Differential marker expression by cultures rich in mesenchymal stem cells

Background: Mesenchymal stem cells have properties that make them amenable to therapeutic use. However, the acceptance of mesenchymal stem cells in clinical practice requires standardized techniques for their specific isolation. To date, there are no conclusive marker (s) for the exclusive isolation of mesenchymal stem cells. Our aim was to identify markers differentially expressed between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. We compared and contrasted the phenotype of tissue cultures in which mesenchymal stem cells are rich and rare. By initially assessing mesenchymal stem cell differentiation, we established that bone marrow and breast adipose cultures are rich in mesenchymal stem cells while, in our hands, foreskin fibroblast and olfactory tissue cultures contain rare mesenchymal stem cells. In particular, olfactory tissue cells represent non-stem cell mesenchymal cells. Subsequently, the phenotype of the tissue cultures were thoroughly assessed using immuno-fluorescence, flow-cytometry, proteomics, antibody arrays and qPCR. Results: Our analysis revealed that all tissue cultures, regardless of differentiation potential, demonstrated remarkably similar phenotypes. Importantly, it was also observed that common mesenchymal stem cell markers, and fibroblast-associated markers, do not discriminate between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. Examination and comparison of the phenotypes of mesenchymal stem cell and non-stem cell mesenchymal cell cultures revealed three differentially expressed markers – CD24, CD108 and CD40. Conclusion: We indicate the importance of establishing differential marker expression between mesenchymal stem cells and non-stem cell mesenchymal cells in order to determine stem cell specific markers

Degree of concordance between peripheral blood leukemic blast count and mid induction bone marrow in childhood acute lymphoblastic leukemia

While different Pediatric ALL study groups have used varying definitions of early response (BM vs. PB, prophase vs. day 7 vs. day 14), all agree that it provides critical prognostic information. Bone Marrow aspiration and biopsy (BMA/B) is an invasive procedure requiring sedation or anesthesia, and an early/mid induction specimen may be difficult to interpret even by experienced hematopathologists. In this study we attempted to determine if there was a concordance between peripheral blood blast (PBB) clearance and the findings of the day 14 BMA/B, and whether day 7 PBB count could reliably replace a mid induction BMA/B. Clinical data for newly diagnosed pediatric (\u3c14 years) ALL patients between January 1999 and December 2001 were retrieved from our prospective database. Day 14 BMA/B slides were reviewed independently by two hematopathologist. For the total 165 patients, median age was 4 years, 53.9% were boys. Complete information was available for 151 of these patients and further analysis is based on this number. 124 (82.1%) were treated with 4 agents while the remainder received a 3-drug induction. 23 (18.5%) had positive PBB on D7, and 21 (13.9%) had \u3e5% blasts in the D14 BMA/B. The D7 PBB count could positively and negatively predict the D14 BMA/B 71.9% and 89.4% of the times, respectively. In conclusion, when the D14 BMA/B is used as a measure of early response, an absence of D7 PBB can reliably predict a negative BM, however persistence of PBB does not necessarily predict a sub-optimal BM response to early therapy. Therefore, patients without PBB on D7 may not require BMA/B on D14, therefore avoiding an invasive procedure for this group of patients

Methylation of BRCA1 and MGMT genes in white blood cells are transmitted from mothers to daughters

Abstract Background Constitutive methylation of tumor suppressor genes are associated with increased cancer risk. However, to date, the question of epimutational transmission of these genes remains unresolved. Here, we studied the potential transmission of BRCA1 and MGMT promoter methylations in mother-newborn pairs. Methods A total of 1014 female subjects (cancer-free women, n = 268; delivering women, n = 295; newborn females, n = 302; breast cancer patients, n = 67; ovarian cancer patients, n = 82) were screened for methylation status in white blood cells (WBC) using methylation-specific PCR and bisulfite pyrosequencing assays. In addition, BRCA1 gene expression levels were analyzed by quantitative real-time PCR. Results We found similar methylation frequencies in newborn and adults for both BRCA1 (9.9 and 9.3%) and MGMT (12.3 and 13.1%). Of the 290 mother-newborn pairs analyzed for promoter methylation, 20 mothers were found to be positive for BRCA1 and 29 for MGMT. Four mother-newborn pairs were positive for methylated BRCA1 (20%) and nine pairs were positive for methylated MGMT (31%). Intriguingly, the delivering women had 26% lower BRCA1 and MGMT methylation frequencies than those of the cancer-free female subjects. BRCA1 was downregulated in both cancer-free woman carriers and breast cancer patients but not in newborn carriers. There was a statistically significant association between the MGMT promoter methylation and late-onset breast cancers. Conclusions Our study demonstrates that BRCA1and MGMT epimutations are present from the early life of the carriers. We show the transmission of BRCA1 and MGMT epimutations from mother to daughter. Our data also point at the possible demethylation of BRCA1and MGMT during pregnancy

Single nucleotide polymorphisms in CXCR1 gene and its association with hepatitis B infected patients in Saudi Arabia

Background/Aim. This study aims to investigate whether the SNPs of CXCR1 gene, could predict the likelihood of viral persistence and/or disease progression.Material and methods. We investigated the association of two different SNPs (rs2234671, and rs142978743) in 598 normal healthy controls and 662 HBV patients from a Saudi ethnic population. The HBV patients were categorized into inactive carriers (n = 428), active carriers (n = 162), cirrhosis (n = 54) and Cirrhosis-HCC (n = 18) sub-groups. Genetic variants in CXCR1 were determined by polymerase chain reaction (PCR)-based DNA direct sequencing.Results. The frequency of the risk allele ‘C’ for the SNP, rs2234671 was found to be insignificant when the patient group was compared to the uninfected control group, however, a significant distribution of the allele ‘C’ of rs2234671 was observed among active HBV carriers + cirrhosis + cirrhosis - HCC vs. inactive HBV carriers with an OR = 1.631 (95% C.I. 1.016-2.616) and p = 0.032. However, no significant association was observed for rs142978743 when the distribution of risk allele was analyzed among the different patient groups (i.e. inactive carriers, active carriers, cirrhosis and HCC). Furthermore, the most common haplotype, Haplo-1 (AG), was found to have an insignificant frequency distribution between HBV cases and controls, while the same haplotype was found to be significantly distributed when active carriers + cirrhosis + cirrhosis - HCC patients were compared to inactive HBV carriers with a frequency of 0.938 and p = 0.0315. Haplo-2 (AC) was also found to be significantly associated with a frequency of 0.058 and p = 0.0163.Conclusion. The CXCR1 polymorphism, rs2234671 was found to be associated with chronic HBV infection and may play a role in disease activity

Understanding the role of therapeutic plasma exchange in COVID-19: preliminary guidance and practices

Background and objectives: Cytokine release syndrome in COVID-19 is due to a pathological inflammatory response of raised cytokines. Removal of these cytokines by therapeutic plasma exchange (TPE) prior to end-organ damage may improve clinical outcomes. This manuscript is intended to serve as a preliminary guidance document for application of TPE in patients with severe COVID-19. Material and methods: The available literature pertaining to the role of TPE for treatment of COVID-19 patients was reviewed to guide optimal management. It included indication, contraindication, optimal timing of initiation and termination of TPE, vascular access and anticoagulants, numbers and mode of procedures, outcome measures and adverse events. Results: Out of a total of 78 articles, only 65 were directly related to the topic. From these 65, only 32 were acceptable as primary source, while 33 were used as supporting references. TPE in critically ill COVID-19 patients may be classified under ASFA category III grade 2B. The early initiation of TPE for 1–1·5 patient’s plasma volume with fresh frozen plasma, or 4–5% albumin or COVID-19 convalescent plasma as replacement fluids before multiorgan failure, has better chances of recovery. The number of procedures can vary from three to nine depending on patient response. Conclusion: TPE in COVID-19 patients may help by removing toxic cytokines, viral particles and/or by correcting coagulopathy or restoring endothelial membrane. Severity score (SOFA & APACHE II) and cytokine levels (IL-6, C-reactive protein) can be used to execute TPE therapy and to monitor response in COVID-19 patients