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Biomedical subjects

J Handa

Publications and source records attributed to J Handa.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Ca++ antagonist and acute brain ischemia: effects of nilvadipine and nicardipine on middle cerebral artery occlusion in rats].

Effects of calcium antagonists, Nicardipine and Nilvadipine, on neurologic deficits and size of infarct were studied in the rat middle cerebral artery (MCA) occlusion model. Each drug was administered immediately after induction of ischemia, and neurologic grade was evaluated 1 to 24 hours after MCA occlusion. At 24 hours post-occlusion, size of the infarct was compared with that of the control group. In addition, evolution of cerebral infarction was studied at 6 hours and 12 hours post-occlusion by magnetic resonance imaging (MRI). In the Nilvadipine-treated group, neurologic deficits improved more rapidly and the size of infarct was significantly smaller than in the Nicardipine-treated group. MRI showed a progressive extension of cortical infarct in the untreated rat, whereas the infarct size remained unchanged in the Nilvadipine-treated rat. These results suggest the potential therapeutic usefulness of calcium antagonist for acute cerebral ischemia.

Acute Disease↗
PubMed1991

Studies of variant palatal rugae in normal and corticosteroid-treated mouse embryos.

Fourteen- and 15-day mouse embryos treated with triamcinolone on day 11 of gestation were examined for the presence of variant rugae. Nontreated mouse embryos served as controls. Variant rugae found were classified into five types. All five types of variations (bifurcation, division, supernumerary, shortness and cross) were observed in triamcinolone-treated embryos, and shortness was most frequently seen. Supernumerary, bifurcation and division were ranked next, following by cross. Variant, rugae, except the cross, were also observed in non-treated embryos in low frequencies, but more than one-half of them were the bifurcation of the second ruga. Divided rugae ranked next, and supernumerary and shortness were found occasionally. Except for the bifurcated and supernumerary rugae, the greater part of the variant rugae were found in the fifth and fourth ruga in the triamcinolone-treated groups and in the fifth ruga in the nontreated groups. As the incidence of variant rugae in the triamcinolone-treated embryos was significantly higher than that in the nontreated, it was regarded as one of the changes induced by the corticoid. Based on the characteristic features of the rugal region, it is speculated that the formation of variant rugae is associated with the disturbance of normal epithelial-mesenchymal interaction which may be controlled by the nerve fibers appearing at the time of rugal formation. The relationship between the increased appearance of variant rugae and the failure of palatal shelf elevation was examined, but no direct evidence was obtained.

Abnormalities, Drug-Induced↗
PubMed1991

Mechanism of mutism following the transcallosal approach to the ventricles.

Transient mutism has been known as a common manifestation following callosotomy for medically intractable epilepsy, but its cause has not been clearly elucidated. In this paper, we report three cases of mutism following a transcallosal approach to tumours in the lateral and third ventricles and retrospectively analyze the surgical, neurological and radiological features which may suggest the cause of this type of mutism. Mutism may be a result of division of the corpus callosum. Suppression of the limbic system caused by lesions in the anterior cingulate gyrus, septum pellucidum, and fornix may have been of importance in at least two of these three cases. Impairments of the supplementary motor cortex, thalamus and basal ganglia may also be factors reducing speech production. The mechanism of such transient mutism seems to be a complex of two or more of these factors, and their combinations may be different from one case to the other.

Adult↗
PubMed1991

Primary carcinoma of the choroid plexus in the lateral ventricle.

Primary carcinomas of the choroid plexus are rare and occur more frequently in children than in adults. They have been posing a problem in their differential diagnosis from benign papilloma of the choroid plexus, ependymoma, and metastatic tumors of extracranial origin. A case of a 31-year-old woman with primary carcinoma of the choroid plexus in the trigone is reported. Electron microscopic and immunohistochemical studies are helpful, but not decisive yet, to reach the diagnosis. The literature is reviewed.

Adult↗
PubMed1991

Reactivity to vasoactive agents of canine basilar arteries exposed to experimental subarachnoid hemorrhage.

Autologous blood was injected into the cisterna magna of mongrel dogs twice with an interval of 48 hours. They were killed 3 days, 1 week, or 4 weeks after the first injection of blood, and helical strips of the basilar artery were prepared. Contractions induced by 5-hydroxytryptamine, noradrenaline, prostaglandin F2 alpha, and oxyhemoglobin were significantly potentiated. Relaxations caused by nicotine, K+, arachidonic acid, and prostaglandin I2 were suppressed, but the relaxant response to calcium ionophore A23187 and substance P did not change significantly. These results suggest that contractions mediated via activation of alpha, 5-hydroxytryptamine, and prostaglandin F2 alpha receptors are potentiated, and relaxations caused by stimulation of vasodilator nerves and by endogenous and exogenous prostaglandin I2 are attenuated in dog basilar arteries exposed to subarachnoid clot. On the other hand, certain relaxations possibly mediated by endothelium-derived relaxing factor do not appear to be significantly influenced.

Animals↗
PubMed1991

Effects of the calcium antagonist nilvadipine on focal cerebral ischemia in spontaneously hypertensive rats.

We studied the efficacy of preischemic and postischemic systemic treatment with a new calcium antagonist nilvadipine in a permanent focal cerebral ischemia model of spontaneously hypertensive rats. Rats that underwent microsurgical middle cerebral artery occlusion were blindly assigned to a single intraperitoneal injection of nilvadipine (0.32 mg/kg) or the same amount of polyethylene glycol either 15 minutes before, immediately after, 1 hour after, or 3 hours after occlusion of the left middle cerebral artery. Neurologic conditions of rats were closely examined, and rats were killed 24 hours later. Removed brains were sliced coronally, stained with triphenyltetrazolium chloride, and the size of infarct was determined. Although no neurologic improvements were observed in the treated rats, the area of infarcts was significantly reduced in the groups treated before, immediately after, and 1 hour after occlusion of the middle cerebral artery. Treatment started 3 hours after occlusion was ineffective.

Animals↗
PubMed1991

Nilvadipine, a new calcium channel blocker, reduces ischemic brain injury in rats.

The effects of nilvadipine, a dihydropyridine type calcium channel blocker, on cerebral infarction induced by focal brain ischemia was studied in rats. The area of infarction was measured 24 hr after occlusion of the middle cerebral artery (MCA) in spontaneously hypertensive rats using triphenyltetrazolium chloride. Nilvadipine, given immediately after MCA occlusion, reduced the area of infarction significantly at doses of 0.32 mg/kg (i.p.) and 3.2, 10 and 32 mg/kg (p.o.). Nicardipine suppressed the area of infarction at a dose of 32 mg/kg (p.o.). The results suggest that nilvadipine is effective against ischemic brain injury.

Animals↗
PubMed1991

Intraoperative monitoring of somatosensory evoked potentials in patients with cerebral aneurysm--correlation between central conduction time and postoperative neurological status.

Somatosensory evoked potentials (SEPs) were monitored during 55 aneurysm procedures in 49 patients to investigate the relationship between central conduction time (CCT) and neurological status in the immediate postoperative period. Significant CCT prolongation was observed in 15 cases. The postoperative neurological status deteriorated in nine of the 15 cases, compared with three of 40 cases without appreciable CCT changes. This difference was significant at p less than 0.05. The CCT prolongation was ascribable to temporary vascular occlusion in half of the cases. Intraoperative SEP monitoring is useful in predicting neurological morbidities in the immediate postoperative period in patients with cerebral aneurysm.

Adult↗
PubMed1991

[Pulmonary edema caused by cardiac ischemic attacks in cases with or without minimal myocardial infarction].

We report cases of angina pectoris or minimal acute myocardial infarction accompanied by pulmonary edema, which were retrospectively studied with regard to their clinical characteristics, prognosis and treatment. Sixteen patients, 5 males and 11 females with a mean age of 72.6 years, admitted to the Cardiovascular Center of Sendai between January 1986 and June 1989, were studied. Ten had previous myocardial infarction. Hypertension, chronic renal failure and diabetes mellitus were found in 10, 7 and 7 patients, respectively. Electrocardiograms during cardiac ischemic attacks showed ST elevation in 8 and ST depression in the other 8 patients. Coronary arteriography which was performed in 6 patients revealed three-vessel disease in 5, and two-vessel disease in one. Mechanical ventilation was indicative of 7, and intraaortic balloon counterpulsation in 2 patients. Coronary artery bypass graft surgery was performed for 3 patients. All patients recovered from pulmonary edema and were discharged. During the mean 15-month-follow-up period, 8 patients died. The causes of death were sudden cardiac death in 3, acute myocardial infarction in one, congestive heart failure in one, post-surgical death in one, and non-cardiac death in 2.

Aged↗
PubMed1990

Periventricular spread of malignant lymphoma: report of two cases.

Two cases of intracranial malignant lymphoma with an atypical feature on CT scan are reported. Both patients presented subacute progressive dementia. CT scan showed high density lesion extending all the way along the ventricular wall, which was homogeneously enhanced and resembled severe ventriculitis. Differential diagnosis on CT scan is discussed.

Aged↗
PubMed1990

Central neurocytoma: report of a case.

Central neurocytoma is a rare intraventricular tumor recently accepted as a clinicopathological entity. A 21-year-old female was admitted with three-year history of episodic headaches and vomiting, and with rapid deterioration of her left vision over two weeks prior to admission. Computed tomography (CT) scan revealed a marked hydrocephalus and an isodense, mildly enhancing mass in the left lateral ventricle. On magnetic resonance imaging (MRI) scan, T1-weighted images revealed an intraventricular mass of slightly high intensity signal, which contained areas of low intensity signal representing multiple intratumoral cysts. The tumor showed a minimal enhancement with Gd-DTPA. A diagnosis of central neurocytoma was confirmed by an electron-microscopic study of a surgical specimen; there were numerous neuronal cell processes containing microtubules and dense-core vesicles, and a few small intercellular junctions were also identified.

Adult↗
PubMed1990

[Meningiomas in the elderly: analysis of 34 patients].

We have operated on 82 patients with intracranial meningiomas in the past 10 years. They ranged in age from 6 to 80 (mean 56.3), 59 patients were female and 23 were male. Thirty-four patients were 60 years of age or older. Of 82 patients, follow-up examination was possible in 71, with a mean follow-up period of 3 10/12 years. Pattern of clinical onset, location of tumors, and histology were compared among groups of approximately 59 years, 60-69 years, and 70 years approximately in age. Of 71 followed-up patients, 11 (15.5%) had expired. Operative mortality in patients aged 60 or older in this series, however, was low at 2.9%.

Aged↗
PubMed1990

[Pituitary adenoma associated with neurofibromatosis: case report].

A case of pituitary adenoma associated with multiple neurinomas in the central nervous system was presented. A 52-year-old man was referred to us for surgical treatment of an intradural extramedullary cervical cord tumor. He had been operated on for a cauda equina tumor when he was 43 years old, and again for a glossopharyngeal neurinoma at 49 years of age. His brother expired in childhood, and had multiple subcutaneous nodules. The patient had been complaining of left leg pain, left shoulder pain, and hypesthesia of the right leg and foot. Examination showed 6th cervical nerve root sign. MRI revealed a well-circumscribed extramedullary tumor at the C5 level, and, in addition, incidentally showed an intra- and supra-sellar tumor which was isointensity on T1 weighted and high intensity on T2 weighted images. Myelography showed multiple extramedullary tumors in the lumbar region. Endocrinological study revealed an increased serum prolactin level (818.0ng/ml). The patient had neither café au lait spots nor subcutaneous nodules. A neurinoma of C6 root was totally removed and chromophobe pituitary adenoma was partially removed through a transsphenoidal approach. Neurofibromatosis is known to be associated with many kinds of tumors in the central nervous system. They are usually neurinomas, meningiomas or gliomas, and association of pituitary adenomas has been reported in only three cases, one of which being a prolactin secreting adenoma. Coexistence of multiple primary brain tumors has been also reported apart from phakomatosis. The most common combination is association of glioma and meningioma, and it is probably incidental coexistence due to their high frequency.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma, Chromophobe↗
PubMed1990

Rathke's cleft cyst: computed tomographic scan and magnetic resonance imaging.

Three patients with histologically proved Rathke's cleft cysts (RCCs) were evaluated with magnetic resonance imaging (MRI) and computed tomographic (CT) scan. Thirteen cases reported in the previous literature were also reviewed to evaluate the MRI features of RCCs and to compare them with CT features. The RCCs had various patterns of signal intensities on T 1-weighted and T 2-weighted MRI. The cysts were well-circumscribed and mainly in the sella turcica extending to the suprasellar cistern with minimal mass effect. Ten of sixteen cases had homogeneous cysts, and six had heterogeneous cysts. The CT scans showed the cysts as low or isodensity, well-demarcated lesions in the sella, that did not enhance with a few exceptions in which a thin ring enhancement was seen. MRI is superior to CT in the evaluation of the RCC, and is particularly useful in surgical planning, although MRI has a limitation on the specific, analytic description of the cyst contents.

Cysts↗
PubMed1990

Sequential changes of cerebral blood flow after aneurysmal subarachnoid haemorrhage.

A total of 226 measurements of cerebral blood flow (CBF) were performed in 96 postoperative patients with aneurysmal subarachnoid haemorrhage (SAH). The global CBF was significantly reduced in the first week after SAH, and the extent of the CBF reduction was less in the patients with good outcome than in those with fair/poor outcome. The good outcome patients showed a progressive increase in CBF in the following 3 weeks. Although the CBF decreased further in the second week in some of those patients, it turned to a steady increase thereafter. On the other hand, in the fair/poor outcome patients CBF remained far below the normal control value for at least 3 months after SAH. When looking into the effect of age on CBF in the patients with good outcome, those in their thirties and forties had a significantly reduced CBF during the first 2 weeks, whereas in those in their fifties and sixties a significant reduction persisted for 3 months to 1 year after SAH. Management of the older patients needs special attention even if they are apparently in good clinical condition, since the CBF threshold to ischaemia is diminished.

Adult↗
PubMed1990

Interface between the meningioma and the brain on magnetic resonance imaging.

Magnetic resonance imaging of 31 meningiomas in 29 patients was retrospectively reviewed and compared with pathologic specimens in 25 tumors to investigate how magnetic resonance imaging could delineate a tumor-brain interface. The thick, collagenous connective tissue, which was seen around four tumors, was shown as a low signal intensity rim on both a T1-weighted image and a T2-weighted image. A rim of low signal intensity on a T1-weighted image and high signal intensity on a T2-weighted image most likely represented cerebrospinal fluid space: this finding was seen around eight tumors. No distinct rim could be identified in five tumors. Of these five, two tumors grew invasively into the brain. Although mixed features predominated in meningiomas, magnetic resonance imaging could well delineate a tumor-brain relationship in most of the cases.

Adult↗
PubMed1990

Magnetic resonance imaging with aneurysmal subarachnoid hemorrhage: comparison with computed tomography scan.

Magnetic resonance studies of 27 consecutive preoperative and 33 postoperative patients with cerebral aneurysm and subarachnoid hemorrhage were reviewed. Magnetic resonance imaging using a 0.5- or 0.22-Tesla unit was at least as accurate as computed tomography scan for detection of acute subarachnoid hemorrhage. Magnetic resonance imaging was superior to computed tomography scan for demonstrating blood in the ventricles or posterior fossa subarachnoid space, transependymal migration of the cerebrospinal fluid, and several kinds of iatrogenic intracranial pathologies in postoperative patients. Ischemic lesions, particularly fresh lesions caused by delayed cerebral vasospasm, were much better shown on magnetic resonance imaging than on computed tomography scan. Nonferromagnetic Sugita clips caused significant artifacts, but the area of artifacts was consistently smaller, and a reasonable evaluation of structures relatively closer to the clip was possible with magnetic resonance imaging rather than computed tomography scan.

Adult↗