Effects of fat source in calf starter on growth performance, blood fatty acid profiles, and inflammatory markers during cold season.

This study was conducted to investigate the effects of supplementation of different fat sources in calf starters on growth performance, health, blood fatty acid profiles, and inflammatory markers during the cold season in dairy calves. A total of 48 Holstein calves (24 males and 24 females) were randomly assigned to 1 of 4 starter diets throughout the experiment (d 3 to 65): (1) no supplemented fat (CON), (2) 3% calcium-salts of soybean oil (Ca-SBO), (3) 3% calcium-salts of fish oil (Ca-FO), and (4) 3% mixture of Ca-SBO and Ca-FO (1.5% each, DM basis; MIX). Calves were given free access to starter feed and water and were raised individually in pens from 3 to 65 d of age. Calves fed Ca-SBO consumed a greater proportion of n-6 FA, while calves fed Ca-FO consumed a greater level of n-3 FA compared to the other dietary treatments. Fat supplementation increased the intake of linoleic acid, the major n-6 FA, with the greater intake observed in the Ca-SBO group compared to the other dietary treatments. Calves fed the Ca-FO and MIX diets consumed more long-chain n-3 FA than the other diets. In addition, calves fed Ca-SBO and Ca-FO diets consumed more starter feed and total dry matter than calves fed MIX and CON throughout the experiment (d 3 to 65). Calves fed Ca-FO had higher average daily gain throughout the trial (d 3 to 65) than the other treatment groups. Of all treatment groups, calves fed Ca-FO achieved the highest final body weight and showed the greatest feed efficiency. Random forest analysis revealed that eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid were the serum levels of FA most affected by the diets. The principal component analysis of blood FA profile, blood parameters, and inflammatory markers showed distinct differences between dietary treatments. Calves fed Ca-SBO had higher plasma concentrations of linoleic acid, while calves fed Ca-FO had higher plasma concentrations of long-chain n-3 polyunsaturated fatty acids (PUFA), such as EPA, docosapentaenoic acid (DPA), and DHA than the other treatment groups. Plasma inflammatory markers were lower in calves fed Ca-FO and higher in calves fed CON than in the other treatment groups. The Ca-FO group had lower levels of inflammatory markers, including serum amyloid A, tumor necrosis factor-alpha, Interferon-γ, haptoglobin, and interleukin-6 compared to the other experimental treatments. Also, the blood malondialdehyde levels, an indicator of oxidative stress, were lower in calves fed Ca-FO compared with calves fed the other treatment diets. In conclusion, the performance of preweaned dairy calves can be improved by adding fat to their starter feed under cold conditions. Overall, the type of fat in milk may affect growth and inflammation of dairy calves before weaning under cold conditions, with n-3 FA (Ca-FO) promoting growth and reducing inflammation more effectively than n-6 FA (Ca-SBO).

Comprehensive review of resveratrol as a feed additive in dairy cows: exploring its potential diverse effects and implications.

Heat stress and growing demand for dairy products in tropical regions exert metabolic pressure on dairy cows, leading to metabolic diseases and economic losses. Resveratrol (RSV) is known for its numerous beneficial health effects and can be used as a barrier against metabolic abnormalities and prevent economic losses. Several studies have investigated the effects of RSV in humans and various animal species. In this review, we attempted to investigate the effects of RSV from different aspects so that we could have a practical proposal for its utilization in dairy cows. RSV was found to have potential antioxidant, anti-inflammatory, anti-obesity, and antimicrobial effects, leading to improved reproductive performance. It is interesting that the effect of RSV on the microbial population leads to a significant decrease in methane emissions. However, high doses of RSV have been associated with possible adverse effects, underscoring the dose dependence of its efficacy. In conclusion, RSV polyphenol at optimal doses is a promising agent for the prevention and treatment of metabolic abnormalities in dairy cows, based on our literature review and study results.

Invited review: Muscle protein breakdown and its assessment in periparturient dairy cows.

Mobilization of body reserves including fat, protein, and glycogen is necessary to overcome phases of negative nutrient balance typical for high-yielding dairy cows during the periparturient period. Skeletal muscle, the largest internal organ in mammals, plays a crucial role in maintaining metabolic homeostasis. However, unlike in liver and adipose tissue, the metabolic and regulatory role of skeletal muscle in the adaptation of dairy cows to the physiological needs of pregnancy and lactation has not been studied extensively. The functional integrity and quality of skeletal muscle are maintained through a constant turnover of protein, resulting from both protein breakdown and protein synthesis. Thus, muscle protein breakdown (MPB) and synthesis are intimately connected and tightly controlled to ensure proper protein homeostasis. Understanding the regulation of MPB, the catabolic component of muscle turnover, and its assessment are therefore important considerations to provide information about the timing and extent of tissue mobilization in periparturient dairy cows. Based on animal models and human studies, it is now evident that MPB occurs via the integration of 3 main systems: autophagy-lysosomal, calpain Ca2+-dependent cysteine proteases, and the ubiquitin-proteasome system. These 3 main systems are interconnected and do not work separately, and the regulation is complex. The ubiquitin-proteasomal system is the most well-known cellular proteolytic system and plays a fundamental role in muscle physiology. Complete degradation of a protein often requires a combination of the systems, depending on the physiological situation. Determination of MPB in dairy cows is technically challenging, resulting in a relative dearth of information. The methods for assessing MPB can be divided into either direct or indirect measurements, both having their strengths and limitations. Available information on the direct measures of MPB primarily comes from stable isotopic tracer methods and those of indirect measurements from assessing expression and activity measures of the components of the 3 MPB systems in muscle biopsy samples. Other indirect approaches (i.e., potential indicators of MPB), including ultrasound imaging and measuring metabolites from muscle degradation (i.e., 3-methylhistidine and creatinine), seem to be applicable methods and can provide useful information about the extent and timing of MPB. This review presents our current understanding, including methodological considerations, of the process of MPB in periparturient dairy cows.

Blood and adipose tissue steroid metabolomics and mRNA expression of steroidogenic enzymes in periparturient dairy cows differing in body condition.

In high-yielding dairy cows, the rapidly increasing milk production after parturition can result in a negative nutrient balance, since feed intake is insufficient to cover the needs for lactation. Mobilizing body reserves, mainly adipose tissue (AT), might affect steroid metabolism. We hypothesized, that cows differing in the extent of periparturient lipomobilization, will have divergent steroid profiles measured in serum and subcutaneous (sc)AT by a targeted metabolomics approach and steroidogenic enzyme profiles in scAT and liver. Fifteen weeks antepartum, 38 multiparous Holstein cows were allocated to a high (HBCS) or normal body condition (NBCS) group fed differently until week 7 antepartum to either increase (HBCS BCS: 3.8 ± 0.1 and BFT: 2.0 ± 0.1 cm; mean ± SEM) or maintain BCS (NBCS BCS: 3.0 ± 0.1 and BFT: 0.9 ± 0.1 cm). Blood samples, liver, and scAT biopsies were collected at week -7, 1, 3, and 12 relative to parturition. Greater serum concentrations of progesterone, androsterone, and aldosterone in HBCS compared to NBCS cows after parturition, might be attributed to the increased mobilization of AT. Greater glucocorticoid concentrations in scAT after parturition in NBCS cows might either influence local lipogenesis by differentiation of preadipocytes into mature adipocytes and/or inflammatory response.

Expression of specific signaling components related to muscle protein turnover and of branched-chain amino acid catabolic enzymes in muscle and adipose tissue of preterm and term calves.

Postnatal metabolism depends on maturation of key metabolic pathways around birth. In this regard, endogenous glucose production is impaired in calves born preterm. Concerning protein metabolism, the rates of protein turnover are greater during the neonatal period than at any other period of postnatal life. The mammalian target of rapamycin (mTOR) and the ubiquitin-proteasome system (UPS) are considered as the major regulators of cellular protein turnover. The objectives of this study were to investigate (1) the changes in plasma AA profiles, (2) the mRNA abundance of mTOR signaling and UPS-related genes in skeletal muscle, and (3) the mRNA abundance of branched-chain AA (BCAA) catabolic enzymes in skeletal muscle and adipose tissue in neonatal calves with different degree of maturation during the transition to extrauterine life. Calves (n = 7/treatment) were born either preterm (PT; delivered by cesarean section 9 d before term) or at term (T; spontaneous vaginal delivery) and were left unfed for 1 d. Calves in treatment TC were also spontaneously born but were fed colostrum and transition milk for 4 d. Blood samples were collected from all calves at birth and at 24 h of life. Additional blood samples were taken 2 h after feeding (26 h of life) for PT and T calves, and on d 4 of life for TC, to determine plasma glucose, urea, and AA. Tissue samples from 3 muscles [M. longissimus dorsi (MLD), M. semitendinosus (MST), and M. masseter (MM)], and kidney fat were collected following euthanasia at 26 h after birth (PT, T) or on d 4 of life (TC) at 2 h after feeding. The concentrations of the majority of plasma AA (Ala, Gln, Asn, Cit, Lys, Orn, Thr, and Tyr), nonessential AA, and total AA were greater during the first 24 h and also before and 2 h after feeding in PT than in T. The ratio of plasma BCAA to the aromatic AA (Tyr and Phe) was greatest in TC, followed by T, and least in PT. The mRNA abundance of mTOR and ribosomal protein S6 kinase 1 (S6K1) in MLD and MM was greater in PT and T than in TC. The mRNA abundance of muscle-specific ligases FBXO32 (F-box only protein 32) in the 3 different skeletal muscles and TRIM63 (tripartite motif containing 63) in MLD was greater in PT and T than in TC; in MM, TRIM63 mRNA was greatest in PT. The mRNA for BCKDHA and BCKDHB (the α and ß polypeptide of branched-chain α-keto acid dehydrogenase) in kidney fat was elevated in PT and T compared with TC, suggesting a possible enhancement of BCAA oxidation as energy source to cover the energetic and nutritional postnatal demands in PT and T in a starved state. The increased abundances of mTOR-associated signaling factors and muscle-specific ligase mRNA indicate a greater rate of protein turnover in muscles of PT and T in a starved state. Elevated plasma concentrations of several AA may result from enhanced muscle proteolysis and impaired conversion to glucose in the liver of PT calves.

Soybean oil supplementation and starter protein content: Effects on growth performance, digestibility, ruminal fermentation, and urinary purine derivatives of Holstein dairy calves.

This study investigated the effects of feeding dairy calves starter diets containing 19% or 22% crude protein (CP) content on a dry matter basis and either supplemented or not with soybean oil (SBO, 0 vs. 3%, dry matter basis) on growth performance, digestibility, urinary nitrogen, and purine derivatives (PD) excretion. A total of 48 female Holstein dairy calves (mean 39.8 kg of body weight) were randomly distributed to experimental diets in a 2 × 2 factorial arrangement of treatments. The 4 dietary treatments were (1) starter diet without SBO supplement and 19% CP (NSBO-19CP), (2) starter diet without SBO supplement and 22% CP (NSBO-22CP), (3) starter diet with 3% SBO and 19% CP (SBO-19CP), and (4) starter diet with 3% SBO and 22% CP (SBO-22CP). Milk feeding value was similarly based on a constant protocol across experimental treatments and calves had ad libitum access to water and starter diets throughout the study. All calves were weaned on d 63 of age and remained in the study until d 83 of age. Calves supplemented with SBO had lower starter feed intake and average daily gain (ADG) and lower feed efficiency (FE) but had a higher fecal score indicating a higher likelihood of diarrhea occurrence compared with unsupplemented calves. Wither heights, digestibilities of organic matter, CP, and neutral detergent fiber were decreased, and ruminal volatile fatty acids tended to be reduced, and the molar proportion of ruminal butyrate (preweaning) and acetate (postweaning) reduced by supplemental SBO. The urinary allantoin and total PD excretion were reduced; however, urinary nitrogen excretion was increased when calves were supplemented with SBO. The CP amount did not affect starter feed intake, FE, or diarrhea occurrence rate, whereas the 22CP diets increased neutral detergent fiber digestibility, improved ADG (tendency), and increased allantoin and urinary PD excretion compared with the 19CP diets. The starter feed intake, ADG, FE, diarrhea occurrence rate, nutrient digestibility, and ruminal fermentation were not affected by the interaction between starter SBO and CP level; however, hip height and total PD in calves that received the SBO-22CP diets were higher than those fed the SBO-19CP diets. In conclusion, based on our experimental conditions, supplemental SBO could not be recommended for dairy calves. Furthermore, our findings indicate that SBO has negative effects on performance more attributed to reducing starter intake, digestibility, and ruminal volatile fatty acid concentration rather than because of a limitation of starter metabolizable protein supply and intestinal amino acid availability. Therefore, our results indicate that feeding the higher starter CP content is not a viable strategy to compensate for the negative effects of SBO supplementation on the growth performance of dairy calves.

Proteasome activity and expression of mammalian target of rapamycin signaling factors in skeletal muscle of dairy cows supplemented with conjugated linoleic acids during early lactation.

The mammalian target of rapamycin (mTOR) is a major regulator of protein synthesis via its main downstream effectors, ribosomal protein S6 kinase (S6K1) and eukaryotic initiation factor 4E binding protein (4EBP1). The ubiquitin-proteasome system (UPS) is the main proteolytic pathway in muscle, and the muscle-specific ligases tripartite motif containing 63 (TRIM63; also called muscle-specific ring-finger protein 1, MuRF-1) and F-box only protein 32 (FBXO32; also called atrogin-1) are important components of the UPS. We investigated 20S proteasome activity and mRNA expression of key components of mTOR signaling and UPS in skeletal muscle of dairy cows during late gestation and early lactation and tested the effects of dietary supplementation (from d 1 in milk) with conjugated linoleic acids (sCLA; 100 g/d; n = 11) compared with control fat-supplemented cows (CTR; n = 10). Blood and muscle tissue (semitendinosus) samples were collected on d -21, 1, 21, and 70 relative to parturition. Dry matter intake increased with time of lactation in both groups. It was lower in sCLA than in CTR on d 21, which resulted in a reduced calculated metabolizable protein balance. Most serum and muscle concentrations of AA followed time-related changes but were unaffected by CLA supplementation. In both groups, serum and muscle 3-methylhistidine (3-MH) concentrations and the ratio of 3-MH:creatinine increased from d -21 to d 1, followed by a decline on d 21. The mRNA abundance of MTOR on d 21 and 70 was greater in sCLA than in CTR. The abundance of 4EBP1 mRNA did not differ between groups but was upregulated in both on d 1. The mRNA abundance of S6K1 on d 70 was greater in CTR than in sCLA, but remained unchanged over time in both groups. The mRNA abundance of FBXO32 (encoding atrogin-1) on d 21 was greater in sCLA than in CTR. The mRNA abundance of TRIM63 (also known as MuRF1) showed a similar pattern as FBXO32 in both groups: an increase from d -21 to d 1, followed by a decline. The mRNA for the α (BCKDHA) and ß (BCKDHB) polypeptide of branched-chain α-keto acid dehydrogenase was elevated in sCLA and CTR cows on d 21, respectively, suggesting a role of CLA in determining the metabolic fate of branched-chain AA. For the mTOR protein, no group differences were observed. The abundance of S6K1 protein was greater across all time points in sCLA versus CTR. The antepartum 20S proteasome activity in muscle was elevated in both groups compared with postpartum, probably reflecting the start of protein mobilization before parturition. Plasma insulin concentrations decreased in both groups postpartum but to a greater extent in CTR than in sCLA, resulting in greater insulin concentrations in sCLA than in CTR. Thus, the greater abundance of MTOR mRNA and S6K1 protein in sCLA compared with CTR might be mediated by the greater plasma insulin postpartum. The upregulation of MTOR mRNA in sCLA cows on d 21, despite greater FBXO32 mRNA abundance, may reflect a simultaneous activation of both anabolic and catabolic signaling pathways, likely resulting in greater protein turnover.

Effect of chromium supplementation on growth performance, meal pattern, metabolic and antioxidant status and insulin sensitivity of summer-exposed weaned dairy calves.

Stressful situations may result in serum chromium (Cr) depletion with increased urinary excretion of the mineral and increased Cr requirements. The objective of this study was to investigate the effects of Cr supplementation on growth performance, feeding behavior, blood metabolites and hormones, indicators of oxidative stress and glucose-insulin kinetics of summer-exposed weaned dairy calves. In total, 48 Holstein female calves (63 days of age; 77.0±1.45 kg of BW) were assigned randomly to one of two treatments: (1) a control group with no supplemental Cr (Cr-), and (2) a supplemental Cr group (Cr+) to supply 0.05 mg Cr as Cr-methionine/kg of BW0.75. Chromium was provided in the starter feed and adjusted weekly based on BW over the experimental period. All calves were on experiment for 4 weeks after weaning. The average maximum temperature-humidity index was 76.1 units during the study period, indicating a mild degree of environmental heat load. Results indicated that in summer-exposed dairy calves, increased dietary Cr provision tended to decrease fecal score, tended to change rumination pattern, increased antioxidant capacity by increasing serum concentration of catalase, but had no effects on growth performance, metabolic status or peripheral glucose and insulin metabolism.

Displacement Forces in Stent Grafts: Influence of Diameter Variation and Curvature Asymmetry.

OBJECTIVES: Long-term durability after endovascular aortic repair is influenced by stent graft migration causing types I and III endoleaks. Flow induced displacement forces have been shown to have the potential to cause migration. In this study, the influence of the distal diameter of iliac limb stent grafts and the shape of graft curvature on flow induced displacement forces, were investigated. METHODS: In an experimental pulsatile flow model mimicking aortic conditions in vivo, flow induced displacement forces at the proximal and distal ends of iliac limb stent grafts were studied at different angles (0-90°) and perfusion pressures (145/80, 170/90, 195/100 mmHg). Bell-bottomed, tapered, and non-tapered stent grafts and also asymmetric stent graft curvatures at 90° bend were studied. Measurements of graft movement were performed at all studied angulations and graft shapes. RESULTS: For all stent graft diameters, flow induced displacement forces increased with higher pressure and increased stent graft angulation. Forces in the bell-bottom graft were considerably higher than in tapered and non-tapered grafts, with a markedly elevated peak force at the distal end (proximal end, 2.3 ± 0.06 N and distal end, 6.9 ± 0.05 N compared with 1.7 ± 0.08 N and 1.6 ± 0.08 N in non-tapered grafts; p < .001 both). Peak forces in tapered and non-tapered grafts were not significantly different between the proximal and distal end. In asymmetric stent graft curvatures, a significant increase in displacement forces was observed in the attachment zone that was closest to the stent graft bend. Graft movement increased with greater displacement forces. CONCLUSION: Flow induced displacement forces in iliac limb stent grafts are significant and are influenced by distal stent graft diameter and the shape of the graft curvature. The displacement forces are particularly high at the large distal end of bell-bottom grafts. Wide iliac arteries treated with bell-bottom stent grafts may require more vigilant surveillance and improved stent graft fixation.

Is cell viability always directly related to corrosion resistance of stainless steels?

It has been frequently reported that cell viability on stainless steels is improved by increasing their corrosion resistance. The question that arises is whether human cell viability is always directly related to corrosion resistance in these biostable alloys. In this work, the microstructure and in vitro corrosion behavior of a new class of medical-grade stainless steels were correlated with adult human mesenchymal stem cell viability. The samples were produced by a powder metallurgy route, consisting of mechanical alloying and liquid-phase sintering with a sintering aid of a eutectic Mn-Si alloy at 1050 °C for 30 and 60 min, leading to nanostructures. In accordance with transmission electron microscopic studies, the additive particles for the sintering time of 30 min were not completely melted. Electrochemical impedance spectroscopic experiments suggested the higher corrosion resistance for the sample sintered for 60 min; however, a better cell viability on the surface of the less corrosion-resistant sample was unexpectedly found. This behavior is explained by considering the higher ion release rate of the Mn-Si additive material, as preferred sites to corrosion attack based on scanning electron microscopic observations, which is advantageous to the cells in vitro. In conclusion, cell viability is not always directly related to corrosion resistance in stainless steels. Typically, the introduction of biodegradable and biocompatible phases to biostable alloys, which are conventionally anticipated to be corrosion-resistant, can be advantageous to human cell responses similar to biodegradable metals.

Effect of treating alfalfa silage with pistachio by-products extract on Saanen dairy goats performance and microbial nitrogen synthesis.

A lactation experiment was conducted to determine the influence of addition of pistachio by-products extract (PBE) to alfalfa silage (AS) on performance, rumen fermentation, milk yield and composition, and microbial nitrogen synthesis. Eight multiparous dairy goats (1.8 ± 0.25 kg of milk yield) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments to compare two types of AS (supplemented with or without PBE) with two levels of dietary crude protein (14% vs. 16% CP). Dietary treatments were (i) AS with 14% CP of DM diet without PBE (14%CP-PBE), (ii) AS with 14% CP of DM diet with PBE (14%CP + PBE), (iii) AS with 16% CP of DM diet without PBE (16%CP-PBE) and (iv) AS with 16% CP of DM diet with PBE (16%CP + PBE). PBE was sprayed on fresh alfalfa at a ratio of 500 ml/kg alfalfa DM to get the final concentration of 1% tannin as tannic acid equivalent on DM basis. Intake of CP was greater (p < 0.01) in goats fed 16% CP diets than those fed 14% CP diets, regardless of PBE supplementation. Supplementation of PBE tended to decrease (p = 0.09) rumen NH3 -N concentration regardless of the level of CP in the diet. Supplementation of PBE tended (p = 0.09) to decrease total purine derivatives regardless of the level of CP in the diet with no significant change in microbial nitrogen supply. Efficiency of microbial nitrogen synthesis (EMNS) had a tendency (p = 0.07) to decrease in PBE supplemented diets. There was also a tendency (p = 0.10) for more EMNS in 14% CP fed goats than those fed 16% CP diets. Therefore, AS supplemented with PBE may lead to less concentration of ruminal NH3 -N because of decreased degradation of CP by rumen micro-organisms in response to pistachio by-products tannins.

Ellagic acid protects against arsenic toxicity in isolated rat mitochondria possibly through the maintaining of complex II.

Chronic arsenic exposure has been linked to many health problems including diabetes and cancer. In the present study, we assessed the protective effect of ellagic acid (EA) against toxicity induced by arsenic in isolated rat liver mitochondria. Reactive oxygen species (ROS) and mitochondrial membrane potential decline were assayed using dichlorofluorescein diacetate and rhodamine 123, respectively, and dehydrogenase activity obtained by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide conversion assay. Arsenic increased ROS levels and mitochondrial dysfunction, which led to a reduction in mitochondrial total dehydrogenase activity. Mitochondria pretreated with EA exposed to arsenic at various concentrations led to a reversal of ROS production and mitochondrial damage. Our results showed that mitochondria were significantly affected when exposed to arsenic, which resulted in excessive ROS production and mitochondrial membrane disruption. Pretreatment with EA, reduced ROS amounts, mitochondrial damage, and restored total dehydrogenase activity specifically associated with mitochondrial complex II. EA protective characteristics may be accomplished particularly throughout the mitochondrial maintenance either directly by its antioxidant property or indirectly through its maintaining of complex II. These findings also suggest a potential role for EA in treating or preventing mitochondria associated disorders.

Oral simvastatin administration delays castration-resistant progression and reduces intratumoral steroidogenesis of LNCaP prostate cancer xenografts.

BACKGROUND: Growing evidence supports the idea that de novo steroidogenesis has an important role in prostate cancer's progression to the castration-resistant state following androgen deprivation therapy. Therefore, reducing the availability of cholesterol for use as a precursor in androgen synthesis may reduce proliferation and disease progression. METHODS: LNCaP xenograft-bearing mice were castrated and administered simvastatin via diet, and tumor volume and PSA concentration were monitored for 8 weeks post castration. Levels of serum and intratumoral androgens along with serum simvastatin and common toxicity markers were measured at end point. RESULTS: Reduced post-castration tumor growth rate in simvastatin-treated mice correlated with delayed time to castration-resistant progression, determined by two serum PSA doublings from post-castration nadir, when compared with xenografts in mice on control diet. At 8 weeks post castration, serum simvastatin levels were comparable to clinically relevant human doses with no evidence of overt muscle or liver toxicity. This suppressed post-castration tumor growth in the simvastatin diet group was correlated with reduced intratumoral testosterone and dihydrotestosterone levels. CONCLUSIONS: Reduced tumor growth and intratumoral androgen levels observed in simvastatin-treated, castrated mice harboring LNCaP xenograft suggests that suppressing de novo steroidogenesis can delay castration-resistant progression of this tumor model.

Displacement forces in iliac landing zones and stent graft interconnections in endovascular aortic repair: an experimental study.

OBJECTIVES: Stent graft migration influences the long-term durability of endovascular aortic repair. Flow-induced displacement forces acting on the attachment zones may contribute to migration. Proximal fixation of aortic stent grafts has been improved by using hooks, while distal fixation and stent graft interconnections depend on self-expansion forces only. We hypothesized that flow-induced displacement forces would be significant at the distal end, and would correlate with graft movements. METHODS: As part of an experimental study, an iliac limb stent graft was inserted in a pulsatile flow model similar to aortic in vivo conditions, and fixed-mounted at its proximal and distal ends to strain gauge load cells. Peak displacement forces at both ends and pulsatile graft movement were recorded at different graft angulations (0-90°), perfusion pressures (145/80, 170/90, or 195/100 mmHg), and stroke frequencies (60-100 b.p.m.). RESULTS: Flow-induced forces were of the same magnitude at the proximal and distal end of the stent graft (peak 1.8 N). Both the forces and graft movement increased with angulation and perfusion pressure, but not with stroke rate. Graft movement reached a maximum of 0.29 ± 0.01 mm per stroke despite fixed ends. There were strong correlations between proximal and distal displacement forces (r = 0.97, p < .001), and between displacement forces and graft movement (r = 0.98, p < .001). CONCLUSIONS: Pulsatile flow through a tubular untapered stent graft causes forces of similar magnitude at both ends and induces pulsatile graft movements in its unsupported mid-section. Peak forces are close to those previously reported to be required to extract a stent graft. The forces and movements increase with increasing graft angulation and perfusion pressure. Improved anchoring of the distal end of stent grafts may be considered.

The influence of growth hormone/insulin-like growth factor deficiency on prostatic dysplasia in pbARR2-Cre, PTEN knockout mice.

BACKGROUND: Elevated insulin-like growth factor-I (IGF-I) serum levels and phosphatase and tensin homolog (PTEN) loss are prostate cancer (PCa) risk factors that enhance androgen-responsive and castration-resistant PCa xenografts growth. METHODS: The impact of suppressed growth hormone (GH)/IGF-I levels on neoplastic initiation of PTEN-deficient prostate epithelia was assessed histologically and by epithelial-to-mesenchymal marker expression in Ghrhr D60G homozygous (lit/lit) and heterozygous (lit/+) pbARR2-Cre, PTEN(fl/fl) (PTEN-/-) mice. How suppressed GH/IGF-I levels impacted growth of PTEN-/- mouse-derived prostate cells (MPPK) was examined by growth and survival signaling of cells cultured in lit/+ or lit/lit serum. RESULTS: Body weight, prostate weight and serum GH and IGF-I levels were reduced in lit/lit relative to lit/+ PTEN-/- littermates. While the anterior lobes of lit/+ PTEN-/- prostates consistently presented swollen, indicative of ductal blockage, the degree of prostatic dysplasia in 15- and 20-week-old lit/lit and lit/+ PTEN-/- mice was indistinguishable as measured by normalized prostatic weight, tissue histology, or probasin, PSP94, E-cadherin, N-cadherin and vimentin expression. However, growth and AKT activation of MPPK cells was decreased when cultured in lit/lit serum as compared with lit/+ serum and restored in lit/lit serum supplemented with IGF-I and, to a lesser extent, GH. CONCLUSIONS: These results suggest that initiation of prostate carcinogenesis by loss of PTEN is not influenced by germline variation of genes encoding signaling molecules in the GH/IGF-I axis, but suggests that these factors may affect the progression of dysplastic phenotype and supports previous studies, indicating that the GH/IGF milieu does impact the growth of PTEN-deficient dysplastic prostatic cells once transformed.

Randomized clinical trial of subcutaneous versus interfascial bupivacaine for pain control after midline laparotomy.

BACKGROUND: Although patient-controlled analgesia for pain management after abdominal surgery is common, efforts to find alternative effective methods to control postoperative pain are continuing. The aim of this study was to compare postoperative pain levels following intermittent regional administration of bupivacaine via a catheter placed in the rectus sheath or subcutaneously at abdominal surgery through midline incisions. METHODS: Consecutive patients undergoing elective midline laparotomy were assigned randomly to a group with two catheters placed over the fascia (suprafascial group) before surgical wound closure or to a group with catheters placed between the two sheaths of each rectus muscle (interfascial group). Pain levels were determined every 12 h, both at rest and with movement, by means of a standard visual analogue scale (VAS) for 72 h after surgery. The amounts of administered opioid were recorded. RESULTS: Sixty patients were enrolled in the study (30 patients in each group).The median VAS score 36 h after surgery, both at rest and with movement, was significantly lower in the interfascial group than in the suprafascial group (P<0·050). Repeated-measures ANOVA also showed a significant difference in the postoperative VAS scores (P<0·007). The amount of self-administered morphine was significantly lower in the interfascial group, overall (P = 0·001) as well as on postoperative day 1 (P = 0·001) and day 2 (P = 0·016). Bowel sounds returned more quickly in the interfascial group (P = 0·040). CONCLUSION: Locoregional catheter administration of bupivacaine following midline laparotomy is more effective when the catheter is placed in the rectus sheath compared with suprafascial delivery. REGISTRATION NUMBER: IRCT138810142982N1 (http://www.irct.ir).

Sox4-mediated Dicer expression is critical for suppression of melanoma cell invasion.

We previously reported reduced expression of Sox4 in metastatic melanoma and its role in suppression of cell migration and invasion through inhibition of nuclear factor (NF)-κB p50. Sox4 can also bind to the promoter sequence of Dicer, a microRNA (miRNA) biogenesis factor. Interestingly, altered expression of Dicer was also observed in cancers. However, the potential mechanisms that regulate Dicer expression and its potential significance in melanoma progression are unknown. Here, we studied the regulation of Dicer expression by Sox4 and its role in suppression of melanoma invasion. Our data showed that Sox4 positively regulates Dicer expression by binding to its promoter sequences and enhancing its activity. We found that knockdown of Dicer enhances the matrigel invasion of melanoma cells by at least twofold. In addition, we revealed that overexpression of exogenous Dicer reverts the enhanced melanoma cell invasion upon Sox4 knockdown. Furthermore, we examined the expression of Dicer protein in a large set of melanocytic lesions (n=514) at different stages by tissue microarray and found that Dicer expression is inversely correlated with melanoma progression (P<0.0001). Consistently, reduced Dicer expression was correlated with a poorer overall and disease-specific 5-year survival of patients (P=0.015 and 0.0029, respectively). In addition, we found a significant correlation between expression of Sox4 and Dicer proteins in melanoma biopsies (P=0.009), further indicating the regulation of Dicer expression by Sox4. Finally, we revealed that knockdown of Sox4 induces a major change in the expression pattern of miRNAs in melanoma cells, mainly due to reduced expression of Dicer. Our results pinpoint the regulation of Dicer expression by Sox4 in melanoma and the critical role of Dicer in suppression of melanoma invasion. Our findings on Sox4-regulated miRNA biogenesis pathway may aid toward the development of novel targeted therapeutic approaches for melanoma.

The impingement-dislocation risk of total hip replacement: effects of cup orientation and patient maneuvers.

Hip dislocation is one of the most frequent complications after total hip arthroplasty. Impingement and dislocation might be caused due to misalignment of the acetabular cup during surgery, or performing dislocation-prone activities afterwards. A finite element model was developed to predict the impingement and dislocation behavior of the prosthetic joint, for different combinations of cup orientation and patient maneuver. Four dislocation-prone activities of daily life and 25 cup orientations were analyzed to determine how close they are to the impingement and subsequent dislocation events. The angular margin results obtained indicated that the sit-to-stand and standing while bending at the waist are prone to dislocation, in particular when the cup anteversion angle is small.

Retinoic acid stimulation of the human surfactant protein B promoter is thyroid transcription factor 1 site-dependent.

Surfactant B (SP-B) is a 79-amino acid peptide critical to postnatal respiratory adaptation. Expression of SP-B by respiratory epithelial cells is regulated by developmental and hormonal influences at the level of gene transcription. Previous studies supported the role of retinoic acids (RA) and their receptors (RARs) in SP-B gene transcription. In the present study, RARalpha was detected in mouse alveolar type II epithelial cells where SP-B is synthesized and processed. Deletion and site-specific mutagenesis analysis identified clustered retinoic acid-responsive element sites in the 5'-flanking enhancer region of the hSP-B gene that bound RARalpha proteins. RAR coactivators ACTR, SRC-1, and transcriptional intermediary factor 2 (TIF2) stimulated human (h) SP-B promoter activity in a dose-dependent fashion in pulmonary adenocarcinoma H441 cells. In addition, an RAR-associated protein, CREB-binding protein (CBP), potentiated the effects of RAR on hSP-B promoter activity in H441 cells. Importantly, RA stimulation of the hSP-B promoter depends on tissue-specific thyroid transcription factor (TTF-1) DNA-binding sites. TTF-1 protein synergistically stimulated the hSP-B promoter with RARalpha, CBP, and nuclear receptor coactivators in H441 cells. In addition, TTF-1 interacted directly with RARalpha and TIF2 in the mammalian two-hybrid system. These findings support a model in which RAR/retinoid X receptor, TTF-1, coactivators, and CBP form a transcription activation complex in the upstream enhancer region of the hSP-B gene.

Inhibition of hSP-B promoter in respiratory epithelial cells by a dominant negative retinoic acid receptor.

Retinoic acid (RA) receptors (RARs) belong to the nuclear hormone receptor superfamily and play important roles in lung differentiation, growth, and gene regulation. Surfactant protein (SP) B is a small hydrophobic protein synthesized and secreted by respiratory epithelial cells in the lung. Expression of the SP-B gene is modulated at the transcriptional and posttranscriptional levels. In the present work, immunohistochemical staining revealed that RAR-alpha is present on day 14.5 of gestation in the fetal mouse lung. To assess whether RAR is required for SP-B gene transcription, a dominant negative mutant human (h) RAR-alpha403 was generated. The hRAR-alpha403 mutant was transcribed and translated into the truncated protein product by reticulocyte lysate in vitro. The mutant retained DNA binding activity in the presence of retinoid X receptor-gamma to an RA response element in the hSP-B promoter. When transiently transfected into pulmonary adenocarcinoma epithelial cells (H441 cells), the mutant hRAR-alpha403 was readily detected in the cell nucleus. Cotransfection of the mutant hRAR-alpha403 repressed activity of the hSP-B promoter and inhibited RA-induced surfactant proprotein B production in H441 cells, supporting the concept that RAR is required for hSP-B gene transcription in vitro.