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Biomedical subjects

E Ferrari

Publications and source records attributed to E Ferrari.

At least 163 records · Page 9Linked to original sources
PubMed1993

[Acute Staphylococcus aureus myocarditis in AIDS. 2 cases].

The authors report two cases of acute myocarditis due to Staphylococcus aureus in patients with AIDS. There was no history of opportunist infections in either case but the CD4 lymphocyte levels were very low. The myocarditis caused acute cardiac failure and death. Histological examination showed microabscesses filled with Gram positive cocci throughout the myocardium. Bacteriological studies identified the Staphylococcus aureus. Staphylococcus aureus myocarditis without endocardial or pericardial involvement is very rare. It is the result of septic emboli in the cardiac microcirculation. Bacterial myocarditis has rarely been diagnosed in HIV positive patients. Both our cases featured severe cell-mediated immunodeficiency without associated neutropaenia. The decreased bactericidal activity of the neutrophil polynuclears and/or a deficit in the immunity mediated by the B-cell lymphocytes in AIDS could explain the lethal septic complications observed in our two cases.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Malignant lymphoma in rheumatoid arthritis treated by low doses of methotrexate].

The authors report a case of non-Hodgkin's malignant lymphoma which developed in a patient under low-dose methotrexate for rheumatoid arthritis. Although rheumatoid arthritis without immunosuppressive therapy may be associated with an increased incidence of malignant lymphoma, the immunosuppressive effects of methotrexate may further promote the development of malignant lymphoma.

Aged↗
PubMed1993

[Mediators of the vascular endothelium as markers of myocardial ischemia and reperfusion].

Myocardial ischaemia may occur during spasm or thrombosis of the coronary arteries. The vascular endothelium plays an essential role in the lesions observed during ischaemia and myocardial reperfusion by the intermediary of the numerous endothelium-derived vasoactive factors. These include the "endothelium-derived relaxing factors" (EDRFs) nitrous oxide, prostacyclin, which are vasodilators and platelet antiaggregants ant the "endothelium-derived contracting factors" (EDCFs), endothelin, PGH2, oxygen-free radicals which are vasoconstrictive. The endothelial cells also produce the platelet activating factor and factors essential for coagulation. The metabolism and biological properties of these different mediators are reviewed. During the phenomena of myocardial ischemia-reperfusion, endothelial regulation is activated by tissue hypoxia and reduction of coronary flow and perfusion pressure. This regulation also depends on the functional state of the arteries (macroscopically normal or pathological). These vasomotor phenomena are associated with the effects of platelet aggregation and myocardial accumulation of neutrophil polynuclear blood cells. During the second phase of reperfusion cellular lesions are produced by the generation of cytotoxic oxygen-free radicals. Assays of mediators present a clinical interest when the modalities of sampling have been fixed (systemic blood samples or during cardiac catheterisation, sites of sampling, choice of timing of sampling with respect to the biological half lives of the mediators). Determining a correlation between the in vitro biological effects on those in isolated organs and clinical data has become possible with the improvement in techniques of sampling and the increasing collaboration between biologists and clinicians.

Endothelins↗
PubMed1993

Granulocytic-macrophagic and macrophagic colony stimulating factors elicit colonies of mast cells in mouse bone marrow agar culture. An electron microscope study.

Granulocytic-macrophagic colony stimulating factor (GM-CSF) and macrophagic colony stimulating factor (M-CSF or CSF-1) stimulate bone marrow cells of mouse to produce in semisolid agar colonies in which mononuclear cells were reported to be macrophages. We verified in such colonies the ultrastructure of the mononuclear cells which had cytoplasmic granules of the mast cells and lacked lysosomes, therefore we considered them as mast cells. However, the granules content did not reach the degree of condensation typically found in granules of mouse peritoneal mature mast cells. The mast cells of colonies obtained in agar can be mast cells arrested at some point in the maturative process, mast cells of a yet unrecognized type or cells with mast cells ultrastructural features which behave as precursors for cells of myeloid lineage.

Agar↗
PubMed1993

Nitrates improve detection of ischemic but viable myocardium by thallium-201 reinjection SPECT.

Thallium-201 reinjection imaging improves myocardial viability detection when compared to standard 3-4-hr redistribution imaging, however, the extent of ischemic but viable myocardium is still underestimated. We tested whether the sensitivity of reinjection imaging could be increased by giving nitrates postexercise to improve blood flow during the redistribution period. Twenty patients with coronary artery disease were included, 11 of them with a recent myocardial infarction. All patients underwent two exercise/4-hr redistribution 201Tl SPECT protocols: one with reinjection alone and the other with nitrates and reinjection. In the latter case, 20 mg of Isosorbide Dinitrate were given to patients immediately after postexercise imaging. Fifteen patients had reversible defects with reinjection alone, three additional patients were defined as ischemic with nitrates/reinjection protocol. Reinjection alone identified 41 reversible segmental defects, all except one were also evaluated as reversible with nitrates/reinjection. However, among the 54 segments showing fixed defects after reinjection only, 14 (26%) presented as reversible with the nitrates/reinjection protocol. The redistribution extent (segments/patient) was 2.05 +/- 0.41 segments with reinjection alone and 2.75 +/- 0.38 (p < 0.01) with nitrates/reinjection. In 15 patients showing reversible defects with both protocols, the redistribution extent was 2.73 +/- 0.41 segments with reinjection alone and 3.20 +/- 0.40 (p < 0.05) with nitrates/reinjection. Thallium-201 SPECT with nitrates and reinjection improves the detection of ischemic but viable myocardium in comparison to SPECT with reinjection alone.

Coronary Disease↗
PubMed1992

[Treatment of chronic heart insufficiency with dobutamine. Value and limitations].

Most positively inotropic drugs are available only as intravenous injection, which restricts their use in chronic heart failure. A single and brief infusion of dobutamine--a synthetic catecholamine and potent beta 1-adrenoreceptor agonist--provides a clinical improvement which may last for several weeks. On the other hand, tachyphylaxis to dobutamine may develop after a several days' infusion, so that the drug gradually loses its effectiveness. In patients with chronic heart failure, intermittent infusions of dobutamine result in sustained clinical improvement in more than 50 percent of the cases. The relative preservation of beta-adrenoceptors seems to play a role in the beneficial effects of intermittent infusions. The most significant side-effects of dobutamine are ventricular rhythm disorders. The practical applications and supervision of repeated dobutamine infusions in chronic heart failure are detailed.

Chronic Disease↗
PubMed1992

Plasmid transformation of Ruminococcus albus by means of high-voltage electroporation.

To apply recombinant DNA techniques to the genetic manipulation of cellulolytic ruminal bacteria, a plasmid vector transformation system must be available. The objective of this work was to develop a system for plasmid transformation of Ruminococcus albus. Using high voltage electrotransformation, pSC22 and pCK17 plasmid vectors, derived from lactic acid bacteria plasmids and replicating via single-stranded DNA intermediate, were successfully introduced into three freshly isolated R. albus strains and into R. albus type strain ATCC 27210. The optimization of the electrotransformation condition raised the electroporation efficiency up to 3 x 10(5) transformants per microgram of pSC22 plasmid.

DNA, Bacterial↗
PubMed1992

[Digital necrosis in Raynaud's phenomenon revealing a testicular seminoma. Value of prostacyclin].

A testicular tumour could be diagnosed by the occurrence of a Raynaud's phenomenon complicated by severe digital arteritis. The arteritis rapidly regressed under prostacyclin therapy. Such vascular manifestations are frequent in testicular carcinoma, but they usually develop after chemotherapy. To our knowledge, this is the first case where they preceded the diagnosis and specific treatment of a tumour of the testis.

Adolescent↗
PubMed1992

Synthesis of some carbamates of myo-inositol.

The syntheses are described of the 1-O-carbamoyl (11), 1-O-carbamoyl-2-O-stearoyl (10), 1-O-(acetylcarbamoyl)-2-O-stearoyl (12), 1-O-(heptylcarbamoyl) (13), 2-O-(heptylcarbamoyl) (14) 1,2-di-O-(heptylcarbamoyl) (15), and 1-O-(octadecylcarbamoyl) (16) derivatives of myo-inositol. None of these compounds had significant activity against phospholipase C.

Carbamates↗
PubMed1992

Four different DNA helicases from calf thymus.

Using a strand displacement assay we have followed DNA helicase activities during the simultaneous isolation of several enzymes from calf thymus such as DNA polymerases alpha, delta, and epsilon, proliferating cell nuclear antigen, and replication factor A. Thus we were able to discriminate and isolate four different DNA helicases called A, B, C, and D. DNA helicase A is identical with the enzyme described earlier (Thömmes, P., and Hübscher, U. (1990) J. Biol. Chem. 265, 14347-14354). The four enzymes can be distinguished by (i) their putative molecular weights after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, (ii) glycerol gradient sedimentation under low and high salt conditions, (iii) sensitivity to salt, (iv) binding to DNA, (v) nucleoside- and deoxynucleoside 5'-triphosphate requirements, and (vi) by their direction of movement. DNA helicase A unwinds in the 3'----5' direction on the DNA it was bound to, while DNA helicases B, C, and D do so in the 5'----3' direction. DNA helicase D, and to some extent DNA helicases B and C, are able to unwind long substrates of more than 400 nucleotides. Replication factor A, a single-stranded heterotrimeric DNA binding protein involved in cellular DNA replication and DNA repair stimulates the DNA helicases. The stimulatory effect is most pronounced on DNA helicase A, where replication factor A enables this helicase to unwind longer substrates. DNA helicases B, C, and D are also stimulated by replication factor A. The effect of replication factor A appears to be specific since corresponding single-stranded DNA binding proteins from Escherichia coli and bacteriophage T4 have no or even a negative effect on the four DNA helicases. Heterologous human replication factor A has no stimulatory effect on any of the four DNA helicases suggesting a species specificity of these interactions. Thus it appears that mammalian cells possess, as does E. coli, a variety of different enzymes that can transiently abolish the double helical DNA structure in the cell.

Adenosine Triphosphatases↗