Array comparative genomic hybridization analysis of olfactory neuroblastoma.

Olfactory neuroblastoma is an unusual neuroectodermal malignancy, which is thought to arise at the olfactory membrane of the sinonasal tract. Due to its rarity, little is understood regarding its molecular and cytogenetic abnormalities. The aim of the current study is to identify specific DNA copy number changes in olfactory neuroblastoma. Thirteen dissected tissue samples were analyzed using array comparative genomic hybridization. Our results show that gene copy number profiles of olfactory neuroblastoma samples are complex. The most frequent changes included gains at 7q11.22-q21.11, 9p13.3, 13q, 20p/q, and Xp/q, and losses at 2q31.1, 2q33.3, 2q37.1, 6q16.3, 6q21.33, 6q22.1, 22q11.23, 22q12.1, and Xp/q. Gains were more frequent than losses, and high-stage tumors showed more alterations than low-stage olfactory neuroblastoma. Frequent changes in high-stage tumors were gains at 13q14.2-q14.3, 13q31.1, and 20q11.21-q11.23, and loss of Xp21.1 (in 66% of cases). Gains at 5q35, 13q, and 20q, and losses at 2q31.1, 2q33.3, and 6q16-q22, were present in 50% of cases. The identified regions of gene copy number change have been implicated in a variety of tumors, especially carcinomas. In addition, our results indicate that gains in 20q and 13q may be important in the progression of this cancer, and that these regions possibly harbor genes with functional relevance in olfactory neuroblastoma.     

RT-PCR-RFLP for genetic diversity analysis of Tunisian Grapevine fanleaf virus isolates in their natural host plants

Genetic diversity was characterized in 20 isolates of Grapevine fanleaf virus (GFLV) recovered from naturally infected grapevine plants (Vitis vinifera) in the North of Tunisia. Viral RNAs were isolated by oligoprobe capture, and a 605 bp fragment containing a part of the viral coat protein gene was amplified by RT-PCR. Sequence variation among isolates was characterized by restriction fragment length polymorphism (RFLP) analysis and confirmed by sequencing. The GFLV infections are found as a complex mixture of closely related genomes. In further studies, RFLP analyses of virus isolates using AluI showed that GFLV populations in Tunisian vineyards consist of two restrictotypes corresponding to distinct sub-populations Sp1 and Sp2. The relative field distribution of these sub-populations showed that Sp2 was more abundant. Individual genomes were recovered by cloning the RT-PCR products. The sequences were found to vary from each other by as much as 11%. Cloning from mixed infections showed that Sp2 are also predominant.     

Analysis of MHC genes in a Tunisian isolate with autoimmune thyroid diseases: implication of TNF -308 gene polymorphism

Autoimmune thyroid diseases (AITDs), which include Hashimoto thyroiditis (HT), Graves' disease (GD) and primary idiopathic myxoedema (PIM), are recognized as multifactorial diseases. In this study, we have examined single and haplotypic genetic variation across the major histocompatibility complex (MHC) in a Tunisian isolate with a high prevalence of AITDs (62 patients: 32 with GD, 9 with HT and 21 with PIM). Genotyping was performed for HLA class I and II alleles as well as polymorphisms within tumor necrosis factor (TNF), lymphotoxin alpha (TLalpha) and heat shock protein (HSP70-02 and HSP70-hom) genes. Our results showed association of HLA-A2-B50-TNF 2 haplotype with AITDs (p = 0.045). Linkage analysis using Simwalk2 program has shown significant result with TNF -308 gene polymorphism (p = 0.03). The FBAT has given evidence for genetic association with TNF -308 and HLA-DR gene polymorphisms. TNF 2 allele was associated with GD (p = 0.0011), whereas TNF 1, HLA-DR11 and DR12 (p = 0.0039, p = 0.00089 and p = 0.0056, respectively) were rather implicated in HT pathogenesis. Results found by TDT-STDT have confirmed the involvement of the TNF -308 gene polymorphism in AITD pathogenesis (p < 10(-9)).     

Expression of luminal and basal cytokeratins in human breast carcinoma

We have examined basal and luminal cell cytokeratin expression in 1944 cases of invasive breast carcinoma, using tissue microarray (TMA) technology, to determine the frequency of expression of each cytokeratin subtype, their relationships and prognostic relevance, if any. Expression was determined by immunocytochemistry staining using antibodies to the luminal cytokeratins (CKs) 7/8, 18 and 19 and the basal markers CK 5/6 and CK 14. Additionally, assessment of alpha-smooth muscle actin (SMA) and oestrogen receptor status (ER) was performed. The vast majority of the cases showed positivity for CK 7/8, 18 and 19 indicating a differentiated glandular phenotype, a finding associated with good prognosis, ER positivity and older patient age. In contrast, basal marker expression was significantly related to poor prognosis, ER negativity and younger patient age. Multivariate analysis showed that CK 5/6 was an independent indicator for relapse free interval. We were able to subgroup the cases into four distinct phenotype categories (pure luminal, mixed luminal/basal, pure basal and null), which had significant differences in relation to the biological features and the clinical course of the disease. Tumours classified as expressing a basal phenotype (the combined luminal plus basal and the pure basal) were in a poor prognostic subgroup, typically ER negative in most cases. These findings provide further evidence that breast cancer has distinct differentiation subclasses that have both biological and clinical relevance.     

Disturbances of Haemostasis in Diabetes Mellitus

Diabetes mellitus is associated with disturbances in haemostasis that could contribute to the development of thrombotic complications.The present study was undertaken to determine the behavior of coagulation variables and fibrinolytic system in diabetes mellitus. Forty five diabetic patients and forty five matched controls were evaluated by doing the following haemostatic parameter, prothrombin time, partial thromboplastin time, thrombin time, coagulation factors assay II, VII, IX, & plasma fibrinogen, ADP-induced platelet aggregation, protein C, a₂- antiplasmin, PAI and FDPs. Generally diabetic patients have high levels of fibrinogen, a₂- antiplasmin, & PAI and lower level of protein C. Other haemostatic parameters did not show statistically significant difference between diabetic patients and control group. Significantally elevated levels of PAI, a₂- antiplasmin together with low protein C level in diabetic patients may result in the disturbance of haemostatic balance favoring thrombotic events. Conclusion: High levels of plasma fibrinogen, a₂A- antiplasmin with low plasma protein C activity could lead to a prothrombotic tendency in insulin dependent diabetic patients. Moreover, in non-insulin dependent diabetic patients, the above mentioned parameters together with high levels of ADP-induced platelet aggregation and plasminogen activator inhibitor may increase the risk of thrombotic complications. Obesity can be considered as an additional risk factor for development of thrombosis in diabetic patients.     

Altered chromatin landscape in circulating T follicular helper and regulatory cells following grass pollen subcutaneous and sublingual immunotherapy

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Chryseomonas luteola identified as the source of serious infections in a Moroccan University Hospital

Chryseomonas luteola has only rarely been reported as a human bacterial pathogen. It has been shown that this organism in particular affects patients with health or indwelling disorders. Most reported cases showed septicemia, meningitis, endocarditis, or peritonitis. Two C. luteola infections observed in Morocco are described in the present study.     

Temperature-mediated heteroduplex analysis for detection of pncA mutations associated with pyrazinamide resistance and differentiation between Mycobacterium tuberculosis and Mycobacterium bovis by denaturing high- performance liquid chromatography

The goal of this study was to apply temperature-mediated heteroduplex analysis using denaturing high-performance liquid chromatography to identify pyrazinamide (PZA) resistance in Mycobacterium tuberculosis isolates and simultaneously differentiate between M. tuberculosis and Mycobacterium bovis. Features that contributed to an optimal assay included the use of two different reference probes for the pncA gene targets from wild-type M. tuberculosis and wild-type M. bovis, optimization of the column temperature, increasing the starting concentration of the elution buffer, and reducing the rate of elution buffer increase (slope). A total of 69 strains were studied, including 48 wild-type M. tuberculosis strains (13 were PZA-resistant strains) and 21 M. bovis strains (8 were BCG strains). In all isolates tested, wild-type M. tuberculosis generated a single-peak pattern when mixed with the M. tuberculosis probe and a double-peak pattern with the M. bovis probe. In contrast, all M. bovis isolates generated a double-peak pattern when mixed with the M. tuberculosis probe and a single-peak pattern with the M. bovis probe. PZA-resistant mutant M. tuberculosis isolates generated characteristic patterns that were easily distinguishable from both wild-type M. tuberculosis and M. bovis isolates. Chromatographic patterns generated by the two reference probes allowed the rapid detection of PZA resistance with the simultaneous ability to distinguish between M. tuberculosis and M. bovis. This approach may allow the detection of drug resistance-associated mutations, with potential application to clinical and epidemiological aspects of tuberculosis control.     

Monkey interferon: Activity on human cells and chromatographic properties

Summary Monkey interferon (MKIF) produced in monkey BSC-1 cells infected with Newcastle disease virus showed antiviral activity on human foreskin fibroblasts and RD114 cells—a human line transformed by feline sarcoma virus. The titer of the monkey interferon in human cells was 10–30 fold greater than that found in several normal monkey (BSC-1, CV-1) or SV40 transformed (C2, C6, T-22) monkey cell lines tested. Ten to fifteen-fold purification of MKIF without loss of activity could be achieved by chromatography on Phenyl-Sepharose CL-4B. Antiviral activity of MKIF was fully resistant to treatment with 1 per cent sodium dodecyl sulfate (SDS).With 1 Figure