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Biomedical subjects

T Kawata

Publications and source records attributed to T Kawata.

At least 163 records · Page 9Linked to original sources
PubMed1994

[Efficacy of GRF (gelatin-resorcin-formalin) glue on surgery for type A aortic dissection].

The tissue biological adhesive GRF glue has been used in our department to have dissected aortic layers adhered and to reinforce the dissected aortic stumps during surgery for aortic dissection. From May 1992 to August 1993, 12 patients were operated for type A aortic dissection; 4 patients with acute dissection and 8 patients with chronic dissection. There were 5 men and 7 women whose ages ranged from 51 to 69 years with an average of 60.6 years. Replacement of the ascending aorta alone was performed for 6 patients. Replacement of both the ascending aorta and transverse arch was carried out for 4 patients, and replacement of the ascending aorta, transverse arch and the descending aorta was accomplished in 1 patient. Primary repair was performed for 1 patient with intraoperative acute dissection that occurred during surgery for mitral valve. There were no operative or hospital deaths. Preoperative aortic regurgitation was present in 5 patients. Following gluing the aortic root dissection, aortic regurgitation disappeared in all patients confirmed by postoperative aortograms. The use of GRF glue significantly reduced the average amount of intraoperative bleeding from 2893 ml to 1169 ml and also significantly reduced the use of Teflon felt strips for the proximal anastomosis. We believe that use of GRF glue can improve the surgical outcome for acute and chronic aortic dissection.

Aged↗
PubMed1994

[Percutaneous transluminal angioplasty for stenosis of coronary artery bypass grafts: a comparison of arterial grafts versus vein grafts with regard to restenosis and re-do CABG].

Stenoses of ten arterial grafts and thirty-four venous grafts from previous coronary artery bypass grafting (CABG) were treated with percutaneous transluminal angioplasty. In all ten arterial grafts, stenosis occurred at the distal coronary anastomotic site (A-d). In vein grafts, stenosis occurred at the proximal aortic anastomotic site (V-p) in 10, at the graft body (V-b) in 9 and the distal coronary anastomotic site (V-d) in 10 vessels. The initial success rates of angioplasty were 89% (A-d), 100% (V-p), 89% (V-b) and 100% (V-d). The time period between CABG and angioplasty was significantly shorter for A-d (4 +/- 3.8 months) and V-d (8.1 +/- 9.9 months) groups than for V-p (56.9 +/- 35.7 months) or V-b (45.9 +/- 48.6 months) groups. The restenosis rates following angioplasty were 0% (A-d), 50% (V-p), 50% (V-b) and 0% (V-d). Repeat CABG surgery was required for restenosis in 2 patients of group V-p and V-b. Our experience suggests that angioplasty can be performed with a high success rate for stenosis at the distal anastomosis of either arterial or vein grafts after CABG.

Anastomosis, Surgical↗
PubMed1994

Hemodynamic assessment during exercise after left ventricular aneurysmectomy.

The exercise hemodynamics of eight patients who underwent cardiac catheterization were assessed at rest and during exercise, before and after left ventricular aneurysmectomy by the classical technique. Left ventricular end-diastolic volume increased before operation and then significantly decreased after the operation (p < 0.05). The ejection fraction increased from 0.27 before the operation to 0.46 after the operation (p < 0.01). The cardiac index, which was low before operation, increased within the normal range after operation. Mean systolic circumferential tension also decreased significantly (p < 0.01) after the operation. Thus, the indexes at rest showed improvement. Left ventricular end-diastolic pressure showed a decreasing tendency after the operation both at rest and during exercise in comparison with that before the operation. However, the difference was not significant. The stroke work index increased significantly during exercise after the operation (p < 0.05). Before the operation, the stroke work index did not increase despite the elevation of left ventricular end-diastolic pressure; however, after the operation, the stroke work index increased during exercise without much increase of left ventricular end-diastolic pressure. This indicated improvement in the Frank-Starling curve and recovery of preload reserve by the resection of the left ventricular aneurysm. Thus, an important factor for demonstrating improvement in postoperative cardiac function was clarified through its relation to exercise load.

Cardiac Output↗
PubMed1994

[Allograft (homograft) valve surgery: current status in Japan].

The advance of cryopreservation techniques has dramatically increased the durability of human allograft valves, resulting in the wide-spread use of allograft valves in many western countries except Japan. The superiority of the allograft valve to other prosthetic valves has become apparent in some specific situations such as active endocarditis, small aortic root and hemorrhagic conditions. In this manuscript, we described the setting-up of the cryopreservation laboratory, quality control and the clinical use of allograft valves in our institute. The authors believe that surgeons should have an option of utilizing allograft valves in selected patients in Japan.

Adult↗
PubMed1994

[Coronary artery bypass surgery-redo operation particularly in patients with a functioning ITA graft or with a patent atheromatous vein graft].

An experience with redo-CABG in 20 patients is described. The incidence of reoperation in patients undergoing primary CABG in our hospital was 1.4%, relatively low even in Japanese population. The low incidence of redo-CABG in our hospital depends on the relatively short period of follow-up of 14 years, the prevalence of interventional cardiology and the early routine use of ITA grafts. The main cause of reoperation was the failure of a SVG to the LAD in 70 to 80% of the cases. The most important and difficult decision-making in redo-CABG is the selection of surgical approaches and cardioprotective methods in patients with a patent functioning ITA graft, and the management of an atherosclerotic patent SVG. Surgical strategies in these situations are discussed.

Adult↗
PubMed1993

Participation of cathepsin L on bone resorption.

The proteinase responsible for bone collagen degradation in osteo-resorption was examined. The bone pit formation induced by parathyroid hormone (PTH) was markedly suppressed by leupeptin, E-64 and cystatin A, while no inhibition was observed by CA-074, a specific inhibitor of cathepsin B. Pig leucocyte cysteine proteinase inhibitor (PLCPI), a specific inhibitor of cathepsin L, and chymostatin, a selective inhibitor of cathepsin L, completely inhibited the pit formation. Cathepsin L activity in osteoclasts was much higher than the other cathepsin activities. Serum calcium in rats placed on a low calcium diet was decreased by treatment of E-64 or cystatin A, but not by CA-074. These findings suggest that cathepsin L is the main proteinase responsible for bone collagen degradation.

Animals↗
PubMed1993

Exercise coronary flow reserve of bilateral internal thoracic artery bypass grafts.

We attempted to quantify the exercise coronary flow reserve in 20 patients with bilateral internal thoracic artery grafts to the left coronary arteries (group I) who had complete revascularization. The coronary sinus blood flow was measured by the continuous thermodilution method both at rest and during exercise (50 W for 8 to 9 minutes) approximately 1 month after the operation. These results were compared with 30 patients treated with an internal thoracic artery and saphenous vein grafts to the left coronary arteries (group II) and 9 patients with saphenous vein grafts alone to the left coronary arteries (group III). There were no differences among the three groups in age, sex, number of vessels involved, heart rate, double products, left ventricular (LV) end-diastolic pressure, LV ejection fraction, LV end-diastolic volume, or LV mass at the time of study. None of the 59 patients in the study had abnormally enlarged LV end-diastolic volume or increased LV mass. The postoperative coronary sinus blood flow per 100 grams of LV mass at rest was similar among the three groups (73.0 +/- 28.4 mL/min per 100 g LV mass in group I, 73.4 +/- 31.1 mL/min per 100 g LV mass in group II, and 75.9 +/- 28.5 mL/min per 100 g LV mass in group III [not significant]) and significantly (p < 0.01) increased by exercise, although the differences between groups during exercise were not significant (158.9 +/- 45.9, 153.5 +/- 72.1, and 148.3 +/- 60.0 mL/min per 100 g LV mass, respectively [not significant]).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1993

Lower extremity ischemia secondary to internal thoracic-coronary artery bypass grafting.

Vascular complications associated with the use of the internal thoracic artery as a conduit for coronary artery bypass are infrequent. However, acute limb-threatening ischemia can occur after the use of the internal thoracic artery for myocardial revascularization when this vessel forms an important collateral to an obstructed aortoiliac artery system. Although this is a rare complication, the consequences are devastating. Due to the risk of peripheral vascular insufficiency, we now perform simultaneous revascularization of the myocardium and the lower extremity when an internal thoracic artery that appears to be a major collateral to the ipsilateral aortoiliac system is used.

Acute Disease↗
PubMed1993

Role of Harderian gland on differentiation and proliferation of immunoglobulin A-bearing lymphocytes in chickens.

The mechanism of accumulation of surface immunoglobulin A (sIgA) bearing cells in chicken Harderian gland (HG) was examined. Almost no sIgA-bearing cells were identified in HG of 1.5-week-old chickens. In 3.5-week-old chickens, however, 46.4% of the HG lymphocytes were sIgA-bearing cells. When bursa of Fabricius (BF) lymphocytes were transferred into recipients, BF lymphocytes migrated into the HG but the number of these lymphocytes was extremely small. In addition, no correlation was found between the surface immunoglobulin class of BF lymphocytes that migrated into HG and the migration. HG lymphocytes were co-cultured with HG whole cells (which contained 50-60% configurationally epithelial cells) in a non-contacting manner for 80 h using an Intercell culture vessel. The results showed a significant increase in the ratio of sIgA-bearing cells in HG lymphocytes compared with the control which was cultured without placing HG whole cells in the external well. B lymphocytes that migrated into HG seemed to undergo specific differentiation in situ into sIgA-bearing cells owing to microenvironmental factors, probably humoral factors excreted from HG epithelial cells, and subsequently undergo proliferation to result in accumulation of sIgA-bearing cells in HG tissue.

Animals↗
PubMed1993

[Cardiac function following left ventricular aneurysm repair--comparison between patch reconstruction and direct closure methods].

Left ventricular function was compared between two groups of patients who underwent patch reconstruction or direct closure of the ventricular wall following resection of a post-infarction left ventricular aneurysm (LVA). There were 15 and 9 patients in the respective groups. Coronary artery bypass grafting was additionally performed in 8 patients (53%) in the patch reconstruction group and 5 patients (56%) in the direct closure group. The size of the patch used for patch reconstruction (including the suture line) was 57 +/- 19% of the resected area. Before and 1-2 months after surgery, equilibrium RI angiography and cardiac catheterization were performed to assess the following hemodynamic parameters: ejection fraction (EF) at rest and during exercise, left ventricular end-diastolic pressure (LVEDP), left ventricular end-diastolic volume index (LVEDVI), cardiac index (CI) and mean pulmonary artery pressure (m-PAP). Preoperatively, there were no differences in each parameter between the two groups. Postoperatively, there were significant improvements in the EF at rest and during exercise (p < 0.01), LVEDVI (p < 0.01) and the LVEDP (p < 0.05). However there no significant changes in CI or m-PAP following the operation. There were also no significant differences observed in the postoperative values between the two groups. However, based upon postoperative left ventriculograms, patch reconstruction was significantly superior to direct closure for reconstruction of a septal aneurysm.

Aged↗
PubMed1993

[Cell viability assessment of cold-preserved (4 degrees C) and cryopreserved (-196 degrees C) allograft valves by flowcytometric analysis].

We introduced cryopreservation technique to store the allograft valve and subsequently commenced the use of the cryopreserved aortic allograft valve for aortic valve replacement. For the clinical use of the allograft valve, it is essential to evaluate the cell viability. We assessed cell viability of the allograft valve by flowcytometry (FCM), using a fluorescein diacetate (FDA)-propidium iodide (PI) stain. Pulmonary allograft valves were harvested from the cadavers with a consent. Of the 9 valves collected and sterilized in 4 degrees C antibiotic solution for 48 hours, 4 valves were stored under refrigeration (cold-preserved), and the remaining 5 valves were cryopreserved. The warm ischemic time from cardiac death to valve preservation was 7.3 +/- 5.4 hours. The cold-preserved valves were stored at 4 degrees C in the nutrient medium (TC-199, calf serum and HEPES buffer). The cryopreserved valves were frozen by a programmable freezer to -80 degrees C in the same nutrient medium containing 10% dimethylsulfoxide (DMSO), and subsequently stored in liquid nitrogen (-196 degrees C). We assessed the cell viability of the allograft valve leaflet, before storage and at 2 weeks, 1 month and 2 months after the storage. Suspensions of the valve leaflet fibroblasts were double-stained with FDA (1 micrograms/ml) and PI (1 microgram/ml) for flowcytometric analysis of the viable cells (cells showing a chromatic response to FDA but no response to PI). In the cold-preserved group, percentage of the viable cell was 90.3 +/- 3.6% before storage, 62.0 +/- 3.0% after 1 month of storage, and 50.3 +/- 3.7% after 2 months of storage.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1993

[Late results of aortic valve plasty (aortic leaflet slicing) simultaneously performed with mitral valve surgery].

We followed the course of 20 patients who underwent aortic valve plasty (AVP) combined with mitral valve surgery for rheumatic mild aortic valve disease in association with severe mitral valve disease. At operation, all patients underwent aortic leaflet slicing with a knife, and aortic commissurotomy were performed additionally in 10 patients. After surgery, the degree of aortic valve regurgitation and the amplitude of aortic leaflet motion were assessed chronologically, using ultrasound cardiography. One month after surgery, all but one patients showed a reduction in regurgitation to degree I or less. From the third post-operative year, however aortic valve regurgitation tended to increase again. However, the post-operative degree of regurgitation was observed not to be severer than the pre-operative degree of regurgitation, and no patients showed aggravation of aortic valve regurgitation attributable to exacerbation of mitral valve disease. We divided the patients into two groups according to improvement of aortic valve regurgitation. In the group where the degree of regurgitation returned to the pre-operative one, the degree of amplitude of leaflet motion began to reduce from the third post-operative year and was nearly equal to the pre-operative one at the fifth post-operative year. The results of this study can be summarized as follows: 1. From the third post-operative year, aortic regurgitation was aggravated and aortic valve motion amplitude decreased. 2. The number of sliced valve leaflets and incised commissures did not correlate well with the post-operative reduction in regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Trigeminal nerve endings of lingual mucosa and musculature of the rat.

Horseradish peroxidase conjugated with wheat germ agglutinin (HRP-WGA) was injected into the trigeminal ganglion of adult rats to label the peripheral sensory receptors of the tongue. The conjugate was transported anterogradely to all the ipsilateral fungiform papillae and filiform papillae. Some labeled fibers crossed over to the contralateral papillae. In the intrinsic tongue muscle undulating nerve fibers along or across muscle fibers were often observed, and formed simple spiral endings.

Animals↗
PubMed1992

Isolation and characterization of a cDNA clone encoding the TATA box-binding protein (TFIID) from wheat.

We isolated a complementary DNA (cDNA) encoding the TATA-binding factor 'TFIID' from a wheat seedling cDNA library. The wheat TFIID transcript of 1.2 kb poly(A)+ RNA was expressed at a low level early in germination, but gradually increased as the seedlings developed. In vitro binding experiments showed that the bacterially expressed wheat TFIID protein could specifically bind to the TATA boxes of the cauliflower mosaic virus (CaMV) 35S, wheat histone H3 and adenovirus major late genes with different affinity. A comparison with Arabidopsis TFIID showed the presence of a plant-specific region consisting of 13 amino acids at the divergent amino terminus and a conserved region (182 amino acids) at the carboxy terminus longer than that observed in yeasts (180 amino acids) and animals (181 amino acids).

Amino Acid Sequence↗
PubMed1992

Angiographic demonstration of no-flow anatomical patency of internal thoracic-coronary artery bypass grafts.

To clarify the no-flow situation of the stringlike internal thoracic artery graft, we angiographically examined such grafts by temporarily occluding the recipient coronary artery with a percutaneous transluminal coronary angioplasty balloon and were able to reveal anatomical patency of the internal thoracic artery graft in 2 patients 1 year and 3 years after the operations. Thus, there is a possibility that internal thoracic artery grafts may continuously maintain anatomical patency even under no-flow situations just like nonfunctioning collateral vessels and may function properly later as a graft when the native coronary flow decreases. Also, this angiographic technique can be a new method for detecting anatomical patency of no-flow and functionally closed internal thoracic artery grafts.

Anastomosis, Surgical↗
PubMed1992

A broad-host-range vibriophage, KVP40, isolated from sea water.

A broad-host-range vibriophage, KVP40, was isolated from sea water by using Vibrio parahaemolyticus 1010 (EB101) as the indicator host. The host range of KVP40 extended over at least 8 Vibrio and 1 Photobacterium species. KVP40 was a large tailed phage containing double-stranded DNA and belonged to Ackermann's morphotype A2. KVP40 DNA was cleaved by 11 different type II restriction endonucleases including EcoRI and HindIII, but not by 17 other enzymes including BamHI, KpnI and SalI.

Bacteriophages↗
PubMed1992

Effects of vitamin B12-deficiency on testes tissue in rats.

The state of vitamin B12-deficiency in rats was evaluated by determination of hepatic vitamin B12-dependent enzyme activities after the animals had fed on a vitamin B12-deficient soybean protein diet for 150 days. The effect of vitamin B12-deficiency on testicular tissue was also studied by morphological observations. Growth of vitamin B12-deficient rats was retarded and marked increase in urinary methylmalonic acid was observed. Vitamin B12 contents in the organs were depressed distinctly by the deficiency, especially in testes, vitamin B12 content decreased to 2.5 ng/g. Hepatic methionine synthase and methylmalonyl-CoA mutase activities showed striking depression to 5% of the control rats and extreme vitamin B12-deficiency was confirmed. Testes weight also showed marked decrease together with their relative weight per 100 g body weight. Morphological observations of testes of vitamin B12-deficient rats revealed atrophy of the seminiferous tubules and aplasia of sperms and spermatids. The above results proved that vitamin B12-deficiency affected rat testes, and suggested that the rat could be the animal model for elucidation of the mechanism of B12 action on testicular functions.

Animals↗