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151.
Panarace M Agüero JI Garrote M Jauregui G Segovia A Cané L Gutiérrez J Marfil M Rigali F Pugliese M Young S Lagioia J Garnil C Forte Pontes JE Ereno Junio JC Mower S Medina M 《Theriogenology》2007,67(1):142-151
There is considerable concern regarding the health of cloned cattle and their safety as a source of food. The objective was to summarize 5 years of commercial experience with cloning in three countries (United States, Argentina and Brazil). Overall, only 9% of transferred embryos resulted in calves; efficiency ranged from 0 to 45% (most were from 1 to 10%, but 24% of cell lines never produced live calves). There was no significant difference in pregnancy rate following transfer of one versus two embryos. Before 90 days of gestation, two ultrasound markers for embryo death were found, either crown rump length (CRL) or heart beat less than 7.5mm and 150bpm, respectively, were observed alone or together in 27% of clones that died. In addition, after 100 days of pregnancy, placental edema, hydrops fetalis and increased abdominal circumference size were used as ultrasound findings of a fetus at risk of loss. At 114 days of gestation, abdominal circumference in clones that died was statistically larger than in clones that survived alive to term and from MOET- and IVF-derived pregnancies (P<0.05). Since elective cesarean section (C-section) was partially replaced by natural or assisted parturition, C-section rates decreased from 100% in 2000 to 54% in 2005. On average, 42% of cloned calves died between delivery and 150 days of life; the most common abnormalities were: enlarged umbilical cord (37%), respiratory problems (19%), calves depressed/prolonged recumbency (20%) and contracted flexor tendons (21%). From 11 blood parameters evaluated during the first week of life, lactate decreased twice and glucose doubled its original value from 24h to 7 days. Adult cloned females had normal breeding and calving rates and cloned bulls produced good quality semen and had normal fertility when used for AI or natural mating. In conclusion, cloning had no risks qualitatively different from those encountered in animals involved in modern agricultural practices, although the frequency of the risks appeared to be increased in cattle during the early portions of the life cycle of cattle clones. 相似文献
152.
Tuberosciponoceras insolitum n. gen., n. sp. is a single dimorphic species in the Upper Albian of the Austrat Basin, southern Patagonia. The short-lived
genus was characterized by distinct ventral tubercles on all ribs and a deep, trifid internal lobe. 相似文献
153.
Phylogenetic and functional analysis of Arabidopsis RCI2 genes 总被引:3,自引:0,他引:3
Six new Arabidopsis thaliana genes (AtRCI2C-H) have been identified that show high homology to AtRCI2A and AtRCI2B. Sequence comparisons revealed that AtRCI2-related genes are widely spread among very different organisms, including other plant species, prokaryotes, fungi, and simply organized animals, and are also organized in gene families. Most RCI2 genes show a similar exon-intron organization, which indicates that they have been structurally conserved during evolution, and encode small, highly hydrophobic proteins containing two putative transmembrane domains. Consistently, the majority of AtRCI2 proteins localize in the plasma membrane. RCI2 proteins exhibit an elevated level of sequence similarity and seem to have evolved from a common ancestor. In spite of their high similarity, conserved subcellular localization, and common origin, experimental evidence is presented suggesting that different RCI2 proteins may have distinct functional roles. Thus, as previously demonstrated for AtRCI2A and AtRCI2B, the newly identified AtRCI2 genes (AtRCI2C-H) are differentially regulated in Arabidopsis organs and in response to abiotic stresses and ABA treatment. Furthermore, only the AtRCI2 proteins that do not contain the C-terminal hydrophilic tail (i.e. AtRCI2A-C and AtRCI2H) are able to complement for the loss of the yeast AtRCI2-related gene PMP3. On the basis of these results, different aspects on the evolution and roles of RCI2 genes are discussed. 相似文献
154.
Effect of testosterone on oxidative stress and cell damage induced by 3-nitropropionic acid in striatum of ovariectomized rats 总被引:4,自引:0,他引:4
Túnez I Feijóo M Collado JA Medina FJ Peña J Muñoz Mdel C Jimena I Franco F Rueda I Muntané J Montilla P 《Life sciences》2007,80(13):1221-1227
This paper evaluates the effects of testosterone (0.5 mg/kg subcutaneously (s.c.) for 8 days) on oxidative stress and cell damage induced by 3-nitropropionic acid (20 mg/kg intraperitoneally (i.p.) for 4 days) in ovariectomized rats. Gonadectomy triggered oxidative damage and cell loss, evaluated by the detection of caspase-3, whereas 3-nitropropionic acid increased the levels of oxidative stress induced by ovariectomy and prompted cell damage characterized by enhanced levels of lactate dehydrogenase. These changes were blocked by testosterone administration. Our results support the following conclusions: i) ovariectomy triggers oxidative and cell damage via caspase-3 in the striatum; ii) 3-nitropropionic acid exacerbates oxidative stress induced by ovariectomy and leads to cell damage characterized by increased levels of lactate dehydrogenase; iii) testosterone administration decreases oxidative stress and cell damage. Additionally, these data support the hypothesis that testosterone might play an important role in the onset and development of neurodegenerative diseases. 相似文献
155.
Stratifin is a member of 14-3-3 protein family, a highly conserved group of proteins constituted by seven isoforms. They are
involved in numerous crucial intracellular functions such as cell cycle and apoptosis, regulation of signal transduction pathways,
cellular trafficking, cell proliferation and differentiation, cell survival, and protein folding and processing, among others.
At epidermal level, stratifin (also called 14-3-3 sigma) has been described as molecule with relevant functions. For instance,
this isoform is a marker associated with keratinocyte differentiation. In this maturation process, the presence of dominant
negative molecules of p53 induces a “stemness condition” of keratinocyte precursor cells and suppression of stratifin expression.
In addition, the recently described keratinocyte-releasable form of stratifin is involved in dermal fibroblast MMP-1 over-expression
through c-Fos and c-Jun activity. This effect is mediated, at least in part, by p38 mitogen-activated protein kinase (MAPK).
Other MMP family members such as stromelysin-1 (MMP-3), stromelysin-2 (MMP-10), neutrophil collagenase (MMP-8), and membrane-type
MMP-24 (MT5-MMP) are also up-regulated by stratifin. Within fibroproliferative disorder of skin, hypertrophic scar and keloids
exhibit a high content of collagen, proteoglycans, and fibronectin. Thus, the MMP profile induced by stratifin is an interesting
starting point to establish new therapeutic tools to control the process of wound healing. In this review, we will focus on
site of synthesis and mode of action of stratifin in skin and wound healing. 相似文献
156.
Mitochondrial DNA and the peopling of South America 总被引:1,自引:0,他引:1
Lewis CM Lizárraga B Tito RY López PW Iannacone GC Medina A Martínez R Polo SI De La Cruz AF Cáceres AM Stone AC 《Human biology; an international record of research》2007,79(2):159-178
The initial peopling of South America is largely unresolved, in part because of the unique distribution of genetic diversity in native South Americans. On average, genetic diversity estimated within Andean populations is higher than that estimated within Amazonian populations. Yet there is less genetic differentiation estimated among Andean populations than estimated among Amazonian populations. One hypothesis is that this pattern is a product of independent migrations of genetically differentiated people into South America. A competing hypothesis is that there was a single migration followed by regional isolation. In this study we address these hypotheses using mtDNA hypervariable region 1 sequences representing 21 South American groups and include new data sets for four native Peruvian communities from Tupe, Yungay, and Puno. An analysis of variance that compared the combined data from western South America to the combined data from eastern South America determined that these two regional data sets are not significantly different. As a result, a migration from a single source population into South America serves as the simplest explanation of the data. 相似文献
157.
Johnson M Li AR Liu J Fu Z Zhu L Miao S Wang X Xu Q Huang A Marcus A Xu F Ebsworth K Sablan E Danao J Kumer J Dairaghi D Lawrence C Sullivan T Tonn G Schall T Collins T Medina J 《Bioorganic & medicinal chemistry letters》2007,17(12):3339-3343
A series of quinazolinone-derived inhibitors of the CXCR3 receptor have been synthesized and their affinity for the receptor evaluated. Compounds were evaluated in a (125)I-IP10 displacement assay and in in vitro cell migration assays to IP10, ITAC, and MIG using human peripheral blood mononuclear cells. 相似文献
158.
X. Scheldeman L. Willemen G. Coppens d’Eeckenbrugge E. Romeijn-Peeters M. T. Restrepo J. Romero Motoche D. Jiménez M. Lobo C. I. Medina C. Reyes D. Rodríguez J. A. Ocampo P. Van Damme P. Goetgebeur 《Biodiversity and Conservation》2007,16(6):1867-1884
Vasconcellea species, often referred to as highland papayas, consist of a group of fruit species that are closely related to the common
papaya (Carica papaya). The genus deserves special attention as a number of species show potential as raw material in the tropical fruit industry,
fresh or in processed products, or as genetic resources in papaya breeding programs. Some species show a very restricted distribution
and are included in the IUCN Red List. This study on Vasconcellea distribution and diversity compiled collection data from five Vasconcellea projects and retrieved data from 62 herbaria, resulting in a total of 1,553 georeferenced collection sites, in 16 countries,
including all 21 currently known Vasconcellea species. Spatial analysis of species richness clearly shows that Ecuador, Colombia and Peru are areas of high Vasconcellea diversity. Combination of species occurrence data with climatic data delimitates the potential distribution of each species
and allows the modeling of potential richness at continent level. Based on these modeled richness maps, Ecuador appears to
be the country with the highest potential Vasconcellea diversity. Despite differences in sampling densities, its neighboring countries, Peru and Colombia, possess high modeled
species richness as well. A combination of observed richness maps and modeled potential richness maps makes it possible to
identify important collection gaps. A Principal Component Analysis (PCA) of climate data at the collection sites allows us
to define climatic preferences and adaptability of the different Vasconcellea species and to compare them with those of the common papaya. 相似文献
159.
Dobrovolny J Stevens J Medina LV 《ILAR journal / National Research Council, Institute of Laboratory Animal Resources》2007,48(2):75-89
The essence of learning is change; learning is the process by which learners customize new information to make it personally meaningful and relevant. Training is the process of helping students make those changes. Research indicates that adults learn differently than children or adolescents and that adults consistently use the following six learning strategies: prior experiences; conversations; metacognition; reflection; authentic experiences; and images, pictures, or other types of visuals. Each of these learning strategies can be combined with the other strategies and often build upon each other. A recent study on how health care professionals learn indicated that the learning strategy they used most often was reflection, which supports learning before, during, and after training. Numerous examples are provided in this article describing how to integrate each of the six adult learning strategies into laboratory animal science training. While lectures and other types of direct instruction are appropriate, they are inadequate and ineffective unless they are integrated with and support adult learning strategies. Both the US Department of Agriculture regulations and the Public Health Service Policy mandate that research institutions must ensure that all personnel involved in animal care, treatment, or use are qualified to perform their duties. Applying adult learning strategies to training for the laboratory animal science community will enhance learning and improve both the science and the humane care of the animals, which is a goal our community must continuously strive to achieve. 相似文献
160.
Medina LV Hrapkiewicz K Tear M Anderson LC 《ILAR journal / National Research Council, Institute of Laboratory Animal Resources》2007,48(2):96-108
Public trust demands that individuals who do research, testing, or teaching with animals use humane, ethical, and scientifically sound methods. Furthermore, the Animal Welfare Act and the Public Health Service Policy require research institutions to provide basic training and to ensure that anyone who cares for and/or works with laboratory animals has the appropriate training or experience relevant to their job responsibilities. Institutions accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International must also provide training programs and ensure the qualifications of personnel. The primary goal of this training is to provide individuals with basic knowledge and to reinforce attitudes and behaviors that help to ensure humane animal care and use. This article provides an overview of the core training module outline and content from the 1991 report of the Institute for Laboratory Animal Research, Education and Training in the Care and Use of Laboratory Animals: A Guide for Developing Institutional Programs, as well as pertinent updates for introducing personnel to information regarding the care and use of laboratory animals. Both mandatory and suggested training topics are reviewed, including relevant regulations and standards, ethical considerations, humane methods of animal experimentation and maintenance, and other pertinent topics. Although the fundamental training course content and delivery will vary depending on the nature and complexity of an institution's animal care and use program, this basic training provides the foundation for more in-depth training programs and supports humane and ethical animal care and use. 相似文献