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1.
J Intellect Disabil Res ; 68(6): 564-572, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38413188

RESUMO

BACKGROUND: Active Support is a person-centred practice that enables people with intellectual disabilities (IDs) to engage in meaningful activities and social interactions. The Active Support Measure (ASM) is an observational tool designed to measure the quality of support that people with IDs living in supported accommodation services receive from staff. The aim of the study was to explore the underlying constructs of the ASM. METHODS: Multilevel exploratory factor analysis was conducted on ASM data (n = 884 people with IDs across 236 accommodation services) collected during a longitudinal study of Active Support in Australian accommodation services. RESULTS: Multilevel exploratory factor analysis indicated that 12 of the ASM's 15 items loaded on two factors, named Supporting Engagement in Activities and Interacting with the Person. CONCLUSIONS: The 12-item ASM measures two dimensions of the quality of staff support. Both technical and interpersonal skills comprise good Active Support.


Assuntos
Deficiência Intelectual , Humanos , Adulto , Masculino , Feminino , Análise Fatorial , Pessoa de Meia-Idade , Estudos Longitudinais , Austrália , Adulto Jovem , Adolescente , Assistência Centrada no Paciente/normas , Apoio Social , Interação Social
2.
J Intellect Disabil Res ; 61(2): 155-167, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27283246

RESUMO

BACKGROUND: The present study aimed to explore the applicability of the attribution model to social workers' attributions towards clients with dual diagnosis of intellectual disability and psychiatric illness. Specifically, the study examined the relations between social workers' attribution of responsibility, causality, stereotypes of dangerousness, their emotional reactions and behavioural reactions towards clients with dual diagnosis. METHOD: Social workers (N = 279) completed questionnaires measuring attributions of responsibility, causation and dangerousness, and reported on their emotional and behavioural reactions to clients diagnosed with DD. RESULTS: Most social workers reported high levels of helping behaviours. The strongest predictor of discriminatory behaviours was the stereotype of dangerousness. Social workers who reported feeling less anger and more pity towards clients with DD tended to report higher levels of helping behaviour. But contrary to attribution theory, fear and anger did not predict discriminatory behaviours. CONCLUSION: The results are discussed in relation to the core values of social work and to professional identity.


Assuntos
Atitude do Pessoal de Saúde , Comportamento de Ajuda , Deficiência Intelectual/psicologia , Transtornos Mentais/psicologia , Assistentes Sociais/psicologia , Estereotipagem , Adulto , Comorbidade , Feminino , Humanos , Deficiência Intelectual/epidemiologia , Masculino , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade
3.
Allergy ; 68(5): 585-92, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23464525

RESUMO

BACKGROUND: Allergy to dog (Canis familiaris) is a worldwide common cause of asthma and allergic rhinitis. However, dander extract in routine diagnostics is not an optimal predictor of IgE-mediated dog allergy. Our objective was to evaluate saliva as an allergen source for improved diagnostics of allergy to dog. METHODS: IgE-binding proteins in dog saliva and dander extract were analysed by immunoblot and mass spectrometry (LC-MS/MS) using pooled or individual sera from dog-allergic patients (n = 13). Sera from 59 patients IgE positive to dander and 55 patients IgE negative to dander but with symptoms to dog were analysed for IgE against saliva and dander by ELISA. Basophil stimulation with dog saliva and dander extract was measured by flow cytometry among three dog-allergic patients. Additionally, IgE-binding protein profiles of saliva from different breeds were investigated by immunoblot. RESULTS: Greater number and diversity of IgE-binding proteins was found in saliva compared to dander extract and varied among dog breeds. In saliva, Can f 1, 2, 3 and 6 were identified but also four new saliva allergen candidates. The majority of the 59 dog dander-positive sera (n = 44) were IgE positive to dog saliva. Among patients IgE negative to dander, but with symptoms to dog, 20% were IgE positive to saliva. The biological activity of saliva was confirmed by basophil degranulation. CONCLUSIONS: Dog saliva is an allergen source for improved diagnostics of dog allergy. The IgE-binding protein profile of saliva from different dogs varies.


Assuntos
Alérgenos/imunologia , Saliva/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alérgenos/química , Alérgenos/metabolismo , Animais , Basófilos/imunologia , Criança , Pré-Escolar , Cães , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Hipersensibilidade/sangue , Hipersensibilidade/diagnóstico , Hipersensibilidade/imunologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina E/metabolismo , Lactente , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Saliva/química , Proteínas e Peptídeos Salivares/imunologia , Proteínas e Peptídeos Salivares/metabolismo , Espectrometria de Massas em Tandem , Adulto Jovem
4.
J Autism Dev Disord ; 53(5): 1834-1849, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35239083

RESUMO

Parents of children with autism spectrum disorder and other disabilities report high levels of distress, but systematically evaluated interventions are few. This study aimed to evaluate the feasibility of a novel, manualized Acceptance and Commitment Therapy group intervention (Navigator ACT) in a sample of 94 parents of children with disabilities. Feasibility was measured by treatment completion, credibility, and satisfaction, and preliminary outcomes by using self-rating scales administered at the baseline, post-intervention, and follow-up. The results imply the intervention is feasible in the context of Swedish outpatient habilitation services. A preliminary analysis of the outcome measures suggests that parents experienced significant improvements in well-being. The results indicate that the treatment is feasible and should be evaluated in a randomized controlled trial.


Assuntos
Terapia de Aceitação e Compromisso , Transtorno do Espectro Autista , Crianças com Deficiência , Criança , Humanos , Transtorno do Espectro Autista/terapia , Estudos de Viabilidade , Pais
5.
Undersea Hyperb Med ; 37(1): 35-48, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20369651

RESUMO

This report describes how 27 patients with severe traumatic brain injury were safely treated, monitored and managed in a monoplace chamber that was compressed with air to 1.5 atmospheres absolute (152 kPa). A total of 75 hyperbaric oxygen treatments were delivered using the monoplace system described, with all patients receiving 100% oxygen via mechanical ventilation. Specific pieces of equipment, components and features were selected, and modifications were interfaced to safely and effectively treat these critically ill patients in a monoplace chamber. Patient monitoring included cardiovascular and ventilatory parameters as well as intracranial pressure, brain tissue oxygen levels, brain temperature and cerebral microdialysis. The chamber and all the supporting equipment for ventilating, monitoring and managing the patient functioned well.


Assuntos
Câmaras de Exposição Atmosférica , Lesões Encefálicas/terapia , Oxigenoterapia Hiperbárica/instrumentação , Protocolos Clínicos , Desenho de Equipamento , Humanos , Oxigenoterapia Hiperbárica/efeitos adversos , Oxigenoterapia Hiperbárica/métodos
6.
Science ; 198(4319): 853-5, 1977 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-918670

RESUMO

Visual fixations of 3- to 5-week-old, 7-week-old, and 9- to 11-week-old infants were recorded as they scanned an adult's face which was stationary, moving, or talking. A dramatic increase in face fixations occurred between 5 and 7 weeks for all conditions. Talking produced an intensification of scanning in the eye area in the two older groups.


Assuntos
Face , Fixação Ocular , Recém-Nascido , Envelhecimento , Desenvolvimento Infantil , Humanos , Lactente , Mães , Comportamento Social
7.
Science ; 273(5279): 1231-3, 1996 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-8703058

RESUMO

Upon contact with the eukaryotic cell, Yersinia pseudotuberculosis increased the rate of transcription of virulence genes (yop), as determined by in situ monitoring of light emission from individual bacteria expressing luciferase under the control of the yopE promoter. The microbe-host interaction triggered export of LcrQ, a negative regulator of Yop expression, via the Yop-type III secretion system. The intracellular concentration of LcrQ was thereby lowered, resulting in increased expression of Yops. These results suggest a key role for the type III secretion system of pathogenic bacteria to coordinate secretion with expression of virulence factors after physical contact with the target cell.


Assuntos
Aderência Bacteriana , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Virulência/genética , Yersinia pseudotuberculosis/patogenicidade , Proteínas da Membrana Bacteriana Externa/biossíntese , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/genética , Cálcio/metabolismo , Meios de Cultura , Citosol/metabolismo , Células HeLa , Humanos , Mutação , Regulação para Cima , Yersinia pseudotuberculosis/genética , Yersinia pseudotuberculosis/metabolismo
8.
Cell Mol Life Sci ; 65(24): 3961-70, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19011745

RESUMO

Zinc plays an important role in the structure and function of many enzymes, including alcohol dehydrogenases (ADHs) of the MDR type (mediumchain dehydrogenases/reductases). Active site zinc participates in catalytic events, and structural site zinc maintains structural stability. MDR-types of ADHs have both of these zinc sites but with some variation in ligands and spacing. The catalytic zinc sites involve three residues with different spacings from two separate protein segments, while the structural zinc sites involve four residues and cover a local segment of the protein chain (Cys97-Cys111 in horse liver class I ADH). This review summarizes properties of both ADH zinc sites, and relates them to zinc sites of proteins in general. In addition, it highlights a separate study of zinc binding peptide variants of the horse liver ADH structural zinc site. The results show that zinc coordination of the free peptide differs markedly from that of the enzyme (one His / three Cys versus four Cys), suggesting that the protein zinc site is in an energetically strained conformation relative to that of the peptide. This finding is a characteristic of an entatic state, implying a functional nature for this zinc site.


Assuntos
Álcool Desidrogenase/química , Álcool Desidrogenase/metabolismo , Família Multigênica , Zinco/metabolismo , Sequência de Aminoácidos , Animais , Catálise , Domínio Catalítico , Humanos , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/metabolismo
9.
Cell Mol Life Sci ; 65(24): 4019-27, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18850316

RESUMO

Zinc binding to the peptide replica and analogs to residues 93-115 of horse liver alcohol dehydrogenase (ADH) was examined by competition of the peptides and the chromophoric chelator 4-(2- pyridylazo)resorcinol for zinc and X-ray absorption fine structure analysis of the zinc ligands. In the enzyme, zinc is coordinated by four Cys residues. In the peptide replica, zinc is bound to three Cys and one His residue. A four-Cys zinc coordination is observed only when His is removed, leading to increased zinc stability. ADH crystal structures reveal that the epsilon-amino group of the conserved residue Lys323 is within H-bond distance of the backbone amide oxygens of residues 103, 105 and 108, likely stabilizing the zinc coordination in the enzyme. The peptide data thus indicate structural strain and increased energy in the zinc-binding site in the protein, characteristic of an entatic state, implying a functional nature for this zinc site.


Assuntos
Álcool Desidrogenase/química , Álcool Desidrogenase/metabolismo , Peptídeos/metabolismo , Zinco/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Catálise , Domínio Catalítico , Cromatografia em Gel , Análise de Fourier , Cavalos , Cinética , Ligantes , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/química , Titulometria
11.
Biochim Biophys Acta ; 1293(2): 277-83, 1996 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-8620041

RESUMO

P1-N6-(4-azidophenylethyl)adenosine-P2-4-(3-azidopyridinio)b utyl diphosphate was synthesized with an [8-14C]adenine label. This bifunctional photoaffinity labelling reagent inactivates lactate dehydrogenase from pig heart upon irradiation with light of wavelength 300-380 nm. Stoichiometry of binding and enzymatic parameters suggest that the analogue is bound to the coenzyme binding site and that adjacent residues are modified. Four radioactive peptides were isolated by reverse-phase HPLC after tryptic digestion of the labelled protein. Amino-acid sequence analysis identified the peptides and correlation with the three-dimensional structure of dogfish lactate dehydrogenase reveals that the peptides correspond to positions affecting the coenzyme binding site, consistent with proper affinity labelling. Two of the peptides, Ile-77 --> Lys-81 and Asp-82 --> Asn-88, are located close to the adenine binding site. Low recovery of Thr-86 in combination with the detection of additional products in the sequence analysis indicates that this residue is modified by the photoaffinity label. The two other peptides (positions 119-124 and 318-328) are located next to the substrate binding site; their label is lost upon treatment with pyrophosphatase, showing that they are linked to the pyridinio moiety of the coenzyme analogue.


Assuntos
Marcadores de Afinidade/metabolismo , Azidas/metabolismo , L-Lactato Desidrogenase/metabolismo , Miocárdio/enzimologia , NAD/análogos & derivados , Marcadores de Afinidade/síntese química , Marcadores de Afinidade/química , Sequência de Aminoácidos , Animais , Azidas/síntese química , Azidas/química , Azidas/farmacologia , Sítios de Ligação , Ligação Competitiva , Cromatografia Líquida de Alta Pressão , Reagentes de Ligações Cruzadas/síntese química , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/metabolismo , Difosfatos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Cinética , L-Lactato Desidrogenase/antagonistas & inibidores , L-Lactato Desidrogenase/química , Luz , Dados de Sequência Molecular , Estrutura Molecular , NAD/síntese química , NAD/química , NAD/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Ligação Proteica , Suínos
12.
Diabetes ; 38(7): 819-24, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2737363

RESUMO

A laser Doppler device with the capability to simultaneously measure skin blood flow, microvascular volume, and erythrocyte velocity was used to assess blood flow changes in 35 insulin-dependent diabetes mellitus (IDDM) subjects, mean age 33 +/- 1 yr, with average duration of diabetes 14 +/- 1 yr, and in a nondiabetic control group. Blood flow was determined at 35 and 44 degree C at several sites on the upper and lower extremities with a temperature-regulated probe. Blood flow was highest at both temperatures on the pulps of the index finger and the first toe, regions of high density of arteriovenous anastomoses. There was significantly greater blood flow at most locations for the nondiabetic than the diabetic group at 35 degree C, and the differences between the two groups were substantially larger at 44 degree C. At 44 degree C, blood flow in the control group was approximately 40% greater in the upper extremity and 50% greater in the lower extremity than it was in the diabetic subjects. The differences were attributed to decreases of both microvascular volume and velocity in the diabetic group. In the upper extremity, volumes in the diabetic patients were 10-15% lower and velocities 10-40% lower than in the nondiabetic subjects. In the lower extremity, volumes were 20-25% lower and velocities 40-50% lower. We conclude that laser Doppler techniques can be used to assess microvascular changes in the skin of diabetic patients. This approach may be useful to evaluate and model diabetic microangiopathy.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Pele/irrigação sanguínea , Adulto , Velocidade do Fluxo Sanguíneo , Contagem de Eritrócitos/métodos , Feminino , Temperatura Alta , Humanos , Lasers , Masculino , Microcirculação/patologia , Fluxo Sanguíneo Regional , Ultrassom/métodos
13.
J Mol Biol ; 242(4): 397-407, 1994 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-7932699

RESUMO

The purification and characterization of a new type of thermostable chaperonin from the archaebacterium Sulfolobus solfataricus is described. The chaperonin forms a hetero-oligomeric complex of two different, but closely related, subunits, which we have assigned TF55-alpha and TF55-beta. Their N-terminal sequences and amino acid residue compositions are reported. Two-dimensional projections of the chaperonin have been reconstructed from electron microscopy images, showing a 9-fold symmetrical complex, about 17.5 nm in height and 16 nm in diameter, with a central cavity of 4.5 nm. The complex is resistant to denaturing agents at room temperature and only pH values lower than 2 lead to dissociation. The separated subunits do not reassemble spontaneously but require Mg2+ and ATP for complex formation. Both subunits are necessary for formation of the TF55 oligomer. Significant structural changes have been observed after phosphorylation, thus providing evidence for a structural mobility during the chaperonin-assisted folding process of a protein. The phosphorylation reaction is modulated by potassium and magnesium ions. Magnesium seems to have an inhibitory effect, whereas potassium enhances this reaction.


Assuntos
Proteínas de Choque Térmico/metabolismo , Chaperonas Moleculares/metabolismo , Sulfolobus/metabolismo , Sequência de Aminoácidos , Proteínas Arqueais , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/isolamento & purificação , Proteínas de Choque Térmico/ultraestrutura , Microscopia Eletrônica , Chaperonas Moleculares/química , Chaperonas Moleculares/isolamento & purificação , Chaperonas Moleculares/ultraestrutura , Dados de Sequência Molecular , Fosforilação
14.
Diabetes Care ; 12(9): 636-40, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2791826

RESUMO

Detailed clinical neurological examinations were conducted on 44 nondiabetic volunteers and 59 diabetic subjects. The examinations focused particularly on sensory symptomatic and physical evaluation. Standardized assessment of symptoms and physical testing of light touch, pain, vibratory, and thermal sensation was performed at the hand, wrist, elbow, foot, ankle, and knee. A total symptom score and physical score were defined by summing test scores at each site. Current perception threshold (CPT) testing that used constant sine-wave-alternating current was conducted at the same anatomic sites. CPT correlations with the physical score gave r values of .55 for 5 Hz, .60 for 250 Hz, and .62 for 2000 Hz (n = 618). Correlations with the symptom score were not as strong: r = .45 for 5 Hz, .46 for 250 Hz, and .51 for 2000 Hz. The correlation with symptom score was due primarily to a strong relationship for the symptom of numbness (r = .53 for all 3 frequencies). Correlations with pain and paresthesia were much lower. CPTs for diabetic subjects at the three frequencies were higher at most locations than for the nondiabetic volunteers. However, CPTs were no different from normal values in diabetic subjects without evidence of neuropathy. CPT testing appears to be a useful technique for assessment of diabetic sensory neuropathy.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Neuropatias Diabéticas/diagnóstico , Limiar Sensorial , Adulto , Neuropatias Diabéticas/fisiopatologia , Feminino , Humanos , Masculino , Exame Neurológico , Dor/fisiopatologia , Valores de Referência
15.
J Bone Miner Res ; 6(4): 365-73, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1830446

RESUMO

Certain physicochemical properties of rat bone tartrate-resistant acid ATPase (TrATPase), including the size and shape of the enzyme, potential subunit composition, and detergent binding, have been elucidated. SDS-polyacrylamide gel electrophoresis in combination with immunoblot analysis showed that the bone TrATPase has a molecular weight of 33,000 D and is composed of disulfide-linked polypeptides of 20,000 and 16,000 D. The enzyme contains 1.7 mol Fe per mol enzyme. Hydrodynamic studies allowed calculation of the Stokes radius (24 A), the sedimentation coefficient (3.19S), the partial specific volume (0.748 ml/g), the frictional ratio (0.995), and the axial ratio (1.0). The amount of detergent bound to the protein was determined to 4 mol of Triton X-100 per mol enzyme. The molecular weight of bone TrATPase derived from these parameters was 31,900 D. N-terminal amino acid sequence analysis of the Mr 20,000 subunit indicated a high degree of similarity with TRAP enzymes from spleen, uterus, placenta, hairy cell leukemia, and osteoclastoma. It is concluded that rat bone TrATPase belongs to the type 5 (tartrate-resistant and purple) acid phosphatase family. The similarities in the N-terminal amino acid sequences, iron content, and physicochemical properties of TRAP enzymes indicate a close structural relationship between type 5 acid phosphatases expressed in different tissues. The findings that TrATPase has a spherical shape and binds low amounts of detergent suggest that the enzyme is a soluble protein, compatible with the view that TrATPase is secreted by the osteoclast.


Assuntos
Fosfatase Ácida/análise , Adenosina Trifosfatases/análise , Osso e Ossos/enzimologia , Isoenzimas/análise , Tartaratos/farmacologia , Sequência de Aminoácidos , Animais , Centrifugação com Gradiente de Concentração , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Immunoblotting , Ferro/análise , Dados de Sequência Molecular , Ratos , Homologia de Sequência do Ácido Nucleico
16.
J Clin Endocrinol Metab ; 82(11): 3813-7, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9360546

RESUMO

Previously, we reported the identification of a new human GH receptor (hGHR) messenger RNA species that encodes a smaller hGHR isoform, termed hGHRtr. Its messenger RNA is expressed in several human tissues and predicts a severely truncated GHR protein that lacks 97.5% of the intracellular domain. Because these two hGHR isoforms, which display similar binding affinity, are coexpressed in several tissues, they may reside side by side and, therefore, interrelate. To further characterize the biological properties of hGHRtr in comparison with hGHR, we generated Chinese hamster ovary (CHO) cell lines stably expressing each of these hGHR isoforms. Cross-linking of [125I]hGH to CHO/hGHRtr cells revealed a majored specific complex with apparent Mr of approximately 100 kDa, which would indicate the hGHRtr to be in molecular mass form of about 80 kDa. When compared with CHO/hGHR, CHO/hGHRtr cells secreted higher amounts of soluble GH-binding protein (GHBP). In contrast to CHO/hGHR cells, CHO/hGHRtr cells did not exhibit any GH-induced receptor down-regulation, and internalization was markedly reduced. Analysis of the constitutive turnover of cellular hGHR and soluble GHBP showed that incubation of CHO/hGHR cells with cycloheximide caused parallel disappearance of hGHR and GHBP. This contrasted with the stability of GHRtr, which showed no decline after cycloheximide treatment for up to 4 h, suggesting that the bulk GHRtr and GHBP may be derived from preformed proteins. Thus, in contrast to hGHR, hGHRtr is fixed at the cell membrane; it undergoes minimal internalization, no down-regulation by hGH, no constitutive turnover for as long as 4 h, but increased capacity to generate a soluble GHBP. Because hGHRtr failed to undergo ligand-induced internalization, the source of the continuous, undisturbed GHBP released into the medium may be from an intracellular storage pool. The relative abundance of these two hGHR isoforms, through regulation of splicing, could be of critical importance in modulating the biological effects of GH.


Assuntos
Membrana Celular/metabolismo , Receptores da Somatotropina/genética , Animais , Células CHO , Proteínas de Transporte/metabolismo , Cricetinae , Reagentes de Ligações Cruzadas , Regulação para Baixo , Expressão Gênica , Hormônio do Crescimento Humano/metabolismo , Hormônio do Crescimento Humano/farmacologia , Humanos , Cinética , Peso Molecular , RNA Mensageiro/análise , Receptores da Somatotropina/química , Receptores da Somatotropina/metabolismo , Transfecção
17.
Pharmacogenetics ; 7(5): 355-60, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9352570

RESUMO

A conjugate of S-mephenytoin excreted in urine of extensive but not of poor metabolizers of S-mephenytoin has previously been reported. This conjugate, which is easily hydrolysed back to S-mephenytoin, has now been isolated and identified in urine from one extensive metabolizer after a single dose of 100 mg racemic mephenytoin. High performance liquid chromatography purification, followed by gas chromatographic, mass spectrometric and amino acid analyses showed that the isolated compound is a cysteine conjugate of S-mephenytoin. The significant mass spectrometric ions have been confirmed in three additional extensive metabolizers of S-mephenytoin, but were not detectable in urine from three poor metabolizer subjects. The exact structure of the conjugate is unknown, but we suggest that an S-N bond between cysteine and S-mephenytoin is formed via an oxidative radical mechanism catalyzed by CYP2C19.


Assuntos
Cisteína/metabolismo , Mefenitoína/farmacocinética , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Mefenitoína/urina , Fenótipo
18.
FEBS Lett ; 283(1): 100-3, 1991 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-2037061

RESUMO

Capillary zone electrophoresis of peptides on a preparative scale and direct analysis of both amino acid sequences and compositions are demonstrated. Using native and synthetic peptides prepared by repetitive runs and appropriate collections, sufficient material for direct sequence analysis is obtained after just a few runs, while single runs suffice for total compositions. Electrophoretic direct amino acid analysis without derivatization is also possible and gives especially high sensitivity for aromatic residues (less than 200 fmols) plus convenient distinction of amidated versus free C-terminal residues after carboxypeptidase digestions.


Assuntos
Aminoácidos/química , Peptídeos/química , Cromatografia Líquida de Alta Pressão , Eletroforese
19.
FEBS Lett ; 213(2): 385-90, 1987 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-3104091

RESUMO

The DNA sequence of the Bacillus subtilis sdh operon coding for the two succinate dehydrogenase subunits and cytochrome b-558 (the membrane anchor protein) has recently been established. We have now determined the extent of N-terminal processing of each polypeptide by radiosequence analysis. At the same time, direct evidence for the correctness of the predicted reading frames has been obtained. The cytochrome showed a ragged N-terminus, with forms lacking one residue, and is inserted across the membrane without an N-terminal leader-peptide. Covalently bound flavin was not detectable in B. subtilis succinate dehydrogenase expressed in Escherichia coli despite normal N-terminal processing of the apoprotein. This provides an explanation to why the succinate dehydrogenase synthesized in E. coli is not functional and demonstrates that host-specific factors regulate the coenzyme attachment.


Assuntos
Bacillus subtilis/enzimologia , Grupo dos Citocromos b/metabolismo , Escherichia coli/enzimologia , NADPH Oxidases , Processamento de Proteína Pós-Traducional , Succinato Desidrogenase/metabolismo , Sequência de Aminoácidos , Bacillus subtilis/genética , Sequência de Bases , Membrana Celular/enzimologia , Grupo dos Citocromos b/genética , DNA Bacteriano/genética , Escherichia coli/genética , Flavinas/metabolismo , Fragmentos de Peptídeos , Succinato Desidrogenase/genética
20.
FEBS Lett ; 397(1): 45-9, 1996 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-8941711

RESUMO

In the separation of peptides by capillary electrophoresis and analysis by matrix assisted laser desorption mass spectrometry, strong suppression of the mass spectrometric signals is a problem with many common electrolytes used in the separation step such as sodium phosphate. We describe an approach employing individual electrolytes selected for highest performance in each process. Suppression with samples collected into phosphate buffers is avoided when citrate, trifluoroacetic acid or hydrochloric acid is used for collection, while phosphate still provides excellent resolution in the capillary. Low concentrations of hydrochloric acid added to the sample/matrix mixture generate essentially adduct-free mass spectra with better signal-to-noise ratios and detection limits (fmol range) than those obtained with citrate or trifluoroacetic acid. Addition of 0.25% ethylene glycol to both the phosphate electrolyte and the sample improves peak shape and resolution, and is crucial for preparative separations in large diameter capillaries.


Assuntos
Eletroforese Capilar , Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Adsorção , Sequência de Aminoácidos , Ácido Cítrico , Ácido Clorídrico , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Ácido Trifluoracético
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