Causes and treatment of idiopathic benign paroxysmal positional vertigo based on endocrinological and other metabolic factors

The genesis of the Benign Paroxysmal Positional Vertigo (BPPV) seems to be related to some metabolic factors. These factors, such as vitamin D, glucocorticoids, and even thyroid and growth hormones, can affect bone metabolism and the mineralization of otoconia. It also seems to link to factors related to aging or nutritional habits. Besides, since the incidence of BPPV is quantitatively higher in women than in men, female sex steroids could be associated with this process. It could be useful to understand how these factors act in otoconial mineralization if we want to develop treatments aimed at preventing or delaying BPPV recurrences. In this review, we will analyze the role of these metabolic and hormonal factors in otoconial mineralization and in the treatment of BPPV.     

Selective effect of conjugated linoleic acid isomers on atherosclerotic lesion development in apolipoprotein E knockout mice

Research suggests that conjugated linoleic acid (CLA) may inhibit atherosclerosis, but there are contradictory results in different animal models fed heterogeneous mixtures of CLA isomers. This study addressed the hypothesis that the individual CLA isomers may exert different atherogenic properties. ApoE(-/-) mice were fed isocaloric, isonitrogenous westernized diets containing 0.15% cholesterol and enriched with 1% (w/w) cis-9,trans-11-CLA (c9,t11-CLA), trans-10,cis-12-CLA (t10,c12-CLA) or linoleic acid (control diet) for 12 weeks. At the end of the dietary intervention, the effects of CLA isomers on the development of atherosclerotic vascular lesions, lipid metabolism, inflammation and oxidative stress were assessed. The t10,c12-CLA diet had a profound pro-atherogenic effect, whereas c9,t11-CLA impeded the development of atherosclerosis. En face aortic lesion assessment showed more dorsal and lumbar extensions presenting atherosclerotic foci after the t10,c12-CLA diet. Furthermore, animals fed t10,c12-CLA had pronounced hyperlipidemia, higher 8-iso-prostaglandin F(2alpha) levels, higher vulnerable atherosclerotic plaque with a lower smooth muscle and fibre contents and higher macrophage content and activation, assayed as plasma chitotriosidase compared to the control or c9,t11-CLA dietary groups. Plasma chitotriosidase activity was more closely associated with the extent of the plaque than with MOMA staining or than monocyte chemoattractant protein-1 levels. Our results demonstrate that CLA isomers differentially modulate the development of atherosclerosis, c9,t11-CLA impedes, whereas t10,c12-CLA promotes atherosclerosis. These opposing effects may be ascribed to divergent effects on lipid, oxidative, inflammatory and fibro muscular components of this pathology. Plasma chitotriosidase is a better indicator of dietary fat interventions that alter plaque monocyte activity in this murine model.     

El síndrome de apnea del sueño,la ventilación mecánica y los cuidados críticos en archivos de bronconeumología (diciembre 2009-diciembre 2010)

The present study aims to review all the major articles on respiratory sleep disorders, mechanical ventilation, and respiratory critical care published in the last year in Archivos de bronconeumología. Between December 2009 and November 2010, 15 studies on these topics were published in Archivos de bronconeumología. Ten of these studies dealt with respiratory sleep disorders, consisting of six original articles, one special article, one review article, one letter to the editor and one supplement on chronic obstructive pulmonary disease and its association with sleep apneas. Five articles were published on non-invasive mechanical ventilation: one editorial, one special article, one article in a supplement and two original articles. As in previous years, there was a marked difference in the number of articles published on non-invasive mechanical ventilation and sleep-apnea syndrome, with a greater number of articles being published on the latter. Although some articles highlight the importance of the place where ventilation is commenced, no study specifically dealing with intermediate care units was published in Archivos de bronconeumología in 2010. This absence could be interpreted as a result of the low implantation of this type of unit in Spain, contrasting with the high activity undertaken in this field by pneumology services.     

Non-invasive atrial fibrillation organization follow-up under successive attempts of electrical cardioversion

The development of non-invasive tools able to provide valuable information about the effectiveness of a shock in external electrical cardioversion (ECV) is clinically relevant to enhance these protocols in the treatment of atrial fibrillation (AF). The present contribution analyzes the ability of a non-linear regularity index, such as sample entropy (SampEn), to follow-up non-invasively AF organization under successive attempts of ECV and to predict the effectiveness of every single shock. To this respect, the atrial activity (AA) preceding each delivered shock was extracted by using a QRST cancellation method. Next, the main atrial wave (MAW), which can be considered as the fundamental waveform associated to the AA, was obtained by applying a selective filtering centered on the dominant atrial frequency (DAF). Finally, the MAW organization was estimated with SampEn and two thresholds (Th1 = 0.1223 and Th2 = 0.0832) were established to predict the ECV outcome. Results indicated that, prior to the first attempt, all the patients who needed only one shock to restore NSR were below Th1. In addition, most of them were above Th2 in case of AF relapsing during the first month. Regarding several shocks, all the patients who maintained NSR more than one month were below Th2 after the first shock. Moreover, all the patients who relapsed to AF during the first month were between Th1 and Th2 and, finally, all the patients with ineffective ECV were above Th1. After each unsuccessful shock, a SampEn relative decrease was observed for the patients who finally reverted to NSR, but the largest variation took place after the first attempt, thus indicating that this shock plays the most important role in the procedure. Indeed, by considering jointly the patients who needed only one shock and the patients who needed several shocks, 91.67% (22 out of 24) of ECVs resulting in NSR, 93.55% (29 out of 31) of ECVs relapsing to AF during the first month and 100% (10 out of 10) of ECVs in which NSR was not restored were correctly classified. As conclusion, the MAW organization analysis via SampEn can provide useful information that could improve the effectiveness of conventional external ECV protocols used in AF treatment.     

Resequencing and association analysis of arylalkylamine N‐acetyltransferase (AANAT) gene and its contribution to major depression susceptibility

Abstract: Circadian rhythms disruptions, including abnormalities of circadian phase position and melatonin secretion, have been described in major depression (MD). Arylalkylamine N‐acetyltransferase (AANAT) is a key enzyme of the melatonin pathway involved in circadian oscillations of melatonin levels. We assessed the contribution of AANAT gene variability to susceptibility to MD considering common and rare genetic variations through a sequential sequencing and single nucleotide polymorphism (SNP)‐based genotyping approach in a sample of 445 unrelated patients with MD (257 unipolar MD, 188 bipolar depression) and 440 community‐based screened control subjects. We identified 17 sequence changes, thirteen of which represented novel sequence variations. We did not observe an over‐representation of patients carrying rare variants compared with the healthy controls. Common variants (MAF > 2%) were included in a case–control association analysis that showed significant association after multiple testing correction of two SNPs located in the promoter region of AANAT with MD: rs3760138 (P = 0.00006) and rs4238989 (P = 0.005). Multimarker analysis found significant associations between two three‐marker protective haplotypes and a susceptibility three‐marker haplotype containing the rare alleles of rs3760138‐rs4238989‐rs8150 and MD. We present evidence of the association of genetic variability in the AANAT gene with susceptibility to MD. Our results support the hypothesis that the melatonin‐signaling pathway and circadian clock mechanisms may contribute to the pathophysiology of MD.     

Neuropharmacological effects of lipoic acid and ubiquinone on δ‐aminolevulinic dehydratase,Na+, K+‐ATPase,and Mg2+‐ATPase activities in rat hippocampus after pilocarpine‐induced seizures

In this study, we investigated the effects of lipoic acid (LA) in the hippocampus oxidative stress caused by pilocarpine‐induced seizures in adult rats. Wistar rats were treated with 0.9% saline (i.p., control group), LA (10 mg/kg, i.p., LA group), ubiquinone [20 mg/kg, i.p., ubiquinone (UQ) group], pilocarpine (400 mg/kg, i.p., P400 group), and the association of LA (10 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.) or UQ (20 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.), 30 min before of administration of P400 (LA plus P400 group and UQ plus P400 group, respectively). After the treatments, all groups were observed for 1 h. The enzyme activities (δ‐aminolevulinic dehydratase (δ‐ALA‐D), Mg²⁺‐ATPase, and Na⁺, K⁺‐ATPase) were measured using spectrophotometric methods, and the results compared to values obtained from saline and pilocarpine‐treated animals. Protective effects of LA and UQ were also evaluated on the same parameters. We reported here for the first time that Na⁺, K⁺‐ATPase and δ‐ALA‐D activities inhibition and Mg²⁺‐ATPase stimulation in the pilocarpine model are probably attributed to the oxidative stress caused by seizures in the rat hippocampus. The addition of the antioxidants LA and UQ may reverses the previously mentioned Na⁺, K⁺‐ATPase and δ‐ALA‐D inhibitions and Mg²⁺‐ATPase stimulation. Conclusions: The oxidative stress plays an important signaling role in pilocarpine‐induced seizures, and antioxidant drugs might be considered as therapeutical tools in this pathology.