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Biomedical subjects

P Mastroeni

Publications and source records attributed to P Mastroeni.

At least 91 records · Page 5Linked to original sources
PubMed1983

Antidipsogenic effect of endotoxin in the rat.

Escherichia coli LPS (640-1280 mcg/Kg, intravenously) showed a powerful, dose-dependent and long-lasting inhibitory effect on drinking behavior stimulated by 48 h water deprivation, subcutaneous injection of isoprenaline (33.3 mcg/Kg) and intracerebroventricular injection of hypertonic NaCl (2.9%) solution, carbachol (250 ng) and angiotensin II (100 ng). The antidipsogenic effect was neither a consequence of behavioral alterations, nor due to endotoxin peripheral vasodilating activity. Naloxone (60-120-240 mcg/Kg, subcutaneously) did not influence endotoxin inhibition of water intake, thus ruling out an endorphin-mediated effect. When prostaglandin synthesis was inhibited, the effect of endotoxin was reduced. Since prostaglandins do not seem to be involved in the regulation of thirst, the mechanism of the antidipsogenic effect elicited by endotoxin needs further study.

Angiotensin II↗
PubMed1983

Enzyme-linked immunosorbent assay (ELISA) for streptokinase antibodies.

A micro plate Enzyme-linked immunosorbent assay (ELISA), developed for detection of antibodies to Streptokinase, was used to analyze 80 human sera. The aim was to provide a simple method for antibody screening that required neither sophisticated equipment nor a high degree of technological skill. Preliminary results show that ELISA is specific, reproducible and sensitive. Comparative evaluation of the ELISA and the coagulum lysis test for antibodies against streptokinase show excellent correlation. We also evaluated the anti-Streptolysin O titer either by conventional method or ELISA. The sensitivity of ELISA for detecting anti-Streptolysin O antibodies was 3-4-fold higher than that of the hemolytic test. The sensitivity of ELISA for detecting anti-streptokinase antibodies was 10-20-fold higher than that of the coagulum lysis. The Enzyme-linked immunosorbent assay seems to offer some advantages over the more commonly used coagulum lysis test as far as sensitivity is concerned and potentially it is suggested that this method could be usefully employed clinically in human streptococcal infections.

Adult↗
PubMed1982

Structure-activity relationships of new antiviral compounds.

In preliminary experiments, the compound 2-amino-5-(2-sulfamoylphenyl)-1,3,4-thiadiazole (G413) was shown to possess high activity against DNA viruses (herpes simplex viruses 1 and 2 and adenovirus 17) and RNA viruses (poliovirus 1, echovirus 2, and coxsackievirus B4). Experiments on the replicative cycle of poliovirus 1 and production of infectious RNA viruses demonstrate that this compound probably prevents assembly of virus particles by acting on structural proteins. In the present experiments, results concerning the activity of derivatives of G413 after side-chain modification are reported. Modification of the primary amine H to CH3 or CH2-CH = CH2 produced a loss of activity against DNA viruses, but inhibitory action on RNA viruses was preserved. Modification to CH2CH3 resulted in the loss of antiviral activity.

Antiviral Agents↗
PubMed1981

Behavioural and body temperature effects of meningococcal lipopolysaccharide after intraventricular injection in adult fowls Gallus domesticus.

The effects of the meningococcal lipopolysaccharide (LPS), given into the II cerebral ventricle of adult fowls, were studied on behaviour and body temperature. Immediately after the administration a marked and dose- dependent behavioural sedation or sleep lasting over 2 hours or more according to the dose was observed. The body temperature effects of LPS were biphasic, i.e. and immediate initial phase of hypothermia lasting about 100 min, followed by a longer-lasting fever response. A pretreatment with phentolamine, an antagonist at alpha-adrenoceptors prevented the hypothermic phase following the endotoxin administration. In conclusion, present experiments show that in comparison to 0-somatic antigen of Shigella dysenteriae, meningococcal endotoxin possesses more marked behavioural effects and a different profile in body temperature effects.

Animals↗
PubMedDate not supplied

Different effects of bacterial lipopolysaccharide on superoxide anion production by macrophages from normal and tumor-bearing rats.

Bacterial endotoxins or lipopolysaccharides (LPS) exhibit a wide range of modulatory activities on immunocompetent cells. Among the numerous effects of LPS on macrophages, an enhancement of superoxide anion (O2-) release has been reported. In previous studies carried out on tumor-bearing rats, it was found that several functions of peritoneal macrophages such as phagocytic, microbicidal and antiviral activities were depressed. In this paper we evaluated the spontaneous or phorbol myristate acetate (PMA)-induced production of superoxide anion by macrophages from tumor-bearing rats with respect to controls. Moreover, the effect of in vitro priming with LPS on O2- production by the same cells was studied. It was found that the pattern of superoxide release by macrophages from tumor-bearing rats is significantly different from controls. Preincubation of macrophages from normal rats with LPS enhanced the spontaneous and PMA-induced production of O2-. In contrast, the same concentrations of LPS did not prime macrophages from tumor-bearing rats.

Animals↗
PubMedDate not supplied

Effect of oral administration of a variety of bacteria on depressed macrophage functions in tumour-bearing rats.

In consideration of the well documented influence of normal microbial flora on the level of activation of macrophages, we evaluated the effects of oral administration of bacteria on rats with depressed macrophage functions. An oral, killed polyvalent vaccine (Diplococcus pneumoniae types I, II and III, Streptococcus haemolyticus, Staphylococcus aureus and Haemophilus influenzae), the live lyophilized Streptococcus faecium and spores of Bacillus subtilis, respectively, were administered orally to immuno-depressed rats. Results demonstrate the restoration of phagocytosis, intracellular killing and the chemotactic activity of macrophages. These experimental observations suggest that bacterial flora associated with mucosae can influence the level of activation of peritoneal macrophages.

Administration, Oral↗
PubMedDate not supplied

Impairment of macrophage antiviral activity by soluble tumor products. Effects of bacterial immunomodulators.

The antiviral activities of normal rat peritoneal macrophages versus Herpes Simplex Virus type 1 were inhibited by sera from tumor-bearing rats and 3M KCl extracts of tumor mass. The inhibitory activity was demonstrated on the extrinsic as well as on the intrinsic macrophage functions. Sera from Corynebacterium parvum and Listeria monocytogenes treated tumor bearing rats did not inhibit these macrophages functions. Furthermore the 3 M KCl extracts from the tumor mass of the above treated TBR show a decrease in the capability to impair these macrophage functions. On the other hand, the treatment with the oral polyvalent adjuvant "Buccalin" was not able to restore the compromised antiviral activity in tumor bearing rats.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Evaluation of anti-HAV IgG on 2 samples of closed populations].

The authors have carried out an epidemiologic research about the diffusion of antibody to hepatitis A antigen in the inhabitants of Ginostra, fraction of Stromboli, and Alicudi Islands (Eolie's arcipelago). We have examined by ELISA 86 human sera. We have detected a percentage of positivity about 82 and 70.6% for two populations. A critic examination of the results with parameters auxiliary (sex, age), showed significant differences of positivity about two different sexs and ages.

Age Factors↗