Hepatitis C virus antibodies in dialysis pediatric patients.

A new 4-antigen recombinant immunoblot assay (4-RIBA) for confirmation of hepatitis C virus (HCV) C-100 enzyme-linked immunosorbent assay (ELISA) reactivity was tested in serum samples of 11 pediatric patients on dialysis. Of 6 HCV C-100 ELISA-positive samples, all were 4-RIBA positive. The 2nd generation ELISA picked up 1 additional case confirmed by 4-RIBA. The 2nd generation tests increased the prevalence of HCV-positive cases.

Lymphocyte subpopulations in pediatric age. Definition of reference values by flow cytometry.

In the present paper we have analyzed the age-related changes in the distribution and numbers per cubic millimeter of the circulating lymphocyte subpopulations. Lymphocyte subsets have been examined by monoclonal antibodies specific for surface antigens (namely CD2, CD3, CD4, CD8, CD16, CD20 and CD57) and flow cytometry in lysed peripheral blood of normal neonates (1-3 days old), 1-6 month, 7-12 month, 1-2 year old babies and 3-5 year, 6-10 year old children and young people up to 17 years of age. The results confirm the lymphocytosis at birth and at later stages of life and indicate that major changes in the distribution of lymphocyte subsets occur during the first two years of life; namely we have observed sharp increase of circulating B lymphocytes and prevalence of CD4+ T lymphocytes with high CD4/CD8 ratios in babies up to two years of age, compared to the values observed in normal adults. Very few CD8+ CD57+ lymphocytes were present at birth; cells bearing this phenotype appeared later in life. Lymphocytes expressing the CD16 antigen were already present in newborns. The authors discuss the functional meanings of the age-related changes observed in the distribution and in the numbers of circulating lymphocytes. The presented data represent valuable normal ranges of lymphocyte subsets to compare with values observed in sick babies or children.

[Endotoxin content of samples of pasteurized milk: preliminary findings]. / Sul contenuto endotossinico di campioni di latte pastorizzato: approccio preliminare.

By Limulus lysate assay, endotoxin was found in pasteurized milk samples from commercial source. The range was 32 to 128 microgram per ml, without any change when the samples were refrigerated. By contrast, the endotoxin content rose 512 to 2048 microgram per ml when milk was maintained at room temperature for 24 hours and 1024 to 6400 microgram per ml when samples were examined after 72 hours. These findings suggest a possible clinical implication, and support the concept that Limulus assay appears to be a rapid, reliable, and sensitive test for a quality control in commercial milk samples.

[Endotoxic contamination of biological products (ribosomal vaccines, viral vaccines and interferon)]. / Osservazioni sulla contaminazione endotossinica di alcuni prodotti biologici (vaccini ribosomiali, vaccini virali, interferon).

The A.A. have examined by the Limulus assay the possible endotoxin contamination in some biological products (ribosomal vaccines, viral vaccines, interferon). While the preparations of influenza vaccines and a partially purified fraction of ribosomal vaccine from Pseudomonas aeruginosa exhibit a gelation of lysate with high levels of endotoxin, rubeola vaccines, interferon and a purified fraction of ribosomal vaccine, presented a negligible amount of endotoxin. The results are discussed with the aim to examine the possible role of contaminating endotoxin in the mediation of some adverse effects and of the unsuspected extrinsic adjuvant activities developed in clinical and experimental use of these preparations.

[Endotoxemia and phagocytic function in premature infants. II. Role of the blood platelets]. / Endotossemia e funzione fagogitaria in soggetti immaturi. II.- Il ruolo delle piastrine.

The AA. have studied the relationship between endotoxaemia, detected in premature children and platelets function, according to the most recent finding, supporting the presence of specific receptors for endotoxin at the surface of thrombocytes. The finding of 6 positive Limulus test on platelets over 7 cases support the ability of clearance from platelets towards endotoxin. Furthermore, the AA. suggest that the presence of endotoxaemia in the plasma is due to an impairment of more complex mechanism, as liver's detoxification, which seems the most important.

[Bacteriocins as cytotoxic agents in experimental neoplasms: considerations on the role of possible contaminants]. / Le batteriocine come agenti citotossci nelle neoplasie sperimentali: considerazioni sul ruolo di possibili contaminanti.

In most recent papers some Authors have demonstrated that several bacteriocins are able to markedly inhibit the division of various neoplastic mammalian cell lines; also in vivo the inhibition of tumor growth or even regression relative to controls are statistically significant. Since such preparations are "crude" and it's possible that contaminating agents may represent a possible source of variability in the results, mostly in vivo; we have examined a preparation of Pyocin employed in this study for the possible endotoxin contamination using the Limulus assay. Such test was positive in triplicate and semiquantitative determination has shown and endotoxin amount of 5 to 10 microgram/ml. This level is, in vitro, not anough to give cytotoxic effect, but in vivo is able to influence experimental results. In addition, since some bacteriocins and enterotoxins are produced under exactly identical conditions, there is this a possibility that the enterotoxin are coproduced in these preparations and are causing some of the cytotoxic effects on experimental tumors. A more complete separation and purification of preparations will be required before definitive comments.

[Exerimental study of enterotoxic activity in some strains of Salmonella typhimurium: observations on the model of ADP-induced platelet aggregation]. / Contributo sperimentale allo studio dell'attivita enterotossica in alcuni stipiti di Salmonella typhimurium: osservazioni sul modello dell'aggregazione piastrinica da ADP.

In a previous report it has been shown that enterotoxin preparations (cholera and E. Coli) able to activate adenylatecyclase system, abrogated platelet aggregation induced by ADP. In the present study the same experimental model has been applied to some purified filtrates from Salmonella typhimurium strains. Preparations from 986 and TLM (invasive strains causing also fluid secretion) interfere with platelet aggregation, while 1027 strain (invasive but not evoking fluid secretion) didn't show such effect. It has been argued, as Sandefur and Peterson have demonstrated with different experimental models, that the system of platelet aggregation induced by ADP is valid for some strains of Salmonella typhimurium, which act with a mechanism partially involving adenylatecyclase system (i.g. cholera-like).

[Possible contamination of preparation of transfer factor with bacterial endotoxins]. / Considerazioni sulia possible contaminazione con endotossin batteriche di preparazioni di transfer factor.

In order to detect the possible contamination with bacterial endotoxins of some preparations of Transfer Factor, Limulus amebocyte lysate test was performed. The results obtained (TF preparations positive with L.T. for endotoxin assay) call sur detection to evaluate very carefully the immunologic responses in vitro ad in vivo, with these biological products contaminate can induce. In fact, bacterial endotoxins with their multiple potent effect on biologic system, represent a contant possible surce of variability in experimental biology and pathology.

[Endotoxemia and phagocytic function in premature subjects]. / Endotossemia e funzione fagogitaria in soggetti immaturi.

The AA. have evaluated some parameters of leukocyte function (phagocytosis, killing and nitroblu tetrazolium NBT test) from premature children, comparing such activities with endotoxemia, detected by means of limulus assay. The results obtained point out that there is not relationship between impaired leukocyte functions and endotoxemia.

[Verification of contamination with bacterial endotoxins in blood derivatives used in coagulative disorders: observations with the Limulus test]. / Sulla verifica della contaminazione con endotossine batteriche in emoderivati utilizzati nell'area coagulativa: osservazioni col limulus test.

The AA. expose the results of an investigation for an in vitro endotoxin assay by Limulus lysate test in blood products employed in coagulative area. The Limulus assay has been shown to be a simple, rapid, accurate and sensitive method of detecting bacterial endotoxin or endotoxin-like material in these biological products.

[Pilot study on the Limulus test and apyrogenic injectable preparations]. / Limulus test e preparazioni iniettabili apirogene studio pilota

After some notices on the Limulus amebocyte lysate test the AA. expose the results of an investigation for in vitro pyrogen detection in parenteral preparations.