Differentiation of intramural ganglia in the dissociated rectosigmoid of the rat: an organ culture study

The distal rectosigmoid of the developing embryonic rat was studied on each gestational day from 12 to 21. Circular muscle was first recognized on day 16 and ganglion cells on day 17. When in vitro dissociated colon from as early as the day 12 embryo reached a maturational age of 17 days (embryonic age plus days in culture), circular muscle, ganglia, and peristalsis could be detected. This indicates that neuroblasts must have migrated to the indifferent mesenchyme before day 12 of gestation. Anti-nerve growth factor immunoglobulin-G ( IgG) did not inhibit differentiation of ganglia in vitro. As a result of this study we designed an in vitro assay that can serve as a useful means to study isolated ganglion cell development.

Management of neonates and children with male pseudohermaphroditism

Twenty-five patients with male pseudohermaphroditism were treated. Causes included (1) inadequate testosterone production, (2) incomplete conversion of testosterone to dihydrotestosterone, and (3) insufficient androgen-binding protein at the target cell. These various problems can be defined accurately today. These infants should be studied early to define which gender role is more appropriate. Change in gender assignment later can be disastrous. An individual raised in the female role, but with incomplete internal structures, can cope with life better than one raised in the male role but lacking a satisfactory phallus. In general, we believe most male pseudohermaphrodites should be raised as females, performing appropriate alterations at an early age.

Programmed cell death in the Müllerian duct induced by Müllerian inhibiting substance

The importance of a secretory product of the fetal testis, Müllerian Inhibiting Substance, in determining the fate of the Müllerian duct in the developing male fetus has been well documented. The present investigation has examined the mechanism of action of Müllerian Inhibiting Substance in the male rat fetus during the course of Müllerian duct degeneration. The action of Müllerian Inhibiting Substance mimics the general morphogenetic phenomenon of "programmed cell death," although important diferences were found compared to the majority of other studies of cell death. The initial morphological event in the degenerating Müllerian duct is an increase in lysosomes within the duct cells. Following loss of polarity and orientation, the duct cells are subsequently removed by invading macrophages from the surrounding mesenchyme. Concommitant with the differentiation of these macrophages, the adjacent mesenchyme assumes a characteristic whorled pattern around the degenerating Müllerian duct. Cytochemical localization of acid phosphatase confirmed the presence of newly formed lysosomes within the Müllerian duct cells and subsequently within the cytoplasm of the invading macrophages.

Maturation of the rectoanal response in premature and perinatal infants

Twenty unselected premature and perinatal infants, and 40 older infants and children with chronic constipation were investigated manometrically. Anorectal pressure studies were found to be a safe and reliable screening method for Hirschsprung's disease. Many unnecessary deep and superficial rectal biopsies were avoided by recording a normal rectoanal response. Failure to record a normal reflex requires further evaluation by tissue diagnosis. A normal reflex does not occur in premature or perinatal infants in whom maturational age (gestational age plus age after birth) has yet to reach 39 wk, and who weigh less than 6 lb.

Mullerian inhibiting substance in human testes after birth

Tiny testicular biopsies from humans were assayed for Mullerian inhibiting Substances using a graded organ culture technique. Mullerian Inhibiting Substance activity was high during the first year of life, declined during the second year of life, and then disappeared. Mullerian Inhibiting Substance activity is lower in boys with undescended testis than in children with normal or intersex testes at comparable ages under two years. It is possible that Mullerian Inhibiting Substance affects testicular descent as well as causing Mullerian duct regression.

Aspergillus-induced small bowel obstruction in a leukemic newborn

An infant with congenital acute myelocytic leukemia, who was being treated with chemotherapeutic agents, developed obstruction and infarction of the ileum due to occlusion of mesenteric arteries by Aspergillus hyphae. This case demonstrates how blood vessel occlusion by occult aspergillosis can present clinically as a surgical emergency.

Crossed renal ectopia in children

Nine children were treated with crossed fused renal ectopia, and in 8 there were serious other urinary tract malformations which were surgically correctable. The finding of crossed fused renal ectopia warrants complete urologic investigation including cystogram and cystoscopy to rule out surgically correctable pathology in the urinary tract.

Effect of dry and humidified gases on the respiratory epithelium in rabbits

A laboratory study was conducted in rabbits to compare histologic changes in the lungs and bronchi after prolonged dry anesthesia and humidified anesthesia. Dry anesthesia caused severe damage to the respiratory epithelium, which was not observed with humidified controls.

Renal parenchymal tolerance to artery occlusion: a time and damage study in rats developing collateral circulation

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Obturator bypass graft in radical excision of inguinal neoplasm

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