The macromolecular neutron diffractometer MaNDi is currently under construction at the first target station of the Spallation Neutron Source at Oak Ridge National Laboratory. This instrument will collect neutron diffraction data from small single crystals (0.1–1 mm3) with lattice constants between 100 and 300 Å, as well as data from less well ordered systems such as fibers. A focusing neutron guide has been designed to filter the high‐energy neutron component of the spectrum and to provide a narrow beam with a wide spectral window and angular divergence almost insensitive to neutron wavelength. The system includes a final interchangeable section of neutron guide and two slits, which enable tuning of the horizontal and vertical beam divergence between 0.12 and 0.80° (full width at half‐maximum) at the sample position. This allows the trading of intensity for resolution, depending on the scientific requirements. Efforts to enhance and develop suitable high‐resolution neutron detectors at an affordable price are also discussed. Finally, the parameters of the neutron guide and detectors were used to simulate diffraction from a large unit cell.

We commenced a study in September 1981 to investigate the role of high-dose combination chemotherapy in the management of patients with non-Hodgkin's lymphomas who had failed conventional therapy. Fifty patients with diffuse intermediate- and high-grade non-Hodgkin's lymphomas were treated with high-dose combination chemotherapy with autologous bone marrow rescue (ABMT) and have a minimum follow-up of 1 year. Twenty patients had disease that was still responsive to conventional-dose chemotherapy, 15 had achieved a partial response (PR) to first-line therapy, and five were showing PR to salvage therapy after relapse. Twelve of these patients (60%) achieved complete remission (CR) (two following boost radiotherapy) and three patients have nonprogressive masses on computed tomographic (CT) scan as the only abnormality. None of these patients died during the procedure. Twenty-nine patients had disease not responsive to chemotherapy at conventional dosages: 19 had no response to first-line therapy and 10 showed no response to salvage therapy given after relapse. Only three of these patients achieved CR, all of short duration only. Only two patients in this group remain alive more than 2 years after the procedure and both have nonprogressive abnormalities on CT scan. Nine patients (31%) died of sepsis during the procedure. In those patients with disease not responsive to conventional-dose therapy, dose escalation is associated with a high procedure-related mortality and a low response rate. In those patients who still have chemotherapy-responsive disease the response rate is high and mortality is low.(ABSTRACT TRUNCATED AT 250 WORDS)

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High dose chemotherapy and autologous bone marrow transplantation (ABMT) is an effective form of salvage therapy in patients with relapsed or resistant Hodgkin's disease. Patients with large tumour masses at the time of ABMT have a poorer prognosis and we have therefore administered intermediate dose BCNU, etoposide, cytarabine and melphalan (mini-BEAM) prior to high dose therapy with the same agents (BEAM) and ABMT in such patients. In addition we have used the same strategy in patients with bone marrow infiltration at the time of relapse in an attempt to clear the bone marrow for transplant. A total of 23 patients received mini-BEAM and 21 proceeded to BEAM and ABMT. Platelet engraftment was delayed compared to BEAM recipients who had not received mini-BEAM (P = 0.008) but there was only one procedure related death. Responses to BEAM and ABMT were not predicted by the response to mini-BEAM indicating a dose response effect at the upper end of the dose intensity spectrum. At 2 years, the overall survival and progression free survival are 61% and 46% respectively for this group of Hodgkin's patients with extremely poor prognosis.

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