Direct effects of colchicine on myocardial function: studies in hypertrophied and failing spontaneously hypertensive rats

The aging spontaneously hypertensive rat (SHR) is a model in which the transition from chronic stable left ventricular hypertrophy to overt heart failure can be observed. Although the mechanisms for impaired function in hypertrophied and failing cardiac muscle from the SHR have been studied, none accounts fully for the myocardial contractile abnormalities. The cardiac cytoskeleton has been implicated as a possible cause for myocardial dysfunction. If an increase in microtubules contributes to dysfunction, then myocardial microtubule disruption by colchicine should promote an improvement in cardiac performance. We studied the active and passive properties of isolated left ventricular papillary muscles from 18- to 24-month-old SHR with evidence of heart failure (SHR-F, n=6), age-matched SHR without heart failure (SHR-NF, n=6), and age-matched normotensive Wistar-Kyoto rats (WKY, n=5). Mechanical parameters were analyzed before and up to 90 minutes after the addition of colchicine (10(-5), 10(-4), and 10(-3) mol/L). In the baseline state, active tension (AT) developed by papillary muscles from the WKY group was greater than for SHR-NF and SHR-F groups (WKY 5.69+/-1.47 g/mm2 [mean+/-SD], SHR-NF 3.41+/-1.05, SHR-F 2.87+/-0.26; SHR-NF and SHR-F P<0.05 versus WKY rats). The passive stiffness was greater in SHR-F than in the WKY and SHR-NF groups (central segment exponential stiffness constant, Kcs: SHR-F 70+/-25, SHR-NF 44+/-17, WKY 41+/-13 [mean+/-SD]; SHR-F P<0.05 versus SHR-NF and WKY rats). AT did not improve after 10, 20, and 30 minutes of exposure to colchicine (10(-5), 10(-4), and 10(-3) mol/L) in any group. In the SHR-F group, AT and passive stiffness did not change after 30 to 90 minutes of colchicine exposure (10(-4) mol/L). In summary, the data in this study fail to demonstrate improvement of intrinsic muscle function in SHR with heart failure after colchicine. Thus, in the SHR there is no evidence that colchicine-induced cardiac microtubular depolymerization affects the active or passive properties of hypertrophied or failing left ventricular myocardium.

Myocardial contractility impairment with racemic bupivacaine, non-racemic bupivacaine and ropivacaine. A comparative study

To study racemic bupivacaine, non-racemic bupivacaine and ropivacaine on myocardial contractility. Isolated Wistar papillary muscles were submitted to 50 and 100 mM racemic bupivacaine (B50 and B100), non-racemic bupivacaine (NR50 and NR100) and ropivacaine (R50 and R100) intoxication. Isometric contraction data were obtained in basal condition (0.2 Hz), after increasing the frequency of stimulation to 1.0 Hz and after 5, 10 and 15 min of local anesthetic intoxication. Data were analyzed as relative changes of variation. Developed tension was higher with R100 than B100 at D1 (4.3 ± 41.1 vs -57.9 ± 48.1). Resting tension was altered with B50 (-10.6 ± 23.8 vs -4.7 ± 5.0) and R50 (-14.0 ± 20.5 vs -0.5 ± 7.1) between D1 and D3. Maximum rate of tension development was lower with B100 (-56.6 ± 38.0) than R50 (-6.3 ± 37.9) and R100 (-1.9 ± 37.2) in D1. B50, B100 and NR100 modified the maximum rate of tension decline from D1 through D2. Time to peak tension was changed with NR50 between D1 and D2. Racemic bupivacaine depressed myocardial contractile force more than non-racemic bupivacaine and ropivacaine. Non-racemic and racemic bupivacaine caused myocardial relaxation impairment more than ropivacaine.

Rutin administration attenuates myocardial dysfunction in diabetic rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Low intensity physical exercise attenuates cardiac remodeling and myocardial oxidative stress and dysfunction in diabetic rats

We evaluated the effects of a low intensity aerobic exercise protocol on cardiac remodeling and myocardial function in diabetic rats. Wistar rats were assigned into four groups: sedentary control (C-Sed), exercised control (C-Ex), sedentary diabetes (DM-Sed), and exercised diabetes (DM-Ex). Diabetes was induced by intraperitoneal injection of streptozotocin. Rats exercised for 9 weeks in treadmill at 11 m/min, 18 min/day. Myocardial function was evaluated in left ventricular (LV) papillary muscles and oxidative stress in LV tissue. Statistical analysis was given by ANOVA or Kruskal-Wallis. Echocardiogram showed diabetic groups with higher LV diastolic diameter-to-body weight ratio and lower posterior wall shortening velocity than controls. Left atrium diameter was lower in DM-Ex than DM-Sed (C-Sed: 5.73 ± 0.49; C-Ex: 5.67 ± 0.53; DM-Sed: 6.41 ± 0.54; DM-Ex: 5.81 ± 0.50 mm; P < 0.05 DM-Sed vs C-Sed and DM-Ex). Papillary muscle function was depressed in DM-Sed compared to C-Sed. Exercise attenuated this change in DM-Ex. Lipid hydroperoxide concentration was higher in DM-Sed than C-Sed and DM-Ex. Catalase and superoxide dismutase activities were lower in diabetics than controls and higher in DM-Ex than DM-Sed. Glutathione peroxidase activity was lower in DM-Sed than C-Sed and DM-Ex. Conclusion. Low intensity exercise attenuates left atrium dilation and myocardial oxidative stress and dysfunction in type 1 diabetic rats.

Possible underestimation by sports medicine of the effects of early physical exercise practice on the prevention of diseases in adulthood

In modern society, combatting cardiovascular and metabolic diseases has been highlighted as an urgent global challenge. In recent decades, the scientific literature has identified that behavioral variables (e.g. smoking, unhealthy diet and physical inactivity) are related to the development of these outcomes and, therefore, preventive actions should focus on the promotion of physical exercise practice and a healthy diet, as well as combatting the smoking habit from an early age. The promotion of physical exercise in the general population has been suggested as a relevant goal by significant health organizations around the world. On the other hand, recent literature has indicated that physical exercise performed in early life prevents the development of diabetes mellitus, dyslipidemia and arterial hypertension during adulthood, although this protective effect seems to be independent of the physical activity performed during adulthood. Apparently, the interaction between physical exercise and human growth in early life constitutes an issue which is not completely understood by sports medicine. The aim of the present review was therefore to discuss recent evidence on the effects of physical exercise performed during childhood and adolescence on cardiovascular and metabolic outcomes in adulthood.

Speech-language therapy for treatment of dysphagia and dysphonia in systemic granulomatous diseases: granulomatous diseases: dysphagia and dysphonia treatments

The granulomatous lesions are frequently founded in infectious diseases and can involve the larynx and pharynx and can cause varying degrees of dysphonia and dysphagia. There is still no systematic review that analyzes effectiveness of speech therapy in systemic granulomatous diseases. Research strategy: A systematic review was performed according to Cochrane guideline considering the inclusion of RCTs and quasi-RCTs about the effectiveness of speech-language therapy to treat dysphagia and dysphonia symptoms in systemic granulomatous diseases of the larynx and pharynx. Selection criteria: The outcome planned to be measured in this review were: swallowing impairment, frequency of chest infections and voice and swallowing symptoms. Data analysis: We identified 1,140 citations from all electronic databases. After an initial shift we only selected 9 titles to be retrieved in full-text. After full reading, there was no RCT found in this review and therefore, we only described the existing 2 case series studies. Results: There were no randomized controlled trials found in the literature. Therefore, two studies were selected to be included only for narratively analysis as they were case series. Conclusion: There is no evidence from high quality studies about the effectiveness of speech-language therapy in patients with granulomatous diseases of the larynx and pharynx. The investigators could rely in the outcomes suggested in this review to design their own clinical trials.

Serum myeloperoxidase level is Increased in heavy smokers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chitosan/Carbomer-based tablets containing Metronidazole for potential treatment of periodontal diseases

Mucoadhesive tablets with different mixtures of chitosan and carbomer homopolymer type B were prepared in order to obtain new formulations containing metronidazole for periodontal disease treatment. All tablets were characterized by swelling and erosion studies, ex vivo mucoadhesion force and in vitro drug release. The drug released mechanism was described by Korsmeyer-Peppas and Weibull models. Tablets containing increased amounts of chitosan presented higher swelling ability and the drug release was prolonged in the simulated saliva fluid. The mechanisms for the drug release from tablets were complex, including diffusion, swelling and erosion simultaneously. This kind of delivery system is suitable for formulating metronidazole mucoadhesive systems, representing a good alternative for the local treatment of periodontal diseases.

Preliminary diagnosis of ophtalmological diseases through machine learning techniques

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Metalloproteinases-2 and -9 predict left ventricular remodeling after myocardial infarction

Background: The role of serum metalloproteinases (MMP) after myocardial infarction (MI) is unknown. Objective: The aim of this study was to evaluate the role of serum MMP-2 and -9 as predictors of ventricular remodeling six months after anterior MI. Methods: We prospectively enrolled patients after their first anterior MI. MMP activity was assayed 12 to 72 hours after the MI. An echocardiogram was performed during the hospitalization and six months later. Results: We included 29 patients; 62% exhibited ventricular remodeling. The patients who exhibited remodeling had higher infarct size based on creatine phosphokinase (CPK) peak values (p = 0.037), higher prevalence of in-hospital congestive heart failure (p = 0.004), and decreased ejection fraction (EF) (p = 0.007). The patients with ventricular remodeling had significantly lower serum levels of inactive MMP-9 (p = 0.007) and significantly higher levels of the active form of MMP-2 (p = 0.011). In a multivariate logistic regression model, adjusted by age, CPK peak, EF and prevalence of heart failure, MMP-2 and -9 serum levels remained associated with remodeling (p = 0.033 and 0.044, respectively). Conclusion: Higher serum levels of inactive MMP-9 were associated with the preservation of left ventricular volumes, and higher serum levels of the active form of MMP-2 were a predictor of remodeling 6 months after MI. (Arq Bras Cardiol. 2013;100(4):315-321).

Eletrocardiograma em cães: revisão

The electrocardiogram (ECG) is an important tool used in the diagnosis of cardiac arrhythmias, since it gives the graphic representation of depolarization and repolarization processes of the cardiac muscle. This study allows recording the electrical activity of myocardial cells and the underlying differences in electric potential: the magnitude of this difference is measured in millivolts (mV), and its duration is measured in seconds. The ECG is indicated when an irregular rhythm is detected during physical examination, such as bradycardias, tachycardias or arrhythmias that are not secondary to breathing, in animals with a history of syncope or weakness, for monitoring the effectiveness of antiarrhythmic therapy, in cases of putative pleural or pericardial effusion, and also in systemic diseases that lead to arrhythmia. For a reliable assessment, the ECG must be evaluated in conjunction with findings from the physical examination and clinical signs of each patient.

Emergence of Diseases From Wildlife Reservoirs

Interest in the epidemiology of emerging diseases of humans and livestock as they relate to wildlife has increased greatly over the past several decades. Many factors, most anthropogenic, have facilitated the emergence of diseases from wildlife. Some livestock diseases have ‘‘spilled over’’ to wildlife and then ‘‘spilled back’’ to livestock. When a population is exposed to an infectious agent, depending on an interaction of factors involving the host, agent, and environment, the population may be resistant to infection or may become a dead-end host, a spillover host, or a maintenance host. Each exposure is unique; the same species of host and agent may respond differently in different situations. Management actions that affect the environment and behavior of a potential host animal may allow the emergence of a new or as yet undetected disease. There are many barriers in preventing, detecting, monitoring and managing wildlife diseases. These may include political and legal hurdles, lack of knowledge about many diseases of wildlife, the absence of basic data on wildlife populations, difficulties with surveillance, and logistical constraints. Increasing interaction between wildlife and humans or domestic animals may lead to disease emergence and require innovative methods and strategies for disease surveillance and management in wildlife.

Zoonotic Diseases in the Changing Arctic

Compatible with the biotic uniformity of northern regions, the occurrence of certain organisms which cause zoonotic diseases is general throughout the Arctic. In the past, most frequently affected by such diseases have been aboriginal peoples whose way of life involved encroachment upon naturally occurring parasite-host assemblages. Now, as changes take place in socioeconomic conditions in the Arctic, the importance of zoonotic diseases as a cause of morbidity may lessen among such peoples, but on the other hand, more nonaborigines may be affected. Although my remarks relate mainly to Alaska, again the biotic uniformity of the North seems to have its effect even with regard to man's activity, for similar changes are occurring throughout the arctic zone. Thus far, the natural environment has not been extensively disrupted at higher latitudes, and the arctic regions remain important for basic research in the natural history of zoonotic diseases. Because of the biotic peculiarities of these regions, conditions there especially favor the investigation of parasite-host relationships and the transmission of disease among the inhabitants. Significant benefit to the human population, in the temperate zone as well, can be expected to accrue from future studies in an undisturbed arctic wilderness.

Parasites and Diseases of Mullets (Mugilidae)

The following treatment of parasites, diseases and conditions affecting mullet hopefully serves several functions. It acquaints someone involved in rearing mullets with problems he can face and topics he should investigate. We cannot go into extensive illustrative detail on every species or group, but do provide a listing of most parasites reported or known from mullet and some pertinent general information on them. Because of these enumerations, the paper should also act as a review for anyone interested in mullet parasites or the use of such parasites as indicators about a mullet's diet and migratory behavior. Unfortunately, limited space prohibits us from presenting all the references used. The paper also deals with the public health aspects of eating or selling mullet, whether the product is to be raw, cooked, salted or smoked.

Emerging Marine Diseases: Climate Links and Anthropogenic Factors

Mass mortalities due to disease outbreaks have recently affected major taxa in the oceans. For closely monitored groups like corals and marine mammals, reports of the frequency of epidemics and the number of new diseases have increased recently. A dramatic global increase in the severity of coral bleaching in 1997-98 is coincident with high El Niño temperatures. Such climate-mediated, physiological stresses may compromise host resistance and increase frequency of opportunistic diseases. Where documented, new diseases typically have emerged through host or range shifts of known pathogens. Both climate and human activities may have also accelerated global transport of species, bringing together pathogens and previously unexposed host populations.