BLM helicase unwinds lagging strand substrates to assemble the ALT telomere damage response.

The Bloom syndrome (BLM) helicase is critical for alternative lengthening of telomeres (ALT), a homology-directed repair (HDR)-mediated telomere maintenance mechanism that is prevalent in cancers of mesenchymal origin. The DNA substrates that BLM engages to direct telomere recombination during ALT remain unknown. Here, we determine that BLM helicase acts on lagging strand telomere intermediates that occur specifically in ALT-positive cells to assemble a replication-associated DNA damage response. Loss of ATRX was permissive for BLM localization to ALT telomeres in S and G2, commensurate with the appearance of telomere C-strand-specific single-stranded DNA (ssDNA). DNA2 nuclease deficiency increased 5'-flap formation in a BLM-dependent manner, while telomere C-strand, but not G-strand, nicks promoted ALT. These findings define the seminal events in the ALT DNA damage response, linking aberrant telomeric lagging strand DNA replication with a BLM-directed HDR mechanism that sustains telomere length in a subset of human cancers.

Influence of honey bee (Apis mellifera) breeding on wing venation in Serbia and neighbouring countries.

In order to improve the productivity of honey bees (Apis mellifera), some of their traits are selected by breeding. On one hand, breeding is mainly based on the natural geographical variation of this species; on the other hand, mass production and distribution of artificially selected queens can significantly affect the natural geographic variation of honey bees. In this study, we have compared honey bee wings originating from breeding and non-breeding populations in Serbia. In the comparison, we have also used data from a large area of south-eastern Europe. The wings were measured using the 19 landmarks indicated on the wing images. The coordinates were analysed using the methodology of geometric morphometrics. We found that honey bees obtained from honey bee queen breeder differed in wing venation from surrounding populations, which are under natural selection. Therefore, we argue against including populations under artificial selection in the analysis of the natural geographical variation of honey bees. In our analysis of non-breeding samples, we found that in south-eastern Europe there is continuous variation in wing venation and no clear boundaries between A. m. carnica, A. m. cecropia, and A. m. macedonica.

Amycolatopsis mediterranei: A Sixty-Year Journey from Strain Isolation to Unlocking Its Potential of Rifamycin Analogue Production by Combinatorial Biosynthesis.

Ever since the isolation of Amycolatopsis mediterranei in 1957, this strain has been the focus of research worldwide. In the last 60 years or more, our understanding of the taxonomy, development of cloning vectors and conjugation system, physiology, genetics, genomics, and biosynthetic pathway of rifamycin B production in A. mediterranei has substantially increased. In particular, the development of cloning vectors, transformation system, characterization of the rifamycin biosynthetic gene cluster, and the regulation of rifamycin B production by the pioneering work of Heinz Floss have made the rifamycin polyketide biosynthetic gene cluster (PKS) an attractive target for extensive genetic manipulations to produce rifamycin B analogues which could be effective against multi-drug-resistant tuberculosis. Additionally, a better understanding of the regulation of rifamycin B production and the application of newer genomics tools, including CRISPR-assisted genome editing systems, might prove useful to overcome the limitations associated with low production of rifamycin analogues.

Masqueraders of pneumonia in children: A case series.

Pneumonia remains the top most killer of under-five Indian children. Pneumonia in children is usually caused by viral or bacterial infections. However, there are some unusual causes of pneumonia that merit consideration when pneumonia is recurrent or persistent.

The U- advancement Burrow's Flap in Persistent Tracheocutaneous Fistula. ~ Case Report.

Persistent tracheo-cutaneous fistulae necessitate a closure with pedicled or free flaps. The modality adopted is to reconstitute the anterior tracheal wall without compromising the tracheal lumen. We have developed the lateral U advancement Burrow's flap over the strap muscles and tracheal lateral fibrous flaps, to repair a large trachea-cutaneous fistula.

Molecular recognition of carbonate ion using a novel turn-on fluorescent probe.

A novel turn-on fluorescent probe 3 was synthesized by condensing salicylaldehyde and nicotinic hydrazide for the selective detection of CO32- in aqueous medium. Probe 3 exhibited a turn-on fluorescence response toward CO32- with excellent selectivity, sensitivity (DL = 2.76 µM), and good reversibility. The binding constant (K) of probe 3 with CO32- was calculated to be 5 × 103 M-1 (log K 3.69). The 1:1 stoichiometry of the complex between probe 3 and CO32- ions was confirmed by Job's plot and ESI-MS spectra. Deprotonation and hydrogen-bonding interactions are involved in the recognition of CO32- ion, which was also suggested by 1H NMR, ESI-MS spectra, and Density Functional Theory (DFT) calculations. Moreover, an INHIBIT type molecular logic gate was constructed by using 3:CO32- and CH3COOH as inputs and current signal as output. Owing to the practical applications, probe 3 demonstrated its efficiency in quantifying CO32- ion in real water samples through standard addition method, thus showcasing its potential in real environment. Further, the MTT assay indicated very low cytotoxicity (IC50 = 1 mM) of probe 3 and also the cell imaging experiments demonstrated the effective sensing of CO32- ions with probe 3 in the biological systems.

Structural-Based Virtual Screening of FDA-Approved Drugs Repository for NSP16 Inhibitors, Essential for SARS-COV-2 Invasion Into Host Cells: Elucidation From MM/PBSA Calculation.

NSP16 is one of the structural proteins of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) necessary for its entrance to the host cells. It exhibits 2'O-methyl-transferase (2'O-MTase) activity of NSP16 using methyl group from S-adenosyl methionine (SAM) by methylating the 5-end of virally encoded mRNAs and shields viral RNA, and also controls its replication as well as infection. In the present study, we used in silico approaches of drug repurposing to target and inhibit the SAM binding site in NSP16 using Food and Drug Administration (FDA)-approved small molecules set from Drug Bank database. Among the 2 456 FDA-approved molecules, framycetin, paromomycin, and amikacin were found to be significant binders against the SAM binding cryptic pocket of NSP16 with docking score of -13.708, -14.997 and -15.841 kcal/mol, respectively. Classical molecular dynamics (MD) simulation and molecular mechanics Poisson-Boltzmann surface area (MM/PBSA)-based binding free energy calculation depicted that all these three framycetin, paromomycin, and amikacin might be promising therapeutic leads towards SARS-CoV-2 infections via host immune escape inhibition pathway.

A systematic review on antimicrobial activities of green synthesised Selaginella silver nanoparticles.

BACKGROUND: Metallic nanoparticles from different natural sources exhibit superior therapeutic options as compared to the conventional methods. Selaginella species have attracted special attention of researchers worldwide due to the presence of bioactive molecules such as flavonoids, biflavonoids, triterpenes, steroids, saponins, tannins and other secondary metabolites that exhibit antimicrobial, antiplasmodial, anticancer and anti-inflammatory activities. Environment friendly green synthesised silver nanoparticles from Selaginella species provide viable, safe and efficient treatment against different fungal pathogens. OBJECTIVE: This systematic review aims to summarise the literature pertaining to superior antifungal ability of green synthesised silver nanoparticles using plant extracts of Selaginella spp. in comparison to both aqueous and ethanolic raw plant extracts by electronically collecting articles from databases. METHODS: The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis were taken into consideration while preparing this review. The titles and abstracts of the collected data were stored in Endnote20 based on the inclusion and exclusion criteria. The search strategy included literature from established sources like PubMed, Google Scholar and Retrieval System Online using subject descriptors. RESULTS: The search yielded 60 articles with unique hits. After removal of duplications, 46 articles were identified, 40 were assessed and only seven articles were chosen and included in this review based on our eligibility criteria. CONCLUSION: The physicochemical and preliminary phytochemical investigations of Selaginella suggest higher drug potency of nanoparticles synthesised from plant extract against different diseases as compared to aqueous and ethanolic plant extracts. The study holds great promise as the synthesis of nanoparticles involves low energy consumption, minimal technology and least toxic effects.

Candida auris in Dog Ears.

Candida auris is an emerging global public health threat and is resistant to most antifungal agents. Though fungi are significant pathogens for animals, the role of C. auris in animal health remains unexplored. Here, we analysed the microbial cultures of skin and ear swabs of 87 dogs in Delhi and performed fungal meta-barcode sequencing of ear and skin samples of 7 dogs with confirmed otitis externa (OE). Overall, 4.5% of dogs (4/87) with chronic skin infections contained evidence of C. auris in their ear canal (n = 3) and on their skin surface (n = 1). Of the three OE dogs with C. auris infection/colonisation, a diversity of fungi was observed, and their meta-barcode ITS sequence reads for C. auris ranged from 0.06% to 0.67%. Whole-genome sequencing of six C. auris strains obtained in culture from two dogs showed relatedness with Clade I clinical strains. The report highlights the isolation of C. auris from an animal source; however, the routes of transmission of this yeast to dogs and the clinical significance of transmission between dogs and humans remain to be investigated.

Short- and long-term safety and efficacy of corneal collagen cross-linking in progressive keratoconus: A systematic review and meta-analysis of randomized controlled trials.

PURPOSE: The purpose of the study is to evaluate the safety and outcomes of corneal collagen cross-linking (CXL) and different CXL protocols in progressive keratoconus (PK) population at short and long-term. MATERIALS AND METHODS: A systematic review and meta-analysis was conducted. A total of eight literature databases were searched (up to February 15, 2022). Randomized controlled trials (RCTs) comparing CXL versus placebo/control or comparing different CXL protocols in the PK population were included. The primary objective was assessment of outcomes of CXL versus placebo and comparison of different CXL protocols in terms of maximum keratometry (Kmax) or Kmax change from baseline (Δ), spherical equivalent, best corrected visual acuity (BCVA), and central corneal thickness (CCT) in both at short term (6 months) and long term (1st, 2nd, and 3rd year or more). The secondary objective was comparative evaluation of safety. For the meta-analysis, the RevMan5.3 software was used. RESULTS: A total of 48 RCTs were included. Compared to control, CXL was associated with improvement in Δ Kmax at 1 year (4 RCTs, mean difference [MD], -1.78 [-2.71, -0.86], P = 0.0002) and 2 and 3 years (1 RCT); ΔBCVA at 1 year (7 RCTs, -0.10 [-0.14, -0.06], P < 0.00001); and Δ CCT at 1 year (2 RCTs) and 3 years (1 RCT). Compared to conventional CXL (C-CXL), deterioration in Δ Kmax, ΔBCVA and endothelial cell density was seen at long term in the transepithelial CXL (TE-CXL, chemical enhancer). Up to 2 years, there was no difference between TE-CXL using iontophoresis (T-ionto) and C-CXL. At 2 and 4 years, C-CXL performed better compared to accelerated CXL (A-CXL) in terms of improving Kmax. Although CCT was higher in the A-CXL arm at 2 years, there was no difference at 4 years. While exploring heterogeneity among studies, selection of control eye (fellow eye of the same patient vs. eye of different patient) and baseline difference in Kmax were important sources of heterogeneity. CONCLUSION: CXL outperforms placebo/control in terms of enhancing Kmax and CCT, as well as slowing disease progression over time (till 3 years). T-ionto protocol, on the other hand, performed similarly to C-CXL protocol up to 2 years.

Evidence-Based Guidelines for the Management of Allergic Bronchopulmonary Aspergillosis (ABPA) in Children and Adolescents with Asthma.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) frequently complicates asthma. There is urgent need to develop evidence-based guidelines for the management of ABPA in children. The Evidence Based Guideline Development Group (EBGDG) of the Indian Academy of Pediatrics (IAP) National Respiratory Chapter (NRC) addressed this need. METHODS: The EBGDG shortlisted clinical questions relevant to the management of ABPA in asthma. For each question, the EBGDG undertook a systematic, step-wise evidence search for existing guidelines, followed by systematic reviews, followed by primary research studies. The evidence was collated, critically appraised, and synthesized. The EBGDG worked through the Evidence to Decision (EtD) framework, to formulate recommendations, using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: Seven clinical questions were prioritized, and the following recommendations formulated. (1) Children with poorly controlled asthma should be investigated for ABPA (conditional recommendation, moderate certainty of evidence). (2) Low dose steroid therapy regimen (0.5 mg/kg/d for the first 2 wk, followed by a progressive tapering) is preferable to higher dose regimens (conditional recommendation, very low certainty of evidence). (3) Oral steroid regimens longer than 16 wk (including tapering), should not be used (conditional recommendation, very low certainty of evidence). (4) Antifungals may or may not be added to steroid therapy as the evidence was neither in favour nor against (conditional recommendation, low certainty of evidence). (5) For clinicians using antifungal agents, the EBGDG recommends against using voriconazole instead of itraconazole (conditional recommendation, very low certainty of evidence). (6) No evidence-based recommendation could be framed for using pulse steroid therapy in preference to conventional steroid therapy. (7) Immunotherapy with biologicals including omalizumab or dupilumab is not recommended (conditional recommendation, very low certainty of evidence). CONCLUSIONS: This evidence-based guideline can be used by healthcare providers in diverse clinical settings.

Role of intravenous aspirin versus oral aspirin in the treatment of acute coronary syndrome: Answering a clinical query by systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Aspirin is indicated in the emergency management of acute coronary syndrome. However, oral aspirin has erratic bioavailability compared to i.v. formulation. OBJECTIVE: The objective of this study was to evaluate the comparative efficacy and safety of intravenous (IV) and oral aspirin in acute coronary syndrome. STUDY DESIGN: This was a systematic review and meta-analysis. RESULTS: Two randomized controlled trials were included. Compared to oral aspirin, lower platelet aggregability was seen with IV aspirin at 5 min and 20 min. Lower thromboxane B2 and lower platelet CD-62p levels were noted in the IV group; however, no significant difference was observed in terms of "composite cardiovascular death, stroke, and myocardial infarction (MI) at 4-6 weeks," "any cause mortality," "cardiovascular mortality," "occurrence of stroke," and "occurrence of MI/reinfarction." However, no difference was noted in terms of the occurrence of serious adverse events. CONCLUSION: IV aspirin showed some advantages in terms of platelet aggregability biomarkers at 20 min and 1 week with comparable safety to oral aspirin. No difference was seen in terms of clinical outcomes (at 24 h, 7, and 30 days) and the occurrence of serious adverse events.

A comprehensive insight on the challenges for COVID-19 vaccine: A lesson learnt from other viral vaccines.

The aim of this study is to comprehensively analyze previous viral vaccine programs and identify potential challenges and effective measures for the COVID-19 vaccine program. Previous viral vaccine programs, such as those for HIV, Zika, Influenza, Ebola, Dengue, SARS, and MERS, were evaluated. Paramount challenges were identified, including quasi-species, cross-reactivity, duration of immunity, revaccination, mutation, immunosenescence, and adverse events related to viral vaccines. Although a large population has been vaccinated, mutations in SARS-CoV-2 and adverse events related to vaccines pose significant challenges. Previous vaccine programs have taught us that predicting the final outcome of the current vaccine program for COVID-19 cannot be determined at a given state. Long-term follow-up studies are essential. Validated preclinical studies, long-term follow-up studies, alternative therapeutic approaches, and alternative vaccines are necessary.

Identification of Sesamin from Sesamum indicum as a Potent Antifungal Agent Using an Integrated in Silico and Biological Screening Platform.

Due to the limited availability of antifungal drugs, their relevant side effects and considering the insurgence of drug-resistant strains, novel antifungal agents are urgently needed. To identify such agents, we have developed an integrated computational and biological screening platform. We have considered a promising drug target in antifungal drug discovery (exo-1,3-ß-glucanase) and a phytochemical library composed of bioactive natural products was used. These products were computationally screened against the selected target using molecular docking and molecular dynamics techniques along with the evaluation of drug-like profile. We selected sesamin as the most promising phytochemical endowed with a potential antifungal profile and satisfactory drug-like properties. Sesamin was submitted to a preliminary biological evaluation to test its capability to inhibit the growth of several Candida species by calculating the MIC/MFC and conducting synergistic experiments with the marketed drug fluconazole. Following the screening protocol, we identified sesamin as a potential exo-1,3-ß-glucanase inhibitor, with relevant potency in inhibiting the growth of Candida species in a dose-dependent manner (MIC and MFC of 16 and 32 µg/mL, respectively). Furthermore, the combination of sesamin with fluconazole highlighted relevant synergistic effects. The described screening protocol revealed the natural product sesamin as a potential novel antifungal agent, showing an interesting predicted pharmacological profile, paving the way to the development of innovative therapeutics against fungal infections. Notably, our screening protocol can be helpful in antifungal drug discovery.

Structural insights into BCDX2 complex function in homologous recombination.

Homologous recombination (HR) fulfils a pivotal role in the repair of DNA double-strand breaks and collapsed replication forks1. HR depends on the products of several paralogues of RAD51, including the tetrameric complex of RAD51B, RAD51C, RAD51D and XRCC2 (BCDX2)2. BCDX2 functions as a mediator of nucleoprotein filament assembly by RAD51 and single-stranded DNA (ssDNA) during HR, but its mechanism remains undefined. Here we report cryogenic electron microscopy reconstructions of human BCDX2 in apo and ssDNA-bound states. The structures reveal how the amino-terminal domains of RAD51B, RAD51C and RAD51D participate in inter-subunit interactions that underpin complex formation and ssDNA-binding specificity. Single-molecule DNA curtain analysis yields insights into how BCDX2 enhances RAD51-ssDNA nucleoprotein filament assembly. Moreover, our cryogenic electron microscopy and functional analyses explain how RAD51C alterations found in patients with cancer3-6 inactivate DNA binding and the HR mediator activity of BCDX2. Our findings shed light on the role of BCDX2 in HR and provide a foundation for understanding how pathogenic alterations in BCDX2 impact genome repair.

Perception of care givers regarding danger signs of illness and practices followed in young infants (0-2 months) as per IMNCI at selected areas of Amritsar, Punjab: A qualitative study.

Background: In India, neonatal mortality contributes to over 64% of infant deaths, mostly occurring during the first week of life. Mortality rate in second month of life is also higher than at later ages. Delay in identification of warning signs of neonatal illness naturally postpones the initiation of treatment and referral to hospital. Materials and Methods: The study aimed to explore the perception of care givers regarding danger signs of illness and practices followed in young infants. Care givers who cared for the sick young infants during last six months were recruited using a convenient sampling technique and qualitative research approach. Five semi-structured interviews and one FGD were conducted using an interview and FGD guide. Data was analyzed manually by reading and rereading the transcribed verbatim leading to the emergence of themes, subthemes, and codes. Results: Data explored that excessive crying was perceived as a danger sign by entire mothers, and many of them were unable to recognize important warning signs. The delay in decision making for medical care-seeking also shows dwindling awareness. Additionally, mothers were adapting few unhygienic practices as home remedies leading to worsening the symptoms and making a call for additional infections which needs to be addressed by the health authorities at community level. Conclusion: Pronounced efforts are expected to raise mindfulness of mothers toward the significance of early identification of neonatal danger signs to stave off the high magnitude of neonatal mortality. Inclusion of excessive crying as neonatal danger sign is recommended as well.

Computer-aided diagnosis of autism spectrum disorder from EEG signals using deep learning with FAWT and multiscale permutation entropy features.

Autism spectrum disorder (ASD), a neurodevelopment disorder, is characterized by significant difficulties in social interaction and emerges as a major threat to children. Its computer-aided diagnosis used by neurologists improves the detection process and has a favorable impact on patients' health. Currently, a biomarker termed electroencephalography (EEG) is considered as vital tool to detect abnormal electrical activity in the brain. In this context, the present paper brings forth a novel approach for automated diagnosis of ASD from multichannel EEG signals using flexible analytic wavelet transform (FAWT). Firstly, this approach processes the acquired EEG signals with filtering and segmentation into short-duration EEG segments in the range of 5-20 s. These segmented EEG signals are decomposed into five levels using FAWT technique to obtain various sub-bands. Further, multiscale permutation entropy values are extracted from decomposed sub-bands which are used as feature vectors in the present work. Afterwards, these feature vectors are evaluated by traditional machine learning algorithms viz., k-nearest neighbor, logistic regression, support vector machine, and random forest, as well as convolutional neural network (CNN) as deep learning algorithm with different segment durations. The analysis of results reveals that CNN provides maximum accuracy, sensitivity, specificity, and area under the curve of 99.19%, 99.34%, 99.21%, and 0.9997, respectively, for 10 s duration EEG segment to identify ASD patients among healthy individuals. Thus, the proposed CNN architecture would be extremely helpful during diagnostic process of autism disease for neurologists.

Effect of Synthesis Methods and Conditions on Properties and Applications of Carbon Dots for the Detection of Potential Water Contaminants: A Review.

The worldwide pollution of water bodies by potential contaminants such as heavy metals, dyes, and pesticides etc. have severely affected the entire eco-system due to their toxic mobility and tough degradation in water. Consequently, there is a requirement to develop cost-competitive and easily handleable sensing materials which can detect targets sensitively and with selectivity. Among the low-cost sensory materials, carbon dots (CDs) constitute an important class of carbon nanomaterial with unique photostability, electronic and fluorescent properties. This review is an effort to comprehend the recent improvements in the sensing applications of CDs with prominence on synthetic routes, the effect of various synthesis parameters on physical properties (quantum yield, size range), detection mechanisms, and detection parameters (limit of detection, interference etc.). Particularly, the scope and progress for the detection of potential water contaminants using CDs have been explored and a holistic view of mechanisms of their detection has been included.

Holistic view of mechanisms for different types of signals generated by CDs.

Mechanistic investigation of formation of highly-dispersed silver nanoparticles using sea buckthorn extract.

Nowadays, the greener pathways for the synthesis of nanostructures are being explored. The extracts of different parts of plantsvizleaves, stems, and roots have been investigated. However, these extracts have been prepared by simply boiling or microwaving, or sonicating the parts of plants with water. Therefore, to have deeper insight and to investigate the full potential of plant extracts, serial extraction of leaves of sea buckthorn (Hippophae rhamnoides L.) which is a medicinally important plant was attempted using the soxhlet apparatus. The as-obtained polyphenolic-rich extract was employed for the preparation of silver nanoparticles (Ag-NPs). Under optimized reaction conditionsviz60 °C temperature and 500µl of extract solution (5 mg ml-1) highly disperse spherical nanoparticles of the average size of 15.8 ± 4.8 nm were obtained. Further, the optical band gap of Ag-NPs prepared using optimized reaction conditions was found to be 2.6 eV using the Tauc equation. Additionally, to understand the reduction by the extract, kinetic studies were also carried out which suggest the predominant occurrence of pseudo-first-order reaction. Furthermore, the mechanism of formation of Ag-NPs using major components of extractvizgallic acid and catechin which were identified by HPLC were also investigated using DFT. The mechanistic investigation was performed for both the keto-enol and radical-mediated preparation of Ag-NPs. Such theoretical investigations will help in the efficient designing of greener and novel routes for the synthesis of Ag-NPs. Additionally, the prepared silver was also employed for the colorimetric detection of H2O2.