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Podophyllotoxin (PPT) exhibited significant activity against P-glycoprotein mediated multidrug resistant (MDR) tumor cell lines; however, due to its poor solubility and high toxicity, PPT cannot be dosed systemically, preventing its clinical use for MDR cancer. We developed a nanoparticle dosage form of PPT by covalently conjugating PPT and polyethylene glycol (PEG) with acetylated carboxymethyl cellulose (CMC-Ac) using one-pot esterification chemistry. The polymer conjugates self-assembled into nanoparticles (NPs) of variable sizes (20–120 nm) depending on the PPT-to-PEG molar ratio (2–20). The conjugate with a low PPT/PEG molar ratio of 2 yielded NPs with a mean diameter of 20 nm and released PPT at ∼5%/day in serum, while conjugates with increased PPT/PEG ratios (5 and 20) produced bigger particles (30 nm and 120 nm respectively) that displayed slower drug release (∼2.5%/day and ∼1%/day respectively). The 20 nm particles exhibited 2- to 5-fold enhanced cell killing potency and 5- to 20-fold increased tumor delivery compared to the larger NPs. The biodistribution of the 20 nm PPT-NPs was highly selective to the tumor with 8-fold higher accumulation than all other examined tissues, while the larger PPT-NPs (30 and 120 nm) exhibited increased liver uptake. Within the tumor, >90% of the 20 nm PPT-NPs penetrated to the hypovascular core, while the larger particles were largely restricted in the hypervascular periphery. The 20 nm PPT-NPs displayed significantly improved efficacy against MDR tumors in mice compared to the larger PPT-NPs, native PPT and the standard taxane chemotherapies, with minimal toxicity.  相似文献   
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Normal aging is associated with cognitive decline and underlying brain dysfunction. Previous studies concentrated less on brain network changes at a systems level. Our goal was to examine these age-related changes of fMRI-derived activation with a common network parcellation of the human brain function, offering a systems-neuroscience perspective of healthy aging. We conducted a series of meta-analyses on a total of 114 studies that included 2035 older adults and 1845 young adults. Voxels showing significant age-related changes in activation were then overlaid onto seven commonly referenced neuronal networks. Older adults present moderate cognitive decline in behavioral performance during fMRI scanning, and hypo-activate the visual network and hyper-activate both the frontoparietal control and default mode networks. The degree of increased activation in frontoparietal network was associated with behavioral performance in older adults. Age-related changes in activation present different network patterns across cognitive domains. The systems neuroscience approach used here may be useful for elucidating the underlying network mechanisms of various brain plasticity processes during healthy aging.  相似文献   
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Neural crest stem cells (NCSCs), a population of multipotent cells that migrate extensively and give rise to diverse derivatives, including peripheral and enteric neurons and glia, craniofacial cartilage and bone, melanocytes and smooth muscle, have great potential for regenerative medicine. Non-human primates provide optimal models for the development of stem cell therapies. Here, we describe the first derivation of NCSCs from cynomolgus monkey embryonic stem cells (CmESCs) at the neural rosette stage. CmESC-derived neurospheres replated on polyornithine/laminin-coated dishes migrated onto the substrate and showed characteristic expression of NCSC markers, including Sox10, AP2α, Slug, Nestin, p75, and HNK1. CmNCSCs were capable of propagating in an undifferentiated state in vitro as adherent or suspension cultures, and could be subsequently induced to differentiate towards peripheral nervous system lineages (peripheral sympathetic neurons, sensory neurons, and Schwann cells) and mesenchymal lineages (osteoblasts, adipocytes, chondrocytes, and smooth muscle cells). CmNCSCs transplanted into developing chick embryos or fetal brains of cynomolgus macaques survived, migrated, and differentiated into progeny consistent with a neural crest identity. Our studies demonstrate that CmNCSCs offer a new tool for investigating neural crest development and neural crest-associated human disease and suggest that this non-human primate model may facilitate tissue engineering and regenerative medicine efforts.  相似文献   
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ObjectivesTo assess consumption of dietary and herbal supplements (DHS) among patients in internal medicine departments and determine whether such use is documented in their medical files.Methods267 patients from three internal medicine departments of an academic medical center in Haifa, Israel were assessed prospectively with questionnaires about their DHS use in the month preceding hospitalization. DHS were categorized into vitamins & minerals, herbal supplements and others. Further data was then collected from patients' medical records on socio-demographic and medical characteristics, as well as documentation of DHS use.Results123 patients (50.6 %) used DHS on a daily basis. Most of them (53.7 %) were using more than one DHS. DHS use was more prevalent in older (OR = 1.02 [1.001–1.036], p = 0.034) and educated (OR = 0.482 [0.252-0.923], p = 0.028) patients. Vitamins & minerals were used mainly to enhance vitality and address laboratory abnormalities, whereas herbal supplements were used mainly for gastrointestinal problems (p < 0.001). DHS use was reported to the physicians by 42 % of the patients, mostly at the patients’ initiative [92 (82.1 %), p < 0.001)]. Vitamins and minerals were the most reported category of DHS (94 (57.3 %), p < 0.001). The use of DHS was reported to physicians for 112 DHS (41.8 %) but only 32 DHS (11.9 %) were documented in their medical files. The documentation of vitamins and minerals was significantly higher compared to herbal supplements documentation (29 (17.7 %) & 3 (2.9 %) respectively, P < 0.001).ConclusionsDHS are commonly used by patients hospitalized in the internal medicine departments. Many patients do not report such use to the physicians, and more strikingly, physicians do not document DHS use in patient medical files. This communication gap may have serious medico-legal ramifications due to DHS side effects and DHS interactions with other DHS and with conventional drugs.  相似文献   
78.
This study aimed to identify different trajectories of adherence to home rehabilitation for older adults with hip fracture and cognitive impairment, to examine associations between different adherence trajectories and postoperative recovery outcomes, and to explore the predictors of adherence trajectories. Group-based trajectory modeling showed two adherence trajectories: low (39.06%) and high (60.94%) adherence. The high adherence group had better activities of daily living (β=11.77, p<.001), instrumental activities of daily living (β=0.56, p<.01), femoral muscular strength (β=3.35, p<.01) on the fractured side and quality of life (β=-0.81, p=.02) than the low adherence group. Participants who established exercise habits (OR=6.49, p<.01) and consulted a physical therapist (OR=4.29, p=.03) during hospitalization were more likely to be in the high adherence group.  相似文献   
79.
Research questionThe cost of IVF treatment remains high, among other factors because of the medication needed for ovarian stimulation. This study investigated the effect of using low-dose human chorionic gonadotrophin (HCG) for the second phase of follicular maturation after corifollitropin alfa induction, to replace the more expensive, either recombinant or human menopausal gonadotrophin (HMG), on the cost of ovarian stimulation.DesignOne hundred and five patients were randomly divided into two groups: patients in the HCG group (n = 50) received low-dose HCG from Day 7 until the diameter of at least three follicles reached 17 mm or more, while patients in the FSH group (n = 55) received conventional ovarian stimulation with highly purified HMG injections.ResultsThe clinical pregnancy rate in the HCG group was 38% higher than in the FSH group (number needed to treat, NNT = 13). The cost per pregnancy needed for ovarian stimulation was reduced from €4902 in the FSH group to €2684 in the HCG group. Hence, the cost of ovarian stimulation medication to obtain 10 pregnancies using the conventional FSH protocol is sufficient to attain 18 pregnancies when applying the low-dose HCG protocol.ConclusionThis study provides evidence that using HCG instead of HMG/FSH for ovarian stimulation results in a significant reduction in the cost of IVF with, at least, an equivalent pregnancy rate.  相似文献   
80.
The study aimed to assess the effect of exogenous factors such as surgeon posture, surgical instrument length, fatigue after a night shift, exercise and caffeine consumption on the spatial accuracy of neurosurgical manipulations. For the evaluation and simulation of neurosurgical manipulations, a testing device developed by the authors was used. The experimental results were compared using nonparametric analysis (Wilcoxon test) and multivariate analysis, which was performed using mixed models. The results were considered statistically significant at p < 0.05. The study included 11 first-year neurosurgery residents who met the inclusion criteria. Hand support in the sitting position (Wilcoxon test p value = 0.0033), caffeine consumption (p = 0.0058) and the length of the microsurgical instrument (p = 0.0032) had statistically significant influences on the spatial accuracy of surgical manipulations (univariate analysis). The spatial accuracy did not significantly depend on the type of standing position (Wilcoxon test p value = 0.2860), whether the surgeon was standing/sitting (p = 0.1029), fatigue following a night shift (p = 0.3281), or physical exertion prior to surgery (p = 0.2845).When conducting the multivariate analysis, the spatial accuracy significantly depended on the test subject (p < 0.0001), the use of support during the test (p = 0.0001), and the length of the microsurgical instrument (p = 0.0397). To increase the spatial accuracy of microsurgical manipulations, hand support and shorter tools should be used. Caffeine consumption in high doses should also be avoided prior to surgery.  相似文献   
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