Inpatient admissions for interventional radiology: philosophy of patient management

As an alternative to performing interventional radiology on inpatients under the care of internists and surgeons, the authors have established a cardiovascular radiology admitting service for well-screened, elective patients. The patients are admitted under the care of a cardiovascular radiology fellow and a staff physician. From April 1982 to December 1983, 133 patients were admitted to the service. Patients are cared for in a surgical ward or in an intermediate unit, as determined by the clinical situation. Advantages of this approach include a broader patient referral base, improved rapport with clinical colleagues and patients, improved follow-up data, and rapid evaluation and treatment, resulting in short hospital stays. The major disadvantages involve the commitment of time and staff necessary to provide quality care. The concept of the interventional radiologist in the role of admitting physician has important implications in terms of negotiations for additional financial compensation, commensurate with the skill and time required for performing these procedures and caring for the patient.     

Antibody-targeted polymer-doxorubicin conjugates with pH-controlled activation

The paper is dealing with the synthesis and properties of new non-targeted or antibody-targeted polymer drug conjugates, bearing doxorubicin (DOX) attached via a spacer susceptible to pH-controlled hydrolysis (hydrazone conjugates), designed as anticancer drugs facilitating site-specific therapy. These conjugates are stable in a pH 7.4 buffer, modeling conditions during transport in the body, but release DOX and activate it inside target cells as a result of pH changes when going from outside to inside the cells. Conjugates containing an antibody directed against T lymphocytes bind effectively and specifically T cell lymphoma EL 4 cells. Cytotoxicity of the hydrazone conjugates is higher than that of classic conjugates, depending on the detailed structure of the polymer, the spacer between the drug and polymer carrier and method of antibody conjugation. Cytotoxicity of some of the conjugates is comparable even with that of the free drug. In both protective and therapeutic regimes of drug administration, the in vivo anti-tumor activity of the conjugates containing DOX was enhanced with long-term survivors (T-cell lymphoma EL 4, C57BL/6 mice) in comparison with much less effective free DOX or a classic P(N-(2-hydroxypropyl)methacrylamide)HPMA-DOX conjugate (already clinically tested).     

Interobserver variation in the interpretation of abdominal radiographs

A total of 140 sets of abdominal radiographs were reviewed independently by four qualified diagnostic radiologists. The degree of interobserver agreement was determined by calculating kappa values for 19 commonly used radiographic signs and diagnoses. There was fair to excellent interobserver agreement for 11 signs and diagnoses and poor agreement for the remaining eight. The signs and diagnoses for which agreement is poor cannot be considered reliable and include particularly large bowel obstruction and nonspecific gas pattern.     

Polymer-bound derivatives of sarcolysin and their antitumour activity against mouse and human leukaemia in vitro

A series of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers containing different oligopeptide side-chains terminated in an alkylating anticancer agent-sarcolysin isopropyl ester (SL-OiP) and occasionally fucosylamine were synthetized. In the first step reactive polymeric precursors were prepared by radical precipitation copolymerization of HPMA with p-nitrophenyl esters of N-methacryloylated dipeptides (Gly-Phe or Gly-Leu). In the second step the former were aminolyzed with a dipeptide or amino acid derivatives of SL-OiP, thus forming tripeptide or tetrapeptide side-chains terminated in SL-OiP. Two of the polymers synthetized contained also fucosylamine as the terminal moiety, which was introduced as a targeting moiety, able to interact with fucose-specific membrane receptors of mouse leukaemia L 1210 cells. These polymers were synthetized by consecutive aminolysis of reactive polymeric precursors with fucosylamine and SL-OiP derivatives. To test the influence of the oligopeptide side-chain structure on the rate of drug release, the polymers synthetized were incubated with a mixture of lysosomal enzymes isolated from rat liver (tritosomes) and with cathepsin B. The relationship between the structure of polymer bound anticancer drugs and their biological activity was determined in vitro by their effect on the growth of mouse leukaemia L 1210 cells and human lymphoblastoid leukaemia (CCRF) cells. The results demonstrate the potential of these compounds as new types of targetable anticancer agents.