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1.
Eur Cell Mater ; 38: 228-245, 2019 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-31697398

RESUMEN

Fracture healing is a well-orchestrated and coordinated process and begins with the inflammatory stage involving the infiltration of immune cells and the release of cytokines, including tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10). Low-magnitude high-frequency vibration (LMHFV) stimulation is effective in promoting fracture healing. The study hypothesis was that the innate immune response was impaired in osteoporotic fracture and LMHFV could positively modulate it. 9-month-old ovariectomy (OVX)-induced osteoporotic rats were randomised into sham (SHAM), OVX control (OVX), OVX-vibration (OVX-VT) or OVX vibration plus administration of COX-2 specific non-steroid anti-inflammatory drugs (OVX-VT-NSAID). LMHFV (35 Hz, 0.3 g) was given 20 min/d and 5 d/week to the treatment groups. Healing and innate immune response were evaluated by weekly radiographs, endpoint micro-computed tomography (µCT), enzyme-linked immunosorbent assay (ELISA) and histomorphometry at weeks 1, 2, 4 and 8 post-treatment. Results showed that OVX slightly elevated systemic inflammation but impaired the innate immune response locally at the fracture site, with significantly lower expressions of TNF-α and IL-6 but higher IL-10 expression during the early stage of healing. LMHFV was effective in accelerating the delayed fracture healing in OVX bones by partly restoring the impaired innate immune response at the fracture site, accompanied by promoted progression of macrophage polarisation from M1 (pro-inflammatory) to M2 (anti-inflammatory) phenotype. In conclusion, vibration treatment could positively modulate the impaired innate immune response and promote macrophage polarisation in osteoporotic-fracture healing.


Asunto(s)
Curación de Fractura , Macrófagos/citología , Fracturas Osteoporóticas/terapia , Vibración/uso terapéutico , Animales , Diferenciación Celular , Estrógenos/deficiencia , Femenino , Inmunidad Innata , Interleucina-10/genética , Interleucina-10/metabolismo , Macrófagos/metabolismo , Fracturas Osteoporóticas/etiología , Ratas , Ratas Sprague-Dawley
2.
Toxicol Mech Methods ; 28(3): 157-166, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28849708

RESUMEN

The leucine aminopeptidase inhibitor, benzyloxycarbonyl-leucine-chloromethylketone (z-L-CMK), was found to be toxic and readily induce cell death in Jurkat T cells. Dose-response studies show that lower concentration of z-L-CMK induced apoptosis in Jurkat T cells whereas higher concentration causes necrosis. In z-L-CMK-induced apoptosis, both the initiator caspases (-8 and -9) and effector caspases (-3 and -6) were processed to their respective subunits. However, the caspases remained intact in z-L-CMK-induced necrosis. The caspase inhibitor, z-VAD-FMK inhibited z-L-CMK-mediated apoptosis and caspase processing but has no effect on z-L-CMK-induced necrosis in Jurkat T cells. The high mobility group protein B1 (HMGB1) protein was found to be released into the culture medium by the necrotic cells and not the apoptotic cells. These results indicate that the necrotic cell death mediated by z-L-CMK at high concentrations is via classical necrosis rather than secondary necrosis. We also demonstrated that cell death mediated by z-L-CMK was associated with oxidative stress via the depletion of intracellular glutathione (GSH) and increase in reactive oxygen species (ROS), which was blocked by N-acetyl cysteine. Taken together, the results demonstrated that z-L-CMK is toxic to Jurkat T cells and induces apoptosis at low concentrations, while at higher concentrations the cells die of necrosis. The toxic side effects in Jurkat T cells mediated by z-L-CMK are associated with oxidative stress via the depletion of GSH and accumulation of ROS.


Asunto(s)
Clorometilcetonas de Aminoácidos/toxicidad , Apoptosis/efectos de los fármacos , Leucil Aminopeptidasa/antagonistas & inhibidores , Necrosis/inducido químicamente , Estrés Oxidativo/efectos de los fármacos , Inhibidores de Proteasas/toxicidad , Linfocitos T/efectos de los fármacos , Clorometilcetonas de Aminoácidos/antagonistas & inhibidores , Biomarcadores/metabolismo , Inhibidores de Caspasas/farmacología , Caspasas/química , Caspasas/metabolismo , Forma del Núcleo Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Glutatión/antagonistas & inhibidores , Glutatión/metabolismo , Humanos , Células Jurkat , Leucil Aminopeptidasa/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Nucleosomas/efectos de los fármacos , Nucleosomas/inmunología , Nucleosomas/metabolismo , Concentración Osmolar , Fragmentos de Péptidos/metabolismo , Inhibidores de Proteasas/química , Proteolisis/efectos de los fármacos , Linfocitos T/citología , Linfocitos T/inmunología , Linfocitos T/metabolismo
3.
Hong Kong Med J ; 24(1): 32-37, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28775216

RESUMEN

INTRODUCTION: Surgery for hip fracture may be performed out-of-hours to avoid surgical delay. There is, however, a perception that this may constitute less-than-ideal conditions and result in a poorer outcome. The aim of this study was to evaluate the surgical outcome of elderly patients with hip fracture who underwent daytime versus out-of-hours surgery in Hong Kong. This will help make decisions about whether to operate out-of-hours or to delay surgery until the following day. METHODS: This retrospective study included all elderly patients with hip fracture who were operated on and discharged from the Prince of Wales Hospital in 2014. Patients were divided into groups according to the time of surgical incision. Records were examined for 30-day mortality and postoperative surgical complications, and their potential associations with surgeon characteristics. RESULTS: Overall, 367 patients were selected in this study with 242 patients in the daytime group and 125 in the out-of-hours group. Demographic characteristics were comparable between the two groups. The overall 30-day mortality rate was 2.0% and the surgical complication rate was 24.2%. Compared with the daytime group, there was no increase in 30-day mortality or surgical complications for out-of- hours group. Fewer surgeons were involved in out-of-hours surgery but the number of surgeons and their qualifications did not affect the outcomes. CONCLUSIONS: The two groups were homogeneous in terms of demographic characteristics. Outcomes for 30-day mortality and postoperative surgical complications were comparable between the two groups. Surgeons' qualifications and number of surgeons involved were also not associated with the outcomes. Out-of-hours surgery remains a viable option in order to facilitate early surgery.


Asunto(s)
Urgencias Médicas , Fracturas de Cadera/mortalidad , Fracturas de Cadera/cirugía , Admisión y Programación de Personal , Complicaciones Posoperatorias/epidemiología , Atención Posterior , Anciano , Anciano de 80 o más Años , Femenino , Hong Kong/epidemiología , Humanos , Masculino , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
4.
Eur Cell Mater ; 34: 108-127, 2017 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-28880360

RESUMEN

This systematic review examines the efficacy and safety of whole body vibration (WBV) on fracture healing. A systematic literature search was conducted with relevant keywords in PubMed and Embase, independently, by two reviewers. Original animal and clinical studies about WBV effects on fracture healing with available full-text and written in English were included. Information was extracted from the included studies for review. In total, 19 articles about pre-clinical studies were selected. Various vibration regimes are reported; of those, the frequencies of 35 Hz and 50 Hz show better results than others. Most of the studies show positive effects on fracture healing after vibration treatment and the responses to vibration are better in ovariectomised (OVX) animals than non-OVX ones. However, several studies provide insufficient evidence to support an improvement of fracture healing after vibration and one study even reports disruption of fracture healing after vibration. In three studies, vibration results in positive effects on angiogenesis at the fracture site and surrounding muscles during fracture healing. No serious complications or side effects of vibration are found in these studies. WBV is suggested to be beneficial in improving fracture healing in animals without safety problem reported. In order to apply vibration on fractured patients, more well-designed randomised controlled clinical trials are needed to examine its efficacy, regimes and safety.


Asunto(s)
Curación de Fractura , Vibración , Animales , Fenómenos Biomecánicos/efectos de los fármacos , Estrógenos/farmacología , Curación de Fractura/efectos de los fármacos , Curación de Fractura/genética , Curación de Fractura/efectos de la radiación , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Neovascularización Fisiológica/efectos de los fármacos , Neovascularización Fisiológica/genética , Resultado del Tratamiento , Vibración/efectos adversos
5.
J Immunother Cancer ; 4: 67, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27777776

RESUMEN

BACKGROUND: VEGF-targeted therapy has become the mainstay of treatment for majority of mRCC patients. For most patients, benefit is short-lived and therefore treatment remains palliative in intent. HD IL2 is an effective immunotherapy treatment capable of durable remission in some patients but its unselected use has been difficult due to its modest response rate and considerable adverse effects. Using set pathology criteria as a selection tool in clinical practice, we have been able to show improved outcomes in our previous report. Here, we present an updated and extended report of this treatment and seek to explore any pathological, clinical and treatment variables likely to predict better outcomes. METHODS: This is an extension of a previously reported clinical audit, which includes mRCC cases treated with HD IL2 between 2003 and 2013. Since 2006, tumour specimens of potential candidates were routinely reviewed prospectively and stratified into Favourable or Other categories based on constitution of histological growth pattern, namely alveolar or solid versus papillary and/or sarcomatoid architecture; clear cell versus granular cell cytoplasmic morphology. HD IL2 was preferentially offered to patients with Favourable pathology. Outcome evaluation includes response rates, survival, and treatment tolerance. Multivariate analysis was performed to explore potential prognostic and predictive factors. RESULTS: Among prospectively selected patients with Favourable pathology (n = 106), overall response rate was 48.1 % (51/106) with CR rate of 21.6 % (23/106). Median OS was 58.1 months. Factors associated with significantly better response and/or survival includes favourable pathology pattern, higher cycle 1 tolerance and lower number of metastatic organ sites (<3). CAIX (Carbonic anhydrase 9) has prognostic value but is not predictive of response. Toxicities were those expected of IL2 but were manageable on general medical wards, with no treatment-related death. Importantly most complete responses were durable with 76 % (23/30) cases remained relapse-free (median 39 months follow up) and 2 of the seven who relapsed had had long-term disease free survival after resection of oligometastatic relapse. CONCLUSIONS: Our experience shows that HD IL2 remains an effective and safe treatment in well-selected cases of mRCC. The result in this single-institution patient series confirms similar outcomes to our previously reported retrospective series. Given the prospect of long-term remission, fit patients with Favourable histology and low disease burden should be considered for HD IL2 in an experienced centre. Better understanding has been gained from this in-depth analysis especially the examination of possible response predictors and strategies that can improve treatment outcome.


Asunto(s)
Antineoplásicos Inmunológicos/administración & dosificación , Carcinoma de Células Renales/tratamiento farmacológico , Carcinoma de Células Renales/patología , Factores Inmunológicos/administración & dosificación , Interleucina-2/administración & dosificación , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/patología , Adulto , Anciano , Biomarcadores de Tumor , Anhidrasa Carbónica IX/genética , Anhidrasa Carbónica IX/metabolismo , Carcinoma de Células Renales/mortalidad , Membrana Celular/metabolismo , Terapia Combinada , Femenino , Humanos , Estimación de Kaplan-Meier , Neoplasias Renales/mortalidad , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Selección de Paciente , Modelos de Riesgos Proporcionales , Resultado del Tratamiento , Adulto Joven
7.
Eur Cell Mater ; 31: 341-54, 2016 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-27215741

RESUMEN

Low-magnitude high-frequency vibration (LMHFV) has been proven to promote osteoporotic fracture healing. Mechanical stimulation was reported to enhance SDF-1/CXCR4 signalling in mesenchymal stem cells (MSCs). We hypothesised that LMHFV promoted osteoporotic fracture healing by enhancing MSC migration through the SDF-1/CXCR4 pathway. 152 ovariectomised SD-rats received closed femoral fracture in groups of vibration+MSC (VMG) (20 min/d, 5 d/week), vibration+MSC+AMD3100 (VMAG; AMD, a CXCR4 inhibitor) (1 mg/kg/d, intraperitoneal), MSC (MG) (1 × 106 MSC, intracardiac) or control (CG) for a treatment duration of 2, 4 or 8 weeks. MSC migration was evaluated by ex-vivo green fluorescent protein signal in the callus; and fracture healing was examined by weekly radiographs, endpoint computed-tomography and mechanical test. At week-2 and week-4, ex-vivo callus GFP intensity of VMG was significantly higher than other groups (p < 0.05). From week-2 to week-3, both callus width and callus area in VMG were significantly larger; and from week-7 to week-8, smaller than other groups (p < 0.05). At week-8, high-density bone volume fraction, bone volume fraction, bone mineral density and stiffness in VMG were significantly higher than other 3 groups (p < 0.05). This study demonstrated that LMHFV promoted MSC migration and fracture healing in osteoporotic rats. This effect was attenuated by CXCR4 inhibitor, providing strong evidence that SDF-1-mediated MSC migration was one of the important mechanisms through which LMHFV enhanced fracture healing.


Asunto(s)
Quimiocina CXCL12/metabolismo , Curación de Fractura , Células Madre Mesenquimatosas/citología , Fracturas Osteoporóticas/patología , Fracturas Osteoporóticas/terapia , Receptores CXCR4/metabolismo , Transducción de Señal , Vibración , Animales , Callo Óseo/patología , Proteínas Fluorescentes Verdes/metabolismo , Inmunohistoquímica , Ensayo de Materiales , Fracturas Osteoporóticas/diagnóstico por imagen , Ratas Sprague-Dawley , Microtomografía por Rayos X
8.
Osteoporos Int ; 27(10): 2989-3000, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27155884

RESUMEN

UNLABELLED: Estrogen receptor (ER) in ovariectomy-induced osteoporotic fracture was reported to exhibit delayed expression. Mechanical stimulation enhanced ER-α expression in osteoporotic fracture callus at the tissue level. ER was also found to be required for the effectiveness of vibrational mechanical stimulation treatment in osteoporotic fracture healing. INTRODUCTION: Estrogen receptor(ER) is involved in mechanical signal transduction in bone metabolism. Its expression was reported to be delayed in osteoporotic fracture healing. The purpose of this study was to investigate the roles played by ER during osteoporotic fracture healing enhanced with mechanical stimulation. METHODS: Ovariectomy-induced osteoporotic SD rats that received closed femoral fractures were divided into five groups, (i) SHAM, (ii) SHAM-VT, (iii) OVX, (iv) OVX-VT, and (v) OVX-VT-ICI, where VT stands for whole-body vibration treatment and ICI for ER antagonization by ICI 182,780. Callus formation and gene expression were assessed at 2, 4, and 8 weeks postfracture. In vitro osteoblastic differentiation, mineralization, and ER-α expression were assessed. RESULTS: The delayed ER expression was found to be enhanced by vibration treatment. Callus formation enhancement was shown by callus morphometry and micro-CT analysis. Enhancement effects by vibration were partially abolished when ER was modulated by ICI 182,780, in terms of callus formation capacity at 2-4 weeks and ER gene and protein expression at all time points. In vitro, ER expression in osteoblasts was not enhanced by VT treatment, but osteoblastic differentiation and mineralization were enhanced under estrogen-deprived condition. When osteoblastic cells were modulated by ICI 182,780, enhancement effects of VT were eliminated. CONCLUSIONS: Vibration was able to enhance ER expression in ovariectomy-induced osteoporotic fracture healing. ER was essential in mechanical signal transduction and enhancement in callus formation effects during osteoporotic fracture healing enhanced by vibration. The enhancement of ER-α expression by mechanical stimulation was not likely to be related to the increased expression in osteoblastic cells but rather to the systemic enhancement in recruitment of ER-expressing progenitor cells through increased blood flow and neo-angiogenesis. This finding might explain the observed difference in mechanical sensitivity of osteoporotic fracture to mechanical stimulation.


Asunto(s)
Callo Óseo/metabolismo , Curación de Fractura , Fracturas Osteoporóticas/terapia , Receptores de Estrógenos/metabolismo , Vibración , Animales , Callo Óseo/patología , Femenino , Mecanotransducción Celular , Fracturas Osteoporóticas/patología , Ovariectomía , Ratas , Ratas Sprague-Dawley
10.
Protein Expr Purif ; 119: 124-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26647367

RESUMEN

Dengue Virus (DENV) infection is responsible for the world's most significant insect-borne viral disease. Despite an increasing global impact, there are neither prophylactic nor therapeutic options available for the effective treatment of DENV infection. An attractive target for antiviral drugs is the virally encoded trypsin-like serine protease (NS3pro) and its associated cofactor (NS2B). The NS2B-NS3pro complex is responsible for cleaving the viral polyprotein into separate functional viral proteins, and is therefore essential for replication. Recombinant expression of an active NS2B-NS3 protease has primarily been based on constructs linking the C-terminus of the approximately 40 amino acid hydrophilic cofactor domain of NS2B to the N-terminus of NS3pro via a flexible glycine linker. The resulting complex can be expressed in high yield, is soluble and catalytically active and has been used for most in vitro screening, inhibitor, and X-ray crystallographic studies over the last 15 years. Despite extensive analysis, no inhibitor drug candidates have been identified yet. Moreover, the effect of the artificial linker introduced between the protease and its cofactor is unknown. Two alternate methods for bacterial expression of non-covalently linked, catalytically active, NS2B-NS3pro complex are described here along with a comparison of the kinetics of substrate proteolysis and binding affinities of substrate-based aldehyde inhibitors. Both expression methods produced high yields of soluble protein with improved substrate proteolysis kinetics and inhibitor binding compared to their glycine-linked equivalent. The non-covalent association between NS2B and NS3pro is predicted to be more relevant for examining inhibitors that target cofactor-protease interactions rather than the protease active site. Furthermore, these approaches offer alternative strategies for the high yield co-expression of other protein assemblies.


Asunto(s)
Virus del Dengue/enzimología , Serina Endopeptidasas/biosíntesis , Proteínas no Estructurales Virales/biosíntesis , Antivirales/química , Cromatografía de Afinidad , Escherichia coli , Expresión Génica , Concentración de Iones de Hidrógeno , Cinética , Inhibidores de Proteasas/química , Serina Endopeptidasas/química , Serina Endopeptidasas/aislamiento & purificación , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/aislamiento & purificación
11.
Eur J Cancer ; 51(2): 233-40, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25500146

RESUMEN

BACKGROUND: The national confidential enquiry into patient outcomes and death (NCEPOD) set important benchmarks in assessing the quality of care received by patients dying within 30 days of systemic anticancer therapy (SACT). Monthly morbidity and mortality audits conducted to recommendations in the NCEPOD were commenced at the Christie NHS Foundation Trust in 2009, specifically to assess and improve patient outcomes. METHODS: We evaluated the outcomes of patients who died within 30 days of SACT over a 4 year period 2009-2013. We collated audit findings to determine the number of treatment related deaths, clinical characteristics of patients, causes of death and quality of care received. We examined the benefit of the audit in decreasing 30 day mortality during the 4 years and considered factors that may be associated with an increased risk of SACT related death. RESULTS: A total of 31,183 patients were treated at the Christie from 2009 to 2013. Of these 4% died within 30 days of SACT. Death was treatment related in 11%. The decision to treat with SACT was appropriate in 87% of but there was room for improvement in care in 24%. Mortality decreased over the 4 years. Possible factors associated with 30 day mortality post SACT included performance status ⩾2, presence of comorbidities, treatment type and treatment setting. CONCLUSIONS: We demonstrated that our audit process is feasible and robust. Further areas of research to determine predictive scores for patient treatment selection and improve outcomes were highlighted and are ongoing.


Asunto(s)
Antineoplásicos/uso terapéutico , Inmunoterapia/métodos , Neoplasias/terapia , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Adolescente , Adulto , Anciano , Antineoplásicos/efectos adversos , Causas de Muerte , Femenino , Humanos , Inmunoterapia/efectos adversos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Neoplasias/mortalidad , Evaluación de Resultado en la Atención de Salud/métodos , Calidad de la Atención de Salud/estadística & datos numéricos , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia , Factores de Tiempo , Adulto Joven
12.
Osteoarthritis Cartilage ; 22(7): 1061-7, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24852700

RESUMEN

OBJECTIVES: To evaluate the effects of low-magnitude high-frequency vibration (LMHFV) on degenerated articular cartilage and subchondral bone in anterior cruciate ligament transection (ACLT) induced osteoarthritis (OA) rat model. METHODS: 6 months old female Sprague-Dawley rats received ACLT on right knee and randomly divided into treatment and control groups. OA developed 12 weeks after surgery. LMHFV (35 Hz, 0.3 g) treatment was given 20 min/day and 5 days/week. After 6, 12 and 18 weeks, six rats of each group were sacrificed at each time point and the right knees were harvested. OA grading score, distal femur cartilage volume (CV), subchondral bone morphology, elastic modulus of cartilage and functional changes between groups were analyzed. RESULTS: Increased cartilage degradation (higher OA grading score) and worse functional results (lower duty cycle, regular index and higher limb idleness index) were observed after LMHFV treatment (P = 0.011, 0.020, 0.012 and 0.005, respectively). CV increased after LMHFV treatment (P = 0.019). Subchondral bone density increased with OA progress (P < 0.01). Increased BV/TV, Tb.N and decreased Tb.Sp were observed in distal femur epiphysis in LMHFV treatment group (P = 0.006, 0.018 and 0.011, respectively). CONCLUSION: LMHFV accelerated cartilage degeneration and caused further functional deterioration of OA affected limb in ACLT-induced OA rat model. In contrast, LMHFV promoted bone formation in OA affected distal femur epiphysis, but did not reverse OA progression.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Cartílago Articular/patología , Placa de Crecimiento/patología , Osteoartritis/etiología , Osteoartritis/patología , Osteogénesis/fisiología , Estimulación Física/efectos adversos , Vibración/efectos adversos , Animales , Ligamento Cruzado Anterior/cirugía , Cartílago Articular/diagnóstico por imagen , Cartílago Articular/fisiopatología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Epífisis/diagnóstico por imagen , Epífisis/patología , Epífisis/fisiopatología , Femenino , Fémur/diagnóstico por imagen , Fémur/patología , Fémur/fisiopatología , Placa de Crecimiento/diagnóstico por imagen , Placa de Crecimiento/fisiopatología , Osteoartritis/fisiopatología , Ratas , Ratas Sprague-Dawley , Estrés Mecánico , Factores de Tiempo , Microtomografía por Rayos X
13.
Toxicol Appl Pharmacol ; 278(2): 100-6, 2014 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-24768707

RESUMEN

The caspase inhibitor benzyloxycarbony (Cbz)-l-Val-Ala-Asp (OMe)-fluoromethylketone (z-VAD-FMK) has recently been shown to inhibit T cell proliferation without blocking caspase-8 and caspase-3 activation in primary T cells. We showed in this study that z-VAD-FMK treatment leads to a decrease in intracellular glutathione (GSH) with a concomitant increase in reactive oxygen species (ROS) levels in activated T cells. The inhibition of anti-CD3-mediated T cell proliferation induced by z-VAD-FMK was abolished by the presence of low molecular weight thiols such as GSH, N-acetylcysteine (NAC) and l-cysteine, whereas d-cysteine which cannot be metabolised to GSH has no effect. These results suggest that the depletion of intracellular GSH is the underlying cause of z-VAD-FMK-mediated inhibition of T cell activation and proliferation. The presence of exogenous GSH also attenuated the inhibition of anti-CD3-induced CD25 and CD69 expression mediated by z-VAD-FMK. However, none of the low molecular weight thiols were able to restore the caspase-inhibitory properties of z-VAD-FMK in activated T cells where caspase-8 and caspase-3 remain activated and processed into their respective subunits in the presence of the caspase inhibitor. This suggests that the inhibition of T cell proliferation can be uncoupled from the caspase-inhibitory properties of z-VAD-FMK. Taken together, the immunosuppressive effects in primary T cells mediated by z-VAD-FMK are due to oxidative stress via the depletion of GSH.


Asunto(s)
Clorometilcetonas de Aminoácidos/farmacología , Inhibidores de Caspasas/farmacología , Proliferación Celular , Inhibidores de Crecimiento/farmacología , Activación de Linfocitos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Subgrupos de Linfocitos T/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta Inmunológica , Glutatión/metabolismo , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Activación de Linfocitos/inmunología , Activación de Linfocitos/fisiología , Estrés Oxidativo/inmunología , Especies Reactivas de Oxígeno/metabolismo , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/inmunología
14.
Stem Cell Res ; 11(2): 888-901, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23838123

RESUMEN

Stem cell (SC) therapy is the main treatment modality for patients with limbal stem cell deficiency. If limbal epithelial stem cells (LESC) can be more readily identified, isolated and maintained ex vivo, patients could be treated with better quality grafts. With prior knowledge that vitronectin (VN) is present within the LESC niche and that it supports LESC in vitro, we postulated that VN receptors (integrins αvß3/5) are expressed by, and can be used to identify and isolate LESC. Immunolocalization studies were conducted on human corneas. Corneas were also used to expand limbal epithelial cells from either biopsies or enzyme-dissociated tissue and αvß3/5 expression determined by flow cytometry. Integrin expressing cells were isolated by magnetic activated cell sorting then assessed by immunocytology, colony forming efficiency, RT-PCR and microarray analysis. Integrin αvß5(+) cells co-localized to N-cadherin(+)/CK-15(+) putative LESC. αvß5 was restricted to less than 4% of the total limbal epithelial cells, which expressed higher levels of CK-15 and formed more colonies compared to αvß5(-) cells. Transcriptional profiling of αvß5(+/-) cells by microarray identified several highly expressed interferon-inducible genes, which localize to putative LESC. Integrin αvß5 is a candidate LESC marker since its expression is restricted to the limbus and αvß5(+) limbal epithelial cells have phenotypic and functional properties of LESC. Knowledge of the niche's molecular composition and the genes expressed by its SC will facilitate isolation and maintenance of these cells for therapeutic purposes.


Asunto(s)
Quimiocina CXCL10/biosíntesis , Epitelio Corneal/metabolismo , Limbo de la Córnea/citología , Receptores de Vitronectina/biosíntesis , Células Madre/metabolismo , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Humanos , Inmunohistoquímica , Limbo de la Córnea/metabolismo , Receptores de Vitronectina/genética , Receptores de Vitronectina/metabolismo , Trasplante de Células Madre/métodos
15.
J Nucl Cardiol ; 19(4): 735-42, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22565241

RESUMEN

BACKGROUND: Transient ischaemic dilation (TID) on myocardial perfusion imaging (MPI) is an important finding, conveying a high risk of subsequent cardiac events. However, the mechanism leading to TID on MPI is not well elucidated. This study aimed to determine if TID is due to true LV cavity dilation and ventricular stunning, or is due to relative subendocardial hypoperfusion. METHODS: 31 patients undergoing single-day Tc-99m adenosine sestamibi MPI were recruited. All had routine ECG-gated single-day rest-stress adenosine MPI, with transthoracic echocardiograms (echo) acquired concurrently at rest, and both immediately, and 2 hours, post-stress. Echocardiography was performed using a Vivid-7 (GE). LV volumes and LVEF were quantified blinded to MPI results, using biplane Simpson method on echo, and quantitatively (including TID) with QGS(®), on MPI. RESULTS: Patients were divided into quartiles for TID, with the top quartile considered TID positive [TID+ 9/31 (TID ratio 1.3 ± 0.09)], and TID negative [TID- 22/31 (TID ratio 1.01 ± 0.04)]. There was good correlation between resting echo and MPI physical measurements (LVEDV r(2) = 0.79, LVESV r(2) = 0.9, and LVEF r(2) = 0.75). On MPI, a significant drop in LVEF was observed between rest and early stress in the TID+ group (56.6% vs 46.5%, P < .002), as well as an increase in both LVESV (62 vs 79 mls, P < .0001) and LVEDV (113 vs 131 mls, P < .0001). However, no statistically significant change in LVEF, LVESV or LVEDV was identified on concurrent echo imaging (LVEF 57% vs 56%, P < .66; LVESV 48 vs 54 mls, P < .26; LVEDV 87 vs 97 mls, P < .299). No significant change in LVEF or ventricular volumes was noted in the TID- group by either echo or MPI. CONCLUSION: Transient dilation of the left ventricle on adenosine MPI is not related to chamber enlargement and myocardial stunning, but is more likely a function of subendocardial hypoperfusion and impaired coronary flow reserve.


Asunto(s)
Adenosina/farmacología , Ventrículos Cardíacos/patología , Imagen de Perfusión Miocárdica/métodos , Aturdimiento Miocárdico/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Radiofármacos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón Único/métodos , Función Ventricular Izquierda/fisiología , Cardiología/métodos , Ecocardiografía/métodos , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Isquemia Miocárdica , Aturdimiento Miocárdico/diagnóstico , Perfusión , Volumen Sistólico
16.
Curr Rev Musculoskelet Med ; 5(1): 32-8, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22231958

RESUMEN

Hip resurfacing (HR) has become a widely used surgical intervention for younger patients requiring hip joint arthroplasty. While case reports have been published describing rehabilitation programs following HR, there has yet to be established rehabilitation guidelines. Through experience and clinical reasoning, the following guidelines have been developed based on the patients at the Hospital for Special Surgery. The demographics of the typical HR patient, along with the surgical process are described. Current published literature reporting rehabilitation for patients with arthritic hip pathologies has been incorporated into the guidelines and is presented. The guidelines are divided into three phases, with goals for each phase explained. A progression through phases by way of reaching certain milestones and goals is advocated.

17.
Clin Radiol ; 67(3): 216-23, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21939962

RESUMEN

AIM: To devise a method to convert the time-intensity curves (TICs) of head and neck dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data into a pixel-by-pixel colour-coded map for identifying normal tissues and tumours. MATERIALS AND METHODS: Twenty-three patients with head and neck squamous cell carcinoma (HNSCC) underwent DCE-MRI. TIC patterns of primary tumours, metastatic nodes, and normal tissues were assessed and a program was devised to convert the patterns into a classified colour-coded map. The enhancement patterns of tumours and normal tissue structures were evaluated and categorized into nine grades (0-8) based on the predominance of coloured pixels on maps. RESULTS: Five identified TIC patterns were converted into a colour-coded map consisting of red (maximum enhancement), brown (continuous slow rise-up), yellow (rapid wash-in and wash-out), green (rapid wash-in and plateau), and blue (rapid wash-in and rise-up). The colour-coded map distinguished all 21 primary tumours and 15 metastatic nodes from normal structures. Primary tumours and metastatic nodes were colour coded as predominantly yellow (grades 1-2) in 17/21 and 6/15, green (grades 3-5) in 3/21 and 5/15, and blue (grades 6-7) in 1/21 and 4/15, respectively. Vessels were coded red in 46/46 (grade 0) and muscles were coded brown in 23/23 (grade 8). Salivary glands, thyroid glands, and palatine tonsils were coded into predominantly yellow (grade 1) in 46/46 and 10/10 and 18/22, respectively. CONCLUSION: DCE-MRI derived five-colour-coded mapping provides an objective easy-to-interpret method to assess the dynamic enhancement pattern of head and neck cancers.


Asunto(s)
Carcinoma de Células Escamosas/diagnóstico , Neoplasias de Cabeza y Cuello/diagnóstico , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Algoritmos , Color , Medios de Contraste , Gadolinio DTPA , Humanos
18.
Int J Cancer ; 131(1): 106-16, 2012 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21858807

RESUMEN

In the Phase III PATRICIA study (NCT00122681), the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine (Cervarix(®), GlaxoSmithKline Biologicals) was highly efficacious against HPV-16/18 infections and precancerous lesions in women HPV-16/18 deoxyribose nucleic acid (DNA) negative and seronegative at baseline. We present further data on vaccine efficacy (VE) against HPV-16/18 in the total vaccinated cohort including women who may have been exposed to HPV-16/18 infection before vaccination. In women with no evidence of current or previous HPV-16/18 infection (DNA negative and seronegative), VE was 90.3% (96.1% confidence interval: 87.3-92.6) against 6-month persistent infection (PI), 91.9% (84.6-96.2) against cervical intraepithelial neoplasia (CIN)1+ and 94.6% (86.3-98.4) against CIN2+ [97.7% (91.1-99.8) when using the HPV type assignment algorithm (TAA)]. In women HPV-16/18 DNA negative but with serological evidence of previous HPV-16/18 infection (seropositive), VE was 72.3% (53.0-84.5) against 6-month PI, 67.2% (10.9-89.9) against CIN1+, and 68.8% (-28.3-95.0) against CIN2+ [88.5% (10.8-99.8) when using TAA]. In women with no evidence of current HPV-16/18 infection (DNA negative), regardless of their baseline HPV-16/18 serological status, VE was 88.7% (85.7-91.1) against 6-month PI, 89.1% (81.6-94.0) against CIN1+ and 92.4% (84.0-97.0) against CIN2+ [97.0% (90.6-99.5) when using TAA]. In women who were DNA positive for one vaccine type, the vaccine was efficacious against the other vaccine type. The vaccine did not impact the outcome of HPV-16/18 infections present at the time of vaccination. Vaccination was generally well tolerated regardless of the woman's HPV-16/18 DNA or serological status at entry.


Asunto(s)
Papillomavirus Humano 16/inmunología , Papillomavirus Humano 18/inmunología , Infecciones por Papillomavirus/inmunología , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus/inmunología , Adyuvantes Inmunológicos , Adolescente , Adulto , Anticuerpos Antivirales/sangre , Estudios de Cohortes , ADN Viral/sangre , Femenino , Humanos , Infecciones por Papillomavirus/patología , Infecciones por Papillomavirus/virología , Vacunas contra Papillomavirus/administración & dosificación , Vacunas contra Papillomavirus/efectos adversos , Resultado del Tratamiento , Vacunación , Adulto Joven , Displasia del Cuello del Útero/patología , Displasia del Cuello del Útero/prevención & control
19.
Leukemia ; 25(6): 945-52, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21403650

RESUMEN

This phase I/II study evaluated imatinib as a c-kit inhibitor combined with mitoxantrone, etoposide and cytarabine therapy for patients with primary refractory or relapsed c-kit+ acute myeloid leukemia (AML). Imatinib was escalated through three dose levels in successive six patient cohorts. The combination was well tolerated up to 400 mg/day imatinib. Of 21 patients treated at this dose, 13 (62%) achieved complete response (CR), 7 (33%) were non-responders and one died during induction. The CR rate was 80% in patients with standard-risk karyotype versus 33% in patients with adverse karyotype. The CR rate for primary non-responders was 6/14 (43%) versus 7/7 (100%) for relapsed patients. AML blasts from peripheral blood were assayed for phosphorylated Akt (pAkt) and phosphorylated ERK (pERK) by flow cytometry before to and after imatinib dosing. Of eight patients achieving CR with reinduction, seven demonstrated marked (≥60%) pAkt inhibition with imatinib therapy. In contrast, all the six non-responders to reinduction demonstrated <60% pAkt inhibition (P=0.005). There was no correlation between pERK inhibition and response to therapy. These results indicate that lack of pAkt inhibition in vivo is associated with resistance to reinduction therapy using this regimen. Further studies using agents that are able to inhibit Akt more effectively are warranted.


Asunto(s)
Leucemia Mieloide Aguda/tratamiento farmacológico , Piperazinas/administración & dosificación , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-kit , Pirimidinas/administración & dosificación , Terapia Recuperativa/métodos , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Benzamidas , Femenino , Humanos , Mesilato de Imatinib , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Fosforilación , Pronóstico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Inducción de Remisión/métodos , Resultado del Tratamiento
20.
Med J Malaysia ; 66(1): 27-31, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23765139

RESUMEN

A survey was carried out to determine the prevalence of bronchial asthma and their contributing risk factors among Orang Asli subgroups living in Malaysia using IUATLD questionnaire and spirometry without being discriminatory towards age or gender. Of the 1171 distributed questionnaires, 716 (61.1%) comprising of 62.7% Semai Pahang, 51.3% Temiar, 74.2% Mah Meri, 65.6% Semai Perak, 53.6% Temuan, 53.8% Semelai, 61.1% Jakun and 67.4% Orang Kuala subgroups completed their questionnaire and were included in the data analysis. Participants comprised 549 (76.7%) children and 167 (23.3%) adults, age between 1 to 83 years old, 304 (42.5%) males and 412 (57.5%) females. The overall prevalence of bronchial asthma was 1.4% of which 1.5% was children, 1.3% adults, 1.0% male and 1.7% female, respectively. Of the 8 subgroups surveyed, 5 out of 10 confirmed asthma cases were Semai Pahang, followed by 3 cases among Mah Meri, and one case each among Temuan and Semai Perak subgroups, respectively. This study also demonstrated that the prevalence of self-reported and confirmed bronchial asthma tend to be higher among those who had close contact with pets, smoking individuals and among those who had a family history of asthma.


Asunto(s)
Asma , Estudios Transversales , Humanos , Malasia/epidemiología , Prevalencia , Factores de Riesgo
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