Parasitos em trutas-arco-íris (Oncorhynchus mykiss) criadas em sistema intensivo na região serrana de Santa Catarina, Brasil / [Parasites in rainbow trout (Oncorhynchus mykiss) raised in an intensive system in the mountain region of Santa Catarina, Brazil]

With the aim to determine the prevalence and mean parasite intensity in Oncorhynchus mykiss, 120 specimens were analyzed between April and September 2018. The cavity analysis was done by visual inspection, scraping of mucus, and extraction of the branchial arches. In the evisceration process, the intestine, the liver, and the kidney were separated, while the musculature was analyzed using the "candling table" method. All the collected material was preserved in 10% buffered formaldehyde and sent to the Laboratory of Parasitology and Parasitic Diseases, of the Center for Agroveterinary Sciences (CAV) of the University of the State of Santa Catarina (UDESC) for making the slides and identifying the parasites. Parasites were detected only in the analysis of the scraping of body mucus. Only specimens of the genus Trichodina were identified, in 34 of the 120 fish analyzed, in two collections, resulting in a prevalence of 28.33%. In total, 144 specimens of Trichodina were observed. The overall mean intensity was of 4.24 parasites in each fish analyzed. Characteristic lesions of infection by protozoa were not identified. This is the first report of the occurrence of Trichodina spp. in O. mykiss bred in an intensive system in Brazil, with low rates of parasitic infection in the mountain region of Santa Catarina.(AU)

STM-electroluminescence from clustered C3N4 nanodomains synthesized via green chemistry process.

A Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and synchrotron X-ray diffraction study on clustered C3N4 nanoparticles (nanoflakes) is conducted on green-chemistry synthesized samples obtained from chitosan through high power sonication. Morphological aspects and the electronic characteristics are investigated. The observed bandgap of the nanoflakes reveals the presence of different phases in the material. Combining STM morphology, STS spectra and X-ray diffraction (XRD) results one finds that the most abundant phase is graphitic C3N4. A high density of defects is inferred from the XRD measurements. Additionally, STM-electroluminescence (STMEL) is detected in C3N4 nanoflakes deposited on a gold substrate. The tunneling current creates photons that are three times more energetic than the tunneling electrons of the STM sample. We ponder about the two most probable models to explain the observed photon emission energy: either a nonlinear optical phenomenon or a localized state emission.

Measurement of interchain and intrachain exciton hopping barriers in luminescent polymer.

The integrated photoluminescence intensity in thin films of 'Super Yellow' copolymer has been analyzed using a Mott-like temperature dependence. This has enabled us to observe contributions from two emission channels, indicative of exciton recombination proceeding from two distinct origins. At high temperature, interchain thermally activated exciton energy transfer and migration dominates, resulting in large scale quenching of the integrated emission intensity and hence the photoluminescence quantum yield. However, at relatively low temperature, an additional increase of the integrated emission intensity occurs. This new channel of emission has been attributed to recombination from excitons where intrachain exciton energy transfer between adjacent subunits of the copolymer backbone becomes hindered. The activation energy barriers that control both of these emission channels have been obtained and are correlated with chain backbone degrees of freedom.

Role of myocardial ischemia and left ventricular wall motion abnormalities as contributory factors in the genesis of exercise-induced ST-segment elevation in Q-wave myocardial infarction.

In patients with a previous myocardial infarction, controversy exists regarding the significance of postexercise ST-segment elevation in the infarct-related leads. Although usually admitted to be a sign of left ventricular dysfunction or myocardial aneurysm, other studies however have related this finding to transient myocardial ischemia and to the presence of jeopardized but viable myocardium in the infarct area. The aim of the present study was to assess the significance of postexercise ST-segment elevation in Q-wave leads as a marker of transmural ischemia or left ventricular dysfunction in 36 consecutive patients, 16 with exercise-induced ST-segment elevation in infarct-related leads. Patients were evaluated by treadmill exercise testing, coronary angiography and ventriculography, thallium-201 tomographic scintigraphy and radionuclide ventriculography within 3 months of the first myocardial infarction. Sixteen patients (group I) had exercise-induced ST segment elevation and 20 (group II) postexercise inversion, no change or pseudonormalization of the T wave in infarct-related leads. The study showed no difference in infarct-related artery, vessel disease or luminal diameter stenosis in groups I and II. The overall agreement between ST shifts and myocardial perfusion in the infarct area was 30.56% with a kappa coefficient of -0.33 (p = NS). The overall agreement between ST shifts and wall motion abnormalities was 69.44% with a kappa coefficient of 0.39 (p < 0.01), stress-induced ST-segment elevation being associated with severe wall contractile disorders in 85% of the patients. In conclusion stress-induced ST-segment elevation in Q wave leads, although not a marker of wall motion abnormalities, is associated with akinesia or dyskinesia of the left ventricular wall.

Post-exercise electrocardiographic alterations, ST-segment elevation and QTc changes in patients with recent myocardial infarction.

UNLABELLED: Stress-induced ST-segment elevation and a prolongation or no change of the QTc ratio (corrected QT interval for heart rate) at maximal exercise in the infarct leads have been associated with the presence of residual myocardial ischemia in the infarct zone. The aim of this study was to test the agreement between stress-induced ST-segment elevation and post-exercise QTc changes in infarct leads, in 36 consecutive patients, studied by coronariography, radionuclide ventriculography and thallium-201 scintigraphy, within 3 months of the acute myocardial infarction. Sixteen patients (Group I) had exercise-induced ST-segment elevation in the infarct leads and 20 did not (Group II). The study showed no significant difference between severity of vessel disease and occlusion, prevalence of the infarct related artery or left ventricular dysfunction in Group I and II. No agreement between ST-segment shifts and myocardial perfusion in the infarct zone was found. Resting wall motion abnormalities were more severe in Group I than in Group II (p < 0.01). In the total of the 36 patients there was no agreement between ST-segment shifts and QTc-variations. The study showed agreement between QTc changes and myocardial perfusion in the infarct area (K = 0.64) (p < 0.001). CONCLUSION: This study showed no relation between post-exercise ST elevation and post-exercise QTc variations in Q wave leads. QTc variations at the end of exercise in the infarct related leads identified residual ischemia. Exercise ST segment elevation, although not a marker of ischemia, is associated with more severe wall motion abnormalities in the infarct zone.

Comparison between dobutamine echocardiography and thallium-201 scintigraphy in detecting residual stenosis, ischemia, and necrosis in patients with prior myocardial infarction.

BACKGROUND: Following the first attempts to detect myocardial ischemia with two-dimensional echocardiography stress testing, pharmacologic stress using dobutamine infusion has become an alternative to echocardiography exercise testing for evaluation of coronary artery disease. It has been shown that stress echocardiography has a diagnostic accuracy similar to that of an exercise thallium test. Other studies, however, indicated that radionuclide myocardial perfusion imaging was more sensitive than exercise or pharmacologic stress echocardiography for detection of ischemia or jeopardized myocardium. HYPOTHESIS: The aim of the present study was to determine the ability of dobutamine stress echocardiography in comparison with thallium-201 scintigraphy to identify multivessel disease and the presence of myocardial scar and ischemia in 60 consecutive patients who suffered a first myocardial infarction (MI). METHODS: Patients were evaluated by coronary angiography and ventriculography, thallium-201 (201TI) tomographic scintigraphy, and dobutamine echocardiography within 3 months of a first MI. Forty-seven had Q-wave MI and 13 had non-Q-wave MI. Eleven patients were excluded from final analysis-7 because of failure to achieve target heart rate in spite of the use of atropine, and 4 because of high blood pressure following the infusion of dobutamine. RESULTS: Dobutamine echocardiography showed an overall sensitivity of 43% for detection of coronary artery lesions of 50-74% diameter stenosis and 201TI scintigraphy showed a sensitivity of 71%. For detection of lesions of > or = 75% diameter stenosis, dobutamine echocardiography showed a sensitivity of 52% and 201TI a sensitivity of 70%. Overall agreement between wall motion and myocardial perfusion for detection of necrosis and/or ischemia in the infarct area was 40.4% with a kappa coefficient of 0.09 (p = 0.13). For detection of ischemic myocardium outside the infarct zone, overall agreement was 78.6% with a kappa coefficient of 0.49 (p < 0.0001). CONCLUSION: Dobutamine echocardiography results showed a lower sensitivity than myocardial perfusion images in predicting multivessel coronary artery disease, and there was poor agreement between both methods in identifying necrosis or ischemia.

[Electrocardiographic changes after coronary angiography: effect of the contrast media used]. / Alterações electrocardiográficas após coronariografia: influência do contraste utilizado.

UNLABELLED: Prospective study to evaluate the influence of 2 different iodine contrasts (used in coronariography) on the electrocardiographic changes recorded after intra-coronary injection. MATERIAL AND METHODS: Sixty-six patients (pts) - 50 men and 16 women - 59 +/- 4 years underwent coronariography to confirm and/or evaluate coronary artery disease (CAD). Group I (33 pts) received a hyperosmolar contrast; group II received a low osmolarity contrast. The electrocardiograms were recorded during and until 20 seconds after intra-coronary injection, in standard leads and V5. Tracings were analysed regarding the development of: arhythmias, mean axis deviation and QRS enlargement - type A abnormalities; ventricular repolarization (ST/T) changes - type B abnormalities. ECG changes were compared with: 1. contrast used; 2. presence (or absence) of CAD; 3. correlation between type B abnormalities and the arteries affected. RESULTS: 1. a) Twenty nine pts (88%) of group I had A and/or B electrocardiographic changes, compared with 16 (48%) of group II (p < 0.01). b) There were type A changes in 13 pts of group I (39%) versus 3 pts (9%) of group II (p < 0.01). c) Type B changes were present in 25 pts (76%) of group I and in 20 pts (60%) of group II (p-NS). 2. a) Type A abnormalities were recorded in 13 of 48 pts with CAD (27%) against 3 of 18 (17%) cases with normal coronariography (p-NS). b) Type B abnormalities were present in 30 of 48 pts (63%) with CAD and in 10 of 18 cases (56%) of people with normal coronariography (p-NS). 3. In 21 pts with isolated right (or left) CAD, contrast injection in the right coronary artery induced type B ECG changes on the homo-lateral supplied territory in 14 cases, no change at all in 4 cases and changes in the contra-lateral area in only 3 pts. Injections in the left coronary artery produced similar results. CONCLUSIONS: 1. Hyperosmolar contrast produced significantly more electrocardiographic abnormalities, mainly type A, than low osmolarity contrast. This one may be, therefore, preferable. 2. Both types of electrocardiographic changes were equally recorded in pts with CAD and in people with normal coronariography. 3. Type B changes seem to be related with the location of the injection, irrespective of the presence or absence of coronary artery disease.

[Dobutamine stress echocardiography in patients after an acute myocardial infarct: what is the significance of arterial patency related to the infarct?]. / Ecocardiografia de sobrecarga com dobutamina nos doentes pós-enfarte agudo do miocárdio: qual a importância da permeabilidade da artéria relacionada com o enfarte?

BACKGROUND: Dobutamine stress echocardiography is a very promising technique for assessing myocardial viability, ischemia and prognosis in patients with a recent acute myocardial infarction. Recent studies have shown that the type of perfusion in the infarct-related artery also plays a role in the prognosis of these patients. PURPOSE: To evaluated in patients with non complicated infarction the ability of low-dose and high-dose dobutamine stress echocardiography to assess the presence of both viability and inducible ischemia and correlate the results with the patency of the infarct related artery and the accuracy to predict cardiac events during one year follow-up. PATIENTS AND METHODS: Fifty one consecutive in-hospital patients (47 male and four female, mean age 52 +/- 11 years, range 31-75 years) with acute myocardial infarction were evaluated both by dobutamine stress echocardiography and by coronary angiography and followed-up for a mean of 12 +/- 8 months. RESULTS: With low-doses of dobutamine, the incidence of myocardial viability was 33% and with high-doses, the incidence of residual inducible ischemia was 41%. The patency of infarct-related artery showed significant correlation with score wall motion index for viability and for myocardial ischemia. Twenty four (47%) patients suffered cardiac events. Dobutamine stress echocardiography showed a positive predictive value of 67% and a negative of 70% and identified high and low risk patients. CONCLUSIONS: Dobutamine stress echocardiography in patients with acute myocardial infarction is a safe and well tolerated test, and provides in a single test useful information regarding viability, ischemia and prognosis.

Minimal residual coronary obstructions in patients who suffered a first myocardial infarction. A prospective study comparing coronary angiography and exercise thallium scintigraphy.

The purpose of the present study was to correlate the presence of minimal coronary obstruction (< or = 50%) assessed by coronary angiography with the presence of myocardial scar and ischemia detected by thallium-201 myocardial perfusion imaging. The study included 83 consecutive patients (74 men and 9 women) with a mean age 55.4 +/- 8.5 years who suffered a first myocardial infarction and did not undergo thrombolytic therapy. In all patients, coronary angiography, left ventriculography, and exercise thallium-201 tomographic scintigraphy were performed within 3 to 5 months of the myocardial infarction. Coronary arteriograms showed minimal residual obstructions in 37 (45%) patients. Of a total of 54 patients with < or = 50% obstruction, 18 showed persistent defects and 22 reversible defects on thallium scintigrams. The present study showing estimated angiographic stenosis of < or = 50% as being responsible either for myocardial scar or myocardial ischemia on postexercise thallium scintigrams leads us to conclude that percent value of stenosis does not accurately predict the pathophysiologic significance of coronary atherosclerotic lesions in patients who suffer a myocardial infarction. After a first myocardial infarction, coronary angiographies and thallium-201 scintigrams are complementary for an optimal treatment strategy for selected subsets of patients.

Postexercise changes of the QTc interval in patients with recent myocardial infarction.

A lack of the QTc ratio decrease at maximal exercise is considered as an index of exercise-induced ischemia in patients with coronary artery disease. The authors studied 51 patients with recent myocardial infarction in order to evaluate the QTc changes with exercise in assessing the presence of remaining ischemic myocardium. All patients were submitted to exercise stress tests, coronary angiographies, and exercise thallium 201 scintigraphies within 3-5 months of the myocardial infarction. Of the patients studied, 18 showed one-vessel disease and 33 showed multivessel disease. All vessels were classified as patent or occluded. In all patients with reversible thallium 201 defects both at distance and in the infarct zone, the QTc interval following exercise either showed a prolongation or no change from the resting electrocardiogram. In patients with only fixed perfusion defects, the QTc shortened at the end of the test. This study showed a low sensitivity and specificity for inducible ST-segment depression compared with the delayed redistribution on the postexercise thallium 201 scintigram. QTc variations at the end of exercise electrocardiograms are valuable as a noninvasive, low-cost identification of residual ischemic myocardium in patients after myocardial infarction.

[Significance exercise-induced ST elevation in patients with myocardial infarction]. / Significado do supradesnivelamento ST de esforço em doentes com enfarte do miocárdio.

In 52 patients with previous myocardial infraction, 49 men and 3 women (mean age 56 +/- 7.1 years) the significance of ST-segment elevation during the stress-test, was evaluated. Of the 52 patients 15 (29%) showed St-segment elevation and 37(71%), showed no alteration of the ST-segment. Extension of coronary disease, degree of obstruction, wall motion abnormalities and the presence of residual ischemia were evaluated by coronary angiography, technetium-99M pyrophosphate imaging and exercise TL-201 scintigraphy. From the results of the study one may conclude that, in patients with previous myocardial infraction exercise, ST-segment elevation is a consequence of sub-occlusion of the left anterior descending coronary artery with severe ventricular dysfunction either in patients with one or multiple vessel disease.

[Complete interruption of the aortic arch in adults]. / Interrupção completa do arco aórtico num adulto.

We describe a case of total interruption of the aortic arch (Steidele Complex) that survived without surgical operation and reached adulthood. The patient first presented with stroke. The diagnosis was made by cardiac catheterization. The presence of fixed pulmonary arterial hypertension excluded the possibility of surgical correction.

[Early left ventricular dysfunction in acute myocardial infarct. Evaluation using imaging methods]. / Disfunção ventricular esquerda precoce no enfarte agudo do miocárdio. Avaliação por métodos de imagem.

A patient admitted in a Coronary Care Unit with an acute anterior myocardial infarction, is presented. He had initially normal left ventricular function and, on the 11th day he had, suddenly, an acute pulmonary edema. The reason for this episode was detected through imaging techniques--echocardiography and isotopic studies, and consisted on infarct expansion with early evolution for apical aneurysm. Contrast angiography confirmed the presence of a huge aneurysm and two vessels disease. Tallium Scintigraphy showed reversible ischemia beyond necrotic areas. The patient was submitted to aneurysmectomy and received three aorto-coronary bypass. He is now doing well, in class I, NYHA. The discussion emphasizes the actual role of imaging techniques in the diagnosis of infarct expansion and early functional aneurysm. We discuss the prognostic of infarct expansion and the importance of perfusion studies on defining areas of myocardium in jeopardy, enabling a better surgical approach.