Cardiovascular Adjustments to Gravitational Stress

The effects of gravity on the cardiovascular system must be taken into account whenever a hemodynamic assessment is made. All intravascular pressure have a gravity-dependent hydrostatic component. The interaction between the gravitational field, the position of the body, and the functional characteristics of the blood vessels determines the distribution of intravascular volume. In turn this distribution largely determines cardiac pump function. Multiple control mechanisms are activated to preserve optimal tissue perfusion when the magnitude of the gravitational field or its direction relative to the body changes. Humans are particularly sensitive to such changes because of the combination of their normally erect posture and the large body mass and blood volume below the level of the heart. Current aerospace technology also exposes human subjects to extreme variations in the gravitational forces that range from zero during space travel to as much an nine-times normal during operation of high-performance military aircraft. This chapter therefore emphasizes human physiology

Cardiovascular effects of variations in habitual levels of physical activity

Mechanisms involved in human cardiovascular adaption to stress, particularly adaption to different levels of physical activity are determined along with quantitative noninvasive methods for evaluation of cardiovascular function during stess in normal subjects and in individuals with latent or manifest cardiovascular disease. Results are summarized

Fast convergence to equilibrium for long-chain polymer melts using a MD/continuum hybrid method

Effective and fast convergence toward an equilibrium state for long-chain polymer melts is realized by a hybrid method coupling molecular dynamics and the elastic continuum. The required simulation time to achieve the equilibrium state is reduced drastically compared with conventional equilibration methods. The polymers move on a wide range of the energy landscape due to large-scale fluctuation generated by the elastic continuum. A variety of chain structures is generated in the polymer melt which results in the fast convergence to the equilibrium state.Comment: 13 page

ASO Author Reflections : Registry-Based Analysis of Radiation-Associated Angiosarcoma of the Breast Provides Unbiased Insights into this Disease

Non peer reviewe

Behaviour management problems in Finnish children with operated congenital heart disease : a practice-based study

Purpose This retrospective, practice-based study investigates behaviour management problems (BMPs) in dental care among Finnish children with operated congenital heart disease (CHD). Methods All the heart-operated children born between the years 1997 and 1999 were identified in the national ProCardio database (n = 570). Primary dental care records were requested from this population and were eventually received from 211 patients. Information on gender, diagnosis, number of heart operations and perioperative care were collected from the ProCardio database, and the CHDs were categorised as shunting/stenotic/complex/other defects. Data on BMP/dental fear, oral conscious sedation, dental general anaesthesia (DGA) and past and present caries indices at 6, 12 and 15 years (d/D, dmft/DMFT) were assessed. Results Notes on behaviour management problems or dental fear were found in 19% of the study population. BMPs in dental care were more frequent among boys. Children with re-operations, longer post-operative intensive care stay and hospitalisation, and complications had not more BMP than others. Those children diagnosed with syndromes had more BMP often than the rest. Past and present caries experience were significantly associated with BMP, need of oral conscious sedation and DGA. Oral conscious sedation, nitrogen oxide sedation and dental general anaesthesia were used in 17/211, 2/221 and 24/211 CHD patients, respectively. Conclusion Dental caries remains a main factor associated with BMP in the CHD population. Need for oral conscious sedation and DGA were rather common. To maintain a good oral health and to avoid development of BMP, CHD children benefit from focus in health promotion and preventive care.Peer reviewe

Sulfatide in health and disease. The evaluation of sulfatide in cerebrospinal fluid as a possible biomarker for neurodegeneration

Sulfatide (3-O-sulfogalactosylceramide, SM4) is a glycosphingolipid, highly multifunctional and particularly enriched in the myelin sheath of neurons. The role of sulfatide has been implicated in various biological fields such as the nervous system, immune system, host-pathogen recognition and infection, beta cell function and haemostasis/thrombosis. Thus, alterations in sulfatide metabolism and production are associated with several human diseases such as neurological and immunological disorders and cancers. The unique lipid-rich composition of myelin reflects the importance of lipids in this specific membrane structure. Sulfatide has been shown to be involved in the regulation of oligodendrocyte differentiation and in the maintenance of the myelin sheath by influencing membrane dynamics involving sorting and lateral assembly of myelin proteins as well as ion channels. Sulfatide is furthermore essential for proper formation of the axo-glial junctions at the paranode together with axonal glycosphingolipids. Alterations in sulfatide metabolism are suggested to contribute to myelin deterioration as well as synaptic dysfunction, neurological decline and inflammation observed in different conditions associated with myelin pathology (mouse models and human disorders). Body fluid biomarkers are of importance for clinical diagnostics as well as for patient stratification in clinical trials and treatment monitoring. Cerebrospinal fluid (CSF) is commonly used as an indirect measure of brain metabolism and analysis of CSF sulfatide might provide information regarding whether the lipid disruption observed in neurodegenerative disorders is reflected in this body fluid. In this review, we evaluate the diagnostic utility of CSF sulfatide as a biomarker for neurodegenerative disorders associated with dysmyelination/demyelination by summarising the current literature on this topic. We can conclude that neither CSF sulfatide levels nor individual sulfatide species consistently reflect the lipid disruption observed in many of the demyelinating disorders. One exception is the lysosomal storage disorder metachromatic leukodystrophy, possibly due to the genetically determined accumulation of non-metabolised sulfatide. We also discuss possible explanations as to why myelin pathology in brain tissue is poorly reflected by the CSF sulfatide concentration. The previous suggestion that CSF sulfatide is a marker of myelin damage has thereby been challenged by more recent studies using more sophisticated laboratory techniques for sulfatide analysis as well as improved sample selection criteria due to increased knowledge on disease pathology

Dental caries and attendance to dental care in Finnish children with operated congenital heart disease. A practice based follow-up study

Purpose Oral health of children with congenital heart disease (CHD) is of utmost importance. This study aimed to investigate the prevalence of dental caries and attendance to dental care in Finnish heart-operated CHD patients born in 1997-1999. Methods The cohort of children born in 1997-1999 was selected using a national register on all heart-operated children in Finland. Gender, general health problems, diagnosis, type of the heart defect (shunting, stenotic and complex defects), and number of operations were available and included in the analyses. Dental records from primary health care were collected from municipalities with their permission. The data comprised of the number of dental examinations and data on caries status (dt, DT, dmft, DMFT) at the age of 7 (grade 1), 11 (grade 5) and 15 (grade 8) years and at the most recent examination. The control group consisted of dental data on patients born in 1997-1999 provided by the City of Oulu, Finland (n = 3356). Results Oral patient records of 215/570 children were obtained. The difference between the defect types was statistically significant both for DT (p = 0.046) and DMFT (p = 0.009) at the age of 15 (grade 8). The prevalence of caries did not differ between the study population and the controls. High present and past caries experiences were not associated with higher number of visits to oral health care, especially to oral hygienist, or with oral health promotion. National obligations concerning dental visits were not implemented in all municipalities. Conclusion There seems to be a need for oral health promotion and preventive means implemented by oral hygienists among those with CHD.Peer reviewe

Radiation to supraclavicular and internal mammary lymph nodes in breast cancer increases the risk of stroke

The aim of this study was to assess whether adjuvant treatment of breast cancer (BC) affects the risk of stroke, and to explore radiation targets and fraction doses regarding risk and location of stroke. In a Swedish BC cohort diagnosed during 1970–2003, we carried out a nested case–control study of stroke after BC, with relevant details extracted from medical records. The odds ratio (OR) for radiotherapy (RT) vs that of no RT did not differ between cases and controls (OR=0.85; confidence interval, CI=0.6–1.3). Radiotherapy to internal mammary chain (IMC) and supraclavicular (SCL) lymph nodes vs that of no RT was associated with a higher, although not statistically significant, risk of stroke (OR=1.3; CI=0.8–2.2). In a pooled analysis, RT to IMC and SCL vs the pooled group of no RT and RT to breast/chest wall/axilla (but not IMC and SCL), showed a significant increase of stroke (OR=1.8; CI=1.1–2.8). There were no associations between cancer laterality, targets of RT, and location of stroke. The radiation targets, IMC and SCL, showed a statistically significant trend for an increased risk of stroke with daily fraction dose. Our finding of a target-specific increased risk of stroke and a dose-response relationship for daily fraction dose, indicate that there may be a causal link between RT to the IMC and SCL and risk of stroke