beta-d-Glucan of Avena Coleoptile Cell Walls

A specific glucanase was used to liberate a noncellulosic beta-d-glucan from isolated cell walls of Avena sativa coleoptile tissue. Cell walls of this tissue contain as much as 7 to 9 mg of glucan/100 mg of dry wall. Because of the specific action pattern of the enzyme, a linkage sequence of.. 1 --> 4 Glc 1 --> 3 Glc 1 --> 4 Glc.. is indicated and the predominance of trisaccharide and tetrasaccharide as hydrolytic products suggests a rather regular repeating pattern in the polysaccharide. The trisaccharide and the tetrasaccharide are tentatively identified as 3-O-beta-cellobiosyl-d-glucose and 3-O-beta-cellotriosyl-d-glucose, respectively. Recovery of these oligosaccharides following glucanase treatment of native wall material was feasible only after wall-bound glucosidases were inactivated. In the absence of enzyme inactivation the released fragments were recovered as glucose. The beta-d-glucan was not extracted from walls by either hot water or protease treatment.Cell walls prepared from auxin-treated Avena coleoptile segments yielded less glucan than did segments incubated in buffer suggesting an auxin effect on the quantity of this wall component. No IAA-induced change in the ratio of the trisaccharide and tetrasaccharide could be detected, suggesting no shift in the 1,3 to 1,4 linkage ratio. While the enzyme acts directly on the beta-d-glucan, no elongation response was apparent when Avena sections were treated with the purified glucanase. The presence of the glucan was not associated with any wound response which could be attributed to the preparation of coleoptile segments. The relationship of glucan metabolism to auxin growth responses is discussed.

Arginine catabolism by Mycoplasma meleagridis and its role in pathogenesis

A thin-layer chromatography technique was used to study the arginine metabolism of Mycoplasma meleagridis. The technique reflected the enzyme activity of the dihydrolase pathway through detection of readily visible end products on X-ray film. Strains of M. meleagridis differing in their pathogenicity for turkeys did not vary in arginine metabolism. In addition, no significant difference was observed in plasma arginine concentrations between M. meleagridis-infected and uninfected poults. It was concluded that the pathogenesis of M. meleagridis infection in turkeys was not based on its competition with the host for arginine.

Morphology and growth cycle of Mycoplasma meleagridis viewed by scanning-electron microscopy

The three-dimensional structure of Mycoplasma meleagridis strain RY-39A was studied by scanning-electron microscopy. The morphologic forms observed between 12 hours and 7 days suggest that the organism undergoes a sequential metamorphosis in its development. Single rounded forms in lag phase give rise to larger cells and filaments in the log phase, which fragment into coccus forms in the late stationary phase.

Antibodies against human lymphokines: I. Methods for induction of antibodies capable of neutralizing stable (alpha) and unstable (beta) lymphotoxins released in vitro by activated human lymphocytes

Various methods were employed to induce antibodies in rabbits that were capable of neutralizing different families of lymphotoxins (LT). Both stable (alpha-LT) and unstable (beta-LT) molecules, released by activated human lymphocytes in vitro, were neutralized. The different LT families were first separated into their respective groups by physical-chemical methods. Immunization with small quantities of antigen yielded a high percentage of responder animals. Techniques were developed for eliciting alpha-LT antibodies using as little as 2--3 ml of a cell-free supernatant. The situation was more difficult, however, when the unstable beta-LT molecules were employed as antigens. We found that because of the low concentration and lability of beta-LT in supernatants, the immunizing dose had to be: a) handled rapidly, b) larger than that used with the alpha-LT, and c) injected at closer intervals and over a longer immunization protocol. Physical-chemical studies supperted the concept that the LT-neutralizing activity in the immune serum was immunoglobulin.

Antibiotic egg injection to eliminate disease. I. Effect of injection methods on turkey hatchability and Mycoplasma meleagridis infection

Mycoplasma meleagridis infection in turkey hatching eggs was eliminated by injecting eggs with a combination of tylosin and gentamicin. Hatched F1 and F2 progeny remained free of egg-transmitted infection. Contact exposure was experienced in one negative flock. Of the preincubation injection procedures studied, a drilled hole on the small end of the egg was the inoculation site easiest to administer and best tolerated by the embryo. The embryo can tolerate a dose of gentamicin sulfate injected at 10 days of incubation that would be toxic if administered before incubation. Requirements for maintaining progeny free of infection are discussed.

Lymphocyte effector molecules: an vitro production method for obtaining liter volumes of supernatants from mitogen-stimulated human lymphocytes

An in vitro method has been developed utilizing phytohemagglutinin (PHA) activated lymphocytes obtained from human tonsils and adenoids which permit the accumulation of multi-liter quantities of cell-free supernatants containing lymphotoxin and other lymphocyte effector molecules (LEM). An enriched media is employed which contains a large molecular weight, heat stable bovine serum fraction which supports lymphoid cell activation and levels of LEM secretion equal to that of cultures maintained in medium supplemented with whole serum. Elimination of whole serum from the media greatly reduces overall protein concentrations and facilitates concentration and purification studies. Various technical aspects of these cultures have been examined, i.e.: 1) cell concentration, 2) kinetics of LT production over a ten-day period, 3) mitogen dosage, and 4) types of media. Supernatants can be harvested repeatedly from a single culture over the ten day period, thus doubling the yield of LEM collected from a single culture.

Image processing system using incoherent image feedback

By combining a TV system with suitable optical systems an image processor which uses the technique of image feedback is constructed. The special features are the simplicity of the arrangement and the flexibility for the treatable input images as well as the ability as a real-time processor. Results for ghost image elimination under several conditions and for sharping of images are shown.

Injecting antibiotics into turkey hatching eggs to eliminate Mycoplasma meleagridis infection

Hatching eggs from a commercial strain of turkeys infected naturally with Mycoplasma meleagridis were injected before incubation with various doses of tylosin, gentamicin, erythromycin, and chloramphenicol, individually and in combination. The antibiotics were inoculated into the albumen through a hole made in the small end of the egg. Gentamicin was the only drug consistently effective in reducing infection. With inoculation by the procedure described, the embryos tolerated several dose levels of gentamicin, tylosin, and erythromycin well.

Protective quality of an aluminum hydroxide-absorbed broth bacterin against infectious coryza

Various aspects of immunity induced by a merthiolate-inactivated, aluminum hydroxide-absorbed chicken meat infusion (CMI) broth bacterin prepared from Haemophilus gallinarium were studied. A bacterin dose of 10-8 colony-forming units (CFU)/ml was the minimal dose which protected a significant number of chickens against intrasinus challenge with live organisms. This finding simplifies production procedures because yields of 10-8 CFU/ml of CMI broth are routinely obtained. A significant number of chickens vaccinated with the bacterin were immune to intrasinus challenge through 9 months postvaccination. On a comparative basis, an egg-yolk bacterin prepared from the same strain protected for only 3 months. Birds vaccinated with broth bacterins prepared from 2 strains of H gallinarum (17756 and M) which shared common surface antigens were immune to intrasinus inoculation with the homologous but not to the heterologous organisms. Preliminary data indicated that the broth bacterin prevented a sharp decrease in egg production when the immunity of vaccinated birds was challenged (instrasinus) at the height of egg production.