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We report first results on elliptic flow of identified particles at midrapidity in Au+Au collisions at sqrt[sNN] = 130 GeV using the STAR TPC at RHIC. The elliptic flow as a function of transverse momentum and centrality differs significantly for particles of different masses. This dependence can be accounted for in hydrodynamic models, indicating that the system created shows a behavior consistent with collective hydrodynamical flow. The fit to the data with a simple model gives information on the temperature and flow velocities at freeze-out.
The minimum-bias multiplicity distribution and the transverse momentum and pseudorapidity distributions for central collisions have been measured for negative hadrons ( h-) in Au+Au interactions at sqrt[sNN] = 130 GeV. The multiplicity density at midrapidity for the 5% most central interactions is dNh-/d eta | eta = 0 = 280±1(stat)±20(syst), an increase per participant of 38% relative to pp-bar collisions at the same energy. The mean transverse momentum is 0.508±0.012 GeV/c and is larger than in central Pb+Pb collisions at lower energies. The scaling of the h- yield per participant is a strong function of pperp. The pseudorapidity distribution is almost constant within | eta |<1.
We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at sqrt[sNN] = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25<pperp<0.95 GeV/c are found to fall less steeply for more central collisions. The extrapolated antiproton rapidity density is found to scale approximately with the negative hadron multiplicity density.
We report results on the ratio of midrapidity antiproton-to-proton yields in Au+Au collisions at sqrt[sNN] = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of | y|<0.5 and 0.4<pt<1.0 GeV/c, the ratio is essentially independent of either transverse momentum or rapidity, with an average of 0.65±0.01(stat)±0.07(syst) for minimum bias collisions. Within errors, no strong centrality dependence is observed. The results indicate that at this RHIC energy, although the p-p-bar pair production becomes important at midrapidity, a significant excess of baryons over antibaryons is still present.
Acute myeloid/lymphoid leukemia is a fatal hematological malignancy characterized by accumulation of nonfunctional, immature blasts, which interferes with the production of normal blood cells. Activating mutations of receptor tyrosine kinases are common genetic lesions in leukemia. FLT3-ITD is a frequent activating mutation found in AML patients, leading to uncontrolled proliferation of leukemic blasts. FLT3-ITD directly activates STAT5, leading to the induction of STAT5 target gene expression like PIM kinases and SOCS genes. STAT5 and PIM kinases have been shown to play a crucial role in the FLT3-ITD mediated transformation. On the other hand, the role of SOCS proteins in FLT3-ITD mediated transformation has not been studied to date. SOCS proteins are part of a negative feedback mechanism that controls Jak kinases downstream of cytokine receptors. One of the SOCS family members, SOCS1 has been reported to suppress oncogenecity of several activating kinases implicated in hematologic malignancies. In this thesis the role of these SOCS proteins in FLT3-ITD mediated transformation (in vitro) and leukemogenesis (in vivo) is systematically explored. Expression of FLT3-ITD in cell lines of myeloid (32D) and lymphoid (Ba/F3) origin, led to CIS, SOCS1 and SOCS2 expression. FLT3-ITD expression in primary murine bone marrow stem/progenitor cells led to a 59 fold induction of SOCS1 expression. Furthermore, FLT3-ITD positive AML cell lines (MV4-11, MOLM-13) show kinase dependent CIS, SOCS1, and SOCS3 expression. Importantly SOCS1 is highly expressed in AML patients with FLT3-ITD compared to healthy individuals. SOCS1 protein was expressed in FLT3-ITD transduced murine bone marrow stem cells and SOCS1 expression was abolished with kinase inhibition in MOLM-13 cell line. In conclusion, SOCS1 was highly regulated by FLT3-ITD in myeloid, lymphoid cell lines, in bone marrow stem/progenitors and in AML patient samples. SOCS1 co-expression did not affect FLT3-ITD mediated signaling and proliferation, but abolished IL-3 mediated proliferation and protected 32D cells from interferon-α and interferon-γ mediated growth inhibition. FLT3-ITD expressing 32D cells showed diminished STAT1 activation in response to interferons (α and γ). Alone, SOCS1 strongly inhibited cytokine induced colony formation of bone marrow stem and progenitors, but not FLT3-ITD induced colony formation. Most importantly, in the presence of growth inhibitory interferon-γ, SOCS1 co-expression with FLT3-ITD led to increased colony formation compared to FLT3-ITD alone. Taken together, FLT3-ITD induced and exogenously expressed SOCS1, shielded cells from external cytokines, signals, while not affecting FLT3-ITD induced proliferation/signaling. In further experiments the in vivo effects of SOCS1 were studied in a bone marrow transplantation model. SOCS1 bone marrow transplants were unable to engraft/proliferate in mice. FLT3-ITD was shown to induce a myeloproliferative disease. Both control (empty vector), SOCS1 transplanted mice were normal and did not show any disease phenotype. FLT3-ITD alone and SOCS1 co-expressing FLT3-ITD developed either myeloproliferative disease or acute lymphoblastic leukemia with equal distribution. SOCS1 co-expression with FLT3-ITD led to a decreased latency. Mice transplanted with FLT3-ITD alone and SOCS1 co-expressing FLT3-ITD displayed enlarged spleens, liver and hypercellular bone marrow indicating infiltration of leukemic cells. Mice were also anemic and showed decreased platelet counts. Importantly SOCS1 co-expression particularly shortened the latency of myeloproliferative disease but not of acute lymphoblastic leukemia. In summary, in the context of FLT3-ITD, SOCS1 acts as a ‘conditional oncogene’ and cooperates with FLT3-ITD in the development of myeloproliferative disease. With these data we propose the following model: FLT3-ITD induces SOCS gene expression, which shields cells against proliferation and differentiation signals from cytokines, while not affecting FLT3-ITD mediated proliferative signals. This leaves cells under the dictate of FLT3-ITD thereby contributing to leukemogenesis. Similar to FLT3-ITD, BCR/ABL (P190) (an oncogenic fusion kinase often found in acute lymphoblastic leukemia) induces SOCS gene expression in K562 and long-term cultured cells from patients with acute lymphoblastic leukemia. SOCS1 co-expression does not affect BCR/ABL mediated proliferation while abrogating IL-3 mediated proliferation. These findings suggest that SOCS proteins may play a general co-operative role in the context of oncogenes which aberrantly activate STAT3/5 independently of JAK kinases. This study reveals a novel molecular mechanism of FLT3-ITD mediated leukemogenesis and suggests SOCS genes as potential therapeutic targets.
Treatment with tyrosine kinase inhibitors is the standard of care for Philadelphia chromosome positive leukemias. However the eradication of leukemia initiating cells remains a challenge. Circumstantial evidence suggests that the cytokine microenvironment may play a role in BCR-ABL mediated leukemogenesis and in imatinib resistance. Gene expression analyses of BCR-ABL positive ALL long-term cultured cells revealed strong reduction of SOCS mRNA expression after imatinib treatment, thereby demonstrating a strong inhibition of cytokine signaling. In this study we employed SOCS1—a strong inhibitor of cytokine signaling—as a tool to terminate external cytokine signals in BCR-ABL transformed cells in vitro and in vivo. In colony formation assays with primary bone marrow cells, expression of SOCS1 decreased colony numbers under pro-proliferative cytokines, while it conferred growth resistance to anti-proliferative cytokines. Importantly, co-expression of SOCS1 with BCR-ABL led to the development of a MPD phenotype with a prolonged disease latency compared to BCR-ABL alone in a murine bone marrow transplantation model. Interestingly, SOCS1 co-expression protected 20% of mice from MPD development. In summary, we conclude that under pro-proliferative cytokine stimulation at the onset of myeloproliferative diseases SOCS1 acts as a tumor suppressor, while under anti-proliferative conditions it exerts oncogenic function. Therefore SOCS1 can promote opposing functions depending on the cytokine environment.
Background: Candida spp. are a frequent cause of nosocomial bloodstream infections worldwide.
Objective: To evaluate the use patterns and outcomes associated with intravenous (IV) fluconazole therapy in intensive care units in Spain and Germany.
Patients and methods: The research reported here was a prospective multicenter longitudinal observational study in adult intensive care unit patients receiving IV fluconazole. Demographic, microbiologic, therapy success, length of hospital stay, adverse event, and all-cause mortality data were collected at 14 sites in Spain and five in Germany, from February 2004 to November 2005.
Results: Patients (n = 303) received prophylaxis (n = 29), empiric therapy (n = 140), preemptive therapy (n = 85), or definitive therapy (n = 49). A total of 298 patients (98.4%) were treated with IV fluconazole as first-line therapy. The treating physicians judged therapy successful in 66% of prophylactic, 55% of empiric, 45% of preemptive, and 43% of definitive group patients. In the subgroup of 152 patients with proven and specified Candida infection only, 32% suffered from Candida specified as potentially resistant to IV fluconazole. The overall mortality rate was 42%.
Conclusion: Our study informs treatment decision makers that approximately 32% of the patients with microbiological results available suffered from Candida specified as potentially resistant to IV fluconazole, highlighting the importance of appropriate therapy.
The taxonomic status of the nominal taxon Dryophis prasinus flavescens Wall, 1910 is reevaluated herein. Based on molecular data generated from fresh collections of Ahaetulla prasina (H. Boie in F. Boie, 1827) auctorum from Northeast India and, additionally, morphological data from museum specimens originating from the same areas, we resurrect this taxon as Ahaetulla flavescens (Wall, 1910) comb. nov. We clarify the status, identity and locations of its type specimens, rediscover, redescribe and illustrate those specimens and also designate a lectotype in order to effect a proper taxonomic redefinition of this nominal taxon. We provide further details on the morphology and diagnosis of this species and elucidate its phylogenetic position. We also provide a summary of the natural history and distribution of this species. Adding to the known cryptic diversity and genetic divergence within Southeast Asian populations, this work also hints at the need for a taxonomic revision of the A. prasina complex. This work complements a previous study on the A. prasina complex focusing on populations in Indonesia. Taken together, these two studies represent phylogenetic reconstructions from different populations of the A. prasina complex across its distribution range, on the Asian mainland and the surrounding islands.
Bipolar disorder (BD) is a genetically complex mental illness characterized by severe oscillations of mood and behavior. Genome-wide association studies (GWAS) have identified several risk loci that together account for a small portion of the heritability. To identify additional risk loci, we performed a two-stage meta-analysis of >9 million genetic variants in 9,784 bipolar disorder patients and 30,471 controls, the largest GWAS of BD to date. In this study, to increase power we used ~2,000 lithium-treated cases with a long-term diagnosis of BD from the Consortium on Lithium Genetics, excess controls, and analytic methods optimized for markers on the Xchromosome. In addition to four known loci, results revealed genome-wide significant associations at two novel loci: an intergenic region on 9p21.3 (rs12553324, p = 5.87×10-9; odds ratio = 1.12) and markers within ERBB2 (rs2517959, p = 4.53×10-9; odds ratio = 1.13). No significant X-chromosome associations were detected and X-linked markers explained very little BD heritability. The results add to a growing list of common autosomal variants involved in BD and illustrate the power of comparing well-characterized cases to an excess of controls in GWAS.