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Biomedical subjects

H Handa

Publications and source records attributed to H Handa.

At least 397 records · Page 22Linked to original sources
PubMed1984

[Postoperative convulsion on the long-term follow-up in aneurysmal surgery].

There is some controversy in the long-term use of anticonvulsants for all postoperative cases. In order to establish the appropriate use of anticonvulsants, postoperative convulsion was studied concerning its incidence, onset and relevance with site of aneurysm, focal neurological deficits, CT findings and anticonvulsants in 169 cases of aneurysmal surgery under surgical microscope in the period of 1 to 11 years postoperatively. Convulsion was noted in 26 cases among 169 cases, and convulsion more than 1 week after operation (late convulsion) was noted in 20 cases (11.8%). Onset of late convulsion was most common during 6 to 12 months after operation and in 90 percent of cases it was developed within 2 years. In 2 of 5 cases with convulsion within 1 week late convulsion developed. On the site of aneurysm, middle cerebral artery aneurysmal cases showed high occurrence (20.5%) without statistical significance. Focal neurological deficit was one of predisposing factors for late convulsion with statistical significance (29.8%). On CT, 8 of 9 studied cases of late convulsion showed focal low density area involving cortex, although this was also noted in the cases without convulsion. Occurrence of late convulsion was significantly low (6.5%) in the cases without anticonvulsants. This suggests that there is low risk of late convulsion in the cases of uneventful postoperative course, no focal neurological signs and no abnormal findings on CT, even without anticonvulsants. Late convulsion occurred in about one third of cases treated with anticonvulsants. This is probably due to high risk and poor control of anticonvulsants plasma levels in some cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Arteriovenous malformations of the cervical spinal cord--with special reference to CT study].

Arteriovenous malformation (AVM) of the cervical spinal cord has been known to constitute 5-13% of all spinal AVMs. In contrast to the AVMs located in thoracic or thoraco-lumbar regions, cervical AVM has several characteristic features such as preponderance in younger generation, high incidence of subarachnoid hemorrhage, intramedullary location of the nidus usually fed by the anterior spinal arterial system. We reported three cases of cervical AVMs, which located intramedullary at the levels of C4-C6, C1-C4 and C1-C2, respectively. Although selective angiography (vertebral artery, thyrocervical artery, costocervical artery) was essential for the diagnosis of these lesions, computerized tomographic (CT) study with both intrathecal injection of metrizamide and intravenous infusion of contrast material (dynamic and static study) was found to be extremely advantageous in detecting the topography of AVMs in the concerned horizontal planes of the spinal cord. Removal of AVM was given up in one case because of its possible involvement of the anterior spinal artery and central artery shown by CT scan. Removal of AVMs were performed in other two cases. A lateral approach was tried in one case with the AVM located in C1-C2 level, in which CT scan revealed not only an intramedullary but the associated extramedullary AVM in ventrolateral surface of the spinal cord. This operative approach was found to involve less bone removal and markedly reduce spinal cord manipulation necessary to deal with ventrally situated high cervical lesions, compared with a posterior approach with laminectomy.

Adult↗
PubMed1984

[Synergism of hyperthermia and hematoporphyrin derivative].

Much attention has been given to the photoradiation therapy, since its mechanism of effect is thought to be due to the cytotoxicity of singlet oxygen produced from hematoporphyrin derivative (HPD) by the light. We studied the effects of hyperthermia (HT) on cultured cells (T1) of ethylnitrosourea induced rat brain tumor which had uptaken HPD, because the extent of photopenetration is limited and the absorbed light is converted to heat. We used the T1 cells preincubated in Eagle MEM with 10% FCS and 2 micrograms/ml HPD, and estimated the cell survival by the colony formation using soft agar overlayer method. Synergistic effects of HT and HPD were recognized at the temperature over 41.5 degrees C-HT, suggesting that combined HT and HPD therapy could be a new promising technique. In these experiments, an increased cell proliferation was observed after temporary suppression by "insufficient hyperthermia" at 41.5 degrees C. This is a kind of rebound phenomenon, which has an important clinical implication. We should pay attention not only to the cell damage by HT but also to the outcome of the therapy which have received insufficient HT.

Animals↗
PubMed1984

[Regional change of brain energy metabolism and catecholamine in the early stage of experimental cerebral ischemia--histochemical study].

Ischemic change of cerebral energy metabolism and catecholamine have already been discussed largely using biochemical quantitative assay. However, regional change and their correlation are not well understood. In the present study, the ischemic regional change of cerebral energy metabolism and catecholamine were investigated in gerbils and histochemical method. Adult either sex mongolian gerbils, weighing 50-100 g, were anesthetized with ether and the left carotid artery was ligated. After observation of clinical symptoms, the brain was frozen in situ by pouring liquid N2 after 30 min and 60 min of ischemic insult. The frozen brain was sectioned with precooled saw in the coronal plane. The brain section were placed in liquid N2 bath and illuminated with 366 nm light (UV) from a 200 watt mercury lamp and Corning filter 5840. NADH fluorescence was recorded photographically through Corning filter 3387 and 5562. Also UV reflectance was recorded through Corning filter 5840 to observe quenching effect of hemoglobin. Regional change of catecholamine was observed in the same frozen brain processed with Falck-Hillarp method. According to neurological abnormalities following left carotid ligation, animals were divided into three groups; symptomatic, borderline and asymptomatic. The intensity and distribution of tissue NADH fluorescence were closely correlated to the clinical symptoms. In the symptomatic group, both in 30 min and 60 min of ischemia, homogeneously and markedly increased fluorescence was observed in the ipsilateral temporal cortex, caudate nucleus, hypothalamus and dorsolateral thalamus. Columnar mild increase of NADH fluorescence was seen in the ipsilateral parietal cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Sequence requirement for transcription in vitro of the human corticotropin/beta-lipotropin precursor gene.

Using HeLa whole cell extracts, we have demonstrated that transcription in vitro of the cloned human and bovine corticotropin/beta-lipotropin precursor genes is initiated accurately and efficiently. DNA sequences required for promoter function have been assessed by using a series of 5'-deletion mutants of a fusion gene that contains the 5'-flanking sequence and capping site of the human corticotropin/beta-lipotropin precursor gene and the structural sequence of the herpes simplex virus thymidine kinase gene. The results obtained have shown that the region between 22 base pairs and 35 base pairs upstream from the capping site is essential for the correct and efficient transcriptional initiation in vitro. Thus, the 'TATA box' present in this region seems to be the main promoter element for transcription of the human corticotropin/beta-lipotropin precursor gene in the HeLa cell-free system. We have also developed a transcription system in vitro from the corticotropin-producing mouse pituitary tumor cell line AtT-20 in culture. Deletion mapping of the fusion gene promoter has indicated that the 'TATA box' region is required for the accurate and efficient transcriptional initiation in this system as well. Characteristic of this system is that the deletion of the sequence lying between 53 base pairs and 59 base pairs upstream from the capping site increases the transcriptional efficiency. Because this effect is observed in the AtT-20 cell-free system, but hardly in the HeLa cell-free system, it seems reasonable to assume that the interaction of this upstream sequence with some factor(s) in the AtT-20 cell extract is responsible for the modulation of transcription of the human corticotropin/beta-lipotropin precursor gene.

Adrenocorticotropic Hormone↗
PubMed1983

Inhibition of adenovirus early region IV transcription in vitro by a purified viral DNA binding protein.

Adenoviruses depend on cellular mechanisms for the decoding of their genetic information, and so provide a useful and simple model system for the investigation of mammalian gene expression. The five regions transcribed early in adenovirus infection are termed EIa, EIb, EII, EIII and EIV. We report here that the primary product of the EII region, a 72,000 molecular weight DNA-binding protein (DBP), specifically represses transcription from the EIV promoter in an in vitro transcription system. Single-stranded DNA binds to the DBP with high affinity, and as a result inhibits its repressor activity. Our data extend previous genetic evidence that the DBP represses EIV transcription in vivo, and suggest that it acts directly by suppressing transcription from the EIV promoter.

Adenoviridae↗
PubMed1983

Krypton-81m single photon emission tomography and the collateral circulation in carotid occlusion: the role of the circle of Willis and leptomeningeal anastomosis.

Cerebral perfusion images were investigated in patients with carotid artery occlusion, using single photon emission computed tomography with the infusion of krypton-81m into the internal, common carotid and vertebral arteries. The contribution of the circle of Willis and cerebral cortical anastomoses to the maintenance of adequate blood supply into the involved hemisphere was analysed. It was concluded that the cerebral perfusion image is superior to angiography in evaluating collateral circulation, and in the case of carotid occlusion, the circle of Willis is important in preventing infarction in the territory of the perforating arteries, while the cerebral cortex mainly receives its blood supply through the cortical leptomeningeal anastomoses, illustrating the major role of the leptomeningeal anastomosis as a collateral channel.

Adult↗
PubMed1983

Characterization of alpha adrenoceptors in pial arteries of the bovine brain.

When attempting to characterize the nature of adrenoceptors in bovine pial arteries, we found specific 3H-yohimbine binding was saturable, reversible and of high affinity (KD = 18.3 +/- 1.2 nM) with a Bmax of 687 +/- 27 fmol/mg protein (N = 4). On the other hand, there was no specific 3H-prazosin binding in these tissues. Scatchard and Hill plot analyses of specific 3H-yohimbine binding indicated one class of binding sites. From kinetic analyses of the data, association and dissociation rate constants of 1.6 +/- 0.3 X 10(7) M-1min-1 and 0.51 +/- 0.04 min-1, respectively, were calculated (N = 3). The dissociation constant from the equation KD = K-1/K+1 was 35.7 +/- 7.6 nM, such being in good agreement with the KD value estimated from Scatchard plots. Specific binding of 3H-yohimbine was displaced effectively by alpha 2 adrenergic agents and less effectively by alpha 1 adrenergic agents or beta adrenergic agents. Ki values for adrenergic drugs of 3H-yohimbine binding were as follows: yohimbine, 25 nM; clonidine, 260 nM; methoxamine, 6.8 microM; propranolol, 8.7 microM; prazosin, 21 microM; phenylephrine, 22 microM; noradrenaline, 27 microM; adrenaline, 66 microM; isoproterenol, 3,300 microM. These results indicate that alpha adrenoceptors in the bovine cerebral arteries can be classified as the alpha 2 subtype.

Animals↗
PubMed1983

Rat pituitary adenoma and hyperplasia induced by caffeine administration.

The effect of caffeine by oral administration on female Wistar rats was studied for 12 months. High concentrations (2000 micrograms/mL) of caffeine caused a decrease in body weight and an increase in the weight of the pituitary gland in these rats. Increased pituitary weight was caused by the growth of a pituitary adenoma or hyperplasia. Pituitary adenomas and instances of hyperplasia were found in 27 of the 40 rats in the caffeine group, compared to 9 of the 30 rats in the control group. The histologic classification used was microadenoma, papillary (or sinusoidal) macroadenoma, and diffuse macroadenomas. These adenomas appeared to be endocrinologically nonfunctioning.

Adenoma↗
PubMed1983

Choriocarcinoma arising from the pituitary fossa with extracranial metastasis: a review of the literature.

Since Askanazy's first report on a case of primary intracranial choriocarcinoma in 1906, more than 60 cases have been reported so far. We add to that a case of intrasellar choriocarcinoma with suprasellar extension: A 12-year-old girl showed cranial nerve palsies, hypopituitarism, and abnormally high titers of human chorionic gonadotropin (HCG) in blood and in cerebrospinal fluid (CSF). She died 3 months after surgery. At autopsy, an intra- and suprasellar choriocarcinoma, which penetrated through the clivus into the cerebellopontine angle and metastasized remotely to the lungs, was confirmed. This rare case is presented with a thorough review of the literature.

Adolescent↗
PubMed1983

Nonsurgical treatment of huge suprasellar germinoma.

A case describing a huge, suprasellar germinoma with subfrontal extension that produced striking emaciation of the patient as an initial symptom is discussed. Diagnosis of germinoma was made on the basis of a computed tomography scan and cytology of the ventricular fluid. The tumor responded well to radiation treatment, which may indicate that it is not always necessary to reduce tumor bulk by direct surgical intervention before radiation therapy.

Adolescent↗
PubMed1983

The size of cerebral aneurysms in relation to repeated rupture.

The size of ruptured cerebral aneurysms in 407 cases were studied angiographically in relation to the number of times of rupture. The size of aneurysms was not influenced by the number of clinically documented episodes of bleeding. Patients with long-term clinical courses of untreated ruptured aneurysms had significantly larger aneurysms than in the general patient population. The result indicates that aneurysmal enlargement is not closely related to their rupture when considering aneurysmal growth in general. The mechanism of growth of cerebral aneurysms is discussed.

Cerebral Angiography↗