Influence of Insulin-like Growth Factor I (IGF-I) on the survival and the in vitro development of caprine preantral follicles / Influência do Fator de Crescimento Semelhante à Insulina-I (IGF-I) sobre a sobrevivência e o desenvolvimento in vitro de folículos pré-antrais caprinos

The aim of this study was to investigate the effects of the insulin-like growth factor -I (IGF-I) on survival, activation (transition from primordial to primary follicles) and growth of caprine preantral follicles cultured in vitro. Fragments of ovarian cortex were cultured for one and seven days in the absence or presence of IGF-I (0, 50 and 100ng/ml). The non-cultured and cultured tissues were processed and analyzed by histology and transmission electron microscopy. The culture for one day in a medium with 100ng/ml of IGF-I showed 86.7% of morphologically normal follicles. These results were similar (P>0.05) to the percentage of normal follicles found in the control (96.7%). It was also found that this medium increased the percentage of follicular activation (developing follicles) with one day of culture. The oocyte and follicular diameters remained similar to the control by culturing for one day in a medium containing 100ng/ml of IGF-I. The ultrastructural analysis did not confirm the integrity of the follicular fragments in a medium containing IGF-I (100ng/ml) after one and seven days of culture. In conclusion, this study demonstrated that the addition of 100 ng/ml of IGF-I in the culture medium enables the development of preantral follicles of goats with one day of culture. However, it is not sufficient to maintain the follicular integrity and the follicular survival rate after seven days of culture.

O objetivo do presente estudo foi investigar os efeitos do fator de crescimento semelhante a insulina-I (IGF-I) na sobrevivência, ativação (transição de folículos primordiais para primários) e crescimento de folículos pré-antrais caprinos cultivados in vitro. Fragmentos de córtex ovariano foram cultivados por um e sete dias na ausência ou presença de IGF-I (0, 50 e 100ng/mL). Os tecidos não cultivados e cultivados foram processados e analisados por histologia e microscopia eletrônica de transmissão. O cultivo por um dia em meio com 100ng/mL de IGF-I apresentou 86,7% de folículos morfologicamente normais. Estes resultados foram semelhantes (P>0,05) ao percentual de folículos normais encontrados no controle (96,7%). Verificou-se ainda que este meio aumentou o percentual de ativação folicular (folículos em desenvolvimento) com um dia de cultivo. Os diâmetros ovocitário e folicular mantiveram-se semelhantes ao controle ao cultivar por um dia em meio contendo 100ng/mL de IGF-I. As análises ultraestruturais não confirmaram a integridade folicular dos fragmentos em meio contendo IGF-I (100 ng/mL) após um e sete dias de cultivo. Em conclusão, esse estudo demonstrou que a adição de 100 ng/mL de IGF-I no meio de cultivo ativa o desenvolvimento de folículos pré-antrais de caprinos com um dia de cultivo. Entretanto, não é suficiente para manter a integridade folicular e a taxa de sobrevivência folicular após sete dias de cultivo.

The effect of montelukast on exhaled nitric oxide of alveolar and bronchial origin in inhaled corticosteroid-treated asthma.

BACKGROUND: Inhaled corticosteroid therapy suppresses nitric oxide levels (NO) of airway origin but not necessarily NO of alveolar or small airway origin. Systemic therapy with an oral anti-leukotriene agent may suppress NO production in distal airways and alveoli not reached by inhaled therapy. METHODS: Adult patients with mild asthma were treated for 3 weeks with inhaled fluticasone 250 microg twice daily then with inhaled fluticasone plus oral montelukast 10 mg daily for 3 additional weeks. We monitored exhaled NO (eNO), spirometry, lung volumes, and asthma symptoms scores at baseline and at the end of each treatment period. In a subset of patients, we continued with montelukast monotherapy and repeated these measurements. RESULTS: In the 18 patients studied, pulmonary function parameters and asthma symptom scores were not altered significantly from baseline by any therapy. The total eNO at baseline was 55+/-35.3 ppb, dropping to 28.1+/-15.3 ppb (p=0.005) after 3 weeks of fluticasone and to 23.5+/-14 ppb (p=0.001 vs. baseline) after the addition of montelukast. The trend towards reduced total eNO with the combination therapy vs. monotherapy was not statistically significant. Alveolar eNO dropped from 4.2+/-2.4 at baseline to 3.0+/-1.5 (p=0.1) after fluticasone and then to 2.2+/-0.9 (p=0.08 vs. baseline) after fluticasone plus montelukast, increasing then to 3.8+/-1.8 after montelukast alone (p=0.6 vs. baseline). CONCLUSIONS: Leukotriene receptor antagonists administered systemically might decrease small airway/alveolar sites of inflammation when combined to inhaled corticosteroid therapy.

Tiotropium and simplified detection of dynamic hyperinflation.

STUDY OBJECTIVE: To detect dynamic hyperinflation (DH) by evaluating reduction in inspiratory capacity (IC) during metronome-paced hyperventilation (MPH) in patients with moderate-to-severe COPD, studied before and after treatment with tiotropium. METHODS: IC and FEV(1) were measured before and immediately after MPH at two times resting the respiratory rate for 20 s in 60 COPD patients (28 men; mean age, 66 +/- 10 years [+/- SD]) before and after 30 days of treatment with tiotropium bromide, 18 mug. Patients were encouraged to maintain a constant tidal volume during MPH. RESULTS: At baseline, mean FEV(1) was 1.5 +/- 0.1 L (+/- SE) [57 +/- 1.6% of predicted], mean FVC was 2.6 +/- 0.1L (77 +/- 1.8% of predicted), and mean FEV(1)/FVC was 56 +/- 1%. After 180 mug of aerosolized albuterol sulfate, mean FEV(1) was 1.7 +/- 0.1 L (63 +/- 1.5% of predicted) [p < 0.001] and mean FEV(1)/FVC was 58 +/- 1%. Compared to baseline, after 30 days and 1.5 h after tiotropium there was an increase in IC of 0.18 +/- 0.04L (p < 0.0001); FEV(1) of 0.13 +/- 0.03 L (5.6 +/- 0.8% of predicted; p = 0.0002); FVC of 0.22 +/- 0.05 L (6.5 +/- 1.3% of predicted; p < 0.001); and decrease in end-expiratory lung volume (EELV)/total lung capacity (TLC) of - 3.1 +/- 0.6% (p = 0.0001); a decrease in end-inspiratory lung volume (EILV)/TLC of - 2.9 +/- 1.3% (p = 0.03); and no change in TLC (- 0.06 +/- 0.05 L). Results following MPH-induced DH at baseline and after 30 days of tiotropium were similar, with decreases in IC (- 0.35 +/- 0.03 L; p < 0.001); FEV(1) (- 0.05 +/- 0.04 L; p = 0.2); and FVC (- 0.22 +/- 0.03 L; p < 0.0001); no change in TLC; and increases in EELV/TLC (11.8 +/- 1.0% of predicted; p < 0.0001) and EILV/TLC (4.0 +/- 1.3% of predicted, p < 0.003). CONCLUSION: In patients with moderate-to-severe COPD, tiotropium did not reduce MPH-induced DH and reduction in IC, compared to baseline. However, because tiotropium induced bronchodilation and increased baseline IC, lower operational lung volumes may blunt the effect of MPH-induced DH. The noninvasive simplicity of MPH-induced DH provides a clinically useful screening surrogate to monitor changes in IC following treatment with tiotropium.