Biomedical subjects

N Nishikimi

Publications and source records attributed to N Nishikimi.

At least 19 recordsLinked to original sources

PubMed2000

Neutrophil and endothelial cell activation in the vasa vasorum in vasculo-Behçet disease.

AIM: The aim of this study was to analyse the immunopathological mechanisms of vasculo-Behçet disease, which were also compared to cases of Takayasu's arteritis and inflammatory aneurysm to evaluate differences in inflammatory mechanisms. METHOD AND RESULTS: We reviewed six cases of vasculo-Behçet disease, four of Takayasu's arteritis and seven inflammatory aneurysms which underwent surgical repair. Immunohistochemical studies were performed on paraffin-embedded tissue using a labelled streptavidin-biotin method, as was in-situ hybridization for Epstein-Barr virus. Microscopically, neutrophils and lymphocytes accumulated around the vasa vasorum. Neutrophils were prominent as compared to Takayasu's arteritis and inflammatory aneurysm. Elastic fibres were not severely destroyed. Endothelial cells (ECs) of most vasa vasorum expressed HLA-DR. The number of vasa vasorum around which inflammatory infiltrating cells were observed in vasculo-Behçet disease was significantly greater than in inflammatory aneurysms and Takayasu's arteritis (P < 0.001). The cytokines IL-1alpha, TNF-beta and IFN-gamma were expressed in neutrophils and lymphocytes which were distributed around vasa vasorum, as well as neutrophils adherent to HLA-DR positive ECs. CONCLUSION: Our results suggest that vasculo-Behçet disease should be classified as a neutrophilic vasculitis targeting the vasa vasorum. Aneurysm formation may be related to degeneration of arterial wall caused by inflammation of the vasa vasorum.

Adolescent↗

PubMed2000

Intestinal permeability is increased in patients with intermittent claudication.

PURPOSE: Intermittent claudication can be regarded as repeated ischemia reperfusion injury, which can induce a generalized increase in vascular permeability, including in intestine. The lactulose mannitol test (L/M test) was performed in patients with intermittent claudication to evaluate the change in intestinal permeability when they were forced to walk. METHODS: The L/M test was performed in 11 patients with intermittent claudication and 11 control subjects without intermittent claudication. The test was performed at rest and after exercise. Patients walked on a treadmill until they stopped because of pain. The control subjects were forced to walk as far as 200 m on a treadmill. The L/M test was repeated in the patients after successful arterial reconstruction. Then the patients were instructed to walk the same distance at the same speed as they had before surgery. RESULTS: In patients, the mean L/M ratio after exercise was significantly higher than the mean L/M ratio when they were at rest (0.068 +/- 0.053 vs 0.022 +/- 0.009, P <.05). In control subjects, however, no significant difference was observed between the mean L/M ratios after exercise and at rest. The mean L/M ratio after exercise, decreased from 0.068 +/- 0.053 to 0.018 +/- 0. 016 after successful arterial reconstruction (P <.05) in patients. CONCLUSION: Intestinal permeability, determined by means of the L/M test, significantly increased in patients with intermittent claudication after exercise, and it diminished after arterial reconstruction. The L/M test is, consequently, a new noninvasive method to reflect ischemia in lower limbs during exercise.

Aged↗

PubMed2000

Pseudoaneurysm of the popliteal artery caused by exostosis of the femur: case report and review of the literature.

A 13-year-old boy with a solitary exostosis of the left femur was seen with a pseudo-aneurysm of the popliteal artery. When left leg pain occurred 3 months earlier, radiographic examination revealed an exostosis with a cartilage cap. Serial radiographic examination demonstrated gradual disruption of the cartilage cap of the exostosis as the pseudoaneurysm developed. An exostosis with an irregular surface was found at surgery. A literature review disclosed 39 similar cases in which loss of the cartilage cap was considered as one of the causes of the aneurysm formation. Considering the clinical course of our patient, however, we believe that exostoses lose their cartilage caps by pressure destruction due to the aneurysms. It is highly probable that loss of the cartilage does not cause the aneurysms.

Adolescent↗

PubMed2000

Endovascular stent-graft deployment: temporary vena caval occlusion with balloons to control aortic blood flow-experimental canine study and initial clinical experience.

Vena caval occlusion was evaluated in animal experiments. In five patients with thoracic aortic aneurysms, two balloon catheters were introduced via the femoral vein to the inferior vena cava and superior vena cava and inflated before stent-graft deployment. Aortic pressure and flow were immediately decreased, which minimized the downstream shift of the stent-grafts. Temporary vena caval occlusion is safe and effective for precise aortic stent-graft deployment.

Aged↗

PubMed1999

Immunohistochemical analysis of arterial wall cellular infiltration in Buerger's disease (endarteritis obliterans).

PURPOSE: The diagnosis of Buerger's disease has depended on clinical symptoms and angiographic findings, whereas pathologic findings are considered to be of secondary importance. Arteries from patients with Buerger's tissue were analyzed histologically, including immunophenotyping of the infiltrating cells, to elucidate the nature of Buerger's disease as a vasculitis. METHODS: Thirty-three specimens from nine patients, in whom Buerger's disease was diagnosed on the basis of our clinical and angiographic criteria between 1980 and 1995 at Nagoya University Hospital, were studied. Immunohistochemical studies were performed on paraffin-embedded tissue with a labeled streptoavidin-biotin method. RESULTS: The general architecture of vessel walls was well preserved regardless of the stage of disease, and cell infiltration was observed mainly in the thrombus and the intima. Among infiltrating cells, CD3(+) T cells greatly outnumbered CD20(+) B cells. CD68(+) macrophages or S-100(+) dendritic cells were detected, especially in the intima during acute and subacute stages. All cases except one showed infiltration by the human leukocyte antigen-D region (HLA-DR) antigen-bearing macrophages and dendritic cells in the intima. Immunoglobulins G, A, and M (IgG, IgA, IgM) and complement factors 3d and 4c (C3d, C4c) were deposited along the internal elastic lamina. CONCLUSION: Buerger's disease is strictly an endarteritis that is introduced by T-cell mediated cellular immunity and by B-cell mediated humoral immunity associated with activation of macrophages or dendritic cells in the intima.

Adult↗

PubMed1999

Implantation of an endovascular covered stent-graft for distal aortic arch aneurysm via midsternotomy under pigtail catheter guidance.

We implanted an endovascular covered stent-graft for distal aortic arch aneurysm involving the left subclavian artery in 12 cases. A stent-graft was delivered just below the aneurysm via aortotomy with direct vision using a 12 F delivery sheath under guidance of a pigtail catheter placed via the groin artery. The proximal anastomosis of the stent-graft was performed with inclusion technique, and the aortotomy was then closed with it. This technique reduces operative damage by eliminating distal anastomosis and should reduce operative mortality and morbidity.

Adult↗

PubMed1999

A rabbit model of abdominal aortic aneurysm associated with intimal thickening.

A model of abdominal aortic aneurysm with intimal thickening was developed in the rabbit. A segment of the abdominal aorta just proximal to the bifurcation (1 or 2 cm in length) was dissected and isolated with clamps. This segment was perfused by injecting physiologic saline or 100 U/ml of hog pancreatic elastase from the lumen. Perfusion was performed manually for 5 min and the peak pressure in the segment was between 300 and 400 mm Hg in order to cause aortic wall injury. After 4 weeks, animals that had received perfusion with elastase had aneurysms in the perfused segment on arteriography. None of the other animals developed aortic aneurysms. Histologically, the segments of aorta perfused with saline exhibited intimal hyperplasia. In addition to the intimal hyperplasia, the segments of aorta perfused with elastase solution showed lysis of the elastic lamellae in the media that resulted in aneurysm formation.

Animals↗

PubMed1999

[Preprocedural and procedural imaging modalities for transluminally placed endovascular grafting].

The vascular system can be evaluated with computed tomography (CT), magnetic resonance angiography (MRA), angiography, and computer-based CT image processing systems before successful transluminally placed endovascular grafting (TPEG). Noninvasive modalities are useful, but angiography is mandatory to determine whether TPEG is indicated. During the procedure, fluorography with a wide-image intensifier and high-resolution digital subtraction angiography are known to be essential, but intravascular ultrasonography is also indispensable to achieve accurate TPEG.

Aortic Aneurysm↗

PubMed1998

Vena cava occlusion with balloon to control blood pressure during deployment of transluminally placed endovascular graft.

Transluminally placed endovascular graft (TPEG) replacement has been applied to treat various aortic diseases. At the moment of deployment, TPEG receives a pressure pulse force to shove it distally, which possibly results in misplacement. Moreover, deploying the TPEG in the aorta increases cardiac afterload, which may damage myocardial function. To avoid these risks, we developed a new technique to control blood pressure by almost complete venous return occlusion. Two occlusion balloon catheters are inserted into the superior and inferior vena cava via the femoral vein. TPEG is deployed at the proper position during inflation of the vena cava balloon to maintain a blood pressure as low as 60 mm Hg by cardiac preload blockage. We, thus far, have not experienced even a trivial sequela with this technique.

Aortic Diseases↗

PubMed1998

Aortic stump closure with a titanium permanent clamp: a useful emergency method.

Successful aortic stump closure in a patient with Behçet's disease was accomplished with a permanent titanium clamp. In May 1990, a saccular infrarenal abdominal aortic aneurysm was detected in this patient, and prosthetic graft replacement was carried out. One year later, this graft was removed because of perigraft fluid collection; the aortic stump was sutured closed, and a right axillobifemoral bypass was done. In November 1994, the patient was admitted to the hospital because of an aortoenteric fistula. An emergency operation was performed, and the aortic stump was managed successfully with a permanent clamp. In patients with Behçet's disease, use of a permanent clamp may offer an alternative to traditional methods for closing blown-out aortic stumps.

Anastomosis, Surgical↗

PubMed1998

Correlation of the anatomical distribution of venous reflux with clinical symptoms and venous haemodynamics in primary varicose veins.

AIM: The aim of this study was to correlate the anatomical distribution of venous reflux with clinical symptoms and venous haemodynamics in patients with primary varicose veins. METHODS: Venous reflux was examined using duplex colour Doppler ultrasonography in 266 legs in 191 patients. The venous refilling and reflux times were also measured. RESULTS: Of the 266 legs, 82 per cent had reflux in the long saphenous vein (LSV), 26 per cent in the short saphenous vein (SSV), 62 per cent had incompetent perforators (IPs) in the calf and 48 per cent had reflux in the deep veins. LSV reflux combined with SSV reflux and/or IPs was associated significantly with severe venous disease and abnormal venous haemodynamics. Femoropopliteal reflux played a role in the development of venous eczema and ulcers when combined with superficial venous reflux. CONCLUSION: Patients at high risk of developing complications of venous disease may be identified by an accurate non-invasive evaluation of reflux patterns.

Adolescent↗

PubMed1998

Attenuation of renal ischemia-reperfusion injury in rats by allopurinol and prostaglandin E1.

50 Sprague-Dawley rats were used to study the effect of allopurinol and prostaglandin E1 (PGE1) on renal ischemia-reperfusion injury. They underwent left renal ischemia for 1 h and reperfusion. A right nephrectomy was performed, and 5 groups were made. Group AP received allopurinol 50 mg/kg and PGE1 20 micrograms/kg; group A, allopurinol; group P, PGE1; group C, control, and group S, sham group. Five animals from each group were used to study renal functions and 5 for renal histology. The serum creatinine values were lower in the treatment groups compared to the controls on days 1-3 and 7 (p < 0.05). The blood urea nitrogen values showed a similar trend. Maximum histological damage was seen in group C, followed by groups A, P and AP, in this order. We conclude that allopurinol and PGE1 attenuate renal ischemia-reperfusion injury in rats.

Allopurinol↗

PubMed1998

Decrease in prevalence of Buerger's disease in Japan.

BACKGROUND: Buerger's disease is a peripheral arterial occlusive disease that is becoming rare in Western countries but is more common in Asia. Whether it is a specific disease entity remains controversial. This study was undertaken to investigate changes in the prevalence and characteristics of Buerger's disease at a major institution in Japan. METHODS: Patients with Buerger's disease admitted to Nagoya University Hospital between January 1985 and December 1996 were studied retrospectively. Buerger's disease was diagnosed on admission according to Shionoya's clinical criteria. RESULTS: A total of 105 patients with Buerger's disease were evaluated on 126 admissions; 58 were new patients who were admitted for initial treatment, and 47 patients were experiencing a worsening of Buerger's disease and had a history of prior treatment. Forty-six new patients were admitted between 1985 and 1989, but only 12 new patients were admitted between 1990 and 1996 (9 +/ 3/ yr vs 2+/ 2/ yr, p = 0.0003). Between 1985 and 1989, 44 patients were admitted because of disease exacerbation, whereas only 24 such admissions occurred between 1990 and 1996 (9+/ 3/ yr vs 3 +/ yr, p = 0.0137). The number of admissions for atherosclerotic peripheral vascular disease did not change significantly in that period. Of the 105 patients, the majority (96%) were men; mean age at the time of disease onset was 36 +/ 8 years. The chief complaint on admission was gangrene/ulcer in 64%, rest pain in 13%, foot claudication in 6%, calf claudication in 6%, and other in 10%. CONCLUSION: The prevalence of Buerger's disease appears to be decreasing at our institution in Japan. Its clinical characteristics have not changed. A similar decrease in prevalence appears to have occurred in Western countries.

Adult↗

PubMed1998

Iontophoretic application of prostaglandin E1 for improvement in peripheral microcirculation.

OBJECTIVE: The pharmacological effects of iontophoretically applied prostaglandin E1 (PGE1) on the peripheral microcirculation were investigated. MATERIAL AND METHOD: PGE1 concentrations permeated through hairless mouse skin iontophoretically were measured by HPLC at hourly intervals. 19 patients with arteriosclerosis obliterans were given PGE1 (20 microg) iontophoretically on the dorsum of the foot. As a control, normal saline was applied iontophoretically on another day. The increase rate in cutaneous blood flow as measured by laser Doppler flux (LDF) level was investigated. 5 of these 19 patients received PGE1 (20 microg) solution intravenously on another day. The increase rate in cutaneous blood flow as measured by laser Doppler flux (LDF) level was compared between iontophoresis and intravenous drip infusion. RESULT: PGE1 was transported across hairless mouse skin with iontophoresis in a time-dependent manner, while it did not permeate by passive transport. The percent increase in LDF level was significantly higher in the PGE1 group than in the control group(32.7+/-20.2% vs. 10.3+/-15.5%, p.001). The percentual increase in LDF level was significantly higher with iontophoresis than with intravenous drip infusion (43.7+/-19.5% vs. 11.7+/-28.3%, p < 0.05). CONCLUSION: The results indicated that iontophoretically applied PGE1 was effective in improving the impaired microcirculation due to peripheral arterial occlusive disease. This technique may be useful in managing severely ischemic legs.

Alprostadil↗

PubMed1997

Up-regulation of integrin beta 3 expression by cyclic stretch in human umbilical endothelial cells.

The effect of uni-axial cyclic mechanical stretch on the expression of the adhesion protein integrin was investigated. Human umbilical endothelial cells (HUVECs) cultured on fibronectin coated silicon membranes were subjected to uni-axial cyclic stretch. The level of expression of integrin beta 3 mRNA was found to be increased and peaked at 4 hours in response to cyclic stretch using a semiquantitative RT-PCR method. The increased level of the integrin mRNA from stretched HUVECs remained higher than that from non-stretched controls. The amount of integrin beta 3 also increased and peaked at 12 hr. Immuno-fluorescent microscopy revealed that the amount of integrin beta 3 adhesions increased in stretched HUVECs compared with that in non-stretched HUVECs. These results suggest that uni-axial cyclic stretch up-regulates the expression of integrin beta 3. This increase in integrin beta 3 may enhance the adhesiveness to the substratum and contribute to the protection of HUVECs against being peeled off from the vessel wall.

Antigens, CD↗

PubMed1997

Subcutaneous tissue distribution of vancomycin from a fibrin glue/Dacron graft carrier.

We investigated the tissue distribution of vancomycin (VCM) incorporated in fibrin glue (FG) in a rat model. One VCM-loaded FG Dacron graft (VCM-FG, VCM 0.6 mg/ graft) was implanted in the subcutaneous tissue of the anterior abdominal wall of each rat. VCM was injected intravenously at an equal dose (0.6 mg/rat) after implantation of one control graft (without VCM-FG). After the implantation and the iv injection of an equal dose of VCM (0.6 mg/rat), the tissue distribution of VCM for up to 24 h was determined through analysis of the implanted VCM-FG grafts, which released VCM over a 24 h period. The area under the VCM concentration-time curve (AUC) of the tissue was 89.58 micrograms.h/g after the implantation of the VCM-FG graft, and 7.40 micrograms.h/g after the iv injection of VCM, respectively. The targeting index of the tissue, defined as the ratio of AUC after the implantation of the VCM-FG graft to that after VCM iv injection, was 12.11. None of the six VCM-FG Dacron grafts after implantation became infected following inoculation with S. aureus ATCC 25923 (0.1 mL 10(8) CFU/mL). These results suggest that this VCM-FG Dacron graft delivery may be useful in preventing local infection by enhancing the delivery of VCM to the local areas of the implanted site in rats.

Animals↗

PubMed1997

Measurement of spinal cord blood flow by an inhalation method and intraarterial injection of hydrogen gas.

PURPOSE: This study was performed to determine spinal cord blood flow using the H2 clearance method. METHODS: In 12 dogs we measured blood flow determined by hydrogen clearance techniques (BF) in both gray and white matter by spinal cord puncture, and compared the results with BF measured by a catheter inserted intrathecally to avoid spinal cord injury. We studied direct intraarterial and intravenous injection of hydrogen in addition to the inhalation method because hydrogen is an explosive gas. RESULTS: BF measured intrathecally with catheters adherent to either the ventral or the dorsal funiculus did not differ significantly from that of the gray matter. BF measured with a catheter inserted into the epidural space was about one fourth of the BF measured intrathecally. Values measured by the intraarterial injection method did not differ significantly from those obtained by the inhalation method. CONCLUSIONS: BF measured with a catheter inserted intrathecally reflects blood flow in the gray matter of the spinal cord. Using intraarterial injection of H2, BF was safety and accurately measured while avoiding the risk of explosion.

Administration, Inhalation↗

PubMed1997

Hemodynamic assessment of femoropopliteal venous reflux in patients with primary varicose veins.

PURPOSE: The aim of this study was to assess the anatomic distribution and extent of deep venous reflux in patients with primary varicose veins (PVVs) and to investigate its influence on venous hemodynamics. METHODS: Femoropopliteal venous reflux was examined using duplex color Doppler ultrasonography in 356 limbs with PVVs in 240 patients. Photoplethysmography (PPG) was performed using above-knee and below-knee tourniquets to determine the contributions of deep and superficial venous insufficiency. RESULTS: Of 356 limbs with PVVs, 61 (17.1%) had femoropopliteal venous reflux, 42 (11.8%) had superficial femoral venous reflux alone, and 57 (16.0%) had popliteal venous reflux alone. Femoropopliteal venous reflux was associated significantly with clinical symptoms and shortened the half venous refilling time measured by PPG, especially in the presence of incompetent perforating veins. These findings were obtained regardless of the presence of long saphenous vein reflux. CONCLUSIONS: Femoropopliteal venous reflux associated with PVVs plays an important role in the pathophysiologic mechanism of venous stasis and influences venous hemodynamics in the presence of incompetent perforating veins and short saphenous vein.

Adolescent↗