[Early protected discharge of the mother and the neonate: case-control study]. / Dimissione precoce protetta della madre e del neonato: studio caso-controllo.

Aim of this study is to compare traditional post-partum hospital stay to hospitalization associated with early protected discharge: a case-control study has been performed to evaluate outcome as mother's appreciation of the experience as well as breastfeeding. The study included 50 healthy-term newborns and their mothers, discharged within 24 and 48 hours of life, and 44 controls, who had traditional "rooming-in" stay, delivered at the Department of Neonatology--University of Turin. The protocol included a midwife daily home visits and a neonatologist and nurse visit within 4th to 5th day of life, to evaluate mother's and baby's health status and to perform metabolic screenings. An ambulatorial follow-up visit at 1 month of life and 2 telephone interviews, at 3rd and 6th month, were also planned. During the first week of life 45 (90%) early discharged newborns had complete nursing (breastfeeding + water or other fluids), 4 (8%) had complementary nursing (breastfeeding + formula) and 1 (2%) received formula. Among controls, 46 (92%) babies received complete nursing, 2 had complementary nursing and 2 had artificial nursing. At 6 months of life breastfeeding was complete for 2% of cases and 6% of controls; in 44% of cases and 56% of controls nursing was complementary. Readmissions to our Birth Center were 2 among early discharged newborns, 1 in the control group. About project's appreciation, 96% of early discharged and 98% of control group mothers declared their availability to repeat the experience. Caring and supporting were judged adequate in 94% of both group. By adequate supporting of mother and newborn, short and traditional hospitalization are both pleasant and don't seem to present significant differences in type and length of nursing.

Quantitative genetic background effects on the Antennapaedia phenotype in Drosophila melanogaster.

Genetic background variation influencing expression of the Antennapaedia homeotic phenotype was examined by crossing the Antp73b allele of the Antennapaedia locus reciprocally into seven isogenically derived wild type strains of Drosophila melanogaster and their genetically heterogeneous parent strain, Dover. The parent Antp73b strain's Antennapaedia phenotype shows a small patch of untransformed antennal tissue remaining on the homeotic femur. The size of this patch was used as an assay for background variation influencing expression of the Antp73b homeotic mutation. Patch size varied approximately six-fold across the different genetic backgrounds. Effects of maternal parent, sex, and sex-linkage were also observed.

Modality-specific axonal projections in the CNS of the flies Phormia and Drosophila.

There is a rich history of behavioral and physiological studies on the leg sensory systems of flies. Here we examine the anatomy of the sensory axons of two species of fly and demonstrate that the location of the axonal projections in the CNS can be correlated with the modality they encode. We studied receptors associated with proprioceptive, tactile, and multimodal hairs. Proprioceptive hairs occur in clusters, called hair plates, and are situated near joints. The neuron innervating each proprioceptive hair has a large axon and coarse arborization in the intermediate neuropil. Tactile receptors have smaller arbors, which are located in a ventral region of the thoracic neuromere. Finally, the multimodal hairs are each innervated by one tactile and four chemosensory neurons. The single tactile neuron has a central arbor that is indistinguishable from those of the tactile hairs; the four chemosensory neurons project to yet a third region of neuropil near the ventral surface of each neuromere. Thus there is a clear modality-specific segregation of axonal arbors in the CNS. This organization is identical in Phormia and Drosophila and thus apparently highly conserved within the Diptera. We presume that, as in other insect sensory systems, this anatomical specificity is linked to synaptic specificity.

Compartments and the topography of leg afferent projections in Drosophila.

The legs of Drosophila are covered with mechanosensory bristles, innervated by sensory neurons that project to the CNS in a very orderly manner. We examined this afferent projection by staining the sensory neurons associated with identified bristles in wild-type, engrailed and scute flies. We observe that anterior neurons project to an anterior region of the ventral neuropil, while posterior neurons project to a more posterior region. We rule out that this difference depends on the compartment of origin of the receptors. Our results also argue against explanations based on other factors that might correlate to anterior/posterior position: peripheral organization of the leg nerve, competitive interactions, or differences in times of birth. We suggest that position itself is the primary determinant of this projection.

Genetic control of sexually dimorphic axon morphology in Drosophila sensory neurons.

The mechanism by which orderly axonal projections are formed during development remains an important and largely unsolved problem in neurobiology. It may be possible to examine the control of axon growth in Drosophila and take advantage of genetic tools to better understand the phenomenon. We show here that some gustatory axons in Drosophila are sexually dimorphic and that genes involved in sex determination control the anatomy of these axons. Both males and females possess gustatory receptors on their legs but males possess more of these receptors than females. More significantly, the axons of the male receptors usually cross the midline and they never do so in females, indicating a central zone of bilateral input in the male but not in the female nervous system. In chromosomal females, expressing a tra or Sxl mutation, the gustatory system is transformed toward the male phenotype. Mutant XX adults resemble normal males externally, because they have more gustatory receptors, and internally, because their axons cross the midline. Gynandromorphs show that the sex of the sensory neuron, and apparently not the central nervous system, controls the growth of the axons. We conclude that the anatomical site of control for this dimorphism is the gustatory neurons.