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Heat stress (HS) may result in changes in the behavior, endocrine system, and physiological characteristics of dairy cows, and it may even lead to death in severe cases. As the effects of global warming have become more notable, the prevalence of HS has increased among dairy cows. Therefore, comprehensive strategies, including not only cooling measures but also dietary adjustments and genetic improvements for heat tolerance, are required to help these animals regulate their body temperature and avoid HS. In addition, detecting HS signs is essential for both lactating and dry cows to ensure appropriate interventions. The temperature-humidity index (THI) is a widely used tool for evaluating the effects of HS on livestock. Since the physiological state of cattle significantly influences their responses to HS, it is imperative to establish specific THI thresholds for both lactating and dry cows to implement appropriate cooling regimens and optimize animal welfare. In this study, we used the THI to investigate the relationship between rectal temperature (RT), respiration rate (RR), and sweating rate (SR) in lactating and dry cows. We also explored the relationships between milk yield at different lactation stages and THI thresholds. The results indicated that lactating and dry cows had different THI thresholds based on their immediate physiological responses. Compared with lactating cows, dry cows had higher THI thresholds for RT, RR, and SR. In addition, cows in early-, intermediate-, and late-lactation stages under thermoneutral conditions produced significantly more milk than did those under mild, moderate, and severe HS conditions, indicating that milk yield losses occur under HS conditions. Taken together, these findings provide valuable insights into how HS can be mitigated in subtropical dairy farms. For lactating cows, implementing cooling measures is recommended when the THI reaches 66 to 67, whereas for dry cows, waiting until the THI reaches 73 is recommended. Milk yield losses may occur when lactating cows are under HS conditions. Therefore, appropriate cooling measures should be implemented at accurate THI thresholds to ensure optimal animal welfare for both lactating and dry cows., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Aims: Patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF) accompanied by significant mitral regurgitation (MR) had poor outcome. Several vasodilator trials showed neutral results. We aimed to investigate the effect of early up-titration of hydralazine combined with conventional treatment in acute HF with severe systolic dysfunction and significant MR., Methods and Results: The study was open-labelled, one-to-one ratio randomized designed. Consecutively hospitalized patients with decompensated HF symptoms, LVEF < 35%, and MR more than moderate severity were enrolled after exclusion. All participants with inadequate preload should have intake promotion with/without fluid supply. Patients receiving evidence-based medications (EBMs) as conventional treatment served as the control. Hydralazine + conventional treatment group received up-titration of hydralazine at Days 1-5 of the index admission combined with EBMs and throughout the course of follow-up. The endpoints included cardiovascular (CV) death and HF rehospitalization. Totally, 408 patients were enrolled (203 in conventional treatment and 205 in hydralazine + conventional treatment). The mean follow-up period was 3.5 years. The mean dose of hydralazine was 191 mg at index admission and 264 mg at study end in hydralazine + conventional treatment group. Both groups did not significantly differ in prescription rates and dosages of EBMs (all P > 0.05) at study end. Side effects did not differ between the two groups. Finally, 51% (104 out of 203 cases) reached endpoints in conventional group and 34.6% (71 out of 205 cases) in hydralazine + conventional treatment group, which had a significant reduction in CV events (hazard ratio 0.613, 95% confidence interval 0.427-0.877, P < 0.001). In-hospital death during the index admission was significantly higher in conventional group (5.4% vs. 0.5%, respectively; P = 0.001)., Conclusions: When administered without inadequate preload, combining early up-titration of hydralazine with EBMs improves outcome in patients with severe systolic dysfunction and significant MR, and it is safe and well tolerated., (© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Background: The efficacy of the left atrial (LA) expansion index (LAEI) to predict cerebral ischemic events in patients with atrial fibrillation (AF) is unknown., Methods: We enrolled 177 patients with AF (88 with paroxysmal AF and 89 with persistent AF) and a baseline CHA 2 DS 2 -VASc score (at enrollment) of 3.6 ± 2.3. Comprehensive echocardiography was performed at enrollment. The LAEI was calculated as (Vol max - Vol min ) × 100%/Vol min , where Vol max and Vol min denoted maximal and minimal LA volumes, respectively. The study endpoint was ischemic stroke. Stroke subtypes were classified into cardioembolic stroke (CE), non-CE with determined mechanism (NCE), embolic stroke of undetermined source (ESUS), or transient ischemic attack (TIA)., Results: Over a mean 9.9-year follow-up period, 44 (24.9%) of the patients reached the endpoint (24 with CE, 4 with NCE, 6 with ESUS, and 10 with TIA). The LAEI was lower in the stroke group than in the non-stroke group. Stroke incidence in the lowest LAEI quartile was much higher than that in the other LAEI quartiles; the 10-year cumulative stroke risk was 15.9% (14/88) and 33.7% (30/89) in the patients with paroxysmal and persistent AF, respectively. An LAEI of < 35% predicted the presence of stroke with 77% sensitivity and 78% specificity. In multivariable analysis, the LAEI was independently associated with ischemic stroke (hazard ratio 0.952 per 1% increase, 95% confidence interval 0.932-0.971, p < 0.0001)., Conclusions: The LAEI is a useful predictor of ischemic stroke in patients with AF., Competing Interests: All the authors declare no conflict of interest.

Higher average daily gain, more lean meat yield and less fat yield of porcine carcass increase selling profits for animal producers. Myostatin (MSTN), previously called GDF8, is a member of transforming growth factor-β (TGF-β) superfamily. It is a negative regulator for both embryonic development and adult homeostasis of skeletal muscle. In this study, the genotypes of the previously described SNPs MSTN g.435G>A and g.447A>G SNPs in 66 Duroc pigs, 33 Landrace pigs, 180 Duroc × Landrace (DL) pigs and 155 Duroc × Yorkshire × Landrace (DYL) pigs were determined by Taqman SNP Genotyping Assays. For Duroc and Landrace pigs, MSTN g.435GG/g.447AA individual had greater backfat thickness (p < 0.05) than g.435AA/g.447GG individual, whereas MSTN g.435AA/g.447GG had greater meat (p < 0.05) and meat percentage (p < 0.05) than g.435GA/g.447AG individual. For DL and DYL pigs, the MSTN g.435GG/g.447AA animals were greater in backfat at ultrasound 10th rib (p < 0.05) and carcass 10th rib (p < 0.01) than g.435AA/g.447GG individual. The MSTN g.435AA/g.447GG individual also had higher values than g.435GG/g.447AA for anterior-end meat (p < 0.05), posterior-end meat (p < 0.01), total meat weight (p < 0.01) and meat percentage (p < 0.01). This study confirmed evidence that MSTN g.435G>A and g.447A>G affected carcass traits in pigs. The effects of the mutated alleles were additive with the maximal effects resulting from two copies of the mutated allele. Selection for MSTN g.435A/g.447G allele is expected to increase muscle of limb and total meat production and decrease backfat thickness., (© 2013 Blackwell Verlag GmbH.)

Average daily gain (ADG) and feed efficiency (FE) are important factors for assessing productivity in farm animals. Myostatin (MSTN), previously called GDF8, is a member of transforming growth factor β (TGFβ) superfamily. It is a negative regulator for both embryonic development and adult homeostasis of skeletal muscle. In this study, the genotypes of MSTN g.435G > A and g.447A > G SNPs in Duroc pigs were determined. The 435GG/447AA individually had significantly higher ADG (P < 0.01), body weight at 70 d (P < 0.05) and 150 d (P < 0.01), and a lower age at 110 kg (P < 0.01) than 435AA/447GG individuals. Dose dependent genetic additive effects were found for the negative effects of the 435A/447 G allele for ADG and body weight on 70 d and 150 d. The 435A/447 G allele also increased the age at 110 kg about 1.47 and 4.53% for 1 and 2 copies, respectively. The MSTN 435 G/447A allele increased the age at 110 kg about 1.41 and 4.47% for 1 and 2 copies, respectively. Overall, the two mutated MSTN 435A/447G allele had negative effects on ADG (P < 0.01), body weight at 70 d (P < 0.05), and 150 d (P < 0.001) and increased the age at 110 kg (P < 0.001). The present study provided evidence that MSTN g.435G > A and g.447A > G affected growth in Duroc pigs. The effects of the mutated alleles were additive with the maximal effects resulting from two copies of the wild-type allele. Selection for the 435 G/447A allele is expected to increase ADG, body weight and decrease the age at 110 kg in Duroc pigs and might be used in porcine breeding programs.

The objective of this study was to establish the long-term in vitro culture system for chicken gonadal primordial germ cells (gPGCs). Primitive gonads collected from 5.5-day-old chicken embryos were dissociated and explanted onto plates pre-coated with 0.1% gelatin. Each of the four different conditioned media from proliferating and mitotically inactivated chicken embryonic fibroblast (CEF) cells and murine embryonic fibroblasts (STO cells, CRL-1053, ATCC, USA), respectively, was supplemented with growth factors and used to support the growth of gPGCs. The result showed that all the conditioned media could promote the growth and colony formation of gPGCs in vitro, in particular the medium conditioned by inactivated CEF cells. The gPGC-derived colonies maintained in inactivated CEF cells-conditioned medium up to 281 days were positively stained by periodic acid Schiff reaction and antibodies specific to anti-SSEA-1, SSEA-3, SSEA-4, integrin alpha6 and integrin beta1. Their capacities of migration via vascular system and taking up residence in the primary gonadal ridge were further demonstrated by transferring to the dorsal aorta of stage 17 recipient embryos. These results suggested that our culture system is able to maintain chicken gPGCs for long-term in vitro culture without losing their capacity to express pluripotent markers and to integrate into the gonads.

Mammalian embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass (ICM) of the blastocyst. These cells are able to proliferate continuously without differentiation in vitro under suitable conditions. Their capacity of pluripotency in differentiation will be resumed when they are reintroduced into host embryos, when they will contribute to the embryonic development to form chimeric individuals. Manipulation of ES cells has been mainly established from studies in the mouse, and is powerful in the production of transgenic animals. Porcine ICM-derived cell lines possess the same cellular morphology and in vitro behavior as those of murine ES cells, but have lower efficiency in chimera formation when reintroduced into host embryos. This study was to determine the influences of passage number and the duration of in vitro culture on the capacity of porcine ICM-derived cells in the generation of chimeric embryos. The results showed that when passage number of porcine ICM-derived cells was less than 15, there were no detrimental effects on its integration ability. Extending the culture time up to 6 days in each passage of porcine ICM-derived cells impaired its integration capacity into the host blastocyst. Porcine ICM-derived cells cultured for more than 4 days in each passage should not be used for blastocyst injection if high efficiency of chimera production is to be achieved.

The activation procedure used in nuclear transfer (NT) is one of the critical factors affecting the efficiency of animal cloning. The purpose of this study was to compare the effect of two electrical field strengths (EFS) for activation on the developmental competence of caprine NT embryos reconstructed from ear skin fibroblasts of adult Alpine does. The NT embryos were obtained by transfer of the quiescent fibroblasts at the fourth passage into the enucleated metaphase II (M II) oocytes. Four to five hours after electrical fusion, the NT-embryos were activated by EFS either at 1.67 or at 2.33 kV/cm and immediately incubated in 6-DMAP (2 mM) for 4 h. The cleavage rate of the NT-embryos activated with 2.33 kV/cm was greater than that activated with 1.67 kV/cm after in vitro culture for 18 h (65.6% versus 19.6%, p < 0.001). No pregnancy was found in 14 recipient does after transferring 51 NT embryos at 1-2 cell stages activated with 1.67 kV/cm. In contrast, two of the seven recipients were pregnant and gave birth to three kids after transferring 61 NT embryos at 1-2 cell stages activated by 2.33 kV/cm. The birth weights of three cloned kids were within the normal range of Alpine goats. However, one kid died 1h after birth while the remaining two are still healthy. DNA analysis by polymerase chain reaction (single-strand conformation polymorphism, SSCP) confirmed that the three kids were genetically identical to the nuclear donor.

A recombinant plasmid, which contains the Pseudomonas aeruginosa exotoxin A (PE) gene with a C-terminal deletion, was inserted into expression vector pSecTag Xpress. The expression of this bacterial exotoxin in an animal cell was first demonstrated in 3T3 cell by transient transfection and western blot assay. Recombinant plasmid DNA was then injected intramuscularly to BALB/c mice, anti-PE specific antibodies were found in all animals vaccinated with plasmid containing the PE gene and with 'detoxicated' recombinant PE protein. Mice vaccinated with DNA were protected from the intoxication of lethal dosage of P. aeruginosa exotoxin A. Our results indicated that mice vaccinated with DNA encoding the PE gene could express PE protein in vivo, induced specific immune response, and provided sufficient protective immunity that safeguarded mice from the injection of lethal dosage of PE toxin.