Regulation of adiponectin gene expression in adipose tissue by thyroid hormones

Available experimental data suggest that adiponectin and thyroid hormones have biological interaction in vivo. However, the effects of thyroid hormones on adipose adiponectin gene expression in thyroid dysfunction are unclear. We induced hyper- (HYPER) and hypothyroidism (HYPO) by daily administration of a 12 mg/l of levothyroxine and 250 mg/l of methimazole in drinking water of rats, respectively, for 42 days. The white adipose tissues and serum sample were taken on days 15, 28, 42 and also 2 weeks after treatment cessation. Analysis of adiponectin gene expression was performed by real-time PCR and 2^−ΔΔct method. The levels of adipose tissue adiponectin mRNA in the HYPO rats were decreased during the 6-week treatment when compared to control rats (<0.05) and were increased significantly 2 weeks after HYPO cessation (P < 0.05). This decline in adiponectin gene expression occurred in parallel with a decrease in T3, T4, fT3 and fT4 concentrations (P < 0.05). In opposite to HYPO rats, adipose adiponectin gene expression was increased in HYPER rats during the 6-week treatment in parallel with an increase the thyroid hormones concentrations (P < 0.05), and its expression was decreased 2 weeks after HYPER cessation (P < 0.05). Adiponectin gene expression levels showed significant negative correlations with concentrations of LDL (HYPO; r = −0.806, P = 0.001 and HYPER; r = −0.749, P = 0.002), triglyceride (HYPO; r = −0.825, P = 0.001 and HYPER; r = −0.824, P = 0.001) and significant positive correlations with concentrations of glucose (HYPO; r = 0.674, P = 0.004 and HYPER; r = 0.866, P = 0.001) and HDL (HYPO; r = 0.755, P = 0.001 and HYPER; r = 0.839, P = 0.001). The current study provides evidence that adiponectin gene expression in adipose tissue is regulated by thyroid hormones at the translation level and that lipid and carbohydrate disturbances in a patient with thyroid dysfunction may be, in part, due to adiponectin gene expression changes.     

Habitual physical activity and peak anaerobic power in elderly women

The aim of this study was to investigate the relationship between maximal anaerobic power (P _max) and corresponding optimal velocity (V _opt) and habitual physical activity (PA) on the one hand and with maximal oxygen consumption (V˙O_2max) on the other hand, in elderly women. Twenty-nine community dwelling, healthy women aged 66–82 years participated in the study. PA was evaluated using the Questionnaire d'Activite Physique Saint-Etienne (QAPSE) and expressed using two QAPSE activity indices: mean habitual daily energy expenditure (MHDEE) and daily energy expenditure corresponding to leisure time sports activities (sports activity). The subjects' P _max and V _opt were measured while they cycled on a friction-loaded non-isokinetic cycle ergometer. P _max was expressed relative to body mass [P _max/kg(W · kg⁻¹)], and relative to the mass of two quadriceps muscles [P _{max /Quadr}(W·kg_Quadr ⁻¹)]. A negative relationship between P _max/kg (Spearman's r = −0.56; P < 0.01), P _max/Quadr (r = −0.53; P < 0.01) and V _opt (r = −0.45; P < 0.05) and age was found. P _max/kg was positively associated with MHDEE (r = 0.51; P < 0.01) and sports activity (r = 0.58; P < 0.01), as were P _max/Quadr and V _opt (r = 0.55; P < 0.01 and r = 0.54; P < 0.01, respectively). P _max/kg, P _max/Quadr and V _opt correlated positively with V˙O_2max. The positive relationship between ergometer measurements and PA indices was similar to that between V˙O_2max and PA. P _max/kg was, moreover, closely related to V _opt (r = 0.77; P < 0.001). When a multiple stepwise regression analysis was used to select the variables influencing ergometer measurements, MHDEE contributed significantly to P _max/kg variance, whereas sports activity contributed to P _max/Quadr and V _opt variances. In conclusion, the data from this cross-sectional study suggest that in healthy elderly women habitual PA, and especially leisure time PA, alleviates the decline of the P _max of the quadriceps muscles. Accepted: 30 January 1997     

The reproductive traits of brown trout (Salmo trutta fario L.) from the Yadong River, Tibet

Some key aspects of the reproductive strategy of the brown trout (Salmo trutta fario L.) in the Yadong River, Tibet, including spawning season, age at sexual maturity, fecundity and egg size, have been studied. The majority of the samples were less than 215 mm and age ranged from 1 to 4 in both sexes, indicating that the majority of the fish were younger and the pressure by overfishing was high. The spawning periodicity was determined to be between the end of October and January, mainly in November and December. The ratio of male to female brown trout population (1.29:1 with P > 0.05) suggested no sex significant differences, although males were significantly more abundant than females in October (P < 0.0001) on monthly basis. Age and size of males and females at maturity was different and males matured earlier than females. Fecundity was markedly correlated with their body weight (P < 0.001, r = 0.9255), standard length (P < 0.01, r = 0.8879), and gonad weight (P < 0.001, r = 0.9366). The mean size of mature eggs in the spawning season was: 4.0 ± 0.45 mm and tended to increase along with the female spawners size (P < 0.001, r = 0.9641). Further researches about the brown trout population in the Yadong River should be conducted on issues such as artificial reproduction, culture, conservation, management, and restocking.     

Pulvinus activity,leaf movement and leaf water-use efficiency of bush bean (<Emphasis Type="Italic">Phaseplus vulgaris</Emphasis> L.) in a hot environment

Pulvinus activity of Phaseolus species in response to environmental stimuli plays an essential role in heliotropic leaf movement. The aims of this study were to monitor the continuous daily pulvinus movement and pulvinus temperature, and to evaluate the effects of leaf movements, on a hot day, on instantaneous leaf water-use efficiency (WUE_i), leaf gas exchange, and leaf temperature. Potted plants of Phaseolus vulgaris L. var. Provider were grown in Chicot sandy loam soil under well-watered conditions in a greenhouse. When the second trifoliate leaf was completely extended, one plant was selected to measure pulvinus movement using a beta-ray gauging (BRG) meter with a point source of thallium-204 (²⁰⁴Tl). Leaf gas exchange measurements took place on similar leaflets of three plants at an air temperature interval of 33–42°C by a steady-state LI-6200 photosynthesis system. A copper-constantan thermocouple was used to monitor pulvinus temperature. Pulvinus bending followed the daily diurnal rhythm. Significant correlations were found between the leaf-incident angle and the stomatal conductance (R ² = 0.54; P < 0.01), and photosynthesis rate (R ² = 0.84; P < 0.01). With a reduction in leaf-incidence angle and increase in air temperature, WUE_i was reduced. During the measurements, leaf temperature remained below air temperature and was a significant function of air temperature (r = 0.92; P < 0.01). In conclusion, pulvinus bending followed both light intensity and air temperature and influenced leaf gas exchange.     

Iodine Deficiency Among Hypothyroid Patients Living in Jeddah

The objective was to determine the prevalence of iodine deficiency among hypothyroid patients and the effect of dietary goitrogens on indices of iodine and thyroid status. This is a case-control study of 106 subjects who were recruited from King Abdulaziz University Hospital, Jeddah. Blood and urine were collected for serum thyroid hormones, thyroid autoantibodies, thyroglobulin (Tg) and urinary iodine concentration (UIC). Dietary iodine and goitrogenic food intake were assessed by questionnaire. Using World Health Organization (WHO) cutoff values for UIC, both controls and cases were iodine deficient (85% and 83%, respectively). Furthermore, dietary iodine was deficient in 23% of controls and 36% of cases. In cases, there was a positive association between UIC levels and serum thyroid stimulating hormone (r = 0.405, p < 0.01) and a negative association with serum fT₄ (r = −0.358, p < 0.01). Serum Tg antibody titers were also positively associated with dietary iodine (r = 0.328, p < 0.05). Patients with elevated serum autoantibodies had lower UIC and dietary iodine than those with normal serum autoantibodies. UIC was associated with dietary goitrogens including turnip (r = 0.280, p < 0.05) and pine (r = 0.289, p < 0.05) among cases. Iodine deficiency is common and the consumption of dietary goitrogens is high among euthyroid and hypothyroid subjects living in Jeddah.     

Trace Minerals Status and Antioxidant Enzymes Activities in Calves with Dermatophytosis

The aim of this study was to determine the levels of trace minerals Zn, Cu, and Se, the effect of dermatophytosis on the level of thiobarbituric acid reactive substances (TBARS) as an indicator of lipid peroxidation, the status of enzymatic and nonenzymatic antioxidants, and the relationship between the mentioned trace minerals and antioxidant defense system in calves with dermatophytosis. A total of 21 Holstein calves with clinically established diagnosis of dermatophytosis and an equal number of healthy ones were included in this study. Results showed that 81% of mycotic isolates were Trichophyton verrucosum, while 19% were Trichophyton mentagrophytes. The level of Zn, Cu, Se, and glutathione (GSH) and the activity of the antioxidant enzymes, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were significantly (P ≤ 0.05) lower. The plasma level of TBARS was significantly (P ≤ 0.05) higher in dermatophytic calves compared to healthy controls. SOD activity was fairly correlated with serum Cu and positively correlated with serum Zn in healthy control (r = 0.68, P ≤ 0.05; r = 0.58, P ≤ 0.05) and in calves affected with dermatophytosis (r = 0.73, P ≤ 0.05; r = 0.55, P ≤ 0.05), respectively. GSH-Px activity was highly correlated with whole blood selenium (r = 0.78, P ≤ 0.05) in healthy control and dermatophytic subjects (r = 0.76, P ≤ 0.05). Our results demonstrated that in dermatophytosis, the alteration in the antioxidant enzyme activities might be secondary to changes in their cofactor concentrations.     

Zinc,Parity, Infection,and Severe Anemia Among Pregnant Women in Kassla,Eastern Sudan

The study was conducted to investigate determinants (clinical, nutritional, and nonnutritional factors) of anemia among pregnant women in Kassala, eastern Sudan. Sociodemographic characteristics were gathered; serum ferritin, zinc, albumin, and C-reactive protein were measured using different laboratory methods in a cross-sectional study of 250 pregnant women. Of the 250 women, 58.4% had anemia (hemoglobin (HB) <11 g/dl), 6.8% had severe anemia (HB < 7 g/dl), 19.6% had iron deficiency (S-ferritin <15 μg/l), 14.8% had iron deficiency anemia (<11 g/dl and S-ferritin <15 μg/l), and 38% had zinc deficiency (<80 μg/ml). S-albumin, zinc, and ferritin were significantly lower in patients with severe anemia. While age, gestational age, ferritin, and C-reactive protein were not predictors for anemia, primigravidae (OR = 2.7, 95% CI = 1.1–6.7, P = 0.02), low S-albumin (OR = 5.9, 95% CI = 1.4–25.2, P = 0.01), and low S-zinc (OR = 2.6, 95% CI = 1.0–6.6, P = 0.03) were the predictors for anemia. While there was no significant correlation between hemoglobin, S-zinc, and S-ferritin, there was a significant positive correlation between hemoglobin and S-albumin (r = 0.308, P = 0.001) and significant inverse correlation between hemoglobin and C-reactive protein (r = 0.169, P = 0.007). Thus, the role of chronic inflammation and zinc as possible contributing factors to anemia in pregnancy has important implications for the clinical evaluation and treatment of these women.     

Ovarian and Uterine Ultrasonography in <Emphasis Type="Italic">Aotus azarai infulatus</Emphasis>

We evaluated the uterus and ovaries of owl monkeys (Aotus azarai infulatus) via gynecological ultrasound examination. We evaluated the subjects in 2 different time periods. The first period (P1) was characterized by the absence of mating, with daily examinations, during 4 mo (n = 10). At the end of P1, we paired the subjects for 30 d, but without ultrasonographic evaluation. The second period (P2) was characterized by the presence of mating, with examinations once a week, during 7 consecutive months (n = 9). We evaluated the uterus and ovaries in sagittal and transverse scans, using a 5–12 MHz linear array probe. The uterine volume (UV) was directly proportional to the number of previous parturitions. The right ovary volume (RtOV) is greater than the left (LtOV) in P1 and P2. There is a positive correlation (p < 0.05) between the females’ mass, RtOV (r = 0.28) and LtOV (r = 0.16).     

Low Birth Weight and Normal Birth Weight Newborns of Kolkata, India: Comparison of Some Maternal Risk Factors

This study compared several maternal risk factors of low birth weight (LBW) between 204 normal birth weight (NBW) and 133 LBW newborns from Kolkata, India. Based on their birth weight (BW), newborns were classified as LBW (BW < 2.5 kg) and NBW (BW ≥ 2.5 kg). Results revealed that means for maternal age (MA, p < 0.05), gestational age (GA, p < 0.01), hemoglobin (Hb) concentration (p < 0.05), and per capita daily income (PCDI, p < 0.05) were significantly higher among mothers of NBW. Correlation analyses revealed that MA (r = 0.119, p < 0.05), GA (r = 0.583, p < 0.01), PCDI (r = 0.118, p < 0.05), and Hb (r = 0.138, p < 0.05) were significantly positively correlated with BW; PCDI was also significantly positively correlated (r = 0.142, p < 0.01) with Hb. Stepwise regression analyses with BW as the dependent variable revealed that GA (t = 7.915, p < 0.001) and Hb (t = 2.057, p < 0.05) were the most important predictive variables. The effect of Hb, independent of GA, was statistically significant (change in F = 4.231, p < 0.05). Because GA is not modifiable in pregnant women, there is a need to increase Hb levels among pregnant mothers. Most importantly, appropriately targeted preventive strategies, including iron supplementation, need to be implemented for health promotion.     

Effects of resistance training on biomarkers of bone formation and association with red blood cell variables

We previously showed that resistance training significantly increased the red blood cell count (RBC) and hematocrit (Hct) and decreased the mean cell hemoglobin concentration (MCHC) in physically inactive men. Since the enhanced hematopoiesis may result, at least partly, from bone metabolism, the purpose of this study was to further investigate the effect of resistance training on serum bone-specific alkaline phosphatase activity (B-ALP), a biomarker of bone formation, and focus on the relationship between the change in B-ALP from baseline to 20-week follow-up and the corresponding changes in RBC, Hct and MCHC. Seventy-four men aged 20–45 years were randomly assigned to training and control groups. The training group underwent a 20-week progressive resistance training. Fasting blood samples were analyzed for serum B-ALP at baseline, and at 10-week and 20-week follow-up. B-ALP in the control group exhibited no significant change. In contrast, the training group increased its B-ALP from baseline at 10-week and 20-week follow-up (both P < 0.01 compared to control group). Within the training group, B-ALP was elevated at 10-week and 20-week follow-up when compared to baseline (both P < 0.001). A significant correlation was found between change in B-ALP from baseline to 20-week follow-up and the corresponding changes in RBC, Hct and MCHC in the training group (r = 0.49, P < 0.01; r = 0.56, P < 0.01, and r = −0.38, P < 0.05, respectively). We concluded that resistance training increased biomarkers of bone formation, which had association with RBC turnover. Adaptive changes of bone metabolism induced by resistance training might facilitate erythropoiesis.     

Relationship Between Serum Calcium and Magnesium Concentrations and Metabolic Syndrome Diagnostic Components in Middle-Aged Korean Men

It is thought that calcium and magnesium may be related to metabolic disorders such as obesity and metabolic syndrome; however, to date, there have been few studies investigating the association between serum calcium and magnesium levels and metabolic syndrome in middle-aged male adults. We aimed to investigate the association between serum calcium and magnesium levels and metabolic syndrome in Korean middle-aged male adults. Study subjects included 213 men aged 30∼60 years. MetS risk score is determined by adding the number of risk factors, waist circumference, triacylglyceride (TG), HDL cholesterol, glucose, and blood pressure (BP). The study population was divided into three groups according to the MetS risk score: group I (MetS risk score ≤1; n = 106), group II (MetS risk score = 2; n = 51), and group III (MetS risk score ≥3; n = 56). The serum Ca, according to increase of MetS risk score, was significantly higher (p < 0.001), and there was no significant difference in serum Mg concentration among the three groups. Subjects with high TG and high BP had higher serum calcium levels than those without such abnormalities. Subjects with higher glucose had lower serum magnesium levels than those without such abnormality. The correlation analysis indicated that the serum Ca had positive correlations with the MetS risk score (r = 0.1769, p < 0.01), serum TG (r = 0.2516, p < 0.001), and DBP (r = 0.2246, p < 0.01). The correlation analysis indicated that the serum Mg had an inverse relationship with serum glucose (r = −0.2404, p < 0.001). In conclusion, serum Ca had positive association with TG and BP, while serum Mg had negative association with serum glucose after adjusting age and BMI among the middle-aged Korean male adults.     

Serum heat shock protein 27 antigen and antibody levels appear to be related to the macrovascular complications associated with insulin resistance: a pilot study

Heat shock protein 27 (Hsp27) is over-expressed when cells are exposed to stressful conditions that include oxidative stress. Oxidative stress has been implicated in the pathogenesis of cardiovascular disease (CVD), diabetes and insulin resistance. We have investigated the concentrations of serum Hsp27 antigen and antibodies in subjects from different glycaemic categories, who either did or did not have established CVD. Serum Hsp27 antigen and antibody levels (immunoglobulins M and G (IgM and IgG)) were determined by enzyme-linked immunosorbent assays (ELISAs) in 68 individuals: 26 with normal glucose tolerance (NGT), 10 with (+) and 16 without (−) a history of CVD and 42 individuals with varying degrees of glucose intolerance (GI; 21 with and 21 without a history of CVD). Insulin sensitivity was determined in each subject using indices derived from the homeostasis model assessment of sensitivity and the insulin sensitivity index for glycaemia. Serum Hsp27 concentrations were significantly higher in GI (+CVD) subjects compared to GI (−CVD) subjects (p = 0.03), NGT (−CVD) subjects (p = 0.02) and NGT (+CVD) subjects (p = 0.04) and were positively correlated to fasting plasma glucose for all subjects (r = 0.28, p = 0.03). IgM antibody levels were significantly higher in GI (+CVD) subjects compared to NGT (−CVD) group (p = 0.02) and were inversely related to fasting insulin concentrations (r = −0.27, p = 0.04) and the 2-h insulin concentrations (r = −0.29, p = 0.03) for all subjects. Serum IgG antibody levels were higher in GI (+CVD) group compared to GI (−CVD) group (p = 0.06). In conclusion, Hsp27 and its antibody concentrations appear to relate to the presence of cardiovascular complications in patients with GI.     

Decreased pulmonary diffusing capacity of divers over a 6-year period

Non-smoking, male, professional firemen divers (n = 15) underwent two pulmonary function tests (PFT) separated by 6 years. Measured data were compared to European Coal Steel Community recommended reference values to permit cross-sectional and then longitudinal study. Higher vital capacity (VC; P < 0.01) and forced expiratory volume in 1 s (FEV₁; P < 0.05), and lower maximal mid-expiratory flow (MMEF) coefficient with VC (MMEF/VC; P < 0.05) were observed in both PFT. Diver's pulmonary diffusing capacity (DL_CO) and the coefficient with alveolar volume (DL_CO/V _A) showed significantly (P < 0.001) different evolution profiles than those expected from predicted values. In divers, DL_CO and DL_CO/V _A decreased from 104.0% to 91.4% and from 106.4% to 91.5% of predicted values respectively. Changes in DL_CO and DL_CO/V _A correlated positively with the initial measurement of DL_CO (r = 0.67, P < 0.01) and DL_CO/V _A (r = 0.74, P < 0.01) respectively, whereas no correlation between changes in pulmonary gas transfer function and age or diving history parameters was found. Thus, it is suggested from our observations that hyperbaric atmosphere exposure increases the effects of aging on pulmonary diffusing capacity and that pulmonary gas transfer function should be regularly tested in professional and recreational divers. Accepted: 22 February 1997     

Noninvasive skeletal muscle lactate detection between periods of intense exercise in humans

We investigated whether localized ¹H nuclear magnetic resonance spectroscopy (NMRS) using stimulated echoes (STEAM) with a long mixing time (t _m) allowed the suppression of the fat signal and detection of lactate in skeletal muscle. The ¹H NMRS sequence was first validated in three isolated and perfused rabbit biceps brachii muscles. Spectra were obtained on a wide-bore spectrometer using a dual-tuned probe (¹H and ³¹P). Death was simulated by ceasing the muscle perfusion, which allowed post-mortem changes to be followed. During and after the simulated death, changes in levels of pH and in content of energy-rich compounds were observed with ³¹P NMRS. Our results showed an inverse linear relationship between pH and lactate in each of the three rabbits (r = 0.93, P < 0.001; r = 0.92, P < 0.01; r = 0.89, P < 0.01) and a decrease in phosphocreatine and concomitant increase in lactate. We then investigated whether this sequence allowed repeated detection of lactate in human soleus muscle during the recovery between periods of intense exercise (force-velocity test, F-v test). Seven subjects mean age 25.1 (SEM 0.8) years participated in this study. Soleus muscle lactate was detected at rest and for 3 min 30 s of the 5-min recovery between periods using a 2.35-T 40-cm bore magnet spectrometer. Arm venous plasma lactate concentration was measured at rest, during the F-v test when the subject stopped pedalling (S₁), and at the end of each 5-min recovery between periods (S₂). Results showed that the venous plasma lactate concentration at S₁ and S₂ increased significantly from the beginning of the F-v test to peak anaerobic power (W _an,peak) (P < 0.001). The spectra showed that muscle lactate resonance intensity rose markedly when W _an,peak was achieved. The muscle lactate resonance intensity plotted as a percentage of the resting value increased significantly at W _an,peak compared with submaximal braking forces (P < 0.05). We concluded from these results that localized ¹H NMRS using STEAM with a long t _m allows suppression of the fat signal and repeated detection of lactate on isolated perfused skeletal muscle in animals and between periods of intense exercise in humans. Accepted: 19 January 1998     

Foliage litter quality and annual net N mineralization: comparison across North American forest sites

The feedback between plant litterfall and nutrient cycling processes plays a major role in the regulation of nutrient availability and net primary production in terrestrial ecosystems. While several studies have examined site-specific feedbacks between litter chemistry and nitrogen (N) availability, little is known about the interaction between climate, litter chemistry, and N availability across different ecosystems. We assembled data from several studies spanning a wide range of vegetation, soils, and climatic regimes to examine the relationship between aboveground litter chemistry and annual net N mineralization. Net N mineralization declined strongly and non-linearly as the litter lignin:N ratio increased in forest ecosystems (r ² = 0.74, P < 0.01). Net N mineralization decreased linearly as litter lignin concentration increased, but the relationship was significant (r ² = 0.63, P < 0.01) only for tree species. Litterfall quantity, N concentration, and N content correlated poorly with net N mineralization across this range of sites (r ² < 0.03, P = 0.17–0.26). The relationship between the litter lignin:N ratio and net N mineralization from forest floor and mineral soil was similar. The litter lignin:N ratio explained more of the variation in net N mineralization than climatic factors over a wide range of forest age classes, suggesting that litter quality (lignin:N ratio) may exert more than a proximal control over net N mineralization by influencing soil organic matter quality throughout the soil profile independent of climate. Received: 16 December 1996 / Accepted: 8 February 1997     

Muscle strength and soft tissue composition as measured by dual energy x-ray absorptiometry in women aged 18–87 years

Dual energy x-ray absorptiometry (DEXA) offers the possibility of assessing regional soft tissue composition, i.e. lean mass (LM) and fat mass : LM may be considered a measure of muscle mass. We examined age-related differences in LM, percentage fat (%fat) and muscle strength in 100 healthy non-athletic women aged 18–87 years. Relationships between muscle strength and leg LM in 20 elite female weight lifters and in 18 inactive women with previous hip fractures were also studied. The LM and %fat of the whole body, trunk, arms and legs were derived from a whole body DEXA scan. Isokinetic knee extensor strength (KES) and flexor strength (KFS) at 30° · s^–1 were assessed using an isokinetic dynamometer. The women aged 71–87 years had 35% lower KES and KFS than the women aged 18–40 years (P < 0.0001). Differences in LM were less pronounced. The LM of the legs, for instance, was 15% lower in the old than in the young women (P < 0.0001). In a multiple regression analysis with age, body mass, height and leg LM or KES as independent variables and KES or leg LM as the dependent variable, age was the most important predictor of KES (r _partial = −0.74, P < 0.0001). The same applied to KFS. Body mass, not age, was the most important predictor of leg LM (r _partial = 0.65, P < 0.0001) and of LM at all other measurement sites. The LM measured at different regions decreased equally with increasing age. The KES:leg LM ratio was negatively correlated with age (r = −0.70, P < 0.0001). The weight lifters had significantly higher KES:leg LM ratios than age-matched controls (+12%, P < 0.0001) and vice versa for the women with previous hip fractures (–36%, P < 0.0001). In conclusion, from our study it would seem that in healthy nonathletic women, age is a more important determinant of muscle strength than is LM as measured by DEXA. Muscle strengthening exercises and inactivity seem to have a considerably stronger influence on muscle strength than on LM. Accepted: 27 August 1996     

Effects of contraction duration on low-frequency fatigue in voluntary and electrically induced exercise of quadriceps muscle in humans

The aims of this study were to investigate if low-frequency fatigue (LFF) dependent on the duration of repeated muscle contractions and to compare LFF in voluntary and electrically induced exercise. Male subjects performed three 9-min periods of repeated isometric knee extensions at 40% maximal voluntary contraction with contraction plus relaxation periods of 30 plus 60 s, 15 plus 30 s and 5 plus 10 s in protocols 1, 2 and 3, respectively. The same exercise protocols were repeated using feedback-controlled electrical stimulation at 40% maximal tetanic torque. Before and 15 min after each exercise period, knee extension torque at 1, 7, 10, 15, 20, 50 and 100 Hz was assessed. During voluntary exercise, electromyogram root mean square (EMG_rms) of the vastus lateralis muscle was evaluated. The 20-Hz torque:100-Hz torque (20:100 Hz torque) ratio was reduced more after electrically induced than after voluntary exercise (P < 0.05). During electrically induced exercise, the decrease in 20:100 Hz torque ratio was gradually (P < 0.05) reduced as the individual contractions shortened. During voluntary exercise, the decrease in 20:100 Hz torque ratio and the increase in EMG_rms were greater in protocol 1 (P < 0.01) than in protocols 2 and 3, which did not differ from each other. In conclusion, our results showed that LFF is dependent on the duration of individual muscle contractions during repetitive isometric exercise and that the electrically induced exercise produced a more pronounced LFF compared to voluntary exercise of submaximal intensity. It is suggested that compensatory recruitment of faster-contracting motor units is an additional factor affecting the severity of LFF during voluntary exercise. Accepted: 5 November 1997     

Study on Blood Biochemical Diagnostic Indices for Hepatic Function Biomarkers in Endemic Skeletal Fluorosis

The aim of the study was to determine the relationship of fluoride in drinking water to liver function in individuals living in normal and seven endemic fluorosis areas of Punjab, India. The concentration of fluoride in drinking water of different areas varied from 5.9 to 24.5 mg/L. Study group consisted of 705 patients in the age group between 20 and 60 years (mean age of 39.35 ± 11.27) affected with osteodental fluorosis were compared with 300 age- and sex-matched controls (with mean age of 35.28 ± 8.25 years). Biochemical data was analyzed by one-way analysis of variance (ANOVA) with post hoc Tukey–Kramer and Bonferroni multiple comparison tests. The relationship between hepatic enzymes was calculated by Pearson’s correlation and linear regression. The results revealed significantly (P < 0.001) higher concentration of serum fluoride in patients when compared to control. The mean activities of cyclic adenosine monophosphate (AMP), alkaline phosphatase (ALKP), acid phosphatase (ACP), aspartate aminotransaminase (AST), and alanine aminotransaminase (ALT) were significantly (P < 0.05–0.001) elevated in patients from all fluoride areas. ANOVA with post hoc Turkey–Kramer and Bonferroni multiple comparison test demonstrated a significant (P < 0.0001) variance in the activities of cAMP, ALKP, ACP, AST, and ALT in fluorotic patients, with elevation in water fluoride levels. Maximum elevation of 196.14% (ACP), 99.31% (cyclic adenosine monophosphate; cAMP), 72.08% (ALT), 60.14% (AST), and least 21.35% (ALKP) was recorded in patients exposed to 24.5 mg/L fluoride in drinking water. There was positive correlation between water fluoride, serum fluoride and AST (r = 0.77, 0.91), ALT (r = 0.82, 0.90), ALKP (r = 0.88, 0.97), and ACP (r = 0.74, 0.85). Pearson’s correlation demonstrated highly significant (P < 0.05) positive relationship between water fluoride and cAMP (regression equation: Y = 0.9807 ×+ 22.081 Y = 0.9807 \times + 22.081 , = 0.84; r = 0.92, P < 0.05). The increased levels of transaminases in fluorotic patients suggest alteration in liver functions. The level of alkaline and acid phosphatase was increased during fluoride intoxication which is also an early marker of hepatic cell damage because of its specificity and catalytic activity. The elevated levels of enzymes are reflective of bone disorders, which are characterized by increased osteoblastic activity. There levels increased several times if cellular damage occurs in the liver. The results suggest that fluoride exposure intensifies the activities of hepatic function enzymes in osteofluorosis.     

Mineral Factors Controlling Essential Hypertension—a Study in the Chandigarh, India Population

Essential hypertension (EH) is a major public health problem world over and in India. Recent data on EH in the population of Chandigarh (Union Territory and capital of Punjab and Haryana States of India) revealed that the prevalence of EH has become double in the last 30 years in the residents of Chandigarh (26.9 to 45.80% in the year 1968 and 2002). Zinc (Zn), copper (Cu), magnesium (Mg), and manganese (Mn) in the serum are considered important in maintaining the human hypertension. The high Zn intake was considered to increase the blood pressure (BP) and to affect the other mineral status in the body. Recent survey on the trace metal status of different vegetables in the State of Punjab around Chandigarh (India) revealed that Zn level is significantly higher (40 mg/kg or more in above ground vegetables and 120 mg/kg or above in underground vegetables) in underground water-irrigated vegetables, but the levels of Cu and Mg are within prescribed limit. The present study was conducted on Chandigarh population to evaluate the levels of Zn, Cu, Mg, and Mn in the blood and urine of normotensive (NT) control and hypertensive (HT) subjects matched with number, age and sex. Atomic absorption spectrophotometer studies revaluated that the levels of serum Zn, Mg, and Mn were significantly higher (p < 0.001), but the level of Cu was low in the HT subjects (BP = 160/93) compared to NT control (BP = 140/83). Higher levels of urinary Zn, Cu, Mg, and Mn were observed in the HT subject vs NT control (p < 0.001). Positive correlations were evaluated between the levels of serum Zn, Mg, and Mn vs systolic and diastolic pressures (DP and SP), respectively (r = 0.928, 0.863, 0.876, 0.808, 0.404, 0.326, p < 0.01), but negative and positive nonsignificant correlations between the serum Cu with SP and DP were recorded (r = −0.032, r = 0.024). Positive correlations were also evaluated between urinary levels of Zn, Cu, Mg, and Mn vs SP and DP (r = 0.718, 0.657, 0.750, 0.681, 0.630, 0.578, 0.516, 0.461, p < 0.01). Prevalence of essential hypertension may be due to higher Zn level in the food chain that makes the individuals vulnerable to other diseases over the time related to essential hypertension.     

The Content of Elements in Rainwater and its Relation to the Frequency of Hospitalization for Diabetes and Obesity in Opole Voivodship,Poland, During 2000–2002

Environmental factors significantly influence the incidence and course of metabolic syndrome diseases such as diabetes and obesity. The content of elements in rainwater is an indirect indicator of their presence in dust suspended in the air. In this paper we present the relationships between the content of selected elements in rainwater and hospitalization frequencies due to diabetes (E10–E13) and obesity (E66). It was assumed that the hospitalization frequency could be taken as a measure of deterioration of the metabolic process in the course of diabetes and its complications. The observations concerned the population of Opole Voivodeship, Poland (one million inhabitants), distributed in small communities of 44,000 to 151,000 inhabitants during the years 2000–2002. In cases of diabetes E10–E13 for all subjects relevant correlation indicators were found for chromium (r = 0.71), cadmium (r = 0.65), and lead (r = 0.66). Borderline relevance was seen for copper (r = 0.57) and zinc (r = 056). For diabetic men the statistically relevant correlations were chromium (r = 0.79), lead (r = 0.77), cadmium (r = 0.74), copper (r = 0.70), chloride (r = 0.69), zinc (r = 0.68), and iron (r = 0.64). For women the only relevant correlations were chromium (r = 0.62) and cadmium (r = 0.55). No significant correlations were found in obese individuals of both sexes.