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Biomedical subjects

A Lucas

Publications and source records attributed to A Lucas.

At least 199 records · Page 11Linked to original sources
PubMed1993

Development of bowel habit in preterm infants.

The bowel habits in 844 preterm infants were observed during the first 56 days after birth. Delay in the passage of meconium beyond the second day occurred in 32%, and there was an inverse relation between gestational age and the day of first bowel action. Thereafter the increase in frequency of stools passed each day was related directly to the volume of milk ingested. Unfed infants had a modal defecation rate of one stool each day. For each 50 ml/kg increase in the volume of milk ingested the infants showed a further increase of one stool passed each day. Infants fed with human milk passed a greater number and softer stools than those who received cows' milk formula. In the absence of milk feeds an intrinsic pattern of large bowel motor activity, present as early as 25 weeks' gestation, ensures a defecation rate of one stool each day. The effect of enteral nutrition on this inherent motility is governed by the volume and composition of milk feeds, independently of gestational age.

Age Factors↗
PubMed1993

Increased bone mineral content of preterm infants fed with a nutrient enriched formula after discharge from hospital.

Bone disease with persistent reduced bone mineralisation is common in premature infants. To test the hypothesis that enhancement of nutritional intake after discharge from hospital improves bone mineralisation, 31 formula fed preterm infants were randomly assigned to receive standard or multinutrient enriched milk from the time of discharge. The calcium and phosphorus contents of the enriched milk were 70 and 35 mg/100 ml v 35 and 29 mg/100 ml for the standard formula. Bone mineral content was measured before discharge from hospital in 21 of the infants; there was no difference in the bone mineral content between the groups at that time (35 mg/cm for the two groups). There was a significant increase in bone mineral content for those infants receiving the enriched v standard formula at 3 and 9 months corrected postnatal age: at 3 months the bone mineral content was 83 v 63 mg/cm and at 9 months 115 v 95 mg/cm. The difference between the groups was thus maintained although not increased at a corrected age of 9 months, when the bone mineral content of infants fed the enriched but not the standard formula was no longer significantly different from that of normal infants after adjusting for body size. The difference was not explained by the larger body size in infants fed the enriched formula. The results suggest that the use of a special nutrient enriched postdischarge formula has a significant positive effect on bone growth and mineralisation during a period of rapid skeletal development.

Body Height↗
PubMed1993

Hyperphenylalaninaemia and outcome in intravenously fed preterm neonates.

Hyperphenylalaninaemia is likely to have occurred in many infants fed the intravenous amino acid solution Vamin 9. In this study of 336 preterm infants plasma phenylalanine was measured weekly during their hospital stay. Reference data on plasma phenylalanine were prepared for 243 infants who did not receive Vamin. Only 1% of these infants had a peak plasma phenylalanine concentration greater than 150 mumol/l (maximum 202 mumol/l) compared with 23% in 93 infants fed Vamin 9, seven of whom had concentrations > 300 mumol/l (maximum 704 mumol/l). High concentrations only occurred when the total energy to protein energy ratio in the intravenous solutions decreased to less than 8.5:1 and always occurred with a ratio less than 6.5:1, implying that hyperphenylalaninaemia may be minimised with an intravenous energy intake of greater than 34 kcal (142 kJ)/g protein. Nevertheless, follow up at 18 months post-term showed that increased plasma phenylalanine in this instance was not associated with any impairment of the Bayley mental development index (or subscales including fine motor, cognitive, or language development), the psychomotor development index, or the social maturity quotient. Thus, despite theoretical concern, an adverse outcome after hyperphenylalaninaemia induced by intravenous feeding has not been observed.

Amino Acids↗
PubMed1993

Renal function changes in microalbuminuric normotensive type II diabetic patients treated with angiotensin-converting enzyme inhibitors.

OBJECTIVE: To determine the effects of captopril on microalbuminuria and renal function in normotensive type II diabetic patients. RESEARCH DESIGN AND METHODS: A total of 26 patients were randomized in two homogeneous groups for clinical and analytical data in a 6-mo follow-up study. Group A received captopril (initial dose: 12.5 mg daily, increased according to tolerance); group B was untreated. RESULTS: Microalbuminuria decreased only in the treated group at 6 mo (P = 0.044) and a significant (P = 0.027) mean percentage change on microalbuminuria excretion between the groups was observed. Filtration fraction decreased in group A (baseline: 0.23 +/- 0.03; 6 mo: 0.22 +/- 0.04) and increased in group B (baseline: 0.22 +/- 0.04; 6 mo: 0.25 +/- 0.04) with a significant mean percentage change between the groups at 6 mo (P = 0.032). The mean percentage change in microalbuminuria was significantly correlated with a mean percentage change in diastolic blood pressure throughout the trial. Neither metabolic control nor sodium or protein intake changed in either group during the trial. CONCLUSIONS: These results suggest that captopril can help arrest microalbuminuria in normotensive type II diabetic patients, with a decrease in diastolic blood pressure and filtration fraction after a 6-mo treatment.

Albuminuria↗
PubMed1993

Calculated low-density lipoprotein cholesterol should not be used for management of lipoprotein abnormalities in patients with diabetes mellitus.

OBJECTIVE: To assess the validity of calculated low-density lipoprotein cholesterol by the Friedewald formula for management of lipoprotein abnormalities in patients with diabetes mellitus. RESEARCH DESIGN AND METHODS: Calculated LDL cholesterol by the Friedewald formula was compared with measured LDL cholesterol after separation by ultracentrifugation in 61 patients with type I diabetes, 50 patients with type II diabetes, and 116 healthy control subjects. RESULTS: Calculated LDL cholesterol coincided with measured LDL cholesterol, with < 10% error, in 54 (49%) patients with diabetes mellitus, and 85 (73%) control subjects. Calculated LDL cholesterol was overestimated, with an error of > or = 10% of measured LDL cholesterol in 39% of patients and 26% of control subjects, and underestimated in 13 and 1%, respectively. Despite a good correlation between calculated and measured LDL cholesterol, the intraclass correlation coefficients demonstrated a poor concordance between calculated and measured LDL cholesterol, both in patients and control subjects. When comparing the mean differences of calculated and measured LDL cholesterol for diabetic subjects versus control subjects, significantly greater differences in type II (but not type I) diabetic subjects were seen. CONCLUSIONS: Calculation of LDL cholesterol by the Friedewald formula may be inaccurate for assessment of cardiovascular risk in patients with type II diabetes and may not be appropriate for management of lipoprotein abnormalities in those diabetic patients.

Biomarkers↗
PubMed1992

Breast milk and subsequent intelligence quotient in children born preterm.

There is considerable controversy over whether nutrition in early life has a long-term influence on neurodevelopment. We have shown previously that, in preterm infants, mother's choice to provide breast milk was associated with higher developmental scores at 18 months. We now report data on intelligence quotient (IQ) in the same children seen at 7 1/2-8 years. IQ was assessed in 300 children with an abbreviated version of the Weschler Intelligence Scale for Children (revised Anglicised). Children who had consumed mother's milk in the early weeks of life had a significantly higher IQ at 7 1/2-8 years than did those who received no maternal milk. An 8.3 point advantage (over half a standard deviation) in IQ remained even after adjustment for differences between groups in mother's education and social class (p less than 0.0001). This advantage was associated with being fed mother's milk by tube rather than with the process of breastfeeding. There was a dose-response relation between the proportion of mother's milk in the diet and subsequent IQ. Children whose mothers chose to provide milk but failed to do so had the same IQ as those whose mothers elected not to provide breast milk. Although these results could be explained by differences between groups in parenting skills or genetic potential (even after adjustment for social and educational factors), our data point to a beneficial effect of human milk on neurodevelopment.

Age Factors↗
PubMed1992

Plasma folate levels in preterm infants, with and without a 1 mg daily folate supplement.

One hundred and four preterm infants were studied during the first few months of life in the Special Care Baby Unit of Addenbrooke's Hospital, Cambridge, United Kingdom. Previously, it had been the daily practice within the Unit to give a 1 mg oral supplement of folate (in the form of pteroylglutamic acid), once the infants had commenced full enteral feeding. At least one blood sample was obtained from 70 infants before oral folate supplementation was started. In these, the plasma folate levels fell progressively from a median value of 45 micrograms/l to a median of 12 micrograms/l, by the 2nd-3rd week of life. Once started on the oral supplement, 83 of the infants provided at least one blood sample. The plasma folate level of these infants rose immediately to a median value of 300 micrograms/l and a maximum of 1000 micrograms/l. Within individuals, these plasma folate levels decreased progressively following the introduction of the supplement, despite continuing daily supplementation. In a typical baby this decrease appeared to be explained by an increase in body-size, i.e. dilution of the folate into a larger pool. The implications of this level of supplementation are discussed, and in the light of our observations we suggest that daily supplementation in the range, 0.05-0.2 mg folate may be preferable for well preterm infants.

Dose-Response Relationship, Drug↗
PubMed1992

High folate intakes related to zinc status in preterm infants.

The former practice of giving 1 mg (2.27 mumoles) oral folic acid daily to premature infants receiving enteral feeds was assessed with respect to zinc status in Cambridge, United Kingdom. A group of 60 preterm infants, 80% of whom were receiving 1 mg oral folic acid daily, were studied for up to the first 16 weeks of life. Plasma folate and plasma zinc were measured for each subject. A significant inverse relationship was found between the maximum attained serum folate level and the minimum attained serum zinc level, (t = 5.0, 58 df, P less than 0.0001). This remained significant after corrections had been made for gestational age at birth, fetal growth retardation, birth weight, sex, diet, assisted ventilation and length of time to full enteral feeding. The hypothesis that very high folate intakes may adversely affect serum zinc levels and, by inference, zinc status in preterm infants could not be rejected. Caution is therefore advised when prescribing such very high folate doses daily for small preterm infants.

Dose-Response Relationship, Drug↗
PubMed1992

A prospective analysis of vascular access device-related infections in children.

To identify significant predictors of device-related infections, we performed a prospective, nonrandomized analysis of our experience with vascular access devices over a 2-year period in a pediatric oncology population. Variables analyzed included: (1) age at placement, (2) sex, (3) underlying disease, (4) type of device used (catheter v port), and (5) total white blood cell count at placement. Quantitative microbiologic criteria were used for diagnosis of bacteremia while clinical and microbiologic criteria were used in diagnosis of tunnel/port/site infections. During the study period a total of 351 devices, comprising 78,159 days in situ, were placed and data for univariate and multivariate analysis were available on 271 (77%). The mean age at placement was 7.2 +/- 4.7 years for catheters and 9.5 +/- 4.8 years for implantable devices (P less than or equal to .01). Significant predictors of device-related infections in univariate analysis were type of device (P less than or equal to .0001) and age (P less than or equal to .002). External catheters and age less than or equal to 7 years were associated with increased risk of infection. Underlying disease had a marginal effect on the infection rate (P = .08). In multivariate analysis, device type (P less than or equal to .0001) and age (P less than or equal to .002) continued to affect infections, whereas underlying disease demonstrated only a borderline effect (P = .14). We conclude that device type and age significantly affect the rate of device-related infections. These data support increased use of implantable devices in pediatric oncology patients.

Catheters, Indwelling↗
PubMed1992

Comparative effects of captopril versus nifedipine on proteinuria and renal function of type 2 diabetic patients.

Our study compared the effects of an angiotensin-converting enzyme inhibitor (captopril) versus a calcium antagonist (nifedipine) on proteinuria and renal function in patients with diabetic nephropathy. A randomized follow-up study was designed. Type 2 diabetic patients, with established diabetic nephropathy (proteinuria greater than 0.5 g/24 h), were treated with nifedipine (10 patients, group A) or captopril (10 patients, group B) for 6 months. Arterial blood pressure, metabolic parameters, proteinuria and renal function were measured and compared. Mean percentage differences for glomerular filtration rate, renal plasma flow and filtration fraction between the two groups were calculated. No significant differences were observed in serum glucose, glycosylated hemoglobin (hemoglobin A1c), Na+, K+ or albumin in either group or between groups. Blood pressure decreased significantly with both treatments and mean blood pressure was significantly lower in group A compared with group B at 6 months (Mann-Whitney U-test, P = 0.03). Proteinuria was similar in both groups at randomization, but after 3 and 6 months of treatment significant reductions were observed only in the group treated with captopril (P less than 0.01). A significant decrease in filtration fraction was observed in group B with an increase in group A (Mann-Whitney U-test, P = 0.03). Multiple regression analysis identified the therapeutic agent administered as an independent variable for decrease in proteinuria. It is concluded that antihypertensive treatment with captopril, but not with nifedipine, reduced proteinuria in patients with diabetic nephropathy, although a better mean blood pressure was obtained with nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1992

Suppressive therapy with levothyroxine for solitary thyroid nodules.

OBJECTIVE: To evaluate the effect of treatment with TSH suppressive dose of levothyroxine in patients with benign thyroid nodules. DESIGN: Prospective randomized study. Group A (n = 20) patients received levothyroxine and group B (n = 20) patients did not. The dose of levothyroxine was adjusted to obtain an effective suppression of TSH. A clinical, analytical and morphological (with ultrasound) review was performed every 3 months. The mean +/- SD follow-up period was 10.6 +/- 2.2 months. PATIENTS: Forty euthyroid women with solitary thyroid nodule on palpation, cold on scintigraphy and cytologically benign without contraindication participated. MEASUREMENTS: At entry: biochemical and hormonal parameters, thyroid scintigraphy and thyroid ultrasonography. Every 3 months additional determinations of thyroid hormones and TSH levels were carried out, if necessary, to verify effective TSH suppression. Every 6 months thyroid ultrasound imaging was performed. RESULTS: Patients were euthyroid at entry into the study. The mean dose of levothyroxine necessary to obtain TSH suppression was 2.82 +/- 0.6 micrograms/kg/day. No significant modification in the thyroid nodule diameter (mean +/- SD 2.6 +/- 1.2 vs 2.5 +/- 1.2 cm) or in the thyroid nodule volume (10.3 +/- 11.9 vs 10.1 +/- 12.2 ml) were observed in group A. In group B the results were similar (2.8 +/- 0.9 vs 2.7 +/- 1.8 cm and 9.2 +/- 6.4 vs 9.2 +/- 9.5 ml, respectively). No differences were found in either group in the number of nodules that reduced significantly their volume (four and three, respectively). CONCLUSIONS: The suppressive therapy with levothyroxine was not effective in reducing nodule sizes in patients with solitary benign thyroid nodules.

Adult↗
PubMed1992

Randomised trial of nutrition for preterm infants after discharge.

In a randomised double blind trial, the effect on growth and clinical status of a nutrient enriched 'post-discharge' milk formula versus a standard term formula, was compared in 32 exclusively bottle fed preterm infants. The formulas were used as the sole milk intake up to a postnatal age of 9 months. Significant increases in linear growth and weight gain were observed in the infants who received the enriched diet. There were no differences in vomiting, posseting, or bowel habit between the groups. Formula volumes ingested were similar between diet groups, indicating that the difference in formula composition did not affect the infants' regulation of intake. These preliminary data suggest that there is a role for specially designed formulas for preterm infants after discharge from hospital.

Animals↗
PubMed1992

Postdischarge formula consumption in infants born preterm.

In 31 infants born preterm and formula fed ad libitum, all milk intake was weighed from hospital discharge to nine months post-term. Mean daily milk intake was high, reaching 230 g/kg before four weeks post-term and was still over 150 g/kg beyond six months. Five of the 31 infants (16%) consumed 300-350 g/kg; 50% 'voluntarily' consumed more than upper recommended limits for energy intake and 35% did so for protein intake.

Body Weight↗
PubMed1992

Randomised trial of a ready-to-feed compared with powdered formula.

Forty three infants were assigned randomly to a ready-to-feed infant formula or a standard formula that required reconstitution from powder. Despite similar nutrient composition of the two formulas those fed the powdered formula had significantly increased body weight and skinfold thickness gains, and became significantly heavier than a further group of 20 breast fed infants by 3 and 6 months. Of those fed the powdered formula 6/19 had become overweight (above the 90th or 97th centile) by 6 months, whereas 1/19 fed the ready-to-feed product was overweight at this age. While differences in fat absorption might have been contributory, our data suggest that errors in reconstitution of formula from powder might be the main cause for the growth differences observed. If it is appropriate to take the breast fed infant as a model, infants fed ready-to-feed formula in this study showed a more physiological pattern of growth than those fed a standard formula reconstituted from powder. These results require replication using other formulas as the findings have potentially important implications for infant feeding.

Body Weight↗