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Biomedical subjects

M Koide

Publications and source records attributed to M Koide.

At least 19 recordsLinked to original sources
PubMed2006

Detection of legionella species in clinical samples: Comparison of polymerase chain reaction and urinary antigen detection kits.

BACKGROUND: Recently, two excellent methods have been used for the diagnosis of Legionnaires' disease: urinary antigen detection and PCR. The purpose of the present study is to analyze and evaluate the sensitivity and specificity of three different urinary antigen detection kits as well as PCR. MATERIALS AND METHODS: A total of 148 samples were collected from 33 patients between 1993 and 2004. These consisted of 73 urine samples obtained from 33 patients, 57 serum samples provided by 29 patients, and 18 respiratory tract specimens from 13 patients. Three commercially available kits were used to detect urinary antigen. For the 5S PCR reaction, primers L5SL2 and L5SR84 were used. RESULTS: Positive results were shown in all patients' urine (representing 79.5% of total samples) using the Binax EIA kit, in 93.9% patients (representing 75.3% samples) using the Binax NOW immunochromatographic kit, and in 90.9% (representing 72.6% samples) using the Biotest EIA kit. Urine samples from 12.1% patients (representing 6.8% of total samples), serum samples from 41.4% patients (representing 35.1% of total samples), and respiratory samples from 84.6% patients (representing 88.9% of total samples) showed positive results with PCR. CONCLUSION: In testing urine of legionellosis patients, it was suggested that three kits were all valuable tools for diagnosis of legionellosis. Since over one-third of patients' serum samples and most respiratory specimens showed positive results with PCR, the addition of PCR for testing of these samples might be useful, particularly in cases of culture negative and serum antibody negative patients.

Adult↗
PubMed2006

[Valve-in-valve replacement of primary tissue valve failure of bovine pericardial valve minor].

A 73-year-old woman who underwent mitral valve replacement with a 31 mm Carpentier Edwards Pericardial Xenograft 19 years ago. She revealed sudden onset of a grade IV/VI a seagull like diastolic murmur at the apex, and severe hematuria. Echocardiography demonstrated severe mitral regurgitation. These findings were consistent with acute primary tissue valve failure. Therefore we performed emergency reoperation. At operation, valve leaflet was torn at the commissural stitch, and bioprosthesis strut was buried in the left posterior ventricular wall. The mitral prosthetic valve replaced with a 25 mm CarboMedics OptiForm using a technique of valve-in-valve replacement. This procedure would be one option for replacement of bioprosthetic mitral valve.

Aged↗
PubMed2005

Actinobacillus actinomycetemcomitans Y4 capsular polysaccharide induces IL-1beta mRNA expression through the JNK pathway in differentiated THP-1 cells.

Capsular polysaccharide from Actinobacillus actinomycetemcomitans Y4 (Y4 CP) induces bone resorption in a mouse organ culture system and osteoclast formation in mouse bone marrow cultures, as reported in previous studies. We also found that Y4 CP inhibits the release of interleukin (IL)-6 and IL-8 from human gingival fibroblast (HGF). Thus Y4 CP induces various responses in localized tissue and leads to the secretion of several cytokines. However, the effects of Y4 CP on human monocytes/macrophages are still unclear. In this study, THP-1 cells, which are a human monocytic cell line, were stimulated with Y4 CP, and we measured gene expression in inflammatory cytokine and signal transduction pathways. IL-1beta and tumour necrosis factor (TNF)-alpha mRNA were induced from Y4 CP-treated THP-1 cells. IL-1beta mRNA expression was increased according to the dose of Y4 CP, and in a time-dependent manner. IL-1beta mRNA expression induced by Y4 CP (100 microg/ml) was approximately 7- to 10-fold greater than that in the control by real-time PCR analysis. Furthermore, neither PD98059, a specific inhibitor of extracellular signal-regulated kinase nor SB203580, a specific inhibitor of p38 kinase prevented the IL-1beta expression induced by Y4 CP. However, JNK Inhibitor II, a specific inhibitor of c-Jun N-terminal kinase (JNK) prevented the IL-1beta mRNA expression induced by Y4 CP in a concentration-dependent manner. These results indicate that Y4 CP-mediated JNK pathways play an important role in the regulation of IL-1beta mRNA. Therefore, Y4 CP-transduced signals for IL-1beta induction in the antibacterial action of macrophages may provide a therapeutic strategy for periodontitis.

Aggregatibacter actinomycetemcomitans↗
PubMed2004

In vitro biocompatibility of a new titanium-29niobium-13tantalum-4.6zirconium alloy with osteoblast-like MG63 cells.

BACKGROUND: Titanium-29niobium-13tantalum-4.6zirconium (TiNb) has recently been developed as a new implant material. TiNb is composed of non-toxic elements and has a lower modulus of elasticity than the other titanium alloys. However, its biocompatibility has not been adequately characterized. The aim of this study was to evaluate the biocompatibility of TiNb using an osteoblast-titanium co-culture system. METHODS: MG63 cells were cultured on three kinds of titanium disks: TiNb, pure titanium (pTi), and titanium-6aluminum-4vanadium (TiAl), prepared with two different surfaces, a polished and acid-etched surface and a machined-grooved surface. The surface topography and roughness were evaluated by scanning electron microscopy (SEM). After 48 hours culture, the number of proliferating cells and prostaglandin E2 (PGE2) production in the culture supernatant were determined. RESULTS: There was no significant difference in surface roughness among the three titanium disks with a polished and acid-etched surface. After 48 hours of culture, the number of cells was significantly reduced on pTi and TiAl compared to TiNb and the control. PGE2 production was significantly higher on pTi than on TiAl, TiNb, and the control. We further examined the effect of surface roughness on PGE2 production using machine-grooved titanium disks. While pTi and TiAl stimulated the production of PGE2 depending on surface roughness, roughened TiNb did not affect PGE2 production. CONCLUSIONS: These results suggest that TiNb may exhibit favorable biocompatibility because it has an efficient surface topography for cell proliferation, and the level of PGE2 production does not depend on surface roughness. We conclude that TiNb may be useful as an implant material.

Alloys↗
PubMed2001

Expression pattern of novel chick T-box gene, Tbx20.

Little is known about the molecular mechanisms involved with the initial specifications of the cardiac mesoderm. In order to identify potential regulatory factors that play important roles in early heart specification, we attempted to isolate the chick H15-related T-box gene and analyze its expression pattern during early development. The chick Tbx20 gene was found to be highly homologous to human, mouse, and zebrafish hrT/Tbx20. Its expression was initially detected in the posterior lateral mesoderm, after which it expanded to the anterior and was intensively co-expressed with a cardiogenic gene, Nkx2.5, in the anterior lateral mesoderm.

Amino Acid Sequence↗
PubMed2001

Macrophage inflammatory protein-1alpha is an osteoclastogenic factor in myeloma that is independent of receptor activator of nuclear factor kappaB ligand.

A complementary DNA expression library derived from marrow samples from myeloma patients was recently screened and human macrophage inflammatory protein-1alpha (hMIP-1alpha) was identified as an osteoclastogenic factor expressed in these samples. hMIP-1alpha enhanced osteoclast (OCL) formation in human marrow cultures and by highly purified OCL precursors in a dose-dependent manner (5-200 pg/mL). Furthermore, hMIP-1alpha enhanced OCL formation induced by human interleukin-6 (IL-6), which is produced by marrow stromal cells when they interact with myeloma cells. hMIP-1alpha also enhanced OCL formation induced by parathyroid hormone-related protein (PTHrP) and receptor activator of nuclear factor kappaB ligand (RANKL), factors also implicated in myeloma bone disease. Time-course studies revealed that the hMIP-1alpha acted during the last 2 weeks of the 3-week culture period. Reverse transcription-polymerase chain reaction analysis showed that the chemokine receptors for hMIP-1alpha (CCR1 and CCR5) were expressed by human bone marrow and highly purified early OCL precursors. Furthermore, hMIP-1alpha did not increase expression of RANKL. These data demonstrate that hMIP-1alpha is an osteoclastogenic factor that appears to act directly on human OCL progenitors and acts at the later stages of OCL differentiation. These data further suggest that in patients with myeloma, MIP-1alpha produced by myeloma cells, in combination with RANKL and IL-6 that are produced by marrow stromal cells in response to myeloma cells, enhances OCL formation through their combined effects on OCL precursors. (Blood. 2001;97:3349-3353)

Bone Marrow Cells↗
PubMed2001

Role of FK506-binding protein 12 in development of the chick embryonic heart.

A cDNA encoding chicken FK506-binding protein 12 (FKBP12) was isolated and sequenced. The predicted amino acid sequence of the chicken protein shows high homology to those of FKBP12 proteins of other species ranging from human to frog. The possible role of FKBP12 in chick embryonic cardiac development was examined. Northern blot analysis revealed that FKBP12 mRNA is distributed widely in chick embryos, being especially abundant in the heart; the amount of FKBP12 mRNA in the embryonic heart decreased with time. Administration of FK506 to chick embryos at 7 to 9 days resulted in marked cardiac enlargement. FK506 also reduced the expression of myosin, induced a more elongated cell morphology, and impaired network formation in cultured chick embryonic cardiomyocytes. These results suggest that FKBP12 is important in the regulation of contractile function and phenotypic expression in chick cardiomyocytes during embryonic development.

Amino Acid Sequence↗
PubMed2001

Distribution of Legionella longbeachae and other legionellae in Japanese potting soils.

The distribution of Legionella longbeachae and Legionella spp. in Japanese potting soils was examined. Thirty samples were collected: 13 were composted wood products, 11 were potting mixes (containing composted wood products, sand, mineral fertilizer, and manure), 2 were peatmoss, 3 were peatmoss-sand mixes (containing peatmoss and sand), and 1 was a sample of hydroponic clay balls. A suspension of each sample was made in sterile distilled water and acidified, and 100 microl was plated on buffered charcoal yeast extract alpha (BCYEalpha) agar containing modified wadowsky yee (MWY) supplement and pimaricin (direct method). In parallel, each suspension was incubated at 33 degrees C for several months to allow for amebic enrichment, if present; the suspensions were then plated onto culture media as described above (enrichment method). A total of 46 strains of legionellae were isolated from 22 of the 24 samples (13 composted wood products, 11 potting mixes). L. longbeachae was isolated from 9 samples. The most predominant species of legionellae in potting soils was Legionella bozemanii, which was isolated from 13 samples. Legionella spp. and L. micdadei were isolated from 8 and 7 samples each. Compared with findings in potting soils in Australia (26/45; 58%), Japanese potting soils had an only 8.3% (2/24) isolation rate for L. longbeachae by the direct method. The components of composted wood products were broadleaves such as oak and Japanese oak, in contrast to the pine and eucalypt used in Australia, which may account for the different isolation rates. However, the amebic enrichment method was useful in increasing the recovery of legionellae in potting soils. Legionellae were not isolated from the peatmoss samples, a result identical to findings in surveys of similar material in Europe.

Bacteriological Techniques↗
PubMed2001

Effect of repeated local minocycline administration on periodontal healing following guided tissue regeneration.

BACKGROUND: Infection after a periodontal surgical site has been prepared for guided tissue regeneration (GTR) is one of the common complications that can compromise healing. The purpose of this study was to assess the effect of repeated local antimicrobial therapy following GTR for improving clinical attachment gains, and to histologically evaluate the various cell populations and bacterial contamination of the retrieved expanded polytetrafluoroethylene membrane (ePTFE). METHODS: Forty periodontal intrabony defects in 40 patients were treated by a flap procedure that included the use of ePTFE membranes to allow GTR. Patients were randomly assigned to 2 treatment groups: 20 patients were treated with the ePTFE alone (control group), and the other 20 were treated with the ePTFE combined with the administration of a weekly repeated local application of minocycline ointment for 8 weeks after membrane placement (test group). The membranes were retrieved 6 weeks after the initial surgery and sectioned serially in a coronal-apical plane. The sections were then divided into 9 fields and examined by light microscopy for the presence of inflammatory cells and oral bacteria. Clinical measurements were taken at the time of baseline examination and at a 6-month follow-up examination after removal of the ePTFE. RESULTS: At the 6-month follow-up examination, control and test groups showed significant improvement; i.e., reduction in the probing depth and increased clinical attachment gain compared with the values at the baseline examination. However, the mean clinical attachment gain of the test group (3.0+/-0.3 mm) was significantly (P = 0.03) greater than that of the control group (2.0+/-0.5 mm). Histologically, the total number of the cells of both groups was similar. In both groups, mononuclear cells were dominant and fibroblasts, neutrophils, and plasma cells were rarely encountered. There was a tendency for the number of macrophages to be somewhat higher in the control group. The total number of bacteria in the test group was significantly less than that in the control group. The number of bacteria in both control and test groups decreased toward the apical portion. CONCLUSIONS: In the present study, clinical attachment gain of intrabony defects following GTR was favorable with repeated local administration of minocycline ointment. However, a complete microbial eradication was not achieved.

Administration, Topical↗
PubMed2000

Microtubule depolymerization normalizes in vivo myocardial contractile function in dogs with pressure-overload left ventricular hypertrophy.

BACKGROUND: Because initially compensatory myocardial hypertrophy in response to pressure overloading may eventually decompensate to myocardial failure, mechanisms responsible for this transition have long been sought. One such mechanism established in vitro is densification of the cellular microtubule network, which imposes a viscous load that inhibits cardiocyte contraction. METHODS AND RESULTS: In the present study, we extended this in vitro finding to the in vivo level and tested the hypothesis that this cytoskeletal abnormality is important in the in vivo contractile dysfunction that occurs in experimental aortic stenosis in the adult dog. In 8 dogs in which gradual stenosis of the ascending aorta had caused severe left ventricular (LV) pressure overloading (gradient, 152+/-16 mm Hg) with contractile dysfunction, LV function was measured at baseline and 1 hour after the intravenous administration of colchicine. Cardiocytes obtained by biopsy before and after in vivo colchicine administration were examined in tandem. Microtubule depolymerization restored LV contractile function both in vivo and in vitro. CONCLUSIONS: These and additional corroborative data show that increased cardiocyte microtubule network density is an important mechanism for the ventricular contractile dysfunction that develops in large mammals with adult-onset pressure-overload-induced cardiac hypertrophy.

Animals↗
PubMed2000

Protein kinase cdelta and alpha are involved in the development of vasospasm after subarachnoid hemorrhage.

We have previously shown the enhanced activity of protein kinase C in the membrane fraction of the canine vasospastic artery after subarachnoid hemorrhage, which increased with progression of angiographic vasospasm. This study examined identification of protein kinase C isoforms in the canine basilar artery, and the changes in expression and/or translocation of each isoform during the development of vasospasm. Vasospasm was produced by using the "two-hemorrhage" canine model in the basilar artery, and angiographic progression of vasospasm was assessed consecutively. Two isoforms, protein kinase Calpha and delta were identified in basilar arteries by Western blotting. Densitometric analysis showed that the expression of protein kinase Cdelta in the membrane fraction was significantly increased in the earlier stage, and protein kinase Calpha was increased later as vasospasm progressed. These results indicate that protein kinase Cdelta and alpha isoforms may play a significant role in the development and maintenance of vasospasm.

Actins↗
PubMed2000

Antithrombotic treatment (argatroban vs. heparin) in coronary angioplasty in angina pectoris: effects on inflammatory, hemostatic, and endothelium-derived parameters.

To evaluate the suitability of two anticoagulants (heparin vs. argatroban) as adjunctive drugs during and after elective conventional percutaneous transluminal coronary angioplasty, we compared the changes in inflammatory, hemostatic, and endothelium-derived markers in groups of patients with stable angina treated with the two drugs during percutaneous transluminal coronary angioplasty. Twenty-seven patients were randomly allocated to either group 1 (15 patients who received an empiric dose of heparin and aspirin as anticoagulant), or group 2 (12 patients who received an alternative regimen of argatroban and aspirin). Both drugs were administered as a bolus followed by continuous infusion for 96 hours during and after percutaneous transluminal coronary angioplasty. There were no differences in the inflammatory response induced by percutaneous transluminal coronary angioplasty in both groups, but the fibrinogen concentration significantly decreased during percutaneous transluminal coronary angioplasty in group 2. Decreased platelet counts and increased mean platelet volume were observed during percutaneous transluminal coronary angioplasty in both groups. The levels of prothrombin fragment 1+2 and thrombin antithrombin III complex increased markedly during percutaneous transluminal coronary angioplasty. Group 2 showed a more rapid return to the baseline levels of these two markers than group 1. Secondary fibrinolysis was evidenced by a steep increase of D-dimer after percutaneous transluminal coronary angioplasty in both groups. In contrast to the significant decrease in antithrombin activities during percutaneous transluminal coronary angioplasty in group 1, no marked change in these markers was found in group 2. Although the levels of von Willebrand factor and plasminogen activator inhibitor-1 showed essentially the same changes in both groups during and after percutaneous transluminal coronary angioplasty, more markedly increased levels of tissue type plasminogen activator and type plasminogen activator-plasminogen activator inhibitor-1 complex after percutaneous transluminal coronary angioplasty were found in group 1 than in group 2. While neither drug had any effect on the percutaneous transluminal coronary angioplasty-induced inflammatory response, argatroban may more effectively inhibit the generated thrombin and prevent antithrombin consumption during and after percutaneous transluminal coronary angioplasty.

Aged↗
PubMed2000

Bradycardia and the role of beta-blockade in the amelioration of left ventricular dysfunction.

BACKGROUND: It is clear that beta-blockers are effective for treatment of congestive heart failure, but their mechanism of action remains controversial. Hypothesized mechanisms include normalization of beta-receptor function and myocardial protection from the effects of catecholamines, possibly by the institution of bradycardia. We hypothesized that beta-blockade-induced bradycardia was an important mechanism by which these agents were effective for correction of LV dysfunction. METHODS AND RESULTS: In 2 groups of dogs with mitral regurgitation and LV dysfunction, beta-blockers were instituted. In 1 group that received beta-blockers and pacing (group beta+P), a pacemaker prevented the natural bradycardia that beta-blockers cause. In both groups, substantial LV dysfunction developed. Before beta-blockade, the end-systolic stiffness constant decreased from 3. 5+/-0.1 to 2.7+/-0.2 (P<0.01) at 3 months in group beta+P. A similar reduction occurred in the group that eventually received only beta-blockers (group betaB). In group betaB, end-systolic stiffness improved after 3 months of beta-blockade from 2.9+/-0.2 to 3.5+/-0.4 and was not different from baseline. However, in group beta+P, end-systolic stiffness failed to improve (2.7+/-0.2) after 3 months of mitral regurgitation, and was 2.9+/-0.2 at the end of the studies. The contractile function of cardiocytes isolated from the ventricles at the end of the studies confirmed these in vivo estimates of contractility. CONCLUSIONS: We conclude that institution of bradycardia is a major mechanism by which beta-blockers are effective for restoration of contractile function in a model of LV dysfunction.

Adrenergic beta-Antagonists↗
PubMed2000

Gadolinium-enhanced MR angiography in the evaluation of congenital cardiovascular disease pre- and postoperative states in infants and children.

The purpose of this study was to evaluate the utility of dynamic contrast magnetic resonance (MR) angiography under sedation for assessing congenital cardiovascular disease in infants and small children before and after cardiac surgery. In 38 patients with cardiovascular abnormalities, thoracic vasculatures were evaluated in either the preoperative (group 1; 23 patients, median age 9 months old) or the postoperative (group 2; 15 patients median age 1. 3 years old) state using gadolinium-enhanced dynamic MR angiography. Acquired data were processed with a multiprojection volume reconstruction. Image quality (grades 1-5, undiagnostic to excellent), presence or absence of the extracardiac vasculature, its pathology (group 1), and the patency of the postsurgical shunt or reconstructed vasculature (group 2) were evaluated. All images were of diagnostic image quality (mean grade 4.4-3.2). Recognition of the thoracic vasculature was correctly made in all cases (38/38, 100%). In group 1, anomalies and pathologic changes were correctly identified in 22 of 23 cases (95.7%). In one patient with dextrocardia and the cardiac type of total anomalous pulmonary venous return, the abnormality was not recognized. In group 2, the patency of the shunt flow after Glenn (n = 6), modified Fontan (n = 4), Rastelli (n = 1), and Blalock-Taussig (n = 3) operations was well demonstrated in each case. The reconstructed pulmonary artery (n = 1), veins (n = 2), and aorta (n = 1) were correctly visualized. In one case, stenosis of the reconstructed left pulmonary vein was missed by MR angiography. In 14 of 15 cases in group 2 (93.3%), MR angiography correctly gave information on the operated areas. In conclusion, dynamic contrast MR angiography under sedation is useful for evaluation of the thoracic vasculature of infants and small children in the pre- and postoperative states. J. Magn. Reson. Imaging 2000;12:1034-1042.

Aortography↗
PubMed2000

Effect of hemofiltrated whole blood pump priming on hemodynamics and respiratory function after the arterial switch operation in neonates.

BACKGROUND: Primed blood might have some deleterious effects on neonates during cardiopulmonary bypass (CPB) due to unbalanced electrolytes and inflammatory mediators. We hemofiltrated pump-primed blood before CPB to reduce inflammatory mediators and to adjust pH and the concentrations of electrolytes. The current study investigated the effects of hemofiltrated whole blood priming on hemodynamics and respiratory function after CPB in neonates. METHODS: Patients who underwent the arterial switch operation in the neonatal period for transposition of the great arteries with intact ventricular septum were chosen for this study. Seventeen patients underwent CPB with hemofiltrated blood priming (group HF) and 23 patients underwent CPB with nonhemofiltrated blood priming (group N). The concentrations of electrolytes and bradykinin and high molecular weight kininogen of the primed blood before and after hemofiltration were measured. At 4 hours after completion of CPB, the left ventricular percent fractional shortening, and the relation between the mean velocity of shortening and the end-systolic wall stress (stress velocity index), were measured by echocardiogram in 7 patients in group HF and 6 patients in group N. Alveolar--arterial oxygen tension difference (AaDO2) and respiratory index (AaDO2 divided by arterial oxygen tension) were measured at several points for 48 hours after CPB in all patients. RESULTS: Hemofiltration of the primed blood maintained electrolytes within a physiologic level and significantly reduced the concentrations of bradykinin (5,649 +/- 1,353 pg/mL versus 510 +/- 35 pg/mL, p < 0.05) and high molecular weight kininogen (52.7% +/- 3.2% versus 40.1% +/- 3.0% of normal plasma value, p < 0.05). The percent of fractional shortening at 4 hours after completion of CPB was significantly higher in group HF (n = 7) than in group N (n = 6) (22.0% +/- 0.7% versus 16.0% +/- 0.4%, p < 0.01). There was also a trend toward better stress velocity index in group HF than in group N (0.81 +/- 0.81 versus -2.17 +/- 0.45, p = 0.09). AaDO2 and respiratory index were significantly lower in group HF than in group N for 48 hours after CPB, respectively (p < 0.05). CONCLUSIONS: Hemofiltrated fresh whole blood used for CPB priming attenuated cardiac impairment at early reperfusion periods and reduced pulmonary dysfunction in neonates with transposition of the great arteries with intact ventricular septum. This therapeutic strategy may have an advantage in preventing lung and heart dysfunction in pediatric patients who need CPB priming with blood.

Cardiopulmonary Bypass↗
PubMed2000

Virus-associated haemophagocytic syndrome responsive to steroid pulse therapy and double filtration plasmapheresis.

We present an adult patient with haemophagocytic syndrome (HPS) successfully treated with a combination of steroid pulse therapy and double filtration plasmapheresis (DFPP). A 58-year-old male was admitted with high fever, severe renal dysfunction, liver dysfunction and an increased level of lactate dehydrogenase. A serological test for Epstein-Barr (EB) virus showed an elevation of EBNA-IgM antibody titre. There were increased haemophagocytic histiocytes in the bone marrow in addition to thrombocytopenia and disseminated intravascular coagulation (DIC) accompanied by organ dysfunction. EB virus associated haemophagocytic syndrome was diagnosed. On admission, interferon (IFN)-gamma, interleukin (IL)-6, IL-8, granulocyte colony-stimulating factor (G-CSF) and macrophage (M)-CSF were elevated, and were promptly normalized after steroid pulse therapy was initiated. G-CSF and M-CSF gradually decreased after DFPPs was started. To control hypercytokinaemia until treatment for the underlying disease is initiated, steroid pulse therapy and double filtration plasmapheresis are useful.

Antibodies, Viral↗