Mitochondrial DNA haplogrouping of the brown bear,Ursus arctos (Carnivora: Ursidae) in Asia,based on a newly developed APLP analysis

Sequence analyses of the complete brown bear, Ursus arctos, mitochondrial DNA (mtDNA) genome have detected scattered single nucleotide polymorphisms (SNPs) that define distinct mtDNA haplogroups in phylogeographical studies. The degraded DNA in historical samples, such as stuffed or excavated specimens, however, is often not suitable for sequence analyses. To address this problem, we developed an amplified product length polymorphism (APLP) analysis for mtDNA‐haplogrouping U. arctos specimens by detecting haplogroup‐specific SNPs. We verified the validity and utility of this method by analysing up to 170‐year‐old skin samples from U. arctos specimens collected widely across continental Eurasia. We detected some of the same haplogroups as those occurring in eastern Hokkaido (Japan) and eastern Alaska in continental Eurasia (the Altai and the Caucasus). Our results show that U. arctos in eastern Hokkaido and eastern Alaska descended from a common ancestor in continental Eurasia, and suggest that U. arctos occupied several refugia in southern Asia during the Last Glacial Maximum. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 627–635.     

Nucleus-independent chemical shift criterion for aromaticity in π-extended tetraoxa[8]circulenes

Recently synthesized π-extended symmetrical tetraoxa[8]circulenes that exhibit electroluminescent properties were calculated at the density functional theory (DFT) level using the quantum theory of atoms in molecules (QTAIM) approach to electron density distribution analysis. Nucleus-independent chemical shift (NICS) indices were used to characterize the aromaticity of the studied molecules. The tetraoxa[8]circulene molecules were found to consist of two antiaromatic perimeters (according to the Hückel “4n” antiaromaticity rule) that include 8 and 24 π-electrons. Conversely, NICS calculations demonstrated the existence of a common π-extended system (distributed like a flat ribbon) in the studied tetraoxa[8]circulene molecules. Thus, these symmetrical tetraoxa[8]circulene molecules provide examples of diatropic systems characterized by the presence of induced diatropic ring currents.

Biodeterioration of Mayan buildings at uxmal and tulum,Mexico

Uxmal and Tulum are two important Mayan sites in the Yucatan peninsula. The buildings are mainly composed of limestone and grey/black discoloration is seen on exposed walls and copious greenish biofilms on inner walls. The principal microorganisms detected on interior walls at both Uxmal and Tulum were cyanobacteria; heterotrophic bacteria and filamentous fungi were also present. A dark‐pigmented mitosporic fungus and Bacillus cereus, both isolated from Uxmal, were shown to be acidogenic in laboratory cultures. Cyanobacteria belonging to rock‐degrading genera Synechocystis and Gloeocapsa were identified at both sites. Surface analysis previously showed that calcium ions were present in the biofilms on buildings at Uxmal and Tulum, suggesting the deposition of biosolubilized stone. Apart from their potential to degrade the substrate, the coccoid cyanobacteria supply organic nutrients for bacteria and fungi, which can produce organic acids, further increasing stone degradation.     

DR3/LARD spliced mRNA variants’ frequency in colorectal cancer

Many variants of the DR3/LARD death receptor mRNA are derived during alternative splicing. Different DR3/LARD mRNAs encode the membrane and soluble forms of the receptor, which perform different functions. The frequency of the spliced mRNA variants of DR3/LARD was assessed by RT-PCR in patients with colorectal cancer and in cancer cell lines. Four forms of the DR3/LARD death receptor mRNA were detected with different frequencies in the studied samples. Two of them encoded the membrane molecules (LARD 1a mRNA and DR3β mRNA) and two other forms expressed the soluble forms of the receptor (LARD 3 mRNA and soluble DR3β mRNA). In the blood of healthy volunteers, 11 variants (spectra) of DR3/LARD mRNA forms were identified, and the full spectrum that included all four variants of DR3/LARD mRNA dominated. In blood and tumor center samples from patients with colon cancer, six spectra of DR3/LARD mRNA were found. The diversity of the DR3/LARD mRNA spectra was decreased in colon cancer patients due to the reduced frequency of soluble DR3β mRNA. In samples of tumor centers, the spectrum with the absence of only mRNA of the soluble DR3β form dominated. In the blood of patients, two spectra prevailed, i.e., the full spectrum and LARD 1a mRNA and LARD 3 mRNA. Only these two spectra of DR3/LARD mRNA were also found in cancer cell lines. Distinctions in the frequency of DR3/LARD mRNA spectra in healthy volunteers and patients with colorectal cancer can define the different susceptibility of immunocompetent and tumor cells to apoptosis signals.     

Endothelial dysfunction in the development of vascular complications in diabetes mellitus

Patients with type 1 diabetes, aged 18 to 42 years, were compared to those aged 11 to 22 years. Activities of endothelial vasoactive factors and endothelial and leukocyte adhesion molecules were studied at different stages of development diabetes complications: nephropathy and retinopathy. The findings reveal role of the vasoactive factors in microangiopathy course.     

Energy distribution and ionic selectivity of the bacterial potassium channel

An explanation for the ionic selectivity of the bacterial potassium channel K(CS)A is offered, which is based on a comparison of energy interactions of lithium, sodium, and potassium cations with the atoms of the selective filter of an protein pore. Using quantum-chemical calculations, the presence of a deeper potential hole for potassium ions was discovered, which explains the energy preferableness in their permeability. It has been shown that the traditional methods of force field AMBER, CHARMM, OPLS in reference parametrization and also at their partial reparametrization give incorrect ratings of energy distribution of ions in the channel.     

Detection of an antigen, associated with cells during the blast crisis of chronic myeloleukemia, in a cytotoxic test using xenogenic antibodies]

The immune antimyeloblast serum (AMS) was obtained from horses immunized with white blood cells from patients suffering from chronic myeloid leukemia (CML) at the blast crisis stage; the serum was completely absorbed with normal red blood cells and white blood cells (WBC). The absorbed antiserum remained cytotoxic to blast cells from 20 of 42 patients with CML at the blast crisis stage. AMS failed to react with the WBC from patients with CML in its chronic phase, and from patients with other types of leukemia Morphological studies indicated a possibility of identification of the antigen associated with myeloblasts from the blood of patients with CML blast crisis, by means to AMS.     

Modeling of the "universal" bone marrow using monoclonal antibodies

The data on the application of monoclonal antibodies (ICO-10) and rabbit complement for working the conditions of allogeneic bone marrow transplantation are presented in the paper. The treatment with monoclonal antibodies and bone marrow complement from BALB/c mice for 2 times prevented the development of transplant versus host reaction and completely protected lethally irradiated (CBA X X C57B1/6)FI mice-recipients from death. Thymus atrophy and the absence of T-cells in the peripheral blood was observed in these mice. The erythrocytes had markers characteristic of BALB/c and (CBA X C57B1/6)FI mice. Mouse splenocytes did not respond to the cells of donors and recipients in mixed lymphocyte culture reaction.     

Functional activity of ABC transporters (markers of multidrug resistance) in human colon adenocarcinoma and normal colonic mucosa]

Functional activity of multidrug resistance (MDR) markers (total activity of ABC-transporters, P-glycoprotein (Pgp) and multidrug resistance-associated protein (MRP) activities) in human colon adenocarcinoma and normal mucosa was examined. Functional activity of ABC-transporters was revealed in all colon tumors and in 70% of normal mucosa samples investigated. Expression of Pgp and MRP functional activity was determined in about 50% and 70% of colon tumors respectively. Pgp+MRP+ phenotype was determined in 36% of normal mucosa and adenocarcinoma samples. Expression of Pgp+MRP- phenotype was practically the same in normal mucosa and tumors (in 10 and 18% of samples respectively). Pgp-MRP+ phenotype was revealed two times more often in tumors than in mucosa--in 36 and 18% respectively. On the contrary, Pgp-MRP- phenotype was detected more rarely in tumors than in mucosa (in 10 and 36% of samples respectively). Transporters different from Pgp and MRP were also determined in some tumors and normal mucosa. At the patients with expression of Pgp function in normal mucosa the activity of the transporter was revealed in 25% of tumor samples only. On the contrary, at the patients with expression of MRP function in normal mucosa the activity of the transporter was revealed in 70% of tumor samples. At the patients with no expression of Pgp or MRP activity in normal mucosa the function of the transporters in tumors was determined in 60% and 70% of samples respectively. It is concluded that functional activity of various ABC-transporters (Pgp, MRP and other different from Pgp and MRP) is expressed in human colon adenocarcinoma; expression of ABC-transporters functional activity in normal mucosa does not predict MDR phenotype of the tumor.