Subzero saline chilling with or without prechilling in icy water improved chilling efficiency and meat tenderness of broiler carcasses

Freshly slaughtered carcasses need to be chilled to improve product quality, meat safety, and processing efficiency. This research investigated the effect of subzero saline chilling (SSC) on broiler carcasses with or without prechilling in icy water. Water immersion chilling at 0.5°C (WIC) or SSC at 4% NaCl/-2.41°C (SSC) was a major chilling step. For the combination of pre- and postchilling, the warm water immersion chilling (WWIC) at 10°C was used as prechilling and the WIC as postchilling (WWIC-WIC), and WIC was used as prechilling and the SSC as postchilling (WIC-SSC). The internal temperature of breast fillets was monitored during chilling. Carcasses in a prechiller were transported to a postchiller when their internal temperature reached 15°C. Chilling was completed when the carcass temperature reached 4.4°C or below, and breast fillets were harvested at 3-h postmortem to measure the pH and sarcomere length. Color (L*, a*, and b*) values were evaluated on both breast skin and skinless breast surfaces. Meat tenderness was evaluated using the breast fillets after overnight storage and cooking to an internal temperature of 76°C. The carcasses in the SSC and WIC-SSC showed shorter chilling times (85-91 min) than those (100-144 min) of WIC and WWIC-WIC. A higher chilling yield was observed for the carcasses in WIC-SSC, and a lower cooking yield was seen for the carcasses in WWIC-WIC than other chilling methods (P < 0.05). The breast fillets of broilers in the SSC and WIC-SSC showed lower shear forces and longer sarcomere length than the WIC and WWIC-WIC. No difference was found for L* and a* values, while lower b* value was observed in the SSC than the other chilling methods (P < 0.05). Based on these results, chilling of broiler carcasses in the SSC (4% NaCl/-2.41°C) with or without prechilling in WIC at 0.5°C significantly improved chilling efficiency and meat tenderness, with minor color changes on carcasses.

P-202 Improvement of in vitro implantation competence in human trophoblastic spheroids and mouse blastocysts by extracellular vesicles from human follicular fluid

Study question

How do extracellular vesicles (EVs) from human follicular fluid (hFF) affect the implantation process?

Summary answer

The EVs from hFF support the migration of mouse blastocysts and improve the mRNA expression of implantation process in human trophoblastic spheroids and mouse blastocysts.

What is known already

The EVs in hFF contains proteins, mRNAs, and microRNAs (miRs) that can mediate intercellular communication. Some miRs were found to be enriched in EVs of hFF. It has been demonstrated that EVs play different and important roles in the reproductive process such as oocyte maturation, embryo development and implantation. However, the effects of EVs in hFF on the trophoblast migration of in vitro implantation competence remain unclear. We found and analyzed the enriched miRs in EVs of hFF and investigated the effects of EVs on the implantation competence using in vitro outgrowth models using human trophoblastic spheroids and mouse blastocysts.

Study design, size, duration

Mouse 2-cell embryos were collected and then further in vitro cultured up to blastocyst stage. We prepared spheroids with trophoblastic cells, JAr mixed JEG-3 cells (JmJ) of 1:1 ratio. For outgrowth assay, the culture dishes with fibronectin-coated were made 2 hrs before transferring trophoblastic spheroids and mouse blastocysts. After 72 hrs of outgrowth assay, the migration areas of trophoblasts were measured, and qRT-PCR and Western blot were analyzed.

Participants/materials, setting, methods

After collecting the hFF samples in IVF clinic, immediately the EVs were isolated using the conventional ultracentrifugation (UC) method, and stored at -80 °C. Amounts of specific miRNAs were analyzed to confirm the specific miRNA of EVs compared to hFF by qRT-PCR. Protein concentrations were determined and adjusted for supplementation volume.

Main results and the role of chance

The EVs from hFF were prepared by UC, and the size range of EVs were 20∼300 nm (average 136.9±5.6 nm; n = 10) in nanoparticle tracking analyzer. And the EVs were examined via transmission electron microscopy and Western blotting to the exosomal markers CD63, CD81, and TSG101. We conformed miRNAs that enriched in EVs from hFF such as miR10b, miR503, and miR654. In outgrowth assay with human trophoblastic spheroids, the migration areas did not show a difference between control and supplementation of EVs groups. However, the expressions of adhesion molecules ( ITGαV, β3 and β5 ) were increased in supplementation of 2.5 μg/mL EVs compared to control group. In mouse blastocysts, supplementation of EVs significantly increased the trophoblast migration areas than those of control group without EVs. Also the expression patterns of Oct4, Lif, PLGF5 were higher in supplementation of EVs compared to control group. Taken together, EVs from hFF could support the migration of human trophoblastic spheroids and mouse blastocysts in vitro.

Limitations, reasons for caution

Characterization of EVs from hFF was not fully evaluated in various proteins, hormones and nucleic acids. The effects of EVs in hFF on implantation process should be evaluated in primary trophoblastic cells and in vivo mouse model of embryo transfer.

Wider implications of the findings

This study demonstrated that the EVs of hFF could improve the implantation and migration of trophoblasts in vitro. These findings suggest that the EVs of hFF could apply to increase the implantation and the pregnancy rate in human IVF-ET program.

Trial registration number

not applicable

Carbon Monoxide Activates PERK-Regulated Autophagy to Induce Immunometabolic Reprogramming and Boost Antitumor T-cell Function

Mitochondria and endoplasmic reticulum (ER) share structural and functional networks and activate well-orchestrated signaling processes to shape cells' fate and function. While persistent ER stress (ERS) response leads to mitochondrial collapse, moderate ERS promotes mitochondrial function. Strategies to boost antitumor T-cell function by targeting ER-mitochondria cross-talk have not yet been exploited. Here, we used carbon monoxide (CO), a short-lived gaseous molecule, to test whether engaging moderate ERS conditions can improve mitochondrial and antitumor functions in T cells. In melanoma antigen-specific T cells, CO-induced transient activation of ERS sensor protein kinase R-like endoplasmic reticulum kinase (PERK) significantly increased antitumor T-cell function. Furthermore, CO-induced PERK activation temporarily halted protein translation and induced protective autophagy, including mitophagy. The use of LC3-GFP enabled differentiation between the cells that prepare themselves to undergo active autophagy (LC3-GFPpos) and those that fail to enter the process (LC3-GFPneg). LC3-GFPpos T cells showed strong antitumor potential, whereas LC3-GFPneg cells exhibited a T regulatory-like phenotype, harbored dysfunctional mitochondria, and accumulated abnormal metabolite content. These anomalous ratios of metabolites rendered the cells with a hypermethylated state and distinct epigenetic profile, limiting their antitumor activity. Overall, this study shows that ERS-activated autophagy pathways modify the mitochondrial function and epigenetically reprogram T cells toward a superior antitumor phenotype to achieve robust tumor control.

SIGNIFICANCE

Transient activation of ER stress with carbon monoxide drives mitochondrial biogenesis and protective autophagy that elicits superior antitumor T-cell function, revealing an approach to improving adoptive cell efficacy therapy.

Effects of hot water spray and sub-zero saline chilling on bacterial decontamination of broiler carcasses

Reduction of Salmonella on poultry carcasses is one way to prevent salmonellosis. The purpose of this research was to evaluate the effects of subzero saline chilling (SSC) with/without hot water spray (HWS) on broiler carcasses prior to chilling for bacterial reduction. Eviscerated broiler carcasses were subjected to water immersion chilling (WIC, 0% NaCl/0.5°C) or SSC (4% NaCl/-2.41°C) with/without prior HWS at 71°C for 1 min. Broiler carcasses in SSC were chilled faster than those in WIC, regardless of HWS. The combination of HWS and SSC resulted in the best reduction of mesophilic aerobic bacteria, Escherichia coli, and total coliforms on the carcasses over the WIC, SSC, and HWS/WIC. No Salmonella was detected on the carcasses in SSC and HWS/SSC while Salmonella positive was observed on the carcasses chilled in WIC and HWS/WIC. A trace of Gram-negative genus was detected on carcasses in HWS/SSC while many other microbiomes were observed on those in WIC, SSC, and HWS/WIC when quantitative microbiota profiles of 16S rRNA gene sequences were evaluated. Based on these results, chilling of broiler carcasses in 4% NaCl/-2.41°C after HWS at 71°C for 1 min significantly reduced carcass chilling time and bacterial contamination over the control chilling.

Research Note: Subzero saline chilling improved chilling efficiency and bacterial reduction of turkey carcasses

The poultry industry has attempted to improve carcass chilling efficiency, meat quality, and product safety. The purpose of this research was to investigate the effects of subzero saline chilling on carcass chilling time and microbial safety. Eviscerated tom turkeys were randomly picked from a local turkey processing plant and subjected to chilling in one of the 3 chilling solutions: 1) 0% NaCl/0.5°C (ice slurry control), 2) 4% NaCl/-2.41°C, and 3) 8% NaCl/-5.08°C. The turkey carcasses in subzero saline solutions were chilled more efficiently and reduced the chilling time over the carcasses in ice slurry solution. No significant difference was observed for carcass chilling yield and fillet cooking yield regardless of chilling method (P > 0.05). The number of mesophilic aerobic bacteria (MAB), Escherichia coli (E. coli), and total coliform cells were significantly reduced in the carcasses chilled in subzero saline solutions over the icy control, except MAB in 4% NaCl/-2.41°C (P < 0.05). Based on these results, the chilling of turkey carcass in subzero saline solution appears to improve carcass chilling efficiency and bacterial reduction, especially Gram-negative bacteria such as E. coli and total coliforms.

Effects of subzero saline chilling on broiler chilling efficiency, meat quality, and microbial safety

The poultry industry has attempted to improve carcass chilling efficiency, meat quality, and product safety. The purpose of this research was to investigate the effects of subzero saline chilling on carcass chilling, breast fillet tenderness, and microbial safety. After evisceration, broiler carcasses were chilled using ice slurry control (0% NaCl/0.5°C) or subzero saline solutions (3% NaCl/-1.8°C and 4% NaCl/-2.41°C). Broiler carcasses in the subzero saline solutions were chilled efficiently and reduced the chilling time by 11% in 3% NaCl/-1.8°C and 37% in 4% NaCl/-2.41°C over the ice slurry chilling. The breast fillets of broiler carcasses in 4% NaCl/-2.41°C were significantly tenderized than those in water control (P < 0.05), with an intermediate value observed in 3% NaCl/-1.8°C. Before chilling, broiler carcasses possessed mesophilic aerobic bacteria, Escherichia coli, and total coliforms for 3.81, 0.78, and 1.86 log cfu/g, respectively, which were significantly reduced after chilling in 3% NaCl/-1.8°C or 4% NaCl/-2.41°C solution over the water control (P < 0.05), except the mesophilic aerobic bacteria. Based on these results, chilling of boiler carcass in 4% NaCl/-1.8°C solution appears to improve carcass chilling efficiency, meat tenderness, and bacterial reduction for E. coli and total coliforms.

Impact of ethanol and ultrasound treatment on mesophilic aerobic bacteria, coliforms, and Salmonella Typhimurium on chicken skin

The present study evaluated the efficacy of ethanol treatment (0, 30, 50, or 70%) alone or in combination with ultrasound (37 kHz, 380 W) for the reduction of natural indigenous mesophilic aerobic bacteria (MAB), coliforms, and inoculated Salmonella Typhimurium on chicken skin. Bacterial cells with loose, intermediate, or tight attachment to chicken skin were recovered by shaking in an incubator (200 rpm) for 5 min, stomaching for 1 min, or blending for 1 min, respectively. Chicken skins were inoculated with a suspension (7 log CFU/mL) of S. Typhimurium. Ethanol reduced the number of MAB, coliforms, and S. Typhimurium on the chicken skin in a concentration-dependent manner, whereas ultrasound treatment without ethanol was ineffective. A combination of 70% ethanol with ultrasound treatment was the most effective in reducing S. Typhimurium populations with loose, intermediate, and tight attachment (reduction by 2.86 log CFU/g, 2.49 log CFU/g, and 1.63 log CFU/g, respectively). However, chicken skin treated with 50% ethanol alone or with a combination of >50% ethanol and ultrasound showed significant changes in Hunter color values (a* and b*) and texture (shear force) (P > 0.05). On the other hand, a combination of 30% ethanol and ultrasound yielded the best results, leading to a reduction of S. Typhimurium by a >1.0 log CFU/g, but did not alter the color or texture of chicken skin. Thus, a combination of 30% ethanol and ultrasound appears to be the optimum treatment for reduction of microbial contamination in production and distribution of skin-on chicken products, and enhance poultry safety without decreasing food quality.

Comparison of raw meat quality and protein-gel properties of turkey breast fillets processed by traditional or cold-batter mincing technology

This study was conducted to evaluate the effects of cold batter mincing on meat quality and protein functionality, using turkey fillets that were chill-boned (CB) or hot-boned (HB) with crust-freeze-air-chilling (HB-¼CFAC) at -12°C. For each of four replications, 48 toms (male) were raised and processed at Michigan State University Poultry Farm and Meat Laboratory, respectively. After evisceration, the turkeys were subjected to one of the four treatments: (1) traditional mincing of CB fillets after water immersion chilling (WIC); (2) cold batter mincing of WIC, CB, quarter-sectioned (¼), and CB-¼CFAC; (3) traditional mincing of HB-¼CFAC fillets; and (4) cold batter mincing of HB-¼CFAC fillets. Before mincing, the pH and R-values of turkey fillets in HB-¼CFAC were higher and lower, respectively, than those in CB fillets. During cold-batter mixing, the initial batter temperatures at -1.5 to -2.1°C reached 1.5°C and 14°C at 6 and 12 min, respectively, and ended at 26 to 31°C at 24 min. During traditional mincing, the initial batter temperatures at 3 to 4°C increased by ∼10°C every 6 min, and ended at 32 to 35°C with higher batter temperatures seen for the 2% salt than the 1% salt batter. Dynamic rheological properties indicated that the cold-batter mincing showed elevated G' compared to the batters of traditional mincing, regardless of mixing time, indicating that the gel-setting temperature was reduced in the cold-batter mincing, potentially due to the different amounts of extracted protein and structural change. After cooking, improved cooking yield and protein functionality were observed in the batter of HB-¼CFAC fillets than the batter of CB fillets as well as in the batter of 2% salt than the batter 1% salt (P < 0.05). These results indicated that HB-¼CFAC fillets produced superior raw meat quality over the CB fillets, and cold batter mincing of HB-¼CFAC fillets significantly improved protein functionality compared with the traditional mincing of CB fillets (P < 0.05).

Sleep Latency in Men and Sleep Duration in Women Can Be Frailty Markers in Community-Dwelling Older Adults: The Korean Frailty and Aging Cohort Study (KFACS)

OBJECTIVES

To test whether sleep disturbances are associated with frailty in older men and women.

DESIGN

Cross-sectional analysis of cohort study data. The participants were 1168 community-dwelling older adults aged 70 to 84 years who took part in the Korean Frailty and Aging Cohort Study and completed both self-reported sleep parameters and assessment of frailty. Univariate and multivariate survey logistic regression models were used to calculate odds ratios (OR) with 95% confidence intervals (CI) for frailty. Frailty was defined using the Fried's criteria.

RESULTS

Frailty was associated with sleep latency in men. The odds ratio for this association was 3.39 (95% CI 1.31-8.76) after adjusting for age, body mass index (BMI), physical activity, and select comorbidities, and 2.16 (95% CI 0.75-6.23) after further adjusting for depression. Frailty was associated with long sleep duration of more than 8 hours a night in women. The odds ratio for this association was 3.95 (95% CI, 1.27-12.33) after adjusting for age, BMI, physical activity, select comorbidities, and the number of medications.

CONCLUSION

Prolonged sleep latency (≥60 minutes) in men and long sleep duration (>8hr per night) in women were each independently associated with higher odds of frailty. Long sleep latency in elderly men and long sleep duration in elderly women may suggest they have a high chance of frailty.

Antilisterial effects of hop alpha and beta acids in turkey slurry at 7 and 37°C

Chemical components of hop resins effectively inhibit the growth of L. monocytogenes in microbiological culture media. This study was conducted to investigate antilisterial activities of hop α- and β-acid in turkey slurry. Turkey slurries were inoculated with L. monocytogenes, formulated with hop α- or β-acid from 0 to 1,000 ppm, and incubated at 37°C for 24 h or at 7°C for 12 days. During storage at 37°C for 24 h, L. monocytogenes populations were reduced from 2.40 log CFU/g to non-detectable (<1 log CFU/g) in α-acid at ≥750 ppm and β-acid at 1,000 ppm, whereas the control (0 ppm) allowed the pathogen to grow to 8.0 log CFU/g. During storage at 7°C for 12 d, the slurry treated with α-acid at ≥100 ppm and β-acid at ≥500 ppm showed listeristatic effects, while listericidal effects were observed in the slurries at 1,000 ppm, regardless of hop acid type. Hop α-acid ≤ 50 ppm and β-acid ≤ 100 ppm failed to inhibit L. monocytogenes, and the pattern of bacterial growth was similar to that of control with no significant difference (P > 0.05). Based on these results, the concentration of α-acid > 100 ppm or β-acid > 500 ppm is minimally required to inhibit L. monocytogenes when turkey batters are formulated with hop acids as a single antilisterial agent prior to cooking and storage at 7°C.

Application of calcium oxide (CaO, heated scallop-shell powder) for the reduction of Listeria monocytogenes biofilms on eggshell surfaces

This study investigated bactericidal activity of 0.05 to 0.50% calcium oxide (CaO) against planktonic cells in tryptic soy broth (TSB) and biofilms of Listeria monocytogenes on eggshell surfaces. The bactericidal activity of CaO against planktonic cells and biofilms of L. monocytogens significantly (P < 0.05) increased log reductions with increasing concentrations of CaO. Exposure to 0.05 to 0.50% CaO for one min reduced planktonic cells in TSB cell suspensions by 0.47 to 3.86 log10CFU/mL and biofilm cells on the shell surfaces by 0.14 to 2.32 log10CFU/cm2. The Hunter colors of eggshells ("L" for lightness, "a" for redness, and "b" for yellowness), shell thickness (puncture force), and sensory quality (egg taste and yolk color) were not changed by 0.05 to 0.50% CaO treatment. The nonlinear Weibull model was used to calculate CR = 3 values as the CaO concentration of 3 log (99.9%) reduction for planktonic cells (R2 = 0.96, RMSE = 0.26) and biofilms (R2 = 0.95, RMSE = 0.18) of L. monocytogens. The CR = 3 value, 0.31% CaO for planktonic cells, was significantly (P < 0.05) lower than 0.57% CaO for biofilms. CaO could be an alternative disinfectant to reduce planktonic cells and biofilms L. monocytogenes on eggshell surface in egg processing plants.

Astrocytic water channel aquaporin-4 modulates brain plasticity in both mice and humans: a potential gliogenetic mechanism underlying language-associated learning

The role of astrocytes in brain plasticity has not been extensively studied compared with that of neurons. Here we adopted integrative translational and reverse-translational approaches to explore the role of an astrocyte-specific major water channel in the brain, aquaporin-4 (AQP4), in brain plasticity and learning. We initially identified the most prevalent genetic variant of AQP4 (single nucleotide polymorphism of rs162008 with C or T variation, which has a minor allele frequency of 0.21) from a human database (n=60 706) and examined its functionality in modulating the expression level of AQP4 in an in vitro luciferase reporter assay. In the following experiments, AQP4 knock-down in mice not only impaired hippocampal volumetric plasticity after exposure to enriched environment but also caused loss of long-term potentiation after theta-burst stimulation. In humans, there was a cross-sectional association of rs162008 with gray matter (GM) volume variation in cortices, including the vicinity of the Perisylvian heteromodal language area (Sample 1, n=650). GM volume variation in these brain regions was positively associated with the semantic verbal fluency. In a prospective follow-up study (Sample 2, n=45), the effects of an intensive 5-week foreign language (English) learning experience on regional GM volume increase were modulated by this AQP4 variant, which was also associated with verbal learning capacity change. We then delineated in mice mechanisms that included AQP4-dependent transient astrocytic volume changes and astrocytic structural elaboration. We believe our study provides the first integrative evidence for a gliogenetic basis that involves AQP4, underlying language-associated brain plasticity.

A modified-live porcine reproductive and respiratory syndrome virus (PRRSV)-1 vaccine protects late-term pregnancy gilts against heterologous PRRSV-1 but not PRRSV-2 challenge

The objective of this study was to determine the efficacy of a commercially available porcine reproductive and respiratory syndrome virus (PRRSV)-1 modified-live virus (MLV) vaccine against PRRSV-1 and PRRSV-2 challenge in late-term pregnancy gilts. Gilts were vaccinated with the PRRSV-1 MLV vaccine at 4 weeks prior to breeding and then challenged intranasally with PRRSV-1 or PRRSV-2 at 93 days of gestation. After PRRSV-1 challenge, vaccinated pregnant gilts had a significantly longer gestation period, significantly higher numbers of live-born and weaned piglets and a significantly lower number of stillborn piglets at birth compared to unvaccinated pregnant gilts. No significant improvement in reproductive performance was observed between vaccinated and unvaccinated pregnant gilts following PRRSV-2 challenge. Vaccinated pregnant gilts also exhibited a significantly improved reproductive performance after challenge with PRRSV-1 compared to vaccinated pregnant gilts following PRRSV-2 challenge. The PRRSV-1 MLV vaccine was able to reduce PRRSV-1 but not PRRSV-2 viremia in pregnant gilts. Vaccinated gilts also showed a significantly higher number of PRRSV-1-specific IFN-γ-secreting cells (IFN-γ-SC) compared to PRRSV-2-specific IFN-γ-SC. The data presented here suggest that the vaccination of pregnant gilts with a PRRSV-1 MLV vaccine provides good protection against PRRSV-1 but only limited protection against PRRSV-2 challenge in late-term pregnancy gilts based on improvement of reproductive performance, reduction in viremia and induction of IFN-γ-SC.

CD38-NAD+Axis Regulates Immunotherapeutic Anti-Tumor T Cell Response

Heightened effector function and prolonged persistence, the key attributes of Th1 and Th17 cells, respectively, are key features of potent anti-tumor T cells. Here, we established ex vivo culture conditions to generate hybrid Th1/17 cells, which persisted long-term in vivo while maintaining their effector function. Using transcriptomics and metabolic profiling approaches, we showed that the enhanced anti-tumor property of Th1/17 cells was dependent on the increased NAD⁺-dependent activity of the histone deacetylase Sirt1. Pharmacological or genetic inhibition of Sirt1 activity impaired the anti-tumor potential of Th1/17 cells. Importantly, T cells with reduced surface expression of the NADase CD38 exhibited intrinsically higher NAD⁺, enhanced oxidative phosphorylation, higher glutaminolysis, and altered mitochondrial dynamics that vastly improved tumor control. Lastly, blocking CD38 expression improved tumor control even when using Th0 anti-tumor T cells. Thus, strategies targeting the CD38-NAD⁺ axis could increase the efficacy of anti-tumor adoptive T cell therapy.

Comparison of commercial type 1 and type 2 PRRSV vaccines against heterologous dual challenge

This study was to compare the effect of vaccination of pigs with either type 1 or type 2 porcine reproductive and respiratory syndrome virus (PRRSV) against heterologous dual challenge of both genotypes. Pigs were administered type 1 (UNISTRAIN PRRS) or type 2 (Fostera PRRS) PRRSV vaccine at 28 days of age and inoculated intranasally with both genotypes at 63 days of age. Vaccination of pigs with type 1 PRRSV was able to reduce the levels of type 1 but not type 2 PRRSV viraemia, whereas vaccination of pigs with type 2 PRRSV was able to reduce the levels of type 1 and type 2 PRRSV viraemia against a dual challenge. Vaccination of pigs with type 2 PRRSV significantly reduced lung lesions after dual challenge compared with vaccination of pigs with type 1 PRRSV. Vaccination of pigs with type 2 PRRSV induced higher numbers of type 1 and type 2 PRRSV-specific interferon-γ secreting cells compared with vaccination of pigs with type 1 PRRSV after dual challenge. The results of this study demonstrated that vaccination of pigs with type 2 PRRSV is efficacious in protecting growing pigs from respiratory disease after heterologous dual type 1 and type 2 PRRSV challenge compared with vaccination of pigs with type 1 PRRSV.

In-situ Hybridization for the Detection of Sacbrood Virus in Infected Larvae of the Honey Bee (Apis cerana)

The aim of this study was to develop and use in-situ hybridization (ISH) for the detection and localization of the sacbrood virus (SBV) in Korean honey bee (Apis cerana) larvae that were infected naturally with SBV. A 258 base pair cDNA probe for SBV was generated by polymerase chain reaction. Cells positive for viral genome typically showed a dark brown reaction in the cytoplasm. SBV was detected consistently in trophocytes and urocytes. The ISH was successfully applied to routinely fixed and processed tissues and thus should prove helpful in the diagnosis and characterization of viral distribution in infected larvae.

Differential Expression of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Open Reading Frame 5, but not Apoptogenic Cytokines, Contribute to Severe Respiratory Disease in Pigs Infected with Type 2 PRRSV Compared with Pigs Infected with Type 1 PRRSV

The aim of this study was to compare the expression of open reading frame 5 (ORF5) of porcine reproductive and respiratory syndrome virus (PRRSV) and apoptogenic cytokines in the lungs from pigs infected with type 1 and type 2 PRRSV. Microscopical lung lesion scores and the mean number of apoptotic cells were significantly (P <0.05) higher in pigs with type 2 PRRSV infection than in those with type 1 PRRSV infection. The score for the mean number of PRRSV ORF5-positive cells per unit area of lung was significantly (P <0.05) higher in pigs with type 2 PRRSV infection. There were no significant differences in the expression of tumour necrosis factor-α and interleukin-1 in lung tissues between type 1 and type 2 PRRSV-infected pigs. The severity of microscopical lung lesions and the number of apoptotic cells correlated well with the number of PRRSV ORF5-positive cells. Therefore, differential expression of PRRSV ORF5, but not apoptogenic cytokines, may attribute to the severity of lung lesions and apoptosis in lungs in PRRSV infection. These results suggest that expression of PRRSV ORF5 may be a critical determinant for different virulence between PRRSV genotypes in terms of respiratory disease.

Improvement of turkey breast meat quality and cooked gel functionality using hot-boning, quarter sectioning, crust-freeze-air-chilling and cold-batter-mincing technologies

The effect of rapid carcass chilling on breast meat quality was evaluated using commercial (COMM) and random-bred (RB) turkeys. Immediately after slaughter, 48 turkeys from COMM or RB line were randomly subjected to one of four chilling methods: 1) water-immersion chilling (WIC) of the carcasses at 0°C ice slurry, 2) WIC after temperature abuse (TA) of the carcasses at 40°C for 30 min (TA-WIC), 3) hot-boning, quarter sectioning, and crust-freeze-air-chilling (HB-(1)/4CFAC) of breast fillets at -12°C, and 4) HB-(1)/4CFAC of fillets after TA of carcasses (TA-HB-(1)/4CFAC). The TA increased carcass and fillet temperatures by ∼1.3 and ∼4.1°C, respectively, regardless of turkey line, whereas HB-(1)/4CFAC of fillets required 28 and 33% of carcass chilling time for COMM and RB, respectively. During chilling, COMM breast pH rapidly reduced from 6.04 to 5.82, resulting in a significantly lower pH than RB after chilling (P < 0.05), whereas COMM R-value sharply increased from 1.17 to 1.43, causing no difference from RB (P > 0.05). Significantly higher L* value and cooking yield (P < 0.05) were seen in the samples of TA and WIC than those of no TA and HB-(1)/4CFAC, respectively, with no difference observed between COMM and RB fillets (P > 0.05). Higher values of hardness, gumminess, and chewiness were found for RB, no TA, and HB-(1)/4CFAC gels than COMM, TA, and WIC, respectively. These results generally indicated that protein quality and textural properties of turkey fillets were improved, regardless of strains or temperature abuse, using HB-(1)/4CFAC technology.

Quantification of loosely associated and tightly associated bacteria on broiler carcass skin using swabbing, stomaching, and grinding methods

This research was conducted to quantify bacterial populations after swabbing or stomaching, followed by grinding the swabbed or stomached broiler skins. For each of 3 replications, 3 eviscerated broilers were randomly taken from a processing line in a local broiler processing plant. Ten swabs and 10 stomachs per bird were conducted on the left- and the right-side skins (10×7 cm), respectively, which were then finally ground. Results indicated that mesophilic aerobic bacteria (MAB) in the first swabbed sample were significantly lower than those in the first stomached sample (P<0.05), with no difference seen for the remaining sampling times (P>0.05). During 10 swabbings followed by final grinding, 8, 9, and 83% of MAB were detected after the first swabbing, after the second through 10th swabbings, and after final grinding of the skin, respectively. During 10 stomachings followed by the final grinding, 17, 18, and 65% of MAB were detected after the first stomaching, after the second through 10th stomachings, and after final grinding of the skin, respectively. Escherichia coli (E. coli) and coliforms were significantly higher in the first stomaching than those in the first swabbing (P<0.05), with no difference seen between the 2 sampling methods for the rest sampling times (P>0.05). Populations of E. coli and coliforms decreased step-wisely from the highest after grinding to the intermediate after first and second sampling, and to the least after 10th sampling (P<0.05), regardless of swabbing or grinding. In this study, less than 35% of MAB seemed loosely associated in the skin of eviscerated broiler, whereas more than 65% of MAB looked tightly associated, which were not recovered by stomaching or swabbing even 10 times but were recovered by grinding the skin.

Fear responses and postmortem muscle characteristics of turkeys of two genetic lines

Commercial turkey production has increased greatly in recent decades. Along with increased production, problems with turkey meat quality have also increased. Research with other species has demonstrated that differences in meat quality exist among pigs and cattle differing in characteristics such as fearfulness. However, associations between fear responses and postmortem (PM) muscle characteristics related to the meat quality of turkeys have not been examined. This study evaluated the test-retest repeatability of responses of male commercial (COMM) and randombred (RB) turkeys in an open field (OF) test, which is used to assess fear and activity levels of poultry. Another objective of this study was to evaluate the relationship between behavioral OF responses and PM breast muscle characteristics (pH and R-value) that are related to meat quality. Thirdly, this study evaluated differences in pH and R-value between the turkey lines. Male COMM and RB turkeys were each housed in groups in 4 pens. Turkeys were individually tested in an OF (2.74×2.74 m, divided into 81 squares) at 1, 4, and 11 wk (COMM N=27; RB N=33). Turkeys were then grouped into clusters based on a cluster analysis of OF behavior. Turkeys were processed and meat quality characteristics were evaluated at 15-17 wk for COMM and 20-21 wk for RB turkeys. Results were analyzed using a mixed model (SAS 9.4). Breast muscle pH and R-value did not differ between genetic lines, and there were no differences in pH and R-value among clusters within genetic lines. These findings suggest that OF responses measured during rearing are not related to PM breast muscle pH and R-value, which ultimately affect meat quality. Further research is needed to assess whether other types of fear responses are associated with meat quality and whether differences in R-value between genetic lines are associated with differences in other meat quality characteristics.

Changes in students' perceptions of their dental education environment

OBJECTIVES

To examine the 'Expected' and 'Actual' educational environment experienced by a cohort of Bachelor of Dental Surgery (BDS) students at the University of Otago's Faculty of Dentistry using the Dundee Ready Educational Environment Measure (DREEM).

METHODS

Cohort members were asked to complete five DREEM surveys over the four-year BDS programme. Student expectations at the beginning of their first year were assessed using a modified version of the DREEM questionnaire, while following (standard) DREEM questionnaires at the end of each professional year addressed students' 'Actual' perception of the educational environment.

RESULTS

Sixty-six students (99%) completed at least one questionnaire. Overall, the BDS students' perceptions of their educational environment tended to be positive and students identified both perceived strengths and weaknesses in the BDS programme. However, more negative than positive shifts were reported between the 'Expected' and 'Actual' individual DREEM individual items, suggesting that BDS students initially expected more from their educational environment than they actually experienced. Individual DREEM outcomes undergoing negative and positive shifts differed over the years and varied in number. These may be explained, in part, by changes in the curriculum focus from year to year.

CONCLUSION

The students' changing DREEM responses over time revealed anticipated and perceived strengths and weaknesses of the BDS curriculum, as well as shifts in students' perceptions in response to curricular changes. However, our findings highlight the potential usefulness for dental education of a measure for use that takes the unique aspects of the dental education environment into account.

Two Commercial Type 1 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-Modified Live Vaccines Reduce Seminal Shedding of Type 1 PRRSV but not Type 2 PRRSV in Infected Boars

The objective of this study was to compare the effects of two commercial type 1 porcine reproductive and respiratory syndrome virus (PRRSV)-modified live vaccines on type 1 and type 2 PRRSV shedding in the semen of experimentally infected boars. Upon challenge with PRRSV, unvaccinated boars exhibited an increase in daily rectal temperature (39.4-39.7°C). Vaccination of boars with type 1 PRRSV significantly reduced the amount of type 1 PRRSV load in blood and semen after challenge with type 1 PRRSV, but barely reduced the amount of type 2 PRRSV load in blood and semen after the type 2 PRRSV challenge. There were no significant differences in the reduction of viremia and seminal shedding of type 1 and type 2 PRRSV between the two commercial vaccines. The seminal shedding of PRRSV is independent of viremia. The reduction of type 1 PRRSV seminal shedding coincided with the appearance of type 1 PRRSV-specific interferon-γ secreting cells (IFN-γ-SC) in vaccinated type 1 PRRSV-challenged boars. The frequencies of type 1 PRRSV-specific IFN-γ-SC induced by type 1 PRRSV vaccine are relatively high compared to type 2 PRRSV-specific IFN-γ-SC induced by the same vaccine which may explain why type 1 PRRSV vaccine is more effective in reducing seminal shedding of type 1 PRRSV when compared to type 2 PRRSV in vaccinated challenged boars. These results provide clinical information on how to reduce seminal shedding of type 1 PRRSV in boars using type 1 PRRSV-modified live vaccine.

Gamma-tocotrienol attenuates high-fat diet-induced obesity and insulin resistance by inhibiting adipose inflammation and M1 macrophage recruitment

BACKGROUND AND OBJECTIVE

We have previously demonstrated that gamma tocotrienol (γT3) potently inhibits adipocyte hyperplasia in human adipose-derived stem cells (hASCs). In this study, our objective was to investigate the γT3 effects on early-onset obesity, inflammation and insulin resistance in vivo.

METHODS

Young C57BL/6J mice were fed a high-fat (HF) diet supplemented with 0.05% γT3 for 4 weeks. The concentrations of γT3 in plasma and adipose tissue were measured using high-performance liquid chromatography. Effects of γT3 on body weight gain, adipose volume, plasma levels of fasting glucose, insulin (enzyme-linked immunosorbent assay (ELISA)), proinflammatory cytokines (mouse cytokine array), insulin signaling (western blotting) and gene expression (quantitative real-time PCR, qPCR) in the liver and adipose tissue were examined. Influences of γT3 on [3H]-2-deoxyglucose uptake and lipopolysaccharide (LPS)-mediated NFκB signaling (western blotting) were assessed in hASCs. Effects of γT3 on macrophage M1/M2 activation were investigated using qPCR in mouse bone marrow-derived macrophages.

RESULTS

After a 4-week treatment, γT3 accumulated in adipose tissue and reduced HF diet-induced weight gain in epididymal fat, mesenteric fat and the liver. Compared with HF diet-fed mice, HF+γT3-fed mice were associated with (1) decreased plasma levels of fasting glucose, insulin and proinflammatory cytokines, (2) improved glucose tolerance and (3) enhanced insulin signaling in adipose tissue. There were substantial decreases in macrophage specific markers, and monocyte chemoattractant protein-1, indicating that γT3 reduced the recruitment of adipose tissue macrophages (ATMs). In addition, γT3 treatment in human adipocytes resulted in (1) activation of insulin-stimulated glucose uptake and (2) a significant suppression of MAP kinase and NFκB activation. In parallel, γT3 treatment led to a reduction of LPS-mediated M1 macrophage polarization.

CONCLUSION

Our results demonstrated that γT3 ameliorates HF diet-mediated obesity and insulin resistance by inhibiting systemic and adipose inflammation, as well as ATM recruitment.

Combination of muscle tension and crust-freeze-air-chilling improved efficacy of air chilling and quality of broiler fillets

The objective of this study was to evaluate the effects of water immersion chilling (WIC), air chilling (AC), and crust-freeze-air-chilling (CFAC) on the efficacy of broiler chilling and quality of breast fillets with and without muscle tension (MT), restraining both wings behind the carcass. In each of 3 replications, 66 birds were purchased locally and processed at the Michigan State University meat laboratory. After evisceration, one-half of the birds were subjected to MT and the remaining birds received no MT. Twenty-two birds (11 with and 11 without MT) per chilling were randomly assigned to WIC (ice/water slurry at 0.2°C), AC (air at 1°C/1.5 m/s), or CFAC (air at -12°C/1.5 m/s). After chilling and aging for 3 h postmortem (PM), all breast fillets were deboned, one-half of which were immediately quick-frozen or cooked, whereas the remaining half were further aged on ice for 24 h PM. All left fillets were used for pH, R-value, and sarcomere measurements, whereas all right fillets were used for shear force. During chilling, breast temperature was reduced from 40 to 4°C in an average of 62, 68, and 140 min for WIC, CFAC, and AC, respectively. The birds at 3 h PM had higher pH and shear force than those of birds at 24 h PM except the CFAC with no MT (P < 0.05). Breast fillets with MT showed lower shear force than the fillets without MT at 24 h PM (P < 0.05) in AC and CFAC. Based on these findings, the combination of CFAC and MT appears to improve both air chilling efficacy and breast fillet quality.

Cascaded all-optical operations in a hybrid integrated 80-Gb/s logic circuit

We demonstrate logic functionalities in a high-speed all-optical logic circuit based on differential Mach-Zehnder interferometers with semiconductor optical amplifiers as the nonlinear optical elements. The circuit, implemented by hybrid integration of the semiconductor optical amplifiers on a planar lightwave circuit platform fabricated in silica glass, can be flexibly configured to realize a variety of Boolean logic gates. We present both simulations and experimental demonstrations of cascaded all-optical operations for 80-Gb/s on-off keyed data.