2,466 research outputs found
Body composition estimated by bioelectrical impedance analyses is diminished by prenatal stress in neonatal lambs and by heat stress in feedlot wethers
Body composition correlates to carcass value in livestock, which makes the ability to accurately estimate body composition in the live animal beneficial (Berg and Marchello, 1994). Bioelectrical impedance analysis (BIA) is a clinical tool used to assess body composition in humans (Lukaski et al., 1985), but its use in livestock has been minimal. Lean and fat content contribute to profitability for livestock producers, and poor body composition can be caused by stress that occurs either during in utero development (De Blasio et al., 2007) or during postnatal growth (Boyd et al., 2015). Maternal hyperthermia-induced placental insufficiency (Brown et al., 2015) and sustained maternal inflammation (Cadaret et al., 2018) are two established causes of intrauterine growth restriction (IUGR). IUGR-born animals are characterized by asymmetrical growth restriction that alters lifelong body composition due to impaired muscle growth capacity (Yates et al., 2018). In addition, acute heat stress during periods of peak postnatal growth can alter body composition in livestock (Boyd et al., 2015). We postulate that BIA can detect these changes in the live animal. Thus, the objective of this study was to determine whether BIA measurements can predict changes to body composition in live neonatal lambs exposed to intrauterine stress and in heat-stressed feedlot lambs
Deficits in growth, muscle mass, and body composition following placental insufficiency-induced intrauterine growth restriction persisted in lambs at 60 d of age but were improved by daily clenbuterol supplementation
Low birthweight in livestock results from stress-induced intrauterine growth restriction (IUGR; Yates et al., 2018). IUGR fetuses exhibit diminished muscle growth that persists in the neonatal stage, leading to asymmetric body composition and decreased weight gain (Cadaret et al., 2019). Ultimately, low birthweight diminishes yield and carcass merit at harvest (Greenwood et al., 2000), making effective postnatal treatment strategies to improve IUGR growth outcomes necessary. In this study, we examined the benefits of injecting the β2 agonist clenbuterol daily to target adrenergic adaptations that we previously observed in IUGR muscle (Posont et al., 2018; Yates et al., 2018). We hypothesized that IUGRinduced growth deficits would persist at the juvenile stage, manifesting in inferior body composition and carcass traits. We also postulated that clenbuterol would at least partially recover growth and body symmetry. Our objective was to test this hypothesis by assessing growth metrics and body composition in IUGR-born lambs hand-reared to 60 d of age and supplemented daily with injectable clenbuterol
Beef cows with atypical estrous cyclicity at puberty produced calves with deficits in preweaning muscling, metabolic indicators, and myoblast function but not in feedlot performance
In cattle, age at puberty and number of estrous cycles prior to first breeding contribute to lifetime reproductive success (Perry et al., 1991). In our university beef herd, we have identified a subset of cows that exhibited irregular pubertal cyclicity patterns between weaning and their first breeding season, which we postulate is associated with high androstenedione in follicular fluid (Cupp et al., 2019). Cows with high androstenedione are subfertile but wean calves that average 17 kg heavier than the herd average (Summers et al., 2014). We hypothesized that this additional weight at weaning in their offspring is due to superior muscling and growth efficiency, characterized by better myoblast function, lean mass, and metabolic efficiency. The objective of this study was to test this hypothesis by evaluating growth and metabolic parameters in calves prior to weaning and in the feedlot, as well as carcass characteristics at harvest. We compared calves from cows that were classified as having typical pubertal cyclicity, start–stop pubertal cyclicity, or noncyclic puberty
Circulating Thrombospondin-2 enhances prediction of malignant intraductal papillary mucinous neoplasm
Background
IPMNs are cystic pancreatic lesions with variable malignant potential. Thrombospondin-2 (THBS2)—an endogenous, anti-angiogenic matrix glycoprotein—may modulate tumor progression. We hypothesized that circulating levels of THBS2 could aid in preoperative prediction of malignant IPMN.
Methods
Preoperative serum/plasma samples were procured from patients undergoing surgery. Circulating levels of THBS2 were measured (enzyme-linked immunosorbent assay) and compared to surgical pathology IPMN dysplastic grade.
Results
164 patients underwent THBS2 testing (100 Low/Moderate-IPMN; 64 High-Grade/Invasive-IPMN). Circulating THBS2 (mean ± SD) was greater in High-Grade/Invasive-IPMN than Low/Moderate-grade IPMN (26.6 ± 12.7 ng/mL vs. 20.4 ± 8.2 ng/mL; P < 0.001). THBS2 (AUC = 0.65) out-performed CA19-9 (n = 144; AUC = 0.59) in predicting IPMN grade. The combination of THBS2, CA19-9, radiographic main-duct involvement, main-duct diameter, age, sex, and BMI (AUC 0.82; n = 137) provided a good prediction model for IPMN grade.
Conclusion
Circulating THBS2 is correlated with IPMN dysplasia grade. THBS2 alone did not strongly predict IPMN grade but rather strengthened prediction models for High-Grade/Invasive IPMN when combined with other clinical/biomarker data
Circulating Leptin and Branched Chain Amino Acids – Correlation with Intraductal Papillary Mucinous Neoplasm Dysplastic Grade
Background: The most common type of mucinous pancreatic cyst that may progress to pancreatic cancer is intraductal papillary mucinous neoplasm (IPMN). Low-risk IPMN with low-/moderate-grade dysplasia may be safely watched, whereas high-risk IPMN with high-grade dysplasia or invasive components should undergo resection. However, there is currently no reliable means of making this distinction. We hypothesize that blood concentrations of insulin resistance biomarkers may aid in the differentiation of low- and high-risk IPMN.
Methods: Plasma/serum was collected from consented patients undergoing pancreatic resection. IPMN diagnosis and dysplastic grade were confirmed by surgical pathology. The study included 235 IPMN (166 low/moderate grade, 39 high grade, 30 invasive). Circulating levels of leptin, branched chain amino acids (BCAA), and retinol-binding protein-4 (RBP-4) were measured by enzyme-linked immunoassay and correlated with surgical pathology.
Results: Circulating leptin levels (mean ± SE) were significantly higher in patients with low/moderate IPMN than in high-grade/invasive IPMN (15,803 ± 1686 vs. 10,275 ± 1228 pg/ml; p = 0.0086). Leptin levels were positively correlated with BMI (r = 0.65, p < 0.0001) and were higher in females (p < 0.0001). Stratified analysis showed that mean leptin levels were significantly different between low/moderate and high/invasive IPMNs only in females (24,383 ± 2748 vs. 16,295 ± 2040 pg/ml; p = 0.020). Conversely, circulating BCAA levels were lower in low/moderate IPMN than in high-grade/invasive IPMN (0.38 ± 0.007 vs. 0.42 ± 0.01 mM; p = 0.011). No significant differences in RBP-4 levels were observed.
Conclusions: Circulating leptin in females and BCAA correlates with IPMN dysplastic grade and, if combined with clinical characteristics, have the potential to improve clinical decision-making
DNA profile components predict malignant outcomes in select cases of intraductal papillary mucinous neoplasm with negative cytology
Predicting malignancy in intraductal papillary mucinous neoplasm remains challenging. Integrated molecular pathology combines pancreatic fluid DNA and clinical factors into a malignant potential score. We sought to determine the utility of DNA components alone in predicting high-grade dysplasia/invasive disease.
Methods
We reviewed prospectively the records from 1,106 patients with intraductal papillary mucinous neoplasm. We excluded non-intraductal papillary mucinous neoplasm cases and cases with definitive malignant cytology. A total 225 patients had 283 DNA profiles (98 followed by surgery, 185 followed by ≥23-month surveillance). High-grade dysplasia/invasive outcomes were high-grade dysplasia, intraductal papillary mucinous neoplasm-invasive, and adenocarcinoma on surgical pathology or mesenteric or vascular invasion, metastases, or biopsy with high-grade dysplasia or adenocarcinoma during surveillance.
Results
High-quantity DNA predicted (P = .004) high-grade dysplasia/invasive disease outcomes with sensitivity of 78.3%, but 52.7% specificity, indicating benign cases may exhibit high-quantity DNA. High clonality loss of heterozygosity of tumor suppressor genes was 98.0% specific, strongly predicted high-grade dysplasia/invasive disease but lacked sensitivity (20.0%). High-quantity DNA + high clonality loss of heterozygosity had 99.0% specificity for high-grade dysplasia/invasive disease. KRAS mutation alone did not predict high-grade dysplasia/invasive disease, but, when combined with high-quantity DNA (specificity 84.7%) and high clonality loss of heterozygosity (specificity 99.0%) strongly predicted high-grade dysplasia/invasive outcomes.
Conclusion
Certain DNA components are highly specific for high-grade dysplasia/invasive disease and may indicate aggressive lesions, requiring resection when cytology fails
Perturbation evolution with a non-minimally coupled scalar field
We recently proposed a simple dilaton-derived quintessence model in which the
scalar field was non-minimally coupled to cold dark matter, but not to
`visible' matter. Such couplings can be attributed to the dilaton in the low
energy limit of string theory, beyond tree level. In this paper we discuss the
implications of such a model on structure formation, looking at its impact on
matter perturbations and CMB anisotropies. We find that the model only deviates
from CDM and minimally coupled theories at late times, and is well
fitted to current observational data. The signature left by the coupling, when
it breaks degeneracy at late times, presents a valuable opportunity to
constrain non-minimal couplings given the wealth of new observational data
promised in the near future.Comment: Version appearing in Physical Review D. 10 pages, 9 figs. Comparison
with SN1a and projected MAP results, and appendix adde
Pancreatic Fluid Interleukin-1β Complements Prostaglandin E2 and Serum Carbohydrate Antigen 19-9 in Prediction of Intraductal Papillary Mucinous Neoplasm Dysplasia
Objectives:
We sought to determine if interleukin (IL)-1β and prostaglandin E2 (PGE2) (inflammatory mediators in pancreatic fluid) together with serum carbohydrate antigen (CA) 19–9 could better predict intraductal papillary mucinous neoplasm (IPMN) dysplasia than individual biomarkers alone.
Methods:
Pancreatic cyst fluid (n = 92) collected via endoscopy or surgery (2003–2016) was analyzed for PGE2 and IL-1β (Enzyme-Linked Immunosorbent Assay). Patients had surgical pathology-proven IPMN. Threshold values (PGE2 [>1100 pg/mL], IL-1β [>20 pg/mL], serum CA 19–9 [>36 U/mL]) were determined.
Results:
Levels of IL-1β were higher in high-grade (HGD)/Invasive-IPMN (n = 42) compared to Low/Moderate-IPMN (n = 37) (median [range], 54.6 [0–2671] vs 5.9 [0–797] pg/mL; P < 0.001; Area Under Curve [AUC], 0.766). Similarly, PGE2 was higher in HGD/Invasive-IPMN (n = 45) compared to Low/Moderate-IPMN (n = 47) (median [range], 1790 [20–15,180] vs. 140 [10–14,630] pg/mL; P < 0.001; AUC, 0.748). Presence of elevated PGE2 and IL-1β (AUC, 0.789) provided 89% specificity and 82% positive predictive value (PPV) for HGD/Invasive-IPMN. Elevated levels of all three provided 100% Specificity and PPV for HGD/Invasive-IPMN.
Conclusion:
Cyst fluid PGE2, IL-1β, and serum CA 19–9 in combination optimize specificity and PPV for HGD/Invasive-IPMN and may help build a panel of markers to predict IPMN dysplasia
Heat stress and β-adrenergic agonists alter the adipose transcriptome and fatty acid mobilization in ruminant livestock
Growth and feed efficiency of cattle are improved by supplementation with the beta-adrenergic agonists (βAA), ractopamine hydrochloride (RH; β1AA) or zilpaterol hydrochloride (ZH; β2AA) (Elam et al., 2009). βAA supplementation alters adipose deposition by inhibiting fatty acid biosynthesis and promoting lipolysis of stored triacylglycerols into free fatty acids (FFAs) (Johnson et al., 2014). However, β2 adrenoceptors (βAR) desensitize with chronic activation (Re et al., 1997); supplementation is thus limited to the last 20 to 40 d of feeding.
The annual economic impact of heat stress (HS) has been estimated to exceed $2.4 billion (St-Pierre et al., 2003). Heat-stressed livestock have reduced growth rates, dry matter intake, and average daily gain (Mitlöhner et al., 2001; St-Pierre et al., 2003). In response to acute stress, signaling pathways for lipolysis of circulating and stored triglycerides are activated, while chronic stress increases lipogenesis and adipogenesis (Campbell et al., 2009; Peckett et al., 2011). In cattle, HS also increases the responsiveness of adipocytes to lipolytic signals, increasing lipolysis (Faylon et al., 2015).
The objective of this study was to understand how HS and βAA independently and interactively affect adipose tissue. Prior work identified minimal impact of RH on metabolic properties (Barnes et al., 2019) and on the transcriptome of skeletal muscle (Kubik et al., 2018). We therefore hypothesized that RH may be primarily affecting adipose; specifically, that lipolytic activity is increased due to heat and βAA in an additive fashion. We tested this hypothesis in RH-supplemented lambs and ZH-supplemented cattle exposed to HS for 30 and 21 d, respectively
- …