Growth hormone-releasing hormone is produced by adipocytes and regulates lipolysis through growth hormone receptor.

BACKGROUND: Growth hormone-releasing hormone (GHRH) has a crucial role in growth hormone (GH) secretion, but little is known about its production by adipocytes and its involvement in adipocyte metabolism. OBJECTIVES: To determine whether GHRH and its receptor (GHRH-R) are present in human adipocytes and to study their levels in obesity. Also, to analyze the effects of GHRH on human adipocyte differentiation and lipolysis. METHODS: GHRH/GHRH-R and GH/GH-R mRNA expression levels were analyzed in human mature adipocytes from non-obese and morbidly obese subjects. Human mesenchymal stem cells (HMSC) were differentiated to adipocytes with GHRH (10-14-10-8 M). Adipocyte differentiation, lipolysis and gene expression were measured and the effect of GH-R silencing was determined. RESULTS: Mature adipocytes from morbidly obese subjects showed a higher expression of GHRH and GH-R, and a lower expression of GHRH-R and GH than non-obese subjects (P<0.05). A total of 10-14-10-10 M GHRH induced an inhibition of lipid accumulation and PPAR-γ expression (P<0.05), and an increase in glycerol release and HSL expression (P<0.05) in human differentiated adipocytes. A total of 10-12-10-8 M GHRH decreased GHRH-R expression in human differentiated adipocytes (P<0.05). A total of 10-10-10-8 M GHRH increased GH and GH-R expression in human differentiated adipocytes (P<0.05). The effects of GHRH at 10-10 M on adipocyte differentiation and lipolysis were blocked when GH-R expression was silenced. CONCLUSIONS: GHRH and GHRH-R are expressed in human adipocytes and are negatively associated. GHRH at low doses may exert an anti-obesity effect by inhibiting HMSC differentiation in adipocytes and by increasing adipocyte lipolysis in an autocrine or paracrine pathway. These effects are mediated by GH and GH-R.

[Declaration of the Chilean Academy of Medicine of Law 20.850 “On clinical trials of pharmaceutical products and medical devices” and of the bylaw that will regulate its application]. / Declaración de la Academia Chilena de Medicina sobre el Título V de la Ley 20.850 (Ley Ricarte Soto) y su proyecto de reglamento “De los ensayos clínicos de productos farmacéuticos y elementos de uso médico”.

In Chile, high cost treatments required by selected medical conditions are financed by the State, according to Law 20.850. A bylaw under discussion by the Senate regulates clinical trials, posing complex issues that will endanger local interest in front-line research: 1. The exclusive and mandatory control bestowed to the Institute of Public Health during all stages of the trials and also the surveillance of institutions performing clinical trials, overriding their Clinical Research Review Boards; 2.The 10 year period during which any adverse event is assumed to have been caused by the medication or devise evaluated by the trial, unless the contrary is proven in a judicial process; 3. Individuals submitted to the trials are entitled to free post trial access to the treatment received during the study, financed by the trial supporting entities and as long as the drug or devise is considered to be useful. While agreeing with the need to have a National Registry of Clinical Trials, we predict that the mentioned critical issues in the bylaw will lead to difficulties and unnecessary judicial processes, thus limiting clinicians’ interest in performing research. We propose to modify the bylaw, excluding responsibilities on events associated with the natural evolution of the medical condition, with patients’ ageing or with comorbidities and clinical events considered unpredictable when the protocol was accepted. We recommend that the free post trial access should be a joint decision involving the patient and the attending physician, taking in consideration that the volunteer has been exposed to risks and burdens, or when discontinuation of treatment entails a vital risk until the treatment under study has been approved and becomes available in the national market.

Characterization of the promoter of Grapevine vein clearing virus.

Grapevine vein clearing virus (GVCV) is a recently discovered DNA virus in grapevine that is closely associated with the grapevine vein clearing syndrome observed in vineyards in Missouri and surrounding states. The genome sequence of GVCV indicates that it belongs to the genus Badnavirus in the family Caulimoviridae. To identify the GVCV promoter, we cloned portions of the GVCV large intergenic region in front of a GFP gene present in an Agrobacterium tumefaciens binary vector. GFP expression was assessed by ELISA 3 days after agroinfiltration of Nicotiana benthamiana leaves. We found that the GVCV DNA segment between nts 7332 and 7672 directed expression of GFP and this expression was stronger than expression using the Cauliflower mosaic virus 35S promoter. It was revealed by 5' and 3' RACE that transcription was initiated predominantly at nt 7571 and terminated at nt 7676.

Changes in thyroid function with age: results from the Pizarra population-based longitudinal study.

BACKGROUND: Results of studies examining the influence of age on thyroid function and TSH levels, in the absence of thyroid disease, remain controversial. The aim of this study was to determine the course of thyroid function over 11 years in a population with normal thyroid function. METHODS: This is a population-based prospective study started in 1995-1997 (first phase), and reassessed 6 (second phase) and 11 years later (third phase). RESULTS: The TSH and FT4 in the third phase were significantly increased (p=0.001 and p=0.001, respectively), with the values being higher particularly from the age of 50 years. In those persons with a baseline TSH≥1.2 and <3 µIU/mL, the OR of having a TSH of 3-5 µIU/mL in the third phase was 6.10 (p=0.004). In those with a baseline TSH≥3 and ≤5 µIU/mL, the OR of having a TSH of 3-5 µIU/mL in the third phase was 20.8 (p<0.0001). Similar results were found for FT4. CONCLUSION: In a population free of clinical thyroid disease, TSH and FT4 values rise over the years. This increase occurs in all age groups, but depends mainly on the basal concentrations of TSH and FT4.

[An analysis of Chilean biomedical publications in PubMed in the years 2008-2009]. / Análisis de las publicaciones biomédicas chilenas indizadas en PubMed, en los años 2008 y 2009.

BACKGROUND: During the years 2008 and 2009, 1,191 biomedical articles authored by Chilean investigators working in Chile were indexed in PubMed. AIMS: To evaluate the potential visibility of those articles, according to scientometric indexes of the journals where they were published. METHODS: Those journals where the articles had been published were identified and each journal’s Impact Factor (JIF), 5-year JIF, SCImago Journal Rank (SJR), SCImago Quartiles (Q) for 2010 and the Source Normalized Impact per Paper (SNIP) for 2008-2009 were identified. RESULTS: Three hundred and twelve articles (26,2%) were dedicated to experimental studies in animals, tissues or cells and they were classified as “Biomedicine”, while 879 (73,8%) were classified as “Clinical Medicine”; in both areas the main type of articles were original reports (90% and 73.6%, respectively). Revista Médica de Chile and Revista Chilena de Infectología concentrated the greater number of publications. Articles classified in Biomedicine were published more frequently in English and in journals with higher scientometric indexes than those classified in Clinical Medicine. CONCLUSIONS: Biomedical articles dealing with clinical topics, particularly case reports, were published mostly in national journals or in foreign journals with low scientometric indexes. It can be partly attributable to the authors’ interest in reaching local readers. The evaluation of research productivity should combine several scientometric indexes, selected according to the field of research, the institution's and investigators’ interests, with a qualitative and multifactorial assessment.

Thyroid hormone receptor alpha gene variants increase the risk of developing obesity and show gene-diet interactions.

OBJECTIVE: Thyroid hormone receptor-beta resistance has been associated with metabolic traits. THRA gene sequencing of an obese woman (index case) who presented as empirical thyroid hormone receptor-α (THRA) resistance, disclosed a polymorphism (rs12939700) in a critical region involved in TRα alternative processing. DESIGN AND SUBJECTS: THRA gene variants were evaluated in three independent europid populations (i) in two population cohorts at baseline (n=3417 and n=2265), 6 years later (n=2139) and (ii) in 4734 high cardiovascular risk subjects (HCVR, PREDIMED trial). RESULTS: The minor allele of the index case polymorphism (rs12939700), despite having a very low frequency (4%), was significantly associated with higher body mass index (BMI) (P=0.042) in HCVR subjects. A more frequent THRA polymorphism (rs1568400) was associated with higher BMI in subjects from the population (P=0.00008 and P=0.05) after adjusting for several confounders. Rs1568400 was also strongly associated with fasting triglycerides (P dominant=3.99 × 10(-5)). In the same sample, 6 years later, age and sex-adjusted risk of developing obesity was significantly increased in GG homozygotes (odds ratio 2.93 (95% confidence interval, 1.05-6.95)). In contrast, no association between rs1568400 and BMI was observed in HCVR subjects, in whom obesity was highly prevalent. This might be explained by the presence of an interaction (P <0.001) among the rs1568400 variant, BMI and saturated fat intake. Only when saturated fat intake was high (>24.5 g d(-1)), GG carriers showed a significantly higher BMI than A carriers after controlling for energy intake and physical activity. CONCLUSIONS: THRA gene polymorphisms are associated with obesity development. This is a novel observation linking the THRA locus to metabolic phenotypes.

Mediterranean diet adherence in individuals with prediabetes and unknown diabetes: the Di@bet.es Study.

BACKGROUND AND AIMS: Mediterranean diet (MedDiet) is causally related to diabetes and is a dietary pattern recommended to individuals with diabetes. We investigated MedDiet adherence in individuals with prediabetes and unknown (PREDM/UKDM) or known diabetes (KDM) compared to those with normal glucose metabolism (NORMAL). METHODS: This was a national, population-based, cross-sectional, cluster-sampling study. MedDiet adherence was scored (MedScore, mean ± SD 24 ± 5) using a qualitative food frequency questionnaire. Logistic regression was used to examine the association between MedScore and PREDM/UKDM or KDM versus control subjects. RESULTS: We evaluated 5,076 individuals. Mean age was 50 years, 57% were female, 826 (582/244) were PREDM/UKDM, 478 were KDM and 3,772 were NORMAL. Mean age increased across MedScore tertiles (46, 51 and 56 years, p < 0.0001). Higher age-adjusted adherence to MedDiet (5-unit increment in the MedScore) was associated with lower and nondifferent odds (OR, 95% CI) of prevalent PREDM/UKDM (0.88, 0.81-0.96, p = 0.001) and KDM (0.97, 0.87-1.07, p = 0.279), respectively, compared to individuals in the NORMAL group. CONCLUSIONS: In a representative sample of the whole Spanish population, MedDiet adherence is independently associated with PREDM/UKDM. Therapeutic intervention may be, in part, responsible for the lack of differences in adherence observed between the KDM and NORMAL groups. However, reverse causation bias cannot be ruled out in cross-sectional studies.

Prevalence of diabetes mellitus and impaired glucose regulation in Spain: the Di@bet.es Study.

AIMS/HYPOTHESIS: The Di@bet.es Study is the first national study in Spain to examine the prevalence of diabetes and impaired glucose regulation. METHODS: A population-based, cross-sectional, cluster sampling study was carried out, with target population being the entire Spanish population. Five thousand and seventy-two participants in 100 clusters (health centres or the equivalent in each region) were randomly selected with a probability proportional to population size. Participation rate was 55.8%. Study variables were a clinical and demographic structured survey, lifestyle survey, physical examination (weight, height, BMI, waist and hip circumference, blood pressure) and OGTT (75 g). RESULTS: Almost 30% of the study population had some carbohydrate disturbance. The overall prevalence of diabetes mellitus adjusted for age and sex was 13.8% (95% CI 12.8, 14.7%), of which about half had unknown diabetes: 6.0% (95% CI 5.4, 6.7%). The age- and sex-adjusted prevalence rates of isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT) and combined IFG-IGT were 3.4% (95% CI 2.9, 4.0%), 9.2% (95% CI 8.2, 10.2%) and 2.2% (95% CI 1.7, 2.7%), respectively. The prevalence of diabetes and impaired glucose regulation increased significantly with age (p < 0.0001), and was higher in men than in women (p < 0.001). CONCLUSIONS/INTERPRETATION: The Di@bet.es Study shows, for the first time, the prevalence rates of diabetes and impaired glucose regulation in a representative sample of the Spanish population.

[Main characteristics of current biomedical research, in Chile]. / Principales características de la investigación biomédica actual, en Chile.

BACKGROUND: Biomedical research is a fundamental tool for the development of a country, requiring human and financial resources. AIM: To define some current characteristics of biomedical research, in Chile. METHODS: Data on entities funding bio-medical research, participant institutions, and the number of active investigators for the period 2007-2009 were obtained from institutional sources; publications indexed in PubMed for 2008-2009 were analysed. RESULTS: Most financial resources invested in biomedical research projects (approximately US$ 19 million per year) came from the "Comisión Nacional de Investigación Científica y Tecnológica" (CONICYT), a state institution with 3 independent Funds administering competitive grant applications open annually to institutional or independent investigators in Chile. Other sources and universities raised the total amount to US$ 26 million. Since 2007 to 2009, 408 investigators participated in projects funded by CONICYT. The main participant institutions were Universidad de Chile and Pontificia Universidad Católica de Chile, both adding up to 84% of all funded projects. Independently, in 2009,160 research projects -mainly multi centric clinical trials- received approximately US$ 24 million from foreign pharmaceutical companies. Publications listed in PubMed were classified as "clinical research" (n = 879, including public health) or "basic biomedical research" (n = 312). CONCLUSIONS: Biomedical research in Chile is mainly supported by state funds and university resources, but clinical trials also obtained an almost equivalent amount from foreign resources. Investigators are predominantly located in two universities. A small number of MD-PhD programs are aimed to train and incorporate new scientists. Only a few new Medical Schools participate in biomedical research. A National Registry of biomedical research projects, including the clinical trials, is required among other initiatives to stimulate research in biomedical sciences in Chile.

[Human pregnancy, a biological paradigm of tolerance and adaptation]. / El embarazo humano: paradigma biológico de tolerancia y adaptación.

This review analyses the changes in immunological tolerance, and the systemic and local hemodynamic changes observed along human pregnancy. To underscore the conceptual importance of tolerance and adaptation the background is provided by the two main advocates of these ideas: Gandhi and Darwin. The cognate factors that determine immunological tolerance (IT), systemic (SA) and local adaptation (LA) are multiple; IT = desensitisation to paternal antigens, absence of HLA-A, roles of HLA-G, natural killer cells and their receptors; SA = decreased vascular resistance, plasma volume expansion, increased cardiac output and plasma renin activity; LA = prostacyclin, nitric oxide, kallikrein-kinin system, vasodilator arm of the renin angiotensin system, vascular endothelial growth factor (VEGF). A possible role of vasodilators in the crucial process of trophoblast invasion and uterine artery transformation is supported. The relevance of an adequate adaptation to pregnancy is highlighted not only by the intragestational complications derived from a defective process, such as intrauterine growth restriction, preterm birth, and preeclampsia -its foremost expression- but also by the long term cardiovascular complications of the mother and her offspring.

Fatty liver index as a predictor for type 2 diabetes in subjects with normoglycemia in a nationwide cohort study.

Our aim was to evaluate whether fatty liver index (FLI) is associated with the risk of type 2 diabetes (T2DM) development within the Spanish adult population and according to their prediabetes status; additionally, to examine its incremental predictive value regarding traditional risk factors. A total of 2260 subjects (Prediabetes: 641 subjects, normoglycemia: 1619 subjects) from the Di@bet.es cohort study were studied. Socio-demographic, anthropometric, clinical data and survey on habits were recorded. An oral glucose tolerance test was performed and fasting determinations of glucose, lipids and insulin were made. FLI was calculated and classified into three categories: Low (< 30), intermediate (30-60) and high (> 60). In total, 143 people developed diabetes at follow-up. The presence of a high FLI category was in all cases a significant independent risk factor for the development of diabetes. The inclusion of FLI categories in prediction models based on different conventional T2DM risk factors significantly increase the prediction power of the models when all the population was considered. According to our results, FLI might be considered an early indicator of T2DM development even under normoglycemic condition. The data also suggest that FLI could provide additional information for the prediction of T2DM in models based on conventional risk factors.

Incidence of diabetes mellitus in Spain as results of the nation-wide cohort di@bet.es study.

Our aim was to determine the incidence of type 2 diabetes mellitus in a nation-wide population based cohort from Spain (di@bet.es study). The target was the Spanish population. In total 5072 people older than 18 years,were randomly selected from all over Spain). Socio-demographic and clinical data, survey on habits (physical activity and food consumption) and weight, height, waist, hip and blood pressure were recorder. A fasting blood draw and an oral glucose tolerance test were performed. Determinations of serum glucose were made. In the follow-up the same variables were collected and HbA1c was determined. A total of 2408 subjects participated in the follow-up. In total, 154 people developed diabetes (6.4% cumulative incidence in 7.5 years of follow-up). The incidence of diabetes adjusted for the structure of age and sex of the Spanish population was 11.6 cases/1000 person-years (IC95% = 11.1-12.1). The incidence of known diabetes was 3.7 cases/1000 person-years (IC95% = 2.8-4.6). The main risk factors for developing diabetes were the presence of prediabetes in cross-sectional study, age, male sex, obesity, central obesity, increase in weight, and family history of diabetes. This work provides data about population-based incidence rates of diabetes and associated risk factors in a nation-wide cohort of Spanish population.

Incidence of type 2 diabetes in southern Spain (Pizarra Study).

BACKGROUND: Few European studies have used an oral glucose tolerance test (OGTT) to examine the incidence of type 2 diabetes. We determined the incidence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes in a population from southern Spain. MATERIAL AND METHODS: A population-based cohort study was undertaken in Pizarra, Spain. Baseline data were recorded on age, sex, weight, height, waist and hip circumferences, and diabetes status for 1051 persons, of whom 910 were free of type 2 diabetes (at-risk sample). Of these, 714 completed the 6-year follow-up study. Body mass index, waist-to-hip ratio and weight increase since baseline were calculated. The homeostasis model assessment equations were used to estimate the indices of insulin resistance and beta-cell function. Each person received an OGTT at baseline and after 6 years. RESULTS: Type 2 diabetes developed in 81 people for a total of 4253 person-years, representing an incidence of 19.1 cases per 1000 person-years (95% confidence interval, 15.3-23.6). Age and the presence of obesity, central obesity and carbohydrate metabolism disorders [IFG (cut off = 100 mg dL(-1), capillary blood glucose level), IGT or both] at baseline were significant markers for the onset of type 2 diabetes during follow-up. After adjusting for these variables, multivariate analysis showed weight increase, waist-to-hip ratio and the indices of insulin resistance and beta-cell function were significantly associated with the risk for type 2 diabetes. CONCLUSIONS: The incidence of type 2 diabetes in a population from southern Spain is high. It is probably associated with the high prevalence of obesity and weight increase in this population.

Are endometrial cancer radiotherapy results age related?

OBJECTIVE: To analyze the impact of age on radiotherapy results based on cancer-specific survival (CSS), vaginal-cuff relapses (VCR) and complications analysis in 438 patients with endometrial carcinoma (EC) receiving postoperative radiotherapy (PRT) divided into three age groups for analysis. MATERIALS AND METHODS: From 2003 to 2015, 438 patients with EC were treated with PRT and divided into three age groups: Group-1: 202 patients < 65 years; Group-2: 210 patients ≥ 65 and < 80 years; Group-3: 26 patients ≥ 80 years. Vaginal toxicity was assessed using the objective LENT-SOMA criteria and RTOG scores were recorded for the rectum, bladder, and small bowel. STATISTICS: Chi square and Student's t tests, Kaplan-Meier survival study for analysis of CSS. RESULTS: The mean follow-up was 5.6 years in Group-1, 5.6 years in Group-2 and 6.3 years in Group-3 (p = 0.38). No differences were found among the groups in distribution of stage, grade, myometrial invasion, Type 1 vs. 2 EC and VLSI (p = 0.97, p = 0.52, p = 0.35, p = 0.48, p = 0.76, respectively). There were no differences in rectal, bladder and vagina late toxicity (p = 0.46, p = 0.17, p = 0.75, respectively). A better CSS at 5 years was found in Group-1 (p = 0.006), and significant differences were found in late severe small bowel toxicity in Group-3 (p = 0.005). VCR was increased in Group-3 (p = 0.017). CONCLUSIONS: Patients ≥ 65 years had a worse outcome in comparison to younger patients. Late vaginal, rectal and bladder toxicities were similar in the three groups, although an increase of severe late small bowel toxicity led to IMRT in patients ≥ 80 years. Further larger studies are needed including quality of life analysis in patients ≥ 80 years.

Effects of different surface modifying agents on the cytotoxic and antimicrobial properties of ZnO nanoparticles.

Zinc oxide (ZnO) nanoparticles (NPs) have received considerable attention in the medical field because of their antibacterial properties, primarily for killing and reducing the activity of numerous microorganisms. The purpose of this study was to determine whether surface-modified ZnO NPs exhibit different properties compared with unmodified ZnO. The antimicrobial and cytotoxic properties of modified ZnO NPs as well as their effects on inflammatory cytokine production were evaluated. ZnO NPs were prepared using a wet chemical method. Then, the surfaces of these NPs were modified using 3-aminopropyltriethoxysilane (APTES) and dimethyl sulfoxide (DMSO) as modifying agents via a chemical hydrolysis method. According to infrared spectroscopy analysis (FTIR), the structure of the ZnO remained unchanged after modification. Antibacterial assays demonstrated that APTES modification is more effective at inducing an antimicrobial effect against Gram-negative bacteria than against Gram-positive bacteria. Cytotoxicity studies showed that cell viability was dose-dependent; moreover, pristine and APTES-modified ZnO exhibited low cytotoxicity, whereas DMSO-modified ZnO exhibited toxicity even at a low NP concentration. An investigation of inflammatory cytokine production demonstrated that the extent of stimulation was related to the ZnO NP concentration but not to the surface modification, except for IFN-γ and IL-10, which were not detected even at high NP concentrations.

Flour from Prosopis alba cotyledons: A natural source of nutrient and bioactive phytochemicals.

The Prosopis alba seed is a waste material in the process to produce pod flour. To suggest a potential use of these seeds it is necessary to determine the nutritional, phytochemical and functional quality of cotyledon flour from Prosopis alba. This flour showed high level of proteins (62%), low content of total carbohydrate and fat. Free polyphenol (1150±20mg GAE/100g flour) and carotenoids (10.55±0.05mg ß-CE/100g flour) compounds were the dominant compounds. The main identified constituents in the polyphenolic extracts were C- glycosyl flavones, including schaftoside, isoschaftoside, vicenin II, vitexin and isovitexin. The extract enriched in polyphenolic compounds exhibited ABTS(+) reducing capacity and scavenging activity of H2O2; and was able to inhibit phospholipase, lipoxygenase and cyclooxygenase, three pro-inflammatory enzymes. According to our results, the P. alba cotyledon flour could be considered as a new alternative in the formulation of functional foods or food supplements.

Preeclampsia y enfermedad cardiovascular: un enfoque integral para detectar las fases subclínicas de complicaciones obstétricas y cardiovasculares / Preeclampsia and cardiovascular disease: an integrated approach to detect the subclinical stages of obstetrical and cardiovascular complications

Desde 1995 hasta la fecha la asociación entre patologías derivadas los embarazos hipertensivos y las enfermedades cardiovasculares ha generado un gran volumen de potentes evidencias epidemiológicas y clínicas. Los propósitos de esta revisión son varios. Mostrar la consistencia y magnitud de la evidencia científica. Integrar los riesgos/enfermedades cardiovasculares y los problemas obstétricos a través de la disfunción endotelial. Preconizar el seguimiento postparto de la hipertensa embarazada, como una ventana de oportunidad para beneficiar la salud de las mujeres y sus hijos. Incluir la historia obstétrica como factor de riesgo de enfermedad coronaria. Proponer cuestionarios adaptables a las prácticas locales para facilitar la pronta incorporación de los índices de riesgo obstétrico y cardiovascular en dos etapas de la vida de una mujer. Ha llegado el momento para que los equipos obstétricos, cardiológicos y las pacientes jueguen un rol en la prevención de los riesgos y enfermedades cardiovasculares.

From 1995 onwards the association between hypertensive pregnancies and cardiovascular disease has generated a great volume of epidemiologic and clinical evidence. The purposes of this review are several. To demonstrate the consistence and weight of the scientific evidence. To integrate cardiovascular risks/diseases and obstetric complications through the link of endothelial dysfunction. To advocate postpartum follow-up after a hypertensive pregnancy as a window of opportunity to benefit the health of mothers and offsprings. To include the obstetrical history as a risk factor for coronary disease. To propose questionnaires adaptable to local practices to incorporate cardiovascular and obstetrical indexes in two stages of a woman's lifetime. The time has come for obstetrical teams, cardiologists and patients to play a preventive role regarding cardiovascular risks and diseases.

Caracterización de los pacientes con tinnitus y hallazgos audiométricos

Resumen Introducción: El tinnitus se define como la percepción consciente de un sonido, en ausencia de un estímulo acústico externo correspondiente. Se ha relacionado a múltiples comorbilidades como hipertensión arterial (HTA), diabetes mellitus (DM) e hipoacusia, sin evidencia sólida en la actualidad. Hay diversas formas de experimentar el tinnitus, ya sea de comienzo unilateral o bilateral, intermitente o persistente, con deterioro de la calidad de vida, leve hasta formas invalidantes. El conocer las diversas patologías presentes en el tinnitus, en especial la hipoacusia, toma relevancia al momento de enfrentar a pacientes con dicha patología. Objetivo: Caracterizar el tinnitus y sus principales hallazgos audiométricos en pacientes atendidos en el Servicio de Otorrinolaringología del Hospital Clínico Herminda Martín de Chillán, Chile. Material y Método: Estudio retrospectivo. Se incluyeron pacientes mayores de 18 años con diagnóstico de tinnitus entre los años 2015-2017. Se obtuvo información epidemiológica, comorbilidades, presentación clínica del tinnitus en función de lateralidad y frecuencia, hipoacusia asociada y hallazgos audiométricos. Resultados: Se incluyeron en el estudio a 249 pacientes, la mayoría mujeres (70%) con una edad promedio de inicio de su tinnitus entre 60-79 años (52%). Entre las principales comorbilidades se encuentran la hipertensión arterial, diabetes mellitus y patologías autoinmunes; los síntomas otorrinolaringológicos acompañantes estuvieron en menos del 10% de los casos. En relación a la caracterización del tinnitus, el 52% fue de inicio unilateral y el 66% de forma continua. La hipoacusia objetivada en el audiograma estuvo presente en el 43% de los pacientes con tinnitus. Conclusión: El tinnitus es una patología compleja y multifactorial, en este sentido, la presencia de hipoacusia objetiva en la audiometría estuvo presente en un 43% de los pacientes, siendo una de las principales causas a descartar por el médico en el primer enfrentamiento del paciente.

Abstract Introduction: tinnitus is defined as the conscious perception of a sound, in the absence of a corresponding external acoustic stimulus. It has been related to multiple comorbidities such as high blood pressure, diabetes mellitus, hearing loss, with no solid evidence at present. There are various ways to experience tinnitus, whether it is unilateral or bilateral, intermittent or persistent onset, from mild quality of life deterioration to disabling forms. Knowing the various pathologies present in tinnitus, especially hearing loss, becomes relevant when confronting patients with this pathology. Aim: To characterize tinnitus and its main audiometric findings in patients treated at the Otorhinolaryngology Service of the Herminda Martin of Chillán Clinical Hospital in Chile. Material and Method: Retrospective study. Patients older than 18 years with a diagnosis of tinnitus between the years 2015-2017 were included. Epidemiological information, comorbidities, clinical presentation of tinnitus according to laterality and frequency, associated hearing loss and audiometric findings were obtained. Results: 249 patients were included. Most were women (70%), with an onset average age of tinnitus between 60 to 79 years (52%). The accompanying otorhinolaryngological symptoms were in less than 10% of the cases. The main comorbidities were high blood pressure, diabetes mellitus and autoimmune pathologies. 52% of tinnitus was unilateral presentation and in 66% it was continuous. 43% had hypoacusis objectified on the audiogram, regardless of whether they had the sensation of hearing loss. Conclusion: Tinnitus is a complex and multifactorial pathology, in this sense, the presence of objective hearing loss in audiometry was present in 43% of patients, being one of the main causes to be ruled out by the doctor in the patient's first confrontation.

Specific EEG frequencies at specific brain areas and performance.

In this study it was shown that in adults, the frequency characteristics of EEG preceding stimuli that were followed by incorrect responses were different from the characteristics of EEG preceding stimuli that were followed by correct responses. In the recording during three different tasks that explore different neuronal networks, higher values of current preceding incorrect performance in those areas directly related to the task were found in frequencies within the delta (1.56 and 3.12 Hz) and beta bands (13.26, 14.04, 14.82, 15.6, 17.16 and 17.94 Hz), suggesting that these frequencies signal inhibition. Frequencies within the alpha band (9.36 and 12.48 Hz) showed greater energy preceding correct responses in task-specific areas, supporting previous results observed in children.

Effect of policosanol on experimental thrombosis models.

Policosanol is a natural product, obtained from sugar cane wax (Saccharum officinarum L.) with which cholesterol-lowering effects have been demonstrated in experimental models, healthy volunteers and hypercholesterolemic patients. The effects of policosanol on experimental venous and arterial thrombosis in rats were investigated. Policosanol (25 mg/kg) significantly decreased the thrombus weight, in the venous thrombosis models, the protective effect persisting until 4 h after its oral administration. Policosanol (25 mg/kg single dose) was able to reduce rectal temperature variation induced by arterial thrombosis. Also at the same dose policosanol increased 6-keto-PGF1 alpha serum levels in rats.