Effectiveness of micron-sized superparamagnetic iron oxide particles as markers for detection of migration of bone marrow-derived mesenchymal stromal cells in a stroke model.

PURPOSE: To evaluate the feasibility of using micron-sized superparamagnetic iron oxide particles (MPIOs) as an effective labeling agent for monitoring bone marrow-derived mesenchymal stromal cell (BMSC) migration in the brain using magnetic resonance imaging (MRI) in a rat model of stroke and whether the accumulation of MPIO-labeled BMSCs can be differentiated from the accumulation of free MPIO particles or hemoglobin breakdown at a site of neuronal damage. MATERIALS AND METHODS: In this study BMSCs were labeled with iron oxide and their pattern of migration following intravenous injection in a rat stroke model was monitored using a clinical MRI system followed by standard histopathology. The migration pattern was compared between intravenous injection of BMSCs alone, BMSCs labeled with MPIOs, and MPIO particles alone. RESULTS: The results demonstrated that while MRI was highly sensitive in the detection of iron oxide particle-containing cells in areas of neuronal ischemia, the true origin of cells containing iron oxide particles remains ambiguous. Therefore, detection of iron particles may not be a suitable strategy for the detection of BMSCs in the brain in a stroke model. CONCLUSION: This study suggests that the use of MPIOs as labeling agents are insufficient to conclusively determine the localization of iron within cells in regions of neuronal ischemia and hemorrhage.

Effect of gestational ethanol exposure on parvalbumin and calretinin expressing hippocampal neurons in a chick model of fetal alcohol syndrome.

Fetal alcohol syndrome (FAS), a condition occurring in some children of mothers who have consumed alcohol during pregnancy, is characterized by physical deformities and learning and memory deficits. The chick hippocampus, whose functions are controlled by interneurons expressing calcium-binding proteins parvalbumin (PV) and calretinin (CR), is involved in learning and memory mechanisms. Effects on growth and development and hippocampal morphology were studied in chick embryos exposed to 5% and 10% ethanol volume/volume (vol/vol) for 2 or 8 days of gestation. There was a significant dose-dependent reduction (P<.05) in body weight and mean number per section of PV and CR expressing hippocampal neurons in ethanol-exposed chicks, without alterations in neuronal nuclear size or hippocampal volume, compared appropriate controls. Moreover, when chicks exposed to 5% ethanol for 2 and 8 days of gestation were compared, no significant differences were found in body parameters or neuronal counts. Similarly, exposure to 10% ethanol did not induce any significant changes in chicks exposed for 2 or 8 gestational days. Thus, these results suggest that gestational ethanol exposure induces a reduction in the mean number per section of PV and CR expressing hippocampal neurons, and could be a possible mechanism responsible for learning and memory disorders in FAS.

Laser capture microscope: an innovative tool for single cell dissection.

Increasing strides have recently been made in the understanding of the biologic basis of health and disease, largely because of the current emphasis on investigations directed at a cellular level. This has necessitated the development and use of convenient, accurate and reliable research equipment. While it is not necessitated the need for every researcher or clinician to be fully knowledgeable of all the intricacies of the recent developments in the field of research equipment, basic awareness of new research tools is the critical to the understanding and analysis of results obtained from current studies. The laser capture microscope is one of the most recent research equipment that permits easy dissection and examination of single cells from tissues. This has enabled researchers to carry out specific studies on the behaviour of different cell populations in a tissue sample. This article aims to explain the basic principles of the usage of laser capture microscope for single cell dissection.

Effect of gestational ethanol exposure on long-term memory formation in newborn chicks.

Fetal alcohol syndrome (FAS), a condition occurring in some children of mothers who have consumed alcohol during pregnancy, is characterized by craniofacial malformations, and physical and mental retardation. It is significant that even children with history of gestational ethanol exposure but relatively unaffected overall IQ performance, often exhibit learning difficulties and behavioral problems, suggestive of impaired memory formation. Hence, the specific aim of this study was to examine memory formation in chicks exposed to ethanol during early gestation toward the understanding of neurobehavioral disturbances in FAS. Chicks were exposed to alcohol on gestational days 1-3 by injection of ethanol into the airspace of freshly fertilized eggs. The effects of prenatal ethanol on physical growth and development, and memory formation were studied. The one-trial passive avoidance learning paradigm in 1-day-old chicks was used to study memory formation in these chicks. It was observed that chick embryos exposed to 10% ethanol on gestational days 1-3 had significant reduction in all body parameters when compared with appropriate controls. Further, ethanol-exposed chick embryos had significantly impaired (P<.05) long-term memory (LTM) formation after training, though short-term or intermediate-term memory formation was unimpaired. Thus, the findings of the current study demonstrate the detrimental effects of ethanol exposure during early pregnancy on developing chick embryos in general and on memory formation in particular. Hence, it is suggested that impairment in LTM could be a fundamental mechanism for learning disorders and neurobehavioral abnormalities observed in FAS.

The Role of Caregivers in the Management of Alzheimer's disease: Examples from Asian Countries.

The demographic profile of the Asian population is rapidly changing, with a fast increasing ageing population, owing to an increase in longevity and a decreasing birth rate. Moreover, due to improved medical facilities and the increased aged population, Alzheimer's disease (AD) is fast emerging as a major health problem in many Asian countries. As curative treatment for AD is still elusive, care giving is an important component of the management of AD. While Western countries have recognised this issue, besides highly industrialized Japan, the Asian initiative has been relatively slow. This article aims to address issues involved in caregiving in AD in some Asian countries.

Genes arrayed out for you: the amazing world of microarrays.

Microarrays, a recent development, have provided a revolutionary platform for the study of gene expression, regulation and function. Thus, it has tremendous potential in the study of biological processes in health and disease. Notable examples include the identification of regulatory genes in the cell cycle mechanism, and disease causing genes in malignancies and certain neurodegenerative disorders. Therefore, microarray-based studies have provided the necessary impetus for biomedical experiments, particularly following the sequencing of the human genome. However, it must be emphasized that microarrays are not the sole purview of biologists, but represent the amalgamation of the efforts of biomedical scientists, technologists and statisticians. This is particularly considering the challenges in the manufacture of microarrays and supporting equipment, and the meaningful analyses of the tremendous volume of data generated by these experiments. In this article, the principles and technological concerns regarding microarrays and microarray-based experiments, the steps involved in obtaining and the rationale of analyses of data derived from these experiments is reviewed. Further, some aspects of microarray-based experimentation, such as experimental design, and data handling and interpretation are discussed. However, as with all novel methods there is still scope for improvement. The relative merits and demerits of microarrays and analysis of microarray based data are reviewed, along with current issues of concern and future possibilities. Thus, the overall aim of this article is to highlight some of the past and potential future uses of microarray-based experiments and present a broad overview of this rapidly growing technology.

Effect of a single dose of ethanol on developing skeletal muscle of chick embryos.

Fetal alcohol syndrome is a condition occurring in some children of mothers who have consumed alcohol during pregnancy. Many of these affected children show retarded physical growth in the postnatal period despite adequate nutrition. On the basis of findings from studies with animals, it has been proposed that this is due to allometric retardation of growth of skeletal muscle, although the exact reasons for this are not known. The aim of the current study was to examine the structural changes in skeletal muscle in fetal alcohol syndrome in an attempt to understand the mechanisms of growth retardation in fetal alcohol syndrome. Chick embryos were exposed to single doses of 5%, 10%, and 15% ethanol, and the effects on the general growth and development, as well as on the skeletal muscle, of these chicks were studied. There was a significant retardation in crown rump length, head circumference, and body weight in ethanol-exposed chicks when these parameters were compared with findings for appropriate control groups. This retardation was associated with significant and proportionate reductions in the weights of skeletal muscles. Microscopic examination of skeletal muscle showed areas of neutrophil infiltration and necrosis, suggestive of muscle damage, in chicks exposed to 10% and 15% ethanol. Thus, findings of the current study demonstrate the direct toxic effects of a single dose of ethanol on developing embryos in general and skeletal muscle in particular. The pathologic changes seen in skeletal muscle could account for the failure in postnatal growth in fetal alcohol syndrome.