Biomedical subjects

Y Ohkawa

Publications and source records attributed to Y Ohkawa.

At least 55 records · Page 3Linked to original sources

PubMed1993

Surgical treatment of congenital biliary dilatation associated with pancreaticobiliary maljunction.

The excisional surgical treatment of 50 patients with congenital biliary dilatation (CBD) associated with pancreaticobiliary maljunction (PBMJ) was analyzed. There were two patients who had early complications of lesser bile juice leakage with a maximum duration of 21 days, but no pancreatic juice leakage was noticed. As a late complication, two strictures at the anastomotic portion of the hepaticojejunostomy and one intrahepatic gallstone formation were encountered, but no malignant lesion was evident. Both patients with strictures could be predicted using postoperative cholangiography performed two weeks postoperatively and underwent hepaticojejunostomy. Intrahepatic gallstones were treated with lateral segmentectomy of the liver and electrohydraulic lithotripsy through percutaneous transhepatic cholangioscopy. Accordingly, these results suggest that excisional surgical treatment is the most appropriate method for CBD with PBMJ; however, special care must be taken, such as creating a sufficiently wide anastomotic stoma to enable free drainage of bile into the intestine; also, there should be precautions against ischemia at the anastomotic portion. The importance of the postoperative cholangiography to predict the postoperative outcome should be emphasized. Furthermore, causes of intrahepatic gallstone formation should be studied in such instances.

Adolescent↗

PubMed1993

[Surgical treatment of double-outlet right ventricle with left ventricular outflow tract obstruction].

Three patients with double-outlet right ventricle (DORV) and left ventricular outflow tract obstruction (LVOTO) were described. In each patient, LVOTO was produced by restrictive VSD which resulted from malalignment of the conal musculature and a discrete subaortic membrane. All patients underwent surgical repair with enlargement of the ventricular septal defect and rerouting of the outflow tract from the left ventricle to the aorta. One patient died of congestive heart failure three months postoperatively. Causes of LVOTO and surgical management of DORV with LVOTO were discussed.

Cardiac Surgical Procedures↗

PubMed1993

[Intravascular ultrasound imaging on the endarterectomized coronary arteries in two patients].

Intravascular ultrasound imaging on the endarterectomized coronary arteries in two patients are reported with a review of the literature. Case 1, a 62-year-old male and case 2, a 64-year-old male underwent endarterectomy of the right coronary artery (#3--#4PD, 4AV) combined with coronary arterial bypass grafting. Coronary arteriography (CAG) and intravascular ultrasound imaging (IVUS) were performed one month after operation. CAG revealed bypass grafts and endarterectomized coronary arteries to be patent together, and IVUS revealed endarterectomized coronary arteries had two layers, outer layer to be hyperechoic and inner layer to be heterogenously echoic in both cases. The histological examination of specimens suggests this heterogenously echoic area represents media, thrombus and irregularly proliferated intima. Therefore, anticoagulant therapy after endarterectomy should be strictly performed.

Coronary Artery Bypass↗

PubMed1993

[Emergency operation for complete papillary muscle rupture after myocardial infarction--a case report of 81-year-old patient].

Mitral regurgitation due to complete rupture of the papillary muscles after myocardial infarction has a very poor prognosis, even if diagnosed and operated on at an early phase. Recently, we performed an emergency operation for mitral regurgitation due to complete papillary muscle rupture after myocardial infarction in an 81-year-old patient. This is probably the oldest case in Japan. Operation revealed complete rupture of the posterior papillary muscle, and valve replacement with a Carpentier-Edwards bioprosthesis was performed.

Aged↗

PubMed1992

[Transjugular intrahepatic portosystemic stent shunt (TIPSS) with use of Rösch-Uchida transjugular liver access set--evaluation by CT and its clinical application].

Appropriateness of the Rösch-Uchida transjugular liver access set designed for TIPSS procedure was confirmed, especially about the catheter angle and effective length of the 20 G puncture needle, by CT analysis on three dimensional vascular anatomy of the liver. Clinically, TIPSS using the set was successfully made for two patients, connecting superior right hepatic vein with right portal vein in one patient and middle hepatic vein with left portal vein in another patient with hypoplastic right portal vein. Prior to TIPSS procedure, verification of vascular anatomy on CT images is the key to success of TIPSS in safe.

Evaluation Studies as Topic↗

PubMed1992

Studies on natural antioxidants in citrus species. I. Determination of antioxidative activities of citrus fruits.

The antioxidative activities of twenty types of citrus fruits were investigated with a screening method which is based on rat liver microsomal lipid peroxidation induced by dihydronicotinamide adenine dinucleotide phosphate (NADPH) and adenosine diphosphate (ADP). The activities of the exocarp were greater than those of the sarcocarp and the activities from immature fruits (collected in July-August) were greater than those from mature fruits. The strongest antioxidative activity was found in ponkan (Citrus reticulata Blanco) collected in July.

Animals↗

PubMed1992

Antitumor effect of pluronic F-127 gel containing mitomycin C on sarcoma-180 ascites tumor in mice.

Pluronic F-127 (PLF-127) gels were evaluated as a sustained-release vehicle for intraperitoneal administration of mitomycin C (MMC) in order to enhance the therapeutic effects of MMC against a Sarcoma-180 ascites tumor in mice. Tumor cell injections were made on day 0 and injections of MMC in 25% (w/w) PLF-127 on day 1, both intraperitoneally. A prolongation of the life span of tumor-bearing mice following injection of therapeutic PLF-127 was noted, and PLF-127 containing MMC was therapeutically more active than free drug. The high chemotherapeutic efficiency of MMC in PLF-127 was striking at high doses, which would be toxic in the case of the drug alone. PLF-127 gels exhibit reverse thermal behavior and are fluid at refrigerator temperature, but are soft gels at body temperature. The in vitro release experiments indicated that Pluronic gel might serve as a rate-controlling barrier and be useful as a vehicle for sustained-release preparations of MMC to be administered intraperitoneally. These results suggest that sustained-release occurs in the peritoneum and that effective drug concentrations can be maintained by the preparation.

Animals↗

PubMed1992

[A case of acute right ventricular infarction and life-saving right ventricular assistance following emergency coronary revascularization and resection of a left ventricular aneurysm--discussion of indication and proper assist flow volume].

Right ventricular assistance (RVA) using centrifugal pump in combination with IABP was used to treat a patient who was difficult to wean from a cardiopulmonary bypass following emergency coronary revascularization and resection of a ventricular aneurysm performed to treat acute right ventricular infarction due to a PTCA complication. After 131 hours of RVA at 3.2 to 4.8 l/min, it was possible to remove the pump. No heparin was administered during this time, changing the pump head twice, was used for 64 and 50 hour period, no thrombi were detected either time. After being weaned from RVA, the patient developed severe respiratory dysfunction, but on the 10th postoperative day (POD) IABP was weaned, and on the 13th POD the artificial respirator was withdrawn. The results of the postoperative cardiac catheterization were favorable, the patient was discharged on the 57th POD, and has returned to society at the present time. The indications for RVA include a central venous pressure > 20 mmHg and a cardiac index < 1.8 l/min/m2, and tissue perfusion pressure and general preoperative condition should severe as guides. The higher the assisted flow volume the more efficacious in relieving ventricular load, but, since there is a limit to how much the left ventricle and lungs can withstand, it should not exceed levels which ensure the maintainance of cardiac output and tissue perfusion pressure.

Angioplasty, Balloon, Coronary↗

PubMed1992

[Experience of intravascular ultrasound imaging on a stenosed saphenous vein graft].

A 73-year-old man underwent coronary-artery bypass grafting surgery on #4 PD and #7 with saphenous vein graft. Coronary arteriography and graft visualization performed on the 28th postoperative day revealed 75% concentric stenosis in the middle of the #4 PD graft. Before and after PTCA to the graft, examination by intravascular ultrasound imaging was performed and revealed that the stenosis was caused by fibrotic atheroma or thrombus. Intravascular ultrasound imaging appears to be useful in the field of cardiac surgery. It can be used in the follow-up of bypass grafts and also the detection of the entry site in dissecting aortic aneurysms. A brief review of the literature is given.

Aged↗

PubMed1991

Improved prognosis of acute nonlymphocytic leukemia in children: results of the 12th-ANLL protocol of Tokyo Children's Cancer Study Group.

Thirty-one children with ANLL were treated using the 12th-ANLL Protocol of the Tokyo Children's Cancer Study Group incorporating an ACMP 2-step regimen. Induction therapy consisted of two 4-day courses of adriamycin (ADR) and cytosine arabinoside (ARA-C) given with a 7-day interval. Those patients who achieved remission were given one more course as early intensification. Late intensification consisted of a 5-day course of ARA-C and one dose of ADR which was repeated until the cumulative dosage of ADR reached 465 mg/m2. After this point, treatment was divided into 2 courses. Both courses included ARA-C and one course had achlacinomycin in addition. Twenty-seven children (87%) attained remission after one or two courses of induction therapy. Kaplan-Meyer analysis revealed that the continuous complete remission rate and event-free survival were 71% and 51%, respectively, 5 years after diagnosis. Toxicity was minimum with only one death during the remission. These results are encouraging and warrant further trials.

Adolescent↗

PubMed1991

[Operative management of the calcified patent ductus arteriosus in the elderly].

Two cases of the calcified PDA were experienced in subjects aged more than 50 years. A 63-year-old woman was successfully operated upon. A Fogarty's balloon catheter was wedged into the PDA through the ductus after a pulmonary arteriotomy under cardiopulmonary (CP) bypass. A 57-year-old woman was safely operated. PDA was repaired under partial CP bypass with Bio-pump. Postoperative courses of these cases were uneventful. Brief review of surgical treatment for PDA was given.

Calcinosis↗

PubMed1991

[A case of retrosplenial amnesia].

A case of retrosplenial amnesia was reported. The patient was an 81-year-old right-handed male. He developed amnesic syndrome following cerebral infarction situated left retrosplenial region. His immediate memory was preserved. Recent memory for both verbal and nonverbal modalities was disturbed. He also showed retrograde amnesia for 2 years. The is the first report of retrosplenial amnesia in Japan. We should take into account of the retrosplenial region as a causative site of amnesic syndrome.

Aged↗

PubMed1990

Degradation and isomerization of nileprost, 5-cyano-16-methyl-prostacyclin, in aqueous solution.

Nileprost is a new prostacyclin analogue stabilized by introduction of the cyano group at its 5-position. The acidic and alkaline degradation and the structure determination of the degradation products were investigated. The degradation of nileprost is very slow in comparison with that of prostacyclin. Although prostacyclin is easily decomposed to 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) through the hydrolysis of a vinyl ether moiety, nileprost gives little of such hydrolysis product but many isomers and dehydrates. The structures of the products were determined by high-performance liquid chromatography (HPLC), negative ion fast atom bombardment mass spectra (N-FABMS) and nuclear magnetic resonance (NMR) studies. It was found that the vinyl ether moiety of nileprost is converted from 5Z form to 5E form in both media, and that the omega-side chain also undergoes transfer of hydroxyl group or dehydration in acid medium. These results indicate that introduction of the cyano group into the 5-position of prostacyclin is extremely effective for the stabilization of the vinyl ether moiety. Furthermore, on the basis of the structural elucidation, the reaction mechanism of nileprost in both media was clarified.

Drug Stability↗

PubMed1990

[Eleven cases of ASD in individuals aged over 50 years].

Eleven cases of ASD were experienced in subjects aged more than 50 years. The ages ranged from 50-68 years (mean: 57.1 years), and there were 6 males and 5 females. The preoperative NYHA class was I in three cases, II in six cases, and III in two cases. The pulmonary arterial pressure ranged from 20-46 mmHg (mean: 30.9 mmHg), the PP/PS 0.19-0.42 (mean: 0.25), the QP/QS 1.4-3.5 (mean: 2.3), and the left to right short circuit rate was 38-73% (mean: 58.6). A patch closure operation was performed in all cases except two. After operation, the NYHA class improved in all cases except one. The CTR decreased from 59.3 +/- 6.05% to 54.1 +/- 5.07, and the pulmonary arterial pressure from 30.3 +/- 6.65 mmHg to 21.4 +/- 5.04 mmHg (improving in all cases).

Aged↗

PubMed1989

Idiopathic acquired generalized anhidrosis: electron-microscopic and immunohistochemical studies and analysis of lectin-binding pattern of the cell membrane.

Idiopathic acquired generalized anhidrosis with sudden onset is rare and its pathogenesis is not known. We report a patient with this condition, and the results of electron-microscopic and immunohistochemical studies as well as an analysis of the lectin-binding pattern of the cell membrane. Electron-microscopically, the cells of the eccrine sweat gland showed vacuolar changes. Besides their cytoplasmic changes, the results of a deficient lectin-binding pattern of the glandular cells suggest that there are disturbances in the formation of glycoproteins on their membrane.

Adult↗

PubMed1989

[Parkinsonism, depression and akathisia induced by flunarizine, a calcium entry blockade--report of 31 cases].

Flunarizine hydrochloride (FZ), a calcium entry blockade, has been used nationwide in Japan as a cerebral active vasodilator since October, 1984. The present paper reports 31 cases of FZ-induced Parkinsonism, depression and akathisia, referred to our hospital between October 1986 and September 1988. Out of the 31 patients, four including two with Parkinson's disease and one each with progressive supranuclear palsy and olivopontocerebellar atrophy showed worsening of their parkinsonian symptoms within a few months after FZ administration. The remaining 27 patients (7 males and 20 females) newly developed Parkinsonism after treatment with FZ. Symptoms appeared one week to two years (mean: 6.1 months) after starting FZ of a daily dose of 10 mg. FZ had been used in 6 patients for cerebrovascular episodes confirmed by clinical history or brain CT, and in the remainder, for dizziness, light-headedness, hypertension, amnesia or hypochondric neurotic complaints. Akinesia and bradykinesia progressed rather rapidly after onset, and patients became unambulatory within several months. Symptoms had worsened, and L-dopa, anticholinergic drugs, and bromocriptine had been ineffective until FZ was discontinued. Their Parkinsonism was characterized by marked akinesia, bradykinesia, and moderate rigidity. Masked face was seen in most of them. Tremor was absent at rest, and induced in 12 patients by posture and/or action. Sixteen patients were accompanied by depression, and five, by akathisia. Improvement began several weeks after withdrawal of FZ, and most patients recovered almost completely within a few months although mild rigidity and bradykinesia remained in some.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

[Treatment of congenital tracheal stenosis. Retrospective study of thirteen cases].

Thirteen cases of congenital tracheal stenosis (CTS) were retrospectively studied in terms of operative indication and treatment. The intratracheal transverse ratio of the stenotic/normal diameter (stenotic ratio, SR) was obtained by chest X-ray, tracheogram or autopsy, as one of the parameters of stenosis. SR ranged from 0.14 to 0.50 (mean 0.35 +/- 0.13 SD). Two cases (SR = 0.14) received tracheal resection and reanastomosis successfully. In three cases with pulmonary artery sling (PAS), PA translocation was performed to release tracheal compression. One (SR = 0.49) had good result but two (SR = 0.20, 0.30) died from respiratory failure (RF) and autopsy revealed PAS. Four cases underwent surgery for congenital heart disease (CHD), 3 (SR = 0.41, 0.46, 0.49) had good results but one (SR = 0.36) died from RF. In four cases medically treated, 3 (SR = 0.40, 0.44, 0.50) improved with growth but one (SR = 0.25) died before operation due to RF and autopsy revealed PAS. When SR greater than or equal to 0.40, cases without PAS improved with conservative treatment, those with PAS improved by PA translocation, and those with CHD tolerated open heart surgery. When SR less than 0.40, tracheal reconstruction is indicated. Cases with PAS would require primary or staged operation of PA translocation + tracheal reconstruction. The most appropriate therapy should be selected on the basis of symptoms, associated diseases and parameter of tracheal stenosis, for instance "SR".

Anastomosis, Surgical↗

PubMed1989

[Multi-infarct dementia clinically simulating dementia of Alzheimer type. A comparison with angular gyrus syndrome].

A 74-year-old right-handed man with multiple cerebral infarction who presented with dementia simulating dementia of Alzheimer type (DAT) is reported. He had been well until April 20, 1987 when he developed transient right hand palsy lasting overnight. Eleven days later, he became confused, disorientated, and amnestic. He was admitted to this hospital on June 8. Physical examination revealed hypertension (170/90mmHg). On neurological examination, his consciousness was clear but he was demented. He showed disorientation, amnesia, and urinary incontinence. His most prominent symptom was disturbance of speech, including fluent aphasia and alexia with agraphia. Additionally, he showed ideomotor apraxia, construction apraxia, right-left agnosia, finger agnosia, and acalculia. On July 9, he had a transient attack of right hemiplegia with confusion. The brain CT scan performed on admission was unremarkable except for cavum septi pellucidum and a small low density area in the right basal ganglia. However, single photon emission computed tomography (SPECT) by 123I-labeled N-isopropyl-p-iodoamphetamine disclosed hypoperfusion of the cerebral blood flow in the border zones of the temporoparietal and frontal lobes on the left. A follow-up brain CT scan taken one month later demonstrated low density in the new areas corresponding to hypoperfusion shown by SPECT. Although the clinical features of the present case resembled those of DAT, dementia in this case was regarded as the result of multiple cerebral infarction since it occurred acutely with mild motor deficits, and brain CT scans and SPECT showed lesions indicating focal cerebral ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗