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Biomedical subjects

A Cavallaro

Publications and source records attributed to A Cavallaro.

At least 91 records · Page 5Linked to original sources

Management of abdominal aortic prosthetic graft infection requiring emergent treatment.

The purpose of this study was to investigate mortality and morbidity rates and long-term outcome of patients who underwent emergency treatment of abdominal aortic prosthetic graft infection. Between January 1984 and December 1993, 18 men aged fifty-nine +/- sixteen years were operated on as an emergency for an acute life-threatening complication of aortic prosthetic graft infection. The grafts had been implanted for abdominal aortic aneurysm in 9 patients and aortoiliac occlusive disease in 9, from one to one hundred seventy months previously. Five (28%) patients presented with a hemorrhagic shock due to a fistula between the vascular reconstruction and the small bowel (4 patients) or the right ureter (1 patient) and 13 (72%) had generalized sepsis. The grafts were always radically explanted. Extraanatomic revascularization procedures included 6 axillopopliteal and 12 axillofemoral bypass grafts. Operative mortality was 39% (7 patients), and 3 (9%) limbs were amputated within thirty days. Two (11%) patients died after seven and twelve months, respectively, of septic complications, and 1 (5%) patient died after six months from an unrelated cause. Eight (73%) patients are still alive at a mean follow-up of fifty +/- thirty-four months, but in 3 the extraanatomic bypass was removed for infection and 5 major amputations were performed. Two-year survival and limb salvage rates were 44% and 50%, respectively. Aortic prosthetic graft infections that require emergent treatment continue to demonstrate high early and late mortality and limb loss rates despite aggressive intervention and limb salvage procedures. Newer methods of managing these complications should continue to be investigated.

Amputation, Surgical↗

An ectopic parathyroid adenoma revealed by L-thyroxine side effect on bone. Case report.

Hyperparathyroidism due to an ectopic parathyroid adenoma commonly is revealed by parathyroid hormone (PTH) high serum level and its clinical effects on bone loss. We report a case in which exogenous L-thyroxine side effect on bone in the treatment of thyroid solitary nodule disease produced bone loss in a patient with subclinical hyperparathyroidism due to an ectopic parathyroid adenoma. Our case report suggests the importance of monitoring both clinical symptomatology and calcium and phosphorous serum levels as routine lab investigation in all patients who receive L-thyroxine treatment.

Adenoma↗

[Differentiated cancer of the thyroid: prognostic aspects].

Ten-year span survival from differentiated thyroid cancer has been reported as ranging around 90%. Prognostic factors to be regarded as positive elements are young age, lack of lymph node and hematogenous metastasis, size < 4 cm, and low grading. The Authors investigate those features that have seemed to affect morbidity rate and long-term survival from differentiated thyroid cancer (T, N, M, age, sex, ploidy, benign thyroid lesions, etc.). The Authors deem the appreciation of such prognostic factors as being conducive to a better selection of treatments for any patient in terms of survival span and quality of life.

Adenocarcinoma, Follicular↗

[A case of retroperitoneal fibrosis with spontaneous regression].

Retroperitoneal fibrosis has an unknown pathogenesis. Medical treatment should be preferred to surgery. However, surgical treatment is required when an ureteral involvement is present. A case of retroperitoneal fibrosis with spontaneous regression is reported. Current knowledge on pathogenesis, diagnosis and preferred treatment is outlined.

Aged↗

Fresh vein allograft survival in dogs after cyclosporine treatment.

Synthetic grafts are widely used for peripheral arterial reconstructions when autologous veins are not available, but their results have not been satisfactory. Venous allograft may be used as an alternative to synthetic prostheses. The aim of the study was to explore the immunosuppressive efficacy of Cyclosporine A (CyA) as a means of preventing venous allograft failures and rejection. We utilized 56 mongrel dogs. Immunological incompatibility was checked with the skin graft method. Donor inferior vena cava was transplanted into the infrarenal abdominal aorta of recipient animals. One group (group 1, 10 dogs) served as a control and three groups received CyA treatment regimens. Group 2 (10 dogs) received postoperative oral CyA treatment for 30 days. Group 3 (12 dogs) received a vein graft pretreated with a CyA solution without postoperative immunosuppressive therapy. Group 4 (9 dogs) received a vein graft pretreated with a CyA solution and postoperative CyA treatment for 30 days. Allografts were examined at 30 days for patency, aneurysmal dilatation, gross structural changes, inflammatory response, and lymphocytic infiltration. Sex chromatine assessment determined the origin (donor or recipient) of the endothelial cells. The allografts from groups 1 and 3 showed significant aneurysmal dilatation and perivenous inflammation when compared to dogs treated with oral CyA therapy (P < 0.0002). Moreover allografts treated with CyA therapy had a better-developed venous neointima (P < 0.009) with less fibrin (P < 0.02) and thinner medial (P < 0.0009) with less fibrin (P < 0.02), and thinner medial (P < 0.0009) and adventitial layers (P < 0.02). No significant differences were observed in neointimal thickness among the four groups. Lymphocytic infiltration was greater in the group of animals who did not receive oral CyA therapy (P < 0.0004). Barr bodies status showed significant differences between oral CyA treated groups and nontreated groups (P < 0.0003). Oral CyA therapy reduced aneurysmal dilatation and immunological response, promoted the development of a neoendothelium, and preserved the structure of the venous layers. Graft pretreatment with CyA flushing did not have a significant immunosuppressive effect.

Animals↗

Femoral artery aneurysms: long-term follow-up and results of surgical treatment.

Aneurysmal dilatation of the femoral artery is a rare condition of uncertain aetiology. Between January 1972 and December 1992, 31 atherosclerotic femoral aneurysms in 22 patients were seen. There were 21 men and 1 woman; mean(s.d.) age was 70.1(10.4) years. Thirteen (42%) femoral aneurysms (group 1) were isolated aneurysms, two being bilateral. Eighteen (58%) were associated with a non-contiguous abdominal aortic aneurysm, four being unilateral and seven bilateral femoral aneurysms (group 2). The mean(s.d.) size of these aneurysms was 4.7(1.5) and 3.5(0.7)cm in groups 1 and 2 respectively (P< 0.01). Of the limbs in group 1,12 were treated by an interposition bypass. A ruptured profunda femoris artery aneurysm was ligated in one limb as an emergency operation. All patients in group 2 underwent an aortobifemoral graft. There was one operative death. Three early thromboses were observed; two autogenous saphenous vein interposition grafts and one limb of an aortobifemoral. One late thrombosis occurred in an expanded polytetrafluoroethylene graft in group 1. The five-year patency rate was 80% for group 1 and 88.9% for group 2 (P=n.s.). The overall 10-year limb salvage rate was 100%. These findings suggest that isolated femoral aneurysms are larger and more frequently symptomatic than femoral aneurysms associated with an abdominal aortic aneurysm. The association between femoral aneurysm and abdominal aortic aneurysm was found to be higher in patients with bilateral femoral aneurysms compared with those with unilateral lesions (P< 0.05). In the treatment of isolated femoral aneurysms better early results were obtained with expanded polytetrafluoroethylene interposition grafts.

Aged↗

Growth factor production by arterial and vein grafts: relevance to coronary artery bypass grafting.

BACKGROUND: Occlusion caused by myointimal hyperplasia, atherosclerosis, or both is the main reason for late failure of saphenous vein coronary artery bypass grafts. On the other hand, internal mammary artery grafts are usually spared from atherosclerosis. Evidence exists that platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) are involved in the genesis of myointimal hyperplasia and atherosclerosis. The aim of this study was to assess the production of PDGF and bFGF by arterial and vein grafts. METHODS: In 20 inbred Lewis rats alpha 1 cm long segment of arterial graft was interposed at the level of the abdominal aorta. In a control group of 20 Lewis rats alpha 1 cm long segment of vein graft was implanted at the level of the abdominal aorta. Animals were killed 4 weeks after operation, and the grafts were studied in serum-free organ culture to assess the production of PDGF and bFGF. RESULTS. Arterial grafts produced a smaller quantity of PDGF and bFGF than vein grafts (p < 0.01) Higher mitogenic activity was present in the conditioned media from vein grafts than in the conditioned media from arterial grafts (p < 0.001). A large amount of myointimal hyperplasia was present in all vein grafts. CONCLUSIONS: This phenomenon could explain the rarity of atherosclerotic changes in internal mammary coronary bypass grafts.

3T3 Cells↗

Growth factor production after polytetrafluoroethylene and vein arterial grafting: an experimental study.

PURPOSE: Occlusion caused by myointimal hyperplasia appears to be the main reason of late failure of polytetrafluoroethylene (PTFE) arterial bypass grafts. Evidence exists that growth factors are involved in the genesis of myointimal hyperplasia. The aim of this study was to assess the release of platelet-derived growth factor (PDGF) and basic fibroblastic growth factor (bFGF) by PTFE arterial grafts. METHODS: In 15 inbred Lewis rats a 1 cm long segment of PTFE was interposed at the level of the abdominal aorta. In a control of another 15 Lewis rats in a vein graft was implanted at the level of the abdominal aorta. Animals were killed four weeks after implantation and the tissue was studied in organ culture for release of PDGF AA, PDGF BB, and bFGF. RESULTS: PTFE grafts released a greater quantity of PDGF AA than did control vein grafts (28 +/- 4 ng/cm2/72 hr vs 7 +/- 2 ng/cm2/72 hr). Similarly, PTFE grafts released a greater quantity of bFGF than did arterial vein grafts (308 +/- 22 ng/cm(2)/72hr vs 204 +/- 20 ng/cm2/72 hr). CONCLUSIONS: We conclude that PTFE arterial grafts released a high quantity of growth factor, which could explain, in part, the occurrence of distal anastomotic myointimal hyperplasia.

Anastomosis, Surgical↗

Progression and regression of myointimal hyperplasia in experimental vein grafts depends on platelet-derived growth factor and basic fibroblastic growth factor production.

PURPOSE: The factors that lead to myointimal hyperplasia (MH) in arterial vein grafts (AVGs) are unknown. Platelet-derived growth factor (PDGF) and basic fibroblastic growth factor (bFGF) are two powerful mitogens for smooth muscle cells that have been implicated in the genesis of MH. The aim of this study was to analyze the correlation between progression and regression of MH and production of PDGF and bFGF in experimental vein grafts. MATERIALS: In 64 inbred Lewis rats, a 1-cm segment of inferior vena cava was inserted at the level of the abdominal aorta. The segments of inferior vena cava were obtained from syngenic rats. In 48 rats, the AVG was explanted 3 days (n = 8), 7 days (n = 8), 4 weeks (n = 24), and 12 weeks (n = 8) after surgery. In 16 rats the vein graft was explanted after being in the arterial system for 4 weeks and was reimplanted as a venous-venous bypass in syngenic Lewis rats. Reimplanted vein grafts (RVGs) were explanted 2 weeks (n = 8) and 8 weeks (n = 8) later. Grafts were analyzed by light and electron microscopy, morphometry, and histochemistry, and were put in organ culture to assess PDGF and bFGF production and mitogenic activity. RESULTS: We observed MH formation in AVGs and MH regression in RVGs (p < 0.001).PDGF and bFGF production correlated with the degree of MH (p < 0.01). Histochemistry showed PDGF and bFGF in the area of MH in AVG, which disappeared in RVG. Conditioned media from AVG had greater mitogenic activity than RVG or control veins. CONCLUSION: MH formation and regression in experimental vein grafts correlate with PDGF and bFGF production.

3T3 Cells↗

Duodenal obstruction following elective abdominal aortic aneurysm repair.

A case where duodenal obstruction complicated elective repair of abdominal aortic aneurysm is reported. A review of the literature shows that the incidence of this rare complication has probably been underestimated. Patients should be treated expectantly, regardless of the pathogenesis of the obstruction.

Aged↗

The degree of porosity influences the release of growth factors by healing polytetrafluoroethylene (PTFE) grafts.

OBJECTIVES: The aim of this study was to determine the influence of the degree of porosity on the release of growth factors (PDGF AA, PDGF BB, bFGF) by healing PTFE grafts. DESIGN AND SETTING: Laboratory animal study. MATERIALS: 1 cm long segments of non-reinforced PTFE grafts (30 microns fibril length, 2 mm internal diameter, 0.39 mm thick) were placed as an abdominal aortic interposition in Lewis rats. Fifteen grafts served as control (Group A; porous grafts); in eight rats (Group B; non porous grafts) the PTFE graft was completely wrapped by a non-porous plastic envelope. Animals were killed 4 weeks after surgery. OUTCOME MEASURES: The release of PDGF AA, PDGF BB and bFGF was assessed by Enzyme Linked Immunosorbent Assay (ELISA). RESULTS: The release of PDGF AA, PDGF BB and bFGF was statistically higher in porous grafts. The only histological difference between the two groups was that porous PTFE grafts were invaded by many tufts of capillaries from the surrounding tissue, whereas this phenomenon was absent in non porous PTFE grafts. CONCLUSIONS: The degree of porosity influences the release of growth factors by healing PTFE grafts. This fact may have implication in the endothelisation of PTFE grafts and in myointimal hyperplasia formation as well.

Animals↗

Incidence of transient ischemic attacks in the Belluno Province, Italy. First-year results of a community-based study.

OBJECTIVES: This study formed part of a larger prospective population-based survey on cerebrovascular diseases and aimed to provide reliable and comparable results on TIA incidence and on related risk factors, which could supply investigation objectives and support information for primary and secondary prevention. MATERIAL AND METHODS: We undertook a prospective population-based study in the province of Belluno, an area located in the North-East of Italy where 211,389 people live, utilizing all the possible case-collection sources available in the territory. RESULTS: In the first year of the study (June 1, 1992 to May 31, 1993) 271 patients with a diagnosis of transient ischemic attack were recruited. Among these, we recorded 171 cases of new TIAs. The crude annual incidence rate for new TIAs was 0.80 per 1000, 0.73 per 1000 for men and 0.87 per 1000 for women. After adjustment to the European population, the overall incidence rate decreased to 0.58 per 1000 inhabitants per year. The mean age of new TIA patients was 73.91 years and females were significantly older than males (p < 0.001). A CT scan disclosed an infarct in 21 new TIA patients. CONCLUSION: Our first-year results on new TIAs incidence did not differ from the findings reported in previous population-based studies performed throughout the world and support data as to risk factors for TIA.

Adult↗

Plasma endothelin-1 levels in patients with aldosterone-producing adenoma and pheochromocytoma.

The aim of the study was to evaluate possible changes of plasma endothelin-1 levels (ET-1) in patients with hypertension secondary to primary aldosteronism and pheochromocytoma. We enrolled in the study: 12 patients affected by aldosterone-producing adenoma (5 M and 7 W; mean age 42.1 +/- 17.2 years); 8 patients with pheochromocytoma (5 M, 3 W; mean age 36.2 +/- 17.1 years); 15 patients with essential hypertension (9 M, 6 W; mean age 48.5 +/- 10 years). We also enrolled a normal control group (8 M, 12 W; mean age 34.2 +/- 11 years). The mean plasma ET-1 concentrations in patients with pheochromocytoma were significantly higher (23.9 +/- 5.2 pg/ml) than those in normal subjects (7.3 +/- 1.9 pg/ml), in patients with primary aldosteronism (12.1 +/- 3.8 pg/ml) and in patients with essential hypertension (9.2 +/- 3 pg/ml); p < 0.001, respectively. The present investigation demonstrates that in human adrenal hypertension patients with pheochromocytoma have increased circulating ET-1 levels respect to patients with aldosterone-producing adenoma.

Adenoma↗

Hemodynamic forces modulate simultaneously the release of growth factors and the organisation of cytoskeleton of aortic smooth muscle-cells.

Recurrent stenosis because of myointimal hyperplasia or atherosclerosis after carotid endarterectomy occurs in 5-15% of the cases. The key event is the abnormal proliferation of arterial Smooth Muscle Cells (SMC). After endarterectomy SMC are directly exposed to the blood flowing under pressure. The aim of the present study was to determine the changes in morphology, cytoskeleton organisation, and release of growth factors by SMC exposed to laminar flow. Subconfluent SMC were exposed to a level of shear stress of 6 dyne/cm2 (100 ml/min) for 24 hours under conditions of steady laminar flow. The changes in morphology and cytoskeleton organisation were analysed by light and scanning electron microscopy, and by fluorescence microscopy. Growth factors release was assessed by ELISA. After exposure to laminar flow, SMC assumed a spindle-like shape; they lost many of their protrusions and there was a clear reorganisation of the cytoskeleton and simultaneously their released a higher quantity of PDGF and bFGF. In this study, we found simultaneous changes in cytoskeleton organisation and release of growth factors in SMC exposed to flow. Cytoskeleton reorganisation might be the mechanism through which SMC respond to changes in blood flow. These findings may help to explain the genesis of myointimal hyperplasia following carotid endarterectomy.

Cytoskeleton↗

University of Wisconsin solution effects on intimal proliferation in canine autogenous vein grafts.

This study was carried out to investigate if the University of Wisconsin solution (UWs) is suitable for long-term preservation of autogenous vein grafts (AVG) prior to transplantation, compared to autologous whole blood (AWB) and normal saline (NS). Autogenous jugular and femoral veins were harvested from adult mongrel dogs, using a "no-touch" technique. One segment of vein was immediately implanted to serve as a control, while other segments were stored for 24 hr at 4 degrees C in AWB, NS, or UWs. The control and the preserved veins were implanted as reversed interposition grafts in the common carotid or femoral artery positions. After 6 weeks, scanning electron microscopy revealed an intact endothelial cell monolayer in all vein grafts that was stained positively for factor VIII. The degree of intimal thickening, as assessed by light microscopy in the middle position of the grafts, was similar in controls (52.0 +/- 15.8 microns) and in veins stored in UWs (58.5 +/- 16.1 microns), but it was significantly increased (P < 0.05) in veins preserved in NS (198.9 +/- 19.5 microns) and in AWB (312.0 +/- 171.6 microns). Isometric tension studies revealed that maximum contraction and sensitivities (assessed by EC50) to norepinephrine were significantly reduced (P < 0.05) in AVG stored in AWB (0.05 +/- 0.02 g/mm2 and 5.5 +/- 2.8 microM), but not in UWs (0.16 +/- 0.03 g/mm2 0.92 +/- 0.34 microM) and NS (0.09 +/- 0.03 g/mm2 and 3.0 +/- 1.1 microM), compared with controls (0.17 +/- 0.03 g/mm2 and 0.99 +/- 0.38 microM). Acetylcholine (Ach)-induced maximum relaxations were similar in all of the veins.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗