Chronic Atypical Antipsychotic Use Is Associated With Reduced Need for Postoperative Nausea and Vomiting Rescue in the Postanesthesia Care Unit: A Propensity-Matched Retrospective Observational Study.

BACKGROUND: Atypical antipsychotics are efficacious for chemoprophylaxis against chemotherapy-induced nausea and vomiting, but perioperative investigations have been scant. We sought to examine the association between chronic atypical antipsychotic therapy and the likelihood of postoperative nausea and vomiting. METHODS: In this single-center, propensity-matched, retrospective, observational study, elective noncardiac surgical cases from January 2014 to December 2017 were examined with regard to the primary outcome of rescue antiemetic administration in the postanesthesia care unit as a measure of postoperative nausea and vomiting. Chronic administration of olanzapine, aripiprazole, and risperidone was the exposure of interest. Other independent variables included outpatient antiemetics, modified Apfel score, age, American Society of Anesthesiologists physical status score, case length, and exposures to emetogenic and chemoprophylactic agents. Logistic regression was performed using case-level data. Conditional logistic regression was performed after 1:2 propensity matching, sampling without replacement. Monte Carlo simulation was performed to compute the mean patient-level treatment effect on the treated. RESULTS: Of 13,660 cases, 154 cases with patients receiving atypical antipsychotics were matched against 308 cases without, representing 115 and 273 unique patients, respectively. In a well-balanced cohort, the mean patient-level odds of being administered rescue antiemetic was lower for patients chronically taking the 3 atypical antipsychotics under consideration as compared to those not on atypical antipsychotics, with an odds ratio of 0.29 (95% CI, 0.11-0.75; P = .015). CONCLUSIONS: Chronic atypical antipsychotic therapy is associated with reduced risk of postanesthesia care unit antiemetic administration. These findings support the need for prospective studies to establish the safety and efficacy of postoperative nausea and vomiting chemoprophylaxis with these agents.

Isoprene synthase genes form a monophyletic clade of acyclic terpene synthases in the TPS-B terpene synthase family.

Many plants emit significant amounts of isoprene, which is hypothesized to help leaves tolerate short episodes of high temperature. Isoprene emission is found in all major groups of land plants including mosses, ferns, gymnosperms, and angiosperms; however, within these groups isoprene emission is variable. The patchy distribution of isoprene emission implies an evolutionary pattern characterized by many origins or many losses. To better understand the evolution of isoprene emission, we examine the phylogenetic relationships among isoprene synthase and monoterpene synthase genes in the angiosperms. In this study we identify nine new isoprene synthases within the rosid angiosperms. We also document the capacity of a myrcene synthase in Humulus lupulus to produce isoprene. Isoprene synthases and (E)-ß-ocimene synthases form a monophyletic group within the Tps-b clade of terpene synthases. No asterid genes fall within this clade. The chemistry of isoprene synthase and ocimene synthase is similar and likely affects the apparent relationships among Tps-b enzymes. The chronology of rosid evolution suggests a Cretaceous origin followed by many losses of isoprene synthase over the course of evolutionary history. The phylogenetic pattern of Tps-b genes indicates that isoprene emission from non-rosid angiosperms likely arose independently.

Biochemical characterization and homology modeling of methylbutenol synthase and implications for understanding hemiterpene synthase evolution in plants.

2-Methyl-3-buten-2-ol (MBO) is a five-carbon alcohol produced and emitted in large quantities by many species of pine native to western North America. MBO is structurally and biosynthetically related to isoprene and can have an important impact on regional atmospheric chemistry. The gene for MBO synthase was identified from Pinus sabiniana, and the protein encoded was functionally characterized. MBO synthase is a bifunctional enzyme that produces both MBO and isoprene in a ratio of ~90:1. Divalent cations are required for activity, whereas monovalent cations are not. MBO production is enhanced by K(+), whereas isoprene production is inhibited by K(+) such that, at physiologically relevant [K(+)], little or no isoprene emission should be detected from MBO-emitting trees. The K(m) of MBO synthase for dimethylallyl diphosphate (20 mm) is comparable with that observed for angiosperm isoprene synthases and 3 orders of magnitude higher than that observed for monoterpene and sesquiterpene synthases. Phylogenetic analysis showed that MBO synthase falls into the TPS-d1 group (gymnosperm monoterpene synthases) and is most closely related to linalool synthase from Picea abies. Structural modeling showed that up to three phenylalanine residues restrict the size of the active site and may be responsible for making this a hemiterpene synthase rather than a monoterpene synthase. One of these residues is homologous to a Phe residue found in the active site of isoprene synthases. The remaining two Phe residues do not have homologs in isoprene synthases but occupy the same space as a second Phe residue that closes off the isoprene synthase active site.

Photosynthetic recovery following desiccation of desert green algae (Chlorophyta) and their aquatic relatives.

Recent molecular data suggest that desert green algae have evolved from freshwater ancestors at least 14 times in three major classes (Chlorophyceae, Trebouxiophyceae and Charophyceae), offering a unique opportunity to study the adaptation of photosynthetic organisms to life on land in a comparative phylogenetic framework. We examined the photorecovery of phylogenetically matched desert and aquatic algae after desiccation in darkness and under illumination. Desert algae survived desiccation for at least 4 weeks when dried in darkness, and recovered high levels of photosynthetic quantum yield within 1 h of rehydration in darkness. However, when 4 weeks of desiccation was accompanied by illumination, three of six desert taxa lost their ability to recover quantum yield during rehydration in the dark. Aquatic algae, in contrast, recovered very little during dark rehydration following even just 24 h of desiccation. Re-illuminating rehydrated algae produced a nearly complete recovery of quantum yield in all desert and two of five aquatic taxa. These contrasts provide physiological evidence that desert green algae possess mechanisms for photosynthetic recovery after desiccation distinct from those in aquatic relatives, corroborating molecular evidence that they are not happenstance, short-term visitors from aquatic environments. Photosensitivity during desiccation among desert algae further suggests that they may reside in protected microsites within crusts, and species specificity of photosensitivity suggests that disturbances physically disrupting crusts could lead to shifts or losses of taxonomic diversity within these habitats.

Thermal history regulates methylbutenol basal emission rate in Pinus ponderosa.

Methylbutenol (MBO) is a 5-carbon alcohol that is emitted by many pines in western North America, which may have important impacts on the tropospheric chemistry of this region. In this study, we document seasonal changes in basal MBO emission rates and test several models predicting these changes based on thermal history. These models represent extensions of the ISO G93 model that add a correction factor C(basal), allowing MBO basal emission rates to change as a function of thermal history. These models also allow the calculation of a new emission parameter E(standard30), which represents the inherent capacity of a plant to produce MBO, independent of current or past environmental conditions. Most single-component models exhibited large departures in early and late season, and predicted day-to-day changes in basal emission rate with temporal offsets of up to 3 d relative to measured basal emission rates. Adding a second variable describing thermal history at a longer time scale improved early and late season model performance while retaining the day-to-day performance of the parent single-component model. Out of the models tested, the T(amb),T(max7) model exhibited the best combination of day-to-day and seasonal predictions of basal MBO emission rates.

Simultaneous collection of rapid chlorophyll fluorescence induction kinetics, fluorescence quenching parameters, and environmental data using an automated PAM-2000/CR10X data logging system.

The PAM-2000 portable chlorophyll fluorometer represents one of the first commercially available instruments utilizing the Pulse Amplitude Modulation (PAM) measurement principle, and has become a widely used platform for measuring chlorophyll fluorescence in a wide range of study systems. In this paper, we describe a new method for externally driving and gathering data from the PAM-2000, a method that allows the user to execute a pre-defined user run (or runs) and capture (1) rapid induction kinetics (at 2 ms frequency) during all saturating pulses, (2) measures of F, F(o), F(o)', F(m), and F(m)' associated with those same pulses, and (3) changes in fluorescence F at user-defined intervals between pulses, for the entire user run, with all data compressed into a single, manageable data logger file. Practically, the method makes possible, for example, a post-hoc evaluation of the appropriateness of saturation pulse lengths and intensities during a user run. More importantly it captures, during entire user runs, the varied information contained in slow changes in fluorescence between saturating pulses, as well as rapid induction kinetics, quenching coefficients and quantum yields all gathered simultaneously from all saturating flashes.

Jasmonic acid induces rapid changes in carbon transport and partitioning in Populus.

Here, we tested whether rapid changes in carbohydrate transport and partitioning to storage organs would be induced by jasmonic acid (JA), a plant-produced signal of herbivore attack known to induce resistance. Carbon-11, introduced as (11)CO(2), was used to track real-time carbohydrate transport and partitioning nondestructively in Populus species before and 12 h after application of JA to a single leaf. Jasmonic acid resulted in more rapid [(11)C]-photosynthate export from both local and systemic leaves, as well as greater partitioning of [(11)C]-photosynthate to the stem and roots. In Populus tremuloides, following JA treatment, leaf starch decreased, but there was no change in photosynthetic rates or leaf soluble sugar concentration, indicating that recent photosynthate was diverted from starch accumulation in the leaf to other plant organs. Increasing the supply of photosynthate to roots and stems may shield resources from folivorous predators, and may also facilitate both storage and nutrient uptake, and ultimately lead to greater tolerance, either by enhancing regrowth capacity or by replacing nutrients consumed by herbivores.

Turgor, solute import and growth in maize roots treated with galactose.

It has been observed that extension growth in maize roots is almost stopped by exposure to 5 mm d-galactose in the root medium, while the import of recent photoassimilate into the entire root system is temporarily promoted by the same treatment. The aim of this study was to reconcile these two apparently incompatible observations. We examined events near the root tip before and after galactose treatment since the tip region is the site of elongation and of high carbon deposition in the root. The treatment rapidly decreased root extension along the whole growing zone. In contrast, turgor pressure, measured directly with the pressure probe in the cortical cells of the growing zone, rapidly increased by 0.15 MPa within the first hour following treatment, and the increase was maintained over the following 24 h. Both tensiometric measurements and a comparison of turgor pressure with local growth rate demonstrated that a rapid tightening of the cell wall caused the reduction in growth. Single cell sampling showed cell osmotic pressure increased by 0.3 MPa owing to accumulation of both organic and inorganic solutes. The corresponding change in cell water potential was a rise from -0.18 MPa to approximately zero. More mature cells at 14 mm from the root tip (just outside the growing region) showed a qualitatively similar response.

Field response of Ips paraconfusus, Dendroctonus brevicomis, and their predators to 2-methyl-3-buten-2-ol, a novel alcohol emitted by ponderosa pine.

Methylbutenol (MBO) is a major component of the aggregation pheromone of the European spruce beetle Ips typographus and also has been found to be emitted in large amounts by several species of pine native to western North America. This study investigates the influence this signal may have on the behavior of North American bark beetles and examines whether MBO functions as a defensive compound for emitting pines. The response of two North American bark beetles (Ips paraconfusus and Dendroctonus brevicomis) and their predaceous beetles (Trogositidae and Cleridae) to MBO, pheromone, and monoterpenes in varying release rates was investigated in the field using Lindgren funnel traps. MBO exhibited no repellent properties when tested alone, nor did MBO appear to have any effect on the aggregation response of these bark beetles and their predators to their pheromones. These results provide no support for a defensive function of MBO.

Altitudinal variation for senescence in Melanoplus grasshoppers.

We describe differences in senescence among populations of grasshoppers that occur along an altitudinal gradient in the Sierra Nevada, California. Experimental males from five populations of the Melanoplus sanguinipes/devastator sibling species complex were reared in each of two thermal culture conditions from eggs of field-caught females. In both culture conditions, we measured the survival of adult cohorts from each population. Differences in the physiological capacity to survive in a sheltered, common environment reveal genetic differences in underlying rates of senescence, providing maternal effects do not affect the rate of aging in offspring. At each temperature, mortality rates increased as a function of age, which indicates that senescence occurs under laboratory conditions. Within each culture condition, cohorts originating from low-elevation populations had greater survival than did cohorts from high elevations. Variation in body size along the altitudinal gradient did not account for the differences in survival. We suggest that high-elevation populations have evolved accelerated senescence as a direct or an indirect result of selection on reproductive schedules, which are potentially truncated by severe winter conditions at the elevated sites.