N-Acetylcysteine Nanocarriers Protect against Oxidative Stress in a Cellular Model of Parkinson's Disease

Oxidative stress is a key mediator in the development and progression of Parkinson’s disease (PD). The antioxidant N-acetylcysteine (NAC) has generated interest as a disease-modifying therapy for PD but is limited due to poor bioavailability, a short half-life, and limited access to the brain. The aim of this study was to formulate and utilise mitochondria-targeted nanocarriers for delivery of NAC alone and in combination with the iron chelator deferoxamine (DFO), and assess their ability to protect against oxidative stress in a cellular rotenone PD model. Pluronic F68 (P68) and dequalinium (DQA) nanocarriers were prepared by a modified thin-film hydration method. An MTT assay assessed cell viability and iron status was measured using a ferrozine assay and ferritin immunoassay. For oxidative stress, a modified cellular antioxidant activity assay and the thiobarbituric acid-reactive substances assay and mitochondrial hydroxyl assay were utilised. Overall, this study demonstrates, for the first time, successful formulation of NAC and NAC + DFO into P68 + DQA nanocarriers for neuronal delivery. The results indicate that NAC and NAC + DFO nanocarriers have the potential characteristics to access the brain and that 1000 μM P68 + DQA NAC exhibited the strongest ability to protect against reduced cell viability (p = 0.0001), increased iron (p = 0.0033) and oxidative stress (p ≤ 0.0003). These NAC nanocarriers therefore demonstrate significant potential to be transitioned for further preclinical testing for PD

Management of spontaneously ruptured hepatocellular carcinomas in the radiofrequency ablation era

Background and aim: Spontaneous rupture of hepatocellular carcinoma (HCC) carries a high mortality. The use of radiofrequency ablation (RFA) in recent years has enriched the armamentarium for hemostasis of spontaneously ruptured HCCs but its results have not been documented. This study investigated the prognosis and outcome of spontaneous rupture of HCC as well as the results of using RFA for hemostasis. Patients and method: From January 1991 to December 2010, 5283 patients were diagnosed with HCC at our hospital, and 189 of them had spontaneous rupture of HCCs. They were grouped under two periods: period 1, 1991-2000, n = 70; period 2, 2001-2010, n = 119. RFA was available in period 2 only. Results: Hepatitis B virus infection was predominant in both periods. Surgical hemostasis was mainly achieved by hepatic artery ligation in period 1 and by RFA in period 2. The 30-day hospital mortality after surgical treatment was 55.6% (n = 18) in period 1 and 19.2% (n = 26) in period 2 (p = 0.012). Multivariate analysis identified 4 independent factors for better overall survival, namely, hemostasis by transarterial chemoembolization (hazard ratio 0.516, 95% confidence interval 0.354-0.751), hemostasis by RFA (hazard ratio 0.431, 95% confidence interval 0.236-0.790), having surgery as a subsequent treatment (hazard ratio 0.305, 95% confidence interval 0.186-0.498), and a serum total bilirubin level <19 umol/L (hazard ratio 1.596, 95% confidence interval 1.137-2.241). Conclusion: The use of RFA for hemostasis during laparotomy greatly reduced the hospital mortality rate when compared with conventional hepatic artery ligation. © 2014 Cheung et al.published_or_final_versio

Long Term Survival Analysis of Hepatectomy for Neuroendocrine Tumour Liver Metastases

Background. Liver is the commonest site for metastasis in patients with neuroendocrine tumour (NET). A vast majority of treatment strategies including liver directed nonsurgical therapy, liver directed surgical therapy, and nonliver directed therapy have been proposed. In this study we aim to investigate the outcome of liver resection in neuroendocrine tumour liver metastases (NELM). Method. 293 patients had hepatectomy for liver metastasis in our hospital between June 1996 and December 2010. Twelve patients were diagnosed to have NET in their final pathology and their data were reviewed. Results. The median ages of the patients were 48.5 years (range 20-71 years). Eight of the patients received major hepatectomy. Four patients received minor hepatectomy. The median operation time was 418 minutes (range 195-660 minutes). The median tumor size was 8.75 cm (range 0.9-21 cm). There was no hospital mortality. The overall one-year and three-year survivals were 91.7% and 55.6%. The one-year and three-year disease-free survivals were 33.3% and 16.7%. Conclusion. Hepatectomy is an effective and safe treatment for NELM. Reasonable outcome on long term overall survival and disease-free survival can be achieved in this group of patients with a low morbidity rate. © 2014 Tan To Cheung et al.published_or_final_versio

Procalcitonin as a marker of bacterial infection in the emergency department: an observational study

INTRODUCTION: Procalcitonin (PCT) has been proposed as a marker of infection in critically ill patients; its level is related to the severity of infection. We evaluated the value of PCT as a marker of bacterial infection for emergency department patients. METHODS: This prospective observational study consecutively enrolled 120 adult atraumatic patients admitted through the emergency department of a 3000-bed tertiary university hospital in May 2001. Fifty-eight patients were infected and 49 patients were not infected. The white blood cell counts, the serum C-reactive protein (CRP) level (mg/l), and the PCT level (ng/ml) were compared between the infected and noninfected groups of patients. RESULTS: A white blood cell count >12,000/mm(3 )or <4000/mm(3 )was present in 36.2% of the infected patients and in 18.4% of the noninfected patients. The best cut-off serum levels for PCT and CRP, identified using the Youden's Index, were 0.6 ng/ml and 60 mg/l, respectively. Compared with CRP, PCT had a comparable sensitivity (69.5% versus 67.2%), a lower specificity (64.6% versus 93.9%), and a lower area under the receiver operating characteristic curve (0.689 versus 0.879). PCT levels, but not CRP levels, were significantly higher in bacteremic and septic shock patients. Multivariate logistic regression identified that a PCT level ≥ 2.6 ng/ml was independently associated with the development of septic shock (odds ratio, 38.3; 95% confidence interval, 5.6–263.5; P < 0.001). CONCLUSIONS: PCT is not a better marker of bacterial infection than CRP for adult emergency department patients, but it is a useful marker of the severity of infection

Interface characterisation and internal electric field evaluation of a-Si:H pin solar cell by variable energy positron annhilation spectroscopy

Symposium Theme: Amorphous and microcrystalline silicon technologyBy means of the slow positron beam Doppler-broadening technique, the depth profile of microvoids across a p-i-n double junction solar cell has been resolved. VEPFIT fitting results indicate an approximately uniform density of the defects throughout the solar cell, but with an enhanced concentration at all of the interfaces possibly due to network mismatch. In order to evaluate the internal electric field, Variable Energy Positron Annihilation Spectroscopy (VEPAS) measurements have been performed on a single junction pin solar cell at different biases. The internal electric field effect on positrons has also been examined in terms of the bias dependence of positron drift in a-Si:H single junction pin solar cell.published_or_final_versio

Identification of vacancy-like defects in high-rate grown a-Si before and after ligh soaking by vepas

Symposium Theme: Amorphous and microcrystalline silicon technologyWe show how positron annihilation can distinguish vacancies in undoped hydrogenated amorphous silicon by performing Variable Energy Positron Annihilation Spectroscopy experiments before and after light soaking. We find that vacancy clusters, di-vacancies and a new type of single vacancies are created in undoped as-grown a-Si:H thin film by light illumination. The fact that the vacancy clusters are eliminated by the thermal annealing suggests that the Staebler-Wronski effect is closely related to vacancy clusters in a-Si:H material. The creation of vacancy clusters and redistribution of di-vacancies and even single vacancies probably result in photo-induced structural changes in this material.published_or_final_versio

Study of microvoids in high-rate a-Si:H using positron annihilation

Theme: Amorphous and microcrystalline silicon technologyIn this paper, we have carried out the positron annihilation measurement on high-rate and low-rate a-Si;H thin films deposited by PECVD. By means of the slow positron beam Doppler-broadening technique, the depth profiles of microvoids in a-Si:H have been determined. We have also studied the vacancy-type defect in the surface region in high-rate grown a-Si:H, making comparison between high-rate and low-rate a-Si:H. By plotting S and W parameters in the (S, W) plane, we have shown that the vacancies in all of the high-rate and low-rate deposited intrinsic samples, and in differently doped low-rate samples are of the same nature.published_or_final_versio

Screening of New Microsatellite DNA Markers from the Genome of Platyeriocheir formosa

The catadromous Platyeriocheir formosa is a crab endemic in Taiwan. To conserve P. formosa population diversity and ensure the sustainable use of this natural resource, we have developed new genetic markers, 17 polymorphic microsatellite loci, to promote the study of its population genetics in the future. In this study, more than 70 microsatellite sequences were found. Among these, 18 loci were selected to analyze the genetic diversity of P. formosa. With the exception of the Pfo15 locus, all of the remaining loci were polymorphic with allelic numbers ranging from 3–14. Heterozygosity within all 17 polymorphic loci ranged from 0.2–0.95 with an average of 0.55, which suggested that these loci are proper markers for studying population genetics. After we tested cross-specific amplification, eight and six primer sets could be successfully used for the amplification of microsatellite loci in morphologically similar Eriocheir sinensis and E. japonica, respectively; this suggests that they are useful markers for closely related species