Cryptic Cerulenin Rearrangement in Ketosynthase Covalent Inhibition.

The antibiotic cerulenin is a fungal natural product identified as a covalent inhibitor of ketosynthases within fatty acid and polyketide biosynthesis. Due to its selective and potent inhibitory activity, cerulenin has found significant utility in multidisciplinary biochemical, biomedical, and clinical studies. Although its covalent inhibition profile has been confirmed, cerulenin's mechanism has not been fully determined at a molecular level, frustrating the drug development of related analogues. Herein, we describe the use of stable isotopic tracking with NMR and MS methods to unravel the covalent mechanism of cerulenin against type II fatty acid ketosynthases. We detail the discovery of a unique C2-C3 retro-aldol bond cleavage and a structural rearrangement upon covalent inhibition of cerulenin at the active cysteine residue in E. coli type II fatty acid ketosynthases FabB and FabF.

Effect of SARS-CoV-2 and Toxoplasma gondii co-infection on IFN-γ and TNF-α expression and its impact on disease severity.

The symptomatology of COVID-19 is dependent on the immune status and the cytokine response of the host. The cytokine level of the host is influenced by the presence of chronic persistent or latent infections with co-pathogens. Parasitic diseases are known to induce host immune-modulation which may impact the response to co-infection. Toxoplasmosis is a widespread protozoal infection that remains quiescent in its latent form to be re-activated during states of immune depression. Clinical data on the relation between toxoplasmosis and COVID-19 cytokine profile and symptomatology are still insufficient. Seventy-nine subjects were included in this study. Patients were diagnosed with COVID-19 by PCR. Serological testing for toxoplasmosis was performed by the detection of anti-Toxoplasma IgG antibodies, in addition to IgG avidity testing. IFN-γ and TNF-α levels were determined by RT-PCR. Among patients diagnosed with COVID-19, 67.1% were seronegative for anti-Toxoplasma IgG, while 32.9% were seropositive. High avidity was found in 10 cases (40% of seropositive cases), 4 of whom required ICU administration, while low avidity was found in 15 cases (60%), 7 of which were administered to the ICU. TNF-α and INF-γ levels were significantly higher in COVID-19 patients than in healthy control subjects. No significant association was found between the seroprevalence of toxoplasmosis and the presence of COVID-19 and its severity. Cytokines were significantly higher in both seropositive and seronegative COVID-19 patients than in their control counterparts. The high prevalence of toxoplasmosis merits further exploration of its relation to COVID-19 by mass studies.

Tracking the therapeutic efficacy of a ketone mono ester and ß-hydroxybutyrate for ulcerative colitis in rats: New perspectives.

Ulcerative colitis (UC) is an inflammatory condition that affects the colon's lining and increases the risk of colon cancer. Despite ongoing research, there is no identified cure for UC. The recognition of NLRP3 inflammasome activation in the pathogenesis of UC has gained widespread acceptance. Notably, the ketone body ß-hydroxybutyrate inhibits NLRP3 demonstrating its anti-inflammatory properties. Additionally, BD-AcAc 2 is ketone mono ester that increases ß-hydroxybutyrate blood levels. It has the potential to address the constraints associated with exogenous ß-hydroxybutyrate as a therapeutic agent, including issues related to stability and short duration of action. However, the effects of ß-hydroxybutyrate and BD-AcAc 2 on colitis have not been fully investigated. This study found that while both exogenous ß-hydroxybutyrate and BD-AcAc 2 produced the same levels of plasma ß-hydroxybutyrate, BD-AcAc 2 demonstrated superior effectiveness in mitigating dextran sodium sulfate-induced UC in rats. The mechanism of action involves modulating the NF-κB signaling, inhibiting the NLRP3 inflammasome, regulating antioxidant capacity, controlling tight junction protein expression and a potential to inhibit apoptosis and pyroptosis. Certainly, BD-AcAc 2's anti-inflammatory effects require more than just increasing plasma ß-hydroxybutyrate levels and other factors contribute to its efficacy. Local ketone concentrations in the gastrointestinal tract, as well as the combined effect of specific ketone bodies, are likely to have contributed to the stronger protective effect observed with ketone mono ester ingestion in our experiment. As a result, further investigations are necessary to fully understand the mechanisms of BD-AcAc 2 and optimize its use.

Discovery and biosynthesis of cyclic plant peptides via autocatalytic cyclases.

Many bioactive plant cyclic peptides form side-chain-derived macrocycles. Lyciumins, cyclic plant peptides with tryptophan macrocyclizations, are ribosomal peptides (RiPPs) originating from repetitive core peptide motifs in precursor peptides with plant-specific BURP (BNM2, USP, RD22 and PG1beta) domains, but the biosynthetic mechanism for their formation has remained unknown. Here, we characterize precursor-peptide BURP domains as copper-dependent autocatalytic peptide cyclases and use a combination of tandem mass spectrometry-based metabolomics and plant genomics to systematically discover five BURP-domain-derived plant RiPP classes, with mono- and bicyclic structures formed via tryptophans and tyrosines, from botanical collections. As BURP-domain cyclases are scaffold-generating enzymes in plant specialized metabolism that are physically connected to their substrates in the same polypeptide, we introduce a bioinformatic method to mine plant genomes for precursor-peptide-encoding genes by detection of repetitive substrate domains and known core peptide features. Our study sets the stage for chemical, biosynthetic and biological exploration of plant RiPP natural products from BURP-domain cyclases.

Dual SARS-CoV-2 and MERS-CoV inhibitors from Artemisia monosperma: isolation, structure elucidation, molecular modelling studies, and in vitro activities.

The COVID-19 pandemic has spread throughout the whole globe, so it is imperative that all available resources be used to treat this scourge. In reality, the development of new pharmaceuticals has mostly benefited from natural products. The widespread medicinal usage of species in the Asteraceae family is extensively researched. In this study, compounds isolated from methanolic extract of Artemisia monosperma Delile, a wild plant whose grows in Egypt's Sinai Peninsula. Three compounds, stigmasterol 3-O-ß-D-glucopyranoside 1, rhamnetin 3, and padmatin 6, were first isolated from this species. In addition, five previously reported compounds, arcapillin 2, jaceosidin 4, hispidulin 5, 7-O-methyleriodictyol 7, and eupatilin 8, were isolated. Applying molecular modelling simulations revealed two compounds, arcapillin 2 and rhamnetin 3 with the best docking interactions and energies within SARS-CoV-2 Mpro-binding site (-6.16, and -6.70 kcal mol-1, respectively). The top-docked compounds (2-3) were further evaluated for inhibitory concentrations (IC50), and half-maximal cytotoxicity (CC50) of both SARS-CoV-2 and MERS-CoV. Interestingly, arcapillin showed high antiviral activity towards SARS-CoV-2 and MERS-CoV, with IC50 values of 190.8 µg mL-1 and 16.58 µg mL-1, respectively. These findings may hold promise for further preclinical and clinical research, particularly on arcapillin itself or in collaboration with other drugs for COVID-19 treatment.

Clinicopathological characteristics and predictors of outcome of rapidly progressive glomerulonephritis: a retrospective study.

BACKGROUND: Globally, there are regional and time-based variations in the prevalence, etiology, and prognosis of rapidly progressive glomerulonephritis (RPGN). Prognosis of RPGN is poor, with a higher risk of death and end stage renal disease (ESRD) even with immunosuppressive medications. In the Middle East and North Africa, the studies on this disease are very limited. Therefore, we determined the predictors of outcome of RPGN. METHODS: We retrospectively assessed 101 adult patients over age of 18, diagnosed with RPGN based on renal biopsy illustrating crescents in ≥ 50% of the glomeruli. Patients who had crescents in their renal biopsies that were < 50% and those who refused to consent to a renal biopsy were excluded. We categorized the patients into 3 groups based on immunohistochemistry; type I, type II and type III. Then, depending on renal loss, we divided them into ESRD and non-ESRD groups. The clinical history and physical examination were retrieved. Additionally, 24-hour urine protein, urine analysis, renal function tests, serum albumin, complete blood count, antinuclear antibodies, anti-double stranded DNA antibodies, ANCA antibodies and serum complement levels were checked. Each patient underwent a kidney biopsy for immunohistochemistry and light microscopy. The percentage of crescentic glomeruli, number of sclerosed glomeruli, tertiary lymphoid organ (TLO), neutrophil infiltration, endocapillary or mesangial hypercellularity, interstitial fibrosis with tubular atrophy (IFTA) were analyzed. Primary outcomes (remission, ESRD and mortality) and secondary outcomes were assessed. RESULTS: Type II was the most frequent cause of RPGN (47.5%), followed by type III (32.7%) and type I (19.8%). 32 patients (31.7%) died during follow up, whereas 60 patients (59.4%) developed ESRD. In 41 patients (40.6%), remission occurred. Oliguria, serum creatinine, and need for HD at presentation were significantly increased in ESRD group compared to non-ESRD group (P < 0.001 for each). Mesangial proliferation, IFTA, TLO formation, sclerotic glomeruli and fibrous crescents were also significantly increased in ESRD group in comparison to non-ESRD group (P < 0.001 for each). Glomerulosclerosis (P = 0.036), and IFTA (P = 0.008) were predictors of ESRD. Infections (P = 0.02), respiratory failure (P < 0.001), and heart failure (P = 0.004) were mortality risk factors. CONCLUSION: Type II RPGN was the most common. Infection was the most frequent secondary outcome. Oliguria, glomerulosclerosis, the requirement for hemodialysis at presentation, IFTA and TLO formation were predictors of ESRD. Respiratory failure, heart failure and infections were significant predictors of mortality.

Effectiveness of bisphosphonate for alleviating tinnitus associated with otosclerosis: a prospective case-control study.

PURPOSE: To investigate the short-term efficacy of third-generation bisphosphonate in the management of tinnitus associated with otosclerosis. METHODS: A prospective case-control study included 100 patients with otosclerosis-associated bothersome tinnitus. Patients were assigned to two groups: group A (control): 25 patients who planned to receive only complementary supplements, oral vitamin D plus calcium, and group B (case): 75 patients who planned to receive oral bisphosphonate plus routine vitamin D and calcium supplements. Group B was subdivided into B1: 25 patients without any previous intervention, B2: 25 patients with persistent tinnitus for more than 6 months after a previous uncomplicated stapedotomy in the same ear, and B3: 25 patients with persistent tinnitus for more than 6 months after hearing aid fitting. The outcome was tinnitus assessment both subjectively (tinnitus intensity, frequency, and questionnaire) and objectively (tinnitus intensity and frequency). RESULTS: The female-to-male ratio was 1.6:1 with ages ranging from 40 to 61 years. The baseline revealed no statistically significant differences between the groups. After 6 months, there were statistically significant differences, both objectively and subjectively. The tinnitus questionnaire median (IQR) for group B was 16 (30), whereas control group A had 52 (24). The tinnitus severity median (IQR) for group B was 20 (30), compared to group A's 52 (42). After 6 months, 40% of the cases in group B demonstrated complete improvement, compared to 0% in control group A. CONCLUSION: We demonstrated significant tinnitus improvement in cases treated with bisphosphonate compared to the control group.

Remineralizing effect of NSF on artificial enamel caries.

INTRODUCTION: Nanotechnology offers new approaches and endless opportunities for remineralizing tooth decay without being toxic or causing allergies. This study aimed to determine the effect of nanosilver fluoride (NSF) on the remineralization potential of enamel caries-like lesions compared to 5% sodium fluoride varnish in permanent teeth. METHODS: Fifteen teeth (molars and premolars) were gathered, cleaned, and polished using a scaler. After sectioning the teeth mesiodistally and removing the roots, the thirty specimens were subjected to a demineralized solution to induce early enamel lesions and then assigned randomly into two equal groups. The test materials were applied, and then all the specimens were subjected to a pH cycling model for 30 days. DIAGNOdent and surface roughness were investigated, and an evaluation of the enamel Ca and P weight% for Ca/P ratio calculation was done using SEM-EDX to analyze the specimens at the end of the study. The data were analyzed using an independent t-test. RESULTS: The mean values for the DIAGNOdent measurements for NSF and NaF at baseline and after demineralization were not significantly different (p > 0.05). After treatment, NaF varnish showed a significantly higher mean DIAGNOdent measurement (11.8 ± 5.80) than NSF (4.7 ± 1.6). The mean surface roughness of the NaF group (1.64 ± 0.39) was much higher than NSF's mean surface roughness (1.07 ± 0.21). Specimens treated with NSF had statistically significant smoother surfaces (p < 0.001). The NSF group had a higher mean Ca/P ratio (2.9 ± 0.35) than NaF (2.2 ± 0.11). This difference was statistically significant (p = 0.012). CONCLUSION: The study reveals that nano silver fluoride is a more effective treatment than sodium fluoride varnish in enhancing teeth's clinical characteristics, particularly in terms of mineral content and surface roughness, suggesting it could be an improved strategy to prevent dental caries and maintain enamel integrity.

LC/MS-Based Metabolomics Reveals Chemical Variations of Two Broccoli Varieties in Relation to Their Anticholinesterase Activity: In vitro and In silico Studies.

Broccoli is commonly consumed as food and as medicine. However, comprehensive metabolic profiling of two broccoli varieties, Romanesco broccoli (RB) and purple broccoli (PB), in relation to their anticholinergic activity has not been fully disclosed. A total of 110 compounds were tentatively identified using UPLC-Q-TOF-MS metabolomics. Distinctively different metabolomic profiles of the two varieties were revealed by principal component analysis (PCA). Furthermore, by volcano diagram analysis, it was found that PB had a significantly higher content of phenolic acids, flavonoids, and glucosinolates, indicating the different beneficial health potentials of PB that demonstrated higher antioxidant and anticholinergic activities. Moreover, Pearson's correlation analysis revealed 18 metabolites, mainly phenolic and sulfur compounds, as the main bioactive. The binding affinity of these biomarkers to the active sites of acetyl- and butyryl-cholinesterase enzymes was further validated using molecular docking studies. Results emphasize the broccoli significance as a functional food and nutraceutical source and highlight its beneficial effects against Alzheimer's disease.

Arthroscopic distal clavicle resection versus conservation in patients with combined rotator cuff tears and acromioclavicular joint osteoarthritis.

PURPOSE: The most common cause of shoulder pain originating from the acromioclavicular (AC) joint is osteoarthritis, causing pain and disability. Operative Management of AC arthritis includes arthroscopic distal clavicle resection (DCR) and open clavicle resection. This study was conducted to evaluate the outcomes of isolated rotator cuff repair with conservative treatment of ACJ arthritis versus the combined resection of the distal clavicle with the repair of a rotator cuff tear, in cases with acromioclavicular arthritis. METHODS: A total of 46 patients with unilateral or bilateral combined rotator cuff tear and acromioclavicular arthritis were included, they were classified into 2 independent groups: Conservative group (23 patients), and DCR group (23 patients). All patients were subjected to full history taking, examination, pre and post-operative University of California at Los Angeles shoulder scoring scale (UCLA), Antero-Posterior and Zanca X-rays views, early and late complications. RESULTS: Mean age was (51 ± 9) years, males were predominant (56.5%). The average post-operative UCLA score was (31.1 ± 4.9), and the average time to return to work was (214 ± 22). (2.2%) of patients had early complications, (19.6%) had late complications, (32.6%) had > 24 h till 1st post-operative analgesia, and (87%) needed MgSO4 Injection. We found a highly significant increase in UCLA score measurements in the Conservative group, and a highly significant increase in UCLA score measurements in the DCR group (p < 0.01). But there was no difference between the 2 groups. CONCLUSION: Conventional conservative approach with arthroscopic rotator cuff repair and subacromial decompression has proven to be as effective as arthroscopic rotator cuff repair and subacromial decompression with DCR, in terms of efficacy and safety profiles in short term, but with more risks of potential hazards and cost with the DCR.

Bioherbicidal Activity and Metabolic Profiling of Allelopathic Metabolites of Three Cassia species using UPLC-qTOF-MS/MS and Molecular Networking.

INTRODUCTION: Compared to synthetic herbicides, natural products with allelochemical properties can inhibit weed germination, aiding agricultural output with less phytotoxic residue in water and soil. OBJECTIVES: To identify natural product extracts of three Cassia species; C. javanica, C. roxburghii, and C. fistula and to investigate the possible phytotoxic and allelopathic potential. METHODS: Allelopathic activity of three Cassia species extracts was evaluated. To further investigate the active constituents, untergated metabolomics using UPLC-qTOF-MS/MS and ion-identity molecular networking (IIMN) approach was performed to identify and determine the distribution of metabolites in different Cassia species and plant parts. RESULTS: We observed in our study that the plant extracts showed consistent allelopathic activity against seed germination (P < 0.05) and the inhibition of shoot and root development of Chenopodium murale in a dose-dependent manner. Our comprehensive study identified at least 127 compounds comprising flavonoids, coumarins, anthraquinones, phenolic acids, lipids, and fatty acid derivatives. We also report the inhibition of seed germination, shoot growth, and root growth when treated with enriched leaf and flower extracts of C. fistula, and C. javanica, and the leaf extract of C. roxburghii. CONCLUSION: The present study recommends further evaluation of Cassia extracts as a potential source of allelopathic compounds in agricultural systems.

The role of hypoxia on prostate cancer progression and metastasis.

Prostate cancer is the second most common cancer diagnosed in men and the fifth-leading cause of cancer death in men worldwide. Like any solid tumor, the hypoxic microenvironment of prostatic cancer drives hypoxia-inducible factors (HIFs) to mediate cell adaptions to hypoxic conditions. HIFs direct different signaling pathways such as PI3K/Akt/mTOR, NOX, and Wnt/ß-Catenin to tumor progression depending on the degree of hypoxia. HIFs regulate cytoskeleton protein expression, promoting epithelial-mesenchymal transition (EMT), which occurs when cancer cells lose cell-to-cell adhesions and start invasion and metastasis. Through activating pathways, the hypoxic microenvironment maintains the self-renewal, potency, and anti-apoptotic function of prostate cancer cells and induces tumor metastasis and transformation. These pathways could serve as a potential target for prostate cancer therapy. HIFs increase the expression of androgen receptors on cancer cells maintaining the growth and survival of prostate cancer and the development of its castration resistance. In this review, we elaborate on the role of hypoxia in prostatic cancer pathogenesis and different hypoxia-induced mechanisms.

Effectiveness of Venous Stenting for the Treatment of Lower Extremity Chronic Thrombotic Venous Obstruction.

BACKGROUND: Patients with venous hypertension (HTN) have significant morbidity and poor quality of life. Deep venous thrombosis (DVT) and congenital defects that led to chronic outflow blockage are frequent causes of venous HTN. It is known that the venovenous bypass has been the standard method used in the treatment of chronic iliofemoral vein occlusions. Percutaneous recanalization has earlier been shown to be technically possible. With venoplasty and stenting, we used an aggressive endovascular strategy to treat the iliofemoral venous thrombotic occlusion. METHODS: From May 2019 to April 2021, the medical records were reviewed for 63 patients diagnosed with symptomatic iliofemoral thrombotic occlusive disease and treated with venous stenting. The procedures' results were analyzed at Al-Azhar University Hospitals. RESULTS: The medical records of 63 cases (44 women with a median age of 49.52 years), with chronic outflow block of iliofemoral vein segment that were treated with endovascular venous stenting, were reviewed retrospectively. Optimal success was obtained in 56 cases (88.9%). The twelve-month primary, assisted primary, and secondary patency rates were 76.8%, 80.4%, and 87.5%, respectively, while it was 73.2%, 80.4%, and 87.5%, respectively, after 2 years. The procedure-related complication rate was 6.3%. Puncture site hematoma was observed in 2 patients (3.2%). Early (30 days) stent thrombosis occurred in 2 patients (3.2%). Most importantly, there was no procedure-related mortality. CONCLUSIONS: Endovascular treatment with balloon angioplasty and stenting of chronic venous thrombotic occlusions is an effective and safe procedure associated with a high technical rate of success and excellent patency rates. Accordingly, it should be considered the first line in the treatment of symptomatic iliofemoral vein occlusion.

Genetic variation of Sparicotyle chrysophrii (Monogenea: Microcotylidae) from the gilthead sea bream Sparus aurata (Teleostei: Sparidae) in the Mediterranean Sea.

The gill monogenean Sparicotyle chrysophrii (Van Beneden & Hesse, 1863) Mamaev, 1984 is a specific and common parasite of wild and cultured gilthead sea bream Sparus aurata Linnaeus, 1758, able to cause disease and mortality in aquaculture systems. Few molecular studies have been carried out on this monogenean, and its population structure and genetic diversity are barely known. This study provides the first contribution to the population genetic variation of S. chrysophrii, based on two molecular markers - the structural ribosomal RNA (rRNA) for the large subunit (28S) and the cytochrome c oxidase subunit I (COI) gene. Samples were collected from the gills of farmed and wild S. aurata from Italy and the Spanish Mediterranean. The analysis included previously published sequences. The 28S rDNA analysis was consistent with previous studies of specimens isolated from S. aurata and confirmed the presence of only one species on the gills of this host in the Mediterranean Sea. The COI sequences analysis suggested that the samples isolated in a previous study from a different host species, wild Boops boops (Linnaeus, 1758) in the Adriatic Sea, may represent a new undescribed sister species of S. chrysophrii. The low nucleotide diversity of S. chrysophrii isolated only from S. aurata versus the high haplotype diversity revealed small differences between haplotypes. The haplotypes shared between wild and farmed hosts from Spain provided the first molecular evidence of the possible transfer of S. chrysophrii between wild and farmed populations of S. aurata. The mtDNA COI analysis did not show a clear genetic structure, probably the result of several factors including coevolution, wild and farmed host interactions, and host population structure in space and time.

Cholinesterase Inhibitors from an Endophytic Fungus Aspergillus niveus Fv-er401: Metabolomics, Isolation and Molecular Docking.

Alzheimer's disease poses a global health concern with unmet demand requiring creative approaches to discover new medications. In this study, we investigated the chemical composition and the anticholinesterase activity of Aspergillus niveus Fv-er401 isolated from Foeniculum vulgare (Apiaceae) roots. Fifty-eight metabolites were identified using UHPLC-MS/MS analysis of the crude extract. The fungal extract showed acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects with IC50 53.44 ± 1.57 and 48.46 ± 0.41 µg/mL, respectively. Two known metabolites were isolated, terrequinone A and citrinin, showing moderate AChE and BuChE inhibitory activity using the Ellman's method (IC50 = 11.10 ± 0.38 µg/mL and 5.06 ± 0.15 µg/mL, respectively for AChE, and IC50 15.63 ± 1.27 µg/mL and 8.02 ± 0.08 µg/mL, respectively for BuChE). As evidenced by molecular docking, the isolated compounds and other structurally related metabolites identified by molecular networking had the required structural features for AChE and BuChE inhibition. Where varioxiranol G (-9.76 and -10.36 kcal/mol), penicitrinol B (-9.50 and -8.02 kcal/mol), dicitrinol A (-8.53 and -7.98 kcal/mol) and asterriquinone CT5 (-8.02 and -8.25 kcal/mol) showed better binding scores as AChE and BuChE inhibitors than the co-crystallized inhibitor (between -7.89 and 7.82 kcal/mol) making them promising candidates for the development of new drugs to treat Alzheimer's.

Knowledge, awareness, and perception of digital dentistry among Egyptian dentists: a cross-sectional study.

BACKGROUND: Digital dentistry has revolutionized the way dental treatment is offered to patients. It became essential for dental practitioners to be well-informed about this technology to improve the quality of care offered and increase patient satisfaction. This study aimed to assess the level of knowledge, awareness, and perception of Egyptian dentists toward digital dentistry. METHODS: An online-based cross-sectional study was conducted using social media platforms from November 2022 to March 2023. Our study sample included dentists with different levels of experience, specialties, and working in different health sectors in Egypt. A questionnaire arranged in 4 sections and 23 questions was used as the study data collection tool. The data were tabulated and analyzed using SPSS software. RESULTS: A total of 402 participants filled out this questionnaire. 50.7% of which were females, 42.8% were between 20-29 years old and 42.3% were general practitioners. Furthermore, the main practice of 27.6% was in governmental dental clinics. Moreover, 47.3% and 64.2% of participants had Moderate knowledge and awareness respectively. While 75.9% of them had a high perception of practicing digital dentistry. Females and practitioners in governmental clinics had significantly lower awareness scores, while faculty teaching staff had significantly higher scores (P ≤ 0.05). On the other hand, practicing in the Great Cairo region and urban areas was associated with significantly higher knowledge scores (P ≤ 0.05). Similarly, Prosthodontists, periodontists, and restorative dentists had significantly higher scores when compared with general dentists (P ≤ 0.05). CONCLUSIONS: About half of the study participants had Moderate knowledge and awareness levels, while about three-quarters of them had a high level of perception toward practicing digital dentistry. Therefore, more attention should be given to providing dental education programs in this important field at both the undergraduate and postgraduate levels by policymakers.

Detection of Nonsynonymous Single Variants in Human HLA-DRB1 Exon 2 Associated with Renal Transplant Rejection.

Background: HLA-DRB1 is the most polymorphic gene in the human leukocyte antigen (HLA) class II, and exon 2 is critical because it encodes antigen-binding sites. This study aimed to detect functional or marker genetic variants of HLA-DRB1 exon 2 in renal transplant recipients (acceptance and rejection) using Sanger sequencing. Methods: This hospital-based case-control study collected samples from two hospitals over seven months. The 60 participants were equally divided into three groups: rejection, acceptance, and control. The target regions were amplified and sequenced by PCR and Sanger sequencing. Several bioinformatics tools have been used to assess the impact of non-synonymous single-nucleotide variants (nsSNVs) on protein function and structure. The sequences data that support the findings of this study with accession numbers (OQ747803-OQ747862) are available in National Center for Biotechnology Information (GenBank database). Results: Seven SNVs were identified, two of which were novel (chr6(GRCh38.p12): 32584356C>A (K41N) and 32584113C>A (R122R)). Three of the seven SNVs were non-synonymous and found in the rejection group (chr6(GRCh38.p12): 32584356C>A (K41N), 32584304A>G (Y59H), and 32584152T>A (R109S)). The nsSNVs had varying effects on protein function, structure, and physicochemical parameters and could play a role in renal transplant rejection. The chr6(GRCh38.p12):32584152T>A variant showed the greatest impact. This is because of its conserved nature, main domain location, and pathogenic effects on protein structure, function, and stability. Finally, no significant markers were identified in the acceptance samples. Conclusion: Pathogenic variants can affect intramolecular/intermolecular interactions of amino acid residues, protein function/structure, and disease risk. HLA typing based on functional SNVs could be a comprehensive, accurate, and low-cost method for covering all HLA genes while shedding light on previously unknown causes in many graft rejection cases.

Metagenomic and Metatranscriptomic Insights into Population Diversity of Microcystis Blooms: Spatial and Temporal Dynamics of mcy Genotypes, Including a Partial Operon That Can Be Abundant and Expressed.

Cyanobacterial harmful algal blooms (cyanoHABs) degrade freshwater ecosystems globally. Microcystis aeruginosa often dominates cyanoHABs and produces microcystin (MC), a class of hepatotoxins that poses threats to human and animal health. Microcystin toxicity is influenced by distinct structural elements across a diversity of related molecules encoded by variant mcy operons. However, the composition and distribution of mcy operon variants in natural blooms remain poorly understood. Here, we characterized the variant composition of mcy genes in western Lake Erie Microcystis blooms from 2014 and 2018. Sampling was conducted across several spatial and temporal scales, including different bloom phases within 2014, extensive spatial coverage on the same day (2018), and frequent, autonomous sampling over a 2-week period (2018). Mapping of metagenomic and metatranscriptomic sequences to reference sequences revealed three Microcystis mcy genotypes: complete (all genes present [mcyA-J]), partial (truncated mcyA, complete mcyBC, and missing mcyD-J), and absent (no mcy genes). We also detected two different variants of mcyB that may influence the production of microcystin congeners. The relative abundance of these genotypes was correlated with pH and nitrate concentrations. Metatranscriptomic analysis revealed that partial operons were, at times, the most abundant genotype and expressed in situ, suggesting the potential biosynthesis of truncated products. Quantification of genetic divergence between genotypes suggests that the observed strains are the result of preexisting heterogeneity rather than de novo mutation during the sampling period. Overall, our results show that natural Microcystis populations contain several cooccurring mcy genotypes that dynamically shift in abundance spatiotemporally via strain succession and likely influence the observed diversity of the produced congeners. IMPORTANCE Cyanobacteria are responsible for producing microcystins (MCs), a class of potent and structurally diverse toxins, in freshwater systems around the world. While microcystins have been studied for over 50 years, the diversity of their chemical forms and how this variation is encoded at the genetic level remain poorly understood, especially within natural populations of cyanobacterial harmful algal blooms (cyanoHABs). Here, we leverage community DNA and RNA sequences to track shifts in mcy genes responsible for producing microcystin, uncovering the relative abundance, expression, and variation of these genes. We studied this phenomenon in western Lake Erie, which suffers annually from cyanoHAB events, with impacts on drinking water, recreation, tourism, and commercial fishing.

Efficacy of Preoperative Oral Midodrine in Preventing Hypotension After Spinal Anesthesia in Young Adults: A Randomized Controlled Trial.

BACKGROUND: Midodrine was effectively used for prophylaxis against hypotensive syndromes such as postural hypotension and intradialytic hypotension, and during the recovery phase of septic shock. In our study, we aimed to assess the efficacy of prophylactic administration of midodrine tablets before spinal anesthesia in reducing the occurrence of hypotension. METHODS: This randomized placebo-controlled study embraced 67 patients aged 18 to 40 years undergoing elective knee surgery under spinal anesthesia. Patients were randomized to midodrine group (given 10-mg tablets of midodrine) or placebo group (given placebo tablets), and tablets were administered 1 hour before spinal anesthesia (intrathecal injection of 12.5-mg 0.5% hyperbaric bupivacaine and 15-µg fentanyl). The primary outcome was the occurrence of hypotension, defined as a systolic blood pressure <90 mm Hg or <80% of baseline. Secondary outcomes were hemodynamic characteristics (mean arterial pressure [MAP] and heart rate [HR]) after spinal anesthesia, ephedrine dose, and occurrence of complications including bradycardia, vasovagal attacks, reactive hypertension nausea, vomiting, and shivering. RESULTS: The number of patients who became hypotensive after spinal anesthesia was 5 (14.7%) in midodrine group versus 14 (42.4%) in the placebo group; relative risk (95% confidence interval) was 0.35 (0.14-0.85) ( P = .021). The median (interquartile range) total dose of ephedrine was significantly lower in midodrine group 0 (0-10) mg than in placebo group (0 (0-15) mg; the Hodges-Lehmann median difference (95% confidence interval) was 0 (0-5) mg ( P = .015). For MAP data, the group × time interaction was significant ( P = .038), and the MAP was significantly lower in the placebo group than in the midodrine group after intrathecal injection at 2 minutes ( P = .047), 10 minutes ( P = .045), 15 minutes ( P < .001), 20 minutes ( P = .007), 30 minutes ( P =.013), 45 minutes ( P = .029), 60 minutes ( P = .029), and at the end of surgery ( P < .001). For HR data, the group × time interaction was nonsignificant ( P = .807), and the difference in means (95% confidence interval) between groups collapsing over time was -1.4 (-3.1 to 0.2) beats/min ( P = .096). There was no significant difference between the 2 groups regarding the occurrence of complications. CONCLUSIONS: Prophylactic administration of 10-mg midodrine tablets before spinal anesthesia is an effective method in the prevention of hypotension in young adult patients undergoing elective orthopedic knee surgery.

Identification of Antibacterial Metabolites from Endophytic Fungus Aspergillus fumigatus, Isolated from Albizia lucidior Leaves (Fabaceae), Utilizing Metabolomic and Molecular Docking Techniques.

The rapid spread of bacterial infection caused by Staphylococcus aureus has become a problem to public health despite the presence of past trials devoted to controlling the infection. Thus, the current study aimed to explore the chemical composition of the extract of endophytic fungus Aspergillus fumigatus, isolated from Albizia lucidior leaves, and investigate the antimicrobial activity of isolated metabolites and their probable mode of actions. The chemical investigation of the fungal extract via UPLC/MS/MS led to the identification of at least forty-two metabolites, as well as the isolation and complete characterization of eight reported metabolites. The antibacterial activities of isolated metabolites were assessed against S. aureus using agar disc diffusion and microplate dilution methods. Compounds ergosterol, helvolic acid and monomethyl sulochrin-4-sulphate showed minimal inhibitory concentration (MIC) values of 15.63, 1.95 and 3.90 µg/mL, respectively, compared to ciprofloxacin. We also report the inhibitory activity of the fungal extract on DNA gyrase and topoisomerase IV, which led us to perform molecular docking using the three most active compounds isolated from the extract against both enzymes. These active compounds had the required structural features for S. aureus DNA gyrase and topoisomerase IV inhibition, evidenced via molecular docking.