RESUMEN
INTRODUCTION: Orthotopic liver transplantation (OLT) is today the gold standard treatment of the end-stage liver disease. Different solutions are used for graft preservation. Our objective was to compare the results of cadaveric donor OLT, preserved with the University of Wisconsin (UW) or Celsior solutions in the portal vein and Euro-Collins in the aorta. METHODS: We evaluated retrospectively 72 OLT recipients, including 36 with UW solution (group UW) and 36 with Celsior (group CS). Donors were perfused in situ with 1000 mL UW or Celsior in the portal vein of and 3000 mL of Euro-Collins in the aortia and on the back table managed with 500 mL UW or Celsior in the portal vein, 250 mL in the hepatic artery, and 250 mL in the biliary duct. We evaluated the following variables: donor characteristics, recipient features, intraoperative details, reperfusion injury, and steatosis via a biopsy after reperfusion. We noted grafts with primary nonfunction (PNF), initial poor function (IPF), rejection episodes, biliary duct complications, hepatic artery complications, re-OLT, and recipient death in the first year after OLT. RESULTS: The average age was 33.6 years in the UW group versus 41 years in the CS group (P = .048). There was a longer duration of surgery in the UW group (P = .001). The other recipient characteristics, ischemia-reperfusion injury, steatosis, PNF, IPF, rejection, re-OLT, and recipient survival were not different. Stenosis of the biliary duct occured in 3 (8.3%) cases in the UW group and 8 (22.2%) in the CS (P = .19) with hepatic artery thrombosis in 4 (11.1%) CS versus none in the UW group (P = .11). CONCLUSION: Cadaveric donor OLT showed similar results with organs preserved with UW or Celsior in the portal vein and Euro-Collins in the aorta.
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Aorta Abdominal/fisiología , Soluciones Hipertónicas/uso terapéutico , Fallo Hepático/cirugía , Trasplante de Hígado/métodos , Soluciones Preservantes de Órganos/uso terapéutico , Vena Porta/fisiología , Adenosina/uso terapéutico , Adolescente , Adulto , Anciano , Alopurinol/uso terapéutico , Aorta Abdominal/efectos de los fármacos , Cadáver , Niño , Preescolar , Disacáridos/uso terapéutico , Electrólitos/uso terapéutico , Femenino , Glutamatos/uso terapéutico , Glutatión/uso terapéutico , Histidina/uso terapéutico , Humanos , Inmunosupresores/uso terapéutico , Insulina/uso terapéutico , Trasplante de Hígado/inmunología , Masculino , Manitol/uso terapéutico , Persona de Mediana Edad , Preservación de Órganos/métodos , Vena Porta/efectos de los fármacos , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Rafinosa/uso terapéutico , Daño por Reperfusión/epidemiología , Estudios Retrospectivos , Donantes de TejidosRESUMEN
We compared the effect of the number of weekly repetitions of a static stretching program on the flexibility, hamstring tightness and electromyographic activity of the hamstring and of the triceps surae muscles. Thirty-one healthy subjects with hamstring tightness, defined as the inability to perform total knee extension, and shortened triceps surae, defined by a tibiotarsal angle wider than 90° during trunk flexion, were divided into three groups: G1 performed the stretching exercises once a week; G2, three times a week, and G3, five times a week. The parameters were determined before and after the stretching program. Flexibility improved in all groups after intervention, from 7.65 ± 10.38 to 3.67 ± 12.08 in G1, from 10.73 ± 12.07 to 0.77 ± 10.45 in G2, and from 14.20 ± 10.75 to 6.85 ± 12.19 cm in G3 (P < 0.05 for all comparisons). The increase in flexibility was higher in G2 than in G1 (P = 0.018), while G2 and G3 showed no significant difference (G1: 4 ± 2.17, G2: 10 ± 5.27; G3: 7.5 ± 4.77 cm). Hamstring tightness improved in all groups, from 37.90 ± 6.44 to 29 ± 11.65 in G1, from 39.82 ± 9.63 to 21.91 ± 8.40 in G2, and from 37.20 ± 6.63 to 26.10 ± 5.72° in G3 (P < 0.05 for all comparisons). During stretching, a statistically significant difference was observed in electromyographic activity of biceps femoris muscle between G1 and G3 (P = 0.048) and G2 and G3 (P = 0.0009). No significant differences were found in electromyographic activity during maximal isometric contraction. Stretching exercises performed three times a week were sufficient to improve flexibility and range of motion compared to subjects exercising once a week, with results similar to those of subjects who exercised five times a week.
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Humanos , Ejercicios de Estiramiento Muscular/métodos , Músculo Esquelético/fisiología , Rango del Movimiento Articular/fisiología , Fenómenos Biomecánicos , Electromiografía , Factores de Tiempo , Muslo/fisiologíaRESUMEN
We compared the effect of the number of weekly repetitions of a static stretching program on the flexibility, hamstring tightness and electromyographic activity of the hamstring and of the triceps surae muscles. Thirty-one healthy subjects with hamstring tightness, defined as the inability to perform total knee extension, and shortened triceps surae, defined by a tibiotarsal angle wider than 90 degrees during trunk flexion, were divided into three groups: G1 performed the stretching exercises once a week; G2, three times a week, and G3, five times a week. The parameters were determined before and after the stretching program. Flexibility improved in all groups after intervention, from 7.65 +/- 10.38 to 3.67 +/- 12.08 in G1, from 10.73 +/- 12.07 to 0.77 +/- 10.45 in G2, and from 14.20 +/- 10.75 to 6.85 +/- 12.19 cm in G3 (P < 0.05 for all comparisons). The increase in flexibility was higher in G2 than in G1 (P = 0.018), while G2 and G3 showed no significant difference (G1: 4 +/- 2.17, G2: 10 +/- 5.27; G3: 7.5 +/- 4.77 cm). Hamstring tightness improved in all groups, from 37.90 +/- 6.44 to 29 +/- 11.65 in G1, from 39.82 +/- 9.63 to 21.91 +/- 8.40 in G2, and from 37.20 +/- 6.63 to 26.10 +/- 5.72 degrees in G3 (P < 0.05 for all comparisons). During stretching, a statistically significant difference was observed in electromyographic activity of biceps femoris muscle between G1 and G3 (P = 0.048) and G2 and G3 (P = 0.0009). No significant differences were found in electromyographic activity during maximal isometric contraction. Stretching exercises performed three times a week were sufficient to improve flexibility and range of motion compared to subjects exercising once a week, with results similar to those of subjects who exercised five times a week.
Asunto(s)
Ejercicios de Estiramiento Muscular/métodos , Músculo Esquelético/fisiología , Rango del Movimiento Articular/fisiología , Fenómenos Biomecánicos , Electromiografía , Humanos , Muslo/fisiología , Factores de TiempoRESUMEN
This article reports the case of a patient who underwent transjugular intrahepatic portosystemic shunt, which migrated to the right atrium. During liver transplantation, the extracardiac portion was sectioned and the portion adherent inside the atrium was managed expectantly.
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Atrios Cardíacos/cirugía , Complicaciones Intraoperatorias/fisiopatología , Trasplante de Hígado/efectos adversos , Derivación Portosistémica Intrahepática Transyugular/efectos adversos , Transfusión Sanguínea , Transfusión de Eritrocitos , Femenino , Humanos , Periodo Intraoperatorio , Transfusión de Plaquetas , Vena Porta/cirugíaRESUMEN
OBJETIVO: Verificar os efeitos de exercícios de alongamento muscular e condicionamento físico no tratamento fisioterápico da fibromialgia (FM). CASUÍSTICA E MÉTODOS: Foram avaliadas 15 mulheres com diagnóstico de FM, segundo os critérios do Colégio Americano de Reumatologia, divididas em dois grupos: Grupo 1 (G1) com oito pacientes, realizou tratamento por meio de alongamentos musculares e Grupo 2 (G2), sete pacientes, condicionamento físico. Foram avaliados qualidade do sono, fatores de piora e melhora da dor, sintomas associados e medicamentos utilizados. Além disso, foi aplicado o Fibromyalgia Impact Questionnaire (FIQ), para avaliar o impacto da FM. O tratamento durou oito semanas, sendo uma sessão semanal com duração de 40 a 45 minutos. As variáveis do FIQ antes e depois dos tratamentos foram comparadas pelo teste t para amostras dependentes (alfa< 0,05) e as demais foram analisadas descritivamente. RESULTADOS: A maioria das pacientes apresentava sono não reparador (86,67 por cento), piora da dor com serviços domésticos (40 por cento), nenhum fator de melhora da dor (28,57 por cento), distúrbios do sono como sintomas associados (100 por cento) e utilizava antidepressivos (69,23 por cento). Em relação às variáveis do FIQ, observaram-se diferenças estatisticamente significantes no sono (p= 0,0428) e rigidez matinal (p= 0,0130) nas pacientes do G1. Já no G2, não foram observadas diferenças significantes após o tratamento. CONCLUSÕES: Sugere-se que os alongamentos musculares realizados podem gerar impacto positivo na FM, promovendo melhora do sono e rigidez matinal das pacientes avaliadas.
OBJECTIVE: To investigate the effects of muscle stretching exercises and physical conditioning as physical therapy treatment for fibromyalgia. METHODS: Fifteen women with a diagnosis of fibromyalgia in accordance with the criteria of the American College of Rheumatology were evaluated and divided into two groups: Group 1 (G1, eight patients) underwent treatment consisting of muscle stretching and Group 2 (G2, seven patients), participated in a physical conditioning program. Sleep quality, pain-modulating factors, associated symptoms and medications used were evaluated. Furthermore, the Fibromyalgia Impact Questionnaire (FIQ) was applied to evaluate the impact of fibromyalgia. The treatment lasted for eight weeks, with one session per week of 40 to 45 minutes in duration. The FIQ data obtained before and after treatment were analyzed by means of Student's t test for dependent samples (alpha< 0.05) and other variables were analyzed descriptively. RESULTS: Most of the patients presented poor quality of sleep (86.67 percent). Many presented worsening of their pain when doing domestic tasks (40 percent) and there were no factors that relieved their pain (28.57 percent). All presented sleep disorders with associated symptoms (100 percent) and most used antidepressives (69.23 percent). For the FIQ data, statistically significant differences were observed in morning tiredness (p= 0.0428) and stiffness (p= 0.0130) among the G1 patients. Conversely, no difference was observed in G2 after the treatment. CONCLUSIONS: It is suggested that the muscle stretching may have had a positive impact on fibromyalgia, with reductions in morning tiredness and stiffness among the patients evaluated.
Asunto(s)
Humanos , Femenino , Ejercicio Físico , Fibromialgia , Aptitud Física , Modalidades de FisioterapiaRESUMEN
Photorhabdus sp. strain Az29 is symbiotic with an Azorean nematode of the genus Heterorhabditis in a complex that is highly virulent to insects even at low temperatures. The virulence of the bacteria is mainly attributed to toxins and bacterial enzymes secreted during parasitism. The bacteria secrete proteases during growth, with a peak at the end of the exponential growth phase. Protease secretion was higher in cultures growing at lower temperatures. At 10 degrees C the activity was highest and remained constant for over 7 days, whereas at 23 and 28 degrees C it showed a steady decrease. Two proteases, PrtA and PrtS, that are produced in the growth medium were purified by liquid chromatography. PrtA was inhibited by 1,10-phenantroline and by EDTA and had a molecular mass of 56 kDa and an optimal activity at pH 9 and 50 degrees C. Sequences of three peptides of PrtA showed strong homologies with alkaline metalloproteases from Photorhabdus temperata K122 and Photorhabdus luminescens W14. Peptide PrtA-36 contained the residues characteristic of metzincins, known to be involved in bacterial virulence. In vitro, PrtA inhibited antibacterial factors of inoculated Lepidoptera and of cecropins A and B. PrtS had a molecular mass of 38 kDa and was inhibited by 1,10-phenanthroline but not by EDTA. Its activity ranged between 10 and 80 degrees C and was optimal at pH 7 and 50 degrees C. PrtS also destroyed insect antibacterial factors. Three fragments of PrtS showed homology with a putative metalloprotease of P. luminescens TTO1. Polyclonal antibody raised against PrtA did not recognize PrtS, showing they are distinct molecules.
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Metaloendopeptidasas/aislamiento & purificación , Photorhabdus/enzimología , Secuencia de Aminoácidos , Animales , Péptidos Catiónicos Antimicrobianos/antagonistas & inhibidores , Hemolinfa/fisiología , Metaloendopeptidasas/química , Metaloendopeptidasas/farmacología , Datos de Secuencia Molecular , Photorhabdus/crecimiento & desarrollo , TemperaturaRESUMEN
Transjugular intrahepatic portosystemic shunt (TIPS) has been the therapeutic option for severe decompensation of chronic liver disease and as a bridge to liver transplantation. The aim of this study was to analyze the complications of this procedure. The records of 47 patients (39 men) of mean age 48 years underwent TIPS procedures from 1998 to 2003 were reviewed. Forty-one patients received 45 successful TIPS; it failed in six patients. Improvement was observed in 20 of 28 patients with upper gastrointestinal bleeding (71%); 9 of 11 with ascites (82%); and 5 of 8 with impaired renal function (62%). The Child-Pugh scores improved in 6 of the 47 patients (13%). Transplantation was performed in 11 patients (23%). The complications were: encephalopathy (49%); infection (19%); renal failure (17%); TIPS migration to the portal vein (4%) and to the right atrium (4%). Mortality was 32% (15/47) over 3 months. Eight patients developed active bleeding during TIPS installation requiring mechanical ventilation and intensive care, and died within the first week. Other causes of death were sepsis (n = 2), liver failure (n = 1), accidental puncture of the Glisson's capsule leading to intra-abdominal bleeding (n = 1) and refractory upper gastrointestinal bleeding (n = 3). The latter four patients had TIPS placement failure. In conclusion, TIPS produced clinical improvement among 51% of patients with complications in 49%. The main complications were encephalopathy (49%), infection (19%), and renal failure (17%). The 3-month mortality rate after TIPS placement was 32%.
Asunto(s)
Derivación Portosistémica Intrahepática Transyugular/efectos adversos , Causas de Muerte , Femenino , Humanos , Masculino , Registros Médicos , Persona de Mediana Edad , Derivación Portosistémica Intrahepática Transyugular/mortalidad , Estudios Retrospectivos , Insuficiencia del TratamientoRESUMEN
A disfuncao femoro-patelar constitui importante lesao musculo-esqueletica, acometendo adultos jovens e uma grande porcentagem de atletas. Varios fatores etiologicos estao envolvidos nessa patologia da articulacao femoro-patelar, a qual e estabilizada principalmentepor estruturas dinamicas - musculos. Somente apos o correto conhecimento dos estabilizadores dinamicos da articulacao femoro-patelar e dos principais fatores envolvidos em sua etiologia pode-se prescrever um correto protocolo de exercicios na reabilitacao funcional. Dentre os mais utilizados estao os exercicios em cadeia cinetica fechada, realizados com o segmento distal do membro inferior fixo. Exemplos desses exercicios sao o agachamento e os exercicios realizados no leg-press e no step. Apesar de varios estudos terem analisado os estabilizadores dinamicos da articulacao femoro-patelar nesses exercicios em cadeia cinetica fechada, faltam evidencias cientificas que comprovem o aumento da hipertrofia ou do desempenho muscular. Dessa forma, mais estudos biomecanicos, anatomicos e eletromiograficos tornam-se necessarios para embasar em cadeia cinetica fechada na reabilitacao de pacientes com disfuncao femoro-patelar
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Humanos , Ejercicio Físico , Articulación de la Rodilla , Ligamento Rotuliano , Sistema Musculoesquelético/lesionesRESUMEN
In the early secretory pathway, asparagine-linked glycosylation facilitates the conformational maturation of diverse polypeptides by promoting their physical engagement with the glycoprotein-folding machinery. Misfolded glycoproteins are selectively eliminated from the endoplasmic reticulum by a stringent process of conformation-based quality control. Recent studies indicate that a small ensemble of oligosaccharide-processing enzymes and lectins use the asparagine-linked appendage to orchestrate the selective disposal of numerous transport-defective glycoproteins from the early secretory pathway. The glycan-based disposal system functions as an evolutionarily conserved terminal checkpoint in eukaryote genome expression. That the mechanisms by which glycoprotein substrates are recruited for degradation diverge at the level of signal recognition reflects a previously unappreciated component of cellular differentiation in higher eukaryotes.
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Glicoproteínas/química , Animales , Asparagina/química , Proteínas de Unión al Calcio/metabolismo , Calnexina , Calreticulina , Secuencia de Carbohidratos , Retículo Endoplásmico/metabolismo , Glicoproteínas/metabolismo , Glicosilación , Manosidasas/metabolismo , Datos de Secuencia Molecular , Pliegue de Proteína , Control de Calidad , Ribonucleoproteínas/metabolismo , Transducción de SeñalRESUMEN
In the early secretory pathway, a distinct set of processing enzymes and family of lectins facilitate the folding and quality control of newly synthesized glycoproteins. In this regard, we recently identified a mechanism in which processing by endoplasmic reticulum mannosidase I, which attenuates the removal of glucose from asparagine-linked oligosaccharides, sorts terminally misfolded alpha(1)-antitrypsin for proteasome-mediated degradation in response to its abrogated physical dissociation from calnexin (Liu, Y., Choudhury, P., Cabral, C., and Sifers, R. N. (1999) J. Biol. Chem. 274, 5861-5867). In the present study, we examined the quality control of genetic variant PI Z, which undergoes inappropriate polymerization following biosynthesis. Here we show that in stably transfected hepatoma cells the additional processing of asparagine-linked oligosaccharides by endoplasmic reticulum mannosidase II partitions variant PI Z away from the conventional disposal mechanism in response to an arrested posttranslational interaction with calnexin. Intracellular disposal is accomplished by a nonproteasomal system that functions independently of cytosolic components but is sensitive to tyrosine phosphatase inhibition. The functional role of ER mannosidase II in glycoprotein quality control is discussed.
Asunto(s)
Retículo Endoplásmico/enzimología , Glicoproteínas/metabolismo , Manosidasas/metabolismo , alfa 1-Antitripsina/metabolismo , Animales , Arsenicales/farmacología , Secuencia de Carbohidratos , Variación Genética , Glicoproteínas/química , Humanos , Neoplasias Hepáticas Experimentales , Ratones , Datos de Secuencia Molecular , Ácido Ocadaico/metabolismo , Oligosacáridos/química , Oligosacáridos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Fluoruro de Sodio/farmacología , Transfección , Células Tumorales Cultivadas , Vanadatos/farmacología , alfa 1-Antitripsina/química , alfa 1-Antitripsina/genéticaRESUMEN
The role of conformation-based quality control in the early secretory pathway is to eliminate misfolded polypeptides and unassembled multimeric protein complexes from the endoplasmic reticulum, ensuring the deployment of only functional molecules to distal sites. The intracellular fate of terminally misfolded human alpha1-antitrypsin was examined in hepatoma cells to identify the functional role of asparagine-linked oligosaccharide modification in the selection of glycoproteins for degradation by the cytosolic proteasome. Proteasomal degradation required physical interaction with the molecular chaperone calnexin. Altered sedimentation of intracellular complexes following treatment with the specific proteasome inhibitor lactacystin, and in combination with mannosidase inhibition, revealed that the removal of mannose from attached oligosaccharides abrogates the release of misfolded alpha1-antitrypsin from calnexin prior to proteasomal degradation. Intracellular turnover was arrested with kifunensine, implicating the participation of endoplasmic reticulum mannosidase I in the disposal process. Accelerated degradation occurred in a mannosidase-independent manner and was arrested by lactacystin, in response to the posttranslational inhibition of glucosidase II, demonstrating that the attenuated removal of glucose from attached oligosaccharides functions as the underlying rate-limiting step in the proteasome-mediated pathway. A model is proposed in which the removal of mannose from multiple attached oligosaccharides directs calnexin in the selection of misfolded alpha1-antitrypsin for degradation by the proteasome.
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Cisteína Endopeptidasas/metabolismo , Complejos Multienzimáticos/metabolismo , Oligosacáridos/química , alfa 1-Antitripsina/metabolismo , Animales , Proteínas de Unión al Calcio/metabolismo , Calnexina , Inhibidores Enzimáticos/farmacología , Glucosa/metabolismo , Humanos , Hidrólisis , Manosidasas/antagonistas & inhibidores , Manosidasas/metabolismo , Ratones , Complejo de la Endopetidasa Proteasomal , Pliegue de Proteína , Células Tumorales Cultivadas , alfa 1-Antitripsina/químicaRESUMEN
Probiotics are formulations containing live microorganisms or microbial stimulants that have some beneficial influence on the maintenance of a balanced intestinal microbiota and on the resistance to infections. The search for probiotics to be used in prevention or treatment of enteric infections, as an alternative to antibiotic therapy, has gained significant impulse in the last few years. Several studies have demonstrated the beneficial effects of lactic acid bacteria in controlling infection by intestinal pathogens and in boosting the host's nonspecific immune response. Here, we studied the use of Lactobacillus acidophilus UFV-H2b20, a lactic acid bacterium isolated from a human newborn from Viçosa, Minas Gerais, Brazil, as a probiotic. A suspension containing 108 cells of Lactobacillus acidophilus UFV-H2b20 was inoculated into groups of at least five conventional and germfree Swiss mice to determine its capacity to stimulate the host mononuclear phagocytic activity. We demonstrate that this strain can survive the stressing conditions of the intestinal tract in vivo. Moreover, the monoassociation of germfree mice with this strain for seven days improved the host's macrophage phagocytic capacity, as demonstrated by the clearance of a Gram-negative bacterium inoculated intravenously. Monoassociated mice showed an undetectable number of circulating E. coli, while 0.1 percent of the original inoculum was still present in germfree animals. Mice treated with viable or heat-killed Lactobacillus acidophilus UFV-H2b20 presented similarly improved clearance capacity when compared with germfree controls. In addition, monoassociated mice had twice the amount of Kupffer cells, which are responsible for the clearance of circulating bacteria, compared to germfree controls. These results suggest that the L. acidophilus strain used here stimulates a nonspecific immune response and is a strong candidate to be used as a probiotic
Asunto(s)
Ratones , Animales , Sistema Digestivo/microbiología , Vida Libre de Gérmenes , Lactobacillus acidophilus/inmunología , Probióticos , Macrófagos del Hígado/metabolismo , Hígado/citología , MacrófagosRESUMEN
Probiotics are formulations containing live microorganisms or microbial stimulants that have some beneficial influence on the maintenance of a balanced intestinal microbiota and on the resistance to infections. The search for probiotics to be used in prevention or treatment of enteric infections, as an alternative to antibiotic therapy, has gained significant impulse in the last few years. Several studies have demonstrated the beneficial effects of lactic acid bacteria in controlling infection by intestinal pathogens and in boosting the host's nonspecific immune response. Here, we studied the use of Lactobacillus acidophilus UFV-H2b20, a lactic acid bacterium isolated from a human newborn from Viçosa, Minas Gerais, Brazil, as a probiotic. A suspension containing 10(8) cells of Lactobacillus acidophilus UFV-H2b20 was inoculated into groups of at least five conventional and germfree Swiss mice to determine its capacity to stimulate the host mononuclear phagocytic activity. We demonstrate that this strain can survive the stressing conditions of the intestinal tract in vivo. Moreover, the monoassociation of germfree mice with this strain for seven days improved the host's macrophage phagocytic capacity, as demonstrated by the clearance of a Gram-negative bacterium inoculated intravenously. Monoassociated mice showed an undetectable number of circulating E. coli, while 0.1% of the original inoculum was still present in germfree animals. Mice treated with viable or heat-killed Lactobacillus acidophilus UFV-H2b20 presented similarly improved clearance capacity when compared with germfree controls. In addition, monoassociated mice had twice the amount of Kupffer cells, which are responsible for the clearance of circulating bacteria, compared to germfree controls. These results suggest that the L. acidophilus strain used here stimulates a nonspecific immune response and is a strong candidate to be used as a probiotic.
Asunto(s)
Sistema Digestivo/inmunología , Sistema Digestivo/microbiología , Vida Libre de Gérmenes , Lactobacillus acidophilus/inmunología , Probióticos , Animales , Macrófagos del Hígado/metabolismo , Hígado/citología , Macrófagos , RatonesRESUMEN
Protection of lung elastin fibers from proteolytic destruction is compromised by inefficient secretion of incompletely folded allelic variants of human alpha1-antitrypsin from hepatocytes. Pulse-chase radiolabeling with [35S]methionine and sucrose gradient sedimentation and coimmunoprecipitation techniques were employed to investigate quality control of human alpha1-antitrypsin secretion from stably transfected mouse hepatoma cells. The secretion-incompetent variant null(Hong Kong) (Sifers, R. N., Brashears-Macatee, S., Kidd, V. J., Muensch, H., and Woo, S. L. C. (1988) J. Biol. Chem. 263, 7330-7335) cannot fold into a functional conformation and was quantitatively associated with the molecular chaperone calnexin following biosynthesis. Assembly with calnexin required cotranslational trimming of glucose from asparagine-linked oligosaccharides. Intracellular disposal of pulse-radiolabeled molecules coincided with their release from calnexin. Released monomers and intracellular disposal were nonexistent in cells chased with cycloheximide, an inhibitor of protein synthesis. Post-translational trimming of asparagine-linked oligosaccharides and intracellular disposal were abrogated by 1-deoxymannojirimycin, an inhibitor of alpha-mannosidase activity, without affecting the monomer population. The data are consistent with a recently proposed quality control model (Hammond, C., Braakman, I., and Helenius, A. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 913-917) in which intracellular disposal requires dissociation from calnexin and post-translational trimming of mannose from asparagine-linked oligosaccharides.
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Asparagina/metabolismo , Proteínas de Unión al Calcio/metabolismo , Oligosacáridos/metabolismo , Procesamiento Proteico-Postraduccional , alfa 1-Antitripsina/metabolismo , 1-Desoxinojirimicina/farmacología , Animales , Calnexina , Glucosa/metabolismo , Humanos , Ratones , Pliegue de Proteína , Células Tumorales CultivadasAsunto(s)
Humanos , Masculino , Femenino , Anticuerpos Antivirales/análisis , Antígenos Virales/inmunología , VIH/inmunología , Reacciones Antígeno-Anticuerpo , Ensayo de Inmunoadsorción Enzimática , Técnica del Anticuerpo Fluorescente , Hemofilia A , Homosexualidad , Paraguay , Trabajo Sexual , Grupos de Riesgo , Trastornos Relacionados con SustanciasRESUMEN
We investigated the distribution of autologous rosette forming cells (ARFC) in the peripheral blood from subjects at risk for the acquired immunodeficiency syndrome (AIDS). The mean percentage of ARFC with autologous plasma from 35 male homosexual individuals was significantly lower than that of 31 normal controls. The mean percentage of ARFC of SARA had a direct linear correlation with the percentage of T4+ cells (p less than 0.01). Within the SARA group, those with antibodies against HTLV-III/LAV had percentages of ARFC significantly lower than SARA with negative antibodies. Plasma from SARA decreased the percentage of ARFC of normal cells when compared to normal homologous plasma (p less than 0.005), whereas normal homologous plasma did not modify the low percentage of ARFC from SARA. These results indicate that SARA possess a depletion of this subpopulation of T cells. This is more pronounced in subjects with anti-HTLV-III/LAV antibodies. The low ARFC is related to a decrease in the number of cells that correlates with the number of T4+ cells. The inhibition of normal ARFC by plasma from SARA suggests the existence of plasma factors that could mask the lymphocyte receptors for their own red blood cells and/or coat erythrocytes preventing lymphocyte-erythrocyte binding.