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Biomedical subjects

G H Anderson

Publications and source records attributed to G H Anderson.

At least 163 records · Page 9Linked to original sources
PubMed1981

Human milk feeding in premature infants: protein, fat, and carbohydrate balances in the first two weeks of life.

The nutritional adequacy of the premature infant's own mother's milk was assessed during the first two weeks of life. Studies were carried out in three groups (n = 8) of infants of less than 1,300 gm birth weight, matched for gestational age and weight, and fed either pooled breast milk, their mothers own milk, or infant formula (SMA20 or SMA24). Macronutrient balances at the end of the first and second postnatal weeks demonstrated differences in nitrogen and lipid absorption and retention between groups. Nitrogen retentions (mg/kg/day) were similar to normal fetal accretion rates only in the PT and SMA24 groups. Fat absorption was poorest from the heat-sterilized PBM (average of 64.0% of intake) when compared to PT (88.2%) and SMA groups (83.3%). Average gross and metabolizable energy intakes were similar among groups. Nutritional status as measured by plasma total protein and albumin concentrations and weight gain tended to be poorest in the PBM-fed infants. It was concluded that either PT milk or infant formula of a composition similar to SMA24 are more appropriate than pooled banked milk for feeding the premature infant during the first two weeks of life.

Anthropometry↗
PubMed1981

Intravenous nitrogen and energy intakes required to duplicate in utero nitrogen accretion in prematurely born human infants.

In order to determine the intravenous energy and nitrogen intakes required to achieve intrauterine rates of nitrogen accretion and growth, 30 studies were completed in 22 premature infants who were provided with various intakes of amino acids and energy (glucose +/- lipid) by peripheral vein infusion. At constant nitrogen intake, increasing energy intake (as lipid) from 50 to 80 nonprotein kcal/kg/day resulted in significant increases in nitrogen retention and weight gain. Increasing nitrogen intake from 494 to 655 mg/kg/day at constant low energy intake (mean = 53 kcal/kg/day) had no effect on nitrogen retention or weight change; however, at higher energy intakes (mean = 81 kcal/kg/day) increasing nitrogen intake correlated significantly with increasing nitrogen retention. At energy intakes greater than 70 kcal/kg/day the major determinant of nitrogen retention was nitrogen intake. When energy intake was greater than 70 kcal/kg/day, the infusion of nitrogen providing 430 to 560 mg/kg/day (2.7 to 3.5 gm protein/kg/day) resulted in the duplication of intrauterine nitrogen accretion rates.

Amino Acids↗
PubMed1981

3-methylbutanal metabolism in the adult rat.

1. 3-Methylbutanal is a normal constituent of human plasma and is elevated in patients with hepatic encephalopathy. Therefore these studies examined the possible source and site of synthesis of 3-methylbutanal and its effect on the central nervous system of adult rats. 2. 3-Methylbutanal was found to be a normal constituent of rat plasma and increased two to five times when leucine comprised 5% of the diet. Neomycin in the diet prevented the leucine-induced rise in plasma 3-methylbutanal. When this was injected at a dose of 120 mg/kg abnormal EEG patterns and sleep-like behaviour occurred, whereas smaller amounts (30 mg/kg) increased brain serotonin concentrations. 3. 3-Methylbutanal is a normal component of rat plasma: it may be derived in part from colonic bacterial breakdown of leucine and may influence central nervous system function. A possible relationship of 3-methylbutanal to the pathogenesis of hepatic encephalopathy is suggested.

Aldehydes↗
PubMed1981

Energy and macronutrient content of human milk during early lactation from mothers giving birth prematurely and at term.

The lactose, lipid, protein, and total energy content of milk produced during the first 4 wk of lactation was determined in milk from mothers giving birth prematurely and at term. Milk samples analyzed were representative of complete 24-h expressions. Over the first 4 wk of lactation lactose concentration increased, but nitrogen concentration decreased by an average of 25%. Lipid and total energy concentration increased by 25% from the 1st to 2nd wk and then remained stable in both groups. Although these changes with duration of lactation were similar in both groups, premature compared to full term milk was consistently 20 to 30% higher in total energy and lipid concentration, 15 to 20% higher in total protein and, after the 1st wk, approximately 10% lower in lactose. By comparing predicted nutrient intakes to estimated requirements of premature infants fed 150 to 200 ml/kg/day of their own mothers' milk, we predict that the quantities of protein and energy provided would be adequate to meet the needs of the infant during the early weeks of life.

Adult↗
PubMed1981

Plasma neutral amino acid ratios in normal man and in patients with hepatic encephalopathy: correlations with self-selected protein and energy consumption.

Plasma amino acid concentrations and the ratios of tryptophan and tyrosine to other large neutral amino acids (NAA) were related to prior food consumption by normal healthy adults and by adults with hepatic encephalopathy. Previous habitual (3-day) energy consumption by 32 healthy subjects correlated inversely with the fasting plasma tyr/NAA (r = --0.40, p less than 0.05), while the proportion of energy consumed as protein was inversely related to plasma trp/NAA (r = -0.63, p less than 0.001). Postprandial plasma trp/NAA of 11 normal subjects at 2 and 4 h also reflected (r = --0.62 and --0.69, p less than 0.05, respectively) the proportion of food energy chosen as protein at a single meal. Similarly, samples obtained from five patients with hepatic encephalopathy showed that when high plasma trp/NAA ratios occur these are likely to be due to the low protein intake prescribed. However, for these patients the tyr/NAA or the tyr and met/branched-chain amino acid ratios were above normal ranges caused by diet. The conclusion of this study is that the plasma trp/NAA ratio is associated with the proportion of dietary energy consumed as protein, whereas the plasma tyr/NAA ratio is associated with long-term total energy consumption.

Adolescent↗
PubMed1981

Cysteine supplementation to cysteine-free intravenous feeding regimens in newborn infants.

To determine if cysteine is an essential amino acid for the intravenously fed newborn infant, growth parameters, nitrogen balance, plasma sulfur amino acid levels, and urinary amino acid excretion of premature and term infants were measured in the presence or absence of infused cysteine. Control intravenous formulations provided amino acids, including adequate methionine, carbohydrate, lipid, minerals, vitamins, and trace elements to all infants. Group and pair-matched comparisons showed that nitrogen retention, weight change, and growth in length and head circumference were not affected by cysteine supplementation of 77 mg/kg/24 h. The failure of cysteine supplementation to alter nitrogen retention was independent of postnatal age or gestational age. Plasma 1/2 cystine concentration was increased by 60% in the supplemented group with a concomitant 3-fold increase in urinary excretion of 1/2 cystine and taurine, but not of urinary methionine or cystathionine. Cysteine-supplemented infants exhibited a small increase in 3-methylhistidine excretion compared to pair-matched controls, suggesting that either an increase in muscle protein catabolism or an increase in muscle mass may have occurred.

Amino Acids↗
PubMed1981

The renin-angiotensin-aldosterone system in diabetic patients with hyperkalemia.

Seven long-standing diabetic patients with spontaneous and intermittent hyperkalemia were studied in an effort to assess the normality of their renin-aldosterone axis. The administration of oral glucose, in the absence of insulin, caused a paradoxical rise in serum potassium with no significant change in plasma aldosterone concentration from controls. All displayed subnormal aldosterone-secreting capacity to known stimuli of aldosterone secretion such as low salt diet, angiotensin II infusion, and ACTH infusion. The paradoxical rise in serum potassium with hyperglycemia was corrected in all by concomitant administration of insulin or pretreatment with a mineralocorticoid. Our observations question the role of aldosterone deficiency in the phenomenon of glucose-induced hyperkalemia.

Adult↗
PubMed1981

Cryotherapy in the treatment of cervical intraepithelial neoplasia.

Cryotherapy was used to treat 516 patients with various degrees of dysplasia and carcinoma in situ over a 7-year period. Seventy-one percent of patients had either severe dysplasia or carcinoma in situ. In 88% of the patients treated, a single treatment session was successful in eradicating the lesion. Treatment was defined as successful when cytologic and colposcopic findings were negative 1 year after treatment. Five percent of patients were lost to follow-up. The criteria for selection of patients and possible causes of treatment failure are discussed.

Adult↗
PubMed1980

Effect of age on diagnostic usefulness of stimulated plasma renin activity and saralasin test in detection of renovascular hypertension.

The diagnostic usefulness of the timed intravenous pyelogram (IVP), isotopic renal flow study (renal flow), stimulated plasma renin activity (SPRA), saralasin infusion test, and renal vein renins (RVR) in detecting possible renal vascular hypertension was studied in relation to age. Among patients who had been off medication for 2 weeks and who had normal renal X-ray findings, the percentage of those with a high SPRA dropped from 22.3% in those aged 20-29 to 4.2% in those aged 60-69 years, and that in those showing a positive saralasin test dropped from 8.3% in those aged 20-29 to 4.3% in those aged 60-69. But among those with abnormal renal X-ray findings, the percentage rose from 5.7% to 20% (high SPRA) and from 16.3% to 33% (positive saralasin test). A high SPRA or positive saralasin detected a renal abnormality in 11.7% and 50%, respectively, of patients aged 20-29, and 75% and 85.7%, respectively, of those aged 60-69. The percentage of all patients on or off medication with abnormal renal X-ray findings and a renal vein renin ratio > 1.5 increased from 14.2% among those aged 20-29 to 84.2% among those aged 60-69. The results indicate an increasing usefulness with age of a high SPRA or a positive saralasin test in indicating an abnormal renal X-ray and an abnormal renal vein renin ratio, and thus a potentially correctable lesion.

Adult↗
PubMed1980

Macro-mineral content of milk obtained during early lactation from mothers of premature infants.

Milk from mothers giving birth prematurely was analyzed for Na, Cl, K, Mg, Ca and P concentrations. The data presented are from analyses of milk samples representative of complete 24-hour expressions and collected serially over the first 29 days of lactation from mothers giving birth at term (FT) and mothers giving birth prematurely (PT). Mineral composition of FT and PT milks was similar during the first month lactation. With the exceptions of Mg and P, the concentrations of the minerals studied were higher initially than at the end of the fourth week of lactation. From these data, intakes of premature infants fed their own mothers' milk can be estimated and compared to predicted mineral requirements for the premature infant. On the basis of this comparison, we suggest that the quantities provided of Na, Cl, K and Mg, but not Ca and P, would be adequate to meet requirements of premature infants during the early weeks of life.

Adult↗
PubMed1980

Human milk: comparison of the nitrogen composition in milk from mothers of premature and full-term infants.

Total nitrogen concentration of human milk during the first 4 weeks of lactation is higher in milk obtained from mothers giving birth prematurely than in milk from mothers giving birth at term. In the present study, the relative composition of total nitrogen was found to be similar in premature and full-term milk except for some minor differences in small molecule components. Total nitrogen is comprised of an average of 82% protein, 8% of the nonprotein nitrogen components--urea, free amino acids, uric acid, and ammonia--and the remaining 10% is predicted to be peptide nitrogen.

Female↗
PubMed1980

Hypertensive mechanisms in coarctation of the aorta. Further studies of the renin-angiotensin system.

The mechanisms of hypertension in coarctation remain to be clearly defined. In other hypertensive states, abnormal plasma renin activity (PRA) has been unmasked by the depletion of extracellular volume and the use of angiotensin antagonists. In a group of patients with coarctation, preoperative and postoperative evaluations of the renin-angiotensin system have been performed. Before operation, a group of patients with coarctation and a group of normal control subjects both underwent salt restriction followed by diuresis. A standard angiotensin antagonist (saralasin) test was performed on the patients with coarctation, and they demonstrated excessive renin-angiotensin activity compared to the control subjects. Following operation, paradoxical hypertension developed in all of the patients. Repeat saralasin test in these patients again revealed excessive angiotensin activity in the same patients as preoperatively. It appears that the renin-angiotensin system plays a more active role in coarctation than previously believed.

Adolescent↗
PubMed1980

Assessment of rat growth methods for estimating protein quality: interlaboratory study.

An interlaboratory study involving protein efficiency ratio (PER), net protein ratio (NPR), relative NPR (RNPR) and relative nitrogen utilization (RNU) was carried out. Six collaborators assayed 6 samples, including casein plus methionine which was used as a reference protein. Collaborators prepared their own diets and analyzed the diets for nitrogen. Test proteins were added at the 8% level (N X 6.25). PER values varied more than NPR values which varied more than either RNPR or RNU. RNU and RNPR produced almost identical values, but RNPR remains the official method of choice, because it is a well established method.

Animals↗