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Publication
Journal: Investigative Ophthalmology and Visual Science
April/11/1991
Abstract
A new technique has been developed to determine the axial length of the human eye in vivo. Based on laser interferometry in conjunction with the Doppler technique, it uses partially coherent light. This new technique complies with laser safety regulations. High accuracy is achieved, the optical length (OL) can be determined within +/- 30 microns, and the reproducibility of the geometric eye length is greater than +/- 25 microns. Possible errors are discussed. First comparisons with the ultrasound technique yield good agreement for emmetropic subjects and for subjects with a myopia of up to 10 diopters. The advantages of the laser doppler interferometry (LDI) technique are high accuracy, high transversal resolution, and more comfort for the patient (it is a noncontact method; no anesthesia is needed). Possible future applications of LDI, like measurements of fundus profiles and of retinal thickness, are mentioned.
Publication
Journal: Molecules
January/14/2009
Abstract
Proanthocyanidins (PAs), also known as condensed tannins, are a group of polyphenolic secondary metabolites synthesized in plants as oligomers or polymers of flavan-3-ol units via the flavonoid pathway. Due to their structural complexity and varied composition, only in the recent years has the study on the biosynthesis and regulation of PAs in plants taken off, although some details of the synthetic mechanism remain unclear. This paper aims to summarize the status of research on the structures of PAs in plants, the genes encoding key enzymes of biosynthetic pathway, the transport factors, the transcriptional regulation of PA biosynthesis and the genetic manipulation of PAs. The problems of this field were also discussed, including the nature of the final "enzyme" which catalyzes the polymerization reaction of PAs and the possible mechanism of how the elementary units of flavanols are assembled in vivo.
Publication
Journal: Blood
October/24/2012
Abstract
Mutations in the nucleophosmin gene (NPM1(mut)) are one of the most frequent molecular alterations in acute myeloid leukemia (AML), and immune responses may contribute to the favorable prognosis of AML patients with NPM1(mut). In the present study, we were able to demonstrate both CD4(+) and CD8(+) T-cell responses against NPM1(mut). Ten peptides derived from wild-type NPM1 and NPM1(mut) were subjected to ELISPOT analysis in 33 healthy volunteers and 27 AML patients. Tetramer assays against the most interesting epitopes were performed and Cr(51)-release assays were used to show the cytotoxicity of peptide-specific T cells. Moreover, HLA-DR-binding epitopes were used to test the role of CD4(+) T cells in NPM1 immunogenicity. Two epitopes (epitopes #1 and #3) derived from NPM1(mut) induced CD8(+) T-cell responses. A total of 33% of the NPM1(mut) AML patients showed immune responses against epitope #1 and 44% against epitope #3. Specific lysis of leukemic blasts was detected. To obtain robust immune responses against tumor cells, the activation of CD4(+) T cells is crucial. Therefore, overlapping (<em>OL</em>) peptides were analyzed in ELISPOT assays and <em>OL</em>8 was able to activate both CD8(+) and CD4(+) T cells. The results of the present study show that NPM1(mut) induces specific T-cell responses of CD4(+) and CD8(+) T cells and therefore is a promising target for specific immunotherapies in AML.
Publication
Journal: Nutrition and Cancer
November/9/2008
Abstract
Evidence from laboratory-based in vitro studies provides compelling evidence supporting the involvement of dietary flavonoid intake in human cancer risk. Associations between intakes of individual flavonoids and disease outcomes at the population level are emerging from recent epidemiological studies. As an important step in the development of methods to assess flavonoid intakes across populations, the major sources of dietary flavonoids in the adult Australian population were identified. Data from a 24-h diet recall questionnaire used in a national nutrition survey (NNS95-comprising a sample of 10,851 subjects aged 19 yr and over) were combined with U.S. Department of Agriculture data on flavonoid content of foods to identify key sources. Black and green teas clearly were the dominant sources of the flavonols kaempferol, myricetin, and quercetin. Other significant flavonol sources included onion (isorhamnetin and quercetin), broccoli (kaempferol and quercetin), apple (quercetin), grape (quercetin), coffee (myrcetin), and beans (quercetin). Black and green teas also were dominant sources of flavon-3-ols, with wine, apples, and pears contributing somewhat. In terms of flavanone consumption, oranges (hesperetin and naringenin), lemon (eriodictyol), mandarin (hesperetin), and grapefruit (naringenin) were the major sources. Parsley (apigenin), celery (apigenin and luteolin), and English spinach (luteolin) were the major flavone sources. Wine was the major anthocyanadin source (delphinidin, malvidin, peonidin and petunidin), with smaller amounts from cherry (peonidin) and blueberry (delphinidin, malvidin, peonidin and petunidin). It is suggested that the relatively small number of aforementioned key foods form the basis of food frequency questionnaires to assess flavonoid intake.
Publication
Journal: Hormones and Behavior
April/24/2000
Abstract
We tested the hypothesis that isolated steroids, claimed to act like pheromones, affect human psychological state or mood. In the first experiment, we established that two steroids, Delta4, 16-androstadien-3-one and 1,3,5(10)16-estratetraen-3-ol, modulated emotional states within 6 min of exposure. In men and women, neither steroid had specific effects on states of alertness or negative-confused mood. However, both steroids increased positive stimulated mood state in women but decreased it in men. These psychological findings do not parallel the reported sexually specific effects of these two steroids on the surface potential activity of putative vomeronasal epithelium. In a second experiment on women, we replicated that Delta4,16-androstadien-3-one modulated their general mood state, even when women were not aware of its odor and gave identical olfactory descriptions for the steroid and the control carrier solutions. In this within-subjects, repeated-measures experiment, androstadienone prevented the deterioration in general mood which occurred during exposure to the clove oil carrier solution in the laboratory environment. Thus, androstadienone appears to modulate affect, rather than releasing stereotyped behaviors or emotions. It is premature to call these steroids human pheromones. They are nonetheless psychologically potent, mandating future work delineating their function-i.e., whether these steroids are communicative chemosignals, context specific, or related to unconscious associations. In light of these modulatory effects and the complexity of human behavior, the function of chemosignals and pheromonal systems in a variety of species may need to be expanded to include the concept of modulators, as well as the traditional releasers, primers, and signaling compounds.
Publication
Journal: PLoS ONE
September/23/2008
Abstract
BACKGROUND
Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies.
RESULTS
Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP) in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z)-9-tetradecenol (Z9-14:OH), hexadecanal (16:Ald ) and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol), and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP.
CONCLUSIONS
This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant to future research. Such a comparison will in turn contribute to understanding the evolution of sex pheromone production and reception in butterflies.
Publication
Journal: Phytochemistry
December/13/2001
Abstract
The function and properties of heterologously expressed full-length cDNA clones, isolated from a Taxus cDNA library and specific to Taxol biosynthesis, are summarized. Recombinant enzymes are described that catalyze early steps of the pathway, including taxadiene synthase, taxadien-5alpha-ol-O-acetyltransferase and taxadien-5alpha-yl acetate 10beta-hydroxylase, and that catalyze late steps, including 10-deacetylbaccatin III-10beta-O-acetyltransferase and taxane 2alpha-O-benzoyltransferase. The properties of Taxus geranylgeranyl diphosphate synthase are also described; although this synthase does not mediate a committed step of Taxol biosynthesis, it does provide the universal plastidial diterpenoid precursor, geranylgeranyl diphosphate, for initiating Taxol biosynthesis.
Publication
Journal: British Journal of Pharmacology
January/27/1998
Abstract
1. The effects of five structurally dissimilar general anaesthetics were examined in voltage-clamp recordings of agonist-evoked currents mediated by recombinant gamma-aminobutyric acid (GABA)A receptors composed of human alpha 1 beta 1 and gamma 2L subunits expressed in Xenopus laevis oocytes. A quantitative comparison of the effects of these agents was made upon recombinant glycine receptors expressed as a homo-oligomer of human alpha 1 subunits, or as a hetero-oligomer of human alpha 1 and rat beta subunits. 2. Complementary RNA-injected oocytes expressing GABAA receptors responded to bath applied GABA with an EC50 of 158 +/- 34 microM. Oocytes expressing alpha 1 and alpha 1 beta glycine receptors subsequent to cDNA injection displayed EC50 values of 76 +/- 2 microM and 66 +/- 2 microM, respectively, in response to bath applied glycine. 3. Picrotoxin antagonized responses mediated by homo-oligomeric alpha 1 glycine receptors with an IC50 of 4.2 +/- 0.8 microM. Hetero-oligomeric alpha 1 beta glycine receptors were at least 100-fold less sensitive to blockade by picrotoxin. 4. With the appropriate agonist EC10, propofol enhanced GABA and glycine-evoked currents to approximately the maximal response produced by a saturating concentration of either agonist (i.e. Imax). The calculated EC50 values were 2.3 +/- 0.2 microM, 16 +/- 3 microM and 27 +/- 2 microM, for GABAA alpha 1 beta 1 gamma 2L, glycine alpha 1 and alpha 1 beta receptors, respectively. At relatively high concentrations, propofol was observed to activate directly both GABAA and glycine receptors. 5. Pentobarbitone potentiated GABA-evoked currents to 117 +/- 8.5% of Imax with an EC50 of 65 +/- 3 microM. The barbiturate also produced a substantial enhancement of the glycine-evoked currents, Imax and EC50 values being 71 +/- 2% and 845 +/- 66 microM and 51 +/- 10% and 757 +/- 30 microM for homomeric alpha 1 and heteromeric alpha 1 beta glycine receptors respectively. At high concentrations, pentobarbitone directly activated GABAA, but not glycine, receptors. 6. The potentiation by propofol or pentobarbitone of currents mediated by alpha 1 homo-oligomeric glycine receptors was in both cases associated with a parallel sinistral shift of the glycine concentration-effect curve. The effects of binary combinations of pentobarbitone and propofol at maximally effective concentrations were mutually occlusive suggesting a common site, or mechanism, of action. 7. GABA-evoked currents were maximally potentiated by etomidate to 79 +/- 2% of Imax (EC50 of 8.1 +/- 0.9 microM). By contrast, glycine-induced currents mediated by alpha 1 and alpha 1 beta glycine receptor isoforms were enhanced only to 29 +/- 4% and 28 +/- 3% of Imax. Limited solubility precluded the calculation of EC50 values for the effect of etomidate at glycine receptors. None of the receptor isoforms examined were directly activated by etomidate. 8. The neurosteroid 5 alpha-pregnan-3 alpha-ol-20-one potentiated GABA-evoked currents to 69 +/- 4% of Imax, with an EC50 value of 89 +/- 6 nM. In contrast, both alpha 1 homo-oligomeric and alpha 1 beta hetero-oligomeric glycine receptors were insensitive to the action of this steroid. A direct agonist action of the steroid was discernible at GABAA, but not glycine, receptors. 9. Trichloroethanol, the active metabolite of the general anaesthetic chloral hydrate, enhanced glycine-evoked currents to 77 +/- 10% and 94 +/- 4% of Imax on alpha 1 and alpha 1 beta glycine receptors, with EC50 values of 3.5 +/- 0.1 mM and 5.9 +/- 0.3 mM respectively. On GABAA receptors, trichloroethanol had a lower maximum enhancement (52 +/- 5% of Imax), but a slightly higher potency (EC50 1.0 +/- 0.1 mM). Trichloroethanol activated neither GABAA, nor glycine, receptors. 10. The data demonstrate a variety of intravenous general anaesthetic agents, at clinically relevant concentrations, to augment preferentially GABA-evoked currents mediated by the alpha1beta1upsilon2L receptor subunit combination as compared to their effects on both alpha1 and alpha1beta glycine receptors. However, the presence on glycine receptors of lower affinity modulatory binding sites for pentobarbitone, propofol and trichloroethanol may aid in the identification of the molecular determinants of the CNS actions of these anaesthetics.
Publication
Journal: Journal of Steroid Biochemistry and Molecular Biology
October/9/1995
Abstract
The metabolic fate of the dietary isoflavones daidzein and genistein was investigated in human volunteers challenged with soya. Urinary diphenols, isolated by partition chromatography on Sephadex LH-20, were characterized and identified by profile capillary gas chromatography (GC) and electron ionization mass spectrometry (GC-EIMS) analysis of the trimethylsilyl ether (TMS) derivatives. Novel isoflavonic phytoestrogens found in the urine of volunteers were those of tetrahydrodaidzein, dihydrogenistein, 6'-hydroxy-O-demethylangolesin and 2-dehydro-O-demethylangolensin. Other known diphenols identified were those of equal, dehydrodaidzein, O-demethylangolensin, daidzein, genistein, glycitein, and the lignan enterolactone. Two other urinary isomers with a fragmentation pattern closely resembling that of the persilylated TMS ethers of cis/trans-isomers of tetrahydrodaidzein, were characterized based on the elucidation of fragments associated with the loss of a non-phenolic-OTMS functional group in ring-C. These are fragments presented in the persilylated mass spectra of isoflavan-4-ols and isoflav-3-ene-4-ols, demonstrated here by a combination of simple and tandem mass spectrometry study of the deuterated persilylated TMS ethers of dihydrodaidzein. In a similar study we also present the data on the structural identification and fragment elucidation of the keto/enol tautomers of the TMS ether derivatives of the dihydro derivatives of daidzein and genistein, observed in the urine of volunteers and considered probable products of the derivatization process. Finally, the GC and GC-MS data of two unknown isoflavonoids and that of a lignan-like compound are presented together with those of dihydrodaidzein, dihydrogenistein, tetrahydrodaidzein and 2-dehydro-O-demethylangolensin. The latter four were obtained here as products of small scale chemical synthesis in a preliminary study on the tentative identification of urinary isoflavonoids in human volunteers challenged with soya.
Publication
Journal: Molecular Pharmacology
December/3/2006
Abstract
Previous studies on the drug content of pelleted tubulin polymers suggest that peloruside A binds in the laulimalide site, which is distinct from the taxoid site. In a tubulin assembly system containing microtubule-associated proteins and GTP, however, peloruside A was significantly less active than laulimalide, inducing assembly in a manner that was most similar to sarcodictyins A and B. Because peloruside A thus far seems to be the only compound that mimics the action of laulimalide, we examined combinations of microtubule-stabilizing agents for synergistic effects on tubulin assembly. We found that peloruside A and laulimalide showed no synergism but that both compounds could act synergistically with a number of taxoid site agents [paclitaxel, epothilones A/B, discodermolide, dictyostatin, eleutherobin, the steroid derivative 17beta-acetoxy-2-ethoxy-6-oxo-B-homo-estra-1,3,5(10)-trien-3-ol, and cyclostreptin]. None of the taxoid site compounds showed any synergism with each other. From an initial study with peloruside A and cyclostreptin, we conclude that the synergism phenomenon derives, at least in part, from an apparent lowering of the tubulin critical concentration with drug combinations compared with single drugs. The apparent binding of peloruside A in the laulimalide site led us to attempt construction of a pharmacophore model based on superposition of an energy-minimized structure of peloruside A on the crystal structure of laulimalide. Although the different sizes of the macrocycles limited our ability to superimpose the two molecules, atom correspondences that were observed were consistent with the difficulty so far experienced in creation of fully active analogs of laulimalide.
Publication
Journal: Journal of Biological Chemistry
August/13/1997
Abstract
Stimulation of cells with certain agonists often activates both phospholipases C and D. These generate diacylglycerol and phosphatidate, respectively, although the two lipids are also apparently interconvertable through the actions of phosphatidate phosphohydrolase and diacylglycerol kinase. Diacylglycerol activates protein kinase C while one role for phosphatidate is the activation of actin stress fiber formation. Therefore, if the two lipids are interconvertable, it is theoretically possible that an uncontrolled signaling loop could arise. To address this issue structural analysis of diacylglycerol, phosphatidate, and phosphatidylbutanol (formed in the presence of butan-1-ol) from both Swiss 3T3 and porcine aortic endothelial cells was performed. This demonstrated that phospholipase C activation generates primarily polyunsaturated species while phospholipase D activation generates saturated/monounsaturated species. In the endothelial cells, where phospholipase D was activated by lysophosphatidic acid independently of phospholipase C, there was no activation of protein kinase C. Thus we propose that only polyunsaturated diacylglycerols and saturated/monounsaturated phosphatidates function as intracellular messengers and that their interconversion products are inactive.
Publication
Journal: Molecular Pharmacology
February/26/1997
Abstract
G protein activation by different mu-selective opioid agonists was examined in rat thalamus, SK-N-SH cells, and mu-opioid receptor-transfected mMOR-CHO cells using agonist-stimulated guanosine-5'-O-(gamma-thio)-triphosphate ([35S]GTP gamma S) binding to membranes in the presence of excess GDP. [D-Ala2, N-MePhe4, Gly5-ol]Enkephalin (DAMGO) was the most efficacious agonist in rat thalamus and SK-N-SH cells, followed by (in rank order) fentanyl = morphine>>>> buprenorphine. In mMOR-CHO cells expressing a high density of mu receptors, no differences were observed among DAMGO, morphine or fentanyl, but these agonists were more efficacious than buprenorphine, which was more efficacious than levallorphan. In all three systems, efficacy differences were magnified by increasing GDP concentrations, indicating that the activity state of G proteins can affect agonist efficacy. Scatchard analysis of net agon stimulated [35S]GTP gamma S binding revealed two major components responsible for agonist efficacy differences. First, differences in the KD values of agonist-stimulated [35S]GTP gamma S binding between high efficacy agonists (DAMGO, fentanyl, and morphine) and classic partial agonists (buprenorphine and levallorphan) were observed in all three systems. Second, differences in the Bmax value of agonist-stimulated [35S]GTP gamma S binding were observed between DAMGO and morphine or fentanyl in rat thalamus and SK-N-SH cells and between the high efficacy agonists and buprenorphine or levallorphan in all three systems. These results suggest that mu-opioid agonist efficacy is determined by the magnitude of the receptor-mediated affinity shift in the binding of GTP (or[35S]GTP gamma S) versus GDP to the G protein and by the number of G proteins activated per occupied receptor.
Publication
Journal: Applied and Environmental Microbiology
July/4/2001
Abstract
Strains of Xylella fastidiosa isolated from grape, almond, maple, and oleander were characterized by enterobacterial repetitive intergenic consensus sequence-, repetitive extragenic palindromic element (REP)-, and random amplified polymorphic DNA (RAPD)-PCR; contour-clamped homogeneous electric field (CHEF) gel electrophoresis; plasmid content; and sequencing of the 16S-23S rRNA spacer region. Combining methods gave greater resolution of strain groupings than any single method. Strains isolated from grape with Pierce's disease (PD) from California, Florida, and Georgia showed greater than previously reported genetic variability, including plasmid contents, but formed a cluster based on analysis of RAPD-PCR products, NotI and SpeI genomic DNA fingerprints, and 16S-23S rRNA spacer region sequence. Two groupings of almond leaf scorch (ALS) strains were distinguished by RAPD-PCR and CHEF gel electrophoresis, but some ALS isolates were clustered within the PD group. RAPD-PCR, CHEF gel electrophoresis, and 16S-23S rRNA sequence analysis produced the same groupings of strains, with RAPD-PCR resolving the greatest genetic differences. Oleander strains, phony peach disease (PP), and oak leaf scorch (OLS) strains were distinct from other strains. DNA profiles constructed by REP-PCR analysis were the same or very similar among all grape strains and most almond strains but different among some almond strains and all other strains tested. Eight of 12 ALS strains and 4 of 14 PD strains of X. fastidiosa isolated in California contained plasmids. All oleander strains carried the same-sized plasmid; all OLS strains carried the same-sized plasmid. A plum leaf scald strain contained three plasmids, two of which were the same sizes as those found in PP strains. These findings support a division of X. fastidiosa at the subspecies or pathovar level.
Publication
Journal: Nucleic Acids Research
August/15/1985
Abstract
Oligonucleotides containing a free sulphydryl group at their 5'-termini have been synthesised and further derivatised with thiol specific probes. The nucleotide sequence required is prepared using standard solid phase phosphoramidite techniques and an extra round of synthesis is then performed using the S-triphenylmethyl O-methoxymorpholinophosphite derivatives of 2-mercaptoethanol, 3-mercaptopropan (1) ol or 6-mercaptohexan (1) ol. After cleavage from the resin and removal of the phosphate and base protecting groups, this yields an oligonucleotide containing an S-triphenylmethyl group attached to the 5'-phosphate group via a two, three or six carbon chain. The triphenylmethyl group can be readily removed with silver nitrate to give the free thiol. With the three and six carbon chain oligonucleotides, this thiol can be used, at pH 8, for the attachment of thiol specific probes as illustrated by the reaction with fluorescent conjugates of iodoacetates and maleiimides. However, oligonucleotides containing a thiol attached to the 5'-phosphate group via a two carbon chain are unstable at pH 8 decomposing to the free 5'-phosphate and so are unsuitable for further derivatisation.
Publication
Journal: Journal of Agricultural and Food Chemistry
March/1/2009
Abstract
Procyanidins (PCs) are highly abundant phenolic compounds in the human diet and might be responsible for the health effects of chocolate and wine. Due to low absorption of intact PCs, microbial metabolism might play an important role. So far, only a few studies, with crude extracts rich in PCs but also containing a multitude of other phenolic compounds, have been performed to reveal human microbial PC metabolites. Therefore, the origin of the metabolites remains questionable. This study included in vitro fermentation of purified PC dimers with human microbiota. The main metabolites identified were 2-(3,4-dihydroxyphenyl)acetic acid and 5-(3,4-dihydroxyphenyl)-gamma-valerolactone. Other metabolites detected were 3-hydroxyphenylacetic acid, 4-hydroxyphenylacetic acid, 3-hydroxyphenylpropionic acid, phenylvaleric acids, monohydroxylated phenylvalerolactone, and 1-(3',4'-dihydroxyphenyl)-3-(2'',4'',6''-trihydroxyphenyl)propan-2-ol. Metabolites that could be quantified accounted for at least 12 mol % of the dimers, assuming 1 mol of dimers is converted into 2 mol of metabolite. A degradation pathway, partly different from that of monomeric flavan-3-ols, is proposed.
Publication
Journal: Investigative Ophthalmology and Visual Science
September/29/2011
Abstract
OBJECTIVE
To present and evaluate a new methodology for combining longitudinal information from structural and functional tests to improve detection of glaucoma progression and estimation of rates of change.
METHODS
This observational cohort study included 434 eyes of 257 participants observed for an average of 4.2 ± 1.1 years and recruited from the Diagnostic Innovations in Glaucoma Study (DIGS). The subjects were examined annually with standard automated perimetry, optic disc stereophotographs, and scanning laser polarimetry with enhanced corneal compensation. Rates of change over time were measured using the visual field index (VFI) and average retinal nerve fiber layer thickness (TSNIT average). A bayesian hierarchical model was built to integrate information from the longitudinal measures and classify individual eyes as progressing or not. Estimates of sensitivity and specificity of the bayesian method were compared with those obtained by the conventional approach of ordinary least-squares (OLS) regression.
RESULTS
The bayesian method identified a significantly higher proportion of the 405 glaucomatous and suspect eyes as having progressed when compared with the OLS method (22.7% vs. 12.8%; P < 0.001), while having the same specificity of 100% in 29 healthy eyes. In addition, the bayesian method identified a significantly higher proportion of eyes with progression by optic disc stereophotographs compared with the OLS method (74% vs. 37%; P = 0.001).
CONCLUSIONS
A bayesian hierarchical modeling approach for combining functional and structural tests performed significantly better than the OLS method for detection of glaucoma progression. (ClinicalTrials.gov number, NCT00221897.).
Publication
Journal: Health Services Research
March/13/2008
Abstract
OBJECTIVE
To compare different approaches to address ceiling effects when predicting EQ-5D index scores from the 10 subscales of the MOS-HIV Health Survey.
METHODS
Data were collected from an HIV treatment trial. Statistical methods included ordinary least squares (OLS) regression, the censored least absolute deviations (CLAD) approach, a standard two-part model (TPM), a TPM with a log-transformed EQ-5D index, and a latent class model (LCM). Predictive accuracy was evaluated using percentage of absolute error (R(1)) and squared error (R(2)) predicted by statistical methods.
RESULTS
A TPM with a log-transformed EQ-5D index performed best on R(1); a LCM performed best on R(2). In contrast, the CLAD was worst. Performance of the OLS and a standard TPM were intermediate. Values for R(1) ranged from 0.33 (CLAD) to 0.42 (TPM-L); R(2) ranged from 0.37 (CLAD) to 0.53 (LCM).
CONCLUSIONS
The LCM and TPM with a log-transformed dependent variable are superior to other approaches in handling data with ceiling effects.
Publication
Journal: Nephrology Dialysis Transplantation
June/2/2010
Abstract
BACKGROUND
In children, growth can be used as a measurable parameter of adequate nutrition and dialysis dose. Despite daily administration of recombinant human growth hormone (rhGH), growth retardation remains a frequent problem in children on chronic dialysis. Therefore, we performed an observational prospective non-randomized study of children on in-centre daily on line haemodiafiltration (D-OL-HDF) dialysis with the aim of promoting growth.
METHODS
Mean age at the start of the study was 8 years and 3 months, and all children had been receiving rhGH treatment for >12 months before enrolment. Mean follow-up time on D-OL-HDF was 20.5 +/- 8 months (range, 11-39 months). Renal residual function was either <3 mL/min/1.73 m(2) or anuric. Vascular access was a fistula (13/15) or a central venous catheter (2/15). Dialysis was delivered daily, six days a week in 3 hourly sessions (18 h/week), in a predilution OL-HDF mode, allowing a high convective volume (18 to 27 L/m(2) body surface area per session), Kt/V(urea) on line measured at least 1.4 per session.
RESULTS
Mean growth velocity increased from 3.8 +/- 1.1 cm/year at inclusion to 14.3 +/- 3.8 cm/year during the first year of D-OL-HDF, resulting in a change in height standard deviation score (SDS) over the follow-up period from -1.5 +/- 0.3 SDS to +0.2 +/- 1.1 SDS. Increase in body mass was also noted without impaired control of blood pressure. Time-average deviation for urea (TAD(urea)) was low at 2.5 +/- 0.4 as was TAD(bicarbonate) due to the normal pre and post dialysis bicarbonate levels, respectively, 23.6 +/- 0.5 mmol/L and 26.6 +/- 0.5 mmol/L. The absence of any dietary restrictions permitted a mean protein diet intake (PDI) of 2.5 +/- 0.2 g/kg/day (PDI measured from a 3-day diet survey), contrasting with a mean normalized protein nitrogen appearance (nPNA) of 1.53 +/- 0.12 g/kg/day (nPNA calculated from urea dialytic kinetic). A low C-reactive protein was noted in 13/15 children, and mean beta(2) microglobulin was low, 15.3 +/- 0.3.3 mg/L.
CONCLUSIONS
Daily OL-HDF promotes catch-up growth in children despite on chronic dialysis. This catch-up growth if continued, should allow the children to reach their mid-parental target height in the future. It could be speculated that the improved response to rhGH is the result of several combined factors conducting to less malnutrition and to less cachexia.
Publication
Journal: European Journal of Pharmacology
October/11/2000
Abstract
We have investigated the inhibition of lipopolysaccharide stimulated nitric oxide production in RAW264.7 macrophages by the cannabinoids and the putative cannabinoid CB(2)-like receptor ligand, palmitoylethanolamide. (R)-(+)-[2, 3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo-[1,2,3-de]-1, 4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate ((+)-WIN55212) and, to a lesser extent (-)-cis-3-[2-hydroxy-4-(1, 1-dimethylheptyl)phenyl]-trans-4-(3-hydroxy-propyl)cyclohexan++ +-1-ol (CP55940), significantly inhibited lipopolysaccharide stimulated nitric oxide production. The level of inhibition was found to be dependent on the concentration of lipopolysaccharide used to induce nitric oxide production. Palmitoylethanolamide significantly inhibited nitric oxide production induced by lipopolysaccharide. The inhibition of nitric oxide production by (+)-WIN55212 but not palmitoylethanolamide was significantly attenuated in the presence of the cannabinoid CB(2) receptor antagonist, N-[(1S)-endo-1,3, 3-trimethyl bicyclo [2.2.1] heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazo le- 3-carboxamide (SR144528). (+)-WIN55212 produced a pertussis toxin-sensitive parallel rightward shift in the log concentration-response curve for lipopolysaccharide, causing a fivefold increase in the EC(50) value for lipopolysaccharide with no change in the E(max) value. (-)-WIN55212 had no effect on the log concentration-response curve for lipopolysaccharide. Palmitoylethanolamide did not produce a rightward shift in the lipopolysaccharide concentration-response curve. However, it did produce a pertussis toxin-insensitive reduction in the E(max) value. The results suggest that the inhibition of lipopolysaccharide mediated nitric oxide release by (+)-WIN55212 in murine macrophages is mediated by cannabinoid CB(2) receptors. In contrast, the inhibition by palmitoylethanolamide does not appear to be mediated by cannabinoid receptors.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
August/16/2004
Abstract
The straight-chain C(10) to C(18) unsaturated aliphatic compounds containing an oxygenated functional group (aldehyde, alcohol, or acetate ester) derived from saturated C(16) or C(18) fatty acids are a major class of sex pheromone components produced by female moths. In the biosynthesis of these pheromone components, various combinations of limited chain-shortening and regio- and stereospecific desaturation reactions significantly contribute to the production of a vast number of the species-specific pheromone components in Lepidoptera. Biosynthesis of the silkmoth sex pheromone bombykol, (E,Z)-10,12-hexadecadien-1-ol, involves two consecutive desaturation steps, the second of which is unique in that it generates a conjugated diene system from the Delta11-monoene C(16) intermediate. In experiments designed to characterize the acyl-CoA desaturases responsible for bombykol biosynthesis, we have cloned three cDNAs encoding desaturase family members from the pheromone gland of the inbred strain of the silkmoth, Bombyx mori. Transcript analyses by RT-PCR and subsequent functional assays using a Bac-to-Bac baculovirus expression system revealed that desat1 is the only desaturase gene prominently expressed during pheromonogenesis and that its gene product, B. mori Desat1, possesses both Z11 desaturation and Delta10,12-desaturation activities. Consequently, we have concluded that B. mori Desat1 is not only a bifunctional desaturase involved in bombykol biosynthesis but that it is also the enzyme responsible for both desaturation steps.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
July/4/2006
Abstract
The progesterone derivative 4,16-androstadien-3-one (AND) and the estrogen-like steroid estra-1,3,5(10),16-tetraen-3-ol (EST) are candidate compounds for human pheromones. In previous positron emission tomography studies, we found that smelling AND and EST activated regions primarily incorporating the sexually dimorphic nuclei of the anterior hypothalamus, that this activation was differentiated with respect to sex and compound, and that homosexual men processed AND congruently with heterosexual women rather than heterosexual men. These observations indicate involvement of the anterior hypothalamus in physiological processes related to sexual orientation in humans. We expand the information on this issue in the present study by performing identical positron emission tomography experiments on 12 lesbian women. In contrast to heterosexual women, lesbian women processed AND stimuli by the olfactory networks and not the anterior hypothalamus. Furthermore, when smelling EST, they partly shared activation of the anterior hypothalamus with heterosexual men. These data support our previous results about differentiated processing of pheromone-like stimuli in humans and further strengthen the notion of a coupling between hypothalamic neuronal circuits and sexual preferences.
Publication
Journal: Synapse
January/11/2004
Abstract
A series of mu opioid receptor gene Oprm splice variants have been reported that differ only at their C-terminus. These variants all contain exons 1, 2, and 3 of the gene, the exons responsible for coding all seven transmembrane domains. Whereas MOR-1 also has exon 4 that encodes for an additional 12 amino acids at the tip of the C-terminus, the other MOR-1 variants have unique amino acid sequences distinct from those in MOR-1 due to alternative splicing. All these variants are mu-selective in binding assays. The current study explored the ability of these variants to stimulate [35S]GTPgammaS binding to assess them functionally. Only mu opioids stimulated [35S]GTPgammaS binding. Among the mu opioids we noted marked differences in their maximal stimulation among the clones. This was most prominent with beta-endorphin, which stimulated [35S]GTPgammaS binding in the MOR-1E expressing cells to a greater degree than [D-Ala2,MePhe4,Gly(ol)5]enkephalin (DAMGO; 130%) and was far less effective than DAMGO in MOR-1C cells (44%). The rank order of maximal stimulation of the drugs varied among the clones as well. Dynorphin A, beta-endorphin and morphine were most effective in stimulating [35S]GTPgammaS binding in MOR-1E, while M6G and fentanyl were most effective in MOR-1 expressing cells. The potency (EC50) of some of the drugs also varied extensively among the clones, with a poor correlation between the potency of the drugs to stimulate [35S]GTPgammaS binding and their binding affinity. Together, these findings reveal marked functional differences among the variants that only can be explained by their structural differences at the tip of their C-terminus.
Publication
Journal: British Journal of Nutrition
October/10/2005
Abstract
Rats were fed a grape seed extract (GSE) containing (+)-catechin, (-)-epicatechin and dimers, trimers, tetramers and polymeric procyanidins. Liver, kidney, brain and gastrointestinal (GI) tract together with plasma, urine and faeces were collected over a 24 h period and their flavan-3-ol content was analysed by HPLC with tandem mass spectrometry and diode array detection. Small amounts of the GSE flavan-3-ols moved out of the stomach and into the duodenum/jejunum, and to a greater extent the ileum 1 h after ingestion, and into the caecum after 2 h with relatively small amounts being detected in the colon after 3 h. The GI tract contained the parent GSE flavan-3-ols and procyanidins with only trace amounts of metabolites and there were no indications that proanthocyanidins were depolymerised in the GI tract releasing monomeric flavan-3-ols. Plasma contained exclusively catechin glucuronides and methylated glucuronide metabolites which were also detected in the liver and kidneys. These metabolites were also present in urine together with sulphated metabolites and low amounts of the procyanidin dimers B1, B2, B3 and B4 as well as the trimer C2 and an unknown GSE trimer. The amounts of (+)-catechin and (-)-epicatechin metabolites excreted in urine relative to the quantity of the monomers ingested were 27 and 36 %, respectively, after 24 h. This is similar to the levels of urinary excretion reported to occur by other investigators after feeding (-)-epicatechin to rats and provides further, albeit indirect, evidence that the procyanidin oligomers in the GSE were not depolymerised to monomers to any extent after ingestion. No convincing analytical data were obtained for the presence of flavan-3-ol metabolites in the brain.
Publication
Journal: Current Biology
April/30/2013
Abstract
Compulsive overconsumption of reward characterizes disorders ranging from binge eating to drug addiction. Here, we provide evidence that enkephalin surges in an anteromedial quadrant of dorsal neostriatum contribute to generating intense consumption of palatable food. In ventral striatum, mu opioid circuitry contributes an important component of motivation to consume reward. In dorsal neostriatum, mu opioid receptors are concentrated within striosomes that receive inputs from limbic regions of prefrontal cortex. We employed advanced opioid microdialysis techniques that allow detection of extracellular enkephalin levels. Endogenous >150% enkephalin surges in anterior dorsomedial neostriatum were triggered as rats began to consume palatable chocolates. In contrast, dynorphin levels remained unchanged. Furthermore, a causal role for mu opioid stimulation in overconsumption was demonstrated by observations that microinjection in the same anterior dorsomedial quadrant of a mu receptor agonist ([D-Ala2, N-MePhe4, Gly-ol]-enkephalin; DAMGO) generated intense >250% increases in intake of palatable sweet food (without altering hedonic impact of sweet tastes). Mapping by "Fos plume" methods confirmed the hyperphagic effect to be anatomically localized to the anteromedial quadrant of the dorsal neostriatum, whereas other quadrants were relatively ineffective. These findings reveal that opioid signals in anteromedial dorsal neostriatum are able to code and cause motivation to consume sensory reward.
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