378 research outputs found

    Nkx2.1 regulates the proliferation and cell fate of telencephalic astrocytes during embryonic development

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    AbstractThe homeodomain transcription factor Nkx2.1 controls cell differentiation of telencephalic GABAergic interneurons and oligodendrocytes. Here, we show that Nkx2.1 additionally regulates astrogliogenesis of the telencephalon from embryonic day (E) 14.5 to E16.5. Our work aims to identify the different mechanisms by which Nkx2.1 controls telencephalic astrogliogenesis. InNkx2.1-/-, a drastic loss of astrocytes is observed which is not related to cell death.In vivoanalysis using BrdU incorporation reveals that Nkx2.1 affects the proliferation of ventral neural stem cells that generate early astrocytes.In vitroneurosphere assays show that Nkx2.1 additionally affects the differentiation step of Nkx2.1-derived astrocytes. Chromatin immunoprecipitation andin vitroco-transfection studies of a Nkx2.1-expressing plasmid indicate that Nkx2.1 binds to the promoter of astroglial differentiation gene GFAP, and regulates its expression. Hence, Nkx2.1 controls astroglial production spatiotemporally in embryos by regulating stem cell division and specification of the contributing Nkx2.1+precursors.</jats:p

    Cell wall degrading enzymes originating from rhizoctonia solani increase sugar beet root damage in the presence of leuconostoc mesenteroides

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    Sugar beet crown and root rot caused by Rhizoctonia solani is a major yield constraint. Root rot is highly increased when R. solani and Leuconostoc mesenteroides co-infect roots. We hypothesized that the absence of plant cell wall degrading enzymes in L. mesenteroides and their supply by R. solani during close contact, causes increased damage. In planta root inoculation with or without cell wall degrading enzymes showed greater rot when L. mesenteroides was combined with cellulase (49 mm rot), polygalacturonase (48 mm), and pectin lyase (35 mm) versus these enzymes (0–11 mm), R. solani (13 mm), and L. mesenteroides (22 mm) individually. Carbohydrate analysis revealed increase in simpler carbohydrates namely glucose + galactose, and fructose in the infected roots versus mock control, possibly due to the degradation of complex cell wall carbohydrates. Expression of R. solani cellulase, polygalacturonase, and pectin lyase genes during root infection corroborated well with the enzyme data. Global mRNAseq analysis identified candidate genes and highly co-expressed gene clusters (in all 3 organisms) that might be critical in host plant defense and pathogenesis. Future targeting of R. solani cell wall degrading enzymes could be an effective strategy to mitigate root damage during interaction with L. mesenteroides

    Incidence of necrotising enterocolitis before and after introducing routine prophylactic Lactobacillus and Bifidobacterium probiotics

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    Objective: To compare rates of necrotising enterocolitis (NEC), late-onset sepsis, and mortality in 5-year epochs before and after implementation of routine daily multistrain probiotics administration in high-risk neonates. Design: Single-centre retrospective observational study over the 10-year period from 1 January 2008 to 31 December 2017. Setting: Level 3 neonatal intensive care unit (NICU) of the Norfolk and Norwich University Hospital, UK. Patients: Preterm neonates at high risk of NEC: Admitted to NICU within 3 days of birth at <32 weeks' gestation or at 32-36 weeks' gestation and of birth weight <1500 g. Intervention: Prior to 1 January 2013 probiotics were not used. Thereafter, dual-species Lactobacillus acidophilus and Bifidobacterium bifidum combination probiotics were routinely administered daily to high-risk neonates; from April 2016 triple-species probiotics (L.acidophilus,B.bifidum, and B.longum subspecies infantis) were used. Main outcome measures: Incidence of NEC (modified Bell's stage 2a or greater), late-onset sepsis, and mortality. Results: Rates of NEC fell from 7.5% (35/469 neonates) in the pre-implementation epoch to 3.1% (16/513 neonates) in the routine probiotics epoch (adjusted sub-hazard ratio=0.44, 95% CI 0.23 to 0.85, p=0.014). The more than halving of NEC rates after probiotics introduction was independent of any measured covariates, including breast milk feeding rates. Cases of late-onset sepsis fell from 106/469 (22.6%) to 59/513 (11.5%) (p<0.0001), and there was no episode of sepsis due to Lactobacillus or Bifidobacterium. All-cause mortality also fell in the routine probiotics epoch, from 67/469 (14.3%) to 47/513 (9.2%), although this was not statistically significant after multivariable adjustment (adjusted sub-hazard ratio=0.74, 95% CI 0.49 to 1.12, p=0.155). Conclusions: Administration of multispecies Lactobacillus and Bifidobacterium probiotics has been associated with a significantly decreased risk of NEC and late-onset sepsis in our neonatal unit, and no safety issues. Our data are consistent with routine use of Lactobacillus and Bifidobacterium combination probiotics having a beneficial effect on NEC prevention in very preterm neonates

    1549TiP DeLLphi-303: Phase Ib first-line combination study of tarlatamab, a DLL3-targeting half-life extended bispecific T-cell engager (HLE BiTE®), with carboplatin, etoposide, and PD-L1 inhibition in extensive stage small cell lung cancer (ES-SCLC)

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    Background: The inhibitory Notch ligand, delta-like ligand 3 (DLL3), is a compelling therapeutic target due to its aberrant expression on the cell surface in most small cell lung cancer (SCLC). Tarlatamab (AMG 757) is a half-life extended bispecific T-cell engager (HLE BiTE®) molecule designed to specifically bind DLL3 on target cancer cells and CD3 on T cells, resulting in T cell-dependent killing of tumor cells. Data from an ongoing first-in-human monotherapy study show acceptable safety with evidence of tarlatamab efficacy in patients with relapsed/refractory SCLC (NCT03319940). Adding programmed death ligand 1 (PD-L1) inhibitors to first-line platinum chemotherapy is the emerging standard-of-care (SOC) in ES-SCLC and preclinical data suggests increased antitumor activity of BiTE molecules when combined with PD-1/PD-L1 inhibition or chemotherapy.1 These data support a clinical trial of tarlatamab combined with frontline carboplatin, etoposide, and PD-L1 inhibition in ES-SCLC. Trial design: This is a phase 1b, multicenter, open-label study evaluating tarlatamab in combination with first-line SOC chemo-immunotherapy in subjects with ES-SCLC. Tarlatamab will be evaluated in two separate settings: A) In combination with carboplatin, etoposide, and a PD-L1 inhibitor followed by maintenance cycles of tarlatamab plus PD-L1 inhibitor, and B) In combination with PD-L1 inhibitor following SOC chemo-immunotherapy as a maintenance only approach. Key eligibility criteria include patients with histologically or cytologically confirmed ES-SCLC with no prior systemic treatment (except as specified in protocol) and ECOG performance status ≤1. The primary objective is to evaluate the safety, tolerability, and determine the recommended phase 2 dose and/or maximum tolerated dose of tarlatamab in combination with PD-L1 inhibition with or without chemotherapy. Secondary endpoints are objective response rate, duration of response, disease control, progression-free survival, overall survival, and pharmacokinetics

    Regulatory roles of small non-coding RNAs in sugar beet resistance against beet curly top virus

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    Beet curly top virus (BCTV) mediated yield loss in sugar beets is a major problem worldwide. The circular single-stranded DNA virus is transmitted by the beet leafhopper. Genetic sources of BCTV resistance in sugar beet are limited and commercial cultivars rely on chemical treatments versus durable genetic resistance. Phenotypic selection and double haploid production have resulted in sugar beet germplasm (KDH13-13 and KDH4-9-4) that are highly resistant to BCTV. The molecular mechanism of resistance to the virus is unknown, especially the role of small noncoding RNAs (sncRNAs) during early plant-viral interaction. Using the resistant lines along with a susceptible line (KDH19-17; 19), we demonstrate the role of sugar beet miRNAs in BCTV resistance during early infection stages when symptoms are not yet visible. The differentially expressed miRNAs altered the expression of their corresponding target genes such as pyruvate dehydrogenase (EL10Ac1g02046), carboxylesterase (EL10Ac1g01087), serine/threonine protein phosphatase (EL10Ac1g01374), and LRR receptor-like (EL10Ac7g17778), that were highly expressed in the resistant lines versus susceptible lines. Pathway enrichment analysis of the miRNA target genes showed an enrichment of genes involved in glycolysis/gluconeogenesis, galactose metabolism, starch, and sucrose metabolism to name a few. Carbohydrate analysis revealed altered glucose, galactose, fructose, and sucrose concentration in the infected leaves of resistant versus susceptible lines. We also demonstrate differential regulation of BCTV derived sncRNAs in the resistant versus susceptible lines that target sugar beet genes such as LRR (EL10Ac1g01206), 7-deoxyloganetic acid glucosyltransferase (EL10Ac5g12605), and transmembrane emp24 domain containing (EL10Ac6g14074) and altered their expression. In response to viral infection, we found that plant derived miRNAs targeted BCTV capsid protein/replication related genes and showed differences in expression among resistant and susceptible lines. The data presented here demonstrate the contribution of miRNA mediated regulation of metabolic pathways and cross-kingdom RNAi in sugar beet BCTV resistance

    The Tongue Enables Computer and Wheelchair Control for People with Spinal Cord Injury

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    The Tongue Drive System (TDS) is a wireless and wearable assistive technology, designed to allow individuals with severe motor impairments such as tetraplegia to access their environment using voluntary tongue motion. Previous TDS trials used a magnetic tracer temporarily attached to the top surface of the tongue with tissue adhesive. We investigated TDS efficacy for controlling a computer and driving a powered wheelchair in two groups of able-bodied subjects and a group of volunteers with spinal cord injury (SCI) at C6 or above. All participants received a magnetic tongue barbell and used the TDS for five to six consecutive sessions. The performance of the group was compared for TDS versus keypad and TDS versus a sip-and-puff device (SnP) using accepted measures of speed and accuracy. All performance measures improved over the course of the trial. The gap between keypad and TDS performance narrowed for able-bodied subjects. Despite participants with SCI already having familiarity with the SnP, their performance measures were up to three times better with the TDS than with the SnP and continued to improve. TDS flexibility and the inherent characteristics of the human tongue enabled individuals with high-level motor impairments to access computers and drive wheelchairs at speeds that were faster than traditional assistive technologies but with comparable accuracy
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