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Biomedical subjects

R Nakamura

Publications and source records attributed to R Nakamura.

At least 433 records · Page 24Linked to original sources
PubMed1983

Effect of passive movements on reaction time of the rectus femoris in normal subjects and patients with paraparesis.

Electromyographic reaction times (EMG-RTs) of the right knee extension were examined in eight normal subjects and eight patients with paraparesis under three conditions; during passive knee flexion (PFLX), passive extension (PEXT) and no passive movements (STAT). EMG-RTs of the three conditions were not significantly different between the normal and the patient group. A two-way analysis of variance (condition x group) showed that the main effect of condition was significant, but that of group and the interaction were not. Both in the normal and the patient group the shortest EMG-RTs of all was obtained in PEXT, followed by that of STAT and PFLX. Effect of passive movements on EMG-RTs in the patients whose position sense of the knee and muscle strength of the knee extension were within normal range did not vary with the abnormality of tactile sense and/or myotatic reflexes. The results indicated that activities of the pyramidal tract neurons in carrying out a movement were directly influenced by kinesthetic information of the moving limb.

Adult↗
PubMed1983

Motor reaction time as a measure of rapid force generation of a muscle.

Motor reaction time (MT) of the vastus medialis, latency from the EMG onset to initiation of the actual movement of the lower leg, was examined for 19 normal subjects during rapid extension of the knee joint at various angles from 90 degrees to 0 degrees in the sitting posture. Muscular tension produced by maximal voluntary contraction (MVC) was measured at 80 degrees of the knee joint for 19 subjects. Also, EMG activities during period of MT were integrated at each angle of the knee for five subjects. MT correlated linearly with the integrated EMG, indicating that MT was a variable representing muscular force required for initiation of the movement. MT increased with extension of the knee and the increment was attributed to the increased effective load of the lower leg due to gravity in the range from 90 degrees to 30 degrees of knee flexion. Thus, MT could be defined solely by the external load against the movement in the mid-range of the joint angle. Moreover, at 80 degrees knee flexion MT did not relate to MVC. It is suggested that MT provides a useful means to evaluate a muscular function in rapid movement and is applicable to both normal and pathological situations.

Adult↗
PubMed1983

How to use bilateral motions in facilitation techniques.

Influence of contralateral finger motions on ipsilateral finger extension was analyzed in order to explore optimal condition of bilateral motions as a facilitation technique, measuring motor times (MTs) of finger extensor muscles in four conditions; homonymous or non-homonymous as for muscle coupling and simultaneous or successive as for timing of motion-initiation. Compared to unilateral motion, MTs shortened only in bilateral motion with preceding sustained contractions of the contralateral homonymous muscle.

Electromyography↗
PubMed1983

Purification and characterization of galactosephilic component present on the cell surfaces of Streptococcus sanguis ATCC 10557.

Previous studies have indicated that a galactosephilic component present on the bacterial cell surfaces of Streptococcus sanguis ATCC 10557 may be responsible for the salivary glycoprotein-mediated binding of the cells. The purpose of this study was to investigate the purification and characterization of galactosephilic cell surface component from S. sanguis ATCC 10557. A galactosephilic component involving fibrils on the cell surfaces was isolated by the techniques of freezing and thawing, and purified by an affinity chromatography on beta-D-galactose binding-Bio-Gel P-2 followed by gel filtrations on Bio-Gel P-150 and on Bio-Gel P-30. Both disk gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the purified product was homogeneous. The isoelectric point of the purified sample was 8.5 to 9.0. Treatment of the purified sample with pronase E reduced remarkably either the hemagglutinating activity or the precipitation reaction with proline-rich glycoprotein in human parotid saliva, suggesting that the active site may be present on the peptide moieties. When sugar specificity was examined by hemagglutination-inhibition test, D-galactose was the strongest inhibitor. The results of this study suggest that the galactosephilic component may be a bacterial lectin.

Cell Wall↗
PubMed1983

Premotor and motor reaction time as a function of force output.

The effects of variation in force output on fractionated reaction times (RTs) in elbow extension for 5 normal adults were examined. Force was manipulated by instructing the subject to respond with much or little force, and force output was measured by an accelerometer. Premotor RT increased with increased force output, indicating that organization of force for movement could affect not only the movement speed but the timing of its initiation. Motor RT became longer at manipulated force production than the control response, suggesting that motor RT was also influenced by the central processing of movement organization. The early electromyographic activities of the triceps brachii muscle were examined and discussed in relation to the production of force for initiation of movement.

Adult↗
PubMed1983

Chemical forms of radioactive iodine in seawater and its effects upon marine organisms.

Chemical forms of radioactive iodine and its effects upon marine organisms were studied by the tracer experiments. Seaweeds or fish were held in the aquarium in which the 125I tracer in either iodide or iodate form was inoculated. Iodide form of 125I was taken by Dorome (Chasmichthys gulosus) with the concentration factor of about 10 and excreted with the biological half-life of 15 days, while iodate form of 125I was not taken up appreciably and the concentration factor did not greatly exceed unity. Uptake and loss of 125I were studied as well for 3 species of seaweeds, Hijiki(Hizikia fusiforme), Nejimoku (Sargassum sagamianum) and Tsunomata (Chondrus ocellatus). Iodate form of 125I was accumulated less than iodide form by these seaweeds but the concentration factor of iodate by these seaweeds was very high compared to those by fish.

Animals↗
PubMed1983

[Clinical study on preoperative chemotherapy of primary breast cancer. 2--A comparative study of CPA + FT-207 (5-FUDS) and CPA + FT-207 (5-FUDS) + MMC].

In 41 cases of primary breast cancer preoperative treatment was performed using 2 methods consisting CPA + FT-207 (5-FUDS) (for Group I) and CPA + FT-207 (5-FUDS) + MMC (for Group II) to determine clinical and histological efficacies. A daily dose of each anticancer drug was: CPA 50-200 mg, FT-207 200-600 mg, and 5-FUDS 200 mg orally, and MMC 4-20 mg intravenously. The mean total doses were 1.8 g, 6.3 g, 3.4 g and 26.3 mg, respectively. Reduction in tumor size was obtained in 11 cases (37.9%) in Group I and 6 cases (50.0%) in Group II. According to Ohboshi's criteria, histological efficacy as defined over Grade II a was seen in 5 cases (17.2%) in Group I and 6 cases (50.0%) in Group II, while the efficacy classified as Grade III was not seen in any of the cases. Although the clinical effect was not always consistent with the histological effect, there was a tendency of agreement between them in Group II. As to the dosages of anticancer drugs, more effective cases were seen when dosages of more than 25 mg/kg of CPA, 80 mg/kg of FT-207 (5-FUDS) or 0.5 mg/kg of MMC were used. Reduction in tumor size began to appear at 2 to 3 weeks after the initiation of treatment.

Adult↗
PubMed1982

Immunochemical studies on thermal denaturation of ovomucoid.

The thermal denaturation of ovomucoid was investigated by immunochemical methods, namely immunoprecipitation analyses and antibody-Sepharose 4B column chromatography. In the immunoprecipitation analyses, heated ovomucoid (90 degrees C, 90 min, pH 7.2) required about twice the antigen addition of the native protein to approach maximal precipitation with specific antibody, and the maximal immunoprecipitation was decreased to 80% of that by native ovomucoid. However, heated protein inhibited the binding of antibody with native ovomucoid, and 100% inhibition was attained at about 4-times the antigen addition necessary for the native protein. Heated ovomucoid (100 degrees C, 120 min) showed little immunoprecipitation and inhibition. To ovomucoid antigenicity was diminished more slowly than the trypsin inhibitory activity by heating, e.g., heated ovomucoid (90 degrees C, 120 min) retained more than 30% of the antigenicity but little trypsin inhibitory activity. By passing through the immunoaffinity column, heated ovomucoid (90 degrees C, 90 min) was separated into two fractions, either with (fraction II) or without (fraction I) antigenicity. Fraction II contained smaller fractions of ordered secondary structure than native ovomucoid, and trypsin inhibitory activity of fraction II was only 24% of the native one. These results indicated that thermally denatured ovomucoid was heterogeneous regarding the conformational damage caused by heating, and the structure around some antigenic sites in an ovomucoid molecule was retained even after the backbone conformation was partially destroyed and trypsin inhibitory activity was lost.

Animals↗
PubMed1982

Juvenile polyposis coli. A case report.

We report a case of juvenile polyposis coli in a 13 year old girl who initially complained of rectal bleeding and prolapse of polyps. Tube feeding with an elemental or a low residue diet and total parenteral nutrition were prescribed to treat the hypoproteinemia and anemia. A modified Soave's operation was successfully performed. The polyps appeared in several different stages of development. A single dilated gland of the colonic mucosa, which was not grossly visible, was presumed to be the site of the initial lesion which developed into a typical juvenile polyp. Adenomatous tubules were found in some juvenile polyps. In this case of immunologic deficiency, it is not clear whether such was a primary or secondary phenomenon.

Adolescent↗
PubMed1982

Finger tapping test as a means to differentiate olivo-ponto-cerebellar atrophy among spinocerebellar degenerations.

A finger tapping test in which the subject was requested to respond synchronously to the periodic sound signal was performed on 10 patients with OPCA, 10 other SCD and five suspected OPCA. The results indicated that the response of the patients with OPCA was specific among SCD. The response did not more synchronize to the signal above 2.5 Hz and a random mixture of two types of the response appeared with frequencies lower and higher than the signal. These delayed and hastened responses represented the characteristic response feature for the patients with SCD except OPCA and those with Parkinson's disease, respectively. Two types of the response were related to cerebellar lesions and to nigrostriatal lesions. The finger tapping test thus offers a useful means to differentiate OPCA among SCD.

Adult↗