Photo-catalytic dye degradation potentials of Ag-Pd bimetallic nanoparticles synthesized from Vitex negundo.

Plant extracts are a great alternative to synthesizing nanoparticles of different metals and metal oxides. This green synthesis method has opened up numerous possibilities in various scientific domains. In present study, Leaf extract from Vitex negundo is a non-deciduous, long-lasting shrub from the Verbenaceae family is used as capping and reducing agents for the synthesis of silver and palladium nanoparticles. The characterization study UV-vis spectrophotometer analysis showed absorbance value around 320 nm which confirming that Ag-Pd nanoparticles have been successfully obtained. Further, SEM is used to investigate the morphology of Ag-Pd NPs, which revealing their spherical and rod-like configuration, aggregation, and the size of the particles are obtained between 50 and 100 nm. The successful synthesis of Ag-Pd NPs was further confirmed by the EDAX chart, which displayed the peak of Ag and Pd at bending energies between 0.5 and 1.5 keV. According to the quantitative study, Ag and Pd ions found about 5.24 and 13.28%, respectively. In addition, surface studies with TEM confirming that synthesized Ag-Pd NPs are predominates with spheres structure morphologies, with sizes averaging 11.20 nm and ranging from 10 to 20 nm. Further, Ag-Pd nanoparticles was applied as potential photocatalyst materials to degrade methylene blue dye and found about 85% of the degradation efficiency within 150 min of the sunlight exposure thus could be used as catalyst to removal of hazardous organic dye molecules.

Bioeconomy and ethnopharmacology - Translational perspective and sustainability of the bioresources of northeast region of India.

ETHNOPHARMACOLOGICAL RELEVANCE: The ecological environment of Northeast region of India (NER), with its high humidity, has resulted in greater speciation and genetic diversity of plant, animal, and microbial species. This region is not only rich in ethnic and cultural diversity, but it is also a major biodiversity hotspot. The sustainable use of these bioresources can contribute to the region's bioeconomic development. AIM OF THE STUDY: The review aimed to deliver various perspectives on the development of bioeconomy from NER bioresources under the tenets of sustainable utilization and socioeconomic expansion. MATERIALS AND METHODS: Relevant information related to prospects of the approaches and techniques pertaining to the sustainable use of ethnomedicine resources for the growth of the bioeconomy were retrieved from PubMed, ScienceDirect, Google Scholar, Scopus, and Springer from 1984 to 2023. All the appropriate abstracts, full-text articles and various book chapters on bioeconomy and ethnopharmacology were conferred. RESULT: As the population grows, so does the demand for basic necessities such as food, health, and energy resources, where insufficient resource utilization and unsustainable pattern of material consumption cause impediments to economic development. On the other hand, the bioeconomy concept leads to "the production of renewable biological resources and the conversion of these resources and waste streams into value-added products. CONCLUSIONS: In this context, major emphasis should be placed on strengthening the economy's backbone in order to ensure sustainable use of these resources and livelihood security; in other words, it can boost the bio-economy by empowering the local people in general.

Incidence of carbapenem-resistant Escherichia coli ST2437 of clinical origin harbouring blaOXA-144 gene: a report from India.

AIMS: Carbapenem-resistant Escherichia coli has been categorized as a pathogen of critical priority by the World Health Organization as it is highly infectious with high mortality and morbidity rates and widespread transmission potential. Carbapenem resistance is primarily mediated by carbapenemase-encoding genes and, additionally, through intrinsic factors. In India, over the years, carbapenemase-encoding genes have been reported from diverse clinically significant pathogens. The present study identifies E. coli of clinical origin that harbours blaOXA-144. METHODS AND RESULTS: The study isolate was obtained from a tertiary referral hospital in northeast India. Carbapenemase production was investigated through culture on chromogenic agar and Rapidec Carba NP test as per manufacturer's instructions. Susceptibility of the isolate was performed by the Kirby-Bauer disc diffusion method and agar dilution method following CLSI guidelines. PCR targeting carbapenemase-encoding genes was performed, followed by transformation and conjugation experiments. Whole-genome sequencing of the isolate was done through the Illumina sequencing platform and the data were analysed using the Centre for Genomic Epidemiology database. BJD_EC180 is 6 919 180 bp in length and consists of six rRNA operons, 111 tRNA, and 6849 predicted protein-coding sequences. BJD_EC180 belonged to ST2437 and harboured the carbapenemase-encoding gene blaOXA-144 with ISAba1 upstream, along with multiple antibiotic resistance genes conferring clinical resistance towards beta-lactams, aminoglycosides, amphenicols, sulphonamides, tetracyclines, trimethoprim, and rifampin. CONCLUSIONS: Carbapenem-resistant E. coli harbouring blaOXA-144 associated with insertion sequence pose a serious health threat as their mobilization into carbapenem non-susceptible strains that will contribute to the resistance burden and therefore, needs urgent monitoring.

Preclinical assessment of MAGMAS inhibitor as a potential therapy for pediatric medulloblastoma.

Medulloblastoma, the most common pediatric brain malignancy, has Sonic Hedgehog (SHH) and non-SHH group3 subtypes. MAGMAS (Mitochondrial Associated Granulocyte Macrophage colony-stimulating factor Signaling molecules) encode for mitochondrial import inner membrane translocase subunit and is responsible for translocation of matrix proteins across the inner membrane. We previously reported that a small molecule MAGMAS inhibitor, BT9, decreases cell proliferation, migration, and oxidative phosphorylation in adult glioblastoma cell lines. The aim of our study was to investigate whether the chemotherapeutic effect of BT9 can be extended to pediatric medulloblastoma. Methods: Multiple in vitro assays were performed using human DAOY (SHH activated tp53 mutant) and D425 (non-SHH group 3) cells. The impact of BT9 on cellular growth, death, migration, invasion, and metabolic activity were quantified using MTT assay, TUNEL staining, scratch wound assay, Matrigel invasion chambers, and seahorse assay, respectively. Survival following 50mg/kg BT9 treatment was assessed in vivo in immunodeficient mice intracranially implanted with D425 cells. Results: Compared to control, BT9 treatment led to a significant reduction in medulloblastoma cell growth (DAOY, 24hrs IC50: 3.6uM, 48hrs IC50: 2.3uM, 72hrs IC50: 2.1uM; D425 24hrs IC50: 3.4uM, 48hrs IC50: 2.2uM, 72hrs IC50: 2.1uM) and a significant increase in cell death (DAOY, 24hrs p=0.0004, 48hrs p<0.0001; D425, 24hrs p=0.0001, 48hrs p=0.02). In DAOY cells, 3uM BT9 delayed migration, and significantly decreased DAOY and D425 cells invasion (p < 0.0001). Our in vivo study, however, did not extend survival in xenograft mouse model of group3 medulloblastoma compared to vehicle-treated controls. Conclusions: Our in vitro data showed BT9 antitumor efficacy in DAOY and D425 cell lines suggesting that BT9 may represent a promising targeted therapeutic in pediatric medulloblastoma. These data, however, need to be further validated in animal models.

Technological and economic analysis of electrokinetic remediation of contaminated soil: A global perspective and its application in Indian scenario.

Globally million hectares of land annually is getting contaminated by heavy metalloids like As, Cd, Cr, Hg, Pb, Co, Cu, Ni, Zn, and Se, with current concentrations in soil above geo-baseline or regulatory standards. The heavy metals are highly toxic, mobile, and persistent and hence require immediate and effective mitigation. There are many available remediation techniques like surface capping, encapsulation, landfilling, soil flushing, soil washing, electrokinetic extraction, stabilization, solidification, vitrification, phytoremediation, and bioremediation which have been evolved to clean up heavy metal-contaminated sites. Nevertheless, all of the technologies have some applicability and limitations making the soil remediation initiative unsustainable. Among the available technologies, electrokinetic remediation (EKR) has been comparatively recognized to mitigate contaminated sites via both in-situ and ex-situ approaches due to its efficiency, suitability for use in low permeability soil, and requirement of low potential gradient. The work critically analyzes the EKR concerning techno, economic, and sustainability aspect for evaluating its application on various substrates and environmental conditions. The current soil contamination status in India is presented and the application of EKR for the heavy metal remediation from soil has been evaluated. The present work summaries a comprehensive and exhaustive review on EKR technology proving its effectiveness for a country like India where the huge amount of waste generated could not be treated due to lack of infrastructure, technology, and economic constraints.

Comparing the Biofilm Removal Capacity of NaOCl, Povidone-Iodine, Chlorhexidine, Curcumin, and Triphala as Endodontic Irrigants.

BACKGROUND AND AIM: A sessile multicellular organism that is immersed in a self-produced matrix of extracellular polymeric substances and has its cells firmly attached to a surface is referred to as a microbial biofilm. When it comes to pulp and periradicular pathosis, biofilms are crucial. To reduce the number of microorganisms in the root canal and assist in treating periapical pathosis, endodontic therapy must include decontamination of the system of tooth root canals through biomechanical preparation and irrigation of the root canal. This study compares sodium hypochlorite (NaOCl), povidone-iodine, chlorhexidine, curcumin, and triphala as endodontic irrigating solutions regarding their capacity to eliminate biofilm from root canals. MATERIALS AND METHODS: A total of 60 patients were included if they had pulpitis. Two specific samples (samples A and B) were chosen for analysis from a collection of samples so that their bacterial composition is most similar to that of acute pulpitis. The suspensions of bacterial cells from this polymicrobial culture have been collected from frozen stock and then regrown by inoculation on Columbia agar base (Basingstoke, UK) with the addition of vitamin K1, hemin, and 5% (v/v) calf blood. The pureness of the suspensions was assessed using colony morphology and Gram staining. Analytical profile index (API) 20A tests or automated test for bacteria (ATB) ID 32A tests were initially used to identify the isolates. These polymicrobial cultures' in vitro biofilms were developed using membrane filters made of cellulose nitrate. The tested irrigating solutions were as follows: 5.25% sodium hypochlorite, 10% triphala, 0.2% chlorhexidine gluconate, 10% povidone-iodine, and 5% curcumin (CUR). On the other hand, phosphate-buffered saline was taken as a control agent. RESULTS: As the standard of excellence in endodontic irrigation, NaOCl has eliminated all germs in sample A following 15 minutes of culture and in both of the specimens after 40 minutes. Iodine also eliminated all germs after 40 minutes of administration, indicating that it would be worth exploring using iodine as a potential endodontic irrigant. Iodine achieved total bacterial elimination after 40 minutes in both samples; however, it was less effective after 15 minutes. Our findings indicate that iodine solution is the most suitable alternative after the supremely effective NaOCl, although it requires longer contact times to generate the necessary and recognized broad-spectrum antibacterial properties, including in the case of biofilms. Furthermore, curcumin also showed significant results after NaOCl and iodine. CONCLUSION: The antibacterial potency of each studied irrigant was significant, supporting their usage in endodontics. It was observed that NaOCl has the maximum antibacterial activity.

Knowledge, Awareness, and Practice of Pediatricians Regarding Infant Oral Health Care and Early Childhood Caries in the State of Assam, India.

BACKGROUND AND AIM: Pediatricians are the first point of contact for evaluating a child's health. Hence, our study was done to evaluate the knowledge, awareness, and practice of pediatricians regarding infant oral health care and early childhood caries (ECC) in the state of Assam. METHODS: A close-ended questionnaire was circulated among the pediatricians of Assam. Data regarding knowledge, awareness, and practice involving the oral health of children and ECC was collected. RESULTS: A total of 110 pediatricians participated in the study and the data obtained was subjected to chi-square analysis. Most of the participants (n=64, 67%) displayed adequate knowledge regarding dental caries and the way to identify them. Although most of the participants knew about practices leading to dental caries, they were lacking in knowledge regarding the deleterious effect of bottle feeding and related habits 65 (50-60%). Also, most of the participants (n=69, 62%) failed to educate the caregivers of the child regarding early dental visits. CONCLUSION: The majority of pediatricians displayed adequate knowledge regarding dental caries and their prevention but failed to educate the parents and caregivers of children regarding the importance of first dental visits and the maintenance of oral health.

Dual targeting of mitochondrial Lon peptidase 1 and chymotrypsin-like protease by small molecule BT317, as potential therapeutics in malignant astrocytoma.

Malignant astrocytomas are aggressive glioma tumors characterized by extensive hypoxia-induced, mito-chondria-dependent changes such as altered respiration, increased chymotrypsin-like (CT-L) proteasome activity, decreased apoptosis, drug resistance, stemness and increased invasiveness. Mitochondrial Lon Peptidase I (LonP1) overexpression and increased CT-L proteasome inhibitors activity are the biomarkers of aggressive high grade glioma phenotype, poor prognosis and found to be associated with recurrence and poor patient survival, and drugs targeting either LonP1 or the CT-L activity have anti-glioma activity in pre-clinical models. We here for the first time introduced and evaluated a novel small molecule, BT317, derived from coumarinic compound 4 (CC4) using structure-activity modeling which we found to inhibit both LonP1 and CT-L proteasome activity. Using gain-of-function and loss-of-function genetic models, we dis-covered that BT317 is more effective than the individual LonP1 or CT-L inhibition in increasing reactive oxy-gen species (ROS) generation and inducing apoptosis in high-grade astrocytoma lines. In vitro, BT317 had activity as a single agent but, more importantly, enhanced synergy with the standard of care commonly used chemotherapeutic temozolomide (TMZ). In orthotopic xenograft, patient derived glioma models, BT317 was able to cross the blood-brain barrier, to show selective activity at the tumor site and to demonstrate therapeutic efficacy both as a single agent and in combination with TMZ. BT317 defines an emerging class of dual LonP1, and CT-L proteasome inhibitors exhibited promising anti-tumor activity and could be a promising candidate for clinical translation in the space of malignant astrocytoma therapeutics.

Immobilization of α-amylase in calcium alginate-gum odina (CA-GO) beads: An easily recoverable and reusable support.

A natural polysacharide, gum odina was collected from Odina wodier tree and purified. Purified gum odina was used with sodium alginate for immobilization of α-amylase. Calcium alginate-gum odina (CA-GO) beads were prepared by ionotropic gelation method to find the improvement of immobilization efficiency and reusability of α-amylase over calcium alginate (CA) beads. XRD, SEM, FTIR, beads diameter, enzyme leaching from beads, moisture content, total soluble matter and swelling study have been carried out to understand the physical morphology and mechanism of immobilization of enzyme in beads matrix. It has been observed that if the polymer ratio changes (keeping enzyme conc. & calcium Chloride conc. constant) then the size and shape of the beads will vary and at a particular range of polymer ratio, the optimal beads forms. At a certain conc.(4%w/v of SA and 1%w/v GO), the immobilization efficiency of CA-GO and CA beads were 92.71 ± 0.85 % (w/w) and 89.19 ± 0.35 %(w/w) respectively. After 8th time use, the CA-GO beads remain (~4 fold) more active than that of CA beads. The FTIR confirms that GO does not interfere with α-Amylase and alginate. Here, it can be concluded that CA-GO beads show better efficiency in respect to immobilization, reusability than CA beads only.

Evaluation of a novel chromogenic screening method for detection of carbapenem-resistant Escherichia coli.

Introduction. Early detection of carbapenem-resistant Escherichia coli (CREco), categorized as a critical priority pathogen by the World Health Organization (WHO), is crucial in optimizing therapeutic options and to thwart outbreaks in clinical settings.Gap statement. The need of the hour is a diagnostic method that can detect carbapenem resistance conferred by intrinsic or acquired carbapenem resistance mechanisms or both.Aim. The study investigates the performance of a novel screening chromogenic method for detection of CREco.Methodology. Carbapenem-susceptible (n=23) and non-susceptible (n=90) E. coli were used to investigate the efficiency of the blue chromogenic test. All of the isolates were received from a tertiary referral hospital in Silchar, India and subjected to the blue chromogenic test and observed for colour change. A colour change from colourless to blue is interpreted as a positive result. The test results were further compared with available methods for detection of carbapenem resistance conferred by carbapenemase production or other carbapenem resistance mechanisms.Results. The blue chromogenic test generated 100 % (CI: 95.98-100 %) sensitive and 100 % (CI: 85.75-100 %) specific results for the detection of CREco with no false-positive or false-negative results. Within 3 h after incubation, the test detects all CREco with carbapenemase activity. Additionally, the blue chromogenic test also positively detected E. coli harbouring carbapenemase variants and with efflux and porin activity, compared to other phenotypic-based approaches.Conclusion. The study highlights a novel method that is highly sensitive and specific, inexpensive, rapid and user-friendly for the detection of CREco. With the surge and expansion of CREco, this sensitive, specific, user-friendly and inexpensive method can be used in laboratories with limited facilities for early detection of CREco, thereby improving infection control along with averting future outbreaks.

Electrochemical oxidation of azo dyes degradation by RuO2-IrO2-TiO2 electrode with biodegradation Aeromonas hydrophila AR1 and its degradation pathway: An integrated approach.

Azo dyes are the most varied class of synthetic chemicals with non-degradable characteristics. They are complex compounds made up of many different parts. It was primarily utilized for various application procedures in the dyeing industry. Therefore, it's crucial to develop an economical and environmentally friendly approach to treating azo dyes. Our present investigation is an integrated approach to the electrooxidation (EO) process of azo dyes using RuO2-IrO2-TiO2 (anode) and titanium mesh (cathode) electrodes, followed by the biodegradation process (BD) of the treated EO dyes. Chemical oxygen demand (COD) removal efficiency as follows MB (55%) ≥ MR (45%) ≥ TB (38%) ≥ CR (37%) correspondingly. The fragment generated during the degradation process which was identified with high-resolution mass spectrometry (HRMS) and its degradation mechanism pathway was proposed as demethylation reaction and N-N and C-N/C-S cleavage reaction occurs during EO. In biodegradation studies by Aeromonas hydrophila AR1, the EO treated dyes were completely mineralized aerobically which was evident by the COD removal efficiency as MB (98%) ≥ MR (92.9%) ≥ TB (88%) ≥ CR (87%) respectively. The EO process of dyes produced intermediate components with lower molecular weights, which was effectively utilized by the Aeromonas hydrophila AR1 and resulted in higher degradation efficiency 98%. We reported the significance of the enhanced approach of electrochemical oxidation with biodegradation studies in the effective removal of the pollutants in dye industrial effluent contaminated water environment.

Emergence of carbapenem-resistant enterobacterales co-harboring blaOXA-78 and blaOXA-58 from India.

BACKGROUND: Carbapenem-Resistant Enterobacterales (CRE) has been categorized as pathogens of critical priority by World Health organization (WHO) as they pose significant threat to global public health. Carbapenemase production considered as the principal resistance mechanism against carbapenems and with the recent surge and expansion of carbapenemases and its variants among clinically significant bacteria in India, the present study reports expansion blaOXA-78 and blaOXA-58 of in CRE of clinical origin. METHODS: Bacterial isolates were collected from a tertiary referral hospital and identified through VITEK® 2 Compact automated System (Biomerieux, France). Rapidec® Carba NP (Biomerieux, France) was used to investigate carbapenemase production followed by antibiotic susceptibility testing through Kirby-Bauer Disc Diffusion method and agar dilution method. Class D carbapenemase genes were targeted through PCR assay followed by investigation of horizontal transmission of blaOXA-58 and blaOXA-78. Whole genome sequencing was carried out using Illumina platform to investigate the genetic context of blaOXA-58 and blaOXA-78 genes and further characterization of the CRE isolates. RESULTS: The carbapenem-resistant Escherichia coli (BJD_EC456) and Serratia marcescens (BJD_SM81) received during the study from the tertiary referral hospital were isolated from sputum and blood samples respectively. PCR assay followed by whole genome sequencing revealed that the isolates co-harbor blaOXA-58 and blaOXA-78, a variant of blaOXA-51. Horizontal transfer of blaOXA-58 and blaOXA-78 genes were unsuccessful as these genes were located on the chromosome of the study isolates. Transposon Tn6080 was linked to blaOXA-78 in the upstream region while the insertion sequences ISAba26 and ISCfr1 were identified in the upstream and downstream region of blaOXA-58 gene respectively. In addition, both the isolates were co-harboring multiple antibiotic resistance genes conferring clinical resistance towards beta-lactams, aminoglycosides, fluroquinolones, sulphonamides, tetracyclines. BJD_EC180 belonged to ST2437 while BJD_SM81 was of an unknown sequence type. The nucleotide sequences of blaOXA-78 (OQ533021) and blaOXA-58 (OQ533022) have been deposited in GenBank. CONCLUSIONS: The study provides a local epidemiological information regarding carbapenem resistance aided by transposon and insertion sequences associated blaOXA-78 and blaOXA-58 genes associated and warrants continuous monitoring to prevent their further dissemination into carbapenem non-susceptible strains thereby contributing to carbapenem resistance burden which is currently a global concern.

Socio-economic sustainability with circular economy - An alternative approach.

As the global population and living standards rise, it pushes the demand for basic amenities like food, health, and energy resources. Additionally, manufacturing automation has led to mass production and consumption, triggering waste production. The existing linear economy approach has led to increasing waste production and resource depletion, posing significant environmental and public health threats. To overcome these impediments, an alternative model called the circular economy concept has gained popularity in the global industry community. This closed-loop, restorative, waste-free concept has the potential to protect the environment and improve economics by reducing energy and resource consumption. Thus, major impetus should be given to strengthening the backbone of the economy where tools such as green technologies, decarbonization strategies, bio refinery processes, material flow analysis, life cycle assessment, ecological footprints (water, carbon, and material), substance flow analysis, circularity index, eco-designing, bioresource management, new business models, and policy play an essential role in the areas of socio-economic sustainability, ecological facts, and industrial aspects to enhance socio-economic growth in a sustainable manner. Sectoral awareness, collaborations, and partnerships among the Government, stakeholders, policymakers, and competent authorities are also essential to enabling circularity within the eco-systems.

Imipenem and meropenem influence the Las/Rhl quorum-sensing systems in clinical isolates of Pseudomonas aeruginosa.

The present study was conducted to study the influence of imipenem and meropenem at subinhibitory concentration on the transcriptional response of Las/Rhl quorum-sensing systems in isolates of Pseudomonas aeruginosa. In the present study, six representative carbapenem nonsusceptible clinical isolates of P. aeruginosa were obtained. The agar dilution method was used to determine the minimum inhibitory concentration against imipenem and meropenem. The bacterial isolates were then cultured up to the early log phase in fresh Luria Bertani (LB) broths at 37°C with and without 2 µg mL-1 imipenem and meropenem, respectively. mRNA was then isolated from the bacterial isolates and was immediately reverse-transcribed to cDNA. The relative quantity of the expression of the lasI, lasR, rhlI, and rhlR genes was assessed by quantitative real-time Polymerase Chain Reaction (PCR) using the ΔΔCt method. The transcriptional response of the lasI and lasR genes was upregulated at subinhibitory concentration of meropenem. In contrast, the transcriptional response of the lasI, lasR, and rhlR genes was downregulated at subinhibitory concentration of imipenem as compared to the expression in untreated isolates. The data obtained in the current study showcased the ability of imipenem and meropenem to influence the response of the quorum-sensing genes at subinhibitory concentration.

HCK induces macrophage activation to promote renal inflammation and fibrosis via suppression of autophagy.

Renal inflammation and fibrosis are the common pathways leading to progressive chronic kidney disease (CKD). We previously identified hematopoietic cell kinase (HCK) as upregulated in human chronic allograft injury promoting kidney fibrosis; however, the cellular source and molecular mechanisms are unclear. Here, using immunostaining and single cell sequencing data, we show that HCK expression is highly enriched in pro-inflammatory macrophages in diseased kidneys. HCK-knockout (KO) or HCK-inhibitor decreases macrophage M1-like pro-inflammatory polarization, proliferation, and migration in RAW264.7 cells and bone marrow-derived macrophages (BMDM). We identify an interaction between HCK and ATG2A and CBL, two autophagy-related proteins, inhibiting autophagy flux in macrophages. In vivo, both global or myeloid cell specific HCK-KO attenuates renal inflammation and fibrosis with reduces macrophage numbers, pro-inflammatory polarization and migration into unilateral ureteral obstruction (UUO) kidneys and unilateral ischemia reperfusion injury (IRI) models. Finally, we developed a selective boron containing HCK inhibitor which can reduce macrophage pro-inflammatory activity, proliferation, and migration in vitro, and attenuate kidney fibrosis in the UUO mice. The current study elucidates mechanisms downstream of HCK regulating macrophage activation and polarization via autophagy in CKD and identifies that selective HCK inhibitors could be potentially developed as a new therapy for renal fibrosis.

Identification of new hit to lead magmas inhibitors as potential therapeutics for glioblastoma.

In continuation of our previous efforts for the development of potent small molecules against brain cancer, herein we synthesized seventeen new compounds and tested their anti-gliomapotential against established glioblastoma cell lines, namely, D54MG, U251, and LN-229 as well as patient derived cell lines (DB70 and DB93). Among them, the carboxamide derivatives, BT-851 and BT-892 were found to be the most active leads in comparison to our established hit compound BT#9.The SAR studies of our hit BT#9 compound resulted in the development of two new lead compounds by hit to lead strategy. The detailed biological studies are currently underway. The active compounds could possibly act as template for the future development of newer anti-glioma agents.

Intrinsic giant magnetoresistance due to exchange-bias-type effects at the surface of single-crystalline NiS2 nanoflakes.

The coexistence of different properties in the same material often results in exciting physical effects. At low temperatures, the pyrite transition-metal disulphide NiS2 hosts both antiferromagnetic and weak ferromagnetic orders, along with surface metallicity dominating its electronic transport. The interplay between such a complex magnetic structure and surface-dominated conduction in NiS2, however, is still not understood. A possible reason for this limited understanding is that NiS2 has been available primarily in bulk single-crystal form, which makes it difficult to perform studies combining magnetometry and transport measurements with high spatial resolution. Here, NiS2 nanoflakes are produced via mechanical cleaving and exfoliation of NiS2 single crystals and their properties are studied on a local (micron-size) scale. Strongly field-asymmetric magnetotransport features are found at low temperatures, which resemble those of more complex magnetic thin film heterostructures. Using nitrogen vacancy magnetometry, these magnetotransport features are related to exchange-bias-type effects between ferromagnetic and antiferromagnetic regions forming near step edges at the nanoflake surface. Nanoflakes with bigger steps exhibit giant magnetoresistance, which suggests a strong influence of magnetic spin textures at the NiS2 surface on its electronic transport. These findings pave the way for the application of NiS2 nanoflakes in van der Waals heterostructures for low-temperature spintronics and superconducting spintronics.

Effects of retinoic acid receptor α modulators on developmental ethanol-induced neurodegeneration and neuroinflammation.

Ethanol exposure in neonatal mice induces acute neurodegeneration followed by long-lasting glial activation and GABAergic cell deficits along with behavioral abnormalities, providing a third trimester model of fetal alcohol spectrum disorders (FASD). Retinoic acid (RA), the active form of vitamin A, regulates transcription of RA-responsive genes and plays essential roles in the development of embryos and their CNS. Ethanol has been shown to disturb RA metabolism and signaling in the developing brain, which may be a cause of ethanol toxicity leading to FASD. Using an agonist and an antagonist specific to RA receptor α (RARα), we studied how RA/RARα signaling affects acute and long-lasting neurodegeneration and activation of phagocytic cells and astrocytes caused by ethanol administered to neonatal mice. We found that an RARα antagonist (BT382) administered 30 min before ethanol injection into postnatal day 7 (P7) mice partially blocked acute neurodegeneration as well as elevation of CD68-positive phagocytic cells in the same brain area. While an RARα agonist (BT75) did not affect acute neurodegeneration, BT75 given either before or after ethanol administration ameliorated long-lasting astrocyte activation and GABAergic cell deficits in certain brain regions. Our studies using Nkx2.1-Cre;Ai9 mice, in which major GABAergic neurons and their progenitors in the cortex and the hippocampus are labeled with constitutively expressed tdTomato fluorescent protein, indicate that the long-lasting GABAergic cell deficits are mainly caused by P7 ethanol-induced initial neurodegeneration. However, the partial reduction of prolonged GABAergic cell deficits and glial activation by post-ethanol BT75 treatment suggests that, in addition to the initial cell death, there may be delayed cell death or disturbed development of GABAergic cells, which is partially rescued by BT75. Since RARα agonists including BT75 have been shown to exert anti-inflammatory effects, BT75 may rescue GABAergic cell deficits by reducing glial activation/neuroinflammation.

Development of a New Methodology for Dearomative Borylation of Coumarins and Chromenes and Its Applications to Synthesize Boron-Containing Retinoids.

Dearomative borylation of coumarins and chromenes via conjugate addition represents a relatively unexplored and challenging task. To address this issue, herein, we report a new and general copper (I) catalyzed dearomative borylation process to synthesize boron-containing oxacycles. In this report, the borylation of coumarins, chromones, and chromenes comprising functional groups, such as esters, nitriles, carbonyls, and amides, has been achieved. In addition, the method generates different classes of potential boron-based retinoids, including the ones with oxadiazole and anthocyanin motifs. The borylated oxacycles can serve as suitable intermediates to generate a library of compounds.

Anti-inflammatory Action of BT75, a Novel RARα Agonist, in Cultured Microglia and in an Experimental Mouse Model of Alzheimer's Disease.

BT75, a boron-containing retinoid, is a novel retinoic acid receptor (RAR)α agonist synthesized by our group. Previous studies indicated that activation of retinoic acid (RA) signaling may attenuate progression of Alzheimer's disease (AD). Presently, we aimed to examine the anti-inflammatory effect of BT75 and explore the possible mechanism using cultured cells and an AD mouse model. Pretreatment with BT75 (1-25 µM) suppressed the release of nitric oxide (NO) and IL-1ß in the culture medium of mouse microglial SIM-A9 cells activated by LPS. BMS195614, an RARα antagonist, partially blocked the inhibition of NO production by BT75. Moreover, BT75 attenuated phospho-Akt and phospho-NF-κB p65 expression augmented by LPS. In addition, BT75 elevated arginase 1, IL-10, and CD206, and inhibited inducible nitric oxide synthase (iNOS) and IL-6 formation in LPS-treated SIM-A9 cells, suggesting the promotion of M1-M2 microglial phenotypic polarization. C57BL/6 mice were injected intracerebroventricularly (icv) with streptozotocin (STZ) (3 mg/kg) to provide an AD-like mouse model. BT75 (5 mg/kg) or the vehicle was intraperitoneally (ip) injected to icv-STZ mice once a day for 3 weeks. Immunohistochemical analyses indicated that GFAP-positive cells and rod or amoeboid-like Iba1-positive cells, which increased in the hippocampal fimbria of icv-STZ mice, were reduced by BT75 treatment. Western blot results showed that BT75 decreased levels of neuronal nitric oxide synthase (nNOS), GFAP, and phosphorylated Tau, and increased levels of synaptophysin in the hippocampus of icv-STZ mice. BT75 may attenuate neuroinflammation by affecting the Akt/NF-κB pathway and microglial M1-M2 polarization in LPS-stimulated SIM-A9 cells. BT75 also reduced AD-like pathology including glial activation in the icv-STZ mice. Thus, BT75 may be a promising anti-inflammatory and neuroprotective agent worthy of further AD studies.