Infective Endocarditis Presenting as Intracranial Hemorrhage: A Case Report.

We describe a 31-year-old woman who presented with acute right-sided weakness and was found to have a subarachnoid hemorrhage in the left Sylvian fissure and an ipsilateral frontal intraparenchymal hemorrhage. CT angiography revealed an occlusion of the left middle cerebral artery's M1 segment and a saccular aneurysm at its bifurcation. A cerebral angiogram confirmed these findings, and the patient subsequently underwent microsurgical aneurysm resection, which revealed a partially thrombosed pseudoaneurysm. Further stroke workup identified mitral valve vegetation, confirming the diagnosis of infective endocarditis.

Carotidynia - An Unexplored Entity in Otolaryngology Practice: Three Case Reports & Review of Literature.

Carotidynia is transient perivascular inflammation of the carotid artery. It is a rare condition of head and neck associated with atypical neck pain, often unilateral. Patients with carotidynia often presents with atypical symptoms that makes the diagnosis of this rare entity difficult. In this article, we report a case series of 3 patients that presents with variable symptoms along with different investigative modalities and treatment approaches. Due to rare entity, this condition is often misdiagnosed or necessitates several visits to various specialties before a diagnosis is reached. Thorough clinical examination along with radiology is must to reach to a diagnosis. Patient should be counselled regarding the benign nature of the disease that can be easily controlled by low dose steroids.

IL-33 prevents age-related bone loss and memory impairment by suppression of Th17 response: evidence in a d-galactose-induced aging mouse model.

Cytokines are the primary mediators of age-related disorders. The IL-17/IL-10 axis plays a crucial role in bone destruction and neuro-inflammation. Additionally, a new Th2 cytokine-IL-33-has gained attention for its potential implications in aging-associated conditions. However, the involvement of IL-33 in aging-mediated bone loss and memory impairment remains unclear and needs further investigation. This study reveals the impact of IL-33 on various aspects of the immune system, bone health, and neural functions. To induce senescence, we used d-galactose for its convenience and fewer side effects. The experimental design involved treating 20-week-old C57BL/6J mice with d-galactose subcutaneously for 10 weeks to induce aging-like effects. Thereafter, IL-33 recombinant protein was administered intraperitoneally for 15 days to evaluate its impact on various immune, skeletal, and neural parameters. The results demonstrated that d-galactose-induced aging led to bone loss and compromised osteogenic parameters, accompanied by increased oxidative stress and neurodegeneration in specific brain regions. Behavioral activities were also affected. However, supplementation with IL-33 mitigated these effects, elevating osteogenic parameters and reducing senescence markers in osteoblast cells in an aging mouse model and exerted neuroprotective potential. Notably d-galactose-induced aging was characterized by high bone turnover, reflected by altered serum levels of CTX, PTH, beta-galactosidase, and P1NP. IL-33 treatment attenuated these effects, suggesting its role in regulating bone metabolism. Furthermore, d-galactose-induced aging was associated with increased differentiation of Th17 cells and upregulation of associated markers, such as STAT-3 and ROR-γt, while downregulating Foxp3, which antagonizes Th17 cell differentiation. IL-33 treatment countered these effects by suppressing Th17 cell differentiation and promoting IL-10-producing T-regulatory cells. Overall, these findings provide insights into the potential therapeutic implications of IL-33 in addressing aging-induced bone loss and memory impairment.

Unraveling the molecular basis for effective regulation of integrin α5ß1 for enhanced therapeutic interventions.

Cell attachment to the extracellular matrix significantly impacts the integrity of tissues and human health. The integrin α5ß1 is a heterodimer of α5 and ß1 subunits and has been identified as a crucial modulator in several human carcinomas. Integrin α5ß1 significantly regulates cell proliferation, angiogenesis, inflammation, tumor metastasis, and invasion. This regulatory role of integrin α5ß1 in tumor metastasis makes it an appealing target for cancer therapy. The majority of the drugs targeting integrin α5ß1 are limited only to clinical trials. In our study, we have performed 94287 compounds screening to determine potential drugs against α5ß1 integrin. We have used ATN-161 as a reference and employed combined bioinformatic methodologies, including molecular modelling, virtual screening, MM-GBSA, cell-line cytotoxicity prediction, ADMET, Density Functional Theory (DFT), Non-covalent Interactions (NCI) and molecular simulation, to identify putative integrin α5ß1 inhibitors. We found Taxifolin, PD133053, and Acebutolol that possess inhibitory activity against α5ß1 integrin and could act as effective drug for the cancer treatment. Taxifolin, PD133053, and Acebutolol exhibited excellent binding to the druggable pocket of integrin α5ß1, and also maintained a unique binding mechanism with extra hydrophobic contacts at molecular level. Overall, our study gives new pharmacological candidates that may act as a potential drug against integrin α5ß1.

A Diagnostically Challenging Case of Recurrent Encephalitis With Impending Herniation.

Encephalitis is characterized by inflammation of the brain parenchyma with typical presenting symptoms of altered mental status and seizures. However, diagnostic workup is complex given the multitude of possible etiologies for encephalitis. Further, recurrence of encephalitis is rare, and understanding its risk factors, mechanisms, prognosis, and optimal treatment remains incomplete. Here, we present the case of a 69-year-old woman admitted to our hospital with altered mental status who was diagnosed with encephalitis based on clinical and imaging findings. This case highlights the diagnostic approaches required to obtain the final diagnosis and the treatment plan that resulted in the patient's eventual return to baseline and functional independence.

Mapping Patient Pathways in Tuberculosis Care: Insights From Gujarat and Jharkhand States of India.

BACKGROUND: Tuberculosis (TB) continues to pose a significant public health challenge globally. Despite efforts to meet targets set by the End-TB Strategy, progress has been slow. Health-seeking practices that decide approaches to various sectors of healthcare providers result in inappropriate diagnosis and lack of awareness regarding available standard treatment, indicating inaccuracy in estimated incidences and underreporting. OBJECTIVE: This study was designed to map the patient pathways for Persons with Tuberculosis (PwTB) from their initial point of contact through to diagnosis and treatment. It aimed to identify the socio-demographic characteristics and profiles of PwTB, as well as their choice of healthcare facilities, that influenced care-seeking behavior throughout the TB care cascade. METHODS: A cross-sectional study was conducted from January to July 2022 in Jharkhand and Gujarat, India. Data were collected from 997 PwTB using a pre-designed structured questionnaire, covering socio-demographic profiles, TB profile of PwTB, and care-seeking behavior. The study analyzed the number and types of facilities visited, categorized the data, and used chi-square and binary logistic regression tests to identify significant associations. RESULTS: In a study of 965 TB patients, 58.8% were male, and 61.3% were aged 18-40. Patients visited an average of two healthcare facilities, with significant associations found between age, occupation, comorbidity status, and facility switching (p < 0.005). Public health facilities were the primary point of care, with 91.4% using them for first consultations and 80.6% for treatment. Regression analysis highlighted significant predictors of care-seeking behavior, underscoring the need to enhance public healthcare infrastructure. CONCLUSION: Understanding patient pathways and the factors influencing care-seeking behavior is crucial for improving TB management. Strengthening public healthcare infrastructure and enhancing coordination between public and private sectors can reduce transitions and ensure timely and appropriate care.

Integrins α5ß1 and αvß3 Differentially Participate in the Recruitment and Reprogramming of Tumor-associated Macrophages in the In Vitro and In Vivo Models of Breast Tumor.

Tumor-associated macrophages (TAMs) drive the protumorigenic responses and facilitate tumor progression via matrix remodeling, angiogenesis, and immunosuppression by interacting with extracellular matrix proteins via integrins. However, the expression dynamics of integrin and its correlation with TAM functional programming in the tumors remain unexplored. In this study, we examined surface integrins' role in TAM recruitment and phenotypic programming in a 4T1-induced murine breast tumor model. Our findings show that integrin α5ß1 is upregulated in CD11b+Ly6Chi monocytes in the bone marrow and blood by day 10 after tumor induction. Subsequent analysis revealed elevated integrin α5ß1 expression on tumor-infiltrating monocytes (Ly6ChiMHC class II [MHCII]low) and M1 TAMs (F4/80+Ly6ClowMHCIIhi), whereas integrin αvß3 was predominantly expressed on M2 TAMs (F4/80+Ly6ClowMHCIIlow), correlating with higher CD206 and MERTK expression. Gene profiling of cells sorted from murine tumors showed that CD11b+Ly6G-F4/80+α5+ TAMs had elevated inflammatory genes (IL-6, TNF-α, and STAT1/2), whereas CD11b+Ly6G-F4/80+αv+ TAMs exhibited a protumorigenic phenotype (IL-10, Arg1, TGF-ß, and STAT3/6). In vitro studies demonstrated that blocking integrin α5 and αv during macrophage differentiation from human peripheral blood monocytes reduced cell spreading and expression of CD206 and CD163 in the presence of specific matrix proteins, fibronectin, and vitronectin. Furthermore, RNA sequencing data analysis (GEO dataset: GSE195857) from bone marrow-derived monocytes and TAMs in 4T1 mammary tumors revealed differential integrin α5 and αv expression and their association with FAK and SRC kinase. In line with this, FAK inhibition during TAM polarization reduced SRC, STAT1, and STAT6 phosphorylation. In conclusion, these findings underscore the crucial role of integrins in TAM recruitment, polarization, and reprogramming in tumors.

Uncovering the Potential ofO-Prenylated 3-aryl-benzopyran Derivatives as Osteogenic and Cancer Cell Growth Inhibitory Agents.

Naturally, O-prenylation of 3-aryl-benzopyrans enhances the biological activities of these compounds. In this study, substituted O-prenylated 3-aryl-benzopyrans (21a-c, 22a-c, 23a-c, 24a-c 25a-c, 27 and 28) were synthesized and evaluated for osteogenic and cancer cell growth inhibitory potentials using cell-based in-vitro models. Amongst the target compounds, 21a, 22b, 23c, and 24c showed good osteogenic activity at 1 pM concentration, whereas 26 and 27 showed osteogenic activity at 100pM and 10nM, respectively. Compounds 21a, 22b, and 23c showed good cancer cell growth inhibitory activity against breast cancer cells (MCF-7 and MBA-231). Amongst active compounds, 27 presented the best anticancer activity against MDAMB-231 cells with selectivity towards non-cancerous cells [IC50 3.76 µM with SI 13.3]. The in-silico study of compounds showed their structural complementarities with the LBD of estrogen receptors and compliance with dragability parameters.

Reversible Bilateral Vision Loss: An Unusual Presentation of Wernicke-Korsakoff Syndrome.

Neuro-ophthalmic manifestations of Wernicke encephalopathy (WE) are uncommon and vary from nystagmus, oculomotor palsies, anisocoria, and optic disc edema to vision loss. We describe a case of a 53-year-old woman presenting with subacute bilateral painless vision decline, lower-extremities weakness with impaired ambulation, headache, and abdominal pain. Neurological examination was pertinent for confabulation, bilateral decreased visual acuity with an absent blink to threat, absent afferent pupillary defect and fundus abnormalities, and significant allodynia in bilateral lower extremities. Besides elevated inflammatory marker with an erythrocyte sedimentation rate (ESR) of 130 mm/hr, her infectious, autoimmune, paraneoplastic, and neuromyelitis optica work-up was overall unremarkable. Brain MRI showed abnormal fluid-attenuated inversion recovery (FLAIR) signaling in bilateral mammillary bodies and around periaqueductal gray matter concerning WE. Due to concerns of Wernicke-Korsakoff syndrome (WKS), parenteral high-dose thiamine was initiated with significant clinical improvement. The patient was also later found to have a positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody, which was deemed false positive given the atypical phenotype and symptomatic improvement with thiamine supplementation. This case encourages the consideration of vision loss as a manifestation of WKS, especially in patients who have risk factors. Testing serum levels of thiamine is strongly encouraged; however, initiating empiric treatment is advocated for high clinical suspicion due to its reversible nature and minimal risk for side effects.

A Comparative Evaluation of Herbal Extracts and Triple Antibiotic Paste as Intracanal Medicament against Enterococcus faecalis: A Microbiological Study.

Purpose: The purpose of the study is to compare and evaluate the efficacy of herbal extracts over modified triple antibiotic paste (MTAP) as intracanal medicaments against Enterococcus faecalis (E. faecalis). Ginger, turmeric, and nutmeg extract were checked for antibacterial activity by agar disk diffusion method at 100, 50, 25, and 12.5% concentration. Combination groups were prepared, and the combination group showing the best zone of inhibition was further evaluated. Materials and methods: A total of 103 samples were taken and divided into five groups: group I-MTAP, group II-ginger, group III-turmeric, group IV-nutmeg, and group V-saline. Based on different concentrations, the groups were again subdivided into subgroups at 100, 50, 25, and 12.5%. Combination groups of ginger + nutmeg, ginger + turmeric, and turmeric + nutmeg were made and evaluated. The combination group showing the best zone of inhibition was again divided into 100, 50, 25, and 12.5% and further evaluated. Results: Modified triple antibiotic was effective in the elimination of E. faecalis. Herbal extracts showed a reduction in the number of E. faecalis. Nutmeg showed a reduction in E. faecalis, followed by ginger, followed by turmeric. Conclusion: This study shows that the combination of ginger + nutmeg at 12.5% concentration (35 mm) showed the highest zone of inhibition among all the herbal combinations, which is almost equal to that of MTAP. How to cite this article: Golla S, Gambhir N, Gupta N, et al. A Comparative Evaluation of Herbal Extracts and Triple Antibiotic Paste as Intracanal Medicament against Enterococcus faecalis: A Microbiological Study. Int J Clin Pediatr Dent 2024;17(3):285-290.

Identification of a Promising Novel Genetic Source for Rice Root-Knot Nematode Resistance through Markers Associated with Trait-Specific Quantitative Trait Loci.

Direct-seeded rice (DSR) is gaining popularity among farmers due to its environmentally safe and resource-efficient production system. However, managing the rice root-knot nematode (RRKN), Meloidogyne graminicola, remains a major challenge in DSR cultivation. Developing genetic resistance is a pragmatic and effective approach compared to using hazardous pesticides. Pusa Basmati 1121 (PB1121) is the most popular Basmati rice variety, but it is highly susceptible to RRKN. In contrast, Phule Radha (PR) has shown highly resistant reaction to RRKN, as reported in our earlier study. We generated an F2:3 population from the cross of PB1121/PR and evaluated it for RRKN resistance-related traits under artificial inoculation conditions. The distribution pattern of traits in the F2:3 population indicated that resistance may be governed by a few major-effect genes and many minor-effect genes. The molecular markers reported to be associated with QTLs governing RRKN resistance traits were used to test in the current population. Although the simple linear regression identified significant associations between the markers and RRKN resistance-associated traits, these associations were spurious as the LOD score was below the threshold limit. This indicates that PR possesses novel genomic regions for resistance to RRKN as it does not possess any of the earlier reported QTLs.

Transverse Myelitis: A Case-Based Discussion of Infectious Etiologies.

Transverse myelitis (TM) is a frequently encountered inpatient neurological condition, usually with a broad differential of etiologies narrowed down by detailed history, temporal profile of symptom evolution, and pertinent diagnostic studies. We report a rare case of a 39-year-old man who presented with subacute onset of headaches and confusion, and three days later developed quadriplegia and areflexia. He was diagnosed with acute longitudinally extensive transverse myelitis (LETM) related to Epstein-Barr virus (EBV) superimposed on an initial presentation of streptococcal meningitis. As both etiologies are under-reported, we compare our case to the few similar cases in the literature to guide discussion of the clinical and radiologic findings of parainfectious TM related to EBV and streptococcal meningitis. Readers will have the challenge of attributing our patient's myelitis to one of these parainfectious sources and are encouraged to evaluate for rare infectious etiologies in acute settings.

Locked-In Syndrome: A Rare Manifestation of Neuropsychiatric Lupus.

Neuropsychiatric systemic lupus erythematosus (SLE) is a rare condition that has a multitude of mechanisms resulting in the emergence of variable clinical presentations. We describe a peculiar case of a 33-year-old female with a history of SLE presented with two weeks of fever, headache, and vomiting. On admission, she became obtunded and was emergently intubated. Initial lumbar puncture revealed pleocytosis (46% neutrophils, 320 corrected nucleated cells/µL), elevated protein (244 mg/dL; normal, 15-40 mg/dL), normal glucose (63 mg/dL), and negative cultures. Empiric acyclovir, ampicillin, ceftriaxone, and vancomycin were initiated without clinical improvement. Neurological examination was notable for limited ability to follow commands, vertical nystagmus, horizontal gaze palsy, diffuse hyperreflexia, and quadriparesis. Electroencephalogram (EEG) was consistent with diffuse encephalopathy. Brain magnetic resonance imaging demonstrated restricted diffusion and contrast enhancement in the posterior and central pons with edema. A cerebral angiogram showed no signs of vasculitis. Treatment with intravenous (IV) methylprednisolone 1 g and IV immunoglobulin 2 g/kg was initiated for five days. Despite these interventions, no discernible clinical improvement was observed, prompting the commencement of 500 mg/m2 cyclophosphamide and daily maintenance of IV methylprednisolone at 2 mg/kg. A repeat MRI three weeks later revealed a marked reduction in the size of the lesion involving the pons. The patient also improved clinically over the month with successful extubation, complete return in mental capabilities, and the ability to ambulate short distances with assistance.

Modulating temperature for Cu2ZnSnS4 (CZTS) synthesis via hot injection method and studying the photocatalytic efficiencies for the degradation of rhodamine 6G and methylene blue pollutants.

Cu2ZnSnS4 (CZTS) was synthesized following hot injection method and the process was optimized by varying temperature conditions. Four samples at different temperatures viz., 200, 250, 300 and 350 °C were prepared and analyzed using different characterization techniques. Based on the correlation between XRD, Raman and XPS, we conclude that the formation of ZnS and SnS2 occurs at 350 °C but at 200 °C there is no breakdown of the complex as per XRD. According to Raman and XPS analysis, as the temperature rises, the bonds between the metals become weaker, which is visibly seen in Raman and XPS due to the minor peaks of copper sulfide. Scanning electron microscopic analysis confirmed nanometric particles which increase in size with temperature. The photocatalytic evaluation showed that CZTS synthesized at 200 °C performed efficiently in the removal of the two colorants, methylene blue and Rhodamine 6G, achieving 92.80% and 90.65%, respectively. The photocatalytic degradation efficiencies decreased at higher temperatures due to bigger sized CZTS particles as confirmed by SEM results. Computational simulations confirm that CZTS has a highly negative energy -25,764 Ry, confirming its structural stability and higher covalent than ionic character.

When Blood Cell Counts Matter: Hypereosinophilic Syndrome as a Rare Cause of Ischemic Strokes.

Hypereosinophilic syndrome (HES) is a rare condition characterized by elevated eosinophil counts (>1.5 x 109 on two consecutive measurements), which are of myeloid clonal in origin or are driven by excess cytokines. One subtype of HES exhibits the Fip1-like 1-platelet-derived growth factor receptor alpha (FIP1L1-PDGFRA) fusion gene, a gain-of-function mutation resulting in a hyperactive tyrosine kinase. HES, especially the FIP1L1-PDGFRA variant, exhibits an excellent response to chemotherapy with imatinib. In this report, we present a 38-year-old patient with no contributory past medical history who experienced sudden-onset fatigue, ataxia, visual changes, and headaches. He was found to have multiple small acute infarcts in his cerebrum and cerebellum. A stroke work-up, including transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), and computed tomography angiography (CTA), did not yield insight into the origin of his infarcts. On CBC, he was consistently hypereosinophilic, and a bone marrow biopsy revealed hypercellularity and the FIP1L1-PDGFRA fusion gene, confirming the diagnosis of HES. The patient was treated first with methylprednisolone and then imatinib with excellent response. It appears that, in our patient, strokes were not of a thromboembolic nature but rather due to hypercoagulability. In this report, we advocate for considering HES and emphasize the importance of revisiting basic laboratory studies such as a CBC if the standard stroke workup fails to elucidate the mechanism behind ischemic strokes with an embolic pattern.

Forward genetics combined with unsupervised classifications identified zebrafish mutants affecting biliary system formation.

Impaired formation of the biliary network can lead to congenital cholestatic liver diseases; however, the genes responsible for proper biliary system formation and maintenance have not been fully identified. Combining computational network structure analysis algorithms with a zebrafish forward genetic screen, we identified 24 new zebrafish mutants that display impaired intrahepatic biliary network formation. Complementation tests suggested these 24 mutations affect 24 different genes. We applied unsupervised clustering algorithms to unbiasedly classify the recovered mutants into three classes. Further computational analysis revealed that each of the recovered mutations in these three classes has a unique phenotype on node-subtype composition and distribution within the intrahepatic biliary network. In addition, we found most of the recovered mutations are viable. In those mutant fish, which are already good animal models to study chronic cholestatic liver diseases, the biliary network phenotypes persist into adulthood. Altogether, this study provides unique genetic and computational toolsets that advance our understanding of the molecular pathways leading to biliary system malformation and cholestatic liver diseases.

Low-latency gravitational wave alert products and their performance at the time of the fourth LIGO-Virgo-KAGRA observing run.

Multimessenger searches for binary neutron star (BNS) and neutron star-black hole (NSBH) mergers are currently one of the most exciting areas of astronomy. The search for joint electromagnetic and neutrino counterparts to gravitational wave (GW)s has resumed with ALIGO's, AdVirgo's and KAGRA's fourth observing run (O4). To support this effort, public semiautomated data products are sent in near real-time and include localization and source properties to guide complementary observations. In preparation for O4, we have conducted a study using a simulated population of compact binaries and a mock data challenge (MDC) in the form of a real-time replay to optimize and profile the software infrastructure and scientific deliverables. End-toend performance was tested, including data ingestion, running online search pipelines, performing annotations, and issuing alerts to the astrophysics community. We present an overview of the low-latency infrastructure and the performance of the data products that are now being released during O4 based on the MDC. We report the expected median latency for the preliminary alert of full bandwidth searches (29.5 s) and show consistency and accuracy of released data products using the MDC. We report the expected median latency for triggers from early warning searches (-3.1 s), which are new in O4 and target neutron star mergers during inspiral phase. This paper provides a performance overview for LIGO-Virgo-KAGRA (LVK) low-latency alert infrastructure and data products using theMDCand serves as a useful reference for the interpretation of O4 detections.

iNOS regulates hematopoietic stem and progenitor cells via mitochondrial signaling and is critical for bone marrow regeneration.

Hematopoietic stem cells (HSCs) replenish blood cells under steady state and on demand, that exhibit therapeutic potential for Bone marrow failures and leukemia. Redox signaling plays key role in immune cells and hematopoiesis. However, the role of reactive nitrogen species in hematopoiesis remains unclear and requires further investigation. We investigated the significance of inducible nitric oxide synthase/nitric oxide (iNOS/NO) signaling in hematopoietic stem and progenitor cells (HSPCs) and hematopoiesis under steady-state and stress conditions. HSCs contain low levels of NO and iNOS under normal conditions, but these increase upon bone marrow stress. iNOS-deficient mice showed subtle changes in peripheral blood cells but significant alterations in HSPCs, including increased HSCs and multipotent progenitors. Surprisingly, iNOS-deficient mice displayed heightened susceptibility and delayed recovery of blood progeny following 5-Fluorouracil (5-FU) induced hematopoietic stress. Loss of quiescence and increased mitochondrial stress, indicated by elevated MitoSOX and MMPhi HSCs, were observed in iNOS-deficient mice. Furthermore, pharmacological approaches to mitigate mitochondrial stress rescued 5-FU-induced HSC death. Conversely, iNOS-NO signaling was required for demand-driven mitochondrial activity and proliferation during hematopoietic recovery, as iNOS-deficient mice and NO signaling inhibitors exhibit reduced mitochondrial activity. In conclusion, our study challenges the conventional view of iNOS-derived NO as a cytotoxic molecule and highlights its intriguing role in HSPCs. Together, our findings provide insights into the crucial role of the iNOS-NO-mitochondrial axis in regulating HSPCs and hematopoiesis.

Litsea glutinosa extract promotes fracture healing and prevents bone loss via BMP2/SMAD1 signaling.

Estrogen deficiency is one of the main causes for postmenopausal osteoporosis. Current osteoporotic therapies are of high cost and associated with serious side effects. So there is an urgent need for cost-effective anti-osteoporotic agents. Anti-osteoporotic activity of Litsea glutinosa extract (LGE) is less explored. Moreover, its role in fracture healing and mechanism of action is still unknown. In the present study we explore the osteoprotective potential of LGE in osteoblast cells and fractured and ovariectomized (Ovx) mice models. Alkaline phosphatase (ALP), MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and mineralization assays revealed that LGE treatment increased osteoblast cell differentiation, viability and mineralization. LGE treatment at 0.01 µg increased the expression of BMP2, PSMAD, RUNX2 and type 1 col. LGE also mitigated RANKL-induced osteoclastogenesis. Next, drill hole injury Balb/C mice model was treated with LGE for 12 days. Micro-CT analysis and Calcein labeling at the fracture site showed that LGE (20 mg/kg) enhanced new bone formation and bone regeneration, also increased expression of BMP2/SMAD1 signaling genes at fracture site. Ovx mice were treated with LGE for 1 month. µCT analysis indicated that the treatment of LGE at 20 mg/kg dose prevented the alteration in bone microarchitecture and maintained bone mineral density and bone mineral content. Treatment also increased bone strength and restored the bone turnover markers. Furthermore, in bone samples, LGE increased osteogenesis by enhancing the expression of BMP2/SMAD1 signaling components and decreased osteoclast number and surface. We conclude that LGE promotes osteogenesis via modulating the BMP2/SMAD1 signaling pathway. The study advocates the therapeutic potential of LGE in osteoporosis treatment.

Design, synthesis and biological evaluation of novel pyrimidine derivatives as bone anabolic agents promoting osteogenesis via the BMP2/SMAD1 signaling pathway.

Anti-resorptive inhibitors such as bisphosphonates are widely used but they have limited efficacy and serious side effects. Though subcutaneous injection of teriparatide [PTH (1-34)] is an effective anabolic therapy, long-term repeated subcutaneous administration is not recommended. Henceforth, orally bio-available small-molecule-based novel therapeutics are unmet medical needs to improve the treatment. In this study, we designed, synthesized, and carried out a biological evaluation of 31 pyrimidine derivatives as potent bone anabolic agents. A series of in vitro experiments confirmed N-(5-bromo-4-(4-bromophenyl)-6-(2,4,5-trimethoxyphenyl)pyrimidin-2-yl)hexanamide (18a) as the most efficacious anabolic agent at 1 pM. It promoted osteogenesis by upregulating the expression of osteogenic genes (RUNX2 and type 1 col) via activation of the BMP2/SMAD1 signaling pathway. In vitro osteogenic potential was further validated using an in vivo fracture defect model where compound 18a promoted the bone formation rate at 5 mg kg-1. We also established the structure-activity relationship and pharmacokinetic studies of 18a.