Search PubMed⌕ Search

Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

At least 127 records · Page 7Linked to original sources
PubMed2000

Comparative in vitro activity of telithromycin (HMR 3647), three macrolides, amoxycillin, cefdinir and levofloxacin against gram-positive clinical isolates in Japan.

The in vitro activities (MIC and MBC) of telithromycin (HMR 3647) against clinical isolates in Japan were investigated in comparison with those of erythromycin A, clarithromycin, azithromycin, amoxycillin, cefdinir and levofloxacin. Telithromycin was more potent than the reference compounds against erythromycin A-susceptible or resistant Streptococcus pneumoniae isolates possessing either mef (mefA or mefE) genes or the ermB gene. Against erythromycin A-susceptible or inducibly resistant Staphylococcus aureus and erythromycin A-susceptible and intermediate Enterococcus faecalis, telithromycin was highly active.

Amoxicillin↗
PubMed2000

Characterization of intracellular Ca(2+) increase in response to progesterone and cyclic nucleotides in mouse spermatozoa.

Rises in intracellular Ca(2+) concentration ([Ca(2+)](i)) caused by progesterone, an inducer of the acrosome reaction, or by cyclic nucleotides, possible second messengers, were investigated by Ca(2+) imaging of the head of individual mouse sperm. Progesterone induced a [Ca(2+)](i) rise in a dose-dependent manner (4-40 microM), primarily in the postacrosomal region. For 20-microM progesterone, Ca(2+) responses occurred in 42% of sperm, separated into two types: transient type (60% of responding cells; duration, 1-1.5 min; mean amplitude, 335 nM) and prolonged type (40%; >3 min; 730 nM). Prolonged responses required higher doses of progesterone, and their occurrence was enhanced significantly by preincubation for 2-4 h as compared with transient responses. 8-Bromo-cGMP (0.3-3 mM) induced a [Ca(2+)](i) rise more effectively than did 8-bromo-cAMP. For 1-mM 8-bromo-cGMP, 90% of cells exhibited transient Ca(2+) responses (approximately 1 min; 220 nM), independently of the preincubation time. In Ca(2+)-free medium, most sperm showed no Ca(2+) response to progesterone and 8-bromo-cGMP. Pimozide, a Ca(2+) channel blocker, completely blocked prolonged responses and partially inhibited transient responses. These results suggest that progesterone activates at least two distinct Ca(2+) influx pathways, with fast or slow inactivation kinetics, and some sperm show both types of response. A cyclic nucleotide-mediated process could participate in the progesterone-induced [Ca(2+)](i) rise.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2000

A clinically oriented video-based system for quantification of eyelid movements.

A field-worthy system was developed to quantify the eyelid movements in clinical sites. The system consists of a home-use charge-coupled device video camera, a processing unit, and a personal computer. A white marker of 4-mm diameter and 30-mg weight is attached to the lower margin of the upper eyelid. The processing unit automatically detects the vertical displacement of the upper edge of the marker. One marker is attached to each eye so that the movements of the both eyelids are measured with one camera simultaneously. The measurement error of the system was evaluated in experiments on eight healthy subjects and eight patients with eyelid paralysis. The mean of the absolute error of peak amplitudes occurring in 2 min was 0.81 mm, with the worst error being +1.7 mm. The reproducibility of the mean peak amplitude measured on five consecutive days was within 1 mm. The mean peak amplitudes of both eyes were measured preoperatively and postoperatively for approximately three months for three patients who were operated on to remove vestibular schwannoma. The results demonstrated basic clinical utility of the system.

Adult↗
PubMed2000

Detection of significant bacteriuria by automated urinalysis using flow cytometry.

A new flow cytometry-based automated urine analyzer, the UF-50, was evaluated for its ability to screen urine samples for significant bacteriuria. One hundred eighty-six urine specimens from patients attending an outpatient clinic of a university-based hospital were examined. The results obtained with the UF-50 were compared with those obtained by conventional quantitative urine culture. The UF-50 detected significant bacteriuria with a sensitivity of 83.1%, a specificity of 76.4%, a positive predictive value of 62.0%, a negative predictive value of 90.7%, and an accuracy of 78.5%. These results are comparable to those obtained by previously reported screening procedures. Besides detecting significant bacteriuria, the UF-50 can also perform routine urinalysis, including measurement of concentrations of red blood cells, white blood cells, epithelial cells, and casts, within 70 s. This capability renders this new flow cytometry-based urine analyzer superior to previously reported rapid screening methods.

Bacteria↗
PubMed2000

Regulation of CDK7-carboxyl-terminal domain kinase activity by the tumor suppressor p16(INK4A) contributes to cell cycle regulation.

The eukaryotic cell cycle is regulated by cyclin-dependent kinases (CDKs). CDK4 and CDK6, which are activated by D-type cyclins during the G(1) phase of the cell cycle, are thought to be responsible for phosphorylation of the retinoblastoma gene product (pRb). The tumor suppressor p16(INK4A) inhibits phosphorylation of pRb by CDK4 and CDK6 and can thereby block cell cycle progression at the G(1)/S boundary. Phosphorylation of the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II by general transcription factor TFIIH is believed to be an important regulatory event in transcription. TFIIH contains a CDK7 kinase subunit and phosphorylates the CTD. We have previously shown that p16(INK4A) inhibits phosphorylation of the CTD by TFIIH. Here we report that the ability of p16(INK4A) to inhibit CDK7-CTD kinase contributes to the capacity to induce cell cycle arrest. These results suggest that p16(INK4A) may regulate cell cycle progression by inhibiting not only CDK4-pRb kinase activity but also by modulating CDK7-CTD kinase activity. Regulation of CDK7-CTD kinase activity by p16(INK4A) thus may represent an alternative pathway for controlling cell cycle progression.

Amino Acid Sequence↗
PubMed2000

Is preinfarction angina related to the presence or absence of coronary plaque rupture?

OBJECTIVE: To analyse the prodrome of acute myocardial infarction in relation to the plaque morphology underlying the infarct. DESIGN: A retrospective investigation of the relation between rupture and erosion of coronary atheromatous plaques and the clinical characteristics of acute myocardial infarction. The coronary arteries of 100 patients who died from acute myocardial infarction were cut transversely at 3 mm intervals. Segments with a stenosis were examined microscopically at 5 micrometer intervals. The clinical features of the infarction were obtained from the medical records. RESULTS: A deep intimal rupture was encountered in 81 plaques, whereas 19 had superficial erosions only. There were no differences in the location of infarction, the incidence of hypertension, diabetes mellitus, or hyperlipidaemia, diameter stenosis of the infarcted related artery, Killip class, Forrester's haemodynamic subset, or peak creatine kinase between plaque rupture and plaque erosion groups. The presence of plaque rupture was associated with significantly greater incidences of leucocytosis, current smoking, and sudden or unstable onset of acute coronary syndrome. In patients with unstable preinfarction angina, new onset rest angina rather than worsening angina tended to develop more often in the plaque rupture group than in the plaque erosion group (p = 0.08). CONCLUSIONS: Plaque rupture causes the sudden onset of acute myocardial infarction or unstable preinfarction angina, which may be aggravated by smoking and inflammation.

Aged↗
PubMed2000

Job strain, social support in the workplace, and haemoglobin A1c in Japanese men.

OBJECTIVES: To examine the association between job strain (defined in the model of job demands and job control) and social support at the workplace with levels of glycosylated haemoglobin A1c (HbA1c) METHODS: All male employees aged 40-60 in a manufacturing firm, Japan, were invited to take part in the study. A blood sample was taken from the participants and HbA1c (%) was measured. Job strain and social support at the workplace were assessed with the job content questionnaire (JCQ). After excluding those who had a history of diabetes mellitus or other chronic diseases, data from 268 male day workers were analyzed. RESULTS: Age adjusted average concentrations of HbA1c were significantly higher in the highest quartile group of job strain or the lowest quartile group of social support at the workplace (p<0.05). Multiple linear regression analysis indicated that job strain was significantly and positively related to HbA1c (p<0.05), whereas social support at the workplace was significantly and negatively related to HbA1c (p<0.05), both after controlling for other covariates. CONCLUSIONS: Greater job strain and lower social support at the workplace may be associated with increased concentrations of HbA1c. Increased blood glucose may be a physiological mediator between job strain or social support at the workplace and coronary heart disease.

Adult↗
PubMed2000

Rapid increase in plasma growth hormone after low-intensity resistance exercise with vascular occlusion.

Hormonal and inflammatory responses to low-intensity resistance exercise with vascular occlusion were studied. Subjects (n = 6) performed bilateral leg extension exercise in the seated position, with the proximal end of their thigh compressed at 214 +/- 7.7 (SE) mmHg throughout the session of exercise by means of a pressure tourniquet. Mean intensity and quantity of the exercise were 20% of 1 repetition maximum and 14 repetitions x 5 sets, respectively. In each set, the subjects repeated the movement until exhaustion. Plasma concentrations of growth hormone (GH), norepinephrine (NE), lacate (La), lipid peroxide (LP), interleukin-6 (IL-6), and activity of creatine phosphokinase (CPK) were measured before and after the exercise was finished and the tourniquet was released. Concentrations of GH, NE, and La consistently showed marked, transient increases after the exercise with occlusion, whereas they did not change a great deal after the exercise without occlusion (control) done at the same intensity and quantity. Notably, concentration of GH reached a level approximately 290 times as high as that of the resting level 15 min after the exercise. IL-6 concentration showed a much more gradual increase and was maintained at a slightly higher level than in the control even 24 h after exercise. Concentrations of LP and CPK showed no significant change. The results suggest that extremely light resistance exercise combined with occlusion greatly stimulates the secretion of GH through regional accumulation of metabolites without considerable tissue damage.

Adult↗
PubMed2000

Differential involvement of opioid receptors in stress-induced antinociception caused by repeated exposure to forced walking stress in mice.

We examined the effects of repeated exposure to forced walking stress for 6 h once a day for 0, 6 and 9 consecutive days on formalin-induced paw licking in mice. In each observation period, stress-induced antinociception (SIA) was observed only in the late phase (from 10 to 30 min), but not in the early phase (from 0 to 10 min) of formalin-induced paw licking in mice. Moreover, it was hard to develop tolerance even by daily exposure to stress for 6 days, although SIA for 9 days decreased compared with those for 0 and 6 days. Naloxone (10 mg/kg), an opioid-receptor antagonist, was effective in reducing the SIA induced by forced walking stress for 6 days and/or 9 days, but not for 0 days. Furthermore, the experiments with selective opioid-receptor antagonists, beta-funaltrexamine (mu) naltrindol (delta), or nor-binaltorphimine (kappa) demonstrated that SIA induced by forced walking stress for 9 successive days may be mediated through opioid delta- and kappa-receptors. Finally, although SIA seemed to be a unitary phenomenon, the present results strengthened the idea that SIA is induced by exposure to forced walking stress with characteristics dependent on the duration of exposure.

Animals↗
PubMed2000

Dexamethasone-induced cardiogenic shock rescued by percutaneous cardiopulmonary support (PCPS) in a patient with pheochromocytoma.

A 52-year-old man with pheochromocytoma had cardiogenic shock and was rescued using a percutaneous cardio pulmonary supporting system. After recovery, diagnostic tests including metaiodobenzylguanidine scintigraphy and computed tomography, revealed the pheochromocytoma which was confirmed by histology. It was postulated that the acute episode was induced by intra-joint dexamethasone, which increased the production of epinephrine and augmented the sensitivity of cardiomyocytes for catecholamine, thereby inducing the cardiomyopathy.

Adrenal Gland Neoplasms↗
PubMed2000

Circulating hepatocyte growth factor as a marker of thrombus formation in unstable angina pectoris.

A new enzyme-linked immunosorbent assay can detect 10 pg/ml of human hepatocyte growth factor (HGF). Circulating HGF was significantly higher in patients with unstable angina (296+/-184 pg/ml, mean+/-SD, n=36) than in healthy volunteers (201+/-64 pg/ml, n=250, p<0.0001). Individual concentrations exceeded the mean control value +2 SD (329 pg/ml) in 12 of the 36 (33%) patients with unstable angina. The present study indicates that this new, sensitive HGF assay can successfully detect thrombosis in patients with unstable angina.

Adolescent↗
PubMed2000

Markers for bone metabolism in a long-lived case of thanatophoric dysplasia.

We report a male patient with type 1 thanatophoric dysplasia, now eight years old, having a mutation in the FGFR3 gene. Radiological examination at birth revealed that the ribs and the bones of the extremities were very short and vertebral bodies were greatly reduced in height with wide intervertebral spaces. The femurs were shaped like French telephone receivers. Because of respiratory insufficiency due to the narrow thorax, the patient has been intubated and supported by continuous mechanical ventilation since the day after birth. Since 5 years of age, despite sufficient caloric intake, his body weight never increased above 4700 g, body height 49.0 cm, head circumference 46.1 cm, and chest circumference 35.8 cm. Acanthosis nigricance and huge bilateral coral-like urolithiases has been present. His mental development was severely retarded but he was able to make emotional expressions. Although developments in motor functions could not be assessed, his neurodevelopmental milestones in social relationships and language perception seemed to be at the level of a 10 to 12 month old. His bone maturation was also severely retarded. All of the assays of his serum and urinary bone formation- or resorption-related substances were within normal limits for age. Therefore, bone formation as well as bone resorption activities seemed normal and not responsible for his growth retardation.

Biomarkers↗
PubMed2000

Esophageal perforation associated with profound shock successfully managed with hemodynamic assistance using percutaneous cardiopulmonary support.

A 51-year-old man was admitted to our hospital with complaints of severe chest pain, nausea, and vomiting. These symptoms had progressed rapidly and he was in shock. It was necessary to make a correct diagnosis as early as possible. However, the hemodynamic condition of the patient deteriorated rapidly before a definitive diagnosis could be established in spite of conventional therapies. Under hemodynamic assistance with percutaneous cardiopulmonary support (PCPS), a final diagnosis of esophageal perforation was made by esophagography. Our report illustrates a new application of PCPS for highly selected cases of noncardiogenic shock as a "bridge" until an accurate diagnosis is made and a specific treatment is applied.

Cardiopulmonary Bypass↗
PubMed2000

[In vitro activities of carbapenem antibiotics against the various clinical isolates].

The annual changes of antibacterial activities of beta-lactam antibiotics, mainly carbapenem antibiotics, were investigated against 5 bacterial species, S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, which had been isolated from the clinical materials at Toho University Omori Hospital during the period of 1995 to 1997. In addition, antibacterial activities against other main bacterial strains isolated from the clinical materials during 1997 were also determined. The five bacterial species on which annual changes of the sensitivity were investigated did not show any remarkable trend to increase in resistance to the carbapenem antibiotics tested. The antibacterial activities of the carbapenem antibiotics against MRSA were weak, and MIC90 values were between 25 and 50 micrograms/ml. In S. marcescens and P. aeruginosa on which high resistance by the production of metallo-beta-lactamase has become a problem in recent years, there were no remarkable changes in annual changes of sensitivities. Especially, MIC90 valuses of the carbapenem antibiotics against P. aeruginosa were between 12.5 and 25 micrograms/ml, 4 to 8 times better than that of PIPC, like the case of CAZ. Furthermore, the carbapenem antibiotics showed strong antibacterial activities against clinically important 16 bacterial species, from Gram-positive to Gram-negative bacteria.

Carbapenems↗
PubMed2000

Sigmoid neobladder in women after radical cystectomy.

PURPOSE: Neobladder reconstruction using an intestinal segment is the common procedure of choice in men after cystectomy. Recently this procedure has been extended to women. We present our surgical and functional experience with the sigmoid neobladder in women. MATERIALS AND METHODS: A total of 11 women 49 to 74 years old (mean age plus or minus standard deviation 60 +/- 8.5) with transitional cell carcinoma of the bladder underwent lower urinary tract reconstruction with a modified sigmoid neobladder after nerve and urethral support sparing cystectomy. After at least 3 months voiding pattern and continence status were evaluated. Pressure flow studies and uroflowmetry were performed, the urethral pressure profile and neocystourethral angle were measured, and blood chemistry was analyzed. RESULTS: After at least 3 months complete daytime continence was achieved in 2 patients, while 8 had mild stress incontinence. At night 8 of the 11 women (72.7%) were continent with or without voiding at regular intervals. All except 1 patient voided to completion. Of the 2 patients with complete continence 1 needed clean intermittent catheterization 4 months postoperatively. Mean maximal urinary flow was 19.9 +/- 10.5 ml. per second. Excluding the woman who required catheterization mean residual urine volume was 15 +/- 13.7 ml. Postoperatively maximal urethral pressure was slightly lower and functional urethral length was about 10 mm. shorter than preoperatively. The mean neocystourethral angle was 131.9 +/- 21.7 degrees. Mean pH, bicarbonate and base excess were 7.38 +/- 0.03, 23. 48 +/- 2.34 mmol./l. and -0.92 +/- 2.50, respectively. CONCLUSIONS: After nerve and urethral support sparing cystectomy a modified sigmoid neobladder may be constructed in women to obtain satisfactory continence and voiding results.

Aged↗
PubMed2000

Comparative evaluation of conjugate vaccines in the Haemophilus influenzae infection model.

We used a murine model of Haemophilus influenzae type b (Hib) infection to analyze the immunologic response to two commercially available PRP conjugate vaccines (HbOC, PRP-T). The mortality rate in mice infected with a large dose of the bacteria after vaccination with HbOC or PRP-T at two and three doses was significantly lower than in non-vaccinated mice and mice vaccinated by one dose. Furthermore, for infections caused by a small bacterial dose, the mortality rate in mice vaccinated with one, two, or three doses was significantly lower than in non-vaccinated mice. The induction level of anti-PRP antibodies, especially IgG, in serum of mice vaccinated by two or three doses was higher than in those vaccinated with a single dose. Our results indicate that the dose of vaccine influences its efficacy in protecting against Hib infection. Our results also showed a lack of difference between two different PRP conjugate vaccines.

Animals↗
PubMed2000

[Improved gastric patch method for esophagocardioplasty in esophageal achalasia].

We performed esophagocardioplasty with the gastric patch (original GP) as the treatment of first choice in patients with esophageal achalasia. However, postoperative reflux esophagitis occurred in many due to secretory dysfunction of the gastric mucosa implanted in the mediastinum. We therefore developed two modifications of the gastric patch technique (GP II and GP III) which do not involve implantation of the gastric mucosa in the esophagus. Twenty-three patients have undergone the modified GP II procedure in our institution. Postoperative changes in the esophagus were examined fluoroscopically, and it was found that esophageal diameter increased from an average 2.9 +/- 0.6 cm to 5.2 +/- 1.0 cm at an average follow-up of 7.1 months (p < 0.01). All 23 patients experienced amelioration of symptoms, even though some reddening was still present in the lower esophagus, with a maximum follow-up of 8 years. Based on these results, the modified GP procedures are an acceptable open surgery modality for esophagocardioplasty in esophageal achalasia.

Adult↗