Search PubMed⌕ Search

Biomedical subjects

K Oka

Publications and source records attributed to K Oka.

At least 307 records · Page 17Linked to original sources
PubMed1993

The acupuncture point and its connecting central pathway for producing acupuncture analgesia.

Characteristics of the acupuncture point in producing acupuncture analgesia (AA) were examined by the inhibition of noxious responses in the brain stem reticular formation, potentials, and neuronal activity in the dorsal periaqueductal central gray (D-PAG), and analgesia caused by low frequency stimulation of the acupuncture point. As a result, stimulation of the muscle beneath the acupuncture point was found to be effective in producing AA. AA measured by tail flick, vocalization, and writhing tests was abolished by hypophysectomy, and by antiserum of beta-endorphin administered into the 3rd ventricle. The pathway from the D-PAG to the anterior hypothalamus (AA-AH) in the AA afferent pathway from the acupuncture point to the pituitary gland was determined. The lateral hypothalamus, lateral septum, cingulate bundle, dorsal-hippocampus, and habenulo-interpeduncular tract were found, in addition to regions previously found, to belong to the AA afferent pathway. A network of divergence and convergence in their rostral and caudal relations was observed. The AA afferent pathway diverges from the D-PAG, converges to the HP, and then projects to the AA-AH.

Acupuncture Analgesia↗
PubMed1993

Comparison of adrenal functions in kidney transplant recipients with different long-term immunosuppressive treatments--prednisolone and azathioprine versus prednisolone and cyclosporine.

Adverse effects of cyclosporine on the adrenal cortex have been documented in animal experiments, but nothing has been reported in human subjects. Endogenous cortisol in peripheral blood was monitored for three years after transplantation, with 30 kidney recipients on two different immunosuppressive treatments. In the azathioprine group, 16 patients were treated with coadministration of prednisolone at an initial dose of 120 mg/day. In the cyclosporine group, 14 patients were also treated with prednisolone, using an initial dose of 60 mg per day. Short ACTH stimulation tests were performed to reconfirm the results obtained by basal cortisol monitoring. During the first year following transplant, cortisol concentrations in the cyclosporine group were higher, though not significantly so, than those in the azathioprine group, in accordance with cumulative amounts of prednisolone administered. At three years, however, the mean cortisol concentrations in the azathioprine group were 2-3 times higher than those in the cyclosporine group (P < 0.05). All patients in the azathioprine group responded well to ACTH, whereas 4 patients out of 14 in the cyclosporine group showed continuous severe suppression without considerable response to ACTH (P < 0.01). In conclusion, we would like to suggest that adrenocortical toxicity of long-term cyclosporine use may appear one year after transplant, resulting in chronic suppression of the adrenal cortex, and, accordingly, difficulty in further reduction of prednisolone use.

Adrenal Glands↗
PubMed1993

Liquid chromatographic determination of magnolol in urine collected from volunteers after a single dose of saiboku-to, an oriental herbal medicine for bronchial asthma.

Saiboku-To is an anti-asthmatic herbal remedy which consists of ten herbal extracts. To investigate the clinical relationship between the effects and chemical components of Saiboku-To, a simple and sensitive high-performance liquid chromatographic method (HPLC) for determination of magnolol, one of the major urinary products, was developed. Organic solvent extraction of urinary magnolol was conducted by diatomaceous earth column rapid-flow fractionation using ethanol/dichloromethane (8/92, v/v). Recovery rates of magnolol were more than 99% with coefficient of variations less than 6% in the concentration range 9.7-970 ng mL-1. Subsequent HPLC determination of magnolol was achieved using a conventional silica-gel column, a mobile phase mixture of acetic acid/diethyl ether/n-hexane (0.2/17.0/82.8, v/v), and a UV-absorption detector set at 290 nm. Calibration was on the basis of peak height ratio between magnolol and flavone as an internal standard. The method was used to demonstrate excretion profiles of magnolol in healthy and asthmatic subjects following single administration of Saiboku-To.

Adult↗
PubMed1993

Impact of free magnolol excretions in asthmatic patients who responded well to saiboku-to, a Chinese herbal medicine.

Saiboku-To, a mixture of ten different herbal extracts, has been used in Japan and Czechoslovakia for corticosteroid-dependent severe asthma to reduce the maintenance doses of corticosteroid. Magnolol has been considered to be an active component of Saiboku-To as an inhibitor of 11 beta-hydroxysteroid dehydrogenase and T-lymphocyte proliferation resulting in corticosteroid-sparing. To investigate the relationship between magnolol and the clinical effects of Saiboku-To, urinary magnolol excretion was compared in responders and non-responders under long-term Saiboku-To treatment. The clinical outcome of the Saiboku-To treatment was evaluated in nine asthmatic patients at 52 weeks after the onset of the treatment, using individual fluctuation of asthmatic points obtained from the patients' diary cards. Three patients whose clinical conditions were improved by the treatment were termed responders and six others were termed non-responders. The difference in the amounts of the total magnolol excreted were not significant; however, free (or non-conjugated) amounts of magnolol excreted in the responders were 7 times those in the non-responders (P < 0.05). These results suggest that the magnolol might be responsible for the therapeutic effect of Saiboku-To, indicating practical bioavailability in the responders.

Adult↗
PubMed1993

Immunohistochemical characteristics of monocytoid B cell lymphoma, mantle zone lymphoma, small lymphocytic lymphoma (or B chronic lymphocytic leukemia), and hairy cell leukemia.

Biopsy specimens obtained from 2 patients with monocytoid B cell lymphoma, 7 with mantle zone lymphoma, 7 with small lymphocytic lymphoma or B chronic lymphocytic leukemia, and 6 with hairy cell leukemia were investigated using an immunohistochemical method to detect their immunophenotypic characteristics. Periodate-lysine-paraformaldehyde-fixed frozen biopsies from the lymph node, peripheral blood, bone marrow, spleen, tonsil, lung, and stomach were studied. Monocytoid B cell lymphoma exhibited the immunophenotype of surface(s) IgD-/DRC-1-/Leu-1(CD5)-/Leu-M5(CD11c)-, +/- on the neoplastic cells or neoplastic lesions, mantle zone lymphoma exhibited that of sIgD+/DRC-1++/Leu-1-,+/Leu-M5-, small lymphocytic lymphoma or B chronic lymphocytic leukemia that of Leu-1+/sIgD-,+sIgD-,+/DRC-1- > +Leu-M5-, and hairy cell leukemia that of Leu-M5++/sIgD- >> +/Leu-1- >> +/DRC-1-. We therefore suggest that these four types of lymphomas can be differentiated by a combination of anti-sIgD, DRC-1, Leu-1, and Leu-M5 monoclonal antibodies based on their immunophenotypic characteristics.

Bone Marrow↗
PubMed1993

Angiotensin-II stimulates an increase in cAMP and expression of 17 alpha-hydroxylase cytochrome P450 in fetal bovine adrenocortical cells.

While known to be a potent activator of phosphoinositidase C, angiotensin II (A-II) also causes a small but significant increase in cAMP production through the type 1 A-II (AT1) receptor in bovine adrenocortical cells (Mol Cell Endocrinol 81:33-41, 1991). We have carried out studies on primary cultures of fetal bovine adrenocortical cells to examine the effects of A-II on the expression of cytochrome P450 17 alpha-hydroxylase (P450c17), which is known to be regulated in a cAMP-dependent fashion. Prolonged treatment (48 h) of cells with A-II (10(-7) M) did not give rise to a detectable increase in P450c17 as measured by immunoblotting, although both A-II and the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA) attenuated the large increase in P450c17 induced by ACTH (10(-8) M). A-II alone (10(-7) M) however, caused a time-dependent increase in cAMP secretion, reaching 8-fold within 3 h. Prolonged treatment of cells with A-II also resulted in a 3-fold increase in P450c17 mRNA within 12 h (10(-7) M), and a dose-dependent increase in 17 alpha-hydroxylase activity within 48 h (16.4-fold max at 10(-7) M). The stimulatory actions of A-II alone (10(-7) M) on cAMP levels, P450c17 mRNA, and 17 alpha-hydroxylase activity were much smaller than in response to ACTH (10(-8) M), but were largely reproduced by TPA (10(-7) M), suggesting a role for protein kinase C in mediating these responses to A-II. These findings indirectly support the hypothesis that A-II alone can stimulate an increase in cAMP in adrenocortical cells. Such a stimulation of cAMP may then result in increased expression of steroidogenic enzymes, as we have shown is the case for P450c17 expression. However, A-II in the presence of ACTH appears to attenuate the ACTH-stimulated expression of P450c17.

Adrenal Cortex↗
PubMed1993

Flexible endoneurosurgical therapy for aqueductal stenosis.

We successfully managed 11 patients with aqueductal stenosis of adult or adolescent onset, with no mortality or significant morbidity, by using a flexible ventriculoscope to perform either a third ventriculostomy or an aqueductal plasty. A flexible fiberoptic ventriculoscope and its accessories were newly developed, and surgical techniques were improved. For all patients, cinemagnetic resonance imaging was a critical part of the preoperative and postoperative evaluation of cerebrospinal fluid flow in the third ventricle and in the aqueduct of Sylvius. All of the 11 patients showed patency to cerebrospinal fluid flow at the aqueduct of Sylvius and the floor of the third ventricle. Only one patient subsequently required a lumboperitoneal shunt. Flexible endoneurosurgical management is simple and safe and allows in situ observation and the ability to perform biopsies. Therefore, flexible endoneurosurgical third ventriculostomy and aqueductal plasty are now considered our treatment of choice for aqueductal stenosis in adults and adolescents.

Adolescent↗
PubMed1993

Satisfactory separation and MS-MS spectrometry of six surfactins isolated from Bacillus subtilis natto.

We optimized HPLC conditions for the first time to achieve satisfactory separation of six surfactins, two of which were novel, isolated from Bacillus subtilis natto. Peptide sequences were analyzed by sophisticated MS-MS analysis, performed with a pair of two surfactins with different fatty acid substitutions. Fragment peaks were divided into two series; one was a series of the ions which carried fatty acid, and thus were characterized by the fatty acid mass difference, and the other was a series of the ions which consisted of pure peptide and thus showed a superimposable pattern between a pair of surfactins.

Amino Acid Sequence↗
PubMed1993

Intracranial cavernous angioma manifesting as subarachnoid hemorrhage--case report.

A 56-year-old male presented with a posterior fossa cavernous angioma manifesting as persistent headache with mild neck stiffness. Lumbar puncture revealed subarachnoid hemorrhage (SAH). Repeated four-vessel angiography failed to identify the source of the SAH. Magnetic resonance (MR) imaging demonstrated multiple small lesions in the posterior fossa and cerebral hemispheres, and the SAH. A mass arising from the biventral lobule of the right cerebellar hemisphere extended exophytically into the cisterna magna with intratumoral hemorrhage. These findings were compatible with the presumptive diagnosis of SAH from the mass at the right biventral lobule. The lesion was totally removed through a suboccipital craniectomy without sequelae. The histological diagnosis was cavernous angioma. Intracranial cavernous angioma presenting only as SAH has never been reported before. The use of MR imaging in establishing the diagnosis of vascular malformations is emphasized, particularly when neither computed tomography nor angiography can adequately visualize the origin of SAH.

Cerebellar Neoplasms↗
PubMed1993

Laparoscopic treatment of ectopic pregnancies--reports of two cases.

Two cases with ectopic pregnancy were successfully treated by laparoscopic injection of methotrexate (MTX). Case 1: A 29 year-old housewife was laparoscopically treated with a 15 mg MTX injection to the left Fallopian tube. After the laparoscopy, the human chorionic gonadotropin (HCG) was reduced to the normal range. Case 2: A 34 year-old housewife was also laparoscopically treated with a 35 mg MTX injection to the right Fallopian tube. After the laparoscopy, the HCG was quickly reduced to the normal range. The endoscopic approach can be used as the surgical treatment of choice for ectopic pregnancies.

Adult↗
PubMed1993

Discordant reaction of Leu4 and rabbit anti-human CD3 epsilon in sinonasal 'T'-cell lymphoma.

Twelve cases of sinonasal 'T'-cell lymphoma were studied immunohistologically with a panel of antibodies that included two antibodies to CD3, Leu4 and rabbit anti-human CD3 epsilon. Leu4 was positive in five cases, whereas rabbit anti-human CD3 epsilon was positive in 11. This discordant reaction of the antibodies, suggestive of cytoplasmic CD3 epsilon +, CD3 delta-, and CD3 gamma-, has recently been demonstrated in activated adult natural killer (NK) cells also. Leu4-negative cases had the phenotype CD2+, CD5-, CD7+/-, T-cell receptor (TCR)-, and NK cell markers+, and had non-rearranged TCR genes. These findings suggest that a large group of sinonasal 'T'-cell lymphomas is derived from NK cells.

Adolescent↗
PubMed1993

[A study on cervical cerclage for a dilated cervix or bulging membranes without rupture of membranes].

During the period January 1, 1989 through December 31, 1991, one hundred thirty-six pregnant women with an effaced and widely dilated cervix or with bulging membranes were treated by emergent cervical cerclage. Suturing was carried out in 16 women before 20 weeks gestation, in 86 women between 20 and 28 weeks and in 34 women after 28 weeks. 16 patients in group A were those whose pregnancy was terminated with 3 days after operation and their tocolysis index was significantly higher than that of 69 patients in group D, whose pregnancy was prolonged move than two weeks. Clinical chorioamnionitis (WBC > 15,000/mm3 and CRP > 2mg/dl) was occurring in 43.7% of patients in group A, compared with 8.7% in group D at the time of operation. Vaginal delivery was accomplished in 38 patients at between 24 and 36 weeks gestation in our hospital, while 41 cesarean sections were performed. On the basis of these results, we conclude that the emergency cerclage operation may improve the outcome of pregnancy but we have to pay special attention to premature rupture of membranes and chorioamnionitis.

Abortion, Threatened↗
PubMed1993

Triathlon competition induced a transient immunosuppressive change in the peripheral blood of athletes.

This study was designed to determine whether or not physical and psychological stress of triathlon competition causes an immunosuppressive change in the peripheral blood of athletes, if it does occur, how long does it take to recover. Fifteen healthy men, aged 19 to 40, volunteered for this study. Peripheral blood was drawn four times at approximately the same time on the following days; one day before the race, immediately after, one day and eight days after, and served for determining circulating leucocyte and lymphocyte subset counts, in vitro lymphocyte proliferative response and natural killer activity. The results showed that triathlon competition caused considerable changes in the cell counts of peripheral blood leucocyte and lymphocyte subsets, and a transient reduction in vitro lymphocyte proliferative response and natural killer activity, all of which returned to pre-race levels in one to eight days after the race.

Adult↗
PubMed1993

Regulation of hepatic triglyceride lipase by thyroid hormone in HepG2 cells.

Hypothyroidism has been reported to be associated with reduced hepatic triglyceride lipase (HTGL) activity. In order to understand the molecular mechanism by which thyroid hormone regulates HTGL activity, effects of triiodothyronine (T3) on HTGL activity, mRNA level, transcription run-on activity, and protein synthetic rate were studied in HepG2 cells. HepG2 cells treated with 1 nM T3 showed an increase in HTGL activity that was first detected at 24 h; HTGL activity continued to increase at 36 h and stayed at the elevated level at 48 and 60 h. At maximal stimulation (48 h), T3-treated cells had the following HTGL activities: 155% in spontaneously released (SR) and 224% in heparin-releasable (HR) HTGL activities (mean levels compared to control). Stimulation of HTGL activity by T3 was dose-dependent and saturable. There was, however, no change in HTGL mRNA level throughout the course of T3 treatment. The effects of T3 were reduced when transcription was blocked by actinomycin D (mean level compared to actinomycin D treatment in the absence of T3: 109% in SR and 127% in HR activities) or translation was blocked by cycloheximide (127% in SR and 122% in HR activities), but HTGL activities were still significantly higher than control. Nuclear run-on assays indicate that T3 did not change the rate of transcription of the HTGL gene. We further determined the rate of HTGL synthesis by measuring the amount of [35S]methionine incorporated into newly synthesized HTGL immunoprecipitated by a monospecific anti-human HTGL antibody. We found that the T3-stimulated increase in HTGL activity was not accompanied by any change in the rate of HTGL biosynthesis. Our experimental data indicate that the T3 stimulation of HTGL activity in HepG2 cells is mediated at posttranscriptional and posttranslational levels. The partial but significant inhibition of the T3 stimulation of HTGL activity by actinomycin D and cycloheximide suggests that the effects of T3 may be mediated by other cellular processes that are more directly regulated by the hormone. This study represents the initial report on the mechanism of HTGL activation by physiological concentrations of thyroid hormone.

Base Sequence↗
PubMed1993

Gamma/delta T-cell lymphoma with hepatosplenomegaly: report of a case.

We describe the case of a patient with peripheral gamma/delta T-cell lymphoma (T-ML) with hepatosplenomegaly, generalized lymphadenopathy, and bone marrow involvement. A 44-year-old man had lymphoma, which became clinically apparent 2 months after the onset of myositis and insulin-dependent diabetes mellitus. A cervical lymph node biopsy specimen showed diffuse infiltration by large neoplastic cells with vascular proliferation. The neoplastic cells expressed the T-cell receptor (TCR)delta chain detected by TCR delta 1 and delta-TCS1, CD3, CD30, CD45RO, and epithelial membrane antigen, but not the TCR beta chain detected by beta F1, CD1a, CD2, CD4, CD5, CD7, CD8, CD25, HLA-DR, and terminal deoxynucleotidyl transferase. The cells had a clonal rearrangement of TCR gamma chain gene and a germ-line configuration of immunoglobulin heavy chain gene and TCR beta chain gene. Despite chemotherapy, the patient died of refractory lymphoma 4 months after diagnosis. Examination at autopsy revealed that the main hepatic and splenic neoplastic infiltration sites were the portal area and white pulp, respectively. Our patient differed from those with gamma/delta T-ML with hepatosplenic involvement reported previously with respect to the hepatic and splenic neoplastic infiltration patterns and the presence of lymphadenopathy.

Adult↗
PubMed1993

[A case of double mitral valve with severe mitral regurgitation detected by transesophageal echocardiography].

A 66-year-old woman with double mitral valve (bridge type) and severe mitral regurgitation by spontaneous ruptured chordas is reported. The case with this combination has not been reported in the literature. She had not any other congenital heart diseases. The mitral valve was clearly shown by two-dimensional Doppler transesophageal echocardiography. Mitral valve replacement with Medtronic-Hall valve was carried out successfully.

Aged↗