query: Deleting Raptor reduces G-CSF levels.

positive: Oncogenic mTOR signaling recruits myeloid-derived suppressor cells to promote tumor initiation Myeloid-derived suppressor cells (MDSCs) play critical roles in primary and metastatic cancer progression. MDSC regulation is widely variable even among patients harbouring the same type of malignancy, and the mechanisms governing such heterogeneity are largely unknown. Here, integrating human tumour genomics and syngeneic mammary tumour models, we demonstrate that mTOR signalling in cancer cells dictates a mammary tumour's ability to stimulate MDSC accumulation through regulating G-CSF. Inhibiting this pathway or its activators (for example, FGFR) impairs tumour progression, which is partially rescued by restoring MDSCs or G-CSF. Tumour-initiating cells (TICs) exhibit elevated G-CSF. MDSCs reciprocally increase TIC frequency through activating Notch in tumour cells, forming a feedforward loop. Analyses of primary breast cancers and patient-derived xenografts corroborate these mechanisms in patients. These findings establish a non-canonical oncogenic role of mTOR signalling in recruiting pro-tumorigenic MDSCs and show how defined cancer subsets may evolve to promote and depend on a distinct immune microenvironment.

negative: Clinical effects of Abeta immunization (AN1792) in patients with AD in an interrupted trial. BACKGROUND AN1792 (beta-amyloid [Abeta]1-42) immunization reduces Abeta plaque burden and preserves cognitive function in APP transgenic mice. The authors report the results of a phase IIa immunotherapy trial of AN1792(QS-21) in patients with mild to moderate Alzheimer disease (AD) that was interrupted because of meningoencephalitis in 6% of immunized patients. METHODS This randomized, multicenter, placebo-controlled, double-blind trial of IM AN1792 225 microg plus the adjuvant QS-21 50 microg (300 patients) and saline (72 patients) included patients aged 50 to 85 years with probable AD, Mini-Mental State Examination (MMSE) 15 to 26. Injections were planned for months 0, 1, 3, 6, 9, and 12. Safety and tolerability were evaluated, and pilot efficacy (AD Assessment Scale-Cognitive Subscale [ADAS-Cog], MRI, neuropsychological test battery [NTB], CSF tau, and Abeta42) was assessed in anti-AN1792 antibody responder patients (immunoglobulin G titer > or = 1:2,200). RESULTS Following reports of meningoencephalitis (overall 18/300 [6%]), immunization was stopped after one (2 patients), two (274 patients), or three (24 patients) injections. Of the 300 AN1792(QS-21)-treated patients, 59 (19.7%) developed the predetermined antibody response. Double-blind assessments were maintained for 12 months. No significant differences were found between antibody responder and placebo groups for ADAS-Cog, Disability Assessment for Dementia, Clinical Dementia Rating, MMSE, or Clinical Global Impression of Change, but analyses of the z-score composite across the NTB revealed differences favoring antibody responders (0.03 +/- 0.37 vs -0.20 +/- 0.45; p = 0.020). In the small subset of subjects who had CSF examinations, CSF tau was decreased in antibody responders (n = 11) vs placebo subjects (n = 10; p < 0.001). CONCLUSION Although interrupted, this trial provides an indication that Abeta immunotherapy may be useful in Alzheimer disease.

negative: Systems metabolic engineering of Escherichia coli for L-threonine production Amino-acid producers have traditionally been developed by repeated random mutagenesis owing to the difficulty in rationally engineering the complex and highly regulated metabolic network. Here, we report the development of the genetically defined L-threonine overproducing Escherichia coli strain by systems metabolic engineering. Feedback inhibitions of aspartokinase I and III (encoded by thrA and lysC, respectively) and transcriptional attenuation regulations (located in thrL) were removed. Pathways for Thr degradation were removed by deleting tdh and mutating ilvA. The metA and lysA genes were deleted to make more precursors available for Thr biosynthesis. Further target genes to be engineered were identified by transcriptome profiling combined with in silico flux response analysis, and their expression levels were manipulated accordingly. The final engineered E. coli strain was able to produce Thr with a high yield of 0.393 g per gram of glucose, and 82.4 g/l Thr by fed-batch culture. The systems metabolic engineering strategy reported here may be broadly employed for developing genetically defined organisms for the efficient production of various bioproducts.

negative: Rho, Rac and Cdc42 regulate actin organization and cell adhesion in macrophages. Rho family proteins are known to regulate actin organization in fibroblasts, but their functions in cells of haematopoietic origin have not been studied in detail. Bac1.2F5 cells are a colony-stimulating factor-1 (CSF-1)-dependent murine macrophage cell line; CSF-1 stimulates their proliferation and motility, and acts as a chemoattractant. CSF-1 rapidly induced actin reorganization in Bac1 cells: it stimulated the formation of filopodia, lamellipodia and membrane ruffles at the plasma membrane, as well as the appearance of fine actin cables within the cell interior. Microinjection of constitutively activated (V12)Rac1 stimulated lamellipodium formation and membrane ruffling. The dominant inhibitory Rac mutant, N17Rac1, inhibited CSF-1-induced lamellipodium formation, and also induced cell rounding. V12Cdc42 induced the formation of long filopodia, while the dominant inhibitory mutant N17Cdc42 prevented CSF-1-induced formation of filopodia but not lamellipodia. V14RhoA stimulated actin cable assembly and cell contraction, while the Rho inhibitor, C3 transferase, induced the loss of actin cables. Bac1 cells had cell-to-substratum adhesion sites containing beta1 integrin, pp125FAK, paxillin, vinculin, and tyrosine phosphorylated proteins. These 'focal complexes' were present in growing and CSF-1-starved cells, but were disassembled in cells injected with N17Cdc42 or N17Rac1. Interestingly, beta1 integrin did not disperse until long after focal phosphotyrosine and vinculin staining had disappeared. We conclude that in Bac1 macrophages Cdc42, Rac and Rho regulate the formation of distinct actin filament-based structures, and that Cdc42 and Rac are also required for the assembly of adhesion sites to the extracellular matrix.

negative: How do I perform a lumbar puncture and analyze the results to diagnose bacterial meningitis? CONTEXT Diagnostic lumbar punctures (LPs), commonly used to rule out meningitis, are associated with adverse events. OBJECTIVE To systematically review the evidence about diagnostic LP techniques that may decrease the risk of adverse events and the evidence about test accuracy of cerebrospinal fluid (CSF) analysis in adult patients with suspected bacterial meningitis. DATA SOURCES We searched the Cochrane Library, MEDLINE (using Ovid and PubMed) from 1966 to January 2006 and EMBASE from 1980 to January 2006 without language restrictions to identify relevant studies and identified others from the bibliographies of retrieved articles. STUDY SELECTION We included randomized trials of patients aged 18 years or older undergoing interventions to facilitate a successful diagnostic LP or to potentially reduce adverse events. Studies assessing the accuracy of biochemical analysis of the CSF for possible bacterial meningitis were also identified. DATA EXTRACTION Two investigators independently appraised study quality and extracted relevant data. For studies of the LP technique, data on the intervention and the outcome were extracted. For studies of the laboratory diagnosis of bacterial meningitis, data on the reference standard and test accuracy were extracted. DATA SYNTHESIS We found 15 randomized trials. A random-effects model was used for quantitative synthesis. Five studies of 587 patients compared atraumatic needles with standard needles and found a nonsignificant decrease in the odds of headache with an atraumatic needle (absolute risk reduction [ARR], 12.3%; 95% confidence interval [CI], -1.72% to 26.2%). Reinsertion of the stylet before needle removal decreased the risk of headache (ARR, 11.3%; 95% CI, 6.50%-16.2%). The combined results from 4 studies of 717 patients showed a nonsignificant decrease in headache in patients who were mobilized after LP (ARR, 2.9%; 95% CI, -3.4 to 9.3%). Four studies on the accuracy of biochemical analysis of CSF in patients with suspected meningitis met inclusion criteria. A CSF-blood glucose ratio of 0.4 or less (likelihood ratio [LR], 18; 95% CI, 12-27]), CSF white blood cell count of 500/muL or higher (LR, 15; 95% CI, 10-22), and CSF lactate level of 31.53 mg/dL or more (> or =3.5 mmol/L; LR, 21; 95% CI, 14-32) accurately diagnosed bacterial meningitis. CONCLUSIONS These data suggest that small-gauge, atraumatic needles may decrease the risk of headache after diagnostic LP. Reinsertion of the stylet before needle removal should occur and patients do not require bed rest after the procedure. Future research should focus on evaluating interventions to optimize the success of a diagnostic LP and to enhance training in procedural skills.

negative: A link between inflammation and metastasis: serum amyloid A1 and A3 induce metastasis, and are targets of metastasis-inducing S100A4 S100A4 is implicated in metastasis and chronic inflammation, but its function remains uncertain. Here we establish an S100A4-dependent link between inflammation and metastatic tumor progression. We found that the acute-phase response proteins serum amyloid A (SAA) 1 and SAA3 are transcriptional targets of S100A4 via Toll-like receptor 4 (TLR4)/nuclear factor-κB signaling. SAA proteins stimulated the transcription of RANTES (regulated upon activation normal T-cell expressed and presumably secreted), G-CSF (granulocyte-colony-stimulating factor) and MMP2 (matrix metalloproteinase 2), MMP3, MMP9 and MMP13. We have also shown for the first time that SAA stimulate their own transcription as well as that of proinflammatory S100A8 and S100A9 proteins. Moreover, they strongly enhanced tumor cell adhesion to fibronectin, and stimulated migration and invasion of human and mouse tumor cells. Intravenously injected S100A4 protein induced expression of SAA proteins and cytokines in an organ-specific manner. In a breast cancer animal model, ectopic expression of SAA1 or SAA3 in tumor cells potently promoted widespread metastasis formation accompanied by a massive infiltration of immune cells. Furthermore, coordinate expression of S100A4 and SAA in tumor samples from colorectal carcinoma patients significantly correlated with reduced overall survival. These data show that SAA proteins are effectors for the metastasis-promoting functions of S100A4, and serve as a link between inflammation and tumor progression.

negative: Crypt stem cells as the cells-of-origin of intestinal cancer Intestinal cancer is initiated by Wnt-pathway-activating mutations in genes such as adenomatous polyposis coli (APC). As in most cancers, the cell of origin has remained elusive. In a previously established Lgr5 (leucine-rich-repeat containing G-protein-coupled receptor 5) knockin mouse model, a tamoxifen-inducible Cre recombinase is expressed in long-lived intestinal stem cells. Here we show that deletion of Apc in these stem cells leads to their transformation within days. Transformed stem cells remain located at crypt bottoms, while fuelling a growing microadenoma. These microadenomas show unimpeded growth and develop into macroscopic adenomas within 3-5weeks. The distribution of Lgr5+ cells within stem-cell-derived adenomas indicates that a stem cell/progenitor cell hierarchy is maintained in early neoplastic lesions. When Apc is deleted in short-lived transit-amplifying cells using a different cre mouse, the growth of the induced microadenomas rapidly stalls. Even after 30weeks, large adenomas are very rare in these mice. We conclude that stem-cell-specific loss of Apc results in progressively growing neoplasia.

negative: Klebsiella aerogenes urease gene cluster: sequence of ureD and demonstration that four accessory genes (ureD, ureE, ureF, and ureG) are involved in nickel metallocenter biosynthesis. The region located immediately upstream from the Klebsiella aerogenes urease structural genes was sequenced and shown to possess an open reading frame capable of encoding a 29.8-kDa peptide. Deletions were generated in this gene, denoted ureD, and in each of the genes (ureE, ureF, and ureG) located immediately downstream of the three structural genes. Transformation of the mutated plasmids into Escherichia coli resulted in high levels of urease expression, but the enzyme was inactive (deletions in ureD, ureF, or ureG) or only partially active (deletions in ureE). Ureases were purified from the recombinant cells and shown to be identical to control enzyme when analyzed by gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis; however, in every case the activity levels correlated to nickel contents as analyzed by atomic absorption analysis. UreD, UreE, UreF, and UreG peptides were tentatively identified by gel electrophoretic comparison of mutant and control cell extracts, by in vivo expression of separately cloned genes, or by in vitro transcription-translation analyses; the assignments were confirmed for UreE and UreG by amino-terminal sequencing. The latter peptides (apparent M(r)s, 23,900 and 28,500) were present at high levels comparable to those of the urease subunits, whereas the amounts of UreF (apparent M(r), 27,000) and UreD (apparent M(r), 29,300) were greatly reduced, perhaps because of the lack of good ribosome binding sites in the regions upstream of these open reading frames. These results demonstrate that all four accessory genes are necessary for the functional incorporation of the urease metallocenter.

negative: Chimeric antigen receptor-modified T cells for acute lymphoid leukemia. Chimeric antigen receptor-modified T cells with specificity for CD19 have shown promise in the treatment of chronic lymphocytic leukemia (CLL). It remains to be established whether chimeric antigen receptor T cells have clinical activity in acute lymphoblastic leukemia (ALL). Two children with relapsed and refractory pre-B-cell ALL received infusions of T cells transduced with anti-CD19 antibody and a T-cell signaling molecule (CTL019 chimeric antigen receptor T cells), at a dose of 1.4×10(6) to 1.2×10(7) CTL019 cells per kilogram of body weight. In both patients, CTL019 T cells expanded to a level that was more than 1000 times as high as the initial engraftment level, and the cells were identified in bone marrow. In addition, the chimeric antigen receptor T cells were observed in the cerebrospinal fluid (CSF), where they persisted at high levels for at least 6 months. Eight grade 3 or 4 adverse events were noted. The cytokine-release syndrome and B-cell aplasia developed in both patients. In one child, the cytokine-release syndrome was severe; cytokine blockade with etanercept and tocilizumab was effective in reversing the syndrome and did not prevent expansion of chimeric antigen receptor T cells or reduce antileukemic efficacy. Complete remission was observed in both patients and is ongoing in one patient at 11 months after treatment. The other patient had a relapse, with blast cells that no longer expressed CD19, approximately 2 months after treatment. Chimeric antigen receptor-modified T cells are capable of killing even aggressive, treatment-refractory acute leukemia cells in vivo. The emergence of tumor cells that no longer express the target indicates a need to target other molecules in addition to CD19 in some patients with ALL.

negative: Development of an insect model for the in vivo pathogenicity testing of yeasts. Conventional in vivo assays to determine the relative pathogenicity of yeast isolates rely upon the use of a range of mammalian species. The purpose of the work presented here was to investigate the possibility of using an insect (Galleria mellonella) as a model system for in vivo pathogenicity testing. The haemolymph of G. mellonella larvae was inoculated with PBS containing different concentrations of stationary phase yeasts of the genus Candida by injection at the last pro-leg. Larvae were incubated at 30 degrees C and monitored over 72 hours. Results indicate that G. mellonella can be killed by the pathogenic yeast Candida albicans and by a range of other Candida species but not to a significant extent by the yeast Saccharomyces cerevisiae. The kill kinetics for larvae inoculated with clinical and laboratory isolates of C. albicans indicate the former class of isolates to be more pathogenic. Differences in the relative pathogenicity of a range of Candida species may be distinguished using G. mellonella as a model. This work indicates that G. mellonella may be employed to give results consistent with data previously obtained using mammals in conventional in vivo pathogenicity testing. Larvae of G. mellonella are inexpensive to culture, easy to manipulate and their use may reduce the need to employ mammals for routine in vivo pathogenicity testing with a concomitant reduction in mammalian suffering.

negative: Lin28b is sufficient to drive liver cancer and necessary for its maintenance in murine models. Lin28a/b are RNA-binding proteins that influence stem cell maintenance, metabolism, and oncogenesis. Poorly differentiated, aggressive cancers often overexpress Lin28, but its role in tumor initiation or maintenance has not been definitively addressed. We report that LIN28B overexpression is sufficient to initiate hepatoblastoma and hepatocellular carcinoma in murine models. We also detected Lin28b overexpression in MYC-driven hepatoblastomas, and liver-specific deletion of Lin28a/b reduced tumor burden, extended latency, and prolonged survival. Both intravenous siRNA against Lin28b and conditional Lin28b deletion reduced tumor burden and prolonged survival. Igf2bp proteins are upregulated, and Igf2bp3 is required in the context of LIN28B overexpression to promote growth. Therefore, multiple murine models demonstrate that Lin28b is both sufficient to initiate liver cancer and necessary for its maintenance.

negative: Effects of interventions in pregnancy on maternal weight and obstetric outcomes: meta-analysis of randomised evidence OBJECTIVE To evaluate the effects of dietary and lifestyle interventions in pregnancy on maternal and fetal weight and to quantify the effects of these interventions on obstetric outcomes. DESIGN Systematic review and meta-analysis. DATA SOURCES Major databases from inception to January 2012 without language restrictions. STUDY SELECTION Randomised controlled trials that evaluated any dietary or lifestyle interventions with potential to influence maternal weight during pregnancy and outcomes of pregnancy. DATA SYNTHESIS Results summarised as relative risks for dichotomous data and mean differences for continuous data. RESULTS We identified 44 relevant randomised controlled trials (7278 women) evaluating three categories of interventions: diet, physical activity, and a mixed approach. Overall, there was 1.42 kg reduction (95% confidence interval 0.95 to 1.89 kg) in gestational weight gain with any intervention compared with control. With all interventions combined, there were no significant differences in birth weight (mean difference -50 g, -100 to 0 g) and the incidence of large for gestational age (relative risk 0.85, 0.66 to 1.09) or small for gestational age (1.00, 0.78 to 1.28) babies between the groups, though by itself physical activity was associated with reduced birth weight (mean difference -60 g, -120 to -10 g). Interventions were associated with a reduced the risk of pre-eclampsia (0.74, 0.60 to 0.92) and shoulder dystocia (0.39, 0.22 to 0.70), with no significant effect on other critically important outcomes. Dietary intervention resulted in the largest reduction in maternal gestational weight gain (3.84 kg, 2.45 to 5.22 kg), with improved pregnancy outcomes compared with other interventions. The overall evidence rating was low to very low for important outcomes such as pre-eclampsia, gestational diabetes, gestational hypertension, and preterm delivery. CONCLUSIONS Dietary and lifestyle interventions in pregnancy can reduce maternal gestational weight gain and improve outcomes for both mother and baby. Among the interventions, those based on diet are the most effective and are associated with reductions in maternal gestational weight gain and improved obstetric outcomes.

negative: Array-based Comparative Genomic Hybridization for Genome-Wide Screening of DNA Copy Number in Bladder Tumors Genome-wide copy number profiles were characterized in 41 primary bladder tumors using array-based comparative genomic hybridization (array CGH). In addition to previously identified alterations in large chromosomal regions, alterations were identified in many small genomic regions, some with high-level amplifications or homozygous deletions. High-level amplifications were detected for 192 genomic clones, most frequently at 6p22.3 (E2F3), 8p12 (FGFR1), 8q22.2 (CMYC), 11q13 (CCND1, EMS1, INT2), and 19q13.1 (CCNE). Homozygous deletions were detected in 51 genomic clones, with four showing deletions in more than one case: two clones mapping to 9p21.3 (CDKN2A/p16, in nine cases), one at 8p23.1 (three cases), and one at 11p13 (two cases). Significant correlations were observed between copy number gain of clones containing CCNE1 and gain of ERBB2, and between gain of CCND1 and deletion of TP53. In addition, there was a significant complementary association between gain of CCND1 and gain of E2F3. Although there was no significant relationship between copy number changes and tumor stage or grade, the linked behavior among genomic loci suggests that array CGH will be increasingly important in understanding pathways critical to bladder tumor biology.

negative: Hypoalbuminemia in acute illness: is there a rationale for intervention? A meta-analysis of cohort studies and controlled trials. OBJECTIVE To determine whether hypoalbuminemia is an independent risk factor for poor outcome in the acutely ill, and to assess the potential of exogenous albumin administration for improving outcomes in hypoalbuminemic patients. SUMMARY BACKGROUND DATA Hypoalbuminemia is associated with poor outcomes in acutely ill patients, but whether this association is causal has remained unclear. Trials investigating albumin therapy to correct hypoalbuminemia have proven inconclusive. METHODS A meta-analysis was conducted of 90 cohort studies with 291,433 total patients evaluating hypoalbuminemia as an outcome predictor by multivariate analysis and, separately, of nine prospective controlled trials with 535 total patients on correcting hypoalbuminemia. RESULTS Hypoalbuminemia was a potent, dose-dependent independent predictor of poor outcome. Each 10-g/L decline in serum albumin concentration significantly raised the odds of mortality by 137%, morbidity by 89%, prolonged intensive care unit and hospital stay respectively by 28% and 71%, and increased resource utilization by 66%. The association between hypoalbuminemia and poor outcome appeared to be independent of both nutritional status and inflammation. Analysis of dose-dependency in controlled trials of albumin therapy suggested that complication rates may be reduced when the serum albumin level attained during albumin administration exceeds 30 g/L.   CONCLUSIONS Hypoalbuminemia is strongly associated with poor clinical outcomes. Further well-designed trials are needed to characterize the effects of albumin therapy in hypoalbuminemic patients. In the interim, there is no compelling basis to withhold albumin therapy if it is judged clinically appropriate.

negative: hnRNP A1 associates with telomere ends and stimulates telomerase activity. Telomerase is a ribonucleoprotein enzyme complex that reverse-transcribes an integral RNA template to add short DNA repeats to the 3'-ends of telomeres. G-quadruplex structure in a DNA substrate can block its extension by telomerase. We have found that hnRNP A1--which was previously implicated in telomere length regulation--binds to both single-stranded and structured human telomeric repeats, and in the latter case, it disrupts their higher-order structure. Using an in vitro telomerase assay, we observed that depletion of hnRNP A/B proteins from 293 human embryonic kidney cell extracts dramatically reduced telomerase activity, which was fully recovered upon addition of purified recombinant hnRNP A1. This finding suggests that hnRNP A1 functions as an auxiliary, if not essential, factor of telomerase holoenzyme. We further show, using chromatin immunoprecipitation, that hnRNP A1 associates with human telomeres in vivo. We propose that hnRNP A1 stimulates telomere elongation through unwinding of a G-quadruplex or G-G hairpin structure formed at each translocation step.

negative: A conserved modified wobble nucleoside (mcm5s2U) in lysyl-tRNA is required for viability in yeast. Transfer RNAs specific for Gln, Lys, and Glu from all organisms (except Mycoplasma) and organelles have a 2-thiouridine derivative (xm(5)s(2)U) as wobble nucleoside. These tRNAs read the A- and G-ending codons in the split codon boxes His/Gln, Asn/Lys, and Asp/Glu. In eukaryotic cytoplasmic tRNAs the conserved constituent (xm(5)-) in position 5 of uridine is 5-methoxycarbonylmethyl (mcm(5)). A protein (Tuc1p) from yeast resembling the bacterial protein TtcA, which is required for the synthesis of 2-thiocytidine in position 32 of the tRNA, was shown instead to be required for the synthesis of 2-thiouridine in the wobble position (position 34). Apparently, an ancient member of the TtcA family has evolved to thiolate U34 in tRNAs of organisms from the domains Eukarya and Archaea. Deletion of the TUC1 gene together with a deletion of the ELP3 gene, which results in the lack of the mcm(5) side chain, removes all modifications from the wobble uridine derivatives of the cytoplasmic tRNAs specific for Gln, Lys, and Glu, and is lethal to the cell. Since excess of the unmodified form of these three tRNAs rescued the double mutant elp3 tuc1, the primary function of mcm(5)s(2)U34 seems to be to improve the efficiency to read the cognate codons rather than to prevent mis-sense errors. Surprisingly, overexpression of the mcm(5)s(2)U-lacking tRNA(Lys) alone was sufficient to restore viability of the double mutant.

negative: Sir2-Independent Life Span Extension by Calorie Restriction in Yeast Calorie restriction slows aging and increases life span in many organisms. In yeast, a mechanistic explanation has been proposed whereby calorie restriction slows aging by activating Sir2. Here we report the identification of a Sir2-independent pathway responsible for a majority of the longevity benefit associated with calorie restriction. Deletion of FOB1 and overexpression of SIR2 have been previously found to increase life span by reducing the levels of toxic rDNA circles in aged mother cells. We find that combining calorie restriction with either of these genetic interventions dramatically enhances longevity, resulting in the longest-lived yeast strain reported thus far. Further, calorie restriction results in a greater life span extension in cells lacking both Sir2 and Fob1 than in cells where Sir2 is present. These findings indicate that Sir2 and calorie restriction act in parallel pathways to promote longevity in yeast and, perhaps, higher eukaryotes.

negative: Effects of Abciximab on the architecture of platelet-rich clots in patients with acute myocardial infarction undergoing primary coronary intervention. BACKGROUND Abciximab plus aspirin improves the TIMI 3 flow rate of the infarct-related artery in patients treated with either percutaneous coronary intervention or thrombolysis. The present study investigated whether the reperfusion efficacy of abciximab relates to modifications of clot architecture in patients admitted for acute myocardial infarction (AMI). METHODS AND RESULTS A total of 23 AMI patients in the Abciximab before Direct angioplasty and stenting in Myocardial Infarction Regarding Acute and Long term follow-up (ADMIRAL) trial received, in a double-blind fashion, either abciximab (n=13) or placebo (n=10) before primary stenting. Viscoelastic (G' in dyne/cm(2)) and morphological (mean platelet aggregate surface area [SAG] in micrometer(2)) indexes of ex vivo platelet-rich clots (PRC) were assessed in a double-blind fashion before and after the bolus administration of abciximab or placebo. G' and SAG reflect the mechanical and morphological impact of activated platelets on the PRC fibrin network, respectively. Abciximab administration reduced G' by 63% (P=0.0001) and SAG by 65% (P=0.0007), and no effect was seen in the placebo group. These abciximab-related changes increased fibrin exposure as a consequence of the platelet-aggregate surface reduction and may have improved endogenous fibrinolysis. These effects were identified in all patients, independent of previous heparin administration. CONCLUSIONS Abciximab dramatically reduces platelet aggregate size and increases the fibrin accessibility of ex vivo PRC in AMI patients. These modifications could participate in the better coronary artery patency observed with abciximab.

negative: Differential role of CbpA and PspA in modulation of in vitro CXC chemokine responses of respiratory epithelial cells to infection with Streptococcus pneumoniae. Respiratory epithelial cells play an active part in the host response to respiratory pathogens, such as Streptococcus pneumoniae, by releasing chemokines responsible for neutrophil recruitment. In order to investigate the role of specific pneumococcal virulence factors in eliciting CXC chemokine responses, type II pneumocytes (A549) and nasopharyngeal cells (Detroit-562) were infected with S. pneumoniae D39 or mutants lacking choline-binding protein A (CbpA), pneumococcal surface protein A (PspA), or specific domains thereof. In response to wild-type D39, both A549 and Detroit-562 cells showed a significant increase in CXC chemokine mRNA and interleukin-8 protein. This response was increased twofold when a cbpA deletion mutant (DeltaCbpA) was used, suggesting that CbpA inhibits CXC chemokine induction. All three N-terminal domains of CbpA are required for this effect, as in-frame deletion of the respective region of cbpA had the same effect on the CXC chemokine response as deletion of cbpA altogether. Infection with a pspA deletion mutant (DeltaPspA) led to a twofold decrease in the CXC chemokine response of A549 but not Detroit-562 cells, compared to infection with D39 at 2 h. Thus, PspA appears to have the ability to stimulate early CXC chemokine release from A549 cells. Deletion of the region of pspA encoding the first N-terminal alpha-helical domain reduced the ability of S. pneumoniae to elicit a chemokine response to the same degree as deletion of pspA altogether. Thus, the N termini of CbpA and PspA exert differential effects on CXC chemokine induction in epithelial cells infected with S. pneumoniae.

negative: Increased Microerythrocyte Count in Homozygous α+-Thalassaemia Contributes to Protection against Severe Malarial Anaemia BACKGROUND The heritable haemoglobinopathy alpha(+)-thalassaemia is caused by the reduced synthesis of alpha-globin chains that form part of normal adult haemoglobin (Hb). Individuals homozygous for alpha(+)-thalassaemia have microcytosis and an increased erythrocyte count. Alpha(+)-thalassaemia homozygosity confers considerable protection against severe malaria, including severe malarial anaemia (SMA) (Hb concentration < 50 g/l), but does not influence parasite count. We tested the hypothesis that the erythrocyte indices associated with alpha(+)-thalassaemia homozygosity provide a haematological benefit during acute malaria. METHODS AND FINDINGS Data from children living on the north coast of Papua New Guinea who had participated in a case-control study of the protection afforded by alpha(+)-thalassaemia against severe malaria were reanalysed to assess the genotype-specific reduction in erythrocyte count and Hb levels associated with acute malarial disease. We observed a reduction in median erythrocyte count of approximately 1.5 x 10(12)/l in all children with acute falciparum malaria relative to values in community children (p < 0.001). We developed a simple mathematical model of the linear relationship between Hb concentration and erythrocyte count. This model predicted that children homozygous for alpha(+)-thalassaemia lose less Hb than children of normal genotype for a reduction in erythrocyte count of >1.1 x 10(12)/l as a result of the reduced mean cell Hb in homozygous alpha(+)-thalassaemia. In addition, children homozygous for alpha(+)-thalassaemia require a 10% greater reduction in erythrocyte count than children of normal genotype (p = 0.02) for Hb concentration to fall to 50 g/l, the cutoff for SMA. We estimated that the haematological profile in children homozygous for alpha(+)-thalassaemia reduces the risk of SMA during acute malaria compared to children of normal genotype (relative risk 0.52; 95% confidence interval [CI] 0.24-1.12, p = 0.09). CONCLUSIONS The increased erythrocyte count and microcytosis in children homozygous for alpha(+)-thalassaemia may contribute substantially to their protection against SMA. A lower concentration of Hb per erythrocyte and a larger population of erythrocytes may be a biologically advantageous strategy against the significant reduction in erythrocyte count that occurs during acute infection with the malaria parasite Plasmodium falciparum. This haematological profile may reduce the risk of anaemia by other Plasmodium species, as well as other causes of anaemia. Other host polymorphisms that induce an increased erythrocyte count and microcytosis may confer a similar advantage.

negative: Intrauterine environments and breast cancer risk: meta-analysis and systematic review INTRODUCTION Various perinatal factors, including birth weight, birth order, maternal age, gestational age, twin status, and parental smoking, have been postulated to affect breast cancer risk in daughters by altering the hormonal environment of the developing fetal mammary glands. Despite ample biologic plausibility, epidemiologic studies to date have yielded conflicting results. We investigated the associations between perinatal factors and subsequent breast cancer risk through meta-analyses. METHODS We reviewed breast cancer studies published from January 1966 to February 2007 that included data on birth weight, birth order, maternal age, gestational age, twin status, and maternal or paternal smoking. Meta-analyses using random effect models were employed to summarize the results. RESULTS We found that heavier birth weights were associated with increased breast cancer risk, with studies involving five categories of birth weight identifying odds ratios (ORs) of 1.24 (95% confidence interval [CI] 1.04 to 1.48) for 4,000 g or more and 1.15 (95% CI 1.04 to 1.26) for 3,500 g to 3,999 g, relative to a birth weight of 2,500 to 2,599 g. These studies provided no support for a J-shaped relationship of birthweight to risk. Support for an association with birthweight was also derived from studies based on three birth weight categories (OR 1.15 [95% CI 1.01 to 1.31] for > or =4,000 g relative to <3,000 g) and two birth weight categories (OR 1.09 [95% CI 1.02 to 1.18] for > or =3,000 g relative to <3,000 g). Women born to older mothers and twins were also at some increased risk, but the results were heterogeneous across studies and publication years. Birth order, prematurity, and maternal smoking were unrelated to breast cancer risk. CONCLUSION Our findings provide some support for the hypothesis that in utero exposures reflective of higher endogenous hormone levels could affect risk for development of breast cancer in adulthood.

negative: Islet1 deletion causes kidney agenesis and hydroureter resembling CAKUT. Islet1 (Isl1) is a transcription factor transiently expressed in a subset of heart and limb progenitors. During studies of limb development, conditional Isl1 deletion produced unexpected kidney abnormalities. Here, we studied the renal expression of Isl1 and whether it has a role in kidney development. In situ hybridization revealed Isl1 expression in the mesenchymal cells surrounding the base of the ureteric bud in mice. Conditional deletion of Isl1 caused kidney agenesis or hypoplasia and hydroureter, a phenotype resembling human congenital anomalies of the kidney and urinary tract (CAKUT). The absence of Isl1 led to ectopic branching of the ureteric bud out from the nephric duct or to the formation of accessory buds, both of which could lead to obstruction of the ureter-bladder junction and consequent hydroureter. The abnormal elongation and poor branching of the ureteric buds were the likely causes of the kidney agenesis or hypoplasia. Furthermore, the lack of Isl1 reduced the expression of Bmp4, a gene implicated in the CAKUT-like phenotype, in the metanephric region before ureteric budding. In conclusion, Isl1 is essential for proper development of the kidney and ureter by repressing the aberrant formation of the ureteric bud. These observations call for further studies to investigate whether Isl1 may be a causative gene for human CAKUT.

negative: BCR/ABL oncogenic kinase promotes unfaithful repair of the reactive oxygen species-dependent DNA double-strand breaks. The oncogenic BCR/ABL tyrosine kinase induces constitutive DNA damage in Philadelphia chromosome (Ph)-positive leukemia cells. We find that BCR/ABL-induced reactive oxygen species (ROSs) cause chronic oxidative DNA damage resulting in double-strand breaks (DSBs) in S and G(2)/M cell cycle phases. These lesions are repaired by BCR/ABL-stimulated homologous recombination repair (HRR) and nonhomologous end-joining (NHEJ) mechanisms. A high mutation rate is detected in HRR products in BCR/ABL-positive cells, but not in the normal counterparts. In addition, large deletions are found in NHEJ products exclusively in BCR/ABL cells. We propose that the following series of events may contribute to genomic instability of Ph-positive leukemias: BCR/ABL --> ROSs --> oxidative DNA damage --> DSBs in proliferating cells --> unfaithful HRR and NHEJ repair.

negative: Haematopoietic stem cells and early lymphoid progenitors occupy distinct bone marrow niches Although haematopoietic stem cells (HSCs) are commonly assumed to reside within a specialized microenvironment, or niche, most published experimental manipulations of the HSC niche have affected the function of diverse restricted progenitors. This raises the fundamental question of whether HSCs and restricted progenitors reside within distinct, specialized niches or whether they share a common niche. Here we assess the physiological sources of the chemokine CXCL12 for HSC and restricted progenitor maintenance. Cxcl12(DsRed) knock-in mice (DsRed-Express2 recombined into the Cxcl12 locus) showed that Cxcl12 was primarily expressed by perivascular stromal cells and, at lower levels, by endothelial cells, osteoblasts and some haematopoietic cells. Conditional deletion of Cxcl12 from haematopoietic cells or nestin-cre-expressing cells had little or no effect on HSCs or restricted progenitors. Deletion of Cxcl12 from endothelial cells depleted HSCs but not myeloerythroid or lymphoid progenitors. Deletion of Cxcl12 from perivascular stromal cells depleted HSCs and certain restricted progenitors and mobilized these cells into circulation. Deletion of Cxcl12 from osteoblasts depleted certain early lymphoid progenitors but not HSCs or myeloerythroid progenitors, and did not mobilize these cells into circulation. Different stem and progenitor cells thus reside in distinct cellular niches in bone marrow: HSCs occupy a perivascular niche and early lymphoid progenitors occupy an endosteal niche.

negative: Markers of myocardial damage and inflammation in relation to long-term mortality in unstable coronary artery disease. FRISC Study Group. Fragmin during Instability in Coronary Artery Disease. BACKGROUND In patients with unstable coronary artery disease, there is a relation between the short-term risk of death and blood levels of troponin T (a marker of myocardial damage) and C-reactive protein and fibrinogen (markers of inflammation). Using information obtained during an extension of the follow-up period in the Fragmin during Instability in Coronary Artery Disease trial, we evaluated the usefulness of troponin T, C-reactive protein, and fibrinogen levels and other indicators of risk as predictors of the long-term risk of death from cardiac causes. METHODS Levels of C-reactive protein and fibrinogen at enrollment and the maximal level of troponin T during the first 24 hours after enrollment were analyzed in 917 patients included in a clinical trial of low-molecular-weight heparin in unstable coronary artery disease. The patients were followed for a mean of 37.0 months (range, 1.6 to 50.6). RESULTS During follow-up, 1.2 percent of the 173 patients with maximal blood troponin T levels of less than 0.06 microg per liter died of cardiac causes, as compared with 8.7 percent of the 367 patients with levels of 0.06 to 0.59 microg per liter and 15.4 percent of the 377 patients with levels of at least 0.60 microg per liter (P=0.007 and P=0.001, respectively). The rates of death from cardiac causes were 5.7 percent among the 314 patients with blood C-reactive protein levels of less than 2 mg per liter, 7.8 percent among the 294 with levels of 2 to 10 mg per liter, and 16.5 percent among the 309 with levels of more than 10 mg per liter (P=0.29 and P=0.001, respectively). The rates of death from cardiac causes were 5.4 percent among the 314 patients with blood fibrinogen levels of less than 3.4 g per liter, 12.0 percent among the 300 with levels of 3.4 to 3.9 g per liter, and 12.9 percent among the 303 with levels of at least 4.0 g per liter (P=0.004 and P=0.69, respectively). In a multivariate analysis, levels of troponin T and C-reactive protein were independent predictors of the risk of death from cardiac causes. CONCLUSIONS In unstable coronary artery disease, elevated levels of troponin T and C-reactive protein are strongly related to the long-term risk of death from cardiac causes. These markers are independent risk factors, and their effects are additive with respect to each other and other clinical indicators of risk.

negative: Bone progenitor dysfunction induces myelodysplasia and secondary leukemia Mesenchymal cells contribute to the 'stroma' of most normal and malignant tissues, with specific mesenchymal cells participating in the regulatory niches of stem cells. By examining how mesenchymal osteolineage cells modulate haematopoiesis, here we show that deletion of Dicer1 specifically in mouse osteoprogenitors, but not in mature osteoblasts, disrupts the integrity of haematopoiesis. Myelodysplasia resulted and acute myelogenous leukaemia emerged that had acquired several genetic abnormalities while having intact Dicer1. Examining gene expression altered in osteoprogenitors as a result of Dicer1 deletion showed reduced expression of Sbds, the gene mutated in Schwachman-Bodian-Diamond syndrome-a human bone marrow failure and leukaemia pre-disposition condition. Deletion of Sbds in mouse osteoprogenitors induced bone marrow dysfunction with myelodysplasia. Therefore, perturbation of specific mesenchymal subsets of stromal cells can disorder differentiation, proliferation and apoptosis of heterologous cells, and disrupt tissue homeostasis. Furthermore, primary stromal dysfunction can result in secondary neoplastic disease, supporting the concept of niche-induced oncogenesis.

negative: Coordinate regulation of the IL-4, IL-13, and IL-5 cytokine cluster in Th2 clones revealed by allelic expression patterns. The cytokines IL-4, IL-13, and IL-5 are markers for the Th2 subset of effector T cells and are often expressed together. These cytokine genes are organized within 140 kb of orthologous DNA in both mouse and human. Using IL-4-expressing CD4+ T cell clones derived from F1 mice, we identified allelic polymorphisms for each of these cytokines and assessed the parental identity of the cytokine mRNAs. Both monoallelic and biallelic expression occurred for each gene and for an additional gene, IL-3, that lies with GM-CSF over 450 kb telomeric on the same chromosome. When coexpressed in T cell clones, IL-4 was expressed from the same allele as IL-13 or IL-5 in 81% of instances. In contrast, there was only 52% concordance of these three cytokines at the allelic level among clones that expressed IL-3. Independent expression of the cytokine alleles occurs commonly in T cells, but the clustered locus encompassing IL-4, IL-13, and IL-5 is subject to coordinate regulation.

negative: Natural history of adult T-cell leukemia/lymphoma and approaches to therapy After cell-to-cell transmission, HTLV-I increases its viral genome by de novo infection and proliferation of infected cells. Proliferation of infected cells is clonal and persistent in vivo. During the carrier state, infected cells are selected in vivo by the host's immune system, the genetic and epigenetic environment of proviral integration sites, and other factors. In leukemic cells, tax gene expression is frequently impaired by genetic and epigenetic mechanisms. Such loss of Tax expression enables ATL cells to escape the host immune system. On the other hand, ATL cells acquire the ability to proliferate without Tax by intracellular genetic and epigenetic changes. Despite advances in support and the development of novel treatment agents, the prognosis for ATLL remains poor. A number of therapies, however, do appear to improve prognosis compared to CHOP (VEPA). These include interferon-α plus zidovudine (probably after 1–2 cycles of CHOP), intensive chemotherapy as in LSG-15 with G-CSF support and Allo-SCT (which includes the potential for cure). Emerging novel approaches include HDAC inhibitors, monoclonal antibodies, and proteasome inhibitors. Comparison between different therapeutic approaches is complicated by the range of natural history of ATLL, different recruitments of naïve-to-therapy, refractory or relapsed patients, and variations in the reporting of outcome that frequently excludes difficult-to-evaluate patients. Moreover, results from relatively small proof-of-principle studies have not been extended with randomized, controlled trials. As a result, currently, there is no clear evidence to support the value of any particular treatment approach over others. To avoid further unnecessary patient suffering and to identify optimal therapy as rapidly as possible, large randomized, controlled trials encompassing multicenter, international collaborations will be necessary.

negative: Rate and molecular spectrum of spontaneous mutations in the bacterium Escherichia coli as determined by whole-genome sequencing. Knowledge of the rate and nature of spontaneous mutation is fundamental to understanding evolutionary and molecular processes. In this report, we analyze spontaneous mutations accumulated over thousands of generations by wild-type Escherichia coli and a derivative defective in mismatch repair (MMR), the primary pathway for correcting replication errors. The major conclusions are (i) the mutation rate of a wild-type E. coli strain is ~1 × 10(-3) per genome per generation; (ii) mutations in the wild-type strain have the expected mutational bias for G:C > A:T mutations, but the bias changes to A:T > G:C mutations in the absence of MMR; (iii) during replication, A:T > G:C transitions preferentially occur with A templating the lagging strand and T templating the leading strand, whereas G:C > A:T transitions preferentially occur with C templating the lagging strand and G templating the leading strand; (iv) there is a strong bias for transition mutations to occur at 5'ApC3'/3'TpG5' sites (where bases 5'A and 3'T are mutated) and, to a lesser extent, at 5'GpC3'/3'CpG5' sites (where bases 5'G and 3'C are mutated); (v) although the rate of small (≤4 nt) insertions and deletions is high at repeat sequences, these events occur at only 1/10th the genomic rate of base-pair substitutions. MMR activity is genetically regulated, and bacteria isolated from nature often lack MMR capacity, suggesting that modulation of MMR can be adaptive. Thus, comparing results from the wild-type and MMR-defective strains may lead to a deeper understanding of factors that determine mutation rates and spectra, how these factors may differ among organisms, and how they may be shaped by environmental conditions.

negative: Ria1p (Ynl163c), a protein similar to elongation factors 2, is involved in the biogenesis of the 60S subunit of the ribosome in Saccharomyces cerevisiae RIA1 (YNL163c) is a quasi-essential gene that encodes a protein with strong similarities to elongation factors 2. Small C-terminal deletions in the protein lead to a severe growth defect. In the case of a 22-residue C-terminal deletion this can be suppressed by intragenic mutations in the RIA1 gene or dominant extragenic mutations in TIF6, which is thought to be involved in the biogenesis of the 60S subunit of the ribosome. The dominant TIF6 alleles can also suppress the phenotype associated with a complete deletion of the RIA1 gene. Depletion of Ria1p has a dramatic effect on the polysome profile: there is a severe reduction in the level of the 80S monosomes, an imbalance in the 40S/60S ratio, and halfmers appear. Dissociation of the monosomes and polysomes in the Ria1p depletion mutant revealed a specific reduction in the amount of 60S subunits. Localization experiments with HA-tagged derivatives of Ria1p did not detect any stable association of Ria1p with ribosome subunits, 80S monosomes or polysomes. Cell fractionation experiments show that Ria1p is found in both the cytoplasmic fraction and the nuclear fraction. Taken together, these data suggest that Ria1p is involved in the biogenesis of the 60S subunit of the ribosome.

negative: PTEN Regulates PI(3,4)P2 Signaling Downstream of Class I PI3K The PI3K signaling pathway regulates cell growth and movement and is heavily mutated in cancer. Class I PI3Ks synthesize the lipid messenger PI(3,4,5)P3. PI(3,4,5)P3 can be dephosphorylated by 3- or 5-phosphatases, the latter producing PI(3,4)P2. The PTEN tumor suppressor is thought to function primarily as a PI(3,4,5)P3 3-phosphatase, limiting activation of this pathway. Here we show that PTEN also functions as a PI(3,4)P2 3-phosphatase, both in vitro and in vivo. PTEN is a major PI(3,4)P2 phosphatase in Mcf10a cytosol, and loss of PTEN and INPP4B, a known PI(3,4)P2 4-phosphatase, leads to synergistic accumulation of PI(3,4)P2, which correlated with increased invadopodia in epidermal growth factor (EGF)-stimulated cells. PTEN deletion increased PI(3,4)P2 levels in a mouse model of prostate cancer, and it inversely correlated with PI(3,4)P2 levels across several EGF-stimulated prostate and breast cancer lines. These results point to a role for PI(3,4)P2 in the phenotype caused by loss-of-function mutations or deletions in PTEN.

negative: Rps14 haploinsufficiency causes a block in erythroid differentiation mediated by S100A8 and S100A9 Impaired erythropoiesis in the deletion 5q (del(5q)) subtype of myelodysplastic syndrome (MDS) has been linked to heterozygous deletion of RPS14, which encodes the ribosomal protein small subunit 14. We generated mice with conditional inactivation of Rps14 and demonstrated an erythroid differentiation defect that is dependent on the tumor suppressor protein p53 (encoded by Trp53 in mice) and is characterized by apoptosis at the transition from polychromatic to orthochromatic erythroblasts. This defect resulted in age-dependent progressive anemia, megakaryocyte dysplasia and loss of hematopoietic stem cell (HSC) quiescence. As assessed by quantitative proteomics, mutant erythroblasts expressed higher levels of proteins involved in innate immune signaling, notably the heterodimeric S100 calcium-binding proteins S100a8 and S100a9. S100a8—whose expression was increased in mutant erythroblasts, monocytes and macrophages—is functionally involved in the erythroid defect caused by the Rps14 deletion, as addition of recombinant S100a8 was sufficient to induce a differentiation defect in wild-type erythroid cells, and genetic inactivation of S100a8 expression rescued the erythroid differentiation defect of Rps14-haploinsufficient HSCs. Our data link Rps14 haploinsufficiency in del(5q) MDS to activation of the innate immune system and induction of S100A8-S100A9 expression, leading to a p53-dependent erythroid differentiation defect.

negative: Doxycycline induces apoptosis in PANC-1 pancreatic cancer cells. BACKGROUND Tetracyclines such as doxycycline are reported to possess cytotoxic activity against mammalian tumor cells, but the mechanism of their effects on cell proliferation remains unclear. MATERIALS AND METHODS The antitumor effect of doxycycline was investigated in human pancreatic cancer cell line, PANC-1. We also investigated the effect of doxycycline on expression of a potent proangiogenic factor, interleukin (IL)-8. RESULTS In excess of 20 microg/ml, cytotoxic effects of doxycycline were accompanied by G(1)-S cell cycle arrest and DNA fragmentation in PANC-1 cells. Doxycycline consistently activated transcription of p53, p21 and Fas/FasL-cascade-related genes, while reducing the expression of Bcl-xL and Mcl-1. Doxycycline (5 microg/ml) below the cytotoxic level suppressed endogenous and paclitaxel-induced IL-8 expression. In the mouse xenograft model, doxycycline treatment was shown to suppress tumor growth by 80%. CONCLUSION These data suggest that doxycycline exerts its antitumor effect by activating proapoptotic genes, inhibiting IL-8 expression, and suppressing antiapoptotic genes.