  Based on the second-order nonlinear theory of perturbations in non-zero
\Lambda flat cosmological models, we study the gravitational effects of local
inhomogeneities on cosmic microwave background (CMB) anisotropies. As the local
inhomogeneities we consider firstly large-scale dipole and quadruple
distributions of galaxies around us and next an isolated cluster-scale matter
distribution. It is found that, due to the second-order integral Sachs-Wolfe
effect, the north-south asymmetry of CMB anisotropies and non-Gaussian
signatures (in terms of scale-dependent estimators of kurtosis) in a spot-like
object are caused from these matter distributions along light paths. Our
theoretical results seem to be consistent with recent various observational
results which have been shown by Hansen et al., Eriksen et al., Vielva et al.
and Cruz et al.
