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Biomedical subjects

S Stock

Publications and source records attributed to S Stock.

At least 19 recordsLinked to original sources

Standing, sitting and associated working conditions in the Quebec population in 1998.

Working posture is an important determinant of musculoskeletal and vascular health. Knowledge of the context and type of postures is necessary in order to examine their associations with health-related outcomes. This study describes self-reported usual working postures in a population and their associations with other working conditions and demographic variables. The 1998 Quebec Health and Social Survey is a population-based survey of 11,986 private households in the province of Quebec. It contained a self-administered questionnaire, including an extensive occupational health section. The analyses in this study were limited to respondents with paid employment who had at least 6 months seniority in their current job, comprising 9,425 subjects. The overall prevalence of usual work in a standing posture is 58%; it is more common among men, workers under 25 years, those in the two lowest educational quintiles and those with incomes under 20,000 Canadian dollars. Only one person in six who works standing reports being able to sit at will. Women and men differ in the types of usual standing and sitting postures at work. Those who work standing and/or who work in more constrained postures are more likely to be exposed to other physical work demands, such as handling heavy loads, repetitive work, forceful exertion and low job decision latitude. The association between decision latitude and constrained postures is an important link between psychosocial and physical stressors in the workplace. In epidemiological studies, exposure covariation and interactions should be considered in the generation and interpretation of the associations between work postures and musculoskeletal disorders.

Decision Making↗

Asthma: prevalence and cost of illness.

The purpose of this study was to estimate the prevalence and cost of illness of asthma in Germany by retrospectively analysing routine health insurance data. This analysis investigated claims data from all insured persons of six large sickness funds. Insurants with asthma were identified via the International Classification of Diseases (ninth revision) diagnosis and the Anatomical Therapeutic Chemical Classification System Code for regular medication prescriptions. Costs for hospital care, medication and sick benefit were taken from claims data. Costs for rehabilitation, premature death and early retirement were estimated using the human capital approach and data from national statistics. Prevalence of asthma in the German statutory health insurance was 6.34%. Total costs for asthma, including direct and indirect costs, were calculated at euro 2.74 billion during 1999. The prevalence of asthma in the German statutory health insurance has previously been estimated to be 4-6%. The results of this large study show the prevalence of asthma in the German social insurance system to be approximately 6%. The study also indicates that there is room for substantial savings in the German social insurance system, with indirect costs amounting to 74.8% of total costs and payment of sick benefits through the sickness funds amounting to 58.3% of indirect costs. These costs may be reduced with better asthma control in patients.

Adolescent↗

[Performance and costs of outpatient clinics of university hospitals for medical care, teaching, research activities].

BACKGROUND: Outpatient clinics of university hospitals (Hochschulambulanzen) play a significant role in the German health care system. Universities have in contrast to other hospitals the right to implement an outpatient clinic, but the health care services they can render are restricted to clinical research and teaching activities. The university outpatient clinic study evaluates the intensity of medical care, teaching, research activities, and the related costs. METHOD AND DATABASE: 6 university hospitals with 51 outpatient departments in Germany were included. The prospective documentation of consultations was restricted to 800 visits per department. A total of 26,312 consultations with approximately 40,000 diagnoses and 150,000 services were documented. Furthermore, data concerning costs, teaching activities and research facilities were documented. RESULTS: Clinical treatment without any correlation to research or teaching activities amounted to about 81 % of the working time in the outpatient department (research 11 %; teaching 8 %). The primary task of the university outpatient clinics takes up less than 20 % of the working time. The physicians documented that the disease of every fourth visit was in accordance with their main field of research. 6.9 % of the visits were asked to take part in clinical trials, of these 1.25 % were included for the first time, 3.7 % were already included. 6.5 % of the visits were addressed to participate in specific teaching activities. The average total costs per case added up to 149 Euro. No outpatient clinic could cover the total per case costs with the lump sum payments. On the average 31 % of these costs were covered by lump sum payments (without cases concerning research and teaching). CONCLUSION: Treatment in outpatient departments of university clinics is far beyond research and teaching activities required by law. However, the ability of outpatient departments of universities to provide excellent outpatient services should have a more dominant role in the health care system. Therefore access to care should be deregulated for the patients and reimbursement schemes should be adjusted to adjust for the present losses.

Biomedical Research↗

Pathological calcification in juvenile dermatomyositis (JDM): microCT and synchrotron x-ray diffraction reveal hydroxyapatite with varied microstructures.

The objective of this study was to begin to relate the microstructure of calcinosis samples to clinical and laboratory characteristics of the juvenile dermatomyositis (JDM) patients. Laboratory x-ray microCT (micro-Computed Tomography) noninvasively mapped microstructure for the first time in JDM calcifications. Synchrotron x-ray diffraction (transmission geometry) identified the mineral phase and crystallite size in the deposits. Samples were obtained from four children who had active JDM longer than 80 months and who were typed for TNFalpha-308 allele polymorphisms. Uniform mineral (giving the appearance of an extruded solid) was observed in one patient, and irregular blocks of differing sizes filled the samples from two other patients. The sample from the fourth patient appeared to combine features of the other two types. These spatial distributions of mineral were quite different from those in a bone reference sample. The only mineral observed in the JDM samples was hydroxyapatite (HAP), and the diffraction peaks of the JDM samples were slightly narrower than those of a trabecular bone reference sample. Diffraction peak widths of the JDM specimens revealed crystallite sizes (approximately 220-240 A) that are comparable to values reported in the literature for bone. Three children were positive for TNFalpha-308 GA polymorphism. The data suggest several possible origins for blocky vs. uniform structure of the JDM calcifications, including differences in duration of untreated inflammation, in TNFalpha-308 polymorphism, and in mechanical constraint at the calcification site. Information from additional samples is required to determine the relative role of each of these factors. Taken together, non-invasive microCT and x-ray diffraction characterization on the same samples offer an informative window into the dystrophic mineralization process in JDM.

Adolescent↗

Management of return-to-work programs for workers with musculoskeletal disorders: a qualitative study in three Canadian provinces.

In this qualitative research project, researchers in three Canadian provinces explored the perceptions of many different actors involved in return-to-work (RTW) programs for injured workers, studying their views on successful RTW strategies and barriers to/facilitators of the RTW process, then analyzing the underlying dynamics driving their different experiences. Each research team recruited actors in a variety of different workplaces and key informants in the RTW system, and used a combination of in-depth, semi-structured interviews and focus groups to collect data, which were coded using an open coding system. Analysis took a social constructionist perspective. The roles and mandates of the different groups of actors (injured workers; other workplace actors; actors outside the workplace), while sometimes complementary, could also differ, leading to tension and conflict. Characteristics of injured workers described as influencing RTW success included personal and sociodemographic factors, beliefs and attitudes, and motivation. Human resources managers and health care professionals tended to attribute workers' motivation to their individual characteristics, whereas injured workers, worker representatives and health and safety managers described workplace culture and the degree to which workers' well-being was considered as having a strong influence on workers' motivation. Some supervisors experienced role conflict when responsible for both production quotas and RTW programs, but difficulties were alleviated by innovations such as consideration of RTW program responsibilities in the determination of production quotas and in performance evaluations. RTW program success seemed related to labor-management relations and top management commitment to Health and Safety. Non-workplace issues included confusion stemming from the compensation system itself, communication difficulties with some treating physicians, and role conflict on the part of physicians wishing to advocate for patients whose problems were non-compensable. Several common themes emerged from the experiences related by the wide range of actors including the importance of trust, respect, communication and labor relations in the failure or success of RTW programs for injured workers.

Accidents, Occupational↗

Severe degree of hyperglycaemia: insights from integrative physiology.

We illustrate how the application of principles of integrative physiology at the bedside can reveal novel insights that have been largely overlooked to this day. In this didactic exercise, modern-day physicians seek an imaginary medical consultation with Professor Sir Hans Krebs because of an unusual finding in his area of expertise: a very severe degree of hyperglycaemia. Although Professor Krebs is restricted to data prior to World War II, this does not prevent him from making novel discoveries. First, he illustrates how an occult factor, rapid absorption of glucose from the intestinal tract, was a critical feature in explaining the basis of the severe degree of hyperglycaemia without obvious ketoacidosis in a 16-year-old patient with type 1 diabetes mellitus in poor control. Second, by examining simple principles of renal and gastrointestinal physiology in a quantitative fashion, Professor Krebs speculates as to how cerebral oedema might occur before therapy in a patient with a severe degree of hyperglycaemia. We hope that readers and educators will appreciate the value of applying principles of integrative physiology in a quantitative fashion at the bedside.

Adolescent↗

Cost-benefit and cost-effectiveness analysis of a disability prevention model for back pain management: a six year follow up study.

AIMS: To test the long term cost-benefit and cost-effectiveness of the Sherbrooke model of management of subacute occupational back pain, combining an occupational and a clinical rehabilitation intervention. METHODS: A randomised trial design with four arms was used: standard care, occupational arm, clinical arm, and Sherbrooke model arm (combined occupational and clinical interventions). From the Quebec WCB perspective, a cost-benefit (amount of consequence of disease costs saved) and cost-effectiveness analysis (amount of dollars spent for each saved day on full benefits) were calculated for each experimental arm of the study, compared to standard care. RESULTS: At the mean follow up of 6.4 years, all experimental study arms showed a trend towards cost benefit and cost effectiveness. These results were owing to a small number of very costly cases. The largest number of days saved from benefits was in the Sherbrooke model arm. CONCLUSIONS: A fully integrated disability prevention model for occupational back pain appeared to be cost beneficial for the workers' compensation board and to save more days on benefits than usual care or partial interventions. A limited number of cases were responsible for most of the long term disability costs, in accordance with occupational back pain epidemiology. However, further studies with larger samples will be necessary to confirm these results.

Absenteeism↗

Observation of coherent transients in ultrashort chirped excitation of an undamped two-level system.

The effects of coherent excitation of a two-level system with a linearly chirped pulse are studied theoretically and experimentally [in Rb (5s-5p)] in the low field regime. The coherent transients are measured directly on the excited state population on an ultrashort time scale. A sharp step corresponds to the passage through resonance. It is followed by oscillations resulting from interferences between off-resonant and resonant contributions. We finally show the equivalence between this experiment and Fresnel diffraction by a sharp edge.

Journal Article↗

Summary of the practice parameter for the use of stimulant medications in the treatment of children, adolescents, and adults.

This practice parameter describes treatment with stimulant medication. It uses an evidence-based medicine approach derived from a detailed literature review and expert consultation. Stimulant medications in clinical use include methylphenidate, dextroamphetamine, mixed salts of amphetamine, and pemoline. They carry U.S. Food and Drug Administration indications for the treatment of attention-deficit hyperactivity disorder.

Adolescent↗

Summary of the practice parameter for the prevention and management of aggressive behavior in child and adolescent psychiatric institutions with special reference to seclusion and restraint.

This parameter reviews the current state of the prevention and management of child and adolescent aggressive behavior in psychiatric institutions, with particular reference to the indications and use of seclusion and restraint. It also presents guidelines that have been developed in response to professional, regulatory, and public concern about the use of restrictive interventions with aggressive patients with regard to personal safety and patient rights. The literature on the use of seclusion, physical restraint, mechanical restraint, and chemical restraint is reviewed, and procedures for carrying out each of these interventions are described. Clinical and regulatory agency perspectives on these interventions are presented. Effectiveness, indications, contraindications, complications, and adverse effects of seclusion and restraint procedures are addressed. Interventions are presented to provide more opportunities to promote patient independence and satisfaction with treatment while diminishing the necessity of using restrictive procedures.

Adolescent↗

Mutagenic properties of 1,2,3,4-tetrahydronaphthaline-1-hydroperoxide, a model compound for organic peroxides in Diesel exhaust.

The genotoxicity of the organic peroxide 1,2,3,4-tetrahydronaphthaline-1-hydroperoxide (or tetraline-1-hydroperoxide, THP) was investigated in the Ames assay without a metabolic activating system using Salmonella typhimurium strains TA 98, TA 100, and TA 102. THP served as a model compound for higher organic peroxides, which can arise from autoxidation of hydrocarbons, e.g. in Diesel exhaust. While THP induced no mutagenic response in S. typhimurium TA 98, it was directly mutagenic in strains TA 100 and TA 102. These data, along with findings on mutagenic properties of other alkyl hydroperoxides, suggest that such compounds deserve further investigation regarding their genotoxic potential and occurrence in the environment.

Models, Chemical↗

Thirst and vasopressin secretion counteract dehydration in newborn infants.

OBJECTIVE AND STUDY DESIGN: Our goal was to study the water balance in healthy breast-fed infants (n = 139) during their first 5 days, by cross-sectional measurements of body weight, serum sodium, serum osmolality, and hematocrit. We also investigated infants' capacity to conserve body water by increased secretion of vasopressin, the main antidiuretic hormone in human beings. RESULTS: The maximal body weight reduction was 5.7% +/- 1.7% (mean +/- SD) of birth weight and most infants started to gain weight when they were 3 days old. The serum sodium level at 16 +/- 4 hours (on day of birth) was 142 mmol/L; the level increased after 1 day (p < 0.01) and remained constantly high for the following 2 days (p < 0.05). The serum osmolality was increased at 1 day (p < 0.01) and 2 days (p < 0.05) compared with the value on the day of birth (296 mOsm/kg). The plasma vasopressin level was constant up to 24 hours (1 day), but decreased during the next 2 days (p < 0.01). Infants with body weight reduction exceeding 10% (n = 15) had a further elevation of the serum sodium level (p < 0.0001) and serum osmolality (p < 0.0001), and the plasma vasopressin level was twofold higher (p < 0.0001) compared with corresponding levels in infants with less weight reduction. These infants also had a reduced interval between two subsequent feedings (p < 0.001). The hematocrit remained unchanged irrespective of the degree of weight reduction. CONCLUSIONS: When the reduction of body weight exceeds 10%, the newborn infant releases vasopressin in response to fluid hypertonicity. This state also affects feeding behavior, perhaps as an expression of thirst. It is likely that hormone release is also stimulated in parallel with a weight reduction of less than 10%, because it is also accompanied by a hyperosmotic state.

Body Weight↗

Carpal tunnel syndrome: what is attributable to work? The Montreal study.

OBJECTIVE: To estimate the fraction of carpal tunnel syndrome (CTS) that is attributable to work in the total adult population of the island of Montreal. METHODS: The population consisted of 1.1 million people 20-64 years of age, with 73.2% of men and 60.6% of women employed. The rates of first surgery for CTS were compared between occupational groups and the total adult population with the standardised incidence ratio (SIR) method. Rates of surgery for the island of Montreal were obtained from the provincial data base of payments. The occupational history was obtained from telephone interviews of a sample of surgical cases. The attributable fractions in exposed people were calculated with odds ratios (ORs) obtained from logistic regressions with non-manual workers as the control group. RESULTS: The surgical incidence of CTS was 0.9/1000 adults. SIRs for all manual workers were 1.9 (95% confidence interval (95% CI) 1.4-2.5) in men and 1.8 (95% CI 1.4-2.2) in women, and the fractions attributable to work were 76% (95% CI 47-88) and 55% (95% CI 33-69), respectively. Seven occupational groups were identified as having excess risk of surgical CTS, with fractions attributable to occupation ranging from 75% to 99%. CONCLUSION: Among manual workers on the island of Montreal, 55% of surgical CTS in women and 76% in men was attributable to work. Increased risk of surgical CTS was found in seven occupational groups.

Adult↗

[Patient education: what does the patient know, what does he want to know? Thrombosis and wound infection].

UNLABELLED: The manners of which preoperative informations are given to a patient depend on several different points. So not only the patient's education, his knowledge of medical items and his intelligence are important, but also the juridical situation and the doctor's ability to explain the situation in a way the patient is able to understand. The aim of this study was to evaluate the patient's previous knowledge about two major complications in surgery--thrombosis and wound infection. Beside this it was looked for the importance of confidence in the doctor and previous information about the operation. PATIENTS AND METHOD: 117 patients aged 16 to 87 years were tested anonymous by a standardised questionnaire. RESULTS: There is only little knowledge about the time a thrombosis develops, embolism, a wound infection and their consequences. On the other side, more than 50% of the patients were able to explain correctly the symptoms of thrombosis and the time a wound infection occurs. There was a correlation between the statement of knowledge about thrombosis (p < 0.01) and wound infection (p < 0.01) and the ability of correct explanation. Almost 90% of the patients thought that information about the operation is as important as the confidence in their surgeon. More than two third of the patients wanted to be informed about "everything" that possibly could happen. The main sources of information were neighbours, friends, the press, books and at last the doctor. CONCLUSION: There wasn't any influence of former surgeries, the awareness of complications or education on the active knowledge of the patients. Therefore we think that the way of giving explanation to a patient should help reducing fear of an uncomfortable situation and take account to the patients need for information. Thus, the patient will be able to make a real decision.

Adolescent↗

Different patterns of oxytocin, prolactin but not cortisol release during breastfeeding in women delivered by caesarean section or by the vaginal route.

The aim of this study was to find out whether the hormonal patterns of oxytocin, prolactin and cortisol differed between women delivered by emergency section or by the vaginal route and if these patterns show any relation to the duration of breastfeeding. Seventeen mothers with emergency section (C.S.) and 20 mothers with normal vaginal deliver (V.D.) were blood sampled in connection with breastfeeding on day 2 post partum for oxytocin, prolactin and cortisol. The number of oxytocin pulses as calculated with the PULSAR program occurring during the first 10 min of the breastfeeding session varied between 0 and 5. The V.D. mothers had significantly more pulses than the C.S. ones. Furthermore the C.S. women lacked a significant rise in prolactin levels at 20-30 min after the onset of breastfeeding. Logistic regression analysis revealed mode of delivery and infant's age at first breastfeed to be the most important, independent variables showing a relation to the release pattern of oxytocin on day 2. Correlations between oxytocin pulsatility on day 2 and the duration of the exclusive breastfeeding period in the V.D. group suggest that development of an early pulsatile oxytocin pattern is of importance for breastfeeding.

Adult↗

Pulsatile release of oxytocin in newborn infants.

Recently, a pulsatile, basal oxytocin blood level has been described in human adults. To investigate if such a hormone profile exists already during the neonatal period, we collected blood samples continuously with 20-s fractions for 4 min in 1-day-old infants (n = 26). Plasma oxytocin concentrations were determined by a specific radioimmunoassay. The values were further analysed by the pulse detection program PULSAR. We found that 42% of the infants presented one peak in the oxytocin level during a 4-min period. The peak constituted a 111 +/- 66% (mean +/- SD) increment of the baseline value. It is suggested that the release of oxytocin during basal conditions occurs in a pulsatile way in newborn infants and that these hormone pulses reflect fluctuations in the activity of the hypothalamic neurosecretory cells.

Female↗