PubMed Health⌕ Search

Biomedical subjects

G M Maxwell

Publications and source records attributed to G M Maxwell.

At least 37 records · Page 2Linked to original sources
PubMed1983

Geometrical constraints on the rotational function of the femoral adductors in man.

Various authors have ascribed differing roles to the adductor muscles of the thigh in producing rotation of the femur. In the present study, measurements have been made on the changes in distance between origin and insertion of the adductor muscles which occur with rotation of the femur. Increases in distance indicate the muscle cannot produce a particular movement, while a decrease in length supports an argument that the muscle has a particular function. Measurements were made for positions of flexion-extension and adduction-abduction as well as anatomical rest. The adductor magnus was found to decrease in length during internal rotation while the adductor longus decreased in length during external rotation in most of the positions studied.

Biomechanical Phenomena↗
PubMed1982

Afferent sensory feedback for lower extremity prosthesis.

Electrical stimulation has been applied to sciatic nerves of patients to achieve sensory feedback after lower limb amputation for periods of up to six years. Patients used the sensory feedback device daily. Pain, infection and electrode displacement have not been problems. The immediate postoperative benefits are that pain is minimized after amputation and stump healing is improved. Furthermore, the stimulus affords the patient increased confidence when walking due to renewed awareness of the center of gravity. Improved ability to function in the dark and when walking up and down stairways makes the application of sciatic nerve stimulation after amputation very rewarding.

Amputation, Surgical↗
PubMed1981

The effects of a new anti-hypertensive agent (endralazin) upon the general and coronary haemodynamics of the anaesthetized dog.

The effects of a new anti-hypertensive drug (endralazin) was studied in the intact anesthetized dog; in a dose of 150 millimicron/kg intravenously, the drug increased heart rate, respiratory rate, cardiac output and coronary sinus flow. Systemic blood pressure fell 60 min after the injection. The drug decreased calculated peripheral, pulmonary, and coronary vascular resistance,, amd maintained calculated cardiac efficiency. It also increased blood glucose, non-esterified fatty acid, lactate and pyruvate values, but did not influence cardiac usage of these substrates. There was evidence also of catecholamine release during the period of the study.

Anesthesia↗
PubMed1981

The effects of captopril (SQ14,225) on the systemic and coronary haemodynamics of the intact anaesthetized dog.

1. The effects of Captopril (SQ14,225), an inhibitor of angiotensin-converting enzyme, given intravenously in a dose of 0.3 mg/kg ws studied in intact anaesthetized dogs. 2. The drug caused a decrease in systemic and pulmonary arterial mean pressures, an increase in cardiac output, and hence a decrease in calculated systemic and pulmonary vascular resistances. A sustained tachycardia also occurred. 3. A minor, transient increase in coronary sinus flow was recorded, with a sustained decrease in calculated coronary vascular resistance. 4. No change was found in cardiac oxygen metabolism nor in calculated cardiac efficiency. 5. The plasma renin values increased in the control animals and those given the drug.

Anesthesia↗
PubMed1981

Immunocompetence of children with frequent respiratory infections.

119 children with recurrent respiratory infections were investigated for immunocompetence. They were divided into two groups. The first, group A, comprised children who had had predominantly upper respiratory infections. Group B comprised those who had had repeated pneumonia in addition. The groups were comparable for gender and age (mean 4.2 years). All the children had reduced neutrophil chemotaxis, reduced neutrophil fungicidal capacity, and perhaps reduced T-cell percentages. Group B children had, in addition to the above, decreased neutrophil bactericidal capacity and a more marked depression of neutrophil chemotaxis. In both groups, some children had reduced immunoglobulin concentrations while others had either normal or increased concentrations. Serum complement, neutrophil iodination, and mitogen-induced lymphocyte transformation were comparable with adult controls in both groups.

Adolescent↗
PubMed1978

Primary selective deficiency of immunoglobulin M.

Selective deficiency of IgM as a primary disorder is seldom encountered1--3, and the syndrome remains ill-defined4. It is generally accepted that for a diagnosis to be made, the serum IgM level should be consistently below 2 SD of normal, no other immunodeficiencies are present, and it is not secondary to other disease processes4. This report of an additional case may provide further insight into this rare disease.

Adolescent↗
PubMed1978

Urinary content of 3',5'-adenosine monophosphate (cAMP) and creatinine in full-term and premature infants.

Cyclic 3',5'-monophosphate (c-AMP) and creatinine were measured in full-term and premature infants. In normals, values for c-AMP were highest on days 1 and 2 (1.3-1.5 nmol/ml) and decreased thereafter. In prematures the c-AMP values were significantly lower than in the full-term infants. There was a rough correlation with birth weight. Creatinine values were closely reflected by the c-AMP levels. Changes found in neonatal jaundice, hypocalcaemia, respiratory distress syndrome, and anoxia could be attributed to prematurity. No diurnal variation in c-AMP values was found.

Creatinine↗
PubMed1977

Electrical bone-growth stimulation in an experimental model of delayed union.

An experimental model has been devised for the consistent production of delayed bone healing of the tibia in adult dogs. A double-blind trial, with bias eliminated, was used to evaluate the use of a commercially available direct-current bone-growth stimulator with this model. The stimulator produced a statistically significant acceleration of bone healing at four weeks in the experimental model. Osteogenesis was normal, and no dysplastic, inflammatory, or neoplastic changes were found. This research has shown that electrical stimulation of bone is safe and augments bone formation. The bone-growth stimulator unit remains on trial, but in future it may alter the management of many difficult orthopaedic problems.

Animals↗
PubMed1977

Experimental delayed union of the dog tibia and its use in assessing the effect of an electrical bone growth stimulator.

A technique has been described for the consistent production of delayed bone healing of the tibia in an animal model. A controlled double blind trial, where independent observors did not know the coding of the stimulators and did not collaborate with each other, has evaluated the use of a direct current bone growth stimulator in such an animal model. The conclusion of the experiment is that this commercially available direct current stimulator does produce a significant acceleration of bone healing at 4 weeks in the experimental model used. There is no evidence of inflammatory or neoplastic changes. The eventual clinical role of electrical bone stimulation remains uncertain and many questions remain unanswered, but are promising enough to encourage a controlled clinical trial in situations of disturbed bone healing. Electrical stimulation is apparently safe and appears to significantly augment bone formation. A controlled clinical trial is now being carried out in major medical centers in Australia.

Animals↗
PubMed1975

The effects of a new xanthine derivative, 3,7-dimethyl-1(5-oxohexyl)-xanthin (pentoxifylline) on the general and cardiac haemodynamics of the intact animal.

A study has been made of the effects of xanthine derivative (pentoxifylline) upon the general and cardiac haemodynamics of intact anaesthetised dogs. The drug increased heart-rate, respiration rate, cardiac output and systemic pressure. It reduced mean pulmonary arterial pressure. Coronary flow was increased for only a few minutes, but coronary sinus O2 content increased throughout the study. Lactate and pyruvate values increased in both artery and coronary sinus, as did the cardiac extraction of these substances. Cardiac extraction of non-esterified fatty acid increased.

Animals↗