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.

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.

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.

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.

A histochemical and electron microscopic study of a fast- and a slow-twitch muscle in genetically spastic mice.

Fast and slow muscle fibers were studied in the flexor digitorum longus (FDL) and soleus (SOL) muscles, respectively, in control and spastic mice. HIstochemical and electron microscopic studies indicated an increased number of mitochondria, a decreased deposition of glycogen and a vesiculation and distension of the sarcoplasmic reticulum in many fast-twitch fibers of the spastic FDL. Similar findings were not evident in the slow-twitch fibers of the spastic SOL. Since the spastic condition causes increased muscular activity as a result of more rapid and prolonged nerve impulse firing, these findings reinforce the idea that a muscle fiber's oxidative capabilities are a function of its activity.

Membrane filter technique for enumeration of Pseudomonas aeruginosa.

A membrane filter procedure for the quantitation of Pseudomonas aeruginosa (mPA procedure) has been developed. Through the use of inhibitors and an elevated incubation temperature, the level of background microbial flora was decreased approximately 10,000-fold. Using P. aeruginosa cells suspended in sea water and held for 24 hr, between 70 and 100% of the "viable" cells could be recovered by the mPA procedure. Assay variability was found to be insignificant. The recoveries of P. aeruginosa from surface (fresh and salt) waters, potable waters, and sewage by the mPA procedure exceeded those obtainable by current methods. Subsequent to its development and evaluation, the mPA procedure was used at three other laboratories for the enumeration of P. aeruginosa in potable and recreational waters and in sewage samples. It was found amenable to routine use, and confirmation of typical colonies approached 100%.

Quantitative method for enumeration of enterotoxigenic Escherichia coli.

A rapid method was developed to quantify toxigenic Escherichia coli, using a membrane filter procedure. After filtration of samples, the membrane filter was first incubated on a medium selective for E. coli (24 h, 44 degrees C) and then transferred to tryptic soy agar (3%; 6 h, 37 degrees C). To assay for labile toxin-producing colonies, the filter was then transferred to a monolayer of Y-1 cells, the E. coli colonies were marked on the bottom of the petri dish, and the filter was removed after 15 min. The monolayer was observed for a positive rounding effect after a 15- to 24-h incubation. The method has an upper limit of detecting 30 toxigenic colonies per plate and can detect as few as one toxigenic colony per plate. A preliminary screening for these enterotoxigenic strains in polluted waters and known positive fecal samples was performed, and positive results were obtained with fecal samples only.

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.

Assessment of bifidobacteria as indicators of human fecal pollution.

The distribution of bifidobacteria in the environment has been examined by using YN-6 medium. Although feces of humans, chickens, cows, dogs, pigs, horses, cats, sheep, beavers, goats, and turkeys were examined, bifidobacteria were isolated only from the feces of humans and swine. The frequency and distribution of component species of human fecal isolates were as in isolates from raw sewage. Bifidobacterium longum and B. adolescentis were most often isolated and in the highest densities. The levels of bifidobacteria in raw sewage were in the range of 10(6) organisms/100 ml, and the effect of primary and secondary sewage treatment on the number of viable organisms present was not significant. High densities of bifidobacteria were found in all samples from septic tanks. It was found that bifidobacteria did not survive as well as Escherichia coli in either fresh or marine waters. The ratio of bifidobacteria to E. coli is an indication of the age and of the effectiveness of treatment of sewage effluent.

Quantitative large-volume sampling technique.

A filtration technique for high-volume sampling of water has been developed that, when combined with the most probable number procedure, permits the quantitation of microorganisms present at very low densities.

Neural-tube defects caused by 5-bromodeoxyuridine in chicks.

Chick embryos were explanted at HH stage 4 and cultured for 24 h on thin albumen with 10 mug/ml 5-bromodeoxyuridine (BrdU). BrdU inhibited closure of the neural tube in over 90% of the embryos. Mitotic figures were found throughout adversely effected neuroepithelium, suggesting that interkinetic nuclear migration had been inhibited. Electron microscopic studies of BrdU-treated neural-tube cells showed fewer and more amorphous cytoplasmic extensions, microfilaments, and demosomal (juctional) tonofibrils than in controls, but microtubules were unaffected.

Membrane filter technique for enumeration of enterococci in marine waters.

A membrane filter procedure is described for the enumeration of enterococci in marine waters. The procedure utilizes a highly selective and somewhat differential primary isolation medium followed by an in situ substrate test for identifying colonies of those organisms capable of hydrolyzing esculin. The procedure (mE) was evaluated with known streptococci strains and field samples with regard to its accuracy, sensitivity, selectivity, precision, and comparability to existing methods. Essentially quantitative recovery was obtained with seawater-stressed cells of Streptococcus faecalis and S. faecium. Neither S. bovis, S. equinus, S. mitis, nor S. salivarius grew on the medium. The selectivity of the medium was such that a 10,000-fold reduction in background organisms was obtained relative to a medium which contained no inhibitors and was incubated at 35 C. About 90% of those typical colonies designated as enterococci confirmed as such and about 12% of the colonies not so designated were, in fact, identified as enterococci. Plate to plate variability across samples approximated that expected by chance alone. Verified recoveries of enterococci from natural samples by the mE procedure, on the average, exceeded those by the KF method by one order of magnitude.

[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.