p53基因cDNA突变及其蛋白高表达与大肠癌预后关系

１００份大肠癌组织，用ＲＴ－ＰＣＲ－ＳＳＣＰ检测Ｐ５３基因ＣＤＮＡ突变；ＰＡｂ１８０１单抗免疫组化检测Ｐ５３基因蛋白搞表达并对大肠癌术对后病人作５年生存随访，比较上述２结果与大肠癌预后的关系，１００例大肠癌中，ＲＴ－ＰＣＲ－ＳＳＣＰ显示５１例大肠癌Ｐ５３基因ＣＤＮＡ突变，ＰＡｂ１８０１阳性率６２％，Ｐ５３基因ＣＤＮＡ突变和Ｐ５３基因蛋白高表达与Ｄｕｋｅｓ分期无关，Ｐ５３基因ＣＤＮＡ突变与Ｐ５３基因     

Superficial- and deep-tissue temperature increases in anesthetized dogs during exposure to high specific absorption rates in a 1.5-T MR imager

Superficial- and deep-tissue heating was measured in five dogs during high-specific-absorption-rate radiofrequency (RF) irradiation to see whether significant temperature changes could be produced by a 1.5-T clinical magnetic resonance imager. The RF power output employed was 6.3 times that required for routine imaging. Temperature probes were placed in both deep and superficial tissues, and temperatures were recorded before, during, and after exposure. In each dog, there was a linear temperature increase of several degrees during RF exposure; the maximal average change was 4.6 degrees C in the urinary bladder. The temperature increase was slightly greater in deep tissues than in superficial tissues. The calculated specific absorption rate, based on the temperature change, averaged 7.9 W/kg for all five dogs. These findings argue for continued caution in the design and operation of imagers capable of high specific absorption rates, particularly when they are used for imaging infants or patients with altered thermoregulatory capability.     

Neutrophils: key mediators of tumour angiogenesis

It is now well known that most malignant tumours contain a significant amount of leucocytic infiltrates the presence of which has, on many occasions, been linked to poor patient prognosis. These leucocyte populations are recruited to tumours by chemotactic factors released by either viable or necrotic tumour cells, or by cells within the tumour stroma. In recent times, most studies have analysed the role that tumour-associated macrophages (TAM) have on tumour progression. However, there is now increasing evidence to show that neutrophils also actively participate in this process. Whilst there are some data to suggest that neutrophil-derived factors can promote genetic mutations leading to tumourigenesis, or secrete factors that promote tumour cell proliferation; there is now substantial evidence to show that neutrophils, like TAM, significantly affect tumour angiogenesis. In this review, we discuss the likely mechanisms by which neutrophils are recruited into the tumour and then elaborate on how these cells may induce tumour vascularization by the secretion of powerful pro-angiogenic factors. We also discuss possible future chemotherapeutic strategies that are aimed at limiting tumour angiogenesis by inhibiting neutrophil recruitment.     

Improved language performance subsequent to low‐frequency rTMS in patients with chronic non‐fluent aphasia post‐stroke

Background: Low‐frequency repetitive transcranial magnetic stimulation (rTMS) has emerged as a potential tool for neurorehabilitation and remediation of language in chronic non‐fluent aphasia post‐stroke. Inhibitory (1 Hz) rTMS has been applied to homologous language sites to facilitate behavioural language changes. Improvements in picture‐naming performance and speech output over time have been reported. Methods: Low‐frequency (1 Hz) rTMS was applied to six real stimulation and six sham placebo patients for 20 min per day, for 10 days, and behavioural language outcome measures were taken at baseline (pre‐stimulation) and 2 months post‐stimulation. Results: The findings demonstrate treatment‐related changes observed in the stimulation group when compared to the placebo control group at 2 months post‐stimulation on naming performance as well as other aspects of expressive language and auditory comprehension. Conclusions: These findings provide considerable evidence to support the theory of rTMS modulating mechanisms of transcallosal disinhibition in the aphasic brain and highlight the potential clinical applications for language rehabilitation post‐stroke.     

Hippocampus,delay discounting,and vicarious trial‐and‐error

In decision‐making, an immediate reward is usually preferred to a delayed reward, even if the latter is larger. We tested whether the hippocampus is necessary for this form of temporal discounting, and for vicarious trial‐and‐error at the decision point. Rats were trained on a recently developed, adjustable delay‐discounting task (Papale et al. (2012) Cogn Affect Behav Neurosci 12:513–526), which featured a choice between a small, nearly immediate reward, and a larger, delayed reward. Rats then received either hippocampus or sham lesions. Animals with hippocampus lesions adjusted the delay for the larger reward to a level similar to that of sham‐lesioned animals, suggesting a similar valuation capacity. However, the hippocampus lesion group spent significantly longer investigating the small and large rewards in the first part of the sessions, and were less sensitive to changes in the amount of reward in the large reward maze arm. Both sham‐ and hippocampus‐lesioned rats showed a greater amount of vicarious trial‐and‐error on trials in which the delay was adjusted. In a nonadjusting version of the delay discounting task, animals with hippocampus lesions showed more variability in their preference for a larger reward that was delayed by 10 s compared with sham‐lesioned animals. To verify the lesion behaviorally, rat were subsequently trained on a water maze task, and rats with hippocampus lesions were significantly impaired compared with sham‐lesioned animals. The findings on the delay discounting tasks suggest that damage to the hippocampus may impair the detection of reward magnitude. © 2014 Wiley Periodicals, Inc.     

Degradable Poly(β-amino ester) nanoparticles for cancer cytoplasmic drug delivery

Fast cytoplasmic drug delivery can overcome cancer cells' drug resistance and thus have an enhanced therapeutic efficacy. Such a drug delivery regime requires drug carriers capable of entering cancer cells, localizing and rapidly releasing the drug into endosomes/lysosomes, and subsequently disrupting their membranes to release the drug into the cytosol. We herein report a low-toxic and degradable poly(β-amino ester)-graft-polyethylene glycol (BAE-PEG) co-polymer forming pH-responsive nanoparticles capable of cytoplasmic drug delivery. BAE-PEG was synthesized by condensation polymerization of diacrylate and piperazine in the presence of a PEG-diacrylate macromonomer. BAE-PEG with 2% or 5% PEG side chains formed micelles (nanoparticles) with diameters of about 100 nm. The BAE-PEG nanoparticles were shown to rapidly enter cancer cells, localize in their endosomes/lysosomes, and subsequently disrupt them to release the drugs into the cytosol. Camptothecin loaded in the nanoparticles had a higher cytotoxicity to SKOV-3 ovarian cancer cells than free camptothecin.