Cytogenetic analysis of 298 newly diagnosed cases of acute lymphoblastic leukaemia in Tunisia

Genetic changes associated with Acute Lymphoblastic Leukaemia (ALL) provide diagnostic and prognostic information with a direct impact on patient management. We report the cytogenetic analysis of 298 Tunisian patients with ALL, including 183 children and 115 adults. Chromosome abnormalities have been detected in 68.2% of our patients associating clonal numerical and/or structural rearrangements. Some chromosomal abnormalities especially hyperdiploidy, 19p13 abnormalities, 8q24 translocations, 12p, 6q deletions and TCR rearrangements occur at a lower incidence compared to that reported in other populations. ALL cases (5.7%) had miscellaneous clonal abnormalities. We also found in our Tunisian series a higher incidence for T-lineage ALL more than usually described. Among structural chromosomal abnormalities, t(9;22)(q34;q11) resulting in the BCR/ABL fusion and the t(12;21)(p13;q22) resulting in the TEL/AML1 fusion were studied by FISH providing additional diagnostic and prognostic information. We conclude that although the incidence of our cytogenetic results are slightly different, their clinical significance is similar to that described in the literature.     

Laser-written photonic crystal optofluidics for electrochromatography and spectroscopy on a chip

Femtosecond laser processes were optimized for nonlinear interactions with various optical materials to develop a novel biophotonic lab-on-a-chip device that integrates laser-formed waveguides (WGs), microfluidic channels and photonic crystals (PCs). Such integration seeks the unique demonstration of dual PC functionalities: (1) efficient chromatographic separation and filtration of analytes through a porous PC embedded inside a microfluidic channel and (2) optofluidic spectroscopy through embedded WGs that probe PC stopband shifts as varying analyte concentrations flow and separate. The building blocks together with their integration were demonstrated, providing embedded porous PCs through which electrochromatography drove an accelerated mobile phase of analyte and an optical stopband was probed via integrated buried WGs. Together, these laboratory results underpin the promise of simultaneous chromatographic and spectroscopic capabilities in a single PC optofluidic device.OCIS codes: (130.3120) Integrated optics devices, (140.3390) Laser materials processing, (160.5298) Photonic crystals, (190.4180) Multiphoton processes, (280.4788) Optical sensing and sensors, (280.5715) Refractivity profiles, (320.2250) Femtosecond phenomena     

An unusual three-way translocation t(21;8;1)(q22;q22;q32) in a case of acute myeloid leukemia (M2)

Variant forms of the classic translocation t(8;21) are uncommon and account approximately 3% of all t(8;21)(q22;q22) in acute myeloid leukemia (AML) patients. These forms involve chromosomes 8, 21, and other chromosomes. Here we report a Tunisian patient with a complex rearrangement t(21;8;1)(q22;q22;q32) revealed by conventional chromosomal study at diagnosis. Fluorescence in situ hybridization study revealed the presence of the AML1-ETO chimeric gene on the derivative chromosome 8. To the best of our knowledge, this is the second case of t(21;8;1) of AML-M2 reported in the literature with the involvement of the same breakpoint at 1q32. This illustrates that this complex translocation is rarely encountered in AML and reinforces the fact that this region may harbour a critical gene candidate that may play an important role in the pathogenesis of AML. More cases are needed to elucidate its clinical features and prognosis.     

Correlation of SMN2, NAIP,p44, H4F5 and Occludin genes copy number with spinal muscular atrophy phenotype in Tunisian patients

ObjectivesSpinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder which is characterized by a high clinical variability with severe, intermediate, mild and adult forms. These forms are caused, in 95% of cases, by a homozygous deletion of exon 7 of SMN1 gene. Our purpose was the determination of a possible genotype–phenotype correlation between the copy number of SMN2, NAIP, p44, H4F5 and occludin genes localized in the same SMN1 region (5q13) and the severity of the disease in SMA Tunisian patients.Patients and methodsTwenty six patients affected by SMA were enrolled in our study. MLPA and QMPSF were used to measure copy numbers of these genes.ResultsWe found that 31.3% of type I patients carried one copy of SMN2, while all patients of other forms had at least 2 copies. NAIP was absent in 87.5% of type I patients. Furthermore, all SMA type I patients had one copy of H4F5. No correlation was found for p44 and occludin genes.ConclusionThere is a close relationship between SMN2, NAIP and H4F5 gene copy number and SMA disease severity, which is compatible with the previous reports.     

Metatarsal giant cell tumour in a 7-year-old child: a case report

Giant cell tumours are uncommon benign osseous neoplasias with an obscure origin. They mostly occur in the epiphyses of long bones after skeletal maturity. Occurrence in a metatarsal bone in a child less than 10 years old is quite exceptional. The authors report a case of a 7-year-old girl with an aggressive giant cell tumour of the first metatarsal bone of her right foot. Intralesional excision by curettage and grafting with morselised iliac cortical and cancellous bone was performed. The girl is now disease free since 7 years. Giant cell tumours in this location and age group are rare; they appear to represent a distinct, more aggressive form of tumour. They should be considered in the differential diagnosis of a destructive bony lesion in skeletally immature patients. Curettage and bone grafting with morcelised iliac cortical and cancellous bone remains a treatment option, despite a high potential for recurrence.     

Blue-green algae (Arthrospira platensis) as an ingredient in pasta: free radical scavenging activity, sensory and cooking characteristics evaluation

The effects of semolina enrichment with blue-green algae (Arthrospira platensis) at three different levels (1, 2 and 3 g/100 g of semolina) on the colour, cooking properties, firmness, free radical scavenging activity and sensory characteristics of pasta are reported. Microalgae addition resulted in higher swelling index and lower cooking loss than the control sample. A significant increase in pasta firmness was evidenced with an increase of added microalgae due to structural reinforcement. In addition to colouring, the use of A. platensis (2 g/100 g of semolina) can enhance the sensory quality and nutraceutical potential as evaluated by free radical scavenging activity of pasta.