Is a purchase by two attorneys of a note secured by a first deed of trust an 'adverse interest' within the meaning of rule 4?

In Ames v. State Bar (1973) 8 Cal.3d 910, 917--919, 106 Cal.Rptr. 489, 506 P.2d 625, we held that a purchase by two attorneys of a note secured by a first deed of trust on a piece of property was the acquisition of an 'adverse' interest within the meaning of rule 4 since their clients held the second deed of trust on the same property. We noted that the interest was adverse for two reasons. First, the attorneys were in the position to proceed with a sale under the senior lien which would extinguish the client's junior lien. (Id., at pp. 918--919, 106 Cal.Rptr. 489, 506 P.2d 625.) Second, the attorneys had obtained an interest in the subject matter of the litigation for which they had been retained, 'contrary to their duty of undivided loyalty to their client . . ..' (Id., at p. 919, 106 Cal.Rptr. at p. 495, 506 P.2d at p. 631.)