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Chediak–Higashi syndrome (CHS) is a rare and potentially fatal autosomal recessive disease characterized by frequent bacterial infections, bleeding tendency, oculocutaneous albinism, photosensitivity and progressive neurologic dysfunction. Owing to the rarity of this condition, the objective of this study was to describe patients with CHS.

Inland water sediments receive large quantities of terrestrial organic matter and are globally important sites for organic carbon preservation. Sediment organic matter mineralization is positively related to temperature across a wide range of high-latitude ecosystems, but the situation in the tropics remains unclear. Here we assessed temperature effects on the biological production of CO2and CH4in anaerobic sediments of tropical lakes in the Amazon and boreal lakes in Sweden. On the basis of conservative regional warming projections until 2100 (ref. ), we estimate that sediment CO2and CH4production will increase 9–61% above present rates. Combining the CO2and CH4as CO2equivalents (CO2eq; ref. ), the predicted increase is 2.4–4.5 times higher in tropical than boreal sediments. Although the estimated lake area in low latitudes is 3.2 times smaller than that of the boreal zone, we estimate that the increase in gas production from tropical lake sediments would be on average 2.4 times higher for CO2and 2.8 times higher for CH4. The exponential temperature response of organic matter mineralization, coupled with higher increases in the proportion of CH4relative to CO2on warming, suggests that the production of greenhouse gases in tropical sediments will increase substantially. This represents a potential large-scale positive feedback to climate change.

AbstractHepatitis C virus (HCV) exhibits a dramatic genetic variability and several mechanisms of immunological response are unable to control hepatic and extrahepatic replication. Genotype 1 b is associated with more severe clinical manifestations and is less responsive to interferon. In addition, we have reported an increase of HCV RNA viral load after renal transplantation. Anti‐thymocyte globulin (ATG) is supposed to increase viral replication and liver dysfunction in chronically infected renal graft recipients. We evaluated the genotype profile in HCV + patients of our Renal Transplant Unit and studied the effects of ATG, as part of the induction of immunosuppression, on viral load and liver enzymes abnormalities. From 726 renal graft recipients, 104 patients, with a mean follow up of 3.9 ± 2.9 years, were anti‐HCV + by ELISA II. HCV RNA was measured by quantitative PCR. We correlated the viral load and biochemical liver parameters with genotype, exposure to ATG as induction therapy, early acute rejection episode and the duration of infection. Of the 81 patients tested, 72 % were viraemic and genotype 1 b was the predominant viral strain (66 %). The majority of these patients (65 %) were coinfected by two or more strains. There was no correlation between HCV RNA blood levels and liver enzymes. We did not find higher viral load with genotype 1 b infection (68 ± 88 mEq/ml vs 75.8 ± 123 mEq/ml in the others) nor with ATG induction therapy (43.5 ± 71.3 mEq/ml vs 64.1 ± 110.5 mEq/ml). Early acute rejection and longer follow up were not associated with higher levels of HCV RNA. The biochemical liver profile showed no relationship with the variables studied. We concluded that genotype 1 b is the predominant strain in our HCV + population and there is a great prevalence of coinfection with several genotypes. Our results did not confirm a deleterious effect of the use of ATG as induction therapy in these HCV‐infected patients. Prospective randomised studies with liver biopsy evaluation are needed to answer more fully the remaining questions about the best immunosuppressive therapy in renal graft recipients with chronic HCV infection.