A problem for dairy cows following milk stasis is to cope with a high risk of intramammary infection and there is a need to initiate an extensive renewal of secretory modules in mammary glands so that milk production in next lactation may be optimized. We recently reported that ultrasonicated Enterococcus faecium SF68 (SF68) is compatible with cow mammary glands and an enhancer of innate immunity during the immediate post‐milk stasis period. The current study further examines the concomitant effect of ultrasonicated SF68 on mammary tissue remodeling. Four Holstein cows each received intramammary infusions of regular antibiotic dry‐cow formula (positive control) and two different doses of SF68 in different quarters. Analyses of individual quarter secretion samples showed faster neutrophil infiltration, earlier modifications in protein composition, including caseins and lactoferrins, as well as more prompt elevation of the specific unit of 92‐kDa matrix metalloproteinase 9 (MMP9) in SF68‐infused quarters compared to the positive controls. Intramammary infusion of ultrasonicated SF68 seems able to accelerate the regression of mammary synthetic capacity and potentiate the breakdown of glandular extracellular matrix, indicating a more efficient mammary gland involution. Correlation analyses imply that the ability of ultrasonicated SF68 to induce faster neutrophil chemotaxis and the associated MMP9 release is partly responsible. 相似文献
The hypothalamus is a critical center for regulating heat retention or dissipation. This study investigated global protein changes in the hypothalamus of broiler‐type Taiwan country chickens (TCCs) after acute heat stress. Twelve TCC hens aged 30 weeks were allocated to groups subjected to acute heat stress at 38°C for 2 hr without recovery, with 2 hr of recovery, and with 6 hr of recovery; a control group was maintained at 25°C. Hypothalami were collected for protein expression analysis at the end of each time point. The results showed 114 protein spots differentially expressed after acute heat stress. Most of the differentially expressed proteins were involved in cellular processes, metabolism, transport, and cellular component organization. Functional annotation analysis suggested that these proteins were related to cellular defensive responses against heat and oxidative stress, detoxification and toxin export/delivery, cytoskeleton integrity, oxygen transport, and neural development. The results of this study suggest that acute heat stress damages the hypothalamus of broiler‐type TCCs through oxidative stress and provokes a series of responses to stabilize protein structures, degrade misfolded proteins, and remodel cytoskeletons for attenuating the detrimental effects by acute heat stress. 相似文献
This study investigated the concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and polycyclic aromatic hydrocarbons (PAHs) in sediments collected from gully pots for road drainage in Hong Kong. The presence and intensity of anthropogenic contamination of road gully sediments were assessed. Identifications of potential sources of trace elements and PAHs were performed to help understand the situation for future control of pollution to the land and aquatic environments.
Materials and methods
Gully sediment samples were collected from gully pots of 18 roads that are potentially exposed to different pollution sources in Hong Kong. The selection of roads considered different road features, adjacent land uses, and traffic volumes. Composite samples were collected for the analysis of trace elements (Cd, Cr, Cu, Pb, Ni, and Zn) and PAHs by an accredited environmental testing laboratory. Geo-accumulation index (Igeo), contamination factor (Cf), modified degree of contamination (mCd), ecological risk factor (Er), and pollution load index (PLI) were used to assess the level of ecological risk of trace element contamination. Positive matrix factorization (PMF) and PAH diagnostic ratios were applied to identify the sources of trace elements and PAHs.
Results and discussion
Elevated trace element concentrations were commonly found in gully sediments. The concentrations of Zn (267–3700 mg kg?1) were the highest compared to the other trace elements. Noticeable high concentrations of Cu (27–1020 mg kg?1), Pb (21–332 mg kg?1), and Cr (14–439 mg kg?1) were found in all samples. The PAH contents were moderate to high (0.6 to 24.7 mg kg?1). Commercial/industrial emissions and road features that cause frequent acceleration-deceleration and turning events showed important influences on the contaminant levels. Strong correlations between the concentrations of Cd, Cr, Pb, and Zn were identified, implying that these trace elements are likely from common sources. The contamination assessment indices reflect significant sediment pollution. The ecological risk ranges from the considerable/moderate-risk class to over the high-risk class.
Conclusions
The collected gully sediments are identified as highly contaminated and need to be isolated from the environment upon final disposal. Through the comprehensive analysis of the collected data, this study provides a detailed insight into the contaminant levels of road gully sediments and potential sources of contamination. Disposal of gully sediments and potential impacts due to release of contaminants into the downstream aquatic environment during rainstorm events should receive attention and need further investigation.