Ferritine : onderzoekingen over de opbouw en afbraak van deze stof in verband met zijn functie in het ijzermetabolisme

De duitse farmacoloog Schmiedenberg was de eerste die in 1894 een ijzerhoudend eiwit beschreef dat geïsoleerd was uit varkenslever. Hij noemde dit ferratine. Zijn isolatie methode was echter dusdanig dat het hier geen zuiver eiwit betrof maar een mengsel van eiwitten en nucleïnezuren. In 1909 beschreef Scaffidi de bereiding uit varkenslever van een nucleoproteïne preparaat van de volgende samenstelling: 3, 5% Fe, 3, 3% P. Hierop voortbouwend hebben verschillende onderzoekers getracht om het nucleoproteïne ijzervrij in handen te krijgen, zonder veel succes echter. Een beter inzicht in de aard van het preparaat werd verkregen toen de probleemstelling door Laufberger werd omgedraaid. Deze auteur trachtte de eiwitijzer verbinding van contaminerend nucleïnezuur te bevrijden. Zijn eerste pogingen, waarbij van paardelever werd uitgegaan bleven zonder succes. Pas nadat de paardelever werd vervangen door paardemilt slaagde hij er in een ijzerhoudend eiwit te isoleren dat hij ferritine noemde. Dit ferritine bevatte 20% ijzer, betrokken op drooggewicht en het hoge ijzergehalte bracht Lauiberger er toe te veronderstellen dat ferritine betrokken zou zijn bij de opslag van ijzer in het lichaam. In dit verband was al eerder door Cook en Asher aangetoond dat in geval van snelle hemoglobine destructie in het lichaam. een ijzerhoudend pigment wordt gevormd in beenmerg, milt en lever, gepaard gaande met een ziektebeeld dat bekend staat onder de naam hemochromatosis. Na de publicatie van Laufberger in 1937 duurde het tot 1942 toen Granick de isolatie van ferritine opnieuw ter hand nam en de fysisch-chemische eigenschappen van ferritine aan een nader onderzoek onderwierp

Serum Water Determination by Means of Microwave Evaporation

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Lipid, nitrogen, water and energy content of a single stool sample in healthy children and children with cystic fibrosis

Lipid, nitrogen, water and energy content of a single stool sample in healthy children and children with cystic fibrosis. Van den Neucker AM, Forget PP, van Kreel B. Department of Paediatrics, University Hospital Maastricht, P Debyelaan 25, 6229 HX Maastricht, The Netherlands. [email protected] To evaluate the usefulness of "single stool sample" analysis in the investigation of steatorrhoea instead of 72-h stool collection, we examined 57 stool samples of patients with cystic fibrosis (CF) while on pancreatic enzyme therapy and 29 stool samples of healthy children. We compared results of fat, nitrogen, water and energy content. Fat was determined by the method of Van de Kamer et al. and the Acid Steatocrit (AS) method, water by vacuum drying, nitrogen by the Dumas method and energy was obtained using a bomb calorimeter. Results (median) for CF patients and healthy controls were significantly different (P< or =0.0001) for fat respectively: 8.90 and 4.75/100 g wet weight (ww) stool as measured by the method of Van de Kamer et al. and 28.6% and 7.2% by the AS method. Energy results for energy were also significantly (P< or =0.0001) different: 742.96 and 549.32 kJ/100 g ww stool for CF patients and healthy controls respectively. Results of single stool sample water and nitrogen were similar in both groups. These results were comparable to those of a 3-day stool collection, as reported in the literature. CONCLUSION: Results from single stool samples yield clinically useful information concerning fat and energy. Single stool sample analysis is therefore useful for frequent monitoring of faecal fat and energ

Effects of therapy with lansoprazole on intestinal permeability and inflammation in young cystic fibrosis patients

Effects of therapy with lansoprazole on intestinal permeability and inflammation in young cystic fibrosis patients. Hendriks HJ, van Kreel B, Forget PP. Department of Paediatrics, University Hospital of Maastricht, Maastricht, The Netherlands. [email protected] BACKGROUND: Defective pancreatic bicarbonate secretion with low intestinal pH or intestinal inflammation of any origin increase intestinal permeability in cystic fibrosis (CF). METHODS: In this open study, the authors evaluated the effect of a proton-pump inhibitor on intestinal permeability and inflammation in 14 young, pancreatic-insufficient CF patients. Permeability was measured by a three-sugar permeability test before and after 1 year of lansoprazole use, and urinary nitric oxide (NO) oxidation products were assessed before and during that year as a marker of inflammation. RESULTS: After 1 year of lansoprazole use, median urinary recovery percentages changed from 2.5% to 1.7% (P = 0.064), from 24.9% to 24.5% (no significance), and from 10.5% to 11.1% (no significance) for lactulose, mannitol, and L-rhamnose, respectively. Despite the fact that the median urinary excretion ratios decreased from 0.108 to 0.083 (P = 0.03) and from 0.246 to 0.176 (P = 0.016) for lactulose and mannitol and for lactulose and rhamnose, respectively, they both remained increased. Median urinary NO products-to-creatinine ratios were 0.287 for CF patients before lansoprazole and 0.130 for healthy control participants (P = 0.002). Although there was a tendency toward a decrease in the NO products-to-creatinine ratio during treatment, this was not significant at the end point. CONCLUSIONS: Intestinal permeability is considerably increased in CF patients and is partly corrected after the use of a proton-pump inhibitor for 1 year, which may point to a harmful effect of the acid luminal contents on the tight junctional related paracellular permeability pathway. The start and end values for the NO products-to-creatinine ratio in CF patients were not significantly different, but were considerably increased when compared with control participants (P = 0.002)