254 research outputs found
Engineered food supplement excipients from bitter cassava for minimisation of cassava processing waste in environment
This is a research paper unchecked large-scale rudimentary upstream (submerged and solid-state fermentation processes of bitter cassava roots into alcohol have often contributed significantly to agricultural wastes in the environment.Unchecked large-scale rudimentary upstream (sub-merged and solid state) fermentation processes of bitter cas- sava roots into alcohol have often contributed significantly to agricultural wastes into environment. Thus, the study explored a proven valorisation methodology, Simultaneous Release Recovery Cyanogenesis (SRRC) along with intact bitter cassava polysaccharide-rich derivatives (CWF), as an apt to find alternative materials for food supplement excipients. Triplicate CWF powder, peeled or intact bitter cassava roots, were produced and analysed to determine crit- ical properties suitable in tablet making. Exclusion approach, using SRRC and compaction, was performed to select desired powder properties for tablet formulation. Microcrystalline cellulose, with known properties for developing drug excipients, was used as a validation reference material. Tablets, for disintegration time and in- vitro dissolution rates studies were produced using wet-granulation, and their potential to release and bio-avail Iron-Zinc investigated in-vitro (pHs 1.2 and 6.8 solutions, 37 0 C). Morphology and Iron-Zinc dissolution-release mechanisms were examined. Kinetic models were used to describe matrix dissolution and Iron-Zinc release mech- anisms. Intact root powder compaction capacity, depicted by hardness, was 4.3, 4.4 and 4.6 KG at 200, 500 and 700 MPa respectively. Scanning Electron Microscopy (SEM) showed Iron-Zinc inclusion altered tablet morphol- ogy. Efficient matrix dissolution and Iron and Zinc release were achieved, showing apex recovery efficiency (98%, 30–45 min). Fitted models well-explained dissolution and release mechanisms (mean R 2 = 0.95), demonstrating adequacy. SRRC-improved intact bitter cassava was confirmed as potential alternative excipient’s matrix for Iron and Zinc release and bioavailability. Thus, this approach is practical for indirect waste elimination, and can promote strategy for sustainable valorisation of agricultural wastes and alternative functional food supplements delivery system
Cytokinin response factors regulate PIN-FORMED auxin transporters
Auxin and cytokinin are key endogenous regulators of plant development. Although cytokinin-mediated modulation of auxin distribution is a developmentally crucial hormonal interaction, its molecular basis is largely unknown. Here we show a direct regulatory link between cytokinin signalling and the auxin transport machinery uncovering a mechanistic framework for cytokinin-auxin cross-talk. We show that the CYTOKININ RESPONSE
FACTORS (CRFs), transcription factors downstream of cytokinin perception, transcriptionally control genes encoding PIN-FORMED (PIN) auxin transporters at a specific PIN CYTOKININ RESPONSE ELEMENT (PCRE) domain. Removal of this cis-regulatory element effectively
uncouples PIN transcription from the CRF-mediated cytokinin regulation and attenuates plant
cytokinin sensitivity. We propose that CRFs represent a missing cross-talk component that fine-tunes auxin transport capacity downstream of cytokinin signalling to control plant development
Evaluation of LOXL1 gene polymorphisms in exfoliation syndrome and exfoliation glaucoma
Purpose: To evaluate genetic susceptibility of lysyl oxidase-like 1 (LOXL1) gene polymorphisms to exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) in a case-control cohort of American and European patients.
Methods: DNA from a total of 620 individuals including 287 exfoliation patients and 333 healthy control subjects were
extracted by standard methods. Three single nucleotide polymorphisms (SNPs) of rs1048661 (R141L), rs3825942
(G153D), and rs2165241 were genotyped in these individuals by SNaPshot Assay. The seven coding exons of the LOXL1 gene and their immediate flanking regions were directly sequenced in 95 affected patients. Data management and
case-control association studies were performed with SNP-STAT and PLINK programs. The obtained DNA sequences
were evaluated with the STADEN package.
Results: The 287 unrelated exfoliation cases comprised of 171 American patients (mostly of European background) and
116 patients from 12 European countries. This phenotype was further divided into patients with exfoliation only and no
glaucoma (XFO; n=95), exfoliation with glaucoma (XFG; n=133), and exfoliation unclassified (XFU; n=59). Genotypic
data were analyzed separately for XFO, XFG, XFU, and XFS (all exfoliations; n=287) and for Americans and Europeans.
The observed genotypic frequencies for each exfoliation phenotype or population were tabulated separately and tested for deviation from the Hardy–Weinberg equilibrium (HWE) using a standard Χ2 test. There were no HWE deviations and no significant genotypic differences between these subcategories for the three studied SNPs. For the combined exfoliation cohort, homozygote genotypes of G/G (rs1048661), G/G (rs3825942), and T/T (rs2165241) were significantly overrepresented. Likewise, case-control allelic association for rs1048661 (p=7.74x10−9), rs3825942 (p=3.10x10−17), and rs2165241 (p=4.85x10−24) were highly significant. The corresponding two-locus haplotype frequencies of GG for rs1048661-rs3825942 (p=1.47x10−27), GT for rs1048661-rs2165241 (p=1.29x10−24), and GT for rs3825942-rs2165241 (p=2.02x10−24) were highly associated with exfoliation phenotypes. The combined effect of these three SNPs revealed that the GGT haplotype is overrepresented by 66% in exfoliation cases, and this deviation from controls is highly significant
(p=1.93x10−24). This haplotype constituted a major risk factor for development of exfoliation in both XFS and XFG. By contrast, the GAC haplotype was significantly underrepresented (p=4.99x10−18) in exfoliation cases by 83% and may potentially have a protective effect for this condition with an estimated attributable risk percent reduction of 457%. The only other haplotype that was significantly different between cases and controls was TGC (p=5.82x10−9). No observation was made for the GAT haplotype. The combined three haplotypes of GGT, GAC, and TGC were associated with 91% of the exfoliation syndrome cases in the studied populations. Seven coding exons of LOXL1 were also sequenced in 95 affected cases. In addition to the three above-mentioned SNPs, 12 other variations were also observed in these patients(G240G, D292D, A320A, V385V, rs2304719, IVS3+23C>T, IVS3–155G>A, IVS3–101G>A, IVS4+49G>A,
rs2304721, IVS5–121C>T, and rs2304722). None were considered a disease-causing mutation.
Conclusions: We confirmed a strong association with LOXL1 variants in our patients. For the LOXL1 gene, individual
alleles of rs1048661 (G), rs3825942 (G), and rs2165241 (T) are highly associated with XFS and XFG in American and
European populations. The GGT haplotype constitutes a major risk haplotype for exfoliation, and GAC may have a
protective role. DNA sequencing of 95 affected patients did not show any mutations in this gene. The LOXL1 SNPs are
located in the 15q24.1 band and within a genetic locus (GLC1N) that is associated with primary open-angle glaucoma
(POAG). However, the LOXL1 genetic predisposition is only limited to exfoliation with or without glaucoma and does
not include the POAG phenotype
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Personalized Genetic Risk Counseling to Motivate Diabetes Prevention: A randomized trial
OBJECTIVE To examine whether diabetes genetic risk testing and counseling can improve diabetes prevention behaviors. RESEARCH DESIGN AND METHODS We conducted a randomized trial of diabetes genetic risk counseling among overweight patients at increased phenotypic risk for type 2 diabetes. Participants were randomly allocated to genetic testing versus no testing. Genetic risk was calculated by summing 36 single nucleotide polymorphisms associated with type 2 diabetes. Participants in the top and bottom score quartiles received individual genetic counseling before being enrolled with untested control participants in a 12-week, validated, diabetes prevention program. Middle-risk quartile participants were not studied further. We examined the effect of this genetic counseling intervention on patient self-reported attitudes, program attendance, and weight loss, separately comparing higher-risk and lower-risk result recipients with control participants. RESULTS The 108 participants enrolled in the diabetes prevention program included 42 participants at higher diabetes genetic risk, 32 at lower diabetes genetic risk, and 34 untested control subjects. Mean age was 57.9 ± 10.6 years, 61% were men, and average BMI was 34.8 kg/m2, with no differences among randomization groups. Participants attended 6.8 ± 4.3 group sessions and lost 8.5 ± 10.1 pounds, with 33 of 108 (30.6%) losing ≥5% body weight. There were few statistically significant differences in self-reported motivation, program attendance, or mean weight loss when higher-risk recipients and lower-risk recipients were compared with control subjects (P > 0.05 for all but one comparison). CONCLUSIONS Diabetes genetic risk counseling with currently available variants does not significantly alter self-reported motivation or prevention program adherence for overweight individuals at risk for diabetes
Modulation of plant root growth by nitrogen source-defined regulation of polar auxin transport
Availability of the essential macronutrient nitrogen in soil plays a critical role in plant growth, development, and impacts agricultural productivity. Plants have evolved different strategies for sensing and responding to heterogeneous nitrogen distribution. Modulation of root system architecture, including primary root growth and branching, is among the most essential plant adaptions to ensure adequate nitrogen acquisition. However, the immediate molecular pathways coordinating the adjustment of root growth in response to distinct nitrogen sources, such as nitrate or ammonium, are poorly understood. Here, we show that growth as manifested by cell division and elongation is synchronized by coordinated auxin flux between two adjacent outer tissue layers of the root. This coordination is achieved by nitrate‐dependent dephosphorylation of the PIN2 auxin efflux carrier at a previously uncharacterized phosphorylation site, leading to subsequent PIN2 lateralization and thereby regulating auxin flow between adjacent tissues. A dynamic computer model based on our experimental data successfully recapitulates experimental observations. Our study provides mechanistic insights broadening our understanding of root growth mechanisms in dynamic environments
Scintillation-limited photometry with the 20-cm NGTS telescopes at Paranal Observatory
Ground-based photometry of bright stars is expected to be limited by atmospheric scintillation, although in practice observations are often limited by other sources of systematic noise. We analyse 122 nights of bright star (Gmag ≲ 11.5) photometry using the 20-cm telescopes of the Next-Generation Transit Survey (NGTS) at the Paranal Observatory in Chile. We compare the noise properties to theoretical noise models and we demonstrate that NGTS photometry of bright stars is indeed limited by atmospheric scintillation. We determine a median scintillation coefficient at the Paranal Observatory of CY=1.54, which is in good agreement with previous results derived from turbulence profiling measurements at the observatory. We find that separate NGTS telescopes make consistent measurements of scintillation when simultaneously monitoring the same field. Using contemporaneous meteorological data, we find that higher wind speeds at the tropopause correlate with a decrease in long-exposure (t = 10 s) scintillation. Hence, the winter months between June and August provide the best conditions for high-precision photometry of bright stars at the Paranal Observatory. This work demonstrates that NGTS photometric data, collected for searching for exoplanets, contains within it a record of the scintillation conditions at Paranal
Cooperativity and flexibility in enzyme evolution
Enzymes are flexible catalysts, and there has been substantial
discussion about the extent to which this flexibility contributes
to their catalytic efficiency. What has been significantly less
discussed is the extent to which this flexibility contributes to
their evolvability. Despite this, recent years have seen an
increasing number of both experimental and computational
studies that demonstrate that cooperativity and flexibility play
significant roles in enzyme innovation. This review covers key
developments in the field that emphasize the importance of
enzyme dynamics not just to the evolution of new enzyme
function(s), but also as a property that can be harnessed in the
design of new artificial enzymes.The European Research Council has provided financial support under the
European Community’s Seventh Framework Program (FP7/2007-2013)/ERC
Grant Agreement No. 306474. This work was also funded by the Feder
Funds, Grants from the Spanish Ministry of Economy and Competitiveness
(BIO2015-66426-R and CSD2009-00088) and the Human Frontier Science
Program (RGP0041/2017). A.P. is a Wenner-Gren Foundations Postdoctoral
Fellow and S. C. L. K. is a Wallenberg Academy Fellow
Cutaneous Head and Neck Squamous Cell Carcinoma with Regional Metastases: The Prognostic Importance of Soft Tissue Metastases and Extranodal Spread
Extranodal spread (ENS) is an established adverse prognostic factor in metastatic cutaneous squamous cell carcinoma (cSCC); however, the clinical significance of soft tissue metastases (STM) is unknown. The aim of this study was to evaluate the prognosis of patients with STM from head and neck cSCC, and to compare this with that of node metastases with and without ENS. Patients with cSCC metastatic to the parotid and/or neck treated by primary surgical resection between 1987 and 2007 were included. Metastatic nodes > 3 cm in size were an exclusion criterion. A Cox proportional hazard model was used to determine the effect of STM adjusting for other relevant prognostic factors. The population included 164 patients with a median follow-up of 26 months. There were 8 distant and 37 regional recurrences. There were 22 were cancer-specific deaths, and 29 patients died. STM was a significant predictor of reduced overall (hazard ratio 3.3; 95% confidence interval 1.6-6.4; P = 0.001) and disease-free survival (hazard ratio 2.4; 95% confidence interval 1.4-4.1; P = 0.001) when compared to patients with node disease with or without ENS. After adjusting for covariates, STM and number of involved nodes were significant independent predictors of overall and disease-free survival. In metastatic cSCC of the head and neck, the presence of STM is an independent predictor of reduced survival and is associated with a greater adverse effect than ENS alone
Assay for high glucose-mediated islet cell sensitization to apoptosis induced by streptozotocin and cytokines
Pancreatic β-cell apoptosis is known to participate in the β-cell destruction process that occurs in diabetes. It has been described that high glucose level induces a hyperfunctional status which could provoke apoptosis. This phenomenon is known as glucotoxicity and has been proposed that it can play a role in type 1 diabetes mellitus pathogenesis. In this study we develop an experimental design to sensitize pancreatic islet cells by high glucose to streptozotocin (STZ) and proinflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor (TNF)-α and interferon (IFN)-γ]-induced apoptosis. This method is appropriate for subsequent quantification of apoptotic islet cells stained with Tdt-mediated dUTP Nick-End Labeling (TUNEL) and protein expression assays by Western Blotting (WB)
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