A Nanocapsule Based on Natural Mineral Clinoptilolite Surrounded by a Lecithin Envelope

Biophysics - A technology for obtaining nanoparticles of natural clinoptilolite, a mineral from the zeolite family, under laboratory conditions has been developed. The size of zeolite particles was...     

Cyto B dependent and ouabain insensitive Regulatory Volume Decrease in bicellular mouse embryo

Mouse single-cell embryos exhibit robust Regulatory Volume Decrease (RVD). In what manner the very early mammalian embryo following zygote stage is appreciably altered by the anisotonic extracellular solution is, as yet, totally unclear. Little attention was paid to this direction since there was no way to determine the blastomere volume. This work has served to quantitatively investigate the osmotic response of bicellular mouse embryos employing Laser Scanning Microtomography (LSM) followed with three-dimensional reconstruction (3 DR). We have shown that bicellular mouse embryos in hypotonic Dulbecco’s experience RVD. Embryonic cells subjected to hyposmolar exhibit rapid osmotic swelling followed by gradual shrinking back toward their original volume. The van’ t Hoff law defines swelling phase with the effective hydraulic conductivity of 0.3 micron · min⁻¹ · atm⁻¹. Water release during RVD in bicellular mouse embryos is abolished by Cytochalasin B (Cyto B) and the volume recovery is insensitive to ouabain treatment.     

Ultracytochemical localization and microprobe quantitation of calcium stores in the insect oocyte

Detection of calcium in the follicles of Galleria mellonella (Lepidoptera) was performed using two cytochemical methods. Calcium precipitation was obtained either with ammonium oxalate (AO) or with N,N-naphtaloylhydroxylamine (NHA). In both cases the X-ray "on line" analysis monitored the presence of calcium in the oocytes, which was correlated with the accumulation of yolk spheres. Concentration of calcium in oocytes filled with yolk and treated with AO amounted to 9 mmoles per 1,000 g tissue wet weight. This value is similar to that calculated previously for follicles untreated with any reagent and prepared for the analysis by the freeze-drying technique (Prze?ecka et al. 1980). Examination of the ultrastructure of oocytes treated with NHA revealed calcium precipitate at the follicular epithelium/oocyte interface, in endocytotic canaliculi and vesicles formed by the oocyte plasma membrane, in ooplasm, and in yolk spheres. In oocytes treated with AO, the calcium-precipitate intermingled with the precipitate produced by the osmium alone. The presumed cause of this phenomenon is discussed.     

Phosphorylation and biosynthesis of high molecular weight proteins of tumor nuclear matrix

INTRODUCTIONAsearlyasin1948wehavefr8CtionatedisolatednucleifromnormalandtumorcellsbyextractionwithiMNaCIanddilutealkali[1].Thenuclearresiduewasthenstudiedmorethoroughly[2,3].Lateron,sillillarproteinousnuclearresidueswereisolatedbyotherworkers[46]andasstud…     

Algorithms and software for support of gene identification experiments

MOTIVATION: Gene annotation is the final goal of gene prediction algorithms. However, these algorithms frequently make mistakes and therefore the use of gene predictions for sequence annotation is hardly possible. As a result, biologists are forced to conduct time-consuming gene identification experiments by designing appropriate PCR primers to test cDNA libraries or applying RT-PCR, exon trapping/amplification, or other techniques. This process frequently amounts to 'guessing' PCR primers on top of unreliable gene predictions and frequently leads to wasting of experimental efforts. RESULTS: The present paper proposes a simple and reliable algorithm for experimental gene identification which bypasses the unreliable gene prediction step. Studies of the performance of the algorithm on a sample of human genes indicate that an experimental protocol based on the algorithm's predictions achieves an accurate gene identification with relatively few PCR primers. Predictions of PCR primers may be used for exon amplification in preliminary mutation analysis during an attempt to identify a gene responsible for a disease. We propose a simple approach to find a short region from a genomic sequence that with high probability overlaps with some exon of the gene. The algorithm is enhanced to find one or more segments that are probably contained in the translated region of the gene and can be used as PCR primers to select appropriate clones in cDNA libraries by selective amplification. The algorithm is further extended to locate a set of PCR primers that uniformly cover all translated regions and can be used for RT-PCR and further sequencing of (unknown) mRNA.