Pteridines are produced during interleukin 2-induced T-cell proliferation and modulate transmission of this signal

Pteridine levels of interleukin 2 (IL-2) receptor+ T-cell populations have been determined by HPLC after iodine oxidation; neopterin was monitored in the culture supernatants by radio-immunoassay. Upon addition of IL-2, cellular levels of biopterin and 6-hydroxymethylpterin rise transiently from 0.02 to 0.9 pmol/10(6) cells, cellular levels of neopterin from 1.5 to 4.1 pmol/10(6) cells. They peak at 8 and 13 h, respectively, after exposure to IL-2. Neopterin is not accumulated in the culture supernatant. DNA synthesis in T cells begins 10-12 h after adding the lymphokine and the portion of cells that undergo S-phase transition gradually increases during the subsequent 10 h. Entry into DNA synthesis phase is markedly accelerated if IL-2 is supplied together with tetrahydrobiopterin (0.8-1.6 X 10(-6) M) and the kinetics of entry into the S-phase transition during the period of 6-20 h become linear. This indicates that tetrahydrobiopterin modulation of IL-2 activity (Ziegler, I. et al. Naturwiss 72 (1985) 330) is an early event occurring during IL-2 signal transmission.     

The effect of SO 3 -- on the activity of ribulose-1,5-diphosphate carboxylase in isolated spinach chloroplasts

Summary SO ₃ ^-- inhibits the activity of ribulose-1,5-diphosphate carboxylase in isolated spinach chloroplasts. It shows a non-competitive inhibition pattern with respect to ribulose-1,5-diphosphate and Mg⁺⁺ but a competitive one with respect to HCO ₃ ^- . The K _i -values are 14 mM SO ₃ ^-- and 9.5 mM SO ₃ ^- respectively for the non-competitive inhibition but only 3.0 mM SO ₃ ^-- in the case of competitive inhibition with HCO ₃ ^-- as a substrate. Thus it is concluded that the competitive inhibition type will predominate at low SO ₃ ^-- and low internal CO₂ concentrations.The abbreviations used RuDph ribulose-1,5-diphosphate - DTT dithiothreitol - EDTA ethylenediaminetetraacetate     

The Escherichia coli SRP Receptor Forms a Homodimer at the Membrane

1. Download high-res image (230KB)
2. Download full-size image

     

Zur Wirkungsweise des white-Allels bei Drosophila melanogaster

Zusammenfassung In den pigmentfreien Augen derwhite-Mutante vonDrosophila melanogaster wurden die gleichen Trägergranula histologisch nachgewiesen, in die die Augenpigmente (Pterine und Ommochrome) bei der Wildform eingelagert sind. In Zusammensetzung (Protein, Ribonucleinsäure, Lipoidphosphat) und biochemischer Funktion (hohe Aktivität der Enzyme der biologischen Oxydation) ähneln sie Mitochondrien. Die Granula der Mutante unterscheiden sich von denen der Wildform darin, daß in ihnen die Succinodehydrase locker, die Protyrosinase dagegen fester gebunden ist, wie Enzymteste in Medien verschiedenen osmotischen Druckes ergaben. diese Unterschiede in den Enzymaktivitäten können eine weitere phänotypische Auswirkung deswhite-Allels sein; auf einen ursächlichen Zusammenhang dieser Ergebnisse mit der fehlenden Fähigkeit, die Endstufen der Augenpigmente zu synthetisieren, wird hingewiesen.

---

---

Mit 5 Textabbildungen     

Hyaluronidase Modulates Inflammatory Response and Accelerates the Cutaneous Wound Healing

Hyaluronidases are enzymes that degrade hyaluronan an important constituent of the extracellular matrix. They have been used as a spreading agent, improving the absorption of drugs and facilitating the subcutaneous infusion of fluids. Here, we investigated the influence of bovine testes hyaluronidase (HYAL) during cutaneous wound healing in in vitro and in vivo assays. We demonstrated in the wound scratch assay that HYAL increased the migration and proliferation of fibroblasts in vitro at low concentration, e.g. 0.1 U HYAL enhanced the cell number by 20%. HYAL presented faster and higher reepithelialization in in vivo full-thickness excisional wounds generated on adult Wistar rats back skin already in the early phase at 2^nd day post operatory compared to vehicle-control group. Wound closured area observed in the 16 U and 32 U HYAL treated rats reached 38% and 46% compared to 19% in the controls, respectively. Histological and biochemical analyses supported the clinical observations and showed that HYAL treated wounds exhibited increased granulation tissue, diminished edema formation and regulated the inflammatory response by modulating the release of pro and anti-inflammatory cytokines, growth factor and eicosanoids mediators. Moreover, HYAL increased gene expression of peroxisome proliferator-activated receptors (PPAR) γ and PPAR β/δ, the collagen content in the early stages of healing processes as well as angiogenesis. Altogether these data revealed that HYAL accelerates wound healing processes and might be beneficial for treating wound disorders.     

Different forms of 130 kD connective tissue protein are specific for boundaries in the nervous system and basement membrane of muscle cells in leech

The nervous system and muscle tissue of the leech express two different organ-specific forms of connective tissue protein. The nervous system-specific form appears in regional boundaries separating cell bodies, axonal tracts and areas of the neuropile during late embryogenesis. In contrast, the muscle-specific form appears earlier during development in the basement membrane of muscle cells. In extraction experiments both forms behave like extracellular matrix proteins and because of their molecular weight, are considered members of a group of cell type-specific 130 kD proteins (leech gp130s). How ever, the two forms differ in their posttranslational modification. As determined by Con A and lentil lectin affinity chromatography, only the nervous system-specific, but not the muscle-specific form, has fucosylated and high mannose N-linked carbohydrates. These differences in the developmental onset and glycosylation suggest that nervous system-specific and muscle-specific connective tissue proteins are regulated differently and participate in different molecular interactions. © 1993 John Wiley & Sons, Inc.     

Distribution and diel migration of macroinvertebrates within dense submerged vegetation

1. We studied vertical and horizontal distribution of macroinvertebrates within a dense stand of Chara spp. in Lake Krankesjön, southern Sweden. Invertebrates were sampled at three depths within the vegetation and at three distances from the vegetation edge during day and night in July and August. Corresponding samples of oxygen content of the water were taken.
2. The densities (number of invertebrates per unit plant biomass) of most invertebrate taxa were generally lower in the upper layers of the vegetation than in the layers close to the sediment. The densities of several taxa ( Asellus aquaticus , Cloëon sp. and Polycentropodidae), as well as total density of invertebrates, were higher at the edge than in the innermost parts of the macrophyte stand, whereas snail densities generally were highest at the innermost sites.
3. Densities of A. aquaticus , Chironomidae larvae and Helobdella stagnalis generally increased at night. These taxa appear to undertake a diel vertical migration within the vegetation, towards, or even down to the sediment in daytime and up into the vegetation, in some cases to the vegetation surface, at night. Factors underlying the diel vertical migration are discussed, as are their ecological consequences.     

Ist eine Unterscheidung der Genotypen der Blutgruppe A mit Hilfe eines thermodynamischen Effektes möglich?

Zusammenfassung Der Kern eines von Filitti-Wurmser u. Mitarb. seit 1946 veröffentlichten Verfahrens, das mit Hilfe eines thermodynamischen Effekts eine Differenzierung der Genotypen der Blutgruppe A erlauben soll, erwies sich bei Nachprüfung der wesentlichen Einzelschritte der Methode als ungeeignet: weder lassen sich A₁A₁-Seren von A₁O-Seren unterscheiden, noch sind die Resultate überhaupt reproduzierbar.

---

Summary The essentials of a method for the distinction of blood group A genotypes by their thermodynamic properties, published by Filitti-Wurmser and co-workers, were checked. By investigation of its chief details, this method was proven to be disappointing. Neither can A₁A₁ sera be distinguished from A₁O sera nor are the results reproducible at all.

---

Résumé La substance d'une méthode — publiée depuis 1946 de Filitti-Wurmser et coopérateurs — laquelle doit permettre une différenciation des génotypes du groupe sanguin A au moyen d'un effet thermodynamique, se montrait impropre quand les essentiels dégrés détaillés de la méthode furent verifiés. On ne peut pas distinguer les sérums A₁A₁ des sérums A₁O et les résultats sont pas du tout reproductibles.

---

---

Herrn Professor Dr. B. Mueller (Heidelberg) zur Vollendung des 70. Lebensjahres gewidmet.

---

Ein Auszug der Arbeit wurde anläßlich der 46. Tagung der Deutschen Gesellschaft für gerichtliche Medizin, Kiel 1967, vorgetragen.