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Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 559 records · Page 31Linked to original sources
PubMed1994

Analysis of the uveitogenic determinant in repeat structure of retinal interphotoreceptor retinoid-binding protein (IRBP).

IRBP is a glycolipoprotein with a four-fold partially homologous repeat structure approximately 300 residues in length, and is one of the retinal antigens capable of inducing experimental autoimmune uveoretinitis (EAU) in susceptible animals by their active immunization. The most immunopathogenic peptide of bovine IRBP for EAU in Lewis rats is reported to be the sequence 1169-1191 (PTARSVGAADGSSWEGVGVVPDV) with two immunogenic motifs common to T cell epitopes (underlined). The uveitogenic site of peptide 1169-1191 was localized at the carboxyl terminus (peptide 1182-1191) and not at the amino acid terminus (peptide 1169-1182). Repeat peptides of sequence 1179-1191 containing the four homologous residues (1182W, 1186G, 1187V and 1189P), that is the peptides 271-283, 579-591 and 880-892, all elicited EAU. Peptide 579-591 could not stimulate proliferation of lymphocytes from rats immunized with IRBP, but had the capacity to adoptively transfer EAU. The role of the homologous residues was examined using analogues of the uveitogenic peptide 1182-1194, in which each homologous residue was substituted by glycine (G) or leucine (L) (1182W-->G, 1186G-->L, 1187V-->G, and 1189P-->G). One analogue (1186G-->L) strongly diminished the ability to induce EAU, while the other three analogues completely abolished the ability, indicating that these homologous residues were essential for the induction of EAU. In addition, the uveitogenic peptides tested in this study were found not to contain the major epitope for antibody production.

Amino Acid Sequence↗
PubMed1994

Recovery period from ureteral obstructions of different duration and severity in the rat kidney.

The relationship between the period for recovery from hydronephrosis and the characteristics of the obstruction still needs to be clarified. In rat kidney the left ureter was completely obstructed for 3, 7, 14 and 21 d and the renal function was measured by renal scintigraphy using 99mTC-dimercaptosuccinic acid 3, 7 and 14 d after the obstruction was removed. In addition, recovery from unilateral partial obstruction (PO) of different degrees of severity for 7 d was examined. The kidneys with very mild PO recovered within 3 d and those with a very long period of complete obstruction (CO) did not exhibit any significant recovery. However, most of the kidneys with CO of various durations and those with 7 days PO of various degrees of severity exhibited maximum recovery 7 d after the release of the obstruction. This study suggests that the period required for maximum recovery from hydronephrosis is usually constant, unless the obstruction is too mild to cause any damage or too long to permit any recovery.

Animals↗
PubMed1994

Examination of the tridimensional personality hypothesis of alcoholism using empirically multivariate typology.

Cloninger (1987) has hypothesized a tridimensional personality theory for two types of alcoholism, type 1 and type 2, that exhibit opposing clinical characteristics and personality traits. The Tridimensional Personality Questionnaire (TPQ) is designed to test this hypothesis on three independent dimensions--novelty seeking (NS), harm avoidance (HA), and reward dependence (RD)--to evaluate the personality trait. We examined the tridimensional personality hypothesis by comparing TPQ scores between two empirically derived multivariate types of alcoholism. The present study included 191 male subjects with alcoholism. A cluster analysis was conducted using clinical characteristics, and two empirical types, type A and type B, were identified. Type A is similar to Cloninger's type 1 and type B is similar to type 2. The TPQ scores given to these two empirical types were compared. Scores on the NS and RD scales were in good agreement with the hypothesis, whereas the HA score was discordant with the hypothesis. HA is highly correlated with the depression scale score that is elevated in type B. We discussed the possibility that type B, which may be called a familial early-onset alcoholism, is related to character spectrum disorder.

Adult↗
PubMed1994

The role of hepatitis C virus in hepatocellular carcinoma in Japan.

Increasing numbers of patients with hepatocellular carcinoma (HCC) have been reported in Japan. In this paper, we investigated the role of hepatitis C virus (HCV) in HCC and the reason for the increase, using patients admitted to our university hospital from 1945 to 1992. 99 (73%) of 135 patients with HCC were positive for anti-HCV. Prospective studies demonstrated that 22 of 158 (14%) patients with chronic hepatitis C, and 31 of 70 (44%) cirrhotic patients with anti-HCV developed to HCC during the follow-up period (10.1 +/- 3.3 and 7.3 +/- 3.5 years, respectively). Prolonged survival of cirrhotic patients during past decades would also contribute to the increasing number of HCC cases as well as the number of HCV infections in Japan.

Carcinoma, Hepatocellular↗
PubMed1994

Inhibitory effects of transforming growth factor-beta 1 on androgen-induced development of neonatal mouse seminal vesicles in vitro.

The effects of transforming growth factor-beta 1 (TGF beta 1) on the development of seminal vesicles (SVs) of neonatal mice were investigated in vitro. SVs from 0-day-old male mice were cultured for 2-8 days in serum-free, chemically defined medium with or without 5 alpha-dihydrotestosterone (DHT) at 10(-8) M in the presence or absence of TGF beta 1. Before culture, SVs from 0-day-old mice had no epithelial branches. SVs cultured in medium with DHT formed numerous epithelial branches after day 2 of culture, whereas epithelial branching did not occur in SVs cultured without DHT. The addition of TGF beta 1 (10 ng/ml) to DHT-containing medium almost completely inhibited the formation of epithelial branches. However, the removal of TGF beta 1 from DHT-containing medium on day 2 or 4 of culture initiated the formation of epithelial branches. TGF beta 1 (10 ng/ml) decreased [3H]thymidine labeling indices of both epithelium and mesenchyme of SVs cultured in medium with DHT during 8 days of culture, an effect that was reversed after the removal of TGF beta 1 from the medium on day 2 or 4 of culture. In contrast, TGF beta 1 (10 ng/ml) did not affect the labeling indices of either epithelium or mesenchyme of SVs cultured in medium without DHT. TGF beta 1 (10 ng/ml) also suppressed the normal increase in protein and DNA contents of SVs cultured in medium with DHT, whereas it did not reduce protein or DNA contents of SVs cultured in medium without DHT. The present study indicates that androgen-dependent growth of the SV can be reversibly inhibited by TGF beta 1, whereas androgen-independent growth of the SV is insensitive to TGF beta 1.

Androgens↗
PubMed1994

An improved method for the purification of human erythropoietin with high in vivo activity from the urine of anemic patients.

An improved method for the purification of human erythropoietin with high in vivo activity from urine was developed. This method involved ion-exchange, gel permeation, affinity chromatography, and reverse-phase chromatography but did not involve any stabilizing procedures. The purified human urinary erythropoietin showed a single broad band with a molecular weight between 37000 and 39000 Da on sodium dodecyl sulfate polyacrylamide gel electrophoresis, and had an in vivo specific activity of 160000 IU/mg comparable to that of human erythropoietin produced in recombinant Chinese hamster ovary cells. We found that omission of the phenol treatment and ethanol precipitation which are usually used in the purification of human urinary erythropoietin greatly improved the biological activity of the final product. Phenol treatment followed by ethanol precipitation did not affect the amino acid composition but decreased the apparent molecular weight and N-acetylglucosamine content of human urinary erythropoietin. These findings suggest that phenol treatment followed by ethanol precipitation does not restore erythropoietin with high branched sugar chains which would have high in vivo specific activity as reported previously (M. Takeuchi, et al. (1989) Proc. Natl. Acad. Sci. U.S.A., 86, 7819-7822).

Anemia↗
PubMed1994

Association of a nocturnal rise in plasma alpha-atrial natriuretic peptide and reversed diurnal blood pressure rhythm in hospitalized normotensive subjects with non-insulin dependent diabetes mellitus.

Diurnal changes in plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA) and plasma aldosterone as related to those in blood pressure (BP) were studied under hospital conditions in 18 diabetic subjects without proteinuria and 8 age-matched control subjects. Of 18 diabetic subjects, 10 had a normal diurnal BP rhythm with the peak value in the afternoon (group 1) and 8 had a reversed BP rhythm with the peak value during the night (group 2). Autonomic dysfunction estimated by measuring orthostatic BP and heart-rate changes and beat-to-beat heart-rate variations was more pronounced in group 2 than in group 1. Fasting plasma glucose and HbA1c were similarly high in both diabetic groups. Group 1 showed modestly elevated mean 24-h MBP and plasma ANP levels, modestly low mean 24-h PRA and plasma aldosterone levels, and a lack of diurnal ANP changes similar to that in controls. Group 2 showed markedly elevated mean 24-h BP and plasma ANP levels, markedly low mean 24-h PRA and plasma aldosterone levels, and nocturnal rises in plasma ANP and BP. PRA and plasma aldosterone exhibited circadian rhythms with their peak values found in the early morning in all three groups. The daytime/overnight excretion ratios of sodium and water were normal in group 1 and low in group 2. These results indicate that diurnal changes in plasma ANP, PRA and plasma aldosterone are altered in diabetic subjects with normal and reversed diurnal BP rhythms, predominantly in the latter.

Aged↗
PubMed1994

[Clinical results of percutaneous pyeloplasty for ureteropelvic junction obstruction: 5 years follow-up].

We performed percutaneous endopyeloplasty on 20 patients between February, 1988 and July, 1993. Eighteen patients had primary and two had secondary ureteropelvic junction (UPJ) obstructions. There were 15 female and 5 male patients, whose ages ranged from 14 to 77, with an average of 43.6. The length of the follow-up after pyeloplasty ranged from 4 to 69 months with an average of 28.7 months. Among the 20 patients, there were 4 high insertion type cases, a bifid renal pelvis in one case and one case combined with a renal stone. Incisions were made with a hook-shaped cold knife and Ono's transpelvic extraureteral approach was used in most patients. Catheters were placed at the upper and the lower of renal pelvis in the patient with a bifid renal pelvis. In the case with a renal stone, pyeloplasty was successively performed after percutaneous nephrolithotomy in a single session. An endopyelotomy stent (14 Fr) was indwelled for 6 weeks in all patients except one. All patients had a low grade fever and abdominal pain for a few days after their operations, but there were no major complications. In nineteen patients (95%), the symptoms improved and their obstructive patterns disappeared or improved during follow-up. Complete ureteral stricture was found in one case at the removal of the stent and open pyeloplasty was performed. Percutaneous endopyeloplasty is a safe and useful technique, but further evaluation and/or better techniques are needed for avoiding recurrence of obstruction.

Adolescent↗
PubMed1994

[Extracorporeal shock wave lithotripsy in a patient with hemophilia A. A case report].

We treated a 25-year-old hemophilia A patient (FVIII:C activity 2%) with left ureteral stone by means of extracorporeal shock wave lithotripsy under replacement therapy of concentrated Factor VIII material. The patient was attacked by sudden onset of left renal colic with gross hematuria on the 12th postoperative day. Renal ultrasonography and computed tomography demonstrated subcapsular bleeding of the left kidney. In spite of usual antihemophiliac replacement therapy, bleeding was extended from the retroperitoneal space to intraperitoneal and intrapleural space because potent Factor VIII inhibitors (14 Bethesda Unit) was produced. After embolization of the left renal artery, double filtration plasmapheresis and bypassing therapy using prothrombin complex concentrate were performed effectively to save the patient's life.

Adult↗
PubMed1994

Effect of NKH477, a new water-soluble forskolin derivative, on arterial-ventricular coupling and mechanical energy transduction in patients with left ventricular systolic dysfunction: comparison with dobutamine.

We examined the effects of a novel water-soluble forskolin derivative, NKH477 (0.5 microgram/kg/min), on arterial-ventricular (A-V) coupling and mechanical energy transduction from heart to circulatory bed in comparison with those of dobutamine (3 micrograms/kg/min) in 8 patients with left ventricular (LV) systolic dysfunction using a conductance catheter method. A-V coupling was assessed as the ratio of the effective arterial elastance (E(a)) to the slope of the end-systolic pressure-volume relation (ESPVR) (E(max), left ventricular contractility index), and the ratio of mechanical energy transduction was obtained as the fraction of PV area (PVA) comprised of stroke work (SW). E(max) (2.59 mm Hg/ml/m2), E(a)/E(max) (1.62), and SW/PVA (0.58) were impaired in control contractile state. NKH477 increased Emax to the same extent as dobutamine. E(a) decreased with NKH477 but not with dobutamine. As a consequence, the decrease in E(a)/E(max) with NKH477 was greater than that with dobutamine (52 vs. 47%, p < 0.05); the increase in SW/PVA with NKH477 was also greater than that with dobutamine (28 vs. 21%, p < 0.05). These findings suggest that NKH477 may be a superior alternative to dobutamine in A-V coupling and mechanical energy transduction in patients with LV systolic dysfunction.

Adult↗
PubMed1994

[Light-induced retinal damage in pigmented rabbits--1. Histopathological observations of the natural course of healing].

Pigmented rabbits were exposed for 2 hours to xenon light to evaluate the light induced retinal damage clinicopathologically. The xenon light was passed through a heat filter to avoid the influence of long waves, and through the fundus contact lens on the cornea to avoid focusing the light on the retina. No abnormal findings were detected in the retina in fluorescein angiography immediately after the light exposure. Three hours later, hyperfluorescence was found in the center of the exposed area and gradually grew worse. This was most marked twelve hours later. After 6 days, granular hyperfluorescence appeared at the edge of the damaged area and in 2 weeks the whole damaged area showed granular hyperfluorescence. Histopathologically, immediately after the light exposure, slight changes appeared in the retinal pigment epithelium (RPE). Twelve hours later, the cytoplasm of the RPE was edematous, and in 24 hours the RPE became necrotic, but the outer segments of the photoreceptor cells appeared intact. After 6 days, the RPE showed double layering, many macrophages were found in the subretinal space, and the outer segments of the photoreceptor cells were severely damaged. The RPE was primarily damaged and photoreceptor cells were damaged subsequently by xenon light without long waves.

Animals↗
PubMed1994

Tissue-specific suppressor T cells involved in self-tolerance are activated extrathymically by self-antigens.

Autoimmune prostatitis developed spontaneously in (C57BL/6N x A/J)F1 (B6A) mice, when thymectomy (Tx) was conducted on day 3 after birth (Tx-3). The lesion could be prevented by a single injection of CD4+ spleen cells (4 x 10(6)) from normal males, but not from normal females or newborn orchidectomized (Orx-0) mice. However, when spleen cells were obtained from Orx-0 mice that had received a dihydrotestosterone (DHT) pellet when adult to develop a mature prostate, prostatitis could be prevented, suggesting that immune tolerance to prostate antigen(s) is maintained by a CD4+ tissue-specific suppressor T cell (Ts) population(s), which is activated by a specific autoantigen(s) in the mature prostate. The result that even CD4+ cells from Orx-0 mice that were thymectomized as adults and treated thereafter with DHT were effective for prevention of prostatitis suggests that activation of this Ts population takes place in the peripheral lymphoid organs, and that it maintains peripheral tolerance to autoantigen in the prostate of these mice and probably also in normal mice.

Animals↗
PubMed1994

[Light-induced retinal damage in pigmented rabbit--2. Effect of alpha-tocopherol].

We have reported previously that xenon light exposure without long waves primarily damages the retinal pigment epithelium (RPE) of pigmented rabbits. Alpha-tocopherol, which is a free radical scavenger, was administered systemically to pigmented rabbits before light exposure in order to evaluate the protective effect against retinal light damage. In fluoresceine angiography, at 12 hours after the light exposure, diffuse and marked hyperfluorescence was seen in the lower portion of the retina adjacent to the optic disc in the untreated group, and slight hyperfluorescence in a small area was seen in the treated group. Histopathologically, the RPE became necrotic 12 hours after the light exposure in the untreated group. In the treated group, only slight damage appeared in the RPE 12 hours after the light exposure. The light-induced retinal damage, particularly in the RPE, was remarkably reduced by administration of alpha-tocopherol before the light exposure.

Animals↗
PubMed1994

[Therapeutic potential of sparfloxacin for preventing mycobacterial infections].

We studied the therapeutic potential of utilizing sparfloxacin (SPFX), a newly developed quinolone, to prevent various mycobacterial infections. The in vitro activity of SPFX as a preventive agent for various mycobacteria was determined using the actual count method on Ogawa egg medium. The minimal inhibitory concentrations (MICs) of SPFX were as follows: ofloxacin-sensitive M. tuberculosis, 0.16-0.32 microgram/ml; ofloxacin-resistant M. tuberculosis, 0.63-2.5 micrograms/ml; M. avium; 0.63-10 micrograms/ml (MICs were equal or less than 1.25 micrograms/ml in seven out of 11 strains); M. intracellulare, 2.5-10 micrograms/ml (MICs were equal or more than 10 micrograms/ml in 17 out of 23 strains); M. kansasii, < or = 0.08-0.16 microgram/ml; M. fortuitum, < or = 0.08 microgram/ml; M. chelonae subsp. abscessus, > 10 micrograms/ml; M. chelonae subsp. chelonae, 0.63 microgram/ml; M. scrofulaceum, < or = 0.08 microgram/ml; M. nonchromogenicum, 1.25 micrograms/ml; M. xenopi, < or = 0.08 microgram/ml; M. gordonae, < or = 0.08 microgram/ml. The average serum concentrations of SPFX during the period of multiple oral administration (200 mg once a day) were 0.35 +/- 0.16 microgram/ml before administration, 0.67 +/- 0.32 microgram/ml after one hour, 1.13 +/- 0.21 microgram/ml after two hours, 1.27 +/- 0.32 microgram/ml after four hours and 1.31 +/- 0.34 micrograms/ml after six hours. These results indicate that SPFX has a strong therapeutic potential to prevent infections due to M. tuberculosis, M. kansasii, M. fortuitum, M. chelonae subsp. chelonae, M. scrofulaceum, M. xenopi and M. gordonae. Moreover, it may be expected to be a promising agent against infections due to ofloxacin-resistant M. tuberculosis, M. avium and M. nonchromogenicum.

Anti-Infective Agents↗
PubMed1994

[Henoch-Schönlein purpura associated with pulmonary tuberculosis].

A 34-year-old man was admitted to our hospital because of cough and fever. Chest radiograph showed multiple cavities mainly on the right lung. His sputum was positive for acid-fast bacilli on smear, and he was treated with daily isoniazide, rifampicin and streptomycin. Antituberculous treatment was successfully performed, so acid-fast bacilli of his sputa disappeared on smear and culture. Five months later, he developed a purpuric lesions over both legs accompanied by low grade fever and arthralgia, but proteinuria and abdominal pain could not be observed. Laboratory findings showed a normal platelet count and a normal bleeding time. High levels of serum IgG, IgA, C3 and C4 were evident. ASLO and ASK titer were elevated and they markedly increased within two weeks. A direct invasion of the vessel wall by tubercle bacilli is deniable because antituberculous treatment was successfully continued. Henoch-Schönlein purpura was diagnosed judging from these findings. High levels of ASLO and ASK suggest a preceding streptococcal infection for developing purpura but a possible infectious focus could not be identified. He was treated with 15 mg of prednisolone daily for two weeks and the lesion was subsided. The effect of prednisolone suggests that a subsequent antigen-antibody interaction caused by a streptococcal infection may participate in the formation of the purpura.

Adult↗
PubMed1994

[A case of partial atrioventricular canal with discrete subvalvular aortic stenosis worsened 3 years after the replacement of the mitral valve].

The extension of the left ventricular outflow tract is provoked by a partial atrioventricular canal, and is easy to cause stenosis after a radical operation and/or a replacement of the left atrioventricular valve because of its anatomical structure. This report shows a case of a partial atrioventricular canal with a discrete subvalvular aortic stenosis which was worsened three years after the replacement of mitral valve. In this case the left ventricular outflow tract obstruction (LVOTO) had been found before the replacement of mitral valve but it was kept observing without surgical treatment because the degree was judged slight. Subvalvular aortic stenosis was worsened three years after the replacement. It was suspected that the stenosis developed because of the proliferation of heterologous tissue by a turbulent flow of a site of stenosis. For this diagnosis, the transesophageal echocardiography was very effective, and in this case the cause of LVOTO is uncertain, so a careful observation is necessary for it.

Adult↗