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A D King

Publications and source records attributed to A D King.

At least 19 recordsLinked to original sources
PubMed2005

Imaging for thyroglossal duct cyst: the bare essentials.

Thyroglossal duct cyst is the most common congenital cyst in the head and neck, and imaging features have been well documented in the literature. However, there are several practical important points to bear in mind during preoperative imaging, which are often overlooked. This review aims to summarize the imaging findings and emphasize important points for trainees and radiologists, particularly those who may encounter this lesion infrequently.

Adult↗
PubMed2005

Human cervical lymphadenopathy: evaluation with in vivo 1H-MRS at 1.5 T.

AIM: To evaluate the feasibility of performing in vivo proton magnetic resonance spectroscopy ((1)H-MRS) of cervical lymph nodes, and the clinical usefulness of the technique in the characterization of cervical lymphadenopathy. MATERIALS AND METHODS: Cervical lymphadenopathy was examined in 20 individuals with malignant disease, i.e. 10 with squamous cell carcinoma (SCC), 6 with undifferentiated carcinoma (UDC) and 4 with non-Hodgkin's lymphoma (NHL). Cervical lymphadenopathy was also examined in 4 individuals with benign disease, i.e. 3 with tuberculosis (TB) and 1 with Castleman's disease. A point-resolved spectroscopic sequence with echo times (TE) of 136 and 272 ms and a time-domain spectral fitting procedure were used to estimate peak amplitude of choline (Cho), creatine (Cr) and unsuppressed water. Cho/Cr and Cho/water ratios were measured for each lesion. The mean ratio for each lesion group was obtained and results were compared statistically. RESULTS: At TE of 136 ms, spectra were interpretable in all 24 cases and a Cr peak was identified with post-processing in 15 cases. The Cho/Cr and Cho/water ratios for NHL were 9.1 +/- 5.2 and 1.7 +/- 0.2 x 10(-3), for UDC were 4.4 +/- 0.9 and 1.2 +/- 0.4 x 10(-3), and for SCC were 2.1 +/- 0.6 and 0.5 +/- 0.3 x 10(-3), respectively. Both Cho/Cr and Cho/water ratios for UDC were significantly higher than SCC (p = 0.002 and 0.026, respectively). At TE of 272 ms, spectra were interpretable in 22 of 24 cases and a Cr peak was identified with post-processing in 11 cases. Cho/Cr and Cho/water ratios for NHL were 5.4 and 4.6 +/- 1.4 x 10(-3), for UDC were 4.2 +/- 1.5 and 2.6 +/- 1.0 x 10(-3) and for SCC were 2.5 +/- 1.1 and 1.3 +/- 0.6 x 10(-3), respectively. The Cho/water ratio for UDC was significantly higher than for SCC (p = 0.04). The Cho/Cr ratio for UDC was also higher than for SCC, but this difference was not statistically significant (p = 0.07). Neither Cho nor Cr was detected in the 3 cases of TB. CONCLUSION: In vivo (1)H-MRS is a feasible technique for the evaluation of cervical lymph nodes and it offers potential as a clinical tool in the investigation of cervical lymphadenopathy. However, further studies with larger patient cohorts are needed to validate the findings of this initial report.

Adult↗
PubMed2004

Protein complex prediction via cost-based clustering.

MOTIVATION: Understanding principles of cellular organization and function can be enhanced if we detect known and predict still undiscovered protein complexes within the cell's protein-protein interaction (PPI) network. Such predictions may be used as an inexpensive tool to direct biological experiments. The increasing amount of available PPI data necessitates an accurate and scalable approach to protein complex identification. RESULTS: We have developed the Restricted Neighborhood Search Clustering Algorithm (RNSC) to efficiently partition networks into clusters using a cost function. We applied this cost-based clustering algorithm to PPI networks of Saccharomyces cerevisiae, Drosophila melanogaster and Caenorhabditis elegans to identify and predict protein complexes. We have determined functional and graph-theoretic properties of true protein complexes from the MIPS database. Based on these properties, we defined filters to distinguish between identified network clusters and true protein complexes. CONCLUSIONS: Our application of the cost-based clustering algorithm provides an accurate and scalable method of detecting and predicting protein complexes within a PPI network.

Algorithms↗
PubMed2004

The solubility of ethane, propane, and carbon dioxide in aqueous solutions of sodium cumene sulfonate.

Measurements have been made to determine the solubilities of ethane, C2H6, propane, C3H8, and carbon dioxide, CO2, in aqueous solutions of sodium cumene sulfonate (NaCS) at 25 degrees C. The solubilities measured for each gas satisfy Henry's law at all concentrations of NaCS. The solubilities of C2H6 and C3H8 exhibit quite similar behavior with respect to added NaCS. The solubilities of these two gases are very low in pure water and are found to be nearly independent of NaCS concentration over a concentration range of 0-0.4 mol NaCS/kg H2O. At intermediate concentrations of NaCS, the solubilities of C2H6 and C3H8 exhibit a gradual increase with added NaCS concentrations ranging from 0.4 to 2.0 mol NaCS/kg H2O. At NaCS concentrations greater than 2.0 mol NaCS/kg H2O, the solubilities of these two gases increase with added NaCS in an approximately linear manner, with the solubility of C3H8 increasing more rapidly than that for C2H6 (by a factor of approximately 2.5). CO2 is much more soluble in pure water than the hydrocarbon gases and exhibits markedly different behavior with respect to added NaCS. The solubility of CO2 decreases with added NaCS over a concentration range of 0-0.9 mol NaCS/kg H2O, passes through a minimum at a concentration of approximately 1.0 mol NaCS/kg H2O, and then increases with added NaCS at higher NaCS concentrations in a manner similar to that observed with C2H6 and C3H8. The trends in solubility observed for these three gases dissolved in aqueous solutions of NaCS resemble those found previously with aqueous solutions of ordinary surfactants. The solubility data measured for these three gases can be interpreted surprisingly well in terms of the mass-action model for micellization, in which salting-out effects due to monomer salt ions suppress gas solubility at low NaCS concentrations and gas solubilization by small micelles of NaCS acts to enhance gas solubility at the higher NaCS concentrations.

Benzene Derivatives↗
PubMed2004

Imaging for primary hyperparathyroidism--what beginners should know.

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.

Diagnostic Imaging↗
PubMed2004

Vascular lesions of parotid gland in adult patients: diagnosis with high-resolution ultrasound and MRI.

Three adult patients with rare vascular lesions in the parotid gland including pseudoaneurysm, arteriovenous fistula and haemangioma are discussed. All patients presented with non-specific unilateral parotid mass. In all cases high-resolution ultrasound and MRI allowed accurate diagnosis and delineation of the extent of lesion. Conventional angiogram was utilized for planning definitive surgical or endovascular treatment.

Adult↗
PubMed2004

MRI of neck nodes in non-Hodgkin's lymphoma of the head and neck.

The aim of this study is to describe the imaging features of neck nodes in non-Hodgkin's lymphoma (NHL). The MR scans of 61 patients undergoing staging of a primary extranodal NHL of the head and neck were reviewed retrospectively. Those MR images with nodal disease were assessed for (a) the pattern of nodal disease, (b) presence of nodal necrosis and (c) presence of extracapsular neoplastic spread (ENS) and nodal matting. The features of the nodal disease were analysed in relationship to the sites of the primary NHL (palatine tonsil (PT) n=23, nasal cavity (NC) n=24, nasopharynx (NP) n=6, other extralymphatic sites (OES) n=8), and histology (natural killer/T-cell (NK/T) n=26, diffuse large cell (DLC) n=24, other subtypes (OS) n=11). Nodal disease was present in 26 patients (43%) and occurred in NHL of the PT n=16 (70%), NP n=3 (50%), NC n=5 (21%) and OES n=2 (25%) and in DLC n=15 (63%), NK/T n=6 (23%) and OS n=5 (45%). Nodal disease was significantly more frequent in DLC than NK/T lymphomas (p=0.0053). Nodal disease spread in a contiguous fashion in 25 (96%) patients with nodes. Necrosis was present in 7 of 26 (27%) being present in DLC of the PT in 5, NK/T of the NP in one and NK/T of the NC in one. ENS and matting were present in 19 (73%) and 13 (50%) patients with nodes, respectively. ENS was found in DLC, NK/T, OS, NC, NP, PT, OES (11, 4, 4,1, 2, 14, 2, respectively) and matting was found in DLC, NK/T, OS, NC, NP, PT, OES (9, 3, 1, 0, 2, 10, 1, respectively). Nodal NHL spreads in a contiguous fashion and is most commonly associated with DLC lymphoma of the NP and PT in Waldeyer's ring. Extracapsular nodal spread is frequent and found in most histological subtypes especially those arising from Waldeyer's ring. Necrosis is more common than previously believed.

Adolescent↗
PubMed2004

Clinics in diagnostic imaging (101): Multinodular accessory thyroid tissue.

A 71-year-old woman with a strong family history of thyroid cancer presented with 3 months of constipation. A carcinoid tumour of the rectum was found at colonoscopy. On physical examination, she had a large goitre and there was a 3-4 cm firm submental mass. The differential diagnosis was accessory thyroid tissue or a carcinoma metastasis. Staging computed tomography was performed to include the neck, followed by ultrasonography and aspiration biopsy of the submental mass, which confirmed the diagnosis of multinodular accessory thyroid tissue. Differences in aetiology and pathophysiology of accessory thyroid tissue and ectopic thyroid glands are discussed.

Aged↗
PubMed2003

Non-Hodgkin's lymphoma of the nasopharynx: CT and MR imaging.

OBJECTIVE: Nasopharyngeal (NP) non-Hodgkin's lymphoma (NHL) is an uncommon tumour. The aim of the study was to describe the appearances on CT and MR imaging, and identify the features which help to distinguish NPNHL from other NP tumours. MATERIALS AND METHODS: The CT (n=8) and MR (n=10) images of 14 patients with NPNHL were reviewed retrospectively. Patients with NPNHL were divided into primary NPNHL, where the primary tumour was in the NP (n=7) and secondary NPNHL where the primary tumour was at another extranodal site in the head and neck (n=7). All NPNHL were assessed for tumour size and distribution, appearance and local tumour invasion, in addition lymphadenopathy was assessed in primary NPNHL. RESULTS: The NPNHL ranged in size from 20-75 mm (mean of 55 mm for primary and 30 mm for secondary NHL) and were homogeneous on CT in eight (100%) and MR in seven (70%) and mildly heterogeneous on MR in three (30%) patients. NPNHL involved all walls of the NP in 10 (71%) (n=1). Primary NPNHL extended superficially in five (71%) to involve the nasal cavity (n=3) and oropharynx (n=2) and lymphadenopathy was present in five (71%) being bilateral and involving multiple nodal sites (n=4) with necrosis (n=2) and matting (n=3). CONCLUSION: NPNHL is a homogeneous tumour that tends to diffusely involve all walls of the nasopharynx and spread in an exophytic fashion to fill the airway, rather than infiltrating into the deep tissues. Deep tumour infiltration, when it occurs, is found in those patients with primary NHL and is usually limited in extent and of small volume. and extended in an exophytic fashion to fill the NP cavity in six (43%). Deep tumour invasion was present in two (14%) both patients with primary NHL, the extent and volume of this tumour invasion was small and involved the prevertebral muscles (n=2), parapharyngeal fat space (n=1) and skull base Primary NHL more commonly spreads superficially to involve the nasal cavity or oropharynx, lymphadenopathy is frequent and extensive. A large tumour that fills the nasopharynx, with no or minimal invasion into deep structures, and a propensity to extend down into the tonsil, rather than up into the skull base, may suggest the diagnosis of NHL over nasopharyngeal carcinoma.

Adult↗
PubMed2003

Accuracy of high-resolution sonography compared with magnetic resonance imaging in the diagnosis of head and neck venous vascular malformations.

AIMS: To evaluate whether modern ultrasound examination helps to establish the diagnosis of head and neck venous vascular malformations (VVMs) and whether it can delineate their full extent. MATERIALS AND METHODS: Sonographic appearances of 30 head and neck VVMs were assessed for: location, extent, internal architecture, presence of flow and phleboliths. These results were compared with the magnetic resonance imaging (MRI) of the same patients. RESULTS: The lesions showed well-defined margins (22 of 30, 73%), heterogeneous (30 of 30, 100%) and hypoechoic echo pattern (27 of 30, 90%), with sinusoidal spaces (28 of 30, 93%) and phleboliths (24 of 30, 80%) on grey-scale imaging, and flow signal on Doppler (28 of 30, 93%). For delineating the extent, ultrasound was comparable with MRI in 53% (16 of 30) and inferior to MRI in 47% (14 of 30). Ultrasound did not detect deeper extent, intra-osseous involvement and other clinically occult VVMs. CONCLUSION: Ultrasound with high-resolution transducers can confidently suggest the diagnosis of head and neck VVMs in up to 90% of cases, and delineate the full extent of some superficial lesions. The major disadvantage is its inability to evaluate intra-osseous involvement and the entire extent of large, deep-seated lesions.

Adolescent↗
PubMed2003

Kuttner tumour (chronic sclerosing sialadenitis) of the submandibular gland: sonographic appearances.

Patients with Kuttner tumours present with clinical features simulating a submandibular tumour. This article aims to familiarise sonologists with the sonographic appearances of these tumours, to help in their differentiation from other salivary lesions. In 13 patients with histologically or cytologically proven Kuttner tumours, the features evaluated on sonography included: shape and border of the gland, internal architecture, duct dilatation, presence/absence of calculi and presence and distribution of vascularity. There was diffuse involvement of the submandibular glands in 11 patients and focal involvement in 2. The majority (9 of 11) of the patients with diffuse involvement showed sonographic appearances simulating a "cirrhotic" liver; 2 showed diffuse heterogeneous involvement with duct dilatation and calculus. Doppler showed prominent intraglandular vessels, with no evidence of displacement. Focal lesions (2 of 11) were seen as hypoechoic, heterogeneous "masses," with a radial branching vascular pattern within, on Doppler. In conclusion, sonographic features may help in identifying Kuttner tumours of the submandibular glands.

Adult↗
PubMed2001

Fibromatosis of the head and neck region.

OBJECTIVE: Five cases of head and neck fibromatosis were analyzed. The imaging and pathologic findings, surgical management, and clinical outcome were discussed. STUDY DESIGN AND SETTING: A retrospective study of 5 adult head and neck fibromatosis cases, evaluating long-term follow-up results of conservative treatment. RESULTS: The 5 patients (2 male and 3 female) ranged in age from 16 to 51 years. The lesion size ranged from 1 to 8 cm. Four cases had limited surgical resection; 1 case was followed only. One of the surgically treated cases had a recurrence that was irradiated. All patients were well for a follow-up period of 2 to 8 years. CONCLUSION: Aggressive excision of head and neck fibromatosis cannot be achieved easily. Vigilant follow-up with or without conservative surgical excision achieves good disease control. Low dose radiotherapy can be used for inoperable cases. SIGNIFICANCE: Judicious conservative treatment should be attempted for head and neck fibromatosis to achieve optimal functional preservation.

Adolescent↗
PubMed2001

MRI of primary non-Hodgkin's lymphoma of the palatine tonsil.

Non-Hodgkin's lymphoma (NHL) arising primarily in the palatine tonsil is uncommon. The aims of the study were to describe the appearances on MRI and to identify the features that help to distinguish NHL from other tonsillar tumours. The clinical records and MR images of eight patients with primary NHL of the palatine tonsil were reviewed. Patients had a short duration of symptoms (mean 1 month). Systemic symptoms (fever, weight loss or night sweats) occurred in two patients. Tumours were round or lobulated and ranged in size from 30 mm to 70 mm. The signal intensity on T2 weighted, T1 weighted and T1 weighted contrast enhanced images was homogeneous and similar to that of normal tonsil in six patients. Two large tumours were mildly heterogeneous and one of these showed small foci of necrosis. NHL of the tonsil displaced rather than invaded local structures in seven patients and locally invaded the soft palate in only one patient. Lymphadenopathy was present in five patients and the nodes were of similar signal intensity to the primary tumour. There was involvement of the ipsilateral upper internal jugular chain in all cases of lymphadenopathy. The posterior triangle was involved in two patients, the periparotid node in one patient and the retro-oropharyngeal region in one patient. The presence of a large tumour without deep invasion together with homogeneous non-necrotic nodes suggests the diagnosis of NHL. As NHL frequently has similar signal intensity to normal tonsil, MRI may not be able to detect lymphomatous involvement in the non-enlarged tonsil.

Adult↗
PubMed2000

Purified dengue 2 virus envelope glycoprotein aggregates produced by baculovirus are immunogenic in mice.

The full-length dengue 2 virus envelope glycoprotein (Egp) was expressed in insect cells by recombinant (r) baculovirus and found to form multimeric aggregates that were recovered in the void volume of gel filtration columns and by ultracentrifugation. An immunoblot confirmed that rEgp aggregrates disrupted with SDS sample buffer released a monomeric form that migrated with a molecular weight similar to native dengue 2 virus Egp on polyacrylamide gels. The rEgp aggregates reacted strongly with a panel of monoclonal antibodies specific for the native Egp and which identify critical structural and functional epitopes. The rEgp aggregates were purified by ultracentrifugation through 30% sucrose, and were shown to be the major protein band on a polyacrylamide gel and corresponding immunoblot. Purified rEgp aggregates in combination with aluminum hydroxide induced high titer neutralizing antibodies in adult mice. The generation of full-length dengue 2 rEgp aggregates in insect cells facilitated development of a simple, effective procedure for purification of the recombinant protein, and represents a good approach for producing highly immunogenic dengue 2 rEgp as a component of a subunit vaccine.

Adjuvants, Immunologic↗
PubMed2000

Neck node metastases from nasopharyngeal carcinoma: MR imaging of patterns of disease.

BACKGROUND: The purpose was to use MR imaging to document the patterns of nodal involvement in the upper neck in nasopharyngeal carcinoma (NPC). METHODS: The MR images of 150 patients with newly diagnosed NPC were reviewed retrospectively. Nodes were considered abnormal on MR criteria of size, necrosis, and extracapsular spread. RESULTS: Retropharyngeal nodes (RN) were more frequently involved than nonretropharyngeal nodes (NRNs) (94% vs 76% in 115 patients with nodal metastases). NRN involvement without RN was seen in only 7 of 115 patients (6%). Involvement of RN at the level of the oropharynx (82%) was as common as at the nasopharynx (83%) level. Internal jugular nodes were the most frequently involved NRN nodes (72%). Spinal accessory nodal involvement was also common (57%) but seldom in isolation (8%). Submandibular (3%) and parotid (2%) nodal metastases were uncommon and were always associated with advanced nodal metastases in the ipsilateral RN, internal jugular, and spinal accessory regions. CONCLUSION: Retropharyngeal nodes are the first echelons of nodal metastases. Direct lymphatic spread to the neck without involvement of the RN nodes is uncommon. RN metastases at the level of the oropharynx are more common than previously suspected, and this should influence radiotherapy planning. NRN outside the internal jugular and spinal accessory chains are rare and only occur when the usual routes of lymphatic spread have already been blocked by tumor.

Adult↗
PubMed2000

Paranasopharyngeal space involvement in nasopharyngeal cancer: detection by CT and MRI.

Paranasopharyngeal tumour extension (PTE) from nasopharyngeal carcinoma (NPC) is staged in its own subgroup in the American Joint Committee on Cancer classification. Most large clinical trials use computed tomography (CT) to stage PTE, but diagnosis relies on indirect signs of tumour invasion such as asymmetry of the parapharyngeal fat. Magnetic resonance imaging (MRI) has the advantage of directly revealing PTE because of its ability to depict the complex anatomical structures that form the boundary of the nasopharynx. The aim of this study was to compare CT and MRI in the identification of PTE and to determine whether the imaging modality used influenced staging of the disease. The MRI and CT scans of 78 patients (156 parapharyngeal regions) with NPC were assessed for PTE. On MRI, PTE was considered to be positive when there was tumour invasion through the complex anatomical structures of the nasopharyngeal wall. When using CT, it was considered positive when there was: (1) distortion of the parapharyngeal fat plane; or (2) extension beyond a line drawn from the medial pterygoid plate to the lateral aspect of the carotid artery. CT scanning and MRI were compared. PTE was judged to be present in 28 of 78 (36%) patients by MRI and in 41 of 78 (53%) scanning by CT when using criterion 1 or 2. An analysis of the discordant findings revealed that MRI was positive in three sides of the nasopharynx in early tumour extension through the pharyngobasilar fascia but not identified with CT by using criterion 1 or 2. MRI was negative in 20 and 21 sides of the nasopharynx that were judged to be positive on CT by using criterion 1 and 2 respectively. In these patients MRI revealed that the positive CT scan was caused by a large tumour compressing but not invading the parapharyngeal fat space, a metastatic lateral retropharyngeal node, or a combination of the two. The imaging modality used for staging NPC has an impact on the staging of PTE. CT scanning suggested the presence of PTE more frequently than MRI because of its inability to distinguish the primary tumour from lateral retropharyngeal nodes, and direct tumour invasion of the parapharyngeal region from tumour compression. The imaging modality and criteria used for staging PTE should be taken into consideration when assessing the results of clinical studies.

Adult↗