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1.
Nature ; 603(7901): 439-444, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35296845

RESUMEN

The introduction of molecular complexity in an atom- and step-efficient manner remains an outstanding goal in modern synthetic chemistry. Artificial biosynthetic pathways are uniquely able to address this challenge by using enzymes to carry out multiple synthetic steps simultaneously or in a one-pot sequence1-3. Conducting biosynthesis ex vivo further broadens its applicability by avoiding cross-talk with cellular metabolism and enabling the redesign of key biosynthetic pathways through the use of non-natural cofactors and synthetic reagents4,5. Here we describe the discovery and construction of an enzymatic cascade to MK-1454, a highly potent stimulator of interferon genes (STING) activator under study as an immuno-oncology therapeutic6,7 (ClinicalTrials.gov study NCT04220866 ). From two non-natural nucleotide monothiophosphates, MK-1454 is assembled diastereoselectively in a one-pot cascade, in which two thiotriphosphate nucleotides are simultaneously generated biocatalytically, followed by coupling and cyclization catalysed by an engineered animal cyclic guanosine-adenosine synthase (cGAS). For the thiotriphosphate synthesis, three kinase enzymes were engineered to develop a non-natural cofactor recycling system in which one thiotriphosphate serves as a cofactor in its own synthesis. This study demonstrates the substantial capacity that currently exists to use biosynthetic approaches to discover and manufacture complex, non-natural molecules.


Asunto(s)
Guanosina , Nucleotidiltransferasas , Adenosina , Animales , Interferones , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Nucleotidiltransferasas/metabolismo , Transducción de Señal
2.
Proc Natl Acad Sci U S A ; 121(6): e2317408121, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38285953

RESUMEN

Light plays a central role in plant growth and development, providing an energy source and governing various aspects of plant morphology. Previous study showed that many polyadenylated full-length RNA molecules within the nucleus contain unspliced introns (post-transcriptionally spliced introns, PTS introns), which may play a role in rapidly responding to changes in environmental signals. However, the mechanism underlying post-transcriptional regulation during initial light exposure of young, etiolated seedlings remains elusive. In this study, we used FLEP-seq2, a Nanopore-based sequencing technique, to analyze nuclear RNAs in Arabidopsis (Arabidopsis thaliana) seedlings under different light conditions and found numerous light-responsive PTS introns. We also used single-nucleus RNA sequencing (snRNA-seq) to profile transcripts in single nucleus and investigate the distribution of light-responsive PTS introns across distinct cell types. We established that light-induced PTS introns are predominant in mesophyll cells during seedling de-etiolation following exposure of etiolated seedlings to light. We further demonstrated the involvement of the splicing-related factor A. thaliana PROTEIN ARGININE METHYLTRANSFERASE 5 (AtPRMT5), working in concert with the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a critical repressor of light signaling pathways. We showed that these two proteins orchestrate light-induced PTS events in mesophyll cells and facilitate chloroplast development, photosynthesis, and morphogenesis in response to ever-changing light conditions. These findings provide crucial insights into the intricate mechanisms underlying plant acclimation to light at the cell-type level.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteína-Arginina N-Metiltransferasas , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Plantones/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Luz
3.
Proc Natl Acad Sci U S A ; 120(40): e2310881120, 2023 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-37748065

RESUMEN

Cytonuclear disruption may accompany allopolyploid evolution as a consequence of the merger of different nuclear genomes in a cellular environment having only one set of progenitor organellar genomes. One path to reconcile potential cytonuclear mismatch is biased expression for maternal gene duplicates (homoeologs) encoding proteins that target to plastids and/or mitochondria. Assessment of this transcriptional form of cytonuclear coevolution at the level of individual cells or cell types remains unexplored. Using single-cell (sc-) and single-nucleus (sn-) RNAseq data from eight tissues in three allopolyploid species, we characterized cell type-specific variations of cytonuclear coevolutionary homoeologous expression and demonstrated the temporal dynamics of expression patterns across development stages during cotton fiber development. Our results provide unique insights into transcriptional cytonuclear coevolution in plant allopolyploids at the single-cell level.


Asunto(s)
Mitocondrias , Plastidios , Mitocondrias/genética , Diferenciación Celular , Núcleo Solitario
4.
Anal Chem ; 96(26): 10620-10629, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38888085

RESUMEN

Flexible surface-enhanced Raman scattering (SERS) substrates adaptable to strains enable effective sampling from irregular surfaces, but the preparation of highly stable and sensitive flexible SERS substrates is still challenging. This paper reports a method to fabricate a high-performance strain-adaptable SERS substrate by self-assembly of Au nanoparticles (AuNPs) on polydimethylsiloxane (PDMS) nanowrinkles. Nanowrinkles are created on prestrained PDMS slabs by plasma-induced oxidation followed by the release of the prestrain, and self-assembled AuNPs are transferred onto the nanowrinkles to construct the high-performance SERS substrate. The results show that the nanowrinkled structure can improve the surface roughness and enhance the SERS signals by ∼4 times compared to that of the SERS substrate prepared on flat PDMS substrates. The proposed SERS substrate also shows good adaptability to dynamic bending up to ∼|0.4| 1/cm with excellent testing reproducibility. Phenolic pollutants, including aniline and catechol, were quantitatively tested by the SERS substrate. The self-assembled flexible SERS substrate proposed here provides a powerful tool for chemical analysis in the fields of environmental monitoring and food safety inspection.

5.
J Transl Med ; 22(1): 201, 2024 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-38402159

RESUMEN

BACKGROUND: Although the long-term prognosis of papillary thyroid cancer (PTC) is favorable, distant metastasis significantly compromises the prognosis and quality of life for patients with PTC. The Cadherin family plays a pivotal role in tumor metastasis; however, the involvement of Cadherin 4 (CDH4) in the metastatic cascade remains elusive. METHODS: The expression and subcellular localization of CDH4 were determined through immunohistochemistry, immunofluorescence, and western blot analyses. The impact of CDH4 on cell migration, invasion, angiogenesis, and metastasis was assessed using transwell assays, tube formation assays, and animal experiments. Immunoprecipitation assay and mass spectrometry were employed to examine protein associations. The influence of CDH4 on the subcellular expression of ß-catenin and active ß-catenin was investigated via western blotting and immunofluorescence. Protein stability and ubiquitination assay were employed to verify the impact of CDH4 on ß-catenin degradation. Rescue experiments were performed to ensure the significance of CDH4 in regulating nuclear ß-catenin signaling. RESULTS: CDH4 was found to be significantly overexpressed in PTC tissues and predominantly localized in the cytoplasm. Furthermore, the overexpression of CDH4 in tumor tissues is associated with lymph node metastasis in PTC patients. Cytosolic CDH4 promoted the migration, invasion, and lung metastasis of PTC cells and stimulated the angiogenesis and tumorigenesis of PTC; however, this effect could be reversed by Tegavivint, an antagonist of ß-catenin. Mechanistically, cytosolic CDH4 disrupted the interaction between ß-catenin and ß-TrCP1, consequently impeding the ubiquitination process of ß-catenin and activating the nuclear ß-catenin signaling. CONCLUSIONS: CDH4 induces PTC angiogenesis and metastasis via the inhibition of ß-TrCP1-dependent ubiquitination of ß-Catenin.


Asunto(s)
Carcinoma Papilar , Neoplasias de la Tiroides , Animales , Humanos , Angiogénesis , beta Catenina/metabolismo , Cadherinas/metabolismo , Carcinoma Papilar/patología , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Calidad de Vida , Cáncer Papilar Tiroideo/patología , Neoplasias de la Tiroides/patología , Ubiquitinación , Vía de Señalización Wnt
6.
Blood ; 139(22): 3233-3244, 2022 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-35108353

RESUMEN

Fetal and neonatal megakaryocyte progenitors are hyperproliferative compared with adult progenitors and generate a large number of small, low-ploidy megakaryocytes. Historically, these developmental differences have been interpreted as "immaturity." However, more recent studies have demonstrated that the small, low-ploidy fetal and neonatal megakaryocytes have all the characteristics of adult polyploid megakaryocytes, including the presence of granules, a well-developed demarcation membrane system, and proplatelet formation. Thus, rather than immaturity, the features of fetal and neonatal megakaryopoiesis reflect a developmentally unique uncoupling of proliferation, polyploidization, and cytoplasmic maturation, which allows fetuses and neonates to populate their rapidly expanding bone marrow and blood volume. At the molecular level, the features of fetal and neonatal megakaryopoiesis are the result of a complex interplay of developmentally regulated pathways and environmental signals from the different hematopoietic niches. Over the past few years, studies have challenged traditional paradigms about the origin of the megakaryocyte lineage in both fetal and adult life, and the application of single-cell RNA sequencing has led to a better characterization of embryonic, fetal, and adult megakaryocytes. In particular, a growing body of data suggests that at all stages of development, the various functions of megakaryocytes are not fulfilled by the megakaryocyte population as a whole, but rather by distinct megakaryocyte subpopulations with dedicated roles. Finally, recent studies have provided novel insights into the mechanisms underlying developmental disorders of megakaryopoiesis, which either uniquely affect fetuses and neonates or have different clinical presentations in neonatal compared with adult life.


Asunto(s)
Megacariocitos , Trombopoyesis , Adulto , Médula Ósea , Feto , Humanos , Recién Nacido , Células Progenitoras de Megacariocitos , Megacariocitos/metabolismo , Trombopoyesis/genética
7.
Biomacromolecules ; 25(7): 4557-4568, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38899740

RESUMEN

Rheumatoid arthritis (RA) is a complicated chronic disorder of the immune system, featured with severe inflammatory joints, synovium hyperplasia, articular cartilage, and bone damage. In the RA microenvironment, RA-involved cells, overproduced nitric oxide (NO), and pro-inflammatory cytokines are highly interplayed and mutually reinforced, which form a vicious circle and play crucial roles in the formation and progression of RA. To comprehensively break the vicious circle and obtain the maximum benefits, we have developed neutrophil membrane-camouflaged NO scavenging nanoparticles based on an NO-responsive hyaluronic acid derivative for delivery of MTX. These multifunctional nanoparticles (NNO-NPs/MTX), by inheriting the membrane functions of the source cells, possess prolonged circulation and specific localization at the inflamed sites when administrated in the body. Remarkably, NNO-NPs/MTX can neutralize the pro-inflammatory cytokines via the outer membrane receptors, scavenge NO, and be responsively disassociated to release MTX for RA-involved cell regulation and HA for lubrication in the RA sites. In a collagen-induced arthritis mouse model, NNO-NPs/MTX exhibits a significant anti-inflammation effect and effectively alleviates the characteristic RA symptoms such as synovial hyperplasia and cartilage destruction, realizing the synergistic and boosted therapeutic outcome against intractable RA. Thus, NNO-NPs/MTX provides a promising and potent platform to integrately treat RA.


Asunto(s)
Artritis Reumatoide , Ácido Hialurónico , Metotrexato , Óxido Nítrico , Ácido Hialurónico/química , Animales , Artritis Reumatoide/tratamiento farmacológico , Ratones , Metotrexato/farmacología , Metotrexato/administración & dosificación , Metotrexato/química , Óxido Nítrico/metabolismo , Nanopartículas/química , Humanos , Artritis Experimental/tratamiento farmacológico , Artritis Experimental/patología , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas Multifuncionales/química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología
8.
Environ Res ; 245: 118064, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38160965

RESUMEN

Volatile organic compounds (VOCs) significantly affect the air quality in aircraft cabins, consequently affecting passenger health and comfort. Although VOC emission sources and their contributions have been studied extensively, the distribution characteristics of VOCs originating from diverse sources within cabins have received limited attention, and the correlation between VOC sources and concentrations in passenger breathing zones remains largely unexplored. To fill this knowledge gap, the concentration field of VOCs was investigated using a computational fluid dynamics model, and the results were experimentally validated in a typical single-aisle aircraft cabin with seven seat rows. The diffusion characteristics of different VOCs emitted by four typical sources in aircraft cabins (floors, human surfaces, seats, and respiratory sources) were analyzed and compared. The distribution of VOCs emitted by different sources was nonuniform and could be classified into two distinct categories. When the emission intensities of all sources were equal, the average concentration of VOCs emitted from the floor source were considerably lower in the passenger breathing zone (4.01 µg/m³) than those emitted from the human surface, seat, and respiratory sources, which exhibited approximately equal concentrations (6.82, 6.90, and 7.29 µg/m³, respectively). The analysis highlighted that the simplified lumped-parameter method could not accurately estimate the exposure concentrations within an aircraft cabin. To address this issue, we propose a correction method based on the emission intensity of each VOC source. This study provides critical insights into the diffusion characteristics of VOCs within aircraft cabins and VOC emissions from various sources.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Compuestos Orgánicos Volátiles , Humanos , Compuestos Orgánicos Volátiles/análisis , Contaminación del Aire/análisis , Aeronaves , Pisos y Cubiertas de Piso , Hidrodinámica , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente
9.
J Cell Mol Med ; 27(9): 1239-1249, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36977201

RESUMEN

Although similar to trunk and limb skeletal muscles, masticatory muscles are believed as unique in both developmental origins and myogenesis. Gαi2 has been demonstrated to promote muscle hypertrophy and muscle satellite cell differentiation in limb muscles. However, the effect of Gαi2 on masticatory muscles is still unexplored. This study aimed to identify the role of Gαi2 in the proliferation and differentiation of masticatory muscle satellite cells, further exploring the metabolic mechanism of masticatory muscles. The proliferation rate, myotube size, fusion index of masticatory muscle satellite cells and Pax7, Myf5, MyoD, Tcf21 and Musculin expressions were significantly decreased by Gαi2 knockdown, while in cells infected with AdV4-Gαi2, the proliferation rate, myotube size, fusion index and Tbx1 expression were significantly increased. Masticatory muscle satellite cells also displayed phenotype transformation as Gαi2 changed. In addition, Gαi2 altered myosin heavy chain (MyHC) isoforms of myotubes with less MyHC-2A expression in siGαi2 group and more MyHC-slow expression in AdV4-Gαi2 group. In conclusion, Gαi2 could positively affect the adult myogenesis of masticatory muscle satellite cells and maintain the superiority of MyHC-slow. Masticatory muscle satellite cells may have their unique Gαi2-regulated myogenic transcriptional networks, although they may share some common characteristics with trunk and limb muscles.


Asunto(s)
Células Satélite del Músculo Esquelético , Células Satélite del Músculo Esquelético/metabolismo , Células Cultivadas , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Cadenas Pesadas de Miosina/genética , Diferenciación Celular/genética , Desarrollo de Músculos/genética
10.
J Surg Res ; 282: 160-167, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36306586

RESUMEN

INTRODUCTION: The treatment regimen for early gastric cancer (EGC) with mixed histologic type remains controversial. We aimed to clarify the relationship between mixed histologic type and lymph node metastasis (LNM) in EGC, with emphasis on submucosal invasive EGC. METHODS: We collected data on 730 consecutive EGC patients at Nanjing Drum Tower hospital between June 2010 and May 2019. Risk factors of LNM and overall survival were analyzed to compare the prognostic differences between different histologic types. RESULTS: Mixed-type EGC patients had higher LNM rates than differentiated-type patients (29.2 % versus 10.6 %, P < 0.001), while no significant difference was found between mixed-type and undifferentiated-type EGC patients (29.2% versus 24.0%, P = 0.225). Multivariate analyses identified tumor location (cardiac and bottom versus antrum), larger tumor size, submucosal invasion, histologic differentiation (undifferentiated-type, mixed-type versus differentiated-type), and lymphovascular invasion as independent risk factors for LNM in EGC patients. Subgroup analysis further elucidated that mixed histologic type was associated with LNM in submucosa invasive EGC, but not in mucosa-confined EGC. There was no statistical significance in overall survival and disease-specific survival of submucosal invasive EGC patients who underwent radical gastrectomy with lymphadenectomy between different histologic types (P = 0.151). CONCLUSIONS: Mixed histologic type may be an independent risk factor for LNM in submucosal invasive EGC. Curative resection with lymphadenectomy should be considered the appropriate treatment for submucosal invasive EGC with mixed histologic type.


Asunto(s)
Carcinoma , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Metástasis Linfática/patología , Mucosa Gástrica/cirugía , Mucosa Gástrica/patología , Estudios Retrospectivos , Gastrectomía , Escisión del Ganglio Linfático , Factores de Riesgo , Carcinoma/patología , Invasividad Neoplásica/patología
11.
Environ Res ; 237(Pt 1): 116952, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37619635

RESUMEN

Upper-room ultraviolet germicidal irradiation (UVGI) technology can potentially inhibit the transmission of airborne disease pathogens. There is a lack of quantitative evaluation of the performance of the upper-room UVGI for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) airborne transmission under the combined effects of ventilation and UV irradiation. Therefore, this study aimed to explore the performance of the upper-room UVGI system for reducing SARS-CoV-2 virus transmission in a hospital isolation environment. Computational fluid dynamics and virological data on SARS-CoV-2 were integrated to obtain virus aerosol exposure in the hospital isolation environment containing buffer rooms, wards and bathrooms. The UV inactivation model was applied to investigate the effects of ventilation rate, irradiation flux and irradiation height on the upper-room UVGI performance. The results showed that increasing ventilation rate from 8 to 16 air changes per hour (ACH) without UVGI obtained 54.32% and 45.63% virus reduction in the wards and bathrooms, respectively. However, the upper-room UVGI could achieve 90.43% and 99.09% virus disinfection, respectively, with the ventilation rate of 8 ACH and the irradiation flux of 10 µW cm-2. Higher percentage of virus could be inactivated by the upper-room UVGI at a lower ventilation rate; the rate of improvement of UVGI elimination effect slowed down with the increase of irradiation flux. Increase irradiation height at lower ventilation rate was more effective in improving the UVGI performance than the increase in irradiation flux at smaller irradiation height. These results could provide theoretical support for the practical application of UVGI in hospital isolation environments.

12.
Surg Endosc ; 37(8): 6246-6254, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37188909

RESUMEN

BACKGROUND: There has been great progress in the use of endoscopic ultrasound (EUS)-guided drainage in acute pancreatitis patients using a novel lumen-apposing metal stent (LAMS) in the last decade, but some patients experience bleeding. Our research analyzed the preprocedural risk factors for bleeding. METHODS: From July 13, 2016 to June 23, 2021, we retrospectively analyzed all patients who received endoscopic drainage by the LAMS in our hospital. Univariate and multivariate statistical analyses were used to identify the independent risk factors. We plotted ROC curves based on the independent risk factors. RESULTS: A total of 205 patients were analyzed and 5 patients were excluded. A total of 200 patients were included in our research. Thirty (15%) patients presented with bleeding. In the multivariate analysis, computed tomography severity index score (CTSI) score [odds ratio (OR), 2.66; 95% CI: 1.31-5.38; P = 0.007], positive blood cultures [odds ratio (OR), 5.35; 95% CI: 1.31-21.9; P = 0.02], and Acute Physiology and Chronic Health Evaluation II (APACHE II) score [odds ratio (OR), 1.14; 95% CI: 1. 01-1.29; P = 0.045] were associated with bleeding. The area under the ROC curve of the combined predictive indicator was 0.79. CONCLUSION: Bleeding in endoscopic drainage by the LAMS is significantly associated with the CTSI score, positive blood cultures, and APACHE II score. This result could help clinicians make more appropriate choices.


Asunto(s)
Pancreatitis , Humanos , Estudios Retrospectivos , Pancreatitis/complicaciones , Pancreatitis/cirugía , Enfermedad Aguda , Resultado del Tratamiento , Endosonografía/efectos adversos , Stents/efectos adversos , Drenaje/efectos adversos , Drenaje/métodos , Hemorragia/etiología
13.
Int J Mol Sci ; 24(9)2023 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-37175747

RESUMEN

OsMADS1 plays a vital role in regulating floret development and grain shape, but whether it regulates rice grain quality still remains largely unknown. Therefore, we used comprehensive molecular genetics, plant biotechnology, and functional omics approaches, including phenotyping, mapping-by-sequencing, target gene seed-specific RNAi, transgenic experiments, and transcriptomic profiling to answer this biological and molecular question. Here, we report the characterization of the 'Oat-like rice' mutant, with poor grain quality, including chalky endosperms, abnormal morphology and loose arrangement of starch granules, and lower starch content but higher protein content in grains. The poor grain quality of Oat-like rice was found to be caused by the mutated OsMADS1Olr allele through mapping-by-sequencing analysis and transgenic experiments. OsMADS1 protein is highly expressed in florets and developing seeds. Both OsMADS1-eGFP and OsMADS1Olr-eGFP fusion proteins are localized in the nucleus. Moreover, seed-specific RNAi of OsMADS1 also caused decreased grain quality in transgenic lines, such as the Oat-like rice. Further transcriptomic profiling between Oat-like rice and Nipponbare grains revealed that OsMADS1 regulates gene expressions and regulatory networks of starch and storage protein metabolisms in rice grains, hereafter regulating rice quality. In conclusion, our results not only reveal the crucial role and preliminary mechanism of OsMADS1 in regulating rice grain quality but also highlight the application potentials of OsMADS1 and the target gene seed-specific RNAi system in improving rice grain quality by molecular breeding.


Asunto(s)
Oryza , Almidón , Almidón/genética , Almidón/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Endospermo/metabolismo , Grano Comestible/genética , Grano Comestible/metabolismo , Expresión Génica , Regulación de la Expresión Génica de las Plantas
14.
J Am Chem Soc ; 144(13): 5855-5863, 2022 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-35333525

RESUMEN

As practitioners of organic chemistry strive to deliver efficient syntheses of the most complex natural products and drug candidates, further innovations in synthetic strategies are required to facilitate their efficient construction. These aspirational breakthroughs often go hand-in-hand with considerable reductions in cost and environmental impact. Enzyme-catalyzed reactions have become an impressive and necessary tool that offers benefits such as increased selectivity and waste limitation. These benefits are amplified when enzymatic processes are conducted in a cascade in combination with novel bond-forming strategies. In this article, we report a highly diastereoselective synthesis of MK-1454, a potent agonist of the stimulator of interferon gene (STING) signaling pathway. The synthesis begins with the asymmetric construction of two fluoride-bearing deoxynucleotides. The routes were designed for maximum convergency and selectivity, relying on the same benign electrophilic fluorinating reagent. From these complex subunits, four enzymes are used to construct the two bridging thiophosphates in a highly selective, high yielding cascade process. Critical to the success of this reaction was a thorough understanding of the role transition metals play in bond formation.


Asunto(s)
Productos Biológicos , Productos Biológicos/química , Catálisis
15.
Anal Chem ; 94(40): 13795-13803, 2022 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-36154017

RESUMEN

N-Nitrosamines are strictly regulated in pharmaceutical products due to their carcinogenic nature. Therefore, the ability to rapidly and reliably identify the N-nitroso functionality is urgently needed. Unfortunately, not all ionized N-nitroso compounds produce diagnostic fragment ions and hence tandem mass spectrometry based on collision-activated dissociation (CAD) cannot be used to consistently identify the N-nitroso functionality. Therefore, a more reliable method was developed based on diagnostic functional-group selective ion-molecule reactions in a linear quadrupole ion trap mass spectrometer. 2-Methoxypropene (MOP) was identified as a reagent that reacts with protonated N-nitrosamines in a diagnostic manner by forming an adduct followed by the elimination of 2-propenol (CH3C(OH)═CH2]). From 18 protonated N-nitrosamine model compounds studied, 15 formed the diagnostic product ion. The lack of the diagnostic reaction for three of the N-nitrosamine model compounds was rationalized based on the presence of a pyridine ring that gets preferentially protonated instead of the N-nitroso functionality. These N-nitrosamines can be identified by subjecting a stable adduct formed upon ion-molecule reactions with MOP to CAD. Further, the ability to use ion-molecule reactions followed by CAD to differentiate protonated O-nitroso compounds with a pyridine ring from analogous N-nitrosamines was demonstrated This methodology is considered to be robust for the identification of the N-nitroso functionality in unknown analytes. Lastly, HPLC/MS2 experiments were performed to determine the detection limit for five FDA regulated N-nitrosamines.


Asunto(s)
Nitrosaminas , Espectrometría de Masas en Tándem , Iones/química , Preparaciones Farmacéuticas , Piridinas , Espectrometría de Masas en Tándem/métodos
16.
Electrophoresis ; 43(5-6): 717-723, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34657307

RESUMEN

Recent studies have demonstrated the strong influences of fluid rheological properties on insulator-based dielectrophoresis (iDEP) in single-constriction microchannels. However, it is yet to be understood how iDEP in non-Newtonian fluids depends on the geometry of insulating structures. We report in this work an experimental study of fluid rheological effects on streaming DEP in a post-array microchannel that presents multiple contractions and expansions. The iDEP focusing and trapping of particles in a viscoelastic polyethylene oxide solution are comparable to those in a Newtonian buffer, which is consistent with the observations in a single-constriction microchannel. Similarly, the insignificant iDEP effects in a shear-thinning xanthan gum solution also agree with those in the single-constriction channel except that gel-like structures are observed to only form in the post-array microchannel under large DC electric fields. In contrast, the iDEP effects in both viscoelastic and shear-thinning polyacrylamide solution are significantly weaker than in the single-constriction channel. Moreover, instabilities occur in the electroosmotic flow and appear to be only dependent on the DC electric field. These phenomena may be associated with the dynamics of polymers as they are electrokinetically advected around and through the posts.


Asunto(s)
Técnicas Analíticas Microfluídicas , Electricidad , Electroósmosis/métodos , Electroforesis/métodos , Técnicas Analíticas Microfluídicas/métodos , Reología
17.
Biotechnol Bioeng ; 119(8): 2088-2104, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35437754

RESUMEN

Host cell proteins (HCPs) are a significant class of process-related impurities commonly associated with the manufacturing of biopharmaceuticals. However, due to the increased use of crude enzymes as biocatalysts for modern organic synthesis, HCPs can also be introduced as a new class of impurities in chemical drugs. In both cases, residual HCPs need to be adequately controlled to ensure product purity, quality, and patient safety. Although a lot of attentions have been focused on defining a universally acceptable limit for such impurities, the risks associated with residual HCPs on product quality, safety, and efficacy often need to be determined on a case-by-case basis taking into consideration the residual HCP profile in the product, the dose, dosage form, administration route, and so forth. Here we describe the unique challenges for residual HCP control presented by the biocatalytic synthesis of an investigational stimulator of interferon genes protein agonist, MK-1454, which is a cyclic dinucleotide synthesized using Escherichia coli cell lysate overexpressing cyclic GMP-AMP synthase as a biocatalyst. In this study, a holistic characterization of residual protein impurities using a variety of analytical tools including nanoscale liquid chromatography coupled to tandem mass spectrometry, together with in silico immunogenicity prediction of identified proteins, facilitated risk assessment and guided process development to achieve adequate removal of residual protein impurities in MK-1454 active pharmaceutical ingredient.


Asunto(s)
Proteínas , Animales , Células CHO , Cricetinae , Cricetulus , Humanos , Preparaciones Farmacéuticas , Proteínas/análisis , Medición de Riesgo
18.
Nutr Cancer ; 74(10): 3574-3581, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35762207

RESUMEN

Postoperative complications of gastrectomy for gastric cancer affect the efficacy of surgery. It is of clinical significance to identify high-risk patients with postoperative complications as early as possible. A total of 206 patients who underwent gastrectomy were enrolled in this study. Univariate and multivariate analyses were used to determine the risk factors for postoperative complications. The cutoff value and diagnostic accuracy of the C-reactive protein/albumin ratio were calculated by receiver operating characteristic curves. A total of 64 (31.1%) patients developed postoperative complications. Multivariate analysis confirmed that the C-reactive protein/albumin ratio on the first day after operation was an independent risk factor for postoperative complications (OR = 2.538, 95%CI: 1.346-4.785, P = 0.004). The cutoff value of the C-reactive protein/albumin ratio on the first day after operation was 2.105 calculated by receiver operating characteristic curves. Patients with a C-reactive protein/albumin ratio greater than 2.105 had a higher incidence of postoperative complications (43.2% vs 22.0%, P = 0.001) and longer postoperative hospital stay (15.3 ± 1.2 vs 13.0 ± 0.5, P = 0.042) than patients with less than 2.105. Patients with C-reactive protein/albumin ratio greater than 2.105 on the first day after operation are more likely to have postoperative complications.


Asunto(s)
Neoplasias Gástricas , Albúminas , Proteína C-Reactiva/análisis , Gastrectomía/efectos adversos , Humanos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Neoplasias Gástricas/etiología
19.
Indoor Air ; 32(11): e13178, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36437656

RESUMEN

Ozone and byproducts of ozone-initiated reactions are among the primary pollutants in aircraft cabins. However, investigations of the spatial distribution and reaction mechanisms of these pollutants are insufficient. This study established a computational fluid dynamics-based model to evaluate ozone and byproduct distribution, considering ozone reactions in air, adsorption onto surfaces, and byproduct desorption from surfaces. The model was implemented in an authentic single-aisle aircraft cabin and validated by measurements recorded during the aircraft cruise phase. Ozone concentrations in the supply air-dominated area were approximately 50% higher than that in the passenger breathing zone, suggesting that human surfaces represent a significant ozone sink. The deposition velocity onto human bodies was 21.83 m/h, surpassing 3.97 m/h on other cabin interior surface areas. Our model provides a mechanistic tool to analyze ozone and byproduct concentration distributions, which would be useful for assessing passenger health risks and for developing strategies for healthier aircraft cabin environments.


Asunto(s)
Contaminación del Aire Interior , Contaminantes Ambientales , Ozono , Humanos , Ozono/análisis , Contaminación del Aire Interior/análisis , Aeronaves , Hidrodinámica
20.
Clin Oral Investig ; 26(9): 5625-5642, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35786783

RESUMEN

OBJECTIVES: The purpose of this systematic review was to compare the accuracy of digital and conventional full-arch impressions in vivo. MATERIALS AND METHODS: This systematic review was conducted according to the PRISMA and registered at the PROSPERO (CRD42021232736). Electronic and hand searches were performed to identify in vivo studies comparing the linear or 3D accuracy of digital and conventional impressions. The risk of bias (ROB) of included studies was assessed by QUADAS-2, and the overall quality of evidence was assessed by GRADE. RESULTS: Twenty-two studies met the inclusion criteria, and 13 studies were included in the meta-analysis. There was no significant difference between digital and conventional impressions in the linear measurements of tooth width, anterior Bolton ratio, overall Bolton ratio, intercanine distance (ICD), and intermolar distance (IMD). The repeated measurement mean errors (RMEs) were less than 0.1 mm, the intra-examiner intraclass correlation coefficient (ICC) values were more than 0.9, and the inter-examiner ICC values were more than 0.87 for both impression techniques. The 3D deviation between digital and alginate impressions was 0.09 mm. The 3D precision of both impression techniques was less than 0.1 mm. CONCLUSIONS: The trueness of digital and alginate full-arch impressions was similar, and both impression techniques showed high precision. More research was needed to compare digital impressions and other conventional impression materials. CLINICAL RELEVANCE: For patients with completely natural dentition, the digital impressions obtained directly from intraoral scanning can be considered a viable alternative to alginate impressions.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Alginatos , Diseño Asistido por Computadora , Arco Dental , Materiales de Impresión Dental , Humanos , Imagenología Tridimensional/métodos
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