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Biomedical subjects

Tsutomu Yamazaki

Publications and source records attributed to Tsutomu Yamazaki.

At least 19 recordsLinked to original sources
PubMed2006

Amlodipine versus angiotensin II receptor blocker; control of blood pressure evaluation trial in diabetics (ADVANCED-J).

BACKGROUND: The coexistence of type 2 diabetes mellitus and hypertension increases the risk of cardiovascular diseases. The U.K. Prospective Diabetes Study has shown that blood pressure control as well as blood glucose control is efficient for prevention of complications in hypertensive patients with diabetes mellitus. However, some reports have shown that it is difficult to control the blood pressure and the concomitant use of a plurality of drugs is needed in hypertensive patients with diabetes mellitus. In recent years renin-angiotensin system depressants are increasingly used for the blood pressure control in diabetic patients. Particularly in Japan, angiotensin II (A II) antagonists are increasingly used. However, there is no definite evidence of the point of which is efficient for the control, the increase in dose of A II antagonist or the concomitant use of another drug, in hypertensive patients whose blood pressure levels are inadequately controlled with A II antagonist. METHODS/DESIGN: Hypertensive patients of age 20 years or over with type 2 diabetes mellitus who have been treated by the single use of AII antagonist at usual doses for at least 8 weeks or patients who have been treated by the concomitant use of AII antagonist and an antihypertensive drug other than calcium channel blockers and ACE inhibitors at usual doses for at least 8 weeks are included. DISCUSSION: We designed a multi-center, prospective, randomized, open label, blinded-endpoint trial, ADVANCED-J, to compare the increases in dose of A II antagonist and the concomitant use of a Ca-channel blocker (amlodipine) and A II antagonist in hypertensive patients with diabetes mellitus, whose blood pressure levels were inadequately controlled with A II antagonist. This study is different from the usual previous studies in that home blood pressures are assessed as indicators of evaluation of blood pressure. The ADVANCED-J study may have much influence on selection of antihypertensive drugs for treatment in hypertensive patients with diabetes mellitus. It is expected to give an important hint for considering the validity of selection of antihypertensive drugs from the aspects not only of the antihypertensive effect but medical cost-effectiveness.

Adult↗
PubMed2006

Bacteriological monitoring of water reservoirs in oxygen humidifiers: safety of prolonged and multipatient use of prefilled disposable oxygen humidifier bottles.

Bacterial colony counts in water specimens from oxygen humidifiers that used reusable water reservoirs were compared with counts in water specimens from humidifiers that used prefilled disposable reservoir bottles to evaluate the effects of prolonged and multipatient use of humidifiers. Bacteria were detected after 1 week of operation in water specimens collected from many humidifiers with reusable reservoirs, but no bacteria were detected in water specimens from disposable bottles for up to 12 weeks during use of the humidifier by multiple patients.

Colony Count, Microbial↗
PubMed2006

Bacterial propagation in reusable water reservoirs in a humidified oxygen supply system.

Bacterial colony counts in reusable water reservoirs in a humidified oxygen supply system maintained only by the addition of nonsterilized water, with or without washing (conventional procedure), were examined. Bacteria were detected in all the reservoirs even before the operation of the oxygen suppliers, and colony counts of more than 1 x 10(2)/ml of bacteria were detected in some reservoirs without washing. Many bacteria were also detected in many reservoirs, after the operation of the oxygen suppliers, indicating that bacteria had contaminated the water reservoirs and propagated during this operation. These results suggest that it is not recommended to maintain these water reservoirs by the conventional procedure.

Bacteria↗
PubMed2006

Clinical evaluation of macrolide-resistant Mycoplasma pneumoniae.

Macrolide-resistant Mycoplasma pneumoniae (MR M. pneumoniae) has been isolated from clinical specimens in Japan since 2000. A comparative study was carried out to determine whether or not macrolides are effective in treating patients infected with MR M. pneumoniae. The clinical courses of 11 patients with MR M. pneumoniae infection (MR patients) treated with macrolides were compared with those of 26 patients with macrolide-susceptible M. pneumoniae infection (MS patients). The total febrile days and the number of febrile days during macrolide administration were longer in the MR patients than in the MS patients (median of 8 days versus median of 5 days [P = 0.019] and 3 days versus 1 day [P = 0.002], respectively). In addition, the MR patients were more likely than the MS patients to have had a change of the initially prescribed macrolide to another antimicrobial agent (63.6% versus 3.8%; odds ratio, 43.8; P < 0.001), which might reflect the pediatrician's judgment that the initially prescribed macrolide was not sufficiently effective in these patients. Despite the fact that the febrile period was prolonged in MR patients given macrolides, the fever resolved even when the initial prescription was not changed. These results show that macrolides are certainly less effective in MR patients.

Adolescent↗
PubMed2006

Comparison of PCR for sputum samples obtained by induced cough and serological tests for diagnosis of Mycoplasma pneumoniae infection in children.

Passive agglutination (PA) and immunoglobulin M (IgM), IgA, and IgG enzyme-linked immunosorbent assays (ELISAs) for the diagnosis of Mycoplasma pneumoniae were compared with PCR testing of sputum samples obtained from children with lower respiratory tract infections. The sensitivity and specificity of PA were 80.3% and 92.3% at a titer of 1:80. ELISA was found to be less sensitive than PA.

Agglutination↗
PubMed2006

The inhibitory effect of disodium cromoglycate on the growth of Chlamydophila (Chlamydia) pneumoniae in vitro.

Chlamydophila (Chlamydia) pneumoniae is associated with asthma and several other respiratory illnesses. Disodium cromoglycate (DSCG) is known to inhibit both immediate and late asthmatic responses. In this study, the inhibitory effect of DSCG on the growth of C. pneumoniae was examined by minimum inhibitory concentration (MIC) and pre-inoculation minimal cidal concentration (MCC) assays using HL cells and C. pneumoniae AR-39. DSCG below the clinically relevant concentration inhibited the growth of C. pneumoniae in a dose-dependent manner in both the MCC and MIC assays. The inhibitory effect was also time-dependent in the MCC assay at 20 mg/ml of DSCG. These results warrant further clinical study on the connection between C. pneumoniae infections and use of DSCG.

Cell Line↗
PubMed2006

Proposed new score to rate the strength of evidence and its application to large-scale clinical trials of angiotensin-receptor blockers.

BACKGROUND: Many large-scale clinical studies appear to be interpreted with bias and with hindsight. To select the best treatment, accurate evaluation of randomized controlled trials (RCTs) and fair comparison of the results using the concept of evidence-based medicine are critical. A scoring system has been developed to rate the scientific strength of evidence and thereby provide guidance for best clinical practice and for large-scale RCTs of angiotensin-receptor blockers (ARBs). METHOD AND RESULTS: Positive evidence scores (ESs) were given based on whether specified study endpoints were proven and whether treatments tested made significant progress over current usual therapy. Retrospective ad hoc analyses data were not counted, in order to simplify the system and to avoid hindsight interpretations, even in cases that were medically significant. In fact, in more than half of the large-scale trials with ARBs examined, ad-hoc analyses had been retroactively performed. When such post-hoc analyses were not used, the ESs were positive with candesartan and valsartan for treatment of heart failure, irbesartan and losartan for nephropathy and losartan for hypertension. Applying the ES system, losartan was judged to be an ARB with the strongest evidence covering a wide range of clinical relevance. CONCLUSION: ES is useful for quantifying and comparing the strength of evidence obtained in large-scale RCTs of ARBs. Several problems related to rating the evidence obtained from clinical trials were recognized in this study.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2006

Randomized study of angiotensin II type 1 receptor blocker vs dihydropiridine calcium antagonist for the treatment of paroxysmal atrial fibrillation in patients with hypertension.

BACKGROUND: Mega trials of rhythm vs rate control could not demonstrate the usefulness of available antiarrhythmic drugs, so a more effective and safer therapy for atrial fibrillation (AF) is now required. One candidate is the so-called "upstream therapy", which refers to the blockade of upstream modifying elements (renin - angiotensin system, cathecholamines, oxidative stress etc) that contribute to the arrhythmogenic substrate. METHODS AND RESULTS: The Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II study) is a randomized comparative evaluation of an angiotensin II type 1 blocker (candesartan) and a dihydropiridine calcium blocker (amlodipine), both combined with antithrombotic therapy, as an antiarrhythmic therapy for the treatment of paroxysmal AF (PAF) associated with hypertension. To test the usefulness of this therapy, this study will reveal the recurrence rate of asymptomatic as well as symptomatic PAF during 1-year of treatment with candesartan or amlodipine, using daily transtelephonic monitoring. CONCLUSIONS: The J-RHYTHM II study will follow 400 patients with PAF and hypertension who were treated at approximately 50 sites throughout Japan, and will provide clinically important information.

Amlodipine↗
PubMed2006

Japanese randomized trial for investigation of a combined therapy of amiodarone and implantable cardioverter defibrillator in patients with ventricular tachycardia and fibrillation: the Nippon ICD Plus Pharmachologic Option Necessity study design.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) are the most effective therapy in reducing the mortality of patients with life-threatening ventricular tachyarrhythmias. However, the ICD cannot prevent the recurrence of tachycarida attacks and that limits the clinical usefulness of them. The Nippon ICD Plus Pharmachologic Option Necessity (NIPPON) trial was designed as the first prospective randomized study to test the hypothesis whether amiodarone could improve the patient's clinical outcome by reducing the amount of ICD therapy in the Japanese patient population. METHODS AND RESULTS: Approximately 400 patients with organic heart disease and spontaneous episode(s) of sustained ventricular tachycardia/fibrillation (VT/VF) will be randomly assigned to one of 2 groups; the amiodarone group and non-amiodarone group. Both groups of patients will be followed at least for 24 months. The end-point committee will adjudicate events in a blinded fashion. The primary end-points of this study are determination of the appropriate therapy from the ICD and alteration of the assigned treatment because of its harmful effects and/or frequent ICD therapies. CONCLUSION: The NIPPON study is expected to confirm our understanding of the prognostic and therapeutic usefulness of adjuvant amiodarone therapy for patients with an ICD and with a history of sustained VT/VF.

Amiodarone↗
PubMed2006

Genetic and phenotypic characterization of Haemophilus influenzae type b isolated from children with meningitis and their family members in Vietnam.

To investigate Haemophilus influenzae type b (Hib) infection in Vietnamese children under the age of 5 years, cerebrospinal fluid (CSF) samples from patients with meningitis were screened for Hib, and isolates were subjected to evaluation of susceptibility to 12 antibiotics, biotyping, and genotyping with pulsed-field gel electrophoresis (PFGE). The major biotype was type II (68.3%), followed by type I (22.8%). Among 79 Hib isolates, 45 (57%) were beta-lactamase-producing and ampicillin-resistant (44 and 1 isolates produced TEM-1- and ROB-1-type beta-lactamases, respectively), and 34 isolates (43%) were beta-lactamase-nonproducing and ampicillin-sensitive. No beta-lactamase-nonproducing and ampicillin-resistant isolates were found. The PFGE patterns of Hib isolates were highly divergent, but most could be classified into three clusters. We also investigated Hib colonization in household contacts of patients, and found that Hib isolates from the CSF of patients and from nasopharyngeal cavities of household contacts showed the same PFGE patterns. This observation suggested that household contacts of patients are a possible reservoir of Hib.

Adolescent↗
PubMed2005

Prevalence of antibodies against Simkania negevensis in a healthy Japanese population determined by the microimmunofluorescence test.

Simkania negevensis has been associated with bronchiolitis in infants and community-acquired pneumonia in adults. Reports of exposure to this microorganism are only available from Israel, North America and Western Europe. Currently, no standard method for diagnosis of S. negevensis infection has been established nor have prevalence rates been shown in Japan. For the first time we demonstrated the ability of the microimmunofluorescence (MIF) test to detect S. negevensis-specific immunoglobulin G and exposure to S. negevensis in Japan. The positive rate in healthy volunteers was 4.3% (25/588), with rates increasing with age. Results indicate the usefulness of the MIF test as a serological method for detecting S. negevensis-specific antibodies. A standard serological test for infection with S. negevensis is needed.

Adult↗
PubMed2005

In vitro activity of beta-lactams, macrolides, telithromycin, and fluoroquinolones against clinical isolates of Streptococcus pneumoniae: correlation between drug resistance and genetic characteristics.

The in vitro activity of antimicrobial agents against Streptococcus pneumoniae was determined using 16 strains of penicillin-susceptible S. pneumoniae (PSSP) and 26 strains of penicillin intermediately resistant S. pneumoniae (PISP) + penicillin-resistant S. pneumoniae (PRSP) in Japan. The minimum inhibitory concentrations (MICs) of potent antibiotics, including eight beta-lactams (benzylpenicillin, ampicillin, cefotiam, cefepime, cefditoren, faropenem, panipenem, and biapenem), three macrolides (erythromycin, clarithromycin, and azithromycin), telithromycin, and three fluoroquinolones (ciprofloxacin, levofloxacin, and gatifloxacin), were determined. Twenty-three strains exhibited genetic variations at pbp1a + pbp2x + pbp2b, which are genetic-PRSP (g-PRSP). g-PISP strains accounted for 62.5% (10/16) of the PSSP strains. The existence of an abnormal pbp gene conferred not only penicillin resistance but resistance to cephems; however, panipenem and biapenem had potent in vitro efficacy against alterations. Regarding the macrolide resistance mechanisms (mefA or ermB): 16 isolates had only mefA, 18 isolates had ermB, and 2 isolates had both mefA and ermB. There was no correlation between the existence of an abnormal pbp gene and the existence of the mefA gene or the ermB gene.

Anti-Infective Agents↗
PubMed2005

Biosynthesized tea polyphenols inactivate Chlamydia trachomatis in vitro.

Biosynthesized tea polyphenols showed antichlamydial activity against Chlamydia trachomatis D/UW-3/Cx and L2/434/Bu using cell culture. The most active compounds were (-)-epigallocatechin gallate and (-)-epicatechin gallate, followed by (-)-epicatechin (EC). (+)-Epicatechin and (-)-epigallocatechin were intermediate. EC was the least toxic. These results warrant evaluation of tea polyphenols as topical antichlamydial agents.

Anti-Bacterial Agents↗
PubMed2005

In vitro inhibitory effects of hinokitiol on proliferation of Chlamydia trachomatis.

The inhibitory effects of hinokitiol (beta-thujaplicin) on Chlamydia trachomatis D/UW-3/Cx were shown by MIC, minimum lethal concentration (MLC), and preinoculation minimal microbicidal concentration assays using HeLa 229 cells. The MIC and the MLC were both 32 microg/ml. Further evaluation of hinokitiol as a topical agent against C. trachomatis is warranted.

Anti-Infective Agents↗
PubMed2005

Genetic analysis in a patient with recurrent cardiac myxoma and endocrinopathy.

A 60 year-old male was referred for treatment of a cardiac myxoma in the right atrium. He had a past history of left atrial cardiac myxoma at age 49 and pituitary microadenoma related to acromegaly at age 55. He did not have a family history of cardiac neoplasm or endocrinopathy. The intracardiac tumor was resected and its pathology was compatible with myxoma. A diagnosis of Carney complex (CNC) was made because the diagnostic criteria of this neoplastic syndrome were satisfied by the presence of recurrent cardiac myxoma, endocrine tumor and spotty skin pigmentation. In genetic analysis novel frame shift mutation was detected in exon 2 in a heterozygous fashion in the causative gene of CNC, protein kinase A regulatory subunit 1 alpha (PRKAR1A). This genetic mutation is thought to cause haplo-insufficiency of PRKAR1A resulting in tumorigenesis. Although it is the most common, usually benign, cardiac tumor, myxoma can cause a critical clinical situation and thus detecting the PRKAR1A mutation can assist with prognosis.

Acromegaly↗