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Biomedical subjects

K R Murray

Publications and source records attributed to K R Murray.

6 recordsLinked to original sources
PubMed1992

X-linked spinomuscular atrophy: a kindred with associated abnormal androgen receptor binding.

We studied androgen receptor function in cultured scrotal skin fibroblasts from eight subjects with X-linked spinal and bulbar muscular atrophy (SBMA) (Kennedy's syndrome) from four families. The neuromuscular and endocrine features were similar in all patients. High-affinity dihydrotestosterone binding (Bmax) was decreased in three patients from one family (average, 11.1 fmol/mg) similar to values in subjects with androgen resistance syndromes. Bmax was normal in five SBMA patients from three other families (average, 26.0 fmol/mg). This finding provides direct evidence for abnormal androgen receptor function in some patients with SBMA. There was some correlation between severity of neuromuscular and endocrine dysfunction, providing further evidence that the two types of manifestations are related.

Adult↗
PubMed1986

Influence of lung volume on the mixing defect for an inert gas.

UNLABELLED: For quantitative assessment of how gas mixing in the lung compares to the ideal of perfect mixing, it is necessary to measure pre-inspiratory lung volume as well as to study the inhaled and exhaled gas. Normal young-adult persons in the seated position assumed various lung volumes and then took 1-L test breaths (11% Ar, 22% O2 in N2). Integration of concentration at the mouth against volume yielded amounts of Ar inhaled, exhaled and retained; un-exhaled concentration in the lung after the single breath was calculated from amount retained divided by lung volume (measured by rebreathing). Retention was 60% of the inhaled amount when pre-inspiratory volume was above FRC and less when it was below. Series dead space increased with lung volume. End-tidal Ar was the same as, or slightly above, the concentration predicted for perfect mixing and un-exhaled Ar was slightly below the perfect-mix concentration. INTERPRETATION: three separable influences decrease the transfer of inspirate to the resident gas. A dilution effect, predictable from the volumes involved, decreases retention at low lung volumes. An enlarged series dead space decreases retention at high volumes. In normal persons, a mixing defect that is attributable to poor distribution or incomplete gas-phase diffusion is small and can be ascribed almost completely to the part of the expirate that gives rise to the slope of the alveolar plateau, except when breaths are taken at very low lung volumes.

Adult↗
PubMedDate not supplied

Innominate osteotomy in Perthes disease.

A retrospective study was performed in 27 patients who underwent innominate osteotomy for the treatment of severe Perthes disease. Time intervals between surgery and final follow-up ranged from 5 years to 16 years 4 months. Preoperative and postoperative periods of treatment were often more prolonged than those reported by Salter. One-half of the patients were less than 6 years of age at onset of the disease. A number of patients had significant deformity of the femoral head. Nevertheless, clinically good or fair results were obtained in 88% of the patients and poor results were found in 12%.

Age Factors↗
PubMedDate not supplied

Some factors affecting the size of nylon 6-10 microcapsules prepared by interfacial polymerization in a high-voltage electric field.

The effect of process variables such as nozzle size, flow-rate of dispersed phase, inter-electrode distance, and presence of an acid acceptor and a thickening agent in the dispersed phase, on the production and size distribution of nylon 6-10 microcapsules prepared by interfacial polymerization in a high-voltage electric field was studied. Factors which increased the intensity of the electrostatic forces acting upon the droplets formed, such as increasing nozzle diameter at constant aqueous phase flow-rate and decreasing inter-electrode distance, were found to decrease the capsule size while those which enhanced the availability of the aqueous phase monomer for the polymerization reaction, such as the addition of an acid acceptor and a thickening agent, resulted in an increase in the average size of the capsules obtained. Free flowing capsules and a reduction in the rate of diacid chloride hydrolysis during the process were also obtained with increasing concentration of the thickening agent in the aqueous phase.

Capsules↗