Asthma inhalers and subsurface enamel demineralisation: an in situ pilot study.

AIM: The purpose of this pilot study was to identify the subsurface enamel demineralising potential of two possible acidogenic lactose-based powders and their corresponding generic pump inhalers. METHODS: Ten healthy non-asthmatic adults participated in a 5- leg randomised crossover study including a 10% sucrose control. A twice-daily 400 microg dose of inhaler was applied in vitro to a demineralised enamel slab on the buccal flange of a mandibular removable appliance before in situ placement for 14 days each. Lesion parameters were determined using transverse microradiography and digitised image analysis. RESULTS: Minimal demineralisation occurred with sucrose, both pump and one powder inhaler. The remaining powder was associated with remineralisation (p = 0.29). Overall, mean lesion depth increased (p = 0.12). CONCLUSION: Asthma inhalers failed to demonstrate a significant acidogenic/cariogenic effect.     

The Stafford outbreak of Legionnaires' disease

A large outbreak of Legionnaires' disease was associated with Stafford District General Hospital. A total of 68 confirmed cases was treated in hospital and 22 of these patients died. A further 35 patients, 14 of whom were treated at home, were suspected cases of Legionnaires' disease. All these patients had visited the hospital during April 1985. Epidemiological investigations demonstrated that there had been a high risk of acquiring the disease in the out patient department (OPD), but no risk in other parts of the hospital. The epidemic strain of Legionella pneumophila, serogroup 1, subgroup Pontiac 1a was isolated from the cooling water system of one of the air conditioning plants. This plant served several departments of the hospital including the OPD. The water in the cooling tower and a chiller unit which cooled the air entering the OPD were contaminated with legionellae. Bacteriological and engineering investigations showed how the chiller unit could have been contaminated and how an aerosol containing legionellae could have been generated in the U-trap below the chiller unit. These results, together with the epidemiological evidence, suggest that the chiller unit was most likely to have been the major source of the outbreak. Nearly one third of hospital staff had legionella antibodies. These staff were likely to have worked in areas of the hospital ventilated by the contaminated air conditioning plant, but not necessarily the OPD. There was evidence that a small proportion of these staff had a mild legionellosis and that these 'influenza-like' illnesses had been spread over a 5-month period. A possible explanation of this finding is that small amounts of aerosol from cooling tower sources could have entered the air-intake and been distributed throughout the areas of the hospital served by this ventilation system. Legionellae, subsequently found to be of the epidemic strain, had been found in the cooling tower pond in November 1984 and thus it is possible that staff were exposed to low doses of contaminated aerosol over several months. Control measures are described, but it was later apparent that the outbreak had ended before these interventions were introduced. The investigations revealed faults in the design of the ventilation system.     

The effect of RANTES chemokine genetic variants on early HIV-1 plasma RNA among African American injection drug users

HIV-1 plasma RNA is a prognostic indicator of HIV-1, and increased levels of HIV-1 plasma RNA are associated with rapid progression to AIDS. Because chemokines and chemokine receptors are involved in the binding and entry of HIV-1, possible effects of host genetics on viral RNA levels should be visible in early infection. HIV-1 plasma RNA was measured within 2 years of seroconversion in 198 seroincident injection drug users followed in the AIDS Link to Intravenous Experience cohort. Genetic variants were identified in the chemokine receptors (CCR2, CCR5, and CCR5 promoter) and the chemokine RANTES using TaqMan and restriction fragment length polymorphism assays. Linear regression of RANTES haplotypes on early HIV-1 plasma RNA identified individuals homozygous for the RANTES R1 haplotype as having a lower viral load by almost one-half log10 unit compared with those bearing non-RANTES R1 haplotypes (-0.43, 95% confidence interval: -0.74, -0.12). Genetic variants in RANTES may downregulate RANTES gene expression and increase early HIV-1 plasma RNA. Because RANTES is a critical chemokine and competitively inhibits HIV-1 by binding to its receptor CCR5, treatment to enhance RANTES expression may assist in delaying the progression of AIDS by decreasing the initial viral load.     

Examination of the Factor Structure and Correlates of the Perceived Military Healthcare Stressors Scale

The current study evaluated the factor structure, reliability estimates, correlates, and predictive utility of the Perceived Military Healthcare Stressor Scale (PMHSS) in a sample of active duty military medical personnel (N = 1,131) deployed to Joint Base Balad in Iraq. The sample was composed of an approximately even split of male (51.2%) and female (48.8%) participants who ranged in age from 18 to 60 years. The PMHSS is a 21‐item measure that was designed to assess the impact of specific medical stressors that military healthcare providers may encounter while deployed. An exploratory factor analysis of the PMHSS revealed the presence of two distinct factors: trainable and futility stressors. Confirmatory factor analysis showed that a bifactor model best represented the data, with all items loading higher on the general factor relative to their specific subscale factors. Evidence of partial scalar invariance by gender was found. The PMHSS was significantly correlated with several convergent measures, including assessments of posttraumatic stress disorder (PTSD), depression severity, distress due to both combat exposure and general deployment‐related concerns, and positive affect, rs = .30–.59. PMHSS scores were more strongly correlated with PTSD and depression in women than in men, and they provided incremental validity in predicting convergent measures over and above other related constructs. Healthcare–specific stressors are an understudied area, and this study provides new insights into how deployment‐related caregiving stress may impact deployed military medical personnel independently of the impact of combat experiences.     

An epidemiological study on patients undergoing dacryocystorhinostomy

Dacryocystorhinostomy is performed in patients with naso-lacrimal duct obstruction to bypass the site of obstruction so as to relieve the patient of the irritating and socially embarrassing symptoms of epiphora. We discuss the various epidemiological aspects especially the vast difference by which the females out-number the males in patients undergoing DCR and the likely explanations for this difference in our study on 74 patients which underwent DCR in our institute.