Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 209
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Clin Genet ; 89(6): 700-7, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26757139

RESUMO

The current standard of care for diagnosis of severe intellectual disability (ID) and epileptic encephalopathy (EE) results in a diagnostic yield of ∼50%. Affected individuals nonetheless undergo multiple clinical evaluations and low-yield laboratory tests often referred to as a 'diagnostic odyssey'. This study was aimed at assessing the utility of clinical whole-exome sequencing (WES) in individuals with undiagnosed and severe forms of ID and EE, and the feasibility of its implementation in routine practice by a small regional genetic center. We performed WES in a cohort of 43 unrelated individuals with undiagnosed ID and/or EE. All individuals had undergone multiple clinical evaluations and diagnostic tests over the years, with no definitive diagnosis. Sequencing data analysis and interpretation were carried out at the local molecular genetics laboratory. The diagnostic rate of WES reached 32.5% (14 out of 43 individuals). Genetic diagnosis had a direct impact on clinical management in four families, including a prenatal diagnostic test in one family. Our data emphasize the clinical utility and feasibility of WES in individuals with undiagnosed forms of ID and EE and highlight the necessity of close collaborations between ordering physicians, molecular geneticists, bioinformaticians and researchers for accurate data interpretation.


Assuntos
Exoma/genética , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Transtornos do Neurodesenvolvimento/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Testes Diagnósticos de Rotina/métodos , Testes Diagnósticos de Rotina/tendências , Epilepsia/diagnóstico , Epilepsia/genética , Feminino , Predisposição Genética para Doença/genética , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Masculino , Transtornos do Neurodesenvolvimento/diagnóstico , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
2.
Opt Lett ; 39(20): 5806-9, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25361090

RESUMO

We present an all-fiber concept that generates ultrashort pulses using a passively Q-switched microchip seed laser. A proof-of-principle configuration combines nonlinear pulse compression applying a chirped fiber-Bragg-grating, dispersion-free pulse shortening by means of a fiber-integrated spectral filtering, and a final hollow-core-fiber compression to reach the sub-200-fs pulse-duration region. In a compact all-fiber pulse-shortening unit, initial 100 ps long microchip pulses at 1064 nm wavelength have been shortened to 174 fs and shifted to 1034 nm while preserving a high temporal quality.

3.
Opt Lett ; 39(3): 505-8, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24487851

RESUMO

We present an enhanced technique for dispersion-free pulse shortening, which exploits the interplay of different third-order nonlinear effects in a waveguide structure. When exceeding a certain value of the pulse energy coupled into the waveguide, the typical oscillations of self-phase modulation (SPM)-broadened spectra vanish during pulse propagation. Such smoothed spectra ensure a high pulse quality of the spectrally filtered and, therefore, temporally shortened pulses independently of the filtering position. A reduction of the pulse duration from 138 to 24 ps has been achieved while preserving a high temporal quality. To the best of our knowledge, the nonlinear smoothing of SPM-broadened spectra is used in the context of dispersion-free pulse duration reduction for the first time.

4.
Occup Med (Lond) ; 64(1): 17-22, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24336480

RESUMO

BACKGROUND: Up to 80% of professional musicians are affected by playing-related musculoskeletal disorders, but data regarding the frequency of craniomandibular dysfunction (CMD) in professional orchestra musicians is scarce. AIMS: To evaluate the frequency of CMD and its relation to musculoskeletal pain in various body regions. METHODS: A questionnaire-based survey approach assessing CMD symptoms and musculoskeletal pain in professional orchestra players was adopted. Relative prevalence rates and prevalence ratios for different instrument groups were estimated. RESULTS: A total of 408 musicians completed the questionnaire (response rate 57%). Playing-related pain in the teeth or jaw was reported by 19-47% of musicians and TMJ pain by 15-34%, depending on the instrument group. Current pain in the face indicating a painful CMD was reported in 6-10% and related symptoms such as teeth grinding in 25-34%, jaw clenching in 33-42% and jaw locking in 11-18% of musicians. Females were 2.4 times (95% confidence intervals (CI) 1.49-3.84) more likely to report having had orofacial pain within the last month. Musicians reporting orofacial pain within the last month were 4.8 times (95% CI: 2.83-8.02) more likely to report pain in the neck and 2.5-3.8 times (P < 0.05) more likely to report pain in other body regions, including shoulders, right wrist, left fingers and the thoracic and lumbar spine. CONCLUSIONS: Symptoms suggesting CMD were common in this study of professional orchestra musicians and were associated with pain in the neck, shoulder and hands. There is a need to enhance awareness of CMD to optimize early medical diagnosis and treatment.


Assuntos
Bruxismo/fisiopatologia , Transtornos Craniomandibulares/fisiopatologia , Distúrbios Distônicos/fisiopatologia , Dor Facial/fisiopatologia , Dor Musculoesquelética/fisiopatologia , Música , Doenças Profissionais/fisiopatologia , Adulto , Transtornos Craniomandibulares/diagnóstico , Transtornos Craniomandibulares/psicologia , Estudos Transversais , Feminino , Humanos , Incidência , Masculino , Dor Musculoesquelética/diagnóstico , Doenças Profissionais/diagnóstico , Doenças Profissionais/psicologia , Prevalência , Distribuição por Sexo , Inquéritos e Questionários
5.
Internist (Berl) ; 55(5): 601-6, 2014 May.
Artigo em Alemão | MEDLINE | ID: mdl-24770979

RESUMO

Guidelines for the reduction of cholesterol to prevent atherosclerotic vascular events were recently released by the American Heart Association and the American College of Cardiology. The authors claim to refer entirely to evidence from randomized controlled trials, thereby confining their guidelines to statins as the primary therapeutic option. The guidelines derived from these trials do not specify treatment goals, but refer to the percentage of cholesterol reduction by statin medication with low, moderate, and high intensity. However, these targets are just as little tested in randomized trials as are the cholesterol goals derived from clinical experience. The same applies to the guidelines of the four patient groups which are defined by vascular risk. No major statin trial has included patients on the basis of their global risk; thus the allocation criteria are also arbitrarily chosen. These would actually lead to a significant increase in the number of patients to be treated with high or maximum dosages of statins. Also, adhering to dosage regulations instead of cholesterol goals contradicts the principles of individualized patient care. The option of the new risk score to calculate lifetime risk up to the age of 80 years in addition to the 10-year risk can be appreciated. Unfortunately it is not considered in the therapeutic recommendations provided, despite evidence from population and genetic studies showing that even a moderate lifetime reduction of low-density lipoprotein (LDL) cholesterol or non-HDL cholesterol has a much stronger effect than an aggressive treatment at an advanced age. In respect to secondary prevention, the new American guidelines broadly match the European guidelines. Thus, the involved societies from Germany, Austria and Switzerland recommend continuing according to established standards, such as the EAS/ESC guidelines.


Assuntos
Anticolesterolemiantes/administração & dosagem , Aterosclerose/sangue , Aterosclerose/prevenção & controle , Dietoterapia/normas , Hipercolesterolemia/sangue , Hipercolesterolemia/prevenção & controle , Guias de Prática Clínica como Assunto , Áustria , Cardiologia/normas , Humanos , Fatores de Risco , Suíça
6.
Opt Lett ; 38(14): 2478-80, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23939086

RESUMO

We present a novel concept to generate sub-picosecond pulses from a passively Q-switched Nd:YVO4 microchip laser system with an adjustable wavelength shift up to a few tens of nanometers around the original emission wavelength of 1064 nm. This concept comprises two stages: one that carries out a nonlinear compression of fiber-amplified microchip pulses and a subsequent stage in which the compressed pulses are coupled into a further waveguide structure followed by a bandpass filter. In a proof-of-principle experiment, pedestal-free 0.62 ps long pulses have been demonstrated with a wavelength shift to 1045 nm.

7.
Opt Lett ; 37(21): 4401-3, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23114309

RESUMO

We present a dispersion-free method for the pulse duration reduction of passively Q-switched microchip laser (MCL) seed sources. This technique comprises two stages: one that carries out the self-phase modulation induced spectral broadening in a waveguide structure and a subsequent spectral filtering stage in order to shorten the pulses in time domain. The setup of a proof-of-principle experiment consists of a fiber-amplified passively Q-switched MCL, a passive single-mode fiber used as nonlinear element in which the spectrum is broadened, and a reflective volume-Bragg-grating acting as bandpass filter. A reduction of the pulse duration from 118 to 32 ps with high temporal quality has been achieved with this setup.

8.
Opt Lett ; 37(13): 2550-2, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22743451

RESUMO

We report on high-energy picosecond pulse generation from a passively Q-switched and fiber-amplified microchip laser system. Initially, the utilized microchip lasers produce pulses with durations of around 100 ps at 1064 nm central wavelength. These pulses are amplified to energies exceeding 100 µJ, simultaneously chirped and spectrally broadened by self-phase modulation using a double stage amplifier based on single-mode LMA photonic crystal fibers at repetition rates of up to 1 MHz. Subsequently, the pulse duration of chirped pulses is reduced by means of nonlinear pulse compression to durations of 2.7 ps employing a conventional grating compressor and 4.7 ps using a compact compressor based on a chirped volume Bragg grating.

9.
Plant Cell Rep ; 30(9): 1593-601, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21484331

RESUMO

Panax ginseng C.A. Meyer is one of the most highly valued medicinal plants in the world. To analyze the transcriptome of P. ginseng and discover the genes involved in ginsenoside biosynthesis, cDNAs derived from the total RNA of 11-year-old, wood-grown P. ginseng roots were analyzed by 454 sequencing. A total of 217,529 high quality reads (expressed sequence tags, ESTs), with an average length of 409 bases, were generated from a one-quarter run to yield 31,741 unique sequences. The majority (20,198; 63.6%) of the unique sequences were annotated using BLAST similarity searches. A total of 16,810 and 16,577 unique sequences were assigned to functional classifications and biochemical pathways based on Gene Ontology analysis and the Kyoto Encyclopedia of Genes and Genomes assignment, respectively. Nine genes involved in the biosynthesis of ginsenoside skeletons and many candidate genes putatively responsible for modification of the skeletons, including 133 cytochrome P450s and 235 glycosyltransferases, were identified. From these candidates, six transcripts encoding UDP-glycosyltransferases that were most likely to be involved in ginsenoside biosynthesis were selected. These results open a new avenue by which to explore and exploit biosynthetic and biochemical properties that may lead to drug improvement. These 454 ESTs will provide the foundation for further functional genomic research into the traditional herb P. ginseng or its closely related species.


Assuntos
Etiquetas de Sequências Expressas , Ginsenosídeos/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Panax/genética , Raízes de Plantas/genética , Sistema Enzimático do Citocromo P-450/genética , Biblioteca Gênica , Genes de Plantas , Ginsenosídeos/biossíntese , Glicosiltransferases/genética , Estrutura Molecular , Panax/química , Raízes de Plantas/química , RNA de Plantas/genética , Transcriptoma
10.
Science ; 273(5277): 966-8, 1996 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-8688083

RESUMO

Apolipoproteins are protein constituents of plasma lipid transport particles. Human apolipoprotein A-IV (apoA-IV) was expressed in the liver of C57BL/6 mice and mice deficient in apoE, both of which are prone to atherosclerosis, to investigate whether apoA-IV protects against this disease. In transgenic C57BL/6 mice on an atherogenic diet, the serum concentration of high density lipoprotein (HDL) cholesterol increased by 35 percent, whereas the concentration of endogenous apoA-I decreased by 29 percent, relative to those in transgenic mice on a normal diet. Expression of human apoA-IV in apoE-deficient mice on a normal diet resulted in an even more severe atherogenic lipoprotein profile, without affecting the concentration of HDL cholesterol, than that in nontransgenic apoE-deficient mice. However, transgenic mice of both backgrounds showed a substantial reduction in the size of atherosclerotic lesions. Thus, apoA-IV appears to protect against atherosclerosis by a mechanism that does not involve an increase in HDL cholesterol concentration.


Assuntos
Apolipoproteínas A/fisiologia , Arteriosclerose/prevenção & controle , Animais , Apolipoproteína A-I/sangue , Apolipoproteínas A/sangue , Apolipoproteínas E/sangue , Apolipoproteínas E/deficiência , Colesterol/sangue , HDL-Colesterol/sangue , Dieta Aterogênica , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
11.
Orthopade ; 38(9): 847-54, 2009 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-19609773

RESUMO

BACKGROUND: Complex forms of musculoskeletal dysfunction are thought to be risk factors for the development of chronic pain syndromes of the locomotor system. Unfortunately there are insufficient data on the reliability and validity of clinical tests for musculoskeletal dysfunctions. METHOD: The intrarater and interrater reliability of clinical tests for hypermobility and for the stabilisation system were examined in a multicentre trial. A total of 68 patients in 6 centres were functionally examined by 2 examiners once (intrarater reliability) and by 1 examiner twice (interrater reliability). RESULTS: The tests for hypermobility showed good to very good reliability. The results for the stabilisation system were more variable whereby 23 tests showed a kappa-coefficient greater than 0.5 and 15 tests good to very good reliability. DISCUSSION: All tests for hypermobility and 23 tests for the stabilisation system are suitable for further evaluation. The broad range in test reliability might be explained by the differences in examiner skills demanded by each test. Therefore, dependent on their validity, some tests will be useful in specialized centres while others might be used in primary care.


Assuntos
Ataxia/diagnóstico , Dor nas Costas/etiologia , Instabilidade Articular/diagnóstico , Transtornos dos Movimentos/diagnóstico , Equilíbrio Postural , Adulto , Idoso , Ataxia/complicações , Biometria , Feminino , Humanos , Instabilidade Articular/complicações , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/complicações , Variações Dependentes do Observador , Medição da Dor/estatística & dados numéricos , Valor Preditivo dos Testes , Estudos Prospectivos , Adulto Jovem
12.
Ophthalmologe ; 116(10): 967-969, 2019 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-30737540

RESUMO

Microsurgical procedures in zoo and wildlife animals are challenging because of the reduced perioperative sterility and postoperative care. This case report describes the positive result of the surgical treatment of a perforated corneal ulceration with prolapsed iris in an 18-year-old Grévy's zebra mare. The postoperative development and the results of the histomorphological examination 3.5 years after surgery are described.


Assuntos
Úlcera da Córnea , Equidae , Animais , Córnea , Úlcera da Córnea/veterinária , Feminino , Cavalos
13.
J Small Anim Pract ; 49(12): 660-2, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18684144

RESUMO

An approximately eight-year-old female grey parrot (Psittacus erithacus erithacus) was presented with a two months history of blindness. The radiographic examination showed a dilatation of the proventriculus, ventriculus and gut. Ophthalmoscopy and electroretinography revealed degeneration of the retina. A proventricular dilatation disease was suspected. The bird was euthanased because of deteriorating condition and poor prognosis. The pathological examination showed an atrophy of the ventricular muscles and lymphoplasmacytic infiltrates of the myenteric plexus of the proventriculus, ventriculus and gut as well as moderate lymphoplasmacytic infiltrates of the cerebrum with moderate neuronophagia. Lymphoplasmacytic infiltrates in the retina, indicating proventricular dilatation disease, and subsequent retinal degeneration were found. A potential common aetiology for proventricular dilatation disease and blindness is discussed.


Assuntos
Doenças das Aves/patologia , Cegueira/veterinária , Papagaios , Proventrículo/patologia , Gastropatias/veterinária , Animais , Doenças das Aves/etiologia , Cegueira/etiologia , Evolução Fatal , Feminino , Prognóstico , Gastropatias/complicações , Gastropatias/patologia
14.
J Clin Invest ; 92(2): 1009-17, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8349786

RESUMO

Apolipoprotein (apo) A-IV is a polymorphic, intestinally derived apolipoprotein that is genetically linked to and similar in structure to apoA-I, the major apolipoprotein in high density lipoproteins (HDL). ApoA-IV plays a potentially important role in lipoprotein metabolism and reverse cholesterol transport, but its in vivo metabolism is poorly understood. In order to gain insight into factors modulating apoA-IV metabolism in humans, the in vivo kinetics of the two major human apoA-IV isoproteins apoA-IV-1 and apoA-IV-2 were investigated in normolipidemic human subjects. 131I-apoA-IV-1 and 125I-apoA-IV-2 were reassociated with autologous plasma and injected into study subjects. Analysis of the kinetic data revealed a rapid mean fractional catabolic rate (FCR) for apoA-IV-1 of 2.42 +/- 0.11 d-1. The mean production, or transport, rate of apoA-IV-1 was 16.3 +/- 1.4 mg/kg per d. Plasma apoA-IV concentrations were highly correlated with apoA-IV production rate (r = 0.84, P < 0.001) and not correlated with apoA-IV fractional catabolic rate (r = 0.25, P = NS). The mean FCR of apoA-IV-2 was 2.21 +/- 0.10 d-1. In the ten subjects in whom 131I-apoA-IV-1 and 125I-apoA-IV-2 were simultaneously injected, the FCR of apoA-IV-2 was significantly slower by paired t test (P = 0.003). The FCR of apoA-IV-2 in an apoA-IV-2/2 homozygote was only 1.49 d-1, substantially slower than in all other subjects. We conclude that: (a) apoA-IV is a rapidly catabolized apolipoprotein in humans, with a fractional catabolic rate more than 10 times greater than that of apoA-I; (b) apoA-IV has a high absolute transport rate similar to that of apoA-I; (c) plasma levels of apoA-IV are primarily determined by apoA-IV production rate in normolipidemic subjects; and (d) the fractional catabolic rate of the common variant apoA-IV-2 is slower than that of the wild-type apoA-IV-1.


Assuntos
Apolipoproteínas A/genética , Apolipoproteínas A/metabolismo , Variação Genética , Adulto , Apolipoproteína A-I/isolamento & purificação , Apolipoproteína A-I/metabolismo , Apolipoproteínas A/isolamento & purificação , Cromatografia de Afinidade , Cromatografia em Gel , Feminino , Heterozigoto , Homozigoto , Humanos , Radioisótopos do Iodo , Cinética , Lipoproteínas HDL/sangue , Lipoproteínas VLDL/sangue , Masculino , Fenótipo , Técnica de Diluição de Radioisótopos , Fatores de Tempo
15.
Biochim Biophys Acta ; 454(3): 429-35, 1976 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-999912

RESUMO

Bean (Phaseolus vulgaris) chloroplast tRNAsLeu and tRNAsPhe hybridize to chloroplast DNA, whereas the corresponding cytoplasmic tRNA species do not, suggesting that chloroplast transfer RNAs are coded for by chloroplast DNA. The hybridization of the three chloroplast tRNAsLeu or of the two tRNAsPhe isoacceptors is not additive, and the isoacceptors compete with each other in the hybridization to chloroplast DNA, suggesting that these isoacceptors are coded for by the same gene(s) and differ only in the extent of post-transcriptional modification. Although hererologous aminoacylation reactions and comparisons of base composition suggest a resemblance between chloroplast and procaryotic tRNAs, only a slight cross hybridization reaction was observed between chloroplast and Escherichia coli leucyl- or phenylalanyl-tRNAs and DNAs.


Assuntos
Cloroplastos/metabolismo , DNA , Hibridização de Ácido Nucleico , RNA de Transferência , Citoplasma/metabolismo , DNA/metabolismo , Cinética , Leucina , Fenilalanina , Plantas , RNA de Transferência/metabolismo
16.
Biochim Biophys Acta ; 1006(2): 173-8, 1989 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-2512983

RESUMO

Lecithin-cholesterol acyltransferase (EC 2.3.1.43, LCAT) is the enzyme responsible for the formation of the bulk of cholesteryl ester in human plasma. The LCAT-reaction takes place mainly on high-density lipoproteins and requires an apolipoprotein as activator. Besides apolipoprotein (apo) A-I several other potent activator apolipoproteins (AIV, E and CI) were identified, furthermore apo A-II was shown to be a modulator of the enzyme's reaction in the presence of apo A-I. Serum amyloid A, an apolipoprotein mainly associated with high-density lipoprotein, massively accumulates in plasma upon acute phase reactions. We therefore studied the possible influence of this acute phase reactant on cholesterol esterification in human plasma. There was a significant decrease of esterified cholesterol in plasma during acute phase reaction. We found a highly significant correlation between the unesterified part of plasma cholesterol and serum amyloid A levels (r = 0.694, P = 0.0001). Also, plasma LCAT activity was negatively correlated with serum amyloid A levels. Lipoproteins containing apo A-I and A-II (LpA-I: A-II) and lipoproteins containing apo A-I but no A-II (LpA-I) decreased significantly with the appearance in plasma of serum amyloid A. To study the influence of serum amyloid A on the LCAT reaction, artificial substrates were prepared either by a detergent dialysis procedure or by addition of apolipoprotein to a sonicated aqueous dispersion of lipid. In addition two different molar ratios of apolipoprotein/phospholipid (PC) (1:50 and 1:310) were chosen at a constant molar ratio of total cholesterol/PC of 1:20. The various substrates were incubated with purified LCAT enzyme. DMPC - or egg yolk phosphatidylcholine - cholesterol-[4-14C]cholesterol-serum amyloid A complexes per se did not stimulate LCAT activity significantly. However, apo serum amyloid A incorporated together with apo A-I by a detergent dialysis procedure lead at low concentrations of serum amyloid A to a marked increase in cholesteryl ester formation as compared to apo A-I alone but inhibited the cholesteryl ester formation at high concentrations. Thus, the low levels of esterified cholesterol in acute phase plasma are to some extent due to decreased plasma enzyme activity and in part may be due to interference of apo serum amyloid A with the natural substrate complexes of plasma HDL.


Assuntos
Reação de Fase Aguda/sangue , Ésteres do Colesterol/sangue , Inflamação/sangue , Proteína Amiloide A Sérica/metabolismo , Apolipoproteína A-I , Apolipoproteína A-II , Apolipoproteínas A/sangue , Apolipoproteínas A/metabolismo , Apolipoproteínas A/farmacologia , Colesterol/sangue , Colesterol/metabolismo , Dimiristoilfosfatidilcolina/metabolismo , Ativação Enzimática/efeitos dos fármacos , Esterificação , Humanos , Lipoproteínas HDL/sangue , Fosfatidilcolina-Esterol O-Aciltransferase/sangue , Fosfatidilcolina-Esterol O-Aciltransferase/metabolismo , Proteína Amiloide A Sérica/farmacologia
17.
Biochim Biophys Acta ; 795(2): 314-25, 1984 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-6477948

RESUMO

Low-density lipoproteins (LDL) were modified by incubation with very-low-density lipoproteins (VLDL) and lipid transfer protein(s) to yield LDL particles that were enriched in triacylglycerol, depleted in cholesteryl esters, and contained apolipoprotein C. The uptake and degradation of these 125I-labeled modified LDL particles by cultured skin fibroblasts was reduced by approx. 30% when compared with LDL that had not been exposed to lipid transfer protein. Incubation of fibroblasts for 24 h in the presence of modified LDL resulted in less inhibition of LDL receptor activity and sterol synthesis than did incubation with control LDL. Both the degradation of 125I-labeled modified LDL and the effect of unlabeled modified LDL on the regulation of LDL binding and sterol synthesis were progressively decreased as the extent of modification of the LDL was increased. Even when identical amounts of modified LDL or control LDL protein were degraded, less inhibition of LDL receptor activity and sterol synthesis was observed with modified LDL than with control LDL, suggesting that the effects of modified LDL on these regulatory events are related to both the reduced degradation of the modified lipoprotein particles and to the alteration in its chemical composition. Uptake and degradation of modified LDL by human monocyte-derived macrophages in culture was reduced in a manner similar to that observed in the cultured fibroblasts, and was considerably less than that observed with acetylated LDL. No differences were observed between modified LDL prepared by exposure to lipid transfer activity in the lipoprotein deficient fraction of serum or when partially purified lipid transfer was used. Modified LDL, with similar composition to that used in the experiments, has been observed in certain diabetic and non-diabetic hypertriglyceridemic states. Thus, it is possible that the cellular metabolism of LDL in vivo might be altered in the presence of hypertriglyceridemia.


Assuntos
Proteínas de Transporte/metabolismo , Lipoproteínas LDL/metabolismo , Lipoproteínas VLDL/metabolismo , Acetatos/metabolismo , Ácido Acético , Radioisótopos de Carbono , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Hiperlipoproteinemia Tipo IV/sangue , Cinética , Macrófagos/metabolismo , Receptores de LDL/metabolismo , Valores de Referência , Pele/metabolismo , Esteróis/biossíntese
18.
Biochim Biophys Acta ; 992(3): 407-8, 1989 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2775795

RESUMO

Antipeptide antibodies raised against two distinct sequences of human serum amyloid A (SAA) discriminate between different plasma isoforms of this acute phase reactant. As different SAA gene products have meanwhile been identified in human plasma, the discrimination between these different isoforms may help to clarify further the time of appearance of these different forms in plasma and their potential amyloidogenicity.


Assuntos
Proteína Amiloide A Sérica/análise , Anticorpos , Ensaio de Imunoadsorção Enzimática , Humanos , Immunoblotting , Proteína Amiloide A Sérica/imunologia
19.
Biochim Biophys Acta ; 378(1): 64-72, 1975 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-1091292

RESUMO

Leucyl-tRNA synthetase from Phaseolus vulgaris chloroplasts could be separated from its cytoplasmic counterpart upon chromatography on hydroxyapatite, but the cytoplasmic and mitochondrial leucyl-tRNA synthetases could not be distinguished. The tRNALeu species from the various plant cell compartments and from Escherichia coli were aminoacylated using either homologous or heterologous enzymes; the levels of aminoacylation and the profiles of the leucyl-tRNAs upon reverse-phase chromatography were studied. Cytoplasmic tRNALeu species could be aminoacylated by the cytoplasmic or by the mitochondrial enzymes and in both cases yielded two peaks upon reverse-phase chromatography (RPC-5). But they could not be charged by the chloroplast-specific or by the E. coli enzynes. Mitochondrial tRNALeu species could be charged by the mitochondrial or by the cytoplasmic enzymes and in both cases yielded four peaks upon reverse phase (RPC-5) chromatography. But they could not be aminoacylated using the chloroplast-specific or the E. coli leucyl-tRNA synthetases. Chloroplastic tRNALeu species can be divided into two classes: the first class contains four isoacceptor species which can be charged by the cytoplasmic or mitochondrial enzymes, but not by the chloroplast-specific or the E. coli enzymes; the second class contains three chloroplast-specific tRNALeu species which can be charged by the chloroplast-specific or the E. coli enzymes but not by the cytoplasmic or the mitochondrial enzymes. There are five isoacceptor tRNALeu species in E. coli; all are charged by the E. coli or the chloroplast-specific enzymes, while only one is aminoacylated by the plant cytoplasmic or mitochondrial enzymes.


Assuntos
Aminoacil-tRNA Sintetases/metabolismo , Cloroplastos/enzimologia , Escherichia coli/enzimologia , Mitocôndrias/enzimologia , Plantas/enzimologia , Aminoacil-tRNA Sintetases/isolamento & purificação , Centrifugação com Gradiente de Concentração , Cromatografia , Cromatografia por Troca Iônica , Citoplasma/enzimologia , Cinética , Leucina , Magnésio/farmacologia
20.
Biochim Biophys Acta ; 609(1): 31-9, 1980 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-7407185

RESUMO

Chloroplast tRNAs from two dicotyledons (spinach and bean), a monocotyledon (maize) and a green alga (Euglena) have been fractionated by two-dimensional gel electrophoresis. The individual tRNAs have been identified, albeled with 125I or 32P, and used in tRNA-DNA hybridization experiments. Spinach chloroplast tRNAs hybridize as well, and maize chloroplast tRNAs almost as well as bean chloroplast tRNAs to bean chloroplast DNA, thus suggesting a high degree of homology between the chloroplast tRNAs from the two dicotyledons and between the tRNAs from the two dicotyledons and those of the monocotyledon. But Euglena total chloroplast tRNA hybridizes very poorly to bean chloroplast DNA, and among the 14 individual tRNAs tested, only one, Euglena chloroplast tRNAPhe, hybridizes to both maize and bean chloroplast DNAs, which is in good agreement with the fact that Euglena and bean chloroplast tRNAsPhe have almost identical primary structures.


Assuntos
DNA/genética , RNA de Transferência/genética , Aminoácidos/análise , Cloroplastos/análise , Eletroforese em Gel de Poliacrilamida , Euglena/genética , Fabaceae/genética , Hibridização de Ácido Nucleico , Plantas/genética , Plantas Medicinais , Zea mays/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA