Antibiotics for acute otitis media in children

BACKGROUND

Acute otitis media (AOM) is one of the most common diseases in childhood for which antibiotics are commonly prescribed; a systematic review reported a pooled prevalence of 85.6% in high-income countries. This is an update of a Cochrane Review first published in the Cochrane Library in 1997 and updated in 1999, 2005, 2009, 2013 and 2015.

OBJECTIVES

To assess the effects of antibiotics for children with AOM.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Current Contents, CINAHL, LILACS and two trial registers. The date of the search was 14 February 2023.

SELECTION CRITERIA

We included randomised controlled trials comparing 1) antimicrobial drugs with placebo, and 2) immediate antibiotic treatment with expectant observation (including delayed antibiotic prescribing) in children with AOM.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened trials for inclusion and extracted data using the standard methodological procedures recommended by Cochrane. Our primary outcomes were: 1) pain at various time points (24 hours, two to three days, four to seven days, 10 to 14 days), and 2) adverse effects likely to be related to the use of antibiotics. Secondary outcomes were: 1) abnormal tympanometry findings, 2) tympanic membrane perforation, 3) contralateral otitis (in unilateral cases), 4) AOM recurrences, 5) serious complications related to AOM and 6) long-term effects (including the number of parent-reported AOM symptom episodes, antibiotic prescriptions and health care utilisation as assessed at least one year after randomisation). We used the GRADE approach to rate the overall certainty of evidence for each outcome of interest.

MAIN RESULTS

Antibiotics versus placebo We included 13 trials (3401 children and 3938 AOM episodes) from high-income countries, which we assessed at generally low risk of bias. Antibiotics do not reduce pain at 24 hours (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.78 to 1.01; 5 trials, 1394 children; high-certainty evidence), or at four to seven days (RR 0.76, 95% CI 0.50 to 1.14; 7 trials, 1264 children), but result in almost a third fewer children having pain at two to three days (RR 0.71, 95% CI 0.58 to 0.88; number needed to treat for an additional beneficial outcome (NNTB) 20; 7 trials, 2320 children; high-certainty evidence), and likely result in two-thirds fewer having pain at 10 to 12 days (RR 0.33, 95% CI 0.17 to 0.66; NNTB 7; 1 trial, 278 children; moderate-certainty evidence). Antibiotics increase the risk of adverse events such as vomiting, diarrhoea or rash (RR 1.38, 95% CI 1.16 to 1.63; number needed to treat for an additional harmful outcome (NNTH) 14; 8 trials, 2107 children; high-certainty evidence). Antibiotics reduce the risk of children having abnormal tympanometry findings at two to four weeks (RR 0.83, 95% CI 0.72 to 0.96; NNTB 11; 7 trials, 2138 children), slightly reduce the risk of experiencing tympanic membrane perforations (RR 0.43, 95% CI 0.21 to 0.89; NNTB 33; 5 trials, 1075 children) and halve the risk of contralateral otitis episodes (RR 0.49, 95% CI 0.25 to 0.95; NNTB 11; 4 trials, 906 children). However, antibiotics do not reduce the risk of abnormal tympanometry findings at six to eight weeks (RR 0.89, 95% CI 0.70 to 1.13; 3 trials, 953 children) and at three months (RR 0.94, 95% CI 0.66 to 1.34; 3 trials, 809 children) or late AOM recurrences (RR 0.94, 95% CI 0.79 to 1.11; 6 trials, 2200 children). Severe complications were rare, and the evidence suggests that serious complications do not differ between children treated with either antibiotics or placebo. Immediate antibiotics versus expectant observation We included six trials (1556 children) from high-income countries. The evidence suggests that immediate antibiotics may result in a reduction of pain at two to three days (RR 0.53, 95% CI 0.35 to 0.79; NNTB 8; 1 trial, 396 children; low-certainty evidence), but probably do not reduce the risk of pain at three to seven days (RR 0.75, 95% CI 0.50 to 1.12; 4 trials, 959 children; moderate-certainty evidence), and may not reduce the risk of pain at 11 to 14 days (RR 0.91, 95% CI 0.75 to 1.10; 1 trial, 247 children; low-certainty evidence). Immediate antibiotics increase the risk of vomiting, diarrhoea or rash (RR 1.87, 95% CI 1.39 to 2.51; NNTH 10; 3 trials, 946 children; high-certainty evidence). Immediate antibiotics probably do not reduce the proportion of children with abnormal tympanometry findings at four weeks and evidence suggests that immediate antibiotics may not reduce the risk of tympanic membrane perforation and AOM recurrences. No serious complications occurred in either group.

AUTHORS' CONCLUSIONS

This review reveals that antibiotics probably have no effect on pain at 24 hours, a slight effect on pain in the days following and only a modest effect on the number of children with tympanic perforations, contralateral otitis episodes and abnormal tympanometry findings at two to four weeks compared with placebo in children with AOM. In high-income countries, most cases of AOM spontaneously remit without complications. The benefits of antibiotics must be weighed against the possible harms: for every 14 children treated with antibiotics, one child experienced an adverse event (such as vomiting, diarrhoea or rash) that would not have occurred if antibiotics were withheld. For most children with mild disease in high-income countries, an expectant observational approach seems justified. Therefore, clinical management should emphasise advice about adequate analgesia and the limited role for antibiotics.

Immunoglobulin treatment for hospitalised infants and young children with respiratory syncytial virus infection

BACKGROUND

Millions of children are hospitalised due to respiratory syncytial virus (RSV) infection every year. Treatment is supportive, and current therapies (e.g. inhaled bronchodilators, epinephrine, nebulised hypertonic saline, and corticosteroids) are ineffective or have limited effect. Respiratory syncytial virus immunoglobulin may be used prophylactically to prevent hospital admission from RSV-related illness. It may be considered for the treatment of established severe RSV infection or for treatment in an immunocompromised host, although it is not licensed for this purpose. It is unclear whether immunoglobulins improve outcomes when used as a treatment for established RSV infection in infants and young children admitted to hospital. This is an update of a review first published in 2019.

OBJECTIVES

To assess the effects of immunoglobulins for the treatment of RSV-proven lower respiratory tract infections (LRTIs) in children aged up to three years, admitted to hospital.

SEARCH METHODS

For this 2022 update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections Specialised Register, Ovid MEDLINE, Embase, CINAHL, and Web of Science (from inception to 2 December 2022) with no restrictions. We searched two trial registries for ongoing trials (to 2 December 2022) and checked the reference lists of reviews and included articles for additional studies.

SELECTION CRITERIA

Randomised controlled trials comparing immunoglobulins with placebo in hospitalised infants and children aged up to three years with laboratory-diagnosed RSV lower respiratory tract infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, and extracted data. We assessed evidence certainty using GRADE.

MAIN RESULTS

In total, we included eight trials involving 906 infants and children aged up to three years. We included one new trial in this update. The immunoglobulin preparations used in these trials included anti-RSV immunoglobulin and the monoclonal antibody preparations palivizumab and motavizumab. Five trials were conducted at single or multiple sites within a single high-income country (four in the USA, one in Qatar). Three trials included study sites in different countries. All three of these trials included study sites in one or more high-income countries (USA, Chile, New Zealand, Australia, Qatar), with two trials also including a study site in a middle-income country (Panama). Five of the eight trials were "supported" or "sponsored" by the trial drug manufacturers. The evidence is very uncertain about the effect of immunoglobulins on mortality (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.14 to 5.27; 4 studies, 309 participants). There were four deaths - two amongst 98 children receiving immunoglobulins, and two amongst 98 children receiving placebo. One additional death occurred in a fourth trial, however the study group of the child was not known and the data were not included in the analysis (very low-certainty evidence). The use of immunoglobulins in infants and children admitted to hospital with RSV proven LRTI probably results in little to no difference in the length of hospitalisation (mean difference (MD) -0.13 days, 95% CI -0.37 to 0.12; 6 studies, 737 participants; moderate-certainty evidence). Immunoglobulins may result in little to no difference in the number of children who experience one or more adverse events of any severity or seriousness compared to placebo (RR 1.18, 95% CI 0.78 to 1.78; 5 studies, 340 participants; low-certainty evidence) or the number of children who experience one or more adverse events judged by study investigators to be serious in nature, compared to placebo (RR 1.08, 95% CI 0.65 to 1.79; 4 studies, 238 participants; low-certainty evidence). Certainty of evidence for secondary outcomes was low. This evidence suggests that use of immunoglobulins results in little to no difference in the need for, or duration of, mechanical ventilation and the need for, or duration of, supplemental oxygen. The use of immunoglobulins does not reduce the need for admission to the intensive care unit (ICU) and when children are admitted to the ICU results in little to no difference in the duration of ICU stay.

AUTHORS' CONCLUSIONS

We are very uncertain about the effect of immunoglobulins on mortality. We are moderately certain that use of immunoglobulins in hospitalised infants and children may result in little to no difference in the length of hospitalisation. Immunoglobulins may result in little to no difference in adverse events, the need for or duration of mechanical ventilation, supplemental oxygen, or admission to the intensive care unit, though we are less certain about this evidence and the true effect of immunoglobulins on these outcomes may differ markedly from the estimated effect observed in this review. All trials were conducted in high-income countries, and data from populations in which the rate of death from RSV infection is higher are lacking.

Immunoglobulin treatment for hospitalised infants and young children with respiratory syncytial virus infection

BACKGROUND

Millions of children are hospitalised due to respiratory syncytial virus (RSV) infection every year. Treatment is supportive, and current therapies (e.g. inhaled bronchodilators, epinephrine, nebulised hypertonic saline, and corticosteroids) are ineffective or have limited effect. Respiratory syncytial virus immunoglobulin is sometimes used prophylactically to prevent hospital admission from RSV-related illness. It may be considered for the treatment of established severe RSV infection or for treatment in an immunocompromised host, although it is not licenced for this purpose. It is unclear whether immunoglobulins improve outcomes when used as a treatment for established RSV infection in infants and young children admitted to hospital.  OBJECTIVES: To assess the effects of immunoglobulins for the treatment of RSV-proven lower respiratory tract infections in children aged up to three years, admitted to hospital.  SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, Ovid MEDLINE, Embase, CINAHL, and Web of Science (from inception to 6 November 2018) with no restrictions. We searched two trial registries for ongoing trials (to 30 March 2018) and checked the reference lists of reviews and included articles for additional studies.

SELECTION CRITERIA

Randomised controlled trials comparing immunoglobulins with placebo in hospitalised infants and children aged up to three years with laboratory-diagnosed RSV lower respiratory tract infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, and extracted data. We assessed evidence quality using GRADE.

MAIN RESULTS

We included seven trials involving 486 infants and children aged up to three years. The immunoglobulin preparations used in these trials included anti-RSV immunoglobulin and the monoclonal antibody preparations palivizumab and motavizumab. We assessed the primary outcomes of mortality, length of hospital stay, and adverse events as providing low- or very low-certainty evidence due to risk of bias and imprecision. All trials were conducted at sites in high-income countries (USA, Chile, New Zealand, Australia), with two studies including a site in a middle-income country (Panama). Five of the seven studies were "supported" or "sponsored" by the trial drug manufacturers. We found no evidence of a difference between immunoglobulins and placebo for mortality (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.14 to 5.27; 3 trials; 196 children; 4 deaths; 2 deaths amongst 98 children receiving immunoglobulins, and 2 deaths amongst 98 children receiving placebo. One additional death occurred in a fourth trial, however, the study group of the child was not known and the data were not included in the analysis; very low-certainty evidence), and length of hospitalisation (mean difference -0.70, 95% CI -1.83 to 0.42; 5 trials; 324 children; low-certainty evidence). There was no evidence of a difference between immunoglobulins and placebo in adverse events of any severity or seriousness (reported in five trials) or serious adverse events (four trials) (RR for any severity 1.18, 95% CI 0.78 to 1.78; 340 children; low-certainty evidence, and for serious adverse events 1.08, 95% CI 0.65 to 1.79; 238 children; low-certainty evidence).We found no evidence of a significant difference between immunoglobulins and placebo for any of our secondary outcomes. We identified one ongoing trial.

AUTHORS' CONCLUSIONS

We found insufficient evidence of a difference between immunoglobulins and placebo for any review outcomes. We assessed the evidence for the effects of immunoglobulins when used as a treatment for RSV lower respiratory tract infection in hospitalised infants and young children as of low or very low certainty due to risk of bias and imprecision. We are uncertain of the effects of immunoglobulins on these outcomes, and the true effect may be substantially different from the effects reported in this review. All trials were conducted in high-income countries, and data from populations in which the rate of death from RSV infection is higher are lacking.

Systematic review of the effects of care provided with and without diagnostic clinical prediction rules

BACKGROUND

Diagnostic clinical prediction rules (CPRs) are worthwhile if they improve patient outcomes or provide benefits such as reduced resource use, without harming patients. We conducted a systematic review to assess the effects of diagnostic CPRs on patient and process of care outcomes.

METHODS

We searched electronic databases and a trial registry and performed citation and reference checks, for randomised trials comparing a diagnostic strategy with and without a CPR. Included studies were assessed for risk of bias and similar studies meta-analysed.

RESULTS

Twenty-seven studies evaluating diagnostic CPRs for 14 conditions were included. A clinical management decision was the primary outcome in the majority of studies. Most studies were judged to be at high or uncertain risk of bias on ≥3 of 6 domains. Details of study interventions and implementation were infrequently reported.For suspected Group A Streptococcus throat infection, diagnostic CPRs reduced symptoms (1 study) and antibiotic prescriptions (5 studies, RR 0.86, 95% CI 0.75 to 0.99). For suspected cardiac chest pain, diagnostic strategies incorporating a CPR improved early discharge rates (1 study), decreased objective cardiac testing (1 study) and decreased hospitalisations (1 study). For ankle injuries, Ottawa Ankle Rules reduced radiography when used with clinical examination (1 study) but had no effect on length of stay as a triage test (1 study). For suspected acute appendicitis, CPRs had no effect on rates of perforated appendix (1 study) or the number of non-therapeutic operations (5 studies, RR 0.68, 95% CI 0.43 to 1.08). For suspected pneumonia, CPRs reduced antibiotic prescribing without unfavourable outcomes (3 studies). For children with possible serious bacterial infection, diagnostic CPRs did not improve process of care outcomes (3 studies).

CONCLUSION

There are few randomised trials of diagnostic CPRs, and patient outcomes are infrequently reported. Diagnostic CPRs had a positive effect on process outcomes in some clinical conditions; however, many studies were at unclear or high risk of bias and the results may be context specific. Future studies should seek to detail how the CPR might alter the diagnostic pathway, report effects on both patient and process outcomes, and improve reporting of the study interventions and implementation.

TRIAL REGISTRATION

The protocol for this review was not registered with PROSPERO, the international prospective register of systematic review protocols. The review was conceived and protocol prepared prior to the launch of PROSPERO in February 2011.

Antibiotics for acute otitis media in children

BACKGROUND

Acute otitis media (AOM) is one of the most common diseases in early infancy and childhood. Antibiotic use for AOM varies from 56% in the Netherlands to 95% in the USA, Canada and Australia. This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 1997 and previously updated in 1999, 2005, 2009 and 2013.

OBJECTIVES

To assess the effects of antibiotics for children with AOM.

SEARCH METHODS

We searched CENTRAL (2015, Issue 3), MEDLINE (1966 to April week 3, 2015), OLDMEDLINE (1958 to 1965), EMBASE (January 1990 to April 2015), Current Contents (1966 to April 2015), CINAHL (2008 to April 2015) and LILACS (2008 to April 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing 1) antimicrobial drugs with placebo and 2) immediate antibiotic treatment with expectant observation (including delayed antibiotic prescribing) in children with AOM.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

For the review of antibiotics against placebo, 13 RCTs (3401 children and 3938 AOM episodes) from high-income countries were eligible and had generally low risk of bias. The combined results of the trials revealed that by 24 hours from the start of treatment, 60% of the children had recovered whether or not they had placebo or antibiotics. Pain was not reduced by antibiotics at 24 hours (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.78 to 1.01) but almost a third fewer had residual pain at two to three days (RR 0.70, 95% CI 0.57 to 0.86; number needed to treat for an additional beneficial outcome (NNTB) 20). A quarter fewer had pain at four to seven days (RR 0.76, 95% CI 0.63 to 0.91; NNTB 16) and two-thirds fewer had pain at 10 to 12 days (RR 0.33, 95% CI 0.17 to 0.66; NNTB 7) compared with placebo. Antibiotics did reduce the number of children with abnormal tympanometry findings at two to four weeks (RR 0.82, 95% CI 0.74 to 0.90; NNTB 11), at six to eight weeks (RR 0.88, 95% CI 0.78 to 1.00; NNTB 16) and the number of children with tympanic membrane perforations (RR 0.37, 95% CI 0.18 to 0.76; NNTB 33) and halved contralateral otitis episodes (RR 0.49, 95% CI 0.25 to 0.95; NNTB 11) compared with placebo. However, antibiotics neither reduced the number of children with abnormal tympanometry findings at three months (RR 0.97, 95% CI 0.76 to 1.24) nor the number of children with late AOM recurrences (RR 0.93, 95% CI 0.78 to 1.10) when compared with placebo. Severe complications were rare and did not differ between children treated with antibiotics and those treated with placebo. Adverse events (such as vomiting, diarrhoea or rash) occurred more often in children taking antibiotics (RR 1.38, 95% CI 1.19 to 1.59; number needed to treat for an additional harmful outcome (NNTH) 14). Funnel plots do not suggest publication bias. Individual patient data meta-analysis of a subset of included trials found antibiotics to be most beneficial in children aged less than two years with bilateral AOM, or with both AOM and otorrhoea.For the review of immediate antibiotics against expectant observation, five trials (1149 children) from high-income countries were eligible and had low to moderate risk of bias. Four trials (1007 children) reported outcome data that could be used for this review. From these trials, data from 959 children could be extracted for the meta-analysis of pain at three to seven days. No difference in pain was detectable at three to seven days (RR 0.75, 95% CI 0.50 to 1.12). One trial (247 children) reported data on pain at 11 to 14 days. Immediate antibiotics were not associated with a reduction in the number of children with pain (RR 0.91, 95% CI 0.75 to 1.10) compared with expectant observation. Additionally, no differences in the number of children with abnormal tympanometry findings at four weeks, tympanic membrane perforations and AOM recurrence were observed between groups. No serious complications occurred in either the antibiotic or the expectant observation group. Immediate antibiotics were associated with a substantial increased risk of vomiting, diarrhoea or rash compared with expectant observation (RR 1.71, 95% CI 1.24 to 2.36; NNTH 9).Results from an individual patient data meta-analysis including data from six high-quality trials (1643 children) that were also included as individual trials in our review showed that antibiotics seem to be most beneficial in children younger than two years of age with bilateral AOM (NNTB 4) and in children with both AOM and otorrhoea (NNTB 3).

AUTHORS' CONCLUSIONS

This review reveals that antibiotics have no early effect on pain, a slight effect on pain in the days following and only a modest effect on the number of children with tympanic perforations, contralateral otitis episodes and abnormal tympanometry findings at two to four weeks and at six to eight weeks compared with placebo in children with AOM. In high-income countries, most cases of AOM spontaneously remit without complications. The benefits of antibiotics must be weighed against the possible harms: for every 14 children treated with antibiotics one child experienced an adverse event (such as vomiting, diarrhoea or rash) that would not have occurred if antibiotics were withheld. Therefore clinical management should emphasise advice about adequate analgesia and the limited role for antibiotics. Antibiotics are most useful in children under two years of age with bilateral AOM, or with both AOM and otorrhoea. For most other children with mild disease in high-income countries, an expectant observational approach seems justified.

Supportive care needs in patients with lung cancer

INTRODUCTION

The goal of this study was to characterize the prevalence and intensity of supportive care needs and interest in specific supportive care services among individuals with lung cancer.

METHOD

Participants (n=109) were recruited from two medical centers in Southern California to complete questionnaires on physical and psychological functioning following diagnosis of lung cancer.

RESULTS

Participants reported the greatest need in the physical and daily living domain, followed by psychological needs, health system and informational needs, and patient care support needs. The most common unmet need was a lack of energy and tiredness (75%). Higher levels of supportive care needs were associated with worse physical functioning (beta=-0.30, p<0.001), greater symptom bother (beta=0.25, p=0.008), lower satisfaction with health care (beta=-0.24, p=0.002), and higher levels of intrusive thoughts about cancer (beta=0.40, p<0.001). The sample was most interested in receiving additional information about their disease and treatment (61.0%), exercise-related information and support (54.3%), and assistance dealing with fatigue (46.7%). Over 91% expressed interest in at least one specific supportive care service, and 51.4% were interested in one or more psychological services.

CONCLUSION AND IMPLICATIONS FOR CANCER SURVIVORS

Our findings suggest that lung cancer survivors have many unmet needs. Patients who report higher physical distress and intrusive stress symptoms, or lower satisfaction with their health care, may experience the highest level of supportive care need and intervention.

Antibiotics for acute otitis media in children

BACKGROUND

Acute otitis media is one of the most common diseases in early infancy and childhood. Antibiotic use for acute otitis media varies from 31% in the Netherlands to 98% in the USA and Australia.

OBJECTIVES

The objective of this review was to assess the effects of antibiotics for children with acute otitis media.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE, Index Medicus (pre 1965), Current Contents and reference lists of articles from 1958 to January 2000. The search was updated in 2003.

SELECTION CRITERIA

Randomised trials comparing antimicrobial drugs with placebo in children with acute otitis media.

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

Ten trials were eligible based on design, only eight of the trials, with a total of 2,287 children, included patient-relevant outcomes. The methodological quality of the included trials was generally high. All trials were from developed countries. The trials showed no reduction in pain at 24 hours, but a 30% relative reduction (95% confidence interval 19% to 40%) in pain at two to seven days. Since approximately 80% of patients will have settled spontaneously in this time, this means an absolute reduction of 7% or that about 15 children must be treated with antibiotics to prevent one child having some pain after two days. There was no effect of antibiotics on hearing problems of acute otitis media, as measured by subsequent tympanometry. However, audiometry was done in only two studies and incompletely reported. Nor did antibiotics influence other complications or recurrence. There were few serious complications seen in these trials: only one case of mastoiditis occurred in a penicillin treated group.

REVIEWER'S CONCLUSIONS

Antibiotics provide a small benefit for acute otitis media in children. As most cases will resolve spontaneously, this benefit must be weighed against the possible adverse reactions. Antibiotic treatment may play an important role in reducing the risk of mastoiditis in populations where it is more common.

Investigating causes of heterogeneity in systematic reviews

What causes heterogeneity in systematic reviews of controlled trials? First, it may be an artefact of the summary measures used, of study design features such as duration of follow-up or the reliability of outcome measures. Second, it may be due to real variation in the treatment effect and hence provides the opportunity to identify factors that may modify the impact of treatment. These factors may include features of the population such as: severity of illness, age and gender; intervention factors such as dose, timing or duration of treatment; and comparator factors such as the control group treatment or the co-interventions in both groups. The ideal way to study causes of true variation is within rather than between studies. In most situations however, we will have to make do with a study level investigation and hence need to be careful about adjusting for potential confounding by artefactual factors such as study design features. Such investigation of artefactual and true causes of heterogeneity form essential steps in moving from a combined effect estimate to application to particular populations and individuals.

Molecular genetic dissection of TAF25, an essential yeast gene encoding a subunit shared by TFIID and SAGA multiprotein transcription factors

We have performed a systematic structure-function analysis of Saccharomyces cerevisiae TAF25, an evolutionarily conserved, single-copy essential gene which encodes the 206-amino-acid TAF25p protein. TAF25p is an integral subunit of both the 15-subunit general transcription factor TFIID and the multisubunit, chromatin-acetylating transcriptional coactivator SAGA. We used hydroxylamine mutagenesis, targeted deletion, alanine-scanning mutagenesis, high-copy suppression methods, and two-hybrid screening to dissect TAF25. Temperature-sensitive mutant strains generated were used for coimmunoprecipitation and transcription analyses to define the in vivo functions of TAF25p. The results of these analyses show that TAF25p is comprised of multiple mutable elements which contribute importantly to RNA polymerase II-mediated mRNA gene transcription.

Feasibility of an evidence-based literature search service for general practitioners

OBJECTIVE

To test the feasibility of an evidence-based clinical literature search service to help answer general practitioners' (GPs') clinical questions.

DESIGN

Two search services supplied GPs who submitted questions with the best available empirical evidence to answer these questions. The GPs provided feedback on the value of the service, and concordance of answers from the two search services was assessed.

SETTING

Two literature search services (Queensland and Victoria), operating for nine months from February 1999.

MAIN OUTCOME MEASURES

Use of the service; time taken to locate answers; availability of evidence; value of the service to GPs; and consistency of answers from the two services.

RESULTS

58 GPs asked 160 questions (29 asked one, 11 asked five or more). The questions concerned treatment (65%), aetiology (17%), prognosis (13%), and diagnosis (5%). Answering a question took a mean of 3 hours 32 minutes of personnel time (95% CI, 2.67-3.97); nine questions took longer than 10 hours each to answer, the longest taking 23 hours 30 minutes. Evidence of suitable quality to provide a sound answer was available for 126 (79%) questions. Feedback data for 84 (53%) questions, provided by 42 GPs, showed that they appreciated the service, and asking the questions changed clinical care. There were many minor differences between the answers from the two centres, and substantial differences in the evidence found for 4/14 questions. However, conclusions reached were largely similar, with no or only minor differences for all questions.

CONCLUSIONS

It is feasible to provide a literature search service, but further assessment is needed to establish its cost effectiveness.

Histone folds mediate selective heterodimerization of yeast TAF(II)25 with TFIID components yTAF(II)47 and yTAF(II)65 and with SAGA component ySPT7

We show that the yeast TFIID (yTFIID) component yTAF(II)47 contains a histone fold domain (HFD) with homology to that previously described for hTAF(II)135. Complementation in vivo indicates that the yTAF(II)47 HFD is necessary and sufficient for vegetative growth. Mutation of highly conserved residues in the alpha1 helix of the yTAF(II)47 HFD results in a temperature-sensitive phenotype which can be suppressed by overexpression of yTAF(II)25, as well as by yTAF(II)40, yTAF(II)19, and yTAF(II)60. In yeast two-hybrid and bacterial coexpression assays, the yTAF(II)47 HFD selectively heterodimerizes with yTAF(II)25, which we show contains an HFD with homology to the hTAF(II)28 family We additionally demonstrate that yTAF(II)65 contains a functional HFD which also selectively heterodimerizes with yTAF(II)25. These results reveal the existence of two novel histone-like pairs in yTFIID. The physical and genetic interactions described here show that the histone-like yTAF(II)s are organized in at least two substructures within TFIID rather than in a single octamer-like structure as previously suggested. Furthermore, our results indicate that ySPT7 has an HFD homologous to that of yTAF(II)47 which selectively heterodimerizes with yTAF(II)25, defining a novel histone-like pair in the SAGA complex.

D1-Receptor, DARPP-32, and PP-1 in the primate corpus luteum and luteinized granulosa cells: evidence for phosphorylation of DARPP-32 by dopamine and human chorionic gonadotropin

The multifunctional phosphoprotein "dopamine and cAMP-related phosphoprotein, M(r) 32,000" (DARPP-32), which is able to act as an intracellular third messenger, was previously found to be present in human luteinized granulosa cells (GCs) and human ovary. DARPP-32 phosphorylation in GCs was increased by dopamine (DA) acting via a DA-1 receptors (D1-R). In the present study, we examined whether the major endocrine signaling molecule for GCs, LH/human CG (hCG), could also affect DARPP-32 phosphorylation. Immunoprecipitation studies showed that hCG, as well as DA, increased phosphorylation of DARPP-32 at threonine residues within 10 min, indicating that the signal transduction pathways of a hormone and a neurotransmitter involve DARPP-32 in GCs. Phosphorylated DARPP-32 is known to inhibit a cellular phosphatase (PP-1), which was also found to be expressed by GCs. Using RT-PCR and sequence analyses we showed that DARPP-32, PP-1, and D1-R genes were not restricted to cultured luteinized GCs, but were expressed in vivo, in the corpus luteum (CL) of the rhesus monkey throughout its entire life span. Whereas hCG increased steroid production in monkey luteinized GCs and in isolated luteal cells, DA failed to affect basal or hCG-stimulated progesterone production. This indicates that, unlike the LH/hCG receptor, the D1-R is not directly linked to steroid production. Although the precise role of D1-R in the CL remains to be shown, the presence of D1-R, DARPP-32, and its target PP-1 in this endocrine tissue, as well as the phosphorylation of DARPP-32 by a gonadotropin and by DA in luteinized GCs, indicate that the signal transduction pathways of the neurotransmitter DA and the gonadotropin hCG/LH involve DARPP-32. The PP-1 inhibitor DARPP-32 may, thus, be a third messenger used by both DA and hCG/LH to exert common regulatory influences on the cells of the CL.

Identification of two novel TAF subunits of the yeast Saccharomyces cerevisiae TFIID complex

Using a combination of ion exchange and immunoaffinity chromatography we have purified the general transcription initiation factor TFIID to near homogeneity from Saccharomyces cerevisiae. Yeast TFIID is composed of TBP, the TATA box binding protein, and 14 distinct TBP-associated factors (TAFs), which range in size from 17 to 150 kDa. Twelve of the TAF subunits have been previously identified, but two, TAF48p and TAF65p, are novel. TAF48p exhibits significant sequence similarity to the conserved C-terminal region of Drosophila TAF110p, human TAF130p, and human TAF105p and is encoded by a previously identified gene MPT1. TAF65p shows no significant sequence homology to any previously identified TAFp. The genes encoding TAF48p and TAF65p are single copy and essential for normal yeast cell growth. Furthermore, neither TAF48p nor TAF65p are associated with the histone acetylase Spt-Ada-Gcn5 complex or other non-TFIID TBF.TAF complexes. The significance of these results in terms of TFIID structure, function, and organization is discussed.

Antibiotics for acute otitis media in children

BACKGROUND

Acute otitis media is one of the most common diseases in early infancy and childhood. Antibiotic use for acute otitis media varies from 31% in the Netherlands to 98% in the USA and Australia.

OBJECTIVES

The objective of this review was to assess the effects of antibiotics for children with acute otitis media.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register, MEDLINE, Index Medicus, Current Contents and reference lists of articles from 1958 to January 1999.

SELECTION CRITERIA

Randomised trials comparing antimicrobial drugs with placebo in children with acute otitis media.

DATA COLLECTION AND ANALYSIS

Three reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

Nine trials were eligible but only six trials, with a total of 1,962 children, included patient-relevant outcomes. The methodological quality of the included trials was generally high. All trials were from developed countries. The trials showed no reduction in pain at 24 hours, but a 34% relative reduction (95% confidence interval 16% to 48%) in pain at two to seven days. Since approximately 85% of patients will have settled spontaneously in this time, this means an absolute reduction of about 5% or that about 20 children must be treated with antibiotics to prevent one child having some pain after two days. There was no effect of antibiotics on deafness, as measured by subsequent tympanometry, other complications, or recurrence. However, audiometry was done in only two studies and incompletely reported, and there were few serious complications seen in these trials: only one case of mastoiditis occurred (in a penicillin treated group). One semi-randomised trial in Sweden in 1954 reported a rate of 17% in the untreated group versus none in the penicillin treated groups.

REVIEWER'S CONCLUSIONS

Antibiotics provide a small benefit for acute otitis media in children. As most cases will resolve spontaneously, this benefit must be weighed against the possible adverse reactions. Antibiotic treatment may play an important role in reducing the risk of mastoiditis in populations where it is more common.

TAF25p, a non-histone-like subunit of TFIID and SAGA complexes, is essential for total mRNA gene transcription in vivo

We demonstrate, utilizing a temperature conditional mutant allele of the gene encoding TAF25p, that this non-histone-like TBP-associated factor, which is shared between the TFIID and SAGA complexes, is required for bulk mRNA gene transcription by RNA polymerase II in vivo. Immunoblotting experiments indicate that at the restrictive temperature, inactivation of TAF25p function results in a reduction of the levels of numerous TFIID and SAGA subunits, indicating its loss of function, like the histone-like TAFs, causes degradation of the constituents of these two multisubunit complexes. These data suggest that TAF25p plays a key structural role in maintaining TFIID and SAGA complex integrity. This is the first demonstration that a non-histone-like TAF is required for continuous, high level RNA polymerase II-mediated mRNA gene transcription in living yeast cells.

O-Glycosylation of Axl2/Bud10p by Pmt4p is required for its stability, localization, and function in daughter cells

Cells of the yeast Saccharomyces cerevisiae choose bud sites in a manner that is dependent upon cell type: a and alpha cells select axial sites; a/alpha cells utilize bipolar sites. Mutants specifically defective in axial budding were isolated from an alpha strain using pseudohyphal growth as an assay. We found that a and alpha mutants defective in the previously identified PMT4 gene exhibit unipolar, rather than axial budding: mother cells choose axial bud sites, but daughter cells do not. PMT4 encodes a protein mannosyl transferase (pmt) required for O-linked glycosylation of some secretory and cell surface proteins (Immervoll, T., M. Gentzsch, and W. Tanner. 1995. Yeast. 11:1345-1351). We demonstrate that Axl2/Bud10p, which is required for the axial budding pattern, is an O-linked glycoprotein and is incompletely glycosylated, unstable, and mislocalized in cells lacking PMT4. Overexpression of AXL2 can partially restore proper bud-site selection to pmt4 mutants. These data indicate that Axl2/Bud10p is glycosylated by Pmt4p and that O-linked glycosylation increases Axl2/ Bud10p activity in daughter cells, apparently by enhancing its stability and promoting its localization to the plasma membrane.

Predictors of severity of absenteeism in children with anxiety-based school refusal

Examined possible relations among sociodemographic, clinical, and familial variables and level of school absenteeism in children with anxiety-based school refusal. These children exhibit a great deal of variability in the severity of school refusal, with some youngsters missing only an occasional day of school, whereas other exhibit pervasive school absenteeism. Participants were 76 children referred for treatment of anxiety-based school refusal. Children and a parent completed a structured clinical interview (Schedule for Affective Disorders and Schizophrenia for School-Age Children) and self-report measures that assess children's levels of fear (Fear Survey Schedule for Children-Revised), trait and somatic anxiety (Modified State-Trait Anxiety Inventory for Children), and depressive symptomatology (Children's Depression Inventory), as well as family environment characteristics (Family Environment Scale). Regression analyses revealed that older age, lower levels of fear, and less active families were primary predictors of greater levels of school absenteeism.

Localization of steroidogenic enzymes in macaque luteal tissue during the menstrual cycle and simulated early pregnancy: immunohistochemical evidence supporting the two-cell model for estrogen production in the primate corpus luteum

It is hypothesized that the two-cell model for estrogen production by the ovarian follicle is preserved in the primate corpus luteum, but there is little direct evidence to support this theory. To determine the sites of androgen and estrogen synthesis within the primate corpus luteum and to ascertain whether changes in steroid hormone levels are related to steroidogenic enzyme expression, the enzymes converting progesterone to androgen (cytochrome P450 17alpha-hydroxylase/17,20 lyase; P450(c17)) and then to estrogen (aromatase; P450(arom)), as well as P450 side-chain cleavage (P450(scc)) and 3beta-hydroxysteroid dehydrogenase (3beta HSD), were detected by immunohistochemistry in macaque luteal tissue throughout the menstrual cycle and simulated early pregnancy. Corpora lutea were collected from rhesus monkeys in the early (Days 2-4 post-LH surge), mid (Days 6-8), mid-late (Days 10-12), and late (Days 14-15) luteal phase and after 1, 3, 6, or 9 days of hCG treatment that began on Day 9 of the luteal phase. Specific cytoplasmic staining for P450(c17), P450(arom), P450(scc), and 3beta HSD was present in luteal cells, but not in the microvasculature, within all luteal tissues examined. P450(c17)-stained luteal cells were located along the vascular tracts and around the periphery of the corpus luteum. Intensely stained luteal cells were associated with blood vessels entering from the outer surface of the corpus luteum, but not with blood vessels returning from the connective tissue centrum. In contrast, P450(arom)-stained luteal cells were distributed throughout the luteal parenchyma. P450(c17) staining intensity was similar at all stages of the luteal phase; however, the number and intensity of P450(arom)-stained cells decreased by late luteal phase. In simulated early pregnancy, cells stained for P450(c17) were present near blood vessels, with some positive cells scattered throughout the corpus luteum. P450(arom) immunostaining was heterogeneous within the corpus luteum; many intensely stained cells were interspersed among others that were only lightly stained. Overall, cellular staining for P450(c17) and P450(arom) remained intense through 9 days of simulated early pregnancy. In contrast, P450(scc) and 3beta HSD immunoreactivity were not located in distinct luteal compartments. These results are consistent with a two-cell model for steroid hormone production in the primate corpus luteum, whereby paraluteal (theca-luteal) cells produce androgen substrate that is converted to estrogens by true (granulosa-) luteal cells. The divergence in enzyme detection as the luteal phase progresses, with P450(c17) labeling high and P450(arom) staining having decreased, suggests a shift in the function of the corpus luteum as it ages. Enzyme localization during chorionic gonadotropin exposure simulating early pregnancy demonstrates the continued capacity of the primate corpus luteum to produce steroid hormones.

The BUD4 protein of yeast, required for axial budding, is localized to the mother/BUD neck in a cell cycle-dependent manner

A and alpha cells of the yeast Saccharomyces cerevisiae exhibit an axial budding pattern, whereas a/alpha diploid cells exhibit a bipolar pattern. Mutations in BUD3, BUD4, and AXL1 cause a and alpha cells to exhibit the bipolar pattern, indicating that these genes are necessary to specify the axial budding pattern (Chant, J., and I. Herskowitz. 1991. Cell. 65:1203-1212; Fujita, A., C. Oka, Y. Arikawa, T. Katagi, A. Tonouchi, S. Kuhara, and Y. Misumi. 1994. Nature (Lond.). 372:567-570). We cloned and sequenced BUD4, which codes for a large, novel protein (Bud4p) with a potential GTP-binding motif. Bud4p is expressed and localized to the mother/bud neck in all cell types. Most mitotic cells contain two apparent rings of Bud4 immunoreactive staining, as observed for Bud3p (Chant, J., M. Mischke, E. Mitchell, I. Herskowitz, and J.R. Pringle. 1995. J. Cell Biol. 129: 767-778). Early G1 cells contain a single ring of Bud4p immunoreactive staining, whereas cells at START and in S phase lack these rings. The level of Bud4p is also regulated in a cell cycle-dependent manner. Bud4p is inefficiently localized in bud3 mutants and after a temperature shift of a temperature-sensitive mutant, cdc12, defective in the neck filaments. These observations suggest that Bud4p and Bud3p cooperate to recognize a spatial landmark (the neck filaments) during mitosis and support the hypothesis that they subsequently become a landmark for establishing the axial budding pattern in G1.

Bile salt inhibits acid-promoting feeding tube occlusion

Occlusion of feeding tubes is a common and costly complication of enteral feeding. Although the composition of feeding formulas, the size, design, and material of the feeding tube, and the rate of delivery have been considered as factors that determine the rate of tube occlusion, little information is available on the effect of the luminal content of the gut on tube occlusion. Enteral feeding tubes are placed either in the stomach or postpylorically, in the small intestine. The chemical composition of these regions including acidity and bile salt concentration may vary. Since acidity has been shown to promote tube occlusion and bile salts have detergent-like properties, these chemical differences in the luminal environment may be important to tube occlusion. To test the idea that bile salt inhibits acid-promoted occlusion of feeding tubes, in an in vitro study, we compared the time-to-complete occlusion of four groups of formula-filled feeding tubes (six tubes in each group) immersed in an acidic solution (pH 3.0) containing 0 (control), 10, 20, or 40 mM of taurocholate. We found that although 33% of the feeding tubes were occluded within 12 hours in the absence of exposure to bile salt, none were occluded when 20 or 40 mM of taurocholate was added to the acidic solution. After 24 hours, 40 mM of taurocholate inhibited acid-promoted occlusion of 67% of the feeding tubes. Thus 0 to 40 mM of taurocholate still inhibited acid-promoted tube occlusion in a dose-dependent fashion (p < .05). Acidity and the concentration of bile salt may work together, but in opposite directions, as luminal factors that determine the rate of occlusion of feeding tubes.

Androgen production by monkey luteal cell subpopulations at different stages of the menstrual cycle

Androgens produced by the primate corpus luteum (CL) serve as precursors for estrogen synthesis; moreover, detection of androgen receptors in luteal tissue suggests a regulatory role within the CL. To determine the cellular source(s) and agonist regulation of androgen production during the lifespan of the primate CL, luteal tissues were collected from rhesus monkeys in the early (days 3-5 post-LH surge), mid (days 7-8), mid-late (days 11-12), and late (days 14-15) luteal phase of the menstrual cycle. Collagenase-dispersed cells (i.e., mixed cells) were analyzed by flow cytometry based on light scatter properties and sorted into populations of small (< or = 15 microns) and large (> 20 microns) luteal cells. Cells (n = 4 animals/stage) were incubated in Ham's F-10 and 0.1% BSA for 3 h at 37 C with or without hCG (100 ng/mL), PGE2 (14 mumol/L), or dibutyryl cAMP (dbcAMP; 5 mmol/L), and androstenedione (A4) and testosterone were measured. Basal A4 production by large cells was markedly higher (P < 0.05) than that by small cells (e.g. mid-late luteal phase, 821 +/- 188 vs. 69 +/- 25 pg/mL.5 x 10(4) cells/3 h; mean +/- SEM), whereas that by mixed cells was intermediate (317 +/- 205 pg/mL). In the early luteal phase, hCG stimulated A4 synthesis by mixed (1.6-fold; P < 0.05) and large (3.1-fold; P < 0.05) luteal cells, but not by small cells (1.3-fold). By the mid-late luteal phase, hCG did not increase A4 production by any cell type, although hCG responsiveness returned to large cells (2.0-fold increase; P < 0.05) by the late luteal phase. PGE2 responsiveness by cell types was similar to that of hCG, except large cell responsiveness did not return in the late luteal phase. In all cell types, dbcAMP stimulated the largest increase in A4 levels; in the mid-late luteal phase, small and large cells responded to dbcAMP with 8.2- and 3.0-fold increases (P < 0.05) in A4 production, respectively. When luteal cells were incubated with the steroidogenic substrates, 17 alpha-hydroxyprogesterone or 17 alpha-hydroxypregnenolone (1 mumol/L), large cells produced much more (P < 0.05) A4, testosterone, estrone, and estradiol than small cells. Both substrates elicited similar patterns of androgen production, with A4 synthesis predominant in all luteal cell types. Thus, cell subpopulations in the primate CL can be distinguished by their ability to produce androgen and estrogen. Changes in agonist-responsive androgen production may influence the local steroid milieu and function of the CL during the menstrual cycle.

Cell division. Bud-site selection is only skin deep

Yeast cells that divide by budding place new buds in predetermined locations. Recent studies of the subcellular localization of the Bud3 protein help to explain how this occurs.

Gonadotropin- and lipoprotein-supported progesterone production by primate luteal cell types in culture

This study examined the ability of gonadotropin and lipoproteins to support progesterone (P) production during long-term culture of luteal cell types obtained from rhesus macaques at midluteal phase of the menstrual cycle. Mixed (unsorted) luteal cells and small and large cells sorted by flow cytometry were cultured with human IDL, acetylated (ac)LDL or high density lipoprotein (HDL) (0-100 μg protein/ml) with or without hCG (100 ng/ml). In mixed cells, daily P levels declined during culture, although treatment with hCG alone increased P levels on all days of culture. Treatment with LDL, acLDL or HDL alone had no effect on P levels. However, hCG + LDL sustained P levels through day 4 at or above day 1 control values. Treatment with hCG + acLDL also increased P production above that of hCG alone, but hCG + HDL only modestly enhanced P production (180%). Although hCG stimulated P production by freshly-harvested large, but not small, cells during acute (3h) incubation, both cell types responded to hCG with up to an eightfold increase in P production on days 1-4 of culture. P levels were essentially nondetectable in both sorted cell groups by day 4. Small cells did not respond to any of the three lipoprotein treatments; large cells responded to LDL or acLDL on day 1, but this response was not apparent later in culture. Treating small or large cells with hCG + lipoprotein was no different from hCG alone. Thus, (1) LDL, and to some extent modified LDL, supports gonadotropinstimulated steroidogenesis by mixed cell populations in the monkey corpus luteum; (2) the lack of LDL response by sorted cell types suggests that the culture conditions or absence of other cell types renders lipoprotein treatment ineffective; and (3) small luteal cells develop the cellular components necessary for gonadotropin-stimulated steroidogenesis within 24 h of culture.

Cell division. Septins in common?

Two apparently quite distinct processes, cytokinesis in animal cells and in budding yeast cells, have been shown to involve proteins of the same family, the septins, suggesting that the two may not be so different after all.

Erythromycin accelerates solid emptying at the expense of gastric sieving

Erythromycin accelerates gastric emptying by inducing antral contractions similar to phase III of interdigestive MMC. These powerful contractions are capable of forcing coin-sized indigestibles out of the stomach. In contrast, fed motility is associated with submaximal contractions that fragment (trituration) and propel solids while retaining large (> 0.5 mm) pieces for further size reduction (gastric sieving). In this study, using dogs with duodenal fistulas, we tested the hypothesis that erythromycin-induced acceleration of gastric emptying resulted in the passage of inadequately triturated (> 0.05 mm) chunks of solids into the duodenum. We found that gastric emptying was accelerated by erythromycin (vs 0.15 M NaCl control, P < 0.05). However, the percentage of chyme collected in the > 0.5-mm fraction was much greater (P < 0.01) in the erythromycin-treated experiments (63 +/- 9%) than the controls (7 +/- 1%). Correspondingly, while a fine gruel was passed during controls, under erythromycin infusion, most of the solids were emptied as large chunks virtually unchanged from the swallowed pieces. We conclude that erythromycin accelerates gastric emptying at the expense of gastric sieving.

Polypeptide translocation across the endoplasmic reticulum membrane

Many polypeptides have been postulated to play direct roles in secretory protein translocation based on genetic criteria, cross-linking, and antibody inhibition. Much of the excitement in the next few years will come from the resolution of current controversies. What is the nature of the ribosome receptor, and is it essential for translocation? Is BiP required for translocation in mammalian cells? Are all of the polypeptides of signal peptidase and oligosaccharyltransferase required for catalytic function, or do some of them mediate steps of protein translocation? One of the best ways to resolve these problems will be to determine the importance of each in reconstituted translocation reactions by fractionation or immunodepletion, or by analysis in a purified reaction. Another approach is to identify homologues of these molecules in S. cerevisiae and to assess their importance in in vivo translocation. Several mechanistic questions remain to be addressed as well. Does the protein translocation apparatus consist of protein, or lipid, or both? How are integral membrane proteins inserted? How is the translocon gated to admit only unfolded or partially folded secretory polypeptides and to exclude cytoplasmic molecules? The answers to these questions will illuminate a basic enigma in cell biology that has remained unanswered for many years.

Pressure ulcers, Part two: Management strategies

The goal of this article is to facilitate the successful resolution of pressure ulcers. The nurse practitioner (NP) is an ideal health care professional to manage pressure ulcer care. This article reviews the basic principles related to wound care. The healing trajectory is discussed to assist an NP to determine appropriate therapy. Current, research-based management strategies are provided.

Sec61p and BiP directly facilitate polypeptide translocation into the ER

Secretory proteins are segregated from cytosolic proteins by their translocation into the endoplasmic reticulum (ER). A modified secretory protein trapped during translocation across the ER membrane can be crosslinked to two previously identified proteins, Sec61p and BiP (Kar2p). The dependence of this cross-linking upon proteins and small molecules was examined. Mutations in SEC62 and SEC63 decrease the ability of Sec61p to be cross-linked to the secretory polypeptide trapped in translocation. ATP is also required for interaction of Sec61p with the secretory protein. Three kar2 alleles display defective translocation in vitro. Two of these alleles also decrease the ability of Sec61p to be cross-linked to the secretory protein. The third allele, while exhibiting a severe translocation defect, does not affect the interaction of Sec61p with the secretory protein. These results suggest that Sec61p is directly involved in translocation and that BiP acts at two stages of the translocation cycle.

Pressure ulcers, Part 1: Prevention strategies

Pressure ulcers are a costly health concern. Many can be prevented by conscientious, vigorous nursing care. The nurse practitioner (NP) is an ideal professional to direct preventive care and to manage the treatment of ulcers. This article reviews the multiple risk factors and dynamics involved in the development of pressure ulcers, and preventive measures that can be implemented. The role of an NP related to pressure ulcer prevention and specific NP interventions are discussed.

Cellular localization of ovarian proopiomelanocortin messenger RNA during follicular and luteal development in the rat

Opioid peptides are expressed in the reproductive system and have been reported to regulate reproductive function. The present study used in situ hybridization to selectively localize ovarian cells containing high levels of proopiomelanocortin (POMC) mRNA, an opioid precursor, during different stages of ovarian development. Prepubertal rats were primed with PMSG to stimulate follicular development, followed by hCG to induce ovulation. Treatment groups consisted of control (no treatment), PMSG (2 days post-PMSG), 1 day corpus luteum (CL; 1 day post-hCG), and 8 day CL (8 days post-hCG). POMC mRNA-containing cells were present in antral follicles, CL, and the interstitial compartment. With gonadotropin treatment, the percentage of follicles containing heavily labeled cells increased in the PMSG and 1 day CL groups. The number of POMC mRNA-containing cells per follicle also increased in the 1 day CL group. In the CL, no difference was observed in the percentage of CL exhibiting labeled cells between the 1 day CL and 8 day CL groups; however, more labeled luteal cells per CL were present in the 1 day CL group. A marked increase in POMC mRNA-containing cells was observed in the interstitial compartment of the 1 day CL group. These results indicate that the number of POMC mRNA-containing cells increases with follicular development and CL formation; however, the ovarian distribution suggests that the labeled cells could be nonendocrine cells, possibly white blood cells. The in situ hybridization findings are indicative of low total concentrations of ovarian POMC mRNA, suggesting mainly an autocrine or paracrine role for POMC or POMC-derived peptides.(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple genes are required for proper insertion of secretory proteins into the endoplasmic reticulum in yeast

Genes that function in translocation of secretory protein precursors into the ER have been identified by a genetic selection for mutant yeast cells that fail to translocate a signal peptide-cytosolic enzyme hybrid protein. The new mutants, sec62 and sec63, are thermosensitive for growth and accumulate a variety of soluble secretory and vacuolar precursors whose electrophoretic mobilities coincide with those of the corresponding in vitro translated polypeptides. Proteolytic sensitivity of precursor molecules in extracts of mutant cells confirms that polypeptide translocation is blocked. Some form of interaction among the SEC61 (Deshaies, R. J., and R. Schekman. 1987. J. Cell Biol. 105:633-645), SEC62 and SEC63 gene products is suggested by the observation that haploid cells containing any pair of the mutations are inviable at 24 degrees C and show a marked enhancement of the translocation defect. The translocation defects of two mutants (sec62 and sec63) have been reproduced in vitro. sec63 microsomes display low and thermolabile translocation activity for prepro-alpha-factor (pp alpha F) synthesized with a cytosol fraction from wild type yeast. These gene products may constitute part of the polypeptide recognition or translocation apparatus of the ER membrane. Pulse-chase analysis of the translocation-defective mutants demonstrates that insertion of pp alpha F into the ER can proceed posttranslationally.

The role of ovarian proteases and their inhibitors in ovulation

To assess the role of inhibitors of proteolytic enzymes, such as plasminogen activator (PA) and collagenase in the ovulatory process, inhibitor activity and mRNA levels were examined in periovulatory rat and human ovaries. In the rat, immature animals received 20 IU of pregnant mare serum gonadotropin (PMSG) followed 52 h later by 10 IU of hCG. Ovaries were removed at intervals from 0 to 20 h after human chorionic gonadotropin (hCG) administration. Inhibitor activity for metalloproteinases, such as collagenase, increased from 60.5 +/- 4.1 inhibitor units/ovary at 0 h (i.e., time of hCG treatment) to a maximum of 218.2 +/- 11.4 units/ovary at 8 h after hCG before decreasing at 12 h (time of ovulation) and 20 h (122.2 +/- 7.9 and 71.6 +/- 8.1 units/ovary, respectively). Human follicular fluid and granulosa cells were obtained from preovulatory follicles of patients in our in vitro fertilization program. Metalloproteinase inhibitor activity was evaluated in follicular fluid as well as the levels of PA and PA inhibitor (PAI) mRNA by Northern analysis. Increasing metalloproteinase inhibitor activity was positively correlated with follicular levels of estradiol (p less than 0.001) and progesterone (p less than 0.02, N = 26). Chromatographic separation of follicular fluid resulted in two peaks of metalloproteinase inhibitor activity. The large molecular weight (MW) inhibitor had an approximate size of 700 kilodaltons (kDa) and may represent alpha 2-macroglobulin, a serum-derived inhibitor. The small MW inhibitor shared many of the characteristics of tissue-derived inhibitors of metalloproteinases. Partial purification of the small MW inhibitor by Concanavalin A-Sepharose and Heparin-Sepharose chromatography demonstrated the inhibitor to be a glycoprotein with an approximate MW = 28-29 K. Northern analysis of human granulosa cell total RNA from preovulatory follicles showed little or no detectable tissue-type PA or urokinase-type PA mRNA. In contrast, two species of PA inhibitor type-1 mRNA were detected in relative abundance. The present findings demonstrate the presence of proteolytic inhibitors in periovulatory ovaries of the rat and human. These ovarian inhibitors may play a role in regulating connective tissue remodeling during follicular rupture.

Identification and characterization of metalloproteinase inhibitor activity in human ovarian follicular fluid

Metalloproteinase inhibitors regulate collagenase activity in the extracellular matrix. To assess the role of metalloproteinase inhibitors in the ovulatory process, inhibitor activity was examined in human follicular fluid collected 2-4 h before ovulation. The relationship between inhibitor activity and steroid content was determined, and the inhibitors were partially purified and characterized. Inhibitory activity in follicular fluid (n = 25) correlated with both follicular estradiol (P less than 0.001) and progesterone (P less than 0.02) concentrations per follicle. Chromatographic separation of the follicular fluid on Sepharose 6B isolated two peaks of inhibitory activity. The inhibitor from the small mol wt (Mr) peak shared many of the properties of tissue inhibitors of metalloproteinase. It was stable in response to heat (60 C) and methylamine (200 mM), and was destroyed by reduction and alkylation, a procedure reported to destroy previously characterized inhibitors. Partial purification by affinity and ion exchange chromatography demonstrated the inhibitor to be a glycoprotein with an approximate Mr of 28-29K. The large Mr inhibitor had an approximate size of 700K and exhibited many of the characteristics of alpha 2-macroglobulin, a serum-derived metalloproteinase inhibitor. It was sensitive to heat, methylamine, and reduction and alkylation. Thus, follicular fluid contains metalloproteinase inhibitor activity that is steroid related and may be hormonally regulated. Ovarian metalloproteinase inhibitors may act to regulate connective tissue remodeling during follicular rupture.

Spontaneous regression of a giant keratoacanthoma. Photographic documentation and histopathologic correlation

An 84-year-old woman developed a keratoacanthoma on the dorsum of her left hand. Photographic documentation of spontaneous resolution of the lesion over a period of eight months is presented. Biopsy of the site of the resolving lesion revealed extensive scarring and granulomatous inflammation.

Salmonella typhimurium pancreatic abscess: report of a case

A case of pancreatic abscess from Salmonella typhimurium is reported. After surgical drainage of the abscess, positive stool cultures persisted. Finally, after intensive antimicrobial therapy with tetracycline and chloramphenicol, and cholecystectomy, stool cultures became negative. This is, to our knowledge, the first published case of S. typhimurium pancreative abscess.