Neuroscience of the auditory-motor system: How does sound interact with movement?

Human musicality is a complex problem because it involves the coupling of multiple exogenous and endogenous signals with different physical properties. The synchronization of these signals translates into specific behaviors. The study of this synchronization, based on the physical properties of two oscillatory bodies, is the first step in understanding the behaviors associated with rhythmic auditory stimuli. In recent years, different neurorehabilitation therapies have emerged for motor pathologies involving music. However, the neurophysiological bases that describe the coupling phenomenon are not yet fully understood. In this article, two theories are addressed that attempt to explain the convergence of the auditory system and the motor system according to new neuroanatomical, neurophysiological and artificial neural network findings. It also reflects on the different approaches to a complex problem in cognitive neuroscience and the need for a study model for the different motor behaviors evoked by auditory stimuli.

[Detection of Borrelia burgdorferi antibodies in a population sample of the state of Zulia]. / Detección de anticuerpos contra Borrelia burgdorferi en una muestra poblacional del estado Zulia.

Between July 1992 and September 1993 an investigation was carried out in a population of Zulia State, Venezuela, in order to detect antibodies against Borrelia burgdorferi for the diagnosis of Lyme disease. A total of 74 patients were studied: 37 asymptomatic and 37 patients clinically suspected having the disease. ELISA tests were performed to determine antibodies against Borrelia burgdorferi. The positive cases, confirmed by duplicate, were tested with VDRL, Monotest, Rheumatoid Factor and Antinuclear Antibodies to eliminate false positives. The total positive cases were 14 of 74 (18.9%). Positive cases in the symptomatic group (29.7%) were higher than in the asymptomatic group (8.9%). The most frequent clinical diagnosis was Morfea (54.5%). The major serological diagnosis (54.32%) was obtained from the chronic patients (more than a year of evolution). A 45.5% of symptomatic patients presented antibodies, despite of receiving antibiotic treatment. Most of the symptomatic positive cases, and also the asymptomatic cases, had a previous visit or permanence in forestal or rural areas. The results of this investigation prove the existence of antibodies against Borrelia burgdorferi in the population of Zulia State, both in the symptomatic as well as in the asymptomatic patients. These results open the path to use a more specific test like immunoblot, for the diagnosis of Lyme disease in our area.

[Candida in biological human samples]. / Candida en muestras biológicas corporales.

Infections by Candida have been raising in the last decades, and risk factors, mainly immunosuppression and the appearance of Candida no albicans, are determinants in the prognosis of these mycoses. The purpose of this investigation was to identify and establish the prevalence of C. albicans and Candida spp. in candidiases, in patients to the Hospital Universitario de Maracaibo, whose biological samples were processed for both direct examination and cultures, needed for the proper identification. From October 1996 to October 1998, isolation and identification of yeasts of Candida were performed in 177 biological samples: 73 (41.24%) Candida albicans and 104 (58.75%) Candida spp. Both blastoconidias and pseudohyphae were found in 34 samples (19.21%), 24 of which (70.5%) were diagnosed as C. albicans and 10 (29.5%), as Candida spp. Blastoconidias identified by direct method were distributed as C. albicans 34.2% and Candida spp. 65.7%. C. albicans was found more often in intertrigo, sputum and in bronquial lavage samples. Candida spp. was more frequent in nails. Candidiasis is a frequently diagnosed mycosis in hospitals, mainly among immunossuppresed patients. It is very important to use direct microscopical evaluation and cultures, in order to establish the presence of blastoconidias and pseudohyphae, that will help to diagnose the aethiology and prevalence of candidiasis. It is also important to recognize subungueal candidiasis in hospital staff, that could spread the infection to inpatients.

Chronic administration of thiamine pyrophosphate decreases age-related histological atrophic testicular changes and improves sexual behavior in male Wistar rats.

Aging is a multifactorial universal process and constitutes the most important risk factor for chronic-degenerative diseases. Although it is a natural process, pathological aging arises when these changes occur quickly and the body is not able to adapt. This is often associated with the generation of reactive oxygen species (ROS), inflammation, and a decrease in the endogenous antioxidant systems, constituting a physiopathological state commonly found in chronic-degenerative diseases. At the testicular level, aging is associated with tissue atrophy, decreased steroidogenesis and spermatogenesis, and sexual behavior disorders. This situation, in addition to the elevated generation of ROS in the testicular steroidogenesis, provides a critical cellular environment causing oxidative damage at diverse cellular levels. To assess the effects of a reduction in the levels of ROS, thiamine pyrophosphate (TPP) was chronically administered in senile Wistar rats. TPP causes an activation of intermediate metabolism routes, enhancing cellular respiration and decreasing the generation of ROS. Our results show an overall decrease of atrophic histological changes linked to aging, with higher levels of serum testosterone, sexual activity, and an increase in the levels of endogenous antioxidant enzymes in TPP-treated animals. These results suggest that TPP chronic administration decreases the progression of age-related atrophic changes by improving the intermediate metabolism, and by increasing the levels of antioxidant enzymes.

HOMA-IR and non-HDL-C as predictors of high cholesteryl ester transfer protein activity in patients at risk for type 2 diabetes.

BACKGROUND AND AIMS: Metabolic syndrome (MS) and type 2 diabetes are highly associated with an abnormal lipoprotein profile, which may be generated and accentuated by high cholesteryl ester transfer protein (CETP) activity. Given the difficulty in measuring CETP activity, the aim was to identify simple biochemical predictors of high CETP activity. DESIGN AND METHODS: Eighty five subjects at risk for type 2 diabetes were classified according to the presence of MS. Lipoprotein profile, HOMA-IR and endogenous CETP activity were evaluated. RESULTS: As expected, MS patients presented higher concentration of glucose, insulin, triglycerides and non-HDL-C and lower HDL-C levels. Moreover, MS patients exhibited increased HOMA-IR and CETP activity. Employing a ROC curve for MS, high CETP activity was defined as >250%ml⁻¹ h⁻¹. The predictive variables of high CETP were non-HDL-C≥160mg/dl (OR=11.1;95%IC=3.3-38.2;p<0.001) and HOMA-IR>2.1 (OR=4.4;95%IC=1.3-14.8;p<0.05). CONCLUSIONS: High non-HDL-C and insulin resistance were predictors for increased CETP activity which measurement is not accessible for clinical laboratories.

Serotipificación de candida albicans en aislados de muestras clínicas / Seratypification of candidad albicans in clinical sample isolates

Se realizó el estudio en levaduras provenientes de muestras biológicas remitidas a la Sección de Micología del Departamento de Laboratorio Clínico del Hospital Universitario de Maracaibo y se procedió a la serotificación de las especies de Candida albicans aisladas en forma aleatoria. Las 152 muestras estudiadas fueron positivas al directo y cultivo en su toalidad y correspondieron a C.albicans 61 (40,13 por ciento) y a Candida no albicans 91 (59,87 por ciento). De las muestras estudiadas, en 22 (14,47 por ciento) se observó la presencia de blastoconidias y pseudomicelio, correspondiendo 15 (68,18 por ciento) a C.albicans y 7 (31,82 por ciento) a Candida no albicans. En los casos en que se observaron solamente blastoconidias al examen directo, se identificó C.albicans en 46 (35,38 por ciento) y Candida no albicans en 84 (64,62 por ciento). C.albicans fue más frecuente en las muestras de lavado bronquial. El serotipo de 24 cepas de C.albicans, escogidas en forma aleatoria, se encontró: 23 (95,83 por ciento) cepas del serotipo A y 1 cepa del serotipo B (4,17 por ciento) en una muestra de lavado bronquial. Se observó predominio del serotipo A, tal como se reporta en diferentes trabajos de serotipificación en muestras biológicas