Evaluation of circulating microparticles in healthy medical workers occupationally exposed to ionizing radiation: A preliminary study.

OBJECTIVES: Ionizing radiation was known to cause disruption of cytoskeleton. However, the disorganization of the cytoskeleton leads to form microparticles (MP) that carry membrane and cytoplasmic constituents from their parent cells they are released from. Therefore, authors investigated the effect of the occupational exposure to low doses of ionizing radiation on MP levels. MATERIAL AND METHODS: The current study was conducted on 38 healthy medical workers occupationally exposed to low doses of ionizing radiation and 29 controls matched by gender, age, and smoking habits. The MP levels measured by flow cytometry were classified as positive or negative phosphatidylserine (PS+ or PS-), and phenotyped according to their cellular origin. RESULTS: Total MP (PS-/PS+) levels, regardless of phenotype, were significantly higher in workers occupationally exposed to ionizing radiation than in healthy individuals (p = 0.0004). Negative phosphatidylserine microparticles were predominant in medical exposed workers and, to a lesser extent, in controls (68% and 57%, respectively). With regard to phenotypic characterization of cellular origin, MP derived from platelets (CD41a+), endothelial (CD146+), leucocytes (CD45+) and erythrocytes (CD235a+) MP were significantly enhanced in exposed workers compared with controls (p < 0.0001). However, no significant difference was found in the proportion of the other blood elements in the peripheral circulation between the 2 groups. Serum levels of C-reactive protein were normal for all individuals. In addition, no association was observed between MP levels and the studied confounding factors. CONCLUSIONS: The results suggest that elevated circulating MP levels represent an indicator of cellular damage caused by medical exposure to low doses of ionizing radiation. By consequence, the quantification of MP seems to be a useful biomarker for assessing the negative effects of occupational exposure to ionizing radiation. Int J Occup Med Environ Health 2018;31(6):783-793.

Circulating endothelial cells and microparticles as diagnostic and prognostic biomarkers in small-cell lung cancer.

OBJECTIVES: It has been proposed that circulating endothelial cells (CECs) and microparticles (MPs) may be useful for the assessment of patients with non-small-cell lung cancer (NSCLC). However, little is known about the potential clinical relevance of these biomarkers in small-cell lung cancer (SCLC). Therefore, we investigated the utility of baseline levels of CECs and MPs in SCLC patients. MATERIALS AND METHODS: An immunomagnetic separation (IMS) technique was used to isolate and quantify CECs in the peripheral blood, while plasma samples were analyzed using flow cytometry for the measurement of circulating MPs. RESULTS: We prospectively collected data from 56 patients and 41 healthy individuals. Forty-three patients presented at initial diagnosis and 13 patients presented at relapse. Baseline levels of CECs and MPs were significantly higher in SCLC patients either at initial diagnosis or at relapse than in healthy subjects (p < 0.0002 and p < 0.007, respectively). However, estimated tumor volume (ETV) was significantly correlated with basal MP values (p < 0.0001) but not with pretreatment CECs (p = 0.57). The amount of baseline CECs and MPs was significantly lower in patients with an objective response (OR, n = 23) than in those with progressive disease (PD, n = 15) after treatment (p = 0.016 and 0.05, respectively). With cut-off values of 110 cells/mL for CECs and 1257 events/µL for MPs according to receiver operating characteristics (ROC) analysis, baseline levels of these biomarkers were not significantly correlated with either progression-free survival (PFS) or overall survival (OS). However, patients with 6-month PFS displayed significantly decreased pretreatment CEC counts (p = 0.042), whereas basal MP values significantly increased in 1-year survivors compared with those in non-survivors (p = 0.05). CONCLUSION: Our results suggest that baseline CECs and MPs may be predictive biomarkers of tumor response and long-term survival in SCLC patients.

HLA class I alleles frequencies in the Syrian population.

OBJECTIVE: The HLA system is known to be the most polymorphic genetic loci in humans. Distribution and frequencies of HLA alleles are highly variable among different human ethnic groups. The HLA system has an important role in disease susceptibility and resistance, especially in autoimmune diseases and cancer. This study is the first report about HLA genetic variability and haplotypes among Syrians. Frequency of the HLA class I (A, B and C) alleles was determined in 105 healthy unrelated Syrian individuals from different regions in Syria. We also studied the associated haplotypes frequencies. Alleles frequencies were compared with those reported for other populations. RESULTS: Fifty-eight HLA class I alleles were observed in Syrians including 15 for HLA-A, 28 for HLA-B and 15 for HLA-C. We observed 37 HLA-A/C haplotypes, 32 B/C, and 31 A/B haplotypes. The most frequent haplotypes were A*01/C*04, A*02/C*07, A*02/B*35, and B*35/C*04. In conclusions, our preliminary study suggests a high variability in HLA class I alleles in the Syrian population. This study also gives a general reference database about the genetic pool distribution of HLA class I alleles among Syrians and can be consulted for HLA related diseases.

Circulating endothelial cells and microparticles for prediction of tumor progression and outcomes in advanced non-small cell lung cancer.

BACKGROUND: Circulating endothelial cells (CECs) and microparticles (MPs) are proposed as useful biosensors for angiogenesis and membrane damage in cancer. OBJECTIVE: We investigated their predictive value for progression disease (PD) and clinical outcomes in advanced non-small cell lung cancer (NSCLC) patients treated with cytotoxic chemotherapy. METHODS: Peripheral blood samples were obtained from 60 patients. Immunomagnetic separation (IMS) and flow cytometry techniques were used to quantify CECs and MPs, respectively. Receiver operating characteristics (ROC) analysis was used to determine the optimal cutoff values for CECs and MPs counts according to their levels in patients with an objective response (OR) and non-responders after treatment. Baseline serum biomarkers levels and their kinetics after chemotherapy were correlated with tumor response and outcomes in advanced NSCLC patients. RESULTS: Forty-seven patients presented an OR after chemotherapy. Of these, 28 patients progressed within three months. Through an increase in their levels during or after chemotherapy, CECs and MPs correctly predicted PD in 57% and 61% of these patients, respectively. Regarding tumor stage, NSCLC patients with stage IV had significantly higher pretreatment CECs and MPs levels than stage III patients (p= 0.037 and 0.018, respectively). Moreover, progression-free survival (PFS) was significantly longer in patients with high baseline CECs levels than those with low pretreatment CECs values (p= 0.05). Moreover, patients with high percentage change in CECs count after chemotherapy had significantly longer time to progression (TTP) duration (p= 0.018). CONCLUSIONS: Our findings suggest the increase in CECs and MPs number during or after chemotherapy as predictive biomarkers of tumor progression in advanced NSCLC patients. An association of basal CECs and MPs values with tumor stage was also shown in advanced NSCLC patients. However, baseline CECs levels and their kinetics after chemotherapy seem to be prognostic factors in advanced NSCLC.

Frequency of HLA-DRB1 and HLA-DQB1 Alleles and Haplotype Association in Syrian Population.

The study of Human Leukocyte Antigen (HLA) system is very important in health and diseases. As the HLA loci are the most polymorphic in the human genome, it plays a very important role in the immune responses to self and nonself antigens. In the light of the growing importance of typing the HLA alleles in transplantation, autoimmune diseases, cancer, and many other diseases, we studied 225 unrelated healthy Syrian subjects for their HLA class II genotypes in an attempt to reveal the distribution of the HLA (DRB1-DQB1) alleles in the general Syrian population. Our results revealed that the most common alleles for the DRB1 locus were DRB1*11 (26.4%), DRB1*04 (14%), and DRB1*07 (12%). However, the most frequent alleles for the DQB1 locus were DQB1*03 (40.9%) and DQB1*05 (25.1%). The frequent of two-locus haplotypes carry the most frequent alleles at these loci. The most frequently detected class II ''haplotypes'' are DRB1*11-DQB1*03 (8.9%), DRB1*01-DQB1*05 (3.6%), and DRB1*04-DQB1*03 (2.7%). Compared with other populations, our result, deduced from the analysis of genetic distances and the construction of neighbor-joining (NJ) dendrogram, and principal component analysis (PCA) indicates that Syrians are related to Middle Eastern populations. Our data about the Syrian population will aid researchers in studying the relation of HLA class II with different diseases in a Syrian population and will add to the available international literature associated with these loci.

Deletion 9p23 to 9p11.1 as sole additional abnormality in a Philadelphia positive chronic myeloid leukemia in blast crisis: a rare event.

BACKGROUND: Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by the presence of a derivative chromosome 22 [der(22)] commonly called Philadelphia chromosome (Ph). The Ph chromosome is a product of the reciprocal translocation t(9;22)(q34.1;q11.2). Additional genetic changes occur in less than 10 % of CML cases at the time of diagnosis and other genetic changes are seen in 60-80 % of the cases in advanced disease. Even though deletions in chromosome 9 are not rare findings in advanced phase-CML, del(9)(p23p11.1) as sole additional abnormality detected by fluorescence in situ hybridization (FISH) technique, to our knowledge has not been described in the literature. RESULTS: A complete cytogenetic and molecular cytogenetic analysis, molecular biology method (reverse transcription polymerase chain reaction (RT-PCR)), and immunophenotype confirmed to be a CML case in blast crisis (BC). It revealed del(9)(p23p11.1) as sole abnormality detected by FISH technique besides Ph chromosome, which leads to monoallely of tumor suppressor gene CDKN2A (cyclin-dependent kinase inhibitor 2A) before Imatinib mesylate (IM) treatment. CONCLUSIONS: The patient did not demonstrate a good response to IM treatment. The underlying mechanisms and prognostic implications of these cytogenetic abnormalities are discussed.

Whole-body γ-irradiation decelerates rat hepatocyte polyploidization.

PURPOSE: To characterize hepatocyte polyploidization induced by intermediate dose of γ-ray. MATERIALS AND METHODS: Male Wistar strain rats were whole-body irradiated (WBI) with 2 Gy of γ-ray at the age of 1 month, and 5-6 rats were sacrificed monthly at 0-25 months after irradiation. The nuclear DNA content of individual hepatocytes was measured by flow cytometry, then hepatocytes were classified into various ploidy classes. RESULTS: Survival percentage, after exposure up to the end of the study, did not indicate any differences between the irradiated groups and controls. The degree of polyploidization in hepatocytes of irradiated rats, was significantly lower than that for the control after 1 month of exposure, and it continued to be lower after up to 8 months. Thereafter, the degree of polyploidization in the irradiated group slowly returned to the control level when the irradiated rats reached the age of 10 months. CONCLUSION: Intermediate dose of ionizing radiation, in contrast to high doses, decelerate hepatocyte polyploidization, which may coincides with the hypothesis of the beneficial effects of low doses of ionizing radiation.

Hyperdiploidy associated with T315I mutation in BCR-ABL kinase domain in an accelerated phase-chronic myeloid leukemia case.

BACKGROUND: Chronic myeloid leukemia (CML) is genetically characterized by the occurrence of a reciprocal translocation t(9;22)(q34;q11), resulting in a BCR/ABL gene fusion on the derivative chromosome 22, i.e. the Philadelphia (Ph) chromosome. During CML progression 60-80% of the cases acquire additional genetic changes. Even though hyperdiploidy is not a rare finding in advanced phase-CML, hyperdiploidy together with a T315I kinase domain (KD) mutation in the BCR-ABL gene has not yet been reported. RESULTS: A complete cytogenetic and molecular cytogenetic analysis; molecular biology methods such as quantitative reverse transcription polymerase chain reaction (RQ-PCR) and allele-specific oligonucleotide (ASO)-PCR; and immunophenotypically confirmed CML in acceleration phase (AP). Our case revealed the presence of hyperdiploidy including multiple copies of the Ph chromosome, presence of b3a2 fusion transcript,T315I mutation in BCR-ABL KD in pre imatinib mesylate (IM) treatment. The ratio of BCR-ABL/ABL expression in post nilotinib treatment was 0.07% on international scale. CONCLUSIONS: The patient demonstrated a good response to nilotinib after imatinib failure; while the hyperdiploid clone disappeared the T315I mutation remained during follow-up. The underlying mechanisms and prognostic implications of these cytogenetic abnormalities are discussed.

Three-way Philadelphia translocation t(9;10;22)(q34;p11.2;q11.2) as a secondary abnormality in an imatinib mesylate-resistant chronic myeloid leukemia patient.

Chronic myelogenous leukemia (CML) is characterized by the Philadelphia (Ph) chromosome created by the reciprocal translocation t(9:22)(q34;q11), resulting in the chimeric gene breakpoint cluster region (BCR)-Abelson (ABL). Variant Ph chromosome translocations involving chromosomes other than 9 and 22 occur in 5-10% of CML cases. In the present study, a novel case of a Ph chromosome-positive CML in the chronic phase (CP) is reported, with a three-way Ph translocation involving three chromosomal regions, 9q34, 10p11.2 and 22q11.2, in addition to the loss of the Y chromosome, where the latter was a secondary abnormality. Since the majority of CML cases are currently treated with imatinib, variant rearrangements generally have no specific prognostic significance, although the mechanisms involved in resistance to therapy have yet to be investigated. The underlying mechanisms and prognostic implications of these cytogenetic abnormalities are discussed in the present study.