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Biomedical subjects

H Kitayama

Publications and source records attributed to H Kitayama.

86 records · Page 5Linked to original sources
PubMed1986

Three distinct activities possibly involved in mRNA splicing are found in a nuclear fraction lacking U1 and U2 RNA.

A nuclear extract from HeLa cells was fractionated by DEAE-Sepharose chromatography, and the fractions were assayed for the binding activity for a small RNA transcript carrying a splice junction or branch point sequence. The binding activity for the RNA carrying a 5' splice junction was localized in the small nuclear ribonucleoprotein (snRNP) fraction together with binding activity for the RNA carrying a 3' splice junction or branch point sequence. However, stronger binding activities for the 3' splice junction RNA and for the branch point RNA were discovered in the flow-through fraction where no small nuclear RNA were detected. When the flow-through fraction was added to purified U1 ribonucleoprotein, the binding activity for the 5' splice junction RNA was markedly enhanced. We propose that the factors responsible for the three types of activities found in the flow-through fraction play a role in the splicing of mRNA precursor.

Adenosine Triphosphate↗
PubMedDate not supplied

Thromboembolic pulmonary hypertension due to disseminated fibromuscular dysplasia.

We present two patients with thromboembolic pulmonary hypertension associated with unusual complications probably caused by disseminated fibromuscular dysplasia (FMD) or FMD-like vascular lesions. Intimal fibroplasia, which is typical of the vascular lesions associated with FMD, was observed in both patients. The presence of such intimal lesions suggests that there was a systemic factor that caused the formation of recurrent thrombi in the systemic vessels in these patients. These cases are the first ones reported in which an association between FMD and pulmonary hypertension has been observed. The pathogenesis of the thrombi in our patients was thought to be recurrent pulmonary thromboembolisms resulting from FMD.

Adolescent↗
PubMedDate not supplied

Total extracardiac right heart bypass using a polytetrafluoroethylene graft.

BACKGROUND: With regard to hemodynamics and late arrhythmias, total cavopulmonary connection has been accepted as a superior technique as compared to Fontan type procedures. However, intra-atrial baffles for lateral tunnel or conduit remain construction retain some similar disadvantages. PATIENTS AND METHODS: As an alternative to total cavopulmonary connection, total extracardiac right heart bypass using a polytetrafluoroethylene tube for the inferior vena cava to pulmonary artery connection may obviate some problems. Five patients with complex heart disease necessitating one ventricle repair underwent this procedure successfully. RESULTS: Aortic cross-clamp time ranged from 0 to 24 minutes (mean = 15.8 min). No case required takedown or an additional step. Although the follow-up periods have been relatively short (mean = 19 months), all patients are well and no arrhythmic event or thromboembolic episode has occurred. CONCLUSIONS: As a simple, safe, and reproducible procedure, total extracardiac right heart bypass is an alternative to Fontan or total cavopulmonary connection procedure.

Blood Vessel Prosthesis↗
PubMedDate not supplied

Refractoriness to platelet transfusion following double valve replacement in an ITP patient who had undergone splenectomy.

Reports of patients with idiopathic thrombocytopenic purpura (ITP) undergoing cardiac surgery are rare, and almost all of the reported cases required platelet transfusion. ITP patients, especially those having a history of splenectomy or a history of heavy bleeding, may have to undergo multiple platelet transfusions. Such transfusions may induce alloimmunization against the human leukocyte antigen (HLA) and result in refractoriness to subsequent platelet transfusions. We report a case of a 63-year-old female with ITP, with a history of splenectomy and multiple platelet transfusions, who underwent aortic and mitral valve replacement. Although corticosteroid administration, high-dose immunoglobulin therapy, and repeated platelet transfusion led to a temporary increase in platelet count and successful hemostasis, refractoriness to platelet transfusion occurred postoperatively because of the presence of the anti-HLA antibody. In addition, the patient showed complications of pyothorax. Corticosteroids might have exerted an inhibitory influence on the occurrence of pyothorax.

Aortic Valve↗
PubMedDate not supplied

Disseminated cholesterol embolism after coronary artery bypass grafting.

Blue toe syndrome caused by cholesterol emboli is a relatively benign disease. However, disseminated cholesterol embolism is a life-threatening condition. We describe here the case of a 71-year-old female admitted because of anterior chest pain and intermittent claudication. Following cardiac catheterization, warfarin potassium was administered. However, the patient's toes soon darkened bilaterally, and BUN and creatinine levels increased from the normal value. Skin discoloration and renal failure were improved after stopping warfarin potassium administration. The patient underwent coronary artery bypass grafting and left femoropopliteal bypass. Cerebral infarction and renal failure occurred postoperatively due to disseminated cholesterol embolism. The patient died from renal failure on the 16th postoperative day without regaining consciousness following surgery. For high risk patients, interventional procedures to the ascending aorta must be avoided. When CABG cannot be avoided for coronary revascularization, off-pump bypass and use of arterial grafts are recommended.

Aged↗