Arkansas inmate Eric Atkisson appeals after the district court 1 granted summary-judgment for defendants in Atkisson’s action under 42 U.S.C. § 1983 for deliberate indifference to his serious medical needs. His principal argument on appeal is that his motions for appointment of counsel were denied for insufficient reasons. The merits of those orders are not properly before us, however, because they were issued by the magistrate judge and Atkisson did not timely seek district-court review, see Daley v. Marriott Int’l, Inc., 415 F.3d 889, 893 n. 9 (8th Cir. 2005); and any error concerning his motions for extensions of time to object to the magistrate judge’s rulings were harmless, because they did not affect Atkisson’s substantial rights in the circumstances of this case, see Fed. R.Civ.P. 61. Finally, liberally construing Atkisson’s submissions on appeal as including a merits challenge to the grant of summary judgment (which appellees have fully briefed), we have conducted careful de novo review, see Meuir v. Greene Cnty. Jail Emps., 487 F.3d 1115, 1118 (8th Cir. 2007), and we affirm the grant of summary judgment for the reasons explained by the district court.

The judgment of the district court is affirmed. See 8th Cir. R. 47B.