Some remarks on the epsilon-expansion of dimensionally regulated Feynman diagrams

Some problems related to the construction of the E-expansion of dimensional ly regulated Feynman integrals are discussed. For certain classes of diagra ms, an arbitrary term of the E-expansion can be expressed in terms of log-s ine integrals related to the polylogarithms. It is shown how the analytic c ontinuation of these functions can be constructed in terms of the generaliz ed Nielsen polylogarithms.