The effects of prepartum energy intake and peripartum rumen-protected choline supplementation on hepatic genes involved in glucose and lipid metabolism

Nutritional interventions, either by controlling dietary energy (DE) or supplementing rumen-protected choline (RPC) or both, may mitigate negative postpartum metabolic health outcomes. A companion paper previously reported the effects of DE density and RPC supplementation on production and health outcomes. The objective of this study was to examine the effects of DE and RPC supplementation on the expression of hepatic oxidative, gluconeogenic, and lipid transport genes during the periparturient period. At 47 ± 6 d relative to calving (DRTC), 93 multiparous Holstein cows were randomly assigned in groups to dietary treatments in a 2 × 2 factorial of (1) excess energy (EXE) without RPC supplementation (1.63 Mcal of NE_L/kg of dry matter; EXE-RPC); (2) maintenance energy (MNE) without RPC supplementation (1.40 Mcal of NE_L/kg dry matter; MNE-RPC); (3) EXE with RPC supplementation (EXE+RPC); and (4) MNE with RPC supplementation (MNE+RPC). To achieve the objective of this research, liver biopsy samples were collected at -14, +7, +14, and +21 DRTC and analyzed for mRNA expression (n = 16/treatment). The interaction of DE × RPC decreased glucose-6-phosphatase and increased peroxisome proliferator-activated receptor α in MNE+RPC cows. Expression of cytosolic phosphoenolpyruvate carboxykinase was altered by the interaction of dietary treatments with reduced expression in EXE+RPC cows. A dietary treatment interaction was detected for expression of pyruvate carboxylase although means were not separated. Dietary treatment interactions did not alter expression of carnitine palmitoyltransferase 1A or microsomal triglyceride transfer protein. The 3-way interaction of DE × RPC × DRTC affected expression of carnitine palmitoyltransferase 1A, glucose-6-phosphatase, and peroxisome proliferator-activated receptor α and tended to affect cytosolic phosphoenolpyruvate carboxykinase. Despite previously reported independent effects of DE and RPC on production variables, treatments interacted to influence hepatic metabolism through altered gene expression.

Timing of initiation and duration of feeding rumen-protected choline affects performance of lactating Holstein cows

Objectives were to evaluate the effects of altering timing of initiating and duration of supplementing rumen-protected choline (RPC) on lactation performance in dairy cows. The hypothesis was that RPC increases yields of milk and milk components, regardless of when supplementation is initiated, and that the effects of supplementing RPC starting prepartum and continuing post-transition would be additive. Cows at 241 ± 2.2 d of gestation were blocked by parity group (49 entering lactation 2, 50 entering lactation >2) and 305-d milk yield and, within block, assigned randomly to 1 of 4 treatments arranged as a 2 × 2 factorial with 2 levels of choline in transition, from 21 d pre- to 21 d postpartum, and 2 levels of choline in post-transition, from 22 to 105 d postpartum. The 2 levels of RPC supplemented were either 0 g/d or 12.9 g/d of choline ion fed as 60 g/d of an RPC product that was top-dressed onto the total mixed ration. Thus, treatments were as follows: NN (n = 25): no choline in transition or post-transition; NC (n = 25): no choline in transition and choline in post-transition; CN (n = 25): choline in transition and no choline in post-transition; CC (n = 24): choline in transition and in post-transition. Prepartum, treatments were supplemented (mean ± SD) for the last 18.8 ± 5.7 and 19.2 ± 5.0 d of gestation in treatments with 0 or 12.9 g/d of choline ion, respectively. Supplementing RPC prepartum did not affect dry matter intake (DMI), body weight (BW), or body condition score (BCS) in the last 3 weeks of gestation. Likewise, RPC did not affect the yield or the composition of colostrum. Supplementation with RPC during transition increased fat percent by 0.02 percentage units, fat yield by 0.16 kg/d, and energy-corrected milk (ECM) by 3.1 kg/d in the first 21 d postpartum, and increased fat yield by 0.10 kg/d and ECM by 2.4 kg/d from 22 to 105 d postpartum. Supplementing RPC during transition did not affect DMI postpartum, but it improved feed efficiency, and cows produced 0.11 kg/d more ECM per kg of DMI. Changes in BW and BCS during the first 21 d postpartum did not differ between treatments. Cows fed RPC during transition had more negative net energy balance and 0.1 unit smaller BCS in the first 105 d postpartum than non-supplemented cows. Supplementing RPC in post-transition did not influence productive performance in dairy cows, and choline supplementation during transition or post-transition did not affect measures of reproduction. Collectively, supplementing RPC to supply 12.9 g/d of choline ion benefited productive performance in dairy cows when supplementation occurred during the transition period, but no additional benefit was observed from supplementing RPC past 22 d postpartum.

Effect of prepartum energy intake and supplementation with ruminally protected choline on innate and adaptive immunity of multiparous Holstein cows

Objectives were to evaluate the effect of prepartum energy intake and peripartal supplementation of ruminally protected choline (RPC) on select indicators of immune status in blood plasma and on lipopolysaccharide-stimulated blood cells ex vivo. At 47 ± 6 d before the expected calving date, 93 multiparous Holstein cows were assigned randomly to 1 of 4 dietary treatments in a 2 × 2 factorial arrangement. Cows were fed energy to excess [EXE; 1.63 Mcal of net energy for lactation (NE_L)/kg of dietary dry matter (DM)] or to maintenance (MNE; 1.40 Mcal of NE_L/kg of dietary DM) ad libitum throughout the nonlactating period. The RPC was fed at 0 or 60 g/d to supply 0 or 12.9 g/d of choline ions top-dressed for 17 ± 4.6 d prepartum through 21 d postpartum. After calving, cows were fed the same methionine-supplemented diet, apart from RPC supplementation. During the last 2 wk before calving and during the first 5 wk postpartum, blood was sampled repeatedly and analyzed for cell types, acute-phase proteins, tumor necrosis factor-α (TNFα), and neutrophil function. Samples of whole blood were collected at 3 and 14 DIM and stimulated with 1 μg/mL lipopolysaccharide (LPS) in vitro for 6 and 24 h. After 6 h of LPS exposure, peripheral blood leucocytes (PBL) were harvested, and relative transcript abundance for select cytokines were measured. Supernatant was analyzed for TNFα after 24 h of LPS exposure. The PBL from cows fed EXE diets during the whole dry period had increased transcripts for the proinflammatory cytokines CXCL8 and TNF, although the plasma concentrations of the acute-phase proteins haptoglobin and fibrinogen, and the killing activity of the blood neutrophils in the postpartum period, were not affected by feeding different energy levels prepartum. Feeding RPC to cows overfed energy prepartum modulated their inflammatory state, as evidenced by decreased IL6 in PBL and reduced mean fluorescence intensity of CD14 during the postpartum period, compared with cows not fed RPC. Feeding RPC also decreased TNFα protein production, abundances of IL1B, CXCL8, and TNF transcripts, and mean fluorescence intensity of CD80 of PBL stimulated by LPS, regardless of prepartum energy intake. In contrast, proportions of blood neutrophils undergoing phagocytosis and oxidative burst were increased at 17 d postpartum in cows supplemented with RPC. Collectively, these data indicate that transition cows supplemented with RPC experienced less inflammation, which may partially explain increased milk production in cows supplemented with RPC.

Responses to rumen-protected choline in transition cows do not depend on prepartum body condition

It is often suggested that the benefits of supplemental rumen-protected choline (RPC) might be greater in cows predisposed to fatty liver, such as those that are overconditioned; however, limited data support this suggestion. Therefore, the hypothesis of this study was that responses to supplementing RPC to transition dairy cows is not dependent on the degree of fatness prepartum. Objectives were to evaluate the effects of supplementing RPC to transition dairy cows according to body condition score (BCS) prepartum on production and metabolic responses. Data from 2 randomized block experiments that evaluated the effects of RPC supplementation during the transition period were combined. Within each experiment, cows were assigned randomly to receive 0 (CTRL) or 12.9 g/d choline ion in an RPC form (CHOL) daily top-dressed onto the diet from 21 d prepartum to 21 d postpartum. Body condition was evaluated twice prepartum before enrollment and the mean value was used as an explanatory variable for statistical analyses. Data were collected for the last 21 d of gestation and the first 105 d postpartum. The BCS (mean ± standard deviation) prepartum were 3.51 ± 0.29 and 3.51 ± 0.32 for CTRL and CHOL, respectively, and ranged from 2.69 to 4.25. A total of 215 cows were enrolled in the respective experiments and contributed data for the incidence of diseases, whereas 192 cows contributed data for analyses of production responses, plasma metabolites, and liver composition. Irrespective of BCS, supplementing transition diets with CHOL increased yields of milk by 1.8 kg/d, fat by 0.08 kg/d, lactose by 0.08 kg/d, true protein by 0.04 kg/d, energy-corrected milk (ECM) by 1.9 kg/d, and fat-corrected milk by 2.1 kg/d. The improvements in productive performance were not followed by increased dry matter intake or measures of lipomobilization. Therefore, CHOL cows were more efficient in converting dry matter intake into ECM. Feeding CHOL increased concentration of hepatic triacylglycerol (CTRL = 3.23 vs. CHOL = 3.87% wet basis) in the first 21 d postpartum. Overconditioned cows were more prone to having exacerbated lipomobilization and increased prevalence and incidence of fatty liver, but no interactions between treatment and BCS were observed for body weight, BCS, or concentrations of metabolites in plasma or hepatic triacylglycerol. Treatment did not affect incidence of clinical diseases. Opposite to common suggestions, cows with increased hepatic triacylglycerol content also had increased yields of milk and ECM in the first 105 d postpartum. Collectively, these findings indicate that the effects of RPC supplementation during the transition period are independent of the degree of fatness of dairy cows prepartum. The findings also suggest that the effects on productive performance are not necessarily mediated by improvements in markers of metabolic health or reductions in hepatic triacylglycerol.

Effects of rumen-protected choline on the inflammatory and metabolic status and health of dairy cows during the transition period

The objectives of this study were to evaluate the effects of rumen-protected choline (RPC) supplementation from 21 d pre- to 21 d postpartum on markers of metabolic status and inflammatory response, concentrations of liposoluble vitamins, and plasma total Ca in parous Holstein cows. The hypotheses were that supplementing RPC during the transition period would reduce hepatic triacylglycerol accumulation postpartum and attenuate markers of inflammatory response following parturition, and collectively, such responses were expected to benefit health of dairy cows. Parous cows at 241 d of gestation were blocked by parity group and 305-d milk yield, and within block, they were assigned randomly to receive either 0 g/d [no choline in transition (NT), n = 55] or 12.9 g/d choline ion [choline in transition (CT), n = 58] from 21 d pre- to 21 postpartum. The RPC product was individually top-dressed onto the total mixed ration once daily. Prepartum, treatments were supplemented (mean ± standard deviation) for the last 18.8 ± 5.7 and 19.2 ± 5.0 d of gestation in NT and CT, respectively. Supplementing RPC prepartum did not affect concentrations of plasma metabolites and inflammatory markers during the last 3 wk of gestation. Postpartum, cows fed RPC had greater hepatic concentration of hepatic triacylglycerol (NT = 3.4 vs. CT = 4.4%) and tended to have increased concentration of β-hydroxybutyrate (NT = 0.48 vs. CT = 0.53 mM) in plasma. In spite of the increased hepatic triacylglycerol in cows fed RPC, treatment did not affect the concentrations of the inflammatory marker tumor necrosis factor-α or of the positive acute phase proteins, haptoglobin and fibrinogen. Supplementing choline tended to increase the concentration of plasma triacylglycerol by 0.69 mg/dL in the first 21 d postpartum and reduced the incidence of subclinical hypocalcemia by 20.9 percentage units compared with NT. Supplementing transition cows with RPC did not affect the concentrations of liposoluble vitamins in the first 7 d postpartum or the incidence of individual diseases or morbidity in early lactation. The inability of supplemental choline to reduce hepatic triacylglycerol might have been a consequence of the increased productive performance without additional dry matter intake.

Assessing bioavailability of ruminally protected methionine and lysine prototypes

Met and Lys are essential AA that can limit lactational performance in dairy cattle fed protein-sufficient diets. Thus, there is industry demand for ruminally protected (RP) sources of Met and Lys. One method of providing ruminal protection for Met and Lys is lipid encapsulation. The objective of this work was to assess 3 lipid-encapsulated Met prototypes (P1, P2, and P3) and 1 Lys prototype (P4) to determine ruminal protection, small intestine absorption (experiment 1), and animal production responses (experiment 2). Ruminal protection was estimated from 8-h in situ retention during ruminal incubation and intestinal absorption from plasma appearance after an abomasal bolus of the in situ retentate. Blood samples were collected over time to determine plasma Met and Lys concentration responses compared with unprotected Lys and Met infused abomasally. The prototypes were not exposed to the total diet or subjected to typical feed handling methods before evaluation. The bioavailability of P1, P2, and P3 Met prototypes was found to be 14, 21, and 18% of the initial AA material, respectively. The RP-Lys prototype had a bioavailability of 45%. To evaluate production responses, 20 Holstein cows were randomly assigned to 2 trials (n = 10 each) in a replicated Latin square design with 14-d periods. The base diet was predicted to be deficient in metabolizable Met (-14.8 g/d) and Lys (-16.1 g/d) per the Cornell Net Carbohydrate and Protein System (version 6.55). In the Met trial, the base diet was supplemented with RP-Lys to meet Lys requirements, and treatments were as follows: no added RP-Met (NCM), NCM plus Smartamine M (SM; Adisseo, Alpharetta, GA), and NCM plus P1, P2, or P3 at 148% of the Met content of SM. In the Lys trial, the base diet was supplemented with RP-Met to meet the Met requirement, and treatments were as follows: no added Lys (NCL), NCL plus AjiProL (AL; Ajinomoto Heartland Inc., Chicago, IL), and NCL plus P4 at 55, 78, or 102% of the reported absorbed Lys in AL. All products were top dressed on the diet without prior mixing or extended exposure to the rest of the diet. Milk protein concentration significantly increased when diets were supplemented with P2, P3, or SM (3.12, 3.12, and 3.11%, respectively) compared with NCM (3.02%). Only P1 (3.04%) was significantly lower than SM. Prototype P2 had the greatest numerical milk protein output response among the 3 RP-Met prototypes, suggesting that it may have had the greatest efficacy when supplemented into these rations. There was a numerical milk protein concentration response to AL and a linear increase in milk protein concentration for P4. The P4 and AL treatments resulted in comparable milk protein production regardless of P4 dose.

Is low iodine a risk factor for cardiovascular disease in Americans without thyroid dysfunction? Findings from NHANES

BACKGROUND AND AIMS

Low body iodine levels are associated with cardiovascular disease, in part through alterations in thyroid function. While this association suggested from animal studies, it lacks supportive evidence in humans. This study examined the association between urine iodine levels and presence of coronary artery disease (CAD) and stroke in adults without thyroid dysfunction.

METHODS AND RESULTS

This cross-sectional study included 2440 adults (representing a weighted n = 91,713,183) aged ≥40 years without thyroid dysfunction in the nationally-representative 2007-2012 National Health and Nutrition Examination Survey. The age and sex-adjusted urine iodine/creatinine ratio (aICR) was categorized into low (aICR<116 μg/day), medium (116 μg/day ≤ aICR < 370μg/day), and high (aICR ≥ 370μg/day) based on lowest/highest quintiles. Stroke and CAD were from self-reported physician diagnoses. We examined the association between low urine aICR and CAD or stroke using multivariable logistic regression modeling. The mean age of this population was 56.0 years, 47% were women, and three quarters were non-Hispanic whites. Compared with high urine iodine levels, multivariable adjusted odds ratios aOR (95% confidence intervals) for CAD were statistically significant for low, aOR = 1.97 (1.08-3.59), but not medium, aOR = 1.26 (0.75-2.13) urine iodine levels. There was no association between stroke and low, aOR = 1.12 (0.52-2.44) or medium, aOR = 1.48 (0.88-2.48) urine iodine levels.

CONCLUSION

The association between low urine iodine levels and CAD should be confirmed in a prospective study with serial measures of urine iodine. If low iodine levels precede CAD, then this potential and modifiable new CAD risk factor might have therapeutic implications.

WITHDRAWN: Profiles in Comparative Endocrinology: Carl B. Schreck Howard Bern Lecturer, Annual Meeting of Society of Integrative and Comparative Endocrinology, Seattle, January 5, 2010

This article has been withdrawn at the request of the editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Morphine analgesia and gastrointestinal morbidity in preterm infants: secondary results from the NEOPAIN trial

OBJECTIVE

To investigate the influence of morphine therapy and other factors on the attainment of full enteral feeds and on acquired gastrointestinal pathology in preterm infants.

DESIGN

Secondary data analysis from a randomised, placebo controlled trial.

SETTING

16 neonatal intensive care units in USA, Sweden, France and UK.

PATIENTS

898 infants (treatment group 449, control 449). Gestation (median (range)): 27 (23-32) weeks; birth weight (median (range)): 985 (420-2440) g.

INTERVENTIONS

Morphine (M) or placebo (Pl) given pre-emptively by intravenous loading dose (100 microg/kg of morphine) and infusion (10-30 microg/kg/h depending on gestation) while infants were ventilated, for up to 14 days. "Open-label" morphine (A) could be given if clinically indicated.

MAIN OUTCOME MEASURES

Age at full enteral feeds and major acquired gastrointestinal pathology.

RESULTS

The group randomised to morphine was later in attaining full feeds (median days (quartiles): M 20 (13-29), Pl 17 (12-26); p = 0.003), and in starting feeds (median days (quartiles): M 5 (3-8), Pl 4 (2-7)). In a linear regression model, age at full feeds was independently associated with birth weight, a score of neonatal morbidities, neonatal dexamethasone use and cumulative morphine dose. There was no relationship between morphine use and acquired gastrointestinal pathology (M 9/449, Pl 8/449; chi2 p = 0.81).

CONCLUSIONS

Morphine delays the attainment of full enteral feeds, partly by delaying the start of feeding, but does not discernibly increase gastrointestinal complications. The attainment of full feeds is influenced by morphine dose, but other factors seem to be important, including birth weight and neonatal morbidity.

Morphine pharmacokinetics and pharmacodynamics in preterm and term neonates: secondary results from the NEOPAIN trial

BACKGROUND

Relationships between plasma morphine concentrations and neonatal responses to endotracheal tube (ETT) suctioning are unknown in preterm neonates.

METHODS

Ventilated preterm neonates (n=898) from 16 centres were randomly assigned to placebo (n=449) or morphine (n=449). After an i.v. loading dose (100 microg kg(-1)), morphine infusions [23-26 weeks postmenstrual age (PMA) 10 microg kg(-1) h(-1); 27-29 weeks 20 microg kg(-1) h(-1); and 30-32 weeks 30 microg kg(-1) h(-1)] were established for a maximum of 14 days. Open-label morphine (20-100 microg kg(-1)) was given for pain or agitation. Morphine assay and neonatal response to ETT suctioning was measured at 20-28 and 70-76 h after starting the drug infusion and at 10-14 h after discontinuation of the study drug. The concentration-effect response was investigated using non-linear mixed effects models.

RESULTS

A total of 5119 data points (1598 measured morphine concentrations and 3521 effect measures) were available from 875 neonates for analysis. Clearance was 50% that of the mature value at 54.2 weeks PMA (CLmat(50)) and increased from 2.05 litre h(-1) 70 kg(-1) at 24 weeks PMA to 6.04 litre h(-1) 70 kg(-1) at 32 weeks PMA. The volume of distribution in preterm neonates was 190 litre 70 kg(-1) (CV 51%) and did not change with age. There was no relationship between morphine concentrations (range 0-440 microg litre(-1)) and heart rate changes associated with ETT suctioning or with the Premature Infant Pain Profile.

CONCLUSIONS

A sigmoid curve describing maturation of morphine clearance is moved to the right in preterm neonates and volume of distribution is increased compared with term neonates. Morphine does not alter the neonatal response to ETT suctioning.

Impact of timing of pubertal maturation on growth in black and white female adolescents: The National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVES

To evaluate the impact of early, mid-onset, and late maturation, as assessed by timing of menarche, on height, height velocity, weight, body mass index, and sum of skinfolds in a group of white and black girls.

STUDY DESIGN

The Growth and Health Study recruited 9- and 10-year-old girls from Richmond, California, Cincinnati, Ohio, and Washington, DC. There were 616 white and 539 black participants recruited at age 9 and 550 white and 674 black participants recruited at age 10. Participants were seen annually for 10 visits. Longitudinal regression models were used to test for differences in each growth measure by timing of menarche across all ages and to determine whether these differences change with age.

RESULTS

Mean age at menarche among white participants was 12.7 years, and among black participants, 12.0 years. According to race-specific 20th and 80th percentiles, early maturers were tallest at early ages and shortest after adult stature had been attained. Peak height velocity and post-menarche increment in stature were greatest in early maturers and least in late maturers. Weight was greatest in early and least in late maturers, as was body mass index. Sum of skinfolds was also greatest in early and least in late maturers. There was no impact of timing of maturation on two common measures of regional fat distribution.

CONCLUSIONS

Girls who matured early were shorter in early adulthood, despite having greater peak height velocity and post-menarchal increment in height. Throughout puberty, early maturers had greater ponderosity and adiposity, although there was no association with regional distribution of fat.

Racial differences in the sums of skinfolds and percentage of body fat estimated from impedance in black and white girls, 9 to 19 years of age: the National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVES

This National Heart, Lung, and Blood Institute Growth and Health Study report assesses racial differences in fat patterning in black and white girls ages 9 to 19 years, comparing the sum of triceps and subscapular skinfolds (SSFs) and percentage of body fat (%BF) from impedance as two indices of adiposity. It is hypothesized that racial differences in fat patterning manifest during puberty.

RESEARCH METHODS AND PROCEDURES

SSF and %BF were measured annually. Racial differences in SSF and %BF were evaluated by age. Associations between %BF and SSF were evaluated using the Pearson's correlations coefficient. Classification agreement was evaluated using the kappa-statistic. Effects of pubertal stage and race on classification agreement were examined using multivariate models.

RESULTS

White girls had a greater mean %BF at 9 to 12 years of age; black girls had a greater %BF thereafter. Black girls had a greater mean SSF at every age. The correlation coefficient between SSF and %BF was 0.79, and there was good agreement between %BF and SSF in separating high (>85th percentile) from not high (kappa = 0.60 for whites and 0.66 for blacks). SSF associated more with %BF in prepuberty and early puberty than in late puberty.

DISCUSSION

Despite good correlations between %BF and SSF, the two methods indicate different fat patterns in black and white girls.

Racial divergence in adiposity during adolescence: The NHLBI Growth and Health Study

BACKGROUND

Black women are particularly vulnerable to obesity, with a prevalence rate of >50%. The higher mortality and morbidity from cardiovascular disease, stroke, and diabetes have been attributed, in part, to their obesity. In recent years, a particular public health concern is the increasing secular trend in obesity with an even greater racial disparity, especially in girls and women. Between the early 1960s and late 1980s, the prevalence of obesity tripled in young black girls 6 to 11 years of age, while it doubled in white girls. Similarly, both overweight and obesity in adolescent girls 12 to 17 years of age also increased, with a greater increase again seen in adolescent black girls. This secular trend in obesity with a greater increase in black girls signals a potentially grave future chronic disease burden on black women, which is already higher than in white women. The increasing occurrence in children and adolescents of noninsulin-dependent diabetes, traditionally viewed as an adult-onset condition, may be a consequence of the currently high prevalence of obesity in American youth. Not surprisingly, this condition is seen more frequently among black youths. Prepubescent black girls are generally leaner than age-comparable white girls, but by 20 years of age, black women are considerably heavier than are white women. Thus, it is assumed that the racial disparity in adiposity evolves during adolescence. However, the specific age at which this occurs and underlying factors are yet to be identified because of the current paucity of longitudinal cohort data.

OBJECTIVES

In 1985, the National Heart, Lung, and Blood Institute (NHLBI) initiated a 10-year longitudinal multicenter study (the NHLBI Growth and Health Study [NGHS]) to investigate the development of obesity in black and white girls during adolescence and its environmental, psychosocial, and cardiovascular disease risk factor correlates. The purpose of this report is to examine the natural history of adiposity and weight accretion during adolescence in a biracial cohort of girls to investigate the evolution of the racial divergence in adiposity and to examine the relationships between increases in adiposity and pubertal maturation, energy intake, and physical activity.

PARTICIPANTS AND SETTING

A total of 2379 black (51%) and white (49%) girls, 9 to 10 years of age, were recruited from public and parochial schools in Richmond, California, and Cincinnati, Ohio, and from families enrolled in a large health maintenance organization in the Washington, DC area. Participant eligibility was limited to girls and their parents who declared themselves as being either black or white and who lived in racially concordant households. DESIGN AND STATISTICAL ANALYSIS: The NGHS is a multicenter prospective study of black and white girls with annual visits from 9 to 10 years of age through 18 to 19 years of age. The follow-up rate was 89% at the 10th annual visit. Skinfold measurements were obtained at the triceps, suprailiac, and subscapular sites with Holtain calipers. Sexual maturation was assessed by trained registered nurses. The onset of menarche was ascertained annually by questionnaire. All clinical assessments were conducted using a common protocol by centrally trained staff. Longitudinal regression (generalized estimating equations) models were used to examine the relationship between adiposity and race, age, pubertal maturation, daily energy intake, and physical activity.

MAIN OUTCOME MEASURES

The main outcome measure was the sum of skinfolds (SSF) at the triceps, subscapular, and suprailiac sites as an index of adiposity for comparison between the 2 racial groups. Body mass index (BMI; weight in kilograms divided by height in meters, squared) distributions were examined by age and race.

RESULTS

Racial differences in SSF, unadjusted for maturation, were evident at 10 years of age. For each chronological age, there was a higher proportion of black girls with more advanced pubertal maturation than white girls. The 15th percentiles for SSF were similar and remained thus throughout the study. The median for SSF for black girls, although similar to the median SSF of white girls at 9 years of age, became greater for black girls at 12 years of age (36 mm vs 32.5 mm) and at age 19 years the difference was 6 mm (49.5 mm vs 43.5 mm). In contrast, the difference in the 85th as well as the 95th percentile values for SSF were substantially higher in black girls at all ages (9 mm and 10 mm, or 18% and 15%, respectively, at age 9 years) and these racial differences widened with age (20 mm and 26 mm, or 25% and 24%, respectively, by age 19 years). The racial difference in the median BMI increased from 0.4 to 2.3 kg/m(2) between ages 9 and 19 years. Unlike SSF at the 15th percentile, the BMI for lean 9-year-old black girls was ~3% higher than whites. (ABSTRACT TRUNCATED)

Long-term safety and efficacy of a cholesterol-lowering diet in children with elevated low-density lipoprotein cholesterol: seven-year results of the Dietary Intervention Study in Children (DISC)

OBJECTIVE

Diets reduced in fat and cholesterol are recommended for children over 2 years of age, yet long-term safety and efficacy are unknown. This study tests the long-term efficacy and safety of a cholesterol-lowering dietary intervention in children.

METHODS

Six hundred sixty-three children 8 to 10 years of age with elevated low-density lipoprotein cholesterol (LDL-C) were randomized to a dietary intervention or usual care group, with a mean of 7.4 years' follow-up. The dietary behavioral intervention promoted adherence to a diet with 28% of energy from total fat, <8% from saturated fat, up to 9% from polyunsaturated fat, and <75 mg/1000 kcal cholesterol per day. Serum LDL-C, height, and serum ferritin were primary efficacy and safety outcomes.

RESULTS

Reductions in dietary total fat, saturated fat, and cholesterol were greater in the intervention than in the usual care group throughout the intervention period. At 1 year, 3 years, and at the last visit, the intervention compared with the usual care group had 4.8 mg/dL (.13 mmol/L), 3.3 mg/dL (.09 mmol/L), and 2.0 mg/dL (.05 mmol/L) lower LDL-C, respectively. There were no differences at any data collection point in height or serum ferritin or any differences in an adverse direction in red blood cell folate, serum retinol and zinc, sexual maturation, or body mass index.

CONCLUSION

Dietary fat modification can be achieved and safely sustained in actively growing children with elevated LDL-C, and elevated LDL-C levels can be improved significantly up to 3 years. Changes in the usual care group's diet suggest that pediatric practices and societal and environmental forces are having positive public health effects on dietary behavior during adolescence.

Gastroenteropancreatic hormones (insulin, glucagon, somatostatin, and multiple forms of PYY) from the pallid sturgeon, Scaphirhynchus albus (Acipenseriformes)

Insulin, glucagon, somatostatin-14, and three structurally related molecular forms of peptide tyrosine-tyrosine (PYY) were isolated from an extract of the combined pancreas and gastrointestinal tract of the pallid sturgeon, Scaphirhynchus albus. Pallid sturgeon insulin was identical to insulin from the Russian sturgeon, Acipenser guldenstaedti, and to insulin-2 from the paddlefish, Polyodon spathula, and was approximately twofold less potent than human insulin in inhibiting the binding of [3-[(125)I] iodotyrosine-A14] human insulin to the soluble human insulin receptor. The sturgeon glucagon (HSQGMFTNDY(10)-SKYLEEKLAQ(20) EFVEWLKNGK(30)S), like the two paddlefish glucagons, contains 31 rather than 29 amino acid residues, indicative of an anomalous pathway of posttranslational processing of proglucagon. Pallid sturgeon somatostatin, identical to human somatostatin-14, was also isolated in a second molecular form containing an oxidized tryptophan residue, but [Pro(2)]somatostatin-14, previously isolated from the pituitary of A. guldenstaedti, was not identified. Sturgeon PYY (FPPKPEHPGD(10)DAPAEDVAKY(20)YTALRHYINL(30) ITRQRY.HN(2)) was also isolated in variant forms containing the substitutions (Phe(1) --> Ala) and (Ala(18) --> Val), indicative of at least two gene duplications occurring within the Acipenseriformes lineage. The amino acid sequences of the pallidsturgeon PYY peptides are appreciably different from the proposed "ancestral" PYY sequence that has otherwise been very strongly conserved among the actinopterygian and elasmobranch fish.

Efficacy and safety of lowering dietary intake of total fat, saturated fat, and cholesterol in children with elevated LDL cholesterol: the Dietary Intervention Study in Children

BACKGROUND

Few studies have shown the efficacy and safety of lower-fat diets in children.

OBJECTIVE

Our objective was to assess the efficacy and safety of lowering dietary intake of total fat, saturated fat, and cholesterol to decrease LDL-cholesterol concentrations in children.

DESIGN

A 6-center, randomized controlled clinical trial was carried out in 663 children aged 8-10 y with LDL-cholesterol concentrations greater than the 80th and less than the 98th percentiles for age and sex. The children were randomly assigned to either an intervention group or a usual care group. Behavioral intervention promoted adherence to a diet providing 28% of energy from total fat, <8% from saturated fat, </=9% from polyunsaturated fat, and <0.018 mg cholesterol*kJ(-)(1)*d(-)(1) (not to exceed 150 mg/d). The primary efficacy measure was mean LDL cholesterol and the safety measures were mean height and serum ferritin concentration at 3 y.

RESULTS

At 3 y, dietary total fat, saturated fat, and cholesterol were lower in the intervention group than in the usual care group (all P: < 0. 001). LDL cholesterol decreased in the intervention and usual care groups by 0.40 mmol/L (15.4 mg/dL) and 0.31 mmol/L (11.9 mg/dL), respectively. With adjustment for baseline concentration, sex, and missing data, the mean difference between groups was -0.08 mmol/L (95% CI: -0.15, -0.01), or -3.23 mg/dL (95% CI: -5.6, -0.5) (P: = 0. 016). There were no significant differences between groups in adjusted mean height or serum ferritin.

CONCLUSION

Dietary changes are effective in achieving modest lowering of LDL cholesterol over 3 y while maintaining adequate growth, iron stores, nutritional adequacy, and psychological well-being during the critical growth period of adolescence.

Longitudinal changes in physical activity in a biracial cohort during adolescence

PURPOSE

This report describes the development and use of two self-report methods and an objective measure to assess longitudinal changes in physical activity in a large biethnic cohort of young girls from childhood through adolescence.

METHODS

The NHLBI Growth and Health Study (NGHS) is a multicenter study of obesity development in 2379 black and white girls followed from ages 9-10 yr to 18-19 yr (NGHS years 1-10). A Caltrac activity monitor was used to objectively quantify activity levels in years 3-5. A 3-d diary (AD) and a habitual patterns questionnaire (HAQ) were administered annually and biannually, respectively, to subjectively quantify physical activity levels. The changing pattern of activities as the girls matured during the 10-yr study period necessitated periodic form changes. Empirical analytic approaches were developed to help distinguish between true longitudinal changes in activity levels from potential numerical artifacts resulting from modifications in forms.

RESULTS

The longitudinal activity data indicate a steep decline in the level of reported activity from baseline to year 10 as indicated by AD scores (446.8 to 292.1 MET-min x d(-1), 35%) as well as by HAQ scores (29.3 to 4.9 MET-times x wk(-1), 83%). This parallel trend in the pattern of the decline in activity among the two self-report methods was mirrored by a similar decline using the Caltrac method of physical activity assessment. From years 3 to 5, the AD decreased by 22%, whereas both the HAQ and Caltrac declined by 21%.

CONCLUSION

The longitudinal data on physical activity collected in the NGHS cohort further confirm a dramatic decrease in the overall level of physical activity during the transition from childhood to adolescence. The consistency among the three methods indicate that both the AD and HAQ are useful tools for the assessment of activity levels in adolescent girls.

Juvenile pallid (Scaphirhynchus albus) and hybrid pallidxshovelnose (S. albusxplatorynchus) sturgeons exhibit low physiological responses to acute handling and severe confinement

Following a 7.5-h transport haul, juvenile pallid sturgeon (Scaphirhynchus albus) showed a small but significant increase in plasma cortisol to 4.7 ng ml(-1) but similar increases did not occur after fish were handled in a net held in the air for 30 s. Subsequent experiments on yearling pallid sturgeon and hybrid pallidxshovelnose (S. albusxplatorynchus) sturgeon using the same 30-s handling stressor failed to evoke increases in plasma cortisol, lactate or glucose. Plasma cortisol increased significantly from about 2 to 13-14 ng ml(-1) in both pallid and hybrid sturgeon during a 6-h severe confinement stressor with handling. Plasma cortisol in 2-year-old pallid sturgeon subjected to the same stressor demonstrated a linear pattern of increase during the initial 1 h. Plasma lactate increased from 1.11 to about 2.11 mmol l(-1) in hybrid sturgeon during the first hour of severe confinement but did not change throughout the entire confinement period in pallid sturgeon. A significant increase in plasma cortisol to 5.4 ng ml(-1) in 2-year-old pallid sturgeon 1 h after being subjected to 30 s handling at 19:00 h but not at 07:00 or 13:00 h suggests that a small diurnal variation in their stress response may exist. Although both pallid and hybrid sturgeons were responsive to stress, they exhibited very low physiological responses compared with those following equivalent stressors in most teleostean fishes or another chondrostean, the paddlefish (Polyodon spathula). Reasons for the apparent low responses to handling and confinement in scaphirhynchid sturgeons are not known but may relate to their evolutionary history, neuroendocrine mechanisms involved in their corticosteroid responses, or anatomy of their interrenal tissue structure.

Tachykinins (substance P and neuropeptide gamma) from the brains of the pallid sturgeon, Scaphirhynchus albus and the paddlefish, Polyodon spathula (Acipenseriformes)

A peptide with substance P-like immunoreactivity was isolated from extracts of the brains of the pallid sturgeon, Scaphirhynchus albus and the North American paddlefish, Polyodon spathula. The primary structure of the peptide (Lys-Pro-Lys-Pro-His-Gln-Phe-Phe-Gly-Leu-Met.NH(2)) is the same in both species and contains 2 amino acid substitutions (Arg(1) --> Lys and Gln(5) --> His) compared with human substance P and 1 substitution (Arg(3) --> Lys) compared with substance P from the trout (Teleostei). Scyliorhinin I, a tachykinin previously isolated from an extract of sturgeon intestine, was not detected in either brain extract. A peptide with neurokinin A-like immunoreactivity (Ser-Ser-Ala-Asn-Arg-Gln-Ile-Thr-Gly-Lys(10)Arg-Gln-Lys-Ile-Asn-Ser-P he-Val-Gly-Leu(20)Met.NH(2)) was isolated from sturgeon brain and contains 10 amino acid substitutions compared with human neuropeptide gamma (a specific product of the posttranslational processing of gamma-preprotachykinin A) but only 4 substitutions compared with trout neuropeptide gamma. It was not possible to obtain the paddlefish neurokinin A-related peptide in pure form. The structural similarity between the sturgeon and the trout tachykinins supports the hypothesis that the Acipenseriformes (sturgeons and paddlefish) represent the sister group of the Neopterygii (gars, bowfin, and teleosts).

Overweight, fat patterning, and cardiovascular disease risk factors in black and white boys

PURPOSE

To evaluate the relationships of overweight and fat patterning with cardiovascular disease (CVD) risk factors in black and white boys.

DESIGN

Cross-sectional analysis of CVD risk factors by weight and central adiposity groups in black and white boys, aged 10 to 15 years. Mean adiposity, lipid, and blood pressure variables were compared between weight and central adiposity groups within race by using linear regression models. Observed clustering of risk factors within weight and adiposity groups was compared with the expected clustering under an assumption of no association.

RESULTS

Within each racial group, overweight boys had greater skinfolds, lower high-density lipoprotein cholesterol levels, higher low-density lipoprotein cholesterol and triglyceride levels, and higher systolic and diastolic blood pressure than non-overweight boys. Among overweight boys, greater central adiposity was associated with higher risk factor levels and increased clustering of risk factors.

CONCLUSION

Overweight and central adiposity together profoundly affect CVD risk factor levels and risk factor clustering in black and white boys.

Overweight, fat patterning, and cardiovascular disease risk factors in black and white girls: The National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVE

To determine the association of overweight and central adiposity with cardiovascular disease risk factors in black and white 9- and 10-year-old girls.

DESIGN

Cross-sectional analysis of baseline data collected from participants in the National Heart, Lung, and Blood Institute Growth and Health Study. Girls were classified as overweight or not with the use of the age- and sex-specific 85th percentiles of the body mass index (kilograms per square meter) distributions from the combined NHANES (I and II) data set. Mean indexes of central adiposity, blood pressure levels, and lipid concentrations and the clustering of risk factors based on published cut points were compared between weight groups by race and by central adiposity group within weight and race groups.

RESULTS

Overweight was associated with increased risk factor levels and with increased clustering in both black and white girls. Among overweight girls greater central adiposity was associated with higher risk factor levels and increased clustering.

CONCLUSIONS

Given the associations between cardiovascular disease risk factors and both overweight and central adiposity, the secular trends toward increased obesity in American youth portend a worsening of cardiovascular disease risk profiles.

Analgesia and sedation in preterm neonates who require ventilatory support: results from the NOPAIN trial. Neonatal Outcome and Prolonged Analgesia in Neonates

BACKGROUND

Preterm neonates are exposed to multiple painful procedures after birth and exhibit acute physiological responses to pain. Occurrence of early intraventricular hemorrhage within 24 to 72 hours after birth suggests a role of pain and stress in the multifactorial causation of severe intraventricular hemorrhage and periventricular leukomalacia. We proposed that such neurologic outcomes in preterm neonates who require ventilatory support may be reduced by morphine analgesia or midazolam sedation compared with a placebo.

OBJECTIVES

To define the incidence of clinical outcomes in the target study population, to estimate the effect size and adverse effects associated with analgesia and sedation, and to calculate the sample size for a definitive test of this hypothesis.

METHODS

Sixty-seven preterm neonates were randomized in a pilot clinical trial from 9 centers. Neonates of 24 to 32 weeks gestation were eligible if they had been intubated and required ventilatory support for less than 8 hours and if they were enrolled within 72 hours after birth. Exclusion criteria included major congenital anomalies, severe intrapartum asphyxia, and participation in other research studies. Severity of illness was assessed by the Clinical Risk Index for Babies, and neonates were randomized to receive continuous infusions of morphine sulfate, midazolam hydrochloride, or 10% dextrose (placebo). Masked study medications were continued as long as clinically necessary, then weaned and stopped according to predefined criteria. Levels of sedation (COMFORT scores) and responses to pain (Premature Infant Pain Profile scores) were measured before, during, and 12 hours after discontinuation of drug infusion. Cranial ultrasound examinations were performed as part of routine practice, and poor neurologic outcomes were defined as neonatal death, severe intraventricular hemorrhage (grade III or IV), or periventricular leukomalacia.

RESULTS

No significant differences occurred in the demographic, clinical, and socioeconomic variables related to mothers and neonates in the 3 groups or in the severity of illness at birth as measured by Clinical Risk Index for Babies scores. Two neonates in the placebo group and 1 neonate in the midazolam group died; no deaths occurred in the morphine group. Poor neurologic outcomes occurred in 24% of neonates in the placebo group, 32% in the midazolam group, and 4% in the morphine group (likelihood ratio chi2 = 7.04, P = .03). Secondary clinical outcomes and neurobehavioral outcomes at 36 weeks' postconceptional age were similar in the 3 groups. Responses elicited by endotracheal tube suction (Premature Infant Pain Profile scores) were significantly reduced during the morphine (P<.001) and midazolam (P = .002) infusions compared with the placebo group.

CONCLUSIONS

This pilot trial suggests that preemptive analgesia given by continuous low-dose morphine infusion may reduce the incidence of poor neurologic outcomes in preterm neonates who require ventilatory support. Limitations in the sample size of this pilot study suggest that these results should be confirmed in a large multicenter randomized trial.

Purification and characterization of galanin and scyliorhinin I from the hybrid sturgeon, Scaphirhynchus platorynchus x Scaphirhynchus albus (Acipenseriformes)

The sturgeons (order Acipenseriformes) are extant representatives of a group of ancient Actinopterygian (ray-finned) fish. Galanin and scyliorhinin I (a tachykinin with limited structural similarity to mammalian substance P) have been isolated from an extract of the gastrointestinal tract of a sturgeon (an F1 hybrid between the shovelnose sturgeon, Scaphirhynchus platorynchus, and the pallid sturgeon, Scaphirhynchus albus). The primary structure of sturgeon galanin (Gly-Trp-Thr-Leu-Asn-Ser-Ala-Gly-Tyr-Leu10-Leu-Gly-Pro-His-Ala-Val -As p-Gly-His-Arg20-Ser-Leu-Ser-Asp-Lys-His-Gly-Leu-Pro.NH2) contains only two amino acid substitutions (Ser23 --> Asn and Pro29 --> Ala) compared with galanin from the bowfin, Amia calva (Amiiformes), but five amino acid substitutions compared with galanin from the trout (Teleostei). Similarly, the sturgeon tachykinin (Ser-Lys-Tyr-His-Gln-Phe-Tyr-Gly-Leu-Met.NH2) contains only one amino acid substitution (Tyr3 --> Ser) compared with scyliorhinin I previously isolated from bowfin stomach but five amino acid substitutions compared with trout substance P. The data support the hypothesis that the Acipenseriformes and the basal Neopterygians (gars and bowfin) share a close phylogenetic relationship.

Relative efficiencies of wither height and body weight increase from birth until first calving in Holstein cattle

Female Holstein calves from the Purina Research Center herd averaged 74 cm of height at withers and 40 kg of body weight (BW) at birth. At first calving (24 mo of age), calves averaged 138 cm of height at withers, 611 kg at precalving BW, and 547 kg at postcalving BW. Fifty percent of the total height increase occurred from birth to 6 mo of age, 25% occurred during 7 to 12 mo of age, and 25% occurred during 13 to 24 mo of age. Twenty-five percent of the total BW increase occurred from birth to 6 mo of age, 25% occurred from 6 to 12 mo of age, and the remaining 50% occurred from 13 to 24 mo of age. The increase in BW for 2-mo intervals, expressed as a proportion of the BW of the previous 2-mo interval, declined most rapidly during the first 6 mo, intermediately during the second 6 mo, and more slowly and progressively during the final 12 mo. Feed cost per unit of BW gain was lowest during the first 6 mo and then increased at a decreasing rate over the final 18 mo. The proportion of BW to height linearly increased over the 24-mo period. The increase in wither height as a proportion of the wither height during the previous period was greatest during the first 6 mo, intermediate during the second 6 mo, and lowest in the final 12 mo. Feed cost per unit of height increase was lowest in the first 6 mo, intermediate during the second 6 mo, and highest with a rapid increase during the final 12 mo. The increases in relative BW and wither height are the most rapid and cost efficient during the first 6 mo of life.

The conjoint trait of low high-density lipoprotein cholesterol and high triglycerides in adolescent black and white males

To evaluate the interrelationships among body composition, blood pressure, and lipid phenotypes in adolescent black and white boys, we assessed racial distributions of lipids, blood pressure, and obesity and their joint occurrence in black and white boys aged 10 to 15 years. Subjects were recruited from Cincinnati (OH) schools. Because the differences in high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) are the most profound coronary heart disease (CHD) risk factor differences between black and white males, we assigned subjects to one of four low-HDL-C and high-TG categories (normal and increased risk) using the age/race-specific 25th (HDL-C) and 75th (TG) percentiles. We then assessed racial distributions of lipids, blood pressure, and obesity by these phenotypes. Age differences between the black and white participants were significant, with the former about 3 months younger (P=.03), but black boys were more mature and were significantly taller and heavier and had a greater body mass index ([BMI] weight in kilograms divided by height in centimeters squared). Differences in the sum of the triceps, subscapular, and suprailiac skinfolds were not significant. Blacks had significantly higher HDL-C, lower TG, and higher diastolic blood pressure (DBP), but differences in systolic blood pressure (SBP) were not significant. In both racial groups, the body composition measures were significantly correlated with HDL-C, TG, and blood pressure levels; the correlations between HDL-C and both weight and BMI were significantly stronger in white boys. The proportion of boys of each race with low HDL-C and high TG was similar by design. In both racial groups, subjects with the conjoint trait had a significantly greater BMI, triceps skinfold, and sum of skinfolds than subjects in the other phenotypic groups. For white boys, participants with the conjoint trait had the highest SBP and DBP; differences in SBP were significant for comparisons to the normal- and high-TG group alone, and differences in DBP were significant for the comparison between normal and low HDL-C alone. For black boys, subjects with both normal HDL-C and TG had significantly lower SBP than boys with either the conjoint trait or high TG alone; none of the group differences in DBP were significant. Black had significantly less dense LDL (more LDL-C per apolipoprotein [apo] B). In each racial group, boys with the conjoint trait had the most dense LDL, significantly more dense than in any of the other phenotypes in black boys and significantly more dense than in boys with low HDL-C alone and normal boys in the white group. In both racial groups, the occurrence of no risk factors (>75th percentile TG, BMI, SBP, and DBP or <25th percentile HDL-C) and three or more risk factors was greater than expected by chance alone, and the occurrence of exactly one risk factor and two factors was less. When examined by phenotypic groups within race, boys in each racial group with the normal phenotype had a greater than expected percentage with no risk factors, and white boys with the conjoint trait were more likely to have a marked increase in multiple risk factors. Possible mechanisms for this clustering of risk factors and for the racial differences in the patterns are discussed.

Longitudinal correlates of change in blood pressure in adolescent girls

The objective of this study was to assess the longitudinal changes in blood pressure in black and white adolescent girls and evaluate potential determinants of changes in blood pressure, including sexual maturation and body size. A total of 1213 black and 1166 white girls, ages 9 or 10 years at study entry, were followed up through age 14 with annual measurements of height, weight, skinfold thickness, stage of sexual maturation, systolic and diastolic blood pressures, and other cardiovascular risk factors. Average blood pressures in black girls were generally 1 to 2 mm Hg higher than in white girls of similar age over the course of the study. Age, race, stage of sexual maturation, height, and body mass index (kg/m2) were all significant univariate predictors of systolic and diastolic blood pressures in longitudinal regression analyses. Black girls had a significantly smaller increase in blood pressure for a given increase in body mass index compared with white girls. The predicted increases in blood pressure per unit increase in body mass index (mm Hg per kg/m2) were as follows: systolic, 0.65+/-0.04 in whites and 0.52+/-0.04 in blacks (P<.001); diastolic fourth Korotkoff phase, 0.31+/-0.04 in whites and 0.15+/-0.03 in blacks (P<.001); and diastolic fifth Korotkoff phase, 0.31+/-0.05 in whites and 0.16+/-0.04 in blacks (P<.001). Understanding of the determinants of the racial differences in blood pressure could provide the rationale for future interventions to reduce the excess cardiovascular mortality in black compared with white women.

Purification and cardiovascular activity of [Met1, Met5]-bradykinin from the plasma of a sturgeon (Acipenseriformes)

The sturgeons (Order Acipenseriformes) are extant representatives of a group of primitive Actinopterygian (ray-finned) fish that probably shared a common ancestor with present-day teleosts. Incubation of heat-denatured plasma from a sturgeon (a hybrid of the shovelnosed sturgeon Scaphirhynchus platorynchus and the pallid sturgeon Scaphirhynchus albus) with either trypsin or porcine pancreatic kallikrein generated bradykinin-like immunoreactivity. The primary structure of sturgeon bradykinin was established as Met-Pro-Pro-Gly-Met-Ser-Pro-Phe-Arg. This amino acid sequence contains two amino acid substitutions (Arg1 --> Met and Phe5 --> Met) compared with mammalian bradykinin. Bolus injections of synthetic sturgeon bradykinin in doses as low as 1 pmol/kg into the dorsal aorta of unanesthetized sturgeon resulted in an immediate and significant fall in arterial blood pressure with a maximum depressor response at 300 pmol/kg. Thus, the cardiovascular response of the sturgeon to bradykinin resembles more closely the response of mammals rather than the predominantly pressor response seen in teleost fish. Sturgeon bradykinin produced a strong and concentration-dependent (EC50 = 4.7 +/- 0.7 x 10(-10) M) relaxation of rings of vascular tissue from the sturgeon ventral aorta that had been pre-contracted with acetylcholine. The data indicate that sturgeon tissues are particularly responsive to native bradykinin and suggest that the kallikrein-kinin system may have evolved before the appearance of the neopterygians (gars, bowfin and teleosts).

Self-esteem and adiposity in black and white girls: the NHLBI Growth and Health Study

PURPOSE

Obesity is assumed to have a negative impact on self-esteem because of the associated social stigmatization in Western society. Studies of the psychological effect of obesity in children are inconclusive and limited, particularly pertaining to minority populations. Most studies have assessed global rather than domain-specific measures of self-esteem and hence, may have lacked specificity to detect impairment of certain aspects of self-esteem most closely associated with obesity. The purpose of this study is to examine the effect of adiposity and other environmental factors on measures of perceived competence and self-adequacy in 2205 black and white girls aged 9-10 years.

METHODS

Domain-specific measures of self-esteem were studied by race and degree of adiposity, using Harter's "Self-Perception Profile for Children". Three Harter scales deemed more relevant to obesity (social acceptance (SA), physical appearance (PA), and global self-worth (GSW)) were selected for univariate and multivariate linear regression models to examine relationships between self-esteem level and adiposity (measured by the sum of triceps, subscapular, and suprailiac skinfolds (SSF)), race, pubertal maturation, and parental education. The relationship between adiposity and Harter scores was further examined with LOESS curves and also by comparing the mean scores of each quintile of SSF by race, as well as inter-quintile differences within race.

RESULTS

Adiposity in general impacted negatively on the scores of all three selected Harter scales. There was also racial variation in the relationship between the scores and adiposity, with the magnitude of the effect somewhat less in black girls. White girls exhibited a significant inverse relationship between SSF and SA scores while, in striking contrast, there was no variation in scores in black girls across all ranges of adiposity. Although there was a significant inverse relationship between adiposity and PA and GSW in both groups, the slope was steeper in white girls, particularly at higher ranges of SSF. Non-linearity in the relationship between SSF and the scores was seen in SA and PA scales.

CONCLUSIONS

The present study demonstrated a significant negative association between adiposity and the level of self-esteem in girls as young as 9 to 10 years. There were also intriguing racial differences in the selected domains of esteem. These results may help better understand cultural differences regarding the psychological impact of obesity and could be used to formulate appropriate strategies for public health policy.

Effects of diet and sexual maturation on low-density lipoprotein cholesterol during puberty: the Dietary Intervention Study in Children (DISC)

BACKGROUND

The Dietary Intervention Study in Children (DISC) is a multicenter, randomized, controlled clinical trial designed to examine the efficacy and safety of a dietary intervention to reduce serum LDL cholesterol (LDL-C) in children with elevated LDL-C.

METHODS AND RESULTS

The effects of dietary intake of fat and cholesterol and of sexual maturation and body mass index (BMI) on LDL-C were examined in a 3-year longitudinal study of 663 boys and girls (age 8 to 10 years at baseline) with elevated LDL-C levels. Multiple linear regression was used to predict LDL-C at 3 years. For boys, LDL-C decreased by 0.018 mmol/L for each 10 mg/4.2 MJ decrease in dietary cholesterol (P<.05). For girls, no single nutrient was significant in the model, but a treatment group effect was evident (P<.05). In both sexes, BMI at 3 years and LDL-C at baseline were significant and positive predictors of LDL-C levels. In boys, the average LDL-C level was 0.603 mmol/L lower at Tanner stage 4+ than at Tanner stage 1 (P<.01). In girls, the average LDL-C level was 0.274 mmol/L lower at Tanner stage 4+ than at Tanner stage 1 (P<.05).

CONCLUSIONS

In pubertal children, sexual maturation, BMI, dietary intervention (in girls), and dietary cholesterol (in boys) were significant in determining LDL-C. Sexual maturation was the factor associated with the greatest difference in LDL-C. Clinicians screening for dyslipidemia or following dyslipidemic children should be aware of the powerful effects of pubertal change on measurements of lipoproteins.

Attitudes of family practice residency program directors toward mandatory preemployment drug testing

BACKGROUND AND OBJECTIVES

As health care institutions adopt policies on substance use and abuse and mandatory substance abuse testing in the workplace, applicants for house staff positions may become the subjects of testing as a requirement for acceptance into a residency program. This study attempted to learn what directors of family practice residency programs feel about mandatory preemployment drug testing and its effect on house staff recruitment.

METHODS

We surveyed the directors of 420 US family practice residency programs, as listed by the American Academy of Family Physicians, in November 1994. All programs (community based, university affiliated, university based, and military) were included in the survey.

RESULTS

A total of 308 (73%) program directors responded. Of these, almost half disagreed with mandatory substance abuse testing and felt it should not be a condition of acceptance for a house staff position. Eighty-eight percent believed that the existence of a policy did not hinder recruitment. None felt it was an enhancement.

CONCLUSIONS

Preemployment drug testing for potential house staff remains a controversial issue, and it is unlikely that it will be universally implemented in the near future.

Safety of a fat-reduced diet: the Dietary Intervention Study in Children (DISC)

OBJECTIVE

To assess the relationship between energy intake from fat and anthropometric, biochemical, and dietary measures of nutritional adequacy and safety.

DESIGN

Three-year longitudinal study of children participating in a randomized controlled trial; intervention and usual care group data pooled to assess effects of self-reported fat intake; longitudinal regression analyses of measurements at baseline, year 1, and year 3.

PARTICIPANTS

Six hundred sixty-three children (362 boys and 301 girls), 8 to 10 years of age at baseline, with elevated low-density lipoprotein cholesterol, who are participants of the Dietary Intervention Study in Children.

MEASURES

Energy intake from fat assessed from three 24-hour recalls at each time point was the independent variable. Outcomes were anthropometric measures (height, weight, body mass index, and sum of skinfolds), nutritional biochemical determinations (serum ferritin, zinc, retinol, albumin, beta-carotene, and vitamin E, red blood cell folate, and hemoglobin), and dietary micronutrients (vitamins A, C, E, thiamin, riboflavin, niacin, vitamins B-6, B-12, folate, calcium, iron, zinc, magnesium, and phosphorus).

RESULTS

Lower fat intake was not related to anthropometric measures or serum zinc, retinol, albumin, beta-carotene, or vitamin E. Lower fat intake was related to: 1) higher levels of red blood cell folate and hemoglobin, with a trend toward higher serum ferritin; 2) higher intakes of folate, vitamin C, and vitamin A, with a trend toward higher iron intake; 3) lower intakes of calcium, zinc, magnesium, phosphorus, vitamin B-12, thiamin, niacin, and riboflavin; 4) increased risk of consuming less than two-thirds of the Recommended Dietary Allowances for calcium in girls at baseline, and zinc and vitamin E in boys and girls at all visits.

CONCLUSIONS

Lower fat intakes during puberty are nutritionally adequate for growth and for maintenance of normal levels of nutritional biochemical measures, and are associated with beneficial effects on blood folate and hemoglobin. Although lower fat diets were related to lower self-reported intakes of several nutrients, no adverse effects were observed on blood biochemical measures of nutritional status. Current public health recommendations for moderately lower fat intakes in children during puberty may be followed safely.

Nutrient intake and blood pressure in the Dietary Intervention Study in Children

Delineating the role that diet plays in blood pressure levels in children is important for guiding dietary recommendations for the prevention of hypertension. The purpose of this study was to investigate relationships between dietary nutrients and blood pressure in children. Data were analyzed from 662 participants in the Dietary Intervention Study in Children who had elevated low-density lipoprotein cholesterol and were aged 8 to 11 years at baseline. Three 24-hour dietary recalls, systolic pressure, diastolic pressure, height, and weight were obtained at baseline, 1 year, and 3 years. Nutrients analyzed were the micronutrients calcium, magnesium, and potassium; the macronutrients protein, carbohydrates, total fat, saturated fat, polyunsaturated fat, and monounsaturated fat; dietary cholesterol; and total dietary fiber. Baseline and 3-year longitudinal relationships were examined through multivariate models on diastolic and systolic pressures separately, controlling for height, weight, sex, and total caloric intake. The following associations were found in longitudinal analyses: analyzing each nutrient separately, for systolic pressure, inverse associations with calcium (P < .05); magnesium, potassium, and protein (all P < .01); and fiber (P < .05), and direct associations with total fat and monounsaturated fat (both P < .05); for diastolic pressure, inverse associations with calcium (P < .01); magnesium and potassium (both P < .05), protein (P < .01); and carbohydrates and fiber (both P < .05), and direct associations with polyunsaturated fat (P < .01) and monounsaturated fat (P < .05). Analyzing all nutrients simultaneously, for systolic pressure, direct association with total fat (P < .01); for diastolic pressure, inverse associations with calcium (P < .01) and fiber (P < .05), and direct association with total and monounsaturated fats (both P < .05). Results from this sample of children with elevated low-density lipoprotein cholesterol indicate that dietary calcium, fiber, and fat may be important determinants of blood pressure level in children.

Body weight, body condition score, and wither height of prepartum Holstein cows and birth weight and sex of calves by parity: a database and summary

Measurements of body weight (BW), body condition score, wither height, calf birth weight, and calf sex were recorded by parity from 728 Holstein cows and heifers at the Purina Research Center during the 8-wk prepartum period. Data were compiled over 5 yr. Mean daily BW gain was 0.93 kg. Loss of BW at parturition was 11.1%. Mean body condition score was 3.35 (five-point scale where 1 = thin to 5 = obese) and did not change during the 8-wk period. However, body condition score was lower for second parity cows than for heifers or cows in third or greater parity. Wither height averaged 138 cm at first parity and increased 3 cm from first to second parity. During fifth and sixth parities, wither height peaked at an additional 2 to 3 cm. Birth weights for all calves averaged 41.4 kg. Male calves were 8.5% heavier than female calves. Calves born to cows in second or greater parity had increased BW by 7 to 8%. Mean BW of twin calves was 15% less than that of single calves.

Lipoprotein and apolipoprotein differences in black and white girls. The National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVE

To define racial differences in lipoprotein and apolipoprotein levels in girls aged 9 to 10 years.

DESIGN

Baseline analysis of a prospective cohort study.

SETTING

Three clinical sites.

SUBJECTS

A total of 1871 black and white girls, aged 9 to 10 years, with complete maturation data (pubic hair and areolar development and menarche) and an 8-hour fast before blood draw.

MAIN OUTCOME MEASURES

Anthropometric measures and serum lipid, lipoprotein, and apolipoprotein levels.

RESULTS

All analyses were adjusted for maturational differences between blacks and whites (areolar or pubic hair development and menarche). The mean body mass index was marginally higher in black girls than in white girls (18.9 vs 18.3 kg/m2; P = .002), while the sum of skinfolds (34.5 vs 34.8 mm; P = .77) was equivalent. However, both body mass measures were skewed higher at the upper percentiles in black girls. The low-density lipoprotein cholesterol level was similar between black and white girls. Mean triglyceride values were higher in white girls than in black girls (0.92 vs 0.79 mmol/L [81 vs 70 mg/dL]; P < .001); however, these differences were most pronounced in the upper percentiles. Conversely, mean high-density lipoprotein cholesterol and apolipoprotein A-I levels were higher in black girls than in white girls (1.44 vs 1.37 mmol/L [56 vs 39 mg/dL] and 147 vs 138 mg/dL, respectively; both P < .001); and again the differences were most evident at the upper end of the distributions.

CONCLUSIONS

Racial differences in the mean levels of triglycerides, high-density lipoprotein cholesterol, and body mass in girls in the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS) at age 9 to 10 years were predominantly the result of differences observed at the upper end of the distributions. The reported black-white differences for mean high-density and low-density lipoprotein cholesterol and triglyceride levels in adult women are comparable to NGHS results. Distributional characteristics of these risk factors as well as trends in lipids, lipoproteins, and apolipoproteins, will be evaluated in an ongoing longitudinal assessment that covers the full maturational period.

Effects of dietary crude protein, breed, parity, and health status on the fertility of dairy cows

A study was conducted to determine the impact of dietary CP (13% vs. 20%), parity (first vs. second lactation or later), and breed (Holstein vs. Jersey) on the reproductive efficiency of dairy cows. Sixty-four cows were blocked by parity and breed and assigned to one of two treatments. Cows were removed from treatments on d 100 or 120 depending on pregnancy status. Cows were categorized by health status based on the occurrence of postparturient disorders. Plasma urea N concentrations were influenced by diet (8.6 vs. 21 mg/dl, 13 and 20% CP, respectively), parity, and breed. Reproductive indices were not influenced by diet except that days to first estimated ovulation increased for cows fed the 20% CP diet when health status was added to the model. Days to first observed estrus, first AI service, and cumulative pregnancy rate were affected by health status. Regression analysis for survival showed an interaction of diet and health status for days open. High CP diets tended to increase days open when cows had major health problems; otherwise, a high CP diet decreased days open. The implementation of a strict reproductive management program allowed high reproductive efficiency goals to be achieved regardless of plasma urea N concentrations.

Psychometric properties and validity of the obsessive-compulsive drinking scale

Abstinent alcoholics' self-reports of distressing alcohol-associated thoughts and compulsions to drink were evaluated by the Obsessive-Compulsive Drinking Scale (OCDS). Exploratory and confirmatory factor analyses on separate subject samples revealed that subjects' OCDS responses were best described by four correlated dimensions: alcohol obsessions, alcohol consumption, automaticity, and interference due to drinking. The validity of this four-factor solution was supported by the pattern of associations with drinking and coping style measures. In particular, alcohol obsessions were positively associated with alcohol dependence and use of passive/ avoidant coping. Automaticity was positively associated with the intensity and salience of drinking, and inversely associated with use of active/approach coping, as well as abstinence duration. The obsession and automaticity subscales of the OCDS may be useful in evaluating cognitive-motivational processes associated with recovery from alcoholism.

Sexual maturation and racial differences in blood pressure in girls: the National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVE

To evaluate racial differences in blood pressure in girls aged 9 to 10 years in the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS) and to evaluate the extent to which racial differences in blood pressure are explained by other factors, including sexual maturation and body size.

METHODS

The NGHS enrolled 539 black and 616 white girls aged 9 years, and 674 black and 550 white girls aged 10 years. Racial differences in blood pressure were examined. Relationships of stage of sexual maturation, height, and skinfold thickness with systolic and diastolic blood pressure were evaluated by multiple regression analysis.

RESULTS

The black girls had significantly higher systolic (102.0 +/- 8.90 vs 100.5 +/- 9.42 mm Hg, p <0.001) and diastolic (58.0 +/- 12.0 vs 56.5 +/- 12.51 mm Hg, p <0.01) blood pressures than the white girls. The black girls were also more advanced in sexual maturation and were taller (142.9 +/- 7.94 vs 139.6 +/- 7.05, p <0.001) and heavier (39.6 +/- 11.24 vs 35.3 +/- 8.73 kg, p <0.001) than the white girls. Both systolic and diastolic blood pressure were significantly correlated with level of maturation, height, weight, and sum of skinfolds. Stage of maturation was found to account for the difference in blood pressure between black girls and white girls. In a multiple regression analysis, controlling for height (for diastolic blood pressure) and for both height and sum of skinfolds (for systolic blood pressure) eliminated the effects of race and stage of maturation on blood pressure.

CONCLUSION

Racial differences in blood pressure were observed for 9- and 10-year-old girls and are explained by the fact that black girls were more mature than white girls. The effect of sexual maturation on blood pressure appears to operate through height and body fat. The effect of obesity may be more important for systolic than for diastolic blood pressure. Continuation of racial differences in blood pressure may result in a higher prevalence of hypertension for black women.

Race, socioeconomic status, and obesity in 9- to 10-year-old girls: the NHLBI Growth and Health Study

The purpose of this investigation was to determine whether measures of socioeconomic status (SES) are inversely associated with obesity in 9- to 10-year-old black and white girls and their parents. Subjects were participants in the Growth and Health Study (NGHS) of the National Heart, Lung, and Blood Institute. Extensive SES, anthropometric, and dietary data were collected at baseline on 2379 NGHS participants. The prevalence of obesity was examined in the NGHS girls and parents in relation to SES and selected environmental factors. Less obesity was observed at higher levels of household income and parental education in white girls but not in black girls. Among the mothers of the NGHS participants who were seen, lower prevalence of obesity was observed with higher levels of income and education for white mothers, but no consistent patterns were seen in black mothers. Univariate logistic models indicated that the prevalence of obesity was significantly and inversely associated with parental income and education and number of parents in the household in white girls whereas caloric intake and TV viewing were significantly and positively associated with obesity. Among black girls, only TV viewing was significantly and positively associated with the prevalence of obesity. Multivariate logistic regression models revealed that lower parental educational attainment, one-parent household, and increased caloric intake were significantly associated with the prevalence of obesity in white girls; for black girls, only increased hours of TV viewing were significant in these models. It is concluded that socioeconomic status, as measured by education and income, was related to the prevalence of obesity in girls, with racial variation in these associations. A lower prevalence of obesity was seen at higher levels of socioeconomic status in white girls, whereas no clear relationship was detected in black girls. These findings raise new questions regarding the correlates of obesity in black girls.

Differential classification of blood pressure by fourth and fifth Korotkoff phases in school-aged girls. The National Heart, Lung, and Blood Institute Growth and Health Study

The use of the onset of the fourth (K4) or fifth (K5) Korotkoff phase to determine diastolic blood pressure in children has been controversial; most recently, the Second Task Force recommended the use of K4 for children up to age 13 years and K5 for children age 13 and above. We performed a cross-sectional analysis of 1,155 nine-year old (53% white and 47% black) and 1,224 ten-year old girls (45% white and 55% black) in the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS). The mean blood pressures for the first, fourth, and fifth Korotkoff phases were 100.1 (+/- 8.9) mm Hg, 66.6 (+/- 9.8) mm Hg, and 56.8 (+/- 11.8) mm Hg for nine-year-olds and 102.8 (+/- 9.0) mm Hg, 68.1 (+/- 10.1) mm Hg, and 58.1 (+/- 11.9) mm Hg for ten-year-olds. The mean difference between K4 and K5 was 9.9 (+/- 6.4) mm Hg. The correlation between K1 and K4 was 0.45, between K1 and K5 was 0.34, and between K4 and K5 was 0.84. Elevation of blood pressure was defined at or above the 95th percentile based on the NGHS distribution for K1, K4, or K5; the relative risk of having an elevated K1 was 10.1 if K4 was elevated and 5.9 if K5 was elevated. Of the 159 subjects potentially classified with elevated diastolic pressure, 95 subjects (60%) would be classified differently depending on whether K4 or K5 was used to define elevated diastolic blood pressure. The choice of the onset of the fourth or fifth Korotkoff phase for determining diastolic blood pressure in children may have important implications for which individuals are classified as having hypertension.

Mother-daughter correlations of obesity and cardiovascular disease risk factors in black and white households: the NHLBI Growth and Health Study

OBJECTIVES

This study sought to evaluate obesity as a potential explanatory factor for the increased relative risk for cardiovascular disease in Black compared with White women.

METHODS

Familial associations for obesity and cardiovascular disease risk factors were assessed in 720 White and 580 Black mother-daughter pairs from the National Heart, Lung, and Blood Institute's Growth and Health Study by using Pearson's chi square, Spearman's correlations, and partial correlations.

RESULTS

Black girls and mothers were significantly heavier and had higher body mass indices than their White counterparts. In each racial group, significant, positive mother-daughter correlations existed for weight, body mass index, and triceps skinfolds, and for all cardiovascular disease risk factors. Obesity measures correlated positively with systolic blood pressure and triglycerides and inversely with high-density lipoprotein cholesterol in girls and mothers of both races. Correlations between mothers and daughters for exercise and ideal body shape were weak and did not explain obesity associations.

CONCLUSIONS

Intrafamilial associations of obesity, cardiovascular disease risk factors, and the obesity-cardiovascular disease risk factor relationship support the position that increased cardiovascular disease morbidity and mortality rates in Black women may be linked to excess obesity in Black women compared with White ones.

Feed intake and apparent digestibility of hay-supplemented brassica diets for lambs

Animal performance on brassica diets often does not reflect laboratory estimates of the nutritive value of the herbage. Hay supplementation of brassica pastures should increase diet DM and fiber intake and dilute anti-quality factors. The optimal hay:brassica ratio needed to achieve desirable animal performance, however, has not been established. Effects of changing the hay:brassica ratio on feed and water intake, apparent digestibility of diets, thyroid status, and anemia were examined in five Dorset-cross wether spring lambs (initial BW 32.8 +/- 3.2 kg). The experimental design was a 5 x 5 Latin square with 21-d periods (7 d of adaptation, 6 d of intake measurement, and an 8-d digestion trial with jugular blood drawn on last day). Diets contained chopped grass hay and tyfon (turnip x Chinese cabbage hybrid) at five hay:tyfon ratios (DM basis): 100:0; 75:25; 50:50; 25:75; and 0:100. As the proportion of tyfon in the diet increased, there were linear increases (P < .05) in ad libitum DMI (922 to 1,359 g/d), total water intake (1.75 to 13.06 L/d), digestible DMI (401 to 952 g/d), and apparent digestibility of DM (55.9 to 86.3%), CP (52.9 to 84.5%), and neutral detergent solubles (57.2 to 88.5%). Hay plus tyfon diets exhibited negative associative effects for apparent digestibility of NDF, ADF, and cellulose. Plasma thyroxine and triiodothyronine, packed cell volume, red blood count, and hemoglobin concentration were not affected by diet. Tyfon influenced DMI and apparent digestibility of diets in a manner similar to that of a concentrate.

Treated history of noninvasive grade 1 transitional cell carcinoma. The National Bladder Cancer Group

A total of 178 patients with grade 1 noninvasive (stage Ta) bladder tumors followed from 1 to 10 years (median 58 months) was prospectively evaluated by cystoscopy, transurethral resection, mucosal biopsies, cytology, size and number of tumors at diagnosis, recurrences, progression in grade and stage, number of negative or positive cystoscopies and death from all causes. Histopathological and cytological studies were confirmed by a Central Pathology Laboratory using the criteria for grade 1 as described previously. Of the patients 122 (68.5%) had a single tumor. Three-quarters of the patients had tumors of less than 2 cm., 95% had mild or no urothelial dysplasia and 1 had positive cytology results. There were 419 recurrent tumors in 109 patients (61%). Patients with multiple tumors were at a significantly greater risk for recurrences (p < 0.001). Size of tumor significantly affected the rate of recurrence in the first 2 years after initial diagnosis in single tumor patients only. Of the multiple tumor patients 90% experienced a recurrence compared to 46% of the single tumor patients. Of the 1,112 cystoscopies performed in 122 single tumor patients 18% were positive, compared to 33% of the 686 cystoscopies performed in 56 multiple tumor patients. A total of 29 patients had a change in grade, 5 having grade 3 and 24 having grade 2 tumors. Progression to stage T1 occurred in 5 patients and to stage T2 or greater in 3. Of the 36 patients who died, 1 died of obstruction due to bladder cancer. Experimental evidence supports the opinion that the cells of stage Ta, grade 1 tumors are different in several ways from normal urothelium. There are little data to support the use of the term papilloma to describe stage Ta, grade 1 tumors without reservation. The data demonstrate that the tumor diathesis being expressed ceases with time and for unknown reasons. Multiple tumor patients with stage Ta, grade 1 disease might be included in chemotherapy trials only with stratification and a control arm of transurethral resection/fulguration alone.