Prolonged concurrent hypotension and low bispectral index ('double low') are associated with mortality, serious complications, and prolonged hospitalization after cardiac surgery.

BACKGROUND: Low bispectral index (BIS) and low mean arterial pressure (MAP) are associated with worse outcomes after surgery. We tested the hypothesis that a combination of these risk factors, a 'double low', is associated with death and major complications after cardiac surgery. METHODS: We used data from 8239 cardiac surgical patients from two US hospitals. The primary outcomes were 30-day mortality and a composite of in-hospital mortality and morbidity. We examined whether patients who had a case-averaged double low, defined as time-weighted average BIS and MAP (calculated over an entire case) below the sample mean but not in the reference group, had increased risk of the primary outcomes compared with patients whose BIS and/or MAP were at or higher than the sample mean. We also examined whether a prolonged cumulative duration of a concurrent double low (simultaneous low MAP and BIS) increased the risk of the primary outcomes. RESULTS: Case-averaged double low was not associated with increased risk of 30-day mortality {odds ratio [OR] 1.73 [95% confidence interval (CI) 0.94-3.18] vs reference; P =0.01} or the composite of in-hospital mortality and morbidity [OR 1.47 (95% CI 0.98-2.20); P =0.01] after correction for multiple outcomes. A prolonged concurrent double low was associated with 30-day mortality [OR 1.06 (95% CI 1.01-1.11) per 10-min increase; P =0.001] and the composite of in-hospital mortality and morbidity [OR 1.04 (95% CI 1.01-1.07), P =0.004]. CONCLUSIONS: A prolonged concurrent double low, but not a case-averaged double low, was associated with higher morbidity and mortality after cardiac surgery.

Composition and functionality of whey protein phospholipid concentrate and delactosed permeate.

Whey protein phospholipid concentrate (WPPC) and delactosed permeate (DLP) are 2 coproducts of cheese whey processing that are currently underused. Past research has shown that WPPC and DLP can be used together as a functional dairy ingredient in foods such as ice cream, soup, and caramel. However, the scope of the research has been limited to 1 WPPC supplier. The objective of this research was to fully characterize a range of WPPC. Four WPPC samples and 1 DLP sample were analyzed for chemical composition and functionality. This analysis showed that WPPC composition was highly variable between suppliers and lots. In addition, the functionality of the WPPC varies depending on the supplier and testing pH, and cannot be correlated with fat or protein content because of differences in processing. The addition of DLP to WPPC affects functionality. In general, WPPC has a high water-holding capacity, is relatively heat stable, has low foamability, and does not aid in emulsion stability. The gel strength and texture are highly dependent on the amount of protein. To be able to use these 2 dairy products, the composition and functionality must be fully understood.

Whey protein phospholipid concentrate and delactosed permeate: Applications in caramel, ice cream, and cake.

Whey protein phospholipid concentrate (WPPC) and delactosed permeate (DLP) are 2 coproducts of cheese whey processing that are currently underutilized. Past research has shown that WPPC and DLP can be used together as a functional dairy ingredient in foods such as ice cream, soup, and caramel. However, the scope of the research has been limited to a single WPPC supplier. The variability of the composition and functionality of WPPC was previously studied. The objective of this research was to expand on the previous study and examine the potential applications of WPPC and DLP blends in foods. In ice cream, WPPC was added as a natural emulsifier to replace synthetic emulsifiers. The WPPC decreased the amount of partially coalesced fat and increased the drip-through rate. In caramel, DLP and WPPC replaced sweetened condensed skim milk and lecithin. Cold flow increased significantly, and hardness and stickiness decreased. In cake, DLP and WPPC were added as a total replacement of eggs, with no change in yield, color, or texture. Overall, WPPC and DLP can be utilized as functional dairy ingredients at a lower cost in ice cream and cake but not in chewy caramel.

Intraoperative arterial blood pressure lability is associated with improved 30 day survival.

BACKGROUND: Arterial blood pressure lability, defined as rapid changes in arterial blood pressure, occurs commonly during anaesthesia. It is believed that hypertensive patients exhibit more lability during surgery and that lability is associated with poorer outcomes. Neither association has been rigorously tested. We hypothesized that hypertensive patients have more blood pressure lability and that increased lability is associated with increased 30 day mortality. METHODS: This was a retrospective single-centre study of surgical patients from July 2008 to December 2012. Intraoperative data were extracted from the electronic anaesthesia record. Lability was calculated as the modulus of the percentage change in mean arterial pressure between consecutive 5 min intervals. The number of episodes of lability >10% was tabulated. Multivariate logistic regression was performed to determine the association between lability and 30 day mortality using derivation and validation cohorts. RESULTS: Inclusion criteria were met by 52 919 subjects. Of the derivation cohort, 53% of subjects were hypertensive and 42% used an antihypertensive medication. The median number of episodes of lability >10% was 9 (interquartile range 5-14) per patient. Hypertensive subjects demonstrated more lability than normotensive patients, 10 (5-15) compared with 8 (5-12), P<0.0001. In subjects taking no antihypertensive medication, lability >10% was associated with decreased 30 day mortality, odds ratio (OR) per episode 0.95 [95% confidence interval (CI) 0.92-0.97], P<0.0001. This result was confirmed in the validation cohort, OR 0.96 (95% CI 0.93-0.99), P=0.01, and in hypertensive patients taking no antihypertensive medication, OR 0.96 (95% CI 0.93-0.99), P=0.002. Use of any antihypertensive medication class reduced this effect. CONCLUSIONS: Intraoperative arterial blood pressure lability occurs more often in hypertensive patients. Contrary to common belief, increased lability was associated with decreased 30 day mortality.

Low intraoperative tidal volume ventilation with minimal PEEP is associated with increased mortality.

BACKGROUND: Anaesthetists have traditionally ventilated patients' lungs with tidal volumes (TVs) between 10 and 15 ml kg(-1) of ideal body weight (IBW), without the use of PEEP. Over the past decade, influenced by the results of the Acute Respiratory Distress Syndrome Network trial, many anaesthetists have begun using lower TVs during surgery. It is unclear whether the benefits of low TV ventilation can be extended into the perioperative period. METHODS: We reviewed the records of 29 343 patients who underwent general anaesthesia with mechanical ventilation between January 1, 2008 and December 31, 2011. We calculated TV kg(-1) IBW, PEEP, peak inspiratory pressure (PIP), and dynamic compliance. Cox regression analysis with propensity score matching was performed to examine the association between TV and 30-day mortality. RESULTS: Median TV was 8.6 [7.7-9.6] ml kg(-1) IBW with minimal PEEP [4.0 (2.2-5.0) cm H2O]. A significant reduction in TV occurred over the study period, from 9 ml kg(-1) IBW in 2008 to 8.3 ml kg(-1) IBW in 2011 (P=0.01). Low TV 6-8 ml kg(-1) IBW was associated with a significant increase in 30-day mortality vs TV 8-10 ml kg(-1) IBW: hazard ratio (HR) 1.6 [95% confidence interval (CI) [1.25-2.08], P=0.0002]. The association remained significant after matching: HR 1.63 [95% CI (1.22-2.18), P<0.001]. There was only a weak correlation between TV kg(-1) IBW and dynamic compliance (r=-0.006, P=0.31) and a weak-to-moderate correlation between TV kg(-1) IBW and PIP (r=0.32 P<0.0001). CONCLUSIONS: Use of low intraoperative TV with minimal PEEP is associated with an increased risk of 30-day mortality.

ICOS is critical for CD40-mediated antibody class switching.

The inducible co-stimulatory molecule (ICOS) is a CD28 homologue implicated in regulating T-cell differentiation. Because co-stimulatory signals are critical for regulating T-cell activation, an understanding of co-stimulatory signals may enable the design of rational therapies for immune-mediated diseases. According to the two-signal model for T-cell activation, T cells require an antigen-specific signal and a second, co-stimulatory, signal for optimal T-cell activation. The co-stimulatory signal promotes T-cell proliferation, lymphokine secretion and effector function. The B7-CD28 pathway provides essential signals for T-cell activation, but does not account for all co-stimulation. We have generated mice lacking ICOS (ICOS-/- ) to determine the essential functions of ICOS. Here we report that ICOS-/- mice exhibit profound deficits in immunoglobulin isotype class switching, accompanied by impaired germinal centre formation. Class switching was restored in ICOS-/- mice by CD40 stimulation, showing that ICOS promotes T-cell/B-cell collaboration through the CD40/CD40L pathway.

Intact soil-core microcosms compared with multi-site field releases for pre-release testing of microbes in diverse soils and climates.

Intact soil-core microcosms were used to compare persistence of Pseudomonas chlororaphis 3732RN-L11 in fallow soil and on wheat roots with field releases at diverse sites. Parallel field and microcosm releases at four sites in 1996 were repeated with addition of one site in 1997. Microcosms were obtained fresh and maintained at 60% soil water holding capacity in a growth chamber at 70% relative humidity, a 12-hour photoperiod, and constant temperature. Persistence of 3732RN-L11 was measured at each site in field plots and microcosms at 7-21 day intervals, and in duplicate microcosms sampled at an independent laboratory. Linear regression slopes of field plot and microcosm persistence were compared for each site, and between identical microcosms sampled at different sites, using log10 transformed plate counts. Microcosm persistence closely matched field plots for wheat roots, but persistence in fallow soil differed significantly in several instances where persistence in field plots was lower than in microcosms. Analysis of weather variations at each site indicated that rainfall events of 30-40 mm caused decreased persistence in fallow soil. Cooler temperatures enhanced persistence in field plots at later time points. Inter-laboratory comparison of regression slopes showed good agreement for data generated at different sites, though in two instances, longer sampling periods at one site caused significant differences between the sites. Soil characteristics were compared and it was found that fertility, namely the carbon to nitrogen ratio, and the presence of expanding clays, were related to persistence. These microcosm protocols produced reliable data at low cost, and were useable for pre-release risk analyses for microorganisms.

[Evaluation of the effect of ecologically hazardous pollutants on the bacteriolytic activity of the predatory bacterium Bdellovibrio]. / Otsenka vliianiia ékologicheski znachimykh polliutantov na funktsional'nuiu aktivnost' bakterial'nykh khishchnikov, Bdellovibrio.

We studied the effect of various concentrations of ecologically hazardous pollutants, urea, phenol, diuron, and cadmium ions, on the physiological activity and survival of the parasitic bacterium Bdellovibrio. Experiments showed that the survival of bdellovibrios in the presence of the pollutants was two times higher when they were cultivated on agar than when they were cultivated in liquid medium. The data obtained are in agreement with the recent concept of the surface-associated state as a survival strategy of bdellovibrios in various ecosystems.

Validation of Microcosms for Examining the Survival of Pseudomonas aureofaciens (lacZY) in Soil.

Evaluating the safety and efficacy of a recombinant bacterium prior to its release into the terrestrial environment requires that risk assessment data be collected in the laboratory. Much of this information is obtained with the use of microcosms. The design of the microcosm significantly affects the ability of the recombinant microorganism to survive in soil and, thus, complicates the risk assessment process. To standardize microcosms for future use, we evaluated the survival of Pseudomonas aureofaciens 3732 RN-L11 (lacZY Rif(supr) Nal(supr)) in intact soil cores (5.0 by 15 cm; polyvinyl chloride core) and disturbed soil microcosms (50 g of fresh, sieved soil). Survival data were compared with those obtained during a field release. The intact soil core microcosm was shown to closely simulate results obtained in the field. The intact soil core microcosm closely predicts survival in bulk soil and in the rhizosphere of wheat. Data obtained with the microcosm were also similar when evaluated in separate studies in two different years. In 1993, P. aureofaciens survived for approximately 63 days in bulk soil and 96 days in the rhizosphere. The disturbed soil microcosm exhibited a much more rapid decline in population size (34 days to zero) than the intact core microcosm. We speculate that drying and sieving of soil for the disturbed soil microcosm affected the ability of the soil to support the survival of P. aureofaciens. These results demonstrate that a small, inexpensive, and simple intact soil core microcosm may be appropriate for risk assessment.

Pseudomonas aureofaciens in soil: survival and recovery efficiency.

Efficient methods for the recovery of genetically engineered organisms (GEM) added to soil are critical if the safety of potential releases is to be evaluated and the actual release is to be monitored. Pseudomonas aureofaciens strain 3732 RN-L11 (lacZY) was added to 10 g sieved soil microcosms and incubated for 5 and 28 days. Various diluents, shaking methods, and settling of soil were examined to determine the optimum method for recovery of the GEM from the soil. Of the diluents examined, 0.1% agar gave significantly lower numbers than distilled water, 1.0% sodium metaphosphate, 1% peptone, and phosphate-buffered water. After 5 days of incubation, shaking for 10 min with glass beads and shaking for 30 min without glass beads resulted in the highest recovery of the GEM from soil, while sonification resulted in the lowest recovery. After 28 days of incubation, sonification produced significantly lower numbers than any of the other treatments. The addition of 1% CaCl2 to enhance settling significantly increased recovery efficiency. Although the use of CaCl2 in distilled water and shaking for 10 min was an effective method for recovering P. aureofaciens from a Maryland soil, when the same extraction procedure was compared with a standard technique (dd H2O, shaking for 10 min) for eight divergent soils, neither extraction method was consistently better than the other. Statistical analysis of the data showed the need for log transformation of the raw data. Four microcosm and two plate replicates for each dilution provided the greatest ability to detect differences between treatment means while maximizing experimental efficiency.

Swimming-associated gastroenteritis and water quality.

A direct, linear relationship between swimming-associated gastrointestinal illness and the quality of the bathing water was obtained from a multi-year, multiple-location prospective epidemiologic-microbiologic research program conducted in New York City, 1973-1975, Lake Pontchartrain, Louisiana, 1977-1978, and Boston, Massachusetts, 1978. Several microbial indicators were used in attempting to define the quality of the water; and, of those examined, enterococci showed the best correlation to total and "highly credible" gastrointestinal symptoms. The frequency of gastrointestinal symptoms also had a high degree of association with distance from known sources of municipal wastewater. A striking feature of the relationship was the very low enterococcus and Escherichia coli densities in the water (10/100 ml) associated with appreciable attack rates (about 10/1000 persons) for "highly credible" gastrointestinal symptoms. Moreover, the ratio of the swimmer to nonswimmer symptom rates indicated that swimming in even marginally polluted marine bathing water is a significant route of transmission for the observed gastroenteritis.

Quantitative procedure for enumeration of bifidobacteria.

A membrane filter technique has been developed for the enumeration of bifidobacteria in natural aquatic environments. The technique is quantitative, selective, and differential. The medium (YN-6) contains: yeast extract, 2.0 g; agar, 1.5 g; polypeptone peptone, 1.0 g; vitamin-free Casamino Acids, 0.8 g; sodium chloride, 0.32 g; and L-cysteine hydrochloride, 0.003 g; in 100 ml of deionized water. The medium is adjusted to pH 7.0 before autoclaving. Nalidixic acid (80 micrograms/ml), neomycin sulfate (2.5 micrograms/ml), and bromcresol green (300 micrograms/ml) are included as selective and differential agents. After incubation for 48 h at 37 degrees C in an anaerobic environment, Gram-stained smears from green, glistening, smooth entire colonies are examined microscopically for typical bifidobacterial morphology. No significant difference in recoveries was observed when YN-6 was compared with reinforced clostridial agar, using bifidobacteria freshly isolated from feces and raw sewage. Using this technique with aquatic and fecal samples, less than 9% false-positive and 8% false-negative isolates were observed. These results indicated that the medium was able to satisfactorily recover organisms from a variety of situations.