Interferón-gamma e interleucina-10 sérica en niños anémicos con deficiencia de vitamina A / Serum levels of interferon-gamma and interleukine-10 in anemic children with vitamin A deficiency

Estudios realizados en humanos y animales han mostrado que la baja ingesta de vitamina A puede provocar anemia, sin embargo, aún no se conocen los mecanismos etiopatogénicos involucrados en tal proceso, lo cual puede ser debido a las complejas interacciones de los micronutrientes entre sí y con el sistema inmune. El objetivo del presente estudio fue analizar las concentraciones séricas del Interferón gamma (IFN- g) y la Interleucina 10 (IL-10) en niños anémicos y no anémicos según el estado nutricional de la vitamina A. Para ello, se estudiaron 53 niños eutróficos (45-77 meses; F=29, M=24), procedentes de Maracaibo-Venezuela, en quienes se evaluó: la presencia de anemia mediante el análisis de la concentración de hemoglobina, según los criterios de la OMS (Hb<110g/L <60 meses, Hb<115g/L >60 meses); y el estado de la vitamina A por la técnica de Citología de Impresión Conjuntival (CIC), considerando la prueba de CIC Normal=suficiencia de vitamina A y CIC Anormal=DVA. Asimismo, fueron determinadas las concentraciones séricas de las citocinas (IFN-gamma e IL-10) en pg/mL con el método de ELISA. Los datos fueron analizados con el programa estadístico SAS/STAT, los grupos fueron comparadas aplicando ANOVA (p<0,05). En nuestros resultados la prevalencia de anemia observada fue de 75,50 por ciento; DVA 50,94 por ciento y de Anemia+DVA 35,86 por ciento. Los niños anémicos con DVA mostraron valores séricos significativamente más bajos de IFN- g e IL-10 que el resto de los grupos. Esta alteración de los complejos mecanismos regulatorios del sistema inmunitario pudiera ser un elemento responsable de los trastornos en la formación de los eritrocitos

[Serum levels of interferon-gamma and interleukine-10 in anemic children with vitamin A deficiency]. / Interferón-gamma e interleucina-l0 sérica en niños anémicos con deficiencia de vitamina A.

Studies done with human and animals have shown that the diminished vitamin A intake can produce anemia, but the ethiopathogenic mechanism hasn't been known due to the few studies about the complex interactions between micronutrients deficiencies, immune system and cytokine productions. The objective of the present study was to analyze the serum concentration of IFN-gamma and IL-10 in anemic and non anemic children according to vitamin A nutritional status. A descriptive study of 53 euthrophic children, without infectious diseases (45-77 month old; 29 girls, 24 boys), living in a slum in Maracaibo-Venezuela. Anemia was evaluated by means of blood hemoglobin concentration analysis, standard WHO criteria for anemia were Hb < 110 g/L in <60 month old children; Hb < 115 g/L in >60 month old children. Vitamin A status was assessed by Conjunctival Impression Cytology (CIC) technique, which determines Normal CIC=Control or Abnormal CIC=VAD. The serum concentration of IFN-gamma and IL-10 (pg/mL; X +/- DE), was determined by the ELISA method. Statistical significance of differences was tested by ANOVA (p < 0.05). Prevalence of anemia was 75.50%; VAD 50.94% and anemia+VAD 35.86%. The anemic children with VAD showed significant serum values of IFN-gamma e IL-10 lower than in other groups. This alteration of the complex immunoregulatory mechanism could be responsible for dysfunction eritrhoid cell formation.

Structural patterns of injured mitochondria in human oedematous cerebral cortex.

PRIMARY OBJECTIVE: Cerebral cortical biopsies of 37 patients with clinical diagnosis of congenital malformations, brain trauma and tumours were studied to establish mitochondrial morphological alterations. METHODS AND PROCEDURES: Cortical biopsies obtained in the surgical room were immediately processed by conventional technique for transmission electron microscopy. RESULTS: Three injured mitochondrial morphological patterns were found: swollen clear, (SCM), swollen dense (SDM) and dark degenerated (DDM) mitochondria. SCM were predominantly found in traumatic brain oedema. SDM and DDM were frequently observed in sustained permanent ischaemia induced by brain tumours, vascular anomaly and congenital hydrocephalus. SCM exhibited low electron dense mitochondrial matrix, enlarged intracristal space and continuity of outer and inner mitochondrial membranes. SDM showed high electron dense matrix and swollen intact or fragmented cristae. DDM displayed overall high electron density of matrix and mitochondrial membranes. CONCLUSION: The injured mitochondrial patterns are related with nerve cell death and considered markers of lethal nerve cell injury.

[Serum values of cytokines in children with vitamin A deficiency disorders]. / Valores séricos de citocinas en niños con desórdenes por deficiencia de vitamina A.

Vitamin A Deficiency Disorders (VADD) have been associated with alterations of cellular differentiation, regulatory functions of the immune system and increased children morbidity and mortality rates due to acute respiratory and intestinal infections. The aim of the present study was to determine serum concentrations of Thl-Th2 cytokines in VADD children. The sample consisted of 138 children (F=72; M=66; 4-7 y old) living in slums in Maracaibo, Venezuela, with an adequate nutrition assessed by clinics and anthropometry. Vitamin A status was assessed by the Conjunctival Impression Cytology (CIC) technique following the ICEPO methodology, which determines Normal CIC = control or Abnormal CIC = VADD. The cytokines IL-10, IL-4 and IFN-gamma (pg/mL) were analyzed by the ELISA method; and IL-2 (U/mL) by the EAISA method. The Student's t test was applied to detect differences between values (p<0.05). No one child presented clinical evidence of VADD; 71 children (51.40%) exhibited normal CIC (control), whereas 67 children (48.60%) presented abnormal CIC indicative of sub-clinical manifestation of VADD. The prevalence was higher, although non significant, in females, 5-6 y old children and amerindians (51.39%, 64.18% and 60.40%, respectively). A diminished serum concentration of IL-10 was detected in VADD children, in comparison with the control group (4.41 +/- 1.27 pg/mL vs. 6.03 +/- 3.90 pg/mL) (p<0.03). The rest of studied cytokines were not significantly different with respect to control. The IL-10 diminution in VADD children would be related to the alteration of the inflammatory response at the level of respiratory and intestinal epithelia affected by infections.

Valores séricos de citocinas en niños con desordenes por deficiencia de vitamina A / Serum values of cytokines in children with vitamin A deficiency disorders

Los desordenes por deficienica de vitamina A(DDVA)se manifiestan por trastornos de la diferenciación celular, alteración del sistema inmunológico y aumento de la tasa de morbi-mortalidad infantil debido a infecciones respiratorias y gastrointestinales. Con el objeto de conocer las concentraciones séricas de las citocinas en niños con DDVA, se estudiaron 138 niños marginales de Maracaibo (F=72; M=66; 4-7 años), con estado nutricional adecuado, determinado por clínica y antropometría. Para detectar niños con DDVA se aplicó la técnica de Citología de Impresión Conjuntival (CIC) según ICEPO, CIC normal = control y CIC anormal = DDVA. Las concentraciones séricas de las citocinas IL-10, IL-4 e IFN-gamma (pg/mL) se analizaron por el método ELISA, y la IL-2 (U/mL), por el método EAISA. Para encontrar diferencia entre los valores obtenidos se aplicó la prueba t de Student (p < 0,05). Ningún niño presentó xeroftalmia. Por la técnica de CIC, 67 niños (48,60 por ciento) presentaban anormalidad, indicativa de deficiencia funcional de vitamina A. La prevalencia de DDVA fue más alta en niños 5-6 años (64,18 por ciento), sexo femenino (51,39 por ciento), y raza indígena (60,40 por ciento), sin significancia estadística. En los niños con DDVA, la única citocna que mostró valores séricos bajos (p < 003) fue la IL-10 comparada con el grupo control (4,41 ± 1,27 pg/mL vs 6,03 ± 3,90 pg/mL): El resto de las citocinas no mostró diferencia estadística con respecto al control. La coexistencia de DDVA y valores séricos bajos de IL-10 en los niños, podría explicar la alteración de la respuesta inflamatoria a nivel de los epitelios respiratorio e intestinal

[Plasma amino acids profile of healthy pregnant adolescents in Maracaibo, Venezuela]. / Perfil de aminoácidos plasmáticos en adolescentes saludables embarazadas de Maracaibo, Venezuela.

One hundred female adolescents (13-18 y) were clinical and anthropometrically studied to select only those with adequate nutrition. Most adolescents belonged to IV socio-economic stratum families (worker class). Height, weight, age, body mass index and medial arm circumference were used as anthropometric parameters. After screening, only 41 non pregnant girls (control) and 42 pregnant girls with adequate nutrition were selected to analyze plasma amino acids. Fasting peripheral venous blood was drawn, and plasma amino acids were analyzed by HPLC. Amino acid concentrations were expressed as umol/L +/- SE. SAS/STAT program was used for statistical analysis. Amino acid values of control adolescent group were found in ranges reported by other investigators, with slight variations, mostly in diminution, presumably due to nutritional, metabolic or genetic conditions of people living in tropical regions. In pregnant healthy adolescents, distributed according to gestational age: < 32 weeks (n = 30) and > 32 weeks (n = 12), a diminution of total molar plasma amino acids was found, by comparing with control values. Ten amino acids (Pro, Gly, Gln, Arg, Ser, Orn, Tau, Leu, Thr and Val) appeared significantively diminished throughout gestation, being Gly. Gln and Arg most affected since earlier weeks. During the 2nd period. Thr and Val increased their grade of affectation; whereas some amino acids values (Orn, Pro and Tau) tended to recuperate. Several of affected amino acids are gluconegoenic, thus, they could be utilized to supply the energy required by the pregnant adolescent against her double stress: the fetus development and her own development. The plasma amino acid values reported in both, healthy non pregnant and pregnant adolescents, could be taken as regional referential profile of plasma amino acids in this poblational group for further research on adolescent and fetal--maternal malnutrition.

[Vitamin A deficiency and the anthropometric nutritional status of urban and rural marginalized children in the state of Zulia, Venezuela]. / Deficiencia de vitamina A y estado nutricional antropométrico en niños marginales urbanos y rurales en el Estado Zulia, Venezuela.

The present transversal study was carried out to estimate the prevalence of both vitamin A deficiency (VAD) and protein-energy malnutrition among children (24 to 85 months) from three urban slums (n = 173) in Maracaibo city, Zulia State, Venezuela and a rural slum area (n = 34), vieinal to Maracaibo, by measuring serum retinol and z score of anthropometric indices Height//Age (H//AZ); Weight//Age (W//AZ) and Weight//Height (W//HZ), compared to NCHS-WHO reference values. The Graffar's methodology adapted to Venezuela by Méndez Castellano (1986) confirmed the underprivileged socio-economic condition of the children population. For serum retinol analysis, peripheral venous blood was drawn and serum was treated according to the Bieri et al. (1979) technique and HPLC procedure. Values were recorded in microgram/dL. Statistical analysis was done by using Epi Info 2000, release 1.0 and SAS release 6.0 (1996) computer programs. The prevalence of VAD (serum retinol < 20 micrograms/dL) in the total children population (n = 207) was 22.2%, being higher in urban children than in rural children (22.5% vs 20.5%). No clinical signs of VAD were detected in the children. The nutritional status analysed by Z score of anthropometric indices revealed that 27.4% of children suffered from undernutrition (Z score = -2 to > -3 SD), being 15.4% stunted, 9.6% wasted and 2.6% with acute protein-energy malnutrition. Neither severe malnutrition nor overweight were detected. According with the H//AZ index, 54.6% of children had adequate nutrition. However 23% of them suffered from VAD. In children at risk of developing undernutrition (Z score = -1 to > -2 SD), 20.9% had VAD and of the stunted children, 21.9% presented VAD. With W//AZ, 60.3%, 29.9% and 9.1% of children were with adequate nutrition, at risk, or wasted respectively; of each group, 25.6%, 17.7% and 15%, respectively had serum retinol values below 20 micrograms/dL. The Z score of W//HZ indicator revealed that 87.4%, 10.4% and 2.4% of children were in good nutrition, at risk, or with acute protein-energy malnutrition, respectively. In the three groups 22.1%, 23.8% and 20%, respectively were affected by VAD. These results indicate that VAD coexists indistinctly in healthy, adequately nourished children, as in those malnourished ones. Our VAD prevalence results and others from Venezuela, are higher than the criteria laid down by WHO and PAHO which warrant wide community intervention. This public health problem becomes more significant because children are apparently healthy and, if timely vitamin A supplementation is not given, any intercurrent infection is likely to worsen the vitamin A status, increasing the widely known consequences.

Deficiencia de vitamina A y estado nutricional antropométrico en niños marginales urbanos y rurales en el Estado Zulia, Venezuela / Vitamin A deficiency and the anthropometric nutritional status of urban and rural marginalized children in the state of Zulia, Venezuela

The present transversal study was carried out to estimate the prevalence of both vitamin A deficiency (VAD) and protein-energy malnutrition among children (24 to 85 months) from three urban slums (n = 173) in Maracaibo city, Zulia State, Venezuela and a rural slum area (n = 34), vieinal to Maracaibo, by measuring serum retinol and z score of anthropometric indices Height//Age (H//AZ); Weight//Age (W//AZ) and Weight//Height (W//HZ), compared to NCHS-WHO reference values. The Graffar's methodology adapted to Venezuela by MÚndez Castellano (1986) confirmed the underprivileged socio-economic condition of the children population. For serum retinol analysis, peripheral venous blood was drawn and serum was treated according to the Bieri et al. (1979) technique and HPLC procedure. Values were recorded in microgram/dL. Statistical analysis was done by using Epi Info 2000, release 1.0 and SAS release 6.0 (1996) computer programs. The prevalence of VAD (serum retinol < 20 micrograms/dL) in the total children population (n = 207) was 22.2, being higher in urban children than in rural children (22.5 vs 20.5). No clinical signs of VAD were detected in the children. The nutritional status analysed by Z score of anthropometric indices revealed that 27.4 of children suffered from undernutrition (Z score = -2 to > -3 SD), being 15.4 stunted, 9.6 wasted and 2.6 with acute protein-energy malnutrition. Neither severe malnutrition nor overweight were detected. According with the H//AZ index, 54.6 of children had adequate nutrition. However 23 of them suffered from VAD. In children at risk of developing undernutrition (Z score = -1 to > -2 SD), 20.9 had VAD and of the stunted children, 21.9 presented VAD. With W//AZ, 60.3, 29.9 and 9.1 of children were with adequate nutrition, at risk, or wasted respectively; of each group, 25.6, 17.7 and 15, respectively had serum retinol values below 20 micrograms/dL. The Z score of W//HZ indicator revealed that 87.4, 10.4 and 2.4 of children were in good nutrition, at risk, or with acute protein-energy malnutrition, respectively. In the three groups 22.1, 23.8 and 20, respectively were affected by VAD. These results indicate that VAD coexists indistinctly in healthy, adequately nourished children, as in those malnourished ones. Our VAD prevalence results and others from Venezuela, are higher than the criteria laid down by WHO and PAHO which warrant wide community intervention. This public health problem becomes mor

Glycogen-rich and glycogen-depleted astrocytes in the oedematous human cerebral cortex associated with brain trauma, tumours and congenital malformations: an electron microscopy study.

PRIMARY OBJECTIVE: The anaerobic mobilization of astrocyte glycogen in anoxic-ischemic regions of the oedematous human cerebral cortex is analysed. METHODS AND PROCEDURES: Seventeen cortical biopsies of patients with brain trauma, brain tumours and congenital malformations were examined by conventional transmission electron microscopy. RESULTS: Glycogen-rich and glycogen-depleted, clear or dense astrocytes cell bodies were observed in anoxic ischaemic regions of different brain cortical areas in perineuronal, neuropilar and perivascular localization. Glycogen-rich astrocytes showed clear or moderately dense cytoplasm and accumulation of both beta-type or monogranular glycogen granules and alpha-type or multigranular glycogen particles. Focal regions of translucent cytoplasm were observed in areas of glycogen degradation. Glycogen-depleted astrocytes exhibited a clear cytoplasm and scarce amount or absence of beta-type glycogen granules. Coexisting glycogen-rich and glycogen-depleted neuropilar astrocytic processes were observed in the vicinity of degenerated myelinated axons and degenerated axodendritic contacts. Glycogen-rich and glycogen-depleted perivascular astrocytic processes were also found surrounding injured and collapsed cerebral capillaries. CONCLUSION: The findings suggest astrocytic glycogen mobilization during anoxic and ischaemic conditions, revealing the important contribution of astrocytes on neuronal survival under conditions of energy substrate limitations.

Confocal laser scanning, conventional scanning and transmission electron microscopy of vertebrate cerebellar granule cells

Confocal laser scanning microscopy of hamster cerebellar granular layer showed in montages of z-series the presence of small, medium and large granule cells. A granule cell Golgi cell ratio of 50/4 was observed surrounding glomerular regions. Field emission high resolution scanning electron microscopy of mouse cerebellar granular and molecular layers showed SE-I images of the outer and inner surfaces of nuclear and cytoplasmic compartments of chromium coated granule cells and the axo-spinodendritic synapses of parallel fibers with Purkinje cell dendrites. Conventional scanning electron microscopy of teleost fish cerebellar cortex showed three dimensional morphology of granule cell soma and processes and the synaptic relationship with mossy and climbing fibers, Golgi cell axonal ramifications and dendrites of stellate neurons, by means of SE-II and SE-III signal image mode, in sagittally and transversally cryofractured cerebellar cortex. SE-II images of the non-synaptic segments and synaptic varicosities of parallel fiber outer surface were characterized in the molecular layer. Ultrathin sections of transmission electron microscopy (TEM) revealed somato-somatic, dendro-somatic and dendro-dendritic like-desmosomal and like-hemidesmosomal junctions in human cerebellar granule cells. Freeze-etching replicas of mouse cerebellar cortex displayed granule cell intramembrane morphology, cytoplasmic fractured face and the Bergman glial cell cytoplasm completely surrounding the parallel fibers in the molecular layer. The mossy fiber-granule cell dendrite synaptic relationship was observed in sagittally and transversally cryofractured cerebellar cortex and correlated with TEM images. SE-II images of the climbing fiber synaptic connections with granule cell dendrites were obtained in teleost fish cerebellar cortex. One to one axo-dendritic synaptic contacts between Golgi cell axonal ramifications and granule cell dendrites were also seen. The above findings provide new vistas for future studies dealing with intracortical circuits and information processing in the cerebellar cortex.

Confocal laser scanning, conventional scanning and transmission electron microscopy of vertebrate cerebellar granule cells

Confocal laser scanning microscopy of hamster cerebellar granular layer showed in montages of z-series the presence of small, medium and large granule cells. A granule cell Golgi cell ratio of 50/4 was observed surrounding glomerular regions. Field emission high resolution scanning electron microscopy of mouse cerebellar granular and molecular layers showed SE-I images of the outer and inner surfaces of nuclear and cytoplasmic compartments of chromium coated granule cells and the axo-spinodendritic synapses of parallel fibers with Purkinje cell dendrites. Conventional scanning electron microscopy of teleost fish cerebellar cortex showed three dimensional morphology of granule cell soma and processes and the synaptic relationship with mossy and climbing fibers, Golgi cell axonal ramifications and dendrites of stellate neurons, by means of SE-II and SE-III signal image mode, in sagittally and transversally cryofractured cerebellar cortex. SE-II images of the non-synaptic segments and synaptic varicosities of parallel fiber outer surface were characterized in the molecular layer. Ultrathin sections of transmission electron microscopy (TEM) revealed somato-somatic, dendro-somatic and dendro-dendritic like-desmosomal and like-hemidesmosomal junctions in human cerebellar granule cells. Freeze-etching replicas of mouse cerebellar cortex displayed granule cell intramembrane morphology, cytoplasmic fractured face and the Bergman glial cell cytoplasm completely surrounding the parallel fibers in the molecular layer. The mossy fiber-granule cell dendrite synaptic relationship was observed in sagittally and transversally cryofractured cerebellar cortex and correlated with TEM images. SE-II images of the climbing fiber synaptic connections with granule cell dendrites were obtained in teleost fish cerebellar cortex. One to one axo-dendritic synaptic contacts between Golgi cell axonal ramifications and granule cell dendrites were also seen. The above findings provide new vistas for future studies dealing with intracortical circuits and information processing in the cerebellar cortex.(AU)

Prevalencia de deficiencia subclínica de vitamina A y desnutrición en niños marginales de Maracaibo-Venezuela / Prevalence of sub clinical vitamin A deficiency and malnutrition in slum children in Maracaibo-Venezuela

El presente estudio fue realizado para estimar la prevalencia de deficiencia de vitamina A en niños, mediante examen clínico, oftalmológico y por citología de impresión conjuntival (CIC); y el estado nutricional, analizando los indicadores antropométricos T//E, P//E y P//T. La población de estudio incluyó 157 niños, 2-6 años de edad, provenientes de barrios marginales urbanos y rurales de Maracaibo, Venezuela. La CIC se realizó de acuerdo a la técnica convencional de ICEPO. Se aplicó puntaje Z los datos antropométricos con patrón de referencia NCHS-OMS. No se detectaron signos clínicos ni oftalmológicos de deficiencia de vitamina A. La prevalencia de déficit sub clínico de vitamina A, detectada por CIC anormal, fue de 35,4 por ciento, siendo mas alta en el área rural (48,3 por ciento). Estos valores sobrepasan los límites de prevalencia establecidos por OMS/UNICEF para indicar problema de salud pública (>20 por ciento). Se detectó desnutrición global y retardo de crecimiento, ambos de leve a moderado en el 36,1 por ciento y 44,6 por ciento de los niños, respectivamente. Una respuesta alterada de CIC se observó tanto en los niños adecuadamente nutridos como en los desnutridos (=35 por ciento). No hubo diferencia significativa en la distribución de los resultados de CIC en relación al estado nutricional. Estos hallazgos indican que la prueba de CIC y la aplicación de puntaje Z a los datos antropométricos nutricionales son útiles para caracterizar el riesgo de deficiencia de vitamina A y de desnutrición en comunidades. Se recomienda implementar en dichas comunidades programas de intervención nutricional integral que incluya suplementación, fortificación de alimentos y diversificación dietaria; así como mejorar su condición socioeconómica y de salubridad, y el nivel educacional, haciendo énfasis en la educación nutricional y para la salud

Further observations on cerebellar climbing fibers. A study by means of light microscopy, confocal laser scanning microscopy and scanning and transmission electron microscopy

The intracortical pathways of climbing fibers were traced in several vertebrate cerebella using light microscopy, confocal laser scanning microscopy, scanning and transmission electron microscopy. They were identified as fine fibers up to 1(micron thick, with a characteristic crossing-over bifurcation pattern. Climbing fiber collaterals were tridimensionally visualized forming thin climbing fiber glomeruli in the granular layer. Confocal laser scanning microscopy revealed three types of collateral processes at the interface between granular and Purkinje cell layers. Scanning electron microscopy showed climbing fiber retrograde collaterals in the molecular layer. Asymmetric synaptic contacts of climbing fibers with Purkinje dendritic spines and stellate neuron dendrites were characterized by transmission electron microscopy. Correlative microscopy allowed us to obtain the basic three-dimensional morphological features of climbing fibers in several vertebrates and to show with more accuracy a higher degree of lateral collateralization of these fibers within the cerebellar cortex. The correlative microscopy approach provides new views in the cerebellar cortex information processing.

Further observations on cerebellar climbing fibers. A study by means of light microscopy, confocal laser scanning microscopy and scanning and transmission electron microscopy

The intracortical pathways of climbing fibers were traced in several vertebrate cerebella using light microscopy, confocal laser scanning microscopy, scanning and transmission electron microscopy. They were identified as fine fibers up to 1(micron thick, with a characteristic crossing-over bifurcation pattern. Climbing fiber collaterals were tridimensionally visualized forming thin climbing fiber glomeruli in the granular layer. Confocal laser scanning microscopy revealed three types of collateral processes at the interface between granular and Purkinje cell layers. Scanning electron microscopy showed climbing fiber retrograde collaterals in the molecular layer. Asymmetric synaptic contacts of climbing fibers with Purkinje dendritic spines and stellate neuron dendrites were characterized by transmission electron microscopy. Correlative microscopy allowed us to obtain the basic three-dimensional morphological features of climbing fibers in several vertebrates and to show with more accuracy a higher degree of lateral collateralization of these fibers within the cerebellar cortex. The correlative microscopy approach provides new views in the cerebellar cortex information processing.(AU)

Correlative microscopy of cerebellar Golgi cells

The cerebellar Golgi cells of mouse, teleost fish, primate and human species have been studied by means of light and Golgi light microscopic techniques, confocal laser scanning microscopy, slicing technique, ethanol-cryofracturing and freeze-fracture methods for scanning electron microscopy and ultrathin sectioning and freeze-etching replicas for transmission electron microscopy. The Golgi cells appeared in the granular layer as polygonal, stellate, round or fusiform macroneurons surrounded by the granule cell groups. They exhibited ascending dendrites toward the molecular layer and horizontal dendrites and a short beaded axonal plexus confined to the granular layer. Scanning electron microscopy revealed their three-dimensional neuronal geometry and smooth outer surfaces. Freeze-fracture method for SEM showed the stereospatial cytoplasmic arrangement of endoplasmic reticulum, cell organelles and nuclear envelope. By means of transmission electron microscopy the asymmetric synaptic connections of Golgi cell horizontal dendrites--with mossy fiber rosettes at the cerebellar glomerulus--and of Golgi cell axons--with granule cell dendrites at the periphery of glomerular region--were identified. At the molecular layer, Golgi cell ascending dendrites exhibited short neckless spines establishing asymmetric contacts with granule cell axons or parallel fibers. Shaft asymmetric axodendritic and axospinodendritic contacts between Golgi cell dendrites and climbing fibers were also found in the molecular layer.

Correlative microscopy of cerebellar Golgi cells

The cerebellar Golgi cells of mouse, teleost fish, primate and human species have been studied by means of light and Golgi light microscopic techniques, confocal laser scanning microscopy, slicing technique, ethanol-cryofracturing and freeze-fracture methods for scanning electron microscopy and ultrathin sectioning and freeze-etching replicas for transmission electron microscopy. The Golgi cells appeared in the granular layer as polygonal, stellate, round or fusiform macroneurons surrounded by the granule cell groups. They exhibited ascending dendrites toward the molecular layer and horizontal dendrites and a short beaded axonal plexus confined to the granular layer. Scanning electron microscopy revealed their three-dimensional neuronal geometry and smooth outer surfaces. Freeze-fracture method for SEM showed the stereospatial cytoplasmic arrangement of endoplasmic reticulum, cell organelles and nuclear envelope. By means of transmission electron microscopy the asymmetric synaptic connections of Golgi cell horizontal dendrites--with mossy fiber rosettes at the cerebellar glomerulus--and of Golgi cell axons--with granule cell dendrites at the periphery of glomerular region--were identified. At the molecular layer, Golgi cell ascending dendrites exhibited short neckless spines establishing asymmetric contacts with granule cell axons or parallel fibers. Shaft asymmetric axodendritic and axospinodendritic contacts between Golgi cell dendrites and climbing fibers were also found in the molecular layer.(AU)

Formulación y evaluación química-nutricional de un alimento esterilizado con base en aislado de soya: lactosuero y leche destinado a la población escolar / Formulation and nutritional evaluation of a sterilized product for scholar children based on soy isolated: whey and milk

Con el propósito de presentar una alternativa nutricional de fácil conservación y manejo para los programas sociales, se ha formulado y elaborado un alimento líquido esterilizado con base en aislado de soya, lactosuero y leche como principales fuentes proteicas. Al alimento esterilizado se le determinó la composición química, energía metabolizable, calidad microbiológica y calidad nutricional (digestibilidad y PER). Se evaluó, además, el efecto del tratamiento térmico sobre el contenido de aminoácidos esenciales del alimento líquido y su aceptabilidad y tolerancia por una población preescolar y escolar (5 a 12 años). Los resultados indican que la composición química por cada 100g del alimento es la siguiente: humedad 86,85g; pH 6,6; densidad relativa 1,044; proteína 3,26g; grasa 1,07g; carbohidratos 8,32g y cenizas 0,5g. La bebida infantil aporta 115,15 Kcal/200 mL. El recuento total de aerobios se mantuvo por debajo de los límites establecidos por las normas COVENIN. El alimento esterilizado permaneció estable durante tres meses a 25ºC. La digestibilidad aparente y PER fueron 94,45 por ciento y 2,35 respectivamente. La esterilización produjo disminución significativa de la mayoría de los aminoácidos esenciales; no obstante, el contenido de éstos en el alimento se mantuvo por encima de los requerimientos establecidos por la FAO/OMS para niños en edad escolar. La aceptabilidad y tolerancia del producto por una población escolar fue de 91,0 y 98,0 por ciento respectivamente. Se concluye que el producto elaborado, por su alto valor nutritivo, el bajo costo de sus ingredientes, su fácil manejo y distribución a temperatura ambiente y su excelente aceptabilidad y tolerancia, podría ser utilizado como complemento de la dieta diaria de la población escolar de bajos recursos

Características nutricionales de una galleta formulada con plasma sanguíneo de bovino como principal fuente proteica / Nutritional characteristics of a cookie formulated with bovine blood plasma as a main source of protein

El objetivo de este trabajo fue evaluar las características nutricionales de una galleta formulada con plasma sanguíneo de bovino como fuente principal de proteína. Se preparó una mezcla con plasmas de bovino, harina de trigo, azúcar o sal, condimentos y aceite vegetal. La mezcla fue colocada en bandejas y horneada a 120 grados Celsius durante 1 hora. Al producto final se le determinó humedad, grasa, proteína, carbohidratos, contenido calórico, cenizas, hierro, aminoácidos esenciales, ácidos grasos esenciales, digestibilidad aparente, relación eficiencia proteica (PER), aceptabilidad y tolerancia. Los resultados indican que 100 g de la galleta contienen 5g de humedad, 16g de grasa, 16g de proteína, 61,4g de carbohidratos, 408,2 Kcal de energía metabolizable, 1,59g de cenizas, 1,9mg de hierro y 6,59g de aminoácidos esenciales. Los ácidos grasos poliinsaturados se encuentran en mayor proporción que los ácidos grasos saturados. Los resultados indican también que 100g de la galleta aportan por lo menos 20 por ciento de los requerimientos diarios de calorías, 24 por ciento de hierro y entre el 30 al 50 por ciento del requerimiento proteico diario en escolares. La digestibilidad y el PER, evaluados en ratas, fueron de 88,4 por ciento y 2,32 respectivamente. La aceptabilidad evaluada en niños fue de 97 por ciento y no se reportó intolerancia al producto en un período de seis meses de evaluación. La galleta pudiera ser incluida como complemento proteico y energético en los programas de merienda escolar.

Valores de zinc plasmático en una población infantil marginal de Maracaibo, Venezuela / Zinc plasma values in an infantile low socieconomic status population in Maracaibo, Venezuela

El objetivo del presente trabajo fue determinar la concentración plasmática de zinc en una población infantil marginal de Maracaibo, Venezuela, con el fin de establecer el estado nutricional de este oligoelemento. Se estudiaron 159 niños (M:75; F:84) entre tres meses y ocho años, provenientes de familias de bajos ingresos, clasificándose nutricionalmente de acuerdo a criterios clínicos y antropométricos. La sangre se obtuvo por punción venosa, en ayunas, midiendose el zinc plasmático por espectrofotometría de absorción atómica. Los niveles plasmáticos de zinc fueron inferiores a 75 µg/dl en el 38,36 por ciento de los niños. Según la evaluación nutricional, el 37,11 de la población estudiada era eutrófica, de ésta, el 33,89 por ciento mostró déficit de zinc. El resto de la población (62,89 por ciento) era desnutrida, de los cuales el 41 por ciento mostraba déficit de zinc. Al analizar por separado el grupo de niños con valores de zinc entre 75 y 80 µg/dl (zona crítica o a riesgo) el 18,65 por ciento de los eutróficos y el 10 por ciento de los desnutridos se ubicaron en este grupo; por lo consiguiente, más del 50 por ciento de la población infantil estudiada presentó niveles críticos o deficitarios de zinc plasmático. Se recomienda altamente iniciar estudios funcionales sobre el estado nutricional del zinc en la población infantil venezolana, en caso de ser deficitario, establecer programas de intervención nutricional con este oligoelemento, especialmente en la población infantil de los barrios marginales