25 research outputs found
In vitro propagation of two triploid hybrids of watermelon through adventitious shoot organogenesis and shoot tip culture
In vitro propagation protocol for two triploid hybrids of watermelon using cotyledon explants and shoot tips was achieved. Five benzyladenine (BA) concentrations were tested using cotyledon and shoot tip explants. Cotyledon explants and shoot tips from 6 and 15-20 days aseptically germinated were cultured on Murashige and Skoog medium (MS) containing test concentration of benzyladenine (2.22, 4.44, 10, 24.61 and 44.4 μM). Adventitious hoot organogenesis was initiated in all induction media and the differences among BA concentration were significant. MS medium containing 4.44, 10 and 24.61 μM BA showed the highest percentage of explants with shoots. The stimulation of axillary-bud development from excised shoot tips by a high cytokinin (BA) was observed. Axillary shoots were obtained from shoot tips of triploid watermelon and the multiplication rate ranged from 2 to 5.6 plants dependence on benzyladenine concentration and genotype. Obtained data showed that variation in regeneration rate was demonstrated. Shoots were excised and elongated in MS medium without hormones. The elongated shoots were rooted in MS medium containing 0.1 μM α-naphthalene acetic acid (NAA). Rooted plants were successfully acclimatized and gradually hardened-off to green-house conditions and subsequently established in soil with a survival rate of 80%
Longitudinal changes in peri-papillary retinal nerve fiber layer thickness in patients with unilateral branch retinal vein occlusion
Background: Associations between retinal venous occlusion (RVO), elevated intraocular pressure, and glaucoma have been reported. Further investigations into structural alterations in the fellow eyes of individuals with unilateral RVO have revealed that the peripapillary retinal nerve fiber layer is thinner than in healthy eyes, suggesting that there may be systemic risk factors common to both RVO and glaucoma. We aimed to evaluate changes in peripapillary retinal nerve fiber layer thickness (pRNFLT) among individuals with unilateral branch retinal vein occlusion (BRVO).
Methods: This prospective observational study recruited 30 individuals (60 eyes) with newly diagnosed unilateral BRVO and macular edema, and a control group of 30 healthy individuals (30 eyes) with no abnormalities on fundus examination or concurrent systemic comorbidities. After baseline measurements, the participants were reassessed at 6, 12, and 24 months by measuring global and sectoral pRNFLT using spectral-domain optical coherence tomography.
Results: The mean age and sex distributions were comparable between the patient and control groups (both P > 0.05). When compared to fellow eyes, global and sectoral pRNFLT in eyes with BRVO were significantly higher at baseline (all P < 0.05). Over time, pRNFLT decreased dramatically, and by the conclusion of the two-year follow-up, there was a significant reduction from baseline in the affected eyes (all P < 0.05). Likewise, affected eyes experienced a significant improvement in best-corrected distance visual acuity and central macular thickness over the two-year follow-up (both P Less than or equal to 0.001). Comparing the global and all-sector pRNFLT of fellow eyes in the patient group with those of normal eyes in the control group, there were no significant differences at any visit, except in the temporal sector, which revealed a significant reduction in pRNFLT at 24 months in the fellow eyes of patients with unilateral BRVO (P = 0.02).
Conclusions: Patients with unilateral BRVO experienced a significant reduction in pRNFLT in the affected eyes and, to a lesser extent, in the fellow eyes, compared with that of the control arm, suggesting that they are prone to retinal nerve fiber layer damage. The reduction in pRNFLT in the normal fellow eyes of patients with BRVO may be attributed to age or concurrent systemic comorbidities. Further studies with long follow-up periods are required to shed light on the etiology of functional and structural changes in both the retinal nerve fiber layer and ganglion cell complex in the normal and affected eyes of patients with unilateral BRVO
Characterization of greater middle eastern genetic variation for enhanced disease gene discovery
The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia1-3, has resulted in an elevated burden of recessive disease4. Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized ‘genetic purging’. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics
Mutation analysis of 18 nephronophthisis associated ciliopathy disease genes using a DNA pooling and next generation sequencing strategy
Background Nephronophthisis associated ciliopathies (NPHP-AC) comprise a group of autosomal recessive cystic kidney diseases that includes nephronophthisis (NPHP), Senior-Loken syndrome (SLS), Joubert syndrome (JBTS), and Meckel-Gruber syndrome (MKS). To date, causative mutations in NPHP-AC have been described for 18 different genes, rendering mutation analysis tedious and expensive. To overcome the broad genetic locus heterogeneity, a strategy of DNA pooling with consecutive massively parallel resequencing (MPR) was devised.Methods In 120 patients with severe NPHP-AC phenotypes, five pools of genomic DNA with 24 patients each were prepared which were used as templates in order to PCR amplify all 376 exons of 18 NPHP-AC genes (NPHP1, INVS, NPHP3, NPHP4, IQCB1, CEP290, GLIS2, RPGRIP1L, NEK8, TMEM67, INPP5E, TMEM216, AHI1, ARL13B, CC2D2A, TTC21B, MKS1, and XPNPEP3). PCR products were then subjected to MPR on an Illumina Genome-Analyser and mutations were subsequently assigned to their respective mutation carrier via CEL I endonuclease based heteroduplex screening and confirmed by Sanger sequencing.Results For proof of principle, DNA from patients with known mutations was used and detection of 22 out of 24 different alleles (92% sensitivity) was demonstrated. MPR led to the molecular diagnosis in 30/120 patients (25%) and 54 pathogenic mutations (27 novel) were identified in seven different NPHP-AC genes. Additionally, in 24 patients only single heterozygous variants of unknown significance were found.Conclusions The combined approach of DNA pooling followed by MPR strongly facilitates mutation analysis in broadly heterogeneous single gene disorders. The lack of mutations in 75% of patients in this cohort indicates further extensive heterogeneity in NPHP-AC
Piezoelectric Ring Actuator Technique to Monitor Early-Age Properties of Cement-based Materials
Piezoelectric ring actuator technique (P-RAT) that uses shear wave velocity (VS) was initially developed as a non-destructive test for soil characterization. The P-RAT was successfully modified to be adapted for cement-based materials in previous research by the co-authors. In the current study, validation of the P-RAT was carried out by comparing VS test results to those of conventional tests used to evaluate early-age properties of cementitious materials. Conventional tests included monitoring variation in penetration resistance for mortar, Vicat needle for paste, calorimetry, and electrical conductivity with time at early ages. The validation involved testing paste and mortar mixtures prepared with ordinary Portland cement and water-to-cement ratios (w/c) of 0.35-0.50 and different types and dosage rates of chemical admixtures. Test results showed that derivation of VS-versus-time curve obtained from the P-RAT can be employed to determine setting time. The variations of VS with time resulted in similar behaviour as those of the variations of heat of hydration and electrical conductivity with time. Fundamental relationships between VS results of the P-RAT and conventional tests to monitor setting were established. An analytical model to estimate the w/c at early age was proposed using the VS approach
Association of Toll-Like Receptor 3 and Toll-Like Receptor 9 Single Nucleotide Polymorphisms with Hepatitis C Virus Infection and Hepatic Fibrosis in Egyptian Patients
Lead, Mercury, and Cadmium Concentrations in Blood Products Transfused to Neonates: Elimination Not Just Mitigation
Lead (Pb), mercury (Hg), and cadmium (Cd) are identified as potent developmental neurotoxicants. Neonates are the main group receiving multiple blood transfusions. The exposure of neonates to these heavy metals (HMs) can occur through blood transfusions. This study aimed to determine the concentrations of lead (Pb), mercury (Hg), and cadmium (Cd) in various blood products (plasma, platelets, packed red blood cells (pRBCs), and whole blood (WB)) to explore the probability of concurrent exposure of these HMs and to identify the metal load per transfusion with risk assessment. Residual bloods from blood bank bags were collected after neonatal transfusion. Pb, Hg, and Cd concentrations were determined in 120 samples of blood products by inductively coupled plasma mass spectrometry (ICP-MS). Pb and Cd levels were over the normal levels in 19.2 and 5.9% of all blood units, respectively. In 35 and 0.8% of blood units, the Pb and Cd concentrations, respectively, were higher than that recommended for transfusions in premature neonates. The anticipated safe value was surpassed by 2.5% for Cd of all transfusions, primarily because of WB. However, Hg was detected only in 5.8% of all samples and their concentrations were within the normal range. The concurrent neonatal exposure to Pb, Hg, and Cd was statistically significant. Hazard quotients of Hg and Cr were >1 and Pb cancer risk was 2.41 × 10−4. To the best of our knowledge, this study is the first report examining Pb, Hg, and Cd in blood products other than WB and pRBCs using ICP-MS. This study demonstrated the exposure of neonates to Pb, Hg, and Cd during transfusion with a considerable amount of Pb. It confirms the significant concurrent exposure to the three HMs, which maximize their potential developmental neurotoxicity with a high probability of developing non-carcinogenic and carcinogenic health effects
Terretonin O: a new meroterpenoid from Aspergillus terreus.
Hamed A, Abdel-Razek AS, Omran DA, et al. Terretonin O: a new meroterpenoid from Aspergillus terreus. Natural product research. 2019:1-10
Efficacy of chloroquine and hydroxychloroquine in treating COVID-19 infection: A meta-review of systematic reviews and an updated meta-analysis
To synthesize findings from systematic reviews and meta-analyses on the efficacy and safety of chloroquine (CQ) and hydroxychloroquine (HCQ) with or without Azithromycin for treating COVID-19, and to update the evidence using a meta-analysis. A comprehensive search was carried out in electronic databases for systematic reviews, meta-analyses and experimental studies which investigated the efficacy and safety of CQ, HCQ with or without Azithromycin to treat COVID-19. Findings from the reviews were synthesised using tables and forest plots and the quality effect model was used for the updated meta-analysis. The main outcomes were mortality, the need for intensive care services, disease exacerbation, viral clearance and occurrence of adverse events. Thirteen reviews with 40 primary studies were included. Two meta-analyses reported a high risk of mortality, with ORs of 2.2 and 3.0, and the two others found no association between HCQ and mortality. Findings from two meta-analyses showed that HCQ with Azithromycin increased the risk of mortality, with similar ORs of 2.5. The updated meta-analysis of experimental studies showed that the drugs were not effective in reducing mortality (RR 1.1, 95%CI 1.0-1.3, I = 0.0%), need for intensive care services (OR 1.1, 95%CI 0.9-1.4, I = 0.0%), virological cure (OR 1.5, 95%CI 0.5-4.4, I = 39.6%) or disease exacerbation (OR 1.2, 95%CI 0.3-5.9, I = 31.9%) but increased the odds of adverse events (OR 12,3, 95%CI 2.5-59.9, I = 76.6%). There is conclusive evidence that CQ and HCQ, with or without Azithromycin are not effective in treating COVID-19 or its exacerbation. PROSPERO: CRD4202019135
Tensile Characterization of an “Eco-Friendly” UHPFRC with Waste Glass Powder and Glass Sand
A new type of ecofriendly ultra-high-performance glass concrete (UHPGC) was developed at the Université de Sherbrooke using waste glass with varying particle-size distributions (PSD). The compressive strength was higher than 150 MPa and mini-slump spread diameter higher than 250 mm (which resulted into a good self-compacting ability of the fluid mixture).
This paper presents the characterization of the tensile behavior of this advanced cementitious composite, since the post-cracking tensile performance is a fundamental mechanical characteristic of ultra-high-performance fiber-reinforced concrete (UHPFRC). Two UHPGC with different compositions were investigated in this study: one mixture containing glass powder as a cement replacement material and the other mixture containing glass powder and glass sand as a replacement of both binder and fine aggregates. Both mixtures contained 2% by volume of micro steel fiber with aspect ratio equal to 65. Two curing regime were used (hot curing and normal curing) and the effect of this different curing regime on the tensile behavior has been also investigated. A total of six sets of specimens were tested at different ages, equal to 28 and 91 days respectively, including, as a further experimental variable, the flow-induced alignment of the fibers. A novel experimental technique, called Double Edge Wedge Splitting Test (DEWS), recently developed at Politecnico di Milano, was employed to characterize the material tensile response. This is an indirect tensile test technique, in which a compressive load applied to the specimen is able to result into a tensile stress state over a critical ligament section suitably highlighted thanks to specimen geometry and loading set-up. The DEWS test is able, as demonstrated, to provide straightforwardly the tensile stress vs. crack opening response of the cementitious composite with no need for back analysis. The results highlight the possibility of obtaining a strain-hardening composite, also exploiting the favorable alignment of the fibers, and hence to produce a UHPFRC with significant sustainable signature, employing considerable amounts of waste material as cement and natural aggregate replacement