Induction of insulin release in fibroblasts transfected with genomic rat islet DNA

L cells (tk-) were cotransfected with total genomic rat islet DNA and a plasmid containing thymidine kinase gene (ptk). Transfectants were tested for their ability to release insulin into the medium. At least 10% of the colonies contained immunoreactive insulin (IRI) during the initial two weeks. The insulin secreted competed linearly with rat insulin in RIA, the majority of the insulin antigenicity comigrating with rat insulin on G-50 Sephadex chromatography. With continuing propagation the IRI activity diminished; however 3 selected cultures demonstrated increased secretion of IRI following stimulation with glucose. These findings indicate that glucose-induced insulin secretion can be obtained in non-beta cells; however the frequency of success was below one stable transfection for every 5 X 10(8) Ltk- cells exposed to the transfection procedure.     

Is the alpha rhythm a control parameter for brain responses?

 The main goal of the present study is to develop a conceptual analysis of alpha response in the brain based on single sweep evaluation. A new method was employed to estimate a set of single-sweep parameters and quantify the oscillatory behaviour of single, electroencephalograph (EEG) sweeps. It was aimed to demonstrate that brain alpha responses are governed by spontaneous alpha activity and to validate the principle of brain response excitability. Because the spontaneous alpha activity depends on both the topology of recording and the subject’s age, topology and age models were used. Spontaneous and evoked alpha activity were recorded at frontal and occipital sites in three groups of subjects: 3-year-old children, young adults and middle-aged subjects. Amplitude, enhancement and phase-locking of single alpha responses to visual stimuli were analysed. Major results showed that: (1) visual alpha responses could be recorded only if the alpha rhythm was developed in the spontaneous EEG independent of electrode location; (2) middle-aged adults showed more expressed frontal spontaneous alpha activity in comparison with young adults; (3) accordingly, alpha responses with higher amplitude and stronger phase-locking were produced over the frontal brain area in middleaged than young adults. These results validate the principle of brain response excitability and demonstrate that a shift towards frontal brain areas for both the spontaneous and evoked alpha activity occurs with increasing age in adults. The results are discussed in the context of the diffuse and distributed alpha system of the brain. Age-dependent changes in frontal alpha activity are suggested to be related to frontal brain functioning during aging. Received: 6 November 1995 / Accepted in revised form: 13 March 1997     

Quantification of Phenolic Component by LC-HESI-MS/MS and Evaluation of Antioxidant Activities of Crocus Ancyrensis (Ankara Çiğdemi) Extracts Obtained with Different Solvents

In this study, Crocus ancyrensis was extracted from different parts of the plants with various solvents and their antioxidant activities and phenolic contents were investigated in detail for the first time. The highest amount of total phenolic substance in all parts of the plant was determined in the stigmaless flower. In the DPPH and FRAP methods, the highest antioxidant activity was obtained from the water extraction from the plant. Rutin is the highest detected by LC MS/MS. Stigmaless flower extract in all solvents is attributed to the component that contributes the most to antioxidant capacity. p-hydroxy benzoic acid was detected as the highest phenolic component after rutin. When the antioxidant activity results were examined, it was determined that the highest activity was in the water extract. As a result, it is evaluated that rutin and p-hydroxybenzoic acid in the plant contribute to the antioxidant capacity.     

Mosquito Saliva Serine Protease Enhances Dissemination of Dengue Virus into the Mammalian Host

Dengue virus (DENV), a flavivirus of global importance, is transmitted to humans by mosquitoes. In this study, we developed in vitro and in vivo models of saliva-mediated enhancement of DENV infectivity. Serine protease activity in Aedes aegypti saliva augmented virus infectivity in vitro by proteolyzing extracellular matrix proteins, thereby increasing viral attachment to heparan sulfate proteoglycans and inducing cell migration. A serine protease inhibitor reduced saliva-mediated enhancement of DENV in vitro and in vivo, marked by a 100-fold reduction in DENV load in murine lymph nodes. A saliva-mediated infectivity enhancement screen of fractionated salivary gland extracts identified serine protease CLIPA3 as a putative cofactor, and short interfering RNA knockdown of CLIPA3 in mosquitoes demonstrated its role in influencing DENV infectivity. Molecules in mosquito saliva that facilitate viral infectivity in the vertebrate host provide novel targets that may aid in the prevention of disease.     

A Case of Budd-Chiari Syndrome Associated with Alveolar Echinococcosis

Although alveolar echinococcosis (AE) can cause a serious disease with high mortality and morbidity similar to malign neoplasms. A 62-year-old woman admitted to a hospital located in Sivas, Turkey, with the complaints of fatigue and right upper abdominal pain. On contrast abdominal CT, a 54×70×45 mm sized cystic lesion was detected in the left lobe of the liver that was seen to extend to the posterior mediastinum and invade the diaphragm, esophagus, and pericardium. The cystic lesion was seen to be occluding the inferior vena cava and left hepatic vein at the level where the hepatic veins poured into the inferior vena cava. Bilateral pleural effusion was also detected. We discussed this secondary Budd-Chiari Syndrome (BCS) case, resulting from the AE occlusion of the left hepatic vein and inferior vena cava, in light of the information in literature.