Mass spectrometry of oligonucleotides

Expanding research in the field of modified oligonucleotides demands suitable analytical tools for size and purity verification of known compounds and accurate structure elucidation of unknowns. There is a need for characterization of the types and sites of modifications in oligonucleotides and to identify and sequence selected candidates originating from synthesis. The potential of electrospray tandem mass spectrometry (ESI-MS/MS) for structural characterization and sequencing of oligonucleotides is demonstrated. The fundamental behavior of DNA, RNA, and selected modified oligonucleotides in gas-phase is shown. Since gas-phase dissociation does not demand specific structural prerequisites, the method bears a great potential for rapid and most accurate characterization of modified oligonucleotides, e.g. from combinatorial libraries.     

A simple water bath test for estimating the thermoregulation efficiency of man

A water bath test is described in which the left hand is cooled in water at 10 to 15C for 2 min, and the temperature then measured in the centre of the palm with a thermocouple every 15 sec. Temperature is plotted against time forming a rewarming curve. The curves for subjects suffering from diseases which may involve impaired function of the thermoregulation centre show certain features which do not occur in normal subjects. Examples are presented and the question is discussed whether the rewarming curve could serve as a test for the function of the thermoregulation centre.

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Zusammenfassung Ein Wasserbad-Test wird beschireben: Die linke Hand wird 2 Min.bei 10 bis 15C in Wasser gekühlt und danach alle 15 Sek. die Temperatur in der HandflÄche mit einer Thermosonde gemessen. Die Temperatur wird gegen die Zeit in einer ErwÄrmungskurve aufgetragen. Die Kurven von Patienten mit Krankheiten, die wahrscheinlich eine gestörte Funktion des WÄrmezentrums aufweisen, zeigen bestimmte Eigenarten,die bei gesunden Personen nicht gefunden werden. Beispiele werden gegeben und die Frage wird diskutiert, ob die ErwÄrmungskurve als ein Test für die Funktion des WÄrmezentrums dienen kann.

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Resume Un test au bain-marie est décrit comme suit:La main gauche est rafraÎchie pendant deux minutes à environ 10 à 15C. Ensuite la température est mesurée toutes les 15 sec. au milieu de la paume (de la main) à l'aide d'une thermosonde. La température et le temps sont marqués sur une courbe d'échauffement. Les courbes des patients souffrant vraisemblablement d'une fonction troublée du centre de régulation thermique montrent certaines particularités qu'on ne trouve pas chez les personnes saines. Des résultats sont présentés et la question de savoir si la courbe d'échauffement peut servir de test pour la fonction du centre de régulation thermique est discutée.

     

Exclusion of COL1A1, COL1A2, and COL3A1 genes as candidate genes for Ehlers-Danlos syndrome type I in one large family

Summary Ehlers-Danlos syndrome (EDS) type I is a generalized connective tissue disorder, the major manifestations of which are soft, velvety hyperextensible skin and moderately severe joint hypermobility. The gene defect or defects causing EDS type I have not yet been defined, but previous observations suggested that the syndrome may be caused by mutations in the genes for type-I collagen (COL1A1 and COL1A2) or type-III collagen (COL3A1). Here, we performed linkage studies for these three genes in large Azerbaijanian family with EDS type I. Three polymorphisms in the COL3A1 gene, two in the COL1A1 gene, and one in the COL1A2 gene were tested using the polymerase chain reaction. The data obtained excluded linkage of any of the three genes to EDS type I in the family.On leave of absence from Institute of Human Genetics, National Research Center of Medical Genetics, Moskvorechie St., 1. Moscow 115478, USSR