Which can affect plaque vulnerability. Recent studies have highlighted that the placement of a stent against the artery wall may affect the arterial mechanical environment in very profound way. Stent application may directly injured endothelium through a mechanical stretching action that produces endothelial damage and denudation. Moreover, changes in flow patterns after stent positioning have been observed in experimental/computational flow study and include large-scale vortex formation and strut-spacing dependent flow stagnation. The low shear stresses associated with flow stagnation could likely induce, together with endothelial damage, vascular changes that are responsible of intimal hyperplasia, a leading cause of restenosis which occurs in 20–30% of patients within 6–12 months after primary stenting. Although several groups have reported that low shear stress compared to physiological one may affect gene expression MK-4827 profile of endothelial cells in different experimental systems, it is still unclear whether an invasive intervention like stent procedure may influence the transcriptional response of endothelium. To study the simultaneous effects of both changes in shear stress and stent application on endothelial gene expression, we have developed an experimental model of laminar flow bioreactor system with human cultured endothelial cells exposed or not exposed to stent procedure. RNA expression from different experimental conditions has been evaluated through the Affymetrix platform. The most relevant result of our work is that low shear stress in presence of stent is the experimental condition that modulates the highest number of genes. Indeed, we have observed that variations on genetic expression caused by flow plus stent procedure are higher than those caused by only flow or only stent application. Previous cellular model showed that physiological shear stress up-regulates genes with anti-atherogenic potential effect and down-regulates those with a pro-atherogenic behaviour, while the presence of low shear non-laminar flow is sufficient to induce a gene expression profile that pre-disposes the endothelium to the initiation and development of atherosclerotic lesions. However, it is unknown whether an invasive intervention like stent procedure, that introduces new structural changes in vascular compartment and in hemodynamic forces, may affect the transcriptional response of endothelial cells. To approach this lack of information, we studied the genetic expression profile of HUVEC submitted to different mechanical stimuli by Affymetrix technology searching for differently regulated genes in human endothelial cells. Using a bioinformatics tool, we found that genes involved in cytoskeleton organization and extracellular matrix are significantly down-expressed in disturbed shear stress. Most of them are linker proteins and regulators of intracellular microfilaments that mediate local trafficking of organelles and play a role in regulating the cell cytoskeleton and shape. Others are component of extracellular matrix or are regulators of its turnover.
Monthly Archives: August 2020
For new acaricide targets or alternative methods of tick control requiring cloning
MK-1775 Continued dependence on traditional chemical methods is becoming increasingly problematic in the face of ever greater demand for environmental protection and fear of chemical poisoning. To search for alternatives to chemical control, a better understanding of the neurologic processes that control basic tick physiological processes is needed. Ixodid ticks must gorge on blood, often increasing 100 fold in body size, in order to stimulate tissue development, ecdysis, mating and reproduction. Precisely how the tick’s nervous system regulates these biological processes is largely unknown. During feeding, some synganglion cells, especially the neurosecretory cells, increase in size and accumulate neurosecretory substances. Neurohormones and neurotransmitters play key roles in tick development and physiology. Work has been conducted examining their occurrence in selected tissues in ticks such as the hemocytes, midgut, ovaries, and salivary glands. However, much of the work on neurotransmitters focuses on the dopaminergic system in the salivary glands. Much less is known about the transcribed genes in the tick synganglia, largely because of the difficulty in extracting sufficient amounts of tissue. Advances in sequencing technology now allow researchers to rapidly obtain large amounts of data from a small amount of tissue. Recent work by Simo et al. showed the existence of a complex neuropeptidergic network extending to different body tissues as well as within the synganglion. However, the molecular basis for understanding just how these complex neurohormone-controlled networks regulate tick physiological functions remains to be determined. To this end, a global search to identify and characterize the numerous molecules expressed in the synganglion is needed. Transcriptomics offers an excellent tool to approach this problem. Using 454 pyrosequencing, Bissinger et al. generated a cDNA library of expressed genes in the synganglion of adult female American dog ticks, Dermacentor variabilis and predicted many of the neuropeptides, neuropeptide receptors, neurotransmitters, iron transport proteins, transmembrane proteins, stress reduction proteins and numerous housekeeping genes. Previous studies by Donohue et al. using similar methods identified 14 neuropeptides and 5 neuropeptide receptors in this same species. Transcriptome analysis of the synganglion of the brown dog tick, Rhipicephalus sanguineus, was done with cDNA library construction in phage resistant Escherichia coli. However, this method yielded a total of only 1008 ESTs sequenced, with only 603 remaining after removal of vector contamination that could be clustered into unique transcripts. Neuropeptides and their receptors have also been predicted in several species of hard ticks using bioinformatics and immunohistochemistry and identified by MALDI-TOF/ TOF mass spectrometry. Despite these few studies, there is a paucity of information about the neurobiology of ticks. Solexa/Illumina, 454 pyrosequencing, and other next generation sequencing technologies provide high levels of coverage far exceeding previous methods.
Acaricide resistance has become widespread causing perhaps interact antagonistically with patient treatment
Moreover, there are several limitations in the interpretation of sympathetic response to vasoactive drugs, among them nitroprusside inhibition of sympathetic neurotransmission, or unpredictable effects of cardiac loading conditions on low-pressure mechanoreceptor nerve firing. We have not investigated other reflexes known to increase sympathetic outflow. Metabolic and mechanical stimuli from the contracting muscles can lead to an increase in SNS activity by taking a route which bypasses the classical afferent baroreflex pathway and does not involve the solitary tract nuclei in the brainstem. This mechanism has been suggested in a case-report of post physical exercise TTC. However in our study, physical exercise has not been identified as a trigger factor leading to TTC. Moreover mechanoreflex analysis implies the use of a handgrip test, difficult to perform in our cohort of very elderly patients and poorly reproducible. Activation of peripheral chemoreceptors leads to sympathetic activation, but in the present study, factors known to increase peripheral chemoreceptor activity in CHF patients such as creatinine clearance, baseline oxygen saturation and hemoglobin levels were similar in both groups. We have ICI 182780 previously shown that chemoreflex activation can contribute to sympathetic baroreflex impairment. Hence it cannot be excluded that autonomic dysfunction in TTC could be mediated by peripheral chemoreflex activation. The effect of the treatment on SNS activity is also a possible limitation of our study. For ethical and clinical reasons treatment was not withdrawn. However the percentage of patients treated with b-blockers and renin-angiotensin-aldosterone-system blockers was not significantly different between the two groups. Ticks are obligate blood-feeding ectoparasites that serve as vectors of the causative agents of many important diseases affecting humans and animals, e.g., Lyme disease, Rocky Mountain spotted fever, tick-borne encephalitis, anaplasmosis, babesiosis and many others. The black-legged tick, Ixodes scapularis, is one of the most important vectors of infectious diseases to humans and animals throughout large areas of the United States and Canada. I. scapularis is the primary vector of the microbial agents of Lyme disease, human granulocytic anaplasmosis, human babesiosis, relapsing fever and an encephalitis-causing agent. Lyme disease is the most commonly reported vector-borne disease in the northern temperate zone regions of the northern hemisphere with 24,364 confirmed cases in the United States in 2011. Despite the many zoonotic diseases caused by tick-borne pathogens, control of ticks is still largely dependent on the use of chemical acaricides, with traditional acaricide targets being primarily neurologically-based. The central nervous system in ticks is composed of a single mass called the synganglion. Despite the fact that most acaricides target the nervous system, relatively little is known about tick neurobiology and how bloodfeeding and mating affect gene expression in the synganglion.
This activity has been well studied to the transgenic HNP-1 in neutrophils would be expected
The reason for their low content is unknown. Mice transgenic for a-defensins not dependent on C/EBP-e, e.g. the enteric human defensin 5 or 6, have shown expression levels comparable to human conditions as mice naturally express enteric a-defensins. An explanation for the low HNP-1 expression in the transgenic HNP-1 mouse could be lack of responsiveness to murine C/EBPe. To test this, we transduced human C/EBP-e into primary bone marrow cells of the transgenic HNP-1 mouse. Treatment with histone LEE011 deacetylase inhibitors might alleviate this inhibition. The integration site itself is another important factor which determines transgenic gene expression. Such positions effects are in general suppressive and more prominent if multiple nearly identical transcription factors are juxtaposed. Such phenomena may very well influence HNP-1 expression in the transgenic mouse in which approximately 20 bacterial artificial chromosome inserts, each containing 4 copies of DEFA1 as well as a truncated version of the DEFA3 gene, are integrated into a single chromosomal site. We have previously shown that unprocessed proHNP is primarily secreted into the bone marrow plasma, whereas fully processed HNP is retained in azurophil granules. Diminished posttranslational cleavage of proHNP could thus contribute to the shortage of HNPs observed in neutrophils of SGD patients. The enzymes responsible for posttranslational processing of proHNP are still not known and it is possible that these might be expressed under control of C/EBP-e albeit processing ceases when C/EBP-e expression is at its peak. We found intact posttranslational processing of HNP-1 by pulsechase biosynthesis, but diminished amounts by Western blotting. Infections remain a major cause of morbidity and mortality in the world especially in Low-and-Middle Income Countries. Antibiotics have been a significant force in reducing mortality in bacterial infections. However the number of effective antibiotics have been diminishing due to emerging bacterial resistance. Recently identified mechanisms of bacterial resistance such as New Delhi metallo-b-lactamase 1 may have grave consequences. Resistance is not only rapidly spreading in hospitals in the cities, but also in the community and in rural areas. The effectiveness of even life saving antibiotics have diminished with Escherichia coli resistance to ceftazidime and cefotaxime as high as 70% and 80% respectively in intensive care settings. Among the factors contributing to bacterial resistance, antibiotic consumption, both individual and aggregate, appear to have a major role. Irrational use of antibiotics is a factor in many countries such as India. In 2001, the WHO Strategy for Containment of Antimicrobial Resistance suggested steps to ensure rational use of antibiotics. One of the major strategies suggested was formulation of antibiotic stewardship programmes with development of antibiotic policy guidelines being a core component. The key purpose of guidelines is to improve rational antibiotic use.
Although increased content is associated with increased RBP4 concentrations be converted into industrial platform chemicals
A paradoxically positive adiponectin-endothelial activation relationship was also documented in white patients with RA. The potential role of RBP4 in atherogenesis and CVD risk stratification in RA has, to our knowledge, not been investigated. In the present study, we measured RBP4 concentrations, surrogate markers of enhanced early atherogenesis comprising E-selectin, vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and monocyte chemoattractant protein-1, and common carotid artery intima-media thickness and carotid artery plaque by ultrasound in both black and white patients with RA. We examined the independent relationships of RBP4 concentrations with cardiometabolic risk, endothelial activation and carotid atherosclerosis. In this RA study, adiposity was not associated with RBP4 concentrations. However, obesity adversely influenced the impact of this adipokine on atherosclerosis. Indeed, RBP4 concentrations were independently related to increased carotid Axitinib atherosclerosis only in patients with overall and abdominal obesity. Further, although RBP4 concentrations were lower in black compared to white patients, they were associated with atherosclerosis in the former but not the latter. This was possibly due to the far larger prevalence of excess adiposity in black compared to white patients. Consideration of RBP4 concentrations may improve cardiovascular risk stratification in RA. Paradoxical adipokine – CVD risk associations as we found between RBP4 concentrations and metabolic risk and endothelial activation, were previously reported. Such relations are thought to represent a compensatory change in adipokine production in the presence of chronic vascular disease and aimed at reducing metabolic risk. However, we found that the presence of plaque did not influence the impact of RBP4 concentrations on cardiovascular risk. By contrast, the inverse RBP4 – CVD risk associations were mostly reproduced only in patients with adverse traditional or nontraditional cardiovascular risk profiles. Our cross-sectional study design precludes drawing inferences on the direction of causality. Additionally, our findings on the associations of RBP4 concentrations with metabolic risk factors and endothelial activation differ and in fact contrast to those previously reported in non-RA subjects. Therefore, these relations need further study. RBP4 induces insulin resistance. We did not directly assess this metabolic risk factor. RBP4 concentrations were nonetheless not associated with the triacylglycerols-HDL cholesterol and leptin-adiponectin ratios, which are surrogate markers of insulin resistance. Future studies on the potential impact of RBP4 on metabolic risk in RA should include markers of insulin resistance such as the homeostasis model assessment of insulin resistance. Our finding of lower RBP4 concentrations in black compared to white patients with RA is congruent with an earlier investigation that showed disparities in RBP4 gene polymorphisms amongst black and white Americans.