  The contributions $\propto n_f$ to the $O(\alpha_s^3)$ massive operator
matrix elements describing the heavy flavor Wilson coefficients in the limit
$Q^2 \gg m^2$ are computed for the structure function $F_2(x,Q^2)$ and
transversity for general values of the Mellin variable $N$. Here, for two
matrix elements, $A_{qq,Q}^{\sf PS}(N)$ and $A_{qg,Q}(N)$, the complete result
is obtained. A first independent computation of the contributions to the
3--loop anomalous dimensions $\gamma_{qg}(N)$, $\gamma_{qq}^{\sf PS}(N$ and
$\gamma_{qq}^{\sf NS,(TR)}(N)$ is given. In the computation advanced summation
technologies for nested sums over products of hypergeometric terms with
harmonic sums have been used. For intermediary results generalized harmonic
sums occur, while the final results can be expressed by nested harmonic sums
only.
