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Biomedical subjects

P R Payne

Publications and source records attributed to P R Payne.

18 recordsLinked to original sources
PubMed1979

A comparison of different methods of instrumental delivery based on electronic measurements of compression and traction.

Electronic measurements of compression, using a hydrostatic technique, were made during 44 normal deliveries and compared with the values obtained during 32 deliveries using Kielland's forceps, 21 using Neville Barnes' forceps, 48 using Moolgaoker's adjustable forceps, and 26 using Malmstrom's vacuum extractor. Electronic recordings of traction, using strain gauges, were made simultaneously during all the instrumental deliveries except those with Kielland's forceps. By exercising suitable controls over most of the multiple factors operating at the time of any delivery the authors were able to compare objectively the efficiency of the different methods of instrumental delivery. Smaller forces of compression and traction were exerted and better Apgar scores were recorded in infants delivered with the adjustable forceps than in infants delivered with the other instruments. The superiority of the adjustable forceps was most noticeable during midcavity deliveries of the malrotated head.

Apgar Score↗
PubMed1978

Method to quantify ride comfort and allowable accelerations.

When the motion of a vehicle includes "shocks" or impulsive velocity changes, R.M.S. acceleration has no relation to crew comfort or injury. Existing (R.M.S. G) methods of ride assessment can show lethal accelerations as being perfectly safe, and vice versa. It follows that R.M.S. acceleration is not meaningful for nonsinusoidal "random" vibration either. This paper presents a method of evading the difficulty, using fairly well established biodynamic modeling techniques, and an extension of Allen's "shock tolerance" concept. Among other advantages, the method "automates" the assessment of ride quality so that personal judgments are not involved and the relative ride quality of different vehicles can be placed on a quantitative basis. Since this work was inspired by the problem of Navy crew tolerance to the motions of high-speed ships, the discussion is in those terms. Also, the proposed criteria should probably be scaled down for more general populations.

Acceleration↗
PubMed1978

Functional classification of undernourished populations in the Republic of El Salvador. Methodological development.

Typical government nutrition programmes usually lack precise information on the size of groups that could benefit from interventions, on the different types of potential beneficiaries and their location, and on socio-economic and cultural characteristics through which they could readily be identified. In the functional classification approach to the definition of nutritional problems, detailed information on human behaviour and social constraints is collected at family and community levels. The data are then interpreted in general terms in order to understand how these factors contribute to inadequate levels of nutrition within larger groups. This new approach should enable more effective measures for reducing the numbers of those living under conditions of deprivation to be presented to planners and decision makers.

El Salvador↗
PubMed1977

Mechanisms for the control of body-weight.

Various hypotheses for the mechanism of regulation of body-weight in human adults have been proposed in the light of the magnitude of the long-term changes in weight actually observed. One of these hypotheses has been represented in the form of a computer simulation model which has been used to demonstrate that (i) it is not necessary to postulate the existence of a set-point regulatory system, and (ii) in practice, several mechanisms, including hunger and satiety, the relative constancy of habits and customs of behaviour, and the existence of cognitive thresholds combined with a relatively simple physiological negative feedback system probably constitute the simplest hypothesis for the mechanism of weight stability.

Activities of Daily Living↗
PubMed1977

A model for the prediction of energy balance and body weight.

A model for changes in energy balance and body weight is described which can be written as an iterative computer program. Medium and long-term changes in body weight resulting from random daily fluctuations in energy balance are quantitatively predicted. Body weight varies periodically about a mean value to to the extent of +/- 1 kg over a span of a few weeks. Long-term weight stabilization is the result of a dynamic equilibrium between energy intake and output which depends on activity and tissue metabolism. A lean : fat tissue deposition ratio defines the metabolic type of individual. This ration, which is constant for each individual, governs the proportions in which these tissues are both deposited and mobilized. In the model, the ratio has an important effect on the magnitude and composition of the weight gains resulting from over-eating. It is suggested that the differences in response which have been observed in over-eating experiments result from inter-individual differences in this ratio.

Basal Metabolism↗
PubMed1977

Reducing the hospital stay following vaginal hysterectomy.

A rapidly increasing waiting list in a new National Health service district general hospital made it necessary to explore measures to reduce the length of hospital stay of gynecologic inpatients without lowering the standards of medical care. Three years of experience with patients undergoing vaginal hysterectomy after January 1972 is described. During this time, 290 vaginal hysterectomies were performed and combined with pelvic floor repair in 194 cases. The average hospital stay for such patients was 12.7 days in 1971 before this study was commenced; since then this has been reduced progressively to 7.2 days with a corresponding increase in the number of such operations carried out annually. The effects of routine chemoprophylaxis and a modified technic of vault closure are discussed.

Adult↗
PubMed1976

Energy balance during recovery from malnutrition.

This report presents an account of energy balance of young Jamaican children recovering from protein-energy malnutrition (PEM). This was done in three steps. Initially the true gross energy of a formula used in the treatment of PEM was determined by bomb calorimetry. Then its metabolizable energy content was determined in a group of nine children recovering from PEM. In a similar but different group of eight children total daily metabolizable energy intake (EI), average rate of weight gain (g/kg/day) (WG), and total daily energy expenditure (TDEE) were determined. TDEE was determined by indirect calorimetry using a heart rate counter and is based on the relationship of heart rate to oxygen consumption. In this group, the mean EI was 122.5 kcal, WG was 8.4 g, and TDEE was 92 kcal. The difference between EI and TDEE was 30.7 kcal/kg, or 3.3 kcal/g of weight gain. This difference is presumed to be the stored energy in new tissue and corresponds to a proposed new tissue composition of 31% fat and 14% protein. A regression curve comparison of WG versus EI showed that at zero weight gain EI was 85.5 kcal and each additional gain. The difference of 1.0 kcal between total energy cost and stored energy reflects the energy required to deposit new tissue. Gram weight gain required 4.4 kcal. The latter figure is felt to reflect the total energy cost of weight. From three independent measurements, an estimate of maintenance energy requirements was estimated to be about 82 kcal/kg/day.

Calorimetry↗
PubMed1976

The effect of internal urethrotomy and urethral dilatation on the postoperative course of patients undergoing surgery for stress incontinence.

Three years' experience of a total of 128 patients undergoing surgery for stress incontinence is described. Forty-three patients had an internal urethrotomy performed routinely at the end of the operation, 26 had routine urethral dilatation and 59 had neither procedure. Internal urethrotomy, and to a lesser extent urethral dilatation, resulted in prompt return of spontaneous and efficient micturition following removal of the Foley catheter on the third postoperative day. The postoperative stay averaged 6-4 days in the urethrotomy group of patients, 7-6 days in those who had urethral dilatation and 10-6 days in the others. The two-year cure rate in the patients who had neither procedure performed was 85 per cent and as yet no failures have occurred in the patients who had internal urethrotomy or urethral dilatation performed.

Adult↗
PubMed1975

The protein gap.

Explore the source record for details and available documents.

Age Factors↗
PubMed1975

Safe protein-calorie ratios in diets. The relative importance of protein and energy intake as causal factors in malnutrition.

There has been up to now a lack of agreement as to the way in which protein and energy requirements could be combined to give estimates of adequate dietary protein-energy ratios. In particular, the relevance of the simple ratio, average protein--average energy requirement as a basis for assessing diets, has been questioned on the grounds that it fails to take account of individual variability in needs for energy, and of the extent to which these may be independent of variability in protein requirements. The main problem is to evaluate the range over which individuals can adapt either energy intake to suit expenditure, or expenditure to suit intake, without detriment to health or growth. One solution adopted by Beaton and Swiss in a recent paper is to accept the range of observed variability of energy intakes in normal populations as a measure of this. An alterative is to make use of experimental evidence for the minimum energy intake for maintenance of body energy content. These two approaches are compared, and are shown to give quantitatively similar results. The method based on minimum maintenance requirements offers the further advantage that it allows an assessment of dietary situations in relation to the likelihood of occurrence of different forms of protein--energy malnutrition; those situations in which protein deficiency is a secondary consequence of low energy intake are differentiated from those in which the primary cause is an inadequate level of protein in the diet. The adequate "safe" level of protein-energy ratio in the diets of 2- to 3-year old children is close to 5% and since most varieties of cereal grains appear to provide utilizable protein levels of close to this amount, this lends further support to the view that primary protein deficiency is unlikely to be the main factor causing protein-energy malnutrition in communities for which cereals are the cheapest source of energy.

Breast Feeding↗
PubMed1975

Nutrition and national development planning.

We have argued that development strategies aimed at the reduction of all forms of deprivation, according to an explict statement of values and priorities, are necessary for the integration of nutrition planning into overall national development planning. We do not regard this as likely to lead to the neglect of the key issues of investment and production. Instead, we argue that consideration of investment and production strategies should be explicitly directed to their purpose, the reduction of deprivation, rather than, as in the past, treated as the necessary means to that purpose. Thus investment and production strategies would be aimed directly at relieving deprivation including, especially, nutritional deprivation, and their impact in this respect will need to be explicitly predicted and evaluated. We have argued that problems and potentials differ greatly at the area level and that planning must be an iterative process in which national and area-level strategies and programmes are brought to consistency through successive cycles of adjustment and reappraisal. A major role in planning, especially in detailed design and implementation, is assigned to area level. Planning must proceed from an identification of the deprivations under attack to the identification of intervention measures. Elsewhere we have argued the case for the 'functional classification" of malnutrition and the use of "typical profiles" in the understanding of "the ecology and etiology of malnutition". Where planning accepts the need for an integrated approach to the attack on all forms of deprivation, these analyses of nutritional deprivation would from part of a more comprehensive analysis of general deprivation. The existence of "functional classification" and "typical profiles" analysis with respect to malnutrition would provide an excellent base from which a more comprehensive view might be developed. The factors affecting the evolution of nutritional - and other - deprivation problems need to be understood in order that we can identify points in the system where intervention may control theri emergence. In any situation there will be alternative intervention points bearing either directly on the alleviation of symptoms (malnutrition) or, more or less indirectly, on the control of its causes. In general, mixed strategies will be called for. At this stage in our understanding no generalizations are possible about the nature of strategy choices. Our choice of intervention measures must be based upon an understanding of the overall system as it generates malnutrition, and of which forces exert the most powerful effects. One important element of this analysis will be an understanding of the behaviour of the malnourished. However, conventional planning approaches, in which ministries and departments concern themselves only with problems and measures which conform to the definition of their own spheres of responsibility, have failed to define these choices effectively...

Child↗