Exposure of aquatic organisms to natural radionuclides in irrigation drains, Qena, Egypt.

Natural radioactivity in irrigation drains was measured by gamma spectrometry, and the resulting dose rates received by aquatic organisms were estimated. Irrigation water and sediment samples were collected from 5 irrigation drains located in Qena governorate, south of Egypt. The average activity concentrations (Bq L-1) of 226Ra, 232Th, and 40 K in irrigation water were 0.76 ± 0.06, 0.27 ± 0.02, and 8.14 ± 0.71, while in sediment (Bq kg-1) were 24.46 ± 1.84, 20.72 ± 1.45, and 453.00 ± 28.14, respectively. The total dose rate per aquatic organism ranged from 1.94 × 10-04 µGy h-1 in Mollusc to 7.15 × 10-04 µGy h-1 in phytoplankton. These values are far from the international recommended limit 400 µGy h-1 for chronic exposure to aquatic organisms, and the dose rate screening value of 10 µGy h-1 suggested by ERICA tool. Based on these results, it is unlikely that harmful effects will appear on the considered aquatic organisms due to exposure to natural radioactivity in the studied environment.

Chaperonin GroEL a Brucella immunodominant antigen identified using Nanobody and MALDI-TOF-MS technologies.

The deployment of today's antibodies that are able to distinguish Brucella from the closely similar pathogens, such as Yersinia, is still considered a great challenge since both pathogens share identical LPS (lipopolysaccharide) O-ring epitopes. In addition, because of the great impact of Brucella on health and economy in many countries including Syria, much effort is going to the development of next generation vaccines, mainly on the identification of new immunogenic proteins of this pathogen. In this context, Brucella-specific nanobodies (Nbs), camel genetic engineered heavy-chain antibody fragments, could be of great value. Previously, a large Nb library was constructed from a camel immunized with heat-killed Brucella. Phage display panning of this 'immune' library with Brucella total lysate resulted in a remarkable fast enrichment for a Nb referred to as NbBruc02. In the present work, we investigated the main characteristics of this Nb that can efficiently distinguish under well-defined conditions the Brucella from other bacteria including Yersinia. NbBruc02 showed a strong and specific interaction with its antigen within the crude lysate as tested by a surface plasmon resonance (SPR) biosensor and it was also able to pull down its cognate antigen from such lysate by immuno-capturing. Using matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), NbBruc02 specific antigen was identified as chaperonin GroEL, also known as heat shock protein of 60 kDa (HSP-60), which represents a Brucella immunodominant antigen responsible of maintaining proteins folding during stress conditions. Interestingly, the antigen recognition by NbBruc02 was found to be affected by the state of GroEL folding. Thus, the Nb technology applied in the field of infectious diseases, e.g. brucellosis, yields two outcomes: (1) it generates specific binders that can be used for diagnosis, and perhaps treatment, and (2) it identifies the immunogenic candidate antigens for developing vaccines.

Evaluation of a nanobody phage display library constructed from a Brucella-immunised camel.

Brucella are invasive gram-negative bacteria that multiply and survive within eukaryotic cells causing brucellosis. Syrian (and Middle East) health and economy sectors are still affected by this disease causing a serious national problem that needs to be solved. Here, a strategy was developed to introduce a new generation of binders, known as Nanobodies (Nbs) in our combat against Brucella. These Nbs, recombinant single-domain variable fragments derived from camelid heavy-chain antibodies are very stable and highly soluble, making them a useful tool in numerous biotechnological and medical applications. In this work and without having access to purified antigens (Ags), a camel was immunised successfully with heat-killed Brucella melitensis strain Riv1 as demonstrated by the high titer of Ag-specific heavy-chain antibodies in the serum. Lymphocytes of the immunised camel were isolated and their Nb genes were cloned in a relatively large library of 10(8) individual transformants, of which 81% contained an insert with the proper size of a Nb gene. Phage display expression of the Nbs from this library and pannings on the Brucella lysate resulted in a clear enrichment of three distinct Nb-displaying phages (phage-Nbs), referred to as NbBruc01, 02 and 03, with specificity for Brucella. Producing these binders in a pure, soluble form, as well as identifying their specific targets, which are likely to be immunodominant Ags in Brucella, is expected to open wide perspectives for following the vaccination, diagnosis and treatment of brucellosis.

Heat production rate from radioactive elements in igneous and metamorphic rocks in Eastern Desert, Egypt.

Radioactive heat-production data of Igneous and Metamorphic outcrops in the Eastern Desert are presented. Samples were analysed using a low level gamma-ray spectrometer (HPGe) in the laboratory. A total of 205 rock samples were investigated, covering all major rock types of the area. The heat-production rate of igneous rocks ranges from 0.11 (basalt) to 9.53 microWm(-3) (granite). In metamorphic rocks it varies from 0.28 (serpentinite ) to 0.91 microWm(-3) (metagabbro). The contribution due to U is about 51%, as that from Th is 31% and 18% from K. The corresponding values in igneous rocks are 76%, 19% and 5%, respectively. The calculated values showed good agreement with global values except in some areas containing granites.

Indoor radon measurement with The Lucas cell technique.

Rn-222 is the most important source of natural radiation and is responsible for approximately half of the received dose from all sources. Most of this dose is from inhalation of the Rn-222 progeny, especially in closed atmospheres. A Lucas cell technique, using a portable device, "PRASSI" (SILENA mod. 5S), for Rn-222 measurements inside the Centre for Radiation Protection and Radioecology (ZSR), Hannover University was used. The portable radon monitor PRASSI is suitable for radon gas continuous or grab sampling measurements with the scintillation cell technique. In recognition of the wide periodic variations in concentration, measurements were made daily for extended periods. At the same time, meteorological variables, such as temperature and humidity were observed so that their influence on radon levels could be evaluated. The radon average concentration during the year was about 55.9 Bq/m3 which gives rise to an annual effective dose 2.2 mSvy(-1). The radon concentration is within the limits prescribed by the International Commission for Radiation Protection. A detailed analysis of radon distribution with seasonal variation is presented.

ICBP90 belongs to a new family of proteins with an expression that is deregulated in cancer cells.

ICBP90 (Inverted CCAAT box Binding Protein of 90 kDa) is a recently identified nuclear protein that binds to one of the inverted CCAAT boxes of the topoisomerase IIalpha (TopoIIalpha) gene promoter. Here, we show that ICBP90 shares structural homology with several other proteins, including Np95, the human and mouse NIRF, suggesting the emergence of a new family of nuclear proteins. Towards elucidating the functions of this family, we analysed the expression of ICBP90 in various cancer or noncancer cell lines and in normal or breast carcinoma tissues. We found that cancer cell lines express higher levels of ICBP90 and TopoIIalpha than noncancer cell lines. By using cell-cycle phase-blocking drugs, we show that in primary cultured human lung fibroblasts, ICBP90 expression peaks at late G1 and during G2/M phases. In contrast, cancer cell lines such as HeLa, Jurkat and A549 show constant ICBP90 expression throughout the entire cell cycle. The effect of overexpression of E2F-1 is more efficient on ICBP90 and TopoIIalpha expression in noncancer cells (IMR90, WI38) than in cancer cells (U2OS, SaOs). Together, these results show that ICBP90 expression is altered in cancer cell lines and is upregulated by E2F-1 overexpression with an efficiency depending on the cancer status of the cell line.

Repeated transurethral resection of recurrent superficial bladder tumors--does it affect the spread and stage of the tumor?

OBJECTIVES: This prospective study was done to demonstrate the effect of repeated resection of superficial bladder tumors (TURT) on deep malignant cell infiltration in bladder wall. MATERIAL AND METHODS: Thirty-six patients underwent radical cystectomy for invasive bladder cancer, 16 patients originally had superficial cancer that became invasive after repeated TURT (group I) and the other 20 patients (group II) presented with invasive bladder cancer from the start. Each cystectomy specimen was subjected to a thorough histopathological study. RESULTS: There was a statistically significant difference in pattern of local spread of malignant cells between the two groups. Isolated clusters of malignant cells in-between normal bladder muscle fibers, isolated subserosal malignant deposits as well as cells reaching the adjacent cervix uteri were found only in group I. Intravesical pressure was measured in another 10 patients during TURT and was found to be high reaching up to 80 cm H2O. CONCLUSIONS: We conclude that some malignant cells penetrate through the denuded urothelium during TURT by the effect of high intravesical pressure. This may be responsible, among other factors, for tumor recurrence with deeper stages.