Insights from the Greek experience of the use of Blinatumomab in pediatric relapsed and refractory acute lymphoblastic leukemia patients.

Pediatric refractory or relapsed acute lymphoblastic leukemia (ALL) poses unique therapeutic challenges, with novel immunotherapy approaches offering potential cure opportunities. In this frame, the use of Blinatumomab may induce durable remissions, serving as a successful bridge to allogeneic hematopoietic stem cell transplantation (allo-HSCT). Herein, we retrospectively summarize the Greek experience on pediatric relapsed/refractory B-cell precursor ALL patients that were treated with Blinatumomab in a compassionate, off-label setting as an effort to achieve disease clearance and proceed to allo-HSCT. In our cohort of 9 patients, 6/9 (66.7%) responded to Blinatumomab, achieving complete morphological remission (CR) after the 1st cycle, while minimal/measurable residual disease (MRD)-negativity (<10-4) after the 1st cycle was achieved in 2/2 patients (100.0%) with prior CR. A successful bridge to HSCT was feasible in 5/9 patients (55.6%). Median relapse-free survival (RFS) was 3.0 months (range 0.5-21.4 months) and median overall survival (OS) was 8.7 months (range 1.4-47.1 months) for the whole pediatric cohort. There was a trend of prolonged survival among patients who achieved MRD response after the 1st Blinatumomab administration. MRD response (defined as the >=2-log reduction of MRD value before and after Blinatumomab administration), was associated with a median RFS/OS of 7.4/7.6 months, while lack of MRD response was associated with a median RFS/OS of 0.5/3.0 months, respectively. Novel therapeutic maneuvers, in order to overcome disease resistance, i.e. increased usage of Blinatumomab dose (45 µg/m2/day), combination with donor lymphocyte infusions (DLIs), use of other immunotherapy salvage approaches (inotuzumabozogamicin), are herein discussed. Additionally, the optimal number of Blinatumomab cycles, the CD19-negative relapses and lineage switch, are also addressed. Our data although referred to a limited, however refractory or relapsed and heavily pretreated number of patients, strongly suggest that Blinatumomab may well induce sustained remissions and serve as an effective bridge to HSCT. Whether immunotherapy combined with chemotherapy can outweigh the need for subsequent allo-HSCT, if incorporated into frontline high-risk ALL therapy, remains an optimistic issue to be verified in future randomized clinical trials.

Influence of incubation conditions on the formation of model biofilms by Listeria monocytogenes and Salmonella Typhimurium on abiotic surfaces.

AIMS: This research aims to develop strongly adherent and mature model biofilms (on a 20 cm² polystyrene surface) for two pathogenic species, i.e. Listeria monocytogenes and Salmonella Typhimurium. These model biofilms can be used as standards to study biofilms or to study/compare the influence of different inactivation technologies. METHODS AND RESULTS: Three influencing factors on the formation of biofilms are investigated, i.e. growth medium, incubation temperature and incubation time, which are three easily controllable environmental factors. Optical density measurement and plate counts were used to evaluate the adherence and the maturity of the biofilms, respectively. Confocal laser scanning microscopy was used to verify most important findings obtained with previously mentioned assays. Results indicated that mature and strongly adherent L. monocytogenes biofilms are obtained following 13 h of incubation at 30°C with BHI as growth medium. For S. Typhimurium, an incubation period of 19 h at 25°C was required with 20-fold diluted TSB as growth medium. CONCLUSIONS: Based on previously mentioned assays, a protocol for the formation of reproducible model biofilms was obtained. SIGNIFICANCE AND IMPACT OF THE STUDY: The developed model biofilms can be applied as a standard to study biofilms (in different research fields) and their subsequent inactivation by different methods. In addition, the results of this study could be used to control biofilm formation (e.g. by setting a maximum allowed surface temperature).

Ultra-Structural Alterations in In Vitro Produced Four-Cell Bovine Embryos Following Controlled Slow Freezing or Vitrification.

Cryopreservation is the process of freezing and preserving cells and tissues at low temperatures. Controlled slow freezing and vitrification have successfully been used for cryopreservation of mammalian embryos. We investigated the effect of these two cryopreservation methods on in vitro produced four-cell stage bovine embryos which were classified according to their quality and separated into three groups. The first group was maintained as untreated controls (n = 350). Embryos of the second (n = 385) and the third (n = 385) groups were cryopreserved either by controlled slow freezing or by vitrification. Embryos in groups 2 and 3 were thawed after 1 day. Hundred embryos were randomly selected from the control group, and 100 morphologically intact embryos from the second and third group were thawed after 1 day and cultured to observe the development up to the blastocyst stage. The blastocyst development rate was 22% in the control group, 1% in the slow-freezing group and 3% in the vitrification group. Remaining embryos of all three groups were examined by light microscopy, transmission electron microscopy and immunofluorescence confocal microscopy with subsequent histological staining procedures. Cryopreservation caused degenerative changes at the ultra-structural level. Compared with vitrification, slow freezing caused an increased mitochondrial degeneration, cytoplasmic vacuolization, disruption of the nuclear and plasma membrane integrity, organelle disintegration, cytoskeletal damage, a reduced thickness of the zona pellucida and a formation of fractures in the zona pellucida. Further studies are required to understand and decrease the harmful effects of cryopreservation.

History of Maternal Fetal Loss and Childhood Leukaemia Risk in Subsequent Offspring: Differentials by Miscarriage or Stillbirth History and Disease Subtype.

BACKGROUND: Despite the putative intrauterine origins of childhood (0-14 years) leukaemia, it is complex to assess the impact of perinatal factors on disease onset. Results on the association of maternal history of fetal loss (miscarriage/stillbirth) with specific disease subtypes in the subsequent offspring are in conflict. We sought to investigate whether miscarriage and stillbirth may have different impacts on the risk of acute lymphoblastic leukaemia (ALL) and of its main immunophenotypes (B-cell and T-cell ALL), as contrasted to acute myeloid leukaemia (AML). METHODS: One thousand ninety-nine ALL incidents (957 B-ALL) and 131 AML cases along with 1:1 age and gender-matched controls derived from the Nationwide Registry for Childhood Hematological Malignancies and Brain Tumors (1996-2013) were studied. Multivariable regression models were used to assess the roles of previous miscarriage(s) and stillbirth(s) on ALL (overall, B-, T-ALL) and AML, controlling for potential confounders. RESULTS: Statistically significant exposure and disease subtype-specific associations of previous miscarriage(s) exclusively with AML [odds ratio (OR) 1.67, 95% confidence interval (CI) 1.00, 2.81] and stillbirth(s) with ALL [OR 4.82, 95% CI 1.63, 14.24] and B-ALL particularly, emerged. CONCLUSION: Differential pathophysiological pathways pertaining to genetic polymorphisms or cytogenetic aberrations are likely to create hostile environments leading either to fetal loss or the development of specific leukaemia subtypes in subsequent offspring, notably distinct associations of maternal miscarriage history confined to AML and stillbirth history confined to ALL (specifically B-ALL). If confirmed and further supported by studies revealing underlying mechanisms, these results may shed light on the divergent leukemogenesis processes.

Socioeconomic disparities in survival from childhood leukemia in the United States and globally: a meta-analysis.

BACKGROUND: Despite advancements in the treatment of childhood leukemia, socioeconomic status (SES) may potentially affect disease prognosis. This study aims to evaluate whether SES is associated with survival from childhood leukemia. METHODS: The US National Cancer Institute Surveillance, Epidemiology and End Results Program (SEER) 1973-2010 data were analyzed; thereafter, results were meta-analyzed along with those from survival (cohort) studies examining the association between SES indices and survival from childhood leukemia (end-of-search date: 31 March 2014). Random-effects models were used to calculate pooled effect estimates (relative risks, RRs); meta-regression was also used. RESULTS: We included 29 studies yielding 28 804 acute lymphoblastic leukemia (ALL), 3208 acute myeloblastic leukemia (AML) and 27 650 'any' leukemia (denoting joint reporting of all subtypes) cases. According to individual-level composite SES indices, children from low SES suffered from nearly twofold higher death rates from ALL (pooled RR: 1.83, 95% confidence interval 1.00-3.34, based on four study arms); likewise, death RRs derived from an array of lower area-level SES indices ranged between 1.17 and 1.33 (based on 11 study arms). Importantly, the survival gap between higher and lower SES seemed wider in the United States, with considerably (by 20%-82%) increased RRs for death from ALL in lower SES. Regarding AML, poorer survival was evident only when area-level SES indices were used. Lastly, remoteness indices were not associated with survival from childhood leukemia. CONCLUSION: Children with lower SES suffering childhood leukemia do not seem to equally enjoy the impressive recent survival gains. Special health policy strategies and increased awareness of health providers might minimize the effects of socioeconomic disparities.

Effects of Metoclopramide and Ranitidine on survival of flat template McFarlane skin flaps in a rat wound healing model.

Wound healing re-provides the morphological integrity after trauma. We investigated the effects of Metoclopramide and Ranitidine on survival of flat template McFarlane skin flaps in an experimental wound healing model.Rats (n:32) were randomly allocated in following groups: Flap control (Control), Metoclopramide(MET), Ranitidine(RAN) and Metoclopramide+Ranitidine (MET+RAN). After flap elevation, ip 10 mg/kg Ranitidin or 5 mg/kg Metoclopramide or the combination of both drugs were administered for 3 days. Next analgesia was maintained. No additional drugs were used for controls. On 10th day, whole cut skin flaps were excised, fixed in buffered formaldehyde and processed with histological techniques. Paraffine sections were stained with Hematoxylen-Eosin, Mallory-Azan and immunohistochemically with Desmin and Fibronectin and then evaluated with light microscopy.Experimental groups showed differences for epidermal degeneration, edema, hypertrophy of the hair follicles, neutrophil infiltration and areolar degeneration. Metoclopramide or Ranitidine administration positively impacts wound healing.This unique study emphasizes the importance of considering Metoclopramide or Ranitidine for possible adverse effects on flap survival in surgical clinics, therefore the combination of both drugs is not more effective.

Nephrotic syndrome and Hodgkin lymphoma in children. Report of two cases.

BACKGROUND: The association of nephrotic syndrome (NS) and Hodgkin's lymphoma (HL), although rare, is well recognised. In the majority of cases of HL, minimal change NS is detected. DESCRIPTION OF CASES: This report presents the occurrence of NS in two children with HL. In the first case, NS preceded the diagnosis of lymphoma by 3 months, while in the other child, the two disorders occurred simultaneously. In both cases, clinical manifestations and laboratory parameters (proteinuria) of NS resolved after effective treatment for active HL. CONCLUSION: Prolonged proteinuria may be a paraneoplastic syndrome and HL should be considered in the diagnosis as it is crucial for the management of both entities.

Childhood leukaemias and lymphomas in Greece (1996-2006): a nationwide registration study.

BACKGROUND: Monitoring time trends in the incidence of childhood leukaemias and lymphomas requires efficient and continuous data collecting systems. In countries without official cancer registries, such as Greece, ad hoc nationwide registration of incident childhood leukaemias and lymphomas could help elucidate the underlying aetiology and monitor socioeconomic differentials in health care delivery. METHODS: We registered all cases and produced age, gender, type and immunophenotype specific figures and overall crude and age adjusted annual incidence rates and secular trends for 863 leukaemia and 311 lymphoma incident cases diagnosed in children <15 years of age across Greece during 1996-2006, namely the first 11 years of the Nationwide Registry for Childhood Hematological Malignancies. RESULTS: The epidemiological profiles of leukaemias/lymphomas in Greece are similar to those in industrialised countries. No secular trends are observed for either malignancy during the studied period. However, the calculated incidence for leukaemia (46.60 cases per 1 million children annually) is among the highest in the EU-27 (19% higher than average; p<0.001), whereas that for lymphoma (16.8 cases per 1 million children annually) is around the EU-27 average. CONCLUSIONS: Minimal secular changes in childhood leukaemias/lymphomas have been noted recently in the EU-27, which cannot be easily explained in countries with small populations. Therefore, centralised EU databases such as the Automated Childhood Cancer Information System (ACCIS) should be enlarged to generate sufficient statistical power for monitoring time trends. It would be interesting to explore whether different lifestyle patterns across the EU might be responsible for the observed excess leukaemia incidence in countries such as Greece.

Effect of temperature during the incubation period on tibial growth plate chondrocyte differentiation and the incidence of tibial dyschondroplasia.

Tibial dyschondroplasia (TD) is one of the most prevalent skeletal abnormalities in avian species, causing enormous economic losses and major animal welfare problems. Irregular cell differentiation of the chondrocytes that populate the growth plate has been hypothesized to be involved in the etiology of the disease. We evaluated the effect of incubation temperature at various stages of embryo development and bone formation on growth plate chondrocyte differentiation and the incidence of TD. Eggs were incubated either at a control temperature of 37.8 degrees C, or at 36.9 or 39 degrees C, each for 6 h/ d, during early (0 to 8 d) or late (10 to 18 d) embryo development. At 14 d of incubation and at hatch, tibias were collected and weighed, and their ash and calcium contents were determined. Growth plate chondrocyte differentiation was evaluated by alkaline phosphatase activity and collagen type II and osteopontin gene expression. In addition, the level of the heat-shock protein 90 (Hsp90) was evaluated by immunohistochemistry. The rest of the chicks were raised to 49 d and the incidence of TD was recorded. The incidence of TD increased only when the temperature was altered at the early stages of embryo development, and it was correlated with an increase in tibia ash but not with tibia weight or calcium content. Moreover, increased TD incidence was correlated with delayed chondrocyte differentiation. Early changes in incubation temperature caused an increase in the level of Hsp90 in articular and differentiated chondrocytes of the hypertrophic zone and in the numbers of distinct undifferentiated chondrocytes arranged in columns in the proliferative zone of the growth plate. In summary, the early stages of embryo development and bone formation are of utmost importantance for appropriate growth plate chondrocyte differentiation, and any temperature deviation will increase the subsequent incidence of TD. The increase in TD incidence is probably the result of delayed Hsp90-driven chondrocyte differentiation, supporting the hypothesis that TD is the result of abnormal chondrocyte differentiation.

An integrated evaluation of socioeconomic and clinical factors in the survival from childhood acute lymphoblastic leukaemia: a study in Greece.

An evaluation of the role of socioeconomic factors in the survival of children with leukaemia, controlling for major clinical prognostic indicators, has been attempted in very few studies and the role of these factors may be different in various cultural settings. Our investigation aims to study the independent role of socioeconomic factors on the prognosis of childhood acute lymphoblastic leukaemia (ALL) in Greece. During a 7-year period (1996-2002) 293 cases of incident ALL were diagnosed and followed up in four Childhood Haematology-Oncology Units, which covered over half of all childhood ALL cases nationwide. At the time of diagnosis, information concerning age, gender, maternal schooling, maternal marital status, sibship size, distance of residence from the treating centre, attendance of day care centre and clinical information was recorded. The influence of these factors on survival was studied by modelling the data through Cox's proportional-hazards regression. After adjustment for clinical prognostic factors, children of mothers who were not currently married, were of low educational level or were living far from the treating centre tended to have lower survival (P-values 0.02, 0.14 and 0.08, respectively). There was also evidence that two factors that are predictive of disease occurrence, that is sibship size and attendance of day care centre, may also predict survival (P-values 0.04 and 0.26, respectively). In conclusion, socioeconomic factors are likely to influence survival from ALL at least in some sociocultural contexts. Moreover, there is evidence that factors that could affect incidence of ALL through modulation of herd immunity may also have prognostic implications for this disease.

Supplementation with Saccharomyces boulardii ameliorates hypoxia/reoxygenation-induced necrotizing enterocolitis in young mice.

Intestinal bacterial proliferation is an important aspect of gastrointestinal injury in neonatal necrotizing enterocolitis (NEC). In the present investigation, we examined the protective action of oral supplementation with Saccharomyces boulardii (S. boulardii), non-pathogen probiotic yeast, against hypoxia-reoxygenation (H/R)-induced NEC in young mice. Young mice were divided into three groups; Group 1 mice (untreated) were subjected only to hypoxia-reoxygenation; Group 2 mice were subjected to hypoxia-reoxygenation and were then given lyophilized S. boulardii (10 mg suspended in 0.5 ml saline) twice a day by orogastric intubation for 10 days. Group 3 mice served as controls. Hypoxia was induced by placing young mice in a 100 % CO (2) chamber for 5 min. After hypoxia, the young mice were reoxygenated for 10 min with 100 % oxygen. We examined the intestinal lesions by light microscopy and measured intestinal generation of PAF and TNF-alpha in the H/R-induced model of NEC. In the probiotic group, NEC-induced intestinal tissue damage was greatly attenuated, with necrosis partially limited to the mucosa. Both intestinal tissue PAF and TNF-alpha concentrations were significantly higher in the untreated group than in controls (p < 0.001). S. boulardii-supplemented young mice showed a significant decrease in intestinal generation of PAF compared with untreated young mice (p < 0.05). On the other hand, no significant difference was observed in the intestinal concentration of TNF-alpha between untreated and probiotic groups ( p > 0.05). The present study suggests that hypoxia/reoxygenation plays an important role in the pathogenesis of NEC and supports hypothesis that especially PAF and TNF-alpha are involved in the pathophysiological mechanism of H/R-induced NEC. This study also demonstrates that dietary supplementation with S. boulardii ameliorates the histologic evidence of H/R-induced intestinal injury. Based on these findings, the beneficial effects of probiotic S. boulardii in this model of NEC are mediated via mechanisms inhibiting intestinal proinflammatory mediator release.

The effect of dietary supplementation with n-3 polyunsaturated fatty acids on the generation of platelet-activating factor and leukotriene B4 in hypoxic-ischemic brain in young mice.

Platelet-activating factor (PAF), leukotriene B(4) (LTB(4)) and other cytokines have been indicated to be responsible for the neuronal damage in hypoxic-ischemic brain. Diets in omega-3 (n-3) fatty acids appear to have an antiinflammatory effect, which is thought to be due to decrease in active prostaglandins and leukotrienes production after incorporation of these fatty acids into cell membrane phospholipids. We investigated the effect of dietary supplementation with n-3 fatty acids on endogenous PAF and LTB(4) biosynthesis in hypoxic-ischemic brain of young mice. Young mice were randomly divided into four groups: Group 1 mice were fed standard chow (n-3 polyunsaturated fatty acids free); Group 2 and Group 3 mice were given standard diet supplemented with 10% by weight of fish oil, as source of n-3 polyunsaturated fatty acids, for 3 and 6 weeks, respectively. Group 4 mice served as control. We injured the right cerebral hemisphere of young mice by ligating the right common carotid artery and exposing the mice to 8% oxygen for 60 min. Approximately 10-fold increase in PAF concentration was determined in hypoxic-ischemic brain tissue of Group 1 mice. Tissue concentration of PAF showed a profound decline in Group 3 mice compared to Groups 1 and 2 (P<0.01, P<0.05, respectively). LTB(4) was also significantly elevated in the brain of Group 1 mice when compared to the brain of control mice (P<0.001). A striking decline was observed in the concentration of LTB(4) in both Group 2 and Group 3 mice compared to Group 1 mice (P<0.05, P<0.01, respectively). The present study shows that n-3 fatty-acid-enriched diet inhibits endogenous PAF and LTB(4) generation in hypoxic-ischemic brain tissue; however it demonstrates that 6 weeks of dietary supplementation with n-3 fatty acids results in a significant decrease in tissue level of PAF in the brain.

Comparison of isepamicin with amikacin for the empirical treatment of febrile neutropenic children with malignancies.

The efficacy and safety of isepamicin at 7.5 mg/kg i.v. q 12 h was prospectively compared with that of amikacin at the same dose for the treatment of febrile neutropenic children with malignancies. Thirty-nine patients were enrolled in the study; 25 received isepamicin and 14 amikacin. Clinical and bacteriological response rates were 100% for both groups. No adverse events occurred. Median peak serum levels were 19.7 mg/l for isepamicin and 19.20 mg/l for amikacin. Median trough serum levels were 0.72 mg/l for isepamicin and 0.68 mg/l for amikacin. It was concluded that isepamicin was as effective and safe as amikacin for the treatment of febrile neutropenic children with malignancies, and might be used in areas where resistance to other aminoglycosides is a problem.

The role of recombinant human erythropoietin in lipid peroxidation and platelet-activating factor generation in a rat model of necrotizing enterocolitis.

In the present study we examined the effect of recombinant human erythropoietin (rhEPO) on intestinal malondialdehyde (MDA) as an index of lipid peroxidation, related to iron-catalysed free radical reaction and platelet-activating factor (PAF) synthesis in the experimental model of necrotizing enterocolitis (NEC). Three groups, each consisting of eight 1-day-old Wistar albino rat pups, were studied; Group 1, hypoxia-reoxygenation; Group 2, hypoxia-reoxygenation and rhEPO pretreatment; Group 3, control. rhEPO was given 750 U/kg/week by intraperitoneal injection three times a week for 2 weeks. On day 15th of life, hypoxia was induced by placing rat pups in a 100% CO2 chamber for 5 min. After hypoxia, the rat pups were reoxygenated for 10 min with 100% oxygen and returned to their mothers. All pups were killed at 4h following hypoxia-reoxygenation. The abdomen was opened and representative samples of injured areas were taken for histopathologic examination. MDA and PAF levels were determined in the intestine. Significantly increased intestinal MDA content was found in Group 1 rat pups compared to Group 2 and Group 3 pups (p < 0.001 and p < 0.001, respectively). However, PAF concentrations were highly elevated in the intestine of Group 1 and Group 2 pups (p>0.05) when compared to the intestine of Group 3 pups (p < 0.001 and p < 0.001, respectively). Histopathologic findings did not differ between Groups 1 and 2. The present study demonstrates that oxygen-derived free radicals and PAF are involved in the pathophysiological mechanism of the development of NEC. This study also shows that administration of rhEPO significantly decreases lipid peroxidation; however, PAF generation was not inhibited in hypoxia-induced bowel necrosis.

Effect of dietary n-3 fatty acids on hypoxia-induced necrotizing enterocolitis in young mice. n-3 fatty acids alter platelet-activating factor and leukotriene B4 production in the intestine.

Necrotizing entercolitis (NEC) is an important neonatal disease with a high mortality rate. Inflammatory mediators, such as mainly platelet-activating factor (PAF), leukotrienes (LT) and tumor necrosis factor play an important role in the genesis of NEC. Diets in omega-3 (n-3) fatty acids appear to have an antiinflammatory effect, which is thought to be due to decreased active prostaglandins and leukotrienes production after incorporation of these fatty acids into cell membrane phospholipids. We investigated the protective effect of fish oil (source of n-3 fatty acids) on hypoxia-induced model of NEC. Young mice were divided into three groups; group 1 mice were fed standard chow (n-3 fatty acids-free), group 2 was fed a chow supplemented by 10% fish oil for 4 weeks. Group 3 mice served as control. We examined the intestinal lesions by light microscopy and measured intestinal tissue PAF and LB4 levels in hypoxia-induced model of NEC. Significantly increased intestinal PAF and LTB4 levels were found in group 1 mice when compared to group 2 and group 3 mice. The histopathology of the intestinal lesions in group 1 animals was characteristic of ischemic injury. In the n-3 fatty acids-supplemented animals these lesions were milder. The present study shows that endogenously released PAF and LTB4 play an important role in mediating hypoxia-induced intestinal necrosis. The present study also suggests that dietary supplementation with n-3 fatty acids suppress intestinal PAF and LTB4 generation in hypoxia-induced bowel necrosis. The intestinal protective effect of n-3 fatty acids in an experimental model of NEC may open new insight into the treatment and prevention of NEC in neonates.

Establishment and characterization of a hepatoblastoma cell-line from a patient with secondary acute myeloid-leukemia.

A girl who had been treated, apparently successfully, with surgery and chemotherapy for a hepatoblastoma, fell ill two years later with what was diagnosed as an AMF M(4). A cell line was established from her peripheral blood. This cell line had epithelial morphology and grew both in suspension culture and as a monolayer. The cells were positive for epithelial surface markers, including the liver-specific alpha-fetoprotein, but not for leukocyte markers. The cell-line's karyotype was markedly abnormal. It did not have any specific aneuploidies or any other aberrations characteristic of leukemias; instead it had gains of 2q and chromosome 20, the most common cytogenetic changes in hepatoblastoma. It is most likely that the patient had a relapse of hepatoblastoma with massive seeding of the blood leading to a leukemia-like picture without, of course, excluding other possibilities.