Comparison of the effect of dietary copper nanoparticles and one copper (II) salt on the metabolic and immune status in a rat model.

The aim of the study was to evaluate the effects of a diet containing different levels of Cu in two different chemical forms (carbonate and nanoparticles) on metabolic, immune and antioxidant status in a rat model. Five experimental treatments (8 rats in each) were used to test different dosages of Cu added to the diet (standard -6.5 mg/kg, half the standard dosage -3.25 mg/kg, and no added Cu as a negative control) and two sources of added copper (standard -CuCO3 and copper nanoparticles -CuNPs). Blood and urine samples were collected from all the animals after four weeks of treatment. Metabolic and immune parameters were determined in blood and urine samples. The study has shown that a dietary Cu deficiency (negative control) decreases rat's plasma levels of Cu, Fe, CREAT, BIL and IL-6, whereas reducing the level of Cu from the recommended 6.5 mg/kg to 3.25 mg/kg decreases only the plasma concentration of TG, IgE and IL-6. Replacing CuCO3 with CuNPs in rat diets affects their metabolism, as indicated by decreased Ca, CREAT, BIL, ALB and IL-6 plasma levels. To sum up, CuNP added to a diet of rats have a more beneficial effect on metabolic indices (indicative of kidney and liver function) and inhibit inflammatory processes more effectively than CuCO3.

Diagnostic and predictive value of skin testing in platinum salt hypersensitivity.

BACKGROUND: Hypersensitivity reactions to platinum salts are potentially lethal adverse events in chemotherapy, and often require its discontinuation. Several preventive procedures have been proposed: premedication, desensitization regimens, or replacement with a different platinum salt. OBJECTIVE: We therefore assessed the value of skin tests with platinum salts. A positive result would confirm their responsibility in hypersensitivity reaction, whereas a negative result would identify candidates for continuation of therapy using a different platinum salt. METHODS: Patch tests, prick tests, and intradermal tests with cisplatin, carboplatin, and oxaliplatin were performed in 21 patients. RESULTS: Skin tests were positive in 14 of 21 cases. Prick tests were positive in 5 cases with the suspected platinum salt. Intradermal tests were positive in 12 of 19 cases, always when the hypersensitivity occurred less than 2 hours after infusion. Cross-reactions were observed in 4 cases. Delayed readings of skin tests at 24 hours and 48 hours were positive in 3 patients. Patch tests were negative in all the 21 patients tested. Replacement with another platinum salt was performed in 13 patients using one that gave a negative skin test. A relapse of symptoms occurred in 1 patient. CONCLUSION: Intradermal tests are particularly indicated for the diagnosis of immediate hypersensitivity reaction. Their good negative predictive value allows safe retreatment by detecting a potential cross-reaction. CLINICAL IMPLICATIONS: The frequency of cross-reactions among cisplatin, carboplatin, and oxaliplatin has not been clearly established. Skin tests allow different platinum salts to be given and avoid discontinuation of chemotherapy.

Investigation of an unexplained skin disorder in a prison clinic in the Netherlands in 2002.

An unexplained outbreak of skin disorder with itching papules or pustules occurred among drugs body packers in a detention clinic in the Netherlands in October-November 2002. The descriptive cohort study suggests this outbreak could be associated with an expired batch of disposable linens, with an overall attack rate of 30% in the study population (n=118). No additionnal cases have been noted since this expired batch was replaced.

Exposure-effect relationship of platinum salt allergy in a catalyst production plant: conclusions from a 5-year prospective cohort study.

BACKGROUND: There is a high incidence of occupational asthma and rhinitis caused by platinum (Pt) salts in precious-metal refineries. OBJECTIVE: We sought to assess exposure to Pt salts and the incidence of Pt salt allergy in a catalyst production plant. METHODS: A 5-year prospective cohort study was performed in 159 catalyst production workers (94.6% of recruited), 50 craftsmen (92. 6% of recruited), and 66 control subjects (76.7% of recruited) at yearly intervals. Subjects were assigned to exposure categories of high levels of Pt (n = 115), persistently low levels of Pt (n = 51), intermittently low levels of Pt (n = 61), or no Pt (n = 48) after the initial survey according to job title and job location. Skin prick test conversion from a negative response to a 4 mm or larger wheal response with a 10(-2) mol/L hexachloroplatinic acid solution was chosen as the outcome variable. RESULTS: Exposure assessment of airborne Pt and Pt in the serum of workers demonstrated clear differences between exposure categories. The threshold limit value of 2 microg/m(3) for soluble Pt was exceeded in 3 (4%) of 78 measurements. Thirteen subjects assigned to high exposure showed skin test conversion, and new allergic symptoms were associated with exposure. Among the high-exposure category, the incidence rate of skin prick test conversion was 5.9 per 100 person-years for newly employed subjects (n = 79) and 2.1 per 100 person-years for those who had already been employed at the time of the initial survey (n = 36). A predicting factor for skin test conversion in highly exposed subjects was smoking status (relative risk, 3.9; 95% confidence interval, 1.6-9.7) but not atopy or bronchial hyperresponsiveness. CONCLUSION: Sensitization to Pt salts may develop in workers of catalyst production plants. Both the exposure to Pt salts and the incidence of Pt salt allergy were lower compared with reported data from precious-metal refineries.

Fluorescence polarization study of a salt bridge between a single-chain Fv and its antigen ribonuclease A.

The interaction between a single-chain Fv (sFv) of the monoclonal antibody 3A21 and its antigen, bovine pancreatic ribonuclease A (RNase A), was studied by site-directed mutagenesis of the hypervariable regions and fluorescence polarization analysis. The affinity constants of wild-type sFv and a mutant sFv D31A (Asp31 of heavy chain was replaced by Ala) for RNase A were found to be 2.7 x 10(7) and 4.7 x 10(6) M-1 in PBS at pH 7.2 and 37 degrees C, respectively. While the affinity constant of D31A is not affected by NaCl concentration, that of wild-type sFv is almost the same as that of D31A in the presence of more than 1 M NaCl. These results demonstrate that Asp31 of the heavy chain interacts electrostatically with a positively charged amino acid residue of RNase A.

Stable solid-phase Rh antigen.

Numerous investigators have attempted to isolate the Rh antigens in a stable, immunologically reactive form since the discovery of the Rh system over 56 years ago. We report here a successful and reproducible approach to solubilizing and adsorbing the human Rh antigen(s) to a solid-phase matrix in an antigenically active form. Similar results were obtained with rabbit A/D/F red blood cell antigens. The antigen preparation was made by dissolution of the red blood cell membrane lipid followed by fragmentation of the residual cytoskeleton in an EDTA solution at low ionic strength. The antigenic activity of the soluble preparations was labile in standard buffers but was stable in zwitterionic buffers for extended periods of time. Further studies showed that the antigenic activity of these preparations was enhanced, as was their affinity for plastic surfaces, in the presence of acidic zwitterionic buffers. Adherence to plastic surfaces at low pH maintained antigenic reactivity and specificity for antibody was retained. The data show that this approach yields a stable form of antigenically active human Rh D antigen that could be used in a red blood cell-free assay for quantitative analysis of Rh D antibody and for Rh D antibody immunoadsorption and purification.