ABSTRACT
Background and Aim: Extensive cattle rearing is a major source of economy for the inhabitants of the Amazon region of Peru. Milk and meat production is generally affected by the prevalence of various parasites, including hepatic and gastrointestinal parasites, as these products provide ideal conditions for parasitic growth. This poses a serious public health threat. This study aimed to estimate the prevalence, coinfection, and risk factors associated with the liver fluke (Fasciola hepatica) and other gastrointestinal parasites in cattle from the Amazon region of Peru. Materials and Methods: Fecal samples obtained from 1450 bovine specimens were analyzed using flotation and sedimentation methods to identify parasites, including Eimeria spp., strongyle-type eggs (STEs), and F. hepatica. We collected information about the specimens, including age, sex, origin, breed, category, frequency of deworming, farm size, herd size, water sources, and rearing system by conducting simple inspections and interviewing owners. The data obtained were statistically evaluated using the Chi-square test (p < 0.05) to determine the association between the qualitative variables. We also calculated the odds ratio at a 95% confidence interval to identify the risk factors. Results: We observed that F. hepatica, Eimeria spp., and STEs were 45.6%, 39.8%, and 35.3% prevalent, respectively. We found risk factors related to distomatosis in the animals from Huambo, where the drinking water sources are mainly streams, ditches, and rivers, while the specimens from Valle Chico were predisposed to coccidiosis. Further, the risk factors related to the presence of STEs in feces were age (61-90 months), origin (Valle Chico), herd size (<50 animals), and type of extensive rearing. Furthermore, significant coinfection was observed between Eimeria spp. and STEs. Conclusion: The high percentages of parasites in cattle observed were related to epidemiological factors, such as the origin of the sample, water sources, age, herd size, and extensive breeding. Similarly, the presence of STEs was a risk factor for contracting coccidiosis. Our future goals include investigating these parasites using a larger sample size and identifying more risk factors using more sensitive and specific diagnostic tests.
ABSTRACT
BACKGROUND/AIMS: Lung carcinoids are uncommon neuroendocrine tumours. Molecular features of lung carcinoids have been poorly defined. microRNAs (miRNAs) are potent gene expression regulators with important roles in cancer development and progression. However, little is known on the role of miRNAs in the pathogenesis of lung carcinoids. Our goals were to identify commonly deregulated miRNAs in a rare case of lung carcinoid of typical histology with metastasis, as well as map miRNA target genes in pathways potentially associated with disease development and progression. METHODS: miRNA expression profiles were assessed using the TaqMan Low Density Arrays, which is a platform including 384 miRNAs. miRNA profiles were generated in the tumor and its corresponding lymph node metastasis, compared to reference normal lung tissues. Furthermore, miRNA expression was validated in a separate, publicly available external dataset (n=19 typical lung carcinoids; 2/19 were metastatic tumors, compared to six normal lung tissues, GSE77380). Following this analysis, computational tools were applied for data interpretation. miRTarBase was used to determine miRNA-target genes, followed by ToppGene Suite analysis to identify pathways and biological functions. In addition, the expression of genes targeted by miRNAs was validated in a second, separate external dataset (n=13 tumour samples, GSE35679). GEO2R data analysis tool was used in both validation analyses (miRNAs and genes). RESULTS: We identified 15 commonly significantly downregulated miRNAs (fold change, FC≥2 and p<0.05) in the tumour and its paired metastasis, with further decreasing levels in the metastatic lesion. Downregulation of miR-126-3p and miR-146b-5p was validated in the external dataset GSE77380. In addition, SOX2 and TCF4 genes, targeted by miR-126-3p, were consistently overexpressed in a subset of six typical lung carcinoids from the external dataset GSE35679. Pathways analysis showed that miRNAs miR-126-3p and miR-146b-5p target genes with a role in the regulation of adaptive immune response. CONCLUSION: Our results contribute to the identification of miRNA expression changes in a typical lung carcinoid and its corresponding lymph node metastasis. Down-regulated levels of miR-126-3p and miR-146b-5p and target gene over-expression could play a role in the progression of this case of primary typical lung carcinoid to regional metastasis. Identified miRNAs and target genes are potential candidates for validation in a larger number of cases.