Superparamagnetic iron oxide labeling and transplantation of adipose-derived stem cells in middle cerebral artery occlusion-injured mice.

OBJECTIVE: Adipose-derived stem cells are an alternative stem cell source for CNS therapies. The goals of the current study were to label adipose-derived stem cells with superparamagnetic iron oxide (SPIO) particles, to use MRI to guide the transplantation of adipose-derived stem cells in middle cerebral artery occlusion (MCAO)-injured mice, and to localize donor adipose-derived stem cells in the injured brain using MRI. We hypothesized that we would successfully label adipose-derived stem cells and image them with MRI. MATERIALS AND METHODS: Adipose-derived stem cells harvested from mice inbred for green fluorescent protein were labeled with SPIO ferumoxide particles through the use of poly-L-lysine. Adipose-derived stem cell viability, iron staining, and proliferation were measured after SPIO labeling, and the sensitivity of MRI in the detection of SPIO-labeled adipose-derived stem cells was assessed ex vivo. Adult mice (n = 12) were subjected to unilateral MCAO. Two weeks later, in vivo 7-T MRI was performed to guide stereotactic transplantation of SPIO-labeled adipose-derived stem cells into brain tissue adjacent to the infarct. After 24 hours, the mice were sacrificed for high-resolution ex vivo 7-T or 9.4-T MRI and histologic study. RESULTS: Adipose-derived stem cells were efficiently labeled with SPIO particles without loss of cell viability or proliferation. Using MRI, we guided precise transplantation of adipose-derived stem cells. MR images of mice given injections of SPIO-labeled adipose-derived stem cells had hypointense regions that correlated with the histologic findings in donor cells. CONCLUSION: MRI proved useful in transplantation of adipose-derived stem cells in vivo. This imaging technique may be useful for studies of CNS stem cell therapies.

Stem cell therapy for neurologic disorders: therapeutic potential of adipose-derived stem cells.

There is growing evidence to suggest that reservoirs of stem cells may reside in several types of adult tissue. These cells may retain the potential to transdifferentiate from one phenotype to another, presenting exciting possibilities for cellular therapies. Recent discoveries in the area of neural differentiation are particularly exciting given the limited capacity of neural tissue for intrinsic repair and regeneration. Adult adipose tissue is a rich source of mesenchymal stem cells, providing an abundant and accessible source of adult stem cells. These cells have been termed adipose derived stem cells (ASC). The characterization of these ASCs has defined a population similar to marrow-derived and skeletal muscle-derived stem cells. The success seen in differentiating ASC into various mesenchymal lineages has generated interest in using ASC for neuronal differentiation. Initial in vitro studies characterized the morphology and protein expression of ASC after exposure to neural induction agents. Additional in vitro data suggests the possibility that ASCs are capable of neuronal activity. Progress in the in vitro characterization of ASCs has led to in vivo modeling to determine the survival, migration, and engraftment of transplanted ASCs. While work to define the mechanisms behind the transdifferentiation of ASCs continues, their application to neurological diseases and injuries should also progress. The subject of this review is the capacity of adipose derived stem cells (ASC) for neural transdifferentiation and their application to the treatment of various neurologic disorders.

A cost and outcomes comparison of a novel integrated pediatric air and ground transportation system.

BACKGROUND: The purpose of this study is to compare air transportation of critically ill pediatric patients with a mixed air-ground transportation system by evaluating timeliness, safety, and cost. The setting was a tertiary care "hub" center with three outlying-referral "spoke" facilities. STUDY DESIGN: Our study included 96 children transported between June and December 1997, with 45% constituting surgical admissions and 55% medical admissions. Data collected at the outlying facilities, en route, and at our institution included vital signs, laboratory values, and Glasgow coma scores. We evaluated transport time, transport cost, Pediatric Risk of Mortality scores, and Pediatric Index of Mortality of the children during transportation using ANOVA statistical analysis. We also compared adverse events in transportation, total hospital length of stay, and mortality at 24 and 72 hours in both the air and ground transport groups to determine differences in predicted and observed mortality. RESULTS: A total of 96 children were transported (48% by ground and 52% by air) between June and December 1997. The time at the referring facility was significantly shorter in the ground group than in the air group (air, 55.4 minutes versus ground, 36.7 minutes, p < 0.01). Total transport time differed by only 27 minutes between groups. No difference was identified in morbidity or mortality between air and ground groups. Actual mortality was not significantly different from predicted mortality in either group. The cost of ground transportation was significantly lower (air, $4,236 versus ground, $1,566). When our system of a combined air and ground group transport system is compared with a hypothetical 100% air transport system, we saved an average of more than $240,000 annually. CONCLUSIONS: We have demonstrated that a "hub-and-spoke" ground transportation system supplements air transportation in a safe, timely, and cost-effective manner.

A study of 11,003 patients with hypertrophic pyloric stenosis and the association between surgeon and hospital volume and outcomes.

AIM: The availability of large clinical databases allows for careful evaluation of surgical practices, indicators of quality improvement, and cost. We used a large clinical database to compare the effect of surgeon and hospital volume for the care of children with hypertrophic pyloric stenosis (HPS). METHODS: Patients with International Classification of Diseases-9 codes for HPS and pyloromyotomy were selected from the 1994 to 2000 National Inpatient Samples database. Multiple and logistic regression models were used to evaluate the risk-adjusted association between provider volume and outcomes. RESULTS: Postoperative complications occurred in 2.71% of patients. Patients operated on by low- and intermediate-volume surgeons were more likely to have complications compared with those operated on by high-volume surgeons (95% confidence interval [CI], 1.25-3.78 and 95% CI, 1.25-2.69, respectively). Patients operated at low-volume hospitals were 1.6 times more likely to have complications compared with those operated at intermediate- or high-volume hospitals (95% CI, 1.19-2.20). Procedures performed at high-volume hospitals were less expensive than those at intermediate-volume hospitals by a margin of 910 dollars (95% CI, 443-1377 dollars). CONCLUSIONS: These data represent the largest study to date on the epidemiology, complication rate, and cost for care for HPS. Patients treated by both high-volume surgeons and at high-volume hospitals have improved outcomes at less cost.

Distinct hematopoietic progenitor compartments are delineated by the expression of aldehyde dehydrogenase and CD34.

A broad range of hematopoietic stem cells and progenitors reside within a fraction of umbilical cord blood (UCB) that exhibits low light scatter properties (SSC(lo)) and high expression of aldehyde dehydrogenase (ALDH(br)). Many SSC(lo) ALDH(br) cells coexpress CD34; however, other cells express either ALDH or CD34. To investigate the developmental potential of these cell subsets, purified ALDH(br) CD34+, ALDH(neg) CD34+, and ALDH(br) CD34(neg) UCB cells were characterized within a variety of in vivo and in vitro assays. Primitive progenitors capable of multilineage development were monitored in long- and short-term repopulation assays performed on nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice, and in primary and secondary long-term culture assays. These progenitors were highly enriched within the ALDH(br) CD34+ fraction. This cell fraction also enriched short-term myeloid progenitors that were detected in vitro. By comparison, ALDH(neg) CD34+ cells contained few primitive progenitors and had diminished short-term myeloid potential but exhibited enhanced short-term natural killer (NK) cell development in vitro. The ALDH(br) CD34(neg) cells were not efficiently supported by any of the assays used. These studies suggested that in particular the expression of ALDH delineated distinct CD34+ stem cell and progenitor compartments. The differential expression of ALDH may provide a means to explore normal and malignant processes associated with myeloid and lymphoid development.

Neurogenic differentiation of murine and human adipose-derived stromal cells.

The identification of cells capable of neuronal differentiation has great potential for cellular therapies. We examined whether murine and human adipose-derived adult stem (ADAS) cells can be induced to undergo neuronal differentiation. We isolated ADAS cells from the adipose tissue of adult BalbC mice or from human liposuction tissue and induced neuronal differentiation with valproic acid, butylated hydroxyanisole, insulin, and hydrocortisone. As early as 1-3 h after neuronal induction, the phenotype of ADAS cells changed towards neuronal morphology. Following neuronal induction, muADAS cells displayed immunocytochemical staining for GFAP, nestin and NeuN and huADAS cells displayed staining for intermediate filament M, nestin, and NeuN. Following neuronal induction of murine and human ADAS cells, Western blot analysis confirmed GFAP, nestin, and NeuN protein expression. Pretreatment with EGF and basic FGF augmented the neuronal differentiation of huADAS cells. The neuronal differentiation of stromal cells from adipose tissue has broad biological and clinical implications.