Micro-computed tomographic assessment of dentinal microcrack formation in straight and curved root canals in extracted teeth prepared with hand, rotary and reciprocating instruments.

AIM: To compare microcrack formation in roots of extracted teeth after the shaping of straight and curved root canals with hand, rotary and reciprocating files using micro-computed tomographic (micro-CT) analysis. METHODOLOGY: Thirty straight mandibular incisors and 30 severely curved mesial roots of mandibular molars were randomly divided into 6 experimental groups (n = 10) according to the systems used for the root canal preparation and the root canal curvature: ProTaper Universal for Hand Use (Dentsply Sirona, Ballaigues, Switzerland), HyFlex EDM (Coltene-Whaledent, Altstätten, Switzerland) and Reciproc Blue (VDW, Munich, Germany) files used in mandibular incisors (straight canals) and mesial roots of mandibular molars (curved canals). The roots were imaged with micro-CT scanning at an isotropic resolution of 14 µm before and after root canal preparation, and the cross-sectional images generated were assessed to detect microcracks. RESULTS: All dentinal defects identified after root canal preparation were already present before instrumentation, and no new microcracks were detected. Dentinal microcracks were present in 19% (ProTaper Universal for Hand Use), 11% (Hyflex EDM) and 23% (Reciproc Blue) of the cross-sections when the instrumentation was performed in mandibular incisors. Instrumentation of mandibular molars revealed microcracks in 15% (ProTaper Universal for Hand Use), 16% (Hyflex EDM) and 17% (Reciproc Blue) of the cross-sections. CONCLUSIONS: Preparation of straight and curved root canals with ProTaper Universal for Hand Use, HyFlex EDM and Reciproc Blue systems did not produce microcracks in extracted teeth when evaluated with micro-CT.

Primary gastric rupture in 20 horses from Midwestern Brazil: case report / Ruptura gástrica primária em 20 equinos no Centro-Oeste do Brasil: relato de caso

An 11-year (2007-2018) survey of epidemiological, clinical and pathological findings of horses with primary gastric rupture (PGR) was conducted. Twenty horses presented PGR, nine (45%) horses were clinically evaluated, eleven (55%) were sent dead, and all animals were necropsied. PGR contributed to a prevalence of 0.31% (9/2,868) of all equid attendances, 1.83% (9/491) of colic cases, and 4.1% (20/487) of all equid necropsies. Highly fermentable feed (n=7), gastric impaction (n=4), and perforating gastric ulcer (n=1) were the main causes of PGR; whilst eight horses presented idiopathic gastric rupture. Clinically evaluated horses were tachycardic, tachypneic, febrile, dehydrated, with increased abdominal tension, abnormal mucous membranes and reduced to absent intestinal borborygmi. Improper dietary management, such as the ingestion of low-quality roughage and highly fermentable feedstuffs were detected as the main factors associated with PGR in Midwestern Brazil. It is important to raise awareness in horse owners about proper feed management to minimize PGR.(AU)

Foi realizado um levantamento de 11 anos (2007-2018) dos achados epidemiológicos, clínicos e patológicos de equinos com ruptura gástrica primária (RGP). Vinte equinos apresentaram RGP, dos quais nove (45%) foram avaliados clinicamente e 11 (55%) foram enviados mortos, sendo todos os animais necropsiados. A RGP contribuiu com prevalência de 0,31% de todos os atendimentos de equídeos (9/2.868), 1,83% (9/491) dos casos de cólica, e 4,1% (20/487) das necropsias em equídeos. Alimentos altamente fermentáveis (n=7), compactação gástrica (n=4) e perfuração de úlcera gástrica (n=1) foram as principais causas de RGP, enquanto oito equinos tiveram ruptura gástrica idiopática. Os equinos avaliados clinicamente apresentaram-se taquicárdicos, taquipneicos, febris, desidratados, com mucosas anormais, aumento da tensão abdominal e motilidade intestinal reduzida. O manejo inadequado da dieta, como a ingestão de forragens de baixa qualidade e alimentos altamente fermentáveis, foi o principal fator de risco associado à RGP no Centro-Oeste do Brasil. É importante aumentar a conscientização dos proprietários de equinos sobre o manejo alimentar adequado para minimizar a RGP.(AU)

Impairment of Interleukin-17A Expression in Canine Visceral Leishmaniosis is Correlated with Reduced Interferon-γ and Inducible Nitric Oxide Synthase Expression.

Dogs are the primary urban reservoir of Leishmania infantum and play a crucial role in the transmission of this parasite to man via sandflies. The spleen and liver are the main target organs of L. infantum infection, but few studies have evaluated the immune response to this infection in the canine liver. To identify the immunological mediators involved in resistance and/or susceptibility to canine visceral leishmaniosis (CVL), we selected 21 dogs naturally infected by L. infantum and classified as asymptomatic or symptomatic. Immunological parameters were analysed and correlations with clinical signs were determined. Symptomatic dogs showed higher numbers of parasites and less leucocyte infiltration in the liver compared with asymptomatic dogs. The progression of this disease was characterized not only by the down regulation of T helper (Th) 1-related cytokines, such as interferon (IFN)-γ and tumour necrosis factor (TNF)-α, but also by the down regulation of genes encoding interleukin (IL)-17A, inducible nitric oxide synthase (iNOS) and IL-10 in the spleen and liver in symptomatic dogs compared with asymptomatic dogs. Importantly, IL-17A gene transcription level was positively correlated with mRNA expression for iNOS and IFN-γ. Th1- and Th17-related cytokines therefore appear to play a role in restricting parasite growth via iNOS activation and decrease susceptibility of dogs to CVL.

Genetic analyses of Trypanosoma cruzi isolates from naturally infected triatomines and humans in northeastern Brazil.

Trypanosoma cruzi genetic diversity was investigated in 25 isolates (vectors and humans) from the semiarid zone of the State of Rio Grande do Norte, Brazil. Molecular markers (3' region of the 24Salpha rRNA; mitochondrial cytochrome oxidase subunit 2 (COII) gene; spliced leader intergenic region (SL-IR) gene; allelic size microsatellite polymorphism) identified 56% TcIII (100% Panstrongyluslutzi; 50% Triatomabrasiliensis); 40% TcII (91.7% humans; 50% T. brasiliensis) and 4% TcI (human). Microsatellite analysis revealed monoclonal and heterozygous patterns on one or more microsatellite loci in 64% of T. cruzi isolates (92.3% triatomines; 33.3% humans) and 36% putative polyclonal populations (66.7% humans; 7.7% triatomines) by loci SCLE10, SCLE11, TcTAT20, TcAAAT6, all belonging to TcII. Identical T. cruzi polyclonal profiles (88.9%) were detected, mostly from humans. The adaptative natural plasticity of TcII and TcIII and their potential for maintaining human infection in T. brasiliensis were confirmed. Intraspecific and phylogenetic T. cruzi diversity in the sylvatic and domestic transmission cycles in this specific region will provide exclusive control strategies.

Type 2 dens invaginatus in a maxillary lateral incisor: a case report of a conventional endodontic treatment.

Dens invaginatus is a rare malformation of the teeth resulting from the invagination of the tooth crown before biological mineralization occurs. In most cases, the thin or incomplete enamel lining of the invagination cannot prevent the entry of bacteria into the pulp, which leads to pulp necrosis with an eventual periapical inflammatory response. The treatment options include preventive sealing or filling of the invagination, root canal treatment, endodontic apical surgery and extraction. The root canal treatment of such teeth is often complicated because of their anatomical complexity. This case describes a successful non-surgical endodontic treatment of a maxillary lateral incisor with type 2 dens invaginatus with a large periradicular lesion. At follow-up examinations after 6 and 12-months, the tooth was asymptomatic and the healed lesion was evident radiographically