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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 113 (1972), S. 193-204 
    ISSN: 1432-1076
    Keywords: Tyrosinosis ; Influence of Dietary Treatment ; Metabolism of Tyrosine, Phenylalanine, Methionine ; Hypoglycemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die biochemischen und klinischen Veränderungen eines Patienten mit Tyrosinose wurden über 2 Jahre verfolgt. Die Reduktion der Phenylalanin- und Tyrosinaufnahme führte zur Heilung der Rachitis sowie zur Normalisierung der Hypophosphatämie, der tubulären Phosphatreabsorption und der Methioninämie. Dieser Effekt war bei Auslaßversuchen reproduzierbar. Die Störungen im Methioninabbau besserten sich jedoch auch später unabhängig von der Tyrosinämie. Diese spontane Besserung, eher unabhängig von der Therapie und im Verlauf der Erkrankung oder mit zunehmendem Alter erfolgend, ließ sich gleichfalls an anderen Symptomen, wie der Thrombocytopenie, den Gerinnungsstörungen und dem verzögerten Phenylalaninabbau beobachten. Der fehlende oder nicht reproduzierbare Einfluß des normalisierten Tyrosinstoffwechsels auf diese Symptome spricht dafür, daß sie eher unabhängig neben der Tyrosinämie bestehen und nicht durch diese bedingt sind. Das Ausmaß der Tyrosinämie war in allen Krankheitsphasen abhängig von der Menge des aufgenommenen Phenylalanin und Tyrosin, die Belastungen mit Phenylalanin ergeben unabhängig vom Alter etwa gleiche Konzentrationskurven für Tyrosin. Die Störungen im Glucosestoffwechsel scheinen durch die Methioninämie verursacht, da Hypoglykämie und fehlender Anstieg des Blutzuckers nach Glukagoninjektion nur bei erhöhten Methioninserumkonzentrationen auftraten, bei isolierter Tyrosinerhöhung hingegen nicht gefunden wurden und beides durch eine Methioninbelastung provoziert werden konnte.
    Notes: Abstract A child with so-called “tyrosinosis” was treated with a reduced phenylalanine and tyrosine intake (100 mg/kg/day) for two periods of 2 and 9 months each. Healing of rickets, normalization of phosphate in the serum and increased tubular reabsorption of phosphate occurred during treatment achieving normal tyrosine levels, whilst these parameters, worsened when the tyrosine in the palsma rose. Methioninemia disappeared and reappeared together with tyrosinemia during and after the first period of treatment (methionine intake was unchanged). Later on these symptoms were no longer correlated, and high levels of methionine were only found during a period of vomiting, loss of weight, failure to grow and normal blood tyrosine levels. Thus the delayed methionine degradation seems be influenced by age, rate of protein synthesis and tyrosinemia. Thrombocytopenia, disturbed liver functions and other symptoms also improved with advancing age or during the natural course of the disease and did not seem to be directly related to dietary treatment. By contrast, the degree of tyrosinemia remained unchanged, depending on the amount of phenylalanine and tyrosine in the food. Hypoglycemia and methioninemia were correlated, the difference in blood sugar between periods with and without methioninemia being statistically significant. Furthermore, there was no rise in the glucose level after glucagon injection when the methionine level was elevated, whilst the results of the glucagon tests were approximately normal at low methionine levels. These findings indicate that hypoglycemia and rickets are secondary symptoms, whereas the other abnormalities seem be more independent of the disturbed tyrosine metabolism.
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  • 2
    ISSN: 1433-8580
    Keywords: Adrenal cortex ; Adrenocortical suppression ; Corticoid therapy ; Xylitol ; Sorbitol ; Nebennierenrinden ; Nebennierenrindensuppression ; Corticoidtherapie ; Xylit ; Sorbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 40 Kaninchen (weiße Neuseeländer) wurde untersucht, ob die dexamethasoninduzierte Nebennierenrindeninsuffizienz durch simultane Xylitzufuhr verhindert werden kann. Zu Beginn und am Ende der Versuchsperiode wurden Corticosteron und Cortisol im Serum mit einer Doppelisotopenmethode bestimmt. Darüber hinaus wurde die Stimulierbarkeit der Nebennierenrinden mitβ-1-24-Corticotrophin geprüft. Die alleinige Zufuhr von Sorbit oder Xylit führt weder zu morphologischen noch funktionellen Störungen der Nebennierenrinde. In der Gruppe, die Sorbit und Dexamethason erhielt, kam es zu einer ausgeprägten Nebennierenrindeninsuffizienz und partiellen Nebennierenrindenatrophie. In der Gruppe, die Xylit und Dexamethason erhielt, blieben funktionelle und morphologische Veränderungen der Nebennierenrinden aus. Somit ist anzunehmen, daß die dexamethasoninduzierte Nebennierenrindeninsuffizienz durch die gleichzeitige Applikation von Xylit bei Kaninchen verhindert werden kann.
    Notes: Summary In 40 rabbits (white New-Zealanders) studies were performed to evaluate whether the insufficiency of the adrenocortical system induced by dexamethasone may be prevented by simultaneous xylitol intake. Corticosterone and cortisol were determined in the serum by means of a double isotope method before and after the examination. Furthermore, the stimulation of the adrenal cortex byβ-1-24 corticotrophin was tested. The sole intake of sorbitol or xylitol results in neither morphological nor functional disturbances of the adrenal cortex. The group having been given sorbitol and dexamethasone revealed a marked insufficiency of the adrenocortical system and partial adrenocortical atrophy. The group receiving xylitol and dexamethasone did not show any functional or morphological changes of the adrenal cortex. So, the conclusion may be drawn that the adrenocortical insufficiency induced by dexamethasone can be prevented by the simultaneous administration of xylitol in rabbits.
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  • 3
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Methods for thin-layer chromatography of urinary amino acids on commercially available procoated plates of micro-crystalline cellulose are presented. The urine is desalted by passing it through columns containing Amberlite CG 120 I. The amino acids are eluted by a solution of 5 per cent ammonia. The eluate is taken to dryness and dissolved in such an amount of water that 1 µl corresponds to 1 µg of creatinine. 1 µl is spotted to plates (10×10 cm) by micro pipets. Every urine is developed two-dimensionally by two solvent pairs. First pair: Ethanol-H2O (83:17), first direction, three times developed up to 8 cm, tert-Butanolmethylethylketone-NH3-diethylamine-H2O (35:35:10:0,4:20), second direction, once developed up to 8 cm. Second pair: n-Butanol-acetone-glacial acetic acid-H2O (35:35:10:20), first direction, phenol-formic acid (15 per cent) (250 g+83 ml), second direction, once developed up to 8 cm. Using these solvent pairs it is possible to separate most of the important urinary amino acids and diagnose or suspect most of the known metabolic disorders with a disturbed urinary excretion of amino acids. Phosphoethanolamine, S-sulphocysteine and taurine are lost by desalting the urine. Special problems of detecting and locating some amino acids are discussed.
    Notes: Zusammenfassung Es werden Methoden zur Dünnschichtchromatographie der Harnaminosäuren auf mikrokristalliner Cellulose angegeben. Vor der dünnschichtchromatographischen Trennung wird der Urin (Amberlite CG 120 I, H+-Form; Elution mit 5% igem NH3) entsalzt. Nach Einengen des Eluats zur Trockne und Lösung des Rückstandes in einer auf den Kreatiningehalt des Urins bezogenen Menge Wasser wird der Urin auf Cellulose-Fertigplatten der Fa. Merck AG. aufgetragen. Die Plattengröße beträgt 10×10 cm. Durch Verwendung von zwei Fließmittelpaaren ist es möglich, bei den meisten der bekannten Stoffwechselkrankheiten mit vermehrter Aminosäure-Ausscheidung eine Diagnose oder eine Verdachtsdiagnose zu stellen. Ausnahmen sind lediglich die Hypophosphatasie, der Sulfitoxydase-Mangel und die Taurinurie, da die bei diesen Störungen vermehrt ausgeschiedenen Aminosäuren Phosphoäthanolamin, S-Sulfo-l-cystein und Taurin bei der Entsalzung verloren gehen. Auf spezielle Probleme des Nachweises einzelner Aminosäuren wird eingegangen.
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  • 4
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Notes: Summary The cytotoxicity of 5-hydroxymethyl furfural (HMF) was tested in vitro using cultures of chick embryo fibroblasts. Cellular dammage was observed at a concentration of 0,5 mg HMF/ml of medium, growth arrest at 1 mg/ml.
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  • 5
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-Isopropyl-4-thia-2,6-diazabicyclo[3.2.0]heptan-7-on (8), a potential intermediate for the synthesis of new β-lactam antibiotics [5], was prepared from the urethanes 7a and 9 by reduction with zinc/acetic acid. The cyclic Schiff base 10, which constitutes an intermediate in this reaction, was prepared by reduction of 9 with CrCl2 and was further reduced to 8 with zinc/acetic acid.
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  • 6
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thiazolidine β-lactam 3 adds acrolein in a Michael type reaction. The resulting 'carbinolamide 4 is converted to 8-β-phenylacetamido-homoceph-4-em-5-carboxylic acid (1) by previously described methods.
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  • 7
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ‘7-aminocephalocillanic acid’ 1, an intermediate for the preparation of new β-lactam antibiotics was prepared by transforming the β-lactam carbinol 2a to the phosphorane 9a through several steps. Oxydation of 9a with DMSO/Ac2O led directly to the cyclized ester 11a, which has been converted into 1 by known methods.
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  • 8
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxydation of 2 with iodine followed by acylation leads to β-lactamdisulfides of type 3. Compounds 3 can be transformed into alcohols 4 by reductive alkylation with ethylenoxide and zinc/acetic acid. Compounds 4 are used as starting materials for the synthesis of N-acylderivatives 12 of 7-amino-ceph-3-em-4-carboxylic acid (D).
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