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.
Those who have one foot in the canoe, and one foot in the boat, are going to fall into the river.. (Native American proverb, Tuscarora). Seven trades but no luck. (Arabic proverb). An idle man is up to no good. (Corsican proverb).