Tumor antigen-specific CD4+ T cells in cancer immunity: from antigen identification to tumor prognosis and development of therapeutic strategies.

CD4(+) T cells comprise a large fraction of tumor infiltrating lymphocytes and it is now established that they may exert an important role in tumor immune-surveillance. Several CD4(+) T cell subsets [i.e. T helper (Th)1, Th2, T regulatory (Treg), Th17, Th22 and follicular T helper (Tfh)] have been described and differentiation of each subset depends on both the antigen presenting cells responsible for its activation and the cytokine environment present at the site of priming. Tumor antigen-specific CD4(+) T cells with different functional activity have been found in the blood of cancer patients and different CD4(+) T cell subsets have been identified at the tumor site by the expression of specific transcription factors and the profile of secreted cytokines. Importantly, depending on the subset, CD4(+) T cells may exert antitumor versus pro-tumor functions. Here we review the studies that first identified the presence of tumor-specific CD4(+) T cells in cancer patients, the techniques used to identify the tumor antigens recognized, the role of the different CD4(+) T cell subsets in tumor immunity and in cancer prognosis and the development of therapeutic strategies aimed at activating efficient antitumor CD4(+) T cell effectors.

Composition and calcium status of acid whey from pasteurized, UHT-treated and in-bottle sterilized milk.

Whey extracts were obtained from pasteurized, UHT-treated and in-bottle sterilized milks. After acidic precipitation of casein the concentration of protein, NPN, lactose, lipid, calcium, magnesium and potassium was determined. Among the parameters examined, protein content was significantly reduced in the whey extracts from UHT-treated and in-bottle sterilized milks compared with that from pasteurized milk, while lactose content was increased. Calcium extracted in whey was at least 80% of total calcium of the milk. The total calcium to protein ratio of whey was increased as a function of the thermal treatment of milk, while ionic calcium was about 50% of total calcium in all whey extracts. In vitro protein digestibility was found to be significantly lower in whey from UHT-treated and in-bottle sterilized milks than in that from pasteurized milk. Parallel estimation of the percentage of ionic calcium and of the solubility of proteins in the pH range 2-10 indicated that calcium was not involved in the pH-dependent solubility of proteins extracted in the whey, the extent of solubility being essentially a function of the thermal treatment of milk. The results suggest that calcium was not responsible for the formation of soluble protein macroaggregates with impaired digestibility that are present in whey from milk subjected to heat treatment of increasing intensity.

Results of a national epidemiological investigation on HCV infection among dialysis patients. (Survey by the Italian Branch of EDTNA/ERCA).

The Italian Branch of EDTNA-ERCA organised a retrospective epidemiological investigation on the spread of HCV infection in dialysis. A questionnaire was sent to 830 Italian dialysis centres to collect information about prevalence and incidence of HCV infection among patients and staff, anti-HCV testing, presumed sources of infection, sanitation procedures and dialysis strategies adopted to prevent or reduce the transmission of HCV infection. Twenty-seven percent of the dialysis centres responded to the questionnaire. The answers confirmed the decline in HCV prevalence and incidence. At variance with official health organisation recommendations, isolation of anti-HCV-positive patients is still used in many centres (25%) despite the fact that it is not advisable in view of the high cost and uncertain benefit. Dedicated machines for anti-HCV-positive patients should be adopted, at least in units with a high prevalence of these cases.

Results of a national epidemiological investigation of HCV infection in dialysis patients.

The Italian Branch of EDTNA/ERCA organised a national, epidemiological, retrospective study to collect data and implement preventative measures for the spread of HCV infection in dialysis units. A questionnaire was sent to staff in 830 dialysis centres to collect information relating to 1996. Data are presented on incidence/prevalence of HCV infection, antibodies, viraemia and mortality, and comparison of the management of HCV between centres. At variance with the recommendations of the Official Health Organisations, dedicated machines and separate rooms are used in many centres and this paper concludes with recommendations for units, in particular those units with a low prevalence of anti HCV positive patients.

HIV and dialysis: is it a real risk?

The need to expound this work was born of the necessity to confront all the organisational difficulties that present themselves with the arrival of a HIV+ patient for dialysis in our centre. On such occasions, in fact, we were unable to find a protocol, guidelines or a text that could help us in a complete and adequate way, to resolve the doubts, the fears and the practical, ethical and legal problems that we suddenly had to face.

Heavy metal toxicity following apical and basolateral exposure in the human intestinal cell line Caco-2.

Caco-2 is a cell line, derived from a human colon carcinoma, that retains the ability to differentiate in culture into absorptive intestinal cells. Caco-2 cells were used to evaluate the toxicity of three heavy metals-the essential trace elements zinc and copper, and the xenobiotic cadmium. The cells were cultivated on permeable filters until differentiated and were then exposed to the metals either from the apical (luminal) or from the basolateral (serosal) side. Toxicity was measured in dose-effect experiments with reference to cell survival and integrity of the cell monolayer. The metals were more toxic when presented to the basolateral than to the apical cell side. The toxicity ranking was cadmium > > copper > zinc. The cell's ability to transport each metal across the monolayer and the resulting intracellular accumulation could account for the cytotoxic effects. A specific toxic effect observed on a specialized function of these cells was the interference of cadmium in tight-junction integrity as shown by changes in the transepithelial electrical resistance, in the rate of transport of a specific marker across the cell monolayer, and by morphological alterations of the tight junctions.

Evaluation of an HPLC method for the determination of sulphiting agents in foods.

A method based upon a combination of a modified Monier-Williams procedure and an HPLC separation and quantitation of sulphite, has been developed. Its efficiency has been tested, in comparison with the Monier-Williams method, for the SO2 recovery in various foods. Desorption of SO2 from different matrices is obtained by distillation in strongly acid solution. Gaseous SO2, collected and oxidized to sulphate with hydrogen peroxide, is neutralized with sodium hydroxide. The neutralized solutions are diluted and injected by an autosampling injector into an HPLC apparatus consisting of a strong anion exchange column, eluted with a potassium hydrogen phthalate solution (0.15 g/l, pH 5.7) at a 3 ml/min flow rate and detected at 280 nm by an UV spectrophotometer. The combined method shows a good detection limit as well as high chromatographic resolution, avoiding potential interference of other volatile compounds. It is also time-saving and utilized basic laboratory equipment.