scholarly journals Complex Membrane Channel Blockade: A Unifying Hypothesis for the Prodromal and Acute Neuropsychiatric Sequelae Resulting from Exposure to the Antimalarial Drug Mefloquine

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Jane C. Quinn
Keyword(s):  
Parent Compound ◽  
Quinoline Derivative ◽  
Channel Blockade ◽  
Membrane Channel ◽  
Complex Membrane ◽  
Life Threatening ◽  
Resistant Strains ◽  
Synthetic Derivatives ◽  
Kinetics Of ◽  
Neuropsychiatric Side Effects

The alkaloid toxin quinine and its derivative compounds have been used for many centuries as effective medications for the prevention and treatment of malaria. More recently, synthetic derivatives, such as the quinoline derivative mefloquine (bis(trifluoromethyl)-(2-piperidyl)-4-quinolinemethanol), have been widely used to combat disease caused by chloroquine-resistant strains of the malaria parasite,Plasmodium falciparum. However, the parent compound quinine, as well as its more recent counterparts, suffers from an incidence of adverse neuropsychiatric side effects ranging from mild mood disturbances and anxiety to hallucinations, seizures, and psychosis. This review considers how the pharmacology, cellular neurobiology, and membrane channel kinetics of mefloquine could lead to the significant and sometimes life-threatening neurotoxicity associated with mefloquine exposure. A key role for mefloquine blockade of ATP-sensitive potassium channels and connexins in the substantia nigra is considered as a unifying hypothesis for the pathogenesis of severe neuropsychiatric events after mefloquine exposure in humans.

scholarly journals Antibiotic Resistance Profile and Biofilm Production of Staphylococcus pseudintermedius Isolated from Dogs in Thailand

2021 ◽  
Vol 14 (6) ◽  
pp. 592
Author(s):  
Pavarish Jantorn ◽  
Hawaree Heemmamad ◽  
Tanawan Soimala ◽  
Saowakon Indoung ◽  
Jongkon Saising ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Meca Gene ◽  
Staphylococcus Pseudintermedius ◽  
Methicillin Resistant ◽  
Antibiotic Resistance Profile ◽  
Biofilm Production ◽  
Southern Thailand ◽  
Life Threatening ◽  
Suitable Treatment ◽  
Resistant Strains

Staphylococcus pseudintermedius is a zoonotic pathogen that can cause life-threatening infections in animals and humans. The study of methicillin-resistant S. pseudintermedius (MRSP) and its ability to produce biofilms is important to select the most suitable treatment. The prevalence and characteristics of S. pseudintermedius isolated from dogs admitted at the Veterinary Teaching Hospital, Prince of Songkla University, Thailand were assessed. Results showed that 28.30% (15/53) of the isolates were MRSP. Amplification of the mecA gene was observed in 93.33% (14/15) MRSP. Methicillin-resistant strains revealed co-resistant patterns against other antibiotics, including chloramphenicol, clindamycin, tetracycline, clarithromycin, ciprofloxacin, and trimethoprim. In this study, all bacterial isolates produced biofilms, while 90.55% of S. pseudintermedius isolates were strong or moderate biofilm producers. Most (45–60%) of the resistant strains were strong biofilm producers, while the correlation between biofilm production and antibiotic resistance was not statistically significant. This is the first study in southern Thailand to investigate the drug-resistant profile of S. pseudintermedius and its ability to form biofilm. The results will contribute to a better understanding of the emergence and prevalence of antimicrobial resistance in S. pseudintermedius.

scholarly journals Chlorine and Chlorinated Compounds Removal from Industrial Wastewater Discharges: A Review

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Mohammad Al-Hwaiti ◽  
Hamidi Abdul Aziz ◽  
Mohd Azmier Ahmad ◽  
Reyad Al-Shawabkeh
Keyword(s):  
Industrial Wastewater ◽  
Electrochemical Techniques ◽  
Parent Compound ◽  
Water Soluble ◽  
Human Beings ◽  
Catalytic Method ◽  
Chlorinated Compounds ◽  
Water Treatment Process ◽  
Chlorine Removal ◽  
Kinetics Of

Adsorption techniques for industrial wastewater treatment rich in heavy metals and aqueous solutions of water-soluble such as Cl−, F−, HCO3−, NO3−, SO2−4, and PO3−, often include technologies for toxicity removals. The recent advancement and technical applicability in the treatment of chlorine and chlorinated compounds from industrial wastewater are reviewed in this article. Chlorine and chlorinated compounds are among the common discharged constituents from numerous industries. They can be carcinogenic or naturally toxic and can pose issues to aquatic ecosystems and human beings. Thus, elimination of chlorides and chlorinated compounds from water or wastewater is inevitable to get rid of the problem. Several techniques are being applied for the reduction of chlorine and chlorinated compounds in water. These include biodegradation, photochemical, adsorption, chemical, electrochemical, photo-electrochemical, membrane, supercritical extraction and catalytic method. Chlorine can react with various organic and inorganic micro-pollutants. However, the potential reactivity of chlorine for specific compounds is small, and only minor variations in the structure of the parent compound are anticipated in the water treatment process under typical conditions. This paper reviews different techniques and aspects related to chlorine removal, the types of chlorine species in solution and their catalyst, chlorine fate and transport into the environment, electrochemical techniques for de-chlorination of water, kinetics, mechanisms of reduction of chlorinated compounds, and kinetics of the electrochemical reaction of chlorine compounds. Keywords: Industrial waste, Kinetics, Wastewater, Water purification

scholarly journals Travel-Related Typhoid Fever: Narrative Review of the Scientific Literature

2020 ◽  
Vol 17 (2) ◽  
pp. 615 ◽  
Author(s):  
Narcisa Muresu ◽  
Giovanni Sotgiu ◽  
Bianca Maria Are ◽  
Andrea Cossu ◽  
Clementina Cocuzza ◽  
...  
Keyword(s):  
Low Income ◽  
Delayed Diagnosis ◽  
Low Income Countries ◽  
Travel Health ◽  
High Incidence ◽  
Health Advice ◽  
Life Threatening ◽  
Risk Of Disease ◽  
Resistant Strains ◽  
Drug Resistant Strains

Enteric fever is a foodborne infectious disease caused by Salmonella enterica serotypes Typhi and Paratyphi A, B and C. The high incidence in low income countries can increase the risk of disease in travelers coming from high income countries. Pre-travel health advice on hygiene and sanitation practices and vaccines can significantly reduce the risk of acquiring infections. Although the majority of the cases are self-limiting, life-threatening complications can occur. Delayed diagnosis and cases of infections caused by multi-drug resistant strains can complicate the clinical management and affect the prognosis. More international efforts are needed to reduce the burden of disease in low income countries, indirectly reducing the risk of travelers in endemic settings. Surveillance activities can help monitor the epidemiology of cases caused by drug-susceptible and resistant strains.

Kinetics of benzo(a)pyrene and 3-hydroxybenzo(a)pyrene in relation to DNA adducts formation in rat tissues following intravenous administration of the parent compound

2009 ◽  
Vol 189 ◽  
pp. S159
Author(s):  
Caroline Marie ◽  
Michèle Bouchard ◽  
Ross Thuot ◽  
Jean-Luc Ravanat ◽  
Anne Maître ◽  
...  
Keyword(s):  
Dna Adducts ◽  
Intravenous Administration ◽  
Parent Compound ◽  
Rat Tissues ◽  
Kinetics Of

scholarly journals Antipneumococcal Activity of ABT-773 Compared to Those of 10 Other Agents

2000 ◽  
Vol 44 (7) ◽  
pp. 1894-1899 ◽  
Author(s):  
Todd A. Davies ◽  
Lois M. Ednie ◽  
Dianne M. Hoellman ◽  
Glenn A. Pankuch ◽  
Michael R. Jacobs ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Vitro Activity ◽  
Penicillin Resistance ◽  
Penicillin G ◽  
23S Rrna ◽  
In Vitro Activity ◽  
Resistant Strains ◽  
Domain V ◽  
Kinetics Of

ABSTRACT MICs, time-kills, and postantibiotic effects (PAEs) of ABT-773 (a new ketolide) and 10 other agents were determined against 226 pneumococci. Against 78 ermB- and 44mefE-containing strains, ABT-773 MICs at which 50% of the isolates tested were inhibited (MIC50s) and MIC90s were 0.016 to 0.03 and 0.125 μg/ml, respectively. Clindamycin was active only against macrolide-resistant strains containing mefE (MIC50, 0.06 μg/ml; MIC90, 0.125 μg/ml). Activities of pristinamycin (MIC90, 0.5 μg/ml) and vancomycin (MIC90, 0.25 μg/ml) were unaffected by macrolide or penicillin resistance, while β-lactam MICs rose with those of penicillin G. Against 19 strains with L4 ribosomal protein mutations and two strains with mutations in domain V of 23S rRNA, ABT-773 MICs were 0.03 to 0.25 μg/ml, while macrolide and azalide MICs were all ≥16.0 μg/ml. ABT-773 was bactericidal at twice the MIC after 24 h for 8 of 12 strains (including three strains with erythromycin MICs greater than or equal to 64.0 μg/ml). Kill kinetics of erythromycin, azithromycin, clarithromycin, and roxithromycin against macrolide-susceptible strains were slower than those of ABT-773. ABT-773 had longer PAEs than macrolides, azithromycin, clindamycin, or β-lactams, including against ermB-containing strains. ABT-773, therefore, shows promising in vitro activity against macrolide-susceptible as well as -resistant pneumococci.

scholarly journals EFFLUX PUMP OVEREXPRESSION PROFILING IN ACINETOBACTER BAUMANNII AND STUDY OF NEW 1-(1-NAPHTHYLMETHYL)-PIPERAZINE ANALOGS AS POTENTIAL EFFLUX INHIBITORS

2021 ◽  
Author(s):  
Morgane Choquet ◽  
Elodie Lohou ◽  
Etienne Pair ◽  
Pascal Sonnet ◽  
Catherine Mullie
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Inhibitory Activity ◽  
Efflux Pump ◽  
Parent Compound ◽  
Efflux Pumps ◽  
Quinoline Derivative ◽  
Genes Encoding ◽  
Efflux Pump Inhibitors ◽  
Therapeutic Alternatives

Overexpression of efflux pumps extruding antibiotics currently used for the treatment of Acinetobacter baumannii infections has been described as an important mechanism causing antibiotic resistance. The first aim of this work was to phenotypically evaluate the overexpression of efflux pumps on a collection of 124 ciprofloxacin resistant A. baumannii strains. An overexpression of genes encoding one or more efflux pumps was obtained for 19 out of the 34 strains with a positive phenotypic efflux (56%). The most frequent genes overexpressed were those belonging to the RND family, with adeJ being the most prevalent (50%). Interestingly, efflux pump genes coding for MATE and MFS families were also overexpressed quite frequently: abeM (32%) and abaQ (26%). The second aim was to synthesize 1-(1-NaphthylMethyl)-Piperazine analogs as potential new efflux pump inhibitors and biologically evaluate them against strains with a positive phenotypic efflux. Quinoline and pyridine analogs were found to be more effective than their parent compound 1-(1-NaphthylMethyl)-Piperazine. Stereochemistry also played an important part in the inhibitory activity as quinoline derivative ( R )-3a was identified as being the most effective and less cytotoxic. Its inhibitory activity was also correlated to the number of efflux pumps expressed by a strain. The results obtained in this work suggest that quinoline analogs of 1-(1-NaphthylMethyl)-Piperazine are promising leads in the development of new anti- Acinetobacter baumannii therapeutic alternatives, in combination with antibiotics for which an efflux-mediated resistance is suspected.

scholarly journals Large Peptide Permeation Through a Membrane Channel: Understanding Protamine Translocation Through CymA from Klebsiella Oxytoca

2020 ◽  
Author(s):  
Sushil Pangeni ◽  
Jigneshkumar Dahyabhai Prajapati ◽  
Jayesh Arun Bafna ◽  
Nilam Mohamed ◽  
Werner M. Nau ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Klebsiella Oxytoca ◽  
Limiting Factor ◽  
Membrane Channel ◽  
Voltage Dependent ◽  
Dynamics Simulations ◽  
Rate Limiting ◽  
Kinetics Of ◽  
Zero Voltage ◽  
Large Peptide

Quantifying the passage of the large peptide protamine (Ptm) across CymA, a passive channel for cyclodextrin uptake, is in the focus of this study. Using a reporter-pair based fluorescence membrane assay we detected the entry of Ptm into liposomes containing CymA. The kinetics of the Ptm entry was independent of its concentration suggesting that the permeation across CymA is the rate-limiting factor. Furthermore, we reconstituted single CymA channels into planar lipid bilayers and recorded the ion current fluctuations in the presence of Ptm. To this end, we were able to resolve the voltage-dependent entry of single Ptm peptide molecules into the channel. Extrapolation to zero voltage revealed about 1-2 events per second and long dwell times, in agreement with the liposome study. Applied-field and steered molecular dynamics simulations provided an atomistic view on the permeation. It can be concluded that a concentration gradient of 1 M Ptm leads to a translocation rate of about 1 molecule per second and per channel.

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