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Biomedical subjects

A Kusaba

Publications and source records attributed to A Kusaba.

At least 19 recordsLinked to original sources
PubMed1992

Microscopic and immunohistological studies on intimal hyperplasia of the arterially implanted autovein graft and its anastomosis in dogs.

The fate of intimal hyperplasia of arterially implanted autovein bypass grafts and their distal end-to-side anastomoses in dogs was studied microscopically and immunohistologically. The bypass grafting was done under conditions of abnormal blood flow and high peripheral resistance. Intimal hyperplasia of the graft first became evident 7 days after implantation and the thickness increased to about 500 microns 3 months or more after the implantation. The intimal hyperplasia was related to an active proliferation of smooth muscle cells which proved positive for alpha-smooth muscle actin staining. Moreover, it was more dominant at the toe and heel of the anastomosis and moderately apparent on the floor of the host artery. The constituent elements of the hyperplastic intima at the anastomosis were fibroblast-like cells and extracellular collagen fibers which were negative for alpha smooth muscle actin staining. This study revealed that the features of intimal hyperplasia at the distal anastomosis in autovein bypass grafting differed from those of the implanted autovein graft itself; the former being related to excessive proliferation of fibroblasts and collagen fibers while the latter displayed an active proliferation of smooth muscle cells.

Animals↗
PubMed1992

Hypertension in an adult with unilateral renal dysplasia.

We report a 29-year-old Japanese female with severe hypertension and unilateral renal dysplasia, which is rarely found in adults. The involved kidney was surgically removed and then the blood pressure fell to borderline levels without any changes in plasma renin activity or plasma aldosterone concentration. Histological examinations revealed typical renal dysplasia without hyperplasia of the juxtaglomerular apparatus. Unilateral renal dysplasia may be a cause of secondary hypertension in adults, though the mechanisms are still unknown.

Adult↗
PubMed1991

Clinical studies on the vasodilating and anti-platelet effects of OP-41483, a prostacyclin derivative.

The vasodilating and anti-platelet actions of OP-41483 was studied to determine the effective dose of this drug for the treatment of ischemic lower limbs. The compound was given to 11 patients intravenously at rates of 2.5, 5.0 and 10.0 ng/kg/min. Infusion at a rate of 10 ng/kg/min increased the mean flow rate of the tibial arteries from 3.15 +/- 1.77 ml/min before the infusion, to 7.89 +/- 2.51 ml/min (p less than 0.001) and to 6.38 +/- 3.19 ml/min (p less than 0.001), at the time of, and 60 minutes after the cessation of the infusion, respectively. The peripheral flow resistance of the tibial arteries was reduced from 2.1 +/- 1.12 X 10(5) dyne.sec/cm5 before the infusion to 0.9 +/- 0.33 X 10(5) dyne.sec/cm5 (p less than 0.001) and to 1.2 +/- 0.78 X 10(5) dyne.sec/cm5 (p less than 0.05), at the time of, and 60 minutes after the cessation of the infusion. ADP-induced platelet aggregation was reduced from 73.3 +/- 17.6% before the infusion to 50.7 +/- 24.5% (p less than 0.01) and to 64.0 +/- 23.5% (p less than 0.05), at the time of, and 60 minutes after the cessation of the infusion, respectively. Collagen-induced platelet aggregation was also reduced from 71.4 +/- 24.0% to 66.6 +/- 21.5% before and after the infusion (p less than 0.05).

Aged↗
PubMed1991

Severe hypertension with segmental renal infarction following surgical removal of a retroperitoneal malignant hemangiopericytoma: a case report.

Severe hypertension developed in a fifty-five year-old woman after surgical removal of a retroperitoneal tumor, when the renal artery was injured. Renal arteriography after the surgery demonstrated a segmental infarction of the right kidney. A close relationship between activation of the renin-angiotensin system and the development of severe hypertension was observed. Satisfactory control of blood pressure concomitant with reduction of plasma renin activity was achieved by a combination of an angiotensin-converting anzyme inhibitor, beta-blocking agent, and calcium-entry blocker. The mechanism of activation of the renin-angiotensin system in renal infarction is discussed.

Female↗
PubMed1990

Tissue and cellular distribution of alpha-L-iduronidase in the pig.

We investigated the alpha-L-iduronidase activity of various pig tissues. Furthermore, we examined the tissues using antibody, enzyme immunoassay (EIA), and immunohistochemical methods. The amounts of enzyme measured by the EIA method in the various tissues were proportional to their enzyme activities and also to their immunohistochemical characteristics. The tissues could thus be classified into three groups: a high enzyme activity group composed of the liver, kidney, and spleen; a moderate activity group comprising the lung, lymph nodes, stomach, ileum, colon, and pancreas; and a low activity group consisting of the heart, diaphragm, iliopsoas muscle, cerebrum, cerebellum, and skin. The molecular weight of the enzyme in each tissue did not reveal any heterogeneity, having two components of 70 KD and 62 KD by Western blot analysis. Immunohistochemically, alpha-L-iduronidase was strongly detected in the lysosomal membranes of cells of the mononuclear phagocyte system, epithelial cells of the proximal tubules in the kidney, and some blastic cells, whereas hepatocytes revealed weak positive reactions. The tissue and cellular distribution of the enzyme appeared to have a close relation to tissues that manifest or are affected by alpha-L-iduronidase deficiency.

Animals↗
PubMed1990

[A study on surgical cases of pulmonary aneurysm].

We performed 830 cases of open heart surgery in the past 12 years and two of those cases were complicated by pulmonary aneurysm. The first case was a 21-year-old female with annuloaortic ectasia and treated by partial resection and plication of the pulmonary aneurysm associating of partial resection and plication of the pulmonary aneurysm associating of Bentall's procedure. Pathological examination revealed the findings of Aortitis syndrome, i.e., inflammatory granuloma with round cells infiltration and fragmentation of elastic fibers in the medial as well as adventitial layers. The second case, a reoperation case, was a 44-year-old female with valvular disease, MSR, TSR, Pr and treated by partial resection of the pulmonary aneurysm associating with MVR, TVR, and PA valve plasty. Pathological examination revealed hyalin and necrobiotic degeneration of the media. Both cases involved had pulmonary hypertension suggesting a role for pulmonary hypertension along with organic changes of the vessel in the pathogenesis of the aneurysm.

Adult↗
PubMed1989

Venous reconstruction for iliofemoral venous occlusion facilitated by temporary arteriovenous shunt. Long-term results in nine patients.

In nine patients with iliofemoral venous occlusion, venous reconstructions using a temporary arteriovenous shunt were performed by open thromboendvenectomy with autogenous vein patch angioplasty in four, expanded polytetrafluoroethylene (ePTFE) bypass grafts (including two with external ring-supported ePTFE) in four, and Palma's procedure in one patient. There was an adequate function in the reconstructed venous segments in two of four who underwent thromboendvenectomy and in all four with ePTFE bypass grafting for nine months to 13 years after surgery. In those with a temporary arteriovenous shunt, prepared to maintain patency of the reconstructed venous segments, blood flow through the shunt exceeded 100 mL/min, determined by an electromagnetic flowmeter. Postoperative shunt closure was readily facilitated, using a looping technique and a 2-0 nylon. The increased blood flow through the graft made feasible by the temporary arteriovenous shunt enhanced the patency of the reconstructed venous graft and hence there was an improvement in the affected limb.

Adolescent↗
PubMed1985

Idiopathic arterial calcification in 9-year-old boy: a successful reconstruction for ilio-femoral occlusion.

We treated a 9-year-old boy suffering from underdevelopment of the length as well as circumference of the left lower extremity due to idiopathic arterial calcification of the left ilio-femoral artery. There was no deposition of calcium on the other arteries and tissues of the body. He had undergone aorto-internal iliac bypass graft with resection of the calcific iliac and superficial femoral arteries in the National Fukuoka Central Hospital when he was 4 years old, but the graft became occluded. He was admitted to the University of the Ryukyus Hospital. The common femoral artery was completely occluded with severe deposition of calcium on the wall and with gritty contents. The profunda femoris artery and the proximal part of the superficial femoral artery were also completely occluded with organized thrombi. Re-establishment of blood flow to the ischemic left lower extremity was performed with an ilio-femoral cross-over synthetic bypass and femoro-popliteal saphenous vein bypass graft, in situ. The patient has been well with adequate pulses of the pedal and posterior tibial artery 8 months after surgery.

Arterial Occlusive Diseases↗
PubMed1985

Five-year clinical evaluation of the St. Jude Medical valve prosthesis in 136 patients.

One hundred and thirty-six patients (June 1979, through May 1984) underwent mitral, aortic or double valve replacement and apico-aortic bypass with the St. Jude Medical (SJM) prosthesis, at Ryukyu University Hospital, Okinawa. Operative mortality for the entire group was 4.4 per cent. Late mortality from 1979-1984 was 6.1 per cent. There were no deaths related to mechanical failure. Warfarin anticoagulation was recommended for all patients. The incidence of thromboembolism was 0.76/100 patient years. Post operative catheterization studies in 21 patients one year after operation showed a satisfactory recovery of cardiac function. The SJM valve seems to be the satisfactory artificial valve in present use.

Adolescent↗
PubMed1982

Intraluminal velocity profile analyzed from flow waveforms.

Normal and abnormal flow waveforms, electromagnetically measured in the reconstructed arteries of patients with peripheral occlusive diseases of the lower extremity, were analyzed in terms of luminal velocity profile, using a newly designed flow wave simulation pump. The blood flow with normal flow wave was characterized by a large fluctuation in the velocity profile in the limited layer adjacent to the wall, where a reversal stream was characteristically noted during the phase of cardiac diastole. In contrast, in the abnormal flow wave, the velocity profile in the limited layer adjacent to the wall was always stagnant with little change in the velocity during each phase of a cardiac cycle. These observations clearly explain why an artery with a normal flow waveform remains patent, while an artery with an abnormal waveform tends to occlude. It was also found that the electromagnetically determined flow waveforms do provide the required information on the luminal velocity distribution.

Adult↗
PubMed1981

Ultrasonic flow wave pattern as a prognostic indicator in peripheral arterial reconstruction.

A prognostic flowmetric study on 80 reconstructed arteries of the lower extremity was carried out to assess the flow wave patterns detected using a bidirectional doppler flowmeter. In 21 of 80 arteries, changes in the flow wave pattern were noted. For 10 of 21 affected arteries, an immediate arteriography revealed localized stenotic lesions at the distal anastomosis, in a short segment of the implanted autogenous vein graft or at the proximal host artery. Immediate repairs for the lesions were successfully performed by a minor surgery in 8 of 10 cases and the flow wave pattern reverted to normal. Two were not successful as the occlusion was complete before attempting the repair. The remaining 11 are now under conservative management as these patients refused further surgery. The ultrasonically driven flow wave pattern proved to be a useful indicator to assess the patency of the reconstructed peripheral artery to detect possible stenosis and thereby to take proper corrective measures and hence prevent a late occlusion.

Arterial Occlusive Diseases↗
PubMed1981

Absorbable suture materials for vascular anastomoses. Tensile strength and axial pressure studies using polyglycolic acid sutures.

This study attempted to evaluate how vascular healing itself is sufficient enough to provide adequate strength to autogenous vein grafts in small arteries without the use of nonabsorbable sutures. The absorbable suture, Dexon, was used in small canine femoral vein graft anastomoses over a two-month trial period with nonabsorbable Prolene as a control. Tensile strength and resistance to axial leak were measured. Results show that Dexon had 93 per cent of the tensile strength of Prolene immediately; 76 per cent at 14 days, 111 per cent at 21 days, and 110 per cent at 30 days, and 124 per cent at 60 days as an average for all suture lines. The per cent mean resistance to leakage that Dexon had compared to Prolene for all suture lines was 102 per cent at seven days, 97 per cent at 14 days, 107 per cent at 21 days, and 97 per cent at 30 days. There is no evidence of aneurysms, suture line disruptions, dilations, or infections of any anastomoses. Our ultimate conclusion is that the integrity of small autogenous vein graft is dependent on healing rather than on the permanent strength of the suture material and that Dexon maintains vascular integrity long enough to permit this healing to occur.

Absorption↗