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1.
BMC Pediatr ; 23(1): 111, 2023 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-36890472

RESUMO

BACKGROUND: Blueberry muffin is a descriptive term for a neonate with multiple purpuric skin lesions. Many causes are known, amongst them life-threatening diseases like congenital infections or leukemia. Indeterminate cell histiocytosis (ICH) is an exceptionally rare cause of blueberry muffin rash. ICH is a histiocytic disorder which can be limited to the skin or can present with systemic involvement. A mutation that has been described in histiocytic disorders is a MAP2K1 mutation. In ICH, this mutation has previously been described in merely one case. CASE PRESENTATION: A term male neonate was admitted to the neonatology ward directly after birth because of a blueberry muffin rash. ICH was diagnosed on skin biopsy. The lesions resolved spontaneously. The patient is currently 3 years old and has had no cutaneous lesions or systemic involvement so far. This disease course is similar to that of the Hashimoto-Pritzker variant of LCH. CONCLUSIONS: ICH can manifest in neonates as resolving skin lesions. It is limited to the skin in most cases, but systemic development is possible. Therefore, it is essential to confirm the diagnosis with a biopsy before the lesions resolve and to monitor these patients closely with routine follow-up.


Assuntos
Exantema , Histiocitose de Células de Langerhans , Púrpura , Dermatopatias , Recém-Nascido , Lactente , Feminino , Humanos , Masculino , Pré-Escolar , Histiocitose de Células de Langerhans/complicações , Histiocitose de Células de Langerhans/diagnóstico , Histiocitose de Células de Langerhans/congênito , Dermatopatias/complicações , Dermatopatias/congênito , Dermatopatias/patologia , Pele , Exantema/etiologia
2.
J Eur Acad Dermatol Venereol ; 34(6): 1309-1318, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31919904

RESUMO

BACKGROUND: It has been proposed that two main phenotypes of hidradenitis suppurativa (HS) exist. This proposal is based upon different elementary structures detected in the skin, namely follicular subtypes and inflammatory subtypes. Having an accurate definition of these two variants could help us to better identify patients who may require an early intervention with currently approved targeted immunomodulatory therapies. OBJECTIVE: To define and distinguish between the epidemiological, clinical and analytic characteristics of these two HS phenotypes. METHODS: An observational, descriptive, non-randomized and prospective study was conducted. Patients diagnosed with HS between May 2012 and April 2017 by a specialized unit were included. Ultrasound evaluation was performed in all cases. RESULTS: About 197 patients were included, 100 women and 97 men, aged between 25 and 47 years. The mean age of onset was significantly different between phenotypes, ranging between 26.69 ± 9.05 in the inflammatory subtype and 17.62 ± 6.42 in the follicular subtype. Follicular subtype patients exhibited a significantly higher number of nodules combined with the presence of multiple commedons (5.65 ± 3.38 versus 0.89 ± 2.72). This contrasted with the higher count of abscesses and fistulas detected in the inflammatory subtype (respectively, 4 ± 2.74 and 3.11 ± 2.56 versus 0.56 ± 1.02 and 0.26 ± 0.56). IgA levels were significantly higher in the inflammatory subtype (497.71 ± 262.26 versus 232.38 ± 84.06). Mean IHS4 score evaluation was higher in the inflammatory subtype (21.04 ± 11.9) compared with the follicular phenotype (7.54 ± 4.66). The inflammatory subtype was found to be an independent risk factor for disease aggressiveness in the multivariate analysis (OR 0.034 [95% CI 0.015-0.072]). LIMITATIONS: Small sample size. CONCLUSION: Preliminary data suggest the existence of an inflammatory HS phenotype that is associated with higher aggressiveness and major risk of progression during natural history of the disease.


Assuntos
Hidradenite Supurativa , Abscesso , Adulto , Feminino , Hidradenite Supurativa/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Prospectivos , Índice de Gravidade de Doença
3.
J Cell Sci ; 127(Pt 11): 2518-27, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24652834

RESUMO

The olfactory signal transduction cascade transforms odor information into electrical signals by a cAMP-based amplification mechanism. The mechanisms underlying the very precise temporal and spatial organization of the relevant signaling components remains poorly understood. Here, we identify, using co-immunoprecipitation experiments, a macromolecular assembly of signal transduction components in mouse olfactory neurons, organized through MUPP1. Disruption of the PDZ signaling complex, through use of an inhibitory peptide, strongly impaired odor responses and changed the activation kinetics of olfactory sensory neurons. In addition, our experiments demonstrate that termination of the response is dependent on PDZ-based scaffolding. These findings provide new insights into the functional organization, and regulation, of olfactory signal transduction.


Assuntos
Proteínas de Transporte/metabolismo , Complexos Multiproteicos/metabolismo , Mucosa Olfatória/fisiologia , Animais , Proteínas de Transporte/genética , AMP Cíclico/metabolismo , Células HEK293 , Humanos , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/metabolismo , Neurônios Receptores Olfatórios/metabolismo , Domínios PDZ/genética , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Receptores Odorantes/metabolismo , Transdução de Sinais
4.
Phys Rev Lett ; 115(25): 256104, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26722930

RESUMO

Mn has been found to self-assemble into atomic chains running perpendicular to the surface dimer reconstruction on Si(001). They differ from other atomic chains by a striking asymmetric appearance in filled state scanning tunneling microscopy (STM) images. This has prompted complicated structural models involving up to three Mn atoms per chain unit. Combining STM, atomic force microscopy, and density functional theory we find that a simple necklacelike chain of single Mn atoms reproduces all their prominent features, including their asymmetry not captured by current models. The upshot is a remarkably simpler structure for modeling the electronic and magnetic properties of Mn atom chains on Si(001).

5.
Acta Anaesthesiol Scand ; 57(6): 767-75, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23421557

RESUMO

BACKGROUND: Segmental dose reduction with increasing age after thoracic epidural anaesthesia (TEA) has been documented. We hypothesised that after a fixed loading dose of ropivacaine at the T3-T4 level, increasing age would result in more extended analgesic spread. In addition, other aspects of neural blockade and haemodynamic changes were studied. METHODS: Thirty-five lung surgery patients were included in three age groups. Thirty-one patients received an epidural catheter at the T3-T4 interspace followed by an injection of 8-ml ropivacaine 0.75%. Analgesia was assessed with pinprick and temperature discrimination. Motor block was tested using the Bromage and epidural scoring scale for arm movements score. An arterial line was inserted for invasive measurement of blood pressure, cardiac index (CI) and stroke volume (SV). RESULTS: There was no influence of age on quality of TEA except for the caudal border of analgesia being somewhat lower in the middle and older age group compared with the young age group. Heart rate (6.0 ± 5.9, P < 0.001), mean arterial pressure (16.1 ± 15.6, P < 0.001), CI (0.55 ± 0.49, P < 0.001) and SV (9.6 ± 14.6, P = 0.001) decreased after TEA for the total group. Maximal reduction in heart rate after TEA was more extensive in the young age group compared with the other age groups. There was no effect of age on other cardiovascular parameters. CONCLUSION: We were unable to demonstrate an effect of age on the maximal number of spinal segments blocked after TEA; however, the caudad spread of analgesia increased with advancing age. In addition, reduction of heart rate was greater in the youngest group.


Assuntos
Envelhecimento/fisiologia , Amidas/farmacocinética , Anestesia Epidural/métodos , Anestésicos Locais/farmacocinética , Frequência Cardíaca/efeitos dos fármacos , Bloqueio Nervoso , Condução Nervosa/efeitos dos fármacos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Amidas/administração & dosagem , Amidas/farmacologia , Anestésicos Locais/administração & dosagem , Anestésicos Locais/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Difusão , Humanos , Pessoa de Meia-Idade , Pleurodese , Ropivacaina , Volume Sistólico/efeitos dos fármacos , Cirurgia Torácica Vídeoassistida , Vértebras Torácicas , Toracotomia , Distribuição Tecidual , Adulto Jovem
6.
Water Sci Technol ; 65(9): 1648-53, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22508128

RESUMO

Membrane bioreactor (MBR) technology is a very reliable and extensively tested solution for biological wastewater treatment. Nowadays, separate treatment of highly polluted wastewater streams especially from hospitals and other health care facilities is currently under investigation worldwide. In this context, the MBR technology will play a decisive role because an effluent widely cleaned up from solids and nutrients is absolutely mandatory for a subsequent further elimination of organic trace pollutants. Taking hospital wastewater as an example, the aim of this study was to investigate to what extent MBR technology is an adequate 'pre-treatment' solution for further elimination of trace pollutants. Therefore, we investigated - within a 2-year period - the performance of a full-scale hospital wastewater treatment plant (WWTP) equipped with a MBR by referring to conventional chemical and microbiological standard parameters. Furthermore, we measured the energy consumption and tested different operating conditions. According to our findings the MBR treatment of the hospital wastewater was highly efficient in terms of the removal of solids and nutrients. Finally, we did not observe any major adverse effects on the operation and performance of the MBR system which potentially could derive from the composition of the hospital wastewater. In total, the present study proved that MBR technology is a very efficient and reliable treatment approach for the treatment of highly polluted wastewater from hospitals and can be recommended as a suitable pre-treatment solution for further trace pollutant removal.


Assuntos
Reatores Biológicos , Filtração/instrumentação , Hospitais , Eliminação de Resíduos de Serviços de Saúde/métodos , Eliminação de Resíduos Líquidos/métodos , Alemanha , Esgotos , Poluentes da Água , Poluição da Água/prevenção & controle , Purificação da Água/métodos
7.
Biophys Rev (Melville) ; 3(3): 031304, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38505277

RESUMO

Different types of biological cells respond differently to mechanical stresses, and these responses are mainly governed by the cytoskeleton. The main components of this biopolymer network are actin filaments, microtubules, and intermediate filaments, whose mechanical and dynamic properties are highly distinct, thus opening up a large mechanical parameter space. Aside from experiments on whole, living cells, "bottom-up" approaches, utilizing purified, reconstituted protein systems, tremendously help to shed light on the complex mechanics of cytoskeletal networks. Such experiments are relevant in at least three aspects: (i) from a fundamental point of view, cytoskeletal networks provide a perfect model system for polymer physics; (ii) in materials science and "synthetic cell" approaches, one goal is to fully understand properties of cellular materials and reconstitute them in synthetic systems; (iii) many diseases are associated with cell mechanics, so a thorough understanding of the underlying phenomena may help solving pressing biomedical questions. In this review, we discuss the work on networks consisting of one, two, or all three types of filaments, entangled or cross-linked, and consider active elements such as molecular motors and dynamically growing filaments. Interestingly, tuning the interactions among the different filament types results in emergent network properties. We discuss current experimental challenges, such as the comparability of different studies, and recent methodological advances concerning the quantification of attractive forces between filaments and their influence on network mechanics.

8.
Water Sci Technol ; 63(1): 66-71, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21245555

RESUMO

Membrane Bioreactors (MBR) are a very attractive option for the treatment of hospital wastewater and elimination of pharmaceuticals in high density urban areas. The present investigation showed that, depending on the substance, between 19% and 94% of the level of antibiotics found in the environment originate from hospitals. Because of their ecotoxic potential, hospital wastewaters can have a significant impact on the environment. The segregation of these wastewaters and their separate treatment at the source can reduce the entry of drugs in waterways and enable water reuse after adequate polishing treatment processes.


Assuntos
Reatores Biológicos , Hospitais , Resíduos Industriais , Membranas Artificiais , Urbanização , Poluentes Químicos da Água/isolamento & purificação
9.
Thromb Res ; 199: 143-148, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33535120

RESUMO

INTRODUCTION: In the first wave, thrombotic complications were common in COVID-19 patients. It is unknown whether state-of-the-art treatment has resulted in less thrombotic complications in the second wave. METHODS: We assessed the incidence of thrombotic complications and overall mortality in COVID-19 patients admitted to eight Dutch hospitals between September 1st and November 30th 2020. Follow-up ended at discharge, transfer to another hospital, when they died, or on November 30th 2020, whichever came first. Cumulative incidences were estimated, adjusted for competing risk of death. These were compared to those observed in 579 patients admitted in the first wave, between February 24th and April 26th 2020, by means of Cox regression techniques adjusted for age, sex and weight. RESULTS: In total 947 patients with COVID-19 were included in this analysis, of whom 358 patients were admitted to the ICU; 144 patients died (15%). The adjusted cumulative incidence of all thrombotic complications after 10, 20 and 30 days was 12% (95% confidence interval (CI) 9.8-15%), 16% (13-19%) and 21% (17-25%), respectively. Patient characteristics between the first and second wave were comparable. The adjusted hazard ratio (HR) for overall mortality in the second wave versus the first wave was 0.53 (95%CI 0.41-0.70). The adjusted HR for any thrombotic complication in the second versus the first wave was 0.89 (95%CI 0.65-1.2). CONCLUSIONS: Mortality was reduced by 47% in the second wave, but the thrombotic complication rate remained high, and comparable to the first wave. Careful attention to provision of adequate thromboprophylaxis is invariably warranted.


Assuntos
COVID-19/complicações , Embolia Pulmonar/etiologia , Trombose/etiologia , Tromboembolia Venosa/etiologia , Idoso , Idoso de 80 Anos ou mais , COVID-19/mortalidade , Estudos de Coortes , Estado Terminal/mortalidade , Feminino , Hospitalização , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Modelos de Riscos Proporcionais , SARS-CoV-2/isolamento & purificação
10.
Water Sci Technol ; 61(7): 1691-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20371926

RESUMO

Considerable concern exists regarding the appearance and effects of trace and ultra trace pollutants in the aquatic environment. In this context, it is necessary to identify relevant hot spot wastewater - such as hospital wastewater - and to implement specific wastewater treatment solutions. Membrane bioreactor (MBR) technology seems to be a suitable pre-treatment approach for the subsequent advanced treatment by high pressure membrane systems such as nanofiltration (NF) and reverse osmosis (RO). This paper is based upon investigations on the first full scale MBR for separate treatment of hospital wastewater in Germany. In this study an NF as well as an RO module for further treatment of the MBR filtrate were tested. The removal efficiencies were assessed using the following target compounds: bezafibrate, bisoprolol, carbamazepine, clarithromycin, ciprofloxacin, diclofenac, ibuprofen, metronidazole, moxifloxacin, telmisartan and tramadol. In summary, the results of this study confirmed that MBR technology followed by an advanced treatment for trace pollutant removal is an adequate approach for specific treatment of hot spot wastewater such as hospital wastewater. In particular, it was shown that - comparing the tested NF and RO - only (a two stage) RO is appropriate to remove pharmaceutical residues from hospital wastewater entirely. The recommended yield of the 2-stage RO is 70% which results in a retentate sidestream of 9%. Our investigations proved that RO is a very efficient treatment approach for elimination of trace pollutants.


Assuntos
Filtração/instrumentação , Hospitais , Eliminação de Resíduos de Serviços de Saúde/métodos , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Eliminação de Resíduos Líquidos/métodos , Filtração/métodos , Osmose , Projetos Piloto , Poluentes da Água , Poluição da Água/prevenção & controle , Purificação da Água/métodos
11.
Lab Chip ; 9(13): 1914-25, 2009 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-19532967

RESUMO

A new microfluidic approach for charge-based particle separation using combined hydrodynamic and electrokinetic effects is presented. A recirculating flow pattern is employed, generated through application of bi-directional flow in a narrow glass microchannel incorporating diverging or converging segments at both ends. The bi-directional flow in turn is a result of opposing pressure-driven flow and electro-osmotic flow in the device. Trapping and preconcentration of charged particles is observed in the recirculating flow, under conditions where the average net velocity of the particles themselves approaches zero. This phenomenon is termed flow-induced electrokinetic trapping (FIET). Importantly, the electrophoretic mobility (zeta potential) of the particles determines the flow conditions required for trapping. In this paper, we exploit FIET for the first time to perform particle separations. Using a non-uniform channel, one type of particle can be trapped according to its zeta-potential, while particles with higher or lower zeta-potentials are flushed away with the pressure-driven or electro-osmotic components, respectively, of the flow. This was demonstrated using simple mixtures of two polystyrene bead types having approximately the same size (3 microm) but different zeta potentials (differences were in the order of 25 to 40 mV). To gain more insight into the separation mechanism, particle separations in straight, 3 cm-long microchannels with uniform cross-section were also studied under conditions of bi-directional flow without trapping. A thorough theoretical analysis confirmed that trapping occurs when electrokinetic and pressure-driven particle velocities are equal and opposite throughout the diverging segment. This makes it possible to predict the pressure and electric field conditions required to separate particles having defined zeta potentials.


Assuntos
Eletroforese em Microchip/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Microesferas , Eletricidade Estática , Eletroforese em Microchip/métodos , Desenho de Equipamento , Tamanho da Partícula , Poliestirenos/química , Propriedades de Superfície
12.
Bioconjug Chem ; 20(8): 1578-86, 2009 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-19586015

RESUMO

The scope of the Cu(I)-catalyzed [2 + 3] azide/alkyne cycloaddition (CuAAC, click chemistry) as a key reaction for the conjugation of ferrocene derivatives to N-terminal functionalized PNA oligomers is explored herein (PNA: peptide nucleic acid). The facile solid-phase synthesis of N-terminal azide or alkyne-functionalized PNA oligomer precursors and their cycloaddition with azidoferrocene, ethynylferrocene, and N-(3-ethylpent-1-yn-3-yl)ferrocene-carboxamide (DEPA-ferrocene) on the solid phase are presented. While the click reaction with azidomethylferrocene worked equally well, the ferrocenylmethyl group is lost from the conjugate upon acid cleavage. However, the desired product was obtained via a post-SPPS conversion of the alkyne-PNA oligomer with azidomethylferrocene in solution. The synthesis of all ferrocene-PNA conjugates (trimer t(3)-PNA, 3, 4, 5, 6; 12mer PNA, 10 - t c t a c a a g a c t c, 11 - t c t a c c g t a c t c) succeeded with excellent yields and purities, as determined by mass spectrometry and HPLC. Electrochemical studies of the trimer Fc-PNA conjugates 3, 4, 5, and 6 with four different ferrocene moieties revealed quasi-reversible redox processes of the ferrocenyl redox couple Fc(0/+) and electrochemical half-wave potentials in a range of E(1/2) = -20 mV to +270 mV vs FcH(0/+) (Fc: ferrocenyl, C(10)H(9)Fe). The observed potential differences ΔE(1/2)(min) are always greater than 60 mV for any given pair of Fc-PNA conjugates, thus allowing a reliable differentiation with sensitive electrochemical methods like e.g. square wave voltammetry (SWV). This is the electrochemical equivalent of "four-color" detection and is hence denoted "four-potential" labeling. Preparation and electrochemical investigation of the set of four structurally different and electrochemically distinguishable ferrocenyl groups conjugated to PNA oligomers, as exemplified by the conjugates 3, 4, 5, and 6, demonstrates the scope of the azide/alkyne cycloaddition for the labeling of PNA with electrochemically active ferrocenyl groups. Furthermore, it provides a PNA-based system for the electrochemical detection of single-nucleotide polymorphism (SNP) in DNA/RNA.


Assuntos
Química Click/métodos , Compostos Ferrosos/química , Ácidos Nucleicos Peptídicos/química , Coloração e Rotulagem/métodos , Catálise , Cobre/química , Ciclização , Eletroquímica , Metalocenos , Estrutura Molecular , Estereoisomerismo
13.
Lab Chip ; 8(10): 1632-9, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18813384

RESUMO

Drops of water-in-fluorocarbon emulsions have great potential for compartmentalizing both in vitro and in vivo biological systems; however, surfactants to stabilize such emulsions are scarce. Here we present a novel class of fluorosurfactants that we synthesize by coupling oligomeric perfluorinated polyethers (PFPE) with polyethyleneglycol (PEG). We demonstrate that these block copolymer surfactants stabilize water-in-fluorocarbon oil emulsions during all necessary steps of a drop-based experiment including drop formation, incubation, and reinjection into a second microfluidic device. Furthermore, we show that aqueous drops stabilized with these surfactants can be used for in vitro translation (IVT), as well as encapsulation and incubation of single cells. The compatability of this emulsion system with both biological systems and polydimethylsiloxane (PDMS) microfluidic devices makes these surfactants ideal for a broad range of high-throughput, drop-based applications.


Assuntos
Materiais Biocompatíveis , Emulsões , Fluorocarbonos/química , Tensoativos/química , Água/química , Polietilenoglicóis/química
14.
Nat Commun ; 9(1): 3641, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30194418

RESUMO

We present a correlative microscopy approach for biology based on holographic X-ray imaging, X-ray scanning diffraction, and stimulated emission depletion (STED) microscopy. All modalities are combined into the same synchrotron endstation. In this way, labeled and unlabeled structures in cells are visualized in a complementary manner. We map out the fluorescently labeled actin cytoskeleton in heart tissue cells and superimpose the data with phase maps from X-ray holography. Furthermore, an array of local far-field diffraction patterns is recorded in the regime of small-angle X-ray scattering (scanning SAXS), which can be interpreted in terms of biomolecular shape and spatial correlations of all contributing scattering constituents. We find that principal directions of anisotropic diffraction patterns coincide to a certain degree with the actin fiber directions and that actin stands out in the phase maps from holographic recordings. In situ STED recordings are proposed to formulate models for diffraction data based on co-localization constraints.


Assuntos
Holografia/métodos , Microscopia/métodos , Radiografia/métodos , Citoesqueleto de Actina , Animais , Animais Recém-Nascidos , Corantes Fluorescentes , Miócitos Cardíacos , Ratos Wistar
15.
Hum Immunol ; 26(1): 47-58, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2476425

RESUMO

Recent investigations have shown that alloreactive T cells are capable of responding to structures defined by specific linear amino acid sequences on class II molecules. In the present study we show that also a polymorphism can be recognized that is not defined by such linear amino acid sequences. Two human T-cell clones, sensitized to DRw13 haplotypes, are described. The description of clone c50 serves to exemplify the first model. This DRB1-specific clone responds to stimulator cells that carry DR molecules, different in their DRB1 first and second hypervariable regions (HV1 and HV2) but identical in their HV3 regions (i.e., DRw13,Dw18; DRw13,Dw19; DR4,Dw10; and DRw11,LDVII). The second clone, c1443, behaves nonconventionally. It responds to DRw13,Dw18; DRw13,Dw19; and DR4,Dw4 stimulator cells, although no specific amino acid sequence is shared between these specificities. The latter pattern of reactivity suggests the existence of a novel polymorphism recognized by alloreactive T cells. This particular polymorphism may also be biologically significant.


Assuntos
Antígenos HLA-DR/imunologia , Linfócitos T/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais , Células Clonais , Epitopos/imunologia , Antígenos HLA-DR/genética , Humanos , Ativação Linfocitária , Dados de Sequência Molecular , Polimorfismo Genético , Receptores de Antígenos de Linfócitos T/análise
16.
J Cancer Res Clin Oncol ; 126(1): 53-6, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10641750

RESUMO

PURPOSE: The appearance of the cervical mucosa is regulated by different factors including retinoic acid. Hormone-dependent alteration of the cervix uteri mucosa is accompanied by a decrease or increase of cytoplasmatic retinoic-acid-binding protein (CRABP). To elucidate whether this hormone-dependent alteration of CRABP is preserved in the case of neoplasms of the cervix uteri, we measured the level of total and apo-CRABP in normal and neoplastically transformed cervical cells. METHODS: In a prospective pilot study, standardised biopsies of normal epithelium and cervical intra-epithelial neoplasm grade 3 (CIN III) were taken from 24 patients. A newly developed method was used to determine the intra-epithelial level of apo- and total CRABP. RESULTS: The concentration of total CRABP in normal squamous epithelium compared with that in intra-epithelial neoplasm grade 3 is very significantly lower in the CIN III areas (normal: 3.66 +/- 1.46 pmol/ mg wet weight +/- SD; CIN III 1.43 +/- 0.59 pmol/mg P < 0.01). In addition CRABP in the apo form is lower in normal than in neoplastic epithelium (Wilcoxon test for paired non-parametric values: P < 0.05; mean for all patients: normal: 1.65 + 0.82 pmol/mg; CIN III: 1.14 +/- 0.23 pmol/mg). CONCLUSION: From our results we conclude that, in neoplastically transformed cells, the hormone-dependent CRABP cycle is interrupted. Whether this has consequences for the further development of the neoplastic cells has to be elucidated.


Assuntos
Colo do Útero/química , Receptores do Ácido Retinoico/análise , Displasia do Colo do Útero/química , Neoplasias do Colo do Útero/química , Epitélio/química , Feminino , Humanos , Projetos Piloto , Estudos Prospectivos , Receptores do Ácido Retinoico/química
17.
J Chromatogr A ; 888(1-2): 175-96, 2000 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-10949485

RESUMO

Inverse gas chromatography (IGC) was applied for the determination of the surface characteristics of Tenax carbon fibers and Akzo Nobel Twaron fibers. Furthermore, IGC procedures for the determination of dispersive and acid-base interactions were validated. The data show that too high values for the dispersive component of the surface energy are obtained when the adsorption area occupied by a single adsorbed n-alkane molecule is estimated from parameters of the corresponding liquid. Comparable values are obtained when the Doris-Gray methodology (area per methylene unit) or measured probe areas are employed. For the fibers studied in this work meaningful Gibbs energy values of the acid-base interaction were only obtained with the polarizability approach. When the dispersive interaction of the polar probes with the fiber surface was scaled to the n-alkane interaction via surface tension, the boiling point, or the vapor pressure of the probes often negative acid-base interaction energies were found. From the temperature dependence of the Gibbs energy, the enthalpy of the acid-base interactions of various probes with the carbon and Twaron aramid fibers was determined. However, from these enthalpy values no meaningful acid-base surface parameters could be obtained. Generally, the limited accuracy with which these parameters can be obtained make the usefulness of this procedure questionable. Also the Gibbs energy data of acid-base interaction can provide a qualitative basis to classify the acidity-basicity of the fiber surface. This latter approach requires only a limited data set and is sufficiently rapid to enable the use of IGC as a screening tool for fibers at a production site. For several polar probes significant concentration effects on carbon fibers were observed. At very low probe loadings the interaction with the fiber surface suddenly increases. This effect is caused by the heterogeneity of the interaction energy of the active sites at the surface. A simple procedure to measure the adsorption isotherm at infinite dilution was developed. The determination of the concentration dependence of the interaction of an n-alkane, an acidic and a basic probe was incorporated in the IGC screening procedure of carbon fibers to monitor this heterogeneity.


Assuntos
Cromatografia Gasosa/métodos , Têxteis/análise , Propriedades de Superfície , Termodinâmica
18.
Onderstepoort J Vet Res ; 45(3): 213-4, 1978 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-750962

RESUMO

A total of 32,042 cattle, slaughtered at the Pretoria, Johannesburg and Durban abattoirs, was examined for parafilariosis and as many animals as possible were traced to the farms from which they originated. The disease is most prevalent in the Bushveld areas of the northern Transvaal. The most important factors limiting its distribution are the annual rainfall and the duration of the frost period. Mention is made of some aspects of the economic loss involved. The effect of routine anthelmintic treatment and dipping on the prevalence of the parasite is briefly discussed.


Assuntos
Doenças dos Bovinos/epidemiologia , Filariose/veterinária , Animais , Bovinos , Clima , Filariose/economia , Filariose/epidemiologia , África do Sul
19.
Mol Syndromol ; 1(5): 231-238, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-22140375

RESUMO

Dravet syndrome or severe myoclonic epilepsy in infancy (SMEI) is an epileptic syndrome characterised by refractory epilepsy and intellectual disability, typically presenting with febrile and afebrile generalised and unilateral clonic/tonic-clonic seizures in the first year of life and other types of seizures appearing later in the course of the disease. Five adult patients with SMEI and SCN1A mutations are reported, in which motor and behavioural abnormalities were outstanding symptoms. Bradykinesia, responding with latency, slow speaking with a thin voice, midface hypomimia and perseveration were distinctive features in all cases. These symptoms may be fit to define the adult phenotype of SMEI beyond seizure/epilepsy criteria. The motor and behavioural symptoms are discussed in the context of a possibly underlying frontal lobe/mesofrontal and cerebellar dysfunction.

20.
Artigo em Inglês | MEDLINE | ID: mdl-20931418

RESUMO

A variety of melaware articles were tested for the migration of melamine into the food simulant 3% w/v acetic acid as a benchmark, and into other food simulants, beverages and foods for comparison. The results indicate that the acidity of the food simulant plays a role in promoting migration, but not by as much as might have been anticipated, since 3% acetic acid gave migration values about double those obtained using water under the same time and temperature test conditions. In contrast, migration into the fatty food simulant olive oil was not detectable and at least 20-fold lower than with the aqueous food simulants. This was expected given the solubility properties of melamine and the characteristics of the melaware plastic. Migration levels into hot acidic beverages (apple juice, tomato juice, red-fruit tea and black coffee) were rather similar to the acetic acid simulant when the same time and temperature test conditions are used, e.g. 2 h at 70°C. However, migration levels into foods that were placed hot into melaware articles and then allowed to cool on standing were much lower (6-14 times lower) than if pre-heated food was placed into the articles and then maintained (artificially) at that high temperature in the same way that a controlled time-temperature test using simulants would be conducted. This very strong influence of time and especially temperature was manifest in the effects seen of microwave heating of food or beverage in the melaware articles. Here, despite the short duration of hot contact, migration levels were similar to simulants used for longer periods, e.g. 70°C for 2 h. This is rationalized in terms of the peak temperature achieved on microwave heating, which may exceed 70°C, counterbalancing the shorter time period held hot. There was also evidence that when using melaware utensils in boiling liquids, as for stovetop use of spatulas, the boiling action of circulating food/simulant can have an additional effect in promoting surface erosion, increasing the plastic decomposition and so elevating the melamine release.


Assuntos
Análise de Alimentos , Contaminação de Alimentos , Plásticos/química , Triazinas/análise , Bebidas/análise , Bebidas/efeitos da radiação , Qualidade de Produtos para o Consumidor , Culinária , Utensílios de Alimentação e Culinária , Alimentos/efeitos da radiação , Manipulação de Alimentos/métodos , Embalagem de Alimentos , Formaldeído/química , Concentração de Íons de Hidrogênio , Micro-Ondas/efeitos adversos , Modelos Químicos , Plásticos/efeitos adversos , Plásticos/efeitos da radiação , Temperatura , Fatores de Tempo , Triazinas/química
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