Changes of enzyme activities in ovine fetal fluids and maternal blood serum with gestational age

Our objectives were threefold: (1) to assess the activities of tissue enzymes, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and creatine kinase (CK) in the fetal fluids (amniotic and allantoic) collected from the gravid sheep uteri obtained from the abattoir and also in the maternal blood serum at various stages of pregnancy, (2) to compare the enzyme activities of fetal fluids relative to the maternal serum, and (3) to compare the enzyme activities in serum of pregnant ewes to nonpregnant ones. The stages of gestation, viz., stage I (30–60 days), stage II (61–90 days), and stage III (91–120 days) were identified based on the crown anus length of the fetus. As the gestational ages increased, AST significantly (p < 0.01) increased in the amniotic fluid and maternal blood serum but decreased in allantoic fluid; ALT had no changes in fetal fluids and the maternal blood serum; ALP decreased significantly (p < 0.01) in allantoic fluid but had no changes in the amniotic fluid and maternal serum; LDH increased significantly (p < 0.01) in amniotic and allantoic fluids but decreased in maternal serum; CK decreased significantly (p < 0.01) in fetal fluids and maternal serum. The enzyme activities were significantly higher in maternal sera than fetal fluids but were successively less in allantoic and amniotic fluids (p < 0.01). The activity of enzymes in maternal sera of pregnant and nonpregnant ewes were nearly the same. Except for LDH and CK, the greatest activities were found in the maternal serum in stage I and for AST in stage III of pregnancy (p < 0.01). These findings may have appreciable diagnostic significance in prenatal detection of disease status in both the dam and the fetus.     

Comparison of serum enzyme activity in great sturgeon, Huso huso, cultured in brackish and freshwater earth ponds in Iran

Blood samples were collected from 60 great sturgeons, Huso huso, to establish the following serum enzyme activity: aspartate amino-transferase (AST), alanine amino-transferase (ALT), lactic acid dehydrogenase (LDH), creatine kinase (CK), and alkaline phosphatase (ALP) using an autoanalyzer, and acid phosphatase (ACP) by manual method. Thirty 5-year-old cultured fish were caught from each of two sites; a brackish-water earth pond in Bafgh and a freshwater pond in Gorgan in the centre and northeast of Iran, during May 2006. Results of the serum enzymes activity for H. huso samples from Bafgh and Gorgan were: AST, 502.9 ± 258.2 and 436.1 ± 186.8; ALT, 104.4 ± 35.1 and 53.1 ± 38.7; LDH, 3094.2 ± 1277.5 and 2486.3 ± 1393.3; CK, 3632.9 ± 2618.7 and 3967 ± 5054.9; ALP, 281.2 ± 112.7 and 762.2 ± 600.2; ACP, 13.3 ± 2.5 and 33 ± 6.8 IU/L. Mean values of ALT, ALP and ACP were significantly different in the fish from the two sites (p < 0.05). These results may be used to understand some biological (e.g., serum enzyme activity) and ecological characteristics of cultured H. huso.     

Simulated moderate altitude elevates serum erythropoietin but does not increase reticulocyte production in well-trained runners

The purpose of this study was to investigate whether the modest increases in serum erythropoietin (sEpo) experienced after brief sojourns at simulated altitude are sufficient to stimulate reticulocyte production. Six well-trained middle-distance runners (HIGH, mean maximum oxygen uptake, V˙O_2max = 70.2 ml · kg⁻¹ · min⁻¹) spent 8–11 h per night for 5 nights in a nitrogen house that simulated an altitude of 2650 m. Five squad members (CONTROL, mean V˙O_2max = 68.9 ml · kg⁻¹ · min⁻¹) undertook the same training, which was conducted under near-sea-level conditions (600 m altitude), and slept in dormitory-style accommodation also at 600 m altitude. For both groups, this 5-night protocol was undertaken on three occasions, with a 3-night interim between successive exposures. Venous blood samples were measured for sEpo after 1 and 5 nights of hypoxia on each occasion. The percentage of reticulocytes was measured, along with a range of reticulocyte parameters that are sensitive to changes in erythropoiesis. Mean serum erythropoietin levels increased significantly (P < 0.01) above baseline values [mean (SD) 7.9 (2.4) mU · ml⁻¹] in the HIGH group after the 1st night [11.8 (1.9) mU · ml⁻¹, 57%], and were also higher on the 5th night [10.7 (2.2) mU · ml⁻¹, 42%] compared with the CONTROL group, whose erythropoietin levels did not change. After athletes spent 3 nights at near sea level, the change in sEpo during subsequent hypoxic exposures was markedly attenuated (13% and −4% change during the second exposure; 26% and 14% change during the third exposure; 1st and 5th nights of each block, respectively). The increase in sEpo was insufficient to stimulate reticulocyte production at any time point. We conclude that when daily training loads are controlled, the modest increases in sEpo known to occur following brief exposure to a simulated altitude of 2650 m are insufficient to stimulate reticulocyte production. Accepted: 7 October 1999     

Effects of heavy resistance training on maximal and explosive force production, endurance and serum hormones in adolescent handball players

To determine the effects of 6-weeks of heavy-resistance training on physical fitness and serum hormone status in adolescents (range 14–16 years old) 19 male handball players were divided into two different groups: a handball training group (NST, n = 10), and a handball and heavy-resistance strength training group (ST, n = 9). A third group of 4 handball goalkeepers of similar age served as a control group (C, n = 4). After the 6-week training period, the ST group showed an improvement in maximal dynamic strength of the leg extensors (12.2%; P < 0.01) and the upper extremity muscles (23%; P < 0.01), while no changes were observed in the NST and C groups. Similar differences were observed in the maximal isometric unilateral leg extension forces. The height of the vertical jump increased in the NST group from 29.5 (SD 4) cm to 31.4 (SD 5) cm (P < 0.05) while no changes were observed in the ST and C groups. A significant increase was observed in the ST group in the velocity of the throwing test [from 71.7 (SD 7) km · h⁻¹ to 74.0 (SD 7) km · h⁻¹; P < 0.001] during the 6-week period while no changes were observed in the NST and C groups. During a submaximal endurance test running at 11 km · h⁻¹, a significant decrease in blood lactate concentration occurred in the NST group [from 3.3 (SD 0.9) mmol · l⁻¹ to 2.4 (SD 0.8) mmol · l⁻¹; P < 0.01] during the experiment, while no change was observed in the ST or C groups. Finally, a significant increase (P < 0.01) was noted in the testosterone:cortisol ratio in the C group, while the increase in the NST group approached statistical significance (P < 0.08) and no changes in this ratio occurred in the ST group. The present findings suggested that the addition of 6-weeks of heavy resistance training to the handball training resulted in gains in maximal strength and throwing velocity but it compromised gains in leg explosive force production and endurance running. The tendency for a compromised testosterone:cortisol ratio observed in the ST group could have been associated with a state of overreaching or overtraining. Accepted: 22 April 1999     

Austrian Moderate Altitude Study (AMAS 2000) - fluid shifts,erythropoiesis, and angiogenesis in patients with metabolic syndrome at moderate altitude (congruent with 1700 m)

It was hypothesized that subjects with metabolic syndrome (hypertension, obesity, hyperlipidemia, diabetes mellitus): (1) develop measurable peripheral edema at moderate altitude and (2) might show differences on erythropoiesis, iron status and vascular endothelial growth factor (VEGF) in comparison to healthy subjects during and after a long-term stay (3-week exposure) at moderate altitude (≅1700 m). Twenty-two male subjects with metabolic syndrome were selected. Baseline investigations (t1) were performed in Innsbruck (500 m). All participants were transferred by bus to 1700 m (Alps) and remained there for 3 weeks with examinations on day 1 (after the first night at altitude, t2), day 4 (t3), day 9 (t4) and day 19 (t5). After returning to Innsbruck, post-altitude examinations were conducted after 7–10 days (t6) and 6–7 weeks (t7), respectively. Body mass was decreased from t1 to t7 (P<0.01). Total body water was decreased at t2 (P<0.01), returned to control level (t3, t4), and was found elevated at t7 (P<0.01). Lean body mass did not change, but body fat decreased during the study (P<0.01). Tissue thickness at the forehead decreased during and after altitude exposure (P<0.01), whereas tissue thickness at the tibia did not alter. Erythropoietin (EPO) was elevated as early as t2 and remained increased until t5. Reticulocyte count was increased at t3 and remained above pre-altitude values. VEGF levels were unchanged. After a 3-week exposure to moderate altitude, patients with metabolic syndrome had reduced their body mass, mainly because of a reduction in body fat. The moderate altitude was found to stimulate erythropoiesis in these patients but this was not sufficient to increase serum VEGF concentration. Electronic Publication     

Alterations in the expression and activity of creatine kinase-M and mitochondrial creatine kinase subunits in skeletal muscle following prolonged intense exercise in rats

Creatine kinase (CK) isoenzymes are important structural and energy metabolism components in skeletal muscle. In this study, CK isoenzyme alterations were examined in male rats, with an 8% body mass weight attached to their tail. The rats were either forced to swim for 5 h (5S, n = 51), or were pre-trained for 8 days and then forced to swim for 5 h (T5S, n = 48). Rats were sacrificed either immediately (0 h PS), 3 h (3 h PS), or 48 h post-swimming (48 h PS). Serum CK was increased significantly (P < 0.01) 6.2- and 2.0-fold at 0 h PS following the 5S and T5S protocols, respectively. However, training (T5S protocol) significantly (P < 0.01) decreased CK release. Soleus and white gastrocnemius (WG) CK activity was significantly decreased following the 5S protocol (P < 0.05), but not following the T5S protocol. The CK-M activity of the soleus muscle was significantly (P < 0.05) decreased at 0 h PS following both the 5S and T5S protocols, and returned to control values at 3 h PS. The CK-M activity of the WG was significantly (P < 0.05) decreased at 0 h PS following the 5S protocol. Sarcomeric mitochondrial CK (sCK-Mit) was decreased significantly (P < 0.01) at 0 h PS (20%), 3 h PS (14%), 24 h PS (22%), and 48 h PS (15%) following the 5S protocol. However, sCK-Mit was decreased significantly (P < 0.01) only at 0 h PS (7%) following the T5S. The results of this study demonstrate that prolonged intense exercise causes a loss of skeletal muscle CK-M and sCK-Mit activity and that training prior to the prolonged intense exercise attenuates the exercise-induced CK-M and sCK-Mit loss in both red and white skeletal muscles. Accepted: 18 July 1999     

Hypoxemia increases serum interleukin-6 in humans

 Serum concentrations of interleukin (IL) 1 beta, IL-1 receptor antagonist (IL-1ra), IL-6, tumor necrosis factor (TNF) alpha, and C-reactive protein (CRP) were determined in ten healthy men at sea level and during four days of altitude hypoxia (4350m above sea level). The mean (SD) arterial blood oxygen saturations were 78.6 (7.3)%, 82.4 (4.9)%, and 83.4 (5.3)% in the first, second, and third days at altitude, respectively. A symptom score of acute mountain sickness (AMS) revealed that the subjects had mostly light symptoms of AMS. Mean serum IL-6 increased from 1.36 (1.04) pg × ml^–1 at sea level to 3.10 (1.65), 4.71 (2.81), and 3,54 (2.17) pg × ml^–1 during the first three days at altitude, and to 9.96 (8.90) pg × ml^–1 on the fourth day at altitude (ANOVA p =0.002). No changes occurred in serum concentrations of IL-1 beta, IL-1ra, TNF alpha, or CRP. The serum IL-6 were related to SaO₂, ( r =–0.45, p =0.003), but not to heart rates or AMS scores. In conclusion, human serum concentrations of IL-6 increased during altitude hypoxia whereas the other proinflammatory cytokines remained unchanged. The major role of IL-6 during altitude hypoxia seem not to be mediation of inflammation, instead, the role of IL-6 could be to stimulate the erythropoiesis at altitude. Accepted: 30 May 1997     

Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in middle-aged and elderly people

Effects of a 24-week strength training performed twice weekly (24 ST) (combined with explosive exercises) followed by either a 3-week detraining (3 DT) and a 21-week re-strength-training (21 RST) (experiment A) or by a 24-week detraining (24 DT) (experiment B) on neural activation of the agonist and antagonist leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris, maximal isometric and one repetition maximum (1-RM) strength and jumping (J) and walking (W) performances were examined. A group of middle-aged (M, 37–44 years, n=12) and elderly (E, 62–77, n=10) and another group of M (35–45, n=7) and E (63–78, n=7) served as subjects. In experiment A, the 1-RM increased substantially during 24 ST in M (27%, P < 0.001) and E (29%, P < 0.001) and in experiment B in M (29%, P < 0.001) and E (23%, P < 0.01). During 21 RST the 1-RM was increased by 5% at week 48 (P < 0.01) in M and 3% at week 41 in E (n.s., but P < 0.05 at week 34). In experiment A the integrated electromyogram (IEMG) of the vastus muscles in the 1-RM increased during 24 ST in both M (P < 0.05) and E (P < 0.001) and during 21 RST in M for the right (P < 0.05) and in E for both legs (P < 0.05). The biceps femoris co-activation during the 1-RM leg extension decreased during the first 8-week training in M (from 29 ± 5% to 25 ± 3%, n.s.) and especially in E (from 41 ± 11% to 32 ± 9%, P < 0.05). The CSA increased by 7% in M (P < 0.05) and by 7% in E (P < 0.001), and by 7% (n.s.) in M and by 3% in E (n.s.) during 24 ST periods. Increases of 18% (P < 0.001) and 12% (P < 0.05) in M and 22% (P < 0.001) and 26% (P < 0.05) in E occurred in J. W speed increased (P < 0.05) in both age groups. The only decrease during 3 DT was in maximal isometric force in M by 6% (P < 0.05) and by 4% (n.s.) in E. During 24 DT the CSA decreased in both age groups (P < 0.01), the 1-RM decreased by 6% (P < 0.05) in M and by 4% (P < 0.05) in E and isometric force by 12% (P < 0.001) in M and by 9% (P < 0.05) in E, respectively, while J and W remained unaltered. The strength gains were accompanied by increased maximal voluntary neural activation of the agonists in both age groups with reduced antagonist co-activation in the elderly during the initial training phases. Neural adaptation seemed to play a greater role than muscle hypertrophy. Short-term detraining led to only minor changes, while prolonged detraining resulted in muscle atrophy and decreased voluntary strength, but explosive jumping and walking actions in both age groups appeared to remain elevated for quite a long time by compensatory types of physical activities when performed on a regular basis. Accepted: 2 May 2000     

Changes in hardness of the human elbow flexor muscles after eccentric exercise

The purpose of this study was to investigate changes in muscle hardness after eccentric exercise of the elbow flexors muscles that produce muscle shortening and swelling. To assess muscle hardness, a pressure method was used in which the force required to deform the tissue (skin, subcutaneous tissue, muscle) was recorded. Eleven healthy male students performed 24 maximal eccentric actions of the elbow flexor muscles with their non-dominant arms. Muscle hardness, maximal isometric force (MIF), muscle soreness, plasma creatine kinase (CK) activity, relaxed elbow joint angle (RANG), upper-arm circumference (CIR) and B-mode ultrasound transverse images were measured before, immediately after, and 1–5 days after exercise. A long-lasting decrease in MIF, muscle swelling shown by increases in CIR and muscle thickness, large increases in plasma CK activity, and development of muscle soreness indicated that damage occurred to the elbow flexor muscles. The RANG had decreased by approximately 20° at 1–3 days after exercise and showed a gradual recovery thereafter. The CIR increased gradually after exercise and peaked on day 5 post-exercise, the mean amount of increase in CIR being 18 mm. Muscle hardness measured at the relaxed elbow position did not change until 3 days after exercise, but increased significantly (P < 0.01) on days 4 and 5 post-exercise. On the other hand, muscle hardness measured when forcibly extending the shortened elbow joint increased significantly (P < 0.01) with time and peaked at 3 days after exercise. Muscle hardness assessed by the pressure method seems to reflect changes in muscle stiffness and swelling. Accepted: 15 April 2000     

Strenuous endurance training in humans reduces oxidative stress following exhausting exercise

The aim of this study was to evaluate whether high-intensity endurance training would alleviate exercise-induced oxidative stress. Nine untrained male subjects (aged 19–21 years) participated in a 12-week training programme, and performed an acute period of exhausting exercise on a cycle ergometer before and after training. The training programme consisted of running at 80% maximal exercise heart rate for 60 min · day⁻¹, 5 days · week⁻¹ for 12 weeks. Blood samples were collected at rest and immediately after exhausting exercise for measurements of indices of oxidative stress, and antioxidant enzyme activities [superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT)] in the erythrocytes. Maximal oxygen uptake (V˙O_2max) increased significantly (P < 0.001) after training, indicating an improvement in aerobic capacity. A period of exhausting exercise caused an increase (P < 0.01) in the ability to produce neutrophil superoxide anion (O₂ ^•−) both before and after endurance training, but the magnitude of the increase was smaller after training (P < 0.05). There was a significant increase in lipid peroxidation in the erythrocyte membrane, but not in oxidative protein, after exhausting exercise, however training attenuated this effect. At rest, SOD and GPX activities were increased after training. However, there was no evidence that exhausting exercise enhanced the levels of any antioxidant enzyme activity. The CAT activity was unchanged either by training or by exhausting exercise. These results indicate that high-intensity endurance training can elevate antioxidant enzyme activities in erythrocytes, and decrease neutrophil O₂ ^•− production in response to exhausting exercise. Furthermore, this up-regulation in antioxidant defences was accompanied by a reduction in exercise-induced lipid peroxidation in erythrocyte membrane. Accepted: 26 September 2000     

Biological activity of FGF-23 fragments

The phosphaturic activity of intact, full-length, fibroblast growth factor-23 (FGF-23) is well documented. FGF-23 circulates as the intact protein and as fragments generated as the result of proteolysis of the full-length protein. To assess whether short fragments of FGF-23 are phosphaturic, we compared the effect of acute, equimolar infusions of full-length FGF-23 and various FGF-23 fragments carboxyl-terminal to amino acid 176. In rats, intravenous infusions of full-length FGF-23 and FGF-23 176–251 significantly and equivalently increased fractional phosphate excretion (FE Pi) from 14 ± 3 to 32 ± 5% and 15 ± 2 to 33 ± 2% (p < 0.001), respectively. Chronic administration of FGF-23 176–251 reduced serum Pi and serum concentrations of 1α,25-dihydroxyvitamin D. Shorter forms of FGF-23 (FGF-23 180–251 and FGF-23 184–251) retained phosphaturic activity. Further shortening of the FGF-23 carboxyl-terminal domain, however, abolished phosphaturic activity, as infusion of FGF-23 206–251 did not increase urinary phosphate excretion. Infusion of a short fragment of the FGF-23 molecule, FGF-23 180–205, significantly increased FE Pi in rats and reduced serum Pi in hyperphosphatemic Fgf-23 ^−/− knockout mice. The activity of FGF-23 180–251 was confirmed in opossum kidney cells in which the peptide reduced Na⁺-dependent Pi uptake and enhanced internalization of the Na⁺-Pi IIa co-transporter. We conclude that carboxyl terminal fragments of FGF-23 are phosphaturic and that a short, 26-amino acid fragment of FGF-23 retains significant phosphaturic activity.     

Evaluation of erythrocyte antioxidant mechanisms: antioxidant enzymes, lipid peroxidation, and serum trace elements associated with progressive anemia in ovine malignant theileriosis

Ovine malignant theileriosis is a fatal disease that is characterized by severe progressive anemia. In order to elucidate the underlying mechanisms involved in anemia, this study was designed to assess the antioxidant status and erythrocyte oxidative injuries in Iranian fat-tailed sheep that suffered from malignant theileriosis. The infected animals (infected group), composed of 50 Iranian sheep about 1–2 years old, naturally infected with Theileria sp., were divided into three subgroups according to parasitemia rates (<1%, 1–3%, 3–5%), and ten non-infected animals were also selected as the control group. Blood samples were taken and hematological parameters, the activities of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, erythrocyte osmotic fragility, and serum concentrations of some trace elements (copper, iron, zinc, manganese, and selenium), were measured. As an index of lipid peroxidation, the level of malondialdehyde (MDA) was also determined. According to the results, a significant decrease in red blood cell (RBC) count, packed cell volume, the activities of SOD, GPX, and catalase (P < 0.001), and also serum concentrations of Cu, Zn, Mn, and Se (P < 0.05) were evident in the infected sheep. In contrast, significantly increased levels of MDA and erythrocyte osmotic fragility (P < 0.001) as well as serum concentration of iron (P < 0.05) were recorded in the infected animals. The significant decrease in antioxidant enzyme activities and substantial elevated levels of lipid peroxidation and erythrocyte osmotic fragility associated with the increase in parasitemia indicate increased exposure of RBCs to oxidative damage. Also, it appears that disturbed antioxidant defense mechanisms can promote the development of anemia in ovine theileriosis.     

Preparatory versus main competitions: differences in performances, lactate responses and pre-competition plasma cortisol concentrations in elite male swimmers

Two groups of elite male swimmers were studied using a similar protocol during the winter training seasons of two consecutive years. In the first season (September 1997–January 1998), eight male swimmers (age 19–25 years) of the Italian National Team participated, after 12 weeks of increased training volume, in a preparatory national competition (PWC) and then, after a further 6 weeks of specific training, in the World Championships (WC, both competitions in a 50-m pool), which represented the main competition at the end of the 18-week-long winter season. In the second season (September 1998–December 1998), a group of ten high-level male swimmers (18–22 years) participated, after 8 weeks of increased training volume, in a preparatory national competition (PIC) and then, after a further 6 weeks of specific training, in the Italian Championships (IC, both competitions in a 25-m pool), the main competition at the end of the 14-week-long winter season. A tapering period lasting 1–3 weeks was observed before the main competition in both seasons. All swimmers were competing at distances of up to 400 m; two of them participated in the study in both seasons. The swimming velocities and post-competition blood lactate concentrations were higher in the main competitions than in the preparatory competitions in both seasons. Pre-competition plasma cortisol (CORT) concentrations were higher than the initial values at the beginning of the season, reaching maximal values at the preparatory competitions and then decreasing before the main competitions in both seasons. The percentage increase in individual swimming velocity from the preparatory to the main competition was positively correlated with the corresponding increase in post-competition blood lactate (r=0.63, P=0.046) in the 1997 season (WC), and negatively correlated with the corresponding decrease in pre-competition CORT concentration (r=−0.66, P=0.019) in the 1998 season (IC). Our results indicate that a decrease in pre-competition CORT could be a prerequisite for an improvement in swimming performance. Accepted: 9 March 2000     

Short-term exercise training improves diaphragm antioxidant capacity and endurance

These experiments tested the hypothesis that short-term endurance exercise training would rapidly improve (within 5 days) the diaphragm oxidative/antioxidant capacity and protect the diaphragm against contraction-induced oxidative stress. To test this postulate, male Sprague-Dawley rats (6 weeks old) ran on a motorized treadmill for 5 consecutive days (40–60 min · day⁻¹) at approximately 65% maximal oxygen uptake. Costal diaphragm strips were excised from both sedentary control (CON, n=14) and trained (TR, n=13) animals 24 h after the last exercise session, for measurement of in vitro contraction properties and selected biochemical parameters of oxidative/antioxidant capacity. Training did not alter diaphragm force-frequency characteristics over a full range of submaximal and maximal stimulation frequencies (P > 0.05). In contrast, training improved diaphragm resistance to fatigue as contraction forces were better-maintained by the diaphragms of the TR animals during a submaximal 60-min fatigue protocol (P < 0.05). Following the fatigue protocol, diaphragm strips from the TR animals contained 30% lower concentrations of lipid hydroperoxides compared to CON (P < 0.05). Biochemical analysis revealed that exercise training increased diaphragm oxidative and antioxidant capacity (citrate synthase activity +18%, catalase activity +24%, total superoxide dismutase activity +20%, glutathione concentration +10%) (P < 0.05). These data indicate that short-term exercise training can rapidly elevate oxidative capacity as well as enzymatic and non-enzymatic antioxidant defenses in the diaphragm. Furthermore, this up-regulation in antioxidant defenses would be accompanied by a reduction in contraction-induced lipid peroxidation and an increased fatigue resistance. Accepted: 6 August 1999     

Relationship between CYP2E1 polymorphism and increase of ALT activity during therapy of patients with pulmonary tuberculosis

Association of CYP2E1 polymorphism with ALT activity increase was studied in patients with pulmonary tuberculosis receiving therapy by intermittent and daily protocols. The greatest increment of ALT activity in the group receiving therapy by intermittent protocol was seen in the patients with CYP2E1*7632TA genotype. In patients with wild homozygotic 1 C/1 C (6/6) genotype, ALT activity signifi cantly increased, but remained within the normal range (p = 0.048). In the group on daily regimen, activity of ALT increased signifi cantly in patients with all genotypes identifi ed. A more pronounced elevation surpassing the median of the upper threshold of ALT norm was observed in patients with 7632TA genotype (p = 0.0051) and in patients with 7632TA or -71GT or 1 C/1D genotypes in combinations with wild type alleles by other detected polymorphisms (p = 0.0277). Detection of the CYP2E1 gene 7632 T > A polymorphism was found to be the most informative test for prediction of the hepatotoxic reactions during therapy for tuberculosis.     

Saliva immunoglobulins in elite women rowers

Saliva immunoglobulins (sIgA, sIgG, and sIgM) and upper respiratory tract infection (URTI) rates were evaluated in 20 elite female rowers and 19 nonathletes. Also, the influence of carbohydrate versus placebo beverage consumption on saliva immunoglobulin responses to rowing training sessions was measured in 15 rowers and in 5 non-exercising rowers. Saliva samples were collected 1 day before, and 5–10 min and 1.5 h after rowing or rest. Pre-exercise sIgA (but not sIgG or sIgM) concentration was 77% higher in the rowers compared to nonathletes (P < 0.001). Health records kept over 2 months revealed mean 5.2 (SEM 1.2) and 3.3 (SEM 1.1) days with URTI symptoms for the rowers and controls, respectively. For all 39 subjects, and for the 20 rowers separately, no significant correlation was found between URTI symptoms or insulin, cortisol, and growth hormone concentrations and pre-exercise or exercise-related changes in saliva immunoglobulin concentrations or secretion rates. The patterns of change in saliva immunoglobulin concentration and secretion rate did not differ between the carbohydrate and placebo rowing trials, or between exercised and rested athletes. These data indicated an increased sIgA concentration in the female elite rowers compared to the nonathletes, no association between saliva immunoglobulins and URTI, and no effect of a normal 2-hour training session or carbohydrate ingestion on saliva immunoglobulin concentrations or secretion rates. Accepted: 23 August 1999     

Effect of manganese on thyroid function in sheep

Ten healthy adult male sheep aged about 1 year old were randomly allocated into two equal groups of control (no treatment group, n = 5) and experiment (n = 5). The two groups were kept under the same conditions of food and environment. Sheep of experimental group received MnSO₄, H₂O (5 mg/kg/day, SC) from day 0 for 8 weeks. Blood sampling of the two groups were done on days 0, 14, 28, 42, 56, and 70 at 11 a.m. Serum T4, T3, FT3, FT4, TSH, manganese, creatinine, and blood urea nitrogen concentrations were measured. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and serum alkaline phosphatase (ALP) activities were estimated by conventional methods. Serum and urine GGT activities were also measured. Urine samples were tested by urine dipstick analysis. Results indicated that serum manganese concentration was increased significantly on days 14, 28, 42, 56, and 70 of manganese administration (p < 0.05). The changes in serum enzyme activities ALP, GGT, AST, ALT, and urea and creatinine concentrations during these days were not significant. Changes of urine GGT activity were not significant. Serum TSH, FT3, FT4, T3, and T4 concentrations decreased differently on days 14, 28, 42, and 56 (p < 0.05). Urinalysis by urine dipstick analysis was normal.     

Association between serum cortisol and progesterone concentrations and the infiltration of immune cells in the endometrium of gilts with vaginal discharge

The objective of the study was to investigate an association between serum cortisol and progesterone (P₄) concentrations and the distribution of immune cells in the endometrium of the gilts with vaginal discharge. Genital organs from 39 Landrace×Yorkshire crossbred gilts culled owing to vaginal discharge problem were collected from two commercial swine herds in Thailand. The estrous stage and gross pathology were examined. Blood samples were collected from the jugular vein prior to being slaughtered. Serum P₄ and cortisol were analyzed by means of enzyme immunoassay. The samples observed were in inactive (n = 4), follicular (n = 10), and luteal (n = 25) phases. They, afterwards, were processed in hematoxylin and eosin sections. The endometrium of the gilts was histologically divided into three layers, i.e., epithelial, subepithelial connective tissue, and glandular connective tissue layers. Immune cells, i.e., lymphocytes, neutrophils, eosinophils, macrophages, and plasma cells, in each layer were quantified under a light microscope (×400). The results revealed that mean serum cortisol was 430.6 ± 68.3 nmol/l. Serum P₄ varied by ovarian status. Serum P₄ of the gilts in the luteal phase was higher than those in the follicular phase (88.3 ± 7.7 versus 20.6 ± 6.2 nmol/l, P < 0.05). As for the endometrium condition, the gilts were classified into acute/subacute endometritis (n = 13), chronic endometritis (n = 9), and normal endometrium (n = 17). Neutrophils were the main local immune cells in the epithelial layer. Lymphocytes were the dominant population in the subepithelial and glandular connective tissue layers. Generally, the serum cortisol tended to negatively correlate with lymphocytes in the subepithelial connective tissue layer (r = −0.28, P = 0.081). In the gilts with acute/subacute endometritis, no correlation among serum cortisol, P₄, and immune cells was observed. In chronic endometritis gilts, only a negative correlation was remarked between P₄ and epithelial lymphocytes (r = −0.83, P = 0.010), epithelial neutrophils (r = −0.79, P = 0.019), and subepithelial neutrophils (r = −0.73, P = 0.025). In the gilts with normal endometrium, P₄ negatively correlated with subepithelial neutrophils (r = −0.55, P = 0.022) while positively correlated with subepithelial macrophages (r = 0.54, P = 0.024) and subepithelial eosinophils (r = 0.60, P = 0.011).     

Release of cardiac troponin I from viable cardiomyocytes is mediated by integrin stimulation

Elevated cardiac troponin-I (cTnI) levels have been demonstrated in serum of patients without acute coronary syndromes, potentially via a stretch-related process. We hypothesize that this cTnI release from viable cardiomyocytes is mediated by stimulation of stretch-responsive integrins. Cultured cardiomyocytes were treated with (1) Gly–Arg–Gly–Asp–Ser (GRGDS, n = 22) to stimulate integrins, (2) Ser–Asp–Gly–Arg–Gly (SDGRG, n = 8) that does not stimulate integrins, or (3) phosphate-buffered saline (control, n = 38). Cells and media were analyzed for intact cTnI, cTnI degradation products, and matrix metalloproteinase (MMP)-2. Cell viability was examined by assay of lactate dehydrogenase (LDH) activity and by nuclear staining with propidium iodide. GRGDS-induced integrin stimulation caused increased release of intact cTnI (9.6 ± 3.0%) as compared to SDGRG-treated cardiomyocytes (4.5 ± 0.8%, p < 0.001) and control (3.0 ± 3.4%, p < 0.001). LDH release from GRGDS-treated cardiomyocytes (15.9 ± 3.8%) equalled that from controls (15.2 ± 2.3%, p = n.s.), indicating that the GRGDS-induced release of cTnI is not due to cell necrosis. This result was confirmed by nuclear staining with propidium iodide. Integrin stimulation increased the intracellular and extracellular MMP2 activity as compared to controls (both p < 0.05). However, despite the ability of active MMP2 to degrade cTnI in vitro, integrin stimulation in cardiomyocytes was not associated with cTnI degradation. The present study demonstrates that intact cTnI can be released from viable cardiomyocytes by stimulation of stretch-responsive integrins.     

Resting serum dehydroepiandrosterone sulfate level increases after 8-week resistance training among young females

This study examined changes among young females of resting serum dehydroepiandrosterone sulfate (DHEAS) concentration after an 8-week period of resistance training. Nineteen healthy untrained young females [training group: age 18.9 (0.3) years, n=10, control group: age 19.3 (1.0) years, n=9; mean (SD)] were recruited in this study. The training group participated in an 8-week resistance training program (2 days per week on nonconsecutive days). The control group did not involve in any resistance training or regular exercise during the study period. Muscular strength, anthropometry, and resting hormonal levels were measured before and after training in both groups. Serum concentrations of DHEAS, dehydroepiandrosterone (DHEA), testosterone and cortisol were measured by radioimmunoassay. Body mass (2.4%) and lean body mass (2.4%) were significantly increased in the training group (P<0.05), but not in the control group. The training also significantly increased one-repetition maximum (1-RM) values (P<0.05). In the training group, resting concentration of serum DHEAS significantly increased after training (P<0.05). Percent change of DHEAS in the training group was greater than that of the control group (P<0.05). In the training group, the change of DHEAS level was positively correlated with the change of lean body mass during the training (r=0.61; P<0.05). Serum DHEA, testosterone and cortisol concentrations did not change in either group during the training. The dramatic increase of resting serum DHEAS concentration after training indicates that DHEAS might be an anabolic hormone marker of adaptation to resistance training among young females. Results are presented as mean (SD).