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Biomedical subjects

G A Murrell

Publications and source records attributed to G A Murrell.

70 records · Page 4Linked to original sources
PubMed1988

Video-assisted prosthodontics.

An 8 mm camcorder was used to produce and replay video tape recordings of patient consultations, diagnosis, and treatment. The benefits of this modality were presented and discussed.

Consumer Behavior↗
PubMed1988

Esthetics and the edentulous patient.

Most individuals undergo some degree of psychological shock, depression, and loss of self-esteem after the loss of their teeth. Optimum success in the treatment of the edentulous patient can no longer be limited to the proper fit, function, speech, selection, and arrangement of teeth. In addition, today's dentists must use treatment strategies that include proper psychological management, caring, and recognition of the importance of the patient's perception of what is personally esthetic. This article addresses the esthetic considerations of this restorative challenge.

Consumer Behavior↗
PubMed1987

Free radicals and Dupuytren's contracture.

The concentration of substrate expressed as hypoxanthine capable of reacting with xanthine oxidase to release superoxide free radicals (O2-) was measured in control and Dupuytren's contracture palmar fascia. In Dupuytren's contracture palmar fascia the concentration of hypoxanthine was six times that of control and was greatest in "nodular" areas. Xanthine oxidase activity was also detected in Dupuytren's contracture palmar fascia. These results suggest a greater potential for hypoxanthine-xanthine oxidase generated oxygen free radical formation in Dupuytren's contracture than in control palmar fascia. Production of free radicals may be an important factor in the pathogenesis of Dupuytren's contracture. The benefit of allopurinol in the management of Dupuytren's contracture and other fibrotic conditions may thus be explained, as allopurinol binds to xanthine oxidase and prevents release of free radicals.

Aged↗
PubMedDate not supplied

The effects of time course after anterior cruciate ligament injury in correlation with meniscal and cartilage loss.

In this study, 130 consecutive patients with anterior cruciate ligament insufficiency who were undergoing ligament reconstruction underwent arthroscopic examination at the time of reconstruction, and any loss of meniscal or chondral integrity was documented in a systematic fashion. In these patients, a greater proportion of the medial meniscus was lost compared with the lateral meniscus (16% versus 5%). On average, 6 cm2 of the articular cartilage was damaged (5.2 cm2) or lost (0.8 cm2), with the area of damage and loss greatest on the medial femoral condyle. Patients whose injuries had occurred more than 2 years before the examination had more than sixfold greater cartilage loss and damage compared with those whose injuries had occurred within the past 2 months. Meniscal loss was associated with a threefold increase in cartilage damage or loss. The group of patients with meniscal loss whose initial anterior cruciate ligament injury occurred more than 2 years before examination exhibited 18 times the amount of cartilage loss or damage as did the group that had no meniscal loss and whose injury occurred less than 1 month before examination.

Adolescent↗
PubMedDate not supplied

Postexercise increase in nitric oxide in football players with muscle cramps.

Nitric oxide, a free radical inter- and intracellular messenger molecule, is important in exercise physiology. This study tested the hypothesis that serum nitric oxide concentrations change after strenuous exercise with severe generalized muscle cramps. The study group consisted of 77 professional football players in preseason training. All players' concentrations of serum nitrite and of other serum chemicals were determined during their preseason evaluations and compared with the concentrations in 40 serum samples taken from 25 of those same players who required intravenous rehydration for severe generalized muscle cramps after a training session. Player weight and percentage of body fat were significantly higher in players who received intravenous fluids than in players who did not. The serum of players requiring intravenous hydration showed evidence of skeletal muscle breakdown (increases in lactate dehydrogenase, creatinine phosphokinase, aspartate aminotransferase, and alanine aminotransferase) and of dehydration (elevations in protein, blood urea nitrogen, and cholesterol). The major finding, however, was a nearly 300% increase in serum nitrite concentrations in players requiring rehydration. There were no correlations between concentrations of nitrate and of any of the other serum chemicals. These data support the hypothesis that large amounts of nitric oxide are synthesized in professional football players after strenuous exercise with severe muscle cramps. The study design did not allow us to determine whether this increase in nitric oxide was due to exercise or muscle cramps or both, but it does provide a basis for evaluating these relationships.

Adult↗
PubMedDate not supplied

The effect of cytokines on the proliferation and migration of bovine meniscal cells.

We determined the effect of cytokines on the proliferation and migration of cells isolated from the inner-third (white-white), middle-third (red-white), and outer-third (red-red) regions of bovine meniscus. Cells from the outer, or peripheral, region of the meniscus exhibited higher DNA synthesis in the presence of 10% serum compared with cells from the inner or central regions. Recombinant human platelet-derived growth factor-AB, hepatocyte growth factor/scatter factor, and bone morphogenic protein-2 stimulated DNA synthesis of all meniscal cells in a dose-dependent manner, with a two- to threefold maximal stimulation at 10 ng/ml. Cell migration was also stimulated by addition of cytokines. Platelet-derived growth factor and hepatocyte growth factor caused an increase in the migration of cells derived from all three zones, while interleukin-1 selectively stimulated the migration of outer-zone meniscal cells. Epidermal growth factor was much less effective and stimulated the migration of cells in the inner and outer zones by 40% to 50%, while bone morphogenic protein-2 and insulin-like growth factor-1 stimulated the migration of meniscal cells from the middle zone by 40% to 50%. The identification of cytokines that stimulate both the growth and migration of meniscal cells may provide new tools for modulation of meniscal healing.

Animals↗
PubMedDate not supplied

Clinical pharmacokinetics of allopurinol.

Allopurinol is a widely used drug in the management of hyperuricaemia. It is rapidly and extensively absorbed following oral administration. The major and active metabolite, oxypurinol, is detected in the circulation within 15 minutes of allopurinol administration. Oxypurinol concentrations are higher than those of the parent drug and accumulation occurs during long term administration. Up to 80% of allopurinol is recovered in the urine within 24 hours, mainly in the form of oxypurinol. Allopurinol is negligibly absorbed after rectal administration. In animals, allopurinol is found in highest concentrations in vascular tissue, blood, liver, intestine and heart. It is negligibly bound to plasma proteins. Oxypurinol is eliminated by the kidney and has a much longer elimination half-life than allopurinol. Oxypurinol accumulates in patients with renal dysfunction; hence allopurinol dosages should be adjusted in such patients. Allopurinol inhibits the metabolism of 6-mercaptopurine and azathioprine, which require dosage modifications. The interaction of allopurinol with oral anticoagulants and phenytoin has not been clearly established in clinical practice.

Allopurinol↗