Human neural progenitors differentiate into astrocytes and protect motor neurons in aging rats.

Age-associated health decline presents a significant challenge to healthcare, although there are few animal models that can be used to test potential treatments. Here, we show that there is a significant reduction in both spinal cord motor neurons and motor function over time in the aging rat. One explanation for this motor neuron loss could be reduced support from surrounding aging astrocytes. Indeed, we have previously shown using in vitro models that aging rat astrocytes are less supportive to rat motor neuron function and survival over time. Here, we test whether rejuvenating the astrocyte niche can improve the survival of motor neurons in an aging spinal cord. We transplanted fetal-derived human neural progenitor cells (hNPCs) into the aging rat spinal cord and found that the cells survive and differentiate into astrocytes with a much higher efficiency than when transplanted into younger animals, suggesting that the aging environment stimulates astrocyte maturation. Importantly, the engrafted astrocytes were able to protect against motor neuron loss associated with aging, although this did not result in an increase in motor function based on behavioral assays. We also transplanted hNPCs genetically modified to secrete glial cell line-derived neurotrophic factor (GDNF) into the aging rat spinal cord, as this combination of cell and protein delivery can protect motor neurons in animal models of ALS. During aging, GDNF-expressing hNPCs protected motor neurons, though to the same extent as hNPCs alone, and again had no effect on motor function. We conclude that hNPCs can survive well in the aging spinal cord, protect motor neurons and mature faster into astrocytes when compared to transplantation into the young spinal cord. While there was no functional improvement, there were no functional deficits either, further supporting a good safety profile of hNPC transplantation even into the older patient population.

A snapshot of tobacco-related messages relayed in pediatric offices in Delaware.

OBJECTIVE: Much research exists demonstrating that pediatricians should counsel patients and families about tobacco. However, few data are available about tobacco-related messages relayed in pediatric offices. Since an anti-tobacco office environment can be a strong component of an active tobacco prevention program, we evaluated pediatric offices in Delaware to characterize tobacco-related messages. METHODS: A convenience sample of 32 of 63 (51%) pediatric offices in Delaware was directly evaluated for the presence of tobacco-related messages. Fifty-five of 63 (87%) pediatric practices in Delaware were contacted by telephone to inquire about the presence of a tobacco coordinator. RESULTS: The 32 practices represented 71 physicians, were located in all three counties throughout the state, and were urban and non-urban in setting. The same investigator evaluated practices in a single site visit. All were located in smoke-free buildings. At one office, people were seen smoking outside; however, the presence of discarded cigarettes was much more common. Thirteen practices (41%) employed smokers, most of whom smoked outside during work hours. Twenty-one of 28 practices (75%) had waiting room magazines containing tobacco advertisements. Fifteen practices (47%) offered anti-tobacco literature while six practices (19%) displayed visual media, none exclusively addressing tobacco. Nine practices (28%) use chart flags to identify smokers. None of 55 pediatric practices in Delaware contacted by telephone identified an office tobacco prevention coordinator. CONCLUSIONS: Our data indicate that, in Delaware, the pediatric offices we visited overall convey a limited message about tobacco and could strengthen tobacco prevention strategies. Research measuring the impact of office-based anti-tobacco messages is needed. If these messages are effective in preventing tobacco use, practitioners can supplement active counseling with indirect interventions that require minimal maintenance once established and that place no additional demands on their time.