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Long Fibre Growth by Axons of Embryonic Mouse Hippocampal Neurons Microtransplanted into the Adult Rat Fimbria 总被引:1,自引:0,他引:1
We have described a method for the microtransplantation of a suspension of a few thousand cells from mid to late embryonic mouse hippocampi into the fimbria of immunosuppressed adult rat hosts. There was close graft-to-host contact, across a non-scarred interface. The transplanted cells included CA3 type pyramids, and were enclosed within the host myelinated fibre tract, whose glial framework was largely undisturbed. Immunohistochemistry of two species-specific markers (M6 and Thy-1.2) showed that the donor mouse neurons grew fine (<0.5 μm diameter) axons which extended singly or in fascicles through the rat host fimbria for a maximum distance of at least 10 mm. The donor axons were intimately integrated among and closely aligned to the host tract axons and to the interfascicular glial rows of the host tract. The axons travelled (i) laterally through the ipsilateral fimbria, (ii) medially across the midline in the ventral hippocampal commissure to reach the contralateral fimbria and alveus, and (iii) rostro-medially to the septum. On approaching the terminal fields appropriate to hippocampal CA3 pyramidal cell axons, the transplant axons gave rise to fine preterminal branches which were continuous with a reticular or amorphous immunoreactivity in the stratum oriens and stratum pyramidale of the ipsilateral hippocampus, and in the lateral and triangular septal nuclei. The donor axons extended along the host fimbria at a rate of ∼ 1 mm per day, reaching their terminal field destinations by ∼1–2 weeks. At 7 weeks the projections were maintained, but with little further extension. These observations indicate that the microenvironment of myelinated adult fibre tracts is permissive for an abundant and rapid growth of axons from transplanted embryonic cell suspensions. These axons can leave host tracts to invade appropriate terminal fields. 相似文献
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Erinn T Rhodes Jonathan A Finkelstein Richard Marshall Carole Allen Matthew W Gillman David S Ludwig 《Ambulatory Pediatrics》2006,6(2):110-114
OBJECTIVE: The American Diabetes Association (ADA) recommends screening children at risk for type 2 diabetes with a fasting plasma glucose test or an oral glucose tolerance test. The purpose of this study was to describe attitudes, barriers, and practices related to type 2 diabetes screening in children among pediatric clinicians. METHODS: Pediatricians, nurse practitioners and physician assistants from a multispecialty, group practice in Eastern Massachusetts completed a mailed survey. To assess screening practice, three vignettes were presented representing pediatric patients with low, moderately high, and high risk for type 2 diabetes. The moderately high-risk and high-risk patients met ADA criteria for screening. ADA-consistent practice was defined as only screening the moderately high-risk and high-risk patients; lower-threshold practice was defined as also screening the low-risk patient; and higher threshold practice was screening only the high-risk patient. RESULTS: Sixty-two of 90 clinicians responded (69%). Based on intent to screen in the 3 vignettes, 21% of respondents reported ADA-consistent screening practice, 39% lower-threshold, and 35% higher-threshold screening practice. Five percent had incomplete or nonclassifiable responses. Many clinicians ordered screening tests other than those recommended by the ADA; few (< or =8% in any vignette) ordered only an ADA-recommended test. Preferences for nonfasting tests were influenced by nonmedical factors such as access to or cost of transportation. Inadequate patient education materials and unclear recommendations for appropriate screening methods were the most frequently reported moderate/strong barriers to screening. CONCLUSIONS: Most respondents reported type 2 diabetes screening practices that differed from current ADA recommendations. Our findings suggest that type 2 diabetes screening tests must be practical for clinicians and patients if they are to be used in pediatric practice. Further study of the benefits and cost-effectiveness of type 2 diabetes screening in children is warranted to clarify the role and optimal methods for screening in pediatric primary care. 相似文献
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Tiffany M. Field Saul Schanberg Marisabel Davalos Julie Malphurs 《Early child development and care》1997,132(1):57-65
Forty normal one-month-old infants were randomly assigned to a breast-like nipple (Healthflow) bottlefeeding or a standard nipple (Evenflo) bottlefeeding group for one 20-minute feeding by the infants' mothers. The data suggested that the mothers' bottlefeeding behaviors did not differ, but the infants who fed on the breast-like nipples spent less time asleep, more time awake and active and less time fussing and crying. In addition, the vagal tone of that group decreased more during bottlefeeding and increased more after the feeding, suggesting that the breast-like nipple bottlefeedings were more similar to breastfeedings (vagal tone being lower during breastfeeding and higher after breastfeeding versus bottlefeeding). Because many women who breastfeed return to work, bottlefeeding that more closely approximate breastfeedings may ease this transition and may provide more effective supplemental feedings for the breastfed infants. 相似文献
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In this study, ethnographic interviews were used to identify first-time fathers' experiences of the birth of their first child. Fourteen fathers were interviewed, and prenatal expectations of the experience are compared with the fathers' perceptions after the birth. Although the fathers expected to be treated as part of a laboring couple, they found that they were relegated to a supporting role. Initially the fathers were confident of their ability to support their wives, but they found that labor was more work than they had anticipated. They became fearful of the outcome, but hid these fears from their partners. Later, they found that their focus moved from their wives to their babies at the time of birth. The men all completed the experience with an enhanced respect for their wives. Fathers should be included in labor management plans and need support for their role as coach, particularly when their wives experience pain. They also need to be encouraged to eat and take a break from their wives' labor when appropriate. 相似文献
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Free hydrocortisone, hydrocortisone incorporated into microspheres and empty microspheres have been administered orally to rats with carrageenan-induced hindpaw inflammation. Hydrocortisone administered in particles was effective at a lower dose than free steroid in reducing inflammation. Inflammatory exudates were able to release steroid from the microspheres by proteolytic degradation. 相似文献