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Biomedical subjects

J K Nelson

Publications and source records attributed to J K Nelson.

51 records · Page 3Linked to original sources
PubMed1975

Comparative trial of propranolol and practolol in hyperthyroidism.

The possible role of practolol in the management of hyperthyroidism has been studied by comparing it with propranolol. 2. In a double-blind cross-over trial, propranolol (40 mg), practolol (120 mg) and a placebo four times daily for one week were compared in twenty-one hyperthyroid patients by sequential analysis. 3. Judged by their effect on the symptoms and signs of thyrotoxicosis, both propranolol and practolol were significantly better than the placebo but no clear distinction could be made between the two active compounds. 4. Propranolol and practolol reduced heart rate by 24 and 17% respectively compared with placebo. 5. Patients generally preferred propranolol or practolol to placebo but this preference did not achieve significance with either drug. 6. Only in its effect on heart rate was practolol significantly inferior to propranolol, and it would appear to be a useful alternative to propranolol in the management of the peripheral manifestations of hyperthyroidism.

Clinical Trials as Topic↗
PubMedDate not supplied

Achieving optimal diabetic control in adolescence: the continuing enigma.

The transition from childhood through adolescence to adulthood is a difficult stage, particularly for patients with type 1 diabetes. The yearning for autonomy and independence, as well as the hormonal changes around the time of puberty, can manifest in poor glycaemic control. The focus on diet and weight increases the prevalence of eating disorders, compounding the difficulties in supervising diabetes patients. This can be exacerbated by the realisation that hyperglycaemia induces weight loss and the use of this knowledge to further manipulate diabetes control to gain a desired body image. The management of adolescents with type 1 diabetes is therefore challenging and requires close collaboration between psychological medicine and diabetes teams. This review describes the difficulties frequently encountered, with a description of four cases illustrating these points. Case 1 demonstrates the problem of needle phobia in a newly diagnosed patient with type 1 diabetes leading to persistent hyperglycaemia, the recognition of weight loss associated with this and the development of bulimia. The patient's overall management was further complicated by risk-taking behaviour. By the age of 24 years, she has developed diabetic retinopathy and autonomic neuropathy and continues to partake in risk-taking behaviour. Case 2 illustrates how the lack of parental support shortly after the development of type 1 diabetes led to poor glycaemic control and how teenagers often omit insulin to accommodate lifestyle and risk-taking behaviour. Case 3 further exemplifies the difficulty in managing patients with needle phobia and the fear of hypoglycaemia. Case 4 adds further weight to the need for parental support and the impact of deleterious life events on glycaemic control by manipulation of insulin dosage.

Adolescent↗
PubMedDate not supplied

Mechanical evaluation of two canine iliac fracture fixation systems.

Twenty-three canine pelves were tested bilaterally to determine the stiffness and strength of intact ilium and stabilized oblique iliac osteotomies that simulated a common clinical fracture. Fixation systems tested were three 4.0 mm cancellous screws inserted ventral to dorsal across the osteotomy site and one laterally placed five hole 3.5 mm dynamic compression plate. Specimens were mechanically tested to failure under torsional, axial, or axial plus bending loads. Lag screw fixation was stiffer and stronger than plate fixation in all testing modes. The differences were statistically significant (p less than .05) in the torsional and axial plus bending loading modes. Fatigue testing was performed on implanted specimens with low-level cyclic loading under axial plus bending loading conditions. Physiologic loading conditions failed to produce mechanical failure of either fixation system after 100,000 cycles.

Animals↗
PubMedDate not supplied

System behavior of commonly used cranial cruciate ligament reconstruction autografts.

Biomechanical analysis was performed on the cranial cruciate ligament (CCL) and three autogenous tissues used for CCL reconstruction in the canine stifle. The autogenous tissues were patellar ligament-based autografts described for over-the-top CCL replacement and included the central one third of the patellar ligament, the medial one third of the patellar ligament, and the lateral one third of the patellar ligament with fascia lata. Tension testing produced abrupt failure of the central and medial autografts but sequential failure of the lateral autograft. Structural properties were determined for the overload condition and within the load range of normal activity for the CCL (physiologic range). None of the autograft systems approached the stiffness, maximum load, and energy absorbed to maximum load of the CCL. The central and lateral autografts were stiffer, had greater maximum loads, and absorbed more energy to maximum load than the medial autograft. The central and lateral autografts had an elastic range, as defined by proportional limit, which corresponded to the physiologic range of loading for the CCL. Loads that corresponded to physiologic displacement of the lateral and central autografts were near the maximum load of the fixation site, which underscored the need for postoperative support of the repaired stifle.

Animals↗