Polysaccharide derivatives as coats for nylon tube urease

Urease was immobilized on O-alkylated nylon tubes coated with polyaminated derivatives of starch or dextran. The specific activity of the enzyme coil and the relative stability of the immobilized enzyme, compared with immobilized urease derived from other nylon tube modifications, were enhanced. Also, the nonspecific binding of urease to O-alkylated nylon tubes was virtually eliminated by the coating process.     

Effects of taxol on endothelial cells of the developing semilunar heart valves in the chick embryo

Recent ultrastructural studies have revealed that there are differences in endothelial cell shape and cytoskeletal architecture between the arterial and ventricular faces of developing semilunar valves. In the present work we have analyzed valvular endothelial cell response to taxol in the chick embryo. Following taxol administration, abnormal mitotic cells appear in the endothelium of both faces of the cusps. Interphase cells show few structural alterations. No differential response of the valvular endothelium to the drug was observed in the arterial or ventricular faces of the cusps.     

Unidirectional hybridization of kaluga <Emphasis Type="Italic">Acipenser dauricus</Emphasis> Georgi, 1775 and Amur sturgeon <Emphasis Type="Italic">Acipenser schrenckii</Emphasis> Brandt, 1869, inferred from the mitochondrial DNA genotyping of their natural hybrids

In 2009 through 2011, among 730 individuals of kaluga and Amur sturgeon collected in the lower reaches of the Amur River and the Amursky Liman, 17 morphologically intermediate individuals (hybrids) with the body length of 56 to 202 cm (median, 81 cm) were identified, including 11 individuals (4.6%) found in 2009, three individuals (1.6%) found in 2010, and three individuals (1.1%), in 2011. In 16 hybrids, 819 bp of the mtDNA control regions were sequences and 11 haplotypes were identified. Since all these haplotypes were from the mtDNA lineages of kaluga, it was concluded that hybridization occurred in one direction, kaluga (♀) × Amur sturgeon (♂). This asymmetry could be caused by the large size differences between these species. Since the earlier examined morphologically typical Amur sturgeons showed the absence of alien haplotypes (Shedko et al., 2015), the absence of the mtDNA introgression is claimed. This can be caused by low viability or sterility of the backcross females (kaluga (♀) × Amur sturgeon (♂)) × Amur sturgeon (♂). The samples of hybrids and typical kaluga individuals demonstrated no differences in the frequency spectra of the mtDNA haplotypes. However, haplotype and nucleotide diversity in the first sample was somewhat higher than in the second one (0.950 versus 0.927 and 0.0054 versus 0.0044, respectively). The data obtained will be useful for population monitoring of kaluga and Amur sturgeon, Amur River endemics, which are classified as critically endangered by the IUCN Red List of Threatened Species.     

A morphometric comparison of subcellular structures between primary breast tumors and their nodal metastases.

A morphometric study of subcellular structures in human primary breast tumors (of the ductal infiltrating type) and their synchronous lymph node metastases was carried out using planimetry and stereology. Each primary neoplasm was compared separately with its axillary metastatic growth in order to detect differences in the quantitative estimates of their subcellular components. A set of 24 morphometric parameters was used to quantitatively describe each neoplastic cell profile. Although some subcellular parameters showed significant differences between the cells of a primary tumor and its metastases, no parameter was found to be consistently altered in all cases. No consistent increase or decrease in the values of the affected parameters was observed in the metastases. More than being due to the expression of a biologically variant (more-or-less differentiated) metastatic phenotype, the differences in stereologic parameters detected in metastatic cells appear to reflect the existence of different functional states of the same cell type.