Search PubMed⌕ Search

Biomedical subjects

S Rees

Publications and source records attributed to S Rees.

152 records · Page 9Linked to original sources
PubMedDate not supplied

A retrospective review of the weil metatarsal osteotomy for lesser metatarsal deformities: an intermediate follow-up analysis.

The purpose of this retrospective clinical study was to determine the clinical results of the Weil metatarsal osteotomy. There were 51 patients (89 procedures), consisting of 10 males and 41 females, with a mean 53.1 +/- 11.9 years. Patients were evaluated for subjective improvement on a scale from 0 to 10, and asked if they would repeat the procedure. They were evaluated functionally using the American Orthopedic Foot and Ankle Society's lesser metatarsal rating scale, and assessed for toe purchase and range of motion. Thirty-nine point two percent of patients reported a complete resolution of pain (10/10 points), with 13.7% reporting a score of < or = 5/10. Eighty percent of the patients would repeat the procedure. The most common complication was toe elevation in 33% of patients. Joint range of motion was reduced in most cases. Thirty five patients experienced no pain at end range of motion, 6 related significant pain and 9 patients experienced some pain. Patients who underwent the procedure as a prophylactic measure along with a first ray procedure formed a significant subgroup (31%). These patients also scored well in comparison to the remainder of patients, with a mean subjective score of 8.4/10 as compared with 7.9/10 for the remainder of patients. The prophylactic group also demonstrated a median functional rating scale score of 90, versus 80 for the remainder of patients. These findings suggest that the Weil metatarsal osteotomy is a useful procedure for metatarsalgia and may also be useful in preventing lesser metatarsalgia in conjunction with first metatarsal surgery.

Adolescent↗
PubMedDate not supplied

Diagnosis of femoral arteriovenous fistula by MR imaging with velocity mapping.

A case of suspected femoral arteriovenous fistula after cardiac catherization remained undiagnosed because of inability to obtain access for arteriography. Magnetic resonance imaging with phase-shift velocity mapping allowed a noninvasive diagnosis and qualitative evaluation of the lesion.

Arteriovenous Fistula↗
PubMedDate not supplied

Cardiac flow measurement by ultrafast CT: validation of continuous and pulsatile flow.

To gauge the accuracy of ultrafast CT in measuring cardiac output and myocardial perfusion in humans, measurements of continuous and pulsatile flow were made in a large asymmetrical phantom. The variation in the relationship between Hounsfield number and contrast concentration was assessed in a human thorax phantom. Radiopaque contrast medium was injected during perfusion of the phantom at a range of flow rates between 1.5 and 8 L/min. The phantom was scanned in two modes (50 and 100 ms) during continuous and pulsatile flow and with the phantom surrounded by air and by water. Flow in the tubes was calculated using indicator dilution theory, and flow in the tissue-equivalent chamber was calculated by applying first-pass distribution principles. The standard deviation of the difference between calculated and measured flow varied from 0.2 to 0.6 L/min, giving 95% limits of agreement from 0.4 to 1.2 L/min. The constant (K) relating Hounsfield unit number to iodine concentration varied widely both in different locations within the phantom and under different scan conditions (17.2-27.6 HU/mg I). Within a human thorax phantom, K varied from 14.15 to 23.18 HU/mg I and was dependent on location within the thorax phantom, the scan mode, and the cross-sectional diameter of the phantom. These data suggest that though the ultrafast CT scanner can measure continuous and pulsatile flow accurately in tubes, precise measurements of cardiac output in humans will require K to be assessed for each subject. Measurements of flow in tissue should be possible.

Cardiac Output↗
PubMedDate not supplied

Development of a dual glow-signal firefly and Renilla luciferase assay reagent for the analysis of G-protein coupled receptor signalling.

Several reporter gene assays have been described where gene transcription is activated as a consequence of a specific signal transduction event, such as activation of adenylyl cyclase (1.2). Reporter genes typically consist of specific responsive elements placed upstream of a minimal promoter, which together control the expression of a readily detectable reporter protein, such as luciferase. We have developed a dual glow-signal firefly and Renilla luciferase assay, which allows the simultaneous measurement of two reporter genes in the same well of a 96-well plate. In this report we demonstrate the use of this assay for the simultaneous analysis of agonist activity at two G-protein coupled receptors which signal through activation of the G-protein alpha sub-unit, G alpha S. Chinese hamster ovary (CHO) cells stably transfected with a cAMP responsive firefly luciferase reporter were further transfected with the human Vasopressin V2 receptor. Similarly, CHO cells stably transfected with a cAMP responsive Renilla luciferase reporter were further transfected with the human beta 2-adrenoceptor. The two cell lines were mixed in individual wells of a 96-well plate and a number of compounds were screened to determine their activity at both receptors. Stimulation with vasopressin and beta 2-adrenoceptor agonists resulted in the activation of the firefly and Renilla luciferases respectively. Stimulation with forskolin, which directly stimulates adenylyl cyclase, caused the activation of both reporter genes, and stimulation with a range of further compounds with no activity at either receptor did not generate a reporter response. The dual luciferase assay allows the simultaneous screening of two receptors in a 96-well format resulting in significant time and cost savings.

Animals↗