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1.
J Stomatol Oral Maxillofac Surg ; 122(1): 88-97, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32622000

RESUMO

This systematic review aimed to evaluate the accuracy of customized titanium plates in orthognathic surgery compared to standard outcome in virtual surgical planning. PRISMA and JBI guidelines were followed. Research protocol was registered in PROSPERO. Six databases and two gray literature repositories were used as sources of research articles. Descriptive clinical studies, that performed orthognathic surgery using custom titanium plates, were included. Risk of bias was assessed by "The Joanna-Briggs Institute Critical Appraisal tools for use in Systematic Reviews Checklist for Case Series". Of the 11,916 studies initially identified, seven met the eligibility criteria and were included. The studies were published between 2015 and 2019. Most of the studies (57%) had a low risk of bias, while one had a high risk of bias. Total sample included 74 patients with 63 bimaxillary surgeries and 11 unimaxillary surgeries. All studies showed acceptable accuracy within previously established clinical parameters. Although the eligible articles assessed the accuracy of the orthognathic surgery with respect to virtual planning, the wide variability of evaluation methodologies made it impossible to calculate a combined accuracy measure. It was not possible to perform a meta-analysis, so a pragmatic recommendation on the use of these plates is not possible.


Assuntos
Cirurgia Ortognática , Procedimentos Cirúrgicos Ortognáticos , Placas Ósseas , Humanos , Titânio
2.
Braz. j. med. biol. res ; 51(1): e5427, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-889002

RESUMO

Protocols that mimic resistance exercise training (RET) in rodents present several limitations, one of them being the electrical stimulus, which is beyond the physiological context observed in humans. Recently, our group developed a conditioning system device that does not use electric shock to stimulate rats, but includes fasting periods before each RET session. The current study was designed to test whether cumulative fasting periods have some influence on skeletal muscle mass and function. Three sets of male Wistar rats were used in the current study. The first set of rats was submitted to a RET protocol without food restriction. However, rats were not able to perform exercise properly. The second and third sets were then randomly assigned into three experimental groups: 1) untrained control rats, 2) untrained rats submitted to fasting periods, and 3) rats submitted to RET including fasting periods before each RET session. While the second set of rats performed a short RET protocol (i.e., an adaptation protocol for 3 weeks), the third set of rats performed a longer RET protocol including overload (i.e., 8 weeks). After the short-term protocol, cumulative fasting periods promoted loss of weight (P<0.001). After the longer RET protocol, no difference was observed for body mass, extensor digitorum longus (EDL) morphology or skeletal muscle function (P>0.05 for all). Despite no effects on EDL mass, soleus muscle displayed significant atrophy in the fasting experimental groups (P<0.01). Altogether, these data indicate that fasting is a major limitation for RET in rats.


Assuntos
Animais , Masculino , Condicionamento Físico Animal/fisiologia , Jejum/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Valores de Referência , Fatores de Tempo , Peso Corporal/fisiologia , Adaptação Fisiológica , Distribuição Aleatória , Ingestão de Alimentos/fisiologia
3.
Braz J Med Biol Res ; 51(1): e5427, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-29185588

RESUMO

Protocols that mimic resistance exercise training (RET) in rodents present several limitations, one of them being the electrical stimulus, which is beyond the physiological context observed in humans. Recently, our group developed a conditioning system device that does not use electric shock to stimulate rats, but includes fasting periods before each RET session. The current study was designed to test whether cumulative fasting periods have some influence on skeletal muscle mass and function. Three sets of male Wistar rats were used in the current study. The first set of rats was submitted to a RET protocol without food restriction. However, rats were not able to perform exercise properly. The second and third sets were then randomly assigned into three experimental groups: 1) untrained control rats, 2) untrained rats submitted to fasting periods, and 3) rats submitted to RET including fasting periods before each RET session. While the second set of rats performed a short RET protocol (i.e., an adaptation protocol for 3 weeks), the third set of rats performed a longer RET protocol including overload (i.e., 8 weeks). After the short-term protocol, cumulative fasting periods promoted loss of weight (P<0.001). After the longer RET protocol, no difference was observed for body mass, extensor digitorum longus (EDL) morphology or skeletal muscle function (P>0.05 for all). Despite no effects on EDL mass, soleus muscle displayed significant atrophy in the fasting experimental groups (P<0.01). Altogether, these data indicate that fasting is a major limitation for RET in rats.


Assuntos
Jejum/fisiologia , Músculo Esquelético/fisiologia , Condicionamento Físico Animal/fisiologia , Treinamento Resistido/métodos , Adaptação Fisiológica , Animais , Peso Corporal/fisiologia , Ingestão de Alimentos/fisiologia , Masculino , Distribuição Aleatória , Ratos Wistar , Valores de Referência , Fatores de Tempo
5.
Scand J Med Sci Sports ; 27(11): 1240-1247, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27882605

RESUMO

We investigated the effects of supplement identification on exercise performance with caffeine supplementation. Forty-two trained cyclists (age 37 ± 8 years, body mass [BM] 74.3 ± 8.4 kg, height 1.76 ± 0.06 m, maximum oxygen uptake 50.0 ± 6.8 mL/kg/min) performed a ~30 min cycling time-trial 1 h following either 6 mg/kgBM caffeine (CAF) or placebo (PLA) supplementation and one control (CON) session without supplementation. Participants identified which supplement they believed they had ingested ("caffeine", "placebo", "don't know") pre- and post-exercise. Subsequently, participants were allocated to subgroups for analysis according to their identifications. Overall and subgroup analyses were performed using mixed-model and magnitude-based inference analyses. Caffeine improved performance vs PLA and CON (P ≤ 0.001). Correct pre- and post-exercise identification of caffeine in CAF improved exercise performance (+4.8 and +6.5%) vs CON, with slightly greater relative increases than the overall effect of caffeine (+4.1%). Performance was not different between PLA and CON within subgroups (all P > 0.05), although there was a tendency toward improved performance when participants believed they had ingested caffeine post-exercise (P = 0.06; 87% likely beneficial). Participants who correctly identified placebo in PLA showed possible harmful effects on performance compared to CON. Supplement identification appeared to influence exercise outcome and may be a source of bias in sports nutrition.


Assuntos
Ciclismo/fisiologia , Cafeína/farmacologia , Suplementos Nutricionais , Substâncias para Melhoria do Desempenho/farmacologia , Adulto , Desempenho Atlético , Cafeína/administração & dosagem , Método Duplo-Cego , Teste de Esforço , Humanos , Masculino , Consumo de Oxigênio , Substâncias para Melhoria do Desempenho/administração & dosagem , Estudo de Prova de Conceito , Fenômenos Fisiológicos da Nutrição Esportiva
6.
Braz. j. med. biol. res ; 49(3): e4435, Mar. 2016. tab
Artigo em Inglês | LILACS | ID: lil-771935

RESUMO

The autonomic nervous system maintains homeostasis, which is the state of balance in the body. That balance can be determined simply and noninvasively by evaluating heart rate variability (HRV). However, independently of autonomic control of the heart, HRV can be influenced by other factors, such as respiratory parameters. Little is known about the relationship between HRV and spirometric indices. In this study, our objective was to determine whether HRV correlates with spirometric indices in adults without cardiopulmonary disease, considering the main confounders (e.g., smoking and physical inactivity). In a sample of 119 asymptomatic adults (age 20-80 years), we evaluated forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). We evaluated resting HRV indices within a 5-min window in the middle of a 10-min recording period, thereafter analyzing time and frequency domains. To evaluate daily physical activity, we instructed participants to use a triaxial accelerometer for 7 days. Physical inactivity was defined as <150 min/week of moderate to intense physical activity. We found that FVC and FEV1, respectively, correlated significantly with the following aspects of the RR interval: standard deviation of the RR intervals (r =0.31 and 0.35), low-frequency component (r =0.38 and 0.40), and Poincaré plot SD2 (r =0.34 and 0.36). Multivariate regression analysis, adjusted for age, sex, smoking, physical inactivity, and cardiovascular risk, identified the SD2 and dyslipidemia as independent predictors of FVC and FEV1 (R2=0.125 and 0.180, respectively, for both). We conclude that pulmonary function is influenced by autonomic control of cardiovascular function, independently of the main confounders.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Frequência Cardíaca/fisiologia , Pulmão/fisiologia , Fumar/fisiopatologia , Sistema Nervoso Autônomo/fisiologia , Estudos Transversais , Dislipidemias/fisiopatologia , Volume Expiratório Forçado/fisiologia , Comportamento Sedentário , Espirometria , Capacidade Vital/fisiologia
7.
Braz J Med Biol Res ; 49(3)2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26840706

RESUMO

The autonomic nervous system maintains homeostasis, which is the state of balance in the body. That balance can be determined simply and noninvasively by evaluating heart rate variability (HRV). However, independently of autonomic control of the heart, HRV can be influenced by other factors, such as respiratory parameters. Little is known about the relationship between HRV and spirometric indices. In this study, our objective was to determine whether HRV correlates with spirometric indices in adults without cardiopulmonary disease, considering the main confounders (e.g., smoking and physical inactivity). In a sample of 119 asymptomatic adults (age 20-80 years), we evaluated forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). We evaluated resting HRV indices within a 5-min window in the middle of a 10-min recording period, thereafter analyzing time and frequency domains. To evaluate daily physical activity, we instructed participants to use a triaxial accelerometer for 7 days. Physical inactivity was defined as <150 min/week of moderate to intense physical activity. We found that FVC and FEV1, respectively, correlated significantly with the following aspects of the RR interval: standard deviation of the RR intervals (r =0.31 and 0.35), low-frequency component (r =0.38 and 0.40), and Poincaré plot SD2 (r =0.34 and 0.36). Multivariate regression analysis, adjusted for age, sex, smoking, physical inactivity, and cardiovascular risk, identified the SD2 and dyslipidemia as independent predictors of FVC and FEV1 (R2=0.125 and 0.180, respectively, for both). We conclude that pulmonary function is influenced by autonomic control of cardiovascular function, independently of the main confounders.


Assuntos
Frequência Cardíaca/fisiologia , Pulmão/fisiologia , Comportamento Sedentário , Fumar/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Sistema Nervoso Autônomo/fisiologia , Fatores de Confusão Epidemiológicos , Estudos Transversais , Dislipidemias/fisiopatologia , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Espirometria , Capacidade Vital/fisiologia
8.
Community Dent Health ; 29(1): 25-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22482245

RESUMO

OBJECTIVE: To evaluate the reproducibility of caries detection and treatment planning among public health dentists and estimate the possible impact of their decisions on financial costs. RESEARCH DESIGN AND SETTINGS: Thirty nine dentists working in the public health service of Piracicaba, São Paulo, Brazil made a combined visual-radiographic caries examination of 40 occlusal surfaces of extracted permanent teeth mounted on two dental mannequins and proposed treatment plans for each tooth. Histological validation then evaluated the diagnoses validity and the suitability of the treatment plans. OUTCOME MEASURES: Inter-examiner agreement was calculated by Cohen's Kappa statistics. The sensitivity and specificity of caries detection and treatment decision were calculated. The costs of dental treatment plans for public health system were calculated from a Brazilian public health service fee scale. RESULTS: Inter-examiner agreement for caries detection was moderate (kappa = 0.42) while for treatment decisions it was fair (kappa = 0.29). The sensitivity and specificity were 0.69 and 0.65 for caries detection and 0.56 and 0.65 for treatment decision respectively. Dentists overestimated the presence and depth of carious lesions and there was a tendency to treat enamel lesions using invasive therapeutic procedures. Mean treatment cost across the two cases was 32US$ (range 9-65) while the histologically validated cost was 23US$. CONCLUSION: The variability in caries detection and treatment decision negatively affected the cost of the dental treatment.


Assuntos
Assistência Odontológica/economia , Cárie Dentária/diagnóstico , Planejamento de Assistência ao Paciente , Dente Pré-Molar/patologia , Brasil , Resinas Compostas/economia , Tomada de Decisões , Amálgama Dentário/economia , Tratamento Dentário Restaurador sem Trauma/economia , Cárie Dentária/patologia , Cárie Dentária/terapia , Esmalte Dentário/patologia , Materiais Dentários/economia , Restauração Dentária Permanente/economia , Dentina/patologia , Fluoretos Tópicos/economia , Fluoretos Tópicos/uso terapêutico , Cimentos de Ionômeros de Vidro/economia , Custos de Cuidados de Saúde , Humanos , Dente Molar/patologia , Variações Dependentes do Observador , Planejamento de Assistência ao Paciente/economia , Selantes de Fossas e Fissuras/economia , Selantes de Fossas e Fissuras/uso terapêutico , Odontologia em Saúde Pública/economia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Conduta Expectante/economia , Adulto Jovem
9.
Int J Dent Hyg ; 9(4): 250-3, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21689374

RESUMO

OBJECTIVE: Early dental caries diagnosis within the changing global pattern of dental caries development requires the use of auxiliary resources and adjuncts to diagnosis. The aim of this study was to introduce an alternative resource for drying teeth to enable early diagnosis of dental caries in epidemiological surveys. METHODS: Polyurethane tips and three-in-one syringes were fitted to nebulizers and non-professional portable compressors for dental surface drying. The output air pressure of these sets was compared with the output pressure from the three-in-one syringe in a dental office. RESULTS: Although the output pressure from the alternative resources was lower than the output pressure from the dental office equipment, the dental surfaces were dried satisfactorily, allowing the early diagnosis of the dental caries. CONCLUSION: When a dental setting is not available, these alternative resources for drying teeth can be used satisfactorily.


Assuntos
Cárie Dentária/diagnóstico , Dessecação/métodos , Pressão do Ar , Brasil/epidemiologia , Criança , Pré-Escolar , Ar Comprimido , Índice CPO , Cárie Dentária/epidemiologia , Equipamentos Odontológicos , Inquéritos de Saúde Bucal , Dessecação/instrumentação , Métodos Epidemiológicos , Humanos , Nebulizadores e Vaporizadores , Fatores Socioeconômicos
10.
Cell Prolif ; 43(6): 529-41, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21039991

RESUMO

OBJECTIVES: Clonal kidney cells (Vero cells) are extensively utilized in the manufacture of biological preparations for disease diagnostics and therapeutics and also in preparation of vaccines. In all cells, regulation of volume is an essential function coupled to a variety of physiological processes and is a topic of interest. The objective here was to investigate involvement of ion channels in the process of volume regulation of Vero cells. METHODS: Involvement of ion channels in cell volume regulation was studied using video-microscopy and flow cytometry. Pharmacologically unaltered cells of different sizes, which are presumably at different phases of the cell cycle, were used. RESULTS: Ion transport inhibitors altered all phases of regulatory volume decrease (RVD) of Vero cells, rate of initial cell swelling, V(max) and volume recovery. Effects were dependent on type of inhibitor and on cell size (cell cycle phase). Participation of aquaporins in RVD was suggested. Inhibitors decelerated growth, arresting Vero cells at the G(0) /G(1) phase boundary. Electrophysiological study confirmed presence of volume-activated Cl(-) channels and K(+) channels in plasmatic membranes of the cells. CONCLUSION: Vero cells of all sizes maintained the ability to recover from osmotic swelling. Activity of ion channels was one of the key factors that controlled volume regulation and proliferation of the cells.


Assuntos
Tamanho Celular , Canais Iônicos/metabolismo , Rim/citologia , Rim/metabolismo , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Animais , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Chlorocebus aethiops , Citometria de Fluxo , Glibureto/farmacologia , Canais Iônicos/antagonistas & inibidores , Microscopia , Nitrobenzoatos/farmacologia , Tetraetilamônio/farmacologia , Células Vero
11.
Exp Parasitol ; 103(3-4): 152-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12880592

RESUMO

Leishmania metacyclogenesis is associated with changes in morphology, gene expression, and structural alterations of the lipophosphoglycan (LPG), the promastigote most abundant surface glycolipid. Purification of metacyclics is accomplished using lectins or monoclonal antibodies (MAbs) that exploit stage-specific differences in the LPG. Besides, LPG displays extensive interspecies polymorphisms and is synthesized by promastigotes of all species investigated to date. In this work we studied the species- and stage-specificity of two MAbs (3A1-La and LuCa-D5) used to purify metacyclics of Leishmania amazonensis. Their ability to recognize different members of the Trypanosomatidae family was tested by direct agglutination, indirect immunofluorescence, and dot-blot analysis of LPG. We found that both MAbs were highly selective for L. amazonensis: 3A1-La recognized only promastigotes and LuCa-D5 labeled amastigote and promastigote stages of this species. These MAbs might be useful for Leishmania typing.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antiprotozoários/imunologia , Especificidade de Anticorpos , Leishmania/classificação , Leishmania/crescimento & desenvolvimento , Testes de Aglutinação , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Antiprotozoários/biossíntese , Imunofluorescência , Glicoesfingolipídeos/imunologia , Humanos , Immunoblotting , Leishmania/imunologia , Estágios do Ciclo de Vida , Camundongos , Camundongos Endogâmicos BALB C , Especificidade da Espécie , Trypanosomatina/classificação , Trypanosomatina/imunologia
12.
Eur J Immunol ; 31(6): 1857-66, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11433382

RESUMO

The macrophage mannose receptor (MR) has an established role in the phagocytosis of a wide range of microbes, and also functions in viral endocytosis, and clearance of a number of endogenous glycoproteins from the circulation. Its broad ligand specificity is mediated by tandemly linked carbohydrate recognition domains (CRDs). Recent studies suggest that binding or internalization of both natural and synthetic ligands of MR CRDs may modulate macrophage (MPhi ) function, for example to increase cidal capacity or cytokine synthesis. To identify endogenous ligands in the normal mouse we used an Fc-fusion protein (CRD4-7Fc) bearing four of the CRDs of MR. CRD4-7Fc recognized endocytic compartments of cultured MPhi, consistent with lysosomal enzymes being major ligands of MR. CRD4-7Fc also recognized MPhi and some endothelial cells in tissues, and intensely labeled secretory cells of the exocrine pancreas, salivary gland and thyroid. Strongly MR-positive interstitial cells were found in close proximity to the ligand-rich secretory cells, suggesting a role for MR in uptake of secretory glycoproteins, including thyroglobulin which was identified as a novel ligand in vitro. Endocytosis of these ligands by MR may have implications for tissue homeostasis and immunity, including antigen presentation, in secretory organs.


Assuntos
Metabolismo dos Carboidratos , Lectinas Tipo C , Lectinas de Ligação a Manose , Receptores de Superfície Celular/metabolismo , Animais , Sítios de Ligação , Células Cultivadas , Endocitose , Endotélio/citologia , Humanos , Ligantes , Macrófagos/citologia , Macrófagos/metabolismo , Receptor de Manose , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Receptores de Superfície Celular/genética , Receptores Fc/genética , Receptores Fc/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
13.
J Cell Sci ; 112 ( Pt 19): 3237-48, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10504329

RESUMO

Candida albicans is an important opportunistic pathogen, whose interaction with cells of the immune system, in particular macrophages (MO), is poorly understood. In order to learn more about the nature of the infectious mechanism, internalisation of Candida albicans was studied in mouse MO by confocal immunofluorescence and electron microscopy in comparison with latex beads of similar size, which were coated with mannosyl-lipoarabinomannan (ManLAM) to target the MO mannose receptor (MR). Uptake of Candida yeasts had characteristics of phagocytosis, required intact actin filaments, and depended on the activity of protein kinase C (PKC). Candida phagosomes rapidly attracted lysosome-associated membrane protein (Lamp)-rich vacuoles, indicative of fusion with late endosomes and lysosomes. Rapid recruitment of late endosomes and lysosomes could be observed regardless of heat-inactivation or serum-opsonisation of Candida, but did not follow binding of the mannosylated-beads to MO, which suggest that this phenotype is not MR-specific. The yeasts developed germ tubes within phagolysosomes, distended their membranes and escaped, destroying the non-activated MO. The filamentous form of Candida could penetrate intact MO even when phagocytosis was blocked, and also attracted Lamp-rich organelles. Inhibition of lysosomal acidification and associated lysosomal fusion reduced germ tube formation of Candida within the phagolysosomes. These data suggest that rapid recruitment of late endocytic/lysosomal compartments by internalizing C. albicans favours survival and virulence of this pathogen.


Assuntos
Candida albicans/crescimento & desenvolvimento , Candidíase/imunologia , Endossomos/fisiologia , Lisossomos/fisiologia , Macrófagos Peritoneais/microbiologia , Ácidos/farmacologia , Animais , Candida albicans/citologia , Candida albicans/ultraestrutura , Moléculas de Adesão Celular Neuronais/análise , Divisão Celular/efeitos dos fármacos , Endossomos/ultraestrutura , Feminino , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Proteínas Ligadas por GPI , Concentração de Íons de Hidrogênio , Lisossomos/ultraestrutura , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica , Microesferas , Fagossomos/química , Fagossomos/fisiologia , Fagossomos/ultraestrutura , Xantenos
14.
J Immunol ; 162(8): 4606-13, 1999 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10202000

RESUMO

Cytokine regulation of endocytic activity in primary human macrophages was studied to define ultrastructural changes and mechanisms of pinocytic regulation associated with cytokines secreted by activated T cells. The effects of IFN-gamma (type 1) and IL-4/IL-13 and IL-10 (type 2) cytokines on fluid phase and mannose receptor-mediated endocytosis were assessed by horseradish peroxidase and colloidal gold-BSA uptake and computer-assisted morphometric analysis. IL-4 and IL-13 enhanced fluid phase pinocytosis and mannose receptor-mediated uptake by activation of phosphatidylinositol 3-kinase. Inhibition of actin assembly showed that both cytokines exerted actin-dependent and -independent effects. Ultrastructurally, IL-4 and IL-13 increased tubular vesicle formation underneath the plasma membrane and at pericentriolar sites, concurrent with decreased particle sorting to lysosomes. By contrast, IL-10 or IFN-gamma decreased both fluid phase pinocytosis and mannose receptor-mediated uptake. IFN-gamma stimulated increased particle sorting to perinuclear lysosomes, while IL-10 decreased this activity. In summary, our data document differential effects on macrophage endocytic functions by type 1 or type 2 cytokines associated with induction and effector pathways in immunity.


Assuntos
Endocitose/imunologia , Interferon gama/fisiologia , Interleucina-10/fisiologia , Interleucina-13/fisiologia , Interleucina-4/fisiologia , Lectinas Tipo C , Ativação de Macrófagos/imunologia , Lectinas de Ligação a Manose , Células Th1/metabolismo , Células Th2/metabolismo , Actinas/metabolismo , Actinas/fisiologia , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Endossomos/enzimologia , Endossomos/ultraestrutura , Coloide de Ouro , Complexo de Golgi/metabolismo , Complexo de Golgi/ultraestrutura , Peroxidase do Rábano Silvestre/metabolismo , Humanos , Lisossomos/enzimologia , Lisossomos/metabolismo , Lisossomos/ultraestrutura , Macrófagos/enzimologia , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Receptor de Manose , Fosfatidilinositol 3-Quinases/fisiologia , Receptores de Superfície Celular/fisiologia , Células Th1/imunologia , Células Th2/imunologia
15.
Immunol Lett ; 65(1-2): 15-9, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10065621

RESUMO

Apoptotic cells are rarely seen in situ because of rapid clearance by phagocytes. A number of receptors have been implicated in the recognition and ingestion of dying cells. Class A scavenger receptors (SRs) are multi-domained membrane glycoproteins that can endocytose modified lipoproteins and bind a wide range of ligands. There is growing evidence that they contribute to several biological processes. We present data that suggest class A SRs are involved in the phagocytosis of apoptotic cells.


Assuntos
Apoptose/imunologia , Macrófagos/imunologia , Fagocitose/fisiologia , Receptores Imunológicos/fisiologia , Animais , Camundongos , Receptores Imunológicos/metabolismo , Receptores Depuradores , Receptores Depuradores Classe A
16.
Biochem J ; 338 ( Pt 3): 687-94, 1999 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10051440

RESUMO

Macrosialin (mouse CD68), a macrophage-specific member of the lysosomal-associated membrane protein family, displays N-linked glycosylation and a heavily sialylated, mucin-like domain. We show that phagocytosis of zymosan by inflammatory peritoneal macrophages potently alters glycan processing of macrosialin in vitro. The phagocytic glycoform is not induced by other forms of endocytosis and depends on particle internalization. Zymosan uptake does not influence macrosialin protein synthesis, but increases the specific incorporation of D-[2-3H]mannose, D-[6-3H]galactose, N-acetyl-D-[1-3H]glucosamine and L-[5,6-3H]fucose by 2-15-fold. The phagocytic glycoform displays increased binding of agglutinins from peanut, Amaranthus caudatus and Galanthus nivalis, whereas binding of the sialic-acid-specific Maakia amurensis agglutinin is slightly reduced. Digestion by N-Glycanase abolishes the incorporation of [3H]mannose label and Galanthus nivalis agglutinin binding activity, but preserves the incorporation of galactose and N-acetylglucosamine and specific lectin binding. We also show that phagocytosis increases the complexity and length of O-linked chains. The data presented highlight the importance of differential glycosylation in the biology of macrosialin, phagosomes and macrophages in general.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Fagocitose , Animais , Sequência de Carboidratos , Endocitose , Galanthus , Glicosilação , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Camundongos , Dados de Sequência Molecular , Polissacarídeos/química , Polissacarídeos/metabolismo
17.
Eur J Immunol ; 28(11): 3639-47, 1998 11.
Artigo em Inglês | MEDLINE | ID: mdl-9842906

RESUMO

In cell lines the endocytic properties of CD4 are regulated through its association with the src-family tyrosine kinase p56lck. In lymphoid cell lines expressing p56lck, CD4 is restricted to the cell surface and undergoes only limited internalization. Phosphorylation of the cytoplasmic domain of CD4 causes p56lck to dissociate and activates an endocytosis signal leading to the internalization of CD4 through clathrin-coated pits. In p56lck-negative transfected cell lines CD4 is constitutively internalized, but internalization is inhibited when p56lck is expressed in these cells. We now demonstrate that these endocytic properties of CD4 determined in transfected cell lines hold true for CD4 naturally expressed on myeloid cell lines (HL-60 and U937), as well as on primary lymphocytes, monocytes and macrophages isolated from human blood. CD4 showed limited internalization on p56lck-positive lymphocytes, but was rapidly internalized in p56lck-negative monocytes and macrophages. Surprisingly, rapid internalization of CD4 was seen with the lymphocytes from one unidentified donor. In these cells we failed to detect p56lck expression by Western blotting.


Assuntos
Antígenos CD4/metabolismo , Endocitose , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/fisiologia , Linfócitos/metabolismo , Macrófagos/metabolismo , Monócitos/metabolismo , Animais , Linhagem Celular , Humanos , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/análise , Camundongos
18.
Trends Cell Biol ; 8(9): 365-72, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9728398

RESUMO

Although apoptotic cell death is widespread, dying cells are rarely seen in situ because of their rapid clearance by neighbouring phagocytes. Phagocytic recognition of apoptotic cells is less well understood than the death programme itself, but an increasing number of recent studies are highlighting its importance. This review discusses the nature of the receptors that have been implicated in apoptotic cell phagocytosis, the mechanisms of uptake and the immunological consequences of apoptotic cell ingestion.


Assuntos
Apoptose , Proteínas de Membrana , Fagocitose , Receptores Imunológicos/fisiologia , Receptores de Lipoproteínas , Animais , Antígenos CD36/fisiologia , Receptores Depuradores , Receptores Depuradores Classe B
20.
Biochem J ; 322 ( Pt 2): 411-5, 1997 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-9065757

RESUMO

Rat liver Kupffer cell membranes contain a protein that recognizes specifically oxidized low-density lipoproteins (oxLDL). Visualization after blotting under reducing conditions indicates that the receptor is a monomeric protein, with an estimated molecular mass of 115-120 kDa. N-Glycosidase F and endoglycosidase F treatment resulted in a fall in estimated molecular mass of 24 and 11 kDa respectively, whereas O-glycosidase was ineffective. No effect on the extent of interaction with oxLDL was noticed, suggesting that glycans are not essential for ligand recognition. Using a polyclonal antibody to mouse macrosialin, we visualized macrosialin on blot, and compared this glycoprotein with the oxLDL-binding protein. It appears that the two glycoproteins have a similar molecular mass and are comparably affected by treatment with the different glycosidases. Incubation with trypsin resulted in a reduction in the estimated molecular mass of about 25 kDa for both the oxLDL-binding protein and macrosialin. These results indicate that the oxLDL-binding protein and macrosialin are identical, suggesting a role for macrosialin in modified LDL catabolism.


Assuntos
Antígenos CD , Antígenos de Diferenciação Mielomonocítica , Células de Kupffer/química , Fígado/química , Glicoproteínas de Membrana/isolamento & purificação , Receptores de LDL/isolamento & purificação , Animais , Reações Cruzadas , Glicosídeo Hidrolases/farmacologia , Humanos , Immunoblotting , Células de Kupffer/citologia , Fígado/citologia , Masculino , Glicoproteínas de Membrana/efeitos dos fármacos , Glicoproteínas de Membrana/imunologia , Camundongos , Oxirredução , Ratos , Ratos Wistar , Receptores de LDL/efeitos dos fármacos , Receptores de LDL/imunologia , Receptores de LDL Oxidado , Receptores Depuradores Classe E , Tripsina/farmacologia
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