RESUMO
The mammalian growth factor receptor-binding protein Grb2 is an adaptor that mediates activation of guanine nucleotide exchange on Ras. Grb2 binds to the receptor through its SH2 domain and to the carboxyl-terminal domain of Son of sevenless through its two SH3 domains. It is thus a key element in the signal transduction pathway. The crystal structure of Grb2 was determined to 3.1 angstrom resolution. The asymmetric unit is composed of an embedded dimer. The interlaced junctions between the SH2 and SH3 domains bring the two adjacent faces of the SH3 domains in van der Waals contact but leave room for the binding of proline-rich peptides.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Receptores ErbB , Proteínas/química , Sequência de Aminoácidos , Sítios de Ligação , Gráficos por Computador , Cristalização , Cristalografia por Raios X , Receptores ErbB/metabolismo , Proteína Adaptadora GRB2 , Ligação de Hidrogênio , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Estrutura Secundária de Proteína , Proteínas/metabolismoRESUMO
OBJECTIVE: The increasing resistance of Helicobacter pylori to clarithromycin led to developing new eradication treatment regimens. The objective of our observational study was to determine the proportion of H. pylori strains resistant to clarithromycin in infected patients in Reunion Island and to suggest a first-line treatment in agreement with the local ecology. PATIENTS AND METHODS: We included 200 patients who underwent esophagogastroduodenoscopy at the University Hospital of Saint-Pierre from February to July 2014. H. pylori was isolated from 73 patients. RESULTS: A wild-type susceptibility profile to clarithromycin was observed in 64 isolates (87.7%) and nine isolates (12.3%) had a resistant mutation profile. CONCLUSION: With a proportion of resistant strains below the critical threshold of 15%, physicians in Reunion Island may continue to prescribe the usual treatment regimen as a first-line option (clarithromycin, amoxicillin, and proton pump inhibitor for 14 days).
Assuntos
Antibacterianos/uso terapêutico , Claritromicina/farmacologia , Dispepsia/epidemiologia , Gastrite Atrófica/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/efeitos dos fármacos , Adenocarcinoma/epidemiologia , Adenocarcinoma/microbiologia , Amoxicilina/uso terapêutico , DNA Bacteriano/genética , Resistência Microbiana a Medicamentos/genética , Quimioterapia Combinada , Dispepsia/etiologia , Fundo Gástrico/microbiologia , Gastrite Atrófica/tratamento farmacológico , Gastrite Atrófica/epidemiologia , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Metaplasia , Mutação , Inibidores da Bomba de Prótons/uso terapêutico , Antro Pilórico/microbiologia , Reunião/epidemiologia , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/microbiologiaRESUMO
Ultraviolet difference spectroscopy was used to study the interaction of peanut (Arachis hypogaea) lectin with complementary carbohydrates. A correlation was observed between variations of ultraviolet spectra during the binding of sugars to the lectin and the specificity and the strength of the binding. The association constant, free energy, enthalpy and entropy for peanut lectin-lactose interactions were calculated over the temperature range 10-30 degrees C. The binding constants for 10 mono- and disaccharides containing a D-galactopyranosyl or a D-talopyranosyl residue were calculated. Comparing their effectiveness to interact with peanut lectin, methyl alpha-D-galactopyranoside appeared to have a more marked affinity than lactose; D-galacturonic acid and methyl 7-deoxy-D-glycero-beta-D-galacto-heptopyranoside had no measurable affinity; the other sugars showed a lower affinity than lactose. The correlations between these differences and the conformations of the sugars obtained by X-ray analysis are discussed.
Assuntos
Dissacarídeos , Lectinas , Monossacarídeos , Sítios de Ligação , Fenômenos Químicos , Química , Lactose , Aglutinina de Amendoim , Espectrofotometria UltravioletaRESUMO
Microbial HTS has been implemented at Rhône-Poulenc Rorer through the development of a dedicated robotic platform. This robot (Turbo) has been designed with the aim of fully integrating microbial HTS into the lead discovery processes. Innovative solutions have been found to reach high throughput as well as flexibility. This opens up new prospects for solid-phase microbial screening, taking advantage of the easy implementation and the very low costs of such screens. The different types of microbial screens done in our laboratory, as well as the throughputs and outputs obtained, are described. Some of the specific aspects of microbial HTS, as compared to biochemical and cell-based assays, are also discussed.
Assuntos
Avaliação Pré-Clínica de Medicamentos/instrumentação , Avaliação Pré-Clínica de Medicamentos/métodos , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/métodos , Bactérias/efeitos dos fármacos , Bactérias/genética , Estudos de Avaliação como Assunto , Genes Reporter , Robótica , Técnicas do Sistema de Duplo-HíbridoRESUMO
The fate of 31 children (18 boys, 13 girls) whose Wolff-Parkinson-White syndrome (WPW) had been diagnosed before they were 2 years' old (mean 3.4 months) was investigated. The circumstances in which WPW was discovered were: evaluation of a heart disease in 9 cases, attack of orthodromic tachycardia in 16 cases (including one with cardiopathy), and routine electrocardiography in 6 cases. Type A WPW was the most frequent, being found in 20 patients of whom only 3 had a heart disease; type B WPW was present in 11 patients, and 7 of these had a heart disease. Mean follow-up was 5.9 years; 3 children died of other causes than WPW. In patients followed up for more than one year WPW disappeared in 65 p. 100 of the cases (11/17) in the absence of cardiopathy, and in only 14 p. 100 of the cases (1/7) in the presence of cardiopathy. In children who had suffered attacks of tachycardia WPW disappeared in 64 p. 100 of the cases (9/14). When WPW disappeared it was before the age of 1 year in 8 out of 12 cases. Only one child whose WPW had disappeared had further attacks of tachycardia (11 p. 100), while 3 children whose WPW persisted had short and widely spaced attacks (60 p. 100). This study confirms the high rate of spontaneous disappearance of WPW and the excellent prognosis of this syndrome in the absence of heart disease.
Assuntos
Síndrome de Wolff-Parkinson-White , Eletrocardiografia , Feminino , Seguimentos , Cardiopatias Congênitas/complicações , Humanos , Lactente , Masculino , Prognóstico , Taquicardia/etiologia , Síndrome de Wolff-Parkinson-White/diagnóstico , Síndrome de Wolff-Parkinson-White/etiologia , Síndrome de Wolff-Parkinson-White/fisiopatologiaRESUMO
The authors propose a therapeutic strategy enabling diagnosis, treatment and prevention in the same clinical procedure based on a series of 8 patients presenting with signs of massive pulmonary embolism (acute cardiorespiratory distress, shock, loss of consciousness, and/or cardiac arrest). A removable vena cava filter is rapidly introduced percutaneously via a brachial, femoral or jugular vein, and opened in the inferior vena cava. Using the same catheter and without a second venous puncture, pulmonary angiography and cavography are performed by digitised angiography using a small quantity of contrast medium (40 ml, 12 ml/sec). The diagnosis of massive pulmonary embolism (index of pulmonary obstruction 70 to 90%) was confirmed in 6 out of the 8 cases. In 2 patients, the contrast medium passed from the right atrium into the left atrium and one of the patients developed hemiplegia. Thrombolytic drugs (rt-PA followed by Streptokinase) were injected via the same filter catheter. The dosage of rt-PA was 20 to 50 mg as a bolus followed by 50 mg in 2 hours. Streptokinase was then infused at a dose of 100,000 U/hour for an average of 36 hours (24-48 hours), followed by intravenous heparin and oral vitamin K antagonists. Two patients required blood transfusion for haemorrhage during the relay with heparin. The temporary caval filter was removed in all cases but 3 patients required a definitive filter because of the persistence of life-threatening venous thrombosis. Seven of the 8 patients survived their pulmonary embolism. This approach is rapid, saves time, and spares the patients from more invasive procedures.
Assuntos
Embolia Pulmonar/terapia , Terapia Trombolítica/métodos , Filtros de Veia Cava , Idoso , Idoso de 80 Anos ou mais , Angiografia Digital , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/prevenção & controle , Estreptoquinase/uso terapêutico , Ativador de Plasminogênio Tecidual/uso terapêuticoRESUMO
Rheumatoid valvular heart disease and aortic valve replacement for a rheumatoid lesion have been previously reported in the literature. The authors report the first case of emergency surgery for acute aortic regurgitation due to necrosis and rupture of a rheumatoid granuloma: the anatomopathological lesions observed were patholognomic.
Assuntos
Insuficiência da Valva Aórtica/cirurgia , Artrite Reumatoide/complicações , Próteses Valvulares Cardíacas , Cardiopatia Reumática/cirurgia , Adulto , Valva Aórtica , Insuficiência da Valva Aórtica/diagnóstico por imagem , Insuficiência da Valva Aórtica/etiologia , Insuficiência da Valva Aórtica/patologia , Ecocardiografia Doppler , Emergências , Feminino , Humanos , Cardiopatia Reumática/diagnóstico por imagem , Cardiopatia Reumática/patologiaRESUMO
The aims of this paper were to assess resistance of Helicobacter pylori to antibiotics included in the so-called French triple regimens and to identify the possible causes of therapeutic failure in Reunion island. Antibiotic resistance was determined for 109 strains. All the strains were sensitive to amoxicillin and tetracycline, 93.6% were sensitive to ciprofloxacin, 92.7% to erythromycin and 60.6% to metronidazole. Fifty three patients who had previously tested positive for H. pylori received for one week regimen of amoxicillin (1 g bd), clarithromycin (0.5 g bd) and omeprazole (20 mg bd). Eradication rate after therapy was of 73.6%. Therapeutic failure was analysed for 9 patients using random amplified polymorphic DNA and the presence or not of antibiotic resistance. One cause of failure is clarithromycin resistance. These data show that triple therapy can be used in Reunion Island. In case of failure, sensitivity must be detected because the rate of resistance to metronidazole is over 30%.
Assuntos
Antibacterianos/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Úlcera Gástrica/microbiologia , Amoxicilina/uso terapêutico , Antiulcerosos/uso terapêutico , Distribuição de Qui-Quadrado , Ciprofloxacina/uso terapêutico , Claritromicina/uso terapêutico , Intervalos de Confiança , DNA Bacteriano/análise , Farmacorresistência Bacteriana/genética , Eritromicina/uso terapêutico , Feminino , Helicobacter pylori/genética , Humanos , Masculino , Metronidazol/uso terapêutico , Pessoa de Meia-Idade , Omeprazol/uso terapêutico , Penicilinas/uso terapêutico , Técnica de Amplificação ao Acaso de DNA Polimórfico , Reunião , Úlcera Gástrica/tratamento farmacológico , Tetraciclina/uso terapêutico , Falha de TratamentoRESUMO
The number of people travelling of the tropical countries is in constant progression and today represents about 5% of the population of the developed countries. Mortality is mainly accidental. Morbidity essentially concerns transmissible diseases. Diarrhoeal symptoms occur in 20-55% of travellers, are bacterial in 2 cases out of 3, and can be prevented. Cholera should soon have an efficient oral vaccine. Hepatitis A is frequent in some travellers (2-3%) and can be prevented by vaccination. Hepatitis E is beginning to be observed. Strongyloidiasis can in some cases evolve to serious complications; it may be latent, so should be sought systematically after any visit to the tropics. Most affections on returning to the industrialised world concern paludism of the Plasmodium falciparum type, leading to a still high mortality rate of 400 per year in Europe, while the preventive and curative means available are sufficient. Any fever should therefore be suspected and suitable treatment given. Other causes of fever are acute viral hepatitis, typhoid fever, the arboviroses, and numerous other conditions. Dermatoses represent the third reason for consultation on returning. These mainly concern pruriginous symptoms with filariases and abnormal hosts being evidenced. Furunculous lesions indicate a diagnosis of cutaneous leishmaniosis or myases. Any form of pruritus should suggest a diagnosis of HIV infection, or pruritus should suggest a diagnosis of HIV infection, or particularly trypanosomiasis. The risk of sexually transmissible disease is overall 6-fold higher in tropical travellers; advice before travelling is therefore of paramount importance. Should a seropositive subject travel to the tropics?(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Doenças Transmissíveis/epidemiologia , Viagem , Clima Tropical , Adulto , Diarreia/epidemiologia , Feminino , França/epidemiologia , Hepatite/epidemiologia , Humanos , Enteropatias Parasitárias/epidemiologia , Malária/epidemiologia , Masculino , Infecções Sexualmente Transmissíveis/epidemiologia , Dermatopatias/epidemiologiaRESUMO
We are reporting a case of malignant pheochromocytoma surgically treated initially for an isolated left pararenal localization, and which recurred several years later accompanied with numerous metastases. Despite of a treatment with Iodine 131 MIBG, the evolution was rapidly fatal with a picture of cardiac failure. This cardiac involvement would be linked to a myocarditis directly secondary to the catecholamines and causing a marked increase of the free fatty acids concentration in the heart tissue. In reference to this case, all the data which may tend to suspect the malignant nature of a pheochromocytoma, present in 10 p. cent of the cases, are successively reviewed. There is no clinical specificity. The presence of a mixed secretion with marked urinary dopamine secretion, would not present, for all authors, the same criteria of specificity. Thoraco-abdominal scan and scintigraphy with iodine 131 MIBG are the two tests permitting to demonstrate, with a great sensitivity and specificity, an extra-adrenal localization, which is the best argument in favor of a malignancy since 30 to 40 p. cent of extra-adrenal pheochromocytomas are malignant, more especially as the metastases are located in areas where there are no embryonic remnants of tissues containing chromaffin cells. This permits to appreciate the difference between a non-malignant multicentric pheochromocytoma and a malignant pheochromocytoma. The ideal treatment of a malignant pheochromocytoma rests on surgery under the condition that there are ony one or two metastases. This procedure is preceded by a sodium nitroprusside preparation and followed with an alpha-blockers treatment. In case of multiple metastases, the therapeutic use of iodine 131 MIBG seems to be a tempting alternative.
Assuntos
Neoplasias das Glândulas Suprarrenais/patologia , Neoplasias Ósseas/secundário , Neoplasias Renais/secundário , Neoplasias Pulmonares/secundário , Feocromocitoma/secundário , Neoplasias das Glândulas Suprarrenais/complicações , Humanos , Hipertensão/etiologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Feocromocitoma/complicaçõesRESUMO
A new case of heart involvement in Lyme's disease is reported. Its originality lies in its strictly isolated nature, therefore revealing the disease; in its typical picture of myocardopericarditis combining, in various stages, infra-hissian conduction disorders, bouts of left ventricular insufficiency, pseudoischemic repolarisation disorders and finally a moderate pericardial shift; in the demonstration, during two successive heart explorations by NMR (Nuclear Magnetic Resonance), of a diffuse myocardial hypertrophy, subsiding in time, as the other symptoms of this patient.
Assuntos
Cardiopatias/etiologia , Doença de Lyme/complicações , Adolescente , Arritmias Cardíacas/etiologia , Cardiomiopatia Dilatada/etiologia , Humanos , Masculino , Derrame Pericárdico/etiologiaRESUMO
We have designed stable pKD1 derivatives for efficient secretion of recombinant human serum albumin (rHSA) by industrial strains of Kluyveromyces yeasts. A comparison of this multi-copy expression system with isogenic cassettes integrated at chromosomal loci demonstrated that high level secretion of rHSA is a function of gene dosage in K. lactis. Various signal sequences could be used, and the secretion levels were independent of the presence of the native pro peptide. The mitotic stability of the pKD1-based expression vectors was found to be species and strain dependent and was influenced by promoter strength and culture conditions. Vector stability was drastically enhanced when the HSA gene was expressed from an inducible promoter: 90% of the transformed cells still harbored the vector after 100 generations of non-selective growth in uninduced culture conditions. Secretion levels in the range of several grams per liter of correctly folded and processed rHSA were obtained at the pilot scale, thus making the industrial production of pharmaceutical-grade, Kluyveromyces-derived rHSA economically feasible.
Assuntos
Kluyveromyces/genética , Albumina Sérica/genética , Sequência de Bases , Biotecnologia/métodos , Códon/genética , Fermentação , Expressão Gênica , Vetores Genéticos , Humanos , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Proteínas Recombinantes/biossíntese , Mapeamento por Restrição , Albumina Sérica/biossínteseRESUMO
A high-productivity process has been developed for the production of mature human interleukin-1 beta (IL-1 beta) from recombinant Escherichia coli strains. Conditions were found that allow high IL-1 beta expression levels in high cell density cultures. Improved fed-batch fermentation strategies are described which include maintenance of glucose and acetate concentrations below 1 g/l and sparging the fermentor with an O2-enriched air supply. Using the E. coli tryptophan promoter control of transcription, a 2.2 g/l production level of IL-1 beta was achieved in E. coli B at cell densities of 55 g dry weight per litre. Another genetic construction involving the bacteriophage lambda cIts-PR expression cassette allowed a similar IL-1 beta production level (1.9 g/l) in E. coli E103S, albeit at a lower cell density (30 g/l). A simplified procedure allowing the purification of fully active IL-1 beta is also presented.
Assuntos
Escherichia coli/metabolismo , Interleucina-1/biossíntese , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Fermentação , Humanos , Interleucina-1/genética , Interleucina-1/isolamento & purificação , Plasmídeos , Regiões Promotoras Genéticas , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificaçãoRESUMO
Right coronary artery occlusion by a thrombus occurred during the coronary angiography performed in a patient with anterior myocardial infarction. Emergency coronary aspiration was undertaken via a 9F guiding catheter, which allowed the thrombus to be removed. The patient, who was in cardiogenic shock, immediately improved and was subsequently discharged without any complications or sequelae.
Assuntos
Doença das Coronárias/terapia , Trombose Coronária/terapia , Sucção/métodos , Angiografia , Angioplastia com Balão/instrumentação , Angiografia Coronária , Trombose Coronária/complicações , Emergências , Humanos , Masculino , Pessoa de Meia-Idade , Choque Cardiogênico/etiologiaRESUMO
The authors present a removable vena cava filter that may be introduced percutaneously, is atraumatic to the venous wall, and permits the simultaneous use of thrombolytic therapy. Sixty-five patients were studied: 42 cases of pulmonary embolism with threatening venous thrombosis; 23 cases of phlebitis associated with an ilio-caval thrombus without pulmonary embolism. The filter was introduced 38 times femorally and 27 times by a jugular approach. In 16 cases (24.6%) clots broke loose, were effectively caught by the filter, and were progressively dissolved during thrombolytic therapy. The filter remained in place on average 4.5 +/- 1.2 days. The filter was removed in all cases without provoking the recurrence of pulmonary embolism. Two deaths, not related to pulmonary embolism, occurred during hospitalization. Phlebography, performed in all cases before and after treatment, showed a significant decrease of the phlebographic score (10.88 +/- 0.82 vs 6.77 +/- 0.86, P less than 0.001). The same was observed in 40 patients who underwent a pulmonary angiography before and after treatment (Miller index = 17.04 +/- 0.73 vs 5.49 +/- 0.87, P less than 0.0001). After removal of the filter, no sign of pulmonary embolism was detected on lung scan in the 23 patients with ilio-caval thrombus alone. More than 5 g (100 ml)-1 of haemoglobin was lost by 15.38% of patients. All patients were followed-up for a mean of 7.12 +/- 1.3 months; in no case was there any clinical recurrence of pulmonary embolism. Thus this device allows an effective temporary filtering of the vena cava.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Filtros Microporos , Embolia Pulmonar/terapia , Veias Cavas , Cateteres de Demora , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Flebografia , Artéria Pulmonar/diagnóstico por imagem , Embolia Pulmonar/diagnóstico por imagem , Embolia Pulmonar/tratamento farmacológico , Recidiva , Estreptoquinase/uso terapêutico , Terapia Trombolítica/efeitos adversos , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tipo Uroquinase/uso terapêuticoRESUMO
The conformity of two recombinant proteins (a von Willbrand factor fragment and human serum albumin, consisting of respectively 289 and 585 amino acids) has been examined by HPLC combined with mass spectrometry and microsequencing, on both intact material and fragment peptides obtained by proteolytic cleavage. These studies confirmed that the primary structure of the recombinant proteins corresponds to that predicted from their gene, particularly the integrity of their N and C termini, and, in the case of albumin, the agreement between the observed disulfide bond pattern and the published model. Furthermore, the structure of an albumin-related compound could be elucidated. Application of LC-MS for batch-to-batch quality control is also under discussion.
Assuntos
Proteínas Recombinantes/análise , Sequência de Aminoácidos , Fenômenos Químicos , Físico-Química , Cromatografia Líquida de Alta Pressão , Brometo de Cianogênio , Humanos , Hidrólise , Espectrometria de Massas , Dados de Sequência Molecular , Peso Molecular , Análise de Sequência , Serina Endopeptidases , Albumina Sérica/análise , Tripsina , Fator de von Willebrand/análiseRESUMO
Due to its remarkably long half-life, together with its wide in vivo distribution and its lack of enzymatic or immunological functions, human serum albumin (HSA) represents an optimal carrier for therapeutic peptides/proteins aimed at interacting with cellular or molecular components of the vascular and interstitial compartments. As an example, we designed a genetically engineered HSA-CD4 hybrid aimed at specifically blocking the entry of the human immunodeficiency virus into CD4+ cells. In contrast with CD4, HSA-CD4 is correctly processed and efficiently secreted by Kluyveromyces yeasts. In addition, its CD4 moiety exhibits binding and antiviral in vitro properties similar to those of soluble CD4. Finally, the elimination half-life of HSA-CD4 in a rabbit experimental model is comparable to that of control HSA and 140-fold higher than that of soluble CD4. These results indicate that the genetic fusion of bioactive peptides to HSA is a plausible approach toward the design and recovery of secreted therapeutic HSA derivatives with appropriate pharmacokinetic properties.
Assuntos
Antígenos CD4/metabolismo , Proteínas Recombinantes de Fusão/farmacocinética , Albumina Sérica/farmacocinética , Animais , Anticorpos Monoclonais/imunologia , Sequência de Bases , Ligação Competitiva , Antígenos CD4/química , Vetores Genéticos , HIV/crescimento & desenvolvimento , HIV/metabolismo , Kluyveromyces/genética , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/química , Coelhos , Receptores Virais/química , Receptores Virais/metabolismo , Albumina Sérica/química , Solubilidade , Replicação ViralRESUMO
We report here the purification and the crystallization of the modular protein Grb2. The protein was expressed as a fusion with glutathione-S-transferase and purified by affinity chromatography on glutathione agarose. It was apparent from reverse phase chromatography that the purified protein was conformationally unstable. Instability was overcome by the addition of 100 mM arginine to the buffers. Because Grb2 appeared to be extremely sensitive to oxidation, crystallization experiments were performed with a dialysis button technique involving daily addition of fresh DTT to the reservoirs. The presence of 8 to 14% glycerol was necessary to obtain monocrystals. These results are discussed in relation with the modular nature of Grb2.