Protein interaction networks in the vasculature prioritize genes and pathways underlying coronary artery disease

Population-based association studies have identified many genetic risk loci for coronary artery disease (CAD), but it is often unclear how genes within these loci are linked to CAD. Here, we perform interaction proteomics for 11 CAD-risk genes to map their protein-protein interactions (PPIs) in human vascular cells and elucidate their roles in CAD. The resulting PPI networks contain interactions that are outside of known biology in the vasculature and are enriched for genes involved in immunity-related and arterial-wall-specific mechanisms. Several PPI networks derived from smooth muscle cells are significantly enriched for genetic variants associated with CAD and related vascular phenotypes. Furthermore, the networks identify 61 genes that are found in genetic loci associated with risk of CAD, prioritizing them as the causal candidates within these loci. These findings indicate that the PPI networks we have generated are a rich resource for guiding future research into the molecular pathogenesis of CAD.

Hospital resource endowments and nosocomial infections: longitudinal evidence from the English National Health Service on Clostridioides difficile between 2011 and 2019

OBJECTIVES

To identify key factors associated with Clostridioides difficile infections (CDIs) in healthcare at the hospital organization level.

DESIGN

Longitudinal study covering the period 2011-2019. Hospital reports were analysed to determine the number of CDIs and several hospital-related environmental factors: financial resources (i.e., cleaning expenditure), spatial resources (i.e., number of single rooms with a private bathroom), human resources (i.e., number of physicians and nursing staff) and cultural resources (i.e., error reporting climate). The relationships between the environmental factors and CDIs were analysed in a hybrid within- and between-hospital random-effect model.

SETTING

A total of 129 general hospital Trusts operating in the English National Health Service (NHS).

PARTICIPANTS

All inpatients in 129 general hospital trusts of the NHS in the years 2011-2019, covering 120,629 cases of CDI.

MAIN OUTCOME MEASURE

Annual number of CDIs per hospital trust.

RESULTS

Single rooms were associated with fewer CDIs at the within-hospital level, but not at the between-hospital level. Similarly, more nursing staff was associated with fewer CDIs at the within-hospital level, but not at the between-hospital level. This effect was not observed for physician staffing. A different picture emerged for the protective effect of cultural resources, with a weakly significant effect of between-hospital differences, but no within-hospital effect. Financial resources were not associated with CDIs either between hospitals or within them over time.

CONCLUSIONS

The present study identified hospital resources with a beneficial influence on CDI rates. Healthcare organizations can use this knowledge for active CDI prevention.

Meeting maximum residue limits: an improved screening technique for the rapid detection of antimicrobial residues in animal food products

A rapid, high-throughput antimicrobial screening assay was developed using either a physical fluid extraction or a solvent extraction technique coupled to the commercially available PremiTest. The solvent extraction approach was fully validated for a wide range of tissues and the fluid extraction approach partially validated for porcine muscle. Both procedures can detect a wide range of antimicrobial compounds at or below maximum residue limit concentrations. The use of a solvent extraction provides an enhanced test capable of detecting a wider range of drugs than the fluid extraction approach at or below half maximum residue limit levels in a variety of matrices. Biochemical methods for the class-specific identification of beta-lactams and sulphonamides following initial screening were developed and validated. The approach is a significant improvement on existing methodologies as a tool for residues monitoring in surveillance programmes.

Detection of streptomycin and dihydrostreptomycin residues in milk, honey and meat samples using an optical biosensor

Immuno-biosensor inhibition assays for the detection of streptomycin and dihydrostreptomycin residues in whole cows' milk, honey, pig kidney and pig muscle are reported. The antibody showed high cross-reactivity with dihydrostreptomycin in various foodstuffs (buffer 103%, milk 96%, honey 84%, kidney extract 129% and muscle extract 98%). There was no significant cross-reaction with other aminoglycosides or commonly used antibiotics. A streptomycin derivative was used to prepare a stable, reusable sensor chip surface. The assay allowed the direct analysis of bovine whole milk (fat content approximately 3.5%). Honey samples required dilution with buffer, while kidney and muscle samples from pigs were homogenized in an aqueous extraction buffer and clarified by centrifugation. The limit of detection for each assay was determined from known streptomycin-free samples (n = 20; mean - (3 x standard deviation)) and the results were as follows: milk 30 microg kg(-1), honey 15 microg kg(-1), kidney 50 microg kg(-1) and muscle 70 microg kg(-1). Repeatability (or relative standard deviation) between runs were calculated (n = 3) at the respective Community maximum residue limits (MRL) and 0.5 x MRL with the exception of honey since no European MRL exists at present. Results were determined as 4.3% (200 microg kg(-1)) and 2.8% (100 microg kg(-1)) in milk, 13.3% (40 microg kg(-1)) and 9.5% (20 microg kg(-1)) in honey, 7.1% (1000 microg kg(-1)) and 7.6% (500 microg kg(-1)) in kidney and 7.1% (500 microg kg(-1)) and 11% (250 microg kg(-1)) in muscle.

Papaverine induces apoptosis in vascular endothelial and smooth muscle cells

Papaverine is a vasodilator commonly used in the treatment of vasospasmic diseases such as cerebral spasm associated with subarachnoid hemorrhage, and in the prevention of spasm of coronary artery bypass graft by intraluminal and/or extraluminal administration. In this study, we examined whether papaverine in the range of concentrations used clinically causes apoptosis of vascular endothelial and smooth muscle cells. Apoptotic cells were identified by morphological changes and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. In porcine coronary endothelial cells (EC) and rat aortic smooth muscle cells (SMC), papaverine at the concentration of 10(-3) M induced membrane blebbing within 1 hour of incubation. Nuclear condensation and fragmentation were found after 24 hours of treatment. The number of apoptotic cells stained with the TUNEL method was significantly higher in the EC and the SMC after 24 hours of incubation with papaverine at the concentrations of 10(-4) and 10(-3) M than their respective controls. Acidified saline solution (pH 4.8, as control for 10(-3) M papaverine hydrochloride) did not cause apoptosis in these cells. These results showed that papaverine could damage endothelial and smooth muscle cells by inducing changes which are associated with events leading to apoptosis. Since integrity of endothelial cells is critical for normal vascular function, vascular administration of papaverine for clinical use, especially at high concentrations (> or = 10(-4) M), should be re-considered.

Nifedipine induces apoptosis in cultured vascular smooth muscle cells from spontaneously hypertensive rats

Apoptosis (programmed cell death) of smooth muscle cells (SMC) in blood vessels is an essential process involved in the control of vessel wall structure. Several antihypertensive drugs currently used in therapy may exert their pharmacological effects by promoting SMC apoptosis. The biochemical events which regulate SMC apoptosis in the vessel wall are complex, and not well understood. We therefore investigated whether treatment of cultured SMC from normotensive Wistar-Kyoto rats (WKY) and from spontaneously hypertensive rats (SHR) with selected antihypertensive drugs would induce SMC apoptosis. We treated aortic SMC from WKY and SHR in vitro with the L-type Ca2+ channel antagonist, nifedipine; with the nitric oxide donor, sodium nitroprusside (SNAP); with forskolin (an activator of adenylyl cyclase); or with thapsigargin (a selective inhibitor of the sarcoplasmic reticulum (SR), Ca2+-ATPase); and compared their apoptosis-promoting effects in SMC derived from the two strains of rats. SMC were derived from the thoracic aorta of 3-4-week-old WKY and SHR, and were used in passages 7-10. Apoptotic cells were detected by in-situ end labeling using the terminal deoxynucleotide transferase-mediated dUTP-nick end-labeling (TUNEL) method, and by morphological examination. We found that: 1) Treatment of cultured aortic SMC with the L-type Ca2+ channel antagonist, nifedipine (5 X 10(-5) M) for 24 hours induced a significantly higher level of apoptosis in SHR cells than in SMC from WKY. Cells from WKY, following exposure to nifedipine for 72 hours, exhibited a similar response to the cells from SHR treated for 24 hours. This was detectable by both morphological criteria as well as DNA labeling by the TUNEL technique. 2) Similar treatment of these cells with thapsigargin (1 x 10(-7) M) led to morphological alterations characteristic of apoptotic cells in SMC from both WKY and SHR, and cells from SHR but not WKY were labeled by the TUNEL technique at 24 hours. The TUNEL method did however identify cells from both WKY and SHR as apoptotic after 48 and 72 hours of treatment. 3) The addition of SNAP, or forskolin to the cultured SMC induced significant, but low levels of apoptosis in WKY SMC only. This selective apoptosis-promoting effect of nifedipine in SHR SMC may result from differences in the control of intracellular Ca2+ between the two strains of cells, or it may indicate that the signaling pathways which regulate apoptosis are different in SMC from the normotensive and the hypertensive rats. Our findings imply that SMC apoptosis may be a selective target for pharmacological intervention in hypertension.

Plasma lipid patterns in patients with suspected glaucoma

We carried out analysis of plasma lipid and lipoprotein levels in 183 patients (92 women and 91 men) referred because of suspected glaucoma. We found an excess of hypertriglyceridemia among the women. Type IV lipoproteinemia was the most common lipoprotein abnormality. Lipid analysis was unhelpful in determining whether glaucoma was present or what type of glaucoma was present. The prevalence of cardiovascular disease was similar among patients with and without a lipoprotein abnormality.

Family outbreak of yersiniosis

Yersinia enterocolitica biotype 1, serotype O:21 was isolated from feces or rectal washings of three members of one family in northwestern Saskatchewan. The three isolates gave positive pathogenicity tests in guinea pigs with cultures grown at 22 degrees C as inoculum. All three cases showed clinical symptoms consistent with yersiniosis. All three cases had symptoms of diarrhea and abdominal pain, and two cases had recorded fever. In two cases, appendicitis was initially suspect. One case with ileitis and peritonitis was fatal. The environmental source of the infection was not found, but river water, milk, and person-to-person spread are discussed as possible sources of the infections. The need for microbiology laboratories to culture stool specimens specifically for Y. enterocolitica, using cold-enrichment techniques is emphasized. This family outbreak of yersiniosis provides further evidence that certain biotype 1 strains of Y. enterocolitica are pathogenic.

Prognostic indicators in ocular hypertension

Decreased pupil size and lens opacity, rather than high intraocular pressure, have been cited as reasons for the concentric constriction of the visual field occurring in eyes with suspected glaucoma. We studied a group of eyes showing ocular hypertension and found increased concentric constriction of the visual field when compared with that of healthy control eyes. While the degree of constriction and patient age tended to predict the transition to glaucoma, we found the absence of hypermetropia to be a strong prognostic indicator.

Hypertension screening in schools: results of the Dallas study

The purpose of this study was to determine the prevalence of persistent blood pressure elevations in an eighth-grade population composed of three ethnic groups, and to determine the feasibility of using school health facilities for hypertension screening. Blood pressure was recorded in 10,641 subjects (90% of the total eighth-grade population) in the Dallas Independent School District. Blacks made up 46% of the population; non-Latin whites, 40.1%; and Latin-Americans, 13.9%. On the first blood pressure screening, 8.9% had systolic or diastolic pressures or both at or above the 95th percentile. Of those whose blood pressures were elevated on the first examination, 98.3% were reexamined. After the third examination, 1.2% continued to have systolic hypertension, and 0.37% diastolic hypertension. No student had diastolic pressure above 90 mm Hg on all three examinations. The prevalence of persistent hypertension was similar for the three ethnic groups. Analysis of variation in blood pressure measurements revealed that the school nurses introduced a relatively small increase in variability. These data indicate that although school screening initially identifies large numbers of students as having inconstant pressure elevations, subsequent follow-up examinations show that less than 2% have persistent hypertension.