Prevalence of asthma and allergic disorders in regional,rural, and indigenous children aged 6–8 years in Tasmania

Objective: Asthma and allergic diseases are poorly described in rural areas. The objective of this study was, therefore, to determine the prevalence of wheezing, asthma, and other allergic disorders among children living in regional and rural Tasmania. Methodology: Data from a cross-sectional survey using standardized questionnaires of asthma, allergic conditions and food allergies were collected from 39 primary schools across North West Tasmania. We enrolled 1075 children between 6 and 8?years. The main outcomes were prevalences of wheezing, asthma, and other allergic disorders further stratified by sex and indigenous status. Results: Baseline characteristics were as follows: median age 8.1?years (IQR: 7.6, 8.7) with equal sex distribution, most (80.1%) attended public schools and 11.0% identified as indigenous. We report prevalences of current wheezing (22.7%), allergic rhinoconjunctivitis (16.3%) and atopic eczema (16.6%), with higher prevalences among boys (except eczema). Food allergies were reported in 8.6% and food-related anaphylaxis in 1.6% of the sample. Indigenous children had significantly higher prevalence of current wheezing (indigenous 31.1% versus non-indigenous 21.6%; p?=?0.02). Further, children with current wheezing and no asthma diagnosis, had similar prevalence of other atopic diseases (hayfever 31.4%, eczema 44.0%, and food reaction 23.2%) compared with diagnosed asthmatics, although likely shared the illness. Conclusions: Childhood asthma is more prevalent in regional Tasmania compared with national estimates, especially among indigenous children. This appears not to be driven by an allergic response. Also, a significant proportion of children are likely to have undiagnosed asthma which has implications for rural health service delivery.     

Foreign Surgeons at Work

Delayed hypersensitivity reactions are associated with the interaction of antigen with cells rather than with serum antibody. Various concepts of delayed hypersensitivity have been developed, largely from animal experiments. This paper explores some of these concepts and suggests some of the implications of further work in this field.     

An approach to meeting the needs of medical students with learning disabilities

The Cognitive Skills Program at the Albert Einstein College of Medicine has identified 1% to 2% of students from several classes whose learning disabilities were previously undiagnosed. In three case studies, the importance of early identification and support during the preclinical years—and the impact of diagnosis, evaluation, and intervention—are illustrated. In each case, there was a dramatic improvement in performance when the student was made aware of his or her learning disability and when appropriate intervention was provided.     

Detection and viability of tumor cells in peripheral blood stem cell collections from breast cancer patients using immunocytochemical and clonogenic assay techniques [see comments]

Although peripheral blood stem cell collections (PBSC) are thought to have less tumor involvement than bone marrow (BM), the incidence of circulating tumor cells in patients with breast cancer has not been widely investigated. We prospectively investigated the incidence and viability of tumor cell involvement in PBSC and BM collections from breast cancer patients undergoing high-dose chemotherapy/hematopoietic stem cell transplantation. Paired samples of PBSC and BM from 48 patients were analyzed using an immunocytochemical technique that detects one epithelial-derived tumor cell per 5 x 10(5) mononuclear cells. Immunostained tumor cells were detected in 9.8% (13/133) PBSC specimens from 9/48 (18.7%) patients and in 62.3% (38/61) BM specimens from 32/48 (66.7%) patients, a significantly higher rate than in PBSC (P < .005). The geometric mean concentration of tumor cells in contaminated PBSC specimens was 0.8/10(5) mononuclear cells (range 0.33 to 2.0/10(5)) compared with 22.9/10(5) mononuclear cells in BM (range 1 to 3,000/10(5), P < .0001). In culture experiments, clonogenic tumor colonies grew in 21/26 immunocytochemically positive specimens. No tumor colony growth was detected in 30/32 immunocytochemically negative specimens. Immunocytochemical detection of tumor involvement in BM and PBSC correlated significantly with in vitro clonogenic growth (P < .0001). We conclude that PBSC contain fewer tumor cells than paired BM specimens from patients with advanced breast cancer and that these tumor cells appear to be capable of clonogenic growth in vitro.     

Interleukin-1-induced leukocyte extravasation across rat mesenteric microvessels is mediated by platelet-activating factor

Although our understanding of the molecular interactions that mediate the adhesion of leukocytes to venular endothelial cells has greatly expanded, very little is known about the mechanisms that mediate the passage of leukocytes across the vessel wall in vivo. The aim of the present study was to investigate the role of endogenously formed platelet-activating factor (PAF) in the process of leukocyte extravasation induced by interleukin-1 (IL-1). To determine at which stage of emigration PAF was involved, we studied the behavior of leukocytes within rat mesenteric microvessels by intravital microscopy. Rats were injected intraperitoneally with saline, recombinant rat IL-1 beta (IL-1 beta), or the peptide N-formyl-methionyl-leucyl- phenylalanine (FMLP) 4 hours before the exteriorization of the mesenteric tissue. In animals treated with IL-1 beta there was a significant increase in the number of rolling and adherent leukocytes within venules (20- to 40-micron diameter) and in the number of extravasated leukocytes in the tissue. Pretreatment of rats with the PAF receptor antagonist UK-74,505 had no effect on the leukocyte responses of rolling and adhesion, but significantly inhibited the migration of the leukocytes across the vessel wall induced by IL-1 beta (76% inhibition). A structurally unrelated PAF antagonist, WEB-2170, produced the same effect (64% inhibition). However, in contrast, UK- 74,505 had no effect on the leukocyte extravasation induced by FMLP, indicating selectivity for the response elicited by certain mediators. These results provide the first line of direct evidence for the involvement of endogenously formed PAF in the process of leukocyte extravasation induced by IL-1 in vivo.     

Contamination and Crossinfection with Clostridium difficile in an Intensive Care Unit*

Abstract: Contamination and crossinfection with Clostridium difficile in an intensive care unit. B.A.J. Walters, R. Stafford, R. K. Roberts and E. Seneviratne, Aust. N.Z. J. Med., 1982, 12, pp. 255–258. An outbreak of pseudomembranous colitis in an intensive care unit is described. This resulted in environmental contamination by Clostridium difficile. The outbreak could be traced to one patient who received several antibiotics over the preceding three months. A search was conducted for asymptomatic carriers among patient and staff but none were found. Aquisition of C. difficile from inanimate environmental sources was the most probable means of transmission of the organism. Its persistence in the hospital environment for several weeks, most likely as spores, suggests that patients who develop pseudomembranous colitis should be isolated, especially in areas of high antibiotic usage.     

Combination therapy with oral ursodeoxycholic and chenodeoxycholic acids: pretreatment computed tomography of the gall bladder improves gall stone dissolution efficacy.

In a five year study, 55 patients with radiolucent gall stones were treated with the combination of 7.5 mg chenodeoxycholic acid (CDCA) and 5.0 mg ursodeoxycholic acid (UDCA)/kg/day--that is, half the monotherapeutic doses. Side effects were few but four patients could not tolerate the prescribed bile acids because of diarrhoea or nausea. Analysis of fasting duodenal bile confirmed that CDCA+UDCA converted supersaturated into unsaturated bile but the saturation indices did not predict the dissolution response. By actuarial analysis, the confirmed (by ultrasound x2) complete gall stone dissolution rates in all 55 patients were mean (SEM) 29 (7)% at 12 and 44 (8)% at 24 months. The advent of routine computed tomography before treatment enabled comparison of dissolution efficacy in those screened by computed tomography (n = 24), whose maximum gall stone attenuation was less than 100 Hounsfield units, with that in those not screened (n = 29). Although stone size and number were comparable, patients screened by computed tomography had significantly better dissolution rates (p less than 0.025) than those not screened in this way. At 12 months, partial or complete gall stone dissolution rates were 93 (7)% in the screened and 55 (11)% in the non-screened patients. At 18 months, complete dissolution rates were 64 (12%) and 20 (9)% respectively. Computed tomography before treatment is cost effective in selecting those patients likely to achieve gall stone dissolution on treatment with UDCA+CDCA.     

The Role of Serotonin (5-HT) in Behavioral Control: Findings from Animal Research and Clinical Implications

The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research.