The relationship between the VO2 slow component, muscle metabolites and performance during very-heavy exhaustive exercise.

This study examined the relationship between the V O(2) response, particularly the slow component (SC), muscle metabolite changes and performance during very-heavy exhaustive exercise. Sixteen active females performed a graded exercise test to determine V O(2peak) and the lactate threshold followed 48h later by a constant-load cycle test to exhaustion (ET) at 85% V O(2peak) intensity. Muscle biopsies and capillary blood samples were obtained before and after the ET to determine changes in muscle ATP, pH, lactate and phosphocreatine and also plasma pH and lactate. Breath-by-breath data from the ET were smoothed using 5-s averages and fit to a three-component exponential model. The mean time to exhaustion (t(exh)) during the ET was 16.8 (+/-6.4) min. Results showed no correlation between the SC and t(exh) or any muscle metabolite changes (p>0.05). Significant correlations (p<0.05) were evident between t(exh) and tau; tau(0) (r=-0.54), tau(1) (r=-0.65), change in (Delta) pH(b) (r=-0.60), Delta[La(-)](b) (r=-0.58) and [La(-)](b post) (r=-0.64). Significant correlations (p<0.05) were also evident between tau(1) and [La(-)](b post) (r=0.54). Furthermore, a negative value resulted when the accumulated oxygen deficit was calculated for the entire duration of the ET. Results showed no association between the amplitude of the SC and t(ext) or to changes in muscle/blood metabolites, suggesting that the SC is not a determinant of high-intensity exercise tolerance. Furthermore, it is possible that a reduced perturbation of anaerobic energy sources, as a result of a faster tau(1), may have contributed to a longer t(exh).     

Active rehabilitation for chronic low back pain: Cognitive-behavioral, physical, or both? First direct post-treatment results from a randomized controlled trial [ISRCTN22714229]

Background  

The treatment of non-specific chronic low back pain is often based on three different models regarding the development and maintenance of pain and especially functional limitations: the deconditioning model, the cognitive behavioral model and the biopsychosocial model.     

Thermal oxidation of polycyclic aromatic hydrocarbons adsorbed on alumina

The reevaporation of polycyclic aromatic hydrocarbons (PAH) from secondary alumina (alumina used in a fluidized bed for pot gas cleaning) used in the production of aluminum in aluminum reduction plants has been studied. The secondary alumina contains around 100 ppm of PAH when introduced to the pots. The results of this study indicate that only a minor part of the adsorbed PAH is reevaporated at the pot temperature of 300-400 degrees C and that the use of secondary alumina has little effect on the PAH concentration in the workplace atmosphere of the aluminum reduction plants.     

Mental illness in Greek and Turkish adolescents

Summary Samples of 867 Greek adolescents in Munich, 2,702 Greek adolescents in Greece and 2,780 Turkish adolescents in Turkey were assessed concerning mental health in a two-stage procedure. In the first stage the General Health Questionnaire (GHQ) was used for screening. Significant age differences in the GHQ 28-item scale and most of its subscales were observed mainly for the samples in the homeland. Male adolescents had lower scores than female adolescents in the GHQ 28-item scale and its sub-scales while social class appeared to be of little influence. Significantly higher GHQ-28 scores were obtained for Greeks and Turks in their homelands as compared to Greeks in Munich. The GHQ-28 correlations with the Anorexia Nervosa Inventory for Self-Rating were fairly high. A principal component analysis with Varimax rotation showed fairly consistent results for this age group when compared with the results of Goldberg and Hillier (1979). With the exception of the GHQ factor social dysfunction Greek adolescents in their homeland had significantly higher scores in the total GHQ-28 and its sub-scales than Greeks in Germany. Thus, our data do not confirm the acculturation-stress hypothesis. The data would be consistent with the hypothesis of selective migration which states that Greek adolescents in Germany constitute a positive selection with respect to risk for mental illness.     

A year's experience with tuberculosis in a private urban teaching hospital in the postsanatorium era

Because brief general hospital admission and extended ambulatory management have replaced sanatorium care for tuberculosis, we reviewed 41 cases admitted to a private urban hospital during 1971–1972 to assess the spectrum of disease and the problems created by the closing of sanatoriums. Almost half the cases were misdiagnosed, exposing an average of 35 hospital personnel to unisolated patients with positive smears. Clinical manifestations often were subtle. Of those with pulmonary involvement, 14 per cent denied having symptoms and less than half had positive sputum smears. Transfer to ambulatory care for half the patients was complicated by having different physicians manage their hospital and outpatient care, with poor communication between the two. Outpatient physicians were sent discharge summaries for fewer than two thirds of their patients, and then only after an average $\text{2}\text{1}\text{2}$ month delay. Similarly, slowness in case reporting impaired contact investigation. Only three contacts were identified per patient, and only 71 per cent of these were investigated. Improved diagnostic ability, better communication with public health workers, and attention to details of transfer to ambulatory care are necessary for effectively integrating the present components of tuberculosis management.     

In vitro thrombogenicity tests of factor IX concentrates. I. A survey of available assays

Various factor IX concentrates have been examined in a number of in vitro tests of thrombogenicity. The results suggest that some tests are superfluous as in concentrates with activity in any of these tests activation is revealed by a combination of the non-activated partial thromboplastin time, the thrombin (or Xa) generation time and factor VIII inhibitor bypassing activity tests. Assay of individual coagulant enzymes revealed that most concentrates contained more factor IXa than Xa. However only a small number of concentrates, chiefly those that had been purposefully activated, contained appreciable amounts of either enzyme.     

Plasma antioxidants and coronary heart disease: vitamins C and E, and selenium

The possibility of a relation between plasma antioxidants such as vitamins C and E and selenium, and mortality from coronary heart disease (CHD) was examined. A cross-sectional survey was undertaken of random population samples of apparently healthy middle-aged men in four European regions with differing mortalities from CHD [rate/100,000 for men aged 40-49]: north Karelia (eastern Finland) (n = 99) [212/100,000]; south-west Finland (n = 85) [146/100,000]; Scotland (n = 131) [140/100,000]; and south Italy (n = 80) [43/100,000]. Median (5th-95th percentile) plasma vitamin C concentrations were lower in Scotland: 18.2 (5.7-61.3) microM than in other regions: north Karelia 28.4 (6.2-85.2); south-west Finland 33.5 (5.7-76.6); south Italy 38.0 (10.2-69.8) microM (P less than 0.001). The median levels in the four areas did not however reflect the regional CHD mortality rates. Regional differences in plasma vitamin E levels were also observed: Scottish levels were low 20.0 (12.1-29.3) microM (P less than 0.001) and did not differ between the other areas: 23.0 (16.7-35.1), 22.5 (13.7-31.6) and 23.9 (15.6-41.3) microM respectively. The vitamin E gradient could be explained in part by differences in serum cholesterol. However, cholesterol-adjusted vitamin E levels were low in the three high CHD areas: Scotland 3.41 (2.41-4.62); north Karelia 3.53 (2.67-5.18); south-west Finland 3.53 (2.58-4.92); Italy 4.81 (3.25-5.99) mumol/mmol cholesterol (P less than 0.001). Cholesterol-adjusted vitamin E was not lower in north Karelia, the higher CHD mortality area in Finland. Serum selenium values also varied with the area examined and reported low levels in Finland were confirmed. Nevertheless, selenium levels did not correlate with the reported mortality rates of CHD. Thus in our small cross-cultural study the evidence did not support our hypothesis that plasma antioxidants explain regional differences in CHD mortality.     

B-CLL cell surface markers and mitogen-induced thymidine uptake: a comparison between lymph node cells and peripheral blood lymphocytes in 25 patients

Lymphocytes from peripheral blood and lymph nodes from 25 patients with B-CLL were analysed by immunofluorescent staining of surface membrane immunoglobulin (SmIg), the B-cell marker B1, and the T-cell markers Leu 1/2/3/4. Tritium-thymidine uptake was measured in mitogen-stimulated 4-day cultures. Differences in these parameters between cells from the two sources in each patient were calculated with the paired T-test. All cell samples showed a clonal B-cell population. More blood lymphocytes than lymph node cells expressed the monoclonal SmIg (mu or gamma, p = 0.04; kappa or lambda, p less than 0.01), and T-cells were more frequent in lymph nodes (p = 0.01), where the T helper/suppressor ratio was higher. Furthermore, lymph node cells showed a higher thymidine uptake in response to the mitogens LPS, PWM, and Cowan (p = 0.01, p = 0.01, and p = 0.004, respectively), but there was no difference in the responses to EBV, DxS, TPA and PHA (p greater than 0.5). The higher response in lymph node cells to some mitogens might in part be explained by differences in the numbers of accessory cells, such as T-helper cells, but also by the existence of leukaemic B-cell subsets with different mitogen response patterns and different distributions within the lymphoid compartments. The characterization of subsets within a malignant cell clone might be of clinical importance.     

Secondary radiation damage as the main cause for unexpected volume effects: a histopathologic study of the parotid gland

PURPOSE: To elucidate with a histopathological study the mechanism of region-dependent volume effects in the partly irradiated parotid gland of the rat. METHODS AND MATERIALS: Wistar rats were locally X-irradiated with collimators with conformal radiation portals for 100% volume and 50% cranial/caudal partial volumes. Single doses up to 40 Gy were applied. Parotid saliva samples were collected, and the three lobes of the parotid gland were examined individually on the macro- and micromorphologic level up to 1 year after irradiation. RESULTS: Dose-dependent loss of gland weight was observed 1 year after total or partial X-irradiation. Weight loss of the glands correlated very well with loss of secretory function. Irradiating the cranial 50% volume (implicating a shielded lateral lobe) resulted in substantially more damage in terms of weight loss and loss of secretory function than 50% caudal irradiation (shielding the ventral and dorsal lobe). Histologic examinations of the glands 1 year after irradiation revealed that the shielded lateral lobe was severely affected, in contrast to the shielded ventral and dorsal lobes. Time studies showed that irradiation of the cranial 50% volume caused late development of secondary damage in the shielded lateral lobe, becoming manifest between 240 and 360 days after irradiation. The possible clinical significance of this finding is discussed. CONCLUSION: It is concluded that the observed region-dependent volume effect for late function loss in the rat parotid gland after partial irradiation is mainly caused by secondary events in the shielded lateral lobe. The most probable first step (primary radiation event) in the development of this secondary damage is radiation exposure to the hilus region (located between the ventral and dorsal lobe). By injuring major excretory ducts and supply routes for blood and nerves in this area, the facility system necessary for proper functioning of the nonexposed lateral lobe is seriously affected. The unexpected volume effect in the rat might have consequences for treatment strategies in radiotherapy, implicating not only salivary glands but also other organs with a seemingly homogeneous distribution of radiosensitive elements, a situation wherein volume effects have not been anticipated up to now.