Leak and Scattering Assessment by Optically Stimulated Luminescence Dosimetry in a Helical Linear Accelerator / Valoración de Fuga y Dispersión por medio de Dosimetría de Luminiscencia Estimulada Ópticamente (OSL) en un Acelerador Lineal Helicoidal

Radiation absorbed doses to organs outside the radiation therapy treatment beam can be significant and therefore of clinical interest. Two sets of out-of-beam measurements were performed measuring the leak dose and the scattered dose, at 5 points within the accelerator components (accelerator tube and collimator) and at 21 points on the equipment and surroundings based on a positioning scheme. For this purpose, 52 Optically Stimulated Luminescence (OSL) dosimeters were used in a latest generation helical linear accelerator. Of the 200 cGy fired at a cheese-like phantom, 0.332% of the out-of-beam dose contribution was found to come from the leak and 0.784% was transformed into scattering. For these dose values, estimates of the risk of second tumors in long-term survivors indicate a reduced probability of acquiring a second secondary radiation malignancy, based on information from the 1990 BEIR Committee report.

La dosis absorbida de radiación a órganos fuera del haz de tratamiento de radioterapia puede ser significativa y, por lo tanto, de interés clínico. Se realizaron dos sets de mediciones fuera del haz para determinar la dosis de fuga y la dosis dispersa, en 5 puntos dentro de los componentes del acelerador (tubo de aceleración y colimador) y 21 puntos en el equipo y alrededores basado en un esquema de posicionamiento. Para este fin se utilizaron 52 dosímetros de luminiscencia estimulada ópticamente (OSL, Optically Stimulated Luminescence), en un acelerador lineal helicoidal de última generación. De los 200 cGy disparados a un maniquí tipo queso, se encontró que el 0.332% de la contribución de dosis fuera del haz provenía de la fuga y 0.784% se transforma en dispersión. Para estos valores de dosis, las estimaciones del riesgo de segundos tumores en los supervivientes a largo plazo indican una reducida probabilidad de contraer una segunda malignidad por radiación secundaria, según la información del informe del Comité BEIR de 1990.

Efecto del ácido alfa lipoico sobre la peroxidación no enzimática en mitocondrias de corazón y cerebro de rata / Effect of alpha-lipoic acid against non-enzymatic peroxidation of rat heart and brain mitochondria

RESUMEN El ácido alfa lipoico (AAL) ha sido caracterizado como un antioxidante eficiente. Se ha propuesto como un agente terapéutico potencial en el tratamiento o prevención de diferentes alteraciones que pueden estar relacionadas con un desequilibrio del estado celular oxidoreductor. El objetivo de este trabajo fue analizar la sensibilidad a la peroxidación no enzimática (PNE) (ascorbato-Fe++ dependiente) en mitocondrias de corazón y cerebro de ratas incubadas con una solución de AAL. La PNE fue evaluada por el método de quimioluminiscencia (QL). Cuando se compararon las muestras control (sin el agregado del ascorbato-Fe++) con las muestras ascorbato-Fe++ dependientes, se observó un incremento significativo en la emisión lumínica. Simultáneamente, se incubaron las mitocondrias de ambos órganos con diferentes concentraciones de AAL (0,05, 0,15 y 0,25 mg/ml) observándose una protección diferencial. Las mitocondrias de cerebro de rata incubadas con dosis de 0,15 y 0,25 mg/ml de AAL fueron protegidas de los efectos de la PNE, mientras que, en las mitocondrias cardíacas, solo se observó protección con la dosis más alta de AAL (0,25 mg/ml). El análisis de QL indicó que las mitocondrias de cerebro fueron protegidas de manera más eficiente que las mitocondrias de corazón de rata. En este último caso, será necesario probar nuevas dosis de AAL para demostrar los efectos en estas membranas. En conclusión, AAL actuó como un antioxidante protector de las membranas de ambos órganos contra el daño peroxidativo.

ABSTRACT Alphalipoc acid (ALA) has been characterized as an efficient antioxidant. It has been proposed as a potential therapeutic agent in the treatment or prevention of different pathologies that may be related to an imbalance of the oxido reductive cell state. The objective of this work was to analyze the sensitivity to non-enzymatic peroxidation (NEP) (ascorbate-Fe++ dependent) in heart and brain mitochondria of rats incubated with an ALA solution. NEP was evaluated by the chemiluminescence method (CL). When the control samples (without the addition of ascorbate-Fe++) were compared with the ascorbate-Fe++ dependent samples, a significant increase in the light emission. Simultaneously, the mitochondria of both organs were incubated with different concentrations of ALA (0.05, 0,15 and 0,25 mg/ml), observing a differential protection. Rat brain mitochondria incubated with doses of 0.15 and 0,25 mg/ml of ALA were protected from the effects of NEP, while in cardiac mitochondria, protection was only observed with the highest dose of ALA (0,25 mg/ml). The CL analysis indicated that rat brain mitochondria were protected more efficiently than rat heart mitochondria. In the latter case, it will be necessary to test new doses of ALA to demonstrate the effects on these membranes. In conclusion, ALA acted as a protective antioxidant of the membranes of both organs against peroxidative damage.

Simple synthesis of photoluminescent carbon dots from a marine polysaccharide found in shark cartilage

BACKGROUND: For more than a decade, water-soluble, eco-friendly, biocompatible, and low-toxicity fluorescent nanomaterials have received considerable attention for their numerous in vivo and in vitro applications in biomedical imaging, disease diagnostics, and environmental monitoring. Owing to their tunable photoluminescence properties, carbon-based luminescent nanomaterials have shown great potential in bioimaging, photocatalysis, and biosensing among other applications. RESULTS: Marine environments provide excellent resources for the fabrication of these nanomaterials, because many marine organisms contain interesting trigger organic compounds that can be used as precursors. Herein, we synthesize multi-color emissive carbon dots (CDs) with an intrinsic photoluminescence quantum yield of 20.46%. These nanostructures were achieved through the one-step hydrothermal treatment of marine polysaccharide chondroitin sulfate, obtained from shark cartilage, in aqueous solution. CONCLUSIONS: We successfully demonstrate the low toxicity of our marine resource-derived CDs in zebrafish, and provide an initial assessment of their possible use as a bioimaging agent. Notably, the newly synthesized CDs localize in the intestines of zebrafish larvae, thereby indicating their biocompatibility and potential use as in vivo dyes.

Dosagem sérica do marcador tumoral CA 15. 3 em cadelas portadoras de neoplasias mamárias pelo método de eletroquimioluminescência / Serum dosage of the tumor marker Ca 15. 3 in bitches presenting mammary neoplasia with the chemiluminescence method

The objective of the present study was to analyze the serum levels of the tumor marker Ca15.3 in healthy bitches and those with mammary neoplasms, correlating results with tumor type, clinical staging, time until presentation, and presence of ulceration and vascularization. For the study, 30 bitches with mammary tumors and 30 healthy bitches (control group) were selected. Histopathology was performed for identification of tumor type, and blood was collected for measurement of serum concentration of the marker via the chemiluminescence method using a commercial kit. A higher frequency of malignant neoplasms was observed (76.7%), with a higher quantity of carcinoma in mixed tumor (26.7%). Regarding serum concentration of the marker Ca15.3, there was no difference in serum values when comparing the means from bitches with neoplasia and healthy bitches, nor when comparing the other characteristics. The majority of results for serum concentration of Ca15.3, whether in bitches with neoplasia or in healthy bitches, was zero. It is concluded that the measurement of the marker Ca15.3 using the chemiluminescence method and commercial kits for humans did not offer significant results that would make this method or this marker a useful tool for patient monitoring and evaluation of the prognosis of bitches with mammary neoplasms.(AU)

Medición rutinaria de calcitonina sérica en nódulos tiroideos / Routine serum calcitonin measurement in thyroid nodules

Existe mucha controversia sobre los beneficios de la medición de la calcitonina sérica (CT) durante la evaluación inicial de pacientes con nódulos tiroideos. El objetivo del estudio fue evaluar la identificación temprana del carcinoma medular de tiroides (CMT) a través de la medición rutinaria de CT sérica en una cohorte de Buenos Aires, Argentina. Se estudiaron consecutivamente a los pacientes con enfermedad nodular de la tiroides (n=1017). La CT se midió por quimioluminiscencia (valor normal: hasta 18 pg/ml en hombres y 12 pg/ml en mujeres). En dos pacientes, la hipercalcitoninemia se confirmó en mediciones repetidas. La aspiración con aguja fina con medición de CT en el líquido obtenido identificó la presencia del CMT. El estudio genético fue positivo en uno (mutación exón 14, Val804Met, CMT familiar). El otro presentó un polimorfismo (heterocigoto exón 13 L769L - heterocigoto exón 15 S904S). En ambos casos, la CT se normalizó 3 meses después de la cirugía y se mantuvo en valores normales después de 6 años de seguimiento. La medición rutinaria de la CT en nódulos tiroideos fue útil para detectar dos casos de CMT, uno de ellos esporádico y el otro familiar en la cohorte seguida. La prevalencia de CMT fue de 0.2%.

There is much controversy about the benefits of the use of serum calcitonin (CT) in the initial evaluation of patients with thyroid nodules. The objective of the study was to early identify medullary thyroid carcinoma (MTC) through the routine measurement of CT in thyroid nodular pathology in a large cohort of patients from Buenos Aires, Argentina. Consecutive patients with nodular thyroid disease (n=1017) were studied. CT was measured by chemiluminescence, normal value: up to 18 pg/ml in men and 12 pg/ml in women. In two patients, hypercalcitoninemia was confirmed in repeated measurements. Fine needle aspiration with CT measurement in the needle wash fluid identified MTC in nodules with citology abnormalities. The genetic study was positive in one patient (mutation exon 14, Val804Met, MTC familiar). The other presented a polymorphism (exon 13 L769L heterozygous - exon 15 S904S heterozygous). In both cases, CT was normalized 3 months after surgery and remained normal after 6 years of follow-up. The routine measurement of CT in thyroid nodular pathology was useful to detect two cases of MTC, one of them sporadic and the other familiar in this cohort. The prevalence of MTC was 0.2%.

Investigation and environmental analysis of samples from outbreak of toxoplasmosis at research institution in Londrina, Paraná, Brazil, 2016 / Investigação e análise ambiental de amostras oriundas de surto de toxoplasmose em uma instituição de pesquisa em Londrina, Paraná, Brasil, 2016

Abstract The objective of this study was to report an outbreak of human toxoplasmosis at a research institution in Londrina, Paraná, from December 2015 to February 2016. Blood samples from 26 symptomatic individuals were collected and the microparticle chemiluminescence immunoassay was performed to detect IgM, IgG and specific IgG avidity test in the official laboratory. A total of 20 people with symptoms and serology compatible with acute toxoplasmosis (IgM positive and IgG with low avidity) were selected as cases, while 45 asymptomatic employees working in the same teams and during the same shifts were selected as controls. All the participants of the investigation answered an epidemiological questionnaire. Three samples of water and one sludge from the institution's supply cisterns, 10 soil samples, 11 plant samples, three cat fecal samples and one domestic feline cadaver were collected for analysis of the polymerase chain reaction (PCR) for T. gondii. After analyzing the epidemiological data, the consumption of vegetables in the restaurant of the institution was the only variable associated with the occurrence of the disease. In laboratory results, all the samples showed negative results to PCR. The rapid recognition of the outbreak, early notification and investigation could have broken the chain of transmission early, thus preventing the emergence of new cases. In addition, the adoption of good food handling practices could have prevented the occurrence of the outbreak.

Resumo O objetivo deste estudo foi relatar um surto de toxoplasmose humana em uma instituição de pesquisa em Londrina, Paraná, no período de dezembro de 2015 a fevereiro de 2016. Amostras de sangue de 26 indivíduos sintomáticos foram coletadas e o imunoensaio de quimioluminescência de micropartículas foi realizado para detectar IgM, IgG e teste de avidez de IgG específica em laboratório oficial. Um total de 20 pessoas com sintomas e sorologia compatíveis com toxoplasmose aguda (IgM positiva e IgG com baixa avidez) foi selecionado como casos, enquanto 45 funcionários assintomáticos que trabalhavam nas mesmas equipes e durante os mesmos turnos foram utilizados como controles. Todos os participantes da investigação responderam a um questionário epidemiológico. Foram coletadas três amostras de água e uma de lodo das cisternas de abastecimento da instituição, 10 de solo, 11 de vegetais, três amostras de fezes de gato e um cadáver de filhote felino doméstico para detecção de T. gondii pela reação em cadeia da polimerase (PCR). Após análise dos dados epidemiológicos, o consumo de hortaliças no restaurante da instituição foi a única variável associada à ocorrência da doença. Em resultados laboratoriais, todas as amostras apresentaram resultados negativos a PCR. O rápido reconhecimento do surto, notificação e investigação prematura poderia ter quebrado a cadeia de transmissão, evitando assim o surgimento de novos casos. Além disso, a adoção de boas práticas de manipulação de alimentos poderia ter impedido a ocorrência do surto.

Assessing endocrine and immune parameters in human immunodeficiency virus-infected patients before and after the immune reconstitution inflammatory syndrome

ABSTRACT Objective The present study compares immune and endocrine parameters between HIV-infected patients who underwent the Immune Reconstitution Inflammatory Syndrome (IRIS-P) during antiretroviral therapy (ART) and HIV-patients who did not undergo the syndrome (non-IRIS-P). Materials and methods Blood samples were obtained from 31 HIV-infected patients (15 IRIS-P and 16 non-IRIS-P) before ART (BT) and 48 ± 2 weeks after treatment initiation (AT). Plasma Interleukin-6 (IL-6) and Interleukin-18 (IL-18) were determined by ELISA. Cortisol, dehydroepiandrosterone sulfate (DHEA-S) and thyroxin concentrations were measured using chemiluminescence immune methods. Results Concentrations of IL-6 (7.9 ± 1.9 pg/mL) and IL-18 (951.5 ± 233.0 pg/mL) were significantly higher (p < 0.05) in IRIS-P than in non-IRIS-P (3.9 ± 1.0 pg/mL and 461.0 ± 84.4 pg/mL, respectively) BT. Mean T4 plasma level significantly decreased in both groups of patients after treatment (p < 0.05). In both groups cortisol levels were similar before and after ART (p > 0.05). Levels of DHEA-S in IRIS-P decreased AT (1080.5 ± 124.2 vs. 782.5 ± 123.8 ng/mL, p < 0.05) and they were significantly lower than in non-IRIS-P (782.5 ± 123.8 vs. 1203.7 ± 144.0 ng/mL, p < 0.05). IRIS-P showed higher values of IL-6 and IL-18 BT and lower levels of DHEA-S AT than in non-IRIS-P. Conclusion These parameters could contribute to differentiate IRIS-P from non-IRIS-P. The significant decrease in DHEA-S levels in IRIS-P after ART might suggest a different adrenal response in these patients, which may reflect the severity of the disease.

Brazilian Bioluminescent Beetles: Reflections on Catching Glimpses of Light in the Atlantic Forest and Cerrado

ABSTRACT Bioluminescence - visible and cold light emission by living organisms - is a worldwide phenomenon, reported in terrestrial and marine environments since ancient times. Light emission from microorganisms, fungi, plants and animals may have arisen as an evolutionary response against oxygen toxicity and was appropriated for sexual attraction, predation, aposematism, and camouflage. Light emission results from the oxidation of a substrate, luciferin, by molecular oxygen, catalyzed by a luciferase, producing oxyluciferin in the excited singlet state, which decays to the ground state by fluorescence emission. Brazilian Atlantic forests and Cerrados are rich in luminescent beetles, which produce the same luciferin but slightly mutated luciferases, which result in distinct color emissions from green to red depending on the species. This review focuses on chemical and biological aspects of Brazilian luminescent beetles (Coleoptera) belonging to the Lampyridae (fireflies), Elateridae (click-beetles), and Phengodidae (railroad-worms) families. The ATP-dependent mechanism of bioluminescence, the role of luciferase tuning the color of light emission, the "luminous termite mounds" in Central Brazil, the cooperative roles of luciferase and superoxide dismutase against oxygen toxicity, and the hypothesis on the evolutionary origin of luciferases are highlighted. Finally, we point out analytical uses of beetle bioluminescence for biological, clinical, environmental, and industrial samples.

Oxidative stress in sepsis. Possible production of free radicals through an erythrocyte-mediated positive feedback mechanism

Abstract Background: Sepsis is an illness with a high morbidity for which no effective treatment exists. Its treatment has a high cost because it usually requires an intensive care unit and expensive antibiotics. The present study focus in the production of reactive oxygen species in the early stages of sepsis. This study aimed at investigating the production of reactive oxygen specie during the inflammatory response in patients with sepsis. Methods: Reactive oxygen specie production and insoluble myeloperoxidase obtained from fresh whole blood were measured by photon counting chemiluminescence in the blood of 18 septic patients and 12 healthy individuals. Modified red blood cells were evaluated by staining of blood smears. The production of reactive oxygen species by macrophages and polymorphonuclear leukocytes put into contact with modified red blood cells were also assessed by photon counting chemiluminescence. Results: The appearance of oxidatively modified erythrocytes, which is an evidence of oxidative stress, was supported by the detection of reactive oxygen species and insoluble myeloperoxidase in the whole blood of all septic patients. Peroxynitrite was the main reactive oxygen species found in the whole blood. Oxidatively modified erythrocytes activated phagocytic cells in vitro, leading to the considerable production of free radicals. Conclusion: It was found that sepsis led to a high oxidative stress and to extensive modification of erythrocytes. It is proposed that a positive feedback mechanism, involving the activation of circulating leukocytes by these modified erythrocytes would maintain the pro-oxidative state even after the disappearance of bacteria.

Acute but not chronic metabolic acidosis potentiates the acetylcholine-induced reduction in blood pressure: an endothelium-dependent effect

Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10). Phenylephrine (Phe) and acetylcholine (Ach) dose-response curves were performed by venous infusion with simultaneous venous and arterial blood pressure monitoring. Plasma nitrite/nitrate (NOx) was measured by chemiluminescence. The CMA group had a blood pH of 7.15±0.03, which was associated with reduced bicarbonate (13.8±0.98 mmol/L) and no change in the partial pressure of arterial carbon dioxide (PaCO2). The AMA group had a pH of 7.20±0.01, which was associated with decreases in bicarbonate (10.8±0.54 mmol/L) and PaCO2 (47.8±2.54 to 23.2±0.74 mmHg) and accompanied by hyperventilation. Phe or ACh infusion did not affect arterial or venous blood pressure in the CMA group. However, the ACh infusion decreased the arterial blood pressure (ΔBP: -28.0±2.35 mm Hg [AMA] to -4.5±2.89 mmHg [control]) in the AMA group. Plasma NOx was normal after CMA but increased after AMA (25.3±0.88 to 31.3±0.54 μM). These results indicate that AMA, but not CMA, potentiated the Ach-induced decrease in blood pressure and led to an increase in plasma NOx, reinforcing the effect of pH imbalance on vascular tone and blood pressure control.

Fontes de obtenção de medicamentos para tratamento de hipertensão arterial no Brasil: análise da Pesquisa Nacional de Saúde, 2013 / Sources for obtaining drugs for hypertension in Brazil: results from the National Health Survey, 2013

RESUMO: Objetivo: Analisar as diferenças sociodemográficas dos indivíduos adultos hipertensos, em relação às fontes de obtenção de medicamentos para tratar hipertensão arterial no Brasil. Métodos: Análise secundária dos dados oriundos da Pesquisa Nacional de Saúde, 2013; os desfechos considerados nas análises foram representados pelas fontes de obtenção de medicamentos para tratar a hipertensão arterial. Resultados: Foram entrevistados 10.017 indivíduos. A grande maioria dos hipertensos em uso de medicamentos (74,0%) utiliza uma fonte única de obtenção de medicamentos 7,3% (IC95% 6,4 - 8,4) referiu obter todos os medicamentos por meio dos planos de saúde privados; 22,7% (IC95% 21,0 - 24,4) em farmácias do sistema público de saúde; 21,8% (IC95% 20,2 - 23,4) no Programa Farmácia Popular do Brasil; e 29,5% (IC95% 27,7 - 31,4) exclusivamente pelas farmácias comerciais. A obtenção no sistema público de saúde como fonte única diminuiu com o avanço da idade, apresentou-se menor nas pessoas de cor da pele branca, diminuiu fortemente com o aumento da escolaridade e evidenciou-se menor entre os residentes na região Norte do país; no Programa Farmácia Popular do Brasil, a fonte única de obtenção também foi menor para as pessoas com maior escolaridade. A obtenção nas farmácias comerciais esteve associada positivamente com um perfil do sexo masculino, de maior escolaridade, de idade mais elevada, tendo declarado cor da pele branca. A ocorrência de mais de uma fonte de obtenção mostrou-se associada positivamente ao aumento da idade e inversamente ao aumento da escolaridade. Conclusões: Os resultados possibilitaram identificar diferentes estratégias para obtenção de medicamentos usados no tratamento da hipertensão, de modo a explicar como são obtidos os medicamentos no país e qual o impacto das políticas públicas nesse setor.

ABSTRACT: Objective: To analyze the sociodemographic differences among adults with hypertension regarding the sources for obtaining drugs for hypertension treatment in Brazil. Methods: This is a secondary analysis of data from the National Health Survey 2013; the outcomes considered for the analysis were the sources for obtaining drugs for treating high blood pressure. Results: The great majority (74%) of patients with hypertension taking drugs use a single source for obtaining them, 7.3% (95%CI 6.4 - 8.4) reported getting all the drugs through private health plans, 22.7% (95%CI 21.0 - 24.4) by pharmacies of the public health system, 21.8% (95%CI 20.2 - 23.4) by the Popular Pharmacy Program, and about one-third (29.5%; 95%CI 27.7 - 31.4) exclusively by commercial pharmacies. Having the public health system as the single source for obtaining the drugs was found to decrease with age, was lower in white people, decreased strongly with increase in education, and was lower for residents in the North region. Exclusive obtainment through the Popular Pharmacy Program was lower for people with higher education. Obtainment in commercial pharmacies was positively associated with being male, with higher education level, being older, and having white skin color. Obtainment using more than one source was positively associated with increasing age and inversely associated with higher education levels. Conclusions: The results allowed the identification of a trajectory of patients in obtaining drugs for the treatment of hypertension, aiming at explaining how the drugs are obtained and the impact of public policies in this sector in the country.

Prevalence and factors associated with HCV infection among elderly individuals in a southern Brazilian city

Introduction Few Latin American studies have assessed the prevalence of hepatitis C virus (HCV) infection in elderly individuals, in whom the highest rates are expected. We aimed to investigate the prevalence of and factors associated with HCV infection in elderly residents in the municipality of Tubarão, Santa Catarina. Methods This cross-sectional study included 820 individuals (aged ≥ 60 years) who were selected by simple random sampling. The presence of anti-HCV antibodies was tested by chemiluminescence, and HCV RNA detection was performed for the anti-HCV-reactive subjects. Those individuals who were anti-HCV reactive but had undetectable HCV RNA levels were tested using a third-generation recombinant immunoblot assay. The variables were compared using the chi-squared test or Fisher's exact test, and those variables with p < 0.05 were included in the logistic regression model. Results The mean patient age was 68.6 years (SD 7.0 years); 39% were men, and 92% were Caucasian. Eighteen subjects were anti-HCV positive. Among these individuals, 4 were characterized as false-positives, leaving 14 (1.7%) individuals with confirmed infections for analysis. HCV infection was associated with an age older than 65 years, households with 3 or more residents and the previous transfusion of blood products. In the logistic regression analysis, the following variables were independently associated with HCV infection: households with 3 or more residents (OR 7.9, 95% CI 1.7–35.9, p = 0.008) and previous blood transfusion (OR 6.2, 95% CI 2.1–18.6, p = 0.001). Conclusions The HCV prevalence in the elderly population in the municipality of Tubarão was higher than that found in previous studies of blood donors in the same region. Although exposure to contaminated blood products remained important, other transmission routes, such as household transmission, could play a role in HCV infection. .

Distribution of bioluminescent fungi across old-growth and secondary tropical rain forest in Costa Rica

Most research on bioluminescent fungi is concentrated on their taxonomic relationships, while the basics of their natural history and ecological relationships are poorly understood. In this study, we compared the distribution of bioluminescent fungi between old-growth and secondary forest as related to four different soil types at the tropical rainforest of La Selva Biological Station in Costa Rica. The study was conducted during the wet season of 2009. Bioluminescent fungi were sought following eight different transects distributed evenly in old-growth and secondary forests across four different soil types, covering an area of 9 420m². We found fungi in four different substrates: litter, fallen branches, dead trunks, and roots, for a total of 61 samples. Correspondence analysis showed that the occurrence of fungi and soil types were related (inertia=0.21, p=0.071). We found a significant relationship between the presence of fungi and the distribution of soil types (X²=18.89, df=9, p=0.026). We found only three samples with fruiting bodies, two of which had Mycena and the other had one fungus of the order Xylariales (possibly Hypoxylon sp., Kretzschmariella sp., Xylaria sp.). Future work will concentrate on exploring other aspects of their ecology, such as their dispersal and substrate preference. This information will facilitate field identification and will foster more research on the distribution, seasonality, reproductive phenology and ecological requirements of this group of Fungi.

La mayoría de las investigaciones sobre los hongos bioluminiscentes se ha centrado en relaciones taxonómicas. Los aspectos básicos de la historia natural y relaciones ecológicas de este grupo son poco conocidos. En este estudio, comparamos la distribución de hongos bioluminiscentes entre el bosque primario y el secundario en la Estación Biológica La Selva, Costa Rica en relación con cuatro tipos de suelo. El estudio se realizó durante la estación lluviosa del 2009. Se buscaron hongos bioluminiscentes en ocho transectos distribuidos de manera uniforme en el bosque primario y secundario y en cuatro tipos de suelo, cubriendo un área de 9 420m². Se encontraron hongos en cuatro sustratos: arena, ramas caídas, troncos muertos, y raíces muertas, para un total de 61 muestras. Se encontró una relación significativa entre la presencia de hongos y la distribución de los tipos de suelo (x²=18.89, gl=9, p=0.026). Sólo se encontraron tres muestras con cuerpos fructíferos, dos de ellos del género Mycena, mientras que el otro presentaba un hongo del orden Xylariales (posiblemente Hypoxylon sp. Kretzschmariella sp. Xylaria sp.). Futuras líneas de investigación deben concentrarse en aspectos básicos de la ecología del grupo, tales como su dispersión y preferencia de sustrato. Esta información fomentará una mayor investigación sobre la distribución, la estacionalidad y fenología reproductiva, y los requerimientos ecológicos de este grupo de hongos.

Nitric oxide levels in cochlear fluids of guinea pig

PURPOSE: To describe a technique to obtain guinea pigs cochlear fluids and measure nitric oxide (NO) concentration. METHODS: Six guinea pigs were used and sacrificed. The cochlear fluids collected for measurement of NO, performed by chemiluminescence (NOA 280). RESULTS: Through the chemiluminescence was possible to analyze the concentration of NO in cochlear fluids obtained. Average levels of nitric oxide from guinea pigs was 12.55 µM. CONCLUSION: It is possible to obtain nitric oxide cochlear fluids, with this technique and nitric oxide concentration measure by chemiluminescence, a quantitative and more precise method.

Pleiotropic effects of simvastatin in physically trained ovariectomized rats

This study tested the hypothesis that simvastatin treatment can improve cardiovascular and autonomic functions and membrane lipoperoxidation, with an increased effect when applied to physically trained ovariectomized rats. Ovariectomized rats were divided into sedentary, sedentary+simvastatin and trained+simvastatin groups (n = 8 each). Exercise training was performed on a treadmill for 8 weeks and simvastatin (5 mg/kg) was administered in the last 2 weeks. Blood pressure (BP) was recorded in conscious animals. Baroreflex sensitivity was evaluated by the tachycardic and bradycardic responses to BP changes. Cardiac vagal and sympathetic effects were determined using methylatropine and propranolol. Oxidative stress was evaluated based on heart and liver lipoperoxidation using the chemiluminescence method. The simvastatin-treated groups presented reduced body weight and mean BP (trained+simvastatin = 99 ± 2 and sedentary+simvastatin = 107 ± 2 mmHg) compared to the sedentary group (122 ± 1 mmHg). Furthermore, the trained group showed lower BP and heart rate compared to the other groups. Tachycardic and bradycardic responses were enhanced in both simvastatin-treated groups. The vagal effect was increased in the trained+simvastatin group and the sympathetic effect was decreased in the sedentary+simvastatin group. Hepatic lipoperoxidation was reduced in sedentary+simvastatin (≈21%) and trained+simvastatin groups (≈57%) compared to the sedentary group. Correlation analysis involving all animals demonstrated that cardiac lipoperoxidation was negatively related to the vagal effect (r = -0.7) and positively correlated to the sympathetic effect (r = 0.7). In conclusion, improvement in cardiovascular and autonomic functions associated with a reduction of lipoperoxidation with simvastatin treatment was increased in trained ovariectomized rats.

Correlação clínico-laboratorial entre métodos de quimiluminescência (QUIA) e eletroquimioluminescência (E-QUIA) para dosagem de TSH / Clinical and laboratorial correlation between Chemiluminescence (CHL) and Eletrochemiluminescence (e-CHL) methods for determination of TSH

A tireoide é fundamental para o desenvolvimento de vários órgãos e crescimento adequado do ser humano. O TSH é o exame inicial de escolha para avaliar os transtornos tireoidianosexistentes. Devido à variabilidade de métodos torna-se importante correlacionar as dosagens de TSH. Foram comparadas cem amostras séricas obtidas em um laboratóriocomercial, cuja dosagem foi feita pelo método de eletroquimioluminescência (e-QUIA) , e, por outro método, o de quimioluminescência (QUIA), procedido em um laboratório universitário. O coeficiente de correlação encontrado foi 0,9951 e o índice Kappa foi 0,718. Apesar da excelente correlação laboratorial e a substancial associação clínica é necessária uma avaliação médica mais criteriosa dos pacientes com valores superiores a 4,20 µUI/mL quando analisados pelo método de QUIA...

Twenty-five milligrams of clomiphene citrate presents positive effect on treatment of male testosterone deficiency - a prospective study

INTRODUCTION: Male testosterone deficiency is associated with bad sexual function and quality of life (QoL). The aim of this study was to determine whether a daily dose of 25 mg clomiphene citrate (CC) is effective in stimulating the endogenous testosterone production pathway and to address the applicability of this medication as a therapeutic option for symptomatic hypogonadism. MATERIALS AND METHODS: This was a prospective study. Men with low sexual desire and testosterone levels (T) below 400 ng/dL were selected to receive CC. Blood samples were obtained to determine baseline measurements of serum T, estradiol, LH, lipid profile and fasting plasma glucose. Each patient was treated with a daily dose of 25 mg CC for at least 3 months. Patients were asked if they experienced any side effects related to the use of CC and if they experienced any improvement in their sexual profile. Paired samples T-test was utilized to analyze responses to therapy. RESULTS: Our cohort consisted of 125 men with hypogonadism and low libido. Mean age was 62 years (± 11.1 years). Serum T levels ranged from 309 ng/dL (baseline, mean value) to 642 ng/dL (3 months after CC initiation, mean value) (p < 0.001). Serum cholesterol levels ranged from 197 to 186 mg/dL (p = 0.003). There were no statistically significant differences when comparing pre and post-treatment HDL-Cholesterol, triglycerides, fasting plasma glucose and prolactin. All men reported improvements in the post-treatment QoL scores. No serious adverse events were recorded. CONCLUSIONS: The CC was effective in stimulating the endogenous production of testosterone. A lower level of total cholesterol was verified after three months of treatment. This medication should be considered as a therapeutic option for some patients with symptomatic male testosterone deficiency.

Perfil dos hormônios da tireoide em pacientes com câncer de mama em estado de menopausa / Thyroid hormone profile in breast cancer patients in postmenopause

OBJETIVO: Verificar o perfil dos hormônios tireóideos (HTs) em pacientes pós-menopausa portadoras de carcinoma de mama (CaM). SUJEITOS E MÉTODOS: Participaram 12 pacientes com CaM em estádio I ou II sem intervenções que pudessem interferir na progressão tumoral e um grupo controle com 18 pacientes em pós-menopausa sem CaM. Foram dosados os níveis séricos de anticorpo antitiroperoxidase (TPOAB), hormônio estimulante da tireoide (TSH), tiroxina livre (T4L), estradiol (E2), hormônio folículo estimulante (FSH) e hormônio luteinizante (LH) antes e após a cirurgia, e realizada a imunoistoquímica dos receptores de estrógeno (ER) e progesterona (PR). RESULTADOS: Quatro pacientes com CaM apresentaram alterações do perfil hormonal tireoidiano: dois hipertireoidismo, um hipotireoidismo e positividade TPO-AB, todas com ER e PR positivos. Os níveis de TSH dessas pacientes não foram diferentes dos níveis encontrados no grupo controle (1,89 ± 1,56 vs. 2,86 ± 3,12 mUI/mL), porém os níveis de T4L nas pacientes com CaM foram estatisticamente maiores que o controle (1,83 ± 0,57 vs. 1,10 ± 0,20 ng/dL). CONCLUSÃO: Esses resultados reforçam a necessidade de avaliação do status tireoidiano em pacientes com CaM, uma vez que, na ausência de E2, mudanças clínicas nos HTs podem atuar em vias controladas pelo E2.

OBJECTIVE: The aim of this study was to determine thyroid hormone (TH) profile in postmenopausal patients with breast cancer (BC). SUBJECTS AND METHODS: 12 CaM patients stages I or II, without interventions that could interfere with tumor progression were selected, as well as and a control group with 18 postmenopausal women without CaM. We measured serum anti-thyroperoxidase antibody (TPOAB), thyroid-stimulating hormone (TSH), free thyroxine (T4L), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), before and after surgery, besides immunohistochemistry for estrogen (ER) and progesterone (PR) receptors. RESULTS: Four patients with CaM showed changes in thyroid hormone profile: two had hyperthyroidism, one hypothyroidism, and one was positive for TPO-AB. All of them positive for ER and PR. TSH levels in breast cancer patients were not different from levels found in the control group (1.89 ± 1.56 vs. 2.86 ± 3.12 mIU/mL), but the levels of T4L in patients with CaM were statistically higher than those of the control group (1.83 ± 0.57 vs. 1.10 ± 0.20 ng/dL). CONCLUSION: These results reinforce the need for assessment of thyroid status in CaM patients, since in the absence of E2, changes in clinical HTs can act in E2-controlled processes.

Modeling radiative transfer in tropical rainforest canopies: sensitivity of simulated albedo to canopy architectural and optical parameters

This study evaluates the sensitivity of the surface albedo simulated by the Integrated Biosphere Simulator (IBIS) to a set of Amazonian tropical rainforest canopy architectural and optical parameters. The parameters tested in this study are the orientation and reflectance of the leaves of upper and lower canopies in the visible (VIS) and near-infrared (NIR) spectral bands. The results are evaluated against albedo measurements taken above the K34 site at the INPA (Instituto Nacional de Pesquisas da Amazônia) Cuieiras Biological Reserve. The sensitivity analysis indicates a strong response to the upper canopy leaves orientation (x up) and to the reflectivity in the near-infrared spectral band (rNIR,up), a smaller sensitivity to the reflectivity in the visible spectral band (rVIS,up) and no sensitivity at all to the lower canopy parameters, which is consistent with the canopy structure. The combination of parameters that minimized the Root Mean Square Error and mean relative error are Xup = 0.86, rVIS,up = 0.062 and rNIR,up = 0.275. The parameterizations performed resulted in successful simulations of tropical rainforest albedo by IBIS, indicating its potential to simulate the canopy radiative transfer for narrow spectral bands and permitting close comparison with remote sensing products.

Este estudo avalia a sensibilidade do albedo da superfície pelo Simulador Integrado da Biosfera (IBIS) a um conjunto de parâmetros que representam algumas propriedades arquitetônicas e óticas do dossel da floresta tropical Amazônica. Os parâmetros testados neste estudo são a orientação e refletância das folhas do dossel superior e inferior nas bandas espectrais do visível (VIS) e infravermelho próximo (NIR). Os resultados são avaliados contra observações feitas no sítio K34 pertencente ao Instituto Nacional de Pesquisas da Amazônia (INPA) na Reserva Biológica de Cuieiras. A análise de sensibilidade indica uma forte resposta aos parâmetros de orientação das folhas do dossel superior (x up ) e à refletância na banda do infravermelho próximo (pNIR,up), uma menor sensibilidade à refletância na banda espectral do visível (pVISup) e nenhuma sensibilidade aos parâmetros da parte inferior do dossel, o que é consistente com a estrutura do dossel. A combinação de parâmetros que minimizaram a raiz do erro quadrado médio e o erro relativo médio são Xup= 0, 86, pVISup = 0, 062 e pNIR,up = 0, 275. As parametrizações realizadas resultaram em simulações bem sucedidas do albedo de floresta tropical pelo IBIS, indicando seu potencial para simular a transferência radiativa do dossel para bandas espectrais estreitas, permitindo a comparação com produtos de sensoriamento remoto.

Simulations of tropical rainforest albedo: is canopy wetness important?

Accurate information on surface albedo is essential for climate modelling, especially for regions such as Amazonia, where the response of the regional atmospheric circulation to the changes on surface albedo is strong. Previous studies have indicated that models are still unable to correctly reproduce details of the seasonal variation of surface albedo. Therefore, it was investigated the role of canopy wetness on the simulated albedo of a tropical rainforest by modifying the IBIS canopy radiation transfer code to incorporate the effects of canopy wetness on the vegetation reflectance. In this study, simulations were run using three versions of the land surface/ecosystem model IBIS: the standard version, the same version recalibrated to fit the data of albedo on tropical rainforests and a modified version that incorporates the effects of canopy wetness on surface albedo, for three sites in the Amazon forest at hourly and monthly scales. The results demonstrated that, at the hourly time scale, the incorporation of canopy wetness on the calculations of radiative transfer substantially improves the simulations results, whereas at the monthly scale these changes do not substantially modify the simulated albedo.

A informação precisa do albedo superficial é essencial para a modelagem climática, especialmente para regiões, tais como a Amazônia, onde a resposta da circulação atmosférica regional às mudanças do albedo superficial é forte. Estudos preliminares têm indicado que os modelos ainda não são capazes de reproduzir corretamente os detalhes da variação sazonal do albedo superficial. Portanto, investigou-se o papel do molhamento foliar sobre o albedo simulado de uma floresta tropical por meio da modificação do código de transferência radiativa no dossel do IBIS para incorporar os efeitos do molhamento do dossel sobre a refletância da vegetação. Neste estudo, procederamse simulações usando três versões do modelo superfície terrestre/ ecossistema IBIS: a versão padrão, a mesma versão recalibrada para ajustar aos dados de albedo de florestas tropicais e, uma versão modificada que incorpora os efeitos do molhamento do dossel sobre o albedo superficial, para três sítios da floresta amazônica em escalas horária e mensal. Os resultados demonstraram que, em escala horária, a incorporação do molhamento do dossel sobre os cálculos de transferência radiativa melhora substancialmente os resultados simulados, enquanto que, em escala mensal, essas mudanças não modificam substancialmente o albedo simulado.