Spontaneous cervical artery dissections and implications for homocysteine

The vertebral artery between the atlas and axis vertebrae. Used with permission from Louis Sportelli, DC.

A, Role of N⁵, N¹⁰-methylenetetrahydrofolate reductase (MTHFR). B, Presumed relationship of MTHFR to homocysteine. Reproduced with permission.²⁵

A, Role of N⁵, N¹⁰-methylenetetrahydrofolate reductase (MTHFR). B, Presumed relationship of MTHFR to homocysteine. Reproduced with permission.²⁵

Catabolic pathways for glycine and other amino acids. Reproduced with permission.²⁵

Structure of collagen. a, Repeating tripeptide sequence Glycine-X-Proline or Glycine-X-Hydroxyproline adopts a left-handed helical structure with 3 residues/turn [Hyp used here]. b, Space-filling model of collagen helix shown in (a). c, Three of these helices wrap around one another with a right-handed twist. d, Three-standed collagen superhelix shown from one end, with glycine residues shown in black. Glycine, because of its small size, is required at the right junction where the 3 chains come into contact. Reproduced with permission.²⁵