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1.
Small ; 19(34): e2300104, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37186509

RESUMEN

Gossypol is a chemotherapeutic drug that can inhibit the anti-apoptotic protein Bcl-2, but the existing gossypol-related nanocarriers cannot well solve the problem of chemotherapy resistance. Based on the observation that gossypol becomes black upon Fe3+ coordination, it is hypothesized that encasing gossypol in glyceryl monooleate (GMO) and making it coordinate cobalt ferrite will not only improve its photothermal conversion efficiency (PCE) but also help it enter tumor cells. As the drug loading content and drug encapsulation efficiency of gossypol are 10.67% (w/w) and 96.20%, the PCE of cobalt ferrite rises from 14.71% to 36.00%. The synergistic therapeutic effect finally induces tumor apoptosis with a tumor inhibition rate of 96.56%, which is 2.99 and 1.47 times higher than chemotherapy or photothermal therapy (PTT) alone. PTT generated by the GMO nanocarriers under the irradiation of 808 nm laser can weaken tumor hypoxia, thereby assisting gossypol to inhibit Bcl-2. In addition, the efficacy of nanocarriers is also evaluated through T2 -weighted magnetic resonance imaging. Observations of gossypol-induced apoptosis in tissue slices provide definitive proof of chemotherapy sensitization, indicating that such coordination nanocarriers can be used as an effective preclinical agent to enhance chemotherapy.


Asunto(s)
Cobalto , Gosipol , Neoplasias , Humanos , Apoptosis , Línea Celular Tumoral , Cobalto/farmacología , Cobalto/uso terapéutico , Gosipol/farmacología , Gosipol/uso terapéutico , Neoplasias/tratamiento farmacológico
2.
Spine Deform ; 11(4): 815-823, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36920741

RESUMEN

PURPOSE: To evaluate the effectiveness of vancomycin prophylaxis on spinal implant metal types. METHODS: 42 rabbits underwent posterior, single-level instrumentation at L5-L6 with stainless steel (n = 18), cobalt chrome (n = 12), or titanium (n = 12) wire. All implants were inoculated with 1 × 106 colony forming units (CFU) of methicillin-resistant S. Aureus (MRSA). In the intrawound vancomycin subgroup (n = 18, 6 from each metal type), 40 mg of vancomycin powder was placed in the wound. In the IV vancomycin subgroup (n = 6, all stainless steel), 15 mg/kg of IV vancomycin was given preoperatively. Local soft tissue and implants were harvested 1-week postoperatively and separately cultured. RESULTS: Intrawound vancomycin significantly reduced the rate of soft tissue infection (44.4% vs 100%) and implant infection (27.8% vs 100%) (p < 0.001). Within the intrawound vancomycin subgroup, cobalt chrome implants were associated with higher median soft tissue MRSA growth (130 CFU) than stainless steel (0 CFU) or titanium (0 CFU) (p = 0.02). Cobalt chrome implants were also more likely to develop soft tissue MRSA infection (83.3%) as compared to stainless steel (16.7%) or titanium (33.3%) (p = 0.04). Median soft tissue MRSA growth among stainless steel implants without prophylaxis, with IV vancomycin, and with vancomycin powder was 1.18 × 107, 195, and 0 CFU, respectively. The rate of soft tissue MRSA infection without prophylaxis, with IV vancomycin, and with vancomycin powder was 100, 66.7, and 16.7%, respectively (p = 0.015). CONCLUSION: Intrawound vancomycin is more effective than IV vancomycin and effectively reduces the risk of infection, but is less effective in cobalt chrome implants due to residual soft tissue infection.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Infecciones Relacionadas con Prótesis , Infecciones de los Tejidos Blandos , Enfermedades de la Columna Vertebral , Animales , Conejos , Vancomicina/uso terapéutico , Antibacterianos/uso terapéutico , Titanio , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Polvos/uso terapéutico , Acero Inoxidable , Cobalto/uso terapéutico
3.
J Neurol ; 269(11): 5798-5811, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35900586

RESUMEN

Parkinson's disease (PD) is an ageing disorder with deterioration of dopamine neurons which leads to motor complications like tremor, stiffness, slow movement and postural disturbances. In PD, both genetics as well as environmental factors both play a major role in causing the pathogenesis. Though there are surfeit of risk factors involved in PD occurrence, till now there is lack of an exact causative agent as a risk for PD with confirmative findings. The role of heavy metals reported to be a significant factor in PD pathogenesis. Heavy metal functions in cell maintenance but growing pieces of evidences reported to cause dyshomeostasis with increased PD rate. Metals disturb the molecular processes and results in oxidative stress, DNA damage, mitochondrial dysfunction, and apoptosis. The present review elucidates the role of cobalt, nickel, mercury, chromium, thallium metals in α-synuclein aggregation and its involvement in blood brain barrier flux. Also, the review explains the plausible role of aforementioned metals with a mechanistic approach and therapeutic recommendations in PD.


Asunto(s)
Mercurio , Metales Pesados , Enfermedad de Parkinson , Cromo/uso terapéutico , Cobalto/uso terapéutico , Humanos , Mercurio/uso terapéutico , Metales Pesados/toxicidad , Níquel/uso terapéutico , Enfermedad de Parkinson/tratamiento farmacológico , Talio/uso terapéutico , alfa-Sinucleína
4.
J Alzheimers Dis ; 87(4): 1503-1516, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35527546

RESUMEN

BACKGROUND: Acetylcholinesterase (AChE) regulates the transmission of neural messages by hydrolyzing acetylcholine in synaptic spaces. OBJECTIVE: The effects of many AChE inhibitors have been evaluated in the treatment of Alzheimer's disease, but the present study examined a synthetic complex containing cobalt (SC) for the first time in the field of enzyme activity to evaluate enzyme inhibitory function. METHODS: Ellman's test was applied. AChE function was assessed in the presence of SC through docking and molecular dynamics analyses. The second structure of AChE was studied through circular dichroism (CD) spectroscopy. RESULTS: Several enzymatic methods were utilized for the kinetics of AChE, which indicated the non-Michaelis and positive homotropic behavior of AChE in the absence of inhibitors (Hill coefficient = 1.33). However, the existence of inhibitors did not eliminate this homotropic state, and even AChE had a more sigmoidal shape than the galantamine at the presence of SC. Based on the CD spectroscopy results, AChE structure changed in the existence of inhibitors and substrates. Bioinformatics analysis revealed SC bonding to the channel of active site AChE. The number of hydrogen bonds was such that the flexibility of the enzyme protein structure due to inhibitor binding reduced AChE function. CONCLUSION: The results reflected that AChE exhibited a non-Michaelis and positive homotropic behavior, leading to a more inhibitory effect on the SC than the galantamine. The positive homotropic behavior of AChE was intensified due to the alteration in AChE protein structure by binding SC to hydrophobic region in the active site pathway and impressing Trp84.


Asunto(s)
Enfermedad de Alzheimer , Galantamina , Acetilcolinesterasa/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Inhibidores de la Colinesterasa/uso terapéutico , Cobalto/farmacología , Cobalto/uso terapéutico , Galantamina/farmacología , Galantamina/uso terapéutico , Humanos , Simulación del Acoplamiento Molecular
5.
ACS Appl Mater Interfaces ; 13(10): 11683-11695, 2021 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-33656325

RESUMEN

Glucose oxidase (GOx) is regarded as an ideal endogenous natural enzyme for tumor starvation therapy and photothermal therapy (PTT) is a promising strategy for the ablation of primary tumor. In this work, Cu-doped cobalt oxide and porous carbon nanocomposites (CuCo(O)@PCNs) were synthesized from double-layered ZIF-8@ZIF-67 and GOx was loaded in the porous carbon to form a CuCo(O)/GOx@PCNs hybrid nanozyme. CuCo(O) was characterized as the Cu0.3Co2.7O4 phase through X-ray diffraction analysis and it can react with H2O2 to generate O2 and alleviate tumor hypoxia, resulting in the recovered enzymatic activity of GOx and the enhanced starvation therapy. The porous nanocarbon can ablate the primary tumor because of its high photothermal conversion efficiency of 40.04%. The three-in-one functions of oxygen supply, glucose consumption, and photothermal conversion were realized in the ZIFs-derived CuCo(O)/GOx@PCNs nanozyme and the starvation therapy effect was improved by PTT and oxygen supplement. Furthermore, the inhibition effect of CuCo(O)/GOx@PCNs on metastatic tumor is similar to combined therapy of the nanozyme and the immune checkpoint-blocking antibody, α-PD-1. The related antitumor immune mechanism was studied through the analysis of immune-related proinflammatory cytokines and the activated T cells. This work may provide new ideas for the development and application of the ZIFs-derived hybrid nanozyme in tumor therapy and the CuCo(O)/GOx@PCNs nanozyme may be a promising alternative to immune checkpoint inhibitors.


Asunto(s)
Carbono/uso terapéutico , Cobalto/uso terapéutico , Cobre/uso terapéutico , Glucosa Oxidasa/uso terapéutico , Imidazoles/uso terapéutico , Estructuras Metalorgánicas/uso terapéutico , Neoplasias/terapia , Óxidos/uso terapéutico , Animales , Línea Celular Tumoral , Humanos , Inmunoterapia , Ratones , Terapia Fototérmica , Hipoxia Tumoral
6.
Adv Mater ; 32(45): e2003712, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33002227

RESUMEN

Nanoparticle-based magnetic hyperthermia is a well-known thermal therapy platform studied to treat solid tumors, but its use for monotherapy is limited due to incomplete tumor eradication at hyperthermia temperature (45 °C). It is often combined with chemotherapy for obtaining a more effective therapeutic outcome. Cubic-shaped cobalt ferrite nanoparticles (Co-Fe NCs) serve as magnetic hyperthermia agents and as a cytotoxic agent due to the known cobalt ion toxicity, allowing the achievement of both heat and cytotoxic effects from a single platform. In addition to this advantage, Co-Fe NCs have the unique ability to form growing chains under an alternating magnetic field (AMF). This unique chain formation, along with the mild hyperthermia and intrinsic cobalt toxicity, leads to complete tumor regression and improved overall survival in an in vivo murine xenograft model, all under clinically approved AMF conditions. Numerical calculations identify magnetic anisotropy as the main Co-Fe NCs' feature to generate such chain formations. This novel combination therapy can improve the effects of magnetic hyperthermia, inaugurating investigation of mechanical behaviors of nanoparticles under AMF, as a new avenue for cancer therapy.


Asunto(s)
Cobalto/química , Cobalto/uso terapéutico , Compuestos Férricos/química , Compuestos Férricos/uso terapéutico , Nanopartículas/química , Animales , Línea Celular Tumoral , Cobalto/efectos adversos , Compuestos Férricos/efectos adversos , Humanos , Hipertermia Inducida , Campos Magnéticos , Ratones , Análisis de Supervivencia , Ensayos Antitumor por Modelo de Xenoinjerto
7.
Nanotechnology ; 31(30): 305706, 2020 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-32235044

RESUMEN

Novel supported inorganic metal nano-complexes of Ag(I) and Co(II) derived from 4-amino-N-(4-methylpyrimidin-2-yl) benzene sulfonamide (SulMer) were synthesized using olive leaf extract as a reducing agent with grinding and microwave methods. The prepared samples were denoted as Comp1-6. The surface morphologies of the synthesized nanomaterials were analyzed using C, H, N, S analysis, Fourier-transform infrared spectroscopy, UV- visible spectroscopy, proton and carbon nuclear magnetic resonance, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and x-ray powder diffraction (XRD) analysis. The data revealed that all the synthesized complexes exhibited a 1:1 metal-to-ligand ratio with a coordination number of 4 or 6. The mean particle size of the nanomaterial samples was 25-35 nm. The XRD patterns indicated a crystalline nature for the complexes. The supported inorganic metal nano-complexes displayed good activity in the adsorptive removal of Direct Red 81 (DR-81) from aqueous solutions. In addition, the effect of the supported metal nano-complexes on the immune system was studied as well as how these anti-inflammatory compounds could be used to treat many autoimmune diseases, most notably rheumatoid arthritis. An experimental model for arthritis can be induced using complete Freund's adjuvant. It was shown that the supported complex offers several advantages such stability, eco-friendliness, simple experimental conditions, short reaction times, and easy work- up.


Asunto(s)
Antiinflamatorios/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Cobalto/administración & dosificación , Adyuvante de Freund/efectos adversos , Plata/administración & dosificación , Adsorción , Animales , Antiinflamatorios/química , Antiinflamatorios/uso terapéutico , Artritis Reumatoide/inducido químicamente , Compuestos Azo/química , Cobalto/química , Cobalto/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Nanopartículas del Metal/química , Nanotubos de Carbono/química , Olea/química , Tamaño de la Partícula , Hojas de la Planta/química , Ratas , Plata/química , Plata/uso terapéutico
8.
Brain Res ; 1732: 146684, 2020 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-32001242

RESUMEN

BACKGROUND: Calcium signaling is described as a relevant factor in synchronization of neurons and increased excitability in epileptogenesis. Aim of the present investigations was to test the antiepileptic effect of the classical inorganic calcium channel blockers cobalt (Co2+), manganese (Mn2+) and magnesium (Mg2+). METHODS: Experiments were carried out on hippocampal slices of guinea pigs. Epileptiform field potentials (EFP) were elicited by adding bicuculline (10 µmol/l) to the artificial cerebrospinal fluid (CSF). Kalium was elevated from normal (4 mmol/l) to 8 mmol/l. Co2+ (CoCl2; 2, 1, 0.5 and 0.1 mmol/l), Mn2+ (MnCl2; 2, 1, 0.5 and 0.1 mmol/l) and Mg2+ (MgCl2; 8, 6, 5, 4 and 2 mmol/l) were added to the superfusate. RESULTS: Concentrations of 2, 1 and 0.5 mmol/l Co2+, 2 and 1 mmol/l Mn2+ and 8 respectively 6 mmol/l Mg2+ were able to suppress EFP sufficient in a dose dependent manner. In concentrations of 0.1 mmol/l Co2+, 0.5 mmol/l and 0.1 mmol/l Mn2+ and 5 respectively 4 and 2 mmol/l Mg2+ suppression was incomplete. With washout of the inorganic calcium channel blockers the EFP reappeared. DISCUSSION: All tree inorganic calcium channel blockers were able to suppress EFP in a dosage dependent and reversible manner. Weak reappearance of EFP after washout of Co2+ might be due to additional cytotoxic effects. The following mechanisms may contribute: i) blockade of voltage-activated calcium channels in the postsynaptic membrane, ii) changes in the activation of voltage-dependent sodium channels, iii) blockade of synaptic transmission.


Asunto(s)
Cobalto/uso terapéutico , Epilepsia/tratamiento farmacológico , Hipocampo/efectos de los fármacos , Magnesio/uso terapéutico , Manganeso/uso terapéutico , Neuronas/efectos de los fármacos , Animales , Anticonvulsivantes/farmacología , Anticonvulsivantes/uso terapéutico , Bicuculina/farmacología , Cobalto/farmacología , Convulsivantes/farmacología , Cobayas , Magnesio/farmacología , Manganeso/farmacología
9.
Med Phys ; 47(4): 1807-1812, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32056218

RESUMEN

PURPOSE: Tattoo fiducials are commonly used in radiotherapy patient alignment, and recent studies have examined the use of UV-excited luminescent tattoo ink as a cosmetic substitute to make these visible under UV illumination. The goal of this study was to show how luminescent tattoo inks could be excited with MV radiation and imaged during beam delivery for direct visualization of field position. METHODS: A survey of nine UV-sensitive tattoo inks with various emission spectra were investigated using both UV and MV excitation. Images of liquid solutions were collected under MV excitation using an intensified-CMOS imager. Solid skin-simulating phantoms were imaged with both surface-painted ink and in situ tattooing during dose delivery by both a clinical linear accelerator and cobalt-60 source. RESULTS: The UV inks have peak fluorescence emission ranging from approximately 440 to 600 nm with lifetimes near 11-16 µs. The luminescence intensity is approximately 6x higher during the x-ray pulse than after the pulse, however, the signal-to-noise is only approximately twice as large. Spatial resolution for imaging was achieved at 1.6 mm accuracy in a skin test phantom. Optical filtering allows for continuous imaging using a cobalt source and provides a mechanism to discriminate ink colors using a monochromatic image sensor. CONCLUSIONS: This study demonstrates how low-cost inks can be used as fiducial markers and imaged both using time-gated and continuous modes during MV dose delivery. Phantom studies demonstrate the potential application of real-time field verification. Further studies are required to understand if this technique could be used as a tool for radiation dosimetry.


Asunto(s)
Cobalto/uso terapéutico , Tinta , Luminiscencia , Aceleradores de Partículas , Radioterapia Guiada por Imagen/métodos , Tatuaje , Marcadores Fiduciales , Fantasmas de Imagen , Rayos Ultravioleta
10.
Chem Res Toxicol ; 33(2): 333-342, 2020 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-31599574

RESUMEN

There is presently no antidote available to treat azide poisoning. Here, the Schiff-base compound Co(II)-2,12-dimethyl-3,7,11,17-tetraazabicyclo-[11.3.1]heptadeca-1(17)2,11,13,15-pentaenyl dibromide (Co(II)N4[11.3.1]) is investigated to determine if it has the capability to antagonize azide toxicity through a decorporation mechanism. The stopped-flow kinetics of azide binding to Co(II)N4[11.3.1] in the absence of oxygen exhibited three experimentally observable phases: I (fast); II (intermediate); and III (slow). The intermediate phase II accounted for ∼70% of the overall absorbance changes, representing the major process observed, with second-order rate constants of 29 (±4) M-1 s-1 at 25 °C and 70 (±10) M-1 s-1 at 37 °C. The data demonstrated pH independence of the reaction around neutrality, suggesting the unprotonated azide anion to be the attacking species. The binding of azide to Co(II)N4[11.3.1] appears to have a complicated mechanism leading to less than ideal antidotal capability; nonetheless, this cobalt complex does protect against azide intoxication. Administration of Co(II)N4[11.3.1] at 5 min post sodium azide injection (ip) to mice resulted in a substantial decrease of righting-recovery times, 12 (±4) min, compared to controls, 40 (±8) min. In addition, only two out of seven mice "knocked down" when the antidote was administered compared to the controls given toxicant only (100% knockdown).


Asunto(s)
Antídotos/farmacología , Antídotos/uso terapéutico , Cobalto/farmacología , Complejos de Coordinación/farmacología , Bases de Schiff/farmacología , Azida Sódica/antagonistas & inhibidores , Azida Sódica/envenenamiento , Animales , Antídotos/administración & dosificación , Antídotos/química , Cobalto/administración & dosificación , Cobalto/química , Cobalto/uso terapéutico , Complejos de Coordinación/administración & dosificación , Complejos de Coordinación/química , Complejos de Coordinación/uso terapéutico , Espectroscopía de Resonancia por Spin del Electrón , Concentración de Iones de Hidrógeno , Inyecciones Intraperitoneales , Masculino , Ratones , Bases de Schiff/administración & dosificación , Bases de Schiff/química , Bases de Schiff/uso terapéutico , Azida Sódica/administración & dosificación , Tasa de Supervivencia
11.
J Photochem Photobiol B ; 192: 141-146, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30735955

RESUMEN

Multidrug resistance (MDR) in bacteria is a major concern these days. One of the reasons is the mutation in efflux pump that prevents the retention of antibiotics and drugs in the bacterial cell. The current work is a step to overcome MDR in bacteria via inhibition of efflux pump and further photoinhibition by thiolated chitosan coated cobalt doped zinc oxide nanoparticles (Co-ZnO) in visible light. Co-ZnO were synthesized in a size range of 40-60 nm. Antibacterial activity of the Co-ZnO against methicillin resistant Staphylococcus aureus (MRSA) was found 100% at a concentration of 10 µg/ml upon activation in sunlight for 15 min. Interestingly, it was found that cobalt as a dopant was able to increase the photodynamic and photothermal activity of Co-ZnO, as in dark conditions, there was only 3-5% of inhibition at 10 µg/ml of nanoparticle concentration. Upon excitation in light, these nanoparticles were able to generate reactive oxygen species (ROS) with a quantum yield of 0.23 ±â€¯0.034. The nanoparticles were also generating heat, Because of the magnetic nature, thus helping in more killing. Thiolated chitosan further helped in blocking the efflux pump of MRSA. The current nanoparticles were also found biocompatible on human red blood cells (LD50 = 214 µg/ml). These data suggest that the MRSA killing ability was facilitated through efflux inhibition and oxidative stress upon excitation in visible light hence, were in accordance with previous findings.


Asunto(s)
Cobalto/química , Proteínas de Transporte de Membrana/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Fotólisis , Óxido de Zinc/farmacología , Proteínas Bacterianas , Cobalto/uso terapéutico , Eritrocitos , Humanos , Luz , Nanopartículas/uso terapéutico , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Óxido de Zinc/uso terapéutico
12.
Biomater Sci ; 7(4): 1554-1564, 2019 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-30681674

RESUMEN

The renoprotective effects of hypoxia inducible-factor (HIF) activators have been demonstrated by improving renal hypoxia in chronic kidney disease. Cobalt chloride is one of the most widely used HIF activators in biomedicine; however, poor kidney targeting and undesirable side effects greatly limit its clinical applications. Here, we report a novel stimuli-responsive drug release nanoplatform in which glutathione (GSH)-modified Au nanoparticles (GLAuNPs) and Co2+ self-assemble into nanoassemblies (GLAuNPs-Co) through coordination interactions between empty orbitals of Co2+ and lone pairs of GSH. The GLAuNPs, when used as a drug carrier, demonstrated high drug loading capacity and pH-triggered drug release after assembling with Co2+. The acidic environment of lysosomes in renal fibrosis tissues could disassemble GLAuNPs-Co and release Co2+. Moreover, encapsulation of the Co2+ ions in the GLAuNPs greatly lowered the cytotoxicity of Co2+ in kidney tubule cells. Tissue fluorescence imaging showed that GLAuNPs-Co specifically accumulated in the kidneys, especially in the renal proximal tubules. After GLAuNPs-Co was intraperitoneally injected into ureter-obstructed mice, significant attenuation of interstitial fibrosis was exhibited. The beneficial effects can be mainly ascribed to miR-29c expression restored by HIF-α activation. These findings revealed that GLAuNPs-Co have pH-responsive drug release and renal targeting capabilities; thus, they are a promising drug delivery platform for treating kidney disease.


Asunto(s)
Cobalto/uso terapéutico , Fibrosis/tratamiento farmacológico , Oro/química , Enfermedades Renales/tratamiento farmacológico , Nanopartículas del Metal/química , Animales , Células Cultivadas , Cobalto/química , Cobalto/farmacología , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Imagen Óptica , Ratas
13.
N Z Vet J ; 67(2): 105-108, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30557526

RESUMEN

AIMS: To investigate the production responses and cost-benefit of administering a controlled-release anthelmintic capsule (CRC) to pregnant yearling ewes prior to lambing. METHODS: Yearling ewes from two commercial sheep flocks (A, n=489; B, n=248) in the North Island of New Zealand were enrolled in the study. Prior to lambing, CRC containing albendazole and abamectin were administered to half the ewes while the other half remained untreated. Ewe liveweights and body condition scores were measured prior to lambing, at weaning and, for Flock B, prior to subsequent mating. Lambs were matched to dams shortly after birth and the weight and number of lamb weaned per ewe were determined. A cost-benefit analysis was undertaken for Flock B considering the increased weight of lamb weaned per ewe, and the weight of ewes at the next mating and the benefit in terms of lambs born. RESULTS: The mean weight at weaning of treated ewes was greater for treated than untreated ewes by 2.76 (95% CI 0.64-4.88) kg in Flock A (p<0.001) and 2.35 (95% CI -0.41-5.12) kg in Flock B (p=0.003); the weight of lamb weaned per ewe was greater for treated than untreated ewes by 1.43 (95% CI -0.71 to -3.49) kg in Flock A (p=0.041) and 3.97 (95% CI 1.59-6.37) kg in Flock B (p<0.001), and ewe liveweight prior to subsequent mating was greater for treated than untreated ewes in Flock B by 4.60 (95% CI 3.6-5.6) kg (p<0.001). There was no difference in the percentage of lambs reared to weaning between treated and untreated ewes in either flock (p>0.8). The overall cost-benefit of treatment for Flock B was NZ$9.44 per treated ewe. CONCLUSIONS AND CLINICAL RELEVANCE: Pre-lambing CRC administration to yearling ewes resulted in increased ewe weaning weights and weight of lamb weaned in both the flocks studied. There was an economic benefit in the one flock where this was assessed.


Asunto(s)
Albendazol/uso terapéutico , Cobalto/uso terapéutico , Helmintiasis Animal/prevención & control , Ivermectina/análogos & derivados , Selenio/uso terapéutico , Enfermedades de las Ovejas/prevención & control , Albendazol/administración & dosificación , Albendazol/economía , Animales , Antihelmínticos/economía , Antihelmínticos/uso terapéutico , Cobalto/administración & dosificación , Cobalto/economía , Análisis Costo-Beneficio , Preparaciones de Acción Retardada , Femenino , Helmintiasis Animal/economía , Ivermectina/administración & dosificación , Ivermectina/economía , Ivermectina/uso terapéutico , Nueva Zelanda/epidemiología , Embarazo , Selenio/administración & dosificación , Selenio/economía , Ovinos , Enfermedades de las Ovejas/economía , Enfermedades de las Ovejas/epidemiología
14.
Int J Med Sci ; 15(13): 1423-1432, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30443161

RESUMEN

Peripheral nerve injury is known to activate the hypoxia-inducible factor-1α (HIF-1α) pathway as one of pro-regenerative transcriptional programs, which could stimulate multiple injury-induced gene expression and contribute to axon regeneration and functional recovery. However, the role of HIF-1α in peripheral nerve regeneration remains to be fully elucidated. In this study, rats were divided into three groups and treated with sham surgery, surgery with cobalt chloride (CoCl2) and surgery with saline, respectively. Sciatic functional index, morphologic evaluations of muscle fibers, and never conduction velocity were performed to measure the functional recovery at 12 weeks postoperatively. In addition, the effects of CoCl2 on the expression of HIF-1α, glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were determined at mRNA levels; as well as HIF-1α, the dual leucine zipper kinase (DLK), the c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), BDNF and NGF were measured at protein level at 4 weeks postoperatively. Systemic administration of CoCl2 (15 mg/kg/day intraperitoneally) significantly promoted functional recovery of rats with sciatic nerve transection injury. This study demonstrated in rats treated with CoCl2, the expression of HIF-1α, GDNF, BDNF and NGF was significantly increased at mRNA level, while HIF-1α, DLK, p-JNK, BDNF and NGF was significantly increased at protein level.


Asunto(s)
Cobalto/uso terapéutico , Traumatismos de los Nervios Periféricos/tratamiento farmacológico , Animales , Femenino , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Regeneración Nerviosa/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Nervio Ciático/efectos de los fármacos , Nervio Ciático/lesiones
15.
Nanomedicine (Lond) ; 13(10): 1221-1238, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29882719

RESUMEN

Magnetic nanoparticles (MNPs) are very attractive especially for biomedical applications, among which, iron oxide nanoparticles have received substantial attention in the past decade due to the elemental composition that makes them biocompatible and degradable. However recently, other magnetic nanomaterials such as spinel ferrites that can provide improved magnetic properties such as coercivity and anisotropy without compromising on inherent advantages of iron oxide nanoparticles are being researched for better applicability of MNPs. Among various spinel ferrites, cobalt ferrite (CoFe2O4) nanoparticles (NPs) are one of the most explored MNPs. Therefore, the intention of this article is to provide a comprehensive review of CoFe2O4 NPs and their inherent properties that make them exceptional candidates, different synthesis methods that influence their properties, and applications of CoFe2O4 NPs and their relevant applications that have been considered in biotechnology and bioengineering.


Asunto(s)
Materiales Biocompatibles/uso terapéutico , Cobalto/uso terapéutico , Compuestos Férricos/uso terapéutico , Nanopartículas de Magnetita/uso terapéutico , Anisotropía , Materiales Biocompatibles/química , Cobalto/química , Compuestos Férricos/química , Humanos , Nanopartículas de Magnetita/química , Nanotecnología/tendencias
16.
Med Phys ; 45(1): 429-437, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29171060

RESUMEN

PURPOSE: Experimental dosimetry of high-dose-rate (HDR) 192 Ir brachytherapy (BT) sources is complicated due to high dose and dose-rate gradients, and softening of photon energy spectrum with depth. A single crystal synthetic diamond detector microDiamond (PTW 60019, Freiburg, Germany) has a small active volume, high sensitivity, direct readout, and nearly water-equivalent active volume. The purpose of this study was to evaluate the suitability of microDiamond detectors for the determination of absorbed dose to water around HDR 192 Ir BT sources. Three microDiamond detectors were used, allowing for the comparison of their properties. METHODS: In-phantom measurements were performed using microSelectron and VariSource iX HDR 192 Ir BT treatment units. Their treatment planning systems (TPSs), Oncentra (v. 4.3) and BrachyVision (v. 13.6), respectively, were used to create irradiation plans for a cubic PMMA phantom with the microDiamond positioned at one of three source-to-detector distances (SDDs) (1.5, 2.5, and 5.5 cm) at a time. The source was stepped in increments of 0.5 cm over a total length of 6 cm to yield absorbed dose of 2 Gy at the nominal reference-point of the detector. Detectors were calibrated in 60 Co beam in terms of absorbed dose to water, and Monte Carlo (MC) calculated beam quality correction factors were applied to account for absorbed-dose energy dependence. Phantom correction factors were applied to account for differences in dimensions between the measurement phantom and a water phantom used for absorbed dose calculations made with a TPS. The same measurements were made with all three of the detectors. Additionally, dose-rate dependence and stability of the detectors were evaluated in 60 Co beam. RESULTS: The percentage differences between experimentally determined and TPS-calculated absorbed doses to water were from -1.3% to +2.9%. The values agreed to within experimental uncertainties, which were from 1.9% to 4.3% (k = 2) depending on the detector, SDD and treatment delivery unit. No dose-rate or intrinsic energy dependence corrections were applied. All microDiamonds were comparable in terms of preirradiation dose, stability of the readings and energy response, and showed a good agreement. CONCLUSIONS: The results indicate that the microDiamond is potentially suitable for the determination of absorbed dose to water around HDR 192 Ir BT sources and may be used for independent verification of TPS's calculations, as well as for QA measurements of HDR 192 Ir BT treatment delivery units at clinical sites.


Asunto(s)
Braquiterapia/instrumentación , Radioisótopos de Iridio/uso terapéutico , Dosímetros de Radiación , Radiometría/instrumentación , Calibración , Cobalto/uso terapéutico , Simulación por Computador , Método de Montecarlo , Fantasmas de Imagen , Dosis de Radiación , Agua
17.
J Interv Cardiol ; 31(2): 170-176, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29166699

RESUMEN

BACKGROUNDS: New-generation bioresorbable polymer-everolimus eluting stents (BP-EES) are available. This study aimed to compare the clinical outcomes for BP-EES compared to more established stent designs, namely the platinum chromium-EES (PtCr-EES) and cobalt chrome-EES(CoCr-EES) in patients with the end-stage chronic kidney disease (CKD) including hemodialysis (HD). METHODS: One-hundred-forty-one consecutive stents (BP-EES [n = 44], PtCr-EES [n = 45], and CoCr-EES [n = 52]) were implanted in 104 patients with CKD. All patients underwent a follow-up coronary angiography at 12 months after implantation. End-stage CKD was defined as an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2 , or the need for HD. The following outcome variables were compared among the three stent groups after implantation and the 12-month follow-up: target lesion revascularization (TLR), stent thrombosis (ST), and major adverse cardiac event (MACE). Minimal stent diameter (MSD) and %diameter-stenosis (%DS) were measured using quantitative coronary angiography. RESULTS: The overall rate of TLR and MACE was 14.6% and 30.8%, respectively, with no incidence of ST. Immediately after implantation, the MSD (P = 0.22) and %DS (P = 0.42) were equivalent among the three groups. However, at the 12-month follow-up, a tendency towards higher TLR was observed for the BP-EES group (22.7%) compared with the PtCr-EES (8.8%) and CoCr-EES (9.6%) groups (P = 0.07). Late loss in lumen diameter was also significantly greater for the BP-EES (0.51 ± 0.64 mm) group than either the PtCr-EES (0.20 ± 0.61 mm) and CoCr-EES (0.25 ± 0.70 mm) groups (P = 0.03). CONCLUSIONS: BP-EES might increase the risk of in-stent restenosis in patients with end-stage of CKD or the need for HD.


Asunto(s)
Cromo/uso terapéutico , Cobalto/uso terapéutico , Enfermedad de la Arteria Coronaria , Reestenosis Coronaria , Vasos Coronarios , Everolimus/uso terapéutico , Fallo Renal Crónico , Intervención Coronaria Percutánea/efectos adversos , Platino (Metal)/uso terapéutico , Implantes Absorbibles/normas , Anciano , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/cirugía , Reestenosis Coronaria/diagnóstico , Reestenosis Coronaria/epidemiología , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/cirugía , Stents Liberadores de Fármacos/normas , Femenino , Estudios de Seguimiento , Humanos , Inmunosupresores/uso terapéutico , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Intervención Coronaria Percutánea/métodos , Diálisis Renal/métodos , Factores de Riesgo , Oligoelementos/uso terapéutico , Resultado del Tratamiento
18.
Arq. bras. med. vet. zootec. (Online) ; 69(6): 1683-1692, nov.-dez. 2017. tab
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-911302

RESUMEN

The quality of products derived from eggs depends on the quality of the raw material source and the industrial production. The contamination by fungi and bacteria can occur after exposure of the product in the retail market. The objective of this study was to evaluate the microbiological quality of 60 samples of derivated egg products and evaluate the effects of gamma radiation of cobalt-60, using the dose of 5 and 10 kGy, for decontamination of products collected in the retail market in the São Paulo city. The bacterial count was performed by the most probable number (MPN) and the fungal counts by serial dilution after plating surface. It was observed a decrease in the humidity and water activity (Aw) values of irradiated whole egg powder and white egg powder samples (p<0.05), but there was no significant change in the pH of the same samples irradiated with 5 and 10 kGy (p>0.05). In the powdered yolk the values of pH and Aw presented a significant difference (p<0.05), but no significant difference in the humidity values of 5 and 10 kGy irradiated samples (p>0.05). Effective microbial sterilization of all products occurred at the dose of 10 kGy.(AU)


A qualidade dos produtos derivados de ovos depende da qualidade da matéria-prima e da produção industrial. A contaminação por fungos e bactérias pode ocorrer após a exposição do produto no mercado varejista. O objetivo deste estudo foi avaliar a qualidade microbiológica de 60 amostras de derivados de ovos e avaliar os efeitos da radiação gama de cobalto-60, utilizando-se as doses de 5 e 10 kGy, para descontaminação dos produtos coletados no mercado varejista da cidade de São Paulo. A contagem bacteriana foi realizada pelo número mais provável (MPN), e as contagens fúngicas por diluição seriada em plaqueamento de superfície. Foi observada uma diminuição dos valores da umidade e da atividade de água (Aa) das amostras irradiadas de ovo integral em pó e clara em pó (p<0,05), mas sem alteração significativa do pH nas mesmas amostras irradiadas com 5 e 10 kGy (p>0,05). Em gema em pó, observou-se diferença significativa (p<0,05) nos valores de pH e Aa, mas não houve mudança expressiva nos valores de umidade nas amostras irradiadas com 5 e 10 kGy (p>0,05). A esterilização microbiana eficaz de todos os produtos ocorreu com a dose de 10 kGy.(AU)


Asunto(s)
Huevos/microbiología , Huevos/efectos de la radiación , Rayos gamma/uso terapéutico , Esterilización/métodos , Cobalto/uso terapéutico , Hongos/efectos de la radiación
19.
Sci Rep ; 7(1): 4257, 2017 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-28652596

RESUMEN

We demonstrate the effectiveness of out-of-plane magnetized magnetic microdiscs for cancer treatment through mechanical cell disruption under an applied rotating magnetic field. The magnetic particles are synthetic antiferromagnets formed from a repeated motif of ultrathin CoFeB/Pt layers. In-vitro studies on glioma cells are used to compare the efficiency of the CoFeB/Pt microdiscs with Py vortex microdiscs. It is found that the CoFeB/Pt microdiscs are able to damage 62 ± 3% of cancer cells compared with 12 ± 2% after applying a 10 kOe rotating field for one minute. The torques applied by each type of particle are measured and are shown to match values predicted by a simple Stoner-Wohlfarth anisotropy model, giving maximum values of 20 fNm for the CoFeB/Pt and 75 fNm for the Py vortex particles. The symmetry of the anisotropy is argued to be more important than the magnitude of the torque in causing effective cell destruction in these experiments. This work shows how future magnetic particles can be successfully designed for applications requiring control of applied torques.


Asunto(s)
Anisotropía , Glioma/terapia , Campos Magnéticos , Torsión Mecánica , Línea Celular Tumoral , Cobalto/química , Cobalto/uso terapéutico , Glioma/patología , Humanos , Hierro/química , Hierro/uso terapéutico
20.
World Neurosurg ; 103: 404-409, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28427980

RESUMEN

BACKGROUND: The use of titanium alloy (Ti) rods is frequently associated with rod fracture after spinal fixation. To address this issue, cobalt chrome (CoCr) rods, which are advantageous because of their greater strength and resistance to fatigue relative to Ti rods, have been introduced. The purpose of the present study was to compare radiographic outcomes after the use of Ti versus CoCr rods in a matched cohort of patients undergoing posterior spinal fusion for treatment of spinal instability. METHODS: We retrospectively reviewed data from patients who had undergone spinal fusion involving more than 3 levels at a single institution between 2004 and 2015. Patients were matched for age, diagnosis, 3-column osteotomy, levels fused, and T score. Fifty patients with Ti rods were identified and appropriately matched to 50 consecutive patients with CoCr rods. RESULTS: The distributions of age at surgery, sex, diagnosis, 3-column osteotomy, levels fused, number of patients with previous surgical procedures, and T score did not significantly differ between the 2 groups. However, there were significant differences in length of follow-up (CoCr, 25.0 vs. Ti, 28.5 months; P < 0.001), fusion rate (CoCr, 45 [90%] vs. Ti, 33 [66%]; P = 0.004), occurrence of rod breakage (CoCr, 0 vs. T, 8 [16%]; P = 0.006), and junctional kyphosis (CoCr, 24 [46%] vs. Ti, 9 [18%]; P = 0.003). CONCLUSIONS: Our findings indicate that the use of CoCr rods is effective in ensuring stability of the posterior spinal construct and accomplishment of spinal fusion. Furthermore, our results indicate that junctional kyphosis may occur more frequently in CoCr systems than in Ti systems.


Asunto(s)
Aleaciones de Cromo/uso terapéutico , Cobalto/uso terapéutico , Cifosis/etiología , Fusión Vertebral/instrumentación , Titanio/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Fijadores Internos , Inestabilidad de la Articulación/diagnóstico por imagen , Inestabilidad de la Articulación/cirugía , Cifosis/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Enfermedades de la Columna Vertebral/diagnóstico por imagen , Enfermedades de la Columna Vertebral/cirugía , Resultado del Tratamiento , Adulto Joven
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