Search PubMed⌕ Search

Biomedical subjects

J Dove

Publications and source records attributed to J Dove.

49 records · Page 3Linked to original sources
PubMed1982

Highly activatable adenylate cyclase in [2-3H]adenine-prelabeled vesicles prepared from guinea pig cerebral cortex by a simplified procedure.

An improved procedure utilizing a simple fractionation technique is described for the preparation and use of [2-3H]adenine-prelabeled vesicles from guinea pig cerebral cortex containing highly responsive adenylate cyclase activity. Adenosine consistently increased activity 1500--2000%, contrasted with activations of 200--300% previously reported by other investigators. Adenosine at 5 microM was more active in our system than at 20 times this concentration in studies by other investigators, increasing activity by 580--840%. Experimental conditions were explored, and Ca2+ was found to be necessary during tissue homogenization, but not during subsequent vesicle incubation. However, neither the higher Ca2+ concentration used by us (2.5 mM) nor the method of tissue homogenization could adequately explain the high activity of our preparations. The size of the incubation vessel was critical for both low basal activity and high activity in the presence of adenosine. Our preparations were similar to others in that combinations of neurohormones, which included histamine and epinephrine, elicited higher activities than individual neurohormones. Inspection of our vesicle preparations by scanning electron microscopy also showed them to be compatible with previously described preparations.

Adenine↗
PubMed1980

Complete fractures of the femur in Paget's disease of bone.

Complete fractures through bone affected by Paget's disease may not deserve their innocent reputation. This retrospective study of 182 such femoral fractures, the largest reported series to date, was carried out to discover the behaviour of these fractures in the absence of specific therapy for the Paget's disease. Most previous series have concluded that healing is uneventful but the findings in these patients from the West Midlands do not bear this out. After exclusion of the early deaths, the overall incidence of non-union was 40 per cent, the main problems being posed by the subtrochanteric fractures and those of the upper shaft. Although callus may be abundant, it may itself be involved in the disease process and is not a reliable sign of union. Based on these observations, suggestions for management in the different regions of the femur are made.

Aged↗
PubMed1980

The cervical spine after halo-pelvic traction. An analysis of the complications of 83 patients.

This retrospective study assesses the complications affecting the cervical spine after halo-pelvic traction in 83 patients who were followed up for a minimum of five years. Forty-four patients (53 per cent) had significant cervical complications such as radiological degenerative changes, avascular necrosis of the dens, loss of movement, pain or spontaneous fusion. The most important predisposing factors were a long period in the halo-pelvic apparatus, tuberculous kyphosis, stiffness of the spinal deformity and an age of 15 years or more at the time of application.

Adolescent↗
PubMedDate not supplied

Post-poliomyelitis paralytic scoliosis. A review of curve patterns and results of surgical treatments in 118 consecutive patients.

Curve patterns and surgical treatment in 118 consecutive patients with post-poliomyelitic paralytic scoliosis are reviewed. The typical curve pattern was double structural curves, usually including the lumbar spine. Modifying the incision and altering the sequence of instrumentation facilitated both the exposure and instrumentation of the fourth and fifth lumbar bodies. Anterior fusion and Dwyer's instrumentation yield most of the correction of pelvic obliquity and significant correction of both the upper and lower curves. Two weeks of halofemoral traction did not achieve significant curve correction. It is suggested that staged anterior and posterior procedures result in structural correction of pelvic obliquity and paralytic scoliosis in severe deformities equal to the degree of correction obtained using posterior fusion and instrumentation alone in less severe cases.

Adolescent↗
PubMedDate not supplied

Avascular necrosis of the dens: a follow-up study.

In order to determine the long-term consequences of avascular necrosis of the dens following halo-pelvic traction, 83 patients who had had their halo-pelvic apparatus removed at least five years previously were studied. Avascular necrosis of the dens was found in 31 patients (37%) within one year of removal of the apparatus, but after a minimum of five years the early bony changes had resolved and there was no evidence of atlantoaxial instability. However, 19% of patients who had had avascular necrosis had moderate or severe neck symptoms.

Adolescent↗
PubMedDate not supplied

The implanted electrical resistance strain gauge: in vitro studies on data integrity.

The aim of this research is to investigate, and thus counter, the adverse effects of tissue fluid ingress on the performance of the electrical resistance strain gauge when used in ascertaining in vivo loading on a spinal implant. Moisture absorption has been minimized by adopting maximum metallic coverage in a package comprising stainless steel foil on vacuum-injected pacemaker grade epoxide. In a simulation of the implanted environment, cyclic strain wet endurance testing in saline suggests that, in the body, the fall in indicated quasi-dynamic strain would be less than 1.5% at 24 weeks post-operation (the longevity needed to span adequately the bony fusion phase). This implies that stiffening of the fusion mass will be deducible to a similar accuracy (from stepped-load exercises), in which creep is a secondary effect. However, crucial information (from quasi-static (passive) studies) regarding remodelling and load-sharing processes would be subject to a total signal error (primarily due to grid corrosion) in excess of 16% by 24 weeks, since long-term drifts are not inherently cancelled. Signal compensation is therefore additionally required, and an approximate empirical characterization of total error versus time has been derived.

Animals↗