Inyecciones intracerebrales de beta amiloide: un posible modelo de la enfermedad de Alzheimer

La enfermedad del Alzheimer (EA) específico, como la causa más común de demencia en la población adulta, uno de los problemas médicos más importantes de la actualidad. Aún no existen tratamientos eficaces para esta patología, debido en parte a que su origen desconocido. La hipótesis más aceptada por la mayoría de los estudiosos de la EA, propone que el bamiloide (bA) cumpliría un rol protagónico en la génesis de la patología. El bA específico un péptido de entre 40 y 43 aminoácidos que se origina normalmente durante el procesamiento metabólico de la proteína precursora de bAmiloide (APP) y por tanto puede encontrarse en los fluidos corporales. En la EA el bA se agrega y deposita dando lugar a las placas seniles, heterogéneos depósitos extracelulares que caracterizan la lesión de la EA. Numerosos estudios han demostrado que el bA es neurotóxico y que su toxicidad depende de la formación de agregados fibrilares similares a los que componen las placas seniles. Si bien la toxicidad de bA ha sido intensamente caracterizada in vitro, los estudios in vivo realizados hasta el presente han arrojado resultados contradictorios e incompletos, siendo aún necesario un mejor y más completo análisis del efecto del bA in vivo para poder inferir conclusiones más firmes respecto de su potencial rol en la patología. El objetivo del presente trabajo es analizar el efecto de la depositación del bA in vivo. Se utilizará la técnica de microinyecciones intracerebrales para determinar: 1. El efecto de las diferentes dosis de bA en relación al grado de deposición, permanencia en el tejido y toxicidad. 2. El efecto del tiempo de sobrevida del animal luego de la aplicación del bA, respecto de la evolución del depósito de ßA y la del tejido circundante. 3. El efecto de la agregación del bA respecto de su capacidad para formar agregados estables en el tejido. Con esta serie de experimentos se espera conseguir información relevante sobre la potencial participación del bA en la patogénesis de la EA.

Efeitos da administração de beta-bloqueador na remodelação ventricular induzida pelo tabagismo em ratos

FUNDAMENTO: O papel do sistema adrenérgico na remodelação induzida pelo tabagismo é desconhecido. OBJETIVO: Investigar a influência do propranolol na remodelação induzida pela exposição à fumaça de cigarro. MÉTODOS: Ratos foram alocados em três grupos: 1) C, n=10 - animais controle; 2) F, n=10 - animais expostos à fumaça de cigarro; 3) BB, n=10 - animais expostos à fumaça de cigarro e que receberam propranolol (40 mg/kg/dia). Após dois meses, os animais foram submetidos a estudo ecocardiográfico e morfométrico. Utilizou-se análise de variância (ANOVA) de uma via (média ± desvio padrão) ou Kruskal-Wallis (mediana e intervalo interquartil). RESULTADOS: O Grupo BB apresentou menor frequência cardíaca que o Grupo F (C = 358 ± 74 btm, F = 374 ± 53 bpm, BB = 297 ± 30; P = 0,02). O Grupo F apresentou maiores diâmetros diastólicos (C = 18,6 ± 3,4 mm/kg, F = 22,8 ± 1,8 mm/kg, BB = 21,7 ± 1,8 mm/kg; P = 0,003) e sistólicos (C = 8,6 ± 2,1 mmkg, F = 11,3 ± 1,3 mm/kg, BB = 9,9 ± 1,2 mm/kg; P = 0,004) do ventrículo esquerdo (VE), ajustado ao peso corporal (PC) e tendência de menor fração de ejeção (C = 0,90 ± 0,03, F = 0,87 ± 0,03, BB =0,90 ± 0,02; P = 0,07) que o Grupo C. O Grupo BB apresentou tendência de menor relação VE/PC que o Grupo F (C = 1,94 (1,87 - 1,97), F = 2,03 (1,9-2,1) mg/g, BB = 1,89 (1,86-1,94); P = 0,09). CONCLUSÃO: A administração de propranolol atenuou algumas variáveis da remodelação ventricular induzida pela exposição à fumaça do cigarro em ratos.

Meaning refinement to improve cross-lingual information retrieval

Magdeburg, Univ., Fak. für Informatik, Diss., 2012

Elevated Blood Pressure and Obesity in Childhood: A Cross-Sectional Evaluation of 4,609 Schoolchildren

Background: The incidence of obesity in children is increasing worldwide, primarily in urbanized, high-income countries, and hypertension development is a detrimental effect of this phenomenon. Objective: In this cross-sectional study, we evaluated the prevalence of excess weight and its association with high blood pressure (BP) in schoolchildren. Methods: Here 4,609 male and female children, aged 6 to 11 years, from 24 public and private schools in Maringa, Brazil, were evaluated. Nutritional status was assessed by body mass index (BMI) according to cutoff points adjusted for sex and age. Blood pressure (BP) levels above 90th percentile for gender, age and height percentile were considered elevated. Results: The prevalence of excess weight among the schoolchildren was 24.5%; 16.9% were overweight, and 7.6% were obese. Sex and socioeconomic characteristics were not associated with elevated BP. In all age groups, systolic and diastolic BP correlated with BMI and waist and hip measurements, but not with waist-hip ratio. The prevalence of elevated BP was 11.2% in eutrophic children, 20.6% in overweight children [odds ratio (OR), 1.99; 95% confidence interval (CI), 1.61-2.45], and 39.7% in obese children (OR, 5.4; 95% CI, 4.23-6.89). Conclusion: Obese and overweight children had a higher prevalence of elevated BP than normal-weight children. Our data confirm that the growing worldwide epidemic of excess weight and elevated BP in schoolchildren may also be ongoing in Brazil.

Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients

Background:Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality.Objective:To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls.Methods:Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods.Results:Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels.Conclusion:No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls. (Arq Bras Cardiol. 2015; [online]. ahead print, PP.0-0)

Clinical Differences between Subtypes of Atrial Fibrillation and Flutter: Cross-Sectional Registry of 407 Patients

Introduction:Atrial fibrillation and atrial flutter account for one third of hospitalizations due to arrhythmias, determining great social and economic impacts. In Brazil, data on hospital care of these patients is scarce.Objective:To investigate the arrhythmia subtype of atrial fibrillation and flutter patients in the emergency setting and compare the clinical profile, thromboembolic risk and anticoagulants use.Methods:Cross-sectional retrospective study, with data collection from medical records of every patient treated for atrial fibrillation and flutter in the emergency department of Instituto de Cardiologia do Rio Grande do Sul during the first trimester of 2012.Results:We included 407 patients (356 had atrial fibrillation and 51 had flutter). Patients with paroxysmal atrial fibrillation were in average 5 years younger than those with persistent atrial fibrillation. Compared to paroxysmal atrial fibrillation patients, those with persistent atrial fibrillation and flutter had larger atrial diameter (48.6 ± 7.2 vs. 47.2 ± 6.2 vs. 42.3 ± 6.4; p < 0.01) and lower left ventricular ejection fraction (66.8 ± 11 vs. 53.9 ± 17 vs. 57.4 ± 16; p < 0.01). The prevalence of stroke and heart failure was higher in persistent atrial fibrillation and flutter patients. Those with paroxysmal atrial fibrillation and flutter had higher prevalence of CHADS2 score of zero when compared to those with persistent atrial fibrillation (27.8% vs. 18% vs. 4.9%; p < 0.01). The prevalence of anticoagulation in patients with CHA2DS2-Vasc ≤ 2 was 40%.Conclusions:The population in our registry was similar in its comorbidities and demographic profile to those of North American and European registries. Despite the high thromboembolic risk, the use of anticoagulants was low, revealing difficulties for incorporating guideline recommendations. Public health strategies should be adopted in order to improve these rates.

Optimization of radial jets mixing in cross-flow of combustion chambers using computational fluid dynamics

Cross-Flow, Radial Jets Mixing, Temperature Homogenization, Optimization, Combustion Chamber, CFD

Lexico-grammatical variation in the use of REQUEST strategies in Indian and British "letters to the editor" : a cross-cultural pragmatic study

Magdeburg, Univ., Fak. für Geistes-, Sozial- und Erziehungswiss., Diss., 2009

Modulation des kanonischen Wnt/[Beta]-Catenin-Signalweges in der Helicobacter pylori-Infektion

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2010

Mechanismen der A[beta]-induzierten neuronalen Dysfunktion

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2010

Cross-talk of protein kinase B (PKB/Akt) with the transcription factor NFAT and the Src kinase Fyn in T lymphocytes

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2010

Beeinflussung von Lokomotion und kontextueller Furcht durch die Unterbrechung des viszeralen Feedback mittels peripherer [beta]1-adrenerger Rezeptorblockade in C57BL/6JOlaHsd-Mäusen

Magdeburg, Univ., Medizin. Fakultät, Diss., 2007

Motor and cognitive development of selected Egyptian and German primary school aged children : a cross-cultural study

Magdeburg, Univ., Fak. für Humanwiss., Diss., 2013

Einfluss von Deoxynivalenol und E.coli-Lipopolysaccharid auf die Expression von ZO-1 und [beta]-Catenin im Dünndarm des Schweins

Magdeburg, Univ., Med. Fak., Diss., 2014

Cross-frequency coupling tracks motor automization and execution in the human motor system

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2014