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1.
Infect Prev Pract ; 6(3): 100380, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39044941

RESUMEN

Background: Meropenem (MEPM) holds significance in treating severe infections and drug-resistant bacteria. There are concerns that antimicrobial shortages may lead to the use of alternative antimicrobials that are less effective and safer. We have responded to the MEPM shortage with post-prescription monitoring and feedback (PPRF) with no restrictions on MEPM initiation. We aimed to assess the impact of the MEPM shortage and the PPRF on broad-spectrum antimicrobial use and mortality. Methods: This retrospective study was conducted in a single hospital in Japan. The period from October 2021 to August 2022 was defined as the period before the MEPM shortage, and the period from September 2022 to March 2023 was defined as the period during the MEPM shortage. To support the appropriate use of antimicrobials during MEPM shortages, the antimicrobial stewardship team (AST) developed a list of alternatives to MEPM. An interrupted time series analysis was used to assess changes in use and mortality among patients receiving broad-spectrum antimicrobials over the study period. Discussion: The shortage of MEPM and PPRF temporarily increased the use of alternative cefepime; however, the subsequent change in days of therapy and days of coverage of broad-spectrum antimicrobials suggests a decrease in the use of these antimicrobials. Despite these shifts, the mortality rates remained stable, suggesting that the response to the shortage did not adversely affect treatment outcomes. Conclusion: In the context of antimicrobial shortages, AST support plays an important role in enabling physicians to make optimal use of antimicrobials.

2.
ACS Omega ; 9(12): 14142-14152, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38559978

RESUMEN

A switch of reaction medium from organic solvents to water can improve the safety and lower the cost of production processes. Hydrochloric acid-promoted amination of fused pyrimidines has been studied using 4-chloro-7H-pyrrolo[2,3-d]pyrimidine and aniline as model compounds. Higher rate was observed in water than in four alcoholic solvents and DMF. An important aspect is that the amount of acid should be kept low to minimize the competing solvolysis. The substrate scope for the amination in water was evaluated by reacting 4-chloro-7H-pyrrolo[2,3-d]pyrimidine with 20 aniline derivatives with variance in steric and electronic properties. Preparative useful reactions were seen for 14 of the 20 derivatives. Unsuited nucleophiles are ortho-substituted anilines with a pKa below 1. Amination of the corresponding quinazoline, thienopyrimidine, and purine also proceeded well in water. Highly lipophilic and crystalline compounds are more efficiently aminated in 2-propanol. Aliphatic and benzylic amines react poorly under acidic conditions, but these aminations can be done in water without acid.

3.
Nat Commun ; 15(1): 512, 2024 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-38218949

RESUMEN

Tuning CO2 hydrogenation product distribution to obtain high-selectivity target products is of great significance. However, due to the imprecise regulation of chain propagation and hydrogenation reactions, the oriented synthesis of a single product is challenging. Herein, we report an approach to controlling multiple sites with graphene fence engineering that enables direct conversion of CO2/H2 mixtures into different types of hydrocarbons. Fe-Co active sites on the graphene fence surface present 50.1% light olefin selectivity, while the spatial Fe-Co nanoparticles separated by graphene fences achieve liquefied petroleum gas of 43.6%. With the assistance of graphene fences, iron carbides and metallic cobalt can efficiently regulate C-C coupling and olefin secondary hydrogenation reactions to achieve product-selective switching between light olefins and liquefied petroleum gas. Furthermore, it also creates a precedent for CO2 direct hydrogenation to liquefied petroleum gas via a Fischer-Tropsch pathway with the highest space-time yields compared to other reported composite catalysts.

4.
Jpn J Infect Dis ; 76(5): 282-288, 2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37258175

RESUMEN

In COVID-19 patients who are immunocompromised or have severe COVID-19, the duration of infectious viral shedding may be longer, and a longer isolation duration is recommended. At the National Sagamihara Hospital, a decline in the viral load to end the isolation of hospitalized patients with COVID-19 was confirmed using loop-mediated isothermal amplification (LAMP). However, a subset of patients displayed LAMP positivity for more than 20 days after symptom onset. Therefore, we conducted a retrospective observational study to investigate the factors that affect the persistence of LAMP positivity. This study included a total of 102 participants. The severity of COVID-19 was mild (25.5%), moderate (67.6%), or severe (6.9%). The median number (interquartile range) of days until negative LAMP results from symptom onset were 16 (14-19) days. Multivariate logistic regression analysis showed that patients ≥55 years and/or those with the delta variant were correlated with persistent LAMP positivity for more than 20 days after symptom onset. This study identified age, the delta variant, and oxygen requirement as factors that contribute to persistently positive LAMP results. Therefore, it is posited that in these patients, the implementation of LAMP for deisolation would result in a prolonged isolation duration.


Asunto(s)
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2/genética , Pacientes Internos , Prueba de COVID-19 , Técnicas de Laboratorio Clínico/métodos , Sensibilidad y Especificidad , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , ARN Viral/análisis
5.
Chemistry ; 29(40): e202301135, 2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37160742

RESUMEN

Even though the direct hydrogenation of CO2 into aromatics has been realized via a methanol-mediated pathway and multifunctional catalyst, few works have been focused on the simultaneously rational design of each component in multifunctional catalyst to improve the performance. Also, the structure-function relationship between aromatics synthesis performance and the different catalytic components (reducible metal oxide and acidic zeolite) has been rarely investigated. Herein, we increase the oxygen vacancy (Ov ) density in reducible Cr2 O3 by sequential carbonization and oxidation (SCO) treatments of Cr-based metal-organic frameworks. Thanks to the enriched Ov , Cr2 O3 -based catalyst affords high methanol selectivity of 98.1 % (without CO) at a CO2 conversion of 16.8 % under high reaction temperature (350 °C). Furthermore, after combining with the acidic zeolite H-ZSM-5, the multifunctional catalyst realizes the direct conversion of CO2 into aromatics with conversion and selectivity as high as 25.4 % and 80.1 % (without CO), respectively. The property of acid site in H-ZSM-5, especially the Al species that located at the intersection of straight and sinusoidal channels, plays a vital role in enhancing the aromatics selectivity, which can be precisely controlled by varying the hydrothermal synthesis conditions. Our work provides a synergistic strategy to boost the aromatics synthesis performance from CO2 hydrogenation.

6.
Sci Adv ; 8(32): eadc9115, 2022 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-35947708

RESUMEN

While dye-sensitized metal oxides are good candidates as H2 evolution photocatalysts for solar-driven Z-scheme water splitting, their solar-to-hydrogen (STH) energy conversion efficiencies remain low because of uncontrolled charge recombination reactions. Here, we show that modification of Ru dye-sensitized, Pt-intercalated HCa2Nb3O10 nanosheets (Ru/Pt/HCa2Nb3O10) with both amorphous Al2O3 and poly(styrenesulfonate) (PSS) improves the STH efficiency of Z-scheme overall water splitting by a factor of ~100, when the nanosheets are used in combination with a WO3-based O2 evolution photocatalyst and an I3-/I- redox mediator, relative to an analogous system that uses unmodified Ru/Pt/HCa2Nb3O10. By using the optimized photocatalyst, PSS/Ru/Al2O3/Pt/HCa2Nb3O10, a maximum STH of 0.12% and an apparent quantum yield of 4.1% at 420 nm were obtained, by far the highest among dye-sensitized water splitting systems and comparable to conventional semiconductor-based suspended particulate photocatalyst systems.

7.
Chemistry ; 28(43): e202200875, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35622449

RESUMEN

Pb2 Ti2 O5.4 F1.2 modified with various metal cocatalysts was studied as a photocatalyst for visible-light H2 evolution. Although unmodified Pb2 Ti2 O5.4 F1.2 showed negligible activity, modification of its surface with Rh led to the best observed promotional effect among the Pb2 Ti2 O5.4 F1.2 samples modified with a single metal cocatalyst. The H2 evolution activity was further enhanced by coloading with Pd; the Rh-Pd/Pb2 Ti2 O5.4 F1.2 photocatalyst showed 3.2 times greater activity than the previously reported Pt/Pb2 Ti2 O5.4 F1.2 . X-ray absorption fine-structure spectroscopy, photoelectrochemical, and transient absorption spectroscopy measurements indicated that the coloaded Rh and Pd species, which were partially alloyed on the Pb2 Ti2 O5.4 F1.2 surface, improved the electron-capturing ability, thereby explaining the high activity of the coloaded Rh-Pd/Pb2 Ti2 O5.4 F1.2 catalyst toward H2 evolution.

8.
Angew Chem Int Ed Engl ; 61(26): e202204948, 2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35560974

RESUMEN

Photocatalytic conversion of CO2 into transportable fuels such as formic acid (HCOOH) under sunlight is an attractive solution to the shortage of energy and carbon resources as well as to the increase in Earth's atmospheric CO2 concentration. The use of abundant elements as the components of a photocatalytic CO2 reduction system is important, and a solid catalyst that is active, recyclable, nontoxic, and inexpensive is strongly demanded. Here, we show that a widespread soil mineral, alpha-iron(III) oxyhydroxide (α-FeOOH; goethite), loaded onto an Al2 O3 support, functions as a recyclable catalyst for a photocatalytic CO2 reduction system under visible light (λ>400 nm) in the presence of a RuII photosensitizer and an electron donor. This system gave HCOOH as the main product with 80-90 % selectivity and an apparent quantum yield of 4.3 % at 460 nm, as confirmed by isotope tracer experiments with 13 CO2 . The present work shows that the use of a proper support material is another method of catalyst activation toward the selective reduction of CO2 .

9.
ACS Appl Mater Interfaces ; 14(17): 19756-19765, 2022 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-35451831

RESUMEN

Wurtzite-structured Ga1-xZnx(N,O,F) was successfully synthesized by nitridation of mixtures of a Ga-containing oxide and ZnF2. The addition of ZnF2 lowered the nitridation temperature for the synthesis of Ga1-xZnx(N,O,F) to 823 K, even when bulk ZnGa2O4 was used as a paired precursor. This lowering of the synthesis temperature was ascribed to the enhancement of nitridation through the addition of fluorine. The low-temperature nitridation achieved by the addition of fluorine suppressed the volatilization of Zn compared with that during the synthesis of a GaN:ZnO solid solution by a conventional high-temperature ammonolysis reaction. The higher concentration of Zn, as well as the higher N concentration in Ga1-xZnx(N,O,F) achieved through the fluorine-assisted nitridation, led to a redshift of the absorption edge of Ga1-xZnx(N,O,F) to 560 nm compared with that of GaN:ZnO synthesized by the conventional ammonolysis reaction. The visible-light absorption of Ga1-xZnx(N,O,F) can be used to drive the photoelectrochemical oxidation of water.

10.
Chem Commun (Camb) ; 56(44): 5913-5916, 2020 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-32342082

RESUMEN

Rh ion-exchanged MFI-type aluminosilicate zeolites with different Al distributions were prepared for controlling the location, state, and size of Rh species. The MFI-type aluminosilicate zeolite with the framework Al atoms predominantly located inside the channel intersections leads to the formation of relatively large Rh species, which were confirmed by ultraviolet-visible (UV-vis) and infrared (IR) spectroscopies. Moreover, this catalyst showed a high catalytic activity for the oxidative reforming reaction of methane.

11.
Commun Chem ; 3(1): 129, 2020 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-36703370

RESUMEN

The development of simple catalysts with high performance in the selective oxidation of methane to syngas at low temperature has attracted much attention. Here we report a nickel-based solid catalyst for the oxidation of methane, synthesised by a facile impregnation method. Highly dispersed ultra-small NiO particles of 1.6 nm in size are successfully formed on the MOR-type zeolite. The zeolite-supported nickel catalyst gives continuously 97-98% methane conversion, 91-92% of CO yield with a H2/CO ratio of 2.0, and high durability without serious carbon deposition onto the catalyst at 973 K. DFT calculations demonstrate the effect of NiO particle size on the C-H dissociation process of CH4. A decrease in the NiO particle size enhances the production of oxygen originating from the NiO nanoparticles, which contributes to the oxidation of methane under a reductive environment, effectively producing syngas.

12.
Genes Cells ; 25(2): 139-148, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31887237

RESUMEN

HuH-7 cells, derived from human hepatocarcinoma, are known to contain the CD133-positive cancer stem cell populations. HuH-7 cells showed higher ATP synthesis activity through the respiratory chain compared to another human hepatocarcinoma cell line HepG2 and showed an especially higher glycerol-3-phosphate (G3P)-driven ATP synthesis (G3P-ATPase) activity. We found that the CD133-positive HuH-7 cells expressed high levels of GPD2 (glycerol-3-phosphate dehydrogenase or mGPDH) and showed high G3P-ATPase activity. Next, to elucidate the relationship between CD133 and GPD2, we inhibited downstream factors of CD133 and found that a p38 inhibitor decreased the expression of GPD2 and decreased the G3P-ATPase activity. Furthermore, GPD2-knockdown (GPD2-KD) cells exhibited strong reduction of the G3P-ATPase activity and reduction of lactic acid secretion. Finally, we validated the effect of GPD2-KD on tumorigenicity. GPD2-KD cells were found to show decreased anchorage-independent cell proliferation, suggesting the linkage of G3P-ATPase activity to the tumorigenicity of the CD133-positive HuH-7 cells. Inhibition of G3P-ATPase disrupts the homeostasis of energy metabolism and blocks cancer development and progression. Our results suggest inhibitors, targeting GPD2 may be potential new anticancer agents.


Asunto(s)
Transporte de Electrón/fisiología , Metabolismo Energético/fisiología , Glicerolfosfato Deshidrogenasa/metabolismo , Neoplasias Hepáticas/metabolismo , Mitocondrias/metabolismo , Membranas Mitocondriales/metabolismo , Antígeno AC133/genética , Antígeno AC133/metabolismo , Adenosina Trifosfato/metabolismo , Carcinoma Hepatocelular/metabolismo , Línea Celular , Transporte de Electrón/genética , Metabolismo Energético/genética , Técnicas de Silenciamiento del Gen , Técnicas de Transferencia de Gen , Glicerolfosfato Deshidrogenasa/genética , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Mitocondrias/genética , NAD/metabolismo , Transcriptoma
13.
IDCases ; 12: 1-3, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29942739

RESUMEN

INTRODUCTION: The route of methicillin-resistant Staphylococcus aureus (MRSA) transmission in the neonatal intensive care unit (NICU) is not clearly explained. We investigate an MRSA outbreak involving five babies in the NICU. The molecular investigation using polymerase chain reaction-based open reading frame typing (POT) method was performed. PRESENTATION OF OUTBREAK: A MRSA outbreak occurred in a six-bed NICU affecting 5 babies. Within 13 days of the emergence of index case, all five babies including triplets and other two babies were found to colonize MRSA by the active surveillance culture. Environmental surveillance cultures revealed that the preserved breast milk provided by the triplets' mother was the only item in the NICU that was positive for MRSA. The mother had a bite wound on the nipples, and the breast milk was not pasteurized. The POT method revealed that MRSA strains detected from the triplets, the breast milk, and the other baby who was fed the triplets' mother's milk were genetically identical (POT index: 106-247-33). The all strains of MRSA carried Staphylococcal cassette chromosome mec (SCCmec) IV and had good susceptibility for the non-ß-lactam antimicrobial agents, suggesting the strains were community-acquired MRSA. CONCLUSIONS: The mother's milk contaminated with community-origin MRSA is serving as the reservoir of MRSA and one of the sources of MRSA outbreaks in the NICU. It is important to closely monitor the condition of the mothers of the children in the NICU. Pasteurization of breast milk should be considered when the skin on the nipple is broken.

14.
Sci Rep ; 7: 46358, 2017 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-28406227

RESUMEN

X-ray spectromicroscopy with a full-field imaging technique is a powerful method for chemical analysis of heterogeneous complex materials with a nano-scale spatial resolution. For imaging optics, an X-ray reflective optical system has excellent capabilities with highly efficient, achromatic, and long-working-distance properties. An advanced Kirkpatrick-Baez geometry that combines four independent mirrors with elliptic and hyperbolic shapes in both horizontal and vertical directions was developed for this purpose, although the complexity of the system has a limited applicable range. Here, we present an optical system consisting of two monolithic imaging mirrors. Elliptic and hyperbolic shapes were formed on a single substrate to achieve both high resolution and sufficient stability. The mirrors were finished with a ~1-nm shape accuracy using elastic emission machining. The performance was tested at SPring-8 with a photon energy of approximately 10 keV. We could clearly resolve 50-nm features in a Siemens star without chromatic aberration and with high stability over 20 h. We applied this system to X-ray absorption fine structure spectromicroscopy and identified elements and chemical states in specimens of zinc and tungsten micron-size particles.


Asunto(s)
Microanálisis por Sonda Electrónica/instrumentación , Diseño de Equipo/métodos , Dispositivos Ópticos , Óptica y Fotónica
15.
Proc Natl Acad Sci U S A ; 108(31): 12675-80, 2011 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-21768338

RESUMEN

The mitogen-activated protein (MAP) kinase pathway is comprised of a three-tiered kinase cascade. The distributive kinetic mechanism of two-site MAP kinase phosphorylation inherently generates a nonlinear switch-like response. However, a linear graded response of MAP kinase has also been observed in mammalian cells, and its molecular mechanism remains unclear. To dissect these input-output behaviors, we quantitatively measured the kinetic parameters involved in the MEK (MAPK/ERK kinase)-ERK MAP kinase signaling module in HeLa cells. Using a numerical analysis based on experimentally determined parameters, we predicted in silico and validated in vivo that ERK is processively phosphorylated in HeLa cells. Finally, we identified molecular crowding as a critical factor that converts distributive phosphorylation into processive phosphorylation. We proposed the term quasi-processive phosphorylation to describe this mode of ERK phosphorylation that is operated under the physiological condition of molecular crowding. The generality of this phenomenon may provide a new paradigm for a diverse set of biochemical reactions including multiple posttranslational modifications.


Asunto(s)
Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Sistema de Señalización de MAP Quinasas , Modelos Biológicos , Algoritmos , Secuencia de Aminoácidos , Western Blotting , Núcleo Celular/metabolismo , Simulación por Computador , Citoplasma/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/genética , Transferencia Resonante de Energía de Fluorescencia , Células HEK293 , Células HeLa , Humanos , Cinética , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , MAP Quinasa Quinasa 1/genética , MAP Quinasa Quinasa 1/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Fosforilación , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Interferencia de ARN
16.
J Biol Chem ; 285(43): 33540-33548, 2010 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-20724475

RESUMEN

EGF-induced activation of ERK has been extensively studied by both experimental and theoretical approaches. Here, we used a simulation model based mostly on experimentally determined parameters to study the ERK-mediated negative feedback regulation of the Ras guanine nucleotide exchange factor, son of sevenless (SOS). Because SOS1 is phosphorylated at multiple serine residues upon stimulation, we evaluated the role of the multiplicity by building two simulation models, which we termed the decisive and cooperative phosphorylation models. The two models were constrained by the duration of Ras activation and basal phosphorylation level of SOS1. Possible solutions were found only in the decisive model wherein at least three, and probably more than four, phosphorylation sites decisively suppress the SOS activity. Thus, the combination of experimental approaches and the model analysis has suggested an unexpected role of multiple phosphorylations of SOS1 in the negative regulation.


Asunto(s)
Factor de Crecimiento Epidérmico/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Modelos Biológicos , Proteína SOS1/metabolismo , Proteínas ras/metabolismo , Factor de Crecimiento Epidérmico/genética , Quinasas MAP Reguladas por Señal Extracelular/genética , Células HeLa , Humanos , Fosforilación/fisiología , Proteína SOS1/genética , Proteínas ras/genética
17.
Opt Lett ; 33(3): 294-6, 2008 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-18246159

RESUMEN

Serially grafted polymer optical waveguides were fabricated by the light-induced self-written (LISW) waveguide technique for the first time to our knowledge. To realize functional waveguide cores by the LISW technique, transparent materials at the writing wavelength were selected. By inserting thin transparent partitions, a serial-graft structure consisting of passive and active waveguides without any misalignment was realized automatically. This technique is advantageous for its extremely easy process over conventional fabrication techniques.

18.
J Interferon Cytokine Res ; 24(6): 343-9, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15212708

RESUMEN

Recombinant human interleukin-11 (rHuIL-11) and recombinant human bone morphogenetic protein-2 (rHuBMP-2) have been shown to act synergistically in the induction of osteoblast differentiation. To determine whether these two proteins can be used clinically in fracture healing and reconstructive surgery, we investigated whether rHuIL-11 and rHuBMP-2 act synergistically to heal segmental bone defects in a rabbit model. A 1.5-cm segmental defect was created in the right ulnar diaphysis of 20 Japanese white rabbits. Polylactic-co-glycolic acid (PLGA)-coated gelatin sponges (PGS) permeated with rHuBMP-2 (n = 8), rHuIL-11 plus rHuBMP-2 (n = 8), or rHuIL-11 (n = 4) were implanted into the bone defects. Radiographs were scored by two independent observers for bone formation and union rates after 2, 3, 4, and 8 weeks. Bone formation was higher in rabbits implanted with rHuBMP-2 plus rHuIL-11 than in those implanted with rHuBMP-2 alone, reaching statistical significance after 4 weeks. At early time points, the union rate in rabbits implanted with rHuBMP-2 plus rHuIL-11 was higher than in rabbits implanted with rHuBMP-2. At 2, 4, and 8 weeks, new bone volume was significantly higher in rabbits administered rHuIL-11 plus rHuBMP-2 than in those given rHuBMP-2 alone. In contrast, mechanical testing after 8 weeks showed that bone strength in the two groups of rabbits was equivalent. These findings show that rHuIL-11 and rHuBMP-2 act synergistically to accelerate bone formation without affecting bone strength. Treatment with a combination of rHuIL-11 and rHuBMP-2 may thus be of great benefit in fracture healing and for patients undergoing reconstructive surgery.


Asunto(s)
Proteínas Morfogenéticas Óseas/farmacología , Regeneración Ósea/efectos de los fármacos , Sinergismo Farmacológico , Curación de Fractura , Interleucina-11/farmacología , Factor de Crecimiento Transformador beta/farmacología , Animales , Materiales Biocompatibles/metabolismo , Proteína Morfogenética Ósea 2 , Regeneración Ósea/fisiología , Portadores de Fármacos/metabolismo , Humanos , Ácido Láctico/metabolismo , Masculino , Ácido Poliglicólico/metabolismo , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros/metabolismo , Conejos , Radiografía , Proteínas Recombinantes , Cúbito/diagnóstico por imagen , Cúbito/patología
19.
J Interferon Cytokine Res ; 23(4): 203-7, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12856332

RESUMEN

We previously demonstrated that recombinant human interleukin-11 (rHuIL-11) induced osteoblast differentiation of C3H10T1/2 progenitor cells and also acted synergistically with recombinant human bone morphogenetic protein-2 (rHuBMP-2) in performing the same function. In this study, we investigated the effect of rHuIL-11 and rHuBMP-2 on bone formation in a rat ectopic model. When placed in rats, implants consisting of polymer-coated gelatin sponges containing various concentrations of rHuBMP-2 showed a dose-dependent increase in calcium content. This was confirmed by radiographic analysis of the implants. Although implants containing rHuIL-11 alone did not accumulate calcium, implants containing a combination of rHuBMP-2 and rHuIL-11 had significantly higher calcium levels than those containing rHuBMP-2 alone. This increase was rHuIL-11 dose dependent. The synergistic effect of 20 micrograms rHuIL-11 and 6 micrograms rHuBMP-2 on bone formation was estimated to be 1 week in advance of that of 6 micrograms rHuBMP-2 alone. Histologic examination revealed that the combination of rHuIL-11 and rHuBMP-2 caused spindle cells to accumulate around implants and induced cell infiltration into implants. Bone formation occurred faster in implants with the combination of rHuIL-11 and rHuBMP-2 compared with rHuBMP-2 alone. These results suggest that rHuIL-11 acts synergistically with rHuBMP-2 to more rapidly stimulate bone formation compared with rHuBMP-2 alone. This novel combined therapy may be of great clinical benefit in bone healing.


Asunto(s)
Desarrollo Óseo/efectos de los fármacos , Proteínas Morfogenéticas Óseas/farmacología , Interleucina-11/farmacología , Animales , Proteína Morfogenética Ósea 2 , Huesos , Calcio/metabolismo , Sinergismo Farmacológico , Humanos , Masculino , Osteogénesis/efectos de los fármacos , Prótesis e Implantes , Ratas , Ratas Long-Evans , Proteínas Recombinantes , Factor de Crecimiento Transformador beta/farmacología
20.
Arzneimittelforschung ; 52(11): 857-61, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12489258

RESUMEN

Interleukin-11 (IL-11, CAS 145941-26-0) is a cytokine that ameliorates thrombocytopenia induced by chemotherapy. Granulocyte colony-stimulating factor (G-CSF) is frequently used clinically as an adjuvant therapy to ameliorate neutropenia. In this study, it has been investigated whether IL-11 influences the hematopoietic action of G-CSF in vitro. IL-11 alone did not stimulate CFU-Meg colony formation in the absence of interleukin-3 (IL-3), but did in the presence of IL-3. However, IL-11 alone stimulated the formation of CFU-E, BFU-E and CFU-GM colonies, which were further enhanced by IL-3. G-CSF alone stimulated in a concentration dependent manner colony formation of CFU-GM and CFU-E, but not BFU-E or CFU-Meg. The addition of IL-11 enhanced the stimulatory effect of G-CSF on CFU-GM colony formation, and enabled G-CSF to stimulate colony formation of BFU-E, but not CFU-E. The addition of IL-3 further enhanced the stimulatory effect of G-CSF on CFU-E, BFU-E, and CFU-GM colony formation. However, G-CSF was unable to stimulate CFU-Meg colony formation for any of the cytokine combinations tested. These studies demonstrate that IL-11 has significant stimulatory effects on G-CSF-induced CFU-GM colony formation, suggesting that the therapeutic combination of the two growth factors could be beneficial for the treatment of myelosuppression induced by chemotherapy.


Asunto(s)
Factor Estimulante de Colonias de Granulocitos/farmacología , Hematínicos/farmacología , Interleucina-11/farmacología , Animales , Células de la Médula Ósea/efectos de los fármacos , Células Cultivadas , Sinergismo Farmacológico , Células Precursoras Eritroides/efectos de los fármacos , Femenino , Células Madre Hematopoyéticas/efectos de los fármacos , Interleucina-3/farmacología , Ratones , Ratones Endogámicos C57BL , Proteínas Recombinantes/farmacología , Trombopoyetina/efectos de los fármacos
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