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Biomedical subjects

H Kamiyama

Publications and source records attributed to H Kamiyama.

106 records · Page 6Linked to original sources
PubMed1985

[Angiographic analysis of the middle cerebral artery in cerebral aneurysms--its branching pattern and so-called vascular anomalies].

UNLABELLED: Branching patterns of middle cerebral artery (MCA) were angiographically analyzed in 704 cases with cerebral aneurysms. The mean age was 53 years old and the men-to-women ratio was 1.1. In addition, 13 vascular anomalies of MCA were reported and their correlation with the occurrence of cerebral aneurysm was studied. RESULTS: MCA branching patterns were classified in 6 types. Each type was further studied by dividing into 2 subgroups, namely one with MCA aneurysms at their side and the other without MCA aneurysms. There were no differences statistically between each two groups. Vascular anomalies were consisted of 5 duplications of MCA, 4 fenestrations, 3 accessories and one case of combination of duplication and accessory in the same side. Duplications and accessories did not have any evidence of developing aneurysm more frequently at their bifurcation than any one of normal MCA branching patterns. So we concluded that duplications and accessories should be thought to have similar meanings with the ordinary branching patterns of MCA in the occurrence of aneurysms. A postmortem case of accessory MCA without aneurysm revealed that the origin of the anomaly was pathologically normal. We suggested that the origin of accessory MCA could both be an enlarged Heubner artery and a rare branching pattern of MCA. The fenestration should be a true anomaly but at this point we do not have any suggestive clue for that. Finally, we thought that the combination of duplication and accessory in a single MCA was very rare morphologically, and worthwhile to report.

Adult↗
PubMed1985

[Angiographic analysis of the internal carotid-vertebrobasilar system with cerebral aneurysms--with special interest in the morphological aspect including so-called vascular anomalies].

In a series of 704 aneurysm patients who were admitted to the Research Institute for Brain and Blood Vessels-AKITA during the last 9.5 years (from October, 1974 to March, 1983), angiographic features of the internal carotid-vertebrobasilar system and related vascular anomalies were analyzed with reference to the site of aneurysms. The age distribution was from 20 to 78 years (mean age 53 years) and the men to women ratio was 1:1.1. The total number of the aneurysms was 866. The site distribution of aneurysms consisted of 230 (27%) anterior communicating, 269 (31%) middle cerebral, 282 (38%) internal carotid, 54 (6%) anterior cerebral, 45 (5%) vertebrobasilar and 6 other arteries. More than one aneurysm were found out in 137 cases. The total number of performed cerebral angiograms was 1840, in which right carotid arterial angiograms were 652, left carotid 644 and vertebral 544. Angiographic features of the posterior communicating arteries (Pcom) with or without internal carotid-Pcom aneurysm were compared one side with the other, statistically revealing that the morphological factor of the Pcom did not play an important role in the development of the cerebral aneurysm at this portion. Anomalies of the posterior cerebral artery directly originated from the internal carotid artery were found in 9 cases, and three of them had the aneurysm at their origin. Anomalous carotid-basilar anastomoses were seen in 7 cases, namely 6 persistent primitive trigeminal arteries (2 of them were PTA variants) and one persistent primitive hypoglossal artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Angiographic analysis of the anterior cerebral arteries with cerebral aneurysms--with special interest in the morphological aspect including so-called vascular anomalies].

In a series of 704 aneurysm patients who were admitted to the Research Institute for Brain and Blood Vessels-AKITA for the last 9.5 years (from October, 1974 to March, 1983), angiographic features of the anterior cerebral arteries and related vascular anomalies were analyzed with reference to the site of aneurysms. The age distribution was from 20 to 78 years (mean age 53 years), and the men to women ratio was 1:1.1. The total number of aneurysms was 866. The site distribution of aneurysms consisted of 230 (27%) anterior communicating, 269 (31%) middle cerebral, 282 (38%) internal carotid, 54 (6%) anterior cerebral, 45 (5%) vertebrobasilar and 6 other arteries. More than one aneurysm were found out in 137 cases. The total number of performed cerebral angiograms was 1840, in these right carotid arterial angiograms were 652, left carotid 644 and vertebral 544. Cases were divided into two groups, namely one who had the anterior communicating artery (Acom) aneurysm and the other who had not. Angiographic calibers of A1 portion (proximal portion of the anterior cerebral artery) were compared statistically between these two groups. As a result, three points as below were clarified in this series. 1) The Acom aneurysm group showed the significant asymmetry of A1 (p less than 0.005) compared to the other cases. 2) The left A1 portions were significantly dominant (p less than 0.05) to the right in the Acom aneurysm group. 3) Angiographic hypoplasias and aplasias of A1 were found in the Acom aneurysm group more frequently than in the other with statistical significance (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Pharmacokinetics of nicorandil, a new coronary vasodilator, in dogs.

The kinetic disposition of nicorandil, N-[2-( nitroxy )ethyl]-3- pyridinecarboxamide (1), and its main metabolic product, N-[2-(hydroxy)-ethyl]-3- pyridinecarboxamide (II), was studied after administering intravenous and oral doses (2.5 mg/kg) of nicorandil to the same beagle dogs. The plasma concentrations were measured using a high-performance liquid chromatographic method. The pharmacokinetic data derived from intravenous administration of nicorandil were: t1/2, 0.73 plus/minus 0.11 h; Vdarea , 0.67 plus/minus 0.04 L/kg; and total plasma clearance, 13.50 plus/minus 1.05 mL/min/kg. After oral administration, nicorandil was rapidly absorbed (tmax, 0.58 plus/minus 0.11 h). The oral bioavailability was calculated as 0.72 plus/minus 0.07. The metabolic formation of the corresponding alcohol after intravenous and oral administration of the parent compound appeared to occur quite efficiently, and its elimination half-life (3.09 plus/minus 0.25 and 3.69 plus/minus 0.88 h after intravenous and oral administration of nicorandil, respectively) was longer than that of the parent compound. Since the dose employed in this study was much higher than the expected therapeutic doses, whether such a good bioavailability after a lower dose of the drug would be obtained in humans remains unanswered.

Administration, Oral↗
PubMed1981

[Temporal lobe damage as pitfalls at subtemporal transtentorial approach (author's transl)].

It is essential to make a proper approach to the lesion site and retract brain, thereby securing an adequate field of vision, upon performing operations on patients for lesions of deep temporal lobe and tentorium. Although subtemporal transtentorial approaches to tumors in the tentorium, pyramis and cerebellopontine angle have been described by a number of workers, further studies have to be made on temporal lobe damage as a pitfall since only a few reports have been published to date. We have therefore examined the possible factors which are responsible for temporal lobe damage and brain swelling in six cases in which subtemporal transtentorial approaches were made. We have encountered two cases of meningioma of the pyramis and tentorium growing in the middle and posterior fossa, one case each of acoustic neurinoma and trigeminal neurinoma located in the middle and posterior fossa, one case of aneurysm at a marginal branch of the superior cerebellar artery and one case of arteriovenous malformation of the deep temporal lobe. Temporal lobe damage was observed in two of these cases during operation and in post-operative CT scans. Although no particular symptoms were noted, CT scan revealed temporal lobe damage in one case. One of the main factors responsible for temporal lobe damage is cutting major veins, namely inferior cerebral vein, transverse sinus, etc. However, no damage was resulted from cutting superior petrosal sinus. Intermittent release of the brain retractor and repeated use of hyperosmotic solution including ventricular drainage are recommended for preventing temporal lobe damage.

Adolescent↗
PubMed1980

Pharmacodynamic and metabolism studies on a new coronary vasodilator, N-(2-hydroxyethyl) nicotinamide nitrate (SG-75).

Pharmacodynamics and metabolism of N-(2-hydroxyethyl) nicotinamide nitrate (SG-75) were investigated in rats in relation to its main metabolic product. When SG-75 was orally administered, SG-75 and SG-86, a denitrate compound of SG-75, appeared in the blood. Within 7 yr, approximately 60% of the administered SG-75 were recovered in the urine as SG-86. When administered intraduodenally, SG-75 was rapidly absorbed and transferred in an unaltered form into the portal vein. SG-75 possessed hypotensive and coronary vasodilating actions, while SG-86 had little effect on the cardiovascular system. The coronary vasodilating effects of SG-75 k(0.3-20 micrograms i.a.) were unaffected by the continuous infusion of SG-86 into the coronary perfusion system, even in large doses (50 micrograms/min, or 500 micrograms/min).

Animals↗
PubMed1980

Selective binding of sucralfate to ulcer lesion. II. Experiments in rats with gastric ulcer receiving 14C-sucralfate or potassium 14C-sucrose sulfate.

14C-Sucralfate, a basic aluminum salt of 14C-sucrose sulfate, or potassium 14C-sucrose sulfate was administered orally to rats with acetic acid-induced gastric ulcer. The radioactivities representing specific binding of the sucrose sulfate moiety were found significantly higher in ulcer sections of the stomach, with the mean within-animal ulcer/non-ulcer ratio attaining 6, 7, 12 and 2.5, respectively, at 1, 3, 6 and 24 h after 14C-sucralfate administration. Microautoradiography provided direct in vivo evidence for binding of the 14C-sucrose sulfate moiety to exuded proteins resulting in effect in formation of a pepsin-resistant barrier over the surface of an ulcer crater. No comparable findings were obtained in the area of normal mucosa. The administration of 14C-sucralfate was associated with much greater and longer-sustained binding to the ulcer lesion and retention in the stomach and duodenum than simple administration of the soluble potassium salt. These findings not only demonstrate therapeutically significant effects of basic aluminum compoundation but also substantiate likely differences from pepsin inhibitors such as amylopectin sulfate in terms of presence or absence of adhesiveness, local barrier effects, and long duration of actions.

Acetates↗
PubMedDate not supplied

Genomic copy-number aberrations related to lymph-node metastasis of colon cancer.

Lymph-node metastasis is an important indicator in the diagnosis of colon cancer. In order to determine the genes involved in metastasis, genomic copy-number aberrations in the primary tumours and lymph-node metastases were analysed in 12 patients using comparative genomic hybridization. This method detects genomic copy-number changes at the chromosomal level and the identification of the regions of aberration on any chromosome. Copy-number gains at 6p12 and losses at 8p12 were observed in a greater number of the primary tumours than in the metastases. These aberrations appear to be involved in lymph-node metastasis of colon cancer, and may allow measurement of the risk of lymph-node metastasis from a given colon cancer.

Adenocarcinoma↗
PubMedDate not supplied

Analysis of the relationship between sex and chromosomal aberrations in colorectal cancer by comparative genomic hybridization.

Colorectal cancer is thought to be more common in men than in women. The chromosomal locations of DNA gains and losses in surgical specimens of colorectal tumours were detected by comparative genomic hybridization and were compared by gender. Five chromosomal regions, 7p, 8p, 8q, Xp and Xq, contained multiple gains that were significantly more common in males than in females, and within these regions, the differences were significant for Xp21, Xp11.3, Xp11.4 and Xq26. Regions 1p, 3q, 11q, 12p, 12q and 15q contained multiple sites of gain that were significantly more common in females than in males. Tumours from male and female patients showed significantly more losses at 11p and 15q, and at 4q and Xq, respectively. The fact that gains in X-chromosomal regions were detected with a significantly higher frequency in tumours from male patients suggests that the difference between the genders might be explained by X-chromosomal inactivation.

Adenocarcinoma↗
PubMedDate not supplied

Antitumor activity of orally administered streptococcal preparation, OK-432 on murine solid tumors and its absorption from the gut.

OK-432 is an immunopotentiator which is normally administered by injection. In the present study, the antitumor activity of orally administered OK-432 on various solid tumors and the absorption of OK-432 from the gut were studied. Orally administered OK-432 inhibited the growth of Meth-A and BAMC-1 fibrosarcomas which had been subcutaneously transplanted in BALB/c mice. Autoradiograms of mice which had been administered 14C-labelled OK-432 orally demonstrated the absorption of OK-432 from the gut, and about 6% of orally administered OK-432 was absorbed 24 hrs after its administration. Moreover, an immunofluorescent study using an anti-OK-432 antibody revealed specific fluorescence in the mesenteric lymph node of mice which had been orally administered with OK-432. These results suggest that oral administration of OK-432 may be a beneficial immunotherapy.

Administration, Oral↗