Tuning Amorphous Selenium Composition with Tellurium to Improve Quantum Efficiency at Long Wavelengths and High Applied Fields

Amorphous selenium (a-Se) is a large-area compatible photoconductor that has received significant attention toward the development of UV and X-ray detectors for a wide range of applications in medical imaging, life science, high-energy physics, and nuclear radiation detection. A subset of applications require detection of photons with spectral coverage from UV to infrared wavelengths. In this work, we present a systematic study utilizing density functional theory simulations and experimental studies to investigate optical and electrical properties of a-Se alloyed with tellurium (Te). We report hole and electron mobilities and conversion efficiencies for a-Se_1-xTe_x (x = 0, 0.03, 0.05, 0.08) devices as a function of applied field, along with band gaps and comparisons to previous studies. For the first time, these values are reported at high electric field (>10 V/μm), demonstrating recovery of quantum efficiency in Se-Te alloys. A comparison to the Onsager model for a-Se demonstrates the strong field dependence in the thermalization length and expands on the role of defect states in device performance.

Using Machine Learning Potentials to Explore Interdiffusion at Metal-Chalcogenide Interfaces

Chalcogenide alloys are key materials for selector and memory elements used in next-generation nonvolatile memory cells. However, the high electric fields and Joule heating experienced during operation can promote interdiffusion at the interfaces that degrade device performance over time. A clear atomic scale understanding of how chalcogenide alloys interact with electrodes could aid in identifying ways to improve long-term device endurance. In this work, we develop a robust set of moment tensor potentials (MTPs) to examine interactions between Ge-Se alloys and Ti electrodes. Previous works have shown evidence of strong interactions between Ti and chalcogenide alloys. This system offers an important first test in the use of ML empirical potentials to understand the role of interfaces in endurance in memory elements and broader nanoscale devices. The empirical potentials are constructed using an active learning moment tensor potential framework that leverages a broad data set of first-principles calculations for Ti, Ge, and Se compounds. Long-term simulations (>1 ns) show significant interdiffusion at the Ti|Ge-Se interface with Ti and Se both actively moving across the original interface. The strong chemical affinity of Ti and Se leads to a well-defined Ti-Se region and a severely Se-depleted central Ge-Se region with unfavorable selector characteristics. The evolution of the Ti-Se layer can be described using a self-limited growth model. By comparing effective Ti-Se diffusion constants for simulations at different temperatures, we find a low activation energy of 0.1 eV for Ti-Se layer interdiffusion.

New thinking for filth fly control: residual, non-chemical wall spray from volcanic glass

Filth flies are of medical and veterinary importance because of the transfer of disease organisms to animals and humans. The traditional control methods include the use of chemical insecticides. A novel mechanical insecticide made from volcanic glass and originally developed to control mosquitoes (Imergard™ WP; ImG) was investigated for control of adult grey flesh flies, Sarcophaga bullata (Parker), secondary screwworms, Cochliomyia macellaria (F.), and house flies, Musca domestica L. In a modified WHO cone test device, the time to 50% mortality (LT₅₀ ) when applied at 5 g/m² (tested at 30 °C and 50% relative humidity (rH)) was 7.1, 4.3 and 3.2 h, respectively. When knockdown was included, the LT₅₀ s were 5.5, 1.5 and 2.8 h, respectively. Application rates of 1.25 and greater g/m² had the shortest LT₅₀ s. The time to the LT₅₀ increased for M. domestica as rH increased, but ImG was still active at the highest rH tested of 70%. Scanning electron micrographs showed ImG was present on all body parts, unlike that for mosquitoes where it was found mostly on the lower legs. These first studies on the use of Imergard WP against flies suggest this could be an alternative method for filth fly control.

Evaluating Ovonic Threshold Switching Materials with Topological Constraint Theory

The physical properties of ovonic threshold switching (OTS) materials are of great interest due to the use of OTS materials as selectors in cross-point array nonvolatile memory systems. Here, we show that the topological constraint theory (TCT) of chalcogenide glasses provides a robust framework to describe the physical properties of sputtered thin film OTS materials and electronic devices. Using the mean coordination number (MCN) of an OTS alloy as a comparative metric, we show that changes in data trends from several measurements are signatures of the transition from a floppy to a rigid glass network as described by TCT. This approach provides a means to optimize OTS selector materials for device applications using film-level measurements.

Tuning network topology and vibrational mode localization to achieve ultralow thermal conductivity in amorphous chalcogenides

Amorphous chalcogenide alloys are key materials for data storage and energy scavenging applications due to their large non-linearities in optical and electrical properties as well as low vibrational thermal conductivities. Here, we report on a mechanism to suppress the thermal transport in a representative amorphous chalcogenide system, silicon telluride (SiTe), by nearly an order of magnitude via systematically tailoring the cross-linking network among the atoms. As such, we experimentally demonstrate that in fully dense amorphous SiTe the thermal conductivity can be reduced to as low as 0.10 ± 0.01 W m-1 K-1 for high tellurium content with a density nearly twice that of amorphous silicon. Using ab-initio simulations integrated with lattice dynamics, we attribute the ultralow thermal conductivity of SiTe to the suppressed contribution of extended modes of vibration, namely propagons and diffusons. This leads to a large shift in the mobility edge - a factor of five - towards lower frequency and localization of nearly 42% of the modes. This localization is the result of reductions in coordination number and a transition from over-constrained to under-constrained atomic network.

Interface controlled thermal resistances of ultra-thin chalcogenide-based phase change memory devices

Phase change memory (PCM) is a rapidly growing technology that not only offers advancements in storage-class memories but also enables in-memory data processing to overcome the von Neumann bottleneck. In PCMs, data storage is driven by thermal excitation. However, there is limited research regarding PCM thermal properties at length scales close to the memory cell dimensions. Our work presents a new paradigm to manage thermal transport in memory cells by manipulating the interfacial thermal resistance between the phase change unit and the electrodes without incorporating additional insulating layers. Experimental measurements show a substantial change in interfacial thermal resistance as GST transitions from cubic to hexagonal crystal structure, resulting in a factor of 4 reduction in the effective thermal conductivity. Simulations reveal that interfacial resistance between PCM and its adjacent layer can reduce the reset current for 20 and 120 nm diameter devices by up to ~ 40% and ~ 50%, respectively. These thermal insights present a new opportunity to reduce power and operating currents in PCMs.

Evaluation of subcutaneous rituximab administration on Canadian systemic therapy suites

Background

Non-Hodgkin lymphoma (nhl) is the most common hematologic malignancy. Diffuse large B-cell lymphoma (dlbcl) and follicular lymphoma (fl) constitute 55% of new nhl cases and are initially treated with rituximab-based chemoimmunotherapy. Relative to intravenous (IV) rituximab, a subcutaneous (sc) formulation approved in 2016 has comparable pharmacokinetics, efficacy, and safety, and a greatly reduced administration time; it is also preferred by patients. The objective of the present study was to estimate the effect (on systemic therapy suite time and on the costs of drug acquisition and administration) of implementing sc rituximab in the initial chemoimmunotherapy for fl and dlbcl over 3 years in the Canadian market.

Methods

An Excel (Microsoft Corporation, Redmond, WA, U.S.A.)-based model was created with a population size based on epidemiologic data and current rituximab use, duration of use considering initial therapy, time savings for sc rituximab administration from published studies, costs from standard Canadian sources, and assumed uptake in implementing provinces of 65%, 75%, and 80% over 3 years. Key parameters and sensitivity analysis values were validated by clinical experts located in various Canadian jurisdictions. Costs are reported in 2017 Canadian dollars from the perspective of the health care system.

Results

More than 3 years after implementation of sc rituximab, we estimated that 5762 Canadians would be receiving sc rituximab, resulting in savings of 128,715 hours in systemic therapy suite time and approximately $40 million in drug and administration costs. Sensitivity analyses suggest that the model is most sensitive to sc market uptake, number of induction therapy cycles, and eligible patients.

Conclusions

Subcutaneous administration of rituximab can significantly reduce systemic therapy suite time and achieve substantial savings in drug and administration costs.

Two-Dimensional Intrinsic Half-Metals With Large Spin Gaps

Through a systematic search of all layered bulk compounds combined with density functional calculations employing hybrid exchange-correlation functionals, we predict a family of three magnetic two-dimensional (2D) materials with half-metallic band structures. The 2D materials, FeCl₂, FeBr₂, and FeI₂, are all sufficiently stable to be exfoliated from bulk layered compounds. The Fe²⁺ ions in these materials are in a high-spin octahedral d⁶ configuration leading to a large magnetic moment of 4 μ_B. Calculations of the magnetic anisotropy show an easy-plane for the magnetic moment. A classical XY model with nearest neighbor coupling estimates critical temperatures, T_c, for the Berezinskii-Kosterlitz-Thouless transition ranging from 122 K for FeI₂ to 210 K for FeBr₂. The quantum confinement of these 2D materials results in unusually large spin gaps, ranging from 4.0 eV for FeI₂ to 6.4 eV for FeCl₂, which should defend against spin current leakage even at small device length scales. Their purely spin-polarized currents and dispersive interlayer interactions should make these materials useful for 2D spin valves and other spintronic applications.

Using Dopants to Tune Oxygen Vacancy Formation in Transition Metal Oxide Resistive Memory

Introducing dopants is an important way to tailor and improve electronic properties of transition metal oxides used as high-k dielectric thin films and resistance switching layers in leading memory technologies, such as dynamic and resistive random access memory (ReRAM). Ta₂O₅ has recently received increasing interest because Ta₂O₅-based ReRAM demonstrates high switching speed, long endurance, and low operating voltage. However, advances in optimizing device characteristics with dopants have been hindered by limited and contradictory experiments in this field. We report on a systematic study on how various metal dopants affect oxygen vacancy formation in crystalline and amorphous Ta₂O₅ from first principles. We find that isoelectronic dopants and weak n-type dopants have little impact on neutral vacancy formation energy and that p-type dopants can lower the formation energy significantly by introducing holes into the system. In contrast, n-type dopants have a deleterious effect and actually increase the formation energy for charged oxygen vacancies. Given the similar doping trend reported for other binary transition metal oxides, this doping trend should be universally valid for typical binary transition metal oxides. Based on this guideline, we propose that p-type dopants (Al, Hf, Zr, and Ti) can lower the forming/set voltage and improve retention properties of Ta₂O₅ ReRAM.

The two-minute walking test: a sensitive index of mobility in the rehabilitation of elderly patients

The usefulness of a timed walking test adapted for use as an index of mobility in elderly subjects undergoing rehabilitation was assessed. The 95% confidence interval for repeatability in 27 subjects was found to be -27% to +38%. The test was able to detect a significant improvement ( p < 0.01) in a group of subjects undergoing active rehabilitation, whereas no improvement was detected by a conventional rating scale. The two-minute walking test is a simple and sensitive index of mobility in the elderly.

Prospective Audit of the Management of Head Injuries in a Small District General Hospital

Abstract Background and Aims: In September 2000 the Scottish Intercollegiate Guidelines Network published their recommendations on the optimal early management of head injured patients. Early identification of significant intracranial pathology through CT scanning is central to these guidelines. At our small DGH, head injured patients are received and managed by general surgeons with no specific training in head trauma. In addition, there is as yet no arrangement in place for urgent CT scanning. Because of these factors, an audit was conducted to determine the extent to which we were able to comply with these guidelines. Methods.: A 2 month prospective audit of the management of head injured patients was carried out collecting data on patient demographics, clinical condition on admission, clinical course, radiological investigations (and difficulty in arranging them) and outcome. Results: Over the 2 month period 52 consecutive patients were studied. Fifteen patients met criteria for CT scanning, of which 9 were ultimately scanned. Tellingly, only one of the fifteen received their scan within the recommended four hour period. In this series, no patient had an adverse clinical event related to delay in scanning. Conclusion: Any hospital admitting head injured patients should have 24 hour access to CT scanning facilities. If such an arrangement is not in place then patients with head injuries should not be admitted to that hospital.

Twisting phonons in complex crystals with quasi-one-dimensional substructures

A variety of crystals contain quasi-one-dimensional substructures, which yield distinctive electronic, spintronic, optical and thermoelectric properties. There is a lack of understanding of the lattice dynamics that influences the properties of such complex crystals. Here we employ inelastic neutron scatting measurements and density functional theory calculations to show that numerous low-energy optical vibrational modes exist in higher manganese silicides, an example of such crystals. These optical modes, including unusually low-frequency twisting motions of the Si ladders inside the Mn chimneys, provide a large phase space for scattering acoustic phonons. A hybrid phonon and diffuson model is proposed to explain the low and anisotropic thermal conductivity of higher manganese silicides and to evaluate nanostructuring as an approach to further suppress the thermal conductivity and enhance the thermoelectric energy conversion efficiency. This discovery offers new insights into the structure-property relationships of a broad class of materials with quasi-one-dimensional substructures for various applications.

Polar effects on the thermal conductivity of cubic boron nitride under pressure

We report the lattice thermal conductivity (κ) of cubic boron nitride (c-BN) under pressure calculated using density functional theory. Pressure was used to manipulate the c-BN phonon dispersion and study its effect on thermal conductivity. These results were compared to c-BN's mass-equivalent, nonpolar counterpart, diamond, in order to isolate the effect of polar bonds on thermal conductivity. Unlike diamond, the variation of κ at room temperature (κ(RT)) with applied pressure in c-BN is nonlinear in the low-pressure regime followed by a transition to a linear regime with a distinct change in the slope at P>114  GPa. We find that the change in κ with pressure cannot be described with power law expressions commonly used for Earth mantle materials. The nonlinearity in the low-pressure regime can be related to the nonlinear change in LO-TO gap, group velocities, and specific heat with increasing pressure. In addition, we find that, although optical branch contributions to thermal conductivity are small (∼2% at RT), the rise in κ(RT) for P>114  GPa is due to (1) the decoupling of the longitudinal acoustic branch from the optical branches and (2) depopulation of the optical branches. These lead to a sharp reduction in acoustic-acoustic-optic (a-a-o) scattering and a discrete change in the acoustic phonon mean free paths. This study illustrates the importance of optical branches and their interactions with acoustic branches in determining the total thermal conductivity of polar materials. This finding is also relevant for current research in geologic minerals under pressure and the design of thermoelectrics.

Direct measurements of surface scattering in Si nanosheets using a microscale phonon spectrometer: implications for Casimir-limit predicted by Ziman theory

Thermal transport in nanostructures is strongly affected by phonon-surface interactions, which are expected to depend on the phonon's wavelength and the surface roughness. Here we fabricate silicon nanosheets, measure their surface roughness (∼ 1 nm) using atomic force microscopy (AFM), and assess the phonon scattering rate in the sheets with a novel technique: a microscale phonon spectrometer. The spectrometer employs superconducting tunnel junctions (STJs) to produce and detect controllable nonthermal distributions of phonons from ∼ 90 to ∼ 870 GHz. This technique offers spectral resolution nearly 10 times better than a thermal conductance measurement. We compare measured phonon transmission rates to rates predicted by a Monte Carlo model of phonon trajectories, assuming that these trajectories are dominated by phonon-surface interactions and using the Ziman theory to predict phonon-surface scattering rates based on surface topology. Whereas theory predicts a diffuse surface scattering probability of less than 40%, our measurements are consistent with a 100% probability. Our nanosheets therefore exhibit the so-called "Casimir limit" at a much lower frequency than expected if the phonon scattering rates follow the Ziman theory for a 1 nm surface roughness. Such a result holds implications for thermal management in nanoscale electronics and the design of nanostructured thermoelectrics.

Successful replantation of a finger in an 8-month old child

A successful replantation of an index fingertip in an 8-month old girl is reported. A literature review of replants in very young children suggests this is one of the youngest patients ever to undergo digital replantation and possibly the youngest finger replant performed.

IL15 levels on day 7 after hematopoietic cell transplantation predict chronic GVHD

Chronic GVHD (cGVHD) is an important complication of allogeneic hematopoietic cell transplantation (HCT). As preemptive therapy might be efficacious if administered early post transplant, we set out to determine whether cGVHD can be predicted from the serum level of a biomarker on day 7 or 28. In a discovery cohort of 153 HCT recipients conditioned with BU, fludarabine and rabbit antithymocyte globulin (ATG), we determined serum levels of B-cell-activating factor, vascular endothelial growth factor, soluble TNF-α receptor 1, soluble IL2 receptor α, IL5, IL6, IL7, IL15, γ-glutamyl transpeptidase, cholinesterase, total protein, urea and ATG. Patients with low levels of IL15 (<30.6 ng/L) on day 7 had 2.7-fold higher likelihood of developing significant cGVHD (needing systemic immunosuppressive therapy) than patients with higher IL15 levels (P<0.001). This was validated in a validation cohort of 105 similarly-treated patients; those with low IL15 levels had 3.7-fold higher likelihood of developing significant cGVHD (P=0.001). Low IL15 was not associated with relapse; it trended to be associated with acute GVHD and was associated with low infection rates. In conclusion, low IL15 levels on day 7 are predictive of cGVHD, and thus could be useful in guiding preemptive therapy.

Band gap and electronic structure of an epitaxial, semiconducting Cr0.80Al0.20 thin film

Cr(1-x)Al(x) exhibits semiconducting behavior for x = 0.15-0.26. This Letter uses hard x-ray photoemission spectroscopy and density functional theory to further understand the semiconducting behavior. Photoemission measurements of an epitaxial Cr(0.80)Al(0.20) thin film show several features in the valence band region, including a gap at the Fermi energy (E(F)) for which the valence band edge is 95 ± 14 meV below E(F). Theory agrees well with the valence band measurements, and shows an incomplete gap at E(F) due to the hole band at M shifting almost below E(F).

New type of magnetic tunnel junction based on spin filtering through a reduced symmetry oxide: FeCo|Mg3B2O6|FeCo

Magnetic tunnel junctions with high-tunneling magnetoresistance values such as Fe|MgO|Fe capitalize on spin filtering in the oxide region based on the band symmetry of incident electrons. However, these structures rely on magnetic leads and oxide regions of the same cubic symmetry class. A new magnetic tunnel junction (FeCo|Mg(3)B(2)O(6)|FeCo) is presented that uses a reduced symmetry oxide region (orthorhombic) to provide spin filtering between the two cubic magnetic leads. Complex band structure analysis of Mg(3)B(2)O(6) based on density functional calculations shows that significant spin filtering could occur in this system. This new type of magnetic tunnel junction may have been fabricated already and can explain recent experimental studies of rf-sputtered FeCoB|MgO|FeCoB junctions where there is significant B diffusion into the MgO region.

Atomic and electronic structure of graphene-oxide

We elucidate the atomic and electronic structure of graphene oxide (GO) using annular dark field imaging of single and multilayer sheets and electron energy loss spectroscopy for measuring the fine structure of C and O K-edges in a scanning transmission electron microscope. Partial density of states and electronic plasma excitations are also measured for these GO sheets showing unusual pi* + sigma* excitation at 19 eV. The results of this detailed analysis reveal that the GO is rough with an average surface roughness of 0.6 nm and the structure is predominantly amorphous due to distortions from sp3 C-O bonds. Around 40% sp3 bonding was found to be present in these sheets with measured O/C ratio of 1:5. These sp2 to sp3 bond modifications due to oxidation are also supported by ab initio calculations

First-principles calculation of the isotope effect on boron nitride nanotube thermal conductivity

Isotopic composition can dramatically affect thermal transport in nanoscale heat conduits such as nanotubes and nanowires. A 50% increase in thermal conductivity for isotopically pure boron ((11)B) nitride nanotubes was recently measured, but the reason for this enhancement remains unclear. To address this issue, we examine thermal transport through boron nitride nanotubes using an atomistic Green's function transport formalism coupled with phonon properties calculated from density functional theory. We develop an independent scatterer model for (10)B defects to account for phonon isotope scattering found in natural boron nitride nanotubes. Phonon scattering from (10)B dramatically reduces phonon transport at higher frequencies and our model accounts for the experimentally observed enhancement in thermal conductivity.

Phonon transport in isotope-disordered carbon and boron-nitride nanotubes: is localization observable?

We present an ab initio study which identifies dominant effects leading to thermal conductivity reductions in carbon and boron-nitride nanotubes with isotope disorder. Our analysis reveals that, contrary to previous speculations, localization effects cannot be observed in the thermal conductivity measurements. Observable reduction of the thermal conductivity is mostly due to diffusive scattering. Multiple scattering induced interference effects were found to be prominent for isotope concentrations > or approximately 10%; otherwise, the thermal conduction is mainly determined by independent scattering contributions of single isotopes. We give explicit predictions of the effect of isotope disorder on nanotube thermal conductivity that can be directly compared with experiments.

Viral purging of haematological autografts: should we sneeze on the graft?

High-dose cytotoxic chemotherapy followed by autologous haematopoietic stem cell transplantation (ASCT) is extensively used for the treatment of many haematopoietic, as well as several epithelial cancers. Disease relapse may be the result of tumour contamination within autograft as evidenced by gene marking studies. The multiple purging strategies that have been described to date have not proven effective in most ASCT settings. This review addresses the possibility of using oncolytic viruses as a novel purging strategy. DNA viruses such as genetically engineered adenoviral vectors have widely been used to deliver either a prodrug-activating enzyme or express wild-type p53 selectively in tumour cells in ex vivo purging protocols. In addition, conditionally replicating adenoviruses that selectively replicate in tumour cells and herpes simplex virus type 1 are other DNA viruses that have been tested as ex vivo purging agents under laboratory conditions. Vesicular stomatitis virus (VSV) and reovirus are naturally occurring RNA viruses that appear to hold promise as purging agents under ex vivo and in vivo settings. Preclinical data demonstrate reovirus's purging potential against breast, monocytic and myeloma cell lines as well as patient-derived tumours of diffuse large B-cell lymphoma, chronic lymphocytic leukaemia, Waldenstrom macroglobulinemia and small lymphocytic lymphoma. In addition, VSV has shown effective killing of leukaemic cell lines and multiple myeloma patient specimens. Given the increasing interest in the utilization of viruses as purging agents, the following review provides a timely summary of the potential and the challenges of oncolytic viruses as purging modalities during ASCT.

Complications of 278 consecutive abdominoplasties

The case notes of 278 consecutive patients who underwent abdominoplasty, during a five-year period, in one institution under the care of four surgeons were reviewed. Patient details, early and late complications and revision procedures were noted. Seventy-five percent of patients had a 'full' abdominoplasty with undermining to costal cartilage and repositioning of the umbilicus and 23% had 'mini abdominoplasties', 2% were revision operations. Eighteen percent of patients suffered from early complications the most common of which were seroma (5%), haematoma (3%), infection (3%), skin or fat necrosis (2.5%) and delayed healing (2%). Twenty-five percent of patients had late complications which were often relatively minor. These included 'dog ears' (12%), localised fatty excess (10%) and unsatisfactory scars (8%). Twenty-four percent of patients underwent revision surgery. Most commonly further liposuction (12%), dog ear revision (10%) and scar revision (5%). Analysis failed to reveal significant risk factors. Despite an apparently high complication and revision rate the subjective impression is of a satisfied patient cohort.

Properties of short channel ballistic carbon nanotube transistors with ohmic contacts

We present self-consistent, non-equilibrium Green's function calculations of the characteristics of short channel carbon nanotube transistors, focusing on the regime of ballistic transport with ohmic contacts. We first establish that the band line-up at the contacts is renormalized by charge transfer, leading to Schottky contacts for small diameter nanotubes and ohmic contacts for large diameter nanotubes, in agreement with recent experiments. For short channel ohmic contact devices, source-drain tunnelling and drain-induced barrier lowering significantly impact the current-voltage characteristics. Furthermore, the ON state conductance shows a temperature dependence, even in the absence of phonon scattering or Schottky barriers. This last result also agrees with recently reported experimental measurements.

Overnight storage of autologous stem cell apheresis products before cryopreservation does not adversely impact early or long-term engraftment following transplantation

To reduce costs and avoid inconvenient overtime work, our institution changed policy in September 2000 so that autologous stem cell apheresis products were stored overnight before cryopreservation rather than immediately processed. This retrospective review was conducted to evaluate the possible impact of this policy change on hematopoietic engraftment following autologous stem cell transplantation (ASCT). In total, 229 consecutive lymphoma patients who underwent a single, unpurged ASCT in Calgary between January 1995 and November 2003 were evaluated. Of these patients, 131 patients' autografts underwent immediate processing and cryopreservation before September 2000, and 98 patients' autografts underwent next-day cryopreservation after overnight storage following this date. Results of univariate and multivariate analyses demonstrated no adverse effect of overnight storage before cryopreservation on the number of days to initial engraftment of platelets or neutrophils, on the proportion of patients with low blood counts 6 months post-ASCT, or on lymphoma relapse rates or overall survival post-ASCT. These data suggest that overnight storage of the autograft before cryopreservation does not adversely affect graft viability or influence long-term disease status, and support the continued use of overnight storage of stem cells before cryopreservation as a convenient, cost reduction measure.

The unexpected sites of melanoma regional recurrences

Sentinel node biopsy is a means of identifying nodal involvement in melanoma and lymphoscintigraphy identifies unpredictable sites of melanoma sentinel nodes in up to 25% of cases. Whilst there is a dearth of recent publications in this area, it nevertheless remains an interesting observation that unpredictable sites of sentinel nodes are so common as to be accepted as normal. This study was performed to determine if this high rate of unpredictable lymphatic drainage was reflected in clinical practice, where therapeutic lymph node dissections were performed for pathologically confirmed regional disease.

METHODS

Patients undergoing regional lymph node dissections for histologically proven malignant melanoma were identified from a computer database. Patient details were analysed from case records.

RESULTS

Two hundred and forty-three case records were examined and 237 were suitable for analysis. The site of the primary was the head and neck in 50 (21%), trunk in 73 (31%), upper limb in 27 (11%) and lower limb in 87 (37%). In 15 cases (6%), the first site of regional disease was unpredictable. In these 15 cases, the site of the primary was the head and neck in two, trunk in 11, upper limb in one and lower limb in one. In 37 cases (16%), a subsequent site of nodal recurrence was unpredictable. Clinicians should be aware that patients with melanomas, particularly of the trunk, especially those in whom a therapeutic nodal dissection has been performed, may have nodal disease at unpredictable sites. However, unexpected sites of regional disease are not as common as sentinel node biopsy would suggest. Guidelines for lymph node examination in cutaneous melanoma are suggested based on these findings.

Negative spin polarization and large tunneling magnetoresistance in epitaxial Co/SrTiO(3)/Co magnetic tunnel junctions

We perform an ab initio study of spin-polarized tunneling in epitaxial Co/SrTiO(3)/Co magnetic tunnel junctions with bcc Co(001) electrodes. We predict a large tunneling magnetoresistance in these junctions, originating from a mismatch in the majority- and minority-spin bands both in bulk bcc Co and at the Co/SrTiO(3)/Co interface. The intricate complex band structure of SrTiO(3) enables efficient tunneling of the minority d electrons which causes the spin polarization of the Co/SrTiO(3)/Co interface to be negative in agreement with experimental data. Our results indicate that epitaxial Co/SrTiO(3)/Co magnetic tunnel junctions with bcc Co(001) electrodes are a viable alternative for device applications.

High-dose mitoxantrone–vinblastine–cyclophosphamide and autologous stem cell transplantation for stage III breast cancer: final results of a prospective multicentre study

BACKGROUND

Stage III breast cancer patients continue to suffer high relapse and death rates despite standard chemotherapy regimens. High-dose alkylator chemotherapy does not further improve outcome. This phase II study evaluated a novel high-dose chemotherapy regimen which combined active breast cancer agents with differing mechanisms of action.

PATIENTS AND METHODS

Eligibility included at least seven involved axillary nodes (AxLNs) for tumours <5 cm, at least four AxLNs for tumours >5 cm or locally advanced breast cancer (LABC). Patients received four cycles of fluorouracil-adriamycin-cyclophosphamide (FAC) followed by one cycle of mitoxantrone 63 mg/m(2)-vinblastine 12.5 mg/m(2)-cyclophosphamide 6 g/m(2) (MVC) with autologous blood stem cell transplantation (ASCT).

RESULTS

Between April 1995 and December 1998, 92 patients aged 21-65 years (median 45 years) were enrolled, of whom 25 were treated preoperatively for LABC and 67 were treated postoperatively. Although there was no early treatment-related mortality, one late death occurred from secondary acute myeloid leukaemia. The 7-year event-free and overall survival rates were 53% (95% confidence interval 42-64%) and 62% (95% CI 52-73%), respectively, with no significant difference between pre- and postoperative groups.

CONCLUSION

FAC followed by MVC-ASCT is feasible and reasonably well tolerated, but does not result in improved survival rates compared with other conventional or high-dose regimens for stage III breast cancer.

Biological purging of breast cancer cell lines using a replication-competent oncolytic virus in human stem cell autografts

Autologous hematological stem cell transplantation (ASCT) is used for the treatment of many hematological and several solid cancers. ASCT, however, has proven disappointing as a therapeutic strategy for breast cancer. Our group and others have previously shown that breast cancer micrometastases found in patients' apheresis products (APs) predict shorter progression-free and overall survival. The implications of this finding are twofold: (i) contaminating tumor cells (CTCs) in AP reflect a higher systemic disease burden and/or (ii) reinfused CTCs contribute to relapse/progressive disease. To date, purging strategies have been disappointing. We have previously demonstrated the oncolytic properties of reovirus in in vitro, in vivo and ex vivo systems. In the present study, we tested the hypothesis that reovirus purges CTCs in a breast cancer cell line purging model. Reovirus-infected human breast cancer cell lines (HTB 133, HTB 132, SKBR3 and MCF7) exhibited cell death within days. Admixtures of AP with cells from breast tumor cell lines, which were then exposed to reovirus, showed complete purging of CTCs (assessed via flow cytometry/tumor cell outgrowth analysis) without deleterious effect on CD34+ cells. Our results provide preclinical support for the ex vivo use of reovirus as a purging modality for breast cancer during ASCT.

Autologous transplantation for primary systemic AL amyloidosis is feasible outside a major amyloidosis referral centre: the Calgary BMT Program experience

Recent reports from large amyloidosis referral centers suggest that primary systemic AL amyloidosis patients treated with high-dose melphalan (HDM) and autologous stem cell transplantation (ASCT) survive longer than historical controls treated with less intensive chemotherapy, despite high transplant-related mortality (TRM) rates of >10%. A retrospective review was conducted to determine if the outcome of ASCT for AL amyloidosis at our institution was similar to that reported at major amyloidosis referral centers. Over a 7 year period, we treated a total of 15 AL amyloidosis patients with ASCT, including four with poor prognosis cardiac or multisystem involvement. No TRM was observed. Overall, 10 patients (67%) achieved a complete hematological response and four patients (27%) achieved a complete organ response. The 4-year event-free and overall survival rates were 60% (95% CI 32-89%) and 75% (95% CI 50-100%), respectively. One patient, who presented with cardiac failure and multiorgan involvement with colonic bleeding currently remains in complete remission 62 months post-ASCT. In conclusion, ASCT for primary AL amyloidosis can safely be performed at experienced transplant centers that are not associated with major amyloidosis referral centers, and is feasible for patients who have multisystem involvement, particularly for motivated patients with good performance status.

Energy conversion efficiency in nanotube optoelectronics

We present theoretical performance estimates for nanotube optoelectronic devices under bias. Current-voltage characteristics of illuminated nanotube p-n junctions are calculated using a self-consistent nonequilibrium Green's function approach. Energy conversion rates reaching tens of percent are predicted for incident photon energies near the band gap energy. In addition, the energy conversion rate increases as the diameter of the nanotube is reduced, even though the quantum efficiency shows little dependence on nanotube radius. These results indicate that the quantum efficiency is not a limiting factor for use of nanotubes in optoelectronics.

Photocurrents in nanotube junctions

Photocurrents in nanotube p-n junctions are calculated using a nonequilibrium Green function quantum transport formalism. The short-circuit photocurrent displays band-to-band transitions and photon-assisted tunneling, and has multiple sharp peaks in the infrared, visible, and ultraviolet. The operation of such devices in the nanoscale regime leads to unusual size effects, where the photocurrent scales linearly and oscillates with device length. The oscillations can be related to the density of states in the valence band, a factor that also determines the relative magnitude of the photoresponse for different bands.

High-dose thiotepa, busulfan, cyclophosphamide and ASCT without whole-brain radiotherapy for poor prognosis primary CNS lymphoma

Treatment of primary central nervous system lymphoma (PCNSL) with combined high-dose methotrexate (HD-MTX)-based chemotherapy and whole-brain radiotherapy (WBRT) is associated with severe neurotoxicity, but high relapse rates are associated with the use of either modality alone. In an attempt to improve upon these dismal results, we treated seven PCNSL patients with HD-MTX-based induction therapy followed by thiotepa, busulfan, cyclophosphamide (TBC), and autologous stem cell transplant (ASCT), without WBRT. Six of these patients had at least one of the following poor prognostic features: Karnofsky performance status (KPS) <or=50%, age >60 years, or relapsed disease. All but one patient tolerated the treatment well and experienced improvements in neurological function and overall performance status post-transplant. No treatment-induced neurotoxicity (dementia, ataxia, and incontinence) was observed although the follow-up is short. One early treatment-related death occurred in a patient with multiple comorbid medical conditions. The other six patients achieved a complete response (CR) after TBC and ASCT. Five patients are currently alive and relapse-free at 5, 8, 24, 36, and 42 months from diagnosis. One additional patient relapsed and died 33 months after diagnosis. Two of the seven patients received TBC/ASCT as the only treatment after disease progression following their initial chemotherapy and both remain relapse-free at the time of this report, 22 and 31 months post-TBC/ASCT. In conclusion, prolonged CR can be attained after chemotherapy-only treatment of poor prognosis PCNSL. Furthermore, this small series suggests that high-dose chemotherapy for PCNSL should include drugs that penetrate the CNS such as busulfan and thiotepa rather than standard lymphoma regimens such as BEAM.

Possible benefits of high-dose chemotherapy and autologous stem cell transplantation for adults with recurrent medulloblastoma

In an attempt to improve the dismal prognosis of adults with recurrent medulloblastoma, six patients were treated with aggressive salvage therapy including high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT). At relapse, all patients underwent surgical debulking followed by HDCT/ASCT and then radiotherapy when possible. The treatment plan included two cycles of HDCT/ASCT; first with cyclophosphamide, etoposide and carboplatin (CECb) and then 2 months later with cyclophosphamide and thiotepa (CT). Three of the six patients received the planned therapy. One patient experienced severe toxicity requiring life-sustaining therapy. This patient developed multi-organ dysfunction including multiple enhancing lesions in both cerebral hemispheres that slowly resolved over several months. Two other patients did not mobilize sufficient stem cells for two ASCT procedures. They received one ASCT conditioned with cyclophosphamide, thiotepa and carboplatin (CTCb). Three of six patients had a complete response (CR); the other three had a partial response (PR). Following the first ASCT, median duration of response was 13.5 months (range 9-29 months) and median survival was 21.5 months (range 12-42 months). There was no treatment-related mortality. We conclude that HDCT/ASCT with CECb-CT or CTCb is active against recurrent medulloblastoma in adults and may be associated with prolonged remissions. Multiple enhancing cerebral lesions on brain MRI early post-HDCT/ASCT may be a consequence of the treatment rather than metastatic disease.

Successful treatment of post-transplant lymphoproliferative disorder in autologous blood stem cell transplant recipients

We report three cases of post-transplant lymphoproliferative disorder (PTLD) in the context of autologous stem cell transplantation (ASCT) for multiple myeloma (MM) and non-Hodgkin's lymphoma. The first two cases received ASCT for MM, one with a CD34-selected autograft and the other with an unmanipulated autograft. Both these cases of PTLD achieved a complete response following treatment with IVIG, gancyclovir, solumedrol and interferon (IFN). The third case received ASCT with an unmanipulated autograft for relapsed angioimmunoblastic lymphoma. He also achieved a complete response but only after rituximab was added to IVIG, gancyclovir, solumedrol and IFN. None of these patients experienced a relapse of their PTLD with follow-up ranging from 1.5 to 5 years. These cases highlight the importance of considering PTLD in the differential diagnosis of lymphadenopathy and fever post ASCT. They also demonstrate the possibility of durable complete remission of post-ASCT PTLD following antiviral and immune modulating therapy.

Psoralen-modified clamp-forming antisense oligonucleotides reduce cellular c-Myc protein expression and B16-F0 proliferation

The c-myc protooncogene plays an important role in the abnormal growth pattern of melanoma cells. In an attempt to inhibit c-Myc expression and the growth of an established murine melanoma cell line, we targeted homopurine sequences within the mouse myc mRNA with modified antisense oligonucleotides (AS ODNs). Psoralen was conjugated to the 5'-end of these clamp-forming oligonucleotides (clamp ODNs). Gel mobility shift analysis demonstrated a sequence-specific interaction between the active clamp ODNs (Myc-E2C and Myc-E3C) and the 1.4 kb c-myc mRNA, but no interaction with the control clamp ODN (SCR**). This association was further confirmed by thermal denaturation studies. In vitro translation assays demonstrated that both Myc-E2C and Myc-E3C at 5 microM inhibited c-Myc expression >99% after UV activation at 366 nm. Immunostaining of B16-F0 cells with a c-Myc monoclonal antibody revealed a significant reduction in c-Myc after clamp ODN treatment compared with the untreated or SCR** control-treated cells. This result was corroborated by western blot analysis. Utilizing the MTT assay to determine the effects of ODN-mediated c-Myc reduction on B16-F0 growth, we observed 60 and 64% reductions in growth after treatment with 5 microM Myc-E3C and Myc-E2C, respectively. We attribute the enhanced effectiveness of the clamp ODNs to psoralen activation. Our preliminary data suggest that inhibiting c-Myc overexpression results in a significant reduction in abnormal proliferation of B16-F0 melanoma cells and that the increased efficiency of clamp ODNs may provide an important advantage for their use in antisense therapies.

The CD3- 16+ 56+ NK cell count independently predicts autologous blood stem cell mobilization

Better predictive factors for autologous blood stem cell mobilization (BSCM) are needed. The purpose of this study was to determine if an independent association exists between lymphocyte or NK cell counts and BSCM. Data were analyzed on 141 consecutive patients aged 19-69 years (median 45) who received combined chemotherapy plus G-CSF for BSCM, and who had measurements of immune cells prior to BSCM. Of the 141 patients, 41% had breast cancer, 14% Hodgkin's disease, 34% non-Hodgkin's lymphoma, and 11% other diagnoses. BSCM involved dose-intensive cyclophosphamide, etoposide, cisplatin (DICEP) plus G-CSF 300 microg (<70 kg) or 480 microg (>70 kg) for 45% of patients, while the remaining 55% received other chemotherapy plus similar doses of G-CSF. Only a single apheresis was performed for 94% of patients. The following factors were analyzed for predictors of BSCM: age, gender, prior chemotherapy, prior radiotherapy, diagnosis, disease status, marrow involvement, mobilization regimen, Hb, WBC, platelet count, B cell, T cell, and NK cell counts. The peripheral blood CD34+ counts on the first day of apheresis (PBCD34) were 6-1783 x 10(6)/l (median 150). The PBCD34 count correlated strongly with the number of CD34+ cells collected/l blood apheresed and with the number of CD34+ cells collected/kg. By multivariate analysis using continuous variables, relapsed status (P = 0.0003), not using DICEP mobilization (P = 0.0001), female gender (P = 0.0057), low platelet count (P = 0.051), and low CD3- 16+ 56+ count (P = 0.0158) were associated with low PBCD34 counts. Using categorical variables, the only factors that independently predicted a PBCD34 count <150 x 10(6)/l were: >1 prior chemotherapy regimen (odds ratio = 5.12, P = 0.0003), not using DICEP mobilization (odds ratio = 4.94, P = 0.0001), and CD3- 16+ 56+ count <125 x 10(6)/l (odds ratio= 2.58, P = 0.0157). In conclusion, the CD3- 16+ 56+ count may be a useful additional predictor of BSCM and warrants further study.

Eating disorder examination questionnaire: norms for young adolescent girls

This paper reports young adolescent female norms for the Eating Disorder Examination Questionnaire (EDE-Q). The standardization sample was comprised of 808 girls aged between 12 and 14 years from three single-sex schools (one private and two state schools). Means, standard deviations and percentile ranks for raw EDE-Q subscale scores are presented. Prevalence figures for key eating disorder behaviors over the previous two weeks were as follows: 4% self-induced vomiting; 1% laxative misuse; 0.4% diuretic misuse; and 8% regular binge eating.

Modification of eating attitudes and behavior in adolescent girls: A controlled study

OBJECTIVE

The aim of this study was to evaluate the effectiveness of a school-based eating disorder prevention program designed to reduce dietary restraint and concern about shape and weight among adolescent girls.

METHOD

A total of 474 girls aged 13-14 years received the program as part of their normal school curriculum. An assessment-only control group included 386 pupils. Measures of eating disorder features, self-esteem, and knowledge were administered before and after the intervention and at 6-month follow-up.

RESULTS

Immediately following the intervention, there was a small reduction in dietary restraint and attitudes to shape and weight in the index group, whereas there was no change in the control group. This reduction was not maintained at 6-month follow-up although the dietary restraint scores of the index group remained lower than those of the control group.

DISCUSSION

This prevention program achieved change in eating attitudes and behavior, although the change was modest in size and not sustained. Focusing on a high-risk subgroup of dieters might be a more fruitful primary prevention strategy.

Adenovirus type 5 viral particles pseudotyped with mutagenized fiber proteins show diminished infectivity of coxsackie B-adenovirus receptor-bearing cells

A major limitation of adenovirus type 5 (Ad5)-based gene therapy, the inability to target therapeutic genes to selected cell types, is attributable to the natural tropism of the virus for the widely expressed coxsackievirus-adenovirus receptor (CAR) protein. Modifications of the Ad5 fiber knob domain have been shown to alter the tropism of the virus. We have developed a novel system to rapidly evaluate the function of modified fiber proteins in their most relevant context, the adenoviral capsid. This transient transfection/infection system combines transfection of cells with plasmids that express high levels of the modified fiber protein and infection with Ad5.beta gal.Delta F, an E1-, E3-, and fiber-deleted adenoviral vector encoding beta-galactosidase. We have used this system to test the adenoviral transduction efficiency mediated by a panel of fiber protein mutants that were proposed to influence CAR interaction. A series of amino acid modifications were incorporated via mutagenesis into the fiber expression plasmid, and the resulting fiber proteins were subsequently incorporated onto adenoviral particles. Mutations located in the fiber knob AB and CD loops demonstrated the greatest reduction in fiber-mediated gene transfer in HeLa cells. We also observed effects on transduction efficiency with mutations in the FG loop, indicating that the binding site may extend to the adjacent monomer in the fiber trimer and in the HI loop. These studies support the concept that modification of the fiber knob domain to diminish or ablate CAR interaction should result in a detargeted adenoviral vector that can be combined simultaneously with novel ligands for the development of a systemically administered, targeted adenoviral vector.

A qualitative study of the transition to adulthood for youth with physical disabilities

The purpose of this qualitative study was to explore the experiences, perceptions, and needs of youth with physical disabilities in transition from adolescence to adulthood. Purposeful sampling strategies were used to select 34 study participants who lived in three regions of south-central Ontario, Canada. Data collection methods were individual and focus group interviews, and were guided by a set of open-ended questions. An editing style of analysis sorted the text into codes for description and interpretation. Themes emerged about context, the transition process, needs, and services. Participants identified a poor fit between young persons with disabilities and the adult world they were entering. They recommended that services be focused on environmental supports to enable them to "build their own bridges" to the adult world. Community-based transition services need to be planned in collaboration with youth with disabilities and their parents. Concepts of person-environment fit and health promotion can be incorporated into services to enable young persons with disabilities to experience a smooth transition from adolescence to adulthood.

Predictive factors for long-term engraftment of autologous blood stem cells

Data from 170 consecutive patients aged 19-66 years (median age 46 years) who underwent unmanipulated autologous blood stem cell transplant (ASCT) were analyzed to determine if total CD34+ cells/kg infused, CD34+ subsets (CD34+41+, CD34+90+, CD34+33-, CD34+38-, CD34+38-DR-), peripheral blood CD34+ cell (PBCD34+) count on first apheresis day, or various clinical factors were associated with low blood counts 6 months post ASCT. Thirty-four patients were excluded from analysis either because of death (n = 17) or re-induction chemotherapy prior to 6 months post ASCT (n = 13), or because of lack of follow-up data (n = 4). Of the remaining 136 patients, 46% had low WBC ( < 4 x 10(9)/l), 41% low platelets (<150 x 10(9)/l), and 34% low hemoglobin ( < 120 g/l) at a median of 6 months following ASCT. By Spearman's rank correlation, both the total CD34+ cell dose/kg and the PBCD34+ count correlated with 6 month blood counts better than any subset of CD34+ cells or any clinical factor. The PBCD34+ count was overall a stronger predictor of 6 month blood counts than was the total CD34+ cells/kg infused. Both factors retained their significance in multivariate analysis, controlling for clinical factors. In conclusion, subsets of CD34+ cells and clinical factors are inferior to the total CD34+ cell dose/kg and PBCD34+ count in predicting 6 month blood counts following ASCT.

Documenting English syntactic development in face-to-face signed communication

The authors explored the face-to-face English competence of five students who were participating in a larger study of teachers' use of English-based signing. Using case studies, the authors report on the students' development of English-based signing at the beginning and end of their involvement in this 4-year study. Grammatical forms similar in English and American Sign Language (ASL) were initially more readily produced when tested for in English, and showed consistently higher attainment levels across all the students, than grammatical forms that are different in English and ASL. The authors found emerging English forms that could be documented (a) between prompted and imitated utterances and (b) within blocks of test items examining the same grammatical constructions. The authors conclude that teachers' concerted efforts to use English-based signing as a language of instruction enhance deaf students' English acquisition. Such signing helps build a bridge between native sign language and the development of English skills necessary for literacy.

Antiangiogenic gene therapy for cancer via systemic administration of adenoviral vectors expressing secretable endostatin

A growing number of antiangiogenesis strategies have been investigated for the treatment of cancer and other angiogenesis-dependent diseases. One of the most promising strategies is to systemically administer one or more antiangiogenic proteins frequently enough to achieve a sufficient long-term steady state level of the protein(s) to achieve the maximum beneficial effect. However, the utility of this strategy is limited because of many technical difficulties, including obtaining both the quantity and quality of the protein(s) necessary for optimal therapeutic benefit. To overcome these difficulties, we hypothesized that a single administration of a replication-defective adenoviral vector expressing a secretable antiangiogenic protein could achieve an optimal long-term systemic concentration. We constructed a recombinant adenoviral vector, Av3mEndo, which encodes a secretable form of murine endostatin. We demonstrated secretion of endostatin from several cell lines transduced with Av3mEndo. Partially purified endostatin secreted from Av3mEndo-transduced mammalian cells was shown to potently inhibit endothelial cell migration in vitro. A single intravenous administration of Av3mEndo in mice was shown to result in (1) prolonged and elevated levels of circulating endostatin, (2) partial inhibition of VEGF-induced angiogenesis in a VEGF implant angiogenesis model, and (3) prolonged survival and in 25% of mice the complete prevention of tumor growth in a prophylactic human colon/liver metastasis xenograft murine model. These results support our contention that adenoviral vector-mediated expression of an antiangiogenic protein(s) represents an attractive therapeutic approach to cancer and other angiogenesis-dependent diseases.

Early gastric post-transplantation lymphoproliferative disorder and H pylori detection after kidney transplantation: a case report and review of the literature

The incidence of post-transplantation lymphoproliferative disorder (PTLD) in the adult renal transplant population ranges from 0.7% to 4%. The majority of cases involve a single site and arise, on average, seven months after transplantation. Histopathology usually reveals B-cell proliferative disease and has been standardized into its own classification. Treatment modalities consist of decreased immunosuppression, eradication of Epstein-Barr virus, surgical resection, systemic chemotherapy and monoclonal antibody therapy; however, mortality remains high, typically with a short survival time. In patients who have undergone renal transplantation, approximately 10% of those with PTLDs present with gastrointestinal symptomatology and disease. Reported sites include the stomach, and small and large bowel. Very few cases of Helicobacter pylori or mucosal-associated lymphoid tissue have been described in association with PTLD. In the era of cyclosporine immunosuppression, the incidence of PTLD affecting the gastrointestinal tract may be increasing in comparison with the incidence seen with the use of older immunosuppression regimens. A case of antral PTLD and H pylori infection occurring three months after renal transplantation is presented, and the natural history and management of gastric PTLD are reviewed.

Double high-dose therapy for Hodgkin's disease with dose-intensive cyclophosphamide, etoposide, and cisplatin (DICEP) prior to high-dose melphalan and autologous stem cell transplantation

We previously reported a 50% (95% CI = 33-76%) 5 year event-free survival (EFS) rate for 23 patients with Hodgkin's disease (HD) who received salvage therapy with single agent high-dose melphalan (HDM) and autologous stem cell transplantation (ASCT). Predictors of poor outcome included bulky disease and initial remission <1 year. Since 1995, similar poor prognosis patients have been treated with double high-dose therapy consisting of dose-intensive cyclophosphamide 5.25 g/m2, etoposide 1.05 g/m2, cisplatin 105 mg/m2 (DICEP) for tumor cytoreduction and stem cell mobilization followed by HDM/ASCT. The purpose of the present study is to determine if the use of DICEP is associated with improved event-free (EFS) and overall survival (OAS) for patients treated with HDM/ASCT. From February 1981 to June 1999, 46 consecutive patients received HDM/ASCT for relapsed (n = 35) or refractory (n = 11) HD. DICEP re-induction and blood stem cell mobilization was used for 21 patients. Factors considered for univariate and multivariate analyses included age at transplant, number of failed chemotherapy regimens, prior radiotherapy, length of initial remission, relapsed or refractory disease status, extranodal relapse, B symptoms at relapse, bulk, post-ASCT radiotherapy, and DICEP re-induction therapy. Cox proportional hazards models were constructed for both event and death. DICEP and HDM were well tolerated with no early treatment-related mortality or toxicity requiring life-sustaining measures. For all 46 patients, the projected 5 year EFS was 52% (95% CI = 38-72%) and OAS was 57% (95% CI = 40-82). Factors independently associated with relapse in multivariate analysis included bulk >5 cm (RR = 6.38, P = 0.002), prior radiotherapy (RR = 3.59, P = 0.027), and not using DICEP (RR = 5.29, P = 0.005). Factors independently associated with death included bulk >5 cm (RR = 5.13, P = 0.009), > or =3 prior chemotherapy regimens (RR = 4.72, P = 0.019), and not using DICEP (RR = 7.49, P = 0.015). This study demonstrates that DICEP re-induction prior to HDM/ASCT is feasible. The preliminary data are sufficiently encouraging to warrant a multicenter phase II or a phase III trial evaluating DICEP followed by HDM/ASCT as salvage therapy for HD.

A comparison of inpatient and outpatient ASCT

Outpatient high-dose chemotherapy and autologous stem cell transplantation (ASCT) has been shown to be feasible in terms of physical morbidity and mortality outcomes, but few data exist on the psychosocial impact of delivering such aggressive therapy in this manner. The purpose of this observational study was to compare effects of inpatient (n = 20) and outpatient (n = 21) modes of care on physical status, psychological well-being, quality of life, personal finances and caregiver burden. Most patients were treated according to their preference for inpatient or outpatient care. Those choosing outpatient care were screened for eligibility according to established criteria for ambulatory management. Measures were taken at baseline, then at days 4-6, 12-16 and 30 post ASCT. Results showed that overall, the psychological, physical, social and financial outcomes of the outpatient ASCT group were comparable, to or better than inpatients. Factors that seem to be important for successful outpatient management are previous experience with cancer treatment, a satisfying quality of life, physical well-being, patient's preference for a particular mode of care and physical proximity to the treatment centre. The study results suggest that outpatient ASCT is an efficient, effective and acceptable form of care for motivated patients and caregivers who have the physical and psychological capability and desire to receive cancer treatment in this manner.