73 research outputs found

    Doxorubicin loaded Polymeric Nanoparticulate Delivery System to overcome drug resistance in osteosarcoma

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    <p>Abstract</p> <p>Background</p> <p>Drug resistance is a primary hindrance for the efficiency of chemotherapy against osteosarcoma. Although chemotherapy has improved the prognosis of osteosarcoma patients dramatically after introduction of neo-adjuvant therapy in the early 1980's, the outcome has since reached plateau at approximately 70% for 5 year survival. The remaining 30% of the patients eventually develop resistance to multiple types of chemotherapy. In order to overcome both the dose-limiting side effects of conventional chemotherapeutic agents and the therapeutic failure incurred from multidrug resistant (MDR) tumor cells, we explored the possibility of loading doxorubicin onto biocompatible, lipid-modified dextran-based polymeric nanoparticles and evaluated the efficacy.</p> <p>Methods</p> <p>Doxorubicin was loaded onto a lipid-modified dextran based polymeric nano-system. The effect of various concentrations of doxorubicin alone or nanoparticle loaded doxorubicin on KHOS, KHOS<sub>R2</sub>, U-2OS, and U-2OS<sub>R2 </sub>cells was analyzed. Effects on drug retention, immunofluorescence, Pgp expression, and induction of apoptosis were also analyzed.</p> <p>Results</p> <p>Dextran nanoparticles loaded with doxorubicin had a curative effect on multidrug resistant osteosarcoma cell lines by increasing the amount of drug accumulation in the nucleus via Pgp independent pathway. Nanoparticles loaded with doxorubicin also showed increased apoptosis in osteosarcoma cells as compared with doxorubicin alone.</p> <p>Conclusion</p> <p>Lipid-modified dextran nanoparticles loaded with doxorubicin showed pronounced anti-proliferative effects against osteosarcoma cell lines. These findings may lead to new treatment options for MDR osteosarcoma.</p

    c-Jun N-terminal kinase activation has a prognostic implication and is negatively associated with FOXO1 activation in gastric cancer

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    BACKGROUND: Since the biological function of c-Jun N-terminal kinase (JNK) in gastric cancer remains unclear, we investigated the clinical significance of JNK activation and its association with FOXO1 activation. METHODS: Immunohistochemical tissue array analysis of 483 human gastric cancer specimens was performed, and the results of the immunostaining were quantified. The correlation between JNK activation (nuclear staining for pJNK) and clinicopathological features, the proliferation index, prognosis or FOXO1 inactivation (cytoplasmic staining for pFOXO1) was analyzed. The SNU-638 gastric cancer cell line was used for in vitro analysis. RESULTS: Nuclear staining of pJNK was found in 38 % of the gastric carcinomas and was higher in the early stages of pTNM (P < 0.001). pJNK staining negatively correlated with lymphatic invasion (P = 0.034) and positively correlated with intestinal type by Lauren’s classification (P = 0.037), Ki-67-labeling index (P < 0.001), cyclin D1 (P = 0.045), cyclin E (P < 0.001) and pFOXO1 (P < 0.001). JNK activation correlated with a longer patients survival (P =0.008) and patients with a JNK-active and FOXO1-inactive tumor had a higher survival rate than the remainder of the population (P = 0.004). In vitro analysis showed that JNK inhibition by SP600125 in SNU-638 cells decreased cyclin D1 protein expression and increased FOXO1 activation. Further, JNK inhibition markedly suppressed colony formation, which was partially restored by FOXO1 shRNA expression. CONCLUSIONS: Our results indicate that JNK activation may serve as a valuable prognostic factor in gastric cancer, and that it is implicated in gastric tumorigenesis, at least in part, through FOXO1 inhibition

    Correction: International Society of Sports Nutrition position stand: Nutrient timing

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    Position Statement: The position of the Society regarding nutrient timing and the intake of carbohydrates, proteins, and fats in reference to healthy, exercising individuals is summarized by the following eight points: 1.) Maximal endogenous glycogen stores are best promoted by following a high-glycemic, high-carbohydrate (CHO) diet (600 – 1000 grams CHO or ~8 – 10 g CHO/kg/d), and ingestion of free amino acids and protein (PRO) alone or in combination with CHO before resistance exercise can maximally stimulate protein synthesis. 2.) During exercise, CHO should be consumed at a rate of 30 – 60 grams of CHO/hour in a 6 – 8% CHO solution (8 – 16 fluid ounces) every 10 – 15 minutes. Adding PRO to create a CHO:PRO ratio of 3 – 4:1 may increase endurance performance and maximally promotes glycogen re-synthesis during acute and subsequent bouts of endurance exercise. 3.) Ingesting CHO alone or in combination with PRO during resistance exercise increases muscle glycogen, offsets muscle damage, and facilitates greater training adaptations after either acute or prolonged periods of supplementation with resistance training. 4.) Post-exercise (within 30 minutes) consumption of CHO at high dosages (8 – 10 g CHO/kg/day) have been shown to stimulate muscle glycogen re-synthesis, while adding PRO (0.2 g – 0.5 g PRO/kg/day) to CHO at a ratio of 3 – 4:1 (CHO: PRO) may further enhance glycogen re-synthesis. 5.) Post-exercise ingestion (immediately to 3 h post) of amino acids, primarily essential amino acids, has been shown to stimulate robust increases in muscle protein synthesis, while the addition of CHO may stimulate even greater levels of protein synthesis. Additionally, pre-exercise consumption of a CHO + PRO supplement may result in peak levels of protein synthesis. 6.) During consistent, prolonged resistance training, post-exercise consumption of varying doses of CHO + PRO supplements in varying dosages have been shown to stimulate improvements in strength and body composition when compared to control or placebo conditions. 7.) The addition of creatine (Cr) (0.1 g Cr/kg/day) to a CHO + PRO supplement may facilitate even greater adaptations to resistance training. 8.) Nutrient timing incorporates the use of methodical planning and eating of whole foods, nutrients extracted from food, and other sources. The timing of the energy intake and the ratio of certain ingested macronutrients are likely the attributes which allow for enhanced recovery and tissue repair following high-volume exercise, augmented muscle protein synthesis, and improved mood states when compared with unplanned or traditional strategies of nutrient intake

    Microenvironmental acidosis in carcinogenesis and metastases: new strategies in prevention and therapy

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    LONG-TERM FOLLOW-UP OF NONSEMINOTAMOUS TESTICULAR CANCER-PATIENTS WITH MATURE TERATOMA OR CARCINOMA AT POSTCHEMOTHERAPY SURGERY

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    From 1979 to 1983 the EORTC GU Group treated 239 patients with disseminated non-seminomatous testicular cancer with combination chemotherapy comprising cisplatin, vinblastine and bleomycin in a prospectively controlled trial. The protocol required complete resection of residual masses after induction chemotherapy, provided that serum tumour markers were normal. 102 patients were operated on. 27 patients had mature teratoma (teratoma differentiated) in the resected specimens and 23 had viable cancer. Follow-up data were available for 26 and 22 of these patients, respectively. 23 of 26 patients (88%) with mature teratoma are alive and disease free after a follow-up of 53-110 months (median 92 months). 3 patients developed progressive disease; 1 died. A peculiar case of growing mature teratoma on the forearm is described. 13 of 22 patients (59%) with residual carcinoma are alive and disease free after a follow-up of 74-112 months (median 95 months). The prognosis of patients with carcinoma is shown to be correlated with the completeness of surgery, which in turn is correlated with the initial tumour mass before chemotherapy.</p

    Frequency of anxiety after stroke: a systematic review and meta-analysis of observational studies.

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    BACKGROUND AND PURPOSE: Negative psychological outcomes occur frequently after stroke; however, there is uncertainty regarding the occurrence of anxiety disorders and anxiety symptoms after stroke. A systematic review of observational studies was conducted that assessed the frequency of anxiety in stroke patients using a diagnostic or screening tool. SUMMARY OF REVIEW: Databases were searched up to March 2011. A random effects model was used to summarize the pooled estimate. Statistical heterogeneity was assessed using the I(2) statistic. Forty-four published studies comprising 5760 stroke patients were included. The overall pooled estimate of anxiety disorders assessed by clinical interview was 18% (95%confidence interval 8-29%, I(2)  = 97%) and was 25% (95% confidence interval 21-28%, I(2)  = 90%) for anxiety assessed by rating scale. The Hospital Anxiety and Depression Scale-Anxiety subscale 'probable' and 'possible' cutoff scores were the most widely used assessment criteria. The combined rate of anxiety by time after stroke was: 20% (95% confidence interval 13-27%, I(2)  = 96%) within one-month of stroke; 23% (95% confidence interval 19-27%, I(2)  = 84%) one to five-months after stroke; and 24% (95% confidence interval 19-29%, I(2)  = 89%) six-months or more after stroke. CONCLUSION: Anxiety after stroke occurs frequently although methodological limitations in the primary studies may limit generalizability. Given the association between prevalence rates and the Hospital Anxiety and Depression Scale-Anxiety cutoff used in studies, reported rates could in fact underrepresent the extent of the problem. Additionally, risk factors for anxiety, its impact on patient outcomes, and effects in tangent with depression remain unclear
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