Changes of enzyme activity in the rat liver at different age in circadian cycle

Most of the biological processes in the living organisms of both animals and man are known to be of rhythmical nature. Variability of enzymatic activity in circadian cycle depends on many factors among other on age, sexual maturity, diet as well as medication. The results obtained in our studies indicate, that the activity changes of acid phosphatase and ATP-ase Mg++ dependent in the liver of all the examined age groups were of 24 hour circadian rythm. As to the acid phosphatase activity the results of this experiments showed that in circadian cycle in all examined age groups there is only one peak of elevated activity. ATP-ase Mg++ dependent showed two activity peaks appearing at the same hour both in 30 and 60 days old animals. It should be noticed that the activities of ATP-ase Mg++ dependent in 100 day old animals were two times higher than in 30 and 60 days old rats.     

Structural characterization of lipid A component of Erwinia carotovora lipopolysaccharide

The chemical structure of the lipid A component of lipopolysaccharide excreted into the liquid medium by the plant pathogenic enterobacterium Erwinia carotovora FERM P-7576 was characterized. It consists of a -1, 6-linked glucosamine disaccharide which carries ester-and amide-bound fatty acids and phosphate similar to the lipid A from other gram-negative bacteria. The lipid A preparation was not uniform in the number and composition of the fatty acids linked to the disaccharide. Four prominent lipids A were involved, they were composed of five to seven residues of fatty acid. Among them the major component was hexa-acyl lipid A, in which the hydroxyl group at position 3 and the amino group of the non-reducing glucosamine unit carry 3-dodecanoyl-oxytetradecanoyl residues. Positions 2 and 3 of the reducing glucosamine unit were substituted by 3-hydroxytetradecanoic acid. In the hepta-acyl lipid A, an additional hexadecanoic acid was linked to the hydroxyl group of the 3-hydroxytetradecanoyl residue at position 2 of the hexa-acyl lipid A. Two penta-acyl lipids A were the homologs of the hexa-acyl lipid A with decreasing acylation. Dodecanoic acid was missing from one, and 3-hydroxytetradecanoic acid from another. 3-Dodecanoyloxytetradecanoyl residue at position 3 differentiates E. carotovora lipid A from that of other gram-negative bacteria.Abbreviations LPS lipopolysaccharide - GlcN glucosamine - KDO 3-deoxy-d-manno-octulosonic acid - FAB-MS fast atom bombardment mass spectrometry - u atomic mass unit     

scRNA-seq Analysis of Hemocytes of Penaeid Shrimp Under Virus Infection

Marine Biotechnology - The classification of cells in non-model organisms has lagged behind the classification of cells in model organisms that have established cluster of differentiation marker...     

Differences in the stemness characteristics and molecular markers of distinct human oral tissue neural crest‐derived multilineage cells

ObjectivesAlthough multilineage cells derived from oral tissues, especially the dental pulp, apical papilla, periodontal ligament, and oral mucosa, have neural crest‐derived stem cell (NCSC)‐like properties, the differences in the characteristics of these progenitor cell compartments remain unknown. The current study aimed to elucidate these differences.Material and methodsSphere‐forming apical papilla‐derived cells (APDCs), periodontal ligament‐derived cells (PDLDCs), and oral mucosa stroma‐derived cells (OMSDCs) from the same individuals were isolated from impacted developing teeth. All sphere‐forming cells were characterized through biological analyses of stem cells.ResultsAll sphere‐forming cells expressed neural crest‐related markers. The expression of certain tissue‐specific markers such as CD24 and CD56 (NCAM1) differed among tissue‐derived cells. Surprisingly, the expression of only CD24 and CD56 could be discriminated in human tissues. Although APDCs and PDLDCs exhibited greater mineralized cell differentiation than OMSDCs, they exhibited poorer differentiation into adipocytes in vitro. In immunocompromised mice, APDCs formed hard tissues better than PDLDCs and OMSDCs.ConclusionsAlthough cells with NCSC‐like properties present the same phenotype, they differ in the expression of certain markers and differentiation abilities. This study is the first to demonstrate the differences in the differentiation ability and molecular markers among multilineage human APDCs, PDLDCs, and OMSDCs obtained from the same patients, and to identify tissue‐specific markers that distinguish tissues in the developing stage of the human tooth with immature apex.

This study illustrates that neural crest‐derived cells from distinct oral tissues, namely the apical papilla, periodontal ligament, and oral mucosa, have varying differentiation potential, and tissue‐derived cell‐specific molecular markers have been identified. CD24 and NCAM1/CD56 expression were found to differ among multilineage oral tissue‐derived cells, similar to our observation in human tissue.     

'Working' cardiomyocytes exhibiting plateau action potentials from human placenta-derived extraembryonic mesodermal cells

The clinical application of cell transplantation for severe heart failure is a promising strategy to improve impaired cardiac function. Recently, an array of cell types, including bone marrow cells, endothelial progenitors, mesenchymal stem cells, resident cardiac stem cells, and embryonic stem cells, have become important candidates for cell sources for cardiac repair. In the present study, we focused on the placenta as a cell source. Cells from the chorionic plate in the fetal portion of the human placenta were obtained after delivery by the primary culture method, and the cells generated in this study had the Y sex chromosome, indicating that the cells were derived from the fetus. The cells potentially expressed 'working' cardiomyocyte-specific genes such as cardiac myosin heavy chain 7beta, atrial myosin light chain, cardiac alpha-actin by gene chip analysis, and Csx/Nkx2.5, GATA4 by RT-PCR, cardiac troponin-I and connexin 43 by immunohistochemistry. These cells were able to differentiate into cardiomyocytes. Cardiac troponin-I and connexin 43 displayed a discontinuous pattern of localization at intercellular contact sites after cardiomyogenic differentiation, suggesting that the chorionic mesoderm contained a large number of cells with cardiomyogenic potential. The cells began spontaneously beating 3 days after co-cultivation with murine fetal cardiomyocytes and the frequency of beating cells reached a maximum on day 10. The contraction of the cardiomyocytes was rhythmical and synchronous, suggesting the presence of electrical communication between the cells. Placenta-derived human fetal cells may be useful for patients who cannot supply bone marrow cells but want to receive stem cell-based cardiac therapy.     

Factors contributing to cerebral hypomyelination in the growth hormone-deficientlittle mouse

We attempted to delineate the events leading to hypomyelination in the brain of thelittle mouse, a promising murine model of isolated growth hormone deficiency. At 20 days of age, the mutant mouse brain weighed less than its normal counterpart, and this difference in brain weight persisted. Increase in CNPase activity was found to be suppressed in the cerebrum throughout the developmental stage, but not in the other parts of the brain. Differences in cerebral DNA content between thelittle and normal mice first became apparent on the 10th day of age. Thereafter, the rate of increase in thelittle brain consistently lagged behind the normal. [³H]Thymidine incorporation into the DNA fraction in vivo on the 7th day of age, when glial cell proliferation in the normal cerebrum is most active, was approximately half that of the controls in all parts of thelittle brain. These findings indicate that the hypomyelination of the mutant cerebrum might result from reduced oligodendroglial proliferation due to growth hormone deficiency.     

Genetic exchange between two freshwater apple snails, Pomacea canaliculata and Pomacea maculata invading East and Southeast Asia

Two species of apple snails, Pomacea canaliculata and Pomacea maculata (formerly Pomacea insularum), have invaded many countries of East and Southeast Asia from their native range in South America. This study investigated the genetic structure of the two species invading these areas. Phylogenetic analysis based on sequences of the nuclear gene elongation factor 1-alpha (EF1α) detected two well-supported clades (Clade C and Clade M). Both P. canaliculata and P. maculata were represented in each clade. Some snails had both Clade C and Clade M EF1α sequences. These results suggest genetic exchange between snails of the two clades. A mating experiment between P. canaliculata with Clade C EF1α sequences and P. maculata with Clade M EF1α sequences resulted in viable F1 progeny under laboratory conditions. The genetic exchange was also inferred in some populations collected from Argentina, suggesting an existence of hybrid in the native range. Simple identification of EF1α types using a restriction enzyme, ApaLI, detected significant geographical structure of the EF1α variants in the invaded area. The divergent geographical structure could have resulted from either the founder effect or the bridgehead effect, although further genetic analysis is needed to clarify this. Average individual egg weight, which is an indicator of egg size, was higher in P. canaliculata than P. maculata in both field and laboratory reared samples, suggesting that some (probably most) P. canaliculata and P. maculata invading East and Southeast Asia still maintain species-specific populations.