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Biomedical subjects

N Montani

Publications and source records attributed to N Montani.

At least 19 recordsLinked to original sources
PubMed2006

Vasculitis and gastrointestinal involvement.

The incidence of gastrointestinal involvement is relatively observed in patients with vasculitis processes. Vasculitis can be primary (necrotising or hypersensitivity) or secondary to another primary disease. Gastrointestinal involvement is present in up to 50% of the various forms of systemic vasculitis. Primary or secondary vasculitic process, according to the classification in necrotizing and hypersensitivity vasculitis, are described in this paper. A review of the literature on the the subject is also presented.

Gastrointestinal Diseases↗
PubMed2001

Treatment of Raynaud's phenomenon with intravenous prostaglandin E1alpha-cyclodextrin improves endothelial cell injury in systemic sclerosis.

OBJECTIVE: To evaluate the efficacy and safety of prostaglandin (PG) E1alpha-cyclodextrin for Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc) and its effect on variables of immune activation and endothelial injury in SSc such as tumor necrosis factor-alpha (TNF-alpha), soluble interleukin 2 receptor (sIL-2R), circulating intercellular adhesion molecule-1 (cICAM-1), von Willebrand factor (vWF), and tissue-type plasminogen activator (t-PA). METHODS: We studied 36 women with SSc, 24 of them given three 60 microg intravenous PGE1alpha-cyclodextrin infusions on 5 consecutive days at 6 week intervals during the winter. RP symptoms and healing of digital lesions were evaluated. Twenty age matched healthy women were the controls. TNF-alpha, sIL-2R, cICAM-1, vWF, and t-PA were measured after the first and last infusion of PGEE1alpha-cyclodextrin and correlated with clinical features. RESULTS: RP symptoms improved in 87% of the patients. The benefit of each 5 day cycle lasted 4 or more weeks in 75%. PGE1alpha-cyclodextrin reduced the daily frequency of RP symptoms by 20% (p < 0.05), 41% (p < 0.005), and 53% (p < 0.0005) from baseline after the 1st, 2nd, and 3rd infusions, respectively. The severity of the attacks was reduced to a limited degree. In 12 of the 14 patients with digital lesions, these healed completely. Ten patients had mild side effects during treatment (headache, increased intestinal motility, flushing). TNF-alpha, sIL-2R, cICAM-1, vWF, and t-PA plasma concentrations were significantly higher in patients with SSc than controls (p < 0.05, p < 0.001). TNF-alpha, sIL-2R, and cICAM-1 were higher in diffuse SSc and patients with lung involvement. The plasma levels of cICAM-1 and t-PA were significantly reduced after the 1st infusion of PGE1alpha-cyclodextrin (both p < 0.005) and further reduced after the last (p < 0.0005 and p < 0.005). CONCLUSION: PGE1alpha-cyclodextrin reduces RP symptoms and plasma levels of the markers of endothelial injury in SSc, suggesting that an improvement of endothelial dysfunction contributes to its prolonged therapeutic effect.

Adult↗
PubMed2000

Clotting alterations in primary systemic amyloidosis.

BACKGROUND AND OBJECTIVE: The bleeding manifestations frequently observed in patients with immunoglobulin light chain amyloidosis (AL) have been attributed to different pathogenetic factors: amyloid deposits in several organs and systems leading to failures of these latter, the affinity of amyloid for some clotting factors, and the presence of plasma components interfering with fibrin formation could all induce alterations of clotting tests. This investigation was aimed at defining the prevalence of clotting abnormalities and their clinical manifestations in patients with AL. DESIGN AND METHODS: Thirty-six consecutive patients with biopsy proven amyloidosis and documented monoclonal gammapathy were enrolled within one year. The following clotting tests were considered in the study: activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), reptilase time (RT), Russell's viper venom time (RVTT), fibrinogen, factor X and alpha-2 antiplasmin. RESULTS: Hemorrhagic manifestations were mild to moderate in nine patients, but severe and untractable in one. The most frequent clotting anomaly was defective fibrinogen conversion to fibrin, as demonstrated by prolongation of both TT (85% of cases) and RT (90% of cases). Low levels of factor X activity were observed in about 1 out of 4 samples, while fibrinogen and alpha2 antiplasmin levels were distributed over a wide range of values. PT was prolonged in 8 and aPTT in 25 patients. The search for lupus anticoagulant was negative in samples showing a prolongation of aPTT and/or RVVT. INTERPRETATION AND CONCLUSIONS: The prolongation of TT and RT is not dependent on either the presence of a heparin-like substance in the plasma or on fibrinogen levels; furthermore, the prolongation of RVVT is not related to factor X level. The hypothesized presence in the plasma of an inhibitor of fibrin formation could also affect factor X activation by Russell viper venom. The prolongation of TT and RT represents a peculiar feature of amyloidosis. The variability in the behavior of the other clotting times and hemostatic factors studied is mirrored in the heterogeneity of the clinical features observed in this disease.

Adult↗
PubMed1999

Abnormalities in thrombin-antithrombin pathway in AL amyloidosis.

Various pathogenic factors have been proposed to explain the abnormal hemostasis observed in AL amyloidosis. Since imbalance between clotting factors and inhibitors could play a pathogenic role in both hemorrhagic and thrombotic manifestations, we investigated the thrombin-antithrombin pathway in 35 patients with AL amyloidosis. Ten patients suffered from bleeding while 3 patients experienced deep venous thrombosis. Thrombin time was prolonged in 29 subjects, the mean values of antithrombin III activity (ATIII Act) were significantly lower than those of antithrombin III antigen (ATIII Ag) with loss of relationship between these two different techniques of ATIII detection, normally observed in healthy controls. In 19 patients increased levels of thrombin-antithrombin (TAT) complexes were present. Crossed immunoelectrophoresis of ATIII, performed in presence of heparin, evidenced ATIII forms with reduced binding capacity to heparin and TAT complexes of various electrophoretic mobilities. In conclusion, the impairment of the thrombin-antithrombin pathway, in association with the low ATIII biological activity, might play a pathogenic role in the hypercoagulable state reported in AL amyloidosis, despite the higher frequency of bleeding manifestations.

Adult↗
PubMed1998

Expression of dipeptidylaminopeptidase IV/CD26 in peripheral blood lymphocytes of hemophilic subjects.

CD26 antigen, a 110 kDa membrane glycoprotein with exopeptidase activity (DAP IV), is an activation marker of T lymphocytes preferentially expressed on CD4+ memory cells and involved in T cell proliferation and IL-2 production after antigenic stimulation. We employed cytochemical and immunocytochemical techniques to study DAP IV/CD26 expression in circulating lymphocytes from 40 hemophilic patients, chronically treated with coagulation factors, in order to verify the possible involvement of this molecule in the immunological alterations of hemophilia. In all the hemophiliacs DAP IV activity was significantly lower than in the controls, independently of the quantity of blood transfused and previous exposure to viruses. This reduction may be responsible for the impaired proliferative response of lymphocytes to antigens and mitogens, notoriously observed in hemophilia. Whereas in the group of HIV- patients CD26 expression was similar to that of normal controls, in the 8 HIV+ hemophilic patients both percentages of positive lymphocytes and intensity of staining were significantly lower. In only 4 of the 8 cases was this deficit associated with CD4+ cell depletion. The significant selective loss of CD26 expression observed in HIV+ patients is probably an early event after HIV infection and seems to occur even before CD4 cell depletion. In conclusion, evaluation of DAP IV/CD26 might be a useful option for monitoring the immunological alterations of all hemophilic patients, HIV positive or not, chronically treated with coagulation factors.

Adolescent↗
PubMed1992

Platelet function after in vivo and in vitro treatment with thrombolytic agents.

Whereas in vitro studies showed that plasmin may induce both inhibition and activation of platelets, in vivo and ex vivo investigations suggested that thrombolytic agents are responsible for platelet stimulation. To gain further information on this topic, ex vivo platelet function was studied in 24 subjects with acute myocardial infarction treated with streptokinase or recombinant tissue-type plasminogen activator (rt-PA). Ten patients with acute myocardial infarction who did not receive thrombolytic treatment were also investigated. The data shows that at the end of thrombolytic infusion, the maximal extent of platelet aggregation and adenosine triphosphate release was reduced in treated patients compared with that in untreated ones. In subjects treated with streptokinase, the defect in platelet aggregation derived from both cellular and plasmatic defects. Plasmatic beta-thromboglobulin concentration was significantly reduced after streptokinase, but unchanged after rt-PA. Three days after thrombolytic treatment, platelet aggregation of patients receiving streptokinase or rt-PA was not significantly different from that of untreated subjects. A similar defect in platelet function was obtained in vitro, incubating normal platelet-rich plasma with pharmacologic concentrations of streptokinase. Again, platelet function defect derived from both cellular and plasmatic damages. It cannot be excluded that platelet activation occurs in patients with acute myocardial infarction during the very early phases of thrombolytic treatment. However, it is suggested that a transient defect in platelet function follows both streptokinase and rt-PA infusion.

Adenosine Triphosphate↗
PubMed1989

Study of three patients with monoclonal gammopathies and 'lupus-like' anticoagulants.

In three patients with monoclonal gammopathies: a case of multiple myeloma, a case of monoclonal gammopathy of uncertain significance (MGUS) and a case of monoclonal gammopathy associated with lymphocytic lymphoma, we found the presence of a circulating lupus-like anticoagulant. Coagulative studies showed that the paraproteins: an IgG3k, an IgG1k and an IgMlambda, were responsible for the anticoagulant activity by interacting with the thromboplastin phospholipids. Using isoelectrofocusing we demonstrated that the three monoclonal immunoglobulins had a strong basic charge which may have contributed to determining their interaction with the acidic thromboplastin phospholipids. The binding of various phospholipids to the monoclonal proteins was assessed by the fluorescence quenching method which showed heterogeneous specificity. In order to establish whether the electrical charge is also relevant in cases with polyclonal lupus anticoagulant, the polyclonal immunoglobulins were fractionated according to their charge. The strongest inhibitor activity was found in the most basic immunoglobulins. Monoclonal lupus-like anticoagulants represent useful tools for investigating the heterogeneous world of polyclonal lupus-like anticoagulants.

Aged↗
PubMed1988

Haemostatic variables, serum lipid abnormalities and vascular complications in diabetes mellitus: a 5 year follow-up study.

The relationship among blood lipids, haemostatic and fibrinolytic parameters have been evaluated, during a follow-up study, in 27 non-insulin dependent (type II) diabetic patients. Upon recruitment, and in periodical controls, we observed that plasma triglycerides and VLDL levels correlated inversely, and HDL directly, with the fibrinolytic activity of plasma and euglobulin precipitate. Furthermore triglycerides and VLDL correlated directly with Factor VIII antigen (vWFAg). After 5 years in the study, 12 patients (44%) had macroangiopathic complications, and 9 of these subjects showed persistently high levels of triglycerides (above 2.36 mmol/l). These haemostatic and lipid components, however, do not influence the progression of diabetic retinopathy and nephropathy. The alterations of lipid, haemostatic and fibrinolytic parameters and their possible relationships seem to play an important role in the occurrence of diabetic macroangiopathy.

Aged↗
PubMedDate not supplied

Purpura fulminans as clinical manifestation of atypical SLE with antiphospholipid antibodies: a case report.

Purpura Fulminans and DIC were the main clinical manifestations of the antiphospholipid syndrome observed in a 62-year-old man. The patient was well until 44 years of age when he began to suffer from recurrent thrombophlebitis, without other symptoms suggestive of immune disease. At the time of hospital admission the pt. appeared acutely ill, showing high fever, severe anemia, massive urinary blood loss, multiple purpuric patches evolving to hemorrhagic bullae and gangrene rapidly spreading over about 30% of the total body area. No signs of neurological involvement or of visceral thrombotic occlusions were present. Clotting tests were consistent with a diagnosis of DIC, further confirmed by skin biopsy showing the presence of thrombi in dermal arterioles. The autoantibody research was positive as follows: Waaler-Rose 1:40, Anti-DNA 1:80; ANF 1:640, aCA IgG 100 GPL. LA was diagnosed according to standard criteria: prolonged KCT and RVVT not corrected by a mixture of normal plasma and abnormal TTI. Plasma exchange in association with heparin and prednisone was effective in arresting the progression of the skin lesion; nevertheless the patient died ten days after hospital admission for sepsi and acute renal failure.

Autoantibodies↗
PubMedDate not supplied

Clotting abnormalities in children during maintenance chemotherapy for acute lymphoblastic leukemia.

BACKGROUND: Many of the drugs used in the treatment of acute lymphoblastic leukemia in children may induce modifications in different organs and functions. Following the observation of a recurrent, mild delay in the prothrombin time in ALL children during maintenance chemotherapy, we explored the main parameters of the clotting function. METHODS: 17 children with acute lymphoblastic leukemia were studied during maintenance chemotherapy for clotting function screening evaluation; 15 healthy children, matched for age and sex, were used as controls. RESULTS: A uniform pattern of slight prolongation of the prothrombin time with significantly reduced levels of factors VII, IX, and a trend toward reduced activity of factor X was observed in the absence of any demonstrable anticoagulant factor. CONCLUSIONS: Antileukemic maintenance chemotherapy is associated with a subclinical modification of the clotting parameters that is not responsible for hemorrhagic diathesis. Long-term administration of anti-metabolites (6-mercaptopurine and methotrexate) could be responsible for this reversible impairment.

Adolescent↗