatient care, whilst improving patient outcome.

Acute Disease↗

Vocational rehabilitation for people with severe mental illness.

BACKGROUND: Unemployment rates are high amongst people with severe mental illness, yet surveys show that most want to work. Vocational rehabilitation services exist to help mentally ill people find work. Traditionally, these services have offered a period of preparation (Pre-vocational Training), before trying to place clients in competitive (i.e. open) employment. More recently, some services have begun placing clients in competitive employment immediately whilst providing on-the-job support (Supported Employment). It is unclear which approach is most effective. OBJECTIVES: To assess the effects of Pre-vocational Training and Supported Employment (for people with severe mental illness) against each other and against standard care (in hospital or community). In addition, to assess the effects of: (a) special varieties of Pre-vocational Training (Clubhouse model) and Supported Employment (Individual Placement and Support model); and (b) techniques for enhancing either approach, for example payment or psychological intervention. SEARCH STRATEGY: Searches were undertaken of CINAHL (1982-1998), The Cochrane Library (Issue 2, 1999), EMBASE (1980-1998), MEDLINE (1966-1998) and PsycLIT (1887-1998). Reference lists of eligible studies and reviews were inspected and researchers in the field were approached to identify unpublished studies. SELECTION CRITERIA: Randomised controlled trials of approaches to vocational rehabilitation for people with severe mental illness. DATA COLLECTION AND ANALYSIS: Included trials were reliably selected by a team of two raters. Data were extracted separately by two reviewers and cross-checked. Authors of trials were contacted for additional information. Relative risks (RR) and 95% confidence intervals (CI) of homogeneous dichotomous data were calculated. A random effects model was used for heterogeneous dichotomous data. Continuous data were presented in tables (there were insufficient continuous data for formal meta-analysis). A sensitivity analysis was performed, excluding poorer quality trials. MAIN RESULTS: Eighteen randomised controlled trials of reasonable quality were identified. The main finding was that on the primary outcome (number in competitive employment) Supported Employment was significantly more effective than Pre-vocational Training; for example, at 18 months 34% of people in Supported Employment were employed versus 12% in Pre-vocational Training (RR random effects (unemployment) 0.76 95% CI 0.64 to 0.89, NNT 4.5). Clients in Supported Employment also earned more and worked more hours per month than those in Pre-vocational Training. There was no evidence that Pre-vocational Training was more effective in helping clients to obtain competitive employment than standard community care. REVIEWER'S CONCLUSIONS: Supported employment is more effective than Pre-vocational Training in helping severely mentally ill people to obtain competitive employment. There is no clear evidence that Pre-vocational Training is effective.

Employment↗

Day hospital versus out-patient care for psychiatric disorders.

BACKGROUND: This review considers the use of day hospitals as an alternative to out-patient care. Three types of day hospital are covered by the review: 'day treatment programmes', 'day care centres' and 'transitional' day hospitals. Day treatment programmes offer more intense treatment for patients who have failed to respond to out-patient care (usually patients with affective or personality disorders). Day care centres offer structured support to patients with long-term severe mental disorders (mainly schizophrenia), who would otherwise be treated in the out-patient clinic. Transitional day hospitals offer time-limited care to patients who have just been discharged from in-patient care. OBJECTIVES: The review had three objectives. First, to assess the effectiveness of day treatment programmes versus out-patient care for people with treatment-refractory disorders. Second, to assess the effectiveness of day care centres versus out-patient care for people with severe long term disorders. Third, to assess the effectiveness of transitional day hospital care for people who had just been discharged from hospital. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (Cochrane Library, issue 4, 2000), MEDLINE (January 1966 to December 2000), EMBASE (1980 to December 2000), CINAHL (1982 to December 2000), Psyc LIT (1966 to December 2000), and the reference lists of articles. Researchers were approached to identify unpublished studies. SELECTION CRITERIA: Randomised controlled trials comparing day hospital care (including day treatment programme, day care centre, and transitional day hospital) against out-patient care. Studies were ineligible if a majority of participants were under 18 or over 65, or who had a primary diagnosis of substance abuse or organic brain disorder. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers and cross-checked. Relative risks and 95% confidence intervals (CI) were calculated for dichotomous data. Weighted or standardised means were calculated for continuous data. MAIN RESULTS: There was evidence from one trial suggesting that day treatment programmes were superior to continuing out-patient care in terms of improving psychiatric symptoms. There was no evidence that day treatment programmes were better or worse than out-patient care on any other clinical or social outcome variable, or on costs. There was no evidence that day care centres were better or worse than out-patient care on any clinical or social outcome variable. There were some inconclusive data on costs suggesting that day care centres might be more expensive than out-patient care. There was evidence from one trial suggesting that transitional day hospital care was superior to out-patient care in keeping patients engaged in treatment, however there was insufficient evidence to judge whether it was better or worse on any other clinical or social outcome variable, or on costs. REVIEWER'S CONCLUSIONS: There is only limited evidence to justify the provision of day treatment programmes and transitional day hospital care, and no evidence to support the provision of day care centres.

Aftercare↗

X-ray structure of a novel matrix metalloproteinase inhibitor complexed to stromelysin.

A new class of matrix metalloproteinase (MMP) inhibitors has been identified by screening a collection of compounds against stromelysin. The inhibitors, 2,4,6-pyrimidine triones, have proven to be potent inhibitors of gelatinases A and B. An X-ray crystal structure of one representative compound bound to the catalytic domain of stromelysin shows that the compounds bind at the active site and ligand the active-site zinc. The pyrimidine triones mimic substrates in forming hydrogen bonds to key residues in the active site, and provide opportunities for placing appropriately chosen groups into the S1' specificity pocket of MMPS: A number of compounds have been synthesized and assayed against stromelysin, and the variations in potency are explained in terms of the binding mode revealed in the X-ray crystal structure.

Binding Sites↗

Systematic reviews of the effectiveness of day care for people with severe mental disorders: (1) acute day hospital versus admission; (2) vocational rehabilitation; (3) day hospital versus outpatient care.

UNLABELLED: ***ACUTE DAY HOSPITAL VERSUS ADMISSION FOR ACUTE PSYCHIATRIC DISORDERS*** BACKGROUND: Inpatient treatment is an expensive way of caring for people with acute psychiatric disorders. It has been proposed that many of those currently treated as inpatients could be cared for in acute psychiatric day hospitals. OBJECTIVE: The aim of this review was to assess the effectiveness and feasibility of day hospital versus inpatient care for people with acute psychiatric disorders. METHODS - STUDY SELECTION: Eligible studies were randomised controlled trials of day hospital versus inpatient care for people with acute psychiatric disorders. Studies were excluded if they were primarily concerned with elderly people, children, or patients with a diagnosis of organic brain disease or substance abuse. METHODS - DATA SOURCES: We searched the Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, PsycLIT, and the reference lists of articles. Researchers were approached to identify unpublished studies. Trialists were asked to provide individual patient data. METHODS - DATA EXTRACTION: Data were extracted independently by two reviewers and cross-checked. METHODS - DATA SYNTHESIS: Relative risk (RR) and 95% confidence intervals (CIs) were calculated for dichotomous data. Weighted or standardised means were calculated for continuous data. Day hospital trials tend to present similar outcomes in slightly different formats, making it difficult to synthesise the data. Individual patient data were therefore sought so that outcomes could be re-analysed using a common format. RESULTS: Nine trials met the inclusion criteria (involving 1568 randomised patients and 2268 assessed for suitability of day hospital treatment). Individual patient data were obtained for four trials (involving 594 people). A sensitivity analysis of combined data suggested that day hospital treatment was feasible for at worst 23.2% (n = 2268; 95% CI, 21.2 to 25.2) and at best 37.5% (n = 1768; 95% CI, 35.2 to 39.8) of those currently admitted to inpatient care. Individual patient data from three trials showed no difference in the number of days in hospital (combining day hospital days and inpatient days) between day hospital patients and controls (n = 465; weighted mean difference (WMD) = -0.38 days/ month; 95% CI, -1.32 to 0.55). However, compared with controls, patients randomised to day hospital care spent significantly more days in day hospital care (n = 265; WMD = 2.34 days/month; 95% CI, 1.97 to 2.70) and significantly fewer days in inpatient care (n = 265; WMD = -2.75 days/month; 95% CI, -3.63 to -1.87). There was no difference between readmission rates for day hospital and control patients (n = 667; RR = 0.91; 95% CI, 0.72 to 1.15). Individual patient data from three trials showed a significant time-treatment interaction, indicating a more rapid improvement in mental state (n = 407; c2 = 9.66; p = 0.002), but not social functioning (n = 295; c2 = 0.006; p = 0.941) amongst day hospital patients. Four of five trials demonstrated that day hospital care was cheaper than inpatient care (with overall cost reductions ranging from 20.9% to 36.9%). CONCLUSIONS: Acute day hospitals are an attractive option in situations where demand for inpatient care is high and facilities exist that are suitable for conversion. They are a less attractive option when demand for inpatient care is low and where effective alternatives already exist. The interpretation of day hospital research would be enhanced if future trials made use of the common set of outcome measures used in this review. It is important to examine how acute day hospital care can be most effectively integrated into a modern community-based psychiatric service. ***VOCATIONAL REHABILITATION FOR PEOPLE WITH SEVERE MENTAL DISORDERS*** BACKGROUND: People who are disabled by severe mental disorders experience high rates of unemployment, but most want to work. Prevocational training (PVT) is the traditional approach to helping such people to return to work. PVT assumes that a period of preparation is required before those with a severe mental disorder can enter into competitive employment. Supported Employment (SEm) is a new approach that places clients in competitive employment without extended preparation. Both PVT and SEm are widely practised, but it is unclear which is the most effective. OBJECTIVES: The overall objective of this review was to assess the effectiveness of PVT and SEm relative to each other and to standard care (in hospital or the community) for people with severe mental disorders. In addition, the review examined the effectiveness of: (1) special types of PVT ("clubhouse" model) and SEm (individual placement and support model); and (2) modifications for enhancing PVT (e.g. payment or psychological interventions). METHODS - STUDY SELECTION: Eligible studies were randomised controlled trials (RCTs) examining the effectiveness of vocational rehabilitation approaches (PVT and SEm or modifications) for people of working age and suffering from a severe mental disorder. METHODS - DATA SOURCES: Relevant trials were identified from searches of the Cochrane Schizophrenia Group's specialised register, MEDLINE, EMBASE, CINAHL and PsycLIT, and the reference lists of all identified studies and review articles. Researchers who were active in the field were approached in order to identify unpublished studies. METHODS - DATA EXTRACTION: All data were extracted independently by two reviewers and cross-checked. Continuous data were excluded if they were collected by using an unpublished scale or were based on a subset of items from a scale. METHODS - DATA SYNTHESIS: For all comparisons, the primary outcome was the number of clients who were in competitive employment at various time points. Secondary outcomes were: other employment outcomes, clinical outcome and costs. The relative risk (RR) and number-needed-to-treat (NNT) were calculated for the relevant categorical outcomes. Continuous data were either presented as in the original trial reports or, where possible, combined across trials as a standardised mean difference score. RESULTS: Eighteen RCTs of reasonable quality were identified: PVT versus hospital controls, three RCTs, n = 172; PVT versus community controls, five RCTs, n = 1204; modified PVT, four RCTs, n = 423; SEm versus community controls, one RCT, n = 256; and SEm versus PVT, five RCTs, n = 491). The main finding was that, on the primary outcome (number in competitive employment), SEm was significantly more effective than PVT at all time points (e.g. at 12 months, SEm 34% employed, PVT 12% employed; RR of not being in competitive employment = 0.76, 95% confidence interval 0.69 to 0.84, NNT = 4.5). Clients in SEm also earned more and worked more hours per month than those in PVT. CONCLUSIONS: The main finding was that SEm was more effective than PVT for patients suffering from a severe mental disorder who wanted to work. There was no evidence that PVT was more effective than standard community care or hospital care. The implication of these findings is that people suffering from mental disorders who want to work should be offered the option of SEm. Commissioning agencies would be justified in encouraging vocational rehabilitation (VR) providers to develop more SEm schemes. From a research perspective, the cost-effectiveness of SEm should be examined in larger multicentre trials, both within and outside the USA. There is a case for countries outside the USA to survey their existing VR services to determine the extent to which the most effective interventions are being offered. ***DAY HOSPITAL VERSUS OUTPATIENT CARE FOR PATIENTS WITH PSYCHIATRIC DISORDERS*** BACKGROUND: This review considers the use of day hospitals as an alternative to outpatient care. Two typesof day hospital provision are covered: "day treatment programmes" and "day care centres". Day treatment programmes are day hospitals that are used to enhance the treatment of patients with anxiety or depressive disorders who have failed to respond to outpatient care. Day care centres are day hospitals that offer structured support to patients with long-term severe mental disorders who would otherwise be treated in an outpatient clinic. OBJECTIVES: There were two objectives: first, to assess the effectiveness of day treatment programmes versus outpatient care for people with non-psychotic disorders; and, secondly, to assess the effectiveness of day care centres versus outpatient care for people with severe long-term disorders. METHODS - STUDY SELECTION: Eligible studies were randomised controlled trials comparing day hospital care (either a day treatment programme or a day care centre) with outpatient care. Studies were ineligible if they were largely restricted to patients who were aged under 18 or over 65 years or who had a primary diagnosis of substance abuse or organic brain disorder. METHODS - DATA SOURCES: Relevant trials were identified from searches of the Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, PsycLIT, and the reference lists of all identified studies and review articles. Researchers were approached to identify unpublished studies. Trialists were asked to provide individual patient data. METHODS - DATA EXTRACTION: All data were extracted independently by two reviewers and cross-checked. METHODS - DATA SYNTHESIS: Relative risks and 95% confidence intervals were calculated for dichotomous data. Standardised mean differences were calculated for continuous data. RESULTS: There was evidence from two of the five trials identified suggesting that day treatment programmes were superior to continuing outpatient care in terms of improving psychiatric symptoms. There was no evidence to suggest that day treatment programmes were better or worse than outpatient care on any other clinical or social outcome variable or on costs. (ABSTRACT TRUNCATED)

Adult↗

A program designed to monitor the course and management of depressive illness across the primary/secondary interface.

Information Technology (IT) is an increasingly important area for all aspects of life in the twenty first century. Computers have an impact on both our home life and our work life with information on many aspects of our lives being held on computer systems, some of which we are unaware. Despite this universal progression towards IT, certain areas within the National Health Service are still considered to be somewhat old fashioned in their tendency to resolutely adhere to recording information on paper. One of these areas is that of the mental health services, which perhaps given the nature of having a number of care sites makes it well suited to having the use of a well designed computer system capable of collating and co-ordinating all aspects of patient's management. This paper describes the development and implementation of a computer system designed to hold information on patients with depressive disorder across all mental health sites within both primary and secondary care. Data were manually input from patients' case notes onto a specially designed system at all sites and were then merged onto a master database by use of a patient's NHS number. Ultimately the master database held data on the entire course and management of 914 patients who suffered from depressive disorder that came within the two general practice catchment area. Professional perceptions of the usefulness of the database are discussed along with suggestions for promoting the implementation of such a system within mental health services nationwide.

Depressive Disorder↗

Peptide and peptide mimetic inhibitors of antigen presentation by HLA-DR class II MHC molecules. Design, structure-activity relationships, and X-ray crystal structures.

Molecular features of ligand binding to MHC class II HLA-DR molecules have been elucidated through a combination of peptide structure-activity studies and structure-based drug design, resulting in analogues with nanomolar affinity in binding assays. Stabilization of lead compounds against cathepsin B cleavage by N-methylation of noncritical backbone NH groups or by dipeptide mimetic substitutions has generated analogues that compete effectively against protein antigens in cellular assays, resulting in inhibition of T-cell proliferation. Crystal structures of four ternary complexes of different peptide mimetics with the rheumatoid arthritis-linked MHC DRB10401 and the bacterial superantigen SEB have been obtained. Peptide-sugar hybrids have also been identified using a structure-based design approach in which the sugar residue replaces a dipeptide. These studies illustrate the complementary roles played by phage display library methods, peptide analogue SAR, peptide mimetics substitutions, and structure-based drug design in the discovery of inhibitors of antigen presentation by MHC class II HLA-DR molecules.

Antigen Presentation↗

Pharmacokinetic profile of a low-molecular weight heparin (reviparin) in pregnant patients. A prospective cohort study.

Anticoagulant therapy during pregnancy is problematic. Patients are frequently treated with long-term low-molecular weight heparin despite a lack of evidence for its effectiveness, and in the absence of validated dosing recommendations. The objectives of this investigation were to characterize the safety and pharmacokinetic behavior of a low-molecular weight heparin (reviparin) administered throughout pregnancy. Forty-two patients followed in a tertiary-care rheumatology clinic who received prophylactic doses of reviparin (4900 anti-Xa units subcutaneously once daily) were enrolled in this investigation. Anti-Xa heparin levels, weights, and gestational ages of the patients were obtained on up to four occasions distributed throughout their pregnancy. The achieved anti-Xa heparin levels were highly correlated with the patient's weight, irrespective of the gestational age. No toxicity other than injection site hematomas was observed. The achieved intensity of anticoagulation with reviparin varies during pregnancy in direct proportion to the patient's weight. This variability may mandate dose adjustment in response to changes in a patient's weight during pregnancy, particularly if low-molecular weight heparin is administered at therapeutic doses.

Abortion, Habitual↗

The diagnosis and management of insomnia in clinical practice: a practical evidence-based approach.

Insomnia, or the dissatisfaction with the quantity, quality or timing of sleep, is a common complaint. Because the definition of "normal" sleep is not well established, the estimates of the prevalence and severity of insomnia vary widely. Insomnia is often secondary to underlying psychiatric and medical conditions, and these should be evaluated and treated as a first measure. Nonpharmacological interventions for insomnia including sleep hygiene manoeuvres and exercise are recommended, although the success of these interventions has not been well documented. Benzodiazepines have been the pharmacologic agents of choice for the treatment of insomnia, but there is reason to exercise caution with their use; their overall benefit compared with placebo appears to be minor, and they are often associated with adverse cognitive effects. Unfortunately, no other class of drugs has proven to be superior to the benzodiazepines in terms of benefit:risk ratio. Given the importance of sleep for health and normal daily functioning the diagnosis, prognosis and treatment of insomnia should be a research priority.

Benzodiazepines↗

Meta-analysis of benzodiazepine use in the treatment of insomnia.

OBJECTIVE: To systematically review the benefits and risks associated with the use of benzodiazepines to treat insomnia in adults. DATA SOURCES: MEDLINE and the Cochrane Controlled Trials Registry were searched for English-language articles published from 1966 to December 1998 that described randomized controlled trials of benzodiazepines for the treatment of insomnia. Key words included "benzodiazepines" (exploded), "randomized controlled trial" and "insomnia." Bibliographies of relevant articles were reviewed for additional studies and manufacturers of benzodiazepines were asked to submit additional randomized controlled trial reports not in the literature. STUDY SELECTION: Articles were considered for the meta-analysis if they were randomized controlled trials involving patients with insomnia and compared a benzodiazepine with placebo or another active agent. Of the 89 trials originally identified, 45 met our criteria, representing a total of 2672 patients. DATA EXTRACTION: Data were extracted regarding the participants, the setting, details of the intervention, the outcomes (including adverse effects) and the methodologic quality of the studies. DATA SYNTHESIS: The meta-analyses of sleep records indicated that, when compared with placebo, benzodiazepines decreased sleep latency by 4.2 minutes (non-significant; 95% confidence interval (CI -0.7 to 9.2) and significantly increased total sleep duration by 61.8 minutes (95% CI 37.4 to 86.2). Patient-reported outcomes were more optimistic for sleep latency; those randomized to benzodiazepine treatment estimated a sleep latency decrease of 14.3 minutes (95% CI 10.6 to 18.0). Although more patients receiving benzodiazepine treatment reported adverse effects, especially daytime drowsiness and dizziness or light-headedness (common odds ratio 1.8, 95% CI 1.4 to 2.4), dropout rates for the benzodiazepine and placebo groups were similar. Cognitive function decline including memory impairment was reported in several of the studies. Zopiclone was not found to be superior to benzodiazepines on any of the outcome measures examined. INTERPRETATION: The use of benzodiazepines in the treatment of insomnia is associated with an increase in sleep duration, but this is countered by a number of adverse effects. Additional studies evaluating the efficacy of nonpharmacological interventions would be valuable.

Adult↗

Meta-analysis of benzodiazepine use in the treatment of acute alcohol withdrawal.

OBJECTIVE: To analyse the evidence for the efficacy and potential harmful effects of benzodiazepines compared with other therapies in the treatment of acute alcohol withdrawal. DATA SOURCES: MEDLINE and the Cochrane Controlled Trials Registry were searched for English-language articles published from 1966 to December 1997 that described randomized controlled trials (RCTs) of benzodiazepines in the treatment of acute alcohol withdrawal. Key words included "benzodiazepines" (exploded) and "randomized controlled trial." Bibliographies of relevant articles were reviewed for additional RCTs, and manufacturers of benzodiazepines were asked to submit additional RCT reports not in the literature. STUDY SELECTION: Articles were considered for the meta-analysis if they were RCTs involving patients experiencing acute alcohol withdrawal and comparing a benzodiazepine available in Canada with placebo or an active control drug. Of the original 23 trials identified, 11 met these criteria, representing a total of 1286 patients. DATA EXTRACTION: Data were extracted regarding the participants, the setting, details of the intervention, the outcomes (including adverse effects) and the methodologic quality of the studies. DATA SYNTHESIS: The meta-analysis of benefit (therapeutic success within 2 days) showed that benzodiazepines were superior to placebo (common odds ratio [OR] 3.28, 95% confidence interval [CI] 1.30-8.28). Data on comparisons between benzodiazepines and other drugs, including beta-blockers, carbamazepine and clonidine, could not be pooled, but none of the alternative drugs was found to be clearly more beneficial than the benzodiazepines. The meta-analysis of harm revealed no significant difference between benzodiazepines and alternative drugs in terms of adverse events (common OR 0.67, 95% CI 0.34-1.32) or dropout rates (common OR 0.68, 95% CI 0.47-0.97). INTERPRETATION: Benzodiazepines should remain the drugs of choice for the treatment of acute alcohol withdrawal.

Acute Disease↗

Diagnosis and management of acute alcohol withdrawal.

Alcohol abuse produces a considerable burden of illness in the Canadian population. The diagnosis of alcohol dependence and withdrawal can be difficult, particularly in the setting of covert intake or comorbidity. Two validated scales, the CAGE questionnaire to screen for alcohol abuse and dependence and the Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) scale to assess the severity of withdrawal, are valuable tools for clinicians to use on a regular basis. For the treatment of alcohol withdrawal, compelling anecdotal evidence supports the routine administration of thiamine, but not necessarily other vitamins. Phenytoin has not been shown to be superior to placebo for uncomplicated withdrawal seizures. Neuroleptics are not recommended for routine use. Sedation with benzodiazepines guided by the CIWA-Ar results is recommended. There is good evidence that the management of alcohol withdrawal can be improved with the routine use of the CIWA-Ar scale to assess severity, treatment with adequate doses of benzodiazepines and follow-up monitoring of patients in alcohol withdrawal.

Acute Disease↗

Protein farnesyltransferase: structure and implications for substrate binding.

The rat protein farnesyltransferase crystal structure has been solved by multiple isomorphous replacement methods at a resolution of 2.75 A. The three-dimensional structure, together with recent data on the effects of several mutations, led us to propose a model for substrate binding which differs from the model presented by Park et al. based on their independent structure determination [Park, H. -W., Boduluri, S. R., Moomaw, J. F., Casey, P. J., and Beese, L. S. (1997) Science 275, 1800-1804]. Both farnesyl diphosphate and peptide substrates can be accommodated in the hydrophobic active-site barrel, with the sole charged residue inside the barrel, Arg202 of the beta-subunit, forming a salt bridge with the negatively charged carboxy terminus of peptide substrates. Our proposals are based in part on the observation of electron density in the active site which can be modeled as bound farnesyl diphosphate carried through the enzyme purification. In addition, our model explains in structural terms the results of mutational studies which have identified several residues critical for substrate specificity and catalysis.

Alkyl and Aryl Transferases↗

Functional subtyping of neurokinin receptors on canine proximal colonic mucosa.

Functional subtyping of the receptors responsible for the neural and nonneural effects of substance P (SP) on the canine proximal colon were studied. Selective agonists and antagonists were used with two different in vitro preparations. The mucosa contained the muscularis mucosa and attendant submucosal plexuses, whereas the epithelium was devoid of both. We obtained the following results: [Sar9,Met(O2)11]SP (Sar9SP), a neurokinin-1 receptor agonist, stimulated both preparations; senktide, a neurokinin-3 agonist, evoked a response only on the mucosal preparation; [beta-Ala8]NKA4-10, a neurokinin-2 agonist, was ineffective on both preparations; tetrodotoxin completely inhibited the mucosal responses to senktide, but the inhibitory effects on Sar9SP were only partial; CP-96,345, a neurokinin-1-selective antagonist, inhibited both epithelial and mucosal responses to Sar9SP and R487 [Trp7,beta-Ala8]NKA4-10, a neurokinin-3 antagonist, inhibited mucosal responses to senktide. Thus, the neural effects involved both neurokinin-1 and neurokinin-3 receptors, whereas the nonneural effects were mediated by neurokinin-1 receptors alone. Neurokinin-2 receptors were functionally absent.

Animals↗

Cholera-induced mucin secretion from rat intestine: lack of effect of cAMP, cycloheximide, VIP, and colchicine.

Purified cholera enterotoxin (20-50 micrograms) and dialyzed cholera filtrate (50-125 mg) increased net glycoprotein synthetic and secretory rates in rat intestinal epithelium. Specific goblet cell mucin secretion was increased 5- to 10-fold. However, other agents that increase intestinal cAMP and accelerate glycoprotein synthesis did not enhance mucin secretion. This was true for dibutyryl cAMP (10(-3) and 10(-2) M) with or without theophylline (10(-3) M) and isoproterenol (10(-4) M) with or without dibutyryl cAMP (10(-3) M). Hyperosmotic mannitol (450 mosmol/l), which increases fluid secretion but does not affect cAMP, and vasoactive intestinal peptide (2 X 10(-7) M), which increases both fluid secretion and cAMP, both failed to increase mucin secretion, implying that fluid "washout" of mucin adherent to the mucosal surface is not responsible for cholera-induced mucin secretion. Cycloheximide, an inhibitor of cholera diarrhea in vivo (20 mg/kg) or in vitro (1 mM), effectively abolished [3H]leucine incorporation into protein but did not affect cholera-induced mucin secretion. Colchicine (10-50 mg/kg) given to block microtubule assembly was similarly without effect on mucin secretion. These findings suggest that there is a dissociation of electrolyte/fluid and mucin secretory processes and cast doubt on the widely accepted notion that all cholera effects are mediated via the well-known adenylate cyclase-cAMP mechanism.

Animals↗