R. Di Carlo

Prolactin protection against lethal effects of Salmonella typhimurium

The immunoregulatory role of prolactin (PRL) has been well established. In order to clarify if the hormone is also able to stimulate a protective activity against pathogens-induced infections we have studied the modifications of the infective capacity of Salmonella typhimurium induced in mice by repeated treatments with ovine PRL. A significant dose-dependent reduction in the mortality rate was observed in comparison to controls. This activity is probably related to the observed increases in phagocytosis and intracellular killing of the peritoneal macrophages and chemotaxis of the peritoneal granulocytes induced by the hormonal treatment. On the contrary, the number of leukocytes in blood was not modified by PRL treatment excluding a mobilization of cells from other districts. Our findings confirm the existence of a linkage between the neuroendocrine and immune systems suggesting a possible role for PRL in the regulation of non-specific immune response.

Effect of fumonisin B1 on inducible nitric oxide synthase and cyclooxygenase-2 in LPS-stimulated J774A.1 cells

Fumonisin B1 (FB1) is a water-soluble fungal metabolite that elicits a wide spectrum of toxicological effects. Cellular targets of FB1 include immune cells and in particular macrophages. In the present study the cytotoxic effect of FB1 (1-100 microM) was evaluated using a murine macrophage cell line (J774A.1) as model system. The effect of FB1 on nitric oxide (NO) and prostaglandin E2 (PGE2) production induced by lipopolysaccharide (LPS, 10 and 100 ng/ml) was also investigated. Macrophages were pretreated with FB1 for 72 h and then stimulated with LPS for 24 h. The increase of LPS-induced production of these inflammatory mediators was observed at increasing concentrations of FB1 (0.1-10 microM) and was found to be concentration dependent. By western blot analysis we demonstrated that the observed increase of NO and PGE2 production by FB1 was related to an enhancement of iNOS and COX-2 expression.

Effects of prolactin on rat paw oedema induced by different irritants

Evidence suggests that prolactin (PRL) may have a role in immune function, but no data exist on the possible interference between PRL and inflammatory processes, in spite of the known correlation between inflammatory and immune reactions. In the present study the activity of prolactin on rat paw oedema was investigated. Repeated administrations of ovine PRL or a hyperprolactinaemia induced by pituitary gland graft provoked an evident increase of the inflammatory response induced by carrageenan. This effect was also present when adrenalectomised animals were used. Indomethacin completely suppressed the proinflammatory effect of ovine PRL; bromocriptine reduced the paw oedema, but when both bromocriptine and PRL were administered the two opposite effects seem to annul each other. Also phospholipase A2-induced paw oedema was potentiated by PRL pretreatment and inhibited by bromocriptine, whereas in dextran or serotonin-induced paw oedema both PRL and bromocriptine were ineffective. A possible involvement of prostaglandins and/or of phospholipase A2 in the pro-oedemigenic activity of PRL is suggested.

The effect of age and sex on the expression of prolactin binding activity in the chicken bursa of fabricius

The binding of 125I-labeled prolactin (PRL) to membranes from the bursa of Fabricius of male and female chicks of different ages (15-30-45 and 60 days) was studied. In male chicks the binding was very low in 15 day-old animals and slightly increased in more aged animals. In female chicks the binding was more evident in young animals and decreased in 60 day-old animals. The binding showed a hormonal specificity and Scatchard analysis of the binding revealed the presence of binding sites with low capacity and high affinity. The presence of PRL receptors in the bursa of the chick, a structure that confers immunological competence to birds, gives further support to the involvement of the hormone in the immune processes.

Prognostic significance of prolactin receptor on overall survival of patients with early breast cancer: a long-term retrospective analysis

Abstract The value of prolactin receptor (PRLR) determination in predicting overall survival has been retrospectively evaluated in a group of 170 women bearing primary breast cancer stage I, II and IIIA. All patients underwent surgery (radical or modified mastectomy or quadrantectomy and axillary dissection followed by radiotherapy according to TNM stage) between January 1977 and December 1986. In all patients, oestrogen and progesterone receptors concentrations were also determined. Overall actuarial survival was higher in patients having PRLR positive tumours when compared to patients having PRLR negative tumours (p = 0.0126). No difference in survival was observed between oestrogen or progesterone receptor positive or negative patients. Using Coxs multivariate analysis on 164 patients, stage and PRLR status were the only significant prognostic factors affecting survival (p

Simple method of detecting enteroviruses in contaminated molluscs and sewage by using polymerase chain reaction coupled with a colorimetric microwell detection assay.

The methods normally used for the detection of enteroviruses in environmental samples involve the use of cell cultures, which are expensive and time consuming. The Polymerase Chain Reaction (PCR) is a useful tool for the detection of enteroviruses in several matrixes because primary cell culture is not needed and the increased sensitivity of PCR allows detection of the low numbers of target nucleic acids usually found in environmental samples. A 5-h, user-friendly PCR assay was used to detect enteroviruses in bivalves molluscs (clams) and sewage. Reverse transcription and amplification were performed in a one-step reaction using rTth polymerase. Carryover contamination was prevented with dUTP and uracil N-glycosylase. Detection was performed colorimetrically in a microwell titer plate. This method has greater advantages over conventional methodologies for routinely screening a large number of samples, namely, the rapid acquisition of results and cost effectiveness.

Comparative evaluation of the influence of some tetracyclines on chick embryo

Abstract To test the hypothesis that the tropism of tetracyclines for bone tissue is largely dependent on their affinity for calcium, a comparative study of the effects of 4 tetracyclines on the skeletal development of the chick embryo was performed. These were tetracycline, oxytetracycline, methacycline and doxycycline, possessing different degrees of affinity for divalent ions. Tetracycline, which has the highest degree of affinity for calcium, induced an appreciable reduction in skeletal development when injected into the yolk sac on day 4 of incubation. This reduction was less significant with equimolecular doses of oxytetracycline and methacycline, and even less with doxycycline, which among these 4 antibiotics has the lowest degree of affinity for calcium.

Effect of three derivatives of glutarimide on the epiphyseal cartilaginous disc of mice

Abstract Twenty successive daily doses of thalidomide, bemegride, or glutethimide, in equimolar dosages, were given to groups of young, male, albino mice. Half the number of mice in a group were sacrificed immediately at the conclusion of the series of doses, and the remaining animals were sacrificed 15 days later. Sagittal sections of the tibia were prepared to include the central area of the proximal epiphyseal disc. All three drugs produced alterations of a similar nature in the cartilaginous disc, namely, a reduction in thickness and a rarefaction of cells. However, in animals sacrificed immediately after treatment, these changes are confined to the zone of young, proliferating cartilage, whereas in animals sacrificed 15 days later, such changes are found in the zone of maturing cartilage while the zone of proliferating cartilage is not significantly modified.