148 research outputs found
Gender differences in DSM-5 versus DSM-IV-TR PTSD prevalence and criteria comparison among 512 survivors to the L'Aquila earthquake
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Production of the polarized monochromatic relativistic neutron beams and nuclear spectroscopy on high energy accelerators and storage rings
No full textColtsfoot leaves (Tussilago farfara L.) a promising source of essential amino acids
No full textObjective: Free and bounded amino acids are one of the valuable biologically active substances (BAS) containing in medicinal plants with other BAS groups. The research aims to determine the profile and content of free and bounded amino acids in coltsfoot leaves infusion by HPLC-UV, as well as suggest alternative ways to use it in medicine. Materials and methods: Coltsfoot leaves (crushed herbal drug) were used as plant material for preparing infusion and analysis. Amino acids profile and content were analyzed by RP-HPLC-UV after pre-column derivatization with o-phthalaldehyde and 3-mercaptopropionic acid (OPA) (derivatization of primary amines) and with fluorenylmethyloxycarbonyl (FMOC) (secondary amines). The sources of scientific literature concerning the amino acid composition of crushed herbal drugs were also studied. Results: 10 free and 13 bounded amino acids were identified in coltsfoot leaves infusion. Total content was 44.04±2.20 mg/g (Arg > Tyr > Gln > Ala > Asn > Met > Ile > Val > Lys > Leu) and 57.79±2.89 mg/g (Arg > Gln > Lys > Tyr > Gly > Asn > Val > Thr > Ala > Ile > Nva > Leu > Met) respectively. Content of essential amino acids - 0,89±0,04 mg/g (5 free); 9,58±0,48 mg/g (5 bounded). Conclusions: Since the coltsfoot leaves contain a significant amount of arginine, studies involving the prevention and adjunctive treatment of viral diseases, including SARS-CoV-2 virus infection (COVID-19), are promising
Production of the Polarized Monochromatic Relativistic Neutron Beams and Nuclear Spectroscopy on High Energy Accelerators and Storage Rings
No full textAltered antibiotic transport in OmpC mutants isolated from a series of clinical strains of multi-drug resistant E. coli
No full textThis work is also partially supported by BBSRC and the Scottish Funding Council (through SULSA)Antibiotic-resistant bacteria, particularly Gram negative species, present significant health care challenges. The permeation of antibiotics through the outer membrane is largely effected by the porin superfamily, changes in which contribute to antibiotic resistance. A series of antibiotic resistant E. coli isolates were obtained from a patient during serial treatment with various antibiotics. The sequence of OmpC changed at three positions during treatment giving rise to a total of four OmpC variants (denoted OmpC20, OmpC26, OmpC28 and OmpC33, in which OmpC20 was derived from the first clinical isolate). We demonstrate that expression of the OmpC K12 porin in the clinical isolates lowers the MIC, consistent with modified porin function contributing to drug resistance. By a range of assays we have established that the three mutations that occur between OmpC20 and OmpC33 modify transport of both small molecules and antibiotics across the outer membrane. This results in the modulation of resistance to antibiotics, particularly cefotaxime. Small ion unitary conductance measurements of the isolated porins do not show significant differences between isolates. Thus, resistance does not appear to arise from major changes in pore size. Crystal structures of all four OmpC clinical mutants and molecular dynamics simulations also show that the pore size is essentially unchanged. Molecular dynamics simulations suggest that perturbation of the transverse electrostatic field at the constriction zone reduces cefotaxime passage through the pore, consistent with laboratory and clinical data. This subtle modification of the transverse electric field is a very different source of resistance than occlusion of the pore or wholesale destruction of the transverse field and points to a new mechanism by which porins may modulate antibiotic passage through the outer membrane.Peer reviewe
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