农林科学最新文献

The mitochondrial gene cytochrome c oxidase subunit 1 (cox1) has long been suspected to be ineffective for species identification when employed alone. Some Lucilia (=Phaenicia) cuprina Wiedemann have mtDNA haplotypes closely resembling those of Lucilia sericata Meigen (Diptera: Calliphoridae), indicating paraphyly of L. cuprina with respect to L. sericata. Therefore, we evaluated the nuclear 28S rRNA and the mitochondrial cox1 genes to distinguish between L. cuprina and L. sericata using new DNA data from Northwest Africa. The current study provides the first evidence that L. cuprina occurs in Northwest Africa. The cox1 and the 28S genes were sequenced, and phylogenetic trees were constructed using the maximum likelihood method with 1000 bootstrap replicates. Sequencing yielded around 675 bp for cox1 and 633 bp for 28S. All the sequences were accurately identified using the BLASTn and submitted to GenBank. The 28S analysis confirmed the two species' mutual monophyly. In contrast, the cox1 analysis showed that L. cuprina is divided into two distinct clades, paraphyletic with respect to L. sericata. The 28S sequences clustered together do not exhibit any geographical consistency. Despite the paraphyletic relationship between L. sericata and the two forms of L. cuprina, mtDNA appears to be useful in differentiating between these two species. However, L. cuprina subspecies, L. cuprina cuprina (Wiedemann) and L. cuprina dorsalis Robineau-Desvoidy cannot be differentiated using the 28S and cox1 genes, nor can their distinctions be assumed based on their geographic locations, especially in regions where they are found in coexistence.

Canine phaeochromocytomas (PCCs) are neuroendocrine tumours with malignant potential. Metastatic disease remains the sole definitive evidence of malignancy. Histopathological criteria to predict long-term survival have not been established in dogs. This study evaluated the reproducibility and prognostic value of histopathological parameters derived from human scoring systems, along with the Ki67 proliferation index (PI), in dogs after adrenalectomy for PCC. Tumour samples from 41 dogs were assessed by a veterinary pathologist and pathology resident. Of 10 histopathological parameters examined, only necrosis, tumour cell spindling, and extension into adipose tissue achieved sufficient inter- and intra-observer agreement (≥ 0.40) for inclusion in survival analyses, while Ki67 PI demonstrated excellent reproducibility (≥ 0.95). A composite histopathological score was generated by summing these three parameters and a dichotomised Ki67 PI (optimal cutoff 18%), as determined by ROC analysis. Among the 41 dogs, eight died within 2 weeks postoperatively, leaving 33 long-term survivors with four tumour-related events. Kaplan-Meier analysis showed significantly poorer survival (p < 0.001) in dogs with a high Ki67 PI (≥ 18%), whereas the composite score showed a borderline significant association with outcome in Cox regression (p = 0.056; hazard ratio 2.80). Overall, dogs surviving the immediate postoperative period demonstrated a favourable prognosis (mean overall survival of 2456 days). These findings suggest that, in this cohort with few tumour-related events, the dichotomised Ki67 PI alone may serve as a clinically applicable prognosticator for canine PCC. However, further research in larger populations is needed to determine whether a composite score adds prognostic value and guides postoperative management.

Canine lymphoma is a common haematopoietic neoplasm. Immunophenotype is a major prognostic factor and may influence treatment recommendations. This study assessed the diagnostic performance of the Sysmex XN-1000V white blood cell differential (WDF) scattergram to differentiate canine nodal large B-cell and T-cell lymphoma, using the percentage of highly fluorescent cells (%HFC) and visual WDF scattergram evaluation. A retrospective study was conducted on data from cases of cytologically diagnosed canine large cell lymphoma. Cases had concurrent lymph node aspirate cell suspensions in saline that were analysed using the Sysmex XN-1000V and multiparametric flow cytometry (FC) for lymphoma classification as B or T-cell. Large B-cell lymphomas (n = 86) showed significantly higher %HFC compared to large T-cell lymphomas (n = 17), with a median (IQR) of 50% (36-84) and 9.7% (3.9-19), respectively. The ROC analysis showed an AUC of 0.93, with an optimal cutoff of < 24.15 %HFC for identifying T-cell lymphoma, achieving 88.24% sensitivity, 87.21% specificity, 57.69% PPV and 97.40% NPV. The following data is expressed as 'overall-percentage-agreement (kappa value)'. Using the previous cutoff, the agreement between the %HFC classification and FC was 88.24% (κ = 0.76). Regarding the WDF scattergram evaluation, the intra- and inter-observer agreement were 86.27% (κ = 0.71) and 67.65% (κ = 0.55), respectively. Agreement between the WDF scattergram evaluation and FC was 77.45% (κ = 0.55), and improved to 90.63% (κ = 0.74) when just the confident cases were used. In conclusion, a preliminary assessment of the phenotype of canine nodal large cell lymphoma can be made using either the visual inspection of the WDF scattergram or the %HFC. This could serve as a cost-effective, fast screening tool while awaiting definitive flow cytometry results.

Stereotactic body radiation therapy (SBRT) has become a non-invasive alternative option for canine adrenal tumours with high surgical risks; however, its clinical benefits and risks are still to be fully understood. The goal of this multi-institutional retrospective study was to describe the clinical outcome and safety of SBRT for the treatment of 21 dogs with adrenal tumours. Ten were suspected pheochromocytomas, two adenocarcinomas, and the diagnosis was unknown in nine dogs. Vascular invasion was present in 81% of cases (17/21). Thirteen dogs received 3 fractions of 6 to 11 Gy, 7 received 5 fractions of 6 to 9 Gy, and 1 received 4 fractions of 6 Gy. For the 20 patients with follow-up imaging, 9 (43%) had partial response, 10 (47%) stable disease, and 1 (5%) progressive disease. Progression-free survival was 16.8 months (95% CI: 3.4-23), and overall survival time was 16.8 months (95% CI: 3.7-23.7). Twelve patients (57%) experienced acute adverse events (AEs); of those, seven were gastrointestinal grade ≥ III, including one grade V. Late AEs were suspected in seven dogs (33%), including gastrointestinal grade V in four of them. A total of five dogs (24%) died from radiation-related toxicities. Although SBRT seems to be effective against adrenal tumours, it was associated with a high morbidity and mortality rate, suggesting that re-evaluation of radiation therapy protocols is necessary for maintaining patient safety.

Aliarcobacter butzleri is a Campylobacter-like bacteria associated with watery diarrhea in humans and is infrequently reported in nonhuman primate (NHP) populations. While clinical and microscopic features in humans are indistinguishable from Campylobacter spp. infection, descriptions of A. butzleri-associated colitis in NHP are lacking. Here, we describe the clinical and pathological features of diarrhea and colitis associated with A. butzleri in rhesus macaques using a retrospective approach. Over a 3-year period, A. butzleri was isolated from 10 macaques with diarrhea. Five of the 10 were submitted for necropsy and had features of chronic enterocolitis, consistent with existing literature. However, 40% (2/5) of the cases were characterized by ulcerative colitis, which has not previously been described as a feature of A. butzleri colitis. A. butzleri should be considered a differential diagnosis in cases of diarrhea and enterocolitis in captive rhesus macaques.

Alimentary mycosis is seldom reported in sloths. Through a multi-institutional retrospective study, we described the histological features of fungal infections within the digestive tract of sloths of the Bradypus and Choloepus genera. In addition, panfungal polymerase chain reaction (PCR) targeting the ITS-2 gene was performed in all cases to determine a specific etiology. We retrieved 11 cases of alimentary mycosis in 3 sloth species: Bradypus variegatus (n = 1), Choloepus hoffmanni (n = 7), and Choloepus didactylus (n = 3). Eight were free-ranging, whereas 3 were held in captivity. Nine were females and 8 were juveniles (ranging from 2 weeks to 2 years old). In 64% of the cases, the lesions were gastric in the muscular portion of the prepyloric stomach. In the other animals, the lesions were located in the tongue and/or esophagus. Pustules, erosions, ulcers, and hyperkeratosis within the keratinoid layer with intralesional yeast, pseudohyphae, and hyphae characterized alimentary mycotic infections. Panfungal PCR identified Trichosporon asahii infection in 45% (5/11) of the cases, from gastric, esophageal, and lingual lesions, and Penicillium sp. and Wallemia mellicola in a gastric lesion in 1 case each. Candida sp. infection was not confirmed in any of the cases. Trichosporon asahii has overlapping histological features with Candida and poses a diagnostic challenge when conventional culture or molecular methods are unavailable. Trichosporonosis is a differential diagnosis in cases of fungal alimentary lesions in sloths. Predisposing factors for alimentary mycosis in sloths include age (younger animals), canine distemper virus co-infection, late pregnancy, and chronic antibiotic use.

Seven cutaneous mast cell tumors were identified in 6 geriatric California sea lions (Zalophus californianus). All tumors were within the dermis and grossly appeared as single, or in one case two, less than 1-cm-diameter, well-circumscribed, raised nodules. The majority (6/7) of the neoplasms occurred near mucocutaneous junctions (eyelid, lip, or anus). The mast cell tumors were composed of round cells arranged in sheets with poorly granulated cytoplasm or an absence of cytoplasmic granules in routine hematoxylin and eosin-stained sections. Cytology (n = 1) showed adequate staining of mast cell granules with Diff-Quik and Wright-Giemsa stains. Immunohistochemistry for cKIT revealed cytoplasmic to membranous immunoreactivity in all tumors. Giemsa staining for metachromatic granules was inconsistent. No local recurrence or metastasis has been observed in the 5 living individuals with follow-up periods ranging from 6 to 42 months. Given these findings, similar poorly granulated mast cell tumors in geriatric California sea lions are suspected to have biologically benign behavior.

The vacuole formation (VF) rat is an autosomal recessive myelin mutant characterized by generalized tremor, hypomyelination, and periaxonal VF of the central nervous system. We previously identified a nonsense mutation in the DOP1 leucine zipper-like protein A (Dop1a, also known as Dopey1) gene located on rat chromosome 8. In this study, we investigated the kinetics of oligodendrocyte progenitor cells (OPCs) and oligodendrocytes by assessing the expression patterns of transcription factors that are involved in oligodendrocyte development. The number of small, round oligodendrocytes lacking distinct cellular processes, immunolabeled with anti-adenomatous polyposis coli (APC, clone CC1) antibody, was increased in the spinal cords of the VF rats, suggesting a disrupted maturation of oligodendrocytes. In addition, the terminal differentiation and maturation of OPCs into myelinating mature oligodendrocytes may be impaired and compensatory myelination largely could fail in the VF rat. Our findings also demonstrated that the DOP1A protein is expressed in OPCs as well as mature oligodendrocytes. Finally, the intracellular trafficking of myelin basic protein (Mbp) mRNAs may be disrupted in oligodendrocytes of the VF rats. Our data suggested that DOP1A dysfunction causes impaired differentiation and maturation of oligodendrocyte-lineage cells, resulting in hypomyelination and an impaired compensatory myelination.

Urine irritant contact dermatitis is a clinically well-recognized but poorly documented condition in small animals. This study aims to systematically summarize the clinical and histopathological features of canine and feline urine scalding. Twelve cases, 10 dogs and 2 cats, were identified and included in a retrospective study of medical records and histology samples. All animals had histories of urinary incontinence with urinary problems (ectopic ureters, urolithiasis, urinary tract infection, sphincter mechanism incompetence, etc.) or a genital conformational issue with concurrent urine scalding. Gross lesions varied and included white papules/plaques, discrete nodules, and overt ulcers that localized to perigenital areas and/or involve the abdomen, inguinal areas, and proximal legs. The hallmark histopathological changes were locally extensive epithelial hyperplasia with marked spongiosis (intracellular edema) of the granular and spinous layers, diffuse parakeratosis, and variable degrees of erosion to ulceration with secondary bacterial infection and necrosis. This report summarizes the clinical and histopathological findings in urine scalding and highlights the importance of the clinical history, presentation, and lesion distribution to achieve the correct diagnosis. In the absence of a history or awareness by the pathologist of this unique histopathological pattern, urine scalding could easily be misdiagnosed.