Earwax of bacteria. Cerumen has been found to reduce the viability of a wide range of bacteria, including "Haemophilus influenzae", "Staphylococcus aureus", and many variants of "Escherichia coli", sometimes by as much as 99%. The growth of two fungi commonly present in otomycosis was also significantly inhibited by human cerumen. These antimicrobial properties are due principally to the presence of saturated fatty acids, lysozyme and, especially, to the slight acidity of cerumen (pH typically around 6.1 in normal individuals). Conversely, other research has found that cerumen can support microbial growth and some cerumen samples were found to have bacterial counts as
Substance P with inflammatory processes and pain. The original discovery of Substance P (SP) was in 1931 by Ulf von Euler and John H. Gaddum as a tissue extract that caused intestinal contraction "in vitro". Its tissue distribution and biologic actions were further investigated over the following decades. The eleven-amino-acid structure of the peptide was determined by Susan Leeman in 1971. In 1983, NKA (previously known as substance K or neuromedin L) was isolated from porcine spinal cord and was also found to stimulate intestinal contraction. The endogenous receptor for substance P is neurokinin 1 receptor (NK1-receptor, NK1R). It belongs to the