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Biomedical subjects

A Cavallaro

Publications and source records attributed to A Cavallaro.

At least 19 recordsLinked to original sources
PubMed1992

Modulation of arterial smooth muscle cell growth by haemodynamic forces.

To define the correlation between flow dynamics and the proliferation of arterial smooth muscle cells (SMCs), bovine arterial SMC were subjected to increasing laminar flow shear stress in an in vitro system. Smooth muscle cells were seeded in a fibronectin-coated polystyrene cylinder at 5 x 10(5) cells/tube. The experimental groups were subjected to increasing shear stress (3, 6, 9 dyn cm-2) for a 24-h period. The control group was subjected to similar incubation conditions without flow. Shear stress reduced significantly (p less than 0.01) the 24-h incorporation of tritiated thymidine and cell proliferation. This effect was proportional to the level of shear stress and was still evident 24 h after flow cessation. Flow cytometry demonstrated a lower percentage of SMCs in S-phase with increasing shear stress. Extrapolation of these findings to the clinical setting might explain how unphysiological shear stress can predispose to the abnormal proliferation rate of SMCs and early plaque formation.

Animals↗
PubMed1992

Comparative results of carotid-subclavian bypass and axillo-axillary bypass in patients with symptomatic subclavian disease.

The results of 26 carotid-subclavian bypass (CSB) and 17 axillo-axillary bypass (AAB) procedures, performed to treat symptomatic lesions of the proximal subclavian artery, were reviewed. Nine graft failures (seven CSB and two AAB) occurred (mean follow-up: CSB = 60.5 +/- 41 months; AAB = 67.8 +/- 48 months). All CSB graft thromboses were observed in patients with an associated ipsilateral carotid lesion, surgically treated or not (p less than 0.05). Cumulative 5- and 10-year patency rates were 78.3 and 62.9% for the CSB group and 87.9% for the AAB group (N.S.). In patients with an associated ipsilateral carotid lesion, 5- and 10-year patency rates were 66.0% and 40.8% for the CSB group and 100% for the AAB group (p less than 0.05). Both the surgical procedures were safe and effective with excellent results in terms of operative mortality, major morbidity and long-term patency. CSB is the procedure of choice for the treatment of proximal subclavian artery disease for its physiological characteristics and for graft shortness. However AAB must be considered a suitable alternative and preferred when a concomitant ipsilateral carotid lesion is present. Recurrence of carotid stenosis or carotid lesion progression may cause the carotid-subclavian failure.

Aged↗
PubMed1992

Growth factor release by smooth muscle cells is dependent on haemodynamic factors.

Abnormal proliferation of smooth muscle cells (SMCs) is a key event in the development of the atherosclerotic plaque. The early atherosclerotic plaque localises preferentially in areas of flow separation. The basic mechanisms which correlate haemodynamic forces and atherosclerotic plaque formation are not known. Bovine arterial SMCs were subjected to increasing levels of shear stress for 24 h in an in vitro system. The control group was subjected to similar incubation conditions without flow. SMCs subjected to shear stress released a higher quantity of mitogens, including a platelet derived growth factor (PDGF)-like substance. This mitogenic activity was partially reduced (30%, p < 0.01) by an excess of monospecific anti-PDGF antibody. The release of mitogens was proportional to the level of shear stress and was still evident 24 h after flow cessation. In conclusion, shear stress influences the release of mitogens; this might represent a mechanism which links haemodynamic forces and atherosclerotic plaque formation.

Animals↗
PubMed1992

[Inflammatory aneurysm of the abdominal aorta: anatomo-clinical study on 16 cases and pathogenetic hypothesis].

BACKGROUND: Inflammatory aneurysms of the abdominal aorta constitute an anatomoclinical entity characterised by prominent thickening and fibrosis of the aneurysmal wall, extending to the adjoining structures. Etiology, pathogenesis and relation with atherosclerosis still remain controversial. METHODS: Sixteen consecutive patients undergoing surgery for inflammatory aneurysm of the abdominal aorta between March 1987 and December 1990 were studied (Group I); as a control, a series of 16 consecutive patients operated on in the same period for atherosclerotic aneurysm of the abdominal aorta was selected (Group II). As far as clinical history and symptoms are concerned, the comparison between the two groups revealed significant differences only for hydronephrosis (exclusively present in Group I, p < 0.05) and abdominal pain (more frequent in Group I, p < 0.01). The microscopic study of the aneurysmal wall was performed by scoring its histological features (atherosclerotic lesions, medial and adventitial fibrosis, inflammatory infiltrates and lymphatic stasis) from 1+ to 3+. RESULTS: As regards the microscopical features, atherosclerotic lesions were present in all the examined cases, whereas periadventitial fibrosis appeared in all the aneurysms of Group I and in none of Group II; the comparison between the two groups revealed further significant differences for extensive intimal calcification (exclusively present in Group II, p < 0.05), fibrous replacement of the tunica media (more thorough in Group I, p < 0.02), and the extent of inflammatory infiltrates (more prominent in Group I, p < 0.05). CONCLUSIONS: From the scarcity of pathognomonic features in both case-history and clinical presentation, the constant coexistence of prominent atherosclerotic lesions, and the progressive trend of the pathologic features, inflammatory aneurysms may be inferred to be a variant of atherosclerotic ones, characterised by a particular prominence of inflammation and fibrosis. The frequent occurrence of dilation of both periaortic lymphatic vessels and lymph node sinuses, even in "incipient" aneurysms, supports the hypothesis that it may be the lymphatic stasis which determines periaortic fibrosis. Finally, atherosclerotic components passing into periaortic fibrosis and eliciting granulomatous reaction were observed in two Group I cases featuring prominent "inflammatory" symptoms; such a finding favours the hypothesis that an immune reaction against some components of the atherosclerotic plaque may lead to the pronounced inflammatory response that is peculiar of inflammatory aneurysms.

Aged↗
PubMed1991

Surgical treatment of popliteal artery entrapment syndrome: a ten-year experience.

Popliteal artery entrapment syndrome is increasingly described in the world literature as a cause of lower limb arterial impairment. It is caused by the anomalous interrelationship between the popliteal artery and its surrounding muscular and/or tendineous structures. The first case surgically treated was reported in 1959 and since then more than 300 cases have been reported including our personal experience (31 cases in 23 patients). We have treated surgically 19 males and four females with symptoms which were moderate (cramping after intensive physical training, paraesthesia, etc.) in 14 limbs, intermittent claudication in 16 and necrosis (first toe) in one. Preoperative arteriography showed arterial occlusion in eight limbs, stenosis in eight and aneurysms in two. In 11 limbs stenosis or occlusion was only shown after active plantar hyperextension and in two arteriography was not done because surgical indications were established on the basis of a venogram positive for popliteal vein entrapment syndrome. Ten different anatomical variants were seen and the medial head of gastrocnemius muscle was involved in 74.2%. Surgical treatment consisted of division of the aberrant musculotendinous tissue in 18 cases (in two of these balloon angioplasty was also used). In 12 cases a vascular reconstruction was also required, while one case was explored without a specific procedure being warranted. Optimal results were obtained when the syndrome was treated at an early stage by simple division of musculotendinous tissue (94.4% long-term patency rate, mean follow-up 46.0 months, min 2, max 120 months). When arterial grafting was required the long-term patency rate was only 58.3% (mean follow-up 43.5 months, min 1, max 100 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Diagnosis of popliteal artery entrapment syndrome: the role of duplex scanning.

The authors present a new diagnostic procedure to quickly and noninvasively diagnose the popliteal artery entrapment syndrome. A large personal experience on the surgical treatment of such a disease (29 cases in 22 patients) allowed us to focus on the optimal diagnostic procedure useful to detect this problem at an early stage. The technique is based on continuous-wave Doppler and duplex scanning studies done both in the resting state and during active contraction of the calf muscles. If compression of the popliteal artery occurs with contraction of the calf muscles, it will be detected by a decrease in flow. This finding will also direct the radiologist to obtain films when the maneuver is repeated. This makes it unlikely that the diagnosis will be missed. Since July 1988 a total of 1212 patients were evaluated with continuous-wave Doppler for suspected chronic ischemia. From this group 41 patients were selected to be studied again with the combined continuous-wave Doppler and duplex scanning method for possible popliteal artery entrapment syndrome. Two cases were discovered and verified by dynamic angiography guided by continuous-wave Doppler and treated surgically.

Adult↗
PubMed1991

Leiomyosarcoma of the inferior vena cava: analysis and search of world literature on 141 patients and report of three new cases.

Leiomyosarcoma of the inferior vena cava is a rare and potentially curable tumor. Uncertainty about the results of treatment derives from lack of a large series in the same center and of a long-term follow-up of the published cases. A review of the world literature from 1871 to 1989 allowed us to collect information on 141 patients with inferior vena cava leiomyosarcoma to which our three cases have to be added. The tumor arose from the lower segment of the inferior vena cava (infrarenal portion) in 49 patients, from the middle segment (from the renal veins to the hepatic veins) in 59, and from the upper segment (from the hepatic veins to the right atrium) in 34 patients. Complete clinical, pathologic, and therapeutic data and up-to-date follow-up have been obtained through personal correspondence with several authors. All data have been examined with both univariate and multivariate analyses as predictive factors for outcome. Variables, associated with an increased risk of death from disease, included the involvement of inferior vena cava upper segment and a high-grade tumor. Patients who underwent a radical resection of the tumor (82 patients, 56.9%) had a significantly better survival (27.9% and 14.2%, 5- and 10-year survival rates, respectively). Of these patients, those with tumor of the inferior vena cava middle segment fared better than those with lower segment tumor (5- and 10-year survival rates were 48.3% and 34.4%, respectively, for middle segment tumor and 9.3% and 0.0% for lower segment tumor). Variables associated with a good outcome and longer survival were the presence of abdominal pain and the absence of a palpable abdominal mass. Despite the high rate of recurrence (52.4% of patients undergoing radical operation; median time, 25 months), radical resection of inferior vena cava leiomyosarcoma is the only chance for a long-term cure. An earlier and more accurate preoperative diagnosis, by means of modern diagnostic techniques (echography, CT scanning, magnetic resonance imaging) will allow a higher rate of radical resection to be performed with an increase in patient survival.

Adult↗
PubMed1991

Prostaglandin E2-induced inhibition of the in vitro immune response by SRBC-stimulated human lymphocytes.

Exogenous PGE2 strongly inhibits the response of human lymphocyte cultures to SRBC. This effect is mediated through a T cell inhibition since non-T cells are not significantly affected. Indomethacin, which inhibits in this system lymphocyte endogenous PGE2 synthesis increases the in vitro immune response. The effect of indomethacin is overcame by exogenous PGE2. These data may be relevant for explaining the immunomodulatory role of PGE2 following antigen challenge.

Animals↗
PubMed1991

Plasmapheresis in the therapy of hyperthyroidism associated with leukopenia.

Surgery, the treatment of choice for hyperthyroidism due to nodular goiter, requires an euthyroid state, which is generally achieved with thionamides. Leukopenia is the most serious toxic effect of thionamides, and it causes controindication. We report a 50-year old woman with severe hyperthyroidism and leukopenia, in whom an euthyroid state before thyroidectomy was obtained with the use of therapeutic plasmapheresis. This procedure was carried out immediately before surgery using an intermittent flow separator; three sessions removed a total of 6,300 cc of plasma. Plasmapheresis caused a rapid reduction of both total and free thyroid hormone levels. Thyroidectomy was performed without any complications. Plasmapheresis can be considered a valid and safe method to prepare hyperthyroid patients for thyroidectomy when other therapies are ineffective or counterindicated.

Antithyroid Agents↗
PubMed1991

Factors influencing the rupture of abdominal aortic aneurysms.

The gross findings of 49,144 autopsies performed at two major hospitals in Rome were reviewed. There were 297 patients who were found to have atherosclerotic abdominal aortic aneurysm (AAA). The aneurysm was intact in 220 (74 per cent) and ruptured in 77 (26 per cent). The occurrence of aneurysm rupture was correlated to 17 variables by univariate and multivariate statistical analysis. Covariates found to be independently predictive of the rupture of AAA were the size of the aneurysm (p less than 0.001), arterial hypertension (p less than 0.001) and the presence of bronchiectasis (p less than 0.025.). Over-all, bronchiectasis was more common among patients with AAA than in the age-adjusted and sex-adjusted control population. The simultaneous presence of bronchiectasis and AAA suggests the presence of some inherited or acquired tendency to have ectasia of the connective tissue, aneurysm formation and rupture development.

Adult↗
PubMed1990

Antitumor effect of the new rhodium (II) complex: Rh2 (form)2 (O2 CCF3)2 (H2O)2 (form = N,N'-di-p-tolyl formamidinate).

The new rhodium(II) complex Rh2(Form) (O2CCF3)2(H2O)2 (Form = N,N'-di-p-tolyl formamidinate) was evaluated for its toxicity on the rat and for its efficacy against two tumors of this animal: the Yoshida ascites sarcoma and the T8 sarcoma of Guérin. The rhodium(II) formamidinate shows very low toxicity: in fact 150 mg/kg (the highest quantity of drug soluble in 4 ml of dimenthyl sulfoxide) is not toxic for rats. We were unable to establish the lethal dose or the highest nontoxic dose since larger mounts of complex require a dose of dimethyl sulfoxide (DMSO) that is itself toxic and the compound is insoluble in other solvents such as water or Tween. Doses of rhodium(II) formamidinate, varying from 3 to 30 mg/kg, were administered once by i.p., i.v., i.m. and intratumor (i.t.) route from 1 to 7 days after i.p. injection of 10(6) Yoshida ascites sarcoma cells and subcutaneous (s.c.) implantation of approximately 300 mg (corresponding to 2-3 x 10(7) living tumor cells) of T8 sarcoma of Guérin. The compound is active when administered i.p. 24 hours after Yoshida ascites sarcoma at the smallest dose tested (3 mg/Kg), increasing the average life span of 62.3% and allowing the survival of 50% of the rats. It is also active when administered i.p. at the highest dose tested (30 mg/Kg) 7 days after tumor cell challenge, increasing the average life span in 43.8% and allowing survival in 20% of the rats; it is not active after i.v. or i.m administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Percutaneous transluminal angioplasty versus surgery for subclavian artery occlusive disease.

Twenty-one patients who underwent percutaneous transluminal angioplasty (PTA) for proximal stenosis of the subclavian artery were compared with 15 patients who underwent carotid subclavian reconstruction. This represents the first attempt to directly compare the two procedures. All patients had routine Doppler examination during follow-up. Mean follow-up was 30 +/- 24 months after PTA and 40 +/- 25 months after surgery. The incidences of procedural complications were similar (PTA one complication, surgery two complications). Although better early results were achieved in patients who underwent PTA (actuarial patency: PTA 91 percent, surgery 87 percent), after dilatation, we observed a continuous deterioration of the hemodynamic status of the artery, which led to a high rate of late restenosis (actuarial patency: PTA 54 percent, surgery 87 percent). There were no significant changes postoperatively. The specific role of each procedure is analyzed in view of the new acknowledgment of the clinical importance of proximal subclavian artery disease.

Angioplasty, Balloon↗
PubMed1989

Effect of prostaglandin E2 on pokeweed mitogen-activated human lymphocyte cultures.

It is shown that a short incubation of peripheral human lymphocytes with PGE2 is able to reduce the B cell differentiation induced by PWM. The target of PGE2 action appears to belong to T lymphocytes, since the treatment of non-T cells is uneffective in reducing the immune response. Both OKT4+ and OKT8+ subsets are sensitive to PGE2. Data concerning the role of endogenous as well as exogenous PGE2 either on unfractionated or fractionated OKT4+, OKT8+ and non-T lymphocytes are also discussed. The PGE2 inhibition on immunoglobulin synthesis in PWM-stimulated cultures seems to be mediated by a complex effect on both the T cell subsets.

Antibody-Producing Cells↗
PubMed1989

[Evaluation of prognostic factors in surgery of gastric cancer].

The prognostic role of some clinical and pathologic variables in patients with carcinoma of the stomach was evaluated. While for some of these (invasion of the gastric wall, nodal status) the prognostic value is widely accepted, for the others (age, sex, size and site of tumors, histologic type, surgical procedure) the prognostic significance has not been fully defined. Using univariate analysis, the best predictors of survival after curative resection were nodal status, histologic type and serosal involvement. As related to the last three, using a multivariate analysis, the serosal involvement was the most important prognostic variable.

Adult↗
PubMed1989

Thrombolysis of graft occlusion using high dose urokinase. An alternative to surgical treatment?

Two cases of acute leg ischemia from unilateral occlusion of an aorto-bifemoral graft, treated with high-dose urokinase intra-arterial infusion, are reported. This therapy allowed identification of the cause of thrombosis, recanalization of the graft and planning of reoperation. Indications for intra-arterial thrombolytic therapy and advantages of urokinase vs streptokinase are discussed.

Aged↗
PubMed1989

Magnetic resonance imaging of abdominal aortic grafts.

The widespread use of abdominal aortic grafting procedures and increasing awareness of related complications suggests the need for a reliable and non-invasive diagnostic technique which will allow early detection of both occlusive and non-occlusive complications. Ultrasound is generally used with satisfactory results, but has several limitations, whereas MRI has shown great promise in the study of cardiovascular disease, being non-invasive, multiplanar and multiparametric. The present research aims to evaluate MRI in the follow-up of abdominal aortic grafts, attempting to define its significance as a screening procedure in non-selected patients. MRI is reliable in ascertaining the normality of the graft as well as the complications, these being partial or total thrombosis, pseudoaneurysms and perigraft collections. The data obtained are highly satisfactory and are almost always superior to those achieved with ultrasound and CT.

Aorta, Abdominal↗
PubMed1989

Popliteal aneurysms.

A 15 year experience with 50 popliteal aneurysms in 36 patients is reviewed. Forty-seven popliteal aneurysms were atherosclerotic while three were related to entrapment of the popliteal artery. Fourteen asymptomatic popliteal aneurysms were observed preoperatively during a mean period of 26 months. Ischemic complications developed in five of these. At admission, 16 limbs were asymptomatic (group 1) while the other 34 limbs presented with ischemic symptoms (group 2). No operation was performed upon three limbs, and another two were surgically explored and amputated. No operative deaths resulted from 45 vascular reconstructions. Results from follow-up study of one to 176 months (a mean of 57 months) revealed a late patency rate of 62 per cent. The late patency rate of autologous saphenous vein (ASV) was 100 per cent; polytetrafluoroethylene (PTFE) and Dacron (polyester fiber) grafts had a patency rate of 74 and 34 per cent, respectively (ASV versus PTFE, p = N.S.; ASV versus Dacron, p less than 0.002). The rate of late salvage of limbs was 88 per cent. The bypass grafts of group 1 and those performed upon limbs with good runoff fared significantly better than others (p less than 0.05 and p less than 0.001). The risk of natural complications of popliteal aneurysms and the good results from surgical treatment suggested that a revascularization procedure in the asymptomatic stage is always recommended. The use of PTFE grafts for repair of popliteal aneurysms is justified when the ASV is not available. The use of Dacron grafts is no longer indicated.

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