Lung cancer xenografting alters microRNA profile but not immunophenotype

Lung tumor xenografts grown in immunocompromised mice provide a renewable source of tumor tissue for research and a means to study individualized response to chemotherapy. Critical to this utility is verification that the xenograft cells retain core phenotypic characteristics of the original tumor. We compared eight non-small cell lung carcinomas with their corresponding xenografts grown in mice with severe combined immunodeficiency by way of histology, immunohistochemistry, and microRNA expression profiling. Six of the eight xenografts closely resembled their original tumor by light microscopy. The xenografts also largely retained key immunophenotypic features. With expression profiling of human microRNAs, however, xenografts clustered separately from the original tumors. While this may be partly due to contamination by non-neoplastic human and mouse stroma, the results suggest that miRNA expression may be altered in xenografts and that this possibility should be further evaluated.     

Brefeldin A inhibits expression of DNA packaging proteins and nucleocapsid formation of human cytomegalovirus

In this study we used the fungal antibiotic brefeldin A (BFA) to analyze its effect on viral replication. Analysis by electron microscopy demonstrated that no viral particles were observed in cells treated before the onset of viral replication. In the presence of BFA expression of IE2, MCP, pUL104, pUL56 and pUL89 were reduced, while no or slight effect was observed on expression of pp65, pUL44 and pUL57. Strikingly, real time PCR revealed that de novo viral DNA synthesis is reduced but not completely abolished in the presence of BFA. These results indicated that BFA represents a multi-functional compound leading to inhibition of several steps of viral maturation such as expression of viral DNA packaging proteins and capsid formation.     

Soluble and membrane-associated nitrate reductases in the dinoflagellate Peridinium gatunense

An improved method of cell fractionation allowed the extraction of soluble (sNR) and membrane-associated (mNR) forms of nitrate reductase (NR) from a dinoflagellate, even though in previous studies only mNR had been found in these algae. Both activities were assayed in cell-free extracts of Peridinium gatunense from Lake Kinneret, Israel, after disruption of the cells and differential centrifugation. In the cultures used, sNR showed much higher NO₃⁻-reducing activity. Only a low proportion, 2.5–3% of NR activity, was found to be associated with mNR. Moreover, mNR comprised two forms as indicated by protein solubilization: a tightly membrane-bound and a more weakly attached NR. Ascorbate inhibited all NR activities, but that of mNR recovered after its removal. Polyvinyl pyrrolidone (PVP) and DTT also diminished sNR and mNR activities. For both enzymes, pH optima (7.65) and temperature optima (13–25°C) were similar, and agreed with those for optimum growth of P. gatunense both in culture and in the lake. The most efficient electron donor was NADH, though NADPH sustained low NR activities. Carboxylic anions such as succinate and malate did not support any reduction of NO₃⁻, nor did they cause any stimulation of sNR or mNR activities. Both forms of NR showed a high affinity for their substrates: K _m was c. 10 μM for NO₃⁻ and c. 5 μM for NADH. The high efficiency of NO₃⁻ assimilation by Peridinium seems to be limited mainly by energy under otherwise optimal nutritional conditions and, at low nitrate concentrations, the low K _m may be one of the main reasons for the high competitivity of this alga in Lake Kinneret.     

Classification of videocapsule endoscopy image patterns: comparative analysis between patients with celiac disease and normal individuals

Background  

Quantitative disease markers were developed to assess videocapsule images acquired from celiac disease patients with villous atrophy, and from control patients.     

Osmotic and diffusive properties of intracellular water in camel erythrocytes: effect of hemoglobin crowdedness

Camel erythrocytes have exceptional osmotic resistance and is believed to be due to augmented water-binding associated with the high hydrophilicity of camel hemoglobin. In practical terms this means that the proportion of osmotically non-removable water in camel erythrocytes is nearly 3-fold greater than that in human erythrocytes (approximately 65 vs approximately 20%). The relationship between water diffusion and the osmotic characteristics of intracellular water is the subject of this report. The amount of osmotically inactive water is 2-fold greater in camel hemoglobin solution in vitro compared to that of human, but water diffusion does not differ in camel and human hemoglobin solutions. However, the evaluation of water diffusion by magnetic resonance measurements in camel erythrocytes revealed approximately 15% lower apparent diffusion coefficient (ADC) compared with human erythrocytes. When human erythrocytes were dehydrated to the level of camel erythrocytes, their osmotic and water diffusion properties were similar. These results show that a lower ADC is associated with a more pronounced increase in osmotically inactive water fraction. It is proposed that increased hemoglobin hydrophilicity allows not only augmented water-binding, but also a closer hemoglobin packaging in vivo, which in turn is associated with slower ADC and increased osmotic resistance.     

Paraproteins associated with low plasma sodium levels

The mechanism of the maintenance of low plasma sodium levels seen in certain multiple myeloma cases has been attributed to the cationic nature of pathological immunoglobulins (paraproteins). This hypothesis was tested with equilibrium dialysis and polyacrylamide gel electrophoresis techniques. Citrated plasma samples and affinity chromatography purified paraproteins of three multiple myeloma patients with abnormally low plasma sodium levels were dialysed against 140 mmol/L NaCl solution at pH 7.4 for 24 hours. The electrophoresis of paraproteins was conducted under non-denaturing conditions. Low plasma sodium concentrations observed under the dialysis of the patients' plasma samples were in good agreement with earlier reports. However, the isolated paraproteins did not show any sodium exclusion during the dialysis experiment. The electrophoretic mobility of the paraproteins at pH 7.4 indicated that the isoelectric point of these molecules was below 7.4, so they cannot behave as cations at the pH of the blood. From these data it appears that the maintenance of low plasma sodium levels in certain IgG type myeloma cases cannot be explained by the previously postulated cationic nature of the paraproteins.     

Unique membrane-interacting properties of the immunostimulatory cationic peptide KLKL(5)KLK (KLK)

We have monitored the effects of KLKL(5)KLK (KLK), a derivative of a natural cationic antimicrobial peptide (CAP) on isolated membrane vesicles, and investigated the partition of the peptide within these structures. KLK readily interacted with fluorescent dyes entrapped in the vesicles without apparent pore formation. Fractionation of vesicles revealed KLK predominantly in the membrane. Peptide-treated vesicles appeared with generally disorganized bilayers. While KLK showed no effect on osmotic resistance of human erythrocytes, dramatic decrease in core and surface membrane fluidity was observed in peptide-treated erythrocyte ghosts as measured by fluorescence anisotropy. Finally, CD spectroscopy revealed lipid-induced random coil to beta-sheet and beta-sheet to alpha-helix conformational transitions of KLK. Together with the oligonucleotide oligo-d(IC)(13) [ODN1a], KLK functions as a novel adjuvant, termed IC31. Among other immunological effects, KLK appears to facilitate the uptake and delivery of ODN1a into cellular compartments, but the nature of KLK's interaction with the cell surface and other membrane-bordered compartments remains unknown. Our results suggest a profound membrane interacting property of KLK that might contribute to the immunostimulatory activities of IC31.     

DETECTING DESERTIFICATION PROCESSES USING TM AND ETM+ DATA, NORTH OF ISFAHAN, IRAN

 Aims Desertification results in ecological and biological diminution of the earth, and can happen naturally or cause by anthropogenic activities. This process especially affects arid and semi-arid regions, such as the Isfahan region, where the spread of desertification is reaching critical proportions. The aim of this study is to use remotely sensed data to review the trend of desertification in the northern of Isfahan, Iran. Methods Multi-temporal images were employed to evaluate the trend of desertification, specifically the TM and ETM+ data of September, 1990 and September, 2001. Geometric and radiometric corrections were applied to each image prior to image processing and supervised classification, and vegetation indices were applied to produce a land use map of each image in nine classes. The land use classification s in the two map images were compared and changes between land use classes were detected over the 11 year period using a fuzzy and post-classification technique. Important findings The maps and their comparison with false color composite images showed the differences efficiently. With the fuzzy and post-classification method the land use changes were sited on the map. Fuzzy confirmed 53% changed area and 47% unchanged areas in the study region. The results verify the desertification expansion in the study areas. Because of poor land management, agricultural lands converted to desert and abandoned areas, and some marginal pasture lands had to be changed to agricultural land which are desertification spreading according to United Nations Conference on Desertification (UNCOD). Also farmland and pastures have been converted to urban and industrial areas, and the rangelands have been spoiled due to opencast mine excavations. With the mine margins eroding as well as their debris accumulating on the pasture lands, desertification has become worse. Three areas of less-elevated mountains have remained unchanged. This study confirmed that the anthropogenic activities accelerated the desertification process and severely endangered the remaining areas.