Communication between Tabhost Activity class and parent Activity Class which renders it

Question

I have a main class which renders tabwidget (tabhost) as follows:

intent = new Intent().setClass(this, Articles.class);

// Initialize a TabSpec for each tab and add it to the TabHost
spec = tabHost.newTabSpec("articles").setIndicator("Articles",
                      res.getDrawable(R.drawable.ic_tab_articles))
                  .setContent(intent);
tabHost.addTab(spec);

Now Articles class lists the articles inside first tab. Now when i click on any tab. I show the complete article. While showing this article I want to set visibility = gone of the tabHost. I would have used Database some way. But how the main Activity class will know that now i have clicked the Article and it is single article page.

Is there some way to find this? Or have a communication between tabhost activity class and the main class which renders or sets the Activity.