Simultaneous multiplex mutation of large gene families using Cas9 has the potential to revolutionize agriculture and plant sciences. The targeting of multiple genomic sites at once raises concerns ...about the efficiency and specificity in targeting. The model Arabidopsis thaliana is widely used in basic plant research. Previous work has suggested that the Cas9 off-target rate in Arabidopsis is undetectable. Here we use deep sequencing on pooled plants simultaneously targeting 14 distinct genomic loci to demonstrate that multiplex targeting in Arabidopsis is highly specific to on-target sites with no detectable off-target events. In addition, chromosomal translocations are extremely rare. The high specificity of Cas9 in Arabidopsis makes this a reliable method for clean mutant generation with no need to enhance specificity or adopt alternate Cas9 variants.
Plants have an innate immune system to fight off potential invaders that is based on the perception of nonself or modified-self molecules. Microbe-associated molecular patterns (MAMPs) are ...evolutionarily conserved microbial molecules whose extracellular detection by specific cell surface receptors initiates an array of biochemical responses collectively known as MAMP-triggered immunity (MTI). Well-characterized MAMPs include chitin, peptidoglycan, and flg22, a 22-amino acid epitope found in the major building block of the bacterial flagellum, FliC. The importance of MAMP detection by the plant immune system is underscored by the large diversity of strategies used by pathogens to interfere with MTI and that failure to do so is often associated with loss of virulence. Yet, whether or how MTI functions beyond pathogenic interactions is not well understood. Here we demonstrate that a community of root commensal bacteria modulates a specific and evolutionarily conserved sector of the
immune system. We identify a set of robust, taxonomically diverse MTI suppressor strains that are efficient root colonizers and, notably, can enhance the colonization capacity of other tested commensal bacteria. We highlight the importance of extracellular strategies for MTI suppression by showing that the type 2, not the type 3, secretion system is required for the immunomodulatory activity of one robust MTI suppressor. Our findings reveal that root colonization by commensals is controlled by MTI, which, in turn, can be selectively modulated by specific members of a representative bacterial root microbiota.
Abstract Water-soluble chitosan derivatives, chitosan- graft -glycolic acid (GA) and phloretic acid (PA) (CH-GA/PA), were designed to obtain biodegradable injectable chitosan hydrogels through ...enzymatic crosslinking with horseradish peroxidase (HRP) and H2 O2 . CH-GA/PA polymers were synthesized by first conjugating glycolic acid (GA) to native chitosan to render the polymer soluble at pH 7.4, and subsequent modification with phloretic acid (PA). The CH-GA43/PA10 with a degree of substitution (DS, defined as the number of substituted NH2 groups per 100 glucopyranose rings of chitosan) of GA of 43 and DS of PA of 10 showed a good solubility at pH values up to 10. Short gelation times (e.g. 10 s at a polymer concentration of 3 wt%), as recorded by the vial tilting method, were observed for the CH-GA43/PA10 hydrogels using HRP and H2 O2 . It was shown that these hydrogels can be readily degraded by lysozyme. In vitro culturing of chondrocytes in CH-GA43/PA10 hydrogels revealed that after 2 weeks the cells were viable and retained their round shape. These features indicate that CH-GA/PA hydrogels are promising as an artificial extracellular matrix for cartilage tissue engineering.
Abstract Polysaccharide hybrids consisting of hyaluronic acid (HA) grafted with a dextran–tyramine conjugate (Dex–TA) were synthesized and investigated as injectable biomimetic hydrogels for ...cartilage tissue engineering. The design of these hybrids (denoted as HA- g -Dex–TA) is based on the molecular structure of proteoglycans present in the extracellular matrix of native cartilage. Hydrogels of HA- g -Dex–TA were rapidly formed within 2 min via enzymatic crosslinking of the tyramine residues in the presence of horseradish peroxidase and hydrogen peroxide. The gelation time, equilibrium swelling and storage modulus could be adjusted by varying the degree of substitution of tyramine residues and polymer concentration. Bovine chondrocytes incorporated in the HA- g -Dex–TA hydrogels remained viable, as shown by the Live–dead assay. Moreover, enhanced chondrocyte proliferation and matrix production were observed in the HA- g -Dex–TA hydrogels compared to Dex–TA hydrogels. These results suggest that HA- g -Dex–TA hydrogels have a high potential as injectable scaffolds for cartilage tissue engineering.
Summary
The purpose of this systematic review and meta‐analysis was to estimate the prevalence of personal weight control attempts (weight loss and/or maintenance) worldwide and to identify ...correlates, personal strategies used and the underlying motives. We included epidemiological/observational studies of adults (≥18 years) reporting prevalence of weight control attempts in the past‐year. Seventy‐two studies (n = 1,184,942) met eligibility criteria. Results from high quality studies showed that 42% of adults from general populations and 44% of adults from ethnic‐minority populations reported trying to lose weight, and 23% of adults from general populations reported trying to maintain weight annually. In general population studies, higher prevalence of weight loss attempts was observed in the decade of 2000–2009 (48.2%), in Europe/Central Asia (61.3%) and in overweight/obese individuals and in women (p < 0.01). Of the 37 strategies (grouped in 10 domains of the Oxford Food and Activity Behaviours Taxonomy) and 12 motives reported for trying to control weight, exercising and dieting (within the energy compensation and restraint domains, respectively) and wellbeing and long‐term health were the most prevalent. To our knowledge, this is the first systematic review to investigate weight control attempts worldwide. Key strategies and motives were identified which have implications for future public health initiatives on weight control.
Cowden's syndrome is an autosomal dominant disease with variable penetrance, involving the tumor suppressor phosphatase and tension homolog gene, located on chromosome 10q22-23, responsible for cell ...proliferation, migration, and cellular apoptosis. Its clinical presentation encompasses mucocutaneous lesions, which are present around 99% of the time; macrocephaly; and cognitive impairment, and it precedes the appearance of neoplasms such as thyroid carcinoma, breast cancer, among others. In addition to these malformations, arteriovenous malformations of the brain and spine, endocrine abnormalities, skeletal defects, and cardiopulmonary lesions may also be found. The relevance of the case is due to the fact that, through a certain phenotype, the patient's genotype can be inferred and thus followed up closely.
The clinical case concerns a 28-year-old Caucasian and Portuguese woman with palmar pits, macrocephaly, and cognitive impairment. She was diagnosed with papillary thyroid carcinoma at 22 years of age and proposed total thyroidectomy. At age 27, a pregnancy was diagnosed with a Breast Imaging-Reporting and Data System 2-rated breast lump. After the histological verification, it was concluded that it was a high metastatic breast sarcoma, opting for palliative mastectomy. A genetic evaluation confirmed alteration in the phosphatase and tension homolog gene, confirming Cowden's syndrome. The patient died at age 29 due to neoplastic pathology.
This report aims to alert to the clinical signs of this entity and the clinical supervision and follow-up of these patients. In order to prevent premature deaths and to improve patient's quality of life, genetic diseases with cancer impact should be diagnosed as early as possible.
Injectable hydrogels based on hyaluronic acid (HA) and poly(ethylene glycol) (PEG) were designed as biodegradable matrices for cartilage tissue engineering. Solutions of HA conjugates containing ...thiol functional groups (HA-SH) and PEG vinylsulfone (PEG-VS) macromers were cross-linked via Michael addition to form a three-dimensional network under physiological conditions. Gelation times varied from 14
min to less than 1
min, depending on the molecular weights of HA-SH and PEG-VS, degree of substitution (DS) of HA-SH and total polymer concentration. When the polymer concentration was increased from 2% to 6% (w/v) in the presence of 100
U
ml
−1 hyaluronidase the degradation time increased from 3 to 15
days. Hydrogels with a homogeneous distribution of cells were obtained when chondrocytes were mixed with the precursor solutions. Culturing cell–hydrogel constructs prepared from HA185k-SH with a DS of 28 and cross-linked with PEG5k-4VS for 3
weeks in vitro revealed that the cells were viable and that cell division took place. Gel–cell matrices degraded in approximately 3
weeks, as shown by a significant decrease in dry gel mass. At day 21 glycosaminoglycans and collagen type II were found to have accumulated in hydrogels. These results indicate that these injectable hydrogels have a high potential for cartilage tissue engineering.
The objective of this study was to evaluate whether pre-weaning heifer calves divergent for residual feed intake (RFI) or residual feed intake and body weight gain (RIG) exhibit differences in ...thermography, blood, and ruminal parameters. Thirty-two Gyr heifer calves were enrolled in a 63-d trial and classified into 2 feed efficiency (FE) groups based on RFI and RIG (mean #177; 0.5 SD). The groups were classified as high efficiency (HE) RFI (HE RFI, n = 9), HE RIG (HE RIG, n = 10), low efficiency (LE) RFI (LE RFI, n = 10), and LE RIG (LE RIG, n = 11). The amount of whole milk provided for each calf was calculated based on their metabolic weight at birth (42% x BW.sup.0.75). The liquid diet was divided into two meals at 0700 and 1400 h. The total solid diet (TSD) was composed of 92% concentrate and 8% of Tifton 85 hay chopped in 5-cm lengths, as fed. Intake was measured daily. Blood concentrations of insulin, beta hydroxybutyrate, urea, and glucose, and ruminal pH, N-NH.sub.3, and volatile fatty acids (VFA) were evaluated at 14, 28, 42, 56, and 70 days of age. Thermal images of the calves were taken with an infrared camera (FLIR T420, FLIR Systems Inc., Wilsonville, OR) on d 56 (#177;3) at 0600 h, before the morning feeding. Total VFA concentration and propionate as % of total VFA were 24.2% and 22.2% lower in HE RFI compared to LE RFI calves, respectively. On the other hand, acetate as % of total VFA was 10.6% greater in HE RFI than LE RFI calves. Blood urea concentration tended to be greater in LE RFI than HE RFI calves. High efficiency HE RIG tended to have 6.8% greater acetate and 15.4% lower propionate as % of total VFA than LE RIG. Blood insulin concentration was greater and blood glucose tended to be greater for LE RIG than HE RIG group. Low efficiency RIG group had greater left rib, left flank, and anus surface temperature measured by infrared thermography than the HE RIG group. Differences in ruminal fermentation do not seem to be associated with pre-weaning calves efficiency, while differences in protein metabolism seem to affect RFI during this phase. Infrared thermography appears to be correlated to RIG in pre-weaning heifer calves.
Summary This study aims to evaluate the effect of 18-week progressive muscular strength and proprioception training program on the muscle strength of the quadriceps, in prevention of falls in ...postmenopausal women with osteoporosis. The incidence of falls in the intervention group was significantly lower than in the control group (incidence rate ratio (IRR) = 0.263, 95% CI 0.10-0.68). Introduction This study aims to evaluate the effect of a progressive muscular strength and proprioception training program on the muscle strength of the quadriceps, balance, quality of life, and reduction in the risk of falls in postmenopausal women with osteoporosis. Methods One hundred sedentary postmenopausal women with osteoporosis, ages ranging from 55 to 75, were selected and randomized into two groups: the intervention group comprised of 50 patients who underwent a 18-week of progressive load training for the quadriceps muscle (50% up to 80% of 1-RM—one maximum repetition) and proprioception training associated to a drug treatment of osteoporosis and the control group that included 50 patients who only underwent a drug treatment of osteoporosis. The muscular strength, balance, functional mobility, and quality of life were evaluated in the beginning and end of the research. The number of falls was evaluated 24 weeks post-treatment. Results Eighty-five patients concluded the research. The program promoted a significant difference among the groups for SF-36 in the eight sub-scales (p ≤ 0.0018), Timed Up & Go Test (p < 0.0001), 1-RM test (p < 0.0001), Berg Balance Scale (p < 0.0001) and also a decrease in the number of falls in the intervention group compared to control (IRR = 0.263, 95% CI 0.10-0.68, p = 0.0064). Conclusion The association of progressive strength training for the quadriceps and the proprioceptive training is effective for the prevention of falls, increasing the muscle power, the static and dynamic balance and increasing the speed of the motor responses, therefore improving the performance of daily activities.
Abstract Biomarkers are important factors in the identification of the frail elderly (higher risk of developing disease) and in assessing the impact of PTI. On the other hand, BDNF has been related ...to neuroprotection in a series of central nervous system diseases in older age. The levels of BDNF in groups of elderly women classified according to Fried phenotype (non-frail and pre-frail) were compared. We assessed the impact of a PTI on BDNF levels. A convenience sample of 48 elderly women was randomly selected. The PTI group was composed by 20 elderly women selected from this group. Plasma neurotrophic factors, such as BDNF, glial-derived neutrophic factor (GDNF), and nerve growth factor (NGF) were measured by enzyme-linked immunosorbent assay (ELISA). Timed-up-and-go (TUG) test, hand-grip and work/body weight were evaluated before and after the intervention. Plasma concentrations of BDNF were significantly higher in non-frail in comparison to pre-frail elderly women. After the PTI, higher levels of BDNF were found in elderly women (before 351 ± 68 pg/ml and after 593 ± 79 pg/ml; p < 0.001). Both groups had an increase in BDNF levels after the PTI. The low levels of BDNF in pre-frail elderly women suggest that this neurotrophic factor may be a key pathophysiological mediator in the syndrome of frailty. The fact that PTI increased BDNF levels in both groups suggests that it may be possible to modify this phenotype.
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