Possible community immunity to small round structured virus gastroenteritis in a rural aboriginal community

In April 1998 an outbreak of gastroenteritis affected visitors, but none of the Aboriginal residents, at a Territory Health Services luncheon in a rural Aboriginal community in Central Australia. The epidemiological features and identification of Small Round Structured Virus (SRSV) from two participants suggest that this was an outbreak caused by a SRSV. The attack rate in the visitors who ate or drank food at the luncheon was 73% (11 of 15). Seventeen Aboriginal residents were interviewed, none had gastroenteritis. The community potable water supply was contaminated with faecal bacteria around the time of the outbreak. No particular food could be implicated and laboratory examination of foods was not possible. It is proposed that past exposure to SRSVs may have resulted in the Aboriginal residents developing clinical immunity to infection. The process and consequences of the investigation in this community are also discussed.

High sequence homology between human and pig CD40 with conserved binding to human CD154

BACKGROUND

Understanding the molecular interactions between pig tissues and human immune cells is fundamental to achieving long-term pig to human xenograft survival. CD40 has been shown to be central in the interaction of T cells with many antigen-presenting cells including B cells, and dendritic cells. It has been clearly shown in vitro that human T cells can effectively recognize pig major histocompatibility complex proteins, and that various accessory molecule interactions are compatible between these species, including human CD28 with pig B7 family members (CD80/CD86). The importance of CD40 in transplantation has been established using blocking antibodies to its ligand, CD154, which prolong allograft survival in mouse and primate models.

METHODS

Pig CD40 was cloned from a porcine spleen cDNA library and subsequently sequenced. Expression of pig CD40 was detected by flow cytometry using soluble human CD154 (hCD154-Ig). Results. Comparison of the derived amino acid sequence of pig with human shows 74% identity. Significantly, there is conservation between pig and human at 5 residues shown by mutagenesis studies to be essential for binding of human CD40 to CD154. hCD154Ckappa was shown to bind pig B cell lines and a proportion of human and pig lymphocytes and further confirmed by staining of COS cells transfected with pig CD40. Conclusions. Recipient human cells bearing CD154 will, therefore, be able to bind donor pig CD40, and these interactions might modulate effector functions and hence influence xenograft survival. Further investigation is necessary to ascertain the exact nature of these interactions and their implications for xenograft survival.

Silent lacunar lesions detected by magnetic resonance imaging of children with brain tumors: a late sequela of therapy

BACKGROUND

Cerebral lacunes, which generally appear on magnetic resonance imaging as foci of white matter loss, usually occur in adults after ischemic infarcts. We report the development of lacunes in children after therapy for brain tumors.

PATIENTS AND METHODS

We reviewed the clinical characteristics and radiologic studies of 524 consecutive children with brain tumors treated over a 10-year period. We documented the neuropsychologic findings associated with lacunes and the factors predictive of lacunar development.

RESULTS

Lacunes developed in none of the 103 patients observed or treated with surgery alone. Twenty-five of the 421 patients treated with chemotherapy or radiation therapy or both had lacunes. Patients were a median of 4.5 years old at the time of both diagnosis (range, 0.3 to 19.8 years) and radiotherapy (range, 1.5 to 20 years). Fourteen patients were treated with craniospinal irradiation, and 11 were treated with local radiotherapy. The median time from radiotherapy to the appearance of lacunes was 2.01 years (range, 0.26 to 5.7 years). For all patients, lacunes were an incidental finding with no corresponding clinical deficits. The factor most predictive of lacunar development was age less than 5 years at the time of radiotherapy (P =.010). There was no significant difference in estimated decline in intelligence quotient scores between patients with lacunes and age and diagnosis-matched controls.

CONCLUSION

Lacunes may be caused by therapy-induced vasculopathy in children with brain tumors, with the most significant predictor being age less than 5 years at the time of radiotherapy.

Etiology of travelers' diarrhea on a Caribbean island

BACKGROUND

Between December 6, 1994 and March 10, 1996, a study of the etiology of diarrhea was carried out among 332 travelers to five all-inclusive hotels in Negril, Jamaica.

METHODS

Stool specimens were collected and sent to Montego Bay for laboratory analysis. Escherichia coli strains isolated at the Jamaican laboratory were sent to Houston for toxin testing.

RESULTS

A recognized enteropathogen was found in 118 of the 332 (35.5%) cases. Enterotoxigenic E. coli (ETEC) were the most commonly identified pathogen (87/332; 26.2%) followed by Salmonella (4.2%) and Shigella (4.2%). Clustering of etiologically defined cases was studied at each hotel. A cluster was defined as 2 or more cases with the same pathogen identified in the same hotel within 7 days. In the 3 hotels with the highest number of cases of diarrhea, enteropathogens were part of a cluster in 65 of 99 cases (65.7%) of diarrhea of which an etiologic agent was identified. In the other 2 hotels, only 4 of 20 cases (20%) occurred in clusters.

CONCLUSIONS

A total of 25 clusters of travelers' diarrhea cases was detected at the five hotels during the study period. Seventeen of 25 (68%) ETEC isolations occurred as part of a clustering of diarrhea cases. The largest outbreak of pathogen-identified diarrhea consisted of 7 cases of ETEC producing both heat-stable and heat-labile enterotoxins. In the Jamaican hotels with all inclusive meal packages most diarrhea cases occurred as small clusters, presumably as the result of foodborne outbreaks.

Project GRAD: two-year outcomes of a randomized controlled physical activity intervention among young adults. Graduate Ready for Activity Daily

INTRODUCTION

Project Graduate Ready for Activity Daily evaluated a program to promote physical activity through the transition of university graduation in a randomized controlled trial.

METHODS

Three hundred thirty-eight university seniors participated in either a cognitive-behavioral intervention course or a knowledge-oriented general health course during the semester before graduation. Behaviorally oriented phone and mail follow-up was delivered to the intervention group for 18 months. Physical activity outcomes and mediating variables were assessed at baseline, 1 and 2 years (93% retention rate).

RESULTS

There were no significant intervention effects on physical activity outcomes at 2 years for either men or women. Experiential and behavioral processes of change were significantly improved for intervention women over 2 years.

CONCLUSIONS

Despite excellent participation in a theoretically based, well-attended intervention, few long-term effects on physical activity or its mediators were found. Additional research is needed to determine optimal interventions for physical activity and to validate or alter current behavior change theory.

Risk factors for hepatitis C transmission in the Victorian population: a telephone survey

OBJECTIVE

To measure knowledge and prevalences of risk factors for hepatitis C infection in the Victorian community.

METHOD

Telephone survey of 757 Victorian householders aged 15+ years, March 1996.

RESULTS

An estimated 2.2% of Victorians have injected illicit drugs; 4.8% have tattoos and 49.6% have skin piercings; 11.4% received a blood transfusion before screening for HCV was introduced; 10.9% have had a test for HCV antibody. A majority of respondents perceived sexual contact and receipt of a transfusion to be risks for HCV transmission.

CONCLUSIONS

Risk factors associated with the spread of HCV are widespread in the Victorian community; however, the most important risk factor--injecting drug use--has low prevalence. Considerable uncertainty exists about risk factors for hepatitis C.

IMPLICATIONS

A very small percentage of Victorians are injecting drug users and therefore at highest risk of hepatitis C infection, therefore transmission control programs can be efficiently focused on this group. The Victorian community needs to be better educated about risk factors for hepatitis C, in particular that transfusions and blood donations are safe.

Incentives and accessibility: a pilot study to promote adherence to TB prophylaxis in a high-risk community

SETTING

A community-based directly observed preventive therapy (DOPT) program for treatment of latent tuberculosis infection among injection drug users (IDUs) in an inner-city neighborhood.

OBJECTIVE

To test adherence to a 6-month course of DOPT using cash incentives and an easily accessible neighborhood location.

DESIGN

Street-recruited IDUs (N = 205) were screened for Mycobacterium tuberculosis (TB) infection using the Mantoux test and two controls. Subjects who had a purified protein derivative (PPD) reaction of > or =5 mm, were anergic, or had a history of a positive PPD received clinical evaluation at a community field site, provided in collaboration with the San Francisco Department of Public Health Tuberculosis Clinic. Twenty-eight subjects were considered appropriate candidates for prophylaxis with isoniazid, and 27 enrolled in the pilot study. Participants received twice-weekly DOPT at a community satellite office, with a $10 cash incentive at each visit.

RESULTS

The 6-month (26-week) regimen was completed by 24/27 (89%) participants. The median time to treatment completion was 27 weeks (range 26 to 34 weeks). The median proportion of dosing days attended in 6 months was 96%.

CONCLUSION

Community-based DOPT using cash incentives resulted in high levels of adherence and treatment completion among drug users.

Heterozygous factor XI deficiency associated with three novel mutations

To determine the utility of single-stranded conformation polymorphism (SSCP) analysis for screening mutations in the factor XI (fXI) gene, we investigated three patients with heterozygous factor XI deficiency. DNA sequence analysis confirmed three novel mutations; a CGC --> TGC (Arg308Cys) mutation in exon 9, a GCT-->GTT (Ala412Val) mutation in exon 11 and an AGC --> AGA (Ser576Arg) mutation in exon 15. We postulated on the structural implications of these missense mutations. Our results demonstrated that genotypic analysis is a useful tool for conclusive differentiation between heterozygous factor XI deficiency and normal subjects.

Mechanism of inhibition of cathepsin K by potent, selective 1, 5-diacylcarbohydrazides: a new class of mechanism-based inhibitors of thiol proteases

The nature of the inhibition of thiol proteases by a new class of mechanism-based inhibitors, 1,5-diacylcarbohydrazides, is described. These potent, time-dependent, active-site spanning inhibitors include compounds that are selective for cathepsin K, a cysteine protease unique to osteoclasts. The 1,5-diacylcarbohydrazides are slow substrates for members of the papain superfamily with inhibition resulting from slow enzyme decarbamylation. Enzyme-catalyzed hydrolysis of 2,2'-N, N'-bis(benzyloxycarbonyl)-L- leucinylcarbohydrazide is accompanied by formation of a hydrazide-containing product and a carbamyl-enzyme intermediate that is sufficiently stable to be observed by mass spectrometry and NMR. Stopped-flow studies yield a saturation limited value of 43 s(-)(1) for the rate of cathepsin K acylation by 2,2'N, N'-bis(benzyloxycarbonyl)-L-leucinylcarbohydrazide. Inhibition potency varies among proteases tested as reflected by 2-3 orders of magnitude differences in K(i) and K(obs)/I, but all eventually form the same stable covalent intermediate. Reactivation rates are equivalent for all enzymes tested (1 x 10(-)(4) s(-)(1)), indicating hydrolysis of a common carbamyl-enzyme form. NMR spectroscopic studies with cathepsin K and 2,2'-N,N'-bis(benzyloxycarbonyl)-L-leucinylcarbohydrazide provide evidence of inhibitor cleavage to generate a covalent carbamyl-enzyme intermediate rather than a tetrahedral complex. The product Cbz-leu-hydrazide does not appear enzyme-bound after cleavage in the NMR spectra, suggesting that the stable inhibited form of the enzyme is the thioester complex. 1, 5-diacylcarbohydrazides represent a new class of unreactive cysteine protease inhibitors that share a common mechanism of action across members of the papain superfamily. Both S and S' subsite interactions are exploited in achieving high selectivity and potency.

The effect of importance level, delay, and rate of forgetting on prose recall in multiple sclerosis

Memory deficits are frequently seen in patients with multiple sclerosis (MS). The focus of this study was to examine semantic encoding and the rate of forgetting in MS patients. The prose passages of the Wechsler Memory Scale Logical Memory subtest were used to examine MS patients' semantic sensitivity to the idea units of a story. The stories were divided into high, medium, and low idea units, reflecting their overall importance to the meaning of the story. MS patients recalled fewer idea units than controls, but both groups favored the main ideas relative to the nonessential details at both the immediate and delayed recall of the passages. Likewise, MS patients forgot information at a much faster rate than controls. Implications of this faster forgetting rate in MS patients are discussed from an applied setting.

Infectious mononucleosis in an outpatient population: diagnostic utility of 2 automated hematology analyzers and the sensitivity and specificity of Hoagland's criteria in heterophile-positive patients

OBJECTIVES

To determine the sensitivity and specificity of 2 modern hematology analyzers in flagging heterophile-positive patients; to determine if heterophile-positive, instrument-flagged specimens contain a larger number or a different spectrum of atypical lymphocytes; to document the overall sensitivity and specificity of Hoagland's morphologic criteria in identifying heterophile-positive patients in an outpatient population with a clinical diagnosis of mononucleosis; and to examine whether individual morphologic features might aid in the diagnosis of suspected infectious mononucleosis.

DESIGN

A prospective study of patients referred with a clinical diagnosis of infectious mononucleosis who subsequently tested positive for the heterophile antibody. The control group consisted of a similar population of patients who tested negative for the heterophile antibody.

INTERVENTION

Hematology profiles of peripheral blood samples were determined with Coulter STKS and Sysmex NE-8000 analyzers. A corresponding Wright-Giemsa-stained blood smear was subsequently examined by a single skilled technologist, who performed a 200-cell white blood cell differential and a 200-cell lymphocyte differential. A specific morphologic search was made for the presence of smudge cells or lymphocytes with cloverleaf nuclei.

RESULTS

Using a combination of all flagging criteria, the 2 analyzers identified 156 (86.2%) of 181 heterophile-positive patients as meriting further review. The sensitivity and specificity values of the Coulter analyzer in predicting positive heterophile status for the blast flag were 41% and 97.1%, respectively; for the variant lymphocyte flags, 72.4% and 79.1%, respectively; and for both flags, 40% and 98.1%, respectively. For the Sysmex analyzer, the sensitivity and specificity values in predicting positive heterophile status for the blast flag were 43.4% and 88.6%, respectively; for the variant lymphocyte flag, 15.8% and 90.8%, respectively; and for both flags, 10.5% and 96%, respectively. Considering the classic criteria developed by Hoagland, a lymphocytosis of at least 50% was present in 120 (66.3%) heterophile-positive patients, while an atypical lymphocytosis of at least 10% of the total WBC count was noted in 135 patients (74.6%). The sensitivity and specificity values of a lymphocytosis > or =50% for diagnosing heterophile-positive status were 66.3% and 84.5%, respectively, while the sensitivity and specificity of an atypical lymphocytosis > or =10% were 74.6% and 92.3%, respectively. The presence of smudge cells or cloverleaf lymphocyte nuclei was verified as having high specificity but low sensitivity for suggesting a diagnosis of infectious mononucleosis.

CONCLUSION

Although a number of patients did not meet Hoagland's criteria for the diagnosis of infectious mononucleosis, the flagging systems of modern hematology analyzers successfully identified most cases as requiring further review.

Protein kinase C-alpha is essential for Ramos-BL B cell survival

The Ramos-Burkitt lymphoma (BL) B cell line is driven into growth arrest and apoptosis by cross-linking surface immunoglobulin. We demonstrate that protein kinase C (PKC) activity is required for Ramos B cell proliferation and survival. A variety of PKC inhibitors trigger a significant decrease in [(3)H]thymidine incorporation with a concomitant increase in cell death. Antisense depletion of expression of the PKC-alpha isoform is sufficient to trigger cell death in the absence of any other signal, demonstrating a requirement for this isoform for survival of Ramos-BL B cells. Cross-linking surface immunoglobulin also leads to depletion of PKC-alpha levels, suggesting that this may be one mechanism by which this signals for cell death in Ramos-BL B cells.

Intensive versus standard case management for severe psychotic illness: a randomised trial. UK 700 Group

BACKGROUND

Case management has increasingly been the recommended approach to care for severely mentally ill patients since the number of psychiatric beds has decreased. Despite equivocal results, in the UK and Europe, this approach is becoming accepted policy. We assessed the effect of smaller case loads.

METHODS

We randomly assigned 708 psychotic patients in four centres standard case management (355 patients, case load 30-35 per case manager) or intensive case management (353 patients, case load 10-15 per case manager). We measured clinical symptoms and social functioning at baseline, 1 year, and 2 years. The impact of treatment on hospital use was assessed at 2 years by subgroup analyses for Afro-Caribbean and for severely socially disabled patients. Analysis was by intention to treat.

FINDINGS

There was no significant decline in overall hospital use among intensive-case-management patients (mean 73.5 vs 73.1 days in those who received standard care [SD 0.4, 95% CI -17.4 to 18.1]), nor were there any significant gains in clinical or social functioning. There was no evidence of differential effect in Afro-Caribbean patients or the most socially disabled patients.

INTERPRETATION

In well-coordinated mental-health services, a decline in case load alone does not improve outcome for these patients. Mental-health planners may need to pay more attention to the content of treatment rather than changes in service organisation.

How does managed care manage the frail elderly? The case of hospital readmissions in fee-for-service versus HMO systems

OBJECTIVES

This study examined whether hospital readmissions varied among the frail elderly in managed care versus fee-for-service (FFS) systems.

SETTING AND PARTICIPANTS

Random sample of 450 patients, aged 65 and over, from a large vertically integrated health care system in San Diego, California. Participants were receiving physician-authorized home health and survived and 18-month follow-up period.

MAIN OUTCOME MEASURES

Multiple logistic regression analyses were used to conduct comparisons of readmissions and preventable readmissions by plan type. Two methods to identify preventable readmissions were developed, one based on a computerized algorithm of service use patterns, and another based on blind clinical review.

RESULTS

The odds of having a preventable hospital readmission within 90 days of an index admission were 3.51 (P = 0.06) to 5.82 (P = 0.02) times as high for Medicare HMO enrollees compared to Medicare FFS participants, depending on the method used to assess preventability. Readmission patterns were similar for Medicare HMO enrollees and FFS study participants dually enrolled in Medicare and Medicaid.

CONCLUSION

In this group of frail elderly Medicare beneficiaries, those enrolled in an HMO were more likely to have a preventable hospital readmission than those receiving care under FFS. These results suggest that policies promoting stringent approaches to utilization control (e.g., early hospital discharge, reduced levels of post-acute care, and restricted use of home health services) may be problematic for the frail elderly.

Determination of the urinary benzene metabolites S-phenylmercapturic acid and trans,trans-muconic acid by liquid chromatography-tandem mass spectrometry

To investigate how various levels of exposure affect the metabolic activation pathways of benzene in humans and to examine the relationship between urinary metabolites and other biological markers, we have developed a sensitive and specific liquid chromatographic-tandem mass spectrometric assay for simultaneous quantitation of urinary S-phenylmercapturic acid (S-PMA) and trans,trans-muconic acid (t,t-MA). The assay involves spiking urine samples with [13C6]S-PMA and [13C6]t,t-MA as internal standards and clean up of samples by solid-phase extraction with subsequent analysis by liquid chromatography coupled with electrospray-tandem mass spectrometry-selected reaction monitoring (LC-ES-MS/MS-SRM) in the negative ionization mode. The efficacy of this assay was evaluated in human urine specimens from smokers and non-smokers as the benzene-exposed and non-exposed groups. The coefficient of variation of runs on different days (n = 8) for S-PMA was 7% for the sample containing 9.4 microg S-PMA/l urine, that for t,t-MA was 10% for samples containing 0.07 mg t,t-MA/l urine. The mean levels of urinary S-PMA and t,t-MA in smokers were 1.9-fold (P = 0.02) and 2.1-fold (P = 0.03) higher than those in non-smokers. The mean urinary concentration (+/-SE) was 9.1 +/- 1.7 microg S-PMA/g creatinine [median 5.8 microg/g, ranging from not detectable (1 out of 28) to 33.4 microg/g] among smokers. In non-smokers' urine the mean concentration was 4.8 +/- 1.1 microg S-PMA/g creatinine (median 3.6 microg/g, ranging from 1.0 to 19.6 microg/g). For t,t-MA in smokers' urine the mean (+/-SE) was 0.15 +/- 0.03 mg/g creatinine (median 0.11 mg/ g, ranging from 0.005 to 0.34 mg/g); the corresponding mean value for t,t-MA concentration in non-smokers' urine was 0.07 +/- 0.02 mg/g creatinine [median 0.03 mg/g, ranging from undetectable (1 out of 18) to 0.48 mg/g]. There was a correlation between S-PMA and t,t-MA after logarithmic transformation (r = 0.41, P = 0.005, n = 46).

Randomised controlled trial of follow up care in general practice of patients with myocardial infarction and angina: final results of the Southampton heart integrated care project (SHIP). The SHIP Collaborative Group

OBJECTIVE

To assess the effectiveness of a programme to coordinate and support follow up care in general practice after a hospital diagnosis of myocardial infarction or angina.

DESIGN

Randomised controlled trial; stratified random allocation of practices to intervention and control groups.

SETTING

All 67 practices in Southampton and south west Hampshire, England.

SUBJECTS

597 adult patients (422 with myocardial infarction and 175 with a new diagnosis of angina) who were recruited during hospital admission or attendance at a chest pain clinic between April 1995 and September 1996.

INTERVENTION

Programme to coordinate preventive care led by specialist liaison nurses which sought to improve communication between hospital and general practice and to encourage general practice nurses to provide structured follow up.

MAIN OUTCOME MEASURES

Serum total cholesterol concentration, blood pressure, distance walked in 6 minutes, confirmed smoking cessation, and body mass index measured at 1 year follow up.

RESULTS

Of 559 surviving patients at 1 year, 502 (90%) were followed up. There was no significant difference between the intervention and control groups in smoking (cotinine validated quit rate 19% v 20%), lipid concentrations (serum total cholesterol 5.80 v 5.93 mmol/l), blood pressure (diastolic pressure 84 v 85 mm Hg), or fitness (distance walked in 6 minutes 443 v 433 m). Body mass index was slightly lower in the intervention group (27.4 v 28.2; P=0.08).

CONCLUSIONS

Although the programme was effective in promoting follow up in general practice, it did not improve health outcome. Simply coordinating and supporting existing NHS care is insufficient. Ischaemic heart disease is a chronic condition which requires the same systematic approach to secondary prevention applied in other chronic conditions such as diabetes mellitus.

Epidemiology, etiology, and impact of traveler's diarrhea in Jamaica

CONTEXT

Traveler's diarrhea (TD) can incapacitate travelers. Characteristics of TD could be helpful in identifying individuals who might benefit from a vaccine against TD.

OBJECTIVE

To determine epidemiology, etiology, and impact of TD in Jamaica. Design Two-armed, cross-sectional survey conducted between March 1996 and May 1997.

SETTING

Sangster International Airport and 10 hotels in Montego Bay area, Jamaica.

SUBJECTS

To investigate epidemiology and impact, 30369 short-term visitors completed a questionnaire just before boarding their homebound aircrafts. To investigate etiology, 322 patients (hotel guests) with TD provided stool samples.

MAIN OUTCOME MEASURES

Attack and incidence rates of reported diarrhea and of classically defined TD (> or =3 unformed stool samples in 24 hours and > or =1 accompanying symptom), incapacity, risk factors, and etiology.

RESULTS

The attack rate for diarrhea was 23.6% overall, with 11.7% having classically defined TD. For a mean duration of stay of 4 to 7 days, the incidence rate was 20.9% (all TD) and 10.0% (classic TD). Among airport respondents, the incapacity lasted a mean of 11.6 hours. Less than 3% of all travelers avoided potentially high-risk food and beverages. The most frequently detected pathogens were enterotoxigenic Escherichia coli, Rotavirus, and Salmonella species.

CONCLUSIONS

A realistic plan for reducing TD is needed. Preventive measures such as the improvement of hygienic conditions at the destination, and/or the development of vaccines against the most frequent pathogens associated with TD may contribute toward achieving this goal.