246 research outputs found
Electrophysiology of the Olivo-Cerebellar Loop
In animals, motor function and muscle control are critical for an organisms ability
to interact with and react to its environment. This behavior can have many different
functions, from finding food to defending themselves against enemies. In general,
we can subdivide movements into two categories: 1) involuntary movements, like
reflexes, and 2) voluntary movements. From an evolutionary point of view, the more
efficient these movements are, the higher the chance of survival. In vertebrates, the
cerebellum controls movement and monitors its efficiency by collecting sensory information,
such as limb position, balance information and vision. All this information
is evaluated to control and correct our intended movements . The cerebellum
is located just above the brainstem at the lower back of the brain. In humans, it is
the size of a fist and has a very high nerve cell (neuron) density. The outer layer of
the cerebellum, also known as the cerebellar cortex, consists of grey matter and the
inner layer consists of white matter. The neurons in the cerebellum are arranged in
remarkably homogeneous and repetitive structural patterns with little variation in
organization across species
BCR-ABL1 tyrosine kinase sustained MECOM expression in chronic myeloid leukaemia
MECOM oncogene expression correlates with chronic myeloid leukaemia (CML) progression. Here we show that the knockdown of MECOM (E) and MECOM (ME) isoforms reduces cell division at low cell density, inhibits colony-forming cells by 34% and moderately reduces BCR-ABL1 mRNA and protein expression but not tyrosine kinase catalytic activity in K562 cells. We also show that both E and ME are expressed in CD34<sup>+</sup> selected cells of both CML chronic phase (CML-CP), and non-CML (normal) origin. Furthermore, MECOM mRNA and protein expression were repressed by imatinib mesylate treatment of CML-CP CD34<sup>+</sup> cells, K562 and KY01 cell lines whereas imatinib had no effect in non-CML BCR-ABL1 −ve CD34<sup>+</sup> cells. Together these results suggest that BCR-ABL1 tyrosine kinase catalytic activity regulates MECOM gene expression in CML-CP progenitor cells and that the BCR-ABL1 oncoprotein partially mediates its biological activity through MECOM. MECOM gene expression in CML-CP progenitor cells would provide an in vivo selective advantage, contributing to CML pathogenesis
Plag1 and Plagl2 are oncogenes that induce acute myeloid leukemia in cooperation with Cbfb-MYH11
Recurrent chromosomal rearrangements are associated with the development of acute myeloid leukemia (AML). The frequent inversion of chromosome 16 creates the CBFB-MYH11 fusion gene that encodes the fusion protein CBFbeta-SMMHC. This fusion protein inhibits the core-binding factor (CBF), resulting in a block of hematopoietic differentiation, and induces leukemia upon the acquisition of additional mutations. A recent genetic screen identified Plag1 and Plagl2 as CBF beta-SMMHC candidate cooperating proteins. In this study, we demonstrate that Plag1 and Plagl2 independently cooperate with CBF beta-SMMHC in vivo to efficiently trigger leukemia with short latency in the mouse. In addition, Plag1 and Plagl2 increased proliferation by inducing G1 to S transition that resulted in the expansion of hematopoietic progenitors and increased cell renewal in vitro. Finally, PLAG1 and PLAGL2 expression was increased in 20% of human AML samples. Interestingly, PLAGL2 was preferentially increased in samples with chromosome 16 inversion, suggesting that PLAG1 and PLAGL2 may also contribute to human AML. Overall, this study shows that Plag1 and Plagl2 are novel leukemia oncogenes that act by expanding hematopoietic progenitors expressing CbF beta-SMMHC
The evaluation of input costs contribution to sturgeon fish farming in 2006 in Iran
Culture of sturgeon species is of great economic and ecological importance for those countries such as Iran whose natural stocks have declined. This species has shown a good growth performance in many types of production systems and in tanks with different sizes. Recently, sturgeon species is also offering good prospects for aquaculture in north of Iran, including: Guilan, Mazandaran and Golestan provinces. Several species of sturgeon are now considered attractive candidates for whole-cycle production in Iran. Production analysis may help manager of a sturgeon farm in decision making and in adjusting to changes. Economic assessment provides a basis not only for decision making among farm managers but also for formulating government aquaculture policies. Over the period 2006, based on previous experiments with cultured cam, shrimp and trout farming, total costs, total income, profitability and the contribution of production costs for sturgeon farming were determined by completing questionnaires. Among the various expenditures in the year 2006, labor costs had the greatest share and averaged 25% of the total costs. Feed costs averaged more than 17% of the Costs and fingerling costs averaged 10% of the costs. Results show, on average, total cost per kg production of sturgeon was IR Rials 40,587 (US 7.57), and profitability per kg production of sturgeon meat also averaged IR Rials 27,944 (US$ 3.11). The results suggest that farmers are doing more efficiently and have better conditions in Mazandaran, resulting in higher farm income per kg, followed by Guilan province
Histology independent drug development - Is this the future for cancer drugs?
The Cancer Drug Development Forum (CDDF)’s ‘Histology independent drug development – is this the future for cancer drugs?’ workshop was set up to explore the current landscape of histology independent drug development, review the current regulatory landscape and propose recommendations for improving the conduct of future trials.The first session considered lessons learnt from previous trials, including innovative solutions for reimbursement. The session explored why overall survival represents the most valuable endpoint, and the importance of duration of response, which can be captured with swimmer and spider plots.The second session on biomarker development and treatment optimisation considered current regulations for companion diagnostics, FDA guidance on histology independent drug development in oncology, and the need to establish cut-offs for the biomarker of tumour mutational burden to identify the patients most likely to benefit from PDL1 treatment.The third session reviewed novel trial designs, including basket, umbrella and platform trials, and statistical approaches of hierarchical modelling where homogeneity between study cohorts enables information to be borrowed between cohorts. The discussion highlighted the need to agree ‘common assessment standards’ to facilitate pooling of data across studies.In the fourth session, the sharing of data sets was recognised as a key step for improving equity of access to precision medicines across Europe. The session considered how the European Health Data Space (EHDS) could streamline access to medical records, emphasizing the importance of introducing greater accountability into the digital space.In conclusion the workshop proposed 11 recommendations to facilitate histology agnostic drug development.</p
Prognostically useful gene-expression profiles in acute myeloid leukemia
BACKGROUND: In patients with acute myeloid leukemia (AML) a combination of
methods must be used to classify the disease, make therapeutic decisions,
and determine the prognosis. However, this combined approach provides
correct therapeutic and prognostic information in only 50 percent of
cases. METHODS: We determined the gene-expression profiles in samples of
peripheral blood or bone marrow from 285 patients with AML using
Affymetrix U133A GeneChips containing approximately 13,000 unique genes or
expression-signature tags. Data analyses were carried out with Omniviz,
significance analysis of microarrays, and prediction analysis of
microarrays software. Statistical analyses were performed to determine the
prognostic significance of cases of AML with specific molecular
signatures. RESULTS: Unsupervised cluster analyses identified 16 groups of
patients with AML on the basis of molecular signatures. We identified the
genes that defined these clusters and determined the minimal numbers of
genes needed to identify prognostically important clusters with a high
degree of accuracy. The clustering was driven by the presence of
chromosomal lesions (e.g., t(8;21), t(15;17), and inv(16)), particular
genetic mutations (CEBPA), and abnormal oncogene expression (EVI1). We
identified several novel clusters, some consisting of specimens with
normal karyotypes. A unique cluster with a distinctive gene-expression
signature included cases of AML with a poor treatment outcome.
CONCLUSIONS: Gene-expression profiling allows a comprehensive
classification of AML that includes previously identified genetically
defined subgroups and a novel cluster with an adverse prognosis
Novel Mutations in CEBPA in Korean Patients with Acute Myeloid Leukemia with a Normal Karyotype
Mutations in the transcription factor CCAAT/enhancer binding protein α gene (CEBPA) are found in 5-14% of the patients with AML and have been associated with a favorable clinical outcome. In this study, we aimed to assess the frequencies and characteristics of mutations in CEBPA. Between 2006 and 2009, CEBPA mutations were assessed using archival DNA samples obtained from 30 consecutive adult patients diagnosed with AML with a normal karyotype at our institution. CEBPA mutations were detected using direct sequencing analyses. These mutations were detected and described with reference to GenBank Accession No. NM_004364.3. In our series, CEBPA mutations were detected in 4 patients (13.3%). These mutations occurred as double mutations in all 4 patients. Among the 8 mutant alleles, 5 were novel (c.179_180dupCG, c.50_53delGCCA, c.178_182delACGTinsTTT, c.243_244insGTCG, and c.923_924insCTC). The frequency of occurrence of CEBPA mutations in Korean patients with AML is comparable to that in previous reports. Long-term follow-up data from a larger series of patients with comprehensive molecular profiling are needed to delineate the prognostic implications
Double CEBPA mutations, but not single CEBPA mutations, define a subgroup of acute myeloid leukemia with a distinctive gene expression profile that is uniquely associated with a favorable outcome
Mutations in CCAAT/enhancer binding protein α (CEBPA) are seen in 5% to 14% of acute myeloid leukemia (AML) and have been associated with a favorable clinical outcome. Most AMLs with CEBPA mutations simultaneously carry 2 mutations (CEBPAdouble-mut), usually biallelic, whereas single heterozygous mutations (CEBPAsingle-mut) are less frequently seen. Using denaturing high-performance liquid chromatography and nucleotide sequencing, we identified among a cohort of 598 newly diagnosed AMLs a subset of 41 CEBPA mutant cases (28 CEBPAdouble-mut and 13 CEBPA single-mut cases) CEBPAdouble-mut associated with a unique gene expression profile as well as favorable overall and event-free survival, retained in multi-variable analysis that included cytoge-netic risk, FZT3-ITD and NPM1 mutation, white blood cell count, and age. In contrast, CEBPA single-mut AMLs did not express a discriminating signature and could not be distinguished from wild-type cases as regards clinical outcome. These results demonstrate significant underlying heterogeneity within CEBPA mutation-positive AML with prognostic relevance
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