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N Zempo

Publications and source records attributed to N Zempo.

At least 73 records · Page 4Linked to original sources
PubMed1996

Regulation of vascular smooth muscle cell migration and proliferation in vitro and in injured rat arteries by a synthetic matrix metalloproteinase inhibitor.

Smooth muscle cell (SMC) migration and proliferation and extracellular matrix remodeling are essential aspects of the arterial response to injury, vessel development, and atherogenesis. Matrix metalloproteinase (MMP) expression is associated with SMC proliferation and migration after arterial injury. To assess the role of MMPs in SMC proliferation and migration and intimal thickening, we measured the effect of the synthetic MMP inhibitor BB94 (Batimastat) on DNA synthesis and migration of SMCs in vitro as well as the formation of a neointima after balloon injury to the rat carotid artery. BB94 dose-dependently inhibited SMC migration induced by platelet-derived growth factor (PDGF)-BB through a filter coated with a thick basement membrane matrix (Matrigel) layer but did not show any inhibitory effect on SMC migration through a lightly coated filter. At concentrations up to 1 mumol/L, BB94 did not alter DNA synthesis induced by PDGF-AA or PDGF-BB. Treatment with 30 mg BB94.kg-1.d-1 IP for 7 or 14 days after balloon injury to the rat carotid artery decreased the total number of intimal SMC nuclei and suppressed intimal thickening. SMC proliferation (5-bromo-2'-deoxyuridine labeling) was decreased in the media at 2 days, whereas it was increased in the intima at 7 but not 14 days. These results suggest that BB94 inhibits intimal thickening after arterial injury by decreasing SMC migration and proliferation and support the conclusion that MMPs play a significant role in regulating intimal thickening in injured arteries.

Animals↗
PubMed1996

[Surgical treatment for ruptured aneurysm of distal arch or aortic arch: report of three cases].

We experienced three cases of surgery for ruptured aneurysm of the distal aortic arch (2 cases) or aortic arch (1 case). A 59-year-old man who was diagnosed as distal arch aneurysm ruptured to the pericardial cavity underwent graft replacement of the aneurysm and reconstruction of a left subclavian artery under selective cerebral perfusion (SCP). This patient had left hemiplegia postoperatively. A 73-year-old man who was diagnosed as an aneurysm of distal arch and descending aorta ruptured to left pleural cavity underwent graft replacement of the aneurysm and reconstruction of a left subclavian artery under SCP, and died of severe left ventricular failure possibly due to preoperative myocardial ischemia. A 70-year-old man who was diagnosed as a saccular aneurysm of aortic arch ruptured to mediastinum underwent resection of the aneurysm and patch plasty of the aorta under SCP. The postoperative course was uneventful. We discussed the approach to aneurysm, adjunctive method and surgical precedures from standpoint of our ruptured three cases.

Aged↗
PubMed1996

[An approach to the emergency surgery for arch and/or ascending aortic aneurysm].

The outcome of emergency surgery for the aortic arch aneurysm and/or dissecting aneurysm is worse than that of elective surgery. To decide the future strategy of the emergency surgery for these disease, 11 patients with emergency surgery (= group E: 8 for aortic dissection and 3 for rupture of the aortic arch aneurysm, age; 61 +/- 13 SD) were compared with 12 patients who had elective surgery (= group S: 5 for aortic dissection and 7 for aortic arch aneurysm, age; 69 +/- 3 SD). Ascending aorta replacement was performed in 7 cases in group E v.s. 1 in group S, aortic arch replacement in 2 v.s. 5, ascending aorta and aortic arch replacement in 1 v.s. 4 and patch replacement of the aortic wall in 1 v.s. 2, respectively. Selective cerebral perfusion (SCP) upon the cardiopulmonary bypass (CPB) was used in 45% (5/11) in group E. v.s. in 92% (11/12) in group S, p < 0.05. CPB time, aortic clamp time and SCP time were not significantly different between E group and S group. Postoperative cardiac failure, respiratory failure, renal failure, brain injury and infection occurred at insignificant rates between both groups. Thirty-day and 3-year survivorships were 73% in group E, while in group S they were 92% and 75%, respectively. In group E there were 2 cases which had aortic wall injury due to the aortic clamp used during the surgery. We recommend the use of selective cerebral perfusion and open distal anastomosis in emergency surgery for aortic arch aneurysm and/or Stanford type A aortic dissection.

Aged↗
PubMed1994

Matrix metalloproteinases of vascular wall cells are increased in balloon-injured rat carotid artery.

PURPOSE: Although matrix metalloproteinase (MMP) expression has been correlated with proliferation and migration of various tumor cells, the relation between MMP expression and smooth muscle cell (SMC) proliferation and migration has not been established. METHODS: We measured MMP expression (gelatin, casein, and elastin zymography) by vascular wall cells in balloon-injured carotid artery during the period of medial SMC proliferation, migration of SMC from the media to the intima, and subsequent intimal SMC proliferation. RESULTS: The 72 and 64-kd gelatinases (presumably 72 kd type IV collagenase or MMP 2) were constitutively expressed in normal carotid arteries, and the activated (59 and 54 kd) forms of this enzyme were increased at 5 days when SMCs start to migrate. A 92 kd gelatinase (presumably 92 kd type IV collagenase or MMP 9) was increased at 24 hours, when SMCs entered the growth cycle, and decreased thereafter. A low-molecular-weight metalloproteinase with elastolytic activity was present in the adventitia, and the activity was increased at 5 days after surgery. CONCLUSIONS: These results suggest that the 72 kd and 92 kd gelatinases may be involved in basement membrane and matrix degradation in the media in relation to SMC proliferation and migration, whereas the low-molecular-weight metalloproteinase may have a role in elastin turnover in the adventitia.

Animals↗
PubMed1994

Smooth muscle cell migration and matrix metalloproteinase expression after arterial injury in the rat.

We have characterized matrix metalloproteinase expression in the rat carotid artery after two forms of arterial injury, balloon catheter denudation and nylon filament denudation. Gelatinolytic enzymes with molecular masses of 70 and 62 kD were produced constitutively in the rat carotid. Production of an 88-kD gelatinase was induced after balloon catheter injury, and proteinase production continued during the period of migration of smooth muscle cells from the media to the intima, from 6 hours to 6 days after balloon catheter injury. In addition, a marked increase in 62-kD gelatinolytic activity was observed between 4 and 14 days after arterial injury. Gelatinase activities (88 and 62 kD) were also increased after nylon filament denudation but were markedly less after this injury than after balloon catheter injury. These results suggested a correlation between gelatinase activity and smooth muscle cell migration after arterial injury. Administration of a metalloproteinase inhibitor after balloon catheter injury resulted in a 97% reduction in the number of smooth muscle cells migrating into the intima. Therefore, we hypothesize that gelatinase expression directly facilitates smooth muscle cell migration within the media and into the intima. These results suggest that gelatinases are involved in the vascular smooth muscle cell activation and neointimal formation that characterize arterial tissue remodeling after injury.

Animals↗
PubMed1993

Sequential bypass for multisegmental occlusive disease.

We evaluated the effectiveness of a sequential bypass for multisegmental occlusive disease. Forty-seven multiple bypass grafts were performed on 43 patients ranging in age from 55 to 83 years (mean: 70 years). The indications for operation included incapacitating claudication in 20 limbs, resting pain in 15, and nonhealing ulcers in 12. An anatomical arterial bypass was performed on 36 limbs, consisting of an aorto-femoro-popliteal bypass in 21 limbs, a femoro-popliteal-posterior tibial bypass in 8, an ilio-femoro-popliteal bypass in 4, an ilio-femoro-posterior tibial bypass in 2, and a femoro-popliteal-plantar bypass in 1. Similarly, an extra-anatomical arterial bypass was performed on 11 limbs, consisting of an axillo-femoro-popliteal bypass in 6, a crossover femoro-femoro-popliteal bypass in 3, an axillo-femoro-posterior tibial bypass in 1, and a crossover femoro-femoro-anterior tibial bypass in 1. The follow-up period ranged from 3 to 77 months (mean: 23 months). Twelve graft failures occurred, and 2 of them required major amputations. The cumulative graft patency rate was 85% at one year and 65% at 3 years. Arterial Doppler examination revealed a mean preoperative ankle-brachial index of 0.29 +/- 0.25. The early and late mean postoperative ankle-brachial indices, however, increased to 0.97 +/- 0.19 and 0.84 +/- 0.25, respectively. Midterm results have indicated that such multiple sequential bypass grafts are effective.

Aged↗
PubMed1993

Arterial reconstruction in elderly patients.

The surgical results of primary peripheral arterial reconstruction for arteriosclerosis obliterans during a 16-year period were examined as a function of age. Data in group 1 were of 121 procedures performed on 95 patients aged > or = 70 years and those in group 2 of 215 procedures performed on 148 patients aged < or = 69 years. There was no significant difference between the operative mortality rate of 4% (four of 95) in group 1 and 3.4% (five of 148) in group 2. The long-term mortality rate was 33% (31 of 95) in group 1, significantly higher (P < 0.05) than 18.9% (28 of 148) in group 2. The most common cause of death in both groups was cardiac failure. Cumulative 5-year survival rates in groups 1 and 2 were 56.3 and 78.3% respectively (P < 0.0001). The cumulative primary 5-year patency rates of suprainguinal bypass grafts in the two groups were 94.2 and 90.4%, respectively, while those of infrainguinal reconstruction were 67.7 and 55.0% respectively. The 5-year cumulative limb salvage rate was 93.1% in group 1 and 92.7% in group 2. None of these differences was significant. The results support an active approach to surgery in elderly patients with peripheral arterial obstruction caused by arteriosclerosis obliterans.

Adult↗
PubMed1992

Sutureless anastomosis of blood vessels using cyanoacrylate adhesives.

On the assumption that the remaining suture threads of the anastomotic line play an important role in the progression of anastomotic neointimal hyperplasia, we performed an experimental study on the sutureless anastomosis of blood vessels. An expanded polytetrafluoroethylene graft, 5 mm in diameter and 2 cm in length, was implanted on the abdominal aorta of mongrel adult using one of three methods of anastomosis, namely; a continuous suture, a stay suture, or sutureless anastomosis. Overall patency rates were 83.3 per cent, 91.7 per cent and 75.0 per cent respectively. The thickness of the pannus in the distal anastomotic line after 12 months was 107 microns in one graft in the continuous suture group, 106 microns and 222 microns in 2 grafts each in the stay suture group, and 41 microns and 117 microns in 2 grafts each in the sutureless group. Because there were cases of patency even after 12 months with a very small pannus thickness, sutureless anastomosis is considered to be a useful method of preventing anastomotic neointimal hyperplasia.

Anastomosis, Surgical↗
PubMed1992

[Cystic disease of right popliteal artery with spontaneous resolution].

The case was 50-year-old man. He was admitted to our hospital suffering from intermittent claudication. DSA and CT showed stenosis of the right popliteal artery due to compression by the tumor like lesion. The adventitial cystic disease was suggested. Three weeks later he had no symptom. DSA and CT revealed no reappearance of the adventitial cystic disease. The popliteal adventitial cyst spontaneously decreased in size. It is a very rare case.

Angiography, Digital Subtraction↗
PubMed1992

Effect of prostaglandin I2 analogue TRK-100 on the suppression of intimal fibrous proliferation.

This study investigated the effect of prostaglandin I2 analogue (TRK-100) on the healing of arterial anastomoses. The infrarenal abdominal aorta was divided and reanastomosed immediately in rabbits. A control group of rabbits were fed commercial rabbit food (ORC 4); a cholesterol group of rabbits were fed a diet with 1% cholesterol added to ORC 4; and a TRK group of rabbits received the same diet as the cholesterol group, but TRK-100 was given subcutaneously at a dose of 0.3 mg (TRK-I group) or 1.0 mg (TRK-II group) every other day. After 3 months a blood sample was taken for biochemical analysis, and the abdominal aorta was harvested for histologic examination. The serum lipid and thromboxane B2 concentrations and the thromboxane B2/6-keto prostaglandin F1 alpha ratio in the TRK groups were significantly lower than in the cholesterol group. The proliferative connective tissue did not cover the anastomotic suture line in either the control or the TRK groups. However, the suture line was covered completely by connective tissue in the cholesterol group. Intimal thickness in the cholesterol group was greater than in either the control or the TRK-II group (p less than 0.01 and p less than 0.05, respectively). These data suggest that TRK-100 may suppress intimal fibrous proliferation at anastomotic suture lines by a mechanism affecting the thromboxane B2/6-keto prostaglandin F1 alpha ratio.

Analysis of Variance↗
PubMed1992

[99mTC-HSA lymphoscintigraphy and leg edema after arterial reconstruction].

To investigate the etiology of lower limb edema after arterial reconstruction, 12 patients (16 limbs) who underwent arterial reconstruction due to atherosclerosis obliterans were observed. There was no relationship between the severity of limb edema and serum factors (serum total protein, albumin, BUN and creatinine), ankle/brachial arterial pressure ratio, peripheral venous pressure or RI lymphoscintigraphy in the supine position. The lymphatic flow in RI lymphoscintigraphy at 3-4 weeks after operation increased with statistically significant difference compared to the preoperative flow whether the patient was in the supine or upright position. Though there was no significant relationship between the severity of leg edema and postoperative lymphatic flow in the supine position, postoperative lymphatic flow in the upright position decreased as the severity of leg edema increased. Increased lymphatic flow in the follow-up period was associated with increased severity of leg edema in the upright position. It is concluded that postoperative leg edema is due to the damage to the lymphatic vessels during operation, and then the lymphatic channels cannot adapt to the increased lymphatic flow after the arterial reconstruction.

Aged↗
PubMed1991

Eicosapentanoic acid suppresses intimal hyperplasia after expanded polytetrafluoroethylene grafting in rabbits fed a high cholesterol diet.

The effect of purified eicosapentanoic acid on intimal fibrous hyperplasia in expanded polytetrafluoroethylene grafts was examined in 18 rabbits undergoing infrarenal aorta reconstruction. Six rabbits received commercial rabbit chow (control group), six a regular diet supplemented with 1% cholesterol (cholesterol group), and six the cholesterol diet with 91.1% pure eicosapentanoic acid 500 mg/day (eicosapentanoic acid group). Grafts were harvested 3 months after surgery for histologic examination. The platelet count and serum beta-thromboglobulin and platelet factor 4 concentrations were not significantly different between groups. Serum arachidonic acid level in the cholesterol group was significantly higher than in the control group, and serum eicosapentanoic acid levels in the eicosapentanoic acid group were significantly higher than in the remaining two groups. Intergroup differences in serum 6-keto-prostaglandin F1 alpha and thromboxane B2 concentrations were not significant. Intimal thickness at midgraft was 5.2 +/- 6.2 microns in the control group, 67.6 +/- 46.9 microns in the cholesterol group, and 19.2 +/- 18.4 microns in the eicosapntanoic acid group. intimal thickness in the cholesterol group was greater than in either the control or licosapentanoic acid group (p less than 0.01 and p less than 0.05, respectively). These data suggest that eicosapentanoic acid reduces intimal fibrous proliferation in expanded polytetrafluoroethylene grafting as a result of hypercholesterolemia and that this effect is independent of the platelet count, activated platelet factors, and the prostacyclin/thromboxane A2 ratio.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

[The fate of patients with intermittent claudication--comparison of surgical and non-surgical treatment].

The purpose of this study was to determine the operative indication for patients with intermittent claudication because of arteriosclerosis obliterans, and to compare the late result of the surgical treatment group (130 cases, 175 limbs) with that of the non-surgical treatment group (27 cases, 31 limbs). There were 3 operative deaths and 21 late deaths in the surgical group, and 11 late deaths in the non-surgical group. The number one cause of death was heart failure, including ischemic heart disease, in both groups. The 5-year cumulative patency rate was 92.5% in the aorto-iliac, 70.6% in the femoro-distal and 82.0% in the aorto-femoro-distal arterial reconstructions. Long term symptom free rates of the surgical group and the non-surgical group, except fatal cases, were 87.2% and 25.0% in the aorto-iliac, 57.7% and 25.0% in the femoro-distal, 86.7% and 0% in the aorto-femoro-distal arterial regions, respectively. Late result of intermittent claudication in the surgical group was better than that in the non-surgical group. We conclude that intermittent claudication should be considered to be the indication for surgery, except for the cases with high risk diseases or malignant diseases.

Female↗
PubMed1984

[Clinical evaluation of a femoral compression method for ischemic legs by transcutaneous oxygen tension measurement].

Transcutaneous oxygen tension (TcPo2) of the lower extremities was investigated in 20 patients of peripheral arterial occlusive disease. TcPo2 was monitored from bilateral calf and dorsum of the foot. Femoral compression method meant that the tourniquet was set at femoral region and the tourniquet was inflated to a suprasystolic pressure for 4 minutes, after cuff was deflated, TcPo2 returned to the initial level. T(min) was the time it took until initial TcPo2 level. T1/2(min) was the time it took until 50 percent of the initial level. The following results were obtained. T1/2 showed significant relation to Ankle Pressure Index. T1/2 of dorsum of foot showed blood flow of distal side of calf region and T1/2 of calf showed blood flow of femoral region. T1/2 was significant difference between ASO and TAO, among different sites of peripheral vascular occlusion. T1/2 measurement was a much more useful indicator of limb flow after operation than TcPo2 measurement.

Adult↗
PubMedDate not supplied

Spared flow tract within the mural thrombus of an aortic aneurysm: its pathogenesis and clinical importance.

The purpose of this case report is to determine the unique pathogenesis of a "spared flow tract" through a thick mural thrombus of an aortic aneurysm mimicking the penetrating or dissecting tract of an impending or acute rupture of an abdominal aortic aneurysm (AAA) and to discuss its clinical importance. Three blood flow tracts (i.e., spared flow tracts) penetrating to aortic major branches (inferior mesenteric arteries in two and left renal artery in one) through thick mural thrombi of three aortic aneurysms were found on thin section spiral CT scans. Histopathological examination revealed that the tracts were formed by thrombi and partially covered with endothelial cells. In conclusion, spared flow tracts may be pathways continuing to the aortic major branches through thick mural thrombi of aortic aneurysms and are spared from thrombogenesis because of relatively high blood flows. Their pathogenesis is definitely different from penetrating or dissecting tracts within mural thrombi of ruptured AAAs. Spared flow tracts should not be misinterpreted as penetrating or dissecting tracts of impending or acute rupture.

Acute Disease↗
PubMedDate not supplied

Complications of endovascular repair for thoracic and abdominal aortic aneurysm: an imaging spectrum.

Endovascular stent-graft implantation is an alternative to conventional open surgery for the treatment of aortic aneurysm. Forty-nine consecutive patients with aortic aneurysm (thoracic, n = 17; infrarenal, n = 32) were treated with endovascular stent-graft implantation. Complications occurred in 25 patients (two patients had two complications): endoleak (n = 13), graft thrombosis (n = 5), graft kinking (n = 2), pseudoaneurysm caused by graft infection (n = 1), graft occlusion (n = 1), shower embolism (n = 1), perforation of mural thrombus by means of inadvertent penetration of delivery system (n = 1), colon necrosis (n = 1), aortic dissection (n = 1), and hematoma at the arteriotomy site (n = 1). Imaging findings were analyzed for spiral computed tomography, plain abdominal radiography, transesophageal echocardiography, and digital subtraction angiography. Since some of these complications are fatal, radiologists need to instantly and accurately recognize them. Awareness and understanding of possible complications should help ensure a safe, successful procedure.

Aged↗
PubMedDate not supplied

Laparoscopic surgery in infants with intra-abdominal cysts: two case reports.

OBJECTIVES: We report two cases of infants found to have congenital omental cystic lesion with torsion and ovarian cyst treated by laparoscopy-assisted surgery (LAS). METHODS: A laparoscope was inserted by an open method. The intra-abdominal pressure was maintained at 8 mm Hg. We diagnosed the cystic lesions with torsion. At aspirator was used to aspirate the cystic content and remove the cyst. RESULTS: No intra- or postoperative complications were encountered. Oral intake was commenced on postoperative day 2 in both patients. The cosmetic results following LAS were excellent. CONCLUSIONS: We conclude that LAS is suitable for the management of omental cystic lesions with torsion and ovarian cyst in nursing infants. An aspirator is useful in preventing spillage of cystic contents in patients with intra-abdominal cystic lesion.

Cysts↗