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Biomedical subjects

A Cavallaro

Publications and source records attributed to A Cavallaro.

At least 73 records · Page 4Linked to original sources
PubMed1998

Iliac-to-isolated hepatic artery bypass in the treatment of intestinal angina: two cases.

Two cases in which a severe form of intestinal angina was cured by revascularization of an isolated hepatic artery were studied. The collateral pathways to the hepatic artery may serve, in a retrograde fashion, to assure an acceptable blood supply to the splanchnic organs, even when the disease of the 3 main vessels is so extensive that the commonly used techniques of revascularization cannot be applied.

Abdominal Pain↗
PubMed1998

Suppression of smooth muscle cell proliferation after experimental PTFE arterial grafting: a role for polyclonal anti-basic fibroblast growth factor (bFGF) antibody.

OBJECTIVES: To determine the role of polyclonal anti-basic Fibroblast Growth Factor (bFGF) antibody in inhibiting the proliferation of smooth muscle cells after experimental polytetrafluorethilene (PTFE) arterial grafting. MATERIALS: In 14 male inbred Lewis rats (weight 250 mg) a 1 cm long segment of PTFE was interposed at the level of abdominal aorta. Animals were randomised to receive polyclonal anti-bFGF antibody (group A: n = seven animals) or aspecific immunoglobulin (group B: n = seven animals). Anti-bFGF antibody or aspecific immunoglublin were given intraperitoneally at the end of operation, and for the first 2 postoperative days. Animals were sacrificed 7 days after surgery, 24 h after intraperitoneal injection of BromodeoxyUridin (BrdU) to label proliferating smooth muscle cells. RESULTS: One animal in each group died in the immediate postoperative period due to anaesthetic problems. All grafts were patent at the time of sacrifice. BrdU labelling index was statistically higher in the control group B animals at the level of the anastomotic regions (proximal anastomosis: group B 7.9% vs. group A 4.1%. Distal anastomosis: group B 5.1% vs. group A 2.6% p = 0.009) and at the level of PTFE graft (group B 3.8% vs. group A 2.6% p = 0.002), while there was no statistical difference between the control thoracic aorta of the two groups. MAIN CONCLUSIONS: bFGF plays a major role in the proliferation of smooth muscle cells at the level of the anastomoses after arterial PTFE grafting. Agents able to block the action of bFGF may be useful in inhibiting the formation of myointimal hyperplasia.

Anastomosis, Surgical↗
PubMed1998

Oxidised LDL (OxLDL) induces production of platelet derived growth factor AA (PDGF AA) from aortic smooth muscle cells.

OBJECTIVES: Elevated concentrations of oxidised low density lipoproteins (OxLDL) are associated with accelerated atherogenesis. The aim of our study was to determine the effect of OxLDL on the proliferation rate and platelet derived growth factor (PDGF) AA production on aortic smooth muscle cells. High density lipoproteins (HDL), which are known to have a protective effect against atherosclerosis, were used as control. MATERIALS AND METHODS: Bovine aortic smooth muscle cells were grown in presence of increased concentrations of OxLDL and HDL and in presence of control medium culture (DMEM). Proliferation rate was assessed by 3H-thymidine uptake. PDGF AA production was determined by ELISA and Western Blot Analysis. RESULTS: OxLDL increased the proliferation rate of aortic smooth muscle cells as compared to DMEM and HDL (p < 0.001). The mitogenic activity of OxLDL on smooth muscle cells was reduced adding anti-PDGF AA antibodies (p < 0.001). PDGF AA production by aortic smooth muscle cells was increased after exposure to OxLDL as compared to DMEM (p < 0.001). HDL significantly reduced the production of PDGF AA by aortic smooth muscle cells (p < 0.001). CONCLUSIONS: Part of the atherogenic effect of OxLDL is mediated through the autocrine production of PDGF AA from aortic smooth muscle cells.

Animals↗
PubMed1998

Shear stress induces transforming growth factor-beta 1 release by arterial endothelial cells.

BACKGROUND: Myointimal hyperplasia is a common complication after vascular reconstruction. Increasing shear stress has been shown to reduce formation of myointimal hyperplasia. The aims of our study were (1) to analyze the correlation between shear stress and release of transforming growth factor (TGF)-beta 1 by endothelial cells and (2) to determine the effect of TGF-beta 1 on smooth muscle cell proliferation. METHODS: Bovine arterial endothelial cells were subjected to increasing shear stress in an in vitro serum-free system. The release of TGF-beta 1 by endothelial cells was assessed by enzyme-linked immunosorbent assay and Western blot analysis. The effect of TGF-beta 1 on the proliferation of the subconfluent monolayer of bovine smooth muscle cells was determined by tritiated thymidine uptake. RESULTS: Shear stress induced a significant increase of the release of TGF-beta 1 by endothelial cells (p < 0.001). This phenomenon was proportional to the level of shear stress. The amount of TGF-beta 1 released by endothelial cells subjected to shear stress had a significant inhibitory effect on growth rate and tritiated thymidine uptake of smooth muscle cells. CONCLUSIONS: On the basis of the results of our study, we conclude that increasing shear stress induces release of TGF-beta 1 by arterial endothelial cells in a concentration that has a clear inhibitory effect on smooth muscle cell proliferation. This phenomenon could explain the inhibitory effect of increasing shear stress on the formation of myointimal hyperplasia.

Animals↗
PubMed1998

Formation of myointimal hyperplasia and cytokine production in experimental vein grafts.

BACKGROUND: The purpose of this study was to determine the correlation between progression and regression of myointimal hyperplasia (MH) and cytokine production in experimental vein grafts. Although the autologous vein is the best suitable bypass conduit for reconstruction of peripheral arteries, at the end of the first year thrombosis in the coronary and lower extremity circulation ranges from 20% to 50%. Many of these failures are caused by MH. METHODS: In 76 inbred Lewis rats, a 1 cm long segment of inferior vena cava was inserted at the level of the abdominal aorta. The segments of inferior vena cava were obtained from syngeneic Lewis rats. In 56 animals the arterial vein graft was explanted 3 days (n = 10), 7 days (n = 10), 4 weeks (n = 26), and 12 weeks (n = 10) after operation. In 20 animals the vein graft was explanted 4 weeks after being in the arterial system and reimplanted as iliac venovenous bypass in syngeneic Lewis rats. These grafts were explanted 2 weeks (n = 10) and 8 weeks (n = 10) later. Grafts were analyzed by light and electron microscopy, morphometric study, and histochemical analysis and were put in an organ culture to assess cytokine production. RESULTS: We observed MH formation in arterial vein grafts and MH regression in reimplanted vein grafts (p < 0.001). MH formation was correlated with production of platelet-derived growth factor, basic fibroblast growth factor, interleukin-1, and tumor necrosis factor-alpha. MH regression was correlated with transforming growth factor-beta 1 production. CONCLUSIONS: On the basis of the results of our study, we conclude that MH formation in experimental vein grafts depends on production of platelet-derived growth factor, basic fibroblast growth factor, interleukin-1, and tumor necrosis factor-alpha, and MH regression depends on transforming growth factor-beta 1 production. Cytokine therapy may represent a valuable new treatment to prevent vein bypass failures caused by MH.

Animals↗
PubMed1998

The abdominal aortic fenestration procedure in acute thoraco-abdominal aortic dissection with aortic branch artery ischemia.

OBJECTIVE: Diagnostic work-up and treatment strategies have improved the prognosis of acute thoraco-abdominal aortic dissection. Little attention to aortic branch artery ischemia or even failed restoration following prosthetic repair of thoraco-abdominal dissection still merit a problem with high morbidity and mortality. SETTING: Department of Vascular Surgery, Technische Universität München, Germany. PURPOSE: Reflecting on visceral and neurological ischemic complications in acute thoraco-abdominal aortic dissection indications and limitations of the abdominal-aortic-fenestration procedure are discussed with a review on our own clinical experience and the results reported in the literature. CONCLUSIONS: The abdominal-aortic-fenestration procedure is accomplished with minimal deterioration of the critically ill patient. In new onset or relief of aortic branch ischemia, following initial prosthetic repair of either type A or B dissection aortic fenestration is found to be an effective and secure adjunctive procedure to restore the blood flow of compromised organs. Primary abdominal aortic fenestration is recommended instead of prosthetic repair in cases of acute type B dissection. It is the treatment of choice because of branch artery ischemia becoming the focal point of deterioration.

Acute Disease↗
PubMed1998

[High-porosity and normal-porosity prostheses. Differences in growth factor release].

BACKGROUND: The majority of mid- and long-term synthetic vascular graft failures are due to anastomotic neointimal fibrous hyperplasia. The major cause of this phenomenon is the absence of an endothelial lining within prosthetic grafts. We investigated the PDGF-BB and bFGF release by umbilical vein endothelial cell cultured on precoated standard porosity or high porosity expanded polytetrafluoroethylene (ePTFE) vascular grafts. METHODS: Endothelial cell harvested from umbilical veins were cultured into standard (30 microns internodal distance) or high porosity (60 microns internodal distance) cPTFE disks. ePTFE disks uncoated or precoated with collagen type I, fibronectin and Matrigel were used and endothelial cell cultured into plastic wells coated as ePTFE disks or uncoated plastic wells served as controls. Scanning electron microscopy study assessed endothelial cell coverage. The presence of PDGF-BB and bFGF in serum-free conditioned media from endothelial cells cultured into ePTFE grafts and endothelial cell cultured into wells was determined by the inhibition antibody-binding assay 48 hours after insertion. RESULTS: Endothelial cell coverage was similar in uncoated and coated ePTFE grafts and no differences were observed between standard or high porosity grafts. The release of PDGF-BB and bFGF was significantly higher either for standard porosity or high porosity ePTFE grafts as compared with endothelial cell cultured into plastic wells (p < 0.05 and p < 0.05, respectively). The release of PDGF-BB and bFGF was independent from the various substrates either for endothelial cell cultured into standard or high porosity ePTFE grafts or plastic wells. CONCLUSIONS: Our findings pointed out that in ePTFE grafts smooth muscle cellsc proliferated only under endothelial cell at the anastomoses, along seeded synthetic grafts or in areas of transmural ingrowth where smooth muscle cells followed endothelial cell migrating into the graft. This is probably due to an alteration of the interactions between the endothelial cell, the matrices and the synthetic prosthesis.

Analysis of Variance↗
PubMed1997

Functional and morphological evaluation of canine veins following preservation in different storage media.

Injuries of endothelial and smooth muscle cells of autologous vein due to preservation in standard storage media may be responsible for graft failure. The effects of vein preservation with University of Wisconsin solution (UWs) on endothelial and smooth muscle cell function and morphology were compared to the effects of preservation with autologous whole blood (AWB) and normal saline (NS), which are frequently used in cardiovascular surgery. Canine external jugular and common femoral vein segments were preserved in the different solutions at 4 degrees C for 45 min and 24 hr. Rings (4-5 mm in length) from control and preserved veins were evaluated by isometric tension studies at 37 degrees C and by scanning and transmission electron microscopy. Differences between groups were evaluated by Student's t test or Mann-Whitney U test and by analysis of the variance, and considered to be significant at P < 0.05. Sensitivities to norepinephrine (NE) showed that a 45-min vein storage in AWB (5.7 +/- 0.2 mumol/L) but not in NS (5.8 +/- 0.2 mumol/L) or UWs (6.5 +/- 0.2 mumol/L) had a deleterious effect on function of smooth muscle (P < 0.05) when compared to control veins (6.6 +/- 0.2 mumol/L). Maximum contractile responses and sensitivities to NE were significantly altered (P < 0.05) after 24-hr vein storage in AWB (0.09 +/- 0.02 g/mm2 and 5.4 +/- 0.07 mumol/L) and NS (0.12 +/- 0.03 g/mm2 and 5.6 +/- 0.08 mumol/L) but not in UWs (0.36 +/- 0.06 g/mm2 and 6.4 +/- 0.07 mumol/L). With both storage times, acetylcholine-induced endothelium-dependent maximum relaxations and sensitivities were significantly reduced (P < 0.05) in veins stored in AWB and NS, but not in UWs, compared with controls. Similarly, transmission electron microscopy revealed marked neutrophil migration beneath the intimal surface of vessels and extensive separation and desquamation of endothelial cells with exposure of subendothelial structures in veins stored in AWB and NS. The results suggest that UWs is a suitable storage medium when compared to AWB and NS.

Animals↗
PubMed1997

Descending thoracic aorta-to-femoral artery bypass grafts.

BACKGROUND: Descending thoracic aorta-to-femoral artery (DTAFA) bypass graft is an alternative procedure to revascularize lower limbs. METHODS: Between 1976 and 1996, 41 patients underwent DTAFA bypass grafts. Operative indications consisted of previous abdominal graft thrombosis (22 cases, group 1), abdominal operations (8, group 2), initial vascular operation in the presence of difficult aortas (6, group 3), and infection of aortic grafts (5, group 4). RESULTS: Perioperative mortality was 5%. Cumulative 10-year primary patency, limb salvage, and survival rates were 64%, 79%, and 55%, respectively. Breaking down the result on the basis of the four groups, DTAFA bypass grafts performed for infection of previous aortic grafts had a significantly lower primary patency rate (25% at 24 months; P < 0.004) with dismal limb salvage (31% at 24 months; P < 0.001) and survival rates (0% at 24 months; P < 0.005). CONCLUSIONS: DTAFA bypass grafts can be safely and durably used in patients who had thrombosis of previous abdominal grafts or had a difficult abdomen or as the initial vascular operation in the presence of difficult aortas. Conversely, dismal results are obtained in the treatment of aortic graft infection.

Aged↗
PubMed1997

Aortoiliofemoral bypass graft in young adults: long-term results in a series of sixty-eight patients.

BACKGROUND: The aim of this study was to investigate surgical indications and the long-term outcomes of aoroiliofemoral reconstructions in adults younger than 45 years. METHODS: Between 1973 and 1990, 1256 patients underwent infrarenal abdominal aortic reconstruction for aortoiliofemoral occlusive disease. Sixty-eight (5.4%) patients (group 1) were less than 45 years old and form the basis of the analysis. They were retrospectively compared with two additional groups of patients 45 years and older selected from the entire series. Patients in group 2 (n = 100) were randomly chosen to determine differences in risk factors, associated diseases, operative indications, preoperative findings, and outcomes. Patients in group 3 (n = 70) were matched with those in group 1 for gender, risk factors, associated diseases, preoperative findings, and operative indications to assess the importance of age in determining the short- and long-term outcomes of aortoiliofemoral reconstructions. RESULTS: Postoperative mortality rates (1.5%, 4%, and 4.3% for groups 1, 2, and 3, respectively) and major complication rates (4.4%, 7%, and 7.1% for groups 1, 2, and 3, respectively) were comparable among the three groups. Ten-year secondary patency rates were 84.6%, 70.6%, and 80.3%, for groups 1, 2, and 3, respectively (p = not significant). Ten-year limb salvage rates were 86.9%, 78.2%, and 80.6%, for groups 1, 2, and 3, respectively (p = not significant). During follow-up a significantly higher percentage of myocardial infarction was recorded in group 1 as compared with group 2 (p < 0.03) and group 3 (p < 0.04). The 10-year survival rate for group 1 was significantly lower than that of group 2 (29.0% versus 46.9%; p < 0.005). CONCLUSIONS: Aortoliofemoral reconstruction in patients younger than 45 years is a safe procedure with low operative risks and good long-term results in patency and limb salvage rates. However, life expectancy is poor because of the high incidence of deaths related to coronary artery disease.

Adult↗
PubMed1997

Short-term preservation of autogenous vein grafts: effectiveness of University of Wisconsin solution.

BACKGROUND: Suboptimal preservation of autologous veins in storage solutions causes endothelial cell damage that can contribute to graft failure. The purpose of this study was to compare the effects of short-term storage of veins in autologous whole blood (AWB), 0.9% normal saline solution (NS), and University of Wisconsin solution (UWs) on vein structure and function after grafting. METHODS: Autogenous jugular and femoral veins were atraumatically harvested from mongrel dogs. One vein segment was immediately implanted to serve as a control, and the other segments were stored for 45 minutes in AWB, NS, or UWs. The veins were implanted as reversed interposition graft in the carotid or femoral arteries. After 6 weeks light and scanning electron microscopy and isometric tension studies were performed on explanted vein grafts. RESULTS: Morphologic studies revealed an intact endothelium that stained positively for factor VIII. Intimal thickness was similar between controls (48 +/- 12 microns) and veins stored in UWs (53 +/- 8 microns) (p = not significant), but it was significantly increased in veins stored in AWB (151 +/- 29 microns) and NS (149 +/- 18 microns) (p < 0.05). Sensitivity and maximum contraction to norepinephrine were not altered in veins preserved in UWs (6.0 +/- 0.1 mumol/L and 0.19 +/- 0.02 gm/mm2) but were significantly reduced (p < 0.05) in those stored in AWB (7.2 +/- 0.1 mumol/L and 0.08 +/- 0.02 gm/mm2) and NS (7.0 +/- 0.3 mumol/L and 0.09 +/- 0.02 gm/mm2) compared with controls (5.9 +/- 0.2 mumol/L and 0.20 +/- 0.02 gm/mm2). The sensitivity and maximum relaxation to acetylcholine and sodium nitroprusside of veins preserved in AWB, NS, and UWs were similar to controls (p = not significant). CONCLUSIONS: Vein storage in UWs preserves smooth muscle cell function compared with veins stored in NS or AWB. Therefore UWs is a more suitable medium for short-term preservation of veins in cardiovascular operation.

Adenosine↗
PubMed1997

Role of reoperation in recurrence of adrenal cortical carcinoma: results from 188 cases collected in the Italian National Registry for Adrenal Cortical Carcinoma.

BACKGROUND: Recurrence of adrenal cortical carcinoma (ACC) after radical surgery is a common finding. Although successful reoperations have been reported with encouraging results, most published experiences are anecdotal and based on few cases. We report the results of surgical treatment for recurrent ACC in a multiinstitutional series. METHODS: One hundred eighty-eight cases of ACC were collected in a national registry. A complete follow-up was obtained in 179 cases. At initial diagnosis 92 patients had local disease (stage I or II). One hundred seventy patients underwent surgical treatment, considered radical in 140; in this group, recurrent disease was observed in 52 cases (37%) after a mean disease-free interval of 21.7 months. RESULTS: Adjuvant chemotherapy was ineffective in ameliorating the prognosis. The mean survival in 20 patients who underwent reoperation was significantly higher (15.85 +/- 14.9 months) than in nonreoperated cases (3.2 +/- 2.9 months). Five-year actuarial survival in reoperated patients is significantly better than in nonreoperated patients (49.7% versus 8.3%, respectively). CONCLUSIONS: Although the prognosis of this tumor is still poor, surgery is the only effective therapy; reoperation allows survival comparable to that observed in patients without recurrent disease. An aggressive strategy for recurrent ACC is advisable until prospective studies demonstrate a real effectiveness for chemotherapy.

Adolescent↗
PubMed1997

Popliteal artery entrapment syndrome: the role of early diagnosis and treatment.

BACKGROUND: The purpose of this study was to evaluate whether certain factors could influence arterial impairment at presentation for treatment of popliteal artery entrapment syndrome (PAES) and whether its early diagnosis could optimize long-term results. METHODS: Between 1979 and 1995, 30 patients were treated for PAES at our institution. Patients were characterized by age, risk factors, associated diseases, preoperative symptoms, affected side, dominant limb, duration of symptoms, musculotendinous structure causing the compression, arteriographic findings, arterial status at presentation, type of operation, postoperative complications, and long-term follow-up. RESULTS: Twenty-nine (65%) limbs underwent musculotendinous section (MTS), 15 (33%) limbs underwent vascular reconstruction, and 1 (2%) was surgically explored. Patients submitted to MTS were younger (mean, 31 +/- 3 years) than patients who underwent vascular reconstruction (mean, 41 +/- 4 years; p < 0.05). MTS limbs had a greater number of minor symptoms compared with those that underwent vascular reconstruction (62% versus 20%; p < 0.02). Arteriogram showed that MTS limbs had a greater number of normal findings at rest when compared with limbs that underwent conventional reconstruction (85% versus 0%; p < 0.001). No specific factors influenced the arterial status at presentation. During follow-up, treadmill examination revealed that MTS limbs had a better response (96%) than limbs that had undergone vascular procedures (67%; p < 0.02). MTS limbs had a better long-term patency rate (mean, 87 +/- 7 months) compared with limbs that were submitted to vascular reconstruction (mean, 107 +/- 8 months) (95% versus 65%; p < 0.02). CONCLUSIONS: Because PAES is a progressive disease that can create serious vascular obstructive disease and no specific factors seem to influence the degree of vascular impairment, the detection and treatment of PAES at an early stage permit better long-term results.

Adolescent↗
PubMed1997

Carotid endarterectomy in young adults: is it a worthwhile procedure?

PURPOSE: The aim of the study was to investigate surgical indication and long-term outcome of carotid endarterectomy (CE) in young adults. METHODS: Between 1973 and 1990, 1693 patients underwent CE. Forty-nine patients (group T) 35 to 45 years of age who had carotid artery stenosis greater than 70%, formed the basis for the analysis. They were compared with two additional groups of patients older than 45 years of age selected from the entire series. Group 2 was randomly chosen to determine differences in risk factors, associated diseases, operative indications, preoperative findings, and outcome. Group 3 was matched with patients in group 1 for sex, risk factors, associated diseases, preoperative findings, and operative indications to assess the importance of age in determining the short- and long-term outcome of CE. RESULTS: Postoperative mortality, cerebrovascular accidents, and cardiac complications in patients of group 1 (2%, 2%, and 2%, respectively) were similar to those of the other groups (p = NS). During the follow-up (76.7 +/- 3.6 months; range, 1 to 120 months) the incidence of strokes and transient ischemic attacks in group 1 was lower than in group 2 (p < 0.05) but similar to group 3 (p = NS). Ten-year disease-free intervals were 75.7%, 58.7%, and 77.6%, respectively, for groups 1, 2, and 3. Mortality rate unrelated to cerebrovascular disease was similar between group 1 and group 3 (p = NS) but was higher in group 1 than in group 2 (p < 0.02). Ten-year survival rates were 46.1%, 71.7%, and 55.5%, respectively, for groups 1, 2, and 3. CONCLUSIONS: CE in patients younger than 45 years of age is a safe procedure with low operative risks and good disease-free intervals. However, life expectancy is poor because of the high incidence of deaths resulting from complications of atherosclerosis.

Adult↗
PubMed1997

Growth factors and myointimal hyperplasia in experimental aortic allografts.

OBJECTIVES: To analyse the role of growth factors (platelet derived growth factor, PDGF; basic fibroblast growth factor, bFGF; interleukin 1, IL-1) in the genesis of myointimal hyperplasia in arterial allografts. MATERIALS: Two groups of experiments were performed: isografts and allografts. The isograft group consisted of 15 inbred Lewis rats in which a 1 cm long segment of aorta was inserted as an abdominal aortic interposition graft. The aortic segments were obtained from syngenic Lewis rats. The allograft group consisted of 15 inbred Lewis rats, in which a 1 cm long segment of aorta was interposed at the abdominal aorta level. The aortic segments were obtained from allogenic Brown-Norway rats. CHIEF OUTCOME MEASURES: The animals were killed 4 weeks after surgery and were analysed by morphometric analysis (n = 3 for each group). In addition, production of PDGF, bFGF and IL-1 by aortic segments (n = 12 for each group) in organ culture was assessed. MAIN RESULTS: Allografts had more myointimal hyperplasia, than isografts (p < 0.05). PDGF and bFGF production, generally considered to be the cause of myointimal hyperplasia, was not increased in allografts. IL-1 production was higher in allografts (p < 0.001). MAIN CONCLUSIONS: Myointimal hyperplasia in aortic allografts is dependent on growth factors produced by the graft itself. These growth factors are different from PDGF and bFGF that generally have been implicated in the genesis of naturally occurring myointimal hyperplasia and atherosclerosis. IL-1 may have a principal role in the genesis of myointimal hyperplasia in arterial allografts.

3T3 Cells↗
PubMed1997

Intramural esophageal hematoma after cardioversion.

Intramural esophageal hematoma is a very rare condition. We report a case of a 40-year-old male, presenting with retrosternal pain and dysphagia. On the day before admission tarry stool and minimal vomiting of old blood was noticed. Diagnostic procedures showed an intramural esophageal hematoma, which had developed 2 weeks and 3 days after cardioversion and anticoagulation therapy. Etiology, differential diagnosis, the diagnostic approach and a brief review of the literature are discussed.

Adult↗