Dynamic changes in cortical NADH fluorescence and direct current potential in rat focal ischemia: relationship between propagation of recurrent depolarization and growth of the ischemic core.

Forty rats were subjected to 3 hours of focal ischemia by occluding the left middle cerebral and left common carotid arteries. The propagation of recurrent depolarization around the ischemic core was analyzed using direct-current potential and NADH (reduced nicotinamide adenine dinucleotide) fluorescence images by irradiating the parietal-temporal cortex with ultraviolet light. Based on histological evaluation at direct-current recording sites, the total time of depolarization causing 50% neuronal injury was estimated to be 18.2 minutes. The sites showing recurrent depolarizations resulted in 23 +/- 29% neuronal injury due to the short depolarization time, whereas the sites showing recurrent depolarizations and eventually persistent depolarization resulted in infarction. The NADH fluorescence images showed that recurrent depolarizations propagated along the margin of the ischemic core. In 85.9% of the recurrent depolarizations, the fluorescence disappeared without leaving any traces and did not affect the area of the ischemic core. However, in 47.5% of the animals, 14.1% of recurrent depolarizations merged with the ischemic core and increased the area by 6 +/- 4 mm(2). These findings suggest that recurrent depolarization increases the severity of neuronal injury but does not cause infarction by itself if persistent depolarization does not follow, and that the area of persistent depolarization is enlarged with 14.1% of recurrent depolarizations.     

Effect of nitroglycerin and nicardipine on ICG excretion during halothane anesthesia

We evaluated the effect of nitroglycerin and nicardipine on ICG excretion during halothane anesthesia in man. Induced hypotension with nitroglycerin during halothane anesthesia produced a significant prolongation in ICG excretion. No such significant prolongation occurred in the patients who received nicardipine. The results suggest that a reduction in hepatic blood flow during anesthesia may be much less in patients who receive halothane with nicardipine than in those who receive halothane with nitroglycerin.     

A case of cerebellar neuroblastoma

A three-year-old boy with a progressive history of headache, vomiting and ataxia in the course of 2 months, was admitted on August 1983, when he was lethargic. Neurological examination revealed dysphagia, scanning speech and tremor in the bilateral hand. CT scan showed a very large enhanced mass in the center of posterior fossa with central necrosis in it and the dilatation of whole ventricular system. Suboccipital craniectomy was immediately performed and the tumor that occupied the vermis and invaded into both cerebellar hemisphere was subtotally removed. Postoperative irradiation was well performed: 4140 rads to the whole brain and 3162 rads to the spinal cord. However, 5 months later, facial palsy in the left side and progressive ataxia became prominent. CT scan showed multiple enhanced masses in the left trigonum and right anterior horn of the lateral ventricles and in the left cerebellopontine angle. In spite of chemotherapy, the patient had a down-hill course, especially after the ventricular hemorrhage, and died on June 9th, 1984. Histologically, the tumor had a lobulated appearance with an aggregation of tumor cells encircled by vascular septae. The cells within lobules generally had vesicular nuclei, which were arranged in parallel row. Occasionally smaller hyperchromatic cells with scant cytoplasm were present along the vascular septae. Reticulin was present within the septa, but was not observed within the lobules. Scattered astrocytic cells and processes were identified within the lobules by the immunoperoxidase technique for GFAP. The fibrillary cytoplasmic processes within the lobules were stained by immunoperoxidase technique for neurofilament (68K).(ABSTRACT TRUNCATED AT 250 WORDS)     

An experimental study demonstrating the physiological polarity of the frog's utricle

The frog Rana nigromaculata was used as an experimental model. The utricle and its nerve were isolated with the anterior and the lateral semicircular canal ampullae in frog Ringer's solution. The utricular otoconia and the otoconial membrane were then carefully removed. The halved anterior canal cupula was next placed in the tip of a glass microelectrode, which was mounted on a micromanipulator. The cupula was placed in the center of either the medial or the lateral part of the macula and was moved toward or away from the striola along the axis vertical to the striola. When the medial part of the macula was stimulated, 5 micron of striolapetal cupular movement elicited an excitatory nerve discharge. When the lateral part of the macula was stimulated, the striolapetal stimulus likewise induced an excitatory response. These results indicate the existence of physiological polarity on the utricular macula.     

Traumatic posterior fossa hematoma

The traumatic posterior fossa hematoma was regarded as relatively rare thing, but recently, as the result of the prevalence of CT scanners, the number of reported cases is increasing. We report nine cases of traumatic posterior fossa hematoma. We divided into two categories: one was the acute epidural hematoma, the other was the acute subdural hematoma with cerebellar contusion. Five were cases of the acute epidural hematoma, three were cases of the acute subdural hematoma with cerebellar contusion and a case had both an epidural and a subdural hematoma. All the cases had struck the occipital region and had the occipital bone fracture. The prognosis of the five cases of the acute epidural hematoma was excellent, but that of the four cases of the acute subdural hematoma with cerebellar contusion was poor and they all died inspite of the removal of the hematoma executed in three cases. We estimated that the hitting forth was extremely strong in cases of the subdural hematoma with cerebellar contusion, and that the momentary deformity of the occipital bone might injure the cerebellum directly. Once a hematoma was produced in the posterior fossa, it oppresses the brainstem and causes the acute hydrocephalus, so the state of consciousness and respiration deteriorate suddenly. In cases of the acute epidural hematoma, appropriate surgical intervention could save the patients and resulted in good outcome. But in some cases of the fulminant type acute epidural hematoma of the posterior fossa caused by tearing the sinuses, though we have not experienced, patients die before the diagnosis and treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased heme oxygenase-1 gene expression in the livers of patients with portal hypertension due to severe hepatic cirrhosis

Surgical bleeding associated with splanchnic hyperaemia due to portal hypertension complicates the anaesthetic management of hepatic transplantation. Although the mechanism(s) of portal hypertension are not fully understood, carbon monoxide, a product of the heme oxygenase (HO) reaction, is thought to be one of the endogenous vasodilators in the liver. In this study, the expression of mRNA encoding inducible HO isozyme (HO-1) in the livers of patients with portal hypertension undergoing hepatic transplantation was determined in comparison with those without portal hypertension. HO-1 mRNA levels were significantly greater in the portal hypertension group than in the group without portal hypertension. In contrast with HO-1, the gene expression of non-specific delta-amino-levulinate synthase (ALAS-N), which is down-regulated by heme in the liver, was the same in both groups. These results suggest that HO-1 is up-regulated through heme-independent stimuli according to the development of portal hypertension, and that induced HO-1 plays a pathophysiological role in portal hypertension through carbon monoxide production.     

Effects of enalapril maleate (MK-421) on renovascular hypertension

The effects of enalapril maleate (MK-421), a new angiotensin converting enzyme inhibitor, were studied on 5 patients with renovascular hypertension (RVH) due to unilateral renal artery stenosis. The therapeutic dosage was increased when the blood pressure (BP) was not controlled for more than 3 days. Blood sampling was performed before, and 5 hr and 24 hr after the first administration, and on the 3rd day with each dosage. The BP was normalized on 5 mg/day in 1 case, 10 mg in 1 case, 20 mg in 2 cases, and 40 mg plus mefruside in 1 case. Plasma renin activity (PRA) was significantly increased after 5 hr and recovered after 24 hr with 2.5 mg of the enalapril maleate, when the BP was not affected. This indicates that the increase in PRA is likely due to the reduced negative feedback of angiotensin II. When the blood pressure was lowered, PRA was increased and plasma aldosterone concentration (PAC) was decreased significantly. This rise of PRA may depend not only on the reduced negative feedback but also on the fall of BP. It is also considered that the PAC was decreased through the decrease in plasma angiotensin II. A fall of the glomerular filtration rate in one case and also a fall of the perfusion of the kidney of the stenotic side in another case were observed by radioisotope renograms. MK-421 administration was a useful treatment for RVH, and clearly normalized the BP of all the patients studied. However, there was a risk of a fall of renal function on the stenotic side due to the decrease in perfusion pressure.     

Five cases of ectopic liver and a case of accessory lobe of the liver

Five cases of ectopic liver, two of retro-peritoneal cavity and three of gallbladder, and a case of accessory lobe of the liver, are reported. One of these cases with ectopic liver was accompanied by multiple cysts of the liver and kidney, and biliary microhamartoma, which was observed laparoscopically on the surface of the main liver and histologically proven in the ectopic liver.