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Biomedical subjects

H Ohta

Publications and source records attributed to H Ohta.

At least 541 records · Page 30Linked to original sources
PubMed1991

True aneurysms of the middle meningeal artery associated with cavernous hemangioma of the skull--case report.

A rare case of true aneurysms of the middle meningeal artery (MMA) associated with cavernous hemangioma in a 47-year-old male is presented. Angiography showed aneurysmal dilatation of the MMA, which was a tumor feeder. Histological examination confirmed the true aneurysmal character of the dilatation. The aneurysms were considered to result from increased hemodynamic stress and medial defects in the MMA.

Cerebral Angiography↗
PubMed1991

Cardiovascular responses produced by the systemic injection of kainic acid in conscious WKY and SH rats.

This study examined the cardiovascular effects of systemic injections of the excitatory amino acid analogue (EAA) kainic acid (KA) in conscious normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive (SH) rats. The injection of KA (100-1000 micrograms/kg, i.v.) produced dose-dependent but transient pressor and tachycardic responses followed by a prolonged period of bradycardia in both strains. Higher doses of KA also produced a secondary prolonged depressor response in WKY but not SH rats. Pharmacological studies demonstrated that the pressor and tachycardic responses are due mainly to increased sympathetic drive to the vasculature and heart. The KA-induced depressor response in the WKY is due principally to cardiovagal activation. After ganglionic blockade, KA produced a prolonged pressor response which was due to the release of vasopressin. These results indicate that the systemic administration of EAAs may produce their cardiovascular effects by activation of the autonomic nervous and endocrine systems and that the absence of the KA-induced hypotension in the SH rats may be related to an abnormality of cardiovagal function in this strain.

Animals↗
PubMed1991

Detection of PIVKA II produced by human hepatoma cells in nude mice.

A novel experimental nude mouse model, which is useful for investigation of the mechanisms of PIVKA II synthesis, was established by inoculation with PIVKA II-producing human hepatoma cells (huH-1). We have found markedly elevated levels of PIVKA II in the plasma of nude mice transplanted with huH-1 cells and increased PIVKA II content in huH-1 tumor tissues. Whereas we have not found detectable level of PIVKA II neither in the plasma nor in tumor tissues of nude mice transplanted different human hepatoma cells (HLF) which is not producing PIVKA II. Histology of the tumor tissues produced by huH-1 cells revealed a thick trabecular pattern with blood spaces.

Animals↗
PubMed1991

[Measurement of serum immunoreactive beta-glucuronidase: a possible serological marker for histological hepatic cell necrosis and to predict the histological progression of hepatitis].

beta-Glucuronidase, a lysosomal hydrolase, was purified from human liver tissue, and an enzyme-linked immunosorbent assay was developed using specific antibody against the enzyme. Using the assay procedure, the serum immunoreactive beta-glucuronidase (beta-glucuronidase) was determined in 190 patients with various liver diseases and in 53 healthy controls to examine whether or not the serum level of beta-glucuronidase would successfully reflect the degree of histological hepatic cell necrosis. beta-Glucuronidase was also determined at regular intervals in 28 patients with chronic hepatitis to investigate the clinical usefulness of serial measurement of the enzyme to predict the histological progression of hepatitis. These 28 patients could be subdivided into three groups, "continuously low type", "labile type" and "elevated type" according to the profiles of fluctuation of serum beta-glucuronidase values. Serum beta-glucuronidase was significantly increased in patients with hepatoma, liver cirrhosis and chronic active hepatitis compared with normal controls. There was significant positive correlation between the beta-glucuronidase and the degree of hepatic cell necrosis determined by histological observation, on the other hand, there was no statistical correlation between the transaminase activities and the degree of hepatic cell necrosis. It was confirmed in immunohistochemical study that the increased beta-glucuronidase in serum has been released from necrotic hepatic cells into blood stream. It was speculated that the elevation of serum transaminase activities had resulted from the alteration in the membrane permeability of hepatic cells rather than from hepatocellular necrosis. Histological progression of hepatitis was found in 8 of 10 patients (80%) of "labile" and "elevated type", while it was found only 3 of 18 patients (16.7%) of "continuously low type". These results suggested that the serial measurement of beta-glucuronidase could be used for an indicator to predict the histological progression of hepatitis.

Carcinoma, Hepatocellular↗
PubMed1991

A kampo prescription, shimotsu-to, improves scopolamine-induced spatial cognitive deficits in rats.

The effect of a Kampo (traditional Chinese medicine) prescription, Shimotsu-to, on spatial cognitive deficits produced by scopolamine was examined using an eight-arm radial maze and a T-maze. Scopolamine (SCOP; 0.075-0.3 mg/kg, ip) dose-dependently disrupted the radial maze performance. Single doses of Shimotsu-to (0.5 and 1.0 g/kg, po) as well as physostigmine (0.15 and 0.3 mg/kg, ip) improved the SCOP (0.3 mg/kg)-induced performance deficits in a dose-dependent manner. Shimotsu-to administered for 1 week in drinking water (0.5 and 1.0 g/kg/day) also exhibited dose-dependent reversal of SCOP-induced impairments in the radial maze performance. The same treatment improved SCOP (0.2 mg/kg)-induced impairments in T-maze delayed alternation performance. These data clearly demonstrated the beneficial effects of Shimotsu-to on spatial cognition.

Administration, Oral↗
PubMed1991

Melanocytic schwannoma in the spinal canal.

A case of melanocytic schwannoma, a rare form of schwannian neoplasm, in the thoracolumbar spinal canal of a 52-year-old man is presented. Histopathologically, the tumor was composed of irregularly interlacing spindle-shaped cells showing cystic degeneration, with occasional pigmented tumor cells. The tumor cells showed a low degree of nuclear pleomorphism without any mitotic figures. These histological features were considered to be consistent with a benign schwannian tumor showing pigmentation. Most of the pigments were considered to be melanin histochemically and immunohistochemically. According to the pathological features of the present tumor and those described previously in the literature, the neoplastic Schwann cells were assumed to have melanogenetic capacity, and the concept of the common neural crest origin of Schwann cells and melanocytes appeared to be demonstrated in the present tumor.

Humans↗
PubMed1991

[A case of type B chronic hepatitis showing rapid progression to liver cirrhosis with prolonged positive IgM anti-HBc].

We reported a case of type B chronic hepatitis with high titer of IgM anti-HBc continuously, which progressed to liver cirrhosis rapidly. The patient was a 37-years-old man, and was diagnosed as chronic type B hepatitis with severe activity by laparoscopy and liver biopsy. The titer of IgM anti-HBc persisted high level for more than 2 years. Then the second liver biopsy showed the progression to liver cirrhosis within only about 2 years. It is a very rare case to prolong positive IgM anti-HBc for such a long time. Anti-HBc production of PBMC was enhanced remarkably in this case. We considered that HBc antigens released into serum from hepatocytes with severe exacerbations had enhanced the anti-HBc producing activity of B lymphocytes. And the rapid progression in this case would be due to the episodes of severe exacerbations.

Adult↗
PubMed1991

Effect of atenolol or enalapril on diurnal changes of blood pressure in Japanese mild to moderate hypertensives: a double-blind, randomised, crossover trial.

This randomised, double-blind, crossover study compared enalapril 5 mg, and atenolol 50 mg, each dosed once daily for 4 weeks, and investigated casual and diurnal BP changes using 24 hour ambulatory BP monitoring. Both atenolol and enalapril satisfactorily lowered BP during the day and no excessive falls occurred at night. The tendency for BP to increase during the day and decrease at night was maintained during both active periods. Pulse rate was reduced only by atenolol throughout 24 hours. The BP increase observed 2 hours after rising in the morning was suppressed by atenolol but not by enalapril. Both drugs reduced the rates of systolic (greater than or equal to 160 mmHg) and diastolic (greater than or equal to 95 mmHg) BP increases to half of those during placebo. The frequency with which diastolic BP increased above these limits was less during the atenolol period. The difference in BP between a hospital casual reading and the mean 24 hour ambulatory reading was reduced only by atenolol. Furthermore, only atenolol suppressed the BP and pulse rate increases on exercise.

Adult↗
PubMed1991

[The second report on Japanese abroad with psychiatric problems: air transportation of Japanese with mental disorders in western Europe].

This is to report on airline travel processes experienced with two Japanese psychotics (schizophrenic) abroad who were treated by the local consulates of Japan, and escorted by Japanese psychiatrists from April to May in 1989. A comparative analysis was made of the two cases from the following six points of view: psychopathology concerning travel, psychiatric evaluation at the time of travel, access to local psychiatric medical services, trust between the patient and escorting physician, method of administering drugs, and cooperation in strategy with the airline company. Results indicate that the following three points are crucial in the air transportation of Japanese psychotics: 1) Establishment of patient-escorting physician trust relationship, 2) Adequate sedation through sufficient administration of tranquilizers, 3) Establishment of communication and close cooperation with the airline company.

Adult↗
PubMed1991

[Influences of menopause and oophorectomy on sex steroids secretion and metacarpal bone mineral content].

The effects of menopause and oophorectomy (OPX) upon blood levels of sex steroid and bone mineral content were studied in age- and body size-matched postmenopausal subjects (n = 55), OPX subjects (n = 42) and premenopausal controls (n = 35). Blood levels of 17-OH-pregnenolone, 17-OH-progesterone and androstenedione were significantly lower in the OPX group than in the other two groups. For DHEA, DHEA-sulfate and testosterone, there were no significant intergroup differences. The blood level of estrone was the lowest in the OPX group, followed by the postmenopausal group (p less than 0.05). For estradiol, there was no difference between the two groups and its blood level was lower in these groups than in the controls. For LH and FSH, there were no differences between the former two groups, but blood levels were significantly high in these groups (p less than 0.01). Microdensitometric indices such as GS min and sigma GS/D were all low in postmenopausal and OPX groups in comparison with the controls (p less than 0.01). There were no considerable differences in these indices between the former groups. In conclusion, ovarian interstitial cells are still functioning and secrete androgens in short interval of three years after menopause, as known from higher blood levels of androgens and converted estrone in the postmenopausal group than in the OPX group. However, there was no significant difference between these two groups with regard to metacarpal bone mineral content.

Age Factors↗
PubMed1991

[Influences of menopause and oophorectomy on bone metabolism and spinal bone mineral content].

The present study was performed on bone metabolism and spinal bone mineral content (BMC) in 3 groups of age- and body size-matched subjects: Thirty-three postmenopausal subjects, 37 oophorectomized (OPX) subjects and 22 premenopausal subjects. Serum levels of Alp and osteocalcin (OC) as indices of bone formation, U-Ca/cr and U-hydroxyproline (Hpr)/cr as indices of bone resorption, and Ca-regulating hormones, M-PTH, calcitonin (CT) and 1,25(OH)2D; were measured and spinal BMC was determined by QCT. Alp and OC levels were slightly higher in the postmenopausal group than in the OPX group and, in contrast, U-Ca/cr and U-Hpr/cr were slightly higher in the latter. The M-PTH level was slightly higher in the latter, and the CT level in the former. There was no difference in the 1,25(OH)2D level between two groups. For BMC, there was no difference between the two groups. The above results corresponded to the previously reported significant reductions in sex steroids. OPX seemed to affect bone metabolism more than menopause, there was no specific influence of OPX on spinal BMC as compared with QCT findings in postmenopausal subjects. Our previous study and the present study demonstrated that, at an interval of about 3 years after menopause or OPX, the endocrine system and bone metabolism tended to be more affected by OPX. However, BMC did not reflect any influence of OPX, or of menopause. There was no clear clinical difference between postmenopausal subjects and the OPX subjects with regard to the osteoporotic condition.

Alkaline Phosphatase↗
PubMed1990

Expression of placental alkaline phosphatase in gastric and colorectal cancers. An immunohistochemical study using the prepared monoclonal antibody.

The authors developed monoclonal antibodies (MoAb) against human placental alkaline phosphatase (PLAP). Four specific MoAb reacting only with PLAP and two nonspecific MoAb reacting equally with isozymes of alkaline phosphatase (hepatic, intestinal, and placental) were obtained. Immunohistochemical staining with the specific MoAb showed that the cell membrane and cytoplasm of cancer cells were stained in gastric and colorectal carcinoma. The incidence of PLAP positivity was 23% (25 of 107) of all gastric carcinomas. Among gastric carcinomas, the 42% (13 of 31) positivity of highly differentiated carcinoma (papillary adenocarcinoma and well-differentiated tubular adenocarcinoma) was a significantly higher rate than that found in poorly differentiated carcinoma (poorly differentiated adenocarcinoma and signet-ring cell carcinoma, five of 41, 12%). The incidence of PLAP positivity was 11% (four of 35) in colorectal carcinoma. In contrast, gastric adenoma, intestinal metaplasia, and noncancerous tissue adjacent to cancer did not show staining. These results indicated that expression of PLAP was apt to occur in more highly differentiated gastric carcinoma and was highly specific for carcinoma in the gastrointestinal tract, although its incidence was not high.

Alkaline Phosphatase↗
PubMed1990

Phosphorylation of high-Mr caldesmon by protein kinase C modulates the regulatory function of this protein on the interaction between actin and myosin.

High-Mr caldesmon, which is involved in smooth muscle contraction, was phosphorylated by protein kinase C. By chymotryptic digestion, actin- and calmodulin-binding assays and immunoprecipitation with the antibody to the C-terminal 35-kDa fragment, we have identified that all phosphate groups are incorporated exclusively into this fragment, which is the functional domain for binding actin and calmodulin. Phosphorylation of high-Mr caldesmon and its C-terminal 35-kDa fragment reduced their binding abilities to both F-actin and calmodulin. Further, their inhibitory effects on the actin-activated ATPase activity of gizzard myosin were also reversed in proportion to the degree of phosphorylation. These results suggest that phosphorylation of high-Mr caldesmon by protein kinase C, which is restricted within the C-terminal 35-kDa domain, results in the modulation of its activity in the smooth muscle actin--myosin interaction.

Actins↗
PubMed1990

Lymphoid cell subsets in colonic mucosa and HLA-DR antigens on colonic epithelia in colitis excluding ulcerative colitis and Crohn's disease.

Lymphoid cell subsets, including T cells as well as Ig-containing cells in the colonic mucosa and HLA-DR antigens on colonic epithelia, were examined in non-IBD colitis (colitis excluding ulcerative colitis (UC) and Crohn's disease) by the indirect immunoperoxidase staining method. Mouse anti-CD5, CD8, CD4, IgG, IgA1, IgA2, IgM, IgD, IgE, HLA-DR, and NuIa monoclonal antibodies were used as the first antibody. The results were compared to those of the normal controls and UC. T cell subsets in non-IBD colitis were almost similar to those of the controls and UC. The number of Ig-containing cells of all classes, except for IgA, tended to be increased in non-IBD colitis. In particular, both IgG- and IgE-containing cells were significantly increased compared to those in the controls. Compared to UC, IgG-containing cells were decreased in non-IBD colitis. Namely, in non-IBD colitis, as well as in UC, the change of Ig-containing cells (B cell lineage) was more pronounced than that of T cells. The frequency of the expression of HLA-DR antigens on colonic epithelia in non-IBD colitis was 70%, which was significantly higher than that in controls (0%), but significantly lower than that in UC (100%). Whether the differences in the number of IgG-containing cells, and the frequency of epithelial HLA-DR expression between non-IBD colitis and UC was due to the differences of the degree of local inflammation or due to the differences of the nature of the two diseases was not elucidated in this study.

Colitis↗