Pharmaceutical preparations for use in the prevention and treatment of joint, tendon and skin diseases, namely, degenerative arthritis, arthritis, osteoarthritis, tendonitis, psoriasis, psoriasic arthritis, ulcerous colitis, Crohn's disease, Alzheimer, arteriosclerosis; veterinary preparations for use in the prevention and treatment of joint diseases in animals; dietetic food adapted for medical use and nutritional supplement made of mucopolysaccharides