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1.
Handb Exp Pharmacol ; 270: 47-71, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34467427

RESUMO

Reduction of glucose is the hallmark of diabetes therapy proven to reduce micro- and macro-vascular risk in patients with type 1 diabetes. However glucose-lowering efficacy trials in type 2 diabetes didn't show major cardiovascular benefit. Then, a paradigm change in the treatment of patients with type 2 diabetes has emerged due to the introduction of new blood glucose-lowering agents. Cardiovascular endpoint studies have proven HbA1c-independent cardioprotective effects for GLP-1 receptor agonists and SGLT-2 inhibitors. Furthermore, SGLT-2 inhibitors reduce the risk for heart failure and chronic kidney disease. Mechanisms for these blood glucose independent drug target-related effects are still an enigma. Recent research has shown that GLP-1 receptor agonists might have anti-inflammatory and plaque stabilising effects whereas SGLT-2 inhibitors primarily reduce pre- and after-load of the heart and increase work load efficiency of the heart. In addition, reduction of intraglomerular pressure, improved energy supply chains and water regulation appear to be major mechanisms for renoprotection by SGLT-2 inhibitors. These studies and observations have led to recent changes in clinical recommendations and treatment guidelines for type 2 diabetes. In patients with high or very high cardio-renal risk, SGLT-2 inhibitors or GLP-1 receptor agonists have a preferred recommendation independent of baseline HbA1c levels due to cardioprotection. In patients with chronic heart failure, chronic kidney disease or at respective risks SGLT-2 inhibitors are the preferred choice. Therefore, the treatment paradigm of glucose control in diabetes has changed towards using diabetes drugs with evidence-based organ protection improving clinical prognosis.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Glicemia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Controle Glicêmico , Humanos , Hipoglicemiantes/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico
2.
J Chem Phys ; 153(4): 044123, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32752663

RESUMO

The emergence of machine learning methods in quantum chemistry provides new methods to revisit an old problem: Can the predictive accuracy of electronic structure calculations be decoupled from their numerical bottlenecks? Previous attempts to answer this question have, among other methods, given rise to semi-empirical quantum chemistry in minimal basis representation. We present an adaptation of the recently proposed SchNet for Orbitals (SchNOrb) deep convolutional neural network model [K. T. Schütt et al., Nat. Commun. 10, 5024 (2019)] for electronic wave functions in an optimized quasi-atomic minimal basis representation. For five organic molecules ranging from 5 to 13 heavy atoms, the model accurately predicts molecular orbital energies and wave functions and provides access to derived properties for chemical bonding analysis. Particularly for larger molecules, the model outperforms the original atomic-orbital-based SchNOrb method in terms of accuracy and scaling. We conclude by discussing the future potential of this approach in quantum chemical workflows.

3.
Nat Commun ; 10(1): 5024, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729373

RESUMO

Machine learning advances chemistry and materials science by enabling large-scale exploration of chemical space based on quantum chemical calculations. While these models supply fast and accurate predictions of atomistic chemical properties, they do not explicitly capture the electronic degrees of freedom of a molecule, which limits their applicability for reactive chemistry and chemical analysis. Here we present a deep learning framework for the prediction of the quantum mechanical wavefunction in a local basis of atomic orbitals from which all other ground-state properties can be derived. This approach retains full access to the electronic structure via the wavefunction at force-field-like efficiency and captures quantum mechanics in an analytically differentiable representation. On several examples, we demonstrate that this opens promising avenues to perform inverse design of molecular structures for targeting electronic property optimisation and a clear path towards increased synergy of machine learning and quantum chemistry.

4.
Herz ; 44(3): 203-209, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30847507

RESUMO

Diabetes mellitus is an important comorbidity in patients with heart failure. The presence of heart failure in diabetes worsens the prognosis of patients. Recent studies suggest that appropriate diagnostic approaches followed by differential medical treatment are of crucial importance to improve patient outcomes. This article summarizes important aspects of the association between diabetes mellitus and heart failure.


Assuntos
Complicações do Diabetes , Diabetes Mellitus , Insuficiência Cardíaca , Comorbidade , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/prevenção & controle , Humanos , Prognóstico
5.
J Chem Theory Comput ; 15(1): 448-455, 2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30481453

RESUMO

SchNetPack is a toolbox for the development and application of deep neural networks that predict potential energy surfaces and other quantum-chemical properties of molecules and materials. It contains basic building blocks of atomistic neural networks, manages their training, and provides simple access to common benchmark datasets. This allows for an easy implementation and evaluation of new models. For now, SchNetPack includes implementations of (weighted) atom-centered symmetry functions and the deep tensor neural network SchNet, as well as ready-to-use scripts that allow one to train these models on molecule and material datasets. Based on the PyTorch deep learning framework, SchNetPack allows one to efficiently apply the neural networks to large datasets with millions of reference calculations, as well as parallelize the model across multiple GPUs. Finally, SchNetPack provides an interface to the Atomic Simulation Environment in order to make trained models easily accessible to researchers that are not yet familiar with neural networks.

6.
J Chem Phys ; 148(24): 241722, 2018 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-29960322

RESUMO

Deep learning has led to a paradigm shift in artificial intelligence, including web, text, and image search, speech recognition, as well as bioinformatics, with growing impact in chemical physics. Machine learning, in general, and deep learning, in particular, are ideally suitable for representing quantum-mechanical interactions, enabling us to model nonlinear potential-energy surfaces or enhancing the exploration of chemical compound space. Here we present the deep learning architecture SchNet that is specifically designed to model atomistic systems by making use of continuous-filter convolutional layers. We demonstrate the capabilities of SchNet by accurately predicting a range of properties across chemical space for molecules and materials, where our model learns chemically plausible embeddings of atom types across the periodic table. Finally, we employ SchNet to predict potential-energy surfaces and energy-conserving force fields for molecular dynamics simulations of small molecules and perform an exemplary study on the quantum-mechanical properties of C20-fullerene that would have been infeasible with regular ab initio molecular dynamics.

7.
Br J Anaesth ; 120(5): 978-987, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29661415

RESUMO

BACKGROUND: Idarucizumab is licensed to reverse dabigatran in life-threatening haemorrhage. Establishment of venous access can be challenging, and the intraosseous (IO) route is a potentially life-saving alternative. In this study, we compared the efficacy and safety of IO or intravenous (i.v.) idarucizumab for dabigatran reversal in a porcine polytrauma model. METHODS: Male pigs (n=21) received oral dabigatran etexilate (30 mg kg-1 bid) for 3 days. On the 4th day, animals received dabigatran infusion and were randomised 1:1:1 to receive IO saline (control), i.v. idarucizumab (60 mg kg-1), or IO idarucizumab (60 mg kg-1), or animals were included in a sham group (n=7). Study treatment was administered after polytrauma and the animals were monitored for 240 min, or until death. Coagulation status was monitored by thromboelastometry, thromboelastography, and thrombin measurements. RESULTS: Total blood loss was lowest in sham animals [521 (52) ml, P<0.01 vs all other groups], and comparable in the two idarucizumab groups [IO: 1085 (102) ml vs i.v.: 1142 (125) ml], and highest in the control group [4065 (557) ml, P<0.001 vs all other groups]. Survival to 240 min was 100% in the sham group and both idarucizumab groups, and 14% in the control group. IO and i.v. idarucizumab promptly normalised global coagulation assays and thrombin generation. Thromboelastography showed a strong correlation between dabigatran concentrations and R-time (R2=0.90 and 0.89) in idarucizumab-treated animals. CONCLUSIONS: Intravenous and intraosseous idarucizumab were comparable for reversing dabigatran in a porcine trauma model. Dabigatran reversal could be monitored using fully automated thromboelastography.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Dabigatrana/antagonistas & inibidores , Hemorragia/tratamento farmacológico , Traumatismo Múltiplo , Administração Intravenosa , Animais , Anticorpos Monoclonais Humanizados/administração & dosagem , Antitrombinas , Modelos Animais de Doenças , Infusões Intraósseas , Masculino , Suínos
8.
Herz ; 42(3): 329-340, 2017 May.
Artigo em Alemão | MEDLINE | ID: mdl-28396903

RESUMO

Patients with diabetes mellitus exhibit an increased risk for the development of heart failure. The occurrence of heart failure in patients with diabetes is associated with a poor prognosis. Therapeutic strategies to reduce cardiovascular morbidity and mortality in diabetes have so far mainly focused on the prevention of coronary events but recent data suggest that an early diagnosis of heart failure in diabetes as well as specific therapies could have a major impact on the prognosis for these patients. This article aims to provide a comprehensive overview on the epidemiology, pathophysiology and prognosis of heart failure in diabetes patients and addresses current aspects of heart failure therapy in diabetes as well as diabetes therapy in heart failure patients.


Assuntos
Cardiomiopatias Diabéticas/mortalidade , Cardiomiopatias Diabéticas/terapia , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/terapia , Hipoglicemiantes/uso terapêutico , Comorbidade , Medicina Baseada em Evidências , Humanos , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento
9.
Anim Genet ; 43(4): 442-6, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22497268

RESUMO

Polymorphisms located in the genes ABCG2, DGAT1, LEP, PRLR, RORC, CAPN1 and CAST previously have been associated with milk or meat production traits. In this study, these polymorphisms were examined for significant effects on reproductive traits [age at puberty (AGECL), post-partum anoestrus interval (PPAI) and the ability ovulate prior to weaning (PW)] and on a panel of correlated traits such as weight, growth and serum concentration of insulin-like growth factor I. The effects of the polymorphisms were examined in two samples of tropically adapted beef cattle: Brahman (N = 932) and Tropical Composites (N = 1097). A polymorphism in the gene DGAT1 was associated with age at puberty in the combined sample (P = 0.042), and two polymorphisms in CAPN1 were associated with PPAI (P = 0.033) and with the ability ovulate PW (P = 0.017). The favourable allele for reproductive traits was not always the favourable allele associated with production traits. The effects of these polymorphisms on reproductive traits were small compared to their effects on the traits for which they were originally discovered.


Assuntos
Bovinos/genética , Carne , Leite , Polimorfismo de Nucleotídeo Único , Reprodução/genética , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Alelos , Animais , Calpaína/genética , Calpaína/metabolismo , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Feminino , Marcadores Genéticos , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Músculo Esquelético/metabolismo , Fenótipo , Desmame , Aumento de Peso
10.
Zentralbl Gynakol ; 123(1): 37-41, 2001 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-11385910

RESUMO

The diagnosis of a lethal anomaly of the fetus can affect a pregnant woman in a traumatic way. Almost immediately she has to decide whether she wishes the pregnancy to be terminated or not. Literature shows that such a loss is very difficult to cope with, and can lead to social isolation and depression. Contrary to popular belief the loss felt by the woman is at least the same to that following a stillbirth. Problems arise when the woman has difficulties in expressing her feelings, has a lack of self-esteem or receives very little social support. The prenatal diagnosis evokes an acute grief reaction. Only few studies are available regarding length, course and severity of grief in this case. Although an abortion through a fetal anomaly is a traumatic experience, research is vague on the trauma caused. Present day research of the psychological sequelae after the termination will be summarized. In respect to the current trauma-research lies the question of which psychiatric conditions arise from such a traumatic experience.


Assuntos
Aborto Induzido/psicologia , Anormalidades Congênitas/embriologia , Pesar , Diagnóstico Pré-Natal/psicologia , Anormalidades Congênitas/diagnóstico , Feminino , Humanos , Gravidez
11.
Basic Res Cardiol ; 93 Suppl 1: 66-75, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9833133

RESUMO

UNLABELLED: End-stage failing human myocardium is characterized by a negative force-frequency relationship (FFR), possibly as a result of reduced SR Ca2+ uptake capacity. We investigated the effects of the direct adenylate cyclase stimulator, forskolin, on force of contraction and FFR in isolated human myocardium from 7 nonfailing hearts (NF) and end-stage failing hearts (NYHA IV) due to either ischemic (ICM; n = 13) or dilated cardiomyopathy (DCM; n = 16). METHODS: Isolated left ventricular muscle strips, isometric contraction, electrical stimulation at a basal stimulation rate of 1 Hz (37 degrees C). Inotropic responses: Cumulative concentration-response curves for forskolin (0.01-10 microM) and for Ca2+ (2.5-15 mM). Force-frequency experiments: stepwise increase in stimulation rate from 0.5 to 3.0 Hz without and in the presence of 0.3, 1.0 or 3.0 microM forskolin. RESULTS: Forskolin concentration-dependently increased force of contraction to 386 +/- 28% (n = 5) in NF, to 256 +/- 48% (n = 7) in ICM, and to 212 +/- 13% (n = 14) in DCM. The effectiveness of forskolin was significantly reduced in failing myocardium. Ca2+ increased force of contraction to maximally 438 +/- 108% in NF, to 267 +/- 15% in ICM, and to 292 +/- 20% in DCM. Again, the effectiveness of Ca2+ was significantly reduced in failing myocardium. Forskolin activated contractile reserve to similar extents in all types of myocardium (90%, 95%, and 82%, respectively). Force of contraction continuously increased with increasing stimulation rates in nonfailing myocardium (positive FFR), but was blunted or inversed in ICM and DCM. Prestimulation with forskolin (0.3 microM) further enhanced frequency-potentiation in nonfailing, and normalized the slope and optimum stimulation frequency in ICM and DCM. However, at higher concentrations of forskolin, FFR was blunted or inversed in non-failing myocardium, and further impaired in failing myocardium. CONCLUSION: Low concentrations of forskolin with only marginal inotropic effects may partially normalize the inverse force-frequency relation in end-stage failing human myocardium. Reduced cAMP levels in conjunction with reduced expression of SR Ca2+ ATPase may be the underlying cause for altered excitation-contraction coupling in diseased human hearts.


Assuntos
Cardiomiopatia Dilatada/tratamento farmacológico , Cardiotônicos/farmacologia , Colforsina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , Isquemia Miocárdica/tratamento farmacológico , Fenômenos Biomecânicos , Cálcio/metabolismo , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/patologia , Avaliação Pré-Clínica de Medicamentos , Estimulação Elétrica , Humanos , Técnicas In Vitro , Contração Isométrica/efeitos dos fármacos , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Valores de Referência
12.
Infusionsther Transfusionsmed ; 23(1): 25-8, 1996 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-8653012

RESUMO

OBJECTIVE: Collecting of data for immunoprophylaxis of tetanus in immunodeficient patients via administration of blood products. DESIGN: Prospective single case studies. SETTING: Clinical therapy in a department of hematology with continuous determination of tetanus antibody concentrations in patients' sera and administered blood products with an enzyme immunoassay. PATIENTS: 3 patients with acute myeloid leukemia (FAB classifications M1, M3, M4). INTERVENTIONS: Regular administration of blood products due to clinical therapy. RESULTS: After administration of about 4,000 IU tetanus antitoxin i.v., serum concentration is increasing by 1 IU/ml. Half life in serum amounts to 7 days. Protection lasts therefore up to 6 weeks. CONCLUSIONS: Immunodeficient patients may receive a medium-term effective protection against tetanus after selection of suitable blood products. This method is interesting also for prophylaxis of postoperative tetanus in immunocompetent patients.


Assuntos
Anticorpos Antibacterianos/sangue , Transfusão de Componentes Sanguíneos , Clostridium tetani/imunologia , Infecções Oportunistas/imunologia , Tétano/imunologia , Feminino , Humanos , Técnicas Imunoenzimáticas , Leucemia Mieloide Aguda/imunologia , Masculino , Pessoa de Meia-Idade , Infecções Oportunistas/prevenção & controle , Estudos Prospectivos , Tétano/prevenção & controle , Antitoxina Tetânica/administração & dosagem , Antitoxina Tetânica/imunologia
13.
Gesundheitswesen ; 55(7): 364-6, 1993 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-8369604

RESUMO

In newborn and their mothers a considerable lack of immunity to tetanus was found. Values of corresponding serum pairs differed in part; some children were unprotected in spite of maternal immunity. Pregnant women without protection should therefore be vaccinated twice before delivery. Over and above this, good hygienic standards in obstetrics must be maintained.


Assuntos
Anticorpos Antibacterianos/análise , Clostridium tetani/imunologia , Imunidade Materno-Adquirida/imunologia , Tétano/imunologia , Feminino , Humanos , Esquemas de Imunização , Recém-Nascido , Gravidez , Tétano/prevenção & controle , Toxoide Tetânico/administração & dosagem , Toxoide Tetânico/imunologia
14.
Offentl Gesundheitswes ; 53(6): 269-72, 1991 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-1833694

RESUMO

Immunity to tetanus in the population of Rhine-Hesse deteriorates with increasing age. A reduction of both the average antibody concentration and the duration of immunity after the last vaccination can be found. The percentage of unprotected people also increases with age. Especially women have a poor protection against tetanus. The immunity to tetanus should therefore be checked in elderly persons and in women irrespective of a possible lesion.


Assuntos
Toxoide Tetânico/imunologia , Tétano/imunologia , Adolescente , Adulto , Idoso , Feminino , Alemanha , Humanos , Imunidade Ativa/imunologia , Esquemas de Imunização , Masculino , Pessoa de Meia-Idade , Tétano/prevenção & controle , Toxoide Tetânico/administração & dosagem
15.
J Gen Virol ; 72 ( Pt 1): 143-7, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1703559

RESUMO

C57BL/6 mice, which differ genetically from other strains by their resistance to herpes simplex virus type 1 (HSV-1) infection, were inoculated intraperitoneally with different doses of tumour necrosis factor alpha (TNF-alpha). Mice pretreated with 100 ng, or even 10 ng, of TNF-alpha showed prolonged survival compared to control mice that were infected with 10(7) p.f.u. of HSV-1. Significant protection was observed in mice injected 4 or 8 h prior to or after HSV-1 inoculation, respectively. Protection was also observed when mice which differed at their H-2 locus were treated with TNF-alpha after infection with HSV-1. Interferon could not be detected in the sera of mice at different time points after infection with HSV-1 or injection of TNF-alpha and there was no enhanced interferon titre in mice treated with both TNF-alpha and HSV-I, suggesting some interferon-independent protection. However, mice treated with TNF-alpha showed a marked activation of natural killer (NK) cells compared to untreated control mice or mice that were treated with HSV-1 alone. To test whether enhanced NK cell activity is responsible for TNF-alpha-induced protection, mice were injected with the NK cell-specific antibody anti-asialo Gm-1. In this experimental protocol the survival rate was almost unaffected, indicating that the observed protection was not due to activation of NK cells and that TNF-alpha is involved in the regulation of antiviral mechanisms other than the activation of interferons. Although additional production of interferon induced by TNF-alpha cannot be excluded, an antiviral effect of TNF-alpha on the course of HSV-1 infection may be postulated from our data.


Assuntos
Herpes Simples/imunologia , Fator de Necrose Tumoral alfa/uso terapêutico , Animais , Linhagem Celular , Citotoxicidade Imunológica , Herpes Simples/prevenção & controle , Interferons/análise , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Proteínas Recombinantes/uso terapêutico , Simplexvirus/isolamento & purificação , Fatores de Tempo
16.
Infusionstherapie ; 17(3): 156-9, 1990 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-2391173

RESUMO

The application of antibodies to tetanus toxin is necessary for prevention of postoperative tetanus in patients at risk, e.g. in emergency surgery. However, intravenous preparations with sufficiently rapid distribution throughout the body are not available. This could only be achieved via the blood products (whole blood unit, fresh frozen plasma, thrombocyte concentrate) transfused in such cases. For semiquantitative determination of antibody concentration in blood products, an ELISA assay was developed, which can be used as a screening method for selection of sera with high titers. The assay is quick and easy to perform so that large numbers of sera can be tested within a short time.


Assuntos
Anticorpos Antibacterianos/análise , Transfusão de Sangue , Ensaio de Imunoadsorção Enzimática , Complicações Pós-Operatórias/prevenção & controle , Toxoide Tetânico/imunologia , Tétano/prevenção & controle , Adulto , Anticorpos Antibacterianos/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tétano/imunologia
17.
J Immunol ; 144(3): 970-5, 1990 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-2295823

RESUMO

Human PBMC from HIV-1-infected individuals produced ex vivo in response to vesicular stomatitis virus only low amounts of IFN-alpha. This impairment was significant as early as Walter Reed (WR) stage 2; at WR stage 4-5, the production was almost zero. At WR stage 2 of infection, IFN-alpha mRNA was exclusively found in association with polyribosomes, indicating that IFN-alpha gene was transcriptionally inactive under the experimental conditions used. A similar decrease of the level of transcripts as a function of the progression of the disease was also observed for the IFN-gamma mRNA. In contrast, TNF-alpha production was strongly enhanced in PBMC from HIV-1-infected individuals after stimulation with LPS compared to the TNF-alpha production of activated PBMC from healthy donors. Almost parallel with the increase of the level of the transcript for TNF-alpha, the level of TNF-beta increases as well. Data are presented which show that the increased TNF-alpha production is due to a longer half-life of TNF-alpha transcripts in PBMC from infected individuals. These results let us suggest that the up-regulation of TNF-alpha gene expression in PBMC from HIV-infected individuals is controlled predominantly on the posttranscriptional level, whereas transcriptional events regulate the level of IFN-alpha transcripts. This assumption is supported by run-on experiments which revealed that the extent of transcription of TNF-alpha gene is almost identical in nuclei from stimulated PBMC of noninfected and HIV-infected donors, whereas the transcription of IFN-alpha gene is strongly suppressed in nuclei from HIV-infected individuals at WR stages 3 and 6.


Assuntos
Complexo Relacionado com a AIDS/genética , Síndrome da Imunodeficiência Adquirida/genética , Interferon Tipo I/genética , Leucócitos Mononucleares/fisiologia , Fator de Necrose Tumoral alfa/genética , Northern Blotting , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Lipopolissacarídeos/farmacologia , RNA Mensageiro/genética , Acetato de Tetradecanoilforbol/farmacologia , Transcrição Gênica
18.
J Exp Med ; 170(3): 797-810, 1989 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-2788708

RESUMO

From the peripheral blood of the melanoma patient (AV), we derived cytolytic T lymphocyte (CTL) clones that lysed the autologous tumor line SK-MEL-29, but not autologous EBV-B cells, K562, and other tumor targets. By immunoselection experiments it was shown that the CTL clones recognized at least three different antigens on the autologous tumor cells. We demonstrate here that these melanoma antigens are presented to the CTL in association with HLA-A2. First, HLA-A2-reactive pregnancy sera as well as an mAb against HLA-A2 inhibited the CTL lysis. Second, immunoselected melanoma subclones that were resistant to lysis by CTL clones against the three antigens described were found to lack expression of HLA-A2. By sensitizing the patient's lymphocytes against an HLA-A2- melanoma clone, we established a new series of CTL clones recognizing autologous AV melanoma cells. However, efficient lysis was only seen when target cells were pretreated with IFN-gamma. The lytic activity of these CTL was selectively inhibited by an mAb against a common HLA-B determinant. These results indicate that in addition to HLA-A2, other class I antigens are involved in the recognition of AV melanoma cells by autologous CTL.


Assuntos
Antígenos de Neoplasias/análise , Citotoxicidade Imunológica , Antígenos HLA-A/fisiologia , Melanoma/imunologia , Linfócitos T Citotóxicos/imunologia , Adulto , Anticorpos Monoclonais/imunologia , Células Clonais , Antígenos HLA-A/imunologia , Antígeno HLA-A2 , Humanos , Soros Imunes/imunologia , Masculino
19.
Klin Wochenschr ; 66 Suppl 15: 15-22, 1988.
Artigo em Alemão | MEDLINE | ID: mdl-3141675

RESUMO

The risk of transmitting infectious agents through homologous blood transfusions can't be completely eliminated. According to our present knowledge, the posttransfusion-hepatitis (PTH) type B has been overestimated till the end of the seventies. Concerning PTH type Non A Non B special serological diagnostic techniques are missing, but nevertheless, there are indications as well that the frequency of this transfusion side-effect is overrated. The occurrence of HIV-transmission through blood-transfusions is right now considered to be 1:10(6) to 1: (3 X 10(6)). Because of continuous improvement of the analysing methods, these results seem to be reasonable and are similar to those we found. To determine the influence of transfusions on the defense mechanism of tumor-patients further investigations are necessary, because the immunosuppressive effect of the individual blood components has to be rated differently.


Assuntos
Síndrome da Imunodeficiência Adquirida/transmissão , Hepatite B/transmissão , Hepatite C/transmissão , Hepatite Viral Humana/transmissão , Reação Transfusional , Transfusão de Eritrócitos , Humanos , Fatores de Risco
20.
J Virol Methods ; 17(1-2): 95-103, 1987 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3312270

RESUMO

An enzyme-immunoassay (EIA) for antibodies to hepatitis B core antigen (anti-HBc) was developed. The new test uses undiluted samples, incubated directly into an HBcAg coated well. Three alternative test procedures are possible. The stability of reagents was studied and a preclinical evaluation was performed intramurally. An assay correlation study was organised. We report the results of the external evaluation performed at 4 centres. A mean analytical sensitivity of 1.1, 1.2 and 0.36 PEI units/ml anti-HBc was found for procedure I (1 h/1 h/30 min), procedure II (30 min/30 min/30 min) and procedure III (16-20 h/1 h/30 min), respectively. In total, 5288 determinations on serum or plasma from various patients and healthy individuals were performed: 10% with procedure I, 52% with procedure II and 38% with procedure III. The qualitative (positive or negative) results were compared with those found with tests used routinely at the centres--47% with Corzyme (Abbott) and 53% with Corab (Abbott)--in a first screening. A final evaluation was made taking into account the repeatability of the results. Based on all results together, the agreement between the new EIA for anti-HBc and the routine tests was 97.6% at the first screening and increased to 99.0% after further evaluation.


Assuntos
Anticorpos Anti-Hepatite B/análise , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Técnicas Imunoenzimáticas , Doadores de Sangue , Hepatite B/diagnóstico , Hepatite B/imunologia , Humanos , Valor Preditivo dos Testes
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