292 research outputs found

    Potential Use of Folate-polyethylene glycol (PEG)-Appended Dendrimer (G3) Conjugate with alpha-Cyclodextrin as DNA Carriers to Tumor Cells

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    We previously reported that polyamidoamine STARBURST dendrimer (generation 3, G3) (dendrimer) conjugate with alpha-cyclodextrin (alpha-CyD) having an average degree of substitution of 2.4 of alpha-CyD (alpha-CDE) provided remarkable aspects as novel carriers for DNA and siRNA. To develop novel alpha-CDE derivatives with tumor cell specificity, we prepared folate-appended alpha-CDEs (Fol-alpha-CDEs) and folate-polyethylene glycol (PEG)-appended alpha-CDEs (Fol-PalphaCs) with the various degrees of substitution of folate (DSF), and evaluated in vitro and in vivo gene transfer activity, cytotoxicity, cellular association and physicochemical properties. In vitro gene transfer activity of Fol-alpha-CDEs (G3, DSF 2, 5 or 7) was lower than that of α-CDE (G3) in KB cells, folate receptor (FR)-overexpressing cancer cells. Of the three Fol-PalphaCs (G3, DSF 2, 5 or 7), Fol-PalphaC (G3, DSF 5) had the highest gene transfer activity in KB cells. The activity of Fol-PalphaC (G3, DSF 5) was significantly higher than that of alpha-CDE (G3) in KB cells, but not in A549 cells, FR-negative cells. Negligible cytotoxicity of the pDNA complex with Fol-PalphaC (G3, DSF 5) was observed in KB cells or A549 cells up to a charge ratio of 100/1 (carrier/pDNA). The cellular association of the pDNA complex with Fol-PalphaC (G3, DSF 5) could be mediated by FR on KB cells, resulting in its efficient cellular uptake. Fol-PalphaC (G3, DSF 5) had higher binding affinity with folate binding protein (FBP) than alpha-CDE (G3), although the physicochemical properties of pDNA complex with Fol-PalphaC (G3, DSF 5) were almost comparable to that with alpha-CDE (G3), although the onset charge ratio and the compaction ability of Fol-PalphaC (G3, DSF 5) were slightly different. Fol-PalphaC (G3, DSF 5) tended to show higher gene transfer activity than alpha-CDE (G3) 12 h after intratumoral administration in mice. These results suggest that Fol-PalphaC (G3, DSF 5), not Fol-alpha-CDEs, could be potentially used as a FR-overexpressing cancer cell-selective DNA carrier

    Sensitization of TRPV1 by EP(1 )and IP reveals peripheral nociceptive mechanism of prostaglandins

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    Prostaglandin E(2 )(PGE(2)) and prostaglandin I(2 )(PGI(2)) are major inflammatory mediators that play important roles in pain sensation and hyperalgesia. The role of their receptors (EP and IP, respectively) in inflammation has been well documented, although the EP receptor subtypes involved in this process and the underlying cellular mechanisms remain to be elucidated. The capsaicin receptor TRPV1 is a nonselective cation channel expressed in sensory neurons and activated by various noxious stimuli. TRPV1 has been reported to be critical for inflammatory pain mediated through PKA- and PKC-dependent pathways. PGE(2 )or PGI(2)increased or sensitized TRPV1 responses through EP(1 )or IP receptors, respectively predominantly in a PKC-dependent manner in both HEK293 cells expressing TRPV1 and mouse DRG neurons. In the presence of PGE(2 )or PGI(2), the temperature threshold for TRPV1 activation was reduced below 35°C, so that temperatures near body temperature are sufficient to activate TRPV1. A PKA-dependent pathway was also involved in the potentiation of TRPV1 through EP(4 )and IP receptors upon exposure to PGE(2 )and PGI(2), respectively. Both PGE(2)-induced thermal hyperalgesia and inflammatory nociceptive responses were diminished in TRPV1-deficient mice and EP(1)-deficient mice. IP receptor involvement was also demonstrated using TRPV1-deficient mice and IP-deficient mice. Thus, the potentiation or sensitization of TRPV1 activity through EP(1 )or IP activation might be one important mechanism underlying the peripheral nociceptive actions of PGE(2 )or PGI(2)

    Nanosurgery of sub-cellular organelles in living cells using a femtosecond laser oscillator

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    Lasers and Applications in Science and Engineering, 2006, San Jose, California, United StatesWataru Watanabe, Tomoko Shimada, Sachihiro Matsunaga, Hiroshi Ishii, Tsunehito Higashi, Kiichi Fukui, Kazuyoshi Itoh, "Nanosurgery of sub-cellular organelles in living cells using a femtosecond laser oscillator," Proc. SPIE 6108, Commercial and Biomedical Applications of Ultrafast Lasers VI, 610804 (28 February 2006); https://doi.org/10.1117/12.645474

    Intracellular disruption of mitochondria in a living HeLa cell with a 76-MHz femtosecond laser oscillator

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    Shimada T., Watanabe W., Matsunaga S., et al. Intracellular disruption of mitochondria in a living HeLa cell with a 76-MHz femtosecond laser oscillator. Optics Express, 13, 24, 9869. https://doi.org/10.1364/OPEX.13.009869

    Capsaicin May Improve Swallowing Impairment in Patients with Amyotrophic Lateral Sclerosis: A Randomized Controlled Trial

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    Patients with neurodegenerative diseases are at an increased risk of dysphagia and aspiration pneumonia. In this study, we examined whether ingestion of capsaicin prior to swallowing changes the temporal dynamics of swallowing in such patients. In a crossover, randomized controlled trial, 29 patients with neurodegenerative diseases were given a soluble wafer containing 1.5 μg capsaicin or an identical placebo 20 min prior to testing. For evaluation with video fluoroscopy (VF), patients consumed a barium-containing liquid plus thickening material. The durations of the latency, elevating and recovery periods of the hyoid were assessed from VF. Overall, no significant differences were observed in the duration of each period between capsaicin and placebo treatments. However, reductions in the latency and elevating periods were positively correlated with baseline durations. In subgroup analyses, that correlation was observed in patents with amyotrophic lateral sclerosis (ALS) but not in patients with Parkinson’s disease. The consumption of wafer paper containing capsaicin before the intake of food may be effective in patients with dysphagia related with certain neurodegenerative diseases, particularly ALS patients. Further studies will be needed to validate this finding

    Viewing Targets in Infantile Nystagmus

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    The aim of this study was to propose a new pathophysiological hypothesis for involuntary eye oscillation in infantile nystagmus (IN): patients with IN exhibit impaired gaze fixation, horizontal smooth pursuit and optokinetic nystagmus (OKN) and use saccadic eye movements for these underlying impairments. In order to induce saccades, they make enough angle between gaze and target by precedent exponential slow eye movements. IN consists of the alternate appearance of the saccade and the slow eye movements. Unlike most previous theories, IN is therefore considered a necessary strategy allowing for better vision and not an obstacle to clear vision. In five patients with IN, eye movements were analyzed during the smooth pursuit test, saccadic eye movement test, OKN test and vestibulo-ocular reflex (VOR) test. Their gaze fixation, horizontal smooth pursuit, OKN and the last half of the slow phase of VOR were impaired. The lines obtained by connection of the end eye positions of fast phase of nystagmus coincided with the trajectories of targets. The findings indicate that patients followed the target by the fast but not the slow phase of nystagmus, which supports our hypothesis. By setting the direction of slow phase of nystagmus opposite to the direction of the OKN stimulation, enough angle can be effectively made between the gaze and target for the induction of saccade. This is the mechanism of reversed OKN response. In darkness and when eyes are closed, IN weakens because there is no visual target and neither the saccade for catching up the target or slow phase for induction of the saccade is needed

    Detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT)

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    The purpose of this study was to analyze the detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT). Data for a total of 492 patients who had undergone both PET/CT and colonoscopy were analyzed. After the findings of PET/CT and colonoscopy were determined independently, the results were compared in each of the six colonic sites examined in all patients. The efficacy of PET/CT was determined using colonoscopic examination as the gold standard. In all, 270 colorectal lesions 5 mm or more in size, including 70 pathologically confirmed malignant lesions, were found in 172 patients by colonoscopy. The sensitivity and specificity of PET/CT for detecting any of the colorectal lesions were 36 and 98%, respectively. For detecting lesions 11 mm or larger, the sensitivity was increased to 85%, with the specificity remaining consistent (97%). Moreover, the sensitivity for tumors 21 mm or larger was 96% (48/50). Tumors with malignant or high-grade pathology were likely to be positive with PET/CT. A size of 10 mm or smaller [odds ratio (OR) 44.14, 95% confidence interval (95% CI) 11.44-221.67] and flat morphology (OR 7.78, 95% CI 1.79-36.25) were significant factors that were associated with false-negative cases on PET/CT. The sensitivity of PET/CT for detecting colorectal lesions is acceptable, showing size- and pathology-dependence, suggesting, for the most part, that clinically relevant lesions are detectable with PET/CT. However, when considering PET/CT for screening purposes caution must be exercised because there are cases of false-negative results
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