Co-existence of anemia, vitamin A deficiency and growth retardation among children 24-84 months old in Maracaibo, Venezuela.

Iron deficiency anemia has been associated with alterations in child development and psychomotor function, being myelination and dopaminergic functioning especially vulnerable. Iron deficiency, at different ages, has different reversible and irreversible effects on CNS. Anemia has also been related to vitamin A deficiency (VAD) and growth retardation. The aim of the present paper was to determine the coexistence of micronutrient deficiency, iron and vitamin A, and macronutrient deficiency (growth retardation). The sample consisted of 202 Venezuelan children, aged 24-84 month old, (104 girls, 98 boys); Anemia, VAD and growth retardation was evaluated by means of blood hemoglobin concentration analysis, HPLC serum retinol (values <20 microg/dl reveal VAD) and height/age and weight/age Z scores (< or = - 2 SD express stunting and underweight). Prevalence of anemia was 38.11%; VAD, 21.78%; stunting, 14.36% and underweight, 9.40%. Anemia and VAD clustered in 7.92%; anemia + stunting or + underweight coexisted in 5.94% and 2.97%, respectively. Stunting and underweight clustered with VAD in 2.97% and 1.48%. The three-way combination with anemia was only seen with stunting in 0.99% of the sample. The prevalence of micronutrient deficiencies remain as significant public health problems which should be simultaneously treated as virtually independent, giving priority to infant, toddler and preschool age groups.

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

Correlative microscopy of cerebellar Bergmann glial cells.

Double fluorescent labelling of rat cerebellar cortex using antibody to glial fibrillary acidic protein (GFAP) and Alexa fluor conjugates for secondary detection for confocal laser scanning microscope (CLSM), field emission scanning electron microscopy (FESEM) of Rhesus monkey cerebellar cortex, ultrathin sectioning and freeze-etching replica method for transmission electron microscopy of mouse cerebellar cortex have been examined in an attempt to obtain a new and more accurate view of three-dimensional image of Bergmann glial cells (BGC) and their topographic relations in the molecular layer. Intense immunopositive GFAP green staining was observed in the BGC and glial limiting layer. Secondary antibody conjugated with Alexa fluor 488 and Alexa fluor 668-1B4 stained in red capillary endothelial cells and microglial cells. BGC morphology revealed the existence of several cell types or subpopulations of BGC. Bergmann glial fibers, in palisade arrangement, branch and rebranch forming a complex glial network in the molecular layer. Field emission SEM and freeze-fracture SEM method show the SE-I image of high mass dense Bergmann glial cytoplasm ensheathing like a veil the Purkinje cell (PC) soma and dendritric arborization. Bergmann glial fibers appeared completely surrounding individual parallel fibers or parallel fiber bundles, terminal climbing fiber collaterals, basket and stellate cells and capillaries. Freeze-etching direct replicas showed the typical orthogonal arrangement of intramembrane particles, corresponding to the large repertoire of BGC receptors. The study reveals three-dimensional Bergmann glial cells heterogeneity and the complex network formed by Bergmann glial cells in the molecular layer.

A light and electron microscopic study of oedematous human cerebral cortex in two patients with post-traumatic seizures.

PRIMARY OBJECTIVE: Brain cortical biopsies of two patients with clinical diagnosis of complicated brain trauma who had seizures, were studied by means of light and electron microscopes in order to correlate structural alterations with seizure activity. METHODS AND PROCEDURES: Biopsy samples of left frontal cortex and right parietal cortex were processed by current techniques for light and transmission electron microscopy. RESULTS: The tissue showed severe vasogenic oedema with perivascular and intraparenchymatous haemorrhages. At the capillary wall, increased vesicular and vacuolar transendothelial transport, open endothelial junctions, thickened basement membrane and swollen perivascular astrocytic end-feet were observed. Some pyramidal and non-pyramidal nerve cells appeared dense and shrunken and others exhibited marked intraneuronal enlargement of membrane compartment. The myelinated axons displayed signs of degeneration and a process of axonal sprouting. Numerous swollen asymmetrical axo-dendritic synaptic contacts were observed in the neuropil, which exhibited mostly closely aggregated spheroidal synaptic vesicles toward the presynaptic membrane and numerous exocytotic vesicles sites. The perisynaptic astrocytic ensheathment appeared retracted or absent, whereas the extracellular space appeared notably dilated. Synaptic disassembly was also observed. CONCLUSION: The findings demonstrate, in two patients with post-traumatic seizure activity, brain barrier dysfunction, vasogenic oedema, anoxic-ischaemic neurons, axonal sprouting, numerous altered excitatory synapses and synaptic disassembly. Some considerations on clinical and research applications are discussed.

[Imbalance of plasma amino acids in patients with autism and subjects with attention deficit/hyperactivity disorder]. / Desequilibrio de aminoácidos plasmáticos en pacientes autistas y en sujetos con trastorno de déficit de atención o hiperactividad.

INTRODUCTION: Plasma and brain amino acids are influenced by dietary intake. Alterations of plasma amino acid concentrations have been reported in neuropsychiatric disorders. OBJECTIVE: To analyse the plasma amino acid values in subject diagnosed with autism, with attention deficit/hyperactivity disorder (ADHD), and healthy subjects as controls. PATIENTS AND METHODS: Forty subjects affected by autism, 11 with ADHD and 41 healthy subjects (age range 3 18 years old) were included in this study. Peripheral venous blood was obtained in fasting condition, collected in EDTA tubes and centrifuged. Plasma was de proteinised with sulfosalicylic acid. Amino acids were analysed by ion exchange liquid chromatography with an LKB amino acid analyser with sodium citrate elution system and ninhydrin reaction. Results were expressed as mmol/L. RESULTS AND CONCLUSIONS: In both disorders a diminution of phenylalanine and glutamine plasma concentrations was observed beside an increase of glycine. Lysine appeared increased only in autistic subjects. These alterations produce an imbalance with the rest of plasma amino acids competing at the brain blood barrier by the same transport system thus causing alterations in the metabolism and/or transport of amino acids to the brain, altering CNS functions. The phenylalanine decreasing, beside glycine increasing appear to support the hypothesis of a disorder in the inhibitory neurotransmission system, especially in ADHD. The diminution of phenylalanine and the increasing of lysine in autism are suggestive that these two amino acids are metabolically related.

Oligodendroglial cell damage and demyelination in infant hydrocephalus. An electron microscopic study.

The hydropic changes of oligodendroglial cells have been examined by means of transmission electron microscopy in seventeen cases of human, mostly infant hydrocephalus and associated pathology. Hydropic oligodendrocytes exhibited dilated endoplasmic reticulum and nuclear envelope, edematous mitochondria, enlarged and fragmented Golgi complexes, dense bodies and nuclear chromatin homogenization. A process of nuclear pore disassembly, extrusion of nuclear heterochromatin and an apoptotic-like process were observed in some swollen oligodendrocytes. Some resting or quiescent oligodendrocytes were also observed in the edematous neuropil. Oligodendrocyte cell processes appeared atrophic, degenerated and isolated in the enlarged extracellular spaces. They did not show any association with neighbouring axons, and myelinated axons were not observed in the neuropil. These observations suggest demyelination in infant hydrocephalus.

Light microscopy, confocal laser scanning microscopy, scanning and transmission electron microscopy of cerebellar basket cells.

The cerebellar basket cells of mice, hamsters, teleost fishes and human have been studied by means of Golgi light microscopy, confocal laser scanning microscopy, scanning and transmission electron microscopy. Golgi light microscopy showed ascending dendrites toward the molecular layer and descending and transverse axonal collaterals contributing to the formation of Purkinje cell pericellular basket. Confocal laser scanning microscopy provided z-series of optodigital sections of ascending basket cell dendrites and descending axonal collaterals participating in the Purkinje cell pericellular nest and the pinceaux. Scanning electronmicrographs displayed the three-dimensional relief of Purkinje pericellular nest formed by basket cell descending and transverse axonal collaterals. Transmission electron microscopy, used as a complementary technique, showed the synaptic contacts formed by basket cell axonal collaterals on Purkinje cell soma and the axosomatic contacts on basket cells by parallel and climbing fiber endings, basket cell axonal terminals and/or Purkinje cell recurrent axonal collaterals. Pre- and postsynaptic membrane specializations were mainly found in parallel fiber axosomatic contacts on basket cells, but not in the Purkinje cell pericellular basket and in other axosomatic contacts on basket cells. These latter findings have been adscribed to a phenomenon of cerebellar synaptic plasticity related with motor learning performance. The correlative microscopy approach demonstrates the potential value of these methodologies for studying the three-dimensional aspect of short intracortical circuits in the central nervous system.

Consecutive light microscopy, scanning-transmission electron microscopy and transmission electron microscopy of traumatic human brain oedema and ischaemic brain damage.

Cortical biopsies of 11 patients with traumatic brain oedema were consecutively studied by light microscopy (LM) using thick plastic sections, scanning-transmission electron microscopy ((S)TEM) using semithin plastic sections and transmission electron microscopy (TEM) using ultrathin sections. Samples were glutaraldehyde-osmium fixed and embedded in Araldite or Epon. Thick sections were stained with toluidine-blue for light microscopy. Semithin sections were examined unstained and uncoated for (S)TEM. Ultrathin sections were stained with uranyl and lead. Perivascular haemorrhages and perivascular extravasation of proteinaceous oedema fluid were observed in both moderate and severe oedema. Ischaemic pyramidal and non-pyramidal nerve cells appeared shrunken, electron dense and with enlargement of intracytoplasmic membrane compartment. Notably swollen astrocytes were observed in all samples examined. Glycogen-rich and glycogen-depleted astrocytes were identified in anoxic-ischaemic regions. Dark and hydropic satellite, interfascicular and perivascular oligodendrocytes were also found. The status spongiosus of severely oedematous brain parenchyma observed by LM and (S)TEM was correlated with the enlarged extracellular space and disrupted neuropil observed by TEM. The (S)TEM is recommended as a suitable technique for studying pathological processes in the central nervous system and as an informative adjunct to LM and TEM.

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

The present cross sectional study was carried out to estimate the prevalence of vitamin A deficiency among children by means of clinics and conjunctival impression cytology (CIC), and nutritional status by anthropometric indicators H//A, W//A, W//H. The study population included 157 children 2-6 y old, from urban and rural slums of Maracaibo, Venezuela, Conjunctival impression cytology was performed by ICEPO standard procedure. Z-score was applied to anthropometric data with reference values of NCHS-WHO. No evidence of clinical or ophthalmologic signs of vitamin A deficiency were detected. The prevalence of subclinical vitamin A deficiency, as detected by abnormal CIC, was 35.4%, being higher in rural children (48.3%). These prevalence values are higher than the criteria laid down by WHO/UNICEF to indicate a public health problem (> 20%). Mild or moderate protein-energy global malnutrition and stunting were detected in 36.1% and 44.6% of children, respectively. Abnormal CIC was indistinctly observed (approximately equal to 35%) as much in children with adequate nutrition as in malnourished ones. There was no significant difference in the distribution of the CIC results in relation to nutritional status. The findings indicate that CIC and Z-score of nutritional anthropometric data are useful to characterize the risk of vitamin A deficiency and of malnutrition in communities. Beside the implementation of an integral nutritional program which includes supplementation, food fortification and dietary diversification, improvement of socio-economic and sanitation conditions and also the educational level, with emphasis on nutritional and health education, are highly recommended.

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.

Field emission scanning electron microscopy and freeze-fracture transmission electron microscopy of mouse cerebellar synaptic contacts.

Samples of albino mice were processed by the cryofracture method for scanning electron microscopy and examined with the field emission scanning electron microscope (FESEM). Freeze-etching direct replicas of mice cerebellar cortex were also studied with the transmission electron microscope (FFTEM), as a complementary technique for obtaining higher resolution, three-dimensional correlative images of cerebellar synaptic contacts. At the granular, Purkinje cells and molecular layers, the cryofracture method for FESEM selectively removed the neuroglial cell investment, facilitating the visualization of the outer and inner surfaces of cerebellar synaptic contacts. In addition, FFTEM showed the real extension of perisynaptic neuroglial investment. The outer surface of mossy fiber rosettes and their digitiform processes were seen at the granular layer, making flat and invaginated synaptic contacts with the granule cell dendrites. At the molecular layer, the longitudinal traject of parallel fibers or nonsynaptic segments and their synaptic varicosities were characterized. These latter established synaptic contacts with Purkinje dendritic spines. Fractured parallel fiber endings showed the SE-I images of clustered spheroidal synaptic vesicles and mitochondria and the surrounding cotton-like appearance of Bergmann glial cell cytoplasm. Climbing fibers showed a characteristic crossing-over bifurcation pattern in the white matter and in the three-layer structure of cerebellar cortex, formation of tendril collaterals in the granular layer, topographical relationship with Purkinje cell soma and retrograde collaterals in the molecular layer. The climbing fiber synaptic relationship with Purkinje dendritic spines was characterized, by means of FFTEM, by the presence of large synaptic endings and aggregation of intramembrane particles at the P and E faces of presynaptic endings, characteristic of excitatory synapses.

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, scanning and transmission electron microscopic study of cerebellar mossy fiber glomeruli.

A correlative microscopic study of vertebrate cerebellar mossy fiber glomeruli has been carried out to obtain a three-dimensional view of the multisynaptic contacts formed by afferent mossy fibers with the granule and Golgi cell dendrites and by the monosynaptic relationship of Golgi cell axonal ramifications with granule cell dendrites. Samples of mice, hamsters, teleost fishes and human species were studied by means of one of the following procedures: confocal laser scanning microscopy (CLSM), ethanol-cryofracturing technique and conventional scanning electron microscopy (CSEM) and transmission electron microscopy (TEM) by ultrathin sections and freeze-etching replicas. CLSM, by means of montages of z-series of the cerebellar granular layer, provided a new approach to explore mossy fiber trajectory and branching bifurcation pattern and the quantitative relationship between mossy fibers and granule cell dendrites. CSEM and freeze-fracture method for SEM offered a more detailed in-depth, higher resolution image of outer and inner surface organization of mossy fiber glomeruli. TEM, either by ultrathin sections or freeze-etching replicas, was used as complementary technique for proper orientation, comparative purposes and rational identification of pre- and postsynaptic structures. Freeze-etching replicas showed in addition the real extent of glial cell cytoplasm encapsulating the synaptic glomeruli. The integrated microscopy approach offers a new and more comprehensive view of three-dimensional morphology, organization and quantitative aspects of mossy fiber glomeruli.

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.

Oligodendroglial cell behaviour in traumatic oedematous human cerebral cortex: a light and electron microscopic study.

Cortical biopsies of 12 patients with traumatic brain injuries have been used in the present study to examine oligodendroglial cell changes and reactivity. The samples were processed for light and transmission electron microscopy. Four main types of oligodendrocyte populations have been found: resting or unreactive oligodendrocytes, reactive oligodendrocytes, anoxic-ischaemic oligodendroglial cells and hyperthrophic phagocytic oligodendrocytes. The unreactive or resting oligodendrocyte type exhibited a fusiform or elongated shape, a clear or dense band of scarce perikaryal cytoplasm and a nucleus with peripheral heterororomatin masses. Clear or dense reactive oligodendrocytes showed increased amount of perikaryal citoplasm, dilated endoplasmic reticulum and nuclear envelope, numerous clear, oedematous mitochondria and dense bodies. These oligodendrocytes appeared associated with degenerated myelinated axons. Anoxic-ischaenmic oligodendrocytes showed lacunar enlargement of endoplasmic reticulum, dilated Golgi complex and enlargement and disassembly of nuclear envelope. They appeared also in contact with degenerated myelinated axons. Hypertrophic phagocytic oligodendrocytes were observed engulfing the associated degenerated myelinated axons, invading the myelin sheath, separating the myelin lamellae and exerting myelinolitic effects. Oligodendroglialpseudopodic expansions were observed phagocyting the axoplasmic matrix and leaving a huge vacuolar axoplasmic space. The vasogenic and cytotoxic components of traumatic brain oedema are discussed in relation with the oligodendroglial cell changes and reactivity.

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.

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.

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.

Imbalance of Individual Plasma Amino acids Relative to Valine and Taurine as Potential Markers of Childhood Malnutrition.

In the present study a typical plasma amino acid profile for a defined population of healthy Venezuelan children was established and, further, the possibility was examined that deviations from such normalized amino acid patterns can be of use to warn of an impending nutritional deficiency, caused, in part, by adverse socio-economic conditions. This study comprised 152 children of both sexes ranging in age from 1 to 6 years. Classification into different socio-economic strata, ranging from impoverished to privileged, was evaluated by Graffar's method, as previously adapted by Mendez Castellano for Venezuela. The results of clinical and anthropometric examinations were used to group these children into 5 classes of nutritional sufficiency, ranging from adequate nutrition to severe undemutrition. The present data indicate that deviations in the plasma amino acid concentration profile, standardized for a defined population, can be used in combination with clinical evaluations to determine the type as well as the severity of inadequate nutrition. Abnormal ratios of several individual amino acids relative to Val and Tau may serve as early signs of (impending) undemutrition or malnutrition in children; the amino acid changes are detectable even in groups of children without any clinical signs but where sociological circumstances suggest a possibility of inadequate nutrition. Other uses for such plasma amino acid profiles may be to distinguish whether the detected amino acid abnormalities are of dietary or genetic origin, provided that the selected groups or individuals studied derive from a population with more or less the same genetic homogeneity and similar dietary customs.

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

The nutritional characteristics of a cookie formulated with bovine plasma as main protein source was evaluated. Bovine plasma was mixed with wheat flour, sugar or salt, condiments and vegetable oil. The mix was placed in trays and baking at 120 degrees C during 1 hour. Moisture, fat, protein, carbohydrate, metabolizable energy, ash, iron, essential amino acids, essential fatty acids, apparent digestibility, protein efficiency ratio, acceptability and tolerance of the final product were determined. Results indicated that 100 g of the cookie have 5 g of moisture, 16 g of fat, 16 g of protein, 61.4 g of carbohydrate, 408.2 Kcal of metabolizable energy, 1.59 g of ash, 1.9 mg of iron and 6.59 g of essential amino acids. Polyunsaturated fatty acids are in higher amount than saturated fatty acids. Results also indicated that 100 g of cookie provide at least 20% of the daily energy requirements, 24% of the iron and between 30 to 50% of the daily protein requirements for children at school age. Its digestibility and PER, tested in rats, were of 88.4% and 2.32 respectively. Acceptability and tolerance, both tested in children, were 97% and 100% respectively. The protein cookie could be included as a protein and energy supply in school meals.