WY 18,251 (Tilomisole), an analog of levamisole: tolerability, and immune modulating effects in cancer patients.

Wy 18,251 (Tilomisole; Wyeth Laboratories, Philadelphia, PA, USA) is a benzimidazole that is structurally similar to the antihelminth levamisole that has recently been approved for the adjuvant treatment of colon cancer. In preclinical models, Tilomisole caused less agranulocytosis than levamisole, but retained immunomodulating capabilities. We examined the effects of Tilomisole administered to cancer patients in four different dose schedules: 60 mg/m2 orally (p.o.) weekly, and 60, 300, or 960 mg/m2 p.o. daily for 1 month. All patients were immunosuppressed when treatment was initiated as defined by standardized assays of phytohemagglutinin, concanavalin A, pokeweed mitogen, and mixed lymphocyte responses. Tilomisole was well tolerated with no significant side effects in 25 patients. There were no antitumor responses noted in this setting of metastatic cancer. There was no improvement in concanavalin A or pokeweed mitogen assays at any dose or schedule, but there was sustained improvement in mixed lymphocyte reaction and phytohemagglutinin assays at the 60 mg/m2 daily dose. This drug may have favorable biological response modifying effects in vivo and be a suitable alternative to levamisole in cancer treatment, especially if agranulocytosis is a significant problem associated with widespread use of levamisole.

Haemodynamic effects of atropine during halothane or isoflurane anaesthesia in infants and small children.

In this study, two-dimensional and pulsed Doppler echocardiography were used to measure cardiovascular changes before and after IV atropine in 31 infants and small children during halothane (n = 15) or isoflurane (n = 16) anaesthesia. Prior to induction of anaesthesia heart rate (HR), mean blood pressure (MBP), and two-dimensional echocardiographic dimensions of the left ventricle and pulmonary artery blood flow velocity were measured by pulsed Doppler echocardiography. Cardiovascular measurements were repeated while anaesthesia was maintained at 1.5 MAC halothane (n = 15) or isoflurane (n = 16). Atropine 0.02 mg.kg-1 IV was then administered and two minutes later, a third set of cardiovascular data was obtained. Heart rate decreased during halothane anaesthesia but did not change significantly during isoflurane anaesthesia. Mean blood pressure, cardiac output (CO) and stroke volume (SV) decreased similarly during 1.5 MAC halothane or isoflurane anaesthesia. Ejection fraction (EF) decreased and left ventricular end-diastolic volume (LVEDV) increased significantly in both groups, but decreases in EF (32 +/- 5 per cent vs 18 +/- 5 per cent) and increases in LVEDV (18 +/- 7 per cent vs 7 +/- 5 per cent) were significantly greater during halothane than during isoflurane anaesthesia. Following atropine, HR increased more in the patients maintained with halothane (31 +/- 6 per cent), than during isoflurane anaesthesia (18 +/- 5 per cent). Atropine increased CO in both groups of patients, but SV and EF remained unchanged. When compared with awake values, HR increased similarly and significantly (18 +/- 4 per cent) following atropine in both groups, and CO returned to control levels.(ABSTRACT TRUNCATED AT 250 WORDS)

New antineoplastic therapies and inherent risks: monoclonal antibodies, biologic response modifiers and interleukin-2.

The clinical use of Biological Response Modifiers (BRMs) in the diagnosis and treatment of cancer is rapidly changing the practice of oncology nursing. Recent key scientific advances have allowed production of unique natural agents useful in oncology as well as other diseases. An understanding of basic immunology is essential to the nurse involved in experimental clinical trials using BRMs. Interferons, Interleukins and Monoclonal Antibodies as well as other BRMs, all have biological/immunological interactions that must be understood. Nursing implications, I.V. techniques, and risk management as well as the scope of institutional interactions related to clinical trials with BRMs are described.

Pharmacokinetics of two per cent rectal methohexitone in children.

Plasma methohexitone concentrations were determined in 60 children, aged one to six years, following administration of 15 mg.kg-1, 20 mg.kg-1, 25 mg.kg-1 or 30 mg.kg-1 two per cent rectal methohexitone. Time to the onset of sleep was determined by a blinded observer and venous blood samples obtained 15, 30, 45 and 120 minutes following drug administration. Fifty of 60 children were asleep within 15 minutes. Nine of the ten children that did not fall asleep were sedate and could be separated easily from their parents to undergo inhalational induction of anesthesia. Time to the onset of sleep was inversely related to the dose of rectal methohexitone administered. Sleep was achieved more reliably following the use of 25 to 30 mg.kg-1 rectal methohexitone. In addition, plasma methohexitone concentrations following 30 mg.kg-1 rectal methohexitone were significantly higher for up to 120 minutes following drug administration than the plasma concentrations achieved after 15 mg.kg-1 or 20 mg.kg-1 methohexitone. There was no difference in the incidence of complications. The authors recommend that clinical circumstances be carefully considered and the dose of rectal methohexitone administered be individualized to meet the specific anaesthetic requirements of each child.

Etomidate anesthesia inhibits the cortisol response to surgical stress.

Plasma cortisol was measured in 18 patients undergoing gynecological procedures under etomidate or methohexital and nitrous oxide anesthesia. Plasma ACTH was also measured in three patients in each group. The mean plasma cortisol concentration before anesthesia was comparable in both groups. Plasma cortisol increased in patients anesthetized with methohexital, while none of the patients anesthetized with etomidate had an increase in plasma cortisol. The increase in plasma ACTH was equivalent in the two groups. Therefore, etomidate is a potent inhibitor of the adrenal response to surgery. The absence of clinical consequences associated with the blunted response suggests that a major increase in adrenal hormone production may not be necessary during surgery.

Radioimmunodetection of melanoma utilizing In-111 96.5 monoclonal antibody: a preliminary report.

The murine 96.5 monoclonal antimelanoma antibody (MoAb) was labeled with In-111, and 1-20 mg were administered to 21 patients who had proved or suspected melanoma metastases. One patient was studied twice. In four patients, unlabeled 96.5 MoAb was administered prior to the radiopharmaceutical. All of the patients tolerated the procedure without toxicity regardless of the mass of MoAb administered. The scans were interpreted by two observers, one with full knowledge, the other with no knowledge of the cases. Increasing the MoAb mass or preinfusing unlabeled MoAb prior to the administration of In-111 MoAb resulted in a prolongation of the serum half time, and appeared to improve tumor detection. Lesions were best seen at 72 hours after infusion or later. In all patients who had metastatic disease, at least one tumor site was apparent. Fifty-six per cent of known lesions 1.5 cm or greater in size were detected by the physician who had knowledge of the cases when data from all doses were considered. There were eight lesions detected that were not suspected in the workup of the patient. When these are included, the detection rate rises to 61%. Forty-nine per cent were detected by the other physician. Subtraction techniques were not employed. Lesions were often better seen with single photon emission computed tomography than with planar imaging techniques. The 96.5 In-111 MoAb appears to have utility for the detection of metastatic melanoma. Further clinical evaluation of 96.5 In-111 MoAb is warranted.

Therapy of chronic lymphocytic leukemia and cutaneous T-cell lymphoma with T101 monoclonal antibody.

The findings accompanying the administration of 50 intravenous courses of monoclonal antibody to human T-cell (T101) in eight patients, four with chronic lymphocytic leukemia and four with cutaneous T-cell lymphoma are reported. Infusion rates of 0.7 to 1 mg/min were associated with unacceptable toxicity in the presence of circulating target cells, but slower rates were well-tolerated. Immunofluorescence techniques confirmed that circulating cells did bind the antibody in vivo and were subsequently removed from the circulation. Modulation of the antigen on target cells in the bone marrow and skin has important implications for the schedule of administration of such antibodies, and points out the possible limitation of effector cell-mediated cytotoxicity at the tissue level. Production of anti-mouse antibodies resulted in neutralization of therapy in two patients with cutaneous T-cell lymphoma, and suggests that whether such an anti-mouse response is produced may be secondary to the underlying immune status of the patient or the amount of mouse protein to which immunocompetent cells are exposed. The relative specificity and efficacy of monoclonal antibody therapy is encouraging, but the limited clinical benefit and problems of modulation and anti-mouse antibody production underscore the need for continued research into passive therapy and suggest that cytotoxic conjugates may be of more clinical value.