On the early history of Bessel functions

Communicated by Curtis Wilson     

Molecular insights into the regulation of iron metabolism during the prenatal and early postnatal periods

Molecular iron metabolism and its regulation are least well understood in the fetal and early postnatal periods of mammalian ontogenic development. The scope of this review is to summarize recent progress in uncovering the molecular mechanisms of fetal iron homeostasis, introduce the molecules involved in iron transfer across the placenta, and briefly explain the role of iron transporters in the absorption of this microelement during early postnatal life. These issues are discussed and parallels are drawn with the relatively well-established system for elemental and heme iron regulation in adult mammals. We conclude that detailed investigations into the regulatory mechanisms of iron metabolism at early stages of development are required in order to optimize strategies to prevent neonatal iron deficiency. We propose that newborn piglets represent a suitable animal model for studies on iron deficiency anemia in neonates.     

On the regulation of lactate dehydrogenase isoenzyme concentrations in mammalian cells

Zusammenfassung Fritz et al.³ haben in Nature New Biol. 230, 119 ein Modell publiziert, mit dem sie die Regulation der intrazellulären LDH-Isoenzym-Konzentration erklären. Die vorliegende Arbeit zeigt, dass die Resultate vonFritz et al. einfacher durch Heterogenität der Zellen des untersuchten Gewebes erklärt werden kann als durch ihr Modell mit non-random association der LDH-Untereinheiten und verschiedenen turnover-Raten der Isoenzyme in derselben Zelle.

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I thank Drs.Ursprung, D. Turner, D. Seybold andH. Eppenberger for helpful discussions. This work was supported by the Swiss National Science Foundation, Project No. 3.247.69.     

Inhibition of the infective activity of bacteriophage f2 by spermine

Résumé La spermine a un effet inhibiteur sur la reproduction du phage f₂. Cette inhibition dépend de la concentration de la spermine. Ne diminuant pas le taux du phage libre et n'ayant pas d'effet sur l'adsorption, la spermine réduit l'activité de l'ARN infectieuse et la production du phage dans les sphéroplastes infectés.     

Structure and morphogenesis of bacteriophage T4

Bacteriophage T4 is one of the most complex viruses. More than 40 different proteins form the mature virion, which consists of a protein shell encapsidating a 172-kbp double-stranded genomic DNA, a tail, and fibers, attached to the distal end of the tail. The fibers and the tail carry the host cell recognition sensors and are required for attachment of the phage to the cell surface. The tail also serves as a channel for delivery of the phage DNA from the head into the host cell cytoplasm. The tail is attached to the unique portal vertex of the head through which the phage DNA is packaged during head assembly. Similar to other phages, and also herpes viruses, the unique vertex is occupied by a dodecameric portal protein, which is involved in DNA packaging.Received 18 February 2003; received after revision 16 April 2003; accepted 9 May 2003     

Properties of RNA containing bacteriophage f4

Résumé Les propriétés du coliphage f4 ont été étudiées. L'hydrolysat acide révèle une composition en acides aminées semblable à celle de f2. L'histidine est absente, et, en comparaison avec le phage f2, il y a un résidu additionnel de méthionine par molécule. L'analyse de la digestion trypsique a montré neuf peptides, comme celle de f2. Le RNA a des proportions équimolaires de bases. Par analyse sur colonne MAK ce RNA présente seulement un pic correspondant à la position de l'hybride RNA:DNA bactérien.