Minimum inhibitory concentrations of amphotericin B, azoles and caspofungin against Candida species are reduced by farnesol.

The objective of this study was to evaluate the antifungal activity of farnesol and its interaction with traditional antifungals against drug-resistant strains of Candida species. To do so, we studied the minimum in vitro inhibitory concentration (MIC) of amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), caspofungin (CAS) and farnesol against 45 isolates of Candida spp., i.e., 24 C. albicans, 16 C. parapsilosis and 5 C. tropicalis through the use of the broth microdilution method. Then, the isolates were tested with the combination of farnesol plus drugs to which they were previously found to be resistant. Additionally, the strains were pre-incubated at sub-inhibitory farnesol concentrations and their antifungal susceptibilities were re-evaluated. We found the MIC values for farnesol varied from 4.68-150 µM for Candida spp., with 19 isolates having a MIC > 1 mg/l, 18 a MIC ≥ 64 mg/l, 35 having a MIC ≥ 1 mg/l and 6 isolates a MIC ≥ 2 mg/l or were resistant to AMB, FLC, ITC and CAS, respectively. Significant MIC reductions were observed when farnesol and antifungal drugs were combined (P < 0.05) and when Candida strains were incubated with farnesol (P < 0.05). We conclude that the in vitro effects of farnesol improved the activity of traditional antifungals to which the Candida spp. isolates were resistant. These results support further investigation of the role of farnesol in the balance of the sterol biosynthetic pathway and how it interferes with cell viability.

Yeasts from Macrobrachium amazonicum: a focus on antifungal susceptibility and virulence factors of Candida spp.

In the present study, it was sought to compare yeast microbiota of wild and captive Macrobrachium amazonicum and evaluate the antifungal susceptibility and production of virulence factors by the recovered isolates of Candida spp. Additionally, cultivation water was monitored for the presence of fungi. Overall, 26 yeast isolates belonging to three genera and seven species were obtained, out of which 24 were Candida spp., with Candida famata as the most prevalent species for both wild and captive prawns. From cultivation water, 28 isolates of filamentous fungi were obtained, with Penicillium spp., Cladosporium spp. and Aspergillus spp. as the most frequent genera. Eight out of 24 Candida spp. isolates were resistant to azole derivatives, out of which four were recovered from wild-harvested prawns. As for production of virulence factors, three (12.5%) and eight (33.3%) isolates presented phospholipase and protease activity, respectively. This is the first comparative study between wild and captive prawns and the first report on yeast microbiota of M. amazonicum. The most relevant finding was the high percentage of resistant Candida spp., including from wild individuals, which suggests the occurrence of an environmental imbalance in the area where these prawns were captured.

Echocardiographic predictors of functional capacity in endomyocardial fibrosis patients.

AIMS: Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy manifested mainly by diastolic heart failure. It is recognized that diastole is an important determinant of exercise capacity. The purpose of this study was to determine whether resting echocardiographic parameters might predict oxygen consumption (VO(2p)) by ergoespirometry and the prognostic role of functional capacity in EMF patients. METHODS AND RESULTS: A total of 32 patients with biventricular EMF (29 women, 55.3 +/- 11.4 years) were studied by echocardiography and ergoespirometry. The relationship between the echocardiographic indexes and the percentage of predicted VO(2p) (%VO(2p)) was investigated by the 'stepwise' linear regression analysis. The median VO(2p) was 11 +/- 3 mL/kg/min and the %VO(2p) was 53 +/- 9%. There was a correlation of %VO(2p) with an average of A' at four sites of the mitral annulus (A' peak, r = 0.471, P = 0.023), E'/A' of the inferior mitral annulus (r = -0.433, P = 0.044), and myocardial performance index (r = -0.352, P = 0.048). On multiple regression analysis, only A' peak was an independent predictor of %VO(2p) (%VO(2p)= 26.34 + 332.44 x A' peak). EMF patients with %VO(2p)< 53% had an increased mortality rate with a relative risk of 8.47. CONCLUSION: In EMF patients, diastolic function plays an important role in determining the limitations to exercise and %VO(2p) has a prognostic value.

Subculture on potato dextrose agar as a complement to the broth microdilution assay for Malassezia pachydermatis.

The main aim of this study was to verify the efficacy of subculture on potato dextrose agar (PDA) as a complement to the in vitro susceptibility test for Malassezia pachydermatis strains by a broth microdilution method, as well as to determine the MIC and MFC of azole derivatives, amphotericin B and caspofungin. The microdilution assay was performed in 96-well plates using a modified RPMI 1640 medium. The M. pachydermatis strains were resistant to caspofungin. All strains (n=50) had shown MIC values of <0.03, <0.03, 2.0, 4.0 and 4.0 microg/ml for itraconazole, ketoconazole, voriconazole, fluconazole and amphotericin B, respectively. Thus, the subculture on PDA improved the analysis of the in vitro antifungal susceptibility of M. pachydermatis.

Effect of enalapril on left ventricular diameters and exercise capacity in asymptomatic or mildly symptomatic patients with regurgitation secondary to mitral valve prolapse or rheumatic heart disease.

The effects of 12 months of therapy were evaluated in 47 mildly symptomatic patients with moderate to severe mitral valve regurgitation; 26 patients received enalapril and 21 received a placebo. Enalapril was associated with a significant reduction in left ventricular diameter and mitral regurgitation volume, with no evidence of change in systolic function indexes. However, enalapril did not hinder progressive aerobic impairment to effort.

Periodic breathing during incremental exercise predicts mortality in patients with chronic heart failure evaluated for cardiac transplantation.

OBJECTIVES: We hypothesized that exercise-related periodic breathing (EPB) would be associated with poor prognosis in advanced chronic heart failure (CHF). BACKGROUND: Patients with CHF might present instability of the ventilatory control system characterized by cyclic waxing and waning of tidal volume (periodic breathing [PB]). This condition is associated with several deleterious circulatory and neuro-endocrine responses; in fact, PB in awake and asleep patients has been identified as an independent risk factor for cardiac death. During exercise, however, the prognostic value of PB is still unknown in CHF patients awaiting heart transplantation. METHODS: Eighty-four patients with established CHF (65 male, 19 female) were submitted to clinical evaluation, echocardiogram, ventricular scintigraphy, determination of resting serum norepinephrine levels, and an incremental cardiopulmonary exercise test on cycle ergometer. Patients were followed for up to 49.7 months (median = 15.3), and 26 patients (30.9%) died during this period. RESULTS: Twenty-five of 84 patients presented EPB (29.7%). The following variables were related to mortality according to Kaplan-Meier and univariate Cox regression analysis: EPB (p = 0.004), New York Heart Association class (p = 0.04), serum norepinephrine (p = 0.06), peak oxygen uptake (ml.min(-1).kg(-1) and % predicted; p = 0.085 and p = 0.10, respectively), slope of the ratio of change in minute ventilation to change in carbon dioxide output during exercise (p = 0.10), and scintigraphic left ventricular ejection fraction (p = 0.10). Cox multivariate analysis identified EPB as the only independent variable for cardiac death prediction (p = 0.007). Therefore, EPB alone was associated with a 2.97-fold increase in risk of death in this population (95% confidence interval = 1.34 to 6.54). CONCLUSIONS: Exercise-related periodic breathing independently predicts cardiac mortality in CHF patients considered for heart transplantation.

Teste de esforço cardiopulmonar na avaliaçäo de doenças musculares / Cardiopulmonary exercise testing for evaluation of muscle diseases

Objetivo: Analisar o teste de esforço cardiopulmonar (TECP) no diagnóstico de miopatias. Métodos: 27 pacientes com miopatia realizaram TECP (protocolo de bicicleta em rampa, máximo, interrompido por sintoma). Resultados: Pacientes distróficos e pacientes com mitocondriopatias mostraram diferenças significativas em relaçao aos controles para as variáveis potência do trabalho desenvolvido (watt) e pico do consumo de oxigênio (VO2máx). Pacientes com mitocondriopatias mostraram diminuiçao significativa do limiar anaeróbio em relaçao aos controles, além de elevaçao dos valores do quociente respiratório (QR) do pico do exercício em relaçao aos demais grupos. Conclusoes: TECP pode ser útil na avaliaçao evolutiva do grau de limitaçao física dos pacientes com miopatia. As variáveis potência do trabalho desenvolvido, VO2 máx, limiar anaeróbio e QR do pico do exercício podem sugerir o diagnóstico de miopatia e seus subtipos, excluindo quadros psicológicos.

Efeitos da digoxina e do verapamil sobre a capacidade física em idosos portadores de fibrilaçäo atrial crônica isolada / Effects of digoxin and verapa mil on physical capacity in the elderly with isolated chronic atrial fibrillation

Considerando-se o usual emprego de fármacos depressores do cronotropismo em portadores de fibrilaçäo atrial crônica (FAC), objetivou-se avaliar os reais efeitos da digoxina e do verapamil sobre a capacidade física de idosis portadores desta arritmia, isolada. Foram selecionados 9 pacientes (6 homens), com idade média de 76 ñ 5 anos, que foram submetidos à avaliaçäo cardiopulmonar durante esforço, a intervalos de 10 días, na seqüência: sem droga, sob uso de digoxina 0,25 mg/dia e com verapamil 240mg/dia. Verificou-se que somente o verapamil reduziu a freqüência cardíaca máxima, em relaçäo ao estado sem droga. Porém, assim como a digoxina, näo modificou significativamente o consumo máximo de oxigênio. É discutível, portanto, o emprego destes fármacos nos casos de FAC sem disfunçäo ventricular