Down-modulation of nuclear localisation and pro-fibrogenic effect of 4-hydroxy-2,3-nonenal by thiol- and carbonyl-reagents.

Among the oxidative breakdown products of omega-6 unsaturated fatty acids, the aldehyde 4-hydroxy-2,3-nonenal (HNE) is receiving increasing attention for its potential pathophysiological implication, which at least partly lies on the demonstrated ability to modulate gene expression of a number of genes. Here we show that a marked down-modulation of HNE nuclear localisation in cells of a macrophage line (J774-A1) can be afforded by treatment with sulfydryl and carbonyl reagents without significantly interfering with cell viability. As regards the addition of thiol-group reagents to the cell suspension, N-ethylmaleimide (NEM) led to a sustained decrease of HNE nuclear localisation, while 4-(chloromercuri)-benzene-sulfonic acid (PCMBS) gave a similar but more transient effect. Hydroxylamine (HYD), a carbonyl-group reagent, was also able to inhibit HNE nuclear localisation. The actual efficacy of the inhibitors used was then tested on the HNE-induced stimulation of transforming growth factor beta1 (TGFbeta1) production by J774-A1 cells. Indeed, the thiol reagents NEM and PCMBS, both markedly down-modulating HNE nuclear localisation, were able to inhibit HNE-induced increase of TGFbeta1 protein synthesis. The carbonyl reagent HYD was less effective on this respect, producing strong but incomplete protection against HNE-induced TGFbeta1 increase. Taken together, the results indicate that sulfydryl groups are involved in the process of HNE cellular internalisation, while both sulfydryl and carbonyl groups are involved in the process of HNE nuclear translocation, and consequently in the modulation of gene expression by the aldehyde. Further, an actual demonstration is provided that HNE-induced effect on gene regulation can be efficiently counteracted by suitable interference with HNE biochemistry.

Calcyclin gene expression modulation by medroxyprogesterone acetate.

Calcyclin is a cell-cycle-related gene corresponding to a calcium-binding protein whose expression is mainly controlled by platelet-derived growth factor. This paper illustrates medroxyprogesterone acetate (MPA) inhibition of endogenous calcyclin RNA expression of both estrogen-dependent human mammary carcinoma cells and estrogen-independent hamster fibroblasts. Transfection of fragments of the calcyclin promoter driving the chloramphenicol-acetyl-transferase (CAT) gene into hamster fibroblasts was used to evaluate the hormone sensitivity of different promoter regions by considering calcyclin expression at both the RNA and protein level, as evaluated by the CAT assay. A 164 bp promoter fragment showed a good activity that was inhibited by MPA, thereby confirming the results of the observation of endogenous calcyclin gene: smaller fragments, however, required cotransfection of progestin receptor to show full activity, with MPA displaying a stimulatory effect. These findings show that progestin modulation of calcyclin gene expression may be independent of progestin receptors, and that MPA has opposite effects on different promoter regions.

Heparin neutralizes serum antiplasmin inhibition of peripheral blood leukocyte fibrinolytic activity.

Serum inhibition of peripheral blood fibrinolytic activity has been evaluated with the 125I-fibrin coated well method. The inhibitory activity was found in a 140,000 d serum fraction that contained alpha 2-antiplasmin. Addition of heparin to cell cultures at concentrations in the range of values obtained during anticoagulant therapy has been demonstrated to counteract such inhibitory activity. The phenomenon has been shown to be linked with plasminogen activation in the presence of fibrin, to lead to a weakening of antiplasmin activity. By clarifying an important aspect of the mechanism of heparin action, our findings support the view that heparin can be usefully employed in treating thrombotic syndromes, not only as an anticoagulant, but also as a "profibrinolytic" agent.

Correlation between pS2 protein positivity, steroid receptor status and other prognostic factors in breast cancer.

The cytosolic levels of pS2, an estrogen-regulated protein, were measured in 100 cases of primary breast cancer and related to several conventional histological and biochemical prognostic factors. The data were statistically analyzed on the basis of two different cutoff point for pS2: 4 and 11 ng/mg of cytosolic proteins. pS2 positivity (cutoff 11 ng/mg) was shown to be associated with small tumor size (p = 0.05), a higher differentiation grade (p = 0.007) and a smaller number of mitoses (p = 0.004), but not with menopausal status, lymph node involvement, cathepsin D levels, or proliferative activity determined by the monoclonal antibody Ki67. With the cutoff of 4 ng/mg, the statistical significance was confirmed only for the number of mitoses (p = 0.03), which was also the most closely related covariate in multivariate analysis (p = 0.008). As regards steroid receptor status, a significant difference was observed between pS2+ and pS2- cases (Chi-square = 8.9; p = 0.04, cutoff 4 ng/mg). in conclusion, pS2 positivity, being preferentially expressed in hormone-dependent cells and related to other well-known positive markers, may either indicate a good prognosis or predict responsiveness to endocrine treatment.

[Cryptococcosis in a female patient with angioimmunoblastic lymphadenopathy and dysproteinemia]. / Criptococcosi in una paziente affetta da linfoadenopatia angioimmunoblastica con disproteinemia.

A case of a 72-year-old woman affected by angioimmunoblastic lymphadenopathy with dysproteinemia is described. She was admitted to the hospital for serious cutaneous lesions and dementia. The patient had been treated with corticosteroids for the previous two years. Cryptococcosis was diagnosed by cutaneous biopsy. Antimycotic therapy together with corticosteroid withdrawal cured the cutaneous lesions and improved her psychiatric symptoms.

Insulin modulates human mononuclear adherent cell fibrinolytic and phagocytic activities.

The effects of physiological concentrations of insulin on the fibrinolytic activity of peripheral blood leucocytes were investigated. Significant enhancement of the fibrinolytic activity of mononuclear adherent cells was observed, whereas lymphocytes and granulocytes were unaffected. Furthermore, insulin stimulated mononuclear adherent cells to phagocytize inert particles but not to secrete lysozyme. It is suggested that these results are attributable to the large number of insulin receptors present on the monocyte membrane, and that the regulatory mechanism of fibrinolysis and phagocytosis differs from that controlling the secretion of lysozyme.

[Fibrinolytic activity of human peripheral blood granulocytes]. / Attivita' fibrinolitica dei granulociti di sangue periferico umano.

The fibrinolytic activity of human peripheral blood leukocytes was studied by plating the cells on 125I-fibrin coated dishes. The separation of the three major leukocyte types allowed to demonstrate that most of the activity was produced by granulocytes. The rate of fibrinolysin was found to be linear with incubation time and cell number in the range of 1-4 X 10(5) cells/ml. Since little activity was found in absence of exogenous plasminogen, it was concluded that the cell fibrinolytic activity depended mostly upon the release of plasminogen activator. Plasmatic and granulocytic activators obtained from the same amount of blood were found to be of similar level suggesting a possible clinical implication of the cellular activity in the thrombolytic system.

[Changes of fibrinolytic activity of human HL60 acute leukemia cells responses to chemically induced differentiation]. / Modificazioni dell'attivita' fibrinolitica di cellule di leucemia acuta umana della linea HL 60 in risposta ad agenti promoventi la differenziazione.

The fibrinolytic activity of human acute leukemia HL 60 and K 562 cells was studied by the (I25)I-fibrin plate method. The treatment of this cell lines with chemical inducers of differentiation such as Dimethyl sulfoxide (DMSO), 12-0-tetradodecanoilphorbol 13-acetate (TPA), and retinoic acid was found in some instance to affect such fibrinolytic activity. Increased activity was found during the myeloid differentiation induced by retinoic acid of HL 60, while the DMSO, another inducer of myeloid differentiation, and TPA, an inducer of macrophagic differentiation, both produced a decreased of the lytic activity. In the treatment with retinoic acid of th K 562 cells, which do not differentiate by such compound, we failed to show an increase of the fibrinolytic activity. Our data suggest that changes of the fibrinolytic activity of HL 60 are related to the process of differentiation.

[Mathematical models in epidemiology: Study on viral hepatitis in Italy (author's transl)]. / Modelli matematici in epidemiologia: studio dell'epatite virale in Italia.

In this paper a mathematical approach to the epidemics is proposed. The method is based upon a model able to describe any time-depending phenomena using the following elements: "class", "transition" and "related probability". The solution of the differential equations describing the model are obtained: first, by numerical techniques; second, by a Montecarlo simulation method. Deterministic and stochastic solutions which have been obtained, by applying the model to the study of viral hepatitis in Italy during 1960--1970, have been compared each other, to improve the model itself.