RESUMEN
BACKGROUND: To determine whether a decrease in serum (1,3)-ß-D-glucan (BDG) was associated with reduced mortality and to investigate the performance of BDG downslope in predicting clinical outcome in invasive candidiasis. METHODS: Observational cohort study in ICU patients over a ten-year period (2012-2022) in Italy. Proven invasive candidiasis with at least 2 BDG determinations were considered. RESULTS: In the study population of 103 patients (age 47 [35-62] years, SAPS II score 67 [52-77]) 68 bloodstream and 35 intrabdominal infections were recorded. Serial measurements showed that in 54 patients BDG decreased over time (BDG downslope group) while in 49 did not (N-BDG downslope group). Candida albicans was the pathogen most frequently isolated (61%) followed by C. parapsilosis (17%) and C. glabrata (12%), in absence of any inter-group difference. Invasive candidiasis related mortality was lower in BDG downslope than in N-BDG downslope group (17% vs 53%, p < 0.01). The multivariate Cox regression analysis showed the association of septic shock at infection occurrence and chronic liver disease with invasive candidiasis mortality (HR [95% CI] 3.24 [1.25-8.44] p = 0.02 and 7.27 [2.33-22.66] p < 0.01, respectively) while a BDG downslope was the only predictor of survival (HR [95% CI] 0.19 [0.09-0.43] p < 0.01). The area under the receiver operator characteristic curve for the performance of BDG downslope as predictor of good clinical outcome was 0.74 (p = 0.02) and our model showed that a BDG downslope > 70% predicted survival with both specificity and positive predictive value of 100%. CONCLUSIONS: A decrease in serum BDG was associated with reduced mortality and a steep downslope predicted survival with high specificity in invasive candidiasis.
Asunto(s)
Candidiasis Invasiva , Unidades de Cuidados Intensivos , beta-Glucanos , Humanos , Persona de Mediana Edad , Masculino , Candidiasis Invasiva/sangre , Candidiasis Invasiva/mortalidad , Candidiasis Invasiva/diagnóstico , Femenino , Unidades de Cuidados Intensivos/estadística & datos numéricos , Unidades de Cuidados Intensivos/organización & administración , beta-Glucanos/sangre , beta-Glucanos/análisis , Pronóstico , Adulto , Estudios de Cohortes , Italia/epidemiología , Biomarcadores/sangre , Biomarcadores/análisis , Proteoglicanos/sangre , Proteoglicanos/análisis , Valor Predictivo de las PruebasRESUMEN
Atualmente, a cápsula anterior e o epitélio da lente tem sido cada vez mais estudados, com o intuito de reduzir as possíveis complicações do pós-operatório da remoção da catarata, tal como a opacidade da cápsula posterior, alteração ocasionada principalmente pela diferenciação e migração das células do epitélio lenticular para a cápsula posterior da lente. O objetivo deste estudo foi analisar a composição molecular da cápsula anterior da lente pela técnica histoquímica de PAS (avaliação de proteoglicanos) e picrosirius red (avaliação de colágeno IV), em cães idosos com catarata diabética e não diabética do tipo hipermadura, submetidos ao uso ou não de azul de tripano a 0,1 % durante a facoemulsificação. Vinte e sete cães foram estudados, incluindo 21 fêmeas e 6 machos, de 8 a 12 anos de idade (média = 9,6 anos), de diversas raças e divididos em 2 grupos: GC (catarata hipermadura) e GCD (catarata diabética). Os resultados das análises realizadas mostraram que ambas as amostras, tanto as provenientes das cataratas hipermaduras, quanto das diabéticas, apresentam semelhante composição molecular de proteoglicanos e colágeno IV e isto independente da utilização de azul de tripano a 0,1 %. Conclui-se, portanto, que se os resultados obtidos forem decorrentes de alterações provocadas pelo rápido metabolismo da catarata diabética e pela cronicidade da catarata hipermadura sugere-se que o comprometimento da estrutura capsular seja de intensidade equivalente e, por consequência, que isto também possa prejudicar o metabolismo das células do epitélio anterior da lente, diminuindo assim a incidência da opacidade da cápsula posterior de cães com catarata diabética e hipermadura submetidos à facoemulsificação.(AU)
Nowadays, the anterior lens capsule and its epithelium have been being frequently studied aiming to reduce the incidence of posterior lens capsule opacity, a complication that frequently occurs after surgical removal of cataracts, due to epithelium cells differentiation and migration to the posterior pole. The objective of this study was to evaluate by histochemistry (PAS and picrosirius red) analysis two important molecular components of the anterior lens capsule (proteoglycans and type IV collagen) in older diabetic and non-diabetic dogs, with diabetic and hypermature cataracts, after phacoemulsification surgery utilizing 0.1% trypan blue or not. Twenty seven dogs, including 21 female and 6 male dogs, with ages varying from 8 to 12 years old (mean = 9.6 yo) of different breeds were studied. The animals were divided into 2 groups: GC (hypermature cataracts) and GCD (diabetic cataracts). Results showed that, besides their different pathophysiologies, both types of capsules studied (diabetic and hypermature ones) presented the same molecular composition of proteoglycans and type IV collagen, since no statistical significant differences were observed. In addition, 0.1% trypan blue was not capable to induce any other evident alteration for the samples. In conclusion, our findings suggest that, if the results consist in alteration induced by the aggressive metabolism of the diabetic cataract or the chronicity of the hypermature one, it is of the same intensity and independent of the use of 0.1% trypan blue. It is also possible to suggest that this alteration must be capable to compromise lens epithelium cell metabolism, which should probably favour future lens posterior capsule studies.(AU)
Asunto(s)
Animales , Perros , Cápsula Anterior del Cristalino/patología , Catarata/complicaciones , Catarata/veterinaria , Diabetes Mellitus/veterinaria , Cápsula Posterior del Cristalino/cirugía , Colágeno Tipo IV/análisis , Facoemulsificación/veterinaria , Proteoglicanos/análisis , Azul de TripanoRESUMEN
Atualmente, a cápsula anterior e o epitélio da lente tem sido cada vez mais estudados, com o intuito de reduzir as possíveis complicações do pós-operatório da remoção da catarata, tal como a opacidade da cápsula posterior, alteração ocasionada principalmente pela diferenciação e migração das células do epitélio lenticular para a cápsula posterior da lente. O objetivo deste estudo foi analisar a composição molecular da cápsula anterior da lente pela técnica histoquímica de PAS (avaliação de proteoglicanos) e picrosirius red (avaliação de colágeno IV), em cães idosos com catarata diabética e não diabética do tipo hipermadura, submetidos ao uso ou não de azul de tripano a 0,1 % durante a facoemulsificação. Vinte e sete cães foram estudados, incluindo 21 fêmeas e 6 machos, de 8 a 12 anos de idade (média = 9,6 anos), de diversas raças e divididos em 2 grupos: GC (catarata hipermadura) e GCD (catarata diabética). Os resultados das análises realizadas mostraram que ambas as amostras, tanto as provenientes das cataratas hipermaduras, quanto das diabéticas, apresentam semelhante composição molecular de proteoglicanos e colágeno IV e isto independente da utilização de azul de tripano a 0,1 %. Conclui-se, portanto, que se os resultados obtidos forem decorrentes de alterações provocadas pelo rápido metabolismo da catarata diabética e pela cronicidade da catarata hipermadura sugere-se que o comprometimento da estrutura capsular seja de intensidade equivalente e, por consequência, que isto também possa prejudicar o metabolismo das células do epitélio anterior da lente, diminuindo assim a incidência da opacidade da cápsula posterior de cães com catarata diabética e hipermadura submetidos à facoemulsificação.
Nowadays, the anterior lens capsule and its epithelium have been being frequently studied aiming to reduce the incidence of posterior lens capsule opacity, a complication that frequently occurs after surgical removal of cataracts, due to epithelium cells differentiation and migration to the posterior pole. The objective of this study was to evaluate by histochemistry (PAS and picrosirius red) analysis two important molecular components of the anterior lens capsule (proteoglycans and type IV collagen) in older diabetic and non-diabetic dogs, with diabetic and hypermature cataracts, after phacoemulsification surgery utilizing 0.1% trypan blue or not. Twenty seven dogs, including 21 female and 6 male dogs, with ages varying from 8 to 12 years old (mean = 9.6 yo) of different breeds were studied. The animals were divided into 2 groups: GC (hypermature cataracts) and GCD (diabetic cataracts). Results showed that, besides their different pathophysiologies, both types of capsules studied (diabetic and hypermature ones) presented the same molecular composition of proteoglycans and type IV collagen, since no statistical significant differences were observed. In addition, 0.1% trypan blue was not capable to induce any other evident alteration for the samples. In conclusion, our findings suggest that, if the results consist in alteration induced by the aggressive metabolism of the diabetic cataract or the chronicity of the hypermature one, it is of the same intensity and independent of the use of 0.1% trypan blue. It is also possible to suggest that this alteration must be capable to compromise lens epithelium cell metabolism, which should probably favour future lens posterior capsule studies.
Asunto(s)
Animales , Perros , Catarata/complicaciones , Catarata/veterinaria , Cápsula Anterior del Cristalino/patología , Cápsula Posterior del Cristalino/cirugía , Diabetes Mellitus/veterinaria , Azul de Tripano , Colágeno Tipo IV/análisis , Facoemulsificación/veterinaria , Proteoglicanos/análisisRESUMEN
Objective The identification of stem cells (SC) remains challenging. In the human oral mucosal epithelium, these cells are believed to be in the basal layer (stem cell niche), but their exact location is unclear. The aim of this study was to examine the dysplastic oral epithelium for these SC-like proteins in order to assess their diagnostic value as biomarkers complementing the histological grading of dysplasia. Material and Methods Thirty oral epithelial dysplasia (OED), 25 oral lichen planus (OLP), 10 oral hyperkeratosis and 5 normal oral epithelium (OE) were immunohistochemically examined for four SC markers [integrin β1, neuron-glial-2 (NG2), notch 1 (N1) and keratin 15 (K15)]. Results Three of four SC markers were heterogeneously detected in all samples. K15 overexpression in the lower two-thirds of severe OED suggests an expanded SC niche. Integrin β1 distribution pattern was not measurably different between OEDs and control. NG2 was almost negative to absent in all samples examined. N1 expression was weak and highly variable in normal and dysplastic epithelium, making it an unreliable epithelial stem cell marker. Conclusions Present findings suggest that these markers were unable to identify individual epithelial stem cells. Instead, subpopulations of cells, most probably stem cells and transit amplifying cells with stem cell-like properties were identified in the dysplastic oral epithelium. The characteristic expressions of K15 might be of diagnostic value for oral dysplasia and should be investigated further. .
Asunto(s)
Humanos , Células Epiteliales/metabolismo , Proteínas/metabolismo , Células Madre/metabolismo , /análisis , Antígenos/análisis , Biomarcadores/análisis , Células Epiteliales/patología , Hiperplasia/metabolismo , Inmunohistoquímica , /análisis , Liquen Plano Oral/metabolismo , Liquen Plano Oral/patología , Mucosa Bucal/metabolismo , Mucosa Bucal/patología , Adhesión en Parafina , Proteoglicanos/análisis , Receptor Notch1/análisis , Valores de Referencia , Índice de Severidad de la Enfermedad , Células Madre/patologíaRESUMEN
Introduction: Endocan levels were found to be associated with severity and mortality of the respiratory system diseases. Objective: We aimed to figure out whether endocan was an important marker for the diagnosis, severity and follow-up of bronchopulmonary dysplasia (BPD). Materials and methods: Infants with moderate/severe BPD, and who required hydrocortisone treatment were included in the study group. Infants without BPD were allocated in the control group. Endocan levels were compared between the control group and the study group, and before and after the treatment in the study group. Results: A total of 148 infants, 74 infants in the control group and 74 infants in the BPD group, were included. The endocan level was higher in the BPD group than in the control group (P = .001). Endocan levels before treatment in the BPD group was found to be higher than endocan level after treatment (P = .021). Conclusion: Our study found that endocan levels increased in moderate/severe BPD. Serum endocan levels may be a safe and novel indicator for the follow-up of response to treatment and the prognosis of the severity of the disease
Introducción: Los niveles de endocan se han asociado con la mortalidad y la gravedad de enfermedades del aparato respiratorio. Objetivo: El objetivo fue averiguar si el endocan es un marcador útil para el diagnóstico, la gravedad y el seguimiento de la displasia broncopulmonar (DBP). Materiales y métodos: Se incluyeron en el estudio lactantes con DBP moderada/grave que requirieron tratamiento con hidrocortisona (grupo DBP). El grupo control lo constituyeron lactantes sin DBP. Los niveles de endocan se compararon entre el grupo control y el grupo de estudio y, en este último, tanto antes como después del tratamiento. Resultados: Se incluyeron un total de 148 lactantes; 74 en el grupo control y 74 en el grupo DBP. Los niveles de endocan fueron más elevados en el grupo DBP que en el grupo control (p = 0,001). Los niveles de endocan también resultaron superiores en el grupo DBP antes del tratamiento que después del mismo (p = 0,021). Conclusión: Nuestro estudio halló que los niveles de endocan se encuentran incrementados en la DBP moderada/grave. Los niveles séricos de endocan podrían utilizarse como un nuevo indicador seguro para el seguimiento de la respuesta al tratamiento y el pronóstico de gravedad de la enfermedad
Asunto(s)
Humanos , Lactante , Pulmón/patología , Displasia Broncopulmonar/sangre , Recién Nacido de muy Bajo Peso/sangre , Pronóstico , Proteoglicanos/análisis , Pulmón/fisiopatología , Biomarcadores/sangre , Displasia Broncopulmonar/diagnóstico , Displasia Broncopulmonar/patología , Índice de Severidad de la Enfermedad , Hidrocortisona/uso terapéuticoRESUMEN
INTRODUCTION: Although previous studies have been performed on cartilage explant cultures, the generalized dynamics of cartilage metabolism after extraction from the host are still poorly understood due to differences in the experimental setups across studies, which in turn prevent building a complete picture. METHODS: In this study, we investigated the response of cartilage to the trauma sustained during extraction and determined the time needed for the cartilage to stabilize. Explants were extracted aseptically from bovine metacarpal-phalangeal joints and cultured for up to 17 days. RESULTS: The cell viability, cell number, proteoglycan content, and collagen content of the harvested explants were analyzed at 0, 2, 10, and 17 days after explantation. A high percentage of the cartilage explants were found to be viable. The cell density initially increased significantly but stabilized after two days. The proteoglycan content decreased gradually over time, but it did not decrease to a significant level due to leakage through the distorted peripheral collagen network and into the bathing medium. The collagen content remained stable for most of the culture period until it dropped abruptly on day 17. CONCLUSION: Overall, the tested cartilage explants were sustainable over long-term culture. They were most stable from day 2 to day 10. The degradation of the collagen on day 17 did not reach diseased levels, but it indicated the potential of the cultures to develop into degenerated cartilage. These findings have implications for the application of cartilage explants in pathophysiological fields.
Asunto(s)
Animales , Bovinos , Cartílago Articular/metabolismo , Colágeno/análisis , Proteoglicanos/análisis , Recuento de Células , Supervivencia Celular , Técnicas de Cultivo , Cartílago Articular/química , Cartílago Articular/citología , Cartílago Articular/efectos de los fármacos , Colágeno/metabolismo , Proteoglicanos/metabolismo , Factores de TiempoRESUMEN
La apolipoproteína CIII (apoCIII) inhibe la hidrólisis de triglicéridos de la VLDL y quilomicrones por la lipasa lipoproteica. Se ha pensado que la hipertrigliceridemia resultante explica la asociación entre el aumento de la apoCIII con exageración del riesgo cardiovascular. Sin embargo, estudios clínicos indican que un aumento de la apoCIII asociada a las LDL es un factor de riesgo independiente de la hipertrigliceridemia. Experimentos recientes indican que la apoCIII incrementa la adhesión de monocitos al endotelio, un requisito para la acumulación de macrófagos en la aterogénesis. Además, LDL ricas en apoCIII tienen una alta afinidad por los proteoglicanos de la íntima, lo cual podría aumentar su deposición subendotelial. Estas dos propiedades y efectos de la LDL rica en apoCIII pueden ser la base de los hallazgos indicativos de que la apoCIII es un agente causal de la aterogénesis y un factor de riesgo cardiovascular independiente (AU)
Summary The apolipoprotein CIII (apoCIII) is an inhibitor of the hydrolysis of triglycerides inchylomicrons and VLDL by lipoprotein lipase. It has been accepted that the hypertriglyceridemia induced by high apoCIII can explain its association with increased cardiovascular risk.However, several studies indicate that increased apoCIII is a risk factor independent of hypertriglyceridemia. Recent experimental evidence in vitro and in vivo indicates that apoCIII byitself, or associated with lipoproteins, increase expression of cell adhesion molecules in theendothelium and monocytes. Thus causing associations between these cells. In addition, it hasbeen shown that LDL rich in apoCIII have a high affinity for proteoglycans of the arterial intima.A property that could increase the rate of LDL entrapment in the subendothelial intima. Thesetwo properties of LDL rich in apoCIII indicate that apoCIII is a significant risk factor because itcan have a causal role in atherogenesis (AU)
Asunto(s)
Humanos , Apolipoproteína C-III/análisis , Aterosclerosis/fisiopatología , Dislipidemias/fisiopatología , Hiperlipidemias/fisiopatología , Proteoglicanos/análisis , Inflamación/fisiopatología , Factores de RiesgoRESUMEN
Introducción La LDL electronegativa (LDL[−]) es una fracción minoritaria de la LDL total que se encuentra en circulación y presenta diferentes propiedades inflamatorias, siendo una de las más relevantes la inducción de citoquinas en células endoteliales y mononucleares. Sin embargo, no se conoce el mecanismo por el cual la LDL(−) ejerce su acción (..) (AU)
Introduction Elecronegative LDL (LDL(−)) is a small fraction of the total circulating LDL and has different inflammatory properties, one of the most important being the induction of cytokines in endotelial cells and monocytes. However, the mechanism by which LDL (−) exercises its action at cellular level is not known. The objective of this study was to evaluate the receptors involved in LDL (−) binding in monocytes, and how the liberation of cytokines (..) (AU)
Asunto(s)
Humanos , Citocinas/agonistas , LDL-Colesterol/farmacocinética , Receptores Toll-Like/análisis , Proteoglicanos/análisis , Monocitos/fisiología , Receptores de Lipopolisacáridos/fisiologíaRESUMEN
The expression of components present in the cartilaginous extracellular matrix is related to development, gender, and genotype, as well as to the biomechanical properties of each type of cartilage. In the present study, we analyzed small proteoglycans and glycosaminoglycans present in different cartilages of the chicken wing after extraction with guanidine hydrochloride or papain. Quantitative analysis of glycosaminoglycans showed a larger amount in humeral cartilage (around 200 mg/g tissue) than in articular cartilage of the radius and ulna, with 138 and 80 mg/g tissue, respectively. Non-collagenous proteins isolated were predominantly from cartilage in the proximal regions of the humerus and radius. D4 fractions obtained by ultracentrifugation were separated by DEAE-Sephacel and Octyl-Sepharose chromatography and analyzed by SDS-PAGE. Two bands of 57 and 70-90 kDa were observed for all samples treated with ß-mercaptoethanol. Immunoblotting of these proteins was positive for the small proteoglycans fibromodulin and decorin, respectively. Apparently, the 57-kDa protein is present in macromolecular complexes of 160 and 200 kDa. Chondroitin sulfate was detected in all regions. HPLC analysis of the products formed by chondroitinase AC and ABC digestion mainly revealed ß-D-glucuronic acid and N-acetyl ß-D-galactosamine residues. The 4-sulfation/6-sulfation ratio was close to 3, except for the proximal cartilage of the radius (2.5). These results suggest functional differences between the scapula-humerus, humerus-ulna, and humerus-radius joints of the chicken wing. This study contributes to the understanding of the physiology of cartilage and joints of birds under different types of mechanical stress.
Asunto(s)
Animales , Cartílago Articular/química , Matriz Extracelular/química , Glicosaminoglicanos/análisis , Proteoglicanos/análisis , Pollos , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Húmero/química , Radio (Anatomía)/química , Cúbito/química , Alas de Animales/químicaRESUMEN
En la reacción de hipersensibilidad inmediata, el alérgenose une a su anticuerpo específico tipo IgE, unido a su vez a los receptores de alta afinidad para la IgE (FccRI) de las células efectoras, fundamentalmente mastocitos y basófilos. El entrecruzamiento de estas moléculas de F ccRI tras la unión de antígenos polivalentes a la IgE, activa a estas células produciéndóse tres respuestas biológicas: exocitosis del contenido preformado de sus gránulos, sintetización de mediadores lipídicos y secreción de citoquinas. Los mediadores de la inflamación son en último termino, las sustancias responsables de la sintomatología clínica. Pueden dividirse en general en mediadores preformados (aminas biógenas y macromoléculas de los gránulos) y mediadores de nueva síntesis (mediadores lípidicos y citoquinas)
In the reaction of immediate hypersensibility to alergene is joined to itsspecific type IgE antibody, also united to the high afflnity receptors for IgE (FccI) of the effecters cells fundamentally mastocites and basophiles. The interbreeding of these molecules Fcc to RI, after the union ofpolyvalent antigenes to IgE, active these cells, producing three biologic responses: excitosis of the preformed content of its granules, synthesization of lipidic mediators and citoquine secretion. The inflammation mediators are in last term, substances responsible of the clinic symptomatology. They can be divided generally in preformed mediators (biogene amines and macromolecules ofthe granules) and ofnew synthese mediators (lipidic and citoquine mediators)
Asunto(s)
Cavidad Nasal/fisiopatología , Mucosa Nasal/fisiopatología , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/análisis , Hipersensibilidad/complicaciones , Mastocitos/patología , Aminas/uso terapéutico , Proteoglicanos , Citocinas , Óxido Nítrico , Senos Paranasales/fisiopatología , Obstrucción Nasal/patología , Receptores de Citocinas/inmunología , Mediadores de Inflamación , Proteoglicanos/análisis , Obstrucción Nasal/fisiopatología , Mediadores de Inflamación/antagonistas & inhibidores , Conjuntivitis/complicaciones , Eosinófilos/inmunología , Óxido Nítrico/análisisRESUMEN
Introducción. El crecimiento óseo precisa de una intensa actividad anabólica que se centra, sobre todo, en la síntesis proteica. Cualquier alteración que afecte a la multiplicación celular y su diferenciación, la síntesis del colágeno o la formación de proteoglicanos puede producir un cambio patológico. Revisión de la bibliografía. Los autores han llevado a cabo una profunda revisión bibliográfica referente al cartílago de crecimiento. Conclusiones. Las hormonas actúan según diferentes patrones sobre el desarrollo esquelético, cambiando el grosor de las fisis y el índice y magnitud de su crecimiento. Hay factores locales en y alrededor de las epífisis unidos a los factores sistémicos (hormona de crecimiento, hormona tiroidea, estrógenos y andrógenos, glucocorticoides y vitamina D) que influyen sobre la función fisaria, sin olvidar que la modificación de los factores mecánicos puede producir importantes alteraciones en la magnitud del crecimiento y en su orientación
Introduction. Bone growth requires intense anabolic activity centering mainly on protein synthesis. Any disturbance affecting cell multiplication and differentiation, collagen synthesis, or proteoglycan formation can produce a pathologic disorder. Literature review. The literature on the growth cartilage has been reviewed in depth. Conclusions. Hormones act in different ways on skeletal development, changing the thickness of the growth cartilage and the index and magnitude of growth. Local factors act in and around the growth cartilage, together with systemic factors (growth hormone, thyroid hormone, estrogens and androgens, glucocorticoids and vitamin D) that influence growth cartilage function. In addition, modifications in mechanical factors can produce important disturbances in the magnitude and direction of growth
Asunto(s)
Humanos , Cartílago/crecimiento & desarrollo , Crecimiento/fisiología , Placa de Crecimiento/fisiología , Desarrollo Óseo/fisiología , Proteoglicanos/análisis , Hormona del Crecimiento/análisis , Fenómenos BiomecánicosRESUMEN
La zona de membrana basal es una estructura compleja. Está constituída por la membrana plasmática de la célula basal, lámina lúcida, lámina densa y región de anclaje; cada una de ellas posee diversos componentes moleculares. Sus principales funciones biológicas son actuar como soporte y barrera mecánica, permite la fijación dermoepidérmica, regular la filtración y permeabilidad y guiar la regeneración tisular
Asunto(s)
Humanos , Membrana Basal/ultraestructura , Membrana Basal/embriología , Membrana Basal/fisiología , Colágeno/análisis , Fibronectinas/análisis , Laminina/análisis , Penfigoide Ampolloso/inmunología , Proteoglicanos/análisisRESUMEN
Insulin-like growth factor-I (IGF-I), also known as somatomedin-C, is an important mediator of growth regulation. Serum concentrations of IGF-I and proteoglycan synthesis rates in the tibial epiphysis, an estimate of the biological response to IGF-I in a target tissue, were compared in weanling Wistar rats fed ad libitum (group 1) and with 50% restriction (group 2) with the regional diet of Säo Paulo State (RDSPS--a mean diet consumed by low-income families with rice, beans, sugar, meat, milk, fruits and other vegetables) and in pair-fed animals fed with casein diets (groups 3 and 4). Data are reported as mean +/- SD for 8 rats in each group. Proteoglycan synthesis rates (cpm/mg) were significantly higher in rats fed with the RDSPS-based diet (groups 1 and 2: 210.8 +/- 58.8, 136.6 +/- 17.6) than in pair-fed animals fed with an 11% casein diet (groups 3 and 4: 62.9 +/- 11.6, 37.7 +/- 13.7) and in control animals fed ad libitum with a 20% casein diet (group 5: 58.1 +/- 22.7). Furthermore, these rates were higher in animals fed ad libitum than in those fed with the same diets but with 50% restriction. However, similar differences between groups 1 to 4 were not observed in serum concentrations (ng/100 microliters) of IGF-I (group 1: 44.1 +/- 7.1; group 2: 40.8 +/- 3.8; group 3: 46.0 +/- 3.6; group 4: 41.6 +/- 3.4, and group 5: 63.2 +/- 7.8). These results suggest that serum IGF-I levels are not reliable indicators of IGF-I status in this experimental model
Asunto(s)
Animales , Envejecimiento/metabolismo , Caseínas/administración & dosificación , Dieta , Proteínas en la Dieta/administración & dosificación , Factor I del Crecimiento Similar a la Insulina/análisis , Proteoglicanos/biosíntesis , Brasil , Epífisis/metabolismo , Proteoglicanos/análisis , Ratas , Ratas Wistar , Tibia , DesteteRESUMEN
Considerando o papel fisiológico e biológico da matriz extracelular, propomo-nos a estudar a estrutura da rede de glicosaminoglicanas (GAGs) e proteoglicanas (PGs) no tecido conjuntivo de polpas de dentes molares humanos hígidos de pacientes ao redor de 20 anos. As polpas foram fixadas para microscopia eletrônica de transmissäo em soluçöes de glutaraldeído com vermelho de rutênio e com tetróxido de ósmio reduzido. A rede de GAGs e PGs foi constituída por grânulos de filamentos dispostos numa extensa malha uniforme, contínua e compacta, com nítido inter-relacionamento com a estrutura e posicionamento das fibrilas colágenas e com a superfície de células do tecido conjuntivo
Asunto(s)
Humanos , Adulto , Pulpa Dental/ultraestructura , Proteoglicanos/análisis , Rutenio/uso terapéutico , Glutaral/uso terapéutico , Tejido Conectivo/ultraestructura , Matriz Extracelular/ultraestructura , Glucosamina/análisis , Microscopía Electrónica/métodos , Tetróxido de Osmio/uso terapéuticoRESUMEN
El cartílago articular está formado por células (condrocitos) y una compleja matriz extracelular, sintetizada por ellas, que sufre una remodelación continua regulada por factores anabólicos (factores de crecimiento) y catabólicos (interleucinas). Este artículo es una actualización sobre la composición, metabolismo, bioquímica y biología del cartílago articular. Se realiza una descripción detallada de la composición de la matriz extracelular, con especial énfasis en los colágenos, proteoglicanos, glicoproteínas y proteasas. Además, se exponen detalladamente las principales familias de factores de crecimiento e interleucinas que regulan la biología del cartílago articular en condiciones normales. (AU)