The previously described hybrid plasmid pC7 which carries lacI+ O+Δ(Z)Y+ A+ on a 12.3 × 106‐Mr DNA fragment [Teather et al. (1978) Mol. Gen. Genet. 159, 239–248] was partially digested with the restriction endonuclease EcoRI under conditions reducing the recognition sequence to ↓ d(A‐A‐T‐T) and ligated to the vector pBR322. lacY‐carrying inserts of various sizes (Mr, 1.5–4.7 × 106) were obtained. Hybrid plasmid pTE18 (2300‐base‐pair insert) carries part of the I (repressor) gene, the promotor‐operator region, part of the Z (β‐galactosidase) gene, the Y (lactose carrier) gene and part of the A (transacetylase) gene. Upon induction of pTE18‐harbouring strains the Y‐gene product is expressed at a nearly constant rate for several generations and accumulates to a level of 12–16% of the total cytoplasmic membrane protein. Integration into the membrane leads to active carrier as judged by binding and transport measurements.

The wrists are affected in the long-term in 90% of people with rheumatism and are often (42%) the first manifestation of a destructive disease. The functionality of the wrist and the whole hand is of great importance because in many cases loss of function of the wrists leads to severe limitations. Local and operative treatment of the wrist in rheumatoid arthritis (RA) is one of the main duties in rheuma-orthopaedics. For operative treatment there is a finely tuned differential therapeutic spectrum available. The diagnostic indications take the local and total pattern of affection, the current systemic therapy as well as patient wishes and patient compliance into consideration. In the early stages according to LDE (Larsen, Dale, Eek), soft tissues operations such as articulo-tenosynovectomy (ATS) are most commonly carried out. In further advanced stages osseus stabilisation must often be performed. At this point a smooth transition from partial arthrodesis to complete fixation is possible. After initial euphoria, arthroplasty of the wrist is being increasingly less used for operative treatment due to the unconvincing long-term results and high complication rate. With reference to the good long-term results of all operative procedures, in particular early ATS with respect to pain, function and protection of tendons, after failure of medicinal treatment and persistence of inflammatory activity in the wrist, patients should be transferred to an experienced rheuma-orthopaedic surgeon.

Local invasive procedures represent possibilities for the treatment of arthritic swollen joints without surgical interventions, when general measures alone are not successful and intra-articular injections are of utmost importance in this context. The differences between degenerative and rheumatologic diseases must be considered as well as possible specific adverse reactions, side effects and contraindications. The technical intervention is performed according to the guidelines of scientific societies such as the Scientific Medical Profession Society (AWMF). Cortisone and radiosynoviorthesis/chemosynoviorthesis are suitable for activated rheumatic and degenerative joints, low-grade radiation therapy or infiltration of hyaluronic acid is recommended for relief in cases of arthritic inflammation. The combination of arthroscopic synovectomy and subsequent radiosynoviorthesis in the early stages of rheumatically swollen joints show the best results with respect to regression prophylaxis and slowing the process of rapidly progressing destruction of chondral surfaces and distension of the capsules and ligaments.