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1.
J Neurochem ; 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38702968

RESUMO

Ependymal cells form a specialized brain-cerebrospinal fluid (CSF) interface and regulate local CSF microcirculation. It is becoming increasingly recognized that ependymal cells assume a reactive state in response to aging and disease, including conditions involving hypoxia, hydrocephalus, neurodegeneration, and neuroinflammation. Yet what transcriptional signatures govern these reactive states and whether this reactivity shares any similarities with classical descriptions of glial reactivity (i.e., in astrocytes) remain largely unexplored. Using single-cell transcriptomics, we interrogated this phenomenon by directly comparing the reactive ependymal cell transcriptome to the reactive astrocyte transcriptome using a well-established model of autoimmune-mediated neuroinflammation (MOG35-55 EAE). In doing so, we unveiled core glial reactivity-associated genes that defined the reactive ependymal cell and astrocyte response to MOG35-55 EAE. Interestingly, known reactive astrocyte genes from other CNS injury/disease contexts were also up-regulated by MOG35-55 EAE ependymal cells, suggesting that this state may be conserved in response to a variety of pathologies. We were also able to recapitulate features of the reactive ependymal cell state acutely using a classic neuroinflammatory cocktail (IFNγ/LPS) both in vitro and in vivo. Taken together, by comparing reactive ependymal cells and astrocytes, we identified a conserved signature underlying glial reactivity that was present in several neuroinflammatory contexts. Future work will explore the mechanisms driving ependymal reactivity and assess downstream functional consequences.

2.
Int Urogynecol J ; 35(3): 537-544, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38197952

RESUMO

INTRODUCTION AND HYPOTHESIS: Magnetic resonance defecography imaging techniques have been used widely to study pelvic floor function and diagnose pelvic organ prolapse (POP). The aim of this study was to investigate the diagnostic accuracy of the H-line to detect bladder descent compared with the current landmark, the pubococcygeal line (PCL). METHODS: In this retrospective cohort study, patients who underwent MR defecography in our medical center and were diagnosed with moderate to severe cystocele by radiological measurements were recruited. One rest image and one maximum evacuation image for each subject were used for the following measurements: bladder base perpendicular distance from the genital hiatus (GH), indicative of clinically significant bladder descent, PCL as the current radiological reference line, and the H-line, or minimal levator hiatus line, indicative of pelvic floor muscle and connective tissue support. Subjects were categorized as having clinically significant cystocele if the "bladder base" reached within 1 cm or lower of the GH (stage II or higher cystocele). A comparison was performed to assess differences and predictive capabilities of the reference lines relative to the GH measure. RESULTS: Seventy subjects were included, 30 with clinically significant bladder descent based on distance to GH. Women with bladder descent were older (64.0 ± 11.8 vs 51.2 ± 15.6, p < 0.001), had increased parity (3 [1-7] vs 2 [0-5], p = 0.009), and had a bladder that descended lower than the H-line at rest (1.9 ± 0.5 vs 2.2 ± 0.4, p = 0.003) and evacuation (-2.4 ± 1.6 vs -0.7 ± 1.1, p < 0.001). Multivariate regression analysis confirmed that age, length of the H-line at evacuation, the perpendicular distances between the H-line and the lowest bladder point at rest, and the PCL to the lowest bladder point at evacuation significantly correlated with bladder descent. Receiver operating characteristic analysis was used to identify a measurement threshold to diagnose clinically significant cystocele for both measurements, bladder base to the H-line: -1.2 (80.0, 72.5) area under the curve (AUC) 0.82, and bladder base PCL: -3.3 (77.8, 79.5) AUC 0.86. CONCLUSION: Our data support the application of using the minimal levator hiatus plane and specifically the H-line as a reliable landmark to diagnose bladder descent using MR defecography imaging.


Assuntos
Cistocele , Bexiga Urinária , Humanos , Feminino , Bexiga Urinária/diagnóstico por imagem , Defecografia/métodos , Estudos Retrospectivos , Diafragma da Pelve , Cistocele/diagnóstico por imagem , Cistocele/patologia , Imageamento por Ressonância Magnética/métodos
3.
Int Urogynecol J ; 34(7): 1627-1633, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36656345

RESUMO

INTRODUCTION AND HYPOTHESIS: Measurements of levator bowl volume using advanced imaging, may be predictive of pelvic floor muscle function. The aim of this study was to compare the volume of the levator bowl using both magnetic resonance imaging (MRI) and endovaginal ultrasound (EVU) of healthy asymptomatic women. METHODS: All participants underwent a comprehensive interview including completion of the Pelvic Floor Distress Inventory Questionnaire-20 questionnaire, pelvic examination with a pelvic organ prolapse quantification evaluation, MRI, and EVU. The pelvic floor was segmented using Slicer and the MRI segmentations were trimmed using two methods: soft-tissue landmarks and the field of view (FOV) of the ultrasound volume. The levator bowl volume of the 3D segmented shapes was measured using Blender's 3D printing toolkit. Normality was tested using the Shapiro-Wilks test and comparisons were made using self-paired t tests. RESULTS: The final analysis included 19 patients. Levator bowl volume measured via MRI was larger than that measured in EVU (46.1 ± 7.9 cm3 vs 27.4 ± 5.9 cm3, p<0.001). Reducing the FOV of the MRI to that of EVU caused the MRI volume to be much closer to the EVU volume (35.5 ± 3.3 cm3 vs 27.4 ± 5.9 cm3, p<0.001); however, it remained significantly larger. CONCLUSION: Levator bowl volume measured using MRI was larger than that measured using EVU no matter the method of delineation of the levator muscles. Although EVU is safe, cheap, and easy to perform, it captures a smaller volume of levator bowel than MRI.


Assuntos
Imageamento Tridimensional , Prolapso de Órgão Pélvico , Humanos , Feminino , Imageamento Tridimensional/métodos , Prolapso de Órgão Pélvico/diagnóstico , Ultrassonografia , Imageamento por Ressonância Magnética , Diafragma da Pelve
4.
Int Urogynecol J ; 34(10): 2399-2406, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37145123

RESUMO

INTRODUCTION AND HYPOTHESIS: Endovaginal ultrasound has long been hypothesized to have a significant effect on locations of what it visualizes. However, little work has directly quantified its effect. This study aimed to quantify it. METHODS: This cross-sectional study consisted of 20 healthy asymptomatic volunteers who underwent both endovaginal ultrasound and MRI. The urethra, vagina, rectum, pelvic floor, and pubic bone were segmented in both ultrasound and MRI using 3DSlicer. Then, using 3DSlicer's transform tool the volumes were rigidly aligned based on the posterior curvature of the pubic bone. The organs were then split into thirds along their long axis to compare their distal, middle, and proximal sections. Using Houdini, we compared the location of the centroid of each of the urethra, vagina, and rectum and the surface-to-surface difference of the urethra and rectum. The anterior curvature of the pelvic floor was also compared. Normality of all variables was assessed by Shapiro-Wilk test. RESULTS: The largest amount of surface-to-surface distance was observed in the proximal region for the urethra and rectum. Across all three organs, the majority of the deviation was in the anterior direction for geometries obtained from ultrasound versus those from MRI. For each subject, the trace defining the midline of the levator plate was more anterior for ultrasound compared to MRI. CONCLUSIONS: While it has often been assumed that placing a probe in the vagina probably distorts the anatomy, this study quantified the distortion and displacement of the pelvic viscera. This allows for better interpretation of clinical and research findings based on this modality.

5.
Int Urogynecol J ; 34(2): 535-543, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35794274

RESUMO

INTRODUCTION AND HYPOTHESIS: Pelvic organ prolapse (POP) is often diagnosed during an in-office examination, which looks for motion of the vaginal wall while performing a strain maneuver. It is believed that the pelvic organs in adequately supported women are relatively stationary. This study was aimed at investigating the physiological displacements of pelvic organs using MR defecography. METHODS: This prospective cohort study included 19 volunteers. Midsagittal slices representing rest and the maximum movement of the posterior vaginal fornix during three maneuvers were identified. Normalized axes for analysis were defined as the x' (line connecting the inferior-posterior-most point on the pubic symphysis to the anterior edge of the sacrococcygeal joint) and the y' (line orthogonal to the x axis that passed through the sacral promontory). The positions of the posterior vaginal fornix, mid-vagina, bladder neck, anorectal junction, and hymen were recorded. These subjects were then analyzed using the current radiological grading system of POP to determine any overlap between asymptomatic subjects and diagnostic ranges of POP. RESULTS: Evacuation caused the most motion in the landmarks. The majority of the motion of the landmarks was along the y axis. The posterior vaginal fornix experienced significant descent (125% of the initial distance) without much anterior-posterior translation (7% of the initial distance) during defecation. All landmarks experienced similar trends. CONCLUSIONS: We have shown that there is significant rotational motion of the pelvic organs around the pubic bone in adequately supported women. This motion when described using radiological grading is likely to be considered mild or moderate prolapse, which may contribute to overdiagnosis of POP.


Assuntos
Prolapso de Órgão Pélvico , Vísceras , Feminino , Humanos , Estudos Prospectivos , Prolapso de Órgão Pélvico/diagnóstico , Vagina , Diafragma da Pelve
6.
Int Urogynecol J ; 33(3): 551-561, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33787951

RESUMO

INTRODUCTION AND HYPOTHESIS: In Part 1, we observed urethral mechanics during Valsalva that oppose current continence theories. In this study, we utilize a finite element model to elucidate the role of supportive tissues on the urethra during Valsalva. By determining the sensitivity of urethral motion and deformations to variations in tissue stiffnesses, we formulate new hypotheses regarding mechanisms of urethral passive closure. METHODS: Anatomy was segmented from a nulliparous, continent woman at rest. The model was tuned such that urethral motion during Valsalva matched that observed in that patient. Urethra and surrounding tissue material properties were varied using Latin hypercube sampling to perform a sensitivity analysis. As in Part 1, urethral length, proximal and distal swinging, and shape parameters were measured at peak Valsalva for 50 simulations, and partial rank correlation coefficients were calculated between all model inputs and outputs. Cumulative influence factors determined which tissue properties were meaningfully influential (≥ 0.5). RESULTS: The material properties of the urethra, perineal membrane, bladder, and paraurethral connective tissues meaningfully influenced urethral motion, deformation, and shape. Reduction of the urethral stiffness and/or the perineal membrane soft constraint resulted in simulated urethral motions and shapes associated with stress urinary incontinence in Part 1. CONCLUSIONS: The data from Parts 1 and 2 suggest that connective tissues guide the controlled swinging motion and deformation of the urethra needed for passive closure during Valsalva. The swinging and kinking quantified in Part 1 and simulated in Part 2 are inconsistent with current continence theories.


Assuntos
Uretra , Incontinência Urinária por Estresse , Feminino , Humanos , Masculino , Bexiga Urinária , Urodinâmica , Manobra de Valsalva
7.
J Nanobiotechnology ; 20(1): 336, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35842657

RESUMO

Cationic non-viral vectors show great potential to introduce genetic material into cells, due to their ability to transport large amounts of genetic material and their high synthetic versatility. However, designing materials that are effective without showing toxic effects or undergoing non-specific interactions when applied systemically remains a challenge. The introduction of shielding polymers such as polyethylene glycol (PEG) can enhance biocompatibility and circulation time, however, often impairs transfection efficiency. Herein, a multicomponent polymer system is introduced, based on cationic and hydrophobic particles (P(nBMA46-co-MMA47-co-DMAEMA90), (PBMD)) with high delivery performance and a pH-responsive block copolymer (poly((N-acryloylmorpholine)-b-(2-(carboxy)ethyl acrylamide)) (P(NAM72-b-CEAm74), PNC)) as shielding system, with PNAM as alternative to PEG. The pH-sensitive polymer design promotes biocompatibility and excellent stability at extracellular conditions (pH 7.4) and also allows endosomal escape and thus high transfection efficiency under acidic conditions. PNC shielded particles are below 200 nm in diameter and showed stable pDNA complexation. Further, interaction with human erythrocytes at extracellular conditions (pH 7.4) was prevented, while acidic conditions (pH 6) enabled membrane leakage. The particles demonstrate transfection in adherent (HEK293T) as well as difficult-to-transfect suspension cells (K-562), with comparable or superior efficiency compared to commercial linear poly(ethylenimine) (LPEI). Besides, the toxicity of PNC-shielded particles was significantly minimized, in particular in K-562 cells and erythrocytes. In addition, a pilot in vivo experiment on bone marrow blood cells of mice that were injected with PNC-shielded particles, revealed slightly enhanced cell transfection in comparison to naked pDNA. This study demonstrates the applicability of cationic hydrophobic polymers for transfection of adherent and suspension cells in culture as well as in vivo by co-formulation with pH-responsive shielding polymers, without substantially compromising transfection performance.


Assuntos
Polietilenoglicóis , Polímeros , Animais , Cátions , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Polietilenoglicóis/química , Polímeros/química , Transfecção
8.
J Nanobiotechnology ; 19(1): 292, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34579715

RESUMO

Cationic polymers have been widely studied for non-viral gene delivery due to their ability to bind genetic material and to interact with cellular membranes. However, their charged nature carries the risk of increased cytotoxicity and interaction with serum proteins, limiting their potential in vivo application. Therefore, hydrophilic or anionic shielding polymers are applied to counteract these effects. Herein, a series of micelle-forming and micelle-shielding polymers were synthesized via RAFT polymerization. The copolymer poly[(n-butyl acrylate)-b-(2-(dimethyl amino)ethyl acrylamide)] (P(nBA-b-DMAEAm)) was assembled into cationic micelles and different shielding polymers were applied, i.e., poly(acrylic acid) (PAA), poly(4-acryloyl morpholine) (PNAM) or P(NAM-b-AA) block copolymer. These systems were compared to a triblock terpolymer micelle comprising PAA as the middle block. The assemblies were investigated regarding their morphology, interaction with pDNA, cytotoxicity, transfection efficiency, polyplex uptake and endosomal escape. The naked cationic micelle exhibited superior transfection efficiency, but increased cytotoxicity. The addition of shielding polymers led to reduced toxicity. In particular, the triblock terpolymer micelle convinced with high cell viability and no significant loss in efficiency. The highest shielding effect was achieved by layering micelles with P(NAM-b-AA) supporting the colloidal stability at neutral zeta potential and completely restoring cell viability while maintaining moderate transfection efficiencies. The high potential of this micelle-layer-combination for gene delivery was illustrated for the first time.


Assuntos
Técnicas de Transferência de Genes , Terapia Genética , Polímeros , Resinas Acrílicas , Animais , Cátions , Células HEK293 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Micelas , Plasmídeos , Polimerização , Transfecção
9.
J Nanobiotechnology ; 19(1): 70, 2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33676500

RESUMO

Although there has been substantial progress in the research field of gene delivery, there are some challenges remaining, e.g. there are still cell types such as primary cells and suspension cells (immune cells) known to be difficult to transfect. Cationic polymers have gained increasing attention due to their ability to bind, condense and mask genetic material, being amenable to scale up and highly variable in their composition. In addition, they can be combined with further monomers exhibiting desired biological and chemical properties, such as antioxidative, pH- and redox-responsive or biocompatible features. By introduction of hydrophobic monomers, in particular as block copolymers, cationic micelles can be formed possessing an improved chance of transfection in otherwise challenging cells. In this study, the antioxidant biomolecule lipoic acid, which can also be used as crosslinker, was incorporated into the hydrophobic block of a diblock copolymer, poly{[2-(dimethylamino)ethyl methacrylate]101-b-[n-(butyl methacrylate)124-co-(lipoic acid methacrylate)22]} (P(DMAEMA101-b-[nBMA124-co-LAMA22])), synthesized by RAFT polymerization and assembled into micelles (LAMA-mic). These micelles were investigated regarding their pDNA binding, cytotoxicity mechanisms and transfection efficiency in K-562 and HEK293T cells, the former representing a difficult to transfect, suspension leukemia cell line. The LAMA-mic exhibited low cytotoxicity at applied concentrations but demonstrated superior transfection efficiency in HEK293T and especially K-562 cells. In-depth studies on the transfection mechanism revealed that transfection efficiency in K-562 cells does not depend on the specific oncogenic fusion gene BCR-ABL alone. It is independent of the cellular uptake of polymer-pDNA complexes but correlates with the endosomal escape of the LAMA-mic. A comparison of the transfection efficiency of the LAMA-mic with structurally comparable micelles without lipoic acid showed that lipoic acid is not solely responsible for the superior transfection efficiency of the LAMA-mic. More likely, a synergistic effect of the antioxidative lipoic acid and the micellar architecture was identified. Therefore, the incorporation of lipoic acid into the core of hydrophobic-cationic micelles represents a promising tailor-made transfer strategy, which can potentially be beneficial for other difficult to transfect cell types.


Assuntos
Técnicas de Transferência de Genes , Leucemia/genética , Leucemia/terapia , Micelas , Polímeros/química , Ácido Tióctico/química , Ácido Tióctico/farmacologia , Animais , Antioxidantes , Cátions , Linhagem Celular Tumoral , DNA/química , Células HEK293 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Camundongos , Plasmídeos , Transfecção
10.
J Antimicrob Chemother ; 75(11): 3194-3201, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32790867

RESUMO

BACKGROUND: The rise of antimicrobial drug resistance in Mycobacterium tuberculosis coupled with the shortage of new antibiotics has elevated TB to a major global health priority. Repurposing drugs developed or used for other conditions has gained special attention in the current scenario of accelerated drug development for several global infectious diseases. In a similar effort, previous studies revealed that carprofen, a non-steroidal anti-inflammatory drug, selectively inhibited the growth of replicating, non-replicating and MDR clinical isolates of M. tuberculosis. OBJECTIVES: We aimed to reveal the whole-cell phenotypic and transcriptomic effects of carprofen in mycobacteria. METHODS: Integrative molecular and microbiological approaches such as resazurin microtitre plate assay, high-throughput spot-culture growth inhibition assay, whole-cell efflux inhibition, biofilm inhibition and microarray analyses were performed. Analogues of carprofen were also synthesized and assessed for their antimycobacterial activity. RESULTS: Carprofen was found to be a bactericidal drug that inhibited mycobacterial drug efflux mechanisms. It also restricted mycobacterial biofilm growth. Transcriptome profiling revealed that carprofen likely acts by targeting respiration through the disruption of membrane potential. The pleiotropic nature of carprofen's anti-TB action may explain why spontaneous drug-resistant mutants could not be isolated in practice. CONCLUSIONS: This immunomodulatory drug and its chemical analogues have the potential to reverse TB antimicrobial drug resistance, offering a swift path to clinical trials of novel TB drug combinations.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Carbazóis , Resistência Microbiana a Medicamentos , Humanos , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
11.
Molecules ; 25(3)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046221

RESUMO

Therapeutic treatment options for opportunistic non-tuberculous mycobacterial (NTM) infection and/or serious mycobacterial infections such as tuberculosis (TB) and leprosy are limited due to the spread of antimicrobial resistance mechanism. Plant-derived natural compounds as prospective efflux pump inhibitors may present a promising adjunct to conventional chemotherapy by enhancing mycobacterial susceptibility to antibiotics. This study served to evaluate the antimicrobial and resistance-modifying profile of a range of plant-derived flavonoids against the mycobacterial model strains: M. smegmatis, M. aurum, and M. bovis BCG. The minimum inhibitory concentrations (MICs) of the compounds against the mycobacterial strains were determined using both agar dilution and broth dilution assays, while their efflux inhibitory activity was investigated via an ethidium bromide-based fluorometric assay. All compounds were screened for their synergistic effects with ethidium bromide (EtBr) and rifampicin (RIF) against M. smegmatis. Skullcapflavone II (5,2'-dihydroxy-6,7,8,6'-tetramethoxyflavone, 1) exerted potent antimicrobial activity against M. aurum and M. bovis BCG and considerably increased the susceptibility of M. smegmatis to EtBr and RIF. Nobiletin (5,6,7,8,3',4'-hexamethoxyflavone, 2) was determined to be the most potent efflux-inhibitor in M. aurum and M. smegmatis. However, a connection between strong modulatory and putative efflux activity of the compounds could not be observed. Nevertheless, the results highlight two polymethoxyflavones, skullcapflavone II and nobiletin, with potent antimycobacterial and antibiotic resistance modulating activities as valuable adjuvants in anti-mycobacterial therapies.


Assuntos
Anti-Infecciosos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Flavonoides/farmacologia , Mycobacterium/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Transporte Biológico/efeitos dos fármacos , Etídio/química , Proteínas de Membrana Transportadoras/metabolismo , Testes de Sensibilidade Microbiana/métodos , Mycobacterium/metabolismo , Infecções por Mycobacterium/tratamento farmacológico , Rifampina/farmacologia
12.
Biomacromolecules ; 20(3): 1297-1307, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30694656

RESUMO

A synthetic cell mimic in the form of giant glycosylated polymersomes (GGPs) comprised of a novel amphiphilic diblock copolymer is reported. A synthetic approach involving a poly(dimethylsiloxane) (PDMS) macro-chain transfer agent (macroCTA) and postpolymerization modification was used to marry the hydrophobic and highly flexible properties of PDMS with the biological activity of glycopolymers. 2-Bromoethyl acrylate (BEA) was first polymerized using a PDMS macroCTA ( Mn,th ≈ 4900 g·mol-1, D = 1.1) to prepare well-defined PDMS- b-pBEA diblock copolymers ( D = 1.1) that were then substituted with 1-thio-ß-d-glucose or 1-thio-ß-d-galactose under facile conditions to yield PDMS- b-glycopolymers. Compositions possessing ≈25% of the glycopolymer block (by mass) were able to adopt a vesicular morphology in aqueous solution (≈210 nm in diameter), as indicated by TEM and light scattering techniques. The resulting carbohydrate-decorated polymersomes exhibited selective binding with the lectin concanavalin A (Con A), as demonstrated by turbidimetric experiments. Self-assembly of the same diblock copolymer compositions using an electroformation method yielded GGPs (ranging from 2-20 µm in diameter). Interaction of these cell-sized polymersomes with fimH positive E. coli was then studied via confocal microscopy. The glucose-decorated GGPs were found to cluster upon addition of the bacteria, while galactose-decorated GGPs could successfully interact with (and possibly immobilize) the bacteria without the onset of clustering. This demonstrates an opportunity to modulate the response of these synthetic cell mimics (protocells) toward biological entities through exploitation of selective ligand-receptor interactions, which may be readily tuned through a considered choice of carbohydrate functionality.


Assuntos
Dimetilpolisiloxanos/química , Escherichia coli/química , Polímeros/química , Glicosilação , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Transmissão , Nefelometria e Turbidimetria , Espalhamento de Radiação
13.
Org Biomol Chem ; 17(26): 6465-6469, 2019 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-31225568

RESUMO

Catalytic direct amidation reactions have been the focus of considerable recent research effort, due to the widespread use of amide formation processes in pharmaceutical synthesis. However, the vast majority of catalytic amidations are performed in non-polar solvents (aromatic hydrocarbons, ethers) which are typically undesirable from a sustainability perspective, and are often poor at solubilising polar carboxylic acid and amine substrates. As a consequence, most catalytic amidation protocols are unsuccessful when applied to polar and/or functionalised substrates of the kind commonly used in medicinal chemistry. In this paper we report a practical and useful catalytic direct amidation reaction using tert-butyl acetate as the reaction solvent. The use of an ester solvent offers improvements in terms of safety and sustainability, but also leads to an improved reaction scope with regard to polar substrates and less nucleophilic anilines, both of which are important components of amides used in medicinal chemistry. An amidation reaction was scaled up to 100 mmol and proceeded with excellent yield and efficiency, with a measured process mass intensity of 8.

14.
Biomacromolecules ; 19(8): 3190-3200, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-29890077

RESUMO

A range of well-defined guanidinium-rich linear polymers with demonstrable efficiency for cellular internalization were developed. A protected guanidinium-functional acrylamide monomer (di-Boc-guanidinium ethyl acrylamide, GEAdiBoc) was synthesized and then polymerized via RAFT polymerization to yield well-defined homopolymers, which were then deprotected and functionalized with a fluorescein dye to observe and quantify their cellular uptake. The cellular uptake of these homopolymers was first compared to analogous polyarginines, which are commonly used in modern drug delivery. Following this, a range of well-defined guanidinium-rich copolymers were prepared in which the monomer distribution was varied using a convenient one-pot sequential RAFT polymerization approach. Systematic quantification of the cell uptake of these compounds, supported by fluorescent confocal microscopy data, revealed that while the overall hydrophobicity of the resulting copolymers has a direct impact on the amount of copolymer taken up by cells, the distribution of monomers has an influence on both the extent of uptake and the relative extent to which each route of internalization (endocytosis vs direct translocation) is exploited.


Assuntos
Membrana Celular/efeitos dos fármacos , Guanidina/análogos & derivados , Polimerização , Acrilamidas/química , Células CACO-2 , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Guanidina/farmacologia , Humanos , Interações Hidrofóbicas e Hidrofílicas
15.
Macromol Rapid Commun ; 38(16)2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28675509

RESUMO

A photochemical strategy for the sequential dual compaction of single polymer chains is introduced. Two photoreactive methacrylates, with side chains bearing either a phenacyl sulfide (PS) or an α-methylbenzaldehyde (photoenol, PE) moiety, are selectively incorporated by one-pot iterative reversible-addition fragmentation chain transfer copolymerization into the outer blocks of a well-defined poly(methyl methacrylate) based ABC triblock copolymer possessing a nonfunctional spacer block (Mn = 23 400 g mol-1 , D = 1.2; ≈15 units of each photoreactive moieties of each type) as well as in model statistical copolymers bearing only one type of photoreactive unit. Upon UVA irradiation, PS and PE lead to highly reactive thioaldehydes and o-quinodimethanes, which rapidly react with dithiol and diacrylate linkers, respectively. The monomerfunctional copolymers are employed to establish the conditions for controlled intramolecular photo-crosslinking, which are subsequently applied to the bifunctional triblock copolymer. All compaction/folding experiments are monitored by size-exclusion chromatography and dynamic light scattering. The dual compaction consists of two events of dissimilar amplitude: the first folding step reveals a large reduction in hydrodynamic diameters, while the second compaction lead to a far less pronounced reduction of the single-chain nanoparticles size, consistent with the reduced degrees of freedom available after the first covalent compaction step.


Assuntos
Nanopartículas/química , Polímeros/síntese química , Metacrilatos/química , Fotoquímica , Polimerização , Raios Ultravioleta
16.
Rheumatol Int ; 34(10): 1449-53, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24682439

RESUMO

Prior research has identified differences between sexes in rheumatoid arthritis (RA) disease characteristics and treatment response, but not how these differences affect therapeutic decision making to switch therapy. Our objective was to assess for sex differences in RA disease activity during the course of biologic therapy and how these differences impact drug survival and therapeutic switching. Data from the Alberta Biologics Pharmacosurveillance Program, a population-based observational cohort of patients receiving biologic therapy for RA, were used for a sex-stratified analysis of disease activity. Linear mixed-model analysis was applied to compare continuous effectiveness outcomes (DAS28, HAQ scores, visual analogue scales of patient-reported outcomes). Chi-squared tests and log-rank tests were used to determine differences in the frequency of switching and drug survival between females and males. At biologic initiation, females (n = 419) and males (n = 148) had similar disease activity (DAS28 in females 5.83, males 5.72), but females reported worse function (HAQ 1.64 vs 1.51, p = 0.037) and more fatigue (6.7 vs 5.9/10, p = 0.013), but the same global score as males (6.9 vs 6.8/10). During biologic therapy, females reported more fatigue (ß = -0.454, 95 % CI -0.852, -0.056, p = 0.0252), worse function (ß = -0.183, 95 % CI -0.291, -0.074, p = 0.0010) and higher DAS28 scores (ß = -0.401, 95 % CI -0.617, -0.184, p = 0.0003). A new composite disease activity index, the HUPI, eliminated the observed differences in disease activity scores between females and males. Median survival for biologic-naïve patients was similar between sexes (3.7 years males, 3.3 years females, log-rank test p = 0.25). The frequency of switching and survival on subsequent biologics were the same between females and males. Guided by traditional outcome measurement tools, worse disease activity and patient-reported outcomes through the course of therapy did not translate into differences in drug survival or more frequent switching for females on biologic therapy for RA.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Produtos Biológicos/uso terapêutico , Artrite Reumatoide/diagnóstico , Estudos de Coortes , Substituição de Medicamentos , Feminino , Humanos , Masculino , Sistema de Registros , Índice de Gravidade de Doença , Fatores Sexuais , Resultado do Tratamento
17.
Ann Biomed Eng ; 52(2): 292-301, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37828266

RESUMO

Remodeling of the sacrum and coccyx to accommodate pregnancy and delivery has been hypothesized but not directly quantified. This study aimed to quantify the remodeling of the sacrum and coccyx by comparing midsagittal lengths, angles, curvature, and shape between nulliparous, pregnant, and parous women using both 2 and 3 dimensional measures. Ninety pelvic magnetic resonance images of the pelvis were retrospectively collected and segmented. Twelve length, angle, and curvature measurements were made using definitions from previous literature on the midsagittal plane to define the sacrum, coccyx, and combined sacrum-coccyx shape. These measures were followed by a statistical shape analysis, which returned modes of variation and principal component scores. A separate MANCOVA analysis was conducted for both the 2D and 3D measures. The 2D and 3D analyses agreed that pregnant women had a significantly straighter coccyx and combined sacrum/coccyx than nulliparous (9.1% and 5.6%, respectively) and parous (7.5% and 2.7%, respectively) subjects. All comparisons showed that, on average, a pregnant woman's sacrum and coccyx were significantly straighter than their nulliparous counterparts. Then after delivery, the sacrum/coccyx returned, but not completely back to a more curved configuration.


Assuntos
Cóccix , Sacro , Humanos , Feminino , Gravidez , Estudos Retrospectivos , Pelve , Imageamento por Ressonância Magnética
18.
Adv Sci (Weinh) ; : e2401935, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837626

RESUMO

Lipidic nanocarriers are a broad class of lipid-based vectors with proven potential for packaging and delivering emerging nucleic acid therapeutics. An important early step in the clinical development cycle is large-scale screening of diverse formulation libraries to assess particle quality and payload delivery efficiency. Due to the size of the screening space, this process can be both costly and time-consuming. To address this, computational models capable of predicting clinically relevant physio-chemical properties of dendrimer-lipid nanocarriers, along with their mRNA payload delivery efficiency in human cells are developed. The models are then deployed on a large theoretical nanocarrier pool consisting of over 4.5 million formulations. Top predictions are synthesised for validation using cell-based assays, leading to the discovery of a high quality, high performing, candidate. The methods reported here enable rapid, high-throughput, in silico pre-screening for high-quality candidates, and have great potential to reduce the cost and time required to bring mRNA therapies to the clinic.

19.
Comput Methods Programs Biomed ; 244: 107938, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38056313

RESUMO

BACKGROUND AND OBJECTIVES: Finite element simulations are widely employed as a non-invasive and cost-effective approach for predicting outcomes in biomechanical simulations. However, traditional finite element software, primarily designed for engineering materials, often encountered limitations in contact detection and enforcement, leading to simulation failure when dealing with complex biomechanical configurations. Currently, a lot of model tuning is required to get physically accurate finite element simulations without failures. This adds significant human interaction to each iteration of a biomechanical model. This study addressed these issues by introducing PolyFEM, a novel finite element solver that guarantees inversion- and intersection-free solutions with completely automatic collision detection. The objective of this research is to validate PolyFEM's capabilities by comparing its results with those obtained from a well-established finite element solver, FEBio. METHODS: To achieve this goal, five comparison scenarios were formulated to assess and validate PolyFEM's performance. The simulations were reproduced using both PolyFEM and FEBio, and the final results were compared. The five comparison scenarios included: (1) reproducing simulations from the FEBio test suite, consisting of static, dynamic, and contact-driven simulations; (2) replicating simulations from the verification paper published alongside the original release of FEBio; (3) a biomechanically based contact problem; (4) creating a custom simulation involving high-energy collisions between soft materials to highlight the difference in collision methods between the two solvers; and (5) performing biomechanical simulations of biting and quasi-stance. RESULTS: We found that PolyFEM was capable of replicating all simulations previously conducted in FEBio. Particularly noteworthy is PolyFEM's superiority in high-energy contact simulations, where FEBio fell short, unable to complete over half of the simulations in Scenario 4. Although some of the simulations required significantly more simulation time in PolyFEM compared to FEBio, it is important to highlight that PolyFEM achieved these results without the need for any additional model tuning or contact declaration. DISCUSSION: Despite being in the early stages of development, PolyFEM currently provides verified solutions for hyperelastic materials that are consistent with FEBio, both in previously published workflows and novel finite element scenarios. PolyFEM exhibited the ability to tackle challenging biomechanical problems where other solvers fell short, thus offering the potential to enhance the accuracy and realism of future finite element analyses.


Assuntos
Software , Humanos , Simulação por Computador , Fenômenos Biomecânicos , Análise de Elementos Finitos
20.
Ann Rheum Dis ; 72(10): 1664-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23117244

RESUMO

OBJECTIVE: Determine healthcare service utilisation costs among patients using biological therapies for rheumatoid arthritis (RA), considering the magnitude and duration of patient response achieved. METHODS: Clinical data from the Alberta Biologics Pharmacosurveillance Program (ABioPharm) was linked with provincial physician billing claims, outpatient visits and hospitalisations. The annual mean healthcare service utilisation costs (total, RA-attributable, non-RA attributable) were estimated for patients during the best disease activity level reached during treatment. RESULTS: Of 1086 patients: 16% achieved DAS28 remission >1 year, 37% had a DAS28 remission period <1 year, 13% had a low disease activity (LDA) period <1 year and 31% had persistent moderate or high disease activity. Mean annual healthcare service utilisation cost savings for those in sustained remission was $2391 (95% CI 1437 to 3909, p<0.001) and $2104 (95% CI 838 to 3512, p<0.001) for those with non-sustained LDA, relative to the persistent disease activity group. Savings were also observed for those in sustained remission compared to non-sustained remission (annual savings $1422, 95% CI 564 to 2796, p<0.001). RA-related costs were consistent across disease activity and cost categories; the majority of costs were attributable to non-RA related hospitalisations. CONCLUSIONS: We provide evidence of economic benefits to the healthcare system when RA patients achieve persistent good disease control. Benefits from brief periods of remission and LDA are also observed. Coupled with an expected increase in productivity from improved disease control, there is societal benefit to the utilisation of biologics in RA management to achieve treatment goals.


Assuntos
Artrite Reumatoide/economia , Custos de Cuidados de Saúde/estatística & dados numéricos , Adulto , Idoso , Alberta , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Produtos Biológicos/uso terapêutico , Feminino , Serviços de Saúde/estatística & dados numéricos , Pesquisa sobre Serviços de Saúde/métodos , Hospitalização/economia , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Registro Médico Coordenado , Pessoa de Meia-Idade , Indução de Remissão , Índice de Gravidade de Doença , Fator de Necrose Tumoral alfa/antagonistas & inibidores
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