GLOBAL MARKETS-Stocks and euro hit by German data, U.S. results

* Wall Street lower in afternoon trading * Downbeat German Ifo survey weighs on euro, European shares * Amazon.com, Visa down after disappointing results * Russian shares and bonds fall (Updates with oil settlement prices) By Caroline Valetkevitch NEW YORK, July 25 (Reuters) - Some disappointing U.S. earnings, including those of Amazon.com, and weak German economic data pressured world stock markets on Friday, while the euro clung to an eight-month low against the U.S. doll