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La pandemia por COVID-19 expuso a los trabajadores de salud a una enorme exigencia y presión en su labor cotidiana. Objetivo: Evaluar el nivel de depresión, ansiedad y estrés en trabajadores de salud durante la pandemia por COVID-19 y su asociación con características personales, laborales,sentimientos, experiencias y conductas relacionadas a la pandemia. Materiales y métodos: Estudio analítico de corte transversal. Durante el mes de junio del 2020 se enviaron formularios vía e-mail y redes sociales a trabajadores de la salud del sector público de La Plata y Gran La Plata. Se evaluó el nivel de depresión, ansiedad, y estrés mediante el cuestionario DASS-21. Se relevaron variables personales, laborales, sentimientos, experiencias y conductas vinculados a la pandemia. Se analizó la asociación entre las características de los trabajadores y la presencia de síntomas psicológicos mencionados. Resultados: Participaron 515 trabajadores, 41 años (33;50), 83,3% femenino. El síntoma psicológico más frecuente fue el estrés (58,2 %), seguido por ansiedad (33,1%) y depresión (24,7%). Se hallaron mayores chances de presentar estos síntomas en trabajadores que percibieron sentimientos, experiencias y conductas negativas vinculados a la pandemia. Los trabajadores de enfermería y administración, y aquellos que convivían con personas de riesgo tuvieron mayores chances de presentar ansiedad. Conclusión: Los trabajadores de salud de La Plata y Gran La Plata presentaron diversos grados de depresión, ansiedad y estrés que se asocian a sentimientos negativos relacionados con la pandemia
The COVID-19 pandemic exposed health workers to enormous demands and pressure in their daily work. Objective: To evaluate the level of anxiety, depression and stress in health workers during the COVID-19 pandemic and its association with personal and work characteristics, feelings, experiences, and behaviors related to the pandemic. Materials and methods: Cross-sectional analytical study. During the month of June 2020, forms were sent via e-mail and social networks to health workers in the public sector of La Plata and Gran La Plata. The level of depression, anxiety, and stress was evaluated using the DASS-21 questionnaire. Personal and work variables, feelings, experiences and behaviors linked to the pandemic were surveyed. The association between the characteristics of the workers and the presence of the aforementioned psychological symptoms was analyzed. Results: 515 workers participated, 41 years old (33;50), 83.3% female. The most frequent psychological symptom was stress (58.2%), followed by anxiety (33.1%) and depression (24.7%). Greater chances of presenting these symptoms were found in workers who perceived negative feelings, experiences and behaviors linked to the pandemic. Nursing and administration workers, and those who lived with people at risk had a higher chance of presenting anxiety. Conclusion: Health workers from La Plata and Gran La Plata presented varying degrees of depression, anxiety, and stress that are associated with negative feelings related to the pandemic
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Ansiedad , Personal de Salud , DepresiónRESUMEN
Introducción: El puerperio es una etapa determinante para la mujer, sin embargo la atención está focalizada en el recién nacido. Objetivo: Describir las características gineco-obstétricas, nutricionales y clínico-metabólicas de mujeres durante el posparto que asisten al consultorio materno del Instituto de Desarrollo e Investigaciones Pediátricas. Población y Métodos: Se realizó un análisis retrospectivo de las historias clínicas de mujeres que realizaron su primer control entre los 3 y 6 meses posparto en un consultorio materno de un hospital público entre junio 2018 y diciembre 2019. Se analizaron variables sociodemográficas, gineco-obstétricas, nutricionales y clínico-metabólicas. Resultados: Participaron 211 mujeres, edad 26 (21; 31) años, 41,7 % oriundas de países limítrofes. 38,8 % tuvo un embarazo durante la adolescencia, 38,7 % de los partos fue por cesárea y 21,3 % refirió antecedentes de aborto Más de la mitad presentaron sobrepeso-obesidad y alteraciones del perfil lipídico Conclusiones: Las mujeres asistidas durante el postparto en un hospital público presentan alta frecuencia de exceso de peso y alteraciones metabólicas así como historial de cesáreas y embarazo adolescente. El conocimiento de las problemáticas más prevalentes es clave para el diseño de estrategias de prevención e intervenciones oportunas
Introduction: The puerperium is a determining stage for women, however, attention is focused on the newborn. Objective: To describe the gyneco-obstetric, nutritional and clinical-metabolic characteristics of postpartum women who attend the IDIP maternal clinic. Population and methods: A retrospective analysis was carried out of the medical records of women who underwent their first check-up between 3 and 6 months postpartum in a maternal clinic of a public hospital between June 2018 and December 2019 Sociodemographic, gynecological, nutritional, and clinical-metabolic variables were analysed. Results: 211 women participated, age 26 (21; 31) years old, 41.7% from neighbouring countries, 38.8% had a pregnancy during adolescence, 38.7% of deliveries were by caesarean section, and 21.3% reported a history of abortion. More than half presented overweight-obesity and lipid profile alterations. Conclusions: The women assisted during the postpartum in a public hospital present a high frequency of excess weight and metabolic alterations as well as a history of caesarean sections and adolescent pregnancy. Knowledge of the most prevalent problems is key for the design of prevention strategies and timely interventions
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Humanos , Femenino , Periodo Posparto , Nutrición Materna , Salud Materna , ObesidadRESUMEN
Background: Inflammation is a condition that jeopardizes the continuity of pregnancy because it increases the secretion of chemokines that favor the migration of leukocytes from maternal and fetal circulations to the cervix, placenta, and the chorioamniotic membranes. During pregnancy, the level of prolactin (PRL) in the amniotic fluid is high; there is evidence to suggest that PRL contributes to maintain a privileged immune environment in the amniotic cavity. We test the effect of prolactin on the secretion profile of chemokines in human fetal membranes.Methods: Nine fetal membranes collected from healthy nonlabouring cesarean deliveries at term. We placed whole membrane explants in a two-chamber culture system. Choriodecidua and amniotic chambers were pretreated with 250, 500, 1000, or 4000 ng/ml of PRL for 24 h, then choriodecidua was cotreated with 500 ng/ml of lipopolysaccharide (LPS) and PRL for 24 h. We used ELISA to measure secreted levels of four chemokines (RANTES, monocyte chemoattractant protein 1 (MCP-1), MIP-1α, and IL-8) in both amnion and choriodecidua regions.Results: In comparison with basal conditions, LPS treatment induced significantly higher secretion of RANTES, MCP-1, and MIP-1α, but not of IL-8. RANTES was mainly produced by choriodecidua and cotreatment with PRL significantly decreased its LPS-induced secretion. MCP-1 was primarily produced by the amnion and its secretion was only inhibited by 4000 ng/ml of PRL. Both membrane regions produced MIP-1α, which was significantly inhibited at 1000 and 4000 ng/ml PRL concentrations. IL-8 showed no significant changes regardless of PRL concentration.Conclusion: PRL inhibits the differential secretion of proinflammatory chemokines by human fetal membranes.
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Membranas Extraembrionarias , Lipopolisacáridos , Prolactina , Amnios , Quimiocinas , Femenino , Humanos , Embarazo , Prolactina/fisiologíaRESUMEN
BACKGROUND: Helicobacter pylori (H. pylori) is associated with gastroduodenal diseases. Virulence of clinical isolates is related to clinical outcome. Moreover, with microdiversity studies in clinical isolates from a single patient, but from a different origin (antrum or corpus), it is possible to demonstrate that there are simultaneous mixed infections. AIMS: To genotype H. pylori strains with multiplex PCR, according to their clinical virulence, and in this manner know the frequency of each genotype and relate it to clinical outcome in order to prevent the development of severe diseases. METHODS: A total of 210 patients with gastric alterations were studied. Virulence classification of H. pylori strains was carried out with multiplex PCR and 127 strains were identified as H. pylori by PCR (glmM and cagE). Genotype and clinical outcome were evaluated with the Fisher's exact test. In addition, RAPD-PCR was performed as a fingerprinting method to analyze mixed infections. RESULTS: The cagA, vacAs1, and vacAm1 genes were detected in all the clinical isolates. Strains were classified as: type i, 40.15% (51/127); type ii, 22.04% (28/127); and type iii, 28.4% (36/127), but two new different genotypes were also detected: (1) babA2+, cagA+, vacAs1+, 6.29% (8/127) and (2) babA2+, cagA-, vacAs2/m2+, 3.14% (4/127). The cagE gene was detected in type i strains. CONCLUSIONS: The Fisher's exact test did not support a significant association between clinical outcome and genotype. The main circulating genotypes in the Mexican population studied were: cagA+, vacAs1, and vacAm1. Multiplex PCR can be used as a screening test for H. pylori strains. Furthermore, the cagE gene is a good marker for identifying cag-PAI positive strains.
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Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Factores de Virulencia/genética , Adolescente , Niño , Preescolar , ADN Bacteriano/genética , Femenino , Genotipo , Humanos , Masculino , México/epidemiología , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
INTRODUCTION: Escherichia coli is recognized as an etiological bacteria associated with chorioamnionitis and the preterm premature rupture of fetal membranes. This pathological condition induces pro-inflammatory cytokines and degradative metalloproteinases, which are considered biological markers secreted in an acute stage of infection. Heat-shock proteins (HSPs) are an important component of the innate immunity response and are found in different pathological conditions. They have not been previously measured in human fetal membranes in response to infectious conditions. We hypothesized that the choriodecidual tissue and amniotic epithelium secreted temporal and differential Hsp-60, Hsp-70, and interleukin (IL)-1ß mediated by E. coli infection. METHODS: Fetal membranes were mounted in a two-compartment culture system and infected with two passes of live E. coli at different doses (10², 104, 105, and 106 colony-forming units (CFU)/mL) and intervals of incubation (3, 6, and 24 h). The culture medium was collected, and Hsp-60, Hsp-70, and IL-1ß were assessed using the enzyme-linked immunosorbent assay (ELISA) method. RESULTS: After 3 and 6 h of infection, E. coli induced an increase in Hsp-70 secretion in the choriodecidual tissue. However, after 24 h of incubation, Hsp-70 was downregulated and we observed an increase in IL-1ß secretion. By contrast, E. coli induced a lower Hsp-60 secretion in the amnion compared to Hsp-70. DISCUSSION: Human fetal membranes responded actively to E. coli infection, with an increase in Hsp-70 during the first hours of infection. After 24 h, there was an increase in the liberation of IL-1ß.
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Escherichia coli/inmunología , Membranas Extraembrionarias/metabolismo , Membranas Extraembrionarias/microbiología , Proteínas del Choque Térmico HSP110/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Interleucina-1beta/metabolismo , Regulación hacia Arriba , Amnios/inmunología , Amnios/metabolismo , Amnios/microbiología , Chaperonina 60/metabolismo , Corioamnionitis/inmunología , Corioamnionitis/metabolismo , Corioamnionitis/microbiología , Corion/inmunología , Corion/metabolismo , Corion/microbiología , Decidua/inmunología , Decidua/metabolismo , Decidua/microbiología , Regulación hacia Abajo , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/inmunología , Infecciones por Escherichia coli/metabolismo , Infecciones por Escherichia coli/microbiología , Membranas Extraembrionarias/inmunología , Femenino , Humanos , Inmunidad Innata , Cinética , Proteínas Mitocondriales/metabolismo , Embarazo , Técnicas de Cultivo de TejidosRESUMEN
In this paper a 3D morphological composition of transformations for brain extraction on brain Magnetic Resonance Images T1 (MRI T1) is presented. The proposal makes use of two morphological connected transformations, the lower leveling and a family of the viscous alternating sequential filters (VASFs). The properties of these operators -which consist in the control of the reconstruction process of a marker into the original image-, are exploited to segment the brain in 20 volumes of MRI T1. The segmented brains are compared with respect to: i) the segmentations obtained from BET which is popular among the scientific community for segmenting the brain; and ii) manual segmentations. The computed indices indicate that the proposed transformation produces good results during its performance. The consumed time for the algorithm during the execution is acceptable and it can be implemented in Matlab.
En este artículo se presenta una composición de transformaciones morfológicas para la extracción del cerebro en imágenes de resonancia magnética T1 (MRI T1) en 3D. La propuesta hace uso de dos transformaciones morfológicas conexas, la nivelación inferior y una familia de filtros viscosos alternados secuenciales (VASFs). Las propiedades de estos operadores- las cuales consisten en el control del proceso de reconstrucción de un marcador dentro de la imagen original-, se explotan para segmentar el cerebro de 20 volúmenes de MRI T1. Los cerebros segmentados se comparan respecto a: i) segmentaciones obtenidas a partir del algoritmo BET, el cual es popular en la comunidad científica para la segmentación del cerebro; y ii) segmentaciones manuales. Los índices calculados indican que la transformación propuesta produce buenos resultados en su desempeño. El tiempo empleado por el operador durante su ejecución es aceptable además de que la propuesta puede ser implementada en Matlab.
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Mexico is a center of domestication and diversification of tomatoes, with various landrace cultivated populations and wild varieties, but the documentation is poor in terms of their physical, chemical and nutritional characteristics. Thirteen accessions were collected and then sown and transplanted in greenhouse conditions under a randomized complete block design with four replications. This process was performed in order to evaluate the lycopene content, ascorbic acid and other physicochemical characteristics, as well as the effect of storage conditions on lycopene loss of a sample of tomato fruits native from different regions of Mexico. The analysis of variance shows significant differences (P < 0.05) among accessions for titratable acidity, pH, lycopene on wet and dry basis, in the CIE chromaticity coordinates L*, a* b*, and in the maturity index. GTO-11, OAX-115, PH-102 and PH-96 accessions stood out for their lycopene content on wet and dry basis with values above 20 and 300 mg 100 g-1, respectively. Lycopene content in samples of ground tomato fruits decreased after storing them at -20ºC; it also decreased in the scalded samples immersed in boiling water.
México es un centro de domesticación y diversificación del tomate con diversas poblaciones nativas cultivadas y variantes silvestres, pero poco documentadas en términos de sus características físicas, químicas y nutricionales. Con el objetivo de evaluar el contenido de licopeno, ácido ascórbico y otras características fisicoquímicas de los frutos de una muestra de tomate originaria de diferentes regionesde México, y evaluar el efecto de almacenamiento sobre la pérdida de licopeno, se hizo una colecta yposteriormente la siembra y trasplante en invernadero de trece accesiones bajo un diseño de bloques completos al azar con cuatro repeticiones. El análisis de varianza detecta diferencias significativas(P < 0.05) entre accesiones para acidez titulable, pH, licopeno en base húmeda y seca, en las coordenadas cromáticas CIE L*, a* y b*, y en el índice de madurez. Las accesiones GTO-11, OAX-115, PH-102 y PH-96 sobresalen en contenido de licopeno en base húmeda y seca con valores mayores a 20 y 300 mg 100 g-1, respectivamente. El contenido de licopeno en muestras molidas de frutos de tomate y almacenadas a -20ºC, decreció a medida que se incrementó el tiempo de almacenamiento, aún en las muestras escaldadas, inmersión en agua en ebullición.
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Solanum lycopersicum , Ácido AscórbicoRESUMEN
This phantom study simulates contrast-medium-enhanced digital subtraction mammography (CEDM) and compares subtracted image quality and total mean glandular dose for two alternative spectral combinations available in a GE Senographe DS mammography unit. The first choice takes advantage of large iodine attenuation at low photon energies and uses traditionally available spectra (anode/filter combinations Mo/Mo at 25 kV and Rh/Rh at 40 kV, "Mo25-Rh40"). The second choice, selected from a previous analytical optimization, includes harder spectra obtained by adding external filtration to traditional beams (Rh/Rh at 34 kV and Rh/Rh+5 mm of Al at 45 kV, "Rh34-Rh45H"). Individual images of a custom-made phantom containing tubes of various diameters filled with water- or iodine-based contrast agent were acquired with both spectral combinations. The total breast entrance air kerma, considering subtraction of two images, was limited to 8.76 mGy (1 R). The results were compared to predictions obtained through an analytical formalism that assumes noise of stochastic origin. Individual images were evaluated and subtracted under five combinations of temporal and dual-energy modalities. Signal variance analysis in individual raw images showed important contributions of nonstochastic origin, associated with the software applied to raw images, the curved geometry, and strong attenuation of the phantom cylindrical iodine-filled tubes, causing experimental SNR to vary from 2.2 to 0.8 times the predictions from low to high values of SNR. Iodine contrast in the subtracted images was found to be mainly defined by the spectra, independent of exposure, and linearly dependent on the iodine mass thickness. The highest contrast was obtained with the combined dual-energy temporal subtraction with Rh34-Rh45H, its value was 7% larger than the highest value measured with Mo25-Rh40. As expected, temporal modalities (single and dual energy, any spectral choice) led to higher contrast-over-noise ratio (CNR) than nontemporal dual-energy subtraction, the latter being negligibly small with Mo25-Rh40. CNR for 4 mg iodine/cm2 imaged temporally in a dual-energy fashion with Rh34-Rh45H (iodine imaged at high energy) is about 1.7 times the optimum for Mo25-Rh40 (iodine imaged at low energy). Iodine thicknesses needed to fulfill Rose's criterion were 0.78 +/- 0.02 mg iodine/cm2 for Mo25-Rh40 and 0.54 +/- 0.17 mg iodine/cm2 for Rh34-Rh45H, both lower than the proposed biological concentration of iodine in breast tumors after contrast medium administration. Although similar dose levels were obtained with both spectral choices under dual-energy (temporal and nontemporal) subtraction, the dose obtained in single-energy temporal subtraction with the Mo25 spectrum was 1.2 mGy lower than the dose from the modality offering the highest CNR. In all results considered, the spectral choice Mo25-Rh40 was found to represent an interesting alternative to the use of high-energy hardened spectra for CEDM, particularly when performing dynamic studies of the contrast-agent uptake in breast lesions.
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Yodo , Mamografía/instrumentación , Intensificación de Imagen Radiográfica/instrumentación , Imagen Radiográfica por Emisión de Doble Fotón/instrumentación , Medios de Contraste , Diseño de Equipo , Análisis de Falla de Equipo , Femenino , Humanos , Mamografía/métodos , Fantasmas de Imagen , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
INTRODUCTION: Postvaricella cerebellar ataxia (PVCA) and meningoencephalitis are the most common acute neurological complications of chickenpox. The objective of this study was to describe the clinical presentation, management, and outcome of children hospitalized with PVCA in the only pediatric hospital of this developing country, where routine varicella immunization is not yet available. METHODS: We performed a retrospective chart review of children aged 1-12 years old admitted to the National Children's Hospital of Costa Rica from January 1997 to June 2004 with a diagnosis of PVCA. RESULTS: Among the 441 immunocompetent patients admitted for varicella zoster virus-associated complications during this period, 37 (8.4%) had PVCA. Twenty-four of the 37 (64.9%) patients were boys. The mean (range) age was 5 (1-10) years. The median (range) interval from rash onset to admission was 2 (1-3) days. Cerebrospinal fluid analysis was available in 22 (59.5%) patients and was normal in all. Head computed tomography showed cerebral edema in six out of 18 patients (33.3%). Intravenous acyclovir was administered to 23 patients but no significant differences in clinical manifestations or outcomes were observed in treated versus untreated patients. The mean (range) length of ataxia was 4 (1-10) days, and seven (19%) patients were still ataxic on discharge. The mean (range) length of hospital stay was 4.4 (2-11) days. Minor sequelae were documented in 13 out of 24 (54.2%) patients during follow-up visits and telephone contacts. CONCLUSIONS: PVCA is usually associated with a favorable prognosis; however, neurological sequelae can occur. The real utility of acyclovir treatment and brain imaging studies in these children remains controversial.
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Ataxia Cerebelosa/etiología , Varicela/complicaciones , Ataxia Cerebelosa/diagnóstico , Ataxia Cerebelosa/terapia , Niño , Preescolar , Costa Rica , Femenino , Humanos , Lactante , Masculino , Estudios RetrospectivosRESUMEN
Contrast-medium-enhanced digital mammography (CEDM) is an image subtraction technique which might help unmasking lesions embedded in very dense breasts. Previous works have stated the feasibility of CEDM and the imperative need of radiological optimization. This work presents an extension of a former analytical formalism to predict contrast-to-noise ratio (CNR) in subtracted mammograms. The goal is to optimize radiological parameters available in a clinical mammographic unit (x-ray tube anode/filter combination, voltage, and loading) by maximizing CNR and minimizing total mean glandular dose (D(gT)), simulating the experimental application of an iodine-based contrast medium and the image subtraction under dual-energy nontemporal, and single- or dual-energy temporal modalities. Total breast-entrance air kerma is limited to a fixed 8.76 mGy (1 R, similar to screening studies). Mathematical expressions obtained from the formalism are evaluated using computed mammographic x-ray spectra attenuated by an adipose/glandular breast containing an elongated structure filled with an iodinated solution in various concentrations. A systematic study of contrast, its associated variance, and CNR for different spectral combinations is performed, concluding in the proposal of optimum x-ray spectra. The linearity between contrast in subtracted images and iodine mass thickness is proven, including the determination of iodine visualization limits based on Rose's detection criterion. Finally, total breast-entrance air kerma is distributed between both images in various proportions in order to maximize the figure of merit CNR2/D(gT). Predicted results indicate the advantage of temporal subtraction (either single- or dual-energy modalities) with optimum parameters corresponding to high-voltage, strongly hardened Rh/Rh spectra. For temporal techniques, CNR was found to depend mostly on the energy of the iodinated image, and thus reduction in D(gT) could be achieved if the spectral energy of the noniodinated image is decreased and the breast-entrance air kerma is evenly distributed between both acquisitions. Predicted limits, in terms of iodine concentration, are found to guarantee the visualization of common clinical angiogenic concentrations in the breast.
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Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/diagnóstico , Medios de Contraste/farmacología , Mamografía/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tejido Adiposo/patología , Mama/patología , Diseño de Equipo , Femenino , Humanos , Radioisótopos de Yodo , Modelos Estadísticos , Neovascularización Patológica , Procesamiento de Señales Asistido por Computador , Técnica de Sustracción , Factores de TiempoRESUMEN
The Dieulafoy lesion is a vascular anomaly generally located in proximal stomach. and consist of the presence of an artery of heavy caliber in the submucosa and mucosa, although the definitive diagnosis is anatomopathologic, with the endoscopic examination we can obtained a high precision approach. Is a rare cause of gastrointestinal bleeding although potentially fatal etiology of gastrointestinal hemorrhage. It occurs in fewer than 2% of the episodes of acute digestive hemorrhage. The injury of duodenal Dieulafoy has been communicated in a reduced number of cases and in some of them it has needed surgical treatment. We effectively presented and treat this case of a young man diagnosed in the initial endoscopy and was treated by means of injection of adrenalin and absolute alcohol.
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Arterias/anomalías , Duodeno/irrigación sanguínea , Hemorragia Gastrointestinal/etiología , Adolescente , Humanos , Masculino , Índice de Severidad de la EnfermedadRESUMEN
Prolactin (PRL) secretion by the pituitary is under the control of dopamine. Hyperprolactinemia has been found in patients with systemic lupus erythematosus (SLE) and seems to be associated with clinical activity. T-lymphocytes express PRL and those from SLE patients appear to secrete more PRL than controls. In this study, immuno-(RIA) and bio-(BIO) assayable PRL in both serum and culture media of peripheral blood mononuclear cells (PBMNC) from SLE and control subjects were evaluated in the basal state and in response to 10 mg oral administration of metoclopramide, a dopamine receptor antagonist. Prolactin size heterogeneity in serum and culture media and PRL gene transcription in PBMNC were also studied. Basal serum RIA-PRL, BIO-PRL and the BIO/RIA ratio were similar in both groups. The serum BIO-PRL response after metoclopramide was higher than RIA-PRL in SLE, and this increment was also greater than in control subjects. PBMNC from SLE subjects secreted and produced more BIO-PRL. After metoclopramide, secretion and production of PRL increased only in PBMNC from control women and not in those from SLE patients. Our results demonstrated an increased central dopaminergic tone in SLE and suggest that lymphocyte-derived PRL might contribute to alter the functional activity of the hypothalamic dopaminergic system in SLE attempting to maintain serum PRL within a physiological range.
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Hiperprolactinemia/etiología , Lupus Eritematoso Sistémico/metabolismo , Prolactina/metabolismo , Linfocitos T/metabolismo , Adulto , Western Blotting , Antagonistas de Dopamina/administración & dosificación , Femenino , Humanos , Hiperprolactinemia/inmunología , Sistema Hipotálamo-Hipofisario/fisiopatología , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/inmunología , Metoclopramida/administración & dosificación , Prolactina/inmunología , Linfocitos T/inmunologíaRESUMEN
Between 1996 and 1998, 580 litres of milk in Mexico were surveyed for aflatoxin B(1) (AFB(1)) and its metabolite aflatoxicol (AFL), which are mutagenic and carcinogenic mycotoxins that interconvert AFB(1)-AFL-AFB(1). The seven most consumed brands from different regions of Mexico included pasteurized and ultrapasteurized milk with four different fat levels: whole fat (28-33 g l(-1)), half-skimmed (10-20 g l(-1)), light (1-4 g l(-1)) and with vegetable oil (33 g l(-1)). Aflatoxins in each sample were concentrated with total aflatoxin immunoaffinity columns and quantitated by high-performance liquid chromatography. A milk sample was considered contaminated if it contained >/=0.05 microg l(-1) AFL. Pasteurization and ultrapasteurization of milk did not control contamination with AFL, which was present in 13% of samples at >/=0.05 microg l(-1) and in 8% at >/=0.5 microg l(-1), with a range of AFL from 0 to 12.4 microg l(-1). AFB(1) was present mainly in traces (0-0.4 microg l(-1)). The safest milk in relation to AFL contamination was imported milk powder with vegetable oil. There was a significant correlation between contamination of milk with AFL and the autumn (p<0.0002); the fat content was not significant.
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Aflatoxina B1/análisis , Aflatoxinas/análisis , Carcinógenos/análisis , Leche/química , Aflatoxina M1/análisis , Animales , Grasas de la Dieta/análisis , Contaminación de Alimentos/análisis , México , Micotoxinas/análisis , Estaciones del AñoRESUMEN
Internal stochastic resonance is a phenomenon in which the coherence of a non-linear system is enhanced by the presence of a particular, non-zero level of noise generated by internal or external sources without a periodic input signal. The aim of this study was to demonstrate the experimental occurrence of internal stochastic resonance in the coherence between spinal and cortical neuronal ensembles. Simultaneous recordings of spinal and cortical evoked potentials were made in the somatosensory system of the anaesthetized cat. Evoked potentials were produced by input noise introduced in the tactile stimulation of the hindpaw skin. Coherence between the spinal and cortical evoked activity recorded during different levels of input noise was calculated. All animals showed distinct internal stochastic resonance like behavior. We found that the mean coherence was an inverted U-like function of the level of input noise with a mean coherence peak of 0.43. To our knowledge, this is the first documented evidence of such phenomenon in an in vivo preparation of the central nervous system.
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Neuronas/fisiología , Corteza Somatosensorial/fisiología , Médula Espinal/fisiología , Animales , Artefactos , Gatos , Potenciales Evocados/fisiología , Miembro Posterior , Estimulación Física , Fenómenos Fisiológicos de la Piel , Procesos Estocásticos , Tacto/fisiologíaRESUMEN
Stochastic resonance (SR) is a phenomenon in which the response of a non-linear system to a weak input signal is optimized by the presence of noise. The aim of this study was to demonstrate the experimental occurrence of SR in electroencephalographic (EEG) activity elicited by mechanical tactile stimuli. Our experiments show that EEG responses evoked by mechanical tactile stimuli in the region overlying the somatosensory cortical area were optimized by the addition of certain noise amplitudes. All subjects showed distinct SR behavior. The signal-to-noise ratio (SNR) of the response evoked by mechanical indentations of the skin was an inverted U-like function of the input noise. As the noise amplitude increased, SNR values became larger. A maximum value was reached with a particular noise amplitude value. Beyond such peak, with higher noise amplitudes, the curve subsided gradually. To our knowledge, this is the first documented evidence that such remarkable phenomenon embodies electrical processes of the human brain. Such behavior might explain related findings described in psychophysical studies.
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Vías Aferentes/fisiología , Artefactos , Potenciales Evocados Somatosensoriales/fisiología , Mecanorreceptores/fisiología , Dinámicas no Lineales , Corteza Somatosensorial/fisiología , Tacto/fisiología , Adolescente , Adulto , Relojes Biológicos/fisiología , Electroencefalografía , Femenino , Humanos , Masculino , Conducción Nerviosa/fisiología , Estimulación Física , Transducción de Señal/fisiología , Procesos Estocásticos , Transmisión Sináptica/fisiologíaRESUMEN
Simultaneous recordings of cortical evoked potentials in the posterior sigmoid gyrus, and spontaneous negative cord dorsum potentials (CDPs) of the L6 lumbar spinal segment, were made in the anaesthetised cat. The electrodes were positioned in cortical and spinal somatosensory regions where the largest spontaneous and evoked negative potentials were detected. Evoked potentials were produced by electrical stimulation to cutaneous nerves or by mechanical stimulation of the hindpaw skin. We found that both electrically and mechanically cortical evoked potentials were facilitated during the spontaneous negative CDPs. The magnitude of such facilitation was proportional to the amplitude of the 'conditioning' spontaneous negative CDPs. This led to a high positive correlation between amplitude fluctuations of spontaneous negative CDPs and fluctuations of the cortical evoked potentials. This observation suggests that transmission of cutaneous sensory information in ascending pathways could be facilitated when dorsal horn spinal neurones are active.
Asunto(s)
Vías Aferentes/fisiología , Potenciales Evocados Somatosensoriales/fisiología , Mecanorreceptores/fisiología , Nervios Periféricos/fisiología , Células del Asta Posterior/fisiología , Corteza Somatosensorial/fisiología , Potenciales de Acción/fisiología , Animales , Gatos , Estimulación Eléctrica , Conducción Nerviosa/fisiología , Estimulación Física , Transmisión Sináptica/fisiología , Tacto/fisiologíaRESUMEN
A previous study has shown that lumbar spontaneous cord dorsum potentials (CDPs) are produced by background activity of a neuronal ensemble located in the dorsal horn. Here, the effects produced by intravenous application of the nitric oxide synthase inhibitor L-N(G)-nitro arginine (L-NOARG, 100 microg/kg) and of the nitric oxide donor 3-morpholinosydnonimine hydrochloride (SIN-1, 500 microg/kg) on spontaneous CDPs were examined. Experiments were performed on pentobarbitally anesthetized, paralyzed and spinalized cats. The amplitude of spontaneous CDPs increased after L-NOARG, however, decreased after SIN-1. These observations suggest that electrical activity of dorsal horn neurones generating spontaneous CDPs is dependent on nitric oxide production.
Asunto(s)
Potenciales de Acción/fisiología , Vías Nerviosas/enzimología , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/biosíntesis , Células del Asta Posterior/enzimología , Potenciales de Acción/efectos de los fármacos , Animales , Gatos , Inhibidores Enzimáticos/farmacología , Molsidomina/análogos & derivados , Molsidomina/farmacología , NG-Nitroarginina Metil Éster/farmacología , Inhibición Neural/efectos de los fármacos , Inhibición Neural/fisiología , Vías Nerviosas/efectos de los fármacos , Óxido Nítrico/agonistas , Óxido Nítrico/antagonistas & inhibidores , Donantes de Óxido Nítrico/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Células del Asta Posterior/efectos de los fármacosRESUMEN
The zona pellucida (ZP) is the extracellular matrix surrounding the mammalian oocyte. This matrix consists of three families called ZP1, ZP2 and ZP3. These proteins suffer several posttraductional modifications to give them different immunological and functional properties. In mice has been demonstrated the important role of ZP3 as a receptor of sperm. In the past, research in this field was limited for the difficulty to get enough biological material from different mammalian species, especially from human sources. Recently, several laboratories have expressed ZP recombinant proteins, allowing the study of the proteins under physiologic and pathophysiological conditions, giving the possibility to utilize ZP as a contraceptive target.
Asunto(s)
Proteínas del Huevo/fisiología , Glicoproteínas de Membrana/fisiología , Receptores de Superficie Celular , Zona Pelúcida/fisiología , Animales , Femenino , Humanos , Ratones , Especificidad de la Especie , Interacciones Espermatozoide-Óvulo/fisiología , Vacunas Anticonceptivas/inmunología , Glicoproteínas de la Zona PelúcidaRESUMEN
Vitamin D gained importance since the discovery of its steroid structure. Vitamin D participates in mineral homeostasis, regulation of gene expression, and cell differentiation. Recent advances in the study of the enzyme involved in the conversion of 25-hydroxyvitamin D3 into 1,25-dihydroxyvitamin D3 (calcitriol), as well as the discovery of it's hormone mechanism of action, have led to a better knowledge and understanding of vitamin D endocrine system, as well as it's implication in health and pregnancy.
Asunto(s)
Vitamina D/fisiología , 25-Hidroxivitamina D3 1-alfa-Hidroxilasa/fisiología , Animales , Calcitriol/fisiología , Calcio/metabolismo , ATPasas Transportadoras de Calcio/metabolismo , Diferenciación Celular , Modelos Animales de Enfermedad , Sistema Endocrino/fisiología , Activación Enzimática , Inducción Enzimática , Femenino , Feto/metabolismo , Regulación de la Expresión Génica , Homeostasis , Humanos , Recién Nacido , Túbulos Renales Proximales/enzimología , Masculino , Ratones , Ratones Noqueados , Minerales/metabolismo , Necesidades Nutricionales , Placenta/metabolismo , Preeclampsia/metabolismo , Embarazo , Complicaciones del Embarazo/metabolismo , Receptores de Calcitriol/fisiología , Raquitismo/metabolismo , Vitamina D/química , Deficiencia de Vitamina D/metabolismoRESUMEN
OBJECTIVE: We sought to describe if neurological damage, in terms of brain lesions, syndrome and syndrome severity led to abnormalities in the brain-stem auditory evoked potentials (BAEPs) in order to provide a profile of children that could be used as an indicator of subsequent neurological sequelae. We analyzed the BAEPs from a group of children having prior evidence of neurological damage and determined the presence of neurological sequelae when the subjects were 3 years old. METHODS: Brain-stem auditory evoked potentials (BAEPs) were carried out in a group of 154 children with perinatal neurological damage. The children were classified with neurofunctional (clinical and EEG alterations) or organic and neurofunctional brain disease (clinical, EEG and image alteration) and were all followed from the first month of life and serially for 3 years. We used principal component analysis (PCA), clustered analysis and linear correlation to determine association between BAEPs, risk factors and future sequelae. RESULTS: Latencies of BAEPs decreased significantly with age, and the time of conduction was modified by the presence of neurological damage. All statistical analyses suggested positive and significant associations between risk factors (trophism and condition at birth), and the latencies of waves I, III and V as well as with IPL III-V (interpeak latency) and I-V. PCA showed that IPL I-III was also positively associated with condition at birth, severity of the neurological syndrome and encephalopathy. In addition, we found that the presence and type of sequela reflected changes in the latencies of the waves, as well as IPLs, primarily those of IPL I-III. CONCLUSIONS: Our results suggest that statistical methods are often needed to analyze neurological damage. The relation between BAEPs, risk factors and neurological sequelae allowed us to obtain a profile of children, which can be then used as an aid in the prognosis of children having a risk of developing neurological sequelae.