Zero expiratory pressure and low oxygen concentration promote heterogeneity of regional ventilation and lung densities.

BACKGROUND: It is not well known what is the main mechanism causing lung heterogeneity in healthy lungs under mechanical ventilation. We aimed to investigate the mechanisms causing heterogeneity of regional ventilation and parenchymal densities in healthy lungs under anesthesia and mechanical ventilation. METHODS: In a small animal model, synchrotron imaging was used to measure lung aeration and regional-specific ventilation (sV̇). Heterogeneity of ventilation was calculated as the coefficient of variation in sV̇ (CVsV̇ ). The coefficient of variation in lung densities (CVD ) was calculated for all lung tissue, and within hyperinflated, normally and poorly aerated areas. Three conditions were studied: zero end-expiratory pressure (ZEEP) and FI O2 0.21; ZEEP and FI O2 1.0; PEEP 12 cmH2 O and FI O2 1.0 (Open Lung-PEEP = OLP). RESULTS: The mean tissue density at OLP was lower than ZEEP-1.0 and ZEEP-0.21. There were larger subregions with low sV̇ and poor aeration at ZEEP-0.21 than at OLP: 12.9 ± 9.0 vs. 0.6 ± 0.4% in the non-dependent level, and 17.5 ± 8.2 vs. 0.4 ± 0.1% in the dependent one (P = 0.041). The CVsV̇ of the total imaged lung at PEEP 12 cmH2 O was significantly lower than on ZEEP, regardless of FI O2 , indicating more heterogeneity of ventilation during ZEEP (0.23 ± 0.03 vs. 0.54 ± 0.37, P = 0.049). CVD changed over the different mechanical ventilation settings (P = 0.011); predominantly, CVD increased during ZEEP. The spatial distribution of the CVD calculated for the poorly aerated density category changed with the mechanical ventilation settings, increasing in the dependent level during ZEEP. CONCLUSION: ZEEP together with low FI O2 promoted heterogeneity of ventilation and lung tissue densities, fostering a greater amount of airway closure and ventilation inhomogeneities in poorly aerated regions.

Trace copper levels in the drinking water, but not zinc or aluminum influence CNS Alzheimer-like pathology.

Mounting evidence suggests copper may influence the progression of Alzheimer's disease by reducing clearance of the amyloid beta protein (Abeta) from the brain. Previous experiments show that addition of only 0.12 PPM copper (one-tenth the Environmental Protection Agency Human consumption limits) to distilled water was sufficient to precipitate the accumulation of Abeta in the brains of cholesterol-fed rabbits (1). Here we report that addition of copper to the drinking water of spontaneously hypercholesterolemic Watanabe rabbits, cholesterol-fed beagles and rabbits, PS1/APP transgenic mice produced significantly enhanced brain levels of Abeta. In contrast to the effects of copper, we found that aluminum- or zinc-ion-supplemented distilled water did not have a significant effect on brain Ab accumulation in cholesterol-fed rabbits. We also report that administration of distilled water produced a reduction in the expected accumulation of Ab in three separate animal models. Collectively, these data suggest that water quality may have a significant influence on disease progression and Ab neuropathology in AD.

Molecular characterization of HLA class II genes in celiac disease patients of Latin American Caucasian origin.

In the present study, the polymorphic domain of HLA class II genes present in a pediatric population of Argentinian celiac disease patients was analyzed by hybridization to sequence-specific oligonucleotides and DNA sequencing. Sixteen out of 16 DR5/7 heterozygous patients bore the DQA1*0501 and DQB1*0201 alleles implicated in the DQ2 risk specificity. The second exon of DQA1, DQB1 and DRB1 genes from 2 DR5/7 patients was characterized by DNA sequencing. The following alleles were found in both patients: DRB1*1101 and DRB1*0701; DQB1*0301 and DQB1*0201; DQA1*0501 and DQA1*0201. Previous serological analysis in this population had shown the presence of DQ2 in 95% of the patients (40% in controls) and a negative association with DQ1 haplotypes, suggesting the presence of other "permissive" or neutral alleles. The following HLA-DQB1 alleles, besides DQB1*0201, were identified in 31 CD patients: DQB1*0301, 0302, 0401 and 0402. All these alleles share a common pattern of residues between positions 84 and 90, and distinct from that present in DQ1-related alleles.

HLA and celiac disease in Argentina: involvement of the DQ subregion.

A population of 62 unrelated homogeneous Argentinian celiac pediatric patients were typed for HLA-A,B,C,DR, and DQ antigens. The association between celiac disease and the DR3 and DR7 antigens was confirmed. The specificity DQw2 was present in 95.2 per cent of the patients. Nevertheless, it was of interest that the most significant phenotypes observed were DR3/DR7, DR7/DR5, and DR3/DR5. The significance of these findings is discussed.

Utilizing a gerontological nursing clinician as a consultant to teach nursing care of aging people.

People over the age of 65 are an increasingly important part of the health care system. Faculty and students of nursing must develop the expertise to work with them if we are to meet the expanding challenges of providing health care to all. Utilizing a gerontological nurse clinician to role model and teach other faculty is one way of developing this expertise and enlarging the cadre of able faculty.