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1.
Pathologe ; 38(1): 11-20, 2017 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-28154917

RESUMEN

Recently a new TNM classification for tumors of the lung was published, encompassing some relevant changes, for example how to deal with multiple lung tumors. This article comprehensively describes respective changes. Furthermore, background information on how the new TNM classification was built and what should be done in the future to further improve prognosis and outcome prediction is reviewed.


Asunto(s)
Neoplasias Pulmonares/clasificación , Neoplasias Pulmonares/patología , Estadificación de Neoplasias/métodos , Humanos , Pulmón/patología , Ganglios Linfáticos/patología , Clasificación del Tumor , Neoplasias Primarias Múltiples/patología , Pronóstico
2.
Anal Chem ; 86(9): 4110-4, 2014 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-24650176

RESUMEN

To optimize the quality of large scale mass-spectrometry based metabolomics data obtained from semiquantitative profiling measurements, it is important to use a strategy in which dedicated measurement designs are combined with a strict statistical quality control regime. This assures consistently high-quality results across measurements from individual studies, but semiquantitative data have been so far only comparable for samples measured within the same study. To enable comparability and integration of semiquantitative profiling data from different large scale studies over the time course of years, the measurement and quality control strategy has to be extended. We introduce a strategy to allow the integration of semiquantitative profiling data from different studies. We demonstrate that lipidomics data generated in samples from three different large biobanks acquired in the time course of 3 years can be effectively combined when using an appropriate measurement design and transfer model. This strategy paves the way toward an integrative usage of semiquantitative metabolomics data sets of multiple studies to validate biological findings in another study and/or to increase the statistical power for discovery of biomarkers or pathways by combining studies.


Asunto(s)
Metabolómica , Bancos de Tejidos , Cromatografía Liquida , Espectrometría de Masas , Control de Calidad
3.
Nat Commun ; 14(1): 3754, 2023 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-37365181

RESUMEN

Dopaminergic cell loss due to the accumulation of α-syn is a core feature of the pathogenesis of Parkinson disease. Neuroinflammation specifically induced by α-synuclein has been shown to exacerbate neurodegeneration, yet the role of central nervous system (CNS) resident macrophages in this process remains unclear. We found that a specific subset of CNS resident macrophages, border-associated macrophages (BAMs), play an essential role in mediating α-synuclein related neuroinflammation due to their unique role as the antigen presenting cells necessary to initiate a CD4 T cell response whereas the loss of MHCII antigen presentation on microglia had no effect on neuroinflammation. Furthermore, α-synuclein expression led to an expansion in border-associated macrophage numbers and a unique damage-associated activation state. Through a combinatorial approach of single-cell RNA sequencing and depletion experiments, we found that border-associated macrophages played an essential role in immune cell recruitment, infiltration, and antigen presentation. Furthermore, border-associated macrophages were identified in post-mortem PD brain in close proximity to T cells. These results point to a role for border-associated macrophages in mediating the pathogenesis of Parkinson disease through their role in the orchestration of the α-synuclein-mediated neuroinflammatory response.


Asunto(s)
Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Enfermedades Neuroinflamatorias , Macrófagos/metabolismo , Inflamación/patología , Microglía/metabolismo
4.
Gut Microbes ; 13(1): 1-22, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33590776

RESUMEN

The interaction disorder between gut microbiota and its host has been documented in different non-communicable diseases (NCDs) such as metabolic syndrome, neurodegenerative disease, and autoimmune disease. The majority of these altered interactions arise through metabolic cross-talk between gut microbiota and host immune system, inducing a low-grade chronic inflammation that characterizes all NCDs. In this review, we discuss the contribution of bacterial metabolites to immune signaling pathways involved in NCDs. We then review recent advances that aid to rationally design microbial therapeutics. A deeper understanding of these intersections between host and gut microbiota metabolism using metabolomics-based system biology platform promises to reveal the fundamental mechanisms that drive metabolic predispositions to disease and suggest new avenues to use microbial therapeutic opportunities for NCDs treatment and prevention. Abbreviations: NCDs: non-communicable disease, IBD: inflammatory bowel disease, IL: interleukin, T2D: type 2 diabetes, SCFAs: short-chain fatty acids, HDAC: histone deacetylases, GPCR: G-protein coupled receptors, 5-HT: 5-hydroxytryptamine receptor signaling, DCs: dendritic cells, IECs: intestinal epithelial cells, T-reg: T regulatory cell, NF-κB: nuclear factor κB, TNF-α: tumor necrosis factor alpha, Th: T helper cell, CNS: central nervous system, ECs: enterochromaffin cells, NSAIDs: non-steroidal anti-inflammatory drugs, AhR: aryl hydrocarbon receptor, IDO: indoleamine 2,3-dioxygenase, QUIN: quinolinic acid, PC: phosphatidylcholine, TMA: trimethylamine, TMAO: trimethylamine N-oxide, CVD: cardiovascular disease, NASH: nonalcoholic steatohepatitis, BAs: bile acids, FXR: farnesoid X receptor, CDCA: chenodeoxycholic acid, DCA: deoxycholic acid, LCA: lithocholic acid, UDCA: ursodeoxycholic acid, CB: cannabinoid receptor, COBRA: constraint-based reconstruction and analysis.


Asunto(s)
Bacterias/metabolismo , Microbioma Gastrointestinal/fisiología , Enfermedades no Transmisibles , Transducción de Señal/inmunología , Amidas/inmunología , Amidas/metabolismo , Bacterias/clasificación , Bacterias/aislamiento & purificación , Ácidos y Sales Biliares/inmunología , Ácidos y Sales Biliares/metabolismo , Colina/inmunología , Colina/metabolismo , Susceptibilidad a Enfermedades/inmunología , Susceptibilidad a Enfermedades/microbiología , Ácidos Grasos Volátiles/inmunología , Ácidos Grasos Volátiles/metabolismo , Humanos , Sistema Inmunológico/inmunología , Indoles/inmunología , Indoles/metabolismo , Poliaminas/inmunología , Poliaminas/metabolismo , Vitaminas/inmunología , Vitaminas/metabolismo
5.
Mar Pollut Bull ; 159: 111490, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32738641

RESUMEN

Laboratories from 14 countries (with different levels of expertise in radionuclide measurements and 210Pb dating) participated in an interlaboratory comparison exercise (ILC) related to the application of 210Pb sediment dating technique within the framework of the IAEA Coordinated Research Project. The laboratories were provided with samples from a composite sediment core and were required to provide massic activities of several radionuclides and an age versus depth model from the obtained results, using the most suitable 210Pb dating model. Massic concentrations of Zn and Cu were also determined to be used for chronology validation. The ILC results indicated good analytical performances while the dating results didn't demonstrate the same degree of competence in part due to the different experience in dating of the participant laboratories. The ILC exercise enabled evaluation of the difficulties faced by laboratories implementing 210Pb dating methods and identified some limitations in providing reliable chronologies.


Asunto(s)
Radioisótopos de Plomo/análisis , Plomo , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Radiometría
7.
Sci Rep ; 9(1): 5797, 2019 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-30940838

RESUMEN

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

8.
Lung Cancer ; 118: 76-82, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29572007

RESUMEN

OBJECTIVES: Large cell neuroendocrine carcinoma of the lung (LCNEC) is associated with an unfavorable prognosis and only few patients are eligible for surgery. In most patients, chemotherapy is recommended alone or in addition to resection. Novel immunotherapies blocking the PD-L1 pathway have been introduced into therapeutic regimens for NSCLC with great success. In order to evaluate a possible efficacy of an anti-PD-L1 therapy, we analyzed the frequency of PD-L1 expression in LCNEC. MATERIAL AND METHODS: We retrospectively reviewed data from 76 patients with LCNEC treated in our institution between 1998 and 2010. The expression of PD-L1 was examined on the tumor cells and the tumor surrounding tissue by immunohistochemistry. An expression of >1% was considered as positive. Statistical analysis was performed to determine significant predictors for survival. RESULTS: 56 of 76 patients with LCNEC were treated with a potentially therapeutic surgical approach. Tumor-specific survival (TSS) of the entire cohort was 29% at five years. 17 patients (22.3%) had PD-L1 positive tumors and 12 of these had no additional PD-L1 expression in the adjacent immune cell infiltrate. Tumor-flanking immune cells were found PD-L1 positive 28 patients; 16 of these had no additional expression on the tumor cells. The most considerable difference in survival was found when comparing patients with isolated PD-L1 expression on tumor cells and PD-L1 negative immune cell infiltrate to their counterpart (positive immune-cell infiltrate and PD-L1 negative tumor cell surface; 5-year TSS: 0% vs. 60%; p < 0.017). CONCLUSION: PD-L1 expression in LCNEC was associated with poorer survival whereas PD-L1 expression in the tumor microenvironment seemed to have a beneficial effect. Therapeutic approaches have to be evaluated in future.


Asunto(s)
Antígeno B7-H1/metabolismo , Carcinoma Neuroendocrino/metabolismo , Neoplasias Pulmonares/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Neuroendocrino/diagnóstico , Carcinoma Neuroendocrino/mortalidad , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Microambiente Tumoral
9.
Sci Rep ; 8(1): 14568, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30275458

RESUMEN

The menstrual cycle is an essential life rhythm governed by interacting levels of progesterone, estradiol, follicular stimulating, and luteinizing hormones. To study metabolic changes, biofluids were collected at four timepoints in the menstrual cycle from 34 healthy, premenopausal women. Serum hormones, urinary luteinizing hormone and self-reported menstrual cycle timing were used for a 5-phase cycle classification. Plasma and urine were analyzed using LC-MS and GC-MS for metabolomics and lipidomics; serum for clinical chemistries; and plasma for B vitamins using HPLC-FLD. Of 397 metabolites and micronutrients tested, 208 were significantly (p < 0.05) changed and 71 reached the FDR 0.20 threshold showing rhythmicity in neurotransmitter precursors, glutathione metabolism, the urea cycle, 4-pyridoxic acid, and 25-OH vitamin D. In total, 39 amino acids and derivatives and 18 lipid species decreased (FDR < 0.20) in the luteal phase, possibly indicative of an anabolic state during the progesterone peak and recovery during menstruation and the follicular phase. The reduced metabolite levels observed may represent a time of vulnerability to hormone related health issues such as PMS and PMDD, in the setting of a healthy, rhythmic state. These results provide a foundation for further research on cyclic differences in nutrient-related metabolites and may form the basis of novel nutrition strategies for women.


Asunto(s)
Factores Biológicos/análisis , Ciclo Menstrual , Metaboloma , Periodicidad , Adulto , Análisis Químico de la Sangre , Cromatografía de Gases , Cromatografía Liquida , Femenino , Voluntarios Sanos , Humanos , Espectrometría de Masas , Metabolómica , Urinálisis , Adulto Joven
10.
Cardiovasc Intervent Radiol ; 41(9): 1404-1411, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29858644

RESUMEN

PURPOSE: To investigate radiopacity, size and size calibration, morphology, and vascular distribution of inherently radiopaque microspheres in vitro and in a pig embolization model. MATERIALS AND METHODS: We compared three types of microspheres: DCBead™ (size 100-300 µm) and Embozene™ (250 µm) as clinically established microspheres, and the prototype Visible (250 µm) that contains additional radiopaque material. Size and size calibration of microspheres were examined by laser diffraction. Pulmonary artery embolization was performed in 12 pigs, and radiopacity was examined by in vitro micro-computed tomography (CT), in vivo cone-beam CT, and ex vivo micro-CT after killing. Morphology and vascular distribution of microspheres were microscopically examined. RESULTS: In in vitro and ex vivo micro-CT, radiopacity of Visible was higher than that of Embozene™, whereas DCBead™ showed no radiopacity. In in vivo cone-beam CT, radiopacity was observed with Visible but not with Embozene™ and DCBead™. Laser diffraction revealed that 7.0% (Visible), 6.5% (Embozene™), and 22.5% (DCBead™) of microspheres were smaller than 223.5 µm. Visible and Embozene™ microspheres were very often located in bronchiolus-associated arteries, but rarely in subsegmental and capillary arteries, whereas DCBead™ were very often and often detected in bronchiolus-associated arteries and capillary arteries, respectively (and rarely in subsegmental arteries). CONCLUSION: After pulmonary artery embolization, Visible but not Embozene™ or DCBead™ provide in vivo radiopacity in cone-beam CT. In contrast to non-narrow-size-calibrated DCBead™, pulmonary artery embolization with narrow-size-calibrated Visible and Embozene™ result in a predictable arterial distribution without embolization-related hemorrhagic lung infarction.


Asunto(s)
Embolización Terapéutica/métodos , Microesferas , Arteria Pulmonar/diagnóstico por imagen , Microtomografía por Rayos X/métodos , Animales , Modelos Animales , Porcinos
11.
Eur J Pharm Sci ; 109: 431-440, 2017 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-28882765

RESUMEN

The study of central nervous system (CNS) pharmacology is limited by a lack of drug effect biomarkers. Pharmacometabolomics is a promising new tool to identify multiple molecular responses upon drug treatment. However, the pharmacodynamics is typically not evaluated in metabolomics studies, although being important properties of biomarkers. In this study we integrated pharmacometabolomics with pharmacokinetic/pharmacodynamic (PKPD) modeling to identify and quantify the multiple endogenous metabolite dose-response relations for the dopamine D2 antagonist remoxipride. Remoxipride (vehicle, 0.7 or 3.5mg/kg) was administered to rats. Endogenous metabolites were analyzed in plasma using a biogenic amine platform and PKPD models were derived for each single metabolite. These models were clustered on basis of proximity between their PKPD parameter estimates, and PKPD models were subsequently fitted for the individual clusters. Finally, the metabolites were evaluated for being significantly affected by remoxipride. In total 44 metabolites were detected in plasma, many of them showing a dose dependent decrease from baseline. We identified 6 different clusters with different time and dose dependent responses and 18 metabolites were revealed as potential biomarker. The glycine, serine and threonine pathway was associated with remoxipride pharmacology, as well as the brain uptake of the dopamine and serotonin precursors. This is the first time that pharmacometabolomics and PKPD modeling were integrated. The resulting PKPD cluster model described diverse pharmacometabolomics responses and provided a further understanding of remoxipride pharmacodynamics. Future research should focus on the simultaneous pharmacometabolomics analysis in brain and plasma to increase the interpretability of these responses.


Asunto(s)
Antagonistas de Dopamina/farmacología , Antagonistas de Dopamina/farmacocinética , Metabolómica , Modelos Biológicos , Remoxiprida/farmacología , Remoxiprida/farmacocinética , Animales , Biomarcadores/metabolismo , Antagonistas de Dopamina/sangre , Masculino , Análisis Multivariante , Ratas Wistar , Remoxiprida/sangre
12.
Int J Impot Res ; 18(3): 229-35, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16239897

RESUMEN

This meta-analytic study aims to estimate the likely improvements of erectile dysfunction (ED) measured by the International Index of Erectile Function (IIEF) at the highest fixed dosages of the three available PDE-5-inhibitors: sildenafil, tadalafil, and vardenafil. MEDLINE and the Cochrane Library were searched electronically for efficacy trials of PDE-5-inhibitors for treating ED. In addition drug manufacturers were contacted to provide unpublished or unrecorded congress proceedings. Randomized, double-blind, placebo-controlled, parallel-group, maximum fixed-dose, broad-spectrum efficacy trials using IIEF were included in the analysis. Data were independently extracted by two reviewers. The results were pooled using weighted mean differences. A formal indirect comparison (including Bonferroni-correction) was conducted to estimate the differences between agents. A total of 14 trials were included in the meta-analysis (three with 100 mg sildenafil, eight with 20-25 mg tadalafil, and three with 20 mg vardenafil). All trials were of good methodological quality. Overall heterogeneity was moderate: I(2)=33.2%, chi(2)=19.47, P=0.11. The funnel plot suggested moderate likelihood of publication bias. Pooled results of IIEF-improvement were for sildenafil 9.65 (95% CI: 8.50, 10.79) points, tadalafil 8.52 (7.61, 9.42) points, and vardenafil 7.50 (6.50, 8.50) points, respectively. Sildenafil proved to be significantly more effective than vardenafil (d=2.15, P=0.006), other pairwise comparisons showed no difference in efficacy. All PDE-5-inhibitors are highly effective in the treatment of ED. At maximum dosage they improve erectile function 7-10 points on the IIEF compared to placebo-treatment. There is evidence that sildenafil might be more efficacious than vardenafil, although this is to be interpreted with caution. To prove higher efficacy truly independent comparative trials are needed.


Asunto(s)
Disfunción Eréctil/tratamiento farmacológico , Disfunción Eréctil/enzimología , Inhibidores de Fosfodiesterasa/administración & dosificación , Inhibidores de Fosfodiesterasa/uso terapéutico , Hidrolasas Diéster Fosfóricas/metabolismo , Ensayos Clínicos Controlados Aleatorios como Asunto , 3',5'-GMP Cíclico Fosfodiesterasas , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5 , Método Doble Ciego , Disfunción Eréctil/fisiopatología , Humanos , Cooperación Internacional , Masculino
13.
Int J Impot Res ; 18(6): 559-65, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16688210

RESUMEN

Several trials and reviews provide evidence for the efficacy of phosphodiesterase-5 inhibitors in the treatment of erectile dysfunction (ED). However, little is known about the impact of treatment effect modifiers other than concomitant diseases. Our objective was to identify patient and trial characteristics as well as methodological and publication-related issues that are associated with the treatment effect measured in flexible-dose randomized controlled trials of oral sildenafil for ED. The MEDLINE and the Cochrane Central databases were searched for efficacy trials of sildenafil. Thirteen trials fulfilled all inclusion criteria. A series of meta-regression and graphical analyses were performed to test the impact of possible effect modifiers. Treatment effect was influenced by mean baseline disease severity and mean duration of the disease. These associations were at least partly mediated by placebo response. Trial duration, age of patients and etiology of ED in patients did not have any significant influence on the treatment effect. The year of publication of primary trials was also related to trial findings. Our analysis adds important data to enable the control of confounding variables in future trials and meta-analyses. It might also help the individual to assess the unbiased efficacy and true innovative potential of available and forthcoming pharmacological agents.


Asunto(s)
Ensayos Clínicos como Asunto , Disfunción Eréctil/tratamiento farmacológico , Inhibidores de Fosfodiesterasa/uso terapéutico , Piperazinas/administración & dosificación , Piperazinas/uso terapéutico , Administración Oral , Relación Dosis-Respuesta a Droga , Humanos , Masculino , Inhibidores de Fosfodiesterasa/administración & dosificación , Purinas , Análisis de Regresión , Citrato de Sildenafil , Sulfonas
14.
Appl Radiat Isot ; 64(10-11): 1242-7, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16549359

RESUMEN

The National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) for seaweed was developed through an interlaboratory comparison with 24 participants from 16 countries. After evaluating different techniques to calculate certified values for the radionuclides, the median method was found to be the most representative technique. The certified values were provided for 13 radionuclides and information values were given for 15 more radionuclides. Results for the natural decay series showed disequilibrium in both the uranium and thorium series.


Asunto(s)
Guías como Asunto , Monitoreo de Radiación/normas , Radioisótopos/análisis , Radioisótopos/normas , Estándares de Referencia , Algas Marinas/química , Contaminantes Radiactivos del Agua/análisis , Cooperación Internacional , Dosis de Radiación , Monitoreo de Radiación/métodos , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Contaminantes Radiactivos del Agua/normas
15.
Appl Radiat Isot ; 108: 143-147, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26720263

RESUMEN

The radioactive decay half-life of the ß(-)-emitter (111)Ag has been measured using decay transitions identified using a high purity germanium γ-ray spectrometer. The time series of measurements of the net peak areas of the 96.8 keV, 245.4 keV and 342.1 keV γ-ray emissions following the ß(-) decay of (111)Ag were made over approximately 23 days, i.e. ~3 half-life periods. The measured half-life of the ground state decay of (111)Ag was determined as 7.423 (13) days which is consistent with the Evaluated Nuclear Structure Data File (ENSDF) recommended half-life of 7.45 (1) days at k=2. Utilising all available experimental half-life values, a revised recommended half-life of 7.452 (12) days has been determined.

16.
J Environ Radioact ; 162-163: 358-370, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27348041

RESUMEN

Basic equations for age dating through activity ratio measurements are presented and applied to nuclear chronometers based on parent-daughter decay. Uncertainty propagation formulae are derived which relate the relative uncertainty on the half-lives and measured activity ratios with the relative uncertainty on the calculated time of a nuclear event. Particular attention is paid to the case of relatively short-lived radionuclides for which the change in decay rate during the measurement is non-negligible. Mathematical solutions are presented to correct the perceived activity ratio and adapt the uncertainty propagation formulae to complete the uncertainty budget. The formulae have been applied to 140Ba-140La chronometry, which is particularly useful for dating a nuclear explosion through measurement of the produced activity ratio of 140La and 140Ba in a finite time interval. They were also applied to the 227Th-223Ra parent-daughter pair produced for therapeutic use. The impact of inaccuracies in the nuclear decay data on the performance of these nuclear chronometers is shown and discussed.


Asunto(s)
Bario/análisis , Lantano/análisis , Torio/análisis , Radiactividad , Radioisótopos/análisis , Radio (Elemento)/análisis , Incertidumbre
17.
Appl Radiat Isot ; 109: 101-104, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26631455

RESUMEN

The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training.


Asunto(s)
Sedimentos Geológicos/análisis , Radioisótopos/análisis , Radioisótopos/normas , Radiometría/normas , Contaminantes Radiactivos del Suelo/análisis , Contaminantes Radiactivos del Suelo/normas , Certificación/normas , Sedimentos Geológicos/química , Micronesia , Océano Pacífico , Radioisótopos/química , Valores de Referencia , Contaminantes Radiactivos del Suelo/química
18.
J Immunol Methods ; 20: 17-23, 1978.
Artículo en Inglés | MEDLINE | ID: mdl-418116

RESUMEN

Using corresponding monospecific antisera from the rabbit, the precipitation curves for albumin, alpha-1-antitrypsin, haptoglobin 1-1 and fibrinogen were produced. In parallel, four different dilutions of these antigens were examined by line immmunoelectrophoresis, employing the same antisera. The distance of the resulting line immune precipitates from the start served to calculate the amount of antigen-antiserum reacting with each other. After converting these values to the amount of antiserum used for producing the precipitation curves, the 'line antigen/antibody ratios' were drawn into the appropriate precipitation curves. All electroimmune precipitates (in this case, the 'line immune precipitates') were found to be located on the side of antigen excess of their corresponding precipitation curve.


Asunto(s)
Inmunoelectroforesis , Animales , Reacciones Antígeno-Anticuerpo , Antígenos , Precipitación Química , Inmunodifusión , Inmunoglobulinas , Peso Molecular , Conejos
19.
J Biomol Screen ; 5(4): 269-78, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10992048

RESUMEN

A high throughput screening method for the analysis of 5-hydroxytryptamine(2A) (5-HT(2A)) receptor binding parameters has been developed, using 96-well filter plates of the Millipore MultiScreen system in combination with a MicroBeta PLUS microplate scintillation counter. MAFB filter plates (GF/B filter over a Durapore membrane) were used because of the lower nonspecific binding of the radioligand to GF/B filter material than to GF/C filters. Comparing different scintillation cocktails, highest counting efficiency and shortest equilibration time were detected with Betaplatescint, after drying the plates at 50 degrees C for 2 h. Measuring the plates without the plastic underdrain increased the counting efficiency by about 39% as compared with counting the plate with the underdrain intact. Presoaking the wells with 0.5% polyethyleneimine for 2 h reduced the nonspecific binding to the filter material by about 50%. A linear relationship of protein concentration and radioligand binding was established up to a protein concentration of 165 microg of protein/well. In the assays, 70 microg of protein/well was generally used, which has turned out to be favorable with respect to the number of counts obtained. When a higher concentration of protein was used, the period of time needed to aspirate the plate was too long because of obstruction of the filter material. Receptor-radioligand equilibration was reached after about 20 min at concentrations less than 0.05 nM [(3)H]ketanserin-HCl; at higher concentrations it was reached after about 10 min. Saturation analysis of [(3)H]ketanserin-HCl resulted in a mean B(max) of 393 fmol/mg protein and a K(D) of 2.0 nM using rat frontal cortex as a receptor source. Competition experiments with known 5-HT(2A) receptor ligands-DOB-HCl (K(i) = 59 nM), DOET-HCl (K(i) = 137 nM), DOM-HCl (K(i) = 533 nM), DMT (K(i) = 1,985 nM), and TMA-HCl (K(i) = 22,340 nM)-were in accordance with literature values.


Asunto(s)
Evaluación Preclínica de Medicamentos/métodos , Ensayo de Unión Radioligante/métodos , Receptores de Serotonina/metabolismo , Animales , Unión Competitiva , Encéfalo/metabolismo , Evaluación Preclínica de Medicamentos/instrumentación , Técnicas In Vitro , Ketanserina/metabolismo , Cinética , Ensayo de Unión Radioligante/instrumentación , Ratas , Receptor de Serotonina 5-HT2A , Conteo por Cintilación/instrumentación , Conteo por Cintilación/métodos
20.
J Am Soc Mass Spectrom ; 9(5): 510-5, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9879365

RESUMEN

Electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometry has been used to characterize heterotetrameric corynebacterial sarcosine oxidase. By using a conventional quadrupole mass spectrometer, no spectra for the intact complex could be obtained (i.e., electrospraying protein at neutral pH), but spectra showing the four protein subunits were obtained when electrospraying from acidic solution. Initial low resolution ESI-FTICR mass spectra of the intact heterotetramer revealed a typical narrow charge state distribution in the range 6000 < m/z < 9000, consistent with retention of a compact structure in the gas phase, and gave a mass measurement about 1000 u higher than predicted. Efficient in-trap clean up, based upon low energy collisionally induced dissociation of adducts, allowed significant improvement in mass measurement accuracy. The present results represent the largest heteromultimeric protein complex successfully analyzed using FTICR mass spectrometry, and clearly illustrate the importance of sample clean up methods for large molecule characterization.


Asunto(s)
Isoenzimas/análisis , Oxidorreductasas N-Desmetilantes/análisis , Corynebacterium/enzimología , Espectrometría de Masas , Sarcosina-Oxidasa
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