A qualitative gas chromatographic analysis of substituted 5,6-dihydroxyindoles from the urine of patients with melanoma

A qualitative gas chromatographic analysis of trimethylsilylated ethyl acetate extracts of melanotic urine revealed 5 indolic compounds, which have been identified as substituted 5,6-dihydroxyindoles. Ethyl acetate extracts of melanotic urines at pH 2.0 contained isomeric 5-hydroxy-6-methoxy and 6-hydroxy-5-methoxy-indolyl-2-carboxylic acids which were not separable under the conditions used. A careful hydrolysis of melanotic urine with a Helix pomatia preparation followed by extraction at pH 6.5 in a nitrogen atmosphere released 3 additional indolic compounds from their conjugated form. Using gas chromatographic-mass spectrometric analysis they were identified as 5-hydroxy-6-methoxy, 6-hydroxy-5-methoxyindole and 5,6-dihydroxyindole.     

Effects of malnutrition on the erythrocyte fatty acid composition and plasma vitamin E levels of Pakistani children

Abstract Erythrocyte fatty acids and plasma vitamin E concentrations were determined in 47 grade 2 and 21 grade 3 malnourished Pakistani children (ages 4–56 months). Data were compared with those of 26 age- and sex-matched apparently healthy controls. Evaluation with three statistical approaches revealed that both grade 2 and grade 3 malnourished children had decreased erythrocyte ω6 fatty acids and to a lesser extent decreased ω3 fatty acids. These decreases were compensated for by increased ω9 fatty acids. The patients tended to have lower plasma vitamin E concentrations. We conclude that malnourished Pakistani children have low essential fatty acid status, notably those of the ω6 series. The combination of low erythrocyte 22:6ω3 and a low 22:5ω6/22:4ω6 ratio in grade 2 patients suggests low Δ4-desaturation activity, which may be due to impaired peroxisomal β-oxidation.     

Microbial flora in the gastrointestinal tract abolishes cytostatic effects of alpha-difluoromethylornithine in vivo

Although treatment with the ornithine decarboxylase inhibitor alpha-difluoromethylornithine (DFMO) leads to depletion of intracellular polyamines and to related growth inhibition in vitro, its cytostatic effects in vivo are disappointing. This may be due to abolition of DFMO-induced growth inhibition by polyamines released during normal body cell turnover, to dietary polyamines, or to putrescine synthesized by the microbial flora in the GI tract. We studied selectively (aerobic) and totally (aerobic + anaerobic) GI tract-decontaminated LI210-bearing mice fed with 3 types of diet differing in their polyamine and carbohydrate residue contents and treated with combinations of intraperitoneal DFMO and oral deuterium-labelled putrescine. Our data show that, irrespective of diet type, total decontamination markedly potentiates the moderate tumor growth inhibition that is caused by DFMO alone. During total decontamination, growth-inhibited L1210 cells accumulate in the G0/G1 phase of the cell cycle. Although orally administered deuterium-labelled putrescine gave rise to deuterium labelling of L1210 putrescine, spermidine and spermine, the polyamine levels in our diets played only a minor role.     

Meta-[I-131]iodobenzylguanidine uptake in a nonsecreting paraganglioma

In a patient with a paraganglioma at the carotid bifurcation, intense uptake of meta-[I-131]iodobenzylguanidine (I-131 MIBG) in the tumor was found. There was no clinical or biochemical evidence for catecholamine secretion by the tumor, although analysis of the tissue revealed that catecholamine biosynthesis took place. We conclude that accumulation of I-131 MIBG may occur in a paraganglioma, but does not necessarily indicate endocrine activity of the tumor.     

STUDIES ON THE PRIMARY STRUCTURE OF BISON PANCREATIC RIBONUCLEASE

Bison pancreatic ribonuclease was isolated by affinity chromatography. Thermolysin and tryptic digestion of denaturated protein, and subtilisin digestion of native protein yielded peptides, which were purified and submitted to amino acid analysis. These peptides, together with partial sequence data obtained by Stewart & Stevenson (16) overlap the entire amino acid sequence of bison ribonuclease. No differences with bovine ribonuclease were found, although there may be differences in state of amidation of some residues.     

Predictive value of cord blood hematological indices and hemoglobin Barts for the detection of heterozygous alpha-thalassemia-2 in an African-Caribbean population.

BACKGROUND: Cord blood hemoglobin Barts (HbBarts) and hemocytometric indices may be used for classification of newborns into those without alpha-thalassemia-2 (alphaalpha/alphaalpha) and with heterozygous alpha-thalassemia-2 (-alpha(3.7)/alphaalpha). We investigated by logistic regression analysis whether the combination of HbBarts and hemocytometric indices improves classification compared with classification based on a single analyte. METHODS: HbBarts percentages and hemocytometric indices were determined in cord blood of 208 consecutive newborns in Cura?ao (Netherlands Antilles). Of these, 157 had alphaalpha/alphaalpha and 51 had -alpha(3.7)/alphaalpha, as established by DNA analysis. RESULTS: Between-group differences were significant for erythrocytes, mean cell volume, mean cell hemoglobin (MCH), mean cell hemoglobin concentration, platelets, hemoglobin F(0) (HbF(0)), and HbBarts. The Logit equation of the logistic regression model, using MCH (pg) and HbBarts (%), was: 42.7164 + 5.7916(HbBarts) - 1.3110(MCH). A sensitivity of 100% was reached at a Logit value of -3.70. The corresponding specificity was 62.2%, and the predictive value of a positive test (PV+) was 46.3% (95% confidence interval, 37.0-55.7%). The relative information gains were as follows: 88% for the HbBarts-MCH combination, 26% for MCH (not significant), and 0% for HbBarts compared with the 24.6% -alpha(3.7)/alphaalpha prevalence. CONCLUSION: Combined use of cord blood HbBarts and MCH improves classification compared with classification based on single hemocytometric indices.     

Low erythrocyte docosahexaenoic acid in malnourished, often breast-fed, Pakistani infants: a matter of concern?

This article provides valuable information on the importance of long-chain polyunsaturated fatty acids (LCPUFAs) for the development of the central nervous system, including visual acuity. It was believed that breast milk contains a large range of LCPUFAs, including docosahexaenoic (DHA) and arachidonic acids which cannot be found in formula milks for term infants; but low RBC LCPUFAs have been observed in malnourished children receiving breast milk and weaning food low in fat. In these children, it has been postulated that the synthesis of LCPUFAs from their precursors is decreased making them more dependent on an adequate LCPUFA intake. Several studies were conducted to test this hypothesis. It was observed that although malnourished children in North Pakistan received breast milk, yet poor DHA status of these malnourished breastfed children is caused by a marginal DHA status of these mothers. Further studies are needed though to establish the relationship between maternal nutrition during lactation and children RBC DHA levels receiving breast milk.     

Breast milk docosahexaenoic acid (DHA) correlates with DHA status of malnourished infants.

AIM: To investigate whether low docosahexaenoic acid (22:6omega3; DHA) status of malnourished, mostly breast fed infants is a result of low omega3 fatty acid intake via breast milk. METHODS: Fatty acid composition of breast milk of eight Pakistani mothers, and of the erythrocytes of their malnourished children was analysed. RESULTS: The milk of the Pakistani mothers contained low percentages of all omega3 and most omega6 fatty acids, compared with milk of Dutch mothers. Breast milk DHA was positively correlated with infant erythrocyte DHA and arachidonic acid (20:4omega6). CONCLUSION: DHA status of these malnourished children is strongly dependent on the omega3 fatty acid intake from breast milk. Augmentation of the infants' omega3 long chain polyunsaturated fatty acid status, or the omega3 and omega6 fatty acid status in general, by supplementation is indicated in deprived circumstances where access to fresh fish is difficult. However, in terms of prevention, maternal supplementation of these long chain polyunsaturated fatty acids, preferably from early pregnancy onwards, may be a better option.     

Elevated homocysteine levels indicate suboptimal folate status in pediatric sickle cell patients

We investigated whether pediatric patients with sickle cell disease (SCD) (9 + 4 years; 27 homozygous SCD [HbSS]; 19 sickle-C disease [HbSC]) have different folate status compared with age-, sex-, and race-matched normal hemoglobin (HbAA) controls (n = 20), and whether their folate status can be improved by folate supplementation. The patients were supplemented with vitamins B₆ and B₁₂ during one week and with folate during the following week. Circulating folate, homocysteine, vitamin B₆ and vitamin B₁₂ levels were measured at baseline (patients and controls), after one week and after two weeks (patients). The patients had similar folate, vitamin B₆, and vitamin B₁₂, but higher homocysteine levels compared with HbAA controls (12.7 + 4.5 vs. 10.9 + 3.5 μmol/l; P = 0.04). Vitamin B₆ and B₁₂ supplementation did not change their homocysteine levels, but folate supplementation caused a 53% reduction (to 5.7 + 1.6). We conclude that patients with SCD have adequate vitamin B₆ and B₁₂ status, but suboptimal folate status, leading to elevated plasma homocysteine levels. They may therefore benefit from folate supplementation to reduce their high risk for endothelial damage. Am. J. Hematol. 59:192–198, 1998. © 1998 Wiley-Liss, Inc.