Print fields a different node
Are you loading the node first? If you are not getting anything returned then it's probably because $node isn't set. Also is the 'News node' a node type of article?

I would start by trying to retrieve the node information first:

$node = node_load(arg(1));
var_dump($node); 


Also I think your field_get_items is not working as your entity type is 'page' but you are inside a check for a node type of article try:

$news_header = field_get_items('node', $node, 'group_header');