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1.
Vet Clin North Am Equine Pract ; 39(3): 461-474, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37574382

RESUMEN

Over the past 2 decades, equine veterinarians are turning increasingly to stem cell therapies to repair damaged tissues or to promote healing through modulation of the immune system. Research is ongoing into optimizing practices associated with stem cell product transport, dosage, and administration. Culture-expanded equine mesenchymal stem cell therapies seem safe, even when used allogeneically, but various safety concerns should be considered. Stem cells and cellular reprogramming tools hold great promise for future equine therapies.


Asunto(s)
Enfermedades de los Caballos , Células Madre Mesenquimatosas , Animales , Caballos , Enfermedades de los Caballos/terapia , Trasplante de Células Madre/efectos adversos , Trasplante de Células Madre/veterinaria
2.
Stem Cells Dev ; 32(11-12): 271-291, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36884307

RESUMEN

Induced pluripotent stem cells (iPSCs) are produced by resetting the epigenetic and transcriptional landscapes of somatic cells to express the endogenous pluripotency network and revert them back to an undifferentiated state. The reduced ethical concerns associated with iPSCs and their capacity for extensive self-renewal and differentiation make them an unparalleled resource for drug discovery, disease modeling, and novel therapies. Canines (c) share many human diseases and environmental exposures, making them a superior translational model for drug screening and investigating human pathologies compared to other mammals. However, well-defined protocols for legitimate ciPSC production are lacking. Problems during canine somatic cell reprogramming (SCR) yield putative ciPSCs with incomplete pluripotency, at very low efficiencies. Despite the value of ciPSCs, the molecular mechanisms underlying their unsuccessful production and how these may be addressed have not been fully elucidated. Factors, including cost, safety, and feasibility, may also limit the widespread clinical adoption of ciPSCs for treating canine disease. The purpose of this narrative review is to identify barriers to canine SCR on molecular and cellular levels, using comparative research to inform potential solutions to their use in both research and clinical contexts. Current research is opening new doors for the application of ciPSCs in regenerative medicine for the mutual benefit of veterinary and human medicine.


Asunto(s)
Células Madre Pluripotentes Inducidas , Animales , Perros , Humanos , Diferenciación Celular , Reprogramación Celular/genética , Mamíferos
3.
Front Vet Sci ; 9: 859025, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35591873

RESUMEN

Fetal bovine serum (FBS) remains widely used as a supplement in cell culture media used in the isolation and expansion of mesenchymal stromal cells (MSC) despite longstanding practical, clinical, and ethical concerns over its use. As a result, research on alternative culture media supplement solutions that conserve crucial MSC characteristics has become increasingly relevant. Species-specific supplements and serum-free media such as platelet lysate or chemically defined media have been assessed for their effect in MSC cultures regarding proliferation, differentiation, and immunomodulatory capacity. While none of the alternatives offer a complete solution in replacing traditional FBS supplemented media for culturing MSCs for all species, short-term or transitional use of FBS-free media can perform equally well and could address some of the concerns over the use of FBS.

5.
BMC Vet Res ; 16(1): 477, 2020 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-33292200

RESUMEN

Induced pluripotent stem cells (iPSCs) are undifferentiated stem cells characterized by the ability to differentiate into any cell type in the body. iPSCs are a relatively new and rapidly developing technology in many fields of biology, including developmental anatomy and physiology, pathology, and toxicology. These cells have great potential in research as they are self-renewing and pluripotent with minimal ethical concerns. Protocols for their production have been developed for many domestic animal species, which have since been used to further our knowledge in the progression and treatment of diseases. This research is valuable both for veterinary medicine as well as for the prospect of translation to human medicine. Safety, cost, and feasibility are potential barriers for this technology that must be considered before widespread clinical adoption. This review will analyze the literature pertaining to iPSCs derived from various domestic species with a focus on iPSC production and characterization, applications for tissue and disease research, and applications for disease treatment.


Asunto(s)
Diferenciación Celular , Células Madre Pluripotentes Inducidas/citología , Animales , Animales Domésticos , Técnicas de Cultivo de Célula/métodos , Técnicas de Cultivo de Célula/veterinaria , Células Madre Pluripotentes Inducidas/fisiología , Medicina Regenerativa/métodos , Medicina Veterinaria/métodos
6.
Front Microbiol ; 11: 606404, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33335522

RESUMEN

The emergence of "superbugs" resistant to antimicrobial medications threatens populations both veterinary and human. The current crisis has come about from the widespread use of the limited number of antimicrobials available in the treatment of livestock, companion animal, and human patients. A different approach must be sought to find alternatives to or enhancements of present conventional antimicrobials. Mesenchymal stromal cells (MSC) have antimicrobial properties that may help solve this problem. In the first part of the review, we explore the various mechanisms at work across species that help explain how MSCs influence microbial survival. We then discuss the findings of recent equine, canine, and bovine studies examining MSC antimicrobial properties in which MSCs are found to have significant effects on a variety of bacterial species either alone or in combination with antibiotics. Finally, information on the influence that various antimicrobials may have on MSC function is reviewed. MSCs exert their effect directly through the secretion of various bioactive factors or indirectly through the recruitment and activation of host immune cells. MSCs may soon become a valuable tool for veterinarians treating antimicrobial resistant infections. However, a great deal of work remains for the development of optimal MSC production conditions and testing for efficacy on different indications and species.

7.
Front Vet Sci ; 7: 584193, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33665213

RESUMEN

3D bioprinting is a rapidly evolving industry that has been utilized for a variety of biomedical applications. It differs from traditional 3D printing in that it utilizes bioinks comprised of cells and other biomaterials to allow for the generation of complex functional tissues. Bioprinting involves computational modeling, bioink preparation, bioink deposition, and subsequent maturation of printed products; it is an intricate process where bioink composition, bioprinting approach, and bioprinter type must be considered during construct development. This technology has already found success in human studies, where a variety of functional tissues have been generated for both in vitro and in vivo applications. Although the main driving force behind innovation in 3D bioprinting has been utility in human medicine, recent efforts investigating its veterinary application have begun to emerge. To date, 3D bioprinting has been utilized to create bone, cardiovascular, cartilage, corneal and neural constructs in animal species. Furthermore, the use of animal-derived cells and various animal models in human research have provided additional information regarding its capacity for veterinary translation. While these studies have produced some promising results, technological limitations as well as ethical and regulatory challenges have impeded clinical acceptance. This article reviews the current understanding of 3D bioprinting technology and its recent advancements with a focus on recent successes and future translation in veterinary medicine.

8.
Psychotherapy (Chic) ; 54(3): 273-280, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28922006

RESUMEN

The development and factor analysis of the Adventure Therapy Experience Scale (ATES) is the first attempt found in the literature to empirically and quantitatively identify therapeutic factors theorized to affect change in the adventure therapy experience (Russell & Gillis, 2017). This study utilizes the ATES to explore how its inherent factors may impact treatment outcome utilizing a routine outcome monitoring process to empirically test how these factors may contribute to treatment outcome over time. The sample of 168 males 21.5 years of age completed an average of 79.6 days in the 90-day adventure-based substance use disorder residential treatment program. In the model, adventure-based experiences are a primary treatment tool. For outcome monitoring, all clients were administered the Outcome Questionnaire (OQ-45.2) at intake, every 2 weeks, and at discharge. In addition, clients were administered the 18-item ATES every 2 weeks. The ATES contains 2 items measuring how helpful the adventure experience was as well as how mindful they were of their treatment process during the experience. Clients also answer 16 Likert items measuring responses on 4 subscales: group adventure, nature, challenge, and reflection. Results reveal that clients, on average, improved in their psycho-social functioning as measured by the OQ 45.2. Weeks with higher helpfulness, mindfulness, and group adventure scores than the client's average helpfulness, mindfulness, and group adventure score, had greater decreases in OQ scores than weeks with lower helpfulness, mindfulness, and group adventure scores. Clients with higher aggregate helpfulness and group adventure scores, across all treatment weeks, had greater decreases in OQ scores than clients with lower aggregate helpfulness and group adventure scores. Implications for practice and future research are also discussed. (PsycINFO Database Record


Asunto(s)
Psicoterapia/métodos , Tratamiento Domiciliario/métodos , Ajuste Social , Deportes/psicología , Trastornos Relacionados con Sustancias/psicología , Trastornos Relacionados con Sustancias/terapia , Adulto , Alberta , Análisis Factorial , Humanos , Masculino , Psicometría , Encuestas y Cuestionarios , Resultado del Tratamiento , Vida Silvestre , Adulto Joven
9.
F1000Res ; 6: 1618, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-30109017

RESUMEN

Throughout history, the life sciences have been revolutionised by technological advances; in our era this is manifested by advances in instrumentation for data generation, and consequently researchers now routinely handle large amounts of heterogeneous data in digital formats. The simultaneous transitions towards biology as a data science and towards a 'life cycle' view of research data pose new challenges. Researchers face a bewildering landscape of data management requirements, recommendations and regulations, without necessarily being able to access data management training or possessing a clear understanding of practical approaches that can assist in data management in their particular research domain. Here we provide an overview of best practice data life cycle approaches for researchers in the life sciences/bioinformatics space with a particular focus on 'omics' datasets and computer-based data processing and analysis. We discuss the different stages of the data life cycle and provide practical suggestions for useful tools and resources to improve data management practices.

10.
PLoS One ; 11(12): e0167442, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27907211

RESUMEN

BACKGROUND: Mesenchymal stromal cells (MSC) hold promise for both cell replacement and immune modulation strategies owing to their progenitor and non-progenitor functions, respectively. Characterization of MSC from different sources is an important and necessary step before clinical use of these cells is widely adopted. Little is known about the biology and function of canine MSC compared to their mouse or human counterparts. This knowledge-gap impedes development of canine evidence-based MSC technologies. HYPOTHESIS AND OBJECTIVES: We hypothesized that canine adipose tissue (AT) and bone marrow (BM) MSC (derived from the same dogs) will have similar differentiation and immune modulatory profiles. Our objectives were to evaluate progenitor and non-progenitor functions as well as other characteristics of AT- and BM-MSC including 1) proliferation rate, 2) cell surface marker expression, 3) DNA methylation levels, 4) potential for trilineage differentiation towards osteogenic, adipogenic, and chondrogenic cell fates, and 5) immunomodulatory potency in vitro. RESULTS: 1) AT-MSC proliferated at more than double the rate of BM-MSC (population doubling times in days) for passage (P) 2, AT: 1.69, BM: 3.81; P3, AT: 1.80, BM: 4.06; P4, AT: 2.37, BM: 5.34; P5, AT: 3.20, BM: 7.21). 2) Canine MSC, regardless of source, strongly expressed cell surface markers MHC I, CD29, CD44, and CD90, and were negative for MHC II and CD45. They also showed moderate expression of CD8 and CD73 and mild expression of CD14. Minor differences were found in expression of CD4 and CD34. 3) Global DNA methylation levels were significantly lower in BM-MSC compared to AT-MSC. 4) Little difference was found between AT- and BM-MSC in their potential for adipogenesis and osteogenesis. Chondrogenesis was poor to absent for both sources in spite of adding varying levels of bone-morphogenic protein to our standard transforming growth factor (TGF-ß3)-based induction medium. 5) Immunomodulatory capacity was equal regardless of cell source when tested in mitogen-stimulated lymphocyte reactions. Priming of MSC with pro-inflammatory factors interferon-gamma and/or tumour necrosis factor did not increase the lymphocyte suppressive properties of the MSC compared to untreated MSC. CONCLUSIONS/SIGNIFICANCE: No significant differences were found between AT- and BM-MSC with regard to their immunophenotype, progenitor, and non-progenitor functions. Both MSC populations showed strong adipogenic and osteogenic potential and poor chondrogenic potential. Both significantly suppressed stimulated peripheral blood mononuclear cells. The most significant differences found were the higher isolation success and proliferation rate of AT-MSC, which could be realized as notable benefits of their use over BM-MSC.


Asunto(s)
Tejido Adiposo/citología , Células de la Médula Ósea/citología , Diferenciación Celular/genética , Células Madre Mesenquimatosas/citología , Adipogénesis/genética , Tejido Adiposo/crecimiento & desarrollo , Tejido Adiposo/metabolismo , Animales , Células de la Médula Ósea/metabolismo , Proliferación Celular , Células Cultivadas , Condrogénesis/genética , Perros , Humanos , Células Madre Mesenquimatosas/metabolismo , Ratones , Osteogénesis/genética
11.
Psychotherapy (Chic) ; 53(4): 413-423, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27064927

RESUMEN

We examine aspects of engagement (MacKenzie, 1983) as predictors of longitudinal change in Outcome Questionnaire-45.2 scores (Lambert, Kahler, Harmon, Burlingame, & Shimokawa, 2011) for 68, 18-24-year-old male residents in a 10-bed, open enrollment 90-day residential, substance use treatment program. Engagement was partitioned into within-member, between-member, within-other members, and between-other members' effects. Within-member engagement represented how a group member's score for a week deviated from that member's average engagement score (across all weeks), whereas between-member engagement was the member's average engagement score. Similarly, within-other member engagement represented how the other group members' scores for a week deviated from the other group members' average engagement score (across all weeks), whereas between-other member engagement was the other group members' average engagement score. A 2-level hierarchical linear model showed the interaction of between-member engagement and between-other member engagement was related to decreasing OQ-45 scores. When other group members generally saw the group as more engaged, higher group member average engagement ratings were related to improvement. There was a significant interaction between within-member engagement and between-member engagement in predicting OQ-45 scores. When clients generally saw the group as more engaged, weeks with relatively more member engagement, compared with other weeks, were associated with improvement in OQ-45 scores. However, when clients generally saw the group as less engaged, weeks with relatively more group member engagement, compared with other weeks, were associated with greater deterioration in OQ scores. We recommend tracking week-to-week changes in member and other member engagement to identify group members who are not getting optimal program benefits. (PsycINFO Database Record


Asunto(s)
Individualidad , Relaciones Interpersonales , Evaluación de Resultado en la Atención de Salud , Psicoterapia de Grupo/métodos , Tratamiento Domiciliario , Trastornos Relacionados con Sustancias/rehabilitación , Vida Silvestre , Adolescente , Terapia Combinada , Procesos de Grupo , Humanos , Estudios Longitudinales , Masculino , Apego a Objetos , Trastornos Relacionados con Sustancias/psicología , Encuestas y Cuestionarios , Adulto Joven
12.
BMC Vet Res ; 12: 45, 2016 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-26952099

RESUMEN

BACKGROUND: Recently, equine multipotent mesenchymal stromal cells (MSC) have received significant attention as therapy for various conditions due to their proposed regenerative and immune-modulating capacity. MSC are commonly administered to the patient through a hypodermic needle. Currently, little information is available on the effect of such injection has on equine MSC immediate and delayed viability. We hypothesize that viability of equine MSC is not correlated with needle diameter during aspiration and injection. RESULTS: Using a 3 mL syringe, manual injection of equine cord blood (CB) or bone marrow-derived (BM) MSC with no needle and needles ranging in size from 18 to 30 Ga did not affect immediate MSC viability. Similarly, 24 h post-injection, MSC delayed viability was not different between any of the tested needles as determined by a resazurin-based proliferation assay. Using a 3 mL syringe, aspiration of MSC through 20, 25, and 30 Ga needles resulted in significant decreases in immediate viability with no change in delayed viability when compared to aspiration without a needle. BM- and CB-MSC were observed to be of similar size with a diameter ± SD of 19.8 ± 2.7 and 20.4 ± 2.2 µm, respectively. In comparison, the smallest needles, (30 Ga) have an internal diameter of 160 µm. CONCLUSIONS: Following injection, needle diameter did not affect immediate or delayed viability of equine MSC. Following aspiration through needles sizes 20 Ga and smaller, immediate viability, but not delayed viability, decreased. As a result, an 18 Ga or larger needle should be utilized for aspiration of cell suspensions. In contrast, needle selection for MSC injection should be based on clinical preference and experience rather than concerns over decreasing MSC viability.


Asunto(s)
Supervivencia Celular , Células Madre Mesenquimatosas , Agujas , Animales , Células Cultivadas , Caballos , Inyecciones/instrumentación , Inyecciones/métodos
13.
PLoS One ; 10(9): e0136621, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26353112

RESUMEN

BACKGROUND: Mesenchymal stromal cells (MSC) are increasingly investigated for their clinical utility in dogs. Fetal bovine serum (FBS) is a common culture supplement used for canine MSC expansion. However, FBS content is variable, its clinical use carries risk of an immune response, and its cost is increasing due to global demand. Platelet lysate (PL) has proven to be a suitable alternative to FBS for expansion of human MSC. HYPOTHESIS AND OBJECTIVES: We hypothesized that canine adipose tissue (AT) and bone marrow (BM) MSC could be isolated and expanded equally in PL and FBS at conventionally-used concentrations with differentiation of these MSC unaffected by choice of supplement. Our objectives were to evaluate the use of canine PL in comparison with FBS at four stages: 1) isolation, 2) proliferation, 3) spontaneous differentiation, and 4) directed differentiation. RESULTS: 1) Medium with 10% PL was unable to isolate MSC. 2) MSC, initially isolated in FBS-supplemented media, followed a dose-dependent response with no significant difference between PL and FBS cultures at up to 20% (AT) or 30% (BM) enrichment. Beyond these respective peaks, proliferation fell in PL cultures only, while a continued dose-dependent proliferation response was noted in FBS cultures. 3) Further investigation indicated PL expansion culture was inducing spontaneous adipogenesis in concentrations as low as 10% and as early as 4 days in culture. 4) MSC isolated in FBS, but expanded in either FBS or PL, maintained ability to undergo directed adipogenesis and osteogenesis, but not chondrogenesis. CONCLUSIONS/SIGNIFICANCE: Canine PL did not support establishment of MSC colonies from AT and BM, nor expansion of MSC, which appear to undergo spontaneous adipogenesis in response to PL exposure. In vivo studies are warranted to determine if concurrent use of MSC with any platelet-derived products such as platelet-rich plasma are associated with synergistic, neutral or antagonistic effects.


Asunto(s)
Tejido Adiposo/citología , Células de la Médula Ósea/citología , Técnicas de Cultivo de Célula/métodos , Medios de Cultivo , Células Madre Mesenquimatosas/citología , Animales , Bovinos , Proliferación Celular , Perros , Plasma Rico en Plaquetas
14.
Ochsner J ; 13(3): 394-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24052771

RESUMEN

BACKGROUND: Residents and fellows perform a large portion of the hands-on patient care in tertiary referral centers. As frontline providers, they are well suited to identify quality and patient safety issues. As payment reform shifts hospitals to a fee-for-value-type system with reimbursement contingent on quality outcomes, preventive health, and patient satisfaction, house staff must be intimately involved in identifying and solving care delivery problems related to quality, outcomes, and patient safety. Many challenges exist in integrating house staff into the quality improvement infrastructure; these challenges may ideally be managed by the development of a house staff quality council (HSQC). METHODS: Residents and fellows at Scott & White Memorial Hospital interested in participating in a quality council submitted an application, curriculum vitae, and letter of support from their program director. Twelve residents and fellows were selected based on their prior quality improvement experience and/or their interest in quality and safety initiatives. RESULTS: In only 1 year, our HSQC, an Alliance of Independent Academic Medical Centers National Initiative III project, initiated 3 quality projects and began development of a fourth project. CONCLUSION: Academic medical centers should consider establishing HSQCs to align institutional quality goals with residency training and medical education.

15.
Sports Med ; 43(9): 783-802, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23743792

RESUMEN

Short stature and later maturation of youth artistic gymnasts are often attributed to the effects of intensive training from a young age. Given limitations of available data, inadequate specification of training, failure to consider other factors affecting growth and maturation, and failure to address epidemiological criteria for causality, it has not been possible thus far to establish cause-effect relationships between training and the growth and maturation of young artistic gymnasts. In response to this ongoing debate, the Scientific Commission of the International Gymnastics Federation (FIG) convened a committee to review the current literature and address four questions: (1) Is there a negative effect of training on attained adult stature? (2) Is there a negative effect of training on growth of body segments? (3) Does training attenuate pubertal growth and maturation, specifically, the rate of growth and/or the timing and tempo of maturation? (4) Does training negatively influence the endocrine system, specifically hormones related to growth and pubertal maturation? The basic information for the review was derived from the active involvement of committee members in research on normal variation and clinical aspects of growth and maturation, and on the growth and maturation of artistic gymnasts and other youth athletes. The committee was thus thoroughly familiar with the literature on growth and maturation in general and of gymnasts and young athletes. Relevant data were more available for females than males. Youth who persisted in the sport were a highly select sample, who tended to be shorter for chronological age but who had appropriate weight-for-height. Data for secondary sex characteristics, skeletal age and age at peak height velocity indicated later maturation, but the maturity status of gymnasts overlapped the normal range of variability observed in the general population. Gymnasts as a group demonstrated a pattern of growth and maturation similar to that observed among short-, normal-, late-maturing individuals who were not athletes. Evidence for endocrine changes in gymnasts was inadequate for inferences relative to potential training effects. Allowing for noted limitations, the following conclusions were deemed acceptable: (1) Adult height or near adult height of female and male artistic gymnasts is not compromised by intensive gymnastics training. (2) Gymnastics training does not appear to attenuate growth of upper (sitting height) or lower (legs) body segment lengths. (3) Gymnastics training does not appear to attenuate pubertal growth and maturation, neither rate of growth nor the timing and tempo of the growth spurt. (4) Available data are inadequate to address the issue of intensive gymnastics training and alterations within the endocrine system.


Asunto(s)
Desarrollo del Adolescente , Desarrollo Infantil , Gimnasia/fisiología , Acondicionamiento Físico Humano/fisiología , Esfuerzo Físico/fisiología , Adolescente , Estatura , Peso Corporal , Niño , Femenino , Hormonas/sangre , Humanos , Extremidad Inferior/crecimiento & desarrollo , Masculino , Estado Nutricional , Acondicionamiento Físico Humano/efectos adversos , Pubertad , Maduración Sexual , Torso/crecimiento & desarrollo
16.
J Org Chem ; 73(2): 474-84, 2008 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-18085794

RESUMEN

Three new isomeric dipyridoannulenes were synthesized and characterized. These molecules possess differing conjugation pathways between the substituent alkoxy donating groups and the pyridyl acceptor groups. Optical absorption and emission properties of the dipyridoannulenes and their corresponding acyclic precursors were measured and correlated to structural differences and used to evaluate conjugation effectiveness and charge-transfer pathways. Optical properties of protonated dipyridoannulenes were also measured and found to be somewhat insensitive to the degree of protonation. Density functional studies of these systems at the B3LYP/6-31G* level provided insight into their stabilities, polarities, and quinoidal character. An analysis of the HOMO and LUMO molecular orbitals provided further information regarding charge-transfer behavior. These systems are good metal binding candidates, as the pyridine moiety can act as both an electron-acceptor and a site for metal coordination.

17.
J Sports Sci ; 25(8): 879-86, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17474041

RESUMEN

The aim of this study was to examine the relationships among biological maturity, physical size, relative age (i.e. birth date), and selection into a male Canadian provincial age-banded ice hockey team. In 2003, 619 male ice hockey players aged 14-15 years attended Saskatchewan provincial team selection camps, 281 of whom participated in the present study. Data from 93 age-matched controls were obtained from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-1997). During the initial selection camps, birth dates, heights, sitting heights, and body masses were recorded. Age at peak height velocity, an indicator of biological maturity, was determined in the controls and predicted in the ice hockey players. Data were analysed using one-way analysis of variance, logistic regression, and a Kolmogorov-Smirnov test. The ice hockey players selected for the final team were taller, heavier, and more mature (P < 0.05) than both the unselected players and the age-matched controls. Furthermore, age at peak height velocity predicted (P < 0.05) being selected at the first and second selection camps. The birth dates of those players selected for the team were positively skewed, with the majority of those selected being born in the months January to June. In conclusion, team selectors appear to preferentially select early maturing male ice hockey players who have birth dates early in the selection year.


Asunto(s)
Envejecimiento , Aptitud , Hockey , Adolescente , Tamaño Corporal , Niño , Humanos , Masculino , Selección de Personal , Saskatchewan
18.
J Med Chem ; 47(3): 519-29, 2004 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-14736234

RESUMEN

We have previously described a series of antagonists that showed high potency and selectivity for the NK(1) receptor. However, these compounds also had the undesirable property of existing as a mixture of interconverting rotational isomers. Here we show that alteration of the 2-naphthyl substituent can modulate the rate of isomer exchange. Comparisons of the NK(1) receptor affinity for the various conformational forms has facilitated the development of a detailed NK(1) pharmacophore model.


Asunto(s)
Naftalenos/síntesis química , Antagonistas del Receptor de Neuroquinina-1 , Animales , Disponibilidad Biológica , Encéfalo/metabolismo , Línea Celular Tumoral , Perros , Gerbillinae , Humanos , Técnicas In Vitro , Espectroscopía de Resonancia Magnética , Ratones , Modelos Moleculares , Naftalenos/química , Naftalenos/farmacología , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/metabolismo , Conejos , Ensayo de Unión Radioligante , Receptores de Neuroquinina-1/química , Receptores de Neuroquinina-1/metabolismo , Estereoisomerismo , Relación Estructura-Actividad
19.
Med Sci Sports Exerc ; 35(3): 513-8, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12618584

RESUMEN

INTRODUCTION/PURPOSE: The role of impact loading activity on bone mass is well established; however, there are little data on the effects of exercise on bone geometry and indices of bone strength. The primary purpose of this study was to compare indices of bone strength at the proximal femur (PF) between elite premenarcheal gymnasts (N= 30) and age-matched controls (N= 30). METHODS: Structural properties of the proximal femur were derived from the hip analyses program and included measurement of subperiosteal width, endosteal diameter, cross-sectional area, bone mineral density, cross-section moment of inertia (CSMI), and section modulus (Z). These parameters were measured for two regions of the PF: the narrow neck (NN), and the shaft (S). In addition, a strength index (S-SI) was calculated at the shaft by dividing the Z at the shaft by the femur length. A secondary purpose was to compare bone mineral content (BMC) values at the total body, lumbar spine, and three sites at the PF (neck, trochanter, and total) between the groups. All dependent values were compared adjusting for height and weight using an ANCOVA procedure and for relative lean body mass. RESULTS The gymnasts had significantly greater size-adjusted strength indices (CSMI, Z, and SI) at the NN and S. Gymnasts also had significantly greater size-adjusted BMC at all sites investigated. However, these differences disappeared when adjusted for relative lean body mass. CONCLUSION: When adjusted for body size, gymnasts had significantly greater indices of both axial strength and bending strength at the NN region of the PF and S, as well as a greater bone SI at the femoral shaft. These differences may be related to greater relative lean body mass attained in gymnastics training.


Asunto(s)
Fémur/fisiología , Gimnasia/fisiología , Pubertad/fisiología , Resistencia a la Tracción/fisiología , Adolescente , Antropometría , Constitución Corporal/fisiología , Peso Corporal/fisiología , Densidad Ósea/fisiología , Niño , Femenino , Humanos , Actividad Motora/fisiología , Salud de la Mujer
20.
J Med Chem ; 45(18): 3972-83, 2002 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-12190319

RESUMEN

Through optimization of compounds based on the dual NK(1)/NK(2) antagonist ZD6021, it was found that alteration of two key regions could modulate the balance of NK(1) and NK(2) potency. Substitution of the 2-naphthalene position in analogues of ZD6021 resulted in increased NK(1) potency and thus afforded NK(1) preferential antagonists. Alterations of the piperidine region could then increase NK(2) potency to restore dual NK(1)/NK(2) selectivity. Through these efforts, three novel receptor antagonists from a single chemically related series were identified; two are dual NK(1)/NK(2) antagonists, and the third is an NK(1) preferential antagonist. In this paper, the factors affecting the balance of NK(1) and NK(2) selectivity in this series are discussed and the in vitro and in vivo properties of the novel antagonists are described.


Asunto(s)
Antagonistas del Receptor de Neuroquinina-1 , Piperidinas/síntesis química , Receptores de Neuroquinina-2/antagonistas & inhibidores , Sulfóxidos/síntesis química , Taquicininas/antagonistas & inhibidores , Animales , Disponibilidad Biológica , Perros , Piperidinas/química , Piperidinas/farmacocinética , Piperidinas/farmacología , Ratas , Relación Estructura-Actividad , Sulfóxidos/farmacocinética , Sulfóxidos/farmacología
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