Growth in preterm infants fed either a partially hydrolyzed whey or an intact casein/whey preterm infant formula.

OBJECTIVE: To compare feeding tolerance, nutrient intake and growth in preterm infants (< or =32 weeks, < or =1750 g) fed either a standard nonhydrolyzed whey-casein (nHWC) or a partially hydrolyzed whey (pHW) preterm infant formula. STUDY DESIGN: In this double-blind randomized controlled trial infants were fed either formula for at least 3 weeks. Intake was monitored daily, serum chemistries and growth weekly. Data were analyzed using analysis of covariance. RESULT: A total of 80 infants were enrolled, 72 completed the study. No differences were noted in demographic characteristics. No differences were detected in feeding tolerance, intakes (118+/-21 vs 119+/-14; nHWC vs pHW) or growth weight, 28+/-1.5 vs 28+/-1.6 g per day; length, 1.0+/-0.7 vs 1.0+/-0.6 cm per week; head circumference, 0.9+/-0.4 vs 1.0+/-0.44 cm per week). At the end of study, blood urea nitrogen (5.2+/-3.1 <6.7+/-2.3 mg per 100 ml, nHWC4.4+/-0.5 g per 100 ml) and albumin (2.7+/-0.3 >2.6+/-0.4 g per 100 ml) differed. CONCLUSION: A pHW preterm infant formula was not associated with improved feeding tolerance, enteral intake or growth but differences in serum chemistries. These are unlikely to be clinically relevant because values were well within normal limits for preterm infants, whereas growth was identical in both groups and paralleled that 'in utero'.

Costs to farmers of a tuberculosis breakdown.

An on-farm survey of 151 cattle farmers who had experienced a bovine tuberculosis (Mycobacterium bovis) breakdown on their farms was undertaken in 2003 to assess the costs associated with the breakdown. In 90 per cent of cases the cost was estimated to be less than 18,513 pounds sterling for dairy herds and less than 11,462 pounds sterling for beef herds, but with a range from 229 pounds sterling to 103,817 pounds sterling. The main cost was the slaughter of reactor cattle. For the majority of the farmers, the compensation payments seemed to meet most of the costs of their breakdowns, although a majority was still left with net losses.

Postnatal growth retardation: a universal problem in preterm infants.

BACKGROUND: Previous data from this unit suggest that postnatal growth retardation (PGR) is inevitable in preterm infants. However, the study was performed in a single level III neonatal intensive care unit and applicability of the findings to other level III or level I-II special care baby units was uncertain. OBJECTIVES: To examine postnatal hospital growth and to compare growth outcome in preterm infants discharged from four level III tertiary care units and 10 level I-II special care baby units in the former Northern Region of the United Kingdom. SUBJECTS/METHODS: Preterm infants (< or = 32 weeks gestation; < or = 1500 g) surviving to discharge were studied. Infants were weighed at birth and discharge. Body weight was converted into a z score using the British Foundation Growth Standards. To ascertain the degree of PGR, the z score at birth was subtracted from the z score at discharge. Data were evaluated using a combination of split plot (level III v I-II=main factor; individual centre=subfactor) and stepwise regression analyses. Results were considered significant at p < 0.05. RESULTS: A total of 659 (level III, n = 335; level I-II, n = 324) infants were admitted over a 24 month period (January 1998-December 1999). No differences were detected in birth characteristics, CRIB score (a measure of illness in the first 24 hours of life), length of hospital stay, weight gain, weight at discharge, or degree of PGR between infants discharged from level III and level I-II units. Significant variation was noted in length of hospital stay (approximately 35%; p < 0.001), weight gain (approximately 33%; p < 0.001), weight at discharge (approximately 20%; p < 0.001), and degree of PGR (approximately 200%; p < 0.001) between the level III units. Even greater variability was noted in the duration of hospital stay (approximately 40%; p < 0.001), weight gain (approximately 60%; p < 0.001), weight at discharge (approximately 40%, p < 0.001), and degree of PGR (approximately 300%, p < 0.001) between the level I-II units. CONCLUSIONS: These data stress the variable but universal nature of PGR in preterm infants discharged from level III and I-II neonatal intensive care units and raise important questions about nutritional support of these infants before and after hospital discharge.

The development of multiplex simple sequence repeat (SSR) markers to complement distinctness, uniformity and stability testing of rape (Brassica napus L.) varieties.

To assess the potential of multiplex SSR markers for testing distinctness, uniformity and stability of rape (Brassica napus L.) varieties, we developed three multiplex SSR sets composed of five markers each. These were used to measure the extent of diversity within and between a set of ten varieties using a fluorescence-based semi-automated detection technology. Also, we evaluated the significance of any correlation between SSRs, pedigree and five of the morphological characters currently used for statutory distinctness, uniformity and stability testing of rape varieties. An assignment test was allowed to identify 99% of the plants examined, with the correct variety based on the analysis of 48 individual plants for each variety. Principal coordinate analysis confirmed that a high degree of separation between varieties could be achieved. Varieties were separated in three groups corresponding to winter, spring and forage types. These results suggested that it should be possible to select a set of markers for obtaining a suitable separation. Diversity within varieties varied considerably, according to the variety and the locus examined. No significant correlation was found between SSR and morphological data. However, genetic distances measured by SSRs were correlated to pedigree. These results suggested that SSRs could be used for pre-screening or grouping of existing and candidate varieties, allowing the number of varieties that need to be grown for comparison to be reduced. Multiplex SSR sets gave high-throughput reproducible results, thus reducing the costs of SSR assessment. Multiplex SSR sets are a promising way forward for complementing the current variety testing system in B. napus.

Temporal flux in the morphological and molecular diversity of UK barley.

Genetic-diversity assessments, using both phenotypic and molecular-marker data, were made on a collection of 134 barley varieties (both winter and spring types), chosen on the basis of their representation on the NIAB "Recommended List" over the period 1925-1995. Genotypic (AFLP and SSR) and phenotypic (UPOV characters) data were analysed to determine short- and long-term temporal trends in diversity over the period. A consistent pattern emerged demonstrating that only a minor proportion of the overall variance appears to be the result of any temporal drift, although there were strong indications of qualitative shifts in diversity, probably related to the changing relative acreage of winter and spring barleys over the study period. Our overall conclusions are that systematic plant breeding does not inevitably lead to a reduction in the genetic diversity of agricultural crops, and that diverse breeding programmes and the variety delivery systems in place in the UK have generally been successful in maintaining sufficient genetic diversity to allow the steady rise in genetic potential that has been a feature of 20th century crop breeding. The concentration of breeding effort into a smaller number of independent programmes is likely to be prejudicial to the maintenance of the genetic diversity of a crop.

Zinc protoporphyrin/haem ratio and plasma ferritin in preterm infants.

OBJECTIVE: To study the utility of the zinc protoporphyrin/haem (ZPP/H) ratio as a measure of iron status in healthy, growing, preterm infants. METHOD: ZPP/H was measured in 109 well, preterm infants from the time of hospital discharge until 1 year of age (637 determinations). RESULTS: ZPP/H was initially high, but steadily declined. This was opposite to what was expected from the known changes in iron stores during the first year of life and the observed changes in plasma ferritin. Subjects with higher ZPP/H ratios tended to have lower ferritins, but changes in ZPP/H in a given subject were poorly reflected by changes in plasma ferritin. Between 6 and 9 months of age, ZPP/H correlated with other measures of iron status, but serum ferritin concentration did not. CONCLUSION: Use of the ZPP/H ratio as a measure of iron status during the first year of life appears to be confounded by the developmental changes in ZPP/H, but in the later half of this period it may be a better measure of iron status than serum ferritin.

Construction and analysis of a microsatellite-based database of European wheat varieties.

A database of 502 recent European wheat varieties, mainly of winter type, was constructed using 19 wheat microsatellites and one secalin-specific marker. All datapoints were generated in at least two laboratories using different techniques for fragment analysis. An overall level of >99.5% accuracy was achieved. The 199 alleles detected allowed discrimination between all of the varieties except duplicates, and varieties derived from identical parents. Approximately 25% of the varieties showed some heterogeneities, with the highest level of heterogeneity in south-eastern European material. The highest genetic diversity and the highest number of rare alleles were found in varieties from southern Europe. The relative allele frequencies varied for most microsatellites in different geographical regions.

Feeding preterm infants after hospital discharge: growth and development at 18 months of age.

We have shown that preterm infants fed a preterm formula grow better than those fed a standard term infant formula after hospital discharge. The purpose of this follow-up study was to determine whether improved early growth was associated with later growth and development. Preterm infants (< or =1750 g birth weight, < or =34 wk gestation) were randomized to be fed either a preterm infant formula (discharge to 6 mo corrected age), or a term formula (discharge to 6 mo), or the preterm (discharge to term) and the term formula (term to 6 mo). Anthropometry was performed at 12 wk and 6, 12, and 18 mo. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 mo. Differences in growth observed at 12 wk were maintained at 18 mo. At 18 mo, boys fed the preterm formula were 1.0 kg heavier, 2 cm longer, and had a 1.0 cm greater occipitofrontal circumference than boys fed the term formula. Boys fed the preterm formula were also 600 g heavier and 2 cm longer than girls fed the preterm formula. However, no differences were noted in MDI or PDI between boys fed the preterm formula and boys fed the term formula or between the boys fed preterm formula and girls fed the preterm formula. Overall, boys had significantly lower MDI than girls (mean difference, 6.0; p < 0.01), primarily reflecting lower scores in boys fed the term formula. Thus, early diet has long-term effects on growth but not development at 18 mo of age. Sex remains an important confounding variable when assessing growth and developmental outcome in these high-risk infants.

Postnatal malnutrition and growth retardation: an inevitable consequence of current recommendations in preterm infants?

BACKGROUND: Nutrient intakes meeting recommended dietary intakes (RDIs) take time to establish and once established are rarely maintained throughout hospital stay in preterm infants. A nutrient deficit, therefore, accrues. RDI are based on needs for maintenance and growth, with no provision to replace this deficit. We, therefore, hypothesized that postnatal malnutrition and growth retardation were inevitable in infants fed current RDI. METHODOLOGY: Dietary intakes were prospectively collected, by a single observer (N.P.), on a daily basis in a group of preterm infants (n = 105; birth weight /=31 weeks. By the end of the fifth week, cumulative energy and protein deficits were 813 +/- 542 and 382 +/- 263 kcal/kg and 23 +/- 12 and 13 +/- 15 g/kg and the z scores were -1.14 +/-.6 and -.82 +/-.5 for infants at /=31 weeks. Stepwise regression analysis indicated that variation in dietary intake accounted for 45% of the variation in changes in z score. CONCLUSIONS: Preterm infants inevitably accumulate a significant nutrient deficit in the first few weeks of life that will not be replaced when current RDIs are fed. This deficit can be directly related to subsequent postnatal growth retardation.postnatal growth retardation, preterm infants.

Factors affecting the measurement of energy expenditure during energy balance studies in preterm infants.

Our objective was to examine factors that affect the accuracy of energy expenditure measurements (EE), when using flow-through indirect calorimetry (IC), to determine the minimum length of time needed to measure 24- and 48-h EE and to compare cross-over and parallel designs as methods of investigation during energy balance collections (EB) in preterm infants. A baby doll manikin was used to determine equilibration times and to compare VCO(2) and VO(2) as measured by flow meter and indirect calorimetry under different study conditions, one of which simulated an EB. "Continuous" EE was measured to determine the minimum length of time needed to accurately reflect 24- and 48-h EE and to compare parallel and cross-over studies as methods of study design in a group of "normal" enterally fed preterm infants. The mean (+/-SD) errors between flow meter and indirect calorimetry determinations for VCO(2) and VO(2) were -1.9 +/- 2.5 and -1.8 +/- 4.3% under conditions that simulated an EB. Cumulative 6-h EE accurately predicted 24- and 48-h EE. Expressed in absolute terms (kcal/d), EE did not change on a day-to-day basis but did increase over the 2-wk study period. Expressed on body weight basis (kcal/kg/d), EE did not change on a day-to-day or week-to-week basis. The variance in EE due to biologic variability; i.e. the parallel design, was approximately 6 times greater than that due to age, weight, and weight gain; i.e. the cross-over design. Indirect calorimetry, therefore, accurately measures EE in conditions simulating an energy balance collection. Six-hour EE determinations are valid estimate of EE during a 48-h balance collection, while cross-over studies may be the preferred method of study design during short-term studies of EE in preterm infants.

Feeding preterm infants after hospital discharge: effect of diet on body composition.

Our purpose in this study was to examine whole body composition, using dual energy x-ray absorptiometry (DEXA) during dietary intervention in preterm infants (< or = 1750 g birthweight, < or = 34 wk gestation). At discharge, infants were randomized to be fed either a preterm infant formula (discharge-6 mo; group A) or a term formula (discharge-6 mo; group B), or the preterm formula (discharge-term) and the term formula (term-6 mo; group C). Nutrient intake was measured between each clinic visit. To measure body composition, DEXA was used at discharge, term, 12 wk, 6 mo, and 12 mo corrected age. The data were analyzed by ANOVA. At discharge, no differences were noted in patient characteristics between groups A, B, and C. Although energy intakes were similar, protein and mineral intakes differed between groups (A > C > B; p < 0.0001). During the study, weight gain and LM gain were greater in group A than B. At 12 mo, weight, LM, FM, and BMM but not % FM or BMD were greater in group A than B. However, the effects of diet were confined to boys, with no lasting effects seen in girls. In summary, therefore, DEXA was precise enough to detect differences in whole body composition during dietary intervention. Increased weight gain primarily reflected an increase in LM and is consistent with the idea that the preterm formula more closely met protein and/or protein-energy needs in rapidly growing preterm male infants.

Iron nutritional status in preterm infants fed formulas fortified with iron.

AIMS: To prospectively evaluate the iron nutritional status of preterm infants fed either a term (0.5 mg/dl iron) or preterm (0.9 mg/dl) formulas fortified with iron after hospital discharge. METHODS: Healthy low birthweight preterm infants were randomly assigned into three groups at the time of hospital discharge. Group A were fed an iron fortified preterm formula (0.9 mg/dl iron) until 6 months corrected age; group B, a fortified term formula (0.5 mg/l iron) until 6 months corrected age group C, the preterm formula between hospital discharge and term, then the term formula until 6 months corrected age. RESULTS: Seventy eight infants were followed up to 6 months corrected age. Iron intake from formula differed significantly between the groups (A, 1.17 mg/kg/day (SD 0.32) > C, 0. 86 mg/kg/day (SD 0.40) = B, 0.81 mg/kg/day (SD 0.23); p < 0.0001). Haemoglobin concentrations were similar to those of iron sufficient preterm infants of the same postnatal age, and term infants of the same postmenstrual age (after 3 months of age). There were no significant differences in haemoglobin concentration (p = 0.391), plasma ferritin (A vs B, p = 0.322), or in the incidence of iron deficiency (A vs B, p = 0.534). CONCLUSIONS: Iron fortified formulas containing between 0.5 and 0.9 mg/dl iron seem to meet the iron nutritional needs of preterm infants after hospital discharge.

Knee-heel length measurement in healthy preterm infants.

AIM: To examine the reproducibility of crown-heel length measurement; the precision and reproducibility of knee-heel length measurement; and the association between the two in healthy preterm infants. METHODS: Paired crown-heel and knee-heel lengths were measured on 172 occasions by three observers in 43 preterm infants between 205 and 458 days of postconceptional age. RESULTS: Crown-heel length (CHL) measurement was highly reproducible, with a coefficient of variation (CV) of 0.41%. Knee-heel length (KHL) measurement was relatively precise (CV 0.78%), but less reproducible (intra-observer CV 1.77%, intra-observer CV 2.11%), especially in larger infants. The association between KHL and CHL was not consistent and varied with age. KHL was a poor predictor of CHL, with a 95% predictive interval of +/- 27.5 mm. CONCLUSIONS: KHL was less reproducible than CHL, especially in larger infants, and a poor predictor of CHL.

Body composition of preterm infants during infancy.

AIMS: To examine body composition in preterm infants. METHODS: Body composition was measured by dual energy x-ray absorptiometry (DEXA) at hospital discharge, term, 12 weeks, and at 6 and 12 months corrected age in 125 infants (birthweight < or = 1750 g, gestational age < or = 34 weeks). RESULTS: Body weight derived by DEXA accurately predicted that determined by conventional scales. In both sexes lean mass (LM), fat mass (FM), %FM, bone area (BA), bone mineral mass (BMM), and bone mineral density (BMD) increased rapidly during the study; significant changes were detectable between discharge and term. At 12 months, LM, BA, and BMM, but not FM, %FM, or BMD were greater in boys than in girls. Corrected for age, LM was less than those of the reference term infant; FM and %FM were similar; BMM was greater. Corrected for weight, LM was similar to those of the reference infant, while the FM and %FM of study infants were slightly greater. CONCLUSIONS: DEXA accurately measures body mass. Body composition in preterm boys and girls differs. Interpretation of DEXA values may depend on whether age or body weight are regarded as the appropriate reference.

Feeding preterm infants after hospital discharge: effect of dietary manipulation on nutrient intake and growth.

The objective of this study was to compare formula intake, the time of weaning, and growth in preterm infants (< or = 1750-g birth weight, < or = 34-wk gestation) fed a standard term or preterm infant formula after initial hospital discharge. Infants were randomized at hospital discharge to be fed a preterm infant formula from discharge to 6 mo corrected age (group A), a term formula from discharge to 6 mo (group B), or the preterm formula (discharge to term) and the term formula (term to 6 mo (group C). Infants were seen biweekly (discharge to term) and monthly (term to 6 mo), when intake was measured and anthropometry and blood sampling were performed. The results were analyzed using ANOVA. Although nutrient intake was similar, at 6 mo girls were lighter (6829 versus 7280 g) and shorter (64.4 versus 66.0 cm) than boys (p < 0.05). Patient characteristics were similar between the treatment groups. Although the volume of intake differed (B > C > A; p < 0.001), energy intake was similar in the groups. Because of differences in formula composition, protein, calcium, and phosphorus intakes differed (B < C < A; p < 0.001). Lower protein intakes were related to lower blood urea nitrogen levels (B < C < A; p < 0.001). At 6 mo, infant boys in B and C were lighter (6933, 6660 < 7949 g), shorter (65.3, 64.9 < 67.1 cm), and had a smaller head circumference (43.7, 43.7 < 44.8 cm; p < 0.05) than infants in group A. Preterm infants were found to increase their volume of intake to compensate for differences in energy density between formulas. After hospital discharge, infant boys fed a preterm formula grew faster than infant girls fed a preterm formula or infant boys fed a term formula.