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Future Directions and Resource Needs for National Heart, Lung, and Blood Institute (NHLBI) Gene Therapy Research: A Report of an NHLBI Workshop. Hum Gene Ther 2023; 34:83-89. [PMID: 36794978 PMCID: PMC10081695 DOI: 10.1089/hum.2022.29233.tga] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
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Abstract
Thyroid hormones have long been known to have a range of effects on the cardiovascular system. However, significant knowledge gaps exist concerning the precise molecular and biochemical mechanisms governing these effects and the optimal strategies for management of abnormalities in thyroid function in patients with and without preexisting cardiovascular disease. In September 2017, the National Heart, Lung, and Blood Institute convened a Working Group with the goal of developing priorities for future scientific research relating thyroid dysfunction to the progression of cardiovascular disease. The Working Group reviewed and discussed the roles of normal thyroid physiology, the consequences of thyroid dysfunction, and the effects of therapy in 3 cardiovascular areas: cardiac electrophysiology and arrhythmias, the vasculature and atherosclerosis, and the myocardium and heart failure. This report describes the current state of the field, outlines barriers and challenges to progress, and proposes research opportunities to advance the field, including strategies for leveraging novel approaches using omics and big data. The Working Group recommended research in 3 broad areas: (1) investigation into the fundamental biology relating thyroid dysfunction to the development of cardiovascular disease and into the identification of novel biomarkers of thyroid hormone action in cardiovascular tissues; (2) studies that define subgroups of patients with thyroid dysfunction amenable to specific preventive strategies and interventional therapies related to cardiovascular disease; and (3) clinical trials focused on improvement in cardiovascular performance and cardiovascular outcomes through treatment with thyroid hormone or thyromimetic drugs.
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Abstract
Thyroid hormones have long been known to have a range of effects on the cardiovascular system. However, significant knowledge gaps exist concerning the precise molecular and biochemical mechanisms governing these effects and the optimal strategies for management of abnormalities in thyroid function in patients with and without preexisting cardiovascular disease. In September 2017, The National Heart, Lung, and Blood Institute convened a Working Group with the goal of developing priorities for future scientific research relating thyroid dysfunction to the progression of cardiovascular disease. The Working Group reviewed and discussed the roles of normal thyroid physiology, the consequences of thyroid dysfunction, and the effects of therapy in three cardiovascular areas: cardiac electrophysiology and arrhythmias, the vasculature and atherosclerosis, and the myocardium and heart failure. This report describes the current state of the field, outlines barriers and challenges to progress, and proposes research opportunities to advance the field, including strategies for leveraging novel approaches using omics and big data. The Working Group recommended research in three broad areas: 1) investigation into the fundamental biology relating thyroid dysfunction to the development of cardiovascular disease and into the identification of novel biomarkers of thyroid hormone action in cardiovascular tissues; 2) studies that define subgroups of patients with thyroid dysfunction amenable to specific preventive strategies and interventional therapies related to cardiovascular disease; and 3) clinical trials focused on improvement in cardiovascular performance and cardiovascular outcomes through treatment with thyroid hormone or thyromimetic drugs.
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Cost-Effectiveness of Mitral Valve Repair Versus Replacement for Severe Ischemic Mitral Regurgitation. Circ Cardiovasc Qual Outcomes 2018. [DOI: 10.1161/circoutcomes.117.004466] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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The Gene Therapy Resource Program: A Decade of Dedication to Translational Research by the National Heart, Lung, and Blood Institute. HUM GENE THER CL DEV 2017; 28:178-186. [PMID: 29130351 DOI: 10.1089/humc.2017.170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Over a 10-year period, the Gene Therapy Resource Program (GTRP) of the National Heart Lung and Blood Institute has provided a set of core services to investigators to facilitate the clinical translation of gene therapy. These services have included a preclinical (research-grade) vector production core; current Good Manufacturing Practice clinical-grade vector cores for recombinant adeno-associated virus and lentivirus vectors; a pharmacology and toxicology core; and a coordinating center to manage program logistics and to provide regulatory and financial support to early-phase clinical trials. In addition, the GTRP has utilized a Steering Committee and a Scientific Review Board to guide overall progress and effectiveness and to evaluate individual proposals. These resources have been deployed to assist 82 investigators with 172 approved service proposals. These efforts have assisted in clinical trial implementation across a wide range of genetic, cardiac, pulmonary, and blood diseases. Program outcomes and potential future directions of the program are discussed.
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Abstract
With recent successes in gene therapy trials for hemophilia and retinal diseases, the promise and prospects for gene therapy are once again garnering significant attention. To build on this momentum, the National Institute of Neurological Disorders and Stroke and the Muscular Dystrophy Association jointly hosted a workshop in April 2014 on "Best Practices for Gene Therapy Programs," with a focus on neuromuscular disorders. Workshop participants included researchers from academia and industry as well as representatives from the regulatory, legal, and patient advocacy sectors to cover the gamut from preclinical optimization to intellectual property concerns and regulatory approval. The workshop focused on three key issues in the field: (1) establishing adequate scientific premise for clinical trials in gene therapy, (2) addressing regulatory process issues, and (3) intellectual property and commercialization issues as they relate to gene therapy. The outcomes from the discussions at this workshop are intended to provide guidance for researchers and funders in the gene therapy field.
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Gene therapy: charting a future course--summary of a National Institutes of Health Workshop, April 12, 2013. Hum Gene Ther 2015; 25:488-97. [PMID: 24773122 DOI: 10.1089/hum.2014.045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Recently, the gene therapy field has begun to experience clinical successes in a number of different diseases using various approaches and vectors. The workshop Gene Therapy: Charting a Future Course, sponsored by the National Institutes of Health (NIH) Office of Biotechnology Activities, brought together early and mid-career researchers to discuss the key scientific challenges and opportunities, ethical and communication issues, and NIH and foundation resources available to facilitate further clinical advances.
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Dr. Sonia Skarlatos and the National Heart, Lung, and Blood institute translational research and resource programs. Hum Gene Ther 2013; 24:899-905. [PMID: 24164237 PMCID: PMC3815047 DOI: 10.1089/hum.2013.2511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sonia I. Skarlatos, PhD (September 28, 1953-August 6, 2013), was the deputy director of the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute (NHLBI). This article reviews her work in establishing, leading, or facilitating extramural translational research programs supported by the NHLBI, specifically focusing on her work as a consistent advocate for the advancement of gene and cell therapies.
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Advancing translational research through the NHLBI Gene Therapy Resource Program (GTRP). HUM GENE THER CL DEV 2013; 24:5-10. [PMID: 23692378 PMCID: PMC4003470 DOI: 10.1089/humc.2013.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 02/19/2013] [Indexed: 11/13/2022] Open
Abstract
Abstract Translational research is a lengthy, complex, and necessary endeavor in order to bring basic science discoveries to clinical fruition. The NIH offers several programs to support translational research including an important resource established specifically for gene therapy researchers-the National Heart, Lung, and Blood Institute (NHLBI) Gene Therapy Resource Program (GTRP). This paper reviews the core components of the GTRP and describes how the GTRP provides researchers with resources that are critical to advancing investigational gene therapy products into clinical testing.
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Targeting the Nogo receptor complex in diseases of the central nervous system. Curr Med Chem 2011; 18:234-44. [PMID: 21110803 DOI: 10.2174/092986711794088326] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 11/21/2010] [Indexed: 11/22/2022]
Abstract
After injury to the central nervous system intrinsic factors such as myelin associated inhibitory factors inhibit cellular and axonal regeneration resulting in permanent disability. Three of these factors (Nogo-A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein) bind to a common receptor: the Nogo-66 receptor (NgR1). NgR1 is expressed mainly on neurons and is usually associated in a trimolecular complex. The second member of the complex, LINGO-1, is often connected to NgR1 function and is further found to function independently as a negative regulator of oligodendrocyte proliferation and differentiation. The third member of the NgR complex is either the p75 neurotrophin receptor, TROY, or an as yet unidentified co-receptor. Targeting of factors contained in this complex has been described to lead to the promotion of neurite outgrowth, oligodendrocyte proliferation and differentiation and inhibition of cell death. In the current review, we aim to describe the mechanisms of action of the chemical and biological compounds used in targeting NgR1 and LINGO-1. This will be achieved using three examples: blocking of ligand binding to NgR1 in treatment of spinal cord injury, antibody-mediated inhibition of LINGO-1 to promote oligodendrocyte differentiation in multiple sclerosis, and the use of soluble NgR1 to sequester Abeta peptide in the periphery in Alzheimer's disease.
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Identifying patients at high risk of a cardiovascular event in the near future: current status and future directions: report of a national heart, lung, and blood institute working group. Circulation 2010; 121:1447-54. [PMID: 20351302 DOI: 10.1161/circulationaha.109.904029] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Cardiovascular disease in adult and pediatric HIV/AIDS. J Am Coll Cardiol 2009; 54:1185-8. [PMID: 19761941 DOI: 10.1016/j.jacc.2009.05.055] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Accepted: 05/06/2009] [Indexed: 11/26/2022]
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Abstract
Acoustical measurements, electron spin resonance, and Raman spectroscopy have been employed to probe sulfur over the temperature range 80-180 degrees C, which includes the polymerization transition and the supercooled liquid state. Acoustical properties (sound velocity, absorption, and impedance) have been studied with both longitudinal and transverse waves at frequencies between 500 kHz and 22 MHz. The results confirm that polymeric sulfur is a solution of long chain molecules in monomeric solvent, and that the polymerization transition is not a second-order phase transition, as was proposed theoretically. Sulfur is a viscous liquid, but not viscoelastic, both below and above the polymerization transition temperature. It is shown that the classical Navier-Stokes theory is not applicable to the sound absorption in liquid sulfur in the highly viscous state.
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Phage display epitope mapping of human neutrophil flavocytochrome b558. Identification of two juxtaposed extracellular domains. J Biol Chem 2001; 276:2053-61. [PMID: 11027685 DOI: 10.1074/jbc.m006236200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Despite extensive experimental and clinical evidence demonstrating the critical role of flavocytochrome b558 (Cyt b) in the NADPH-dependent oxidase, there is a paucity of direct structural data defining its topology in the phagocyte membrane. Unlike other Cyt b-specific monoclonal antibodies, 7D5 binds exclusively to an extracellular domain, and identification of its epitope should provide novel insight into the membrane topology of Cyt b. To that end, we examined biochemical features of 7D5-Cyt b binding and used the J404 phage display nonapeptide library to identify the bound epitope. 7D5 precipitated only heterodimeric gp91-p22phox and not individual or denatured Cyt b subunits from detergent extracts of human neutrophils and promyelocytic leukemia cells (gp91-PLB). Moreover, 7D5 precipitated precursor gp65-p22phox complexes from detergent extracts of the biosynthetically active gp91-PLB cells, demonstrating that complex carbohydrates were not required for epitope recognition. Epitope mimetics selected from the J404 phage display library by 7D5 demonstrated that (226)RIVRG(230) and (160)IKNP(163) regions of gp91phox were both bound by 7D5. These studies reveal specific information about Cyt b membrane topology and structure, namely that gp91phox residues (226)RIVRG(230) and (160)IKNP(163) are closely juxtaposed on extracytoplasmic domains and that predicted helices containing residues Gly(165)-Ile(190) and Ser(200)-Glu(225) are adjacent to each other in the membrane.
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STS-PCR markers appropriate for wheat-barley introgression. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1996; 93:826-832. [PMID: 24162414 DOI: 10.1007/bf00224082] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/1995] [Accepted: 04/19/1996] [Indexed: 06/02/2023]
Abstract
Introgression of chromosomal segments across large taxonomic distances has long been an objective of scientists interested in understanding the relationships between genes and their effect on phenotype. Barley and wheat represent cultivated members of the Triticeae with different zones of adaptation, different responses to pathogens, and different end-use characteristics. Introduction of small, well-characterized chromosomal segments among grass relatives presents an opportunity to both better understand how genes perform in novel genomic environments and to learn more about the evolutionary novelties which differentiate related species. Since the distribution of the wheat-barley addition lines, the potential power and value of a comprehensive series of wheat/barley translocation lines has been widely appreciated. A scarcity of easy-touse markers which unambiguously distinguish barley loci from their wheat homologues has limited the ability of scientists to identify the relatively rare inter-chromosomal recombination events which are the necessary antecedents of these lines. Since the single most critical pathogen affecting U.S. wheat producers is Karnal bunt (Tilletia indica) and since barley carries a gene conferring immunity, molecular markers may prove practically and immediately important. In this report we describe a series of 135 barley-specific markers amplified by 115 primer sets developed from sequences from previously mapped restriction fragment length polymorphism (RFLP) markers. These easily distinguish the cognate barley products from their wheat counterparts and should find ready use in the identification of lines which contain wheat/barley translocation events.
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Revised interpretation of oxacillin MICs for Staphylococcus epidermidis based on mecA detection. Antimicrob Agents Chemother 1995; 39:982-4. [PMID: 7786008 PMCID: PMC162666 DOI: 10.1128/aac.39.4.982] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In 1992 and 1993, at The Ohio State University Medical Center, a larger proportion of Staphylococcus epidermidis strains required oxacillin MICs of 1 to 2 micrograms/ml than did Staphylococcus aureus strains. mecA genotype was correlated with antimicrobial susceptibility for selected clinical S. epidermidis strains. All 14 strains that required oxacillin MICs of < or = 0.25 microgram/ml and 2 of 5 strains that required oxacillin MICs of 0.5 microgram/ml were susceptible by 1-microgram oxacillin disk test and were mecA negative. Three of 5 strains that required oxacillin MICs of 0.5 microgram/ml and all 18 strains that required oxacillin MICs of > or = 1.0 microgram/ml were resistant by oxacillin disk test and were mecA positive. Current National Committee for Clinical Laboratory Standards MIC interpretive criteria may underestimate methicillin resistance among S. epidermidis strains.
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Abstract
Auramine-stained mycobacterial smears from 136 clinical specimens were interpreted by using the UV ParaLens adapter (Beckton Dickinson), and results were compared with smear interpretations using a traditional fluorescent microscope and culture. The sensitivity and specificity of the ParaLens were 84 and 93%, respectively. Smears yielding discrepant results were overstained by the Kinyoun method. Overall, the sensitivity of auramine-stained smears interpreted with the UV ParaLens was comparable to that of Kinyoun-stained smears.
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Rapid identification of Staphylococcus aureus from blood culture bottles by a classic 2-hour tube coagulase test. J Clin Microbiol 1995; 33:50-2. [PMID: 7699065 PMCID: PMC227878 DOI: 10.1128/jcm.33.1.50-52.1995] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The rapid, reliable identification of Staphylococcus aureus from positive blood cultures provides important information. While multiple methodologies for detection of S. aureus from blood culture broths exist, none is satisfactory. Immunologic tests have shown varied sensitivities, the thermonuclease test, while sensitive, is not practical for routine use, and probe tests are expensive. Few studies have addressed using the tube coagulase test (TCT). This study compared two immunologic methods, the Staph Latex kit (Remel Laboratories) and the Staphaurex kit (Wellcome Diagnostics), with a rabbit plasma TCT (Difco Laboratories) to identify S. aureus within 2 h directly from blood culture broths and pelleted supernatants from BACTEC (Johnston Laboratories) bottles. One hundred twelve unique clinical blood culture isolates consistent with a Gram stain for staphylococci and 68 negative blood culture bottles seeded with a variety of gram-positive organisms were evaluated. Sensitivity and specificity among clinical specimens for the 2-h TCT were 79.5 and 100%, respectively. Sensitivities for the immunologic methods were 12.8 and 10.2% for the Staphaurex and Remel Staph Latex, respectively, and specificities for both were 100%. These results contradict previously reported results for both immunologic and TCT methods and dictate that a specific as well as a sensitive method be employed. The 2-h TCT was found to be a cost-effective, reliable, and rapid method for identifying S. aureus from positive blood cultures.
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Clozapine and refractory obsessive-compulsive disorder: a case report. J Clin Psychopharmacol 1994; 14:209-11. [PMID: 8027421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Pericarditis: a probable complication of endocarditis due to Haemophilus influenzae. Clin Infect Dis 1994; 18:648-9. [PMID: 8038326 DOI: 10.1093/clinids/18.4.648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Abstract
Oerskovia species, which are Nocardia-like bacteria that have rarely been found to cause human disease, are usually found in association with a foreign body with removal of the infected focus being necessary for cure. We present a case of Oerskovia xanthineolytica bacteremia in a patient with metastatic breast cancer, community-acquired pneumonia, and a tunneled subcutaneous central venous catheter. Although the actual source of the bacteremia in this case is not proven, this patient's presentation with apparent lobar pneumonia and her improvement on antibiotics without catheter removal suggest that Oerskovia may be capable of causing primary pulmonary infection in the immunocompromised host.
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Dysarthria and a numb hand in an elderly woman. HOSPITAL PRACTICE (OFFICE ED.) 1992; 27:71-4. [PMID: 1730798 DOI: 10.1080/21548331.1992.11705343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Abstract
Patellar complications following total knee arthroplasty (TKA) have begun to emerge as a major cause of failure. In an effort to understand some of the mechanical factors that might contribute to patellar component failure, a biomechanical study was performed. Quadriceps force and anterior patellar strain were measured during dynamic flexion in 10 fresh, paired human cadaver knee joints. First, tests were performed in the intact knee, followed by either posterior cruciate ligament (PCL) retention or sacrifice of TKA without patellar resurfacing. Tests were then performed following patellar resurfacing with an overly thick, optimum and thin, bony patella. Patellar strain increased in each specimen (with flexion angles of up to 80 degrees), was most pronounced as the bony patella became thinner, was closest to the intact knee when the patella was not resurfaced, and was unaffected by PCL retention or sacrifice. Patellar osteotomy, resulting in a bony patellar thickness of less than 15 mm, resulted in significantly increased strain. TKA systems should include instrumentation that allows precise restoration of overall patellar thickness while maintaining a bony patellar thickness of at least 15 mm.
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Abstract
In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
Magnetic resonance imaging (MRI) provides a noninvasive method of monitoring the pathologic response to spinal cord injury. Specific MR signal intensity patterns appear to correlate with degrees of improvement in the neurologic status in spinal cord injury patients. Histologic correlation of two types of MR signal intensity patterns are confirmed in the current study using a rat animal model. Adult male Sprague-Dawley rats underwent spinal cord trauma at the midthoracic level using a weight-dropping technique. After laminectomy, 5- and 10-gm brass weights were dropped from designated heights onto a 0.1-gm impounder placed on the exposed dura. Animals allowed to regain consciousness demonstrated variable recovery of hind limb paraplegia. Magnetic resonance images were obtained from 2 hours to 1 week after injury using a 2-tesla MRI/spectrometer. Sacrifice under anesthesia was performed by perfusive fixation; spinal columns were excised en bloc, embedded, sectioned, and observed with the compound light microscope. Magnetic resonance axial images obtained during the time sequence after injury demonstrate a distinct correlation between MR signal intensity patterns and the histologic appearance of the spinal cord. Magnetic resonance imaging delineates the pathologic processes resulting from acute spinal cord injury and can be used to differentiate the type of injury and prognosis.
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Feeding behaviour of Merino wethers under conditions similar to lot-feeding before live export. ACTA ACUST UNITED AC 1990. [DOI: 10.1071/ea9900343] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Sheep from different farms (lines) in Western Australia were mixed in 3 experiments and lot-fed for 6-7 days as if for export. A marking method to identify sheep which eat from troughs was tested and used to examine the effects of feeding treatments on the proportion of sheep which eat during lot-feeding. Paint soaked sponges attached to troughs were used to monitor whether sheep ate. Positive linear relationships between liveweight change and paint marking score (R = 0.93, 0.93 and 0.94, in the 3 experiments) suggested that the technique was a reliable indicator of feed intake. Feeding treatments imposed were period of fasting before lot feeding (experiments 2 and 3); and diet type (hay pellets, hay/pellet mix) and trough location in the feedlot (experiment 3). There were large differences between lines in the percentage of sheep not marked. Values � s.e. ranged from 1 � 1 to 79 � 3% for the 8 lines used in 3 experiments. In experiment 2, fasting for 48 h before lot-feeding resulted in more sheep (P<0.05) not marked (18 � 7 3%) than did fasting for <12 h (9 � 3%) and <24 h (8 � 2%). In experiment 3, fasting for 96 h compared with 48 h resulted in fewer sheep marked daily when fed a hay-pellet mixture (75 � 2 v. 93 � 1%; P<0.001). When fed only pellets in experiment 3, the percentages of marked sheep increased with time (days). Feeding pellets only compared with a hay-pellet mixture resulted in fewer sheep marked daily (60 � 2 v. 79 � 2%; P<0.001) and more sheep not marked (11 � 3 v. 3 � 2%; P<0.05). If troughs were located in the centre of yards instead of on the fenceline, it took 2 rather than 7 days for the daily percentage of animals marked on the pellets only diet to exceed 80%. The central location also resulted in a mean of 78 � 2% of sheep marked daily compared with 67 � 2% for fenceline troughs (P<0.001) and a mean intake higher (P<0.01) by 0.13 � 0.04 kg/wether.day. It was concluded that line of sheep, fasting, diet and trough location all had significant effects on feeding behaviour during lot feeding. Of these treatments, the greatest variation in feeding behaviour was associated with the line of sheep.
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Feed additives for attracting sheep to eat a pelleted diet during assembly for live export. ACTA ACUST UNITED AC 1988. [DOI: 10.1071/ea9880719] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The failure of some sheep to eat pelleted feed in feedlots prior to export may result in subsequent problems in their health and welfare. We investigated ways of improving feeding behaviour by adding chaffed hay or aromatic compounds to the pelleted feed. A control ration of pellets was compared with the same diet sprayed with solutions of butyric acid, aniseed oil or molasses, or fed with chaff (lucerne or oaten). Measurements of the number of sheep eating and total feed intake were made over a 10-day period. Merino wethers from 3 properties were mixed and allocated into 2 replicate groups of 39 animals per yard (1 3 m2/sheep) for each of the 6 treatments. The patterns of feed intake over time fell into 2 distinct groups. Over 70% of sheep fed pellets with either type of chaff visited the feed trough during the first 24 hours. When no chaff was fed, this level of feeding was achieved only after 4 days. All groups fed pellets without chaff showed the same pattern of feed intake, reaching a peak intake on day 3 or 4 before reducing intake until day 6 and then an increasing intake up to day 10. Little sign of this fluctuation was seen in the animals fed pellets with chaff, suggesting that, when only pellets were fed, an unstable pattern of rumen fermentation may have caused a build-up of lactic acid in the rumen and reduced feed intake. Molasses and aniseed reduced (P<0.01) the percentage of sheep per day visiting feed troughs to 5 1 and 53% respectively (6-day mean) compared with 63 and 62% for sheep on unsprayed pellets and pellets sprayed with butyric acid. Over the 10 days, intake of total feed per sheep putting its head in the trough was 1.10 kg/day for sheep fed pellets only while aniseed caused a reduction (P<0.01) to 0.85 kg/day and lucerne chaff resulted in an increase (P< 0.05) to 1.27 kg/day. There were significant differences in the eating pattern between different sources of sheep (P< 0.001) but there were no interactions between source and dietary treatments. We conclude that adding chaffed hay to the feed troughs can maximise the proportion of sheep eating from the first day in the feedlot. In addition, mixing chaffed hay with pellets on the first few days may assist the transition from roughage to cereal based diets. The use of aromatic compounds was not successful in attracting animals to the feed or in encouraging an increased intake.
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Growth responses of young Merino wethers to ad libitum feeding of oat grain mixed with either lupin seed or a urea solution. ACTA ACUST UNITED AC 1986. [DOI: 10.1071/ea9860643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Groups of 10 Merino weaners or hoggets were offered ad libitum 1 of 5 grain mixtures: oats alone (9.1% crude protein, CP), oats mixed with lupins (CP 12 or 15%), and oats sprayed with a urea solution to increase total nitrogen to an equivalent of 12 or 15% CP. In experiment 1, each grain mixture was fed with 10% milled cereal hay to sheep in pens for 98 days; in experiment 2 the sheep grazed wheat stubble for 84 days. In experiment 1, the liveweight gains of weaners and hoggets fed the lupin or urea mixtures were greater by 53-69% and 58-120�/o, respectively, than the daily 9.4 and 54.1 g/head gained on oats alone (P< 0.05). In experiment 2, liveweight gains of sheep fed these mixtures were, with 1 exception, greater by 95-1 54% than the 69.0 and 58.3 g/head gained daily by sheep fed oats alone (P< 0.05). Addition of urea to oats at the higher level (15% CP) tended to depress intake and liveweight gain, compared with the 12% CP level, and the effect was greater among hoggets. Wool production paralleled feed intake and liveweight gain. It is concluded that the daily growth rates of 90 to 130 g/head resulting from treatment of oats with up to 1.5% urea can be similar to those from oat-lupin mixes of equivalent CP (daily 85-150 g/head).
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