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1.
Am J Med Genet A ; 191(5): 1250-1260, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36760094

RESUMEN

Arteriovenous malformations (AVM) are characterized by abnormal vessels connecting arteries and veins resulting in a disruption of normal blood flow. Hereditary hemorrhagic telangiectasia (HHT) is the most common cause of pulmonary AVM characterized by a right to left shunt. Here we describe a distinct malformation where the flow of blood was from a systemic artery to the pulmonary artery (PA) resulting in a left to right shunt instead of the right to left shunt seen in individuals with HHT. This distinct malformation was identified in seven probands, one from a multiplex family containing 10 affected individuals from five generations. To identify the molecular basis of this distinct malformation, we performed exome sequencing (ES) on the seven probands and the affected paternal female cousin from the multiplex family. PhenoDB was used to prioritize candidate causative variants along with burden analysis. We describe the clinical and radiological details of the new systemic artery to PA malformation with or without pulmonary artery aneurysm (SA-PA(A)) and recommend distinct treatment techniques. Moreover, ES analysis revealed possible causative variants identified in three families with variants in a novel candidate disease gene, MCF2L. Further functional studies will be necessary to better understand the molecular mechanisms involved on SA-PA(A) malformation, however our findings suggest that MCF2L is a novel disease gene associated with SA-PA(A).


Asunto(s)
Aneurisma , Malformaciones Arteriovenosas , Telangiectasia Hemorrágica Hereditaria , Malformaciones Vasculares , Humanos , Femenino , Arteria Pulmonar/diagnóstico por imagen , Arteria Pulmonar/anomalías , Malformaciones Vasculares/genética , Telangiectasia Hemorrágica Hereditaria/diagnóstico por imagen , Telangiectasia Hemorrágica Hereditaria/genética , Aneurisma/diagnóstico por imagen , Aneurisma/genética , Factores de Intercambio de Guanina Nucleótido Rho
2.
BMC Health Serv Res ; 17(1): 291, 2017 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-28424074

RESUMEN

BACKGROUND: Project Re-Engineered Discharge (RED) is an evidence-based strategy to reduce readmissions disseminated and adapted by various health systems across the country. To date, little is known about how adapting Project RED from its original protocol impacts RED implementation and/or sustainability. The goal of this study was to identify and characterize contextual factors influencing how five California hospitals adapted and implemented RED and the subsequent impact on RED program sustainability. METHODS: Participant observation and key informant and focus group interviews with 64 individuals at five California hospitals implementing RED in 2012 and 2013 were conducted. These involved hospital leadership, personnel responsible for Project RED implementation, hospital staff, and clinicians. Interview transcripts were coded and analyzed using a modified grounded theory approach and constant comparative analysis. RESULTS: Both internal and external contextual factors were identified that influenced hospitals' decisions on RED adaptation and implementation. These also impacted RED sustainability. External factors included: impending federal penalties for hospitals with high readmission rates targeting specific diagnoses, and access to external funding and technical support to help hospitals implement RED. Internal or organizational level contextual factors included: committed leadership prioritizing Project RED; RED adaptations; depth, accountability and influence of the implementation team; sustainability planning; and hospital culture. Only three of the five hospitals continued Project RED beyond the implementation period. CONCLUSIONS: The sustainability of RED in participating hospitals was only possible when hospitals approached RED implementation as a transformational process rather than a patient safety project, maintained a high level of fidelity to the RED protocol, and had leadership and an implementation team who embraced change and failure in the pursuit of better patient care and outcomes. Hospitals who were unsuccessful in implementing a sustainable RED process lacked all or most of these components in their approach.


Asunto(s)
Hospitales , Alta del Paciente , Desarrollo de Programa , California , Grupos Focales , Humanos , Liderazgo , Innovación Organizacional , Seguridad del Paciente , Personal de Hospital , Investigación Cualitativa
3.
Sci Rep ; 6: 25665, 2016 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-27157478

RESUMEN

The objective of this study was to investigate the potential causes of high body temperature (Tb) during lactation in mice as a putative limit on energy intake. In particular we explored whether or not offspring contributed to heat retention in mothers while suckling. Tb and physical activity were monitored in 26 female MF1 mice using intraperitoneally implanted transmitters. In addition, maternal behaviour was scored each minute for 8 h d(-1) throughout lactation. Mothers that raised larger litters tended to have higher Tb while nursing inside nests (P < 0.05), suggesting that nursing offspring may have influenced heat retention. However, Tb during nursing was not higher than that recorded during other behaviours. In addition, the highest Tb during the observation period was not measured during nursing behaviour. Finally, there was no indication that mothers discontinued suckling because of a progressive rise in their Tb while suckling. Tb throughout lactation was correlated with daily increases in energy intake. Chronic hyperthermia during lactation was not caused by increased heat retention due to surrounding offspring. Other factors, like metabolic heat produced as a by-product of milk production or energy intake may be more important factors. Heat dissipation limits are probably not a phenomenon restricted to lactation.


Asunto(s)
Conducta Animal , Temperatura Corporal/fisiología , Ingestión de Energía/fisiología , Lactancia/fisiología , Animales , Animales Lactantes , Conducta Alimentaria , Femenino , Tamaño de la Camada , Ratones , Factores de Tiempo
4.
Exp Gerontol ; 86: 28-38, 2016 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-27006163

RESUMEN

Almost exactly 100years ago Osborne and colleagues demonstrated that restricting the food intake of a small number of female rats extended their lifespan. In the 1930s experiments on the impact of diet on lifespan were extended by Slonaker, and subsequently McCay. Slonaker concluded that there was a strong impact of protein intake on lifespan, while McCay concluded that calories are the main factor causing differences in lifespan when animals are restricted (Calorie restriction or CR). Hence from the very beginning the question of whether food restriction acts on lifespan via reduced calorie intake or reduced protein intake was disputed. Subsequent work supported the idea that calories were the dominant factor. More recently, however, this role has again been questioned, particularly in studies of insects. Here we review the data regarding previous studies of protein and calorie restriction in rodents. We show that increasing CR (with simultaneous protein restriction: PR) increases lifespan, and that CR with no PR generates an identical effect. None of the residual variation in the impact of CR (with PR) on lifespan could be traced to variation in macronutrient content of the diet. Other studies show that low protein content in the diet does increase median lifespan, but the effect is smaller than the CR effect. We conclude that CR is a valid phenomenon in rodents that cannot be explained by changes in protein intake, but that there is a separate phenomenon linking protein intake to lifespan, which acts over a different range of protein intakes than is typical in CR studies. This suggests there may be a fundamental difference in the responses of insects and rodents to CR. This may be traced to differences in the physiology of these groups, or reflect a major methodological difference between 'restriction' studies performed on rodents and insects. We suggest that studies where the diet is supplied ad libitum, but diluted with inert components, should perhaps be called dietary or caloric dilution, rather than dietary or caloric restriction, to distinguish these potentially important methodological differences.


Asunto(s)
Restricción Calórica , Dieta con Restricción de Proteínas , Ingestión de Energía/fisiología , Longevidad/fisiología , Animales , Femenino , Masculino , Ratones , Ratas
5.
Physiol Behav ; 154: 1-7, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26569452

RESUMEN

Lactation is one of the most energetically expensive behaviours, and trade-offs may exist between the energy devoted to it and somatic maintenance, including protection against oxidative damage. However, conflicting data exist for the effects of reproduction on oxidative stress. In the wild, a positive relationship is often observed, but in laboratory studies oxidative damage is often lower in lactating than in non-breeding animals. We hypothesised that this discrepancy may exist because during lactation food intake increases many-fold resulting in a large increase in the intake of dietary antioxidants which are typically high in laboratory rodent chow where they are added as a preservative. We supplied lactating and non-breeding control mice with either a standard or low antioxidant diet and studied how this affected the activity of endogenous antioxidants (catalase, superoxide dismutase; SOD, and glutathione peroxidise; GPx) and oxidative damage to proteins (protein carbonyls, PC) in liver and brain tissue. The low antioxidant diet did not significantly affect activities of antioxidant enzymes in brain or liver, and generally did not result in increased protein damage, except in livers of control mice on low antioxidant diet. Catalase activity, but not GPx or SOD, was decreased in both control and lactating mice on the low antioxidant diet. Lactating mice had significantly reduced oxidative damage to both liver and brain compared to control mice, independent of the diet they were given. In conclusion, antioxidant content of the diet did not affect oxidative stress in control or reproductive mice, and cannot explain the previously observed reduction in oxidative stress in lactating mammals studied in the laboratory. The reduced oxidative stress in the livers of lactating mice even under low antioxidant diet treatment was consistent with the 'shielding' hypothesis.


Asunto(s)
Antioxidantes/administración & dosificación , Lactancia/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Reproducción/efectos de los fármacos , Administración Oral , Análisis de Varianza , Animales , Índice de Masa Corporal , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Femenino , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Oxidación-Reducción/efectos de los fármacos , Carbonilación Proteica/efectos de los fármacos , Reproducción/fisiología , Superóxido Dismutasa/metabolismo , Factores de Tiempo
6.
Clin Radiol ; 71(1): 32-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26474946

RESUMEN

AIM: To evaluate the relative accuracy of contrast-enhanced time-resolved angiography with interleaved stochastic trajectories versus conventional contrast-enhanced magnetic resonance imaging (MRI) following International Society for the Study of Vascular Anomalies updated 2014-based classification of soft-tissue vascular anomalies in the head and neck in children. MATERIALS AND METHODS: Time-resolved angiography with interleaved stochastic trajectories versus conventional contrast-enhanced MRI of children with diagnosis of soft-tissue vascular anomalies in the head and neck referred for MRI between 2008 and 2014 were retrospectively reviewed. Forty-seven children (0-18 years) were evaluated. Two paediatric neuroradiologists evaluated time-resolved MRA and conventional MRI in two different sessions (30 days apart). Blood-pool endovascular MRI contrast agent gadofosveset trisodium was used. RESULTS: The present cohort had the following diagnoses: infantile haemangioma (n=6), venous malformation (VM; n=23), lymphatic malformation (LM; n=16), arteriovenous malformation (AVM; n=2). Time-resolved MRA alone accurately classified 38/47 (81%) and conventional MRI 42/47 (89%), respectively. Although time-resolved MRA alone is slightly superior to conventional MRI alone for diagnosis of infantile haemangioma, conventional MRI is slightly better for diagnosis of venous and LMs. Neither time-resolved MRA nor conventional MRI was sufficient for accurate diagnosis of AVM in this cohort. Conventional MRI combined with time-resolved MRA accurately classified 44/47 cases (94%). CONCLUSION: Time-resolved MRA using gadofosveset trisodium can accurately classify soft-tissue vascular anomalies in the head and neck in children. The addition of time-resolved MRA to existing conventional MRI protocols provides haemodynamic information, assisting the diagnosis of vascular anomalies in the paediatric population at one-third of the dose of other MRI contrast agents.


Asunto(s)
Cabeza/irrigación sanguínea , Angiografía por Resonancia Magnética/métodos , Cuello/irrigación sanguínea , Malformaciones Vasculares/diagnóstico , Adolescente , Niño , Preescolar , Medios de Contraste , Femenino , Gadolinio , Humanos , Aumento de la Imagen/métodos , Lactante , Recién Nacido , Imagen por Resonancia Magnética/métodos , Masculino , Compuestos Organometálicos
7.
Physiol Behav ; 144: 146-55, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25817538

RESUMEN

Easy access to high-energy palatable foods has been suggested to have contributed to the world-wide obesity epidemic. However, within these 'obesogenic' environments many people manage to remain lean. Mice also show variability in their weight gain responses to high-fat diet (HFD) feeding and their weight loss responses to calorically restricted (CR) feeding. In this study we investigated which factors contribute to determining susceptibility to HFD-induced obesity in mice, and whether the responses in weight gain on HFD are correlated with the responses to CR. One-hundred twenty four mice were exposed to 30% CR for 28days followed by a 14day recovery period, and subsequent exposure to 60% HFD for 28days. Responses in various metabolic factors were measured before and after each exposure (body mass; BM, body composition, food intake; FI, resting metabolic rate; RMR, physical activity, body temperature and glucose tolerance; GT). Weight changes on HFD ranged from -1 to 26%, equivalent to -0.2g to 10.5g in absolute mass. Multiple regression models showed that fat free mass (FFM) of the mice before exposure to HFD predicted 12% of the variability in weight gain on HFD (p<0.001). Also, FI during the first week of HFD feeding predicted 20% of the variability in BM and fat mass (FM) gain 4weeks later. These data may point to a role for the reward system in driving individual differences in FI and weight gain. Weight gain on the HFD was significantly negatively correlated to weight loss on CR, indicating that animals that are poor at defending against weight gain on HFD, were also poor at defending against CR-induced weight loss. Changes in FM and FFM in response to HFD or CR were not correlated however.


Asunto(s)
Temperatura Corporal/fisiología , Peso Corporal/fisiología , Dieta Alta en Grasa/efectos adversos , Obesidad/etiología , Obesidad/metabolismo , Animales , Metabolismo Basal , Composición Corporal , Restricción Calórica , Ingestión de Alimentos/fisiología , Femenino , Preferencias Alimentarias , Prueba de Tolerancia a la Glucosa , Modelos Lineales , Masculino , Ratones , Actividad Motora , Descanso , Estadísticas no Paramétricas
8.
Clin Radiol ; 69(5): 443-57, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24529409

RESUMEN

Classification of vascular anomalies (VAs) is challenging due to overlapping clinical symptoms, confusing terminology in the literature and unfamiliarity with this complex entity. It is important to recognize that VAs include two distinct entities, vascular tumours (VTs) and vascular malformations (VaMs). In this article, we describe SE Mitchell Vascular Anomalies Flow Chart (SEMVAFC), which arises from a multidisciplinary approach that incorporates clinical symptoms, physical examination and magnetic resonance imaging (MRI) findings to establish International Society for the Study of Vascular Anomalies (ISSVA)-based classification of the VAs. SEMVAFC provides a clear visual pathway for physicians to accurately diagnose Vas, which is important as treatment, management, and prognosis differ between VTs and VaMs.


Asunto(s)
Sistemas de Apoyo a Decisiones Clínicas , Imagen por Resonancia Magnética , Examen Físico , Malformaciones Vasculares/diagnóstico , Neoplasias Vasculares/diagnóstico , Femenino , Humanos , Masculino , Terminología como Asunto , Malformaciones Vasculares/clasificación , Neoplasias Vasculares/clasificación
11.
J Exp Biol ; 216(Pt 19): 3751-61, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23788704

RESUMEN

Lactating animals consume greater amounts of food than non-reproductive animals, but energy intake appears to be limited in late lactation. The heat dissipation limit theory suggests that the food intake of lactating mice is limited by the capacity of the mother to dissipate heat. Lactating mice should therefore have high body temperatures (Tb), and changes in energy intake during lactation should be reflected by variation in Tb. To investigate these predictions, 26 mice (Mus musculus) were monitored daily throughout lactation for food intake, body mass, litter size and litter mass. After weaning, 21 days postpartum, maternal food intake and body mass were monitored for another 10 days. Maternal activity and Tb were recorded every minute for 23 h a day using implanted transmitters (vital view). Energy intake increased to a plateau in late lactation (days 13-17). Daily gain in pup mass declined during this same period, suggesting a limit on maternal energy intake. Litter size and litter mass were positively related to maternal energy intake and body mass. Activity levels were constantly low, and mice with the largest increase in energy intake at peak lactation had the lowest activity. Tb rose sharply after parturition and the circadian rhythm became compressed within a small range. Tb during the light period increased considerably (1.1 ° C higher than in baseline), and lactating mice faced chronic hyperthermia, despite their activity levels in lactation being approximately halved. Average Tb increased in relation to energy intake as lactation progressed, but there was no relationship between litter size or litter mass and the mean Tb at peak lactation. These data are consistent with the heat dissipation limit theory, which suggests performance in late lactation is constrained by the ability to dissipate body heat.


Asunto(s)
Lactancia , Ratones/fisiología , Animales , Tamaño Corporal , Temperatura Corporal , Regulación de la Temperatura Corporal , Ingestión de Energía , Femenino , Tamaño de la Camada
12.
Pediatr Transplant ; 16(7): E328-31, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22489846

RESUMEN

An 18-month-old female status post-orthotopic liver transplant for biliary atresia presented nine months after transplant with severe diarrhea and intolerance of feeds. She was found to have a PLE as evidenced by a low serum albumin and a persistent elevation of fecal A1AT. Investigation eventually revealed that the cause of the PLE was a stricture at the anastomosis site between the hepatic vein and inferior cava, supported by resolution of the PLE after venoplasty of the stricture. The patient has subsequently required several repeat venoplasties for recurrence of her symptoms correlating with recurrence of the stricture. This is a very rare presentation of hepatic venous outflow obstruction. Moreover, normal duplex ultrasound imaging of liver vasculature and her unusual presentation led to a delay in her diagnosis highlighting the need for an increased index of suspicion.


Asunto(s)
Ascitis/complicaciones , Síndrome de Budd-Chiari/etiología , Diarrea/complicaciones , Fallo Hepático/complicaciones , Trasplante de Hígado/efectos adversos , Enteropatías Perdedoras de Proteínas/complicaciones , Anastomosis Quirúrgica , Ascitis/etiología , Síndrome de Budd-Chiari/complicaciones , Constricción Patológica , Diarrea/etiología , Femenino , Humanos , Lactante , Hígado/diagnóstico por imagen , Hígado/patología , Fallo Hepático/terapia , Complicaciones Posoperatorias , Enteropatías Perdedoras de Proteínas/etiología , Recurrencia , Albúmina Sérica/metabolismo , Ultrasonografía/métodos , Procedimientos Quirúrgicos Vasculares/métodos
13.
Heredity (Edinb) ; 108(1): 42-9, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22072070

RESUMEN

As important as the events that influence selection for specific chromosome types in the derivation of novel karyotypes, are the events that initiate the changes in chromosome number and structure between species, and likewise polymorphisms, variants and disease states within species. Although once thought of as transcriptional 'noise', noncoding RNAs (ncRNAs) are now recognized as important mediators of epigenetic regulation and chromosome stability. Here we highlight recent work that illustrates the influence short and long ncRNAs have as participants in the function and stability of chromosome regions such as centromeres, telomeres, evolutionary breakpoints and fragile sites. We summarize recent evidence that ncRNAs can facilitate chromosome change and present mechanisms by which ncRNAs create DNA breaks. Finally, we present hypotheses on how they may create novel karyotypes and thus affect chromosome evolution.


Asunto(s)
Cromosomas/genética , ARN no Traducido/genética , Animales , Inestabilidad Cromosómica , Puntos de Rotura del Cromosoma , Sitios Frágiles del Cromosoma , Cromosomas/metabolismo , Evolución Molecular , Humanos , Cariotipo
14.
Animal ; 5(11): 1791-804, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22440420

RESUMEN

This review brings together research findings on cervical relaxation in the ewe and its pharmacological stimulation for enhancement of the penetration needed for transcervical insemination and embryo transfer. On the basis that the success of artificial insemination is the percentage of ewes lambing, a review is made of recent research aimed at understanding and minimising the sub-lethal effects of freezing and thawing on the viability of spermatozoa, their membrane integrity and their ability to migrate through cervical mucus, as these characteristics have a major influence on fertility, particularly when semen is deposited, artificially, in the os cervix. Milestones of achievement are given for transcervical intrauterine insemination, embryo recovery and transfer and the birth of lambs of pre-determined sex, firstly following intracytoplasmic sperm injection, then laparoscopic intrauterine insemination using highly diluted flow-cytometrically sorted fresh semen and subsequently by os cervix insemination using sexed semen that had been frozen and thawed. Diversity of research endeavour (applied, cellular, molecular), research discipline (anatomy, histology, immunology, endocrinology) and research focus (cell, tissue, organ, whole animal) is embraced within the review as each has significant contributions to make in advancing recent scientific findings from the laboratory into robust on-farm transcervical insemination and embryo transfer techniques.

15.
J Bone Joint Surg Br ; 92(12): 1678-84, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21119174

RESUMEN

The results of the treatment of 31 open femoral fractures (29 patients) with significant bone loss in a single trauma unit were reviewed. A protocol of early soft-tissue and bony debridement was followed by skeletal stabilisation using a locked intramedullary nail or a dynamic condylar plate for diaphyseal and metaphyseal fractures respectively. Soft-tissue closure was obtained within 48 hours then followed, if required, by elective bone grafting with or without exchange nailing. The mean time to union was 51 weeks (20 to 156). The time to union and functional outcome were largely dependent upon the location and extent of the bone loss. It was achieved more rapidly in fractures with wedge defects than in those with segmental bone loss. Fractures with metaphyseal defects healed more rapidly than those of comparable size in the diaphysis. Complications were more common in fractures with greater bone loss, and included stiffness of the knee, malunion and limb-length discrepancy. Based on our findings, we have produced an algorithm for the treatment of these injuries. We conclude that satisfactory results can be achieved in most femoral fractures with bone loss using initial debridement and skeletal stabilisation to maintain length, with further procedures as required.


Asunto(s)
Fracturas del Fémur/cirugía , Fijación Interna de Fracturas/métodos , Fracturas Abiertas/cirugía , Adolescente , Adulto , Anciano , Algoritmos , Placas Óseas , Trasplante Óseo/métodos , Desbridamiento/métodos , Femenino , Fracturas del Fémur/diagnóstico por imagen , Estudios de Seguimiento , Fijación Intramedular de Fracturas , Curación de Fractura , Fracturas Abiertas/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Radiografía , Traumatismos de los Tejidos Blandos/cirugía , Resultado del Tratamiento , Adulto Joven
16.
J Evol Biol ; 19(4): 1183-9, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16780519

RESUMEN

To gain insight into parasite-mediated natural selection, we studied a natural population of the crustacean Daphnia magna during a severe epidemic of the bacterial parasite Pasteuria ramosa. We also investigated the relationship between susceptibility and the production of resting eggs, which are only produced during the sexual phase of reproduction. Live host samples were taken before and after this epidemic and resistance to P. ramosa was examined in the laboratory. Host clones collected after the epidemic were more resistant to P. ramosa than were those collected pre-epidemic, which is consistent with parasite-mediated selection. In our study population, asexually reproducing females were observed across the entire study period, but females carrying resting eggs were observed only prior to the epidemic. For hosts isolated in this pre-epidemic period, we found evidence that those carrying resting eggs (at the time of collection) were more susceptible than those that were reproducing asexually. This was especially apparent for measures of parasite growth, although not all measures of infection success conclusively supported this pattern. Nevertheless, the data suggest that some genotypes invest heavily in diapause at the expense of immunocompetence. Sex could therefore inhibit the evolution of resistance because each spring new genotypes will hatch from resting eggs that are relatively susceptible as they were not exposed to the previous years bout of parasite-mediated selection.


Asunto(s)
Bacillus/fisiología , Daphnia/parasitología , Selección Genética , Factores Sexuales , Animales , Femenino , Masculino
17.
Theor Appl Genet ; 111(1): 23-30, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15864526

RESUMEN

Although molecular markers and DNA sequence data are now available for many crop species, our ability to identify genetic variation associated with functional or adaptive diversity is still limited. In this study, our aim was to quantify and characterize diversity in a panel of cultivated and wild sorghums (Sorghum bicolor), establish genetic relationships, and, simultaneously, identify selection signals that might be associated with sorghum domestication. We assayed 98 simple sequence repeat (SSR) loci distributed throughout the genome in a panel of 104 accessions comprising 73 landraces (i.e., cultivated lines) and 31 wild sorghums. Evaluation of SSR polymorphisms indicated that landraces retained 86% of the diversity observed in the wild sorghums. The landraces and wilds were moderately differentiated (F st=0.13), but there was little evidence of population differentiation among racial groups of cultivated sorghums (F st=0.06). Neighbor-joining analysis showed that wild sorghums generally formed a distinct group, and about half the landraces tended to cluster by race. Overall, bootstrap support was low, indicating a history of gene flow among the various cultivated types or recent common ancestry. Statistical methods (Ewens-Watterson test for allele excess, lnRH, and F st) for identifying genomic regions with patterns of variation consistent with selection gave significant results for 11 loci (approx. 15% of the SSRs used in the final analysis). Interestingly, seven of these loci mapped in or near genomic regions associated with domestication-related QTLs (i.e., shattering, seed weight, and rhizomatousness). We anticipate that such population genetics-based statistical approaches will be useful for re-evaluating extant SSR data for mining interesting genomic regions from germplasm collections.


Asunto(s)
Variación Genética , Genética de Población , Selección Genética , Sorghum/genética , Análisis por Conglomerados , Repeticiones de Minisatélite/genética
18.
J Hered ; 93(4): 300-2, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12407221

RESUMEN

Paspalum dilatatum is a valuable forage grass in the subtropics. This species consists of several sexual (tetraploid) and apomict (penta- and hexaploid) biotypes. It has been proposed that the presence of a genome of unknown origin, the X genome, is responsible for apomixis in penta- and hexaploid biotypes. Here we evaluated the utility of random amplified polymorphic DNA (RAPD) markers for discriminating sexual and apomictic P. dilatatum biotypes. DNA samples from nine accessions, including P. intermedium, P. juergensii, and P. dilatatum (ssp. flavescens, and the common and Uruguayan biotypes) were analyzed with 86 RAPD primers. Three hundred sixty-two fragments were scored and genetic similarity estimates revealed that the penta- and hexaploid biotypes were highly similar (S(D) > or = 0.913). Forty RAPDs were unique to the penta- and hexaploid biotypes. Overall RAPD markers were useful for assessing genetic variation among closely related P. dilatatum genotypes as well as generating putative X genome markers.


Asunto(s)
Paspalum/genética , Poliploidía , Técnica del ADN Polimorfo Amplificado Aleatorio , Cartilla de ADN , Diploidia , Filogenia
19.
Reproduction ; 124(3): 409-16, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12201814

RESUMEN

Studies of cervical artificial insemination of ewes at hormone-synchronized oestrus indicate that the cervix remains relatively impenetrable to semen, in contrast to naturally breeding animals. During parturition the inflammatory response plays an important part in cervical dilation and possibly, to a lesser extent, in the non-pregnant cervix at oestrus to facilitate the transcervical transport of semen. The expression of interleukin 8 (IL-8), a pro-inflammatory cytokine in the ovine cervix, has been mapped and quantified, using semi-quantitative in situ hybridization, to ascertain the role played by inflammation in the ovine cervix during natural and artificially induced oestrous cycles. IL-8 gene expression was observed in both the luminal epithelium and fibroblastic cells of the cervix. The presence of IL-8 was confirmed using immunohistochemistry. IL-8 gene expression in the luminal epithelium varied throughout the oestrous cycle and was highest at oestrus and at day 5 of the oestrous cycle. In ewes artificially induced to ovulate, either by the withdrawal of progesterone pessaries after treatment for 12 days, or by two i.m. injections of prostaglandin 9 days apart, IL-8 gene expression at oestrus was significantly lower than it was at natural oestrus. Insemination increased IL-8 gene expression in progesterone-synchronized ewes. These data support the hypothesis that IL-8-induced inflammation is important in normal cervical function and that this process is inhibited during artificial synchronization of the oestrous cycle and is increased by exposure to semen.


Asunto(s)
Cuello del Útero/metabolismo , Interleucina-8/metabolismo , Ovinos/metabolismo , Animales , Estro/fisiología , Sincronización del Estro/métodos , Femenino , Expresión Génica , Hibridación in Situ , Inseminación Artificial , Interleucina-8/genética , Progesterona/sangre , Progesterona/farmacología , Prostaglandinas F Sintéticas/farmacología
20.
Biotechniques ; 32(2): 410, 412, 414-8, 420, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11848417

RESUMEN

During the solid-phase PCR (SP-PCR), DNA oligonucleotides complementary to a soluble template and immobilized on a surface are extended in situ. Although primarily used for pathogen detection, SP-PCR has the potential for much broader application, including disease diagnostics, genotyping, and expression studies. Current protocols for SP-PCR in microwells are suitable for enzymatic detection of immobilized products, but yields are generally insufficient for direct detection of products using conventional fluorescent probes. Here, we quantitatively measure the outcome of tethering, hybridization, and solid-phase extension, and examine the effect of composition and length of the spacer at the 5' end of tethered oligonucleotides. Our results indicate that steric hindrance primarily affects polymerase activity rather than the efficiency of hybridization between the template and the tethered oligonucleotide. SP-PCR yields are significantly higher for a five-unit hexaethyleneglycol (HEG) spacer than for the more commonly used 10-residue deoxythymidine spacer. The optimal 5' HEG spacer resulted in a 60-fold increase in extension efficiency relative to a previously reported value for SP-PCR on a glass surface. Thus, optimized spacers should allow direct quantification of SP-PCR products, providing a simple, quantitative, and cost effective means of sample analysis for a variety of applications.


Asunto(s)
Reacción en Cadena de la Polimerasa/métodos , Arabidopsis , Proteínas de Arabidopsis/genética , ADN de Plantas , Glicoles de Etileno , Hibridación de Ácido Nucleico , Fitocromo/genética , Reacción en Cadena de la Polimerasa/instrumentación
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