Respiratory muscle training decreases diaphragm DNA damage in rats with heart failure.

Respiratory muscle training (RMT) promotes beneficial effects on respiratory mechanics, heart and lung morphological changes, and hemodynamic variables in rats with heart failure (HF). However, the relation between RMT effects and diaphragm oxidative stress remains unclear. Therefore, the aim of this study was to evaluate the RMT effects on diaphragm DNA damage in HF rats. Wistar rats were allocated into 4 groups: sedentary sham (Sed-Sham, n = 8), trained sham (RMT-Sham, n = 8), sedentary HF (Sed-HF, n = 8), and trained HF (RMT-HF, n = 8). The animals underwent a RMT protocol (30 min/day, 5 days/week for 6 weeks), whereas sedentary animals did not exercise. Groups were compared by a two-way ANOVA and Tukey's post hoc tests. In rats with HF, RMT promoted reduction in pulmonary congestion (p < 0.0001) and left ventricular end diastolic pressure (p < 0.0001). Moreover, RMT produced a decrease in the diaphragm DNA damage in HF rats. This was demonstrated through the reduction in the percentage of tail DNA (p < 0.0001), tail moment (p < 0.01), and Olive tail moment (p < 0.001). These findings showed that a 6-week RMT protocol in rats with HF promoted an improvement in hemodynamic function and reduces diaphragm DNA damage.

Nuclear abnormalities in cells from nasal epithelium: a promising assay to evaluate DNA damage related to air pollution in infants / Anormalidades nucleares em células do epitélio nasal: uma técnica promissora para avaliar dano no DNA relacionado à poluição atmosférica em neonatos

OBJECTIVES: This study intends to provide a quick, easy, and inexpensive way to assess nuclear abnormalities such as micronuclei and bud frequencies; binucleated, karyorrhectic, karyolytic, pycnotic, and condensed chromatin cells in nasal scrapings of infants, which are particularly important for conducting genotoxic studies related to the inhaled atmosphere in pediatric populations. METHODS: Nasal swab samples were collected from 40 infants under 12 months of age using a small cytobrush. 2,000 cells from each infant sample were analyzed and classified according to the frequency of nuclear abnormalities. RESULTS: Rates of nuclear abnormalities found agree with values reported in other studies of neonates and children. This study found 0.13% of cells with micronuclei; 1.20% karyorrhexis; 0.03% pyknosis; 10.85% karyolysis; 1.11% condensed chromatin; 0.54 binucleated cells; and 0.02% nuclear bud. Differences were not observed between genders or environmental passive smoking, nor was any age correlation found. CONCLUSION: The assay proposed here is suitable for assessing the frequency of nuclear abnormalities from nasal cells in infants. .

OBJETIVOS: Este estudo pretendeu fornecer uma forma rápida, fácil e barata de avaliar anormalidades nucleares, como frequências de micronúcleos e gêmea, células binucleadas, cariorréticas, cariolíticas, picnóticas e com cromatina condensada, em esfregados nasais de neonatos, o que é particularmente importante para a realização de estudos genotóxicos relacionados ao ar inalado nas populações pediátricas. MÉTODOS: Foram coletadas amostras de esfregaço nasal de 40 neonatos com menos de 12 meses de idade, utilizando uma pequena escova citológica. Foram analisadas 2.000 células da amostra de cada neonato e classificadas de acordo com a frequência de anormalidades nucleares. RESULTADOS: As taxas de anormalidades nucleares encontradas neste estudo são compatíveis com os valores relatados em outros estudos de neonatos e crianças. Encontramos 0,13% de células com micronúcleos, 1,20% com cariorrexe, 0,03% com picnose, 10,85% com cariólise, 1,11% com cromatina condensada, 0,54 com células binucleadas e 0,02% com células nucleares gêmeas. Não observamos diferenças entre os gêneros, tabagismo passivo e nenhuma correlação entre idades. CONCLUSÃO: O ensaio proposto neste estudo é adequado para avaliar a frequência de anormalidades nucleares de células nasais em neonatos. .

Nuclear abnormalities in cells from nasal epithelium: a promising assay to evaluate DNA damage related to air pollution in infants.

OBJECTIVES: This study intends to provide a quick, easy, and inexpensive way to assess nuclear abnormalities such as micronuclei and bud frequencies; binucleated, karyorrhectic, karyolytic, pycnotic, and condensed chromatin cells in nasal scrapings of infants, which are particularly important for conducting genotoxic studies related to the inhaled atmosphere in pediatric populations. METHODS: Nasal swab samples were collected from 40 infants under 12 months of age using a small cytobrush. 2,000 cells from each infant sample were analyzed and classified according to the frequency of nuclear abnormalities. RESULTS: Rates of nuclear abnormalities found agree with values reported in other studies of neonates and children. This study found 0.13% of cells with micronuclei; 1.20% karyorrhexis; 0.03% pyknosis; 10.85% karyolysis; 1.11% condensed chromatin; 0.54 binucleated cells; and 0.02% nuclear bud. Differences were not observed between genders or environmental passive smoking, nor was any age correlation found. CONCLUSION: The assay proposed here is suitable for assessing the frequency of nuclear abnormalities from nasal cells in infants.

Effects of the chronic use of finasteride and doxazosin mesylate on the histomorphometric characteristics of the prostate: experimental study in rats.

OBJECTIVE: The objective of the present study is to evaluate the histomorphometric characteristics of the prostate of rats submitted to chronic (long-time) treatment with doxazosin mesylate, finasteride and both substances combined. MATERIALS AND METHODS: Four groups of eight rats each were selected for this study and treated with saline solution (control), doxazosin mesylate, finasteride and combination of the drugs, during 10 months. After this time, the prostate was removed, weighed and sent for histological analysis. Prostate sections were stained with Masson trichrome. With an image analyzer, the percentage of smooth muscle, collagen, epithelium, acinar lumen and interstitial space was measured. Also, the minimum, medium and maximum epithelial thickness, number of acini per field, mean acinar area and the presence of papillary projections were evaluated. RESULTS: The mean prostate weight of rats treated with finasteride and combined treatment was lower when compared to the control group (P < 0.05). Prostate from rats treated with finasteride alone had a lower percentage of the epithelial component and a smaller minimum epithelial thickness than the control group (P < 0.05). The number of acini per field in the combined groups was higher than that observed in all other groups (P < 0.05). Also, rats of the finasteride and combined groups presented a reduced number of papillary projections when compared to the other groups (P < 0.05). CONCLUSION: Our study clearly showed the effects of finasteride on prostate tissue, and from a histomorphometric perspective, it was not able to detect any advantage of the combined treatment over the use of finasteride alone.

PM-induced cardiac oxidative stress and dysfunction are mediated by autonomic stimulation.

Epidemiological studies show that increases in particulate air pollution (PM) are associated with increases in cardiopulmonary morbidity and mortality. However, the mechanism(s) underlying the cardiac effects of PM remain unknown. We used pharmacological strategies to determine whether oxidants are implicated in PM-dependent cardiac dysfunction and whether PM-induced increase in autonomic stimulation on the heart mediates cardiac oxidative stress and toxicity. Adult Sprague-Dawley rats were exposed to either intratracheal instillation of urban air particles (UAP 750 microg) or to inhalation of concentrated ambient particles (CAPs mass concentration 700+/-180 microg/m3) for 5 h. Oxidative stress and cardiac function were evaluated 30 min after UAP instillation or immediately after exposure to CAPs. Instillation of UAP led to significant increases in heart oxidants measured as organ chemiluminescence (UAP: 38+/-5 cps/cm2, sham: 10+/-1 cps/cm2) or thiobarbituric acid reactive substances (TBARS, UAP: 76+/-10, Sham 30+/-6 pmol/mg protein). Heart rate increased immediately after exposure (UAP: 390+/-20 bpm, sham: 350+/-10 bpm) and returned to basal levels over the next 30 min. Heart rate variability (SDNN) was unchanged immediately after exposure, but significantly increased during the recovery phase (UAP: 3.4+/-0.2, Sham: 2.4+/-0.3). To determine the role of ROS in the development of cardiac malfunction, rats were treated with 50 mg/kg N-acetylcysteine (NAC) 1 h prior to UAP instillation or CAPs inhalation. NAC prevented changes in heart rate and SDNN in UAP-exposed rats (340+/-8 and 2.9+/-0.3, respectively). To investigate the role of the autonomic nervous system in PM-induced oxidative stress, rats were given 5 mg/kg atenolol (beta-1 receptor antagonist), 0.30 mg/kg glycopyrrolate (muscarinic receptor antagonist) or saline immediately before exposure to CAPs aerosols. Both atenolol and glycopyrrolate effectively prevented CAPs-induced cardiac oxidative stress (CL(ATEN): 11+/-1 cps/cm2, CL(GLYCO): 10+/-1 cps/cm2, TBARS(ATEN): 40+/-6 pmol/mg protein, TBARS(GLYCO): 38+/-6 pmol/mg protein). These data indicate that PM exposure increases cardiac oxidants via autonomic signals and the resulting oxidative stress is associated with significant functional alterations in the heart.

Amnoglicosideos: uma revisao / Aminoglycosides: a review

Os autores fazem uma revisao a respeito dos antibioticos aminoglicosideos enfatizando os mecanismos envolvidos nas reacoes adversas produzidas por estas drogas, assim como as possiveis interacoes com outros medicamentos. Referem procedimentos para o controle dos principais efeitos adversos, evidenciando aqueles com comprometimento da funcao renal.