Erratum: Influence of oxygen plasma treatment parameters on poly(vinylidene fluoride) electrospun fiber mats wettability

Electrospun poly(vinylidene fluoride) (PVDF) fiber mats find applications in an increasing number of areas, such as battery separators, filtration and detection membranes, due to their excellent properties. However, there are limitations due to the hydrophobic nature and low surface energy of PVDF. In this work, oxygen plasma treatment has been applied in order to modify the surface wettability of PVDF fiber mats and superhydrophilic PVDF electrospun membranes have been obtained. Further, plasma treatment does not significantly influences fiber average size (~400 ± 200 nm), morphology, electroactive -phase content (~80-85%) or the degree of crystallinity (Xc of 42 ± 2%), allowing to maintain the excellent physical-chemical characteristics of PVDF. Plasma treatment mainly induces surface chemistry modifications, such as the introduction of oxygen and release of fluorine atoms that significantly changes polymer membrane wettability by a reduction of the contact angle of the polymer fibers and an overall decrease of the surface tension of the membranes.

Foregut morphology of Macrobrachium carcinus (Crustacea, Decapoda, Palaemonidae)

ABSTRACT Macrobrachium carcinus is a Brazilian native prawn with recognized potential for use in aquaculture activities. The aim of this study was to describe and illustrate in detail the morphology of the M. carcinus foregut. The foregut comprises the mouth, esophagus and stomach. It is lined by a simple cylindrical epithelium overlain by chitinous cuticle. The cardiac chamber is well supplied with muscles and lined with chitin thickened in places to form a complex, articulating set of ossicles. The ossicles and setae inside the cardiac chamber seem to direct the food movement through the cardiac chamber and sort the food according to particle size as digestion takes place. Twenty-one basic ossicles were observed in the stomach ofM. carcinus and are divided into seven categories, reflecting their presumed functional roles. The significance of these morphological features is discussed in terms of its implication in feeding management that can support future commercial farms of this important fishery resource.

Highly robust chitosan hydrogels via a fast, simple and biocompatible dual crosslinking-based process

Load-bearing soft tissues such as cartilage, blood vessels and muscles are able to withstand a remarkable compressive stress of several MPa without fracturing. Interestingly, most of these structural tissues are mainly composed of water and in this regard, hydrogels, as highly hydrated 3D-crosslinked polymeric networks, constitute a promising class of materials to repair lesions on these tissues. Although several approaches can be employed to shape the mechanical properties of artificial hydrogels to mimic the ones found on biotissues, critical issues regarding, for instance, their biocompatibility and recoverability after loading are often neglected. Therefore, an innovative hydrogel device made only of chitosan (CHI) was developed for the repair of robust biological tissues. These systems were fabricated through a dual-crosslinking process, comprising a photo- and an ionic-crosslinking step. The obtained CHIbased hydrogels exhibited an outstanding compressive strength of ca. 20 MPa at 95% of strain, which is several orders of magnitude higher than those of the individual components and close to the ones found in native soft tissues. Additionally, both crosslinking processes occur rapidly and under physiological conditions, enabling cellsâ encapsulation as confirmed by high cell survival rates (ca. 80%). Furthermore, in contrast with conventional hydrogels, these networks quickly recover upon unloading and are able to keep their mechanical properties under physiological conditions as result of their non-swell nature.

Effects of protein-calorie restriction on mechanical function of hypertrophied cardiac muscle

OBJECTIVE: To assess the effect of food restriction (FR) on hypertrophied cardiac muscle in spontaneously hypertensive rats (SHR). METHODS: Isolated papillary muscle preparations of the left ventricle (LV) of 60-day-old SHR and of normotensive Wistar-Kyoto (WKY) rats were studied. The rats were fed either an unrestricted diet or FR diet (50% of the intake of the control diet) for 30 days. The mechanical function of the muscles was evaluated through monitoring isometric and isotonic contractions. RESULTS: FR caused: 1) reduction in the body weight and LV weight of SHR and WKY rats; 2) increase in the time to peak shortening and the time to peak developed tension (DT) in the hypertrophied myocardium of the SHR; 3) diverging changes in the mechanical function of the normal cardiac muscles of WKY rats with reduction in maximum velocity of isotonic shortening and of the time for DT to decrease 50% of its maximum value, and increase of the resting tension and of the rate of tension decline. CONCLUSION: Short-term FR causes prolongation of the contraction time of hypertrophied muscles and paradoxal changes in mechanical performance of normal cardiac fibers, with worsening of the shortening indices and of the resting tension, and improvement of the isometric relaxation.

Myocardial perfusion by contrast echocardiography. Establishment of normal pattern of intracoronary injection and safety in humans

OBJECTIVE: To establish the normal pattern and safety of echocardiographic contrast in patients with no significant obstruction of epicardial coronary arteries. METHODS: 67 patients with normal coronary arteries or obstructions < 50% were selected from 277 patients who underwent coronary angiography (CA). Mean age was 56 ± 11years and 36 were males. At the end CA, echocardiographic contrast was selectively injected into each coronary artery. The parasternal short axis of the left ventricle (LV) was divided into six segments: anterior (A), antero-lateral (AL), postero-lateral (PL), posterior (P), infero-septal (IS) and antero-septal (AS). Anterolateral (ALPM) and posteromedial papillary muscles (PMPM) were also considered. The pattern and intensity of the appearance of the myocardial contrast was visually analyzed. RESULTS: The right coronary artery (RCA) was dominant in 60 patients. Contrast appearance was sudden and simultaneous in the 3 muscle layers. All segments could be contrasted after the injection in both coronary arteries. 100% of the AS, A and AL segments, 97% of the PL and 98% of the ALPM were perfused by the left coronary artery (LCA). P and IS segments were perfused by the RCA in 85% and 82%, respectively, and by a dominant LCA in 71% of the cases. The PMPM was perfused by a dominant RCA in 77% and by a dominant LCA in 86%. There were no symptoms. CONCLUSION: Intracoronary injection of the sonicated solution is a safe procedure that allows for an excellent opacification of the myocardium and can potentially be used during routine CA.

A new surgical approach for treating dilated cardiomyopathy with mitral regurgitation

OBJECTIVE: To evaluate the early outcome of mitral valve prostheses implantation and left ventricular remodeling in 23 patients with end-stage cardiomyopathy and secondary mitral regurgitation (NYHA class III and IV). METHODS: Mitral valvular prosthesis implantation with preservation of papillary muscles and chordae tendinae, and plasty of anteriun cuspid for remodeling of the left ventricle. RESULTS: The surgery was performed in 23 patients, preoperative ejection fraction (echocardiography) varied from 13% to 44% (median: 30%). In 13 patients associated procedures were performed: myocardial revascularization (9), left ventricle plicature repair (3) and aortic prosthese implantation (1). Early deaths (2) occurred on the 4th PO day (cardiogenic shock) and on the 20th PO day (upper gastrointestinal bleeding), and a late death in the second month PO (ventricular arrhythmia). Improvement occurred in NYHA class in 82.6% of the patients (P<0.0001), with a survival rate of 86.9% (mean of 8.9 months of follow-up). CONCLUSION: This technique offers a promising therapeutic alternative for the treatment of patients in refractory heart failure with cardiomyopathy and secondary mitral regurgitation.

Effect of Propafenone on the Contractile Activity of Latissimus Dorsi Muscle Isolated in an Organ Chamber: Experimental Study in Rats

OBJECTIVE: To study the effect of propafenone on the contractile function of latissimus dorsi muscle isolated from rats in an organ chamber. METHODS: We studied 20 latissimus dorsi muscles of Wistar rats and divided them into 2 groups: group I (n=10), or control group - we studied the feasibility of muscle contractility; group II (n=10), in which the contralateral muscles were grouped - we analyzed the effect of propafenone on muscle contractility. After building a muscle ring, 8 periods of sequential 2-minute baths were performed, with intervals of preprogrammed electrical stimulation using a pacemaker of 50 stimuli/min. In group II, propafenone, at the concentration of 9.8 µg/mL, was added to the bath in period 2 and withdrawn in period 4. RESULTS: In group I, no significant depression in muscle contraction occurred up to period 5 (p>0.05). In group II, a significant depression occurred in all periods, except between the last 2 periods (p<0.05). Comparing groups I and II only in period 1, which was a standard period for both groups, we found no significant difference (p>0.05). CONCLUSION: Propafenone had a depressing effect on the contractile function of latissimus dorsi muscle isolated from rats and studied in an organ chamber.

Development of a subject-specific musculoskeletal shoulder model : inverse and forward dynamics applications

A prevalência de pessoas que referem dor no complexo articular do ombro, com concomitante limitação na capacidade para realizar atividades da vida diária, é elevada. Estes níveis de prevalência sobrecarregam quer os utentes, como a própria sociedade. A evidência científica atual indicia a existência de uma relação entre as alterações da articulação escápulo-torácica e as patologias associadas à articulação gleno-umeral. A capacidade de quantificar, cinemática e cineticamente, as disfunções ao nível das articulações escápulo-torácica e gleno-umeral, é algo de enorme importância, quer para a comunidade biomecânica, como para a clínica. No decorrer dos trabalhos desta tese foi desenvolvido, através do software OpenSim, um modelo tridimensional músculo-esquelético do complexo articular do ombro que inclui a representação do tórax/coluna, clavícula, omoplata, úmero, rádio, cúbito e articulações que permitem os movimentos relativos desses segmentos, assim como, 16 músculos e 4 ligamentos. Com um total de 11 graus de liberdade, incluindo um novo modelo articular escápulo-torácico, os resultados demonstram que este é capaz de reconstruir de forma precisa e rápida os movimentos escápulo-torácicos e glenoumerais, recorrendo para tal, à cinemática inversa, e à dinâmica inversa e direta. Conta ainda com um método de transformação inovador para determinar, com base nas especificidades dos sujeitos, os locais de inserção muscular. As principais motivações subjacentes ao desenvolvimento desta tese foram contribuir para o aprofundar do atual conhecimento sobre as disfunções do complexo articular do ombro e, simultaneamente, proporcionar à comunidade clínica uma ferramenta biomecânica de livre acesso com o intuito de melhor suportar as decisões clínicas e dessa forma concorrer para uma prática mais efetiva.

Obesity Preserves Myocardial Function During Blockade of the Glycolytic Pathway

Background: Obesity is defined by excessive accumulation of body fat relative to lean tissue. Studies during the last few years indicate that cardiac function in obese animals may be preserved, increased or diminished. Objective: Study the energy balance of the myocardium with the hypothesis that the increase in fatty acid oxidation and reduced glucose leads to cardiac dysfunction in obesity. Methods: 30-day-old male Wistar rats were fed standard and hypercaloric diet for 30 weeks. Cardiac function and morphology were assessed. In this paper was viewed the general characteristics and comorbities associated to obesity. The structure cardiac was determined by weights of the heart and left ventricle (LV). Myocardial function was evaluated by studying isolated papillary muscles from the LV, under the baseline condition and after inotropic and lusitropic maneuvers: myocardial stiffness; postrest contraction; increase in extracellular Ca2+ concentration; change in heart rate and inhibitor of glycolytic pathway. Results: Compared with control group, the obese rats had increased body fat and co-morbities associated with obesity. Functional assessment after blocking iodoacetate shows no difference in the linear regression of DT, however, the RT showed a statistically significant difference in behavior between the control and the obese group, most notable being the slope in group C. Conclusion: The energy imbalance on obesity did not cause cardiac dysfunction. On the contrary, the prioritization of fatty acids utilization provides protection to cardiac muscle during the inhibition of glycolysis, suggesting that this pathway is fewer used by obese cardiac muscle.

Morphological and functional study of the marginal sphincter of the sea anemones Phymactis clematis and Aulactinia marplatensis from intertidal of Mar del Plata, Argentina

It was made the characterization of marginal sphincter to the species Phymactis clematis (Drayton in Dana, 1849) and Aulactinia marplatensis (Zamponi, 1977), from intertidal ecosystem through their morphogical and functional study. The species P. clematis has a circumscript sphincter of palmate type. This muscle is constituted by a mesogloeal axis and several mesogloeal subaxes. Axis as well as subaxes give a support to the endoderm which border is smooth. Aulactinia marplatensis has a circunscript sphincter pinnate type. The axis has a truncated cone shape while in P. clematis the shape is cylindrical on its origin and it is bifurcated at the end. Both species experiments were carried out using the isolated muscles. They were stimulated at increasing KCl concentrations ranging from 20 to 200 mM. The results were analysed in the form of dose-response curves expressed in tension in grams force vs concentration. Contractil force increases in a sigmoid form to increasing KCl concentrations. The correlation between morphology and function and the differences shown in both species would be related to their intertidal distribution.

Estudos sôbre a excitação química da córtex cerebral (Ação da acetilcolina)

The author has studied the influence of acetylcholine solutions directly applied on the motor cortex of dogs, cats monkeys and rabbits. For this purpose small squares of filter paper were soaked in the acetylcholine solution and soon afterwards laid on the motor cortex. Solutions varying from 0,2 to 10 per cent have been experimented. It has been shown that local application of the solutions on the motor points, previously localized by induction coil, produced motor reactions. It has been found, in the dogs that 10 per cent acetylcholine solutions cause localized muscular twitchings (clonus) in almost all the animals experimented. Generalised epileptiform convulsions were obtained in44,4% of the dogs. Convulsions were also obtained by employing 1 per cent solution of acetylcholine. Definite response has been obtained with 0,2 per cent solution. Failure of motor action, pointed out by other authors, has been related to the use of anesthetics. Convulsions were easily produced by rapid light mechanical stimulations of the skin covering the muscles in conection with the excited motor point, and the application on the motor point of acetylcholine. The results on monkeys can be summarized as follows. Two species of monkeys were experimented: Cebus capucinus and Macaca mulata. In the monkeys C. capucinus generalised convulsive reactions were induced with actylcholine solutions in a concentration as low as 0,5 per cent. Motor reaction or convulsive seizeres were obtained in seven of the eight monkeys used. Three monkeys M. mulata were stimulated with 10 per cent acetylcholine solution but only localized muscular contraction hae been observed. Similar results has been obtained on the motor cortex of cats and rabbits. One of the three cats employed has shown epileptiform convulsions and the remaining only localized muscular contractions. In the rabbits muscular twitchings have been also induced. The sensitizing power of eserine on the action of acetylcholine has been also searched. The results indicate that a previous application of eserine solution on the motor center, potentiates the action of acetylcholine. The intensity of the muscular twitchings is greater than the obtained before the application of the eserine solution. Generalised epileptiform convulsions sometimes appeared following the use of lower concentrations of acetylcholine than those previously employed. Experiments have been carried out by injecting eserine and prostigmine by parenteral route. A dosis dufficient for induce small muscular tremors did not enhance obviously the motor effects produced by the application of the acetylcholine solutions on the motor cortex. From seven dogs experimented, all previously tested for convulsive seiruzes by application of 1 and 10 per cent acetylcholine solution with negative results, only one has shown epileptiform convulsions after the injection of prostigmine. Morphine has also been tested as facilitating substance for convulsions induced by acetylcholine. Six from the nine dogs submitted to the experiments, developed epileptiform seizures after injection of morphine and stimulation of the motor cortex with acetylcholine. (Table IV). In another series of experiments atropine and nicotine have been studied as for to their action on the motor effects of acetylcholine. Nicotine has a strong convulsant action, even when employed in very high concentration. Since a depressant effect has not appeared even by the applications of high concentrations of nicotine in the motor corteõ of dogs, unlike the classical observations for the autonomus nervous system, it was not possible to verify the action of acetylcholine on a motor center paralised by nicotine. It is important to not that the motor phenomena observed after the first aplication of acetylcholine, can desappear by the renewal of the pieces of filter paper soaked in the acetylcholine solution. Atropine, either applied on the motor point in low concentration, or injected in sufficient amount for inhibiting the “muscarinic effects” of acetylcholine on the autonomous nervous system, did not prevent the motor reactions of acetylcholine on the cerebral cortex.

Toxoplasmose congênita

We had the opportunity to study 6 cases of the congenital form of toxoplasmosis, found in a series of 1200 necropsies of fetuses and newborn babies, realized at 3 different hospitals in Rio de Janeiro, Brazil. Among the 6 cases, 4 were premature babies liveborn at the 6th-8th gestational month and 2 were stillborn (1 premature and 1 at term). In all those cases, the diagnosis was based in the detection of the parasite in tissues and in one case it was even isolated the Toxoplasma from the necrotic material found in the cranial cavity. This strain of Toxoplasma, pathogenic to pigeons, to guinea pigs and to mice, is preserved by successive transfers in mice. Some facts observed in those cases present an interest not only strictly anatomic but also have certain value for the better acknowlegment of the disease. First, we want to call the attention to the presence of a sudden high fever, during or just before pregnancy in the 4 cases in which the maternal anamnesis was perfectly studied; this fever that was preceded by a normal beginning of pregnancy, had relatively rapid remission, but in 2 cases was immediately followed by uterine bleeding and premature delivery, although the puerperium had been apparently normal. It is known that are normal the subsequent children of the mothers that delivered a baby with toxoplasmosis and that several women have normal babies before the toxoplasmotic one. We believe that the fever observed in our cases could be indicative of the beginning of maternal infection and those are the reasons why we emphasize the need of careful anamnesis, specially in the cases actually diagnosed as inapparent infection. Another fact to notice is that in 5 of our cases the event premature delivery happened always between the 6th and the 8th months of pregnancy, and the only term fetus was delivered in advanced stage of maceration. The above mentioned facts could agree with the opinion of FRENKEL (1949), when he declared that "primary infection of the pregnant mother appears more likely to be the commoner mode of fetal toxoplasmic infection", but they would disagree with WEINMAN (1952) who believes that the transmission of Toxoplasma to the fetus is more frequent through a pregnant woman with chronic disease and who says "that infection contracted during pregnancy may and probably does happen from time to time"...Still in connection with the transmission of toxoplasmosis, we want to note the verification of inflammatory lesions in the placental villi and in the umbilical cord in 3 of the 4 cases in which such organs were examined at the microscope. In the case n. 1, we found several pseudocysts of Toxoplasma in the placenta, and the fibroblasts of Wharton's jelly were particularly rich in isolated forms and in colonies of Toxoplasma; the easy multiplication of the parasite in that tissue calls the attention and even suggests its utilisation for Toxoplasma's cultivation. The confirmation of Toxoplasma in human placenta was made only recently by CRISTEN et al. (1951) and by NEGHME et al. (1952), in Chile; it is not frequent in the literature, what gives some value to our present verification. Another observation was that provided by the case n. 6. This baby, a premature one of the 6th month, was 14 days old and-died with signs of respiratory disease, the causa mortis have been pneumonia. At the necropsy, we found no gross change that suggested toxoplasmosis, except the presence of some small necrotic focuses in the cerebral nervous substance around the ventricles. As a matter of fact, there was no enlargement of spleen or liver and neither leptomeningitis nor hydrocephalus. Such focuses were attributed to possible anoxia and in fact they are extremely similar to anoxial softenings, even when they are examined at the microscope; its structure composed of a central necrotic zone, surrounded by proliferated neuroglia and by a variable deposit of calcium salts, closely simulated the anoxial softenings, when the microscopical examination is based in the common histological preparations (hematoxilin-eosin, etc.). But when we examine preparations by the Giemsa or by the periodic acid-Schiff methods, we will note the presence of Toxoplasma, with its typical aspect or a little changed by degeneration. When we describe this observation, we wish to evidence the need of the search of Toxoplasma and closed parasites, in the cases of supposed pure anoxial softenings of nervous substance, in children. The frequency with which the congenital toxoplasmosis was anatomically verified should be emphasized, although the disease had not been clinically suspected, and it should be borne in mind that the second case of toxoplasmosis reported in the world was observed in Brazil by MAGARINOS TORRES; this case was the first to be described of the generalized congenital form of the infection, i. e. with myocardial lesions and parasites in skeletal muscles and skin.

An outbreak of dengue virus at Rio de Janeiro - 1986

Dengue virus type 1 has been isolated in Aedes albopictus cell strain, from sera of patients living in the Nova Iguaçu county, by Rio de Janeiro. The clinical picture was characterized by fever, headache, retrobulbar pain, backache, pains in the muscles and the joints and prostration. Studies in paired sera confirmed the presence of recent infection by dengue virus type 1. The outbreak reached adjacent areas, including Rio de Janeiro city (May, 1986).