Body position, sleep states, and cardiorespiratory activity in developing low birth weight infants

The objective of this study was to determine the effects of body position (supine vs prone) on cardiorespiratory activity during quiet and active sleep in growing low birth weight (LBW) infants. The effect of postconceptional age on cardiorespiratory activity in the two positions was also evaluated. Fifty-one healthy, growing, appropriate for gestational age LBW infants (795-1600 g), ranging from 26-37 weeks in gestational age, were evaluated. All subjects were enrolled in an ongoing study of the effects of quality of dietary energy on the rate and composition of weight gain. Infants were randomly assigned to the supine or prone position for the first 3 h of the 6-h studies; the position was reversed for the second 3 h. Continuous recordings of cardiorespiratory activity were performed along with simultaneous minute by minute assignment of behavioral sleep state. Measurements of heart rate (HR), heart period variability (RR-SD), respiratory rate (f), and respiratory variability (fSD) were made each minute. Low birth weight infants had higher HR and f and lower RR-SD and fSD in the prone position compared to the supine position, during both quiet and active sleep. With increasing postconceptional age, positional differences in HR increased during quiet sleep and differences in RR-SD increased during both sleep states. These data demonstrate systematic differences in cardiorespiratory control related to body position during sleep. We speculate that such positional differences are due to variations in autonomic control, and may, in turn, contribute to variations in susceptibility to sudden infant death syndrome.

Spectrum of cystic variants of Wilm's tumour: cystic nephroma (multilocular cyst) and cystic partially differentiated nephroma--a report of four cases

Two cases of cystic nephroma (multilocular cyst of the kidney), and one case each of cystic partially differentiated nephroblastoma (CPDN) and rhabdomyomatous Wilms' tumour are described. All were male and in the pediatric age group. Grossly tumours were unilateral, unicentric and multiloculated. The need for proper designation of these lesions is highlighted because of difference in the treatment and prognosis of these tumours.

Flotation characteristics of cyanobacterium Anabaena flos-aquae for gas vesicle production

Cyanobacterium Anabaena flos-aquae was cultivated in photobioreactors for production of intracellular gas vesicles (GVs), as potential oxygen microcarriers. Natural flotation of the buoyant culture was investigated as a potential means of cell harvesting, because filtration and centrifugation tended to destroy the vesicles. Best flotation was found with actively growing culture and when conducted in the dark. The flotation-related cell properties, including the specific GV content, vesicle-collapsed filament density, and intracellular carbohydrate content, were measured to understand the phenomena. During the batch culture, the specific GV content remained relatively constant at 370 microL/(g dry cells) but the filament density (ranging 1.02 to 1.08 g/cm3) showed a decrease-then-increase profile. The increase began when the growth slowed down because of the reduced light availability at high cell concentrations. The dark flotation was studied with both actively growing (mu approximately 0.2 day-1) and stationary-phase cultures. The specific GV content of the stationary-phase culture remained relatively constant while that of the growing culture increased slightly. The intracellular carbohydrate content of the growing culture decreased much faster and more significantly, from 57 to 10 mg/(g dry cells) in </= 8 h. The filament density also decreased, apparently parallel to the profiles of carbohydrate content.

Gastrointestinal mucormycosis--an uncommon isolated mucormycosis

BACKGROUND

Isolated mucormycosis of the gastrointestinal tract is uncommon, with only two case reports from India.

OBJECTIVES

To study the clinicopathologic features of gastrointestinal mucormycosis in Indian patients.

METHODS

Eight cases of isolated gastrointestinal mucormycosis, seen over six years (1992-97) are reviewed.

RESULTS

Five of the patients were premature babies or infants, one was a 12-year-old boy, and two were middle aged. Symptomatology included vomiting, bloody diarrhea, upper gastrointestinal bleeding, abdominal lump and abdominal distention. All the neonates presented with intestinal perforation. The duration of symptoms was ten days or less in six cases. Mucormycosis was not suspected clinically in any patient. In six cases the diagnosis was established antemortem from resection or biopsy material. Only two patients received antifungal therapy and only one patient responded.

CONCLUSIONS

Isolated gastrointestinal mucormycosis is not uncommon in India. Early diagnosis may be helpful in reducing the high mortality.

Prevalence of atherosclerosis risk factors in adolescent school children

The emerging epidemic of atherosclerotic cardiovascular diseases in developing countries may have its roots in childhood. We studied atherosclerosis risk factors--tobacco use, obesity, hypertension, total cholesterol level and dietary intake of atherogenic nutrients in adolescent school children aged 13-17 years in Western India. Two hundred thirty-seven children (89 boys, 148 girls) were examined and prevalence of risk factors determined. Family history of coronary heart disease was found in 16 (6.8%), smoking or tobacco use in one (0.4%) and obesity (BMI > 90th percentile) in 24 (10.1%), borderline hypertension (> or = 136/86) in 65 (27.4%) and definite hypertension (> or = 142/92) in 17 (7.2%). Borderline hypercholesterolaemia (170-199 mg/dL) was in 78 (32.9%) and definite hypercholesterolaemia (> or = 200 mg/dL) in 16 (6.8%). Mean calorie intake was 1450 +/- 348 per day. Fats provided 38.4 +/- 8 percent of the calories, saturated fats contributed to 20.3 +/- 6.4 percent of calories, monounsaturated fats to 12.9 +/- 2.4 percent and polyunsaturated fats to 5.0 +/- 3.7 percent. Dietary cholesterol intake was 164 +/- 95 mg/day, sodium chloride intake 12.8 +/- 5.7 gm/day and fibre intake 6.5 +/- 4.6 gm/day. This study shows a high prevalence of metabolic and dietetic coronary risk factors among adolescents of the middle- and upper-middle class in India.

Adrenal lipoma. A case report

Lipoma of the adrenal gland is an extremely uncommon tumor detected incidentally at postmortem or during life when the patient undergoes investigations for other reasons. All tumors reported in the literature were very small in size. We report a case of lipoma of the adrenal gland in a 45-year-old male patient who was hypertensive and presented with pain in the abdomen. The symptomatic presentation, large size, laparoscopic removal and rarity of this tumor merit documentation in the literature.

Nucleolar organiser regions and morphologic subtypes of squamous cell carcinoma of cervix

Nucleolar organiser regions (NOR) are chromosomal segments coding for ribosomal RNA. The number of nucleolar organiser regions correlates with cellular proliferation and has a diagnostic and prognostic value in neoplastic diseases. The aim of this study was to study the morphologic subtypes of squamous cell carcinoma of the uterine cervix in biopsy and hysterectomy specimens and to determine the AgNOR counts in these morphologic subtypes. One hundred and seventy-nine cases of squamous cell carcinoma of the uterine cervix were classified into three morphological subtypes namely large cell non keratinising squamous cell carcinoma (113), keratinising squamous cell carcinoma (64) and small cell carcinoma (2). A correlation of histologic typing on biopsy and hysterectomy specimens was done in 142 cases with a complete correlation in 90.5%. Fifty-eight of these tumours were stained with silver nitrate to demonstrate Nucleolar organiser regions (AgNORS). The mean AgNOR count was higher (3.66) in keratinising squamous cell carcinoma, which is known to have a worse prognosis as compared to 3.04 in large cell non keratinising carcinoma and (3.45) in the two cases of small cell carcinoma of the uterine cervix.

Symptomatic adrenal myelolipoma. Clinicopathological analysis of 7 cases and brief review of the literature

Seven cases of adrenal myelolipoma comprising 5.8% of total adrenal tumors are described with a male-to-female ratio of 1.3:1. Five were symptomatic, of which 4 had a palpable abdominal mass, 2 cases detected incidentally were associated with carcinoma of the uterine cervix and renal cell carcinoma, respectively. The average age and duration of symptoms at presentation were 56 years (range 38-70 years) and 3.16 months (range 1-9 months). A CT scan was done in all cases, of which 5 showed a nonenhancing mass lesion with fat density diagnosed as adrenal myelolipoma. However, in 1 case radiological diagnosis of liposarcoma was maintained because of the huge size of the lesion whereas in another case the lesion was missed because of associated renal cell carcinoma. Interestingly the right adrenal was involved in all cases and the weight varied from 7 to 2,000 g. No recurrence was noted in the follow-up period (ranging from 3 months to 10 years).

Diet and infant behavior

We studied 142 preterm infants (mean gestation 31 weeks, mean birthweight 1364 g) fed prospectively varied protein and energy intakes. Infants were grouped as either slow or rapid growers based on rate of weight gain. Rapid growers had increased heart rates (166 vs 160 beats/min), respiratory rates (55.7 vs 53.9 bpm), energy expenditure (64.8 vs 61.6 kcal kg(-1) day(-1)), urinary C-peptide levels (1.59 vs 0.79 ng ml(-1)) and time in active sleep (78.0 vs 75.2%), and decreased spectral edge frequency in the electroencephalogram (2.96 vs 4.45 Hz) compared to slow growers. We conclude that preterm infants growing at varying rates manifest physiological and behavioral differences, and that these patterns may reflect altered autonomic balance.

Energy expended by low birth weight infants in the deposition of protein and fat

One hundred twenty low birth weight infants were enterally fed diets containing fixed differences in protein and energy content. Serial, biweekly measurements were made of metabolizable energy intake, energy expenditure, nitrogen balance, and distribution of states of sleep, from the time the infants were receiving full enteral intakes (180 mL/kg.d) until weight reached 2200 g. Using multiple regression analysis of energy expenditure against protein stored, and metabolizable energy, the energy expended in the deposition of protein was calculated to be 5.5 kcal/g +/- 1.1 kcal/g (SE) and the energy cost of fat deposited was 1.6 kcal/g +/- 0.3 kcal/g (SE). Estimated maintenance energy expenditure of the nongrowing low birth weight infant was 42.3 +/- 3.2 kcal/kg/d. Variations in distribution of sleep state, an assessment of the activity state of the infant, did not explain additional variability in energy expenditure, after adjusting for protein and energy storage.

Random primer p(dN)6-digoxigenin labeling for quantitation of mRNA by Q-RT-PCR and ELISA

The ability to accurately measure mRNA levels in samples of total RNA is essential for studies on control of gene expression. The mRNAs from the housekeeping gene for phosphoglycerate kinase (PGK-1) can serve as a quality control for RNA samples. We describe an enzyme-linked immunosorbent assay (ELISA) method for mRNA determination by Q-RT-PCR, a quantitative reverse transcriptase-mediated PCR assay with competitive internal standards. After PCR, two biotinylated capture primers, one specific for PGK-1 cDNA and another one for internal standard, are annealed in separate assays so that each can attach DNA to a streptavidin-coated microplate. The captured DNA is either internally labeled with digoxigenin (DIG) or is "developed" after annealing with DIG-labeled primers. Bound DNA is then quantitated by adding DIG-specific antibody with attached alkaline phosphatase and measuring phosphatase activity with a chromogenic substrate and a plate reader. We compared different capturing methods and various primers labeled with DIG at their 3' ends. We determined that amplified PGK-1 DNA specifically captured with biotinylated primers was efficiently assayed with random p(dN)6-DIG.

Evaluation of a mathematical model for predicting the relationship between protein and energy intakes of low-birth-weight infants and the rate and composition of weight gain

A model for predicting the relationship between protein and energy intakes of low-birth-weight (LBW) infants and the rate and composition of weight gain is described. It is based on linear multiple regression equations summarizing the rates of weight gain, nitrogen retention, and energy retention of 101 previously studied LBW infants fed protein intakes ranging from 2.25 to 3.9 g.kg-1.d-1 and concomitant energy intakes ranging from 115 to 147 kcal.kg-1.d-1 plus current theory concerning nutrient retention and body composition. To test the validity of the model, three combinations of protein and energy intake predicted by the model to result in specific rates and compositions of weight gain were fed to 44 LBW infants, and the observed rates of weight gain, protein accretion, and fat accretion were compared with the rates predicted by the model. Differences in these and other outcome variables between two of the groups, the intakes of which differed only in energy, also were compared to provide additional insight into the effect of concomitant energy intake on protein utilization. Across groups, actual outcomes correlated closely with predicted outcomes, supporting the validity of the model for the total population. However, outcomes of individual infants deviated as much as 30% from predicted outcomes; the magnitude of the deviation was independent of birth weight, gestational age, or size for gestational age.(ABSTRACT TRUNCATED AT 250 WORDS)

Arginine deficiency accompanies persistent pulmonary hypertension of the newborn

Persistent pulmonary hypertension of the newborn (PPHN) is a life-threatening disorder of neonates manifested by vasoconstriction of the pulmonary arteries. Recently, the gas nitric oxide (NO) has been used with some success in the management of infants with PPHN. Exogenous administration of NO selectively dilates the pulmonary vascular bed. NO is naturally synthesized in the body from the amino acid L-arginine. Here we report our findings that infants with PPHN are deficient in arginine and achieve normal or elevated plasma arginine concentrations with intravenous hyperalimentation. We prospectively identified and studied 10 infants with PPHN who were not receiving protein or amino acids for at least 24 h and compared their plasma arginine concentrations to 8 control infants without PPHN given similar nutrition. Plasma arginine concentrations were 32 +/- 14 and 52 +/- 20 mumol/l in infants with PPHN and control infants, respectively (p = 0.02). There were no other statistically significant differences in plasma amino acid concentration for any of the 22 other amino acids determined. Infants with PPHN who were subsequently treated with amino acid infusions had plasma arginine concentrations of 115 +/- 48 mumol/l (mean of ten determinations at 86 +/- 27 h after initiation of intravenous amino acids in five PPHN infants).

Cardiorespiratory costs of growth in low birth weight infants

The energy cost of growth includes two components: the energy stored in new tissues and the energy expended in all energy requiring steps associated with nutrient intake and net tissue accretion. Most of the energy expended in growth is accounted for by the energy cost of tissue anabolism: peptide bonds, lipogenesis, substrate transport, etc. However, to the extent that additional work is required of the heart and lungs for growth-related increases in O2 and CO2 transport, increased energy is also expended in cardiorespiratory work. Indirect estimates of these costs can be gained by examining the effects of diet and weight gain on heart rate and respiratory frequency. We studied 66 healthy low birth weight infants, mean study weight = 2010 g, fed constant intakes of protein (2.25-3.9 g/kg per day) and energy (100-150 kcal/kg per day). These diets led to rates of weight gain ranging from 13.9 to 21.7 g/kg per day, among the diet groups. Bi-weekly 6-h assessments of energy expenditure, heart rate, respiratory frequency and state of sleep were made after full enteral intake was achieved. After adjustment of heart rate for the effect of postnatal age, heart rate during active sleep was related to weight gain (y = 0.97 x + 144, r2 = 0.15), nitrogen-energy ratio of the diet (y = 5.9 x + 139,2 r2 = 0.22), and energy expenditure (y = 0.53 x + 129, r2 = 0.13). Multiple regression analysis revealed that age-adjusted heart rate during active and quiet sleep was significantly related to a combination of the same three variables (r2 = 0.31).(ABSTRACT TRUNCATED AT 250 WORDS)

Peak expiratory flow rates of healthy tribal children living at high altitudes in the Himalayas

Peak expiratory flow rates (PEFR) of 237 healthy tribal children living at or above 3000 metres from sea level were measured. The mean age, height and PEFR for boys were 10.7 years, 130.7 cm, 245.5 +/- 74.0 l/min, respectively. The values of these parameters in girls were 10.5 years, 128.2 cm and 222.3 +/- 78.6 l/min. The PEFR of these children, especially for boys, were comparable with North Indian urban children or children of the West.

Surgical correction of recurrent volar dislocation of the distal radioulnar joint. A case report

Recurrent volar dislocation of the distal ulna is an unusual injury. The role of various anatomic structures in providing stability of the distal radioulnar joint is controversial. Surgical reconstruction of the distal radioulnar joint was performed in a 25-year-old woman. A sling procedure was performed along with reconstruction of the fibrous osseous canal of the extensor carpi ulnaris (ECU). The ECU appears to play a role in stabilizing the distal radioulnar joint. When dislocation of the ECU tendon is noted intraoperatively, reconstruction of the fibrous osseous canal should be done.

Serum lipids in healthy tribals living at high altitudes in the Himalayas

Serum lipids of 70 healthy volunteer tribals (36 males, 34 females) living at high altitudes (3100-4500 metres) in the Himalayas were studied. The mean total cholesterol, triglycerides, HDLc, LDLc and VLDLc levels for the group were 178.6 +/- 19.5, 101.4 +/- 18.3, 44.1 +/- 12.4, 114.5 +/- 17.3 and 20.2 +/- 3.6 mg/dl respectively. There was no significant difference between the two sexes and the various age groups. The total cholesterol/HDL ratio for men and women was 4.2 and 3.9 respectively. The various interacting factors responsible for overall pattern of lipids in these individuals is discussed.

Antiviral and antibacterial lipids in human milk and infant formula feeds

Human milk and two infant formula feeds were tested for antiviral and antibacterial activity before being given to 21 low birthweight (LBW) infants; neither was present. When samples were aspirated from the stomachs of the infants within one to three hours of feeding, however, they reduced titres of enveloped virus and also killed both Staphylococcus epidermidis and Escherichia coli. The lipid fraction of the gastric aspirate from an infant who had been given human milk as well as those from four infants who had been given a conventional LBW infant formula feed, showed antiviral and antibacterial activities at least equal to the activities of the unfractionated aspirates. There was no consistent difference in antiviral or antibacterial activity of either the stomach aspirates or the lipid fractions of these aspirates between infants given human milk and those given formula feeds. The antiviral and antibacterial activities of the gastric aspirates seem to result from intragastric production of monoglycerides and fatty acids from the triglyceride content of the ingested feeds.

Growth, nutrient retention, and metabolic response of low-birth-weight infants fed supplemented and unsupplemented preterm human milk

Growth, nutrient retention, and metabolic response of low-birth-weight infants fed human milk provided by their mother; this milk supplemented with bovine milk protein, calcium, phosphorus, and sodium; or pasteurized term human milk with the same supplement were monitored from the time desired intake was tolerated until weight reached 2200 g. The supplement resulted in greater rates of weight gain (20.5 +/- 2.3 vs 16.4 +/- 2.2 g.kg-1.d-1) and nitrogen retention (353 +/- 76 vs 270 +/- 53 mg.kg-1.d-1), increase in plasma transthyretin (TTR) concentration (7 +/- 16 vs -3 +/- 9 mg.L-1.wk-1), a higher mean plasma albumin concentration (34 +/- 3 vs 32 +/- 4 g/L), and a higher plasma TTR concentration at discharge (100 +/- 22 vs 75 +/- 24 mg/L). All these variables correlated significantly with total nitrogen intake, suggesting that the differences are attributable to the protein content of the supplement. The supplement also resulted in greater rates of calcium and phosphorus accretion but the plasma alkaline phosphatase activity of the supplemented vs the unsupplemented groups did not differ.

Lyme disease in a Shimla boy

A patient with Lyme disease is described. He presented with meningitis-like picture, arthritis, and carditis (congestive cardiac failure and variable AV blocks without valvular lesions). Borrelia was present in the peripheral blood smear.

Hypoglycaemia following zinc phosphide poisoning

Two cases with severe hypoglycaemia following zinc phosphide poisoning are reported. Both patients succumbed to toxic myocarditis.

Growth, nutrient retention, and metabolic response in low birth weight infants fed varying intakes of protein and energy

Growth, nutrient retention, and metabolic response were determined in low birth weight (LBW) infants fed daily protein and energy intakes, respectively, of 2.8 gm/kg and 119 kcal/kg (group 1), 3.8 gm/kg and 120 kcal/kg (group 2), and 3.9 gm/kg and 142 kcal/kg (group 3). The mean rates of both weight gain and nitrogen retention in group 1 were somewhat greater than intrauterine rates; plasma concentrations of transthyretin and albumin also were acceptable. Thus the lower protein intake appeared to be adequate. On the other hand, the rates of weight gain and nitrogen retention in groups 2 and 3 were greater than those in group 1, supporting the efficacy of the higher protein intake with respect to growth. However, blood urea nitrogen and plasma amino acid concentrations also were higher in groups 2 and 3; both were higher in group 2 than in group 3, reflecting the positive effect of the higher energy intake on protein utilization. This observation, combined with data from an earlier study, indicates that protein intakes in excess of 3 gm/100 kcal will not be utilized completely. Energy expenditure in group 3 was greater than in group 1 but not group 2, raising the possibility that protein intakes not utilized completely contribute to diet-induced thermogenesis. The higher energy intake in group 3 vs group 2 did not affect rate of weight gain significantly, but energy storage in group 3, and hence fat accretion, was greater than that of other groups. In all groups the ratio of protein accretion to fat accretion reflected dietary proportions of protein and energy.

Levels of dichlorodiphenyltrichloroethane and hexachlorocyclohexane in human adipose tissue of the Indian population

Concentrations of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) were determined in 313 human omental fat samples collected from subjects from all five zones of India during 1977-1980. The median concentration of 2,2-bis-(p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE), total DDT, beta HCH, and total HCH were 3.4, 6.0, 1.3, and 1.9 mg/kg, respectively. The calculated national mean levels for DDT and HCH were 11.1 and 3.5 mg/kg, respectively. Although the values of DDT and HCH were not as high as those reported earlier, there is still a need for close monitoring of the bioaccumulation of these chemical residues in the Indian population.

Pediatric parenteral amino acid mixture in low birth weight infants

A mixture of amino acids designed to maintain normal plasma amino acid concentrations in infants and children requiring parenteral nutrition was evaluated in 28 low birth weight (LBW) infants (birth weight, 750 to 1750 g; postnatal age, 1 to 4 weeks) who required parenteral nutrients for optimal nutritional management. Sixteen babies received only parenteral nutrients for five to 21 days. Ten of these received a typical regimen by peripheral vein (1.91 +/- 0.16 g/kg/d of amino acids and 44.7 +/- 4.4 kcal/kg/d) and six received a typical regimen through a central vein (2.39 +/- 0.11 g/kg/d of amino acids and 95.9 +/- 14.5 kcal/kg/d). Mean weight gain of the peripheral vein subgroup was 10.3 +/- 10.6 g/kg/d; mean nitrogen balance was 230 +/- 66 mg/kg/d. Both the mean rate of weight gain (17.2 +/- 5.1 g/kg/d) and the mean rate of nitrogen retention (267 +/- 49 g/kg/d) of the central vein subgroup were similar to intrauterine rates. In these two subgroups as well as the total population, plasma concentrations of all amino acids except phenylalanine were within the 95% confidence limits of the plasma concentrations observed in LBW infants fed sufficient amounts of human milk to result in a rate of weight gain similar to the intrauterine rate. However, although plasma tyrosine and cyst(e)ine concentrations were within the 95% confidence limits of the plasma concentrations goals, the LBW infant's ability to use N-acetyl-L-tyrosine and cysteine HCl appears to be even less than that of the term infant and older child. In toto, these data support the efficacy of the amino acid mixture evaluated for LBW infants. Of equal importance, they suggest that the LBW infant's ability to use parenterally delivered amino acids is not as limited as commonly thought.

Protein quality in feeding low birth weight infants: a comparison of whey-predominant versus casein-predominant formulas

Growth (delta weight, delta length, delta head circumference, and delta skinfold thickness), nitrogen retention, and chemical indices of metabolic tolerance (BUN concentration and acid-base status; plasma amino acid concentrations including free and bound cyst(e)ine; urinary excretion of sulfur amino acids) were determined serially in low birth weight infants (900 to 1,750 g) fed formulas differing only in protein quality. One contained unmodified bovine milk protein (a ratio of whey proteins to caseins of 18:82); the other contained modified bovine milk protein (a ratio of whey proteins to caseins of 60:40). Both provided protein and energy intakes, respectively, of approximately 3.4 g/kg/d and 120 kcal/kg/d. Neither weight gain nor the rate of increase in length, head circumference, and skinfold thickness differed between the two groups. Nitrogen retention of the two groups also did not differ. Although BUN concentration and blood acid-base status did not differ, there were differences in the plasma concentrations of some amino acids. Plasma tyrosine concentration was higher in infants fed the casein-predominant protein, and plasma threonine concentration was higher in infants fed the whey-predominant protein. Neither plasma-free nor bound cyst(e)ine concentration differed between the two groups, but the greater cyst(e)ine intake of the whey-predominant group resulted in greater cyst(e)ine retention; this was accompanied by greater urinary taurine excretion, a reflection of greater taurine stores.

Spontaneous rupture of the tibialis anterior tendon. A case report

Spontaneous rupture of the tibialis anterior tendon occurred in a 65-year-old man with diabetes mellitus. Treatment with sliding tendon lengthening of the proximal portion of the tibialis anterior tendon was successful. This unusual injury occurs in diabetics older than 45 years of age, following minor trauma. The condition can be misdiagnosed as peroneal nerve deficit. Tibialis anterior tendon deficit should be included in the differential diagnosis of patients with isolated weakness of foot dorsiflexion.

Effects of varying protein and energy intakes on growth and metabolic response in low birth weight infants

Growth (weight, length, head circumference, and skinfold thickness), retention of major nutrients (nitrogen, sodium, potassium, chloride, calcium, and phosphorus), and chemical indices of protein adequacy (plasma albumin and transthyretin concentrations) and excess (blood urea nitrogen concentration and acid-base status; plasma amino acid concentrations) were determined serially from the time desired intake was tolerated until discharge weight (2200 gm) was reached in low birth weight infants (birth weight 900 to 1750 gm) fed one of three formulas, which provided protein and energy intakes, respectively, of 2.24 gm/kg/day and 115 kcal/kg/day (group 1), 3.6 gm/kg/day and 115 kcal/kg/day (group 2), and 3.5 gm/kg/day and 149 kcal/kg/day (group 3). Weight gain and rate of increase in length and head circumference were less in group 1 than in groups 2 and 3. Retention of most major nutrients also was less in group 1, as was blood urea nitrogen concentration, plasma albumin and transthyretin concentrations, and plasma concentrations of several amino acids. The rate of weight gain was not significantly greater in group 3 than in group 2, but the rate of increase in skinfold thickness was greater in this group. Neither nutrient retention nor metabolic indices differed between groups 2 and 3. These results suggest that a protein intake of 2.24 gm/kg/day is inadequate for the type of LBW infants studied, that the higher protein intakes are well tolerated, and that an energy intake of 149 vs 115 kcal/kg/day does not enhance utilization of the higher protein intakes studied.

An analysis of the variability in estimates of bioenergetic variables in preterm infants

Estimates of average daily energy expenditure and minimal observed oxygen consumption are commonly used to characterize the energy metabolism of neonates. Yet, the errors inherent in these estimates have not been defined. Using measurements of oxygen consumption and carbon dioxide production made in healthy growing low birth weight infants during eight consecutive 3-h interfeeding epochs, we have determined the variability in the mean oxygen consumption, carbon dioxide production, respiratory quotient, total daily energy expenditure, and the minimal observed oxygen consumption among the feeding epochs. The coefficient of variation for oxygen consumption ranged from 3.1 to 9.1%, for minimal observed oxygen consumption from 3.7 to 16.7%, for carbon dioxide production from 3.3 to 7.4%, and for total daily energy expenditure from 2.9 to 7.6%. The SDs for respiratory quotient ranged from 0.008 to 0.066. From these 24-h data we have calculated the error in predicting daily estimates of the mean values for these variables if observations are made for less than 24 h. As expected, this error decreases with increasing duration of observation. These data should prove useful in the design and interpretation of investigations of neonatal energy expenditure.