Can someone take over what appears to be abandoned property in Pittsburgh

The state or minicipality would have an interest in the party. That is who you would have to go through to get a name change on the title.

No. Property is never truly abandoned. Even if the previous owner no longer maintains the property or pays the taxes, there may still be a lender with an interest in the property. Or the local taxing authority may have an interest. If payments to the mortgage lender cease, then the lender may foreclose on the property. If there is no lender involved and taxes are not paid, the taxing authority will seize the property with a tax lien for sale at auction.

The ONLY way to legally take possession of a property is to purchase it legally. So you need to find the owner and work something out with them.

Agreed, a guy yesterday was determined to "take over" an abandoned property, it just doesn't work that way. Check with the assessors office to see who is paying the taxes

If you want to risk 20 years of living there taking care of the property and then HOPE the court will award it to you.

But all property is owned by someone. The recorder of deeds will list the owner and the tax department will know who if anyone is paying the taxes.
Also the recorder of deeds office will show ay loans on the property