Am J Physiol Lung Cell Mol Physiol
June 2008
Mechanical ventilation with high tidal volumes (HV(T)) impairs lung liquid clearance (LLC) and downregulates alveolar epithelial Na-K-ATPase. We have previously reported that the Na-K-ATPase alpha(2)-subunit contributes to LLC in normal rat lungs. Here we tested whether overexpression of Na-K-ATPase alpha(2)-subunit in the alveolar epithelium would increase clearance in a HV(T) model of lung injury.
View Article and Find Full Text PDFIEEE Trans Ultrason Ferroelectr Freq Control
October 2012
Spread spectrum pulse compression is a signal processing algorithm that enhances critical system performance parameters such as signal-to-noise ratio, peak power requirements, minimum detectable signal, and total dynamic range. For this research, a digital, real-time, Barker coded, bi-phase modulator was designed and constructed, as well as a simple ultrasonic test tank containing both synthetic targets and excised goat's liver. Upon reception and demodulation of the spread spectrum ultrasonic echo, cross-correlation with a sidelobe suppression filter was performed.
View Article and Find Full Text PDFHypercapnia (elevated CO(2) levels) occurs as a consequence of poor alveolar ventilation and impairs alveolar fluid reabsorption (AFR) by promoting Na,K-ATPase endocytosis. We studied the mechanisms regulating CO(2)-induced Na,K-ATPase endocytosis in alveolar epithelial cells (AECs) and alveolar epithelial dysfunction in rats. Elevated CO(2) levels caused a rapid activation of AMP-activated protein kinase (AMPK) in AECs, a key regulator of metabolic homeostasis.
View Article and Find Full Text PDFBackground: In patients with acute respiratory failure, gas exchange is impaired due to the accumulation of fluid in the lung airspaces. This life-threatening syndrome is treated with mechanical ventilation, which is adjusted to maintain gas exchange, but can be associated with the accumulation of carbon dioxide in the lung. Carbon dioxide (CO2) is a by-product of cellular energy utilization and its elimination is affected via alveolar epithelial cells.
View Article and Find Full Text PDFInt J Occup Environ Health
December 2007
Manufacturers of asbestos brakes, supported by many manufacturing and insurance industry amicus curie, requested the Michigan Supreme Court to dismiss testimony of an expert regarding the ability of asbestos dust from brakes to cause mesothelioma as "junk science". Scientists are concerned with the sweeping and unequivocal claims that any conclusion that asbestos from brakes caused a signature asbestos-related disease in a particular person must be "junk science". The manufacturers' sweeping pronouncements are what veer from accepted, reliable mainstream scientific methods and conclusions.
View Article and Find Full Text PDFAm J Respir Cell Mol Biol
January 2008
Carbonic anhydrase II (CAII) plays an important role in carbon dioxide metabolism and intracellular pH regulation. In this study, we provide evidence that CAII is expressed in both type I (AECI) and type II (AECII) alveolar epithelial cells by RT-PCR and Western blotting in freshly isolated rat cells. These results were further confirmed by double immunostaining with CAII antibodies and AECI- or AECII-specific markers in freshly isolated alveolar epithelial cells and rat lung tissues.
View Article and Find Full Text PDFAs a cellular adaptative response, hypoxia decreases Na,K-ATPase activity by triggering the endocytosis of its alpha(1) subunit in alveolar epithelial cells. Here, we present evidence that the ubiquitin conjugating system is important in the Na,K-ATPase endocytosis during hypoxia and that ubiquitination of Na,K-ATPase alpha(1) subunit occurs at the basolateral membrane. Endocytosis and ubiquitination were prevented when the Ser 18 in the PKC phosphorylation motif of the Na,K-ATPase alpha(1) subunit was mutated to an alanine, suggesting that phosphorylation at Ser-18 is required for ubiquitination.
View Article and Find Full Text PDFInt J Occup Environ Health
May 2007
Injury rates in all industries and in construction in particular have been declining. Inconsistencies in the information suggest some of the apparent decrease may be due to changes in the ways injuries are treated, misclassification of employees, or underreporting. Lost-time injury rates for the largest construction employers declined by as much as 92% between 1988 and 1999.
View Article and Find Full Text PDFIn 1985, the Sheet Metal Workers International Association and the Sheet Metal and Air Conditioning National Association formed The Sheet Metal Occupational Health Institute Trust to examine the health hazards of the sheet metal industry in the United States and Canada. Between 1986 and 2004, 18,211 individuals were examined. The mean age of this cohort was 57.
View Article and Find Full Text PDFBackground: In the past, diffuse malignant peritoneal mesothelioma (DMPM) was regarded as a preterminal condition. The length of survival was dependent upon the aggressive versus indolent biologic behavior of the neoplasm. The overall median survival was approximately 1 year after systemic chemotherapy.
View Article and Find Full Text PDFConstruction workers were and are considered temporary workers at many construction sites. Since World War II, large numbers of construction workers were employed at U.S.
View Article and Find Full Text PDFBrick masons and mason tenders report a high prevalence of work-related musculoskeletal disorders (WMSDs), many of which can be prevented with changes in materials, work equipment or work practices. To explore the use of "best practices" in the masonry industry, NIOSH organized a 2-day meeting of masonry stakeholders. Attendees included 30 industry representatives, 5 health and safety researchers, 4 health/safety specialists, 2 ergonomic consultants, and 2 representatives of state workers' compensation programs.
View Article and Find Full Text PDFAlthough attentional biases have been demonstrated in individuals with posttraumatic stress disorder (PTSD), the cognitive methodologies used have not allowed for disambiguation of two types of attentional biases. It remains unclear if PTSD involves difficulty disengaging attention from threatening stimuli (interference) or facilitated detection. To differentiate between attentional interference and facilitation, 57 male Vietnam-era veterans (30 High PTSD and 27 Low PTSD) completed a visual search task with a lexical decision component.
View Article and Find Full Text PDFBackground: Development of the enteric nervous system (ENS) requires interactions between migrating neural crest cells and the nascent gastrointestinal tract that are dependent upon genes expressed by both cell compartments. Hlx, a homeobox transcription factor gene that is expressed in mouse intestinal and hepatic mesenchyme, is required for normal embryonic growth of intestine and liver, and the Hlx-/- genotype is embryonic lethal. We hypothesized that Hlx is required for ENS development.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
November 2006
Alveolar fluid reabsorption (AFR) is important in keeping the air spaces free of edema. This process is accomplished via active transport of Na(+) across the alveolo-capillary barrier mostly by apical Na(+) channels and basolateral Na(+)-K(+)-ATPases. Recently, we have reported that acute elevation of left atrial pressures is associated with decreased AFR in isolated rat lungs.
View Article and Find Full Text PDFObjective: To examine whether African Americans are informed about hospice services, and to examine demographic or disease factors that may influence receipt of information about hospice.
Design: Retrospective cohort study.
Setting: Twenty-two states that accounted for nearly 70% of deaths in the United States in 2000.
Ambient particulate matter is increasingly recognized as a significant contributor to human cardiopulmonary morbidity and mortality in the United States and worldwide. We sought to determine whether exposure to ambient particulate matter would alter alveolar fluid clearance in mice. Mice were exposed to a range of doses of a well-characterized particulate matter collected from the ambient air in Düsseldorf, Germany through a single intratracheal instillation, and alveolar fluid clearance and measurements of lung injury were made.
View Article and Find Full Text PDFObjectives: The aim of this study was to profile construction workers' injuries for more information about the causes of nonfatal construction worker injuries and identify injury trends for further investigations and prevention programs.
Methods: An injury-tracking program for emergency departments was established in 1990 to gather the data needed for the study. Profiles were obtained for 2916 construction workers' injuries that were identified on hospital registration forms at the George Washington University Emergency Department in Washington, DC, from November 1990 through October 1997.
Background: Medical screening programs at three Departments of Energy (DOE) nuclear weapons facilities (Hanford Nuclear Reservation, Oak Ridge, and the Savannah River Site) have included audiometric testing since approximately 1996. This report summarizes hearing evaluations through March 31, 2003.
Methods: Occupational examinations included a medical history, limited physical examination, and tests for medical effects from specific hazards, including audiometric testing.
Purpose: The purpose of this study is to expand knowledge regarding end-of-life care received in nursing homes through the use of narrative interviews with family members close to the decedents.
Design And Methods: We conducted follow-up qualitative interviews with 54 respondents who had participated in an earlier national survey of 1,578 informants. Interviews were taped and transcribed and then coded by a five-member, multidisciplinary team to identify overarching themes.
Objectives: To understand the roles of physicians and staff in nursing homes in relation to end-of-life care through narrative interviews with family members close to a decedent.
Design: Qualitative follow-up interviews with 54 respondents who had participated in an earlier national survey of 1,578 informants.
Setting: Brown University interviewers conducted telephone interviews with participants throughout the United States.
Int J Occup Environ Health
November 2005
The proportion of peritoneal mesotheliomas among all mesotheliomas has been decreasing, leading some to suggest that peritoneal mesothelioma occurs only after high levels of exposure to asbestos. To investigate the relationship between asbestos exposure and the development of peritoneal mesothelioma, a case-control study examined 40 cases of primary peritoneal mesothelioma from a single institution. This series differed from previous reports in that 75% of the cases and controls had attended college.
View Article and Find Full Text PDFObjectives: To compare the end-of-life medical care experienced by African-American and white decedents and their families.
Design: Cross-sectional, retrospective survey with weighted results based on a two-stage probability sampling design.
Setting: Hospitals, nursing homes, and home-based medical services across the United States.