A "1H nuclear magnetic resonance study of structural and organisational changes in the cell

Increasing importance is being placed on understanding the role of membrane lipids in many different areas of biochemistry. It is of interest to determine what interactions may occur between membrane lipids and drug species. Furthermore, an increasing body of evidence suggests that membrane lipids are involved in the pathology of numerous diseases such as rheumatoid arthritis, cancer and HIV. Clearly, the more information available on the mechanisms involved in diseases, the greater the potential for identifying a cure or even a prevention. "1H nuclear magnetic resonance (NMR) spectroscopy was used to study the alterations in membrane lipid organisation and structure in intact, viable cultured cells. Changes in the "1H NMR spectra and the spin-lattice relaxation measurements of the human K562 and the rat FRTL-5 cell lines were observed on the addition of the fatty acid species: triolein, evening primrose oil, arachidonic acid and ITF 1779. Results indicate that the membrane lipids are reorganised to accommodate the interpolation of these molecules. The spatial arrangement adopted by each of these species appeared to dictate its effect on the lipids. Doxorubicin and menadione, both known to cause oxidative stress, were added to K562 cells. Although both agents are known to act by different mechanisms, the NMR data and scanning electron microscopy suggested that both caused similar alterations in the membrane organisation and lipid fluidity. Protrusions were formed indicating areas of weakness in the membrane. Spin-echo NMR was employed to investigate the action of the thiol-containing compounds, penicillamine, captopril and N-acetylcysteine in erythrocytes under conditions of oxidative stress. Results indicate that while captopril acts as a free radical scavenger, penicillamine may act as either oxidant or reductant. N-acetylcysteine was observed to act as a reducing agent. (author)Available from British Library Document Supply Centre- DSC:DXN055879 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

COVID-19 testing in outbreak-free care homes:what are the public health benefits?

BACKGROUND COVID-19 care home outbreaks represent a significant proportion of COVID-19 morbidity and mortality in the UK. National testing initially focused on symptomatic care home residents, before extending to asymptomatic cohorts. AIM The aim was to describe the epidemiology and transmission of COVID-19 in outbreak free care homes. METHODS A two-point prevalence survey of COVID-19, in 34 Liverpool care homes, was performed in April and May 2020. Changes in prevalence were analysed. Associations between care home characteristics, reported infection, prevention and control interventions, and COVID-19 status were described and analysed. FINDINGS No resident developed COVID-19 symptoms during the study. There was no significant difference between: the number of care homes containing at least one test positive resident between the first (17.6%, 95%CI 6.8-34.5) and second round (14.7%, 95%CI 5.0-31.1) of testing (p>0.99); and the number of residents testing positive between the first (2.1%, 95%CI 1.2-3.4) and second round (1.0%, 95%CI 0.5-2.1) of testing (p=0.11). Care homes providing nursing care (RR 7.99, 95%CI 1.1-57.3) and employing agency staff (RR 8.4, 95%CI 1.2-60.8) were more likely to contain test positive residents. Closing residents shared space was not associated with residents testing positive (RR 2.63, 95%CI 0.4-18.5). CONCLUSIONS Asymptomatic COVID-19 care homes showed no evidence of disease transmission or development of outbreaks; suggesting that current infection prevention and control measures are effective in preventing transmission. Repeat testing at 2-3 weeks had limited or no public health benefits over regular daily monitoring of staff and residents for symptoms. These results should inform policies calling for regular testing of asymptomatic residents

The nucleoporin Nup88 is interacting with nuclear lamin A

The nuclear pore protein Nup88 binds specifically lamin A, but not B-type lamins, in vitro and in vivo. Expression of green fluorescent protein–lamin A in cells causes a masking of binding sites for Nup88 antibodies, which disappears in cells expressing mutants of lamin A that are associated with laminopathic diseases