Effect of ribonuclease and neuraminidase on the electrophoretic mobility of tissue culture cells in parasynchronous growth

Cultured mammalian cells (RPMI no. 41) in parasynchronous growth were treated, at different stages of the mitotic cycle, with neuraminidase and ribonuclease, separately and sequentially, and their electrophoretic mobilities determined. Changes in the electrophoretic mobility of these cells are probably mainly due to variations in the density of negatively charged groups susceptible to neuraminidase, although variations in groups susceptible to ribonuclease may occur. It is suggested that the observed variations in electrophoretic mobility of different cells may be due to differences in the relative lengths of different life-cycle phases. Where G₂ phase is relatively long or G₁ relatively short the cell populations will hve higher mean electrophoretic mobilities.     

Selective Spectrum Antibiotic Modulation of the Gut Microbiome in Obesity and Diabetes Rodent Models

The gastrointestinal tract microbiome has been suggested as a potential therapeutic target for metabolic diseases such as obesity and Type 2 diabetes mellitus (T2DM). However, the relationship between changes in microbial communities and metabolic disease-phenotypes are still poorly understood. In this study, we used antibiotics with markedly different antibacterial spectra to modulate the gut microbiome in a diet-induced obesity mouse model and then measured relevant biochemical, hormonal and phenotypic biomarkers of obesity and T2DM. Mice fed a high-fat diet were treated with either ceftazidime (a primarily anti-Gram negative bacteria antibiotic) or vancomycin (mainly anti-Gram positive bacteria activity) in an escalating three-dose regimen. We also dosed animals with a well-known prebiotic weight-loss supplement, 10% oligofructose saccharide (10% OFS). Vancomycin treated mice showed little weight change and no improvement in glycemic control while ceftazidime and 10% OFS treatments induced significant weight loss. However, only ceftazidime showed significant, dose dependent improvement in key metabolic variables including glucose, insulin, protein tyrosine tyrosine (PYY) and glucagon-like peptide-1 (GLP-1). Subsequently, we confirmed the positive hyperglycemic control effects of ceftazidime in the Zucker diabetic fatty (ZDF) rat model. Metagenomic DNA sequencing of bacterial 16S rRNA gene regions V1-V3 showed that the microbiomes of ceftazidime dosed mice and rats were enriched for the phylum Firmicutes while 10% OFS treated mice had a greater abundance of Bacteroidetes. We show that specific changes in microbial community composition are associated with obesity and glycemic control phenotypes. More broadly, our study suggests that in vivo modulation of the microbiome warrants further investigation as a potential therapeutic strategy for metabolic diseases.     

Robonucelic acid within the cellular peripheral zone and the binding of calcium to ionogenic sites

Ribonuclease was shown to reduce the electrophoretic mobility of a line of cultured mammalian cells (RPMI no. 41), and Ehrlich ascites tumour cells. No reduction was detected in the case of human, mouse or embryonic chick erythrocytes. These data, taken with the various controls, support the hypothesis that RNA is a structural component of the peripheries of two types of cells, but not of erythrocytes from three species. Calcium-binding was studied in RPMI no. 41 cells, Ehrlich ascites tumour cells, and human and mouse eryhrocytes, by measurement of reduction in cellular electrophoretic mobility in suspending solutions containing various concentrations of calcium chloride. The effect of treating cells with neuraminidase and/or ribonuclease on calcium-binding was also studied. The results suggest that less calcium binds to the carboxyl groups of peripheral sialic acids than to the phosphates of peripheral, structural RNA. However, calcium apparently binds most avidly to as yet unidentified anionic sites.     

Effect of point-of-care computer reminders on physician behaviour: a systematic review

Background

The opportunity to improve care using computer reminders is one of the main incentives for implementing sophisticated clinical information systems. We conducted a systematic review to quantify the expected magnitude of improvements in processes of care from computer reminders delivered to clinicians during their routine activities.

Methods

We searched the MEDLINE, Embase and CINAHL databases (to July 2008) and scanned the bibliographies of retrieved articles. We included studies in our review if they used a randomized or quasi-randomized design to evaluate improvements in processes or outcomes of care from computer reminders delivered to physicians during routine electronic ordering or charting activities.

Results

Among the 28 trials (reporting 32 comparisons) included in our study, we found that computer reminders improved adherence to processes of care by a median of 4.2% (interquartile range [IQR] 0.8%–18.8%). Using the best outcome from each study, we found that the median improvement was 5.6% (IQR 2.0%–19.2%). A minority of studies reported larger effects; however, no study characteristic or reminder feature significantly predicted the magnitude of effect except in one institution, where a well-developed, “homegrown” clinical information system achieved larger improvements than in all other studies (median 16.8% [IQR 8.7%–26.0%] v. 3.0% [IQR 0.5%–11.5%]; p = 0.04). A trend toward larger improvements was seen for reminders that required users to enter a response (median 12.9% [IQR 2.7%–22.8%] v. 2.7% [IQR 0.6%–5.6%]; p = 0.09).

Interpretation

Computer reminders produced much smaller improvements than those generally expected from the implementation of computerized order entry and electronic medical record systems. Further research is required to identify features of reminder systems consistently associated with clinically worthwhile improvements.Computerized systems for entering orders and electronic medical records represent two of the most widely recommended improvements in health care.¹ These systems offer the opportunity to improve practice by delivering reminders to clinicians at the point of care. Such reminders range from simple prescribing alerts to more sophisticated support for decision-making.Previous reviews have classified all computer reminders together, including computer-generated paper reminders and email alerts sent to providers, along with reminders generated at the point of care.^2–5 They have also typically reported the proportion of studies with results that were on balance “positive.”^2–4 We conducted a systematic review to quantify the expected magnitude of improvements in processes of care from computer reminders delivered to physicians during their routine electronic ordering or charting activities.