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Biomedical subjects

J Hessels

Publications and source records attributed to J Hessels.

9 recordsLinked to original sources
PubMed2004

Homozygous acute intermittent porphyria in a 7-year-old boy with massive excretions of porphyrins and porphyrin precursors.

A 7-year-old boy demonstrating hepatosplenomegaly, mild anaemia, mild mental retardation, yellow-brown teeth and dark red urine had excessively elevated levels of urinary delta-aminolevulinic acid, porphobilinogen and uroporphyrin. Furthermore hepta-, hexa-, penta- and copro(I)porphyrins were highly increased in urine. This pattern of porphyrin precursor and metabolite excretion is characteristic of acute intermittent porphyria. The decreased copro(III)/copro(I+III) ratio, normally not found in acute intermittent porphyria, is discussed. The porphobilinogen deaminase activity in red cells was decreased to 2-4%. Mutation analysis revealed a novel homozygous L81P mutation in exon 6 of the porphobilinogen deaminase gene. The father and mother, shown to be gene carriers of the same mutation, are asymptomatic and have normal urinary porphyrin precursor and metabolite excretion.

Child↗
PubMed1995

Investigation of polyamine metabolism by high-performance liquid chromatographic and gas chromatographic profiling methods.

Measurements of polyamines, polyamine conjugates and their metabolites in tissues, cells and extracellular fluids are used in biochemistry, (micro)biology, oncology and parasitology. Decarboxylation of ornithine yields putrescine. Aminopropylation of putrescine yields spermidine, and aminopropylation of spermidine yields spermine. Spermidine and spermine are retroconverted to putrescine and spermidine, respectively, by initial N-acetylation and subsequent polyamine oxidation. The intermediate N-acetylputrescine, N1-acetylspermidine and N8-acetylspermidine are the major urinary N-acetylpolyamines. Polyamines and N-acetylpolyamines are terminally degraded to non-alpha-amino acid metabolites by oxidative deamination and aldehyde dehydrogenation. Chromatography with on-line detection is the most commonly applied profiling method for polyamines, N-acetylpolyamines and their non-alpha-amino acid metabolites. Cation-exchange and reversed-phase high-performance liquid chromatography require pre- or post-column derivatisation, followed by UV-Vis spectrophotometric or fluorimetric detection. Isolation and derivatisation precedes gas chromatography with flame-ionisation, nitrogen-phosphorus, electron-capture or mass spectrometric detection. High-performance liquid chromatography and gas chromatography of polyamines are not competitive techniques, but rather supplementary.

Chromatography, Gas↗
PubMed1991

Growth inhibition of two solid tumors in mice, caused by polyamine depletion, is not attended by alterations in cell-cycle phase distribution.

We studied the effect of polyamine depletion on growth and cell cycle characteristics of subcutaneously grown Lewis lung carcinoma (LLC) and fibrosarcoma (FIO 26) in mice. Polyamine depletion was achieved by inhibition of ornithine decarboxylase using 2-(difluoromethyl)ornithine, limitation of exogenous polyamines by administration of a polyamine-poor diet and decontamination of the gastrointestinal tract, and inhibition of endogenous polyamine reutilization by N,N'-bis-(2,3-butadienyl)putrescine (MDL 72527). Determination of S-phase cells was performed in tumor-cell suspensions by flow cytometry and in tumor tissue sections by microscopy, following in vivo labelling with 5-bromo-2'-deoxyuridine (BUdR). DNA synthesis rate was estimated from the incorporation of in vivo-injected [3H]-thymidine (3H-TdR). Both solid tumors almost completely stopped growing after access to polyamines was blocked. Growth inhibition was, however, not attended by changes in cell-cycle-phase distribution. Paradoxically, we measured increased in vivo 3H-TdR incorporation rates and unaltered BUdR-linked staining intensity in treated tumors. Injection of putrescine into treated LLC-bearing mice resulted in an increase in intracellular putrescine and spermidine concentrations, a slight increase in the number of S-phase cells and a marked drop in DNA synthesis rate within the following 9 hr.

Animals↗
PubMed1991

Gas chromatographic determination of N-acetylisoputreanine-gamma-lactam, a unique catabolite of N1-acetylspermidine.

A capillary gas chromatographic method with nitrogen-phosphorus detection for the determination of N-acetylisoputreanine-gamma-lactam (acisoga) in urine is described. The method was validated by comparing the results with those given by an isotope dilution mass fragmentographic method. Making use of specific inhibitors for copper-dependent amine oxidase and polyamine oxidase in rats, it was demonstrated that acisoga is formed by oxidative deamination of N1-acetylspermidine by the former enzyme. Moreover, acisoga is not a substrate for pig liver polyamine oxidase. Increased concentrations of acisoga, relative to N1-acetylspermidine, in urines of patients with non-Hodgkin's lymphoma indicated that this conversion diminishes the sensitivity of N1-acetylspermidine as a marker for (tumour) cell death.

Animals↗
PubMed1990

Inhibition of polyamine oxidase in rats improves the sensitivity of urinary polyamines as markers for cell death.

In this study we investigated polyamine metabolism during inhibition of two polyamine-catabolizing enzymes. This was performed by treating rats with aminoguanidine [an inhibitor of Cu-dependent amine oxidase (CuAO)], NN'-bis(buta-2,3-dienyl)butane-1,4-diamine [MDL 72527, an inhibitor of FAD-dependent polyamine oxidase (PAO)], tetrachloromethane (hepatotoxic agent) and combinations of these compounds. Emphasis was laid on the origin and possible clinical usefulness of two polyamine metabolites: acetylisoputreanine-gamma-lactam and N1N12-diacetylspermine. Acetylisoputreanine-gamma-lactam is a normal constituent of human and rat urine. Treatment of rats with aminoguanidine led to undetectable urinary levels of acetylisoputreanine-gamma-lactam, whereas MDL 72527 treatment resulted in a 12-fold increase. Under normal conditions this compound represents a minor CuAO catabolite of N1-acetylspermidine, but may become of more importance under CuAO-induced conditions. N1N12-diacetylspermine was undetectable in urine samples from non-pregnant adults and rats, but became detectable after treating rats with MDL 72527. Additional tetrachloromethane poisoning resulted in a 35-fold increase of N1N12-diacetylspermine in urine and its appearance in liver. Hence urinary excretion of N1N12-diacetylspermine during PAO inhibition may serve as a sensitive marker for cell death. This was confirmed by myeloid-leukaemia-bearing rats treated with MDL 72527, which also excreted N1N12-diacetylspermine in urine in relatively high amounts from at least day 14 until spontaneous death.

Animals↗
PubMed1989

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.

Animals↗
PubMed1989

Microbial influences on urinary polyamine excretion.

We determined diamines, polyamines, their monoacetylated conjugates and some of their catabolites in urines of healthy persons during decontamination of the gastrointestinal tract and patients with urinary tract infections. The compounds were also measured after in vitro incubation of urines from healthy persons and patients. During decontamination the urinary excretion of total putrescine decreased by a small amount. This fall was for the greater part accountable to monoacetylated putrescine. Free putrescine levels were increased in urines of patients with urinary tract infections, decreased after therapy, and increased after incubation of the pretherapeutical samples. Total cadaverine decreased during decontamination and increased during recontamination. The changes were partly accountable to monoacetylated cadaverine. Free cadaverine levels of patients with urinary tract infections were normal and did not change after therapy. These data show that, under normal conditions, a small part of monoacetylated putrescine and a considerable part of monoacetylated cadaverine originate from the gastrointestinal tract, and that urinary tract infections lead to an increase of free putrescine. The microbial synthesis of putrescine in the gastrointestinal- and urinary tracts, should therefore be taken into account for the interpretation of urinary putrescine levels as a parameter for body cell turnover.

Adult↗
PubMed1985

Inhibition of carbonic anhydrase in dog plasma.

Using a pH stat method, we measured the activity of carbonic anhydrase (CA) from dog erythrocytes in the presence of various amounts of dog plasma. A plasma factor appeared to be able to inhibit about 86% of the total CA activity, corresponding to the relative activity of CA II. Naiodoacetate was shown to inhibit the total CA activity up to about 13%, corresponding to the relative activity of CA I. C1- inhibited the total CA activity up to about 20%, presumably mainly through its strong influence on Ca I. It is concluded that with a degree of haemolysis of up to 3%, no appreciable plasma CA activity will occur.

Animals↗