[Predictive and diagnostic factors of malnutrition in hemodialysis patients]. / Fattori predittivi e diagnostici della malnutrizione nel paziente in trattamento emodialitico.

The relationship between malnutrition and inflammation is by now well established. IL-6 and, probably, other proinflammatory cytokines (mainly IL-1 and TNF) may represent the link between these two entities since these interleukins may promote loss of appetite, muscle protein breakdown and reduced hepatic synthesis of "negative" acute phase proteins like albumin, prealbumin and transferrin. IL-6 also stimulates up to 1000 fold the hepatic synthesis of "positive" acute phase proteins, mainly C-reactive Protein (CRP) and Serum Amyloid A. The association between CRP and cardiovascular mortality in the general population, as well as in haemodialysed uraemic patients, is well established. These crucial interrelationships have modified the interpretation of serum albumin concentration in the diagnosis of malnutrition; a reduced serum albumin concentration, in fact, in the presence of high CRP values should point towards a diagnosis of inflammation, though the inflammation may often induce weight loss or a condition of malnutrition. After switching most patients to a more biocompatible dialysis membrane and improvement of the quality of the dialysis fluid (by adopting hydrophobic filters at the water entry of dialysis devices and bicarbonate powder cartridges) nephrologists have focused their attention on other sources of inflammation (e.g. artificial vascular protheses, presence of infected thrombi, Clamidiae, Helicobacter Pilori, dental granulomas etc.). Starting from these assumptions the diagnosis of malnutrition, once focused mainly on serum albumin reduction, must be based on other parameters (clinical history of body mass wasting, dietary and anthropometric assessment, subjective global assessment, bioimpedance analysis etc.). All these investigations, however, must be examined together to obtain suitable information on the risk of malnutrition in dialysis patients. A comprehensive approach to malnutrition-inflammation in dialysis patients is the object of the present nephrology conference.

Effect of combined lysozyme and lipase treatment on the survival of Listeria monocytogenes.

The effectiveness of polyphosphates or lipases to increase the lytic activity of lysozyme was evaluated both on Listeria monocytogenes suspended in buffer and on growing cultures incubated at different temperatures. At 5 degrees C and 37 degrees C polyphosphates combined with lysozyme did not result in the decrease of the number of non-growing L. monocytogenes cells. At the same incubation conditions, the addition of lipase to lysozyme significantly enhanced the bactericidal activity of lysozyme to an extent determined by pH, NaCl concentration and temperature.

Distribution of F-specific bacteriophages and coliphages in wastewater.

A new method for quantifying F-specific bacteriophages in wastewater is described. Somatic coliphages were also determined. Host-strainSalmonella typhimurium WG 49 was sensitive to only a few bacteriophages and this could have arisen from infection by F-RNA phages. Host-strainEscherichia coli ATCC 9723 C, however, supported multiplication of a wide range of bacteriophages present in sewage, giving plaque counts one to three orders of magnitude greater than those on F(+) and F(-) salmonellas.

[Comparative evaluation of Escherichia coli strains as markers for the study of bacteriophages]. / Valutazione comparativa di ceppi di Escherichia coli come marcatori per la ricerca di batteriofagi.

The count of coliphages in polluted waters was found to be dependent on many experimental factors. The host-strain used for their enumeration is among the most important. In this paper we report a comparative investigation on the variability of counts of coliphages in sewage as a result of variations in host-strains of Escherichia coli and in methodologies. Two methods were used for enumerating them: the M.P.N. and the direct count. E. coli C, B1, Hfr and E36 consistently produced more plaques than any other host tested.