Regeneration and replacement in the vertebrate inner ear

Deafness affects more than 40 million people in the UK and the USA, and many more world-wide. The primary cause of hearing loss is damage to or death of the sensory receptor cells in the inner ear, the hair cells. Birds can readily regenerate their cochlear hair cells but the mammalian cochlea has shown no ability to regenerate after damage. Current research efforts are focusing on gene manipulation, gene therapy and stem cell transplantation for repairing or replacing damaged mammalian cochlear hair cells, which could lead to therapies for treating deafness in humans.     

The effects of hyperventilation upon spinal dorsal horn neuronal single-unit activities under nitrous oxide anesthesia

BACKGROUND: The purpose of this study is to investigate the effects of hyperventilation upon spinal dorsal horn neuronal single-unit activities under nitrous oxide anesthesia. METHODS: Eight decerebrated spinal cats with laminectomy were maintained with oxygen and pancuronium bromide. Following the control period of normocapnia, 50% nitrous oxide was administered for 30 minutes after a hypocapnia period of 20-25 mmHg for 20 minutes. The recoveries of activities followed with normocapnia and pure oxygen administration. The changes of spontaneous and evoked activities by the pinching were investigated every 5 minutes after control study. RESULTS: Inhalation of 50% nitrous oxide suppressed the WDR neuronal activities and with hyperventilation the suppressions significantly increased. CONCLUSIONS: These results were compatible with clinical reports on the effectiveness of hyperventilation as a maintenance method under N2O anesthesia.     

A case of thoraco-amniotic shunt for congenital cystic adenomatoid malformation

Congenital cystic adenomatoid malformation (CCAM) is a congenital pulmonary anomaly, which may lead to fetal hydrops, pulmonary hypoplasia, and fetal or neonatal death. Recently, diagnosis and surgery for fetus have been improved. We experienced a case of CCAM, classified in Stocker class I, with a single cyst of about 5 cm in diameter. A 32 year-old pregnant woman had a fetus diagnosed as CCAM at 25 th gestational week. The thoraco-amniotic shunt placement using a modified double pig tail catheter was performed at 27 th gestational week under general anesthesia with 1% isoflurane in oxygen 2 l x min(-1) and nitrous oxide 4 l x min(-1), and 100 microg of fentanyl. Fetal movement was suppressed during surgery. This fetal therapy was effective and the cyst disappeared after surgery. The baby was delivered with caesarian section under spinal anesthesia with 0.5% bupivacaine 2.5 ml. On the next day, right lung lobectomy was accomplished under general anesthesia with fentanyl 0.2 mg and pancuronium 6.0 mg. Anesthesia with isoflurane, nitrous oxide, and fentanyl was useful for the fetal surgery of thoraco-amniotic shunt placement. Consequently, caesarian section and lung lobectomy were completed successfully.     

Staged surgical palliations for hypoplastic left heart syndrome with poor preoperative conditions

A 2.8 kg-female newborn diagnosed as hypoplastic left heart syndrome was transferred to our hospital after resuscitation against systemic circulatory failure due to closure of the ductus arteriosus. Her systemic circulation was stabilized after alprostadil (lipo-PGE1) and inotorpic agent infusion along with mechanical ventilation support. On admission, signs of a pulmonary high-flow and low systemic perfusion were evident. Impaired coagulation aspect was gradually noted. Because a surgical palliation with cardiopulmonary bypass was considered to be at high-risk, a bilateral pulmonary artery banding was indicated. Through a median sternotomy, the right and left pulmonary arteries were individually banded. The patient was continued on the same ventilation strategy. Cardiac, hepatic and renal dysfunctions were improved over next few days and the patient weaned from ventilatory support. She underwent combined Norwood stage I and II repair at 4 months of age with weight of 4.8 kg. Postoperative course has been uneventful and the patient is now followed up in preparation for Fontan operation.     

Anesthetic management for gastrectomy of a patient after coronary artery bypass graft with gastroepiploic artery

We report anesthetic management of an 80-year-old man who had received coronary artery bypass graft with the gastroepiploic artery 5 years before the present gastrectomy. Preoperative angiography did not show patency of the grafted gastroepiploic artery. He underwent partial distal gastrectomy under general anesthesia with isoflurane in oxygen-enriched air combined with epidural block. The gastroepiploic artery was severed after temporary clamping which did not produce evidence of myocardial ischemia. There was no postoperative cardiovascular event after the surgery.     

General anesthesia for a patient with pulmonary hypertension, bronchial asthma and obesity

The management of the patient with pulmonary hypertension is a challenge for the anesthesiologists because the risk of right-sided heart failure is markedly increased. We experienced a case of general anesthesia for a patient with pulmonary hypertension (mean pulmonary arterial pressure 39 mmHg), bronchial asthma and obesity. A 31-year-old woman was scheduled for arytenoid rotation for left recurrent nerve palsy. We applied routine monitors (noninvasive blood-pressure, five-lead electrocardiogram, pulse oximeter), and direct blood pressure monitoring through the radial artery. Anesthesia was induced with midazolam 4 mg, fentanyl 100 microg and sevoflurane 5%, and maintained with sevoflurane (1-2%) and nitrous oxide in oxygen. Surgery was completed in 100 minutes without any complications. We could successfully perform general anesthesia in a patient complicated by pulmonary hypertension, bronchial asthma and obesity, without invasive right-sided heart catheterization.     

Coronary embolism and subsequent myocardial abscess complicating ventricular aneurysm and tachycardia

A 62-year-old female experienced a ventricular aneurysm and tachycardia caused by coronary embolism from mitral valve endocarditis. The patient underwent endoventricular patch plasty and cryoablation concomitant with valve replacement and survived without any operative complications. Pathological examination suggested that abscess formation played an important role regarding the disruption of the ventricular wall and development of the ventricular aneurysm and tachycardia. In previous reports, a myocardial abscess caused by a septic embolism has only been diagnosed using postmortem examinations as colony growth around the capillary vessels in the myocardium. We considered that our operation was effective and feasible in such an occurrence.     

Rapid resolution of traumatic acute subdural haematoma in the elderly

Rapid resolution of acute subdural haematoma (ASDH) has rarely been observed. Two elderly patients with rapid resolution of ASDH are described. In the present cases, it was indicated that a mechanism of rapid resolution of ASDH was attributable to cerebrospinal fluid dilution and cerebral atrophy resulting from aging.