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Biomedical subjects

M Kamori

Publications and source records attributed to M Kamori.

9 recordsLinked to original sources

Activities of dipeptidyl peptidase II, dipeptidyl peptidase IV, prolyl endopeptidase, and collagenase-like peptidase in synovial membrane from patients with rheumatoid arthritis and osteoarthritis.

We examined the activities of peptidases in the synovial membrane from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Dipeptidyl peptidase II (DPP II), prolyl endopeptidase (PEP), and collagenase-like peptidase (CLP) activities were higher in knee joint synovial membrane from patients with RA than in that from patients with OA. DPP II and PEP activities in knee joint synovial membrane of patients with RA increased in parallel with the increase in joint fluid volume, whereas DPP IV activity decreased in parallel with the increase in joint fluid volume. These results suggest that these peptidases in the synovial membrane may play some role in immunological disturbances in the joints of patients with RA. Measurement of these peptidases in synovial membrane may be useful in the diagnosis of the severity of local joint inflammation.

Amino Acid Sequence↗

[Analysis of intraluminal flow velocity profile in peripheral arterial reconstruction--with special reference to the effect of abnormal flow wave on postoperative thrombosis formation].

Normal and abnormal flow wave forms electromagnetically determined in the reconstructed peripheral arteries were analysed in terms of luminal velocity profile using a model pump system "Flow Wave Form Simulation Pump" which was designed and constructed by us. In the blood flow with normal flow wave, the velocity gradient in the limited layer adjacent to the wall at the straight as well as dilatated or constricted part of the conduit was found to become larger with formation of a boundary layer. In addition, a respective fluctuation on velocity, including reversal stream during the phase of cardiac diastole, was found to be characteristic in a cardiac cycle. In contrast, in the flow with abnormal wave, the velocity in the layer adjacent to the wall was always stagnant with little alteration in velocity gradient during each phase of a cardiac cycle. A stagnation of flow velocity in the layer adjacent to the wall would be a source in facility of platelet deposition on the luminal surface of the reconstructed artery, and such would lead to vascular occlusion. Accordingly, it was highly considered that the flow wave form is a useful indicator to assess the outcome of the reconstructive surgery since the hemodynamic property of the reconstructed artery is reflected in the electromagnetically determined flow wave form.

Arteries↗

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↗

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↗

Venous reconstruction by endvenectomy with temporary arteriovenous fistula for stasis syndrome of lower extremity: experimental and clinical studies.

Effect of the temporary arteriovenous fistula on venous reconstruction for stasis syndrome of the lower extremity was studied experimentally and clinically. The canine iliac vein was replaced with an autogenous vein graft in which the intimal surface was roughened by scrubbing with sponge. A temporary arteriovenous fistula which was closed surgically three or four weeks later was created between the femoral vessels. The patency rate for twenty-one grafts was 80.9 per cent for one to thirty-six weeks (mean 8 weeks), in contrast to complete failure in the control group in which no arteriovenous fistula was created. Adequate healing of the luminal surface of the grafts were experimentally demonstrated by light microscopic examination and en face silver staining of the endothel-like cells with the aid of patent arteriovenous fistula for three weeks. This procedure was clinically applied in four patients with stasis syndrome of the lower extremities. Good function of the reconstructed venous segments in three of four patients was observed for the last 3 to 8 years after the operations. A looping technique using 2-0 monfilament nylon around the fistula devised by us was very helpful to make easy the shunt closure later. Open endvenectomy with a temporary arteriovenous fistula is believed to be an acceptable approach for segmental chronic occlusive lesion in the iliac vein.

Adolescent↗

Long-term results of reconstructive surgery for aorto-iliac arterial occlusive lesions.

We report a review of 215 reconstructions for aorto-iliac arterial occlusive lesions, involving 156 patients. At 13 years, the cumulative patency rate of 158 aorto-femoral or aorto-iliac dacron synthetic bypass prostheses was 71.6 per cent as compared to 52.7 per cent at 5 years for 22 blunt endarterectomies and 47.4 per cent at 6 years for 35 axillo-femoral bypass prostheses. Of the 158 synthetic bypass prostheses, the cumulative patency rate at 13 years was 85.1 per cent in cases with no occlusive involvement of the peripheral arteries, significantly higher (p less than 0.03) than the 39.3 per cent patency rate at 7 years in cases in which associated femoro-popliteal occlusive lesions were not treated. At 12 years, the patency rate was 53.2 per cent in cases in which associated femoro-popliteal occlusive lesions were treated during the same reconstructive intervention, i.e. markedly higher (p less than 0.08) than in patients in whom the degree of outflow in the distal vessels was poor. Our findings indicated that, in order to achieve a satisfactory long-term patency rate, it is important to treat associated occulusive lesions in the femoro-popliteal arteries.

Adolescent↗

Long-term results of reconstructive surgery for femoro-popliteal arterial occlusive lesions.

A retrospective review of 156 reconstructions performed for femoro-popliteal arterial occlusive lesions in 141 patients was carried out in terms of the reconstructive procedure and the degree of out-flow in the distal vessel. The cumulative patency rate for 95 autogenous vein grafts was 60.7 per cent at 12 years and higher than the 27.4% patency rate for 50 endarterectomies (p less than 0.001). All of 11 synthetic bypass prostheses failed with late thrombosis within 3 years after operation. The cumulative patency rate in cases with good distal run-off vessel and those with fair distal run-off vessel were 77.1% at 11 years and 57.3% at 12 years, respectively, and these values were significantly superior to 10.3% in cases with poor distal run-off vessel. The patency rate for 41 in situ grafts was 72.2%, being superior to 65.5% for 42 free grafts.

Adolescent↗

Comparative study on the fibrinolytic activity of pseudointima in varying types of autovein grafting.

Three types of autovein grafting procedures have been commonly employed for peripheral arterial reconstruction, that is, non-reversed, reversed and in-situ autovein grafting, and these procedures were comparatively studied in dogs to assess the best one for grafting. In the fibrinolytic activity of the internal surface of the grafts, as measured by standard fibrin plate method and Todd's fibrin slide technique, the in-situ autovein graft showed the highest activity, 139.5% in the mean, followed by 18% (mean) in the reversed autovein graft and 5.2% (mean) in the nonreversed autovein graft. The extent of fibrous proliferation of the pseudointima was least in the in-situ graft followed by the reversed and the non-reversed graft. These results suggest that preservation of the vasa vasorum is the most important factor to minimize fibrous proliferation of the graft pseudointima and to maintain high fibrinolytic activity on the internal surface of the graft. Consequently, the in-situ autovein grafting appears to be the most suitable method to ensure peripheral arterial continuity following surgical reconstruction.

Animals↗