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Biomedical subjects

T Ishikura

Publications and source records attributed to T Ishikura.

At least 19 recordsLinked to original sources
PubMed2003

Normal development of the gut-associated lymphoid tissue except Peyer's patch in MyD88-deficient mice.

MyD88 is a key adaptor molecule for signalling via Toll-like receptors (TLRs) and the response to gut commensal microbes. To investigate the role of TLRs/MyD88 pathway in the development of the gut-associated lymphoid tissue (GALT), we examined the development of Peyer's patches (PPs) and cryptopatch (CP), and also one of effector compartment, intraepithelial lymphocyte (IEL) in MyD88-/-, TLR2-/- and TLR4-/- mice. In MyD88-/- mice, the organogenesis of PPs was not disturbed. However, PPs in 2-week-old MyD88-/- mice were significantly smaller than those in MyD88+/- mice. Also, in 2-week-old TLR4-/-, but not TLR2-/- mice, PPs did not develop rapidly. The development of PPs in MyD88-/- and TLR4-/- mice was completely recovered in 10 weeks. PP cells from MyD88-/- mice showed significant decrease in proliferation when stimulated with lipopolysaccharide. The development of CP and IEL was also normal in 10-week-old MyD88-/- mice. These results suggest that the TLRs/MyD88 pathway might be involved in the development of PPs only at early postnatal stage, and TLRs/MyD88-independent signalling is critically involved in the development of GALT in adult mice.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Biomechanical analysis of weight bearing force and muscle activation levels in the lower extremities during gait with a walker.

The biomechanics of using a walker for the partial weight bearing gait and as a method for gradually increasing the muscle activation level were examined with a force plate and surface electromyography. The results showed that the weight bearing force during gait with a walker is determined by the flexion angle of the hip joint. The value remains constant for each stride, indicating that a walker can be used for the partial weight bearing gait. Moreover, the muscle activation levels in the rectus femoris muscle and biceps femoris muscle per unit time during normal gait and gait with a walker with varying hip joint flexion angles were found to be correlated with the weight bearing force and to be constant for each stride. In addition, the muscle activation level was consistent with the level observed during the open kinetic chain resistance exercise with a specific loading level. These findings suggest that normal gait and gait with a walker may be applicable as a method for gradually increasing the muscle activation level.

Activities of Daily Living↗
PubMed2000

Compensatory coordination of release parameters in a throwing task.

The consistency and coordination of release parameters in ball-throwing movements were investigated. The authors used a newly developed index of coordination for release parameters (ICRP) that quantifies the degree of improvement of performance consistency caused by compensatory relationships among parameters (i.e., not caused by consistency of parameters). Eight participants practiced for 150 trials, with the nondominant hand, a ball-throwing task aimed at a stationary target. The magnitude of the ball-release velocity vector, among release parameters, as well as the performance was found to become consistent with practice. The ICRP score suggested that the release parameters were complementarily coordinated with one another, and that the coordination improved with practice. Those results indicate that compensatory relationships among varying release parameters contribute to reducing the variability of performance in a ball-throwing task whose goal is accuracy.

Adult↗
PubMed1998

Prospective evaluation of a new anti-ulcer agent, ecabet sodium, for the treatment of Helicobacter pylori infection.

BACKGROUND: A new anti-ulcer agent, ecabet sodium, is active against Helicobacter pylori. AIM: To assess the efficacy of ecabet sodium for the eradication of H. pylori in patients with gastroduodenal diseases. METHODS: In a prospective, randomized and controlled study, patients infected with H. pylori were assigned to one of the following two groups: group LA, who received lansoprazole 30 mg o.d. + amoxycillin 500 mg q.d.s. after meals for 2 weeks, and group LAE, who received lansoprazole 30 mg o.d. + amoxycillin 500 mg q.d.s. + ecabet sodium 1000 mg b.d. after meals for 2 weeks. H. pylori status was determined before and at least 4 weeks after the therapy by rapid urease test, histology and a urea breath test. RESULTS: Of 101 patients (mean age 53 years, range 17-77 years, M/F: 68/33) enrolled in the study, 97 patients completed the protocol. Four patients were withdrawn because of diarrhoea (three from group LA) and skin rash (one from group LAE). The eradication of H. pylori was achieved in 28/48 (58%) patients in group LA and 38/49 (78%) patients in group LAE. The rate of eradication of H. pylori produced by the LAE treatment was significantly higher than that produced by the LA treatment. Side-effects appeared in two patients (malaise 1, skin rash 1) in group LAE and in seven patients (diarrhoea 6, dizziness 1) in group LA. These side effects disappeared spontaneously with cessation of the treatment. CONCLUSIONS: Ecabet sodium in combination with lansoprazole and amoxycillin increased the rate of eradication of H. pylori. Ecabet sodium appeared to reduce the incidence of diarrhoea as a side-effect of the dual LA therapy.

Abietanes↗
PubMed1998

An attempt to distinguish between two reversal processing strategies for learning modeled motor skill.

The first purpose was to examine the effects of reversal processing strategy of visual information on recognition and acquisition of a sequential gross movement task. The second purpose was to examine the relationship between a measure of reversal processing strategy and movements during eye fixation. 24 undergraduates were assigned into one of three conditions, a Reversal-emphasized condition in which subjects were instructed to recognize the movement correctly from a reversed angle, a Recognition-emphasized condition in which subjects were instructed to recognize the movement correctly, and a Recall-emphasized condition in which subjects were instructed to reproduce the movement correctly. Subjects observed stimuli with the model facing them. Following observation, the subjects' recognition of stimuli was tested with model facing towards (Facing Angle) and facing away (Rear Angle). Recall tests were carried out after the two recognition tests. Analysis indicated that accuracy and response time on recognition tests improved under each condition, but there were no other effects. The Reversal-emphasized condition showed significantly greater modeling effect than the other conditions. Movements during eye fixation were very similar among conditions.

Adult↗
PubMed1995

Effects of angle of model-demonstration on learning of motor skill.

The purpose was to examine the effects of three different demonstrations by a model on acquisition and retention of a sequential gross movement task. The second purpose was to examine the relationship between reversal processing of visual information about skills and coding of skill information. Thirty undergraduates (15 men and 15 women) were assigned into one of three conditions, Objective condition which demonstrated the task with the model facing the subject. Looking-glass condition in which the skill was demonstrated with the model facing the subject who viewed the performance opposite the right and left directions in executing the task, and the Subjective condition in which the subject observed the model from the rear. Number of immediate recall tests required to accomplish the sequential movements completely and the sum of the performance points for reproduced movements at each delayed recall test (1 day, 7 days, and 5 mo. after the immediate recall test) were employed. Analysis indicated the Subjective condition produced a significantly greater modeling effect in immediate recall of the movements than the Looking-glass condition. Retention of the acquired skills was almost equal under the three conditions.

Adult↗
PubMed1994

Alopecia areata associated with haloperidol.

A patient with a 7-year history of depression relapsed after self-discontinuation of antidepressant drugs. He was admitted to our hospital and re-administered amoxapine 150 mg. p.o. per day, and further given haloperidol 5 mg i.m. or p.o. per day because he was suicidal and excited. One month later, an area of alopecia was found on the back of his head. Immediately, he received dermatological treatment. The psychotropic drugs were continued, but the hair loss was unchanged after one month. So, haloperidol alone was discontinued. One week later, the hair loss had stopped and a month later alopecia had virtually disappeared. We suggest that alopecia areata is associated with haloperidol.

Administration, Oral↗
PubMed1993

Three cases of alopecia areata induced by zotepine.

One schizophrenic and two manic-depressive patients who after the administration of zotepine, a new antipsychotic and antimanic drug, developed alopecia areata, a kind of autoimmune disease, are reported. They recovered following the discontinuation or decrease in the dose of zotepine. These three cases of alopecia areata suggest that the antipsychotic drugs may induce autoimmune disease through their neuropsychological effect.

Adult↗
PubMed1993

[A case of old pulmonary tuberculosis with repeated hemoptysis which presented therapeutic difficulties].

A 74-year-old male who had been infected with pulmonary tuberculosis since 1938 underwent thoracoplasty in 1955. After the operation, no symptoms manifested until 1988 when he developed hemosputum and hemoptysis in association with a cold with fever. Although he was admitted to a hospital, the symptoms could not be controlled, so he was referred to our department. The lesion causing the hemorrhage was considered to be in the upper lobe of the left lung. However, it would have been difficult to preserve respiratory function in the case of left upper lobectomy, because he had already undergone thoracoplasty on the right side. Therefore, bronchial artery embolization (BAE) using Spongel was performed. Second embolization was performed because hemoptysis referred after one month. However, the hemoptysis recurred again, so that two branches of the left subclavian artery and the left internal thoracic artery were ligated. No hemoptysis and hemosputum occurred for a while, but 2 years and 9 months after the operation, the patient was admitted due to hemoptysis with fever and coughing. Since the bronchial artery was embolized twice with spongel and twice with platinum coil, the patient's course has been good for 5 months.

Aged↗
PubMed1992

[A rare case of mediastinal neuroblastoma with pectus excavatum in a 4-month-old boy--a surgical report].

Screening of neuroblastoma is commonly performed on 6-month-old infants; therefore, its discovery in children younger than that age is extremely rare. However, a 4-month-old boy with pectus excavatum was found to also have mediastinal neuroblastoma after close examination. This 7 kg child had no apparent symptoms, yet revealed an egg-sized shadow along the right atrium in the chest X-ray film, and along the right side of the vertebrae on CT. Due to the increase in the size of the tumor after two months of observation, we suspected malignant neurogenic tumor and performed a thoracotomy. With a right posterolateral thoracotomy we removed the dark-brown, elastic tumor measuring 6 x 4 x 3 cm and located along the right side of the vertebrae from III through VIII ribs. The origin was the thoracic sympathicus and the pathological diagnosis of the tumor was neuroblastoma with rosset formation. After conducting a post-operative chemotherapy (Jame's protocol), no evidence of recurrence was observed at 33 months after surgical treatment. We summarized the previously reported seven surgically treated cases of Stage I mediastinal neuroblastoma at less than 12 months of age. Among the 2500 pectus excavatum surgeries that have been held at our department, non has been found to have mediastinal neuroblastoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Kinetic analysis of dehydropeptidase-I and comparative in vitro and in vivo stabilities of PS-5 derivatives modified at the C-3 side chain.

With partially purified kidney dehydropeptidase-I (DHP-I) preparations, the hydrolysis kinetics of glycyldehydrophenylalanine (Gly-dPh) by DHP-I were found to be completely non-Michaelian, whereas those of PS-5 and imipenem were composed of at least two-phase reactions which were also observed using Bacillus cereus type II beta-lactamase. Thus the DHP-I stabilities of 34 PS-5 carbapenem derivatives which were synthesized by chemical modification at the C-3 side chain of PS-5 were examined in vitro using fresh mouse, dog and human DHP-I preparations, and are tentatively expressed in reference to the DHP-I stabilities of PS-5. The in vitro DHP-I stability of PS-5 was significantly improved by introduction of basic side chains and cysteines at C-3. More particularly, the D-cysteinyl side chain was more stable relative to DHP-I than the L-cysteinyl. In vivo, however, the degree of improvement of the DHP-I-stability by chemical modification at C-3 was not sufficient enough to establish therapeutically effective levels of serum concentrations and urinary recoveries of the carbapenem derivatives after parenteral administration.

Animals↗
PubMed1991

Anthracycline metabolites from Streptomyces violaceus A262. I. Isolation of antibiotic-blocked mutants from Streptomyces violaceus A262.

Five mutant (or variant) strains producing new anthracycline antibiotics were derived from Streptomyces violaceus A262 by mutagenesis treatment. Strain SE1-625 showed a limited production of three known beta-rhodomycinone diglycosides while the parent strain produced numerous unidentified beta-rhodomycinone glycosides. Strain SU2-730 was an antibiotic-blocked mutant which produced only epsilon-rhodomycinone glycosides (named epelmycins). Strains SC-7 and SE2-2385 were variants which produced alpha-citromycinone glycosides (named yellamycins) and beta-isorhodomycinone glycosides (named obelmycins), respectively. Strain SE2-2385-A1 produced alpha 2-rhodomycinone glycosides (named alldimycins). Glycosidation-less mutants which accumulated only aglycone were also obtained. Isolation of these mutants or variants and preliminary identification of their anthracycline products are described.

Anthracyclines↗
PubMed1991

Anthracycline metabolites from Streptomyces violaceus A262. II. New anthracycline epelmycins produced by a blocked mutant strain SU2-730.

New anthracycline antibiotics, identified as epsilon-rhodomycinone glycosides, were isolated from the culture broth of a blocked mutant of beta-rhodomycin-producing Streptomyces violaceus A262. They were designated as epelmycins A, B, C, D and E, and assayed for their in vitro cytotoxicities against murine leukemic L1210 cell culture and the antimicrobial activities in comparison with known anthracycline antibiotics.

Animals↗
PubMed1991

Anthracycline metabolites from Streptomyces violaceus A262. III. New anthracycline obelmycins produced by a variant strain SE2-2385.

New anthracycline antibiotics, designated as obelmycins A, D, E, F and G, were isolated from the culture broth of a variant strain of beta-rhodomycin-producing Streptomyces violaceus A262, identified as beta-isorhodomycinone glycosides and gamma-isorhodomycinone glycosides and assayed for their in vitro cytotoxicities against murine leukemic L1210 cell culture and the antimicrobial activities in comparison with some known anthracyclines.

Animals↗