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E Philipps

Publications and source records attributed to E Philipps.

13 recordsLinked to original sources

Assembly of N-methyl-D-aspartate (NMDA) receptors.

The N-methyl-D-aspartate receptor (NMDAR) requires both NR1 and NR2 subunits to form a functional ion channel. Despite the recent advances in our understanding of the contributions of these different subunits to both the function and pharmacology of the NMDAR, the precise subunit stoichiometry of the receptor and the regions of the subunits governing subunit interactions remain unclear. Since NR2 subunits are not transported to the cell surface unless they associate with NR1 subunits, cell-surface expression of NR2A can be used to monitor the association of the different subunits in cells transfected with N- and C-terminally truncated NR1 subunits. By combining measurements of cell-surface expression of NR2A with co-immunoprecipitation experiments, and by using Blue Native gel electrophoresis to determine the oligomerization status of the subunits, we have shown that regions of the N-terminus of NR1 are critical for subunit association, whereas the truncation of the C-terminus of NR1 before the last transmembrane region has no effect on the association of the subunits. Evidence from the Blue Native gels, sucrose-gradient centrifugation and size exclusion of soluble NR1 domains suggests that NR1 subunits alone can form stable dimers. Using a cell line, which can be induced to express the NMDAR following exposure to dexamethasone, we have shown that NMDARs can be expressed at the cell surface within 5 h of the recombinant gene induction, and that there appears to be a delay between the first appearance of the subunits and their stable association.

Animals↗

Leukemic intestinal pneumatosis.

A benign form of pneumatosis intestinalis has been reported in children with leukemia but also occurs in adults as we report here. Radiologists must be familiar with this entity or a mistaken diagnosis of an abdominal catastrophe will be made, committing the patient to unneccessary emergency surgery.

Adolescent↗

Chronic erosive gastritis--a recently recognized disorder.

We have reviewed the clinical manifestations, endoscopic findings, pathology, and upper gastrointestinal x-rays in 10 patients with chronic erosive gastritis, a disorder that was rarely recognized before the use of double-contrast upper gastrointestinal radiology and endoscopy. The characteristic x-ray appearance is that of a series of 3 to 11-mm nodules, some with central collections of barium, that are distributed along rugal folds and usually extend into the antrum. The endoscopic appearance is similar: small erythematous nodules with shallow central erosions. The pathology differs from that seen in peptic ulcer disease. There are few polymorphonuclear leukocytes and a predominance of plasma cells in the inflammatory infiltrate. Seven of our patients presented with epigastric pain similar to that of peptic ulcer disease; four of these also had anorexia and weight loss. In two other patients anorexia and weight loss were the only symptoms. One patient was asymptomatic. All nine symptomatic patients responded to antacid treatment. However, repeat x-rays demonstrated persistence of the nodules, although the central erosions usually disappeared. The etiology is unknown. Chronic erosive gastritis appears to be a distinct entity different from peptic ulcer disease.

Adult↗

Chronic erosive gastritis resulting in cachexia.

Nine patients are reported who presented with severe weight loss of up to 13.6 kg (30 lb) as a result of chronic erosive gastritis. In many the cachexia was sufficient to prompt a search for malignancy but no other lesion was found. The importance of the radiological pursuit of this diagnosis is emphasised. Illustrative case histories are presented.

Adult↗

Chronic erosive gastritis--clinical and radiological features.

Chronic erosive gastritis has been regarded as an unusual, ill-defined condition of unknown etiology. We report a retrospective study of 40 patients in whom this diagnosis was made relating radiologic findings to patients' age, symptomatology and possible etiologic factors. The condition is more common than previously suspected and requires careful technique combining double contrast and graded compression to demonstrate fine mucosal abnormalities. The radiologic appearance is of mucosal mounds measuring 3-11 mm in diameter with central barium collections and numbering from 3-27 per examination. Antral involvement occurred in 90% of patients, with diffuse involvement of both antrum and body in 58%. Several linear erosions measuring up to 15 mm in length were also demonstrated. Chronic erosive gastritis is most severe and symptomatic between 40 and 60 years, becoming sub-clinical in the elderly. Symptoms mimic those of a peptic ulcer or gastric neoplasm and are more severe the more extensive the disease. Gastric irritants, virus infection and Crohn's disease were possible etiologic factors in some patients in this study.

Adult↗

Roentgen diagnosis of linear ulcers.

Linear peptic ulcerations are not uncommon lesions of the stomach and duodenum and can be demonstrated by upper gastrointestinal series. This is facilitated by the double contrast technique, but they may also be appreciated via compression methods. The criteria found helpful to establish the presence of a linear ulcer include: (a) contour deformity; (b) niche projection; (c) fuzzy line; and (d) folds radiating to a line (crater). Routine use of these criteria with the double-contrast method enabled the authors to diagnose 42 linear ulcers.

Duodenal Ulcer↗