Detection of SV40 DNA sequences in malignant mesothelioma specimens from the United States, but not from Turkey

The incidence of malignant mesothelioma (MM) shows a strong epidemiological association with exposure to asbestos fibers. Recently, simian virus 40 (SV40) DNA sequences have been reported in MM tumor specimens from the United States and several European countries, and the SV40 tumor virus has been implicated as a potential co-factor in the etiology of this disease. However, several large studies from the US, Finland, and Turkey did not detect SV40 sequences in MM samples. To address this discrepancy, MM specimens from Turkey and the US were analyzed in the same laboratory under identical conditions to detect the presence of SV40 DNA. We detected SV40 sequences in 4 of 11 specimens from the United States, but in none of the 9 Turkish samples examined. These findings suggest that geographical differences exist with regard to the involvement of SV40 in human tumors.     

Topical dimethyl sulfoxide inhibits corneal neovascularization and stimulates corneal repair in rabbits following acid burn

Neovascularization of the cornea is characterized by the growth of blood vessels caused by imbalances between angiogenic and anti-angiogenic factors. We investigated whether the expression of Vascular endothelial growth factor (VEGF), Vascular endothelial growth factor receptor (VEGF), Vascular endothelial growth inhibitor (VEGI) receptors, as well as topical drug treatments, participate in regulating corneal neovascularization after corneal damage and remodeling. We used 72 mature male New Zealand rabbits. Corneal burns were induced by hydrofluoric acid under general anesthesia. The rabbits then were treated with indomethacin or dimethyl sulfoxide (DMSO). The animals were euthanized on days 2, 7 and 14 after injury. Each cornea was fixed with 10% neutral formalin. On days 2, 7 and 14, VEGF, flk1/KDR and flt1/fms were strongly expressed in the epithelial, stromal and inflammatory cells, but not in the corneal endothelial cells. On day 7, newly formed blood vessels were observed growing toward the center of the cornea. In the control, indomethacin treated, DMSO–treated, and indomethacin + DMSO–treated animals, VEGI, VEGF, and the receptors, flk1/KDR, flt1/fms and flt4, were expressed at different densities in the neovascular regions. This was particularly evident in the indomethacin- and indomethacin + DMSO–treated groups on days 7 and 14, compared to day 2. Treatment with VEGF and DMSO stimulated repair of corneal damage. We suggest that VEGI in the endothelial cells of neovascularized cornea may act as a signaling protein that promotes balance between cell proliferation and apoptosis. Topical administration of DMSO inhibited corneal neovascularization more effectively than indomethacin.     

Identification of major soluble salivary gland proteins in teneral Glossina morsitans morsitans

Salivary glands of tsetse flies (Diptera: Glossinidiae) contain molecules that are involved in preventing blood clotting during feeding as well as molecules thought to be intimately associated with trypanosome development and maturation. Here we present a protein microchemical analysis of the major soluble proteins of the salivary glands of Glossina morsitans morsitans, an important vector of African trypanosomes. Differential solubilization of salivary proteins was followed by reverse-phase, high-performance liquid chromatography (HPLC) and analysis of fractions by 1-D gel electrophoresis to reveal four major proteins. Each protein was subjected to amino acid microanalysis and N-terminal microsequencing. A protein chemical approach using high-resolution 2-D gel electrophoresis and mass spectrometry was also used to identify the salivary proteins. Matrix-assisted, laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and quadrupole time-of-flight (Q-TOF) tandem mass spectrometry methods were used for peptide mass mapping and sequencing, respectively. Sequence information and peptide mass maps queried against the NCBI non-redundant database confirmed the identity of the first protein as tsetse salivary gland growth factor-1 (TSGF-1). Two proteins with no known function were identified as tsetse salivary gland protein 1 (Tsal 1) and tsetse salivary gland protein 2 (Tsal 2). The fourth protein was identified as Tsetse antigen-5 (TAg-5), which is a member of a large family of anti-haemostatic proteins. The results show that these four proteins are the most abundant soluble gene products present in salivary glands of teneral G. m. morsitans. We discuss the possible functions of these major proteins in cyclical transmission of African trypanosomes.     

<Emphasis Type="Italic">FHIT</Emphasis> Gene Sequence Variants and Reduced Fhit Protein Expression in Glioblastoma Multiforme

Molecular studies have an important role in the elucidation of the mechanisms involved in Glioblastoma multiforme (GBM) development. The occurrence of FHIT gene alterations, which has an important role in different cancers, has not yet been studied well in GBM. We aimed to investigate the occurrence of alterations of FHIT gene sequence and protein expression in the GBMs. Sequence alterations in exons 5–9 of the FHIT gene were screened in 63 GBMs using the single-strand conformational polymorphism method, followed by DNA sequencing. Additionally, the level of Fhit protein expression in tissues of 48 tumors was assessed by immunohistochemistry (IHC). In our investigation, FHIT gene alterations in the coding region were detected in 11 of the 63 GBM cases (17.5%). Two different sequence variants were determined: one novel missense variant (G→C transition at codon 49) and one previously described silent alteration (C→T transition at codon 88). Using web-based programs, such as SIFT and ESEfinder, it was determined that both alterations might have caused significant modification on protein function. In addition, we identified a previously reported an intronic polymorphism (T→A transition at IVS8-17) in 47.5% of cases as a similar rate (45%) in the control group. Moreover, it was observed that Fhit protein expression was reduced in 87.5% of tumors. In conclusion, the reduction or loss of Fhit protein expression by genetic alterations or epigenetic mechanisms in GBM might be associated with brain tumorigenesis.     

Morphological and anatomical studies on economically important Empetrum nigrum L. subsp.hermaphroditum (hagerup) bocher (empetraceae)

The study is based on anatomical and morphological investigations of Empetrum nigrum L. subsp. Hermaphroditum (Hagerup) Bocher, an important plant because of its value for medicine and food. Plant samples were collected from the northeastern part of Turkey. Morphological and anatomical features of various plant parts (e.g., stem, leaf, flower, and fruit) are illustrated and described in detail.     

Investigation of the pharmacokinetics of gemcitabine and 2',2'-difluorodeoxyuridine in human plasma by liquid chromatography

Gemcitabine (2',2'-difluorodeoxycytidine, dFdC) is a difluorine-substituted deoxycytidine analogue that has demonstrated antitumor activity against solid tumors. The pharmacokinetics of dFdC and its metabolite, 2',2'-difluorodeoxyuridine (dFdU) have been studied; however, their disposition has never been evaluated in a patient with bladder cancer. A patient with bladder cancer was treated with dFdC 1000 mg/m(2) over a 30min period. The patient received a dFdC infusion once per week for 3 weeks followed by a rest week. Serial plasma samples were obtained prior to, during, and after completion of the infusion for determination of dFdC and dFdU concentrations. dFdC and dFdU concentrations were measured using normal-phase high-performance liquid chromatography and one-compartment open model methods. Maximum plasma concentrations (C(max)) and area under the plasma concentration-time curve for dFdC and dFdU were 24.5 microg/ml and 11200 microg/Lh, 49.1 microg/ml and 272,800 microg/Lh, respectively.     

Kinetic analysis of a Golgi UDP-GlcNAc:polypeptide-Thr/Ser N-acetyl-alpha-glucosaminyltransferase from Dictyostelium

Mucin-type O-glycosylation in Dictyostelium is initiated in the Golgi by a UDP-GlcNAc:polypeptide-Thr/Ser N-acetyl-alpha-glucosaminyltransferase (Dd-pp alphaGlcNAcT2) whose sequence is distantly related to the sequences of animal polypeptide-Thr/Ser N-acetyl-alpha-galactosaminyltransferases, such as murine Mm-pp alphaGalNAcT1. To evaluate the significance of this similarity, highly purified Dd-pp alphaGlcNAcT2 was assayed using synthetic peptides derived from known substrates. Dd-pp alphaGlcNAcT2 strongly prefers UDP-GlcNAc over UDP-GalNAc, preferentially modifies the central region of the peptide, and modifies Ser in addition to Thr residues. Initial velocity measurements performed over a matrix of UDP-GlcNAc donor and peptide acceptor concentrations indicate that the substrates bind to the enzyme in ordered fashion before the chemical conversion. Substrate inhibition exerted by a second peptide, and the pattern of product inhibition exerted by UDP, suggest that UDP-GlcNAc binds first and the peptide binds second, consistent with data reported for Mm-pp alphaGalNAcT1. Two selective competitive inhibitors of Mm-pp alphaGalNAcT1, retrieved from a screen of neutral-charge uridine derivatives, also inhibit Dd-pp alphaGlcNAcT1 competitively with only slightly less efficacy. Inhibition is specific for Dd-pp alphaGlcNAcT2 relative to two other Dictyostelium retaining glycosyltransferases. These data support a phylogenetic model in which the alphaGlcNAcT function in unicellular eukaryotes converted to an alphaGalNAcT function in the metazoan ortholog while conserving a similar reaction mechanism and active site architecture.     

Impact of Laboratory Test Use Strategies in a Turkish Hospital

ObjectivesEliminating unnecessary laboratory tests is a good way to reduce costs while maintain patient safety. The aim of this study was to define and process strategies to rationalize laboratory use in Ankara Numune Training and Research Hospital (ANH) and calculate potential savings in costs.MethodsA collaborative plan was defined by hospital managers; joint meetings with ANHTA and laboratory professors were set; the joint committee invited relevant staff for input, and a laboratory efficiency committee was created. Literature was reviewed systematically to identify strategies used to improve laboratory efficiency. Strategies that would be applicable in local settings were identified for implementation, processed, and the impact on clinical use and costs assessed for 12 months.ResultsLaboratory use in ANH differed enormously among clinics. Major use was identified in internal medicine. The mean number of tests per patient was 15.8. Unnecessary testing for chloride, folic acid, free prostate specific antigen, hepatitis and HIV testing were observed. Test panel use was pinpointed as the main cause of overuse of the laboratory and the Hospital Information System test ordering page was reorganized. A significant decrease (between 12.6–85.0%) was observed for the tests that were taken to an alternative page on the computer screen. The one year study saving was equivalent to 371,183 US dollars.ConclusionHospital-based committees including laboratory professionals and clinicians can define hospital based problems and led to a standardized approach to test use that can help clinicians reduce laboratory costs through appropriate use of laboratory tests.     

Determinants of Human African Trypanosomiasis Elimination via Paratransgenesis

Human African trypanosomiasis (HAT), transmitted by tsetse flies, has historically infected hundreds of thousands of individuals annually in sub-Saharan Africa. Over the last decade, concerted control efforts have reduced reported cases to below 10,000 annually, bringing complete elimination within reach. A potential technology to eliminate HAT involves rendering the flies resistant to trypanosome infection. This approach can be achieved through the introduction of transgenic Sodalis symbiotic bacteria that have been modified to produce a trypanocide, and propagated via Wolbachia symbionts, which confer a reproductive advantage to the paratransgenic tsetse. However, the population dynamics of these symbionts within tsetse flies have not yet been evaluated. Specifically, the key factors that determine the effectiveness of paratransgenesis have yet to be quantified. To identify the impact of these determinants on T.b. gambiense and T.b. rhodesiense transmission, we developed a mathematical model of trypanosome transmission that incorporates tsetse and symbiont population dynamics. We found that fecundity and mortality penalties associated with Wolbachia or recombinant Sodalis colonization, probabilities of vertical transmission, and tsetse migration rates are fundamental to the feasibility of HAT elimination. For example, we determined that HAT elimination could be sustained over 25 years when Wolbachia colonization minimally impacted fecundity or mortality, and when the probability of recombinant Sodalis vertical transmission exceeded 99.9%. We also found that for a narrow range of recombinant Sodalis vertical transmission probability (99.9–90.6% for T.b. gambiense and 99.9–85.8% for T.b. rhodesiense), cumulative HAT incidence was reduced between 30% and 1% for T.b. gambiense and between 21% and 3% for T.b. rhodesiense, although elimination was not predicted. Our findings indicate that fitness and mortality penalties associated with paratransgenic symbionts, as well as tsetse migration rates, are instrumental to HAT elimination, and should be a key focus in the development of paratransgenic symbionts.