PROSPER: a randomised comparison of surgical treatments for rectal prolapse.

AIM: Rectal prolapse is a profoundly disabling condition, occurring mainly in elderly and parous women. There is no accepted standard surgical treatment, with previous studies limited in methodological quality and size. PROSPER aimed to address these deficiencies by comparing the relative merits of different procedures. METHOD: In a pragmatic, factorial (2 × 2) design trial, patients could be randomised between abdominal and perineal surgery (i), and suture vs resection rectopexy for those receiving an abdominal procedure (ii) or Altemeier's vs Delorme's for those receiving a perineal procedure (iii). Primary outcome measures were recurrence of the prolapse, incontinence, bowel function and quality of life scores (Vaizey, bowel thermometer and EQ-5D) measured up to 3 years. RESULTS: Two hundred and ninety-three patients were recruited: 49 were randomised between surgical approaches (i); 78 between abdominal procedures (ii); and 213 between perineal procedures (iii). Recurrence rates were higher than anticipated, but not significantly different in any comparison: Altemeier's vs Delorme's 24/102 (24%) and 31/99 (31%) [hazard ratio (HR) 0.81; 95% CI 0.47, 1.38; P = 0.4]; resection vs suture rectopexy 4/32 (13%) and 9/35 (26%) (HR 0.45; 95% CI 0.14, 1.46; P = 0.2); perineal vs abdominal 5/25 (20%) and 5/19 (26%) (HR 0.83; 95% CI 0.24, 2.86; P = 0.8). Vaizey, bowel thermometer and EQ-5D scores were not significantly different in any of the comparisons. CONCLUSION: No significant differences were seen in any of the randomised comparisons, although substantial improvements from baseline in quality of life were noted following all procedures.

Intrapartum tests for group B streptococcus: accuracy and acceptability of screening.

OBJECTIVE: To assess the accuracy and acceptability of polymerase chain reaction (PCR) and optical immunoassay (OIA) tests for the detection of maternal group B streptococcus (GBS) colonisation during labour, comparing their performance with the current UK policy of risk factor-based screening. DESIGN: Diagnostic test accuracy study. SETTING AND POPULATION: Fourteen hundred women in labour at two large UK maternity units provided vaginal and rectal swabs for testing. METHODS: The PCR and OIA index tests were compared with the reference standard of selective enriched culture, assessed blind to index tests. Factors influencing neonatal GBS colonisation were assessed using multiple logistic regression, adjusting for antibiotic use. The acceptability of testing to participants was evaluated through a structured questionnaire administered after delivery. MAIN OUTCOME MEASURES: The sensitivity and specificity of PCR, OIA and risk factor-based screening. RESULTS: Maternal GBS colonisation was 21% (19-24%) by combined vaginal and rectal swab enriched culture. PCR test of either vaginal or rectal swabs was more sensitive (84% [79-88%] versus 72% [65-77%]) and specific (87% [85-89%] versus 57% [53-60%]) than OIA (P < 0.001), and far more sensitive (84 versus 30% [25-35%]) and specific (87 versus 80% [77-82%]) than risk factor-based screening (P < 0.001). Maternal antibiotics (odds ratio, 0.22 [0.07-0.62]; P = 0.004) and a positive PCR test (odds ratio, 29.4 [15.8-54.8]; P < 0.001) were strongly related to neonatal GBS colonisation, whereas risk factors were not (odds ratio, 1.44 [0.80-2.62]; P = 0.2). CONCLUSION: Intrapartum PCR screening is a more accurate predictor of maternal and neonatal GBS colonisation than is OIA or risk factor-based screening, and is acceptable to women.

Intra-articular injection of tumor necrosis factor-alpha in the rat: an acute and reversible in vivo model of cartilage proteoglycan degradation.

OBJECTIVE: To develop an in vivo model for rapid assessment of cartilage aggrecan degradation and its pharmacological modulation. DESIGN: Tumor necrosis factor-alpha (TNFalpha) was injected intra-articularly (IA) in rat knees and aggrecan degradation was monitored at various times following challenge. Articular cartilage was assessed for aggrecan content by Safranin O staining and by immunohistochemistry for the NITEGE epitope. Synovial fluids (SFs) were analyzed for sulfated glycosaminoglycans (GAGs) using the dimethylmethylene blue dye assay and for aggrecan fragments generated by specific cleavage at aggrecanase-sensitive sites by Western blot analysis with neoepitope antibodies. Indomethacin, dexamethasone, and an aggrecanase inhibitor were evaluated for their ability to modulate TNFalpha-induced proteoglycan degradation in vivo. RESULTS: (1) IA injection of TNFalpha in the knee joint of rats resulted in transient aggrecan degradation and release of aggrecanase-generated aggrecan fragments from the articular cartilage into the SF; (2) a correlation was observed between histologically assessed depletion of aggrecan from the articular cartilage and the appearance of specific neoepitopes in the SF; (3) aggrecan degradation was inhibited by an aggrecanase inhibitor as well as by dexamethasone, but not by the non-steroidal anti-inflammatory drug (NSAID), indomethacin. CONCLUSION: TNFalpha injection in the knee joints of rats results in rapid transient cartilage proteoglycan degradation, mediated by cleavage at the aggrecanase sites. Biomarker read-out of specific neoepitopes in the SF enables the use of this mechanism-based model for rapid evaluation of aggrecanase-mediated aggrecan degradation in vivo.

Venus: new microwave measurements show no atmospheric water vapor.

Two sets of passive radio observations of Venus-measurements of the spectrum of the disk temperature near the 1-centimeter wavelength, and interferometric measurements of the planetary limb darkening at the 1.35-centimeter water vapor resonance-show no evidence of water vapor in the lower atmosphere of Venus. The upper limit of 2 x 10(-3) for the mixing ratio of water vapor is substantially less than the amounts derived from the Venera space probes (0.5 x 10(-2) to 2.5 x 10(-2)). This amount of water vapor cannot produce dense clouds, and it is doubtful that it may contribute significantly to a greenhouse effect.

Aspirin in Alzheimer's disease (AD2000): a randomised open-label trial.

BACKGROUND: Cardiovascular risk factors and a history of vascular disease can increase the risk of Alzheimer's disease (AD). AD is less common in aspirin users than non-users, and there are plausible biological mechanisms whereby aspirin might slow the progression of either vascular or Alzheimer-type pathology. We assessed the benefits of aspirin in patients with AD. METHODS: 310 community-resident patients who had AD and who had no potential indication or definite contraindication for aspirin were randomly assigned to receive open-label aspirin (n=156; one 75-mg enteric-coated tablet per day, to continue indefinitely) or to avoid aspirin (n=154). Primary outcome measures were cognition (assessed with the mini-mental state examination [MMSE]) and functional ability (assessed with the Bristol activities of daily living scale [BADLS]). Secondary outcomes were time to formal domiciliary or institutional care, progress of disability, behavioural symptoms, caregiver wellbeing, and care time. Patients were assessed at 12-week intervals in the first year and once each year thereafter. Analysis of the primary outcome measures was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN96337233. FINDINGS: Patients had a median age of 75 years; 156 patients had mild AD, 154 had moderate AD, and 18 had concomitant vascular dementia. Over the 3 years after randomisation, in patients who took aspirin, mean MMSE score was 0.10 points higher (95% CI -0.37 to 0.57; p=0.7) and mean BADLS score was 0.62 points lower (-1.37 to 0.13; p=0.11) than in patients assigned to aspirin avoidance. There were no obvious differences between the groups in any other outcome measurements. 13 (8%) patients on aspirin and two (1%) patients in the control group had bleeds that led to admission to hospital (relative risk=4.4, 95% CI 1.5-12.8; p=0.007); three (2%) patients in the aspirin group had fatal cerebral bleeds. INTERPRETATION: Although aspirin is commonly used in dementia, in patients with typical AD 2 years of treatment with low-dose aspirin has no worthwhile benefit and increases the risk of serious bleeds.

South Pole Telescope optics.

The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber.

Continuous versus interrupted sutures for repair of episiotomy or second degree tears.

BACKGROUND: Millions of women worldwide undergo perineal suturing after childbirth and the type of repair may have an impact on pain and healing. For more than 70 years, researchers have been suggesting that continuous non-locking suture techniques for repair of the vagina, perineal muscles and skin are associated with less perineal pain than traditional interrupted methods. OBJECTIVES: To assess the effects of continuous versus interrupted absorbable sutures for repair of episiotomy and second degree perineal tears following childbirth. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2007). SELECTION CRITERIA: Randomised trials comparing continuous versus interrupted sutures for repair of episiotomy and second-degree tears after vaginal delivery. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trial quality. Two of the three authors independently extracted data and a third author checked them. We contacted study authors for additional information. MAIN RESULTS: Seven studies, involving 3822 women at point of entry, from four countries, have been included. The trials were heterogeneous in respect of operator skill and training. Meta-analysis showed that continuous suture techniques compared with interrupted sutures for perineal closure (all layers or perineal skin only) are associated with less pain for up to 10 days postpartum (relative risk (RR) 0.70, 95% confidence interval 0.64 to 0.76). Subgroup analysis showed that there is a greater reduction in pain when continuous suturing techniques are used for all layers (RR 0.65, 95% CI 0.60 to 0.71). There was an overall reduction in analgesia use associated with the continuous subcutaneous technique versus interrupted stitches for repair of perineal skin (RR 0.70, 95% CI 0.58 to 0.84). Subgroup analysis showed some evidence of reduction in dyspareunia experienced by participants in the groups that had continuous suturing for all layers (RR 0.83, 95% CI 0.70 to 0.98). There was also a reduction in suture removal in the continuous suturing groups versus interrupted (RR 0.54, 95% CI 0.45 to 0.65), but no significant differences were seen in the need for re-suturing of wounds or long-term pain. AUTHORS' CONCLUSIONS: The continuous suturing techniques for perineal closure, compared to interrupted methods, are associated with less short-term pain. Moreover, if the continuous technique is used for all layers (vagina, perineal muscles and skin) compared to perineal skin only, the reduction in pain is even greater.

Expression of CD33 is a predictive factor for effect of gemtuzumab ozogamicin at different doses in adult acute myeloid leukaemia.

It remains unclear in adult acute myeloid leukaemia (AML) whether leukaemic expression of CD33, the target antigen for gemtuzumab ozogamicin (GO), adds prognostic information on GO effectiveness at different doses. CD33 expression quantified in 1583 patients recruited to UK-NCRI-AML17 (younger adults) and UK-NCRI-AML16 (older adults) trials was correlated with clinical outcomes and benefit from GO including a dose randomisation. CD33 expression associated with genetic subgroups, including lower levels in both adverse karyotype and core-binding factor (CBF)-AML, but was not independently prognostic. When comparing GO versus no GO (n=393, CBF-AMLs excluded) by stratified subgroup-adjusted analysis, patients with lowest quartile (Q1) %CD33-positivity had no benefit from GO (relapse risk, HR 2.41 (1.27-4.56), P=0.009 for trend; overall survival, HR 1.52 (0.92-2.52)). However, from the dose randomisation (NCRI-AML17, n=464, CBF-AMLs included), 6 mg/m2 GO only had a relapse benefit without increased early mortality in CD33-low (Q1) patients (relapse risk HR 0.64 (0.36-1.12) versus 1.70 (0.99-2.92) for CD33-high, P=0.007 for trend). Thus CD33 expression is a predictive factor for GO effect in adult AML; although GO does not appear to benefit the non-CBF AML patients with lowest CD33 expression a higher GO dose may be more effective for CD33-low but not CD33-high younger adults.

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.

Characteristics and outcome of patients with therapy-related acute promyelocytic leukemia front-line treated with or without arsenic trioxide.

Therapy-related acute promyelocytic leukemia (t-APL) is relatively rare, with limited data on outcome after treatment with arsenic trioxide (ATO) compared to standard intensive chemotherapy (CTX). We evaluated 103 adult t-APL patients undergoing treatment with all-trans retinoic acid (ATRA) alone (n=7) or in combination with ATO (n=24), CTX (n=53), or both (n=19). Complete remissions were achieved after induction therapy in 57% with ATRA, 100% with ATO/ATRA, 78% with CTX/ATRA, and 95% with CTX/ATO/ATRA. Early death rates were 43% for ATRA, 0% for ATO/ATRA, 12% for CTX/ATRA and 5% for CTX/ATO/ATRA. Three patients relapsed, two developed therapy-related acute myeloid leukemia and 13 died in remission including seven patients with recurrence of the prior malignancy. Median follow-up for survival was 3.7 years. None of the patients treated with ATRA alone survived beyond one year. Event-free survival was significantly higher after ATO-based therapy (95%, 95% CI, 82-99%) as compared to CTX/ATRA (78%, 95% CI, 64-87%; P=0.042), if deaths due to recurrence of the prior malignancy were censored. The estimated 2-year overall survival in intensively treated patients was 88% (95% CI, 80-93%) without difference according to treatment (P=0.47). ATO when added to ATRA or CTX/ATRA is feasible and leads to better outcomes as compared to CTX/ATRA in t-APL.

Treatment strategy and long-term results in paediatric patients treated in consecutive UK AML trials.

Between 1988 and 2002, 758 children with acute myeloid leukaemia (AML) were treated on Medical Research Council (MRC) AML 10 and AML 12. MRC AML 10 tested the role of bone marrow transplantation following four blocks of intensive chemotherapy and found that while both allogeneic bone marrow transplant (allo-BMT) and autologous bone marrow transplant (A-BMT) significantly reduced the relapse risk (RR), this did not translate into a significant improvement in overall survival (OS). A risk group stratification based on cytogenetics and response to the first course of chemotherapy derived from MRC AML 10 was used to deliver risk-directed therapy in MRC AML 12. Allo-BMT was limited to standard and poor risk patients and A-BMT was not employed. Instead, the benefit of an additional block of treatment was tested by randomising children to receive either four or five blocks of treatment in total. While the results of MRC AML 12 remain immature, there appears to be no survival advantage for a fifth course of treatment. The 5 year OS, disease-free survival (DFS), event-free survival (EFS) and RR in MRC AML 12 are 66, 61, 56 and 35%, respectively; at present superior to MRC AML 10, which had a 5-year OS, DFS, EFS and RR of 58, 53, 49 and 42%, respectively. MRC AML trials employ a short course of triple intrathecal chemotherapy alone for CNS-directed treatment and CNS relapse is uncommon. Improvements in supportive care have contributed to improved outcomes and the number of deaths in remission fell between trials. Anthracycline-related cardiotoxicity remains a concern and the current MRC AML 15 trial tests the feasibility of reducing anthracycline dosage without compromising outcome by comparing standard MRC anthracycline-based consolidation with high-dose ara-C. MRC studies suggest that the role of allo-BMT is limited in 1st CR and that there may be a ceiling of benefit from current or conventional chemotherapy.

Long-term donepezil treatment in 565 patients with Alzheimer's disease (AD2000): randomised double-blind trial.

BACKGROUND: Cholinesterase inhibitors produce small improvements in cognitive and global assessments in Alzheimer's disease. We aimed to determine whether donepezil produces worthwhile improvements in disability, dependency, behavioural and psychological symptoms, carers' psychological wellbeing, or delay in institutionalisation. If so, which patients benefit, from what dose, and for how long? METHODS: 565 community-resident patients with mild to moderate Alzheimer's disease entered a 12-week run-in period in which they were randomly allocated donepezil (5 mg/day) or placebo. 486 who completed this period were rerandomised to either donepezil (5 or 10 mg/day) or placebo, with double-blind treatment continuing as long as judged appropriate. Primary endpoints were entry to institutional care and progression of disability, defined by loss of either two of four basic, or six of 11 instrumental, activities on the Bristol activities of daily living scale (BADLS). Outcome assessments were sought for all patients and analysed by logrank and multilevel models. FINDINGS: Cognition averaged 0.8 MMSE (mini-mental state examination) points better (95% CI 0.5-1.2; p<0.0001) and functionality 1.0 BADLS points better (0.5-1.6; p<0.0001) with donepezil over the first 2 years. No significant benefits were seen with donepezil compared with placebo in institutionalisation (42% vs 44% at 3 years; p=0.4) or progression of disability (58% vs 59% at 3 years; p=0.4). The relative risk of entering institutional care in the donepezil group compared with placebo was 0.97 (95% CI 0.72-1.30; p=0.8); the relative risk of progression of disability or entering institutional care was 0.96 (95% CI 0.74-1.24; p=0.7). Similarly, no significant differences were seen between donepezil and placebo in behavioural and psychological symptoms, carer psychopathology, formal care costs, unpaid caregiver time, adverse events or deaths, or between 5 mg and 10 mg donepezil. INTERPRETATION: Donepezil is not cost effective, with benefits below minimally relevant thresholds. More effective treatments than cholinesterase inhibitors are needed for Alzheimer's disease.

The HSP90 inhibitor ganetespib: A potential effective agent for Acute Myeloid Leukemia in combination with cytarabine.

HSP90 is a multi-client chaperone involved in regulating a large array of cellular processes and is commonly overexpressed in many different cancer types including hematological malignancies. Inhibition of HSP90 holds promise for targeting multiple molecular abnormalities and is therefore an attractive target for heterogeneous malignancies such as Acute Myeloid Leukemia (AML). Ganetespib is a highly potent second generation HSP90 inhibitor which we show is significantly more effective against primary AML blasts at nanomolar concentrations when compared with cytarabine (p<0.001). Dose dependant cytotoxicity was observed with an apoptotic response coordinate with the loss of pro-survival signaling through the client protein AKT. Combination treatment of primary blasts with ganetespib and cytarabine showed good synergistic interaction (combination index (CI): 0.47) across a range of drug effects with associated reduction in HSP70 feedback and AKT signaling levels. In summary, we show ganetespib to have high activity in primary AMLs as a monotherapy and a synergistic relationship with cytarabine when combined. The combination of cytotoxic cell death, suppression of cytoprotective/drug resistance mechanisms such as AKT and reduced clinical toxicity compared to other HSP90 inhibitors provide strong rationale for the clinical assessment of ganetespib in AML.

Telomere fusion threshold identifies a poor prognostic subset of breast cancer patients.

Telomere dysfunction and fusion can drive genomic instability and clonal evolution in human tumours, including breast cancer. Telomere length is a critical determinant of telomere function and has been evaluated as a prognostic marker in several tumour types, but it has yet to be used in the clinical setting. Here we show that high-resolution telomere length analysis, together with a specific telomere fusion threshold, is highly prognostic for overall survival in a cohort of patients diagnosed with invasive ductal carcinoma of the breast (n = 120). The telomere fusion threshold defined a small subset of patients with an extremely poor clinical outcome, with a median survival of less than 12 months (HR = 21.4 (7.9-57.6), P < 0.0001). Furthermore, this telomere length threshold was independent of ER, PGR, HER2 status, NPI, or grade and was the dominant variable in multivariate analysis. We conclude that the fusogenic telomere length threshold provides a powerful, independent prognostic marker with clinical utility in breast cancer. Larger prospective studies are now required to determine the optimal way to incorporate high-resolution telomere length analysis into multivariate prognostic algorithms for patients diagnosed with breast cancer.

A comparative assessment of the curative potential of reduced intensity allografts in acute myeloid leukaemia.

Allogeneic stem cell transplantation (SCT) provides the best mechanism of preventing relapse in acute myeloid leukaemia (AML). However non-relapse mortality (NRM) negates this benefit in older patients. Reduced intensity conditioning (RIC) permits SCT with reduced NRM, but its contribution to cure is uncertain. In the MRC AML15 Trial, patients in remission without favourable risk disease could receive SCT from a matched sibling or unrelated donor (MUD). If aged >45 years, a RIC was recommended and in patients aged 35-44 years, either RIC or myeloablative conditioning was permitted. The aim was to determine which approach improved survival and within which prespecified cytogenetic groups. RIC transplants significantly reduced relapse (adjusted hazard ratio (HR) 0.66 (0.50-0.85), P=0.002) compared to chemotherapy The 5-year overall survival from a sibling RIC (61%) was superior to a MUD RIC (37%; adjusted HR 1.50 (1.01-2.21), P=0.04) due to lower NRM (34 vs 14%, P=0.002) In adjusted analyses, there was a survival benefit for sibling RIC over chemotherapy (59 vs 49%, HR 0.75 (0.57-0.97), P=0.03), with consistent results in intermediate and adverse-risk patients. In patients aged 35-44 years, best outcomes were seen with a sibling RIC transplant, although a comparison with chemotherapy and myeloablative transplant was not significant in adjusted analyses (P=0.3).

A randomised comparison of the novel nucleoside analogue sapacitabine with low-dose cytarabine in older patients with acute myeloid leukaemia.

The development of new treatments for older patients with acute myeloid leukaemia (AML) is an active area, but has met with limited success. Sapacitabine is a novel orally administered nucleoside analogue that has shown encouraging activity in unrandomised early-stage trials. We randomised 143 untreated patients with AML or with high-risk myelodysplastic syndrome (>10% marrow blasts) between sapacitibine and low-dose ara-C (LDAC) in our 'Pick a Winner' trial design. At the planned interim analysis there was no difference between LDAC and sapacitibine in terms of remission rate (CR/CRi, 27% vs 16% hazard ratio (HR) 1.98(0.90-4.39) P=0.09), relapse-free survival (10% vs 14% at 2 years, HR 0.73(0.33-1.61) P=0.4) or overall survival (OS; 12% vs 11% at 2 years, HR 1.24(0.86-1.78) P=0.2). Sapacitibine was well tolerated, apart from more grade 3/4 diarrhoea. On the basis of these findings sapacitibine did not show sufficient evidence of benefit over LDAC for the trial to be continued.

Resistance prediction in AML: analysis of 4601 patients from MRC/NCRI, HOVON/SAKK, SWOG and MD Anderson Cancer Center.

Therapeutic resistance remains the principal problem in acute myeloid leukemia (AML). We used area under receiver-operating characteristic curves (AUCs) to quantify our ability to predict therapeutic resistance in individual patients, where AUC=1.0 denotes perfect prediction and AUC=0.5 denotes a coin flip, using data from 4601 patients with newly diagnosed AML given induction therapy with 3+7 or more intense standard regimens in UK Medical Research Council/National Cancer Research Institute, Dutch-Belgian Cooperative Trial Group for Hematology/Oncology/Swiss Group for Clinical Cancer Research, US cooperative group SWOG and MD Anderson Cancer Center studies. Age, performance status, white blood cell count, secondary disease, cytogenetic risk and FLT3-ITD/NPM1 mutation status were each independently associated with failure to achieve complete remission despite no early death ('primary refractoriness'). However, the AUC of a bootstrap-corrected multivariable model predicting this outcome was only 0.78, indicating only fair predictive ability. Removal of FLT3-ITD and NPM1 information only slightly decreased the AUC (0.76). Prediction of resistance, defined as primary refractoriness or short relapse-free survival, was even more difficult. Our limited ability to forecast resistance based on routinely available pretreatment covariates provides a rationale for continued randomization between standard and new therapies and supports further examination of genetic and posttreatment data to optimize resistance prediction in AML.

Tau gene mutation K257T causes a tauopathy similar to Pick's disease.

Exonic and intronic mutations in Tau cause neurodegenerative syndromes characterized by frontotemporal dementia and filamentous tau protein deposits. Here we describe a K257T missense mutation in exon 9 of Tau. The proband, a 47-yr-old male, presented with severe personality changes followed by semantic memory loss. A diagnosis of Pick's disease was made. The symptoms progressed until death at age 51. The proband's brain showed a marked frontotemporal atrophy that was most pronounced in the temporal lobes. Numerous tau-immunoreactive Pick bodies were present in the neocortex and the hippocampal formation, as well as in some subcortical brain regions. Their appearance and staining characteristics were indistinguishable from those of sporadic Pick's disease. Diffuse staining for hyperphosphorylated tau was also observed in some nerve cell bodies. Immunoblot analysis of sarkosyl-insoluble tau showed 2 major bands of 60 and 64 kDa and 2 very minor bands of 68 and 72 kDa. Upon dephosphorylation, these bands resolved into 6 bands consisting of 3-repeat and 4-repeat tau isoforms, with an overall preponderance of 3-repeat tau. Isolated tau filaments were narrow, irregularly twisted ribbons. Biochemically, recombinant tau proteins with the K257T mutation showed a reduced ability to promote microtubule assembly, suggesting that this may be the primary effect of the mutation. In addition, the K257T mutation was found to stimulate heparin-induced assembly of 3-repeat tau into filaments. Taken together, the present findings indicate that the K257T mutation in Tau can cause a dementing condition similar to Pick's disease.

The messenger RNAs for the N-methyl-D-aspartate receptor subunits show region-specific expression of different subunit composition in the human brain.

The expression of the messenger RNAs encoding N-methyl-D-aspartate receptor subunits in neurologically normal post-mortem human brain was studied by in situ hybridization. In the caudate, putamen and nucleus accumbens strong hybridization signals were observed for N-methyl-D-aspartate R1-1 messenger RNA but much weaker signals for N-methyl-D-aspartate R1-3 and N-methyl-D-aspartate R1-4, N-Methyl-D-aspartate R1-2 was not detectable. N-methyl-D-aspartate R2B was the only N-methyl-D-aspartate R2 subunit detected in these nuclei. In the hippocampus the messenger RNAs for both N-methyl-D-aspartate R1-1 and N-methyl-D-aspartate R1-4 were strongly expressed in the dentate gyrus, CA3-CA1 pyramidal cells, subiculum, entorhinal cortex and perirhinal cortex. Much lower expression was seen for N-methyl-D-aspartate R1-2 and N-methyl-D-aspartate R1-3. The messenger RNAs for both N-methyl-D-aspartate R2A and N-methyl-D-aspartate R2B, but not N-methyl-D-aspartate R2C, subunits were expressed in the hippocampus. In the temporal cortex all N-methyl-D-aspartate RI isoforms were expressed (N-methyl-D-aspartate R1-1 and N-methyl-D-aspartate R1-4 being the most abundant) and N-methyl-D-aspartate R2A and N-methyl-D-aspartate R2B but not N-methyl-D-aspartate R2C were also moderately expressed. In the brain stem N-methyl-D-aspartate R1-4 was strongly expressed in various nuclei including the locus coeruleus, nucleus centralis superior and deep pontine nuclei. Only weak expression was seen for N-methyl-D-aspartate RI-1 and N-methyl-D-aspartate R1-3 but not N-methyl-D-aspartate RI-2; of the N-methyl-D-aspartate R2 subunits only N-methyl-D-aspartate R2C was found to be expressed in these nuclei. In the cerebellum all the N-methyl-D-aspartate I isoforms were expressed (mostly N-methyl-D-aspartate R1-4) in the Purkinje layer which also expressed N-methyl-D-aspartate R2A and N-methyl-D-aspartate R2C. In the molecular layer cells were found expressing N-methyl-D-aspartate R1-4 and N-methyl-D-aspartate R2B and cells in the granule layer were found to express N-methyl-D-aspartate R1-1, N-methyl-D-aspartate R1-3 and N-methyl-D-aspartate R1-4 and N-methyl-D-aspartate R2C only. Preliminary studies indicated that the messenger RNA for the N-methyl-D-aspartate R2D subunit was not expressed in the above areas of brain. These results give the first demonstration of the distribution of N-methyl-D-aspartate receptor subunit messenger RNAs in the human brain. The region-specific expression of subunit combinations suggests a heterogeneity of N-methyl-D-aspartate receptors with diverse physiological/pathophysiological roles and provides a rationale for the development of discriminatory N-methyl-D-aspartate receptor antagonists to target selective neuronal populations.

Corner cutting compromises clinical trials: the inherent problems with up-front randomisation and a common standard arm.

To minimise bias, clinical trials must be randomised, and all patients analysed by allocated treatment. With several separate randomisations, patients should be analysed only within the randomisation they entered, and not compared against patients in different randomisations. Some people worry that randomised trials result in many patients receiving an inferior treatment. Accordingly, several suggestions have been made, including a combined control arm for many trials, and performing several randomisations at the same up-front time point. These approaches fundamentally contradict the above statistical principles, and can lead to wrong conclusions. We explore these problems, with reference to one such recent proposal.