Android Execute Asyntask within another class from another class

I have a class inside which there is another class that extends AsyncTask. As,

public class Dashboard extends Activity {
 -------------

 --------------
 --------------
  public class getUnreadMessageCount  extends AsyncTask {
    protected JSONObject doInBackground(){
     *********some database stuff************
    }
    protected void onPostExecute(JSONObject json) {
       count = Integer.parseInt(json.getString("messsage_count"));
       // Set Text to the textview
       messageCount.setText(count); 

    }

  }
}

Now I am using GCMIntentService Class for notification. How can I call and execute the getUnreadMessageCount in the following

private void sendNotification(String content_id, int type, String msg) {


}

I tried as

private void sendNotification(String content_id, int type, String msg) {
    Dashboard dashboard = new Dashboard;
    dashboard.Dashboard dashboard---- 
}

But it does not work. How could I solve this problem.