Identification of newly isolated Babesia parasites from cattle in Korea by using the Bo-RBC-SCID mice

Attempts were made to isolate and identify Korean bovine Babesia parasite. Blood samples were collected from Holstein cows in Korea, and Babesia parasites were propagated in SCID mice with circulating bovine red blood cells for isolation. The isolate was then antigenically and genotypically compared with several Japanese isolates. The Korean parasite was found to be nearly identical to the Oshima strain isolated from Japanese cattle, which was recently designated as Babesia ovata oshimensis n. var. Haemaphysalis longicornis was the most probable tick species that transmitted the parasite.     

Proteome analysis of conditioned medium from mouse embryonic fibroblast feeder layers which support the growth of human embryonic stem cells

Human embryonic stem (ES) cells are pluripotent cells with the potential to differentiate into a variety of cell types, which could be used for cell transplantation therapies as well as drug discovery studies. However, the large-scale culture of undifferentiated human ES cells is currently limited by their dependency on mouse embryonic fibroblast feeder layers. The proteomics approach was employed to characterize the environment that supports the growth of undifferentiated human ES cells and to identify factors critical for their independent growth. Conditioned medium from mouse embryonic fibroblast feeder layers, STO cell line, was concentrated and subjected to analyses by two-dimensional electrophoresis mass spectrometry. In total, 136 unique protein species were identified which included some that are known to participate in cell growth and differentiation, extracellular matrix formation and remodeling, in addition to the unexpected but interesting finding of many nominally intracellular proteins. This approach has thus revealed the complexity of the environment provided by the feeder cells and provides a useful starting point for future studies. Moreover, candidates from the initial list of identified proteins can be further investigated for their effects on the growth and differentiation of human ES cells in a defined culture environment.     

Intestinal candidiasis. A clinical report and comments about this opportunistic pathology

An eight-years-old girl, who presented with recurrent upper respiratory tract infections, was treated with broad-spectrum antibiotics. Afterward she presented with intestinal candidiasis. The isolated species was identified as Candida albicans by differential tests. Treatment given was with 500,000 IU of oral nystatin every 8 hours for 10 days and intestinal normal microbiota restoratives. Evolution has been satisfactory, although concomitantly type A hepatitis developed. Rest and a soft diet were recommended. The child is now perfectly healthy with normal liver function tests. CONCLUSION: Prolonged treatments with broad-spectrum antibiotics destroyed the indigenous intestinal microbiota, which provoked intestinal C. Albicans proliferation and adversely affected the immunological system of the patient, thus facilitating the establishment of a viral infection.     

The COP9 signalosome: an assembly and maintenance platform for cullin ubiquitin ligases?

The COP9 signalosome (CSN) is a highly conserved protein complex implicated in diverse biological functions that involve ubiquitin-mediated proteolysis. Paradoxically, conserved enzymatic activities associated with CSN inhibit cullin ubiquitin ligase activity in vitro, whereas mutational analysis suggests that CSN promotes cullin-dependent proteolysis in vivo. This apparent paradox can be resolved in a model that proposes CSN-mediated cullin inhibition is a prerequisite for the proper assembly and maintenance of active cullin ubiquitin ligase complexes.     

Maternal diabetes induces congenital heart defects in mice by altering the expression of genes involved in cardiovascular development

Background

Congenital heart defects are frequently observed in infants of diabetic mothers, but the molecular basis of the defects remains obscure. Thus, the present study was performed to gain some insights into the molecular pathogenesis of maternal diabetes-induced congenital heart defects in mice.

Methods and results

We analyzed the morphological changes, the expression pattern of some genes, the proliferation index and apoptosis in developing heart of embryos at E13.5 from streptozotocin-induced diabetic mice. Morphological analysis has shown the persistent truncus arteriosus combined with a ventricular septal defect in embryos of diabetic mice. Several other defects including defective endocardial cushion (EC) and aberrant myofibrillogenesis have also been found. Cardiac neural crest defects in experimental embryos were analyzed and validated by the protein expression of NCAM and PGP 9.5. In addition, the protein expression of Bmp4, Msx1 and Pax3 involved in the development of cardiac neural crest was found to be reduced in the defective hearts. The mRNA expression of Bmp4, Msx1 and Pax3 was significantly down-regulated (p < 0.001) in the hearts of experimental embryos. Further, the proliferation index was significantly decreased (p < 0.05), whereas the apoptotic cells were significantly increased (p < 0.001) in the EC and the ventricular myocardium of the experimental embryos.

Conclusion

It is suggested that the down-regulation of genes involved in development of cardiac neural crest could contribute to the pathogenesis of maternal diabetes-induced congenital heart defects.     

Determination by Gas Chromatography-Mass Spectrometry of [N(5)]Adenine Incorporation into Endogenous Cytokinins and the Effect of Tissue Age on Cytokinin Biosynthesis in Datura innoxia Crown Gall Tissue

In this study gas chromatographic-mass spectrometric techniques have been used to identify and quantify the metabolic incorporation of [¹⁵N₅]adenine into zeatin and its metabolites by 3-week-old Datura innoxia Mill, crown gall tissue. In a parallel study the levels of endogenous cytokinins were also determined by the stable isotope dilution technique using deuterium (²H)-labeled internal standards. Incorporation levels of the [¹⁵N₅]adenine after 8 hours of incubation, expressed as a percentage of the endogenous cytokinins, were as follows: zeatin (1.0%), zeatin riboside (1.5%), and zeatin riboside 5′-phosphate (10.2%). These results are consistent with those observed in complementary experiments using [U-¹⁴C]adenine, and support the proposal that the cytokinin biosynthesis occurs primarily at the nucleotide level. The effect of tissue age on cytokinin biosynthesis, determined by [U-¹⁴C]adenine incorporation into cytokinins by tissues at varying growth stages, indicated a steady increase with time reaching maximal synthesis at five weeks following subculture after which the level of ¹⁴C incorporation into cytokinins declined.     

Mesenchymal stromal cell exosome–enhanced regulatory T-cell production through an antigen-presenting cell–mediated pathway

Background aims

The immunomodulatory property of mesenchymal stromal cell (MSC) exosomes is well documented. On the basis of our previous report that MSC exosomes increased regulatory T-cell (Treg) production in mice with allogenic skin graft but not in ungrafted mice, we hypothesize that an activated immune system is key to exosome-mediated Treg production.