Effect of hydrogen bonding and complexation with metal ions on the fluorescence of luotonin A

Fluorescence characteristics of a biologically active natural alkaloid, luotonin A (LuA), were studied by steady-state and time-resolved spectroscopic methods. The rate constant of the radiationless deactivation from the singlet-excited state diminished by more than one order of magnitude when the solvent polarity was changed from toluene to water. Dual emission was found in polyfluorinated alcohols of large hydrogen bond donating ability due to photoinitiated proton displacement along the hydrogen bond. In CH 2Cl2, LuA produced both 1:1 and 1:2 hydrogen-bonded complexes with hexafluoro-2-propanol (HFIP) in the ground state. Photoexcitation of the 1:2 complex led to protonated LuA, whose fluorescence appeared at a long wavelength. LuA served as a bidentate ligand forming 1:1 complexes with metal ions in acetonitrile. The stability of the complexes diminished in the series of Cd2+ > Zn2+ > Ag+, and upon competitive binding of water to the metal cations. The effect of chelate formation on the fluorescent properties was revealed. © 2013 The Royal Society of Chemistry and Owner Societies

Molecular staging estimates occult tumor burden in colorectal cancer

Tumor cells in regional lymph nodes are a key prognostic marker of survival and predictive marker of response to adjuvant chemotherapy in colorectal cancer. However, clinicopathologic techniques to detect lymph node metastases remain imperfect, and ~30% of patients with lymph nodes negative by histology (pN0) develop recurrent disease, reflecting occult metastases that escape detection. These observations underscore an unmet clinical need for accurate approaches to identify occult nodal metastases in colorectal cancer patients. GUCY2C is a receptor whose expression normally is restricted to intestinal epithelial cells, but is universally over-expressed by colorectal cancer cells. A prospective, multicenter, blinded clinical trial established the prognostic utility of GUCY2C qRT-PCR to detect occult nodal metastases in pN0 colorectal cancer patients. Molecular staging revealed that ~13% of pN0 patients were free of cancer cells, while ~87% had GUCY2C results that suggested occult metastases. The presence of occult nodal metastases was the most powerful independent predictor of time to recurrence and disease-free survival. These observations establish the utility of molecular detection of occult nodal metastases for assessing prognostic risk in pN0 colorectal cancer patients. Advancing GUCY2C into staging paradigms in clinical laboratories will require validation in independent patient populations, definition of the relationship between the quantity of occult tumor metastases and risk, and determination of the utility of GUCY2C qRT-PCR to identify pN0 patients who might benefit from adjuvant chemotherapy

Kronik Hepatit C Virusu İnfeksiyonunun Yönetimi: Türk Klinik Mikrobiyoloji ve İnfeksiyon Hastalıkları Derneği Viral Hepatit Çalışma Grubu Uzlaşı Raporu

Study Group for Viral Hepatitis of the Turkish Society of Clinical Microbiology and Infectious Diseases convened a meeting to develop a consensus report on management of chronic hepatitis C virus (HCV) infection, a global public health problem, affecting nearly 170 million people worldwide. Relevant literature and international guidelines were reviewed, and recommendations agreed are presented at the end of each section such as epidemiology and natural history of HCV infection, economic burden of chronic hepatitis C (CHC), diagnosis of acute hepatitis C (AHC) and CHC, treatment of AHC, goals, endpoints, stopping rules and pre-therapeutic assessment of CHC therapy, indications for treatment, treatment of CHC, monitoring and managing treatment safety and side effects, measures to improve treatment adherence, posttreatment follow-up of patients who achieve a sustained virological response, contraindications to therapy, retreatment of non-sustained virological responders, follow-up of untreated patients and of patients with treatment failure, and prevention of HCV infection. Examples of some selected recommendations are as follows: [1] It should be kept in mind that approximately 75-85% of people who become infected will develop chronic HCV infection, up to 20% of them develop cirrhosis within 20 years, and the average annual risk of hepatocellular carcinoma among them is 1-4%. [2] In addition to the HCV RNA quantification, the HCV genotype should be assessed to provide relevant information with respect to treatment duration and different response rates prior to treatment initiation. [3] If predicted response rate is not appropriate to any of the existing regimens, the patient should be kept waited until alternative therapeutic options become available

CpG-island methylation of the ER promoter in colorectal cancer: analysis of micrometastases in lymph nodes from UICC stage I and II patients

Patients with UICC stage II colorectal cancer (CRC) have a risk of approximately 20% to develop disease recurrence after tumour resection. The presence and significance of micrometastases for locoregional recurrence in these patients lacking histopathological lymph node involvement on routine stained HE sections is undefined. Oestrogen receptor (ER) promoter methylation has earlier been identified in CRC. Therefore, we evaluated the methylation status of the ER promoter in lymph nodes from 49 patients with CRC UICC stage I and II as a molecular marker of micrometastases and predictor of local recurrence. DNA from 574 paraffin-embedded lymph nodes was isolated and treated with bisulphite. For the detection of methylated ER promoter sequences, quantitative real-time methylation-specific PCR was used. Of the 49 patients tested, 15 (31%) had ER methylation-positive lymph nodes. Thirteen of those (86%) remained disease free and two (14%) developed local recurrence. In the resected lymph nodes of 34 of the 49 patients (69%), no ER promoter methylation could be detected and none of these patients experienced a local relapse. The methylation status of the ER promoter in lymph nodes of UICC stage I and II CRC patients may be a useful marker for the identification of patients at a high risk for local recurrence

Malignant melanoma arising from a perianal fistula and harbouring a BRAF gene mutation: a case report

<p>Abstract</p> <p>Background</p> <p>Melanoma of the anal region is a very uncommon disease, accounting for only 0.2-0.3% of all melanoma cases. Mutations of the <it>BRAF </it>gene are usually absent in melanomas occurring in this region as well as in other sun-protected regions. The development of a tumour in a longstanding perianal fistula is also extremely rare. More frequent is the case of a tumour presenting as a fistula, that is, the fistula being a consequence of the cancerous process, although we have found only two cases of fistula-generating melanomas reported in the literature.</p> <p>Case Presentation</p> <p>Here we report the case of a 38-year-old male who presented with a perianal fistula of four years of evolution. Histopathological examination of the fistulous tract confirmed the presence of malignant melanoma. Due to the small size and the central location of the melanoma inside the fistulous tract, we believe the melanoma reported here developed in the epithelium of the fistula once the latter was already formed. Resected sentinel lymph nodes were negative and the patient, after going through a wide local excision, remains disease-free nine years after diagnosis. DNA obtained from melanoma tissue was analysed by automated direct sequencing and the <it>V600E </it>(<it>T1799A</it>) mutation was detected in exon 15 of the <it>BRAF </it>gene.</p> <p>Conclusion</p> <p>Since fistulae experience persistent inflammation, the fact that this melanoma harbours a <it>BRAF </it>mutation strengthens the view that oxidative stress caused by inflammatory processes plays an important role in the genesis of <it>BRAF </it>gene mutations.</p

Changes in growth parameters and forage quantity and quality of corn harvested at different developmental stages

Due to the different agricultural practices such as second cropping or more for the increase product obtained from the areas of suitable climate, some differences in harvesting stages of plants have been occurred. The study was carried out in the Menemem location of Izmir in the coastal Aegean region of Turkey under Mediterranean climate in 2018 and 2019 to determine the performance of corn cultivars in different maturity stages. Seven varieties of corn (Everest, Aga, Kilowatt, Burak, Samada-07, P30B74 and P31Y43) were harvested at 3 different growth stages (silking, end of milk and dough stages) to determine the changes in some parameters of growing, forage quantity and quality. The highest average of dry forage yield (24159 kg ha-1 average of years) was determined at the third harvest date. The maximum cob rate was also measured at the third harvest date, but the maximum leaf and stalk rates were measured at the first harvest date. The average protein rate decreased throughout the growing period while ADF and NDF increased. Almost all of the varieties were found to have large leaf areas. The Burak variety came to the fore due to its long length and relatively thick stalk features and high green and dry yields. Moreover, P31Y43 was determined to have a high quality in addition to high green and dry grass yields. Therefore, the Burak and P31Y43 can be suggested in terms of high parameters both quantity and quality under different crop conditions for increase production.</jats:p