Rapid analysis of DNA methylation using new restriction enzyme sites created by bisulfite modification.

Bisulfite converts non-methylated cytosine in DNA to uracil leaving 5-methylcytosine unaltered. Here, predicted changes in restriction enzyme sites following reaction of genomic DNA with bisulfite and amplification of the product by the polymerase chain reaction (PCR) were used to assess the methylation of CpG sites. This procedure differs from conventional DNA methylation analysis by methylation-sensitive restriction enzymes because it does not rely on an absence of cleavage to detect methylated sites, the two strands of DNA produce different restriction enzyme sites and may be differentially analyzed, and closely related sequences may be separately analyzed by using specific PCR primers.     

Ultrastructural localization of carbohydrates in Reichert's membrane of the mouse

In the present investigation, we examined the role of trophoblast and parietal endoderm cells in the synthesis of carbohydrate-containing components of Reichert's membrane. To eliminate the function of Reichert's membrane as a filter between maternal and embryonal tissues we carried out our examination under in vitro conditions. Parietal yolk sac from mouse embryos on day 9 post coitum (p.c.) were cultivated for 0 to 5 days. Because tannic acid enables a complex formation between carbohydrates and osmium we chose the fixation with this acid for the ultrastructural study. Electron microscopy showed that for assembly of Reichert's membrane, trophoblast cells produce and then release components that were detected as tannic acid-positive granules both in the Reichert's membrane and in the vacuoles of the trophoblast cells. To localize specific carbohydrates we used postembedding-gold-lectin histochemistry on LR-Gold^R-embedded tissues. Strong binding sites for the lectins WGA (Triticum vulgare), RCA I (Ricinus communis) and Con A (Canavalia ensiformis) were observed in Reichert's membrane and trophoblast cells but not in the parietal endoderm cells. The LTA (Lotus tetragonolobus)-binding pattern was positive in the membrane and its adjacent cells but that of the LFA (Limax flavus) was negative in the parietal endoderm cells and very weak in Reichert's membrane and trophoblast cells. Our results demonstrate that trophoblast cells are involved in the construction of Reichert's membrane through the production and release of specific glycoconjugates.     

Identification of an Immunoglobulin M (IgM) Antibody Against Enolase 1 Protein (ENO1) Derived from HEK-293 Cells in Patients with Kidney Failure

Kidney failure is one of the most important challenges in medicine. In this study, we used HEK-293 kidney cells to evaluate and compare changes in the expr     

Structure-activity study of phosphoramido acid esters as acetylcholinesterasf inhibitors

Phosphoramido acid esters (CH₃)₂NP(O)X(p-OC₆H₄-CH₃) (containing P-Cl (1), P-O (2), P-F (3), P-CN (5), and P-N (4,6) bonds, X for 2, 4 and 6 is OCH₃, (C₂H₅)₂N and morpholin) have been synthesized to investigate the structure-activity study of AChE enzyme inhibition, through the parameters logP, δ³¹P and IC₅₀. After their characterization by ³¹P, ³¹P{¹H}, ¹³C, ¹H NMR, IR and mass spectroscopy, the parameters logP and δ³¹P (³¹P chemical shift in NMR) were used to evaluated the lipophilicity and electronical properties. The ability of compounds to inhibit human AChE was predicted by PASS software (version 1.193), and experimentally evaluated by a modified Ellman's assay.     

Effects of Refractive Index Variations on the Optical Transmittance Spectral Properties of the Nano-Hole Arrays

The 3D finite difference time domain technique was carried out to study the optical transmission properties of nano-hole arrays in the gold thin film supported by materials with different index of refraction in the visible and infrared regions. A series of perforated nano-hole structures on the gold film at different hole radius, hole depth of 100 nm, and structural periodicity of 400 nm were studied. It was found that transmission properties (i.e., intensity, FWHM, and resonance position) were strongly affected by hole radius and surrounding medium index of refraction. The maximum optical transmittance was observed as 31.9 % in a nano-hole array of hole radius of 125 nm and refractive index of 1.3. The maximum sensitivity of 300 nm/RIU was obtained at index of refraction of 1.7, whereas the minimum one was calculated as 110 nm/RIU in a nano-hole array of hole radius of 50 nm. It was also found that on increasing the hole radius from 50 to 125 nm, the spectral sensitivity was decreased, whereas the index sensitivity was increased on increasing the refractive index.