Innate immune markers that distinguish red deer (Cervus elaphus) selected for resistant or susceptible genotypes for Johne's disease

While many factors contribute to resistance and susceptibility to infectious disease, a major component is the genotype of the host and the way in which it is expressed. Johne’s disease is a chronic inflammatory bowel disease affecting ruminants and is caused by infection with Mycobacterium avium subspecies paratuberculosis (MAP). We have previously identified red deer breeds (Cervus elaphus) that are resistant; have a low rate of MAP infection and do not progress to develop Johne’s disease. In contrast, susceptible breeds have a high rate of MAP infection as seen by seroconversion and progress to develop clinical Johne’s disease. The aim of this study was to determine if immunological differences exist between animals of resistant or susceptible breeds. Macrophage cultures were derived from the monocytes of deer genotypically defined as resistant or susceptible to the development of Johne’s disease. Following in vitro infection of the cells with MAP, the expression of candidate genes was assessed by quantitative PCR as well as infection rate and cell death rate. The results indicate that macrophages from susceptible animals show a significantly higher upregulation of inflammatory genes (iNOS, IL-1α, TNF-α and IL-23p19) than the macrophages from resistant animals. Cells from resistant animals had a higher rate of apoptosis at 24 hours post infection (hpi) compared to macrophages from susceptible animals. The excessive expression of inflammatory mRNA transcripts in susceptible animals could cause inefficient clearing of the mycobacterial organism and the establishment of disease. Controlled upregulation of inflammatory pathways coupled with programmed cell death in the macrophages of resistant animals may predispose the host to a protective immune response against this mycobacterial pathogen.

FBXW7 regulates glucocorticoid response in T-cell acute lymphoblastic leukaemia by targeting the glucocorticoid receptor for degradation

Loss of function mutation in FBXW7, an E3 ubiquitin ligase, is associated with good prognosis and early glucocorticoid treatment response in childhood T-cell acute lymphoblastic leukemia (T-ALL) by unknown mechanisms. Here, we show that FBXW7 targets the glucocorticoid receptor α (GRα) for ubiquitylation and proteasomal degradation in a manner dependent on glycogen synthase kinase 3 β-mediated phsophorylation. FBXW7 inactivation caused elevated GRα levels, and enhanced the transcriptional response to glucocorticoids. There was significant enhancement of GR transcriptional responses in FBXW7-deficient cell lines and primary T-ALL samples, in particular, for those pro-apoptotic regulatory proteins, BIM and PUMA. Reduced FBXW7 expression or function promoted glucocorticoid sensitivity, but not sensitivity to other chemotherapeutic agents used in T-ALL. Moreover, this was a general feature of different cancer cell types. Taken together, our work defines GRα as a novel FBXW7 substrate and demonstrates that favorable patient prognosis in T-ALL is associated with FBXW7 mutations due to enhanced GRα levels and steroid sensitivity. These findings suggest that inactivation of FBXW7, a putative tumor suppressor protein, may create a synthetic lethal state in the presence of specific anticancer therapies.

The relationship between hospital volume and mortality following mechanical ventilation in the Intensive Care Unit

BACKGROUND

A number of recent studies in North America and Europe have investigated the relationship between hospital volume and outcomes following mechanical ventilation in an Intensive Care Unit (ICU). All of these studies have revealed an association between worse outcomes and smaller-volume hospitals. This relationship has not been investigated recently in the UK.

METHODS

A retrospective cohort study was performed using data from the Birmingham and Black Country Critical Care Network database. Adult patients who received mechanical ventilation for more than 24 hours from the period from April 1, 1996, to March 31, 2006, were included in the study. The odds ratio for death in the ICU was calculated in relation to the hospital's volume of ventilation. Estimates accounted for clustering within hospitals and were adjusted for patient demographics (sex, age), APACHE II score, year of ventilation, length of ICU stay and urgency status.

RESULTS

A total of 17132 adult patient episodes were included in the analysis. The adjusted odds ratio for death in the ICU following mechanical ventilation for more than 24 hours was 1.11 (95% confidence interval: 0.91 to 1.35; P=0.297).

CONCLUSION

There is no relationship between hospital volume and mortality following mechanical ventilation in the ICU. Further larger prospective studies are needed to confirm this apparent lack of a relationship between hospital volume and mortality following mechanical ventilation in ICUs in a network of hospitals in the UK.

Surveillance for MDR-TB: is there an obligation to ensure treatment for individuals identified with MDR-TB?

This article raises ethical issues that result if individuals, during the course of research to measure the prevalence of drug-resistant tuberculosis, are identified with the disease but are not provided with or referred for appropriate treatment. It draws attention to and applauds recently published World Health Organization guidelines on the subject. Questions posed are: 1) Should treatment be provided for individuals identified through surveillance projects for MDR-TB, whatever their purpose (specific research or 'routine' national prevalence studies)? 2) If treatment availability is a problem, who is responsible for assuring this?

Peripheral blood mononuclear cell population changes associated with age and Mycobacterium avium subspecies paratuberculosis infection in red deer (Cervus elaphus)

In this study we aimed to document the maturation of the immune system in red deer and investigate the hypothesis that an immature immune system may predispose young red deer (Cervus elaphus) to an increased susceptibility to Johne's disease. Peripheral blood mononuclear cell populations were analysed using flow cytometry techniques to monitor changes associated with age and severity of infection with Mycobacterium avium subspecies paratuberculosis in red deer. The percentage of cells expressing cell population markers CD4, CD8, WC1, gammadelta TCR, CD14 and B-B4 as well as the cell activation markers CD25, CD44, ACT1 and ACT31 were analysed in relation to age and M. avium subsp. paratuberculosis infection status and disease severity. Significant changes in both cell surface markers and cell activation markers were observed as animals matured irrespective of their response to infection. The levels of CD4 and CD8 increased with age and the levels of B-B4, WC1, CD14 and gammadelta TCR decreased similar to previous studies in cattle. No differences were observed in cell surface markers or cell activation markers in relation to M. avium subsp. paratuberculosis infection status and disease severity. This research demonstrates that peripheral blood cell populations change with age in red deer and suggests that studies of cell surface markers and activation markers in peripheral blood samples do not provide information on the age-related susceptibility to Johne's disease.

'The average Scottish man has a cigarette hanging out of his mouth, lying there with a portion of chips': prospects for change in Scottish men's constructions of masculinity and their health-related beliefs and behaviours

Men's apparent resistance to recommended health practices and their engagement with 'high-risk' behaviours has been associated with an increased risk of morbidity or mortality. Recent work has highlighted the need to think critically about the health-promoting behaviours that men appear reluctant to engage in, as well as examining those they embrace, and explore the gendered meanings that men attribute to their beliefs and behaviours. This article presents men's discussions of the 'practices of masculinity' and examines their relation to, and implications for, men's health-related behaviours as articulated in 15 focus group discussions (59 participants in total). The data capture both the experiences of men who felt pressured to engage in behaviours that may be harmful to their health in order to appear masculine and the accounts of those who regarded themselves as freer to embrace salutogenic health practices. Less is known about the circumstances that might encourage men to re-think their engagement in performances of masculinity that have potentially detrimental effects on their health. The data presented here suggest that ageing, illness, and fatherhood were some of the experiences that prompted men to re-evaluate their health practices.

In vitro dissolution studies of uranium bearing material in simulated lung fluid

Inhaled uranium (U) bearing material will partially dissolve in the fluid lining of the lung, followed by a combination of retention, re-distribution, and excretion of the U. The rate of dissolution influences the retention time at the site of deposition, and the extent to which the material is available for re-distribution to other tissues. The consequential radiation dose is dependent upon the material distribution in the body and the exposure time to various tissues. The International Commission on Radiological Protection, ICRP 66 [International Commission on Radiological Protection (ICRP), 1994. Human Respiratory Tract Model for Radiological Protection. ICRP Publication 66] recommends the use of experimentally determined solubility coefficients in dose modelling. Material specific absorption parameters allow for better dose estimation than using ICRP default values for F (fast), M (moderate) and S (slow) classifications of U compounds. In vitro dissolution tests were carried out on U material collected from two U mines located in Australia. A static technique was designed in which particle samples were sandwiched between two 0.1-mum pore size membrane filters. The filter sandwich was exposed to a solvent (simulated lung fluid) for selected time intervals, at controlled test conditions for temperature and pH. The collected solution was analysed for U concentration using ICP-MS. The resulting dissolution curves were fitted with a double or triple exponential equation to determine the dissolution coefficients.

Advanced glycation of apolipoprotein A-I impairs its anti-atherogenic properties

AIMS/HYPOTHESIS

AGE contribute to the pathogenesis of diabetic complications, including dyslipidaemia and atherosclerosis. However, the precise mechanisms remain to be established. In the present study, we examined whether AGE modification of apolipoprotein A-I (apoA-I) affects its functionality, thus altering its cardioprotective profile.

MATERIALS AND METHODS

The ability of AGE-modified apoA-I to facilitate cholesterol and phospholipid efflux, stabilise ATP-binding cassette transporter A1 (ABCA1) and inhibit expression of adhesion molecules in human macrophages and monocytes was studied.

RESULTS

The ability of AGE-modified apoA-I to promote cholesterol efflux from THP-1 macrophages, isolated human monocytes and from ABCA1-transfected HeLa cells was significantly reduced (>70%) compared with unmodified apoA-I. This effect was reversed by preventing AGE formation with aminoguanidine or reversing AGE modification using the cross-link breaker alagebrium chloride. AGE-modification of HDL also reduced its capacity to promote cholesterol efflux. AGE-apoA-I was also less effective than apoA-I in stabilising ABCA1 in THP-1 cells as well as in inhibiting expression of CD11b in human monocytes.

CONCLUSIONS/INTERPRETATION

AGE modification of apoA-I considerably impairs its cardioprotective, antiatherogenic properties, including the ability to promote cholesterol efflux, stabilise ABCA1 and inhibit the expression of adhesion molecules. These findings provide a rationale for targeting AGE in the management of diabetic dyslipidaemia.

Effect of a clinical stroke on the risk of dementia in a prospective cohort

OBJECTIVE

To examine the risk and determinants of dementia following a clinically overt stroke in a prospectively followed cohort of elderly subjects.

METHODS

We examined the effect of a clinically detectable stroke on the risk of dementia using prospective data from 335 subjects in the Baltimore Longitudinal Study of Aging, all of whom were cognitively and neurologically normal at entry into the study (mean age at entry 75.1 +/- 4.2 years).

RESULTS

Clinically overt strokes are common in our cohort (cumulative risk by age 90, 15.4%; 95% CI: 10 to 22%) and confer an increased risk of dementia compared to subjects without stroke (odds ratio [OR] 5.55; 95% CI: 2.76 to 11.4). The majority of patients who became demented after a stroke had evidence of mild cognitive impairment preceding the stroke (14 of 19). Moreover, a clinically symptomatic stroke was a major risk factor for the conversion of mild cognitive impairment to dementia (OR 12.4; 95% CI: 1.5 to 99). When cognitive impairment did not precede the stroke, there was no increase in the risk of subsequent dementia. Pathologic data indicate that both vascular and Alzheimer pathology leads to the prestroke impairment.

CONCLUSION

Dementia after stroke may be determined by cognitive impairments that exist prior to the stroke.

Predictors of outcome after temporal lobectomy for the treatment of intractable epilepsy

To assess short- and long-term seizure freedom, the authors reviewed 371 patients who underwent anterior temporal lobectomy to treat pharmacoresistant epilepsy. The mean follow-up duration was 5.5 years (range 1 to 14.1 years). Fifty-three percent of patients were seizure free at 10 years. The authors identified multiple predictors of recurrence. Results of EEG performed 6 months postoperatively correlated with occurrence and severity of seizure recurrence, in addition to breakthrough seizures with discontinuation of antiepileptic drugs.

Predictors of outcome after temporal lobectomy for the treatment of intractable epilepsy

To assess short- and long-term seizure freedom, the authors reviewed 371 patients who underwent anterior temporal lobectomy to treat pharmacoresistant epilepsy. The mean follow-up duration was 5.5 years (range 1 to 14.1 years). Fifty-three percent of patients were seizure free at 10 years. The authors identified multiple predictors of recurrence. Results of EEG performed 6 months postoperatively correlated with occurrence and severity of seizure recurrence, in addition to breakthrough seizures with discontinuation of antiepileptic drugs.

Immunological and molecular characterization of susceptibility in relationship to bacterial strain differences in Mycobacterium avium subsp. paratuberculosis infection in the red deer (Cervus elaphus)

Johne's disease (JD) infection, caused by Mycobacterium avium subsp. paratuberculosis, represents a major disease problem in farmed ruminants. Although JD has been well characterized in cattle and sheep, little is known of the infection dynamics or immunological response in deer. In this study, typing of M. avium subsp. paratuberculosis isolates from intestinal lymphatic tissues from 74 JD-infected animals showed that clinical isolates of M. avium subsp. paratuberculosis from New Zealand farmed red deer were exclusively of the bovine strain genotype. The susceptibility of deer to M. avium subsp. paratuberculosis was further investigated by experimental oral-route infection studies using defined isolates of virulent bovine and ovine M. avium subsp. paratuberculosis strains. Oral inoculation with high (10(9) CFU/animal) or medium (10(7) CFU/animal) doses of the bovine strain of M. avium subsp. paratuberculosis established 100% infection rates, compared to 69% infection following inoculation with a medium dose of the ovine strain. The high susceptibility of deer to the bovine strain of M. avium subsp. paratuberculosis was confirmed by a 50% infection rate following experimental inoculation with a low dose of bacteria (10(3) CFU/animal). This study is the first to report experimental M. avium subsp. paratuberculosis infection in red deer, and it outlines the strong infectivity of bovine-strain M. avium subsp. paratuberculosis isolates for cervines.

Evaluation of co-morbidity indices in patients admitted for Chronic Obstructive Pulmonary Disease

Background. There is limited and conflicting information on the use of co-morbidity instruments to predict mortality in patients with chronic obstructive pulmonary disease (COPD). Methods. We sought to test the validity of the Charlson Index and another co-morbidity instrument, the Adult co-morbidity evaluation 27 (ACE-27), in patients admitted with COPD exacerbations. Co-morbidity scores were obtained by chart review. Information on mortality was retrieved from the Social Security Death Index. We examined the predictive validity of the Charlson and the ACE- 27 using survival analysis. Results. There were 112 patients eligible for the study. The ACE-27 but not the Charlson predicted survival, after adjusting for age, gender, and smoking history in Cox regression, hazard ratio (95% CI) of 1.99 (1.17-3.39). Conclusions. This study confirms earlier findings that the Charlson Index is not a reliable predictor of mortality in patients with COPD. However, the ACE-27 appears to be useful for predicting survival in this study.