Effects of training at simulated altitude on performance and muscle metabolic capacity in competitive road cyclists

Summary Differences between the effects of training at sea level and at simulated altitude on performance and muscle structural and biochemical properties were investigated in 8 competitive cyclists who trained for 3–4 weeks, 4–5 sessions/week, each session consisting of cycling for 60–90 min continuously and 45–60 min intermittently. Four subjects, the altitude group (AG), trained in a hypobaric chamber (574 torr=2300 m above sea level), and the other four at sea level (SLG). Before and after training work capacity was tested both at simulated altitude (574 torr) and at sea level, by an incremental cycle ergometer test until exhaustion. Work capacity was expressed as total amount of work performed. Venous blood samples were taken during the tests. Leg muscle biopsies were taken at rest before and after the training period. AG exhibited an increase of 33% in both sea level and altitude performance, while SLG increased 22% at sea level and 14% at altitude. Blood lactate concentration at a given submaximal load at altitude was significantly more reduced by training in AG than SLG. Muscle phosphofructokinase (PFK) activity decreased with training in AG but increased in SLG. All AG subjects showed increases in capillary density. In conclusion, work capacity at altitude was increased more by training at altitude than at sea level. Work capacity at sea level was at least as much improved by altitude as by sea level training. The improved work capacity by training at altitude was paralleled by decreased exercise blood lactate concentration, increased capillarization and decreased glycolytic capacity in leg muscle.     

New microtransducer for physiological pressure recordings

A new pressure microtransducer, which utilises a closed air volume instead of a diaphragm as the elastic medium, has been developed. Volume variations are transferred into an electrical signal via an electrolytic conductance cell, which is situated adjacent to the air volume. This arrangement eliminates the problems associated with diaphragm mounting and also gives high pressure sensitivity. The inherent nonlinearity of the input-output characteristics has a simple analytical form and can therefore be effectively reduced by an inexpensive analogue network. It is also shown that the thermal expansion of the air can be balanced by the temperature coefficient of the conductance cell. The overall performance of the sensor fulfils the requirements of most biomedical applications, and its simple and rugged construction should make it suitable for routine work.     

Die funktionelle Anatomie des Cricoarytaenoidgelenkes

Zusammenfassung An 12 Kehlköpfen von Individuen im Alter von 40–75 Jahren wird das Cricoarytaenoidgelenk (C.a.-Gelenk) untersucht, und zwar teils mit Dissektion unter der Lupe, teils mit histologischer Technik und Serienschnitten. Das Gelenk hat das für ein Zylindergelenk charakteristische Aussehen. Die Gelenkfläche des Cricoidknorpels ist wie ein Teil der Mantelfläche eines Zylinders geformt, während die Gelenkfläche des Arytaenoidknorpels eine konkave Form aufweist, die der des Cricoidknorpels gut entspricht. Das C.a.-Gelenk ist ein Gelenk von verhältnismäßig stabiler Art, und besitzt nur eine Bewegungsachse, die schräggestellt ist und von dorso-medio-kranial nach ventro-latero-caudal verläuft. An dieser Achse spielt sich Rotation (c:a 35°) und Translation (c:a 2 mm) ab. Schließlich werden die Muskelfunktion und deren Relation zu der schrägen Bewegungsachse studiert. Der Effekt der wichtigsten Larynmmuskeln auf die Arytaenoidknorpelbewegungen wird beleuchtet.Mit Unterstützung der Medizinischen Fakultät der Universität Lund.     

Release of corticosteroids from human adrenals in vitro

From morphological criteria, it is often difficult to evaluate whether adrenocortical tumors secrete hormones or not. An increasing number of nonfunctioning tumors are detected using modern imaging techniques. In a consecutive series of 13 patients with adrenocortical disease, a functional characterization was done by determining the ability of the resected tissue to release cortisol and aldosterone in vitro. Significant secretion of aldosterone was only found in tumors from 4 patients with hyperaldosteronism, 1 of whom turned out to have a cortisol-secreting tumor as well. All other tumors, both from patients with Cushing's syndrome and patients judged to have nonfunctioning adenoma, released cortisol in vitro. The method provides valuable pathophysiological information on adrenal tumors.

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Resumen Con base en criterios morfológicos, frecuentemente es difícil determinar si los tumores adrenocorticales secretan hormonas o no. Con el uso de las modernas técnicas de imagenología, se détecta un numéro creciente de tumores no funcionantes. En una serie consecutiva de 13 pacientes con patología adrenocortical, se realizó una caracterización funcional determinando la capacidad del tejido resecado para liberar cortisol y aldosterona in vitro. Se encontró secreción significativa de aldosterona sólo en tumores provenientes de 4 de nuestros pacientes con hiperaldosteronismo, 1 de los cuales también presentó un tumor secretor de cortisol. Todos los otros tumores, tanto de pacientes con síndrome de Cushing como de pacientes que se considéró tenían adenoma no funcionante, liberaron cortisol in vitro. El método provee valiosa información patofisiologica sobre los tumores suprarrenales.

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Résumé Il est souvent difficile, à partir des critères morphologiques, d'évaluer si les tumeurs corticosurrénaliennes sont des tumeurs sécrétantes ou non. Un nombre croissant de tumeurs dites nonfonctionnantes sont détectées par l'utilisation des techniques modernes d'imagerie. Une caractérisation fonctionnelle est réalisée par les auteurs à partir d'une série consécutive de 13 patients présentant une pathologie corticosurrénalienne en determinant les capacités de sécrétion in vitro de cortisol et d'aldostérone du tissu réséqué. Une sécrétion significative d'aldostérone est présente seulement dans les tumeurs de 4 patients avec hyperaldostéronisme, l'un d'entre eux révéla posseder de même une tumeur sécrétant du cortisol. Dans tous les autres cas, aussi bien chez les patients avec un syndrome de Cushing que chez les patients considérés comme ayant un adénome nonfonctionnant, les auteurs observent une sécrétion de cortisol in vitro. Cette méthode donne une information physiopathologique précieuse sur les tumeurs surrénaliennes.

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Presented at the International Association of Endocrine Surgeons in Paris, September 1985.

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Supported by grants from the Swedish Medical Research Council (2330) and Karolinska Institute.     

Accommodative facility training with a long term follow up in a sample of school aged children showing accommodative dysfunction

The primary aim of this project was to study the effect of flip lens-training on the accommodative function in a group of children with accommodative dysfunction and subjective symptoms such as asthenopia, headache, blurred vision, and avoidance of near activity. We also wanted to measure the accommodative facility among the children in comparison with a control group. Another aim of the study was whether flip lens-training increased accommodative facility, and to find out if it also had a positive effect on their asthenopia and related problems also in long term. Following the training period the accommodative facility and accommodative function significantly increased and two years after finishing the training period no child had regained any subjective symptoms and the objective findings were almost the same as at the end of facility training period. These results suggest that accommodative facility training is an efficient method built on loss of symptoms among children with accommodative infacility. This revised version was published online in July 2006 with corrections to the Cover Date.     

Comparison of CGS 15943, ZM 241385 and SCH 58261 as antagonists at human adenosine receptors

Three structurally related non-xanthine compounds, CGS 15943, ZM 241385 and SCH 58261, are potent A_2A adenosine receptor antagonists and have been used as tools in many pharmacological studies. We have now characterized their affinity and selectivity profile on human adenosine receptors stably transfected into either CHO cells (A₁ and A_2B receptors) or HEK-293 cells (A_2A and A₃ receptors). In binding studies using [³H]SCH 58261 as a radioligand, the three compounds were equally potent at A_2A receptors, their K _i value being less than 1 nM. Affinity for A₁ and A₃ receptors was measured using [³H]DPCPX and [¹²⁵I]AB-MECA as radioligands. Given the lack of selective ligands, interaction with A_2B receptors was assessed using the cAMP accumulation assay following stimulation by the adenosine receptor agonist N-ethylcarboxamidoadenosine (NECA). CGS 15943 was almost as potent at A₁ receptors (K _i 3.5 nM) as at A_2A receptors, showed moderate affinity for A₃ receptors (K _i 95 nM) and also interacted with A_2B receptors (K _i 44 nM; pA₂ 7.5). ZM 241385 showed little affinity for A₁ receptors (K _i 255 nM), and did not interact with A₃ receptors (K _i>10 μM); however, it displayed moderate affinity for A_2B receptors (K _i 50 nM; pA₂ 7.3). SCH 58261 had weak affinity for A₁ receptors (K _i 287 nM), no interaction with A₃ receptors (K _i>10 μM), and showed negligible interaction with A_2B receptors (K _i 5 μM; pA₂ 6.0). These data indicate that SCH 58261 is the most selective A_2A antagonist currently available. Moreover, the different receptor selectivity of these three chemically related compounds provides useful information to progress with structure-activity relationship studies. Received: 2 July 1998 / Accepted: 6 October 1998     

The adjuvant effect of tuberculin in experimental sensitization to merthiolate

Summary When guinea pigs were sensitized to tuberculin by exposure to complete Freund's adjuvant the size of the intradermal PPD test was positively correlated to the body weigth of the animal. Old Tuberculin showed stimulating effect in a subsequent sensitization to merthiolate (thimerosal). The high frequency of delayed cutaneous allergy to merthiolate in the Swedish population is probably explained by sensitization through intradermal testing with tuberculin containing merthiolatc as a preservative.

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Zusammenfassung Bei Meerschweinen, die mit Hilfe von Freunds Adjuvant gegen Tuberculin sensibilisiert wurden, konnte eine Korrelation zwischen der Größe des Intracutantests und dem Körpergewicht der Tiere festgestellt werden. Old Tuberculin zeigte in einem darauffolgenden Sensibilisierungsversuch mit Merthiolat einen stimulierenden Effekt auf die allergische Reaktion gegen Merthiolat. Die hohe Frequenz von allergischen cutanen Spätreaktionen gegen Merthiolat in der schwedischen Bevölkerung ist wahrscheinlich als Sensibilisierung durch Intracutantest mit Tuberculin, das als Konservierungsmittel Merthiolat enthält, zu erklären.

     

Conduiturinary diversion and urinary-tract infection. I. Serum antibody titers against Escherichia coli and Proteus mirabilis in relation to urographic findings.

The serum antibody titers against Escherichia coli and/or Proteus mirabilis were elevated in 26 of 80 patients (33%) with a conduit urinary diversion. Urographic findings were abnormal in 44 of these 80 patients (55%). Urography was normal in 59% of the patients with normal antibody titers, but in only 15% of those with elevated titers. Raised antibody levels against E. coli O antigen (greater than 256 before and/or greater than 32 after mercaptoethanol treatment of serum) were associated with wide upper urinary tract or calculi more often than were normal E. coli antibody titers. Raised titers against P. mirabilis (greater than 256 before and/or greater than 32 after mercaptoethanol treatment of serum) were associated with scarring of the renal parenchyma more frequently than were normal titers. A statistically significant association was found between "small" kidney area and raised serum antibody titers against E. coli or P. mirabilis. The frequency of "small" kidney increased with the time lapse after urinary diversion. At 3 to 11 months postoperatively it was 29%, but among the patients with urinary diversion for more than five years the corresponding frequency was 82%. When at least one kidney was "small", the serum creatinine was higher than when both kidneys were of normal size. Patients with raised antibody titers tended also to have high serum creatinine (greater than or equal to 124 mumol/l) more often than those with normal titers (23 vs. 10%). These observations imply a connection between elevation of the antibody titers and destruction of the renal parenchyma in patients with conduit urinary diversion. They illustrate the value of antibody titration in the follow-up of patients with urinary diversion.     

Food effects on tablet disintegration.

The aims of the present study was to investigate if food components, as represented by a multi-component nutritional drink for tube feeding, could affect tablet disintegration of standard tablets in vitro as well as in vivo and propose a mechanism for potential food effects on tablet disintegration. The tablet disintegration was delayed between 5 min and more than 1h in the simulated gastric fed medium compared to a simple buffer. This effect was dependent on the tablet composition. A similar delay in tablet disintegration was also found in vivo after administration of the nutritional drink to three Labradors as observed by removing the tablet from the stomach at different times through a gastric fistula. The delay in tablet disintegration appeared to be caused by precipitation of a film, mainly consisting of protein, on the tablet surface as indicated by disintegration studies with pure nutrients, identification by IR spectroscopy of contents of precipitates obtained in a model study were the nutrients were incubated with different tablet excipients and visual observations of tablets exposed to the simulated fed medium. The drug dissolution of a soluble compound, metoprolol tartrate, from a standard tablet was also strongly delayed in the simulated fed medium. In conclusion, food, could significantly delay tablet disintegration and drug dissolution in the stomach by formation of a film around the tablets. This effect could be monitored by a simple in vitro disintegration test using a test medium based on a nutritional drink. More studies are needed to investigate the significance of the slow tablet disintegrations on bioavailability and for which types of food the present effect occurs.     

Acute management and outcome of multiple trauma patients with pelvic disruptions

ABSTRACT: INTRODUCTION: Data on pre-hospital and trauma room fluid management of multiple trauma patients with pelvic disruptions are rarely reported. Present trauma algorithms recommend early haemorrhage control and massive fluid resuscitation. By matching the German Pelvic Injury Register (PIR) with the TraumaRegister DGU(R) (TR) for the first time, we attempt to assess the initial fluid management for different Tile/OTA types of pelvic ring fractures. Special attention was given to the patient's post traumatic course, particularly ICU data and patient outcome. METHODS: A specific match code was applied to identify certain patients with pelvic disruptions from both PIR and TR anonymous trauma databases, admitted between 2004 and 2009. From the resulting intersection set, a retrospective analysis was done of pre-hospital and trauma room data, length of ICU stay, days of ventilation, incidence of multiple organ dysfunction syndrome (MODS), sepsis, and mortality. RESULTS: In total 402 patients were identified. Mean ISS was 25.9 points and the mean ratio of patients with ISS [greater than or equal to]16 was 85.6%. The fracture distribution was as follows: 19.7% type A, 29.4% type B, 36.6% type C, and 14.3% isolated acetabular and/or sacrum fractures. The type B/C, compared with type A fractures, were related to constantly worse vital signs that necessitated a higher volume of fluid and blood administration in the pre-hospital and/or the trauma room setting. This group of B/C fractures were also related to a significantly higher presence of concomitant injuries and related with increased ISS. This was related to increased ventilation and ICU stay, increased rate of MODS, sepsis and increased rate of mortality at least for the type C fractures. Approximately 80% of the deceased had sustained type B/C fractures. CONCLUSIONS: The present study confirms the actuality of traditional trauma algorithms with initial massive fluid resuscitation in the recent therapy of multiple trauma patients with pelvic disruptions. Low volume resuscitation seems not yet accepted in practice in managing this special patient entity. Mechanically unstable pelvic ring fractures type B/C (according Tile's/OTA classification) form a distinct entity that has to be considered notably in future trauma algorithms.