Comparative genomics of the eukaryotes

A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.

The Berkeley Drosophila Genome Project gene disruption project: Single P-element insertions mutating 25% of vital Drosophila genes

A fundamental goal of genetics and functional genomics is to identify and mutate every gene in model organisms such as Drosophila melanogaster. The Berkeley Drosophila Genome Project (BDGP) gene disruption project generates single P-element insertion strains that each mutate unique genomic open reading frames. Such strains strongly facilitate further genetic and molecular studies of the disrupted loci, but it has remained unclear if P elements can be used to mutate all Drosophila genes. We now report that the primary collection has grown to contain 1045 strains that disrupt more than 25% of the estimated 3600 Drosophila genes that are essential for adult viability. Of these P insertions, 67% have been verified by genetic tests to cause the associated recessive mutant phenotypes, and the validity of most of the remaining lines is predicted on statistical grounds. Sequences flanking >920 insertions have been determined to exactly position them in the genome and to identify 376 potentially affected transcripts from collections of EST sequences. Strains in the BDGP collection are available from the Bloomington Stock Center and have already assisted the research community in characterizing >250 Drosophila genes. The likely identity of 131 additional genes in the collection is reported here. Our results show that Drosophila genes have a wide range of sensitivity to inactivation by P elements, and provide a rationale for greatly expanding the BDGP primary collection based entirely on insertion site sequencing. We predict that this approach can bring >85% of all Drosophila open reading frames under experimental control.

The normal glenohumeral relationships. An anatomical study of one hundred and forty shoulders

We measured the dimensions of the humeral and glenoid articular surfaces in 140 shoulders that were representative of a given population of patients, and also evaluated several glenohumeral relationships. Ninety-six measurements were made in the shoulders of cadavera and forty-four, on magnetic resonance-imaging studies of living patients. Eighty-five per cent of the humeral measurements fell within eight fixed combinations of the radius of curvature and the thickness of the humeral head, in two-millimeter increments. The average radius of curvature of the humeral head in the coronal plane was 24 +/- 2.1 millimeters (range, nineteen to twenty-eight millimeters). The average thickness of the humeral head was 19 +/- 2.4 millimeters (range, fifteen to twenty-four millimeters). There was a wide variability in the size of the humeral head and a direct correlation between the differences in size and the heights in both men and women. The humeral articular surface was spherical in the center; however, the peripheral radius was two millimeters less in the axial plane than in the coronal plane. Thus, the peripheral contour of the articular surface was elliptical (ratio, 0.92). The radius of curvature of the glenoid, measured in the coronal plane, was an average of 2.3 +/- 0.2 millimeters greater than that of the humeral head. The average dimensions of the glenoid in the superior-inferior and anterior-posterior (lower half) directions were 39 +/- 3.5 millimeters (range, thirty to forty-eight millimeters) and 29 +/- 3.2 millimeters (range, twenty-one to thirty-five millimeters). The anterior-posterior dimension of the glenoid was pear-shaped, the lower half being larger than the top half. The ratio of the lower half to the top half was 1:0.80 +/- 0.01. There was a strong linear correlation between the lateral humeral offset and the size of the humeral head (radius of curvature and thickness). The average lateral humeral offset was 56 +/- 5.7 millimeters (range, forty-three to sixty-seven millimeters). The superior most point on the humeral articular surface was an average of 8 +/- 3.2 millimeters (range, three to twenty millimeters) cephalad to the top of the greater tuberosity. Our data show that reconstruction of the lateral humeral offset is important in optimization of the moment arm of the deltoid and rotator cuff and of the normal tension of the soft tissue after prosthetic reconstruction.

Apollo: a sequence annotation editor

The well-established inaccuracy of purely computational methods for annotating genome sequences necessitates an interactive tool to allow biological experts to refine these approximations by viewing and independently evaluating the data supporting each annotation. Apollo was developed to meet this need, enabling curators to inspect genome annotations closely and edit them. FlyBase biologists successfully used Apollo to annotate the Drosophila melanogaster genome and it is increasingly being used as a starting point for the development of customized annotation editing tools for other genome projects.

Milk derived bioactive peptides and their impact on human health - A review

Milk-derived bioactive peptides have been identified as potential ingredients of health-promoting functional foods. These bioactive peptides are targeted at diet-related chronic diseases especially the non-communicable diseases viz., obesity, cardiovascular diseases and diabetes. Peptides derived from the milk of cow, goat, sheep, buffalo and camel exert multifunctional properties, including anti-microbial, immune modulatory, anti-oxidant, inhibitory effect on enzymes, anti-thrombotic, and antagonistic activities against various toxic agents. Majority of those regulate immunological, gastrointestinal, hormonal and neurological responses, thereby playing a vital role in the prevention of cancer, osteoporosis, hypertension and other disorders as discussed in this review. For the commercial production of such novel bioactive peptides large scale technologies based on membrane separation and ion exchange chromatography methods have been developed. Separation and identification of those peptides and their pharmacodynamic parameters are necessary to transfer their potent functional properties into food applications. The present review summarizes the preliminary classes of bioactive milk-derived peptides along with their physiological functions, general characteristics and potential applications in health-care.

Crystal structure of a phosphatidylinositol 3-phosphate-specific membrane-targeting motif, the FYVE domain of Vps27p

Phosphatidylinositol 3-phosphate regulates membrane trafficking and signaling pathways by interacting with the FYVE domains of target proteins. The 1.15 A structure of the Vps27p FYVE domain reveals two antiparallel beta sheets and an alpha helix stabilized by two Zn2+-binding clusters. The core secondary structures are similar to a rabphilin-3A Zn2+-binding domain and to the C1 and LIM domains. Phosphatidylinositol 3-phosphate binds to a pocket formed by the (R/K)(R/K)HHCR motif. A lattice contact shows how anionic ligands can interact with the phosphatidylinositol 3-phosphate-binding site. The tip of the FYVE domain has basic and hydrophobic surfaces positioned so that nonspecific interactions with the phospholipid bilayer can abet specific binding to phosphatidylinositol 3-phosphate.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Signaling and subcellular targeting by membrane-binding domains

Protein kinase C homology-1 and -2, FYVE, and pleckstrin homology domains are ubiquitous in eukaryotic signal transduction and membrane-trafficking proteins. These domains regulate subcellular localization and protein function by binding to lipid ligands embedded in cell membranes. Structural and biochemical analysis of these domains has shown that their molecular mechanisms of membrane binding depend on a combination of specific and nonspecific interactions with membrane lipids. In vivo studies of green fluorescent protein fusions have highlighted the key roles of these domains in regulating protein localization to plasma and internal membranes in cells.

An exploration of the sequence of a 2.9-Mb region of the genome of Drosophila melanogaster: the Adh region

A contiguous sequence of nearly 3 Mb from the genome of Drosophila melanogaster has been sequenced from a series of overlapping P1 and BAC clones. This region covers 69 chromosome polytene bands on chromosome arm 2L, including the genetically well-characterized "Adh region." A computational analysis of the sequence predicts 218 protein-coding genes, 11 tRNAs, and 17 transposable element sequences. At least 38 of the protein-coding genes are arranged in clusters of from 2 to 6 closely related genes, suggesting extensive tandem duplication. The gene density is one protein-coding gene every 13 kb; the transposable element density is one element every 171 kb. Of 73 genes in this region identified by genetic analysis, 49 have been located on the sequence; P-element insertions have been mapped to 43 genes. Ninety-five (44%) of the known and predicted genes match a Drosophila EST, and 144 (66%) have clear similarities to proteins in other organisms. Genes known to have mutant phenotypes are more likely to be represented in cDNA libraries, and far more likely to have products similar to proteins of other organisms, than are genes with no known mutant phenotype. Over 650 chromosome aberration breakpoints map to this chromosome region, and their nonrandom distribution on the genetic map reflects variation in gene spacing on the DNA. This is the first large-scale analysis of the genome of D. melanogaster at the sequence level. In addition to the direct results obtained, this analysis has allowed us to develop and test methods that will be needed to interpret the complete sequence of the genome of this species. Before beginning a Hunt, it is wise to ask someone what you are looking for before you begin looking for it. Milne 1926

Structure of type IIbeta phosphatidylinositol phosphate kinase: a protein kinase fold flattened for interfacial phosphorylation

Phosphoinositide kinases play central roles in signal transduction by phosphorylating the inositol ring at specific positions. The structure of one such enzyme, type IIbeta phosphatidylinositol phosphate kinase, reveals a protein kinase ATP-binding core and demonstrates that all phosphoinositide kinases belong to one superfamily. The enzyme is a disc-shaped homodimer with a 33 x 48 A basic flat face that suggests an electrostatic mechanism for plasma membrane targeting. Conserved basic residues form a putative phosphatidylinositol phosphate specificity site. The substrate-binding site is open on one side, consistent with dual specificity for phosphatidylinositol 3- and 5-phosphates. A modeled complex with membrane-bound substrate and ATP shows how a phosphoinositide kinase can phosphorylate its substrate in situ at the membrane interface.

Transgenic plants expressing cationic peptide chimeras exhibit broad-spectrum resistance to phytopathogens

Here we describe a strategy for engineering transgenic plants with broad-spectrum resistance to bacterial and fungal phytopathogens. We expressed a synthetic gene encoding a N terminus-modified, cecropin-melittin cationic peptide chimera (MsrA1), with broad-spectrum antimicrobial activity. The synthetic gene was introduced into two potato (Solanum tuberosum L.) cultivars, Desiree and Russet Burbank, stable incorporation was confirmed by PCR and DNA sequencing, and expression confirmed by reverse transcription (RT)-PCR and recovery of the biologically active peptide. The morphology and yield of transgenic Desiree plants and tubers was unaffected. Highly stringent challenges with bacterial or fungal phytopathogens demonstrated powerful resistance. Tubers retained their resistance to infectious challenge for more than a year, and did not appear to be harmful when fed to mice. Expression of msrA1 in the cultivar Russet Burbank caused a striking lesion-mimic phenotype during leaf and tuber development, indicating its utility may be cultivar specific. Given the ubiquity of antimicrobial cationic peptides as well as their inherent capacity for recombinant and combinatorial variants, this approach may potentially be used to engineer a range of disease-resistant plants.

Cytotype control of Drosophila P element transposition: the 66 kd protein is a repressor of transposase activity

Drosophila P transposable elements encode two proteins, an 87 kd transposase protein and a 66 kd protein that has been hypothesized to repress transposition. We have made germline transformants carrying modified P element derivatives that encode only the 66 kd protein and shown that these elements repress transposase activity in both the germline and the soma. The position of these elements in the genome quantitatively affected their ability to negatively regulate transposase and to express the 66 kd protein. Single 66 kd element-containing strains did not exhibit the maternal inheritance of P cytotype characteristic of P strains. However, we demonstrated that a true P strain produced higher levels of the 66 kd protein during oogenesis than single 66 kd P elements. Thus, the expression of the 66 kd repressor during oogenesis may be a major determinant of the maternal effect of P cytotype.

Mechanics of Flexible Needles Robotically Steered through Soft Tissue

The tip asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. This enables robotic needle steering, which can be used in medical procedures to reach subsurface targets inaccessible by straight-line trajectories. However, accurate path planning and control of needle steering requires models of needle-tissue interaction. Previous kinematic models required empirical observations of each needle and tissue combination in order to fit model parameters. This study describes a mechanics-based model of robotic needle steering, which can be used to predict needle behavior and optimize system design based on fundamental mechanical and geometrical properties of the needle and tissue. We first present an analytical model for the loads developed at the tip, based on the geometry of the bevel edge and material properties of soft-tissue simulants (gels). We then present a mechanics-based model that calculates the deflection of a bevel-tipped needle inserted through a soft elastic medium. The model design is guided by microscopic observations of needle-gel interactions. The energy-based formulation incorporates tissue-specific parameters, and the geometry and material properties of the needle. Simulation results follow similar trends (deflection and radius of curvature) to those observed in experimental studies of robotic needle insertion.

Mapping the one-dimensional electronic States of nanotube peapod structures

Arrays of C60 molecules nested inside single-walled nanotubes represent a class of nanoscale materials having tunable properties. We report electronic measurements of this system made with a scanning tunneling microscope and demonstrate that the encapsulated C60 molecules modify the local electronic structure of the nanotube. Our measurements and calculations also show that a periodic array of C60 molecules gives rise to a hybrid electronic band, which derives its character from both the nanotube states and the C60 molecular orbitals.

Familial intrahepatic cholestasis 1: studies of localization and function

Mutations in the FIC1 gene constitute the molecular defect in familial intrahepatic cholestasis I (Fic1 [Byler's disease]) and benign recurrent intrahepatic cholestasis. This report describes the localization of Fic1 in rat liver and intestine, as well as biochemical and transfection studies that support its function as an energy-dependent aminophospholipid translocase. Immunocytochemistry of rat liver and immunoblotting of membrane fractions localized Fic1 to the canalicular, but not basolateral, plasma membrane domain. In the small intestine, Fic1 was localized to the apical membrane of epithelial cells. The distribution of Fic1 in liver plasma membrane fractions from control and taurocholate-treated rats correlated positively with adenosine triphosphate (ATP)-dependent aminophospholipid (phosphatidyl-serine) translocase activity. In canalicular membrane vesicles, translocase activity had an initial velocity of 3.3 nmol phosphatidylserine (PS) translocated per milligram of protein per minute and a K(m) (ATP) = 1.2 mmol/L; was inhibited by vanadate, N-ethylmaleimide, sodium azide, and calcium; and was unidirectional (i.e., from the outer to the inner canalicular plasma membrane leaflet). Transient transfection of CHOK1 cells with FIC1 cDNA resulted in appearance of FIC1 in membrane preparations and energy-dependent PS translocation in cells. These studies indicate that FIC1 is a canalicular P-type ATPase that participates in maintaining the distribution of aminophospholipids between the inner and outer leaflets of the plasma membrane. How this process produces cholestasis is under study.

The role of phosphoinositide 3-kinase in taurocholate-induced trafficking of ATP-dependent canalicular transporters in rat liver

Recent studies indicate that wortmannin, a potent inhibitor of phosphatidylinositol (PI) 3-kinase, interferes with bile acid secretion in rat liver; taurocholate induces recruitment of ATP-dependent transporters to the bile canalicular membrane, and PI 3-kinase products are important in intracellular trafficking. We investigated the role of PI 3-kinase in bile acid secretion by studying the in vivo effect of taurocholate, colchicine, and wortmannin on bile acid secretion, kinase activity, and protein levels in canalicular membrane vesicle (CMV) and sinusoidal membrane vesicle (SMV) fractions from rat liver. Treatment of rats or perfusion of isolated liver with taurocholate significantly increased PI 3-kinase activity in both membrane fractions. Taurocholate increased protein content of ATP-dependent transporters, which were detected only in CMVs, whereas increased levels of p85 and a cell adhesion molecule, cCAM 105, were observed in both fractions. Colchicine prevented taurocholate-induced changes in all proteins studied, as well as the increase in PI 3-kinase activity in CMVs, but it resulted in further accumulation of PI 3-kinase activity, p85, and cCAM 105 in SMVs. These results indicate that taurocholate-mediated changes involve a microtubular system. Wortmannin blocked taurocholate-induced bile acid secretion. The effect was more profound when wortmannin was administered prior to treatment with taurocholate. When wortmannin was given after taurocholate, the protein levels of each ATP-dependent transporter were maintained in CMVs, whereas the levels of p85 and cCAM decreased in both membrane fractions. Perfusion of liver with wortmannin before taurocholate administration blocked accumulation of all proteins studied in CMVs and SMVs. These results indicate that PI 3-kinase is required for intracellular trafficking of itself, as well as of ATP-dependent canalicular transporters.

The two pKa's of aspartate-85 and control of thermal isomerization and proton release in the arginine-82 to lysine mutant of bacteriorhodopsin

To explore the role of Arg82 in the catalysis of proton transfer in bacteriorhodopsin, we replaced Arg82 with Lys, which is also positively charged at neutral pH but has an intrinsic pKa of about 1.7 pH units lower than that of Arg. In the R82K mutant expressed in Halobacterium salinarium, we found the following: (1) The pKa of the purple-to-blue transition at low pH (which reflects the pKa of Asp85) is 3.6 +/- 0.1. At high pH a second inflection in the blue-to-purple transition with pKa = 8.0 is found. The complex titration behavior of Asp85 indicates that the pKa of Asp85 depends on the protonation state of another amino acid residue, X', which has a pKa = 8.0 in R82K. The fit of the experimental data to a model of two interacting residues shows that deprotonation of X' at high pH causes a shift in the pKa of Asp85 from 3.7 to 6.0. In turn, protonation of Asp85 decreases the pKa of X' by 2.3 pH units. This suggests that X' can release a proton upon formation of the M intermediate and the concomitant protonation of Asp85 in the photocycle. (2) The rate constant of dark adaptation, kda, is proportional to the fraction of blue membrane between pH 2 and 10, indicating that thermal isomerization proceeds through the transient protonation of Asp85. The pH dependence of kda shows that two groups with pKal = 3.9 and pKa2 = 8.0 control the rate of dark adaptation in R82K. The 1.7 pH unit shift in pKa2 in R82K compared to the wild type (WT) (pKa2 = 9.7) supports the hypothesis that X' is Arg82 in WT and Lys82 in R82K (or at least that these groups are the principal part of a cluster of residues that constitute X'). (3) Under steady state illumination, the efficiency of proton transport in R82K incorporated in phosphatidylcholine vesicles is at least 40% of that in the WT. A flash-induced transient signal of the pH-sensitive dye pyranine is similar to that in the WT (proton release precedes uptake), but the amplitude is small in R82K (about 15% of that found in the WT), indicating that only a small fraction of protons is released fast in R82K. This supports the suggestions that Arg82 is associated with the proton release pathway (acts as a proton release group or part of a proton release complex) and that Lys cannot efficiently substitute for Arg in this process.(ABSTRACT TRUNCATED AT 400 WORDS)

Arginine-82 regulates the pKa of the group responsible for the light-driven proton release in bacteriorhodopsin

In wild-type bacteriorhodopsin light-induced proton release occurs before uptake at neutral pH. In contrast, in mutants in which R82 is replaced by a neutral residue (as in R82A and R82Q), only a small fraction of the protons is released before proton uptake at neutral pH; the major fraction is released after uptake. In R82Q the relative amounts of the two types of proton release, "early" (preceding proton uptake) and "late" (following proton uptake), are pH dependent. The main conclusions are that 1) R82 is not the normal light-driven proton release group; early proton release can be observed in the R82Q mutant at higher pH values, suggesting that the proton release group has not been eliminated. 2) R82 affects the pKa of the proton release group both in the unphotolyzed state of the pigment and during the photocycle. In the wild type (in 150 mM salt) the pKa of this group decreases from approximately 9.5 in the unphotolyzed pigment to approximately 5.8 in the M intermediate, leading to early proton release at neutral pH. In the R82 mutants the respective values of pKa of the proton release group in the unphotolyzed pigment and in M are approximately 8 and 7.5 in R82Q (in 1 M salt) and approximately 8 and 6.5 in R82K (in 150 mM KCl). Thus in R82Q the pKa of the proton release group does not decrease enough in the photocycle to allow early proton release from this group at neutral pH. 3) Early proton release in R82Q can be detected as a photocurrent signal that is kinetically distinct from those photocurrents that are due to proton movements from the Schiff base to D85 during M formation and from D96 to the Schiff base during the M-->N transition. 4) In R82Q, at neutral pH, proton uptake from the medium occurs during the formation of O. The proton is released during the O-->bacteriorhodopsin transition, probably from D85 because the normal proton release group cannot deprotonate at this pH. 5) The time constant of early proton release is increased from 85 microseconds in the wild type to 1 ms in R82Q (in 150 mM salt). This can be directly attributed to the increase in the pKa of the proton release group and also explains the uncoupling of proton release from M formation. 6) In the E204Q mutant only late proton release is observed at both neutral and alkaline pH, consistent with the idea that E204 is the proton release group. The proton release is concurrent with the O-->bacteriorhodopsin transition, as in R82Q at neutral pH.

Phosphoinositide 3-kinase lipid products regulate ATP-dependent transport by sister of P-glycoprotein and multidrug resistance associated protein 2 in bile canalicular membrane vesicles

Bile acid transport and secretion in hepatocytes require phosphatidylinositol (PI) 3-kinase-dependent recruitment of ATP-dependent transporters to the bile canalicular membrane and are accompanied by increased canalicular PI 3-kinase activity. We report here that the lipid products of PI 3-kinase also regulate ATP-dependent transport of taurocholate and dinitrophenyl-glutathione directly in canalicular membranes. ATP-dependent transport of taurocholate and dinitrophenyl-glutathione in isolated canalicular vesicles from rat liver was reduced 50-70% by PI 3-kinase inhibitors, wortmannin, and LY294002, at concentrations that are specific for Type I PI 3-kinase. Inhibition was reversed by addition of lipid products of PI 3-kinase (PI 3,4-bisphosphate and, to a lesser extent, PI 3-phosphate and PI 3,4,5-trisphosphate) but not by PI 4, 5-bisphosphate. A membrane-permeant synthetic 10-mer peptide that binds polyphosphoinositides and leads to activation of PI 3-kinase in macrophages doubled PI 3-kinase activity in canalicular membrane vesicles and enhanced taurocholate and dinitrophenyl-glutathione transport in canalicular membrane vesicles above maximal ATP-dependent transport. The effect of the peptide was blocked by wortmannin and LY294002. PI 3-kinase activity was also necessary for function of the transporters in vivo. ATP-dependent transport of taurocholate and PI 3-kinase activity were reduced in canalicular membrane vesicles isolated from rat liver that had been perfused with taurocholate and wortmannin. PI 3,4-bisphosphate enhanced ATP-dependent transport of taurocholate in these vesicles above control levels. Our results indicate that PI 3-kinase lipid products are necessary in vivo and in vitro for maximal ATP-dependent transport of bile acid and nonbile acid organic anions across the canalicular membrane. Our results demonstrate regulation of membrane ATP binding cassette transporters by PI 3-kinase lipid products.

Selective inhibition of mitochondrial respiration and glycolysis in human leukaemic leucocytes by methylglyoxal

The effect of methylglyoxal on the oxygen consumption of mitochondria of both normal and leukaemic leucocytes was tested by using different respiratory substrates and complex specific artificial electron donors and inhibitors. The results indicate that methylglyoxal strongly inhibits mitochondrial respiration in leukaemic leucocytes, whereas, at a much higher concentration, methylglyoxal fails to inhibit mitochondrial respiration in normal leucocytes. Methylglyoxal strongly inhibits ADP-stimulated alpha-oxoglutarate and malate plus NAD+-dependent respiration, whereas, at a higher concentration, methylglyoxal fails to inhibit succinate and alpha-glycerophosphate-dependent respiration. Methylglyoxal also fails to inhibit respiration which is initiated by duroquinone and cannot inhibit oxygen consumption when the N,N,N', N'-tetramethyl-p-phenylenediamine by-pass is used. NADH oxidation by sub-mitochondrial particles of leukaemic leucocytes is also inhibited by methylglyoxal. Lactaldehyde, a catabolite of methylglyoxal, can exert a protective effect on the inhibition of leukaemic leucocyte mitochondrial respiration by methylglyoxal. Methylglyoxal also inhibits l-lactic acid formation by intact leukaemic leucocytes and critically reduces the ATP level of these cells, whereas methylglyoxal has no effect on normal leucocytes. We conclude that methylglyoxal inhibits glycolysis and the electron flow through mitochondrial complex I of leukaemic leucocytes. This is strikingly similar to our previous studies on mitochondrial respiration, glycolysis and ATP levels in Ehrlich ascites carcinoma cells [Ray, Dutta, Halder and Ray (1994) Biochem. J. 303, 69-72; Halder, Ray and Ray (1993) Int. J. Cancer 54, 443-449], which strongly suggests that the inhibition of electron flow through complex I of the mitochondrial respiratory chain and inhibition of glycolysis by methylglyoxal may be common characteristics of all malignant cells.

Recognizing phosphatidylinositol 3-phosphate

Phosphatidylinositol 3-phosphate directs the endosomal localization of regulatory proteins by binding to FYVE and PX domains. New structures of these domains complexed with the phosphoinositide headgroup show how interactions with phosphate and hydroxyl groups differentiate this lipid from all others.

A new family of lipolytic plant enzymes with members in rice, arabidopsis and maize

We have noted a striking similarity between the sequences of proteins in a novel family of lipases we recently reported [Upton, C. and Buckley, J. T. (1995) Trends Biol. Sci. 20, 178-9] and more than 120 sequences from the database of Expressed Sequence Tags (dbEST) which correspond to at least 30 unique genes from arabidopsis, rice and maize. A cDNA (Arab-1) corresponding to one of these sequences was isolated, sequenced and translated. There was significant similarity to sequences in the new lipase family over the entire open reading frame of Arab-1 and when expressed in E. coli, the gene product was lipolytic. Arab-1 and genes for some of the other plant proteins appear to be differentially expressed. They may play a role in the regulation of lipid metabolism during plant development.

Assessment of autonomic dysfunction in Guillain-Barré syndrome and its prognostic implications

Twenty-four patients with Guillain-Barré syndrome were prospectively evaluated for evidence of autonomic dysfunction. It occurred in 16 (66.7%) patients, usually during the peak period of paralysis, in the form of either excess or inadequate activity of sympathetic and/or parasympathetic nervous systems. Its clinical manifestations comprised of sinus tachycardia (33.3%), bradycardia (8.3%), hypertension (33.3%), postural hypotension (35%), urinary sphincteric disturbances (20.8%) and anhydrosis of lower limbs (12.5%). Assessment of cardiovascular responses to autonomic function tests revealed impaired alterations in heart rate during deep breathing (31.6%), Valsalva's manoeuvre (28.6%), sustained handgrip (25%), cold-pressor test (36.4%), postural change (35%) and atropine test (20%); and impaired rise in blood pressure during firm handgrip (25%) and cold-pressor test (36.6%). ECG abnormalities were noticed in 8 (33.3%) patients. They comprised of depressed ST segment in 5, inverted T wave in 3, tall T wave in 2 and prolonged QTc in 2 patients. Two patients died of respiratory failure. Autonomic dysfunction in Guillain-Barré syndrome did not appear to have any prognostic significance as there was no significant difference in autonomic dysfunction between good - and bad - outcome groups of patients.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2012-2017: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2012 to December 2017 in 523 intensive care units (ICUs) in 45 countries from Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, prospective data from 532,483 ICU patients hospitalized in 242 hospitals, for an aggregate of 2,197,304 patient days, were collected through the INICC Surveillance Online System (ISOS). The Centers for Disease Control and Prevention-National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI) were applied.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the medical-surgical ICUs, the pooled central line-associated bloodstream infection rate was higher (5.05 vs 0.8 per 1,000 central line-days); the ventilator-associated pneumonia rate was also higher (14.1 vs 0.9 per 1,000 ventilator-days,), as well as the rate of catheter-associated urinary tract infection (5.1 vs 1.7 per 1,000 catheter-days). From blood cultures samples, frequencies of resistance, such as of Pseudomonas aeruginosa to piperacillin-tazobactam (33.0% vs 18.3%), were also higher.

CONCLUSIONS

Despite a significant trend toward the reduction in INICC ICUs, DA-HAI rates are still much higher compared with CDC-NHSN's ICUs representing the developed world. It is INICC's main goal to provide basic and cost-effective resources, through the INICC Surveillance Online System to tackle the burden of DA-HAIs effectively.