Non-invasive biomagnetic assessment of gastrointestinal motility in a loperamide-induced constipation model

Constipation is a disorder of the gastrointestinal (GI) and some of the main etiological mechanisms are directly related to changes in GI physiology. The capacity to carry out paired assessments and measure GI parameters under the influence of constipation is a relevant point in selecting a suitable methodology. We aimed to perform a non-invasive investigation of gastrointestinal motility in constipated rats using the alternating current biosusceptometry system (ACB). The animals were split into two groups: the pre-induction stage (CONTROL) and post-induction loperamide stage (LOP). We assessed GI motility parameters using the ACB system. Colon morphometric and immunohistochemical analyses were performed for biomarkers (C-kit) for interstitial cells of Cajal (ICC). Our results showed a significant increase in gastrointestinal transit in the LOP group in addition to a reduction in the dominant frequency of gastric contraction and an arrhythmic profile. A change in colonic contractility profiles was observed, indicating colonic dysmotility in the LOP group. We found a reduction in the number of biomarkers for intestinal cells of Cajal (ICC) in the LOP group. The ACB system can evaluate transit irregularities and their degrees of severity, while also supporting research into novel, safer, and more efficient treatments for constipation.

Genomic characterization of Canine circovirus detected in a dog with intermittent hemorrhagic gastroenteritis in Brazil / Caracterização genômica do Canine circovirus detectado em um cão com gastroenterite hemorrágica intermitente no Brasil

ABSTRACT: Because Canine circovirus (CanineCV) is a new species of the genus Circovirus, several issues related to its epidemiology, pathogenesis and clinical disease remain unknown. Thus, this study aimed to perform the characterization of the first complete genome sequence of CanineCV detected in a dog with diarrhea in Brazil. A stool sample was collected of a ten-month-old female German Shepherd dog which had signs of intermittent hemorrhagic gastroenteritis, vomiting, and a history of eating raw pork. The complete CanineCV genome was sequenced by Next-Generation Sequencing. The sequence had 2,063 nucleotides, showed a typical genomic organization for circovirus, and was grouped with strain 214 described in the United States by phylogenetic analysis. One amino acid change was found in the replicase protein, and because of that it was considered unique to CanineCV. Therefore, the characterization of the complete genome of Brazilian CanineCV can be used in future studies of molecular epidemiology, pathogenesis and development of diagnostic tools for the prevention and control of this disease.

RESUMO: Como o Canine circovirus (CanineCV) é uma nova espécie do Gênero Circovirus, várias questões relacionadas com a sua epidemiologia, patogenia e doença clínica permanecem desconhecidas. Assim, este estudo objetivou realizar a caracterização da primeira sequência do genoma completo do CanineCV detectado em um cão com diarreia, no Brasil. Uma amostra de fezes foi coletada de um cão da raça Pastor Alemão, fêmea, 10 meses de idade, o qual tinha sinais de gastroenterite hemorrágica intermitente, vômito e uma história de ingestão de carne crua de porco. O genoma completo do CanineCV foi sequenciado pelo Sequenciamento de Nova Geração. A sequência tinha 2.063 nucleotídeos, apresentou uma organização genômica típica para um circovírus e foi agrupado com a cepa 214, descrita nos Estados Unidos pela análise filogenética. Uma mudança de aminoácido foi encontrada na proteína de replicação e por causa disso ela foi considerada única para o CanineCV. Portanto, a caracterização do genoma completo do CanineCV brasileiro pode ser utilizada em futuros estudos de epidemiologia molecular, patogenia e no desenvolvimento de ferramentas de diagnóstico para prevenção e controle desta doença.