Abstract: In an injection needle 1 with a first cut surface 3 formed by simply cutting a cylinder bias and second and third cutting surfaces 4 and 5 provided by cutting the first cut surface 3 so as to have a chevron shape which slopes down toward the outside-diameter side in a bilateral cutting width direction, by further reducing an insertion width, not only skin damage during insertion but also insertion pressure are reduced so that an insertion pain is eliminated and early recovery from the injection mark is realized. The outer circumferential surface of the cylinder of the injection needle with the first, second, and third cut surfaces 3, 4, and 5 formed is provided as a curved surface 2 curved in the around-the-needle-axis direction and axial center direction so as to form an arc-shaped outer circumferential edge without a sharp corner part, whereby damage to the inner wall of a blood vessel is avoided during insertion.

Abstract: The invention is concerned with tricyclic compounds of the formula ##STR1## wherein R.sup.1 is a hydrogen atom or a carboxy-protecting radical; R.sup.2 is a hydrogen atom or a lower alkyl radical which may be substituted with a halogen atom; R.sup.3 and R.sup.4 independently are a hydrogen atom or a lower alkyl radical which may be substituted with a hydroxy radical or a substituted or unsubstituted amino radical; X is a halogen atom; and R.sup.5 and R.sup.6 are independently a hydrogen atom or a lower alkyl radical which may be substituted with a hydroxy radical, a lower alkoxy radical or a substituted or unsubstituted amino radical; or R.sup.5 and R.sup.6, taken together with the adjacent nitrogen atom, may form a 5 to 7 membered heterocyclic ring which may be substituted with one or more substituents at the carbon atom(s), and the heterocyclic ring may further contain --NR.sup.7 --, --O--, --S--, --SO--, --SO.sub.2 -- or --NR.sup.7 --CO--, and also R.sup.