Hemodynamic monitoring in the critically ill: spanning the range of kidney function

Critically ill patients often have deranged hemodynamics. Physical examination, central venous pressure, and pulmonary artery occlusion pressure ("wedge") have been shown to be unreliable at assessing volume status, volume responsiveness, and adequacy of cardiac output in critically ill patients. Thus, invasive and noninvasive cardiac output monitoring is a core feature of evaluating and managing a hemodynamically unstable patient. In this review, we discuss the various techniques and options of cardiac output assessment available to clinicians for hemodynamic monitoring in the intensive care unit. Issues related to patients with kidney disease, such as timing and location of arterial and central venous catheters and the approach to hemodynamics in patients treated by long-term dialysis also are discussed.     

Bacterial RNA induces myocyte cellular dysfunction through the activation of PKR

Severe sepsis and the ensuing septic shock are serious life threatening conditions. These diseases are triggered by the host's over exuberant systemic response to the infecting pathogen. Several surveillance mechanisms have evolved to discriminate self from foreign RNA and accordingly trigger effective cellular responses to target the pathogenic threats. The RNA-dependent protein kinase (PKR) is a key component of the cytoplasmic RNA sensors involved in the recognition of viral double-stranded RNA (dsRNA). Here, we identify bacterial RNA as a distinct pathogenic pattern recognized by PKR. Our results indicate that natural RNA derived from bacteria directly binds to and activates PKR. We further show that bacterial RNA induces human cardiac myocyte apoptosis and identify the requirement for PKR in mediating this response. In addition to bacterial immunity, the results presented here may also have implications in cardiac pathophysiology.     

Identifying generic predictors of outcome in patients presenting to primary care with nonspinal musculoskeletal pain

Objective

To identify which generic prognostic factors, such as pain intensity, levels of disability, and psychological factors, are most strongly associated with outcome from musculoskeletal pain, regardless of the location of pain. We tested the hypothesis that pain location does not add predictive value to these generic prognostic models, and that such prognostic factors are equally important across different pain locations.

Methods

Data from a prospective observational cohort of primary care patients with acute (n = 413) and chronic (n = 414) nonspinal musculoskeletal pain were used to develop predictive models. The analysis was carried out in 3 steps: derivation of predictive models including generic factors only, investigation of the added predictive value of pain location, and investigation of effect modification by pain location.

Results

Generic factors predicted outcome over different time periods (3 months and 12 months) and for both acute and chronic musculoskeletal pain (area under the receiver operating characteristic curve 0.73–0.75). The most consistent predictors of poor outcome were having had the same complaint in the previous year (odds ratio range 2.03–3.46), a lower level of education, lower scores on the Short Form 36 vitality subscale, using pain medication at baseline, and being bothered by the complaint more often in the past 3 months. Pain location variables only slightly improved the predictive ability of the models over generic factors and were inconsistent across the models.

Conclusion

Generic factors appear to play an important role in the prognosis of acute and chronic nonspinal musculoskeletal pain, regardless of the location of pain.     

Media coverage on electromagnetic fields and health: Content analysis of Dutch newspaper articles and websites

The way health risks of electromagnetic fields are portrayed in the media may shape public concerns that the growing exposure to electromagnetic fields in daily life constitutes a health hazard. We analysed the content of information on electromagnetic fields and health in Dutch media to identify aspects that might be linked to the public perception of electromagnetic fields. A systematic search was performed on archives of five major Dutch newspapers (from March 2008 to March 2010) and on the internet (in April 2010). Content analyses included the identification of main characteristics and the context or frame in which the information can be clearly understood. We identified 155 newspaper articles and 23 relevant websites. Analyses showed that the media content often suggested a negative relationship between electromagnetic field exposure and health but lacked detailed information about research, technical aspects, possible biological mechanisms and regulation policy. Regional media predominantly featured conflicts around the placing of electromagnetic equipment. Across all media, information on electromagnetic fields and health was mostly framed in terms of precaution and concern. We conclude that the content does not reflect a scientific perspective, focusing on the nature of and exposure to electromagnetic fields, potential biological mechanisms, the evidence and the magnitude of health effects, but rather seems to follow a layman's perspective of risk. We also discuss ways to improve on the quality of media coverage on electromagnetic fields.     

Determination of anti-Müllerian hormone concentrations in blood as a tool to select Holstein donor cows for embryo production: from the laboratory to the farm

High between-animal variability in the number of embryos produced by multiple ovulation and embryo transfer (MOET) and ovum pick-up and in vitro production (OPU-IVP) methods remains a major limit to the development of embryo biotechnologies in cattle. The measurement of anti-Müllerian hormone (AMH) endocrine concentrations in cows can help to predict their follicular and ovulatory responses to gonadotrophin treatment. The present study aimed to provide practical information for a simple prognostic method based on AMH measurement in Holstein cows. Accurate AMH concentrations could be measured with ELISA in blood or plasma. In cows undergoing repeated OPU protocols over 1 year, the AMH concentrations measured in plasma samples collected before each gonadotrophin treatment were found to be highly repeatable and were tightly correlated with follicular responses. From data obtained at both an experimental station and farm settings, it was possible to propose AMH cut-off values to identify low-responding cows. Gonadotrophin-stimulated cows producing fewer than 15 large follicles at oestrus and fewer than 10 embryos in MOET protocols could be discarded efficiently with plasma AMH concentrations below 87 and 74pgmL(-1), respectively. In conclusion, we propose a prognostic method based on a single AMH measurement to improve the results of embryo biotechnologies.     

Granulosa cells are refractory to FSH action in individuals with a low antral follicle count

The reason ovarian function and fertility are diminished in women with a low antral follicle count (AFC), despite significant numbers of follicles remaining in ovaries, is unknown. The bovine model is unique to address this question because cattle and women with a low AFC exhibit similar phenotypic characteristics including a diminished ovarian reserve, reduced circulating concentrations of anti-Müllerian hormone (AMH) but heightened FSH secretion during reproductive cycles. Because women and cattle with a low AFC respond minimally to gonadotropin stimulation during IVF cycles or superovulation, granulosa cells in individuals with a low AFC are hypothesised to be refractory to FSH. The present study evaluates this hypothesis by testing whether capacity of granulosa cells to respond to FSH differs between cattle with a low and a high AFC. Granulosa cells from cattle with a low (≤15 follicles ≥3 mm in diameter) or a high (≥25 follicles) AFC were cultured with different doses of FSH. Treatments were evaluated by measurement of oestradiol (E), progesterone (P) and AMH in media and abundance of mRNAs for aromatase (CYP19A1), AMH, FSH receptor (FSHR) and oxytocin (OXT). Progesterone and OXT mRNA are well-established markers of granulosa cell luteinisation. Although high doses of FSH induced granulosa cell luteinisation, basal and FSH-induced increases in E and AMH production and expression of mRNAs for CYP19A1, FSHR and AMH in granulosa cells were much lower, while P production and OXT mRNA expression were higher in non-luteinised and luteinised granulosa cells from the low than the high AFC group. Granulosa cells in cattle with a low AFC are refractory to FSH action, which could explain why ovarian function, responsiveness to gonadotropin stimulation and fertility are diminished in individuals with a low versus a high AFC.     

Chicken as reservoir for extraintestinal pathogenic Escherichia coli in humans, Canada

We previously described how retail meat, particularly chicken, might be a reservoir for extraintestinal pathogenic Escherichia coli (ExPEC) causing urinary tract infections (UTIs) in humans. To rule out retail beef and pork as potential reservoirs, we tested 320 additional E. coli isolates from these meats. Isolates from beef and pork were significantly less likely than those from chicken to be genetically related to isolates from humans with UTIs. We then tested whether the reservoir for ExPEC in humans could be food animals themselves by comparing geographically and temporally matched E. coli isolates from 475 humans with UTIs and from cecal contents of 349 slaughtered animals. We found genetic similarities between E. coli from animals in abattoirs, principally chickens, and ExPEC causing UTIs in humans. ExPEC transmission from food animals could be responsible for human infections, and chickens are the most probable reservoir.