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Biomedical subjects

R F Drewett

Publications and source records attributed to R F Drewett.

At least 37 records · Page 2Linked to original sources
PubMed1992

Weaning practices and breast-feeding duration in Northern Thailand.

Current infant feeding guidelines recommend exclusive breast-feeding until the infant is about 4 months old to reduce the risks of early termination of breast-feeding, undernutrition and infection. In many societies, however, supplementary foods are given well before 4 months of age. The present paper describes weaning practices, factors associated with early supplementation and the effects of supplementation on duration of breast-feeding in a random sample of sixty northern Thai breast-fed infants studied prospectively from birth to 2 years of age. Composition of supplementary foods, energy and protein intake from supplements and changes in the supplementary diet with increasing infant age are also described. Rice-based foods were given from soon after birth; 81% of the sample had received supplements by 6 weeks of age. Early supplementary feeding was significantly associated with rural residence, large household size, maternal employment in agriculture and maternal age. Girls and infants with lower birth weights tended to be supplemented earlier. Despite early feeding of supplements, breast-feeding was prolonged, with median duration of 12 months. Early introduction of supplements and quantity of supplements consumed in the first 3 months were not associated with duration of breast-feeding. However, mothers who gave infant formula as the first supplementary food stopped breast-feeding slightly earlier, as did younger mothers living in households with more children.

Breast Feeding↗
PubMed1992

Measuring outcome of total knee replacement using quality of life indices.

A series of 26 patients was studied before and after total knee replacement to determine the change in their quality of life, expressed as a gain in Quality Adjusted Life Years (QALYs). Global health status was assessed using the Nottingham Health Profile, disability by the Harris scale, pain by the McGill Pain Questionnaire, and anxiety and depression by the Hospital Anxiety and Depression Scale. Substantial reductions were found in pain, anxiety and depression, and a significant improvement was found in mobility. These data were used to generate a 'QALY' (Quality Adjusted Life Year) comparable to the measure used by Williams (1) in his comparative evaluation of medical and surgical treatments. A gain of only 0.42 QALY was found for knee replacement, which is about one-tenth the figure given by Williams for hip replacement. The difference appears to be attributable not to differences in the success of the operations, but rather to the scope that QALY calculations give for allocating comparable patients to different quality of life states. Tighter criteria are needed if QALYs are to be used to guide resource allocation.

Aged↗
PubMed1991

Successful sustained lactation following postpartum tubal ligation.

This study was undertaken to see whether tubal ligation performed within days postpartum, and associated with a delay in the initiation of breastfeeding, exerts a disruptive influence on successfully establishing lactation among the rural population of northern Thailand. Lactational performance of 12 rural northern Thai mothers was not affected by the delay in reunion of mothers with their babies as a result of postpartum tubal sterilization procedure when compared with a group of 8 other healthy mothers and babies. The volume of breast milk transferred, frequency of breastfeeding and the total feeding time spent on the breast were similar on days 15, 45, 90, 180 and 360 postpartum. This finding suggests that the pattern of intense breastfeeding activity as practiced by this group of mothers has a stronger influence on prolonged and successful lactation than early contact in the immediate postpartum period.

Adult↗
PubMed1989

Relationships between nursing patterns, supplementary food intake and breast-milk intake in a rural Thai population.

Relationships between nursing patterns, supplementary food intake and breast-milk intake were examined in a group of 52 Thai babies under 1 year of age. All data were collected over two consecutive days, 24 h/day. Total sucking time (min/day) and supplementary food intake (kcal/day) were significant predictors of breast-milk intake after allowing for the age of the baby: R-squared is 0.32 for sucking time and 0.39 for supplementary food intake. The two variables were themselves correlated (r is -0.47). The number of breastfeeds per day and their mean duration was determined for each case, counting each episode of attachment to the breast as a separate feed. Number and mean duration of breastfeeds were then evaluated as predictor variables. The duration of feeds had no predictive power. Number of feeds was linearly related to milk intake and combined with age was as good a predictor of milk intake as total sucking time (with R-squared 0.34). These results suggest that a simple count of breastfeeds is as valuable as more complex measures of sucking duration in predicting to breast-milk intake.

Breast Feeding↗
PubMed1989

The bacterial content of infant weaning foods and water in rural northern Thailand.

Samples of weaning food and supplementary water were collected for analysis of bacterial content from among a random sample of 65 infants under the age of 1 year living in a rural area of northern Thailand. Using geometric means, mean total bacterial count of infant's drinking water was 351 organisms/ml (95 per cent CIs 170-770), and the most probable number (MPN) of faecal coliforms/ml was 47 (95 per cent CIs 19-78). Mean total bacterial count of weaning foods was 38,000 (95 per cent CIs 25,000-59,000) organisms/g with 10 per cent recording counts greater than 1,000,000 organisms/g. Bacterial counts were similar to those reported in weaning food and water in other developing countries, and were above internationally recommended 'safe' levels. The bacterial count of water was not affected by boiling, due to poor cleaning and frequent re-use of utensils. Weaning foods were contaminated during preparation, in part through premastication and also via mode of cleaning of utensils.

Colony Count, Microbial↗
PubMed1989

Predictors of breast milk intake in rural northern Thailand.

A random sample of 52 mothers and infants from a rural area of Northern Thailand were studied in their homes for 48 h. Infants were breast fed on demand. Daytime feeds were test weighed with electronic averaging balances and nighttime intake estimated using a new method, Indirect Test Weighing. All feeds, both day and night, were timed to the nearest minute. Other variables measured by direct observation were infant weight, and supplementary food and water intake. Mean 24-h breast milk intake was 579 g (range 78-1,011 g) with a median between day coefficient of variation of 8.8%. The proportion of 24-h breast milk intake consumed at night ranged from 8 to 91%, and increased with increasing infant age. Significant positive associations were found between breast milk intake, and sucking time and infant weight. There were significant negative associations between breast milk intake and age, and supplementary food and water intake.

Body Weight↗
PubMed1988

Infant weight in relation to nutritional intake and morbidity in northern Thailand.

A cross-sectional study of 58 infants (age range 2-53 weeks) was carried out in a rural area of northern Thailand. Total dietary intake (energy and protein from breastmilk and supplementary food) was measured directly during continuous observation over 48 h of randomly selected study subjects in their homes. Associations between infant weight and total energy intake, total protein intake and morbidity were analysed by multiple regression analysis. Up to 6 months of age, heavier infants had larger energy intakes, when age and birthweight were taken into account. In the 7-12 months age group, heavier infants consumed more protein and had fewer respiratory infections. Weaned infants older than 6 months were significantly heavier and consumed more protein than infants of similar age who were still receiving breastmilk. The lower protein intakes of the latter infants were due to the low protein concentration of breastmilk compared with supplementary food.

Body Weight↗
PubMed1987

Serum prolactin and cortisol levels after suckling for varying periods of time and the effect of a nipple shield.

Plasma prolactin and cortisol levels were measured in mothers breast feeding with or without the use of a thin latex nipple shield, and in mothers wearing a nipple shield but who were not nursing. Suckling duration and milk transfer were also recorded. Suckling duration ranged between 6 and 31 min, being significantly correlated with prolactin levels 40 to 120 min after the feed started. At the latter time, baseline prolactin level and time spent nursing accounted together for most of the variance in prolactin levels: R2 was 0.79 and 0.82 at 90 min and 120 min respectively. Prolactin was released as usual when the shield was in place: levels were not significantly different from levels without the shield. Suckling duration was also unaffected by the shield, but milk transfer was significantly reduced. Cortisol was not released by using the shield, and the shield alone (without suckling) did not release prolactin. The thin latex nipple shield has therefore no untoward effect on the release of these hormones during nursing.

Adolescent↗
PubMed1984

Evaluating breast-milk intake by test weighing: a portable electronic balance suitable for community and field studies.

A K-Tron Digital Scale (Model DS-1) was used to weigh a group of 52 new born babies. The regression of the weights on true weights obtained with a Sartorius electronic balance 3806MP was 0.9911, with an estimated residual variance of 5.25. With the same babies weighed on a Marsden Weighmaster, the estimated residual variance was 68.93. Data from published studies on other balances are presented for comparison. The K-Tron is a reliable, portable, battery operated balance suitable for measuring milk intake by test weighing in homes or in the field.

Biometry↗
PubMed1982

Individual patterns of milk intake during breast-feeding.

The pattern of milk transfer during breast-feeding was ascertained for individual mother-infant pairs using a 'fractional' weighing technique. This method employs a single, fixed intermediate weighing on each breast, and a flexible, final weighing point at the 'natural' termination of feeding on each breast. The data demonstrate considerable variability between individuals both in feed length and in the rate of milk transfer from mother to baby. They show that the rate of intake tends to be consistent between the first and second breast, and that each mother-infant pair has a characteristic rate of milk transfer. Significant milk intake occurred from four minutes to the end of the feed on each breast. These results imply that breast-feeding 'rules' about the length of a feed can only be offered as helpful guidelines, rather than principles to be strictly followed. The results of a reciprocal nursing experiment suggest that the typical rate of milk transfer is a product of both milk release by the mother and milk demand by the baby.

Body Weight↗
PubMed1982

A quantitative analysis of the feeding behavior of suckling rabbits.

Three experiments are reported on the feeding behavior of suckling rabbits ("kittens"). In the 1st the latency with which the kittens attached to the nipple, and then left the nipple, was determined. Attachment was very rapid and wholly reliable: on the 80 tests the nipple was seized in every case in under 9 sec, and on 67 of these in less than 3 sec. The kittens also invariably left the nipple within the next minute. If the kittens were 5 or 10 days old speed of attachment was unaffected by the presence or absence of saliva on the nipple, but 15- and 20-day-old kittens seized the sucked nipples more rapidly than the unsucked nipples. In a 2nd experiment with 12-day-old kittens, washing the nipple with solvents did not affect speed of attachment; nor did saliva. The results show that suckling rabbits, in contrast to rat pups, are not heavily dependent on saliva cues. In the 3rd experiment both attachment latency and milk intake were shown to be affected by an internal stimulus, a gastric load of.9% saline, 5 g/25 g body weight: attachment latency was significantly increased and milk intake reduced by 75%.

Animals↗
PubMed1982

The continuous measurement of milk intake at a feed in breast-fed babies.

A method for the continuous measurement of milk intake during a breast-feed is described. A miniature Doppler ultrasound flow transducer, located in the tip of a latex nipple shield, is interposed between mother and baby during feeding. Preliminary results indicate the scope and current limitations of the method in terms of both populations and individual mother/infant pairs. An initial analysis of individual feeds indicates that two factors may contribute to the curtailment of intake during a feed from one breast: a progressive reduction in intake volume per suck, and/or an increase in the proportion of time spent pausing between bursts of sucking.

Breast Feeding↗
PubMed1982

Milk flow and sucking rates during breast-feeding.

This study examined sucking patterns during breast-feeding in order to investigate the supposed 'nutritive' and 'non-nutritive' sucking dichotomy. The intervals between sucks were determined: they indicated that there is no bimodal distribution corresponding to 'nutritive' and 'non-nutritive' rates of sucking, but rather a complete gradation between the two. In a further experiment in which milk flow was assessed by test-weighing the baby at three-minute intervals during feeding, there was a linear relationship between milk flow and sucking rate: the higher the milk flow, the lower the sucking rate. These results were further substantiated by testing the sucking rate on an empty and full breast, and the sucking pattern of an infant with a non-lactating mother. The study shows that there is no dichotomy between two sucking rates, but rather a continuous variation in response to milk-flow rate.

Breast Feeding↗
PubMed1981

Effect of testosterone on neuronal refractory periods, sexual behaviour and luteinizing hormone: a comparison of time-courses.

Measurements of the refractory period of stria terminalis neurones that are sensitive to testosterone propionate, of sexual behaviour and of plasma levels of LH were taken in castrated rats at various times after initiation of treatment with testosterone propionate. Levels of LH dropped within 24 h, before there was any change in neuronal refractory periods. The period of latency to mounting, however, was reduced to its shortest only after 7-8 days and ejaculations first occurred at the same time; these sexual responses correlated in time with reduction of the neuronal refractory period to its lowest level.

Amygdala↗