ISOLATION OF CYTOMEGALOVIRUS FROM THE BLOOD LEUCOCYTES OF A PATIENT WITH POST-TRANSFUSION MONONUCLEOSIS

Cytomegaloviæmia was demonstrated in an adult female patient who was suffering an episode of post-transfusion mononucleosis, as a consequence of the administration of a large volume of fresh blood. The primary nature of this infection was confirmed by demonstration of a complement-fixing antibody rise during the course of the illness to a final titre of 1 : 512. The virus was isolated from unpurified blood leucocytes, and again one week later from purified blood lymphocytes. Although a newly acquired infection with cytomegalovirus (CMV) has been demonstrated in this case, its ætiological role cannot be confidently assessed. The likely source of the virus is regarded as being one or more of the blood donors, and the possibility of a primary infection or a reactivation of a latent infection has been considered. Antibody titrations were carried out on eight sets of stored sera from patients with post-transfusion mononucleosis. Four of these showed a significant rise in antibody titre and only one set gave negative results. These results are consistent with the CMV infection having occurred in seven of these patients at the time of their episode of pest-transfusion mononucleosis. The suggestion is made that a revision of the criteria for the utilization of fresh blood for certain groups of patients may become necessary.     

Comparative evaluation of six techniques for determining the Michaelis-Menten parameters relating phenytoin dose and steady-state serum concentrations

Using randomly generated data within set error limits, the Michaelis-Menten parameters D_max and K_m relating steady-state serum phenytoin concentrations (C_ss) and dose (D) were determined by 5 graphical techniques and an iterative computer fit to the hyperbolic equation. The best mean estimates of D_max and K_m were provided by the latter. Assuming the experimental error to be in C_ss the results indicate that the most reliable graphical technique is that based on the equation C_SS = D_max -C_SS/D - K_m. However, considering its obvious simplicity and relative reliability the direct linear plot is recommended for clinical use.