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1.
Eur J Pharm Biopharm ; : 114295, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38636881

RESUMO

Postproduction handling of drug products during preparation or clinical use may affect the structure and efficacy of the drug and perhaps remain unnoticed. Since chemical modifications can impact the product's structure, stability, and biological activity, this study investigates the impact of elevated temperature and subtle shift in pH on the drug product post-dilution in saline. The mAb sample diluted in saline for administration was stressed at elevated temperature and slightly acidic pH condition. Extended stability studies were performed and monitored for size and charge heterogeneity. Size heterogeneity shows no significant changes, whereas charge heterogeneity shows an increase in basic variants and a reduction in main species. Further, basic variants were isolated and characterized to identify the type and site of chemical modification. Intact mass analysis and peptide mapping identify that the basic variants were attributed majorly to the isomerization of HC Asp102 into iso-Asp or its succinimide intermediate. Four basic variants were found to exhibit similar structural properties as the main and control samples. However, basic variants showed reduced binding affinity to HER2 receptor, while there was no significant difference in FcRn binding. The results indicate that modification in the HC Asp102, which is present in the CDR, affects antigen binding and thus can influence the potency of the drug product. Hence, with the conventional stability studies required to license the drug product, including in-use or extended stability studies to mimic the postproduction handling would be desirable.

2.
Exp Appl Acarol ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38448756

RESUMO

To study the acaricide resistance status and possible mechanisms of action in conferring resistance to commonly used acaricides (deltamethrin and coumaphos), Hyalomma anatolicum ticks were collected from 6 dairy farms of Hisar and Charkhi Dadri districts of Haryana. By using standard larval packet test, H. anatolicum tick larvae of Charkhi Dadri isolates were found to be susceptible (100% mortality) to both the acaricides. Level-I resistance against coumaphos was recorded from four isolates, whereas, level-II was observed in only one isolate, collected from Hisar. One isolates (Kaimri) from Hisar also showed level-I resistance against deltamethrin. Biochemically, the ticks having higher values of resistance factor (RF) against coumaphos were found to possess increased enzymatic activity of α-esterase, ß-esterase, glutathione-S-transferase (GST) and mono-oxygenase enzymes, whereas, the monoamine oxidase did not show any constant trend. However, the RF showed a statistical significant correlation with GST only. Native PAGE analysis of H. anatolicum ticks revealed the presence of nine types of esterases (EST-1 h to EST-9 h) by using napthyl acetate as substrate. In the inhibitory assay, esterases were found to be inhibited by PMSF, indicating the presence of serine residue at catalytic triad. The partial cds of carboxylesterase and domain II of sodium channel genes were sequenced to determine any proposed mutations in resistant isolates of H. anatolicum ticks, however, no mutations were observed in either gene, indicating that increased expression of detoxification enzymes as a possible mechanism for resistance development, in the current study.

3.
J Chromatogr A ; 1721: 464806, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38518514

RESUMO

Monoclonal antibodies (mAbs) continue to dominate the biopharmaceutical industry. Certain mAbs are prone to fragmentation and clipping and in these cases, adequate removal of these species is critical during manufacturing. Fragments can be generated during fermentation, purification, storage, formulation, and administration. Their addition to the acidic charge-variant of the purified mAb has been reported to decrease stability and potency of the final product. However, contrary to mAb aggregation, manufacturers have not given much attention to removal of fragments and clipped species and as a result most conventional mAb platforms offer at best limited capabilities for their removal. In this study, we propose a novel purification platform that uses multimodal chromatography and achieves complete removal of a range of mAb fragments and clipped products (25-120 kDa). The utility of the platform has been successfully demonstrated for 2 IgG1s and 2 IgG4s. Further, adequate removal of the various host cell impurities such as host cell proteins (<10 ppm) and host cell DNA (<5 ppb) has been achieved. Finally, the platform was able to deliver adequate removal of high molecular weight impurities (<1 %) and a 30 % clearance of the acidic charge variant. The proposed single step has been shown to deliver what the polishing chromatography and intermediate purification chromatography steps deliver in a traditional mAb platform.


Assuntos
Anticorpos Monoclonais , Cromatografia , Cricetinae , Animais , Peso Molecular , Comércio , Células CHO , Cricetulus
4.
J Allergy Clin Immunol ; 153(4): 924-938, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38373475

RESUMO

Evolution has created complex mechanisms to sense environmental danger and protect tissues, with the nervous and immune systems playing pivotal roles. These systems work together, coordinating local and systemic reflexes to restore homeostasis in response to tissue injury and infection. By sharing receptors and ligands, they influence the pathogenesis of various diseases. Recently, a less-explored aspect of neuroimmune communication has emerged: the release of neuropeptides from immune cells and cytokines/chemokines from sensory neurons. This article reviews evidence of this unique neuroimmune interplay and its impact on the development of allergy, inflammation, itch, and pain. We highlight the effects of this neuroimmune signaling on vital processes such as host defense, tissue repair, and inflammation resolution, providing avenues for exploration of the underlying mechanisms and therapeutic potential of this signaling.


Assuntos
Citocinas , Células Receptoras Sensoriais , Humanos , Transdução de Sinais , Inflamação , Neuroimunomodulação/fisiologia
5.
Curr Hypertens Rev ; 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38192137

RESUMO

BACKGROUND: Declined kidney function associated with hypertension is a danger for cognitive deficits, dementia, and brain injury. Cognitive decline and vascular dementia (VaD) are serious public health concerns, which highlights the urgent need for study on the risk factors for cognitive decline. Cysteinyl leukotriene (CysLT1) receptors are concerned with regulating cognition, motivation, inflammatory processes, and neurogenesis. OBJECTIVE: This research aims to examine the consequence of montelukast (specific CysLT1 antagonist) in renovascular hypertension 2-kidney-1-clip-2K1C model-triggered VaD in experimental animals. METHODS: 2K1C tactics were made to prompt renovascular hypertension in mature male rats. Morris water maze was employed to measure cognition. Mean arterial pressure (MAP), serum nitrite levels, aortic superoxide content, vascular endothelial activity, brain's oxidative stress (diminished glutathione, raised lipid peroxides), inflammatory markers (IL-10, IL-6, TNF-α), cholinergic activity (raised acetylcholinesterase), and cerebral injury (staining of 2, 3, 5- triphenylterazolium chloride) were also examined. RESULTS: Montelukast in doses of 5.0 and 10.0 mg kg-1 was used intraperitoneally as the treatment drug. Along with cognitive deficits, 2K1C-operated rats showed elevated MAP, endothelial dysfunction, brain oxidative stress, inflammation, and cerebral damage with diminished serum nitrite/nitrate. Montelukast therapy significantly and dose-dependently mitigated the 2K1Chypertension-provoked impaired behaviors, biochemistry, endothelial functions, and cerebral infarction. CONCLUSION: The 2K1C tactic caused renovascular hypertension and associated VaD, which was mitigated via targeted regulation of CysLT1 receptors by montelukast administration. Therefore, montelukast may be taken into consideration for the evaluation of its complete potential in renovascular-hypertension-induced VaD.

6.
Pestic Biochem Physiol ; 196: 105634, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37945265

RESUMO

Chemical control of tick infestation on dairy farms in India strongly relies upon the use of synthetic pyrethroids (deltamethrin) and organophosphate (coumaphos) drugs. Therefore, the present manuscript aims to investigate the resistance status of Rhipicephalus microplus ticks against these acaricides. Fully engorged adult R. microplus ticks were randomly collected from 8 dairy farms in North India and evaluated for acaricide resistance by using the Larval Packet Test (LPT). Of these, ticks collected from one and three farms showed the emergence of Level I acaricide resistance against deltamethrin and coumaphos, respectively. Significant positive correlations were found in the enzymatic activity (α-esterase, ß-esterase, glutathione-S-transferase, and mono-oxygenase) of R. microplus tick resistant against coumaphos. Native electrophoretogram analysis showed six different types of esterase activity in R. microplus (EST-1b to EST-6b), and EST-5b activity was more predominantly expressed in resistant ticks. Further, inhibitor studies using various esterase inhibitors suggested that EST-5b is a putative acetylcholine-esterase (AchE), and increased expression of one of the AchE might be responsible for the emergence of acaricide resistance. Further, no mutations were detected in the carboxylesterase (G1120A) and domain II S4-5 linker region (C190A) of the sodium channel genes of resistant R. microplus ticks, indicating that increased expression of detoxification enzymes was the probable mechanism for the development of acaricide resistance in the resistant ticks.


Assuntos
Acaricidas , Piretrinas , Rhipicephalus , Animais , Rhipicephalus/genética , Acaricidas/farmacologia , Cumafos , Organofosfatos/farmacologia , Piretrinas/farmacologia , Esterases/genética , Esterases/metabolismo , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo
7.
Org Biomol Chem ; 21(40): 8136-8140, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37772462

RESUMO

The widespread presence of bicyclo[1.1.1]pentane (BCP) and sulfur motifs in pharmaceutical compounds underscores the significance of synthesizing suitably functionalized BCP thioethers. In response, we have developed a metal-free and photocatalyst-free strategy that harnesses visible light-induced radical cascades. This approach culminates in the synthesis of essential thio-BCP derivatives, which serve as crucial precursors for the formation of the corresponding sulfoxides, sulfones, and sulfoximines. Importantly, this methodology exhibits potential for large-scale applications, displaying commendable tolerance towards various functional groups while operating under mild reaction conditions.

8.
Sci Rep ; 13(1): 7909, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37193725

RESUMO

The inherent nonlinear magnetization dynamics in spintronic devices make them suitable candidates for neuromorphic hardware. Among spintronic devices, spin torque oscillators such as spin transfer torque oscillators and spin Hall oscillators have shown the capability to perform recognition tasks. In this paper, with the help of micromagnetic simulations, we model and demonstrate that the magnetization dynamics of a single spin Hall oscillator can be nonlinearly transformed by harnessing input pulse streams and can be utilized for classification tasks. The spin Hall oscillator utilizes the microwave spectral characteristics of its magnetization dynamics for processing a binary data input. The spectral change due to the nonlinear magnetization dynamics assists in real-time feature extraction and classification of 4-binary digit input patterns. The performance was tested for the classification of the standard MNIST handwritten digit data set and achieved an accuracy of 83.1% in a simple linear regression model. Our results suggest that modulating time-driven input data can generate diverse magnetization dynamics in the spin Hall oscillator that can be suitable for temporal or sequential information processing.

9.
Cureus ; 15(3): e36569, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37095793

RESUMO

OBJECTIVE: To study the five mutations commonly prevalent in North India, i.e., IVS-I-5 (G→C), 619 bp deletion, IVS-I-1 (G→T), codon 41/42 (-TTCT), and codon 8/9 (+G), in the beta thalassemia (ß-thalassemia) major children. The specific ß-thalassemia mutations of different haplotype patterns of the ß-globin gene cluster will also be determined. METHODS: A total of 125 children diagnosed with ß-thalassemia major visiting the Department of Pediatrics of King George's Medical University were involved in the study. As per the QIAamp (Qiagen, Hilden, Germany) manufacturer guidelines, genomic DNA was isolated from whole blood. To identify the haplotype pattern within the ß-globin gene cluster, the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used. The respective restriction endonucleases used were Hind III/GƔ, Hinc II/Ψß, Hinf I/ß, Ava II/ß, and BamHI for the haplotype analysis in the ß-globin pattern of descent of a set of linked alleles occurring on the same chromosome. RESULTS: Among the five common mutations, 73 patients had IVS-I-5 (G→C), 28 patients had 619 bp deletion, 17 patients had IVS-I-1 (G→T), five patients had Cd 41/42 (-TTCT), and two patients had Cd 8/9 (+G) mutations. Fifteen haplotypes (haplotypes 1-15) were identified in 125 ß-thalassemia major children. Among the five haplotypes observed in the IVS-I-5 (G→C) mutation, the H1 haplotype was most predominant with a frequency of 27.2%, followed by the H2, H4, H3, and H10 haplotypes in the given population. In 619 bp deletion, IVS-I-1 (G→T), codon 41/42, and codon 8/9, haplotype H9, H12, H11, and H5 were seen, respectively. CONCLUSION: ß-thalassemia was found to be the most common in the northern province of Uttar Pradesh. The linkage of ß-globin gene haplotypes with ß-thalassemia mutations was explored in the northern province of Uttar Pradesh. The population of different natives is being mixed up due to migration and industrialization. These were some reasons for the occurrence of haplotypic heterogeneity. This haplotype heterogeneity was correlated with the origin of these mutations found to be unlike the origin of common ones from different provinces.

10.
Mol Biochem Parasitol ; 254: 111562, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37084956

RESUMO

Current chemotherapy against the Surra organism, Trypanosoma evansi has several limitations in terms of efficacy, toxicity, availability and emerging resistance. These reasons make the search of new chemo-preventive and chemo-therapeutic agent with high potency and low toxicity. Alkaloid phyto-molecules, berberine has shown promising anti-kinetoplastid activity against T. cruzi, T. congolense, T. brucei, Leishmania donovani and L. tropica. However, till date, there is no investigation of therapeutic efficacy of berberine chloride (BC) against T. evansi. The IC50 value of BC for growth inhibition of T. evansi at 24 h of culture was calculated as 12.15 µM. The specific selectivity index (SSI) of BC was calculated as 19.01 and 10.43 against Vero cell line and Equine PBMC's, respectively. Thirteen drug target genes affecting various metabolic pathways were studied to investigate the mode of trypanocidal action of BC. In transcript analysis, the mRNA expression of arginine kinase 1 remained refractory to exposure with BC, which provides metabolic plasticity in adverse environmental conditions. In contrary, rest all the drug target gene were down-regulated, which indicates that drug severely affect DNA replication, cell proliferation, energy homeostasis, redox homeostasis and calcium homeostasis of T. evansi, leading to the death of parasite in low concentrations. It is the first attempt to investigate in vitro anti-trypanosomal activity of BC against T. evansi. These data imply that phytochemicals as alternative strategies can be explored in the future as an alternative treatment for Surra in animal.


Assuntos
Berberina , Doença de Chagas , Trypanosoma , Tripanossomíase , Animais , Cavalos , Berberina/farmacologia , Berberina/metabolismo , Berberina/uso terapêutico , Cloretos/metabolismo , Cloretos/uso terapêutico , Leucócitos Mononucleares , Trypanosoma/genética , Trypanosoma/metabolismo , Tripanossomíase/tratamento farmacológico
11.
Cureus ; 15(4): e37283, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37038380

RESUMO

Introduction High systolic blood pressure (SBP) and raised plasma glucose are major attributable and preventable causes of death worldwide. The objective of this study was to estimate the control rates and identify determinants of control of hypertension and diabetes among adults. Methods A longitudinal follow-up study was conducted among all the adults registered at the noncommunicable disease (NCD) clinics under the national program at two primary health centers in Faridabad, Haryana. Data were collected every month from the individual booklet generated for registered adults. Two monthly visits in three months and four in six months were considered adequate follow-ups at the NCD clinic. Results In the study, 495 (82.2%) adults had hypertension, and 242 (40.2%) had diabetes. The control rates at the third and sixth months were 37.1% (95% confidence interval (CI): 31.4-42.7) and 53.6% (95% CI: 43.4-59.8) among hypertensives and 28.7% (95% CI: 21.7-35.7) and 35.9% (95% CI: 27.5-44.4) among diabetics. Among hypertensives, six-month control status was associated with adequate follow-up at the NCD clinic (adjusted odds ratio (AOR) 2.3; 95% CI: 1.4-4.0; p-value: 0.002), male sex (AOR 0.5; 95% CI: 0.3-0.9; p-value: 0.02) and high SBP (AOR 0.5; 95% CI: 0.3-0.9; p-value: 0.017). Conclusions Control status was achieved in half of the adults with hypertension and one-third of adults with diabetes after six months of regular follow-up. Adequate follow-up at the NCD clinic, male sex, and raised SBP emerged as determinants of control among hypertensives.

12.
Org Lett ; 25(16): 2857-2862, 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37057970

RESUMO

Here, we report a facile and efficient method for the difluoroalkylation of vinyl cyclopropanes (VCPs) using visible-light organophotoredox catalysis. This strategy exploits the interplay of α-amino alkyl radical-mediated halogen-atom transfer (XAT) reaction. The broad substrate scope, excellent functional group compatibility, operational simplicity, inexpensive CF2 precursors, and high efficiency make this protocol promising for the cost-efficient synthesis of allylic difluoroalkylated derivatives.

13.
IEEE Trans Neural Netw Learn Syst ; 34(9): 6656-6662, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34874871

RESUMO

Recently introduced deep reinforcement learning (DRL) techniques in discrete-time have resulted in significant advances in online games, robotics, and so on. Inspired from recent developments, we have proposed an approach referred to as Quantile Critic with Spiking Actor and Normalized Ensemble (QC_SANE) for continuous control problems, which uses quantile loss to train critic and a spiking neural network (NN) to train an ensemble of actors. The NN does an internal normalization using a scaled exponential linear unit (SELU) activation function and ensures robustness. The empirical study on multijoint dynamics with contact (MuJoCo)-based environments shows improved training and test results than the state-of-the-art approach: population coded spiking actor network (PopSAN).

14.
Sci Rep ; 12(1): 18903, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344808

RESUMO

Biofilms are assemblages of sessile microorganisms that form an extracellular matrix around themselves and mediate attachment to surfaces. The major component of the extracellular matrix of Uropathogenic E. coli and other Enterobacteriaceae are curli fibers, making biofilms robust and resistant to antimicrobials. It is therefore imperative to screen antibiofilm compounds that can impair biofilm formation. In the present study, we investigated the curli-dependent antibiofilm activity of caffeine against UPEC strain CFT073 and commensal strain E. coli K-12MG1655.Caffeine significantly reduced the biofilm formation of both UPEC and E. coli K-12 by 86.58% and 91.80% respectively at 48 mM caffeine as determined by Crystal Violet assay. These results were further confirmed by fluorescence microscopy and Scanning Electron Microscope (SEM). Caffeine significantly reduced the cytotoxicity and survivability of UPEC. Molecular docking analysis revealed a strong interaction between caffeine and curli regulator protein (Csg D) of E. coli. The qRT-PCR data also showed significant downregulation in the expression of CsgBA and the CsgDEFG operon at both 24 mM and 48 mM caffeine. The findings revealed that caffeine could inhibit E. coli biofilm formation by regulating curli assembly and thus may be used as an alternative therapeutic strategy for the treatment of chronic E. coli biofilm-related infections.


Assuntos
Biofilmes , Cafeína , Escherichia coli Uropatogênica , Biofilmes/efeitos dos fármacos , Cafeína/farmacologia , Fímbrias Bacterianas/metabolismo , Simulação de Acoplamento Molecular , Escherichia coli Uropatogênica/efeitos dos fármacos
15.
Front Physiol ; 13: 952709, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36246115

RESUMO

Cancer is one of the top causes of death globally. Recently, microarray gene expression data has been used to aid in cancer's effective and early detection. The use of DNA microarray technology to uncover information from the expression levels of thousands of genes has enormous promise. The DNA microarray technique can determine the levels of thousands of genes simultaneously in a single experiment. The analysis of gene expression is critical in many disciplines of biological study to obtain the necessary information. This study analyses all the research studies focused on optimizing gene selection for cancer detection using artificial intelligence. One of the most challenging issues is figuring out how to extract meaningful information from massive databases. Deep Learning architectures have performed efficiently in numerous sectors and are used to diagnose many other chronic diseases and to assist physicians in making medical decisions. In this study, we have evaluated the results of different optimizers on a RNA sequence dataset. The Deep learning algorithm proposed in the study classifies five different forms of cancer, including kidney renal clear cell carcinoma (KIRC), Breast Invasive Carcinoma (BRCA), lung adenocarcinoma (LUAD), Prostate Adenocarcinoma (PRAD) and Colon Adenocarcinoma (COAD). The performance of different optimizers like Stochastic gradient descent (SGD), Root Mean Squared Propagation (RMSProp), Adaptive Gradient Optimizer (AdaGrad), and Adaptive Momentum (AdaM). The experimental results gathered on the dataset affirm that AdaGrad and Adam. Also, the performance analysis has been done using different learning rates and decay rates. This study discusses current advancements in deep learning-based gene expression data analysis using optimized feature selection methods.

16.
Mol Pharm ; 19(11): 3770-3783, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36173709

RESUMO

We have developed a multi-level virtual screening protocol to identify lead molecules from the FDA inactives database that can inhibit insulin aggregation. The method is based on the presence of structural and interaction specificity in non-native aggregation pathway protein-protein interactions. Some key challenges specific to the present problem, when compared with native protein association, include structural heterogeneity of the protein species involved, multiple association pathways, and relatively higher probability of conformational rearrangement of the association complex. In this multi-step method, the inactives database was first screened using the dominant pharmacophore features of previously identified molecules shown to significantly inhibit insulin aggregation nucleation by binding to its aggregation-prone conformers. We then performed ensemble docking of several low-energy ligand conformations on these aggregation-prone conformers followed by molecular dynamics simulations and binding affinity calculations on a subset of docked complexes to identify a final set of five potential lead molecules to inhibit insulin aggregation nucleation. Their effect on aggregation inhibition was extensively investigated by incubating insulin under aggregation-prone aqueous buffer conditions (low pH, high temperature). Aggregation kinetics were characterized using size exclusion chromatography and Thioflavin T fluorescence assay, and the secondary structure was determined using circular dichroism spectroscopy. Riboflavin provided the best aggregation inhibition, with 85% native monomer retention after 48 h incubation under aggregation-prone conditions, whereas the no-ligand formulation showed complete monomer loss after 36 h. Further, insulin incubated with two of the screened inactives (aspartame, riboflavin) had the characteristic α-helical dip in CD spectra, while the no-ligand formulation showed a change to ß-sheet rich conformations.


Assuntos
Ensaios de Triagem em Larga Escala , Insulina , Insulina/química , Ligantes , Estrutura Secundária de Proteína , Insulina Regular Humana , Riboflavina , Dicroísmo Circular
17.
Int J Imaging Syst Technol ; 32(5): 1464-1480, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35941931

RESUMO

The syndrome called COVID-19 which was firstly spread in Wuhan, China has already been declared a globally "Pandemic." To stymie the further spread of the virus at an early stage, detection needs to be done. Artificial Intelligence-based deep learning models have gained much popularity in the detection of many diseases within the confines of biomedical sciences. In this paper, a deep neural network-based "LiteCovidNet" model is proposed that detects COVID-19 cases as the binary class (COVID-19, Normal) and the multi-class (COVID-19, Normal, Pneumonia) bifurcated based on chest X-ray images of the infected persons. An accuracy of 100% and 98.82% is achieved for binary and multi-class classification respectively which is competitive performance as compared to the other recent related studies. Hence, our methodology can be used by health professionals to validate the detection of COVID-19 infected patients at an early stage with convenient cost and better accuracy.

18.
Eur J Pharm Biopharm ; 178: 131-139, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35961566

RESUMO

Non-enzymatic hinge fragmentation of monoclonal antibodies (mAb) is considered a critical quality attribute since it changes the primary sequence of the proteins, thereby leading to structural changes which can affect stability, function, and efficacy. While peptide bonds are exceptionally stable under physiological conditions, reactive side chains of a few residues, the flexibility of the backbone, and physicochemical parameters such as pH, temperature, and the reaction of radicals and metal ions can promote the cleavage of peptide bonds. In this study, the relative extent and rate of fragmentation are compared with respect to the presence of several different factors (including hydrogen peroxide, metal ion, and temperature) as measured by size exclusion chromatography. A kinetic model of monomer degradation as a function of time (mAb only) is created. In the presence of either H2O2 or Cu2+, or both, the reaction kinetics follow different orders depending on the reaction conditions. The half-life for peptide bond cleavage of the mAb hinge region was 385 days at 40 °C and decreases to 250, 48, and 45 days in the presence of H2O2, Cu2+, and a combination of H2O2 and Cu2+, respectively. A temperature dependence of peptide bond cleavage at 35 °C, 40 °C, 45 °C, and 50 °C showed Arrhenius behavior with an apparent activation energy of 76.9 ± 16.4 kJ/mol. The reaction rates obtained from the Arrhenius equation were then extrapolated to predict fragmentation rates under real storage conditions (e.g., at 2-8 °C). We demonstrate that trace levels of impurities including peroxide left after surface sterilization or degradation of non-ionic surfactants or metal ions from the buffer components can significantly affect the stability of a mAb.


Assuntos
Anticorpos Monoclonais , Peróxido de Hidrogênio , Anticorpos Monoclonais/química , Cromatografia em Gel , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Cinética , Peptídeos , Temperatura
19.
Parasitol Int ; 91: 102632, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35870741

RESUMO

The kinetoplastid protozoan parasite, Trypanosoma evansi causes a fatal disease condition known as Surra in equines throughout the globe. Disease condition being acute in nature, entrust a huge economic and health impact on the equine industry. Till date, quinapyramine methyl sulphate (QPS) is the first line of treatment and a panacea for the T. evansi infection in equines. Still after the >70 years of its discovery, there is no clue about the mode of action of QPS in T. evansi. The establishment of in vitro cultivation of T. evansi in HMI-9 media has provided opportunity to study the alteration in mRNA expression of parasite on exposure to the drug. With this research gap, the present study aimed to investigate the relative mRNA expression of 13 important drug target genes to elucidate the anti-trypanosomal activity of QPS against T. evansi. The IC50 of QPS against a pony isolate of T. evansi was determined as 276.4 nM(147.21 ng/ mL) in the growth inhibitory assay. The in vitro cultured T. evansi population were further exposed to IC50 of QPS and their relative mRNA expression was studied at 12 h, 24 h and 48 h interval.The mRNA expression of several genes such as hexokinase, trypanothione reductase, aurora kinase, oligopeptidase B and ribonucleotide reductase II were found refractory (non-significant, p > 0.1234) to the exposure of QPS. Significant up-regulation of trans-sialidase (p < 0.0001), ESAG8 (p < 0.0021), ribonucleotide reductase I (p < 0.0001), ornithine decarboxylase (p < 0.0001), topoisomerase II (p < 0.0021) and casein kinase I (p < 0.0021) were recorded after exposure with QPS. The arginine kinase 1 and calcium ATPase I showed highly significant (p < 0.0001) down-regulation in the drug kinetics. Therefore, the arginine kinase 1 and calcium ATPase I can be explored further to elucidate the trypanocidal activity of QPS. The preliminary data generated provide the potential of arginine kinase 1 and calcium ATPase I mRNA mediated pathway of trypanocidal action of QPS. Further, transcriptomics approach is required to investigate the possible mechanism of action of drugs at molecular level against the targeted organism.


Assuntos
Arginina Quinase , Ribonucleotídeo Redutases , Tripanossomicidas , Trypanosoma , Tripanossomíase , Animais , Arginina Quinase/metabolismo , Arginina Quinase/uso terapêutico , Expressão Gênica , Cavalos , Compostos de Quinolínio , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ribonucleotídeo Redutases/metabolismo , Ribonucleotídeo Redutases/uso terapêutico , Ésteres do Ácido Sulfúrico , Tripanossomicidas/metabolismo , Tripanossomíase/tratamento farmacológico , Tripanossomíase/veterinária
20.
Trop Anim Health Prod ; 54(4): 240, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35869164

RESUMO

High cytotoxicity and increasing resistance reports of existing chemotherapeutic agents against T. evansi have raised the demand for novel, potent, and high therapeutic index molecules for the treatment of surra in animals. In this regard, repurposing approach of drug discovery has provided an opportunity to explore the therapeutic potential of existing drugs against new organism. With this objective, the macrocyclic lactone representative, ivermectin, has been investigated for the efficacy against T. evansi in the axenic culture medium. To elucidate the potential target of ivermectin in T. evansi, mRNA expression profile of 13 important drug target genes has been studied at 12, 24, and 48 h interval. In the in vitro growth inhibition assay, ivermectin inhibited T. evansi growth and multiplication significantly (p < 0.001) with IC50 values of 13.82 µM, indicating potent trypanocidal activity. Cytotoxicity assays on equine peripheral blood mononuclear cells (PBMCs) and Vero cell line showed that ivermectin affected the viability of cells with a half-maximal cytotoxic concentration (CC50) at 17.48 and 22.05 µM, respectively. Data generated showed there was significant down-regulation of hexokinase (p < 0.001), ESAG8 (p < 0.001), aurora kinase (p < 0.001), casein kinase 1 (p < 0.001), topoisomerase II (p < 0.001), calcium ATPase 1 (p < 0.001), ribonucleotide reductase I (p < 0.05), and ornithine decarboxylase (p < 0.01). The mRNA expression of oligopeptidase B remains refractory to the exposure of the ivermectin. The arginine kinase 1 and ribonucleotide reductase II showed up-regulation on treatment with ivermectin. The ivermectin was found to affect glycolytic pathways, ATP-dependent calcium ATPase, cellular kinases, and other pathway involved in proliferation and maintenance of internal homeostasis of T. evansi. These data imply that intervention with alternate strategies like nano-formulation, nano-carriers, and nano-delivery or identification of ivermectin homologs with low cytotoxicity and high bioavailability can be explored in the future as an alternate treatment for surra in animals.


Assuntos
Doenças dos Cavalos , Ribonucleotídeo Redutases , Trypanosoma , Tripanossomíase , Animais , Cavalos , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Leucócitos Mononucleares/metabolismo , Redes e Vias Metabólicas , RNA Mensageiro/metabolismo , Ribonucleotídeo Redutases/metabolismo , Ribonucleotídeo Redutases/farmacologia , Tripanossomíase/tratamento farmacológico , Tripanossomíase/veterinária
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