RESUMEN

Oral Topiramate therapy is associated with systemic adverse effects including paresthesia,abdominal pain, and fluctuations in plasma levels. The purpose of this research was to develop an intranasal in situ gel based system comprising Topiramate polymeric nanoparticles and evaluate its potential both in vitro and in vivo. Poly (lactic-co-glycolic acid) (PLGA)nanoparticles prepared by nanoprecipitation method were added into the in situ gelling system of Poloxamer 407 and HPMC K4M. Selected formulation (TG5) was evaluated for physicochemical properties, nasal permeation and in vivo pharmacokinetics in rats. PLGAnanoparticles (O1) exhibited low particle size (~ 144.4 nm), good polydispersity index (0.202), negative zeta potential (-12.7 mV), and adequate entrapment efficiency (64.7%). Developed in situ gel showed ideal pH (6.5), good gelling time (35 s), gelling temperature(37℃), suitable viscosity (1335 cP)and drug content of 96.2%. In vitro drug release conformedto Higuchi release kinetics, exhibiting a biphasic pattern of initial burst release and sustained release for 24 h. Oral administration of the drug to Sprague-Dawley rats (G3) showed higher plasma Cmax(504 ng/ml, p < 0.0001) when compared to nasal delivery of in situ gel (G4) or solution (G5). Additionally, AUC0-α of G3 (8786.82 ng/ml*h) was considerably higher than othergroups. Brain uptake data indicates a higher drug level with G4 (112.47 ng /ml) at 12 h when compared to G3. Histopathological examination of groups; G1 (intranasal saline), G2(intranasal placebo), G3, G4, and G5 did not show any lesions of pathological significance. Overall, the experimental results observed were promising and substantiated the potential of developed in situ gel for intranasal delivery.

Asunto(s)

Administración Intranasal , Encéfalo , Geles , Nanopartículas , Mucosa Nasal , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Ratas Sprague-Dawley , Topiramato , Animales , Topiramato/administración & dosificación , Topiramato/farmacocinética , Nanopartículas/química , Ratas , Administración Intranasal/métodos , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Mucosa Nasal/metabolismo , Mucosa Nasal/efectos de los fármacos , Masculino , Tamaño de la Partícula , Fructosa/administración & dosificación , Fructosa/farmacocinética , Fructosa/química , Portadores de Fármacos/química , Liberación de Fármacos , Sistemas de Liberación de Medicamentos/métodos , Ácido Láctico/química , Ácido Láctico/administración & dosificación , Ácido Poliglicólico/química , Administración Oral

RESUMEN

Coronaviruses are highly transmissible respiratory viruses that cause symptoms ranging from mild congestion to severe respiratory distress. The recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has underscored the need for new antivirals with broad-acting mechanisms to combat increasing emergence of new variants. Currently, there are only a few antivirals approved for treatment of SARS-CoV-2. Previously, the rocaglate natural product silvestrol and synthetic rocaglates such as CR-1-31b were shown to have antiviral effects by inhibiting eukaryotic translation initiation factor 4A1 (eIF4A) function and virus protein synthesis. In this study, we evaluated amidino-rocaglates (ADRs), a class of synthetic rocaglates with the most potent eIF4A-inhibitory activity to-date, for inhibition of SARS-CoV-2 infection. This class of compounds showed low nanomolar potency against multiple SARS-CoV-2 variants and in multiple cell types, including human lung-derived cells, with strong inhibition of virus over host protein synthesis and low cytotoxicity. The most potent ADRs were also shown to be active against two highly pathogenic and distantly related coronaviruses, SARS-CoV and MERS-CoV. Mechanistically, cells with mutations of eIF4A1, which are known to reduce rocaglate interaction displayed reduced ADR-associated loss of cellular function, consistent with targeting of protein synthesis. Overall, ADRs and derivatives may offer new potential treatments for SARS-CoV-2 with the goal of developing a broad-acting anti-coronavirus agent.

Asunto(s)

Antivirales , Biosíntesis de Proteínas , SARS-CoV-2 , Replicación Viral , SARS-CoV-2/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Antivirales/farmacología , Antivirales/síntesis química , Antivirales/química , Humanos , Chlorocebus aethiops , Animales , Biosíntesis de Proteínas/efectos de los fármacos , Células Vero , Tratamiento Farmacológico de COVID-19 , Benzofuranos/farmacología , Benzofuranos/síntesis química , Benzofuranos/química , COVID-19/virología , Proteínas Virales/antagonistas & inhibidores , Proteínas Virales/metabolismo , Proteínas Virales/genética , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Factor 4A Eucariótico de Iniciación/metabolismo

RESUMEN

BACKGROUND: Empagliflozin (EMPA) is an SGLT2 inhibitor, a new class of anti-diabetic medication, indicated for treating type-2 diabetes. Its low permeability, poor solubility and bioavailability limits its use in management of diabetes. The study was aimed to formulate EMPA loaded polymeric micelles (PMs) to overcome these obstacles in oral absorption. METHODOLOGY: In silico studies-molecular docking, molecular dynamic simulation (MDS), and quantum chemical calculation were employed to study the interaction of EMPA with different polymers. EMPA loaded TPGS polymeric micelles (EMPA-TPGS-PMs) were formulated by direct dissolution method and characterized in terms of surface morphology, entrapment, particle size, in vitro drug release, and in vitro cytotoxicity (HEK293 cells). In vivo pharmacokinetic and pharmacodynamic studies were also performed. RESULTS: The results suggested a good interaction between TPGS and EMPA with lowest binding energy compared to other polymers. Further MDS results and DFT calculations validated the stable binding of the complex hence TPGS was selected for further wet lab experiments. The EMPA-TPGS complex displayed lower value of Total energy (T.E.) than its individual components, indicating the overall stability of the complex while, the energy band gap (∆E) value lied between the two individual molecules, signifying the better electron transfer between HOMO and LUMO of the complex. Based on the solubility, entrapment and cytotoxicity studies, 5% TPGS was selected for formulating drug loaded micelles. EMPA-TPGS5-PMs presented a size of 9.008 ± 1.25 nm, Polydispersity index (PDI) of 0.254 ± 0.100, a controlled release behaviour upto 24 h. SEM and AFM images of the nanoformulation suggested spherical particles whereas, DSC, and PXRD studies confirmed the loss of crystallinity of EMPA. A 3.12-folds higher AUC and a greater reduction in blood glucose levels was exhibited by EMPA-TPGS5-PMs in comparison to EMPA-SUSP in mice model. CONCLUSION: EMPA-TPGS-PMs has exhibited better bio absorption and therapeutic effectiveness in diabetes treatment. This improved performance would open the possibility of dose reduction, reduced dosing frequency & dose-related side effects, improving pharmaco-economics and thereby improved overall compliance to the patient. However, this translation from bench to bedside would necessitate studies in higher animals and human volunteers.

RESUMEN

Ibrutinib, an antineoplastic agent tackling chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom's Macroglobulinemia, falls under the category of BCS class II drugs, characterized by a puzzling combination of low solubility and high permeability. Its oral bioavailability remains a perplexing challenge, merely reaching 2.9 % due to formidable first-pass metabolism hurdles. In a bid to surmount this obstacle, researchers embarked on a journey to develop ibrutinib-loaded NLCs (Nanostructured Lipid Carriers) using a methodology steeped in complexity: a Design of Experiments (DoE)-based hot melted ultrasonication approach. Despite a plethora of methods for analyzing ibrutinib in various matrices, the absence of a spectrofluorimetric method for assessing it in rat plasma added to the enigma. Thus emerged a spectrofluorimetric method, embodying principles of white analytical chemistry and analytical quality by design, employing a Placket-Burman design for initial method exploration and a central composite design for subsequent refinement. This method underwent rigorous validation in accordance with ICH guidelines, paving the way for its application in scrutinizing the in-vivo pharmacokinetics of ibrutinib-loaded NLCs, juxtaposed against commercially available formulations. Surprisingly, the optimized NLCs exhibited a striking 1.82-fold boost in oral bioavailability, shedding light on their potential efficacy. The environmental impact of this method was scrutinized using analytical greenness tools, affirming its eco-friendly attributes. In essence, the culmination of these efforts has not only propelled advancements in drug bioavailability but also heralded the dawn of a streamlined and environmentally conscious analytical paradigm.

Asunto(s)

Adenina , Lípidos , Piperidinas , Pirimidinas , Espectrometría de Fluorescencia , Animales , Adenina/análogos & derivados , Adenina/farmacocinética , Adenina/química , Adenina/sangre , Piperidinas/farmacocinética , Piperidinas/química , Piperidinas/sangre , Lípidos/química , Masculino , Espectrometría de Fluorescencia/métodos , Ratas , Pirimidinas/farmacocinética , Pirimidinas/química , Pirimidinas/sangre , Portadores de Fármacos/química , Nanoestructuras/química , Pirazoles/farmacocinética , Pirazoles/química , Pirazoles/sangre , Pirazoles/administración & dosificación , Reproducibilidad de los Resultados , Ratas Wistar

RESUMEN

The use of topical antimicrobials in wound healing presents challenges like risk of drug resistance and toxicity to local tissue. Simvastatin (SIM), a lipid-lowering agent which reduces the risk of cardiovascular events, is repurposed for its pleiotropic effect in wound healing. A bioactive bioadhesive polymer-based film forming spray (FFS) formulation of SIM was designed using chitosan, collagen, hyaluronic acid and optimised by employing the DoE approach. Optimised formulation demonstrated moderate viscosity (12.5 ± 0.3 cP), rapid film formation (231 ± 5.6 s), flexibility, tensile strength and sustained drug release (T80 - time for 80% drug release - 9.05 ± 0.7 h). Scanning electron microscopy (SEM) verified uniformly dispersed drug within the composite polymer matrix. SIM FFS demonstrated antimicrobial activity against gram positive and gram negative bacteria. In vivo excision wound model studies in mice affirmed the beneficent role of bioactive polymers and the efficacy of SIM FFS in wound contraction and closure, tissue remodelling and re-epithelization in comparison to standard antimicrobial preparation. Cytokines TNF- alpha, IL-6 were downregulated and IL-10 was upregulated. Biochemical markers; hydroxyproline, hexosamine and histopathology were consistent with wound contraction observed. This is an exploratory effort in repurposing SIM for wound healing in a novel dosage form, underscoring its potential as an alternative to conventional topical antimicrobials.

RESUMEN

Advancements in recombinant DNA technology have made proteins and peptides available for diagnostic and therapeutic applications, but their effectiveness when taken orally leads to poor patient compliance, requiring clinical administration. Among the alternative routes, transmucosal delivery has the advantage of being noninvasive and bypassing hepato-gastrointestinal clearance. Various mucosal routes-buccal, nasal, pulmonary, rectal, and vaginal-have been explored for delivering these macromolecules. Nanofibers, due to their unique properties like high surface-area-to-volume ratio, mechanical strength, and improved encapsulation efficiency, serve as promising carriers for proteins and peptides. These nanofibers can be tailored for quick dissolution, controlled release, enhanced encapsulation, targeted delivery, and improved bioavailability, offering superior pharmaceutical and pharmacokinetic performance compared to conventional methods. This leads to reduced dosages, fewer side effects, and enhanced patient compliance. Hence, nanofibers hold tremendous potential for protein/peptide delivery, especially through mucosal routes. This review focuses on the therapeutic application of proteins and peptides, challenges faced in their conventional delivery, techniques for fabricating different types of nanofibers and, various nanofiber-based dosage forms, and factors influencing nanofiber generation. Insights pertaining to the precise selection of materials used for fabricating nanofibers and regulatory aspects have been covered. Case studies wherein the use of specific protein/peptide-loaded nanofibers and delivered via oral/vaginal/nasal mucosa for diagnostic/therapeutic use and related preclinical and clinical studies conducted have been included in this review.

Asunto(s)

Sistemas de Liberación de Medicamentos , Nanofibras , Femenino , Humanos , Sistemas de Liberación de Medicamentos/métodos , Nanofibras/química , Proteínas , Péptidos , Preparaciones Farmacéuticas

RESUMEN

Hepatic metabolic stability is a crucial determinant of oral bioavailability and plasma concentrations of a compound, and its measurement is important in early drug discovery. Preliminary metabolic stability estimations are commonly performed in liver microsomal fractions. At the National Center for Advancing Translational Sciences, a single-point assay in rat liver microsomes (RLM) is employed for initial stability assessment (Tier I) and a multi-point detailed stability assay is employed as a Tier II assay for promising compounds. Although the in vitro and in vivo metabolic stability of compounds typically exhibit good correlation, conflicting results may arise in certain cases. While investigating one such instance, we serendipitously found vendor-related RLM differences in metabolic stability and metabolite formation, which had implications for in vitro and in vivo correlations. In this study, we highlight the importance of considering vendor differences in hepatic metabolic stability data and discuss strategies to avoid these pitfalls.

Asunto(s)

Descubrimiento de Drogas , Hígado , Ratas , Animales , Hígado/metabolismo , Descubrimiento de Drogas/métodos , Microsomas Hepáticos/metabolismo , Disponibilidad Biológica , Evaluación Preclínica de Medicamentos/métodos

RESUMEN

Transepithelial electrical resistance (TEER) is a widely used technique for quantifying the permeability of epithelial and endothelial cell layers. However, traditional methods of measuring TEER are limited to single timepoint measurements and can subject cells to an altered environment during the measurement. Here, we assessed the validity of TEER measurements by the ECIS TEER96 device, which is designed to take continuous TEER measurements of a cell culture system in a standard laboratory incubator. We found that the instrument accurately measures TEER across TEER values ranging from 10 to 2050 Ω*cm2 and is more accurate than the manual epithelial voltohmmeter electrode at high TEER values. Furthermore, the high-resolution measurements provided by the device allowed for a unique insight into the mechanisms and kinetics of cells in vitro. To demonstrate the continuous measurement capability of the device, we tracked the formation of an MDCKI cell monolayer until TEER plateaued. Furthermore, we treated Caco-2 monolayers with different concentrations of DMSO and the antimicrobial and surfactant compound benzethonium chloride to measure disruptions to barrier integrity. Treatment of both compounds resulted in concentration-dependent loss of barrier integrity. Our results suggest that the ECIS TEER96 device is a reliable and convenient option for measuring TEER in cell cultures and can provide valuable insights into the behavior of cells in vitro. This technology will be especially useful for increasing throughput of drug permeability assays, inflammation studies, and gaining better understanding of disease states in a cell culture system.

Asunto(s)

Técnicas de Cultivo de Célula , Células Endoteliales , Humanos , Células CACO-2 , Impedancia Eléctrica

RESUMEN

Efficiently circumventing the blood-brain barrier (BBB) poses a major hurdle in the development of drugs that target the central nervous system. Although there are several methods to determine BBB permeability of small molecules, the Parallel Artificial Membrane Permeability Assay (PAMPA) is one of the most common assays in drug discovery due to its robust and high-throughput nature. Drug discovery is a long and costly venture, thus, any advances to streamline this process are beneficial. In this study, ∼2,000 compounds from over 60 NCATS projects were screened in the PAMPA-BBB assay to develop a quantitative structure-activity relationship model to predict BBB permeability of small molecules. After analyzing both state-of-the-art and latest machine learning methods, we found that random forest based on RDKit descriptors as additional features provided the best training balanced accuracy (0.70 ± 0.015) and a message-passing variant of graph convolutional neural network that uses RDKit descriptors provided the highest balanced accuracy (0.72) on a prospective validation set. Finally, we correlated in vitro PAMPA-BBB data with in vivo brain permeation data in rodents to observe a categorical correlation of 77%, suggesting that models developed using data from PAMPA-BBB can forecast in vivo brain permeability. Given that majority of prior research has relied on in vitro or in vivo data for assessing BBB permeability, our model, developed using the largest PAMPA-BBB dataset to date, offers an orthogonal means to estimate BBB permeability of small molecules. We deposited a subset of our data into PubChem bioassay database (AID: 1845228) and deployed the best performing model on the NCATS Open Data ADME portal (https://opendata.ncats.nih.gov/adme/). These initiatives were undertaken with the aim of providing valuable resources for the drug discovery community.

RESUMEN

OBJECTIVES: Implementation barriers and lack of standardized point-of-care ultrasound (POCUS) curricula make the development of effective POCUS curricula and methods of assessment challenging. The authors aim to develop a longitudinal POCUS curriculum through staged intervention. In the first stage, the authors hypothesized that the use of high-fidelity ultrasound simulation during the Internal Medicine clerkship would improve POCUS confidence and knowledge among medical students, minimizing the need for trained faculty. METHODS: A quasi-experimental study of third-year students on the Internal Medicine clerkship at a large academic medical center in the United States was performed assessing the efficacy of ultrasound simulation use. The control group consisted of students who received baseline POCUS education during teaching rounds but did not have access to the ultrasound simulator. The experimental group consisted of students who, in addition to baseline POCUS education, had access to a high-fidelity ultrasound simulator throughout the clerkship for a minimum of 1 hour per week. Students in both the control and experimental groups completed a pre- and post-intervention confidence survey and knowledge-based examination. RESULTS: Eighty-two percent (50/61) of students completed pre- and post-tests, with the control group demonstrating no significant difference in POCUS confidence or knowledge. After exposure to the ultrasound simulator, the experimental group demonstrated statistically significant improvement in POCUS confidence and overall POCUS knowledge (p < .01). CONCLUSION: The use of high-fidelity ultrasound simulation can improve POCUS confidence and knowledge among medical students while addressing common barriers to the implementation of a POCUS curriculum. Despite showing statistically significant improvement in overall knowledge, the results did not appear to hold educational significance. Additional POCUS educational methods are necessary to overcome cognitive bias and potential overconfidence. The next stage of curriculum development will include resident-led POCUS workshops to supplement simulation.

RESUMEN

BACKGROUND: The topical drug delivery system has gained more attention in recent years as compared to oral and parenteral drug delivery. However, owing to the barrier function of the skin's topmost layer, only a few drug molecules can be administered by this route. Therefore, encapsulating the drugs in glycerosomes is one potential solution to this problem. Glycerosomes are vesicular drug delivery systems primarily made up of large concentrations of glycerol, phospholipid, water, and other active ingredients. OBJECTIVE: The main aim of this review is to summarize the most recent information on the encapsulated vesicular system used in cosmetic preparations, specifically glycerosomes made from both synthetic and naturally occurring plant bioactive substances. PURPOSE: Glycerosomes offer many benefits, including increased efficacy, better stability, improve absorption, drug targeting at specific sites, and delivering the same at a predetermined rate. METHOD: The mechanism behind the penetration of glycerosomes is the hydration and lipid fluidization of skin, fabricated by glycerol. RESULT: Numerous methods have been reported for the formulation of glycerosomes, including the thin film hydration method, reverse-phase evaporation, solvent spherule, detergent removal method, and so on. CONCLUSION: Researchers are currently investigating the potential of glycerosomes as nanocarriers for natural bioactive and synthetic drugs. This review describes the structure of glycerosomes, preparation techniques, applications, distinctions from liposomes, and benefits of glycerosomes.

Asunto(s)

Sistemas de Liberación de Medicamentos , Glicerol , Glicerol/química , Sistemas de Liberación de Medicamentos/métodos , Liposomas/química , Piel/metabolismo , Absorción Cutánea

RESUMEN

Peptic ulcer disease (PUD) is a well-known and commonly encountered gastrointestinal (GI) pathology. Helicobacter pylori and nonsteroidal anti-inflammatory drug (NSAID) use are the cause of the majority of PUD cases, although other rare etiologies may be encountered. PUD is confirmed by endoscopic visualization of gastric ulcers, with radiographic imaging being less impactful in diagnosis. In this paper, we present a middle-aged patient who presented with PUD caused by thrombotic occlusion of the left gastric artery (LGA), with her diagnosis being made with computed tomography (CT) imaging prior to endoscopy. This case emphasizes the importance of radiographic imaging in the undifferentiated patient, as well as the unique role radiologists play in both discovering diagnoses and their etiologies.

RESUMEN

Every year, nearly 60,000 hospitalizations occur in the United States due to chronic pancreatitis (CP). CP can cause severe chronic abdominal pain, pancreatic insufficiency, and increased risk of pancreatic cancer. While venous thrombotic complications are common, arterial thrombotic events are rarely reported in CP. This report describes a case of a 43-year-old female who presented with severe worsening abdominal pain due to CP. Diagnostic imaging disclosed thrombosis of superior mesenteric artery (SMA) and celiac artery (CA) with acute bowel wall changes reflecting ischemic changes, resulting in acute-on-chronic mesenteric ischemia. Endovascular stent placement relieved the ischemia with the resolution of pain. Arterial thrombosis should be considered as a diagnostic possibility when patients with CP present with a significant change in symptoms. Importantly, the case demonstrates that endovascular treatment with stent placement can relieve ischemia and resolve symptoms in patients with CP.

RESUMEN

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder that affects lysosome-related organelles, often leading to fatal pulmonary fibrosis (PF). The search for a treatment for HPS pulmonary fibrosis (HPSPF) is ongoing. S-MRI-1867, a dual cannabinoid receptor 1 (CB1R)/inducible nitric oxide synthase (iNOS) inhibitor, has shown great promise for the treatment of several fibrotic diseases, including HPSPF. In this study, we investigated the in vitro ADME characteristics of S-MRI-1867, as well as its pharmacokinetic (PK) properties in mice, rats, dogs, and monkeys. S-MRI-1867 showed low aqueous solubility (< 1 µg/mL), high plasma protein binding (>99%), and moderate to high metabolic stability. In its preclinical PK studies, S-MRI-1867 exhibited moderate to low plasma clearance (CLp) and high steady-state volume of distribution (Vdss) across all species. Despite the low solubility and P-gp efflux, S-MRI-1867 showed great permeability and metabolic stability leading to a moderate bioavailability (21-60%) across mouse, rat, dog, and monkey. Since the R form of MRI-1867 is CB1R-inactive, we investigated the potential conversion of S-MRI-1867 to R-MRI-1867 in mice and found that the chiral conversion was negligible. Furthermore, we developed and validated a PBPK model that adequately fits the PK profiles of S-MRI-1867 in mice, rats, dogs, and monkeys using various dosing regimens. We employed this PBPK model to simulate the human PK profiles of S-MRI-1867, enabling us to inform human dose selection and support the advancement of this promising drug candidate in the treatment of HPSPF.

Asunto(s)

Síndrome de Hermanski-Pudlak , Fibrosis Pulmonar , Humanos , Ratas , Ratones , Animales , Perros , Fibrosis Pulmonar/diagnóstico por imagen , Fibrosis Pulmonar/tratamiento farmacológico , Síndrome de Hermanski-Pudlak/tratamiento farmacológico , Proyectos de Investigación

RESUMEN

Pleurocutaneous fistula (PCF) is a pathological communication between the pleural space and subcutaneous tissue. This rare condition occurs as a complication of infection, malignancy, and therapeutic procedures such as tube thoracostomies. PCF is typically confirmed with computed tomography (CT) imaging. There is no current literature describing the post-traumatic causes of PCF. We describe a PCF related to multiple rib fractures and its rapid improvement following the placement of a chest tube. This case emphasizes the importance of prompt CT imaging in trauma patients and radiographically illustrates the progression and resolution of a post-traumatic PCF.

RESUMEN

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proven to be an effective means of decreasing COVID-19 mortality, hospitalization rates, and transmission. One of the vaccines deployed worldwide is ChAdOx1 nCoV-19, which uses an adenovirus vector to drive the expression of the original SARS-CoV-2 spike on the surface of transduced cells. Using cryo-electron tomography and subtomogram averaging, we determined the native structures of the vaccine product expressed on cell surfaces in situ. We show that ChAdOx1-vectored vaccines expressing the Beta SARS-CoV-2 variant produce abundant native prefusion spikes predominantly in one-RBD-up conformation. Furthermore, the ChAdOx1-vectored HexaPro-stabilized spike yields higher cell surface expression, enhanced RBD exposure, and reduced shedding of S1 compared to the wild type. We demonstrate in situ structure determination as a powerful means for studying antigen design options in future vaccine development against emerging novel SARS-CoV-2 variants and broadly against other infectious viruses.

RESUMEN

Cryo electron microscopy (cryo-EM) is used by biological research to visualize biomolecular complexes in 3D, but the heterogeneity of cryo-EM reconstructions is not easily estimated. Current processing paradigms nevertheless exert great effort to reduce flexibility and heterogeneity to improve the quality of the reconstruction. Clustering algorithms are typically employed to identify populations of data with reduced variability, but lack assessment of remaining heterogeneity. Here we develope a fast and simple algorithm based on spatial filtering to estimate the heterogeneity of a reconstruction. In the absence of flexibility, this estimate approximates macromolecular component occupancy. We show that our implementation can derive reasonable input parameters, that composition heterogeneity can be estimated based on contrast loss, and that the reconstruction can be modified accordingly to emulate altered constituent occupancy. This stands to benefit conventionally employed maximum-likelihood classification methods, whereas we here limit considerations to cryo-EM map interpretation, quantification, and particle-image signal subtraction.

Asunto(s)

Algoritmos , Microscopía por Crioelectrón , Análisis por Conglomerados

RESUMEN

Neisseria gonorrhoeae is one of the most common sexually transmitted infections in the United States, and disseminated infection can lead to a variety of complications. This includes the less common, but potentially life-threatening complication of gonococcal endocarditis. The authors report a case of a formerly incarcerated middle-aged man with a three-day history of dyspnea on exertion, fever, headache, and productive cough with green sputum. He endorsed a several-week history of an untreated right molar infection but denied any history of genitourinary symptoms. Given concerns for heart failure, a transthoracic echocardiogram was obtained showing mitral regurgitation with a mass on the mitral valve leaflet, as well as a smaller aortic valve mass that was subsequently confirmed with a transesophageal echocardiogram. Initially, the patient was transferred from an outside hospital (OSH), and discrepancies were noted between the blood cultures obtained at the OSH and a private lab. Given that the patient was already started on antibiotics prior to transfer, a Karius assay was sent and returned positive for N. gonorrhoeae. He was started on empiric antibiotic coverage before ultimately undergoing mitral valve replacement with a mosaic valve. The patient completed six weeks of intravenous ceftriaxone with complete resolution of symptoms. This case demonstrates a rare incident of N. gonorrhoeae bacteremia without any common symptoms causing endocarditis and valvular destruction. Timely diagnosis, a multidisciplinary approach, and treatment of gonococcal endocarditis led to positive outcomes in this case.

RESUMEN

Rivaroxaban (RXN) finds use in the management of pulmonary embolism and deep vein thrombosis. Its poor solubility (5-7 µg/mL) and P-gp-mediated efflux from intestinal lining limits the oral application of RXN. This work assessed the impact of liquisolid compact technique in augmenting the solubility and bioavailability of RXN. PEG 400, Avicel PH 200, and Aerosil 200 were used as non-volatile liquid, carrier, and coating material, respectively, to formulate RXN liquid-solid compacts (RXN LSCs). A 32-factor factorial design was used in the optimisation to assess the impacts of factors (load factor and carrier:coating ratio) on the responses (angle of repose and Q30 min). Pre-compression parameters of RXN LSCs suggested adequate flow and compressibility. Optimisation data suggested significant influence of factors on both the responses. Optimised RXN LSC-based tablets showed a significantly higher in vitro dissolution rate than RXN API and Xarelto® tablets due to improved solubility, reduced crystallinity, greater surface area, and enhanced wetting of RXN particles. XRD, DSC, and SEM data supported RXN's amorphization. The cytotoxicity (MTT assay) and permeation studies indicated the nontoxicity of prepared RXN LSC tablets and the role of PEG 400 in inhibiting P-gp. Pharmacokinetic study of RXN LSC-based tablets in Albino Wistar rats exhibited 2.51- and 1.66-times higher AUC in comparison to RXN API and Xarelto® tablets respectively, demonstrating that developed formulation had a greater oral bioavailability. The RXN LSC tablets showed longer bleeding times and higher rates of platelet aggregation than RXN API. Thus, RXN LSC tablets can be considered a facile, scalable technology.

Asunto(s)

Productos Biológicos , Animales , Ratas , Rivaroxabán , Polietilenglicoles , Disponibilidad Biológica , Excipientes , Ratas Wistar