Complement components and terminal complement complex in oesophageal smooth muscle of patients with achalasia.

This study investigates whether patients with achalasia exhibit autoimmune reactions with subsequent complement activation within oesophageal smooth muscle, vessels and neurones. Oesophageal muscular biopsies from 8 patients undergoing surgery for achalasia and from 6 patients operated for oesophageal cancer were investigated by immunofluorescence for the presence of the complement components C1q, C4, C3c, C3d, C9 and the C9 neoantigen of the terminal C5b-C9 complement complex. Tissues were also investigated for the expression of immunoglobulins (G,A,M) and of the antigens of rubella and varicella zoster viruses. In addition, sera of both patient groups were tested for the presence of autoantibodies against Auerbach's plexus. The terminal complement complex C5b-C9 was found within muscle cells from all patients with achalasia but in only one specimen from a patient with cancer. Two patients with achalasia also exhibited the terminal complement complex as well as IgM within ganglion cells. Muscle cells stained positive for the complement component C9 in all five patients with achalasia in whom this test was performed but in none of the control tissues. In addition, sera from four patients with achalasia contained antibodies against Auerbach's plexus. Studies for the complement components C1q, C4, C3c and for antigens of rubella and varicella zoster viruses revealed negative results in all patients and controls. The results of this study suggest that a complement activation is involved in the autoimmune pathogenesis of achalasia. However, the triggering mechanism of this phenomenon remains to be determined.     

Micro-analysis of pure deoxyribonucleic acid-dependent ribonucleic acid polymerase from Escherichia coli. Action of heparin and rifampicin on structure and function

By using micro disc electrophoresis and micro-diffusion techniques, the interaction of pure DNA-dependent RNA polymerase (EC 2.7.7.6) from Escherichia coli with the template, the substrates and the inhibitors heparin and rifampicin was investigated. The following findings were obtained: (1) heparin converts the 24S and 18S particles of the polymerase into the 13S form; (2) heparin inhibits RNA synthesis by dissociating the enzyme-template complex; (3) rifampicin does not affect the attachment of heparin to the enzyme; (4) the substrates ATP and UTP are bound by enzyme loaded with rifampicin; (5) rifampicin is bound by an enzyme-template complex to the same extent as by an RNA-synthesizing enzyme-template complex. From this it is concluded that the mechanism of the inhibition of RNA synthesis by rifampicin is radically different from that by heparin. As a working hypothesis to explain the inhibitory mechanism of rifampicin, it is assumed that it becomes very firmly attached to a position close to the synthesizing site and only blocks this when no synthesis is in progress.     

Elektronenmikroskopische Untersuchung eines Mechanorezeptors von Evertebraten (Priapuliden,Oligochaeten)

Zusammenfassung Rezeptoren von Priapulus caudatus und Rhynchelmis limosella werden elektronenmikroskopisch untersucht. Ihre Strukturen stimmen in folgenden Merkmalen überein: Apikal steht eine Zilie, die von regelmäßig angeordneten Mikrovilli umgeben wird. Das Cytoplasma der Mikrovilli ist zentral verdichtet und im übrigen Bereich von Filamenten ausgefüllt, die im Perikaryon wurzeln. Im distalen Teil der Zelle liegt ein reich entwickeltes glattes E. R., darunter folgen Tubuli. Die Zellen werden reich innerviert.Aufgrund der strukturellen Übereinstimmung mit Mechanorezeptoren anderer Tiergruppen wird den Rezeptoren der untersuchten Formen ebenfalls eine mechanorezeptive Funktion zugeschrieben.

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Electron microscopic observations on a mechanoreceptor of invertebrates (Priapulida, Oligochaeta)

Summary Epidermal receptor cells of Priapulus caudatus and Rhynchelmis limosella have been investigated with the electron microscope. The following structural peculiarities characterize these cells: an apical cilium is surrounded by regularly arranged microvilli, which contain filaments extending into the cytoplasm of the cell body. The central part of the microvilli is electron dense. The apical part of the cell contains abundant tubules of smooth E. R., below which microtubules are located. The cells are richly innervated.These elements are interpreted to represent mechanoreceptors because they have the above mentioned structures in common with mechanoreceptors of other invertebrate groups.

Für die Überlassung eines Arbeitsplatzes im Anatomischen Institut und im Institut für Pharmakognosie Kiel danken wir Herrn Prof. Dr. W. Bargmann und Herrn Prof. Dr. O. Moritz.     

Methanogenesis in a saltern in the Bretagne (France)

Abstract Salterns in the Bretagne (France), exhibiting different stages of salinity of 5% to 33% evolved up to 0.7 mmol methane per m² per day. Methane concentrations of up to 0.4 mM were found. High methane evolution rates and increased methane concetration were restricted to basins of up to 7% and more than 15% salinity, and to the upper 10 cm of the sediments, where high sulfate concentrations (50 to 100 mM) occurred as well. Basins of 10–15% salinity exhibited only low methane evolution rates (less than 0.05 mmol methane per m² per day) and low methane concentrations (less than 0.02 mM). Gas bubbles arising during times of increased photosynthetic activity from the microbial mats covering the sediments of the saltern basins contained up to 2% methane. Addition of methylated amines and methanol, but not of H₂/CO₂, formate or acetate, to sediments slurries from basins of up to 12% salinity resulted in a rapid enrichment of methanogenic populations. Enriched methanogenic bacteria did not grow at salinities exceeding 15% or temperatures exceeding 45°C, and showed characteristics similar to those documented for Methanococcus halophilus and strain SF1 (DSM 3243). No enrichments were obtained from basins of more than 20% salinity in spite of methane being produced and evolved from those basins.     

Effects of exposure to short-term heat stress on fitness components in Drosophila melanogaster

Effects of thermal stress on survival and reproductive success in ten recently collected isofemale lines of Drosophila melanogaster were compared for flies treated as follows: always held at 25° C, placed in an incubator set at 37° C for 120 min, or exposed to 40° C in an incubator for 90 min, with or without previous exposure to 37° C. Short-term exposure to the higher temperature greatly reduced adult survival, the mating frequency of males and females, and female fecundity, which was measured as offspring produced over ten days. Male fertility, measured as the progeny produced by a female mated once, differed little among treatments. Previous exposure to a high, but non-lethal, temperature before exposure to the higher one, improved survival of males and females, and improved offspring production of females. Genetic variation was present among lines for offspring production, but genetic variation for survival was not significant, and genotype by environment interactions for fitness components of females were small. These results indicated low genetic variation in thermal resistance in the studied population, such that a threshold for temperature stress probably exists, above which local extinction is more likely than the evolution of resistance.