Synthesis of naphthalimide derivatives with potential anticancer activity,their comparative ds- and G-quadruplex-DNA binding studies and related biological activities

Molecular Biology Reports - Two new cytotoxic 1,8-naphthalimide derivatives have been synthesized and characterized. Their biological activities as cytotoxicity and antimicrobial activities and...     

Identification of O-acetylserine(thiol)lyase (OASTL) genes in sorghum (Sorghum bicolor) and gene expression analysis under cadmium stress

Cysteine (Cys) is the first identified molecule in plant metabolism which includes both sulfur and nitrogen. It can be synthesized in three cellular compartments, containing chloroplast, cytoplasm and mitochondrion. The final step of cysteine biosynthesis is catalyzed by the O-acetylserine(thiol)lyase enzyme (OASTL, E.C. 4.2.99). In the present study, seven members of the OASTL gene family in the sorghum (Sorghum bicolor) genome were identified at a genome-wide scale and comparative bioinformatics analyses were performed between sorghum and Arabidopsis OASTLs. In all OASTL proteins, a pyridoxal-phosphate dependent domain structure (PALP, PF00291) was identified. The gene ontology annotations also revealed that all sorghum OASTL genes have KOG1252 (Cystathionine beta-synthase and related enzyme) and K01738 (cysteine synthase A) activities. In promotor sequences of OASTL genes, diverse cis-acting elements were found, including hormone and light responsiveness, abiotic stress responsiveness, and tissue-specific ones (meristem and endosperm). Sorghum OASTL genes demonstrated medium or high level expressions in anatomical parts and developmental stages based on the digital expression data. Expression of OASTL genes were also analyzed under cadmium (Cd) stress in sorghum by Real Time-quantitative PCR (RT-qPCR). The results exclusively showed that OASTL A1-2 gene was 1.12 fold up-regulated in roots, whereas cysteine synthase 26 was 2.25 fold down-regulated in leaves. The predicted 3D structure of OASTLs indicated some structural diversities as well as variations in the secondary structures.

     

Immobilization of tyrosinase in polysiloxane/polypyrrole copolymer matrices

Immobilization of tyrosinase in conducting copolymer matrices of pyrrole functionalized polydimethylsiloxane/polypyrrole (PDMS/PPy) was achieved by electrochemical polymerization. The polysiloxane/polypyrrole/tyrosinase electrode was constructed by the entrapment of enzyme in conducting matrices during electrochemical copolymerization. Maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) were investigated for immobilized enzyme. Enzyme electrodes were prepared in two different electrolyte/solvent systems. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate on the enzyme activity and film morphology were determined. Temperature and pH optimization, operational stability and shelf-life of enzyme electrodes were also examined. Phenolic contents of green and black tea were determined by using enzyme electrodes.     

Determination of half-maximal inhibitory concentration using biosensor-based protein interaction analysis

Half-maximal inhibitory concentration (IC₅₀) is the most widely used and informative measure of a drug's efficacy. It indicates how much drug is needed to inhibit a biological process by half, thus providing a measure of potency of an antagonist drug in pharmacological research. Most approaches to determine IC₅₀ of a pharmacological compound are based on assays that utilize whole cell systems. While they generally provide outstanding potency information, results can depend on the experimental cell line used and may not differentiate a compound's ability to inhibit specific interactions. Here we show using the secreted Transforming Growth Factor-β (TGF-β) family ligand BMP-4 and its receptors as example that surface plasmon resonance can be used to accurately determine IC₅₀ values of individual ligand-receptor pairings. The molecular resolution achievable wih this approach can help distinguish inhibitors that specifically target individual complexes, or that can inhibit multiple functional interactions at the same time.     

Immobilization of polyphenol oxidase in conducting copolymers and determination of phenolic compounds in wines with enzyme electrodes

Polyphenol oxidase (PPO) was immobilized in copolymers of thiophene functionalized menthyl monomer (MM) with pyrrole. Immobilization of enzyme was performed via entrapment in conducting copolymers during electrochemical polymerization of pyrrole. Maximum reaction rates, Michaelis-Menten constants and temperature, pH and operational stabilities of enzyme electrodes were investigated. Total amount of phenolic compounds in red wines of Turkey were analyzed by using these electrodes.     

A case of biliary Fascioliasis by Fasciola gigantica in Turkey

A case of Fasciola gigantica-induced biliary obstruction and cholestasis is reported in Turkey. The patient was a 37- year-old woman, and suffered from icterus, ascites, and pain in her right upper abdominal region. A total of 7 living adult flukes were recovered during endoscopic retrograde cholangiopancreatography (ERCP). A single dose of triclabendazole was administered to treat possible remaining worms. She was living in a village of southeast of Anatolia region and had sheeps and cows. She had the history of eating lettuce, mallow, dill, and parsley without washing. This is the first case of fascioliasis which was treated via endoscopic biliary extraction during ERCP in Turkey.     

Immobilization of glucose oxidase in conducting graft copolymers and determination of glucose amount in orange juices with enzyme electrodes

Glucose oxidase was immobilized in conducting copolymers of three different types of poly(methyl methacrylate-co-thienyl methacrylate). Immobilization of enzyme was carried out by the entrapment in conducting polymers during electrochemical polymerization of pyrrole on the copolymer electrodes. Maximum reaction rate, Michaelis-Menten constants, temperature, pH and operational stabilities were determined for immobilized enzyme. The amount of glucose in orange juices of Turkey was investigated by using enzyme electrodes.     

Clinical significance of serum leptin level in patients with gastric cancer

Leptin may support the proliferation and hinder the apoptosis of tumor cells. Although leptin expression has been studied in several human tumors, its potential clinical significance remains uncertain in patients with gastric carcinoma. Furthermore, the majority of available findings have been determined from preclinical studies using stomach carcinoma tissue section and, to date, few studies have evaluated the clinical significance of leptin in the serum or plasma of gastric carcinoma patients. In the current study, the serum concentration of soluble leptin was assessed in gastric carcinoma patients, and its contributions to the clinical parameters and prognosis of patients were determined. A total of 63 pathologically confirmed gastric cancer patients and 30 healthy subjects were enrolled in the study and circulating leptin levels in the serum of all subjects were determined by ELISA. The serum leptin concentrations were significantly lower in the gastric cancer patients compared with the healthy control group (P = 0.009). In the gastric cancer patients, the clinical features of patient age, sex, lesion localization, histopathology, pathological grade, stage of disease, and serum tumor markers including lactate dehydrogenase, carcinoembryonic antigen, and carbohydrate antigen 19–9 were not correlated with serum leptin concentration. Furthermore, no association was observed between serum leptin concentration and responsiveness to chemotherapy (P = 0.51), and leptin level had no apparent prognostic role in clinical outcome (P = 0.57). In conclusion, although it was not predictive or prognostic, serum leptin level may be a valuable diagnostic indicator in patients with gastric carcinoma.     

Antidepressant drugs act by directly binding to TRKB neurotrophin receptors

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