Search PubMed⌕ Search

Biomedical subjects

Y Hokama

Publications and source records attributed to Y Hokama.

At least 91 records · Page 5Linked to original sources
PubMed1982

[A rare case of HGH producing adenoma in direct contact with an IC medial type aneurysm].

A rare case of HGH producing pituitary adenoma which was in direct contact with right IC medial type aneurysm was reported. A 60-year-old woman was admitted to our clinic in February, 1981, for the acromegalic features, who was treated by 5 mg/day of CB-154 since 1976 under the diagnosis of HGH secreting adenoma. The diagnosis of bitemporal hemianopsia was made in 1977, but it was disappeared at the time of admission to our clinic. A coronal section of computed tomography demonstrated a high contrasted tumor shadow in the sella turcica without definite suprasellar extension. A right carotid angiography showed the right IC-medial type aneurysm between the right posterior communicating artery and ophthalmic artery. In March, 2-81, direct neck clipping of the aneurysm and subcapsular removal of the adenoma were performed by the right frontal approach. From the operative findings it was concluded that the aneurysm was partially embedded in the adenoma tissue. Post operative course was uneventful except for the fact that the basal HGH level could not be normalized without CB-154 therapy. Many cases of association of cerebral aneurysm with pituitary adenoma were reported in the literature. However, direct contact between the tumor and the aneurysm could not be detected. This case seems the first report of the direct association of cerebral aneurysm with pituitary adenoma. Etiology for the unique combination of adenoma and aneurysm was discussed. It has been well known that the prolonged high level of serum growth hormone in acromegaly produces arteriosclerotic and degenerative changes in the arterial wall. It was speculated that the formation of the aneurysm in our case particular was due to the combination effects of the following events. That is, the direct mechanical pressure of pituitary adenoma to the right IC arterial wall, the arteriosclerotic or degenerative change of the arterial wall due to the prolonged exposure to the high level of HGH, and finally traction effect of the adenoma to the arterial wall because of the reduction of the size of the adenoma due to CB-154 therapy, all above mentioned influences were considered to contribute to the aneurysm formation. Finally, the preoperative bilateral carotid angiography is not unnecessary to the operative planning of the pituitary adenoma, especially when the adenoma was HGH producing one.

Adenoma↗
PubMed1981

Distribution of prostaglandins B, E and F series in plasma of cancer patients.

Plasma prostaglandins (PGs) of normal individuals and cancer patients have been examined. With the exception of a breast carcinoma patient, all patients demonstrated significant elevations in PGE levels. Lung cancer patients showed a significant decrease in PGF, while stomach cancer patients showed a marked decrease in PGB. It is suggested that the changes in PGs may play a significant role in host-tumor metabolism.

Humans↗
PubMed1981

In vitro inhibition of platelet aggregation with low dalton compounds from aqueous dialysates of edible fungi.

Low dalton compounds from aqueous dialysates of several edible fungi have demonstrated inhibition of platelet aggregation in vitro. The species of fungi included Auricularia polytricha (black tree fungus), Cortinellus shiitake (shiitake mushroom), Agaricus biporus, and Auriculariaceae sp. (white tree fungus). The most active inhibitors as determined by 50% inhibition concentration (IC50) were demonstrated in the dialysates of the black tree fungus (10 mg/ml) and shiitake mushroom (80 ug/ml). Agaricus biporus and the white tree fungus dialysates gave IC50 of 3300 and 2750 mg/ml, respectively. Preliminary examinations suggest that, in part, the inhibitory factor(s) may be nucleosides or nucleotides and other as yet unidentified low dalton compounds. Further studies of the chemical nature of these inhibitory compounds are suggested since these fungi are consumed in quantities in some countries.

Agaricales↗
PubMed1981

Significant increase of plasma prostaglandins in cancer patients.

Plasma prostaglandin (PGs) levels of normal individuals, cardiac and autoimmune disease patients were similar with the following mean and S.E.M. in ng/ml values: Normal, 45.4 +/- 6.4; cardiac, 48.3 +/- 4.2; and autoimmune, 52.4 +/- 4.8. On the other hand, cancer patients showed a significant increase in plasma PGS with a mean +/- S.E.M. of 102.0 +/- ng/ml as compared to the values of normal individuals, cardiac and autoimmune patients. It is suggested that, in part, the increase in PGs may be associated with the depressed state of the cell-mediated immunity in cancer patients.

Autoimmune Diseases↗
PubMed1980

The effect of purified ciguatoxin on mitogen responses of mouse spleen lymphoid cells.

Ciguatoxin at 10 micrograms per tube showed a slight suppressive effect on mouse unstimulated spleen lymphoid cells. The same CTX concentration demonstrated a significant effect on mouse lymphoid cells in blastogenesis stimulated by mitogens. The lower levels of CTX (1 and 0.1 microgram) had essentially no effect on the spleen cells with the exception of one experiment. Since the high CTX concentration used was sufficient to kill two twenty gm mice, it is suggested that spleen cells are relatively resistant to CTX. Since the primary effects of CTX in vivo appear to be neurological in nature, to achieve the dose levels to affect the immune system would be extremely lethal for the whole animal.

Animals↗
PubMed1979

Chromatographic fractionation and characterization of the active platelet aggregation inhibitory factor from bromelain.

Isolation and characterization of the platelet aggregation inhibitory factor of bromelain have been presented in this study. Commercial bromelain consists of 3 major components as demonstrated by discontinuous sodium chloride gradient chromatography through carbixymethyl-sephadex column. Fraction I constituted approximately 19% of the total fraction. This fraction had no proteolytic activity or platelet aggregation inhibiting activity, but showed peroxidatic activity. Fraction II and III, which constituted the remainder of the fraction eluted with 135 mM and 800 mM NaCl concentrations, respectively, showed both proteolytic and inhibition of platelet aggregation, but no peroxidatic activity. Immunoelectrophoresis and polyacrylamide electrophoresis showed fraction I with beta-mobility while fraction II and III demonstrated gamma-mobility. It is suggested that the proteolytic activity is associated with the inhibition of platelet aggregation, since oxidation of fractions II and III with sodium tetrathionate abolished both activities. The mechanism of inhibition of platelet aggregation by bromelain is presently unknown but may involve its influence on the prostaglandin synthetic pathway of platelets.

Bromelains↗
PubMed1978

Effect of levamisole on metabolism of phagocytic cells.

The effect of levamisole (LMS) on glucose metabolism was studied using a protozoan phagocytic model and human leukocytes. At concentrations of greater than 10 microgram/ml, LMS inhibited glucose metabolism in the protozoan phagocytic model. Glucose metabolism in both the phagocytic model and normal peripheral blood leukocytes was, however, minimally altered when exposed to levels of LMS of less than 10 microgram/ml. In contrast, myeloblasts from a child with leukemia seemed to have increased metabolic activity and 5 microgram/ml of LMS markedly reduced the glucose metabolism. These preliminary studies suggest that LMS can alter glucose metabolism of certain cells and that some malignant cells may be directly inhibited metabolically by LMS.

Child↗
PubMed1978

Effect of arachidonic acid (ARA), prostaglandins E2 (PGE2), and F2alpha (PGF2alpha) on sensitized spleen cells in the hemolytic plaque assay.

Spleen cells from the BDF1 generation of DBA male X C57Bl/6 female matings sensitized with sheep erythrocytes (SRBC) were exposed to various concentrations of ARA, PGE2, and PGF2alpha for 90 minutes in vitro at 37 degrees C. Following exposure these sensitized spleen cells were then examined in the hemolytic plaque assay. No changes were demonstrated in the number of plaque forming cells (PFC) with 0.1 microgram/ml of ARA treatment. However, an increase in the number of PFC occurred with increasing concentrations of ARA. A significant increase (p less than 0.01) in PFC (59%) was shown with 10.0 microgram/ml of ARA. PGE2 treatment at 10.0 and 100.0 microgram/ml showed no evidence of increase, but a slight decrease (10%) was shown with 100.0 microgram/ml. On the other hand, exposure to PGF2alpha showed a significant increase (p less than 0.05) in PFC at the 10.0 microgram/ml (35%) and the 100.0 microgram/ml (29% levels, respectively. The data suggest that both ARA and PGF2alpha enhanced PFC formation.

Animals↗
PubMed1978

Effect of levamisole on aggregation of platelets stimulated with compounds associated with the prostaglandin synthetic pathway.

Levamisole, L-2,3,5,6-tetrahydro-6-phenylimidazo-(2,1-b)-thiazole-hydrocholoride at various concentrations (2.5 to 40 microgram) added to platelet rich plasma inhibited aggregation of platelets. The 50% inhibition concentrations (IC50) of levamisole in platelet aggregation induced by hydrogen peroixde (9.4 x 10(-1) mM), epinephrine (1.0 x 10(-1) micrometer), endoperoxide-analog (2.9 x 10(-1) micrometer) and arachidonic acid (3.3 micrometer) were 11.0, 8.0, 11.5 and 16.0 microgram/test, respectively. It is suggested that levamisole like imidazole inhibit platelet aggregation and this factor should be considered in the administration of levamisole, especially in cardiovascular diseases.

Arachidonic Acids↗