Elastic nail fixation versus plate fixation of paediatric femoral fractures in school age patients - A retrospective observational study.

INTRODUCTION: The management of paediatric femoral fractures continues to spark debate in published literature, with poor quality evidence guiding current guidelines on the optimum treatment in children. Many centres report excellent results for both elastic intramedullary nailing and plate fixation of diaphyseal femoral fractures. This study aimed to investigate the outcomes of femoral fractures treated with elastic nail fixation versus those treated with plate fixation in a tertiary children's trauma unit, and discuss the advantages and disadvantages of each technique. MATERIALS AND METHODS: A retrospective review of all femoral fractures undergoing fixation at a level one paeditric trauma and tertiary referral unit, between 1st April 2009 and 30th April 2017, was performed.Clinical notes and radiographs were reviewed to determine patient demographics and injury, operative and hospital stay data. Radiological union, defined as bridging callus present on at least three out of four cortices on orthogonal radiographs, was determined at 12 weeks. Outcomes were determined using the Flynn Criteria. Patients were followed up for a minimum of 2 years. Data was statistically analysed, and a p value < 0.05 was considered significant. RESULTS: There were a total of 28 patients- 14 in each treatment group. Patients undergoing elastic nail fixation were significantly older than plate fixation (9.7 ± 1.9 Vs 7.7 ± 1.8; p = 0.008). A male preponderance was noted (21/28), with no difference between groups (10 Vs 11; p = 1.00). Plate fixation demonstrated a tendency towards shorter length of stay (6.3 ± 2.1 Vs 7.8 ± 3.0; p = 0.134), earlier radiological union at 12 weeks (14 Vs 10; p = 0.098), lower postoperative analgesia requirements (0.82 ± 0.45 Vs 1.12 ± 0.97; p = 0.200), and better outcomes, as determined by the Flynn criteria. CONCLUSIONS: In the authors opinion, plate fixation is a safe, effective alternative to elastic nail fixation with equivocal outcomes as determined by the Flynn Criteria. Plate fixation may offer advantages in shorter length of stay, reduced postoperative pain and earlier weightbearing. Further large scale, prospective research is required to determine whether these are borne out in practice.

Does reduced-intensity allogeneic transplantation confer a survival advantage to patients with poor prognosis chronic lymphocytic leukaemia? A case-control retrospective analysis.

BACKGROUND: Reduced-intensity conditioning (RIC) allogeneic haemopoietic cell transplantation (allo-HCT) is increasingly considered as a therapeutic option for younger patients with poor-risk chronic lymphocytic leukaemia (CLL). In this retrospective analysis, we assessed the outcomes of CLL patients undergoing RIC allo-HCT compared with a group of matched controls that were candidates for transplantation but did not have a suitable donor or refused the procedure. PATIENTS AND METHODS: Cases comprised 37 patients who underwent RIC allo-HCT. Haemopoietic cell grafts were harvested from HLA-matched siblings (27) and unrelated donors (7). Controls consisted of 43 patients from the same institutions who received conventional therapy only. Matching variables were age at diagnosis and time to first CLL-specific therapy. RESULTS: Both patient groups were well balanced in terms of cytogenetics by FISH, CD38 and ZAP-70 expression, and immunoglobulin heavy-chain variable region mutational status. Median overall survival was 113 months for HCT patients and 85 months for controls when calculated from time of diagnosis (P = 0.072) and 103 and 67 months, respectively, when calculated from time of first therapy (P = 0.041). CONCLUSION: RIC allo-HCT is a reasonable option for patients with high-risk CLL. However, these results require confirmation before the procedure can be recommended outside clinical trials.

Intrasubunit signal transduction by the aspartate chemoreceptor.

Receptors that transmit signals across cell membranes are typically composed of multiple subunits. To test whether subunit interactions are required for transmembrane signaling by the bacterial aspartate receptor, dimers were constructed with (i) two full-length subunits, (ii) one full-length subunit and one subunit lacking the cytoplasmic domain, or (iii) one full-length subunit and one subunit lacking both the cytoplasmic and the transmembrane domains. Methylation of the cytoplasmic domain of all three receptor constructs was stimulated by the binding of aspartate. These findings demonstrate that transmembrane signaling does not require interactions between cytoplasmic or transmembrane domains of adjacent subunits and suggest that signaling occurs via conformational changes transduced through a single subunit.

Three-dimensional structures of the ligand-binding domain of the bacterial aspartate receptor with and without a ligand.

The three-dimensional structure of an active, disulfide cross-linked dimer of the ligand-binding domain of the Salmonella typhimurium aspartate receptor and that of an aspartate complex have been determined by x-ray crystallographic methods at 2.4 and 2.0 angstrom (A) resolution, respectively. A single subunit is a four-alpha-helix bundle with two long amino-terminal and carboxyl-terminal helices and two shorter helices that form a cylinder 20 A in diameter and more than 70 A long. The two subunits in the disulfide-bonded dimer are related by a crystallographic twofold axis in the apo structure, but by a noncrystallographic twofold axis in the aspartate complex structure. The latter structure reveals that the ligand binding site is located more than 60 A from the presumed membrane surface and is at the interface of the two subunits. Aspartate binds between two alpha helices from one subunit and one alpha helix from the other in a highly charged pocket formed by three arginines. The comparison of the apo and aspartate complex structures shows only small structural changes in the individual subunits, except for one loop region that is disordered, but the subunits appear to change orientation relative to each other. The structures of the two forms of this protein provide a step toward understanding the mechanisms of transmembrane signaling.

Obstetric interventions for babies born before 28 weeks of gestation in Europe: results of the MOSAIC study.

OBJECTIVE: To describe obstetric intervention for extremely preterm births in ten European regions and assess its impact on mortality and short term morbidity. DESIGN: Prospective observational cohort study. SETTING: Ten regions from nine countries participating in the 'Models of Organising Access to Intensive Care for Very Preterm Babies in Europe' (MOSAIC) project. POPULATION: All births from 22 to 29 weeks of gestation (n = 4146) in 2003, excluding terminations of pregnancy. METHODS: Comparison of three obstetric interventions (antenatal corticosteroids, antenatal transfer and caesarean section for fetal indication) rates at 22-23, 24-25 and 26-27 weeks to that at 28-29 weeks and the association of the level of intervention with pregnancy outcome. MAIN OUTCOME MEASURES: Use of antenatal corticosteroids, antenatal transfer and caesarean section by two-week gestational age groups as well as a composite score of these three interventions. Outcomes included stillbirth, in-hospital mortality and intraventricular haemorrhage (IVH) grades III and IV and/or periventricular leucomalacia (PVL) and bronchopulmonary dysplasia (BPD). RESULTS: There were large differences between regions in interventions for births at 22-23 and 24-25 weeks. Differences were most pronounced at 24-25 weeks; in some regions these babies received the same care as babies of 28-29 weeks, whereas elsewhere levels of intervention were distinctly lower. Before 26 weeks and especially at 24-25 weeks, there was an association between the composite intervention score and mortality. No association was observed at 26-27 weeks. For survivors at 24-25 weeks, the intervention score was associated with higher rates of BPD, but not with IVH or PVL. CONCLUSIONS: There are large differences between European regions in obstetric practices at the lower limit of viability and these are related to outcome, especially at 24-25 weeks.

Assessment of fludarabine plus cyclophosphamide for patients with chronic lymphocytic leukaemia (the LRF CLL4 Trial): a randomised controlled trial.

BACKGROUND: Previous studies of patients with chronic lymphocytic leukaemia reported high response rates to fludarabine combined with cyclophosphamide. We aimed to establish whether this treatment combination provided greater survival benefit than did chlorambucil or fludarabine. METHODS: 777 patients with chronic lymphocytic leukaemia requiring treatment were randomly assigned to fludarabine (n=194) or fludarabine plus cyclophosphamide (196) for six courses, or chlorambucil (387) for 12 courses. The primary endpoint was overall survival, with secondary endpoints of response rates, progression-free survival, toxic effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number NCT 58585610. FINDINGS: There was no significant difference in overall survival between patients given fludarabine plus cyclophosphamide, fludarabine, or chlorambucil. Complete and overall response rates were better with fludarabine plus cyclophosphamide than with fludarabine (complete response rate 38%vs 15%, respectively; overall response rate 94%vs 80%, respectively; p<0.0001 for both comparisons), which were in turn better than with chlorambucil (complete response rate 7%, overall response rate 72%; p=0.006 and 0.04, respectively). Progression-free survival at 5 years was significantly better with fludarabine plus cyclophosphamide (36%) than with fludarabine (10%) or chlorambucil (10%; p<0.00005). Fludarabine plus cyclophosphamide was the best combination for all ages, including patients older than 70 years, and in prognostic groups defined by immunoglobulin heavy chain gene (V(H)) mutation status and cytogenetics, which were tested in 533 and 579 cases, respectively. Patients had more neutropenia and days in hospital with fludarabine plus cyclophosphamide, or fludarabine, than with chlorambucil. There was less haemolytic anaemia with fludarabine plus cyclophosphamide (5%) than with fludarabine (11%) or chlorambucil (12%). Quality of life was better for responders, but preliminary analyses showed no significant difference between treatments. A meta-analysis of these data and those of two published phase III trials showed a consistent benefit for the fludarabine plus cyclophosphamide regimen in terms of progression-free survival. INTERPRETATION: Fludarabine plus cyclophosphamide should now become the standard treatment for chronic lymphocytic leukaemia and the basis for new protocols that incorporate monoclonal antibodies.

Superiority of reduced-intensity allogeneic transplantation over conventional treatment for relapse of Hodgkin's lymphoma following autologous stem cell transplantation.

This study compares outcome of reduced-intensity conditioned transplant (RIT) with outcome of conventional non-transplant therapy in patients with Hodgkin's lymphoma relapsing following autograft. There were 72 patients in two groups who had relapsed, and received salvage therapy with chemotherapy+/-radiotherapy. One group (n=38) then underwent alemtuzumab-containing RIT. The second group-historical controls (n=34), relapsing before the advent of RIT-had no further high-dose therapy. This group was required to respond to salvage therapy and live for over 12 months post-relapse, demonstrating potential eligibility for RIT, had this been available. Overall survival (OS) from diagnosis was superior following RIT (48% at 10 years versus 15%; P=0.0014), as was survival from autograft (65% at 5 years versus 15%; P< or =0.0001). For the RIT group, OS at 5 years from allograft was 51%, and in chemoresponsive patients was 58%, with current progression-free survival of 42%. Responses were seen in 8 of 15 patients receiving donor lymphocyte infusions (DLI) for relapse/progression, with durable remission in five patients at median follow-up from DLI of 45 months (28-55). These data demonstrate the potential efficacy of RIT in heavily pre-treated patients whose outlook with conventional therapy is dismal, and provide evidence of a clinically relevant graft-versus-lymphoma effect.

Indications for allogeneic stem cell transplantation in chronic lymphocytic leukemia: the EBMT transplant consensus.

The aim of this project was to identify situations where allogeneic stem cell transplantation (allo-SCT) might be considered as a preferred treatment option for patients with B-cell chronic lymphocytic leukemia (CLL). Based on a MEDLINE search and additional sources, a consented proposal was drafted, refined and approved upon final discussion by an international expert panel. Key elements of the consensus are (1) allo-SCT is a procedure with evidence-based efficacy in poor-risk CLL; (2) although definition of 'poor-risk CLL' requires further investigation, allo-SCT is a reasonable treatment option for younger patients with (i) non-response or early relapse (within 12 months) after purine analogues, (ii) relapse within 24 months after having achieved a response with purine-analogue-based combination therapy or autologous transplantation, and (iii) patients with p53 abnormalities requiring treatment; and (3) optimum transplant strategies may vary according to distinct clinical situations and should be defined in prospective trials. This is the first attempt to define standard indications for allo-SCT in CLL. Nevertheless, whenever possible, allo-SCT should be performed within disease-specific prospective clinical protocols in order to continuously refine transplant indications according to new developments in risk assessment and treatment of CLL.

Results of the randomized phase IIB ARCTIC trial of low-dose rituximab in previously untreated CLL.

ARCTIC was a multicenter, randomized-controlled, open, phase IIB non-inferiority trial in previously untreated chronic lymphocytic leukemia (CLL). Conventional frontline therapy in fit patients is fludarabine, cyclophosphamide and rituximab (FCR). The trial hypothesized that including mitoxantrone with low-dose rituximab (FCM-miniR) would be non-inferior to FCR. A total of 200 patients were recruited to assess the primary end point of complete remission (CR) rates according to IWCLL criteria. Secondary end points were progression-free survival (PFS), overall survival (OS), overall response rate, minimal residual disease (MRD) negativity, safety and cost-effectiveness. The trial closed following a pre-planned interim analysis. At final analysis, CR rates were 76 FCR vs 55% FCM-miniR (adjusted odds ratio: 0.37; 95% confidence interval: 0.19-0.73). MRD-negativity rates were 54 FCR vs 44% FCM-miniR. More participants experienced serious adverse reactions with FCM-miniR (49%) compared to FCR (41%). There are no significant differences between the treatment groups for PFS and OS. FCM-miniR is not expected to be cost-effective over a lifetime horizon. In summary, FCM-miniR is less well tolerated than FCR with an inferior response and MRD-negativity rate and increased toxicity, and will not be taken forward into a confirmatory trial. The trial demonstrated that oral FCR yields high response rates compared to historical series with intravenous chemotherapy.

A comparison of clofarabine with ara-C, each in combination with daunorubicin as induction treatment in older patients with acute myeloid leukaemia.

The study was designed to compare clofarabine plus daunorubicin vs daunorubicin/ara-C in older patients with acute myeloid leukaemia (AML) or high-risk myelodysplastic syndrome (MDS). Eight hundred and six untreated patients in the UK NCRI AML16 trial with AML/high-risk MDS (median age, 67 years; range 56-84) and normal serum creatinine were randomised to two courses of induction chemotherapy with either daunorubicin/ara-C (DA) or daunorubicin/clofarabine (DClo). Patients were also included in additional randomisations; ± one dose of gemtuzumab ozogamicin in course 1; 2v3 courses and ± azacitidine maintenance. The primary end point was overall survival. The overall response rate was 69% (complete remission (CR) 60%; CRi 9%), with no difference between DA (71%) and DClo (66%). There was no difference in 30-/60-day mortality or toxicity: significantly more supportive care was required in the DA arm even though platelet and neutrophil recovery was significantly slower with DClo. There were no differences in cumulative incidence of relapse (74% vs 68%; hazard ratio (HR) 0.93 (0.77-1.14), P=0.5); survival from relapse (7% vs 9%; HR 0.96 (0.77-1.19), P=0.7); relapse-free (31% vs 32%; HR 1.02 (0.83-1.24), P=0.9) or overall survival (23% vs 22%; HR 1.08 (0.93-1.26), P=0.3). Clofarabine 20 mg/m2 given for 5 days with daunorubicin is not superior to ara-C+daunorubicin as induction for older patients with AML/high-risk MDS.

Reduced-intensity conditioning lowers treatment-related mortality of allogeneic stem cell transplantation for chronic lymphocytic leukemia: a population-matched analysis.

To elucidate whether reduced-intensity conditioning (RIC) decreases treatment-related mortality (TRM) after allogeneic stem cell transplantation (allo-SCT) for chronic lymphocytic leukemia (CLL), we retrospectively compared 73 RIC cases from a recent EBMT survey with 82 patients from the EBMT database who had undergone standard myeloablative conditioning (MC) for CLL during the same time period. The two populations were matched by adjusting the primary risk factor, the conditioning regimen, in a series of Cox models for age, sex, donor type, remission status at transplant and analyzed for its effect on TRM, relapse incidence, event-free (EFS) and overall survival (OS). After adjustment, a significant reduction of TRM became evident for the RIC population (hazard ratio (HR) 0.4 (95% confidence interval 0.18-0.9); P=0.03). On the other hand, RIC was associated with an increased relapse incidence (HR 2.65 (0.98-7.12); P=0.054). There was no significant difference between RIC and MC in terms of EFS (HR 0.69 (0.38-1.25); P=0.22) and OS (HR 0.65 (0.33-1.28); P=0.21). We conclude that RIC appears to favorably influence TRM after allo-SCT for CLL. This observation, as well as possible detrimental effects of RIC on relapse risk, should be confirmed by prospective studies.

Single versus double volume exchange transfusion in jaundiced newborn infants.

BACKGROUND: Double volume exchange transfusion is commonly used in newborns with severe jaundice in order to prevent kernicterus and other toxicity related to hyperbilirubinemia. Most commonly, exchange transfusions are used in infants with rhesus hemolytic disease. OBJECTIVES: To compare the effectiveness of single volume exchange transfusion (SVET) with that of double volume exchange transfusion (DVET) in producing survival without disability and reducing bilirubin levels in newborn infants with severe jaundice. SEARCH STRATEGY: MEDLINE, EMBASE (Excerpta Medica online), The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), SCISEARCH (Science Citation Index), Reference lists from the articles identified in the search of the databases, and from review articles were searched through March 2006. Personal communication with experts in the field was used to identify unpublished data. SELECTION CRITERIA: All Randomised and quasi randomised control trials comparing single volume and double volume exchange transfusions in jaundiced newborn infants were included. DATA COLLECTION AND ANALYSIS: Safety and efficacy of single and double volume exchange compared with regards to long term neurodevelopment, reduction in bilirubin levels and other complications during exchange transfusion. Data was evaluated separately with regards to the cause of jaundice. Relative risk (RR) and weighted mean difference (WMD) were calculated for dichotomous and continuous variables respectively. 95% confidence intervals were used and a fixed effects model was assumed. MAIN RESULTS: Only one study fulfilled the criteria (Amato 1988). 20 full term babies requiring exchange transfusion for hemolytic jaundice due to ABO incompatibility were randomly allocated to receive single or double volume exchange transfusion. Base line characteristics of both groups were similar with regards to birth weight 3260 (SD 390) g vs. 3350 SD (410) g, gestational age 39 (SD 1) week vs. 40 (SD 0.8) week, immediate pre exchange bilirubin level 199 (SD 33) micromol/L vs. 216 (SD 55) micromol/L. Both groups were treated equally apart from the volume of blood used for exchange transfusion. Total bilirubin levels immediately after exchange transfusion were not significantly different in either group. No long term neurodevelopmental outcome was examined in this study. AUTHORS' CONCLUSIONS: There was insufficient evidence to support or refute the use of single volume exchange transfusion as opposed to double volume exchange transfusion in jaundiced newborns. A change from the current practice of double volume exchange transfusions for severe jaundice in newborns infant, cannot be recommended on current evidence.

Electrolyzed oxidizing anode water as a sanitizer for use in abattoirs.

The effectiveness of electrolyzed oxidizing anode (EOA) water (oxidation-reduction potential, 1,120 mV; pH 2.0) as a sanitizer for use in abattoirs was compared with the iodophor (IOD) Mikroklene (25 ppm), a sanitizer approved for use by regulatory authorities in Canada and the United States. A total of 240 swab (100 cm2) samples were obtained from 4 sites on the kill floor and 16 sites in the secondary processing areas, during two visits within a 4-week period to each of three meat packing plants, processing < or =50 animals per week. Swabs were obtained 12 h after the application of IOD and EOA and were analyzed for the presence of total aerobic bacteria, total coliforms, and total Escherichia coli. Total aerobic bacteria (log CFU/ 100 cm2) recovered from the 20 sample sites were lower (P < 0.0001) in EOA as compared with IOD (2.94 +/- 0.12 versus 3.75 +/- 0.12, respectively). Plant A was 1.5 times more likely (P < 0.0001) to have a sampling site positive for the presence of coliforms and E. coli than plants B and C. There was no difference (P > 0.05) between treatment IOD or EOA in the likelihood of obtaining a positive sample for the presence of total coliforms or E. coli among the three plants. When the kill floor and secondary processing areas are compared, the likelihood of obtaining a sample positive for coliforms or E. coli was similar (P > or = 0.05). Results indicate that EOA was more effective than IOD in reducing populations of total aerobic bacteria on equipment surfaces in the three meat packing plants studied. Because the likelihood of obtaining a positive sample for coliforms or E. coli in EOA as compared with IOD was similar, EOA may be a suitable alternative or complement to IOD as a sanitizer in small- to medium-sized abattoirs. Additional research is required to further evaluate the effectiveness of EOA to sanitize processing equipment on the basis of subsequent isolation of aerobes, coliforms, and E. coli from meat products.

hMYH cell cycle-dependent expression, subcellular localization and association with replication foci: evidence suggesting replication-coupled repair of adenine:8-oxoguanine mispairs.

The human MutY homolog, hMYH, is an adenine-specific DNA glycosylase that removes adenines or 2-hydroxyadenines mispaired with guanines or 8-oxoguanines. In order to prevent mutations, this activity must be directed to the newly synthesized strand and not the template strand during DNA synthesis. The subcellular localization and expression of hMYH has been studied in serum-stimulated, proliferating MRC5 cells. Using specific antibodies, we demonstrate that endogenous hMYH protein localized both to nuclei and mitochondria. hMYH in the nuclei is distinctly distributed and co-localized with BrdU at replication foci and with proliferating cell nuclear antigen (PCNA). The levels of hMYH in the nucleus increased 3- to 4-fold during progression of the cell cycle and reached maximum levels in S phase compared to early G(1). Similar results were obtained for PCNA, while there were no notable changes in expression of 8-oxoguanine glycosylase or the human MutT homolog, MTH1, throughout the cell cycle. The cell cycle-dependent expression and localization of hMYH at sites of DNA replication suggest a role for this glycosylase in immediate post-replication DNA base excision repair.

Successful treatment of acute myeloid leukemia beyond first remission with autologous bone marrow transplantation using busulfan/cyclophosphamide and unpurged marrow: the British autograft group experience.

The results in 34 adult patients with acute myeloid leukemia (AML) who have undergone autologous bone marrow transplantation (ABMT) using busulfan and cyclophosphamide (Bu/Cy) in 12 United Kingdom (UK) centers have been analyzed. There were 19 females and 15 males; median age was 40 years (range, 21 to 62 years). Nine patients were in first relapse; 25 were in second remission. The median time of first remission for the whole group was 11.5 months (range, 1 to 56 months). All the patients in first relapse and six patients in second remission received first remission marrow. The leukemia-free survival (LFS) for the patients in first relapse was 33%, with a median follow-up of 20 months. The LFS for the patients in second remission was 48% with a median follow-up of 26 months. The length of second remission exceeds the length of first remission in 14 patients. Considerable toxicity with hemorrhagic cystitis (four patients; none fatal), venoocclusive disease (four patients; one fatal), pneumonitis (four patients; one fatal), intracranial hemorrhage (two patients; two fatal) has occurred. There have been four procedure-related deaths (12%). Hematologic recovery was satisfactory for neutrophils (median time to 0.5 x 10(9)/L, 22 days [range, 11 to 101 days]), but very slow for platelets (median time to 50 x 10(9)/L, 62 days [range, 15 to 1,080 days]). This study suggests that the use of Bu/Cy with ABMT for patients beyond first remission in AML compares favorably with chemotherapy, and although the procedure-related mortality is acceptable, it is associated with protracted platelet recovery.

Engraftment and molecular monitoring of CD34+ peripheral-blood stem-cell transplants for follicular lymphoma: a pilot study.

PURPOSE: A pilot study to validate the use of CD34+ selection (Ceprate SC) of blood stem-cell collection in patients with advanced follicular lymphoma receiving myeloablative chemoradiotherapy. PATIENTS AND METHODS: Seventeen patients were entered onto the protocol. Thirteen of 17 patients have undergone transplantation; the median age is 42.5 years (range, 33 to 51), seven of 13 are stage IVB, two stage IVA, three stage IIIB, and one stage IIB. All except two patients were treated after first or subsequent relapses after receiving cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy to achieve a good partial (six of 13) or complete (seven of 13) response before stem-cell mobilization with cyclophosphamide 3 g/m2 and filgrastim 300 microg once daily. RESULTS: Eleven of 13 patients had a detectable t(14;18) by nested polymerase chain reaction (PCR). Median CD34+ count before selection was 2.9 x 10(6)/kg (range, 1.17 to 11.3) and after CD34+ selection was 1.54 x 10(6)/kg (range, 0.88 to 7.6) with a median CD34+ yield of 62.4% (range, 17% to 95%) and purity of 60% (range, 39.3% to 73%). Of the 11 patients known to have t(14;18), 10 had PCR-detectable contamination of stem-cell harvests that became PCR negative in six of the 10 after CD34+ selection. Engraftment was rapid with a median day to absolute neutrophil count (ANC) greater than 0.5 x 10(9)/L of 13 days (range, 11 to 21) and platelet count greater than 20 x 10(9)/L of 14 days (range, 10 to 44). With a median follow-up duration of 15 months, three patients have remained persistently PCR-positive, two of whom received PCR-positive stem cells. Two have relapsed. Of the seven patients who received PCR-negative stem cells, five have had no PCR-detectable disease in posttransplant bone marrow samples. CONCLUSION: Longer follow-up duration is required to determine the significance of these findings, but we have confirmed the feasibility of CD34+ selected cells to deplete peripheral-blood stem cells of tumor cells from patients undergoing high-dose therapy for follicular lymphoma.

Crystallization and preliminary X-ray diffraction study of the ligand-binding domain of the bacterial chemotaxis-mediating aspartate receptor of Salmonella typhimurium.

The periplasmic domain of the aspartate chemotaxis receptor from Salmonella typhimurium has been crystallized in the presence and absence of bound aspartate. Both crystal forms were grown by precipitation with lithium sulfate and diffract to 1.8 A resolution. The aspartate receptor structure is believed to be prototypical of a large class of receptors including those for polypeptide growth factor hormones as well as those for small chemotaxis-affector molecules such as aspartate and serine.

Refined structures of the ligand-binding domain of the aspartate receptor from Salmonella typhimurium.

The aspartate receptor is a transmembrane-signalling protein that mediates chemotaxis behaviour in bacteria. Aspartate receptors in Salmonella typhimurium and Escherichia coli exist as dimers of two subunits in the presence as well as in the absence of aspartate. We have previously reported the three-dimensional structures of the external ligand-binding domain of the S. typhimurium aspartate receptor with and without bound aspartate. The external or periplasmic region of the aspartate receptor is a dimer of four-alpha-helical bundle subunits; a single aspartate molecule binds to one of two sites residing at the subunit interface, increasing the affinity of the subunits for one another. Here we report the results of a detailed analysis of the aspartate receptor ligand-binding domain structure (residues 25 to 188). The dimer interface between the twofold related subunits consists primarily of contacts mediated by the side-chains of the N-terminal helix of each four-alpha-helical bundle subunit. The N-terminal helices pack approximately 20 degrees from parallel as an approximate coiled-coil super-secondary structure. We have refined aspartate receptor ligand-binding domain structures in the presence and in the absence of a bound aromatic compound, 1,10-phenanthroline, to 2.2 A and 2.3 A resolution, respectively, as well as crystal structures in the presence of specifically bound Au(I), Hg(II) and Pt(IV) complex ions at 2.4 A, 3.0 A and 3.3 A resolution, respectively. The possible biological relevance of the aromatic ligand-binding site and the metal ion-binding sites is discussed. The dimer of four-alpha-helical bundle subunits composing the periplasmic region of the S. typhimurium aspartate receptor provides a basis for understanding the results of mutational analyses performed on related chemotaxis transmembrane receptors. The crystal structure analysis provides an explanation for the way in which mutations in the E. coli aspartate receptor affect its binding to the periplasmic maltose-binding protein and how mutations in the more distantly related E. coli Trg chemotaxis receptor affect its binding to the periplasmic ribose and glucose-galactose binding proteins.

Management of chronic myeloid leukaemia in relapse following donor lymphocyte infusion induced remission: a retrospective study of the Clinical Trials Committee of the British Society of Blood & Marrow Transplantation (BSBMT).

Donor lymphocyte infusion (DLI) can restore remission in a high percentage of patients with chronic myeloid leukaemia (CML) who relapse after allogeneic stem cell transplant (SCT). Subsequent relapses after a DLI-induced remission do occur and the optimal management of these patients is not defined. A retrospective study of the practice of UK transplant centres was conducted. In all, 13 patients from seven centres were identified: all were treated for relapse post allogeneic SCT with DLI and achieved either a complete cytogenetic (n=5) or molecular (n=8) remission. All patients subsequently had a second relapse, at molecular (n=7), cytogenetic (n=4) and haematological (n=2) levels. Further DLI was used in the treatment of 11 patients, imatinib mesylate in three and chemotherapy in two. The two patients with haematological relapse died of blastic disease. The remaining 11 patients achieved either a complete cytogenetic (n=2) or molecular (n=9) remission. Nine patients remain in molecular remission at a median follow-up of 29 months, seven of whom had received DLI alone as treatment for second relapse, one DLI plus imatinib and one imatinib alone. Toxicity following DLI for second relapse was low. Longer follow-up will be required to see if these second DLI-induced remissions will be durable.

Treatment-related mortality and graft-versus-leukemia activity after allogeneic stem cell transplantation for chronic lymphocytic leukemia using intensity-reduced conditioning.

Allogeneic stem cell transplantation (SCT) using reduced-intensity conditioning (RIC) has potential to be a promising treatment of aggressive chronic lymphocytic leukemia (CLL). Since available clinical data obtained with this novel approach are very limited, we have performed a survey on this issue. Data of 77 patients were collected from 29 European Group for Blood and Marrow Transplantation centers. Median age was 54 (30-66) years, and the median number of previous chemotherapy regimens was 3 (0-8). HLA-identical sibling donors were used in 81% of the cases. Moderate conditioning regimens (mainly low-dose total body irradiation (TBI) or fludarabine-cyclophosphamide combinations) were administered to 56% of the patients, whereas the remainder received more intense conditioning consisting of fludarabine-busulfan or high-dose melphalan combinations. In 40% of the patients, in vivo T-cell depletion (TCD) with anti-thymocyte globulin or CAMPATH-1H was part of the conditioning regimen. Cumulative treatment-related mortality (TRM) was 18% (95% CI 9; 27) after 12 months. Complete chimerism as well as best response was not achieved immediately post-transplant but took a median of 3 months to develop. The 2-year probability of relapse was 31% (95% CI 18; 44), with no event occurring later than 12 months post transplant in the absence of TCD. With one exception, relapses were not observed after onset of chronic graft-versus-host disease. Event-free and overall survival at 24 months were 56% (95% CI 43; 69) and 72% (95% CI 61; 83), respectively. The median follow-up was 18 (1-44) months. Donor lymphocyte infusions or secondary transplants were performed in 19 patients with insufficient disease control and/or incomplete donor chimerism post-transplant, leading to a response in seven patients (37%). Preliminary multivariate analysis identified less than PR at transplant (hazard ratio (HR) 3.5; P&<0.01) and alternative donor (HR 3.1; P=0.02) as significant risk factors for relapse, whereas number of previous regimens >2 (HR 5.4; P=0.03), TBI (HR 2.5; P=0.05), and alternative donor (HR 2.3; P=0.08) were risk factors for survival. We conclude that RIC might favorably influence the outcome after allogeneic SCT for CLL by reducing TRM while preserving graft-versus leukemia activity.