Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Braz J Biol ; 84: e279881, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38422299

RESUMEN

Understanding how functionally similar species segregate resources to minimize competition is vital for predicting evolutionary factors and patterns of coexistence. We conducted a study in Mata de Itamacaoca, in the middle Munim River basin, Maranhão, northeastern Brazil, to characterize the functional morphology and trophic niches of five coexisting Characiform species in this area - including a recently described species, and to investigate whether their functional morphology is a key determinant of their trophic niches. Our analysis of functional morphology and diet, employing linear measurements to predict dietary specializations, showed that these species are predominantly generalist insectivores with a significant morphological overlap. This study underscores the influence of species' natural history on their ecological characteristics, contributing to more effective conservation strategies.


Asunto(s)
Cadena Alimentaria , Ríos , Animales , Brasil , Peces , Dieta
2.
Hernia ; 27(4): 795-806, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37270718

RESUMEN

PURPOSE: Obturator Hernia (OH) is a rare type of abdominal wall hernia. It usually occurs in elderly women with late symptomatic presentation, increasing mortality rates. Surgery is the standard of care for OH, and laparotomy with simple suture closure of the defect is commonly used. Given the rarity of this disease, large studies are lacking, and data to drive management are still limited. This systematic review and meta-analysis aimed to describe current surgical options for OHs, with a focus on comparing the effectiveness and safety of mesh use with primary repair. METHODS: PubMed, EMBASE, and Cochrane were searched for studies comparing mesh and non-mesh repair for OH. Postoperative outcomes were assessed by pooled analysis and meta-analysis. Statistical analysis was performed using RevMan 5.4. RESULTS: One thousand seven hundred and sixty studies were screened and sixty-seven were thoroughly reviewed. We included 13 observational studies with 351 patients surgically treated for OH with mesh or non-mesh repair. One hundred and twenty (34.2%) patients underwent mesh repair and two hundred and thirty-one (65.81%) underwent non-mesh repair. A total of 145 (41.3%) underwent bowel resection, with the majority having a non-mesh repair performed. Hernia recurrence was significantly higher in patients who underwent hernia repair without mesh (RR 0.31; 95% CI 0.11-0.94; p = 0.04). There were no differences in mortality (RR 0.64; 95% CI 0.25-1.62; p = 0.34; I2 = 0%) or complication rates (RR 0.59; 95% CI 0.28-1.25; p = 0.17; I2 = 50%) between both groups. CONCLUSION: Mesh repair in OH was associated with lower recurrence rates without an increase in postoperative complications. While mesh in clean cases is more likely to offer benefits, an overall recommendation regarding its use in OH repair cannot be made due to potential bias across studies. Given that many OH patients are frail and present emergently, the decision to use mesh is complex and should consider the patient's clinical status, comorbidities, and degree of intraoperative contamination.


Asunto(s)
Hernia Obturadora , Hernia Ventral , Humanos , Femenino , Anciano , Hernia Obturadora/cirugía , Herniorrafia/efectos adversos , Mallas Quirúrgicas/efectos adversos , Hernia Ventral/etiología , Complicaciones Posoperatorias/etiología , Recurrencia
3.
Braz. j. biol ; 78(4): 697-705, Nov. 2018. tab, graf
Artículo en Inglés | LILACS | ID: biblio-951600

RESUMEN

Abstract Between July 2014 and April 2015, we conducted weekly inventories of the circadian activity patterns of mammals in Passo Novo locality, municipality of Alegrete, southern Brazil. The vegetation is comprised by a grassy-woody steppe (grassland). We used two camera traps alternately located on one of four 1 km transects, each separated by 1 km. We classified the activity pattern of species by the percentage of photographic records taken in each daily period. We identify Cuniculus paca individuals by differences in the patterns of flank spots. We then estimate the density 1) considering the area of riparian forest present in the sampling area, and 2) through capture/recapture analysis. Cuniculus paca, Conepatus chinga and Hydrochoerus hydrochaeris were nocturnal, Cerdocyon thous had a crepuscular/nocturnal pattern, while Mazama gouazoubira was cathemeral. The patterns of circadian activity observed for medium and large mammals in this Pampa region (southern grasslands) may reflect not only evolutionary, biological and ecological affects, but also human impacts not assessed in this study. We identified ten individuals of C. paca through skin spot patterns during the study period, which were recorded in different transects and months. The minimum population density of C. paca was 3.5 individuals per km2 (resident animals only) and the total density estimates varied from 7.1 to 11.8 individuals per km2, when considering all individuals recorded or the result of the capture/recapture analysis, respectively.


Resumo De julho de 2014 a abril de 2015, realizamos levantamentos semanais para estudar padrões de atividade circadiana da mastofauna na localidade de Passo Novo, Alegrete, sul do Brasil. A vegetação é compreendida por savana estépica (campo). Utilizamos duas armadilhas fotográficas distribuídas alternadamente ao longo de quatro transectos, com extensão de 1 km e distantes cerca de 1 km entre si. Nós classificamos o padrão de atividade das espécies através da percentagem de fotos registradas em cada período diário. Nós identificamos indivíduos de Cuniculus paca através dos diferentes padrões de manchas nos flancos dos animais. Nós então estimamos a densidade 1) considerando a área de floresta ripária presente na área amostrada, e 2) através da análise de captura/recaptura. As espécies Cuniculus paca, Conepatus chinga e Hydrochoerus hydrochaeris foram classificadas como noturnas, Cerdocyon thous apresentou um padrão crepuscular/noturno, enquanto Mazama gouazoubira foi classificada como catemeral. O padrão de atividade circadiana observado para os mamíferos de médio e grande porte nessa região do Pampa (campos sulinos) pode refletir não só aspectos evolutivos, biológicos e ecológicos, mas também impactos humanos não avaliados nesse estudo. Através do padrão de manchas da pelagem de C. paca nós identificamos dez indivíduos durante o período de estudo, que foram registrados em diferentes transectos e meses. A densidade populacional mínima de C. paca foi de 3,5 ind/km2 (apenas indivíduos residentes) e a densidade total variou de 7,1 a 11,8 ind/km2, quando consideramos todos os indivíduos registrados ou com base em análises de captura e recaptura, respectivamente.


Asunto(s)
Animales , Ritmo Circadiano/fisiología , Mamíferos/fisiología , Brasil , Bosques , Densidad de Población , Ecología , Evolución Biológica
4.
Braz J Biol ; 78(4): 697-705, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29489928

RESUMEN

Between July 2014 and April 2015, we conducted weekly inventories of the circadian activity patterns of mammals in Passo Novo locality, municipality of Alegrete, southern Brazil. The vegetation is comprised by a grassy-woody steppe (grassland). We used two camera traps alternately located on one of four 1 km transects, each separated by 1 km. We classified the activity pattern of species by the percentage of photographic records taken in each daily period. We identify Cuniculus paca individuals by differences in the patterns of flank spots. We then estimate the density 1) considering the area of riparian forest present in the sampling area, and 2) through capture/recapture analysis. Cuniculus paca, Conepatus chinga and Hydrochoerus hydrochaeris were nocturnal, Cerdocyon thous had a crepuscular/nocturnal pattern, while Mazama gouazoubira was cathemeral. The patterns of circadian activity observed for medium and large mammals in this Pampa region (southern grasslands) may reflect not only evolutionary, biological and ecological affects, but also human impacts not assessed in this study. We identified ten individuals of C. paca through skin spot patterns during the study period, which were recorded in different transects and months. The minimum population density of C. paca was 3.5 individuals per km2 (resident animals only) and the total density estimates varied from 7.1 to 11.8 individuals per km2, when considering all individuals recorded or the result of the capture/recapture analysis, respectively.


Asunto(s)
Ritmo Circadiano/fisiología , Mamíferos/fisiología , Animales , Evolución Biológica , Brasil , Ecología , Bosques , Densidad de Población
5.
Scand J Med Sci Sports ; 26(2): 206-13, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25648423

RESUMEN

This study aimed to estimate the prevalence of the main perceived barriers to leisure-time physical activity (LTPA) and their associations with the frequency of LTPA in a representative sample of industrial workers from Brazil (n = 47,477), according to their income strata (low income: ≤$US280, middle income: $US281-$US1400, and high income: ≥$US1401). Data were collected between 2006 and 2008 via questionnaires about the main perceived barrier to LTPA and the frequency of LTPA. Multinomial logistic regression was performed to evaluate differences among groups. There was a lower prevalence of regular practice of LTPA in the low- (15.8%) and middle-income strata (18.2%) than among the individuals of the high-income stratum (27.6%). A large proportion of workers who regularly participated in LTPA reported no barriers (low: 43.1%; middle: 46.8%; high: 51.6%). Additional obligations and fatigue were the two most common perceived barriers in all family income strata among participants who engaged in different frequencies of LTPA. The odds for all perceived barriers showed a positive trend related to frequency of LTPA (from regular to no LTPA), with higher values according to income. In summary, the ordering of the main perceived barriers to LTPA differed according to workers' income stratum and frequency of engaging in LTPA.


Asunto(s)
Renta , Actividades Recreativas/economía , Actividad Motora , Adulto , Brasil , Estudios Transversales , Fatiga , Femenino , Humanos , Actividades Recreativas/psicología , Masculino , Persona de Mediana Edad , Motivación
8.
Biotechnol Lett ; 31(9): 1315-9, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19466561

RESUMEN

The objective of this work was to evaluate the feasibility of ethanol production by fermentation of coffee husks by Saccharomyces cerevisiae. Batch fermentation studies were performed employing whole and ground coffee husks, and aqueous extract from ground coffee husks. It was observed that fermentation yield decreased with an increase in yeast concentration. The best results were obtained for the following conditions: whole coffee husks, 3 g yeast/l substrate, temperature of 30 degrees C. Under these conditions ethanol production was 8.49 +/- 0.29 g/100 g dry basis (13.6 +/- 0.5 g ethanol/l), a satisfactory value in comparison to literature data for other residues such as corn stalks, barley straw and hydrolyzed wheat stillage (5-11 g ethanol/l). Such results indicate that coffee husks present excellent potential for residue-based ethanol production.


Asunto(s)
Café/metabolismo , Etanol/metabolismo , Saccharomyces cerevisiae/metabolismo , Fermentación , Saccharomyces cerevisiae/crecimiento & desarrollo , Temperatura
9.
J Appl Microbiol ; 103(6): 2438-47, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18045429

RESUMEN

AIMS: To test indigenous Saccharomyces cerevisiae as starters to produce cachaça in large-scale in a traditional distillery, establishing the period in which, each strain predominates in the vats, chemical composition and sensory attributes of the beverage, and to compare these data with vats prepared by spontaneous fermentation. METHODS AND RESULTS: Strains were evaluated for kinetic fermentation parameters, permanence in vats, volatile compound production, and sensory attributes for the cachaças produced. In general the vats in which starter strains were used, no difference in restriction mitochondrial DNA (mtDNA) profiles of isolates was observed. In the vats in which spontaneous fermentation occurred, different mtDNA restriction profiles were observed. Most of the non-Saccharomyces species isolated could be regarded as contaminants of fermentation. All cachaças produced, despite being recently distilled and with differences in their chemical composition, were well accepted by the judges. CONCLUSIONS: It was possible to detect the differences in the fermentation capacities of S. cerevisiae strains, in their relative abundances at different time periods, and in the chemical compositions and sensory attributes of the resulting beverages. SIGNIFICANCE AND IMPACT OF THE STUDY: The indigenous strains utilized to prepare cachaça have shown potential to be used as starters of this traditional fermentation process.


Asunto(s)
Microbiología de Alimentos , Microbiología Industrial , Saccharomyces cerevisiae/fisiología , Vino , Fermentación , Genes Fúngicos , Saccharomyces cerevisiae/genética , España
11.
Rev Bras Enferm ; 54(4): 623-9, 2001.
Artículo en Portugués | MEDLINE | ID: mdl-12102050

RESUMEN

The present study shows the dynamics of employment for the nursing profession in Brazil from 1970 up to 1990. It outlines the main characteristics and trends of this labor market before and after the implantation of the Sistema Unico de Saúde-SUS (Federal Health Care System). The main source of information for this investigation was data published in the research Medical-Sanitary Assistance carried out by IBGE (Brazilian Geography and Statistics Institute).


Asunto(s)
Empleo/estadística & datos numéricos , Enfermería/estadística & datos numéricos , Brasil , Humanos , Sector Privado/estadística & datos numéricos , Sector Público/estadística & datos numéricos
12.
Sci Total Environ ; 261(1-3): 169-76, 2000 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-11036988

RESUMEN

Gold extraction and its commercialization in the Amazon region is mainly by rudimentary procedures. Therefore, during the process of extraction and recovery of this precious metal, large amounts of mercury vapors are thrown into the environment. This paper is an attempt to establish a correlation between the concentration of total mercury in the urine of workers at the gold shop in the Municipality of Itaituba, Pará, and the information related to the lifestyles of each individual studied. Through statistical analysis, it was possible to divide the workers into three groups: people with normal mercury concentrations, [Hg] < or = 10 ppb, (29%); with concentrations at the biological limit of tolerance, [Hg] up to 50 ppb, (49%); and contaminated people, [Hg] > or = 50 ppb (22%). It may be concluded that fish consumption, time of alcohol consumption, number of amalgam fillings, as well as working hours, are important variables when evaluating mercurial contamination of people who are occupationally exposed to mercury vapors.


Asunto(s)
Mercurio/orina , Exposición Profesional/análisis , Adulto , Oro , Humanos , Exposición por Inhalación , Masculino , Persona de Mediana Edad , Volatilización
13.
Braz J Med Biol Res ; 32(12): 1505-13, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10585632

RESUMEN

To investigate the role of nitric oxide in human sepsis, ten patients with severe septic shock requiring vasoactive drug therapy and mechanical ventilation were enrolled in a prospective, open, non-randomized clinical trial to study the acute effects of methylene blue, an inhibitor of guanylate cyclase. Hemodynamic and metabolic variables were measured before and 20, 40, 60, and 120 min after the start of a 1-h intravenous infusion of 4 mg/kg of methylene blue. Methylene blue administration caused a progressive increase in mean arterial pressure (60 [55-70] to 70 [65-100] mmHg, median [25-75th percentiles]; P<0.05), systemic vascular resistance index (649 [479-1084] to 1066 [585-1356] dyne s-1 cm-5 m-2; P<0.05) and the left ventricular stroke work index (35 [27-47] to 38 [32-56] g m-1 m-2; P<0.05) from baseline to 60 min. The pulmonary vascular resistance index increased from 150 [83-207] to 186 [121-367] dyne s-1 cm-5 m-2 after 20 min (P<0.05). Mixed venous saturation decreased from 65 [56-76] to 63 [55-69]% (P<0.05) after 60 min. The PaO2/FiO2 ratio decreased from 168 [131-215] to 132 [109-156] mmHg (P<0.05) after 40 min. Arterial lactate concentration decreased from 5.1 +/- 2.9 to 4.5 +/- 2.1 mmol/l, mean +/- SD (P<0.05) after 60 min. Heart rate, cardiac filling pressures, cardiac output, oxygen delivery and consumption did not change. Methylene blue administration was safe and no adverse effect was observed. In severe human septic shock, a short infusion of methylene blue increases systemic vascular resistance and may improve myocardial function. Although there was a reduction in blood lactate concentration, this was not explained by an improvement in tissue oxygenation, since overall oxygen availability did not change. However, there was a significant increase in pulmonary vascular tone and a deterioration in gas exchange. Further studies are needed to demonstrate if nitric oxide blockade with methylene blue can be safe for patients with septic shock and, particularly, if it has an effect on pulmonary function.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Pulmón/efectos de los fármacos , Azul de Metileno/farmacología , Óxido Nítrico/antagonistas & inhibidores , Choque Séptico/metabolismo , Resistencia Vascular/efectos de los fármacos , Adulto , Análisis de Varianza , Presión Sanguínea/efectos de los fármacos , Femenino , Humanos , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Óxido Nítrico/fisiología , Proyectos Piloto , Embarazo , Estudios Prospectivos , Insuficiencia Respiratoria/metabolismo , Insuficiencia Respiratoria/fisiopatología , Choque Séptico/fisiopatología
14.
Braz. j. med. biol. res ; 32(12): 1505-13, Dec. 1999. tab, ilus
Artículo en Inglés | LILACS | ID: lil-249376

RESUMEN

To investigate the role of nitric oxide in human sepsis, ten patients with severe septic shock requiring vasoactive drug therapy and mechanical ventilation were enrolled in a prospective, open, non-randomized clinical trial to study the acute effects of methylene blue, an inhibitor of guanylate cyclase. Hemodynamic and metabolic variables were measured before and 20, 40, 60, and 120 min after the start of a 1-h intravenous infusion of 4 mg/kg of methylene blue. Methylene blue administration caused a progressive increase in mean arterial pressure (60 [55-70] to 70 [65-100] mmHg, median [25-75th percentiles]; P<0.05), systemic vascular resistance index (649 [479-1084] to 1066 [585-1356] dyne s-1 cm-5 m-2; P<0.05) and the left ventricular stroke work index (35 [27-47] to 38 [32-56] g m-1 m-2; P<0.05) from baseline to 60 min. The pulmonary vascular resistance index increased from 150 [83-207] to 186 [121-367] dyne s-1 cm-5 m-2 after 20 min (P<0.05). Mixed venous saturation decreased from 65 [56-76] to 63 [55-69] per cent (P<0.05) after 60 min. The PaO2/FiO2 ratio decreased from 168 [131-215] to 132 [109-156] mmHg (P<0.05) after 40 min. Arterial lactate concentration decreased from 5.1 + or - 2.9 to 4.5 + or - 2.1 mmol/l, mean + or - SD (<0.05) after 60 min. Heart rate, cardiac filling pressures, cardiac output, oxygen delivery and consumption did not change. Methylene blue administration was safe and no adverse effect was observed. In severe human septic shock, a short infusion of methylene blue increases systemic vascular resistance and may improve myocardial function. Although there was a reduction in blood lactate concentration, this was not explained by an improvement in tissue oxygenation, since overall oxygen availability did not change. However, there was a significant increase in pulmonary vascular tone and a deterioration in gas exchange. Further studies are needed to demonstrate if nitric oxide blockade with methylene blue can be safe for patients with septic shock and, particularly, if it has an effect on pulmonary function.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Embarazo , Inhibidores Enzimáticos/farmacología , Pulmón/fisiología , Azul de Metileno/farmacología , Óxido Nítrico/antagonistas & inhibidores , Choque Séptico/metabolismo , Resistencia Vascular/efectos de los fármacos , Vasodilatadores/antagonistas & inhibidores , Anciano de 80 o más Años , Óxido Nítrico/fisiología , Estudios Prospectivos
15.
Cad Saude Publica ; 14 Suppl 3: 33-9, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9819463

RESUMEN

Serum levels of organochlorine pesticides (OCP) were measured in agricultural workers from Rio de Janeiro State, Brazil. Blood samples from 26 volunteers (24 males, 02 females, 17-60 years old) were taken in October 1997. OCP residues (op'DDT pp'DDT, pp'DDD, pp'DDE, aldrin, dieldrin, endrin, heptachlor, heptachlor-epoxide, (alpha-, beta- and gamma-hexachlorocyclohexane, and hexachlorobenzene) were analyzed by gas chromatography with an electron capture detector. Tests detected pp'DDE in 16 out of 26 samples, but pp'DDE concentration exceeded 1.4 (microgram/L (i.e. 1.8, 2.4 and 4.4 microgram/L) in only 3 of these. beta-HCH was found in 6 (23.1%) out of 26 samples. In one sample (-HCH did not exceed 1.4 microgram/L, but in the remaining samples concentrations ranged from 1.4 to 5.3 microgram/L. The percentage of positive pp'DDE samples increased from the youngest /= 40 yrs: 100%). A similar trend was found for beta-HCH contamination (/= 40 yrs: 66.7%). Dieldrin was found in only one sample. No other OCP residue was found in the samples. Serum concentrations of OCPs found in this study are comparable to blood levels reported for the non-occupationally exposed population in Brazil and elsewhere.


Asunto(s)
Agricultura , Hidrocarburos Clorados , Insecticidas/sangre , Exposición Profesional/análisis , Población Rural , Adolescente , Adulto , Factores de Edad , Agricultura/estadística & datos numéricos , Brasil , Cromatografía de Gases , Femenino , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional/estadística & datos numéricos , Población Rural/estadística & datos numéricos
16.
Respir Physiol ; 111(2): 223-31, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9574873

RESUMEN

The recently described burrow-dwelling Proechimys yonenagae from the Brazilian semiarid caatinga was compared to P. iheringi from the Brazilian rain forest of Mata Atlântica in terms of interactions between body temperature (Tb), ventilation (VE) and oxygen consumption (V(O2)) during hypercapnia (5 or 10% CO2). Wistar rats were also used as a control. VE was measured by plethysmography, Tb by inserting a probe into the colon, and V(O2) by a close-flow system. During air breathing, VE did not differ between the rodents, Wistar Tb was elevated compared to P. yonenagae, and the V(O2) values of P. yonenagae and P. iheringi were significantly lower than those of Wistar rats. Hypercapnia caused hyperventilation in the three rodents, hypothermia in P. yonenage and Wistar rats, but no change in V(O2) was observed in any of the rodents. The hypercapnia-induced hyperventilation may be a major factor producing heat loss. This effect was independent of V(O2). Comparisons of the two spiny rat species suggest little adaptation of P. yonenagae to hypercapnia in burrows.


Asunto(s)
Hipercapnia/fisiopatología , Muridae/fisiología , Respiración/fisiología , Aclimatación , Adaptación Fisiológica , Animales , Temperatura Corporal , Clima , Hiperventilación/fisiopatología , Hipotermia/fisiopatología , Masculino , Muridae/metabolismo , Consumo de Oxígeno , Ratas , Ratas Wistar , Especificidad de la Especie
17.
Eur J Pharmacol ; 253(1-2): 101-6, 1994 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-8013536

RESUMEN

Endo-oligopeptidase (EC 3.4.22.19), an enzyme capable of generating enkephalin by single cleavage from enkephalin-containing peptides, was examined in several areas of the central nervous system (CNS) as well as in the immune and endocrine tissues of rats chronically treated with morphine and submitted to naloxone-induced withdrawal. A specific fluorogenic substrate was used to determine the endopeptidase 22.19 activity. A non-uniform increase in endopeptidase 22.19 activity was detected in the CNS. The highest increase in endopeptidase 22.19 specific activity was found in the dorsal hippocampus (about 3.5-fold higher than control), followed by occipital and frontal cortex, substantia nigra, thalamus and hypothalamus. In peripheral tissues, a significant decrease of endopeptidase 22.19 was observed in the pineal gland, whereas the morphine withdrawal syndrome caused a slight but significant increase in lymphoid tissues such as lymph nodes and thymus. These findings are indicative of a possible participation of endopeptidase 22.19 in naloxone-induced withdrawal.


Asunto(s)
Encéfalo/enzimología , Metaloendopeptidasas/metabolismo , Morfina/toxicidad , Síndrome de Abstinencia a Sustancias/enzimología , Animales , Conducta Animal/efectos de los fármacos , Glándulas Endocrinas/enzimología , Lóbulo Frontal/enzimología , Ganglios Espinales/enzimología , Hipotálamo/enzimología , Tejido Linfoide/enzimología , Masculino , Naloxona/administración & dosificación , Naloxona/farmacología , Lóbulo Occipital/enzimología , Ratas , Ratas Wistar , Sustancia Negra/enzimología , Tálamo/enzimología
18.
J Neuroimmunol ; 38(1-2): 35-44, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1577951

RESUMEN

Neuropeptides have been shown to modulate the bidirectional communication between the central nervous and immune systems. The endooligopeptidase (EC 3.4.22.19), originally isolated and characterized in the nervous tissue, was shown to hydrolyse several neuropeptides and to generate enkephalin from enkephalin-containing peptides. This report shows the presence of endopeptidase 22.19 in the rat immune system using both biochemical and immunochemical methods. The specific activity of endopeptidase 22.19 in soluble fraction of lymphocytes was 3-4-fold higher than the one found in the nervous tissue. Among rat blood cells the highest specific activity of endopeptidase 22.19 was found in T lymphocytes, being 2.5-fold higher than the activity found in other leukocytes. Immunocytochemical studies performed in tissues and cells of the immune system indicate the presence of endopeptidase 22.19-like enzyme in all types of leukocytes. The occurrence of this enzyme in cells of the immune system can be considered an important step in understanding the metabolism of neuropeptides in the immune system as well as its possible participation as a regulatory enzyme in neuroimmunomodulation.


Asunto(s)
Cisteína Endopeptidasas/metabolismo , Endopeptidasas/metabolismo , Sistema Inmunológico/enzimología , Metaloendopeptidasas , Neuropéptidos/metabolismo , Animales , Células Sanguíneas/enzimología , Western Blotting , Sistema Inmunológico/citología , Inmunohistoquímica , Hígado , Linfocitos/enzimología , Tejido Linfoide/citología , Tejido Linfoide/enzimología , Fracciones Subcelulares/enzimología
19.
Biochem Biophys Res Commun ; 173(2): 647-52, 1990 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-2260976

RESUMEN

A novel quenched fluorescence substrate, QF-ERP7 (Abz-G-G-F-L-R-R-V-EDDn), structurally related to enkephalins, proved to be suitable for assaying the endooligopeptidase A (E.C.3.4.22.19) activity. The enzyme only splits the L-R bond (Km 1.75 microM, Kcat 8.25 s-1), a reaction efficiently blocked by anti-endooligopeptidase A antibodies and by inhibitor and alternative substrates of the enzyme. Evidences based on the action of inhibitors and on the analysis of QF-ERP7 fragments demonstrated that endooligopeptidase A contributes with 100% of the QF-ERP7 cleaving activity found in the cytosol of rabbit brain homogenates and with 85% of that recovered in the membrane fraction. Homologous substrates, Abz-G-G-F-L-R-R-EDDn and Abz-G-G-F-L-R-EDDn, were resistant to hydrolysis. The convenience and sensitivity of the fluorimetric assay based on the QF-ERP7 moiety offers several advantages compared with previously described painstaking procedures for endooligopeptidase A activity measurements, what will certainly contribute to further our understanding of the role of this enzyme on the peptide hormone metabolism.


Asunto(s)
Cisteína Endopeptidasas/análisis , Encefalinas , Etilenodiaminas , Fluorescencia , Metaloendopeptidasas , Oligopéptidos , Secuencia de Aminoácidos , Animales , Anticuerpos/inmunología , Cromatografía Líquida de Alta Presión , Cisteína Endopeptidasas/inmunología , Hidrólisis , Datos de Secuencia Molecular , Conejos
20.
J Neurochem ; 55(4): 1114-21, 1990 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2204681

RESUMEN

The subcellular and regional distribution of endo-oligopeptidase (EC 3.4.22.19), an enzyme capable of generating enkephalin by single cleavage from enkephalin-containing peptides, was determined by an enzymatic assay using metorphamide and by immunochemical techniques in the CNS of the rat. The rat CNS contains a membrane-associated form of endo-oligopeptidase, an enzyme predominantly associated with the soluble fraction of brain homogenates. Subcellular fractionation showed that approximately 17% of the total activity of the enzyme is associated with membrane fractions including synaptosomes. Synaptosomal membranes were prepared from neocortex, striatum, hypothalamus, medulla, spinal cord, and cerebellum. The amount of EC 3.4.22.19 activity solubilized by 3-[( 3-cholamidopropyl]dimethylammonio)-1-propanesulfonate from synaptosomal membranes was similar in neocortex, striatum, and hypothalamus, being three- to 10-fold greater than in spinal cord, cerebellum, and medulla. A polyclonal antibody exhibiting high affinity for endo-oligopeptidase was raised in rabbits against the purified rat brain enzyme and used to localize endo-oligopeptidase by Western blotting and by immunoperoxidase techniques. A strong band corresponding to the Mr of EC 3.4.22.19 was found in solubilized proteins obtained from synaptosomal membranes prepared from hypothalamus, neocortex, and striatum when subjected to Western blotting. The immunohistochemical localization of endo-oligopeptidase indicated that the immunoreactivity was confined to gray matter in regions known to be rich in peptide-containing neurons such as the striatum. In the cerebellum, a region poor in peptides, no staining could be detected. The nonuniform distribution of endo-oligopeptidase in rat brain suggests a role in neurotransmitter processing in the CNS.


Asunto(s)
Encéfalo/enzimología , Cisteína Endopeptidasas/metabolismo , Metaloendopeptidasas , Animales , Núcleo Celular/enzimología , Cisteína Endopeptidasas/aislamiento & purificación , Citosol/enzimología , Histocitoquímica , Técnicas para Inmunoenzimas , Masculino , Microsomas/enzimología , Mitocondrias/enzimología , Peso Molecular , Especificidad de Órganos , Ratas , Ratas Endogámicas , Sinaptosomas/enzimología , Sinaptosomas/ultraestructura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA