Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Eur Radiol ; 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769164

RESUMEN

OBJECTIVES: Somatostatin receptor positron emission tomography/computed tomography (SSTR-PET/CT) using [68Ga]-labeled tracers is a widely used imaging modality for neuroendocrine tumors (NET). Recently, [18F]SiTATE, a SiFAlin tagged [Tyr3]-octreotate (TATE) PET tracer, has shown great potential due to favorable clinical characteristics. We aimed to evaluate the reproducibility of Somatostatin Receptor-Reporting and Data System 1.0 (SSTR-RADS 1.0) for structured interpretation and treatment planning of NET using [18F]SiTATE. METHODS: Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points. Each reader evaluated up to five target lesions per scan. The overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered. Inter- and intra-reader agreement was determined using the intraclass correlation coefficient (ICC). RESULTS: The ICC analysis on the inter-reader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 85%), overall scan score (ICC ≥ 90%), and the decision to recommend PRRT (ICC ≥ 85%) showed excellent agreement. However, significant differences were observed in recommending PRRT among experienced readers (ER) (p = 0.020) and inexperienced readers (IR) (p = 0.004). Compartment-based analysis demonstrated good to excellent inter-reader agreement for most organs (ICC ≥ 74%), except for lymph nodes (ICC ≥ 53%). CONCLUSION: SSTR-RADS 1.0 represents a highly reproducible and consistent framework system for stratifying SSTR-targeted PET/CT scans, even using the novel SSTR-ligand [18F]SiTATE. Some inter-reader variability was observed regarding the evaluation of uptake intensity prior to PRRT as well as compartment scoring of lymph nodes, indicating that those categories require special attention during further clinical validation and might be refined in a future SSTR-RADS version 1.1. CLINICAL RELEVANCE STATEMENT: SSTR-RADS 1.0 is a consistent framework for categorizing somatostatin receptor-targeted PET/CT scans when using [18F]SiTATE. The framework serves as a valuable tool for facilitating and improving the management of patients with NET. KEY POINTS: SSTR-RADS 1.0 is a valuable tool for managing patients with NET. SSTR-RADS 1.0 categorizes patients with showing strong agreement across diverse reader expertise. As an alternative to [68Ga]-labeled PET/CT in neuroendocrine tumor imaging, SSTR-RADS 1.0 reliably classifies [18F]SiTATE-PET/CT.

2.
Z Gerontol Geriatr ; 50(6): 538-546, 2017 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-27351557

RESUMEN

BACKGROUND: Assessment and self-assessment frequently differ, e. g. in psychosomatic disorders and complaints. At the same time the prevalence of corresponding disorders in old age is high. OBJECTIVE: This study investigated psychosocial factors from the perspective of nursing home residents and compared this self-assessment with data collected in other scientific studies with assessments by nursing home staff. The aim was to develop specific recommendations for the nursing home sector. MATERIAL AND METHODS: In this cross-sectional pilot study 256 nursing home residents (average age 81 ± 10.3 years, 69 % female, 31 % male) were questioned about their physical, psychological and social activities and well-being in semistructured anonymous interviews. Psychological screening tests were simultaneously implemented to assess symptoms of depression and dementia using the short form of the geriatric depression scale (GDS-K) and the mini mental status test (MMST). RESULTS: The results showed that 44.6 % of the residents had symptoms of depression and 76.1 % revealed signs of development of dementia. More than half assessed their physical health as good to very good. According to comparable studies nursing staff assessed persistent pain in 20.7 % of all nursing home residents while personal interviews with the residents showed that persistent pain (39.8 %) was almost twice as frequent. Life satisfaction showed a significant correlation with the following items from the self-assessment: participation in nursing home activities (r = 0.171, p = 0.008), mobility (r = -0.131; p = 0.045), emotional activity (r = 0.136, p = 0.038), subjectively experienced physical health (r = -0.420, p < 0.001) and persistent pain (r = -0.178, p = 0.006). Life satisfaction correlated highly significantly with symptoms of depression (r = -0.617, p < 0.001) and cognitive performance (r = 0.251, p = 0.001). CONCLUSION: The findings of this study encourage further research on the characteristic features of satisfied residents and (psycho)therapeutic support in order to promote factors for well-being and a positive quality of life in nursing homes.


Asunto(s)
Anciano Frágil/psicología , Hogares para Ancianos , Casas de Salud , Calidad de Vida/psicología , Ajuste Social , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/psicología , Actitud Frente a la Salud , Dolor Crónico/diagnóstico , Dolor Crónico/psicología , Estudios Transversales , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/psicología , Femenino , Alemania , Humanos , Entrevista Psicológica , Masculino , Pruebas de Estado Mental y Demencia , Proyectos Piloto , Autoevaluación (Psicología) , Estadística como Asunto , Encuestas y Cuestionarios
3.
Radiologie (Heidelb) ; 64(7): 553-558, 2024 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-38713221

RESUMEN

CLINICAL/METHODICAL ISSUE: Neuroendocrine tumors (NET) represent a heterogeneous group of rare tumors that predominantly arise in the gastrointestinal tract. At the time of initial diagnosis, the NET has already spread locoregionally in about half of the patients, and 27% of patients have already developed distant metastases. Since this plays a crucial role in therapy planning, accurate diagnostic imaging is important. STANDARD RADIOLOGICAL METHODS: Due to its high temporal and spatial resolution (multiphasic including arterial phase), computed tomography (CT) plays a decisive role in primary staging and follow-up care, while magnetic resonance imaging (MRI) with its excellent soft tissue contrast offers advantages in the assessment of parenchymal organs in the upper abdomen. METHODICAL INNOVATIONS: Somatostatin receptor (SSR) positron emission tomography (PET) provides additional functional information that not only helps to detect the primary tumor and distant metastases, but also has a significant influence on therapeutic management in a theranostic approach. PERFORMANCE: Hybrid imaging using SSR-PET/CT has proven to be particularly effective in the detection of NET. Compared to conventional imaging, it provides additional information in 68% of patients, which has a significant impact on clinical management. ACHIEVEMENTS: Imaging of NET requires the combined use of various methods such as ultrasound, CT, MRI, and PET/CT to enable accurate diagnosis and effective treatment planning. PRACTICAL RECOMMENDATIONS: SSR-PET/CT is a valuable tool for the accurate staging of neuroendocrine tumors of the gastrointestinal tract, especially with small metastases, while MRI with hepatocyte-specific contrast agent and diffusion-weighted imaging is useful for the specific assessment of liver metastases.


Asunto(s)
Neoplasias Gastrointestinales , Tumores Neuroendocrinos , Humanos , Neoplasias Gastrointestinales/diagnóstico por imagen , Neoplasias Gastrointestinales/patología , Neoplasias Gastrointestinales/diagnóstico , Imagen por Resonancia Magnética/métodos , Imagen Multimodal/métodos , Tumores Neuroendocrinos/diagnóstico por imagen , Tumores Neuroendocrinos/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos
4.
Cancer Imaging ; 23(1): 92, 2023 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-37770958

RESUMEN

BACKGROUND: Histopathology is the reference standard for diagnosing liver metastases of neuroendocrine tumors (NETs). Somatostatin receptor-positron emission tomography / computed tomography (SSR-PET/CT) has emerged as a promising non-invasive imaging modality for staging NETs. We aimed to assess the diagnostic accuracy of SSR-PET/CT in the identification of liver metastases in patients with proven NETs compared to histopathology. METHODS: Histopathologic reports of 139 resected or biopsied liver lesions of patients with known NET were correlated with matching SSR-PET/CTs and the positive/negative predictive value (PPV/NPV), sensitivity, specificity, and diagnostic accuracy of SSR-PET/CT were evaluated. PET/CT reading was performed by one expert reader blinded to histopathology and clinical data. RESULTS: 133 of 139 (95.7%) liver lesions showed malignant SSR-uptake in PET/CT while initial histopathology reported on 'liver metastases of NET´ in 127 (91.4%) cases, giving a PPV of 91.0%. Re-biopsy of the initially histopathologically negative lesions (reference standard) nevertheless diagnosed 'liver metastases of NET' in 6 cases, improving the PPV of PET/CT to 95.5%. Reasons for initial false-negative histopathology were inadequate sampling in the sense of non-target biopsies. The 6 (4.3%) SSR-negative lesions were all G2 NETs with a Ki-67 between 2-15%. CONCLUSION: SSR-PET/CT is a highly accurate imaging modality for the diagnosis of liver metastases in patients with proven NETs. However, we found that due to the well-known tumor heterogeneity of NETs, specifically in G2 NETs approximately 4-5% are SSR-negative and may require additional imaging with [18F]FDG PET/CT.


Asunto(s)
Neoplasias Hepáticas , Tumores Neuroendocrinos , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tumores Neuroendocrinos/diagnóstico por imagen , Tumores Neuroendocrinos/patología , Receptores de Somatostatina , Tomografía de Emisión de Positrones/métodos , Neoplasias Hepáticas/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Sensibilidad y Especificidad , Radiofármacos
5.
J Cell Biol ; 127(6 Pt 2): 2021-36, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7806579

RESUMEN

The secreted polypeptide transforming growth factor-beta (TGF-beta) exerts its multiple activities through type I and II cell surface receptors. In epithelial cells, activation of the TGF-beta signal transduction pathways leads to inhibition of cell proliferation and an increase in extracellular matrix production. TGF-beta is widely expressed during development and its biological activity has been implicated in epithelial-mesenchymal interactions, e.g., in branching morphogenesis of the lung, kidney, and mammary gland, and in inductive events between mammary epithelium and stroma. In the present study, we investigated the effects of TGF-beta on mouse mammary epithelial cells in vitro. TGF-beta reversibly induced an alteration in the differentiation of normal mammary epithelial NMuMG cells from epithelial to fibroblastic phenotype. The change in cell morphology correlated with (a) decreased expression of the epithelial markers E-cadherin, ZO-1, and desmoplakin I and II; (b) increased expression of mesenchymal markers, such as fibronectin; and (c) a fibroblast-like reorganization of actin fibers. This phenotypic differentiation displays the hallmarks of an epithelial to mesenchymal transdifferentiation event. Since NMuMG cells make high levels of the type I TGF-beta receptor Tsk7L, yet lack expression of the ALK-5/R4 type I receptor which has been reported to mediate TGF-beta responsiveness, we evaluated the role of the Tsk7L receptor in TGF-beta-mediated transdifferentiation. We generated NMuMG cells that stably overexpress a truncated Tsk7L type I receptor that lacks most of the cytoplasmic kinase domain, thus function as a dominant negative mutant. These transfected cells no longer underwent epithelial to mesenchymal morphological change upon exposure to TGF-beta, yet still displayed some TGF-beta-mediated responses. We conclude that TGF-beta has the ability to modulate E-cadherin expression and induce a reversible epithelial to mesenchymal transdifferentiation in epithelial cells. Unlike other transdifferentiating growth factors, such as bFGF and HGF, these changes are accompanied by growth inhibition. Our results also implicate the Tsk7L type I receptor as mediating the TGF-beta-induced epithelial to mesenchymal transition.


Asunto(s)
Receptores de Activinas Tipo I , Diferenciación Celular/efectos de los fármacos , Glándulas Mamarias Animales/citología , Mesodermo/fisiología , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Animales , Secuencia de Bases , Biomarcadores , Northern Blotting , Western Blotting , Cadherinas/aislamiento & purificación , Células Cultivadas , Reactivos de Enlaces Cruzados , Células Epiteliales , Epitelio/efectos de los fármacos , Epitelio/crecimiento & desarrollo , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Mesodermo/citología , Ratones , Datos de Secuencia Molecular , Inhibidores de Proteínas Quinasas , Proteínas Serina-Treonina Quinasas , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/clasificación , Receptores de Factores de Crecimiento Transformadores beta/genética
6.
J Cell Biol ; 118(3): 715-26, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1639853

RESUMEN

Transforming growth factor-beta (TGF-beta) is a potent mediator of cell proliferation and extracellular matrix formation, depending on the cell type and the physiological conditions. TGF-beta is usually secreted in a "latent" complex that needs activation before it can exert its effects. Several observations correlate increased expression of TGF-beta 1 with tumorigenesis. To evaluate the physiological relevance of increased TGF-beta 1 synthesis in tumor cells we established cell clones overexpressing TGF-beta 1 and observed the resulting physiological changes in TGF-beta overproducing cells in vitro and in vivo. As a model system we used the human E1A-transformed 293 tumor cells, which are insensitive to the direct growth modulatory effects of TGF-beta. The selection of this cell line allows an assessment of physiological alterations independent of TGF-beta induced proliferative changes. The use of two TGF-beta 1 expression vectors containing either the natural or a modified TGF-beta 1 precursor cDNA permitted the establishment of separate 293 cell lines overexpressing latent or active TGF-beta. Comparison of the resulting changes in glycolytic rate, adhesiveness and integrin and plasminogen activator expression established that, in vitro, both types of clones behaved similarly, indicating that expression of latent TGF-beta induces autocrine changes in the tumor cells and thus suggesting that some level of cell-associated activation occurs. TGF-beta overexpression resulted in an increased metabolic rate due to enhanced glycolysis, a property long associated with tumor cells. This increased glycolysis was not associated with altered proliferation. Cells overexpressing TGF-beta also displayed enhanced fibronectin mRNA and plasminogen activator synthesis and increased adhesiveness in vitro. They showed enhanced survival when plated sparsely on plastic in the absence of serum, and attached more readily to laminin. In addition, synthesis of several beta 1 integrins, in particular the alpha 1/beta 1, alpha 2/beta 1, and alpha 3/beta 1, all of which recognize laminin, were enhanced. Finally, cells overexpressing active TGF-beta, but not latent TGF-beta, also showed increased tumorigenicity in nude mice. Thus, an increase in endogenous TGF-beta synthesis confers several proliferation-independent phenotypic changes which may be of significance for the survival of the tumor cell inoculum or its subsequent growth, and for tumor formation and development. In the case of cells expressing active TGF-beta, the release of active TGF-beta into the vicinity of the tumor cells may also result in a more hospitable environment for tumor growth.


Asunto(s)
Adhesión Celular , Transformación Celular Neoplásica , Factor de Crecimiento Transformador beta/fisiología , Animales , Secuencia de Bases , División Celular , ADN , Endopeptidasas/genética , Endopeptidasas/metabolismo , Fibronectinas/genética , Fibronectinas/metabolismo , Expresión Génica , Humanos , Integrinas/genética , Integrinas/metabolismo , Ratones , Ratones Desnudos , Datos de Secuencia Molecular , Invasividad Neoplásica , Neoplasias Experimentales/etiología , Neoplasias Experimentales/metabolismo , Factor de Crecimiento Transformador beta/biosíntesis , Factor de Crecimiento Transformador beta/genética , Células Tumorales Cultivadas
7.
Science ; 260(5112): 1335-8, 1993 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-8388126

RESUMEN

Transforming growth factor-beta (TGF-beta) is a multifunctional protein that regulates cell proliferation and differentiation and extracellular matrix production. Although two receptor types, the type I and type II receptors, have been implicated in TGF-beta-induced signaling, it is unclear how the many activities of TGF-beta are mediated through these receptors. With the use of cells overexpressing truncated type II receptors as dominant negative mutants to selectively block type II receptor signaling, the existence of two receptor pathways was shown. The type II receptors, possibly in conjunction with type I receptors, mediate the induction of growth inhibition and hypophosphorylation of the retinoblastoma gene product pRB. The type I receptors are responsible for effects on extracellular matrix, such as the induction of fibronectin and plasminogen activator inhibitor I, and for increased JunB expression. Selective inactivation of the type II receptors alters the TGF-beta response in a similar manner to the functional inactivation of pRB, suggesting a role for pRB in the type II, but not the type I, receptor pathway.


Asunto(s)
Receptores de Superficie Celular/fisiología , Receptores de Factores de Crecimiento Transformadores beta , Factor de Crecimiento Transformador beta/farmacología , Animales , División Celular/efectos de los fármacos , Línea Celular , ADN/biosíntesis , Regulación hacia Abajo , Fibronectinas/biosíntesis , Inhibidor 1 de Activador Plasminogénico/biosíntesis , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas c-jun/genética , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Superficie Celular/genética , Proteína de Retinoblastoma/metabolismo , Transducción de Señal , Transfección , Factor de Crecimiento Transformador beta/fisiología
8.
Science ; 262(5135): 900-2, 1993 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-8235612

RESUMEN

Transforming growth factor-beta (TGF-beta) and activin signal primarily through interaction with type I and type II receptors, which are transmembrane serine-threonine kinases. Tsk 7L is a type I receptor for TGF-beta and requires coexpression of the type II TGF-beta receptor for ligand binding. Tsk 7L also specifically bound activin, when coexpressed with the type IIA activin receptor. Tsk 7L could associate with either type II receptor and the ligand binding specificity of Tsk 7L was conferred by the type II receptor. Tsk 7L can therefore act as type I receptor for both activin and TGF-beta, and possibly other ligands.


Asunto(s)
Inhibinas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Factores de Crecimiento/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Receptores de Activinas , Activinas , Secuencia de Bases , Cartilla de ADN , Sustancias de Crecimiento/metabolismo , Humanos , Datos de Secuencia Molecular , Pruebas de Precipitina , Proteínas Recombinantes de Fusión/metabolismo , Transducción de Señal , Transfección
9.
Science ; 260(5112): 1344-8, 1993 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-8388127

RESUMEN

Transforming growth factor-beta (TGF-beta) affects cellular proliferation, differentiation, and interaction with the extracellular matrix primarily through interaction with the type I and type II TGF-beta receptors. The type II receptors for TGF-beta and activin contain putative serine-threonine kinase domains. A murine serine-threonine kinase receptor, Tsk 7L, was cloned that shared a conserved extracellular domain with the type II TGF-beta receptor. Overexpression of Tsk 7L alone did not increase cell surface binding of TGF-beta, but coexpression with the type II TGF-beta receptor caused TGF-beta to bind to Tsk 7L, which had the size of the type I TGF-beta receptor. Overexpression of Tsk 7L inhibited binding of TGF-beta to the type II receptor in a dominant negative fashion. Combinatorial interactions and stoichiometric ratios between the type I and II receptors may therefore determine the extent of TGF-beta binding and the resulting biological activities.


Asunto(s)
Receptores de Superficie Celular/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Chlorocebus aethiops , Clonación Molecular , Humanos , Ratones , Datos de Secuencia Molecular , Proteínas Serina-Treonina Quinasas , Codorniz , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Superficie Celular/química , Receptores de Superficie Celular/genética , Receptores de Factores de Crecimiento Transformadores beta , Transfección
10.
Science ; 276(5309): 111-3, 1997 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-9082980

RESUMEN

TRAIL (also known as Apo-2L) is a member of the tumor necrosis factor (TNF) ligand family that rapidly induces apoptosis in a variety of transformed cell lines. The human receptor for TRAIL was found to be an undescribed member of the TNF-receptor family (designated death receptor-4, DR4) that contains a cytoplasmic "death domain" capable of engaging the cell suicide apparatus but not the nuclear factor kappa B pathway in the system studied. Unlike Fas, TNFR-1, and DR3, DR4 could not use FADD to transmit the death signal, suggesting the use of distinct proximal signaling machinery. Thus, the DR4-TRAIL axis defines another receptor-ligand pair involved in regulating cell suicide and tissue homeostasis.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Apoptosis , Glicoproteínas de Membrana/metabolismo , Receptores del Factor de Necrosis Tumoral/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Secuencia de Aminoácidos , Proteínas Reguladoras de la Apoptosis , Proteínas Portadoras/metabolismo , Línea Celular , Proteína de Dominio de Muerte Asociada a Fas , Humanos , Ligandos , Datos de Secuencia Molecular , FN-kappa B/metabolismo , Proteínas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF , Receptores del Factor de Necrosis Tumoral/química , Receptores del Factor de Necrosis Tumoral/genética , Proteínas Recombinantes de Fusión/metabolismo , Transducción de Señal , Factor 1 Asociado a Receptor de TNF , Ligando Inductor de Apoptosis Relacionado con TNF , Transfección , Células Tumorales Cultivadas
13.
Mol Microbiol ; 2(1): 9-17, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28776786

RESUMEN

The nucleotide sequence of the structural gene, scrA, which codes for sucrose-specific EnzymellScr (EIIScr ) of the phosphoenolpyruvate-dependent carbohydrate: phosphotransferase system (PTS), was determined. EllScr requires an Enzymelll, the product of the gene crr, for full activity. The gene scrA is preceded immediately by a classical Shine-Dalgarno sequence (AAGAGGGTA). It contains 1368 nucleotides with an increased GC-content (58%) corresponding to a polypeptide of 455 amino acid residues (Mr 47 500). The protein has the hydropathic profile (average hydropathy +0.82) of an integral membrane protein lacking extended α-helical structures and a signal peptide. Comparison with the sequence of the ß-glucoside-specific Enzymell (EllBgl , 625 amino acids, Mr 66480; Bramley and Kornberg, 1987a; Schnetz et al., 1987) revealed strong homologies between EllScr and the first 458 residues of EllBgl . The 162 carboxyterminal residues of EllBgl , however, showed a high homology with the sequence of Enzymelll (Nelson et al., 1984), a homology also described recently by Bramley and Kornberg (1987b). The evolutionary and functional significance of the similarities with four other Enzymesll is discussed.

14.
Mol Endocrinol ; 7(2): 189-98, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8385738

RESUMEN

We have evaluated the effects of retinoic acid as a differentiating agent on two pluripotential mesenchymal stem cell lines, the mouse cell line C3H-10T1/2 (10T1/2), which has the capacity to differentiate in vitro into myoblasts, adipocytes, chondrocytes, and osteoblasts, and the rat cell line ROB-C26 (C26), which can, in culture, give rise to adipocytes, myoblasts, and osteoblasts. Retinoic acid (10(-6) M) reduces the incidence of myoblast and adipocyte formation and induces or increases alkaline phosphatase expression and responsiveness to PTH, two indicators of the osteoblastic phenotype. Because transforming growth factor-beta (TGF beta) superfamily members, including the different TGF beta isoforms and the bone morphogenetic proteins (BMPs), are thought to play a role in regulating bone and cartilage formation, and because exogenous TGF beta and BMP-2 have already been found to modulate osteoblastic differentiation of C26 and 10T1/2 cells, we evaluated the endogenous expression of these factors in both cell lines cultured in the presence or absence of retinoic acid. Our data show that C26 and 10T1/2 cells constitutively express a broad spectrum of TGF beta superfamily members. However, this pattern of expression is dramatically altered in response to retinoic acid. Specifically, expression of TGF beta 1 and especially TGF beta 2 is strongly increased, whereas TGF beta 3 expression is down-regulated. These changes are accompanied by a striking decline in TGF beta receptor expression levels at the cell surface. Furthermore, BMP-2 and -4 expression are decreased after treatment with retinoic acid, whereas vgr-1/BMP-6 expression is induced in C26 cells, but decreased in 10T1/2 cells. These results clearly show a dynamic changing pattern of TGF beta superfamily expression consequent to the induction of osteogenic differentiation and provide the first indication that TGF beta receptor down-regulation may be an essential part of this differentiation process. These data also establish the C26 and 10T1/2 cell lines as convenient in vitro model systems for exploring the autoregulation of osteogenic differentiation by members of the TGF beta superfamily.


Asunto(s)
Familia de Multigenes , Osteoblastos/efectos de los fármacos , Células Madre/efectos de los fármacos , Factor de Crecimiento Transformador beta/genética , Tretinoina/farmacología , Animales , Biomarcadores , Diferenciación Celular/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Ratones , Ratones Endogámicos C3H , Osteoblastos/citología , Ratas , Receptores de Superficie Celular/biosíntesis , Receptores de Factores de Crecimiento Transformadores beta , Células Madre/citología , Estimulación Química
15.
J Bone Miner Res ; 11(7): 938-45, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8797114

RESUMEN

The therapeutic utility of a single application of recombinant human transforming growth factor-beta (hTGF-beta) has not been previously tested in large osseous wounds in primates. Sixteen calvarial defects, 25 mm in diameter, were prepared in four adult male baboons (Papio ursinus). In each animal, three defects were treated with increasing doses of hTGF-beta 1 in conjunction with baboon insoluble collagenous bone matrix as carrier (5, 30, and 100 micrograms of hTGF-beta 1/g of matrix). The fourth defect was implanted with collagenous matrix without hTGF-beta 1 as control. Serial undecalcified sections were prepared from the specimens harvested on day 30. Islands of cartilage and endochondral osteogenesis were found in hTGF-beta 1-treated defects, irrespective of the doses used. Histomorphometry of the defect site showed no significant differences between control and hTGF-beta 1-treated specimens with regard to bone and osteoid volumes. However, analysis of the regenerated tissue in proximity to the defect margins only showed that, on average, greater amounts of bone formed in specimens that were treated with 5 and 30 micrograms of hTGF-beta 1 when compared with controls. This suggests a possible effect on osteoblastic cells originating from the periosteal and endosteal spaces of the severed calvaria. Overall, however, this difference has no therapeutic implications for the healing of large cranial wounds in primates. The present findings indicate that a single application of hTGF-beta 1, in conjunction with collagenous matrix, results in limited chondro-osteogenesis in defects of membranous bone of adult baboons.


Asunto(s)
Cartílago/efectos de los fármacos , Colágeno/farmacología , Osteogénesis/efectos de los fármacos , Papio/fisiología , Cráneo/efectos de los fármacos , Factor de Crecimiento Transformador beta/farmacología , Análisis de Varianza , Animales , Cartílago/crecimiento & desarrollo , Humanos , Masculino , Proteínas Recombinantes/farmacología , Cráneo/lesiones , Solubilidad , Especificidad de la Especie , Estimulación Química
16.
Neurology ; 40(4): 712-3, 1990 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2320251

RESUMEN

We report a case of vertical ocular motor apraxia in a 4-year old boy whom we have followed for 2 years. The patient had no upward and downward voluntary movements of the eyes since birth, but horizontal movements were normal. He achieved gaze changes in the vertical plane by combined blinks and head movements. Magnetic resonance imaging demonstrated bilateral lesions at the mesencephalic-diencephalic junction.


Asunto(s)
Apraxias/diagnóstico , Encéfalo/patología , Nervio Oculomotor , Apraxias/diagnóstico por imagen , Apraxias/fisiopatología , Encéfalo/diagnóstico por imagen , Preescolar , Movimientos Oculares , Humanos , Imagen por Resonancia Magnética , Masculino , Tomografía Computarizada por Rayos X
17.
Arch Ophthalmol ; 119(4): 516-29, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11296017

RESUMEN

OBJECTIVE: To demonstrate spontaneous regression of large, clinically symptomatic optic pathway gliomas in patients with and without neurofibromatosis type 1 (NF-1). METHODS: Patient cases were collected through surveys at 2 consecutive annual meetings of the North American Neuro-Ophthalmology Society (NANOS) and through requests on the NANOSNET Internet listserv. Serial documentation of tumor signal and size, using magnetic resonance imaging in 11 patients and computed tomography in 2 patients, was used to evaluate clinically symptomatic optic pathway gliomas. All tumors met radiologic criteria for the diagnosis of glioma and 4 patients had biopsy confirmation of their tumors. In 3 patients, some attempt at therapy had been made many years before regression occurred. In one of these, radiation treatment had been given 19 years before tumor regression, while in another, chemotherapy had been administered 5 years before signal changes in the tumor. In the third patient, minimal surgical debulking was performed 1 year before the tumor began to shrink. RESULTS: Spontaneous tumor shrinkage was noted in 12 patients. Eight patients did not have NF-1. In an additional patient without NF-1, a signal change within the tumor without associated shrinkage was detected. Tumor regression was associated with improvement in visual function in 10 of 13 patients, stability of function in 1, and deterioration in 2. CONCLUSIONS: Large, clinically symptomatic optic gliomas may undergo spontaneous regression. Regression was seen in patients with and without NF-1. Regression may manifest either as an overall shrinkage in tumor size, or as a signal change on magnetic resonance imaging. A variable degree of improvement in visual function may accompany regression. The possibility of spontaneous regression of an optic glioma should be considered in the planning of treatment of patients with these tumors.


Asunto(s)
Neoplasias Encefálicas/fisiopatología , Regresión Neoplásica Espontánea , Neurofibromatosis 1/fisiopatología , Glioma del Nervio Óptico/fisiopatología , Adolescente , Neoplasias Encefálicas/diagnóstico , Niño , Preescolar , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Neurofibromatosis 1/diagnóstico , Glioma del Nervio Óptico/diagnóstico , Tomografía Computarizada por Rayos X
18.
Surv Ophthalmol ; 45(6): 489-92, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11425355

RESUMEN

Several chorioretinal lesions have been observed that are associated with bone marrow transplantation (BMT), such as cotton-wool spots, macular stars, ischemic changes due to microangiopathy, "BMT retinopathy" and choroidal infiltration. Central serous retinopathy (CSR) has rarely been described in the BMT setting. We present a patient who underwent allogeneic BMT and subsequently developed severe chronic graft versus host disease (CGvHD) complicated with CSR.


Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Enfermedad Injerto contra Huésped/etiología , Enfermedades de la Retina/etiología , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Femenino , Angiografía con Fluoresceína , Glucocorticoides/uso terapéutico , Enfermedad Injerto contra Huésped/diagnóstico , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/terapia , Enfermedades de la Retina/diagnóstico , Enfermedades de la Retina/tratamiento farmacológico , Trasplante Homólogo , Agudeza Visual
19.
Surv Ophthalmol ; 40(1): 62-8, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8545804

RESUMEN

A 71-year-old woman developed complete third nerve palsy and total blindness of the right eye one month after completing a course of radiotherapy for sphenoid sinus carcinoma over a 13-month period. Differential diagnosis included recurrence of the tumor, radiation-induced second neoplasm, empty sella with chiasmal prolapse and secondary chiasmal arachnoid adhesions, and radionecrosis. Magnetic resonance imaging demonstrated gadolinium contrast enhancement of the right intracranial optic nerve and chiasm, suggesting a radionecrosis process.


Asunto(s)
Ceguera/etiología , Carcinoma/radioterapia , Quiasma Óptico/efectos de la radiación , Nervio Óptico/efectos de la radiación , Neoplasias de los Senos Paranasales/radioterapia , Traumatismos por Radiación/etiología , Seno Esfenoidal/efectos de la radiación , Anciano , Carcinoma/etiología , Quimioterapia Adyuvante , Cisplatino/uso terapéutico , Diagnóstico Diferencial , Femenino , Fluorouracilo/uso terapéutico , Humanos , Imagen por Resonancia Magnética , Neoplasias Inducidas por Radiación/etiología , Neoplasias Primarias Secundarias/etiología , Enfermedades del Nervio Oculomotor/diagnóstico , Enfermedades del Nervio Oculomotor/etiología , Atrofia Óptica/etiología , Quiasma Óptico/patología , Nervio Óptico/patología , Neoplasias de los Senos Paranasales/etiología , Campos Visuales
20.
Br J Ophthalmol ; 88(11): 1380-6, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15489477

RESUMEN

AIM: To evaluate the efficacy of periocular triamcinolone acetonide for the treatment of thyroid associated ophthalmopathy (TAO), and the presence of ocular or systemic adverse effects. METHODS: A multicentre prospective pilot study was performed on patients diagnosed with Graves' ophthalmopathy less than 6 months before entry to the study. Patients were admitted to the study and were randomised into two groups: treatment and control. The treatment group received four doses of 20 mg of triamcinolone acetate 40 mg/ml in a peribulbar injection to the inferolateral orbital quadrant. Both groups were evaluated by measuring the area of binocular vision without diplopia on a Goldmann perimeter and the size of the extraocular muscles on computed tomography (CT) scans. Ophthalmological and systemic examinations were done to rule out ocular and systemic adverse effects. Follow up was 6 months for both groups. RESULTS: 50 patients were eligible for the study. 41 patients completed the study. There was an increase in the area of binocular vision without diplopia in the treatment group (Sigma initial: mean 231.1 (SD 99.9) and final absolute change, mean 107.1 (SD 129.0)) compared to the control group (Sigma initial: mean 350.7 (SD 86.5) and final absolute change, mean -4.5 (SD 67.6)). The sizes of the extraocular muscles were reduced in the treatment group (mean (inferior rectus initial values): 1.3 (0.7), final percentage change: -13.2 (25.7), medial rectus initial values: 1.2 (0.6), final percentage change: -8.2 (20.7), superior rectus-levator palpebrae initial values: 1.2 (0.6), final percentage change: -9.5 (29.1), lateral rectus initial values: 1.0 (0.4), final percentage change: -11.5 (20.6)) compared to the control group (inferior rectus initial values: 0.9 (0.3), final percentage change: -4.0 (21.5), medial rectus initial values: 0.9 (0.3), final percentage change: 0.6 (22.4), superior rectus-levator palpebrae initial values: 0.9 (0.3), final percentage change: 12.5 (37.5), lateral rectus initial values: 0.9 (0.4), final percentage change: -0.5 (31.6)). Both measurements (degree of diplopia and muscle thickness) were statistically significant between groups (initial - final). No systemic or ocular adverse effects were found. CONCLUSIONS: Triamcinolone administered as a periocular injection is effective in reducing diplopia and the sizes of extraocular muscles in TAO ophthalmopathy of recent onset. This form of treatment is not associated with systemic or ocular side effects.


Asunto(s)
Antiinflamatorios/administración & dosificación , Glucocorticoides/administración & dosificación , Enfermedad de Graves/tratamiento farmacológico , Triamcinolona Acetonida/administración & dosificación , Adulto , Anciano , Antiinflamatorios/efectos adversos , Diplopía/prevención & control , Movimientos Oculares , Femenino , Glucocorticoides/efectos adversos , Enfermedad de Graves/patología , Enfermedad de Graves/fisiopatología , Humanos , Inyecciones/métodos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Triamcinolona Acetonida/efectos adversos , Visión Binocular/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA