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Biomedical subjects

M Saito

Publications and source records attributed to M Saito.

At least 73 records · Page 4Linked to original sources
PubMed2004

Association of increased platelet-associated immunoglobulins with thrombocytopenia and the severity of disease in secondary dengue virus infections.

Severe thrombocytopenia and increased vascular permeability are two major characteristics of dengue haemorrhagic fever (DHF). To develop a better understanding of the roles of platelet-associated IgG (PAIgG) and IgM (PAIgM) in inducing thrombocytopenia and its severity of disease in patients with secondary dengue virus infection, the relationship between the PAIgG or PAIgM levels and disease severity as well as thrombocytopenia was examined in 78 patients with acute phase secondary infection in a prospective hospital-based study. The decrease in platelet count during the acute phase recovered significantly during the convalescent phase. In contrast, the increased levels of PAIgG or PAIgM that occurred during the acute phase of these patients decreased significantly during the convalescent phase. An inverse correlation between platelet count and PAIgG or PAIgM levels was found in these patients. Anti-dengue virus IgG and IgM activity was found in platelet eluates from 10 patients in an acute phase of secondary infection. Increased levels of PAIgG or PAIgM were significantly higher in DHF than those in dengue fever (DF). An increased level of PAIgM was associated independently with the development of DHF, representing a possible predictor of DHF with a high specificity. Our present data suggest that platelet-associated immunoglobulins involving antidengue virus activity play a pivotal role in the induction of thrombocytopenia and the severity of the disease in secondary dengue virus infections.

Adolescent↗
PubMed2004

Impact of adiposity and plasma adipocytokines on diabetic angiopathies in Japanese Type 2 diabetic subjects.

AIMS: Adipocytokines, products from adipose tissue, have biological activities on the vascular system, and may affect diabetic angiopathy. In this study, we assessed the relationship between adiposity and plasma adipocytokine levels, and investigated the clinical significance of adiposity and plasma adipocytokine levels on diabetic micro- and macroangiopathy in Type 2 diabetic subjects. METHODS: We studied 231 Japanese Type 2 diabetic subjects (135 men and 96 women, aged 60.4 +/- 12.3 years, body mass index 24.8 +/- 5.2 kg/m2). We measured adipocytokine [adiponectin, leptin, resistin, and tumour necrosis factor (TNF)-alpha] levels, lipid profiles and urine albumin excretion. We also performed optic fundus examination and measured carotid intramedia thickness (IMT) using B-mode ultrasonography, and the localization of fat with abdominal computed tomography. A group of 93 subjects with microalbuminuria or overt proteinuria was compared with the other 148 to assess the effect on nephropathy. A group of 191 eyes with simple retinopathy or more advanced changes was compared with 263 eyes without retinal changes to assess the effect on retinopathy. RESULTS: Plasma adiponectin level was negatively correlated with both visceral (r = -0.37, P < 0.01) and subcutaneous (r = -0.25, P < 0.01) fat areas. Resistin concentration was positively related with visceral fat area (r = 0.15, P < 0.05). Adiponectin concentration was positively correlated with age (r = 0.26, P < 0.01). TNF-alpha was correlated with IMT (r = 0.16, P < 0.05) after correction for age. Logistic regression analysis indicates a 4085 times greater chance of having retinopathy with a one unit increase in TNF-alpha (pmol/l) and a 30.64 times greater chance of having nephropathy with one unit increase in leptin (nmol/l). CONCLUSIONS: The present observations suggest that visceral and subcutaneous fat has an impact on microangiopathy as well as macroangiopathy, possibly through different adipocytokines.

Adipocytes↗
PubMed2004

A new form of retinopathy associated with myocardial infarction treated with percutaneous coronary intervention.

AIM: To report a new form of retinopathy that was observed in patients who had undergone percutaneous coronary intervention (PCI) following acute myocardial infarction (AMI). METHODS: Serial ophthalmological examinations were conducted in 40 patients who underwent PCI. Thirty patients were diagnosed with AMI, and another 10 had stable angina pectoris. RESULTS: Cotton wool spots developed in 17 (57%) patients from the group with AMI undergoing PCI (n = 30) within 2 months. Of these, 41% (seven patients) also developed superficial haemorrhages. Retinopathy was most prominent 1-2 months after AMI and then tended to become quiescent afterwards, without treatment. CONCLUSION: We have identified a new form of retinopathy in patients with AMI that spontaneously subsides without treatment.

Adult↗
PubMed2004

Nicorandil versus isosorbide dinitrate as adjunctive treatment to direct balloon angioplasty in acute myocardial infarction.

OBJECTIVE: To compare the effects of nicorandil (a hybrid ATP sensitive potassium channel (K+(ATP) channel) opener/nitric oxide donor) with those of isosorbide dinitrate (ISDN) on myocardial microcirculation and cardiac function in patients with acute myocardial infarction (AMI) who had undergone reperfusion treatment by direct balloon angioplasty. DESIGN: Double blind randomised study. PATIENTS: 60 patients with AMI in Killip class I. INTERVENTIONS: Patients were assigned into two treatment groups: a nicorandil group (n = 30) and an ISDN group (n = 30). Each drug was infused intravenously at 6 mg/h for 72 hours starting at admission and was administered directly to the treated coronary artery immediately after angioplasty. RESULTS: Compared with ISDN, nicorandil more frequently caused recovery of ST segment elevation just after reperfusion (15 of 27 (55.5%) in the nicorandil group v 5 of 26 (19.2%) in the ISDN group, p = 0.006). The nicorandil group had higher values of averaged peak velocity 40 minutes after reperfusion (mean (SD) 24.8 (13.3) cm/s v 16.0 (11.1) cm/s, p = 0.045) and higher values of regional wall motion of the infarcted area three weeks after onset of AMI (-1.78 (1.11) v -2.50 (1.04) SD/chord, p = 0.046). CONCLUSIONS: A combination of nicorandil drip infusion starting before reperfusion and intracoronary injection immediately after reperfusion is more effective than a similarly performed infusion of ISDN in preserving myocardial microcirculation in the reperfused AMI area. The nicorandil regimen resulted in better left ventricular regional wall motion.

Angioplasty, Balloon↗
PubMed2004

Multifocal angiomyolipoma affecting the liver and lung without tuberous sclerosis.

The occurrence of angiomyolipoma (AML) in tissue other than the kidney is uncommon, as is multiple AML developing exclusively in organs other than the kidney. This report describes a case in which AML occurred multifocally in the liver and lung, but spared the kidney, and which might have been associated with tuberous sclerosis complex (TSC). A Japanese woman underwent a partial hepatectomy for a suspected malignant liver tumour at the age of 57. The tumour consisted predominantly of a trabecular arrangement of myoid cells with a sinusoidal pattern and inflammatory cell infiltration, and was diagnosed as a primary liver AML by HMB-45 immunoreactivity. Five years later, multiple nodules were found in both lungs, for which video assisted thoracic surgery was performed. The tumour showed a mixture of epithelioid cells containing HMB-45 positive material and mature lipocytes, and was subsequently diagnosed as AML. Molecular analysis of both lesions showed no allelic loss of the TSC1 and TSC2 regions. Molecular analysis of the tumours ruled out an association with TSC, and both liver and lung lesions displayed benign histological features, so that these were probably multifocal lesions of AML without TSC.

Angiomyolipoma↗
PubMed2004

G2 chromatid damage and repair kinetics in normal human fibroblast cells exposed to low- or high-LET radiation.

Radiation-induced chromosome damage can be measured in interphase using the Premature Chromosome Condensation (PCC) technique. With the introduction of a new PCC technique using the potent phosphatase inhibitor calyculin-A, chromosomes can be condensed within five minutes, and it is now possible to examine the early damage induced by radiation. Using this method, it has been shown that high-LET radiation induces a higher frequency of chromatid breaks and a much higher frequency of isochromatid breaks than low-LET radiation. The kinetics of chromatid break rejoining consists of two exponential components representing a rapid and a slow time constant, which appears to be similar for low- and high-LET radiations. However, after high-LET radiation exposures, the rejoining process for isochromatid breaks influences the repair kinetics of chromatid-type breaks, and this plays an important role in the assessment of chromatid break rejoining in the G2 phase of the cell cycle.

Animals↗
PubMed2004

Characterization of dental epithelial progenitor cells derived from cervical-loop epithelium in a rat lower incisor.

Dental epithelial progenitor cells differentiate into various cell types during development of tooth germs. To study this mechanism, we produced immortalized dental epithelial progenitor cells derived from the cervical-loop epithelium of a rat lower incisor. The expression patterns of cytokeratin 14, nerve growth factor receptor p75, amelogenin, Notch2, and alkaline phosphatase were examined by immunohistochemistry in both lower and higher cell densities. The patterns of each were compared in the dental epithelium of rat lower incisors. The results demonstrated that these cells could produce ameloblast lineage cells, stratum intermedium cells, stellate reticulum, and outer enamel epithelium. Furthermore, fibroblast growth factor 10 stimulated proliferation of dental progenitor cells and subsequently increased the number of cells expressing alkaline phosphatase. These results suggest that fibroblast growth factor 10 plays a role in coupling mitogenesis of the cervical-loop cells and the production of stratum intermedium cells in rat incisors.

Alkaline Phosphatase↗
PubMed2004

Serum amyloid A, C-reactive protein and remnant-like lipoprotein particle cholesterol in type 2 diabetic patients with coronary heart disease.

BACKGROUND: Serum amyloid A (SAA) and C-reactive protein (CRP) have been suggested to be involved in the process of coronary heart disease (CHD) and to be potential markers and/or predictors of CHD. Remnant-like lipoprotein particles (RLPs), which are regarded as atherogenic remnant lipoprotein, are reported to be increased in type 2 diabetic patients. We assessed the association of CHD with SAA, CRP and RLP-cholesterol in type 2 diabetic patients. METHODS: One hundred and twenty-six diabetic patients without CHD and 41 patients with CHD were recruited from our hospital. Plasma SAA was measured by the latex agglutination nephelometric immunoassay. Plasma high-sensitivity CRP was measured by a latex immunoturbidity method. Plasma RLP-cholesterol was measured by an immunoabsorption enzyme method. RESULTS: The mean standard deviation values of RLP-cholesterol in patients with and without CHD were 0.22 (0.26) mmol/L and 0.15 (0.10) mmol/L, respectively (P <0.05). Median (interquartile ranges) for SAA in patients with and without CHD were 7.4 (4.2-11.2) mg/L and 3.9 (2.2-5.9) mg/L, respectively (P <0.001). Median (interquartile ranges) for CRP in patients with and without CHD was 1.14 (0.45-2.08) mg/L and 0.43 (0.19-1.25) mg/L, respectively (P <0.001). For all patients, the Spearman rank correlation statistics for RLP-cholesterol compared with SAA and with CRP were 0.213 (P <0.05) and 0.301 (P <0.01), respectively. CONCLUSION: These data suggest that SAA, CRP and RLP-cholesterol are increased in type 2 diabetic patients with CHD, and that the inflammatory proteins correlate with remnant lipoprotein.

Aged↗
PubMed2004

The value of counting BCG scars for interpretation of tuberculin skin tests in a tuberculosis hyperendemic shantytown, Peru.

SETTING: The tuberculin skin test (TST) is widely used as a diagnostic or screening test for Mycobacterium tuberculosis infection and disease. A peri-urban shantytown in the desert hills of south Lima, Peru, highly endemic for tuberculosis, and where bacille Calmette-Guérin (BCG) vaccine had been given in multiple doses until 1995. OBJECTIVE: To analyze the effect of multiple BCG vaccines on TST in a community-based setting. DESIGN: Point-prevalence survey of TST reactions of 572 people aged 6-26 years from 255 households. TST reactions were compared to the observed number of BCG scars and other potential risk factors (age, living with a TST-positive person, and contact with active tuberculosis). RESULT: People with two or more scars had significantly larger reactions, even after adjusting for potential risk factors. The adjusted population attributable fraction of being TST-positive and having two or more BCG scars was 26%. CONCLUSION: There is no demonstrated benefit of repeat BCG vaccination. We therefore recommend that physicians take into consideration the number of BCG scars when interpreting the TST and that programs give no more than one BCG vaccination.

Adolescent↗
PubMed2004

[Total removal of infected pacemaker lead with cardiopulmonary bypass; report of a case].

The incidence of infection after pacemaker implant has been reported to occur rarely but it's one of the severe complication. Pacemaker lead sometimes imbedded in the right atrial and ventricular wall, and it seemed to be difficult to remove the pacemaker lead by closed techniques. The optimal treatment is total removal generator and pacing lead, therefore, it is necessary to remove with cardiopulmonary bypass. Septicemia caused by infections retained pacemaker lead developed in an 87-year-old man. Following antibiotic therapy, the lead was successfully removed by cardiotomy on cardiopulmonary bypass. Total removal with cardiopulmonary bypass would be recommended.

Aged↗
PubMed2004

[Surgical treatment for the valvular disease through partial sternotomy].

213 patients who underwent surgical treatment for the valvular disease through partial sternotomy were studied. We started the minimally invasive valvular surgery in July 1997. All the valvular diseases were indicated for the minimally invasive surgery except for the annulo-aortic ectasia and the concomitant disease with coronary artery bypass surgery. Ascending aorta was selected as an arterial cannulation place if we could choice it through intraoperative echocardiography. Venous cannulae 22-24 Fr were inserted into the venae cavae directly or through right atrium. Negative pressure venous drainage (maximally 90 mmHg) was performed if necessarily. We did single approach as possible. Mortality rate was 3.8%. We could complete 96.2% of our series as a minimally invasive surgery. Post operative intensive care unit (ICU) stay and hospital stay through partial sternotomy were significantly shorter than those through full sternotomy.

Aged↗
PubMed2003

Molecular comparison of waxy null alleles in common wheat and identification of a unique null allele.

PCR selection markers for the identification of null waxy alleles were used to screen for waxy mutations in 168 common wheat cultivars. In all cultivars where the Wx-B1 protein was absent, the Wx-B1 allele was identical to the previously identified mutation carried by Kanto 107. Although most cultivars missing the Wx-A1 protein also carried the same Wx-A1 mutation as found in Kanto 107, all of the Turkey Wx-A1 mutants produced a different PCR fragment, implying the presence of a different mutation. Sequencing of this fragment indicated the mutation, which consisted of a 173-bp insertion in an exon, was in a different location than the previously identified Wx-A1 mutation. An 8-bp duplication of the Wx-A1 sequence flanked each end of the insertion, and an element with reverse complementary sequences was present at both ends of the insertion. These structures correspond with the features of class II transposable elements. Hence, the Turkey null Wx-A1 mutation was likely caused by the movement of a transposon, and this spontaneous mutation appears to be present in a limited geographical area.

Alleles↗
PubMed2003

Proinsulin C-peptide increases nitric oxide production by enhancing mitogen-activated protein-kinase-dependent transcription of endothelial nitric oxide synthase in aortic endothelial cells of Wistar rats.

AIMS/HYPOTHESIS: Recent studies have suggested that proinsulin C-peptide improves vascular functions, possibly through nitric oxide (NO) production. To clarify the molecular mechanisms of vascular NO production induced by C-peptide, we examined the effects of C-peptide on NO production and NO synthase expression in rat aortic endothelial cells in connection with mitogen-activated protein kinase (MAPK) activation. METHODS: Aortic endothelial cells were isolated from female Wistar rats, cultured to confluence, and serum-starved for 24 h before treatment with C-peptide. Nitric oxide production was measured by the DAF-2 fluorescence dye method and relative amounts of endothelial nitric oxide synthase (eNOS) protein and its mRNA were semi-quantified by western blot and RT-PCR analyses respectively. Activation of MAPK was estimated by western blot detection of activity-related phosphorylation and in vitro kinase assay. RESULTS: Stimulation of cells with C-peptide for 3 h doubled NO production, which was suppressed by the NO synthase inhibitor, N(G)-nitro- L-arginine methyl ester (L-NAME). Stimulation also increased mRNA and protein contents of eNOS in a manner sensitive to the transcription inhibitor actinomycin D. It did not affect inducible NO synthase mRNA. C-peptide also induced rapid phosphorylation and activation of extracellular signal-regulated kinase (ERK, also known as p44/42MAPK), but not of p38MAPK. In cells pretreated with the ERK inhibitor PD98059 the C-peptide-elicited increase of NO production and eNOS was abrogated in a dose-dependent manner; suppression of ERK phosphorylation induced by C-peptide also occurred. CONCLUSIONS/INTERPRETATION: Our results show that C-peptide increases NO production by increasing eNOS protein contents through ERK-dependent up-regulation of eNOS gene transcription. This could explain some actions of C-peptide on the vasculature, indicating a pivotal role for C-peptide in vascular homeostasis.

Animals↗
PubMed2003

Neuropathological analysis in spinal muscular atrophy type II.

We performed a neuropathological analysis, including in situ nick end labeling (ISEL) and immunohistochemistry, of two cases of clinicogenetically confirmed infantile spinal muscular atrophy (SMA) type II. Both cases showed severe reduction of the motor neurons and gliosis in the spinal cord and brain stem, although the occurrences of central chromatolysis and ballooned neurons were not frequent. Clark's and lateral thalamic nuclei, which are usually altered in SMA type I, were spared, whereas Betz cells in the precentral gyrus and large myelinated fibers in the lateral funiculus were reduced in number. Regarding apoptosis, only the younger case demonstrated a few ISEL-positive nuclei in the dorsal horn, with reduced Bcl-x expression level in the Purkinje cells. Unlike SMA type I, the expression of neurofilaments was not disturbed and the reduction in synaptophysin expression level in the anterior horn was mild. An oxidative stress-related product was deposited in atrophic motor neurons in the spinal cord, and neurons with nuclei immunoreactive for 8-hydroxy-2'-deoxyguanosine were found in the lateral thalamus. In contrast, the expression of glial glutamate transporters was not altered. These data suggest that oxidative stress and, to a lesser extent, apoptotic cell death, but not disturbed neurofilament metabolism or excitotoxicity, may be involved in neurodegeneration in SMA type II.

Adult↗
PubMed2003

Papanicolaou tests and molecular analyses using new fluid-based specimen collection technology in 3000 Japanese women.

A fluid-based Papanicolaou test has been established to improve sample collection and preparation. This study was the first large-scale investigation in Japan to examine the feasibility of using fluid-based Papanicolaou specimens to detect human papillomavirus (HPV) using Hybrid Capture II and polymerase chain reaction (PCR). Three thousand patients who visited Keio University Hospital between October 2000 and February 2001 were enrolled in the study. The results of the fluid-based Papanicolaou tests corresponded well with those of conventional Papanicolaou smears (96.8% concordance). The sensitivities of cervical neoplasia detection using the fluid-based Papanicolaou test (73.9%) and Hybrid Capture II (76.3%, P=0.55) were not significantly different. Among the cervical intraepithelial neoplasia 3 and squamous cell carcinoma specimens, HPV 16 and HPV 52 were predominantly detected using the PCR method. Although some DNA samples extracted from the fluid-based specimens were degradaded, PCR and direct sequencing could be performed without difficulty even after 1 year of specimen storage. We conclude that fluid-based Papanicolaou specimens can be applied to investigate HPV infection.

DNA, Viral↗
PubMed2003

Resonant neutral-particle emission in collisions of electrons with peptide ions in a storage ring.

Electron-biomolecular ion collisions were studied using an electrostatic storage ring with a merging beam technique for singly protonated peptides (angiotensin I, II, and III). A strong neutral-particle emission at around 6.5 eV was found in addition to neutrals from recombination at low energies. The rates of the high-energy peak greatly decreased with a slight decrease in the number of amino-acid residues from angiotensin I to III. These results suggest that some peptide bonds were selectively cleaved.

Angiotensins↗
PubMed2003

Sonographic assessment of the cervix before, during and after a uterine contraction is effective in predicting the course of labor.

OBJECTIVE: To investigate whether the degree of change in cervical length during a uterine contraction is predictive of subsequent progression of labor. METHODS: The subjects were 73 uncomplicated parturient women at term. We observed the cervix before, during and after a uterine contraction by transvaginal ultrasound in the first stage of labor and determined the degree of cervical shortening during the contraction relative to the cervical length before contraction. We related the degree of cervical shortening to labor patterns at the time of the ultrasound examination, which were retrospectively determined by reviewing the partogram. RESULTS: The cervix was shortened in length by about 50% on average during a uterine contraction in the normal course of labor. The degree of cervical shortening was significantly greater in the normal latent and active phases than it was in the prolonged latent phase, protracted active phase and false labor, whereas there were no differences between the former two phases nor between the latter three phases. Nulliparous and parous women exhibited almost the same degree of shortening in the normal latent and active phases. CONCLUSIONS: Real-time ultrasound observation of the cervix during uterine contraction could help differentiate inefficient uterine contractions from normal ones and thus predict the subsequent course of labor.

Adolescent↗