Effect of Retreatment with Interferon Alone or Interferon plus Ribavirin on Hepatitis C Virus Quasispecies Diversification in Nonresponder Patients with Chronic Hepatitis C

Alpha interferon (IFN-alpha) treatment is effective on a long-term basis in only 15 to 25% of patients with chronic hepatitis C. The results of recent trials indicate that response rates can be significantly increased when IFN-alpha is given in combination with ribavirin. However, a large number of patients do not respond even to combination therapy. Nonresponsiveness to IFN is characterized by evolution of the hepatitis C virus (HCV) quasispecies. Little is known about the changes occurring within the HCV genomes when nonresponder patients are retreated with IFN or with IFN plus ribavirin. In the present study we have examined the genetic divergence of HCV quasispecies during unsuccessful retreatment with IFN or IFN plus ribavirin. Fifteen nonresponder patients with HCV-1 (4 patients with HCV-1a and 11 patients with HCV-1b) infection were studied while being retreated for 2 months (phase 1) with IFN-alpha (6 MU given three times a week), followed by IFN plus ribavirin or IFN alone for an additional 6 months (phase 2). HCV quasispecies diversification in the E2 hypervariable region-1 (HVR1) and in the putative NS5A IFN sensitivity determining region (ISDR) were analyzed for phase 1 and phase 2 by using the heteroduplex tracking assay and clonal frequency analysis techniques. A major finding of this study was the relatively rapid evolution of the HCV quasispecies observed in both treatment groups during the early phase 1 compared to the late phase 2 of treatment. The rate of quasispecies diversification in HVR1 was significantly higher during phase 1 versus phase 2 both in patients who received IFN plus ribavirin (P = 0.017) and in patients who received IFN alone (P = 0. 05). A trend toward higher rates of quasispecies evolution in the ISDR was also observed during phase 1 in both groups, although the results did not reach statistical significance. However, the NS5A quasispecies appeared to be rather homogeneous and stable in most nonresponder patients, suggesting the presence of a single well-fit major variant, resistant to antiviral treatment, in agreement with published data which have identified an IFN sensitivity determinant region within the NS5A. During the entire 8 months of retreatment, there was no difference in the rate of fixation of mutation between patients who received combination therapy and patients who were treated with IFN alone, suggesting that ribavirin had no major effects on the evolution of the HCV quasispecies after the initial 2 months of IFN therapy.     

Effect of Age, Body Weight and Multiple Mating on Copitarsia decolora (Lepidoptera: Noctuidae) Reproductive Potential and Longevity

Successful behavioral-based control methods rely on the accurate knowledge of the mating dynamics of the target insect. Age at first mating affects reproductive potential and the chance of multiple mating. The cabbage moth, Copitarsia decolora (Guenée) is an important pest of a number of commodities. We investigated combinations of age, body size and mating history to determine how these variables affect insect reproductive capacity. Fecundity and fertility decreased as the age of mating pairs increased, heavy and average sized females laid more eggs than light females. Female multiple mating did not enhance fecundity nor fertility potential. Furthermore, spermatophore size did not determine female re-mating behavior. However, female fecundity and fertility was related to the male mating history. Our results show that SIT is a valuable tool for controlling this pest.     

Cytokine Profiling in Immigrants with Clinical Malaria after Extended Periods of Interrupted Exposure to Plasmodium falciparum

Immunity to malaria is believed to wane with time in the absence of exposure to Plasmodium falciparum infection, but immunoepidemiological data on longevity of immunity remain controversial. We quantified serum cytokines and chemokines by suspension array technology as potential biomarkers for durability of immunity in immigrants with clinical malaria after years without parasite exposure. These were compared to serum/plasma profiles in naïve adults (travelers) and semi-immune adults under continuous exposure, with malaria, along with immigrant and traveler patients without malaria. Immigrants had higher levels of IL-2, IL-5 and IL-8 compared to semi-immune adults with malaria (P≤0.0200). Time since immigration correlated with increased IL-2 (rho=0.2738P=0.0495) and IFN-γ (rho=0.3044P=0.0282). However, immigrants did not show as high IFN-γ concentrations as travelers during a first malaria episode (P<0.0001). Immigrants and travelers with malaria had higher levels of IFN-γ, IL-6, and IL-10 (P<0.0100) than patients with other diseases, and IL-8 and IL-1β were elevated in immigrants with malaria (P<0.0500). Therefore, malaria patients had a characteristic strong pro-inflammatory/Th1 signature. Upon loss of exposure, control of pro-inflammatory responses and tolerance to P. falciparum appeared to be reduced. Understanding the mechanisms to maintain non-pathogenic effector responses is important to develop new malaria control strategies.     

Artificial endosperm of Cleopatra tangerine zygotic embryos: a model for somatic embryo encapsulation

Synthetic seed technology may be of value in breeding programs and allow the propagation of many elite genotype-derived plants in a short time. In this work, a range of artificial endosperm treatments of Cleopatra tangerine zygotic embryos were evaluated for suitability for encapsulation of somatic embryos. Different complexing ions in the form of alginate capsules, zeolite as an ion exchanger and the relationship between capsule-nutrient gel on germination of zygotic embryos, were evaluated. Artificial endosperm assays showed that abscisic acid (1 μM) and mannitol (0.25 M) delayed germination and conversion of zygotic embryos, whereas amino acid supplements (proline, glutamic acid and arginine) accelerated the conversion process. An artificial endosperm was used to encapsulate somatic and zygotic embryos. After encapsulation, zygotic embryos germinated after four days of culture while somatic embryos germinated asynchronously after 20 days. Somatic embryo-derived plantlets showed greater vigour than zygotic embryo-derived plantlets. Results showed that this artificial endosperm is adequate for Cleopatra tangerine somatic embryo germination and conversion into plants. This revised version was published online in June 2006 with corrections to the Cover Date.     

Results of the Implementation of a Pilot Model for the Bidirectional Screening and Joint Management of Patients with Pulmonary Tuberculosis and Diabetes Mellitus in Mexico

Background

Recently, the World Health Organisation and the International Union Against Tuberculosis and Lung Disease published a Collaborative Framework for the Care and Control of Tuberculosis (TB) and Diabetes (DM) (CFTB/DM) proposing bidirectional screening and joint management.

Objective

To evaluate the feasibility and effectiveness of the CFTB/DM in Mexico. Design. Prospective observational cohort. Setting. 15 primary care units in 5 states in Mexico. Participants: Patients aged ≥20 years diagnosed with DM or pulmonary TB who sought care at participating clinics. Intervention: The WHO/Union CFTB/DM was adapted and implemented according to official Mexican guidelines. We recruited participants from July 2012 to April 2013 and followed up until March 2014. Bidirectional screening was performed. Patients diagnosed with TB and DM were invited to receive TB treatment under joint management. Main outcome measures. Diagnoses of TB among DM, of DM among TB, and treatment outcomes among patients with DM and TB.

Results

Of 783 DM patients, 11 (1.4%) were unaware of their TB. Of 361 TB patients, 16 (4.4%) were unaware of their DM. 95 TB/DM patients accepted to be treated under joint management, of whom 85 (89.5%) successfully completed treatment. Multiple linear regression analysis with change in HbA1c and random capillary glucose as dependent variables revealed significant decrease with time (regression coefficients (β)  = −0.660, (95% confidence interval (CI), −0.96 to −0.35); and β = −1.889 (95% CI, −2.77 to −1.01, respectively)) adjusting by sex, age and having been treated for a previous TB episode. Patients treated under joint management were more likely to experience treatment success than patients treated under routine DM and TB programs as compared to historical (adjusted OR (aOR), 2.8, 95%CI 1.28–6.13) and same period (aOR 2.37, 95% CI 1.13–4.96) comparison groups.

Conclusions

Joint management of TB and DM is feasible and appears to improve clinical outcomes.     

Ploidy level and genome size of locally adapted populations of <Emphasis Type="Italic">Silene ciliata</Emphasis> across an altitudinal gradient

Silene ciliata Poiret is a small perennial that presents several ploidy levels and inhabits the mountain ranges of the European Mediterranean basin. Recent studies have shown evidence of local adaptation in populations located across an altitudinal gradient in Sierra de Guadarrama (Central Spain) at the species’ southernmost distribution limit. In this study, we assessed whether the existence of local adaptation in these populations was related to differences in karyological features (ploidy level or chromosome number modification) or in nuclear DNA amount. Optical microscope (phase contrast and epifluorescence after DAPI staining) and flow cytometry were used to estimate the ploidy level and genome size of several family lines in three populations across the altitude gradient. With a sampling three times higher than usual in genome size assessments, all individuals showed a constant diploid set (2n = 24), so that polyploidy or other chromosome number modifications were discarded. The small genome size found (mean ± SD; 2C = 1.76 ± 0.06 pg) was within the range of those found in other Silene species. Significant differences in genome size were found when the three populations of S. ciliata were compared. The largest genome size found at the intermediate population may be associated to lower environmental stress at the mid elevation, in line with the recent studies in this area.     

Soil Effects on Forest Structure and Diversity in a Moist and a Dry Tropical Forest

Soil characteristics are important drivers of variation in wet tropical forest structure and diversity, but few studies have evaluated these relationships in drier forest types. Using tree and soil data from 48 and 32 1 ha plots, respectively, in a Bolivian moist and dry forest, we asked how soil conditions affect forest structure and diversity within each of the two forest types. After correcting for spatial effects, soil‐vegetation relationships differed between the dry and the moist forest, being strongest in the dry forest. Furthermore, we hypothesized that soil nutrients would play a more important role in the moist forest than in the dry forest because vegetation in the moist forest is less constrained by water availability and thus can show its full potential response to soil fertility. However, contrary to our expectations, we found that soil fertility explained a larger number of forest variables in the dry forest (50 percent) than in the moist forest (17 percent). Shannon diversity declined with soil fertility at both sites, probably because the most dominant, shade‐tolerant species strongly increased in abundance as soil fertility increased.