Isolated Hyperacute T-Waves in West Nile Encephalitis Indicating Atypical Variant of Stress-Induced Cardiomyopathy

Several cardiac outcomes have been reported with West Nile-encephalitis;however, the underlying pathophysiology remains complex. We present a 42-year-old female, with multiple sclerosis, whose neurological symptoms and respiratory decline were finally explained by the diagnosis of West Nile-encephalitis. During her admission, the isolated peaked T-waves indicated the underlying stress-induced cardiomyopathy. The absence of all other causes of hyperacute T-waves, their subsequent resolution with the resolution of infection and improvement in wall motion abnormalities, further supported the association. This case highlights the importance of considering hyperacute T-waves in an approach towards the diagnosis of WNV-encephalitis related atypical variant of stress-induced cardiomyopathy.

CHARACTERISTICS OF STRESS-INDUCED TRANSFORMATION AND MICROSTRUCTURE EVOLUTION IN Cu-BASED SMA

The mechanical behavior of shape memory alloys （SMAs） is closely related to the formation and evolution of its microstructures. Through theoretical analysis and experimental observations, it was found that the stress-induced martensitic transformation process of single crystal Cu-based SMA under uniaxial tension condition consisted of three periods： nucleation, mixed nucleation and growth, and merging due to growth. During the nucleation, the stress dropped rapidly and the number of interfaces increased very fast while the phase fraction increased slowly. In the second period, both the stress and the interface number changed slightly but the phase fraction increased dramatically. Finally, the stress and the phase fraction changed slowly while the number of interfaces decreased quickly. Moreover, it was found that the transformation could be of multi-stage： sharp stress drops at several strains and correspondingly, the nucleation and growth process occurred quasi-independently in several parts of the sample.

Nervous mechanisms of restraint water-immersion stress-induced gastric mucosal lesion

Stress-induced gastric mucosal lesion(SGML)is one of the most common visceral complications after trauma.Exploring the nervous mechanisms of SGML has become a research hotspot.Restraint water-immersion stress(RWIS)can induce GML and has been widely used to elucidate the nervous mechanisms of SGML.It is believed that RWIS-induced GML is mainly caused by the enhanced activity of vagal parasympathetic nerves.Many central nuclei,such as the dorsal motor nucleus of the vagus,nucleus of the solitary tract,supraoptic nucleus and paraventricular nucleus of the hypothalamus,mediodorsal nucleus of the thalamus,central nucleus of the amygdala and medial prefrontal cortex,are involved in the formation of SGML in varying degrees.Neurotransmitters/neuromodulators,such as nitric oxide,hydrogen sulfide,vasoactive intestinal peptide,calcitonin gene-related peptide,substance P,enkephalin,5-hydroxytryptamine,acetylcholine,catecholamine,glutamate,γ-aminobutyric acid,oxytocin and arginine vasopressin,can participate in the regulation of stress.However,inconsistent and even contradictory results have been obtained regarding the actual roles of each nucleus in the nervous mechanism of RWIS-induced GML,such as the involvement of different nuclei with the time of RWIS,the different levels of involvement of the sub-regions of the same nucleus,and the diverse signalling molecules,remain to be further elucidated.

Proteomics of the mediodorsal thalamic nucleus of rats with stress-induced gastric ulcer

BACKGROUND Stress-induced gastric ulcer(SGU) is one of the most common visceral complications after trauma. Restraint water-immersion stress(RWIS) can cause serious gastrointestinal dysfunction and has been widely used to study the pathogenesis of SGU to identify medications that can cure the disease. The mediodorsal thalamic nucleus(MD) is the centre integrating visceral and physical activity and contributes to SGU induced by RWIS. Hence, the role of the MD during RWIS needs to be studied.AIM To screen for differentially expressed proteins in the MD of the RWIS rats to further elucidate molecular mechanisms of SGU.METHODS Male Wistar rats were selected randomly and divided into two groups, namely, a control group and an RWIS group. Gastric mucosal lesions of the sacrificed rats were measured using the erosion index and the proteomic profiles of the MD were generated through isobaric tags for relative and absolute quantitation(iTRAQ) coupled with two-dimensional liquid chromatography and tandem mass spectrometry. Additionally, iTRAQ results were verified by Western blot analysis.RESULTS A total of 2853 proteins were identified, and these included 65 dysregulated(31 upregulated and 34 downregulated) proteins(fold change ratio ≥ 1.2). Gene Ontology(GO) analysis showed that most of the upregulated proteins are primarily related to cell division, whereas most of the downregulated proteins are related to neuron morphogenesis and neurotransmitter regulation. Ingenuity Pathway Analysis revealed that the dysregulated proteins are mainly involved in the neurological disease signalling pathways. Furthermore, our results indicated that glycogen synthase kinase-3 beta might be related to the central mechanismthrough which RWIS gives rise to SGU.CONCLUSION Quantitative proteomic analysis elucidated the molecular targets associated with the production of SGU and provides insights into the role of the MD. The underlying molecular mechanisms need to be further dissected.

Influence of bedding structure on stress-induced elastic wave anisotropy in tight sandstones

To understand the evolution of stress-induced elastic wave anisotropy,three triaxial experiments were performed on sandstone specimens with bedding orientations parallel,perpendicular,and oblique to the maximum principal stress.P-wave velocities along 64 different directions on each specimen were monitored frequently to understand the anisotropy change at various stress levels by fitting Thomsen’s anisotropy equation.The results show that the elastic wave anisotropy is very sensitive to mechanical loading.Under hydrostatic loading,the magnitude of anisotropy is reduced in all three specimens.However,under deviatoric stress loading,the evolution of anisotropic characteristics(magnitude and orientation of the symmetry axis)is bedding orientation dependent.Anisotropy reversal occurs in specimens with bedding normal/oblique to the maximum principal stress.P-wave anisotropyε0 is linearly related to volumetric strain Sv and dilatancy,indicating that stress-induced redistribution of microcracks has a significant effect on P-wave velocity anisotropy.The closure of initial cracks and pores aligned in the bedding direction contributes to the decrease of the anisotropy.However,opening of new cracks,aligned in the maximum principal direction,accounts for the increase of the anisotropy.The experimental results provide some insights into the microstructural behavior under loading and provide an experimental basis for seismic data interpretation and parameter selection in engineering applications.

EFFECT OF STRESS-INDUCED REACTIONS ON MORPHOLOGICAL STRUCTURE AND PROCESSABILITY OF PVC DURING PAN-MILLING

The effect of pan-milling on morphological structure,processability and properties of PVC was studied throughSEM,FTIR,granulometer,GPC and mechanical properties test in the hope of gaining ease in operation,needless ofplasticizers,a clean and efficient route for improving the processability of PVC through stress-induced reactions,fulfilling the idea of“plasticizing PVC by itself”.The experimental results show that during pan-milling at ambienttemperature,within 2-3 min,the microcrystalline structure of PVC becomes indistinct,the grain size of PVC is reducedfrom 130-160 μm to 1-50 μm the molecular weight of PVC is slightly decreased,the variation of molecular weightdistribution is indistinct,the plasticizing time and torque at balance drop a great deal from 71-132 s to 31-33 s and from18.2-22.1 Nm to 14.7-18.4 Nm,respectively,the processability of PVC is markedly improved,and the mechanicalproperties get enhanced too.

Stress-Induced Precipitation of Fineγ'-Phase and Thermodynamics Analysis

The microstructures of a single crystal Ni-base superalloy with [001] orientation were observed by means of TEM. Results showed that the fine γ' particles were precipitated in the γ matrix channels during the tensile deformation of the alloy. Thermodynamics analysis indicated that the solubility of elements M(Al,Ta) within the γ matrix may be changed when the alloy was deformed by the external applied stress. The tensile stress reduced the solubility of elements Al and Ta so as to occur the over-saturation and agglomeration of them, which promoted the precipitation of fine γ'-phase in the γ matrix.

Studies on Genetic Transformation of Fresh-cut Chrysanthemum Using DREB1A Promoted by Stress-induced Promoter rd29A

In this study, DERB1A transcription factor and stress-induced promoter rd29A were isolated respectively and amplified from Arabidopsis thaliana, se- quenced and analyzed by DNAsis. In addition, the stress-induced promoter rd29A was utilized to construct the plant expression vector of DERB1A, which was transformed into Agrobacterium tumefaciens. Furthermore, the transgenic regeneration system of fresh-cut chrysanthemum from callus to plantlets was established successfully. On this basis, chrysanthemum leaf-disc explants were genetically transformed with Agrobacterium-mediated method. Two positive transgenie plantlets were obtained in vitro. Based on PCR detection, DREB1A transcription factor was integrated into chrysanthemum genome, which laid the foundation for breeding new transgenie cultivars of fresh-cut chrysanthemum with high comprehensive stress resistance, good cmalitv and high field.

Preparation and evaluation of silymarin nanosuspensions for protective effects on stress-induced liver injury

OBJECTIVE To fabricate Silymarin(SM) nanosuspensions(NSs) and evaluate their protective effect on stress-induced liver injury. METHODS SM nanosuspensions were tailored by combination of the anti-solvent precipitation and high pressure homogenization(HPH); the formulations were optimized by central composite design. The pharmacokinetics and pharmacodynamics of SM-NSs were also performed.RESULTS In light of the quadratic mathematical equations derived from the Design of Expert Software,the optimal formulation of SM-NSs consisted of PVP 0.34% and F188 0.36%. The morphology of NSs was found to be spherical with a diameter of about 150 nm using transmission electron microscope(TEM)observation. The pharmacokinetics experiment demonstrated that oral administration of SM-NSs significantly increased its bioavailability compared to the coarse powder(Cmax: 9.03 ± 2.39 mg · L^(-1);AUMC_(0→∞):3757.35±227.19 mg·L^(-1)·h; AUC_(0→∞):171.84±26.61 mg·L^(-1)·h). In pharmacodynamics,it was found that restraint stress produced oxidative effects and increased serum AST and ALT levels in mice,both of which were significantly inhibited by SM and SM-NSs; in addition,administration of SM-NSs showed more effective prevention against acute liver injury than SM coarse suspensions(r^2=0.986,0.984,P<0.05). CONCLUSION The results suggest that fabricated SM-NSs exert potent hepatoprotective effects and attenuate restraint stress-induced liver injury. The study provides an effective approach to improving the property of SM,which can be used for treatment of liver diseases.

Research on Stress-Induced Nucleation ofε-Martensite in Fe-17Mn-10Cr-5Si-4Ni Polycrystalline Alloy

The relation between stacking fault overlap and martensitic nucleation in Fe-17Mn-10Cr-5Si-4Ni alloy was studied.The arrayed structure of dislocations and characteristics ofε-martensite formation under stress were in-situ observed by TEM.The results reveal thatε-martensite nucleates at the top of stacking faults overlapped band,where the ordered arrayed structure of Shockley partial dislocations exists.External stress promotesε-martensitic nucleation ability because of accelerated ordering of Shockley partial dislocations in stacking faults overlapped band.

High glucose augments stress-induced apoptosis in endothelial cells.

Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. EAhy 926 endothelial ceils were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide （HzO2） or tumour necrosis factor- α （TNF- α ）, following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of EAhy 926 cells to apoptosis in the presence of 500 gmol/L H2O2 , above that induced in normal glucose （P〈0.02）. A reduction of H2O2- and TNF- a -induced apoptosis occurred in both high and low glucose after treatment with dexamethasone （P〈0.05）. Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.

A simplified testing method for stress-induced of tunnel surrounding rock

A simple testing method for secondary or induced stress of surrounding rockwas presented by laboratory experiment, numerical simulation and in situ testing based onthe basic principle of the historical stress restoring method.First, stress equivalent coefficient,which key coefficient of stress restored testing, was obtained by laboratory experiment.Second, experimental results were examined using 3D finite element numericalanalysis and the influence factors were analyzed by 2D finite element numerical analysis.The correctness of induced stress measuring results in situ for highway tunnel wereproved by elastic mechanics theory solution and single-hole stress rescission method.Thenew simple method of induced stress measuring has important practical value for undergroundengineering induced stress field analysis.

Post-acute ischemic stroke hyperglycemia aggravates destruction of the blood-brain barrier

Post-acute ischemic stroke hyperglycemia increases the risk of hemorrhagic transformation,which is associated with blood-brain barrier disruption.Brain microvascular endothelial cells are a major component of the blood-brain barrier.Intercellular mitochondrial transfer has emerged as a novel paradigm for repairing cells with mitochondrial dysfunction.In this study,we first investigated whether mitochondrial transfer exists between brain microvascular endothelial cells,and then investigated the effects of post-acute ischemic stroke hyperglycemia on mitochondrial transfer between brain microvascular endothelial cells.We found that healthy brain microvascular endothelial cells can transfer intact mitochondria to oxygen glucose deprivation-injured brain microvascular endothelial cells.However,post-oxygen glucose deprivation hyperglycemia hindered mitochondrial transfer and exacerbated mitochondrial dysfunction.We established an in vitro brain microvascular endothelial cell model of the blood-brain barrier.We found that post-acute ischemic stroke hyperglycemia reduced the overall energy metabolism levels of brain microvascular endothelial cells and increased permeability of the blood-brain barrier.In a clinical study,we retrospectively analyzed the relationship between post-acute ischemic stroke hyperglycemia and the severity of hemorrhagic transformation.We found that post-acute ischemic stroke hyperglycemia serves as an independent predictor of severe hemorrhagic transformation.These findings suggest that post-acute ischemic stroke hyperglycemia can aggravate disruption of the blood-brain barrier by inhibiting mitochondrial transfer.

Mechanisms of Myocardial Stunning in Stress-Induced Cardiomyopathy

Stress-induced cardiomyopathy,in contrast to acute myocardial infarction,is a type of acute heart failure characterized by reversible left ventricular dysfunction.Cardiac imaging primarily reveals left ventricle myocardial stunning,81.7%of which is apical type.Emotional or psychological stress usually precedes the onset of stress-induced cardiomyopathy,which is increasingly being recognized as a unique neurogenic myocardial stunning disease.To distinguish between acute myocardial infarction and acute viral or auto-immune myocarditis,this review summarizes specific mechanisms of myocardial stunning in stress-induced cardiomyopathy,such as calcium disorders,metabolic alterations,anatomical and histological variations in different parts of the left ventricle,and microvascular dysfunction.

Stress-induced leakage current characteristics of PMOS fabricated by a new multi-deposition multi-annealing technique with full gate last process

In the process of high-k films fabrication, a novel multi deposition multi annealing （MDMA） technique is introduced to replace simple post deposition annealing. The leakage current decreases with the increase of the post deposition annealing （PDA） times. The equivalent oxide thickness （EOT） decreases when the annealing time（s） change from 1 to 2. Furthermore, the characteristics of SILC （stress-induced leakage current） for an ultra-thin SiO2/HfO2 gate dielectric stack are studied systematically. The increase of the PDA time（s） from 1 to 2 can decrease the defect and defect generation rate in the HK layer. However, increasing the PDA times to 4 and 7 may introduce too much oxygen, therefore the type of oxygen vacancy changes.

Surface Roughness of SiGe/Si(110) Formed by Stress-Induced Twins and the Solution to Produce Smooth Surface

Lattice-strained Si thin films grown onto SiGe(110)/Si(110) are attracting because of their potential to realize high-speed transistors. In this study we observe surface morphology of Si/SiGe/Si(110) using scanning electron microscopy and we also observe microstructure of the identical position using cross-sectional transmission electron microscopy. These results reveal that crossing of stress-induced twins causes remarkable surface roughness. We propose using vicinal substrate to avoid this phenomenon and our successive experimental results are shown in this paper.

Neurogenesis-enhancing effect of sodium ferulate and its role in repair following stress-induced neuronal damage

Ferulic acid (FA) is a ubiquitous phenolic acid of low toxicity, and sodium ferulate (SF) is its sodium salt. Our previous studies have revealed that FA shows neuroprotective effect and significant antidepressant- like effect. The aim of this study was to investigate its potential neurogenesis-enhancing effect and its role in repair following stress-induced neuronal damage. MTT assay was performed to measure the effect of SF on the growth of rat pheochromocytoma (PC12) cells;morphological and immunocytochemical meth- ods were used for assessing its differentiation-induc- ing action. Chronic mild stress (CMS) tests were per- formed to establish rat model of depression. The histopathology of animal brains was studied to ana- lyze CMS-induced morphological changes and the effect of SF on the repair of CMS-induced brain in- jury. The expressions of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and the proliferation of neural stem cell/neural progenitor cells were assessed in the hippocampi of chronic mild stress (CMS)-induced depression-like model rats by immunohistochemistry and bromodeoxyuridine (BrdU)- incorporation assays, respectively. Our in vitro tests showed that SF promoted the proliferation of PC12 cells in the concentration range of 5 - 320 μM, and induced PC12 cells to differentiate to more mature cells with the morphological characteristics and mo- lecular marker of neuronal-like cells. In vivo tests showed that SF up-regulated the expressions of NGF and BDNF, and induced the proliferation of neural stem cell/neural progenitor cells in the hippocampi of CMS-induced depression-like model rats. This study provides evidences that SF shows neurogenesis-en- hancing effect, and its antidepressant-like effect of SF may be related directly and closely to its above-men- tioned effect.

Rapid correction of chronic hyperglycemia and bone remodeling,warning against overdoing

It is widely recognized that chronic hyperglycemia decreases bone quality,although little is known about the impact of the rapid correction of chronic hyperglycemia on the quality of bone remodeling.This spotlight article explores this correlation by focusing on the stages of bone remodeling linked to glucose levels.

Balancing act:The dilemma of rapid hyperglycemia correction in diabetes management

The global diabetes surge poses a critical public health challenge,emphasizing the need for effective glycemic control.However,rapid correction of chronic hyperglycemia can unexpectedly trigger microvascular complications,necessitating a reevaluation of the speed and intensity of glycemic correction.Theories suggest swift blood sugar reductions may cause inflammation,oxidative stress,and neurovascular changes,resulting in complications.Healthcare providers should cautiously approach aggressive glycemic control,especially in long-standing,poorly controlled diabetes.Preventing and managing these complications requires a personalized,comprehensive approach with education,monitoring,and interdisciplinary care.Diabetes management must balance short and longterm goals,prioritizing overall well-being.This editorial underscores the need for a personalized,nuanced approach,focusing on equilibrium between glycemic control and avoiding overcorrection.

Steroid hyperglycemia: Prevalence, early detection and therapeutic recommendations: A narrative review

Steroids are drugs that have been used extensively in a variety of conditions. Although widely prescribed for their anti-inflammatory and immunosuppressive properties, glucocorticoids have several side effects, being hyperglycemia one of the most common and representative. In the present review, we discuss the main epidemiologic characteristics associated with steroid use, with emphasis on the identification of high risk populations. Additionally we present the pathophysiology of corticosteroid induced hyperglycemia as well as the pharmacokinetics and pharmacodynamics associated with steroid use. We propose a treatment strategy based on previous reports and the understanding of the mechanism of action of both, the different types of glucocorticoids and the treatment options, in both the ambulatory and the hospital setting. Finally, we present some of the recent scientific advances as well as some options for future use of glucocorticoids.