Aerosolsammansättning i ett renluftsområde

Aerosolsammansättningen i ett renluftsområde i Mellansverige (Velen) har studerats under en årscykel. Aerosolpartiklarna har uppdelats efter aerodynamisk storlek i 7 fraktioner. Varje fraktion från 113 provtagningstillfällen har analyserats m a p svavel och tungmetaller m h a partikelinducerad röntgenstrålning s k PIXE-analys. Resultaten påvisar variationer i ämneskoncentrationer mellan enskilda mättillfällen omspännande två storleks ordningar. Årsmedelkoncentrationerna ligger på samma nivå som i rural miljö i Bolivia, Canada, Norge och Schweiz. Jämfört med motsvarande koncentrationer i urban miljö (Köpenhamn m fl storstäder) är tungmetallkoncentrationerna en till två storleksordningar (svavelkoncentrationen endast en faktor tre) lägre i Velen. Inga påtagliga säsongsvariationer kunder spåras varken för antropogent eller naturligt bildade ämnen. Klassificering av mättillfällena efter luftmassans historia kunde förklara mycket av de stora koncentrationsvariationerna. Grundämneskoncentrationerna var mellan en faktor 2 och 10 högre i luftmassor som kom från den europeiska kontinenten eller Storbritannien jämfört med de som kom norrifrån. Lägst var koncentrationerna i luftmassor som kom från Nordatlanten eller Norska Havet. Svavelkoncentrationerna visade störst beroende av luftmassans historia

Limited Spread of Penicillin-Nonsusceptible Pneumococci, Skåne County, Sweden

In response to increasing frequencies of penicillin-nonsusceptible pneumococci (PNSP), for which the MIC of penicillin was >0.12 mg/L, in Skåne County, southern Sweden, national recommendations were initiated in 1995 to limit the spread of pneumococci with high MICs (>0.5 mg/L) of penicillin (PRP), especially among children of preschool age. Traditional communicable disease control measures were combined with actions against inappropriate antimicrobial drug use. During the first 6 years that these recommendations were applied in Skåne County, the average frequency of penicillin-resistant pneumococci has been stable at ≈2.6%, as has the average PNSP frequency (7.4%). However, PNSP have been unevenly distributed in the county, with the highest frequencies in the southwest. Simultaneously, the rate of antimicrobial drug use for children <6 years of age was reduced by 20%. Thus the spread of PNSP between and within the municipalities in the county has been limited

Epidemiologic and molecular investigation of outbreaks of hepatitis C virus infection on a pediatric oncology service

BACKGROUND: Despite screening of blood donors, hepatitis C virus (HCV) infection can occur in patients who receive multiple transfusions. OBJECTIVE: To clarify mechanisms of nosocomial transmission of HCV. DESIGN: Epidemiologic and molecular analyses of hepatitis C outbreaks. SETTING: Pediatric oncology ward. PATIENTS: Children with cancer. MEASUREMENTS: Epidemiologic analysis, HCV RNA detection, genotyping, and hypervariable region 1 (HVR1) sequencing. RESULTS: Ten cases of infection with acute HCV genotype 3a occurred between 1990 and 1993. Sequencing of HVR1 revealed three related strains. Despite an overhaul of hygiene procedures, a patient infected with genotype 1b generated nine subsequent infected patients in 1994. Several patients had high virus titers and strongly delayed anti-HCV antibody responses. All had permanent intravenous catheters. Multidose vials used for flushing or treatment had probably been contaminated during periods of overlapping treatment. CONCLUSIONS: Contamination of multidose vials was the most likely mode of HCV transmission; therefore, use of such vials should be restricted. Rigorous adherence to hygiene routines remains essential to preventing transmission of bloodborne infections

The diffusion model and the social-hierarchical process of change

This article presents some critical comments on the use of Rogers' innovation-diffusion model, which is often referred to in health promotion research as an explanation of how behavioural changes occur over time. The analytical focus is on the belief that there is a social pattern in the process of diffusion, so that higher socioeconomic groups lead the way in adopting ‘preventive innovations’, and lower socio-economic groups subsequently follow as ‘late adopters’. This view of the diffusion process—closely akin to the notion of ‘imitation/social role modelling’—will be reviewed here within a sociological framework

Multiple HIV-1 introductions into the Swedish intravenous drug user population

In 2001, an increase of HIV-1 diagnoses among intravenous drug users (IVDU) was reported in Sweden. In nearby countries, Finland, Russia and the Baltic states, recent outbreaks had been described. Since there was a concern that these outbreaks would carry over to Sweden a study was initiated to determine the factors leading to the Swedish increase of HIV-1 diagnosed IVDUs. HIV-1 env V3 sequences were obtained from 97 patients enrolled in ongoing epidemiological studies encompassing the years 1987-2004 with a focus on 2001-2002. The sequences were used for maximum likelihood and Bayesian inference of the molecular epidemiology. Among the virus spreading in 2001-2002, we found that four different subtypes/CRFs were present in the Swedish IVDU population (A, B, CRF01_AE and CRF06_cpx). Subtype B constituted 85% of the infections, established by 12 independent introductions into the IVDU population. The worrisome increase in 2001 was mainly not a result of import of the outbreaks in nearby countries, but rather a higher detection rate of secondary cases due to efficient epidemiological tracing of the generally slow spread of established forms of subtype B in the IVDU community. However, a few of the non-subtype B cases were linked to the outbreaks in Finland, Estonia and Latvia. Because HIV-1 outbreaks can easily be exported from one country to another amongst IVDUs, this prompts continued surveillance in the Baltic Sea Region. Published by Elsevier B.V

Pressure Effects in the Spinal Canal During Whiplash Extension Motion - A Possible Cause of Injury to the Cervical Spinal Ganglia

impact-velocities

An economic and sociological interpretation of social differnces in health-related behaviour: An encounter as a guide to social epidemoiology

We argue that the group-centred analyses of social epidemiology should follow from theoretical considerations that take the situation of the individual as their natural starting point. In a tentative dialogue between economics and sociology, we develop a framework for the analysis of health-related behaviour. Such behaviour is modelled as a process of decision-making at the individual level. Within economics, we draw specifically on the demand-for-health literature and the new institutional economics. Within sociology, Bourdieu's habitus theory is presented in combination with a macro-structural approach where the focus is on the process of individualization. The relationship between these different approaches to health-related behaviour and their implications is discussed. We find that the encounter between different sciences provides valuable insights for future work in the socio-epidemiological tradition

Nervenzellsch\ue4den bei Schleudertraumen. Tierexperimentelle Untersuchungen

Die mechanische Belastung der Halswirbels\ue4ule (HWS) bei Autounf\ue4llen verursacht ofteine Reihe von Halsverletzungen, die unterdem Begriff Schleudertrauma zusammengefa\ufbt werden. Mehrere dieser Symptomek\uf6nnen m\uf6glicherweise durch Verletzungenim Bereich der Nervenwurzeln der HWS erkl\ue4rt werden. Die Hypothese wurde aufgestellt,da\ufb w\ue4hrend der Extensions- und Flexionsbewegungendes Halses, aufgrund vonh\ue4modynamischen Auswirkungen, \ubenderungendes inneren Volumens des Halswirbelkanalskurzzeitige Druckver\ue4nderungenim ZNS verursachen und da\ufb dadurch Gewebesch\ue4den durch die mechanische Belastungder Nervenwurzel entstehen. Um dieHypothese zu \ufcberpr\ufcfen, wurden an\ue4sthesierteSchweine einem experimentellenSchleudertrauma mit Extensions-, FlexionsundSeitneigungsbewegungen ausgesetzt.Die traumatische Belastung wurde unterhalbeiner Stufe gehalten, bei der eine Halswirbelfrakturstattfinden k\uf6nnte. W\ue4hrend derBelastung wurde der Pulsdruck im Halswirbelkanalgemessen. In diesem Zusammenhangergaben sich Hinweise einer Dysfunktionder Zellmembran bei Nervenzellk\uf6rpernder Spinalganglien. Die ganglion\ue4ren Verletzungenk\uf6nnen m\uf6glicherweise einige dermit Weichteilverletzungen des Halses nachAutounf\ue4llen einhergehenden Symptomeerkl\ue4ren. Um die Situation bei einem Auffahrunfallzu simulieren, wurde der Kopf desSchweines r\ufcckw\ue4rts vom Torso weggezogen.Dabei wurde festgestellt, da\ufb die ganglion\ue4ren Verletzungen zu einem sehr fr\ufchenZeitpunkt w\ue4hrend der Halsbewegungenstattfinden und zwar in der Phase, in der dieBewegung von der Retraktion zur Extensionwechselt. Bei einer \ue4hnlichen, jedoch statischenBelastung des Halses wurden keineganglion\ue4ren Verletzungen bei den Schweinenfestgestellt. Dies ist ein Hinweis darauf,da\ufb diese Verletzungen durch dynamischeFaktoren verursacht werden und bietet somitweitere Unterst\ufctzung f\ufcr die Druckhypothese.Auf der Basis eines theoretischen Modellswurden Kriterien f\ufcr Halsverletzungen(neck injury criterion = NIC) entwickelt. Esweist darauf hin, da\ufb das Risiko von ganglion\ue4ren Verletzungen am Punkt der maximalenHalsretraktion durch die unterschiedlichehorizontale Beschleunigung und Geschwindigkeitzwischen Kopf und oberemTorso bestimmt wird