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2.
Anim Reprod Sci ; 198: 99-111, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30219379

RESUMEN

Sexual development in beef bulls appears to be influenced by nutritional plane and feed efficiency. Yearling bulls fed high (GRAIN = 49) and moderate (ROUGHAGE = 109) nutritional planes, were submitted to a performance test where scrotal circumference (SC), scrotum and testis ultrasonograms and hormones were monitored throughout. Scrotal thermographs, blood cell counts and semen were evaluated at the end of the test. Residual feed intake (RFI) was the measure of feed efficiency, and bulls within each population were characterized as efficient and inefficient. During the test period, the GRAIN group had greater triiodothyronine (T3), leptin and scrotal skin thickness (SST) while having greater T3, leptin, % motile sperm, % normal sperm, scrotal temperature and values for red blood cell variables at the end of the test when compared to the ROUGHAGE group. During the test, the efficient GRAIN group had lesser testis pixel intensity while at the end of the performance test the bulls of this group had greater % normal sperm and lower testis pixel intensity compared to bulls in inefficient GRAIN group. In comparison, the efficient ROUGHAGE group had less T3, SC and SST while at the end of the test these bulls had less T3, leptin, SC, SST and scrotal temperature compared to bulls in the inefficient ROUGHAGE group. Complete blood cell variables, semen quality, scrotal biometry and thermography explained most of the variation in RFI. Results of the present study support the hypothesis that there is an antagonistic relationship between feed efficiency and sexual development in young bulls, which seems partially offset when there is a greater plane of nutrition. Thus, feed efficiency should be factored in the reproductive evaluation of sires.


Asunto(s)
Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Fertilidad/fisiología , Estado Nutricional , Análisis de Semen , Factores de Edad , Animales , Composición Corporal/fisiología , Bovinos , Rayos Infrarrojos , Masculino , Escroto/diagnóstico por imagen , Maduración Sexual/fisiología , Testículo/diagnóstico por imagen
3.
Reprod Domest Anim ; 53(3): 718-724, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29537110

RESUMEN

Emerging research suggests that the nitric oxide system may play a role in persistent breeding-induced endometritis (PBIE) in the mare. Differences in uterine nitric oxide (NO) levels between mares susceptible or resistant to PBIE and a dose-dependent inhibitory effect of NO on uterine contractility have been demonstrated. The objectives of this study were to investigate the difference in total nitric oxide synthase (NOS) activity of the endometrium between susceptible and resistant mares and the effect of a specific inducible nitric oxide synthase (iNOS) inhibitor on the endometrial NOS activity in vitro. Six susceptible and six resistant mares were selected based on preset criteria and the results of an intrauterine challenge with killed spermatozoa during oestrus. Endometrial biopsy samples were collected 24 hr post-challenge and cultured at 37°C for 24 hr in L-arginine supplemented minimum essential medium with or without a specific iNOS inhibitor (1,400 W dihydrochloride, 1 mM). The medium and the cultured endometrial tissue were collected after 24 hr of culture and assayed for NO and total protein, respectively. Total NO content of the medium, normalized to endometrial tissue wet weight or total protein, was used as a measure of endometrial NOS activity. Non-parametric tests were applied for statistical analysis. Susceptible mares had significantly greater endometrial NOS activity than resistant mares. The iNOS inhibitor treatment significantly reduced NOS activity in endometrial samples derived from susceptible and resistant mares. These findings provide a basis for in vivo testing of specific iNOS inhibitors as preventative or therapeutic options for PBIE in mares.


Asunto(s)
Susceptibilidad a Enfermedades/veterinaria , Endometritis/veterinaria , Enfermedades de los Caballos/enzimología , Óxido Nítrico Sintasa/metabolismo , Animales , Endometritis/enzimología , Endometrio/enzimología , Inhibidores Enzimáticos/farmacología , Femenino , Caballos , Masculino , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Espermatozoides
4.
Reprod Biol ; 16(2): 147-56, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27288339

RESUMEN

Fertility-associated proteins (FAP) found in seminal plasma indicate sexual maturity, which appears to be influenced by feed efficiency in cattle. This study characterized FAP via proteomics and verified associations of these proteins with feed efficiency, body composition and fertility-related measures in yearling beef bulls. Assessments including testicular ultrasonography, infrared thermography, seminal quality, seminal plasma proteomics, carcass composition, and reproductive organ biometry were obtained. From a population of 31 bulls, the seven most and least feed efficient (efficient, inefficient) bulls were used for categorical comparisons. Correlations between FAP, productive performance and fertility-related measures were determined. These traits were also correlated with orthogonal factors summarized from the FAP. Efficient bulls had increased epididymal sperm-binding protein-1 and decreased concentration of protein-C inhibitor compared to inefficient bulls. Correlations between FAP with age, body size, body composition, reproductive organ biometry, scrotal temperature, and seminiferous tubule maturity are reported. Acrosin and cathepsin D increased with development of the testes and osteopontin increased with greater numbers of mature seminiferous tubules. Phosphoglycerate kinase-2 was higher in animals with a higher scrotum temperature and a higher prevalence of sperm morphology defects. The principal factor indicated that FAP variability concentrations were positively correlated with age, reproductive organ biometry, body size and composition. Our results indicate that FAP changes with body size and sexual development, and demonstrates differences in the proteomics of bulls with diverging feed efficiency. This is related to the delay in the sexual maturity of efficient young bulls.


Asunto(s)
Ingestión de Alimentos/fisiología , Fertilidad/fisiología , Semen/metabolismo , Proteínas de Plasma Seminal/metabolismo , Testículo/fisiología , Animales , Composición Corporal/fisiología , Bovinos , Masculino , Proteómica , Testículo/diagnóstico por imagen , Ultrasonografía
5.
Animal ; 10(1): 96-105, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26351012

RESUMEN

The beef industry has emphasized the improvement of feed utilization, as measured by modeling feed intake through performance traits to calculate residual feed intake (RFI). Evidence supports an inverse relationship between feed efficiency and reproductive function. The objective of this study was to determine the relationship of reproductive assessments and RFI unadjusted (RFI(Koch)) or adjusted for body composition (RFI(us)) and the relationship among fertility-related parameters. In total, 34 crossbred bulls were housed together for 112 days of performance evaluation, followed by assessment of scrotum IR imaging, scrotal circumference, testes ultrasonography and semen quality parameters at 377±33.4 days of age. Bulls were slaughtered at 389±34.0 days of age, and analyses of carcass composition, biometrics and histomorphometry of the testis and epididymis were conducted. Bulls were grouped into two subpopulations based on divergence of RFI, and within each RFI model either by including 50% of the population (Halves, high and low RFI, n=17) or 20.6% extremes of the population (Tails, high and low RFI, n=7). The means of productive performance and fertility-related measures were compared through these categories. Pearson's correlation was calculated among fertility-related measures. In the Halves subpopulation of the RFI(us), sperm of low-RFI bulls had decreased progressive motility (47.30% v. 59.90%) and higher abundance of tail abnormalities (4.30% v. 1.80%) than that of high-RFI bulls. In the Tails subpopulation of the RFI(Koch), low RFI displayed less variation in the scrotum surface temperature (0.62°C v. 1.16°C), decreased testis echogenicity (175.50 v 198.00 pixels) and larger (60.90 v. 56.80 mm(2)) but less-developed seminiferous tubules than high-RFI bulls. The evaluation of fertility-related parameters indicated that a higher percentage of immature seminiferous tubules was correlated with occurrence of sperm with distal droplets (r=0.59), a larger temperature variation at the top of the scrotum was correlated with improved sperm progressive motility (r=0.38), a lower occurrence of sperm loose head abnormalities was correlated with larger temperature variation at the lower part of the scrotum (r=-0.43), and a lower minimum testis echogenicity (r=-0.59) and smaller scrotal circumference (r=0.72) were correlated with age. The adjustment for body composition (RFI determination) enabled distinct biological inferences about reproduction and feed efficiency when compared with the non-adjusted model. However, both RFI models and the correlation analysis supported the hypothesis that feed-efficient bulls have features of delayed sexual maturity. Overall, the assessment of fertility-related measurements is important to avoid the improvement of feed efficiency at the expense of reproductive function in young bulls.


Asunto(s)
Bovinos/fisiología , Fertilidad , Reproducción , Semen/fisiología , Maduración Sexual/fisiología , Alimentación Animal/análisis , Animales , Composición Corporal , Ingestión de Alimentos/fisiología , Masculino , Fenotipo , Escroto/anatomía & histología , Análisis de Semen/veterinaria , Espermatozoides/anomalías , Espermatozoides/fisiología , Testículo/anatomía & histología
6.
Sex Dev ; 6(1-3): 108-16, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22095250

RESUMEN

Genetic sex in mammals is determined by the sex chromosomal composition of the zygote. The X and Y chromosomes are responsible for numerous factors that must work in close concert for the proper development of a healthy sexual phenotype. The role of androgens in case of XY chromosomal constitution is crucial for normal male sex differentiation. The intracellular androgenic action is mediated by the androgen receptor (AR), and its impaired function leads to a myriad of syndromes with severe clinical consequences, most notably androgen insensitivity syndrome and prostate cancer. In this paper, we investigated the possibility that an alteration of the equine AR gene explains a recently described familial XY, SRY + disorder of sex development. We uncovered a transition in the first nucleotide of the AR start codon (c.1A>G). To our knowledge, this represents the first causative AR mutation described in domestic animals. It is also a rarely observed mutation in eukaryotes and is unique among the >750 entries of the human androgen receptor mutation database. In addition, we found another quiet missense mutation in exon 1 (c.322C>T). Transcription of AR was confirmed by RT-PCR amplification of several exons. Translation of the full-length AR protein from the initiating GTG start codon was confirmed by Western blot using N- and C-terminal-specific antibodies. Two smaller peptides (25 and 14 amino acids long) were identified from the middle of exon 1 and across exons 5 and 6 by mass spectrometry. Based upon our experimental data and the supporting literature, it appears that the AR is expressed as a full-length protein and in a functional form, and the observed phenotype is the result of reduced AR protein expression levels.


Asunto(s)
Codón Iniciador/genética , Trastornos del Desarrollo Sexual/veterinaria , Enfermedades de los Caballos/genética , Mutación/genética , Receptores Androgénicos/genética , Cromosomas Sexuales/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN/sangre , Trastornos del Desarrollo Sexual/genética , Femenino , Caballos , Masculino , Datos de Secuencia Molecular , Mutación Missense , Mutación Puntual , Receptores Androgénicos/análisis , Receptores Androgénicos/química , Alineación de Secuencia , Proteína de la Región Y Determinante del Sexo/análisis
7.
Theriogenology ; 76(8): 1540-51, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21803407

RESUMEN

Poor survival of cryopreservation by equine expanded blastocysts may involve low penetration of the embryonic capsule by cryoprotective agents (CPAs). This study characterized the permeation and accumulation rates of the CPAs ethylene glycol (EG) and glycerol (GLY) across isolated capsule in vitro, using a dual-chambered Valia-Chien permeation apparatus. Pieces of Days 14 to 18 ± 1 capsules separated media in the "donor" chamber containing either 1.5 M EG (n = 6), 0.74 M EG (n = 5), 0.87 M GLY (n = 7), or 0.15 M NaCl (saline, SAL) (n = 6), from the "recipient" chamber. Concentrations of CPA, determined by gas chromatography, allowed calculation of the capsule's apparent permeability (P(app)) to those CPAs. Permeation of capsule by 1.5 M EG was significantly more rapid than by 0.87 M GLY, or 0.74 M EG; permeation by both CPAs was significantly slower than by SAL. Accumulation of CPA in the recipient chamber depended more on initial donor chamber concentration, rather than type, of CPA. Accumulation rates for CPAs and SAL were linear only when capsule was present, demonstrating that their permeation through capsule was more complex than simple diffusion. Successful cryopreservation of equine expanded blastocysts has been previously linked to lengths of step-wise exposures to CPAs. Based on the present results, we inferred that alternative CPAs, more capable of permeating the capsule, or alternative methods of ensuring CPA entry into the cells, may also be required.


Asunto(s)
Blastocisto/efectos de los fármacos , Criopreservación/veterinaria , Crioprotectores/farmacología , Glicol de Etileno/farmacología , Glicerol/farmacología , Caballos/embriología , Animales , Blastocisto/metabolismo , Femenino , Permeabilidad
8.
Sex Dev ; 5(1): 16-25, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21196712

RESUMEN

We described the clinical, cytogenetic and molecular findings of 17 clinical equine cases presented for abnormal sexual development and infertility. Six horses with an enlarged clitoris had an XX, SRY-negative genotype, which displayed male-like behavior (adult individuals). Bilateral ovotestes were noted in 2 of those cases, while another case showed increased levels of circulating testosterone. Six horses with a female phenotype, including normal external genitalia, had an XY, SRY-negative genotype. These individuals had small gonads and an underdeveloped internal reproductive tract. Four horses with normal appearing external genitalia had an XY, SRY-positive genotype, 3 of them had hypoplastic testes and male-like behavior. In addition, one young filly with enlarged clitoris and hypoplastic testes had the same genotype but did not show male-like behavior due to her age. Three of these horses were related with 2 being siblings. These findings demonstrate the diversity of disorders of sexual development seen in the horse. Furthermore, they emphasize the need for further research to identify genes involved in abnormal sex determination and differentiation in the horse.


Asunto(s)
Trastornos del Desarrollo Sexual/veterinaria , Genes sry , Enfermedades de los Caballos/genética , Animales , Bandeo Cromosómico , Trastornos del Desarrollo Sexual/genética , Trastornos del Desarrollo Sexual/patología , Femenino , Eliminación de Gen , Genitales/anomalías , Enfermedades de los Caballos/patología , Caballos/genética , Hibridación Fluorescente in Situ , Masculino , Fenotipo , Procesos de Determinación del Sexo/genética , Diferenciación Sexual/genética
9.
Circ Res ; 86(8): 834-40, 2000 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-10785504

RESUMEN

The beta(2)-adrenergic receptor (beta(2)AR) exists in multiple polymorphic forms with different characteristics. Their relevance to heart failure (HF) physiology is unknown. Cardiopulmonary exercise testing was performed on 232 compensated HF patients with a defined beta(2)AR genotype. Patients with the uncommon Ile164 polymorphism had a lower peak VO(2) (15.0+/-0.9 mL. kg(-1). min(-1)) than did patients with Thr164 (17.9+/-0.9 mL. kg(-1). min(-1), P<0.0001). The percentage achieved of predicted peak VO(2) was also lower in patients with Ile164 (62. 3+/-4.5% versus 71.5+/-5.1%, P=0.045). The relative risk of a patient having a VO(2)

Asunto(s)
Ejercicio Físico , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/fisiopatología , Polimorfismo Genético , Receptores Adrenérgicos beta 2/genética , Alelos , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad
10.
Theriogenology ; 54(8): 1215-24, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11192180

RESUMEN

Viability of spermatozoa can be assessed by numerous methods, but many are slow and poorly repeatable, and subjectively assess only 100 to 200 spermatozoa per ejaculate. We collected two ejaculates from each of 4 stallions, and extended them to 50x10(6) sperm/mL in a nonfat dried milk solids glucose extender (EZ Mixin). Half the ejaculate was freeze-killed by immersing in liquid nitrogen for 10 min. Aliquots using appropriate volumes of live and freeze-killed spermatozoa provided the following ratios of live:dead spermatozoa: 100:0, 75:25, 50:50, 25:75, 0:100. We determined the viability of each aliquot by 1) motility; 2) eosin-nigrosin staining; and 3) dual fluorescent staining. For the latter, aliquots incubated with SYBR-14 and propidium iodide had live and dead spermatozoa quantitated by fluorescent microscope (2 x 100 sperm/sample) and flow cytometry (10,000 sperm/sample). We found a linear relationship between the ratio of live:dead spermatozoa and the percentage of spermatozoa counted as live (P<0.0001). For fresh spermatozoa, correlation coefficients of the known live:dead ratio were high for all methods (eosin-nigrosin, r>0.75; fluorescent microscope, r>0.76; flow cytometry, r>0.75; motility, r>0.76). To determine viability of cryopreserved equine spermatozoa, we froze 17 fresh ejaculates from 6 stallions in a glycine extender. Each sample was thawed, extended 1:1 with EZ Mixin and evaluated as above. Cryopreserved spermatozoa assessed by flow cytometry tended to be less well correlated (r<0.68) with the other methods, and estimates were significantly higher with eosin-nigrosin staining (P<0.001). This study shows that different methods may equally estimate viability of fresh equine spermatozoa. However, evaluation by flow cytometry appears to be less precise with cryopreserved spermatozoa.


Asunto(s)
Caballos/fisiología , Espermatozoides/fisiología , Compuestos de Anilina/química , Animales , Criopreservación/métodos , Criopreservación/veterinaria , Eosina Amarillenta-(YS)/química , Citometría de Flujo/veterinaria , Colorantes Fluorescentes/química , Masculino , Microscopía Fluorescente/veterinaria , Compuestos Orgánicos , Propidio/química , Preservación de Semen/métodos , Preservación de Semen/veterinaria , Motilidad Espermática/fisiología , Estadísticas no Paramétricas
11.
Can Vet J ; 40(12): 884-5, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10646066

RESUMEN

Segmental aplasia of the left uterine horn in a multiparous Holstein cow was diagnosed by palpation and ultrasonography. Treatment with prostaglandin was unsuccessful in eliminating the fluid from the distended uterine horn. Segmental aplasia should be included in the list of differential diagnoses for cows with nonresponsive uterine enlargement.


Asunto(s)
Enfermedades de los Bovinos/diagnóstico por imagen , Bovinos/anomalías , Enfermedades Uterinas/veterinaria , Útero/diagnóstico por imagen , Anestro , Animales , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/tratamiento farmacológico , Diagnóstico Diferencial , Resultado Fatal , Femenino , Mesonefro/diagnóstico por imagen , Prostaglandinas/uso terapéutico , Ultrasonografía , Enfermedades Uterinas/diagnóstico por imagen , Enfermedades Uterinas/tratamiento farmacológico , Útero/anomalías
12.
J Orthop Sports Phys Ther ; 24(3): 122-9, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8866270

RESUMEN

The Cyriax selective tension assessment paradigm is commonly used by clinicians for the diagnosis of soft tissue lesions; however, studies have not demonstrated that it is a valid method. The purpose of this study was to examine the construct validity of the active motion, passive motion, resisted movement, and palpation components of the Cyriax selective tension diagnosis paradigm in subjects with an exercise-induced minor hamstring muscle lesion. Nine female subjects with a mean age of 23.6 years (SD = 4.7) and a mass of 57.3 kg (SD = 10.7) performed two sets of 20 maximal eccentric isokinetic knee flexor contractions designed to induce a minor muscle lesion of the hamstrings. Active range of motion, passive range of motion, knee extension end-feel pain relative to resistance sequence, knee flexor isometric strength, pain perception during knee flexor resisted movement testing, and palpation pain of the hamstrings were assessed at 0, 5, 2, 12, 24, 48, and 72 hours postexercise and compared with Cyriax's hypothesized selective tension paradigm results. Consistent with Cyriax's paradigm, passive range of motion remained unchanged, and perceived pain of the hamstrings increased with resistance testing at 12, 24, 48, and 72 hours postexercise when compared with baseline. In addition, palpation pain of the hamstrings was significantly elevated at 48 and 72 hours after exercise (p < 0.05). In contrast of Cyriax's paradigm, active range of motion was significantly reduced over time (p < 0.05), with the least amount of motion compared to baseline (85%) occurring at 48 hours postexercise. Further, resisted movement testing found significant knee flexor isometric strength reductions over time (p < 0.05), with the greatest reductions (33%) occurring at 48 hours postexercise. According to Cyriax, when a minor muscle lesion is tested, it should be strong and painful; however, none of the postexercise time frames exhibited results that were strong and painful. This study suggests that the validity of using Cyriax's selective tension testing for the diagnosis of exercise-induced minor muscle lesions is questionable.


Asunto(s)
Músculo Esquelético/lesiones , Rango del Movimiento Articular , Traumatismos de los Tejidos Blandos/diagnóstico , Adulto , Femenino , Humanos , Inflamación , Contracción Muscular , Reproducibilidad de los Resultados , Traumatismos de los Tejidos Blandos/fisiopatología
13.
J Allergy Clin Immunol ; 97(6): 1272-8, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8648023

RESUMEN

Several lines of evidence suggest that the chemokine RANTES may play a role in eosinophilia observed during allergic inflammation. To test this hypothesis, six patients with allergic asthma were studied. After performing bronchoalveolar lavage in a lung segment (baseline), segmental bronchoprovocation was performed with saline solution in another segment and with ragweed in a third segment. Bronchoalveolar lavage was performed 24 hours later in the saline-challenged (sham) and ragweed-challenged lung segments. The bronchoalveolar lavage fluids from the baseline, sham, and ragweed segments were analyzed for cell counts and for the levels of IL-5, RANTES, and eosinophil-derived neurotoxin. IL-5 levels were elevated in the ragweed (984 +/- 588 pg/ml) compared with sham segments (2.8 +/- 0.2 pg/ml, p = 0.02). Likewise, RANTES levels were elevated in the ragweed (12.93 +/- 3.4 pg/ml) compared with the sham segments (3.05 +/- 1.19 pg/ml, p = 0.006). The IL-5 levels correlated with both eosinophil numbers (r = 0.90, p < 0.02) and eosinophil-derived neurotoxin levels (r = 0.89, p < 0.02). In contrast, RANTES levels did not correlate with either eosinophil numbers or eosinophil-derived neurotoxin levels. These results indicate that although both IL-5 and RANTES are elevated 24 hours after allergen challenge, only IL-5 correlates with eosinophil recruitment and degranulation.


Asunto(s)
Alérgenos/inmunología , Asma/inmunología , Quimiocina CCL5/fisiología , Eosinófilos/inmunología , Interleucina-5/fisiología , Adolescente , Adulto , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/citología , Degranulación de la Célula , Quimiotaxis de Leucocito , Femenino , Humanos , Recuento de Leucocitos , Masculino , Factores de Tiempo
14.
J Adolesc Health ; 18(1): 20-6, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8750424

RESUMEN

PURPOSE: The purpose of the study was to examine, among public high school students across the United States, perceptions of relative weight-loss and its relationship to physical activity levels, time spent viewing television, and efforts to lose weight. METHODS: Self-reported data from the 1990 Youth Risk Behavior Survey (YRBS) were used to analyze these relationships. The YRBS was developed and administered by the Division of Adolescent and School Health (DASH), Centers for Disease Control and Prevention (CDC), to assess important health behaviors which contribute significantly to adverse health outcomes among American youth. A total of 10,870 black, Hispanic, and white respondents were included in this analysis. RESULTS: From this sample, 24.8% perceived themselves as being "too fat." Of that group, 76.4% were trying to lose weight. Females comprised 74.4% of those reporting that they were "too fat" and trying to lose weight. Gender differences in weight perceptions were significant (p < .001), with females (34.6%) being more likely than males (14.4%) to report being "too fat." Whites (26.0%) reported being "too fat" more often than did Hispanics (23.9%) and blacks (17.2%) (p < .001). Skipping meals and exercise were the most commonly reported weight loss strategies. Hispanics were most likely to skip meals, followed by whites and blacks. Whites were more likely than the other groups to use exercise as a means of losing weight. Adolescents who perceived themselves as "too fat" reported fewer days of strenuous activity (p < .001), fewer hours of strenuous exercise in physical education class (p < .001), and more hours spent viewing television on school days (p < .001) than others. CONCLUSIONS: One quarter of U.S. high school students perceive themselves as overweight; three-quarters of these students are trying to lose weight. Adolescents who perceive themselves as overweight are less physically active and spend more time viewing television than those who do not perceive themselves as overweight.


Asunto(s)
Peso Corporal , Asunción de Riesgos , Autoimagen , Pérdida de Peso , Adolescente , Negro o Afroamericano/psicología , Negro o Afroamericano/estadística & datos numéricos , Análisis por Conglomerados , Femenino , Hispánicos o Latinos/psicología , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Masculino , Factores Sexuales , Encuestas y Cuestionarios , Estados Unidos , Población Blanca/psicología , Población Blanca/estadística & datos numéricos
15.
J Orthop Sports Phys Ther ; 22(3): 103-7, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8535466

RESUMEN

One of the side effects of corticosteroid ingestion and inhalants is suppression of the adrenal glands. Phonophoresis of topically applied corticosteroids is commonly used to treat musculoskeletal inflammatory conditions. The purpose of this study was to determine whether phonophoresis with dexamethasone sodium phosphate affected adrenal function. The subjects included 28 male volunteers (mean = 25.3 years, SD = 6.4) who received phonophoresis to the left shoulder every other day for 2 weeks. Subjects were randomly assigned to one of four groups, including a control group (N = 8), an ultrasound group (N = 8), a .33% dexamethasone group (N = 7), and a ultrasound with .33% dexamethasone group (N = 5). Adrenal function was assessed by 24-hour urinary-free cortisol (microgram cortisol/g creatinine) collected two days prior to and following the phonophoresis treatments. A nonparametric analysis of variance using a split plot factorial design was calculated for ranked urinary-free cortisol scores and found no significant (p > 0.05) differences in urinary-free cortisol levels between the four groups and between the four collection days, and there were no significant (p > 0.05) interactions exhibited between group and collection day. This study suggests that phonophoresis with dexamethasone sodium phosphate, using common clinical parameters, does not cause dexamethasone sodium phosphate to become systemic in large enough quantities to impair adrenal function.


Asunto(s)
Glándulas Suprarrenales/metabolismo , Antiinflamatorios/administración & dosificación , Dexametasona/administración & dosificación , Fonoforesis , Administración Tópica , Pruebas de Función de la Corteza Suprarrenal , Glándulas Suprarrenales/efectos de los fármacos , Adulto , Antiinflamatorios/farmacocinética , Creatinina/orina , Dexametasona/farmacocinética , Humanos , Hidrocortisona/orina , Masculino
16.
J Sch Health ; 65(6): 222-7, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7564284

RESUMEN

Data from the 1990 Youth Risk Behavior Survey were used to examine the interrelationship of drug use, sexual activity, and suicidal behavior in U.S. high school students. Findings indicated adolescents who engaged in substance use and/or sexual activity were more likely to experience suicide ideation and behavior than those who abstained from such activities. Data analysis revealed a significant and positive relationship between cocaine use and severity of outcomes of suicide attempts. Marijuana use and alcohol use were related to suicide behavior, but these relationships were not as strong as those noted for cocaine use. The study also revealed a positive relationship between frequency of sexual activity and attempted suicide, but could not determine whether such sexual activity was coerced, forced, or voluntary in nature.


Asunto(s)
Conducta del Adolescente , Conducta Sexual/psicología , Trastornos Relacionados con Sustancias/psicología , Suicidio/psicología , Adolescente , Consumo de Bebidas Alcohólicas , Cannabis , Cocaína , Análisis Factorial , Femenino , Humanos , Masculino , Factores de Riesgo , Trastornos Relacionados con Sustancias/epidemiología , Estados Unidos/epidemiología , Prevención del Suicidio
17.
J Orthop Sports Phys Ther ; 21(2): 94-9, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7711763

RESUMEN

Millions of women wear high heels on a daily basis; however, few studies have analyzed the changes high heels (positive heel inclination) have on posture. The purpose of this study was to determine whether positive heel inclination changed the postural alignment of the head, spine, pelvis, and knees. Fifteen female college students ((mean age = 22.7, SD = 3.7 years) had sagittal plane angles measured for the cervical spine, thoracic spine, lumbar spine, sacral spine, and knee joints in addition to anterior/posterior displacements of the head and pelvis. All variables were assessed by a Metrecom Skeletal Analysis System, a three-dimensional electrogoniometer. Six randomized trials, three at zero heel inclination and three at 5 cm positive heel inclination, were measured. Analysis of variance results indicated positive heel inclination of subjects brought about significantly lower anterior pelvic tilt, lumbar lordosis, and sacral base angles when compared with zero heel inclination (p < .01). Clinically, patients with low back pain may be affected by high heel usage because of the reduction of the normal lumbar lordosis.


Asunto(s)
Postura , Zapatos , Columna Vertebral/fisiología , Adulto , Femenino , Humanos , Vértebras Lumbares/fisiología , Huesos Pélvicos/fisiología , Sacro/fisiología
18.
Forensic Sci Int ; 68(2): 117-32, 1994 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-7988965

RESUMEN

The presence and location of ocular hemorrhages were prospectively studied in 169 randomly selected child deaths referred to a medical examiner. Causes of death in the study group included natural diseases and various injuries involving the head, trunk, and asphyxia. Retinal hemorrhages were identified in 70 cases: 62 head injuries, four central nervous system diseases (but not other natural diseases), and four deaths of undetermined cause. The presence of retinal, peripheral retinal, optic nerve sheath, and intrascleral hemorrhages were strongly associated with head injury as compared to other injuries and natural diseases (Yates corrected P-values < 0.001). Among the head-injured with retinal hemorrhages, nine had a history of severe traumatic event (e.g., an unrestrained rear-seat passenger in high-speed collision) and 53 were victims of inflicted injury (e.g. violent shaking). In the absence of a verifiable history of a severe head injury or life-threatening central nervous system disease, retinal and ocular hemorrhages were diagnostic of child abuse.


Asunto(s)
Causas de Muerte , Maltrato a los Niños/diagnóstico , Hemorragia Retiniana/etiología , Asfixia/diagnóstico , Asfixia/etiología , Enfermedades del Sistema Nervioso Central/diagnóstico , Niño , Maltrato a los Niños/mortalidad , Preescolar , Traumatismos Craneocerebrales/complicaciones , Traumatismos Craneocerebrales/diagnóstico , Femenino , Humanos , Lactante , Masculino , Prevalencia , Estudios Prospectivos , Hemorragia Retiniana/epidemiología , Hemorragia Retiniana/patología , Medición de Riesgo
19.
Med Sci Sports Exerc ; 26(5): 624-31, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8007812

RESUMEN

The purpose of this study was to determine if a 7-d systematic reduction in training volume or "taper" could improve distance running performance. Three groups of eight runners were examined: 1) run taper, 2) cycle taper, and 3) control. Training in the run taper group consisted of high-intensity intervals and an 85% reduction in training volume. The cycle taper group performed an equivalent amount of interval training as the run taper group, but each member exercised on a cycle ergometer. Control subjects continued normal training. A self-paced 5-km time trial served as the index of performance. The run taper group decreased 5-km time by 3% (1036.2 +/- 30.6 to 1006.8 +/- 28.2 s, P < 0.005). A significant decrease (P < 0.01) in submaximal oxygen consumption (6%) and calculated caloric expenditure (7%) at a running speed eliciting 80% of VO2max was also evident in the run taper group. Five-km performance and running economy were not altered in the cycle taper or control groups. These findings indicate that 7 d of tapered running improved distance running performance and running economy. A taper regimen of equivalent duration cycle training maintained performance in distance runners.


Asunto(s)
Resistencia Física/fisiología , Carrera/fisiología , Adulto , Umbral Anaerobio/fisiología , Ciclismo/fisiología , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Contracción Isométrica/fisiología , Pierna/fisiología , Masculino , Contracción Muscular/fisiología , Músculos/fisiología , Consumo de Oxígeno/fisiología , Estrés Mecánico , Factores de Tiempo
20.
Med Sci Sports Exerc ; 26(4): 425-31, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8201897

RESUMEN

Lipoprotein(a) [Lp(a)] is a distinct lipoprotein of the low density lipoprotein (LDL) class. Research has shown that elevated Lp(a) is an independent risk factor for coronary heart disease (CHD). The purpose of this cross-sectional study was to determine whether fitness was associated with Lp(a) concentrations. Cardiorespiratory (CR) fitness, assessed by maximal treadmill time, percent body fat (hydrodensitometry), body fat distribution (waist/hip ratio), lipoprotein profile and LDL particle size (2-16% gel electrophoresis) were determined in healthy Caucasian men (N = 100) and women (N = 50). As expected, the frequency distribution of Lp(a) was highly skewed with a mean level of 16.9 +/- 19.1 mg.dl-1 (range 0.10-90 mg.dl-1) for men and women combined. Lp(a) was only significantly (P < 0.05) correlated with cholesterol (r = 0.29) in women and LDL-C (r = 0.22) in men. However, after correcting LDL-C for Lp(a) content, the correlation was not significant (r = 0.06). A MANCOVA, controlling for age, across highest and lowest CR fitness quartiles suggest a typical positive influence of improved CR fitness on lipoproteins, body composition, and fat distribution; however, Lp(a) levels were not affected. These data indicate that there is no direct association between plasma Lp(a) and body composition, fat distribution, or CR fitness in healthy men and women.


Asunto(s)
Lipoproteína(a)/sangre , Aptitud Física/fisiología , Tejido Adiposo/anatomía & histología , Adulto , Glucemia/análisis , Presión Sanguínea/fisiología , Composición Corporal , Índice de Masa Corporal , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Enfermedad Coronaria/etiología , Enfermedad Coronaria/genética , Estudios Transversales , Electrocardiografía , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Triglicéridos/sangre
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