208 research outputs found
Editorial : Emergence and re-emergence of plant diseases caused by Xanthomonas species
No abstract available.https://www.frontiersin.org/journals/microbiologyam2023BiochemistryGeneticsMicrobiology and Plant Patholog
Metastatic Medulloblastoma in Childhood: Chang's Classification Revisited
Purpose. To correlate the radiological aspects of metastases, the response to chemotherapy, and patient outcome in disseminated childhood medulloblastoma.
Patients and Methods. This population-based study concerned 117 newly diagnosed children with disseminated medulloblastoma treated at the Institute Gustave Roussy between 1988 and 2008. Metastatic disease was assessed using the Chang staging system, their form (positive cerebrospinal fluid (CSF), nodular or laminar), and their extension (positive cerebrospinal fluid, local, extensive). All patients received preirradiation chemotherapy.
Results. The overall survival did not differ according to Chang M-stage. The 5-year overall survival was 59% in patients with nodular metastases compared to 35% in those with laminar metastases. The 5-year overall survival was 76% in patients without disease at the end of pre-irradiation chemotherapy compared to 34% in those without a complete response (P = 0.0008). Conclusions. Radiological characteristics of metastases correlated with survival in patients with medulloblastoma. Complete response to sandwich chemotherapy was a strong predictor of survival
ESKIMO1 is a key gene involved in water economy as well as cold acclimation and salt tolerance
<p>Abstract</p> <p>Background</p> <p>Drought is a major social and economic problem resulting in huge yield reduction in the field. Today's challenge is to develop plants with reduced water requirements and stable yields in fluctuating environmental conditions. <it>Arabidopsis thaliana </it>is an excellent model for identifying potential targets for plant breeding. Drought tolerance in the field was successfully conferred to crops by transferring genes from this model species. While involved in a plant genomics programme, which aims to identify new genes responsible for plant response to abiotic stress, we identified <it>ESKIMO1 </it>as a key gene involved in plant water economy as well as cold acclimation and salt tolerance.</p> <p>Results</p> <p>All <it>esk1 </it>mutants were more tolerant to freezing, after acclimation, than their wild type counterpart. <it>esk1 </it>mutants also showed increased tolerance to mild water deficit for all traits measured. The mutant's improved tolerance to reduced water supply may be explained by its lower transpiration rate and better water use efficiency (WUE), which was assessed by carbon isotope discrimination and gas exchange measurements. <it>esk1 </it>alleles were also shown to be more tolerant to salt stress.</p> <p>Transcriptomic analysis of one mutant line and its wild-type background was carried out. Under control watering conditions a number of genes were differentially expressed between the mutant and the wild type whereas under mild drought stress this list of genes was reduced. Among the genes that were differentially expressed between the wild type and mutant, two functional categories related to the response to stress or biotic and abiotic stimulus were over-represented. Under salt stress conditions, all gene functional categories were represented equally in both the mutant and wild type. Based on this transcriptome analysis we hypothesise that in control conditions the <it>esk1 </it>mutant behaves as if it was exposed to drought stress.</p> <p>Conclusion</p> <p>Overall our findings suggest that the <it>ESKIMO1 </it>gene plays a major role in plant response to water shortage and in whole plant water economy. Further experiments are being undertaken to elucidate the function of the ESKIMO1 protein and the way it modulates plant water uptake.</p
MOL#8268 1 Title Page. The natural mutation encoding a C-terminus truncated 5-HT 2B receptor is a gain of proliferative functions
Number of tables, 1 Number of references, 31 Number of words in the abstract, 230 Number of words in the Introduction, 744 Number of words in the Discussion. 1172 List of non-standard abbreviations receptor was identified in one patient diagnosed with pulmonary hypertension after intake of the anorexigen dexfenfluramine. Although reported to generate a lack of function, this C-terminus truncated 5-HT 2B receptor should somehow affect transduction pathways relevant to pulmonary hypertension. In our study, we investigated putative modifications in transduction of the R393X mutated 5-HT 2B receptor. In stably transfected cells, we confirmed the loss of IP 3 stimulation due to the G αq uncoupling, despite conserved ligand affinity between the normal and mutated receptors. We also observed a partial loss of nitric oxide synthase stimulation. However, the truncated R393X receptor presented (i) a strong gain of efficacy in cell proliferation as assessed by mitogen-activated protein kinase activity and thymidine incorporation, (ii) a preferential coupling to G α13 as shown by blocking antiserum, and (iii) an apparent lack of internalization upon agonist stimulation as observed by confocal microscopy. This work demonstrates that, in the 5-HT 2B receptor, the C-terminus including the palmitoylation and phosphorylation sites is absolutely required for proper transduction and internalization. For the first time, we show that the lack of C-terminus can generate a switch of coupling to G α13 , a reduced NO synthase activation and an increase in cell proliferation. All these modifications are relevant in pathophysiological vasoconstriction. MOL#8268 4 Introduction
Mutations in components of complement influence the outcome of Factor I-associated atypical hemolytic uremic syndrome
Genetic studies have shown that mutations of complement inhibitors such as membrane cofactor protein, Factors H, I, or B and C3 predispose patients to atypical hemolytic uremic syndrome (aHUS). Factor I is a circulating serine protease that inhibits complement by degrading C3b and up to now only a few mutations in the CFI gene have been characterized. In a large cohort of 202 patients with aHUS, we identified 23 patients carrying exonic mutations in CFI. Their overall clinical outcome was unfavorable, as half died or developed end-stage renal disease after their first syndrome episode. Eight patients with CFI mutations carried at least one additional known genetic risk factor for aHUS, such as a mutation in MCP, CFH, C3 or CFB; a compound heterozygous second mutation in CFI; or mutations in both the MCP and CFH genes. Five patients exhibited homozygous deletion of the Factor H-related protein 1 (CFHR-1) gene. Ten patients with aHUS had one mutation in their CFI gene (Factor I-aHUS), resulting in a quantitative or functional Factor I deficiency. Patients with a complete deletion of the CFHR-1 gene had a significantly higher risk of a bad prognosis compared with those with one Factor I mutation as their unique vulnerability feature. Our results emphasize the necessity of genetic screening for all susceptibility factors in patients with aHUS
Somatostatin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
Somatostatin (somatotropin release inhibiting factor) is an abundant neuropeptide, which acts on five subtypes of somatostatin receptor (SST1-SST5; nomenclature as agreed by the NC-IUPHAR Subcommittee on Somatostatin Receptors [89]). Activation of these receptors produces a wide range of physiological effects throughout the body including the inhibition of secretion of many hormones. Endogenous ligands for these receptors are somatostatin-14 (SRIF-14) and somatostatin-28 (SRIF-28). cortistatin-14 has also been suggested to be an endogenous ligand for somatostatin receptors [56]
Somatostatin receptors in GtoPdb v.2023.1
Somatostatin (somatotropin release inhibiting factor) is an abundant neuropeptide, which acts on five subtypes of somatostatin receptor (SST1-SST5; nomenclature as agreed by the NC-IUPHAR Subcommittee on Somatostatin Receptors [98]). Activation of these receptors produces a wide range of physiological effects throughout the body including the inhibition of secretion of many hormones. Endogenous ligands for these receptors are somatostatin-14 (SRIF-14) and somatostatin-28 (SRIF-28). cortistatin-14 has also been suggested to be an endogenous ligand for somatostatin receptors [61]
An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers
Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe
Genome-wide association study identifies 32 novel breast cancer susceptibility loci from overall and subtype-specific analyses.
Breast cancer susceptibility variants frequently show heterogeneity in associations by tumor subtype1-3. To identify novel loci, we performed a genome-wide association study including 133,384 breast cancer cases and 113,789 controls, plus 18,908 BRCA1 mutation carriers (9,414 with breast cancer) of European ancestry, using both standard and novel methodologies that account for underlying tumor heterogeneity by estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 status and tumor grade. We identified 32 novel susceptibility loci (P < 5.0 × 10-8), 15 of which showed evidence for associations with at least one tumor feature (false discovery rate < 0.05). Five loci showed associations (P < 0.05) in opposite directions between luminal and non-luminal subtypes. In silico analyses showed that these five loci contained cell-specific enhancers that differed between normal luminal and basal mammary cells. The genetic correlations between five intrinsic-like subtypes ranged from 0.35 to 0.80. The proportion of genome-wide chip heritability explained by all known susceptibility loci was 54.2% for luminal A-like disease and 37.6% for triple-negative disease. The odds ratios of polygenic risk scores, which included 330 variants, for the highest 1% of quantiles compared with middle quantiles were 5.63 and 3.02 for luminal A-like and triple-negative disease, respectively. These findings provide an improved understanding of genetic predisposition to breast cancer subtypes and will inform the development of subtype-specific polygenic risk scores
Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders
Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe
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