خيارات البحث
النتائج 1 - 6 من 6
Regional distribution of non-human H7N9 avian influenza virus detections in China and construction of a predictive model
2021
Huang, Zeying | Li, Haijun | Huang, Beixun
H7N9 avian influenza has broken out in Chinese poultry 10 times since 2013 and impacted the industry severely. Although the epidemic is currently under control, there is still a latent threat. Epidemiological surveillance data for non-human H7N9 avian influenza from April 2013 to April 2020 were used to analyse the regional distribution and spatial correlations of positivity rates in different months and years and before and after comprehensive immunisation. In addition, positivity rate monitoring data were disaggregated into a low-frequency and a high-frequency trend sequence by wavelet packet decomposition (WPD). The particle swarm optimisation algorithm was adopted to optimise the least squares support-vector machine (LS-SVM) model parameters to predict the low-frequency trend sequence, and the autoregressive integrated moving average (ARIMA) model was used to predict the high-frequency one. Ultimately, an LS-SVM-ARIMA combined model based on WPD was constructed. The virus positivity rate was the highest in late spring and early summer, and overall it fell significantly after comprehensive immunisation. Except for the year 2015 and the single month of December from 2013 to 2020, there was no significant spatiotemporal clustering in cumulative non-human H7N9 avian influenza virus detections. Compared with the ARIMA and LS-SVM models, the LS-SVM-ARIMA combined model based on WPD had the highest prediction accuracy. The mean absolute and root mean square errors were 2.4% and 2.0%, respectively. Low error measures prove the validity of this new prediction method and the combined model could be used for inference of future H7N9 avian influenza virus cases. Live poultry markets should be closed in late spring and early summer, and comprehensive H7N9 immunisation continued.
اظهر المزيد [+] اقل [-]A pilot study to establish an ovalbumin-induced atopic dermatitis minipig model
2021
Kim, Yŏng-gyu | Lee, Ju Young | Hwang, Jeong Ho | Suh, Han Na
Because minipig skin is similar to human skin in anatomy and physiology, establishing an atopic dermatitis (AD) minipig model seems meaningful. We applied 1-fluoro-2,4-dinitrobenzene (DNFB) or ovalbumin onto the back skin of five Yucatan minipigs aged 8–10 months and 19 kg in median weight. Two minipigs with the same parameters served as controls. Both DNFB and ovalbumin mediated epithelial hyperplasia, spongiosis, and immune cell infiltration in the dermis, which is a typical histopathological feature of AD. Moreover, AD upregulated the Th1- and Th2-related cytokine expressions in DNFB- or in ovalbumin-treated skin. Notably, AD-induced minipigs exhibited greater cytokine serum concentrations. Histopathological finding and cytokine analysis revealed that DNFB or ovalbumin mediates AD. However, ovalbumin-treated minipig is a more reliable and precise AD model owing to the DNFB-induced severe skin damage. In summary, ovalbumin-treated skin shows similar AD as human in histopathological and molecular analysis.
اظهر المزيد [+] اقل [-]The protective action of piperlongumine against mycobacterial pulmonary tuberculosis in its mitigation of inflammation and macrophage infiltration in male BALB/c mice
2021
Lu, Nihong | Yang, Yongrui | Li, Xiaofei | Li, Jie | Cheng, Jie | Lv, Zhengxuan | Du, Yingrong
Piperlongumine (PL) is a bioactive alkaloid and medicinal compound of piperamide isolated from the long pepper (Piper longum Linn). It has demonstrated bactericidal action against Mycobacterium tuberculosis (MTB), the cause of pulmonary tuberculosis; nevertheless, immunomodulatory activity had not been identified for it in MTB-triggered granulomatous inflammation. This study investigated if piperlongumine could inhibit such inflammation. Mycobacterium tuberculosis strain H37Rv was subjected to a broth microdilution assay. Piperlongumine at 5, 15, and 25 μg/mL, 0.2% dimethyl sulphoxide as control or 4 μM of dexamethasone were tested in vitro on MH-S murine alveolar macrophages. BALB/c mice were orally administered PL at 50, 100 and 150 mg/kg b.w. after trehalose-6,6-dimycolate (TDM) stimulation. Chemokine and cytokine concentrations were determined in lung supernatants. Flow cytometry and Western blot analysis were performed to determine phosphorylated spleen tyrosine kinase (Syk), c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) pathways. Piperlongumine inhibited inflammatory mediators and adherence of lymphocyte function-associated antigen 1 to MH-S cells following TDM activation. It also improved macrophage clearance of MTB. In TDM-stimulated MH-S cells, PL significantly influenced the macrophage inducible Ca²⁺-dependent lectin receptor (Mincle)-Syk-ERK signalling pathway. Oral dosing of PL effectively suppressed the development of pulmonary granulomas and inflammatory reactions in the TDM-elicited mouse granuloma model. PL as an inhibitor of MTB-triggered granulomatous inflammation may be an effective complementary treatment for mycobacterial infection.
اظهر المزيد [+] اقل [-]In vitro effects of epinephrine, norepinephrine, and dobutamine on lipopolysaccharide-stimulated production of tumor necrosis factor-α, interleukin-6, and interleukin-10 in blood from healthy dogs
2021
Merrill, Kristen M. | Hull, Matthew B. | Stoker, Aaron | DeClue, Amy E.
OBJECTIVE To determine the in vitro effects of epinephrine, norepinephrine, and dobutamine on lipopolysaccharide (LPS)-stimulated production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) in blood from healthy dogs. SAMPLES Blood samples from 9 healthy dogs. PROCEDURES Blood samples were incubated with LPS from Escherichia coli O127:B8 or PBSS (control) for 1 hour. Afterward, the samples were incubated with 10μM epinephrine, norepinephrine, or dobutamine or with saline (0.9% NaCl) solution (control) for 23 hours. Leukocyte viability was assessed by use of trypan-blue exclusion in blood from 2 dogs to ensure cell viability was not altered by the catecholamines. Tumor necrosis factor-α, IL-6, and IL-10 concentrations were measured in the supernatant in duplicate with a canine-specific multiplex bead-based assay. Blood samples from 2 dogs were used to create dose-response curves to evaluate whether the observed cytokine modulation was dependent on catecholamine concentration. RESULTS Incubation of blood with epinephrine and norepinephrine significantly increased LPS-stimulated production of IL-10, compared with the control. Epinephrine and norepinephrine significantly decreased LPS-stimulated production of TNF-α, compared with the control. Epinephrine and norepinephrine did not significantly alter LPS-stimulated production of IL-6. Dobutamine did not alter catecholamine production. CONCLUSIONS AND CLINICAL RELEVANCE Epinephrine and norepinephrine, but not dobutamine, had immunomodulatory effects on LPS-stimulated TNF-α and IL-10 production in blood from healthy dogs in this in vitro model of sepsis. Data suggested that dobutamine may have immune system-sparing effects in dogs with sepsis.
اظهر المزيد [+] اقل [-]Effect of withholding food on serum concentrations of cobalamin, folate, trypsin-like immunoreactivity, and pancreatic lipase immunoreactivity in healthy dogs
2021
Saver, Alexander T. | Steiner, Jörg M. | Hetzel, Scott J. | Lidbury, Jonathan A. | Suchodolski, Jan S. | Pritchard, Jessica C.
OBJECTIVE To evaluate the effects of withholding food on the results for measurements of serum concentrations of cobalamin, folate, canine pancreatic lipase immunoreactivity (cPLI), and canine trypsin-like immunoreactivity (cTLI) in healthy dogs. ANIMALS 11 healthy employee- or student-owned dogs. PROCEDURES Food was withheld from the dogs for 12 hours, baseline blood samples were collected, then dogs were fed. Postprandial blood samples collected 1, 2, 4, and 8 hours later were assessed. A mixed-effects ANOVA model with fasting duration (time) as a fixed factor and dog as a random effect was fit for each analyte variable. Additionally, a mixed-effects ANOVA model controlling for the variable of time was fit to assess whether lipemia affected serum concentrations of the analytes. RESULTS The median serum cobalamin concentration was lower at 4 hours (428 ng/L) and 8 hours (429 ng/L) postprandially, compared with baseline (479 ng/L), but this difference was not clinically meaningful. Although there were no substantial differences in serum concentrations of folate, cPLI, or cTLI, postprandial changes in serum concentrations of cTLI or folate could potentially affect diagnoses in some dogs. CONCLUSIONS AND CLINICAL RELEVANCE Although results indicated that feedings rarely resulted in clinically important differences in the median serum concentrations of cobalamin, folate, cPLI, or cTLI in healthy dogs, given the further processing required for lipemic samples, withholding food for at least 8 hours is an appropriate recommendation when measuring these analytes. Similar research is needed in dogs with gastrointestinal disease to determine whether the withholding of food is necessary when measuring these analytes in affected dogs.
اظهر المزيد [+] اقل [-]Evaluation of two benchtop blood gas analyzers for measurement of electrolyte concentrations in venous blood samples from dogs
2021
OBJECTIVE To assess agreement between 2 benchtop blood gas analyzers developed by 1 manufacturer (BGA 1 and BGA 2 [a newer model with reduced maintenance requirements]) and a reference chemistry analyzer for measurement of electrolyte (sodium, chloride, and potassium) in blood samples from dogs. ANIMALS 17 healthy staff- and student-owned dogs and 23 client-owned dogs admitted to an emergency and intensive care service. PROCEDURES Blood collected by venipuncture was placed in lithium heparin–containing tubes. Aliquots were analyzed immediately with each BGA. Samples were centrifuged, and plasma was analyzed with the reference analyzer. Results for each BGA were compared with results for the reference analyzer by Passing-Bablok regression analysis. Percentage differences between BGA and reference analyzer results were compared with published guidelines for total allowable error. RESULTS Proportional bias was detected for measurement of chloride concentration (slope, 0.7; 95% CI, 0.7 to 0.8), and constant positive bias was detected for measurement of chloride (y-intercept, 34, mmol/L; 95% CI, 16.9 to 38 mmol/L) and potassium (y-intercept, 0.1 mmol/L; 95% CI, 0.1 to 0.2 mmol/L) concentrations with BGA 1. There was no significant bias for measurement of potassium or chloride concentration with BGA 2 or sodium concentration with either BGA. Differences from the reference analyzer result exceeded total allowable error guidelines for ≥ 1 sample/analyte/BGA, but median observed measurement differences between each BGA and the reference analyzer did not. CONCLUSIONS AND CLINICAL RELEVANCE Good agreement with reference analyzer results was found for measurement of the selected electrolyte concentrations in canine blood samples with each BGA.
اظهر المزيد [+] اقل [-]