Lung function,asthma symptoms,and quality of life for children in public housing in Boston: a case-series analysis

Background  

Children in urban public housing are at high risk for asthma, given elevated environmental and social exposures and suboptimal medical care. For a multifactorial disease like asthma, design of intervention studies can be influenced by the relative prevalence of key risk factors. To better understand risk factors for asthma morbidity in the context of an environmental intervention study, we conducted a detailed baseline evaluation of 78 children (aged 4–17 years) from three public housing developments in Boston.     

Manganese induced immune suppression of the lobster, Nephrops norvegicus

Manganese (Mn) is one of the most abundant elements on earth, particularly in the soft bottom sediments of the oceans. As a micronutrient Mn is essential in the metabolic processes of organisms. However, at high concentrations the metal becomes a neurotoxin with well-documented effects. As a consequence of euthrophication, manganese is released from bottom sediments of coastal areas and the Norway lobsters, Nephrops norvegicus, can experience high levels of bioavailable Mn(2+). Here, we present the first report showing that Mn also affects several fundamental processes in the mobilisation and activation of immunoactive haemocytes. When N. norvegicus was exposed to a realistic [Mn(2+)] of 20 mg l(-1) for 10 days 24.1 microg ml(-1) was recorded in the haemolymph. At this concentration the total haemocyte count was reduced by ca. 60%. By using BrdU as a tracer for cell division, it was shown that the proliferation rate in the haematopoietic tissue did not increase, despite the haemocytepenia. A gene coding for a Runt-domain protein, known to be involved in maturation of immune active haemocytes in a variety of organisms, was identified also in haemocytes of N. norvegicus. The expression of this gene was >40% lower in the Mn-exposed lobsters as judged by using a cDNA probe and the in situ hybridisation technique. In response to non-self molecules, like lipopolysaccharide (LPS), the granular haemocytes of arthropods are known to degranulate and thereby release and activate the prophenoloxidase system, necessary for their immune defence. A degranulation assay, tested on isolated granular haemocytes, showed about 75% lower activity in the Mn-exposed lobsters than that for the unexposed. Furthermore, using an enzymatic assay, the activation per se of prophenoloxidase by LPS was found blocked in the Mn-exposed lobsters. Taken together, these results show that Mn exposure suppressed fundamental immune mechanisms of Norway lobsters. This identifies a potential harm that also exists for other organisms and should be considered when increasing the distribution of bioavailable Mn, as has been done through recently introduced applications of the metal.     

Long-Term Stability at ?20°C of Aspergillus Galactomannan in Serum and Bronchoalveolar Lavage Specimens

Research to develop and validate novel methods for diagnosis of aspergillosis based on detection of galactomannan requires the use of clinical specimens that have been stored frozen. Data indicating that galactomannan remains stable when frozen are scant. The objective of this study was to determine the stability of galactomannan in clinical specimens stored at −20°C that were positive in the Platelia Aspergillus enzyme immunoassay when initially tested. Prospective real-time testing of serum and bronchoalveolar lavage (BAL) fluid pools from positive and negative patient specimens showed no decline in galactomannan index (GMI) over 11 months at −20°C and no development of positive reactions in the negative-control pool. Retrospective testing of positive specimens that had been stored at −20°C for 5 years showed that 28 of 30 serum (n = 15) or BAL (n = 15) specimens remained positive. These findings support the use of frozen serum or BAL specimens stored for at least 5 years in evaluation of diagnostic tests based on detection of galactomannan.     

Inhalation toxicity of brevetoxin 3 in rats exposed for 5 days

Brevetoxins are potent neurotoxins produced by the marine dinoflagellate Karenia brevis. Exposure to brevetoxins may occur during a K. brevis red tide when the compounds become aerosolized by wind and surf. This study assesses possible adverse health effects associated with short-term inhalation exposure to brevetoxin 3. Male F344/Crl/Br rats were exposed to 500 microg brevetoxin 3/m3 by nose-only inhalation for 0.5 or 2 h/d for 5 consecutive days. Control rats were sham exposed for 2 h to vehicle. Calculated deposited brevetoxin doses were 8.3 and 33 microg/kg/d for the low- and high-dose groups, respectively. At the termination of exposures, only body weights of the high-dose group (Group B) were significantly below control values. By immunohistochemistry (IHC), small numbers of splenic and peribronchiolar lymphoid tissue macrophages stained positive for brevetoxin, while nasal mucosa, liver, and brain were IHC negative for brevetoxin. No gross or microscopic lesions were observed in any tissue examined. There was no biochemical evidence of cytotoxicity or inflammation in bronchoalveolar lavage fluid. Alveolar macrophages showed some evidence of activation following brevetoxin exposure. Humoral-mediated immunity was suppressed in brevetoxin-exposed rats as indicated by a >70% reduction in splenic plaque-forming cells in brevetoxin-exposed animals compared to controls. Results suggest that the immune system may be a target of toxicity following brevetoxin inhalation. Future studies will focus on identification of a no-effect level and mechanisms underlying brevetoxin-induced immune suppression.