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Biomedical subjects

Yasuo Ono

Publications and source records attributed to Yasuo Ono.

34 records · Page 2Linked to original sources
PubMed2003

Stent implantation and subsequent dilatation for pulmonary vein stenosis in pediatric patients: maximizing effectiveness.

The outcome of stent implantation and redilatation was investigated in 4 pediatric patients with 7 stenotic lesions of the pulmonary vein (PV), paying particular attention to late neointimal proliferation. The minimal diameter of the lesions increased from 0.8-3.6 (2.3+/-1.1) mm to 3.6-8.4 (5.1+/-1.6) mm immediately after stent implantation. Although the pressure gradient across the lesion was not measured in patient 4, in patients 1-3, it decreased from 4-34 (18+/-13) mmHg to 3-15 (7+/-4) mmHg. Except for case 4, who achieved a lesion diameter of 8.4 mm after initial stent dilatation, the other 6 lesions all restenosed within a few months, with an increasing pressure gradient. One patient with multiple PV stenoses associated with persistent severe pulmonary hypertension died suddenly. However, repeat dilatations were effective in all other lesions. Furthermore, in one lesion in patient 1, no serious restenosis developed for 20 months after the lesion was dilated up to 5.6 mm. Although further follow-up is mandatory, the final stent diameter within a vessel may determine long-term patency, and aggressive redilatation may be crucial for successful therapy of such a difficult disease.

Angiography↗
PubMed2003

Intravenous indomethacin therapy in infants with a patent ductus arteriosus complicating other congenital heart defects.

In the present study, 0.2-0.6 mg/kg (0.4+/-0.2, mean +/- standard deviation) indomethacin was administered intravenously to close a patent ductus arteriosus in 13 infants with co-existing congenital heart defects whose ages ranged from 3 to 48 (14+/-14) days. All of them were hemodynamically ductus-independent and symptomatic. Echocardiography demonstrated that the ductus had closed in 8 infants, aged 3-33 (12+/-10) days (responders), but had not closed in 5 infants aged 6-48 (19 +/-19) days (non-responders). There was no significant difference between the responders and non-responders in their age, body weight, minimal diameter of the duct, dose of indomethacin, gestational age, birthweight, or Apgar score. One possible major complication might be associated with indomethacin. However, intravenous indomethacin should be considered prior to surgical ligation as one option for infants with a symptomatic patent ductus arteriosus complicated by other congenital heart defects.

Cardiovascular Agents↗
PubMed2003

[Prophylactic efficacy of a basidiomycetes preparation AHCC against lethal Candida albicans infection in experimental granulocytopenic mice].

The prophylactic effects of a Basidiomycetes preparation, AHCC, against lethal Candida albicans infection were investigated in non treated or immunosuppressed mice. In the cyclophosphamide-or 5-fluorouracil (5-FU)-treated leukopenic mice and nontreated mice, the intraperitoneal administration of AHCC prior to C. albicans infection clearly prolonged the survival periods of the infected mice. In doxorubicin-treated mice, AHCC was less but significantly effective. On the other hand, in prednisolone-treated mice, AHCC was not effective. Oral administration of AHCC also protected the 5-FU-treated mice from lethal Candida infection, as indicated by prolongation of the survival periods and inhibition of Candida growth in the kidneys of these mice and by the increase in a number of neutrophils in their peripheral blood. These results suggested that AHCC may display a protective role against opportunistic fungal infection in leukopenic hosts.

Adjuvants, Immunologic↗
PubMed2003

Visualization of interscapular brown adipose tissue using (99m)Tc-tetrofosmin in pediatric patients.

UNLABELLED: Brown adipose tissue (BAT) is a site of nonshivering thermogenesis in mammals. The mitochondria of BAT operate in an uncoupled mode and increase fatty acid oxidation to produce heat at birth. Thus, the BAT of human infants and children contains more active mitochondria than that of adults. We surmised that because (99m)Tc-tetrofosmin can be absorbed by functional mitochondria in the myocardium and in tumor cells, it could reveal mitochondrial function in BAT. METHODS: Between January 1999 and December 2002, we retrospectively analyzed 385 consecutive studies of (99m)Tc-tetrofosmin uptake in pediatric patients with cardiac disorders. All patients with symmetric (99m)Tc-tetrofosmin accumulation within the neck and shoulder region according to planar images were selected, and the features of the uptake were analyzed. RESULTS: Increased symmetric (99m)Tc-tetrofosmin uptake in the interscapular BAT was a typical profile of 65 of the 385 patients (17%). The frequency of (99m)Tc-tetrofosmin uptake was significantly higher in winter than in spring or summer (P < 0.05) and prominent in newborns. The frequency peaked between 0 and 2 y of age and then declined with age. CONCLUSION: Gamma-camera imaging with (99m)Tc-tetrofosmin can reveal interscapular BAT distribution in infants and children in terms of mitochondrial activity.

Adipose Tissue, Brown↗
PubMed2003

Acute recoil of stents used for the relief of stenotic great vessels in the setting of congenital cardiac disease.

We implanted either large or medium Palmaz stents, or a Palmaz Corinthian stent, in various stenotic vessels, such as the pulmonary arteries, pulmonary veins, aorta, or superior caval vein. Using angiograms, we measured the diameter of the stenotic vessel before or after the implantation, the minimal diameter of the lumen, the minimal diameter of the largest fully expanded balloon used to expand the stent, and the diameter immediately after withdrawal of the balloon. The minimal diameter of the fully expanded balloon, and the minimal diameter of the lumen subsequent to expansion, were 8.2 +/- 2.4, and 7.7 +/- 2.3 mm, giving an absolute recoil of 0.5 +/- 0.4 mm, and a proportional recoil of 7 +/- 4%. There was no significant difference in either the absolute or proportional recoil for any of the stents, or for any of the different stenotic vessels. The proportional recoil correlated linearly with the minimal diameter of the lumen prior to the procedure, and with the ratio of the stenosis to the balloon, while the diameter of the stenotic vessels, the minimal diameter of the largest fully expanded balloon, the proportional stenosis prior to the procedure, and the ratio of the balloon to the diameter of the stenotic vessel, had no significant correlation with proportional recoil. The proportional recoil exceeded more than one-tenth when the minimal diameter of the lumen prior to the dilation was less than 3 mm, or the ratio of the balloon to the stenosis was greater than 3.0. An absolute recoil of around 1 mm is common when a large or medium Palmaz, or a Palmaz Corinthian stent, is implanted in great vessels. Balloons with a diameter of approximately one-tenth greater than that of the adjacent vessel may be needed if the minimal diameter of the lumen is small prior to the procedure.

Acute Disease↗
PubMed2003

[Basic and clinical evaluation of the new rapid diagnostic kit for detecting group A streptococci with the immunochromatographical method].

Basic and clinical performance of a new diagnostic kit that detects Group A Streptococci by an immunochromatographical method, QuickVue Dipstick Strep A (Quidel Corporation; San Diego, CA) were evaluated. In basic specificity study, the QuickVue Dipstick Strep A showed positive reaction only to group A Streptococci strains among 34 strains of 10 species of bacteria. In detection limit study, the QuickVue Dipstick Strep A had a capacity to detect Group A Streptococci in 1.0 x 10(4); cfu/ml (1.0 x 10(3) cfu/test). This sensitivity was about 6 times higher than that of the existing similar immunochromatographical test, STREP A TESTPACK Plus (TESTPACK, Abbott Japan, Tokyo). In clinical study compared with bacterial culture test using 100 patients' throat swab specimens, the QuickVue Dipstick Strep A showed a sensitivity of 94.4% (34/36), a specificity of 100% (64/64) and an accuracy of 98% (98/100). Furthermore in correlation study with the reference test, TESTPACK, the QuickVue Dipstick Strep A showed 100% agreement (34 positive and 66 negative specimens). As the QuickVue Dipstick Strep A has several advantages as not only simple operation, rapid reaction and good performance but also easy storage (under room temperature), compact size and minimum waste products, we conclude that this new test is useful as Point-of-Care Testing kit and plays a peripheral role in the diagnosis of Group A Streptococci infection and pertinent medical treatment by antibacterial agents.

Humans↗
PubMed2002

Potential goals for the dimensions of the pulmonary arteries and aorta with stenting after the Fontan operation.

The purpose of this study was to clarify desired stent sizes for stenotic lesions in the post-Fontan circulation. Using angiograms from 22 patients before and at late follow-up (> or = 15 years) after the Fontan operation, we measured the maximum diameters of the proximal pulmonary arteries (PA) and the descending aorta. The diameters of the PA ipsilateral to the inferior vena cava, contralateral to the inferior vena cava, and descending aorta after the Fontan were 10.6-22.6 (15.8 +/- 3.3), 8.0-19.1 (12.9 +/- 3.1), and 12.1-18.9 (15.8 +/- 2.0) mm, respectively, while the percent of normal predicted diameters (% N) were 55%-104% (70% +/- 14%), 38%-99% (66% +/- 17%), and 46%-74% (60% +/- 7%), respectively. Despite somatic growth, the % N of all vessel diameters decreased significantly after the Fontan operation. In conclusion, smaller-sized stents should be acceptable for both the pulmonary artery and descending aorta in the Fontan circulation.

Adolescent↗
PubMed2002

Destructive pulmonary embolism in a patient with community-acquired staphylococcal bacteremia.

We report a 17-year-old man with destructive pulmonary embolism caused by Staphylococcus aureus bacteremia. The patient was not immunocompromised and had neither underlying diseases nor risk factors, such as concomitant influenza viral infection, which exacerbate staphylococcal infections. The rapid and extensive progression of pulmonary involvement in all lung fields make this a rare case; there have been few reports in the literature describing a similar radiographic appearance in patients with community-acquired staphylococcal bacteremia. In-vitro studies did not demonstrate the production of enterotoxins or toxic shock syndrome toxin 1 (TSST-1) by the isolated strain, but genetic analysis detected Panton-Valentine leukocidine gene from the strain. Subsequent empyema with bilateral pneumothorax was prolonged because of superinfection with both methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Optional surgical treatments, including thoracostomy and thoracopneumoplasty, finally improved his condition.

Adolescent↗
PubMed2002

Late neointimal proliferation following implantation of stents for relief of pulmonary arterial stenosis.

On the assumption that the diameter of the reference vessel might determine the thickness of neointimal coverage of stents placed in the pulmonary arteries, we analyzed the angiograms of 28 lesions in 17 patients who underwent follow-up cardiac catheterization. Excluding 2 lesions where late stenosis was determined mainly by recoil of greater than 30%, we investigated the neointimal thickness of 26 lesions in 16 patients. Several factors that might contribute to late re-stenosis were also analyzed. Age and body weight at implantation ranged from 0.8 to 20 years, with a median of 6 years, and from 6.8 to 77.5 kg, with a median of 17.6 kg. Follow-up interval was from 6 to 15 months, with a median of 6 months. There was a significant increase in diameter, as well as a reduction in pressure gradient, immediately after the implantation of stents. Although there was no significant difference between the achieved diameter and the diameter of the stent at follow-up, the diameter of the lesion at follow-up was significantly smaller than the diameter achieved by stenting. The increase in the pressure gradient at follow-up was slightly greater in 4 lesions where the late reduction in diameter was greater than 30% than in the 18 lesions where this was less than 30% (p = 0.05). The diameter of the reference vessel, and the diameter by stenting correlated with the late reduction in diameter. All lesions with diameter reduced greater than 30% had a reference diameter of less than 6.1 mm, and a diameter achieved by stenting of less than 6.5 mm. Late loss in luminal diameter directly correlated with the thickness of the neointimal coverage. In conclusion, close observation should be mandatory following implantation of stents in small pulmonary arteries.

Adolescent↗
PubMed2002

Modulation of oxidative burst of neutrophils by doxycycline in patients with acute myocardial infarction.

We investigated to what extent doxycycline hydrochloride (DOXY) can modify polymorphonuclear leucocyte (PMN) activity in patients with acute myocardial infarction (AMI). PMN activity was measured in blood samples obtained at 0, 15, 30 and 60 min after DOXY administration. In patients receiving saline, PMN activity did not change over 60 min. In contrast, patients receiving DOXY showed a > or = 10% reduction in PMN activity at 30 and 60 min. These data support the use of DOXY to reduce myocardial cell damage by PMNs in patients with AMI.

Aged↗
PubMed2002

Protection of mice from lethal endogenous Candida albicans infection by immunization with Candida membrane antigen.

The protective effects of immunization with Candida membrane antigen (CMA) on a systemic infection originating from intestinally colonized Candida albicans were examined. The colonization of orally inoculated C. albicans in the intestinal tract was established in BALB/c mice that had been concomitantly treated with oral doses of antibacterial drugs. In these animals, a systemic dissemination of C. albicans with fatal outcome was induced by a repeated dosing of prednisolone. In this endogenous infection model, the effects of immunization by CMA on the infection were examined. CMA-immunized mice showed a longer lifespan than unimmunized mice. The protective effect of CMA immunization in immunosuppressed mice was also measured by a decrease in body weight loss after treatment with prednisolone and in the number of viable Candida cells in the target organs, the kidneys and livers. However, the CFU of C. albicans in the intestinal tract was not significantly lowered. These results suggest that CMA immunization inhibited the dissemination of systemic Candida infection from the intestinal tract induced by treatment with prednisolone.

Animals↗
PubMed2002

Factors determining peripheral pulmonary artery stenosis remodeling in children after percutaneous transluminal balloon angioplasty.

The peripheral pulmonary artery stenosis (PPS) that complicates congenital heart anomalies can improve after percutaneous transluminal balloon angioplasty (PTA), despite an initial poor response, but there is little information concerning the factors that determine such remodeling. The present study reviewed the hemodynamic and angiographic data before, immediately after, and at late follow-up after PTA for 17 lesions in 14 patients. Lesions were classified into either the (+) group (with pulmonary artery remodeling) or the (-) group (without remodeling). Remodeling was defined as an increase of more than 30% in the predictive percent of normal (%N) of the peripheral pulmonary artery diameter at late follow-up compared with the diameter immediately after PTA. Remodeling occurred in 6 of 17 lesions (35%), and the pressure gradient immediately after PTA was significantly smaller (<10 mmHg) in the (+) group than in the (-) group. Late expansion of the lesion (remodeling) occurs after PTA in some children with PPS and an adequate initial reduction in the pressure gradient favors subsequent remodeling.

Angioplasty, Balloon, Coronary↗
PubMed2002

[Pseudomonas aeruginosa].

Moisture is a critical factor in hospital reservoirs of Pseudomonas aeruginosa, such as respiratory equipment, medicines, disinfectants, sinks, mops, food and vegetables. P. aeruginosa, a nosocomial pathogen, is an important cause of infection in immunosuppressed patients, particularly those with neutropenia, burn, cancer, chronic lung disease, diabetes mellitus, immunosuppression, surgery, advanced age; presence of a foreign body, prosthesis, or instrumentation; prolonged hospitalization and antibiotic use. Most common infections include pneumonia, urinary tract infections, skin infections and bacteremia. Resistance of P. aeruginosa in vitro to many antibiotics is widespread and increasing in frequency. For hospital infection control, appropriate sterilization of all equipment, hand washing after patient examination, avoiding unnecessary antibiotics use and contact isolation for multiple resistant P. aeruginosa should be performed.

Bacterial Adhesion↗