Effect of canine surfactant protein (SP-A) on the respiratory burst of phagocytic cells

Cells obtained from bronchoalveolar lavage, or neutrophils of peripheral blood of dog, were incubated with the canine surfactant-associated protein A (SP-A). A significant decrease of the production of Superoxide anion was observed after subsequent stimulation with phorbol-12-myristate-13-acetate (PMA) as measured by the lucigenin-dependent chemiluminesence (CL). Several other proteins used for control experiments did not decrease lucigenin-dependent CL, indicating a specific effect of SP-A on phagocytes. Treatment of SP-A with collagenase prior to incubation with neutrophils destroyed the depleting effect on oxygen radical production of PMA-stimulated cells. We propose that SP-A acts as a regulatory factor of the respitatory burst of alveolar macrophages and neutrophils in the lungs. The inhibitory effect of SP-A is down-regulated by collagenase released from stimulated alveolar macrophages.     

Hohltauben (Columba oenas) schlafen auf dem Erdboden

Zusammenfassung Im Herbst 1984 schliefen mindestens 50 Hohltauben (Columba oenas), wahrscheinlich aber wesentlich mehr, an drei verschiedenen Stellen auf grobscholligen Sturzäckern der offenen Ackerlandschaft des Marchfeldes östlich von Wien. Bäume verwendeten sie nur als Sammelplatz. Im gleichen Zeitraum war auch ein traditioneller Schlafplatz zusammen mit Türkentauben (Streptopelia decaoto) in einem Wiener Randbezirk (16 km entfernt) benutzt; er lag in einem Gehölz.

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Stock Doves (Columba oenas) roosting also in open fields

Summary In autumn 1984, at least 50 — probably many more — Stock Doves roosted in open fields, roughly ploughed, east of Vienna. The nearest trees, 200 metres distant, were used only as perches until darkness approached. Some 16 km distant, another roosting place in trees was shared with Collared Doves (Streptopelia decaocto).

     

Cloning and expression of bacteriophage SP02 DNAZ polymerase gene L in Bacillus subtilis, using the Staphylococcus aureus plasmid pC194

HindIII restriction endonuclease fragments of DNA from temperate Bacillus subtilis bacteriophage SP02 were cloned in B. subtilis by using the plasmid pC194. Three hybrid plasmids which permit growth of the mutant SP02 susL244 in suppressor-negative bacteria were isolated. SP02 gene L is thought to code for a DNA polymerase essential for autonomous replication of SP02 DNA. Extracts of bacteria carrying one of these hybrid plasmids, pC194-96, had 10- to 30-fold increased DNA polymerase activity. The plasmid-induced DNA polymerase activity differed from that of the known B. subtilis DNA polymerases in several respects. The results of the experiments support the idea that phage SP02 codes for a new DNA polymerase.     

The involvement of phytochrome in controlling chlorophyll and 5-aminolevulinate formation in a gymnosperm seedling (Pinus sylvestris)

Chlorophyll a (Chl a) accumulation in the cotyledons of Scots pine seedlings (Pinus sylvestris L.) is much higher in the light than in darkness where it ceases 6 days after germination. When these darkgrown seedlings are treated with continuous white light (3,500 lx) a 3 h lag phase appears before Chl a accumulation is resumed. The lag phase can be eliminated by pretreating the seedlings with 7 h of weak red light (0.14 Wm^-2) or with 14 red light pulses separated by relatively short dark periods (<100 min). The effect of 15s red light pulses can be fully reversed by 1 min far-red light pulses. This reversibility is lost within 2 min. In addition, the amount of Chl a formed within 27 h of continuous red light is considerably reduced by the simultaneous application of far-red (RG 9) light. It is concluded that phytochrome (P_fr) is required not only for the elimination of the lagphase but also to maintain a high rate of Chl a accumulation in continuous light. Since accumulation of 5-aminolevulinate (ALA) responds in the same manner as Chl a accumulation to a red light pretreatment it is further concluded that ALA formation is the point where phytochrome regulates Chl biosynthesis in continuous light. No correlation has been found between ALA and Chl a formation in darkness. This indicates that in a darkgrown pine seedling ALA formation is not rate limiting for Chl a accumulation.Abbreviations Chl chlorophyll(ide) - PChl protochlorophyll(ide) - ALA 5-aminolevulinate - P_r the red absorbing form of phytochrome - P_fr the far-red absorbing form of phytochrome - P_tot total phytochrome ([P_r]+[P_fr])     

Membranes of the protoplast L-form of Proteus mirabilis

Isolated membranes of the cell wall-less stable protoplast L-form of Proteus mirabilis were characterized by density gradient centrifugation and by assay for their major chemical constituents, proteins, phospholipids and lipopolysaccharide, and for some specific marker enzymes of the cytoplasmic membrane. In most of the analyzed properties the L-form protoplast membrane resembled the bacterial cytoplasmic membrane, with some notable modifications. considerable amounts of lipopolysaccharide, normally an exclusive constituent of the outer membrane, were found. Furthermore, the L-form membranes contained the functions of the reduced nicotinamide adenine dinucleotide oxidase system, of d-lactate dehydrogenase (EC 1.1.1.28) and of succinate dehydrogenase (EC 1.3.99.1) at specific activities comparable to, or in some cases considerably higher than, those present in cytoplasmic membranes of the bacterial form. Of two peptidoglycan DD-carboxypetidase/transpeptidases (EC 3.4.17.8 and EC 2.3.2.10), which are normally present in the cytoplasmic membrane of the bacterial form of P. mirabilis, the membrane of the protoplast L-form contained only one. Electron microscopy of thin sectioned L-form protoplasts showed extensive heterogeneity of membraneous structures. In addition to the single membraneous integument, internal membrane-bounded vesicles and multiple stacks of membranes were present, as the result of unbalanced growth and membrane synthesis in the L-form state.     

The α-keto acids of branched-chain amino acids: Simplified derivatization for physiological samples and complete separation as quinoxalinols by packed column gas chromatography

By use of a relatively new mixed stationary phase, complete separation of the branched-chain α-keto acids as O-trimethylsilyl-quinoxalinol derivatives is achieved within 10 min by packed column gas chromatography. Precise quantification of less than 5 nmol of α-keto acids in biological samples is possible. In small aqueous samples the α-keto acids are directly derivatized without prior purification. Plasma need only be deproteinized by perchlorate and neutralized before derivatization. Average relative precision for determination of the three main branched-chain α-keto acids is ± 5.8%.