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Biomedical subjects

S E Powell

Publications and source records attributed to S E Powell.

15 recordsLinked to original sources
PubMed2006

Microscopic polyarteritis presenting with skin necrosis in a patient with sickle-cell disease.

A 20-year-old Caribbean woman with sickle cell anaemia was admitted with a 4-day history of fever and a painful swollen right ankle. She rapidly developed skin necrosis. The differential diagnosis is discussed. This case illustrates the difficulty in identifying the cause of cutaneous necrosis in an acutely ill patient. In our patient, histopathology implicated a vasculitic process, which was subsequently identified as a manifestation of microscopic polyarteritis.

Adult↗
PubMed2000

Regulation of insulin-like growth factor-binding protein-3 ternary complex in feline diabetes mellitus.

The 140 kDa ternary complex of insulin-like growth factor-binding protein-3 (IGFBP-3), IGFs and an acid-labile subunit (ALS) has previously been shown to be decreased in diabetes mellitus in humans and rats. We have studied IGF-I levels and ternary complex formation in normal and diabetic cats. Total IGF-I concentrations, measured by RIA using des(1-3)-IGF-I as tracer were (+/-s.e.m.) 54+/-13 nmol/l in eight normal and 227+/-57 nmol/l in eight diabetic cats (P<0.01). The size-distribution of IGFBPs in the cat circulation was determined by incubation with (125)I-IGF-II and Superose 12 chromatography. In normal animals 26+/-2% of the (125)I-IGF-II were in a 140 kDa form compared with 48+/-5% in diabetic cats (P<0.01). When samples from normal and diabetic animals were co-incubated 52+/-3% were at 140 kDa. A similar shift was seen when normal cat and normal human serum were co-incubated. A 2-fold increase in the 140 kDa form in diabetic cats was confirmed first by size-fractionating samples and then performing a ligand-binding assay with (125)I-IGF-I or -II and charcoal separation. SDS-PAGE and Western ligand blotting demonstrated a 45 kDa doublet (presumably IGFBP-3) and 30-35 kDa forms. There were no apparent differences between normal and diabetic profiles on SDS-PAGE, suggesting that a proportion of IGFBP-3 which circulates 'free' in normal cats forms a ternary complex in the diabetic circulation. We conclude that (i) in contrast to humans and rats, ALS is the limiting factor for ternary complex formation in normal cats, (ii) ALS concentrations increase in feline diabetes mellitus and, by promoting ternary complex formation, this leads to an increase in total IGF-I concentrations, and (iii) total IGF-I concentrations may not be reliable in the diagnosis of acromegaly in diabetic cats.

Acromegaly↗
PubMed1995

Ten-year in vitro assessment of the surface status of three retrofilling materials.

Sixty-one maxillary central incisors were collected, cleaned, and divided into six groups of 10 teeth, with one tooth as a control. Half of the teeth were resected with a high-speed bur and half with a slow-speed bur, and prepared for retrofillings. Retrofillings of EBA cement and Ketac cement were placed in 10 teeth, each of the high-speed and slow-speed groups. Similarly++, zinc containing amalgam was placed in 10 teeth of the high-speed group, and zinc-free amalgam was placed in 10 teeth in the slow-speed group. A single operator completed all retrofills. They were stored in physiological saline for 10 yr. After that period, the apical portions were photographed at X 30 magnification and evaluated by the authors for marginal discrepancies, root crazing, staining, voids, and roughness. Overall, EBA cement++ and amalgam rated better than Ketac cement in every category except root crazing. Perhaps, as some studies have suggested, EBA cement may replace amalgam as the retrofill material of choice.

Aluminum Oxide↗
PubMed1990

Endodontics: errors in instrumentation.

The authors provide a pictorial review of technical errors in endodontic instrumentation. Examples of separated instruments, abrupt constriction, laceration, canal transportation, and control zone errors are provided. The potential problems and effect on prognosis associated with these errors are explained.

Dental Instruments↗
PubMed1989

Spontaneous apical closure of an avulsed immature incisor.

Apical closure of nonvital teeth can be achieved by appropriate endodontic intervention. A case is reported in which apical maturation appears to have occurred without treatment and in the presence of sporadic drainage from a sinus tract stoma.

Child↗
PubMed1986

Recurrent knee pyarthrosis with intact hyaline cartilage. A case report.

A 20-year-old patient with hyperimmunoglobulin E and abnormal leukocyte chemotaxis was treated by synovectomy for chronic and recurrent staphylococcal knee pyarthrosis. The articular cartilage was noted to be preserved despite the severity of synovial involvement and the chronic nature of this case of septic arthritis. Polymorphonuclear leukocytes were few, despite florid Staphylococcus aureus growth. This observation lends support to the role of lysozomal enzyme activity from leukocytes in hyaline cartilage damage in pyarthrosis.

Adult↗