Search results for "PORIN"

Fatal Anaphylactic Shock Ceftriaxone-Induced in a 4-Year-Old Child

2014

One of the most used cephalosporin in clinical practice is ceftriaxone. Anaphylaxis due to the administration of ceftriaxone is considered a rare event. Here, we report a case of fatal anaphylactic shock after the administration of ceftriaxone in a child who had tolerated the drug in past exposures. The allergic pathogenesis is sustained by the clinical data (short time between the inoculation of the drug and the onset of the symptoms; past exposure to the same molecule and probable sensitization) and the postmortem examination findings (polivisceral congestion and intense eosinophilia found in the histological examination).

Drug‐refractory myasthenia gravis: Clinical characteristics, treatments, and outcome

2022

[Objective] To describe the clinical characteristics and outcomes in patients with refractory myasthenia gravis (MG) and to determine the effectiveness and side effects of the drugs used for their treatment.

Influence of Haemophilus influenzae β-lactamase production and/or ftsI gene mutations on in vitro activity of and susceptibility rates to aminopenici…

2007

Multidrug and broad-spectrum cephalosporin resistance among Salmonella enterica serotype enteritidis clinical isolates in southern Italy.

2002

ABSTRACT From 1992 to 1997, only six sporadic isolates of Salmonella enterica serotype Enteritidis from patients with cases of gastroenteritis in southern Italy exhibited resistance to broad-spectrum cephalosporins. Five isolates produced SHV-12, and one isolate encoded a class C β-lactamase. The bla SHV-12 gene was located in at least two different self-transferable plasmids, one of which also carried a novel class 1 integron.

The liquid state of FG-nucleoporins mimics permeability barrier properties of nuclear pore complexes

2019

Nuclear pore complexes form a permeability barrier in vivo that regulates nucleocytoplasmic transport. Here, the authors present a microfluidic device that couples rapid liquid–liquid phase separation of nucleoporins with direct optical interrogation. Freshly formed liquid nucleoporin droplets mimic permeability barrier properties of NPCs.

Electrical Pumping of Potassium Ions Against an External Concentration Gradient in a Biological Ion Channel

2013

We show experimentally and theoretically that significant currents can be obtained with a biological ion channel, the OmpF porin of Escherichia coli, using zero-average potentials as driving forces. The channel rectifying properties can be used to pump potassium ions against an external concentration gradient under asymmetric pH conditions. The results are discussed in terms of the ionic selectivity and rectification ratio of the channel. The physical concepts involved may be applied to separation processes with synthetic nanopores and to bioelectrical phenomena. (C) 2013 AIP Publishing LLC.

Prediction and Interpretation of Some Pharmacological Properties of Cephalosporins Using Molecular Connectivity

1991

A method of molecular connectivity was used to study the pharmacological and antimicrobial properties of 34 cephalosporin antibiotics to verify its applicability to these parameters. By using Kier and Hall connectivity indices (Xi) as well as geometric indices (GIs), good correlation equations were obtained with a low number of variables. In some cases, such as the lethal dose for 50% of group (LD50) values and minimum inhibitory concentration (MIC) values for Pseudomonas aeruginosa, better regression equations were obtained with the GIs alone, confirming their alternative nature with respect to Xi, indices.

Membrane Integration of Poliovirus 2B Viroporin

2011

Virus infections can result in a variety of cellular injuries, and these often involve the permeabilization of host membranes by viral proteins of the viroporin family. Prototypical viroporin 2B is responsible for the alterations in host cell membrane permeability that take place in enterovirus-infected cells. 2B protein can be localized at the endoplasmic reticulum (ER) and the Golgi complex, inducing membrane remodeling and the blockade of glycoprotein trafficking. These findings suggest that 2B has the potential to integrate into the ER membrane, but specific information regarding its biogenesis and mechanism of membrane insertion is lacking. Here, we report experimental results of in vi…

Active surfaces engineered by immobilizing protein-polymer nanoreactors for selectively detecting sugar alcohols.

2016

We introduce active surfaces generated by immobilizing protein-polymer nanoreactors on a solid support for sensitive sugar alcohols detection. First, such selective nanoreactors were engineered in solution by simultaneous encapsulation of specific enzymes in copolymer polymersomes, and insertion of membrane proteins for selective conduct of sugar alcohols. Despite the artificial surroundings, and the thickness of the copolymer membrane, functionality of reconstituted Escherichia coli glycerol facilitator (GlpF) was preserved, and allowed selective diffusion of sugar alcohols to the inner cavity of the polymersome, where encapsulated ribitol dehydrogenase (RDH) enzymes served as biosensing e…

Folding and stability of the aquaglyceroporin GlpF: Implications for human aqua(glycero)porin diseases

2015

AbstractAquaporins are highly selective polytopic transmembrane channel proteins that facilitate the permeation of water across cellular membranes in a large diversity of organisms. Defects in aquaporin function are associated with common diseases, such as nephrogenic diabetes insipidus, congenital cataract and certain types of cancer. In general, aquaporins have a highly conserved structure; from prokaryotes to humans. The conserved structure, together with structural dynamics and the structural framework for substrate selectivity is discussed. The folding pathway of aquaporins has been a topic of several studies in recent years. These studies revealed that a conserved protein structure ca…