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1.
Pulmonology ; 29 Suppl 4: S36-S43, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34544672

RESUMEN

BACKGROUND: Tuberculosis (TB) incidence declined in Portugal in recent decades, but trends differ between regions and population subgroups. We investigated these differences to inform prevention and control programmes. METHODS: We extracted TB notifications from the Portuguese National TB Surveillance System (SVIG-TB) in 2010-2017, disaggregated by region, age group, nationality and HIV status. We calculated notification rates using denominators from the Portuguese National Institute of Statistics and the Joint United Nations Programme on HIV/AIDS and performed stratified time series analysis. We estimated interannual decline percentages and 95% confidence intervals (CI) using Poisson and binomial negative regression models. RESULTS: The overall TB notification rate decreased from 25.7 to 17.5/100,000 population from 2010 to 2017 (5.2%/year) in Portugal. Interannual decline did not differ significantly between regions, but it was smaller amongst non-Portuguese nationals (-1.57% [CI: -4.79%, 1.75%] vs -5.85% [CI: -6.98%, -4.70%] in Portuguese nationals); children under five years of age (+1.77% [CI: -4.61%, 8.58%] vs -5.38% [CI: -6.33%, -4.42%] in other age groups); and HIV-negative people (-6.47% [CI: -9.10%, -3.77%] vs -11.29% [CI; -17.51%, -4.60%] in HIV-positive). CONCLUSIONS: The decline in TB notification rates in Portugal during the study period has been steady. However, the decline amongst non-Portuguese nationals, children under five years of age and non-infected-HIV patients was lower. No significant differences were observed between regions. Changes in TB epidemiology in specific risk groups and geographical areas should be closely monitored to achieve the objectives of the End TB Strategy. We recommend intensifying screening of TB in the subpopulations identified.


Asunto(s)
Infecciones por VIH , Tuberculosis , Niño , Humanos , Preescolar , Portugal/epidemiología , Infecciones por VIH/epidemiología , Tuberculosis/epidemiología , Tuberculosis/diagnóstico , Factores de Riesgo , Incidencia
2.
Diabetes Metab Syndr Obes ; 13: 991-1004, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32280255

RESUMEN

BACKGROUND: Diabetes mellitus is a syndrome with multiple etiologies involving insulin, in which there is a lack of production and/or loss of sensitivity to this hormone resulting in insulin resistance. Treatment and control of this disease requires changes in diet, use of medication, and lifestyle, such as physical activity. These modifications may compromise quality-of-life if there is no proper guidance for the treatment or alert to possible complications caused by the disease. METHODS: This study aimed to evaluate biochemical and hematological parameters, and to assess brain derived neurotrophic factor levels in diabetic Wistar rats submitted to chronic physical exercise. RESULTS: The results demonstrated an increase in plasma concentration of brain-derived neurotrophic factor (BDNF) in association with hyperglycemia reduction in diabetic animals. DISCUSSION: The results obtained suggest that there is a regulation of glucose homeostasis between peripheral tissues and the central nervous system. Exercise-induced BDNF also improved levels of glycemia, body weight, and dyslipidemia. In hematological evaluation, BDNF increase was positively correlated with an improvement in leukocyte parameters. Electrophoresis analyses demonstrated a reduction in levels of pro-inflammatory proteins, lipoprotein fractions, and albumin preservation in diabetic animals trained with elevated concentration of plasma BDNF. CONCLUSION: In conclusion, this study demonstrated that chronic exercise was able to elevate BDNF levels in plasma, which resulted directly in positive hypoglycemic activity in diabetic animals and a reduction of the metabolic syndrome associated with diabetes mellitus.

3.
Viral Immunol ; 6(3): 219-28, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-7507329

RESUMEN

Monoclonal antibodies (MAbs) were produced against foot-and-mouth disease (FMD) virus types O1 Campos Br1/58, A24 Cruzeiro Br1/55, and C3 Indaial Br1/71, which are the strains used for production of FMD vaccines in the majority of South American countries. Within the library of MAbs produced, a group was selected on the basis of their neutralizing titer in cell culture, protective titer in suckling mice, sensitivity to trypsin, and specificity for virus structural proteins. The MAbs were utilized in an ELISA test format to compare European and South American representative field isolates with vaccine production strains in their r1 relationship as obtained by 50% complement fixation (CF50) with polyclonal antibodies (PAb) and their virus neutralization (VN) relationship obtained with sera from one-time-vaccinated and from revaccinated cattle, respectively. The MAbs selected varied in their reactivity against the different strains and, therefore, enabled us to compare field FMDV strains to those against which the MAbs were produced, with definite advantages over the r1 and VN ratios. Thus, panels of MAb produced with the vaccine strains and appropriately selected are significantly useful for the FMD-control programs because they serve to provide guidance on the immunological coverage provided by the vaccines against FMDV strains circulating in the field. The MAbs are also useful for the differentiation of FMD virus strains.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Aphthovirus/inmunología , Animales , Bovinos , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática/veterinaria , Epítopos , Fiebre Aftosa/inmunología , Fiebre Aftosa/prevención & control , Ratones , Ratones Endogámicos BALB C , Fenotipo , Vacunas Virales/inmunología
4.
Neuropeptides ; 26(4): 281-7, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7913210

RESUMEN

A series of biologically active peptides and related compounds (opioid peptides, neurotensin, and bradykinin) were used as substrates or competitive inhibitors to study the structural requirements for peptide interaction with endopeptidase 22.19. The kinetics of hydrolysis of these peptides indicated that, in contrast to other proteases, the substrate specificity of endopeptidase 22.19 is not determined by the amino acids flanking the sensitive bonds of the substrates. The competition between bioactive peptide analogues and the quenched fluorescence substrate of endopeptidase 22.19 indicated that their length and their flexibility may be the dominant factors to explain their binding specificities. These peculiar features of endopeptidase 22.19 may be of importance to understand the physiological processes of conversion and inactivation of biologically active peptides.


Asunto(s)
Metaloendopeptidasas/metabolismo , Neuropéptidos/química , Neuropéptidos/metabolismo , Secuencia de Aminoácidos , Animales , Bradiquinina/análogos & derivados , Bradiquinina/química , Bradiquinina/metabolismo , Encéfalo/enzimología , Dinorfinas/análogos & derivados , Dinorfinas/química , Dinorfinas/metabolismo , Metaloendopeptidasas/antagonistas & inhibidores , Datos de Secuencia Molecular , Neuropéptidos/farmacología , Oligopéptidos/química , Oligopéptidos/metabolismo , Conejos , Relación Estructura-Actividad , Especificidad por Sustrato , beta-Lipotropina/análogos & derivados , beta-Lipotropina/química , beta-Lipotropina/metabolismo
5.
Braz J Infect Dis ; 5(1): 13-20, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11290310

RESUMEN

Pneumonia is one of the leading causes of hospitalization and death among children in developing countries, and mortality due to pneumonia has been associated with S. pneumoniae infection. This investigation was designed to describe the antimicrobial susceptibility and serotype patterns of pneumococcal strains recovered from the blood of children with community-acquired pneumonia (CAP) and to assess the clinical findings of pneumococcal bacteremic patients with pneumonia. In a 26 month prospective study, blood cultures were obtained as often as possible from children (<16 years of age) diagnosed with CAP in two emergency rooms. Antimicrobial drug susceptibility tests and serotyping were performed when pneumococcus was identified. We studied 3,431 cases and cultured blood samples from 65.5% of those. Pneumococcus was recovered from 0.8% of the blood samples. The differences in age, somnolence, wheezing and hospitalization among children with and without pneumococcal bacteremia were statistically significant. Pneumococcal bacteremia was age-related (mean 1.63 +/- 1.55; median 0.92) and associated with somnolence and hospitalization among children with CAP. One strain was recovered from pleural fluid. Penicillin resistance was detected in 21.0% (4/19) of the strains at an intermediate level, whereas 63.0% of the strains were resistant to trimethoprim-sulfamethoxazole. The most common serotypes were 14 and 6B, and these serotypes included the resistant strains. Eight of our 18 isolates from blood were of types included in the heptavalent conjugate pneumococcal vaccine, recently licensed in the USA.


Asunto(s)
Infecciones Neumocócicas/microbiología , Streptococcus pneumoniae/efectos de los fármacos , Adolescente , Factores de Edad , Antibacterianos/farmacología , Bacteriemia/sangre , Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología , Brasil , Niño , Preescolar , Infecciones Comunitarias Adquiridas/sangre , Farmacorresistencia Microbiana , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Pruebas de Sensibilidad Microbiana , Infecciones Neumocócicas/sangre , Infecciones Neumocócicas/tratamiento farmacológico , Neumonía Neumocócica/sangre , Neumonía Neumocócica/tratamiento farmacológico , Neumonía Neumocócica/microbiología , Estudios Prospectivos , Serotipificación , Streptococcus pneumoniae/clasificación
6.
Arq Neuropsiquiatr ; 58(2A): 221-6, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10849618

RESUMEN

OBJECTIVE: The main aim of this study was to evaluate the knowledge, management practices and attitudes towards people with epilepsy (PWE) by a group of general practitioners (GP) and pediatrician (PD) residents. METHODS: A cross-sectional study was carried out in three training hospitals, and had been selected 31 GP and 47 PD who agreed with the study. The collection of data was made by self-applied structured questionnaire. RESULTS: Many respondents have positive values about PWE, and recognize prejudice in the population against them. The residents recognize in themselves and in the colleagues lack of knowledge about PWE, and that Medical School do not give enough importance to the study of PWE. The reference of PWE to the neurologist is a common practice among the doctors. Half of them are favorable to the idea of assuming the patients clinical management after an initial clientele appraisal by the neurologist. CONCLUSIONS: The non-neurologist doctors do not feel comfortable in managing PWE due to barriers. Our doctors complain about the undergraduate medical training related to the epilepsy. Although, there is not a clear relationship between the undergraduate medical training, referral practices and satisfaction about the management of PWE. The patients care is influenced not only by knowledge, but also by doctors' attitudes. In this way, there are other barriers, perceived or not, to providing care to PWE by the generalists, and they need to be approached in the medical undergraduate curriculum and medical continuing education.


Asunto(s)
Actitud del Personal de Salud , Epilepsia/terapia , Pediatría , Médicos de Familia , Pautas de la Práctica en Medicina/normas , Intervalos de Confianza , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Internado y Residencia , Masculino , Encuestas y Cuestionarios
7.
Arq Neuropsiquiatr ; 58(2A): 227-32, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10849619

RESUMEN

INTRODUCTION: People with epilepsy (PWE) may have problems in obtaining or maintaining regular employment because of restrictions related to their handicap, social prejudices and also high rates of unemployment of the population. The main aim of this pilot study was to know the vocational rehabilitation problems involving PWE sent to a vocational rehabilitation center (VRC) in Rio de Janeiro. METHOD: Fifteen PWE were selected unbiased from those seen at the VCR. It was reviewed their records in the search of sociodemographic, health care, employment suitability and work rehabilitation data. RESULTS: Only one person was eligible for the training program, four were ineligible, six were temporarily ineligible, and the other four do not necessitate the rehabilitation, but as the majority, the better seizures control. CONCLUSIONS: The studied sample of selected PWE, but representative of the studied population, do not show any important successful in the vocational rehabilitation carried out at the VRC.


Asunto(s)
Epilepsia/rehabilitación , Centros de Rehabilitación , Rehabilitación Vocacional , Adulto , Brasil , Escolaridad , Epilepsia/economía , Femenino , Humanos , Seguro por Discapacidad , Masculino , Estado Civil , Persona de Mediana Edad , Proyectos Piloto
8.
Arq Neuropsiquiatr ; 40(3): 296-300, 1982 Sep.
Artículo en Portugués | MEDLINE | ID: mdl-7159261

RESUMEN

The case of a 46 year-old man who had a locked-in syndrome is reported. The patient had a haemorragic vascular accident with tetraplegia, anartria, vertical ocular movements and preservation of the consciousness. The EEG showed a projected disturbance possibly caused by a brain-stem lesion, that was confirmed by the CAT SCAN. Cerebral angiography showed high level of aterosclerosis. The lesion is located in the ventral part of the pons above the nucleus of the abducent nerve, without damaging the substantia reticularis of the mesencephalon and can be caused by thrombosis of the basilar artery and tumor, myastenia gravis, polyneurites, heroin overdose, after swine-flu inoculation and post-infectious polyneurites. The patient is still alive 2 years after the stroke with a good recovery. He can walk and speak fluently, but with cordonal ataxy of the limbs.


Asunto(s)
Trastornos Cerebrovasculares/complicaciones , Cuadriplejía/etiología , Trastornos Cerebrovasculares/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
9.
Rev Assoc Med Bras (1992) ; 60(1): 47-52, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24918852

RESUMEN

OBJECTIVE: To investigate the relationship between physical activity level and sexual function in middle-aged women. METHODS: A cross-sectional study with a sample of 370 middle-aged women (40-65 years old), treated at public health care facilities in a Brazilian city. A questionnaire was used containing enquiries on sociodemographic, clinical and behavioral characteristics: the International Physical Activity Questionnaire (IPAQ), short form, and the Female Sexual Function Index (FSFI). RESULTS: The average age of the women studied was 49.8 years (± 8.1), 67% of whom exhibited sexual dysfunction (FSFI ≤ 26.55). Sedentary women had a higher prevalence (78.9%) of sexual dysfunction when compared to active (57.6%) and moderately active (66.7%) females (p = 0.002). Physically active women obtained higher score in all FSFI domains (desire, arousal, lubrication, orgasm, satisfaction and pain) and total FSFI score (20.9), indicating better sexual function than their moderately active (18.8) and sedentary (15.6) counterparts (p <0.05). CONCLUSION: Physical activity appears to influence sexual function positively in middle-aged women.


Asunto(s)
Actividad Motora , Disfunciones Sexuales Fisiológicas/psicología , Sexualidad/psicología , Adulto , Anciano , Animales , Estudios Transversales , Escolaridad , Femenino , Humanos , Menopausia/fisiología , Persona de Mediana Edad , Conducta Sedentaria , Encuestas y Cuestionarios
10.
Fundam Clin Pharmacol ; 24(3): 341-50, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19682086

RESUMEN

Various essential oils are rich in carvacrol, a monoterpenic phenol isomeric with thymol. This study was undertaken to assess the vasorelaxant effects of thymol and carvacrol in rat isolated aorta and the putative mechanisms underlying these effects. Thymol and carvacrol produced a concentration-dependent relaxation on the aortic ring preparations pre-contracted using KCl (IC(50) value of 64.40 +/- 4.41 and 78.80 +/- 11.91 microm, respectively) or using phenylephrine (PHE, 0.1 microm) (IC(50) value of 106.40 +/- 11.37 and 145.40 +/- 6.07 microm, respectively) and inhibited the concentration-response curves of aortic rings to PHE or KCl. In Ca(2+)-free medium with ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (2 mm), thymol and carvacrol both at 1000 microm completely abolished the phasic component of PHE-induced endothelium-containing ring contractions. At 400 microm, thymol and carvacrol significantly reduced the CaCl(2)-induced contractions in Ca(2+)-free medium. Furthermore, both thymol and carvacrol (300 and 1000 microm) significantly reduced the contraction evoked by phorbol dibutyrate (1 microm), an activator of protein kinase C. Magnitude of this inhibitory effect was enhanced in the presence of the Ca2+ pump inhibitor, thapsigargin (1 microm). At 1000 microm, neither thymol nor carvacrol altered the resting potential of vascular smooth muscle cells. In conclusion, thymol and carvacrol induced an endothelium-independent relaxation in rat isolated aorta, an effect that seems mediated through some mechanisms probably involving a transduction pathway between Ca(2+) release from sarcoplasmic reticulum and/or regulation of the Ca2+ sensitivity of the contractile system. Moreover, it's conceivable that thymol and carvacrol, at low concentrations, block the Ca(2+) influx through the membrane.


Asunto(s)
Aorta Torácica/efectos de los fármacos , Monoterpenos/farmacología , Músculo Liso Vascular/efectos de los fármacos , Timol/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Animales , Aorta Torácica/fisiología , Cimenos , Esquema de Medicación , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiología , Masculino , Monoterpenos/química , Músculo Liso Vascular/fisiología , Técnicas de Cultivo de Órganos , Fenoles/química , Fenoles/farmacología , Ratas , Ratas Wistar , Estereoisomerismo , Timol/química , Vasodilatación/fisiología , Vasodilatadores/química
11.
Biochem Biophys Res Commun ; 197(2): 501-7, 1993 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-7903528

RESUMEN

Brain endo-oligopeptidase A, a neuropeptide-metabolizing endopeptidase, has been considered a cysteine-endopeptidase because it is activated by thiols and inhibited by phydroxymercuribenzoate or 5,5'-dithiobis-(2-nitrobenzoic acid). The understanding of the unique specificity of endo-oligopeptidase A was useful for the synthesis of affinity labeling compounds containing as a thiol reactive group the Cys-(3-nitro-2-pyridinesulfenyl) group into dynorphin-derived peptides which are among the best substrates and competitive inhibitor of endopeptidase 22.19. Of the ten compounds tested, only peptides containing 8 to 13 amino acid residues caused irreversible inhibition. The fact that the most effective inhibitors had the reactive group either at the P'1 or at P'3 position [nomenclature of Schechter and Berger] would seem to argue that the reactive cysteine is in the vicinity of the active site, or actually involved in the catalytic step.


Asunto(s)
Encéfalo/enzimología , Cisteína , Dinorfinas/química , Metaloendopeptidasas/metabolismo , Oligopéptidos/farmacología , Fragmentos de Péptidos/química , Secuencia de Aminoácidos , Animales , Bovinos , Cromatografía Líquida de Alta Presión , Dinorfinas/metabolismo , Cinética , Metaloendopeptidasas/aislamiento & purificación , Datos de Secuencia Molecular , Oligopéptidos/síntesis química , Fragmentos de Péptidos/aislamiento & purificación , Fragmentos de Péptidos/metabolismo , Especificidad por Sustrato
12.
J Pept Res ; 51(6): 452-9, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9650720

RESUMEN

The specificity of thimet oligopeptidase (EC 3.4.24.15) (TOP 24.15) does not agree with theoretical models devised to explain the specificity characteristic of peptidases toward certain sequences of amino acid residues. According to previous studies peptide chains hydrolyzed by TOP 24.15 adopt similar main chain conformations, although with different and in some cases small probabilities of occurrence in aqueous solution. To determine specific structural features recognized by TOP 24.15, a conformational search including eight polypeptides with known susceptibilities for catalytic hydrolysis was executed and the distribution of each main chain conformation found in the search was tabulated. Two sets of main chain conformations were selected, those common to all peptides in the study and those common only to substrates of TOP 24.15. The former set is very small and includes mainly extended conformations. In contrast, the latter set is large and its conformations are coiled and exhibit sharp turns coincident with positions of hydrolysis by TOP 24.15. These results indicate a possible basis for the selectivity of TOP 24.15.


Asunto(s)
Metaloendopeptidasas/química , Conformación Proteica , Cinética , Modelos Moleculares , Análisis de Secuencia , Especificidad por Sustrato
13.
Proc Natl Acad Sci U S A ; 98(25): 14440-5, 2001 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-11717410

RESUMEN

Muscle wasting is a debilitating consequence of fasting, inactivity, cancer, and other systemic diseases that results primarily from accelerated protein degradation by the ubiquitin-proteasome pathway. To identify key factors in this process, we have used cDNA microarrays to compare normal and atrophying muscles and found a unique gene fragment that is induced more than ninefold in muscles of fasted mice. We cloned this gene, which is expressed specifically in striated muscles. Because this mRNA also markedly increases in muscles atrophying because of diabetes, cancer, and renal failure, we named it atrogin-1. It contains a functional F-box domain that binds to Skp1 and thereby to Roc1 and Cul1, the other components of SCF-type Ub-protein ligases (E3s), as well as a nuclear localization sequence and PDZ-binding domain. On fasting, atrogin-1 mRNA levels increase specifically in skeletal muscle and before atrophy occurs. Atrogin-1 is one of the few examples of an F-box protein or Ub-protein ligase (E3) expressed in a tissue-specific manner and appears to be a critical component in the enhanced proteolysis leading to muscle atrophy in diverse diseases.


Asunto(s)
Ligasas/genética , Proteínas Musculares/genética , Atrofia Muscular/genética , Proteínas Ligasas SKP Cullina F-box , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Ayuno/metabolismo , Expresión Génica , Masculino , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Atrofia Muscular/etiología , Atrofia Muscular/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , ARN Mensajero/metabolismo
14.
Br Med J (Clin Res Ed) ; 287(6384): 12-4, 1983 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-6407676

RESUMEN

Twenty four hour intragastric acidity was measured in nine patients with duodenal ulcer before and after one week of treatment with oral omeprazole 30 mg daily, a drug that inhibits gastric secretion by inhibition of parietal cell H+K+ adenosinetriphosphatase (ATPase). Omeprazole virtually eliminated intragastric acidity in all patients: the median 24 hour intragastric pH rose from 1.4 to 5.3 and the mean hourly hydrogen ion activity fell from 38.50 to 1.95 mmol(mEq)/1 (p less than 0.001). This inhibition of 24 hour intragastric acidity is more profound than that previously reported with either cimetidine 1 g daily or ranitidine 300 mg daily.


Asunto(s)
Bencimidazoles/uso terapéutico , Úlcera Duodenal/tratamiento farmacológico , Ácido Gástrico/metabolismo , Administración Oral , Adulto , Anciano , Bencimidazoles/administración & dosificación , Esquema de Medicación , Úlcera Duodenal/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Omeprazol
15.
Gut ; 25(9): 957-64, 1984 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6469081

RESUMEN

In a series of 59 experiments in nine duodenal ulcer patients, 24 hour intragastric acidity was measured before, during, and after treatment with daily oral omeprazole. Omeprazole 10, 20, and 30 mg/day for one week caused a 37, 90, and 97% decrease of 24 hour intragastric acidity, respectively. No further decrease of acidity was observed when the dose of omeprazole was doubled to 60 mg/day, or after a second week of treatment with 30 mg/day. One week after stopping treatment with omeprazole (14 doses) there was a significant 26% decrease of 24 hour intragastric acidity, with full recovery seven weeks later. Fasting plasma gastrin concentration was significantly raised during treatment with all doses of omeprazole. Omeprazole 30 mg/day is the optimal dose for a maximal decrease of 24 hour intragastric acidity in duodenal ulcer patients.


Asunto(s)
Antiulcerosos/administración & dosificación , Bencimidazoles/administración & dosificación , Ácido Gástrico/metabolismo , Adulto , Anciano , Antiulcerosos/efectos adversos , Antiulcerosos/sangre , Bencimidazoles/efectos adversos , Bencimidazoles/sangre , Relación Dosis-Respuesta a Droga , Úlcera Duodenal/tratamiento farmacológico , Gastrinas/sangre , Humanos , Masculino , Persona de Mediana Edad , Omeprazol , Factores de Tiempo
16.
Biochem Biophys Res Commun ; 191(1): 275-81, 1993 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-8447830

RESUMEN

An endopeptidase capable of metabolizing a number of neuropeptides and generating [Met5] and [Leu5] enkephalin from enkephalin-containing peptides is secreted by glioma C6 cells. This neutral endopeptidase that is likely to be a thiol protease, has a Mr of 71KDa and is effective only towards oligopeptides. Its specificity towards neuropeptides is identical to that of soluble endopeptidase 22.19. Moreover, when a partially purified preparation of enkephalin-generating enzyme secreted by glioma C6 cells was submitted to immunoblotting, an antiserum against purified brain endopeptidase 22.19 recognized a single band at Mr of 71 KDa. These data suggest that the soluble endopeptidase 22.19 may be secreted by glioma C6 cells thus allowing its participation in the biotransformation of opioid peptides in the CNS.


Asunto(s)
Glioma/enzimología , Metaloendopeptidasas/metabolismo , Neuropéptidos/metabolismo , Secuencia de Aminoácidos , Animales , Encefalina Leucina/metabolismo , Encefalina Metionina/metabolismo , Cinética , Datos de Secuencia Molecular , Ratas , Homología de Secuencia de Aminoácido , Especificidad por Sustrato , Células Tumorales Cultivadas
17.
Biochem J ; 324 ( Pt 2): 517-22, 1997 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-9182712

RESUMEN

A systematic analysis of the peptide sequences and lengths of several homologues of bioactive peptides and of a number of quenched-fluorescence (qf) opioid- and bradykinin-related peptides was performed to determine the main features leading the oligopeptides to hydrolysis by the recombinant rat testis thimet oligopeptidase (EC 3.4.24.15). The results indicate that a minimum substrate length of six amino acids is required and that among the oligopeptides six to thirteen amino acid residues long, their susceptibility as substrates is highly variable. Thimet oligopeptidase was able to hydrolyse, with similar catalytic efficiency, peptide bonds having hydrophobic or hydrophilic amino acids as well as proline in the P1 position of peptides, ranging from a minimum of six to a maximum of approximately thirteen amino acid residues. An intriguing observation was the shift of the cleavage site, at a Leu-Arg bond in qf dynorphin-(2-8) [qf-Dyn2-8; Abz-GGFLRRV-EDDnp, where Abz stands for o-aminobenzoyl and EDDnp for N-(2,4-dinitrophenyl)ethylenediamine], to Arg-Arg in qf-Dyn2-8Q, in which Gln was substituted for Val at its C-terminus. Similarly, a cleavage site displacement was also observed with the hydrolysis of the internally quenched-fluorescence bradykinin analogues containing Gln at the C-terminal position, namely Abz-RPPGFSPFR-EDDnp and Abz-GFSPFR-EDDnp are cleaved at the Phe-Ser bond, but Abz-RPPGFSPFRQ-EDDnp and Abz-GFSPFRQ-EDDnp are cleaved at the Pro-Phe bond.


Asunto(s)
Metaloendopeptidasas/metabolismo , Oligopéptidos/química , Secuencia de Aminoácidos , Animales , Bradiquinina/metabolismo , Fenómenos Químicos , Química Física , Dinorfinas/metabolismo , Hidrólisis , Masculino , Datos de Secuencia Molecular , Oligopéptidos/metabolismo , Ratas , Proteínas Recombinantes de Fusión/metabolismo , Relación Estructura-Actividad , Especificidad por Sustrato , Testículo/enzimología
18.
Biol Chem Hoppe Seyler ; 377(5): 283-91, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8828819

RESUMEN

The recombinant rat testes metallo-endooligopeptidase (EC 3.4.24.15) and the rabbit brain endooligopeptidase A (formerly EC 3.4.22.19) were compared, side-by-side, in view of their striking similarities in both the physicochemical features and the specificities for oligopeptides. Concerning the tissue distribution in rat and rabbit, no relation between the levels of enzyme activity in cytosol and the levels of metallo-endooligopeptidase 24.15 mRNA could be established. The results suggest that the predominant neuropeptide-metabolizing activity attributed to the metallo-endooligopeptidase 24.15 is performed by, at least, two distinct cytosolic enzymes, one predominant in rat testes and the other in rabbit brain and testes, and possibly also in rat brain. Both enzymes are activated by dithiothreitol and irreversibly inhibited by a SH-affinity labeling dynorphin-related compound, but they are not inhibited by EDTA in a concentration dependent manner. Both enzymes exhibit the same specificity toward several bioactive peptides, except for LH-RH and substance P, which are only hydrolysed by the rat testes enzyme. Taken together, these results lead us to conclude that it is unlikely that the recombinant rat testes metallo-endooligopeptidase 24.15 and the rabbit brain endooligopeptidase A are the same molecule although they might belong to the same family of oligopeptidases.


Asunto(s)
Metaloendopeptidasas/metabolismo , Secuencia de Aminoácidos , Animales , Northern Blotting , Western Blotting , Encéfalo/enzimología , Quelantes/farmacología , Citosol/enzimología , Ditiotreitol/farmacología , Ácido Edético/farmacología , Electroforesis en Gel de Poliacrilamida , Hidrólisis , Masculino , Metaloendopeptidasas/antagonistas & inhibidores , Metaloendopeptidasas/aislamiento & purificación , Datos de Secuencia Molecular , Conejos , Ratas , Proteínas Recombinantes/química , Especificidad de la Especie , Especificidad por Sustrato , Reactivos de Sulfhidrilo/farmacología , Testículo/enzimología
19.
J Cell Biochem ; 76(3): 478-88, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10649444

RESUMEN

We combined fluorogenic substrates or internally quenched fluorescent peptides with specific inhibitors in the pH profile of proteolytic activity experiments in order to detect proteolytic activities in lysates of MDCK cells. Hydrolytic activities related to cathepsin B, L, and D were observed. Serine-proteinase was not detected; however, we clearly demonstrated the presence of a thiol-metallo-endo-oligopeptidase, also called thimet-oligopeptidase (TOP). This peptidase from MDCK cells has substrate and inhibitor specificities as well as an activation profile with mercaptoethanol that are indistinguishable from the recombinant rat testis TOP (EC 3. 4.24.15). In addition, polyclonal purified antibodies to this enzyme depleted the TOP activity of MDCK cells in whole homogenate. Although we present only preliminary data, TOP is secreted by MDCK cells. The presence of TOP in a phenotype polarized MDCK cells can have special significance in the cytoplasmic selection, transport, or clearance of short peptides due to restriction of the enzyme to sequences from 6 to 17 amino acids. Therefore, the MDCK cell could be a very useful cellular model with which to study some of the suggested TOP biological functions as processing of biological active peptides and antigen presentation.


Asunto(s)
Riñón/enzimología , Metaloendopeptidasas/metabolismo , Péptido Hidrolasas/metabolismo , Secuencia de Aminoácidos , Animales , Ácido Aspártico Endopeptidasas/aislamiento & purificación , Ácido Aspártico Endopeptidasas/metabolismo , Dominio Catalítico , Línea Celular , Cromatografía Líquida de Alta Presión , Cisteína Endopeptidasas/aislamiento & purificación , Cisteína Endopeptidasas/metabolismo , Perros , Riñón/citología , Masculino , Metaloendopeptidasas/química , Metaloendopeptidasas/aislamiento & purificación , Oligopéptidos/química , Péptido Hidrolasas/aislamiento & purificación , Ratas , Especificidad por Sustrato , Testículo/enzimología
20.
Biochem Biophys Res Commun ; 255(3): 596-601, 1999 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-10049756

RESUMEN

In this study we investigated the fate of a class of proteasome-generated oligopeptides, exposing them to the crude cytosol of macrophages or to the purified recombinant thimet oligopeptidase. Among the proteasome products of known sequences are MHC class I epitopes, 13 of which were randomly chosen to be used as putative substrates. Surprisingly, our results clearly showed that the majority of the peptides were poorly or not degraded, either by the purified enzyme or by the crude macrophage cytosol. The peptides, which were resistant to hydrolysis, displayed high affinity for the thimet oligopeptidase as competitive inhibitors. Regardless of the fact that our data do not allow prediction of whether or not a specific peptide would be degraded, it seems very likely that the structural features, which rule out the stability of the MHC class I peptides in the cytosol, may have implications in an optimized repertoire selection for antigen presentation.


Asunto(s)
Antígenos de Histocompatibilidad Clase I/metabolismo , Macrófagos/enzimología , Metaloendopeptidasas/metabolismo , Oligopéptidos/metabolismo , Animales , Presentación de Antígeno/inmunología , Células Presentadoras de Antígenos/enzimología , Cisteína Endopeptidasas/metabolismo , Inhibidores Enzimáticos/farmacología , Epítopos/química , Epítopos/inmunología , Cinética , Masculino , Complejos Multienzimáticos/metabolismo , Oligopéptidos/farmacología , Complejo de la Endopetidasa Proteasomal , Ratas , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato , Testículo/enzimología
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