Search PubMed⌕ Search

Biomedical subjects

K Okada

Publications and source records attributed to K Okada.

At least 1,045 records · Page 58Linked to original sources
PubMed1991

Incidence of silent lacunar lesion in normal adults and its relation to cerebral blood flow and risk factors.

BACKGROUND AND PURPOSE: There are few reports comparing incidence of silent lacunar lesions detected by magnetic resonance imaging and cerebral blood flow in neurologically normal adults. METHODS: We studied the incidence of such lesions and its relation to cerebral blood flow and risk factors in 246 neurologically normal adults (145 men, mean age 62 years; 101 women, mean age 60 years) who received health screening examinations of the brain. RESULTS: Thirty-two subjects (13%) had possible silent lacunar lesions (66% of these were recognized by both T1- and T2-weighted image). The regional cerebral blood flow measured by the xenon-133 inhalation method was significantly lower in subjects with silent lacunes than in those without (p less than 0.02). Cerebral blood flow was mildly but significantly decreased in those with silent lacunes (p less than 0.05). Periventricular hyperintensity was closely related to silent lacune (p less than 0.01). However, there was no significant difference in cerebral blood flow between subjects with and without apparent periventricular hyperintensity. CONCLUSIONS: Silent lacunar lesion was closely related to decrease of cerebral circulation and may be an important risk factor for symptomatic cerebrovascular disease.

Adult↗
PubMed1991

[An all-night electroencephalographic study on grand mal epilepsy in childhood. A longitudinal study on the incidence of epileptic discharges with treatment and the comparison between all-night electroencephalography and standard sleep activated electroencephalography].

In order to quantify changes in epileptic discharges during the course of phenobarbital (PB) therapy, 8 children with generalized tonic-clonic seizure (GTC) corresponding to sleep epilepsy as defined by Janz were given PB, and their all-night EEGs were obtained by means of a polygraph with simultaneous measurement of the blood concentration of PB. EEGs were recorded before the treatment commenced and 3 days, 14 days, one month, 6 months, one year, 1.5 and 2 years after the beginning of the treatment. For each child, the number of epileptic discharges during sleep was determined. The incidence of epileptic discharges (total number of epileptic discharges during sleep divided by total sleep time) was calculated, and changes during the course of the treatment were examined. In addition, the findings (pattern of epileptic discharges) obtained through standard short-time EEG recordings were compared with those obtained through all-night EEG recordings in terms of the incidence of epileptic discharges during the first S1-S2 after the subject had fallen asleep and the incidence of epileptic discharges during all stage of S1 and S2 while asleep. There were two different patterns of changes in the incidence of epileptic discharges. In 5 of the 8 children, the incidence was decreased at the initial stages of treatment, but it began to increase about one month later, returning to the baseline level (re-increased type). In the remaining 3 children, the incidence decreased favorably after the beginning of treatment, reaching nil within one year (simple decrease type). The incidence of epileptic discharges was found to be decreased in all 8 children after 3 days of treatment, when the blood PB concentration had not reached the effective level. Standard EEG and all-night EEG revealed similar patterns of epileptic discharges.

Adolescent↗
PubMed1991

Histopathology and distribution of cells harboring bovine leukemia virus (BLV) proviral sequences in ovine lymphosarcoma induced by BLV inoculation.

Six sheep with lymphosarcoma induced by hypodermic inoculation of bovine leukemia virus (BLV) materials were examined to elucidate the relation between pathologic lesions and integration of BLV provirus in cellular DNAs. Antibodies to BLV gp-antigens had been detected since the 3rd week after the inoculation, and BLV was positive when checked 3 months later. Lymphosarcomas followed the leukemic phase in 4 sheep. The other 2 sheep showed initial lesions of lymphosarcoma and were aleukemic clinically. Five animals were killed by enthanasia and autopsied at 2.5 to 3.5 years postinoculation (pi) because of their diseased condition. One animal died 10 years pi following the 4th leukemic episode. Sarcomatous lesions were confirmed grossly and histologically, and the proliferating neoplastic cells were classified into lymphocytic, prolymphocytic, lymphoblastic and histiocytic types. Integration of BLV provirus in cellular DNAs of the peripheral blood lymphocytes (PBL) and neoplastic cells of sarcomatous lesions was examined by Southern blotting technique. BLV provirus was demonstrated in the PBL of all infected animals and in most of the sarcomatous lesions of the spleen, kidney and lymph nodes except 4 lymph nodes showing slight neoplastic infiltration. The results indicated that ovine lymphosarcoma could be caused by BLV and the cells carrying proviral information seemed to be disseminated and proliferate in the lesions.

Animals↗
PubMed1991

Role of antidiuretic hormone in hyponatremia in patients with isolated adrenocorticotropic hormone deficiency.

We found symptomatic hyponatremia in four elderly patients in which serum sodium (Na) levels ranged from 101 to 122 mEq/l. All 4 patients had low levels of plasma adrenocorticotropic hormone (ACTH), serum cortisol, and urinary excretion of 17-OHCS, and poor responses of ACTH to exogenous insulin and antidiuretic hormone (ADH). Other pituitary hormones were all normal. They were therefore diagnosed as having isolated ACTH deficiency. Plasma ADH was relatively high despite hypoosmolality which was associated with the hyponatremia. Water loading test revealed impaired water excretion and poor suppression of plasma ADH. Replacement with 20-30 mg hydrocortisone completely restored the serum Na level and restored the plasma ADH level to the normal range in all 4 patients. Other factors such as decreased glomerular filtration, enhanced urinary Na loss and decreased Na intake were also included. These results indicate that there is marked hyponatremia and that in the presence of hypoosmolality the sustained secretion of ADH is the key factor in causing the impaired water excretion and hyponatremia in isolated ACTH deficiency.

Adrenocorticotropic Hormone↗
PubMed1991

Intradermal hepatitis B virus vaccination for low- or non-responded health-care workers.

Immune responses to hepatitis B virus (HBV) vaccine in six low- or non-responded health-care workers were tested with an intradermal low dose (5 micrograms) of the recombinant vaccine. The injection was repeated three or four times at fortnightly intervals. These successive doses of the vaccine induced a high concentration of antibodies with delayed-type hypersensitivity (DTH) skin reactions in all six subjects. A few minor temporary side effects, such as irritation and itching at the injection site, were reported by some of the vaccinees. The results suggest low-dose of intradermal HBV vaccinations for low- or non-responders are safe and readily effective.

Administration, Cutaneous↗
PubMed1991

[The relationship between cerebral white matter changes, mental function and blood pressure in normal elderly].

The authors examined the relationship between cerebral white matter changes and mental function, blood pressure in 39 neurologically normal aged (21 males, 18 females, mean age 75.0 years) who had no latent lesions on MRI images. The severity of cerebral white matter changes was estimated by T1 value images on MRI and was measured in the bilateral frontal lobe on an axial slice at the level of the basal ganglia and in the bilateral anterior, middle, and posterior portions on axial slices at the level of the body of the lateral ventricle. Mental function was measured by the Hasegawa's dementia rating scale (HDS) and Kohs' block design test (Kohs' test). The severity of cerebral frontal white matter changes increased significantly with age (p less than 0.05). However there was no significant correlation between the severity of cerebral white matter changes and HDS, Kohs' test. The severity of frontal white matter changes correlated with the mean arterial blood pressure (p less than 0.02). These results suggest that the severity of cerebral white matter changes is not related with mental function in the normal elderly, and that the severity of frontal white matter lesions is related with mean arterial blood pressure.

Adult↗
PubMed1991

Effects of long-term corporate fitness program on employees' health.

The higher average age of employees, due to the advancement of the compulsory retirement age, and their sedentary lifestyle in automated environments, have become important issues in the workplace, as witnessed in increased incidence of adult disease and decreased physical fitness levels. The purpose of the present study was to evaluate the effects of a long-term corporate fitness program in helping employees to stay well. The fitness program consisted of medical checkups, physical fitness tests, and a physical training program, given on an individual basis. The medical checkups and physical fitness tests were evaluated in 1499 male employees, with the following results. 1) The incidence of obesity showed no significant change. 2) There were no significant changes in total cholesterol levels nor in the incidence of hypertriglyceridemia and hypercholesterolemia. 3) Physical fitness was markedly improved. 4) There was a decrease in the percentage of smokers. These results suggest that a long-term corporate fitness program is effective for improving the health and fitness levels of employees and for preventing the progression of adult disease.

Adult↗
PubMed1991

[Treatment of renal cell carcinoma with human lymphoblastoid interferon alpha and UFT in combination. A prospective multicenter trial].

A cooperative study of combination of UFT (a compound of FT and Uracil) and human lymphoblastoid interferon (IFN-alpha) was conducted in the cases of metastatic renal cell cancer. IFN-alpha was administered over 3 times a week at a dose of 3 X 10(6) units in combination with UFT at a daily dose of 600 mg FT equivalent. Twenty-eight patients from 16 collaborating institutions were the subjects of the present study. The antitumor effects of the drugs were clinically evaluable in 25 cases according to the response criteria of Japan Society for Cancer Therapy. Complete responses and partial responses were observed in 3 and 2 cases, respectively, showing a response rate of 20 per cent. One complete responder had bone and liver metastases and has been alive for more than 2 years without any evidence of relapse. All of the other responders had lung metastasis. The survival durations of the other two complete responders were 716 days and 255 days. The two partial responders had been alive for more than 819 days and 471 days. The adverse effects of this combination therapy were minimal. Combination of a biological response modifier and a cancer chemotherapeutic agent seems to be a way to increase the treatment efficacy of renal cell cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

[Significance of transrectal hyperthermia in the treatment of benign prostatic hyperplasia].

Though the local hyperthermia for the management of benign prostatic hyperplasia has drawn much attention as one non-surgical treatment, no definite conclusion could yet be obtained in terms of the efficacy. In this study local hyperthermia was induced in evaluable 33 cases with benign prostatic hyperplasia using Primus, and the effectiveness of this modality of treatment was investigated by analysing the subjective and objective response following hyperthermia. The prostate was heated trans-rectally up to 43 degrees C with 915 MHz microwave for one hour. Hyperthermia was carried out twice a week for ten times for the sake of thermotolerance. Urinary obstructive symptoms were divided into diurnal and nocturnal frequency, urinary urgency, the degree of urinary stream, hesitancy and dribbling. Each symptom was described before and after the treatment according to the scoring system. Moreover, objective changes of urinary flow and prostatic size were estimated by the residual urine volume, uro-flowmetry, rectal palpation of the prostate and echography. Hyperthermic treatment improved urinary flow markedly, but no appreciable alteration could be observed as to the size of the prostate. The overall efficacy, including subjective and objective response, could be summarized as 37% of effectiveness, and 33% of slight effectiveness, that is, 70% of effective ratio. As to the side effect, anal pain was noted in few cases of the present series. Therefore, transrectal hyperthermia may be a suitable modality for non-surgical treatment of benign prostatic hyperplasia.

Evaluation Studies as Topic↗
PubMed1991

[Histopathological findings of prostate carcinoma--nuclear anaplasia (NAN) and structural atypism (SAT)].

Most of the previous publications have focused mainly on structural atypism (SAT) or differentiation in the studies on histopathological findings of prostate carcinoma. We studied nuclear anaplasia (NAN) as well as SAT in prostate carcinoma, comparing with differentiation grade or Gleason's pattern, to find NAN's clinical implication. We also compared histopathological findings of prostate carcinoma in our cases with those in U.S.A. Analysis of NAN grade and SAT grade distribution in stages revealed a correlation between the grades and the stages, in which SAT1 or NAN1 decreased while SAT3 or NAN3 increased in their frequencies as stage progressed. A similar correlation was found between mean value of SAT + NAN grade and stage. While NAN grade and SAT grade agreed with each other in 70% of the patients with prostate carcinoma, that was not the case in the remaining patients. This suggested a complementary relationship between NAN grade and SAT grade in some patients. A similar relationship was found between NAN grade and Gleason's pattern. These results suggest that, in a non-negligible number of patients, the NAN grade does not agree with the SAT grade or Gleason's pattern which is defined by atypism in the glandular structure. Disease-specific survival in each SAT grade could be further defined by the NAN grade. For example, in both SAT2 and SAT3, NAN3 tended to have a poorer prognosis than NAN2. Thus, NAN grading system would furnish more accurate information to predict the patients' clinical course.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaplasia↗
PubMed1991

[Thymidylate synthase inhibition and concentration of 5-fluorouracil after administration of UFT in human uroepithelial carcinomas].

Inhibition of thymidylate synthase (TS) and the concentration of tegafur, 5-FU and uracil in the tumor and the non-tumor tissues were compared in 18 uroepithelial cancer patients who had been administered UFT (600 mg/day) for seven days before operation. 5-FU and uracil levels in the tumor tissue were increased to 5.1 and 3.6 fold, respectively, compared those in the normal tissue, although there was no difference in tegafur levels between normal and tumor tissue. The mean inhibition rate of TS activity in the tumor tissue was significantly higher (36%) than that in the normal tissue (21%). However, no correlation between 5-FU level and inhibition rate of TS activity was found in either tissue. Not only the higher tumor concentration of 5-FU but also the higher inhibition of TS activity in the tumor tissue suggests that UFT is likely a useful drug for the treatment of uroepithelial carcinomas.

Adenocarcinoma, Mucinous↗
PubMed1991

Negative supercoiling of DNA by eukaryotic DNA topoisomerase II and dextran sulfate.

In the presence of a molar excess of eukaryotic DNA topoisomerase II and an appropriate concentration of dextran sulfate, relaxed closed circular DNA is converted to a negatively supercoiled form. The reaction is dependent on ATP. Neither adenosine 5'-[beta,gamma-imido]-triphosphate nor adenosine 5'-[gamma-thio]triphosphate can substitute for ATP. The negative supercoils formed are relaxed by subsequent addition of DNA topoisomerase I to the supercoiling reaction mixture. Covalent closure of a nicked circular DNA in the presence of DNA topoisomerase II and dextran sulfate but in the absence of ATP causes a small decrease in the linking number. These results suggest that when an appropriate concentration of dextran sulfate is present, the binding of a molar excess of eukaryotic DNA topoisomerase II constrains a small number of negative supercoils in DNA, which in turn generate unconstrained negative supercoils at the expense of ATP.

Adenosine Triphosphate↗
PubMed1991

[Mechanisms of acquired resistance to DNA topoisomerase I inhibitors].

The mechanisms of acquired resistance to mammalian DNA topoisomerase I inhibitor, camptothecin or its derivative (CPT-11) were described. Tumor cell lines containing altered or reduced topoisomerase I were reviewed. It might be necessary to further study on reduced inhibitor uptake and other unknown mechanism.

Animals↗
PubMed1991

[Efficacy of anticancer agent-lipiodol emulsion for hepatic arterial infusion and regional hyperthermia in patients with nonresectable hepatoma].

The efficacy of combination therapy of anticancer agent-Lipiodol Emulsion for hepatic arterial infusion and regional hyperthermia was studied in 102 patients with nonresectable hepatoma. 5-FU, MFA, CDDP and MFA-CDDP were used as anticancer agents in 13, 44, 26 and 19 patients, respectively. One year survival rates of the each group were 9% (1/13, 5-FU-treated), 29% (12/44, MFA-treated), 43% (11/26, CDDP-treated) and 55% (10/19, MFA-CDDP-treated). Tumor regression was found in one out of 11 (9.1%), 11 out 41 (26.8%), 6 out of 23 (26.1) and 9 out of 19 patients (47.4%), respectively. The regional hyperthermia was particularly efficacious for patients with advanced hepatoma (E3 and E4) and clinical stage II, III; 5 out of 32 patients (16%) receiving arterial infusion and hyperthermia survived more than 1 year while all 15 patients without hyperthermia died within 11 months (p less than 0.01). Our data indicate that repeated arterial infusion of MFA and CDDP Lipiodol Emulsion was most effective for nonresectable liver cell cancer, and the regional hyperthermia prolonged the survival of patients who had advanced hepatoma with poor liver function.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

[Alterations in number of rabbit myocardial beta-adrenergic receptors in endotoxic shock: down regulation in hyperdynamic sepsis model and effects of cytokines administration].

We investigated alterations in myocardial beta- and beta 1-adrenergic receptor (BAR and B1AR) number during hyperdynamic state induced by endotoxin or cytokines. [METHODS] Twenty-nine Japanese White rabbits were divided into 2 groups. Hearts were removed 18 h after intraperitoneal administration of sterile saline (SAL) or E. coli endotoxin (LPS; 50 micrograms/kg) (Group E, n = 12), or 3 h after intravenous injection of SAL or cytokines (interleukin 1-beta; 5 micrograms/kg followed by 25 ng/kg/min for 2 h, or tumor necrosis factor; 5 micrograms/kg) (Group C, n = 17). BAR and B1AR numbers were determined in myocardial membranes from rabbit left ventricles with techniques of radioactive ligand binding study. We used [3H] dihydroalprenolol (3H-DHA) as radioactive ligand, and specific 3H-DHA binding to BARs was defined as the difference between the presence and the absence of 10 microM propranolol. B1AR number was assessed through the specific binding of 3H-DHA in the presence of ICI 118, 551 (5 x 10(-8) M), a highly selective beta 2-adrenergic receptor antagonist. In Group E, mean arterial blood pressure (MAP), heart rate (HR), and cardiac output (CO) (by thermodilution) were measured under pentobarbital sodium anesthesia before excision of hearts. [RESULTS] In Group E, CO was significantly (p less than 0.05) increased in rabbits injected with LPS (E-LPS) as compared with that in rabbits injected with SAL (E-SAL) (E-LPS; 0.75 +/- 0.02 l.min-1, E-SAL; 0.61 +/- 0.05 l.min-1, mean +/- SEM). MAP and HR were slightly decreased in E-LPS but not significantly. Maximum binding (Bmax) of 3H-DHA to BARs was significantly (p less than 0.05) decreased by 18% in myocardial membranes from E-LPS compared to E-SAL (E-LPS; 48.2 +/- 4.3 fmol/mg protein, E-SAL; 58.9 +/- 2.9 fmol/mg protein, mean +/- SEM). Similarly, Bmax of 3H-DHA to B1ARs was decreased by 18% in E-LPS, although no statistical significance was detected. In Group C, both BAR and B1 AR number was slightly, but not significantly decreased 3 h after administration of cytokines. [CONCLUSION] These data suggest that down regulation of cardiac BARs may occur during hyperdynamic stage of endotoxic shock.

Animals↗
PubMed1991

Serum gamma-seminoprotein determination in prostatic cancer.

Serum gamma-seminoprotein (gamma-Sm) was evaluated as a new marker for prostatic cancer in comparison with prostatic acid phosphatase (PAP). The sensitivity of gamma-Sm and PAP for untreated prostatic cancer was 81% and 67%, respectively. gamma-Sm showed a higher positive rate over all stages than in benign prostatic hypertrophy (BPH). There was no correlation between gamma-Sm and PAP in prostatic cancer. Improved sensitivity was obtained by simultaneous measurement of gamma-Sm and PAP. Specificity of gamma-Sm and PAP for BPH was 87% and 90%, respectively. gamma-Sm normalized after endocrine therapy for stage D2 more often than did PAP. These results indicate that gamma-Sm is another useful marker to evaluate prostatic cancer.

Acid Phosphatase↗
PubMed1991

[Clinical efficacy and safety of long-term administration of YM617 for urinary obstruction of the lower urinary tract].

The efficacy and safety of YM617, a new alpha 1-blocker, were evaluated in 121 patients with urinary obstruction of the lower urinary tract in the long-term administration study for 1 year. A total of 121 patients, i.e., 111 with benign prostatic hypertrophy (BPH), 6 with bladder neck sclerosis (BNS), 3 with BPH with BNS and 1 with female urinary obstruction, were orally administered 0.1 to 0.4 mg of YM617 once daily. Patients showing improvement of patient's impression and of subjective symptoms judged by the physician were increased until the 16th to 20th week, and it had been maintained there after. Objective findings were improved to a constant level after the 4th week. Patient's impression and subjective symptoms were improved in a certain dose-response relationship Side effects were observed in 3 patients but none were serious. YM617 proved to be useful in the treatment of patients with urinary obstruction of the lower urinary tract like BPH because it maintained the efficacy and safety in the long-term administration.

Administration, Oral↗