Colony-forming ability of ataxia-telangiectasia skin fibroblasts is an indicator of their early senescence and increased demand for growth factors

Homogenate transglutaminase (TGase)-specific activity of guinea pig peritoneal macrophages was measured under a variety of conditions that stimulate or activate macrophages. Resident peritoneal macrophages had low levels of TGase as compared with oil-elicited inflammatory macrophages, which showed 30- to 100-fold greater enzyme activity. Immunofluorescent staining with specific antibody to purified enzyme showed a corresponding increase in staining intensity in subpopulations of inflammatory macrophages. Stimulation of macrophages with bacterial endotoxin, lymphokine, or Lotus tetragonolobus lectin resulted in increased TGase-specific activity. Cystamine, an inhibitor of the enzyme, reduced TGase activity, reduced lymphokine-mediated migration inhibition, and inhibited Fc-mediated phagocytosis. The substrate inhibitors, methylamine and dansylcadaverine, also inhibited Fc-dependent phagocytosis. These results suggest a possible role for TGase in macrophage activation and in receptor-dependent phagocytosis.     

Escherichia coli mutants completely deficient in adenosylmethionine decarboxylase and in spermidine biosynthesis.

Mutants of Escherichia coli deficient in adenosylmethionine decarboxylase, an enzyme in the biosynthetic pathway for spermidine, were isolated after mutagenesis of E. coli K 12 with N-methyl-N-nitro-N-nitrosoguanidine or with the bacteriophage Mu. The mutated gene, designated speD, is at 2.7 min on the E. coli chromosome map. In several of the mutants resulting from Mu insertion both adenosylmethionine decarboxylase activity and spermidine were undetectable. The absence of spermidine from speD strains proves the essential role of adenosylmethionine decarboxylase in the biosynthetic pathway for spermidine. Despite the complete absence of spermidine, these mutants grew at 75% of the wild type rate.     

Attitudes of Genetics Professionals Toward the Return of Incidental Results from Exome and Whole-Genome Sequencing

Professional recommendations for the return of results from exome and whole-genome sequencing (ES/WGS) have been controversial. The lack of clear guidance about whether and, if so, how to return ES/WGS incidental results limits the extent to which individuals and families might benefit from ES/WGS. The perspectives of genetics professionals, particularly those at the forefront of using ES/WGS in clinics, are largely unknown. Data on stakeholder perspectives could help clarify how to weigh expert positions and recommendations. We conducted an online survey of 9,857 genetics professionals to learn their attitudes on the return of incidental results from ES/WGS and the recent American College of Medical Genetic and Genomics Recommendations for Reporting of Incidental Findings in Clinical Exome and Genome Sequencing. Of the 847 respondents, 760 completed the survey. The overwhelming majority of respondents thought that incidental ES/WGS results should be offered to adult patients (85%), healthy adults (75%), and the parents of a child with a medical condition (74%). The majority thought that incidental results about adult-onset conditions (62%) and carrier status (62%) should be offered to the parents of a child with a medical condition. About half thought that offered results should not be limited to those deemed clinically actionable. The vast majority (81%) thought that individual preferences should guide return. Genetics professionals’ perspectives on the return of ES/WGS results differed substantially from current recommendations, underscoring the need to establish clear purpose for recommendations on the return of incidental ES/WGS results as professional societies grapple with developing and updating recommendations.