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T Ichihara

Publications and source records attributed to T Ichihara.

At least 73 records · Page 4Linked to original sources
PubMed1998

[The investigation of surgical procedures for post infarcted ventricular septal defects: a comparison between Daggett and David method].

Post infarcted ventricular septal perforations (VSP) has diverse clinical and pathological manifestations and the surgical results in severe cases have not yet been satisfactory. In the past we had performed the procedure of Daggett. However since 1992 we have also introduced the procedure of infarction exclusion technique proposed by David which involves plastering the ventricular cavity in a large patch without infarcted myotomy. We reported 5 cases treated with David method, 5 cases with Daggett method, and their results were compared. There were four mortality cases in Daggett method and three in David method. No significant difference was observed regarding the surgical mortality. However, there were different post-operative features between the two groups. In Daggett method patients had prolonged heart failure and LOS. In David method patients, had no severe LOS, but residual shunt were recognized in two cases. We think that the emergence of residual shunt in David method was probably due to suturing without prior removal of the damaged fragile infarcted myocardium. In Daggett method there were death cases caused by LOS and postoperative heart failure but without residual shunts. Despite its recent growing popularity for treating VSP, our experience suggests that residual shunt is an important issue remains to be solved in David method.

Aged↗
PubMed1997

Overcoming of multidrug resistance by VA-033, a novel derivative of apovincaminic acid ester.

We have studied the effects of a novel derivative of apovincaminic acid ester, VA-033, on the resistance of tumors to chemotherapeutic agents. VA-033 increased the sensitivity of drug-resistant cell lines (P388/VCR, P388/ADM, AD10, and K562/ADM) to adriamycin or vincristine. The potency of VA-033 was stronger than verapamil. The drug lengthened the survival time of the P388/VCR-implanted mice treated with vincristine. VA-033 increased the intracellular accumulation of vincristine in the tumor cells, and the photolabeling of P-glycoprotein by [3H]azidopine was inhibited by VA-033. VA-033 showed a slight inhibitory effect on the L-type Ca2+ current in the ventricular myocytes, and had less effect on the cardiovascular parameters such as blood pressure, contractile force and atrio-ventricular conduction time than verapamil when administered systemically in the dog. These results suggest that VA-033 may become a beneficial compound as a modifier to the neoplastic cell resistant to multidrugs.

Animals↗
PubMed1997

Quantitative analysis of scatter- and attenuation-compensated dynamic single-photon emission tomography for functional hepatic imaging with a receptor-binding radiopharmaceutical.

A new method for quantitative liver study was developed using the tracer technetium-99m diethylene triamine penta-acetic acid-galactosyl human serum albumin (99mTc-GSA), an analog ligand of the asialoglycoprotein receptor, which is a hepatocyte surface receptor specific for galactose-terminated glycoproteins. For quantitative dynamic single-photon emission tomographic (SPET) studies, attenuation compensation using transmission computed tomography (TCT) and the triple energy window (TEW) scatter compensation method were evaluated. As the TCT source, we used an uncollimated multi-tube source with the TEW scatter compensation method. To verify the accuracy of cross-calibrated SPET values as compared with measured radioactivities, we performed SPET of a cylindrical water pool phantom which contains seven hot rods filled with different concentrations of 99mTc activities, simulating the scan conditions in human studies. The results of the phantom studies showed good linearity and accuracy of the SPET values, with R2=0.993 and a regression line of y=0.941x+5.48. From the analysis of a kinetic model based on a one-compartment model, focussing on the initial stage of several minutes after 99mTc-GSA injection and taking the physiological expression presented in a three-compartment analysis into account, we introduced the Rutland equation (Patlak plot) in the 99mTc-GSA study by which the overall and regional effective hepatic blood flow (EHBF) and hepatic blood pool volume were determined. Preliminary clinical evaluations were performed for four normal male subjects (23-35 years of age) and one patient. Forty sequential 30-s dynamic SPET acquisitions were obtained for a period of 20 min following the intravenous injection of 99mTc-GSA with venous blood sampling at 10 min. After scatter compensation, the SPET images were reconstructed with attenuation compensation using an attenuation map obtained from TCT. The average normal value for the total EHBF was 468+/-83 ml/min and that for the hepatic blood pool volume, 777+/-123 ml. Functional images of the distribution of regional values of EHBF (ml/min/voxel) and hepatic blood pool volume (ml/voxel) were also generated corresponding to the original SPET images. The EHBF images showed regional liver function, higher in the right lobe than the left lobe in the normal cases, and the heptic blood pool volume images showed the distribution of intensified high values along major vascular structures. Receptor imaging with 99mTc-GSA using the Rutland method and dynamic SPET with scatter and attenuation compensation is an effective technique that allows the evaluation of total and regional hepatic functional parameters (EHBF, hepatic blood pool) in vivo.

Adult↗
PubMed1997

The omental flap with skin grafting for treatment of a difficult sternal closure.

A case report of difficult sternal closure is described. Chest closure following cardiac operation in critically ill patients can be a problem. Techniques have been described so that sternal closure can be delayed until the patient is hemodynamically stable and hemostasis has been achieved. However, in some instances, the sternal closure can not be performed because of prolonged cardiopulmonary instability. We describe the use of transposition of an omental flap with skin grafting in a 74-year-old patient with aortic valve stenosis, poor pulmonary function, and a thoracic deformity. This technique enabled incomplete sternal closure which maintained hemodynamic stability.

Aged↗
PubMed1997

Promotion of rat hepatocarcinogenesis by dimethylarsinic acid: association with elevated ornithine decarboxylase activity and formation of 8-hydroxydeoxyguanosine in the liver.

Arsenicals are epidemiologically significant chemicals in relation to induction of liver cancer in man. In the present study, we investigated the dose-dependent promotion potential of dimethylarsinic acid (DMAA), a major metabolite of inorganic arsenicals in mammals, in a rat liver carcinogenesis model. In experiment 1, glutathione-S-transferase placental form (GST-P)-positive foci, putative preneoplastic lesions, were employed as endpoints of a liver medium-term bioassay for carcinogens (Ito test). Starting 2 weeks after initiation with diethylnitrosamine, male F344 rats were treated with 0, 25, 50 or 100 ppm of DMAA in the drinking water for 6 weeks. All animals underwent two-thirds partial hepatectomy at week 3 after initiation. Examination of liver sections after termination at 8 weeks revealed dose-dependent increases in the numbers and areas of GST-P-positive foci in DMAA-treated rats as compared with controls. In experiment 2, ornithine decarboxylase activity, which is a biomarker of cell proliferation, was found to be significantly increased in the livers of rats treated with DMAA. In experiment 3, formation of 8-hydroxydeoxyguanosine, which is a marker of oxygen radical-mediated DNA damage, was significantly increased after administration of DMAA. These results indicate that DMAA has the potential to promote rat liver carcinogenesis, possibly via a mechanism involving stimulation of cell proliferation and DNA damage caused by oxygen radicals.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1997

Scatter and attenuation correction in technetium-99m brain SPECT.

UNLABELLED: We propose a practical method for scatter and attenuation compensation in 99mTc-ECD brain SPECT using a simultaneous emission CT (ECT) and transmission CT (TCT) acquisition system that includes the following major components: (a) triple-headed SPECT gamma camera equipped with fanbeam collimators; (b) external line sources containing 99mTc placed at the focal lines of the collimators; and (c) scatter correction by the triple-energy-window (TEW) method. METHODS: Projection images were obtained over a 360 degrees rotation scan. After acquisition, scatter correction was performed using the TEW method, which corrected scattered photons pixel by pixel in the projection data. Scatter-corrected ECT images were compensated for attenuation using the TCT images with Chang's iterative method, and were converted to activity concentration (kBq/ml) images by obtaining a cross-calibration scan. After validating this method with phantom studies, it was applied to clinical brain imaging using a combination of 925 MBq 99mTc-ECD as a radiopharmaceutical and 222 MBq 99mTc as an external source. ECT and TCT data were acquired separately or simultaneously. RESULTS: SPECT quantification and image quality were improved by performing this correction. The activity concentration images obtained with the simultaneous acquisition were almost identical to those obtained with the separate acquisition. CONCLUSION: This method was clinically practical and cost-effective for reconstructing quantitative 99mTc brain SPECT images.

Brain↗
PubMed1997

[New surgical procedure for patients with dilated heart and end-stage cardiac failure (Batista procedure)].

A 53-year-old man with dilated cardiomyopathy underwent left ventriculoplasty (Batista procedure), a new surgical procedure, which reduces ventricular volume to improve left ventricular function. Left ventricular ejection fraction increased from 19.7% to 43.7%. Unfortunately, he died of pneumonia 12 days after surgery. This is the first such procedure in a human in Japan.

Cardiac Surgical Procedures↗
PubMed1997

[Antitumor effect of S-1 and cisplatin treatment against human gastric cancer xenografted in nude mice].

The enhanced effects due to the combined use of oral administration of S-1 and intraperitoneal administration of Cisplatin (CDDP) were examined with gastric cancer xenografts (NUGC 4). S-1, a new anticancer drug, was daily administered at 10 mg/kg (qld x 5 x 3 weeks). 5-FU level in blood was 1 microgram/ml at two hours after the treatment. Antitumor activity was not found in mice with only the CDDP treatment. But antitumor activity by S-1 and daily low-dose (1 mg/kg) or intermittent treatment (5 mg/kg) of CDDP showed better results than daily S-1 treatment. The daily low-dose CDDP treatment showed similar efficacy to the intermittent administration at the same total dose, but the daily low-dose CDDP treatment was better in the light of toxicities. These results suggest that treatment with S-1 and daily low-dose CDDP was effective for gastric cancer.

Administration, Oral↗
PubMed1997

[Successful emergency surgical management following cardiac massage in a patient with acute myocardial infarction due to total obstruction of the left main trunk].

The prognosis in patients manifesting shock following acute myocardial infarction due to total occlusion of the left main trunk (LMT) is usually very poor and so is the lifesaving rate. Accurate judgement and rapid response are key to the successful management of this disease. We experienced a successful case with emergency coronary artery bypass grafting (CABG) on the 14 the day after initial attack. The patient, who had total occlusion of LMT, underwent a PTCA (percutaneous transluminal coronary angioplasty) during the initial attack under cardiac massage. We think in situations where patients have cardiac arrest, shock, elevated CPK levels suggesting devastation of myocardium due either to LMT or severe triple vessels disease, early catheter intervention rather than emergency CABG would be much more tolerable as long as hemodynamic situation allows. Our previous experience taught us that immediate surgical intervention with CABG usually resulted in poor outcome. Further refinements regarding the surgical procedure, technique, assist circulatory supports, cardioplegia, etc., are indispensable before trying to have a successful emergency CABG.

Angioplasty, Balloon, Coronary↗
PubMed1997

Left ventriculoplasty: a new option for end-stage cardiomyopathy.

To treat end-stage dilated cardiomyopathy, we have performed volume reduction left ventriculoplasty (as introduced by Randas Batista in Brazil) in four patients since December 1996. All patients had end-stage idiopathic cardiomyopathy. Mitral valve replacement was also performed in three patients. In all four patients, improvement of left ventricular function was noted. One patient died of respiratory failure on the 12th postoperative day. The other three patients recovered successfully from the operation (i.e., they were discharged from hospital with the functional status in New York Heart Association Class I or II). We conclude that the Batista operation provides a real hope for patients with end-stage dilated cardiomyopathy.

Adult↗
PubMed1996

Malignant lymphoma of the gastric stump developing 25 years after a distal gastrectomy for benign gastric disease: report of a case.

We report herein the case of a 57-year-old man in whom malignant lymphoma originating in the gastric remnant was confirmed 25 years after a subtotal gastrectomy with Billroth II reconstruction had been performed for gastric ptosis. Gastroscopy revealed an ulcerated tumor on the fornix, and histologic examination of the endoscopic biopsy specimens demonstrated malignant lymphoma. Thus, total gastrectomy with splenectomy, pancreatectomy, and resection of the previously anastomosed jejunal stoma were performed. Histologic examination of the stomach remnant confirmed a diagnosis of B-cell lymphoma of the large-cell type. Although we were unable to study the surgical specimen from the initial operation, the possible relationship between pseudolymphoma and malignant lymphoma has been presented in the literature, which is reviewed following this case report.

Anastomosis, Roux-en-Y↗
PubMed1996

Evaluation of SPET quantification of simultaneous emission and transmission imaging of the brain using a multidetector SPET system with the TEW scatter compensation method and fan-beam collimation.

A gamma camera system which is able to acquire simultaneous single-photon emission tomographic (SPET) data and gamma ray transmission computed tomography (TCT) data for brain study using external rod sources and fan-beam collimators was developed and evaluated. Since the three external rod sources were located at the focal points of fan-beam collimators, which also happened to be the apexes of the equilateral triangle defined by the three detectors, simultaneous SPET and TCT scan could be performed using a 120 degrees shared scan. Therefore, the proposed system required less than one-third of the scanning time of a single-head system. Since the combination of rod sources and fan-beam collimators decreased the scatter component in transmission data without a slit collimator for each rod source, the radioactivity of the rod source was less than one-tenth of the previous investigations. For evaluation, we used two isotopes, thallium-201 for TCT and technetium-99m for SPET. The cross-contamination of transmission and emission was well compensated using the triple energy window (TEW) method. In a separate TCT scan, the measured attenuation coefficient of 201Tl for water was 0.19+/-0.01 cm-1, while in a simultaneous scan, it was 0. 20+/-0.01 cm-1. The measured attenuation coefficient for water agreed well with the narrow-beam (theoretical) value of 0.187 cm-1. In SPET images, scatter compensation was also performed using the TEW method and attenuation compensation was done using the measured attenuation map. The results showed the feasibility of simultaneous SPET and TCT scanning using the TEW method to obtain quantitative SPET images.

Brain↗
PubMed1996

Neoadjuvant chemotherapy in scirrhous cancer of the stomach using uracil and tegafur and cisplatin.

We administered a mixture of uracil and tegafur (UFT)/cisplatin (CDDP) chemotherapy in 28 patients with scirrhous gastric cancer. In the regimen, UFT was orally administered at a dose of 200 mg/m2 twice a day. The CDDP was administered at a dose of 90 mg/m2 by 24-hour continuous infusion every 4 weeks. As a result, antitumor effects for primary gastric foci were achieved in 14 of the 28 patients (50%). Ascites from peritoneal dissemination disappeared completely in eight of 13 patients (62%). Total gastrectomy was performed in ten patients after 2 to 3 courses of chemotherapy. Histological response grades assessed on the resected specimen were Grade 2 in four, Grade 1b in three, Grade 1a in one and Grade 0 in two patients. Neoadjuvant chemotherapy is feasible against scirrhous gastric cancer and a subsequent prospective randomized trial should be prepared to clarify the survival benefit of the treatment.

Adenocarcinoma, Scirrhous↗
PubMed1996

A new isopatulin derivative pintulin produced by Penicillium vulpinum F-4148 taxonomy, isolation, physico-chemical properties, structure and biological properties.

During our screening program of natural products from fungal metabolites for drugs effective against tumor cell lines, we discovered a new isopatulin derivative, pintulin, from the fermentation broth of Penicillium vulpinum F-4148. Pintulin shows weak activity against tumor cell lines, compared to that of adriamycin.

Antibiotics, Antineoplastic↗
PubMed1996

[Case report of David's operation for annuloaortic ectasia and aortic regurgitation in a Marfan patient].

We report a 35-year-old Marfan patient who underwent David's operation for annuloaortic ectasia and aortic regurgitation. This new technique is done by excising the aneurysmal portion of the ascending aorta and sinuses of Valsalva but by leaving the aortic valve leaflets and some aortic wall attached to the left ventricular outflow tract inside the Dacron tube. Postoperative echocardiography revealed well coapted aortic valve leaflets and a very small amount of regurgitation. A rigid aortic route without sinuses of Valsalva may increase the mechanical stress on the leaflets and shorten their durability but this procedure have the advantage of so called Bentall's operation by preserving the native aortic valve.

Adult↗
PubMed1996

[A case of traumatic tricuspid regurgitation with bilateral pericardial laceration].

A case of traumatic tricuspid regurgitation with bilateral pericardial lacerations is presented. The patient was a 68-year-old male with a chief complaint of dyspnea on exertion, who had had chest contusion in an automobile accident 17 years before. Two dimensional echocardiography demonstrated a systolic prolapse of the tricuspid anterior leaflet resulting in massive regurgitation. The right atrial v wave was 25 mmHg. Intraoperative findings were as follows: Three healed tears of 4-6 cm long were present in the both sides of the pericardium. The chordae tendineae of the anterior leaflet were ruptured. The tricuspid valve was replaced with a SJM valve prosthesis. To our knowledge, no case of combined tricuspid insufficiency and bilateral pericardial laceration resulting from blunt injury has ever been reported.

Aged↗