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Biomedical subjects

S Roman

Publications and source records attributed to S Roman.

At least 91 records · Page 5Linked to original sources
PubMed1990

A case of erythrophagocytic T4 lymphoma. Immunological and morphological peculiarities.

One case of T-cell lymphoma with atypical malignant cells is reported. Some of the clinical features, morphological characteristics and functional activity (erythrophagocytosis) of malignant cells suggested malignant histiocytosis. The malignant disease started with splenomegaly and developed with hepatomegaly, bone marrow infiltration, discrete lymphadenopathy and leukaemic picture. Proliferated cells were characterized by ambiguity. In addition to phagocytic capability, presence of complement receptors and ultrastructural features proper to the macrophagic lineage, the cells expressed T-cell determinants (E receptors, T3, T4 and T11 antigens) and were peroxidase and esterase-negative. Erythrocytes were partially or completely dehaemoglobinized and presented the phenomenon of autolysis in different stages of development. Because this lymphoma is difficult to diagnose and apparently resistant to therapy, its recognition and further study are warranted.

Antigens, CD↗
PubMed1989

Tissue-type plasminogen activator (t-PA) and dilute blood clot lysis time in nephrotic patients.

When compared to normal weight normolipidemic control subjects, dilute blood clot lysis time was found to be obviously (p less than 0.001) prolonged in hypertriglyceridemic patients without proteinuria and slightly (p less than 0.05) accelerated in hyperlipidemic nephrotic patients in spite of their very high levels of plasma fibrinogen. As a result the ratio plasma fibrinogen (mg/dl) per clot lysis time (minutes) was 1.241 +/- 0.08 (X +/- SEM) in control subjects, 0.574 +/- 0.07 in hypertriglyceridemic patients and 2.69 +/- 0.172 in nephrotic patients. This finding suggesting that a larger amount of fibrin is rather readily dispersed from dilute blood clots of nephrotic patients was associated with higher levels of plasma t-PA:Ag (9.45 ng/ml +/- 1.18 in nephrotic patients versus 5.8 ng/ml +/- 1.23 in controls before venous occlusion and respectively 33.1 ng/ml +/- 3.83 versus 20.3 +/- 3.40 in controls after venous occlusion). Plasminogen activator activity of the euglobulins as assessed by the bovine fibrin-agarose plate was significantly higher in nephrotic patients only after venous occlusion. Plasma samples of nephrotic patients exerted a more potent inhibition of fibrinolysis in a urokinase activated system. This effect was, however, mainly due to the high levels of alpha 2 macroglobulin in nephrotic plasma which apparently have little influence on dilute blood clot lysis time.

Adolescent↗
PubMed1989

A particular case of large granular lymphocytes lymphoma.

A patient with non-cutaneous lymphocytic lymphoma with leukaemic spread is reported. The large majority of the peripheral blood mononuclear cells formed rosettes with sheep erythrocytes (E), had receptors for the Fc portion of IgG (Fc gamma R) and displayed an unusual enzymatic profile. Part of these cells had also labile bound surface membrane IgG. The leukaemic cells were morphologically characterized as large granular lymphocytes (LGL) and consisted of two different types of cells: lymphoid cells and monocytoid cells. The histopathological diagnosis was T-cell lymphoma, pleomorphic type, diffuse. Despite their morphological heterogeneity, all the proliferative cells had the same immunological phenotype, showed normal ADCC activity but no NK activity. After three months, without specific treatment, the surface pattern changed: the cells resembled mature LGL and the NK activity increased. The cytochemical study of the leukaemic cells revealed an enzymatical peculiarity: besides an enzymatic profile characteristic for relatively mature LGL, the cells also displayed peroxidase activity. This unusual aspect--the expression by an individual malignant cell of markers believed to be restricted to a single cellular lineage--might be interpreted as a lineage infidelity or lineage promiscuity. The observation that this lymphoma developed in a patient with a long history of hypogammaglobulinaemia is of particular interest.

Adult↗
PubMed1988

Modulation of Ig gene expression by Ig binding factors. Suppression of alpha-H chain and lambda-2-L chain mRNA accumulation in MOPC-315 by IgA-binding factor.

Previous reports by a number of laboratories have shown that Ig-binding factors may play a role in the regulation of Ig production by B cells. Although numerous studies have addressed the specificity and biologic function of Ig-binding factors at the cellular level, little information is available regarding the mechanism whereby Ig-binding factor modulates Ig production by B cells at the molecular level. Herein we have examined the specificity and molecular mechanism of the suppression of IgA production mediated by IgA-binding factor. Using the IgA-secreting plasmacytoma, MOPC-315, as a target cell, we have demonstrated that: 1) IgA-binding factor binds to IgA, but not to IgG, IgM, or BSA; 2) IgA-binding factor can suppress proliferation as well as IgA production by MOPC-315; 3) soluble IgA, but not IgG or IgM can inhibit the action of IgA-binding factor; 4) suppression of Ig production by IgA-binding factor is maximal within 8 to 12 h after exposure to the factor and is reversible; 5) IgA-binding factor suppresses IgA production by selectively down-regulating synthesis of IgA H and L chain proteins; 6) IgA-binding factor selectively suppresses transcription of alpha-H chain and lambda-2-L chain genes; 7) IgA-binding factor suppresses accumulation of c-myc mRNA. These findings suggest that IgA-binding factor binds selectively to surface IgA on MOPC-315 and suppresses IgA production by down-regulating transcription of H and L chain genes. Suppression of MOPC-315 proliferation by IgA-binding factor may be related to the concomitant down-regulation of the expression of the c-myc gene. c-myc is deregulated in MOPC-315 by virtue of the reciprocal 15:12 chromosomal translocation present in MOPC-315 where the c-myc gene is translocated and rearranged into the alpha-H chain gene complex. Simultaneous suppression of the expression of c-myc and alpha-H chain genes suggests that these two genes may be coordinately modulated, in plasmacytomas, by IgA-binding factor.

Animals↗
PubMed1988

[Revascularization in the acute phase of myocardial infarction. Study of left ventricular function in the 3d week and 6th month].

27 patients with primary myocardial infarction are treated, in the first 6 hours, with intravenous thrombolysis with immediate coronary angiographic control showing a patent artery in 76 p. cent of the cases. The treatment is completed with intracoronary thrombolysis (5 times) and transluminal angioplasty (6 times), enabling to obtain a patency rate of 88 p. cent. The overall left ventricular function is evaluated at D21 and in the 6th month (M6). Among anterior infarctions, those treated during the first three hours have a better ejection fraction (EF) at D21 than those treated later (40.3 p. cent +/- 6 versus 33.2 p. cent +/- -NS); this functional benefit is confirmed at M6 (42.8 p. cent +/- 12 versus 30.6 p. cent +/- 8; p less than 0.06). On the contrary, among inferior infarctions, the EF is comparable at D21 and M6 regardless of the early nature of the treatment. One patient died prematurely from a cerebral vascular accident which occurred during the thrombolysis. These results are in favor of a significant myocardial salvation in anterior infarctions revascularised at an early stage and of an active approach in order to obtain the most complete possible revascularisation.

Angioplasty, Balloon↗
PubMed1988

Influence of different indwelling lines on the measurement of blood cyclosporin A levels.

We studied in vivo and in vitro the possible influence of the indwelling line on the measurement of cyclosporin A (CSA) levels. CSA levels measured in samples taken from the catheter lumen used for CSA administration were significantly higher than those taken either from a second lumen or from a peripheral vein. Reversible fixation of the drug to the catheter walls might explain this alteration. The degree of fixation varies for different types of plastic material.

Bone Marrow Transplantation↗
PubMed1985

Clinical studies on plasma fibronectin and factor XIII; with special reference to hyperlipoproteinemia.

When compared to age-matched normal weight normolipidemic control subjects, plasma factor XIII, plasma fibronectin and serum cholinesterase levels were found to be markedly decreased in patients with decompensated cirrhosis of the liver, not significantly changed in hyperlipoproteinemia type IIa (heterozygous subjects) and increased in hypertriglyceridemic subjects (type IIb and IV) as well as in hyperlipidemic nephrotic patients. A possible accelerated hepatic synthesis of certain plasma proteins including factor XIII and fibronectin in patients with the nephrotic syndrome as well as in endogenous hypertriglyceridemia is envisaged. It is also considered that mural thrombi, richer in factor XIII and fibronectin, would be more resistant to fibrinolysis and more readily attached to subendothelial structures.

Adult↗
PubMed1985

Detection of human lymphocyte subpopulations by using monoclonal antibodies and protein A-coated erythrocytes.

The results obtained by using the protein A-rosette assay for human peripheral blood lymphocytes treated with a series of monoclonal antibodies were very close to the estimates obtained by indirect fluorescence. The percentages of T3-, T4-, T8- and DR-positive cells (T3 = T lymphocytes, T4 = helper T lymphocytes, T8 = suppressor T lymphocytes, DR = B, L and null cells) in normal and pathological peripheral blood were found to vary within the limits reported by many other authors using different techniques for the identification of cells binding the specific monoclonal antibody.

Animals↗
PubMed1984

Inhibition of salicylate binding to normal plasma by extracts of uremic fluids.

We previously reported that an extract of uremic plasma reduces binding of phenytoin and tryptophan by normal plasma and plasma albumin. This effect appears to reproduce the impaired binding of many drugs and several endogenous metabolites by uremic plasma. In the present study we further characterized the properties of extracts from uremic sera and body fluids using binding of salicylate as a model. Salicylate was chosen because it binds to both of the main albumin binding loci for aromatic, acidic drugs. Using a computer-assisted, least-squares, curve-fitting program, LIGAND, we found that the most satisfactory model for salicylate binding to 1:10 diluted normal plasma was a binding number (n) of 2 mol of salicylate per mole of albumin with an association constant (k) of 2.85 X 10(4) L/mol, an additional binding of 0.5 mol to other sites on albumin or to other proteins, and nonspecific binding of 21%. Addition of uremic pleural fluid extract to diluted normal plasma produced a monotonic decline in k to 0.17 X 10(4) L/mol with no change in n except possibly at the highest dose of uremic inhibitor. This pattern of competitive inhibition indicates presence of unknown ligands in the uremic extract that compete at both binding loci. More efficient extraction methods might also yield additional ligand(s) that inhibit through a noncompetitive mechanism.

Adult↗
PubMed1984

[Accentuation of myocardial ischemia during coronary recanalization in the acute phase of myocardial infarction].

Coronary recanalisation during the acute phase of myocardial infarction, especially by in situ infusion of thrombolytic agents, is accompanied in most cases by rapid regression of chest pain and a reduction in the degree of ST elevation. However, a multicentre retrospective study of 104 attempts at recanalisation, including 78 successful procedures, showed in 10 cases (12.8 p. 100), an apparently paradoxical accentuation of the chest pain with or without increased ST elevation, at the time of angiographically demonstrable recanalisation. This phenomenon may be interpreted as being the result of aggravation of the ischaemia of the border zone, the objective of therapy. Several pathogenic hypotheses, all with experimental proof, may be suggested to explain these observations (haemorrhagic infarction, non reperfusion, ischaemic contraction due to massive intracellular flow of calcium, etc.). It is usually associated with arrhythmias and may be considered to be a reliable sign of recanalisation. It may also explain certain cases of persistence of chest pain and ECG changes despite the demonstration of a permeable epicardial artery on initial coronary angiography.

Coronary Angiography↗
PubMed1983

Comparative behaviour of the components of the factor VIII complex in acute myocardial infarction.

The three components of the factor VIII complex: VIII coagulant (VIII:C), VIII related antigen (VIII R:Ag) and the VIII related von Willebrand factor (VIII R:WF) were studied in patients with acute myocardial infarction (AMI). Using a carefully standardized technique for the determination of VIII R:WF, a significantly higher R:WF level was found in 32 patients compared to 19 control subjects, confirming our previous results. However VIII R:AG was increased to an even greater extent, resulting in a VIII R:Ag/VIII R:WF ratio of 1.58 +/- 0.084 in patients, compared to 1.21 +/- 0.045 in controls. A similar increase of the VIII R:AG/VIII:C ratio was noted in the 13 patients in whom VIII:C was investigated. In 7 patients with severe AMI who could be investigated twice the plasma levels of both VIII R:Ag and VIII R:WF were found to be lower a week after the acute event than during the first 48 hours. However the VIII R:Ag/VIII R:WF ratio was not significantly reduced after 7 days. Acute phase reaction and endothelial injury resulting in release of multimers which are less polymerised are probably involved in the above changes.

Adult↗
PubMed1981

Increased plasma antithrombin III level in hyperlipidemic subjects.

When compared to values obtained in healthy normolipidemic normal weight control subjects, the plasma antithrombin III level determined by immunological, clotting and thrombin-agarose diffusion techniques was found to be obviously decreased in patients with decompensated cirrhosis of the liver and slightly but significantly increased in hyperlipidemic and especially in hypertriglyceridemic subjects. Plasma antithrombin III was positively correlated with serum cholesterol level, the logarithm of serum triglyceride concentration and serum pseudocholinesterase activity. A weaker correlation between plasma fibrinogen and antithrombin III was noted in the investigated clinical material. It is suggested that the accelerated fatty acid and lipoprotein turnover occurring in many subjects with type IIb and type IV hyperlipoproteinemia might be accompanied by an enhanced hepatic protein synthesis involving various liver secretion enzymes and clotting factors as well as antithrombin III.

Adult↗
PubMed1980

Increased ristocetin-cofactor in acute myocardial infarction: a component of the acute phase reaction.

When compared to the values obtained in healthy normal-weight, normolipemic controls, the plasma level of ristocetin-cofactor (VIII:R-cof.) was found to be much higher in patients with acute myocardial infarction and in postoperative conditions (4--5 days after a major surgical intervention). A lesser increase of VIII:R-cof. was noted in atherosclerotic patients without acute occlusive accidents and no significant changes of this plasma factor could be observed in hyperlipemic subjects without obvious clinical atherosclerosis. Serial studies emphasized a tendency towards normalization of plasma VIII:R-cof. as the acute phenomena of a myocardial infarction subsided. The above mentioned data suggest that the high levels of VIII:R-cof. recorded in myocardial infarction are mainly caused by a systemic acute phase reaction and to a lesser extent by endothelial damage. Delayed clearance of VIII:R-cof. subsequent to a hepatic dysfunction or to a modified pattern of protein metabolism during the above mentioned acute phase reaction might also contribute to the high level of this plasma factor.

Adolescent↗