Cardiovascular,hormonal and body fluid changes during prolonged exercise

Summary During prolonged heavy exercise a gradual upward drift in heart rate (HR) is seen after the first 10 min of exercise. This secondary rise might be caused by a reduction in stroke volume due to reduced filling of the heart, which is dependent upon both hemodynamic pressure and blood volume. Swimming and bicycling differ with respect to hydrostatic pressure and to water loss, due to sweating. Five subjects were studied during 90 min of bicycle exercise, and swimming the leg kick of free style. The horizontal position during swimming resulted in a larger cardiac output and stroke volume. After the initial rise in heart rate the secondary rise followed parallel courses in the two situations. The rises were positively related to the measured increments in plasma catecholamine concentrations, which continued to increase as exercise progresssed. The secondary rise in HR could not be explained by changes in plasma volume or in water balance, nor by changes in plasma [K]. The plasma volume decreased 5–6% (225–250 ml) within the first 5 to 10 min of exercise both in bicycling and swimming, but thereafter remained virtually unchanged. The sweat loss during bicycling was four times greater than during swimming; but during swimming the hydrostatic conditions induced a diuresis, so that the total water loss was only 25% less than during bicycling.     

The Effect of Tai Chi on Psychosocial Well-being: A Systematic Review of Randomized Controlled Trials

ObjectiveThis systematic review aimed to critically appraise published clinical trials designed to assess the effect of Tai Chi on psychosocial well-being.Data SourcesDatabases searched included MEDLINE, CINAHL, EMBASE, HEALT, PsycINFO, CISCOM, the Cochrane Central Register of Controlled Trials of the Cochrane Library, and dissertations and conference proceedings from inception to August 2008.Review MethodsMethodological quality was assessed using a modified Jadad scale. A total of 15 studies met the inclusion criteria (i.e. English publications of randomized controlled trials with Tai Chi as an intervention and psychological well-being as an outcome measure), of which eight were high quality trials. The psychosocial outcomes measured included anxiety (eight studies), depression (eight studies), mood (four studies), stress (two studies), general mental health three studies), anger, positive and negative effect, self-esteem, life satisfaction, social interaction and self-rated health (one study each).ResultsTai Chi intervention was found to have a significant effect in 13 studies, especially in the management of depression and anxiety. Although the results seemed to suggest Tai Chi is effective, they should be interpreted cautiously as the quality of the trials varied substantially. Furthermore, significant findings were shown in only six high quality studies. Moreover, significant between group differences after Tai Chi intervention was demonstrated in only one high quality study (the other three significant results were observed in non-high quality studies). Two high quality studies in fact found no significant Tai Chi effects.ConclusionIt is still premature to make any conclusive remarks on the effect of Tai Chi on psychosocial well-being.     

Service quality in hospital wards with different nursing organization: nurses' ratings

Title. Service quality in hospital wards with different nursing organization: nurses’ ratings. Aim. This paper is a report of a study to assess: (1) the relations between nursing organization models in hospital wards and nurses’ perception of the quality of patient care and dimensions of the practice environment, and (2) if these relations were modified by variations in local conditions at the ward level. Background. Previous literature is inconclusive concerning what model of nursing organization maximizes the quality of nursing services. Method. A cross‐sectional survey was carried out in a representative sample of Norwegian hospital wards in 2005. Intra‐ward organization models were classified as: (1) Team leader (n = 30), characterized by extensive responsibilities for team leaders, (2) Primary nurse (n = 18), with extensive responsibilities for named nurses, and (3) Hybrid (n = 37), (1) and (2) combined. We prepared multilevel regression models using scales describing quality of patient care, learning climate, job satisfaction, and relationships with physicians as dependent variables. As independent variables, we used variables representing local ward conditions. Results. Eighty‐seven wards and 1137 nurses (55% response rate) provided complete data. The ward level proportion of variance ranged from 0·10 (job satisfaction) to 0·22 (relationships with physicians). The univariate effect of organization models on quality ratings was not statistically significant. Introducing local ward conditions led to a statistically significant effect of primary nurse organization on relationships with physicians, and to a substantial proportional reduction in ward level variance, ranging from 32% (quality of patient care) to 24% (learning climate). Conclusion. Caution is needed about using service quality arguments when considering the possible benefits and drawbacks of different organizational models.     

The chemical UV-filter 3-benzylidene camphor causes an oestrogenic effect in an in vivo fish assay

Chemical UV-filters are used in sun protection products and various kinds of cosmetics. The lipophilic chemical UV-filter 3-benzylidene camphor was investigated for its capability to cause vitellogenin induction, possibly via oestrogen receptor binding, in a well-established in vivo fish assay (juvenile rainbow trout, Oncorhynchus mykiss, vitellogenin ELISA). A clear relationship was demonstrated between the dose of injected 3-benzylidene camphor and the concentration of plasma vitellogenin with a 105-times induction from 68 mg 3-benzylidene camphor /kg/injection and above compared to the control vitellogenin level. The relationship between the injected dose of 3-benzylidene camphor and the percent of responding fish (vitellogenin) was evaluated by logistic regression analysis and effective dose-values (ED-values) were determined. ED10, ED50 and ED90 of 3-benzylidene camphor after 6 days (2 injections) were 6.4, 16 and 26 mg/kg/ injection, respectively. These ED-values place 3-benzylidene camphor among the more potent xenooestrogens discovered to date and necessitates investigations on the distribution, concentration, persistence and bioaccumulation of 3-benzylidene camphor and other UV-filters in nature.     

Mortality from lung cancer in workers exposed to sulfur dioxide in the pulp and paper industry

Our objective in this study was to evaluate the mortality of workers exposed to sulfur dioxide in the pulp and paper industry. The cohort included 57,613 workers employed for at least 1 year in the pulp and paper industry in 12 countries. We assessed exposure to SO(2) at the level of mill and department, using industrial hygiene measurement data and information from company questionnaires; 40,704 workers were classified as exposed to SO(2). We conducted a standardized mortality ratio (SMR) analysis based on age-specific and calendar period-specific national mortality rates. We also conducted a Poisson regression analysis to determine the dose-response relations between SO(2) exposure and cancer mortality risks and to explore the effect of potential confounding factors. The SMR analysis showed a moderate deficit of all causes of death [SMR = 0.89; 95% confidence interval (CI), 0.87-0.96] among exposed workers. Lung cancer mortality was marginally increased among exposed workers (SMR = 1.08; 95% CI, 0.98-1.18). After adjustment for occupational coexposures, the lung cancer risk was increased compared with unexposed workers (rate ratio = 1.49; 95% CI, 1.14-1.96). There was a suggestion of a positive relationship between weighted cumulative SO(2) exposure and lung cancer mortality (p-value of test for linear trend = 0.009 among all exposed workers; p = 0.3 among workers with high exposure). Neither duration of exposure nor time since first exposure was associated with lung cancer mortality. Mortality from non-Hodgkin lymphoma and from leukemia was increased among workers with high SO(2) exposure; a dose-response relationship with cumulative SO(2) exposure was suggested for non-Hodgkin lymphoma. For the other causes of death, there was no evidence of increased mortality associated with exposure to SO(2). Although residual confounding may have occurred, our results suggest that occupational exposure to SO(2) in the pulp and paper industry may be associated with an increased risk of lung cancer.     

Wernicke's encephalopathy presenting with severe dysphagia: a case report

A 62-year-old man developed dysphagia 4 weeks before the classic symptoms and signs of Wernicke's encephalopathy appeared. Adequate treatment with parenteral thiamine resulted in complete recovery of all symptoms, including his dysphagia. This extraordinary presentation with dysphagia, and the unusual course of the disease, encouraged us to present this case history.     

Quality of care from a patient perspective in population-based cervical cancer screening

In Stockholm, population-based cervical cancer screening is offered free of charge to all women between 23 and 60 years of age. A survey to assess satisfaction with care using a previously validated questionnaire was conducted with 73 women receiving abnormal Pap smear results through the screening program. Thirty-seven women received results of screening within a feasibility project, in which they had extra contact with a midwife prior to receiving standard information and medical follow-up by a gynaecologist. The other 36 women were a matched sample receiving standard information. The results indicate generally high perceptions of quality of care, with particularly high ratings of perceived gynaecological knowledge and medical information provision. Low perceptions of quality were found regarding several aspects of psychosocial care. Higher levels of self-reported psychological well-being were found among the women who had extra midwifery contact. The results indicate that more attention to psychosocial aspects might optimize the screening program.     

Estrogenicity of butylparaben in rainbow trout Oncorhynchus mykiss exposed via food and water

The estrogenic effect of butylparaben was investigated in a rainbow trout Oncorhynchus mykiss test system. Butylparaben was administered orally to sexually immature rainbow trout every second day for up to 10 days in doses between 4 and 74 mgkg(-1)2d(-1) and in the water at 35 and 201 microgl(-1) for 12 days. Plasma vitellogenin was measured before and during the exposures and the concentrations of butylparaben in liver and muscle were determined at the end of experiments. Increases in average plasma vitellogenin levels were seen at oral exposure to 9 mg butylparaben kg(-1)2d(-1). The ED50 values for increase in vitellogenin synthesis were 46, 29 and 10.5 mg butylparaben kg(-1)2d(-1), respectively, at day 3, 6 and 12. Exposure to 201 microg butylparaben l(-1) increased vitellogenin synthesis, but exposure to 35 microgl(-1) did not. Butylparaben showed little tendency to bioaccumulation in rainbow trout; less than 1 per thousand of the total amount of butylparaben administered orally at 51 mgkg(-1)2d(-1) over the 12 days experimental period was retained in liver at the end of the experiment. After 12 days exposure to 35 and 201 microg butylparaben l(-1), plasma concentrations were 9 and 183 microgl(-1), respectively, and for the fish exposed to 201 microgl(-1) there was a positive correlation between concentrations of vitellogenin and butylparaben in the plasma. On the assumption that butylparaben removed from the water phase during water exposure were taken up into the fish, butylparaben uptake rates in the fish exposed to 35 and 201 microg butylparaben l(-1) were 13 and 78 mgkg(-1)day(-1), respectively.     

Exposure and airway effects of seafood industry workers in northern Norway

OBJECTIVE: In this study, we explored airway symptoms and exposure to bioaerosols and exhaust gases in seafood industry plants. METHODS: The study details the results from personal and environmental exposure measurements (17 plants), a questionnaire (n = 984), and clinical examinations (n = 225). RESULTS: The workers were exposed to allergens, endotoxins, molds, and exhaust. The 1-year prevalence of work-related airway symptoms was 42.8% for production workers and 25.9% for administrative workers. Mean levels of forced expiratory volume in 1 second and forced vital capacity were less than the predicted values in all exposed nonsmoker groups. A total of 20.5% had increased levels of total IgE (>/=100 kU/L). Specific IgE-mediated reactions seemed to be relevant only in the shrimp industry. CONCLUSIONS: Seafood industry workers showed a high prevalence of work-related airway symptoms. Further research on the relationship between exposure and effects is necessary.     

Evidence for a single-step mechanism in the origin of hyperdiploid childhood acute lymphoblastic leukemia

High hyperdiploidy (>50 chromosomes) in childhood acute lymphoblastic leukemia (ALL) is characterized by nonrandom multiple trisomies and tetrasomies involving in particular chromosomes X, 4, 6, 8, 10, 14, 17, 18, and 21. This characteristic karyotypic pattern, the most common in pediatric ALL, may arise via a tetraploid state with subsequent loss of chromosomes, by sequential gains of chromosomes in consecutive cell divisions, or by simultaneous gain of chromosomes in a single mitosis. These alternatives may be distinguished by investigation of the allelic ratios of loci on the tetrasomic and disomic chromosomes. Previous studies of tetrasomy 21 and of the occurrence of uniparental disomies (UPDs) have suggested that the most likely mechanism is simultaneous gain. However, the other pathways have not been definitely excluded because complete analyses of all disomies and tetrasomies have never been performed. In the present study, we investigated 27 hyperdiploid ALLs by using 58 polymorphic microsatellite markers mapped to 23 of the 24 human chromosomes. Twenty-six tetrasomies were analyzed (involving chromosomes X, 8, 10, 14, 18, and 21), and the frequency of UPDs was determined in 10 cases. In total, 200 chromosomes were studied. Equal allele dosage was observed in 24 of 26 tetrasomies, and only 7 UPDs were found. These data strongly suggest that hyperdiploidy in childhood ALL generally arises by a simultaneous gain of all additional chromosomes in a single abnormal mitosis.