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The purpose of this study was to investigate the effects of cooling and heating of muscles on parameters of surface EMG (SEMG) under various well defined grades of isometric muscle contraction. In 32 healthy volunteers, aged 20-30 years, turns and amplitude (RMS) analysis was done in SEMG from the hand extensors. Muscle strength was defined by a new developed hand dynamometer. Values for RMS and turns in case of maximal voluntary contraction (MVC) over periods of 20 sec were determined for each volunteer and subsequently RMS and turns were measured during isometric contractions of 10%, 30%, 50% and 80% of MVC, interrupted each by rest periods. This procedure was repeated after cooling and warming the forearm with thermo packs. For control purposes the same investigations with three measurement periods of SEMG were done following the same time schedule without thermic stimuli. With increasing isometric contractions turns increased after heat application and decreased after ice application, compared to the values achieved without thermic stimuli. The differences were significant from a level of 30% of MVC (p < 0.05). No corresponding changes were seen for RMS. In the control experiment values of turns and RMS did not differ in the three measurement periods. It is concluded, that the amplitude in SEMG tracings seems to be a reliable parameter of muscle force, whereas turns are sensitive to temperature. They might be useful markers for therapeutic approaches targeted at the muscle.

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OBJECTIVE: To translate the Fibromyalgia Impact Questionnaire (FIQ) into German and to evaluate its reliability and validity for the use of German speaking patients with fibromyalgia (FM). METHODS: We administered the FIQ to 55 patients with FM (15 patients filled out the questionnaire 10 days later) together with German versions of the Stanford Health Assessment Questionnaire (HAQ), the Medical Outcomes Survey Short Form-36 (SF-36), and a tender point count (TPC). All patients were asked about the severity of pain today (10 cm visual analog scale) and the duration of symptoms. Tenderness thresholds were assessed by dolorimetry at all tender points with a Fisher dolorimeter and laboratory tests were obtained. Test-retest reliability was assessed using Spearman correlations. Internal consistency was evaluated with Cronbach's alpha of reliability. Construct validity of the FIQ was evaluated by correlating the HAQ and subscales of the SF-36 as well as the TPC and the tenderness thresholds. RESULTS: Mean age of participants was 54.3 years and mean duration of symptoms 9.5 years. Test-retest reliability was between 0.62 and 1 for the physical functioning as well as for the total FIQ and other components. Internal consistency was 0.92 for the overall FIQ. Significant correlations were obtained between the FIQ items, the HAQ, and the SF-36. CONCLUSION: The German FIQ is a reliable and valid instrument for measuring functional disability and health status in German patients with FM.

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OBJECTIVE: To analyze the genotypes of the promoter region of the serotonin transporter gene (5-HTT) in patients with fibromyalgia (FM). METHODS: Genomic DNA from 62 patients meeting the American College of Rheumatology 1990 criteria for FM and 110 healthy controls was analyzed by polymerase chain reaction. Additionally, the psychopathologic state of 52 of the FM patients was evaluated using the Beck Depression Inventory (BDI) and the Symptom Checklist-90-Revised (SCL-90-R). RESULTS: The 5-HTTLPR genotypes in FM patients versus controls were distributed as follows: L/L 27% versus 34%, L/S 42% versus 50%, and S/S 31% versus 16%. FM patients with the S/S genotype had higher mean scores on the BDI and the SCL-90-R compared with those in the L/L and L/S groups. CONCLUSION: A higher frequency of the S/S genotype of 5-HTT was found in FM patients compared with healthy controls. The S/S subgroup exhibited higher mean levels of depression and psychological distress. These results support the notion of altered serotonin metabolism in at least a subgroup of patients with FM.

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Rats were exposed continuously to Pb in utero and after birth by giving their mothers, during pregnancy and lactation, drinking water containing 0, 5, 25, 100, or 500 ppm Pb (as Pb acetate); they were sacrificed at 1 month of age, at which time their mean blood Pb concentrations were, respectively, approximately 3, 9, 19, 30, and 70 micrograms/dl. All Pb-exposed groups sacrificed by decapitation had elevated mean plasma renin activities (PRA), relative to controls. Pentobarbarbital-anesthesia and laparotomy markedly increased PRA in the 0, 100, and 500 ppm groups, but the increase was significantly less in the 100 ppm group. Renal renin concentration was normal in the 5 and 25 ppm groups, but was significantly increased in the 100 and 500 ppm groups. The ratio of plasma angiotensin II to PRA was normal in the 100 ppm group but significantly reduced in the 500 ppm group. We conclude that exposure of rats in utero and during lactation to doses of Pb which produce blood Pb concentrations similar to those generally present in human populations stimulates basal renin secretion in 1-month-old rats, but partially inhibits the response to renin-releasing stimuli. The highest dose reduces plasma angiotensin II at any given PRA. These results, taken with previous publications, emphasize that the effects of lead on plasma renin even within a single species are greatly affected by the timing of the exposure.

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Rats were exposed continuously to Pb in utero and after birth by giving their mothers, during pregnancy and lactation, drinking water containing 0, 100, or 500 ppm Pb (as Pb acetate) and then continuing this regimen after weaning. Male rats received 100 ppm developed a significant elevation of systolic blood pressure (152 +/- 3.7 mm Hg vs. 135 +/- 5.6 for controls) at 3 1/2 months and remained hypertensive until sacrifice at 6 months; 500 ppm rats remained normotensive. Both 100 ppm and 500 ppm females remained normotensive. At 6 months, PRA was significantly reduced in the 100 ppm male group but was normal in the 500 ppm group. There were dose-dependent decreases in the AII/PRA ration and in renal renin. Pulmonary converting enzyme activity was not changed by Pb exposure. Blood [Pb] was 40 and 71 mug/dl, respectively, and kidney [Pb] was 4.8 and 22.9 mug/gm. Renal histology was normal in the 100 ppm group. We conclude that doses of Pb which produce blood [Pb] seen in many people are capable of inducing modest hypertension in male rats; higher doses fail to do so. The hypertension is associated with a reduction in PRA and All and therefore is unlikely to be due to hyperactivity of the RAS. (J Lab Clin Med 99:354, 1982.)

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The major purpose of this study was to determine whether acute or chronic Pb exposure would increase urinary excretion of zinc in the rat. Four groups of unanesthetized rats were given 0, 0.03, 0.3, or 3 mg Pb (as acetate) kg intravenously, and urinary excretion of zinc, sodium, and potassium was monitored for 6 h. Only at the highest dose was urinary Zn excretion significantly elevated; there were no significant changes in sodium and potassium excretion at any dose. Two other groups of rats were studied for 9 weeks in metabolism cages before and during administration of either 500 ppm Pb (as acetate) or equimolar Na acetate in the drinking water. Two days after Pb treatment and continuing through day 35, Zn excretion was elevated in the Pb-exposed animals; beyond this day, zinc excretion became similar in the two groups. The difference in Zn excretion was not the result of lower water intake by the Pb-treated animals. At sacrifice (70 days after starting Pb exposure), Pb-exposed animals had lower Zn content of the plasma and testis, but there was no difference in kidney Zn. Plasma renin activity was significantly higher in Pb-exposed animals. We conclude that chronic Pb exposure in rats can result in some degree of decreased tissue zinc, which is, at least in part, secondary to increased urinary losses of zinc.