Not getting the concentration right
At our practice, we frequently recommend vitamin B12 injections for patients who have difficulty adequately absorbing the vitamin through diet or oral supplements
The left ventricle was perfused intra-aortically with 250 ml of ice-cold, 0.1 M buffer phosphate [containing (mM): 137 NaCl, 2.7 KCl, 10 Na 2 HPO 4 , and 2 KH 2 PO 4 ] with heparin (10000 U/L), pH 7.4, at a flow rate of 1825 ml/min, followed by 4% paraformaldehyde +12% picric acid solution until transparent liquid flowed from the right ventricle
Lipton SA, Choi YB, Pan ZH, Lei SZ, Chen HS, Sucher NJ, Loscalzo J, Singel DJ, Stamler JS (1993) A redox-based mechanism for the neuroprotective and neurodestructive effects of nitric oxide and related nitroso-compounds