RESUMEN
A carotid-cavernous fistula is a life-threatening condition characterised by an abnormal communication between the carotid arterial vessels and the cavernous venous system. Although these fistulae can arise spontaneously, they mainly occur after trauma, especially road traffic accidents, falls and penetrating cranial or orbital injuries. The mainstay of treatment involves endovascular embolization, but in those patients where this is not possible or where embolization fails, direct surgical intervention and ligation of the artery may be necessary. Here we describe an interesting case of a suspected carotid-cavernous fistula which turned out to be cavernous sinus syndrome secondary to lymphoma.
Asunto(s)
Fístula del Seno Cavernoso de la Carótida/fisiopatología , Embolización Terapéutica , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/cirugía , Adolescente , Angiografía Cerebral , Humanos , Masculino , Tomografía Computarizada por Rayos XRESUMEN
AIM: The primary aim of this pilot study was to trial a method of assessing bruises in a population of disabled children. If the method was found to be sufficiently robust it would be our intention to undertaking a more extensive observational study. BACKGROUND: Less is known about normal bruising patterns in children with disability than in those without. It is important that the method used to assess bruising is objective and repeatable. In an effort to define and improve repeatability, we employed a novel bruise measurement template which was printed onto transparent acetate sheets. METHOD: Twenty primary school age children, the majority of whom were non-ambulant and severely disabled with cerebral palsy, underwent full skin examination. The template was used to assess any bruises seen. A comparison was then made between measurements made by experienced paediatricians using the template and using a standard tape measure on a series of bruise images in 25 photographs. RESULTS: The majority of children in our pilot were found to have bruises, with one child having 6 and one 7 bruises. This comparative study showed that the two techniques had a very similar precision and that the template was easy to use. Greater precision would require a tighter measurement protocol, whether with a template or a tape measure. CONCLUSIONS: Further evaluation of the application of such a template would be worthwhile. We would suggest that our finding of some bruising in this population of disabled children is borne in mind whenever bruising is found in a non-ambulant child.
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Parálisis Cerebral , Maltrato a los Niños/diagnóstico , Contusiones/epidemiología , Contusiones/etiología , Niño , Deambulación Dependiente/lesiones , Niños con Discapacidad , Femenino , Humanos , Masculino , Proyectos Piloto , Factores de RiesgoRESUMEN
Oligodendrogliomas may be divided into those with deletion of chromosomes 1p and 19q (Del+), and those without (Del-). Del+ tumours show better survival and chemoresponsiveness but the reason for this difference is unknown. We have investigated whether these subgroups differ in (a) apoptotic index, (b) the proportion of cells licensed for DNA replication but not in-cycle, and (c) the relative length of G1-phase. Fluorescence in situ hybridisation with probes to 1p and 19q was used to determine the deletion status of 54 oligodendrogliomas, including WHO grades II and III. The apoptotic index was determined using counts of apoptotic bodies. Replication-licensed non-proliferating cells were determined from the Mcm2 minus Ki67 labelling index, whilst the geminin to Ki67 ratio was used as a measure of the relative length of G1. Del+ oligodendrogliomas showed a higher apoptotic index than Del- tumours (P=0.037); this was not accounted for by differences in tumour grade or in proliferation. There were no differences in the Mcm2-Ki67 index or in the geminin/Ki67 ratio between the subgroups, but grade III tumours showed a higher proportion of licensed non-proliferating cells than grade II tumours (P=0.001). An increased susceptibility to apoptosis in oligodendrogliomas with 1p+/-19q deletion may be important in their improved clinical outcome compared to Del- tumours.
Asunto(s)
Apoptosis/fisiología , Proliferación Celular , Deleción Cromosómica , Cromosomas Humanos Par 1/genética , Oligodendroglioma/genética , Adulto , Apoptosis/genética , Supervivencia Celular , Citogenética/métodos , Replicación del ADN , Femenino , Humanos , Hibridación Fluorescente in Situ/métodos , Antígeno Ki-67/metabolismo , Masculino , Persona de Mediana Edad , Oligodendroglioma/clasificación , Estudios RetrospectivosRESUMEN
We present an unusual case of extracranial metastasis of glioblastoma multiforme (GBM) to the parotid gland and cervical lymph nodes. The patient had previously undergone two craniotomies to debulk a left frontal GBM, followed by radiotherapy. After the second craniotomy, while waiting for chemotherapy, the patient was re-admitted with a short history of a painful swelling of his left parotid gland. The initial diagnosis was infective parotitis; however, as there was no improvement with broad-spectrum antibiotics, CT was undertaken, which revealed a mass in the parotid gland with a necrotic centre and enlarged cervical lymph nodes. Parotid gland biopsy revealed a parotid GBM metastasis. This case illustrates how GBM behaves in an aggressive manner even outside the CNS. A brief review of the literature and of the theories, which might explain the extra-neural metastasis of this tumour is also presented.
Asunto(s)
Neoplasias Encefálicas/patología , Glioblastoma/secundario , Neoplasias de la Parótida/secundario , Parotiditis/etiología , Enfermedad Aguda , Adulto , Resultado Fatal , Glioblastoma/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias de la Parótida/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
The convergence point of growth-signalling pathways that control cell proliferation is the initiation of genome replication, the core of which is the assembly of pre-replicative complexes (pre-RCs), resulting in chromatin being 'licensed' for DNA replication in the subsequent S phase. The Mcm2-7 complex is a core constituent of the pre-RC, whose recruitment to replication origins is dependent on the Cdt1 loading factor. Geminin is a potent inhibitor of the initiation of DNA replication by preventing Mcm2-7 assembly at origins via its interaction with Cdt1, ensuring genomic integrity through suppression of re-initiation events in S phase. Here we investigate the regulation of Ki67, Mcm2, p21, caspase 3 and Geminin in a series of 55 oligodendrogliomas to provide an integrated picture of how cellular proliferation and programmed cell death are dysregulated in these tumours. Geminin does not behave as an inhibitor of cell proliferation, its labelling index rising with increasing growth fraction as defined by Ki67 or Mcm2 expression. Geminin is expressed in a higher proportion of cells in higher grade tumours (P<0.001) and shows a strong correlation to proliferation and replication licensing (P<0.01), but not apoptosis. Increasing tumour anaplasia is not associated with loss of Geminin. Importantly, the G1 phase of the proliferative cell cycle, as assessed by the Geminin/Ki67 ratio, shortens with increasing anaplasia, providing new potential algorithms for prognostic assessment. Origin licensing proteins thus provide powerful novel tools for assessment of tumour cell cycle kinetics in routinely processed surgical biopsy material.
Asunto(s)
Neoplasias Encefálicas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Ciclo Celular/fisiología , Ciclinas/metabolismo , Replicación del ADN , Antígeno Ki-67/metabolismo , Oligodendroglioma/metabolismo , Adulto , Animales , Neoplasias Encefálicas/patología , Caspasa 3 , Caspasas/metabolismo , Proteínas de Ciclo Celular/inmunología , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Femenino , Geminina , Humanos , Inmunoglobulina G/inmunología , Cinética , Masculino , Persona de Mediana Edad , Componente 2 del Complejo de Mantenimiento de Minicromosoma , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Proteínas Nucleares/metabolismo , Oligodendroglioma/patología , ConejosRESUMEN
Stanniocalcin (STC) is a glycoprotein hormone that is secreted by the corpuscle of Stannius, an endocrine gland of bony fish, and is involved in calcium and phosphate homeostasis. The related mammalian proteins, STC1 and STC2, are expressed in a wide variety of tissues. The ovaries have the highest level of STC1, and this increases during pregnancy and lactation. STC1 is present in breast ductal epithelium, and its expression is induced by BRCA1, a tumor suppressor gene that has an important role in breast and ovarian cancer. The expression of STC2 is induced by estrogen, and there is a positive correlation between the level of expression of estrogen receptor and expression of both STC1 and STC2 in breast cancer. This article reviews the data currently available regarding the mammalian STCs, and discusses the roles they may play in normal physiology and in breast and other cancers.
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Calcio/metabolismo , Glicoproteínas/fisiología , Neoplasias/metabolismo , Animales , Hormonas , Humanos , Péptidos y Proteínas de Señalización Intercelular , Neoplasias/patología , Comunicación Paracrina , Receptores de Estrógenos/metabolismoRESUMEN
Despite advances in the molecular pathogenesis of glioblastoma multiforme, no reliable prognostic markers have been identified. We analysed telomerase activity and telomere lengths in glioblastoma multiformes from 77 patients. 19 patients (25%) had tumours with the alternative-lengthening-of-telomere (ALT) phenotype. Median survival for patients with this phenotype was 542 days (95% CI 114-970) compared with 247 days (224-270) for glioblastoma multiformes with normal telomeres (p=0.0003). Cox's regression analysis showed that this association is independent of age. In patients with non-ALT tumours, telomerase activity did not affect survival (median 287 [199-375] vs 236 [230-242] days, p=0.275). We conclude that ALT is a prognostic indicator for patients with glioblastoma multiforme.
Asunto(s)
Astrocitoma/enzimología , Glioblastoma/enzimología , Telomerasa/metabolismo , Telómero/genética , Adulto , Astrocitoma/mortalidad , Astrocitoma/patología , Glioblastoma/mortalidad , Glioblastoma/patología , Humanos , Persona de Mediana Edad , Fenotipo , Pronóstico , Análisis de SupervivenciaRESUMEN
Functional MRI (fMRI) may provide a means of locating areas of eloquent cortex that can be used to guide neurosurgeons in their quest to maximize intracerebral tumour resection whilst minimizing post-procedural neurological deficits. This work aimed to develop and provide an initial assessment of such a technique. 19 patients with mass lesions close to the primary motor cortex underwent fMRI at 1.5T. A single shot echo planar technique was used to acquire data corresponding to right and left hand movement. Resultant activation maps were used to aid pre-surgical planning. Data was used in conjunction with an intraoperative navigation system in 13 cases. Activation was attributed to primary motor, primary somatosensory or supplementary motor cortex in 17 of 19 subjects. No permanent changes in motor deficit were detected post surgery. The additional information provided by fMRI, particularly when incorporated into a neuronavigation guided craniotomy, was deemed highly valuable to the neurosurgeon as it enabled safe resection of tumour in anatomical locations previously deemed to be too high risk for safe resection using conventional (non-fMRI-guided) technique. This observation is reinforced by the fact that no patients suffered permanent neurological deficit after radical tumour debulking (surgical estimates >90% tumour resection).
Asunto(s)
Neoplasias Encefálicas/cirugía , Imagen por Resonancia Magnética/métodos , Corteza Motora , Adolescente , Adulto , Anciano , Neoplasias Encefálicas/diagnóstico , Femenino , Humanos , Cuidados Intraoperatorios/métodos , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios/métodosRESUMEN
BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) is a common and serious neurologic emergent condition. We tested the hypothesis that multimodality MR imaging depicts changes in cerebral blood flow SAH, before any surgical or endovascular intervention, and that the frequency of these changes increases with time after ictus. METHODS: We prospectively examined 37 patients with suspected SAH and three with symptoms of acute stroke but who subsequently had SAH. Routine CT and multimodality MR imaging were performed within 18 h of presentation. Standard MR imaging, diffusion-weighted MR imaging, time-of-flight MR angiography, and dynamic first-pass gadolinium-enhanced MR perfusion imaging were performed. Images were reviewed for abnormalities in cerebral blood flow, ischemia, and infarction. Nine patients did not have SAH at CT and CSF investigations. Of 31 patients with proved SAH, 13 were examined during the acute stage (within 4 d of ictus) and 18, during the subacute stage (4-14 d after ictus). RESULTS: MR imaging showed alteration in cerebral blood flow parameters in 16 of 31 patients before surgery or endovascular treatment. The frequency of blood flow changes and associated complications increased with worsening clinical grade and increasing time after ictus. CONCLUSION: Multimodality MR imaging provides information not available from CT in patients with SAH. MR imaging shows oligemic and ischemic areas in SAH before surgery or endovascular treatment. MR imaging is a simple noninvasive method of assessing cerebral blood flow and its complications in SAH. It can be performed in a clinical environment.
Asunto(s)
Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Hemodinámica , Imagen por Resonancia Magnética , Hemorragia Subaracnoidea/patología , Hemorragia Subaracnoidea/fisiopatología , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVES: To measure the sensitivity and specificity of five MRI sequences to subarachnoid haemorrhage. METHODS: Forty one patients presenting with histories suspicious of subarachnoid haemorrhage (SAH) were investigated with MRI using T1 weighted, T2 weighted, single shot fast spin echo (express), fluid attenuation inversion recovery (FLAIR), and gradient echo T2* sequences, and also by CT. Lumbar puncture was performed in cases where CT was negative for SAH. Cases were divided into acute (scanned within 4 days of the haemorrhage) and subacute (scanned after 4 days) groups. RESULTS: The gradient echo T2* was the most sensitive sequence, with sensitivities of 94% in the acute phase and 100% in the subacute phase. Next most sensitive was FLAIR with values of 81% and 87% for the acute and subacute phases respectively. Other sequences were considerably less sensitive. CONCLUSIONS: MRI can be used to detect subacute and acute subarachnoid haemorrhage and has significant advantages over CT in the detection of subacute subarachnoid haemorrhage. The most sensitive sequence was the gradient echo T2*.
Asunto(s)
Encéfalo/patología , Imagen por Resonancia Magnética , Hemorragia Subaracnoidea/patología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y EspecificidadRESUMEN
Stanniocalcin 1 (STC1) and stanniocalcin 2 (STC2) are two recently identified mammalian peptide hormones. STC1 plays a role in calcium and phosphate homoeostasis, while the role of STC2 is unknown. We examined a human fibrosarcoma cell line, HT1080, that has high steady-state STC1 and STC2 mRNA levels, to determine whether these proteins are secreted. Following incubation of HT1080 cells with (32)P, labelled STC1 and STC2 were found to be secreted into the medium. STC1 was phosphorylated in vitro by protein kinase C (PKC). In vitro and in vivo phosphorylation both occurred exclusively on serine and the phosphopeptide maps were similar, suggesting that PKC might be the in vivo kinase. STC2 was phosphorylated in vitro by casein kinase II (CK2), in vitro and in vivo phosphorylation were exclusively on serine and the phosphopeptide maps were indistinguishable. Phosphorylation of STC2 in intact cells resulted from the action of an ecto-protein kinase, since exogenous STC2 was phosphorylated by HT1080 cells and no phosphorylated STC2 was detectable inside the cells. The ectokinase activity was abolished by heparin and GTP could substitute for ATP as the phosphate donor, indicative of an ecto-CK2-like activity. The in vitro CK2 phosphorylation site was shown by matrix-assisted laser-desorption ionization-time-of-flight MS to be a single serine located between Ser-285 and Ser-298 in the C-terminal region of STC2. This is the first report of the secretion of STC1 or STC2 from mammalian cells. We conclude that these human fibrosarcoma cells express both STC1 and STC2 as secreted phosphoproteins in vivo, with STC2 being phosphorylated by an ecto-CK2-like enzyme.
Asunto(s)
Fibrosarcoma/metabolismo , Glicoproteínas/metabolismo , Hormonas/metabolismo , Western Blotting , Quinasa de la Caseína II , Medios de Cultivo Condicionados/metabolismo , Electroforesis en Gel de Poliacrilamida , Glicoproteínas/química , Hormonas/química , Humanos , Inmunohistoquímica , Hibridación in Situ , Péptidos y Proteínas de Señalización Intercelular , Cinética , Fosforilación , Proteína Quinasa C/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , ARN Mensajero/metabolismo , Proteínas Recombinantes/metabolismo , Serina/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Células Tumorales CultivadasRESUMEN
Bony fish use the glycoprotein hormone stanniocalcin (STC) to counteract hypercalcaemia. This is achieved through dual mechanisms involving gill calcium uptake inhibition and stimulation of renal inorganic phosphate reabsorption. Human STC (hSTC-1) shows considerable homology with both rat and mouse STC (mSTC) and their mRNA is expressed in a wide range of tissues. In fish, STC is produced by endocrine glands known as the corpuscles of Stannius but in mammals the widespread expression is suggestive of a paracrine rather than an endocrine role. In order to determine the distribution and strucutral characteristics of hSTC-1, the recombinant protein was expressed in bacteria, purified by metal-ion affinity chromatography, and a study was made of the likely epitopes for raising an antibody. This novel hSTC-1 antibody was used to test the purification protocol. Since the role of mammalian STC is largely unknown, the specific distribution of STC needed to be addressed. To test the specificity of the antibody, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting was undertaken in homogenised rat bladder, ovary and kidney.
Asunto(s)
Glicoproteínas/análisis , Hormonas/análisis , Riñón/química , Ovario/química , Vejiga Urinaria/química , Secuencia de Aminoácidos , Animales , Especificidad de Anticuerpos , Western Blotting , Dicroismo Circular , Electroforesis en Gel de Poliacrilamida , Femenino , Glicoproteínas/química , Glicoproteínas/inmunología , Hormonas/química , Hormonas/inmunología , Humanos , Ratones , Microscopía Confocal , Datos de Secuencia Molecular , Fragmentos de Péptidos/inmunología , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes/inmunologíaRESUMEN
Lack of telomere maintenance during cell replication leads to telomere erosion and loss of function. This can result in telomere associations which probably cause the dicentric chromosomes seen in some tumour cells. One mechanism of telomere maintenance in dividing cells is the action of telomerase, a ribonucleoprotein enzyme that adds TTAGGG repeats onto telomeres and compensates for their shortening during cell division. Over 90 per cent of extracranial malignant neoplasms have been found to have telomerase activity. This study sought to determine if there was a relationship between absence of telomerase activity and presence of dicentric chromosomes in meningiomas and to what extent the other main group of central nervous system tumours, the gliomas, expressed telomerase activity. Telomerase activity was measured on 25 meningiomas and 29 gliomas. Four of the meningiomas were atypical variants and 11 were positive for dicentric chromosomes. Twenty-five of 29 gliomas were glioblastoma multiforme tumours. Measures were taken to ensure absence of false positives due to primer-dimer interaction and false negatives due to protein degradation or the presence of Taq polymerase inhibitors. All 25 meningiomas and the four low-grade gliomas (WHO grade II) were telomerase activity-negative. Seven (28 per cent) of the 25 glioblastoma multiforme tumours showed telomerase activity. The absence of telomerase activity in meningiomas and the high frequency of telomere associations support the hypothesis that these tumours are benign, transformed but pre-crisis. The relatively low frequency of telomerase activity in the malignant glioblastoma multiforme suggests that most of these tumours may have other mechanisms of telomere maintenance and that the potentially therapeutic telomerase inhibitors will not be of great value in the future management of the majority of patients suffering from these tumours.
Asunto(s)
Neoplasias Encefálicas/genética , Aberraciones Cromosómicas , Glioma/genética , Neoplasias Meníngeas/genética , Meningioma/genética , Proteínas de Neoplasias/metabolismo , Telomerasa/metabolismo , Neoplasias Encefálicas/enzimología , Glioblastoma/enzimología , Glioblastoma/genética , Glioma/enzimología , Humanos , Cariotipificación , Neoplasias Meníngeas/enzimología , Meningioma/enzimología , Telómero/genéticaRESUMEN
Aneurysmal bone cyst is a benign fibroosseous lesion which rarely occurs in the orbit. We report on a 7-year-old girl with aneurysmal bone cyst of the orbit who presented with painless proptosis and diplopia. Optic nerve compression resulted in field loss and delayed visual evoked potentials. Radiological and histological features are discussed. The lesion was excised via a frontal craniotomy and the orbital roof reconstructed with a prefabricated titanium plate. Post-operatively a rapid resolution of the proptosis and diplopia followed. Previous reported cases of this rare entity in the orbit are also reviewed.
Asunto(s)
Quistes Óseos Aneurismáticos/diagnóstico , Enfermedades Orbitales/diagnóstico , Quistes Óseos Aneurismáticos/cirugía , Niño , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Enfermedades Orbitales/cirugía , Tomografía Computarizada por Rayos XRESUMEN
Pneumocephalus is an uncommon complication of ventriculo-peritoneal (VP) shunts. We present a case of pneumocephalus secondary to a VP shunt in a patient with an acoustic neuroma. The site of the cerebrospinal fluid fistula was found to be into an extensive petrous apex air cell system due to tumour erosion of the internal auditory canal.
RESUMEN
Diffuse meningeal spread and dural infiltration by pleomorphic xanthoastrocytoma occurring after initial diagnosis of a left frontotemporal lesion is reported. The unusual pattern of spread and aggressive course for a pleomorphic xanthoastrocytoma are discussed.
RESUMEN
We present a case of subarachnoid hemorrhage attributed to rupture of an aneurysm 18 months after endovascular occlusion. The aneurysm was diagnosed after the patient had a seizure; however, there was no evidence of subarachnoid hemorrhage. Angiography at 6 months revealed a totally occluded aneurysm. This case illustrates that the long-term results of endovascular occlusion remain uncertain.
Asunto(s)
Aneurisma Roto/complicaciones , Embolización Terapéutica , Aneurisma Intracraneal/complicaciones , Hemorragia Subaracnoidea/etiología , Aneurisma Roto/diagnóstico por imagen , Angiografía Cerebral , Femenino , Humanos , Aneurisma Intracraneal/diagnóstico por imagen , Aneurisma Intracraneal/terapia , Persona de Mediana Edad , Radiografía Intervencional , Recurrencia , Factores de TiempoRESUMEN
Reiterative in vitro selection-amplification from random oligonucleotide libraries allows the identification of molecules with specific functions such as binding to specific proteins. The therapeutic usefulness of such molecules depends on their high affinity and nuclease resistance. Libraries of RNA molecules containing 2'amino-(2'NH2)- or 2'fluoro-(2'F)-2'-deoxypyrimidines could yield ligands with similar nuclease resistance but not necessarily with similar affinities. This is because the intramolecular helices containing 2'NH2 have lower melting temperatures (Tm) compared with helices containing 2'F, giving them thermodynamically less stable structures and possibly weaker affinities. We tested these ideas by isolating high-affinity ligands to human keratinocyte growth factor from libraries containing modified RNA molecules with either 2'NH2 or 2'F pyrimidines. We demonstrated that 2'F RNA ligands have affinities (Kd approximately 0.3-3 pM) and bioactivities (Ki approximately 34 pM) superior to 2'NH2 ligands (Kd approximately 400 pM and Ki approximately 10 nM). In addition, 2'F ligands have extreme thermo-stabilities (Tm approximately 78 degrees C in low salt, and specificities).
Asunto(s)
Desoxirribonucleótidos/química , Desoxirribonucleótidos/farmacología , Factores de Crecimiento de Fibroblastos , Sustancias de Crecimiento/metabolismo , ARN/metabolismo , ARN/farmacología , Células 3T3/efectos de los fármacos , Células 3T3/metabolismo , Animales , Secuencia de Bases , Sitios de Unión , Desoxirribonucleótidos/metabolismo , Estabilidad de Medicamentos , Factor 10 de Crecimiento de Fibroblastos , Factor 7 de Crecimiento de Fibroblastos , Humanos , Ratones , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , ARN/química , Ribonucleasas/metabolismo , Especificidad por Sustrato , TemperaturaRESUMEN
In the new NHS those who provide services for disabled children need to measure and demonstrate their effectiveness, but there are no easily available outcome measures for use by child development centres and teams. The development of an alternative approach, using a series of statements of good practice, is described. Parents of children with cerebral palsy were asked to participate in semistructured interviews, to ascertain the value and relevance of these quality statements. Parents were most concerned about the standard of news breaking and early follow up, the sharing of information, and the supply and repair of equipment. The findings were used to modify the quality checklist and it is proposed that this should form the basis of a "charter for disabled children and their families'.
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Actitud Frente a la Salud , Parálisis Cerebral/terapia , Necesidades y Demandas de Servicios de Salud , Padres/psicología , Garantía de la Calidad de Atención de Salud , Personas con Discapacidad , Educación Especial , Educación en Salud , Londres , Cuidados a Largo Plazo/normas , Padres/educación , Relaciones Profesional-Familia , Medicina Estatal/normas , Revelación de la VerdadRESUMEN
We have identified a group of DNA molecules that bind to platelet-derived growth factor (PDGF)-AB with subnanomolar affinity from a randomized DNA library using in vitro selection. Individual ligands cloned from the affinity-enriched pool bind to PDGF-AB and PDGF-BB with comparably high affinity (Kd approximately 10(-10) M) and to PDGF-AA with lower affinity (> 10(-8) M), indicating specific recognition of the PDGF B-chain in the context of the hetero- or homodimer. The consensus secondary structure motif for most of the high-affinity ligands is a three-way helix junction with a three-nucleotide loop at the branch point. Photo-cross-linking experiments with 5-iodo-2'-deoxyuridine-substituted ligands establish a point contact between a thymidine nucleotide in the helix junction loop region and phenylalanine 84 of the PDGF-B chain. Representative minimal DNA ligands inhibit the binding of 125I-PDGF-BB but not of 125I-PDGF-AA to PDGF alpha- or beta-receptors expressed in porcine aortic endothelial (PAE) cells in a concentration-dependent manner with half-maximal effects of approximately 1 nM. The same ligands also exhibit a similar inhibitory effect on PDGF-BB-dependent [3H]thymidine incorporation in PAE cells expressing the PDGF beta-receptors. These DNA ligands represent a novel class of specific and potent antagonists of PDGF-BB and, by inference, PDGF-AB.