The bacterium Escherichia coli O157:H7 is a worldwide threat to
public health and has been implicated in many outbreaks of haemorrhagic colitis,
some of which included fatalities caused by haemolytic ...uraemic syndrome. Close to 75,000 cases of O157:H7 infection are now estimated
to occur annually in the United States. The severity of disease,
the lack of effective treatment and the potential for large-scale outbreaks
from contaminated food supplies have propelled intensive research on the pathogenesis
and detection of E. coli O157:H7 (ref. 4).
Here we have sequenced the genome of E. coli O157:H7 to identify candidate
genes responsible for pathogenesis, to develop better methods of strain detection
and to advance our understanding of the evolution of E. coli, through
comparison with the genome of the non-pathogenic laboratory strain E. coli
K-12 (ref. 5). We find that lateral gene
transfer is far more extensive than previously anticipated. In fact, 1,387
new genes encoded in strain-specific clusters of diverse sizes were found
in O157:H7. These include candidate virulence factors, alternative metabolic
capacities, several prophages and other new functions-all of which could
be targets for surveillance.
Structural complexity is common at the terminations of earthquake surface ruptures; similar deformation may therefore be expected at the end zones of earthquake ruptures at depth. The 8.2 km long ...Glacier Lakes fault (GLF) in the Sierra Nevada is a left‐lateral strike‐slip fault with a maximum observed displacement of 125 m. Within the fault, pseudotachylytes crosscut cataclasites, showing that displacement on the GLF was accommodated at least partly by seismic slip. The western termination of the GLF is defined by a gradual decrease in the displacement on the main fault, accompanied by a 1.4 km wide zone of secondary faulting in the dilational quadrant of the GLF. The secondary faults splay counterclockwise from the main fault trace forming average angles of 39° with the main fault. Slip vectors defined by slickenlines plunge more steeply west for these splay faults than for the GLF. Static stress transfer modeling shows that the orientations of the splays, and the plunge of displacement on those splays, are consistent with displacement on the main fault. The GLF termination structure shows that structural complexity is present at the terminations of faults at seismogenic depths and therefore ruptures that propagate beyond fault terminations, or through step overs between two faults, will likely interact with complex secondary fault structures. Models of dynamic rupture propagation must account for the effect of preexisting structures on the elastic properties of the host rock. Additionally, aftershock distributions and focal mechanisms may be controlled by the geometry and kinematics of structures present at fault terminations.
The RESCUEicp (Randomized Evaluation of Surgery with Craniectomy for Uncontrollable Elevation of intracranial pressure) study has been established to determine whether decompressive craniectomy has a ...role in the management of patients with traumatic brain injury and raised intracranial pressure that does not respond to initial treatment measures. We describe the concept of decompressive craniectomy in traumatic brain injury and the rationale and protocol of the RESCUEicp study.
The contribution of adverse medication events to clinical deterioration is unknown. This study aimed to determine the frequency and nature of rapid response system (RRS) calls that clinicians ...perceived were medication-related using RRS quality arm data.
Analysis of routine data prospectively collected by clinicians responding to RRS calls in an Australian acute tertiary academic hospital.
Between January 2013 and June 2017, 12,221 adult patients triggered the RRS for 25,906 medical emergency team (MET) and 512 code blue calls. Clinicians identified 433 medication-related RRS calls (1.6%) involving 406 patients (3.3%). These included 418 MET calls (1.3 medication-related MET calls per 1000 admissions) and 15 code blue calls (0.045 medication-related code blue calls per 1000 admissions). Medication-related calls occurred earlier in the admission (p = 0.002) and were more common for patients triggering multiple calls during the same admission (p < 0.001), compared to non-medication-related calls. Medication-related calls most commonly were triggered by low blood pressure (38.3%) and involved cardiovascular (43.0%) and nervous system medications (36.0%). Dose-related toxicity (n = 178) was the most frequent adverse medication event contributing to medication-related calls.
One in 30 patients triggering a RRS call experienced medication-related clinical deterioration, most often due to dose related toxicity of cardiovascular system medications. The perceived frequency and potential preventability of this medication-related harm suggest further research is required to increase recognition of medication-related RRS calls by responding clinicians and to reduce the incidence.
The aim of this study was to examine relationships among temperament, endocrinology, and reproductive parameters of bulls enrolled in an 84-day performance test. Angus bulls (n = 60) were housed in ...six pens grouped by age and weight. Pen scores (PS; 1 = docile to 5 = very aggressive) were assigned on Days −1, 27, 55, and 83 of the performance test. On the following day, blood and hair samples were collected, and body weight (BW) and exit velocity (EV) were recorded. Bulls were split into two categories based on; Day −1 PS (PScalm = PS 1 or 2; PSexcitable = PS 3 or 4) and Day 0 EV (EVcalm = slowest 20 bulls; EVexcitable = fastest 20 bulls). Cortisol and testosterone concentrations in serum and hair did not differ (P > 0.10) between PS or EV temperament categories. Sampling day differences (P < 0.01) occurred for serum testosterone, hair cortisol, and hair testosterone concentration; however, serum cortisol concentration did not differ (P > 0.10) over the sampling days. Serum testosterone concentration increased (P < 0.01) from Day 0 to 28, decreased from Day 28 to 56, but Day 84 did not differ from Day 0, 28, or 56. Hair cortisol concentration was greatest (P < 0.01) on Day 0, decreased from Day 28 to 56 but did not differ from Day 56 to 84. Hair testosterone concentration was greatest (P < 0.01) on Day 0 and remained constant from Day 28 to 84. Bulls categorized as PScalm had a greater (P < 0.01) percentage of normal sperm and secondary defects (P < 0.01) when compared with PSexcitable bulls. However, EVcalm bulls had fewer (P < 0.01) primary defects but more (P < 0.01) secondary defects than EVexcitable bulls. In conclusion, bulls exhibited physiological evidence of acclimation during the test as indicated by a reduction in hair cortisol concentration. In addition, the ability of the bulls to acclimate while residing at the testing center may have contributed to little differences observed during the breeding soundness examination portion of the performance test.
Rifting of continental crust initiates faults that are commonly influenced by pre-existing structures. We document newly identified faults cutting Precambrian units in the interior of the NE ...Brazilian margin to assess the effects of structural inheritance on both rift geometry and fault architecture. Stratigraphic and structural data indicate that the faults were active in the main phase of rifting of Gondwana. The influence of pre-existing structures on the Mesozoic rift faulting is scale dependent. Regionally, the faults trend parallel to subvertical, crustal-scale Brasiliano (c. 750-540 Ma) shear zones. Mylonitic foliations and broadly distributed low strain in the lower crust indicated by shear-wave splitting controlled the overall orientation and kinematics of the rift faults. However, outcrop observations of the faults show that at scales up to hundreds of metres, mylonitic foliations have little influence on fault architectures. Faults cross-cut shear zones and do not commonly utilize foliation planes as shear fractures. Instead, slip zones and fractures have a range of orientations that form acute angles to the local foliation orientation. This observation explains the range of focal mechanisms associated with seismicity that coincides with ancient shear zones in intra-continental areas.
The Spectra of T Dwarfs. II. Red Optical Data Burgasser, Adam J; Kirkpatrick, J. Davy; Liebert, James ...
The Astrophysical journal,
09/2003, Letnik:
594, Številka:
1
Journal Article
Secondary insults can adversely influence outcome following severe traumatic brain injury. Monitoring of cerebral extracellular chemistry with microdialysis has the potential for early detection of ...metabolic derangements associated with such events. The objective of this study was to determine the relationship between the fundamental biochemical markers and neurological outcome in a large cohort of patients with traumatic brain injury. Prospectively collected observational neuromonitoring data from 223 patients were analysed. Monitoring modalities included digitally recorded intracranial pressure, cerebral perfusion pressure, cerebrovascular pressure reactivity index and microdialysis markers glucose, lactate, pyruvate, glutamate, glycerol and the lactate/pyruvate ratio. Outcome was assessed using the Glasgow Outcome Scale at 6 months post-injury. Patient-averaged values of parameters were used in statistical analysis, which included univariate non-parametric methods and multivariate logistic regression. Monitoring with microdialysis commenced on median (interquartile range) Day 1 (1-2) from injury and median (interquartile range) duration of monitoring was 4 (2-7) days. Averaged over the total monitoring period levels of glutamate (P = 0.048), lactate/pyruvate ratio (P = 0.044), intracranial pressure (P = 0.006) and cerebrovascular pressure reactivity index (P = 0.01) were significantly higher in patients who died. During the initial 72 h of monitoring, median glycerol levels were also higher in the mortality group (P = 0.014) and median lactate/pyruvate ratio (P = 0.026) and lactate (P = 0.033) levels were significantly lower in patients with favourable outcome. In a multivariate logistic regression model (P < 0.0001), which employed data averaged over the whole monitoring period, significant independent positive predictors of mortality were glucose (P = 0.024), lactate/pyruvate ratio (P = 0.016), intracranial pressure (P = 0.029), cerebrovascular pressure reactivity index (P = 0.036) and age (P = 0.003), while pyruvate was a significant independent negative predictor of mortality (P = 0.004). The results of this study suggest that extracellular metabolic markers are independently associated with outcome following traumatic brain injury. Whether treatment-related improvement in biochemistry translates into better outcome remains to be established.
Clinical microdialysis enables monitoring of the cerebral extracellular chemistry of neurosurgical patients. Introduction of the technique into different hospitals' neurosurgical units has resulted ...in variations in the method of application. There are several variables to be considered, including length of the catheter membrane, type of perfusion fluid, flow rate of perfusion fluid, and on-line compared with delayed analysis of samples. The objects of this study were as follows: 1) to determine the effects of varying catheter characteristics on substance concentration; 2) to determine the relative recovery and true extracellular concentration by varying the flow rate and extrapolating to zero flow; and 3) to compare substance concentration obtained using a bedside enzyme analyzer with that of off-line high-performance liquid chromatography (HPLC).
A specially designed bolt was used to conduct two adjacent microdialysis catheters into the frontal cortex of patients with head injury or poor-grade subarachnoid hemorrhage who were receiving ventilation. One reference catheter (10-mm membrane, perfused with Ringer's solution at 0.3 microl/minute) was constant for all studies. The other catheter was varied in terms of membrane length (10 mm or 30 mm), perfusion fluid (Ringer's solution or normal saline), and flow rate (0.1-1.5 microl/minute). The effect of freezing the samples on substance concentration was established by on-line analysis and then repeated analysis after storage at -70 degrees C for 3 months. Samples assayed with the bedside enzyme analyzer were reassessed using HPLC for the determination of glutamate concentrations.
Two adjacent microdialysis catheters that were identical in membrane length, perfusion fluid, and flow rate showed equivalent results. Variations in perfusion fluid and freezing and thawing of samples did not result in differences in substance concentration. Catheter length had a significant impact on substance recovery. Variations in flow rate enabled the relative recovery to be calculated using a modification of the extrapolation-to-zero-flow method. The recovery was approximately 70% at 0.3 microl/minute and 30% at 1 microl/minute (10-mm membrane) for all analytes. Glutamate results obtained with the enzyme analyzer showed good correlation with those from HPLC.
In hospitals, rapid response systems (RRSs) identify patients who deteriorate and provide critical care at their bedsides to stabilise and escalate care. Medications, including oral and parenteral ...pharmaceutical preparations, are the most common intervention for hospitalised patients and the most common cause of harm. This connection between clinical deterioration and medication safety is poorly understood.
To inform improvements in prevention and management of clinical deterioration, this review aimed to examine how medications contributed to clinical deterioration and how medications were used in RRSs.
A scoping review was undertaken of medication data reported in studies of clinical deterioration or RRSs in diverse hospital settings between 2005 and 2017. Bibliographic database searches used permutations of “rapid response system,” “medical emergency team,” and keyword searching with medication-related terms. Independent selection, quality assessment, and data extraction informed mapping against four medication themes: causes of deterioration, predictors of deterioration, RRS use, and management.
Thirty articles were reviewed. Quality was low: limited by small samples, observational, single-centre designs and few primary medication-related outcomes. Adverse drug reactions and potentially preventable medication errors, involving sedatives, analgesics, and cardiovascular agents, contributed to clinical deterioration. While sparsely reported, outcomes included death and escalation of care. In children, administration of antibiotics or nebulised medications appeared to predict subsequent deterioration. Cardiovascular medications, sedatives, and analgesics commonly were used to manage deterioration but further detail was lacking. Despite reported potential for patient harm, evaluation of medication management systems was limited.
Medications contributed to potentially preventable clinical deterioration, with considerable harm, and were common interventions for its management. When assessing deteriorating patients or caring for patients who require escalation to critical care, clinicians should consider medication errors and adverse reactions. Studies with more specific medication-related, patient-centred end points could reduce medication-related deterioration and refine RRS medication use and management.
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