The silent period in patients with chronic renal failure undergoing hemodialysis

Silent period was evaluated in 20 adult male patients with chronic renal failure undergoing hemodialysis. Readings were obtained by supramaximal stimulus to the median nerve, during maximum isometric effort of the abductor pollicis brevis muscle against resistance. Two types of abnormalities were observed, motor neuron hypoexcitability with elongated silent period, and motor neuron hyperexcitability with reduction or absence of silent period. Some abnormalities are probably linked with dialysis duration, but show no correlation to presence or absence of peripheral neuropathy. The silent period alterations described in this study could possibly correlate with some other clinical feature frequently seen in patients with chronic renal failure such as hypereflexia of the deep tendon reflexes.

Electromyographic validation of the trapezius and serratus anterior muscles in frontal-lateral cross, dumbbells exercises

Based on the lack of electromyographic researches on sport and programmes of physical conditioning, we can say that it is necessary to reexamine some exercises routinely used in the programmes of physical conditioning. Thus, the trapezius and serratus anterior muscles were studied electromyographically so that we could evaluate the validity in some ways of execution of the frontal-lateral cross, dumbbells exercises for the development of these muscles. We analyzed 24 male volunteers, 18 to 25 years old, using a 2-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. For the execution of the exercise it was used a supine bench, a straight board and two bars of 40 cm made of light wood. The results showed that TS acted preferentially in standing modality and in the inclined supine modality, however with activity levels that do not justify its inclusion in physical fitness programmes.

Electromyographic validation of the trapezius and serratus anterior muscles in the rowing and frontal-lateral cross, dumbbells exercises

The trapezius and serratus anterior muscles were studied in four modalities of rowing exercises executed with two grips, middle and closed, in comparison with the four different modalities of frontal-lateral cross, dumbbells exercise. It was used 24 male volunteers, 18 to 25 years old using a 2-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. The results showed that TS acted in a higher significant way in all the modalities of rowing than in the supine lateral raise, inclined supine lateral raise and reverse supine lateral raise, dumbbells exercises, and demonstrated no standing frontal-lateral cross, dumbbells. The SI acted more significantly difference among all the execution modalities of rowing and the inclined supine lateral raise, dumbbells exercises than in all the rowing exercises; even though the activity levels do not make us suggest them as an excellent group of exercises for the development of this muscle.

Mouse extensor digitorum longus and soleus show distinctive ultrastructural changes induced by veratrine

We investigated whether veratrine (5 μl, 10 ng/kg) injected into the mouse extensor digitorum longus (EDL) (fast-twitch) and soleus (SOL) (slow-twitch) muscles provokes distinctive ultrastructural disturbances 15, 30 and 60 min later. The mitochondria in SOL were affected earlier (within 15 min) than in EDL. Swelling of the sarcoplasmic reticulum terminal cisternae was more marked in EDL than in SOL and caused distortion of sarcomeres so that fragmentation of myofilaments was more pronounced in EDL. Hypercontracted sarcomeres were seen mainly in SOL and veratrine caused infoldings of the sarcolemma only in this muscle. In both muscles, the T-tubules remained unaffected and by 60 min after veratrine most of the above alterations had reverted to normal. Pretreatment with tetrodotoxin prevented the alterations induced by veratrine. This suggests that most of the alterations resulted from the enhanced influx of Na+ into muscle fibers. These results emphasize the importance of considering the type of muscle when studying the action of myotoxic agents.

Electromyographic validation of the trapezius and serratus anterior muscles in rowing exercises with middle grip

Because the lack of textbooks based on electromyographic studies in the area of exercises for physical conditioning, the authors proposed to study the trapezius (upper portion) (TS) and the serratus anterior (lower portion) (SI) muscles during the execution of four different modalities of rowing exercises with middle grip in 24 male volunteers, 18 to 25 years old. For the recordings, it was used a two-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. For the movements, a supine bench and a 120 cm-long bar made of low weight wood were used. The results showed that TS acted significantly in upright, sitting and inclined rowing, justifying its inclusion in physical conditioning programmes, while SI, in spite of acting preferentially in upright and sitting rowing, presented activity levels which do not justify its inclusion.

Electromyographic validation of the double pulley equipment during movements of the lower limbs

The double pulley equipment was tested on ten male volunteers during contraction of the semitendinosus and biceps femoris (caput longum) muscles in the following movements of the lower limbs: 1) hip extension with extended knee and erect trunk, 2) hip extension with flexed knee and erect trunk, 3) hip extension with flexed knee and erect trunk, 3) hip extension with extended knee and inclined trunk, 5) hip abduction along the midline, 7) hip abduction with extension beyond the midline, 8) adduction with hip flexion beyond the midline, 8) adduction with hip flexion beyond the midline, and 9) adduction with hip extension beyond the midline. The myoelectric signals were taken up by Lec Tec surface electrodes connected to a 6-channel Lynx electromyographic signal amplifier coupled with a computer equipped with a model CAD 10/26 analogue digital conversion board and with a specific software for signal recording and analysis. The semitendinosus and biceps femoris muscles presented the highest potentials in movements 1; 2; 7, 8 and 9, whereas the potentials in the remaining movements were negligible. The pattern of activity of the semitendinosus and the biceps femoris was similar in exercises 1, 2, 3, 4 and 8. The potentials of the semitendinosus prevailed in movements 5, 6 and 7, and the strongest potentials observed in movement 9 were those of the biceps femoris.

Electromyographic validation of the trapezius and serratus anterior muscles in rowing exercises with closed grip

Because the lack of specialized textbooks, the select of basic exercises for physical conditioning programmes is based on empirical knowledge. This fact led the authors to propose the study on electromyographic activity of the trapezius (upper portion) (TS) and the serratus anterior (lower portion) (SI) muscles in rowing exercises with closed grip in three different modalities. The tests were carried out with 24 male volunteers, 18 to 25 years old, by using a two-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. For exercises execution, a long bar made of light wood was used. TS acted significantly in the three different modalities, that is, upright, sitting and bent over, while SI acted preferentially in upright and sitting rowing exercises, justifying their inclusion as basic exercises in physical conditioning programmes.

Electromyographic validation of the trapezius and serratus anterior muscles in rowing exercises with middle and closed grip

Because the lack of specialized textbooks on the select and indication of basic exercises for physical conditioning programmes, an electromyographic study of the trapezius (upper portion) (TS) and the serratus anterior (lower portion) (SI) muscles in rowing exercises with middle and closed grip in three different modalities, upright, sitting and bent over was performed. The tests were carried out with 24 male volunteers, 18 to 25 years old, by using a two-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. For exercises execution, a supine bench, a straight board and a 1,20 m-long bar made of light wood were used. The results showed that TS acted preferentially with closed grip sitting and bent over modalities, and presented no difference among the grips for upright rowing. SI acted preferentially with closed grip in all modalities, however, with activity levels that do not justify its indication for physical conditioning programmes.

Participation of the deltoid (anterior portion) and pectoralis major (clavicular portion) muscles in different modalities of supine and frontal elevation exercises with different grips

The muscles deltoid-anterior portion (DA) and pectoralis major-clavicular portion (PMC) were analysed to establish the muscular behavior and intensity patterns, as well to evaluate the connected participation of these muscles during supine and frontal elevation exercises. Twenty-four male volunteers were examined using a 2-channel TECA TE4 electromyograph and Hewlett Packard surface electrodes. Our results showed low levels of activity to PMC in frontal elevation exercises, whereas to DA the levels were very high. In the supine exercise, the action potential levels developed by the PMC were always lower than those presented by DA, however, with action simultaneity. Some suggestions to the use of the tested exercises are presented.

Electromyographic analysis of the arm muscles in front support exercises

The electromyographic activity of the biceps brachii - BB (long head), triceps brachii - TB (long head) and deltoideus - DA (clavicular portion) muscles, during the going (G) and return (R) phases in front support exercise, as well the efficacy of this exercise for the development of these muscles strength were studied in 10 male volunteers. The values were normalized through maximum voluntary isometric contraction (MVIC = 100%) and statistically analyzed using the Friedman, DMS and Wilcoxon non-parametric test. A value of p≤0.05 indicated significance (Campos, 1983). All the muscles presented higher electromyographic activity in the return phase of the movement. The triceps brachii was the muscle which had higher activity in both phases of the movement. It was concluded that the front support exercise is efficient for strength development mainly in the triceps brachii muscle.

Tracing metabolic routes of feed ingredients in tissues of broiler chickens using stable isotopes

The present study aimed to quantify the proportion of 13C from energy and protein feed ingredients that follow the metabolic routing of the liver and muscle in broiler chickens. A stable isotope of carbon technique was used that is based on the isotopic discrimination that occurs in the plants during the photosynthesis process. One-day-old male chicks were subjected to treatments based on free choice of energy and protein sources. Rice bran (R) and soybean meal (S), C3 plants, have higher isotopic ratios than corn (C), a C4 plant, and corn gluten meal (G). Choices were R+S, C+G, R+G, C+S, or R+C+G+S. A complete feed (CF) was a sixth treatment. Feed intake and BW were measured at 30 d of age, when liver and breast muscle were collected for isotopic analysis. Treatments affected the amount of feed intake and the choices of energy or protein sources. Complete feed had the largest intake, differing from the other treatments that had free-choice feeding. Final BW was a direct reflection of consumption by these birds in all treatments. The isotopic results indicated that the 13C/12C ratio was generally higher in breast muscle than in liver, probably because of higher protein content. Moreover, in the liver, the proportion of 13C retained from the energy ingredient was greater than the proportion from the protein ingredient. That is in contrast to muscle, where the proportion of 13C retained from the protein ingredient was greater than from the energy ingredient that was self-selected.

Mononeuropathy of the suprascapular nerve: Study of 3 South American cases

In this work 3 new cases of suprascapular nerve mononeuropathy are described. ENMG diagnosis criteria were: a) normal sensory conduction studies of the ipsolateral ulnar, median and radial nerves; b) bilateral suprascapular nerve latencies with bilateral compound muscle action potential, obtained from the infraspinatus muscle with symmetrical techniques; and c) abnormal neurogenic infraspinatus muscle electromyographic findings, coexisting with normal electromyographical data of the ipsolateral deltoideus and supraspinatus muscles. These 3 cases of suprascapular mononeurpathy were found in 6,080 ENMG exams from our University Hospital. For us this mononeuropathy is rare with a 0.05% occurrence.

Stabilization of lumbo-pelvic region and electromyography of the abdominal muscles

It is usual to find athletes that can perform de curl up test easily, but are unable to maintain the stabilization of the low back during the double straight leg lowering (DSLL). In spite of having strong abdominal muscles, its stabilization role seems not to be effective. Thus, the purpose of this study was to verify the relation among individuals with strong abdominal muscles and the ability in perform posterior pelvic tilt (PPT); the ability to stabilize the low back during the DSLL and the eletromyographic activity of the abdominal muscles. Eighteen male subjects (aged 19.27 ± 3.5), without history of muscle skeletal dysfunction, performed both the PPT and DSLL tests. During these tests electromyographic signals of the rectus abdominis (RA), obliquus internus abdominis (01) and obliquus externus abdominis (OE) were recorded, the angle of the hip and the pressure under the low back were measured The results of analyses of variance (ANOVA) show that most volunteers accomplished the PPT test, actively flattening the low back with regular or good quality. However, none of them was able to stabilize the low back during the DSLL test. During the PPT test all abdominal muscle portions analysed were activated without significant differences. In an attempt of maintaining the lumbo-pelvic region stabilized during the DSLL, it was observed a tendency of higher bilateral activation of OE when compared to RA and 01 muscle portions between 70 and 20 degrees of hip flexion.

Manifestações sistêmicas na doença pulmonar obstrutiva crônica

Chronic obstructive pulmonary disease is progressive and is characterized by abnormal inflammation of the lungs in response to inhalation of noxious particles or toxic gases, especially cigarette smoke. Although this infirmity primarily affects the lungs, diverse extrapulmonary manifestations have been described. The likely mechanisms involved in the local and systemic inflammation seen in this disease include an increase in the number of inflammatory cells (resulting in abnormal production of inflammatory cytokines) and an imbalance between the formation of reactive oxygen species and antioxidant capacity (leading to oxidative stress). Weakened physical condition secondary to airflow limitation can also lead to the development of altered muscle function. Chronic obstructive pulmonary disease presents diverse systemic effects including nutritional depletion and musculoskeletal dysfunction (causing a reduction in exercise tolerance), as well as other effects related to the comorbidities generally observed in these patients. These manifestations have been correlated with survival and overall health status in chronic obstructive pulmonary disease patients. In view of these facts, the aim of this review was to discuss findings in the literature related to the systemic manifestations of chronic obstructive pulmonary disease, emphasizing the role played by systemic inflammation and evaluating various therapeutic strategies.

Electromyographic analysis of the pectoralis major and deltoideus anterior in the inclined flying exercise with loads

Due to a shortage of textbooks with specific data on muscular activity concerning physical conditioning and sports, we analysed electromyographically the muscles pectoralis major and deltoideus anterior, bilaterally, in inclined flying exercises, during the concentric and eccentric phases, with external loads of 25, 50, 75 and 100% of the maximum load. The electromyographic analysis was performed in eleven male volunteers with MEDITRACE-200 surface electrodes connected to a six-channel biologic signal acquisition module coupled to a PC/AT computer. The electromyographic signals were processed and the obtained effective values were normalized through maximum voluntary isometric contraction. Statistically, the results showed that all the muscles studied presented significant differences between the concentric and the eccentric phases, with higher electromyographic activity during the concentric phase. By analysing the different loads for each muscle in both phases, significant electromyographic activity was observed for all muscles. When the effect of each load on each muscle during the concentric phase was analysed, it was noticed that the muscles on the left were more active than those on the right side, while in the eccentric phase the muscles had different behavior.