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Biomedical subjects

M Nakata

Publications and source records attributed to M Nakata.

At least 271 records · Page 15Linked to original sources
PubMed1989

[An odontological study on Down's syndrome. Part 3: Dental caries of the deciduous teeth].

The dental caries experience of a sample of 97 children with Down's syndrome who had deciduous dentition was contrasted with that of 57 non affected healthy children. The children with Down's syndrome had a caries experience less than one-third that of the control. However between the two groups, there was no difference in the relative caries pattern between occlusal, surficial and proximal tooth caries. We investigated the relationship between two factors, the delayed eruption pattern and any other environmental factors (tooth bursting, sugar control, nocturnal bottle feeding and caries activity) and the low dental caries experience in children with Down's syndrome. For the eruption factor of the deciduous teeth, we calculated the post eruptive age and excepted the delayed eruption pattern of children with Down's syndrome. It was apparent that two factors did not influence the low dental caries experience of the deciduous teeth in children with Down's syndrome.

Child↗
PubMed1989

[Three cases of endobronchial hamartoma].

We reported three cases of endobronchial hamartoma. There were some difficulties in diagnosis of the disease by bronchoscopic examination, because the tumors were covered with normal bronchial epithelium. But X ray film and CT film contributed to the diagnosis when calcification of intra-bronchial tumor was observed. Three different modes of operation were performed as extirpation of tumor by wedge resection of upper lobe bronchus, sleeve resection of left S6 segmental bronchus, and right middle lobectomy.

Adult↗
PubMed1989

Transfer of innovation for advancement in dentistry: a case study on pit and fissure sealants' use in Japan.

The implementation of scientific innovations is most important in advancing both dental care systems and dental science. However, scientific knowledge in dentistry is not always well implemented. In this paper the phases of development, diffusion, adoption and utilization of sealants are examined as one example of the way in which a relatively new innovation still needs more effort to ensure its wider use. Discussions with a dental manufacturer on the development of sealant materials and an investigation into the adoption of sealants in the national health insurance system of Japan were undertaken. Questionnaires regarding the education on sealants offered in dental schools and dental hygienist schools, and questionnaires to dental practitioners concerning their use of sealants, were used and analysed. The analysis of the various factors showed that the transfer of knowledge through the educational system is the most significant step in the uptake of innovations. Legality, insurance coverage and patient acceptance are significantly associated with the phase of adoption. A model of transfer pathways for new dental innovations is proposed.

Attitude of Health Personnel↗
PubMed1989

[Angiographic findings of gallbladder cancer].

The patients with gallbladder cancer often accompany with chronic cholecystitis. This fact leads angiographic diagnosis difficult. So the angiographic findings of the chronic cholecystitis are first analyzed precisely and subtracting the angiographic findings of the gallbladder cancer from these gives us the pure (true) angiographic findings of the gallbladder cancer. Characteristic angiographic findings of the gallbladder cancer only are stretched cystic artery encasement (27/37 cases) and short straight tumor vessels "bristly vessel" (36/37 cases).

Aged↗
PubMed1989

[Treatment of a patient with mediastinal germinoma and with rare anomaly of congenital subclavian steal phenomenon].

A 40-year-old male with anterior mediastinal germinoma, who had developed cardiac tamponade, was treated with two courses of chemotherapy consisting of CDDP, Vindesine, Pepleomycin. After marked decrease of tumor size was obtained, complete surgical resection was performed. Following the operation, he received one more course of chemotherapy and 40 Gray of radiation therapy. He is now in good health 7 months after operation without showing any sign of recurrence. This case was also associated with right aortic arch and congenital subclavian steal phenomenon. These rare anomalies were reported only some 40 cases in the literature and the case with those rare anomalies and the mediastinal tumor was not seen in the literature.

Adult↗
PubMed1988

Inhibition by the antilipogenic antibiotic cerulenin of thrombin-induced activation of human platelets.

Upon incubation with an antibiotic cerulenin, human platelets lost their abilities to aggregate and to release serotonin or ATP in response to various stimuli such as thrombin, ADP, collagen and platelet activating factor. The loss of activities was dependent on both incubation time and cerulenin concentrations. As judged by 14C-serotonin release, concentrations of cerulenin required for the half-maximal inhibition of thrombin-induced activation were 5-10 and 70 micrograms/ml in the incubation for 120 min at 37 degrees C for washed platelets and those in platelet rich plasma, respectively. The cerulenin treatment also resulted in a significant inhibition of 14C-acetate incorporation into the lipid fraction of platelets, suggesting that de novo synthesis of fatty acids was inhibited by the treatment. No release of lactate dehydrogenase activity nor morphological changes in platelet structure was detected upon cerulenin treatment. When effects of cerulenin on intracellular Ca2+ concentration were examined, mobilization of intracellular Ca2+ by thrombin was significantly depressed in the cerulenin-treated platelets as judged by Fura2, Quin2 or chlortetracycline fluorescence. Since the influx of external Ca2+ is not essential to the thrombin-induced platelet activation (Rink, T. J. et al. FEBS Lett. 148 21-26, 1982), the results suggest that cerulenin-treatments affect the platelet function through the inhibition of intracellular Ca2+ mobilization.

Adenosine Triphosphate↗
PubMed1988

[Fatigue and low-back pain of freight-container tractor drivers. Correlation with ergonomic factors].

An ergonomic checklist was prepared to examine safety and comfort of freight-container tractors. With this checklist, 533 tractor drivers were asked to evaluate the tractors to which they were exclusively assigned. In order to check the objectivity and the validity of the results, the correlation between the evaluation of the items on the checklist and the corresponding dimensions on 10 tractors was studied. Also, a multivariate analysis based on quantification theory was done to examine the correlation between the ergonomic items on the checklist and the drivers' low-back pain or fatigue symptoms of the upper and lower extremities. The main results were as follows: 1) A high correlation was observed between the evaluation of items on the checklist and the corresponding dimensions of the tractors. 2) Many items on the checklist received a poor evaluations, indicating that there are many ergonomic problems with freight-container tractors. 3) The analysis by the quantification theory showed high correlation ratios between the items in the checklist and the drivers' fatigue symptoms of the upper and lower extremities. These correlation ratios were: arm fatigue when holding the steering wheel (0.51), arm fatigue in operating the gearshift lever (0.65), arm fatigue from opening and closing the windows (0.46), leg fatigue from operating the pedals (0.58), and low-back pain during the last two months (0.31). These showed that more than 50% of the fatigue symptoms could be explained by the ergonomic aspects of the tractors. 4) The rate of dissatisfaction with the current tractors was 82.9%. According to the analysis by the quantification theory, the correlation ratio between the items in the checklist and the rate of dissatisfaction for the current tractors was 0.66. 5) The foregoing results indicate that ergonomic improvement of the freight-container tractors is a matter of urgency. This should reduce the drivers' fatigue and elevate the rate of satisfaction with the tractors. 6) However, for the prevention of the drivers' low-back pain and fatigue symptoms, improvement of the ergonomic conditions of the tractors and the drivers' working conditions must be undertaken at the same time.

Adult↗
PubMed1988

Cell surface analysis of purified protein derivative-induced cytotoxic cells in tuberculous pleurisy.

High NK cell activity was observed in tuberculous pleural effusions from which mycobacterium tuberculosis was cultured. Further we observed that cytotoxicity against K562 was augmented by purified protein derivative (PPD). We have now performed the surface analysis of the cells in PPD-induced cytotoxicity using various monoclonal antibodies (mAb) (anti-Leu 1, anti-Leu 7, anti-Leu 11, anti-HLA-DR). Leu 11+ cells have essential cytotoxicity in PPD-induced cytotoxicity, but neither Leu 1+ nor Leu 7+ cells have such cytotoxicity. The PPD-induced cytotoxicity eliminated by the treatment with anti-HLA-DR mAb plus complement was reconstituted by adding either interferon (IFN)-alpha or beta. From these data it was suggested that Leu 11+ cells could be activated through either IFN-alpha or beta derived from HLA-DR+ cells in tuberculous pleural effusion.

Adult↗
PubMed1988

Purified protein derivative induced cytotoxicity in carcinomatous and tuberculous pleurisy.

We have found that natural killer (NK) cells were very active in pleural effusions containing Mycobacterium tuberculosis. Cytotoxicity against K562 and Raji was augmented when the mononuclear cells were cocultured for 18 hr with purified protein derivative (PPD) derived from M. tuberculosis culture supernatants. In pleural effusions of cancer patients, PPD-activated mononuclear cells were less cytotoxic than their counterparts in peripheral blood. However, in the same patients, interferon and interleukin-2 production was greater in pleural effusions than in peripheral blood. On the other hand, in tuberculosis patients there was no significant difference in cytotoxicity between peripheral blood and pleural effusion mononuclear cells, but the production of interferon and interleukin-2 was higher in pleural effusions than in peripheral blood. Neither group of patients consistently demonstrated a correlation between production of interferon or interleukin-2 in peripheral blood and cytotoxicity. Both PPD-induced cytotoxicity and the production of interferon and interleukin-2 were lower in mononuclear cells of carcinomatous than tuberculous pleural effusion. These results indicate that peripheral blood and pleural effusion mononuclear cells differ in cytotoxicity as well as in interferon and interleukin-2 production. Further, these activities also differ in tuberculous and carcinomatous pleural effusions.

Adult↗
PubMed1988

Genetic and environmental factors in the longitudinal growth of rats: I. Body weight and overall craniofacial size.

By means of roentgenographic cephalometry and quantitative genetic analysis, the relative contribution of the genetic and environmental components to total variance of body weight and overall craniofacial size was shown to vary with age. The genetic component of variance significantly increased until 80 days of age. Inversely, the maternal component of variance showed a high value during the early stage of postnatal growth and gradually decreased thereafter to a very small amount by day 80. Thus it appeared that the genetic effect became larger with age of the rat and the maternal effects diminished. The environmental component of variance did not change much over the course of the experiment. We thus conclude that genetic effect contributed the change of ontogenetic variation of craniofacial complex through all experimental periods and that maternal effect contributed to it at early growth stage of the craniofacial complex.

Aging↗
PubMed1988

Genetic and environmental factors in the longitudinal growth of rats: II. Ventrodorsal craniofacial size.

By means of roentgenographic cephalometry and quantitative genetic analysis, the relative contribution of the genetic and environmental components to the ontogenic change of the ventrodorsal view of the craniofacial complex was shown to vary with age. The genetic component of variance significantly increased until the 80th day. Inversely, the maternal component of variance showed a large value during the early stage of postnatal growth and gradually decreased thereafter to a very small amount by the 80th day. In general, it appeared that the genetic effect became larger with the age of the rat and the maternal effects tended to diminish. The environmental component of variance did not change much over the course of the experiment. We thus concluded that the genetic effect contributed to the change of the ontogenic variation of the craniofacial complex through all experimental periods and the maternal effect contributed to the change at the early growth stage of the craniofacial complex.

Aging↗
PubMed1988

Genetic and environmental factors in the longitudinal growth of rats: III. Craniofacial shape change.

This investigation expresses the similarity of the craniofacial shape of rats in terms of a single parameter and determines to what extent the shape variation of the craniofacial complex is genetically determined. To quantify the similarity of the craniofacial shape between any two individuals, diagrams plotted from their lateral cephalograms are so oriented that the distance from the points on the one to the corresponding points on the other is minimized. The data consist of measurements from within-strain, between-strain, maternal half-sibs and paternal half-sibs groups. The average dissimilarity is computed in each group and compared. The results indicate that this method can be used to estimate the similarity of the craniofacial shape. The dissimilarity of within-strain pairs shows the smallest Dh value, whereas between-strain pairs have the largest Dh value. Those of maternal and paternal half-sib pairs show the intermediate Dh value. The value of dissimilarity for these four pairs tends to decrease gradually with age and a considerable genetic effect acts on the change of the craniofacial shape during growth, while the maternal effect does not act significantly on the change of the craniofacial shape during growth.

Aging↗
PubMed1988

Dental survey in Nigeria. Part 4. Prevalence and severity of periodontal diseases.

Six hundred and seventy-three school children from the age of 3 to 20 living in the urban and the rural areas of Nigeria were examined by the Joint Dental Epidemiological Survey in 1986. The survey was funded by the Grant-in-Aid from the Japanese Ministry of Education, Science and Culture, and was conducted by both the Japanese survey team and the staff from the University of Ife, Ile-Ife, Nigeria. The periodontal state of the children was evaluated according to the Community Periodontal Index for Treatment Needs (CPITN) by WHO (1). The prevalence of periodontal diseases was found to be 84.2% within the sample with a high occurrence of gingivitis and heavy deposits of calculus. However, there was little evidence of damage to the periodontal tissues. This can be attributed to the nature of their diet. The results suggested that there would be an increasing need for well-planned and organized public educational programs for the Nigerian children to promote better oral hygiene coupled with parental involvement in the prevention at home.

Adolescent↗
PubMed1988

[Clinical study on the effect of adjuvant immunochemotherapy using OK-432 and 5-FU in pharyngeal and laryngeal cancers].

A randomized controlled trial was carried out on 38 pharyngeal and 59 laryngeal previously untreated cancers to evaluate the effects of adjuvant immunochemotherapy using 5-FU with and without OK-432. After each fundamental therapy, 5-FU was given orally at a dose of 200-300 mg/day for more than a year. OK-432 was intracutaneously administered at a dose of 5KE once a week for more than a year. Three-year survival rates and disease-free intervals were estimated for the two groups. In cases of pharyngeal cancer, the 3-year survival rate was 58% in both groups and the disease-free interval rates for up to 3 years after the fundamental therapy was 49% in the OK-432 + 5-FU group and 52% in the 5-FU group. These results showed no statistically significant difference. In laryngeal cancers, the 3-year survival rate was 96% in the OK-432 + 5-FU group and 82% in the 5-FU group. These results also showed no statistically significant difference. The disease-free interval rates were 87% in the OK-432 + 5-FU group and 64% in the 5-FU group, revealing a statistically significant difference (p less than 0.1). This suggests that OK-432 is more effective in producing a higher survival rate in cases of laryngeal cancer.

Administration, Oral↗
PubMed1987

Internalization of radioiodinated erythropoietin and the ligand-induced modulation of its receptor in murine erythroleukemia cells.

We have studied the internalization of 125I-erythropoietin (Epo) and regulation of Epo receptors by the ligand in a murine erythroleukemia cell clone, TSA8. To determine internalization, a high-salt acid wash was performed. Internalization of 125I-Epo was found in TSA8 cells as well as in fetal mouse liver cells (FMLC), although the percentage of internalized radioactivity reached 40% after incubation at 37 degrees C for 150 min and was lower than that in FMLC. Exposure of TSA8 cells to unlabeled Epo resulted in a rapid, time-dependent reduction in 125I-Epo binding activity. The net loss of the activity was related to the ambient Epo concentration and 5 X 10(-8)M Epo induced approximately 80% loss of total binding capacity. Scatchard analysis of the binding data revealed that the high-affinity receptor number was decreased but the affinity was increased in the Epo-treated cells. In low-affinity receptors, however, the receptor affinity was decreased and the receptor number was not changed much by preincubation with Epo. These results suggest that the decrease in 125I-Epo binding activity after preincubation with unlabeled Epo is mainly accounted for by a decrease in the number of high-affinity receptors, and the high-affinity receptors play an important role in the biological response to Epo.

Animals↗
PubMed1987

Immunofluorescence localization of type I and type III collagen and fibronectin in mouse dental tissues in late development and during molar eruption.

Affinity-purified antibodies produced intense staining for type I collagen in alveolar bone matrix and predentine, and moderate staining in the dentine matrix, lamina propria, connective tissue invaginating into papillary layer of the enamel organ, dental sac and periodontal ligament. No staining occurred in oral epithelium, stellate reticulum, stratum intermedium, ameloblasts and odontoblasts. Fibronectin was distributed similarly except at the interface between the epithelial diaphragm and pre-odontoblasts where type I collagen was absent but fibronectin was present. In contrast, type III collagen showed strong staining in the periodontal ligament and lamina propria but no staining in bone matrix, predentine, dentine and at the interface between the epithelial diaphragm and pre-odontoblasts. The staining pattern for type III collagen was similar to that of type I and fibronectin in other tissues including endosteal reticular tissue, the connective tissue invaginating into papillary layer and the extracellular matrix of the pulp.

Alveolar Process↗