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Biomedical subjects

Y Miki

Publications and source records attributed to Y Miki.

At least 217 records · Page 12Linked to original sources
PubMed1988

[Microbiological evaluation of topical application of the controlled release strips containing ofloxacin (PT-01) in the human periodontal pocket].

The recognition that destructive periodontal diseases may be caused by specific microorganisms has led to an increased interest and usage of antimicrobial agents in periodontal therapy. In this study, the effect of topical application of ofloxacin (OFLX), a synthetic antibiotic, was microbiologically evaluated. The new developed controlled release strips containing OFLX (PT-01), in which there were structurally immediate- and sustained-releasing portions, were applied to the periodontal pockets of 27 adult subjects with periodontitis. Three different sites with a deep probing pocket depth (greater than or equal to 5 mm) were randomly selected in each patient, and were divided into three groups, i.e., PT-01 applied site (T), placebo-applied site (P) and control site (C). Periodontal treatments consisted of oral hygiene instruction and supragingival scaling on day 0 and 7, and subgingival scaling and root planing on day 14. PT-01 was weekly applied on day 0 to 35, and the subgingival plaque samples from each site were collected on day 0, 14, 21 and 42. The dynamics of subgingival microflora was investigated by dark field microscopy for determination of the %s of spirochetes, motile rods and coccoid cells, and anaerobic and aerobic cultivations for the determinations of the total number of subgingival bacteria, black-pigmented Bacteroides (BPB), Fusobacterium species and Actinobacillus actinomycetemcomitans. The results showed that the significant reduction of %s of spirochetes and motile rods and significant increase of % coccoid cells were found in only PT-01 applied sites during first 14 days. In this period, the total number of cultivable bacteria, BPB and Fusobacterium species were also significantly reduced in T sites. While, after subgingival scaling and root planing were performed, significant changes in the proportions and numbers of the subgingival microflora were found in all sites. Especially, PT-01 applied site showed significant improvement in the %s of spirochetes and motile rods as well as the total number of the bacteria. Moreover, the further microbiological determinations of the each isolate revealed that no detectable amounts of A. actinomycetemcomitans could be found from any samples in this study. These results suggested that weekly application of PT-01 in the periodontal pocket could have significant effects on the qualitative and quantitative improvements in the subgingival microflora. It was also suggested that the application of PT-01 might have ameliorating effect as adjuncts of mechanical subgingival plaque control in the periodontal treatment.

Adult↗
PubMed1988

Oxidative metabolism of propylthiouracil by peroxidases from rat bone marrow.

1. Propylthiouracil (PTU) was degraded by myeloperoxidase (MPO) or eosinophil peroxidase (EPO), purified from rat bone marrow, in the presence of H2O2 and Cl-. In the absence of either H2O2 or Cl-, MPO and EPO do not degrade PTU. Optimum concentrations of KCl for MPO and EPO were 50 and 250 mM, respectively. 2. The characteristics of PTU degradation by MPO-H2O2-Cl- were similar to those of the chlorinating activity of the peroxidase. 3. Hypochlorous acid as well as MPO-H2O2-Cl- also degraded PTU. Metabolites of PTU degradation by MPO-H2O2-Cl-, which were separated by C18 reversed phase h.p.l.c., were the same as those produced by hypochlorous acid. 4. Of the metabolites of PTU formed by MPO-H2O2-Cl-, one was identified as PTU sulphonic acid (6-propyl-4-hydroxypyrimidine-2-sulphonate) and another seemed to be propyluracil.

Animals↗
PubMed1988

[Recent trends in studies on carcinogenesis in familial adenomatous polyposis].

Familial adenomatous polyposis is rare disease, but it is considered as the most important clinical model for studying cancer control and carcinogenesis in general, by its extremely high risk for colorectal cancer as well as for malignancies of diverse organs which is transmitted by autosomal dominant mode. According to Knudson, the mutation for a dominantly inherited cancer susceptibility may be the first step in a recessive change in the tumor cell and same gene may be involved in both familial and non-familial cases of the tumor. The recent studies by Bodmer et al and by Solomon et al which reported on FAP locus in chromosome 5 and on loss of heterozygosity of this locus in the colorectal cancer have made an important break through in proving the Knudson's hypothesis. The epidemiological, clinical and pathological observations on FAP including our studies has been discussed in the view of these recent development of molecular biology.

Adenoma↗
PubMed1988

Plasma atrial natriuretic peptide in patients with congenital heart diseases.

The plasma level of human alpha-atrial natriuretic peptide was measured in healthy children and patients, 1 month to 15 years of age, with congenital heart diseases. Significant increases were found in patients with a ventricular septal defect, tricuspid valve atresia, patent ductus arteriosus, and atrial septal defect but not in those with pulmonary valve stenosis or tetralogy of Fallot. The levels were significantly higher in children with ventricular septal defects (221 +/- 123 pg/mL) or patent ductus arteriosus (124 +/- 38 pg/mL) than in those with atrial septal defects (65 +/- 42 pg/mL) (P less than .01). The increased levels appeared to be correlated with enlargement of the left atrium (r = .85, P less than .01) but not with the right atrial size or the mean right atrial pressure. They were higher in younger than in older healthy infants, but this age difference did not affect the results. These findings indicate that human alpha-atrial natriuretic peptide is released into the circulation in response to chronic atrial expansion in patients with congenital heart disease and may have an important role in volume homeostasis.

Adolescent↗
PubMed1987

Light and electron microscopic studies of a case with simultaneous Mondini and Michel deformities of the inner ears.

We performed light and electron microscopic studies on the temporal bones of a patient with genetic aplastic deafness, in which the right ear had a Mondini-type defect and the left ear a Michel-type anomaly. The round window of each ear was absent. The stapedial foot plate of the right ear was depressed at its central part and was covered by thin membrane. The course of the internal auditory meatus of the left ear was deviated ventrally. There was total aplasia of the cochlea in the left ear, while that of the right ear showed only three-quarters of a turn. In this ear, three sites of spherical bulging were found and were believed to represent outer hair cells. Other structures of the normal cochlear duct were not present. The modiolus of the left ear was round and dome-shaped, contained sparse nerve fibers and a primitive spiral ganglion. The saccule, utricle and semicircular canals of each ear were missing, so that a common cavity of the vestibular system was present. Several otoliths could be seen under the surface of the membrane covering the common cavity. No sensory cells or their related tissues could be found in either ear.

Aged↗
PubMed1987

Enteric gamma-aminobutyric acid-containing neurons and the relevance to motility of the cat colon.

gamma-Aminobutyric acid (GABA)-containing neurons were identified and the functional relevance in the motility of the colon was studied. Autoradiography of the cat colon treated with [3H]GABA demonstrated scattered neurons in the myenteric plexus selectively labeled with [3H]GABA. Electrical transmural stimulation of the isolated cat colon led to an increase in the Ca2+-dependent, tetrodotoxin-sensitive release of endogenous GABA. gamma-Aminobutyric acid increased the amplitude of rhythmic contractions of the circular muscle of the colon and also the release of acetylcholine, which was Ca2+-dependent and tetrodotoxin-sensitive. Scopolamine inhibited the GABA-evoked rhythmic contractions, without effect on the evoked release of acetylcholine. Bicuculline and furosemide reduced the amplitude of spontaneous rhythmic contractions and the tone, which was reversed by GABA. These results suggest that GABA-containing neurons are involved in the control of motility of the cat colon, due to the stimulation of cholinergic neurons.

Acetylcholine↗
PubMed1987

Bloom's syndrome with porokeratosis of Mibelli and multiple cancers of the skin, lung and colon.

A 38-year-old Japanese male with Bloom's syndrome (BS) and porokeratosis of Mibelli (PM) developed multiple carcinomas of the skin and lung. There were multiple, spontaneous chromosomal aberrations and frequent sister chromatid exchanges (SCE). Cutaneous delayed-type hypersensitivity reactions were defective and serum IgM was decreased. The lung cancer was treated with radiation, which was effective but caused a severe pulmonary atelectasis and esophageal stricture. The patient expired one-and-a-half years later because of pneumonia. Autopsy disclosed an adenocarcinoma of the colon. The concurrent PM was considered responsible for the occurrence of multiple skin cancers.

Adenocarcinoma↗
PubMed1987

Mitogenic activity of cementum components to gingival fibroblasts.

Cementum forms the interface between root dentin and periodontal ligament through which periodontal connective tissue is attached to root surfaces. We have examined how cementum components influence the biological activities of gingival fibroblasts. Cementum was harvested from freshly extracted human teeth and extracted sequentially with 0.5 mol/L acetic acid, 4 mol/L guanidine-0.5 mol/L EDTA, and bacterial collagenase. The extracts were concentrated and analyzed for mitogenic activity to human gingival fibroblasts. DNA synthesis was assayed by measurement of [3H]thymidine incorporation by quiescent fibroblasts activated to divide, and cell growth was determined by the counting of cells over a 10-day period. Results showed that extracts of cementum stimulated quiescent gingival fibroblasts to synthesize DNA and grow. The stimulation was dose-dependent, and most of the stimulatory activity was extracted by acid. Addition of small quantities of serum potentiated the mitogenic activity to levels greater than those of control cultures containing 10% fetal calf serum. The mitogenic activity was heat-stable, but it was destroyed by trypsin. Neither platelet-derived growth factor (PDGF) nor epidermal growth factor (EGF) was detectable in the cementum extract, and extracts of human dentin and skin contained very little mitogenic activity. We conclude that cementum contains substances capable of regulating the growth of gingival fibroblasts, and that these substances may play an important role in gingival connective tissue formation and regeneration.

Cell Division↗
PubMed1987

[Radiation therapy of metastatic sites in hepatoma].

Ten patients with hepatoma who had received radiotherapy for their metastatic sites have been reviewed. In 13 lesions of bone metastasis in 7 patients complete pain relief from 5 lesions (38%) was achieved, while partial relief (54%) was obtained in other lesions. Of 3 patients with a brain metastasis, one attained complete symptomatic improvement with a 65% tumor reduction, and one of the remaining two gained a symptomatic palliation. In a patient with two pulmonary metastases, intraarterial chemotherapy showed a more remarkable effect when treatment was combined with radiotherapy than intraarterial chemotherapy alone. It may be concluded that radiation therapy is effected modality for palliating metastatic lesions of hepatoma.

Aged↗