A Mesoamerican origin of cherimoya (Annona cherimola Mill.): Implications for the conservation of plant genetic resources.

Knowledge on the structure and distribution of genetic diversity is a key aspect to plan and execute an efficient conservation and utilization of the genetic resources of any crop as well as for determining historical demographic inferences. In this work, a large data set of 1,765 accessions of cherimoya (Annona cherimola Mill, Annonaceae), an underutilized fruit tree crop native to the Neotropics and used as a food source by pre-Columbian cultures, was collected from six different countries across the American continent and amplified with nine highly informative microsatellite markers. The structure analyses, fine representation of the genetic diversity and an ABC approach suggest a Mesoamerican origin of the crop, contrary to previous reports, with clear implications for the dispersion of plant germplasm between Central and South America in pre-Columbian times. These results together with the potential distribution of the species in a climatic change context using two different climate models provide new insights for the history and conservation of extant genetic resources of cherimoya that can be applied to other currently underutilized woody perennial crops.

The safety of pegylated interferon alpha-2b in the treatment of chronic hepatitis B: predictive factors for dose reduction and treatment discontinuation.

BACKGROUND: Treatment with interferon-alpha has been shown to be effective in one-third of hepatitis B e antigen-positive chronic hepatitis B patients, but is clinically associated with relevant adverse events. AIM: To investigate the safety of pegylated interferon alpha-2b in 300 hepatitis B e antigen-positive patients with compensated liver disease. METHODS: Patients were treated with pegylated interferon alpha-2b for 52 weeks combined with either lamivudine 100 mg/day or placebo. Pegylated interferon alpha-2b was administered for 100 microg once a week for 32 weeks; thereafter, the dose was reduced to 50 microg once a week. Adverse events and their effect on study medication were reported at monthly visits in a standardized way. RESULTS: The most frequently reported side-effects were flu-like syndrome (68%), headache (40%), fatigue (39%), myalgia (29%) and local reaction at the injection site (29%). These symptoms typically occurred within the first month of therapy and subsided during the course of therapy. Neutropenia and thrombocytopenia induced by pegylated interferon alpha-2b increased the risk of infections and bleeding complications, but these complications were rare and mild. The frequency of all side-effects was not different between patients treated with pegylated interferon alpha-2b combined with lamivudine or placebo. In 69 (22%) patients the dose of pegylated interferon alpha-2b was reduced prematurely. Of these dose reductions, 36 (52%) were because of neutropenia. Therapy was discontinued in 28 (8%) patients. The most frequent reasons for early discontinuation were psychiatric side-effects (depression, psychosis) and flu-like symptoms. Multivariate Cox regression analysis showed that low neutrophil count at baseline and cirrhosis were independent predictors of dose reduction or therapy discontinuation. CONCLUSION: We conclude that in patients with chronic hepatitis B and compensated liver disease prolonged pegylated interferon alpha-2b therapy is safe, and that pre-existent cirrhosis and neutropenia are the most important predictors of dose reduction or early treatment discontinuation.

Flares in chronic hepatitis B patients induced by the host or the virus? Relation to treatment response during Peg-interferon {alpha}-2b therapy.

BACKGROUND AND AIMS: Flares are a well known phenomenon during antiviral treatment for chronic hepatitis B. Little is known about the effect of flares on response. We investigated the timing and characteristics of flares, in relation to treatment response (hepatitis B e antigen loss). PATIENTS: A total of 266 patients, participating in a global randomised controlled study, were assigned to 52 weeks of 100 mug pegylated (Peg)-interferon alpha-2b weekly, combined with either daily lamivudine 100 mg or placebo. RESULTS: Sixty seven patients (25%) exhibited 75 flares, with 38 (51%) flares in the combination therapy and 37 (49%) in the monotherapy groups. Overall, 30% of patients with and 38% of patients without a flare responded to therapy (p = 0.25). In 24 patients (36%) the flare was followed by a decrease in hepatitis B virus (HBV) DNA (host induced flare). In 25 (38%) patients the flare was preceded by an increase in HBV DNA (virus induced flare). In 17 (26%) patients the flare did not meet one of these criteria (indeterminate flare). Of patients with host induced flare, 58% responded whereas only 20% of patients with virus induced flares responded (p = 0.008). Hepatitis B surface antigen loss (n = 8) was exclusively seen in patients experiencing a host induced flare. Multivariate logistic analysis showed that host induced flares was an independent predictor of response (p = 0.043). CONCLUSION: Flares are not more common in responders than in non-responders to Peg-interferon alpha-2b therapy. Virus induced flares, which occur after an increase in HBV DNA level, and most probably are indicative for increased expression of viral antigens, did not lead to treatment response. In contrast, host induced flares which were followed by a HBV DNA decrease were highly associated with treatment response.

Lamivudine treatment during pregnancy to prevent perinatal transmission of hepatitis B virus infection.

Vertical transmission of hepatitis B virus (HBV) can occur occasionally despite vaccination of the child. This vaccination breakthrough has been associated with high maternal viraemia. We treated eight highly viraemic (HBV-DNA >/= 1.2 x 10(9) geq/mL) mothers with 150 mg of lamivudine daily during the last month of pregnancy. HBV-DNA, hepatitis B surface antigen (HBsAg), anti-HBs and anti-HBc of their offspring were measured at birth and at 3, 6 and 12 months, respectively. Twenty-four children, born to untreated HBsAg-positive mothers with HBV-DNA levels >/=1.2 x 10(9) geq/mL served as historical controls. All children received passive-active immunization at birth and were followed-up for 12 months. In the lamivudine group one of the eight children (12.5%) was still HBsAg and HBV-DNA positive at the age of 12 months. All other children seroconverted to anti-HBs and maintained seroprotection. In three children, HBV-DNA was temporarily detected by polymerase chain reaction. In the untreated historical control group, perinatal transmission occurred in seven of 25 children (28%). In highly viraemic HBsAg-positive mothers, reduction of viraemia by lamivudine therapy in the last month of pregnancy may be an effective and safe measure to reduce the risk of child vaccination breakthrough. This approach should be evaluated in a large controlled trial.