农林科学最新文献

Avian leukosis virus subgroup J (ALV-J) is an alpharetrovirus that infects chickens, causing immunosuppression and a decrease in production performance, leading to substantial economic losses in the poultry industry. ALV-J is also well-known for its oncogenic properties, inducing tumours such as myelomas and haemangiomas in infected chickens. TRIM45 has been identified as a potential tumour suppressor; however, the relationship between TRIM45 expression and ALV-J infection remains to be elucidated. This study aimed to dissect the molecular characteristics of the chicken TRIM45 gene and its modulation during ALV-J infection, as well as its influence on viral replication. We found that the chicken TRIM45 RING domain is significantly different from that of humans and other mammals. TRIM45 is expressed in all chicken tissues, with the highest levels in the heart. Subcellular localization studies indicated a cytoplasmic distribution of TRIM45, forming aggregates within cells. Our findings demonstrate that ALV-J infection significantly upregulates TRIM45 expression in DF-1 cells. To assess the functional role of TRIM45 in ALV-J replication, we employed both gene silencing and overexpression strategies. Strikingly, the overexpression of TRIM45, including a mutant lacking the RING domain, was found to markedly suppress ALV-J replication. In contrast, TRIM45 knockdown via siRNA resulted in an enhanced viral replication, highlighting the importance of TRIM45 limiting ALV-J replication. Mechanistically, overexpression of TRIM45 induces apoptosis in infected cells, independent of its RING domain function. In conclusion, our study demonstrates that chicken TRIM45 acts as a negative regulator of ALV-J replication in vitro by promoting apoptosis in infected cells.RESEARCH HIGHLIGHTSChicken TRIM45 RING domain and protein localization significantly differ from humans.TRIM45 negatively regulates ALV-J replication in vitro.TRIM45 inhibits ALV-J replication by inducing apoptosis in infected cells.

In this study, we investigated the pathological effects of novel goose parvovirus (NGPV) infection on the skeletal muscle, brain, and intestine of naturally affected ducks suffering from locomotor dysfunction as a new approach for a deeper understanding of this clinical form. For this purpose, a total of 97 diseased ducks, representing 24 flocks of different duck breeds (14-75 days old), were clinically examined. In total, 72 tissue pools of intestine, brain, and skeletal muscle samples were submitted for molecular identification. Typical clinical signs among the examined ducks suggested parvovirus infection. Regarding postmortem examination, all examined ducks showed muscle emaciation (100%) either accompanied by congestion (34%) or paleness (66%). Slight congestion, either in the brain (82.5%) or intestine (75.25%), was predominantly detected. Based on molecular identification, the intestine had the highest percentage of positive detection (91.7%), followed by the skeletal muscle (70.8%), and the brain (20.8%). The main histopathological alterations were myofibre atrophy and degeneration, marked enteritis accompanied by lymphocytic infiltration in the lamina propria and submucosa, while the affected brains showed vasculitis, diffuse gliosis, and Purkinje cell degeneration in the cerebellum. Next-generation sequencing further confirmed the presence of a variant strain of goose parvovirus (vGPV) that is globally known as NGPV and closely related to Chinese NGPV isolates. Using immunohistochemistry, the NGPV antigen was positively detected in the muscle fibres, enterocytes, and Purkinje cells in the cerebellum. These findings provided proof of the involvement of virus replication in the locomotor disorders linked to NGPV infection in ducks.

Congenital cleft of the secondary palate occurs when there is failure of one or both maxillary processes to fuse with the nasal septum during embryonic development. Palatal cleft severity can range from a simple focal fissure of the caudal soft palate to full-thickness defects of varied widths involving the entire soft and hard palate. A novel staged medially positioned single mucoperiosteal flap technique in 4 canine patients is reported. This flap technique is based on the major palatine and infraorbital arteries with strategic extractions of maxillary teeth and placement of allograft membrane in 3 of 4 cases for treatment of clefts wider than may be repaired effectively by traditional methods.

A tiered intake assessment approach is presented and applied to derive estimates of maximum potential global propylene glycol (PG) intake from beverage sources. The US and UK markets served as surrogates for the world and the EU region, respectively, to determine the maximum potential exposure for PG in various subpopulations, including brand-loyal consumers. Conservative intake estimates for PG used in non-alcoholic beverages were calculated for toddlers less than 3 years (y), young children 3-9 y, adolescents 10-17 y, adults 18-64 y, elderly 65-74 y, very elderly 75+ y, based on assumed uses in high beverage consumption markets, leveraging either the 2-day food consumption data from the 2013-2016 US National Health and Nutrition Examination Survey or the 4-day food consumption data from the 2008-2017 UK National Diet and Nutrition Survey Rolling Programme. This study shows that safety of PG in beverages at proposed use levels up to 3,000 mg kg^-1 can be supported for any geography, based not only on a refined budget method approach but also on a refined deterministic approach when applying the proposed safe intake (pADI) of 62.5 mg kg bw^-1day^-1. In all refined assessments, intake estimates across all age groups fell close to or well below the pADI even among high consumers at the 95^th percentile.

Carotid body paragangliomas represent an uncommon neoplasm in dogs. The objective of this study was to report outcomes and complications associated with surgical excision of carotid body paragangliomas in 21 dogs. Cases were recruited retrospectively via medical record review from 9 veterinary speciality centres. The perioperative complication rate was 52% (11/21). Complications encountered in this cohort related to removal of carotid body tumour included airway obstruction, aspiration pneumonia, megaesophagus, unilateral laryngeal paralysis, coughing and Horner's syndrome. The overall perioperative mortality rate was 4.7% (1/21 dogs) and median survival time was 554 days for the six patients with known dates of death. One- and two-year survival rates were 61% and 42%, respectively. This is the largest collection of carotid body paraganglioma cases reported in veterinary literature. Based on these results, surgical resection of carotid body paragangliomas was associated with low perioperative mortality and long survival times.

An analytical method was developed for identification and quantification of zilpaterol in bovine liver, meat, heart, and kidney, using liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap HRMS). It was validated in accordance with Commission Implementing Regulation (CIR) EU 2021/808 at six different concentrations, ranging from 0.1 to 5 μg/kg. The mean recoveries ranged from 71% to 99%, while the decision limit (CCα) and detection capability (CCβ) ranges were 0.11-0.12 μg/kg and 0.13-0.15 μg/kg, respectively. The method demonstrated good linearity (R² > 0.9996) and the limits of detection (LODs) and of quantification (LOQs) were in the range of 0.015-0.061 μg/kg and 0.025-0.091 μg/kg, respectively. Out of 200 samples collected from local markets in Egypt, 17 contained zilpaterol residues. Liver samples revealed the highest detection frequency (26%), followed by meat (6%), at mean concentrations of 2.64 and 1.93 μg/kg, respectively.

Senna, a medicinal herb, is highly susceptible to aflatoxin contamination, which often limits the export value of the final products due to the regulatory limits of importing countries. Presence of aflatoxin B1 (AFB₁) was investigated in 229 senna pod samples at various stages from field to storage over three years. Higher incidence of AFB₁ was revealed during the late harvest stage with a mean level of 52.4 µg/kg and a range of LOD-206 µg/kg. Out of 48 late harvest samples, 37 exceeded the AFFB₁ limit of 2 µg/kg. In contrast, the majority of preharvest samples showed lower levels of AFB₁ (1.0 µg/kg). During drying, increase in the mean AFB₁ level to 4 µg/kg was observed and it could further increase to 18.1 μg/kg in storage. These results highlight the status of aflatoxin contamination in senna pods and emphasise the importance of implementing good agricultural practices in senna cultivation to mitigate AFB₁ contamination.

Assessing the contamination of paper and board (P&B) food packaging materials poses significant challenges due to the sensitivity limits of analytical methods and the low precision of sampling processes. This study aims to enhance the understanding of P&B food packaging contamination by investigating the distribution of contaminants at different scales using a combination of chromatographic and spectroscopic techniques. A total of 36 substances were targeted, including phthalates, photoinitiators, and bisphenol A. Key findings reveal that intra-packaging variability can lead to concentration variations by a factor of 2-7. Recycled materials generally exhibit higher contamination levels, with concentrations of certain contaminants reaching up to 700 mg/kg. Microscopy, including confocal laser scanning microscopy (CLSM) and Raman micro-spectroscopy, enabled the identification and differentiation of contaminants, highlighting specific marker molecules and characteristic Raman bands. The study underscores the necessity of comprehensive sampling strategies, advocating for the grinding of entire packaging to obtain representative samples. The introduction of contamination "fingerprints," based on occurrences and correlations between concentrations, offers a promising approach for hazard identification and risk assessment. Overall, the findings contribute to the development of safer and more sustainable food packaging solutions, emphasizing the need for improved analytical techniques and standardized sampling methods in the context of increasing use of recycled materials.