Mechanistic insights into strigolactone biosynthesis, signaling and regulation during plant growth and development

Strigolactones (SLs) constitute a group of carotenoid-derived phytohormones with butenolide moieties. These hormones are involved in various functions, including regulation of secondary growth, shoot branching and hypocotyl elongation, and stimulation of seed germination. SLs also control hyphal branching of arbuscular mycorrhizal (AM) fungi, and mediate responses to both abiotic and biotic cues. Most of these functions stem from the interplay of SLs with other hormones, enabling plants to appropriately respond to changing environmental conditions. This dynamic interplay provides opportunities for phytohormones to modulate and augment one another. In this article, we review our current mechanistic understanding of SL biosynthesis, receptors and signaling. We also highlight recent advances regarding the interaction of SLs with other hormones during developmental processes and stress conditions

Factors that influence a patient’s decision to engage in genetic research

IntroductionThe most challenging step in clinical research studies is patient recruitment. Many research studies do not reach their targets because of participant rejection. The purpose of this study was to assess patient as well as the community knowledge, motivation, and barriers to participate in genetic research.MethodsA cross-section study was conducted between September 2018 and February 2020 using face-to-face interviews with candidate patients from outpatient clinics at King Fahad Medical City (KFMC), Riyadh, Saudi Arabia. Additionally, an online survey was conducted to assess the community’s knowledge, motivation and barriers to participate in genetic research studies.ResultsIn total, 470 patients were interviewed for this study, with 341 being successfully recruited for the face to face interview, and the other patients being refused owing to time constraints. The majority percentage of the respondents were females. The respondents’ mean age was 30, and 52.6% reported having a college degree. The survey results from 388 participants illustrated that around 90% of the participants, participated voluntarily due to a good understanding of genetics studies. The majority held positive attitudes toward being part of genetic research, which exceeded the reported motivation score of >75%. The survey indicated that >90% of individuals were willing to participate to acquire therapeutic benefits or to receive continued aftercare. However, 54.6% of survey participants were worried about the side effects and the risks involved in genetic testing. A higher proportion (71.4%) of respondents reported that lack of knowledge about genetic research was one of the barriers to rejecting participation.ConclusionRespondents reported relatively high motivation and knowledge for participation in genetic research. However, study participants reported “do not know enough about genetic research” and “lack of time during clinic visit” as a barrier for participation in genetic research

TSG-6 Regulates Bone Remodeling through Inhibition of Osteoblastogenesis and Osteoclast Activation

TSG-6 is an inflammation-induced protein that is produced at pathological sites, including arthritic joints. In animal models of arthritis, TSG-6 protects against joint damage; this has been attributed to its inhibitory effects on neutrophil migration and plasmin activity. Here we investigated whether TSG-6 can directly influence bone erosion. Our data reveal that TSG-6 inhibits RANKL-induced osteoclast differentiation/activation from human and murine precursor cells, where elevated dentine erosion by osteoclasts derived from TSG-6-/- mice is consistent with the very severe arthritis seen in these animals. However, the long bones from unchallenged TSG-6-/- mice were found to have higher trabecular mass than controls, suggesting that in the absence of inflammation TSG-6 has a role in bone homeostasis; we have detected expression of the TSG-6 protein in the bone marrow of unchallenged wild type mice. Furthermore, we have observed that TSG-6 can inhibit bone morphogenetic protein-2 (BMP-2)-mediated osteoblast differentiation. Interaction analysis revealed that TSG-6 binds directly to RANKL and to BMP-2 (as well as other osteogenic BMPs but not BMP-3) via composite surfaces involving its Link and CUB modules. Consistent with this, the full-length protein is required for maximal inhibition of osteoblast differentiation and osteoclast activation, although the isolated Link module retains significant activity in the latter case. We hypothesize that TSG-6 has dual roles in bone remodeling; one protective, where it inhibits RANKL-induced bone erosion in inflammatory diseases such as arthritis, and the other homeostatic, where its interactions with BMP-2 and RANKL help to balance mineralization by osteoblasts and bone resorption by osteoclasts

Molecular Mechanisms of Nitric Oxide (NO) Signaling and Reactive Oxygen Species (ROS) Homeostasis during Abiotic Stresses in Plants

Abiotic stressors, such as drought, heavy metals, and high salinity, are causing huge crop losses worldwide. These abiotic stressors are expected to become more extreme, less predictable, and more widespread in the near future. With the rapidly growing human population and changing global climate conditions, it is critical to prevent global crop losses to meet the increasing demand for food and other crop products. The reactive gaseous signaling molecule nitric oxide (NO) is involved in numerous plant developmental processes as well as plant responses to various abiotic stresses through its interactions with various molecules. Together, these interactions lead to the homeostasis of reactive oxygen species (ROS), proline and glutathione biosynthesis, post-translational modifications such as S-nitrosylation, and modulation of gene and protein expression. Exogenous application of various NO donors positively mitigates the negative effects of various abiotic stressors. In view of the multidimensional role of this signaling molecule, research over the past decade has investigated its potential in alleviating the deleterious effects of various abiotic stressors, particularly in ROS homeostasis. In this review, we highlight the recent molecular and physiological advances that provide insights into the functional role of NO in mediating various abiotic stress responses in plants

Is the World Health Organization-recommended dose of pralidoxime effective in the treatment of organophosphorus poisoning? A randomized, double-blinded and placebo-controlled trial

Background: Organophosphorus poisoning (OPP) is a major global public health problem. Pralidoxime has been used in a complimentary role to atropine for the management of OPP. World Health Organization (WHO) recommends use of pralidoxime but studies regarding its role have been inconclusive, ranging from being ineffective to harmful or beneficial. Materials and Methods: The present study was undertaken to evaluate the effectiveness of pralidoxime. Eddleston′s study was the most compelling factor for our study, as he showed worst outcomes using pralidoxime. Our practice of continuous use of pralidoxime was based on the WHO guidelines and the study by Pawar (2006), which showed better outcome with higher doses of pralidoxime. These conflicting results suggested that a re-evaluation of its use in our clinical practice was indicated. Results: There was no difference in mortality rates, hemodynamic parameters and atropine requirements between the AP and A groups. Mean duration of ventilation (3.6 ± 4.6 in AP group vs. 3.6 ± 4.4 in A group) and Intensive Care Unit stay (7.1 ± 5.4 in AP group vs. 6.8 ± 4.7 in A group) was comparable. Serum sodium concentrations showed a correlation with mortality, with lower concentrations associated with better outcomes. Conclusion: The study suggests that add-on WHO-recommended pralidoxime therapy does not provide any benefit over atropine monotherapy. Adding pralidoxime does not seem to be beneficial and at the same time does not result in increased mortality rates. Our practice changed after completion of this study, and it has proven to be of significant benefit to patients who had to bear the expense of treatment

The Accuracy of Broselow Tape Weight Estimate among Pediatric Population

Objective. To determine the accuracy of the Broselow Tape (BT) versions 2007 and 2011 in estimating weight among pediatric population. Methods. A cross-sectional study was conducted at King Fahad Medical City and six schools across Riyadh province on 1–143-month-old children. BT 2007 and 2011 estimated weights were recorded. Both tapes via the child’s height produce an estimated weight, which was compared with the actual weight. Results. A total of 3537 children were recruited. The height (cm) of the subjects was 97.7±24.1 and the actual weight (kg) was 16.07±8.9, whereas the estimated weight determined by BT 2007 was 15.87±7.56 and by BT 2011 was 16.38±7.95. Across all the five age groups, correlation between actual weight and BT 2007 ranged between 0.702 and 0.788, while correlation between actual weight and BT 2011 ranged between 0.698 and 0.788. Correlation between BT 2007 and BT 2011 across all the five age groups ranged from 0.979 to 0.989. Accuracy of both the tape versions was adversely affected when age was >95 months and body weight was >26 kilograms. Conclusions. Our study showed that BT 2007 and 2011 provided accurate estimation of the body weight based on measured body height. However, 2011 version provided more precise estimate for weight

Cricoid ring: Shape, size, and variability in infants and children

Background: Knowledge regarding the shape, size, and variability of the cricoid ring is important to properly choose the correct endotracheal tube (ETT) in the pediatric patient. Studies have measured the size of the cricoid ring using methodologies such as moulages, magnetic resonance imaging, and video-bronchoscopy. In the present study, computed tomography (CT) -based images were used to determine the shape, size, and configuration of the cricoid ring in the pediatric population taking into considerations growth and development. Methods: This is a retrospective review using 130 CT images of children ranging in age from 1 month to 10 years undergoing radiological evaluation unrelated to airway symptomatology. The CT scans were obtained in spontaneously breathing patients during either natural sleep or procedural sedation. Anteroposterior (AP) and transverse (T) diameters were measured at the cricoid ring using these images. Results: The cricoid ring is generally round in children older than 1 year with a T/AP ratio ranging between 0.98 and 1.01. However, in infants (1–12 months of age), the cricoid ring is elliptical with the AP dimension an average of 0.31 mm larger than the T dimension with a T/AP ratio of 0.95. A statistically significant difference between the T and AP dimensions was only observed in infancy (P < 0.05). Conclusion: The cricoid ring is round in children older than 1 year of age. In infants, the cricoid shape presents a more elliptical configuration because the T-axis is narrower than the AP dimension. CT is recognized as the most accurate technique to study cricoid ring configuration, and the present data may help clinicians determine the appropriate type, size, and shape of ETTs, particularly in infants

Table_1_Systems biology of chromium-plant interaction: insights from omics approaches.docx

Plants are frequently subjected to heavy metal (HM) stress that impedes their growth and productivity. One of the most common harmful trace metals and HM discovered is chromium (Cr). Its contamination continues to increase in the environment due to industrial or anthropogenic activities. Chromium is severely toxic to plant growth and development and acts as a human carcinogen that enters the body by inhaling or taking Cr-contaminated food items. Plants uptake Cr via various transporters, such as sulfate and phosphate transporters. In nature, Cr is found in various valence states, commonly Cr (III) and Cr (VI). Cr (VI) is soil’s most hazardous and pervasive form. Cr elevates reactive oxygen species (ROS) activity, impeding various physiological and metabolic pathways. Plants have evolved various complex defense mechanisms to prevent or tolerate the toxic effects of Cr. These defense mechanisms include absorbing and accumulating Cr in cell organelles such as vacuoles, immobilizing them by forming complexes with organic chelates, and extracting them by using a variety of transporters and ion channels regulated by various signaling cascades and transcription factors. Several defense-related proteins including, metallothioneins, phytochelatins, and glutathione-S-transferases aid in the sequestration of Cr. Moreover, several genes and transcriptional factors, such as WRKY and AP2/ERF TF genes, play a crucial role in defense against Cr stress. To counter HM-mediated stress stimuli, OMICS approaches, including genomics, proteomics, transcriptomics, and metallomics, have facilitated our understanding to improve Cr stress tolerance in plants. This review discusses the Cr uptake, translocation, and accumulation in plants. Furthermore, it provides a model to unravel the complexities of the Cr-plant interaction utilizing system biology and integrated OMICS approach.</p