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Background/Objectives: Despite novel biological agents, steroid-dependent or -refractory graft-versus-host disease (GvHD) remains a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT). Extracorporeal photopheresis (ECP) is an alternative, non-immunosuppressive treatment for patients with acute (aGvHD) or chronic (cGvHD) GvHD. The aim of this study was to investigate the safety and efficacy of ECP in the treatment of acute and chronic GvHD; Methods: We prospectively studied 112 patients with cGvHD who received one or more previous lines of treatment and 28 patients with steroid-dependent or refractory grade II-IV aGvHD post-alloHSCT. Results: In terms of severe aGvHD, most of the patients (19/28) responded to ECP treatment, while the five-year overall survival (OS) was 34%. After adjustment for several confounder factors, the reduction in immunosuppression ( p = 0.026) and number of ECP sessions ( p < 0.001) were associated with improved OS. Regarding chronic GvHD, only 19 patients failed to respond to ECP treatment; though significantly lower rates of response were presented in patients with visceral involvement ( p = 0.037) and earlier post-transplant GVHD diagnosis ( p = 0.001). Over a follow-up period of 45.2 [interquartile range (IQR): 5.6-345.1] months, the 5-year cumulative incidence (CI) of cGvHD-related mortality was 21.2% and was significantly reduced in patients with ECP response ( p < 0.001), while the 5-year OS was 65.3%. Conclusions: Our results confirm the safety and efficacy of ECP in patients with GvHD and provide sufficient data for further investigation and the best combination drugs needed such that GvHD will not be the major barrier of allo-HCT in the near future.

Background: Allogeneic hematopoietic stem cell transplantation (allo-HCT) represents a curative treatment for various blood-related disorders, including hematological malignancies and genetic disorders. The success of this procedure hinges on the efficacy of the conditioning regimen and the graft's ability to engraft and function properly. Microparticles (MPs), small vesicles produced from stimulated, apoptotic, or activated cells, are involved in both physiological and pathological processes. However, the impact of MPs on allo-HCT remains poorly understood., Objectives: This study aimed to investigate the presence of MPs from different cell types in grafts and patient plasma after allo-HCT, as well as their association with various parameters. We measured MPs from CD34+, CD56+, CD3+, CD19+, and CD33+ cells in grafts and patient plasma from day 0 to day 60 after transplantation., Methods: 224 blood samples were collected from 19 consecutive allo -HCT recipients at 0, +4, +14,+30 and + 60 day as well as from their grafts. MPs isolated from the plasma and quantified by flow cytometry analysis., Results: MP levels varied over time. Notably, CD34+ MP levels were linked to both early and late engraftment of neutrophils and platelets. Furthermore, grafts with high CD34+ and CD56+ MP levels in patient plasma on days 0 and + 4 were associated with late engraftment, whereas high CD33+ MP levels in both graft and patient plasma on day +4 were associated with early engraftment. Conditioning regimen affected CD19+ MP levels at day +14, and the number of CD34+, CD56+, and CD19+ MPs 30 days after transplantation was correlated with acute graft-versus-host disease., Conclusion: These findings suggest that MPs derived from hematopoietic cells may play a significant role in the clinical course of patients following allo-HCT., Competing Interests: Conflict of interest statement There are no conflicts of interest to report., (Copyright © 2024. Published by Elsevier B.V.)

A graft source for allogeneic hematopoietic stem cell transplantation is umbilical cord blood, which contains umbilical cord blood mononuclear cells (MNCs and mesenchymal stem cells, both an excellent source of extracellular microparticles (MPs). MPs act as cell communication mediators, which are implicated in reactive oxygen species formation or detoxification depending on their origin. Oxidative stress plays a crucial role in both the development of cancer and its treatment by triggering apoptotic mechanisms, in which CD34+ cells are implicated. The aim of this work is to investigate the oxidative stress status and the apoptosis of HL-60 and mononuclear cells isolated from umbilical cord blood (UCB) following a 24- and 48-hour exposure to CD34 + microparticles (CD34 + MPs). The activity of superoxide dismutase, glutathione reductase, and glutathione S-transferase, as well as lipid peroxidation in the cells, were employed as oxidative stress markers. A 24- and 48-hour exposure of leukemic and mononuclear cells to CD34 + -MPs resulted in a statistically significant increase in the antioxidant activity and lipid peroxidation in both cells types. Moreover, CD34 + MPs affect the expression of BCL2 and FAS and related proteins and downregulate the hematopoietic differentiation program in both HL-60 and mononuclear cells. Our results indicate that MPs through activation of antioxidant enzymes in both homozygous and nonhomozygous cells might serve as a means for graft optimization and enhancement., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Hydroxyurea (HU) is a commonly used first-line treatment in patients with polycythemia vera (PV). However, approximately 15%-24% of PV patients report intolerance and resistance to HU., Methods: This phase IV, European, real-world, observational study assessed the efficacy and safety of ruxolitinib in PV patients who were resistant and/or intolerant to HU, with a 24-month follow-up. The primary objective was to describe the profile and disease burden of PV patients., Results: In the 350 enrolled patients, 70% were >60 years old. Most patients (59.4%) had received ≥1 phlebotomy in the 12 months prior to the first dose of ruxolitinib. Overall, 68.2% of patients achieved hematocrit control with 92.3% patients having hematocrit <45% and 35.4% achieved hematologic remission at month 24. 85.1% of patients had no phlebotomies during the study. Treatment-related adverse events were reported in 54.3% of patients and the most common event was anemia (22.6%). Of the 10 reported deaths, two were suspected to be study drug-related., Conclusion: This study demonstrates that ruxolitinib treatment in PV maintains durable hematocrit control with a decrease in the number of phlebotomies in the majority of patients and was generally well tolerated., (© 2023 The Authors. European Journal of Haematology published by John Wiley & Sons Ltd.)

The umbilical cord blood (UCB) donated in public UCB banks is a source of hematopoietic stem cells (HSC) alternative to bone marrow for allogeneic HSC transplantation (HSCT). However, the high rejection rate of the donated units due to the strict acceptance criteria and the wide application of the haploidentical HSCT have resulted in significant limitation of the use of UCB and difficulties in the economic sustainability of the public UCB banks. There is an ongoing effort within the UCB community to optimize the use of UCB in the field of HSCT and a parallel interest in exploring the use of UCB for applications beyond HSCT i.e., in the fields of cell therapy, regenerative medicine and specialized transfusion medicine. In this report, we describe the mode of operation of the three public UCB banks in Greece as an example of an orchestrated effort to develop a viable UCB banking system by (a) prioritizing the enrichment of the national inventory by high-quality UCB units from populations with rare human leukocyte antigens (HLA), and (b) deploying novel sustainable applications of UCB beyond HSCT, through national and international collaborations. The Greek paradigm of the public UCB network may become an example for countries, particularly with high HLA heterogeneity, with public UCB banks facing sustainability difficulties and adds value to the international efforts aiming to sustainably expand the public UCB banking system.

Commercially available anti-CD19 chimeric antigen receptor T cells (CARΤ cells) have offered long-term survival to a constantly expanding patient population. Given that novel toxicities including cytokine release syndrome (CRS) and neurotoxicity (ICANS) have been observed, we aimed to document the safety and toxicity of this treatment in a real-world study. We enrolled 31 adult patients referred to our center for CAR T therapy. Tisagenlecleucel was infused in 12 patients, axicabtagene ciloleucel in 14, and brexucabtagene autoleucel in 5. Cytokine release syndrome was noted in 26 patients while neurotoxicity was observed in 7. Tocilizumab was administered for CRS in 18 patients, along with short-term, low-dose steroid administration in one patient who developed grade III CRS and, subsequently, grade I ICANS. High-dose steroids, along with anakinra and siltuximab, were administered in only two MCL patients. With a median follow-up time of 13.4 months, nine patients were then in CR. The progression-free (PFS) and overall survival (OS) rates were 41.2% and 88.1% at one year, respectively. MCL diagnosis, which coincides with the administration of brexucabtagene autoleucel, was the only factor to be independently associated with poor OS ( p < 0.001); meanwhile, increased LDH independently predicted PFS ( p = 0.027).In addition, CRP at day 14 was associated with a poor OS ( p = 0.001). Therefore, our real-world experience confirmed that commercial CAR T therapy can be administered with minimal toxicity.

(1) Background: Autologous, allogeneic hematopoietic cell transplantation (HCT) and other cellular therapies, including CAR T cell and gene therapy, constitute a cornerstone in the management of various benign and malignant hematological disorders. Invasive fungal infections (IFD) remain a significant cause of morbidity and mortality in HCT recipients. Therefore, we investigated the prevalence and risk factors of IFD following HCT and other cellular therapies in an era of novel antifungal prophylaxis. (2) Methods: In this study, we retrospectively enrolled adult HCT recipients who were treated at our JACIE-accredited center according to standard operating procedures over the last decade (2013-2022). (3) Results: 950 patients who received cellular therapies were studied. None of the 19 CAR T cell and neither of the two gene therapy recipients developed IFD whereas 3/456 autologous HCT recipients who suffered from primary refractory/relapsed lymphomas presented with probable IFD. Overall, 11 patients who received allogeneic HCT experienced probable IFD, possible IFD was found in 31/473, and IFD was proven in 10/473. A second IFD episode was present in three patients. Four-year OS was significantly lower in proven compared to probable IFD ( p = 0.041) and was independently associated with HCT-CI ( p = 0.040) and chronic GVHD ( p = 0.045). (4) Conclusions: In this real-world cohort, the prevalence of proven and probable IFD in an era of novel antifungal prophylaxis was found to be relatively low. However, IFDs were associated with poor outcomes for patients who received allogeneic HCT.

Thrombosis is the most common and a life-threatening complication in patients with Paroxysmal Nocturnal Hemoglobinuria. One-third of patients with PNH experience at least one thromboembolic event during the course of the disease, with thrombosis being the most common cause of death in these patients. The mechanism of thrombosis in PNH is complex and continues to be of great research interest. Since the introduction of C5 complement inhibitors in the treatment of PNH, the incidence of thromboembolic events has decreased substantially. We retrospectively analyzed data concerning the thrombotic episodes of 41 patients with PNH from 14 different national hematology centers in Greece. Sixteen patients (39%) experienced at least one episode of thrombosis, including, seven (43.8%) at diagnosis, seven (43.8%) during the course of the disease and two (12.5%) patients prior to PNH diagnosis. Nearly half of these individuals (n=7, 43.8%) had multiple episodes of thrombosis during the course of their disease. The most common sites of thrombosis were intra-abdominal veins. Three out of 26 patients developed thrombosis while on eculizumab. In none of the 16 patients, the thrombotic event was fatal. Our findings, despite the small number of patients, confirmed that thrombosis continues to be a significant complication of PNH affecting more than one third of the patients., Competing Interests: MA advisory board Alexion. PZ advisory board Alexion and Sobi. EM advisory board Alexion, honoraria Sobi. TM advisory board Sobi. SK advisory board Alexion. GV advisory board Sobi, honoraria Alexion. IK honoraria Alexion and Sobi. CL advisory board Sobi and Alexion. IB advisory board Alexion and Sobi. MP advisory board Alexion, honoraria AstraZeneca. MP advisory board Alexion, honoraria AstraZeneca. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer CP declared a shared parent affiliation with the authors MP and HAP to the handling editor at the time of review., (Copyright © 2023 Chatzileontiadou, Hatjiharissi, Angelopoulou, Asimakopoulos, Loutsidi, Chatzikonstantinou, Zikos, Bouchla, Bezirgiannidou, Kouvata, Frouzaki, Chaloudis, Sotiropoulos, Douka, Sirigou, Mandala, Psyllaki, Papadaki, Marinakis, Viniou, Kokkori, Kontopidou, Skepetari, Vassilopoulos, Kotsianidis, Pappa, Lalayanni, Baltadakis, Delimpassi, Pagoni and Papaioannou.)

We have attempted to explore further the involvement of complement components in the host COVID-19 (Coronavirus disease-19) immune responses by targeted genotyping of COVID-19 adult patients and analysis for missense coding Single Nucleotide Polymorphisms (coding SNPs) of genes encoding Alternative pathway (AP) components. We have identified a small group of common coding SNPs in Survivors and Deceased individuals, present in either relatively similar frequencies (CFH and CFI SNPs) or with stark differences in their relative abundance (C3 and CFB SNPs). In addition, we have identified several sporadic, potentially protective, coding SNPs of C3, CFB, CFD, CFH, CFHR1 and CFI in Survivors. No coding SNPs were detected for CD46 and CD55. Our demographic analysis indicated that the C3 rs1047286 or rs2230199 coding SNPs were present in 60 % of all the Deceased patients (n = 25) (the rs2230199 in 67 % of all Deceased Males) and in 31 % of all the Survivors (n = 105, p = 0.012) (the rs2230199 in 25 % of all Survivor Males). When we analysed these two major study groups using the presence of the C3 rs1047286 or rs2230199 SNPs as potential biomarkers, we noticed the complete absence of the protective CFB rs12614 and rs641153 coding SNPs from Deceased Males compared to Females (p = 0.0023). We propose that in these individuals, C3 carrying the R102G and CFB lacking the R32W or the R32Q amino acid substitutions, may contribute to enhanced association dynamics of the C3bBb AP pre-convertase complex assembly, thus enabling the exploitation of the activation of the Complement Alternative pathway (AP) by SARS-CoV-2., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

There is an unmet need of models for early prediction of morbidity and mortality of Coronavirus disease-19 (COVID-19). We aimed to a) identify complement-related genetic variants associated with the clinical outcomes of ICU hospitalization and death, b) develop an artificial neural network (ANN) predicting these outcomes and c) validate whether complement-related variants are associated with an impaired complement phenotype. We prospectively recruited consecutive adult patients of Caucasian origin, hospitalized due to COVID-19. Through targeted next-generation sequencing, we identified variants in complement factor H/CFH, CFB, CFH-related, CFD, CD55, C3, C5, CFI, CD46, thrombomodulin/THBD, and A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS13). Among 381 variants in 133 patients, we identified 5 critical variants associated with severe COVID-19: rs2547438 (C3), rs2250656 (C3), rs1042580 (THBD), rs800292 (CFH) and rs414628 (CFHR1). Using age, gender and presence or absence of each variant, we developed an ANN predicting morbidity and mortality in 89.47% of the examined population. Furthermore, THBD and C3a levels were significantly increased in severe COVID-19 patients and those harbouring relevant variants. Thus, we reveal for the first time an ANN accurately predicting ICU hospitalization and death in COVID-19 patients, based on genetic variants in complement genes, age and gender. Importantly, we confirm that genetic dysregulation is associated with impaired complement phenotype., (© 2022 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Adenoviral infections in immunocompromised individuals may be life-threatening conditions. The aim of this review is to document all the reported cases of adenoviral infection is patients having undergone bone marrow transplantation (BMT). A comprehensive literature search of the databases Pubmed, Science Direct, and Google Scholar was conducted to identify all the case reports of adenoviral infections in BMT patients. A total of 30 articles with 44 patients were included. The most common underlying condition was acute lymphocytic leukemia (23%) followed by acute myeloid leukemia (18%). The most common site of infection was disseminated (50%), followed by liver infection (8%) and hemorrhagic cystitis (8%). Cidofovir was administered in 40.9% of the cases, and death was reported in 34.4% of them. Ribavirin was administered as monotherapy in 15.9% of patients, with a mortality rate of 57.1%. We found that the antiviral drug option had no statistically significant effect on the mortality rate (p=0.242). Also, the absence of graft-versus-host disease (GVHD) was not associated with an improved outcome (p=0.523). There was, however, a statistically significant difference in the outcome based on the site of infection (p=0.005), with a higher rate of mortality in the disseminated and gastrointestinal cases. To the best of our knowledge, this is the first review documenting all the cases of adenoviral infections in BMT patients. Future randomized studies are needed to validate the results of the present study., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Keramari et al.)

Advances in immunotherapy with T cells armed with chimeric antigen receptors (CAR-Ts), opened up new horizons for the treatment of B-cell lymphoid malignancies. However, the lack of appropriate targetable antigens on the malignant myeloid cell deprives patients with refractory acute myeloid leukaemia of effective CAR-T therapies. Although non-engineered T cells targeting multiple leukaemia-associated antigens [i.e. leukaemia-specific T cells (Leuk-STs)] represent an alternative approach, the prerequisite challenge to obtain high numbers of dendritic cells (DCs) for large-scale Leuk-ST generation, limits their clinical implementation. We explored the feasibility of generating bivalent-Leuk-STs directed against Wilms tumour 1 (WT1) and preferentially expressed antigen in melanoma (PRAME) from umbilical cord blood units (UCBUs) disqualified for allogeneic haematopoietic stem cell transplantation. By repurposing non-transplantable UCBUs and optimising culture conditions, we consistently produced at clinical scale, both cluster of differentiation (CD)34 + cell-derived myeloid DCs and subsequently polyclonal bivalent-Leuk-STs. Those bivalent-Leuk-STs contained CD8 + and CD4 + T cell subsets predominantly of effector memory phenotype and presented high specificity and cytotoxicity against both WT1 and PRAME. In the present study, we provide a paradigm of circular economy by repurposing unusable UCBUs and a platform for future banking of Leuk-STs, as a 'third-party', 'off-the-shelf' T-cell product for the treatment of acute leukaemias., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)

Background: Although the ability of β-D-glucan and monophosphoryl lipid A (MPLA) to modulate immune responses has been studied in human primary cells, their effect on sterile inflammation models such as necrotizing pancreatitis has never been investigated., Materials and Methods: 85 male New Zealand rabbits were assigned into following groups: A: control, B: pretreatment with β-D-glucan 3 d before pancreatitis, C: pretreatment with MPLA 3 d before pancreatitis, D: pretreatment with β-D-glucan and laminarin 3 d before pancreatitis, E: treatment with β-D-glucan 1 d after pancreatitis, and F: MPLA 1 d after pancreatitis. Pancreatitis was induced by sodium taurocholate injection into the pancreatic duct and parenchyma. Survival was recorded for 21 d. On days 1, 3, and 7, blood was collected for amylase measurement. Peripheral blood mononuclear cells were isolated and stimulated for tumor necrosis factor alpha and interleukin 10 production. Pancreatic necrosis and tissue bacterial load were assessed., Results: 21-d survival was prolonged after pretreatment or treatment with β-D-glucan; this benefit was lost with laminarin administration. At sacrifice, pancreatic inflammatory alterations were more prominent in the control group. Bacterial load was lower after pretreatment or treatment with β-D-glucan and MPLA. Tumor necrosis factor alpha production from stimulated peripheral blood mononuclear cells was significantly decreased, whereas interleukin 10 production remained unaltered after pretreatment or treatment with β-D- glucan., Conclusions: β-D-glucan reduces mortality of experimental pancreatitis in vivo. This is mediated through attenuation of cytokine production and prevention of bacterial translocation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Recent studies suggest excessive complement activation in severe coronavirus disease-19 (COVID-19). The latter shares common characteristics with complement-mediated thrombotic microangiopathy (TMA). We hypothesized that genetic susceptibility would be evident in patients with severe COVID-19 (similar to TMA) and associated with disease severity. We analyzed genetic and clinical data from 97 patients hospitalized for COVID-19. Through targeted next-generation-sequencing we found an ADAMTS13 variant in 49 patients, along with two risk factor variants (C3, 21 patients; CFH,34 patients). 31 (32%) patients had a combination of these, which was independently associated with ICU hospitalization (p = 0.022). Analysis of almost infinite variant combinations showed that patients with rs1042580 in thrombomodulin and without rs800292 in complement factor H did not require ICU hospitalization. We also observed gender differences in ADAMTS13 and complement-related variants. In light of encouraging results by complement inhibitors, our study highlights a patient population that might benefit from early initiation of specific treatment., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Agricultural biomass can be best described as the organic matter residues from farming that remain within the fields after harvesting, along with tree trimmings. From the overall Greek Energy Balance, only a small fraction consists of biomass and this has been the main driving force behind this study. Due to the numerous ongoing agricultural activities, western Greece was selected as an ideal area for a case study. As a second step, the aim was to investigate the feasibility of the current anaerobic digestion plants to utilize the total biomass as feedstock. An additional scope to provide certifiable proof of the essential rural biomass assets available. Information on the potential of agricultural biomass is provided, with a focus on the performance specifications and the social advantages, but also the soil added substances and the produced biofuels. Subsequently, two options for waste management were discussed to illustrate the possibility of generating energy. The anaerobic digestion plants available in western Greece are illustrated in detail and the yearly rate of the main agrarian biomass is evaluated to be 715,080 tons. Arable crops, mechanical plants and tree trimming are recorded as the noteworthy sources. It is estimated that the proposed anaerobic digestion system will handle the entire amount of biomass and deliver max per year electricity 775 GWh and thermal energy 1.119 GWh.

The new alleles A*02:943 and B*51:104:02 were detected in Greek cord blood units., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-Kp) emerge as a major healthcare concern worldwide. Despite the significance of infections before and after allogeneic hematopoietic cell transplantation (alloHCT), the burden of KP infections has not been extensively evaluated. Methods: We studied the incidence, risk factors, and outcomes of consecutive alloHCT recipients with Kp isolates before and after alloHCT. Results: Among 424 patients who underwent alloHCT in 2008-2018, we studied two groups: those with Kp isolates before (group 1, 52 patients) and those with Kp isolates after alloHCT (group 2, 66 patients). prE-transplant infections were associated with post-transplant infections ( p = 0.010), despite secondary prophylaxis. KPC-Kp was isolated in 29% of group 1, and 80% of group 2. Both groups were characterized by a significant burden of moderate-severe acute graft- vs.-host disease (GVHD) [cumulative incidence (CI) of 44.5 and 61.9%, respectively] and severe chronic (CI of 56.7 and 61.9%). Kp infections and GVHD were independent predictive factors of treatment-related mortality (TRM) in both groups. Conclusions: Our study highlights the significant impact of Kp infections on TRM, with GVHD consisting an important underlying factor. As prophylactic measures did not improve rates of post-transplant infections, innovative interventions need to be further investigated to address this major healthcare concern., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Gavriilaki, Sakellari, Chatzikonstantinou, Mallouri, Batsis, Katsifa, Papadimitriou, Panteliadou, Baldoumi, Demosthenous, Bousiou, Constantinou, Sotiropoulos and Anagnostopoulos.)

Umbilical cord blood CD34+ (UCB-CD34+) stem cells are clinically used in hematopoietic cell transplantation. However, there are limitations in the use of umbilical cord blood transplants because of the small number of cells and delayed engraftment. To gain a better understanding of functional components of UCB, we have detected and characterized CD34+ microparticles (CD34+MPs) from cord blood units. We collected cord blood units and assessed the numbers of CD34+MPs before and after red blood cell and plasma depletion by SEPAX processing using flow cytometry analysis. In parallel we identified MPs by electron microscopy. CD34+MPs and cells were isolated by MACs sorting. MicroRNAs (miR-106, miR-221, miR-517, miR-519, and miR-221) exhibited a characteristic microRNA profile that was further validated in isolated CD34+MPs. We found that in cord blood, there are CD34+MPs that carry microRNAs., (Copyright © 2019 ISEH -- Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.)

Limited and conflicting data exist on outcomes of patients with extramedullary relapses (EMRs) after allogeneic hematopoietic cell transplantation (allo-HCT) for acute leukemias. We retrospectively reviewed charts of consecutive allo-HCT recipients who underwent transplantation in our center with the indication of acute leukemia (July 1990 to July 2018). Incidences of isolated EMR (iEMR) and bone marrow relapse (BMR) were calculated using cumulative incidence (CI) analysis, with each and treatment-related mortality considered a competing risk. We studied 554 allo-HCT recipients for 1.8 years (range, .04 to 27.75). Ten-year CI of 10.5% for iEMR was associated only with advanced disease phase at transplantation, whereas 10-year CI of 34.8% for BMR was independently associated with pretransplant disease phase, lines of treatment, and fungal infections. Most iEMR and BMR patients (75% and 81%, respectively) received systemic treatment combined with local radiation for iEMR (26%) and donor lymphocyte infusions (16% and 28%, respectively) when feasible. Extensive chronic graft-versus-host disease (GVHD) was recorded in 47% of iEMR and 48% of BMR patients. Outcomes were poor both in iEMR (10-year overall survival [OS], 18.3%) and BMR (10-year OS, 19.1%). Independent predictors of OS were disease phase, type of donor, acute and chronic GVHD, fungal infections, iEMR, and BMR. In a large population with long-term follow-up, incidence of iEMR was relatively high, developed at the late post-transplant period, and was associated only with disease phase at transplantation. Furthermore, iEMR and BMR conferred similarly poor outcomes despite systemic treatment or extensive chronic GVHD., (Copyright © 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background: The reporting of adverse events (AE) remains an important part of quality improvement in thoracic surgery. The best methodology for AE reporting in surgery is unclear. An AE reporting system using an electronic discharge summary with embedded data collection fields, specifying surgical procedure and complications, was developed. The data are automatically transferred daily to a web-based reporting system., Methods: We determined the accuracy and sustainability of this electronic real time data collection system (ERD) by comparing the completeness of record capture on procedures and complications with coded discharge data (administrative data), and with the standard of chart audit at two intervals. All surgical procedures performed for 2 consecutive months at initiation (Ti) and 1 year later (T1yr) were audited by an objective trained abstractor. A second abstractor audited 10% of the charts., Results: The ERD captured 71/72 (99%) of charts at Ti and 56/65 (86%) at T1yr. Comparing the presence/absence of complications between ERD and chart audit demonstrated at Ti a high sensitivity and specificity, positive predictive value (PPV) of 95.5%, negative predictive value (NPV) of 93.9% with a kappa of 0.872 (95% CI 0.750 to 0.994), and at T1yr a sensitivity, specificity, PPV and NPV of 100% with a kappa of 1.0 (95% CI 1.0). Comparing the presence/absence of complications between administrative data and chart audit at Ti demonstrated a low sensitivity, high specificity and a kappa of 0.471 (95% CI 0.256 to 0.686), and at T1yr a low sensitivity, high specificity of 85% and a kappa of 0.479 (95% CI 0.245 to 0.714)., Conclusions: We found that the ERD can provide accurate real time AE reporting in thoracic surgery, has advantages over previous reporting methodologies and is an alternative system for surgical clinical teams developing AE reporting systems., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

The role of total body irradiation (TBI) in allogeneic hematopoietic stem cell transplantation (HCT) for adult acute lymphoblastic leukemia (ALL) remains controversial. Therefore, we investigated long-term treatment outcomes of transplanted ALL patients aiming to identify prognostic factors and the impact of conditioning. We enrolled consecutive ALL patients transplanted from 1990 to 2016, following TBI- or busulfan (Bu)-based conditioning regimen. We studied 151 ALL patients transplanted in first complete remission (CR) (60), other CR (33), or relapsed/refractory disease (58) from sibling (87), and HLA-matched (42) or mismatched (17) unrelated and alternative donors (5). High-dose fractionated TBI-based conditioning was administered in 84. No differences were observed in baseline characteristics, except for disease stage at transplant, donor type, and graft source. With a follow-up of 19.0 (0.5-170.5) in TBI and 14.5 (1.2-319.1) months in non-TBI patients, there was no difference in acute (grades II-IV) or chronic GVHD, thrombotic microangiopathy, and bacterial or fungal infections. Only viral infections were significantly increased in the non-TBI group. There was no significant difference in the cumulative incidence (CI) of treatment-related or relapse mortality and disease-free or overall survival (OS). In the multivariate analysis, unfavorable pre-transplant predictors of OS were age (p = 0.024), advanced disease stage (p = 0.007), and female-to-male donor (p = 0.006). Interestingly, TBI patients younger than 40 years had significantly higher OS (55.1%, p = 0.023) and DFS (48.6%, p = 0.020). In conclusion, high-dose TBI is feasible in younger patients providing better survival. The choice between TBI- or Bu-conditioning regimens remains challenging.

The proximity of consonant clusters in child speech is measured in the literature by the proportion of adult-like produced clusters to targeted clusters. With this measure, all clusters that are produced adult-like score 100%, while all others score 0%. Consonant clusters in child speech go through three main developmental stages: omission, reduction, two-member production (as targeted or substituted). Several authors claim that two-member clusters produced as two members should be considered acquired whether realised as targeted or not. In view of all these, a measure is needed that quantitatively differentiates all possible realisations of two-member clusters: omission, reduction, vowel epenthesis, two-member production, distinguishing substituted consonants from adult-like ones. Such a measure is proposed in the present article. To demonstrate its validity, the measure is applied to cluster productions of typically and atypically developing monolingual and bilingual children cross-linguistically. Moreover, it is applied to a bilingual Greek-English child's consonant clusters at age 2;7, when all cluster realisations are present. The aim is for the measure to be used in establishing norms for each stage in cluster development which will, in turn, guide assessment and intervention in phonologically delayed/disordered children.

Objectives: The aim of this study was to present up to date information concerning the diagnosis and treatment of primary aldosteronism (PA). PA is the most common cause of endocrine hypertension. It has been reported up to 24% of selective referred hypertensive patients., Methods: We did a search in Pub-Med and Google Scholar using the terms: PA, hyperaldosteronism, idiopathic adrenal hyperplasia, diagnosis of PA, mineralocorticoid receptor antagonists, adrenalectomy, and surgery. We also did cross-referencing search with the above terms. We had divided our study into five sections: Introduction, Diagnosis, Genetics, Treatment, and Conclusions. We present our results in a question and answer fashion in order to make reading more interesting., Results: PA should be searched in all high-risk populations. The gold standard for diagnosis PA is the plasma aldosterone/plasma renin ratio (ARR). If this test is positive, then we proceed with one of the four confirmatory tests. If positive, then we proceed with a localizing technique like adrenal vein sampling (AVS) and CT scan. If the lesion is unilateral, after proper preoperative preparation, we proceed, in adrenalectomy. If the lesion is bilateral or the patient refuses or is not fit for surgery, we treat them with mineralocorticoid receptor antagonists, usually spironolactone., Conclusions: Primary aldosteronism is the most common and a treatable case of secondary hypertension. Only patients with unilateral adrenal diseases are eligible for surgery, while patients with bilateral and non-surgically correctable PA are usually treated by mineralocorticoid receptor antagonist (MRA). Thus, the distinction between unilateral and bilateral aldosterone hypersecretion is crucial.

Objectives: To present a step by step approach for the diagnosis of adrenal incidentaloma (AI)., Method: An extensive review of the literature was conducted, searching the Pub-Med and Google Scholar using the Mesh terms; Adrenal; Incidentaloma; Adrenal tumours; Radiology; Diagnosis. We also did a cross-referencing search of the literature. Comments on the new European guidelines are presented., Results: The majority of the tumours are non-functioning benign adenomas. The most important radiological characteristic of an adrenal incidentaloma is the radiation attenuation coefficient. Wash out percentage and the imaging characteristics of the tumour may help in diagnosis., Conclusion: Density less than 10 HU is in most cases characteristic of a lipid rich benign adenoma. More than 10 HU or/and history of malignancy raise the possibility for cancer. 1 mg dexamethasone test and plasma metanephrines should be done in all patients. If there is history of hypokalemia and/or resistant hypertension we test the plasma aldosterone to plasma renin ratio (ARR). Newer studies have shown that tumours even nonfunctioning and less than 4 cm may increase the metabolic risks so we may consider surgery at an earlier stage.

Introduction: Anti-thymocyte globulin (ATG)-based immunosuppressive therapy is often used in allogeneic hematopoietic cell transplantation to reduce incidence and severity of graft-versus-host disease (GVHD)., Patients and Methods: In our observational study, ATG (rabbit, Thymoglobulin; Sanofi, 5 mg/kg) was administered as a standardized part of the conditioning in 97 patients with a median age of 34 years (range, 14-58 years), allotransplanted for hematologic malignancies from matched (8/8; n = 52) and allele or antigen mismatched (7/8; n = 43 and 6/8; n = 2) unrelated donors., Results: Five-year overall survival (OS) was 46.9%, disease-free survival was 46.5%, and treatment-related mortality was 20.6%, with a median follow-up of 29 months (range, 1-145 months). Acute GVHD (grade ≥ II) cumulative incidence was 26.9% in matched versus 50.5% in mismatched patients (P = .060), whereas extensive chronic GVHD was 45.6% versus 50%, respectively (P = .310). Five-year OS was 62.2% for the matched patients and 27.9% for the mismatched patients (P = .003) owing to a higher treatment-related mortality rate in mismatched patients (P = .032). In multivariate analysis including age, gender, time until transplantation, disease phase, mismatched donor, ABO mismatch, number of CD34+ infused, acute and chronic GVHD, the significant unfavorable factors for OS were HLA mismatch and advanced disease phase., Conclusion: A relatively low-dose ATG is effective in acute GVHD prophylaxis, leading to promising survival rates in matched transplants. Further comparative studies with adjusted ATG dose depending on Human leukocyte antigen disparity or alternative donors are warranted., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: We conducted an extensive review of the literature and tried to cite the most recent recommendations concerning the pheochromocytoma (PHEO)., Methods: Pub Med and Google Scholar databases were searched systematically for studies concerning pheochromocytomas (intra-adrenal paragangliomas) from 1980 until 2016. Bibliographies were searched to find additional articles., Results: More than four times elevation of plasma fractionated metanephrines or elevated 24-h urinary fractionated metanephrines are keys to diagnosing pheochromocytoma. If the results are equivocal then we perform the clonidine test. If we have not done it already, we preferably do a CT scan and/or an MRI scan. The patient needs pre-treatment with α1-blockers at least 10-14 days before operation. Alternatives or sometimes adjuncts are Calcium Channels Blockers and/or β-Blockers. Several familial syndromes are associated with PHEO and genetic testing should be considered., Conclusions: The biggest problem for pheochromocytoma is to suspect it in the first place. Elevated metanephrines establish the diagnosis. With the proper preoperative preparation the risks during operation and the postoperative period are minimal. If there is a risk of the hereditable mutation, it is strongly suggested that all the patients with pheochromocytoma need clinical genetic testing.

Treosulfan has been incorporated in conditioning regimens for sustained remission without substantial toxicity and treatment-related mortality (TRM). We aimed to analyze the safety and efficacy of a fludarabine 150 mg/m 2 and treosulfan 42 g/m 2 (FluTreo) conditioning regimen in medically infirm patients. Outcomes were compared with those of a similar historical group treated with fludarabine 150 mg/m 2 to 180 mg/m 2 , busulfan 6.4 mg/kg, and antithymocyte globulin (ATG) 5 mg/kg to 7.5 mg/kg (FluBuATG). Thirty-one consecutive patients with acute myeloid leukemia (AML; n = 21), myelodysplastic syndrome (MDS; n = 6), or treatment-related AML (n = 4) received FluTreo conditioning. The historical group consisted of 26 consecutive patients treated with FluBuATG. In the FluTreo group, engraftment was prompt in all patients and 74% achieved >99% donor chimerism by day +30. No grades III or IV organ toxicities were noted. One-year cumulative incidences (CI) of acute and chronic graft-versus-host disease (GVHD) were 19.4% and 58.4%. The groups were similar for age, disease risk, lines of treatment, hematopoietic cell transplantation-specific comorbidity index, and acute or chronic GVHD incidence, except that there were more matched unrelated donor recipients in the FluTreo group (P < .001). With 20 (range, 2 to 36) months follow-up for FluTreo and 14 (range, 2 to 136) for FluBuATG, the 1-year cumulative overall survival (OS) probability was 76% versus 57%, respectively (P = .026); 1-year disease-free survival (DFS) was 79% versus 38% (P < .001). In multivariate analysis, the only significantly favorable factor for OS and DFS was FluTreo (P = .010 and P = .012). The CI of relapse mortality was markedly decreased in FluTreo versus FluBuATG (7.4% versus 42.3%, P < .001). In conclusion, the treosulfan-based regimen resulted in favorable OS and DFS with acceptable toxicity and low relapse rates compared with busulfan-based conditioning., (Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Liposomal amphotericin B, voriconazole, and caspofungin are currently used for systemic and severe fungal infections. Patients with malignant diseases are treated with granulocyte-colony stimulating factor (G-CSF) for the recovery of granulocytes after chemotherapy or hematopoietic cell (HC) transplantation. Since they have a high incidence of fungal infections, they inevitably receive antifungal drugs for treatment and prophylaxis. Despite their proven less toxicity for various cell types comparatively with amphotericin B and the decrease in the number of leukocytes that has been reported as a possible complication in clinical studies, the effect of liposomal amphotericin B, voriconazole, and caspofungin on HCs has not been clarified. The present study aimed to examine the in vitro and in vivo effect of these three modern antifungals on HCs. Colony-forming unit (CFU) assays of murine bone marrow cells were performed in methylcellulose medium with or without cytokines and in the presence or absence of various concentrations of liposomal amphotericin B, voriconazole, and caspofungin. In the in vivo experiments, the absolute number of granulocytes was determined during leukocyte recovery in sublethally irradiated mice receiving each antifungal agent separately, with or without G-CSF. In vitro, all three antifungal drugs were nontoxic and, interestingly, they significantly increased the number of CFU-granulocyte-macrophage colonies in the presence of cytokines, at all concentrations tested. This was contrary to the concentration-dependent toxicity and the significant decrease caused by conventional amphotericin B. In vivo, the number of granulocytes was significantly higher with caspofungin plus G-CSF treatment, higher and to a lesser extent higher, but not statistically significantly, with voriconazole plus G-CSF and liposomal amphotericin B plus G-CSF treatments, respectively, as compared with G-CSF alone. These data indicate a potential synergistic effect of these antifungals with the cytokines, in vitro and in vivo, with subsequent positive effect on hematopoiesis., (© 2015 by the Society for Experimental Biology and Medicine.)

Optimal conditioning remains a challenge in lymphomas. We designed a regimen consisting of Busulfex, etoposide and melphalan (BuEM). We retrospectively analyzed the outcome of patients conditioned with carmustine, etoposide, cytarabine and melphalan (BEAM) or BuEM in matched-pair analysis on a planned 2:1 ratio. Eighty-seven patients treated with BEAM who fulfilled the matching criteria were randomly selected. Two-year progression-free survival/overall survival (PFS/OS) were 63.2%/76.7% for BEAM vs. 65.6%/79.8% for BuEM after 64.7 and 42.7 months, respectively. Furthermore, marginally better PFS and OS were noted in Hodgkin lymphoma (HL) after BuEM. In multivariate analysis, PFS was superior in HL, chemosensitive disease and complete remission post-transplant. BEAM correlated with faster engraftment, reduced infections, less mucositis and liver toxicity, and BuEM with less need for blood cell and platelet transfusions and granulocyte colony-stimulating factor administration. In conclusion, BuEM was well tolerated and equally highly efficacious as BEAM for non-Hodgkin lymphoma and offered marginally significantly improved PFS and OS in HL with acceptable toxicity and zero mortality.

Necrotizing fasciitis (NF) is a severe, rare, potentially lethal soft tissue infection that develops in the scrotum and perineum, the abdominal wall, or the extremities. The infection progresses rapidly, and septic shock may ensue; hence, the mortality rate is high (median mortality 32.2%). Prognosis becomes poorer in the presence of co-morbidities, such as diabetes mellitus, immunosuppression, chronic alcohol disease, chronic renal failure, and liver cirrhosis. NF is classified into four types, depending on microbiological findings. Most cases are polymicrobial, classed as type I. The clinical status of the patient varies from erythema, swelling, and tenderness in the early stage to skin ischemia with blisters and bullae in the advanced stage of infection. In its fulminant form, the patient is critically ill with signs and symptoms of severe septic shock and multiple organ dysfunction. The clinical condition is the most important clue for diagnosis. However, in equivocal cases, the diagnosis and severity of the infection can be secured with laboratory-based scoring systems, such as the laboratory risk indicator for necrotizing fasciitis score or Fournier's gangrene severity index score, especially in regard to Fournier's gangrene. Computed tomography or ultrasonography can be helpful, but definitive diagnosis is attained by exploratory surgery at the infected sites. Management of the infection begins with broad-spectrum antibiotics, but early and aggressive drainage and meticulous debridement constitute the mainstay of treatment. Postoperative management of the surgical wound is also important for the patient's survival, along with proper nutrition. The vacuum-assisted closure system has proved to be helpful in wound management, with its combined benefits of continuous cleansing of the wound and the formation of granulation tissue.

Invasive candidiasis is a life-threatening infection in patients with haematological malignancies. The objective of our study was to determine the incidence, microbiological characteristics and clinical outcome of candidaemia among hospitalized adult patients with haematological malignancies. This is a population-based, prospective, multicentre study of patients ≥ 18 years admitted to haematology and/or haematopoietic stem cell transplantation units of nine tertiary care Greek hospitals from January 2009 through to February 2012. Within this cohort, we conducted a nested case-control study to determine the risk factors for candidaemia. Stepwise logistic regression was used to identify independent predictors of 28-day mortality. Candidaemia was detected in 40 of 27,864 patients with haematological malignancies vs. 967 of 1,158,018 non-haematology patients for an incidence of 1.4 cases/1000 admissions vs. 0.83/1000 respectively (p <0.001). Candidaemia was caused predominantly (35/40, 87.5%) by non-Candida albicans species, particularly Candida parapsilosis (20/40, 50%). In vitro resistance to at least one antifungal agent was observed in 27% of Candida isolates. Twenty-one patients (53%) developed breakthrough candidaemia while receiving antifungal agents. Central venous catheters, hypogammaglobulinaemia and a high APACHE II score were independent risk factors for the development of candidaemia. Crude mortality at day 28 was greater in those with candidaemia than in control cases (18/40 (45%) vs. 9/80 (11%); p <0.0001). In conclusion, despite antifungal prophylaxis, candidaemia is a relatively frequent infection associated with high mortality caused by non-C. albicans spp., especially C. parapsilosis. Central venous catheters and hypogammaglobulinaemia are independent risk factors for candidaemia that provide potential targets for improving the outcome., (© 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.)

Background: Burkholderia cepacia complex (Bcc) is a group of common environmental bacteria that preferentially colonize and infect patients with cystic fibrosis but are also emerging as nosocomial pathogens, possibly due to their resistance to disinfectants and antimicrobials., Methods: We investigated a 3-month outbreak of Bcc bacteremia among hospitalized hematology patients. Environmental investigation and infection control measures were implemented. A retrospective, cross-sectional study was conducted to identify risk factors., Results: Bcc was repeatedly isolated from the blood of 9 patients without central venous catheter who did not easily respond to targeted antibiotic treatment and 3 died of the infection. A point source was not identified and horizontal spread was suspected. Strict infection control measures terminated the outbreak. Interestingly, diagnosis of acute myeloid leukemia but not neutropenia or prior chemotherapy was a risk factor for infection acquisition. Neutropenia was positively correlated with infection duration., Conclusions: Bcc is not only a serious threat among immunocompromized hematology patients, but is also transmissible in clinical settings. Acute myeloid leukemia appears to confer additional risk for infection acquisition., (Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.)

Background: We postulated that the abundance of various metabolites in blood would facilitate the diagnosis of pancreatic and biliary lesions, which could potentially prevent unnecessary surgery., Methods: Serum samples from patients with benign hepatobiliary disease (n = 43) and from patients with pancreatic cancer (n = 56) were examined by ¹H NMR spectroscopy to quantify 58 unique metabolites. Data were analyzed by "targeted profiling" followed by supervised pattern recognition and orthogonal partial least-squares discriminant analysis (O-PLS-DA) of the most significant metabolites, which enables comparison of the whole sample spectrum between groups., Results: The metabolomic profile of patients with pancreatic cancer was significantly different from that of patients with benign disease (AUROC, area under the ROC curve, = 0.8372). Overt diabetes mellitus (DM) was identified as a possible confounding factor in the pancreatic cancer group. Thus, diabetics were excluded from further analysis. In this more homogeneous pancreatic cancer group, compared with benign cases, serum concentrations of glutamate and glucose were most elevated on multivariate analysis. In benign cases, creatine and glutamine were most abundant. To examine the usefulness of this test, a comparison was made to age- and gender-matched controls with benign lesions that mimic cancer, controlling also for presence of jaundice and diabetes (n = 14 per group). The metabolic profile in patients with pancreatic cancer remained distinguishable from patients with benign pancreatic lesions (AUROC = 0.8308)., Conclusions: The serum metabolomic profile may be useful for distinguishing benign from malignant pancreatic lesions., Impact: Further studies will be required to study the effects of jaundice and diabetes. A more comprehensive metabolomic profile will be evaluated using mass spectrometry., (©2010 AACR.)

Objective: Waldenström's macroglobulinemia (WM) is a low-grade lymphoplasmacytoid lymphoma characterized by production of monoclonal immunoglobulin M (IgM). The present study was undertaken with the aim of developing a novel nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse model of WM., Materials and Methods: Pairs of bone particles derived from adult humans were successfully implanted intramuscularly in NOD/SCID mice. Each mouse was implanted with a bone fragment taken from a neoplastic disease-free individual in the one hind limb and with a different biopsy taken from a WM patient in the other., Results: All mice implanted with the bone marrow core biopsies had increased levels of serum IgM 1 month following the implantation onward. Histopathologic and immunohistochemical analysis showed that in approximately half of the mice WM cells metastasized from the WM bone implant to the distantly implanted non-WM bone. Serum IgM value records of all mice correlated with histopathological observations and immunohistochemical analysis for neoplastic cell density and metastatic growth., Conclusion: Results obtained in the present study suggest that IgM-producing WM cells not only retained viability in the bone marrow of the WM bone biopsy, but also metastasized to the normal bone marrow of the distant bone implant. The mouse model reported here improves on existing models of WM by recapitulating the adult human bone marrow microenvironment of abnormal WM neoplastic cells.

Purpose: To present a treatment plan for localized mucosa-associated lymphoid tissue lymphoma of the orbit in order to preserve vital structures and function from the side effects of radiotherapy., Materials and Methods: Study of 2 clinical cases by means of clinical and radiologic examination, with 2 and 3 years follow-up, respectively., Results: Immediate remission of the disease after 6 cycles of chemotherapy, with no signs of recurrence after 2 and 3 years. Clinical examination of the oculomotor mechanism and visual activity gave excellent results., Conclusion: Although radiotherapy is preferable for localized lymphoproliferative lesions, chemotherapy should also be considered as an effective treatment that preserves the integrity and function of the ocular adnexa.

Emitted pollutants from the Agios Dimitrios lignite-fired power plant in northern Greece show a very strong linear correlation with the free calcium oxide content of the lignite ash. Dust (fly ash) emissions are positively correlated to free calcium oxide content, whereas sulfur dioxide (SO2) emissions are negatively correlated. As a result, at present, the Agios Dimitrios Power Plant operates very strictly within the legislative limits on atmospheric particulate emission. In the present study, the factors to be considered in assessing the impact of lignite combustion on the environment are presented and evaluated statistically. The ash appears to have a remarkable SO2 natural dry scrubbing capability when the free calcium oxide content ranges between 4 and 7%. Precipitator operating problems attributable to high ash resistivity can be overcome by injecting sulfur trioxide to reduce the ash resistivity, with, of course, a probable increase in operating costs.

The silicon phthalocyanine Pc 4 was tested as a photosensitizer for the selective photoinactivation of malignant cells in bone marrow transplantation samples. Using a murine model system, incubation of 1.5×107 cells/mL with 15 nM Pc 4 followed by exposure to red light (λ&gt;600 nm, fluence of 18 J/cm2) was shown to result in a greater than 6 log10 reduction of the clonogenic growth for the murine cell lines ABE-8.1/2, BC3A and L1210. The clonogenic growth of WEHI-3 and P815 cells was reduced by more than 5 log10 and more than 3 log10, respectively. Late murine hematopoietic progenitor cells were less sensitive than cancer cells; the surviving fractions were 0.084 for the colony forming unit, megakaryocyte (CFU-Mk); 0.038 for the colony forming unit, granulocyte macrophage (CFU-GM); 0.0018 for the colony forming unit, mix (CFU-mix) and &lt;0.003 for burst forming units, erythroid (BFU-E). Early hematopoietic progenitor cells, assayed by the in vitro cobble stone area forming cell assay, were not affected by the photodynamic treatment. Likewise, in vivo assays of early hematopoietic progenitor cells showed no reduction of their ability to repopulate the bone marrow. Irradiation of the samples following incubation of 1.5×106 cells/mL with Pc 4 resulted in increased photosensitivity of all cell types, including the early and late hematopoietic progenitor cells. Flow cytometric analysis of Pc 4 uptake by the cells revealed that the increased photosensitivity could be traced to increased Pc 4 uptake; however, Pc 4 uptake among cell types did not correlate with photosensitivity. When mixed with bone marrow (BM) cells, Pc 4 uptake in the cell lines increased as the fraction of BM increased from 0.5 to 0.95. These observations suggest that Pc 4 may be a suitable photosensitizer for bone marrow purging. © 1998 Society of Photo-Optical Instrumentation Engineers.

Kinetics of hydrolysis of aqueous dispersions of arsono-, sulfo-, phosphono- and phospholipids by phospholipase A2 from pig pancreas are characterized in terms of interfacial rate and equilibrium parameters. The enzyme with or without calcium binds with high affinity to the aqueous dispersions of the four classes of anionic lipids and shows the same general kinetic behavior. The rate of hydrolysis of anionic substrates does not show an anomalous change at the critical micelle concentration because the enzyme is present in aggregates even when bulk of the substrate is dispersed as a solitary monomer. Apparent affinities of the enzyme for the interface of different anionic lipids are virtually the same. Also, affinities of these substrates for the active site of the enzyme at the interface are comparable. However, a significant change in the catalytic turnover rate is seen as the sn-3 phosphodiester group is modified; the apparent maximum rate at saturating bulk substrate concentration, V(M)app values, increase in the order: homo- and arsonolipids < sulfo- < phosphono- < phospholipids. Not only the basis for the sn-2 enantiomeric selectivity but also the decrease in the rate of hydrolysis with the increasing chain length is due to a decrease in the value of V(M)app. Results show that even when the bulk concentration of anionic phospholipid is below cmc, hydrolysis occurs in aggregates of enzyme and substrate where the chemical step of the turnover cycle remains rate-limiting, which provides a basis for the assumption that V(M)app is directly related to Kcat. The fact that Kcat depends on the nature of the head group (phosphate, phosphonate, sulfate, arsonate) implies that the head group plays a critical role in the rate-limiting chemical step of the catalytic cycle, possibly during the decomposition of the tetrahedral intermediate. The significance of these results for the microscopic steady-state condition for hydrolysis at the micellar interface, mechanism of esterolysis by phospholipase A2, and inhibitor design are discussed.

Donor cell leukemia after BMT has been documented in a small number of cases mainly by cytogenetic studies. We describe a case of leukemia relapse in a 16-year-old girl 1 year after BMT from her histocompatible brother. Relapse in donor cells was initially suspected on the basis of cytogenetic analysis and confirmed by DNA in situ hybridization in blast cells using a Y chromosome-specific probe.