8 research outputs found
Loss of muscle oxidative capacity after an extreme endurance race : the Paris-Dakar foot race.
No full textWe measured changes in maximal oxygen uptake capacity (V̇O2max), ventilation, heart rate, plasma lactate and speed at the end of an incremental exercise test as a consequence of a relay foot race from Paris to Daltar in 6 subjects. Additionally, anthropometric measurements were taken and muscle biopsies from M. vastus lateralis were obtained before and after the race. The latter were analyzed with morphometric methods for fiber size, capillarity and muscle ultrastructural composition. Weight specific V̇O2max was significantly reduced from 62.4 to 60.5 ml/min . kg after the race while absolute V̇O2max and the other endurance related functional variables remained unchanged. Body fat, thigh cross-sectional area and thigh volume showed tendential reduction immediately after the race but regained pre-race values within a few days. Fiber size and capillarity were not affected by the race. Volume density of total mitochondria was significantly reduced from 6.98 to 4.89% of fiber volume. Both subsarcolemmal and interfibrillar mitochondria were significantly reduced by 59 and 21%, respectively. The volume density of satellite cell was increased about three-fold whereas the content of lipofuscin remained constant. It is concluded that extreme endurance events such as a multi-stage relay race may induce a considerable loss of oxidative capacity of skeletal muscle tissue
Loss of muscle oxidative rapacity after an extreme endurance run: The Paris-Dakar foot-race
No full textWe measured changes in maximal oxygen uptake capacity (V̇O2max), ventilation, heart rate, plasma lactate and speed at the end of an incremental exercise test as a consequence of a relay foot race from Paris to Daltar in 6 subjects. Additionally, anthropometric measurements were taken and muscle biopsies from M. vastus lateralis were obtained before and after the race. The latter were analyzed with morphometric methods for fiber size, capillarity and muscle ultrastructural composition. Weight specific V̇O2max was significantly reduced from 62.4 to 60.5 ml/min . kg after the race while absolute V̇O2max and the other endurance related functional variables remained unchanged. Body fat, thigh cross-sectional area and thigh volume showed tendential reduction immediately after the race but regained pre-race values within a few days. Fiber size and capillarity were not affected by the race. Volume density of total mitochondria was significantly reduced from 6.98 to 4.89% of fiber volume. Both subsarcolemmal and interfibrillar mitochondria were significantly reduced by 59 and 21%, respectively. The volume density of satellite cell was increased about three-fold whereas the content of lipofuscin remained constant. It is concluded that extreme endurance events such as a multi-stage relay race may induce a considerable loss of oxidative capacity of skeletal muscle tissue
Auswirkungen von depressiven Störungen auf objektive Lebensqualitätsbereiche : Effects of Depressive Disorders on Objective Life Quality Criteria
No full textOBJECTIVE: This study examines the extent to which depression affects specific objective life quality parameters. The respective life quality parameters were investigated on a long-term basis and concern the social and material resources of those persons surveyed. METHOD: The database used for statistical evaluations originates from the longitudinal survey "Zurich Study" initiated in 1979. In this work the evaluations are limited to those persons who participated in all six structured interviews which took place between 1979 and 1999 (278 of initially 591 Persons). The effects of depression on the objective parameters of life quality were analyzed by linear and logistical regressions. RESULTS: According to this study, people suffering from depression show disadvantages regarding their living situation and their civil status. Among them one finds increased divorce and separation quota and they live more frequently alone than persons without depressive disorders. CONCLUSIONS: The findings refer to possible social withdrawal tendencies among people suffering from depression. Social withdrawal tendencies should be counteracted as far as possible by upholding or developing a network of firm contacts and relationships. Special attention should be paid in the therapy of depression patients to working out strategies for solving marriage crises or relationship conflicts
Efficient T cell repertoire selection in tetraparental chimeric mice independent of thymic epithelial MHC
No full textNonthymic epithelial cells were compared with thymic epithelial cells for their role in T cell repertoire selection. Tetraparental aggregation chimeras were generated from T and B cell-deficient mice (H-2(d) SCID or H-2(b) Rag-/-) and thymus-deficient nude mice (H-2(b) or H-2(d)). These tetraparental mice showed primary protective CD8(+) T cell responses, after lymphocytic choriomeningitis virus infection, that were peptide-specifically restricted to either thymic or nonthymic epithelial MHC at comparable levels. These chimeras also mounted neutralizing IgG responses dependent on cognate CD4(+) T helper cell activity restricted to nonthymic epithelial MHC. Therefore, in contrast to earlier results with irradiation or thymus chimeras, these relatively undisturbed tetraparental mice reveal that the MHC of nonthymic epithelial cells efficiently selects a functional T cell repertoire.</br
Dissection of the asynchronous transport of intestinal microvillar hydrolases to the cell surface
No full textNovel subcellular fractionation procedures and pulse-chase techniques were used to study the intracellular transport of the microvillar membrane hydrolases sucrase-isomaltase and dipeptidylpeptidase IV in the differentiated colon adenocarcinoma cell line Caco-2. The overall rate of transport to the cell surface was two fold faster for dipeptidylpeptidase IV than for sucrase-isomaltase, while no significant differences were observed in transport rates from the site of complex glycosylation to the brush border. The delayed arrival of sucrase-isomaltase in the compartment where complex glycosylation occurs was only in part due to exit from the endoplasmic reticulum. A major slow-down could be ascribed to maturation in and transit of this enzyme through the Golgi apparatus. These results suggest that the observed asynchronism is due to more than one rate-limiting step along the rough endoplasmic reticulum to trans-Golgi pathway
Therapeutic and toxic blood concentrations of nearly 1,000 drugs and other xenobiotics
No full textIntroduction: In order to assess the significance of drug levels measured in intensive care medicine, clinical and forensic toxicology, as well as for therapeutic drug monitoring, it is essential that a comprehensive collection of data is readily available. Therefore, it makes sense to offer a carefully referenced compilation of therapeutic and toxic plasma concentration ranges, as well as half-lives, of a large number of drugs and other xenobiotics for quick and comprehensive information.
Methods: Data have been abstracted from original papers and text books, as well as from previous compilations, and have been completed with data collected in our own forensic and clinical toxicology laboratory. The data presented in the table and corresponding annotations have been developed over the past 20 years and longer. A previous compilation has been completely revised and updated. In addition, more than 170 substances, especially drugs that have been introduced to the market since 2003 as well as illegal drugs, which became known to cause intoxications, were added. All data were carefully referenced and more than 200 new references were included. Moreover, the annotations providing details were completely revised and more than 100 annotations were added.
Results: For nearly 1,000 drugs and other xenobiotics, therapeutic ("normal") and, if data were available, toxic and comatose-fatal blood-plasma concentrations and elimination half-lives were compiled in a table.
Conclusions: In case of intoxications, the concentration of the ingested substances and/or metabolites in blood plasma better predicts the clinical severity of the case when compared to the assumed amount and time of ingestion. Comparing and contrasting the clinical case against the data provided, including the half-life, may support the decision for or against further intensive care. In addition, the data provided are useful for the therapeutic monitoring of pharmacotherapies, to facilitate the diagnostic assessment and monitoring of acute and chronic intoxications, and to support forensic and clinical expert opinions
The Distribution of opiates, cocaine and their metabolites in skeletal muscle tissue and vitreous humour as an aid to post-mortem toxicological interpretation.
No full textPost-mortem blood drug concentrations vary greatly and as a consequence of post-mortem change and redistribution may not reflect the concentration at the time of death. Tissues that are located away from central drug reservoirs and that lack esterase activity, e.g. muscle and vitreous humour (VH), have the potential to provide more reliable post-mortem toxicological specimens. In the absence of a blood sample the toxicologist may have to rely on such tissues yet few studies have been undertaken to examine the relationship between drugs in blood and less conventional tissues at the time of death.
The purpose of this study was to investigate the distribution of opiates (heroin specific compounds) and cocaine and their respective metabolites in VH and muscle with a view to elucidating the interpretive value of these tissues. Analytical methods were developed and validated to measure drug concentrations in blood, VH and muscle, including throughout the rectus femoris thigh muscle, in cases of drug related death. To assist with interpretation of drug concentrations measured in post-mortem tissues the in vitro stability of cocaine and 6-acetylmorphine (6AM) was examined during the putrefactive process and under different storage conditions. Relationships between blood and tissue drug concentrations were assessed in relation to case circumstances with particular focus on the approximation of survival time.
In contrast to a report previously published in the literature, this study found the concentration of cocaine, and its metabolites, benzoylecgonine (BZE) and cocaethylene (COET), to be uniformly distributed throughout the thigh muscle (n = 7). Concentrations of cocaine in muscle were markedly higher than in blood and correlated well with the blood. The stability of cocaine in muscle tissue was found to greatly exceed that in blood and VH. These preliminary results also indicated that the cocaine to BZE ratio measured in both muscle and VH may be of value in the assessment of survival time. These findings promote the use of muscle as a toxicological specimen for cocaine determinations. Further work is required to validate these findings and to examine the distribution of opiates in muscle, which could not be assessed in this study. The relationship between femoral blood and vitreous humour morphine concentration (n = 70) was found to be dependent on survival time and possibly influenced by accumulation of morphine in the VH. These findings demonstrate that the concentration of morphine in blood cannot be inferred from that measured in the VH. The VH provided a useful adjunct to interpretation owing to the prolonged detection of 6AM in this matrix. The addition of 1.5% sodium fluoride to VH was found to be essential for 6AM stability during storage. The utility of rapidly metabolised heroin specific compounds in blood as indicators of survival period following heroin intake and the role of concomitant drug consumption in heroin fatalities was also discussed in this thesis
