scholarly journals H2S mediates interbacterial communication through the air reverting intrinsic antibiotic resistance

2017 ◽  
Author(s):  
Daniel Thomas-Lopez ◽  
Laura Carrilero ◽  
Stephanie Matrat ◽  
Natalia Montero ◽  
Stéphane Claverol ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Orthologous Genes ◽  
Multiresistant Pathogens ◽  
Extracellular Release ◽  
Significant Step ◽  
Life Threatening ◽  
Cephalosporin Resistance ◽  
The Media ◽  
Niche Competition ◽  
Therapeutic Alternatives

AbstractHydrogen sulfide, a gas classically considered as a by-product of cellular metabolism, is today recognized as a crucial gasotransmitter in Eukaryotes. Moreover, most bacteria harbor the eukaryotic orthologous genes for H2S synthesis, and these genes have been linked to different metabolic pathways.Some bacteria, however, produce high amounts of H2S in their extracellular space, a characteristic classically used for identification purposes. This is the case ofSalmonellaTyphimurium, which produces H2S by itsphsABCoperon. Here we show that extracellular release of H2S byS. Typhimurium is solely dependent on itsphsABCoperon. Furthermore, we show thatS. Typhimurium and other H2S-producing bacteria can interact with physically distant bacteria through H2S production. We demonstrate how H2S can revert intrinsic cephalosporin resistance ofEnterococccus faecalisandEnterococcus faeciumto complete susceptibility. This study constitutes a significant step in the study of bacterial interplay and niche competition. Furthermore, as H2S releasing drugs have already been designed, our results open the way to future therapeutic alternatives for the treatment of infections caused by enterococci, multiresistant pathogens for which no treatments are clinically available.Author SummaryIt has been known for decades that bacteria can communicate with each other through the diffusion of metabolites in the media. However, the capacity of a bacterium to interact with other physically distant cell is a recent discovery of the 21stcentury. In this work we show how some well-studied bacteria, as it isSalmonellaspp., interacts with other bacteria thanks to the compound hydrogen sulfide (H2S) that they produce and release to the environment.In our study we have designed novel techniques that allow us to study the interaction between two bacteria, and we have seen thatSalmonellais able to affect other species that is even 1 cm away,i.e., a distance corresponding to 10.0000 times its own size.What is more astonishing is thatEnterococcus, when exposed to the H2S, is dramatically becomes susceptible to many antibiotics, to which it is supposed to be naturally resistant.Enterococcusspp. are responsible for life-threatening infections in hospitals worldwide. Thus, our observations reveal that bacteria can communicate through the air with H2S, and that this molecule can make bacteria that are highly resistant to antibiotics susceptible to antibiotics, making untreatable infections treatable with current antibiotics.

Region-Specific Medial Fiber Micro-Architecture in the Longitudinal-Radial and Circumferential-Radial Planes of Ascending Thoracic Aortic Aneurysm Among Bicuspid and Tricuspid Aortic Valve Patients

2013 ◽  
Author(s):  
Alkiviadis Tsamis ◽  
Julie A. Phillippi ◽  
Ryan G. Koch ◽  
Jeffrey T. Krawiec ◽  
Antonio D’Amore ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Aortic Valve ◽  
Aortic Aneurysm ◽  
Thoracic Aortic Aneurysm ◽  
Aortic Wall ◽  
False Lumen ◽  
True Lumen ◽  
Life Threatening ◽  
The Media ◽  
Intimal Tear

Aortic dissection is a life-threatening cardiovascular emergency with a high potential for death. It usually begins with an intimal tear which permits blood to enter the wall, split the media and create a false lumen, which can reenter the true lumen or exit through the adventitia causing complete rupture. A possible mechanism for dissection of ascending thoracic aortic aneurysm (ATAA) can be the occurrence of blood pressure-induced wall stresses in excess to the adhesive strength between the degenerated aortic wall layers.

scholarly journals Methylene Blue Administration During and After Life-Threatening Intoxication by Hydrogen Sulfide: Efficacy Studies in Adult Sheep and Mechanisms of Action

2018 ◽  
Vol 168 (2) ◽  
pp. 443-459 ◽  
Author(s):  
Philippe Haouzi ◽  
Nicole Tubbs ◽  
Joseph Cheung ◽  
Annick Judenherc-Haouzi
Keyword(s):  
Methylene Blue ◽  
Hydrogen Sulfide ◽  
Time Course ◽  
Cardiac Contractility ◽  
Pulseless Electrical Activity ◽  
Left Ventricular ◽  
Direct Oxidation ◽  
Adult Sheep ◽  
Cardiac Depression ◽  
Life Threatening

Abstract Exposure to toxic levels of hydrogen sulfide (H2S) produces an acute cardiac depression that can be rapidly fatal. We sought to characterize the time course of the cardiac effects produced by the toxicity of H2S in sheep, a human sized mammal, and to describe the in vivo and in vitro antidotal properties of methylene blue (MB), which has shown efficacy in sulfide intoxicated rats. Infusing NaHS (720 mg) in anesthetized adult sheep produced a rapid dilation of the left ventricular with a decrease in contractility, which was lethal within about 10 min by pulseless electrical activity. MB (7 mg/kg), administered during sulfide exposure, maintained cardiac contractility and allowed all of the treated animals to recover. At a dose of 350 mg NaHS, we were able to produce an intoxication, which led to a persistent decrease in ventricular function for at least 1 h in nontreated animals. Administration of MB, 3 or 30 min after the end of exposure, whereas all free H2S had already vanished, restored cardiac contractility and the pyruvate/lactate (P/L) ratio. We found that MB exerts its antidotal effects through at least 4 different mechanisms: (1) a direct oxidation of free sulfide; (2) an increase in the pool of “trapped” H2S in red cells; (3) a restoration of the mitochondrial substrate-level phosphorylation; and (4) a rescue of the mitochondrial electron chain. In conclusion, H2S intoxication produces acute and long persisting alteration in cardiac function in large mammals even after all free H2S has vanished. MB exerts its antidotal effects against life-threatening sulfide intoxication via multifarious properties, some of them unrelated to any direct interaction with free H2S.

Challenging the Media-Incarceration Complex through Media Education

2017 ◽  
Author(s):  
Bill Yousman
Keyword(s):  
Mass Media ◽  
The United States ◽  
Crime Rates ◽  
Media Representations ◽  
Media Education ◽  
Prime Time ◽  
Crisis Of Representation ◽  
Life Threatening ◽  
The Media ◽  
Popular Television

This chapter argues that the United States faces a crisis of representation, for while crime rates remain stable, the TV and other corporate-controlled mass media bury viewers beneath an avalanche of fear-based spectacles in which crime and violence are portrayed as escalating, even life-threatening crises. It then outlines a new program of media education that enables consumers of mass media to develop more informed and empowering views of the complexities of crime and violence. Focusing on prime-time dramatic television as the most prevalent source of fictional images of violence, crime, and incarceration, the chapter addresses the distorted narratives and images that saturate popular television dramas. Drawing upon interviews with ex-prisoners, it also shows how media representations of imprisonment, though inaccurate and misleading, shape the perceptions even of those who have themselves been incarcerated.

Automated Detection of Hydrogen Sulfide Release from Thiosulfate by Salmonella spp.

1998 ◽  
Vol 61 (5) ◽  
pp. 620-622 ◽  
Author(s):  
LEORA A. SHELEF ◽  
WEI TAN
Keyword(s):  
Hydrogen Sulfide ◽  
Ammonium Citrate ◽  
Ferric Ammonium Citrate ◽  
Decarboxylase Activity ◽  
Salmonella Spp ◽  
Sharp Drop ◽  
Conventional Tests ◽  
Ferric Ammonium ◽  
The Media ◽  
Agar Media

Hydrogen sulfide production is used in conventional tests for identification and differentiation of Salmonella spp. from other species of Enterobacteriaceae, and a black precipitate on agar media is the indicator of the reaction. Selective liquid media were formulated for automated optical detection of H2S in salmonellae using the BioSys instrument. The media contained thiosulfate and ferric ammonium citrate, and production of H2S caused copious black pigmentation of the broth. Combination of the H2S indicators with dulcitol or xylose as fermentable carbohydrate, lysine, omithine or arginine to induce decarboxylase activity, and Tergitol 4 as inhibitor selectively identified six Salmonella spp. by a sharp drop in transmittance at 585 nm. The time for detection of transmittance changes was inversely proportional to initial numbers of CFU in the media: 10 h for 105 CFU/ml and 17 h for 101 CFU/ml. No detection was observed in six non-Salmonella species of Enterobacteriaceae tested.

scholarly journals CandidaInfections, Causes, Targets, and Resistance Mechanisms: Traditional and Alternative Antifungal Agents

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Claudia Spampinato ◽  
Darío Leonardi
Keyword(s):  
Antifungal Agents ◽  
Fungal Infections ◽  
Current Knowledge ◽  
Resistance Mechanisms ◽  
Antifungal Drugs ◽  
Diagnostic Methods ◽  
Opportunistic Pathogens ◽  
Yeast Infection ◽  
Life Threatening ◽  
Therapeutic Alternatives

The genusCandidaincludes about 200 different species, but only a few species are human opportunistic pathogens and cause infections when the host becomes debilitated or immunocompromised.Candidainfections can be superficial or invasive. Superficial infections often affect the skin or mucous membranes and can be treated successfully with topical antifungal drugs. However, invasive fungal infections are often life-threatening, probably due to inefficient diagnostic methods and inappropriate initial antifungal therapies. Here, we briefly review our current knowledge of pathogenic species of the genusCandidaand yeast infection causes and then focus on current antifungal drugs and resistance mechanisms. An overview of new therapeutic alternatives for the treatment ofCandidainfections is also provided.

Fracture Mechanisms in Bovine Aorta

2010 ◽  
Author(s):  
Henry W. Haslach ◽  
Jonathan Chung ◽  
Aviva Molotsky
Keyword(s):  
Collagen Fiber ◽  
Vascular Tissue ◽  
Circulatory System ◽  
Fracture Mechanisms ◽  
Load Carrying ◽  
Life Threatening ◽  
Homogeneous Matrix ◽  
The Media ◽  
Artery Tissue ◽  
Ground Material

Rupture of vascular tissue in the circulatory system under non-impact loading is involved in potentially life threatening events such as Marfan’s syndrome or rupture of small renal veins during shock wave lithotripsy. The rupture mechanisms are not well-understood. The complexity of the artery wall precludes the use of rupture theories invented for metals or for fibered composites with a homogeneous matrix. Artery tissue is composed of ground material, smooth muscle cells, elastin and collagen. The collagen fibers, which are generally circumferentially oriented, are the load carrying material after large deformations. Clark and Glagov [1] propose that the media of an elastic artery is built of musculo-elastic fascicles made up of a layer of circumferentially oriented SMC that lie parallel and between two elastin lamellae. Between the elastin sheets of adjacent elements are interspersed collagen fiber bundles.

scholarly journals First observation of neutrophil extracellular traps in human leptospirosis

2017 ◽  
Vol 4 (4) ◽  
pp. 10 ◽  
Author(s):  
Emilia Scharrig ◽  
Ricardo Drut ◽  
Ricardo Martin Gomez
Keyword(s):  
Nuclear Dna ◽  
Febrile Illness ◽  
Neutrophil Extracellular Traps ◽  
Pulmonary Involvement ◽  
Human Leptospirosis ◽  
Extracellular Traps ◽  
Extracellular Release ◽  
Human Pathology ◽  
Life Threatening ◽  
First Time

Leptospirosis is the most important global zoonosis and is caused by pathogenic spirochetes of the genus Leptospira. Human leptospirosis ranges in severity from a mild, self-limited febrile illness to a fulminant life-threatening one but their pathogenesis is still unclear. The extracellular release of the nuclear DNA of neutrophils, called NETs, upon activation by microbes is a pathogen-killing mechanism of neutrophils described in 2004 although its presence in human pathology have been observed only very recently.We report a case of fatal fulminant leptospirosis with associated severe pulmonary involvement and shown for the first time, evidence of the presence of NETs in the lung tissue.

Case report of treatment resistant schizophreniaresponding to high dose quetiapine following clozapine withdrawal due to neutropenia

2011 ◽  
Vol 26 (S2) ◽  
pp. 1359-1359
Author(s):  
P. Chandrappa ◽  
L. Ho
Keyword(s):  
Side Effects ◽  
Therapeutic Response ◽  
Significant Proportion ◽  
High Dose ◽  
Treatment Resistant ◽  
Maximum Daily Dose ◽  
Daily Dose ◽  
Life Threatening ◽  
Therapeutic Alternatives ◽  
Clozapine Withdrawal

IntroductionPatients suffering from treatment-resistant schizophrenia pose a difficult therapeutic challenge. Although Clozapine is a well-established treatment in such cases, there is a significant proportion of patients who have to discontinue Clozapine due to life-threatening side-effects, despite achieving good therapeutic response. There is very limited literature on the therapeutic alternatives to Clozapine in the treatment of resistant schizophrenia.ObjectiveTo report a case of resistant schizophrenia responding to high dose Quetiapine, following discontinuation of Clozapine due to neutropenia.Clinical details of the case: We are presenting a case of a forty-two year old female patient with treatment resistant schizophrenia who achieved remission following treatment with Clozapine, but had to discontinue treatment due to neutropenia, which occurred on two occasions. Clozapine discontinuation resulted in rapid and severe relapse in her condition and re-admission to hospital. Quetiapine was initiated as this stage, but only partial improvement was noted at the manufacturer's stated maximum daily dose of 800 mg/day. Since the drug was being well tolerated the dose was gradually further increased.ResultsThe dose of Quetiapine was eventually increased up to 1400 mg/day, which produced significant response and the patient was discharged from hospital. Quetiapine at this dose was well tolerated with minimal side effects.ConclusionThe above report indicates that high-dose Quetiapine is a viable alternative to Clozapine in treating refractory schizophrenia. The findings from this report support further investigation of this approach in the form of larger scale clinical trials.

scholarly journals A "Meaningful" Seat at the Table: Contemplating Our Ongoing Struggle to Access Democracy

2020 ◽  
Vol 73 (1) ◽  
pp. 35-50 ◽  
Author(s):  
James M. Binnall
Keyword(s):  
Criminal History ◽  
Logical Foundation ◽  
Significant Step ◽  
Recent Reform ◽  
The Media ◽  
Voter Disenfranchisement

In recent years, felon-voter disenfranchisement has received considerable attention from academics, policymakers, and the media. In turn, a number of jurisdictions have eased record-based voter restriction statutes. And while those efforts represent a significant step toward full civic reintegration for those with a felony criminal history, they are far from comprehensive, as they regularly omit citizens with certain types of felony convictions and typically address only one form of civic marginalization. Focusing on recent reform in the area of civic restrictions, this Article suggests that incomplete civic restoration comes with significant consequences that ought to be considered during legislative negotiations. This Article further suggests that by capitulating to emotive, non-empirical opposition to full civic reinstatement, lawmakers run the risk of validating arguments that have no scientific or logical foundation.

scholarly journals Evaluation of awareness level of Taliqan residents about the health hazard of environmental pollution

2020 ◽  
Vol 3 (1) ◽  
pp. 10-14
Author(s):  
Nazar Mohammad Wahaj ◽  
Mohammad Hassan Abidi
Keyword(s):  
Environmental Pollution ◽  
Health Hazard ◽  
Health Hazards ◽  
The Road ◽  
Waste Storage ◽  
Life Threatening ◽  
The Media ◽  
On The Road ◽  
The City ◽  
Awareness Level

Protecting the environment is one of the most important responsibilities for every human being to keep it clean and protected. The pollutant and contaminated environment will cause many life-threatening diseases. It is well known that humans’ activities are the main causes of environmental pollution, therefore this research is aimed to evaluate the awareness level of Taliqan residents about the health hazards and environmental pollutions. The method used in this study was descriptive analytics and the data was collected through the questionnaires distributed to the townspeople and their responses were recorded. The results of this study showed that among 540 participants, 45.1% have fully awareness about the type of pollution and its health hazards, 25.74% have good knowledge, 14% have medal awareness, 11.85% have low awareness, 3.14% did not have any unaware. Also, none of the participants did not report daily activities of the municipality regarding management and cleanup of the city, while 1.85% reported the weekly activities, 20% monthly activities, 49.62% confirmed the non- program activities, and 19.44% were unaware of the city’s cleanup process by municipal authorities’ responsible persons. This study concludes that poor management of municipal officials, lack of waste containers on the road sides and amusement parks are the main reasons behind the waste storage and aggregation of rubbish in every corner of the city. In addition, lack of effective environmental education programs through the media has made the culture of urbanization and environmental protection less institutionalized among citizens.

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