Bronchial hyperresponsiveness in women cooks and cleaners

The aim of this cross-sectional study was to assess the prevalence and characteristics of bronchial hyperresponsiveness (BHR) in 43 women cleaners (aged 26 to 57) and 37 women cooks (aged 29 to 55) and compare them with 45 controls (women office workers aged 27 to 58). The evaluation of all subjects included a questionnaire, skin prick tests to common aeroallergens, spirometry, and histamine challenge (PC20 < or = 8 mg mL(-1)). We found higher BHR prevalence in cleaners and cooks than in office workers (30.2 % and 29.7 %, vs. 17.7 %, respectively), but statistical significance was not reached. The prevalence of mild and moderate to severe BHR was similar in all groups. Borderline BHR prevalence was significantly higher in cleaners than in controls (16.2 % vs. 6.6 %, P=0.032) whereas the difference was on the verge of significance in cooks (13.5 % vs. 6.6 %, P=0.081). Moderate to severe BHR was strongly associated with positive family history of asthma and atopy in all groups. Mild BHR was significantly associated with daily smoking in cleaners (P=0.031) and cooks (P=0.021), as well as with the duration of exposure in cleaners (P=0.038). Borderline BHR was closely related to daily smoking and duration of exposure in both cleaners and cooks. Our findings indicate an important role of workplace exposure in borderline BHR development, as well as the significant effect of smoking on mild BHR development in women cleaners and cooks.     

Synthesis and properties of molecular probes for the rescue site on mutant cystic fibrosis transmembrane conductance regulator

Cystic fibrosis is a genetic disease caused by mutations in the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. In vitro experiments have demonstrated that 4-methyl-2-(5-phenyl-1H-pyrazol-3-yl)phenol (VRT-532, 1) is able to partially restore the function of mutant CFTR proteins. To help elucidate the nature of the interactions between 1 and mutant CFTR, molecular probes based on the structure of 1 have been prepared. These include a photoreactive aryl azide derivative 11 and a fluorescent dansyl sulfonamide 15. Additionally, a method for hydrogen isotope exchange on 1 has been developed, which could be used for the incorporation of radioactive tritium. Using iodide efflux assays, the probe molecules have been demonstrated to modulate the activity of mutant CFTR in the same manner as 1. These probe molecules enable a number of biochemical experiments aimed at understanding how 1 rescues the function of mutant CFTR. This understanding can in turn aid in the design and development of more efficacious compounds which may serve as therapeutic agents in the treatment of cystic fibrosis.     

Is Panton-Valentine leukocidin the major virulence determinant in community-associated methicillin-resistant Staphylococcus aureus disease?

Methicillin-resistant Staphylococcus aureus (MRSA) remains a major problem in hospitals, and it is now spreading in the community. A single toxin, Panton-Valentine leukocidin (PVL), has been linked by epidemiological studies to community-associated MRSA (CA-MRSA) disease. However, the role that PVL plays in the pathogenesis of CA-MRSA has not been tested directly. To that end, we used mouse infection models to compare the virulence of PVL-positive with that of PVL-negative CA-MRSA representing the leading disease-causing strains. Unexpectedly, strains lacking PVL were as virulent in mouse sepsis and abscess models as those containing the leukotoxin. Isogenic PVL-negative (lukS/F-PV knockout) strains of USA300 and USA400 were as lethal as wild-type strains in a sepsis model, and they caused comparable skin disease. Moreover, lysis of human neutrophils and pathogen survival after phagocytosis were similar between wild-type and mutant strains. Although the toxin may be a highly linked epidemiological marker for CA-MRSA strains, we conclude that PVL is not the major virulence determinant of CA-MRSA.     

Adverse effects in workers exposed to inorganic lead

This paper describes a retrospective cohort study comparing 60 workers occupationally exposed to inorganic lead and 60 matched controls. All subjects were assessed using data obtained from a specially designed Questionnaire for lead exposure and toxic effects assessment, physical examination, spirometry, ECG, and laboratory tests including blood lead level (BLL) and biomarkers of lead toxic effects. Muscle pain, droopiness, and work-related nasal symptoms were significantly more frequent in lead workers. The prevalence of lung symptoms was higher in lead workers than in controls, but not significantly (20 % vs. 6.6 %, respectively). Mean values of BLL and delta-aminolevulinic acid (ALA) were significantly higher in lead workers. The activity of delta-aminolevulinic acid dehydratase (ALAD) in lead workers was significantly lower than in controls. Abnormal of BLL, ALAD, and ALA were more frequent in lead workers, with statistical difference for BLL and ALAD. Inverse correlation was found between BLL and ALAD, and positive correlation between BLL and age, years of employment, and years of exposure. Inverse correlation was found between ALAD and age, years of employment, years of exposure, blood pressure, alcohol consumption, and years of alcohol consumption. Changes in spirometry correlated inversely with BLL. A positive correlation was found between BLL and erythrocyte count and haemoglobin concentration, whereas it was inverse for ALAD and haemoglobin concentration. A significant difference was found for BLL and ALAD, with a very high odds ratio (14.64 and 7.23, respectively) and high relative risk (4.18 and 3.08, respectively). Our data have confirmed the association between occupational lead exposure and deviation in specific biological markers of lead effect and between the role of occupational exposure in the development of adverse effects.     

The role of inflammation in the etiopathogenesis of occupational bronchial asthma

Numerous recent studies point out a relationship between bronchial reactivity and the inflammation of the airways. The paper deals with the most frequent mechanisms of bronchoconstriction in occupational asthma combined with inflammatory process. The importance of inflammation in the Moira Chan-Yeung classification of occupational asthma is emphasized. According to this classification several types of occupational asthma are associated with the working environment. It is stressed that continuing prophylaxis of inflammation should protect the worker from irreversible airflow obstruction. This is of special interest to the population suffering from occupational asthma.     

Poly(acrylamide‐co‐itaconic acid) and Semi‐IPNS with Poly(ethylene glycol): Preparation and Characterization

Summary: A pH‐responsive poly(acrylamide‐co‐itaconic acid) (PAAm/IA) hydrogel and semi‐interpenetrating networks (semi‐IPNs) with 5, 10 and 15 wt.‐% of poly(ethylene glycol) (PAAm/IA/PEG), were synthesized. Their swelling behavior was studied in the pH range from 1.76 to 7.81, as well as their oscillatory swelling behavior at pH = 7.81 and pH = 1.7. Throughout these studies, the gels maintained their mechanical strengths and shape. The shear storage (G′) and loss (G″) moduli, obtained as a function of frequency, for the gels as formed and at equilibrium swelling were higher for the semi‐IPNs than for the copolymer hydrogel. The shear storage moduli of copolymer hydrogel and semi‐IPNs as formed were independent of frequency over the whole experimental range, whereas the values for the gels at equilibrium swelling decreased with increasing degree of swelling, i.e., the PAAm/IA hydrogel which exhibited the largest swelling had the lowest G′ value. The G′ and G″ values also depended on the content of PEG.

Diffusion exponent vs. pH for PAAm, copolymer hydrogel PAAm/IA and semi‐IPN with PEG.