Panmure Gordon views AstraZeneca's latest setback as a significant buying opportunity, sticking with its forecasts and 'buy' recommendation.The drugs giant was issued with a response from the US Food & Drug Administration (FDA) requesting additional analysis of data on Brilinta, causing a delay for the blood-thinning drug.While the company remains confident that a new clinical trial is not required - reducing the downgrade risk - the broker says that Astra remains its top pick and expects further upgrades to drive the share price.Target price is 3,600p and the 'buy' rating remains unchanged.While Aggreko has upped its full-year profit forecasts, Peel Hunt says that despite the upgrades secured in the year, the shares look up with events. Andrew Nussey says the International Power Projects business continues to deliver robust growth, the North American division remains strong and conditions in the Local markets are improving.However, despite strong management, excellent global positions and inherent cash generation capabilities, the broker feels the rating is "looking full," trading at 18 times 2011 earnings.The target price of 1,600p is maintained, along with a 'hold' recommendation.Panmure Gordon says that Punch Taverns remains a "compelling special situation," after its first quarter trading update Friday.The broker says the pub and restaurant group remains on track to meet full year expectations and consensus estimates of £124m for pre-tax profit aren't expected to change.It keeps its 'buy' recommendation and 105p target price.Broker Peel Hunt also remains confident in the business, noting that group cash is consistent, with cash and bonds at £274m."Today's slightly more positive trading report has little relevance to the value story at Punch, which has everything to do with a clear separation of the value of Spirit and group cash," the broker says. It also rates the shares a 'buy', but with a slightly less ambitious 91p target.