Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 271 records · Page 15Linked to original sources

PubMed1995

In vitro activity of tetracyclines, macrolides, quinolones, clindamycin and metronidazole against periodontopathic bacteria.

We re-evaluated several antibiotics including newer ones, for their in vitro killing activity, as well as their inhibitory activity, against clinical isolates of periodontopathic bacteria. Tetracyclines were active against Porphyromonas gingivalis, and were highly active against Prevotella intermedia, but demonstrated only a low killing activity against Actinobacillus actinomycetemcomitans. Rokitamycin, a new macrolide, and clindamycin were highly active against P. gingivalis and P. intermedia, but showed very weak killing activity against A. actinomycetemcomitans. Quinolones demonstrated excellent bactericidal activity against A. actinomycetemcomitans, and good inhibitory and bactericidal activity against P. gingivalis and P. intermedia. Metronidazole had an activity almost equivalent to quinolones against P. gingivalis and P. intermedia; but it was the least active against A. actinomycetemcomitans.

Aggregatibacter actinomycetemcomitans↗

PubMed1995

Identification of endo-beta-N-acetylglucosaminidase and N-acetylmuramyl-L-alanine amidase as cluster-dispersing enzymes in Staphylococcus aureus.

Two proteins which are capable of dispersing cell clusters of Staphylococcus aureus have been purified from a S. aureus FDA209P culture supernatant. Both of them were found to have bacteriolytic activity. From the elution profile of column chromatography and Western blot (immunoblot) analysis, one of them was identified as a 51-kDa endo-beta-N-acetylglucosaminidase (GL). The other was a 62-kDa protein on the basis of sodium dodecyl sulfate gel electrophoresis. Analysis of the peptidoglycan fragments following treatment with the 62-kDa protein indicated that this protein is an N-acetylmuramyl-L-alanine amidase (AM). In vitro studies of cluster dispersion activities using S. aureus mutant strains Lyt66 or S. aureus Wood46 grown as clusters demonstrated that these two enzymes act synergistically to disperse clusters into single cells. Antiserum against the 51-kDa GL cross-reacted with the 62-kDa AM, and S. aureus FDA209P grown in the presence of anti-51-kDa-GL immunoglobulin G induced giant clusters. Clusters induced by anti-51-kDa GL and by Cibacron blue F3G-A were dispersed by coincubation with the 51-kDa GL and the 62-kDa AM. Western blot analysis demonstrated that the 51-kDa GL and the 62-kDa AM were missing in culture supernatants of S. aureus Lyt66, Wood46, and RUSAL2 (Tn551 autolysin-defective mutant), which grow in clusters. These results strongly suggest that the 51-kDa GL and 62-kDa AM are involved in cell separation of daughter cells after cell division.

Acetylglucosaminidase↗

PubMed1995

Common mutations in the low-density-lipoprotein-receptor gene causing familial hypercholesterolemia in the Japanese population.

Familial hypercholesterolemia (FH) is a common genetic disorder caused by mutations of the LDL-receptor gene. In the present study, we investigated four Japanese FH homozygotes and identified five point mutations: a splice site mutation in intron 12 (the 1845 + 2 T-->C mutation), a missense mutation in exon 7 (the C317S mutation), a nonsense mutation in exon 17 (the K790X mutation), a missense mutation in exon 14 (the P664L mutation), and a missense mutation in exon 4 (the E119K mutation). We developed simple methods for detecting these mutations. When we examined the presence of these mutations in 24 unrelated FH homozygotes, the 1845 + 2 T-->C mutation was found in 7 of them, and the other four mutations were unique for each proband. We also screened 120 unrelated FH heterozygotes for these mutations and found that the frequencies of the 1845 + 2 T-->C, C317S, K790X, P664L, and E119K mutations were 13.3% (16/120), 6.7% (8/120), 6.7% (8/120), 3.3% (4/120), and 1.7% (2/120), respectively. These mutations were found in more than 30% of unrelated Japanese FH patients. By using the detection methods developed in this study, the diagnosis of more than 30% of the genetic bases of Japanese FH heterozygotes is expected.

Adult↗

PubMed1995

Nylon monofilament for intraluminal middle cerebral artery occlusion in rats.

BACKGROUND AND PURPOSE: In rat middle cerebral artery (MCA) occlusion models with an intraluminal nylon monofilament, lesion volume and its reproducibility vary among laboratories. These variations may be caused by differences in the properties of nylon monofilaments. We performed the present study to compare the effects of two different types of 4-0 nylon monofilament on neurological and morphological outcomes in this model. METHODS: We randomly and blindly used two types of 4-0 nylon monofilament (Ethilon, n = 15, and Nitcho, n = 15) to permanently occlude the ostium of the right MCA intraluminally in rats. Neurological outcome and lesion size were compared 24 hours after MCA occlusion between the two groups. The diameter, tensile strength, and extensibility of each filament were measured. RESULTS: Neurological outcome was not different between the groups. The mortality within 24 hours was 13% (2/15) in the Ethilon group and 0% in the Nitcho group. Total lesion volume in the former was 295.9 +/- 97.2 mm3 (mean +/- SD), significantly larger and more reproducible than that in the latter (190.3 +/- 144.7 mm3, P = .026). The Ethilon filament had a significantly larger diameter (Ethilon, 0.193 +/- 0.001 mm; Nitcho, 0.180 +/- 0.001 mm; P < .0001), poorer tensile strength, and better extensibility than the other. CONCLUSIONS: Exact diameter and quality are not always the same among nylon monofilaments, even if they meet the standard for the designation 4-0. The present study indicates that slight differences of filament characteristics significantly affect lesion volume and its reproducibility. This result may explain some conflicting observations in this MCA occlusion model.

Animals↗

PubMed1995

Decrease in surface charge density of Klebsiella pneumoniae treated with cefodizime and enhancement of the phagocytic function of human polymorphonuclear leucocytes stimulated by the drug-treated bacteria.

Treatment of Klebsiella pneumoniae 109 with cefodizime, ceftazidime, cefbuperazone, cefotaxime or flomoxef at a sub-minimum inhibitory concentration (sub-MIC) (1/4 MIC) for 1 h altered its morphology. The bacteria treated with cefodizime at sub-MICs (1/8, 1/4 MIC) enhanced the chemiluminescencence (CL) of human polymorphonuclear leucocytes (PMNs), implying an increase in the production of active oxygen species in association with phagocytosis, whereas the cells treated with other cephalosporins at the same sub-MICs did not. Furthermore, a significant decrease in electrophoretic mobility was induced by the bacteria treated with cefodizime at sub-MICs (1/8, 1/4 MIC), but other cephalosporins neither increased nor decreased the electrophoretic mobility significantly. These findings suggested that cefodizime caused a morphological change, with a decrease in negative surface charge density of K. pneumoniae, more easily than ceftazidime, cefbuperazone, cefotaxime or flomoxef, followed by an increase in the phagocytic activity of PMNs.

Cefotaxime↗

PubMed1995

An investigation of gram-negative tannin-protein complex degrading bacteria in fecal flora of various mammals.

Gram-negative tannin-protein complex degrading bacteria (T-PCDB) were first isolated from animals except for the koala. The occurrence of T-PCDB in feces of 15 species of mammals with different feeding habits was investigated. T-PCDB occurred in 7 of 54 horses but they could not be isolated from other mammals tested. These T-PCDB comprised less than 0.1% of the facultative anaerobic microflora in horse feces and it was much less than that previously reported in koala feces ( > 60%). A total of 7 T-PCDB fecal isolates showed a range of phenotypic diversities. They were all Gram-negative rods of various sizes and shapes including coccoidal rod. Although all produced tannase, no strain showed to have gallate decarboxylase. A total of 23 representative strains belonging to the family Pasteurellaceae were also tested for tannase production. Two strains, Haemophilus actinomycetemcomitans NIAH-10202T and Haemophilus segnis NIAH-10183T which were isolated from human oral cavity were detected positive for tannase.

Animals↗

PubMed1995

Biosynthesis of lactacystin.

The biosynthesis of lactacystin, a new microbial metabolite which induces differentiation of neuroblastoma cells, was studied by the feeding experiments of various 13C-labeled compounds and NMR spectroscopic analysis. The feeding experiments showed that lactacystin consists of three containing gamma-lactam moiety arises by a condensation between methylmalonic semialdehyde and C alpha position of L-leucine, followed by intramolecular cyclization. Two diastereotopic methyls, C-11 and C-12 of lactacystin were found to originate from the pro-R and pro-S methyls of leucine, respectively, as shown by incorporating a new type of chiral 13C-labeled L-leucine.

Acetylcysteine↗

PubMed1995

Blue light-emitting diode built-in contact lens electrode can record human S-cone electroretinogram.

PURPOSE: To develop a contact lens electrode with a built-in blue light-emitting diode (LED) to record the electroretinogram from short-wave sensitive-cone (S-cone) electroretinogram (ERG) in humans. METHODS: The ERG was recorded using the blue LED (450 nm) built-in electrode under a yellow background illumination from a slide projector in five normal subjects, a patient with blue cone monochromatism, and a patient with fundus albipunctatus. For comparison, the ERG was also recorded using a yellow LED (566 nm) built-in electrode under the same background illumination in the normal subjects. RESULTS: The amplitude and the peak time of the b-wave recorded with 3-Hz blue stimuli were 5.1 to 12.4 microV and 63 to 68 msec, respectively in normal subjects, 7.3 microV and 65 msec in the patient with blue cone monochromatism, and 11.4 microV and 65 msec in the patient with fundus albipunctatus. Normal subjects responded to neither 30-Hz blue stimuli nor 3-Hz yellow stimuli. CONCLUSIONS: Results indicate that the b-wave recorded with 3-Hz blue stimuli is elicited from the S-cone system. This simple technique is useful for testing the human blue cone system.

Adult↗

PubMed1995

[Postoperative pulmonary stenosis after arterial switch operation, comparison in three methods of pulmonary reconstruction: modified Pacifico, autologous pericardial patch, and equine pericardial patch].

To prevent postoperative pulmonary stenosis in arterial switch operation for transposition of the great arteries, pulmonary reconstruction without patch augmentation (modified Pacifico method: Pa-group) and reconstruction using W-shaped fresh autologous pericardium (AW-group) were introduced instead of the former method using equine pericardium (XW-group). Postoperative pulmonary stenosis (RV-PA pressure gradient greater than 30 mmHg) was not seen among the 17 cases in the Pa-group (0%), and was seen in 2/14 (14.3%) in the AW-group and in 4/14 (29%) in the XW-group. Progressive increase in pressure gradient was seen in the XW-group in the midterm cardiac catheterization (p < 0.01), but such tendency was not observed in the Pa-group and the AW-group. Sectional area at the pulmonary valve ring, at the anastomotic site in the main pulmonary artery, and at the pulmonary branches just distal to the bifurcation, standardized by the body surface area, increased in the Pa-group and the AW-group, but were unchanged or slightly decreased in the XW-group in the midterm cardiac angiography. We believe that postoperative pulmonary stenosis can be best avoided if modified Pacifico method is used. The cases in which postoperative pulmonary stenosis or coronary artery compression is anticipated such as those with side-by-side aortopulmonary relationship or after pulmonary artery banding, should be operated upon using fresh autologous pericardial patch.

Humans↗

PubMed1995

Association of acquired color vision defects in blue cone monochromatism.

The retinal functions of a 43-year-old man with diabetic retinopathy in a family affected by blue cone monochromatism were studied. While changes in visual acuity and color vision were similar to those seen in patients affected by rod monochromatism, and his spectral sensitivities on high intensity background and his threshold versus intensity curve indicated only suggestive blue cone function, mass electroretinograms (ERG) findings demonstrated well preserved blue cone function. The disparity in blue cone function between psychophysical and mass electroretinographical evaluation may be caused by the difference in how much the fovea influenced each testing. Diabetic retinopathy most likely caused significant reduction of the psychophysical blue cone function and resulted in clinical findings similar to rod monochromatism. The mass blue cone ERG was useful to differentiate blue cone monochromatism from rod monochromatism in this diabetic patient.

Adult↗

PubMed1995

[Surgical results of valvuloplasty for common atrioventricular valve regurgitation in single ventricle].

From 1988 through 1994, 18 patients who had common atrioventricular valve regurgitation associated with single ventricle underwent valvuloplasty. All patients had isomerism heart (right isomerism: 16, left isomerism: 2). The preoperative degree of regurgitation was 3.3 +/- 0.4 (Sellers). Valvuloplasty was performed by two different procedures. Semi-circular annuloplasty was used in nine patients. Dividing the common atrioventricular valve orifice into two parts (bivalvation) with or without annuloplasty was used in nine. The concomitant procedures varied: three patients underwent systemic pulmonary shunt, two underwent repair of total anomalous pulmonary venous drainage, one underwent pulmonary arterial banding, five underwent bidirectional Glenn, shunt, and four underwent Fontan operation. One early death and three late deaths have occurred. The early postoperative degree of regurgitation was reduced to 1.3 +/- 1.0. In nine patients, however, the degree of regurgitation increased late postoperatively. Seven patients were reoperated on because of regurgitation: three patients had valve replacement and four had reannuloplasty. Increased incidence of deterioration of regurgitation in late period was seen in patients under 2 years old and those receiving a concomitant Blalock shunt. Lower event-free rate after 2 years was seen in patients with double inlet right or indeterminate ventricle and those underwent the annuloplasty alone. We conclude that the dividing common atrioventricular valve orifice into two parts with annuloplasty could effectively reduce the regurgitation in most patients with isomerism heart, and the concomitant ventricular unloading operation seems to offer promise for improving long-term results.

Adolescent↗

PubMed1995

Clinical evaluation of multifocal electroretinogram.

PURPOSE: To compare the multifocal electroretinogram (ERG) system to conventional ganzfeld and focal ERGs obtained from patients with known retinal diseases to assess its clinical applicability. METHODS: A multi-input system analysis was used to explore the field topography of ERG responses to local luminance modulation in patients with retinitis pigmentosa, pericentral pigmentary retinal dystrophy, branch retinal arterial occlusion, or idiopathic macular hole. RESULTS: The dysfunctional areas measured by multifocal ERG were compatible with those assumed by combined findings of ganzfeld and focal ERGs. However, the wave shapes of multifocal ERG in the retina with arterial occlusion differed from those of conventional focal ERG, suggesting that the negative and positive deflections shown in the first-order kernel of multifocal ERG may not correspond to conventional a- and b-waves of ERG. CONCLUSIONS: The multifocal ERG system is available for electroretinographic field mapping at the clinical level.

Adult↗

PubMed1995

[Suppressive rod-cone interaction in complete and incomplete congenital stationary night blindness].

Dark-adapted rods have a suppressive effect on cone response (suppressive rod-cone interaction: SRCI). This phenomenon has been applied to analyze the pathological mechanism of congenital stationary night blindness (CSNB), but the results have been discrepant among the investigators. Alexander et al reported that 2 individuals with CSNB exhibited a normal SRCI, but Arden and Hogg reported an absence of SRCI in 4 cases of CSNB. We evaluated SRCI in complete and incomplete CSNB. SRCI was tested by measuring luminance threshold for flicker detection (685nm, 1.7 degrees in diameter, 20Hz) across the horizontal meridian of the visual field without and with full-field background illumination. In twelve normal subjects, a reduction of the flicker threshold was observed during presentation of the background. Five cases with complete CSNB showed normal SRCI, but in one case we failed to detect SRCI except at one tested locus. Similarly 5 cases of incomplete CSNB showed normal SRCI, but in one case we failed to detect SRCI except at one tested locus. These results may indicate that SRCI is normal in both complete and incomplete CSNB, but in some cases, SRCI is absent because of localized retinal dysfunction.

Adolescent↗

PubMed1995

[Visual functions of dominantly inherited juvenile optic atrophy].

Visual functions including color vision and spectral sensitivity were investigated in 18 of 36 patients and in 2 persons with normal visual acuity in 8 families with dominantly inherited juvenile optic atrophy. Seven of the 8 families had at least one member who showed mainly acquired blue-yellow color vision deficiency. However, only 4 patients showed typical blue-yellow color vision deficiency, which suggested nonspecific characteristics of color vision deficiency in optic neural diseases. One family showed mainly acquired red-green color vision deficiency. Spectral sensitivity functions measured in 5 patients of 3 families showed sensitivity loss in the middle and long wavelength range as well as markedly decreased sensitivity in the short wavelength range. Decrease in spectral sensitivity in the short wavelength range or minimal blue-yellow color vision defect in a subject's brothers with normal visual acuity is interesting, but further study is needed because blue sensitivity decreases easily in various conditions.

Adolescent↗

PubMed1995

[Foveal cone densitometer and changes in foveal cone pigments with aging].

A foveal cone densitometer was built for measuring the kinetics of foveal cone pigments in human eyes. The light from a 500-W xenon lamp was divided into reference, measuring, and bleaching beams, and projected through an optical fiber leading to a modified fundus camera. After the light was projected into the ocular fundus, the reflected light (central 1 degree) was measured by a photomultiplier and the regeneration time and the two-way density were abstracted from the records. The two-way density, which is the decadic logarithm of the measuring-reference beam ratio under bleached conditions divided by the measuring-reference beam ratio under dark conditions, eliminated the artifacts caused by eye movement of blink. Reliable curves were obtained in 45 eyes out of 53 healthy Japanese subjects (age range, 9 to 82 years). The mean +/- standard deviation SD of the two-way density (log) and the time constant (sec) were 0.34 +/- 0.09 and 139.9 +/- 79.3, respectively. The time constant significantly increased with aging.

Adolescent↗

PubMed1995

Enzyme immunoassay of immunoreactive progastrin-releasing peptide(31-98) as tumor marker for small-cell lung carcinoma: development and evaluation.

Previously, using recombinant human progastrin-releasing peptide (ProGRP)(31-98), we developed a RIA for ProGRP(31-98) and demonstrated that the determination of serum ProGRP(31-98) was a reliable marker for small-cell lung carcinoma (SCLC) (Miyake et al., Cancer Res 1994;54:2136-40). Aiming for a more convenient assay system, we have now developed and evaluated a highly sensitive and specific ELISA for ProGRP(31-98). Only 50 microL of nonextracted serum is needed, and results are obtained in only 2 h. Intraassay and between-day CVs were 1.7-4.6% and 4.2-6.8%, respectively. The log-log calibration curve was linear to 1000 ng/L, and analytical recovery was 91.5-108.7%. The detection limit of this assay, 1.9 ng/L, means that basal concentrations of ProGRP(31-98) were detectable in all healthy subjects. The cutoff value, based on the mean + 3 SD of concentrations in 247 healthy subjects, was set to 45.1 ng/L. Serum concentrations exceeded this value in 18 of 25 SCLC patients, similar to the frequency of increased values found by RIA previously. In contrast, the frequency of increased serum ProGRP(31-98) in patients with nonmalignant pulmonary diseases or non-SCLC was quite low: 0% and 5.0%, respectively. Such results may justify a clinical trial for evaluating this ELISA for the diagnosis and monitoring of SCLC patients.

Amino Acid Sequence↗

PubMed1995

[A case of unresectable gastric cancer responding to combined therapy with intraperitoneal cisplatinum administration and continuous intravenous infusion of 5-fluorouracil].

A 41-year-old woman diagnosed as gastric cancer with peritoneal dissemination was admitted for operation. Exploratory laparotomy was done and a reservoir was implanted with intraperitoneal catheter. At the operation, CDDP (100 mg) was administered intraperitoneally. Four days after the operation, continuous intravenous infusion of 5-FU (250 mg) was carried out. CDDP was administered every four weeks for 6 times and 5-FU continuously for 194 days. Grade 2 toxicity (nausea, vomiting) was noted without myelosuppression and renal disturbance. The general condition of the patient was fairly improved. PS (performance status) improved from Grade 3 to Grade 1. Combined therapy with repeated intraperitoneal CDDP administration and continuous intravenous infusion of 5-FU is effective and safe for gastric cancer with peritoneal dissemination based on biochemical modulation.

Adult↗

PubMed1994

Pro-gastrin-releasing peptide(31-98) is a specific tumor marker in patients with small cell lung carcinoma.

Gastrin-releasing peptide (GRP) is a specific and an actively secreted product of small cell lung carcinoma (SCLC) cells. Based on this observation, we attempted to develop a new approach for early detection of SCLC and for monitoring therapeutic response in SCLC patients. Recombinant human ProGRP(31-98), a region common to three types of human ProGRP molecules, was synthesized, and a convenient radioimmunoassay system was developed; in this assay, the minimum detectable amount in serum was 10 pM when 0.1 ml of unextracted serum was used. Serum levels of immunoreactive ProGRP(31-98) were measured in 247 normal subjects, 180 patients with nonmalignant pulmonary diseases, 231 patients with non-SCLC, and 140 patients with SCLC. The percentages of subjects with the level greater than 10 pM in normal subjects and patients with nonmalignant pulmonary diseases and with non-SCLC were 1.2, 2.2, and 3.0%, respectively. In contrast, 76% of patients with SCLC had elevated levels; the positive rates in SCLC patients with limited and extensive diseases were 73 and 79%, respectively, indicating that the serum Pro-GRP(31-98) level could serve as a reliable tumor marker in SCLC patients, even at a relatively early stage of this disease. Moreover, changes in the serum ProGRP(31-98) showed excellent correlation with the therapeutic responses in SCLC patients. These results indicate that the determination of serum ProGRP(31-98) levels plays an important role in the diagnosis and treatment of SCLC patients.

Biomarkers, Tumor↗