Patient-specific fibre-based models of muscle wrapping.

In many biomechanical problems, the availability of a suitable model for the wrapping of muscles when undergoing movement is essential for the estimation of forces produced on and by the body during motion. This is an important factor in the Osteoporotic Virtual Physiological Human project which is investigating the likelihood of fracture for osteoporotic patients undertaking a variety of movements. The weakening of their skeletons makes them particularly vulnerable to bone fracture caused by excessive loading being placed on the bones, even in simple everyday tasks. This paper provides an overview of a novel volumetric model that describes muscle wrapping around bones and other muscles during movement, and which includes a consideration of how the orientations of the muscle fibres change during the motion. The method can calculate the form of wrapping of a muscle of medium size and visualize the outcome within tenths of seconds on commodity hardware, while conserving muscle volume. This makes the method suitable not only for educational biomedical software, but also for clinical applications used to identify weak muscles that should be strengthened during rehabilitation or to identify bone stresses in order to estimate the risk of fractures.

Molecular phylogeographic analyses of the loach Oxynoemacheilus bureschi reveal post-glacial range extensions across the Balkans.

Rivers on the Balkan Peninsula can be separated into ichthyofaunistic areas with different endemic fish species. The Vardar River contains a particularly large number of endemics, indicating its complete and long-term isolation from neighbouring river systems. One of the few species shared with other rivers is the loach species Oxynoemacheilus bureschi. In this study, the genetic analyses of 175 individuals of O. bureschi from 17 sites, covering the entire distribution of the species, including the Rivers Vardar (= Axios), Struma (= Strymon), Mesta (= Nestos) and Danube, were performed using one mitochondrial and one nuclear marker. Genetic differentiation among populations was in general low. Shared haplotypes were common and occurred even between distant localities and different river systems. This points to a high degree of gene flow among populations and rejects the hypothesis that the population in the Vardar River represents a relict from an early colonization of the Balkan Peninsula. In contrast, the results suggest that populations in the Vardar River, as well as those in the Danube River, are of recent origin, and a human-mediated introduction cannot be excluded. On the other hand, the populations in the Aggitis River, a left tributary of the lower Struma River, were clearly separated from the rest of the species and represent a long-term isolated lineage. Demographic analyses suggest a recent population expansion for O. bureschi, in which the population in the Aggitis River was not involved.

[Two hundred years from the birth of Professor Josef Skoda]. / 200 let od narození Profesora Josefa Skody.

The article deals with the life and work of the eminent professor of internal medicine Josef Skoda, a native of Plzen, who especially deserved of the introduction of examination by percussion and auscultation. He supported materially his nephew Emil and so he contributed to the expansion of Skoda's factory in Plzen.

[Effect of antioxidant therapy on indicators of free radical activity in workers at risk of lead exposure]. / Ovlivnení ukazatelu pusobení volných radikálu u pracovníku v riziku olova antioxidacní lécbou.

The authors administered to 36 workers exposed to lead, for four weeks the preparation Prolong which contains vitamin C, vitamin E, beta-carotene, selenium, zinc and chromium and investigated the effect on indicators of free radicals. A statistically significant increase of the following occurred: superoxide dismutase (p < 0.001), glutathione peroxidase (p < 0.01), an increase of the total antioxidant capacity (p < 0.01) and an increase of uricaemia (p < 0.05). Based on these results the authors consider supplementation with antioxidants indicated in workers exposed to lead.

Psychologists in medical schools in 1997. Research brief.

The activities, income, and medical staff membership and limitations on that membership for psychologists working in U.S. medical school settings in 1997 were examined. A total of 1,938 psychologists responded to a survey conducted by the Research Office of the American Psychological Association, in conjunction with the Association of Medical School Psychologists. Some of the most salient findings were that (a) the largest number of psychologists was involved in research activities, (b) just over half of medical school psychologists were required to generate all or part of their own income through clinical work and research, and (c) the majority of these psychologists were members of a medical staff but were not extended full medical staff privileges. These and other results are discussed in the context of academic rank, tenure status, and other relevant factors.

[Indicators of effects of free radicals in workers at risk of lead exposure]. / Ukazatelé pusobení volných radikálu u pracovníku v riziku olova.

The authors examined indicators of the action of free radicals in 40 workers exposed to the risk of lead (work with lead containing glazing and prints). The lead concentration in the atmosphere did not exceed the highest permissible concentrations and the biological exposure tests as regards lead exposure did not exceed the highest permissible limits. In the examined subjects the authors found a significantly elevated level of superoxide dismutase activity (p < 0.05) which suggests long-term increased peroxide formation. The correlation of the selenium concentration in blood and the period of lead exposure was at the borderline of statistical significance (p = 0.1159). Further investigations will be focused on subjects with symptoms of increased exposure to lead and lead intoxication where the probability of pathological findings is greater.

[Trace elements in biological materials. Preanalysis safeguards]. / Stopové prvky v biologických materiálech. Preanalytické zabezpecení.

In order to obtain objective information from estimations of trace elements (Al, As, Cd, Cr, Co, Cu, Pb, Li, Mn, Hg, Ni, Se, Zn) on deficiency or intake beyond the toxic limit it is necessary to pay attention among others also to preanalytical safeguarding, i.e. obtain all relevant information on the patient, ensure proper selection of material and sampling time, proper sampling and safeguarding the sample before the estimation proper. If the above rules and principles are respected, possible significant distortion on the results, which can be caused e.g. by contamination of the sample, can be prevented.

[The effect of antioxidant therapy on indicators of activity of free radicals in workers exposed to risks of styrene]. / Ovlivnení ukazatelu pusobení volných radikálu u pracovníku z rizika styrenu antioxidacní lécbou.

To 30 workers exposed to the risk of styrene for a period of 30 days a mixture of antioxidants was administered: vitamin C 200 mg, vitamin E 300 mg, selenium 20 mg, troxerutin 600 mg and beta-carotene 6 mg. Before the onset of supplementation and immediately afterwards laboratory indicators of antioxidant protection and lipid peroxidation were investigated. Before treatment workers exposed to the risk of styrene had a significantly higher malondialdehyde concentration (p < 0.01) and antioxidant capacity (p < 0.01) as compared with the control group. Due to the established positive correlation between these parameters (r = 0.42, p < 0.05) the findings can be evaluated as the result of increased exposure to free radicals. After supplementation a marked decline of the malondialdehyde concentration occurred p < 0.001) and a further rise of the antioxidant capacity (p < 0.001). The selenium concentration increased also markedly, the rise being more marked in subjects who had originally a lower concentration. There was a significant rise of uric acid which has an antioxidant effect (p < 0.01). The antioxidant enzymes superoxide dismutase and gluathione peroxidase did not change significantly. The results indicate the favourable effect of antioxidant treatment in subjects exposed to the risk of styrene.

[Mercury in dental amalgams--a stress on the body or poisoning?]. / Rtut ze zubních amalgamu--zátez organismu nebo intoxikace?

The human organism is exposed to mercury from the environment and working environment. In the diet the main source of mercury are marine fish. Amalgam fillings participate in the mercury load of the organism as was proved by investigations of the mercury content of the brain, kidneys and lenses. However, it was not confirmed that the mercury load from amalgam fillings caused intoxication.

[Zinc--physiology and pathophysiology]. / Zinek--fyziologie a patofyziologie.

The authors discuss the physiology and pathophysiology of zinc. They mention the main sources of exposure to zinc and its components. Zinc absorption in the digestive tract is regulated by cells of the intestinal mucosa, the main route of excretion is via faeces. Zinc is essential for the function of several enzymes, there are ample data on its participation in immune processes. The authors analyse the most commonly quoted causes of zinc deficiency and pathological conditions caused by acute exposure to zinc and its compounds. Chronic zinc intoxication was not described in human so far.

[Determination of free radical activity in workers at risk for styrene exposure]. / Stanovení úcinku volných radikálu u pracovnku v riziku styrenu.

The authors examined indicators of the effect of free radicals (MDA, SOD, GSHPx, selenium) in 38 workers exposed to styrene. They revealed a statistically significant (p < 0.01) correlation of SOD activity and the period of exposure to styrene and also a statistically significant correlation (p < 0.05) between urinary selenium excretion and the period of exposure to styrene as well as a statistically significant correlation (p < 0.01) between the MDA serum concentration and urinary selenium excretion. There is no statistically significant difference between the MDA plasma concentration among smokers and non-smokers, the SOD activity is significantly higher in non-smokers (p < 0.05). Based on the revealed findings the authors assume that free radicals may also play a part in the action of styrene on the organism.

The shifting gender composition of psychology. Trends and implications for the discipline.

Psychology, along with the majority of professions and scientific disciplines, has undergone dramatic shifts in gender composition over the past two decades. These changes have prompted concern that this increased participation by women may lead to erosion in the status of these occupations. This article describes the results of a case study of psychology conducted by a subcommittee of the American Psychological Association's (APA's) Task Force on the Changing Gender Composition of Psychology to examine the discipline's changing gender composition and the factors related to these shifts. Societal and disciplinary trends are examined, along with data on the patterns of men's and women's involvement in the educational pipeline and workplace. The results provide little support for the concern over the increasing representation of women and its impact on the prestige of the discipline. Rather, they suggest that changes in the nature and status of psychology per se may be at least partly responsible for the changes in male and female participation and that the nature, magnitude, and causes of these disciplinary changes require further examination. Specific recommendations for the APA prepared by another subcommittee of the Task Force are also presented in the Appendix.

[Is chromium an essential or a toxic element?]. / Patrí chrom mezi esenciální nebo toxické prvky?

Chromium holds a frequent and important place in toxicological literature. The large number of more or less important toxicological facts (e.g. allergic dermatoses, ulcer, perforations of the nasal septum, bronchitis, cancerogenity etc.) are the reason why chromium is conceived rather as a toxic element. On the other hand in the non-toxicological literature favourable actions of chromium are described (its relationship to carbohydrate utilization, the glucose tolerance factor, diabetes etc.) which may induce us to consider chromium an essential element. Is chromium toxic or essential? It is both. The concept of essential or toxic cannot be conceived statically, these terms are relative and depend on a number of other facts and data (dose, time, chemical form, individuality of the organism, interaction with other substances in the environment etc). This relative view has a more general validity not only for chromium but for trace elements in general and it is very important in particular with regard to prevention of health damage caused by deficiency or excess of a substance.