214 research outputs found
Presence of 5-hydroxyguaiacyl units as native lignin constituents in plants as seen by Py-GC/MS
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080-Seville, Spain
2Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
E-mail address: [email protected] (J.C. del Río)The presence of 5-hydroxyguaiacyl moieties in the lignin from several plants has been assessed by Py-GC/MS. Different woody (eucalypt) and nonwoody (flax, hemp, kenaf, jute, sisal and abaca) angiosperms were selected for this study. The pyrolysis of whole fibers released lignin-derived products with p-hydroxyphenyl, guaiacyl and syringyl structures. Indeed, a series of compounds having a 5-hydroxyguaiacyl nuclei, including 3-methoxycatechol, 5-vinyl-3-methoxycatechol and 5-propenyl-3-methoxycatechol, were detected and identified in all samples, although in lower amounts than the normal guaiacyl and syringyl compounds. The analysis of the lignins isolated from the same plants also indicated the presence of 5-hydroxyguaiacyl moieties in the isolated lignins. These compounds are supposed to arise from the pyrolysis of 5-hydroxyguaiacyl moieties, which are supposed to be native constituents of lignin in plants forming benzodioxane substructures.This study has been supported by the Spanish Ministerio de Ciencia y Tecnología (MCyT) and FEDER funds (project AGL2005-01748) and the EU project BIORENEW (NMP2-CT-2006-026456). We thank CELESA S.A. (Tortosa, Spain) for providing the nonwoody plant samples, and ENCE for providing the eucalypt wood sample.Peer reviewe
Exenatide Improves Bone Quality in a Murine Model of Genetically Inherited Type 2 Diabetes Mellitus
Type 2 diabetes mellitus (T2DM) is associated with skeletal complications, including an
increased risk of fractures. Reduced blood supply and bone strength may contribute to
this skeletal fragility. We hypothesized that long-term administration of Exenatide, a glucagon-
like peptide-1 receptor agonist, would improve bone architecture and strength of
T2DM mice by increasing blood flow to bone, thereby stimulating bone formation. In this study, we used a model of obesity and severe T2DM, the leptin receptor-deficient db/db mouse to assess alterations in bone quality and hindlimb blood flow and to examine the beneficial effects of 4 weeks administration of Exenatide. As expected, diabetic mice showed marked alterations in bone structure, remodeling and strength, and basal vascular tone compared with lean mice. Exenatide treatment improved trabecular bone mass and architecture by increasing bone formation rate, but only in diabetic mice. Although there was no effect on hindlimb perfusion at the end of this treatment, exenatide administration acutely increased tibial blood flow. While Exenatide treatment did not restore the
impaired bone strength, intrinsic properties of the matrix, such as collagen maturity, were improved. The effects of Exenatide on in vitro bone formation were further investigated in primary osteoblasts cultured under high-glucose conditions, showing that Exenatide
reversed the impairment in bone formation induced by glucose. In conclusion, Exenatide improves trabecular bone mass by increasing bone formation and could protect against the development of skeletal complications associated with T2DM
Genomic copy number variation association study in Caucasian patients with nonsyndromic cryptorchidism
Copy number variation (CNV) is a potential contributing factor to many genetic diseases. Here we investigated the potential association of CNV with nonsyndromic cryptorchidism, the most common male congenital genitourinary defect, in a Caucasian population
MOSQUITO NET WITH DINOTEFURAN AND PBO FOR KILLING MOSQUITOES, ESPECIALLY MOSQUITOES WITH PYRETHROID RESISTANCE
Dinotefuran and PBO is used for killing mosquitoes, as PBO increases the knockdown speed of Dinotefuran.
The present invention relates to insecticidal mosquito nets containing PBO in combination with an insecticide.
One of the methods to counteract malaria is the use of commercially available long lasting insecticidal mosquito nets for protecting humans from the bite of Anopheline mosquitoes that carry malaria. Whereas the typically applied pyrethroids have been used successfully as insecticides on such nets due to their rapid knockdown effect, there is currently a critical increased resistance to pyrethroids observed among those mosquitoes. One type of resistance is metabolic, which is counteracted by applying piperonyl butoxide (PBO) simultaneously with a pyrethroid to the mosquito when resting on the net. The PBO works as an inhibitor of the resistance associated metabolic enzymes and increases the mortality rate of the pyrethroid resistant mosquitoes. Another type of resistance is through a mutation at the target site of the pyrethroid, known as knockdown-resistance (kdr), which significantly slows the knockdown effect when the mosquito rests on the net and gives the mosquito the possibility to bite before paralysis (followed by death)
Should the Definition of Food Deserts Incorporate a Seasonal Component?
Households may experience geographic, transportation, and other spatial barriers to
healthy eating when there is a dearth of fresh foods nearby to where they live. Communities with a low
supply of healthy foods nearby are typically referred to as food deserts, and are formally defined as
areas with at least 33 percent of the population residing more than one mile away from a supermarket
or grocery store. This definition emphasizes the spatial aspects of the food access challenge without
addressing potential seasonal aspects, and there are many potential seasonal factors which influence
food access, especially for low-resource households. During winter, it may be especially difficult to
access healthy foods because days are shorter, it gets dark earlier, sidewalks may not be clear of snow
for walking, public transit service may be more intermittent, inclement weather might make it harder to
walk places, certain fruits and vegetables are highly seasonal, delivery trucks may be delayed more
frequently, and farmers markets aren’t operating as intensively. Understanding the seasonal barriers to
healthy eating is important for informing nutrition policies and programs, especially initiatives focused
on eliminating food deserts.Howard Hughes Medical Institute /Published articl
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Oxygen Tension and the VHL-Hif1α Pathway Determine Onset of Neuronal Polarization and Cerebellar Germinal Zone Exit.
Postnatal brain circuit assembly is driven by temporally regulated intrinsic and cell-extrinsic cues that organize neurogenesis, migration, and axo-dendritic specification in post-mitotic neurons. While cell polarity is an intrinsic organizer of morphogenic events, environmental cues in the germinal zone (GZ) instructing neuron polarization and their coupling during postnatal development are unclear. We report that oxygen tension, which rises at birth, and the von Hippel-Lindau (VHL)-hypoxia-inducible factor 1α (Hif1α) pathway regulate polarization and maturation of post-mitotic cerebellar granule neurons (CGNs). At early postnatal stages with low GZ vascularization, Hif1α restrains CGN-progenitor cell-cycle exit. Unexpectedly, cell-intrinsic VHL-Hif1α pathway activation also delays the timing of CGN differentiation, germinal zone exit, and migration initiation through transcriptional repression of the partitioning-defective (Pard) complex. As vascularization proceeds, these inhibitory mechanisms are downregulated, implicating increasing oxygen tension as a critical switch for neuronal polarization and cerebellar GZ exit
Drebrin-mediated microtubule-actomyosin coupling steers cerebellar granule neuron nucleokinesis and migration pathway selection
Neuronal migration from a germinal zone to a final laminar position is essential for the morphogenesis of neuronal circuits. While it is hypothesized that microtubule-actomyosin crosstalk is required for a neuron's 'two-stroke' nucleokinesis cycle, the molecular mechanisms controlling such crosstalk are not defined. By using the drebrin microtubule-actin crosslinking protein as an entry point into the cerebellar granule neuron system in combination with super-resolution microscopy, we investigate how these cytoskeletal systems interface during migration. Lattice light-sheet and structured illumination microscopy reveal a proximal leading process nanoscale architecture wherein f-actin and drebrin intervene between microtubules and the plasma membrane. Functional perturbations of drebrin demonstrate that proximal leading process microtubule-actomyosin coupling steers the direction of centrosome and somal migration, as well as the switch from tangential to radial migration. Finally, the Siah2 E3 ubiquitin ligase antagonizes drebrin function, suggesting a model for control of the microtubule-actomyosin interfaces during neuronal differentiation.</p
Truncating mutations in the last exon of NOTCH3 cause lateral meningocele syndrome
Lateral meningocele syndrome (LMS, OMIM%130720), also known as Lehman syndrome, is a very rare skeletal disorder with facial anomalies, hypotonia and meningocele-related neurologic dysfunction. The characteristic lateral meningoceles represent the severe end of the dural ectasia spectrum and are typically most severe in the lower spine. Facial features of LMS include hypertelorism and telecanthus, high arched eyebrows, ptosis, midfacial hypoplasia, micrognathia, high and narrow palate, low-set ears and a hypotonic appearance. Hyperextensibility, hernias and scoliosis reflect a connective tissue abnormality, and aortic dilation, a high-pitched nasal voice, wormian bones and osteolysis may be present. Lateral meningocele syndrome has phenotypic overlap with Hajdu-Cheney syndrome. We performed exome resequencing in five unrelated individuals with LMS and identified heterozygous truncating NOTCH3 mutations. In an additional unrelated individual Sanger sequencing revealed a deleterious variant in the same exon 33. In total, five novel de novo NOTCH3 mutations were identified in six unrelated patients. One had a 26 bp deletion (c.6461_6486del, p.G2154fsTer78), two carried the same single base pair insertion (c.6692_93insC, p.P2231fsTer11), and three individuals had a nonsense point mutation at c.6247A > T (pK2083*), c.6663C > G (p.Y2221*) or c.6732C > A, (p.Y2244*). All mutations cluster into the last coding exon, resulting in premature termination of the protein and truncation of the negative regulatory proline-glutamate-serine-threonine rich PEST domain. Our results suggest that mutant mRNA products escape nonsense mediated decay. The truncated NOTCH3 may cause gain-of-function through decreased clearance of the active intracellular product, resembling NOTCH2 mutations in the clinically related Hajdu-Cheney syndrome and contrasting the NOTCH3 missense mutations causing CADASIL
Zinc Intake and Biochemical Markers of Bone Turnover in Type 1 Diabetes
OBJECTIVE—To examine the relationship between Zn nutritive status and biochemical markers of bone turnover in type 1 diabetes
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