Regulatory proteins in placental angiogenesis

The vasculature of the placenta plays a crucial role during the course of pregnancy in order to maintain the growing need of the fetus. Abnormal placental structure and function significantly increase the risk of stillbirth. Various growth factors and cytokines play an important role in the vasculogenesis and angiogenesis of placenta. These processes are stimulated by various pro-angiogenic factors. The activities of these factors are also stimulated by hypoxia. In some of the physiological phenomenon like ovulation, embryogenesis as well as in wound healing intense blood vessel growth can be seen similar to that seen in placenta. Therefore, factors that induce and maintain placental vascular growth and function are of considerable developmental and clinical significance. The total arterial architecture may also depend upon the pro-angiogenic factors. Hormones and other growth factors are other contributors of this vasculogenesis and angiogenesis. Any dysfunction of factors can lead to foetal hypoxia and related complications. This review describes the major growth factors and their significant role in vasculogenesis and angiogenesis of placenta.

Repetition-attenuation of auditory N1 is modulated by the phonological representations of spoken word-forms

Repeated auditory stimuli are usually found to elicit attenuated peak amplitude of the N1 component of the event related brain potential (ERP). While the repetition-attenuation of the auditory N1 has been found sensitive to some cognitive factors, less is known whether and how the representational properties of stimuli influence this physiological phenomenon. To further address this issue, we focus on the phonological representations of spoken word-forms, and hypothesise modulatory roles of two phonological features: the lexicality and its usage frequency of a word-form. To test this, we used a short-term habituation design with a factorial combination of the two features at two levels each (i.e., lexicality (real versus pseudo word-form) X frequency (high versus low frequency)). EEG was recorded from 30 native Mandarin-speaking participants while they were passively delivered with stimulations trains. Each train consisted of five presentation positions (S1 ~ S5), on which one word-form is presented repeatedly, separated by a brief, constant interstimulus interval. At the fourth presentation position (S4), we found greater N1 attenuation in low-frequency pseudo word-forms than in low-frequency real and high-frequency pseudo word-forms, respectively. The results support our representational modulation hypothesis, and provides the first evidence that representations of different phonological features interactively modulate the N1 repetition-attenuation. The brain function that underlies the phonological effects of the representational modulation on N1 repetition-attenuation might be sensory filtering.

Synaptic tau: A pathological or physiological phenomenon?

In this review, we discuss the synaptic aspects of Tau pathology occurring during Alzheimer’s disease (AD) and how this may relate to memory impairment, a major hallmark of AD. Whilst the clinical diagnosis of AD patients is a loss of working memory and long-term declarative memory, the histological diagnosis is the presence of neurofibrillary tangles of hyperphosphorylated Tau and Amyloid-beta plaques. Tau pathology spreads through synaptically connected neurons to impair synaptic function preceding the formation of neurofibrillary tangles, synaptic loss, axonal retraction and cell death. Alongside synaptic pathology, recent data suggest that Tau has physiological roles in the pre- or post- synaptic compartments. Thus, we have seen a shift in the research focus from Tau as a microtubule-stabilising protein in axons, to Tau as a synaptic protein with roles in accelerating spine formation, dendritic elongation, and in synaptic plasticity coordinating memory pathways. We collate here the myriad of emerging interactions and physiological roles of synaptic Tau, and discuss the current evidence that synaptic Tau contributes to pathology in AD.

Sound is Silence

This chapter investigates the possibility of talking about the fabric of sound. The claim is made that sound has no fabric of its own and is extended only through other sites and media. It is suggested, however, that we might talk about sound not as a fabric but as un fabriquer, a term that brings with it something of the asubjective, relational, and operational nature of sound. When thinking through this in terms of sound art, greater complexity arises since a human subject is necessarily interpolated into the relation, and the fabric of sound (which is to say its ontology) must be thought of from a phenomenological perspective. To do this, I use the philosophy of Merleau-Ponty, in particular his concept of a chiasmic relation out of which the perceptible world is produced as what he terms ‘the flesh of the world’. I contend that this concept, as outlined in his late philosophy, is problematic because it is hard to see how it can lead to the kind of experiential intersubjectivity that it argues for. This argument is unpacked through a consideration of the physiological phenomenon of otoacoustic emissions before going on to argue that art, and in this specific case sound art, may provide a solution to the conundrum of how such necessary intersubjectivity can arise, a suggestion that is prosecuted via a consideration of Jacob Kirkegaard’s Labyrinthitis, a work of sound art constructed out of otoacoustic emissions.

Extracellular Vesicles as Natural Delivery Carriers Regulate Oxidative Stress Under Pathological Conditions

Extracellular vesicles are cellular secretory particles that can be used as natural drug delivery carriers. They have successfully delivered drugs including chemotherapeutics, proteins, and genes to treat various diseases. Oxidative stress is an abnormal physiological phenomenon, and it is associated with nearly all diseases. In this short review, we summarize the regulation of EVs on oxidative stress. There are direct effects and indirect effects on the regulation of oxidative stress through EVs. On the one hand, they can deliver antioxidant substances or oxides to recipient cells, directly relieving or aggravating oxidative stress. On the other hand, regulate factors of oxidative stress-related signaling pathways can be delivered to recipient cells by the mediation of EVs, realizing the indirect regulation of oxidative stress. To the best of our knowledge, however, only endogenous drugs have been delivered by EVs to regulate oxidative stress till now. And the heterogeneity of EVs may complicate the regulation of oxidative stress. Therefore, this short review aims to draw more attention to the EVs-based regulation of oxidative stress, and we hope excellent EVs-based delivery carriers that can deliver exogenous drugs to regulate oxidative stress can be exploited.

Myoelectric Control: an alternative to Mirror Therapy

Evidence suggests that fifty to eighty percent (50-80%) of amputees conserve sensation in their missing limb after removal due to the presence of associated nerve endings. Most importantly, a large percentage of amputees experience episodic pain in the missing limb. This physiological phenomenon called phantom limb pain (PLP) has shown resistance to pharmaceutical treatments, but can be treated through mirror therapy. However, mirror therapy only yields temporary results and does not apply to bilateral amputees. Overcoming these challenges are the objectives of the present study. Using a surface electromyographic signal classification approach, this investigation intends to simulate the control of a missing limb within an immersive virtual environment. We predict that replacing mirror therapy with a more immersive “virtual therapy” can serve as a prolonged psychological solution to phantom limb pain.

Microcirculatory bed in reperfused flaps: modern possibilities for the correction of hemodynamic disorders (part III)

The paper presents an analysis of the literature data concerning the autoregulation of tissue blood flow in free axial flaps. Autoregulation of microcirculation is an extremely important physiological phenomenon that ensures the stability of peripheral blood circulation and adequate metabolism in organs and tissues, regardless of fluctuations in systolic blood pressure in the range of 80-160 mm Hg. The types of sludge and their origin are described. Technologies of elimination of erythrocyte aggregates (sludge) by using dextrans of different molecular weights and pentoxifylline are discussed. Controlling the duration of primary ischemia, maintaining adequate perfusion pressure in the replants of the limbs and in free flaps, as well as reducing the peripheral vascular resistance in them, will make it possible to level the disturbances in the autoregulation of microcirculation in the reperfused tissues, ensuring the stability of capillary pressure.

Dissociation between exercise intensity thresholds: mechanistic insights from supine exercise

Introduction/purpose: This study tested the hypothesis that the respiratory compensation point (RCP) and breakpoint in deoxygenated [heme] (deoxy[heme]BP, assessed via near-infrared spectroscopy (NIRS)) during ramp incremental exercise would occur at the same metabolic rate in the upright (U) and supine (S) body positions. Methods: Eleven healthy men completed ramp incremental exercise tests in U and S. Gas exchange was measured breath-by-breath and time-resolved-NIRS was used to measure deoxy[heme] in the vastus lateralis (VL) and rectus femoris (RF). Results: RCP (S: 2.56 ± 0.39, U: 2.86 ± 0.40 L.min-1, P = 0.02) differed from deoxy[heme]BP in the VL in U (3.10 ± 0.44 L.min-1, P = 0.002), but was not different in S in the VL (2.70 ± 0.50 L.min-1, P = 0.15). RCP was not different from the deoxy[heme]BP in the RF for either position (S: 2.34 ± 0.48 L.min-1, U: 2.76 ± 0.53 L.min-1, P > 0.05). However, the deoxy[heme]BP differed between muscles in both positions (P < 0.05), and changes in deoxy[heme]BP did not relate to delta RCP between positions (VL: r = 0.55, P = 0.080, RF: r = 0.26, P = 0.44). The deoxy[heme]BP was consistently preceded by a breakpoint in total[heme], and was, in turn, itself preceded by a breakpoint in muscle surface electromyography (EMG). Conclusions: RCP and the deoxy[heme]BP can be dissociated across muscles and different body positions and, therefore, do not represent the same underlying physiological phenomenon. The deoxy[heme]BP may, however, be mechanistically related to breakpoints in total[heme] and muscle activity.

A model of symbiomemesis: machine education and communication as pillars for human-autonomy symbiosis

Symbiosis is a physiological phenomenon where organisms of different species develop social interdependencies through partnerships. Artificial agents need mechanisms to build their capacity to develop symbiotic relationships. In this paper, we discuss two pillars for these mechanisms: machine education (ME) and bi-directional communication. ME is a new revolution in artificial intelligence (AI) which aims at structuring the learning journey of AI-enabled autonomous systems. In addition to the design of a systematic curriculum, ME embeds the body of knowledge necessary for the social integration of AI, such as ethics, moral values and trust, into the evolutionary design and learning of the AI. ME promises to equip AI with skills to be ready to develop logic-based symbiosis with humans and in a manner that leads to a trustworthy and effective steady-state through the mental interaction between humans and autonomy; a state we name symbiomemesis to differentiate it from ecological symbiosis. The second pillar, bi-directional communication as a discourse enables information to flow between the AI systems and humans. We combine machine education and communication theory as the two prerequisites for symbiosis of AI agents and present a formal computational model of symbiomemesis to enable symbiotic human-autonomy teaming. This article is part of the theme issue ‘Towards symbiotic autonomous systems’.

Systemic rosiglitazone administration leads to cementocytes apoptosis in wild type mice

It has been shown that a class of drugs for diabetes control, the thiazolidinediones, leads to increased apoptosis in osteocytes. Considering the correlations between osteocytes and cementocytes, the aim of this study was to demonstrate the apoptosis on cementocytes of wild type mice that had received rosiglitazone. Twenty-four male C57BL/6 mice were divided into 3 groups: 1 control, which received only the vehicle administration via oral for 1 week (PBS+DMSO 10%) and other two groups, which received 10 mg/kg of RGZ+PBS+DMSO 10% for 1 or 2 weeks, respectively. Upon completion of the time courses, mice were killed by CO2 and the mandibles were dissected and subjected to routine histotechnical processing. The sections were analyzed through transferase-mediated dUTP nick-end labeling (TUNEL) and 4’,6- diamidino-2-phenylindole (DAPI) staining of nuclear morphology (α=0.05). Control group showed significantly lower apoptotic cells/total cells ratio when compared to the experimental groups with TUNEL and DAPI methods (p=0.010 and 0.004, respectively). TUNEL method showed approximately 20% TUNEL-positive cementocytes in control and 26% in both experimental groups, while the DAPI technique showed approximately 32% of DAPI-positive cementocytes in control and 38% to 40% in experimental groups. The rosiglitazone systemic administration can lead to cementocytes apoptosis in mice. Despite the differences between the experimental and control groups, the death of cementocytes occurred as a physiological phenomenon, important in understanding the role of these cells in periodontal tissue.