Diet of two syntopic species of Crenuchidae (Ostariophysi: Characiformes) in an Amazonian rocky stream

Abstract This study assessed the diet of two poorly known syntopic fish species of the family Crenuchidae, Characidium aff. declivirostre and Leptocharacidium omospilus, in a Presidente Figueiredo´ rocky stream, Amazonas, Brazil. The stomach contents were analyzed and their Frequency of Occurrence (FO %) and Relative Volume (Vol %) were combined in a Feeding Index (IAi). We examined 20 individuals of C. aff. declivirostre and 23 of L. omospilus. The Morisita-Horn Index was used to estimate the overlap between the diets of these species. Immature insects were the most valuable items consumed by both fish species. The diet of C. aff. declivirostre was mainly composed of larvae and pupae of Chironomidae, while L. omospilus predominantly consumed larvae of Hydroptilidae, Hydropyschidae and Pyralidae. Thus, both species were classified as autochthonous insectivorous. Characidium aff. declivirostre was considered a more specialized species, probably reflecting lower feeding plasticity or the use of more restricted microhabitats compared to L. omospilus. When the food items were analyzed at the family taxonomic level, the diet overlap between these species was considered moderate (Morisita-Horn Index = 0.4). However, a more thorough analysis, at the genus level, indicates a very low diet overlap. Therefore, we conclude that the feeding segregation between C. aff. declivirostre and L. omospilus may favor their co-existence, despite their high phylogenetic closeness

Fibrosis assessment using FibroMeter combined to first generation tests in hepatitis C

AIM: To evaluate the performance of FibroMeter combined to the first generation tests aspartate aminotransferase-to-platelet ratio index (APRI) or Forns index to assess significant fibrosis in chronic hepatitis C (CHC). METHODS: First generation tests APRI or Forns were initially applied in a derivation population from Rio de Janeiro in Brazil considering cut-offs previously reported in the literature to evaluate significant fibrosis. FibroMeter was sequentially applied to unclassified cases from APRI or Forns. Accuracy of non-invasive combination of tests, APRI plus FibroMeter and Forns plus FibroMeter was evaluated in the Brazilian derivation population. APRI plus FibroMeter combination was validated in a population of CHC patients from Angers in France. All patients were submitted to liver biopsy staged according to METAVIR score by experienced hepatopathologists. Significant fibrosis was considered as METAVIR F ≥ 2. The fibrosis stage classification was used as the reference for accuracy evaluation of non-invasive combination of tests. Blood samples for the calculation of serum tests were collected on the same day of biopsy procedure or within a maximum 3 mo interval and stored at -70 °C. RESULTS: Seven hundred and sixty CHC patients were included (222 in the derivation population and 538 in the validation group). In the derivation population, the FibroMeter AUROC was similar to APRI AUROC (0.855 0.815, = 0.06) but higher than Forns AUROC (0.769, < 0.001). The best FibroMeter cut-off to discriminate significant fibrosis was 0.61 (80% diagnostic accuracy; 75% in the validation population, = 0.134). The sequential combination of APRI or Forns with FibroMeter in derivation population presented similar performance compared to FibroMeter used alone (79% 78% 80%, respectively, = 0.791). Unclassified cases of significant fibrosis after applying APRI and Forns corresponded to 49% and 54%, respectively, of the total sample. However, the combination of APRI or Forns with FibroMeter allowed 73% and 77%, respectively, of these unclassified cases to be correctly evaluated. Moreover, this combination resulted in a reduction of FibroMeter requirement in approximately 50% of the entire sample. The stepwise combination of APRI and FibroMeter applied to the validation population correctly identified 74% of patients with severe fibrosis (F ≥ 3). CONCLUSION: The stepwise combination of APRI or Forns with FibroMeter may represent an accurate lower cost alternative when evaluating significant fibrosis, with no need for liver biopsy

Effect of organic tomato (Lycopersicon esculentum) extract on the genotoxicity of doxorubicin in the Drosophila wing spot test

The consumption of organic tomatoes (ORTs) reduces the risk of harmful effects to humans and the environment caused by exposure to toxic agrochemicals. In this study, we used the somatic mutation and recombination test (SMART) of wing spots in Drosophila melanogaster to evaluate the genotoxicity of ORT and the effect of cotreatment with ORT on the genotoxicity of Doxorubicin® (DXR, a cancer chemotherapeutic agent) that is mediated by free radical formation. Standard (ST) cross larvae were treated chronically with solutions containing 25%, 50% or 100% of an aqueous extract of ORT, in the absence and presence of DXR (0.125 mg/mL), and the number of mutant spots on the wings of emergent flies was counted. ORT alone was not genotoxic but enhanced the toxicity of DXR when administered concomitantly with DXR. The ORT-enhanced frequency of spots induced by DXR may have resulted from the interaction of ORT with the enzymatic systems that catalyze the metabolic detoxification of this drug