RESUMEN
We compared the potential of dietary lipid supplements of different fatty acid compositions to affect milk performance when early lactation dairy goats were fed a high-concentrate diet. Thirty Alpine goats at 23 ± 5 d in milk were allocated to 1 of 10 blocks according to parity and milk fat concentration. Within each block, goats were randomly assigned to receive, during a period of 41 d, either CONT) a basal diet with a forage to concentrate ratio of 45:55, used as control, or PALM) the basal diet + 2% of a palmitic acid-enriched fat supplement, or FLAX) the basal diet + 7% of extruded flaxseed. Body weight, dry matter intake and milk yield were not different between treatments. As compared with CONT, goats fed PALM and FLAX had a greater milk fat concentration. Moreover, milk fat yield was numerically (but non-significantly) greater with PALM than with CONT. Milk fat from goats receiving PALM had a greater concentration of 16:0 as compared with CONT and FLAX, whereas a greater concentration of cis-9, cis-12, cis-15 18:3 was observed when goats were fed FLAX as compared with CONT and PALM. Under the conditions of the current experiment, dietary fat supplementation had only minor impacts on the yield of major milk constituents, with the exception of a modest increase in fat yield when goats were fed PALM. The impact of a greater concentration of 16:0 in milk fat of goats receiving this feed ingredient on the nutritive value of dairy products remains to be determined.
Asunto(s)
Lino , Leche , Femenino , Animales , Ácido Palmítico , Suplementos Dietéticos , Dieta/veterinaria , Lactancia , Ácidos Grasos , Grasas de la Dieta , Cabras , Alimentación Animal/análisisRESUMEN
Improved survival rates of sick or preterm infants have resulted in an increase of observed feeding difficulties. One common method for managing feeding difficulties in infants is to manipulate liquid viscosity by adding thickening agents to formula or expressed breast milk. Concerns regarding the lack of clinical practice guidelines for the use of this strategy have been raised in the literature and in clinical settings for several years. This study aimed to survey feeding clinicians working in major Canadian pediatric centers to identify current practice patterns for use of thickened liquids in managing feeding difficulties of infants and to justify the need for standardization of this practice. A web-based pilot survey was developed using Fluidsurveys software. The questionnaire contained 37 questions targeting the process of prescribing thickeners, choice of thickener, awareness of issues, and inconsistencies raised in the literature about thickener use and how to address them. A total of 69 questionnaire responses were analyzed using descriptive statistics and inductive thematic analysis methods. Our study results indicate that thickened liquids continue to be broadly used to manage feeding difficulties in Canadian infants, despite numerous areas of concern related to their use raised by our respondents. While clear practice patterns for assessment and management were observed among the respondents, some areas of practice did not reflect recent published research or experts' opinion. Further research to develop a systematic approach for assessment, intervention, and follow-up is warranted to guide clinicians in this complex decision-making process.
Asunto(s)
Trastornos de Deglución/terapia , Trastornos de Ingestión y Alimentación en la Niñez/terapia , Dieta , Humanos , Lactante , Proyectos Piloto , Encuestas y Cuestionarios , ViscosidadRESUMEN
Mouse embryonic stem cells (mESCs) cultured in the presence of LIF occupy a ground state with highly active pluripotency-associated transcriptional and epigenetic circuitry. However, ground state pluripotency in some inbred strain backgrounds is unstable in the absence of ERK1/2 and GSK3 inhibition. Using an unbiased genetic approach, we dissect the basis of this divergent response to extracellular cues by profiling gene expression and chromatin accessibility in 170 genetically heterogeneous mESCs. We map thousands of loci affecting chromatin accessibility and/or transcript abundance, including 10 QTL hotspots where genetic variation at a single locus coordinates the regulation of genes throughout the genome. For one hotspot, we identify a single enhancer variant â¼10 kb upstream of Lifr associated with chromatin accessibility and mediating a cascade of molecular events affecting pluripotency. We validate causation through reciprocal allele swaps, demonstrating the functional consequences of noncoding variation in gene regulatory networks that stabilize pluripotent states in vitro.
Asunto(s)
Cromatina , Células Madre Pluripotentes , Animales , Diferenciación Celular , Cromatina/genética , Expresión Génica , Variación Genética , Glucógeno Sintasa Quinasa 3 , RatonesRESUMEN
BACKGROUND: To facilitate access to medical assistance in dying (MAiD) in British Columbia, telemedicine has been used for eligibility assessments. This research explored the impacts of using telemedicine on quality of care. METHODS: This mixed-methods study consisted of data from 3 BC health authorities and semistructured interviews with a patient, support persons, providers and administrators about the use of telemedicine for MAiD eligibility assessment. Interviews were conducted by telephone, video meeting or email between June and November 2018. We analyzed the quantitative data using descriptive statistics. We categorized the qualitative data using the 7 dimensions of the BC Health Quality Matrix and then analyzed them qualitatively with abductive coding. RESULTS: Twenty-one participants (8 MAiD assessors, 1 patient, 7 support persons of patients and 5 MAiD administrators) were interviewed. Telemedicine for MAiD eligibility assessments was highly acceptable to the support persons and patient and to most assessors and administrators. Assessors expressed challenges with empathy, eye contact, nonverbal communication and missing contextual factors. Participants described which patients were appropriate and which were not. Telemedicine improved access and equity for the patients who received this service. It was perceived as an effective and efficient way to perform eligibility assessments. Concerns were expressed by assessors and administrators, but not by the patient or support persons, about confidentiality. Opinions varied on the requirement for a regulated health care professional to be in physical attendance with the patient to act as a witness. INTERPRETATION: Quality of care can be achieved with telemedicine for MAiD eligibility assessments for specific situations and patients, and this modality has the potential to expand access to MAiD. Updated clinical and administrative policies are needed to address barriers to telemedicine access and to best support patients and assessors using this technology.
RESUMEN
The CRISPR-Cas9 system in bacteria and archaea has recently been exploited for genome editing in various model organisms, including mice. The CRISPR-Cas9 reagents can be delivered directly into the mouse zygote to derive a mutant animal carrying targeted genetic modifications. The major components of the system include the guide RNA, which provides target specificity, the Cas9 nuclease that creates the DNA double-strand break, and the donor oligonucleotide or plasmid carrying the intended mutation flanked by sequences homologous to the target site. Here we describe the general considerations and experimental protocols for creating genetically modified mice using the CRISPR-Cas9 system.
Asunto(s)
Sistemas CRISPR-Cas/genética , Ingeniería Genética/métodos , Genómica/métodos , Modelos Animales , Animales , Secuencia de Bases , Técnicas de Genotipaje , Ratones , Microinyecciones , Oligonucleótidos , Plásmidos/genética , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , ARN Mensajero/genética , CigotoRESUMEN
The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) system is an adaptive immune system in bacteria and archaea that has recently been exploited for genome engineering. Mutant mice can be generated in one step through direct delivery of the CRISPR/Cas9 components into a mouse zygote. Although the technology is robust, delivery remains a bottleneck, as it involves manual injection of the components into the pronuclei or the cytoplasm of mouse zygotes, which is technically demanding and inherently low throughput. To overcome this limitation, we employed electroporation as a means to deliver the CRISPR/Cas9 components, including Cas9 messenger RNA, single-guide RNA, and donor oligonucleotide, into mouse zygotes and recovered live mice with targeted nonhomologous end joining and homology-directed repair mutations with high efficiency. Our results demonstrate that mice carrying CRISPR/Cas9-mediated targeted mutations can be obtained with high efficiency by zygote electroporation.