A comparison of four leukapheresis methods to harvest an optimal dose of CD34+ cells: A single center experience.

BACKGROUND: Chemokine receptor CXCR4 antagonist plerixafor (Px) as well as high volume (HV) leukapheresis have been shown to reduce hematopoietic stem progenitor cell (HSPC) mobilization failure rates. However, no direct comparisons of such methods currently exists. METHODS AND MATERIALS: We compared the HSPC collection yield based on basal peripheral blood CD34+ cell numbers in patients diagnosed with multiple myeloma or non-Hodgkin's lymphoma undergoing autologous stem cell transplantation in a retrospective chart review. The leukapheresis methods used included HV versus regular volume (RV) with or without Px. There were 116 patients in the study group while the historical control group had 34 patients. RESULTS AND CONCLUSIONS: Control group underwent RV leukapheresis without Px. Addition of Px or HV in the study group failed to display significant improvement in CD34+ cell collection yield; however, when basal CD34+ cell numbers were taken into account, both Px + RV and HV without Px increased CD34+ cell collection yield. The collection failure rates of HV without Px group were comparable to Px + RV when the basal CD34+ cell numbers were over 20/µl. Of interest, multivariate linear regression analysis did not detect any significant difference between HV versus Px + RV or other leukapheresis methods in CD34 yields or collection failure rates from a single collection after controlling for other factors (sex, age, or underlying disease). In multivariate analysis, pre apheresis CD34+ cell number was significantly and positively associated with the CD34+ cell yields from a single apheresis. In our studies, the majority of patients can be rescued without Px by HV alone as a potential cost saving approach. In summary, trend in our studies reflects that both Px and HV are capable of reducing the mobilization failure rates except the poorest mobilizers, which will need to be validated in larger studies.

Race/ethnicity and underlying disease influences hematopoietic stem/progenitor cell mobilization response: A single center experience.

BACKGROUND: Whether race/ethnicity plays a role in hematopoietic stem/progenitor cells (HSPC) mobilization in autologous donors has not been studied. We hypothesize that donor characteristic including race/ethnicity, age, sex, body mass index, and diagnostic groups influences HSPC mobilization. Diagnostic groups include healthy allogeneic donors, autologous multiple myeloma (MM) and non-MM donors. STUDY DESIGN AND METHODS: Here, we conducted a single-center retrospective study in 64 autologous patients and 48 allogeneic donors. Autologous donors were patients diagnosed with MM or non-MM. All donors were grouped as African American (AA), White (W), or "Other"(O). RESULTS: Multivariate analysis demonstrated diagnostic group differences for CD34+ cell yields between race/ethnicity. Specifically, non-MM patients had the lowest CD34+ cell yields in AA and O, but not in W. For pre-apheresis peripheral blood (PB) CD34+ cell numbers, race/ethnicity had a significant effect both in bivariate and multivariate analyses. Non-MM patients had the lowest, and AA patients had the highest PB CD34+ cells. The results support the view that past therapies used in MM are likely more conducive of recovery of HSPC. CONCLUSIONS: Our study shows that race/ethnicity and diagnostic group differences influenced CD34+ cell mobilization response across donor types. Interestingly, autologous MM donors with the aid of plerixafor displayed comparable CD34 yields to allogeneic donors. Even though both MM and non-MM donors received plerixafor, non-MM donors had significantly lower CD34 yields among AA and O donors but not in W donors. Larger studies would be required to validate the role of diagnostic groups and race/ethnicity interactions.

Assessment of glioma response to radiotherapy using 3D pulsed-continuous arterial spin labeling and 3D segmented volume.

BACKGROUND: Gliomas are the most common primary brain tumors in adults, in some cases, radiotherapy may be the preferred treatment option especially for elderly people who cannot endure surgery. Therefore, it is necessary to evaluate the effects of radiotherapy on glioma. Arterial spin labeling (ASL) is an MR imaging technique that allows for a quantitative determination of cerebral blood flow (CBF) noninvasively. Tumor volume is still an important determinant for evaluating treatment response. The purpose of this study was to investigate the relationship between the tumor perfusion parameters and tumor volume and assess the effects of radiotherapy on glioma using pulsed-continuous arterial spin labeling (pcASL) technique. METHODS: 35 patients with gliomas, histologically classified as low-grade group (n=16) and high-grade group (n=19), treated with radiotherapy only or before using other therapies were included in this study. MR examinations, including T1 weighted image and pcASL, were performed before and 4, 8, 12, 16 weeks after radiotherapy. Regional CBF of normal tissue, mean tumor blood flow (TBFmean), maximum tumor blood flow (TBFmax), and tumor volume were evaluated at each time point. Both the percentage change in CBF (CBF ratio), TBFmean (TBFmean ratio), TBFmax (TBFmax ratio) and the percentage change in tumor volume (volume ratio) were calculated using values obtained before and after radiotherapy. The correlation between the volume ratio and CBF ratio, TBFmean ratio, TBFmax ratio was assessed using linear regression analysis and Pearson's correlation. RESULTS: The TBFmean and TBFmax of high-grade gliomas were significantly higher than that of low-grade group. In high-grade group, a strong correlation was demonstrated between the tumor volume and the TBFmax before radiotherapy (R2=0.35, rs=0.59, p<0.05). There was also a significant correlation between the TBFmax before radiotherapy and the tumor volume ratio before and 8 weeks after radiotherapy (R2=0.56, rs=-0.74, p<0.05). CONCLUSION: The TBFmax measured using pcASL could assess tumoral grade and also could become a potential tool for evaluating the therapeutic effects of radiation.

Comparison of Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging and Arterial Spin Labeling MR Imaging in Gliomas.

Gliomas grading is important for treatment plan; we aimed to investigate the application of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in gliomas grading, by comparing with the three-dimensional pseudocontinuous arterial spin labeling (3D pCASL). 24 patients (13 high grade gliomas and 11 low grade gliomas) underwent IVIM DWI and 3D pCASL imaging before operation; maps of fast diffusion coefficient (D (∗)), slow diffusion coefficient (D), fractional perfusion-related volume (f), and apparent diffusion coefficient (ADC) as well as cerebral blood flow (CBF) were calculated and then coregistered to generate the corresponding parameter values. We found CBF and D (∗) were higher in the high grade gliomas, whereas ADC, D, and f were lower (all P < 0.05). In differentiating the high from low grade gliomas, the maximum areas under the curves (AUC) of D (∗), CBF, and ADC were 0.857, 0.85, and 0.902, respectively. CBF was negatively correlated with f in tumor (r = -0.619, P = 0.001). ADC was positively correlated with D in both tumor and white matter (r = 0.887, P = 0.000 and r = 0.824, P = 0.000, resp.). There was no correlation between CBF and D (∗) in both tumor and white matter (P > 0.05). IVIM DWI showed more efficiency than 3D pCASL but less validity than conventional DWI in differentiating the high from low grade gliomas.

VEGF is crucial for the hepatic vascular development required for lipoprotein uptake.

Hepatic lipid catabolism begins with the transport of lipoprotein remnants from the sinusoidal vasculature into hepatocytes by endocytosis via microvilli. To test the hypothesis that fenestrated sinusoidal endothelial cells (SECs) are crucial for this process, we selectively disrupted SECs by downregulating vascular endothelial growth factor (VEGF) signaling, using hepatocyte-specific, tetracycline-regulatable expression of a VEGF receptor that can sequester VEGF but cannot relay its signal. Newborn mutant livers appeared grossly normal, but displayed a dark-red color that was distinguishable from normal physiological lipid-rich pink livers. Mutant sinusoidal networks were reduced and their SECs lacked fenestrae. Hepatocellular lipid levels were profoundly reduced, as determined by Oil Red O staining and transmission electron microscopy, and fewer hepatocytic microvilli were evident, indicating impaired lipoprotein endocytosis. Levels of apolipoprotein (APO) E bound to mutant sinusoidal networks were significantly reduced, and fluorescently-labeled murine remnant lipoproteins injected into the blood stream failed to accumulate in the space of Disse and diffuse into hepatocytes, providing evidence that reduced hepatocellular lipid levels in mutant livers are due to impaired lipoprotein uptake. Temporal downregulation of VEGF signaling revealed that it is crucial at all developmental stages of hepatic vascular morphogenesis, and repression of the dominant-negative effect can rescue the phenotype. These findings provide the first genetic evidence that VEGF dynamically regulates SEC fenestration during liver organogenesis, a process that is required for lipoprotein uptake by the liver.

Variation in primary sequence and tandem repeat copy number among i-antigens of Ichthyophthirius multifiliis.

The immobilization antigens (i-antigens) of Ichthyophthirius multifiliis are potential vaccine candidates for the prevention of 'white spot' disease in freshwater fish. These antigens vary with respect to antigenicity and molecular mass, and at least five i-antigen serotypes have been identified among parasite isolates thus far. In previous studies, the gene and corresponding cDNA encoding a approximately 48 kDa i-antigen from parasite isolate G1 (serotype A), had been cloned and sequenced. We now report on the isolation of two new genes, designated IAG52A[G5] and IAG52B[G5], encoding approximately 52/55 kDa i-antigens from a parasite isolate representing a different serotype, namely, D. Based on their deduced sequences, the approximately 52/55 kDa gene products have the same structural features as the 48 kDa protein including hydrophobic N- and C-termini, periodic cysteine residues with the potential for metal binding, and tandemly repetitive amino acid sequence domains that span their length. Nevertheless, the products of these genes vary in their tandem repeat copy number, and share only approximately 50% homology overall. When expressed in heterologous systems, the products of the newly described genes react strongly with monospecific polyclonal antisera against the i-antigens of serotype D and are clearly i-antigens. It would nevertheless appear that mRNA transcripts from the two genes are present at widely different levels within parasites themselves. Analysis at the protein level using 2-D SDS-PAGE would further suggest that multiple i-antigens are expressed within the same serotype at any given time.