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Biomedical subjects

H Okabayashi

Publications and source records attributed to H Okabayashi.

At least 37 records · Page 2Linked to original sources
PubMed1996

Cardiac papillary fibroelastomas: rationale for excision.

We experienced a case of papillary fibroelastoma of the left ventricular outflow tract in a patient with severe valvular heart disease that was detected only by transesophageal echocardiography. Preoperative detection of this lesion altered the surgical procedure to include resection of the mass through the aortic valve annulus along with repair/replacement of the valves. The literature documents sufficient morbidity/mortality to support excision of these lesions regardless of symptoms or location.

Echocardiography, Transesophageal↗
PubMed1996

[Combined treatment with resection, intraoperative hypotonic and post-operative systemic chemotherapy using cis-platinum for a mediastinal yolk sac tumor: a case report].

Generally yolk sac tumor in the mediastinum is a rare and highly malignant neoplasm. We report a case of yolk sac tumor, which was treated with resection, and then intraoperative hypotonic and postoperative systemic chemotherapy. A 33-year-old man was diagnosed as a mediastinal tumor with chest X-ray and chest CT findings. At operation he had mediastinal tumor which invaded to the part of the right upper lobe and pericardium, disseminated on the right diaphragm. A large tumor was removed with partial pericardiectomy and wedge resection of the right upper lobe. After resection hypotonic chemotherapy with cis-platinum was performed. This tumor had endodermal sinus structure, Schiller-Duval body, and eosinophilic hyaline globolus which were histological characteristics of yolk sac tumor, and the value of serum alpha-fetoprotein (AFP) was high. After operation with this diagnosis systemic chemotherapy consisted of cis-platinum, etoposide were performed. Patient was discharged uneventfully 8 months later.

Adult↗
PubMed1995

Biochemical and molecular characterization of nucleoside triphosphate hydrolase isozymes from the parasitic protozoan Toxoplasma gondii.

We have previously reported the presence of a novel nucleoside triphosphate hydrolase (NTPase) in the rapidly multiplying tachyzoite form of a virulent strain (RH) of Toxoplasma gondii. On further examination, it was found that the purified enzyme was not a single enzyme but was a mixture of two isozymes termed NTPase-I and NTPase-II. The two isozymes had similar molecular masses of approximately 240-270 kDa by gel filtration and contained four identical subunits of molecular mass 66-67 kDa by SDS-polyacrylamide gel electrophoresis. Both forms of the NTPase were activated by dithiothreitol, and NTPase-I had a specific activity 4.5-fold higher than NTPase-II in hydrolysis of ATP. The primary difference between these isozymes lies in their ability to hydrolyze nucleoside triphosphate versus diphosphate substrates. While NTPase-II hydrolyzed ATP to ADP and ADP to AMP at almost the same rate, NTPase-I hydrolyzed ADP to AMP at a much slower rate (0.7% of the rate for ATP). The complete cDNAs for NTPase-I and NTPase-II were sequenced and found to encode the same size predicted open reading frame of which only 16 of 628 amino acids differed between the two isozymes. Both forms of the NTPase contained an NH2-terminal hydrophobic signal peptide, consistent with our previous findings that these enzymes are secreted into the host cell vacuole occupied by the parasite. The gene encoding NTPase-II was found in all strains of Toxoplasma, while the NTPase-I was confined only to virulent strains. Expression of this highly active ATPase (NTPase-I) may contribute to intracellular survival and virulence of T. gondii.

Acid Anhydride Hydrolases↗
PubMed1995

[Mitral and aortic annular enlargement for small mitral annulus after mitral annuloplasty].

Mitral and Aortic valve rings were enlarged in a 70-year-old female with tiny mitral annulus after mitral annuloplasty before. She had undergone aortic valve replacement with No. 21 SJM valve and Kay's annuloplasty 10 years previously. The reoperation was needed because of mitral stenosis and tricuspid regurgitation. We applied the Manouguian technique for the enlargement of the mitral annulus because it was too small to implant a prosthetic valve, even though the Aortic prosthetic valve was functioning well. As too tight a mitral annuloplasty may make the possibility of mitral stenosis real, we should make the annulus remain wide enough.

Aged↗
PubMed1995

[A case report of tracheal stenosis due to true aortic arch aneurysm of retroesophageal right aortic arch associated with so called vascular ring-facial syndrome].

A 63-year-old man admitted to our hospital because of dyspnea and inspiratory stridor. The X-ray computed tomography and angiogram revealed tracheal stenosis due to compression by aortic arch aneurysm of retroesophageal right aortic arch. His face was congenitally asymmetrical, and he also showed anotia, and meatal atresia. In the operation, we approached the aneurysm via median sternotomy and left thoracotomy by the 3rd intercostal space, and found atretic left aortic arch in front of trachea. So, operative diagnosis was Edwards Ib complete vascular ring associated with right aortic arch aneurysm. The aneurysm was incised and the arch and its branches were reconstructed with vascular prosthesis under ECC using selective cerebral perfusion. Postoperatively, until 5th postoperative day his condition was uneventful, and he was neurologically almost normal. But on the 5th postoperative day, his hemodynamics suddenly deteriorated because of severe pneumonia and septicemia. On the 6th postoperative day, he died in spite of earnest resuscitation. We could not find any previous reports about this rare combination of diseases.

Abnormalities, Multiple↗
PubMed1995

[A successful case of emergency CABG using PCPS due to acute myocardial infarction].

A successful case of emergency CABG (Coronary Artery bypass Grafting) by using PCPS (Percutaneous Cardio Pulmonary Bypass) for a 60-year-old with shock due to acute myocardial infarction was reported. He developed shock due to acute myocardial infarction before arrival at our hospital. He was resuscitated by PCPS. Coronary angiography revealed that LMT was 99% stenosed and LAD just proximal was totally occluded. Emergency CABG was performed to LAD and CX using saphenous vein grafts. Post-operative course was uneventful and the patient was discharged at hospital two months after the operation. PCPS is useful for bridge until emergency CABG.

Cardiopulmonary Bypass↗
PubMed1995

[The hazards of coronary revascularization under hypothermic ventricular fibrillation].

Since January 1992 till June 1994, we experienced 22 cases of coronary revascularization (CABG) under hypothermic ventricular fibrillation (Vf) in patients with unclampable ascending aorta (Group 2). We compared them with patients undergoing conventional CABG with cardioplegic cardiac arrest (Group 1). All these 362 cases were primary isolated CABG. Comparing preoperative patient profile, patients of Group 2 were older (Group 1: 64.3 +/- 8.5, Group 2: 68.2 +/- 6.7 year old, p < 0.05), had more unstable angina (Group 1: 20.3%, Group 2: 54.5%, p < 0.001), and had more severe NYHA classification (Group 1: 2.22 +/- 0.55, Group 2: 2.73 +/- 0.46, p < 0.05) than Group 1. There were no significant difference between both groups about other factors. Comparing post operative complication, low output syndrome (Group 1: 2.6%, Group 2: 18.2%, p < 0.005) perioperative myocardial infarction (PMI) (Group 1: 4.4%, Group 2: 36.4%, p < 0.0001) ventricular tachycardia (VT) (Group 1: 1.4%, Group 2: 18.2%, p < 0.0001), respiratory failure (Group 1: 3.8%, Group 2: 18.2%, p < 0.005), and post operative hospital death (Group 1: 2.9%, Group 2: 18.2%, p < 0.0005) occurred more frequent in Group 2 than Group 1. Other complication (renal failure, wound infection, cerebrovascular accident, rethoracotomy for bleeding) equally occurred in both groups. Long Vf time (mean 92.8 minutes) and low perfusion pressure during Vf (mean 60.0 mmHg) were suspected to be major cause of high incidence of PMI and VT in Group 2. But there were no correlation between Vf time, perfusion pressure and occurrence of PMI and/or VT.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

[Risk factors of wound infection following cardiac surgery and antimicrobial prophylaxis].

To make investigation about risk of wound infection following cardiac surgery, we analyzed cases of primary aorto-coronary bypass surgery and/or primary valvular surgery. Cases required respirator for longer than 2 days, and those with drainage tube for longer than 5 days were excluded from this study, because these cases had antimicrobial agent postoperatively as therapeutic use rather than prophylactic use. Those received preoperative antimicrobial agent for infectious endocarditis and so on were also excluded for the same reason. 523 cases were entered this study. These cases received cefazolin (CEZ) postoperatively as prophylaxis. Sternal wound and leg/groin wound were separately analyzed. Risk factors (age, sex, diabetes mellitus, unstable angina, use of intraaortic balloon, internal thoracic artery harvest, re-exploration, previous myocardial infarction, NYHA classification, emergent operation, operation time, extracorporeal circulation time, blood product use, preoperative blood hemoglobin concentration, preoperative serum albumin, preoperative creatinine clearance (Ccr), duration of drainage tube insertion, body surface area, daily dose of CEZ, duration of prophylaxis) were examined using univariate (Chi square test was used for contingency table analysis, unpaired t test was used to compare averages) and multiple regression analysis. For sternal wound infection, only Ccr showed significant (P = 0.027) correlation. For leg/groin wound infection, 2 factors (smaller daily dose of CEZ: P = 0.009, more severe NYHA class: P = 0.03) showed significant correlation. To investigate appropriate duration of CEZ prophylaxis, cases were divided into 2 groups, those had CEZ within 48 hours postoperatively (group S) and those had CEZ for longer than 48 hours (group L).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[A case report of successful surgical treatment of acute postinfarction left ventricular free wall rupture using the percutaneous cardiopulmonary support system].

The percutaneous cardiopulmonary support system (PCPS) was used in a 75-year-old female with a blow out type heart rupture of the posterior wall complicating acute myocardial infarction. The patient was transported to the operating room with the PCPS and IABP in place, and had the ventricular rupture repaired as well as CABG. Although the postoperative cardiac function was satisfactory she sustained ischemic cerebral stroke and went on to die of aspiration pneumonia 166 day later. PCPS buys time to enable surgical repair of the heart, but how to protect the brain remains as a problem to be solved.

Aged↗
PubMed1994

Immunohistochemical and pathological characteristics of dystrophic amyloid in surgically excised cardiac valves.

One hundred and thirty-six cardiac valves obtained surgically from 124 patients (aged 15-77 years) were examined. Microdeposition of amyloid was present in sclerotic or sclerocalcific lesions of aortic valves in 38 out of 75 (51%) and mitral valves in 21 out of 61 (34%). Amyloid deposition was not significantly related to the age of the patients. An antiserum raised against a low molecular weight protein extracted from amyloid-laden valvular tissues (about 20 g) reacted positively to amyloid in the cardiac valves. It did not react to amyloid deposition containing fibril proteins including light chain related amyloidosis, reactive amyloidosis, systemic senile amyloidosis, isolated atrial amyloidosis, beta-2-microglobulin related amyloidosis and beta protein related amyloidosis. Further, amyloid in the cardiac valves failed to react immunohistochemically to anti-AA, anti-AL, anti-TTR, anti-ANF, anti-beta 2M and anti-beta protein antibodies. These findings suggest that an unknown amyloid protein is involved in the damaged valves.

Adolescent↗
PubMed1993

[Transcranial Doppler monitor in the case of selective cerebral perfusion].

Six patients underwent ascending aorta and aortic arch replacement for aneurysmal disease between 1991.12-1992.2 using the cardiopulmonary bypass technique with selective cerebral perfusion from right axillary artery. For four patients, intraoperative transcranial Doppler monitorings of left MCA flow velocity were done. We added left carotid artery perfusion for 5 patients because of old age; 1, intraoperative finding of anisocoria; 1 and low left MCA flow velocity on the TCD monitor; 3. After the addition of left side perfusion, the left MCA flow velocity on the TCD monitor recovered to normal level in the 3 patients. TCD reflected the cerebral perfusion state every minutes and seemed to be very useful monitor in selective cerebral perfusion. It also suggested that unilateral cerebral perfusion does not supply enough blood flow in contralateral side of brain in many cases. To another patient who also underwent aortic arch replacement, we examined preoperatively left MCA flow velocity on the TCD monitor under left carotid artery compression. This "carotid artery compression test" was thought to suggest the degree of right to left intracranial collateral blood flow via Willis's circle. TCD image, when the left carotid artery was clamped, was compared with the result of preoperative "carotid artery compression test". But we can't evaluate the results quantitatively now.

Aged↗
PubMed1993

[6 cases of CABG post coronary stent].

In recent years, percutaneous transluminal coronary angioplasty (PTCA) has been actively carried out as a therapeutic method of the ischemic cardiopathies, and Stent therapy has been clinically applied as settlement method of problematical points of the acute occlusion and dissection of the coronary artery by PTCA. We experienced 6 cases necessitated coronary artery bypass graft (CABG) after insertion of Palmaz-Schatz Stent until March 1992. The emergent bypass was carried out in 3 of 6 cases because thrombotic occlusion developed although Stent was inserted in thrombotic occlusion after PTCA, while 2 cases were not life-saved because of the cardiac function was worsened before operation. Other 3 cases were life-saved by expectant treatment even though stenosis developed again after Stent therapy. Stent therapy is a useful method, while severity in cases using CABG and operative complexity are expected by development of new problematical point in the future.

Aged↗
PubMed1992

Lateral conductance parallel to membrane surfaces: effects of anesthetics and electrolytes at pre-transition.

The effects of dilute salts and anesthetics were studied on the impedance dispersion in the dipalmitoylphosphatidylcholine (DPPC) liposomes. Below the pre-transition temperature, the apparent activation energy for conductance in DPPC-H2O without salts was equivalent to pure water, 18.2 kJ mol-1. This suggests that the mobile ions (H3O+ and OH-) interact negligibly with the lipid surface below the pre-transition temperature. At pre-transition temperature, the apparent activation energy of the conductance decreased by the increase in the DPPC concentrations. The effects of various salts (LiCl, NaCl, KCl, KBr, and KI) on the apparent activation energy of the conductance were studied. Changes in anions, but not in cations, affected the activation energy. The order of the effect was Cl- less than Br- less than I-. Cations appear to be highly immobilized by hydrogen bonding to the phosphate moiety of DPPC. The smaller the ionic radius, the more ions are fixed on the surface at the expense of the free-moving species. The apparent activation energy of the transfer of ions at the vesicle surface was estimated from the temperature-dependence of the dielectric constant, and was 61.0 kJ mol-1 in the absence of electrolytes. In the presence of electrolytes, the order of the activation energy was F- greater than Cl- greater than Br- greater than I-. When the ionic radius is smaller, these anions interact with the hydration layer at the vesicle surface and the ionic transfer may become sluggish. In the absence of electrolytes, the apparent activation energy of the dielectric constant decreased by the increase in halothane concentrations. In the presence of electrolytes, however, the addition of halothane increased the apparent activation energy. We propose that the adsorption of halothane on the vesicle surface produces two effects: (1) destruction of the hydration shell, and (2) increase in the binding of electrolytes to the vesicle surface. In the absence of electrolytes, the first effect predominates and the apparent activation energy is decreased. In the presence of electrolytes, the latter effect predominates and the apparent activation energy is increased.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1992

[False aneurysm formation during the chronic phase of myocardial infarction at the margin of a previously-detected true aneurysm].

The patient was a 59-year-old man who had acute extensive anterior myocardial infarction in October, 1989. One month later, he was transferred to Kyoto University Hospital and underwent cardiac catheterization. Left ventricular aneurysm and significant stenosis in the proximal portion of the left anterior descending artery were documented. Because he experienced chest pain on slight exertion accompanied by a slight increase in the depth of the negative T wave on electrocardiogram, percutaneous transluminal coronary angioplasty (PTCA) was performed. Thereafter, chest pain disappeared, and the patient was discharged. Three months later, he was re-admitted to Kyoto University Hospital for a repeat cardiac catheterization after PTCA. PTCA site was found to be restenosed, and a small diverticulous aneurysm was found at the margin of the previously-detected ventricular aneurysm. As the diverticulous aneurysm was considered likely to precipitate the ventricular aneurysm into rupture, expeditious left ventricular aneurysmectomy was performed to prevent cardiac rupture. Ventricular aneurysms, common complications in myocardial infarction, are of two types, either true or false. Most aneurysms develop during the acute phase of myocardial infarction, and rupture of true aneurysms during the chronic phase of myocardial infarction rarely occurs. However, in the present case, a small diverticulous aneurysm, which was not demonstrated at the initial cardiac catheterization, developed during the chronic phase of myocardial infarction. Pathological examination revealed that the diverticulous aneurysm was a false aneurysm due to incomplete rupture. When the common pathogenesis of ventricular aneurysms in myocardial infarction is considered, the present report might represent an extraordinary rare case.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm, Ruptured↗
PubMed1992

[A case report of successful repair of an aortopulmonary fistula with partial dissection of the pulmonary artery].

We experienced a case of aortopulmonary fistula due to true thoracic aortic aneurysm. Surgical repair was electively performed when we found coexisting pulmonary arterial dissection. Under extracorporeal circulation, dissected flap was excised and the fistula was closed with his own pericardium, and his aortic arch and innominate artery were replaced with a piece of vascular prosthesis. His intra and post operative condition was stable, and postoperative course was uneventful. Prior to this case 13 surgically treated cases had been reported, and 5 had been successful. Among them, only 2 had been electively operated and both successful. Our case is the second case of aortopulmonary fistula associated with pulmonary arterial dissection.

Aortic Dissection↗