Extracellular vesicle signalling in atherosclerosis.

Atherosclerosis is a major cardiovascular disease and in 2016, the World Health Organisation (WHO) estimated 17.5 million global deaths, corresponding to 31% of all global deaths, were driven by inflammation and deposition of lipids into the arterial wall. This leads to the development of plaques which narrow the vessel lumen, particularly in the coronary and carotid arteries. Atherosclerotic plaques can become unstable and rupture, leading to myocardial infarction or stroke. Extracellular vesicles (EVs) are a heterogeneous population of vesicles secreted from cells with a wide range of biological functions. EVs participate in cell-cell communication and signalling via transport of cargo including enzymes, DNA, RNA and microRNA in both physiological and patholophysiological settings. EVs are present in atherosclerotic plaques and have been implicated in cellular signalling processes in atherosclerosis development, including immune responses, inflammation, cell proliferation and migration, cell death and vascular remodeling during progression of the disease. In this review, we summarise the current knowledge regarding EV signalling in atherosclerosis progression and the potential of utilising EV signatures as biomarkers of disease.

Development of real-time PCR assays for specific detection of hmsH, hmsF, hmsR, and irp2 located within the 102-kb pgm locus of Yersinia pestis.

Virulent isolates of three pathogenic Yersinia species (Yersinia pestis, Yersinia pseudotuberculosis, and Yersinia enterocolitica) harbor a 102-kb chromosomal region which encodes elements critical for virulence. A 35-kb high pathogenicity island is contained in this region, is a known virulence determinant, contains irp1 and irp2 iron-regulating genes. An additional segment, the 68-kb high pathogenicity island, contains genetic elements responsible for conferring the Y. pestis pigmentation phenotype on Congo red agar at 28 °C. Collectively, these contiguous segments are referred to as the pigmentation (pgm) locus, the absence of which results in strain attenuation and exemption from CDC Select Agent status. In this study, we developed a set of four real-time PCR assays to detect the presence or absence of multiple virulence genes located within this region. Specifically, we designed TaqMan(®) PCR assays to individually detect three hemin storage genes (hmsH, hmsF, and hmsR) which are genetic elements that confer the pigmentation phenotype, as well as the iron-regulating status of 25 Y. pestis isolates (representing 23 different strains), thus establishing a molecular based assay capable of determining the pgm status of candidate Y. pestis isolates. Included in the validation process, was a comparison of these real-time PCR assays and newly developed conventional PCR assays targeting much larger areas of the 102-kb region (including one assay spanning hmsR and hmsF, one spanning hmsH and hsmF, one targeting hmsF, and one targeting irp2). There was high concordance between the conventional and real-time PCR assays for all Y. pestis strains tested. The results from the comparative analysis document the specificity and sensitivity of the real-time PCR assays and further solidify the ostensible benefits of real-time PCR over conventional PCR.

Regulation of the subcellular distribution of key cellular RNA-processing factors during permissive human cytomegalovirus infection.

Alternative splicing and polyadenylation of human cytomegalovirus (HCMV) immediate-early (IE) pre-mRNAs are temporally regulated and rely on cellular RNA-processing factors. This study examined the location and abundance of essential RNA-processing factors, which affect alternative processing of UL37 IE pre-mRNAs, during HCMV infection. Serine/threonine protein kinase 1 (SRPK1) phosphorylates serine/arginine-rich proteins, necessary for pre-spliceosome commitment. It was found that HCMV infection progressively increased the abundance of cytoplasmic SRPK1, which is regulated by subcellular partitioning. The essential polyadenylation factor CstF-64 was similarly increased in abundance, albeit in the nucleus, proximal to and within viral replication compartments (VRCs). In contrast, the location of polypyrimidine tract-binding protein (PTB), known to adversely affect splicing of HCMV major IE RNAs, was temporally regulated during infection. PTB co-localized with CstF-64 in the nucleus at IE times. By early times, PTB was detected in punctate cytoplasmic sites of some infected cells. At late times, PTB relocalized to the nucleus, where it was notably excluded from HCMV VRCs. Moreover, HCMV infection induced the formation of nucleolar stress structures, fibrillarin-containing caps, in close proximity to its VRCs. PTB exclusion from HCMV VRCs required HCMV DNA synthesis and/or late gene expression, whereas the regulation of SRPK1 subcellular distribution did not. Taken together, these results indicated that HCMV increasingly regulates the subcellular distribution and abundance of essential RNA-processing factors, thereby altering their ability to affect the processing of viral pre-mRNAs. These results further suggest that HCMV infection selectively induces sorting of nucleolar and nucleoplasmic components.

Health literacy and patient understanding of screening tests for aneuploidy and neural tube defects.

OBJECTIVE: To determine if health literacy is associated with patient understanding of prenatal screening tests for fetal aneuploidy and neural tube defects. METHODS: We performed a prospective observational study on a cohort of English-speaking patients receiving prenatal care in two resident-staffed ambulatory clinics. Health literacy was measured using the Rapid Estimate of Adult Literacy in Medicine-7. Understanding of the prenatal screening tests was assessed using a modified Maternal Serum Screening Knowledge Questionnaire. RESULTS: Over an 8-month period, 125 patients were approached, and 101 (81%) consented to the study. Thirty-eight (38%) women demonstrated low health literacy. Patients with low health literacy were more likely to demonstrate inadequate understanding when compared to those with adequate health literacy (97% versus 11%, respectively; P < 0.01). Similarly, patients with < 12th grade education were more likely to have inadequate understanding when compared to patients with > 12th grade education (53% versus 30%, respectively; P = 0.02). Health literacy is a more sensitive and specific predictor of inadequate understanding than education (sensitivity 84% versus 70%, respectively, P < 0.05; specificity 98% versus 47%, respectively, P < 0.05). CONCLUSION: Patients with low health literacy are more likely to demonstrate inadequate understanding of these prenatal screening tests than women with adequate health literacy.

When has an induction failed?

OBJECTIVE: To evaluate the length of the latent phase that, during labor inductions in nulliparous women, is associated with significantly decreased chance of vaginal delivery and increased risk of maternal and neonatal morbidity. METHODS: All inductions of labor during a 6-month period were identified. Only those women who were nulliparous with a pregnancy of 36 weeks or more of gestation underwent further data analysis. Demographic data, intrapartum course, and maternal and neonatal outcomes were abstracted from the medical record. The latent phase was defined as beginning after oxytocin had been initiated and amniotomy performed and continuing until either 4 cm cervical dilation and 80% effacement or 5 cm cervical dilation regardless of effacement. RESULTS: A total of 397 nulliparous women, 32% of whom underwent cervical ripening, presented during the study period. Only 8 women (2%) never achieved active phase labor before cesarean, and the overall cesarean rate was 26.0%. A longer latent phase was associated with a greater rate of cesarean delivery, although only after 18 hours did a majority of induced labors result in cesarean. Chorioamnionitis and postpartum hemorrhage were more frequent with latent phases of labor greater than 18 hours (16% and 26%, respectively), although these diagnoses did not translate into greater risk of transfusion, hysterectomy, or prolonged hospitalization. Neonatal outcomes, including meconium passage, fetal acidemia, neonatal intensive care unit admission, or other morbidity did not increase in conjunction with longer latent phases. CONCLUSION: A latent phase of as long as 18 hours during induction of labor in nulliparous women allows the majority of these women to achieve a vaginal delivery without being subject to a significantly increased risk of significant maternal or neonatal morbidity. LEVEL OF EVIDENCE: II-2.

Comparison of 10 different hemostatic dressings in an aortic injury.

BACKGROUND: Uncontrolled hemorrhage is the leading preventable cause of death on the battlefield. Similarly, hemorrhage accounts for 80% of all deaths within the first 48 hours of injury in civilian trauma patients. New methods of hemostasis are required to reduce hemorrhagic mortality. The purpose of this study was to compare nine hemostatic dressings for their efficacy in controlling bleeding from an otherwise fatal aortic injury in a pig model. Each hemostatic dressing was compared with the current standard U.S. Army field gauze dressing for a 1-hour period. METHODS: Fifty-nine anesthetized pigs were instrumented with catheters and splenectomized. Nine test dressings (n = 5 per group) and two control groups (gauze, n = 9; suture, n = 5) were applied to a 4.4-mm aortotomy through the spraying jet of blood, and direct pressure was held for 4 minutes and then released. Survival, blood loss, and other variables were measured over a 1-hour period. RESULTS: All animals with fibrin dressing and those receiving suture repair (five of five in both groups) survived the 1-hour observation period with minimal bleeding in the postocclusion period (< 37 mL). Those in the other dressing groups exsanguinated within 10 minutes, except for two animals in the gauze group surviving 1 hour. CONCLUSION: With one 4-minute application, a single fibrin dressing stopped bleeding from an aortotomy, which was equivalent to sutured repair. No other test group exhibited any evidence of significant hemostatic efficacy.