Saving in medical costs by achieving guideline-based asthma symptom control: a population-based study.

BACKGROUND: Asthma control is increasingly used as an outcome measure in asthma trials. Economic evaluations of asthma interventions require converting the impact of interventions on control to impact on resource use. The purpose of this study was to estimate the savings in direct costs by achieving asthma symptom control as defined in the Global Initiative for Asthma (GINA) 2014 management strategy. METHODS: Adolescents and adults with asthma were recruited through random digit dialing. Asthma control per GINA and the use of healthcare resources were assessed at baseline and three-monthly visits up to 1 year. We used regression models to associate costs, measured in 2012 Canadian dollars ($), with symptom control, adjusting for potential confounding variables. RESULTS: The final sample included 517 individuals (average age 48.9, 65.8% female) with mostly mild-moderate asthma contributing 2033 follow-up visits. In 598 (29.4%), 809 (39.8%), and 626 (30.8%) of visits, asthma was symptomatically controlled, partially controlled, or uncontrolled, respectively. The average 3-month costs of asthma were $134.5. Of these, 20.5% were attributable to inpatient care, 47.8% to outpatient care, and 31.5% to medication. Compared to controlled asthma, partially controlled asthma was associated with a nonsignificant increase of $9.5 (95% CI -$13.6 - $32.6) in adjusted 3-month costs and uncontrolled asthma with a statistically significant increase of $81.7 (95% CI $48.5 - $114.9). CONCLUSION: A substantial fraction of this population-based sample of largely mild-moderate asthmatics was symptomatically uncontrolled. Achieving symptom control was associated with a reduction in direct costs. The adjusted values from this study can be used to inform cost-effectiveness analyses of asthma treatments.

Results of surgical treatment of calcaneus insertional tendinopathy in middle- and long-distance runners.

PURPOSE: Calcaneus insertional tendinopathy in runners is common and involves important therapeutic controversies. The object of this study was to determine the delay and level of return to sport after insertional surgery in runners, with and without tendon damage. METHODS: Eighteen runners underwent surgery for insertional calcaneus tendinopathy. Nine required an exostosectomy/bursectomy, and nine others required a tendon reinsertion/autograft. All patients were clinically assessed pre- and post-operatively with AOFAS scores and post-operatively with ATRS. This series included analysis of "pure conflicts" and "severe insertional lesion" scores. If the insertional tendon was free or the lesion was smaller than 50 %, the group was classified as "pure conflict/minor tendon damage". In the situation in which a loss of tendon occurred or the tendon lesion was greater than 50 %, the group was classified as "major tendon damage". Pre-operatively, the AOFAS "overall", "pure conflicts/minor tendon damage" and "major tendon damage" groups' scores were 58.5 ± 15, 68.2 ± 8.8 and 48.9 ± 13.9/100, respectively. RESULTS: Post-operatively, the AOFAS "overall", "pure conflicts/minor tendon" and "major tendon damage" groups' scores were 93.7 ± 8.2, 93.2 ± 10.2 and 95.2 ± 5.7/100, respectively. The AOFAS score gain for each group was, respectively, 35.2 ± 19, 24 ± 17 and 46.3 ± 14.1. The ATRS "overall", "pure conflicts/minor tendon damage" and "major tendon damage" groups' scores were 81.5 ± 14.9, 78.3 ± 20.1 and 84.7 ± 6.7/100, respectively. The global sport recovery delay was 9.3 ± 4.1 months; it was 6 ± 3.3 months for the pure conflict/minor tendon damage subgroup and 10 ± 4.6 months for the severe tendon damages subgroup. CONCLUSION: Achilles insertional tendinopathy surgery on this population results in few complications with good functional results if the surgical technique is adapted to the type of tendon injury. The clinical relevance of this study is that it highlights the various forms of calcaneus insertional tendinopathy and various treatment options. The authors show that in the case of major tendon damage, time to return to sport is longer.

Structurally diverse MDM2-p53 antagonists act as modulators of MDR-1 function in neuroblastoma.

BACKGROUND: A frequent mechanism of acquired multidrug resistance in human cancers is overexpression of ATP-binding cassette transporters such as the Multi-Drug Resistance Protein 1 (MDR-1). Nutlin-3, an MDM2-p53 antagonist, has previously been reported to be a competitive MDR-1 inhibitor. METHODS: This study assessed whether the structurally diverse MDM2-p53 antagonists, MI-63, NDD0005, and RG7388 are also able to modulate MDR-1 function, particularly in p53 mutant neuroblastoma cells, using XTT-based cell viability assays, western blotting, and liquid chromatography-mass spectrometry analysis. RESULTS: Verapamil and the MDM2-p53 antagonists potentiated vincristine-mediated growth inhibition in a concentration-dependent manner when used in combination with high MDR-1-expressing p53 mutant neuroblastoma cell lines at concentrations that did not affect the viability of cells when given alone. Liquid chromatography-mass spectrometry analyses showed that verapamil, Nutlin-3, MI-63 and NDD0005, but not RG7388, led to increased intracellular levels of vincristine in high MDR-1-expressing cell lines. CONCLUSIONS: These results show that in addition to Nutlin-3, other structurally unrelated MDM2-p53 antagonists can also act as MDR-1 inhibitors and reverse MDR-1-mediated multidrug resistance in neuroblastoma cell lines in a p53-independent manner. These findings are important for future clinical trial design with MDM2-p53 antagonists when used in combination with agents that are MDR-1 substrates.

Combination of clonidine sedation and spontaneous breathing-pressure support upon acute respiratory distress syndrome: a feasibility study in four patients.

INTRODUCTION: As alpha-2 agonists preserve ventilator drive, patients presenting with acute respiratory distress syndrome (ARDS, Pa02/FiO2 < 200) were managed using sedation with an alpha-2 agonist, clonidine, combined to spontaneous ventilation (SV) + pressure support ventilation (PS). METHODS: Sedation was provided by an alpha-2 agonist, clonidine 1-2 microg x kg(-1( x h(-1), without bolus administration, and supplemented with a neuroleptic, loxapine, if needed. Four patients presenting with ARDS were managed with pressure support ventilation (PS = 8 cm H20,rarely 10-12 cm H20) and high PEEP (10-20 cm H20). Energy requirements were minimized, if appropriate, with hypothermia caused by extra-renal replacement therapy or intentional hypothermia (35-36 degrees C). Repeated echocardiographic examinations revealed no right ventricular failure. RESULTS: Recovery of ARDS, i.e. sustained increase of P/F > 200 for > 24 h, was observed, over 2-5 days. CONCLUSION: Use of an alpha-2 agonist as first-line sedative agent led to absence of respiratory depression and spontaneous ventilation. Upon ARDS, the lowered intrathoracic pressure observed with SV+PSV allowed one to recruit alveoli with high levels of PEEP, without impairing right ventricle function.

Diagnosis clinical criteria of sport related concussion: Toward an operational criteria definition in France.

OBJECTIVE: An expert working group was set up at the initiative of the French Ministry of Sports with the objective of harmonising the management of sport related concussion (SRC) in France, starting with its definition and diagnosis criteria. RESULTS: Definition: A clinical definition in 4 points have been established as follows: Concussion is a brain injury: 1) caused by a direct or indirect transmission of kinetic energy to the head; 2) resulting in an immediate and transient dysfunction of the brain characterised by at least one of the following disorders: a) Loss of consciousness, b) loss of memory, c) altered mental status, d) neurological signs; 3) possibly followed by one or more functional complaints (concussion syndrome); 4) the signs and symptoms are not explained by another cause. Diagnosis criteria: In the context of the direct or indirect transmission of kinetic energy to the head, the diagnosis of concussion may be asserted if at least one of the following signs or symptoms, observed or reported, is present within the first 24hours and not explained by another cause: 1) loss of consciousness; 2) convulsions, tonic posturing; 3) ataxia; 4) visual trouble; 5) neurological deficit; 6) confusion; 7) disorientation; 8) unusual behaviour; 9) amnesia; 10) headaches; 11) dizziness; 12) fatigue, low energy; 13) feeling slowed down, drowsiness; 14) nausea; 15) sensitivity to light/noise; 16) not feeling right, in a fog; 17) difficulty concentrating. CONCLUSION: Sharing the same definition and the same clinical diagnostic criteria for concussion is the prerequisite for common rules of management for all sports and should allow the pooling of results to improve our knowledge of this pathology.

Evidence of a clinical response at one yr after reduced-intensity allogeneic hematopoietic stem cell transplantation in heavily pretreated adolescents with aggressive refractory Hodgkin's lymphoma.

We report results of RIC AHSCT in four adolescents with aggressive refractory HL. They all received three or four lines of therapy prior to RIC-AHSCT including autografts. At the time of RIC, they were in partial response except for one patient who had progressive chemoresistant disease. The conditioning regimen consisted of fludarabin, busulfan and ATG. They all had a matched related donor. The median follow-up was 12-16-month post-allograft. All patient transplants engrafted rapidly. The median time of hospitalization was 35 days. The median time to neutrophil recovery (>or=500/muL) was 19 days. All the patients were in complete donor chimerism at day 60. Four patients developed skin (grade

Non-invasive imaging correlates with histological and molecular characteristics of an osteosarcoma model: application for early detection and follow-up of MDR phenotype.

BACKGROUND: In an orthotopic rat osteosarcoma model, histological and molecular findings were compared with the results of non-invasive imaging methods to assess disease progression at the primary site, the pattern of metastatic dissemination and the chemoresistance phenotype. MATERIALS AND METHODS: Primary tumor engraftment, vascularization, growth and metastatic spread were evaluated using 18FDG tomoscintigraphy. Bone neoformation in the primary tumor and metastasis was determined using 18FNa confirmed by classical histological studies. Chemoresistance phenotype was assessed by analysis of MDR1 and MRP1 genes expression compared to 99mTc MIBI imaging. RESULTS: 99mTc MIBI imaging correlated with the overexpression of the MDR1 and MRP1 genes. 18FDG, 18FNa and 99mTc tomoscintigraphies revealed that the pattern of vascularization, bone neoformation and hematogeneous metastatic dissemination in our animal model mimics its human counterpart. CONCLUSION: Multimodality, non-invasive imaging is a valid surrogate marker of histological and molecular characteristics in an orthotopic osteosarcoma model in immunocompetent rats; it allows extensive in vivo follow-up of osteosarcoma, including longitudinal analysis of chemoresistance.

Functional and ultrasonographic outcomes after surgical fibular tendon stabilisation by isolated re-tensioning of the superior fibular retinaculum.

BACKGROUND: Fibular tendon dislocation is a rare and usually sports-related injury. We report the functional and ultrasonographic outcomes of a simple technique for re-tensioning the superior fibular retinaculum. HYPOTHESIS: Our retinaculum re-tensioning technique is not followed by recurrent fibular tendon dislocation, as demonstrated by ultrasonography. MATERIAL AND METHOD: This single-centre single-surgeon retrospective study included 17 patients who underwent surgery to treat fibular tendon dislocation between January 2008 and December 2013. The functional outcome at last follow-up was assessed based on the AOFAS score. Subjective patient satisfaction and return to sports were recorded. Dynamic comparative ultrasonography was performed at last follow-up and the results used to separate the patients into four categories: normal, recurrent dislocation, subluxation, and residual tendinopathy. RESULTS: The 17 patients had a mean age of 32.6±9.7 years (range, 18-52 years) and a mean pre-operative AOFAS score of 59.9±11.3 (range, 34-71). Mean follow-up was 36.9±16.9 months (range, 12-60 months). The mean AOFAS score at last follow-up was 89±9.0 (range, 68-100). Of the 17 patients, 7 (41%) returned to the same level of sports. The remaining 10 patients returned to a lower level or did not return to sports, usually (70%) for personal or work-related reasons. Follow-up ultrasonography was normal in 12 (71%) patients. Of the remaining 5 patients, 2 had clinically silent recurrent dislocation and 3 had residual tendinopathy, including 1 who was only moderately satisfied due to persistent pain. Of the 4 patients who reported pain due to the knots in the non-absorbable sutures used to tighten the retinaculum, 1 required removal of the sutures. No other complications were recorded. Finally, 16 (94%) patients were satisfied or very satisfied. DISCUSSION: Retinaculum re-tensioning is effective in stabilising the fibular tendons, with no true recurrences. Ultrasonography can detect clinically silent subluxation. This simple and reproducible technique is associated with a very low complication rate and with excellent functional and anatomical outcomes. LEVEL OF EVIDENCE: Retrospective, level IV.

Organization in response to massive afflux of war victims in civilian practice - experimental feedback from the November 2015 Paris terrorist attacks.

The arrival of a large number of war-weapon casualties at a civilian trauma center requires anticipation. A plan defining the management principles and the respective roles of the involved physicians and nurses and their interaction with each other is essential. Uni-directional patient flow associated with adequate numbers of staff physicians and nurses under the leadership of a medical director is essential to prevent the overwhelming of the trauma center. Routine and regular interaction between the pre-hospital medical flow control system and the medical director, on one hand, and between surgical teams and the medical director, on the other, are necessary to know when to apply "damage control" surgical techniques. Based on the feedback of a level 1 trauma center that received 53 victims of the November 13, 2015 terrorist attack in Paris, we present the factors of success, and the stumbling blocks.

Vaccination to improve the persistence of CD19CAR gene-modified T cells in relapsed pediatric acute lymphoblastic leukemia.

Trials with second generation CD19 chimeric antigen receptors (CAR) T-cells report unprecedented responses but are associated with risk of cytokine release syndrome (CRS). Instead, we studied the use of donor Epstein-Barr virus-specific T-cells (EBV CTL) transduced with a first generation CD19CAR, relying on the endogenous T-cell receptor for proliferation. We conducted a multi-center phase I/II study of donor CD19CAR transduced EBV CTL in pediatric acute lymphoblastic leukaemia (ALL). Patients were eligible pre-emptively if they developed molecular relapse (>5 × 10-4) post first stem cell transplant (SCT), or prophylactically post second SCT. An initial cohort showed poor expansion/persistence. We therefore investigated EBV-directed vaccination to enhance expansion/persistence. Eleven patients were treated. No CRS, neurotoxicity or graft versus host disease (GVHD) was observed. At 1 month, 5 patients were in CR (4 continuing, 1 de novo), 1 PR, 3 had stable disease and 3 no response. At a median follow-up of 12 months, 10 of 11 have relapsed, 2 are alive with disease and 1 alive in CR 3 years. Although CD19CAR CTL expansion was poor, persistence was enhanced by vaccination. Median persistence was 0 (range: 0-28) days without vaccination compared to 56 (range: 0-221) days with vaccination (P=0.06). This study demonstrates the feasibility of multi-center studies of CAR T cell therapy and the potential for enhancing persistence with vaccination.

Interfacial electrostatics of self-assembled monolayers of alkane thiolates on Au(111): work function modification and molecular level alignments.

We have isolated at T < 150 K a weakly adsorbed dimethyl disulfide (DMDS) layer on Au(111) and studied how the vibrational states, S core hole level shifts, valence band photoemission, and work function measurements evolve upon transforming this system into chemisorbed methylthiolate (MT) self-assembled monolayers (SAM) by heating above 200 K. By combining these observations with detailed theoretical electronic structure simulations, at the density functional level, we have been able to obtain a detailed picture of the electronic interactions at the interface between Au and adsorbed thiolates and disulfides. All of our measurements may be interpreted with a simple model where MT is bound to the Au surface with negligible charge transfer. Interfacial dipoles arising from Pauli repulsion between molecule and metal surface electrons are present for the weakly adsorbed DMDS layer but not for the chemisorbed species. Instead, for the chemisorbed species, interfacial dipoles are exclusively controlled by the molecular dipole, its interaction with the dipoles on neighboring molecules, and its orientation to the surface. The ramifications of these results for alignment of molecular levels and interfacial properties of this class of materials are discussed.

Return to sports and functional results after revision anterior cruciate ligament reconstruction by fascia lata autograft.

INTRODUCTION: The surgical revision rate following anterior cruciate ligament (ACL) surgery is 3% at 2 years and 4% at 5 years. Revision ACL surgery raises the question of the type of graft to be used. The present study assessed return to sports and functional results after revision ACL reconstruction by fascia lata graft. The hypothesis was that fascia lata provides a reliable graft in revision ACL surgery. MATERIAL AND METHODS: A single-center retrospective continuous study included 30 sports players with a mean age of 26.8±8 years undergoing surgical revision for iterative ACL tear between 2004 and 2013. Multi-ligament lesions were excluded. Type and level of sports activity were assessed preoperatively, after primary surgery and at end of follow-up. Clinical assessment used subjective IKDC, Lysholm and KOOS scores. RESULTS: At a mean 4.6±1.6 years' follow-up, all patients had resumed sport activity, but only 12 with the same sport at the same level. Median subjective IKDC score increased from 57 [54.3; 58.5] preoperatively to 82 [68.3; 90] at last follow-up, and Lysholm score from 46 [42.3; 51] to 90.5 [80.8; 96.8]; KOOS score at last follow-up was 94.7 [83; 100]. CONCLUSION: Functional results in revision ACL reconstruction by fascia lata graft were satisfactory, with similar return-to-sports rates as with other techniques. Fascia lata provides a reliable graft in revision ACL surgery. LEVEL OF EVIDENCE: IV, retrospective study.

Arthroscopic treatment of acute acromioclavicular dislocations using a double button device: Clinical and MRI results.

INTRODUCTION: Arthroscopic treatment of acute grade 3 and 4 acromioclavicular dislocation is controversial, due to the risk of recurrence and of postoperative reduction defect. The purpose of the present study was to investigate whether the healing of the acromioclavicular (AC) and coracoclavicular (CC) ligaments and the accurate 3D positioning parameters of the AC joint using MRI were correlated with satisfactory functional outcome. MATERIAL: Thirty-nine patients were enrolled from 2009 to 2011 and managed arthroscopically by CC lacing using a double-button device. METHODS: Clinical assessment included the Shoulder and Hand (QuickDash) score, Constant-Murley score and visual analog scale (VAS) for residual pain. Time and rate to return to work and return to sport were assessed according to type of sport and work. Postoperative complications were recorded. Radiological examination consisted of anteroposterior clavicle and lateral axillary radiographs. AC ligament healing and 3D joint congruency were assessed on MRI and correlated to the clinical results. RESULTS: Mean patient age was 35.7 years (range, 20-55). Mean follow-up was 42.3±10.6 months (range, 24-60). At final follow-up, mean QuickDash score, Constant score and VAS were respectively 1.7±4 (range, 0-11), 94.7±7.3 (range, 82-100) and 0.5±1.4 (range, 0-2). Thirty-five (90%) patients were able to resume work, including heavy manual labor, and sport. Radiology found accurate 3D joint congruency in 34 patients (87%) and CC and AC ligament healing in 36 (93%). Complications included reduction loss at 6 weeks in 3 patients, requiring surgical stabilization. Satisfactory functional results were associated with accurate AC joint congruency in the coronal and axial planes (P<0.05) and good AC and CC ligament healing (P<0.04). An initial 25% reduction defect in the coronal plane was not associated with poor functional results (P=0.07). CONCLUSION: Arthroscopic treatment by CC lacing satisfactorily restored ligament and joint anatomy in the present series. These satisfactory anatomic results correlated with good clinical outcome encourage continuing with this technique. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Iliac Crest Avulsion Fracture in a Young Sprinter.

Avulsion fracture of the iliac crest is an uncommon pathology. It usually occurs in teenagers during sport activities, more common in boys. We report a case of 16-year-old male competitive sprinter, who had an avulsion of a part of the iliac crest and the anterior-superior iliac spine during a competition. The traumatism occurred during the period of acceleration phase out of the blocks which corresponds to the maximum traction phase on the tendons. Then a total loss of function of the lower limb appears forcing him to stop the run. X-ray and CT scan confirmed the rare diagnosis of avulsion of the quasitotality of the iliac crest apophysis, corresponding to Salter 2 fracture. We performed an open reduction and internal fixation with two screws, allowing a return to sport after 3 months and his personal best record in the 100 meters at the 6th postoperative month.

Autologous antileukemic immune response induced by chronic lymphocytic leukemia B cells expressing the CD40 ligand and interleukin 2 transgenes.

Although the B cells of chronic lymphocytic leukemia (B-CLL cells) express both tumor-specific peptides and major histocompatibility complex (MHC) class I antigens, they lack the capacity for costimulatory signaling, contributing to their protection against host antitumor immunity. To stimulate CLL-specific immune responses, we sought to transfer the human CD40 ligand (hCD40L) gene to B-CLL cells, using an adenoviral vector, in order to upregulate costimulating factors on these cells. Because efficient gene transduction with adenoviral vectors requires the expression of virus receptors on target cells, including the coxsackievirus B-adenovirus receptors (CAR) and alpha(v) integrins, we cocultured B-CLL cells with human embryonic lung fibroblasts (MRC-5 line). This exposure led to increased expression of integrin alpha(v)beta3 on B-CLL cells, which correlated with higher transduction rates. Using this novel prestimulation system, we transduced B-CLL cells with the hCD40L gene. The Ad-hCD40L-infected cells had higher expression of B7 molecules and induced activation of autologous T cells in vitro, but these T cells could not recognize parental leukemic cells. By contrast, an admixture of Ad-hCD40L-positive cells and leukemic cells transduced with the human interleukin 2 (IL-2) gene produced greater T cell activation than did either immunostimulator population alone. Importantly, this combination generated autologous T cells capable of specifically recognizing parental B-CLL cells. These findings suggest that the combined use of genetically modified CD40L-expressing B-CLL cells in combination with IL-2-expressing B-CLL cells may induce therapeutically significant leukemia-specific immune responses.

Transgenic expression of CD40L and interleukin-2 induces an autologous antitumor immune response in patients with non-Hodgkin's lymphoma.

The malignant B cells of non-Hodgkin's lymphoma (B-NHL cells) express peptides derived from tumor-specific antigens such as immunoglobulin idiotypes, and also express major histocompatibility complex antigens. However, they do not express co-stimulatory molecules, which likely contributes to their protection from host antitumor immunity. To stimulate NHL-specific immune responses, we attempted to transfer the human CD40 ligand (hCD40L) gene to B-NHL cells and enhance their co-stimulatory potential. We found that an adenoviral vector encoding human CD40L (AdhCD40L) was ineffective at transducing B-NHL cells because these cells lack the coxsackievirus B-adenovirus receptor and alpha(v) integrins. However, preculture of the B-NHL cells with the human embryonic lung fibroblast line, MRC-5, significantly up-regulated expression of integrin alpha(v)beta 3 and markedly increased their susceptibility to adenoviral vector transduction. After prestimulation, transduction with AdhCD40L increased CD40L expression on B-NHL cells from 1.3+/-0.2% to 40.8+/-11.9%. Transduction of control adenoviral vector had no effect. Expression of transgenic human CD40L on these CD40-positive cells was in turn associated with up-regulation of other co-stimulatory molecules including B7-1/-2. Transduced B-NHL cells were now able to stimulate DNA synthesis of autologous T cells. However, the stimulated T cells were unable to recognize unmodified lymphoma cells, a requirement for an effective tumor vaccine. Based on previous results in an animal model, we determined the effects of combined use of B-NHL cells transduced with AdhCD40L and AdhIL2 vectors. The combination enhanced initial T-cell activation and generated autologous T cells capable of specifically recognizing and killing parental (unmodified) B-NHL cells via major histocompatibility complex--restricted cytotoxic T lymphocytes. These findings suggest that the combination of CD40L and IL2 gene-modified B-NHL cells will induce a cytotoxic immune response in vivo directed against unmodified tumor cells.

Synthesis and biological evaluation of certain 2'-deoxy-beta-D-ribo- and -beta-D-arabinofuranosyl nucleosides of purine-6-carboxamide and 4,8-diaminopyrimido[5,4-d]pyrimidine.

The key intermediate 9-(2,3,5,-tri-O-acetyl-beta-D-arabinofuranosyl)purine-6-carbonitrile (7) was synthesized in four steps from 9-beta-D-arabinofuranosylpurine-6-thione (3) via 6-(methylsulfonyl)-9-(2,3,5-tri-O-acetyl-beta-D-arabinofuranosyl)purine (6). Reaction of compound 7 with methanolic ammonia provided the rearranged compound 4-amino-8-(beta-D-arabinofuranosylamino)pyrimido[5,4-d]pyrimidine (8). Treatment of 7 with ammonium hydroxide and hydrogen peroxide provided 9-beta-D-arabinofuranosylpurine-6-carboxamide (9). Compound 7 was also treated with sodium hydrosulfide to yield 9-beta-D-arabinofuranosylpurine-6-thiocarboxamide (10). Similarly, 9-(2-deoxy-3,5-di-O-acetyl-beta-D-erythro-pentofuranosyl)purine 6-carbonitrile (17) was prepared from 6-chloro-9-(2-deoxy-beta-D-erythro-pentofluranosyl)purine (11) via 9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine-6-thione. Compound 17 was converted into 4-amino-8-[(2-deoxy-beta-D-erythro-pentofuranosyl)amino]pyrimido[5,4-d]pyrimidi ne (18) and 9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine-6-carboxamide (20), respectively. Compound 2 showed immunosuppressive activity and also inhibited the growth of L-1210 leukemia in mice. Arabinonucleoside analogues 8-10 were inactive when tested against RNA and DNA viruses in cell culture.

Synthesis and antiviral activity of certain 9-beta-D-ribofuranosylpurine-6-carboxamides.

To examine the structural parameters necessary for antiviral efficacy of certain purine nucleosides, several 9-beta-D-ribofuranosylpurine-6-carboxamides have been synthesized. Glycosylation of the Me3Si derivative of purine--6-carboxamide with protected ribofuranose in the presence of a Lewis acid gave the blocked nucleoside which on deprotection furnished 9-beta-D-ribofuranosyl-6-iodopurine with cyanide ion. Certain 2-amino- and 2-methyl-9-beta-D-ribofuranosylpurine-6-carboxamides have also been prepared. 8-Carbamoylguanosine (16) has been prepared by homolytic acylation of the parent nucleoside. These compounds were tested against several RNA and DNA viruses in cell culture. 9-beta-D-Ribofuranosylpurine-6-carboxamide (6a), the corresponding 6-thiocarboxamide (7b), and 4-amino-8-(beta-D-ribofuranosylamino)pyrimido[5,4-d]pyrimidine (8) showed significant in vitro antiviral activity at nontoxic dosage levels. 6a employed in the treatment of Rift Valley fever virus infected mice at 50 (mg/kg)/day gave a 55% survival rate on day 21 compared to a 30% survival in the controls.

Gene therapy for paediatric leukaemia.

Improvements in the chemotherapeutic and transplant regimens have had a significant impact in improving survival rates for paediatric leukaemia. However, there are still important problems to address including what options are available for patients with chemoresistant disease and what strategies are available to avoid the concerns regarding the toxicity associated with highly cytotoxic treatment regimens. Gene therapy and immunotherapy protocols hold great promise. Using gene transfer of a marker gene, a number of biological issues in the therapy of leukaemia have been addressed. For example, by gene marking autologous bone marrow grafts it has been possible to demonstrate that infused marrow contributes to relapse in acute and chronic myeloid leukaemias. In the allogeneic transplant setting, genetically modified T-cells have proven valuable for the prophylaxis and treatment of viral diseases and may have an important role in preventing or treating disease relapse. Gene transfer is also being used to modify tumour function, enhance immunogenicity, and confer drug-resistance to normal haematopoietic stem cells. With the continued scientific advancements in this field, gene therapy will almost certainly have a major impact on the treatment of paediatric leukaemia in the future.