Delivery and processing of exogenous double-stranded DNA in mouse CD34 + hematopoietic progenitor cells and their cell cycle changes upon combined treatment with cyclophosphamide and double-stranded DNA

We previously reported that fragments of exogenous double-stranded DNA can be internalized by mouse bone marrow cells without any transfection. Our present analysis shows that only 2% of bone marrow cells take up the fragments of extracellular exogenous DNA. Of these, ~ 45% of the cells correspond to CD34 + hematopoietic stem cells. Taking into account that CD34 + stem cells constituted 2.5% of the total cell population in the bone marrow samples analyzed, these data indicate that as much as 40% of CD34 + cells readily internalize fragments of extracellular exogenous DNA. This suggests that internalization of fragmented dsDNA is a general feature of poorly differentiated cells, in particular CD34 + bone marrow cells.     

The study of markers of herpes virus infections in myocardial ischemia

A group of patients with ischemic heart disease (IHD), who underwent surgical aorta-coronary vascular shunting, was examined in this investigation. Low titers of HSV-1 specific IgG were detected in all patients, the obtained values being consistent with similar data obtained in healthy subjects of the same age. Negative PCR of HSV-I DNA in blood and biopsy results were obtained. None of the patients demonstrated typical clinical pattern of infectious disease caused by herpes simplex virus. These data are evidence of the absence of the HSV-1 correlation with coronary atherosclerosis in patients with the IHD diagnosis. The significance of HCMV specific IgG titers and HCMV DNA detected in blood plasma in 87.7% cases is probably attributed to existence of connection of HCMV infection markers revealing in patient' blood with IHD diagnosis and coronary atherosclerosis. Besides, the HCMV DNA presence in biopsy taken from myocardium or vascular wall with lesion is revealed in 100% cases. The cytomegalovirus markers in tissue lesions with the help of specific antiserums marked to HSMV recombinant proteins are also revealed in 100% cases. This fact indicates the connection between pathological atherosclerotical process in IHD and cytomegalovirus infection.     

Prediction of the three-dimensional structure of aflatoxin of Aspergillus flavus by homology modelling

Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus spp. The toxic effects of aflatoxins have adverse consequences for human health and agricultural economics. The aflR gene, a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. AFLR-Protein three-dimensional model was generated using Robetta server. The modeled AFLR-Protein was further optimization and validation using Rampage. In the simulations, we monitored the backbone atoms and the C-α-helix of the modeled protein. The low RMSD and the simulation time indicate that, as expected, the 3D structural model of AFLR-protein represents a stable folding conformation. This study paves the way for generating computer molecular models for proteins whose crystal structures are not available and which would aid in detailed molecular mechanism of inhibition of aflatoxin.     

Mapping the amino acid properties of constituent nucleoporins onto the yeast nuclear pore complex

Visualization of molecular structures aids in the understanding of structural and functional roles of biological macromolecules. Macromolecular transport between the cell nucleus and cytoplasm is facilitated by the nuclear pore complex (NPC). The ring structure of the NPC is large and contains several distinct proteins (nucleoporins) which function as a selective gate for the passage of certain molecules into and out of the nucleus. In this note we demonstrate the utility of a python code that allows direct mapping of the physiochemical properties of the constituent nucleoporins on the scaffold of the yeast NPC׳s cytoplasmic view. We expect this tool to be useful for researchers to visualize the NPC based on their physiochemical properties and how it alters when specific mutations are introduced in one or more of the nucleoporins. The code developed using Python is available freely from the authors.     

"Delayed death" phenomenon: a synergistic action of cyclophosphamide and exogenous DNA

Morbidity and mortality in mice were observed upon administration of exogenous DNA following their pre-treatment with a cytostatic agent cyclophosphamide. Upon intraperitoneal injections, the fragments of exogenous DNA reached bone marrow cells. These cells were also found to internalize up to 1800 kb of exogenous DNA ex vivo. The 18-24 h time frame represents a final stage in the repair of DNA double-strand breaks, so when exogenous DNA was administered within this critical period of time, pathological changes were observed in many target organs. Namely, bone marrow cells underwent a sustained increase in apoptosis. Copy number of B1 and B2 DNA repeats in bone marrow cells remained unchanged, whereas in the control group of animals their levels were significantly decreased. Finally, the bone marrow cells of moribund animals completely lacked lymphoid progenitors, yet the CD34+ hematopoietic stem cell counts were normal. Histopathology analysis suggested that mice died due to accidental involution of lymphoid organs combined with a systemic inflammatory process induced by massive administration of exogenous DNA and depletion of lymphoid lineage.     

The treatment of isolated genera

Problems presented by genera, or small groups of genera, which have been given family rank are reviewed, and the genera are divided into a number of categories according to the closeness of their affinity to other genera or families. Satellite genera that stand in close relation to families should be united with them. Binary families, that have been divided into two (or more) related families, should be re–united. Families connected by linking genera, should, logically, be united but practical considerations usually prevent this. Clusters of diverse but more or less distantly related genera present unusual problems, being treated either as several, often monogeneric families or as a loosely structured family. Truly isolated genera must be given family and often ordinal rank.     

Ultrastructural and radioautographic research on the skin in acantholysis bullosa

By means of light microscopy 145 biopsies of skin in acantholytic pemphigus were studied. Electron microscopic and radioautographic study was carried out in 19 cases. It was determined that the whole complex of ultrastructural changes in epidermocytes (impairment of nucleolar apparatus, lysis of cytoplasmic organelles, disappearance of desmosomes) reflects the disturbance of protein synthesis. Radioautographic study in vitro with 3H-uridine and 3H-thymidine revealed the low level of RNA and DNA synthesis in epidermal cells in pemphigus. The data obtained were interpreted with a position from the conception of plastic deficiency.