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Biomedical subjects

N Miyamoto

Publications and source records attributed to N Miyamoto.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Assessment of Japanese patients receiving heart transplants overseas].

No heart transplants have been performed in Japan due to various obstacles since the only operation performed in 1968. Since 1981, a number of patients requiring heart transplants have been accepted by foreign transplantation centers in England, the U.S.A., and Germany. This report describes an investigation of the postoperative course of these Japanese heart transplant patients and discusses the problems regarding transplantation in Japan. Of the 21 transplant patients, the diagnosis was dilated cardiomyopathy in 17, restrictive cardiomyopathy in 1, hypertrophic cardiomyopathy in 2, and congenital muscle dystrophy in 1. All patients survived surgery but three died in the long-term period. The causes of death were acute rejection (after 3 months), chronic rejection (after 50 months) and infection (after 30 months). The actuarial survival curve of these patients was 95.0% for one-year survival and 86.4% for three-year survival. The postoperative functional class was NYHA classification I in all patients (100%). Ninety-three percent of patients returned to work. Immunosuppressive therapies included triple drug therapy in 14 patients (66.7%), double drug therapy in 4 (19.0%), ciclosporin alone in 2 (9.5%) and FK506 in 2 (5.0%). The incidence of acute rejection was 1.56 episodes per patient per year within 3 months and 2.9 episodes per patient per year within 1 year. The postoperative courses of Japanese patients who underwent heart transplantation at foreign transplantation centers were satisfactory. These results will encourage heart transplantation in Japan.

Adolescent↗
PubMed1996

[Papillary muscle rupture complicating acute myocardial infarction--treatment with mitral valve replacement and coronary bypass surgery in acute phase].

Complete rupture of a papillary muscle following acute myocardial infarction is a severe complication that is typically associated with acute left ventricular failure, pulmonary edema, and relentless clinical deterioration. The reported mortality rates without surgical intervention is almost 90%, therefore, prompt operation without prolonged attempts at medical stabilization is the key to decrease operative mortality. Although the complete coronary revascularization in conjunction with mitral valve replacement is advocated in the western medical academic society, there is only a few case of conjunct surgery has been reported in Japan. Three successful cases of conjunct surgery of mitral valve replacement and coronary complete revascularization in acute phase within one week from the onset of acute myocardial infarction (AMI) are described. There were one male and two female patients with an average age of 60-year-old (range 48-67), who developed cardiogenic shock and admitted to our hospital. The average interval between onset of AMI and the appearance of mitral regurgitation (MR) was 38 hours, and that of the appearance of MR and admission was 40 hours. Surgeries were performed within 26 hours (average 13 hours) after admission. The mitral valve was replaced with a mechanical valve (St. Jude Medical Valve) and a complete coronary revasculatization was done using saphenous vein graft. The average period of operation time and aortic cross clamping time were 6 hours 22 minutes and 109 minutes respectively. The average number of coronary grafting was 2.3 (range 1-3). Postoperative recovery from cardiogenic shock was uneventful in all three patients. The average periods of ICU stay and hospital stay were 5 days and 43 days respectively. All patients have regained their social activities with mean follow up period of 52 months. Since ischemic heart disease remains the leading cause of death in such patients, it is suggested that complete coronary revascularization should be performed immediately in conjunction with valve replacement even in the acute phase after onset of AMI.

Aged↗
PubMed1996

Role of fimbriae in adherence of Streptococcus pyogenes to pharyngeal epithelial cells.

The adherence of bacteria to mucosal surface constitutes the initial, critical step in colonization and infection. Streptococcus Pyogenes (S. pyogenes) is one of the most important bacteria in tonsillitis and pharyngitis. The mode of the adherence of S. pyogenes to pharyngeal epithelial cells and the morphology of S. pyogenes were observed by scanning electron microscopy and transmission electron microscopy. The adherence of S pyogenes to pharyngeal epithelial cells was mediated by the fimbriae radiating from the surface of the bacteria. The M protein-negative (M-) strain had smooth, bare cell walls, whereas the M protein-positive (M+) strain had an exterior covered by hair-like fimbriae.

Epithelium↗
PubMed1996

Recent trends in clinical isolates from paranasal sinusitis.

Trends in the detection of causative pathogens and changes in bacterial counts in patients with sinusitis treated between January 1989 and December 1993 were investigated. In adult patients with chronic sinusitis, Staphylococcus aureus (S. aureus), coagulase negative staphylococci (CNS), Streptococcus pneumoniae (S. pneumoniae), Corynebacterium sp., Haemophilus influenzae (H. influenzae), and Moraxella catarrhalis were often isolated while Pseudomonas aeruginosa (P. aeruginosa) and anaerobic bacteria were detected in 2.4% and 5.3% of patients, respectively. The bacteria isolated from adult patients with acute sinusitis and pediatric patients with either acute or chronic sinusitis were somewhat different from those of adult chronic sinusitis. No bacteria could be isolated from 5.8% of adult chronic sinusitis patients, 8.1% of adult acute sinusitis patients, and 3.1% of pediatric sinusitis patients. The detection rate for anaerobic bacteria has been rising in chronic sinusitis patients owing to improved detection techniques in recent years, while there has been no appreciable change in the isolation rate for other types of bacteria. When the pathogenicity of isolated bacteria was determined based on the amount of bacterial colonization it was found that P. aeruginosa, S. pneumoniae, H. influenzae, and S. aureus were significant as causative pathogens in sinusitis, while CNS.

Chronic Disease↗
PubMed1996

Inhibitory effect of roxithromycin on biofilm formation of Pseudomonas aeruginosa.

Biofilm formed by bacteria has recently has been shown to be involved in making infectious diseases intractable. We indirectly measured and evaluated the inhibitory effect of roxithromycin (RXM) on biofilm formation on the inside of a plastic test tube by determining the number of living bacteria in the biofilm. As a result, RXM was found to inhibit biofilm formation even though it does not have antimicrobial activity against Pseudomonas aeruginosa. In addition, this inhibitory effect on biofilm formation was observed at in vivo concentrations which are possible in clinical use of RXM. Thus, there is a possibility that RXM is effective against infectious otolaryngological diseases when biofilm formation is likely to be pathologically involved, even if the detected bacteria are not sensitive to the drug.

Anti-Bacterial Agents↗
PubMed1996

Transitional concentration of antibacterial agent to the maxillary sinus via a nebuliser.

Surface and tissue transitional concentration of 3% FOM aerosol for treatment of paranasal sinusitis was examined in 18 patients (21 sides) who underwent the Caldwell-Luc operation. In this operation, patients have a bony window on the sinus; we therefore investigated the difference of compliance of the maxillary sinus between when we closed the bony window with subcutaneous tissue and when we did it with a silicone sheet before the FOM nebulization. No significance was found in the mean concentration of FOM either at the maxillary sinus surface or in the tissue with or without the use of the silicone sheet. We also examined the concentration using a jet-type nebulizer and an ultra-sonic type nebulizer. Using the ultrasonic-type nebulizer resulted in a higher transitional concentration at two sites of the maxillary sinus surface than when using the jet-type nebulizer. The results suggest that the ultrasonic-type nebulizer is more effective in the treatment of paranasal sinusitis than the jet-type, and that there was no change of maxillary sinus compliance with or without a bony window.

Anti-Bacterial Agents↗
PubMed1996

Final report of a randomized controlled study with streptococcal preparation OK-432 as a supplementary immunopotentiator for laryngeal cancer.

We conducted a randomized controlled study of streptococcal preparation OK-432 on 120 newly identified cases of laryngeal squamous cell carcinoma who were registered at 10 participating institutions between November 1984 and October 1989. The patients were divided into two groups: those in early stages (stage I or II) and those in advanced stages (stage III or IV); these groups were further subdivided into an immunotherapy group (receiving OK-432) and a control group (who did not receive OK-432). The usefulness of OK-432 was studied using the sealed envelope method. The basic therapy for all cases was radiotherapy and, when required, surgery. As adjuvant therapy, 5Fu or derivatives were administered to all cases from the beginning of the treatment period to one year after the basic therapy, with the exception of cases in whom side effects were serious enough to contraindicate use of the drug. The target administration period was 5 years. Of the initial 120 cases, 11 cases were disqualified (3 cases of double cancer and 8 of incomplete primary therapy) and the remaining 109 were used for evaluation. The 5-year survival rate and the 5-year recurrence-free rate were 76% and 84%, respectively, in the immunized groups (both the early and advanced groups), whereas the same rates for the control groups were 78% and 75%. There was a tendency for the immunized groups to enjoy a slightly longer recurrence-free period. Over a 24-month observation period the immunized group always had higher levels of peripheral leukocytes and peripheral lymphocytes; this difference was significant for the first 21 months. Inhibition of bone marrow function is sometimes observed with radiotherapy. It is hoped that, if this inhibition can be mitigated, it will be possible to assist the compromised immune system and maintain a certain level of immune performance which will prevent recurrence and improve survival rate. In the present study we observed a tendency of the lower recurrence rate in the immunized group, and we hypothesize that OK-432 is effective in extending the recurrence-free period.

Antineoplastic Agents↗
PubMed1995

On the potential of the Wilson central terminal with respect to an ideal reference for unipolar electrocardiography.

Body surface potential mapping was performed in 60 clinical cases and an ideal 0 potential was calculated in each case at 2msec intervals, which corresponds to the potential at infinity. Maximal deviation of the Wilson terminal voltage the ideal potential was 0.14mv on the average. Time course of potential variations of the central terminal was in proportion to the measured surface potentials. The lead vector of Wilson terminal was determined for each case, with a method to make a minimal difference between calculate and observed Wilson terminal voltage. The lead vector was directed superiorly and posteriorly with the magnitude of 24% of that of lead I on the average.

Body Surface Potential Mapping↗
PubMed1995

[Relationship between chilliness of the limbs and daily-life conditions in young females].

In winter, many people have trouble with chilliness in their arms and legs. Many women are especially sensitive to cold, and for them the chilliness of the hands and the feet is difficult to ease even after entering a warm room, or taking a bath. They even feel pain owing to coldness of their limbs in daily life. This symptom has been called "hiesho" in Japanese. The problem of this chilliness is difficult to study because this symptom, in general, can be cured when spring comes. Coldness of the limbs has been considered to be one of the symptoms of the climacteric disturbance among middle-aged females. Recently, however, it was reported that many young females also feel pain owing to coldness of the hands and legs in their daily life during winter. This study investigates the problems of chilliness in the limbs of young females in their daily life. By means of a questionnaire, 642 female college students aged from 18 to 20 years answered questions concerning: (1) physical characteristics, (2) physical conditions in their daily life, (3) physical conditions in winter, and (4) physical conditions in summer. The replies to the questionnaires were tested using the chi 2 test. The major results were as follows: 1. Half of the subjects were sensitive to cold, and had difficulty sleeping owing to chilliness of their limbs in winter even in a warm environment. For the following results the subjects who were sensitive to cold had significant differences (p < 0.05) compared to non-sensitive subjects to cold.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1995

Mechanism of cytosine arabinoside toxicity to the blast cells of acute myeloblastic leukemia: involvement of free radicals.

Retinoic acid and hydrocortisone (HC) have been shown to regulate the drug sensitivity of the blast cells of acute myeloblastic leukemia (AML). We asked if the proto-oncogene bcl-2 played a role in this regulation. As target cells we used the continuous lines, OCI/AML-1, OCI/AML-2 or OCI/AML-5; expression of bcl-2 can be detected by Northern analysis of RNA from OCI/AML-2 or OCI/AML-5 cells; bcl-2 expression can be found in OCI/AML-1 cells only by using RT-PCR. Exposure of OCI/AML-2 or OCI/AML-5 cells to retinoic acid (all-trans retinoic acid, ATRA) led to a down-regulation of bcl-2 expression that was first seen after 2 h of exposure and was complete after a day. The down-regulation could be prevented by exposing the cells to ara-C either before or after ATRA; decrease in bcl-2 protein was moderate and only obvious after 36 h of ATRA treatment. Nuclear run-on experiments provided evidence that bcl-2 down-regulation was occurring at transcriptional and post-translational levels. Since bcl-2 is considered to have anti-oxidant activity, we tested the sensitivity of the three cell lines to H2O2; we found that OCI/AML-1, the line with very low bcl-2 expression, was a 100-fold more H2O2-sensitive than OCI/AML-2 or OCI/AML-5, where bcl-2 expression can be detected readily. We then asked if H2O2 sensitivity could be regulated. We found that exposure of cells to HC before H2O2 was protective while ATRA after peroxide treatment increased killing; this is the same pattern of regulation observed when AML blasts are exposed to HC before, or ATRA after ara-C. Finally, we asked whether N-acetylcysteine (NAC), a known radical scavenger would protect cells against ara-C killing. Significant protection was observed when NAC was given before drug, but not if given after drug. NAC protection against ara-C killing was seen for OCI/AML-1 and 2 cells, but not for OCI/AML-5 cells. We interpret the results as follows: ara-C kills cells in two ways: first, directly, by incorporation into DNA and chain termination; second, indirectly, by inducing the production of toxic radicals. Bcl-2 reduces the oxidant activity of such radicals, and is protective. ATRA regulates ara-C toxicity by its action on bcl-2. Left unexplained are the action of HC, which does not affect bcl-2 expression and the mechanism by which ara-C prevents down-regulation of bcl-2 by ATRA.

Acetylcysteine↗
PubMed1995

[Usefulness of intracardiac echocardiography for guidance of transseptal puncture procedure].

The clinical usefulness of intracardiac echocardiography (ICE) for the guidance of transseptal puncture procedure during percutaneous left heart bypass support (PLHBS) and percutaneous transvenous mitral commissurotomy (PTMC) was investigated to replace intraoperative transesophageal echocardiography monitoring which requires mild sedation and causes patient discomfort. The ICE procedure was assessed in 3 patients with PLHBS and 18 with PTMC using a 10 MHz rotating 8 French probe system especially developed for the purpose. Transseptal puncture procedure was observed by intraoperative ICE monitoring in the right atrium. The ICE images showed the transseptal puncture (Brokenbrough) needle as a point casting an acoustic shadow. By moving the ICE probe up and down, the excursion of the needle and its approach to the septal wall could be clearly observed. If the puncture needle is forced into the intra-atrial septum, the septal wall was clearly observed to protrude into the left atrium (tent-formation). In a tent-formation the puncture site could be determined by ICE alone. Intracardiac echocardiography guidance was useful and may improve the safety and reliability of the transseptal puncture procedure in PLHBS and PTMC.

Adult↗
PubMed1994

[A case of traumatic intrapulmonary foreign body].

A case of 60-year-old man with traumatic intrapulmonary foreign body that was not inhaled, but through the chest wall was described. In July 1992 a grass cutter was working in a forestry with a circular saw when he was struck into the right lung. He had a sharp pain in the anterior chest. No abnormality was seen in front of his neck and the chest wall. The next month he developed a cough with bloody sputum. The chest X-ray showed a metallic foreign body at the right side of manubrium. Computed tomogram showed a steel wire fragment lodging beside the innominate artery and vein and in the right lung. Median sternotomy was performed and a foreign body was successfully removed with partial resection of upper lobe.

Foreign Bodies↗