Wavelet transform for analysis of heart rate variability preceding ventricular arrhythmias in patients with ischemic heart disease

INTRODUCTION: Studies evaluating changes in HRV preceding the onset of ventricular arrhythmias using conventional techniques have shown inconsistent results. Time-frequency analysis of HRV is traditionally performed using short-term Fourier transform (STFT). Wavelet transform (WT) may however be better suited for analyzing non-stationary signals such as heart rate recordings. METHODS AND RESULTS: We studied patients with a history of myocardial infarction implanted with a defibrillator with an extended memory. The RR intervals during the 51 min preceding ventricular events requiring electrical therapy were retrieved, and HRV studied by WT and STFT. 111 episodes of ventricular arrhythmia were retrieved from 41 patients (38 males, age 64 +/- 8 years). Heart rate increased significantly before arrhythmia. There was no significant variation in low frequency / high frequency components (LF/HF) observed for the group as a whole, probably due to a great degree of heterogeneity amongst individuals. A subset of 30 patients also had heart rate recordings performed during normal ICD follow-up. WT did not show any difference in HRV before arrhythmia onset and during control conditions. CONCLUSION: Variations in HRV before onset of ventricular arrhythmias were not apparent in this large dataset, despite use of optimal tools for studying time-frequency analysis.     

Conventional radiology and right heart catheterization in estimating primary pulmonary hypertension and pulmonary hypertension secondary to left-sided valvular disease

Aim: to estimate the comparative value of conventional radiology and cardiac catheterization in establishing the diagnosis and severity of primary and secondary pulmonary hypertension. We also tried to achieve some correlations between the radiological and invasive parameters. Methods: we performed a retrospective study over an 11-years time period, analyzing data from a group of 14 patients diagnosed with primary pulmonary hypertension compared to a matched group of 20 patients suffering from pulmonary hypertension secondary to mitral and aortic valvular disease. All the patients had undergone conventional radiology (chest X-ray) and catheterization of the right heart cavities and pulmonary artery. Results: we detected significantly elevated pulmonary artery pressures and resistances in the primary pulmonary hypertension group compared to secondary hypertension patients. Cardiac output values were much lower in the primary pulmonary hypertension individuals compared with secondary pulmonary hypertension in left-sided valvular disease. The pulmonary artery arch diameter, the diameter of the right descending pulmonary artery and the value of the arterio-bronchial ratio were similar in the two groups. Conclusion: in both groups, we found a statistically significant positive correlation between the values of the pulmonary artery vascular resistance and the diameter of the right descending pulmonary artery, which are very specific parameters in the diagnosis of pulmonary hypertension. In the primary pulmonary hypertension group we identified a significant inverse correlation between the diameter of the right descending pulmonary artery and the values of cardiac output. This finding was not confirmed in the secondary group.     

Phenylethyl butyrate enhances the potency of second-line drugs against clinical isolates of Mycobacterium tuberculosis

Ethionamide (ETH) is a second-line drug for the treatment of tuberculosis. As a prodrug, ETH has to be activated by EthA. ethA is controlled by its repressor EthR. 2-Phenylethyl-butyrate (2-PEB) inhibits EthR binding, enhances expression of EthA, and thereby enhances the growth-inhibitory effects of ethionamide, isoxyl, and thiacetazone in Mycobacterium tuberculosis strains with resistance to ETH due to inhA promoter mutations but not ethA mutations.     

Adjunctive daptomycin attenuates brain damage and hearing loss more efficiently than rifampin in infant rat pneumococcal meningitis

Exacerbation of cerebrospinal fluid (CSF) inflammation in response to bacteriolysis by beta-lactam antibiotics contributes to brain damage and neurological sequelae in bacterial meningitis. Daptomycin, a nonlytic antibiotic acting on Gram-positive bacteria, lessens inflammation and brain injury compared to ceftriaxone. With a view to a clinical application for pediatric bacterial meningitis, we investigated the effect of combining daptomycin or rifampin with ceftriaxone in an infant rat pneumococcal meningitis model. Eleven-day-old Wistar rats with pneumococcal meningitis were randomized to treatment starting at 18 h after infection with (i) ceftriaxone (100 mg/kg of body weight, subcutaneously [s.c.], twice a day [b.i.d.]), (ii) daptomycin (10 mg/kg, s.c., daily) followed 15 min later by ceftriaxone, or (iii) rifampin (20 mg/kg, intraperitoneally [i.p.], b.i.d.) followed 15 min later by ceftriaxone. CSF was sampled at 6 and 22 h after the initiation of therapy and was assessed for concentrations of defined chemokines and cytokines. Brain damage was quantified by histomorphometry at 40 h after infection and hearing loss was assessed at 3 weeks after infection. Daptomycin plus ceftriaxone versus ceftriaxone significantly (P < 0.04) lowered CSF concentrations of monocyte chemoattractant protein 1 (MCP-1), MIP-1α, and interleukin 6 (IL-6) at 6 h and MIP-1α, IL-6, and IL-10 at 22 h after initiation of therapy, led to significantly (P < 0.01) less apoptosis, and significantly (P < 0.01) improved hearing capacity. While rifampin plus ceftriaxone versus ceftriaxone also led to lower CSF inflammation (P < 0.02 for IL-6 at 6 h), it had no significant effect on apoptosis and hearing capacity. Adjuvant daptomycin could therefore offer added benefits for the treatment of pediatric pneumococcal meningitis.     

Recent achievements in colorectal cancer diagnostic and therapy by the use of nanoparticles

Colorectal cancer is a major public health issue, being the third most common cancer in men and the second in women. It is one of the leading causes of cancer deaths. Nanomedicine is an emerging field of interest, many of its aspects being linked to cancer research. Chemotherapy has a well-established role in colorectal cancer management, unfortunately being limited by inability to have a selective distribution, by multidrug resistance and adverse effects. Researches carried out in recent years about nanotechnologies aimed, among others, to resolve the issues mentioned above. Targeted and localized delivery of the chemotherapeutic drugs, using nanoparticles, with selective destruction of cancerous cells would minimize the toxicity on healthy tissues. Also, the use of nanomaterials as contrast agent could improve sensitivity and specificity of diagnosis. The purpose of this review is to highlight the recent achievements of cancer research by use of nanomaterials, in the idea of finding the ideal composite, capable to simultaneous diagnostic and treat cancer.     

Krill-Oil-Dependent Increases in HS-Omega-3 Index,Plasma Choline and Antioxidant Capacity in Well-Conditioned Power Training Athletes

There is evidence that both omega-3 polyunsaturated fatty acids (n-3 PUFAs) and choline can influence sports performance, but information establishing their combined effects when given in the form of krill oil during power training protocols is missing. The purpose of this study was therefore to characterize n-3 PUFA and choline profiles after a one-hour period of high-intensity physical workout after 12 weeks of supplementation. Thirty-five healthy power training athletes received either 2.5 g/day of Neptune krill oil^TM (550 mg EPA/DHA and 150 mg choline) or olive oil (placebo) in a randomized double-blind design. After 12 weeks, only the krill oil group showed a significant HS-Omega-3 Index increase from 4.82 to 6.77% and a reduction in the ARA/EPA ratio (from 50.72 to 13.61%) (p < 0.001). The krill oil group showed significantly higher recovery of choline concentrations relative to the placebo group from the end of the first to the beginning of the second exercise test (p = 0.04) and an 8% decrease in total antioxidant capacity post-exercise versus 21% in the placebo group (p = 0.35). In conclusion, krill oil can be used as a nutritional strategy for increasing the HS-Omega-3 Index, recover choline concentrations and address oxidative stress after intense power trainings.     

Recent and lifelong sexual dysfunction in a female UK population sample: prevalence and risk factors

IntroductionTo date, no studies have tried to explore the prevalence and risk factors of recent and lifelong female sexual dysfunction (FSD) in the United Kingdom using validated questionnaires for the assessment of symptom severity and levels of associated sexual distress.AimTo estimate the prevalence and comorbidity of recent and lifelong FSD and to further identify potential psychosocial and behavioral risk factors in a nationally representative sample of UK women.MethodsOne thousand four hundred eighty‐nine unselected female twin individuals aged 18–85 years. Validated questionnaires, such as the Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale, were used for the assessment of symptom severity and degree of sexual distress.Main Outcome MeasuresPrevalence and comorbidity of recent and lifelong FSD according to the FSFI cutoff points and the existence of sexual distress. Lifelong FSD refers to an individual's average sexual function ever since they have been sexually active. We further calculated odds ratios (ORs) with 95% confidence interval for FSD.ResultsWe found that 5.8% of women reported any recent sexual dysfunction and 15.5% reported any lifelong sexual dysfunction. Hyposexual desire was the most prevalent recent and lifelong sexual complaint (21.4% and 17.3%, respectively). High intercorrelations were found for both recent and lifelong FSD (r = 0.3–0.7). The most common independent, clinical predictor of recent and lifelong FSD diagnosis was relationship dissatisfaction (OR 1.2–4.5). Experience of abuse (OR 1.6–2.1), increased anxiety, and obsessive compulsive behavior were the most common predictors for lifelong FSD.ConclusionsThe study provides the first UK population‐based assessment of recent and lifelong FSD using validated outcome measures and accounting for sexual distress. Our results indicate that FSD is common in the general population and is influenced by psychosocial factors with different pathoetiologies underlying recent and lifelong FSD. Burri A and Spector T. Recent and lifelong sexual dysfunction in a female UK population sample: Prevalence and risk factors. J Sex Med 2011;8:2420–2430.