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H Mizuhara

Publications and source records attributed to H Mizuhara.

At least 19 recordsLinked to original sources
PubMed1992

Type II collagen-induced murine arthritis: induction of arthritis depends on antigen-presenting cell function as well as susceptibility of host to an anticollagen immune response.

Two sets of ((resistant x susceptible) F1----parent) and (parent----F1) chimeric mice were prepared. In the chimeric combinations involving BALB/c and DBA/1 mice, all (F1----F1) chimeras developed arthritis as well as potent anticollagen responses after immunization with collagen, whereas all (F1----BALB/c) and (BALB/c----F1) chimeras induced neither arthritis nor immune responses. This type of F1 T cells could be activated with APC from DBA/1 but not from BALB/c mice. Thus, the failure of the [F1 in equilibrium with BALB/c] chimeras to mount anticollagen responses was due to a defect at the APC level. Another arthritis-resistant strain, C57BL/6, exhibited adequate APC function, but reduced T cell responsiveness, representing an intermediate responder. In the chimeric combinations involving C57BL/6 and DBA/1 mice, (F1----F1) and (C57BL/6----C57BL/6) chimeras developed very high and very low incidence of arthritis, respectively. (C57BL/6----F1) chimeras developed an appreciable incidence of arthritis under conditions in which this group of chimeras generated intermediate levels of anticollagen responses. In contrast, (F1----C57BL/6) chimeras developed low incidence of disease despite induction of strong responses. Moreover, cells from collagen-immunized (F1----C57BL/6) chimeras, when transferred into T cell-depleted B cell mice of F1 or C57BL/6 strain, produced comparable immune responses in both groups but induced much more severe arthritis in F1 than in C57BL/6 recipients. These results indicate that: i) two types of arthritis-resistant strains can be identified, each of which has anticollagen APC defect as a low responder and reduced T cell responsiveness as an intermediate responder and ii) a discrepancy between the degree of anticollagen responses and clinical arthritis is attributed to the differential susceptibility to anticollagen immune responses.

Animals↗
PubMed1992

[Postoperative management in neonate after open cardiac surgery].

Recent advances in diagnostic method and preoperative care have allowed us to perform surgical repair in neonate. Important to the successful outcome of open cardiac surgery in neonate is cautious management in postoperative period. So we investigated the hemodynamics in the first 72 hours following open heart surgery for TAPVC, TGA and PAIVS. The hemodynamics in acute period are different according to patient age. Especially, early neonates under 14 days present low systemic blood pressure and high central venous pressure. So we must manage them according to their hemodynamic characteristics.

Blood Pressure↗
PubMed1992

[An experience of rapid, two-stage arterial switch operation for transposition of the great arteries and intact ventricular septum beyond the neonatal period].

A 2-month-old girl with transposition of the great arteries and intact ventricular septum was successfully repaired by rapid, two-stage arterial switch operation. Balloon atrioseptostomy and ligation of the ductus arteriosus was done elsewhere on 14th and 29th day after birth. On her first admission to our hospital at 2 months of age, left ventricular-right ventricular pressure ratio (LVp/RVp) was almost 0.5 and left ventricular posterior wall thickness (LVPWT) by echo cardiography was 3.5 mm. Because of these date, we selected rapid, two-stage arterial switch operation. On 74 days, the first-stage preparatory operation (pulmonary arterial banding and right modified Blalock-Taussig shunt) was undergone with the resultant LVp/RVp of 0.97. During a few days after the first-stage operation, left ventricular ejection fraction (LVEF) by echocardiography was reduced to nearly 30%. But after this phase left ventricular function recovered rapidly and LVp/RVp, LVPWT and LVEF was 1.18, 6.3 mm and 66% on the 7th day. On the 9th day, the second-stage arterial switch operation was undergone as usual as in neonatal period without hard adhesion. Her postoperative course was uneventful.

Cardiac Surgical Procedures↗
PubMed1992

[Fundamental study on levofloxacin in the field of obstetrics and gynecology].

We performed a fundamental study on levofloxacin (LVFX, DR-3355), a new synthetic antimicrobial agent, in the field of obstetrics and gynecology. Concentrations in serum and intrapelvic genital organs (various regions in the uterus, ovary and oviduct) were determined following single oral administration. The transport of LVFX into genital tissues was found to be good, with the tissue levels of 0.64-2.13 micrograms/g after oral administration of 100 mg and 0.77-4.86 micrograms/g after administration of 200 mg. These tissue levels of LVFX were higher than those in serum and exceeded the MIC90 values against most causative organisms isolated from the lesions of obstetric and gynecological infections. These data indicate that LVFX should be useful in the field of obstetrics and gynecology.

Administration, Oral↗
PubMed1991

[Absent pulmonary valve syndrome: surgical approach for the worst group included in symptomatic neonates].

Absent pulmonary valve syndrome (APVS) has been classified to two groups. One is severely symptomatic infant group and the other no or slightly symptomatic. But we think that severely symptomatic group should be divided into the worst neonate group and the other. This worst group, that contains neonates who can not be weaned from the respirator after surgical intervention including corrective surgery because of severe bronchomalacia and/or peripheral bronchial stenosis, has already severe respiratory distress and needs ventilatory support while high pulmonary vascular resistance is maintained. Three patients of this group were operated on at 2, 13 and 2 days of age and there were two late hospital death. The last patient underwent ligation of main pulmonary artery (mPA) and left modified Blalock-Taussig shunt (MBTS) with phi 4 mm polytetrafluoroethylene graft and was extubated on the next day. The management of this group should aim at controlling the pulmonary regurgitation as early as possible to decrease the progressive airway obstruction and minimize pulmonary tissue damage. Ligation of mPA and MBTS can be performed without cardiopulmonary bypass and eliminates pulmonary regurgitation and controls the pulmonary blood flow less than the total correction. In the point of protecting bronchi and lung and reducing the risk of surgical intervention in critical neonatal period, ligation of mPA and MBTS can be safer and more effective operation for the worst APVS neonate than the total correction with insertion of artificial valve.

Blood Vessel Prosthesis↗
PubMed1990

[Successful treatment by using a pedicled omental flap for mediastinal infection in the presence of a external valved conduit].

Mediastinal infection is one of serve and fatal complications after cardiac surgery, especially in the presence of an artificial graft. A case of successful treatment by using a pedicled omental flap for mediastinal infection in the presence of an external valved conduit is reported. a 10-year-old girl who had implanted the 12 mm porcine valved conduit for truncus arteriosus at age 9 months, underwent replacement of the old conduit with a 18 mm valved conduit. On the 9th postoperative day, as soon as mediastinal infection was proved by positive culture of the drainage from the chest tube, a reoperation was performed to debride and irrigate the mediastinum. Irrigation with povidone-iodine and antibiotics was continued for 3 weeks until improvement of CRP levels and negative drainage cultures. Then the heart and the valved conduit were wrapped with the pedicled omental flap and the skin was closed. She was without any evidence of infection for 3 months after operation. Use of a pedicled omental flap might be an effective method for treatment of mediastinal infection in the presence of an external conduit.

Blood Vessel Prosthesis↗
PubMed1990

[Delayed midsternal wound reconstruction for infants without secondary sternal closure].

Three infants, aged 11 days, 19 days and 48 days, underwent two Jatene operations and one modified Norwood operation. The sternum was left open and the skin defect was covered with a silicon sheet in all three patients. Delayed sternal closure was impossible because of hemodynamic deterioration in all three patients. Consequently delayed midsternal wound reconstruction was applied. One rectus abdominis muscle flap was turned up and the defect between the split sternum was filled with this muscle flap. Bilateral axillary incision was made to decrease the skin tension and the midsternal wound was closed with cutaneous advancement flaps. Bilateral axillary defects were covered with mesh skin implantation. All three patients recovered after this procedure. We propose this technique for the cases in which the delayed sternal closure is impossible.

Abdominal Muscles↗
PubMed1990

[Right ventricular outflow tract reconstruction in two neonates with pulmonary atresia and intact ventricular septum].

Two neonates, aged 8 and 18 days, with pulmonary atresia and intact ventricular septum underwent right ventricular outflow tract reconstruction with an autologous pericardial transannular patch. Preoperative cardiac catheterization revealed a tripartite right ventricular morphology with suprasystemic right ventricular morphology with suprasystemic right ventricular systolic pressure (right ventricular to left ventricular peak pressure ratio was 1.2 in case 1 and 2.0 in case 2). Right ventricular volume was 73.5% of normal and 115% of normal respectively. Generous resection of the infundibular myocardium was done and a patch was inserted with the heart kept beating as the perfusate temperature of 32 degrees C. In case 1 a modified Blalock-Taussig shunt was added on the postoperative day 21, because of the insufficient growth of the right ventricle, but in case 2 prostaglandin E1 could be discontinued on the postoperative day 9.

Female↗
PubMed1990

[Clinical experience of adjustable pulmonary artery banding].

Pulmonary artery banding has been a useful palliative procedure for infants with congenital cardiac anomalies associated with excessive pulmonary blood flow. We have experienced some cases that the band was not sufficient enough to reduce the pulmonary artery pressure in complex cardiac anomalies. Therefore, we developed a new adjustable pulmonary artery banding system which can be re-adjusted extrathoracically without reoperation. We used this system in seven infants with congenital cardiac lesions and obtained good results.

Heart Defects, Congenital↗
PubMed1989

[Axillary vertical incision thoracotomy sparing pectoralis major muscle and latissimus dorsi muscle: an approach for patent ductus arteriosus].

The technique of an axillary vertical incision thoracotomy sparing pectoralis major muscle and latissimus dorsi muscle for a closure of patent ductus arteriosus is presented. After an mid-axillary vertical incision, serratus anterior muscle is incised on the third intercostal space between pectoralis major muscle and latissimus dorsi muscle. The space between serratus anterior muscle and rib cage (Spatium intermusc. thoracale) is dissected with a finger, through this space the 3rd intercostal thoracotomy is performed in the axillary and dorsal portion. The ventral part of intercostal muscle is incised from inside of the thoracic cavity for sparing the pectoralis major muscle. We performed this technique in two patients aged 1 year, and secured equally good operative fields as could be secured by the original axillary vertical incision thoracotomy described by Browne.

Axilla↗
PubMed1977

[Diphtheria].

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Child↗