Cognitive function and delirium following sevoflurane or propofol anesthesia for valve replacement surgery: A multicenter randomized controlled trial.

Cognitive dysfunction is a common postoperative neurological complication in patients undergoing valve replacement surgery. This study aimed to compare the effects of sevoflurane versus propofol-based total intravenous anesthesia on the incidence of cognitive dysfunction following valve replacement surgery. This multicenter, randomized, controlled double-blinded study was conducted in three teaching hospitals in China. Patients receiving on-pump valve replacement surgery were enrolled. Stratified block randomization was used to randomly assign patients 1:1 to receive sevoflurane (1.0-1.5 MAC) or propofol (2.0-3.0 mg/kg/h) for anesthesia maintenance. The primary outcome was the incidence of cognitive dysfunction assessed by four cognitive tests before, as well as 7-14 days after surgery. Patients were randomly assigned to receive sevoflurane anesthesia (n = 144) or propofol-based total intravenous anesthesia (n = 145). The incidence of postoperative cognitive dysfunction in the sevoflurane anesthesia group (31.9%) was significantly lower than that in the total intravenous anesthesia group (43.4%; relative risk 0.61, 95% confidence interval [CI]: 0.38-0.97, p = 0.044). There was no difference in the incidence of delirium between patients receiving sevoflurane and total intravenous anesthesia (27.8% [35/144] vs. 25.9% [35/145], 1.10, 95% CI: 0.64 to 1.90, p = 0.736). There was a significant difference in the Katz Index on day 3 after surgery (3 [0.9) vs. 3 (1.0], 0.095, 95% CI: 0.05 to 0.43, p = 0.012). No difference was observed in other outcomes between the two groups. For patients undergoing on-pump valve replacement surgery, sevoflurane anesthesia had a smaller effect on cognitive function and independence in daily life activities compared with propofol anesthesia.

The sucrose-trehalose 6-phosphate (Tre6P) nexus: specificity and mechanisms of sucrose signalling by Tre6P.

Trehalose 6-phosphate (Tre6P), the intermediate of trehalose biosynthesis, has a profound influence on plant metabolism, growth, and development. It has been proposed that Tre6P acts as a signal of sugar availability and is possibly specific for sucrose status. Short-term sugar-feeding experiments were carried out with carbon-starved Arabidopsis thaliana seedlings grown in axenic shaking liquid cultures. Tre6P increased when seedlings were exogenously supplied with sucrose, or with hexoses that can be metabolized to sucrose, such as glucose and fructose. Conditional correlation analysis and inhibitor experiments indicated that the hexose-induced increase in Tre6P was an indirect response dependent on conversion of the hexose sugars to sucrose. Tre6P content was affected by changes in nitrogen status, but this response was also attributable to parallel changes in sucrose. The sucrose-induced rise in Tre6P was unaffected by cordycepin but almost completely blocked by cycloheximide, indicating that de novo protein synthesis is necessary for the response. There was a strong correlation between Tre6P and sucrose even in lines that constitutively express heterologous trehalose-phosphate synthase or trehalose-phosphate phosphatase, although the Tre6P:sucrose ratio was shifted higher or lower, respectively. It is proposed that the Tre6P:sucrose ratio is a critical parameter for the plant and forms part of a homeostatic mechanism to maintain sucrose levels within a range that is appropriate for the cell type and developmental stage of the plant.

A mediator of singlet oxygen responses in Chlamydomonas reinhardtii and Arabidopsis identified by a luciferase-based genetic screen in algal cells.

All cells produce reactive oxygen species (ROS) as by-products of their metabolism. In addition to being cytotoxic, ROS act as regulators of a wide range of developmental and physiological processes. Little is known about the molecular mechanisms underlying the perception of ROS and initiation of cellular responses in eukaryotes. Using the unicellular green alga Chlamydomonas reinhardtii, we developed a genetic screen for early components of singlet oxygen signaling. Here, we report the identification of a small zinc finger protein, methylene blue sensitivity (MBS), that is required for induction of singlet oxygen-dependent gene expression and, upon oxidative stress, accumulates in distinct granules in the cytosol. Loss-of-function mbs mutants produce singlet oxygen but are unable to fully respond to it at the level of gene expression. Knockout or knockdown of the homologous genes in the higher plant model Arabidopsis thaliana results in mutants that are hypersensitive to photooxidative stress, whereas overexpression produces plants with elevated stress tolerance. Together, our data indicate an important and evolutionarily conserved role of the MBS protein in ROS signaling and provide a strategy for engineering stress-tolerant plants.

[A survey of normal reference ranges of tenderness threshold in healthy undergraduates].

OBJECTIVE: To analyze the profiles of pressure pain threshold (PPT) and pressure pain tolerance (PTO) of healthy undergraduates so as to establish the normal reference ranges of PPT and PTO. METHODS: The levels of PPT and PTO were measured at lateral brachioradialis of lateral elbow joint with a pressure algometer in 113 healthy undergraduates. Then the influencing factors of tenderness thresholds were analyzed and the normal reference ranges of PPT and PTO established. RESULTS: The females exhibited a lower PPT than the males (P < 0.01). And the gender differences of PTO were statistically insignificant (P > 0.05). Meanwhile, there was no significant difference in either PPT or PTO between the right and left sides (P > 0.05). The normal reference ranges (kg/cm(2)) of PPT and PTO were obtained at the measuring spot of all subjects. As a result, the ranges of PPT were 1.19 - 4.63 in the males and 0.37 - 3.63 in the females. And the range of PTO was 1.80 - 8.50 in all subjects. CONCLUSION: This survey establishes the normal reference ranges of tenderness thresholds at the specific measuring spot for some specific population. These ranges may serve as a reference for the sensitivity of individual tenderness safely, accurately and simply.

[The human variome project and its progress].

The main goal of post genomics is to explain how the genome, the map of which has been constructed in the Human Genome Project, affacts activities of life. This leads to generate multiple "omics": structural genomics, functional genomics, proteomics, metabonomics, et al. In Jun. 2006, Melbourne, Australia, Human Genome Variation Society (HGVS) initiated the Human Variome Project (HVP) to collect all the sequence variation and polymorphism data worldwidely. HVP is to search and determine those mutations related with human diseases by association study between genetype and phenotype on the scale of genome level and other methods. Those results will be translated into clinical application. Considering the potential effects of this project on human health, this paper introduced its origin and main content in detail and discussed its meaning and prospect.

Prediction of function changes associated with single-point protein mutations using support vector machines (SVMs).

Computational methods can be used to predict the effects of single amino acid substitutions (single-point mutations). In contrast to previous methods that need many protein sequence and structural features, we applied support vector machines (SVMs) to predict protein function changes associated with amino acid substitutions using only sequence information, and cross-validated them on a large dataset extracted from the Protein Mutant Database (PMD). By three SVM classifiers, we investigated three local sequence features of proteins (residue composition, hydrophobic interaction, and evolutionary property), and examined their effects on the prediction accuracy. As a main result, a novel SVM named substitution-matrix-based kernel SVM was constructed to make speedy and accurate prediction, and its value was shown in an application case. Furthermore, our findings confirmed results from other studies.