Leukocytes in urine are not a dangerous condition, but they are a sign that you are suffering from an infection or damage. Leukocytes are white blood cells (WBC) that work with the immune system to defend against infectious disease. Damage to the kidneys, ureters, urethra or bladder can cause leukocytes to appear.
Empty vessels is a metaphor for a very shallow person whose thoughts and actions have no significant meaning. Such people are constantly talking or otherwise making noise in an attempt to get attention from other people. The more the person is ignored because he has no real input to give, the louder he will become.
1 The tongue of the wise utters knowledge aright; but the mouths of fools pour out folly. ~ Proverbs 15:2. 2  A gentle tongue is a tree of life; but perverseness therein is a breaking of the spirit. ~ Proverbs 15:4.  Whoso keeps his mouth and his tongue keeps his soul from troubles.