Nonredundant Dimethyl Sulfoxide Reductases Influence Salmonella enterica Serotype Typhimurium Anaerobic Growth and Virulence.

Facultative anaerobic enteric pathogens can utilize a diverse array of alternate electron acceptors to support anaerobic metabolism and thrive in the hypoxic conditions within the mammalian gut. Dimethyl sulfoxide (DMSO) is produced by methionine catabolism and can act as an alternate electron acceptor to support anaerobic respiration. The DMSO reductase complex consists of three subunits, DmsA, DmsB, and DmsC, and allows bacteria to grow anaerobically with DMSO as an electron acceptor. The genomes of nontyphoidal Salmonella enterica encode three putative dmsABC operons, but the impact of the apparent genetic redundancy in DMSO reduction on the fitness of nontyphoidal S. enterica during infection remains unknown. We hypothesized that DMSO reduction would be needed for S. enterica serotype Typhimurium to colonize the mammalian gut. We demonstrate that an S. Typhimurium mutant with loss of function in all three putative DMSO reductases (ΔdmsA3) poorly colonizes the mammalian intestine when the microbiota is intact and when inflammation is absent. DMSO reduction enhances anaerobic growth through nonredundant contributions of two of the DMSO reductases. Furthermore, DMSO reduction influences virulence by increasing expression of the type 3 secretion system 2 and reducing expression of the type 3 secretion system 1. Collectively, our data demonstrate that the DMSO reductases of S. Typhimurium are functionally nonredundant and suggest DMSO is a physiologically relevant electron acceptor that supports S. enterica fitness in the gut.

Guidelines for the management of postoperative soiling in children with Hirschsprung disease.

Although most children with Hirschsprung disease ultimately achieve functional and comfortable stooling, some will experience a variety of problems after pull-through surgery. The most common problems include soiling, obstructive symptoms, enterocolitis, and failure to thrive. The purpose of this guideline is to present a rational approach to the management of postoperative soiling in children with Hirschsprung disease. The American Pediatric Surgical Association Hirschsprung Disease Interest Group engaged in a literature review and group discussions. Expert consensus was then used to summarize the current state of knowledge regarding causes, methods of diagnosis, and treatment approaches to children with soiling symptoms following pull-through for Hirschsprung disease. Causes of soiling after pull-through are broadly categorized as abnormalities in sensation, abnormalities in sphincter control, and "pseudo-incontinence." A stepwise algorithm for the diagnosis and management of soiling after a pull-through for Hirschsprung disease is presented; it is our hope that this rational approach will facilitate treatment and optimize outcomes.

CD4 cell count at initiation of ART, long-term likelihood of achieving CD4 >750 cells/mm3 and mortality risk.

OBJECTIVES: We sought to evaluate associations between CD4 at ART initiation (AI), achieving CD4 >750 cells/mm(3) (CD4 >750), long-term immunological recovery and survival. METHODS: This was a prospective observational cohort study. We analysed data from ART-naive patients seen in 1996-2012 and followed ≥3 years after AI. We used Kaplan-Meier (KM) methods and log-rank tests to compare time to achieving CD4 >750 by CD4 at AI (CD4-AI); and Cox regression models and generalized estimating equations to identify factors associated with achieving CD4 >750 and mortality risk. RESULTS: Of 1327 patients, followed for a median of 7.9 years, >85% received ART for ≥75% of follow-up time; 64 died. KM estimates evaluating likelihood of CD4 >750 during 5 years of follow-up, stratified by CD4-AI <50, 50-199, 200-349, 350-499 and 500-750, were 20%, 25%, 56%, 80% and 87%, respectively (log-rank P < 0.001). In adjusted models, CD4-AI ≥200 (versus CD4-AI <200) was associated with achievement of CD4 >750 [adjusted HR (aHR) = 4.77]. Blacks were less likely than whites to achieve CD4 >750 (33% versus 49%, aHR = 0.77). Mortality rates decreased with increasing CD4-AI (P = 0.004 across CD4 strata for AIDS causes and P = 0.009 for non-AIDS death causes). Among decedents with CD4-AI ≥50, 56% of deaths were due to non-AIDS causes. CONCLUSIONS: Higher CD4-AI resulted in greater long-term CD4 gains, likelihood of achieving CD4 >750, longer survival and decreased mortality regardless of cause. Over 80% of persons with CD4-AI ≥350 achieved CD4 >750 by 4 years while 75% of persons with CD4-AI <200 did not. These data confirm the hazards of delayed AI and support early AI.

Treatment of hepatitis C virus (HCV) infection in patients coinfected with HIV in the HIV Outpatient Study (HOPS), 1999-2007.

Liver disease due to hepatitis C virus (HCV) infection is a leading cause of non-AIDS-related morbidity and mortality in patients infected with HIV. We assessed the frequency of and predictors for initiation of treatment for HCV infection among patients coinfected with HCV/HIV enrolled in the HIV Outpatient Study (HOPS) during 1999-2007. We included patients with confirmed HCV infection, at least 1 year of subsequent follow-up, and no evidence of prior HCV treatment. We assessed predictors of HCV treatment initiation using Cox proportional hazards analyses. During 1999-2007, 103 (20%) HOPS patients coinfected with HCV/HIV initiated HCV treatment during a median of 4.3 years of follow-up (interquartile range: 2.7, 6.7). In multivariable analysis, non-Hispanic black race/ethnicity (hazard ratio HR] 0.3; 95% confidence interval [CI] = 0.2, 0.6) was independently associated with a lower likelihood of HCV treatment. Elevated alanine aminotransferase (ALT; HR 3.5; 95% CI = 2.2, 5.6) and CD4+ cell count ≥500 cells/mm(3) (HR 1.8; 95% CI = 1.2, 2.8) at the start of observation were independently associated with higher likelihood of HCV treatment. For patients starting observation in 1999-2001, 2002-2004 and 2005-2007, 5%, 11% and 21% of patients initiated treatment during the first year of follow-up, respectively. Between 1999 and 2007, despite a stable low fraction of patients coinfected with HCV/HIV initiating treatment for HCV infection, an increasing proportion initiated treatment within the first year after the infection was confirmed. Treatment of HCV infection in patients coinfected with HCV/HIV should be considered a priority, given the increased risk of accelerated end-stage liver disease.

Antiretroviral nonadherence and condomless sex in the HIV Outpatient Study, USA, 2007-2014.

Effective antiretroviral therapy (ART) reduces plasma HIV RNA viral load (VL) to undetectable levels and its effectiveness depends on consistent adherence. Consistent adherence and use of safe sex practices may substantially decrease the risk of HIV transmission. We sought to explore the potential association between self-reported nonadherence to ART and engaging in unsafe sexual practices capable of transmitting HIV. Using clinical and audio computer-assisted self-interview data from the prospective HIV Outpatient Study from 2007 to 2014, we assessed the frequency of self-reported ART nonadherence during the three days prior to the survey among HIV-infected persons in care and factors associated with self-reported ART nonadherence. Of 1729 patients included in this analysis (median age = 48 years, 74.3% men who have sex with men), 17% were nonadherent, 15% had a detectable VL, and 42% reported condomless anal or vaginal sex in the past six months. In multivariable analysis, self-reported nonadherence was independently associated with younger age (adjusted odds ratio [aOR] 0.8 per additional ten years, [95% CI] 0.7-1.0), non-Hispanic black race/ethnicity (aOR 1.9; 95% CI 1.4-2.6 versus white), public health insurance (aOR 1.6, 95% CI 1.2-2.3 compared with private), survey date in 2011-2014 versus 2007-2010 (aOR 0.7, 95% CI 0.5-0.9), CD4 cell count ≥ 500 versus < 200 cells/mm3 (aOR 0.3, 95% CI 0.2-0.5), greater number of ART regimen doses (aOR 1.6, 95% CI 1.3-2.2), and binge drinking (aOR 1.4, 95% CI, 1.1-1.9). In this analysis, self-reported nonadherence was not associated with engaging in condomless sex.

Asialo GM1(+) CD8(+) T cells play a critical role in costimulation blockade-resistant allograft rejection.

Simultaneous blockade of the CD40 and CD28 costimulatory pathways is an effective treatment strategy to promote allograft acceptance but does not lead to indefinite allograft survival. The immune mechanisms responsible for costimulation-independent rejection are not defined. Here we have studied the rejection responses of murine C57BL/6 recipients, which we show to be relatively resistant to inhibition by combined CD40/CD28 blockade. We demonstrate that asialo GM1(+) CD8(+) cells play a critical role in this costimulation blockade-resistant rejection. These results provide new insights into the costimulatory requirements for T-cell subsets and demonstrate for the first time that combined blockade of the CD40 and CD28 pathways does not adequately inhibit CD8-mediated skin allograft rejection. Furthermore, we provide evidence that asialo GM1 is a potentially important therapeutic target for CD8-dependent immune responses.

Predictors of outpatient mental health utilization by primary care patients in a health maintenance organization.

OBJECTIVE: The authors examined the volume and predictors of outpatient mental health utilization among primary care patients in a large staff-model health maintenance organization (HMO). METHOD: Consecutive primary care patients (N = 1,810) were screened by using the 12-item General Health Questionnaire, and a stratified random sample (N = 373) completed the 28-item General Health Questionnaire and Composite International Diagnostic Interview. Telephone interviews and computerized records were used to examine use of mental health services inside and outside the HMO over the following 3 months. RESULTS: Over 3 months, 6.7% of the screened patients used mental health services within the HMO. Utilization increased with higher General Health Questionnaire score (2.9% among those scoring 0, 22.3% among those scoring 8 or more) and decreased with higher out-of-pocket cost for mental health visits (7.5% for those with no change, 3.3% for those paying $30/visit). Among the interviewed subjects, 5.1% used mental health services within the HMO (mean = 2.92 visits) and 8.9% used outside mental health services (mean = 8.86 visits). Use of outside services was more strongly related to sociodemographic factors, and use of inside services was more related to severity of psychological disorder. CONCLUSIONS: Among these subjects, use of mental health care was high and services purchased outside the HMO exceeded those inside the HMO. Increasing copayment levels progressively reduced demand without respect to severity of illness. Attempts to control outpatient mental health costs must address equity and clinical need.

The impact of broadened civil commitment standards on admissions to state mental hospitals.

In 1979, the state of Washington broadened its criteria governing the involuntary commitment of the mentally ill. This study examined the impact of the revised law on involuntary and voluntary admissions and on the type of patient admitted to state hospitals in Washington. The short-term effect of the law was an abrupt increase in involuntary commitments, with a concomitant but not offsetting decline in voluntary admissions. Although the law resulted in a substantial change in admissions policy, it does not appear to have altered the type of patient admitted to state mental hospitals in Washington.

Impact of visit copayments on outpatient mental health utilization by members of a health maintenance organization.

OBJECTIVE: The authors examined the impact of increasing cost sharing on use of outpatient mental health services. METHOD: A quasi-experimental design was used to study outpatient utilization by members of a health maintenance organization (HMO) who were subject to increasing copayments for mental health visits (state government employees and dependents). Their outpatient mental health utilization was compared with that of similar HMO members who were not subject to cost sharing (federal government employees and dependents). Analyses compared both likelihood of any service use and number of visits per year among service users. RESULTS: Institution of $20/visit copayments was associated with a 16% decrease in likelihood of service use but no change in visit rate among service users. A subsequent copayment increase to $30/visit resulted in no significant change in likelihood of use but was associated with a 9% decrease in visits per year among those using services. The impact of the first copayment change on likelihood of using services did not vary according to level of clinical need (as measured by prior service use and psychotropic drug use). CONCLUSIONS: In this staff-model HMO, modest visit copayments significantly reduced initial access to mental health treatment and had a smaller effect on treatment intensity. Copayments restricted access regardless of clinical need. Designers of mental health benefits must consider the impact of copayments on those with the greatest need for treatment.

Analysis of the CD40 and CD28 pathways on alloimmune responses by CD4+ T cells in vivo.

BACKGROUND: Blockade of the CD40 and CD28 pathways is a powerful strategy to inhibit CD4-mediated alloimmune responses. In this study, we examine the relative roles of the CD40 and CD28 pathways on CD4-mediated allograft rejection responses, and further characterize the role of these pathways on CD4+ T-cell activation, priming for cytokine production, and cell proliferation in response to alloantigen in vivo. METHODS: BALB/c skin allografts were transplanted onto C57BL/6 Rag 1-/- recipients reconstituted with CD4 cells from CD28-/- or CD40L-/- donors. The popliteal lymph node assay was used to study the role of these pathways on CD4-cell activation and priming in vivo. To investigate the role of CD40 and CD28 blockade on CD4-cell proliferation, the fluorescein dye carboxyfluorescein diacetate succinimidyl ester was used. We performed heterotopic cardiac transplantation using CD40-/- mice to evaluate the role of CD40 on donor versus recipient cells in CD4-mediated rejection. RESULTS: B6 Rag 1-/- recipients reconstituted with CD28-/- CD4+ T cells acutely rejected allografts (median survival time 15 days), whereas recipients reconstituted with CD40L-/- CD4+ T cells had significantly prolonged survival of BALB/c skin grafts (MST 71 days). CD40L blockade was equivalent to or inferior to CD28 blockade in inhibition of in vivo CD4-cell activation, priming for cytokine production, and proliferation responses to alloantigen. BALB/c recipients depleted of CD8 cells promptly rejected donor B6 CD40-/- cardiac allografts, whereas B6 CD40-/- recipients depleted of CD8 cells had significantly prolonged survival of BALB/c wild-type cardiac allografts. CONCLUSIONS: The CD40/CD40L pathway, but not the CD28/B7 pathway, is critical for CD4-mediated rejection responses, however, the responsible mechanisms remain unclear.

Interpreting excess mortality in a prevention trial for older adults.

BACKGROUND: In a randomized trial evaluating preventive services for older adults excess mortality was observed in the treatment group. We examined four explanations: unbalance of baseline characteristics, unintended effects of the intervention, consequence of an autonomy intervention (including increased number of living wills in the treatment group), and chance. We focus here on the effects of the autonomy intervention. METHODS: Preparation of living wills in the treatment and control groups was compared both at baseline and follow-up. A linear predictor of mortality was used to identify participants at high risk of dying. Charts of these 200 participants were reviewed for evidence of serious medical events and resuscitation decisions. Rates of life-sustaining treatment were compared between treatment and controls using logistic regression. RESULTS: More living wills (65%) were noted for the treatment group than control group (47%) at follow-up. Thirty-six per cent of participants were identified as having a serious medical event; of these, participants in the treatment group were over twice as likely not to receive life-sustaining treatment. CONCLUSIONS: Advance directives contributed to excess deaths, indicating the success of the autonomy intervention.

The effect of regulation of high blood pressure on plasma endothelin-1 levels in blacks with hypertension.

Plasma concentrations of immunoreactive endothelin-1 (irET-1) are significantly elevated in blacks with hypertension. In the present study, we investigated the effect of the regulation of high blood pressure on plasma irET-1 levels in black hypertensive individuals. After the initial blood samples were collected from 20 black patients with uncontrolled high blood pressure (Day 1), an intensive antihypertensive treatment was initiated, and the blood pressure and plasma irET-1 levels were monitored on days 2, 8, and 22. When the high blood pressure was brought under control with commonly used antihypertensive medications, plasma irET-1 concentrations dropped dramatically, suggesting that ET-1 concentrations rise as a consequence of high blood pressure in this study group.

Aggressive skin allograft rejection in CD28-/- mice independent of the CD40/CD40L costimulatory pathway.

CD28-/- mice have been utilized to study the role of B7/CD28 and B7-CTLA4 interactions. There is evidence that CTLA4 ligation may be critical for tolerance induction. The aim of the current study is to further investigate rejection responses of CD28-/- mice and to define the role of B7-CTLA4 interactions in the absence of the CD40 and CD28 pathways. Balb/c skin allografts were transplanted onto C57BL/6 (B6) wild type or CD28-/- mice treated with anti-CD40L, CTLA4-Ig, or combination blockade. To investigate the cellular mechanism of rejection in CD28-/- recipients, mice were treated with anti-CD4 or anti-CD8 antibodies prior to treatment with costimulation blockade. The fluoroscein dye CFSE was utilized to study T cell expansion in vivo. Surprisingly, treatment of B6 CD28-/- mice with CTLA4-Ig alone (MST 12d), anti-CD40L alone (MST 13d), or combined blockade (MST 13d) had no effect on allograft survival compared to untreated B6 CD28 mice (MST 11d). CD28-/- recipients depleted of CD4+ cells and treated with CTLA4-Ig, anti-CD40L, or combination blockade also did not have prolonged survival compared with untreated mice (MST 10d). In contrast, CD28-/- recipients depleted of CD8+ cells had markedly prolonged allograft survival when treated with either anti-CD40L alone (MST 49d) or with combination blockade (MST 57d). Studies utilizing CFSE demonstrated that CD28-/- CD8+ T cells are not defective in in vivo proliferation responses compared with wild type CD8 cells. Thus, CD28-/- CD8+ T cells are responsible for aggressive rejection responses of CD28-/- mice independent of the CD40 pathway. In addition, CD40L blockade does not result in CD4+ T cell tolerance in CD28 recipients, despite an intact B7-CTLA4 pathway.

Partnerships for research among managed care organizations.

Researchers within health maintenance organizations (HMOs) need to create greater opportunities for collaborative research within their organizations. Multisite research will yield high-quality information for improving care. This paper describes situations in which competition as well as collaboration are possible across HMOs in the current environment. The paper considers the following questions: (1) What criteria determine if a project can be conducted as a multisite study; and (2) what population and organizational features should be considered when designing cross-site collaboration? The paper also discusses two important trends in the larger health care environment: cost containment, which is both a challenge and an opportunity for health services researchers working within managed care; and mergers and acquisitions, which are changing the face of the larger health care industry.

Portal film quality: a multiple institutional study.

The variation in quality of the several thousand portal films submitted to the Quality Assurance Review Center (QARC) has been substantial. To ascertain the nature and severity of this problem, a detailed study of "whole brain" portal films which were taken at 23 different radiotherapy departments for patients entered on three national leukemia studies was performed. Each film was analyzed in two ways: (a) independent subjective evaluation by four experienced radiotherapists and (b) measurement of objective parameters. Scores from 416 evaluations together with measured parameters were stored in a data base system for easy statistical manipulation. The dependence of perceived film quality on these objective parameters has been correlated and is the subject of this report.

The Veterans Administration Northwest Regional Health Services Research and Development Field Program: organization, activities, and early outcomes.

In 1982, the Veterans Administration established Health Services Research field programs in each of the six VA regions. Herein, we describe the historical origins, organization, responsibilities, activities, and early accomplishments of one of these programs--the Northwest Regional HSR&D field program. Special reference is made to this program's commitment to health services research relevant to geriatrics and gerontology, including the development of a system-wide agenda for research, information syntheses in geriatrics-relevant health services research topics, and the conduct of funded projects pertinent to care of the elderly. The importance of a medical center location for the field programs is discussed, and early indications of institutional impact are described.

In-hospital resuscitation: association between ACLS training and survival to discharge.

CONTEXT: No data have been published on the relationship between advanced cardiac life support (ACLS) training of the individual who initiates resuscitation efforts and survival to discharge. OBJECTIVE: To determine whether patients whose arrests were discovered by nurses trained in ACLS had survival rates different from those discovered by nurses not trained in ACLS. DESIGN: Cohort case-comparison. SETTING: A 550-bed, tertiary care center in central Georgia. SUBJECTS: Patients whose cardiopulmonary arrest was discovered by a nurse who activated the in-hospital resuscitation mechanism. MAIN OUTCOME MEASURE: Patient survival to discharge. RESULTS: Initial rhythm was strongly related to survival to discharge and individually associated with 57% of the variability in survival. Nurse's training in advanced cardiac life support was also strongly related to survival and individually associated with 29% of the variability. Combining both the variables determined 62% of the variability in survival to discharge. Patients discovered by an ACLS-trained nurse (n=88) were about four times more likely to survive (33 survivors, 38%) than were patients, discovered by a nurse without training in ACLS (n=29, three survivors, 10%). CONCLUSION: Arrest discovery by nurses trained in ACLS is significantly and dramatically associated with higher survival-to-discharge rates.

Resuscitation in the hospital: relationship of year and rhythm to outcome.

OBJECTIVE: determine the frequency of initial rhythms in in-hospital resuscitation and examine its relationship to survival. Assess changes in outcome over time. METHODS: retrospective cohort (registry) including all admissions to the Medical Center of Central Georgia in which a resuscitation was attempted between 1 January, 1987 and 31 December, 1996. RESULTS: the registry includes 3327 admissions in which 3926 resuscitations were attempted. Only the first event is reported. There were 961 hospital survivors. Survival increased from 24.2% in 1987 to 33.4% in 1996 (chi(2)=39.0, df=1, P<0.0001). Survival was affected strongly by initial rhythm (chi(2)=420.0, df=1, P<0.0001) and decreased from 63.2% for supraventricular tachycardia (SVT) to 55.3% for ventricular tachycardia (VT), 51.0% for perfusing rhythms (PER), 34.8% for ventricular fibrillation (VF), 14.3% for pulseless electrical activity (PEA) and 10.0% for asystole (ASYS). PEA was the most frequent rhythm (1180 cases) followed by perfusing (963), asystole (580), VF (459), VT (94) and SVT (38). DISCUSSION: the powerful effect of initial rhythm on survival has been reported in pre-hospital and in-hospital resuscitation. VF is considered the dominant rhythm and generally accounts for the most survivors. We report good outcome for each; however, VF represents only 13.8% of events and 16.7% of survivors. PEA accounts for more survivors (169) than does VF (160). Our improved outcome is partially explained by changes in rhythms, but other institutional variables need to be identified to fully explain the results. Further studies are needed to see if our findings can be sustained or replicated.

Cost and outcomes of Medicare reimbursement for HMO preventive services.

Medicare beneficiaries enrolled in a health maintenance organization (HMO) were randomized to a preventive services benefit package for 2 years or to usual care. At 24- and 48-month follow-ups, the treatment group had completed more advance directives, participated in more exercise, and consumed less dietary fat than the control group. Unexpectedly, more deaths occurred in the treatment group. Surviving treatment-group enrollees reported higher satisfaction with health, less decline in self-rated health status, and fewer depressive symptoms than surviving control participants. Despite these changes, the intervention did not yield lower cost per quality-adjusted life year in this historically prevention-oriented HMO.

Prospects and problems in using data from HMOs for the study of aging populations and their health care needs.

Health maintenance organizations (HMOs) are providing a larger volume of health care services to older Americans than ever before. HMOs must reexamine the general practice of equating utilization of services with the health care need and collect better population-based information, including measures of health status. This article discusses the data elements that are widely available in HMO data bases as well as those that are predictably missing.