Norichika Iga

Oxytocin improves long-lasting spatial memory during motherhood through MAP kinase cascade

Oxytocin is an essential hormone for mammalian labor and lactation. Here, we show a new function of oxytocin in causing plastic changes in hippocampal synapses during motherhood. In oxytocin-perfused hippocampal slices, one-train tetanus stimulation induced long-lasting, long-term potentiation (L-LTP) and phosphorylation of cyclic AMP–responsive element binding protein (CREB), and MAP kinase inhibitors blocked these inductions. An increase in CREB phosphorylation and L-LTP induced by one-train tetanus were observed in the multiparous mouse hippocampus without oxytocin application. Furthermore, intracerebroventricular injection of oxytocin in virgin mice improved long-term spatial learning in vivo, whereas an injection of oxytocin antagonist in multiparous mice significantly inhibited the improved spatial memory, L-LTP and CREB phosphorylation. These findings indicate that oxytocin is critically involved in improving hippocampus-dependent learning and memory during motherhood in mice.

Use of a vessel sealing system versus conventional electrocautery for lung parenchymal resection: a comparison of the clinicopathological outcomes in porcine lungs

PurposeLigaSure, a vessel sealing system, has been shown to have excellent hemostatic properties; however, its use for lung parenchymal resection has been limited. We herein examined the hemostatic properties and potential for inducing histological lung injury of the LigaSure system in non-anatomic pulmonary resection to estimate the feasibility of its clinical application.MethodsNon-anatomic pulmonary wedge resections of the right cranial, middle, and caudal lobes were performed in four pigs using the LigaSure system (Group A) or electrocautery (Group B). In each resection, the resection time, blood loss, and weight of the resected lung were measured. The thermal effect on the lung tissue was examined by means of intraoperative thermography and histology.ResultsA total of 12 lung wedge resections were performed in each group. For an equivalent length of operation and weight of the resected lung parenchyma, Group A showed significantly lower blood loss and lower maximum and minimum temperatures of the lung tissue, as assessed by thermography, than Group B. The degree of thermal injury as estimated by a histological examination was lower in Group A than in Group B.ConclusionOur study suggests that the LigaSure system may be superior to conventional electrocautery, indicating its clinical usefulness for non-anatomic pulmonary resection.

Use of extended-criteria lungs on a lobe-by-lobe basis through ex vivo lung perfusion assessment

Initially rejected and extended-criteria lungs were partially used through an ex vivo lung perfusion (EVLP) assessment that was first clinically applied in Asia. The truly injured lobe (left lower lobe) was identified during 89-minute normothermic EVLP and was excised, and the remaining lobes were successfully transplanted into a patient with lymphangioleiomyomatosis. The lung lobes showed heterogeneous changes on the ex vivo rig, and a brief duration of EVLP helped differentiate lung quality on a lobe-by-lobe basis.

Detection of airway ischaemic damage after lung transplantation by using autofluorescence imaging bronchoscopy

OBJECTIVES Airway complications related to ischaemia are a major cause of morbidity after lung transplantation. Early detection of airway ischaemia and optimal management of the anastomotic site could reduce the risk of airway complications. Autofluorescence imaging (AFI) bronchoscopy has been increasingly recognized as an effective technique for detecting abnormal mucosal thickening. The aim of this study was to investigate whether AFI bronchoscopy can facilitate the detection of airway ischaemic damage in lung transplant patients. METHODS Twenty Landrace pigs were used to create a tracheal autotransplantation model. A four-ring length of trachea was excised and implanted orthotopically. The tracheal autograft was observed on postoperative days 0, 2, 4 and 7 with AFI bronchoscopy. The extent and origin of graft autofluorescence were examined using histology and measured according to fluorescence intensity. RESULTS The lesions on the tracheal autografts appeared as bright green fluorescence on AFI bronchoscopy. On confocal fluorescence microscopy, high-intensity green fluorescence was observed in the elastin fibre layer of the submucosa. The fluorescence intensity of elastin was significantly higher in the graft showing fluorescence than the graft that did not show fluorescence and that at the control site. CONCLUSIONS Bright green fluorescence was seen in an elastin fibre layer in the submucosa, which was likely a result of epithelial sloughing. There is a close relationship between the bright green fluorescence pattern observed using AFI bronchoscopy and airway ischaemic damage. We conclude that AFI bronchoscopy may detect airway ischaemic damage after lung transplantation.

Bronchial and cardiac ruptures due to blunt trauma

Tracheobronchial and cardiac injuries following blunt thoracic trauma are uncommon but can be life-threatening. We report a case in which the patient with bronchial and right atrial ruptures due to blunt trauma survived after emergent repairs. An 18-year-old female driver was transported to our hospital after a traffic accident and was hemodynamically stable on arrival. Chest computed tomography revealed cervicomediastinal emphysema and hemopericardium, and fiberoptic bronchoscopy showed a tear in the right main bronchus. She was intubated with a double-lumen endotracheal tube guided by bronchoscopy. A median sternotomy was undertaken, and a laceration of the right atrium was oversewn without the use of cardiopulmonary bypass. After that, right-sided thoracotomy was performed. The tear in the membranous portion of the right main bronchus was repaired with interrupted sutures, and the suture lines were wrapped with a pedicled flap of intercostal muscle.

Endovascular repair and pharmacotherapy of an inflammatory abdominal aortic aneurysm complicated by primary aortoduodenal fistula.

An inflammatory abdominal aortic aneurysm complicated by primary aortoduodenal fistula was successfully treated by stent grafting. Pharmacotherapy with octreotide after endovascular aneurysm repair was also performed with the expectation of spontaneous and rapid closure of the fistula. Gastrointestinal endoscopy performed 10 days after endovascular aneurysm repair showed closure of the large aortoduodenal fistula, and oral intake was started on the operative day 16. To date, 16 months after the initial operation, the patient is doing well without any symptoms or signs of infection and without any antibiotic therapy.