982 resultados para SECONDARY METABOLITES


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PURPOSE: The aim of this work is to investigate the characteristics of eyes failing to maintain visual acuity (VA) receiving variable dosing ranibizumab for neovascular age-related macular degeneration (nAMD) after three initial loading doses. METHODS: A consecutive series of patients with nAMD, who, after three loading doses of intravitreal ranibizumab (0.5 mg each), were re-treated for fluid seen on optical coherence tomography. After exclusion of eyes with previous treatment, follow-up less than 12 months, or missed visits, 99 patients were included in the analysis. The influence of baseline characteristics, initial VA response, and central retinal thickness (CRT) fluctuations on the VA stability from month 3 to month 24 were analyzed using subgroups and multiple regression analyses. RESULTS: Mean follow-up duration was 21.3 months (range 12-40 months, 32 patients followed-up for ≥24 months). Secondary loss of VA (loss of five letters or more) after month 3 was seen in 30 patients (mean VA improvement from baseline +5.8 letters at month 3, mean loss from baseline -5.3 letters at month 12 and -9.7 at final visit up to month 24), while 69 patients maintained vision (mean gain +8.9 letters at month 3, +10.4 letters at month 12, and +12.8 letters at final visit up to month 24). Secondary loss of VA was associated with the presence of pigment epithelial detachment (PED) at baseline (p 0.01), but not with baseline fibrosis/atrophy/hemorrhage, CRT fluctuations, or initial VA response. Chart analysis revealed additional individual explanations for the secondary loss of VA, including retinal pigment epithelial tears, progressive fibrosis, and atrophy. CONCLUSIONS: Tissue damage due to degeneration of PED, retinal pigment epithelial tears, progressive fibrosis, progressive atrophy, or massive hemorrhage, appears to be relevant in causing secondary loss of VA despite vascular endothelial growth factor suppression. PED at baseline may represent a risk factor.

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Ophthalmoplegia associated with dural carotid-cavernous sinus fistula typically involves the third, fourth, and sixth cranial nerves. Occasionally, isolated palsy of the oculomotor or abducens nerve is noted. We report a patient with bilateral dural carotid-cavernous sinus fistulas who presented with an isolated trochlear nerve palsy.

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Since 2004, cannabis has been prohibited by the World Anti-Doping Agency for all sports competitions. In the years since then, about half of all positive doping cases in Switzerland have been related to cannabis consumption. In doping urine analysis, the target analyte is 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH), the cutoff being 15 ng/mL. However, the wide urinary detection window of the long-term metabolite of Delta(9)-tetrahydrocannabinol (THC) does not allow a conclusion to be drawn regarding the time of consumption or the impact on the physical performance. The purpose of the present study on light cannabis smokers was to evaluate target analytes with shorter urinary excretion times. Twelve male volunteers smoked a cannabis cigarette standardized to 70 mg THC per cigarette. Plasma and urine were collected up to 8 h and 11 days, respectively. Total THC, 11-hydroxy-Delta(9)-tetrahydrocannabinol (THC-OH), and THC-COOH were determined after hydrolysis followed by solid-phase extraction and gas chromatography/mass spectrometry. The limits of quantitation were 0.1-1.0 ng/mL. Eight puffs delivered a mean THC dose of 45 mg. Plasma levels of total THC, THC-OH, and THC-COOH were measured in the ranges 0.2-59.1, 0.1-3.9, and 0.4-16.4 ng/mL, respectively. Peak concentrations were observed at 5, 5-20, and 20-180 min. Urine levels were measured in the ranges 0.1-1.3, 0.1-14.4, and 0.5-38.2 ng/mL, peaking at 2, 2, and 6-24 h, respectively. The times of the last detectable levels were 2-8, 6-96, and 48-120 h. Besides high to very high THC-COOH levels (245 +/- 1,111 ng/mL), THC (3 +/- 8 ng/mL) and THC-OH (51 +/- 246 ng/mL) were found in 65 and 98% of cannabis-positive athletes' urine samples, respectively. In conclusion, in addition to THC-COOH, the pharmacologically active THC and THC-OH should be used as target analytes for doping urine analysis. In the case of light cannabis use, this may allow the estimation of more recent consumption, probably influencing performance during competitions. However, it is not possible to discriminate the intention of cannabis use, i.e., for recreational or doping purposes. Additionally, pharmacokinetic data of female volunteers are needed to interpret cannabis-positive doping cases of female athletes.

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Combining measurements of the monoamine metabolites in the cerebrospinal fluid (CSF) and neuroimaging can increase efficiency of drug discovery for treatment of brain disorders. To address this question, we examined five drug-naïve patients suffering from schizophrenic disorder. Patients were assessed clinically, using the Positive and Negative Syndrome Scale (PANSS): at baseline and then at weekly intervals. Plasma and CSF levels of quetiapine and norquetiapine as well CSF 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxyindole-acetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were obtained at baseline and again after at least a 4 week medication trail with 600 mg/day quetiapine. CSF monoamine metabolites levels were compared with dopamine D(2) receptor occupancy (DA-D(2)) using [(18)F]fallypride and positron emission tomography (PET). Quetiapine produced preferential occupancy of parietal cortex vs. putamenal DA-D(2), 41.4% (p<0.05, corrected for multiple comparisons). DA-D(2) receptor occupancies in the occipital and parietal cortex were correlated with CSF quetiapine and norquetiapine levels (p<0.01 and p<0.05, respectively). CSF monoamine metabolites were significantly increased after treatment and correlated with regional receptor occupancies in the putamen [DOPAC: (p<0.01) and HVA: (p<0.05)], caudate nucleus [HVA: (p<0.01)], thalamus [MHPG: (p<0.05)] and in the temporal cortex [HVA: (p<0.05) and 5-HIAA: (p<0.05)]. This suggests that CSF monoamine metabolites levels reflect the effects of quetiapine treatment on neurotransmitters in vivo and indicates that monitoring plasma and CSF quetiapine and norquetiapine levels may be of clinical relevance.

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RATIONALE: The aim of the work was to develop and validate a method for the quantification of vitamin D metabolites in serum using ultra-high-pressure liquid chromatography coupled to mass spectrometry (LC/MS), and to validate a high-resolution mass spectrometry (LC/HRMS) approach against a tandem mass spectrometry (LC/MS/MS) approach using a large clinical sample set. METHODS: A fast, accurate and reliable method for the quantification of the vitamin D metabolites, 25-hydroxyvitamin D2 (25OH-D2) and 25-hydroxyvitamin D3 (25OH-D3), in human serum was developed and validated. The C3 epimer of 25OH-D3 (3-epi-25OH-D3) was also separated from 25OH-D3. The samples were rapidly prepared via a protein precipitation step followed by solid-phase extraction (SPE) using an HLB μelution plate. Quantification was performed using both LC/MS/MS and LC/HRMS systems. RESULTS: Recovery, matrix effect, inter- and intra-day reproducibility were assessed. Lower limits of quantification (LLOQs) were determined for both 25OH-D2 and 25OH-D3 for the LC/MS/MS approach (6.2 and 3.4 µg/L, respectively) and the LC/HRMS approach (2.1 and 1.7 µg/L, respectively). A Passing & Bablok fit was determined between both approaches for 25OH-D3 on 662 clinical samples (1.11 + 1.06x). It was also shown that results can be affected by the inclusion of the isomer 3-epi-25OH-D3. CONCLUSIONS: Quantification of the relevant vitamin D metabolites was successfully developed and validated here. It was shown that LC/HRMS is an accurate, powerful and easy to use approach for quantification within clinical laboratories. Finally, the results here suggest that it is important to separate 3-epi-25OH-D3 from 25OH-D3. Copyright © 2012 John Wiley & Sons, Ltd.

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Hypersensitivity pneumonitis (HP) is an immunologically mediated lung disease due to the repetitive inhalation of antigens. Most new cases arise from residential exposures, notably to birds, and are thus more difficult to recognise. The present authors report a 59-yr-old male who complained of dyspnoea and cough while being treated with amiodarone. Pulmonary function tests revealed restriction and obstruction with low diffusing lung capacity for carbon monoxide and partial pressure of oxygen. A high-resolution computed tomography chest scan and bronchoalveolar lavage showed diffuse bilateral ground-glass attenuation and lymphocytic alveolitis, respectively. Initial diagnosis was amiodarone pulmonary toxicity, but because of a rapidly favourable evolution, this diagnosis was questioned. A careful environmental history revealed a close contact with lovebirds shortly before the onset of symptoms. Precipitins were strongly positive against lovebird droppings, but were negative against other avian antigens. The patient was diagnosed with hypersensitivity pneumonitis to lovebirds. Avoidance of lovebirds and steroid treatment led to rapid improvement. The present observation identifies a new causative agent for hypersensitivity pneumonitis and highlights the importance of a thorough environmental history and of searching for precipitins against antigens directly extracted from the patient's environment. These two procedures should allow a more precise classification of some cases of pneumonitis, and thus might avoid progression of active undiagnosed hypersensitivity pneumonitis to irreversible fibrosis or emphysema.

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We report the case of a 6-month-old infant who presented with a complete duplication of the large intestine, debuting clinically with acute abdomen and severe metabolic disorders. We discuss the pathogenesis and morphology of the lesions, diagnostic difficulties and peculiarities of surgical treatment.

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The health benefits associated with the consumption of polyphenol-rich foods have been studied in depth, however, the full mechanism of action remains unknown. One of the proposed mechanisms is through microbiota interaction. In the present study, we aimed to explore the relationship between changes in fecal microbiota and changes in urinary phenolic metabolites after wine interventions. Nine participants followed a randomized, crossover, controlled interventional trial. After the washout period, they received red wine, dealcoholized red wine or gin for 20 days each. Polyphenol metabolites (n > 60) in urine were identified and quantified by UPLC-MS/MS and the microbial content of fecal samples was quantified by real-time quantitative PCR. Interventions with both red wine and dealcoholized red wine increased the fecal concentration of Bifidobacterium, Enterococcus and Eggerthella lenta, compared to gin intervention and baseline. When participants were categorized in tertiles of changes in fecal bacteria, those in the highest tertile of Bifidobacteria had higher urinary concentration changes in syringic acid, p-coumaric acid, 4-hydroxybenzoic acid and homovanillic acid (all anthocyanin metabolites) than those in tertile 1 (P < 0.05, all). In addition, changes of Bifidobacteria correlated positively with changes of these metabolites (r = 0.5-0.7, P < 0.05, all). Finally, the 68.5% changes in Bifidobacteria can be predicted by syringic acid and 4-hydroxybenzoic acid changes. This study confirms the important role of polyphenols as bacterial substrates and their modulatory capacity as an important field in the research of new products with prebiotic and probiotic characteristics for the food industry.

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Purpose : Secondary malignancies (SM) are a known long-­‐term problem in children surviving brain tumors. We report on two unusual cases of SM observed after treatment of ependymoma. Case reports : 1. The first case is a female survivor of a low-­‐grade ependymoma (Grade II). She had been treated at the age of 3 months with surgery and chemotherapy. A relapse of the primary tumor happened two years later, which was completely removed and treated with local radiotherapy to the posterior fossa. Fifteen years after the first cancer, she developed a pontine glioma near the location of the previous radiotherapy. 2. The second case is a femal survivor of an ependymoma (Grade III) which was removed and irradiated when she was 4 years old. The child developed a pontine glioma near the location of the previous radiotherapy ten years after the diagnosis of the first cancer. Further extension of the disease showed after biopsy PNET-­‐ like features. Both patients passed away. Discussion and Conclusion : Second malignant neoplasia is a rare phenomenon and this risk should not overshadow the great success in treating cancer of childhood. Among the studied risk factors, young age and radiotherapy are well established. The reported patients were followed annually to ensure their remission and both developed symptoms and an unusual unreported secondary cancer a few months after the annual monitoring that was considered as normal. This issue highlights the complexity of monitoring cancer survivors and raises the question of the best way for their long-­‐term follow-­‐up.

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In Pseudomonas aeruginosa, the catabolite repression control (Crc) protein repressed the formation of the blue pigment pyocyanin in response to a preferred carbon source (succinate) by interacting with phzM mRNA, which encodes a key enzyme in pyocyanin biosynthesis. Crc bound to an extended imperfect recognition sequence that was interrupted by the AUG translation initiation codon.

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Background: CYP2D6 is the key enzyme responsible for tamoxifen bioactivation mainly into endoxifen. This gene is highly polymorphic and breast cancer patients classified as CYP2D6 poor metabolizers (PM) or intermediate metabolizers (IM) appear to show low concentrations of endoxifen and to achieve less benefit from tamoxifen treatment. Purpose: This prospective, open-label trial aimed to assess how the increase of tamoxifen dose influences the level of endoxifen in the different genotype groups (poor-, intermediate-, and extensive-metabolizers (EM)). We examined the impact of doubling tamoxifen dose to 20mg twice daily on endoxifen plasma concentrations across these genotype groups. Patients and methods: Patients were assayed for CYP2D6 genotype and phenotype using dextromethorphan test. Tamoxifen, N-desmethyltamoxifen, 4-hydroxytamoxifen and endoxifen plasma levels were determined on 2 occasions at baseline (20mg/day of tamoxifen) and at day 30, 90 and 120 after dose increase (20 mg twice daily) using liquid chromatography-tandem-mass spectrometry. Endoxifen plasma levels were measured 6 to 24 hours after last drug intake to evaluate its accumulation before and after doubling tamoxifen dosage. ANOVA was used to evaluate endoxifen levels increase and difference between genotype groups. Results: 63 patients are available for analysis to date. Tamoxifen, N-desmethyltamoxifen, 4-hydroxytamoxifen and endoxifen plasma reached steady state at 30 day after tamoxifen dose escalation, with a significant increase compared to baseline by 1.6 to 1.8 fold : geometric mean plasma concentrations (CV %) were 140 ng/mL (45%) at baseline vs 255 (47%) at day 30 for tamoxifen (P < 0.0001); 256 (49%) vs 408 (64%) for N-desmethyltamoxifen (P < 0.0001); 2.4 (46%) vs 3.9 (51%) for 4-OH-tamoxifen (P < 0.0001); and 20 (91%) vs 33 (91%) for endoxifen (P < 0.02). On baseline, endoxifen levels tended to be lower in PM: 7 ng/mL (36%), than IM: 16 ng/mL (70%), P=0.08, and EM: 24 ng/mL (71%), P<0.001. After doubling tamoxifen dosage, endoxifen concentrations rose similarly in PM, IM and EM with respectively, 1.5 (18%), 1.5 (28%) and 1.7 (30%) fold increase from baseline, P=0.18. Conclusion: Endoxifen exposure varies widely under standard tamoxifen dosage, with CYP2D6 genotype explaining only a minor part of this variability. It increases consistently on doubling tamoxifen dose, similarly across genotypes. This would enable exposure optimization based on concentration monitoring.

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Bioactive small molecules, such as drugs or metabolites, bind to proteins or other macro-molecular targets to modulate their activity, which in turn results in the observed phenotypic effects. For this reason, mapping the targets of bioactive small molecules is a key step toward unraveling the molecular mechanisms underlying their bioactivity and predicting potential side effects or cross-reactivity. Recently, large datasets of protein-small molecule interactions have become available, providing a unique source of information for the development of knowledge-based approaches to computationally identify new targets for uncharacterized molecules or secondary targets for known molecules. Here, we introduce SwissTargetPrediction, a web server to accurately predict the targets of bioactive molecules based on a combination of 2D and 3D similarity measures with known ligands. Predictions can be carried out in five different organisms, and mapping predictions by homology within and between different species is enabled for close paralogs and orthologs. SwissTargetPrediction is accessible free of charge and without login requirement at http://www.swisstargetprediction.ch.

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This study was conducted to identify enzyme systems eventually catalysing a local cerebral metabolism of citalopram, a widely used antidepressant of the selective serotonin reuptake inhibitor type. The metabolism of citalopram, of its enantiomers and demethylated metabolites was investigated in rat brain microsomes and in rat and human brain mitochondria. No cytochrome P-450 mediated transformation was observed in rat brain. By analysing H2O2 formation, monoamine oxidase A activity in rat brain mitochondria could be measured. In rat whole brain and in human frontal cortex, putamen, cerebellum and white matter of five brains monoamine oxidase activity was determined by the stereoselective measurement of the production of citalopram propionate. All substrates were metabolised by both forms of MAO, except in rat brain, where monoamine oxidase B activity could not be detected. Apparent Km and Vmax of S-citalopram biotransformation in human frontal cortex by monoamine oxidase B were found to be 266 microM and 6.0 pmol min(-1) mg(-1) protein and by monoamine oxidase A 856 microM and 6.4 pmol min(-1) mg(-1) protein, respectively. These Km values are in the same range as those for serotonin and dopamine metabolism by monoamine oxidases. Thus, the biotransformation of citalopram in the rat and human brain occurs mainly through monoamine oxidases and not, as in the liver, through cytochrome P-450.

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We characterize divergence times, intraspecific diversity and distributions for recently recognized lineages within the Hyla arborea species group, based on mitochondrial and nuclear sequences from 160 localities spanning its whole distribution. Lineages of H. arborea, H. orientalis, H. molleri have at least Pliocene age, supporting species level divergence. The genetically uniform Iberian H. molleri, although largely isolated by the Pyrenees, is parapatric to H. arborea, with evidence for successful hybridization in a small Aquitanian corridor (southwestern France), where the distribution also overlaps with H. meridionalis. The genetically uniform H. arborea, spread from Crete to Brittany, exhibits molecular signatures of a postglacial range expansion. It meets different mtDNA clades of H. orientalis in NE-Greece, along the Carpathians, and in Poland along the Vistula River (there including hybridization). The East-European H. orientalis is strongly structured genetically. Five geographic mitochondrial clades are recognized, with a molecular signature of postglacial range expansions for the clade that reached the most northern latitudes. Hybridization with H. savignyi is suggested in southwestern Turkey. Thus, cryptic diversity in these Pliocene Hyla lineages covers three extremes: a genetically poor, quasi-Iberian endemic (H. molleri), a more uniform species distributed from the Balkans to Western Europe (H. arborea), and a well-structured Asia Minor-Eastern European species (H. orientalis).