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Biomedical subjects

Vladimir Yutkin

Publications and source records attributed to Vladimir Yutkin.

3 recordsLinked to original sources

Decidual NK cells regulate key developmental processes at the human fetal-maternal interface.

Human CD56(bright) NK cells accumulate in the maternal decidua during pregnancy and are found in direct contact with fetal trophoblasts. Several mechanisms have been proposed to explain the inability of NK cells to kill the semiallogeneic fetal cells. However, the actual functions of decidual NK (dNK) cells during pregnancy are mostly unknown. Here we show that dNK cells, but not peripheral blood-derived NK subsets, regulate trophoblast invasion both in vitro and in vivo by production of the interleukin-8 and interferon-inducible protein-10 chemokines. Furthermore, dNK cells are potent secretors of an array of angiogenic factors and induce vascular growth in the decidua. Notably, such functions are regulated by specific interactions between dNK-activating and dNK-inhibitory receptors and their ligands, uniquely expressed at the fetal-maternal interface. The overall results support a 'peaceful' model for reproductive immunology, in which elements of innate immunity have been incorporated in a constructive manner to support reproductive tissue development.

Angiogenesis Inducing Agents↗

Do atherosclerosis and chronic bladder ischemia really play a role in detrusor dysfunction of old age?

OBJECTIVES: To determine whether atherosclerosis-induced chronic pelvic ischemia plays a role in the pathogenesis of aging bladder dysfunction. METHODS: Old (70 weeks of age), apolipoprotein E gene knockout (APOEKO) mice, known to develop atherosclerosis spontaneously were used. A group of 70-week-old C57B mice were used as controls. The mice were killed and bladder smooth muscle strips obtained for in vitro contractile force determinations. The maximal contractions in response to 110 mM KCl, 10(-5) M bethanechol, and resting muscle tone were compared. The abdominal aortas and iliac arteries were harvested from the mice, and computerized image analysis was used to determine the percentage of surface area of atherosclerosis in each mouse. RESULTS: Although the APOEKO mice had massive atherosclerosis of the abdominal aortas and iliac arteries (lesion surface area +/- SEM 15.93% +/- 3.02%, n = 4), the control mice (n = 5) had no atherosclerosis at all. No statistically significant difference was found in detrusor function (KCl 0.48 +/- 0.11 versus 0.49 +/- 0.05, bethanechol 0.11 +/- 0.02 versus 0.13 +/- 0.04, tone 0.063 +/- 0.019 versus 0.07 +/- 0.004, respectively) between the APOEKO mice (n = 6) and the control mice (n = 6). CONCLUSIONS: Pelvic atherosclerosis caused no statistically significant changes in bladder smooth muscle contractile responses to bethanechol, KCl, or resting tone. The difference between these and previously reported results may have been a result of the more gradual onset of atherosclerosis in our model, which better mimics pelvic organ ischemia in the elderly.

Aging↗

Regeneration of myenteric plexus in the mouse colon after experimental denervation with benzalkonium chloride.

Recent reports suggest a far greater plasticity in nerve tissue than previously believed. As the digestive tract is exposed to a variety of insults, this question is relevant to enteric nerves, but little is known about their ability to recover from damage. To address this problem, we ablated the myenteric plexus of the mouse colon with the detergent benzalkonium chloride (BAC) and followed the ensuing morphologic changes for up to 60 days by using light- and electron microscopy. We found that, 2 days after BAC application, the treated area was essentially devoid of intact nerve elements. From day 7, new nerve fibers were observed within the denervated region. This growth progressed until, at days 30-60, newly grown nerve fibers were present in most of this region, and the pattern of muscle innervation was similar to the normal one. At least part of these fibers originated at neurons within intact ganglia surrounding the denervated region. The cross-sectional area of neurons near the denervated region at day 14 was 52% greater than controls. Glial cells were closely associated with the regenerating nerve fibers. From day 14 onward, we observed undifferentiated cells and differentiating neurons in ganglia surrounding the denervated region, and by day 30, new neurons were present in the myenteric region, along with regenerating nerve fibers. We conclude that the myenteric plexus is endowed with a considerable ability of regeneration and plasticity. The results provide evidence for the presence of stem cells and for an adult neurogenesis in this plexus.

Animals↗