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1.
Med Devices (Auckl) ; 15: 277-283, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36003611

RESUMEN

Background: Cold plasma has many characteristics that allow for effective wound healing. Due to its efficacy, we have applied it in treating patients with severe Covid-19 who have soft tissue skin lesions and diseases including burns, pressure ulcers, shingles, and contact or atopic dermatitis. This study aims to assess the general characteristics of Covid-19 patients with soft tissue lesions and to conduct a fundamental evaluation of the efficacy of cold plasmamed beams in treating soft tissue wounds in patients with severe Covid-19. Methods: This prospective study was conducted on 20 severe Covid-19 patients with soft tissue lesions at the Intensive Care Center for Covid-19 of Hue Central Hospital in Ho Chi Minh City from September 25 to November 11, 2021. These patients was performed cold plasma irradiation at any stage of wound progression, including new injuries and chronic wounds. Results: Among 915 severe Covid-19 patients treated at our center, 20 patients had soft tissue lesions. Grade I, II, and III pressure ulcers accounted for 70% of the 20 cases of soft tissue lesions and 1.53% of the total patients at the time of the survey. Pressure ulcers were present in only 0.55% of patients (5/915 patients). Eleven out of 20 patients (55.0%) had lesions before admission, and 9 (45.0%) had lesions that appeared after admission. After 14 days of treatment, 14/20 patients had complete epithelialization (70%), and in 18/20 patients, wound exudation had ceased. The wounds became painless; after 3 weeks, the rashes had completely disappeared. Conclusion: The study emphasizes that irradiation with cold plasma contributes to the wound healing process.

2.
Dalton Trans ; 50(29): 10067-10081, 2021 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-34195731

RESUMEN

Neutral and ionic ruthenium and iron aliphatic PNHP-type pincer complexes (PNHP = NH(CH2CH2PiPr2)2) bearing benzyl, n-butyl or tert-butyl isocyanide ancillary ligands have been prepared and characterized. Reaction of [RuCl2(PNHP)]2 with one equivalent CN-R per ruthenium center affords complexes [RuCl2(PNHP)(CNR)] (R = benzyl, 1a, R = n-butyl, 1b, R = t-butyl, 1c), with cationic [RuCl(PNHP)(CNR)2]Cl 2a-c as side-products. Dichloride species 1a-c react with excess NaBH4 to afford [RuH(PNHP)(BH4)(CN-R)] 3a-c, analogues to benchmark Takasago catalyst [RuH(PNHP)(BH4)(CO)]. Reaction of 1a-c with a single equivalent of NaBH4 results in formation of [RuHCl(PNHP) (CN-R)] (4a-c), from which 3a-c can be prepared upon reaction with excess NaBH4. Use of one equivalent of NaHBEt3 with 4a and 4c affords bishydrides [Ru(H)2(PNHP)(CN-R)] 5a and 5c. Deprotonation of 4c by KOtBu generates amido derivative [RuH(PNP)(CN-t-Bu)] (6, PNP = -N(CH2CH2PiPr2)2), unstable in solution. Addition of excess benzylisonitrile to 4a provides cationic hydride [RuH(PNHP) (CN-CH2Ph)2]Cl (7). Concerning iron chemistry, [Fe(PNHP)Br2] reacts with one equivalent of benzylisonitrile to afford [FeBr(PNHP)(CNCH2Ph)2]Br (8). The outer-sphere bromide anion can be exchanged by salt metathesis with NaBPh4 to generate [FeBr(PNHP) (CNCH2Ph)2](BPh4) (9). Cationic hydride species [FeH(PNHP) (CN-t-Bu)2](BH4) (10) is prepared from consecutive addition of excess CN-t-Bu and NaBH4 on [Fe(PNPH)Br2]. Ruthenium complexes 3a-c are active in acceptorless alcohol dehydrogenative coupling into ester under base-free conditions. From kinetic follow-up, the trend in initial activity is 3a ≈ 3b > [RuH(PNHP)(BH4)(CO)] ≫ 3c; for robustness, [RuH(BH4)(CO)(PNHP)] > 3a > 3b ≫ 3c. Hypotheses are given to account for the observed deactivation. Complexes 3b, 3c, 4a, 4c, 5c, 7, cis-8 and 9 were characterized by X-ray crystallography.

3.
Molecules ; 26(12)2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34203624

RESUMEN

Millettia pulchra is traditionally used for treating diseases, including joint pain, fever, anemia, and allergies. It is also a potential resource of natural flavonoid derivatives, which represents major constituents of this plant. This study aimed to isolate the major compounds from M. pulchra radix, develop and validate the HPLC-PDA method to determine their contents, and optimize its extraction. Four major flavonoid derivatives (karanjin, lanceolatin B, 2",2"-dimethylpyrano-[5″,6″:7,8]-flavone, and pongamol) were isolated using silica gel column chromatography, crystallization techniques in large amounts with high purities (>95%). A simple, accurate high-performance liquid chromatography-photodiode array (HPLC-PDA) detection method has been developed and validated with significantly statistical impacts according to International Conference on Harmonization (ICH) guidelines. The Response Surface Methodology (RSM), Artificial Neural Network (ANN) models were employed to predictive performance and optimization of the extraction process. The optimized conditions for the extraction of major flavonoids were: extraction time (twice), solvent/material ratio (9.5), and ethanol concentration (72.5%). Our research suggests an effective method, which will be helpful for quality control in the pharmaceutical development of this species.


Asunto(s)
Flavonoides/química , Flavonoides/aislamiento & purificación , Millettia/química , Antioxidantes/química , China , Cromatografía Líquida de Alta Presión/métodos , Etanol/química , Millettia/metabolismo , Extractos Vegetales/química , Raíces de Plantas/química , Solventes/química
4.
Methods ; 154: 38-50, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30366098

RESUMEN

Bispecific monoclonal antibodies can bind two protein targets simultaneously and enable therapeutic modalities inaccessible by traditional mAbs. Bispecific formats containing a heterodimeric Fc region are of particular interest, as a heterodimeric Fc empowers both bispecificity and altered valencies while retaining the developability and druggability of a monoclonal antibody. We present a robust heterodimeric Fc platform, called the XmAb® bispecific platform, engineered for efficient development of bispecific antibodies and Fc fusions of multiple formats. First, we engineer a purification solution for proteins containing a heterodimeric Fc using engineered isoelectric point differences in the Fc region that enable straightforward purification of the heterodimeric species. Then, we combine this purification solution with a novel set of Fc substitutions capable of achieving heterodimer yields over 95% with little change in thermostability. Next, we illustrate the flexibility of our heterodimeric Fc with a case study in which a wide range of tumor-associated antigen × CD3 bispecifics are generated, differing in choice of tumor antigen, affinities for both tumor antigen and CD3, and tumor antigen valency. Finally, we present manufacturing data reinforcing the robustness of the heterodimeric Fc platform at scale.


Asunto(s)
Anticuerpos Biespecíficos , Anticuerpos Monoclonales , Ingeniería de Proteínas/métodos , Antígenos de Neoplasias/inmunología , Complejo CD3/inmunología , Humanos
5.
Eur Phys J E Soft Matter ; 41(4): 50, 2018 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-29644548

RESUMEN

We investigate sheared granular materials composed of crushable particles by means of contact dynamics simulations and the bonded-cell model for particle breakage. Each particle is paved by irregular cells interacting via cohesive forces. In each simulation, the ratio of the internal cohesion of particles to the confining pressure, the relative cohesion, is kept constant and the packing is subjected to biaxial shearing. The particles can break into two or more fragments when the internal cohesive forces are overcome by the action of compressive force chains between particles. The particle size distribution evolves during shear as the particles continue to break. We find that the breakage process is highly inhomogeneous both in the fragment sizes and their locations inside the packing. In particular, a number of large particles never break whereas a large number of particles are fully shattered. As a result, the packing keeps the memory of its initial particle size distribution, whereas a power-law distribution is observed for particles of intermediate size due to consecutive fragmentation events whereby the memory of the initial state is lost. Due to growing polydispersity, dense shear bands are formed inside the packings and the usual dilatant behavior is reduced or cancelled. Hence, the stress-strain curve no longer passes through a peak stress, and a progressive monotonic evolution towards a pseudo-steady state is observed instead. We find that the crushing rate is controlled by the confining pressure. We also show that the shear strength of the packing is well expressed in terms of contact anisotropies and force anisotropies. The force anisotropy increases while the contact orientation anisotropy declines for increasing internal cohesion of the particles. These two effects compensate each other so that the shear strength is nearly independent of the internal cohesion of particles.

6.
ChemSusChem ; 9(12): 1413-23, 2016 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-27115079

RESUMEN

The catalytic conversion of alcohols into carboxylic acid salts in water was performed in the presence of ruthenium complexes supported by aliphatic PNP pincer ligands preformed or formed in situ. High activity toward a wide substrate scope was achieved with turnover number values of up to 4000. The air-stable catalytic system can be recycled by using toluene as a catalyst-immobilizing phase; the activity is maintained after five consecutive runs. Finally, mechanistic studies allowed some fundamental aspects related to water activation to be unveiled and to the mechanism postulated.


Asunto(s)
Alcoholes/química , Ácidos Carboxílicos/química , Reciclaje , Sales (Química)/química , Agua/química , Catálisis , Hidrogenación , Rutenio/química
7.
Chemistry ; 21(44): 15607-21, 2015 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-26368361

RESUMEN

Access to hydroxy-functionalized P-chiral phosphine-boranes has become an important field in the synthesis of P-stereogenic compounds used as ligands in asymmetric catalysis. A family of optically pure α and ß-hydroxyalkyl tertiary phosphine-boranes has been prepared by using a three-step procedure from readily accessible enantiopure adamantylphosphinate, obtained by semi-preparative HPLC on multigram scale. Firstly, a two-step one-pot transformation affords the enantiopure hydroxyalkyl tertiary phosphine oxides in good yields and enantioselectivities. The third step, BH3 -mediated reduction, allows the formation of the desired phosphine-boranes with excellent stereospecifity. The mechanistic study of this reduction provides new evidence to elucidate the crucial role of the pendant hydroxy group and the subsequent activation of the P=O bond by the boron atom.

8.
Artículo en Inglés | MEDLINE | ID: mdl-25871099

RESUMEN

By means of extensive contact dynamics simulations, we analyze the combined effects of polydispersity both in particle size and in particle shape, defined as the degree of shape irregularity, on the shear strength and microstructure of sheared granular materials composed of pentagonal particles. We find that the shear strength is independent of the size span, but unexpectedly, it declines with increasing shape polydispersity. At the same time, the solid fraction is an increasing function of both the size span and the shape polydispersity. Hence, the densest and loosest packings have the same shear strength. At the scale of the particles and their contacts, we analyze the connectivity of particles, force transmission, and friction mobilization as well as their anisotropies. We show that stronger forces are carried by larger particles and propped by an increasing number of small particles. The independence of shear strength with regard to size span is shown to be a consequence of contact network self-organization, with the falloff of contact anisotropy compensated by increasing force anisotropy.

9.
J Org Chem ; 80(8): 4132-41, 2015 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-25806668

RESUMEN

A new family of H-adamantylphosphinates as universal precursors of P-stereogenic ligands was obtained in one step from commercial chlorophosphines. Both enantiomers of these air- and moisture-stable intermediates can easily be separated by semipreparative chiral HPLC on a gram scale and individually undergo stereoselective transformations to afford each enantiomer of a set of P-stereogenic compounds such as secondary phosphine oxides and boron-protected monophosphines.

10.
Artículo en Inglés | MEDLINE | ID: mdl-25768494

RESUMEN

Particle degradation and fracture play an important role in natural granular flows and in many applications of granular materials. We analyze the fracture properties of two-dimensional disklike particles modeled as aggregates of rigid cells bonded along their sides by a cohesive Mohr-Coulomb law and simulated by the contact dynamics method. We show that the compressive strength scales with tensile strength between cells but depends also on the friction coefficient and a parameter describing cell shape distribution. The statistical scatter of compressive strength is well described by the Weibull distribution function with a shape parameter varying from 6 to 10 depending on cell shape distribution. We show that this distribution may be understood in terms of percolating critical intercellular contacts. We propose a random-walk model of critical contacts that leads to particle size dependence of the compressive strength in good agreement with our simulation data.

11.
Chem Soc Rev ; 44(8): 2508-28, 2015 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-25714261

RESUMEN

Achiral or chiral phosphines are widely used in two main domains: ligands in organometallic catalysis and organocatalysis. For this reason, the obtention of optically pure phosphine has always been challenging in the development of asymmetric catalysis. The simplest method to obtain phosphines is the reduction of phosphine oxides. The essential difficulty is the strength of the P=O bond which involves new procedures to maintain a high chemio- and stereoselectivity. The reduction can occur with retention or inversion of the stereogenic phosphorus atom depending on the nature of the reducing agent and the presence of additives. In fact, the reactivity of the phosphine oxides and the mechanism of the reduction are not always well understood. Since the first work in the 1950's, numerous studies have been realised in order to develop methodologies with different reagents or to understand the mechanism of the reaction. In the last decade, efficient stereospecific methodologies have been developed to obtain optically pure tertiary phosphines from P-stereogenic phosphine oxides. In this review, we intend to provide a comprehensive and critical overview of these methodologies.


Asunto(s)
Óxidos/química , Fosfinas/química , Indicadores y Reactivos/química , Oxidación-Reducción
12.
Artículo en Inglés | MEDLINE | ID: mdl-25122294

RESUMEN

We present a detailed analysis of the morphology of granular systems composed of frictionless pentagonal particles by varying systematically both the size span and particle shape irregularity, which represent two polydispersity parameters of the system. The microstructure is characterized in terms of various statistical descriptors such as global and local packing fractions, radial distribution functions, coordination number, and fraction of floating particles. We find that the packing fraction increases with the two parameters of polydispersity, but the effect of shape polydispersity for all the investigated structural properties is significant only at low size polydispersity where the positional and/or orientational ordering of the particles prevail. We focus in more detail on the class of side/side contacts, which is the interesting feature of our system as compared to a packing of disks. We show that the proportion of such contacts has weak dependence on the polydispersity parameters. The side- side contacts do not percolate but they define clusters of increasing size as a function of size polydispersity and decreasing size as a function of shape polydispersity. The clusters have anisotropic shapes but with a decreasing aspect ratio as polydispersity increases. This feature is argued to be a consequence of strong force chains (forces above the mean), which are mainly captured by side-side contacts. Finally, the force transmission is intrinsically multiscale, with a mean force increasing linearly with particle size.


Asunto(s)
Modelos Teóricos , Tamaño de la Partícula , Movimiento (Física)
13.
Dalton Trans ; 42(1): 75-81, 2013 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-23132099

RESUMEN

Using the unsymmetrical P-P' phospholyl(phosphino)methane ligand, complex cis-[RuCl(2)(κ(2)-P-P')(2)] is easily prepared from [RuCl(2)(DMSO)(4)]. The two phosphole-phosphorus atoms lie in the trans position to the two cis-chloro ligands. This complex slowly isomerizes spontaneously at 20 °C to the trans-[RuCl(2)(κ(2)-P-P')(2)] diastereoisomer where the two phosphole moieties are mutually trans, as well as the two chloro ligands and the two Ph(2)P moieties. DFT calculations show that this non-classical cis-trans isomerisation process requires a 3 kcal mol(-1) energy and involves the decoordination of a phosphole arm.


Asunto(s)
Complejos de Coordinación/química , Metano/química , Compuestos Organofosforados/química , Rutenio/química , Cristalografía por Rayos X , Dimetilsulfóxido/química , Isomerismo , Ligandos , Conformación Molecular
14.
Inorg Chem ; 51(16): 8670-85, 2012 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-22845464

RESUMEN

The neutral rhodium(I) square-planar complexes [RhX(CO)(2)(L)] [X = Cl (3), I (4)] bearing a nitrogen-containing ligand L [diethylamine (a), triethylamine (b), imidazole (c), 1-methylimidazole (d), pyrazole (e), 1-methylpyrazole (f), 3,5-dimethylpyrazole (g)] are straightforwardly obtained from L and [Rh(µ-X)(CO)(2)](2) [X = Cl (1), I (2)] precursors. The synthesis is extended to the diethylsulfide ligand h for 3h and 4h. According to the CO stretching frequency of 3 and 4, the ranking of the electronic density on the rhodium center follows the order b > a ≈ d > c > g > f ≈ h > e. The X-ray molecular structures of 3a, 3d-3f, 4a, and 4d-4f were determined. Results from variable-temperature (1)H and (13)C{(1)H} NMR experiments suggest a fluxional associative ligand exchange for 4c-4h and a supplementary hydrogen-exchange process in 4e and 4g. The oxidative addition reaction of CH(3)I to complexes 4c-4g affords the neutral dimeric iodo-bridged acetylrhodium(III) complexes [RhI(µ-I)(COCH(3))(CO)(L)](2) (6c-6g) in very good isolated yields, whereas 4a gives a mixture of neutral 6a and dianionic [RhI(2)(µ-I)(COCH(3))(CO)][NHMeEt(2)](2) and 4h exclusively provides the analogue dianionic complex with [SMeEt(2)](+) as the counterion. X-ray molecular structures for 6d(2) and 6e reveal that the two apical CO ligands are in mutual cis positions, as are the two apical d and e ligands, whereas isomer 6d(1) is centrosymmetric. Further reactions of 6d and 6e with CO or ligand e gave quantitatively the monomeric complexes [RhI(2)(COCH(3))(CO)(2)(d)] (7d) and [RhI(2)(COCH(3))(CO)(e)(2)] (8e), respectively, as confirmed by their X-ray structures. The initial rate of CH(3)I oxidative addition to 4 as determined by IR monitoring is dependent on the nature of the nitrogen-containing ligand. For 4a and 4h, reaction rates similar to those of the well-known rhodium anionic [RhI(2)(CO)(2)](-) species are observed and are consistent with the formation of this intermediate species through methylation of the a and h ligands. The reaction rates are reduced significantly when using imidazole and pyrazole ligands and involve the direct oxidative addition of CH(3)I to the neutral complexes 4c-4g. Complexes 4c and 4d react around 5-10 times faster than 4e-4g mainly because of electronic effects. The lowest reactivity of 4f toward CH(3)I is attributed to the steric effect of the coordinated ligand, as supported by the X-ray structure.

15.
J Allergy Clin Immunol ; 129(4): 1102-15, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22257644

RESUMEN

BACKGROUND: Sequestration of IgE to prevent its binding to high-affinity IgE receptor FcεRI on basophils and mast cells is an effective therapy for allergic asthma. IgE production requires differentiation of activated IgE(+) B cells into plasma cells upon allergen sensitization. B-cell receptor signaling is suppressed by the inhibitory IgG Fc receptor FcγRIIb; therefore, we reasoned that a therapeutic antibody that coengages FcγRIIb and IgE B-cell receptor would not only sequester IgE but also suppress its production by blocking IgE(+) B-cell activation and differentiation to IgE-secreting plasma cells. OBJECTIVE: To explore the effects of IgE sequestration versus IgE suppression by comparing omalizumab to FcγRIIb-optimized anti-IgE antibodies in humanized mouse models of immunoglobulin production. METHODS: By using a murine anti-IgE antibody as a template, we humanized, increased IgE binding, and modified its Fc domain to increase affinity for FcγRIIb. We next compared effects of this antibody (XmAb7195) versus omalizumab on the secretion of IgE and other isotypes in human PBMC cultures and in PBMC-engrafted severe combined immunodeficiency mice. RESULTS: Relative to omalizumab, XmAb7195 has a 5-fold higher affinity for human IgE and more than 400-fold higher affinity for FcγRIIb. In addition to sequestering soluble IgE, XmAb7195 inhibited plasma cell differentiation and consequent human IgE production through coengagement of IgE B-cell receptor with FcγRIIb. In PBMC-engrafted mice, XmAb7195 reduced total human IgE (but not IgG or IgM) levels by up to 40-fold relative to omalizumab. CONCLUSION: XmAb7195 acts by IgE sequestration coupled with an FcγRIIb-mediated inhibitory mechanism to suppress the formation of IgE-secreting plasma cells and reduce both free and total IgE levels.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacología , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Inmunoglobulina E/biosíntesis , Receptores de Antígenos de Linfocitos B/antagonistas & inhibidores , Receptores de IgE/antagonistas & inhibidores , Receptores de IgG/antagonistas & inhibidores , Animales , Antialérgicos/farmacología , Anticuerpos Antiidiotipos/sangre , Anticuerpos Antiidiotipos/inmunología , Anticuerpos Antiidiotipos/farmacología , Anticuerpos Monoclonales Humanizados/sangre , Anticuerpos Monoclonales Humanizados/genética , Afinidad de Anticuerpos/inmunología , Humanos , Inmunoglobulina E/metabolismo , Fragmentos Fc de Inmunoglobulinas/genética , Inmunoglobulina G/biosíntesis , Inmunoglobulina G/sangre , Inmunoglobulina M/biosíntesis , Inmunoglobulina M/sangre , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/trasplante , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones SCID , Omalizumab , Unión Proteica/inmunología , Receptores de Antígenos de Linfocitos B/metabolismo , Receptores de IgE/metabolismo , Receptores de IgG/genética , Receptores de IgG/metabolismo
16.
Blood ; 119(9): 2074-82, 2012 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-22246035

RESUMEN

HM1.24, an immunologic target for multiple myeloma (MM) cells, has not been effectively targeted with therapeutic monoclonal antibodies (mAbs). In this study, we investigated in vitro and in vivo anti-MM activities of XmAb5592, a humanized anti-HM1.24 mAb with Fc-domain engineered to significantly enhance FcγR binding and associated immune effector functions. XmAb5592 increased antibody-dependent cellular cytotoxicity (ADCC) several fold relative to the anti-HM1.24 IgG1 analog against both MM cell lines and primary patient myeloma cells. XmAb5592 also augmented antibody dependent cellular phagocytosis (ADCP) by macrophages. Natural killer (NK) cells became more activated by XmAb5592 than the IgG1 analog, evidenced by increased cell surface expression of granzyme B-dependent CD107a and MM cell lysis, even in the presence of bone marrow stromal cells. XmAb5592 potently inhibited tumor growth in mice bearing human MM xenografts via FcγR-dependent mechanisms, and was significantly more effective than the IgG1 analog. Lenalidomide synergistically enhanced in vitro ADCC against MM cells and in vivo tumor inhibition induced by XmAb5592. A single dose of 20 mg/kg XmAb5592 effectively depleted both blood and bone marrow plasma cells in cynomolgus monkeys. These results support clinical development of XmAb5592, both as a monotherapy and in combination with lenalidomide, to improve patient outcome of MM.


Asunto(s)
Anticuerpos Monoclonales Humanizados/inmunología , Antígenos CD/inmunología , Fragmentos Fc de Inmunoglobulinas/inmunología , Mieloma Múltiple/terapia , Animales , Anticuerpos Monoclonales Humanizados/administración & dosificación , Citotoxicidad Celular Dependiente de Anticuerpos/efectos de los fármacos , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Degranulación de la Célula , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Técnicas de Cocultivo , Sinergismo Farmacológico , Femenino , Proteínas Ligadas a GPI/inmunología , Humanos , Células Asesinas Naturales/inmunología , Lenalidomida , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/inmunología , Depleción Linfocítica , Macaca fascicularis , Ratones , Ratones SCID , Fagocitosis/efectos de los fármacos , Fagocitosis/inmunología , Células Plasmáticas/efectos de los fármacos , Células Plasmáticas/inmunología , Talidomida/administración & dosificación , Talidomida/análogos & derivados , Talidomida/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
17.
Inorg Chem ; 51(1): 4-6, 2012 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-22122231

RESUMEN

For the last step of rhodium-catalyzed methanol carbonylation, high-pressure NMR, and kinetic and experimental data supported by density functional theory calculations are consistent with substitution of I(-) by an AcO(-) ligand on the [RhI(3)(COCH(3))(CO)(2)](-) species followed by reductive elimination of acetic anhydride, which immediately reacts with water to afford acetic acid.

18.
MAbs ; 3(6): 546-57, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22123055

RESUMEN

Bispecific antibodies based on full-length antibody structures are more optimal than fragment-based formats because they benefit from the favorable properties of the Fc region. However, the homodimeric nature of Fc effectively imposes bivalent binding on all current full-length bispecific antibodies, an attribute that can result in nonspecific activation of cross-linked receptors. We engineered a novel bispecific format, referred to as mAb-Fv, that utilizes a heterodimeric Fc region to enable monovalent co-engagement of a second target antigen in a full-length context. mAb-Fv constructs co-targeting CD16 and CD3 were expressed and purified as heterodimeric species, bound selectively to their co-target antigens, and mediated potent cytotoxic activity by NK cells and T cells, respectively. The capacity to co-engage distinct target antigens simultaneously with different valencies is an improved feature for bispecific antibodies with promising therapeutic implications.


Asunto(s)
Anticuerpos Biespecíficos/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Complejo CD3/inmunología , Fragmentos Fc de Inmunoglobulinas/inmunología , Fragmentos de Inmunoglobulinas/inmunología , Receptores de IgG/inmunología , Animales , Anticuerpos Biespecíficos/química , Anticuerpos Biespecíficos/genética , Anticuerpos Biespecíficos/metabolismo , Complejo CD3/genética , Complejo CD3/metabolismo , Dimerización , Células HEK293 , Humanos , Fragmentos Fc de Inmunoglobulinas/química , Fragmentos Fc de Inmunoglobulinas/genética , Fragmentos Fc de Inmunoglobulinas/metabolismo , Fragmentos de Inmunoglobulinas/química , Fragmentos de Inmunoglobulinas/genética , Fragmentos de Inmunoglobulinas/metabolismo , Células Asesinas Naturales/inmunología , Ratones , Modelos Moleculares , Ingeniería de Proteínas/métodos , Receptores de IgG/genética , Receptores de IgG/metabolismo , Linfocitos T/inmunología
19.
Dalton Trans ; 40(33): 8429-35, 2011 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-21776507

RESUMEN

Unsaturated σ,π-cyclooctenyl and hydrido Ir(III) complexes bearing an unusual tridentate dianionic ONO pincer-type ligand have been straightforwardly obtained from 2,6-pyridinedicarboxylic acid and standard Ir(I) starting materials. These complexes efficiently catalyzed the arene C-H borylation under thermal conditions.

20.
J Mol Biol ; 396(5): 1474-90, 2010 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-20045416

RESUMEN

Fully human monoclonal antibodies (mAbs) derived from transgenic mice or human antibody libraries are the current state of the art for reducing the immunogenicity risk of antibody drugs. Here, we describe a novel method for generating fully human mAbs from nonhuman variable regions using information from the human germline repertoire. Central to our strategy is the rational engineering of residues within and proximal to CDRs and the V(H)/V(L) interface by iteratively exploring substitutions to the closest human germline sequences using semi-automated computational methods. Starting from the parent murine variable regions of three currently marketed mAbs targeting CD25, vascular endothelial growth factor, and tumor necrosis factor alpha, we have generated fully human antibodies with 59, 46, and 45 substitutions, respectively, compared to the parent murine sequences. A large number of these substitutions were in the CDRs, which are typically avoided in humanization methods. Antigen affinities of the fully human variants were comparable to the chimeric mAbs in each case. Furthermore, in vitro functional characterization indicated that all retain potency of the chimeric mAbs and have comparable activity to their respective marketed drugs daclizumab, bevacizumab, and infliximab. Based on local and global sequence identity, the sequences of our engineered mAbs are indistinguishable from those of fully human mAbs isolated from transgenic mice or human antibody libraries. This work establishes a simple rational engineering methodology for generating fully human antibody therapeutics from murine mAbs produced from standard hybridoma technology.


Asunto(s)
Anticuerpos Monoclonales/genética , Región Variable de Inmunoglobulina/genética , Ingeniería de Proteínas/métodos , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Células Cultivadas , Regiones Determinantes de Complementariedad/genética , Humanos , Técnicas In Vitro , Subunidad alfa del Receptor de Interleucina-2/antagonistas & inhibidores , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Biblioteca de Péptidos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Linfocitos T/inmunología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores
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