Perceived and Actual Breast Cancer Risk

Perceived risk can influence health behaviors. Studies using various populations and breast cancer risk bias assessment methods have identified both risk over- and underestimation. Among 1803 women in primary care settings, 47 percent were at average epidemiologic risk (Gail-calculated relative risk ±50 percent of age-adjusted population average) and 55 percent perceived themselves to be at average risk (compared to same-age others) but there were mismatches or ‘biases’: 31 percent underestimated personal risk; 26 percent overestimated. Multiple logistic regression revealed that smokers were more likely to overestimate risk. Overestimation decreased with more education. Mammography use did not independently predict perception bias but, among never-screened women aged over 40 years, those contemplating mammograms were most likely to overestimate risk; precontemplators were most likely to underestimate. Implications for research and intervention are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66881/2/10.1177_135910539800300203.pd

A novel variant of the immunoglobulin fold in surface adhesins of Staphylococcus aureus: crystal structure of the fibrinogen-binding MSCRAMM, clumping factor A

We report here the crystal structure of the minimal ligand-binding segment of the Staphylococcus aureus MSCRAMM, clumping factor A. This fibrinogen-binding segment contains two similarly folded domains. The fold observed is a new variant of the immunoglobulin motif that we have called DE-variant or the DEv-IgG fold. This subgroup includes the ligand-binding domain of the collagen-binding S.aureus MSCRAMM CNA, and many other structures previously classified as jelly rolls. Structure predictions suggest that the four fibrinogen-binding S.aureus MSCRAMMs identified so far would also contain the same DEv-IgG fold. A systematic docking search using the C-terminal region of the fibrinogen γ-chain as a probe suggested that a hydrophobic pocket formed between the two DEv-IgG domains of the clumping factor as the ligand-binding site. Mutagenic substitution of residues Tyr256, Pro336, Tyr338 and Lys389 in the clumping factor, which are proposed to contact the terminal residues (408)AGDV(411) of the γ-chain, resulted in proteins with no or markedly reduced affinity for fibrinogen

A novel variant of the immunoglobulin fold in surface adhesins of Staphylococcus aureus: crystal structure of the fibrinogen-binding MSCRAMM, clumping factor A

We report here the crystal structure of the minimal ligand-binding segment of the Staphylococcus aureus MSCRAMM, clumping factor A. This fibrinogen-binding segment contains two similarly folded domains. The fold observed is a new variant of the immunoglobulin motif that we have called DE-variant or the DEv-IgG fold. This subgroup includes the ligand-binding domain of the collagen-binding S.aureus MSCRAMM CNA, and many other structures previously classified as jelly rolls. Structure predictions suggest that the four fibrinogen-binding S.aureus MSCRAMMs identified so far would also contain the same DEv-IgG fold. A systematic docking search using the C-terminal region of the fibrinogen γ-chain as a probe suggested that a hydrophobic pocket formed between the two DEv-IgG domains of the clumping factor as the ligand-binding site. Mutagenic substitution of residues Tyr256, Pro336, Tyr338 and Lys389 in the clumping factor, which are proposed to contact the terminal residues (408)AGDV(411) of the γ-chain, resulted in proteins with no or markedly reduced affinity for fibrinogen