Failure in developing a model for complete vascular thrombosis in the common iliac artery in the rat

The purpose of this study was to develop a model for complete arterial thrombosis proximal to the rat cremaster flap for subsequent fibrinolytic studies at the microcirculatory level. We divided 20 male Sprague-Dawley rats into four experimental groups of five animals each. We assigned each group to an established thrombosis model using crush and standard microsurgical anastomosis, crush and intimal abrasion, inverted arterial suture, and intravascular silk sutures combined with microsurgical anastomosis at the common iliac artery. Vessel patency was examined using the milking test 30, 60, 90, and 120 min after the thrombogenic insults. The model of perpendicular silk sutures and anastomosis caused complete arterial thrombosis in one animal over 120 min. The other models failed in all animals. In conclusion, the thrombogenic models used in this study are not capable of creating a reliable complete arterial thrombosis in the common iliac artery of the rat.     

Analysis of the eligibility of published economic evaluations for transfer to a given health care system. Methodological approach and application to the French health care system

CONTEXT: Economic evaluations are costly and cannot always be carried out locally. Therefore, decision-makers may wish to use studies already performed in other settings. OBJECTIVE: To define a method for assessing the eligibility of published economic evaluations for transfer to a given health care system and apply it to the french health care system in the clinical situation of adjuvant therapy for women with breast cancer. METHODS: (1) Literature search in six databases from 1982 to 1996; (2) critical appraisal of articles based on four inclusion criteria; and (3) assessment of the eligibility of the studies for transfer based on five indicators. RESULTS: We identified 26 published economic evaluations concerning adjuvant therapy in women with breast cancer. Six (23%) met all four criteria used to select studies, but none of these studies were eligible for transfer to the french health care system. The main reason was that cost data was not reported in a transparent way. CONCLUSIONS: To improve the transferability of economic evaluations, we recommend that requirements for data provision in publications be standardized and international collaboration strengthened.     

Long-term prognosis of acute low back pain in patients seen in general practice: a 1-year prospective follow-up study.

OBJECTIVES: We aimed to examine the prognosis of acute low back pain (LBP) in patients in general practice and to identify prognostic factors associated with the long-term prognosis based on information immediately available to the GP. METHOD: We conducted a prospective cohort study in general practice in Denmark. The patients were those aged 18-60 years consulting their GP due to an episode of LBP lasting less than 2 weeks. The GPs collected data regarding 34 exposure variables, including their global assessment of the likelihood of chronic LBP. Outcome variables were collected from the patients after 1, 6 and 12 months. The outcome measures were days on sick leave, and functional or complete recovery from LBP. RESULTS: In total, 503 (96%) patients were followed during the whole study period. Fifty per cent of the patients on sick leave returned to work within 8 days; after 1 year, only 2% remained on sick leave. At the 1-year follow-up, 45% of the patients continued to complain of LBP. Logistic regression analyses showed that the factors most significantly associated with poor long-term LBP outcome were (i) severity of LBP at inclusion, (ii) assessments by the GP of susceptibility to develop chronic LBP and (iii) a history of LBP having caused previous sick leave. CONCLUSIONS: LBP in general practice has a good prognosis with regard to sick leave, but a high proportion of patients continue to complain of LBP. We were not able to identify objective measures that strongly predict the prognosis of the individual LBP patient. The overall assessment by the GPs seems to be the most important predictor associated with the long-term outcome.     

Arguments and basic principles for continuous monitoring of social differences in the health of Swiss children

Zusammenfassung Ausgehend von der These, dass soziale Ungleichheit in der westlichen Gesellschaft der 90er Jahre zugenommen hat, und dass diese sich vergrössernden Unterschiede für die Volksgesundheit ein ernsthaftes Problem darstellen, legen die Autoren einen Vorschlag für die Einrichtung eines Langzeit-Monitoring-Systems im schulärztlichen Dienst der Schweiz vor. Anhand von Daten einer epidemiologischen Querschnitt-studie aus der Mitte der 80er Jahre wird gezeigt, dass die Sozialschicht-zugehörigkeit auch in einer Zeit der Hochkonjunktur eine entscheidende Determinante der Gesundheits- und Entwicklungschanchen siebenjähriger Kinder war. Je nach Art des studierten Gesundheitsproblems wurden für die Unterschiede zwischen Unter- und Oberschicht Odds-ratios zwischen 1,7 und 6,4 gefunden. Die Sozialschichtzugehörigkeit der Eltern wird auch für zukünftige Langzeit-Beobachtungen als geeigneter Indikator für die sozio-ökonomische Situation der Kinder betrachtet. Als gut standardislerbare und mit vertretbarem Aufwand regelmässig zu erhebende gesundheitliche Indikatoren werden die Anzahl somatischer Befunde sowie Störungen der motorischen und sprachlichen Entwicklung bei Schulanfängern vorgeschlagen. Das Monitoring bietet sich als rasch zu realisierendes Projekt für das sich im aufbau befindende Gesundheitsobservatorium an.

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Arguments and basic data for a continuous monitoring of social inequalities in the health of Swiss children

Summary On the basis of the thesis that social inequality has increased during the nineties in all western societies, and that this development is a reason for considerable concern with respect to public health, the authors propose the establishment of a long term monitoring system within the Swiss school health services. A re-analysis of the data obtained in a Swiss epidemiological study of seven-year-olds in the eighties demonstrates that social class was an important determinant of health and development of these children also during a period of economic boom. For various health and developmental problems odds-ratios (lower class vs. upper class) between 1.7 and 6.4 were found. Social class of the parents is considered as a reliable indicator of the socio-economic situation of children also for future long term observations. The number of significant somatic health problems as well as disorders of motor and speech development of six- or seven-year-olds are proposed as indicators of health status which can be assessed repeatedly at reasonable cost and with standardised methodology. This project could be started rather easily within the newly established Swiss Health Observatory.

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Motifs et données de base pour une observation continue de l'inégalite sociale de la santé des enfants suisses

Résumé Basé sur la thèse que l'inégalité sociale dans les sociétés industrialisées contemporaines augmente et que ceci constitue une menace importante pour la santé publique, les auteurs proposent l'installation d'un système d'observation à long terme dans les services de santé scolaires suisses. Une analyse secondaire de données obtenues lors d'une étude épidémiologique en 1985 et 1986, montre que le classe sociale de la famille était un facteur important pour la santé et le développement des enfants de sept ans déjà pendant une période de haute conjoncture. Pour les divers problèmes de santé étudiés, ont été trouvés des «odds ratios» entre classe inférieure et classe supérieure de 1.7jusqu'à 6.4. La classe sociale des parents est considéré comme indicateur valable de la situation socio-économique des enfants aussi pour un futur système d'observation. Le nombre de problèmes de santé physique et les troubles du développement moteur et de locution sont proposés comme indicateurs de santé sensibles et aptes à être mesurés régulièrement, sans coûts excessifs et d'une manière standardisée. Ce système d'observation pourrait servir de projet rapidement réalisable au nouvel Observatoire de Santé Suisse.

     

The exposure of healthy volunteers to 200 ppm 1,1,1-trichloroethane increases the concentration of proinflammatory cytokines in nasal secretions

Objectives: Irritating effects of organic solvents have usually been measured by means of questionnaires. The aim of the present study was to evaluate the sensitivity of different methods of detecting subclinical irritating effects. Methods: Twelve healthy, non-smoking students were exposed to 200 ppm and to 20 ppm 1,1,1-trichloroethane in an exposure chamber, using a crossover design. The amounts of interleukins (IL)-1β, IL-6 and IL-8 and prostaglandin E₂ (PGE₂) in nasal secretions were measured. Mucociliary transport time was determined with the saccharine test. Ciliary beat frequency of nasal epithelial cells was measured with video-interference contrast microscopy. Subjective symptoms were assessed by questionnaire. Results: Concentrations of ILs were significantly elevated after exposure to 200 ppm 1,1,1-trichloroethane (IL-1β 82.4 vs. 28.8 pg/ml (medians), P=0.003; IL-6 12.2 vs. 7.2 pg/ml, P=0.01; IL-8 549 vs. 424 pg/ml, P=0.007), whereas the other parameters remained unchanged. Conclusion: The interleukins measured proved to be sensitive indicators of irritating effects of 1,1,1-trichloroethane. The German threshold limit (MAK value) of 200 ppm 1,1,1-trichloroethane does not prevent the subclinical inflammation of nasal mucosa. Received: 3 March 1999 / Accepted: 14 June 1999     

Inflammation markers in nasal lavage, and nasal symptoms in relation to relocation to a newly painted building: a longitudinal study

Introduction: There is a need to evaluate possible health effects of ventilation improvements and emissions from new buildings, in longitudinal studies. New methods to study biological effects on the eyes and upper airways are now available. Material and methods: A longitudinal study was performed on 83 trained social workers in two offices in Uppsala, Sweden. The exposed group (n= 57) moved to a newly redecorated building nearby. Low emitting building material had been used, including a new type of solvent-free water-based paint. The control group (n= 26) worked in the same office during the study period (November 1995 to February 1996). Hygiene management was carried out in both offices, at the beginning and the end of the investigation. Tear film stability (BUT) was measured. Nasal patency was measured by acoustic rhinometry, and eosinophilic cationic protein (ECP), myeloperoxidase (MPO), lysozyme and albumin were analyzed in nasal lavage fluid (NAL). Results: The relocation resulted in an increase in the personal outdoor airflow rate from 11 to 22 l/s. Indoor concentrations of terpenes were higher in the new building, and powdering of the new linoleum floor was observed. Measurements showed low levels of volatile organic compounds (VOC), formaldehyde, carbon dioxide (CO₂), nitrogen dioxide, respirable dust, and microorganisms in the air of all buildings. The move resulted in an increased nasal patency and an increase of ECP and lysozyme in NAL, after adjusting for changes in the control group. No changes were observed for nasal or ocular symptoms. A seasonal effect, with a decrease of ECP, was observed in the control group. Conclusion: A well-ventilated office building can be redecorated without any major ocular or nasal effects, or measurable increase of indoor air pollution if low-emitting building materials are selected. In agreement with previous evidence, the improved ventilation flow may explain the increase of nasal patency. The increase of ECP and lysozyme in NAL suggested an inflammatory effect in the new building. Since this building had increased ventilation flow, increased concentrations of terpenes, and powdering from the polish on the new linoleum floor, identification of causative agents was difficult. The hygiene measures did not give any evidence that emissions from the new type of solvent-free water-based paints or building dampness were responsible for the observed nasal effects. Considering the higher emissions of VOC reported from older types of water-based latex paints and solvent-based wall paints, the new type of solvent-free water-based paint seems to be a good choice from the hygiene point of view. Received: 21 December 1998 / Accepted: 20 June 1999     

An echovirus 30 outbreak with a high meningitis attack rate among children and household members at four day-care centers

Echovirus 30 (E 30) outbreaks in defined cohorts have rarely been reported. In June 1996, an outbreak of E 30 occurred in four day-care centers (DCCs) in neighboring villages in Germany. A retrospective cohort study of DCC children, employees and household members was done to determine the extent of the outbreak and risk factors for illness. Forty-two percent (39/92) of DCC children, 13% (30/228) of their household members, 5% (1/19) of employees and 2% (1/49) of household members of employees were ill. Onsets occurred over 31 days. Thirteen percent (12/92) of DCC children had meningitis. In only one of 16 households with multiple family members ill, illness in a family member preceeded that of the DCC child. Household members of ill DCC children were 15 times more likely to report illness than those of non-ill DCC children. We conclude that this outbreak was associated with a very high incidence of meningitis, the outbreak began in the DCCs and then spread to household members, and that household members of ill children compared to those of non-ill children were much more likely to report illness.     

Computing probabilities of homozygosity by descent

A person is autozygous at a locus if the person inherits the same allele twice identical by descent along two distinct paths from the same ancestor. Autozygosity is a common cause of recessive diseases in inbred populations. Homozygosity mapping uses this fact to locate the genes that cause recessive diseases. The probability of autozygosity can be used to estimate the probability of a true positive and of a false positive in homozygosity mapping. Thompson [1994] and Guo [1997] therefore studied the problem of computing the prior, unconditional (multilocus) probability of autozygosity (MPA). I consider a different quantity: the interval probability of autozygosity (IPA). The two measures are identical in the single-locus case. IPA has two notable advantages over MPA: 1. IPA does not include the possibility of heterozygous regions between the homozygous markers. 2. IPA can be computed in time that is polynomial in the pedigree size. My polynomial-time algorithm for the single-locus case solves a problem mentioned by Guo. I implemented a program to compute the IPA. The contribution of this work is the application of basic, abstract methods from computer science to address a problem in genetics.