ABSTRACT
INTRODUCTION: Recurrence after surgery for pilonidal sinus disease is a recognised problem and patients often re-present months after discharge. We routinely treat primary and recurrent pilonidal sinus disease with Pilonidal sinus Laser-Assisted Closure (PiLAC). Long-term outcomes following PiLAC surgery was examined following clinical and telephone review. METHODS: All patients undergoing PiLAC as a day-case between April 2016 and July 2019 were included. Patients were followed up in a nurse-led clinic until complete healing or recurrence. A prospective database and retrospective audit of notes combined with longer-term follow-up by telephone were used. RESULTS: A total of 35 patients underwent PiLAC, median age 28 (18-53 years), 28 males:7 females. A total of 28 patients had long-term (>60 days) follow-up, mean 407 days (range 67-887 days); 25/28 patients (89.3%) had healed with no recurrence on long-term follow-up. Of these 28 patients, 11 were first presentation of pilonidal disease and underwent PiLAC as their first treatment, with a 91% heal rate long term. A total of 15 patients had seton drainage prior to PiLAC, with a 93% heal rate versus no seton (83%). Fisher's exact test showed no significant difference between sex, new/recurrent pilonidal disease and seton placement (p>0.05). CONCLUSIONS: Healing after PiLAC for the treatment of primary and recurrent pilonidal sinus disease is preserved with excellent long-term outcomes. We recommend it as an alternative to surgical excision.
Subject(s)
Pilonidal Sinus , Male , Female , Humans , Adult , Treatment Outcome , Follow-Up Studies , Pilonidal Sinus/surgery , Retrospective Studies , LasersABSTRACT
The genomic landscape of head and neck squamous cell carcinoma (HNSCC) has been recently elucidated. Key epigenetic and genetic characteristics of this cancer have been reported and substantiated in multiple data sets, including those distinctive to the growing subset of human papilloma virus (HPV)-associated tumors. This increased understanding of the molecular underpinnings of HNSCC has not resulted in new approaches to treatment. Three Food and Drug Administration-approved molecular targeting agents are currently available to treat recurrent/metastatic disease, but these have exhibited efficacy only in subsets of HNSCC patients, and thus surgery, chemotherapy, and/or radiation remain as standard approaches. The lack of predictive biomarkers to any therapy represents an obstacle to achieving the promise of precision medicine. This review aims to familiarize the reader with current insights into the HNSCC genomic landscape, discuss the currently approved and promising molecular targeting agents under exploration in laboratories and clinics, and consider precision medicine approaches to HNSCC.
Subject(s)
Carcinoma, Squamous Cell/genetics , Genomics , Head and Neck Neoplasms/genetics , Carcinoma, Squamous Cell/therapy , Epigenesis, Genetic/genetics , Genetic Predisposition to Disease/genetics , Head and Neck Neoplasms/therapy , Humans , Molecular Targeted Therapy , Papillomavirus Infections/complications , Papillomavirus Infections/genetics , Precision MedicineABSTRACT
Calcium/calmodulin-dependent protein kinase II (CaMKII) is highly concentrated in the brain where its activation by the Ca2+ sensor CaM, multivalent structure, and complex autoregulatory features make it an ideal translator of Ca2+ signals created by different patterns of neuronal activity. We provide direct evidence that graded levels of kinase activity and extent of T287 (T286α isoform) autophosphorylation drive changes in catalytic output and substrate selectivity. The catalytic domains of CaMKII phosphorylate purified PSDs much more effectively when tethered together in the holoenzyme versus individual subunits. Using multisubstrate SPOT arrays, high-affinity substrates are preferentially phosphorylated with limited subunit activity per holoenzyme, whereas multiple subunits or maximal subunit activation is required for intermediate- and low-affinity, weak substrates, respectively. Using a monomeric form of CaMKII to control T287 autophosphorylation, we demonstrate that increased Ca2+/CaM-dependent activity for all substrates tested, with the extent of weak, low-affinity substrate phosphorylation governed by the extent of T287 autophosphorylation. Our data suggest T287 autophosphorylation regulates substrate gating, an intrinsic property of the catalytic domain, which is amplified within the multivalent architecture of the CaMKII holoenzyme.
Subject(s)
Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Catalytic Domain , Humans , Isoenzymes/metabolism , Phosphorylation , Post-Synaptic Density/enzymology , Protein Domains , Protein Structure, Tertiary , Substrate SpecificityABSTRACT
Enhanced pork loin chops, beef longissimus lumborum steaks, semimembranosus steaks (superficial and deep portions), ground beef, and ground turkey were displayed under light emitting diode (LED) and fluorescent (FLS) lighting in two multi-shelf, retail display cases with identical operating parameters. Visual and instrumental color, internal product temperature, case temperature, case cycling, thiobarbituric acid reactive substances (TBARS), and Enterobacteriaceae and aerobic plate counts were evaluated. Under LED, beef products (except the deep portion of beef semimembranosus steaks) showed less (P<0.05) visual discoloration. Pork loin chops had higher (P<0.05) L* values for LED lighting. Other than beef longissimus lumborum steaks, products displayed under LED lights had colder internal temperatures than products under FLS lights (P<0.05). Under LED, pork loin chops, ground turkey, and beef semimembranosus steaks had higher (P<0.05) values for TBARS. LED provides colder case and product temperatures, more case efficiency, and extended color life by at least 0.5d for longissimus and semimembranosus steaks; however, some LED cuts showed increased lipid oxidation.
Subject(s)
Food Storage , Light , Meat Products/analysis , Animals , Cattle , Enterobacteriaceae/isolation & purification , Food Microbiology , Food Preservation , Lipid Peroxidation , Muscle, Skeletal , Odorants , Plants, Edible , Swine , Temperature , Thiobarbituric Acid Reactive Substances , Time Factors , TurkeyABSTRACT
Signal transducer and activator of transcription 3 (STAT3) overactivation is a common event in many cancers, including head and neck squamous cell carcinoma (HNSCC), where STAT3 represents a promising therapeutic target. HNSCC is not characterized by frequent kinase mutations, in contrast to some malignancies where mutational activation of kinases upstream of STAT3 is common. Instead, STAT3 may be activated by loss-of-function of negative regulators of STAT3, including by promoter hypermethylation of PTPRT. Here we first analyzed The Cancer Genome Atlas data and determined that the PTPRT promoter is frequently hypermethylated in several cancers, including HNSCC (60.1% of tumors analyzed) in association with downregulation of PTPRT mRNA expression and upregulation of pSTAT3 expression. These findings were confirmed in an independent cohort of HNSCC tumors by methylation-specific PCR and immunohistochemistry. We demonstrate that PTPRT promoter methylation and gene silencing is reversible in HNSCC cells, leading to PTPRT-specific downregulation of pSTAT3 expression. We further show that PTPRT promoter methylation is significantly associated with sensitivity to STAT3 inhibition in HNSCC cells, suggesting that PTPRT promoter methylation may serve as a predictive biomarker for responsiveness to STAT3 inhibitors in clinical development.
Subject(s)
Carcinoma, Squamous Cell/genetics , DNA Methylation/genetics , Head and Neck Neoplasms/genetics , Receptor-Like Protein Tyrosine Phosphatases, Class 2/genetics , STAT3 Transcription Factor/biosynthesis , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Head and Neck Neoplasms/pathology , Humans , Promoter Regions, Genetic , STAT3 Transcription Factor/genetics , Signal Transduction , Squamous Cell Carcinoma of Head and NeckABSTRACT
A deeper understanding of the role of autophagy, literally 'self-eating', in normal and cancer cell biology has emerged over the last few years. Autophagy serves as a vehicle for cells to respond to various stressors including genomic, hypoxic and nutrient stress, and to oppose mechanisms of 'programmed' cell death. Here, we review not only mechanisms of cell death and cell survival but also the early successes in applying autophagy inhibition strategies in solid tumors using the only currently available clinical inhibitor, oral hydroxychloroquine. In acute leukemia, currently available chemotherapy drugs promote cell death and demonstrate clinical benefit, but relapse and subsequent chemotherapy resistance is common. Increasing preclinical data suggest that autophagy is active in leukemia as a means of promoting cell survival in response to chemotherapy. We propose coupling autophagy inhibition strategies with current cytotoxic chemotherapy and discuss synergistic combinations of available anti-leukemic therapies with autophagy inhibition. Furthermore, novel autophagy inhibitors are in development and promise to provide new therapeutic opportunities for patients with leukemia.
Subject(s)
Antineoplastic Agents/therapeutic use , Autophagy/drug effects , Leukemia/drug therapy , Leukocytes/drug effects , Autophagy/genetics , Boronic Acids/therapeutic use , Bortezomib , Cell Survival/drug effects , Clinical Trials as Topic , Drug Resistance, Neoplasm/drug effects , Gene Expression , HMGB1 Protein/genetics , HMGB1 Protein/metabolism , Humans , Hydroxychloroquine/therapeutic use , Leukemia/genetics , Leukemia/metabolism , Leukemia/pathology , Leukocytes/metabolism , Leukocytes/pathology , Lysosomes/drug effects , Lysosomes/metabolism , Phagosomes/drug effects , Phagosomes/metabolism , Pyrazines/therapeutic use , Sirolimus/analogs & derivatives , Sirolimus/therapeutic useABSTRACT
The development of effective treatment strategies for most forms of acute myeloid leukemia (AML) has languished for the past several decades. There are a number of reasons for this, but key among them is the considerable heterogeneity of this disease and the paucity of molecular markers that can be used to predict clinical outcomes and responsiveness to different therapies. The recent large-scale sequencing of AML genomes is now providing opportunities for patient stratification and personalized approaches to treatment that are based on individual mutational profiles. It is particularly notable that studies by The Cancer Genome Atlas and others have determined that 44% of patients with AML exhibit mutations in genes that regulate methylation of genomic DNA. In particular, frequent mutation has been observed in the genes encoding DNA methyltransferase 3A (DNMT3A), isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2), as well as Tet oncogene family member 2. This review will summarize the incidence of these mutations, their impact on biochemical functions including epigenetic modification of genomic DNA and their potential usefulness as prognostic indicators. Importantly, the presence of DNMT3A, IDH1 or IDH2 mutations may confer sensitivity to novel therapeutic approaches, including the use of demethylating agents. Therefore, the clinical experience with decitabine and azacitidine in the treatment of patients harboring these mutations will be reviewed. Overall, we propose that understanding the role of these mutations in AML biology will lead to more rational therapeutic approaches targeting molecularly defined subtypes of the disease.
Subject(s)
DNA (Cytosine-5-)-Methyltransferases/genetics , Isocitrate Dehydrogenase/genetics , Leukemia, Myeloid, Acute/genetics , Mutation , DNA Methyltransferase 3A , Humans , Leukemia, Myeloid, Acute/drug therapy , Myelodysplastic Syndromes/genetics , Myeloproliferative Disorders/genetics , Nuclear Proteins/genetics , Nucleophosmin , Prognosis , fms-Like Tyrosine Kinase 3/geneticsABSTRACT
Signal transducer and activator of transcription (STAT) proteins comprise a family of transcription factors that are activated by cytokines, hormones and growth factors. The activation of STAT proteins plays a key role in the production of mature hematopoietic cells via effects on cellular proliferation, survival and lineage-specific differentiation. Emerging evidence also demonstrates frequent, constitutive activation of STATs in primary leukemia specimens. Moreover, roles for STATs in promoting leukemia development have been delineated in numerous preclinical studies. This review summarizes our current understanding of STAT protein involvement in normal hematopoiesis and leukemogenesis, as well as recent advances in the development and testing of novel STAT inhibitors.
Subject(s)
Cell Transformation, Neoplastic/metabolism , Hematopoiesis , Leukemia/metabolism , STAT Transcription Factors/metabolism , Alternative Splicing , Animals , Cell Transformation, Neoplastic/genetics , Hematopoiesis/genetics , Humans , Leukemia/drug therapy , Leukemia/genetics , Molecular Targeted Therapy , STAT Transcription Factors/antagonists & inhibitors , STAT Transcription Factors/genetics , Signal Transduction/drug effectsABSTRACT
INTRODUCTION: The optimisation of convection-enhanced drug delivery (CED) to the brain is fundamentally reliant on minimising drug reflux. The aim of this study was to evaluate the performance of a novel reflux-resistant CED catheter incorporating a recessed-step and to compare its performance to previously described stepped catheters. METHODS: The in vitro performance of the recessed-step catheter was compared to a conventional "one-step" catheter with a single transition in outer diameter (OD) at the catheter tip, and a "two-step" design comprising two distal transitions in OD. The volumes of distribution and reflux were compared by performing infusions of Trypan blue into agarose gels. The in vivo performance of the recessed-step catheter was then analysed in a large animal model by performing infusions of 0.2% Gadolinium-DTPA in Large White/Landrace pigs. RESULTS: The recessed-step catheter demonstrated significantly higher volumes of distribution than the one-step and two-step catheters (p=0.0001, one-way ANOVA). No reflux was detected until more than 100 ul had been delivered via the recessed-step catheter, whilst reflux was detected after infusion of only 25 ul via the 2 non-recessed catheters. The recessed-step design also showed superior reflux resistance to a conventational one-step catheter in vivo. Reflux-free infusions were achieved in the thalamus, putamen and white matter at a maximum infusion rate of 5 ul/min using the recessed-step design. CONCLUSION: The novel recessed-step catheter described in this study shows significant potential for the achievement of predictable high volume, high flow rate infusions whilst minimising the risk of reflux.
Subject(s)
Brain/physiology , Catheters , Drug Delivery Systems , Algorithms , Animals , Brain/anatomy & histology , Catheterization/methods , Coloring Agents , Contrast Media , Convection , Gadolinium DTPA , Image Processing, Computer-Assisted , Putamen , Sepharose , Swine , Thalamus , Trypan BlueABSTRACT
Convection-enhanced delivery (CED) describes a novel method of drug delivery to the brain through intraparenchymal microcatheters. One of the barriers to effective translation of CED to clinical trials is the requirement for intermittent delivery over prolonged periods. This is particularly relevant for delivery of neurotrophins for the treatment of Parkinson's disease where chronic infusion of glial cell-line derived neurotrophic factor (GDNF) with subcutaneously implanted pumps has been associated with poor distribution and local toxicity due to point source accumulation. We have previously described the development of an implantable catheter for CED which facilitates repeated drug administrations at intervals of up to one month. The aim of this study was to determine the feasibility of implanting a transcutaneous bone-anchored port (TBAP) which facilitates chronic intermittent drug delivery to the brain. We describe the design and development of a titanium port which was implanted in Large White and NIH miniature pigs for periods of up to three months. By intermittently accessing the port with a needle administration set it was possible to repeatedly perform CED infusions at one month intervals. This study confirms the safety and feasibility of performing intermittent CED through a transcutaneous bone-anchored port. The use of a transcutaneous port has the potential to facilitate clinical translation of CED of therapeutics requiring intermittent delivery to achieve optimum efficacy whilst negating the need for subcutaneously implanted pumps.
Subject(s)
Brain/drug effects , Drug Delivery Systems/methods , Glial Cell Line-Derived Neurotrophic Factor/administration & dosage , Suture Anchors , Animals , Convection , Infusion Pumps, Implantable , SwineABSTRACT
The effect of contact location information on virtual edge perception was investigated in two experiments. In Experiment 1, participants discriminated edge sharpness under force-alone and force-plus-contact-location conditions using a 4.8 mm radius contact roller. Virtual objects were 2D profiles of edges with two adjoining surfaces. For both conditions, the Just Noticeable Difference (JND) in change of edge radius increased from 2.3 to 7.4 mm as edge radii increased from 2.5 to 20.0 mm; there was no significant difference between the two conditions. A follow-up experiment with contact location alone resulted in higher edge sharpness JNDs. In Experiment 2, the same edge sharpness discrimination task was performed using a smaller contact roller (R = 1.5 mm) to investigate the effect of roller size. The JNDs for the smaller roller were not statistically significant from those of the larger roller. Our results suggest that 1) contact location cues alone are capable of conveying edge sharpness information, but that force cues are dominant when both types of cues are available; and 2) the radius of the contact roller does not significantly affect the user's ability to discriminate edge sharpness, indicating that the participants could use the changes in contact location to judge curvature.
ABSTRACT
Convection-enhanced delivery (CED) is a promising technique for the administration of therapeutic agents such as cytotoxics, neurotrophins and enzymes to the brain. In this study we describe the development of an implantable catheter system that is compatible with long-term intermittent CED. Catheters made from fused silica, PEEK or carbothane, and of various internal and external diameters were implanted in the striatum of rats and assessed for patency at 21 or 28 days. A high-rate of catheter blockage was observed with all fused silica and PEEK catheters. Carbothane catheters with an outer diameter of 0.6mm and an inner diameter of 0.35 mm had significantly lower rates of blockage (P≤0.01). Carbothane catheters were then implanted into 4 Large White/Landrace pigs and 4 NIH miniature pigs and infusions undertaken at monthly intervals to evaluate catheter patency and infusate distribution. Catheter patency was demonstrated for a maximum period of 163 days in one animal. Widespread and reproducible intraputamenal CED could be achieved with intermittent drug delivery at flow-rates as high as 5 µl/min. Problems were encountered using the pig model due to catheter distortion from rapid animal growth. In conclusion, it is possible to achieve intermittent high-flow CED with a chronic implanted carbothane catheter with a low rate of catheter blockage.
Subject(s)
Catheters, Indwelling/standards , Infusion Pumps, Implantable/standards , Neuropharmacology/instrumentation , Neurosurgical Procedures/instrumentation , Prosthesis Implantation/methods , Animals , Catheters, Indwelling/adverse effects , Infusion Pumps, Implantable/adverse effects , Male , Models, Animal , Neuropharmacology/methods , Neurosurgical Procedures/adverse effects , Neurosurgical Procedures/methods , Rats , Rats, Wistar , Sus scrofaABSTRACT
Achieving accurate intracranial electrode or catheter placement is critical in clinical practice in order to maximise the efficacy of deep brain stimulation and drug delivery respectively as well as to minimise side-effects. We have developed a highly accurate and robust method for MRI-guided, stereotactic delivery of catheters and electrodes to deep target structures in the brain of pigs. This study outlines the development of this equipment and animal model. Specifically this system enables reliable head immobilisation, acquisition of high-resolution MR images, precise co-registration of MRI and stereotactic spaces and overall rigidity to facilitate accurate burr hole-generation and catheter implantation. To demonstrate the utility of this system, in this study a total of twelve catheters were implanted into the putamen of six Large White Landrace pigs. All implants were accurately placed into the putamen. Target accuracy had a mean Euclidean distance of 0.623 mm (standard deviation of 0.33 mm). This method has allowed us to accurately insert fine cannulae, suitable for the administration of therapeutic agents by convection-enhanced delivery (CED), into the brain of pigs. This study provides summary evidence of a robust system for catheter implantation into the brain of a large animal model. We are currently using this stereotactic system, implantation procedure and animal model to develop catheter-based drug delivery systems that will be translated into human clinical trials, as well as to model the distribution of therapeutic agents administered by CED over large volumes of brain.
Subject(s)
Magnetic Resonance Imaging , Neuronavigation/instrumentation , Neuronavigation/methods , Animals , Catheters, Indwelling , Immobilization/instrumentation , Immobilization/methods , Restraint, Physical/instrumentation , Restraint, Physical/methods , Surgery, Computer-Assisted , SwineABSTRACT
We used four pregnant Holstein cows to delineate ruminal adaptations as cows transitioned from one lactation to the next. Cows were fed typical diets through far-off and close-up dry periods and lactation. We measured ruminal characteristics on day 72 (late lactation), 51 (far-off dry), 23 and 9 (close-up dry) prepartum and on days 6, 20, 34, 48, 62, 76 and 90 postpartum (early lactation). Measurements included: ruminal fill (weight of actual contents), ruminal capacity (volume of rumen when fully filled), digestibilities and ruminal passage rates. Ruminal capacity tended to increase linearly during early lactation but was stable during dry and transition periods. Both total and liquid fill decreased linearly during the dry period, increased across parturition, and increased linearly through early lactation. Dry matter fill decreased as cows were fed the close-up diet at day 23 prepartum then increased near parturition and continued to increase across early lactation. Solid passage rate was greatest when cows were fed the close-up diet, and decreased throughout the transition period. In lactation, solid passage rate responded quadratically with peak at day 48 followed by decreases through day 90 postpartum. Liquid passage increased linearly across the transition period. Total tract organic matter digestibilities increased linearly over the dry period with significant increases prior to or immediately after parturition, then they remained relatively stable over early lactation until they increased at day 90. Fibre digestibilities demonstrated quadratic responses over early lactation, being higher on day 6 and day 90 than at other times. Starch digestibilities decreased linearly across both the dry and transition periods with decreases in lactation until day 62 followed by increases until day 90. High producing lactating dairy cows go through a multitude of ruminal adaptations, in terms of digestion, passage, capacity and fill, as they transition from one lactation to the next.
Subject(s)
Cattle/physiology , Dairying , Peripartum Period/physiology , Rumen/physiology , Animal Feed , Animals , Diet/veterinary , Digestion/physiology , Female , Gastrointestinal Contents/chemistry , Gastrointestinal Motility/physiology , Lactation/physiology , PregnancyABSTRACT
We evaluated growth-related responses to ractopamine in steers and heifers. Sixteen Angus steers (512 kg) and 16 Angus heifers (473 kg) housed in individual pens were used in a complete block design. At 90 to 97 d before the experiment, steers were implanted with 120 mg of trenbolone acetate and 24 mg of estradiol-17beta (Component TE-S) and heifers were implanted with 140 mg of trenbolone acetate and 14 mg of estradiol-17beta (Component TE-H). Treatments were arranged as a 2 x 2 factorial and included sex (steer vs. heifer) and ractopamine-HCl (0 or 200 mg/d). Cattle were fed a diet based on steam-flaked corn once daily. Blood and LM and biceps femoris (BF) biopsy samples were collected on d 0 (before ractopamine feeding) and after 14 and 28 d of ractopamine feeding. Serum insulin concentrations were not affected by ractopamine or sex. Serum IGF-I concentrations were greater in steers than heifers (P < 0.001), and steers demonstrated greater IGF-I mRNA expression in BF than heifers (P = 0.05). Ractopamine decreased serum IGF-I concentrations in heifers on d 14, but increased serum IGF-I concentrations in steers on d 28 (sex x ractopamine x day interaction; P = 0.03). Ractopamine did not affect (P >or= 0.19) mRNA expression of IGF-I, IGFBP-3, or calpastatin in BF or LM. However, ractopamine led to increases in LM expression of IGFBP-5 in heifers, but to decreases in expression in steers (ractopamine x sex interaction; P = 0.04). Ractopamine decreased myosin heavy chain IIA mRNA expression in BF (P = 0.04) but not in LM (P = 0.99). Ractopamine decreased beta(2)-receptor mRNA expression in LM of steers on d 14, but not on d 28; in contrast, expression of beta(2)-receptor mRNA in LM of heifers was not affected by ractopamine (sex x ractopamine x day interaction; P = 0.03). Although there were a few criteria for which ractopamine led to differences in response between steers and heifers, there were no striking disparities to suggest that the effectiveness of ractopamine would markedly differ between sexes.
Subject(s)
Cattle/growth & development , Growth Substances/pharmacology , Muscle, Skeletal/drug effects , Phenethylamines/pharmacology , Animals , Calcium-Binding Proteins/blood , Cattle/blood , Female , Gene Expression/drug effects , Insulin/blood , Insulin-Like Growth Factor Binding Protein 3/blood , Insulin-Like Growth Factor I/analysis , Male , Muscle, Skeletal/growth & development , Muscle, Skeletal/metabolism , Polymerase Chain Reaction , Sex FactorsABSTRACT
To determine the effects of feeding zilpaterol hydrochloride (ZH) for 0, 20, 30, or 40 d (ZH0, ZH20, ZH30, ZH40) on semimembranosus (SM) steak color and color stability in 3 packaging systems, SM subprimals were removed from 60 calf-fed Holstein steers 24 h postmortem. A 7.62-cm-thick portion was removed from each subprimal and stored (2 degrees C) for 21 d; then two 2.54-cm-thick steaks were cut, overwrapped with polyvinyl chloride (PVC) film, and assigned to 0 or 3 d of display. Remaining portions of the subprimals were vacuum packaged for 10 d and then enhanced (10% with a solution containing 0.3% sodium chloride, 0.35% phosphate, and 0.05% rosemary extract), cut into steaks, packaged in high-oxygen (HO-MAP) or carbon monoxide (CO-MAP) modified atmosphere packaging (MAP), and assigned to 0, 3, or 5 d (HO-MAP) or 0 or 9 d (CO-MAP) of display. Panelists evaluated the deep and superficial portions of SM steaks for initial color, display color, discoloration, pH, L*, a*, b*, hue angle, and saturation indices. Feeding duration did not affect (P > 0.05) initial color scores of steaks in PVC. Steaks displayed in PVC from ZH20 or ZH30 diets were slightly brighter and less discolored than the ZH40 treatment. For enhanced steaks in HO-MAP, ZH20 steaks were darker on d 5 (P < 0.05) and more discolored (P < 0.05) on d 3 through 5 than all other diet treatments. For enhanced steaks from steers fed ZH40 and in CO-MAP, the deep and superficial SM tended (P > 0.05) to have improved display color compared with other dietary regimens; however, steaks in CO-MAP from all feeding durations had less than 20% metmyoglobin through d 9 of display. Overall, feeding ZH20 might result in steaks with slightly less color stability when packaged in HO-MAP; however, feeding ZH20 or ZH30 to calf-fed Holstein steers will yield steaks that have equal to or more desirable color traits when packaged in PVC or CO-MAP. Regardless of ZH feeding regimen, HO-MAP and CO-MAP extended the color life of the SM. The CO-MAP system minimized color differences between the superficial and deep portions of the SM muscle and extended total case life compared with traditional and HO-MAP packaging.
Subject(s)
Cattle/physiology , Food Additives/pharmacology , Meat/standards , Trimethylsilyl Compounds/pharmacology , Animal Feed , Animals , Color , Food Additives/administration & dosage , Food Packaging , Male , Time Factors , Trimethylsilyl Compounds/administration & dosageSubject(s)
Cell Differentiation , Early Growth Response Protein 1/genetics , Leukemia, Promyelocytic, Acute/genetics , Leukemia, Promyelocytic, Acute/pathology , src-Family Kinases/genetics , Antineoplastic Agents/pharmacology , Gene Expression Profiling , Humans , Oligonucleotide Array Sequence Analysis , Pyrimidines/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tretinoin/pharmacology , Tumor Cells, Cultured , src-Family Kinases/antagonists & inhibitorsABSTRACT
The objective of this research was to determine the effects of feeding zilpaterol hydrochloride (ZH) for 0, 20, 30, or 40 d before slaughter (ZH0, ZH20, ZH30, or ZH40, respectively) on semimembranosus (SM) color development and stability. A 7.62-cm-thick portion was removed from 60 beef steer SM subprimals and stored (2 degrees C) for 21 d; then two 2.54-cm-thick steaks were cut, overwrapped with polyvinyl chloride (PVC) film, and assigned to 0 or 3 d of display. Remaining portions of the subprimals were stored in a vacuum for 10 d and then enhanced 10% to a meat concentration of 0.3% sodium chloride, 0.35% phosphate, and 0.05% rosemary extract. Steaks were packaged in a high-oxygen (HO-MAP) or carbon monoxide (CO-MAP) modified atmosphere and assigned to 0, 3, or 5 d (HO-MAP) or 0 or 9 d (CO-MAP) of display. The deep (DSM) and superficial (SSM) portions of steaks were evaluated for initial color, display color, discoloration, pH, L*, a*, b*, hue angle, and saturation indices. For steaks in PVC, no differences (P > 0.05) occurred in initial or discoloration color scores because of ZH feeding duration. The enhanced SSM steaks from ZH20 in PVC were brighter red (P < 0.05) than SSM steaks from ZH40 in PVC. The DSM in PVC had less (P < 0.05) pH and paler (P < 0.05) color than the SSM. Display color scores for the DSM of PVC steaks were brighter red (P < 0.05) than the SSM initially (d 0 and 1), but the DSM discolored faster (P < 0.05) than the SSM on d 1 to 3. The SM steaks from steers fed ZH20 or ZH30 were slightly brighter and less discolored during display in PVC than the ZH40 diet. For enhanced steaks in HO-MAP, the DSM of ZH20 and ZH30 diets displayed 4 d and the DSM of ZH20 displayed 5 d was a brighter (P < 0.05) red than the DSM from ZH40. At display d 1 and 5, the SSM of ZH20 steaks in HO-MAP was a brighter (P < 0.05) red than SSM steaks from ZH40. The SSM of ZH40 HO-MAP steaks was darker (P < 0.05) red on d 3 than the SSM from other diets. For enhanced steaks in CO-MAP, ZH30 steaks were brighter (P < 0.05) red than ZH0 or ZH40 steaks on d 0 and 9 of display. Steaks in CO-MAP from all feeding durations were less than 20% discolored through d 9. The DSM was lighter (P < 0.05) than the SSM on d 0 for steaks packaged in HO-MAP and CO-MAP. Feeding cattle ZH for 20 or 30 d will yield steaks with color characteristics equal to or better than steaks from control cattle, whereas feeding ZH for 40 d will likely produce less desirable meat color traits.
Subject(s)
Cattle , Food Additives/pharmacology , Food Packaging/methods , Meat/standards , Trimethylsilyl Compounds/pharmacology , Aerobiosis , Animal Feed , Animals , Cattle/physiology , Color , Food Additives/administration & dosage , Male , Meat-Packing Industry , Time Factors , Trimethylsilyl Compounds/administration & dosageABSTRACT
This experiment investigated the combined effects of two dry-aging methods (unpackaged and in a bag), two loin-cut styles (bone-in shell loins and boneless strip loins), and two aging times (21 and 28days) on the physical, chemical, sensory, and microbial properties of dry-aged beef. Sections from shell and strip loin were assigned randomly to be aged unpackaged or aged packaged in a bag with high moisture permeability. Weight losses increased with aging time. Shell loins lost more (P<0.05) weight during aging compared with strip loins; dry aging in a bag had less (P<0.05) weight loss than unpackaged aging. There were no differences (P>0.05) in any of the sensory traits between shell and strip loins or dry aging using a traditional method or in a bag. Dry aging in a bag creates positive effects on yields, no negative effects on product quality, and adds flexibility and control of the aging environment.