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1.
Clin Nephrol ; 90(5): 341-349, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30148449

RESUMO

BACKGROUND: Limited reports are available on the role of 4% citrate as a locking solution for temporary dialysis catheters. Hence, the aim of this study is to investigate the role of 4% citrate vs. heparin 5,000 µ/mL as a catheter-locking solution in a randomized controlled trial. MATERIALS AND METHODS: The trial was conducted in Egypt where the use of non-tunneled temporary catheters is prevalent compared to tunneled long-term catheters. The efficacy of catheter-locking solutions was compared regarding observation of rate of catheter dysfunction, low-flow pump, fever as a sign of central-line blood-stream infection (CLBSI), catheter-site infection, thrombosis, local bleeding, and systemic bleeding in each group of the study. RESULTS: Each group consisted of 105 patients. The number of patients who developed CLBSI in the citrate group was 11 (10.5%) compared to 23 (21.9%) in the heparin group (p < 0.025). The number of patients who developed catheter dysfunction in the citrate group was similar to those in the heparin group. The incidence of catheter-site infection, thrombosis, and local bleeding in the citrate group was similar to that in the heparin group. CONCLUSION: Citrate 4% lock solution is equally effective as heparin in maintaining catheter patency in dialysis patients. It may have a favorable effect on prevention of catheter-related infection due to its additional antiseptic properties as compared to heparin. Citrate-based locking solutions are a promising alternative to unfractionated heparin as a locking solution for dialysis catheters.
.


Assuntos
Infecções Relacionadas a Cateter , Cateterismo , Heparina , Diálise Renal , Citrato de Sódio , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/prevenção & controle , Cateterismo/efeitos adversos , Cateterismo/métodos , Cateterismo/estatística & dados numéricos , Heparina/efeitos adversos , Heparina/uso terapêutico , Humanos , Diálise Renal/efeitos adversos , Diálise Renal/métodos , Diálise Renal/estatística & dados numéricos , Citrato de Sódio/efeitos adversos , Citrato de Sódio/uso terapêutico
2.
J Pharm Bioallied Sci ; 11(2): 148-154, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31148891

RESUMO

OBJECTIVE: Hyperphosphatemia in end-stage renal disease (ESRD) is associated with many serious patient-level consequences including cardiovascular events and mortality. The purpose of this study was to investigate the use of phosphate binders in ESRD patients on maintenance hemodialysis. MATERIALS AND METHODS: The study was a prospective observational cohort study including adult ESRD patients undergoing hemodialysis at a secondary hospital in United Arab Emirates. Patient characteristics were compared as per type of phosphate binder used. Bivariate and multivariate multinomial logistic regression analyses were carried out to determine variables that were independently associated with use of different phosphate binders. RESULTS: Phosphate binders used at our study site were sevelamer, calcium carbonate, and a combination of sevelamer and calcium carbonate. Bivariate multinomial logistic regression analysis revealed that serum phosphorous (odds ratio [OR]: 0.14, 95% confidence interval [CI]: 0.04-1.09, P = 0.047; OR: 0.10, 95% CI: 0.03-0.89, P = 0.042), calcium (OR: 0.11, 95% CI: 0.02-0.86, P = 0.041; OR: 0.22, 95% CI: 0.01-0.96, P = 0.012), and calcium-phosphorous product (OR: 0.20, 95% CI: 0.06-0.64, P = 0.008; OR: 0.16, 95% CI: 0.05-0.54, P = 0.003) levels were significantly lower in patients on sevelamer per se as well as in patients on combination therapy, respectively when compared to calcium carbonate per se. Multivariate multinomial logistic regression analysis revealed that in sevelamer and combination groups, cardiovascular diseases (OR: 0.12, 95% CI: 0.02-0.65, P = 0.022; OR: 0.10, 95% CI: 0.01-0.88, P = 0.038) were significantly lesser compared to calcium carbonate group after being adjusted for other variables in the model. CONCLUSION: We observed that hyperphosphatemia and related events in our study population were better controlled by sevelamer per se and combination therapy than calcium carbonate per se. Further large scale, multicenter studies are required to confirm and establish these findings.

3.
J Chromatogr A ; 1524: 222-232, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-28992991

RESUMO

The gas industry is going to be revolutionized by being able to generate bioenergy from biomass. The production of biomethane - a green substitute of natural gas - is growing in Europe and the United-States of America. Biomethane can be injected into the gas grid or used as fuel for vehicles after compression. Due to various biomass inputs (e.g. agricultural wastes, sludges from sewage treatment plants, etc.), production processes (e.g. anaerobic digestion, municipal solid waste (MSW) landfills), seasonal effects and purification processes (e.g. gas scrubbers, pressure swing adsorption, membranes for biogas upgrading), the composition and quality of biogas and biomethane produced is difficult to assess. All previous publications dealing with biogas analysis reported that hundreds of chemicals from ten chemical families do exist in trace amounts in biogas. However, to the best of our knowledge, no study reported a detailed analysis or the implementation of comprehensive two-dimensional gas chromatography (GC×GC) for biogas matrices. This is the reason why the benefit of implementing two-dimensional gas chromatography for the characterization of biogas and biomethane samples was evaluated. In a first step, a standard mixture of 89 compounds belonging to 10 chemical families, representative of those likely to be found, was used to optimize the analytical method. A set consisting of a non-polar and a polar columns, respectively in the first and the second dimension, was used with a modulation period of six seconds. Applied to ten samples of raw biogas, treated biogas and biomethane collected on 4 industrial sites (two MSW landfills, one anaerobic digester on a wastewater treatment plant and one agricultural biogas plant), this analytical method provided a "fingerprint" of the gases composition at the molecular level in all biogas and biomethane samples. Estimated limits of detection (far below the µgNm-3) coupled with the resolution of GC×GC allowed the comparison of the real samples considered. This first implementation of GC×GC for the analysis of biogas and biomethane demonstrated unambiguously that it is a promising tool to provide a "fingerprint" of samples, and to monitor trace compounds by families.


Assuntos
Biocombustíveis/análise , Técnicas de Química Analítica/métodos , Cromatografia Gasosa , Metano/análise , Biomassa , Gases/análise , Gases/química , Limite de Detecção , Metano/química , Gás Natural/análise , Esgotos/química , Resíduos Sólidos/análise , Águas Residuárias/química
4.
J Neuropathol Exp Neurol ; 48(3): 245-54, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2539438

RESUMO

In this paper we demonstrate that the 48 kilodalton (kDa) intermediate filament associated protein (IFAP), previously reported to be present in normal astrocytes, is also present in reactive astrocytes in situ and in reactive-like astrocytes induced by dibutyryl cyclic AMP in vitro. This IFAP is detectable by antibodies in normal rabbit serum (F2N) and is closely associated with glial fibrillary acidic protein-containing intermediate filaments (IF). The expression of 48 kDa IFAP is related to the acquisition of stellate shape by normal and reactive-like astrocytes in vitro. It is proposed that 48 kDa IFAP may be responsible for cross-linking IF into bundles and is thereby associated with cell process formation.


Assuntos
Astrócitos/análise , Bucladesina/farmacologia , Proteínas de Filamentos Intermediários/análise , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/ultraestrutura , Encéfalo/citologia , Células Cultivadas , Imunofluorescência , Proteína Glial Fibrilar Ácida/análise , Imuno-Histoquímica , Filamentos Intermediários/análise , Camundongos , Camundongos Endogâmicos C3H , Microscopia Eletrônica , Peso Molecular , Vimentina/análise
5.
J Clin Endocrinol Metab ; 85(11): 4193-200, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11095453

RESUMO

Measurements of serum insulin-like growth factor I (IGF-I) and related markers are routinely used in the diagnosis and treatment of GH deficiency and excess. The validity of these markers for assessment of exogenous GH exposure in healthy adults is, however, unknown. We therefore conducted a double blind, placebo-controlled GH treatment trial in 99 healthy subjects [49 women and 50 men; mean +/- SE age, 25.6+/-0.6 (women)/25.7+/-0.6 yr (men)]. Blood was collected weekly during a 4-week treatment period (days 1-28), and the subjects were subsequently followed for additional 8 weeks (days 29-84). The treatment arms included: I) 0.1 IU/kg x day GH (n = 30; GH 0.1), II) 0.2 IU/kg x day GH (n = 29; GH 0.2), and III) placebo (n = 40). At baseline no gender-specific differences existed, except that the acid-labile subunit (ALS) levels were higher in females. Serum insulin-like growth factor I (IGF-I) levels in males receiving GH increased significantly through day 42 with no significant difference between the 2 doses. The absolute IGF-I response was significantly lower in females, and there was a clear dose-response relationship. ALS levels in males increased through day 30 (P < 0.001). In females ALS levels were only modestly increased on day 28 compared with those in the placebo group (P < 0.02). IGF-binding protein-3 (IGFBP-3) levels in males increased significantly in the GH 0.1 and the GH 0.2 groups on day 30 (P < 0.03), whereas no solid IGFBP-3 increase was detected in females. IGFBP-2 levels decreased insignificantly during GH exposure in both genders. A gender-specific upper normal range for each analyte was arbitrarily defined as 4 SD above the mean level at baseline. On the basis of IGF-I levels alone, GH exposure in the GH 0.2 group was detected in 86% of the males and in 50% of the females on day 21. On day 42 GH exposure was only weakly detectable in males and was not detectable in females. We conclude that 1) males are significantly more responsive than females to exogenous GH; 2) the increase in IGF-I is more robust compared with those in IGFBP-3 and ALS; 3) IGFBP-2 changes very little during GH treatment; and 4) among IGF-related substances, IGF-I is the most specific marker of supraphysiological GH exposure.


Assuntos
Hormônio do Crescimento Humano/farmacologia , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Adolescente , Adulto , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Placebos , Subunidades Proteicas , Valores de Referência , Caracteres Sexuais
6.
J Chem Neuroanat ; 7(1-2): 113-22, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7802966

RESUMO

The interaction between myosin and F-actin requires the enzyme, myosin light chain kinase (MLCK), as well as Ca(2+)-calmodulin and the calmodulin binding protein, caldesmon, which also binds to F-actin. Using immunofluorescence staining, we have demonstrated that in human fetal astroglia as in mouse astroglia (Abd-El-Basset et al., 1991) the stress fibers contain these contractile elements: F-actin, myosin, tropomyosin and caldesmon. F-actin extends continuously along the stress fibers, whereas myosin, tropomyosin and caldesmon are localized discontinuously in a periodic pattern. In addition, we have demonstrated that fetal human astroglia have the enzyme MLCK and calmodulin. The association of the contractile elements listed above together with calmodulin and MLCK constitutes what may be termed 'contractile units', suggesting that the stress fibers in astroglia may be contractile. Contractile stress fibers would enable astroglia to exert tension on the matrix surrounding them, thus facilitating rapid changes in cell shape.


Assuntos
Astrócitos/ultraestrutura , Neurofibrilas/ultraestrutura , Actinas/metabolismo , Anticorpos Monoclonais , Astrócitos/metabolismo , Calmodulina/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Células Cultivadas , Imunofluorescência , Humanos , Immunoblotting , Imunoeletroforese , Quinase de Cadeia Leve de Miosina/metabolismo , Miosinas/metabolismo , Neurofibrilas/metabolismo , Tropomiosina/metabolismo
7.
Neurosci Lett ; 125(2): 117-20, 1991 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-1881588

RESUMO

In mouse astroglia colony cultures, cells display dramatic changes in their 'social behavior' during differentiation. The non-motile glioblasts progress through highly motile pro-astroblast and astroblast stages before becoming non-motile fibrous astrocytes. These changes in the behavior of astroglia are paralleled by changes in the organization of their microfilaments. Immunofluorescence staining of the astroglia colony cultures with rhodamine phalloidin, which binds to actin filaments (F-actin) formed by any of the 6 actin isoforms and with monoclonal antibody to alpha-smooth muscle (alpha-sm) actin (an actin isoform typical of smooth muscle cells), shows that the majority of the cells are positive for both alpha-sm actin and F-actin. Approximately 15% of the cells, however, were negative for alpha-sm actin but stained positively for F-actin, indicating that the actin of these cells belongs to isoforms other than the alpha-sm isoform.


Assuntos
Actinas/análise , Astrócitos/citologia , Animais , Animais Recém-Nascidos , Imunofluorescência , Camundongos , Camundongos Endogâmicos C3H , Músculo Liso , Especificidade de Órgãos
8.
Anat Rec (Hoboken) ; 294(1): 16-23, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21157913

RESUMO

Cytokines are soluble mediators that are thought to act as communication signals between astroglia and neighboring neural cells. They are both released by, and act on, astroglia. It is hypothesized that it is this effect on astroglia that may be important in widespread phenomena including traumatic brain injury, inflammation, and scar formation. In this article, we examine the effect of mouse recombinant interleukin-1ß (IL-1ß) on the morphology, organization, and expression of glial fibrillary acidic protein (GFAP) and actin isoforms in cultured mouse astroglia. This study shows that the majority of the astroglia treated with IL-1ß acquire long processes. Immunofluorescence staining shows that there are no remarkable changes in the organization of GFAP, F-actin, α-smooth muscle (α-sm) actin, and ß-actin isoforms. In fluorescent microplate assay, the short-term treated astroglia (range, 1-2 days) show an increase in the intensity of GFAP and ß-actin isoform over the level observed in untreated control, whereas no remarkable changes are observed in the intensity of α-sm actin isoform. In the case of long-term treatment (range, 4-8 days), the intensity of GFAP and α-sm actin isoform progressively decreases below the level of untreated control. In addition, the intensity of ß-actin isoform increases above the control level. These results have been confirmed by immunoblotting experiments. The upregulation of ß-actin isoform may be important in limiting the noxious effects of an inflammatory reaction. This gives credence to the hypothesis that it might be possible to modulate astroglial effects on neuronal inflammation and scar formation with appropriate therapies.


Assuntos
Actinas/biossíntese , Astrócitos/citologia , Astrócitos/metabolismo , Interleucina-1beta/fisiologia , Actinas/genética , Animais , Animais Recém-Nascidos , Astrócitos/patologia , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento , Mediadores da Inflamação/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Isoformas de Proteínas/biossíntese
9.
Anat Rec (Hoboken) ; 291(4): 390-9, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18360886

RESUMO

Diabetes affects retinal and nervous glial cells, especially the astrocytes. A key indicator of this response is the alteration in the level of intermediate filament glial fibrillary acidic protein (GFAP) and number of GFAP-immunoreactive astrocytes. To date, no study has investigated the effect of diabetes on the distribution of GFAP-immunoreactive astrocytes in the spinal cord. Therefore, the present study investigated the effect of diabetes on the number of GFAP-immunoreactive astrocytes in the gray matter of the spinal cord of streptozotocin-induced diabetic Wistar rats. Animals were divided into six groups (n = 7); 6 weeks and 12 weeks diabetic duration groups and their respective age-matched normal control and sham control groups. Our results demonstrated a significant (P < 0.001) decrease in the number of GFAP-immunoreactive astrocytes in different areas of the spinal cord sections of the 6 weeks and 12 weeks long diabetic rats when compared with the spinal cord of normal and sham control groups of comparable age. The mean percentage in total number of GFAP-immunoreactive astrocytes in the whole gray matter areas of the spinal cord of the 6 and 12 weeks diabetic groups were approximately 28% and 41% less than control groups. Furthermore, the 12 weeks diabetic group showed a significant (P < 0.001) reduction in the number of GFAP-immunoreactive astrocytes when compared with the 6 weeks diabetic animals. These results suggest that the induction of diabetes is associated with a reduction in GFAP-positive astrocytes in the spinal cord, which may affect the functional support and role of astrocytic cells in the nervous tissue. This in turn may contribute to the pathological changes associated with diabetic state in the central nervous system.


Assuntos
Astrócitos/metabolismo , Diabetes Mellitus Experimental/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Medula Espinal/metabolismo , Animais , Imuno-Histoquímica , Masculino , Ratos , Ratos Sprague-Dawley , Medula Espinal/citologia , Fatores de Tempo , Distribuição Tecidual
10.
Connect Tissue Res ; 40(1): 23-35, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10770648

RESUMO

In order to compare aspects of normal fibroplasia with reports for pathologically fibrotic tissue, light and electron microscopic observations were made on ferret vulval skin, which proliferates markedly with the onset of estrus and regresses equally fast after mating. Estrous tissue, which contained hypertrophied fibroblasts, new collagen, elastic fibers and ground substance, was invaded by numerous eosinophils with extensive release of granules. Eosinophil degranulation was both extra- and intracellular; some cells, completely disintegrated, had released all contents into the extracellular matrix. Extruded granules reacted positively for major basic protein. In regression, diminished fibroblasts incorporated collagen fibrils. Many of the features seen in this normal fibroplasia in ferret vulval skin are similar to those in pathologic situations. Thus, in particular, the presence of degranulating eosinophils in pathologic fibrosis does not necessarily indicate that they are the cause of the disease. Our information and that from other sources implies a role for eosinophils in connective tissue change.


Assuntos
Eosinófilos/citologia , Fibroblastos/citologia , Pele/citologia , Vulva , Animais , Degranulação Celular , Copulação/fisiologia , Eosinófilos/fisiologia , Estro/fisiologia , Feminino , Furões , Fibroblastos/fisiologia , Microscopia Eletrônica , Valores de Referência , Pele/ultraestrutura
11.
Histochem J ; 32(10): 581-90, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11202154

RESUMO

Mammalian cells contain at least 8 actin isoforms. The functional significance and the mechanisms that regulate the expression of each actin isoform are not yet known. Using immunofluorescence staining, it was found that all astroglia in tissue culture express beta-actin isoform and about 86% of astroglia express alpha-smooth muscle actin isoform. When astroglia were treated with dibutyryl cyclic AMP for 4, 7, 14 and 21 days, it was found that the number of the cells expressing alpha-smooth muscle actin isoform progressively decreased, whereas, the number of the cells expressing beta-actin isoform remained constant. The western blot experiment showed that the amount of total alpha-smooth muscle actin isoform (soluble and insoluble) and of the insoluble isoform expressed by astroglia treated with dibutyryl cAMP decreased whereas, the amount of total and insoluble beta-actin isoform expressed by the same cells did not show any significant changes. The cells treated with the cAMP failed to migrate and to close the area created by the scratch wound in monolayer culture. However, the non-treated cells migrated and closed the area created by the scratch after 3 days. This study shows that the astroglia have different mechanisms in regulating the expression of different actin isoforms and that the alpha-sm actin isoform is important in migration of astroglia.


Assuntos
Actinas/biossíntese , Astrócitos/efeitos dos fármacos , Bucladesina/farmacologia , Actinas/análise , Animais , Animais Recém-Nascidos , Astrócitos/química , Astrócitos/metabolismo , Western Blotting , Células Cultivadas , Eletroforese em Gel de Poliacrilamida , Técnica Indireta de Fluorescência para Anticorpo , Proteína Glial Fibrilar Ácida/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Isoformas de Proteínas/biossíntese , Telencéfalo/citologia
12.
J Neurosci Res ; 41(2): 222-37, 1995 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-7650758

RESUMO

We examined the effect of bacterial wall lipopolysaccharide (LPS), a strong inflammatory agent, on the morphology, cell motility, cytoskeletal organization, and phagocytic activity of microglia in tissue cultures initiated from neopallia of newborn C3H/OuJ mice. Normally, the microglia in our cultures are non-migratory and Mac-1 positive, have ameboid cell morphology, no polarity, many short processes that extend into lamellipodia in opposing directions, and undulating cell membrane projections. When 1-5 micrograms/ml LPS is added to such cultures, some cells acquire polarity by forming a large lamellipodium and begin to migrate. Two hours later migration ceases; the membrane undulations stop; and the cells become non-polar, assume a large, round, flat shape, and gradually develop many microspikes all over the cell body. Those cells that do not transform into large, round, flat cells enlarge and extend numerous lamellipodia in opposing directions. We found that the cytoskeleton of microglia is composed of actin, vimentin-containing intermediate filaments (IF) and microtubules (MT). Vimentin-containing IF and MT form dense networks that radiate into the cell periphery, whereas F-actin is diffusely arranged throughout the cytoplasm. The LPS-treated cells show changes in the organization of the main components of the cytoskeleton. F-actin is reorganized by the formation of bundles underneath and parallel to the cell membrane and other bundles projecting into the cores of the microspikes. The vimentin-containing IF dense network reorganizes into two condensed rings, with fine strands of IF extended between the two rings and the MT networks become less dense and extend throughout the cytoplasm. The LPS treatment potentiates the phagocytic activity of the microglia. However, approximately 30% of microglia lose the expression of MHC class II antigens.


Assuntos
Lipopolissacarídeos/farmacologia , Microglia/ultraestrutura , Actinas , Animais , Animais Recém-Nascidos , Anticorpos Monoclonais/imunologia , Antígenos , Células Cultivadas , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos , Microglia/efeitos dos fármacos , Microtúbulos/ultraestrutura
13.
J Neurosci Res ; 30(1): 1-17, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1795393

RESUMO

In this paper we have described the organization of F-actin and actin-binding proteins (ABP): alpha-actinin, myosin, tropomyosin, caldesmon, vinculin, talin, and spectrin, in differentiating astroglia in colony cultures. We observed that the microfilament (MF) network arrangements differ at various stages of astroglia development, but the composition of MF bundles and stress fibers is the same at all developmental stages. F-actin is closely colocalized with myosin, tropomyosin, caldesmon, and alpha-actinin. The striated pattern of myosin, tropomyosin, and caldesmon are superimposable. Tropomyosin and caldesmon extend along F-actin but are interrupted for short periods, whereas myosin is interrupted for longer periods. alpha-actinin colocalizes with tropomyosin and caldesmon but not with myosin. In astroglia at different stages of development spectrin is arranged in the form of fine networks spreading through the cell and does not follow the arrangement of MF bundles. Only F-actin, alpha-actinin, and vinculin can be detected at cell-cell junctions. In the areas of the focal contacts, F-actin, alpha-actinin, vinculin, and talin are present. They overlap each other, although talin and vinculin extend toward the cell membrane beyond F-actin and alpha-actinin. Astroglia undergo well-defined states of nonmotility, motility, and nonmotility again during differentiation. The changes in motility are paralleled by changes in the organization of F-actin and ABP: as GFAP-containing intermediate filaments increase in differentiating astroglia, the F-actin and ABP are down-regulated, leading to non motility.


Assuntos
Actinas/análise , Astrócitos/citologia , Meninges/citologia , Proteínas dos Microfilamentos/análise , Actinas/ultraestrutura , Animais , Animais Recém-Nascidos , Astrócitos/ultraestrutura , Encéfalo/citologia , Células Cultivadas , Técnicas de Cultura/métodos , Imunofluorescência , Junções Intercelulares/ultraestrutura , Camundongos , Camundongos Endogâmicos C3H , Proteínas dos Microfilamentos/ultraestrutura , Modelos Estruturais , Talina/análise , Tropomiosina/análise , Vinculina/análise
14.
Acta Neuropathol ; 88(6): 527-37, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7879599

RESUMO

The phagocytic ability of mouse microglia during their differentiation in culture and after stimulation with bacterial wall lipopolysaccharide (LPS) has been investigated using Fc receptor-mediated phagocytosis of immunoglobulin (IgG)-coated sheep erythrocytes (SRBCs). We observed that in 10-14 day-confluent neopallial cell cultures some immature microglia are not phagocytic but, on further culturing, they do become phagocytic. LPS-stimulated microglia are able to phagocytose larger numbers of IgG-coated SRBCs and at a faster rate than non-stimulated microglia. Within 5-10 min of phagocytosis the actin filaments of the LPS-stimulated microglia become depolymerized, leaving only bundles of actin filaments around the phagocytosed SRBCs (phagosome cups). At 30 min after the start of phagocytosis the actin filaments of the LPS-stimulated microglia begin to polymerize, and within 2 h the original pre-phagocytosis pattern of the actin filament network is re-established. The non-LPS-stimulated microglia exhibit actin filament depolymerization in only a few lamellipodia and polymerization of actin filaments around engulfed particles, but much later during phagocytosis.


Assuntos
Actinas/metabolismo , Eritrócitos/fisiologia , Microglia/citologia , Microglia/fisiologia , Fagocitose , Receptores Fc/fisiologia , Animais , Imunoglobulina G/fisiologia , Lipopolissacarídeos/farmacologia , Camundongos , Microglia/efeitos dos fármacos
15.
J Neurosci Res ; 49(5): 608-16, 1997 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9302082

RESUMO

We have shown previously that in tissue culture stellate astrocytes downregulate F-actin and actin binding proteins (ABPs) (Abd-El-Basset et al.: J Neurosci Res 30:1-17, 1991), whereas the reactive-like astrocytes upregulate their F-actin (Fedoroff et al.: Neuroscience 22:255-266, 1987). In the present study we report that in normal brain, as in tissue culture, neither F-actin nor alpha-actinin (an ABP) could be detected in stellate astrocytes. When a stab wound was made in brain, F-actin and alpha-actinin were upregulated in reactive astrocytes. We also demonstrated that reactive-like astrocytes in tissue culture express alpha-actinin, which has a "dotted" appearance when immunostained, and is colocalized with F-actin in a specific arrangement.


Assuntos
Actinina/metabolismo , Actinas/metabolismo , Astrócitos/metabolismo , Astrócitos/fisiologia , Regulação para Cima/fisiologia , Animais , Anticorpos/imunologia , Encéfalo/citologia , Células Cultivadas , Imuno-Histoquímica , Camundongos
16.
J Neurosci Res ; 21(2-4): 226-37, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3216423

RESUMO

In this paper we present evidence that the 48-kD intermediate filament-associated protein (IFAP) is expressed relatively late in maturation of astrocytes, after they have acquired the glial fibrillary acidic protein (GFAP). In the astrocytes of white matter in the cerebellum the GFAP is detected at P3, whereas the 48-kD IFAP is detected only at P11. In the periventricular region and the hippocampus the 48-kD IFAP was detected at P6, long after the appearance of GFAP. In adult mice the 48-kD IFAP was observed in GFAP-positive astrocytes in the white matter of cerebellum, spinal cord, brainstem, and corpus callosum as well as in GFAP-positive cells in the grey matter of cerebral cortex and spinal cord. The 48-kD IFAP was not, however, detected in radial glia and their derivatives, in Bergmann glia or in Müller glia. Thus, not all the GFAP-positive astroglia express the 48-kD IFAP. Similarly, 48-kD IFAP was not detected in cells which were GFAP-negative.


Assuntos
Astrócitos/metabolismo , Sistema Nervoso Central/metabolismo , Regulação da Expressão Gênica , Proteínas de Filamentos Intermediários/metabolismo , Animais , Astrócitos/citologia , Diferenciação Celular , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C3H , Peso Molecular , Retina/citologia , Retina/metabolismo , Medula Espinal/citologia , Medula Espinal/metabolismo
17.
J Neurosci Res ; 19(1): 1-13, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-2449542

RESUMO

We provide evidence that a protein of 48 kilodaltons (KD), recognized by a normal rabbit serum (F2N), is associated with intermediate filaments (IF) of astrocytes both in cell cultures and in situ. Immunofluorescence staining shows that the F2N serum gives a fibrous staining pattern similar to that seen with anti-serum to glial filament protein (GFP), a protein specific for IF of astrocytes, and that both proteins are present in the perinuclear fibrous aggregates of IF produced by treating the cells with colchicine. At the ultrastructural level the gold particles decorating the 48-KD protein are localized in clusters along the IF, whereas the gold particles decorating the GFP are localized on the IF in a linear pattern. This difference in distribution and the fact that the two proteins have different electrophoretic mobilities on SDS gels indicates that the 48-KD protein although associated with IF is different from GFP. The 48-KD protein appears to be a distinct, developmentally regulated intermediate-filament-associated protein (IFAP), different from other IFAPs reported to date and the first IFAP described in astrocytes. Its appearance in late developmental stages when motile astroblasts are changing into nonmotile stellate cells suggests that the 48-KD protein may be involved in cross-linking the GFP-containing IF to provide more tensile strength to the cytoplasm at the expense of flexibility.


Assuntos
Astrócitos/metabolismo , Proteínas de Filamentos Intermediários/metabolismo , Animais , Astrócitos/ultraestrutura , Encéfalo/citologia , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Células Cultivadas , Imunofluorescência , Camundongos , Camundongos Endogâmicos C3H , Peso Molecular , Coelhos/sangue , Coloração e Rotulagem
18.
Med Princ Pract ; 13(6): 325-33, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15467307

RESUMO

OBJECTIVES: This study investigates how the tumor necrosis factor (TNF-alpha) and interleukin-1beta (IL-1beta) affect the morphology, organization, and expression of actin, beta-actin and tubulin in microglia. MATERIALS AND METHODS: Microglia cultures were prepared from neopallia of newborn mice. Immunofluorescence, immunoblotting, and ELISA studies were used. RESULTS: When microglia are treated with TNF-alpha, IL-1beta or a combination of both for 1-5 days, the majority change from an ameboid to a large, round and flat shape. F-actin and beta-actin isoform, which are diffusely arranged throughout the cytoplasm before stimulation, are reorganized into filamentous bundles underneath and parallel to the cell membrane, which projects into many ruffles. This organization is maintained even after withdrawal of the cytokines. The dense microtubule network of tubulin in nontreated microglia becomes less dense and extends to occupy the cytoplasm of the treated microglia. Immunoblotting shows that the amount of total actin, beta-actin isoform and tubulin increases in treated microglia. In addition, IL-1beta and a combination of both TNF-alpha and IL-1beta stimulate the release of IL-6 by microglia. CONCLUSION: This study suggests that TNF-alpha and IL-1beta have an effect on the expression of cytoskeletal proteins similar to some extent to that of LPS. The up-regulation of actin, beta-actin and tubulin may play a key role in the motility and recruitment of microglia to the area of central nervous system inflammation.


Assuntos
Actinas/biossíntese , Microglia/efeitos dos fármacos , Tubulina (Proteína)/biossíntese , Regulação para Cima , Actinas/ultraestrutura , Animais , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Immunoblotting , Interleucina-1/farmacologia , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microglia/metabolismo , Microglia/ultraestrutura , Isoformas de Proteínas , Receptores de Complemento 3b/metabolismo , Tubulina (Proteína)/ultraestrutura , Fator de Necrose Tumoral alfa/farmacologia
19.
Glia ; 6(2): 149-53, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1398896

RESUMO

Immuno-electron microscopy was used to localize the distribution of vimentin and glial fibrillary acidic protein (GFAP) in mouse astrocytes and their precursor cells in primary cultures. In astroblasts and astrocytes, vimentin and GFAP form intermediate filaments (IF), which are heteropolymers, as previously observed in gliomas. Astrocytes and their precursor cells may have IF composed of GFAP-vimentin heteropolymer or vimentin alone, but IF composed of GFAP only were not seen. It seems that the formation of IF that are GFAP-vimentin heteropolymers is a feature of normal astroglia development and that the ratio of GFAP to vimentin in these IF reflects the degree of differentiation and functional state of the cell.


Assuntos
Astrócitos/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Vimentina/metabolismo , Animais , Animais Recém-Nascidos , Anticorpos Monoclonais , Astrócitos/química , Células Cultivadas , Proteína Glial Fibrilar Ácida/análise , Camundongos , Camundongos Endogâmicos C3H , Microscopia Imunoeletrônica , Vimentina/análise
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