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BACKGROUND: Antithrombin deficiency (ATD) is an autosomal dominant thrombophilia presenting with varying phenotypes. In pediatric patients with ATD, thrombosis typically develops during the neonatal period or adolescence. However, to date there are no consistent recommendations on the therapeutic management of children with ATD. Inferior vena cava atresia (IVCA) belongs to a range of congenital or acquired vena cava malformations and is described as an independent risk factor for thrombosis. The present case report explores two cases of combined ATD and IVCA in an adolescent and his mother. CASE PRESENTATION: A 14-year-old male presented with extensive deep venous thromboses (DVTs) of both lower extremities as well as an IVCA. The patient had previously been diagnosed with an asymptomatic ATD without therapeutic consequences at that time. His mother was suffering from an ATD and had herself just been diagnosed with IVCA, too. The DVTs in the adolescent were treated by systemic anticoagulation and catheter-directed local thrombolysis causing favourable results. Yet, despite adequate oral anticoagulation the DVTs in both lower extremities reoccurred within 1 week after the patient was discharged from hospital. This time, thrombolysis could not be fully achieved. Surprisingly, probing and stenting of the IVCA was achieved, indicating an acquired IVCA which could have occurred after undetected thrombosis in early childhood. Genetic analyses showed the same mutation causing ATD in both son and mother: heterozygote missense mutation c.248 T > C, p.(Leu83Pro), within the heparin binding domain of antithrombin. This mutation was never reported in mutation databases before. CONCLUSIONS: To our knowledge this is the first case report discussing combined ATD and IVCA in two family members. Since ATDs present with clinical heterogeneity, taking a thorough family history is crucial for the anticipation of possible complications in affected children and decisions on targeted diagnostics and therapeutic interventions. Affected families must be educated on risk factors and clinical signs of thrombosis and need an immediate diagnostic workup in case of clinical symptoms. IVCA in patients with ATD could occur due to thrombotic occlusion at a very early age. Therefore, in case of family members with IVCA and ATD ultrasound screening in newborns should be considered.
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Microplastics are small plastic fragments that have been found around the world, however, research into microplastics in Africa and freshwater systems remains insufficient. In this study, the snapshot microplastic profile of an urban stream was assessed in the Braamfontein Spruit, located in Johannesburg the largest city in South Africa. The abundance of microplastics was determined in water, Chironomus sp. larvae and sediment, while in situ parameters were taken to investigate their relationship to the microplastic profile of the different matrices. Microplastics were detected in water (mean of 705 particles m-3), Chironomus sp. larvae (mean of 53.4 particles g-1 wet weight) and sediment (mean of 166.8 particles kg-1 dry weight). The study found evidence of how urban stream characteristics such as a weir, stream depth and velocity could affect the abundance and dispersion of microplastics. The results indicate that areas of increased depth and decreased flow allowed microplastics to settle down to the sediment where benthic macroinvertebrates could ingest these fragments. Large obstructions like a weir also increased microplastic counts in sediment and invertebrates above the obstruction, with a decrease of fragments after the obstruction, however, microplastics in surface water were able to flow over the obstruction and increase in abundance downstream. This study concludes that first order urban streams such as the Braamfontein Spruit may be contributing large numbers of microplastics to higher order streams and large rivers in times of increased flow.
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AIM: The extracellular matrix protein ED-B fibronectin (ED-B) is upregulated in inflammatory atherosclerotic lesions. However, functional in vivo imaging of ED-B-containing plaques has not been explored. This study evaluated whether [(99m)Tc]-conjugated AP39 ([(99m)Tc]-AP39), a single-chain antibody specific to ED-B, can be used for in vivo detection of atherosclerotic plaques in Western diet (WD)-fed, apolipoprotein E-deficient (apoE-/-) mice as compared to wildtype (WT) control mice. METHODS: Using SPECT, 12-month-old WD-fed apoE-/- and WT mice were studied 4 hours after injecting [(99m)Tc]-AP39 (148 MBq). Subsequently, mice were sacrificed, thoracic aortas measured in a g-counter, and plaques analyzed using histology, immuno-histochemistry, autoradiography, and morphometry. RESULTS: In vivo [(99m)Tc]-AP39-SPECT imaging of apoE-/- mice demonstrated a significant signal activity in the plaque-ridden thoracic aorta (52.236 ± 40.646 cpm/cm³) that co-localized with the aortic arch and the supra-aortic arteries in MRI scans. Low signal activity (9.468 ± 4.976 cpm/cm³) was observed in WT mice. In apoE-/- mice, the strongest signals were detected in the aortic root, aortic arch and along the abdominal aorta. Autoradiography analysis of aortas from apoE-/- mice confirmed the in vivo observation by demonstrating signal localization in atherosclerotic plaques. The size of autoradiography-positive plaque areas correlated significantly with the size of ED-B-positive (r=0.645, P=0.044) or macrophage-infiltrated (r=0.84, P<0.002) plaques. A significant correlation was found between the sizes of ED-B-positive and macrophage-infiltrated plaque areas (r=0.93, P<0.01). CONCLUSION: [(99m)Tc]-AP39-SPECT in vivo imaging detects inflammatory plaque lesions in WD-fed apoE-/- mice.
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Anticuerpos Monoclonales/farmacocinética , Aterosclerosis/diagnóstico por imagen , Aterosclerosis/metabolismo , Fibronectinas/metabolismo , Aumento de la Imagen/métodos , Tomografía Computarizada de Emisión de Fotón Único/métodos , Animales , Enfermedades de la Aorta/diagnóstico por imagen , Enfermedades de la Aorta/metabolismo , Apolipoproteínas E/genética , Biomarcadores/sangre , Ratones , Ratones Noqueados , Imagen Molecular/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tecnecio/farmacocinéticaRESUMEN
The objective of this study was to synthesize and evaluate a novel fluorine-18 labeled deuterium substituted analogue of rasagiline (9, [(18)F]fluororasagiline-D2) as a potential PET radioligand for studies of monoamine oxidase B (MAO-B). The precursor compound (6) and reference standard (7) were synthesized in multi-step syntheses. Radiolabeling of 9 was accomplished by a two-step synthesis, compromising a nucleophilic substitution followed by hydrolysis of the sulfamidate group. The incorporation radiochemical yield from fluorine-18 fluoride was higher than 30%, the radiochemical purity was >99% and the specific radioactivity was >160GBq/µmol at the time of administration. In vitro compound 7 inhibited the MAO-B activity with an IC50 of 173.0±13.6nM. The MAO-A activity was inhibited with an IC50 of 9.9±1.1µM. The fluorine-18 version 9 was characterized in the cynomolgus monkey brain where a high brain uptake was found (275% SUV at 4min). There was a higher uptake in the striatum and thalamus compared to the cortex and cerebellum. A pronounced blocking effect (50% decrease) was observed in the specific brain regions after administration of l-deprenyl (0.5mg/kg) 30min prior to the administration of 9. Radiometabolite studies demonstrated 40% of unchanged radioligand at 90min post injection. An efficient radiolabeling of 9 was successfully established and in the monkey brain 9 binds to MAO-B rich regions and its binding is blocked by the selective MAO-B compound l-deprenyl. The radioligand 9 is a potential candidate for human PET studies.
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Indanos/química , Inhibidores de la Monoaminooxidasa/química , Monoaminooxidasa/química , Radiofármacos/química , Animales , Encéfalo/diagnóstico por imagen , Corteza Cerebral/metabolismo , Deuterio/química , Radioisótopos de Flúor/química , Humanos , Indanos/metabolismo , Macaca fascicularis/metabolismo , Monoaminooxidasa/metabolismo , Inhibidores de la Monoaminooxidasa/metabolismo , Tomografía de Emisión de Positrones , Unión Proteica , Radiofármacos/metabolismo , Tálamo/metabolismoRESUMEN
Trisomy 22 is a common trisomy in spontaneous abortions. In contrast, live-born trisomy 22 is rarely seen due to severe organ malformations associated with this condition. Here, we report on a male infant with complete, non-mosaic trisomy 22 born at 35 + 5 weeks via caesarean section. Peripheral blood lymphocytes and fibroblasts showed an additional chromosome 22 in all metaphases analyzed (47,XY,+22). In addition, array CGH confirmed complete trisomy 22. The patient's clinical features included dolichocephalus, hypertelorism, flattened nasal bridge, dysplastic ears with preauricular sinuses and tags, medial cleft palate, anal atresia, and coronary hypospadias with scrotum bipartitum. Essential treatment was implemented in close coordination with the parents. The child died 29 days after birth due to respiratory insufficiency and deterioration of renal function. Our patient's history complements other reports illustrating that children with complete trisomy 22 may survive until birth and beyond.
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The aim of this project was to synthesize and evaluate three novel fluorine-18 labeled derivatives of propargyl amine as potential PET radioligands to visualize monoamine oxidase B (MAO-B) activity. The three fluorinated derivatives of propargyl amine ((S)-1-fluoro-N,4-dimethyl-N-(prop-2-ynyl)-pent-4-en-2-amine (5), (S)-N-(1-fluoro-3-(furan-2-yl)propan-2-yl)-N-methylprop-2-yn-1-amine (10) and (S)-1-fluoro-N,4-dimethyl-N-(prop-2-ynyl)pentan-2-amine (15)) were synthesized in multi-step organic syntheses. IC(50) values for inhibition were determined for compounds 5, 10 and 15 in order to determine their specificity for binding to MAO-B. Compound 5 inhibited MAO-B with an IC(50) of 664 ± 48.08 nM. No further investigation was carried out with this compound. Compound 10 inhibited MAO-B with an IC(50) of 208.5 ± 13.44 nM and compound 15 featured an IC(50) of 131.5 ± 0.71 nM for its MAO-B inhibitory activity. None of the compounds inhibited MAO-A activity (IC(50) > 2 µM). The fluorine-18 labeled analogues of the two higher binding affinity compounds (10 and 15) (S)-N-(1-[(18)F]fluoro-3-(furan-2-yl)propan-2-yl)-N-methylprop-2-yn-1-amine (16) and (S)-1-[(18)F]fluoro-N,4-dimethyl-N-(prop-2-ynyl)pentan-2-amine (18) were both prepared from the corresponding precursors 9A, 9B and 14A, 14B by a one-step fluorine-18 nucleophilic substitution reaction. Autoradiography experiments on human postmortem brain tissue sections were performed with 16 and 18. Only compound 18 demonstrated a high selectivity for MAO-B over MAO-A and was, therefore, chosen for further examination by PET in a cynomolgus monkey. The initial uptake of 18 in the monkey brain was 250% SUV at 4 min post injection. The highest uptake of radioactivity was observed in the striatum and thalamus, regions with high MAO-B activity, whereas lower levels of radioactivity were detected in the cortex and cerebellum. The percentage of unchanged radioligand 18 was 30% in plasma at 90min post injection. In conclusion, compound 18 is a selective inhibitor of MAO-B in vitro and demonstrated a MAO-B specific binding pattern in vivo by PET in monkey. It can, therefore, be considered as a candidate for further investigation in human by PET.
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Encéfalo/diagnóstico por imagen , Encéfalo/enzimología , Radioisótopos de Flúor/análisis , Monoaminooxidasa/metabolismo , Pargilina/análogos & derivados , Propilaminas/análisis , Animales , Autorradiografía , Radioisótopos de Flúor/metabolismo , Radioisótopos de Flúor/farmacocinética , Humanos , Macaca fascicularis , Pargilina/análisis , Pargilina/metabolismo , Pargilina/farmacocinética , Tomografía de Emisión de Positrones , Propilaminas/metabolismo , Propilaminas/farmacocinética , RadiografíaRESUMEN
Mature T-cell lymphomas (MTCLs) have an extremely poor prognosis and are much less frequent than immature T-cell leukemias. This suggests that malignant outgrowth of mature T lymphocytes is well controlled. Indeed, in a previous study we found that mature T cells are resistant to transformation with known T-cell oncogenes. Here, however, we observed that T-cell receptor (TCR) mono-/oligoclonal mature T cells from TCR transgenic (tg) mice (OT-I, P14) expressing the oncogenes NPM/ALK or ΔTrkA readily developed MTCLs in T-cell-deficient recipients. Analysis of cell surface markers largely ruled out that TCR tg lymphomas were derived from T-cell precursors. Furthermore, cotransplanted non-modified TCR polyclonal T cells suppressed malignant outgrowth of oncogene expressing TCR tg T lymphocytes. A dominant role of an anti-leukemic immune response or Tregs in the control of MTCLs seems unlikely as naïve T cells derived from oncogene expressing stem cells, which should be tolerant to leukemic antigens, as well as purified CD4 and CD8 were resistant to transformation. However, our results are in line with a model in which homeostatic mechanisms that stabilize the diversity of the normal T-cell repertoire, for example, clonal competition, also control the outgrowth of potentially malignant T-cell clones. This study introduces a new innate mechanism of lymphoma control.
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Transformación Celular Neoplásica/genética , Células Madre Hematopoyéticas/inmunología , Linfoma de Células T/prevención & control , Células Precursoras de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/fisiología , Animales , Western Blotting , Diferenciación Celular , Femenino , Citometría de Flujo , Humanos , Linfoma de Células T/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Ratones Transgénicos , Fosfoproteínas/metabolismo , Receptores de Antígenos de Linfocitos T/clasificaciónRESUMEN
The aim of this study was to synthesize and evaluate a novel fluorine-18 labeled analogue of rasagiline (6) as a PET radioligand for monoamine oxidase B (MAO-B). The corresponding non-radioactive fluorine-19 ligand, (1S,2S)-2-fluoro-N-(prop-2-yn-1-yl)indan-1-amine (4), was characterized in in vitro assays. The precursor compound (3aS,8aR)-3-(prop-2-yn-1-yl)-3,3a,8,8a-tetrahydroindeno[1,2-d][1,2,3]oxathiazole 2,2-dioxide (3) and reference standard 4 were synthesized in multi-step syntheses. Recombinant human MAO-B and MAO-A enzyme preparations were used in order to determine IC(50) values for compound 4 by use of an enzymatic assay employing kynuramine as substrate. Radiolabeling was accomplished by a two-step synthesis, compromising a nucleophilic substitution followed by hydrolysis of the sulphamidate group. Human whole hemisphere autoradiography (ARG) was performed with [(18)F]fluororasagiline. Blocking experiments with pirlindole (MAO-A), L-deprenyl and rasagiline (MAO-B) were conducted to demonstrate the specificity of the binding. A positron emission tomography (PET) study was carried out in a cynomolgus monkey where time activity curves for whole brain and regions with high and low MAO-B activity were recorded. Radiometabolites were measured in monkey plasma using gradient HPLC. Compound 4 inhibited MAO-B with an IC(50) of 27 nM and MAO-A with an IC(50) of 2.3 µM. Radiolabeling of precursor 3 and subsequent hydrolysis of the protecting group towards (1S,2S)-2-[(18)F]fluoro-N-(prop-2-yn-1-yl)indan-1-amine (6) was successfully accomplished with an radiochemical yield of 40-70%, a radiochemical purity higher than 99% and a specific radioactivity higher than 200GBq/µmol. ARG demonstrated selective binding for [(18)F]fluororasagiline (6) to MAO-B containing brain regions, for example, striatum. The initial uptake in the monkey brain was 250% SUV at 4 min post injection. The highest amounts of radioactivity were observed in the striatum and thalamus as expected whereas in the cortex and cerebellum lower levels were observed. Metabolite studies demonstrated 30% unchanged radioligand at 90 min post injection. Our investigations demonstrated that the new ligand [(18)F]fluororasagiline (6) binds specifically to MAO-B in vitro and has a MAO-B specific binding pattern in vivo. Thus, it could serve as a novel potential candidate for human PET studies.
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Indanos/química , Ligandos , Monoaminooxidasa/química , Radiofármacos/síntesis química , Animales , Encéfalo/diagnóstico por imagen , Radioisótopos de Flúor/química , Humanos , Indanos/metabolismo , Macaca fascicularis , Monoaminooxidasa/genética , Monoaminooxidasa/metabolismo , Tomografía de Emisión de Positrones , Radiofármacos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMEN
Objective: To investigate the functional adaptive process of the fetal autonomic nervous system during hypnosis from the 20th week of gestation till term. Are there changes in the power spectrum analysis of fetal heart rate when the mother is having a clinical hypnosis or control period? Study Design: Fourty-nine FHR recordings were analysed. Included recordings were from singletons and abdominal fetal ECG-monitored pregnancies. All women were randomised to receive clinical hypnosis followed by a period with no intervention or vice versa. Statistical analyses were performed with the Wilcoxon signed ranks and Spearman rho correlation tests. Results: There was a significant difference found between fetal heart rate at baseline (144.3 ± 6.0) and hypnosis (142.1 ± 6.4). A difference was also detected between the standard deviation of the heart rate between baseline (6.7 ± 1.9) and hypnosis (6.8 ± 3.5). LFnu was smaller during baseline (80.2 ± 5.3) than during hypnosis (82.1 ± 5.7), whereas HFnu was significantly larger (19.8 ± 5.3 vs. 17.9 ± 5.7). There was no correlation between the gestation age and the change in LFnu, HFnu or ratio LF/HF due to the hypnosis intervention. Conclusion: The functional adaptive process of the fetal autonomic system during hypnosis is reflected by a sympathovagal shift towards increased sympathetic modulation.
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PURPOSE: The aim of this study was to determine the quality of intrapartum uterine activity (UA) monitoring in daily practice during the first and second stages of labour. The total duration of inadequate UA monitoring is quantified in relation to the technique applied, namely, external tocodynamometry (TOCO) or electrohysterography (EHG). MATERIAL AND METHODS: 144 UA recordings, collected from 1st September 2008 until 15th October 2009 from deliveries at the Marien-Hospital Witten, Germany, were analysed by obstetricians based at different centres. The included recordings were from singleton and simultaneously with external TOCO and EHG monitored pregnancies. External TOCO and EHG UA recordings were blinded. RESULTS: The percentages of "adequate" UA recordings in the first and second stages of labour were much higher for the external EHG than the external TOCO mode (p<0.001). All doctors evaluated the UA assessment as "easier" (p <0.001) using the EHG compared with TOCO. CONCLUSION: Intrapartum UA monitoring in -daily practice via the EHG mode provides a more recognisable UA trace than the TOCO.
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Procesamiento de Señales Asistido por Computador/instrumentación , Monitoreo Uterino/instrumentación , Algoritmos , Cardiotocografía/instrumentación , Diseño de Equipo , Femenino , Humanos , Recién Nacido , Primer Periodo del Trabajo de Parto , Segundo Periodo del Trabajo de Parto , Valor Predictivo de las Pruebas , Embarazo , Programas Informáticos , Ultrasonografía Doppler , Ultrasonografía PrenatalRESUMEN
The main objective of this study was to generate a fast analytical method to determine the five phthalates benzylbutylphthalate (BBP), dibutylphthalate (DBP), di-(2-ethylhexyl)-phthalate (DEHP), di-isodecylphthalate (DIDP), and di-isononylphthalate (DINP) in house dust. To achieve this liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS/MS) was used for measurement. The risk of lab- and cross-contamination was nearly eliminated completely as a very short and fast sample preparation including a sieving step and an ultrasonic extraction for the analytes from the dust samples was used. Quantification through internal standard calibration resulted in low limits of determination (DEHP 4 mg kg(-1) to DBP 14 mg kg(-1)). A potential interaction between the analytes DIDP and DINP during chromatographic measurement could be excluded while performing a two level factorial design. Furthermore it was examined to what extend carpet and plastic materials respectively have influence on the total amount of phthalates in dust. It could be shown that apartments in which a minimum of both of these sources appeared revealed the lowest total amount of sum of phthalates in dust (median 362 mg kg(-1)).
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Contaminación del Aire Interior/análisis , Cromatografía Liquida/métodos , Polvo/análisis , Ácidos Ftálicos/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Vivienda , Plastificantes/análisis , Espectrometría de Masas en Tándem/métodosRESUMEN
OBJECTIVE: Secondary hyperparathyroidism in hemodialysis patients requires optimal correction of vitamin D deficiency with active vitamin D and analogues. It has been postulated that new vitamin D analogues, i.e. paricalcitol, efficiently suppress parathyroid hormone serum levels (PTH), but do not increase intestinal calcium absorption as much as calcitriol. The effects of calcitriol and paricalcitol on calcium balance can best be characterized under standardized conditions in healthy individuals with normal renal function, because the urinary calcium excretion at steady state corresponds to the net calcium absorption in the gut. METHODS: In a randomized, double-blind, placebo-controlled, 3-way crossover Phase I study in 13 healthy individuals we investigated the changes compared to placebo in PTH and urinary calcium excretion during 6-day treatment periods with paricalcitol (1.5 microg/day) and calcitriol (0.5 microg/day). RESULTS: 24-hour urinary calcium excretion was stable during 6 days of placebo administration. Neither paricalcitol nor calcitriol significantly changed calcium excretion. Urinary creatinine, magnesium and phosphate excretion also remained unchanged over the study periods irrespective of the treatment. However, calcitriol was shown to be effective in reducing iPTH levels during 6 days of treatment (mean reduction 4.03+/-0.69 pmol/l), whereas paricalcitol had no effect. CONCLUSION: Using a dosing ratio of 1:3 for calcitriol:paricalcitol, i.e. the same conversion factor used previously in studies on hemodialysis patients, only calcitriol was able to reduce iPTH levels in healthy individuals. Low-dose calcitriol reduced iPTH levels without raising calcium absorption and without including any hypercalcemia.
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Calcitriol/farmacología , Calcio/orina , Ergocalciferoles/farmacología , Hormona Paratiroidea/sangre , Vitaminas/farmacología , Adolescente , Adulto , Creatinina/orina , Método Doble Ciego , Femenino , Humanos , Magnesio/orina , Masculino , Persona de Mediana Edad , Fosfatos/orinaRESUMEN
BACKGROUND: House dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae cause allergic disease in humans as well as in dogs. In geographical regions where the two mite species coexist, they both elicit specific immunoglobulin (Ig E) responses in humans whereas dogs preferentially react to D. farinae extracts. In dogs the main IgE binding is directed to the D. farinae chitinase allergens Der f 15 and Der f 18 and not to the groups 1 and 2 allergens as found for humans. Although the IgE response of humans to Der f 18 has been investigated there is no report on Der f 15-specific IgE in humans. OBJECTIVE: This study aimed to characterize the chitinase allergens Der p 15 and Der p 18 of D. pteronyssinus and to find out whether they are important allergens for humans. METHODS: cDNA was cloned by a polymerase chain reaction strategy from D. pteronyssinus libraries using primers based on conserved chitinase sequences. IgE binding to the recombinant polypeptides was measured by immunosorbent assay. Mice were immunized with the polypeptides and cross-reactivity examined. RESULTS: Two variants of Der p 15 were isolated, encoding mature proteins of 58.8 and 61.4 kDa. The amino acid sequences had 90% identity to Der f 15. The cDNA for Der p 18 encoded a mature protein of 49.2 kDa with 88% sequence identity to Der f 18. Der p 15-specific IgE was detected in 70% and Der p 18-specific IgE in 63% of a panel of 27 human allergic sera. CONCLUSIONS: The D. pteronyssinus chitinases Der p 15 and Der p 18 show a high frequency of binding to IgE in allergic human sera. They are therefore potentially important allergens for humans as well as dogs.
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Antígenos Dermatofagoides/genética , Quitinasas/inmunología , Dermatophagoides pteronyssinus/inmunología , Hipersensibilidad/inmunología , Secuencia de Aminoácidos , Animales , Antígenos Dermatofagoides/inmunología , Proteínas de Artrópodos , Secuencia de Bases , Estudios de Casos y Controles , Clonación Molecular , Reacciones Cruzadas , ADN Complementario/análisis , Biblioteca de Genes , Humanos , Inmunoglobulina E/inmunología , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
226Ra is one of the key nuclides among the natural radionuclides from the point of view of radiation protection. For monitoring the radiation exposure risk along the water pathway it has to be measured routinely with low detection limits. Because of the properties of 226Ra and its progenies, a number of quite different methods are possible for this purpose. This paper presents a comparison of routine techniques for the determination of 226Ra in water samples as applied by the authors.
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Radiometría/métodos , Radón/análisis , Contaminantes Radiactivos del Agua/análisis , Humanos , Radioquímica , Hijas del Radón/análisis , Conteo por Cintilación , Espectrometría gamma , Tecnología Radiológica , Abastecimiento de AguaRESUMEN
PURPOSE: Although cortical contrast adaptation has been extensively studied with both psychophysical and electrophysiological techniques, little is known about retinal contrast adaptation in humans. METHODS: Retinal and cortical long-term contrast adaptation was assessed with simultaneous measurement of pattern electroretinogram (PERG) and cortical visual evoked potentials (VEPs). This study involved three approaches: sampling of the contrast transfer function from 2.7% to 98% with adaptation to high (98%) and low (7.3%) contrasts, linearity of adaptation effects, and transfer of contrast adaptation between parallel and orthogonal grating orientations. RESULTS: Contrast adaptation affected retinal and cortical recordings quite differently. The VEP showed a sigmoid contrast transfer function, which was shifted toward higher contrasts (by a factor of 1.9), whereas amplitudes at higher test contrasts were enhanced to 127%. The PERG decreased in amplitude to approximately 90%, and the latency was significantly reduced by 4 to 6 msec (P < 0.05). All measured effects were linear with adaptation contrast. Orientation played no role in the PERG results, whereas the VEP was enhanced to 125% when tested parallel and to 150% when tested orthogonal to adaptation. CONCLUSIONS: VEP results confirm and extend previous findings and fit well with single-cell recordings. The PERG findings suggest that retinal contrast adaptation occurs and mainly operates in the temporal domain, comparable to rapid gain-control findings in cats and primates.
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Adaptación Ocular/fisiología , Sensibilidad de Contraste/fisiología , Retina/fisiología , Corteza Visual/fisiología , Electrorretinografía , Potenciales Evocados Visuales , Humanos , Reconocimiento Visual de ModelosRESUMEN
This paper provides information about the research programme "In-plant interventions in the German car industry to increase job opportunities for employees with (severe) disabilities". The research was done in 2000 by the University of Trier and the International Research Unit for Work and Social Integration (IFASI). The purpose of the study was to capture, document, and analyse internal practices of occupational rehabilitation in five German car factories. Taking a qualitative approach, 23 persons of different company areas were interviewed, and numerous documents were analysed. The article reflects applied disability management strategies and points out success factors and barriers of inclusion.
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Personas con Discapacidad/rehabilitación , Industrias , Servicios de Salud del Trabajador/organización & administración , Rehabilitación Vocacional , Desarrollo de Personal/métodos , Adulto , Automóviles , Personas con Discapacidad/legislación & jurisprudencia , Empleos Subvencionados , Femenino , Alemania , Humanos , Industrias/legislación & jurisprudencia , Industrias/organización & administración , Masculino , Política Organizacional , Encuestas y Cuestionarios , Recursos HumanosRESUMEN
The photophysical and photochemical properties of N-phthaloyl-methionine (1), S-methyl-N-phthaloyl-cysteine methyl ester (2) and N-phthaloyltranexamic acid (3) were studied by time-resolved UV/Vis spectroscopy, using laser pulses at 248 or 308 nm. The quantum yield of fluorescence is low (phi(f)< 10(-2)) for 1-3 in fluid and glassy media, whereas that of phosphorescence is large (0.3-0.5) in ethanol at - 196 degrees C. The triplet properties were examined in several solvents, at room temperature and below. The spectra and decay kinetics are similar, but the population of the pi(pi*) triplet state, as measured by T-T absorption, is much lower for 1 and 2 than for 3 or N-methyltrimellitimide (5') at ambient temperatures. The quantum yield (phi(delta)) of singlet molecular oxygen O2(1deltag) formation is substantial for 3 and 5' in several air- or oxygen-saturated solvents at room temperature, but small for 2 and 1. The quantum yield of decomposition is substantial (0.2-0.5) for 3 and small (<0.05) for 2 and 1. It is postulated that photoinduced charge separation in the spectroscopically undetectable 3n,pi* state may account for the cyclization products of 1 and 2. In aqueous solution, this also applies for 3, whereas in organic solvents cyclization involves mainly the lower lying 3pi,(pi*) state. Triplet acetone, acetophenone and xanthone are quenched by 1-3 in acetonitrile; the rate constant is close to the diffusion-controlled limit, but smaller for benzophenone. While the energy transfer from the triplet ketone occurs for 3, a major contribution of electron transfer to the N-phthalimide derivative is suggested for 1 and 2, where the radical anion of benzophenone or 4-carboxybenzophenone is observed in alkaline aqueous solution.
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OBJECTIVE: To review the benefits, challenges, and procedural decisions to consider when implementing and managing a treatment outcome program for a maltreated population. METHOD: We reviewed the reasons to implement a treatment outcome program, decisions regarding procedures, and challenges likely to be encountered based on literature in the field and the authors' 6 years of experience in developing and maintaining an outcome program at a center specializing in the treatment of maltreated children. RESULTS: The development of an outcome programs requires careful measurement selection, early and ongoing staff-involvement, support from higher management, a well-developed data base and client tracking system, a coordinator and support staff, clinical utility, planning for fiscal impact, and flexibility to contend with challenges. CONCLUSIONS: Based on our experience, the plethora of clinically rich and administratively useful information derived from an outcome program far outweighs the challenges and costs of establishing and maintaining an outcome program.