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1.
Mult Scler ; 19(2): 179-87, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22653658

RESUMO

BACKGROUND: Treatment with glatiramer acetate (GA) modestly decreases disease activity in multiple sclerosis (MS). The mechanism of action is incompletely understood and differences in the response to treatment between individuals may exist. OBJECTIVE: To study the activation of CD4+ T cells, monocytes and dendritic cells (DC) in relation to disease activity in MS patients treated with GA. METHODS: Flow cytometry was used to study the activation of CD4+ T cells and T cell subsets (CD25(high) and CD26(high) cells), monocytes and DCs in a cross-sectional study of 39 untreated and 29 GA-treated MS patients, the latter followed prospectively for one year. Gd-enhanced magnetic resonance imaging (MRI) studies were conducted in all patients. Disease activity was assessed as relapses. RESULTS: The median percentage of DCs expressing CD40 was 10% in untreated MS patients and 5.9% in GA-treated patients (Bonferroni-corrected p=0.0005). The hazard ratio of relapse was 1.32 (95% confidence interval 1.05-1.64) per 1% increase in CD40+ DCs. Patients treated with GA had fewer CD4+ T cells expressing surface markers associated with T helper type 1 effector responses and more CD4+ T cells expressing surface markers associated with regulatory, naïve or central memory T cell populations, but CD4+ T cell activation was not related with relapse risk. CONCLUSIONS: MS patients treated with GA show prominent changes in circulating antigen-presenting cells and CD4+ T cells. Expression of CD40 on DCs is significantly lower and associated with relapse risk in MS patients treated with GA.


Assuntos
Células Dendríticas/fisiologia , Imunossupressores/uso terapêutico , Monócitos/fisiologia , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/patologia , Peptídeos/uso terapêutico , Linfócitos T/fisiologia , Adulto , Células Apresentadoras de Antígenos , Linfócitos T CD4-Positivos/fisiologia , Antígenos CD40/análise , Feminino , Citometria de Fluxo , Acetato de Glatiramer , Cadeias HLA-DRB1/genética , Humanos , Ativação Linfocitária/efeitos dos fármacos , Contagem de Linfócitos , Ativação de Macrófagos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/genética , Recidiva , Adulto Jovem
2.
Mult Scler ; 18(3): 305-13, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22020419

RESUMO

BACKGROUND: Glatiramer acetate (GA) treatment suppresses disease activity in multiple sclerosis (MS). The immunological response to treatment may differ in patients who are stable on GA therapy and patients with breakthrough disease activity, but the results of previous studies are inconsistent. OBJECTIVES: We studied the immunological response to GA and its relationship with disease activity. METHODS: Anti-GA antibodies in plasma and the expression of genes encoding cytokines and T-cell-polarizing transcription factors in blood cells were analysed by flow cytometric bead array and polymerase chain reaction (PCR) analysis in 39 untreated and 29 GA-treated relapsing-remitting MS patients. Definition of breakthrough disease was based on the occurrence of relapses, disability progression, or gadolinium (Gd)-enhanced MRI. RESULTS: The expression of T helper type 1 (Th1) and Th17 cytokines and transcription factors was reduced during long-term treatment, but there was no relationship between the expression of cytokines and transcription factors and anti-GA antibodies. High expression of mRNA encoding GATA3 and lymphotoxin-ß (LT-ß) was associated with low disease activity in Gd-enhanced MRI studies. None of the variables studied were associated with clinical disease activity. GA treatment resulted in the development of IgG and IgG4 anti-GA antibodies during the first months of treatment, persisting during long-term treatment. CONCLUSIONS: The observed relationship between the expression of mRNA encoding GATA3 and LT-ß expression and MRI disease activity deserves further analysis in future studies. The development of anti-GA antibodies was observed in all patients treated with GA, but this was not related with measures of cellular immunity, clinical or MRI disease activity.


Assuntos
Expressão Gênica/efeitos dos fármacos , Esclerose Múltipla/tratamento farmacológico , Peptídeos/imunologia , Peptídeos/uso terapêutico , Adulto , Anticorpos/sangue , Citocinas/metabolismo , Progressão da Doença , Feminino , Fator de Transcrição GATA3/metabolismo , Acetato de Glatiramer , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/genética , Esclerose Múltipla/imunologia , Peptídeos/farmacologia
3.
Diabetes Res Clin Pract ; 89(1): 16-21, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20392509

RESUMO

AIMS: We evaluated the urinary orosomucoid excretion (UOE) as a biomarker of preeclampsia and preterm delivery in pregnant women with type 1 diabetes. METHODS: Singleton pregnant women with pregestational type 1 diabetes were included provided one urine sample had been collected before 17 gestational weeks. Serum and urinary orosomucoid were analysed by immunoturbidimetry. Primary outcome measurements were development of preeclampsia (blood pressure>140/90mmHg and proteinuria) and preterm delivery before 37 weeks. RESULTS: In total 173 women were included. The UOE increased during pregnancy. Preeclampsia developed in 20 women and 65 women delivered preterm. Using logistic regression analysis we found that UOE>1.37mg/l (OR: 6.85 (95% CI: 1.97-23.88; p<0.003)), nulliparity (3.88 (1.10-13.72); p<0.04), systolic blood pressure>120mmHg (4.12 (1.35-12.59); p<0.02) and duration of diabetes>20 years (3.69 (1.18-11.52); p<0.03) independently predicted the development of preeclampsia. Independent predictors of preterm delivery were duration of diabetes and HbA1c>7%. The remaining covariates included in the regression models were BMI, serum creatinine, smoking and microalbuminuria. CONCLUSIONS: Increased UOE early in pregnancy predicted preeclampsia in women with pregestational type 1 diabetes independently of albuminuria and other known risk factors. No association to preterm delivery was found.


Assuntos
Biomarcadores/urina , Diabetes Mellitus Tipo 1/urina , Diabetes Gestacional/urina , Orosomucoide/urina , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/urina , Adulto , Albuminúria/epidemiologia , Albuminúria/urina , Biomarcadores/sangue , Índice de Massa Corporal , Creatinina/sangue , Diabetes Gestacional/epidemiologia , Feminino , Humanos , Avaliação de Resultados em Cuidados de Saúde , Pré-Eclâmpsia/epidemiologia , Valor Preditivo dos Testes , Gravidez , Segundo Trimestre da Gravidez/urina , Nascimento Prematuro/diagnóstico , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/urina , Análise de Regressão , Fatores de Risco , Fumar/epidemiologia
4.
Tob Control ; 18(4): 283-93, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19528043

RESUMO

OBJECTIVES: Emergency department (ED) patients show high smoking rates. The effects of ED-initiated tobacco control (ETC) on 7-day abstinence at 12 months were investigated. METHODS: A randomised controlled intention-to-treat trial (trials registry no.: ISRCTN41527831) was conducted with 1044 patients in an urban ED. ETC consisted of on-site counselling plus up to four telephone booster sessions. Controls received usual care. Analysis was by logistic regression. RESULTS: In all, 630 (60.7%) participants were males, the median age was 30 years (range 18-81) and the median smoking intensity was 15 (range 1-60) cigarettes per day. Overall, 580 study participants (55.6%) were unmotivated, 331 (31.7%) were ambivalent and 133 (12.7%) were motivated smokers. ETC (median time 30 (range 1-99) min) was administered to 472 (91.7% out of 515) randomised study participants. At follow-up, 685 study participants (65.6% of 1044) could be contacted. In the ETC group, 73 out of 515 (14.2%) in the ETC group were abstinent, whereas 60 out of 529 (11.3%) controls were abstinent (OR adjusted for age and gender = 1.31 (95% CI 0.91 to 1.89, p = 0.15). Stratified for motivation to change behaviour, the adjusted ORs for ETC versus usual care were OR = 1.00 (95% CI 0.57 to 1.76) in unmotivated smokers, respectively OR = 1.37 (95% CI 0.73 to 2.58) in ambivalent smokers and OR = 2.19 (95% CI 0.98 to 4.89) in motivated smokers, p for trend = 0.29. CONCLUSIONS: ETC, in the form of on-site counselling with up to four telephone booster sessions, showed no overall effect on tobacco abstinence after 12 months. A non-significant trend for a better performance of ETC in more motivated smokers was observed.


Assuntos
Serviço Hospitalar de Emergência , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar , Adolescente , Adulto , Idoso , Aconselhamento/métodos , Feminino , Seguimentos , Alemanha , Hospitais Universitários , Linhas Diretas , Humanos , Análise de Intenção de Tratamento , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Motivação , Saúde da População Urbana/estatística & dados numéricos , Adulto Jovem
5.
Phys Chem Chem Phys ; 8(6): 777-82, 2006 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-16482319

RESUMO

The electrical photoconductivity and conductivity at (and near) the surface of a TiO(2) single crystal (rutile) was studied in a range of temperatures between 300 and 573 K and under different ambient gases (oxygen and nitrogen) by means of impedance spectroscopy. The long times required (many hours) to reach steady state photoconductivity can be explained by the reduction of the material upon illumination. At about 475 K a maximum is observed in the equilibrium photoconductivity and a minimum in the rate constants of the rise and decay after switching on and off, respectively, the light. After switching off the light a fast decay takes place during the first milliseconds followed by a slow exponential decay. The first one is related to recombination through defects, while the latter is due to re-oxidation processes of the material. The results are correlated with measurements of photocatalytic activity.


Assuntos
Nitrogênio/química , Oxigênio/química , Temperatura , Titânio/química , Cristalização , Condutividade Elétrica , Impedância Elétrica , Fotoquímica/instrumentação , Fotoquímica/métodos , Propriedades de Superfície , Fatores de Tempo
6.
Am J Physiol Renal Physiol ; 286(4): F774-83, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14644751

RESUMO

We recently showed that, in a proximal tubule cell line (opossum kidney cells), epithelial growth factor (EGF) stimulates basolateral organic anion transport (OAT) via ERK1/2, arachidonic acid, phospholipase A2, and generation of prostaglandins. PGE2 binds the prostanoid receptor and, thus, activates adenylate cyclase and PKA, which stimulate basolateral organic anion uptake. In the present study, we investigated whether this regulatory cascade is also true 1) for ex vivo conditions in isolated renal proximal (S2) tubules from rabbit and 2) in a human renal epithelial cell line stably expressing human OAT1 (IHKE-hOAT1). EGF activated ERK1/2 in S2 tubules and IHKE-hOAT1, and, in both cases, inhibition of ERK activation (by U-0126) abolished this stimulation. In S2 tubules and IHKE-hOAT1, EGF led to an increase of organic anion uptake, which again was inhibited by U-0126. PGE2 stimulated basolateral organic anion uptake in rabbit S2 tubules and IHKE-hOAT1. EGF- and PGE2-mediated stimulation of organic anion uptake was abolished by inhibition of PKA in rabbit S2 tubules and IHKE-hOAT1, respectively. We conclude that 1) stimulation of basolateral organic anion uptake by EGF or PGE2 is a widespread (if not general) regulatory mechanism, 2) the signal transduction pathway involved seems to be general, 3) stimulation of basolateral organic anion uptake by EGF or PGE2 is also present under ex vivo conditions and, thus, is not a cell culture artifact, 4) activation of OAT1 is sufficient to explain the stimulatory effects of EGF and PGE2 in opossum kidney cells and rabbit S2 segments, and 5) stimulation of basolateral OAT1 by EGF or PGE2 is also important in humans and, thus, may have clinical implications.


Assuntos
Dinoprostona/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Células Epiteliais/metabolismo , Túbulos Renais Proximais/metabolismo , Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Sulfonamidas , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Isoquinolinas/farmacologia , Túbulos Renais Proximais/citologia , Cinética , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Coelhos , Ácido p-Aminoipúrico/farmacocinética
7.
Eur J Biochem ; 268(2): 462-9, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11168383

RESUMO

The 5-kDa protein PorA of the Gram-positive bacterium Corynebacterium glutamicum is the subunit of the cell wall channel. Antibodies raised against PorA specifically detected the protein on the cell surface. PorA was sequenced using Edman degradation and a gas phase sequencer. The primary sequence was used to create degenerate oligonucleotide primers. The gene of the channel-forming protein and its flanking regions were obtained by PCR followed by inverse PCR. The gene porA comprises 138 bp and encodes a 45-amino-acid-long acidic polypeptide with an excess of four negatively charged amino acids in agreement with the high cation selectivity of the PorA cell wall channel. PorA does not contain an N-terminal extension. A ribosomal-binding site was recognized 6 bp before the start codon ATG of porA. It codes for the smallest subunit of a membrane channel known so far and for the first cell wall channel protein of a corynebacterium. Southern blots demonstrated that only the chromosomes of corynebacteria contain homologous sequences to porA; no hybridization could be detected with DNA from other mycolata.


Assuntos
Parede Celular/genética , Corynebacterium/genética , Porinas/genética , Sequência de Aminoácidos , Sequência de Bases , Transporte Biológico , Parede Celular/química , Clonagem Molecular , Genes Bacterianos , Ácido Glutâmico/biossíntese , Microbiologia Industrial , Dados de Sequência Molecular , Ácidos Micólicos , Reação em Cadeia da Polimerase , Porinas/isolamento & purificação , Análise de Sequência de DNA , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
8.
Int J Cancer ; 90(1): 29-36, 2000 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-10725855

RESUMO

Because of the uncertainties regarding the efficacy of postoperative radiation therapy for early prostate cancer, treatment strategies following radical prostatectomy include: (1) observation alone in high-risk patients, (2) adjuvant radiation therapy (PSA undetectable) in high-risk patients, or (3) salvage radiation therapy for biochemical and clinical recurrence. Fifty-two patients treated with postoperative radiation therapy in either an adjuvant setting (13) or for salvage (39) were retrospectively reviewed. The actuarial biochemical disease-free survival (bNED) rates following radiation therapy were calculated using the life-table method. Univariate and multi variate analyses were used to define the clinical factors that predict biochemical failure following postoperative radiation therapy. In addition, the bNED survival rate for 36 high-risk surgery patients who were simply observed following prostatectomy was determined. The 3-year bNED survival rate for the adjuvant radiation group was 85% compared with 27% for salvage radiation and 43% for the observation group. These results are statistically significant. Factors that predict biochemical failure following postoperative radiation therapy include preoperative PSA level, pre-radiation therapy PSA level, and seminal vesicle involvement. At our institutions, adjuvant radiation therapy was a superior strategy compared with either observation alone or salvage radiation therapy for high-risk postoperative prostate cancer patients. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 29-36 (2000).


Assuntos
Proteínas de Neoplasias/sangue , Recidiva Local de Neoplasia/sangue , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/radioterapia , Idoso , Análise de Variância , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Prostatectomia , Neoplasias da Próstata/cirurgia , Radioterapia Adjuvante , Análise de Regressão , Estudos Retrospectivos , Terapia de Salvação , Taxa de Sobrevida
9.
J Foot Ankle Surg ; 37(4): 292-302, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9710781

RESUMO

Proximal first metatarsal osteotomies have been criticized for their instability leading to the dorsal displacement of the first metatarsal head. The purpose of this study was to compare inherent stability of fixated proximal oblique wedge and crescentic first metatarsal osteotomies against simulated vertical ground reactive forces. The authors evaluated four groups of 10 models each with various proximal osteotomy and fixation configurations. Group I was a control group of bone models without osteotomies; group II had oblique closing wedge osteotomies with one 2.7-mm, fully threaded, cortical screw fixation; group III had oblique closing wedge osteotomies with two 2.7-mm, fully threaded, cortical screw fixation; and group IV had proximal crescentic osteotomies with one 4.0-mm, partially threaded, cancellous screw fixation. All 40 bone models were stressed with simulated vertical ground reactive forces. Maximum load to achieve catastrophic failure was higher in the crescentic group (67.7 N, SD 15.1 N, p < or = .005), but the energy required to displace the osteotomy during the stressing sequence was higher in the two-screw oblique closing wedge osteotomy (390.6 N.mm, SD 153.4 N.mm, p < or = .01). The single-screw oblique closing wedge osteotomies showed the least ability to resist simulated vertical ground reactive forces (39.6 N, SD 19.1 N, p < or = .005).


Assuntos
Hallux Valgus/cirurgia , Ossos do Metatarso/cirurgia , Osteotomia/métodos , Fenômenos Biomecânicos , Parafusos Ósseos , Cadáver , Humanos , Ossos do Metatarso/fisiopatologia , Modelos Estruturais , Osteotomia/efeitos adversos , Suporte de Carga
10.
Restor Neurol Neurosci ; 11(4): 211-23, 1997 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21551865

RESUMO

Traumatic injury to the adult human spinal cord most frequently occurs at the mid-to-low cervical segments and produces tetraplegia. To investigate treatments for improving upper extremity function after cervical spinal cord injury (SCI), three behavioral tests were examined for their potential usefulness in evaluating forelimb function in an adult rat model that mimics human low cervical SCI. Testing was conducted pre- and up to 4 weeks post-operation in adult female rats subjected to either contusion injury at the C7 spinal cord segment or sham-surgery. Modified Forelimb Tarlov scales revealed significant proximal and distal forelimb extension dysfunction in lesion rats at l-to-4 weeks post-cervical SCI. The Forelimb Grip Strength Test showed a significant decrease in forelimb grip strength of lesion rats throughout the 4 weeks post-cervical SCI. Significant deficits in reach and pellet retrieval by lesion rats were measured at l-to-4 weeks post-cervical SCI with the conditioned pellet retrieval Staircase Test. The results demonstrate that these qualitative and quantitative forelimb behavioral tests can be used to evaluate forelimb function following low cervical SCI and may be useful to investigate treatments for improving forelimb function in these lesions.

11.
Teratology ; 54(6): 278-83, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9098921

RESUMO

Oncoproteins are not only involved in the development of tumors but also play a role in physiological regulation in embryonic growth and differentiation. The mechanisms by which regulation is accomplished in embryonic stages differ from postnatal or adult stages. Oncoproteins responsible for tumors in the adult, i.e., products of proto-oncogenes, are prevented from causing tumors in the embryo. If oncogenes are introduced artificially into the embryo. will they be governed by the embryonic regulation described above? To answer this question we used transgenic mice in which the hybrid construct MSV-SV40-Large-T, composed of the Simian-Virus-Oncogene. Large-T with its SV40-promotor and the Moloney Murine Sarcoma Virus (MSV)-enhancer, had been integrated. Under the influence of large-T expression, these animals develop either brain or endocrine pancreas tumors. In the present investigation, we localised large-T expression during development of mouse embryos and fetuses. Interestingly, we saw large-T positive reactions in organ anlagen other than those that later develop tumors. We found large-T antigens in cartilage anlagen, e.g., in ribs and vertebrae, particularly in fetuses of days 14 to 17, and also in a variety of epithelial cells such as in the lung or the choroid plexus. Our results indicate that, as for proto-oncogene products, the effect of an artificially introduced transgenic oncogene product can also be regulated by embryonic cells.


Assuntos
Antígenos Transformantes de Poliomavirus/metabolismo , Desenvolvimento Embrionário e Fetal , Animais , Ductos Biliares/embriologia , Ductos Biliares/imunologia , Osso e Ossos/embriologia , Osso e Ossos/imunologia , Plexo Corióideo/embriologia , Plexo Corióideo/imunologia , Imuno-Histoquímica , Fígado/embriologia , Fígado/metabolismo , Pulmão/embriologia , Pulmão/imunologia , Camundongos , Camundongos Transgênicos , Músculos/embriologia , Músculos/imunologia , Pâncreas/embriologia , Pâncreas/imunologia
12.
Immunobiology ; 192(1-2): 1-9, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7750983

RESUMO

Hypochlorite and taurine chloramine (T-NCI) convert native fifth component of human complement (C5) to an activated state. This is evident from loss of functional properties of native C5 and acquisition of a binding site for C6 which is characteristic of C5b, the physiological activation fragment of C5. The complex of activated C5 with C6 is capable of combining with the components C7, C8, and C9 forming the cytotoxic terminal complement complex C5-9. The activation of C5 and its assembly with the late reacting complement components has been detected by reactive lysis, i.e. hemolysis of unsensitized red cells upon incubation with the activated C5 and the reacting complement components C6-C9. T-NCl does, however, not cleave any peptide bond in C5 as happens in the physiological activation process but converts the intact protein to the activated form. The conversion is accompanied and probably caused by oxidation of methionine residues in the C5 protein to methionine sulfoxide. Since hypochlorite and T-NCl are biological products generated by the myeloperoxidase-halide system of stimulated leukocytes, the activation of C5 by these agents may be one way to complement activation during inflammation and tissue injury.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Complemento C5/metabolismo , Ácido Hipocloroso/farmacologia , Peroxidase/metabolismo , Taurina/análogos & derivados , Eletroforese em Gel de Poliacrilamida , Humanos , Ácido Hipocloroso/metabolismo , Metionina/metabolismo , Neutrófilos/enzimologia , Oxirredução , Taurina/metabolismo , Taurina/farmacologia
13.
Biol Chem Hoppe Seyler ; 375(8): 513-20, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7529026

RESUMO

A new aspect of mammalian porin (mammalian VDAC = mammalian voltage-dependent anion channel) is presented: channel active VDAC binds adenosine triphosphate (ATP) in the absence of Ca2+. Channel active "Porin 31HL" or "Porin 31BM", enriched from crude membranes of human B lymphocytes or whole cell lysates of bovine skeletal muscle, respectively, was bound to a nine atoms spacer ATP-agarose at pH 7.4 or 5.0 and reeluted from the resin by 10 mM ATP disodium salt. Furthermore, channel active "Porin 31BM" was labelled by [32P]ATP in a 1:1 stoichiometric relation. Binding of ATP to human porin was confirmed by studying the interaction of the synthetic porin fragment Type-1/Ac-35, comprising the putative nucleotide binding site G Y G F G, with trinitrophenyl-ATP (TNT-ATP) by scanning fluorometry. Peptide/TNP-ATP complexes clearly show enhancement of fluorescence intensity and a spectral shift of the fluorescence maximum. In a control experiment, using a porin fragment lacking the putative nucleotide binding site, no change of fluorescence emission was observed. Further confirmation for ATP binding by human VDAC arose from an autoradiographic experimental approach: the porin fragment Type-1/Ac-35 could be labelled by [32P]ATP, while a second porin fragment ending immediately before the putative nucleotide binding site could not; nor could a synthetic non porin peptide.


Assuntos
Trifosfato de Adenosina/metabolismo , Linfócitos B/metabolismo , Proteínas de Membrana/metabolismo , Músculo Esquelético/metabolismo , Trifosfato de Adenosina/análogos & derivados , Sequência de Aminoácidos , Animais , Linfócitos B/citologia , Western Blotting , Bovinos , Cromatografia de Afinidade , Eletroforese em Gel de Poliacrilamida , Fluorometria , Humanos , Canais Iônicos , Proteínas de Membrana/química , Proteínas de Membrana/isolamento & purificação , Mitocôndrias , Dados de Sequência Molecular , Peso Molecular , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/isolamento & purificação , Proteínas do Tecido Nervoso/metabolismo , Fragmentos de Peptídeos , Porinas/química , Porinas/metabolismo , Ligação Proteica , Espectrometria de Fluorescência , Canal de Ânion 1 Dependente de Voltagem , Canais de Ânion Dependentes de Voltagem
14.
Biochem Med Metab Biol ; 52(2): 120-7, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7993658

RESUMO

Eight mouse monoclonal antibodies directed against the acetylated N-terminal part of the type 1 human VDAC Porin 31HL clearly discriminate type 1 and type 2 mammalian porin channels. This is shown by comparing synthetic N-terminal peptides of either channel type in Western dot blots or by ELISA. The data support the specificity of the anti-Porin 31HL antibodies and thus give further support to our recent observations on extramitochondrial expression of VDAC. In the plasmalemma of different mammalian cells VDAC forms part of an ubiquitous chloride channel complex, which in patch clamp measurements may figure as the outwardly rectifying depolarization-induced chloride channel that is affected in cystic fibrosis.


Assuntos
Anticorpos Monoclonais/imunologia , Porinas/análise , Sequência de Aminoácidos , Animais , Ensaio de Imunoadsorção Enzimática , Humanos , Immunoblotting , Camundongos , Dados de Sequência Molecular , Porinas/química , Porinas/imunologia
15.
Biol Chem Hoppe Seyler ; 375(5): 315-22, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8074805

RESUMO

Two new aspects of mammalian porin are presented. First, by affinity chromatography we show that channel active human or bovine porin reversibly bind the stilbene-disulfonate group of the chloride channel blocker 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS). The procedure is suitable for further purification of porin after enrichment by ion exchange chromatography and shows a yield of 24.3%. The data support our recent proposal that VDAC forms part of the ORDIC channel complex which is affected in cystic fibrosis. Second, a purification scheme for mammalian porin is given starting with direct solubilisation of ground bovine skeletal muscle to avoid breaking up tissue. About 130 mg of channel active "Porin 31BM" are enriched from 946 g muscle tissue. Concerning its apparent molecular mass, primary structure, channel activity, channel conductance and voltage dependence the molecule shows high similarity to human porin. "Porin 31BM" is furthermore labelled by antibodies raised against human B lymphocyte derived "Porin 31HL".


Assuntos
Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/metabolismo , Linfócitos B/química , Canais de Cloreto/metabolismo , Proteínas de Membrana/metabolismo , Músculos/química , Porinas , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Sequência de Aminoácidos , Animais , Western Blotting , Bovinos , Canais de Cloreto/química , Canais de Cloreto/efeitos dos fármacos , Canais de Cloreto/isolamento & purificação , Cromatografia de Afinidade , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Humanos , Bicamadas Lipídicas , Proteínas de Membrana/química , Proteínas de Membrana/isolamento & purificação , Dados de Sequência Molecular , Peso Molecular , Canal de Ânion 1 Dependente de Voltagem , Canais de Ânion Dependentes de Voltagem
16.
Mol Immunol ; 29(2): 251-6, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1542301

RESUMO

Purified human C5 was incubated with chloramine T (Cl-T) or N-chloro-succinimide (N-Cl-S) in barbital buffer, pH 7.2. The treatment led to C5 activation: Cl-T- and N-Cl-S-treated C5 acquired a binding site for C6; upon incubation with C6 and subsequent addition of C7, C8 and C9 a membrane attack complex formed which lysed non-sensitized guinea pig red cells (reactive lysis). While the physiological activation of C5 follows its specific cleavage, the resulting fragment C5b representing the activated C5 and expressing the C6 binding site, the treatment with the mentioned chemicals does not lead to fragmentation of the C5 protein. So, functionally, the product of the chemical treatment is C5b-like, but chemically, it comprises the whole protein; no C5a is released. Cl-T and N-Cl-S are known to more or less selectively oxidize methionine residues in proteins, dependent on the conditions. Other sensitive amino acid residues are tryptophan and cysteine. Conditions were chosen for treatment of C5 with Cl-T which exclude attack on tryptophan, and we have ensured that human C5 does not contain free cysteine residues. Further, oxidation of about 60% of the methionine residues of C5 by Cl-T was demonstrated by amino acid analysis. So, all evidence points to methionine residue(s) as the site of attack of Cl-T and probably also of N-Cl-S. The oxidation product of methionine, its sulphoxide, may cause a change in structural conformation of C5 which involves expression of the C6 binding site. Earlier it was found that oxidation of C5 by hydroxyl radicals leads to its activation without cleavage. Since the properties of this C5b-like product resemble those of the product of treatment with Cl-T and N-Cl-S, it is suggested that the formerly found activation of human C5 by hydroxyl radicals is also mediated by oxidation of methionine residue(s) in the C5 protein.


Assuntos
Ativação do Complemento , Complemento C5/química , Metionina/química , Compostos de Tosil , Cloraminas/química , Complexo de Ataque à Membrana do Sistema Complemento , Humanos , Oxirredução , Sensibilidade e Especificidade , Succinimidas/química
17.
Surgery ; 107(3): 321-6, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1968683

RESUMO

Glutamine and alanine are dominant nitrogen carriers from skeletal muscle stores to splanchnic organs. In addition, these amino acids may also serve as a primary energy source for the gastrointestinal tract during injury. To investigate these contributions, we studied extremity amino acid efflux during hypocaloric dextrose feedings and during total parenteral nutrition in a population of normal volunteers (NL VOL) (n = 9), a group of patients with sepsis who had undergone laparotomy without bowel resection and were in the intensive care unit (ICU) (n = 7), and patients with sepsis after laparotomy (PT) (n = 2) who had recently undergone greater than 80% bowel resection. Circulating alanine and glutamine levels were significantly lower in the patients compared with NL VOL under both feeding conditions. The peripheral output of alanine was higher in the ICU group than in the NL VOL during hypocaloric feedings. Glutamine efflux, however, was independent of either the counterregulatory hormone or substrate background. By contrast, enterectomy was associated with a marked decrease of extremity glutamine efflux compared with NL VOL or the ICU patients who did not undergo enterectomy (-62 +/- 9 nmol/min/dl tissue in the PT vs -265 +/- 32 nmol/min/dl tissue in the NL VOL and -311 +/- 58 nmol/min/dl tissue in the ICU group) during the dextrose feedings; this difference persisted during subsequent total parenteral nutrition (+12 +/- 13 nmol/min/dl tissue in PT vs -178 +/- 56 nmol/min/dl tissue in the NL VOL and -287 +/- 81 nmol/min/dl tissue in the ICU group). These data suggest that distinct mechanisms regulate peripheral alanine and glutamine balance and that the gastrointestinal tract provides a feedback signal to peripheral tissues to maintain glutamine mobilization under both nonstressed and stressed conditions.


Assuntos
Glutamina/metabolismo , Intestinos/cirurgia , Adulto , Idoso , Alanina/metabolismo , Glutamatos/metabolismo , Ácido Glutâmico , Humanos , Unidades de Terapia Intensiva , Mucosa Intestinal/metabolismo , Laparotomia , Pessoa de Meia-Idade , Nitrogênio/metabolismo
18.
J Exp Med ; 170(5): 1627-33, 1989 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-2809510

RESUMO

Cytokines secreted in response to invading micro-organisms are important mediators of detrimental hemodynamic and metabolic changes in the host. To test whether cachectin/TNF plays a role in triggering release of other cytokines in the setting of infection, anesthetized baboons were passively immunized against systemic cachectin/TNF before infusion of a LD100 dose of live Escherichia coli. Bacteremia led to significant increases in circulating levels of cachectin/TNF, IL-1 beta, and IL-6. Although bacterial endotoxin/lipopolysaccharide is a potent stimulus for the synthesis and release of IL-1 and IL-6 in vitro, specific neutralization of cachectin/TNF in vivo with mAb pretreatment significantly attenuated both the IL-1 beta and the IL-6 responses despite fulminant overwhelming bacteremia. These data suggest that cachectin/TNF is essential for the initiation or amplification of IL-1 and IL-6 release during lethal gram-negative septic shock syndrome.


Assuntos
Interleucina-1/metabolismo , Interleucina-6/metabolismo , Sepse/fisiopatologia , Choque Séptico/fisiopatologia , Fator de Necrose Tumoral alfa/fisiologia , Animais , Imunização Passiva , Papio , Sepse/sangue , Choque Séptico/sangue , Fator de Necrose Tumoral alfa/imunologia
19.
Ann Surg ; 210(2): 239-45, 1989 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2667476

RESUMO

Lipopolysaccharide (LPS, endotoxin) administration to human subjects elicits significant elevations in plasma cachectin/TNF, epinephrine, and cortisol. This study examined the temporal relationship between changes in blood leukocyte subsets and plasma mediators following endotoxin administration to normal human subjects. A five-minute intravenous infusion of purified LPS (20 units/kg Escherichia coli) was administered to 12 healthy volunteers. Blood samples were obtained at varying intervals after infusion and analyzed for differential cell counts and lymphocyte subsets (CD2, CD3, CD4, CD8, CD20, and HLA-DR) by flow microfluorimetry, and also assayed for plasma cachectin/TNF, epinephrine, and cortisol. Plasma cachectin/TNF was significantly elevated at 75 and 90 minutes after infusion with a peak concentration of 261 +/- 115 pg/ml noted 75 minutes after infusion. A significant plasma epinephrine elevation of 181 +/- 75 pg/ml was demonstrated one hour after infusion, while significant elevations in plasma cortisol were noted from one to five hours after infusion with a peak level of 34 +/- 3 micrograms/dl three hours after infusion. A profound monocytopenia (p less than 0.01) was noted one hour after infusion. Temporally associated with the rise in plasma cortisol was a reversal of the early granulocytopenia to a significant granulocytosis (p less than 0.01 versus preinfusion mean), whereas a marked lymphocytopenia (p less than 0.01) was observed from one to six hours after infusion. During the period of hypercortisolemia, CD2, CD3, and CD4 lymphocyte percentages were decreased (p less than 0.01) while CD20 and HLA-DR lymphocyte percentages were increased (p less than 0.01). There was a small percentage decrease in CD8 lymphocytes from one to 24 hours after infusion (p less than 0.01), although relative to the one-hour nadir, there was a significant rise in the percentage during the time of elevated plasma cortisol concentrations. A six-hour infusion of epinephrine (30 ng/kg/min) administered to six healthy volunteers resulted in a monocytosis (p less than 0.05) and granulocytosis (p less than 0.01) without a change in lymphocyte number or lymphocyte subset percentage. Previous reports have shown that in vivo corticosteroid infusion causes a prominent granulocytosis, monocytopenia, and lymphocytopenia with a decrease in the percentages of CD3 and CD4 lymphocytes. The peripheral blood leukocyte dynamics documented in the current study are similar to patterns observed following in vivo corticosteroid administration. This study suggests that the acute adrenocortical response to endotoxemia primarily mediates the subsequent changes in leukocyte subsets.


Assuntos
Leucócitos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Adulto , Antígenos de Diferenciação/análise , Separação Celular , Endotoxinas/farmacologia , Epinefrina/sangue , Epinefrina/farmacologia , Escherichia coli , Citometria de Fluxo , Antígenos HLA-DR/análise , Humanos , Hidrocortisona/sangue , Cinética , Contagem de Leucócitos/efeitos dos fármacos , Leucócitos/classificação , Leucócitos/imunologia , Fator de Necrose Tumoral alfa/análise
20.
Proc Natl Acad Sci U S A ; 86(9): 3371-4, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2497466

RESUMO

A potentially lethal complication of trauma, malignancy, and infection is a progressive erosion of muscle protein mass that is not readily reversed by nutritional support. Growth hormone is capable of improving total body nitrogen balance, but its role in myofibrillar protein synthesis in humans is unknown. The acute, in situ muscle protein response to an infusion of methionyl human growth hormone was investigated in the limbs of nutritionally depleted subjects during a period of intravenous refeeding. A 6-hr methionyl growth hormone infusion achieved steady-state serum levels comparable to normal physiologic peaks and was associated with a significant increase in limb amino acid uptake, without a change in body amino acid oxidation. Myosin heavy-chain mRNA levels, measured by quantitative dot blot hybridization, were also significantly elevated after growth hormone administration. The data indicate that methionyl growth hormone can induce intracellular amino acid accrual and increased levels of myofibrillar protein mRNA during hospitalized nutritional support and suggest growth hormone to be a potential therapy of lean body wasting.


Assuntos
Aminoácidos/metabolismo , Hormônio do Crescimento/análogos & derivados , Músculos/metabolismo , Miosinas/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/uso terapêutico , Inanição/terapia , Adulto , Hormônio do Crescimento/sangue , Hormônio do Crescimento/uso terapêutico , Hormônio do Crescimento Humano , Humanos , Insulina/sangue , Leucina/metabolismo , Masculino , Oxirredução , Nutrição Parenteral , Inanição/metabolismo
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