Regeneration of Retinotectal Projections After Optic Tectum Removal in Adult Newts

Purpose: When injured, the adult newt possesses the remarkable capability to regenerate tissues and organs with return of function and physiology. One example is the newt eye, in which regeneration can restore normal vision if the retina or lens has been removed. We wanted to examine how the retinotectal projections regenerate after removal of the brain’s optic tectum and establish this animal as a model for retinal projection as well as a central nervous system regeneration model

Fine Structure of the Iris Muscle in the Japanese Common Newt, Cynops pyrrhogaster, with Special Reference to Innervation : Cell Biology

Volume: 5Start Page: 337End Page: 34

Axillary skin crease incision versus conventional posterolateral incision in open repair of patent ductus arteriosus for extremely low birth weight infants: a retrospective study

Abstract Background Thoracotomy with posterolateral incision (PLI) is commonly used for surgical repair of patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants. Some reports have described thoracotomy for PDA using an axillary skin crease incision (ASCI) in consideration of cosmetic problems such as surgical wounds and thoracic deformities, but the details remain unclear. Methods In this study, we performed clipping ligation by thoracotomy with ASCI for ELBW infants with PDA from 2011 to 2015 for the purpose of improving cosmetic results, and retrospectively compared the results with those for conventional PLI cases performed from 2016 to 2020. Results ASCI was found to be associated with serious surgical complications and showed a significant difference in outcome parameters only for surgery time, suggesting a safety problem for ASCI. Considering these results, PLI allows clipping of the nearby PDA from the thoracotomy wound while looking straight ahead, whereas the PDA in ASCI is positioned deep and oblique to the thoracotomy wound, so the clipping angle is limited and accurate completion of the procedure is difficult. Conclusions Regarding PDA repair in ELBW infants, ASCI shows a high risk of serious surgical complications. Conventional PLI remains preferable for safe and accurate results

Mice conditionally expressing RET(C618F) mutation display C cell hyperplasia and hyperganglionosis of the enteric nervous system

Medullary thyroid carcinoma (MTC) develops from hyperplasia of thyroid C cells and represents one of the major causes of thyroid cancer mortality. Mutations in the cysteine‐rich domain (CRD) of the RET gene are the most prevalent genetic cause of MTC. The current consensus holds that such cysteine mutations cause ligand‐independent dimerization and constitutive activation of RET. However, given the number of the CRD mutations left uncharacterized, our understanding of the pathogenetic mechanisms by which CRD mutations lead to MTC remains incomplete. We report here that RET(C618F), a mutation identified in MTC patients, displays moderately high basal activity and requires the ligand for its full activation. To assess the biological significance of RET(C618F) in organogenesis, we generated a knock‐in mouse line conditionally expressing RET(C618F) cDNA by the Ret promoter. The RET(C618F) allele can be made to be Ret‐null and express mCherry by Cre‐loxP recombination, which allows the assessment of the biological influence of RET(C618F) in vivo. Mice expressing RET(C618F) display mild C cell hyperplasia and increased numbers of enteric neurons, indicating that RET(C618F) confers gain‐of‐function phenotypes. This mouse line serves as a novel biological platform for investigating pathogenetic mechanisms involved in MTC and enteric hyperganglionosis

Strategy for surgical treatment of congenital subglottic stenosis in children

BACKGROUND/PURPOSE: Congenital subglottic stenosis is a rare anomaly caused by thickened cricoid cartilage. We report our surgical techniques, comprising anterior cricoid split (ACS), laryngotracheoplasty (LTP), KTP laser ablation, and application of a tracheal opening retainer (TOR) into the tracheostomy site. METHODS: Nine patients have been treated since 1988. Four patients (median age 85 days; range 5 days to 6 months) underwent ACS. Another four patients (median age, 17 months; range, 5–57 months) underwent LTP using costal cartilage grafts, although two had undergone tracheostomy before LTP. One patient underwent LTP, ablation of the projecting part of the cricoid cartilage with KTP laser (LTP + Laser) and, preservation of the tracheal opening by placement of the TOR. RESULTS: All ACS and LTP patients were successfully extubated at a median of 32 days (range 23–91 days) and 23 days (range 6–31 days) postoperatively, respectively. The LTP + Laser patient was extubated 35 days after surgery and the TOR was removed asymptomatically 20 days after extubation of the stent tube. CONCLUSIONS: Anterior cricoid split is useful for patients ≤6 months old and LTP is useful for patients >6 months old and/or with tracheostomy. KTP laser ablation is effective to remove thickened parts of cricoid cartilage protecting the vocal cords. The tracheal opening preserved by the TOR works as an additional channel to safeguard respiration during the extubation process

Nonocclusive Mesenteric Ischemia Rescued by Immediate Surgical Exploration in a Boy with Severe Neurodevelopmental Disability

Background. Nonocclusive mesenteric ischemia (NOMI) defines acute mesenteric ischemia without occlusion of the mesenteric arteries. The most common cause of NOMI is vasoconstriction or vasospasm of a mesenteric artery. NOMI generally affects patients >50 years of age, and few cases have been reported in children. Case Presentation. A 15-year-old boy with severe neurodevelopmental disability developed sudden-onset fever, abdominal distention, and dyspnea. Laboratory and radiological findings indicated acute intestinal obstruction and prerenal failure. He developed transient cardiopulmonary arrest and hypovolemic shock. Emergent laparotomy was performed, which revealed segmentally necrotic intestine from the jejunum to the ascending colon with pulsation of peripheral intestinal arteries, leading to a diagnosis of NOMI. The necrotic intestine was resected, and stomas were created. He was discharged on postoperative day 334 with short bowel syndrome as a complication. Conclusions. NOMI should be considered a differential diagnosis for intestinal symptoms with severe general conditions in both adults and children with underlying disease. Immediate surgical exploration is essential with NOMI to save a patient’s life