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Biomedical subjects

F A Muskiet

Publications and source records attributed to F A Muskiet.

At least 127 records · Page 7Linked to original sources
PubMed1987

Simultaneous quantification of total medium- and long-chain fatty acids in human milk by capillary gas chromatography with split injection.

Four different quantification methods for the capillary gas chromatographic determination of medium-chain fatty acids (6:0-12:0) and myristic acid in human milk samples, using a split injector, were compared. Odd-carbon-numbered fatty acids (5:0-17:0) were added as internal standards. Each medium-chain fatty acid and myristic acid was calculated on the basis of: the peak area of the internal standard with one methylene group less; the peak area of the internal standard with one methylene group more; half the sum of the peak areas of the internal standards with one methylene group less and more (bracketting method); the peak area of 17:0. The peak-area ratio of each analyte and 17:0 in a standard was found to be subject to an unacceptably high coefficient of variation. From the methods using internal standards with one methylene group more and less, the bracketting method was found to be the best, resulting in recoveries close to 100%, with the lowest coefficients of variation. The method was applied for the determination of the fatty acid composition of mature milk samples of 47 Curaçaoan women.

Adolescent↗
PubMed1987

Determination of polyamines in human erythrocytes by capillary gas chromatography with nitrogen-phosphorus detection.

A capillary gas chromatographic method with nitrogen-phosphorus detection is used to determine simultaneously 1,3-diaminopropane, putrescine, cadaverine, spermidine and spermine in human erythrocytes. The compounds are isolated by adsorption on silica and converted into their heptafluorobutyryl derivatives. We give quality-control data and (age-dependent) normal values for 48 apparently healthy controls.

Adult↗
PubMed1987

Rapid changes in serum, plasma and erythrocyte lipid compositions, and serum transaminase levels during continuous enteral hyperalimentation by carbohydrates alone.

Twelve normal men received twice their estimated basal energy requirement by a carbohydrate solution via a nasogastric catheter during 48 hours, followed by a seven-hour fast. Subsequently, in nine of them 0.5 mg epinephrine was given subcutaneously under ongoing fasting. During hyperalimentation, serum triglycerides, phospholipids, total and free cholesterol, phospholipids/free cholesterol ratio, and plasma free fatty acids decreased, whereas the percentage of free cholesterol increased. During fasting and subsequent epinephrine administration triglycerides and free fatty acids rose without reaching basal levels. Plasma and red blood cell (RBC) fatty acid composition already changed from two hours after the start of the feeding. Most markedly, a steady decrease in RBC 18:2c, omega 6, amounting to more than 17% of the basal value at the end of the observation period was found. Neither in plasma, nor in RBC a concomitant appearance of 20:3c, omega 9 was seen. In RBC, the relative amounts of the saturated fatty acids increased, whereas those of monounsaturated and polyunsaturated fatty acids decreased. RBC content of total fatty acids decreased and that of cholesterol increased. The ratios 16:1c, omega 7/16:0 and 18:3c, omega 6/18:2c, omega 6 in plasma, and 20:3c, omega 6/18:2c, omega 6 in plasma and RBC increased, whereas those of 18:1c, omega 7/16:1c, omega 7 and 20:3c, omega 6/18:3c, omega 6 in plasma decreased. After 48 hours feeding serum glutamic pyruvic transaminase and glutamic oxaloacetic transaminase levels were moderately increased and rose further during fasting. Thus, continuous enteral hyperalimentation by carbohydrates alone rapidly induces profound changes in serum-, plasma-, and RBC lipid compositions and serum parameters of hepatic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Comparison of the fatty acid composition of human milk from mothers in Tanzania, Curacao and Surinam.

Fatty acid composition of mature human milk from Curacao (Netherlands Antilles), Surinam and Tanzania was determined by capillary gas chromatography. In the Curacaoan samples the cholesterol and alpha- and gamma-tocopherol concentrations were also determined. Remarkable differences were found in the fatty acid composition of breastmilk fat from the three countries. The differences in the levels of medium chain fatty acids between Curacao and Tanzania, and between Curacao and Surinam were significant. The mean sum of the essential fatty acids linoleic acid and linolenic acid showed the highest values in Curacao (16.1 g per cent). Mean values for Tanzania and Surinam were 14.9 and 12.7, respectively. The mean level of the docosahexaenoic acid was higher in the Curacaoan and Surinam samples compared with that from Tanzania. In the Curacaoan breastmilk samples the concentrations of cholesterol and alpha- and gamma-tocopherol were about twice as high as those reported for Western countries.

Cholesterol↗
PubMed1986

Determination of N-(3-acetamidopropyl)pyrrolidin-2-one, a metabolite of spermidine, in urine by isotope dilution mass fragmentography.

A capillary gas chromatographic method with mass spectrometric detection for the determination of N-(3-acetamidopropyl)pyrrolidin-2-one, the monoacetyl conjugate of isoputreanine-gamma-lactam, in urine has been developed. Using a quantification based on stable isotope dilution mass fragmentography, age-dependent normal values for the urinary excretion of N-(3-acetamidopropyl)pyrrolidin-2-one by 44 apparently healthy control subjects were determined. Quality control data and normal values for 27 adults are given. The method was applied to the monitoring of the chemotherapeutic treatment of two patients with high-grade non-Hodgkin lymphoma.

Adolescent↗
PubMed1986

Determination of pipecolic acid in urine and plasma by isotope dilution mass fragmentography.

A capillary gas chromatographic method with mass spectrometric detection for the determination of pipecolic acid in urine and plasma (or serum) has been developed. Using a quantification based on stable isotope dilution mass fragmentography the concentration of pipecolic acid was determined in urines of 34 healthy children and 8 patients with Zellweger's syndrome. The urinary pipecolic acid excretion of healthy infants decreases with age. Its concentration in urines of patients with Zellweger's syndrome was not consistently elevated. Normal values for pipecolic acid in plasma were established for 19 healthy children. Pipecolic acid concentrations in 47 urine samples (range 0.02-228.3 mmol/mol of creatinine) and 6 serum samples of Zellweger patients after oral loading with DL-pipecolic acid (range 65-1334 mumol/l) were found to correlate satisfactorily with the results obtained by an amino acid analyzer method. The major advantage of the presented method over the amino acid analyzer method concerns its greater sensitivity and its much shorter analysis time.

Abnormalities, Multiple↗
PubMed1986

Capillary gas chromatographic profiling of urinary, plasma and erythrocyte sugars and polyols as their trimethylsilyl derivatives, preceded by a simple and rapid prepurification method.

A capillary gas chromatographic method for the profiling of trimethylsilylated mono- and disaccharides and polyols in urine, plasma and unwashed and washed erythrocytes is described. The prepurification method is based on the moderate inhibition of the derivatization experienced in the presence of physiological amounts of inorganic salts and the relative stability of the formed trimethylsilylethers towards treatment with water and dilute hydrochloric acid. Series to series quality control data for 31 sugars/polyols in a pooled urine are given. The method was used to establish age-dependent concentrations of 18 sugars/polyols in urines of 72 control persons on a free diet. Gas chromatographic profiles and quantitative data obtained from urines of pediatric patients with galactosemia treated with a diet low in lactose and galactose, type 1 hereditary tyrosinemia treated with a diet low in phenylalanine and tyrosine, and a neurological disorder with a high calorie gastric drip feeding, are presented and discussed. Examples of the profiling of sugars/polyols in the plasma, unwashed and washed erythrocytes of a healthy adult, and the plasma of a newborn with galactosemia prior to treatment, are given.

Adolescent↗
PubMed1986

Changes in fatty acid profiles of plasma, erythrocytes and polymorphonuclear leukocytes in induced hypothyroidism in man: indirect evidence for altered delta 6 desaturase activity.

Thirteen patients who were athyreotic as a consequence of ablation treatment for well-differentiated thyroid cancer were studied during triiodothyronine supplementation, and subsequently at the end of a two weeks withdrawal of this medication. Serum and plasma lipid concentrations, erythrocyte cholesterol content and plasma and erythrocyte total fatty acid patterns were measured. In addition, total fatty acid profiles of polymorphonuclear leukocytes of eight patients and scanning electron microscopic studies of erythrocytes of nine patients were made. We observed an increase of the serum concentrations of total and unesterified cholesterol and phospholipids in all patients. Except for two, all patients showed an increase in the serum triglyceride concentration. The relative amounts of 18:2c,omega 6 rose and those of 20:3c,omega 6 fell in all studied compartments. In addition, the relative amounts of all other omega 6 fatty acids, 22:6c,omega 3, 20:3c,omega 9, 16:0, 18:0, and total saturated fatty acids decreased in plasma, whereas the levels of all monounsaturated fatty acids increased in the erythrocytes. The level of 20:3c,omega 9 rose in the erythrocytes and the 20:3c,omega 9/20:4c,omega 6 ratio rose in the polymorphonuclear leukocytes. The erythrocyte total fatty acids and cholesterol content and their ratio did not change, nor was any alteration seen in the red cell morphology by scanning electron microscopy. This study reveals that the induction of hypothyroidism in man changes fatty acid patterns of plasma, erythrocytes and polymorphonuclear leukocytes. The nature of these alterations suggests especially a disturbance in the delta 6 desaturase activity. The data point to the possibility of a derangement of eicosanoid synthesis in hypothyroidism.

Adult↗
PubMed1986

Increase of plasma and red cell cholesterol sulfate levels in induced hypothyroidism in man.

Plasma and erythrocyte cholesterol sulfate-, erythrocyte cholesterol-, and serum unesterified- and total cholesterol levels of ten athyreotic thyroid cancer patients were measured during triiodothyronine supplementation, and subsequently at the end of a two weeks withdrawal of this medication. The results showed that in the hypothyroid state all above mentioned parameters increased except for the erythrocyte cholesterol level, which remained unchanged. The interrelationships between these parameters, and the exchange mechanism of cholesterol sulfate between plasma and erythrocytes are discussed.

Adult↗
PubMed1986

Bioavailability of orally administered zinc, using Taurizine.

Zinc aspartate equivalent to 50 mg of elementary zinc, orally administered to seven normal healthy male volunteers in an enteric-coated tablet (Taurizine), gave no significantly increased plasma zinc levels, neither when this drug was taken in a fasting state nor during a lunch. The formulation of this tablet seems to obstruct the absorption of zinc.

Adult↗
PubMed1986

Eumelanin-related indolic compounds in the urine of treated melanoma patients.

A method was developed for the quantitation of six eumelanin-related indolic compounds in urine. The procedure employs methane ionization of the hexafluoroisopropyl and/or pentafluoropropionyl derivatives of 5,6-dihydroxyindole, 5-hydroxy-6-methoxyindole, 6-hydroxy-5-methoxyindole, 5-hydroxy-6-methoxyindolyl-2-carboxylic acid, 6-hydroxy-5-methoxyindolyl-2-carboxylic acid and 5,6-dimethoxyindolyl-2-carboxylic acid together with their deuterated analogues, and selected ion-monitoring. Deuterated analogues are added as internal standards to enzymatically hydrolysed urine before diethyl ether extraction. The method was used for monitoring urinary excretion in patients with malignant melanoma treated with cytostatics. In several cases, a decrease of the excretion of the eumelanin-related substances was recorded after the therapy. The usefulness of the individual indolic compounds for such follow-up studies is discussed.

Gas Chromatography-Mass Spectrometry↗
PubMed1986

Simultaneous gas-chromatographic determination of free and acetyl-conjugated polyamines in urine.

A capillary gas-chromatographic method with nitrogen-phosphorus detection is used to determine simultaneously urinary 1,3-diaminopropane, monoacetyl-1,3-diaminopropane, putrescine, monoacetylputrescine, cadaverine, monoacetylcadaverine, spermidine, N1-acetylspermidine, N beta-acetylspermidine, spermine, N1-acetylspermine, isoputreanine, N-(3-aminopropyl)pyrrolidin-2-one, and putreanine. The compounds are isolated by adsorption onto silica and converted into their methyl-heptafluorobutyryl derivatives. We give quality-control data and age-dependent "normal" values for urinary excretion of these analytes from 51 apparently healthy control subjects. Normal values for 31 adults are compared with those reported in the literature. Monoacetyl-1,3-diaminopropane and N1-acetylspermine are identified by mass fragmentography. We applied the method to monitor chemotherapeutic treatment of a patient with advanced non-Hodgkin's lymphoma; we identified by mass spectrometry N1,N12-diacetylspermine in this patient's urine.

Acetylation↗
PubMed1985

Mass fragmentographic identification of polyamine metabolites in the urine of normal persons and cancer patients, and its relevance to the use of polyamines as tumour markers.

The mass fragmentographic identification of N-(2-carboxyethyl)-4-amino-n-butyric acid, N-(3-aminopropyl)-N1-(2-carboxyethyl)-1,4-diaminobutane, N,N1-bis(2-carboxyethyl)-1,4-diaminobutane, and delta-aminovaleric acid in acid-hydrolysed urines of a normal person and two cancer patients is described. A previous study, in which the metabolic fate of intraperitoneally injected polyamines in rats was investigated, revealed that these compounds should be considered as non-alpha-amino acid metabolites of the naturally occurring polyamines. Quantification of polyamines and their non-alpha-amino acid metabolites by gas chromatography with nitrogen--phosphorus detection showed that, relative to the parent polyamines, humans normally excrete higher quantities of polyamine catabolites in urine than rats, suggesting that humans catabolize polyamines more efficiently. As illustrated by the follow-up of the concentrations of polyamines and their catabolites in the urine of a patient with high-grade non-Hodgkin lymphoma during chemotherapy, the catabolic pressure on polyamines may be considerably increased during neoplastic diseases, since an even higher proportion of oxidized polyamine metabolites was observed. It is therefore suggested that the additional measurement of the circulating concentrations of polyamine-degrading enzymes is of importance for the correct interpretation of polyamine (metabolite) determinations for oncological purposes.

Amino Acids↗
PubMed1985

A specific and sensitive determination of gamma aminobutyric acid in CSF and brain tissue by gas chromatography-mass spectrometry.

The determination of gamma-aminobutyric acid (GABA) in cerebrospinal fluid and brain extracts is described. Its heptafluorobutyryl-isobutanol derivative was measured both by electron impact and chemical ionization mass fragmentography using GABA-d6 as internal standard. The derivatization product is stable for several days. The method is sensitive (1 ng absolute in cerebrospinal fluid and 30 pg in standard GABA solutions) and specific, when chemical ionization mode is applied. Normal values of GABA are in rat brain extracts (1.40 +/- 0.32 mumol/g fresh weight) and human CSF (18.3 +/- 10.0 ng/ml).

Animals↗
PubMed1984

The plasma and erythrocyte fatty acid composition of poorly controlled, insulin-dependent (type I) diabetic patients and the effect of improved metabolic control.

Analysis of the plasma and erythrocyte fatty acid composition of poorly controlled, insulin-dependent (type I) diabetic patients revealed a low level of 18:3c, omega 6, 20:3c, omega 6, 22:6c, omega 3 and total polyunsaturated fatty acids, and a high level of 18:0 and total saturated fatty acids. Improvement of diabetic control, achieved by treatment with continuous subcutaneous insulin infusion coincided with an increase of arachidonic acid and a normalization of total polyunsaturated fatty acids, with a concomitant decrease of total saturated fatty acids and total monounsaturated fatty acids, especially 18:1c, omega 9. The results of this study can be important for the dietary advice to poorly controlled, diabetic patients.

Adult↗
PubMed1984

Catabolism of polyamines in the rat. Polyamines and their non-alpha-amino acid metabolites.

The metabolic fate of stable isotopically labeled polyamines was investigated after their first and second intraperitoneal injection in rats. Using gas chromatographic and mass fragmentographic analyses of acid-hydrolyzed 24-h urines, some aspects of the polyamine metabolism could be elucidated. After the injections with hexadeutero-1,3-diaminopropane, only labeled 1,3-diaminopropane was recovered from the urine samples. The rat injected with tetradeuteroputrescine excreted labeled putrescine, gamma-amino-n-butyric acid, 2-hydroxyputrescine and spermidine, while the urine samples of the rat after the injections with tetradeuterocadaverine contained labeled cadaverine and delta-aminovaleric acid. The injections of hexadeuterospermidine led to the appearance of labeled spermidine, isoputreanine, putreanine, N-(2-carboxyethyl)-4-amino-n-butyric acid, putrescine, gamma-amino-n-butyric acid, 1,3-diaminopropane, beta-alanine and spermine. After the injections with bis(2-carboxyethyl)-1,4-diaminobutane, spermidine, isoputreanine, putreanine, N-(2-carboxyethyl)-4-amino-n-butyric acid, putrescine, 1,3-diaminopropane, beta-alanine, 2-hydroxyputrescine and possibly gamma-amino-n-butyric acid were recovered. Clear differences between the metabolism after the first and second injection were noted for putrescine, spermidine and spermine, which is suggestive for enzyme induction and/or the existence of salvage pathways.

Animals↗
PubMed1984

Lipids, fatty acids and trace elements in plasma and erythrocytes of pediatric patients with homozygous sickle cell disease.

Plasma and erythrocyte levels of zinc, copper, fatty acids, total cholesterol and cholesterol sulfate, and plasma vitamin E and free cholesterol were measured in six pediatric patients with HbSS sickle cell anemia, one adult patient in crisis and six age-, sex- and race-matched pediatric controls. Patient plasma zinc levels were significantly decreased, while erythrocyte zinc levels were normal. Although subject to a large range, plasma vitamin E levels were not significantly altered. For patients an increased plasma percentage of free cholesterol, increased levels of oleic acid and vaccenic acid, and decreased values for total cholesterol were found. Erythrocyte fatty acid analyses revealed a significant decrease in total polyunsaturated fatty acids which was 'compensated' for by increased total monounsaturated and saturated fatty acids. The low amounts of total polyunsaturated fatty acids could completely be ascribed to decreased levels of linoleic acid. Erythrocyte cholesterol levels were significantly increased, while the total fatty acid/cholesterol molar ratio was found to be subject to a relatively large range. Cholesterol sulfate determinations showed that patients had relatively low plasma or erythrocyte levels, or both. The present results are suggestive of a lipid peroxidation mediated, and hepatic and/or splenic dysfunction mediated lipid component in the rigidification of the sickle cell membrane.

Adolescent↗