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1.
Bioorg Med Chem Lett ; 105: 129744, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38614152

RESUMEN

Two tryptophan compound classes 5- and 6-borono PEGylated boronotryptophan derivatives have been prepared for assessing their aqueous solubility as formulation of injections for boron neutron capture therapy (BNCT). The PEGylation has improved their aqueous solubility thereby increasing their test concentration in 1 mM without suffering from toxicity. In-vitro uptake assay of PEGylated 5- and 6-boronotryptophan showed that the B-10 concentration can reach 15-50 ppm in U87 cell whereas the uptake in LN229 cell varies. Shorter PEG compound 6-boronotryptophanPEG200[18F] was obtained in 1.7 % radiochemical yield and the PET-derived radioradioactivity percentage in 18 % was taken up by U87 tumor at the limb of xenograft mouse. As high as tumor to normal uptake ratio in 170 (T/N) was obtained while an inferior radioactivity uptake of 3 % and T/N of 8 was observed in LN229 xenografted mouse.


Asunto(s)
Terapia por Captura de Neutrón de Boro , Neoplasias Encefálicas , Radioisótopos de Flúor , Polietilenglicoles , Tomografía de Emisión de Positrones , Animales , Ratones , Humanos , Radioisótopos de Flúor/química , Polietilenglicoles/química , Línea Celular Tumoral , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/metabolismo , Compuestos de Boro/química , Compuestos de Boro/farmacocinética , Compuestos de Boro/síntesis química , Triptófano/química , Triptófano/análogos & derivados , Triptófano/farmacocinética , Triptófano/síntesis química , Estructura Molecular
2.
Eur J Nucl Med Mol Imaging ; 50(2): 287-301, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36271158

RESUMEN

BACKGROUND: ZED8 is a novel monovalent antibody labeled with zirconium-89 for the molecular imaging of CD8. This work describes nonclinical studies performed in part to provide rationale for and to inform expectations in the early clinical development of ZED8, such as in the studies outlined in clinical trial registry NCT04029181 [1]. METHODS: Surface plasmon resonance, X-ray crystallography, and flow cytometry were used to characterize the ZED8-CD8 binding interaction, its specificity, and its impact on T cell function. Immuno-PET with ZED8 was assessed in huCD8+ tumor-bearing mice and in non-human primates. Plasma antibody levels were measured by ELISA to determine pharmacokinetic parameters, and OLINDA 1.0 was used to estimate radiation dosimetry from image-derived biodistribution data. RESULTS: ZED8 selectively binds to human CD8α at a binding site approximately 9 Å from that of MHCI making mutual interference unlikely. The equilibrium dissociation constant (KD) is 5 nM. ZED8 binds to cynomolgus CD8 with reduced affinity (66 nM) but it has no measurable affinity for rat or mouse CD8. In a series of lymphoma xenografts, ZED8 imaging was able to identify different CD8 levels concordant with flow cytometry. In cynomolgus monkeys with tool compound 89Zr-aCD8v17, lymph nodes were conspicuous by imaging 24 h post-injection, and the pharmacokinetics suggested a flat-fixed first-in-human dose of 4 mg per subject. The whole-body effective dose for an adult human was estimated to be 0.48 mSv/MBq, comparable to existing 89Zr immuno-PET reagents. CONCLUSION: 89Zr immuno-PET with ZED8 appears to be a promising biomarker of tissue CD8 levels suitable for clinical evaluation in cancer patients eligible for immunotherapy.


Asunto(s)
Neoplasias , Tomografía de Emisión de Positrones , Adulto , Humanos , Ratones , Ratas , Animales , Tomografía de Emisión de Positrones/métodos , Indicadores y Reactivos/uso terapéutico , Distribución Tisular , Neoplasias/terapia , Neoplasias/tratamiento farmacológico , Inmunoterapia/métodos , Circonio/química , Linfocitos T CD8-positivos/metabolismo , Línea Celular Tumoral
3.
Dig Endosc ; 35(4): 512-519, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36374127

RESUMEN

OBJECTIVES: Malignant gastric outlet obstruction (GOO) can be relieved by either laparoscopic gastrojejunostomy (LGJ), endoscopic stenting (SEMS) or endoscopic ultrasound-guided gastrojejunostomy (endoscopic ultrasound-guided balloon-occluded gastrojejunostomy bypass; EPASS). This study aimed to compare the outcomes of the three treatment methods. METHODS: This was a retrospective study of patients who suffered from malignant GOO between January 2012 to November 2020 that received either EPASS, LGJ or SEMS. The outcomes included the technical and clinical success, 30-day adverse events and mortality, pre and post stenting GOO scores (GOOSs), stent patency and causes of stent dysfunction. RESULTS: One hundred and fourteen patients were included (30 EPASS, 35 LGJ, 49 SEMS). The technical success of EPASS, LGJ and SEMS were 93.3%, 100%, 100% (P = 0.058) and clinical success rates were 93.3%, 80%, 87.8% (P = 0.276), respectively. Procedural time was longest for the LGJ group (P < 0.001). The EPASS group had the shortest hospital stay (EPASS 1.5 [1-17], LGJ 7 [2-44], SEMS 5 [2-46] days, P < 0.001). EPASS group also had the lowest rates of recurrent obstruction (EPASS 3.3%, LGJ 17.1%, SEMS 36.7%, P = 0.002) and re-intervention (EPASS 3.3%, LGJ 17.1%, SEMS 26.5%, P = 0.031). The 1-month GOOS was highest in the EPASS group (EPASS 3 [1-3], LGJ 3 [0-3], SEMS 2 [0-3], P = 0.028). CONCLUSION: Endoscopic ultrasound-guided gastrojejunostomy was associated with better clinical outcomes then the other two procedures. The procedure may be the best option provided that the expertise is available.


Asunto(s)
Derivación Gástrica , Obstrucción de la Salida Gástrica , Laparoscopía , Humanos , Derivación Gástrica/efectos adversos , Estudios Retrospectivos , Cuidados Paliativos/métodos , Laparoscopía/métodos , Stents/efectos adversos , Obstrucción de la Salida Gástrica/etiología , Obstrucción de la Salida Gástrica/cirugía , Ultrasonografía Intervencional
4.
Molecules ; 27(9)2022 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-35566202

RESUMEN

A small fenbufen library comprising 18 compounds was prepared via Suzuki Miyara coupling. The five-step preparations deliver 9-17% biphenyl compounds in total yield. These fenbufen analogs exert insignificant activity against the IL-1 release as well as inhibiting cyclooxygenase 2 considerably. Both the para-amino and para-hydroxy mono substituents display the most substantial COX-2 inhibition, particularly the latter one showing a comparable activity as celecoxib. The most COX-2 selective and bioactive disubstituted compound encompasses one electron-withdrawing methyl and one electron-donating fluoro groups in one arene. COX-2 is selective but not COX-2 to bioactive compounds that contain both two electron-withdrawing groups; disubstituted analogs with both resonance-formable electron-donating dihydroxy groups display high COX-2 activity but inferior COX-2 selectivity. In silico simulation and modeling for three COX-2 active-p-fluoro, p-hydroxy and p-amino-fenbufens show a preferable docking to COX-2 than COX-1. The most stabilization by the p-hydroxy fenbufen with COX-2 predicted by theoretical simulation is consistent with its prominent COX-2 inhibition resulting from experiments.


Asunto(s)
Inhibidores de la Ciclooxigenasa 2 , Diseño de Fármacos , Antiinflamatorios/farmacología , Bioensayo , Ciclooxigenasa 1 , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa 2/farmacología , Simulación del Acoplamiento Molecular , Estructura Molecular , Fenilbutiratos , Relación Estructura-Actividad
5.
Proteomics ; 21(17-18): e2100036, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33811468

RESUMEN

SARS-CoV-2 has caused a significant ongoing pandemic worldwide. A number of studies have examined the T cell mediated immune responses against SARS-CoV-2, identifying potential T cell epitopes derived from the SARS-CoV-2 proteome. Such studies will aid in identifying targets for vaccination and immune monitoring. In this study, we applied tandem mass spectrometry and proteomic techniques to a library of ∼40,000 synthetic peptides, in order to generate a large dataset of SARS-CoV-2 derived peptide MS/MS spectra. On this basis, we built an online knowledgebase, termed virusMS (https://virusms.erc.monash.edu/), to document, annotate and analyse these synthetic peptides and their spectral information. VirusMS incorporates a user-friendly interface to facilitate searching, browsing and downloading the database content. Detailed annotations of the peptides, including experimental information, peptide modifications, predicted peptide-HLA (human leukocyte antigen) binding affinities, and peptide MS/MS spectral data, are provided in virusMS.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Péptidos , Proteómica , Espectrometría de Masas en Tándem
6.
Bioorg Med Chem ; 27(1): 216-223, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30528163

RESUMEN

The [18F] isotope-labelled CB1 inverse agonist 3 was elaborated and synthesized for positron emission tomography scanning studies. After immediate purification and calibration with its unlabeled counterpart, compound 3 was intravenously injected in mice and revealed that its distribution percentage in brain over 90-min scans among five region of interests, including brain, liver, heart, thigh muscle and kidney was lower than 1%, thus providing direct evidence to justify itself as a peripherally restricted CB1 antagonist.


Asunto(s)
Agonistas de Receptores de Cannabinoides/farmacología , Pirazoles/farmacología , Receptor Cannabinoide CB1/agonistas , Sulfonamidas/farmacología , Tiofenos/farmacología , Animales , Agonistas de Receptores de Cannabinoides/síntesis química , Agonistas de Receptores de Cannabinoides/química , Agonistas de Receptores de Cannabinoides/farmacocinética , Agonismo Inverso de Drogas , Radioisótopos de Flúor , Marcaje Isotópico , Masculino , Ratones Endogámicos C57BL , Tomografía de Emisión de Positrones/métodos , Pirazoles/síntesis química , Pirazoles/química , Pirazoles/farmacocinética , Receptor Cannabinoide CB1/antagonistas & inhibidores , Sulfonamidas/síntesis química , Sulfonamidas/química , Sulfonamidas/farmacocinética , Tiofenos/química , Tiofenos/farmacocinética , Distribución Tisular
7.
Arch Phys Med Rehabil ; 100(12): 2225-2232, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31421096

RESUMEN

OBJECTIVE: To investigate the effects of unilateral hybrid therapy (UHT) and bilateral hybrid therapy (BHT) compared with robot-assisted therapy (RT) alone in patients with chronic stroke. DESIGN: A single-blind, randomized controlled trial. SETTING: Four hospitals. PARTICIPANTS: Outpatients with chronic stroke and mild to moderate motor impairment (N=44). INTERVENTION: UHT combined unilateral RT (URT) and modified constraint-induced therapy. BHT combined bilateral RT (BRT) and bilateral arm training. The RT group received URT and BRT. The intervention frequency for the 3 groups was 90 min/d 3 d/wk for 6 weeks. MAIN OUTCOME MEASURES: Fugl-Meyer Assessment (FMA, divided into the proximal and distal subscale) and Stroke Impact Scale (SIS) version 3.0 scores before, immediately after, and 3 months after treatment and Wolf Motor Function Test (WMFT) and Nottingham Extended Activities of Daily Living (NEADL) scale scores before and immediately after treatment. RESULTS: The results favored BHT over UHT on the FMA total score and distal score at the posttest (P=.03 and .04) and follow-up (P=.01 and .047) assessment and BHT over RT on the follow-up FMA distal scores (P=.03). At the posttest assessment, the WMFT and SIS scores of the 3 groups improved significantly without between-group differences, and the RT group showed significantly greater improvement in the mobility domain of NEADL compared with the BHT group (P<.01). CONCLUSIONS: BHT was more effective for improving upper extremity motor function, particularly distal motor function at follow-up, and individuals in the RT group demonstrated improved functional ambulation post intervention.


Asunto(s)
Terapia por Ejercicio/métodos , Robótica , Rehabilitación de Accidente Cerebrovascular/métodos , Extremidad Superior/fisiopatología , Actividades Cotidianas , Adulto , Anciano , Fenómenos Biomecánicos , Enfermedad Crónica , Evaluación de la Discapacidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rango del Movimiento Articular , Recuperación de la Función , Método Simple Ciego
8.
Am J Occup Ther ; 73(1): 7301205010p1-7301205010p9, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30839256

RESUMEN

OBJECTIVE: We investigated the effects on motor and daily function of robot-assisted therapies in people with chronic stroke using the Bi-Manu-Track (BMT) and InMotion 3.0 (IMT) compared with control treatment (CT). METHOD: In this comparative efficacy trial, 30 participants were randomized to receive BMT, IMT, or CT. Outcome measures included the Fugl-Meyer Assessment (FMA), Modified Ashworth Scale (MAS), Motor Activity Log (MAL), and Medical Research Council (MRC) scale. RESULTS: The IMT group improved more in FMA and proximal MAS scores than the BMT group (both ps < .01) and the CT group (p < .01 and p = .03, respectively). The IMT and BMT groups showed clinically relevant improvements after treatment on the MRC rather than the MAL. CONCLUSION: The results indicate that the IMT might improve motor function. The IMT and BMT groups showed similar benefits for muscle power but limited improvements in self-perceived use of the affected arm.


Asunto(s)
Terapia por Ejercicio/instrumentación , Robótica , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/fisiopatología , Extremidad Superior/fisiopatología , Femenino , Hemiplejía/fisiopatología , Hemiplejía/rehabilitación , Humanos , Masculino , Paresia/fisiopatología , Paresia/rehabilitación , Satisfacción del Paciente , Recuperación de la Función/fisiología , Resultado del Tratamiento
9.
J Biol Chem ; 292(9): 3900-3908, 2017 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-28077575

RESUMEN

The antibody Fc region regulates antibody cytotoxic activities and serum half-life. In a therapeutic context, however, the cytotoxic effector function of an antibody is often not desirable and can create safety liabilities by activating native host immune defenses against cells expressing the receptor antigens. Several amino acid changes in the Fc region have been reported to silence or reduce the effector function of antibodies. These earlier studies focused primarily on the interaction of human antibodies with human Fc-γ receptors, and it remains largely unknown how such changes to Fc might translate to the context of a murine antibody. We demonstrate that the commonly used N297G (NG) and D265A, N297G (DANG) variants that are efficacious in attenuating effector function in primates retain potent complement activation capacity in mice, leading to safety liabilities in murine studies. In contrast, we found an L234A, L235A, P329G (LALA-PG) variant that eliminates complement binding and fixation as well as Fc-γ-dependent, antibody-dependent, cell-mediated cytotoxity in both murine IgG2a and human IgG1. These LALA-PG substitutions allow a more accurate translation of results generated with an "effectorless" antibody between mice and primates. Further, we show that both human and murine antibodies containing the LALA-PG variant have typical pharmacokinetics in rodents and retain thermostability, enabling efficient knobs-into-holes bispecific antibody production and a robust path to generating highly effector-attenuated bispecific antibodies for preclinical studies.


Asunto(s)
Anticuerpos Biespecíficos/inmunología , Inmunoglobulina G/química , Animales , Formación de Anticuerpos , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Complemento C1q/inmunología , Cricetinae , Cristalografía por Rayos X , Ensayo de Inmunoadsorción Enzimática , Glicosilación , Humanos , Fragmentos Fc de Inmunoglobulinas/inmunología , Inmunoglobulina G/genética , Ratones , Conformación Proteica , Receptores de IgG/metabolismo , Temperatura
11.
J Environ Manage ; 183: 253-259, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27596939

RESUMEN

Despite considered a non-consumptive use of the marine environment, diving-related activities can cause damages to coral reefs. It is imminent to assess the maximum numbers of divers that can be accommodated by a diving site before it is subject to irreversible deterioration. This study aimed to assess the ecological carrying capacity of a diving site in Mabul Island, Malaysia. Photo-quadrat line transect method was used in the benthic survey. The ecological carrying capacity was assessed based on the relationship between the number of divers and the proportion of diver damaged hard corals in Mabul Island. The results indicated that the proportion of diver damaged hard corals occurred exponentially with increasing use. The ecological carrying capacity of Mabul Island is 15,600-16,800 divers per diving site per year at current levels of diver education and training with a quarterly threshold of 3900-4200 per site. Our calculation shows that management intervention (e.g. limiting diving) is justified at 8-14% of hard coral damage. In addition, the use of coral reef dominated diving sites should be managed according to their sensitivity to diver damage and the depth of the reefs.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Buceo/efectos adversos , Ecología , Animales , Antozoos/fisiología , Arrecifes de Coral , Humanos , Islas , Malasia , Estaciones del Año
12.
Molecules ; 21(3): 387, 2016 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-27007363

RESUMEN

Molecular imaging of brain tumors remains a great challenge, despite the advances made in imaging technology. An anti-inflammatory compound may be a useful tool for this purpose because there is evidence of inflammatory processes in brain tumor micro-environments. Fluorooctylfenbufen amide (FOFA) was prepared from 8-chlorooctanol via treatment with potassium phthalimide, tosylation with Ts2O, fluorination with KF under phase transfer catalyzed conditions, deprotection using aqueous hydrazine, and coupling with fenbufen. The corresponding radiofluoro product [(18)F]FOFA, had a final radiochemical yield of 2.81 mCi and was prepared from activated [(18)F]F(-) (212 mCi) via HPLC purification and concentration. The radiochemical purity was determined to be 99%, and the specific activity was shown to exceed 22 GBq/µmol (EOS) based on decay-corrected calculations. Ex-vivo analysis of [(18)F]FOFA in plasma using HPLC showed that the agent had a half-life of 15 min. PET scanning showed significant accumulation of [(18)F]FOFA over tumor loci with reasonable contrast in C6-glioma bearing rats. These results suggest that this molecule is a promising agent for the visualization of brain tumors. Further investigations should focus on tumor micro-environments.


Asunto(s)
Glioma/diagnóstico por imagen , Fenilbutiratos/administración & dosificación , Fenilbutiratos/síntesis química , Animales , Radioisótopos de Flúor/administración & dosificación , Radioisótopos de Flúor/química , Glioma/patología , Humanos , Marcaje Isotópico , Fenilbutiratos/química , Tomografía de Emisión de Positrones , Ratas
13.
Traffic ; 13(7): 992-1003, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22498042

RESUMEN

STIM1 is a core component of the store-operated Ca²âº-entry channel involved in Ca²âº-signaling with an important role in the activation of immune cells and many other cell types. In response to cell activation, STIM1 protein senses low Ca²âº concentration in the lumen of the endoplasmic reticulum (ER) and activates the channel protein Orai1 in the plasma membrane by direct physical contact. The related protein STIM2 functions similar but its physiological role is less well defined. We found that STIM2, but not STIM1, contains a di-lysine ER-retention signal. This restricts the function of STIM2 as Ca²âº sensor to the ER while STIM1 can reach the plasma membrane. The intracellular distribution of STIM1 is regulated in a cell-cycle-dependent manner with cell surface expression of STIM1 during mitosis. Efficient retention of STIM1 in the ER during interphase depends on its lysine-rich domain and a di-arginine ER retention signal. Store-operated Ca²âº-entry enhanced ER retention, suggesting that trafficking of STIM1 is regulated and this regulation contributes to STIM1s role as multifunctional component in Ca²âº-signaling.


Asunto(s)
Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Señales de Clasificación de Proteína , Canales de Calcio/metabolismo , Señalización del Calcio , Moléculas de Adhesión Celular/química , Moléculas de Adhesión Celular/metabolismo , Retículo Endoplásmico/metabolismo , Células HEK293 , Células HeLa , Humanos , Proteínas de la Membrana/genética , Proteínas de Neoplasias/genética , Proteína ORAI1 , Estructura Terciaria de Proteína , Transporte de Proteínas , Proteínas Recombinantes de Fusión , Molécula de Interacción Estromal 1 , Molécula de Interacción Estromal 2
14.
J Pharm Sci ; 113(7): 1975-1986, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38561054

RESUMEN

Sialic acid (SA) is crucial for protecting glycoproteins from clearance. Efmarodocokin alfa (IL-22Fc), a fusion protein agonist that links IL-22 to the crystallizable fragment (Fc) of human IgG4, contains 8 N-glycosylation sites and exhibits heterogeneous and variable terminal sialylation biodistribution. This presents a unique challenge for Pharmacokinetic (PK) and Pharmacodynamic (PD) analysis and cross-species translation. In this study, we sought to understand how varying SA levels and heterogeneous distribution contribute to IL-22Fc's complex PKPD properties. We initially used homogenous drug material with varying SA levels to examine PKPD in mice. Population PKPD analysis based on mouse data revealed that SA was a critical covariate simultaneously accounting for the substantial between subject variability (BSV) in clearance (CL), distribution clearance (CLd), and volume of distribution (Vd). In addition to the well-established mechanism by which SA inhibits ASGPR activity, we hypothesized a novel mechanism by which decrease in SA increases the drug uptake by endothelial cells. This decrease in SA, leading to more endothelial uptake, was supported by the neonatal Fc receptor (FcRn) dependent cell-based transcytosis assay. The population analysis also suggested in vivo EC50 (IL-22Fc stimulating Reg3ß) was independent on SA, while the in-vitro assay indicated a contradictory finding of SA-in vitro potency relationship. We created a mechanism based mathematical (MBM) PKPD model incorporating the decrease in SA mediated endothelial and hepatic uptake, and successfully characterized the SA influence on IL-22Fc PK, as well as the increased PK exposure being responsible for increased PD. Thereby, the MBM model supported that SA has no direct impact on EC50, aligning with the population PKPD analysis. Subsequently, using the MBM PKPD model, we employed 5 subpopulation simulations to reconstitute the heterogeneity of drug material. The simulation accurately predicted the PKPD of heterogeneously and variably sialylated drug in mouse, monkey and human. The successful prospective validation confirmed the MBM's ability to predict IL-22Fc PK across variable SA levels, homogenous to heterogeneous material, and across species (R2=0.964 for clearance prediction). Our model prediction suggests an average of 1 mol/mol SA increase leads to a 50% increase in drug exposure. This underlines the significance of controlling sialic acid levels during lot-to-lot manufacturing.


Asunto(s)
Interleucina-22 , Interleucinas , Hígado , Ácido N-Acetilneuramínico , Proteínas Recombinantes de Fusión , Animales , Ratones , Hígado/metabolismo , Hígado/efectos de los fármacos , Ácido N-Acetilneuramínico/metabolismo , Glicosilación , Humanos , Proteínas Recombinantes de Fusión/farmacocinética , Proteínas Recombinantes de Fusión/metabolismo , Interleucinas/metabolismo , Interleucinas/farmacocinética , Distribución Tisular , Masculino , Modelos Biológicos , Células Endoteliales/metabolismo , Células Endoteliales/efectos de los fármacos
15.
J Biol Chem ; 287(8): 5891-7, 2012 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-22203673

RESUMEN

Upper hinge is vulnerable to radical attacks that result in breakage of the heavy-light chain linkage and cleavage of the hinge of an IgG1. To further explore mechanisms responsible for the radical induced hinge degradation, nine mutants were designed to determine the roles that the upper hinge Asp and His play in the radical reactions. The observation that none of these substitutions could inhibit the breakage of the heavy-light chain linkage suggests that the breakage may result from electron transfer from Cys(231) directly to the heavy-light chain linkage upon radical attacks, and implies a pathway separate from His(229)-mediated hinge cleavage. On the other hand, the substitution of His(229) with Tyr showed promising advantages over the native antibody and other substitutions in improving the stability and function of the IgG1. This substitution inhibited the hinge cleavage by 98% and suggests that the redox active nature of Tyr did not enable it to replicate the ability of His to facilitate radical induced degradation. We propose that the lower redox potential of Tyr, a residue that may be the ultimate sink for oxidizing equivalents in proteins, is responsible for the inhibition. More importantly, the substitution increased the antibody's binding to FcγRIII receptors by 2-3-fold, and improved ADCC activity by 2-fold, while maintaining a similar pharmacokinetic profile with respect to the wild type. Implications of these observations for antibody engineering and development are discussed.


Asunto(s)
Inmunoglobulina G/química , Inmunoglobulina G/metabolismo , Ingeniería de Proteínas/métodos , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Células CHO , Cricetinae , Cricetulus , Estudios de Factibilidad , Humanos , Radical Hidroxilo/farmacología , Inmunoglobulina G/genética , Cadenas Pesadas de Inmunoglobulina/química , Cadenas Ligeras de Inmunoglobulina/química , Datos de Secuencia Molecular , Mutación , Estabilidad Proteica , Proteolisis/efectos de los fármacos
16.
Environ Manage ; 51(4): 824-37, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23471632

RESUMEN

Diving-related activities may constitute a major threat to coral reefs. This study aimed to quantify the impact of diving in Hong Kong on hard corals and understand how socio-economic characteristics and experience level of divers influence diver-inflicted damage. We recorded and analysed the underwater behaviour of 81 recreational divers. On average, a diver was in contact with marine biota 14.7 times with about 40% of contacts involved corals and 38% were damaging contacts with corals or other biota in a single dive. The most harm-inflicting groups included inexperienced and camera-carrying divers. Although Hong Kong divers did not make many damaging contacts with corals, there is still an imminent need to determine the scale of damage from diving activities on the marine ecosystem given the rapid development of marine-based tourism and the limited coral-inhabited areas in Hong Kong where the marine environment is already under stress from anthropogenic activities.


Asunto(s)
Buceo , Animales , Antozoos , Conservación de los Recursos Naturales , Ecosistema , Hong Kong , Humanos
17.
Pharmaceuticals (Basel) ; 16(1)2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36678590

RESUMEN

Boron neutron capture therapy (BNCT) is a binary therapeutic technique employing a boron agent to be delivered to the tumor site followed by the irradiation of neutrons. Biofunctional molecules/nanoparticles labeled with F-18 can provide an initial pharmacokinetic profile of patients to guide the subsequent treatment planning procedure of BNCT. Borono phenylalanine (BPA), recognized by the l-type amino acid transporter, can cross the blood-brain barrier and be accumulated in gliomas. The radiofluoro BNCT agents are reviewed by considering (1) less cytotoxicity, (2) diagnosing and therapeutic purposes, (3) aqueous solubility and extraction route, as well as (4), the trifluoroborate effect. A trifluoroborate-containing amino acid such as fluoroboronotyrosine (FBY) represents an example with both functionalities of imaging and therapeutics. Comparing with the insignificant cytotoxicity of clinical BPA with IC50 > 500 µM, FBY also shows minute toxicity with IC50 > 500 µM. [18F]FBY is a potential diagnostic agent for its tumor to normal accumulation (T/N) ratio, which ranges from 2.3 to 24.5 from positron emission tomography, whereas the T/N ratio of FBPA is greater than 2.5. Additionally, in serving as a BNCT therapeutic agent, the boron concentration of FBY accumulated in gliomas remains uncertain. The solubility of 3-BPA is better than that of BPA, as evidenced by the cerebral dose of 3.4%ID/g vs. 2.2%ID/g, respectively. While the extraction route of d-BPA differs from that of BPA, an impressive T/N ratio of 6.9 vs. 1.5 is noted. [18F]FBPA, the most common clinical boron agent, facilitates the application of BPA in clinical BNCT. In addition to [18F]FBY, [18F] trifluoroborated nucleoside analog obtained through 1,3-dipolar cycloaddition shows marked tumoral uptake of 1.5%ID/g. Other examples using electrophilic and nucleophilic fluorination on the boron compounds are also reviewed, including diboronopinacolone phenylalanine and nonsteroidal anti-inflammatory agents.

18.
AAPS J ; 25(6): 97, 2023 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-37783946

RESUMEN

Ocrelizumab (OCREVUS®) is a humanized anti-CD20 monoclonal antibody approved for the treatment of adult patients with relapsing multiple sclerosis (RMS) and primary progressive multiple sclerosis (PPMS). Here, we discuss the strategic and technical considerations needed to develop a robust antibody-dependent cellular cytotoxicity (ADCC)-based neutralizing antibody (NAb) assay to detect anti-ocrelizumab NAb in patients enrolled in the ocrelizumab registered clinical trials. The NAb detection assay consisted of a two-tier assay that included a screening assay and a confirmation assay. In the screening assay, patient samples were analyzed in the presence of ocrelizumab. Samples that tested positive in the screening assay were subsequently analyzed in the confirmatory assay where another anti-CD20 mAb, obinutuzumab, was replaced by ocrelizumab, to verify NAb specificity. Both assays utilized MEC-2 cells, a chronic B cell leukemia cell line, pre-labeled with calcein AM as the target cells, and natural killer (NK) cells engineered to stably express Fc gamma receptor IIIa_ F158 as effector cells. Both cell lines were prepared to be thaw-and-use cells. The NAb assay measures fluorescence from the calcein AM released into the assay media upon the lysis of target cells by ADCC in the presence of ocrelizumab or obinutuzumab. Our validated NAb assay showed a relative sensitivity of 743 ng/mL and can detect 1500 ng/mL of a surrogate positive control antibody in the presence of 1500 ng/mL ocrelizumab. This ADCC assay is the first reported NAb assay that directly measures target cell lysis by using thaw-and-use target and effector cells simultaneously.


Asunto(s)
Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Adulto , Humanos , Fluoresceínas , Citotoxicidad Celular Dependiente de Anticuerpos
19.
Front Immunol ; 14: 1295285, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38022649

RESUMEN

Major histocompatibility complex (MHC)-Associated Peptide Proteomics (MAPPs) is an ex vivo method used to assess the immunogenicity risk of biotherapeutics. MAPPs can identify potential T-cell epitopes within the biotherapeutic molecule. Using adalimumab treated human monocyte derived dendritic cells (DCs) and a pan anti-HLA-DR antibody (Ab), we systematically automated and optimized biotin/streptavidin (SA)-capture antibody coupling, lysate incubation with capture antibody, as well as the washing and elution steps of a MAPPs method using functionalized magnetic beads and a KingFisher Magnetic Particle processor. Automation of these steps, combined with capturing using biotinylated-Ab/SA magnetic beads rather than covalently bound antibody, improved reproducibility as measured by minimal inter-and intra-day variability, as well as minimal analyst-to-analyst variability. The semi-automated MAPPs workflow improved sensitivity, allowing for a lower number of cells per analysis. The method was assessed using five different biotherapeutics with varying immunogenicity rates ranging from 0.1 to 48% ADA incidence in the clinic. Biotherapeutics with ≥10%immunogenicity incidence consistently presented more peptides (1.8-28 fold) and clusters (10-21 fold) compared to those with <10% immunogenicity incidence. Our semi-automated MAPPs method provided two main advantages over a manual workflow- the robustness and reproducibility affords confidence in the epitopes identified from as few as 5 to 10 donors and the method workflow can be readily adapted to incorporate different capture Abs in addition to anti-HLA-DR. The incorporation of semi-automated MAPPs with biotinylated-Ab/SA bead-based capture in immunogenicity screening strategies allows the generation of more consistent and reliable data, helping to improve immunogenicity prediction capabilities in drug development. MHC associated peptide proteomics (MAPPs), Immunogenicity risk assessment, in vitro/ex vivo, biotherapeutics, Major Histocompatibility Complex Class II (MHC II), LC-MS, Immunoaffinity Capture, streptavidin magnetic beads.


Asunto(s)
Proteómica , Espectrometría de Masas en Tándem , Humanos , Estreptavidina , Reproducibilidad de los Resultados , Péptidos/metabolismo , Anticuerpos , Epítopos de Linfocito T , Desarrollo de Medicamentos
20.
Tzu Chi Med J ; 35(1): 38-43, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36866342

RESUMEN

Resource recycling has become an integral part of environmental protection efforts. At present, the development of Taiwan's resource recovery and related works are quite mature. However, laborers or volunteers working in resource recycling stations may be exposed to different types of hazards during the recycling process. These hazards can be divided into biological, chemical, and musculoskeletal problems. These hazards are usually related to the work environment and work habits; therefore, a related control strategy is needed. Tzu Chi's recycling business has been running for over 30 years. In addition to leading the trend of resource recycling in Taiwan, many elderly people have also participated in Tzu Chi recycling stations as volunteers. These older volunteers may be more sensitive to exposure to hazards, and thus the focus of this review is to illustrate the possible hazards and health impacts of resource recovery work and to recommend relevant interventions to improve occupational health during resource recovery work.

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