Biomedical subjects
Publications and source records attributed to S Shindo.
Patent ductus arteriosus (PDA) in adults is occasionally associated with calcification and pulmonary hypertension, for which an anterior approach through a median sternotomy with cardiopulmonary bypass is often used. Sutures are placed without circulatory arrest by using a transpulmonary balloon catheter as an occluder. To secure the suture tie, we used Nélaton's catheters as tourniquets.
Intra-arterial hepatic chemotherapy via implantable reservoirs is being used increasingly. In our department, five patients have undergone emergency surgery since 1991 because of rupture of an infected pseudo-aneurysm at the site of entry of the catheter. Surgical procedures included removal of the catheter and the reservoir, and closure of the affected artery with or without reconstruction. Of these patients, three (60%) died from uncontrollable sepsis. The poor prognosis emphasizes the need, in patients with carcinoma, for strict aseptic technique and hemostasis at the time of catheter placement, and for careful device maintenance.
Abdominal aortic aneurysm with left-sided inferior vena cava (IVC) is rare. In preoperative examination, it is important to conduct roentgenologic studies and determine any venous anomalies. Proximal anastomosis is technically difficult because the IVC crosses to the right on the aneurysmal neck. In this case of a 71-year-old Japanese man, proximal anastomosis was conducted safely under wide vena cava mobilization and contraction in the superior direction. In vein resection, vessels should be reconstructed because vein communication is not methodical.
BACKGROUND: We have adopted an all-autogenous-vein-graft policy in carotid reconstruction for Takayasu arteritis, namely an ascendo-right carotid and right subclavian (axillary) arteries bypass using a pantaloon vein graft for patients all of whose arch branches are occluded, and an extra-anatomical bypass from the right subclavian artery for patients whose brachiocephalic artery is the only arch branch that remains patent. This report is to elaborate on these operations and to assess the long-term outcome. METHODS: Six patients were operated on according to this policy; (5 women, 1 man, age range: 14 to 59 years (mean: 30). The indications for surgery were severe cerebral ischaemia that significantly interfered with their daily lives. The pantaloon vein graft bypass was performed in four patients, and an extra-anatomical bypass in two. The specific management protocol to prevent the "postbypass hyperperfusion syndrome" and cerebral oedema included a shunt procedure to the internal carotid artery using one limb of the pantaloon vein graft, induced hypotension just before the completion of the carotid reconstruction and the administration of a glycerine-fructose solution. RESULTS: Cerebral ischaemic symptoms disappeared in all patients. All but one, who died of a ruptured thoraco-abdominal aneurysm on the 35th postoperative month, are living a normal life with a patent graft. No suture line complications have as yet been encountered (follow-up: 10 to 205 months, mean: 126 months). CONCLUSIONS: Carotid vein bypass for Takayasu arteritis, particularly, the pantaloon vein graft bypass is recommended for those of whom all aortic arch branches are occluded, resulting in severe brain ischaemia. Perioperative blood pressure control is important for prevention of the hyperperfusion syndrome.
OBJECTIVE: Atherosclerotic aneurysms in the aortic arch are associated with abdominal aortic aneurysms in up to 37% of cases. We have developed a single-stage approach to the repair of both aneurysms using a temporary bypass. SUBJECTS: Since November 1996, 5 patients underwent simultaneous repair of aneurysms in the aortic arch and in the infrarenal abdominal aorta, using a new temporary bypass graft technique. Entire arch replacement with simultaneous abdominal aortic aneurysmectomy was performed in one patient. The other 4 patients underwent distal hemi-arch replacement distal from the orifice of the brachiocephalic artery with simultaneous repair of the abdominal aortic aneurysm. METHOD: For the entire arch replacement procedure, blood flow to all major branches of the aortic arch was established using a bifurcated graft. This graft anastomosed to the ascending aorta was used as the proximal inflow of the temporary bypass graft. For the hemi-arch replacement procedure, the proximal inflow segment of the temporary bypass graft was anastomosed to the brachiocephalic artery. In both cases, the distal outflow segment of the temporary bypass graft was the graft used for repair of the abdominal aortic aneurysm. In order to prevent any clamp injury, Teflon felt was tightly wrapped around the aorta before the clamp was applied. RESULTS: Evaluation of the hemodynamic parameters measured during cross-clamping of the aortic arch revealed stable distal perfusion to the visceral organs and no excessive increase in cardiac afterload. All patients had an uneventful postoperative course and were discharged within 1 month of surgery. CONCLUSION: Our temporary bypass method is recommended for simultaneous replacement of aneurysms in the aortic arch and the abdominal aorta.
Anomalous anatomic location of a large venous system poses a potential hazard in aortic operations. We encountered a patient with an infrarenal abdominal aortic aneurysm who was also found at preoperative contrast-enhanced computed tomography to have a retrocaval right ureter and a preaortic iliac vein confluence. This combined anomaly has not previously been reported except for one postmortem case. As abdominal aortic surgery is currently performed routinely, care must be taken to avoid injury to surrounding organs due to rare anatomic anomalies.
The existence of human renin-binding protein (RnBP) in the kidney has been shown by the isolation and characterization of a complex of porcine renin-human RnBP [S. Takahashi et al. (1985) J. Biochem. 97, 671-677]. However, the properties of the free form of human RnBP had not been understood, because of the limitation of materials. In the present study, we have expressed human RnBP in Escherichia coli JM 109 cells under the transcriptional control of taq promoter and purified it by conventional column chromatographies. The purified recombinant human RnBP (rhRnBP) exists as a dimer and inhibits porcine renin activity through formation of a complex of porcine renin with rhRnBP, the so-called high-molecular-weight renin. Moreover, the rhRnBP catalyzes the interconversion between N-acetyl-D-glucosamine (GlcNAc) and N-acetyl-D-Mannosamine (ManNAc) with the apparent Km values of 21.3 mM for GlcNAc and 12.8 mM for ManNAc, and 0.13 mM for effector ATP. ATP is essential for the GlcNAc 2-epimerase activity of human RnBP. These results indicate that the human RnBP is a GlcNAc 2-epimerase.
Renin binding protein (RnBP) is a proteinous renin inhibitor firstly isolated from porcine kidney. Recently, the protein was identified as the enzyme, N-acetyl-D-glucosamine (GlcNAc) 2-epimerase. The GlcNAc 2-epimerase activity of recombinant human RnBP was specifically inhibited by SH-reagents such as N-ethylmaleimide, 5, 5'-dithiobis-2-nitrobenzoate, and iodoacetic acid, indicating that the most probable reactive site is a cysteine residue. To identify the active site residue(s), we have constructed ten cysteine residue mutants (C41S, C66S, C104S, C125S, C210S, C239S, C302S, C380S, C386S, and C390S) for human GlcNAc 2-epimerase and expressed them in Escherichia coli cells. The relative specific activities of C41S, C66S, C125S, C210S, C239S, C302S, C386S, and C390S are nearly the same to that of the wild-type enzyme. The specific activity of the C104S mutant is 26% of that of the wild-type enzyme. The expression of the C380S mutant in E. coli cells was detected on Western blotting, whereas GlcNAc 2-epimerase activity was not detected in the extract. These results indicate that Cys380 is essential for the enzymatic activity of human GlcNAc 2-epimerase.
Ossification of the posterior longitudinal ligament lessens the sagittal diameter of the cervical canal and compresses the spinal cord anteriorly, and may produce severe disabling myelopathy. The anterior floating method is one of the anterior decompression and reconstructions used in the treatment of cervical myelopathy caused by ossification of the posterior longitudinal ligament. This procedure consists of subtotal resection of vertebral bodies and discs, with slight thinning and release of the ossified ligament using air instrumentation. This is followed by reconstruction of the cervical spine using autogenous strut bone graft accompanied by postoperative application of a halo vest. This method is indicated for patients who present with moderate or severe myelopathies, and especially in those where the canal narrowing ratio exceeds 60%. This radical procedure causes decompression of the spinal cord and restores its function by enlarging the neural canal with anterior migration of the ossified ligament. The procedure minimizes the extent of surgical invasions and avoids damage to the neural tissue, because it does not require the removal of the ossification of the posterior longitudinal ligament. It also stops postoperative regrowth of the ossification. The operative results with long term followup indicate a 71% average recovery rate based on the criteria established by the Japan Orthopedic Association.
Thrombotic occlusion of the arteries and veins are categorized as acute and chronic presentations. Acute arterial occlusion results in severe ischemia because of poor or no development of the collateral arteries. They should be treated promptly by thrombectomy or thrombolysis. On the other hand, chronic arterial occlusion is preferably treated by bypass surgeries. Although the vascular surgeries in the chronic arterial occlusion have undergone remarkable development in the recent years, the treatment of acute occlusion still lags behind poor with prognosis. The treatment of acute venous occlusion is aimed to prevent postphlebitic syndrome except for the ischemic type such as venous gangrene. The purpose of the treatment of chronic venous occlusion is to assist the pump function of the calf muscles to avoid venous stasis. Pulmonary embolism is the most severe complication and its treatment remains controversial.
In the recent years, the vascular reconstructions are being performed regularly in patients with chronic arterial occlusion, while no remarkable advances are observed in cases with acute arterial deterioration. The poor results of the vascular surgeries for the acute arterial occlusion are mainly due to myonephropathic metabolic syndrome (MNMS). The thrombectomy which is performed by Fogarty's balloon catheter is the simplest technique and found to be useful in patients suffering from thromboembolism. But it should be applied carefully to avoid vascular injury. The surgical techniques have been remarkably improved especially in the area of tibial bypass surgery and endovascular surgery. The former has been achieved by tourniquet occlusion technique and the later by angioplasty with a metal stent.
One of the most conspicuous advances in vascular surgery during the past two decades has been the improvement of the patency of distal bypasses. The nondissection method, in particular, has made a great contribution to better the tibioperoneal bypass patency. This review describes the operative procedure and background of the method, in which only the vascular sheath of the recipient artery is exposed and circumferential dissection of the artery avoided. The limb is exsanguinated with an Esmarch's bandage, and haemostasis is maintained with a pneumatic tourniquet. Vascular clamps are not applied to the artery at the distal anastomotic site. In a series of 42 tibial bypasses, a primary revised patency of 84% has been achieved after five years with this method.
Takayasu's arteritis was originally described as a systemic inflammatory arterial disease presenting with occlusive changes. However, it has also been known to cause aneurysm formation. In this report, a patient with Takayasu's arteritis was found to have an aortoduodenal fistula. An emergency operation was carried out with resection of the saccular aneurysm and the fistula. The aorta was reconstructed with a prosthetic graft and the duodenum repaired. A pedicled omental flap was placed between the aorta and the duodenum. The postoperative recovery was uneventful, there was no evidence of persistent bleeding, and the patient was well at the 3-year follow-up. This is the first case in the English language literature of a primary aortoduodenal fistula treated successfully with surgery in a patient with Takayasu's arteritis.
Between June 1992 and May 1996, five patients underwent an abdominal aortic aneurysm (AAA) repair with concomitant arterial branch reconstruction. All of the patients were males ranging in age from 55 to 66 years (mean: 61.6 years). The operations were performed for a localized abdominal aortic dissection, a pseudoaneurysm after patch angioplasty of a supraceliac AAA, a pararenal AAA, a total AAA with retrograde descending thoracic aortic dissection, and a supraceliac AAA after an infrarenal AAA repair. All patients underwent bilateral renal artery (RA) reconstruction. Three patients also had a concomitant reconstruction of the superior mesenteric artery ad celiac axis. The renal arteries were preferentially reconstructed. Visceral circulation during aortic cross-clamping was maintained via a temporary bypass circuit. A temporary division of the left renal vein was necessary in two patients. Overall, the mean renal ischemia time was 17.2min (range: 10 to 32 min). There was one perioperative death due to sepsis from a graft infection. Another patient died 6 months postoperatively due to pyothorax. One patient required postoperative hemodialysis for 1 month. Based on the above findings, the temporary bypass technique is thus considered to be useful for maintaining physiologic organ perfusion during aortic clamping without the need to use any complicated devices.
It is suspected that operative injury to the native arteries during a vascular bypass procedure causes periarterial fibrosis contributing to late graft failure. A a nondissection method for tibial artery bypass has been developed using Esmarch's rubber bandage or an automatic sequential pneumatic tourniquet. This retrospective study examined patency and other late results in distal bypass operations using the nondissection method. Between June 1982 and July 1995, 78 tibial bypasses were performed using reversed autogenous saphenous vein grafts in 70 patients (57 men, 13 women; mean age 57.4 years). Graft patency was assessed angiographically. When a stenotic lesion was recognized, the graft was revised and considered an assisted primary patency. Primary patency rates at 1, 3, 5, and 10 years were 82.8%, 75.3%, 63.4% and 63.4%, respectively, by life-table analysis. Six grafts required revision for stenosis; one involved distal anastomotic stenosis. As a result, assisted primary patency rates resembled secondary patency rates of 87.7%, 84.3%, 80.3%, and 80.3% at the same respective intervals. In conclusion, the nondissection method improved long-term patency by preventing late distal anastomotic stenosis.
The role of apoptosis in glomerular cell depletion associated with a decrease in renal function is still controversial. To examine the involvement of apoptosis in renal disease, the occurrence of apoptosis during the progression of renal insufficiency as well as the expression of Bax protein and Fas antigen that are related to the apoptosis were investigated using five-sixths nephrectomized rats, one of the progressive renal disease models. Serum creatinine was significantly elevated to a level approximately five-fold higher than that in the sham-operated group on day 1 after the five-sixths nephrectomy and then maintained at a level approximately two- to three-fold higher until day 56 and then elevated further to a level eight-fold higher on day 96 after nephrectomy as compared with the sham-operated group. The total number of glomerular cells was significantly increased from day 7 to day 56 after nephrectomy and then returned to the level of the sham-operated group by day 96. The number of PCNA-positive cells (a marker of proliferating cells) in the glomeruli was significantly increased from day 7 to day 28 after nephrectomy; the highest level was observed on day 7, and the numbers then decreased gradually. Apoptotic cells, which were represented by TUNEL-positive cells, as well as apoptotic bodies were persistently increased with time after nephrectomy in the glomeruli of nephrectomized rats; apoptotic cells could hardly be observed in the sham-operated group. Therefore, glomerular cell proliferation appeared to begin immediately after nephrectomy and to continue until day 28 at a level high enough to overcome the decrease in the number of glomerular cells due to apoptosis, since the total number of glomerular cells was apparently high until day 56. On day 96, the decrease in the number of glomerular cells probably becomes predominant over cell proliferation, since apoptosis continuously increased with time after nephrectomy. The events on day 96 may be associated with the severely decreased renal function which was represented by the explosive increase in the serum creatinine level on the same day. The number of Fas antigen positive glomerular cells was increased from day 1 after nephrectomy and reached a plateau on day 21. The number of Bax protein positive glomerular cells was generally increased with time after nephrectomy, but the number was slightly decreased on day 21. The theory that the expression of Bax protein is correlated with apoptosis appears to fit the case of progressive renal disease. These results suggest that apoptosis is involved in the cell depletion of progressive renal insufficiency.
We have previously reported that Sairei-to (TJ-114), a Japanese herbal medicine, prevented the production of endothelin-1 in anti-GBM nephritic rats, and that Alismatis Rhizoma (Takusha in Japanese), one of the twelve herbs composing TJ-114, might be responsible for the action. In order to further clarify the antinephritic components of TJ-114, we investigated the effects of Takusha extracts on various parameters, including endothelin-1 production of glomeruli in vitro and in vivo using anti-GBM nephritic rats. MeOH-100% MeOH and MeOH-50% MeOH fractions (31.3 microgram/ml or higher) strongly inhibited an increase in endothelin-1 concentration in culture medium when they were added to a culture of glomerular cells derived from nephritic rats. In addition, oral administration of the MeOH-100% MeOH fraction (30 mg/kg) ameliorated the proteinuria, increase in systolic blood pressure and changes in histopathological parameters in nephritic rats. Oral administration of the MeOH-100% MeOH fraction inhibited increase in endothelin-1 expression in the glomeruli of nephritic rats and in endothelin-1 production by a culture of glomerular cells derived from the nephritic rats. Alisols A and B, the main constituents of the MeOH-100% MeOH fraction, inhibited in vitro endothelin-1 production by glomerular cells derived from the nephritic rats. Oral administration of alisol B (30 mg/kg) prevented the endothelin-1 expression by glomeruli and the increase in endothelin-1 production by cultured nephritic glomerular cells. Oral administration of alisol B also ameliorated the proteinuria, the increase in systolic blood pressure and the changes in histopathological parameters in the nephritic rats. These results indicate that the antinephritic action of TJ-114, resulting from the inhibition of endothelin-1 production, may be attributed to the alisols in Takusha.
Delayed manifestation of aortic stenosis caused by abdominal blunt trauma is rare. We report herein the case of a 67-year-old man who was taken to a nearby hospital after being crushed between a heavy truck and a wall. An emergency laparotomy was performed, revealing only a mesenteric tear which was repaired. He was discharged after an uneventful postoperative course; however, 1 month later he began to experience intermittent claudication, and presented to our hospital in December 1994, 1 year after the first operation. Angiography and enhanced computed tomography (CT) demonstrated infrarenal abdominal aortic dilatation with distal stenosis. Both the dilated and stenotic lesions were resected and bypass surgery ws performed. Pathologic examination demonstrated that the intima had been lacerated circumferentially and everted distally, causing the aortic stenosis. To our knowledge, this is the first case of the delayed manifestation of traumatic aortic stenosis to be documented in Japan. The etiology of this rare complication of blunt trauma is described in this report.