Increased risk of vitamin B-12 and iron deficiency in infants on macrobiotic diets

The blood iron, vitamin B-12, and folate status of the 1985 birth cohort of Dutch infants aged 10.1-20.4 mo fed macrobiotic diets (n = 50) and matched omnivorous control infants (n = 57) was measured. Fe deficiency (combination of Hb less than 120 g/L, ferritin less than 12 micrograms/L, and FEP greater than 1.77 mumol/L) was observed in 15% of the macrobiotic group but not in the control group (p = 0.003). Plasma vitamin B-12 concentrations in the macrobiotic group were far below those of the control group (geometrical mean: 149 and 404 pmol/L, respectively, p less than 0.001). Plasma folate concentrations were higher in the macrobiotic group (31.6 +/- 11.7 nmol/L) than in the control group (21.1 +/- 8.8 nmol/L, p less than 0.001). In the macrobiotic group mean corpuscular volume, mean corpuscular hemoglobin mass, and mean corpuscular hemoglobin concentration were higher and hematocrit and red blood cells were lower (all p less than 0.05) than in the control group. It is advised to incorporate regular servings of animal foods into the macrobiotic diet to obtain an adequate amount of vitamin B-12.     

Serum sex hormone-binding globulin levels in thyroid diseases

Synthesis of "sex-hormone binding globulin" is influenced by the thyroid hormones and its concentration in the serum may be a marker of the thyroid hormone effect at the peripheral tissue (liver) level. Compared to euthyroid controls serum "sex-hormone binding globulin" concentration is elevated in overt hyperthyroidism (141.6 +/- 37.6 vs 48.3 +/- 16.2 nmol/l; p less than 0.001), conversely, its mean level is decreased in the hypothyroid group of patients (24.9 +/- 14.8 vs 48.3 +/- 16.2; p less than 0.001). In the group of subclinical hyperthyroidism the mean value of "sex-hormone binding globulin" corresponds to that in control subjects (47.4 +/- 16.8), while its serum level is near the lower border of the normal range in subclinical hypothyroidism (33.6 +/- 6.1 vs 48.3 +/- 16.2; p less than 0.01). During thyroid hormone replacement for hypothyroidism measurement of serum "sex-hormone binding globulin" may help to assess the response of the target organs to the hormone therapy. In patients with peripheral thyroid hormone resistance serum "sex-hormone binding globulin" level is within the normal range (51.3 +/- 9.8), its determination supports the diagnosis of this disease.     

Studies of whole blood associated acetaldehyde as a marker for alcohol intake: effect of gender in mice

A study was undertaken in C57BL mice to evaluate the effect of gender on whole blood associated acetaldehyde following exposure to ethanol in the drinking water (10% v/v). Whole blood associated acetaldehyde (WBAA) was measured from capillary blood samples using a fluorigenic high performance chromatographic assay on days 0, 7, 15 and 27. Ethanol consumption did not impair growth of either male or female mice when compared to controls. Following administration of ethanol, WBAA increased in both male and female mice but marked gender differences were apparent. Female mice consumed more fluid relative to body weight than males (155 +/- 27 S.D. vs. 124 +/- 19 ml/kg/day, p less than 0.001), but had lower mean WBAA levels during the four weeks of ethanol administration (137 +/- 37 vs. 318 +/- 66 nmol/g hemoglobin, p less than 0.001). WBAA levels in male mice were stable over the course of the experiment. Female mice were found to have peak WBAA levels on day seven after which time levels decreased significantly. These experiments emphasize gender differences in ethanol metabolism as well as the need to establish norms based on gender for assays of ethanol consumption which use acetaldehyde adducts with blood proteins.     

Nutritional status of diabetic and nondiabetic patients after renal transplantation

To assess whether there was improvement in the nutritional status of Type I insulin-dependent diabetics treated with renal transplantation as compared with dialysis, 24 diabetics and 21 nondiabetics were studied 22.6 +/- 23.8 mo after transplantation. Nutritional assessment included weight, height, triceps skinfold thickness, midarm muscle circumference (MAMC), serum albumin, and transferrin. Mean age of the 28 males and 17 females was 37.1 +/- 9.4 yr. Weight of diabetics increased from 55.6 +/- 8.4 kg to 61.5 +/- 9.5 kg (p less than 0.05); weight for height, from 81 +/- 8% to 95 +/- 9% (p less than 0.001); and serum albumin, from 3.8 +/- 0.5 gm/dl to 4.3 +/- 0.4 gm/dl (p less than 0.001). Weight also increased significantly in nondiabetics from 64.5 +/- 10.5 kg to 72.1 +/- 13.5 kg (p = 0.05); weight for height, from 96 +/- 15% to 108 +/- 16% (p less than 0.05); but not albumin, 4.1 +/- 0.7 gm/dl to 4.4 +/- 0.6 gm/dl (p greater than 0.05). Serum transferrin was 210 +/- 62 mg/dl in diabetics and 226 +/- 52 mg/dl in nondiabetics. Forty-two percent of diabetics and 29% of nondiabetics had a MAMC less than 5th percentile, indicating protein-calorie malnutrition. Results suggest a significant improvement in nutritional status after transplantation in both diabetics and nondiabetics, but particularly in the diabetic group.     

Reduced concentration of hepatic alpha-tocopherol in patients with alcoholic liver cirrhosis.

The concentration of alpha-tocopherol was measured in liver biopsy specimens obtained from 83 patients with alcoholic and non-alcoholic liver diseases. The mean hepatic vitamin E content (as alpha-tocopherol) was significantly lower in 23 patients with alcoholic cirrhosis (17.6 +/- 12.1 nmol/mg wet weight liver), compared with 12 patients with normal liver histology (39.2 +/- 29.7 nmol/mg, P less than 0.01). The mean serum concentration of alpha-tocopherol was lower in patients with alcoholic cirrhosis (13.9 +/- 7.0 mumol/l) than in individuals with alcoholic fatty liver (21.3 +/- 9.3 mumol/l, P less than 0.01) and patients with normal liver histology (23.4 +/- 11.6 mumol/l, P less than 0.01). A decreased ratio of serum alpha-tocopherol/total serum lipids was also observed in patients with alcoholic cirrhosis, compared with patients with normal liver histology (P less than 0.05). There was a significant correlation between concentrations of alpha-tocopherol in liver and serum (r = 0.43, P less than 0.001). Furthermore, serum alpha-tocopherol correlated with retinol (r = 0.53, P less than 0.001), selenium (r = 0.45, P less than 0.001), and albumin (r = 0.37, P less than 0.001) in serum. We suggest that the reduced content of hepatic alpha-tocopherol observed in some patients may play a role in ethanol-induced lipid peroxidation.     

Folic acid and pyridoxal-5'-phosphate losses during high-efficiency hemodialysis in patients without hydrosoluble vitamin supplementation.

OBJECTIVES: To determine the serum status in folate, pyridoxal-5'-phosphate (the active moiety of pyridoxine), cobalamin, and total homocysteine of chronic dialysis patients not routinely supplemented with B-complex vitamins and to evaluate induced intradialytic losses during high-efficiency hemodialysis. DESIGN: A cross-sectional study. SETTING: A university medical center providing tertiary care. PATIENTS: Thirty-six chronic dialysis patients (23 men and 13 women, mean age 57+/-13 years) treated since 3.8+/-2.2 years by hemodialysis and not supplemented with hydrosoluble vitamins. METHODS: Thrice-weekly hemodialysis was performed using CT-190G (Baxter, IL) or F-20 (Hospal, St-Leonard, Canada) reused dialyzers with a mean blood flow rate of 371+/-40 mL/min, a dialysate flow rate of 500 mL/min, and a mean session time of 3.7+/-0.4 hours. Prehemodialysis serum vitamin B(12) and homocysteine, and predialysis and postdialysis serum folate, pyridoxal-5'-phosphate, and urea were measured. Blood-side folate and pyridoxal-5'-phosphate clearances were calculated. RESULTS: Predialysis serum total homocysteine was above normal in all patients, with values ranging from 14.4 to 158.0 micromol/L (mean 40.2+/-29.6 micromol/L, median 33.5 micromol/L). Whereas the majority, 21 patients, had evidence of coronary, cerebrovascular, and/or peripheral vascular diseases, there was no difference in total homocysteine in patients with or without vascular disease (respectively, 40.8+/-37.0 micromol/L v 39.4+/-15.1 micromol/L, P = NS). Predialysis serum concentrations of pyridoxal-5'-phosphate were reduced in 20 patients (56%) and were in the lower normal range for 14 patients. Predialysis and postdialysis serum folate concentrations were 12.4+/-6.1 nmol/L and 8.6 +/- 3.6 nmol/L, whereas predialysis and postdialysis serum pyridoxal-5'-phosphate concentrations were 11.1+/-7.5 nmol/L and 8.0 +/-5.9 nmol/L. Percent reduction ratios were 68.4% +/- 6.6% for urea, 26.3%+/-16.0% for folates, and 27.9%+/-14.2% for pyridoxal-5'-phosphate. Blood-side clearances reached 134.7+/-22.2 mL/min for folates and 54.4+/-38.2 mL/min for pyridoxal-5'-phosphate. There was no significant difference in predialysis serum folate and pyridoxal-5'-phosphate in patients with or without evidence of vascular disease. CONCLUSION: This study confirms that: (1) total serum homocysteine levels are very high in chronic hemodialysis patients not supplemented with B-complex vitamins; (2) folate is significantly cleared or lost during high-efficiency hemodialysis; and (3) pyridoxal-5'-phosphate, the active moiety of pyridoxine, is depleted in most chronic hemodialysis patients without supplementation and that high-efficiency hemodialysis contributes to its depletion.     

Trace element nutrition status and dietary intake of children with phenylketonuria

The trace element status (copper, iron, zinc, manganese, chromium, and selenium) of 20 dietetically treated phenylketonuric (PKU) children was assessed. Significantly higher intakes of copper (p = 0.002) and iron (p = 0.005) were noted in PKU children compared with their siblings. No significant differences were found for zinc, manganese, or chromium. Intake of selenium was significantly lower (p = 0.0001) in PKU children (8.4 +/- 3.9 micrograms/d) than in siblings (41.6 +/- 9.4 micrograms/d). Plasma and urine selenium and erythrocyte glutathione peroxidase activity (GSHpx) were significantly lower (p = 0.001) in PKU children (0.38 +/- 0.11 mumol/L, 58.0 +/- 34.5 nmol/d, and 14.2 +/- 5.5 U/g Hb, respectively) than in siblings (0.82 +/- 0.15 mumol/L, 165.2 +/- 49.4 nmol/d, and 22.7 +/- 5.2 U/g Hb, respectively). No differences were found in plasma and urine concentrations of other elements. Intake of selenium was significantly correlated with erythrocyte GSHpx (r = 0.87, p = 0.0001) and plasma selenium (r = 0.71, p = 0.0001) for the combined groups. The need and possible procedures, including dietary manipulation, for increasing selenium intake in PKU subjects are discussed.     

Activities of the hepatic enzymes of vitamin B6 metabolism for patients with cirrhosis

Patients with cirrhosis and other hepatic diseases frequently exhibit lower concentrations of plasma pyridoxal 5'-phosphate (PLP), which is derived primarily from liver. To determine the biochemical basis for this abnormality, the enzymes of vitamin B6 metabolism--pyridoxal kinase, pyridoxine (pyridoxamine) 5'-phosphate oxidase, PLP phosphatase(s), and pyridoxal oxidase(s)--were analyzed in liver. The activities of the two biosynthetic enzymes, pyridoxal kinase and pyridoxine (pyridoxamine) 5'-phosphate oxidase were similar for both. The phosphatase activities were significantly higher (mean +/- SD of 9.55 +/- 8.03 versus 3.97 +/- 2.36 nmol X min X mg protein, p less than 0.05) for cirrhotics. Pyridoxal oxidase activities appeared slightly lower for cirrhotics. There was considerable variation in many indices of liver function, which suggests that the defects contributing to altered vitamin B6 metabolism may be complex and individualistic. These analyses have shown that cirrhotics are capable of apparently normal PLP synthesis and that increased hepatic dephosphorylation may be responsible for low levels of plasma PLP.     

Biological markers reflecting peripheral effects of thyroid hormones in autonomous thyroid adenoma

In some patients with functioning thyroid autonomous nodules preclinical hyperthyroidism is detected. It is important to know, whether in this intermediate clinical state beside the suppression of pituitary TSH secretion other target organs are also affected by serum free-thyroxine and free-triiodothyronine levels still within the normal range. Determining some sensitive, but not specific biologic markers reflecting the impact of thyroid hormones at the peripheral tissue level, it was demonstrated that in the group of preclinical hyperthyroidism the mean level of plasma fibronectin exceeded that of the controls (mean +/- S. D.: 583.5 +/- 163.9 vs. 424.2 +/- 84.1 micrograms/ml, p less than 0.001), serum procollagen-III-peptide concentration was already significantly raised, though its value was still within the normal range (mean +/- S. D.: 0.73 +/- 0.17 vs. 0.57 +/- 0.16 U/ml, p less than 0.05), conversely, mean sex-hormone binding globulin level was the same as in euthyroid controls (mean +/- S. D. 47.4 +/- 18.2 vs. 48.3 +/- 16.3 nmol/l). The value of all three parameters was significantly elevated in patients with toxic nodular goiter. Based on the results of this study "tissue"-thyrotoxicosis is suspected in some patients with preclinical hyperthyroidism, which may have therapeutical implications.     

Dietary and biochemical indices of nutritional status in male athletes and controls.

To determine whether physical exercise affects biochemical indices of nutritional status, we compared four groups of male athletes (total n = 427) with two control groups (n = 150). Data about their nutrient intake for 1 month were obtained from a 122-item food frequency questionnaire. An estimate for leisure energy expenditure (EE) was calculated from a 15-item physical activity questionnaire. Athletes were grouped according to their EE (ModEE and HighEE athletes) and weight (light = less than 75 kg; heavy = greater than or equal to 75 kg), and controls according to their weight. Mean energy intake in ModEE and HighEE athletes was 2805-3260 kcal/day. Leisure EE significantly (p less than 0.0001) affected energy and nutrient intakes. Energy, riboflavin and calcium intakes were also higher in heavy subjects (P = 0.0006-0.03). The estimated percentage of subjects with deficient dietary intakes, calculated from probability analyses, was 0-6, depending on group and nutrient. Erythrocyte transketolase activation coefficient (E-TKAC) was highest in controls (1.17 +/- 0.0008; p = 0.001). Serum magnesium was highest (p = 0.01) in ModEE athletes (0.85 +/- 0.006 mmol/L). No intergroup differences were found for plasma ascorbic acid, serum zinc or serum ferritin concentration, whereas blood hemoglobin was lowest (p less than 0.001) in HighEE athletes (149 +/- 0.5 g/L). Ten percent of the control subjects had E-TKAC greater than 1.24. Percentage of other values outside reference range was 0-4, depending on group and indicator. Since lowered blood hemoglobin concentration can be explained by hemodilution, we conclude that sports training did not have a negative effect on biochemical indices of thiamin, vitamin C, magnesium, iron, or zinc status in Finnish male athletes.     

Relationships of nutrient intake and lifestyle-related factors to serum folate and plasma homocysteine concentrations in 30-69 year-old Japanese

We studied non-hospitalized 30-69 y-old Japanese subjects to ascertain the influences of a 677C-T methylene-tetrahydrofolate reductase (MTHFR) genotype, nutritional intake and lifestyle-related factors on plasma homocysteine (Hcys) and serum folate concentrations. Hcys was higher and serum folate was lower in males than in females (p < .01). The Hcys concentration was higher in the VV group than in the AA and AV groups for both males and females. However, a relatively low serum folate concentration of 18 +/- 7 nmol/L was found in the entire male group as compared with 22 +/- 10 nmol/L in all females. In the female subjects, serum folate concentrations differed among MTHFR genotypes, being lowest in the VV group. In all male subjects, log folate intake per 1,000 kcal was a significant positive predictor of log serum folate concentration (p < 0.01), while in females the log vitamin C intake per standard body weight was a significant positive variable (p < 0.001) predicting the log serum folate concentration. Smokers had significantly lower serum folate concentrations, regardless of dietary folate intake. High folate and vitamin C consumptions, appears to be beneficial to normal and heterozygous MTHFR genotype subjects for maintaining serum folate concentrations. Even a 400 microg daily intake of folate might be less than what is needed, especially for homozygous MTHFR subjects and smokers, to maintain an adequate serum folate concentration.     

Red blood cell uptake of supplemental folate in patients on anticonvulsant drug therapy

A group of epileptics (n = 18) and a control group (n = 10) of subjects aged 21-42 y were given 1-mg supplements of folate daily for 1 mo. Anticonvulsant therapy involved phenytoin alone or in combination with phenobarbital. Serum and red blood cell (RBC) folate levels were determined on days 1, 14, and 28. Mean serum and RBC folate levels were greater (p less than 0.05) for the control subjects compared with the epileptic subjects throughout the study. The percent increase in either serum or RBC folate was not different (p greater than 0.05) between the groups. The percent increase in serum folate when expressed as a percent of RBC folate was greater (p less than 0.05) for those epileptics who initially had deficient blood folate levels (serum folate less than 7 nmol/L; RBC folate less than 317 nmol/L) than those who did not. Deficient epileptics may have had an impaired RBC incorporation of circulating (serum) folate compared with nondeficient epileptics.     

Short- and long-term effects of acetaldehyde on plasma.

The effect of low concentrations of acetaldehyde on activated partial thromboplastin time (APTT) and prothrombin time (PT) of Accuclot coagulation plasmas was monitored over a prolonged time to mimic effects observed in alcoholism. A prolongation of the APTT from 31.9 +/- 0.7 s to 32.6 +/- 0.9 s (n = 8; P =.007) was observed after a 30-min preincubation time with 140 microM acetaldehyde. However, a minimum of 3.6 mM acetaldehyde was required to extend the APTT from 36.6 +/- 1.0 s to 41.2 +/- 0.8 s (P =.001) over an 18-h exposure time. Plasma acetaldehyde levels as low as 2.24 mM caused elevation of PTs from 12.5 +/- 0.5 s to 14.4 +/- 0.2 s (P =.005) after a 24-h preincubation time. These findings seem to indicate that short-term contact of acetaldehyde with plasma, probably yielding reversible interactions, may interfere with APTTs to a greater extent than long-term contact, which would presumably yield stable, irreversible interactions. In comparing the effects of 8.94, 17.9, 89.4, and 447 mM acetaldehyde on the PTs of Level I, II, and III plasma, the PTs were most increasingly prolonged in Level III plasma and least prolonged in Level I plasma at each acetaldehyde concentration, although the plasmas have comparable protein concentrations. These findings seem to indicate that coagulation factors are sensitive to inactivation by acetaldehyde.     

Relationship between maternal and neonatal vitamin B6 metabolism: perspectives from enzyme studies.

Enzymes involved in vitamin B6 metabolism, i.e., pyridoxal kinase, pyridoxamine (pyridoxine) 5'-phosphate oxidase, and pyridoxal 5'-phosphate phosphatase, were assayed in hemolysates prepared from cord, maternal, and control blood samples. Mean cord and control pyridoxamine (pyridoxine) 5'-phosphate oxidase activities were significantly higher than maternal activities (p less than 0.001 and p less than 0.05, respectively). A significant correlation (p less than 0.001) was observed between maternal and cord vitamin B6-metabolizing enzymes. Cord pyridoxal 5'-phosphate levels correlated significantly with maternal pyridoxal 5'-phosphate levels (p less than 0.001) and with cord pyridoxal kinase activity (p less than 0.05). Maternal pyridoxal 5'-phosphate levels appear to be the most important factor determining fetal vitamin B6 status.     

Rapid association of acetaldehyde with hemoglobin in human volunteers after low dose ethanol

A fluorigenic high performance liquid chromatographic (HPLC) method was used to determine plasma (PA) and hemoglobin-associated (HbAA) acetaldehyde levels following a pulse of 0.3 g/kg ethanol to volunteers from whom bloods were drawn serially for 8 hours on the clinical research unit. On discharge from the research unit, the volunteers were instructed to avoid ethanol for 28 days. The results were compared to previously published results in teetotalers and alcoholic individuals reporting for treatment at an inpatient detoxification facility. Following ethanol ingestion, the peak levels of ethanol and both plasma and hemoglobin-associated acetaldehyde were detected at the 30 min time point and plasma levels were less than those associated with hemoglobin (31 +/- 16 S.D. and 159 +/- 48 S.D. nmol/g respectively, p less than 0.001). PA and HbAA returned to baseline values following ethanol ingestion within 3.5 hours. PA returned to within 1 standard deviation of levels found in teetotalers by 5 days, whereas HbAA remained elevated for the 28 days of the study. These data provide evidence that measurement of PA and HbAA may provide a useful marker for relatively acute and chronic ethanol ingestion respectively.     

Long-term parenteral nutrition in unrestrained nonhuman primates: an experimental model

A freely mobile jacket and tether system was developed for the investigation of total parenteral nutrition (TPN)-induced metabolic bone disease and complications of prolonged TPN in 12 Macaca fascicularis nonhuman primates. The animals received TPN for 49 +/- 7 d (means +/- SEM), providing 82 +/- 2 kcal.kg-1.d-1. Serum glucose increased from 3.6 +/- 0.2 mmol/L at baseline to 8.3 +/- 1.9 mmol/L (p less than 0.01) during TPN, and serum albumin decreased from 38 +/- 1 g/L at baseline to 29 +/- 1 g/L (p less than 0.001) during 2.75% amino acid TPN and 30 +/- 2 g/L (p less than 0.01) during 5% amino acid TPN infusion. No significant changes were seen in serum prealbumin, total protein, bilirubin, alanine aminotransferase, and 5'-nucleotidase during TPN infusion. Major complications included catheter sepsis, hyperglycemia, diarrhea, and premature death in six animals. Thus, metabolic complications of prolonged TPN support may be investigated in a freely mobile nonhuman primate.     

Selenium deficiency in the acquired immunodeficiency syndrome

Severe protein-calorie malnutrition is common in patients with AIDS (acquired immunodeficiency syndrome). These nutritional deficits are likely to further impair immune responses and other organ functions vital for recovery from serious infectious diseases. Since selenium deficiency is known to be associated with oral candidiasis and abnormal phagocytic function in animals and depressed helper T-cell numbers in man, we evaluated both selenium status and other nutritional parameters in 12 patients with AIDS compared to 27 healthy controls. Selenium was measured by a spectrofluorometric method. The mean (+/- SD) plasma selenium level in AIDS was 0.043 +/- 0.01 microgram/ml vs 0.095 +/- 0.016 microgram/ml in controls (p less than 0.001). Whole blood selenium and red blood cell selenium levels were also significantly reduced in AIDS (p less than 0.005). The mean weight loss in AIDS patients was 35.5 +/- 21.2 pounds. Serum albumin was significantly (p less than 0.01) lower in AIDS patients compared to controls. A good correlation between serum albumin and plasma selenium was noted (r = 0.77; p less than 0.001). We conclude that selenium deficiency is a common component of the malnutrition seen in AIDS patients. Therefore, aggressive nutritional support, including attention to selenium status, should be considered an integral part of the therapy of AIDS patients.     

Biochemical evidence suggestive of suboptimal zinc and vitamin A status in schoolchildren in northeast Thailand

Data are accumulating that support the hypothesis that inadequate zinc nutriture will result in an impairment of vitamin A utilization. Therefore, zinc and vitamin A status were assessed in 283 schoolchildren aged 7-13 y in Northeast Thailand. More than one-fourth had serum vitamin A concentrations less than 0.86 mumol/L , with a mean (+/- SD) concentration of 1.06 +/- 0.31 mumol/L compared with 1.26 +/- 0.02 mumol/L for US children of similar age. Seventy percent had low serum zinc concentrations, less than 10.7 mumol/L. Twenty-three percent of the children exhibited both low serum zinc and vitamin A concentrations. The mean concentration of retinol-binding protein (RBP) was lower for children in this study compared with healthy Thai children in Bangkok, 22.5 +/- 6.6 vs 25.3 +/- 6.0 mg/L, respectively. Serum zinc and RBP were significantly correlated (p less than 0.001) whereas vitamin A and zinc were not correlated. These data suggest that a high proportion of rural schoolchildren in Northeast Thailand are at risk of inadequate zinc and/or vitamin A nutriture.     

The effect of 15-hour fat infusions of varying dosage on bilirubin binding to albumin

Intravenous fat emulsions (1, 2, and 3 g/kg) were administered over 15 hr to 20 appropriate for gestational age premature infants with physiologic hyperbilirubinemia to determine the effect of fat infusions on the serum free fatty acid:albumin molar ratio (F/A) and on unbound bilirubin. Significant increases (p less than 0.05) in F/A occurred with each increase in lipid dose in infants less than 30 wk gestation, but not in infants greater than or equal to 30 wk gestation. There was a direct linear correlation (r = 0.65, p less than 0.001) between F/A ratio and unbound bilirubin (estimated fluorometrically by the ratio of albumin-bound bilirubin/reserve bilirubin binding capacity, B/R). The largest increases in unbound bilirubin (albumin-bound bilirubin/reserve bilirubin binding capacity) were seen in infants with F/A greater than 4.0. The gestational age of infants with F/A greater than 4.0 was significantly less (p less than 0.01) than infants with F/A less than 4.0 (28.7 +/- 0.47 vs. 31.1 +/- 0.40 wk, mean +/- SEM). In 10/58 infusions there was a fall in unbound bilirubin, unrelated to birthweight, gestational age, postnatal age, however, during these infusions the end-infusion F/A was greater than or equal to 3.0. We conclude that 1 g/kg of lipid emulsion infused over a 15-hr period has minimal risk of decreasing bilirubin binding in premature infants less than 30 wk gestation. As doses of 2 or 3 g/kg are used, these infants may be at risk of decreased bilirubin binding, due to elevations in the F/A ratio. Monitoring of the F/A ratio may identify infants at risk for decreased bilirubin binding during lipid infusion and provide guidelines for determining the appropriate lipid dose.     

Improved method for acetaldehyde in plasma and hemoglobin-associated acetaldehyde: results in teetotalers and alcoholics reporting for treatment

A fluorigenic high performance liquid chromatographic (HPLC) assay for the determination of acetaldehyde in plasma and hemoglobin-associated acetaldehyde is described. The assay is based on the reaction of acetaldehyde with two molecules of 1,3-cyclohexanedione in the presence of ammonium ion to form a fluorescent species followed by reverse phase HPLC separation of specific aldehyde derived compounds. The assay is specific; and has sensitivity in the picomole range, with intraassay precision of less that 3.5% and interassay precision of less than 15%. The total run time is less than 6 minutes on HPLC. Hemoglobin-associated acetaldehyde levels were higher than the levels found in plasma. Endogenous levels of acetaldehyde in samples obtained from teetotalers were found to be 0.43 +/- 0.04 (S.D.) microM in plasma and 74.2 +/- 16.1 nmol/g protein as hemoglobin-associated acetaldehyde. The levels of both plasma acetaldehyde and hemoglobin-associated acetaldehyde were significantly higher in patients reporting to a center for alcohol treatment than the levels encountered in teetotalers.