103 research outputs found
Use of HDFx, a Novel Immunomodulator, to Stop the Germs from Winning in Hospitals and on The Battlefields : The Dangers of Antibiotic Resistance
Getting admitted to a civilian or battlefield hospital these days often poses considerable risks and dangers. The ever-growing number of emerging diseases worldwide makes treatment of patients difficult and sometimes impossible. Many antibiotics are no longer effective against the simplest infections, which result in further hospitalizations with increased costs to the patients and governments worldwide. Microorganisms of prime concern include methicillin-resistant Staphylococcus aureus, Clostridium difficile, multidrug and extensive drug-resistant Mycobacterium tuberculosis, Neisseria gonorrhoeae, and carbapenem- resistant Enterobacteriaceae, as well as bacteria that produce extensive spectram beta-lactamases, such as E. coli. An unusual decline in the discovery of new and effective antibiotics, these days, is only making matters worse
Synthetic Vasopressin and Oxytocin Analogs and Their Potential Use in Hemorrhagic, Traumatic and Septic Shock: A Personal Perspective
As one of us has stated many years ago, “shock is a significant and sustained loss of effective circulating blood volume. It will eventuate in hypoperfusion of critical peripheral tissues, thus leading to a deficit in transcapillary exchange function in critical organ regions. Clinically, there are five major types of circulatory shock: cardiogenic; septic; distributive; anaphylactic; and hypovolemic. Hypovolemic shock (HS) is, primarily, due to a marked decrease in venous return, falling arterial blood pressure, and ventricular preload, and usually is caused by hemorrhage, dehydration, excessive diarrhea, trauma, excessive fluid loss from severe burns, increased positive intrathoracic pressure, excessive urinary fluid loss resulting from diuretics, side effects of many chemotherapeutic agents and radiation in cancer patients, or depressed vasomotor tone in the microcirculatio
Insights into the Possible Mechanisms By Which Platelet-Activating Factor and PAF-receptors Function in Vascular Smooth Muscle in Magnesium Deficiency and Vascular Remodeling: Possible Links to Atherogenesis, Hypertension and Cardiac Failure
Platelet-activating factor (PAF) is a phospholipid mediator and cell signaling molecule which displays multiple biological and pathophysiological attributes, running the gamut from inflammation to cell differentiation and proliferation [1-4]. As is well-known, PAF interacts with specific membrane PAF-receptors (PAF-Rs) to initiate all cellular responses via specific G-proteincoupled receptors [1-4]. Although these initiated membrane receptor phenomena are mostly established for several tissuecell systems [1-8], exactly how PAF and PAF-Rs cause vascular remodeling in hypertension and atherosclerosis is not clear. A little more than 15 years ago, PAF was identified as a molecule that stimulated activation of nuclear factor-kappaB (NF-kB
Perivascular Expression and Potent Vasoconstrictor Effect of Dynorphin A in Cerebral Arteries
BACKGROUND: Numerous literary data indicate that dynorphin A (DYN-A) has a significant impact on cerebral circulation, especially under pathophysiological conditions, but its potential direct influence on the tone of cerebral vessels is obscure. The aim of the present study was threefold: 1) to clarify if DYN-A is present in cerebral vessels, 2) to determine if it exerts any direct effect on cerebrovascular tone, and if so, 3) to analyze the role of κ-opiate receptors in mediating the effect. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistochemical analysis revealed the expression of DYN-A in perivascular nerves of rat pial arteries as well as in both rat and human intraparenchymal vessels of the cerebral cortex. In isolated rat basilar and middle cerebral arteries (BAs and MCAs) DYN-A (1-13) and DYN-A (1-17) but not DYN-A (1-8) or dynorphin B (DYN-B) induced strong vasoconstriction in micromolar concentrations. The maximal effects, compared to a reference contraction induced by 124 mM K(+), were 115±6% and 104±10% in BAs and 113±3% and 125±9% in MCAs for 10 µM of DYN-A (1-13) and DYN-A (1-17), respectively. The vasoconstrictor effects of DYN-A (1-13) could be inhibited but not abolished by both the κ-opiate receptor antagonist nor-Binaltorphimine dihydrochloride (NORBI) and blockade of G(i/o)-protein mediated signaling by pertussis toxin. Finally, des-Tyr(1) DYN-A (2-13), which reportedly fails to activate κ-opiate receptors, induced vasoconstriction of 45±11% in BAs and 50±5% in MCAs at 10 µM, which effects were resistant to NORBI. CONCLUSION/SIGNIFICANCE: DYN-A is present in rat and human cerebral perivascular nerves and induces sustained contraction of rat cerebral arteries. This vasoconstrictor effect is only partly mediated by κ-opiate receptors and heterotrimeric G(i/o)-proteins. To our knowledge our present findings are the first to indicate that DYN-A has a direct cerebral vasoconstrictor effect and that a dynorphin-induced vascular action may be, at least in part, independent of κ-opiate receptors
Neuroadaptations in Human Chronic Alcoholics: Dysregulation of the NF-κB System
Anna Ökvist is with Karolinska Institute, Sofia Johansson is with Karolinska Institute, Alexander Kuzmin is with Karolinska Institute, Igor Bazov is with Karolinska Institute, Roxana Merino-Martinez is with Karolinska Institute, Igor Ponomarev is with UT Austin, R. Dayne Mayfield is with UT Austin, R. Adron Harris is with UT Austin, Donna Sheedy is with University of Sydney, Therese Garrick is with University of Sydney, Clive Harper is with University of Sydney, Yasmin L. Hurd is with Mount Sinai School of Medicine, Lars Terenius is with Karolinska Institute, Tomas J. Ekström is with Karolinska Institute, Georgy Bakalkin is with Karolinska Institute and Uppsala University, Tatjana Yakovleva is with Karolinska Institute and Uppsala University.Background -- Alcohol dependence and associated cognitive impairments apparently result from neuroadaptations to chronic alcohol consumption involving changes in expression of multiple genes. Here we investigated whether transcription factors of Nuclear Factor-kappaB (NF-κB) family, controlling neuronal plasticity and neurodegeneration, are involved in these adaptations in human chronic alcoholics. Methods and Findings -- Analysis of DNA-binding of NF-κB (p65/p50 heterodimer) and the p50 homodimer as well as NF-κB proteins and mRNAs was performed in postmortem human brain samples from 15 chronic alcoholics and 15 control subjects. The prefrontal cortex involved in alcohol dependence and cognition was analyzed and the motor cortex was studied for comparison. The p50 homodimer was identified as dominant κB binding factor in analyzed tissues. NF-κB and p50 homodimer DNA-binding was downregulated, levels of p65 (RELA) mRNA were attenuated, and the stoichiometry of p65/p50 proteins and respective mRNAs was altered in the prefrontal cortex of alcoholics. Comparison of a number of p50 homodimer/NF-κB target DNA sites, κB elements in 479 genes, down- or upregulated in alcoholics demonstrated that genes with κB elements were generally upregulated in alcoholics. No significant differences between alcoholics and controls were observed in the motor cortex. Conclusions -- We suggest that cycles of alcohol intoxication/withdrawal, which may initially activate NF-κB, when repeated over years downregulate RELA expression and NF-κB and p50 homodimer DNA-binding. Downregulation of the dominant p50 homodimer, a potent inhibitor of gene transcription apparently resulted in derepression of κB regulated genes. Alterations in expression of p50 homodimer/NF-κB regulated genes may contribute to neuroplastic adaptation underlying alcoholism.This work was supported by grants from the AFA Forsäkring to AK, YLH, TJE and GB, the Research Foundation of the Swedish Alcohol Retail Monopoly (SRA) and Karolinska Institutet to AK, TJE and GB, and the Swedish Science Research Council and the Swedish National Drug Policy Coordinator to GB. The Australian Brain Donor Programs NSW Tissue Resource Centre was supported by The University of Sydney, National Health and Medical Research Council of Australia, Neuroscience Institute of Schizophrenia and Allied Disorders, National Institute of Alcohol Abuse and Alcoholism and NSW Department of Health.Waggoner Center for Alcohol and Addiction Researc
Metamorphosis of Subarachnoid Hemorrhage Research: from Delayed Vasospasm to Early Brain Injury
Delayed vasospasm that develops 3–7 days after aneurysmal subarachnoid hemorrhage (SAH) has traditionally been considered the most important determinant of delayed ischemic injury and poor outcome. Consequently, most therapies against delayed ischemic injury are directed towards reducing the incidence of vasospasm. The clinical trials based on this strategy, however, have so far claimed limited success; the incidence of vasospasm is reduced without reduction in delayed ischemic injury or improvement in the long-term outcome. This fact has shifted research interest to the early brain injury (first 72 h) evoked by SAH. In recent years, several pathological mechanisms that activate within minutes after the initial bleed and lead to early brain injury are identified. In addition, it is found that many of these mechanisms evolve with time and participate in the pathogenesis of delayed ischemic injury and poor outcome. Therefore, a therapy or therapies focused on these early mechanisms may not only prevent the early brain injury but may also help reduce the intensity of later developing neurological complications. This manuscript reviews the pathological mechanisms of early brain injury after SAH and summarizes the status of current therapies
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