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Biomedical subjects

J Lynn

Publications and source records attributed to J Lynn.

At least 181 records · Page 10Linked to original sources
PubMed1989

Changes in force and intracellular metabolites during fatigue of human skeletal muscle.

1. The relationship between intracellular metabolites and the generation of force during fatigue has been examined in the first dorsal interosseous muscle of the hand. With the arm made ischaemic, the muscle was fatigued by three bouts of maximal voluntary contraction, leaving approximately three minutes ischaemic rest between contractions. During one series of experiments intracellular phosphorus metabolites were measured by nuclear magnetic resonance during the intervals between the fatiguing contractions: in the second series contractile properties were tested with brief electrical stimulation during the rest intervals. 2. The relationships between loss of force and change in metabolite concentrations obtained with four normal subjects were compared with those from one subject with myophosphorylase deficiency (MPD) who could not utilize muscle glycogen and therefore produced no hydrogen ion from glycolysis during exercise. 3. For both the MPD and normal subjects the relationship between relative force loss and inorganic phosphate (Pi) concentration was curvilinear, force changing little in the early stages of the contraction when the intracellular Pi was accumulating rapidly but falling faster when the Pi was above 25 mM and increasing relatively slowly. 4. In the normal subjects intracellular pH fell from a mean of 7.03 +/- 0.01 (mean +/- S.E. of mean, n = 19) in the fresh muscle to 6.51 +/- 0.02 at the end of the fatiguing exercise; force, as a percentage of the initial value, fell in proportion to the increase in H+ concentration. In the MPD subject pH did not change and force loss was therefore independent of H+ accumulation. In the normal subjects the force of the fatiguing muscle showed an approximately linear relationship with the concentration of the monobasic form of inorganic phosphate. However, the MPD subject showed a quite different relationship, with force loss being much greater for a given concentration of monobasic phosphate. This result indicates that monobasic phosphate is not a unique determinant of force loss in fatigued muscle. 5. During the first 60 s of recovery in the normal subjects, pH remained low while force recovered, indicating a mechanism of force loss that was independent of H+ accumulation. However, the recovery of force was not complete, so that for comparable phosphocreatine contents the recovering, more acid, muscle generated less force than the muscle that was being fatigued. It was estimated that H(+)-dependent and independent mechanisms contributed roughly equally to the observed force loss. The relationship between force and the concentration of monobasic phosphate differed in fatiguing and recovering muscle.

Adult↗
PubMed1989

The surgical treatment of adrenal disease.

Since the advent of cortisone replacement therapy in 1950 made adrenal surgery possible, it has had the reputation of being fraught with medical and technical difficulties. However, with good endocrine medical cooperation, expert anaesthesia and sound technical expertise, excellent results are obtainable.

Adrenal Cortex Hormones↗
PubMed1988

Care of dying patients.

Caring for a patient during the last phase of his or her life is a demanding obligation and a privilege for the physician. The physician has the responsibility to be knowledgeable about the natural history of disease processes and the body's changing physiology. The physician must be thorough in the evaluation of the patient, not only in the physical and laboratory examinations, but also by striving to understand the patient psychologically, socially, and philosophically. The caregivers must be open, honest, and compassionate in dealing with the patient and family. The goals are to relieve suffering and to restore function to the fullest attainable extent, so that the patient can live his or her life in the most meaningful way. This requires frequent reevaluation of the patient and the judicious use of appropriate diagnostic and therapeutic modalities. As much as possible, the patient should be involved in the decision making process. The patient should be encouraged to make his or her wishes known before becoming unable to communicate, and should designate someone to act on his or her behalf. The grieving process often starts before death and may continue for many months. Plans should be made to assist the patient and the family in dealing with grief.

Aged↗
PubMed1988

Predicting life span for applicants to inpatient hospice.

The advent of hospice programs and their funding under Medicare has recently made eligibility for substantial insured services turn on whether a patient has less than three or six months to live. The implicit assumption is that physicians can provide this prediction accurately. To test this assumption and to improve predictions, the life spans of 108 consecutive applications for inpatient hospice care were estimated independently by two oncologists, an internist, an oncology nurse, and a hospice social worker, based on data in a ten-page multidisciplinary application packet. The applicants were followed up until death. Actual life span was correlated with predictions. The median (+/- SD) life span was 3.5 +/- 12.4 weeks. The predictions as a group were overly optimistic about survival by an average of 3.4 weeks. The best prognosticator's prediction was only moderately correlated with actual life span, and no two prognosticator's predictions correlated closely with one another. Predicting actual interval until death was more accurate than predicting a 90% confidence interval around the time of death, though the latter procedure was better at avoiding the error of unpredicted long-term survivors. This imprecision in "expert" estimation of life span poses substantial problems for hospice programs and policymakers.

Aged↗
PubMed1987

Patients' views of industrial therapy.

Patients are rarely consulted about the major planning decisions which affect them more than anyone else. The present study, completed in 1984, sought the views of patients in the Industrial Therapy Department of a large psychiatric hospital due for closure in the next decade. Areas covered included what patients felt about the department, attitudes to staff, pay rates and working conditions, and preferences in future care. Results showed a positive attitude to Industrial Therapy tempered by some suggestions for improvement. A preference by a majority of patients for living in the community was backed by a realistic interpretation of the problems involved.

Female↗