Multi-channel electromyography during maximal isometric and dynamic contractions

Motor unit behavior differs between contraction types at submaximal contraction levels, however is challenging to study during maximal voluntary contractions (MVCs). With multi-channel surface electromyography (sEMG), mean physiological characteristics of the active motor units can be extracted. Two 8-electrode sEMG arrays were attached on biceps brachii muscle (one on each head) to examine behavior of sEMG variables during isometric, eccentric and concentric MVCs of elbow flexors in 36 volunteers.On average, isometric (364 ± 88 N) and eccentric (353 ± 74 N) MVCs were higher than concentric (290 ± 73 N) MVC (p < 0.001). Mean muscle fiber conduction velocity (CV) was highest during eccentric MVC (4.42 ± 0.49 m/s) than concentric (4.25 ± 0.49 m/s, p < 0.01) and isometric (4.14 ± 0.45 m/s, p < 0.001) MVCs. Furthermore, eccentric MVC showed lower sEMG amplitude at the largest elbow joint angles (120–170°) and higher CV at the smallest (70–150°) elbow joint angles (p < 0.05–0.001) than concentric MVC.The differences in CV and sEMG amplitude between the MVCs suggest that the control strategy of motor units differs between the contraction types during MVCs, and is dependent on the muscle length between the dynamic MVCs.     

Uptake of advanced glycation end products by proximal tubule epithelial cells via macropinocytosis

Chronic hyperglycaemia during diabetes leads to non-enzymatic glycation of proteins to form advanced glycation end products (AGEs) that contribute to nephropathy. We describe AGE uptake in LLC-PK1 and HK2 proximal tubule cell lines by macropinocytosis, a non-specific, endocytic mechanism. AGE–BSA induced dorsal circular actin ruffles and amiloride-sensitive dextran–TRITC uptake, significantly increased AGE–BSA–FITC uptake (167 ± 20% vs BSA control, p < 0.01) and was ezrin-dependent. AGE–BSA–FITC uptake was significantly inhibited by amiloride and inhibitors of Arf6, Rac1, racGEF Tiam1, PAK1 and actin polymerisation. AGE–BSA–FITC, Arf6 and PIP2 co-localised within dorsal circular actin ruffles. AGE–BSA increased PAK1 kinase activity (212 ± 41% vs control, p < 0.05) and protein levels of Tiam1, a Rac1 activator. AGE–BSA significantly increased TGF-β₁ protein levels (160 ± 6%, p < 0.001 vs BSA), which were significantly inhibited by inhibitors of Arf6 (82 ± 19%, p < 0.001 vs AGE) and actin polymerisation (107 ± 11%, p < 0.001 vs AGE), suggesting AGEs partially exert their profibrotic effects via macropinocytosis. PAK1 and PIP5Kγ siRNA significantly decreased AGE–BSA–FITC uptake (81 ± 6% and 64 ± 7%, respectively, p < 0.05 vs control for both), and AGE-stimulated TGF-β₁ protein release (99 ± 15% and 49 ± 8% of control, p < 0.05 and p < 0.001, respectively). Inhibition of AGE uptake by macropinocytosis inhibitors and a neutralising TGF-β antibody, reversed the AGE-induced decrease in surface Na⁺K⁺ATPase, suggesting AGE uptake by macropinocytosis may contribute to diabetic kidney fibrosis and/or EMT by modulating this pump. Understanding methods of cellular uptake and signalling by AGEs may lead to novel therapies for diabetic nephropathy.     

Hyperuricemia and metabolic syndrome in children with overweight and obesity

ObjectiveTo study the prevalence of hyperuricemia in children with overweight or obesity and analyze the relation with metabolic syndrome and the diseases that define it.Materials and methodsThis is a cross-sectional prevalence study in 148 children recruited from pediatric endocrinology consultation, with overweight or obesity (12 ± 3 years, 48% boys, BMI 31.8 ± 6.1). We measured BMI, waist-height, waist circumference, blood pressure with standard instrumentation and glucose (fasting and after overload with 75 g), insulin resistance, cholesterol HDL, triglycerides and uric acid.ResultsThe prevalence of hyperuricemia was 53%. Patients with hyperuricemia had greater BMI (33.9 vs 30.6, p = 0.003), plus waist circumference (101.4 vs 91.1 cm, p < 0.001), higher blood pressure: systolic (123.4 vs 111.9 mm Hg, p < 0.001), diastolic (78.2 vs 68.7 mm Hg, p < 0.001). They presented greater blood glucose after overload oral glucose (107.5 vs 100.7 mg/dl, p = 0.03), insulin was higher (29.2 vs 20.7 mg/dl, p = 0.001) as well as HOMA IR (6.5 vs 4.4, p < 0.001) and HDL levels were lower (49.5 vs 54.4 mg/dl, p = 0.02).Uric acid's level which most is the likely diagnosis of metabolic syndrome corresponds to 5.4 mg/dl in our sample (sensitivity: 64% and specificity 62%).ConclusionThe prevalence of hyperuricemia in children with overweight and obesity is high. In the group of patients with obesity and hyperuricemia, we found out that the parameters measured to diagnose with metabolic syndrome were less favorable. Uric acid's level from where there is a higher possibility to see metabolic syndrome is 5.4 mg/dl.     

Hair cortisol determination in sows in two consecutive reproductive cycles

Hair analysis has been proposed as a minimally invasive technique capable of furnishing information regarding the stress response during medium- and long-term periods. Bristle samples were collected from the rump region of sows at three key physiological phases (before delivery – BD; weaning time – WT; pregnancy diagnosis – PD) during consecutive reproductive cycles in order to test swine hair as a reliable matrix of cortisol evaluation. Cortisol was extracted from the bristles and assayed using radioimmunoassay. The highest mean hair cortisol concentrations were demonstrated (p < 0.001) at the PD time points (20.1 ± .95 and 16.29 ± 2.15 pg/mg). Moreover, cortisol was significantly higher (p < 0.001) at BD2 (10.48 ± 0.96 pg/mg) as compared to BD1 (5.17 ± 0.51 pg/mg) and WT1 (6.01 ± 0.47 pg/mg). The various physiological phases had a significant effect on cortisol concentration (p < 0.00001) with a higher cortisol concentration found during late pregnancy and lactation than in early-mid pregnancy. This could be due not only to the physiological hormonal status, but also to the different housing conditions (single crates vs. group housing). The season of the year was also observed to have an effect (p < 0.005), with the lowest cortisol concentration recorded during the hot season.     

Cryopreservation of human failed maturation oocytes shows that vitrification gives superior outcomes to slow cooling

This study investigated whether failed maturation oocytes could be used to evaluate different cryopreservation procedures. A total of 289 failed maturation oocytes (GV and MI stages), obtained from 169 patients undergoing IVF treatment (mean age 33.84 ± 5.0) were divided into two different slow-cooling groups (1.5 mol/l 1,2-propanediol + 0.2 mol/l sucrose in either NaCl (group A) or choline chloride (ChCl) (group B) based cryopreservation solutions) and one vitrification group (15% ethylene glycol + 15% dimethyl sulphoxide). Survival rate, in vitro maturation (IVM) rate, fertilization and developmental rate of cryopreserved oocytes were assessed. Regardless of the stage at which cryopreservation was performed (GV + MI), the slow cooling with ChCl based medium always gave significantly lower survival rate than the slow cooling in NaCl based medium (p = 0.01) and vitrification (p < 0.001). An extended study also showed statistically reduced survival rate between slow-cooling NaCl based medium and vitrification (p < 0.05). Global results of in vitro maturation and fertilization showed worse results between both slow-cooling NaCl and ChCl based media versus vitrification. In conclusion, for oocytes that had failed to mature, vitrification gave better survival, maturation, fertilization and also cleavage rates than the slow-cooling protocols. Four cells embryos were obtained only from vitrified in vitro matured MI oocytes.     

Oestrus in the Julia Creek dunnart (Sminthopsis douglasi) is associated with wheel running behaviour but not necessarily changes in body weight,food consumption or pouch morphology

The Julia Creek dunnart (Sminthopsis douglasi) is an endangered carnivorous marsupial belonging to the family Dasyuridae. This study investigated the oestrous cycle of this species in terms of its reproductive physiology and behaviour to explore more efficient methods of oestrus detection. Ten sexually mature captive female dunnarts were monitored daily at David Fleay Wildlife Park, Burleigh Heads, Australia, from mid September to late December 2006 for changes in urogenital cytology within the urine (0, 1+, 2+ and 3+), running wheel activity, body weight, uneaten food, faecal steroid metabolites (progesterone and oestradiol) and pouch development. Periods of increased running wheel activity were associated (p = 0.004) with an increase in the proportion of cornified urogenital epithelial cells found in the urine; periods of decreasing weight (p < 0.001) and uneaten food (p < 0.001) were also associated with changes in urogenital cytology but not to the point where they would be useful for oestrus detection. Between 60.3% and 92.0% of peak distances (confidence interval 95%) occurred when the epithelial cell index was 2+ or 3+. Only 15.5–37.5% of peak weights (CI: 95%) and 28.1–49.9% of incidences of uneaten food (CI: 95%) occurred when the epithelial cell index was 2+ or 3+. There was no significant difference in the mean length of the oestrous cycle when measured by urogenital cytology (mean ± SD: 25.0 ± 5.7 days; n = 20) or peak distance travelled (mean ± SD: 25.4 ± 5.7 days; n = 20). Changes in the concentration of oestradiol metabolites in Julia Creek Dunnart faeces were not useful in characterising the oestrous cycle. Wheel running activity declined markedly with increased faecal progestagen concentration. The majority of the pouch variables examined showed maximum development during the inter-oestrus period but as there was considerable variation between animals, the pouch was not considered a useful index of oestrus.     

Simultaneous quantification of GABAergic 3α,5α/3α,5β neuroactive steroids in human and rat serum

The 3α,5α- and 3α,5β-reduced derivatives of progesterone, deoxycorticosterone, dehydroepiandrosterone and testosterone enhance GABAergic neurotransmission and produce inhibitory neurobehavioral and anti-inflammatory effects. Despite substantial information on the progesterone derivative (3α,5α)-3-hydroxypregnan-20-one (3α,5α-THP, allopregnanolone), the physiological significance of the other endogenous GABAergic neuroactive steroids has remained elusive. Here, we describe the validation of a method using gas chromatography–mass spectrometry to simultaneously identify serum levels of the eight 3α,5α- and 3α,5β-reduced derivatives of progesterone, deoxycorticosterone, dehydroepiandrosterone and testosterone. The method shows specificity, sensitivity and enhanced throughput compared to other methods already available for neuroactive steroid quantification. Administration of pregnenolone to rats and progesterone to women produced selective effects on the 3α,5α- and 3α,5β-reduced neuroactive steroids, indicating differential regulation of their biosynthetic pathways. Pregnenolone administration increased serum levels of 3α,5α-THP (+1488%, p < 0.001), (3α,5α)-3,21-dihydroxypregnan-20-one (3α,5α-THDOC, +205%, p < 0.01), (3α,5α)-3-hydroxyandrostan-17-one (3α,5α-A, +216%, p < 0.001), (3α,5α,17β)-androstane-3,17-diol (3α,5α-A-diol, +190%, p < 0.01). (3α,5β)-3-hydroxypregnan-20-one (3α,5β-THP) and (3α,5β)-3-hydroxyandrostan-17-one (3α,5β-A) were not altered, while (3α,5β)-3,21-dihydroxypregnan-20-one (3α,5β-THDOC) and (3α,5β,17β)-androstane-3,17-diol (3α,5β-A-diol) were increased from undetectable levels to 271 ± 100 and 2.4 ± 0.9 pg ± SEM, respectively (5/8 rats). Progesterone administration increased serum levels of 3α,5α-THP (+1806%, p < 0.0001), 3α,5β-THP (+575%, p < 0.001), 3α,5α-THDOC (+309%, p < 0.001). 3α,5β-THDOC levels were increased by 307%, although this increase was not significant because this steroid was detected only in 3/16 control subjects. Levels of 3α,5α-A, 3α,5β-A and pregnenolone were not altered. This method can be used to investigate the physiological and pathological role of neuroactive steroids and to develop biomarkers and new therapeutics for neurological and psychiatric disorders.     

Cryopreservation of sperm of an indigenous endangered fish species Nandus nandus (Hamilton, 1822) for ex-situ conservation

This study dealt with the development of cryopreservation protocol for Nandus nandus, which entailed a number of experiments. Sperm was collected by sacrificing males. The collected sperm was suspended in extenders. Activation of sperm motility was evaluated in different osmolalities of NaCl. Motility of sperm decreased as the osmolality of the extender increased and was completely inhibited at almost 319 mOsmol/kg. To evaluate the toxicity of cryoprotectant, sperm was incubated with DMSO, methanol and ethanol at 5%, 10% and 15% concentrations, respectively, for 5–35 min. Five and ten percent of cryoprotectants produced better motility during 5 and 10 min incubation. Sperm incubated with 15% cryoprotectant seemed to be toxic and this concentration was excluded in the subsequent trials. Three extenders, namely, Alsever’s solution, egg-yolk citrate and urea egg-yolk and three cryoprotectants, DMSO, methanol and ethanol were employed to preserve the sperm. Alsever’s solution with 10% DMSO showed best performance producing 90.0 ± 1.8% and 75.0 ± 2.5% equilibration and post-thaw motility followed by that of 82.5 ± 4.2% and 62.5 ± 5.5% with Alsever’s solution plus methanol, respectively. Between two diluents, sperm preserved with Alsever’s solution plus DMSO produced highest fertilization (76.7 ± 3.3%) and hatching (43.8 ± 7.9%) while fresh sperm yielded 83.3 ± 6.7% and 64.0 ± 10.4% fertilization and hatching, respectively. The protocol developed through the study can be applied for long-term conservation of genetic materials of the endangered fish N. nandus and the cryopreserved sperm can be used in artificial breeding for generating new individuals.     

Haematological and biochemical parameters and tissue accumulations of cadmium in Oreochromis niloticus exposed to various concentrations of cadmium chloride

Oreochromis niloticus, weighing 36.45 ± 1.12 g were exposed to 10%, 20% and 30% of the LC₅₀ of CdCl₂ which represents treatments (T1)1.68, (T2)3.36 and (T3)5.03 mg/l, respectively, for a period of 10, 20 and 30 days. It was found that, compared to a control group reading of 0.19 ± 0.03 μg/g dry weight, accumulation of Cd in the gills was significantly (p < 0.05) increased in samples ranging between 7.64 ± 0.86 and 61.73 ± 0.82 μg/g dry weight from T1 at 10 days to T3 at 30 days. The accumulation of Cd in the liver, meanwhile, was also observed to significantly increase (p < 0.05) with increasing time and concentrations with results ranging between 3.21 ± 0.12 and 181.61 ± 1.32 compared to the control group results of 0.29 ± 0.04 μg/g dry weight. Although muscles exhibited lower levels of accumulation than the gills and liver they still showed the same pattern of increase compared to the control group, with a significant difference ranging between 0.32 ± 0.02 and 2.16 ± 0.08 compared to the control group results of 0.03 ± 0.001 μg/g dry weight. Also, haematological parameters such as red blood cells (RBCs), haemoglobin (Hb) and haematocrit (Hct) were reduced in fish exposed to Cd at all periods, with significant differences (p < 0.05). Plasma glucose concentration showed a significant increase. Total protein levels of fish showed a significant reduction (p > 0.05) for all exposed treatments. Also, the total lipid level increased significantly as fish were exposed to increasing cadmium concentrations, compared to control fish. Finally, the activities of aspartate aminotransferase (AST IU/l) and alanine aminotransferase (ALT IU/l) showed a significant increase (p < 0.05) with increasing time and concentrations.     

Cryopreservation of human failed maturation oocytes shows that vitrification gives superior outcomes to slow cooling

This study investigated whether failed maturation oocytes could be used to evaluate different cryopreservation procedures. A total of 289 failed maturation oocytes (GV and MI stages), obtained from 169 patients undergoing IVF treatment (mean age 33.84 ± 5.0) were divided into two different slow-cooling groups (1.5 mol/l 1,2-propanediol + 0.2 mol/l sucrose in either NaCl (group A) or choline chloride (ChCl) (group B) based cryopreservation solutions) and one vitrification group (15% ethylene glycol + 15% dimethyl sulphoxide). Survival rate, in vitro maturation (IVM) rate, fertilization and developmental rate of cryopreserved oocytes were assessed. Regardless of the stage at which cryopreservation was performed (GV + MI), the slow cooling with ChCl based medium always gave significantly lower survival rate than the slow cooling in NaCl based medium (p = 0.01) and vitrification (p < 0.001). An extended study also showed statistically reduced survival rate between slow-cooling NaCl based medium and vitrification (p < 0.05). Global results of in vitro maturation and fertilization showed worse results between both slow-cooling NaCl and ChCl based media versus vitrification. In conclusion, for oocytes that had failed to mature, vitrification gave better survival, maturation, fertilization and also cleavage rates than the slow-cooling protocols. Four cells embryos were obtained only from vitrified in vitro matured MI oocytes.     

Effect of simultaneous variation in temperature and ammonia concentration on percent fertilization and hatching in Crassostrea ariakensis

The combined effects of temperature and ammonia concentration on the percent fertilization and percent hatching in Crassostrea ariakensis were examined under laboratory conditions using the central composite design and response surface methodology. The results indicated: (1) The linear effects of temperature and ammonia concentration on the percent fertilization were significant (P<0.05), and the quadratic effects were highly significant (P<0.01). The interactive effect between temperature and ammonia concentration on the percent fertilization was not significant (P>0.05). (2) The linear effect of temperature on the percent hatching was highly significant (P<0.01), and that of ammonia concentration was nonsignificant (P>0.05). The quadratic effects of temperature and ammonia concentration on the percent hatching were highly significant (P<0.01). The interaction on the percent hatching was not significant (P>0.05). Temperature was more important than ammonia in influencing the fertilization and hatching in C. ariakensis. (3) The model equations of the percent fertilization and hatching towards temperature and ammonia concentration were established, with the coefficients of determination R²=99.4% and 99.76%, respectively. Through the lack-of-fit test, these models were of great adequacy. The predictive coefficients of determination for the two model equations were as high as 94.6% and 98.03%, respectively, showing that they could be used for practical projection. (4) Via the statistical simultaneous optimization technique, the optimal factor level combination, i.e., 25 °C/0.038 mg mL⁻¹, was derived, at which the greatest percent fertilization 95.25% and hatching 83.26% was achieved, with the desirability being 97.81%. Our results may provide advantageous guidelines for the successful reproduction of C. ariakensis.     

Metabolic control and chronic complications during a 3-year follow-up period in a cohort of type 2 diabetic patients attended in primary care in the Community of Madrid (Spain)

BackgroundOur aim was to analyze both metabolic control and chronic complications of type 2 diabetes mellitus (T2D) patients regularly attended in primary care during a 3 years of follow-up in the Community of Madrid (Spain).MethodsFrom 2007 to 2010 we prospectively included 3268 patients with T2D attended by 153 primary care physicians from 51 family health centers. An prospective cohort study with annual evaluation over 3 years to the same population was performed. We measured the goals of control in diabetic patients and the incidence of chronic complications of diabetes during the study period.ResultsA significant decrease in serum glucose levels (143 ± 42 mg/dl vs 137 ± 43 mg/dl, p < 0.00), HbA1c (7.09 ± 1.2% vs 7.02 ± 1.2%, p < 0.00), total cholesterol (191.4 ± 38 mg/dl vs 181.5 ± 36 mg/dl, p < 0.00), LDL cholesterol (114.7 ± 31 mg/dl vs 105.5 ± 30 mg/dl, p < 0.00) and triglyceride levels (144.5 ± 93 mg/dl vs 138 ± 84 mg/dl, p < 0.00) during study period was documented. On the contrary, a significant elevation in HDL cholesterol levels was observed (49.2 ± 14 mg/dl vs 49.9 ± 16 mg/dl, p < 0.00). The incidence of diabetic complications throughout the study period was low, with a incidence of coronary heart disease of 6.2%, peripheral arterial disease 3%, ischemic stroke 2.8%, diabetic foot 11.2%, nephropathy 5.9%, retinopathy 4.5%, and neuropathy 3%.ConclusionMetabolic control in T2D patients attended in primary care in the Community of Madrid throughout 3 years is adequate and is accompanied by low percent of chronic diabetic complications during this period of follow-up.     

Impaired effect of relaxin on vasoconstrictor reactivity in spontaneous hypertensive rats

Relaxin is thought to be involved in vasodilation to pregnancy by increasing endothelium-dependent vasodilation and compliance, and decreasing myogenic reactivity. Primary (essential) hypertension predisposes to circulatory maladaptation and subsequent gestational hypertensive disease. This study aimed to determine that vascular responses to chronic exposure to relaxin are impaired in young female rats with primary hypertension. In 10–12 weeks old Wistar-Hannover rats (WHR) and spontaneous hypertensive rats (SHR), we determined vascular responses in isolated kidney and mesenteric arteries after 5-days of chronic exposure to relaxin (4 μg/h) or placebo. SHR show decreased sensitivity to phenylephrine (by 67%, p < 0.01) and renal perfusion flow (RPFF, by 19%, p < 0.01), but no changes in flow-mediated vasodilation, myogenic reactivity or vascular compliance. In WHR, relaxin stimulated flow-mediated vasodilation (2.67 fold, from 48 ± 9 to 18 ± 4 μl/min, p = 0.001), inhibited myogenic reactivity (from −1 ± 2 to 7 ± 3 μm/10 mm Hg, p = 0.01), and decreased sensitivity to phenylephrine (28%, from 1.39 ± 0.08 to 1.78 ± 0.10 μM, p < 0.01), but left compliance and RPFF unchanged. NO-blockade by l-NAME diminished most relaxin-mediated responses. In SHR, the vasodilator effects of relaxin were blunted for myogenic reactivity and sensitivity to phenylephrine, with similar effects on flow-mediated vasodilation, compliance, RPFF and equal Rxfp1 (relaxin family peptide receptor) gene expression, as compared to WHR. Primary hypertension blunts both the relaxin-induced inhibition of myogenic reactivity and α-adrenergic vasoconstrictor response, independent from Rxfp1 gene expression, while the relaxin-dependent enhanced flow-mediated vasodilation remains intact. This implies selective resistance to relaxin in young subjects suffering from primary hypertension.     

Unchanged H-reflex during a sustained isometric submaximal plantar flexion performed with an EMG biofeedback

The aim of this study was to assess H-reflex plasticity and activation pattern of the plantar flexors during a sustained contraction where voluntary EMG activity was controlled via an EMG biofeedback. Twelve healthy males (28.0 ± 4.8 yr) performed a sustained isometric plantar flexion while instructed to maintain summed EMG root mean square (RMS) of gastrocnemius lateralis (GL) and gastrocnemius medialis (GM) muscles fixed at a target corresponding to 80% maximal voluntary contraction torque via an EMG biofeedback. Transcutaneous electrical stimulation of the posterior tibial nerve was evoked during the contraction to obtain the maximal H-reflex amplitude to maximal M-wave amplitude ratio (H_sup/M_sup ratio) from GL, GM and soleus (SOL) muscles. Neuromuscular function was also assessed before and immediately after exercise. Results showed a decrease in SOL activation during sustained flexion (from 65.5 ± 6.4% to 42.3 ± 3.8% maximal EMG, p < 0.001), whereas summed EMG RMS of GL and GM remained constant (59.7 ± 4.8% of maximal EMG on average). No significant change in the H_sup/M_sup ratio was found for SOL, GL and GM muscles. Furthermore, it appears that the decrease in maximal voluntary contraction torque (?20.4 ± 2.9%, p < 0.001) was related to both neural and contractile impairment. Overall, these findings indicate that the balance between excitation and inhibition affecting the motoneuron pool remains constant during a sustained contraction where myoelectrical activity is controlled via an EMG biofeedback or let free to vary.     

Rotator cuff tendinopathy alters the muscle activity onset and kinematics of scapula

Athletes with rotator cuff (RC) tendinopathy demonstrate an aberrant pattern of scapular motion which might relate to deficits in the scapular muscles. This study aimed to determine whether alteration in scapular kinematics is associated with deficits in the activity onset of scapular muscles. Forty-three male volleyball players (17 asymptomatic and 26 with RC tendinopathy) joined the study. Three-dimensional scapular kinematics was quantified using an acromial marker cluster method. The activity onset of the upper (UT), middle (MT), and lower trapezius (LT), and serratus anterior (SA) during arm abduction was assessed with electromyography. Athletes with RC tendinopathy demonstrated less scapular upward rotation (6.6 ± 2.3 vs. 8.2 ± 1.1°, p = 0.021) in the early phase of shoulder abduction from 0° to 30° when compared to asymptomatic athletes. The tendinopathy group had delayed activity onset of LT (14.1 ± 31.4 ms vs. 74.4 ± 45.1 ms, p < 0.001) and SA (−44.9 ± 26.0 ms vs. 23.0 ± 25.2 ms, p < 0.001) relative to UT when compared to the asymptomatic group. In asymptomatic athletes, earlier activity onset of MT and LT relative to UT was associated with more scapular upward rotation during 0–30° of abduction (r = 0.665, p = 0.021) and 30–60° of abduction (r = 0.680, p = 0.015), respectively. Our findings showed the control of the scapular upward rotation is related to the activity onset of the scapular muscles in athletes.     

Mechanical properties of the patellar tendon in adults and children

It is not currently known how the mechanical properties of human tendons change with maturation in the two sexes. To address this, the stiffness and Young's modulus of the patellar tendon were measured in men, women, boys and girls (each group, n=10). Patellar tendon force (F_pt) was calculated from the measured joint moment during a ramped voluntary isometric knee extension contraction, the antagonist knee extensor muscle co-activation quantified from its electromyographical activity, and the patellar tendon moment arm measured from magnetic resonance images. Tendon elongation was imaged using the sagittal-plane ultrasound scans throughout the contraction. Tendon cross-sectional area was measured at rest from ultrasound scans in the transverse plane. Maximal F_pt and tendon elongation were (mean±SE) 5453±307 N and 5±0.5 mm for men, 3877±307 N and 4.9±0.6 mm for women, 2017±170 N and 6.2±0.5 mm for boys and 2169±182 N and 5.9±0.7 mm for girls. In all groups, tendon stiffness and Young's modulus were examined at the level that corresponded to the maximal 30% of the weakest participant's F_pt and stress, respectively; these were 925–1321 N and 11.5–16.5 MPa, respectively. Stiffness was 94% greater in men than boys and 84% greater in women than girls (p<0.01), with no differences between men and women, or boys and girls (men 1076±87 N/mm; women 1030±139 N/mm; boys 555±71 N/mm and girls 561.5±57.4 N/mm). Young's modulus was 99% greater in men than boys (p<0.01), and 66% greater in women than girls (p<0.05). There were no differences in modulus between men and women, or boys and girls (men 597±49 MPa; women 549±70 MPa; boys 255±42 MPa and girls 302±33 MPa). These findings indicate that the mechanical stiffness of tendon increases with maturation due to an increased Young's modulus and, in females due to a greater increase in tendon cross-sectional area than tendon length.     

Angiotensin II-induced activation of c-Ret signaling is critical in ureteric bud branching morphogenesis

The renin-angiotensin system (RAS) plays a critical role in ureteric bud (UB) and kidney morphogenesis. Mutations in the genes encoding components of the RAS cause a spectrum of congenital abnormalities of the kidney and urinary tract (CAKUT). However, the mechanisms by which aberrations in the RAS result in CAKUT are poorly understood. Given that c-Ret receptor tyrosine kinase (RTK) is a major inducer of UB branching, the present study tested the hypothesis that angiotensin (Ang) II-induced activation of c-Ret plays a critical role in UB branching morphogenesis. E12.5 mice metanephroi were grown for 24 h in the presence or absence of Ang II, Ang II AT₁ receptor (AT₁R) antagonist candesartan, phosphatidylinositol 3-kinase (PI3 K) inhibitor LY294002 or ERK1/2 inhibitor PD98059. Ang II increased the number of UB tips (61 ± 2.4 vs. 45 ± 4.3, p < 0.05) compared with control. Quantitative RT-PCR analysis demonstrated that Ang II increased c-Ret mRNA levels in the kidney (1.35 ± 0.05 vs. 1.0 ± 0, p < 0.01) and in the UB cells (1.28 ± 0.04 vs. 1.0 ± 0, p < 0.01) compared to control. This was accompanied by increased Tyr¹⁰⁶²Ret phosphorylation by Ang II (5.5 ± 0.9 vs. 1.8 ± 0.4 relative units, p < 0.05). In addition, treatment of UB cells with Ang II (10^?5 M) increased phosphorylation of Akt compared to control (213 ± 16 vs. 100 ± 20%, p < 0.05). In contrast, treatment of metanephroi or UB cells with candesartan decreased c-Ret mRNA levels (0.72 ± 0.06 vs. 1.0 ± 0, p < 0.01; 0.68 ± 0.07 vs. 1.0 ± 0, p < 0.05, respectively) compared with control. Ang II-induced UB branching was abrogated by LY294002 (24 ± 2.6 vs. 37 ± 3.0, p < 0.05) or PD98059 (33 ± 2.0 vs. 48 ± 2.2, p < 0.01). These data demonstrate that Ang II-induced UB branching depends on activation of Akt and ERK1/2. We conclude that cross-talk between the RAS and c-Ret signaling plays an important role in the development of the renal collecting system.     

Effect of grazing and homeopathy on milk production and immunity of Merino derived ewes

The effect of grazing and homeopathic therapy on sheep immune response and milk production was investigated on 40 multiparous Merino derived ewes. Twenty animals were housed in an indoor-bedded pen (P), whereas 20 others were allowed to graze on pasture for 9 h/d (G). P and G animals were fed an equivalent diet in terms of dry matter intake, crude protein percentage and energy concentration. In each group, 10 animals were subjected to unicistic homeopathic treatments (H), while 10 ewes were kept as a control and treated with conventional medicine when necessary (C). The grazing rearing system had a marked positive effect on in vivo cellular immune response (delayed-type hypersensivity to PHA, P < 0.001). Grazing animals produced more milk than the penned ones (1048.00 ± 75.61 kg versus 853.04 ± 67.78 kg, P < 0.05), with increased content of milk fat (7.69 ± 0.15% versus 7.25 ± 0.14%, P < 0.05). Accordingly, blood levels of triglycerides (P < 0.01), urea (P < 0.001) and alanine aminotransferase (ALT) (P < 0.001) were significantly higher in group G. The homeopathic treatments produced limited effects on the milk production and immune response. However, such treatments reduced the risk of contamination of the products with medicinal traces, as H group received no allopathic treatment.     

Switching to basal-bolus insulin therapy is effective and safe in long-term type 2 diabetes patients inadequately controlled with other insulin regimens

AimTo assess in standard clinical practice the feasibility, efficacy, and safety of switching patients with long-standing type 2 diabetes (T2DM) and poor or unstable blood glucose control to basal-bolus insulin therapy.Material and methodsThis was a prospective, single center study including 37 patients with T2DM (age 65 ± 8 years, 62.2% men, body mass index 28.8 ± 6.2 kg/m², diabetes duration 18 ± 8 years) with poor or unstable glycemic control, who were switched to a basal-bolus insulin regimen with glargine and rapid-acting insulin analogue at the discretion of their physicians. After a group-structured outpatient diabetes training program, patients were followed in a clinical practice setting for 6 months. Clinical and biochemical variables were collected before switching and at 3 and 6 months.ResultsAfter switching to basal-bolus therapy, glycosylated hemoglobin (HbA1c) decreased from 9 ± 1.2% to 8.1 ± 1.2% (p < 0.001) at 3 months and to 8.0 ± 1.2% at 6 months (p < 0.001) without changing total daily insulin dose. The proportion of patients with HbA1c ≥ 9% decreased from 51% to 13.8% at 3 months and to 18.9% at 6 months respectively. There was a single episode of severe hypoglycemia. No changes were seen in body weight and quality of life. The size of LDL (low density lipoprotein) particles significantly increased at 3 and 6 months, while all other lipid parameters remained unchanged.ConclusionsOur study confirmed that basal-bolus insulin therapy is feasible, effective, and safe in patients with long-standing T2DM, and does not impair their quality of life.