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1.
bioRxiv ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38617369

RESUMO

The Rep68 protein from Adeno-Associated Virus (AAV) is a multifunctional SF3 helicase that performs most of the DNA transactions required for the viral life cycle. During AAV DNA replication, Rep68 assembles at the origin and catalyzes the DNA melting and nicking reactions during the hairpin rolling replication process to complete the second-strand synthesis of the AAV genome. Here, we report the Cryo-EM structures of Rep68 bound to double-stranded DNA (dsDNA) containing the sequence of the AAVS1 integration site in different nucleotide-bound states. In the apo state, Rep68 forms a heptameric complex around DNA, with three Origin Binding Domains (OBDs) bound to the Rep Binding Site (RBS) sequence and three other OBDs forming transient dimers with them. The AAA+ domains form an open ring with no interactions between subunits and with DNA. We hypothesize the heptameric quaternary structure is necessary to load onto dsDNA. In the ATPγS-bound state, a subset of three subunits binds the nucleotide, undergoing a large conformational change, inducing the formation of intersubunit interactions interaction and interaction with three consecutive DNA phosphate groups. Moreover, the induced conformational change positions three phenylalanine residues to come in close contact with the DNA backbone, producing a distortion in the DNA. We propose that the phenylalanine residues can potentially act as a hydrophobic wedge in the DNA melting process.

2.
Colloids Surf B Biointerfaces ; 237: 113837, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38508086

RESUMO

Ultra Violet radiations induced skin damage and associated skin disorders are a widespread concern. The consequences of sun exposure include a plethora of dermal conditions like aging, solar urticaria, albinism and cancer. Sunscreens provide effective protection to skin from these damages. Besides FDA approved physical and chemical UV filters, phytoconstituents with their multi functionalities are emerging as frontrunners in Therapy of skin disorders. Objective of this study was to develop novel phyto-dermal gel (PDG) with dual action of sun protection and antioxidant potential using polymeric mixed micelles (PMMs) are nanocarriers. PMMs of Pluronic F127 and Pluronic F68 loaded with curcumin and quercetin were optimized by 32 factorial designs. Responses studied were vesicle size, SPF, entrapment efficiency of curcumin and quercetin and antioxidant activity. Droplet size ranged from 300 to 500 nm with PDI in between 0.248 and 0.584. Combination of curcumin and quercetin showed enhanced sun protection and antioxidant activity. Pluronics played a significant positive role in various parameters. In present studies vesicle size of factorial batches was found to be between 387 and 527 nm, and SPF was found to be between 18.86 and 28.32. Transmission electron microscopy revealed spherical morphology of micelles. Optimized micelles were incorporated into Carbopol 940. Optimized PDG was evaluated for pH, drug content, spreadability, rheology, syneresis, ex vivo permeation, and skin retention. Hysteresis loop in the rheogram suggested thixotropy of PDG. Syneresis for gels from day 0-30 days was found to be between 0% and 12.46% w/w. SPF of optimized PDG was 27±0.5. Optimized PDG showed no signs of erythema and edema on Wistar rats. PMMs thus effectively enhanced antioxidant and skin protective effect of curcumin and quercetin.


Assuntos
Cosmecêuticos , Curcumina , Ratos , Animais , Micelas , Curcumina/farmacologia , Curcumina/química , Antioxidantes/farmacologia , Quercetina/farmacologia , Ratos Wistar , Poloxâmero/química , Polímeros/química , Géis , Portadores de Fármacos/química , Tamanho da Partícula
4.
Small ; 20(4): e2304393, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37712098

RESUMO

Healed defects on photocatalysts surface and their interaction with plasmonic nanoparticles (NPs) have attracted attention in H2 production process. In this study, surface oxygen vacancy (Vo ) defects are created on ZnO (Vo -ZnO) NPs by directly pyrolyzing zeolitic imidazolate framework. The surface defects on Vo -ZnO provide active sites for the diffusion of single Au atoms and as nucleation sites for the formation of Au NPs by the in situ photodeposition process. The electronically healed surface defects by single Au atoms help in the formation of a heterojunction between the ZnO and plasmonic Au NPs. The formed Au/Vo -Au:ZnO-4 heterojunction prolongs photoelectron lifetimes and increases donor charge density. Therefore, the optimized photocatalysts of Au/Vo -Au:ZnO-4 has 21.28 times higher H2 production rate than the pristine Vo -ZnO under UV-visible light in 0.35 m Na2 SO4 and 0.25 m Na2 SO3 . However in 0.35 m Na2 S and 0.25 m Na2 SO3 , the H2 production rate is 25.84 mmole h-1 g-1 . Furthermore, Au/Vo -Au:ZnO-4 shows visible light activity by generating hot carries via induced surface plasmonic effects. It has 48.58 times higher H2 production rate than pristine Vo -ZnO. Therefore, this study infers new insight for defect healing mediated preparation of Au/Vo -Au:ZnO heterojunction for efficient photocatalytic H2 production.

5.
Molecules ; 28(13)2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37446655

RESUMO

Inflammation is the response of the innate immune system to any type of injury. Although acute inflammation is critical for survival, dysregulation of the innate immune response leads to chronic inflammation. Many synthetic anti-inflammatory drugs have side effects, and thus, natural anti-inflammatory compounds are still needed. Cannabis sativa L. may provide a good source of anti-inflammatory molecules. Here, we tested the anti-inflammatory properties of cannabis extracts and pure cannabinoids in lipopolysaccharide (LPS)-induced inflammation in human THP-1 macrophages. We found that pre-treatment with cannabidiol (CBD), delta-9-tetrahydrocannabinol (THC), or extracts containing high levels of CBD or THC reduced the level of induction of various cytokines. The CBD was more efficient than THC, and the extracts were more efficient than pure cannabinoids. Finally, IL-6, IL-10, and MCP-1 cytokines were most sensitive to pre-treatments with CBD and THC, while IL-1ß, IL-8, and TNF-α were less responsive. Thus, our work demonstrates the potential of the use of cannabinoids or/and cannabis extracts for the reduction of inflammation and establishes IL-6 and MCP-1 as the sensitive markers for the analysis of the effect of cannabinoids on inflammation in macrophages.


Assuntos
Canabidiol , Canabinoides , Cannabis , Alucinógenos , Humanos , Anti-Inflamatórios/farmacologia , Canabidiol/análise , Agonistas de Receptores de Canabinoides , Canabinoides/farmacologia , Canabinoides/uso terapêutico , Citocinas , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Interleucina-6 , Lipopolissacarídeos/toxicidade , Macrófagos , Extratos Vegetais/farmacologia
6.
J Colloid Interface Sci ; 642: 540-553, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37028161

RESUMO

Resistive switching (RS) memories have attracted great attention as promising solutions to next-generation non-volatile memories and computing technologies because of their simple device configuration, high on/off ratio, low power consumption, fast switching, long retention, and significant cyclic stability. In this work, uniform and adherent iron tungstate (FeWO4) thin films were synthesized by the spray pyrolysis method with various precursor solution volumes, and these were tested as a switching layer for the fabrication of Ag/FWO/FTO memristive devices. The detailed structural investigation was done through various analytical and physio-chemical characterizations viz. X-ray diffraction (XRD) and its Rietveld refinement, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques. The results reveal the pure and single-phase FeWO4 compound thin film formation. Surface morphological study shows the spherical particle formation having a diameter in the range of 20 to 40 nm. The RS characteristics of the Ag/FWO/FTO memristive device demonstrate non-volatile memory characteristics with significant endurance and retention properties. Interestingly, the memory devices show stable and reproducible negative differential resistance (NDR) effects. The in-depth statistical analysis suggests the good operational uniformity of the device. Moreover, the switching voltages of the Ag/FWO/FTO memristive device were modeled using the time series analysis technique by utilizing Holt's Winter Exponential Smoothing (HWES) approach. Additionally, the device mimics bio-synaptic properties such as potentiation/depression, excitatory post-synaptic current (EPSC), and spike-timing-dependent plasticity (STDP) learning rules. For the present device, the space-charge-limited current (SCLC) and trap-controlled-SCLC effects dominated during positive and negative bias I-V characteristics, respectively. The RS mechanism dominated in the low resistance state (LRS), and the high resistance state (HRS) was explained based on the formation and rupture of conductive filament composed of Ag ions and oxygen vacancies. This work demonstrates the RS in the metal tungstate-based memristive devices and demonstrates a low-cost approach for fabricating memristive devices.

7.
J Pharm Sci ; 112(2): 471-481, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36130676

RESUMO

The rational design and selection of formulation composition to meet molecule-specific and product-specific needs are critical for biotherapeutics development to ensure physical and chemical stability. This work, based on three antibody-based (mAb) proteins (mAbA, mAbB, and mAbC), evaluates residue-specific impact of EDTA and methionine on protein oxidation, using an integrated biotherapeutics drug product development workflow. This workflow includes statistical experimental design, high-throughput experimental automation and execution, structure-based in silico modeling, inferential statistical analysis, and enhanced interactive data visualization of large datasets. This oxidation study evaluates the impact of formulation parameters including pH, protein concentration, and the presence of polysorbate 80 on the oxidation of specific conserved and variable residues of mAbs A, B, and C in the presence of stressors (iron, peroxide) and/or protectants (EDTA, L-methionine). Residue-specific analysis by automated high-throughput peptide mapping demonstrates differential residue-specific effects of EDTA and methionine in protecting against oxidation, highlighting the need for molecule-specific and product-specific selection of these excipients during formulation development. Computational modeling based on a homology model and the two-shell water coordination method (WCN) was employed to gain mechanistic understanding of residue-specific oxidation susceptibility of methionine residues. The computational determinants of local solvent exposure of methionine residues showed good correlation of WCN with experimentally determined oxidation for corresponding residues. The rapid generation of high-resolution data, statistical data analysis and interactive visualization of the high-throughput residue-level data containing ∼200 unique formulations facilitate residue-specific, molecule-specific and product-specific oxidation (global and local) assessment for oxidation protectants during early development for mAbs and related mAb-based modalities.


Assuntos
Metionina , Racemetionina , Metionina/química , Ácido Edético , Fluxo de Trabalho , Racemetionina/metabolismo , Oxirredução
8.
Cells ; 11(9)2022 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-35563697

RESUMO

Cannabinoids, mainly cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), are the most studied group of compounds obtained from Cannabis sativa because of their several pharmaceutical properties. Current evidence suggests a crucial role of cannabinoids as potent anti-inflammatory agents for the treatment of chronic inflammatory diseases; however, the mechanisms remain largely unclear. Cytokine storm, a dysregulated severe inflammatory response by our immune system, is involved in the pathogenesis of numerous chronic inflammatory disorders, including coronavirus disease 2019 (COVID-19), which results in the accumulation of pro-inflammatory cytokines. Therefore, we hypothesized that CBD and THC reduce the levels of pro-inflammatory cytokines by inhibiting key inflammatory signaling pathways. The nucleotide-binding and oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling has been implicated in a variety of chronic inflammatory diseases, which results in the release of pyroptotic cytokines, interleukin-1ß (IL-1ß) and IL-18. Likewise, the activation of the signal transducer and activator of transcription-3 (STAT3) causes increased expression of pro-inflammatory cytokines. We studied the effects of CBD and THC on lipopolysaccharide (LPS)-induced inflammatory response in human THP-1 macrophages and primary human bronchial epithelial cells (HBECs). Our results revealed that CBD and, for the first time, THC significantly inhibited NLRP3 inflammasome activation following LPS + ATP stimulation, leading to a reduction in the levels of IL-1ß in THP-1 macrophages and HBECs. CBD attenuated the phosphorylation of nuclear factor-κB (NF-κB), and both cannabinoids inhibited the generation of oxidative stress post-LPS. Our multiplex ELISA data revealed that CBD and THC significantly diminished the levels of IL-6, IL-8, and tumor necrosis factor-α (TNF-α) after LPS treatment in THP-1 macrophages and HBECs. In addition, the phosphorylation of STAT3 was significantly downregulated by CBD and THC in THP-1 macrophages and HBECs, which was in turn attributed to the reduced phosphorylation of tyrosine kinase-2 (TYK2) by CBD and THC after LPS stimulation in these cells. Overall, CBD and THC were found to be effective in alleviating the LPS-induced cytokine storm in human macrophages and primary HBECs, at least via modulation of NLRP3 inflammasome and STAT3 signaling pathways. The encouraging results from this study warrant further investigation of these cannabinoids in vivo.


Assuntos
COVID-19 , Canabidiol , Canabinoides , Canabidiol/farmacologia , Canabinoides/farmacologia , Síndrome da Liberação de Citocina , Citocinas/metabolismo , Dronabinol/farmacologia , Humanos , Inflamassomos/metabolismo , Lipopolissacarídeos/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , TYK2 Quinase/metabolismo , TYK2 Quinase/farmacologia
10.
Haemophilia ; 28(2): 286-291, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35014121

RESUMO

INTRODUCTION: von Willebrand disease (VWD) is the common bleeding disorder with a clinically relevant bleeding prevalence of 1:10,000. von Willebrand disease patients lack both von Willebrand factor (VWF) and factor VIII (FVIII), which are critical for normal haemostasis. The conventional treatment for VWD includes desmopressin and replacement therapy with plasma derived FVIII with VWF concentrates or recombinant VWF. Development of alloantibodies is a rare occurrence, there is a paucity in the literature of treatment modalities in these patients. Not many reports are available in literature on the efficacy of emicizumab in VWD patients with or without alloantibodies to VWF. AIM: To do systematic review of literature on emicizumab in VWD and report our experience of emicizumab in two patients of VWD METHODS: We used electronic search engines till May 2021 in 'Google scholar' and 'PubMed', to collect the case reports or case series on use of emicizumab for management of VWD. Two of our severe VWD patients were successfully treated with emicizumab. A systematic review was performed and the results discussed. RESULTS: The electronic search revealed six case reports using emicizumab for treatment of VWD. Two were in vitro studies and four in patients with VWD type 3 disease. In vitro studies and in VWD patients on emicizumab, showed improvement in thrombin generation and fibrin formation. Among four patients, three had alloantibodies to VWD and one was negative. All these patients were treated with emicizumab for 6-12 m. After starting emicizumab, none of them had spontaneous bleeding requiring treatment. During treatment with emicizumab, one patient had trauma-associated soft tissue hematoma, which was treated with rFVIIa and another patient had bleeding following dental exfoliation treated with Humate P. We treated two of our VWD patients one with and one without inhibitors with emicizumab after failure of other therapies. Both the patients showed marked improvement and continued to remain well and free of bleeding episodes. None of the patients had any thrombosis or thrombotic microangiopathy (TMA) during treatment with emicizumab. CONCLUSION: In conclusion, this review supports the safety and efficacy of emicizumab in type 3 VWD patients with or without alloantibodies. Further large studies are required to confirm the safety and efficacy of emicizumab in VWD.


Assuntos
Anticorpos Biespecíficos , Doenças de von Willebrand , Anticorpos Biespecíficos/uso terapêutico , Anticorpos Monoclonais Humanizados , Fator VIII , Humanos , Isoanticorpos , Doenças de von Willebrand/complicações , Doenças de von Willebrand/tratamento farmacológico , Fator de von Willebrand
11.
Childs Nerv Syst ; 37(12): 3769-3775, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34611764

RESUMO

Atypical teratoid/rhabdoid tumors (AT/RTs) are aggressive embryonal neoplasms of the central nervous system that correspond to WHO grade IV and have a dismal prognosis. The latest Central Brain Tumor Registry of the United States data shows that AT/RT constitutes 16.6% of all embryonal tumors in children. The molecular hallmark of this tumor is pathogenic SMARCB1 genetic alterations resulting in the loss of INI-1 immunopositivity, with fewer tumors harboring SMARCA4 (BRG1) variants. Maternal embryonal leucine zipper kinase (MELK) is a member of the Snf1/AMPK family of serine/threonine-protein kinases involved in various processes such as cell cycle regulation, self-renewal of stem cells, apoptosis, and splicing regulation. Recent studies have highlighted the involvement of MELK in AT/RT and its possible therapeutic role. The purpose of this study was to review the histological and immunohistochemical profile of AT/RT with special reference to MELK  staining. In this retrospective study conducted over 6 years, all diagnosed cases of AT/RT, defined by loss of INI-1 immunopositivity, were retrieved and studied. Demographic details of patients and microscopic findings were analyzed, with special attention to histological patterns and immunohistochemistry profile including MELK immunoreactivity. There were 50 cases of AT/RT diagnosed in the specified period. Of the cases operated at our institute during this period, embryonal tumors constituted 20.6% of all pediatric brain tumors with AT/RT representing 12.6% of this subset. The median age at presentation was 3.5 years (range: 8 months-22 years) and there were three adult cases. Males outnumbered females by a ratio of 1.94:1. Tumor location was distributed equally between the supratentorial and infratentorial compartments. Characteristic rhabdoid cells were identified in 70% of cases. Areas with epithelial, mesenchymal, and undifferentiated tumor cells were seen in 8%, 20%, and 52% of cases, respectively. Cells with vacuolated cytoplasm were noted in 28% of cases. Immunohistochemistry (IHC) showed a polyimmunophenotypic profile with immunopositivity for GFAP in 70%, Vimentin in 100%, SMA in 68%, and EMA in 88% of cases, indicating the remarkable heterogeneity of the tumor cells. MELK immunopositivity was noted in 83.33% of cases. Thus, atypical teratoid/rhabdoid tumors are rare neoplasms. In line with other studies, we show that these tumors occur predominantly in very young children and display marked variability on histology and IHC with loss of INI-1. MELK is presumed to be an important molecule involved in cell cycle regulation, proliferation, and other critical functions. High expression of MELK in AT/RT may suggest its plausible role in neoplastic transformation of embryonic and postnatal multipotent neural progenitors which in turn could explain the diverse morphological and immunohistochemical characteristics observed in these tumors.


Assuntos
Tumor Rabdoide , Teratoma , Pré-Escolar , DNA Helicases , Feminino , Humanos , Zíper de Leucina , Masculino , Proteínas Nucleares , Proteínas Serina-Treonina Quinases , Estudos Retrospectivos , Tumor Rabdoide/genética , Teratoma/genética , Fatores de Transcrição/genética
12.
BMC Biol ; 19(1): 231, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34706739

RESUMO

BACKGROUND: The detection of environmental cues and signals via the sensory system directs behavioral choices in diverse organisms. Insect larvae rely on input from the chemosensory system, mainly olfaction, for locating food sources. In several lepidopteran species, foraging behavior and food preferences change across larval instars; however, the molecular mechanisms underlying such behavioral plasticity during larval development are not fully understood. Here, we hypothesize that expression patterns of odorant receptors (ORs) change during development, as a possible mechanism influencing instar-specific olfactory-guided behavior and food preferences. RESULTS: We investigated the expression patterns of ORs in larvae of the cotton leafworm Spodoptera littoralis between the first and fourth instar and revealed that some of the ORs show instar-specific expression. We functionally characterized one OR expressed in the first instar, SlitOR40, as responding to the plant volatile, ß-caryophyllene and its isomer α-humulene. In agreement with the proposed hypothesis, we showed that first but not fourth instar larvae responded behaviorally to ß-caryophyllene and α-humulene. Moreover, knocking out this odorant receptor via CRISPR-Cas9, we confirmed that instar-specific responses towards its cognate ligands rely on the expression of SlitOR40. CONCLUSION: Our results provide evidence that larvae of S. littoralis change their peripheral olfactory system during development. Furthermore, our data demonstrate an unprecedented instar-specific behavioral plasticity mediated by an OR, and knocking out this OR disrupts larval behavioral plasticity. The ecological relevance of such behavioral plasticity for S. littoralis remains to be elucidated, but our results demonstrate an olfactory mechanism underlying this plasticity in foraging behavior during larval development.


Assuntos
Receptores Odorantes , Spodoptera , Animais , Larva , Receptores Odorantes/genética , Olfato , Spodoptera/genética
13.
Med J Armed Forces India ; 77: S393-S397, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34334909

RESUMO

BACKGROUND: Patients with type 1 diabetes mellitus (DM) require intensive monitoring, which was adversely affected during coronavirus disease 2019 (COVID-19) restrictions. METHODS: We evaluated the management of type 1 DM and the role of telephonic consultation and follow-up in 46 patients (10 on insulin pump) with type 1 DM at our centre from 1 February 2020 to 31 January 2021. Patients were telephonically counselled fortnightly. Web-based diabetes education sessions for the patients and parents were conducted. Finally, change in HbA1c during the period of the study, frequency of severe hypoglycaemia, hospital admissions for hyperglycaemic emergencies and degree of satisfaction with care rendered by the treating team were assessed by ratings scored by the patients. RESULTS: Five episodes of severe hypoglycaemia were noted in three patients. Two patients had diabetic ketoacidosis. Patients on insulin pump showed a mean baseline HbA1c of 7.8%. Nine of these patients (90%) showed an improvement in Hba1c during the study period compared to 64.3% of patients on conventional regimen. There were no episodes of severe hypoglycaemia or hospitalization with DKA noted in these patients. Only two patients had COVID-19 disease with mild manifestations. Overall satisfaction levels with therapy were high. CONCLUSION: This study illustrates the role played by teleconsultation and video conferencing during the period of the COVID-19 pandemic in ensuring optimal healthcare delivery to patients with type 1 DM. Some of these methods can be used even after the pandemic to improve patient convenience and reduce the out-patient burden on the hospitals.

14.
Org Biomol Chem ; 19(27): 6160-6169, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34190304

RESUMO

Chemo-, regio- and diastereoselective coupling reactions of indole with imide derivatives leading to unique heterocyclic systems are demonstrated. Acid-induced 3-position coupling reactions of indole with cyclic imide derived lactamols followed by acid promoted 2-position cyclizations with the corresponding aldehydes are described to obtain the indolizinoindolones and benzoindolizinoindolones. Base induced 2-position coupling reactions of N-tosylindole with N-(2-iodoethyl)imides and the subsequent cyclizations provide indolylepoxypyrrolooxazole, indolylpyrrolooxazolone and indolyloxazoloisoindolone. Reductive cleavage of indolyloxazoloisoindolone to the corresponding alcohol followed by mesylation and base promoted N-cyclization affords the in situ air-oxidized pentacyclic product hydroxyisoindolopyrazinoindolone. A regioisomeric structural revision of the natural product from 1,2,5,6,7,11c-hexahydro-3H-indolizino[7,8-b]indol-3-one to 1,2,5,6,11,11b-hexahydro-3H-indolizino(8,7-b)indol-3-one is also reported in the present studies focussed on the methodologies for heterocyclic synthesis.

15.
J Pharm Sci ; 110(3): 1077-1082, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33340533

RESUMO

Developing ultra-high concentration biotherapeutics drug products can be challenging due to increased viscosity, processing, and stability issues. Excipients used to alleviate these concerns are traditionally evaluated at lower protein concentrations. This study investigates whether classically known modulators of stability and viscosity at low (<50 mg/mL) to high (>50 - 150 mg/mL) protein concentrations are beneficial in ultra-high (>150 mg/mL) concentration protein formulations and drug products. This study evaluates the effect of arginine monohydrochloride, proline, and lysine monohydrochloride on viscosity and concentratability at different high and ultra-high protein concentrations using a monoclonal antibody, mAbN, formulation as a candidate protein system. The effect of excipients on the viscosity and concentratability (rate and extent) was different at high versus ultra-high protein concentrations. These results highlight that classical excipients in literature known to modulate protein interactions at low protein concentrations and reduce viscosity at high protein concentrations may need to be evaluated at target protein concentrations in a product-specific manner while developing ultra-high concentration biologics drug products.


Assuntos
Produtos Biológicos , Excipientes , Anticorpos Monoclonais , Desenvolvimento de Medicamentos , Estabilidade de Medicamentos , Viscosidade
16.
J Pharm Sci ; 110(3): 1103-1110, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33137372

RESUMO

Formulation of protein-based therapeutics employ advanced formulation and analytical technologies for screening various parameters such as buffer, pH, and excipients. At a molecular level, physico-chemical properties of a protein formulation depend on self-interaction between protein molecules, protein-solvent and protein-excipient interactions. This work describes a novel in silico approach, SILCS-Biologics, for structure-based modeling of protein formulations. SILCS Biologics is based on the Site-Identification by Ligand Competitive Saturation (SILCS) technology and enables modeling of interactions among different components of a formulation at an atomistic level while accounting for protein flexibility. It predicts potential hotspot regions on the protein surface for protein-protein and protein-excipient interactions. Here we apply SILCS-Biologics on a Fab domain of a monoclonal antibody (mAbN) to model Fab-Fab interactions and interactions with three amino acid excipients, namely, arginine HCl, proline and lysine HCl. Experiments on 100 mg/ml formulations of mAbN showed that arginine increased, lysine reduced, and proline did not impact viscosity. We use SILCS-Biologics modeling to explore a structure-based hypothesis for the viscosity modulating effect of these excipients. Current efforts are aimed at further validation of this novel computational framework and expanding the scope to model full mAb and other protein therapeutics.


Assuntos
Aminoácidos , Proteínas , Simulação por Computador , Ligantes
18.
Egypt Heart J ; 72(1): 34, 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32642857

RESUMO

BACKGROUND: Portsmann and co. performed the first PDA device closure in 1967. The technique and the devices used have evolved since then and are the first choice in managing anatomically feasible patent ductus arteriosus (PDA) for the last 20 years. Though catheter-based closure of PDA is generally a simple procedure, there are instances when the interventionist faces challenges, especially in smaller children, with syndromic features and venous anomalies even when defects are small and pulmonary artery pressures are normal. Although the femoral vein is the relatively risk-free standard access, internal jugular vein, femoral artery, and transhepatic IVC can be used to close the PDA in different anomalies. The rare venous anomaly of infrahepatic interruption of the IVC with azygous continuation poses technical challenges when percutaneous closure of PDA was attempted through the standard femoral access. CASE PRESENTATION: We report a rare case of PDA device closure in a syndromic child with a short neck having interrupted IVC via femoral-azygous venous approach. CONCLUSION: Knowledge of the IVC course and its anomalies should be known to the operator before the percutaneous closure of PDA. Although other approaches are available, femoral vein approach can be used in case of interrupted IVC for percutaneous closure of PDA.

19.
J Indian Assoc Pediatr Surg ; 25(2): 115-117, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32139993

RESUMO

Splenogonadal fusion (SGF) is a rare congenital anomaly. Less than 200 cases of SGF have been documented till date. We present a case of 14-year-old male patient with swelling in the left scrotum for 3 years. Left orchidectomy was done. Histopathology showed ectopic splenic tissue surrounding testicular parenchyma suggestive of SGF. This rare congenital malformation may occur due to the proximity of developing gonad and spleen, resulting in abnormal connection between them during gestation. SGF presents a diagnostic challenge preoperatively; however, recent imaging methods can aid with the diagnosis. SGF as a rare cause of testicular swelling should be kept in mind and evaluated to avoid unnecessary orchidectomy.

20.
Inorg Chem ; 59(3): 1996-2004, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31922740

RESUMO

Highly durable and earth-abundant bifunctional catalysts with low cell voltage are desirable for alkaline overall water splitting in the industrial fields. Herein, a novel carbon-based CoP hybrid with spatial compartmentalization of CoP nanoparticles (NPs) in P-doped dual carbon shells is achieved via a cheap Co-glycerate-template strategy. Benefitted from the uniform atomic blending of Co2+ ions in the Co-glycerate precursors, CoP NPs in situ formed in the confined space with NaH2PO2 as phosphorus source during the annealing process; meanwhile, glycerate suffered carbonization and transformed into P-doped dual carbon shells during the annealing process, including interior thin carbon coating, closely encircled CoP NP, and peripheral hollow carbon sphere loading a lot of CoP NPs. Not only does spatial compartmentalization of CoP NPs avoid the aggregation and expose more active sites but also P-doped dual carbon shells improve the conductivity and durability of the catalyst. As expected, the optimized hybrid exhibits outstanding electrocatalytic activities in alkaline media, such as hydrogen evolution reaction (HER) overpotential of 101 mV, oxygen evolution reaction (OER) overpotential of 280 mV, and a low cell voltage of 1.66 V to deliver a current density of 10 mA cm-2. Moreover, durability and stability are greatly improved under harsh electrochemical conditions. The current strategy shades new insight into the development of carbon-based transition metal phosphides (TMP) catalysts for electrocatalysis applications.

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