Inactivation of the genes involved in DNA mismatch repair is associated with microsatellite instability (MSI) in colorectal cancer. We report that hypermethylation of the 5′CpG island of hMLH1 is ...found in the majority of sporadic primary colorectal cancers with MSI, and that this methylation was often, but not invariably, associated with loss of hMLH1 protein expression. Such methylation also occurred, but was less common, in MSI- tumors, as well as in MSI+ tumors with known mutations of a mismatch repair gene (MMR). No hypermethylation of hMSH2 was found. Hypermethylation of colorectal cancer cell lines with MSI also was frequently observed, and in such cases, reversal of the methylation with 5-aza-2′-deoxycytidine not only resulted in reexpression of hMLH1 protein, but also in restoration of the MMR capacity in MMR-deficient cell lines. Our results suggest that microsatellite instability in sporadic colorectal cancer often results from epigenetic inactivation of hMLH1 in association with DNA methylation.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
For patients with primary hyperparathyroidism surgical removal of the hyperfunctioning parathyroid gland is curative. With advances in minimally invasive surgery, accurate pre-operative localization ...of the hyperfunctioning parathyroid tissue is essential to aid successful surgical treatment. The onus of identifying this hyperfunctioning parathyroid tissue therefore falls on imaging techniques such as high-resolution ultrasound, radionuclide imaging, computed tomography and magnetic resonance imaging. This article is not an exhaustive review, and its main aim is to familiarize the general radiologist, trainee radiologists and clinicians with the basics of various imaging techniques and their roles in practical management of patients with primary hyperparathyroidism.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The clinical significance of microbleeds (MBs) in the development of psychiatric conditions following a stroke is unknown. Lesions located in various cortical and subcortical areas are thought to be ...involved in the pathophysiology of post-stroke emotional lability (PSEL). This study examined the association between PSEL and MBs.
A total of 519 Chinese patients with acute ischaemic stroke consecutively admitted to the acute stroke unit of a university affiliated regional hospital in Hong Kong were screened for PSEL 3 months after their index stroke. The number and location of MBs were evaluated with MRI.
According to Kim's criteria, 74 (14.3%) patients had PSEL. In comparison with the non-PSEL group, patients in the PSEL group were more likely to have MBs in the thalamus as a whole (16.2% vs 6.5%; p = 0.004), its anterior (6.9% vs 2.0%, p = 0.02) and paramedian territories (8.1% vs 3.1%; p = 0.04), and a higher number of MBs in the entire brain (1.7+3.4 vs 1.3+5.0; p = 0.031). MBs in the thalamus remained an independent predictor of PSEL in the multivariate analysis, with an odds ratio of 4.7 (p = 0.002).
Our results suggest that MBs in the thalamus may play a role in the development of PSEL. The importance of MBs in PSEL and other psychiatric conditions in stroke survivors warrants further investigation.
Radiotherapy is used to treat a wide variety of head and neck tumours that arise in and around the skull base. The delayed effects of radiation damages a range of structures, including the nervous ...system, bone, major vessels, mucus membranes, pituitary and salivary glands, as well as increasing the risk of radiation-induced neoplasms. In this review the complications resulting from radiation treatment for nasopharyngeal carcinoma (NPC), a cancer treated with a high dose of radiation to a fairly large region, are illustrated. Many patients with NPC have a long-term survival, so are at risk of developing delayed radiation effects, and hence may demonstrate a wide range of complications on imaging. Other tumours around the skull base treated with radiotherapy include meningiomas, chordomas, chondrosarcomas, pituitary adenomas, paranasal sinus and nasal cavity tumours. In these cases similar complications may be encountered on imaging, although the severity, incidence and location will vary.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
► This is an automated novel algorithm for DTI stitching in human spinal cord. ► It has been tested on data from a normal subject and an AIS patient. ► It provides a full-view of the DTI spinal cord ...images.
Diffusion tensor imaging (DTI) has become an important tool for studying the spinal cord pathologies. To enable high resolution imaging for modern studies, the DTI technique utilizes a small field of view (FOV) to capture partial human spinal cords. However, normal aging and many other diseases which affect the entire spinal cord increase the desire of acquiring the continuous full-view of the spinal cord. To overcome this problem, this paper presents a novel pipeline for automatic stitching of three-dimensional (3D) DTI of different portions of the spinal cord. The proposed technique consists of two operations, e.g. feature-based registration and adaptive composition to stitch every source image together to create a panoramic image. In the feature-based registration process, feature points are detected from the apparent diffusion coefficient map, and then a novel feature descriptor is designed to characterize feature points directly from a tensor neighborhood. 3D affine transforms are achieved by determining the correspondence matching. In the adaptive composition process, an effective feathering approach is presented to compute the tensors in the overlap region by the Log-Euclidean metrics. We evaluate the algorithm on real datasets from one healthy subject and one adolescent idiopathic scoliosis (AIS) patient. The colored FA maps and fiber tracking results show the effectiveness and accuracy of the proposed stitching framework.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract Osteoporosis is associated with an increase in marrow fat. Fats, particularly polyunsaturated fats, either in co-cultures or diet, have been shown to significantly influence bone remodeling. ...Whether the increase in marrow fat seen in osteoporosis is also associated with a change in fatty acid composition is not known. This study was undertaken to investigate the fatty acid composition in subjects of varying bone mineral density (BMD). Samples of marrow fat and subcutaneous fat from 126 subjects (98 females, 34 males, mean age 69.7 ± 10.5 years) undergoing orthopedic surgery were analyzed for fatty acid composition by gas chromatography. These results were correlated with BMD assessed by DXA. A total of 22 fatty acids were identified in marrow and subcutaneous fat. Significant differences in fatty acid composition existed between marrow and subcutaneous fat as well as between marrow fat samples obtained from the proximal femur and proximal tibia. Other than cis-7-hexadecenoic acid C16:1 ( n = 9) and docosanoic acid C22:0, no difference in marrow fatty acid composition was evident between subject groups of varying BMD (normal, low bone mass, and osteoporosis). In conclusion, there exists a wide range of individual fatty acids in marrow fat. Marrow fatty acid composition differs from that of subcutaneous fat and varies between predominantly erythropoetic and fatty marrow sites. Other than cis-7-hexadecenoic acid C16:1 ( n = 9) and docosanoic acid C22:0, no difference in marrow fatty acid composition was evident between subjects of varying BMD.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Vestibular schwannomas are not uncommon, and gamma knife radiosurgery
is one of the treatment options for symptomatic tumors. Hydrocephalus
is a complication of gamma knife treatment of vestibular ...schwannoma,
though the mechanism of the development of hydrocephalus remains
controversial. We present an unusual case of normal pressure
hydrocephalus (NPH) after gamma knife radiosurgery of a vestibular
schwannoma in which the timeline of events strongly suggests that gamma
knife played a contributory role in the development of the
hydrocephalus. This is probably the first case of NPH post radiosurgery
with normal cerebrospinal fluid protein. Communicating hydrocephalus
should be treated with placement of shunt while non-communicating
hydrocephalus can be treated with third ventriculostomy. Frequent
monitoring and early intervention post radiosurgery is highly
recommended to prevent irreversible cerebral damage.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Although transcutaneous ultrasound combined with fine-needle aspiration is often used as initial modality for evaluating superficial neck masses, its role in management of deep-seated neck masses is ...limited. Intraoral ultrasound and guided biopsy helps in obtaining tissue from deep-seated neck masses for an accurate histologic diagnosis, providing useful information in treatment planning. This article discusses the role of intraoral ultrasound and presents 3 cases in which biopsy of deep-seated neck masses under intraoral ultrasound guidance helped in diagnosis and management.
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