Australian anaesthetists' practice of sedation for gastrointestinal endoscopy in adult patients.

A wide spectrum of practice in sedation for gastrointestinal endoscopy in adult patients is documented overseas, but a current profile of the practice of Australian anaesthetists is unavailable. We therefore surveyed 200 Fellows of the Australian and New Zealand College of Anaesthetists on the choice of drugs and monitoring, use of analgesic throat spray and prophylactic intravenous fluids and the depth of sedation for gastrointestinal endoscopy. Our response rate was 57% and endoscopy formed a significant part of most respondents' practices. Propofol was used for almost all procedures, in combination with midazolam alone (14%), fentanyl alone (6%), midazolam and fentanyl (61%), another drug (15%) or no adjuvant (4%). The majority of patients received prophylactic intravenous fluids for endoscopic retrograde cholangio-pancreatography (83%) and colonoscopy (64%), but not for gastroscopy (20%). All patients received supplemental oxygen and monitoring with pulse oximetry. However over 20% of patients having gastroscopy or colonoscopy did not have non-invasive blood pressure monitoring. A maximum depth of sedation during which the patient was unresponsive to painful stimulation (commensurate with general anaesthesia) was targeted by 54% of respondents. Significant variations exist in the practice of sedation and monitoring for endoscopy in adult patients by anaesthetists in Australia.

Effect of myo-inositol(1,4,5)trisphosphate on the hydrolysis of phytic acid by phytase.

Phytase is a monomeric enzyme of molecular mass 160 kDa which catalyzes the hydrolysis of phytic acid (D-myo inositol hexakisphosphate, InsP6) in a stepwise manner to myo-inositol. The enzyme-InsPn (n = 1-6) interaction at the catalytic site has a dissociation constant in the micro molar range. There also exists in the enzyme, a non-catalytic site specific for InsP3 with dissociation constant in the nano molar range. We have probed the effect of the high affinity InsP3 binding on the dissociation constant (Kd) of the phytase-InsP6 interaction and the kinetics of hydrolysis. These studies demonstrate the effect exerted by the high affinity InsP3 binding on the catalytic site of the enzyme.

High affinity association of myo-inositol trisphosphates with phytase and its effect upon the catalytic potential of the enzyme.

A neutral phytase from germinating mung bean (Vigna radiata) seeds dephosphorylates myo-inositol hexakisphosphate sequentially to myo-inositol. The enzyme also binds with higher affinity to myo-inositol trisphosphates (1,4,5), (2,4,5), and (1,3,4) isomers without catalysis. The high affinity complex elicits Ca(2+) mobilization in vitro from microsomes/vacuoles via the formation of a ternary complex with the receptor for Ins(1,4,5)P(3). As a sequel to our previous report, we have carried out a detailed characterization of the two sites and examined the mutual interactions between them. Presaturation of the high affinity site leads to an increase in the affinity of the enzyme for phytic acid and its rate of dephosphorylation as well. From the products of limited tryptic cleavage of phytase, two peptides, each with one activity, have been isolated. The larger peptide ( approximately 66 kDa) contains the catalytic site, and the smaller peptide ( approximately 5 kDa) has the high affinity myo-inositol trisphosphate-binding site. The interaction between the dual activities of phytase has been observed also at the level of the two peptides. A sequence homology search using N-terminal 12 amino acid residues of the 5-kDa fragment has revealed significant homology with the Homer class of proteins implicated in signaling pathways involving metabotropic glutamate receptor and myo-inositol 1,4,5-trisphosphate receptor. These results indicate a second role of phytase in Ca(2+) mobilization during germination of mung been seed via a salvage pathway that involves allosteric activation by myo-inositol trisphosphate.

Complete nucleotide sequence of clover yellow mosaic virus RNA.

The entire genomic RNA of clover yellow mosaic virus was sequenced from cDNA clones and run-off cDNA transcripts. The genomic RNA is 7015 nucleotides in length [excluding a 3' poly(A) tail], with six open reading frames (ORFs) greater than 150 nucleotides in length. The first five ORFs encode proteins of Mr 191K, 26K, 12K, 6.5K and 28K, respectively. The sixth ORF lies completely within ORF1 and codes for a protein of Mr 14K. The capsid protein coding region (Mr 23K) is found within ORF5 which encodes the Mr 28K protein. Proteins encoded by ORFs 1 to 3 and ORF5 show strong homology with proteins of other potexviruses, especially papaya mosaic virus.

The kinetic complexity of Acetabularia chloroplast DNA.

The kinetic complexity of Acetabularia cliftonii chloroplast DNA is 1.52 +/- 0.26 . 10(9) daltons, compared to 0.2 .10(9) daltons for Chlamydomonas chloroplast DNA. There is an average of three genomes per chloroplast. The unusually large size of the Acetabularia genome may reflect the ancient evolutionary history of this organism.

Metabolism and distribution of cyclohexanecarboxylic Acid, a plant growth stimulant, in bush bean.

A foliar spray of 10 mm cyclohexanecarboxylic acid (CHC), a component of the growth stimulant naphthenic acid, to primary leaves of 14-day-old plants of bush bean, Phaseolus vulgaris L., cv Top Crop, resulted in increased vegetative growth and pod production. One minute after the application of 0.5 mm CHC-7-(14)C (CHC(*)) to a primary leaf, CHC(*) was present within it. The chief conversion of the CHC(*) in the leaf during the interval 15 minutes to 4 hours after the acid had been applied appeared to be CHC(*) to its glucose conjugate (CHC(*)-G), and during 4 to 48 hours, CHC(*)-G to CHC(*)-aspartate and an unknown metabolite. Radioactivity was confined to the leaf for at least 1 hour, but by the 12th hour was detected throughout the plant. In the interval 1 to 4 weeks after CHC(*) application, the mean percentage distribution of radioactivity was: treated leaf, 65.3; roots, 18.8; stem, 7.7; trifoliate leaves, 5.9; flower buds-flowers-pods, 2.3. During this period CHC(*)-G was the most prominent metabolite in all organs; no free CHC(*) was detected. Light favored the movement of CHC(*) conjugates out of the leaf; glucose fed to dark-grown plants substituted for light to some extent but aspartate was relatively ineffective, suggesting the dependence of outward movement on ATP. The presence of the glucose and aspartate conjugates of the acid in all organs of CHC-treated plants and the absence of free CHC from them suggest that one or both conjugates, rather than the acid itself, are involved in growth stimulation.