Projection as a defense mechanism.

Reviews the research related to the hypothesized defensive functions of projection (e.g., attributing one's own undesirable traits to others). Contrary to the predictions, it was found that (a) there is no evidence that projection protects persons from the awareness that they possess undesirable traits, (b) the use of projection follows only some of the predicted patterns, (c) there is no evidence that projection results in undesirable traits being reevaluated as more positive, and (d) there is no reliable or strong evidence that projection results in stress reduction. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Isolation and characterization of melanin-producing (mel) mutants of Vibrio cholerae

Vibrio cholerae strain Htx-3, a hypertoxinogenic mutant of V. cholerae 569B Inaba, produces a dark brown pigment under certain growth conditions, whereas strain 569B does not. We investigated the biochemical basis for this pigment production and the possible relationships between pigmentation and other phenotypic properties in V. cholerae. After mutagenesis of V. cholerae 569B with N-methyl-N'-nitro-N-nitrosoguanidine, 28 independently derived pigment-forming (mel) mutants were isolated and characterized. The mel mutants frequently differed from wild type in toxinogenicity or motility and occasionally differed in other phenotypic traits. Individual mel mutants differed from wild type both in the amount of toxin produced and in the growth conditions optimal for toxin production. It has not yet been established whether multiple phenotypic changes in individual mel mutants represent pleiotropic effects of single mutations or induction of multiple mutations by N-methyl-N'-nitro-N-nitrosoguanidine or both. Production of pigment by mel mutants occurred at temperatures from 22 to 40 degrees C, was inhibited by anaerobiosis, and was stimulated by supplementation of growth media with the amino acid precursors of melanin (l-phenylalanine, l-tyrosine, or l-tyrosine plus l-cysteine). The pigment possessed several other properties reported for microbial melanins. We conclude that a biochemical pathway for melanin production is present in V. cholerae, that this pathway cannot be fully expressed in wild-type strain 569B, and that mutations in the gene(s) which we have designated mel can permit hyperproduction of melanin under appropriate conditions.     

Preparation of dodecylamine and 6-aminohexanoic acid from petroselinic acid

A procedure is given for the ozonization of petroselinic acid, chemical reduction of the ozonides to aldehydes, formation of oximes, and catalytic hydrogenation of the oximes using Raney nickel in the presence of ammonia, to yield 48% dodecylamine and 44% 6-aminohexanoic acid calculated on the amounts theoretically available from the wt of petroselinic acid. The ultimate analyses, melting points, and distribution coefficients between ethyl ether and water of lauraldehyde and adipaldehydic acid oximes were determined. The infrared spectra of lauraldehyde oxime, adipaldehydic acid oxime, and 6-aminohexanoic acid are given and interpreted. Presented at the AOCS meeting in New Orleans, La., 1962. A laboratory of the Southern Utilization Research and Development Division, Agricultural Research Service, U.S.D.A., New Orleans, La.     

A comparison of ketamine and the combination ketamine-xylazine for effective surgical anesthesia in the rabbit

Ketamine alone and the combination ketamine-xylazine were evaluated as surgical anesthetics in rabbits. It was found that ketamine alone provided inadequate analgesia for ventral abdominal incisions or exposure of the femur. The combination of xylazine with ketamine did provide adequate enalgesia for both surgical procedures.     

Lipid content and fatty acid composition of heart and muscle of the BIO 82.62 cardiomyopathic hamster

Microscopic and analytical studies of the lipids in the heart and muscle of the BIO 82.62 myopathic hamsters and age-matched normal animals at the average ages of 33, 67, and 108 days were performed. Microscopic examinations did not show increased lipid depositions in the hearts of the diseased animals as was found in the BIO 14.6 strain. No consistent differences in the lipid content of the cardiomyopathic hamsters (BIO 82.62) and age-matched controls were observed in the three age groups except in the cholesterol content of muscle. Cholesterol increased significantly (P less than 0.01) in the 67 and 108 day old animals. This increase elevated the cholesterol/phospholipid ratio. Analysis of the fatty acid composition of triglycerides showed that the cardiomyopathic hamsters store more saturated fatty acids in both heart and muscle than do their normal counterparts. The abundance of more saturated fatty acids may imply that either the desaturation mechanism is altered in the diseased animals or that unsaturated fatty acids are preferentially utilized in other processes.     

Failure of axially compressed frangible joints in cylindrical shells

A computer program for the analysis of stress, nonlinear collapse and bifurcation buckling of hybrid bodies of revolution (BOSOR6) is used for the prediction of failure of axially compressed cylinders containing frangible joints. Plasticity and moderately large deflections are included in the analytical models. The structure in the immediate neighborhoods of the frangible joint notches is modeled with use of eight-node solid isoparametric finite elements of revolution and the rest of the structure is modeled with use of computationally efficient thin shell elements.Theoretical predictions are compared to test results. Certain aspects of the test specimens and boundary conditions remain unknown, and parameters in the analytical models are established and varied in order to reveal what these test conditions must have been. For reasonable values of these parameters, theoretical and experimental joint failure loads agree to within 2%.     

Altered expression of Ly-49 receptors on NK cells developing in mixed allogeneic bone marrow chimeras

Ly-49 molecules are used by NK cells to distinguish 'self' from 'non-self', but the determinants of Ly-49 expression that allow this distinction to be made are not understood. The education of NK cells for self/non-self recognition was studied in murine mixed allogeneic bone marrow chimeras, in which NK cells are of both host and donor origin. Marked alterations in Ly-49 receptor expression were observed on both host and donor NK cells developing in BALB/c --> B6 mixed chimeras. Ly-49A and Ly-49G2 expression was lower on host B6 NK cells of mixed chimeras compared to non-transplanted B6 controls. Among donor BALB/c NK cells, Ly-49C expression levels were reduced, but the proportion of Ly-49C+ cells was increased, whereas Ly-49G2 expression was up-regulated compared to non-transplanted BALB/c controls. Thus, Ly-49 expression on donor and host NK cells developing post-bone marrow transplantation evolves toward the expression pattern of the host and donor strains respectively, due to the presence of the allogeneic MHC. In vitro functional NK cell assays showed that donor NK cells in mixed chimeras were not tolerant to host antigens and that host NK cells were not tolerant to the donor. Our data are consistent with a model in which MHC expression in the environment has a dominant down-regulating effect on the expression of Ly-49 molecules that recognize those MHC molecules, regardless of whether they are self or allogeneic. This down-regulation, combined with the limited repertoire of Ly-49 molecules, may not be sufficient to allow NK cells to be tolerant of MHC antigens of a fully MHC-mismatched allogenic strain.