Serum adipocytokine profile and metabolic syndrome in young adult female dermatomyositis patients

OBJECTIVES: To analyse the frequency of metabolic syndrome in young adult female dermatomyositis patients and its possible association with clinical and laboratory dermatomyositis-related features and serum adipocytokines. METHOD: This cross-sectional study included 35 dermatomyositis patients and 48 healthy controls. Metabolic syndrome was defined according to the 2009 Joint Interim Statement. RESULTS: Patient age was comparable in the dermatomyositis and control groups, and the median disease duration was 1.0 year. An increased prevalence of metabolic syndrome was detected in the dermatomyositis group (34.3% vs. 6.3%; p=0.001). In addition, increased serum adiponectin and resistin levels were noted in contrast to lower leptin levels. In dermatomyositis patients, adipocytokine levels were correlated with the levels of total cholesterol, low-density cholesterol, triglycerides and muscle enzymes. A comparison of dermatomyositis patients with (n=12) and without (n=23) syndrome metabolic revealed that adipocytokine levels were also correlated with age, and that dermatomyositis patients with metabolic syndrome tended to have more disease activity despite similar adipocytokine levels. CONCLUSIONS: Metabolic syndrome is highly prevalent in young adult female dermatomyositis patients and is related to age and disease activity. Moreover, increased serum adiponectin and resistin levels were detected in dermatomyositis patients, but lower serum leptin levels were observed.

A study on the structure and morphologic development of calcaneal tendon and triceps surae muscle in human fetuses during the fetal period and the evaluation of clinical importance of calcaneal tendon / Estudio sobre la estructura y desarrollo morfológico del tendón calcáneo y el músculo tríceps sural en fetos humanos durante el período fetal y evaluación de la importancia clínica del tendón calcáneo

It was aimed that the morphometric development of calcaneal tendon and the structures building it up in human fetuses during the fetal period be anatomically studied and that its clinical importance be evaluated. The study comprised a total of 102 fetus legs (51 human fetuses: 26 male and 25 female) whose ages varied between 15-40 gestational week, without external pathology or anomaly. The fetuses were divided in groups according to gestational weeks, trimesters and months. In the wake of the general external measurements of fetuses, leg dissection was performed. Afterwards, the morphometric parameters of gastrocnemius muscle, soleus muscle and calcaneal tendon were measured. The averages and the standard deviations of the measured parameters were determined according to gestational weeks, trimesters and months. There was a significant correlation between the measured parameters and the gestational age (p<0.001). There was no difference between sexes in terms of parameters (p>0.005). All the obtained results were discussed by making a comparison between them and the previous studies made. We are of the opinion that the data obtained in our study will be of use to the involved clinicians in the evaluation of the development of calcaneal tendon and the structures constituting it during the fetal period and in clinical studies and applications as well.

El objetivo de esta investigación consiste en el estudio del desarrollo morfométrico del tendón calcáneo y las estructuras que se desarrollan con él durante el período fetal humano y evaluar su importancia clínica. El estudio comprendió un total de 102 piernas de fetos (51 fetos humanos: 26 masculinos y 25 femeninos) cuyas edades variaron entre 15 a 40 semanas de edad gestacional, sin presencia de patología externa o anomalía. Los fetos fueron divididos en grupos de acuerdo con las semanas de gestación, trimestres y meses. Luego de realizar mediciones generales externas en los fetos, se procedió a la disección de las piernas. Se midieron parámetros morfométricos correspondientes a los músculos gastrocnemio, sóleo y tendón calcáneo. Los promedios y las desviaciones estándar de los parámetros medidos se determinaron de acuerdo a la edad gestacional de los fetos, en semanas trimestres y meses. Hubo una correlación significativa entre los parámetros medidos y la edad gestacional (p<0,001). No hubo diferencias entre los sexos en términos de parámetros (p>0,005). Todos los resultados obtenidos se discutieron haciendo una comparación entre ellos y los estudios previos realizados. Los datos obtenidos en nuestro estudio serán de utilidad para los médicos en la evaluación del desarrollo del tendón calcáneo y las estructuras que lo constituyen, durante el período fetal, para la utilización de este conocimiento en estudios clínicos y diversas aplicaciones.

Resistance training improves body composition and increases matrix metalloproteinase 2 activity in biceps and gastrocnemius muscles of diet-induced obese rats

OBJECTIVE: We investigated the influence of resistance training on body composition and matrix metalloproteinase 2 activity in skeletal muscles of rats fed a high-fat diet. METHODS: Thirty-two Wistar rats were divided into four experimental groups (n = 8/each) according to diet and exercise status: Control (standard diet), Obese Control (high-fat diet), Resistance Training (standard diet) and Obese Resistance Training (high-fat diet) groups. Animals were fed a high-fat diet for 12 weeks to promote excessive weight gain. Resistance Training groups performed 12 weeks of training periods after this period in a vertical ladder three times/week. Fat percentage, fat-free mass and fat mass were assessed using dual-energy X-ray absorptiometry, and matrix metalloproteinase 2 activity in biceps and gastrocnemius muscles was analyzed using zymography. RESULTS: Resistance training significantly reduced body and fat masses and fat percentages in both trained groups (p<0.05). The maximal carrying load between trained groups was not different, but relative force was higher in the Resistance Training group (p<0.05). Of note, increased matrix metalloproteinase 2 activity was noted in the tested muscles of both trained groups (p<0.05). CONCLUSION: In conclusion, altered body composition and muscle matrix metalloproteinase 2 activity promoted by excessive weight gain were positively modified by resistance training. .

Impact of metformin treatment and swimming exercise on visfatin levels in high-fat-induced obesity rats / Impacto do tratamento com metformina e da natação nos níveis de visfatina em ratos com obesidade induzida por dieta com alto teor de gordura

Objective : Visfatin is a recently discovered adipocytokine that contributes to glucose and obesity-related conditions. Until now, its responses to the insulin-sensitizing agent metformin and to exercise are largely unknown. We aim to investigate the impact of metformin treatment and/or swimming exercise on serum visfatin and visfatin levels in subcutaneous adipose tissue (SAT), peri-renal adipose tissue (PAT) and skeletal muscle (SM) of high-fat-induced obesity rats. Materials and methods : Sprague-Dawley rats were fed a normal diet or a high-fat diet for 16 weeks to develop obesity model. The high-fat-induced obesity model rats were then randomized to metformin (MET), swimming exercise (SWI), or adjunctive therapy of metformin and swimming exercise (MAS), besides high-fat obesity control group and a normal control group, all with 10 rats per group. Zoometric and glycemic parameters, lipid profile, and serum visfatin levels were assessed at baseline and after 6 weeks of therapy. Visfatin levels in SAT, PAT and SM were determined by Western Blot. Results : Metformin and swimming exercise improved lipid profile, and increased insulin sensitivity and body weight reduction were observed. Both metformin and swimming exercise down-regulated visfatin levels in SAT and PAT, while the adjunctive therapy conferred greater benefits, but no changes of visfatin levels were observed in SM. Conclusion : Our results indicate that visfatin down-regulation in SAT and PAT may be one of the mechanisms by which metformin and swimming exercise inhibit obesity. .

Objetivo : A visfatina é uma adipocina recentemente descoberta que contribui com as condições relacionadas à glicose e à obesidade. Até hoje, pouco se sabe da sua resposta à metformina, um agente sensibilizador de insulina, e ao exercício. Nosso objetivo foi investigar o impacto do tratamento com metformina e/ou da natação sobre a visfatina no soro e no tecido adiposo subcutâneo (TAS), tecido adiposo perirrenal (TAP) e músculo esquelético (ME) em ratos com obesidade induzida por dieta com alto teor de gordura. Materiais e métodos : Ratos Sprague-Dawley foram alimentados com uma dieta normal ou com alto teor de gordura por 16 semanas para o desenvolvimento de um modelo de obesidade. Os ratos do modelo de obesidade foram, então, randomizados para a metformina, natação ou terapia de combinação com metformina e natação, além do grupo controle de obesidade induzida por alto teor de gordura e do grupo controle normal. Cada grupo apresentava 10 ratos. Parâmetros zoométricos e glicêmicos, perfil lipídico e níveis de visfatina sérica foram avaliados no momento inicial e após seis semanas de tratamento. Os níveis de visfatina em TAS, TAP e ME foram determinados por Western Blot. Resultados : A metformina e a natação melhoraram o perfil lipídico e aumentaram a sensibilidade à insulina, com redução do peso corporal. Tanto a metformina quanto a natação levaram à regulação para baixo dos níveis de visfatina no TAS e TAP, enquanto a terapia de combinação apresentou os maiores benefícios, mas não foram observadas alterações nos níveis de visfatina no ME. Conclusão : Nossos resultados indicam que a regulação para baixo da visfatina no TAS e TAP pode ser um dos mecanismos pelos quais a metformina ...

Muscle biopsy in Pompe disease / Biópsia muscular na doença de Pompe

Pompe disease (PD) can be diagnosed by measuring alpha-glucosidase levels or by identifying mutations in the gene enzyme. Muscle biopsies can aid diagnosis in doubtful cases. Methods: A review of muscle biopsy from 19 cases of PD (infantile, 6 cases; childhood, 4 cases; and juvenile/adult, 9 cases). Results: Vacuoles with or without glycogen storage were found in 18 cases. All cases had increased acid phosphatase activity. The vacuole frequency varied (almost all fibers in the infantile form to only a few in the juvenile/adult form). Atrophy of type 1 and 2 fibers was frequent in all forms. Atrophic angular fibers in the NADH-tetrazolium reductase and nonspecific esterase activity were observed in 4/9 of the juvenile/adult cases. Conclusion: Increased acid phosphatase activity and vacuoles were the primary findings. Most vacuoles were filled with glycogen, and the adult form of the disease had fewer fibers with vacuoles than the infantile or childhood forms. .

O diagnóstico da doença de Pompe (PD) pode ser feito pela dosagem da enzima alfa-glicosidase ou pela mutação do seu gene codificador. A biópsia muscular pode ajudar em casos duvidosos. Métodos: Revisão das biópsias musculares de 19 casos de PD (forma infantil, 6 casos; infantil tardia, 4; e juvenil/adulto, 9). Resultados: Encontrados vacúolos em 18 casos, com ou sem depósito de glicogênio. Todos mostraram aumento da fosfatase ácida. Os vacúolos estavam presentes na maioria das fibras nas formas infantis, menos frequentes nas formas juvenil e mais raros nas formas do adulto. A atrofia de fibras dos tipos 1 e 2 ocorreram em todas as formas. Fibras atróficas na NADH-tetrazolium redutase e esterase não específica foram observadas em 4/9 das formas infantil tardia/adulta. Conclusões: Os dados mais frequentes foram vacúolos, preenchidos por glicogênio com atividade aumentada da fosfatase ácida. A forma adulta apresenta menor número de vacúolos que as formas infantil e infantil tardia. .

The acute effects of strength, endurance and concurrent exercises on the Akt/mTOR/p70S6K1 and AMPK signaling pathway responses in rat skeletal muscle

The activation of competing intracellular pathways has been proposed to explain the reduced training adaptations after concurrent strength and endurance exercises (CE). The present study investigated the acute effects of CE, strength exercises (SE), and endurance exercises (EE) on phosphorylated/total ratios of selected AMPK and Akt/mTOR/p70S6K1 pathway proteins in rats. Six animals per exercise group were killed immediately (0 h) and 2 h after each exercise mode. In addition, 6 animals in a non-exercised condition (NE) were killed on the same day and under the same conditions. The levels of AMPK, phospho-Thr172AMPK (p-AMPK), Akt, phospho-Ser473Akt (p-Akt), p70S6K1, phospho-Thr389-p70S6K1 (p-p70S6K1), mTOR, phospho-Ser2448mTOR (p-mTOR), and phospho-Thr1462-TSC2 (p-TSC2) expression were evaluated by immunoblotting in total plantaris muscle extracts. The only significant difference detected was an increase (i.e., 87%) in Akt phosphorylated/total ratio in the CE group 2 h after exercise compared to the NE group (P = 0.002). There were no changes in AMPK, TSC2, mTOR, or p70S6K1 ratios when the exercise modes were compared to the NE condition (P ≥ 0.05). In conclusion, our data suggest that low-intensity and low-volume CE might not blunt the training-induced adaptations, since it did not activate competing intracellular pathways in an acute bout of strength and endurance exercises in rat skeletal muscle.

Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats

We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min-1·mg protein-1) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a "time-efficient" strategy inducing metabolic adaptation.

Pulsed ultrasound therapy accelerates the recovery of skeletal muscle damage induced by Bothrops jararacussu venom

We studied the effect of pulsed ultrasound therapy (UST) and antibothropic polyvalent antivenom (PAV) on the regeneration of mouse extensor digitorum longus muscle following damage by Bothrops jararacussu venom. Animals (Swiss male and female mice weighing 25.0 ± 5.0 g; 5 animals per group) received a perimuscular injection of venom (1 mg/kg) and treatment with UST was started 1 h later (1 min/day, 3 MHz, 0.3 W/cm², pulsed mode). Three and 28 days after injection, muscles were dissected and processed for light microscopy. The venom caused complete degeneration of muscle fibers. UST alone and combined with PAV (1.0 mL/kg) partially protected these fibers, whereas muscles receiving no treatment showed disorganized fascicules and fibers with reduced diameter. Treatment with UST and PAV decreased the effects of the venom on creatine kinase content and motor activity (approximately 75 and 48%, respectively). Sonication of the venom solution immediately before application decreased the in vivo and ex vivo myotoxic activities (approximately 60 and 50%, respectively). The present data show that UST counteracts some effects of B. jararacussu venom, causing structural and functional improvement of the regenerated muscle after venom injury.

Muscle biopsy features in critical ill patients with 2009 influenza A (H1N1) virus infection / Alterações da biópsia muscular em pacientes gravemente acometidos pela infecção por vírus influenza A (H1N1) 2009

Higher serum creatine kinase (CK) levels in critically ill patients with a confirmed 2009 influenza A (H1N1) infection suggests a possible relationship between the H1N1 virus and muscle tissue. However, there have been no reports with an emphasis on muscle biopsies for patients infected with the H1N1 virus. The objective of this study was to investigate the histological characteristics of the muscle biopsies from critically ill patients with confirmed 2009 H1N1 infections. A series of ten patients with confirmed 2009 H1N1 infection, who presented increased serum CK levels, was analyzed. Histological study found small histochemical alterations in muscles fibers (mainly in NADH, SDH, COX, myophosphorylase, adenylate deaminase and PAS stains), and no histological changes were compatible with inflammatory myopathy. Although our critically ill patients had elevated CK levels, they exhibited few histological/histochemical abnormalities in their muscle biopsy samples; however, those alterations could be consistent with metabolic dysfunction associated with influenza H1N1 infection.

Os elevados níveis séricos da creatina quinase (CK) em pacientes gravemente acometidos pela infecção por influenza A (H1N1) 2009 sugerem uma possível relação entre infecção pelo vírus H1N1 e alterações do tecido muscular. No entanto, não existem relatos com ênfase nas alterações histológicas encontradas no músculo dos pacientes infectados pelo vírus H1N1. O objetivo deste estudo foi investigar as características histológicas, em biópsia muscular, de pacientes gravemente acometidos pela infecção por vírus H1N1 2009. Foi analisada uma série de dez pacientes com infecção confirmada por vírus H1N1, que apresentavam nível sérico elevado de CK. O estudo histológico evidenciou pequenas alterações histoquímicas nas fibras musculares (mais evidentes nas colorações por NADH, SDH, COX, miofosforilase, adenilato deaminase e PAS) mas sem alterações histológicas compatíveis com miopatia inflamatória. Embora nossos pacientes mostrassem níveis séricos elevados de CK, foram poucas as alterações histológicas e histoquímicas encontradas em suas biópsias musculares. Contudo, essas alterações podem ser consistentes com uma disfunção metabólica da fibra muscular associada à infecção pelo H1N1.

Effects of Rocuronium pretreatment on muscle enzyme levels following succinylcholine

Succinylcholine revolutionized anaesthetic practice by providing intense neuromuscular blockade of very rapid onset and ultrashort duration, thereby greatly easing the maneuver of tracheal intubation. However the worth of succinylcholine is limited by the frequent occurrence of muscular side effects which manifest biochemically in the form of rise in serum creatine kinase [CK]. The administration of small doses of nondepolarizing muscle relaxants before the administration of succinylcholine has been shown to decrease the incidence and severity of muscular side effects experienced by the patients. This study was aimed at evaluating the efficacy of technique in reducing the muscular side effects of succinylcholine, biochemically manifested as rise in CK. Sixty healthy adults were enrolled in the study who were scheduled for minor muscle cutting surgeries under general anaesthesia. They were assigned at random to two groups of thirty patients each. They randomly received succinylcholine for intubation and a precurarization dose of Rocuronium followed by succinylcholine for intubation. Blood samples were drawn for estimation of serum creatine kinase. There was a significantly raised CK in the succinylcholine group. In the precurarization group the rise in CK was prevented and the levels were significantly less as compared to the group which received succinylcholine alone. Present study concluded that precurarization with Rocuronium was effective in reducing the succinylcholine-induced rise in creatine kinase

IGF-1 minimiza os efeitos deletérios do desuso no músculo sóleo de ratos / IGF-1 minimizes the harmful effects of disuse on rat soleus muscle

OBJETIVO: Avaliar o efeito do tratamento com IGF-1 sobre o perfil metabólico e morfológico do músculo sóleo submetido à imobilização articular de tornozelo. MÉTODOS: Ratos Wistar foram divididos em 3 grupos (n=6): controle (C), imobilizado (I) e imobilizado tratado com IGF (I+IGF; 40mg/Kg) durante 7 dias. RESULTADOS: A imobilização reduziu o peso (34 por cento), o conteúdo de glicogênio (31,6 por cento) a área das fibras musculares (44 por cento), e elevou na densidade do tecido conjuntivo (216 por cento). Por outro lado, o IGF-1 aumentou o glicogênio em 234,6 por cento quando comparado ao I, minimizou a redução de 33,7 por cento na área das fibras musculares e aumentou de 76 por cento no tecido conjuntivo comparado ao C (p<0,05). CONCLUSÕES: O tratamento com IGF demonstrou uma ação anti-catabólica, fato esse que pode favorecer uma recuperação mais rápida na fase pós-imobilização. Nivel de evidência: Nível II: estudo prospectivo comparativo.

OBJECTIVE: To evaluate the effect of IGF-1 treatment on the morphological and metabolic profile of the soleus muscle submitted to ankle joint immobilization. METHODS: Wistar rats were divided into 3 groups (n = 6): control (C), immobilized (I) and immobilized treated with IGF (I + IGF; 40mg/kg) for 7 days. RESULTS: Immobilization led to a reduction in the weight (34 percent), glycogen content (31.6 percent) and area of muscle fibers (44 percent), and increased the density of connective tissue (216 percent). Also, the IGF-1 increased the glycogen by 234.6 percent compared to I, minimized the area of muscle fibers by 33.7 percent and increased the connective tissue by 76 percent compared to C (p <0, 05). CONCLUSIONS: Treatment with IGF has an anti-catabolic action, which can promote faster recovery in the post-immobilization phase. Level of Evidence: Level II, prospective comparative study.

Characterization of angiotensin-converting enzymes 1 and 2 in the soleus and plantaris muscles of rats

Angiotensin-converting enzymes 1 (ACE1) and 2 (ACE2) are key enzymes of the renin-angiotensin system, which act antagonistically to regulate the levels of angiotensin II (Ang II) and Ang-(1-7). Considerable data show that ACE1 acts on normal skeletal muscle functions and architecture. However, little is known about ACE1 levels in muscles with different fiber compositions. Furthermore, ACE2 levels in skeletal muscle are not known. Therefore, the purpose of this study was to characterize protein expression and ACE1 and ACE2 activities in the soleus and plantaris muscles. Eight-week-old female Wistar rats (N = 8) were killed by decapitation and the muscle tissues harvested for biochemical and molecular analyses. ACE1 and ACE2 activities were investigated by a fluorometric method using Abz-FRK(Dnp)P-OH and Mca-YVADAPK(Dnp)-OH fluorogenic substrates, respectively. ACE1 and ACE2 protein expression was analyzed by Western blot. ACE2 was expressed in the skeletal muscle of rats. There was no difference between the soleus (type I) and plantaris (type II) muscles in terms of ACE2 activity (17.35 ± 1.7 vs 15.09 ± 0.8 uF·min-1·mg-1, respectively) and protein expression. ACE1 activity was higher in the plantaris muscle than in the soleus (71.5 ± 3.9 vs 57.9 ± 1.1 uF·min-1·mg-1, respectively). Moreover, a comparative dose-response curve of protein expression was established in the soleus and plantaris muscles, which indicated higher ACE1 levels in the plantaris muscle. The present findings showed similar ACE2 levels in the soleus and plantaris muscles that might result in a similar Ang II response; however, lower ACE1 levels could attenuate Ang II production and reduce bradykinin degradation in the soleus muscle compared to the plantaris. These effects should enhance the aerobic capacity necessary for oxidative muscle activity.

Allosteric regulation of 6-phosphofructo-1-kinase activity of fat body and flight muscle from the bloodsucking bug Rhodnius prolixus

6-phosphofructo-1-kinase (phosphofructokinase; PFK) activity from Rhodnius prolixus, a haematophagous insect which is usually a poor flyer, was measured and compared in two metabolically active tissues - flight muscle and fat body. The activity of this important regulatory glycolytic enzyme was much more pronounced in muscle (15.1 ± 1.4 U/mg) than in fat body extracts (3.6±0.4 U/mg), although the latter presented higher levels of enzyme per protein content, as measured by western-blotting. Muscle extracts are more responsible than fat body to ATP and fructose 6-phosphate, both substrates of PFK. Allosteric regulation exerted by different effectors such as ADP, AMP and fructose 2,6-phosphate presented a singular pattern for each tissue. Optimal pH (8.0-8.5) and sensitivity to pH variation was very similar, and citrate was unable to inhibit PFK activity in both extracts. Our results suggest the existence of a particular PFK activity for each tissue, with regulatory patterns that are consistent with their physiological roles.

A atividade da fosfofrutocinase (PFK) de Rodnius prolixus, um inseto hematófago, o qual vôa somente pequenas distâncias, foi medida e comparada em dois tecidos metabolicamente ativos - músculo de asa e corpo gorduroso. A atividade desta importante enzima glicolítica regulatória foi muito mais pronunciada em músculo de asa (15,1 ±1,4 U/mg) do que em extrato de corpo gorduroso (3,6 ±0,4 U/mg) embora este último tenha apresentado níveis mais altos da enzima por quantidade de proteína, como medido por western-blotting. Extratos de músculo foram mais responsivos do que corpo gorduroso para ATP e frutose-6-fosfato, ambos substratos da PFK. A regulação alostérica exercida por diferentes efetores tais como ADP, AMP, frutose-2,6-bisfosfato apresentou um padrão singular para cada tecido. O pH ótimo (8,0-8,5) e a sensibilidade a variações de pH, foram muito similares e o citrato foi incapaz de inibir a atividade da PFK em ambos os extratos. Nossos resultados sugerem a existência de uma atividade particular da PFK para cada tecido com padrões regulatórios que são consistentes com suas funções fisiológicas.

Evidence for a natural hybrid of peacock bass (Cichla monoculus vs Cichla temensis) based on esterase electrophoretic patterns

Esterase (Est) and esterase-D (Est-D) electrophoretic patterns identified by starch gel electrophoresis of skeletal muscle protein extracts of 184 specimens of three species of peacock bass, locally known as tucunares (Cichla monoculus, C. temensis and Cichla sp), plus four specimens of a supposed hybrid (C. monoculus vs C. temensis), collected from the Central Amazon, were examined to determine if they could aid in identifying a supposed hybrid between C. monoculus and C. temensis. Six zones of electrophoretic activity were found with these enzyme systems. The Est enzyme showed one zone of activity, formed by bands 1, 2 and 3, plus three zones of activity, presumably controlled by Est-1, 2 and 3 loci. The Est-D enzyme had two zones of activity, presumably controlled by Est-D1 and Est-D2 loci. Cichla monoculus and C. temensis shared band 2 and alleles Est-1(1), Est-2(1), Est-3(2), and Est-D1(1), and therefore these were useless for identifying hybrids between the two species. However, a probable hybrid pattern of bands 1, 2, and 3, presumably generated by a combination of pattern 12 from C. monoculus with pattern 23 from C. temensis, resulting from a possible cross between these two species, was detected. Although the Est-D2 locus cannot be considered an ideal diagnostic marker for identifying the supposed hybrid (C. monoculus vs C. temensis), as it is polymorphic, it proved to be useful for determining the origin of the hybrid, i.e., which parental species were involved in the hybridization process

Ectopic development of skeletal muscle induced by subcutaneous transplant of rat satellite cells

The present study analyzes the ectopic development of the rat skeletal muscle originated from transplanted satellite cells. Satellite cells (10(6) cells) obtained from hindlimb muscles of newborn female 2BAW Wistar rats were injected subcutaneously into the dorsal area of adult male rats. After 3, 7, and 14 days, the transplanted tissues (N = 4-5) were processed for histochemical analysis of peripheral nerves, inactive X-chromosome and acetylcholinesterase. Nicotinic acetylcholine receptors (nAChRs) were also labeled with tetramethylrhodamine-labeled alpha-bungarotoxin. The development of ectopic muscles was successful in 86 percent of the implantation sites. By day 3, the transplanted cells were organized as multinucleated fibers containing multiple clusters of nAChRs (N = 2-4), resembling those from non-innervated cultured skeletal muscle fibers. After 7 days, the transplanted cells appeared as a highly vascularized tissue formed by bundles of fibers containing peripheral nuclei. The presence of X chromatin body indicated that subcutaneously developed fibers originated from female donor satellite cells. Differently from the extensor digitorum longus muscle of adult male rat (87.9 ± 1.0 æm; N = 213), the diameter of ectopic fibers (59.1 æm; N = 213) did not obey a Gaussian distribution and had a higher coefficient of variation. After 7 and 14 days, the organization of the nAChR clusters was similar to that of clusters from adult innervated extensor digitorum longus muscle. These findings indicate the histocompatibility of rats from 2BAW colony and that satellite cells transplanted into the subcutaneous space of adult animals are able to develop and fuse to form differentiated skeletal muscle fibers.

Swimming training increases cardiac vagal activity and induces cardiac hypertrophy in rats

The effect of swimming training (ST) on vagal and sympathetic cardiac effects was investigated in sedentary (S, N = 12) and trained (T, N = 12) male Wistar rats (200-220 g). ST consisted of 60-min swimming sessions 5 days/week for 8 weeks, with a 5 percent body weight load attached to the tail. The effect of the autonomic nervous system in generating training-induced resting bradycardia (RB) was examined indirectly after cardiac muscarinic and adrenergic receptor blockade. Cardiac hypertrophy was evaluated by cardiac weight and myocyte morphometry. Plasma catecholamine concentrations and citrate synthase activity in soleus muscle were also determined in both groups. Resting heart rate was significantly reduced in T rats (355 ± 16 vs 330 ± 20 bpm). RB was associated with a significantly increased cardiac vagal effect in T rats (103 ± 25 vs 158 ± 40 bpm), since the sympathetic cardiac effect and intrinsic heart rate were similar for the two groups. Likewise, no significant difference was observed for plasma catecholamine concentrations between S and T rats. In T rats, left ventricle weight (13 percent) and myocyte dimension (21 percent) were significantly increased, suggesting cardiac hypertrophy. Skeletal muscle citrate synthase activity was significantly increased by 52 percent in T rats, indicating endurance conditioning. These data suggest that RB induced by ST is mainly mediated parasympathetically and differs from other training modes, like running, that seems to mainly decrease intrinsic heart rate in rats. The increased cardiac vagal activity associated with ST is of clinical relevance, since both are related to increased life expectancy and prevention of cardiac events.

(CTG)n expansion at DMPK locus seen only in muscle tissue: a novel case.

Triplet repeat expansion in 3 untranslated region of myotonic dystrophy protein kinase (DMPK) gene has been implicated as causative in myotonic dystrophy (DM). In cases of DM, high levels of somatic instability have been reported, in which inter-tissue repeat length differences as large as 3000 repeats have been observed. This study highlights the inter-tissue (CTG)n expansion variability at the DMPK locus. Molecular analysis of DMPK gene, encompassing the triplet repeat expansion, was carried out in 31 individuals (11 clinically identified DM patients, 20 controls). All controls showed a 2.1kb band (upto 35 CTG repeats), while four cases exhibited an expansion (>50 repeats). A novel observation was made in one case, wherein the DNA from lymphocytes showed a normal 2.1kb band while the muscle tissue DNA from the same patient was heterozygous for normal and 4.3 kb band (>700 repeats). Our results suggested that because inter-tissue variability existed in the (CTG)n repeat number at DMPK locus, an attempt should be made to evaluate affected tissue along with blood wherever possible prior to making a final diagnosis. This is important not only for diagnosis and prenatal analysis, but also while providing genetic counseling to families.

Phosphorylation of ryanodine receptors

Both cardiac and skeletal muscle ryanodine receptors (RyRs) are parts of large complexes that include a number of kinases and phosphatases. These RyRs have several potential phosphorylation sites in their cytoplasmic domains, but the functional consequences of phosphorylation and the identity of the enzymes responsible have been subjects of considerable controversy. Hyperphosphorylation of Ser-2809 in RyR2 (cardiac isoform) and Ser-2843 in RyR1 (skeletal isoform) has been suggested to cause the dissociation of the FK506-binding protein (FKBP) from RyRs, producing "leaky channels," but some laboratories find no relationship between phosphorylation and FKBP binding. Also debated is the identity of the kinases that phosphorylate these serines: cAMP-dependent protein kinase (PKA) versus calmodulin kinase II (CaMKII). Phosphorylation of other targets of these kinases could also alter calcium homeostasis. For example, PKA also phosphorylates phospholamban (PLB), altering the Sarco-endoplasmic reticulum Ca2+ ATPase (SERCA) activity. This review summarizes the major findings and controversies associated with phosphorylation of RyRs.

Efeitos do treinamento físico de alta e baixa intensidades em pacientes com insuficiência cardíaca / Effects of low and high intensity exercise training in patients with chronic heart failure

O exercício físico vem sendo recomendado como coadjuvante no tratamento da insuficiência cardíaca crônica e, apesar do consenso quanto ao ganhos funcionais, sua aplicação clínica ainda é restrita. Os estudos randomizados disponíveis são ainda pequenos e não uniformes quanto à intensidade dos exercícios a serem aplicados. O objetivo primário do presente estudo foi testar duas intensidades de treinamento físico, que diferiam pela presença ou não de acidose metabólica com base no limiar anaeróbico, e analisar seus efeitos na capacidade funcional e na idinâmica dos gases expirados. Como objetivos secundários, analisaram-se as influências dessas intensidades nos níveis sangüíneos de lactato e do peptídeo natriurético tipo B, na variabilidade da freqüência cardíaca, na função e dimensões cardíacas, na capacidade oxidativa muscular esquelética e na qualidade de vida. Estudaram-se 31 homens com idade de 36 a 70 anos com miocardiopatia dilatada de etiologia não-isquêmica, em classe funcional II ou III (New York Heart Association), que foram randomizados em três grupos: exercícios de alta intensidade (n = 11), baixa intensidade (n = 9) e controle (n = 10), com fração de ejeção (média ± erro-padrão) de 26 ± 1%, 31 ± 3% e 27 ± 2%, respectivamente. Todos estavam com medicação otimizada, que não foi modificada durante o estudo. Os pacientes foram submetidos antes e depois do estudo a teste cardiopulmonar máximo em esteira, teste de caminhada de seis minutos em corredor, teste cardiopulmonar de caminhada de seis minutos em esteira, determinação da curva de lactato, dosagem do peptídeo natriurético tipo B em repouso e no pico do exercício, eletrocardiografia dinâmica de 24 horas, ecocardiografia de repouso, biópsia muscular esquelética e escore de qualidade de vida (Minnesota). O programa de treinamento foi supervisionado com três sessões semanais e duração média de seis meses. Envolvia exercícios dinâmicos prescritos com base no teste cardiopulmonar máximo; no grupo de baixa intensidade, eram limitados pela freqüência cardíaca no limiar anaeróbico, e, no de alta, pela freqüência cardíaca no ponto de compensação respiratória. O grupo controle foi apenas acompanhado, sem prescrição de exercícios.