Otimização e validação de método multirresíduo para determinação de sulfonamidas em camarão cultivado por cromatografia líquida de alta eficiência com detecção por UV

This work reports the optimization and method validation for sulfonamides (sulfamethazine, sulfaquinoxaline, sulfadimethoxine and sulfathiazole) in shrimp muscle using HPLC-UV. The sulfonamides were extracted with acetonitrile and acetic acid, and the extract cleaned up with a Strata SCX SPE cartridge prior to analysis. The method presented linearity in the range of 20-120 µg kg-1, good linear correlation (r > 0.99), and limits of quantification in the range of 4.7-20.2 µg kg-1. The recovery for shrimp muscles spiked with 50-150 µg kg-1 ranged from 63.2-108.0%. Precision and accuracy analysis showed acceptable relative standard deviation. Commercial shrimps were analyzed and sulfonamides don't were found above of the method limit of quantification.

Simple method for mass production of polypyrrole/carbon nanotubes hybrid artificial muscle

Large scale preparation of hybrid electrical actuators represents an important step for the production of low cost devices. Interfacial polymerization of polypyrrole in the presence of multi-walled carbon nanotubes represents a simple technique in which strong interaction between components is established, providing composite materials with potential applications as actuators due to the synergistic interaction between the individual components, i.e., fast response of carbon nanotubes, high strain of polypyrrole, and diversity in the available geometry of resulting samples.

The Regulation of Skeletal and Cardiac Muscle Blood Flow in Humans. Studies by positron emission tomography with special reference to exercise, adenosine and nitric oxide

Virtually every cell and organ in the human body is dependent on a proper oxygen supply. This is taken care of by the cardiovascular system that supplies tissues with oxygen precisely according to their metabolic needs. Physical exercise is one of the most demanding challenges the human circulatory system can face. During exercise skeletal muscle blood flow can easily increase some 20-fold and its proper distribution to and within muscles is of importance for optimal oxygen delivery. The local regulation of skeletal muscle blood flow during exercise remains little understood, but adenosine and nitric oxide may take part in this process. In addition to acute exercise, long-term vigorous physical conditioning also induces changes in the cardiovasculature, which leads to improved maximal physical performance. The changes are largely central, such as structural and functional changes in the heart. The function and reserve of the heart’s own vasculature can be studied by adenosine infusion, which according to animal studies evokes vasodilation via it’s a_2A receptors. This has, however, never been addressed in humans in vivo and also studies in endurance athletes have shown inconsistent results regarding the effects of sport training on myocardial blood flow. This study was performed on healthy young adults and endurance athletes and local skeletal and cardiac muscle blod flow was measured by positron emission tomography. In the heart, myocardial blood flow reserve and adenosine A_2A receptor density, and in skeletal muscle, oxygen extraction and consumption was also measured. The role of adenosine in the control of skeletal muscle blood flow during exercise, and its vasodilator effects, were addressed by infusing competitive inhibitors and adenosine into the femoral artery. The formation of skeletal muscle nitric oxide was also inhibited by a drug, with and without prostanoid blockade. As a result and conclusion, it can be said that skeletal muscle blood flow heterogeneity decreases with increasing exercise intensity most likely due to increased vascular unit recruitment, but exercise hyperemia is a very complex phenomenon that cannot be mimicked by pharmacological infusions, and no single regulator factor (e.g. adenosine or nitric oxide) accounts for a significant part of exercise-induced muscle hyperemia. However, in the present study it was observed for the first time in humans that nitric oxide is not only important regulator of the basal level of muscle blood flow, but also oxygen consumption, and together with prostanoids affects muscle blood flow and oxygen consumption during exercise. Finally, even vigorous endurance training does not seem to lead to supranormal myocardial blood flow reserve, and also other receptors than A_2A mediate the vasodilator effects of adenosine. In respect to cardiac work, atheletes heart seems to be luxuriously perfused at rest, which may result from reduced oxygen extraction or impaired efficiency due to pronouncedly enhanced myocardial mass developed to excel in strenuous exercise.

Fasciíte necrotizante limitada a região pré-peritoneal

Our objective is to report a case of a patient with necrosis limited to the pre-peritoneal fascia and fat tissue of the abdomen and pelvis. A 34-year-old female presented with fever, chills, nausea, diarrhea and abdominal pain. She denies history of trauma, diabetes mellitus, use of immunosuppressive drugs, smoking, and drug dependence. Laboratory tests revealed hematocrit of 28.7%, white blood count of 12.200/mm3 with 49% of bands, platelets of 317.000/mm3, and sedimentation rate of 65 mm/hr. She was subjected to an abdominal ultrasonography and computed tomography that showed hepatosplenomegaly and muscular thickening on the left flank. Surgical debridment was performed. There was necrosis limited to the pre-peritoneal fascia and fat tissue extending from the pelvis to the left flank. The fascia of the superficial muscles and the subcutaneous fat were normal. The pathologic examination showed suppuration and necrosis of the tissues. Antibiotics were administered and ten debridments were performed. The patient was discharged 30 days after the admission.

Cirurgia do hiperparatireoidismo

Hyperparathyroidism is a desease caused by increase of parathormone secretion, leading to a misfunction of calcium metabolism. Although not very common among population in general, it is frequently observed in patients with cronic renal disease. It can involve a slight syntomatic form, but as a whole, its main repercurssions occur in skeletic muscles, urinary and intestinal systems. The authors conduct a broad revision of the literature, focusing on the methods of diagnosis and spot checking before and during the operations of parathyroid glands. Surgical recommendations, tatic aspects and types of surgery to be implemented are discussed. A systematization for adequate surgical technics performed at the General Surgery Service of Clementino Fraga Filho Hospital of Federal University of Rio de Janeiro is fully discribed and recommended.

Estudo das alterações ultra-estruturais em pleura de ratos pós pleurodese por talco

OBJETIVO: O talco é considerado um agente efetivo de pleurodese freqüentemente utilizado no tratamento de derrame pleural maligno. Entretanto, questiona-se sua segurança em relação à carcinogênese. O objetivo deste trabalho é descrever as alterações ultra-estruturais encontradas nas pleuras de ratos submetidos à pleurodese com talco buscando esclarecer sua segurança em relação à carcinogênese. MÉTODO: Neste estudo randomizado foram utilizados seis ratos machos do tipo Wistar, pesando 250 g. Através de uma toracotomia mínima no quinto espaço intercostal esquerdo foi colocado lavado de talco em concentrações de 0,5mg (n=2) e 0,1 mg (n=2) de talco por grama de peso. Dois ratos foram apenas anestesiados e foi instilado solução fisiológica (NaCl 0,9%) intrapleural para configurar o grupo controle. Os ratos foram mortos após 45 dias. As alterações morfológicas e morfométricas ultra-estruturais foram analisadas através de microscopia eletrônica de transmissão. RESULTADOS: A análise ultra-estrutural das pleuras submetidas à talcagem demonstrou desorganização celular do tecido conjuntivo, evidenciando alterações nucleares, mitocondriais e espessamento da camada submesotelial. O grupo controle manteve a arquitetura celular preservada. CONCLUSÕES: Este estudo revelou alterações da estrutura celular da pleura exposta ao talco quando comparado ao grupo controle.

Hemipelvectomia externa ampliada para tratar adenocarcinoma de sigmóide

Surgery is the most effective way of treating a locally advanced colorectal carcinoma and an extended en bloc resection is necessary to achieve the best overall survival rate. In this rare case, a multi-visceral resection was performed along with the entire lower left limb and left iliac bone for a sigmoid carcinoma. The T4N0M0 (B3) tumor involved the left iliac vessels, left pelvic wall, small bowel and both rectus muscles, besides presenting with a skin fistula. A Hartmann colostomy was also performed. Chemotheraphy was interrupted because of toxicity. The patient is free of disease after 38 months. There are very few cases that describe an extended hemipelvectomy as part of a colorectal carcinoma treatment.

Flexible multibody approach in bone strain estimation during physical activity:

Bone strain plays a major role as the activation signal for the bone (re)modeling process, which is vital for keeping bones healthy. Maintaining high bone mineral density reduces the chances of fracture in the event of an accident. Numerous studies have shown that bones can be strengthened with physical exercise. Several hypotheses have asserted that a stronger osteogenic (bone producing) effect results from dynamic exercise than from static exercise. These previous studies are based on short-term empirical research, which provide the motivation for justifying the experimental results with a solid mathematical background. The computer simulation techniques utilized in this work allow for non-invasive bone strain estimation during physical activity at any bone site within the human skeleton. All models presented in the study are threedimensional and actuated by muscle models to replicate the real conditions accurately. The objective of this work is to determine and present loading-induced bone strain values resulting from physical activity. It includes a comparison of strain resulting from four different gym exercises (knee flexion, knee extension, leg press, and squat) and walking, with the results reported for walking and jogging obtained from in-vivo measurements described in the literature. The objective is realized primarily by carrying out flexible multibody dynamics computer simulations. The dissertation combines the knowledge of finite element analysis and multibody simulations with experimental data and information available from medical field literature. Measured subject-specific motion data was coupled with forward dynamics simulation to provide natural skeletal movement. Bone geometries were defined using a reverse engineering approach based on medical imaging techniques. Both computed tomography and magnetic resonance imaging were utilized to explore modeling differences. The predicted tibia bone strains during walking show good agreement with invivo studies found in the literature. Strain measurements were not available for gym exercises; therefore, the strain results could not be validated. However, the values seem reasonable when compared to available walking and running invivo strain measurements. The results can be used for exercise equipment design aimed at strengthening the bones as well as the muscles during workout. Clinical applications in post fracture recovery exercising programs could also be the target. In addition, the methodology introduced in this study, can be applied to investigate the effect of weightlessness on astronauts, who often suffer bone loss after long time spent in the outer space.

Four-arm single docking full robotic surgery for low rectal cancer: technique standardization

The authors present the four-arm single docking full robotic surgery to treat low rectal cancer. The eight main operative steps are: 1- patient positioning; 2- trocars set-up and robot docking; 3- sigmoid colon, left colon and splenic flexure mobilization (lateral-to-medial approach); 4-Inferior mesenteric artery and vein ligation (medial-to-lateral approach); 5- total mesorectum excision and preservation of hypogastric and pelvic autonomic nerves (sacral dissection, lateral dissection, pelvic dissection); 6- division of the rectum using an endo roticulator stapler for the laparoscopic performance of a double-stapled coloanal anastomosis (type I tumor); 7- intersphincteric resection, extraction of the specimen through the anus and lateral-to-end hand sewn coloanal anastomosis (type II tumor); 8- cylindric abdominoperineal resection, with transabdominal section of the levator muscles (type IV tumor). The techniques employed were safe and have presented low rates of complication and no mortality.