Neonatal cerebrovascular autoregulation.

Cerebrovascular pressure autoregulation is the physiologic mechanism that holds cerebral blood flow (CBF) relatively constant across changes in cerebral perfusion pressure (CPP). Cerebral vasoreactivity refers to the vasoconstriction and vasodilation that occur during fluctuations in arterial blood pressure (ABP) to maintain autoregulation. These are vital protective mechanisms of the brain. Impairments in pressure autoregulation increase the risk of brain injury and persistent neurologic disability. Autoregulation may be impaired during various neonatal disease states including prematurity, hypoxic-ischemic encephalopathy (HIE), intraventricular hemorrhage, congenital cardiac disease, and infants requiring extracorporeal membrane oxygenation (ECMO). Because infants are exquisitely sensitive to changes in cerebral blood flow (CBF), both hypoperfusion and hyperperfusion can cause significant neurologic injury. We will review neonatal pressure autoregulation and autoregulation monitoring techniques with a focus on brain protection. Current clinical therapies have failed to fully prevent permanent brain injuries in neonates. Adjuvant treatments that support and optimize autoregulation may improve neurologic outcomes

Large Tandem, Higher Order Repeats and Regularly Dispersed Repeat Units Contribute Substantially to Divergence Between Human and Chimpanzee Y Chromosomes

Comparison of human and chimpanzee genomes has received much attention, because of paramount role for understanding evolutionary step distinguishing us from our closest living relative. In order to contribute to insight into Y chromosome evolutionary history, we study and compare tandems, higher order repeats (HORs), and regularly dispersed repeats in human and chimpanzee Y chromosome contigs, using robust Global Repeat Map algorithm. We find a new type of long-range acceleration, human-accelerated HOR regions. In peripheral domains of 35mer human alphoid HORs, we find riddled features with ten additional repeat monomers. In chimpanzee, we identify 30mer alphoid HOR. We construct alphoid HOR schemes showing significant human-chimpanzee difference, revealing rapid evolution after human-chimpanzee separation. We identify and analyze over 20 large repeat units, most of them reported here for the first time as: chimpanzee and human ~1.6 kb 3mer secondary repeat unit (SRU) and ~23.5 kb tertiary repeat unit (~0.55 kb primary repeat unit, PRU); human 10848, 15775, 20309, 60910, and 72140 bp PRUs; human 3mer SRU (~2.4 kb PRU); 715mer and 1123mer SRUs (5mer PRU); chimpanzee 5096, 10762, 10853, 60523 bp PRUs; and chimpanzee 64624 bp SRU (10853 bp PRU). We show that substantial human-chimpanzee differences are concentrated in large repeat structures, at the level of as much as ~70% divergence, sizably exceeding previous numerical estimates for some selected noncoding sequences. Smeared over the whole sequenced assembly (25 Mb) this gives ~14% human--chimpanzee divergence. This is significantly higher estimate of divergence between human and chimpanzee than previous estimates.Comment: 22 pages, 7 figures, 12 tables. Published in Journal of Molecular Evolutio

The importance of skin manifestations, serology and nailfold (video)capillaroscopy in morphea and systemic sclerosis: current understanding and new insights

Since the field around morphea and systemic sclerosis (SSc) is evolving rapidly, this review approaches conventional as well as more recent clinical developments from a dermatological point of view. Skin manifestations are critical in sub-classifying these diseases ensuring a correct prognosis for these patients. They can be discretely present, and therefore, diagnosis can be challenging sometimes, implicating a thorough dermatological examination is mandatory. Furthermore, a growing amount of dermatologists perform nailfold videocapillaroscopy (NVC), a more recent reliable non-invasive imaging technique used for in vivo assessment of the microcirculation at the nailfold. After all, specific NVC-changes are present in a majority of patients with SSc. This way, dermatologists not only take part in the diagnosis process through clinical investigation but also through the use of a modern state of the art imaging technique that is becoming the golden standard in SSc multidisciplinary workup. In this review, current understandings for NVC in morphea and SSc are revised. So far, the role of NVC in the diagnosis/prognosis/classification of morphea patients has not been thoroughly investigated to make proper conclusions. As for SSc, it is well known that NVC contributes to the diagnosis and can make a fundamental difference especially when obvious clinical SSc signs are absent. This review emphasizes the (somewhat underestimated) role of dermatologists in the process of diagnosis and follow-up, and thus, the difference we can make for our patients and fellow colleagues in the multidisciplinary workup of SSc and morphea