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Biomedical subjects

A Cerase

Publications and source records attributed to A Cerase.

At least 19 recordsLinked to original sources
PubMed2007

Multiple binding of methyl-CpG and polycomb proteins in long-term gene silencing events.

Epigenetic regulation is involved in the maintenance of long-term silencing phenomena, such as X-inactivation and genomic imprinting in mammals. Gene repression is mediated by several mechanisms, such as histone modifications, DNA methylation, and recruitment of Polycomb proteins. To understand the mechanistic relationships between these mechanisms for stable gene silencing, we analyzed the mechanisms of X- and Y-inactivation of the PAR2 gene SYBL1, previously showed to be regulated by concerted epigenetic mechanisms. Maintenance of stable repression occurs via the recruitment of both MBDPs and PRC2 complexes to SYBL1 promoter. Their binding is equally sensitive to defective DNA methylation seen in cells derived from ICF syndrome patients. Multiple occupancy is a feature shared within long-term repressed genes, such as the X-inactivated PGK1 and the imprinted IGF2. MBD2, MBD3, and MeCP2 occupy SYBL1 promoter simultaneously, as revealed by sequential ChIP. We did not find this co-occurring binding when looked for members of PRC2 complex together with any of the methyl-binding proteins. Furthermore, in co-transfection assays, MECP2 can silence methylated SYBL1 promoter, whereas the mutated protein fails. However, RNA interference of endogenous MECP2 does not induce the expression of the inactive SYBL1 alleles, suggesting that its silencing activity can be replaced by the other methyl-binding proteins. Our data suggest that maintenance of long-term silencing involves multiple layers of epigenetic control functionally redundant. PRC2 and MBD proteins could collaborate to different phases of this process, the former possibly recruiting DNMTs to the silenced promoters, the latter dictating the lock of the transcription.

Cell Line↗
PubMed2006

Human herpesvirus-6B active infection associated with relapsing bilateral anterior optic neuritis.

BACKGROUND AND OBJECTIVES: Human herpesvirus-6 (HHV-6) is the causative agent of exanthem subitum. Both HHV-6 variants, A and B, have been associated with central nervous system (CNS) diseases, suggesting a wide neuropathogenic potential. We describe a case of recurrent bilateral anterior optic neuritis with HHV-6 active infection associated with clinical relapses. CASE REPORT: A 23-year old woman presented with progressive visual impairment, bilateral papillitis and painful ocular movements. Nested polymerase chain reaction (PCR) for DNA viruses, HHV-6 variant specific real time quantitative PCR, serological analysis and retrotranscription PCR (RT-PCR) for HHV-6 mRNA transcripts were performed. Nested PCR in PBMC and CSF samples was negative for all viruses but positive for HHV-6 DNA, subtyped as HHV-6B. The disease had a relapsing/remitting course. During relapses PBMC samples remained positive for HHV-6 DNA, and HHV-6 active infection was confirmed by the presence of anti-HHV-6 IgM and of HHV-6 U27 mRNA transcript. High viremia levels and relapses were overlapping. After the last relapse, the patient was successfully treated with gancyclovir. CONCLUSIONS: The case reported here suggests a possible association of HHV-6 in bilateral optic neuritis. HHV-6 could be monitored when bilateral optic neuritis is identified, in order to establish an appropriate antiviral therapy.

Adult↗
PubMed2006

Maintenance of X- and Y-inactivation of the pseudoautosomal (PAR2) gene SPRY3 is independent from DNA methylation and associated to multiple layers of epigenetic modifications.

Maintenance of X-inactivation is achieved through a combination of different repressive mechanisms, thus perpetuating the silencing message through many cell generations. The second human X-Y pseudoautosomal region 2 (PAR2) is a useful model to explore the features and internal relationships of the epigenetic circuits involved in this phenomenon. Recently, we demonstrated that DNA methylation plays an essential role for the maintenance of X- and Y-inactivation of the PAR2 gene SYBL1; here we report that the silencing of the second repressed PAR2 gene, SPRY3, appears to be independent of DNA methylation. In contrast to SYBL1, the inactive X and Y alleles of SPRY3 are not reactivated in cells treated with a DNA methylation inhibitor and in cells from ICF (immunodeficiency, centromeric instability, facial anomalies) syndrome patients, which have mutations in the DNA methyltransferase gene DNMT3B. SPRY3 X- and Y-inactivation is associated with a differential enrichment of repressive histone modifications and the recruitment of Polycomb 2 group proteins compared to the active X allele. Another major factor in SPRY3 repression is late replication; the inactive X and Y alleles of SPRY3 have delayed replication relative to the active X allele, even in ICF syndrome cells where the closely linked SYBL1 gene is reactivated and advanced in replication. The relatively stable maintenance of SPRY3 silencing compared with SYBL1 suggests that genes without CpG islands may be less prone to reactivation than previously thought and that genes with CpG islands require promoter methylation as an additional layer of repression.

Alleles↗
PubMed2003

Endovascular treatment of a cavernous sinus dural arteriovenous fistula by transvenous embolisation through the superior ophthalmic vein via cannulation of a frontal vein.

We describe a new approach for transvenous embolisation of cavernous sinus dural arteriovenous fistulae through the superior ophthalmic vein (SOV), i.e., via percutaneous cannulation of a frontal vein. Modern neurointerventional angiographic materials make it possible to reach the SOV in this way without puncturing it in the orbit or a surgical exposure. Orbital phlebography should still be in the repertoire of interventional neuroradiology units in large centres.

Aged↗
PubMed2001

Destructive spondyloarthropathy of the cervical spine in long-term hemodialyzed patients: a five-year clinical radiological prospective study.

OBJECTIVE: To describe the radiographic features and progression of cervical spine destructive spondyloarthropathy (DSA) in hemodialyzed patients, and to evaluate the relationship between this disease and patient characteristics, biochemical values, and hemodialysis duration. DESIGN AND PATIENTS: Standard radiographs, and lateral flexion and extension views of the cervical spine, were performed annually for 5 years in 31 hemodialyzed patients who were divided into three groups at the commencement of the study: those showing (I) DSA, (II) vertebral rim erosions (VRE) without DSA, and (III) absence of DSA and VRE. Magnetic resonance (MR) imaging and computed tomography (CT) were performed in seven and two patients respectively. The imaging features were evaluated for the presence and progression of spondyloarthropathy and correlated with clinical and biochemical variables. Statistical analysis was performed using one-way analysis of variance. RESULTS: The duration of hemodialysis appeared to be the main predictive factor (P=0.0003) for DSA, which was found in six patients (19%). DSA was found to correlate with higher levels of beta2-microglobulin (P<0.00001), parathyroid hormone (P<0.05), and alkaline phosphatase (P<0.05). Clinical symptoms were minimal. In two patients, MR imaging revealed changes mimicking spondylodiscitis. In another patient, CT of the craniocervical junction showed bone resorption due to a pseudotumor, and basilar invagination. CONCLUSIONS: DSA of the cervical spine is often clinically silent. Pathogenesis of DSA may be multifactorial but its progression is most influenced by the duration of hemodialysis. On MR imaging, DSA may mimic spondylodiscitis.

Adult↗
PubMed2001

Capillaroscopic findings in erosive and nodal osteoarthritis of the hands.

Osteoarthritis of the hands is a very common disease that can present a large number of different clinic pictures, such as nodal (NOA) and erosive (EOA) forms. EOA in particular is a rare subset of hand osteoarthritis characterised by faster destructive changes involving the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints. In the early stages of the disease the differential diagnosis from other arthritides, such as rheumatoid or seronegative arthritis, may pose a challenge. Nailfold capillaroscopy is a non-invasive technique that allows the in vivo study of the microvascular environment. In this study the authors have compared the capillaroscopic microvascular patterns in 56 patients with EOA, in 46 patients with NOA, and in 50 normal controls. The abnormalities that could be found in EOA patients were similar to those described by some authors in patients with psoriatic arthritis. The authors discuss the significance of these abnormalities and the possible relationship between EOA and psoriatic arthritis.

Aged↗
PubMed2001

Coats disease: smaller volume of the affected globe.

PURPOSE: To determine whether a significant smaller volume of the affected globe, compared with that of the normal globe, is an additional feature of Coats disease. MATERIALS AND METHODS: Ocular globe volume was assessed in 13 children (11 boys, two girls; age range, 0.6-14 years; mean age, 4.1 years) with Coats disease and in 18 (eight boys, 10 girls; age range, 0.5-12 years; mean age, 3.6 years) with unilateral retinoblastoma. Orbital computed tomographic scans were available for all children; magnetic resonance images were available for 11 children-seven with Coats disease and four with retinoblastoma. For volume estimation, anteroposterior and equatorial diameters of ocular globes were measured. Statistical analysis was conducted with univariate and multivariate methods. RESULTS: In children with Coats disease, the mean volume of the affected globe was 4,877.03 mm(3) (range, 2,951.47-6,284.70 mm(3)) and that of the normal globe, 6,018.00 mm(3) (range, 4,062.32-7,509.26 mm(3)). In children with retinoblastoma, the mean volume of the affected globe was 4,557.06 mm(3) (range, 1,612.01-7,463.00 mm(3)) and that of the normal globe, 4,402.11 mm(3) (range, 1,360.46- 7,463.00 mm(3)). The Coats disease population had a significantly smaller volume of the affected globe (z = -3.1009; P =.002); the retinoblastoma population did not have a statistically significant trend toward a bigger affected globe volume (z = -1.7064; P =.088). The difference between the affected globe volume and the normal globe volume in children with Coats disease was the only significant independent variable (P =.005). CONCLUSION: A significantly smaller volume of the affected globe is an additional feature of Coats disease.

Adolescent↗
PubMed2001

MR brain imaging of fucosidosis type I.

SUMMARY: Fucosidosis is a rare autosomal recessive lysosomal storage disease with the main clinical findings of progressive neuromotor deterioration, seizures, coarse facial features, dysostosis multiplex, angiokeratoma corporis diffusum, visceromegaly, recurrent respiratory infections, and growth retardation. Fucosidosis type I rapidly evolves toward a progressive neurologic deterioration and death. We report MR imaging findings of the brain of three patients with fucosidosis type I, including previously unreported findings, to expand the knowledge of the neuroradiologic spectrum of the disease.

Atrophy↗
PubMed2001

Spontaneous onset of CSF otorrhea from a facial canal fistula in an adult: case report.

The purpose of this report is to describe a 64-year-old woman who presented an 8 month history of recurrent spontaneous cerebrospinal fluid leakage into the left middle ear. High resolution computed tomography and computed tomography cisternography showed only a mild protrusion of the tympanic segment of the left facial canal into the ipsilateral middle ear but no definitive fistula. At surgical exploration, cerebrospinal fluid leakage resulted from a fistula in the tympanic segment of the left facial canal. In conclusion, in the adult patient reported herein, the fistula leading to spontaneous CSF otorrhea was identified definitely only intraoperatively. Furthermore, although there were no signs or symptoms of facial nerve dysfunction, it was located in a rare site such as the second segment of the facial canal. When the clinical history, physical examination, and laboratory analysis are strongly suggestive for spontaneous CSF otorrhea, surgical exploration is mandatory even if neuroimaging evaluation is negative or questionable.

Cerebrospinal Fluid Otorrhea↗
PubMed2000

Regression after biopsy of a pilocytic opticochiasmatic astrocytoma in a young adult without neurofibromatosis.

Serial MRI over 60 months demonstrated regression after biopsy of a pilocytic opticochiasmatic astrocytoma in a 20-year-old woman with no signs of neurofibromatosis, together with improvement in vision. The patient did not receive radio- or chemotherapy. Close MRI follow-up of optic gliomas is recommended. Aggressive treatment should be limited to cases with clear clinical and radiological progression.

Adult↗
PubMed2000

Tunneling Schmorl's nodes in an elderly woman treated for acute lymphoblastic leukemia.

We present a 70-year-old woman with pre-B acute lymphoblastic leukemia in whom serial imaging studies showed the development of multiple vertebral collapse, and communicating superior and inferior Schmorl's nodes creating a longitudinal channel ("tunneling" Schmorl's nodes) through the anterior aspect of T12 to L3 vertebral bodies of her osteoporotic thoracolumbar spine. This was observed after achieving complete remission of the disease and during maintenance therapy. The finding is felt to be secondary to iatrogenic exacerbation of osteoporosis.

Aged↗
PubMed2000

Occipital condylar fractures: a review.

The purpose of this review article is to summarize the epidemiology, pertinent anatomy, mechanisms of injury, and classification systems of occipital condylar fractures (OCFs), as well as their clinical presentation and screening, the importance of computed tomography (CT) for detection, and current treatment options. The authors emphasize the rate of occurrence of OCFs, which may be detected in as many as 16% of patients with craniocervical injury. Clinical presentation is not specific, and OCF is not readily diagnosed at physical examination. Failure to diagnose may result in substantial morbidity, and thus accurate diagnosis is mandatory for both therapeutic and medicolegal implications. The diagnosis is most likely to be made with CT. Thin-section CT technique is the method of choice to evaluate the traumatized craniocervical junction. OCFs should be suspected in all patients sustaining high-energy blunt trauma to the head and/or upper cervical spine, resulting from axial loading, lateral bending and/or rotation, and/or direct blow. Besides a CT study assessing potential intracranial injuries, these patients require CT of the craniocervical junction. Radiologists should be aware of the types of OCFs and associated injuries.

Cervical Vertebrae↗
PubMed2000

Craniocervical junction involvement in rheumatoid arthritis: a clinical and radiological study.

OBJECTIVE: To make a comparative evaluation of different imaging techniques for studying the craniocervical junction involvement in patients with rheumatoid arthritis (RA). Upper cervical spine involvement was compared with clinical and immunological data. METHODS: Patients (n = 47) underwent plain radiographs and computerized tomography (CT) and magnetic resonance (MR) study of the craniocervical junction. Neurological examination following clinical signs of possible atlantoaxial involvement was performed in all patients following the Ranawat classification. RESULTS: Radiographic and MR images showed craniocervical involvement in 41.3% and 61% of the patients, respectively. Immunological data were not correlated with imaging findings, whereas Ranawat class II and III of neurological involvement seem to be predictive of atlantoaxial alteration. CONCLUSION: Conventional radiography allowed us to detect 41.3% of patients with craniocervical involvement, but only in advanced stages of the disease. MR imaging had the unique potential of direct and detailed synovial visualization, especially in the gadolinium enhanced axial images, resulting in the early diagnosis of craniocervical RA.

Adolescent↗
PubMed1998

The current role of radiography in the assessment of skeletal tumors and tumor-like lesions.

Radiography offers more information than any other imaging modality in the study of bone lesions and remains the cornerstone for the differential diagnosis of skeletal tumors and tumor-like lesions thanks to its higher specificity in detecting tumor morphologic hallmarks. the radiographic features that help the radiologist make the diagnosis of a bone tumor or tumor-like lesion, or at least narrow the diagnostic possibilities, include patterns of bone destruction (geographic, moth-eaten and permeated), lesion margins (from sclerotic rim to ill-defined margin), internal characteristics of the lesion (non-matrix producing tumors, non-mineralized matrix producing tumors, mineralized matrix producing tumors), type of host bone response (medullary or periosteal), location (femur, tibia, humerus, etc.), site (metaphysis, diaphysis or epiphysis), and position (central, eccentric or periosteal) of the lesion in the skeletal system and in the individual bone, soft tissue involvement, and single or multiple lesion nature. Patterns of bone destruction, margins, and reactive changes in the host bone clearly depict the growth rate of a bone lesion, that is its biologic activity; the matrix of the lesion, as well as lesion location, site and position may allow a specific diagnosis. This general information coupled with clinical information helps define whether the lesion is neoplastic or non-neoplastic, benign or malignant, primary or metastatic, and will help further direct the subsequent work-up. CT may be indicated for the optimal assessment of tumor matrix especially in complex anatomical sites, such as the spine, pelvis and hindfoot. The main role of MRI lies in local tumor staging, especially for planning limb-salving resections. Biopsy is the definitive diagnostic procedure and should be carried out only after the appropriate diagnostic and staging tests. Whenever a bone lesion is suspected, clinical-radiologic pathologic correlation is essential to make a more accurate diagnosis and to improve patient care.

Biopsy↗
PubMed1998

Skeletal benign bone-forming lesions.

The imaging features of benign osseous lesions of the bone are often characteristic and suggestive of a specific diagnosis. This is particularly true for skeletal benign bone-forming lesions such as enostosis, osteoma, osteoid osteoma and osteoblastoma. Enostosis or bone island is an incidental finding in the axial skeleton (pelvis, spine, ribs) of asymptomatic patients; it appears as a small (0.2-2 cm) round to oval sclerotic area with irregular, radiating ('thorny') spicules peripherally. Osteoma is a benign slow-growth tumor and usually an incidental finding in cranial sinuses, vault and mandible, and presenting as a homogeneous, sharply defined bone mass arising from bone surface; its signs and symptoms are rare and depend on the tumor size and location--e.g. sinusitis, headache, exophthalmos, diplopia. Osteoid osteoma is a painful highly vascularized benign tumor usually affecting the long bone diaphysis cortex of young patients; it generally appears as a small radiolucent nidus with or without central calcification and surrounding bone sclerosis on radiographs, and as a 'hot' spot on scintigraphy. CT is the method of choice for the definite location of the nidus especially in sites of complex anatomy, such as the spine, pelvis and hindfoot. Osteoblastoma is a rare tumor, histologically similar to osteoid osteoma but with a significantly different clinical potential because of the possibilities of postoperative recurrence, of its locally aggressive behavior or, rarer still, malignant transformation; the spine and long bones are affected in more than half the cases. Its radiologic appearance is not always distinctive and usually characterized by a lytic lesion with varying bone production and expansile behavior; CT and MRI are required for the diagnosis of spinal osteoblastomas. When a bone-producing tumor or tumor-like lesion is suspected but no specific diagnosis can be made, the knowledge of the range of the imaging findings of these lesions will allow a suitably ordered differential diagnosis. Radiography is the single most effective imaging method in this respect. CT is required for the tumors in complex anatomical sites, such as the spine, pelvis and hindfoot, as well as for the optimal assessment of the tumor matrix. MRI is specifically required to study the lesion effect on the spinal canal.

Bone Diseases↗
PubMed1997

Clinical trials in rheumatoid arthritis: methodological suggestions for assessing radiographs arising from the GRISAR Study. Gruppo Reumatologi Italiani Studio Artrite Reumatoide.

OBJECTIVES: The three x ray assessors of the GRISAR study (blinded to treatment) gave consensual erosion and damage scores to the baseline and 12 month radiographs of 284 rheumatoid arthritis (RA) patients using three different methods: single readings (blinded as to patient and chronological sequence of the x rays), paired readings (blinded as to sequence), and chronologically ordered paired readings. The aim was to evaluate which of these reading procedures is the most appropriate for clinical trials. METHODS: The progression of the scores obtained using each procedure was compared by means of descriptive statistics, principal components analysis, and intra-patient correlation coefficients of pairs of methods. Bootstrap estimates of the variance of the difference in the means of two equally sized random samples were calculated to evaluate the power of the statistical analysis performed to assess the possible treatment effect for both paired and chronological reading methods. RESULTS: (a) The standard deviations of the paired and chronological readings were similar, but that of the single readings was higher. (b) The knowledge that two x rays were of the same patient accounted for a sizeable proportion of the between method variability. (c) Agreement was satisfactory between the paired and chronological methods for both scores but, between them and the single readings, it was modest for erosions and poor for damage. (d) The bootstrap estimate of the variance of the difference was smaller for the paired than the chronological method, possibly giving it greater power to test treatment effect. CONCLUSIONS: These results suggested that paired readings were the most suitable for evaluating the progression of joint damage in the GRISAR study.

Arthritis, Rheumatoid↗