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1.
Am J Transplant ; 18(2): 321-327, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29194964

RESUMEN

The science of regenerative medicine is arguably older than transplantation-the first major textbook was published in 1901-and a major regenerative medicine meeting took place in 1988, three years before the first Banff transplant pathology meeting. However, the subject of regenerative medicine/tissue engineering pathology has never received focused attention. Defining and classifying tissue engineering pathology is long overdue. In the next decades, the field of transplantation will enlarge at least tenfold, through a hybrid of tissue engineering combined with existing approaches to lessening the organ shortage. Gradually, transplantation pathologists will become tissue-(re-) engineering pathologists with enhanced skill sets to address concerns involving the use of bioengineered organs. We outline ways of categorizing abnormalities in tissue-engineered organs through traditional light microscopy or other modalities including biomarkers. We propose creating a new Banff classification of tissue engineering pathology to standardize and assess de novo bioengineered solid organs transplantable success in vivo. We recommend constructing a framework for a classification of tissue engineering pathology now with interdisciplinary consensus discussions to further develop and finalize the classification at future Banff Transplant Pathology meetings, in collaboration with the human cell atlas project. A possible nosology of pathologic abnormalities in tissue-engineered organs is suggested.


Asunto(s)
Rechazo de Injerto/patología , Trasplante de Riñón , Riñón/patología , Patología Clínica/normas , Medicina Regenerativa , Ingeniería de Tejidos , Rechazo de Injerto/clasificación , Humanos
2.
Sci Rep ; 7(1): 16875, 2017 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-29203902

RESUMEN

Injection of amniotic fluid stem cells (AFSC) delays the course of progression of renal fibrosis in animals with Alport Syndrome, enhancing kidney function and improving survival. The mechanisms responsible for these protective outcomes are still largely unknown. Here, we showed that vascular endothelial growth factor (VEGF) signaling within the glomeruli of Alport mice is strongly elevated early on in the disease, causing glomerular endothelial cell damage. Intraventricular injected AFSC that homed within the glomeruli showed strong modulation of the VEGF activity, particularly in glomerular endothelial cells. To investigate this phenomenon we hypothesized that extracellular vesicles (EVs) produced by the AFSC could be responsible for the observed renoprotection. AFSC derived EVs presented exosomal and stem cell markers on their surface membrane, including VEGFR1 and VEGFR2. EVs were able to modulate VEGF in glomerular endothelial cells by effectively trapping the excess VEGF through VEGFR1-binding preventing cellular damage. In contrast, VEGFR1/sVEGFR1 knockout EVs failed to show similar protection, thus indicating that VEGF trapping is a potentially viable mechanism for AFSC-EV mediated renoprotection. Taken together, our findings establish that EVs secreted by AFSC could target a specific signaling pathway within the glomerulus, thus representing a new potential glomerulus-specific targeted intervention.


Asunto(s)
Células Endoteliales/metabolismo , Vesículas Extracelulares , Células Madre/metabolismo , Líquido Amniótico/citología , Animales , Células Cultivadas , Técnicas de Cocultivo , Creatinina/sangre , Modelos Animales de Enfermedad , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Vesículas Extracelulares/metabolismo , Glomérulos Renales/citología , Ratones , Nefritis Hereditaria/metabolismo , Nefritis Hereditaria/patología , Proteinuria/patología , Transducción de Señal , Células Madre/citología , Factor A de Crecimiento Endotelial Vascular/farmacología , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo
3.
Artículo en Inglés | MEDLINE | ID: mdl-28167552

RESUMEN

Despite its toxicity and low efficacy in the chronic phase, benznidazole is the drug of choice in Chagas disease. Scarce information about pharmacokinetics and pharmacodynamics of benznidazole has been published. We performed a phase I, open-label, nonrandomized pharmacokinetic study of benznidazole (Abarax) conducted with 8 healthy adult volunteers at the Infectious Diseases Department of the Vall d'Hebron University Hospital (Barcelona, Spain). The separation and detection of benznidazole were performed on a Waters Acquity ultraperformance liquid chromatography system (UPLC) coupled with a Waters Xevo TQ MS triple quadrupole mass spectrometer. The pharmacokinetic parameters were calculated based on a noncompartmental body model using Phoenix WinNonlin version 6.3 software. Furthermore, computational simulations were calculated for the multiple-dose administration at two dose regimens: 100 mg of benznidazole administered every 8 h and 150 mg of benznidazole administered every 12 h. After benznidazole administration, the median area under the concentration-time curve from time zero to time t (AUC0-t ) and extrapolated to infinity (AUC0-∞) were about 46.4 µg · h/ml and 48.4 µg · h/ml, respectively. Plasma benznidazole concentrations peaked at 3.5 h, with maximal concentrations of 2.2 µg/ml, and benznidazole exhibited a terminal half-life of 12.1 h. The median maximum concentration (Cmax) of benznidazole was lower in men than in women (1.6 versus 2.9 µg/ml), and median volume of distribution (V) as a function of bioavailability (F) was higher in men than in women (125.9 versus 88.6 liters). In conclusion, dose regimens (150 mg/12 h or 100 mg/8 h) reached a steady-state range concentration above of the minimum experimental therapeutic dose. Sex differences in the benznidazole pharmacokinetics were observed; mainly, men had lower Cmax and higher V/F than women.


Asunto(s)
Modelos Estadísticos , Nitroimidazoles/farmacocinética , Tripanocidas/farmacocinética , Adolescente , Adulto , Área Bajo la Curva , Disponibilidad Biológica , Índice de Masa Corporal , Enfermedad de Chagas/tratamiento farmacológico , Enfermedad de Chagas/parasitología , Esquema de Medicación , Cálculo de Dosificación de Drogas , Femenino , Semivida , Voluntarios Sanos , Humanos , Masculino , Nitroimidazoles/sangre , Tripanocidas/sangre
4.
Arq. bras. med. vet. zootec ; 65(5): 1554-1560, out. 2013. graf
Artículo en Inglés | LILACS | ID: lil-689776

RESUMEN

The presented study aimed to verify the effect of different pH values, enzyme solutions and heat treatments on the antimicrobial activity of the bacteriocinogenic strain Lactococcus lactis subsp. lactis Lc08 and to test their antimicrobial activity against Listeria monocytogenes in reconstituted skim milk at refrigeration temperatures. This strain was previously described as a nisin Z producer and capable of inhibiting L. monocytogenes growth in in vitro tests. The antimicrobial activity of the bacteriocin cell-free supernatant of Lc08 was sensitive to enzyme treatments (except papain). The pH values and heating (65ºC for 30min, 75ºC for 15s) had no apparent effect on the antimicrobial activity of the bacteriocin produced by Lc08. Only treatment at autoclave conditions result in loss of their antimicrobial activity. Lc08 presented antimicrobial activity against L. monocytogenes in the milk system after 12h at 25ºC. No effect was found at 7ºC. The results show the application viability of the Lc08 in food systems as a biopreservative against L. monocytogenes.


O presente estudo teve como objetivo verificar o efeito de diferentes valores de pH, soluções enzimáticas e tratamentos térmicos na atividade antimicrobiana da cepa bacteriocinogênica Lactococcus lactis subsp. lactis Lc08 e testar sua atividade antagonista contra Listeria monocytogenes em leite desnatado reconstituído em diferentes temperaturas de estocagem. Essa cepa já foi descrita como produtora de nisina Z e capaz de inibir o desenvolvimento de L. monocytogenes em testes in vitro. A atividade antimicrobiana do sobrenadante de Lc08 contendo a bacteriocina produzida e livre de células foi sensível ao tratamento pelas enzimas testadas (exceto papaína). A aplicação de diferentes valores de pH e o tratamento térmico (65ºC por 30 min, 75ºC por 15s) não influenciaram na atividade antimicrobiana da bacteriocina produzida por Lc08. Apenas o tratamento em autoclave resultou em perda da sua capacidade em inibir o desenvolvimento de L. monocytogenes. A cepa Lc08 apresentou atividade antagonista contra L. monocytogenes em leite após período de estocagem de 12h a 25ºC. Não foi observado efeito a 7ºC. Os resultados mostram a viabilidade de aplicação da cultura Lc08 ou de sua bacteriocina em produtos lácteos como bioconservador contra L. monocytogenes.


Asunto(s)
Animales , Lactococcus lactis/crecimiento & desarrollo , Leche/estadística & datos numéricos , Leche , Listeria monocytogenes/crecimiento & desarrollo , Nisina , Productos con Acción Antimicrobiana
5.
Arq. Inst. Biol ; 80(2): 249-252, 20130000.
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1462225

RESUMEN

Austrodiplostomum compactum and Ithyoclinostomum dimorphum are two trematodes commonly found in trahira, but these parasites were never reported in trahiras from Rio Doce. Thus, the aim of this study is to describe the occurrence of A. compactum and I. dimorphum metacercariae in trahira from the middle course of the Rio Doce and to record the presence of eggs in I. dimorphum metacercariae. The parasites were identified and analyzed using methods described previously. There were found 10 A. compactum metacercariae in the aqueous humor of eyes in four of the trahiras and 12 I. dimorphum metacercariae encysted in the peritoneal cavity in five of the trahiras. Maceration of the I. dimorphum metacercariae revealed the presence of eggs. These results demonstrate the broad distribution of these parasites and the first report of these parasites in trahira from Rio Doce.


Austrodiplostomum compactum e Ithyoclinostomum dimorphum são dois trematódeos comumente encontrados em traíras, contudo, esses parasitas nunca foram relatados em traíras do Rio Doce. O objetivo do estudo é descrever a ocorrência de metacercárias de A. compactum e I. dimorphum, e presença de ovos em metacercárias de I. dimorphum em traíras provenientes do médio curso do Rio Doce. Os parasitas foram analisados e identificados utilizando métodos descritos anteriormente. Foram encontradas 10 metacercárias de A. compactum no humor aquoso dos olhos em quatro traíras e 12 metacercárias de I. dimorphum encistadas na cavidade peritoneal de cinco traíras. A maceração de metacercárias de I. dimorphum revelou a presença de ovos nestes parasitos. Esses resultados demonstram a ampla distribuição desses trematódeos e este é o primeiro relato destes parasitos em traíra do Rio Doce.


Asunto(s)
Animales , Erythrinus , Trematodos , Parásitos
6.
J Appl Microbiol ; 113(2): 318-28, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22587647

RESUMEN

AIMS: To provide molecular and phenotypical characterization of Enterococcus isolates obtained from raw milk and cheese, regarding their bacteriocinogenic and virulence activity. METHODS AND RESULTS: Forty-three bacteriocinogenic enterococci isolates were identified by 16s rDNA, fingerprinted by RAPD-PCR analysis and tested by PCR for the presence of genes for lantibiotics (lanM, lanB and lanC) and enterocins (entA, entB, entP, entL50AB and entAS48) and by phenotypical methods for bacteriocin production and inhibitory spectrum. Also, the virulence of the isolates was evaluated by PCR for genes gelE, hyl, asa1, esp, cylA, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc and by phenotypical tests for gelatinase, lipase, DNAse and α- and ß-haemolysis. Most isolates (93·0%) harboured at least one lantibiotic or enterocin gene and were positive for several tested virulence genes, mainly asa1 (100%), gelE (93·0%) and efaA (83.7%). 53.5% of the isolates presented ß-haemolysis [corrected]. CONCLUSIONS: Enterococcus spp. isolates presented an interesting potential application for food preservation because of bacteriocin production; however, virulence-related genes were identified in all RAPD profiles. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrated the contradictory characteristics of the tested Enterococcus isolates: they presented a good potential for application in food biopreservation but contained several virulence factors.


Asunto(s)
Queso/microbiología , Enterococcus/clasificación , Enterococcus/patogenicidad , Leche/microbiología , Animales , Bacteriocinas/genética , Enterococcus/genética , Enterococcus/aislamiento & purificación , Genes Bacterianos , ARN Ribosómico 16S/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Virulencia
7.
Horm Res Paediatr ; 76(6): 419-27, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22156543

RESUMEN

AIM: This study was designed to estimate the percentage of growth hormone (GH)-treated children born small for gestational age (SGA), with serum IGF-1 >2 SDS before and after GH dose adaptation. METHODS: SGA boys aged 4-9 and girls aged 4-7 with a height <-2 SDS and an annual growth rate below the mean received a subcutaneous GH dose of 57 µg/kg/day for 2 years. The GH dose was to be decreased by 30% in children with serum IGF-1 >2 SDS at 12 months and on the previous sample. The GH dose could be reduced a second time to 35 µg/kg·day. IGF-1 and IGFBP-3 dosages were centralized. RESULTS: Among the 49 (21 boys) children included in the study, 8 (16.3%) had an IGF-1 >2 SDS consecutively at 9 and 12 months (95% CI 7.3, 29.7). The GH dose was decreased in 6/8 children. However, IGF-1 levels were elevated at several nonconsecutive determinations in 45% (95% CI 28.4, 56.6) of the patients. CONCLUSION: A high IGF-1 level is observed in 45% of the GH SGA-treated children with a relatively high dose of GH. A 30% reduction in the GH dose causes a decrease in IGF-1 below 2 SDS in most children.


Asunto(s)
Desarrollo Infantil/efectos de los fármacos , Retardo del Crecimiento Fetal/sangre , Retardo del Crecimiento Fetal/tratamiento farmacológico , Hormona de Crecimiento Humana/administración & dosificación , Factor I del Crecimiento Similar a la Insulina/análisis , Algoritmos , Estatura/efectos de los fármacos , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Monitoreo de Drogas , Resistencia a Medicamentos , Femenino , Hormona de Crecimiento Humana/efectos adversos , Hormona de Crecimiento Humana/uso terapéutico , Humanos , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Estudios Longitudinales , Masculino , Estudios Prospectivos , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico
8.
J Dairy Sci ; 93(7): 2880-6, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20630205

RESUMEN

Lactic acid bacteria (LAB) are currently used by food industries because of their ability to produce metabolites with antimicrobial activity against gram-positive pathogens and spoilage microorganisms. The objectives of this study were to identify naturally occurring bacteriocinogenic or bacteriocinogenic-like LAB in raw milk and soft cheese and to detect the presence of nisin-coding genes in cultures identified as Lactococcus lactis. Lactic acid bacteria cultures were isolated from 389 raw milk and soft cheese samples and were later characterized for the production of antimicrobial substances against Listeria monocytogenes. Of these, 58 (14.9%) LAB cultures were identified as antagonistic; the nature of this antagonistic activity was then characterized via enzymatic tests to confirm the proteinaceous nature of the antimicrobial substances. In addition, 20 of these antagonistic cultures were selected and submitted to genetic sequencing; they were identified as Lactobacillus plantarum (n=2) and Lactococcus lactis ssp. lactis (n=18). Nisin genes were identified by polymerase chain reaction in 7 of these cultures. The identified bacteriocinogenic and bacteriocinogenic-like cultures were highly variable concerning the production and activity of antimicrobial substances, even when they were genetically similar. The obtained results indicated the need for molecular and phenotypic methodologies to properly characterize bacteriocinogenic LAB, as well as the potential use of these cultures as tools to provide food safety.


Asunto(s)
Bacteriocinas/genética , Bacteriocinas/metabolismo , Queso/microbiología , Microbiología de Alimentos , Leche/microbiología , Animales , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Bacteriocinas/análisis , Lactobacillus plantarum/aislamiento & purificación , Lactobacillus plantarum/metabolismo , Lactococcus lactis/química , Lactococcus lactis/genética , Listeria monocytogenes/efectos de los fármacos , Nisina/genética
9.
Cell Prolif ; 40(6): 936-48, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18021180

RESUMEN

OBJECTIVES: The role of stem cells in regenerative medicine is evolving rapidly. Here, we describe the application, for kidney regeneration, of a novel non-genetically modified stem cell, derived from human amniotic fluid. We show that these pluripotent cells can develop and differentiate into de novo kidney structures during organogenesis in vitro. MATERIALS AND METHODS: Human amniotic fluid-derived stem cells (hAFSCs) were isolated from human male amniotic fluid obtained between 12 and 18 weeks gestation. Green fluorescent protein and Lac-Z-transfected hAFSCs were microinjected into murine embryonic kidneys (12.5-18 days gestation) and were maintained in a special co-culture system in vitro for 10 days. Techniques of live microscopy, histology, chromogenic in situ hybridization and reverse transcriptase polymerase chain reaction were used to characterize the hAFSCs during their integration and differentiation in concert with the growing organ. RESULTS: Green fluorescent protein and Lac-Z-transfected hAFSCs demonstrated long-term viability in organ culture. Histological analysis of injected kidneys revealed that hAFSCs were capable of contributing to the development of primordial kidney structures including renal vesicle, C- and S-shaped bodies. Reverse transcriptase polymerase chain reaction confirmed expression of early kidney markers for: zona occludens-1, glial-derived neurotrophic factor and claudin. CONCLUSIONS: Human amniotic fluid-derived stem cells may represent a potentially limitless source of ethically neutral, unmodified pluripotential cells for kidney regeneration.


Asunto(s)
Líquido Amniótico/citología , Diferenciación Celular , Riñón/citología , Células Madre/citología , Animales , Biomarcadores/metabolismo , Movimiento Celular , Células Cultivadas , Humanos , Riñón/embriología , Masculino , Ratones , Ratones Endogámicos C57BL , Microinyecciones
10.
Int J Syst Evol Microbiol ; 56(Pt 8): 1931-1937, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16902033

RESUMEN

In a previous study, nitrogen-fixing isolates were recovered from the rhizosphere of maize and from surface-sterilized leaves of sugar cane cultivated in Rio de Janeiro, Brazil. On the basis of 16S rRNA gene sequence similarities, these isolates were identified as belonging to the genus Burkholderia, and whole-cell-protein profiles demonstrated that they are closely related to each other. In the present study, novel isolates were recovered from the roots of different sugar-cane varieties cultivated in diverse geographical regions of Brazil. Twenty-one nitrogen-fixing isolates were analysed using polyphasic taxonomy criteria, including DNA-DNA relatedness, 16S rRNA gene sequence similarities, fatty acid profiles, whole-cell-protein patterns and multilocus enzyme electrophoresis profiles, as well as morphological, physiological and biochemical characterization. The analysis confirmed that these isolates belong to a novel species within the genus Burkholderia, for which the name Burkholderia silvatlantica sp. nov. is proposed. The type strain, SRMrh-20(T) (=LMG 23149(T)=ATCC BAA-1244(T)), was isolated from the rhizosphere of maize var. Avantis A2345 cultivated in Seropédica, Rio de Janeiro.


Asunto(s)
Burkholderia/clasificación , Saccharum/microbiología , Zea mays/microbiología , Proteínas Bacterianas/análisis , Brasil , Burkholderia/química , Burkholderia/aislamiento & purificación , Burkholderia/fisiología , ADN Bacteriano/genética , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , Raíces de Plantas/microbiología , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Homología de Secuencia de Ácido Nucleico , Especificidad de la Especie
11.
Appl Environ Microbiol ; 72(5): 3103-10, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16672447

RESUMEN

Until recently, diazotrophy was known in only one of the 30 formally described species of Burkholderia. Novel N(2)-fixing plant-associated Burkholderia species such as B. unamae, B. tropica, and B. xenovorans have been described, but their environmental distribution is scarcely known. In the present study, the occurrence of N(2)-fixing Burkholderia species associated with different varieties of sugarcane and maize growing in regions of Mexico and Brazil was analyzed. Only 111 out of more than 900 isolates recovered had N(2)-fixing ability as demonstrated by the acetylene reduction assay. All 111 isolates also yielded a PCR product with primers targeting the nifH gene, which encodes a key enzyme in the process of nitrogen fixation. These 111 isolates were confirmed as belonging to the genus Burkholderia by using a new 16S rRNA-specific primer pair for diazotrophic species (except B. vietnamiensis) and closely related nondiazotrophic Burkholderia. In Mexico, many isolates of B. unamae (predominantly associated with sugarcane) and B. tropica (more often associated with maize) were recovered. However, in Brazil B. tropica was not identified among the isolates analyzed, and only a few B. unamae isolates were recovered from one sugarcane variety. Most Brazilian diazotrophic Burkholderia isolates (associated with both sugarcane and maize plants) belonged to a novel species, as revealed by amplified 16S rRNA gene restriction profiles, 16S rRNA gene sequencing, and protein electrophoresis. In addition, transmissibility factors such as the cblA and esmR genes, identified among clinical and environmental isolates of opportunistic pathogens of B. cenocepacia and other species of the B. cepacia complex, were not detected in any of the plant-associated diazotrophic Burkholderia isolates analyzed.


Asunto(s)
Burkholderia/clasificación , Productos Agrícolas/microbiología , Fijación del Nitrógeno , Saccharum/microbiología , Zea mays/microbiología , Brasil , Burkholderia/crecimiento & desarrollo , Burkholderia/aislamiento & purificación , Burkholderia/metabolismo , Productos Agrícolas/crecimiento & desarrollo , Genes de ARNr , México , Datos de Secuencia Molecular , Oxidorreductasas/genética , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Mapeo Restrictivo , Saccharum/crecimiento & desarrollo , Análisis de Secuencia de ADN , Especificidad de la Especie , Zea mays/crecimiento & desarrollo
12.
Eur J Endocrinol ; 146(5): 657-65, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11980621

RESUMEN

OBJECTIVE: To investigate the mechanisms determining the success or failure of refeeding therapy in malnourished elderly patients with inflammation by studying changes in plasma IGF-I, GH-binding protein (GHBP) and IGF-binding protein (IGFBP) levels and IGFBP-3 proteolysis. DESIGN AND METHODS: We studied 15 severely malnourished hospitalized elderly patients. Weight, food intake, plasma albumin, transthyretin, C-reactive protein (CRP), orosomucoid, interleukin-6 (IL-6), IGF-I, intact and proteolytically degraded IGFBP-3 and GHBP levels were determined on admission and during refeeding therapy designed to increase food intake to 40 kcal/kg body weight per day (15% protein). RESULTS: Plasma IGF-I, IGFBP-3 and GHBP levels were significantly low for age on admission in all malnourished elderly patients. They increased in nine patients as nutritional status improved (albuminemia >30 g/l; transthyretinemia >200 mg/l or weight gain >5% of initial body weight) and levels of inflammation markers decreased (group 1). In contrast, plasma IGF-I, IGFBP-3 and GHBP levels remained low in six patients in whom nutritional status failed to improve and levels of inflammation markers increased (group 2). IGF-I showed greater variations than IGFBP-3 or GHBP with respect to nutritional status. High plasma CRP and IL-6 levels were associated with high levels of IGFBP-3 proteolysis. CONCLUSION: Efficient refeeding therapy was associated with a significant increase in IGF-I plasma levels. In patients with severe and persistent inflammation, high levels of proteolysis of IGFBP-3 may have contributed to the low plasma IGF-I levels, persistence of hypercatabolism and lack of improvement in nutritional status.


Asunto(s)
Proteínas Portadoras/sangre , Alimentos , Inflamación/complicaciones , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , Trastornos Nutricionales/sangre , Trastornos Nutricionales/complicaciones , Anciano , Anciano de 80 o más Años , Proteína C-Reactiva/análisis , Femenino , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Interleucina-6/sangre , Masculino , Trastornos Nutricionales/fisiopatología , Trastornos Nutricionales/terapia , Estado Nutricional , Péptido Hidrolasas/metabolismo
13.
J Clin Endocrinol Metab ; 86(11): 5516-24, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11701730

RESUMEN

The IGFs, IGF-I and IGF-II, regulate fetal growth by activating IGF type 1 receptors (IGF-IR). We aimed to quantify the binding of IGF-I to its cognate receptors in intrauterine growth-retarded children (IUGR). We measured the affinity of the erythrocyte IGF-IR and the number of IGF-IR receptors in 17 children with retarded growth (mean height, -2.7 SD), normal levels of GH, and a history of idiopathic intrauterine growth retardation (height at birth, -10 to -2 SD; mean, -3.1 SD). These children had reduced receptor affinity (Kd = 0.47 nM; P < 0.01) and more receptors per cell [binding capacity (Bmax) = 11.7 binding sites/cell; P < 0.05)] compared with control children (Kd = 0.32 nM; Bmax = 7.8 binding sites/cell). Moreover, the distributions of Kd and Bmax suggested that there were two groups of IUGR children. Group 1 included subjects with normal receptor binding function (Kd = 0.36 nM; Bmax = 8.2 sites/cell) and normal levels of circulating IGF-I. Group 2 comprised children with low receptor affinity (Kd = 0.56 nM) and increased receptor number (Bmax = 14.7 sites/cell). This group showed significantly decreased IGF-I levels (-2.1 SD; P < 0.01). We investigated these IGF-IR binding parameters in two additional groups of growth-retarded children (Turner syndrome and patients with chronic renal failure), in whom the IGF-I axis was not believed to be the primary cause, and found that Kd and Bmax were normal or nearly normal. We also measured IGF-IR binding parameters in 4 Seckel syndrome patients with IUGR and severely retarded growth (mean height, -7.9 SD). Their receptor affinity was reduced, but not statistically different, from that in controls, and their receptor number was normal, whereas IGF-I levels were elevated. Our results suggest heterogeneous alterations in IGF-IR binding function in IUGR patients.


Asunto(s)
Retardo del Crecimiento Fetal/metabolismo , Receptor IGF Tipo 1/metabolismo , Adolescente , Niño , Preescolar , Eritrocitos/metabolismo , Hormona de Crecimiento Humana/sangre , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Radioisótopos de Yodo , Cinética , Masculino , Radioinmunoensayo
14.
Endocrinology ; 142(10): 4469-78, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11564712

RESUMEN

Reduced IGF type I receptor levels diminish postnatal growth rate and adult body weight in mice. Here, we studied the impact of experimental IGF receptor deficiency on tissue-specific growth by Cre-lox-mediated dosage of a floxed IGF-IR gene. We generated mice with a wide spectrum of receptor deficiency (5-82%), and separated them into two groups with either strong (> or =50%) IGF-IR deficiency (XS mice) or moderate deficiency (<50%, M mice). The growth of XS mice was significantly retarded from 3 wk after birth onward, with respect to M littermates. This effect was twice as strong in males as in females. Growth deficits persisted throughout adult life, and at 10-12 months, most organs and tissues showed specific weight defects. Skin, bone and connective tissue, muscle, spleen, heart, lung, and brain were the most severely affected organs in the XS males. With the exception of muscle and spleen, the same tissues were also significantly reduced in size in females, although to a lesser extent. The most severe growth defect, however, concerned adipose tissue. Fat pad size in XS males was only 29% (females, 44%) of M mice. The estimated number of adipocytes in XS male fat pads was only 21% that of M males (XS female, 27%). Lipid content per cell was significantly higher in XS adipocytes, whereas plasma glucose and insulin levels were low in XS males. Thus, IGF type I receptor deficiency produced mice with disproportionate postnatal organ growth, and these effects depended strongly on sex. A marked reduction in IGF-IR levels resulted in a major defect in adipose tissue.


Asunto(s)
Trastornos del Crecimiento/etiología , Receptor IGF Tipo 1/deficiencia , Animales , Femenino , Trastornos del Crecimiento/genética , Trastornos del Crecimiento/metabolismo , Masculino , Ratones , Ratones Transgénicos , Especificidad de Órganos , Receptor IGF Tipo 1/genética , Caracteres Sexuales , Factores Sexuales
15.
Manag Care ; 9(9): 49-52, 54, 56-7 passim, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11116663

RESUMEN

UNLABELLED: Pneumococcal disease is a common cause of morbidity and mortality in the pediatric population. Pneumococcal infections, which account for most serious bacterial disease in infancy and early childhood, are a major cause of acute otitis media, sinusitis, pneumonia, bacterial meningitis, and bacteremia. Streptococcus pneumoniae is the causative agent in a large percentage of these infections, although other microorganisms also play a role. The recent emergence of drug-resistant strains has provided a strong incentive for preventing pneumococcal infections by vaccination. However, the capsular polysaccharide pneumococcal vaccines used to immunize adults are neither immunogenic nor protective in young children due to poor antibody responses. Therefore, research has focused on development of additional immunogenic pneumococcal vaccines to provide long-term immunity in children < 2 years of age. The most promising approach has been the development of a protein-polysaccharide conjugate vaccine for the seven serotypes (4, 6B, 9V, 14, 18C, 19F, and 23F) that most commonly cause infections in childhood. An effective conjugate vaccine that protects against these serotypes has the potential to prevent 85 percent of bacteremia episodes, 83 percent of meningitis episodes, and 65 percent of otitis media cases in the U.S. among children younger than 6 years. The Food and Drug Administration (FDA) recently approved the first protein-polysaccharide conjugate vaccine to prevent invasive pneumococcal diseases in infants and toddlers < 2 years of age. This conjugated vaccine against pneumococcus uses the same technology as the successful vaccine against Haemophilus influenzae type b. It consists of an immunogenic but inert protein coupled covalently to the polysaccharide coat of the selected strains of pneumococci. The conjugated antigen induces a more powerful, T-cell-based immune response in infants, which is developed by the time they are 2 months of age. Some important questions regarding this vaccine for children < 2 years of age: Is the vaccine safe? Is it immunogenic? Is it efficacious in preventing invasive pneumococcal disease and controlling otitis media? FINDINGS: Results of three randomized double-blind trials designed to evaluate the safety and immunogenicity of this vaccine in healthy children < 2 years of age were reported within the last three years. The studies found that the vaccine is safe and highly immunogenic for all seven serotypes. The most recent study, involving over 37,000 young children, also evaluated the vaccine's efficacy, and reported that the vaccine is highly effective in preventing invasive disease and has had an impact on otitis media. CONCLUSIONS: The heptavalent pneumococcal conjugate vaccine is safe and highly effective in preventing pneumococcal meningitis and bacteremic pneumonia in young children < 2 years of age; it is less effective in preventing otitis media. Based on the results of three well-designed studies demonstrating the vaccine's safety, immunogenicity, and efficacy, the vaccine is safe and effective for active immunization of children < 2 years of age against invasive disease caused by seven Streptococcus pneumoniae serotypes included in the vaccine. At this time, there is no clear medical consensus regarding its safety and efficacy for control of otitis media in children < 2 years of age. This application has not been evaluated by the FDA. The pneumococcal conjugate vaccine should be considered experimental, and has not been shown to be safe or efficacious for Streptococcus pneumoniae disease other than that caused by the serotypes included in the vaccine and for invasive infection, such as bacteremia or meningitis, caused by other microorganisms.


Asunto(s)
Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/administración & dosificación , Centers for Disease Control and Prevention, U.S. , Medicina Basada en la Evidencia , Humanos , Lactante , National Institutes of Health (U.S.) , Otitis Media/prevención & control , Vacunas Neumococicas/economía , Ensayos Clínicos Controlados Aleatorios como Asunto , Estados Unidos , United States Food and Drug Administration , Vacunas Conjugadas/administración & dosificación , Vacunas Conjugadas/economía
16.
Manag Care ; 9(3): 56-60, 63, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11066214

RESUMEN

BACKGROUND INFORMATION: Percutaneous vertebroplasty is a therapeutic, interventional radiologic procedure that involves injection of bone cement into a cervical, thoracic, or lumbar vertebral body lesion for the relief of pain and the strengthening of bone. This procedure only recently has been introduced, and is being used for patients with lytic lesions due to bone metastases, aggressive hemangiomas, or multiple myeloma, and for patients who have medically intractable debilitating pain resulting from osteoporotic vertebral collapse. FINDINGS: Results from two uncontrolled prospective studies and several case series reports, including one with 187 patients, indicate that percutaneous vertebroplasty can produce significant pain relief and increase mobility in 70 percent to 80 percent of patients with osteolytic lesions in the vertebrae from hemangiomas, metastases, or myeloma, or with osteoporotic compression fractures. In these reports, pain relief was apparent within one to two days after injection, and persisted for at least several months up to several years. While experimental studies and preliminary clinical results suggest that percutaneous vertebroplasty can also strengthen the vertebral bodies and increase mobility, it remains to be proven whether this procedure can prevent additional fractures in the injected vertebrae. In addition, the duration of effect is not known; there were no long-term follow-up data on most of these patients, and these data may be difficult to obtain and interpret in patients with an underlying malignant process, because disease progression may confound evaluation of the treatment effect. Complications were relatively rare, although some studies reported a high incidence of clinically insignificant leakage of bone cement into the paravertebral tissues. In a few cases, the leakage of polymer caused compression of spinal nerve roots or neuralgia. Several instances of pulmonary embolism were also reported. Although patient selection criteria have not been definitely established, percutaneous vertebroplasty is considered appropriate treatment for patients with vertebral lesions resulting from osteolytic metastasis and myeloma, hemangioma, and painful osteoporotic compression fractures if the following criteria have been met: o Severe debilitating pain or loss of mobility that cannot be relieved by correct medical therapy. o Other causes of pain, such as herniated intervertebral disk have been ruled out by computed tomography or magnetic resonance imaging. o The affected vertebra has not been extensively destroyed and is at least one third of its original height. o Radiation therapy or concurrent surgical interventions, such as laminectomy, may also be required in patients with compression of the spinal cord due to ingrowth of a tumor. CONCLUSIONS: Percutaneous vertebroplasty has only recently been introduced as a treatment for osteolytic lesions and osteoporotic compression fractures of the vertebrae, but early results are promising. Up to 80 percent of patients with pain unresponsive to correct medical treatment experience a significant degree of pain relief, and few serious complications have been reported. However, relatively few patients have undergone this procedure, and there are no data from controlled clinical trials or from studies with long-term follow-up. At the present time this procedure is still in the investigational stages, but may be appropriate for patients with no other reasonable options for medical treatment.


Asunto(s)
Cementos para Huesos/uso terapéutico , Medicina Basada en la Evidencia , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Enfermedades de la Columna Vertebral/cirugía , Columna Vertebral/cirugía , Cementos para Huesos/efectos adversos , Centers for Medicare and Medicaid Services, U.S. , Análisis Costo-Beneficio , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/efectos adversos , Dolor/etiología , Dolor/cirugía , Radiología Intervencionista , Enfermedades de la Columna Vertebral/complicaciones , Estados Unidos
17.
Endocrinology ; 141(7): 2557-66, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10875258

RESUMEN

The insulin-like growth factor (IGF) system is a major regulator of somatic growth in vertebrates. Both ligands (IGF-I and IGF-II) signal via the same IGF receptor (IGF-IR). Classical IGF-IR invalidation is lethal at birth, so that conditional models are needed to study the postnatal role of this receptor. To establish a genetically inducible invalidation of IGF-IR, we targeted the IGF-IR gene using a construct that introduced a neomycin resistance cassette into intron 2, leaving the rest of the gene intact. This neomycin resistance cassette interfered with the processing of the primary transcript, resulting in there being 12% fewer IGF-binding sites at the cell surface in heterozygous mice and 41% fewer in homozygous mice. Hetero- and homozygous offspring grew more slowly than their wild-type littermates. This difference was noticeable from 4 weeks after birth and was significant from 5 weeks after birth in males. In females, the effect on postnatal growth of insertion of the neo cassette was not significant. In males, IGF-I levels increased moderately (+26%) but significantly, indicating effective feedback regulation of the IGF system. IGF-binding protein-4 (IGFBP-4) levels, estimated by Western ligand blotting, were low in homozygotes (-38%), whereas IGFBP-1, -2, and -3 levels were unaffected. In females, IGF-I and IGFBP-1, -2, -3, and -4 levels did not differ significantly among heterozygous, homozygous, and wild-type animals. We investigated the molecular mechanism involved and characterized two RNA-splicing events that could account for the decrease in IGF-IR. The phenotype of these mice developed exclusively postnatally, and body proportions were maintained. IGF-IRneo mice constitute a new model for human postnatal growth deficiency.


Asunto(s)
Animales Recién Nacidos/genética , Marcación de Gen , Trastornos del Crecimiento/genética , Empalme del ARN/genética , Receptor IGF Tipo 1/genética , Animales , Animales Recién Nacidos/crecimiento & desarrollo , Antibacterianos , Secuencia de Bases/genética , Elementos Transponibles de ADN , Evolución Molecular Dirigida , Farmacorresistencia Microbiana/genética , Femenino , Humanos , Intrones/genética , Masculino , Ratones , Datos de Secuencia Molecular , Neomicina , Fenotipo , Somatomedinas/metabolismo
18.
Growth Horm IGF Res ; 10(6): 332-41, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11161964

RESUMEN

Chronic renal failure in childhood causes severe growth retardation. The aim of the study was to identify whether changes in the IGF system could account for the growth retardation observed in children with chronic renal failure. Insulin-like growth factor (IGF-I) serum concentrations, insulin-like growth factor binding proteins (IGFBP) and/or IGF-I binding to erythrocyte type I receptor of IGF were analysed in 69 children (mean age 11.6 +/- 4.3 years) with chronic renal failure and growth retardation (mean height -2.6 +/- 1.8 SD). The study population was separated into three groups, according to their renal status, children on conservative treatment (CRF group: n = 30), on haemodialysis (ESRD group: n = 26) and those transplanted (RT group: n = 13). Nineteen of these children, some from each of the three groups, received recombinant growth hormone therapy (rhGH). Mean basal IGF-I serum concentrations were -0.7 +/- 1.2 SD in the CRF group, + 2.1 +/- 3 SD in the ESRD group and + 1.1 +/- 2 SD in the RT group. Under rhGH therapy, as height velocity improved, mean IGF-I concentrations increased up to + 3.1 +/- 0.6 SD in the CRF group, to + 6.9 +/- 2.8 SD in the ESRD group and to + 3.9 +/- 2 SD in the RT group. Basal IGFBP-3 levels, studied by Western Ligand Blot were low in the CRF group and high in the ESRD and normal in the RT groups, whereas IGFBP-2 and a 30-32 kDa IGFBP were always high in all cases. Western immunoblot analysis showed that this 30-32 kDa IGFBP was mostly composed of IGFBP-1 and IGFBP-6 in all three groups, but IGFBP-6 was particularly abundant in the ESRD group. IGFBP-6 concentrations assessed by RIA were moderately increased in CRF children (392 +/- 177 ng/mL) and very high in children on ESRD (2094 +/- 1525 ng/mL) when compared to normal values (131 +/- 42 ng/mL). Binding studies of IGF type I receptor showed that there was no particular difference in IGF-I binding between renal failure patients and normal children. In poorly growing children, especially in ESRD children and to a lesser extent in RT children, high concentrations of IGF-I and IGFBP-1, 2, 3 and 6, suggest a resistance mainly by a sequestration mechanism. Moreover, in the CRF group, especially in the younger children, low levels of IGF-I and IGFBP-3 are evocative of an associated resistance at the GH receptor level.


Asunto(s)
Proteínas de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Fallo Renal Crónico/sangre , Receptor IGF Tipo 1/sangre , Adolescente , Western Blotting , Niño , Preescolar , Eritrocitos/metabolismo , Femenino , Hormona de Crecimiento Humana/uso terapéutico , Humanos , Immunoblotting , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Proteína 6 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Fallo Renal Crónico/tratamiento farmacológico , Ligandos , Masculino , Unión Proteica , Radioinmunoensayo , Proteínas Recombinantes/uso terapéutico
19.
J Mol Endocrinol ; 23(1): 23-32, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10425444

RESUMEN

In adrenocortical tumors, the malignant phenotype is associated with rearrangements (paternal isodisomy) at the 11p15 locus and IGF-II gene overexpression, strongly suggesting that the IGF system is a major determinant of adrenocortical tumor progression. The aim of this study was to validate an in vitro model for investigating the involvement of the IGF system in adrenocortical tumorigenesis. We analyzed the production of IGF mRNA and proteins, IGF-binding proteins (IGFBPs) and IGF receptors by the NCI H295R cell line, which is derived from a human adult adrenocortical carcinoma. H295R cells were shown to proliferate for a long period (26 days) in the absence of serum or any added growth factor. Northern blot analyses showed high IGF-II mRNA contents in H295R cells. The cells secreted large amounts of IGF-II protein (14 ng/10(6) cells per 48 h) although no IGF-I protein was detected. Western ligand blot analyses of conditioned media detected the presence of large amounts of a 34 kDa protein, which was identified as IGFBP-2 by immunoblotting. The presence of high-affinity binding sites for IGF-I and IGF-II on H295R cells was shown by binding experiments using radiolabeled IGFs and confirmed by reverse transcription PCR analyses showing type 1 and type 2 IGF receptors. Proliferation of H295R cells was inhibited by anti-IGF-II antibody (45%) and by anti-type 1 IGF receptor antibody (53%) indicating that IGF-II is an autocrine growth factor for these cells and that its effects are, at least in part, mediated by the type 1 IGF receptor. These findings confirm the involvement of the IGF system in adrenocortical tumors and suggest that the H295R cell line is a suitable in vitro model for studying the molecular mechanisms of adrenocortical tumor proliferation.


Asunto(s)
Neoplasias de la Corteza Suprarrenal/fisiopatología , Carcinoma Corticosuprarrenal/fisiopatología , División Celular/fisiología , Factor II del Crecimiento Similar a la Insulina/fisiología , Neoplasias de la Corteza Suprarrenal/genética , Neoplasias de la Corteza Suprarrenal/patología , Carcinoma Corticosuprarrenal/genética , Carcinoma Corticosuprarrenal/patología , Unión Competitiva , Medio de Cultivo Libre de Suero/farmacología , Humanos , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Factor II del Crecimiento Similar a la Insulina/genética , Factor II del Crecimiento Similar a la Insulina/metabolismo , Radioisótopos de Yodo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor IGF Tipo 1/metabolismo , Células Tumorales Cultivadas/citología , Células Tumorales Cultivadas/metabolismo
20.
J Clin Endocrinol Metab ; 83(5): 1713-20, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9589681

RESUMEN

In adrenocortical tumors, malignancy is strongly associated with insulin-like growth factor II (IGF-II) gene overexpression and abnormalities at the 11p15 locus, suggesting a role for this growth factor in adrenocortical tumorigenesis. To further investigate this role, the IGF/IGF-binding protein (IGFBP) system was analyzed in 18 adrenocortical tumors, classified into 2 groups on the basis of their IGF-II messenger ribonucleic acid (mRNA) content (group 1, normal IGF-II mRNA content, mostly benign tumors; group 2, high IGF-II mRNA content, mostly malignant tumors). Group 2 tumors contained 10 times more IGF-II protein than group 1 tumors or normal adrenal tissue (P < 0.001), indicating efficient translation of IGF-II mRNA in malignant tumors. Western ligand blotting detected various functional IGFBPs in normal adrenocortical glands and tumors: a doublet of 39-42 kDa identified by immunoblotting as IGFBP-3, a band at 32 kDa, and bands at 29-30 and 24 kDa. Total IGFBP-3 protein levels were similar in the two groups of tumors. By contrast, malignant tumors differed from benign ones by specific expression of the 32-kDa IGFBP. Immunoblotting identified this 32-kDa band together with a proteolytic fragment of 25 kDa as IGFBP-2, and quantitative analysis showed significantly higher levels of total IGFBP-2 in malignant tumors than in benign tumors (P < 0.001). Despite enhanced levels of IGBP-2 protein in malignant tumors, no increase in IGFBP-2 mRNA levels was detected, suggesting post-transcriptional regulation of this IGFBP. These results confirm the major role of IGF-II in adrenocortical tumorigenesis and suggest that IGFBP-2 may be a regulator of IGF-II proliferative effects in this tumor system.


Asunto(s)
Neoplasias de la Corteza Suprarrenal/metabolismo , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Factor II del Crecimiento Similar a la Insulina/metabolismo , Adolescente , Neoplasias de la Corteza Suprarrenal/química , Adulto , Anciano , Northern Blotting , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Immunoblotting , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/análisis , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 6 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Factor II del Crecimiento Similar a la Insulina/análisis , Factor II del Crecimiento Similar a la Insulina/genética , Masculino , Persona de Mediana Edad , ARN Mensajero/análisis
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