How to filter those TCP packets on Wireshark/Ethereal

Packets that I want to see (just samples, there are thousands of them):

314 2.280146    192.168.0.1 192.168.0.2 TCP ah-esp-encap > 11188 [PSH, ACK] Seq=1 Ack=1 Win=65535 Len=121
316 2.290003    192.168.0.2 192.168.0.1 TCP 11188 > ah-esp-encap [PSH, ACK] Seq=1 Ack=122 Win=5840 Len=98

Packets that I want to be filtered out:

311 2.279182    192.168.0.1 192.168.0.2 TCP ah-esp-encap > 11188 [SYN] Seq=0 Win=65535 Len=0 MSS=1460
312 2.279404    192.168.0.2 192.168.0.1 TCP 11188 > ah-esp-encap [SYN, ACK] Seq=0 Ack=1 Win=5840 Len=0 MSS=1460
312 2.279404    192.168.0.2 192.168.0.1 TCP 11188 > ah-esp-encap [SYN, ACK] Seq=0 Ack=1 Win=5840 Len=0 MSS=1460
312 2.279404    192.168.0.2 192.168.0.1 TCP 11188 > ah-esp-encap [SYN, ACK] Seq=0 Ack=1 Win=5840 Len=0 MSS=1460

How to write that filter?
I think the main difference between them is that I want only the PSH packets, and I want to exclude the SYN packets. I looked at the reference but I don't understand it yet.