Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 1,099 records · Page 61Linked to original sources

PubMed1990

Predictors of duodenal ulcer healing during treatment with cimetidine.

A two phase study was performed to identify factors that influence the healing rate of duodenal ulcer. The study included an initial clinical trial in 145 patients and a second trial in a further 61 patients. All patients were prescribed cimetidine at a daily dose of 800 mg for six weeks. The factors examined were age, sex, inpatient or outpatient treatment, duration of present ulcer pain, past history of duodenal ulcer, smoking, drinking, the length of time it took for symptoms to resolve after beginning treatment, and the characteristics of the ulcers themselves. Eighty four per cent of the duodenal ulcers healed after six weeks. Using univariate and multivariate analyses, it was found that three factors indicated a significant delaying effect on healing: (1) symptoms that persisted two weeks after treatment had begun; (2) heavy smoking (20 or more cigarettes daily); and (3) severe narrowing of the duodenal bulb. Patients with none of the three unfavourable factors (n = 90) had a healing rate of 95.6% compared with patients with one (n = 45) or two or more (n = 10) factors, whose healing rates were 75.6% and 20.0% respectively (p less than 0.001). The corresponding figures in a second study were 88.9%, 55.0%, and 0%, respectively (p less than 0.001). A prognostic score based on these three factors represents the severity of duodenal ulcers with regard to healing in patients treated with cimetidine.

Adult↗

PubMed1990

Beta-2-microglobulin generation rate and clearance rate in maintenance hemodialysis patients.

We analyzed the rebound pattern of plasma beta 2-microglobulin (beta 2-m) concentration from 4 h after completion of hemodiafiltration until the start of the next treatment according to the one-pool beta 2-m kinetic model so as to determine beta 2-m generation rate and whole-body beta 2-m clearance. Next, we obtained the whole renal beta 2-m clearance as the product of renal creatinine clearance and the glomerular sieving coefficient of beta 2-m. Then, extrarenal beta 2-m clearance was calculated as the difference between whole-body beta 2-m clearance and whole renal beta 2-m clearance and renal beta 2-m clearance due to tubular absorption was taken to be the difference between whole renal beta 2-m clearance and renal beta 2-m clearance due to urinary excretion. The results showed that the higher the patients' plasma beta 2-m concentration was, the lower was the whole-body beta 2-m clearance. Moreover, in the present study, an inverse correlation was found between the following respective factors: plasma beta 2-m concentration and whole renal beta 2-m clearance; plasma concentration and renal clearance due to tubular absorption; plasma concentration and renal clearance due to urinary excretion. However, there was no correlation between plasma beta 2-m concentration and extrarenal beta 2-m clearance. The findings indicate that the variation of plasma beta 2-m concentration with the individual patient is solely attributable to the variation in residual renal function in terms of beta 2-m elimination.

Adult↗

PubMed1990

Efficient removal of albumin-bound furancarboxylic acid, an inhibitor of erythropoiesis, by continuous ambulatory peritoneal dialysis.

3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid, which cannot be removed by conventional hemodialysis due to its strong albumin binding, was found to be efficiently removed by continuous ambulatory peritoneal dialysis (CAPD), resulting in a lower serum level in uremic patients on CAPD than in those on hemodialysis. 3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid was demonstrated in vitro to inhibit erythroid colony formation. The anemia in patients on CAPD was significantly less severe than in those on hemodialysis. These results suggest that the efficient removal by CAPD of 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid, an inhibitor of erythropoiesis, is related to an improvement of anemia in patients on CAPD.

Adult↗

PubMed1990

Pharmacological study of TA-0910, a new thyrotropin-releasing hormone (TRH) analog, (I): Effects on the central nervous system by oral administration.

Effects of orally administered TA-0910, a new thyrotropin-releasing hormone (TRH) analog, on the central nervous system (CNS) were investigated and compared with those of TRH. TA-0910 shortened the duration of pentobarbital-induced sleep and antagonized reserpine-induced hypothermia at 0.3 mg/kg or more in mice. TA-0910 enhanced the spontaneous motor activity at the higher dose of 30 mg/kg in mice. The drug also activated acute spontaneous EEGs in rabbits at 1 mg/kg. TRH produced these effects at about 100 times higher doses than TA-0910. In antagonizing pentobarbital-induced sleep, the dose ratios of i.v. versus p.o. of TA-0910 and TRH were about 1/10 and 1/100, respectively. The duration of the antagonistic action of TA-0910 on pentobarbital-induced sleep in mice was about 8 times longer than that of TRH when administered orally as well as intravenously. These potent and long-acting TA-0910 effects on the CNS are discussed in connection with its biotransformation.

Administration, Oral↗

PubMed1990

Prolactin does not mediate the suppressive effect of the suckling stimulus on luteinizing hormone secretion in ovariectomized lactating rats.

The plasma LH concentration in ovariectomized lactating rats is low for 14 days postpartum, while the prolactin concentration is high during this period. We examined the effect of the inhibition of increased prolactin secretion with bromocriptine (CB-154) on the LH secretion in lactating rats ovariectomized on day 2 (day 0 = day of parturition). Blood samples were collected through an indwelling atrial cannula every day. LH levels were kept low until day 9 in lactating rats injected daily with CB-154 (0.6 mg/day, s.c.). The duration of the period during which LH secretion was suppressed was shorter in lactating rats treated with CB-154 than in saline-injected controls. The replacement with ovine prolactin by means of a mini-osmotic pump (0.3 mg/day, s.c.) in CB-154-treated lactating rats restored the duration of LH suppression. In rats deprived of their pups on day 2, the LH concentration rose immediately after removal of the pups and the LH level was not significantly different between rats treated with CB-154, ovine prolactin and saline, indicating that neither the CB-154 treatment nor the high level of prolactin alone has any effect on LH secretion in rats deprived of their pups. The present results clearly demonstrate that prolactin does not mediate the suppressing effect of the suckling stimulus on LH secretion in early lactation and support our theory that the suckling stimulus controls the LH and prolactin secretion independently at the hypothalamic level.

Animals↗

PubMed1990

[Assessment of body composition by bioelectrical impedance analysis: effects of skin resistance on impedance].

Effects of skin resistance on impedance values were studied in order to propose reliable determination of body composition in human. Analysis of the data indicated that impedance values (Z = (R2 + Xc2)0.5) varied considerably in the following conditions: 1) 230 +/- 97.8 ohms when electrodes were directly attached; 2) 490 +/- 52.5 ohms when electrodes were attached immediately after use of alcohol; 3) 584 +/- 44.1 ohms when electrodes were attached immediately after use of alcohol with electrode gel; and 4) 589 +/- 45.0 ohms when electrodes were attached in the order of elimination of skin resistance----use of alcohol----use of electrode gel. We suggest that impedance obtained by the bioelectrical impedance analysis should be measured immediately after elimination of skin resistance at least with electrode gel.

Adolescent↗

PubMed1990

[Effects of different electrodes on bioelectrical impedance values].

Effects of different electrodes on bioelectrical impedance values measured by the Selco bioelectrical impedance plethysmograph (SIF-881, Japan) were investigated using 8 adult females (age: 35.3 +/- 7.6 yr, Ht: 156.9 +/- 3.8 cm, Wt: 57.1 +/- 9.9 kg, and hydrodensitometrically determined body fat: 29.4 +/- 6.0%). The Lectec MP3000 electrode (Liberty Carton, USA) and the Bipolar electrode (Sanwa, Japan) produced significantly higher impedance values when compared to the Disposable electrode (Adovance, Japan) and the ECG electrode (Nihon Kohden, Japan). The coefficient of variation was significantly lower for the Disposable electrode (0.8%) and the ECG electrode (0.2%) than that for the Lectec MP3000 electrode (2.3%) and the Bipolar electrode (4.9%). In conclusion, the ECG electrode provides higher bioelectrical impedance values with the highest reproducibility in the assessment of human body composition by the bioelectrical impedance plethysmography.

Adolescent↗

PubMed1990

[Discriminant function analysis for evaluating the status of coronary heart disease risk].

We investigated to discriminate those individuals categorized by 1. obesity, 2. hypercholesterolemia, 3. hypertension, 4. low maximal oxygen uptake, 5. an abnormal electrocardiogram reflecting ischemic patterns, and/or 6. real sedentary life, from relatively healthier individuals without coronary heart disease (CHD) risk factors. One hundred and six Japanese women, aged 30 to 72 years, all of whom were in the postabsorptive state, were recruited in a series of tests for anthropometric and physiologic profiles both during the resting state and during the submaximal-maximal cycling exercise. Subjects were categorized into two groups--those who possessed four or more of the above 1, 2, 3, 4, 5, and 6 (high-CHD-risk group, n = 15) and apparently healthy individuals with a minimum number of risk factors (low-CHD-risk group, n = 83). Analyses of the data revealed that a combination of 8 variables extracted from among original 25 variables accurately classified 13/15 (87%) of high-CHD-risk group and 77/83 (93%) of low-CHD-risk group (mean = 90/98 or 92%) into their respective groups. The 8 variables were double product, Katsura index, waist girth, chest girth, TG, TC, and skinfold thicknesses at the subscapular and abdominal sites. Subsequent t-test identified significant differences between groups not only for VO2max, SBP and TC but also for DBP, LDLC, TG, Hb, HR, and HRmax. Most of these differences were of a much greater magnitude compared to the existing difference in chronological age. These findings suggest the usefulness and importance of anthropometric and blood lipid variables in the explanation of differences in the health status between high-CHD-risk women and their counterparts.

Adult↗

PubMed1990

[Basic studies on glass ceramics. 3. Influence on calcification of osteogenic cells in vitro].

Two established osteogenic cell lines (NY, MC 3 T3-E 1) were used in vitro to determine the biocompatibility of glass ceramics and their effect on initial calcification of osteogenic cells. Morphological study of the cell under the phase-contrast microscopy and histochemical staining were applied as follows. First, glass ceramic granules were placed in 60 mm dishes, and cells were suspended in the dishes in alpha-MEM supplemented with 10% FBS (basic medium) or medium with 50 micrograms/ml of L-ascorbic acid added. After 8 or 14 day of culturing, calcium formation was tested by von-Kossa's staining. Also, alkaline phosphatase staining was performed by the azo-dye method. As controls, cultures in dishes without glass ceramic granules were stained at the same time. The results obtained in the experimental culture were as follows. 1. Phase contrast microscopy showed that contacts with glass ceramics did not cause cellular death or degeneration. 2. In both cell cultures with the glass ceramics the von-Kossa reaction was positive as early as the 8th day. 3. The alkaline phosphatase reaction on the 8th day occurred only in MC 3 T3-E 1. The reaction was localized on fibroblastic cells which proliferated three-dimensionally around glass ceramics, and on small polyhedral cells situated relatively for apart from the ceramics. 4. On the 14th day, the MC 3 T 3-E 1 formed large nodules around the glass ceramics, and they were stained uniformly positive by von-Kossa's method. The alkaline phosphatase-positive cells extended spoke-like forms. 5. In medium with L-ascorbic acid, growth of NY was inhibited, After being cultured for 14 days, abundant von-Kossa positive reaction was found around glass ceramics in both cells. In MC 3 T 3-E1 on the 8th days, the alkaline phosphatase reaction was stronger with glass ceramics than with basic medium only. On the contrary, in the control cultures of both cells there was negative von-Kossa reaction during the culture period. The above results showed that glass ceramic granules have the biocompatibility needed for bone grafts, and they facilitated calcification of MC 3 T 3-E 1 in culture.

Alkaline Phosphatase↗

PubMed1990

Studies on the castability of Co-Cr alloy for cast plates. Part 2: Effect of form of sprue attachment to the wax pattern.

Co-Cr alloy is used more frequently than Ni-Cr alloy as a non-precious alloy for cast plates in Japan. However, since the melting point of Co-Cr alloy is very high, about 1300 degrees C, and since it oxidizes easily, a vacuum-pressure casting machine capable of melting this alloy in a reducing atmosphere has recently been developed. Using this vacuum-pressure casting machine, the authors studied the effects on the castability of Co-Cr alloy due to the form of sprue attachment to the wax pattern. The results clarified that in the vacuum-pressure casting method, the form of sprue attachment to the wax pattern has a significant effect (p less than 0.01) on the castability of Co-Cr alloy.

Chromium Alloys↗

PubMed1990

Phenotypic characterization of lymphocytes infiltrating synovial tissue from patients with rheumatoid arthritis: analysis of lymphocytes isolated from minced synovial tissue by dual immunofluorescent staining.

The phenotypic markers of mononuclear cells in synovial tissue from 19 patients with active rheumatoid arthritis (RA) were identified by a dual immunofluorescent method. The mononuclear cells were isolated from synovial tissue by mechanical disaggregation and an enzymatic digestion technique. The results revealed a marked reduction in CD4+2H4+ cells (suppressor inducer T cells) and an increment in CD4+4B4+ cells (helper T cells) among CD4+ cells in synovial tissue. The percentage of CD8+CD11b+ cells (suppressor effector T cells) was significantly lower in synovial tissue than in peripheral blood from patients with RA, resulting in an increased percentage of CD8+CD11b-- cells (cytotoxic T cells). The synovial tissue had higher percentages of pan B cells (B1+ cells), differentiated B cells (B1+B2-- cells) and plasma cells (PCA-1+ cells). These findings suggest that a combination of the increment in helper T cells, the reduction in suppressor T cells, and the increment in differentiated B cells may lead to excessive production of autoantibodies.

Adult↗

PubMed1990

[Epidemiological studies of air pollution and health effects in areas near roadways with heavy traffic in Tokyo].

Recent concern regarding health effects of air pollution in Japan has concentrated mainly on traffic-induced air pollution and its health effects in large cities. In Japan, where many people in large cities have been living near major roadways, the increase of automobile exhaust due to heavy traffic congestion will predictably cause a greater impact on people living near major roadways. We surveyed the characterization of residential suspended particulate matter (SPM) and nitrogen dioxide (NO2) concentrations along the major roadways in Tokyo, along with a health survey on the respiratory conditions of residents living in the same area, to examine the relationships between indoor pollutant levels, prevalence of respiratory symptoms and distance from roadways. The environmental monitoring was conducted in five phases. Using a newly developed SPM sampler and NO2 filter badge, continuous 4 day (96 hours) measurements were conducted in two hundred residential homes for four weeks. NO2 was measured in the living room, kitchen and outside of each home, while SPM was monitored in the living room. Health information was collected in October 1987 using ATS-DLD self-administered questionnaires. Of the 1,093 homes investigated, responses from 805 homes were received. The following results were obtained. SPM and NO2 concentrations showed large variations. Indoor pollution levels mostly depended on indoor sources, i.e. cigarette smoking and unventilated space heaters, and the effects of those indoor sources were influenced by the building structure with respect to air tightness. An association between increase in pollutant levels and the distance from the roadway was observed. However its effect is small compared to indoor source effects. The prevalence rate of respiratory symptoms was higher in those areas nearest roadways with heavy traffic both in children and adults. These results suggest the presence of a relationship between automobile exhaust and health effects.

Adult↗

PubMed1990

[Suppressive effect of Saibokuto on Dermatophagoides farinae (Df) antigen-induced IL2 responsiveness of lymphocytes from asthmatic children].

The effect of Saibokuto on induction of antigen specific IL2 responsiveness was studied. Saibokuto suppressed the induction of IL2 responsiveness induced by Dermatophagoides farinae (Df) antigen in peripheral blood mononuclear cells from patients with bronchial asthma. Saibokuto-pretreated adherent cells failed to present Df antigen to non-adherent responding T cells for induction of their IL2 responsiveness. The same dose of Saibokuto had no impact on non-adherent cells. Saibokuto also suppressed the induced IL2 responsiveness of lymphocytes from the same patients on stimulation wit PPD, but not with Con A. These combined data suggests that Saibokuto has a weak immunosuppressive effect on Df induced IL2 responsiveness of lymphocytes from asthmatic children. Effect of Saibokuto on induction of antigen specific IL2 responsiveness was studied. Saibokuto suppressed the induction of IL2 responsiveness induced by Dermatophagoides farinae (Df) antigen in peripheral blood mononuclear cells from patients with bronchial asthma. Saibokuto-pretreated adherent cells failed to present Df antigen to non-adherent responding T cell for induction of their IL2 responsiveness. Non-adherent cells had no impact by the same dose of Saibokuto. Saibokuto also suppressed the induced IL2 responsiveness of lymphocytes from the same patient on stimulation with PPD, but not Con A. These combined data suggest that Saibokuto has a weak immunosuppressive effect on Df induced IL2 responsiveness of lymphocytes from asthmatic children. Effect of Saibokuto on induction of antigen specific IL2 responsiveness was studied. Saibokuto suppressed the induction of IL2 responsiveness induced by Dermatophagoides farinae (Df) antigen in peripheral blood mononuclear cells from patients with bronchial asthma. Saibokuto-pretreated adherent cells failed to present Df antigen to non-adherent responding T cell for induction of their IL2 responsiveness. Non-adherent cells had no impact by the same dose of Saibokuto. Saibokuto also suppressed the induced IL2 responsiveness of lymphocytes from the same patient on stimulation with PPD, but not Con A. These combined data suggest that Saibokuto has a weak immunosuppressive effect on Df induced IL2 responsiveness of lymphocytes from asthmatic children.

Animals↗

PubMed1990

[Frequency and prognostic features of rheumatoid patients with remission-inducing agents--a comparison of different kinds of medication].

Recently, the disease activity has been believed to be effectively controlled by remission inducing agents such as gold salt and D-penicillamine in rheumatoid arthritis. However, there remain some doubts whether the prognosis of RA has been improved by these drugs or not. The frequency of complete remission in RA patients and their special features were studied to know the real state of the remission of RA under the present treatments. The subjects under investigation were 466 RA patients who were treated with remission-inducing agents for one to eight years. There were 90 male and 376 female patients diagnosed as definite or classical RA. Complete remission according to ARA criteria (Pinals R.S. et al. 1981) was noted in 33 (7.1%) of the 466 patients. However, relapse of the disease activity was observed in five patients during an observation period of two years on average. The followings were noted as the clinical and laboratory features of 26 cases with complete remission which could be observed for more than six months. A breakdown on sex revealed that the remission rate was 13.3% in male patients, compared to 5.6% in female patients. Duration of the disease for these complete remission cases was shorter for males than for females. Clinical examination of the cases with complete remission revealed that the most of them had no family history of RA, as well as no rheumatoid nodule or hip contracture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

[Effect of oral sorbent, AST-120, on serum concentration of indoxyl sulfate in uremic rats].

Indoxyl sulfate is a metabolite of tryptophan. Indole is synthesized in intestine from tryptophan by intestinal bacteria. The absorbed indole is converted to indoxyl sulfate through indoxyl in liver. Serum concentration of indoxyl sulfate is markedly increased as an inhibitor of drug-binding in uremic patients as compared with healthy subjects. Since indoxyl sulfate is bound to serum albumin, it cannot be removed efficiently by hemodialysis, and it tends to accumulate in uremic serum. To determine if oral sorbent, AST-120, could adsorb indole in intestine and then decrease serum concentration of indoxyl sulfate, it was administered to nephrectomized uremic rats. Serum concentration of indoxyl sulfate was markedly decreased in uremic rats fed with oral sorbent as compared with control uremic rats. However, serum concentrations of creatinine and urea nitrogen were not significantly decreased in the uremic rats fed with oral sorbent as compared with the control uremic rats. Serum concentration of tryptophan was not decreased but rather increased in the uremic rats fed with oral sorbent as compared with the control uremic rats. Concentration of indoxyl sulfate in bile of a uremic rat was much lower than that in the uremic serum, suggesting that the adsorption of indoxyl sulfate in intestine is not a major mechanism of decreasing the serum concentration of indoxyl sulfate. These results demonstrate that oral sorbent, AST-120, can decrease serum concentration of indoxyl sulfate in uremia due to adsorption of indole in intestine.

Administration, Oral↗

PubMed1990

[Anti-CD45R antibody-treated normal lymphocytes respond to interleukin 2 (IL2) after stimulation by allergens].

Interleukin 2 (IL2) responsiveness was specifically induced by Dermatophagoides farinae (Df) antigen in Df-sensitized lymphocytes from asthmatic children, but not in normal lymphocytes. Df-induced IL2 responsiveness was also observed in normal lymphocytes pretreated (Day 0) with anti-CD45R antibody, which recognize suppressor inducer subset among CD4+ T cells. However anti-CD45R antibody was no longer effective when the lymphocytes were cultured for more than one day with the antigen, suggesting its effect in the initial phase of the reaction. The intensity of the response induced in normal lymphocytes by the anti-CD45R was comparable to that of the patients sensitized to the nominal antigen. The response of the patients was no longer augmented by the anti-CD45R antibody. Taken together, these data suggest that even normal lymphocytes have potentiality to elicit Df-induced IL2 responsiveness and it is probably derepressed by inhibiting suppressor inducer subset with the anti-CD45R antibody. Also suggested is a defective suppressor inducer activity in the lymphocytes which may lead to hyperreactivity to allergens in asthmatic children.

Allergens↗

PubMed1990

Morphological features of blood access stenosis and results of noninvasive angioplasty.

We investigated a connection between the results of noninvasive angioplasty for the blood access stenosis and its morphological features in 37 dialysis cases. In 3 cases presenting stenosis in the original artery, the area could not be dilated by noninvasive techniques. In 4 cases with stenosis in the arterialized vein downstream of the needle insertion points for extracorporeal circulation, 3 showed long-term dilatation by the procedures. In 30 cases having stenosis upstream of the points, 16 showed long-term dilatation. In the unsuccessful cases, the angle formed between the axes of the stenosed portion and the normal vessel was over 39 degrees, and the distance between the anastomosis and the stenosed portion was less than 11 mm.

Angioplasty, Balloon↗

PubMed1990

An immunohistochemical study of lung carcinomas using a monoclonal antibody which specifically reacts to basal cells.

Sixty-three primary lung carcinomas were examined immunohistochemically using a monoclonal antibody, KP8D4, which reacted specifically to basal cells in the lung. Seven of ten squamous cell carcinomas, four of 41 adenocarcinomas, two of five large cell carcinomas, and one adenosquamous carcinoma were reactive with KP8D4; however, four small cell carcinomas, one mucoepidermoid carcinoma, and one carcinoid tumor were all not reactive to this antibody. Four adenocarcinomas stained by KP8D4 were Clara cell type adenocarcinomas, and two of them also revealed reactivity to surfactant apoprotein in the same cells labeled with KP8D4. These results indicate that carcinomas positive to KP8D4, including adenocarcinomas at the lung periphery, expressed phenotypically the same protein which was specifically recognized in the basal cells, suggesting that the basal cells possessing a multipotent capability of differentiation are a possible candidate of progenitor cells of lung carcinomas, including peripheral type lung carcinomas.

Adenocarcinoma↗