East Mediterr Health J
July 2000
The University of Basra Medical College introduced a course on medical ethics for undergraduate students in 1994. We explored the opinions of 54 graduates and 52 final-year medical students about the benefits they perceive they gained from the course and its relevance to their training or practice. About 31% of students and 34% of graduates thought the course was practically and theoretically useful.
View Article and Find Full Text PDFPurpose: To examine the role of mitogen-activated protein kinase (MAPK) signalling on the induction by ionizing radiation of the nucleotide excision repair gene (ERCC1), the X-ray cross-complementing group 1 protein (XRCC1) and the repair of radiation-induced DNA damage.
Materials And Methods: The expression of ERCC1 and XRCC1 was examined in DU145 human prostate cancer cells following exposure to ionizing radiation. We characterized the MAPK dependence of this expression through RT-PCR analysis, Western analysis, transcription inhibition and measurement of the activation of each promoter.
Previously, we have linked prolonged intense mitogen-activated protein kinase (MAP kinase; MAPK) signaling in hepatocytes to increased expression of p21(Cip-1/WAF1/MDA6) (p21) and p16(INK4a) (p16), that leads to a p21-dependent growth arrest. In this study, we investigated the impact of hepatitis B virus X protein (pX) expression on MAPK-modulated cell cycle progression in primary mouse hepatocytes. In hepatocytes, expression of pX enhanced protein levels of p21 and p27, but not of p16.
View Article and Find Full Text PDFBackground: The porcine virus denominated La Piedad Michoacan Virus (LPMV) is a member of the family Paramyxoviridae and is the cause of a disease in pigs present only in Mexico. The disease is characterized by meningoencephalitis and respiratory distress in young pigs, epididymitis and orchitis in boars, and reproductive failure and abortion in sows.
Methods: The cytopathology, morphology, and distribution of the hemagglutination neuraminidase (HN) and nucleoprotein (NP) proteins of LPMV were investigated following inoculation into PK-15 cells.
We investigated the role of radiation-induced mitogen activated protein kinase (MAPK) pathway activity in the regulation of proliferation, cell survival and vascular endothelial growth factor (VEGF) production in primary astrocytes and in T9 and RT2 glioblastoma cells derived from Fisher 344 rats. In these cells, ionizing radiation (2 Gy) caused activation of the MAPK pathway which was blocked by specific inhibitor drugs. Blunting of radiation-induced MAPK activity weakly enhanced radiation-induced apoptosis 24 h after exposure in RT2 cells.
View Article and Find Full Text PDFA dose-limiting toxicity of certain chemotherapeutic alkylating agents is their toxic effects on nontarget tissues such as the bone marrow. To overcome the myelosuppression observed by chemotherapeutic alkylating agents, one approach is to increase the level of DNA repair proteins in hematopoietic stem and progenitor cells. Toward this goal, we have constructed a human fusion protein consisting of O6-methylguanine DNA methyltransferase coupled with an apurinic endonuclease, resulting in a fully functional protein for both O6-methylguanine and apurinic/apyrimidinic (AP) site repair as determined by biochemical analysis.
View Article and Find Full Text PDFThe yeast OGG1 gene was recently cloned and shown to encode a protein that possesses N-glycosylase/AP lyase activities for the repair of oxidatively damaged DNA at sites of 7,8-dihydro-8-oxoguanine (8-oxoguanine). Similar activities have been identified for Escherichia coli formamidopyrimidine-DNA glycosylase (Fpg) and Drosophila ribosomal protein S3. Both Fpg and S3 also contain a deoxyribophosphodiesterase (dRpase) activity that removes 2-deoxyribose-5-phosphate at an incised 5' apurinic/apyrimidinic (AP) sites via a beta-elimination reaction.
View Article and Find Full Text PDFWe recently demonstrated that Drosophila ribosomal protein S3 specifically cleaved duplex oligodeoxynucleotides at sites of 7,8-dihydro-8-oxoguanine (8-oxoGua), presumably due to S3 protein possessing an N-glycosylase activity that is associated with its known apurinic/apyrimidinic (AP) lyase activity. Here we show, using DNA substrates prepared by gamma-irradiation under N2O and analyzed by gas chromatography/isotope-dilution mass spectrometry, that S3 protein efficiently liberates 8-oxoGua as a free base from the damaged DNA substrate. Of the 15 additional modified bases present in the DNA substrate, the only other one acted on by S3 protein was 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua).
View Article and Find Full Text PDFThe human DNA repair protein apurinic/apyrimidinic endonuclease (APE) is a dual-function protein that has important roles in both the repair of baseless sites that arise in DNA and in regulating the redox state of a number of proteins (Ref-1). Although previous attention has been focused on how the human APE/Ref-1 gene may be regulated at the DNA level, we have instead examined if APE/Ref-1 is phosphorylated, and if so how it may affect DNA repair activity. We demonstrate here that APE/Ref-1 is indeed a substrate for phosphorylation by the serine/threonine casein kinases (CK) I and II and protein kinase C.
View Article and Find Full Text PDFThe Drosophila ribosomal protein S3 has been previously demonstrated to cleave DNA containing 8-oxoguanine residues and has also been found to contain an associated apurinic/apyrimidinic (AP) lyase activity that cleaves phosphodiester bonds via a beta, delta-elimination reaction. The activity of this protein on DNA substrates containing incised AP sites was examined. A glutathione S-transferase fusion protein of S3 was found to efficiently remove sugar-phosphate residues from DNA substrates containing 5'-incised AP sites as well as from DNA substrates containing 3'-incised sites.
View Article and Find Full Text PDFA gene encoding the alpha-tubulin of Candida albicans has been cloned and characterized. Nucleotide sequence analysis reveals the presence of an intron within the structural gene and predicts the synthesis of a polypeptide of 448 amino acid residues. Comparison of nucleotide and amino acid sequences with the Saccharomyces cerevisiae alpha-tubulin encoding genes shows a 75% homology and about 92% similarity respectively.
View Article and Find Full Text PDFNucleic Acids Res
November 1996
Drosophila ribosomal protein PO was overexpressed in Escherichia coli to allow for its purification, biochemical characterization and to generate polyclonal antibodies for Western analysis. Biochemical tests were originally performed to see if overexpressed PO contained DNase activity similar to that recently reported for the apurinic/apyrimidinic (AP) lyase activity associated with Drosophila ribosomal protein S3. The overexpressed ribosomal protein was subsequently found to act on AP DNA, producing scissions that were in this case 5' of a baseless site instead of 3', as has been observed for S3.
View Article and Find Full Text PDFIonizing radiation and normal cellular respiration form reactive oxygen species that damage DNA and contribute to a variety of human disorders including tumor promotion and carcinogenesis. A major product of free radical DNA damage is the formation of 8-oxoguanine, which is a highly mutagenic base modification produced by oxidative stress. Here, Drosophila ribosomal protein S3 is shown to cleave DNA containing 8-oxoguanine residues efficiently, The ribosomal protein also contains an associated apurinic/apyrimidinic (AP) lyase activity, cleaving phosphodiester bonds via a beta,delta elimination reaction.
View Article and Find Full Text PDFDenatured type-I collagen was found to bind to Chlamydia trachomatis elementary bodies (EBs) in a time-dependent and specific manner. Specificity was tested by having a large excess of other proteins present in the binding mixture. Only denatured type-I collagen efficiently competed for binding.
View Article and Find Full Text PDFThe nucleotide (nt) sequence of the dihydrofolate reductase (DHFR)-encoding gene (DFR1) of Candida albicans was determined. The gene contains an open reading frame of 576 nt, coding for a protein of 192 amino acid (aa) residues (calculated M(r) 22,222), that is 38.5 and 31% similar to the Saccharomyces cerevisiae and human enzymes, respectively.
View Article and Find Full Text PDFBone sialoprotein (BSP) is selectively bound by Staphylococcus aureus cells isolated from patients suffering from infections of bone and joint tissues [Rydén C., Maxe, I., Franzén, A.
View Article and Find Full Text PDFStaphylococcus aureus arthritis is usually caused by bacteremia and is highly destructive. Controlled studies on septic arthritis in humans are difficult to perform, because the time of onset of the infection is unknown. Animal models of bacterial arthritis make it possible to control important variables in experimental studies.
View Article and Find Full Text PDFTwo high molecular weight staphylococcal proteins, fibronectin-binding protein and a Mr 200,000 protein, were investigated as antigens for serodiagnosis of staphylococcal infections. Sera from patients with staphylococcal infections and from controls were subjected to immunoblot analysis with staphylococcal lysate proteins to identify staphylococcal antigens to which patients with staphylococcal infections specifically exhibited antibodies. One such protein was found in the Mr 200,000 region.
View Article and Find Full Text PDFBone sialoprotein is selectively bound by Staphylococcus aureus cells isolated from patients suffering from infections of bone tissue [Rydén, C., Maxe, I., Franzén, A.
View Article and Find Full Text PDFExperience with the MAGPI (meatoplasty and glanuloplasty) procedure in hypospadias repair, a modification of the procedure, and expanded indications for its use are presented. The excellent cosmetic results attained warrant more widespread use of this procedure.
View Article and Find Full Text PDFAm J Med Genet
January 1987
We report on a sister and a brother (born to normal consanguineous parents) with joint contractures and osteolytic lesions of bones. The sister had also gingival hyperplasia and skin lesions consisting of multiple tumors of the face, nose, palate, ears, and neck. Histologic examination showed findings of juvenile hyaline fibromatosis.
View Article and Find Full Text PDFA comparative seroepidemiological survey of Schistosoma haematobium infection among primary schoolchildren in areas of different levels and patterns of endemicity in Basrah governorate, southern Iraq, also covered all inhabitants of Al-maadan locality, a known endemic focus in Basrah. Blood samples were tested by the enzyme linked immunosorbent assay. Serological data were analysed to describe the pattern of distribution of antischistosomal antibodies, to relate the level of infection to age and sex, and to estimate the force of infection per year by applying age catalytic models.
View Article and Find Full Text PDFAn epidemiological study of Schistosoma haematobium infection in Al-maadan locality, considered to be the main remaining endemic focus in Basrah, southern Iraq was carried out. The association between the serological profile of the population, measured by the enzyme linked immunosorbent assay (ELISA), and various factors including current infection by urine examination, water contact pattern, past history of, and treatment for, schistosomiasis, and cercarial dermatitis was investigated. Further study of the serological data by the relative operating characteristic (ROC) analysis to assess the validity of the ELISA in detecting schistosomal infection, showed that current infection, past history of infection, age, cercarial dermatitis and category of household were significantly associated with the serological profile of the population.
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