Heterogeneous Expression of Chondroitin Sulfate Glycosaminoglycans and Versican Proteoglycan during Early Development of Rathke’s Pouch

While much is known regarding morphogenetic factors involved in specification and differentiation of Rathke’s pouch, less attention has been given to extracellular matrix (ECM) interactions involved in its formation. The present research investigated localization of two different chondroitin sulfate glycosaminoglycans (CS-GAGs), TC2 and d1C4, and versican CS-proteoglycan (PG) to identify additional ECM molecules involved in formation of the pituitary rudiment. Immunohistochemical evaluation of anterior pituitary primordia between HH15 and HH28 showed these ECM molecules prevalent in basement membrane and surrounding ECM underlying Rathke’s epithelia and to a lesser extent between pouch epithelial cells. TC2/d1C4 CS-GAGs and versican showed changing and heterogeneous localization during pouch development that suggested specific roles in cell-ECM interaction during pituitary morphogenesis. TC2 antigen colocalized with versican at early stages in an asymmetric pattern, with particularly strong staining between ventral diencephalon and roof of Rathke’s pouch while d1C4 CS-GAG encompassed the entire pouch by HH22 indicating association with a different CSPG. The heparan sulfate proteoglycan, perlecan, used to verify basement membrane structure, was a consistent component of Rathke’s pouch. Data show a dynamic and heterogeneous pattern of CS-GAG and versican expression during early chick Rathke’s pouch development that suggests new possibilities for ECM function in its establishment and growth.

Variants of Currarino Syndrome: Embryological Association and Review of Pertinent Literature

Currarino syndrome is a triad of sacral defect, anorectal malformation and a presacral mass. The diagnosis is usually made late in childhood and about 50% of cases are familial with autosomal dominant inheritance. We present two neonates (one with vestibular fistula, and another with cloacal malformation) with the features consistent with Currarino syndrome, but with Altman’s type II sacrococcygeal teratoma, that is, presacral mass having an external sacrococcygeal component also. We believe that this triad should be considered a variant of Currarino syndrome. In first case, excision of the mass along with coccyx, followed by primary Posterior Sagittal AnoRectoPlasty was performed in the same setting. The patient succumbed to death due to septicemia as a result of wound sepsis. Learning from the previous experience, we decided to do a diverting sigmoid loop colostomy followed by posterior sagittal excision of the mass along with coccyx, in same sitting in the second case. There was no recurrence. Though HLXB9 has been identified as the major causative gene in Currarino syndrome, exact pathogenesis is still unclear. We herein highlight the significance of this variant of Currarino syndrome and propose a theory on the basis of an embryological association between the malformation complex.

Histological Changes of the Mandibular Condyle in the Human Fetus at Early Stages of Gestation

Histochemical studies on the mandibular condyle of the human fetus at gestational ages 12, 14, and 16 weeks were performed. Methods. Histological sections were stained with Schiff’s periodic reaction for glicoproteins, hematoxiline eosine detects mesenchymal tissue and trichhromic stain for collagen. The ANOVA one-way test was used to evaluate the differences during stained zones in the three fetus groups. Results. The percentage of glycoproteins and mesenchymal tissue was denser at 12 weeks. This percentage decreases at 14 weeks and is less at 16 weeks. An increase in the amount of collagen in the studied weeks was observed. The percentages of glycoproteins, mesenchymal tissue, and collagen were significantly different; f = 4373, 9624.8, and 3674, P<0.0001 for the three studied groups. Conclusion. The endochondral bone formation of the mandibular condyle includes modifications of the quantities of glycoproteins, mesenchymal tissue, and collagen.