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2.
J Pharm Sci ; 112(9): 2389-2392, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37453527

RESUMEN

LEDs development has attracted attention over conventional mercury lamps for the tiny size, high efficiency, long lifetime, low operating temperature. The antimicrobial effectiveness of traditional UV-lamps radiation (wavelength of 254 nm) compared to UV-C LEDs (LED1 wavelength range 275-286 nm and LED2 range 260-270 nm) was carried out, for possible applications to automated sterile drug compounding. The UV lamp and the tested UV-LED devices remarkably reduced microbial load, following a time-dose response, but the best performance was evidenced by LED1, which guaranteed the complete inactivation of high concentrations of bacteria, yeasts, and spores at doses between 200 and 2000 J/m2.


Asunto(s)
Desinfección , Rayos Ultravioleta , Viabilidad Microbiana , Composición de Medicamentos , Bacterias
3.
Eur J Hosp Pharm ; 27(e1): e63-e68, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32296508

RESUMEN

Objectives: To design and execute a comprehensive microbiological validation protocol to assess a brand-new sterile compounding robot in a hospital pharmacy environment, according to ISO and EU GMP standards. Methods: Qualification of the Class-A inner environment of the robot was performed through microbial air and surface quality assessment utilising contact plates, swabs and particulate matter monitoring. To evaluate the effectiveness of the microbial decontamination process (UV rays) challenge test against Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis spores and Candida albicans was used. The challenge Media Fill test was used to validate the aseptic processing. Results: After 3 hours, no microorganisms retained viability. Monitoring inside the equipment evidenced complete absence of microorganisms. The Media Fill test was always negative. Conclusions: According to our results, the APOTECAunit meets the requirements for advanced aseptic processing in the hospital pharmacies and the pharmaceutical industry in general, providing advantages in terms of safety for patients compared with conventional procedures of parenteral preparation production. The protocol has demonstrated to be a comprehensive and valuable tool in validating, from a microbial point of view, a sterile-compounding technology. This study might represent an important benchmark in developing a contamination control strategy, as required, for example, in the Performance Qualification of the GMP in the case of drug manufacturing.


Asunto(s)
Asepsia/normas , Descontaminación/normas , Composición de Medicamentos/normas , Contaminación de Medicamentos/prevención & control , Servicio de Farmacia en Hospital/normas , Robótica/normas , Asepsia/métodos , Descontaminación/métodos , Composición de Medicamentos/métodos , Humanos , Preparaciones Farmacéuticas/síntesis química , Preparaciones Farmacéuticas/normas , Servicio de Farmacia en Hospital/métodos , Reproducibilidad de los Resultados , Robótica/métodos
4.
J Occup Environ Hyg ; 16(1): 6-15, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30230976

RESUMEN

The automated aseptic preparation of ready-to-administer antineoplastic drug solutions with robotic systems reduces the risk of occupational exposure. However, the surfaces in the preparation area of the robot are to be cleaned by wiping with an appropriate cleaning solution. The aim of the study was to evaluate the cleaning efficacy of four cleaning solutions on four surface materials installed in the APOTECAchemo robot. Predefined amounts of cisplatin (Cis), 5-fluorouracil (5-FU), and cyclophosphamide (CP) were intentionally spread on test plates made of stainless steel, aluminium, polyoxymethylene, and polycarbonate just as installed in the robotic system APOTECAchemo. After drying, the plates were cleaned with 0.2% ethanolic NaOH, 0.23% isopropanolic sodium dodecylsulfate (SDS-2P), 0.5% sodium hypochlorite (NaOCl), and 0.1% benzalkonium chloride (BZK) solutions following a standardized wiping protocol. Residual contamination was recovered with wipe tests, Pt was quantified by voltammetry, and 5-FU and CP was quantified by gas chromatography-tandem mass spectrometry (GC-MSMS). The mean residual contamination after cleaning and the cleaning efficacy (CE) rates were calculated and aggregated on different levels. The CE rates varied between 81.5% and 100% and lay in the majority of cases above 90%. The lowest CE rates were registered for Pt contamination. Especially on aluminium surfaces the residual contamination was high. The overall CE rates of the three different drugs and four different surface types amounted to 98.3% for NaOCl, 97.9% for SDS-2P, 96.9% for ethanolic NaOH, and 96.5% for BZK. The tested cleaning solutions proved to be higher than 90% in most cases, but none of them was able to eliminate 100% of the intentional surface contamination of three antineoplastic drugs on the test plates. The cleaning efficacy varied according to the different surface types and antineoplastic drug. Results could be used in the daily clinical practice to develop and implement effective cleaning procedures.


Asunto(s)
Antineoplásicos , Descontaminación/métodos , Detergentes , Cisplatino , Ciclofosfamida , Composición de Medicamentos/instrumentación , Fluorouracilo , Servicio de Farmacia en Hospital/métodos , Robótica/instrumentación
5.
Artículo en Inglés | MEDLINE | ID: mdl-28451441

RESUMEN

BACKGROUND: The accuracy, safety and feasibility of, the compounding robot APOTECAchemo were evaluated in the clinical practice of Japan. METHODS: Accuracy and precision of robotic preparations by APOTECAchemo was evaluated in 20 preparations of fluorouracil (FU) and cyclophosphamide (CPA) infusions by four pharmacists. Environmental and product contaminations with FU and CPA were evaluated by wipe testing. Robotic performance was compared with manual preparation in a biological safety cabinet. The number of robotic products, total compounding time and total pre-reconstitution time of lyophilized drugs between January 1, 2014 to December 31, 2015 were investigated. RESULTS: Robotic preparation resulted more accurate and precise (mean absolute dose error and coefficient of variation were 0.83 and 1.04% for FU and 0.52 and 0.59% for CPA) than those of manual preparation (respective values were 1.20 and 1.46% for FU and 1.70 and 2.20% for CPA). Drug residue was not detected from any of the prepared infusion bags with the robotic preparation, whereas FU was detected in two of four analyzed infusion bags with manual preparation. Average total time to make single anticancer drug preparation (compounding plus reconstitution of lyophilized drugs) was 6.11 min in the second half of 2015. During the study period, the highest percentage of production covered by APOTECAchemo was 70.4% of the total inpatient pharmacy activity. CONCLUSION: Robotic preparation using APOTECAchemo should give substantial advantages in drug compounding for accuracy and safety and was able to be successfully worked in Mie university hospital.

6.
Am J Health Syst Pharm ; 74(1): e40-e46, 2017 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-28007720

RESUMEN

PURPOSE: The development of recommendations for advancing automated i.v. medication compounding is described. SUMMARY: Managing the shift from manual to robotic compounding of i.v. therapies requires an awareness of how automation affects practice and how to best implement robotics into current practice. An international panel of pharmacy professionals, researchers, and technology leaders with experience in i.v. robotics collaborated during a two-day meeting in August 2014 to define a general set of principles to broaden the understanding of the fundamental elements of robotic compounding worldwide. Participants were divided into four working groups (technology and safety; drugs and products; personnel; and facilities and quality) to analyze specific aspects of robotic compounding practice. The four working groups produced an initial list of 92 statements. This list was condensed to 35 statements by consolidating similar and overlapping statements from the different work groups. Participants were surveyed again to assess agreement with the 35 statements and solicit additional clarification. Respondents expressed full agreement with 25 recommendations. Six statements received one or more "don't know" responses, with all other respondents in agreement. Four statements had a combination of "don't know" and "disagree" responses. A total of 32 comments were recorded in free-text fields, including requests for clarification and suggestions for rewording the statements. CONCLUSION: An international panel of pharmacy professionals, researchers, and technology leaders with experience in i.v. robotics developed a set of 35 recommendations toward a better understanding of the role of automated i.v. compounding in hospital and health-system pharmacies worldwide.


Asunto(s)
Automatización/normas , Composición de Medicamentos/normas , Servicio de Farmacia en Hospital/normas , Robótica , Administración Intravenosa , Automatización/instrumentación , Automatización/métodos , Composición de Medicamentos/instrumentación , Composición de Medicamentos/métodos , Humanos , Servicio de Farmacia en Hospital/métodos , Guías de Práctica Clínica como Asunto , Encuestas y Cuestionarios
7.
J Oncol Pharm Pract ; 22(1): 37-45, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25227229

RESUMEN

OBJECTIVES: The aim of this study was to compare environmental contamination of cyclophosphamide (CP) during 1 week of drug compounding by conventional manual procedure in a biological safety cabinet (BSC) with laminar airflow and a new robotic drug preparation system (APOTECAchemo). METHODS: During four consecutive days, similar numbers of infusion bags with cyclophosphamide were prepared with both techniques in a cross-over design. Wipe samples (49 for BSC, 50 for APOTECAchemo) were taken at several locations (gloves, infusion bags, trays, BSC-benches, floor) in the pharmacy and analyzed for CP concentrations by GC-MSMS (LOD 0.2 ng/sample). RESULTS: The detection rate was 70% in the BSC versus 15% in APOTECAchemo. During manual preparation of admixtures using BSC contamination with CP was below 0.001 ng/cm(2) at most locations, but significant on gloves (0.0004-0.0967 ng/cm(2)) and the majority (70%) of infusion bags (<0.0004-2.89 ng/cm(2)). During robotic preparation by APOTECAchemo, gloves (1 of 8: 0.0007 ng/cm(2)) and infusion bags (3 of 20: 0.0005, 0.0019, 0.0094 ng/cm(2)) were considerably less contaminated. Residual contamination was found on the surfaces under the dosing device in the compounding area (0.0293-0.1603 ng/cm(2)) inside the robotic system. CONCLUSIONS: Compared to outcomes of other studies, our results underline good manufacturing procedures in this pharmacy with low contamination for both techniques (BSC and APOTECAchemo). Comparison of both preparation procedures validated that contamination of infusion bags was much lower by using the robotic system.


Asunto(s)
Antineoplásicos/química , Ciclofosfamida/química , Contaminación de Equipos/prevención & control , Contaminación de Medicamentos/prevención & control , Monitoreo del Ambiente/métodos , Exposición Profesional/prevención & control , Farmacias , Servicio de Farmacia en Hospital/métodos , Equipos de Seguridad , Robótica/métodos
8.
Int J Qual Health Care ; 27(5): 412-7, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26233490

RESUMEN

OBJECTIVE: Ultraviolet (UV) irradiation efficacy in the intravenous compounding robot APOTECAchemo was evaluated to define the best operative conditions in terms of sterility and time optimization. DESIGN: The challenge test was used against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis spores and Candida albicans. Inoculated plates were placed inside the robot and irradiated for different times. Microbial air and surface quality inside the equipment were monitored utilizing settle and contact plates, swabs. RESULTS: After 4 h, no microorganisms were viable with killing rates ranging from 5- to 7-log for different microorganisms after 1 h of exposition. In confirmation of the efficacy of the UV irradiation program adopted, the microbial monitoring inside the equipment always gave negative results. CONCLUSIONS: This is the first exhaustive investigation of UV irradiation efficacy in the aseptic pharmaceutical production. We demonstrated that UV irradiation plays an essential role in maintaining the sterility condition of the workplace inside the APOTECAchemo and assuring the standards for aseptic manufacturing of medicinal drugs, as required for Class A clean areas. A 4-h UV irradiation also ensures sterility in the case of very resistant microorganisms and in the presence of high microbial charge (10(8) CFU/ml), but a killing rate of 5 or more is already recorded after the first hour of exposition. The results provide useful information for the best operative conditions in terms of both sterility and time optimization, not only for the automated compounding, but also for the traditional aseptic manufacturing processes.


Asunto(s)
Composición de Medicamentos/métodos , Servicio de Farmacia en Hospital/métodos , Esterilización/métodos , Rayos Ultravioleta , Bacterias/aislamiento & purificación , Hongos/aislamiento & purificación , Humanos , Inyecciones Intravenosas , Robótica
9.
Am J Health Syst Pharm ; 71(7): 579-85, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24644118

RESUMEN

PURPOSE: The quality and economic implications of manual versus automated preparation of antineoplastic drugs were compared. METHODS: This four-week study evaluated 10 routinely used antineoplastic drugs (fluorouracil, cyclophosphamide, gemcitabine, trastuzumab, bevacizumab, oxaliplatin, cisplatin, paclitaxel, irinotecan, and etoposide) prepared by manual and automated procedures. The accuracy of the dose of the active ingredient was calculated in terms of percent relative error for the difference between the nominal value indicated on the prescription and the actual value of the drug in the finished product. A comparative economic analysis of the manual and automated preparation procedures was performed by calculating the mean unit cost for each preparation at different production levels. Participating pharmacists and technicians completed a survey rating each preparation method in terms of performance, operator satisfaction, technology, and safety. RESULTS: Of the 2500 i.v. antineoplastic preparations made in the pharmacy during the four-week study period, 681 were analyzed (348 using the automated procedure and 333 manually). Of these, 17 varied by more than 5% of the prescribed dose, and 1 varied by over 10%. Accuracy, calculated in terms of average percent relative error, was the highest and lowest during manual preparation. The preparation time for individual drugs was always higher when prepared using the automated procedure. A lower mean variable unit cost was observed for preparations made using the automated procedure. Questionnaire results revealed that operators preferred the automated procedure over the manual procedure. CONCLUSION: Both the automated and manual procedures for preparing antineoplastic preparations proved to be accurate and precise. The automated procedure resulted in substantial advantages in terms of quality maintenance standards and risk lowering.


Asunto(s)
Antineoplásicos/economía , Antineoplásicos/normas , Mejoramiento de la Calidad , Automatización , Costos de los Medicamentos , Humanos , Estudios Prospectivos
10.
Chem Commun (Camb) ; (40): 4867-74, 2008 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-18931725

RESUMEN

Since their very first days, electron transfer has always played a special role in carbon nanotubes' life. In view of their structural and electronic uniqueness, carbon nanotubes have been proposed either as bulk electrode materials for sensing and biosensing in advanced electrochemical devices, or as molecular-sized electrodes for very fast electrode kinetics investigations. Alternatively, electron transfer has been used to probe the electronic properties of carbon nanotubes by either direct voltammetric inspection or coupling with spectroscopic techniques, ultimately allowing, in the case of true solutions of individual uncut single-walled carbon nanotubes (SWNTs), to single-out their redox potentials as a function of diameter. For their redox properties, as emerged from these studies, SWNTs represent unique building blocks for the construction of photofunctional nanosystems to be used in efficient light energy conversion devices.

11.
J Am Chem Soc ; 130(23): 7393-9, 2008 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-18479091

RESUMEN

Bandgap fluorescence spectroscopy of aqueous, micelle-like suspensions of SWNTs has given access to the electronic energies of individual semiconducting SWNTs, while substantially lower is the success achieved in the determination of the redox properties of SWNTs as individual entities. Here we report an extensive voltammetric and vis-NIR spectroelectrochemical investigation of true solutions of unfunctionalized SWNTs and determine the standard electrochemical potentials of reduction and oxidation as a function of the tube diameter of a large number of semiconducting SWNTs. We also establish the Fermi energy and the exciton binding energy for individual tubes in solution. The linear correlation found between the potentials and the optical transition energies is quantified in two simple equations that allow one to calculate the redox potentials of SWNTs that are insufficiently abundant or absent in the samples.


Asunto(s)
Nanotubos de Carbono/química , Electroquímica/métodos , Oxidación-Reducción , Soluciones , Espectroscopía Infrarroja Corta , Termodinámica
12.
J Am Chem Soc ; 130(12): 3788-96, 2008 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-18314972

RESUMEN

The formidable electron-acceptor properties of C60 contrast with its difficult oxidations. Only recently it has become possible to achieve reversibility of more than one electrochemical anodic process versus the six reversible cathodic reductions. Here we exploit the reactivity of electrochemical oxidations of pure C60 to grow a film of high thermal and mechanical stability on the anode. The new material differs remarkably from its precursor since it conducts both electrons and holes. Its growth and properties are consistently characterized by a host of techniques that include atomic force microscopy (AFM), Raman and infrared spectroscopies, X-ray-photoelectron spectroscopy (XPS), secondary-ion mass spectrometry (SIMS), scanning electron microscopy and energy-dispersive X-ray analysis (SEM-EDX), matrix-assisted laser desorption/ionization (MALDI), and a variety of electrochemical measurements.


Asunto(s)
Fulerenos/química , Membranas Artificiales , Cationes/química , Electroquímica , Electrodos , Microscopía Electrónica de Rastreo , Oxidación-Reducción , Tamaño de la Partícula , Platino (Metal)/química , Espectrometría de Masa de Ion Secundario , Análisis Espectral , Propiedades de Superficie , Rayos X
13.
J Am Chem Soc ; 129(13): 3938-45, 2007 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-17343379

RESUMEN

Single-wall carbon nanohorns (SWNHs) are a new class of material that is closely related to single-wall carbon nanotubes. Here, we describe the synthesis and characterization of a series of SWNHs functionalized with ethylene glycol chains and porphyrins. Functionalization of carbon nanohorns has been achieved using two different synthetic protocols: (1) direct attack of a free amino group on the nanohorn sidewalls (nucleophilic addition) and (2) amidation reaction of the carboxylic functions in oxidized nanohorns. The nanohorn derivatives have been characterized by a combination of several techniques, and the electronic properties of the porphyrin/nanohorn assemblies (SWNH/H2P) have been investigated by electrochemistry, spectroelectrochemistry, and a series of steady-state and time-resolved spectroscopy. The cyclic voltammetry curve of nanohorn/porphyrin conjugate 6 showed a continuum of faradic and pseudocapacitive behavior, which is associated with multiple-electron transfers to and from the SWNHs. Superimposed on such a pseudocapacitive current, the curve also displays three discrete reduction peaks at -2.26, -2.57, and -2.84 V and an oxidation peak at 1.12 V (all attributed to the porphyrin moiety). Steady-state and time-resolved fluorescence demonstrated a quenching of the fluorescence of the porphyrin in SWNH/H2P conjugates 5 and 6 compared to the reference free base porphyrin. Transient absorption spectra permitted the electron-transfer process between the porphyrins and the carbon nanostructures to be highlighted.


Asunto(s)
Carbono/química , Electrones , Nanoestructuras/química , Electroquímica , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , Nanoestructuras/ultraestructura , Nanotubos de Carbono/química , Fotoquímica , Espectrometría Raman
14.
Chemistry ; 13(18): 5249-55, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17393372

RESUMEN

18-Crown[6] ether has been used to prepare a new class of organic-inorganic complexes of general formula 18-crown[6]M[HSO(4)](n) (where M = NH(4) (+), K(+), Sr(2+) and n = 1, 2) by reacting directly in solution or in the solid state the crown ether 18-crown[6] with inorganic salts such as [NH(4)][HSO(4)], K[HSO(4)], and Sr[HSO(4)](2). The structures of 18-crown[6][NH(4)][HSO(4)]2 H(2)O (12 H(2)O), 18-crown[6][NH(4)][HSO(4)] (1), 18-crown[6]K[HSO(4)]2 H(2)O (22 H(2)O), 18-crown[6]K[HSO(4)] (2), and 18-crown[6]Sr[HSO(4)](2) (3) have been characterized by single-crystal X-ray diffraction. The reversible water loss in compounds 12 H(2)O and 22 H(2)O leads to formation of the corresponding anhydrous phases 18-crown[6][NH(4)][HSO(4)] (1), and 18-crown[6]K[HSO(4)] (2), which undergo, on further heating, enantiotropic solid-solid transitions very likely associated with the on-set of a solid state dynamical process. Similar high-temperature behavior is shown by 18-crown[6]Sr[HSO(4)](2) (3). The dehydration and phase-transition processes have been investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and variable temperature X-ray powder diffraction.

15.
J Am Chem Soc ; 128(34): 11222-31, 2006 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-16925441

RESUMEN

This work provides an in-depth look at a range of physicochemical aspects of (i) single wall carbon nanotubes (SWNT), (ii) pyrene derivatives (pyrene(+)), (iii) porphyrin derivatives (ZnP(8)()(-)() and H(2)()P(8)()(-)()), (iv) poly(sodium 4-styrenesulfonate), and (v) their combinations. Implicit in their supramolecular combinations is the hierarchical integration of SWNT (as electron acceptors), together with ZnP(8)()(-)() or H(2)()P(8)()(-)() (as electron donors), in an aqueous environment mediated through pyrene(+). This supramolecular approach yields novel electron donor-acceptor nanohybrids (SWNT/pyrene(+)/ZnP(8)()(-)() or SWNT/pyrene(+)/H(2)()P(8)()(-)()). In particular, we report on electrochemical and photophysical investigations that as a whole suggest sizeable and appreciable interactions between the individual components. The key step to form SWNT/pyrene(+)()/ZnP(8)()(-)() or SWNT/pyrene(+)()/H(2)()P(8)()(-)() hybrids is pi-pi interactions between SWNT and pyrene(+), for which we have developed for the first time a sensitive marker. The marker is the monomeric pyrene fluorescence, which although quenched is (i) only present in SWNT/pyrene(+) and (ii) completely lacking in just pyrene(+). Electrostatic interactions help to immobilize ZnP(8)()(-)() or H(2)()P(8)()(-)() onto SWNT/pyrene(+) to yield the final electron donor-acceptor nanohybrids. A series of photochemical experiments confirm that long-lived radical ion pairs are formed as a product of a rapid excited-state deactivation of ZnP(8)()(-)() or H(2)()P(8)()(-)(). This formation is fully rationalized on the basis of the properties of the individual moieties. Additional modeling shows that the data are likely to be relevant to the SWNTs present in the sample, which possess wider diameters.


Asunto(s)
Nanotubos de Carbono , Porfirinas/química , Pirenos/química , Microscopía Electrónica de Transmisión , Espectrometría de Fluorescencia
16.
Chemistry ; 12(15): 3975-83, 2006 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-16586415

RESUMEN

Noncovalent interactions between purified HiPCO single-wall carbon nanotubes (SWNT) and a [60]fullerene-pyrene dyad, synthesized through a regioselective double-cyclopropanation process, produce stable suspensions in which the tubes are very well dispersed, as evidenced by microscopy characterization. Cyclic voltammetry experiments and photophysical characterization of the suspensions in organic solvents are all indicative of sizeable interactions of the pyrene moiety with the SWNT and, therefore, of the prevalence in solution of [60]fullerene-pyreneSWNT hybrids.


Asunto(s)
Fulerenos/química , Sustancias Macromoleculares/química , Nanotubos de Carbono/química , Electroquímica , Pirenos/química
17.
Chemistry ; 12(8): 2152-61, 2006 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-16370006

RESUMEN

Dispersible single-walled carbon nanotubes grafted with poly(4-vinylpyridine), SWNT-PVP, were tested in coordination assays with zinc tetraphenylporphyrin (ZnP). Kinetic and spectroscopic evidence corroborates the successful formation of a SWNT-PVPZnP nanohybrid. Within this SWNT-PVPZnP nanohybrid, static electron-transfer quenching (2.0+/-0.1) x 10(9) s(-1) converts the photoexcited-ZnP chromophore into a radical-ion-pair state with a microsecond lifetime, namely one-electron oxidized-ZnP and reduced-SWNT.

18.
Cell ; 122(2): 221-33, 2005 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-16051147

RESUMEN

Reactive oxygen species (ROS) are potent inducers of oxidative damage and have been implicated in the regulation of specific cellular functions, including apoptosis. Mitochondrial ROS increase markedly after proapoptotic signals, though the biological significance and the underlying molecular mechanisms remain undetermined. P66Shc is a genetic determinant of life span in mammals, which regulates ROS metabolism and apoptosis. We report here that p66Shc is a redox enzyme that generates mitochondrial ROS (hydrogen peroxide) as signaling molecules for apoptosis. For this function, p66Shc utilizes reducing equivalents of the mitochondrial electron transfer chain through the oxidation of cytochrome c. Redox-defective mutants of p66Shc are unable to induce mitochondrial ROS generation and swelling in vitro or to mediate mitochondrial apoptosis in vivo. These data demonstrate the existence of alternative redox reactions of the mitochondrial electron transfer chain, which evolved to generate proapoptotic ROS in response to specific stress signals.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Apoptosis/fisiología , Citocromos c/metabolismo , Mitocondrias Hepáticas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Secuencia de Aminoácidos , Animales , Células Cultivadas , Transporte de Electrón , Peróxido de Hidrógeno/metabolismo , Membranas Intracelulares/metabolismo , Ratones , Datos de Secuencia Molecular , Mutación , Oxidación-Reducción , Permeabilidad , Estructura Terciaria de Proteína , Proteínas Adaptadoras de la Señalización Shc , Transducción de Señal , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src
19.
J Phys Chem A ; 109(43): 9723-30, 2005 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-16833285

RESUMEN

Fine-tuned control over the donor strength in a series of trannulenes-based donor-acceptor ensembles is used to alter the deactivation path of the photoexcited-state chromophore and to modulate the rates of intramolecular electron transfer. For the first time, a detailed analysis of emission spectra, time-dependent spectroscopic measurements, and electrochemistry prove spectroscopically and kinetically that trannulenes can serve, in a manner similar to C(60) and C(60) monoadducts, as both electron and also as energy acceptor in donor-acceptor ensembles, producing widely different electron-transfer regimes. This investigation also shows that the integration of trannulenes, as a versatile electron-acceptor building block, consistently produces charge recombination in the inverted Marcus region.

20.
Chem Commun (Camb) ; (18): 2034-5, 2004 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-15367961

RESUMEN

Donor-acceptor nanoensembles, prepared via electrostatic interactions of single wall carbon nanotubes and porphyrin salts, give rise to photoinduced intra-complex charge separation that lasts tens of microseconds.

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