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Biomedical subjects

F Rossi

Publications and source records attributed to F Rossi.

At least 505 records · Page 28Linked to original sources
PubMed1991

Anti-idiotypes against anti-neutrophil cytoplasmic antigen autoantibodies in normal human polyspecific IgG for therapeutic use and in the remission sera of patients with systemic vasculitis.

Anti-neutrophil cytoplasmic antigen (ANCA) activity was inhibited in 15 out of 21 sera from patients with acute systemic vasculitis following incubation with normal polyspecific IgG for therapeutic use (IVIg). ANCA antibodies reacted with IVIg through idiotypic-anti-idiotypic interactions, as shown in competitive binding assays using F(ab')2 fragments from IVIg and affinity chromatography of ANCA IgG on Sepharose-bound F(ab')2 fragments from IVIg. Co-incubation of sera from patients with acute systemic vasculitis with paired autologous remission stage sera also resulted in inhibition of ANCA activity in acute sera. Remission sera contain IgM and IgG capable of interacting with beta and or alpha idiotypes of ANCA IgG from acute sera. Anti-idiotypic IgM may account for the lack of expression of ANCA activity in whole serum from patients in remission from systemic vasculitis, which were found to contain high titres of ANCA IgG. These observations suggest that remission of systemic vasculitis is associated with the generation of anti-idiotypes against autoantibodies rather than the suppression of production of ANCA autoantibodies. IVIg may modulate the activity of systemic vasculitis in vivo.

Antibodies, Anti-Idiotypic↗
PubMed1991

Beneficial effect of human therapeutic intravenous immunoglobulins (IVIg) in mercuric-chloride-induced autoimmune disease of Brown-Norway rats.

Administration of HgCl2 to the susceptible Brown-Norway (BN) strain of rats induces an autoimmune disease characterized by polyclonal B cell activation, increased serum levels of IgE and the occurrence of anti-glomerular basement membrane antibody-mediated glomerulonephritis. We have observed that the simultaneous administration to BN rats of normal human polyspecific immunoglobulins for therapeutic use (IVIg) with HgCl2 significantly decreased the occurrence and severity of proteinuria, and reduced serum IgE levels in diseased animals. Hypergammaglobulinaemia was potentiated in animals receiving HgCl2 and IVIg, compared with animals receiving HgCl2 alone. In vitro experiments indicated that F(ab')2 fragments from IVIg inhibited the binding to laminin of pathogenic anti-laminin antibodies from diseased rats, as did antibodies from the resistant Lewis strain of rats but not antibodies from susceptible BN rats. These observations suggest that IVIg may interfere with the immune regulatory mechanisms involved in mercury-induced autoimmune disease in an analogous fashion to the ability of IVIg to suppress the expression of certain pathological autoimmune responses in humans.

Animals↗
PubMed1991

1-Acyl-, 3-acyl- and 1,3-diacyl-3-furfuryl-1-phenylthioureas with platelet antiaggregating and other activities.

The synthesis in excellent yields of 1-acyl-3-furfuryl-1-phenylthioureas 2 by reacting at t less than or equal to 10 degrees C 3-furfuryl-1-phenylthiourea 1, prepared in situ from furfurylamine and phenyl isothiocyanate, with aromatic or heterocyclic acyl chlorides in pyridine solution is described. 1-Acylthioureas 2 rearranged in high yields to 3-acylthioureas 3 by treatment with sodium hydroxide in heterogeneous phase. 1,3-Diacyl-3-furfuryl-1-phenylthioureas 4 were obtained in satisfactory yields by treatment of 1 with two moles of acyl chloride as in the case of 1-monoacylation. The thiourea 1 prepared in situ reacted with iodomethane in dimethylformamide solution and in the presence of sodium hydride to give in high yield the S-methyl derivative, namely the methyl ester of N-phenyl-1-furfurylaminethiocarboximidic acid. Some acylthioureas 2 and 4 showed a platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid. The 1,3-diacylthiourea 4 c exhibited an appreciable anticonvulsant activity in mice and some compounds 2 and 4 moderate competitive antiacetylcholine and H1-antihistamine effects in vitro.

Acetylcholine↗
PubMed1991

Economic evaluation of drug prescription monitoring systems in the extra-hospital environment.

Drugs expenditure accounts for a significant and rising share of public health expenditure (from 14% in 1980 it has now reached 17% approximately). Many efforts have been made to contain its expansion through tickets (co-payments), formularies, price policies, etc., but overall results have been unsatisfactory. The main cause for this failure may be found in the approach adopted, virtually excluding the evaluation of rational use of drugs. Economic evaluation of drug prescription, comparing cost per DDD, assessing both cost/effectiveness ratios and the monitoring system's efficiency, may contribute to a better control of drug expenditure.

Cost-Benefit Analysis↗
PubMed1991

[Acute instability of the shoulder in athletes. The role of magnetic resonance in therapy planning].

Magnetic resonance imaging (MRI) of the shoulder was performed to evaluate both the actual role of this technique in the study and staging of acute shoulder instability, and its potentials as diagnostic tool, with particular reference to treatment planning. Seventeen athletes with acute shoulder instability were examined. All MRI examinations, subsequent to plain radiographs, were performed within 48 hours from the traumatic event. After MRI examination, 14 patients underwent physiotherapy (2 cases were subsequently submitted to arthrotomy), and only 3 cases underwent surgical treatment in the acute phase (2 arthrotomies and 1 arthroscopy). These cases, submitted to MRI in the acute phase and subsequently to surgery, showed anterior glenoid labrum involvement with good evidence of associated skeletal lesions (Hill-Sachs lesions in 1); changes in the inferior glenohumeral ligament complex (2 cases) were also observed. In the other examined cases, MRI always provided accurate information on the glenoid labra and the anterior capsular mechanism. When the superior glenohumeral ligament was investigated (9 cases of 17), no alterations were observed. Acting as natural contrast, the presence of joint effusion allows good visualization, on T1-weighted sequences, of the structures involved by the traumatic events. Contrast resolution improvement could be obtained by employing gradient-echo T2 weighted sequences, which proved to be quite valuable for a correct depiction of the lesions involving the inferior glenohumeral ligament complex. In conclusion, MRI can be considered as a valuable diagnostic method for the early evaluation of the acute shoulder instability, since it provides information of the utmost importance for the subsequent therapeutical approach.

Adolescent↗
PubMed1991

omega-Dialkylaminoalkyl esters of 3-dialkylamino-4,7,7-trimethyl-N-phenylbicyclo[2.2.1] hept-2-ene-2-iminothiolic acids with local anesthetic activity.

A series of omega-dialkylaminoalkyl esters of 3-dialkylamino-4,7,7-trimethyl-N-phenylbicyclo[2.2.1]hept-2-ene-2- iminothiolic acids 3 was prepared by reaction of 4,7,7-trimethyl-3-(dimethylamino or 1-piperidinyl)-N-phenylbicyclo[2.2.1] hept-2-ene-2-thiocarboxamides with a number of omega-chloroalkyldialkylamines in the presence of sodium hydride in DMF or benzene solution. Some esters 3 showed an appreciable local anesthetic activity in mice.

Anesthetics, Local↗
PubMed1991

[Painful gleno-humeral joint instability in athletes. Radiographic findings].

Instability of the glenohumeral joint is a common cause of chronic shoulder pain and disability in athletes using repetitive arm movements in elevation and external rotation. A series of 29 athletes with persistent shoulder discomfort for transient subluxation was evaluated with plain radiography and tomography in right axillary projection. The purpose was to detect abnormalities in the osseous glenoid rim. Twenty-six patients (89.6% of all cases studied) had various degrees of skeletal damage, including 18 fractures (69.2%) of the anterior rim, 2 (7.6%) of the posterior rim, and 6 cases (23.07%) of local degenerative changes; 3 cases were negative for skeletal damages. The result of this study demonstrate conventional radiography to be useful in the diagnostic assessment of shoulder pain in athletes, where similar problems must be promptly detected and not ignored.

Humans↗
PubMed1991

Effects of cefonicid on platelet aggregation.

Beta-lactam antibiotics may interfere with platelet aggregation by inhibiting the binding of agonists of platelet aggregation, such as ADP and collagen, to specific receptor sites. The aim of this study was to evaluate in vitro the effects of cefonicid, a semi-synthetic cephalosporin, on platelet aggregation. Spontaneous platelet aggregation and platelet aggregation induced by ADP and collagen were assessed. Platelets from healthy subjects were incubated with cefonicid at final concentrations of 0.1 mg/ml, 1 mg/ml and 10 mg/ml (0.1 mg/ml is the concentration of cefonicid achieved in humans at therapeutic doses). When compared with saline, cefonicid at a concentration of 0.1 mg/ml had no effect on platelet aggregation, but at 1 mg/ml it inhibited ADP-induced aggregation and at 10 mg/ml it also inhibited aggregation induced by collagen. These findings suggest that therapeutic doses of cefonicid do not affect platelet aggregation.

Adenosine Diphosphate↗
PubMed1991

Recombinant human erythropoietin therapy in patients with rheumatoid arthritis with the anemia of chronic disease.

We treated 5 patients with rheumatoid arthritis (RA) with anemia of chronic disease with recombinant human erythropoietin (rHuEPO) for 11 weeks. An increase in hematocrit (Hct) greater than 5 was seen in 4 patients after 4 weeks of therapy. The 5th patient had a significant rise in Hct when the dosage of rHuEPO was increased to 150 units/kg from the 4th to 7th week. The subcutaneous administration of rHuEPO dose, reduced by one third with respect to initial dose, maintained an effective Hct value in all the 5 patients during the last 4 weeks of therapy. There was no change in disease activity. In one patient Hct normalization completely resolved symptoms of angina pectoris and permitted hip replacement surgery in another. No side effects occurred during rHuEPO therapy. We conclude that HuEPO is an effective, safe and well tolerated therapy for RA patients with severe anemia of chronic disease.

Aged↗
PubMed1991

Deficient fibrinolytic response in patients with Raynaud's phenomenon and its correction with defibrotide.

Twenty outpatients presenting with Raynaud's phenomenon secondary to clinical or preclinical inflammation of connective tissue were treated orally with defibrotide 400 mg three times daily or a matching placebo in a randomized double-blind study. The test product defibrotide (a polydeoxyribonucleic acid compound of animal origin with demonstrated profibrinolytic activity when administered parenterally) was administered orally for 3 weeks in order to explore its effects on the parameters of extrinsic fibrinolysis before and after venous stasis. The antigen of t-PA and its inhibitor PAI, free and total, and the biologic activity of PAI were assayed in basal conditions and after treatment. Although a marked increase of t-PA was seen with the active treatment, PAI activity was significantly reduced by defibrotide. Immunoreactive PAI was not significantly modified by treatment, even though it dropped considerably after venous stasis in the defibrotide group. Thus, the disturbance of endothelial function that seems to occur in vasculitis and in Raynaud's phenomenon secondary to inflammation of connective tissue (or so suspected to be) would constitute the basis of a disturbance of fibrinolysis, which oral defibrotide seems able to correct. Further studies are warranted to define the clinical effectiveness of this treatment in patients with Raynaud's phenomenon.

Adult↗
PubMed1990

Molecular basis of interferon-gamma and lipopolysaccharide enhancement of phagocyte respiratory burst capability. Studies on the gene expression of several NADPH oxidase components.

In this study, we analyzed the expression of genes encoding for components of the phagocyte superoxide anion-generating system in human phagocytes treated with interferon-gamma (IFN-gamma) or lipopolysaccharide (LPS). Human neutrophils express high levels of the 47-kDa cytosolic factor (p47-phox), which are down-regulated after treatment with IFN-gamma, but not with LPS. On the contrary, the steady-state levels of the heavy chain subunit of cytochrome b558 (gp91-phox) were increased by IFN-gamma and LPS in human monocyte-derived macrophages and neutrophils in a time- and dose-dependent fashion, whereas cytochrome b558 light chain subunit (p22-phox) mRNA was not influenced by either agent. Studies on post-transcriptional regulation at the level of mRNA stability indicate that, in neutrophils, IFN-gamma has no influence on gp91-phox and p47-phox mRNA half-lives. The content of the two cytochrome b558 subunits was quantified by enzyme-linked immunosorbent assay, which revealed that, in neutrophils, gp91-phox levels doubled after 4 h of treatment with IFN-gamma or LPS. Monocyte/macrophage maturation was associated with a gradual decrease in gp91-phox mRNA and protein levels, which were both restored by treatment with IFN-gamma for 24-48 h. These results suggest that induction of the gp91-phox gene and protein product by IFN-gamma or LPS is an important requirement in the mechanism of the enhancement of neutrophil and macrophage oxidative metabolism.

Cells, Cultured↗
PubMed1990

The Ch21 protein, developmentally regulated in chick embryo, belongs to the superfamily of lipophilic molecule carrier proteins.

Ch21, a developmentally regulated low molecular weight protein observed in chick embryo skeletal tissues, is expressed "in vitro" by differentiating chondrocytes at a late stage of development. Here we report the complete amino acid sequence of the protein. 86% of the total amino acid sequence was deduced by sequences of 17 high performance liquid chromatography-separated proteolytic fragments and 33 amino acid residues at the amino-terminal end of protein purified from spent culture medium of hypertrophic chondrocytes. Furthermore we isolated by molecular cloning the corresponding cDNA and determined its nucleotide sequence. By combining protein and nucleotide sequence data we determined the primary structure of the entire Ch21. It consists of 158 amino acids and has a molecular mass of 18.065 kDa. Computer-assisted analysis showed that the Ch21 belongs to the superfamily of low molecular weight proteins sharing a basic framework for binding and transport of small hydrophobic molecules.

Amino Acid Sequence↗
PubMed1990

Photosensitizing activity of water- and lipid-soluble phthalocyanines on Escherichia coli.

Escherichia coli, as most Gram-negative bacteria, is insensitive to the photosensitizing action of both lipid-soluble Zinc-phthalocyanine (Zn-Pc) and water-soluble Zinc-mono/disulfonated phthalocyanine (Zn-PcS). Photosensitivity can be induced by alteration of the outer membrane, as obtained by either induction of competence or treatment with Tris-EDTA. Both phthalocyanines largely bind at the level of the cytoplasmic membrane; however, Zn-PcS shows a superior photosensitizing activity as compared with Zn-Pc. Biochemical analyses performed on irradiated cells suggest that the cytoplasmic membrane is an important target of the photoprocess, while DNA is not involved.

Bacterial Outer Membrane Proteins↗
PubMed1990

The vitamin K-dependent carboxylation system in human osteosarcoma U2-OS cells. Antidotal effect of vitamin K1 and a novel mechanism for the action of warfarin.

An osteoblast-like human osteosarcoma cell line (U2-OS) has been shown to possess a vitamin K-dependent carboxylation system which is similar to the system in human HepG2 cells and in liver and lung from the rat. In an 'in vitro' system prepared from these cells, vitamin K1 was shown to overcome warfarin inhibition of gamma-carboxylation carried out by the vitamin K-dependent carboxylase. The data suggest that osteoblasts, the cells involved in synthesis of vitamin K-dependent proteins in bone, can use vitamin K1 as an antidote to warfarin poisoning if enough vitamin K1 can accumulate in the tissue. Five precursors of vitamin K-dependent proteins were identified in osteosarcoma and HepG2 cells respectively. In microsomes (microsomal fractions) from the osteosarcoma cells these precursors revealed apparent molecular masses of 85, 78, 56, 35 and 31 kDa. When osteosarcoma cells were cultured in the presence of warfarin, vitamin K-dependent 14C-labelling of the 78 kDa precursor was enhanced. Selective 14C-labelling of one precursor was also demonstrated in microsomes from HepG2 cells and from rat lung after warfarin treatment. In HepG2 cells this precursor was identified as the precursor of (clotting) Factor X. This unique 14C-labelling pattern of precursors of vitamin K-dependent proteins in microsomes from different cells and tissues reflects a new mechanism underlying the action of warfarin.

Antidotes↗
PubMed1990

Stabilization of the mRNA follows transcriptional activation of type II collagen gene in differentiating chicken chondrocyte.

The differentiation of chicken endochondral chondrocyte can be induced in vitro by transferring to suspension culture dedifferentiated chondrocytes grown as adherent cells. During the differentiation process, the synthesis of type I collagen is repressed while the genes encoding type II, IX, and X collagens are gradually activated. The changes in the steady-state levels of the mRNAs for type I, IX, and X collagens were shown to be fully accounted for by proportional modifications in the rates of specific gene transcription (Castagnola, P., Dozin, B., Moro, G., and Cancedda, R. (1988) J. Cell Biol. 106, 461-467). In the present report, we demonstrate that the cellular accumulation of type II collagen mRNA in differentiating chondrocyte is regulated not only at the transcription level but also through a stabilization of the RNA transcript as shown by the enhanced half-life of the mRNA in differentiated cells treated with actinomycin D. We also give evidence that this additional mechanism: 1) is specific for type II collagen, 2) does not occur at an early stage of differentiation when type II collagen mRNA starts accumulating, 3) affects only the cytoplasmic form of the RNA transcript.

Animals↗
PubMed1990

Phosphatidic acid and not diacylglycerol generated by phospholipase D is functionally linked to the activation of the NADPH oxidase by FMLP in human neutrophils.

It is widely accepted that the activation of the NADPH oxidase of phagocytes is linked to the stimulation of protein kinase C by diacylglycerol formed by hydrolysis of phospholipids. The main source would be choline containing phospholipid via phospholipase D and phosphatidate phosphohydrolase. This paper presents a condition where the activation of the respiratory burst by FMLP correlates with the formation of phosphatidic acid, via phospholipase D, and not with that of diacylglycerol. In fact: 1) in neutrophils treated with propranolol, an inhibitor of phosphatidate phosphohydrolase, FMLP plus cytochalasin B induces a respiratory burst associated with a stimulation of phospholipase D, formation of phosphatidic acid and complete inhibition of that of diacylglycerol. 2) The respiratory burst by FMLP plus cytochalasin B lasts a few minutes and may be restimulated by propranolol which induces an accumulation of phosphatidic acid. 3) In neutrophils stimulated by FMLP in the absence of cytochalasin B propranolol causes an accumulation of phosphatidic acid and a marked enhancement of the respiratory burst without formation of diacylglycerol. 4) The inhibition of the formation of phosphatidic acid via phospholipase D by butanol inhibits the respiratory burst by FMLP.

Butanols↗