Control Gui elements from Java / Mex externally using separate thread ??

Hello, I just want to ask whether it is possible to control / update a Matlab GUI object from Java or Mex without using the parallel computing toolbox. I add first codes to describe what I desires.

% init
hf = figure('unit', 'pixel', 'position', [300 300 300 150]);
tv1 = 0;
tv2 = 0;
ht1 = uicontrol('parent', hf, 'string', num2str(tv1), 'style', 'text', 'unit', 'pixel', 'position', [50 100 150 40]);
ht2 = uicontrol('parent', hf, 'string', num2str(tv2), 'style', 'text', 'unit', 'pixel', 'position', [50 30 150 40]);

% start the external thread to refresh the counter in textbox 1 without
% interrupting 
% -------------------------- %
% java / mex here
% -------------------------- %

% refresh the text box 2
while true
    tv2 = tv2 + 1;
    set(ht2, 'string', num2str(tv2));
    pause(0.1)
end

[Guillaume]

I strongly doubt it. Note that even with multithreaded code, only one thread should ever access the UI.