Blood flow distribution during elevated intraperitoneal pressure in the rat

AIM: Oliguria is seen during elevated intraperitoneal pressure, but the physiological mechanisms are not yet clarified. The purpose of the present study was to investigate the changes in renal function, cardiac output and distribution of systemic blood flow (BF) that occur in connection with an elevation of intra-abdominal pressure (IAP) in a rat model by isotope-labelled microsphere technique. METHODS: A 5 or 10 mmHg IAP was created by CO2 insufflation and maintained for 90 min in anaesthetized and mechanically ventilated rats. Rats with normal IAP served as controls. Blood flow and cardiac output measurements by injection of isotope-labelled microspheres were conducted at three time points. Acid-base balance, urine output, glomerular filtration rate (GFR) and urinary excretion products were also followed. RESULTS: Glomerular filtration rate decreased [0.7-0.1 mL min(-1) g(-1) kidney weight (KW)] with elevated IAP, as did urine output (8.5-0.6 microL min(-1) g(-1) KW). Dramatic decreases were seen in renal excretion of sodium (by 97%), potassium (by 94%) and osmotic active substances (by 93%). Cardiac output was diminished by 54% at 5 mmHg and by 65% at 10 mmHg intraperitoneal pressure and systemic vascular resistance (SVR) was elevated threefold. CONCLUSION: Cardiac output, measured by microsphere technique, decreased during elevated intraperitoneal pressure by CO2 in anaesthetized rats, while SVR was elevated and renal excretory functions were decreased to a large extent.     

Distribution of the common tick, Ixodes ricinus (Acari: Ixodidae), in different vegetation types in southern Sweden

The aim of this study was to investigate whether differences in Ixodes ricinus (L.) nymphal relative density exist among different vegetation types in southern Sweden. Nymphal I. ricinus were sampled in southeastern Scania in southern Sweden during June-August 1997. A total of 110-180 25-m2 samples were taken by blanket-dragging from each of nine different vegetation types. There was a highly significant difference in nymphal abundance between the open areas as one group and the forested areas as another group (P < 0.0001). Vegetation types that differed significantly in median nymphal abundance from all other vegetation types were pine forest (16 nymphs/100 m2) and beech forest (40 nymphs/100 m2). No significant differences in median nymphal density were revealed among mixed deciduous forest, alder forest, oak forest, and hazel forest (28-32 nymphs/100 m2), or among dry meadow, meadow, and heath (0 nymphs/100 m2). Forestation of open areas is likely to lead to increased I. ricinus abundance and disease risk.     

Time for a "vision zero" concerning premature death from ischaemic heart disease?

OBJECTIVE: To study the trend in premature mortality (before 75 years of age) from ischaemic heart disease (IHD) in a Swedish primary health care district compared to communities of similar demographic situation and all Sweden. DESIGN: Mortality from IHD in men and women was compared between the community of Habo and other Swedish communities of similar size and all Sweden for the period 1984-96. SETTING: The community of Habo in Sweden with about 9600 inhabitants. INTERVENTION: Intensified efforts by the local primary health care organisation, in co-operation with the community, in respect of primary and secondary cardiovascular prevention since the beginning of the 1980s. RESULTS: Mortality from IHD has decreased significantly both in Habo and in Sweden during these years. The decrease has been more prominent in Habo than in Sweden as a whole and other Swedish communities of similar demographic situation. CONCLUSION: With increased and purposeful efforts in primary and secondary prevention, in co-operation between the community and primary health care, it is possible to substantially decrease mortality from IHD in the community.     

Ambiguity leads to uncertainty: ambiguous demands to blood donors

Blood donors must respond to standard control questions and comply to certain demands before donating blood, to exclude possible recent contamination. This study investigates whether donors had adequate knowledge about 'the immunological window period', and whether the standard questionnaire in use was understandable and clear. It was found that nearly 40% of the donors had inadequate knowledge about 'the immunological window period' and that 10-40% of the donors would respond in various ways to different interpretations of the formulations of the questionnaire, indicating that the questionnaire was ambiguous. It was concluded that these factors could increase the risk of donating on wrong conditions. Demands and control questions posed to donors must be void of ambiguous formulations and take proper account of actual human sexual behaviours and life styles. Finally, it is suggested that blood banks must offer practical solutions (such as a 'fake donation') for temporarily rejected donors in order to respect their private integrity.     

Investments in social capital--implications of social interactions for the production of health

This paper develops a theoretical model of the family as producer of health- and social capital. There are both direct and indirect returns on the production and accumulation of health- and social capital. Direct returns (the consumption motives) result since health and social capital both enhance individual welfare per se. Indirect returns (the investment motives) result since health capital increases the amount of productive time, and social capital improves the efficiency of the production technology used for producing health capital. The main prediction of the theoretical model is that the amount of social capital is positively related to the level of health; individuals with high levels of social capital are healthier than individuals with lower levels of social capital, ceteris paribus. An empirical model is estimated, using a set of individual panel data from three different time periods in Sweden. We find that social capital is positively related to the level of health capital, which supports the theoretical model. Further, we find that the level of social capital (1) declines with age, (2) is lower for those married or cohabiting, and (3) is lower for men than for women.     

Airborne infectious diseases during infancy and mortality in later life in southern Sweden, 1766-1894

BACKGROUND: The importance of early life conditions and current conditions for mortality in later life was assessed using historical data from four rural parishes in southern Sweden. Both demographic and economic data are valid. METHODS: Longitudinal demographic and socioeconomic data for individuals and household socioeconomic data from parish registers were combined with local area data on food costs and disease load using a Cox regression framework to analyse the 55-80 year age group mortality (number of deaths = 1398). RESULTS: In a previous paper, the disease load experienced during the birth year, measured as the infant mortality rate, was strongly associated with old-age mortality, particularly the outcome of airborne infectious diseases. In the present paper, this impact persisted after controlling for variations in food prices during pregnancy and the birth year, and the disease load on mothers during pregnancy. The impact on mortality in later life stems from both the short-term cycles and the long-term decline in infant mortality. An asymmetrical effect and strong threshold effects were found for the cycles. Years with very high infant mortality, dominated by smallpox and whooping cough, had a strong impact, while modest changes had almost no impact at all. The effects of the disease load during the year of birth were particularly strong for children born during the winter and summer. Children severely exposed to airborne infectious diseases during their birth year had a much higher risk of dying of airborne infectious diseases in their old age. CONCLUSIONS: This study suggests that exposure to airborne infectious diseases during the first year of life increases mortality at ages 55-80.     

Social capital and the miniaturization of community among daily and intermittent smokers: a population-based study

BACKGROUND: The impact of social participation, trust, and the miniaturization of community on daily and intermittent smoking was investigated. METHODS: The 2000 public health survey in Scania is a cross-sectional study. A total of 13,715 persons answered a postal questionnaire, which represents 59% of the random sample. A logistic regression model was used to investigate the association between the social capital variables and daily and intermittent smoking. The multivariate analysis was performed by using a logistic regression model to investigate the importance of possible confounders (age, country of origin, education, and snuff consumption) on the differences in daily and intermittent smoking between high versus low social participation, trust, and their four combination categories. The differences in the prevalences of the 13 social participation subitems between the high social capital and miniaturization of community categories were compared by t tests. RESULTS: Daily smoking is negatively associated with both social participation and trust, while intermittent smoking is positively associated with social participation and negatively associated with trust. This latter combination, named "the miniaturization of community," is an indirect measure of the ideologically and culturally increasingly narrow forms of social participation that excludes generalised trust to other people. Study circles, meetings of organisations, theatre/cinema, arts exhibition, and gathering of relatives are more prevalent in the high social capital category, while visit(s) to night club/entertainment is more prevalent in the miniaturization of community category. CONCLUSIONS: Low social capital is associated with daily smoking. "The miniaturization of community," i.e., high social participation and low trust, is significantly associated with intermittent smoking. The results have direct implications for smoking prevention strategies.     

C-reactive protein levels following standard neurosurgical procedures

Summary ¶Background. The aim of the present study was to establish the magnitude and time-course of C-reactive protein increases following routine neurosurgical procedures in the absence of clinical and laboratory signs of infection. Method. C-reactive protein levels were studied daily following ventriculo-peritoneal shunt implantation, anterior cervical fusion, vestibular schwannoma operation, supratentorial glioma surgery, endovascular intracranial aneurysm treatment and open cerebral aneurysm surgery. Findings. The magnitude of the C-reactive protein increase depended on the extent of surgical trauma and peak-levels were recorded between postoperative day one and four after which the levels tapered off. Interpretation. Increases occurring after the fourth postoperative day are likely to be caused by complications of surgery, e.g. infection.Published online July 23, 2003     

Prevalence of sindbis virus neutralizing antibodies among Swedish passerines indicates that thrushes are the main amplifying hosts

The Sindbis virus uses birds as vertebrate hosts in the summer amplification cycle, and the virus is transmitted by ornithophilic Culex species. Previous field and experimental studies have shown that mainly passerine birds are involved in the amplification. To delineate the pattern of Sindbis virus infections among passerines, we collected and sampled birds for blood at five study sites located in northern, central, and southern Sweden. All study sites were lowland forested wetlands and humid forests. The blood samples were assayed for Sindbis neutralizing antibodies, and we tested if the prevalence of Sindbis antibodies varied in relation to bird characteristics (i.e., species, body-mass, sex, and age), and environmental factors (i.e., year, month, and location). We found that Sindbis virus infections occurred in almost all passerine species sampled, but that the infection prevalence was unequally distributed among species. The fieldfare, the redwing, and the songthrush each had significantly higher prevalence than the average for all species. Large passerine species had higher infection prevalence than small species. The infection was less prevalent in hatching-year birds than in older birds during June and July, but not in August. Males and females had the same infection prevalence. The prevalence of Sindbis antibodies was higher in central than in southern Sweden, which coincided with a higher proportion of fieldfare-redwing-songthrush samples in the central region of the country. Thus, it is possible that regional and annual variations in the prevalence of Sindbis antibodies in Swedish passerine species depend on the number of fieldfares, redwings, and songthrushes available for feeding by vector mosquitoes.     

Plasma oxytocin and cortisol concentrations in dairy cows in relation to feeding duration and rumen fill

The aim of this study was to investigate if the release of oxytocin and cortisol were different depending on levels of oral manipulation with feed or rumen fill in dairy cows. Blood samples and behavior of 12 rumen-fistulated cows were analyzed in 2 consecutive years during morning and afternoon periods when the cows were subjected to either (A) long duration of oral manipulation of feed with low rumen fill or (B) short duration of oral manipulation of feed but with filled rumen. The response areas under the curve for oxytocin in both years were larger in A than in B in the afternoons. There were peaks in oxytocin release at milking in the afternoon in both treatments. In B, the oxytocin concentration was higher after than before feeding, higher in B than in A after the non-oral rumen filling, and higher in B after than before the non-oral rumen filling in Year 1. The level of cortisol was higher in B than in A in the morning, lower in both treatments before than after milking in the afternoon, and there was a tendency for the cortisol level to be higher in A than in B after oral feeding. The B cows spent a shorter time eating and the A cows spent a shorter time ruminating. This study indicates that a long duration of oral manipulation of feed in cows, may, per se be linked to higher oxytocin but lower cortisol levels, compared with shorter oral feeding time and filled rumen.