Fat and glycogen utilization in the larynx muscles of fire-bellied toads (Bombina bombina L.) during calling activity

Summary Both fat and glycogen are present in abundance in the larynx muscles of anurans. To clarify their role, the Musculus dilatator laryngis of the male fire-bellied toad, Bombina bombina was studied.In untreated males, the mean fat content of this larynx muscle was 14%; the muscle contained glycogen amounting to 57% of that measured in the liver tissue of the same animal. After thirteen days of continual calling activity induced by administration of a gonadotropin, the fat content fell to 6%, the glycogen to 34%. The fat content was essentially unchanged (13%) by four hours of electrical stimulation of the muscle; the glycogen content, however, had fallen to 42% after this treatment. Neither component was altered in amount by castration, the fat content being about 13% and that of glycogen, 52%. Nor did treatment with gonadotropic hormone reduce either the fat content (13%) or the amount of glycogen (59%).From these results it was concluded that fats represent a direct source of energy for the larynx muscles, which is used up gradually over long periods of calling. The glycogen in these muscles, on the other hand, is a short-term store sufficient to supply energy for only a few hours of calling activity.Supported by the Deutsche Forschungsgemeinschaft.     

Chemotactic response of a gliding mycoplasma

Mycoplasma sp. nov. strain 163K, the gliding microorganism isolated from the gills of a tench (Tinca tinca L.), is capable of chemotaxis, being attracted to sugars, amino acids, and mucus. The chemotactic behavior of the organisms was microscopically investigated and documented by long-time exposure photomicrographs providing motility tracks. In diffusion-generated concentration gradients of chemoattractive substances, the random motion of the mycoplasmas was strongly biased in the direction of increasing attractant concentrations.     

Disodium Cromoglycate in the Prevention of Induced Asthma

In 13 patients with allergic asthma disodium cromoglycate protected fully only two from an allergen-induced asthmatic attack.Inhalation of disodium cromoglycate did not improve lung function in five patients with long-standing chronic asthma.Previous clinical trials do not show convincing evidence that this drug improves bronchial asthma in a high percentage of cases, but it seems to help a small minority of patients.     

Zur Gleichgewichtsorienuerung schrägstehender Fische

Ohne ZusammenfassungDie Arbeit wurde mit Unterstützung der Deutschen Forschungsgemeinschaft durchgeführt.     

Some aspects of buoyancy adaptations of chaetognaths

Chaetognaths mainly keep to a preferred depth range by movement and resistance achieved by body shape. Some species, for exampleSagitta lyra andS. hexaptera, developed conspicuous, voluminous, gelatinous inner parts in the lateral fins. These are considered an aid toward buoyancy, as they compensate the increasing density caused by maturing gonads. Probably, the small size of the sexual organs ofS. enflata can also be regarded as a buoyancy adaptation. Member of the Taxonomy Group at the Biologische Anstalt Helgoland     

The dark respiration of Anacystis nidulans: Production of HCN from histidine and oxidation of basic amino acids

The basic amino acids, L-arginine, L-lysine, L-ornithine, and to a lesser extent L-histidine, strongly stimulate the O₂ uptake of cell suspensions of the blue-green alga or cyanobacterium Anacystis nidulans. In the case of L-histidine, the extra O₂ consumption is associated with the formation in vivo of small amounts of HCN, particularly in an atmosphere of O₂. The enzyme responsible for both the stimulated O₂ uptake with the basic amino acids and the formation of HCN from histidine has been isolated and identified as an L-amino acid oxidase specific for the basic amino acids. The purification (15 000-fold) of this enzyme is described. The isolated enzyme is inhibited by o-phenanthroline, which has a similar inhibitory effect on the O₂ uptake of cell suspensions with (and without) added amino acids.The basic amino acid oxidase, which is not inhibited by HCN, can be regarded as an ‘alternate’ oxidase in A. nidulans. An oxidase sensitive to HCN is apparently also operative. At high concentrations of lysine or arginine added HCN can almost double the initial rate of O₂ consumption of cell suspensions. This can be attributed to the inhibition of catalase by HCN. At low concentrations of the amino acids, and with more prolonged incubation time, HCN becomes inhibitory. One interpretation could be that the HCN-sensitive terminal oxidase is also involved in the extra O₂ uptake elicited by the basic amino acids, but other interpretations are possible. The extra O₂ uptake elicited by histidine is almost completely inhibited by HCN, which is consistent with the finding that histidine is a relatively poor substrate for the basic amino acid oxidase.     

Antibody Binding Heterogeneity of Protein A Resins

Protein A affinity chromatography is a core unit operation in antibody manufacturing. Nevertheless, there is not enough understanding of in‐column antibody adsorption in the Protein A capture step. This work aims to investigate in situ the establishment of an antibody (trastuzumab) layer during Protein A chromatography both in terms of energetic contributions and uptake kinetics. Flow microcalorimetry is employed as a technique with an in situ operating detector, which provides an understanding of the thermodynamics of the adsorption process. In addition, the antibody uptake rate is also investigated in order to establish a correlation between its diffusion on the stationary phase and the associated thermodynamics. Two resins with different particle size, intraparticle porosity, and a Protein A ligand structure are studied: the synthetically engineered B‐domain tetrameric MabSelect SuRe and the synthetically engineered C‐domain hexameric TOYOPEARL AF‐rProtein A HC. The uptake rate follows a pore diffusion model at low equilibrium time, showing a slower diffusivity after a certain time because of the heterogeneous binding nature of these two resins. In addition, the microcalorimetric studies show that adsorption enthalpy is highly favourable at low isotherm concentrations and evolves toward an equilibrium with increasing surface concentration. These data suggest that the relationship between adsorption enthalpy and the establishment of the antibody layer in the Protein A chain is consistent with heterogeneous adsorption.