Stable isotope relationships between apatite phosphate (δ18 O), structural carbonate (δ18 O, δ13 C), and collagen (δ2 H, δ13 C, δ15 N, δ34 S) in modern human dentine.

RATIONALE: The use of multi-isotopic analysis (δ2 H, δ13 C, δ15 N, δ18 O, and δ34 S values) of modern human body tissues for provenancing of unknown individuals in forensics is increasing. Tooth dentine develops during childhood and adolescence, therefore providing geographical information from that period of life. Tooth apatite δ18 O values are commonly used for the reconstruction of drinking water values, and H-C-N-S isotope ratios in collagen supply additional information about the composition of diet. We tested if dentine collagen δ2 H values provide similar information to apatite δ18 O values with a proof-of-concept study. METHODS: Tooth samples were taken from modern-day individuals born in different regions of the world. Apatite and collagen were prepared from dentine. Stable isotope analyses were performed on apatite phosphate oxygen (δ18 Ophos ); oxygen and carbon of the structural carbonate (δ18 Ocarb , δ13 Ccarb ); and hydrogen, carbon, nitrogen, and sulfur of the collagen (δ2 Hcoll, δ13 Ccoll , δ15 N, δ34 S). RESULTS: δ18 Ophos , δ18 Ocarb , and δ2 Hcoll values are highly correlated in modern human dentine. There are significant relationships of δ18 O values in the apatite fraction and δ2 H values in the collagen fraction with local δ18 O and δ2 H precipitation values, respectively. Pearson correlation coefficients indicate no direct relationship between δ15 N values and the isotope ratios of any other element. Weak relationships exist between collagen δ34 S values and δ18 Ocarb or δ18 Ophos values. CONCLUSIONS: The highly significant correlation of δ18 Ophos , δ18 Ocarb , and δ2 Hcoll values in the modern human dentine implies that measurement of δ2 H values in collagen or δ18 O values in bioapatite will provide reliable information about the climate at the person's whereabouts.

Identification and quantification of the sea spray effect on isotopic systems in α-cellulose (δ13C, δ18O), total sulfur (δ34S), and 87Sr/86Sr of European beach grass (Ammophila arenaria, L.) in a greenhouse experiment.

The sea spray effect can severely influence the isotopic signature of terrestrial individuals in coastal regions. To further specify this effect, beach grass was grown in a greenhouse under controlled environmental conditions and sprayed with mineral salt solution containing different mineral salts but only traces of NaCl (group 1). Another group of plants was sprayed with salty water from the Schlei inlet and the Baltic Sea, respectively (group 2). Control plants were only sprayed with tap water. Isotope analyses were conducted on the unwashed and washed plants (δ13Ccellulose, δ18Ocellulose, δ34Stotal S, 87Sr/86Sr), soil (δ18Osulfate, δ34Ssulfate, 87Sr/86Sr), and spray as well as irrigation water (δ18Osulfate, δ34Ssulfate, 87Sr/86Sr). Moreover, elemental analyses were performed on the water samples. The sea spray effect was visible in all isotopic systems under study. The uptake of SO42-, HCO3-, and Sr2+ directly affected plants of group 1, while plants of group 2, sprayed with salty water, additionally showed salinity stress in the case of α-cellulose and total sulfur due to biochemical reactions of the plants. Very high concentrations in HCO3- or SO42- also affected the plants' isotopic signatures. The impact of the sea spray and additional stress reactions were quantified. Our study is the first experiment creating an artificial sea spray effect in a greenhouse. This experiment for the first time enables the identification and quantification of the sea spray effect in environmental samples. The marine signature taken up by the plants and recorded by the investigated isotopic systems is apparently high and should have an impact on the isotopic fingerprints of animal consumers at the coast, as evidenced for archaeological animals from the Viking Haithabu and the early medieval Schleswig sites located close to the Baltic Sea. This result demonstrates the potential of greenhouse experiments as an isotopic predictor of the past local sea spray effect.

Pegylated interferon-alpha for the treatment of sexually transmitted acute hepatitis C in HIV-infected individuals.

BACKGROUND: Sexually transmitted acute hepatitis C among HIV-positive homosexual men has been noted as an emerging epidemic. METHODS: Forty-seven patients with mainly sexually acquired, acute hepatitis C were enrolled in this prospective, multicentre trial, and 36 of these patients were treated within the acute phase of hepatitis C infection with pegylated interferon (peg-IFN) therapy. RESULTS: Early treatment resulted in sustained virological response in 61% of patients. Peg-IFN alone showed similar treatment response rates and lower incidence of anaemia compared with peg-IFN+ribavirin combination therapy. Higher treatment response rates were observed in patients treated over 48 weeks compared with 24 weeks. CONCLUSIONS: Treatment of hepatitis C in HIV-positive individuals in the acute phase of infection leads to high rates of sustained virological response. Optimal time and mode of therapy have yet to be defined.

Effect of the interleukin-6 C174G gene polymorphism on treatment of acute and chronic hepatitis C in human immunodeficiency virus coinfected patients.

UNLABELLED: Hepatitis C virus (HCV)/human immunodeficiency virus (HIV) coinfection poses a difficult therapeutic problem. Response to HCV-specific therapy is variable but might be influenced by host genetic factors, including polymorphisms of cytokine genes. Here, we studied whether interleukin-6 (IL-6) C174G gene polymorphism affects the response to antiviral treatment in HCV-infected HIV-positive subjects. We determined IL-6 genotypes in HIV-positive patients with acute (n = 52) and chronic (n = 60) hepatitis C treated with pegylated interferon-alpha. Two hundred ten HCV monoinfected, 197 HIV monoinfected, and 100 healthy individuals were studied as controls. Patients were classified into high and low producers according to IL-6 genotypes. Rates of sustained virological responses (SVRs) were compared between the IL-6 genotypes. Signal transducer and activator of transcription three phosphorylation was analyzed by Western blot in HCV core-transfected human hepatoma cell line (HUH7) cells. Distribution of IL-6 genotypes did not differ significantly between the study groups. SVR was achieved in 63% of HIV/HCV coinfected patients. Carriers of the IL-6 high producer (HP) genotype had significantly higher SVR rates than patients with an IL-6 low producer genotype (70.1% versus 52%; P < 0.002). This effect was seen in both HIV-positive patients with acute (74% versus 33%; P < 0.05) and chronic (66% versus 33%; P < 0.05) hepatitis C. Multivariate analysis confirmed IL-6 HP carriage as an independent positive predictor for SVR (Odd's ratio 6.1; P = 0.004). This effect corresponds to the in vitro observation that in HCV core-transfected HUH7 cells, IL-6 overcomes the HCV core-mediated inhibition of STAT3 activation. CONCLUSION: Response rates to HCV-specific treatment are higher in HCV/HIV-positive patients carrying the IL-6 HP genotype, which might be because of IL-6 mediated STAT3 activation.