The effects of reticular stimulation on digastric reflex activity during sleep and wakefulness

Résumé La stimulation électrique de la formation réticulaire mésencéphalique fut appliquée 0–20 msec avant l'induction du réflexe digastrique chez des chats libres. Le reflexe digastrique fut induit par stimulation électrique du nerf dentaire inférieur. La stimulation réticulaire eut pour résultat l'inhibition de ce réflexe pendant la veille, le sommeil tranquille et le sommeil actif.     

Production of active and passive anaphylactic shock in the WBB6F1 mouse,a mast cell-deficient strain

Summary The role of mast cells in active and passive anaphylactic shock was examined using the WBB6F₁ mouse, a genetically mast cell-deficient strain. Lethal anaphylactic shock occurred at high incidence rates in mice actively sensitized to bovine serum albumin (BSA). The reaction was specific to BSA since the shock could not be elicited by human or guinea pig serum albumin in these animals. Lethal shock could be prevented by CV-3988 but not by cyproheptadine, which suggests that the shock is mediated by PAF but not by histamine and serotonin. Similarly, lethal shock was provoked by homologous antigens in mice which had been passively sensitized with allogeneic anti-benzylpenicilloyl (BPO) IgG₁ monoclonal antibody or with allogeneic or xenogeneic anti-BSA antiserum, but not in those sensitized with allogeneic anti-BPO IgE monoclonal antibody. These findings suggest that mast cells are not necessarily required for anaphylactic shock in the mouse.     

Deficiency of membrane-bound dipeptidyl aminopeptidase IV in a certain rat strain

Summary The activity of membrane-bound dipeptidyl aminopeptidase IV (EC 3.4.14.5) was found to be markedly reduced in the Fischer 344 rat strain compared with that in the Wistar strain. Analysis of membrane proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Ouchterlony immunodiffusion revealed the specific absence of this enzyme molecule in the Fischer 344 strain.     

Induction of IgG1 and IgE responses to protein-conjugated and unconjugated beta-lactam antibiotics in the mouse--efficacy of Freund's complete adjuvant

One or two injections two weeks apart of protein-conjugated penicillin G, cephalothin or cefmetazole emulsified with Freund's complete adjuvant were quite effective in producing anti-antibiotic antibodies of the IgE as well as of the IgG1 class in mice. Long-lasting and boostable production of both antibody classes was also obtained against unconjugated cephalothin or cefmetazole, though the positivity depended on the mouse strain.     

Dynorphin-degrading cysteine protease is highly specific for paired arginine residues.

The cleavage of dynorphin and three analogs containing paired basic residues by several proteases was investigated. The cysteine protease of neuroblastoma cells cleaved only the bond between Arg-Arg residues. Submandibular arginyl-endopeptidase, however, cleaved bonds between both Arg-Arg and Arg-Lys residues, and pancreatic trypsin at the carboxyl sides of both arginine and lysine residues. This shows that the cysteine protease is highly specific for paired arginine residues.     

Cardiac activation and inhibition involved in molting behavior of a spiny lobster

To study the molting behavior of the spiny lobster, electrical activity of the heart, stomach and skeletal muscles was recorded using in-dwelling electrodes. For 1–2 h before molting the heart rate gradually increases. At the same time shorter trains of stomach burst discharges frequently occur. The heart rate then declines and burst discharges of skeletal muscles begin. The skeletal bursts are regularly spaced (10–15 s intervals). A peristalsis pattern of short and long bursts continues for 10–20 min and is terminated by a few bursts corresponding to abdominal flips. The short skeletal burst is followed by a drop in heart rate. Bioassay using the isolated heart suggests that at the final stage of molting the blood contains some substance(s) which inhibit heart beat.