scholarly journals Review of claudin proteins as potential biomarkers for necrotizing enterocolitis

Author(s):  
Victoria Griffiths ◽  
Niazy Al Assaf ◽  
Rizwan Khan

Abstract Background Claudin proteins are a component of tight junctions found in cell-cell adhesion complexes. A central feature of necrotizing enterocolitis (NEC) is intestinal permeability, with changes to claudin proteins potentially contributing to intestinal instability, inflammation, and the progression of NEC. A current area of interest is the development of a novel, noninvasive biomarker for the detection of NEC in neonates at risk of developing this disease, in order to reduce morbidity and mortality through earlier intervention. Aims This review aims to explore the relevance of claudin proteins in the pathophysiology of NEC and their potential usefulness as a biomarker. Methods This review was conducted using the search terms “claudin” + “necrotizing enterocolitis”, with 27 papers selected for review. Results Claudin proteins appear to have a role in the stability of the gut epithelium through the regulation of intestinal permeability, maturity, and inflammation. Formula feeding has been shown to promote inflammation and result in changes to claudin proteins, while breastfeeding and certain nutritional supplements lead to reduced inflammation and improved intestinal stability as demonstrated through changes to claudin protein expression. Preliminary studies in human neonates suggest that urinary claudin measurements may be used to predict the development of NEC. Conclusions Alterations to claudin proteins may reflect changes seen to intestinal permeability and inflammation in the context of NEC. Further research is necessary to understand the relevance of claudin proteins in the pathophysiology of NEC and their use as a biomarker.

1981 ◽  
Vol 60 (3) ◽  
pp. 5P-5P ◽  
Author(s):  
E. A. Fagan ◽  
R. Murphy ◽  
D. Bentley ◽  
V. S. Chadwick

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
A. Nagy ◽  
V. Voros ◽  
T. Tenyi

Aim:The authors present the Cotard's syndrome, a rare psychiatric condition, pointing out the latest results in terms of psychoneurology and classification of the phenomenon. The central feature of the syndrome is a nihilistic delusion, in which the patient denies his or her own existence and that of the external world.Method:We searched electronic scientific databases using the appropriate search terms; relevant articles were carefully reviewed. We also present three cases from our clinical practice.Results:After the overview of the latest biological and neuropsychological findings, the terminology, the nosology, the classification and the differential diagnostics are discussed. To sum up with useful information for the clinical practice, the possible treatment strategies, the course and the prognosis of the disease are also presented.Conclusions:The reported cases together with the reviewed literature suggest that a dimensional system of classifying Cotard's syndrome is preferable. At the one end of the spectrum is the presence of the pure nihilistic delusions, appearing as a symptom of an underlying psychiatric or neurological condition. The full-blown, classical syndrome as a diagnostic category forms the other end of the spectrum. The presented theoretical and practical aspects give a lead on deeper understanding, easier recognition and more adequate therapy of the Cotard's syndrome.


Author(s):  
Anruo Zhong ◽  
Xiaoming Lan ◽  
Yangfan Hu ◽  
Biao Wang

Abstract Magnetic skyrmions are attracting much attention due to their nontrivial topology and high mobility to electric current. Nevertheless, suppression of the skyrmion Hall effect and maintaining high velocity of skyrmions with low energy cost are two major challenges concerning skyrmion-based spintronic devices. Here we show theoretically that in a nano-beam suffering appropriate bending moment, both Bloch-type and Néel-type skyrmions move with a vanishing Hall angle under a current density smaller than that required when the bending is absent. Moreover, bending alone can be used to move skyrmions, whose velocity is solved analytically from the Thiele equation. Generally speaking, inhomogeneous elastic fields affect the stability and dynamics of skyrmions, where the local stability is dominantly determined by the local bulk stress. These findings throw new light on how to drive skyrmions straightly with lower energy cost, which is vital for utilizing skyrmions as information carriers.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Grace M. Lloyd ◽  
Jess-Karan S. Dhillon ◽  
Kimberly-Marie M. Gorion ◽  
Cara Riffe ◽  
Susan E. Fromholt ◽  
...  

Abstract Background The misfolding of host-encoded proteins into pathological prion conformations is a defining characteristic of many neurodegenerative disorders, including Alzheimer’s disease, Parkinson’s disease, and Lewy body dementia. A current area of intense study is the way in which the pathological deposition of these proteins might influence each other, as various combinations of co-pathology between prion-capable proteins are associated with exacerbation of disease. A spectrum of pathological, genetic and biochemical evidence provides credence to the notion that amyloid β (Aβ) accumulation can induce and promote α-synuclein pathology, driving neurodegeneration. Methods To assess the interplay between α-synuclein and Aβ on protein aggregation kinetics, we crossed mice expressing human α-synuclein (M20) with APPswe/PS1dE9 transgenic mice (L85) to generate M20/L85 mice. We then injected α-synuclein preformed fibrils (PFFs) unilaterally into the hippocampus of 6-month-old mice, harvesting 2 or 4 months later. Results Immunohistochemical analysis of M20/L85 mice revealed that pre-existing Aβ plaques exacerbate the spread and deposition of induced α-synuclein pathology. This process was associated with increased neuroinflammation. Unexpectedly, the injection of α-synuclein PFFs in L85 mice enhanced the deposition of Aβ; whereas the level of Aβ deposition in M20/L85 bigenic mice, injected with α-synuclein PFFs, did not differ from that of mice injected with PBS. Conclusions These studies reveal novel and unexpected interplays between α-synuclein pathology, Aβ and neuroinflammation in mice that recapitulate the pathology of Alzheimer’s disease and Lewy body dementia.


2021 ◽  
Vol 22 (6) ◽  
pp. 313-320
Author(s):  
M. S. Lur’e ◽  
O. M. Lur’e ◽  
A. S. Frolov

This study is devoted to the consideration of a method for assessing the stability of systems with pulse-width modulation, based on the linearization of its equivalent system with pulse-width modulation. An approximate study of the dynamic modes of operation of systems with pulse-width modulation, taking into account the stability for the system of automatic control of the supply current of electromagnets under the conditions of external and internal interference, is carried out. Variants of execution of schemes of pulse-width regulators for the power supply of an electromagnet based on a unipolar and bipolar element with pulse-width modulation are presented. The possibility of linearization of systems with pulse-width modulation for the subsequent detailed assessment of the stability of such systems is shown. The prospects of using functional differential equations for stability analysis of automatic systems with pulse-width modulation are shown. The frequency characteristics of an equivalent pulse system are analyzed using the example of a current stabilization system of high-power electromagnets with a pulse-width regulator, taking into account the replacement of the latitude modulation by the amplitude one. Based on the analysis of the resulting transfer function, which is a stable linearized equivalent open system, the ways of evaluating the stability of the original system with pulse-width modulation using the Nyquist stability criterion are proposed. The conclusion is made about the advantage of a system with PWM, in relation to a system with AIM, in terms of stability, and recommendations are given for the use of the obtained data in the analysis oftransients in such systems.


1985 ◽  
Vol 19 (9) ◽  
pp. 919-921 ◽  
Author(s):  
David A Clark ◽  
Jeffrey E Thompson ◽  
Leonard B Weiner ◽  
Julia A McMillan ◽  
Albert J Schneider ◽  
...  

2009 ◽  
Vol 26 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Augusto Zani ◽  
Marco Ghionzoli ◽  
Giuseppe Lauriti ◽  
Mara Cananzi ◽  
Virpi V. Smith ◽  
...  

2017 ◽  
Vol 71 (1) ◽  
pp. 31-43
Author(s):  
Christian Lange

Abstract The relationship between scholars working in the field of Islamic Studies and those affiliating themselves with Religious Studies (in the Netherlands, but also beyond) is plagued by a number of mutual misperceptions. These misperceptions should, and in fact can, be overcome. To argue this point, I (1) sketch the institutional framework of Islamic and Religious Studies in the Netherlands; (2) discuss a current area of fruitful interaction, viz., the study of Islamic ritual; and (3) end by some methodological reflections on future possibilities for collaboration between the two disciplines.


1992 ◽  
Vol 262 ◽  
Author(s):  
F. Ren ◽  
T. R. Fullowan ◽  
J. R. Lothian ◽  
P. W. Wisk ◽  
C. R. Abernathy ◽  
...  

ABSTRACTWe contrast the stability under bias-aging conditions of GaAs/AlGaAs HBTs utilizing highly Be- or C-doped base layers. Devices with Be doping display a rapid degradation of dc current gain and junction ideality factor. At 200°C, a 2 × 10 μm2 Be-doped device (4 × 1019cm−3 base doping) operated at a current density of 2.5 × 104 A. cm−2 shows a decrease in gain from 16 to 1.5 within 2h. Under the same conditions a C-doped device with even higher base-doping (7 × 1019 cm−3) is stable over periods of 36h, the longest time we tested our structures. The degradation of Be-doped devices is consistent with the mechanism of recombination-enhanced diffusion of interstitials into the adjoining layers. Similar results are obtained with Zn-doped devices. Since C occupies the As sub-lattice rather than the Ga sublattice as with Be and Zn, it is not susceptible to reaction with Ga interstitials injected during growth or bias-aging.


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