Here's one approach you could use to re-order the elements of A in a new cell, C:
% Assuming A and B are already loaded into your Workspace
C = cell(size(B));
for i = 1:size(A, 2) % for each element in A
C(find(strcmp(B, A{1,i}))) = {A{2,i}}; % Put the element from A in the right place in C
end
C(cellfun('isempty',C)) = []; % Remove empty elements
Here, we make C the same size as B, put every element from A in the correct place in C, and then remove the empty elements, so C ends up holding only the matches from A to B.
Note: I ran this with your data, and it appears that some uid's in A are not present in B (only 16 of the 23 elements in A were matched to indexes in B). So, in this case, C becomes a 1x16 cell.
