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Biomedical subjects

R Hatano

Publications and source records attributed to R Hatano.

At least 19 recordsLinked to original sources

Enhanced activation is the mechanism of negative cross-resistance to Chlorpyrifos in the Dicofol-IR strain of Tetranychus urticae (Acari: Tetranychidae).

The mechanism responsible for negative cross-resistance to chlorpyrifos was examined in isogenic dicofol susceptible (Orchard-12) and resistant (Dicofol-IR) two-spotted spider mites, Tetranychus urticae Koch. The acetylcholinesterase of both strains was equally sensitive to inhibition by chlorpyrifos oxon. However, the Dicofol-IR strain showed increased oxidative activation of chlorpyrifos to chlorpyrifos oxon relative to the Orchard-12 strain, suggesting this mechanism is responsible for the observed negative cross-resistance.

Animals

Duplicate origin of left vertebral artery.

A verified case of duplicate origin of the left vertebral artery in association with a large aneurysm arising from the aortic arch immediately distal to the left subclavian artery is presented. An anomalous left vertebral artery arises directly from the aortic arch between the left common carotid and subclavian arteries, and joins with the normal left vertebral artery in the transverse foramen of the fifth cervical vertebra.

Aged

Autogenous internal iliac artery bypass in the surgical treatment of renovascular hypertension: a case report.

A 24 year old female with severe renovascular hypertension resulting from bilateral fibromuscular dysplasia was successfully treated surgically. The internal iliac artery was used for a left aortorenal grafts. The right renal artery was dilated through the amputated left renal stump. Although saphenous vein graft is most commonly used, the autogenous internal iliac artery is considered a satisfactory graft in aortorenal reconstruction, especially for a young patient.

Adult

Surgical treatment of juxtarenal aortic occlusion.

From 1974 to 1976, four patients with juxtarenal aortic occlusion were operated upon with no surgical mortality. Thromboendarterectomy (TEA) of the aorta with renal revascularization was performed in one patient, and TEA with grafting in three. Intraoperative renal protection was particularly important, since suprarenal aortic clamping was often required in these cases. Possible renal embolism developed in one patient postoperatively. In order to prevent renal embolism and to minimize ischemic insult to the kidney, the value of the following procedures was stressed; (a) irrigation of aortic lumen with saline after TEA under suprarenal aortic clamping with renal arteries kept occluded, and (b) re-application of aortic clamp below the renal arteries after irrigation. Since the most distal level of occlusive process was the common femoral artery in our series, the patient with this disease entity should be treated more actively.

Aged

Degenerative changes of vein grafts in preparation media: preliminary studies by electron microscopy and fibrinolytic autography.

Degenerative changes of saphenous vein grafts in four preparation media (heparinized whole blood at room temperature and 4 degrees C, and heparinized normal saline at same temperatures) were examined by scanning and transmission electron microscopy and fibrinolytic autography. Following 60--90 min. storage in heparinized normal saline at room temperature, marked morphological changes were present in the media, accompanied by swelling of the endothelial cells, however the tunica media and adventitia were well preserved even after 120 minutes in all of the four preparation media. The decrease in fibrinolytic activity was comparable to the observed morphological changes. In heparinized whole blood at 4 degrees C, degenerative changes were slow and mostly of a slight nature.

Autoradiography

Clinical significance of bradykinin liberation during cardiopulmonary bypass and its prevention by a kallikrein inhibitor.

Activation of the kinin system and effects of Trasylol (Bayer, A.G. Lebukusen, West Germany), a kallikrein inhibitor, were investigated on 52 patients during hemodilutional cardiopulmonary bypass (CPB). Immediately after the start of CPB, neither elevation of bradykinin nor reduction of plasma kininogen (KGN: a precursor of bradykinin) were observed. During CPB, bradykinin level in the blood was markedly elevated, correlating with the significant decrease of kininogen (p less than 0.001). The longer the CPB time, the more marked the reduction of KGN. In the cases requiring over 60 minutes of CPB, the amounts of bradykinin released (4.6-18.0ng/ml) were sufficient to increase capillary permeability as well as peripheral vasodilatation. As shown by the sufnificant increase of hematocrit (p less than 0.005) and the extreme reduction of vascular resistance found at the end of CPB in the prolonged cases. Infusion of Trasylol into the extracorporeal circuit actually prevented the reduction of kininogen and the increase of hematocrit as well as the extreme decrease of vascular resistance in the cases of over 60 minutes CPB. These results clearly point out that Trasylol is beneficial for the prevention of bradykinin liberation and capillary permeability increase and for the maintenance of optimum peripheral vascular tone during CPB. Furthermore, the significance of these findings with regards to complications during and after prolonged CPB was discussed.

Aprotinin

A role of extracorporeal circuit in the post-perfusion thrombocytopenia: a scanning electronmicroscopic observation.

Thrombocytopenia is one of the adverse effects of extracorporeal circulation (ECC) but the mechanism of which has not been fully understood. Blood-gas interface, mechanical agitation, rough surface of extracorporeal circuit and sequestration in the liver have been considered to be a cause of platelet loss. Extracorporeal circuit which provides large artificial surface for contact of blood has been blamed as the site of platelet destruction during oxygenation. However, the part of the oxygenator responsible for platelet loss has bot been located. This study was designed to identify the sites of extracorporeal circuit responsible for platelet loss during ECC with scanning electron microscopy (SEM) of the post-perfusion circuit. The accumulation of platelet aggregates was most pronounced at the defoaming net and blood filter where a sudden changes in velocity of blood flow take place. The aggregates were considered to be formed locally at these sites. However, there were no accumulation and/or adherence of platelet aggregates of significant degree at the other parts of the circuit, namely venous and arterial tubings, venous colum and arterial reservoir. Platelets seem to be removed from the circulation during each passage by defoaming net and blood filter. However the other parts of the circuit seem to be less blamed for the platelet loss. It was not possible to conclude whether the formation and trapping of platelet microaggregates at the defoaming net and blood filter or the destruction by oxygen bubbles is mainly responsible for the plateletloss during ECC.

Animals

Simplified operative technique for the long-segment atypical coarctation of the aorta.

Simplified operative technique for the long-segment atypical coarctation of the aorta was described. The main objective of this technique is to gain quick access to both thoracic and abdominal aorta with minimal blood loss, and preservation of diaphragmatic function. This procedure consists of standard thoracotomy and pararectal incision with an entry into the retroperitoneal space. Long prosthetic graft was anastomosed in an end-to-side fashion to bypass the coarctated aorta. The graft is placed through peripheral circumference of the left hemidiaphragm, where phrenic nerve injury is not likely to occur. This technique was successfully applied to two cases of long-segment atypical coarctation of the aorta due to Takayasu's aortitis. Retroperitoneal placement of the graft prevents fatal hemorrhage due to direct contact with the graft. Contamination with transintestinal exudate can also be avoided. Results of the ten-year follow-up of the similar procedure in the literature is encouraging.

Adult