Browsing by Author "Hokin, Bevan"
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Item Effect of Maternal Iron Status on the Number of CD34+ Stem Cells Harvested from Umbilical Cord Blood(2014-07-14) Grant, Ross; Hokin, Bevan; Pope, BelindaBackground
Hematopoietic progenitor cells (HPCs) from umbilical cord blood (UCB) are an alternative source of stem cells. However an adequate number of HPCs must be harvested from each UCB sample to make therapeutic applications possible. This study investigated the impact of selected maternal indices (in particular iron status) on the number of CD34+ cells collected in the UCB.
Study Design and Methods
Blood samples were collected from 91 matched mother and umbilical cord pairs and analyzed for full blood count, iron status, and C-reactive protein. Viable CD34 enumeration was performed on the cord blood samples.
Results
Low CD34+ cell counts were associated with higher maternal serum ferritin (SF), older mothers, lower UCB white blood cell count (WCC), lower UCB nucleated red blood cells (NRBCs), and lower birthweight. Maternal SF correlated with maternal variables of iron status and RBC indices, newborn weight, placental weight, and NRBCs/100 WCC.
Conclusion
This study indicates that lower numbers of CD34+ cells are more likely to occur when collected from mothers with higher SF. This finding suggests that maternal SF and associated iron status play a significant, but as yet undefined, role in the generation of CD34+ cells in UCB.
Item Effect of Umbilical Cord Blood Prefreeze Variables on Postthaw Viability(2015-03-11) Grant, Ross; Hokin, Bevan; Pope, BelindaBackground
Assessment of the overall postthaw (PT) viability of an umbilical cord blood (UCB) unit is an important criterion for determining the quality of the unit for transplantation. Overall PT viability is a measure of cellular damage that can occur to the UCB during collection, storage, processing, freezing, and thawing.
Study Design and Methods
This study investigated factors measured before freezing of the UCB that could affect overall PT viability of the stem cell unit from 257 collected cord blood samples. The analysis included hematologic variables, cord blood collection characteristics, and stem cell separation and preservation factors.
Results
Each of the variables, postprocess (PP) neutrophils (%), PP hematocrit, overall PP viability (%), freeze rate (°C/min), and time from collection to freezing (hr) were shown to contribute to overall PT viability. Each UCB sample was given a calculated “viability prediction” (VP) score based on the influence or impact of each of these variables. This score was compared to the measured PT viability. Variables with a low VP score had correspondingly low PT viability, indicating more overall damage to the cells. The results showed that the higher the VP score, the higher the PT viability.
Conclusion
These findings provide a framework for identifying those units that are most likely to have a high overall PT viability and hence an increased likelihood of successful engraftment of the CB-sourced stem cells. The VP score could aid in the selection of a donor cord blood unit for transplantation.
Item Novel Relationships between B12, Folate and Markers of Inflammation, Oxidative Stress and NAD(H) Levels, Systemically and in the CNS of a Healthy Human Cohort(2015-09-14) Grant, Ross; Croft, Kevin D.; Mori, Trevor A.; Hokin, Bevan; Bilgin, Ayse; Guest, JadeObjective: To evaluate the relationship between folate, cobalamin (Cbl), and homocysteine (Hcy), and markers of inflammation and oxidative stress within the periphery and central nervous system (CNS) of a healthy human cohort.
Methods: Thirty-five matched cerebrospinal fluid (CSF) and plasma samples were collected from consenting participants who required a spinal tap for the administration of anaesthetic. Plasma concentrations of Hcy and both plasma and CSF levels of folate, Cbl, nicotinamide adenine dinucleotide (NAD(H)) and markers of inflammation (interleukin-6, IL-6), and oxidative stress (F2-isoprostanes, 8-hydroxy-2′-deoxyguanosine (8-OHdG), and total antioxidant capacity (TAC)) were quantified.
Results: In the peripheral circulation, positive associations were observed between plasma folate and Cbl, and plasma TAC (P ≤ 0.01; P ≤ 0.01) and plasma NAD(H) (P ≤ 0.05; P ≤ 0.05) levels, respectively. Plasma folate was inversely associated with plasma Hcy concentrations (P ≤ 0.05); however, no statistically significant relationships were observed between plasma Hcy and plasma markers of inflammation, oxidative stress, or [NAD(H)].
Within the CNS plasma Hcy correlated positively with CSF IL-6 (P ≤ 0.01) and negatively with CSF NAD(H) (P ≤ 0.05) concentrations. An inverse association was observed between CSF folate and CSF levels of IL-6 (P ≤ 0.05). Unexpectedly, a positive association between CSF Cbl and CSF 8-OHdG levels was also found (P ≤ 0.01).
Discussion: These results indicate that folate and Cbl concentrations may influence the levels of oxidative damage, inflammation, and NAD(H), both systemically and within the CNS.
Item The Relative Impact of a Vegetable-rich Diet on Key Markers of Health in a Cohort of Australian Adolescents(2008-03-01) Ashton, John; Hokin, Bevan; Pearce, Robyn; Guy, Trish; Zeuschner, Carol; Bilgin, Ayse; Grant, RossChildhood obesity is a widespread health problem in Australia. Overweight in childhood can lead to adult overweight and the development of risk factors for cardiovascular disease (CVD). Effective strategies for reducing childhood obesity are urgently required. A vegetarian diet has been shown to be an effective prophylactic to many lifestyle diseases in the adult population and may therefore be beneficial in children. However the metabolic demands of adolescents are different to adults and the impact of a vegetarian diet on CVD markers in this demographic is not certain. We compared key physiological and biochemical markers of health against responses to a modified, Schools Physical Activity and Nutrition Survey (SPANS) using one-way and two-way Analysis of Variance. 215 adolescents (14-15yrs) from 5 Adventist secondary schools in the Sydney and Hunter regions of New South Wales, Australia, participated in this study. Adolescents consuming predominantly vegetarian foods showed significantly better scores on markers of cardiovascular health, including, body mass index (BMI), waist circumference, Cholesterol/High density lipoprotein ratio and low density lipoprotein. Adolescents consuming nuts more than once per week, also showed lower scores for BMI and serum glucose irrespective of their vegetarian status. Markers of general health including haemoglobin and average height were not different between groups; however a lower serum level of vitamin B12 was apparent in the vegetarian cohort. Surprisingly, exercise on its own was not statistically associated with any of the risk factors tested suggesting that diet may be the most significant factor in promoting health in this age group.