Estudio morfométrico de las suturas palatinas humanas en recién nacidos, infantes y niños con fines de tratamiento por distracción osteogénica / Morphometrical study of human palatine sutures in newborns, infants and children for distraction osteogenesis treatment purposes

El conocimiento estructural y dimensional de las suturas palatinas es necesario para el tratamiento temprano de deficiencias transversales y longitudinales por técnicas de expansión o distracción osteogénica (DO). El objetivo fue estudiar el estado de las suturas palatinas y los cambios cambios dimensionales y morfológicos desde el nacimiento a la niñez. Fueron analizados 41 paladares óseos de ambos sexos entre 0 y 13 años, agrupándolos en recién nacidos (RN/n=17), infantes (IN/n=12) y niños (NI/n=12). Se fotografió cada paladar y se marcaron puntos craneométricos para determinar las dimensiones longitudinales y transversales de las suturas palatinas mediana premaxilar (SPPMX), mediana anterior (SPMA), posterior (SPMP), transversa anterior (SPTA) y transversa posterior (SPTP). Además se evaluó el estado sutural y dimorfismo sexual. Los resultados se sometieron a las pruebas OneWay-ANOVA, Bonferroni y t-test. Las suturas SPMA, SPMP y SPTP no presentaron sinostosis. La SPPMX se observo parcialmente sinostosada en 5,9 por ciento de RN y 16,7 por ciento de NI, y la SPTA en 8,3 por ciento de IN y 41,7 por ciento de NI. Al comparar la longitud sutural en los tres grupos, las dimensiones longitudinales estadísticamente significativas en todos los grupos (p<0,001). No hubieron diferencias en las suturas transversales entre IN y NI (p=0,32). Se observó dimorfismo en IN entre las SPMA y SPTP. El sistema sutural palatino juega un rol importante durante el crecimiento por su disposición sagital y transversal, permitiendo un crecimiento bidireccional del paladar. El crecimiento longitudinal es constante, mientras que el transversal muestra un peak hasta los 2 primeros años de vida y luego disminuye, sugiriendo la existencia de diferentes potenciales de crecimiento. Estas observaciones podrían explicar la alta prevalencia de alteraciones de crecimiento transversal en los niños...

Structural and dimensional knowledge of palatal sutures are necessary for early treatment of deficiencies by transverse and longitudinal expansion techniques or distraction osteogenesis (DO). The aim was to study the status and dimensional or morphological changes of palatal sutures from birth to childhood. Forty one bony palates of both sexes, between 0 and 13 yearsandgrouped in newborns (NB/n = 17), infants (IN/n = 12) and children (CH/n=12) were analyzed. All palates were photographed and craniometrics points were scored to determine the longitudinal and transverse dimensions of the palatal sutures: premaxillary (PMX), anterior midpalatal suture (AMPS), posterior midpalatal suture (PMPS), anterior transverse palatal suture (ATPS) and posterior transverse palatal suture (PTPS). In addition, we evaluated the sutural and sexual dimorphism. The results were subjected to tests OneWay - ANOVAandBonferroni t-test. AMPS, PMPS and PTPS no showed synostosis. PMX was observed partially sinostosed in 5.9% of NB and 16.7% of CH, and ATPS in 8.3% of IN and 41.7% of CH. When comparing the sutural length between groups, the differences were significant in all cases (p <0.001). There were no differences in transverse sutures between IN and CH groups (p=0.32). Sexual dimorphism wasobserved between AMPS and PTPS groups. The palatal suture system plays an important role during growth by sagittal and transverse available, allowing bidirectional growth of the palate. Longitudinal growth is constant, while the cross shows a peak until the first 2 years of life and then decreases, suggesting the existence of different potentials growth. These observations may explain the high prevalence of abnormal transverse growth in children...

Bilateral reversed palmaris longus muscle: a rare anatomical variation.

We report a case of bilateral reversed palmaris longus muscle (PLM). The muscle was tendinous in its upper portion and muscular in its lower portion in both arms. This rare variation has been mentioned only once in the literature as a surgical finding. According to the literature, a reversed PLM may cause a compartment syndrome in the wrist area, carpal tunnel, and Guyon's syndrome. The described variation is also useful to the hand surgeon as a tendon graft, a tendon for transfer, or as an anatomical landmark for operations at this area.

Tuberomammillary nucleus activation anticipates feeding under a restricted schedule in rats.

We used FOS-immunoreactivity to map changes in the neuronal activity of brain nuclei related to the state of arousal, in rats under a restricted feeding schedule. Our main finding was the outstanding activation of the tuberomammillary nucleus 24h after a meal, and its steep deactivation, which was independent of actually having the meal. The time course of FOS activation and deactivation indicated a burst of tuberomammilary nucleus activity in close temporal relation with the increased locomotor activity shown by rats in anticipation of the next meal.

NADPH-d positive neurons in the developing somatosensory cortex of the rat: effects of early and late environmental enrichment.

The effects of environmental enrichment upon the topographic arrangement of NADPH diaphorase-positive neurons (NADPH-d+ neurons) was studied in the somatosensory cortex of 56 Sprague-Dawley albino rats during early stages of development (18th, 24th, 30th and 60th postnatal days). This diaphorase is easily demonstrable, providing a convenient marker for quantitative studies. Environmental enrichment diminished the number of NADPH-d+ neurons and exerted its maximal influence during lactation, a time of exceptional cortical susceptibility. This implies that the magnitude of such effects on the density of NADPH-d+ neurons is age-dependent. Furthermore, it was found that the experience-dependent cortical changes persisted after a subsequent period without environmental stimulation. The effects of early environmental enrichment did not occur uniformly throughout the cerebral hemispheres but, instead, such effects were maximal in the latero-ventral sector of the cerebral cortex where a dramatic reduction in the number of NADPH-d+ neurons was observed. Particularly striking was the existence of a latero-medial sequence of NADPH-d+ neurons in the infragranular layer and a reversed distribution of labeled cells, in the supragranular layer. Both ontogenetic sequences of NADPH-d+ neurons remained unchanged during postnatal development in controls and enriched subjects (18th-60th postnatal days).

Distribution of NADPH-d positive neurons during postnatal development of the rat somatosensory cortex correlates with gradients of neurogenesis and development.

The expression of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) was studied in the rat somatosensory cortex during postnatal development from day 6 to 120. Distribution of labeled neurons was quantified in dorso-medial and ventro-lateral aspects of the cortex, and correlated with known tridimensional gradients of histogenetic development and maturation of cortical neurons. NADPH positive neurons were non-pyramidal cells that in all developmental periods were more numerous in infragranular than in supragranular layers of the cortex. Additionally, more labeled cells were found in ventro-lateral than dorso-medial infragranular layers and in anterior than posterior aspects of the cerebral cortex. These patterns of distribution correlate well with the gradients of histogenetic development and with the pattern of maturation of cortical neurons.

Early-life polysensorial stimulation and nutrition: topographic levels of susceptibility in the rat visual cortex.

The effects of environmental-nutritional interactions upon the development of the visual cortex were studied in Sprague-Dawley albino rats during lactation (5-22 postnatal days). Morphometric evaluations were assessed by measuring layer V pyramidal neurons, under camera lucida. The Golgi-Cox-Sholl technique permits quantitative studies of neurons by the precipitation of metallic mercury at random, without any selectivity. Length and frequency of dendritic segments showed significant differences due to rearing, nutrition, and topographic localization. Early environmental enrichment exerted its maximal benefits in undernourished pups, the influences being highly prominent in the lateroventral sector of the cortical plate that receives conspicuous inputs during development. These findings may provide bases for the design of clinical strategies to palliate the adverse effects of undernourishment and sensory deprivation on brain development, since their effects seem to follow pari passu the topographic sequences of cortical morphogenesis.

Effect of pre- and postnatal retinal deprivation on the striate-peristriate cortical connections in the rat.

The tangential distribution of the striate-peristriate cortical connections in normal, postnatally eye enucleated and congenitally anophthalmic rats, was studied after a single injection of wheat germ agglutinin conjugated with horseradish peroxidase into the striate cortex. The typical normal pattern of separate fields in the peristriate cortex is altered in eye enucleated animals, in such a way that their areal distribution in the cerebral cortex is increased and each field tends to fuse with the adjacent one. This process is more marked in anophthalmic animals, a finding that is in agreement with the notion that ganglion cells exert their influence before the visual pathway is functional.

Foveal topography in the optic nerve and primary visual centers in Falconiforms.

The topography of the retinal nasal and temporal foveal projections upon the optic nerve and primary visual centers was studied in diurnal bifoveate birds of prey by means of restricted tritiated proline intraocular injection. According to the degree of retinotopy, this study reveals that a single injection of tracer in the nasal or temporal fovea produces a well-defined and complementary pattern of projections in the following contralateral nuclei: lateral anterior thalamus, lateroventral geniculate nucleus (glv), superficial synencephalic (ss), tectal grey (gt), and optic tectum. In the thalamic nucleus dorsolateral anterior, the nasal foveal projections are seen mainly in the lateral and rostrolateral subdivision, while temporal projections are seen mainly in the magnocellular subdivision. In the external and ectomammillary nuclei there is some evidence of retinotopic innervation. Finally, a discrete field of projection from the nasal or temporal fovea is detected in lateral hypothalamus, ventrolateral thalamus, lateral geniculate intercalated nucleus, and pretectal optic area. The nasotemporal axis of the retina is ventrodorsally oriented in the optic nerve with ganglion cell axons of the temporal fovea more dorsally placed than the nasal ones. In the primary visual centers this retinal axis is mediolaterally represented in the nuclei glv, ss, and gt, and dorsoventrally oriented in the optic tectum.

Topography and morphology of retinal ganglion cells in Falconiforms: a study on predatory and carrion-eating birds.

The topographic distribution of retinal ganglion cells and their cell body size have been studied in five Falconiform species, including predatory (chilean eagle Buteo fuscenses australis, and sparrow hawk Falco sparverius) and carrion-eating (chimango caracara Milvago chimango; condor Vultur gryphus, and black vulture Coragyps atratus) birds. All these species had a well defined nasal fovea and a horizontal streak. Instead of a temporal fovea as in eagles and hawks, an afoveate temporal area is present in chimango, condor, and vulture. The highest ganglion cell density was found in the nasal fovea of Falco and Buteo with 65,000 and 62,000 cells/mm2, respectively. A negative correlation between ganglion cell density and cell body size was found in all the species studied. The specializations of the temporal retina showed a rather homogenous population of medium sized neurons, while the nasal foveas showed a homogeneous population of smaller ganglion cells. Finally, the peripheral retina showed a heterogeneous population of large, medium, and small ganglion cells. Predatory behavior appears to be closely related to foveal specializations, and is best exemplified in the eagle and hawk and to a lesser extent in the chimango.

Foveal regions of bird retinas correlate with the aster of the inner nuclear layer.

A radiate specialization, the aster, has been found in whole-mount retinas of birds and is associated to each one of the temporal and nasal fovea, with the one related to the convexiclivate nasal fovea more evident. This radial arrangement extends uniformly in all directions from the foveal pit. Transverse sections of the retina show that this structure is formed by bands of cells and bundles of fibers from the inner nuclear layer.

Motor innervation of the bursalis muscle (nictitating membrane) in the lizard Callopistes maculatus.

The motor neurones which innervate the bursalis muscle of the lizard Callopistes maculatus were identified by means of intra-axonal retrograde transport of horseradish peroxidase. These neurones were distributed in the oculomotor abducens and accessory abducens nuclei. In the oculomotor nucleus one group of neurones was located in the ventral subnucleus of the contralateral side while the other group was found in the dorsolateral subnucleus of the ipsilateral side. In the abducens and accessory abducens nuclei all the neurones were in the ipsilateral side. The accessory abducens cells, although less numerous, were larger and had a prominent dendritic field in close relationship with the nucleus descendens nervi trigemini.

El aster de la retina, una especialización de la capa nuclear interna / The retinal aster

Una especialización retiniana, el aster, es por primera vez descrito en montajes in toto de retinas de aves foveadas, teñidas con técnica de Nissi; el centro de esta estructura radiada coincide con el centro de la fovea. En las retinas bifoveadas se encuentra un aster asociado a cada una de las foveas nasal y temporal; en las foveas clivadas convexas el aster es más evidente. Los rayos de esta especialización se extienden en todas direcciones en una disposición regular. El análisis de secciones transversales de retina incluidas en araldit, revelan que el aster se forma por la disposición columnar de las células bipolares oblicuamente dispuestas en torno a la fovea, separadas por bandas de fibras nerviosas de la capa nuclear interna

The oculomotor nucleus, not the abducent, innervates the muscles which advance the nictitating membrane in birds.

The topographic distribution of the neurones that innervate the muscles that advance the nictitating membrane in birds was studied using intra-axonal retrograde transport of horseradish peroxidase. The motor neurones are distributed in the oculomotor complex of the ipsilateral and contralateral sides. In the ipsilateral side, the neurones innervating the pyramidalis muscles were located in the dorsolateral, dorsomedial and ventromedial subnuclei, while those neurones innervating the quadratus muscle were found in the dorsomedial and dorsolateral subnuclei. In the contralateral side the neurones innervating both the pyramidalis and quadratus were distributed in the ventromedial and ventrolateral subnuclei. The sensory neurones were found in the trigeminal ganglion and trigeminal mesencephalic nucleus.