Nonmarine crenarchaeol in Nevada hot springs.
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Glycerol dialkyl glycerol tetraethers (GDGTs) are core membrane lipids of the Crenarchaeota. The structurally unusual GDGT crenarchaeol has been proposed as a taxonomically specific biomarker for the marine planktonic group I archaea. It is found ubiquitously in the marine water column and in sediments. In this work, samples of microbial community biomass were obtained from several alkaline and neutral-pH hot springs in Nevada, United States. Lipid extracts of these samples were analyzed by high-performance liquid chromatography-mass spectrometry and by gas chromatography-mass spectrometry. Each sample contained GDGTs, and among these compounds was crenarchaeol. The distribution of archaeal lipids in Nevada hot springs did not appear to correlate with temperature, as has been observed in the marine environment. Instead, a significant correlation with the concentration of bicarbonate was observed. Archaeal DNA was analyzed by denaturing gradient gel electrophoresis. All samples contained 16S rRNA gene sequences which were more strongly related to thermophilic crenarchaeota than to Cenarchaeum symbiosum, a marine nonthermophilic crenarchaeon. The occurrence of crenarchaeol in environments containing sequences affiliated with thermophilic crenarchaeota suggests a wide phenotypic distribution of this compound. The results also indicate that crenarchaeol can no longer be considered an exclusive biomarker for marine species. (+info)
Tuberculosis transmission in a renal dialysis center--Nevada, 2003.
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Among persons with chronic renal failure, infection with Mycobacterium tuberculosis is more likely to progress to tuberculosis (TB). Chronic renal failure is an immunocompromising condition associated with cutaneous anergy, which can result in a false-negative tuberculin skin test (TST) result. In 2003, a health-care worker (HCW) (i.e., a hemodialysis technician) in an outpatient renal dialysis center in Nevada became ill with pulmonary TB, exposing more than 400 patients and other employees. The HCW had a previous positive TST result but never received treatment for TB infection. This report summarizes the results of a contact investigation, which suggested that the HCW had transmitted M. tuberculosis to 29 patients and 13 employees. The findings underscore the need for TB screening and treatment of TB infection for all HCWs and patients at high risk. (+info)
The interplay of cutaneous water loss, gas exchange and blood flow in the toad, Bufo woodhousei: adaptations in a terrestrially adapted amphibian.
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Toads experiencing dehydrating conditions exhibit complex physiological and behavioral responses, some of which can potentially impact cutaneous gas exchange, an important component of total gas exchange. We measured the effect of dehydration on cutaneous gas exchange in the xeric-adapted toad Bufo woodhousei. First, two pharmacological agents were used to stimulate cutaneous blood flow--phentolamine (an alpha-blocker) and isoproterenol, a beta-stimulant and powerful cardio-accelerator--to determine a relationship between cutaneous blood flow and water loss. Both drugs increased heart rate and blood pressure, and caused visually evident extensive vasodilation of the skin. Untreated toads in a dry air stream took an average of 10.1+/-0.7 h to dehydrate to 80% body mass, while animals treated with isoproterenol and phentolamine requires only 7.2+/-0.8 h and 7.4+/-0.9 h, respectively. Rehydration, which was more rapid than dehydration, was similarly accelerated in pharmacologically treated toads. Cutaneous gas exchange (M(O2), M(CO2)) and C18O diffusing capacity (D(Skin)C18O) were then examined in unanesthetized toads under different states of body hydration. Blood gases and hematocrit were measured separately but under identical conditions. In fully hydrated toads at 23-25 degrees C, cutaneous gas exchange values were: M(O2) = 1.43+/-0.47 micromol g(-1) h(-1), M(CO2) = 1.75+/-0.85 micromol g(-1) h(-1), and the respiratory exchange ratio R = 1.36+/-0.56 (N=6, mean + 1 S.D.). D(Skin)C18O was 0.48+/-0.03 micromol g body mass(-1) h(-1) kPa. Following an enforced 20-25% loss of body water, D(Skin)C18O fell by nearly 50% to 0.28+/-0.09 micromol g(-1) h(-1) kPa. However, cutaneous M(O2), M(CO2) and R were unchanged at 1.48+/-0.15 micromol g(-1) h(-1), 1.72+/-0.29 micromol g(-1) h(-1) and 1.13+/-0.08 micromol g(-1) h(-1), respectively. Partial pressure of arterial (sciatic) oxygen, Pa(O2), normally about 12-13 kPa, remained unchanged by dehydration, but Pa(CO2) increased about 250% from 0.93+/-0.27 up to 2.27+/-0.93 kPa. The fall in D(Skin)C18O during dehydration presumably results at least in part from decreased cutaneous blood flow, possibly in an attempt to reduce the transcutaneous water loss that would otherwise result during dehydrating conditions. Concurrently, cutaneous M(CO2) is maintained under dehyrdating conditions by a greatly increased Pa(CO2) diffusion gradient across the skin. Thus, Bufo woodhousei appears able to restrict cutaneous blood flow without compromising vital cutaneous CO2 loss. (+info)
Work-related pain and injury and barriers to workers' compensation among Las Vegas hotel room cleaners.
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OBJECTIVES: We examined the prevalence of work-related pain and injury and explored barriers to and experiences of reporting among workers. METHODS: We surveyed 941 unionized hotel room cleaners about work-related pain, injury, disability, and reporting. RESULTS: During the past 12 months, 75% of workers in our study experienced work-related pain, and 31% reported it to management; 20% filed claims for workers' compensation as a result of work-related injury, and 35% of their claims were denied. Barriers to reporting injury included "It would be too much trouble" (43%), "I was afraid" (26%), and "I didn't know how" (18%). An estimated 69% of medical costs were shifted from employers to workers. CONCLUSIONS: The reasons for underreporting and the extent of claim denial warrant further investigation. Implications for worker health and the precise quantification of shifting costs to workers also should be addressed. (+info)
Nevada's academic-practice collaboration: public health preparedness possibilities outside an academic center.
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The Nevada State Health Division developed a local academic-practice partnership with the University of Nevada Reno's Master of Public Health Program to assess the bioterrorism risk communication, information, response, and training needs of professional and public stakeholder groups throughout Nevada. Between October 16, 2002, and April 13, 2004, 22 needs assessment focus groups and 125 key informant interviews were conducted to gather information on the diverse needs of the stakeholders. The themes that emerged from these activities included the need for effective pre-event education and training; a coordinated and responsive public health preparedness infrastructure; honest, accurate, and timely communication in the event of a bioterrorism situation; and appropriate information dissemination methods and technology. The data collected through this needs assessment gave the Nevada State Health Division vital information to plan public health preparedness initiatives. The establishment of local academic-practice partnerships for states without a Centers for Disease Control and Prevention-funded Academic Center for Public Health Preparedness is an effective way for health departments to develop their public health preparedness infrastructure while simultaneously training the future public health workforce. (+info)
Environmental hypoxia influences hemoglobin subunit composition in the branchiopod crustacean Triops longicaudatus.
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Hemoglobin (Hb) is a highly conserved protein that provides a vital link between environmental oxygen and its use and/or storage within an organism. While ubiquitous among vertebrates, Hb occurs frequently in invertebrate phyla as well. Many arthropod species use the copper-binding pigment hemocyanin, but unique in this phylum are the branchiopod crustaceans, which express Hb. Branchiopod Hb concentration and structure are exquisitely sensitive to environmental oxygen availability. Hemoglobin concentration and oxygen-binding affinity increase with decreasing oxygen tension in Daphnia, Artemia and Triops. The change in binding affinity is attributed to differential Hb subunit expression in Daphnia and Artemia but remains unclear for Triops. This is the first study to demonstrate developmental plasticity of Hb subunit expression in a notostracan, Triops longicaudatus, reared under conditions of varying oxygen availability. In response to variable oxygen environments, T. longicaudatus differentially express four primary Hb subunits ranging between 30 and 34 kDa, with normoxic-reared animals expressing primarily the heavier subunits, and hypoxic-reared animals expressing increased proportions of the lower molecular mass subunits. Moreover, differential Hb subunit expression is induced upon transfer of normoxic-reared adults to a hypoxic environment, such that the distribution of Hb subunits in the transferred adults becomes similar to that of hypoxic-reared animals. Two-dimensional gel electrophoresis and follow-up analyses revealed several isoforms of Hb subunits that may represent differential gene expression and/or post-translational modification. Unlike Daphnia and Artemia, the Hb hypoxic response in Triops is not reversible in that there was no significant decrease in Hb concentration or change in Hb subunit expression pattern when hypoxic-reared adults were transferred to a normoxic environment. (+info)
Racial/ethnic variations in veterans' ambulatory care use.
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OBJECTIVES: We assessed racial/ethnic variations in patterns of ambulatory care use among Department of Veterans Affairs (VA) health care-eligible veterans to determine if racial/ethnic differences in health care use persist in equal-access systems. METHODS: We surveyed 3227 male veterans about their health and ambulatory care use. RESULTS: Thirty-eight percent of respondents had not had a health care visit in the previous 12 months. Black (odds ratio [OR] = 0.5), Hispanic (OR = 0.4), and Asian/Pacific Islander veterans (OR=0.4) were less likely than White veterans to report any ambulatory care use. Alternately, Whites (OR=2.2) were more likely than other groups to report ambulatory care use. Being White was a greater predictor of health care use than was having fair or poor health (OR=1.4) or functional limitations (OR=1.5). In non-VA settings, racial/ethnic minorities were less likely to have a usual provider of health care. There was no VA racial/ethnic variation in this parameter. CONCLUSIONS: Racial/ethnic disparities in health and health care use are present among VA health care-eligible veterans. Although the VA plays an important role in health care delivery to ethnic minority veterans, barriers to VA ambulatory care use and additional facilitators for reducing unmet need still need to be investigated. (+info)
Direct access use by experienced therapists in states with direct access.
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Direct access use among experienced therapists practicing in states with 3 years' experience with direct access was studied, as were differences between therapists who had and had not practiced through direct access. A questionnaire was mailed to 250 members of the North Carolina, Nevada, and Utah chapters of the American Physical Therapy Association. Almost half (44.5%) of the respondents had practiced through direct access; an estimated 10.3% of their caseload was seen through direct access. Reasons for not practicing through direct access were that the employer does not permit direct access practice (49.1%), insurance does not reimburse for direct access practice (43.6%), no patients have been seen without referral (25.5%), and personal preference to treat by referral only (23.6%). Therapists who had treated patients through direct access were significantly more likely to believe that direct access had benefited them professionally and benefited their patients than were therapists who had not practiced through direct access. (+info)