A branched histidine/lysine peptide, H2K4b, in complex with plasmids encoding antitumor proteins inhibits tumor xenografts

BACKGROUND: In this study we investigated whether a particular branched HK polymer, H2K4b, was an effective in vivo carrier of plasmids expressing the antiangiogenic kringle 1-5 or the tumor suppressor p53. METHODS: H2K4b was synthesized on a solid-phase peptide synthesizer. Distribution, optimization and time course studies were done in tumor-bearing nude mice by systemically administering H2K4b in complex with a luciferase-expressing plasmid. We examined the amount of tumor angiogenesis in C6 with MDA-MB-435 xenografts utilizing the carmine dye. The ability of H2K4b to carry luciferase plasmids to different tissues was compared with several liposomal carriers. Medium from cells transfected with mKr1-5 was tested for its capacity to inhibit angiogenesis with an in vivo Matrigel assay. We then determined if systemically delivered H2K4b in complex with plasmid encoding mKr1-5 inhibited tumor growth; we also compared the antitumor activity of HK polyplexes containing hKr1-5, mKr1-5, and p53 plasmids. RESULTS: H2K4b carried the luciferase-expressing plasmid in order of descending efficacy to these tissues: lung, spleen, tumor, and liver. Compared to DOTAP-containing liposomes, H2K4b was a more effective carrier of a luciferase-containing plasmid to extrapulmonary tissues. We then determined that mKr1-5 in complex with H2K4b reduced MDA-MB-435 tumor growth by approximately 50% compared to the control group (P < 0.01). Similarly, H2K4b/mKr1-5 polyplexes reduced the growth of C6 xenografts. In MDA-MB-435 xenografts, p53- and Kr1-5-expressing plasmids in complex with H2K4b had comparable antitumor activity. CONCLUSION: H2K4b demonstrates potential as a carrier of plasmids encoding antiangiogenic and/or tumor suppressor proteins in a tumor-bearing mouse model.     

Effects of prefrontal ablations on the reaction of the active choice of feeder under different probability and value of the reinforcement on dog

The role of the prefrontal cortex was investigated on the reaction of the active choice of the two feeders under changes value and probability reinforcement. The experiments were performed on 2 dogs with prefrontal ablation (g. proreus). Before the lesions the dogs were taught to receive food in two different feeders to conditioned stimuli with equally probable alimentary reinforcement. After ablation in the inter-trial intervals the dogs were running from the one feeder to another. In the answer to conditioned stimuli for many times the dogs choose the same feeder. The disturbance of the behavior after some times completely restored. In the experiments with competition of probability events and values of reinforcement the dogs chose the feeder with low-probability but better quality of reinforcement. In the experiments with equal value but different probability the intact dogs chose the feeder with higher probability. In our experiments the dogs with prefrontal lesions chose the each feeder equiprobably. Thus in condition of free behavior one of different functions of the prefrontal cortex is the reactions choose with more probability of reinforcement.     

Spectral luminescence studies of cells stained with acrichine derivatives

Excitation and fluorescence spectra are given of quinacrine derivative solutions, of buccal epithelium cell nuclei, of peripheral blood cells, and of isolated chromosomes treated with propyl-quinacrine mustard. It is confirmed that the differential cell treatment with quinacrine derivates may be observed in aqueous solutions only. Data obtained allow us to give some recommendations for employment of optimal filters and dichroic beam-splitters in the fluorescence microscopy of chromosomes treated with quinacrine derivatives.     

Deficit of learning of posture voluntary control in patients with cortical lesions of various locations: cortical mechanisms of posture regulation

Forty two hemiparetic patients after cerebrovascular accidents were trained to change the position of the center of pressure according to a target on the screen with the visual feedback control. The learning was substantially impaired in comparison with the group of healthy subjects. Patients with the right-hemispheric lesions showed somewhat greater learning deficit than patients with lesions in the left hemisphere. Lesion localization also affected the process of learning. The learning was disturbed to a greater extent in patients with lesions involving not only motor but also premotor and parietal cortical areas. In patients with parieto-temporal lesions the learning reached a very low level after three initial days of training, possibly, because of the deficit of sensory integration and of body scheme in the extra-personal space. Patients with combined lesions of the motor, premotor, and parietal areas showed the lowest results. The learning was shown to depend on the deficit of proprioception and extent of postural disturbances (asymmetry of body weight distribution and amplitude of the center of pressure oscillations) rather than on the extent of motor deficit (paresis and spasticity). However, the learning itself improved some motor disturbances.     

Repeat cervical cytology at the time of colposcopy. Is there an added benefit?

OBJECTIVE: To determine if repeating the Pap smear (PS) at colposcopy offers added benefit in the detection of cervical squamous intraepithelial lesions (SILs). STUDY DESIGN: Eight hundred fifty-two women were subjects of this study. Patients with cervical SIL were defined as women with SIL on the repeat PS, or SIL on the colposcopic cervical biopsy (bx) or a negative repeat PS and bx but confirmed SIL on both the previous and follow-up PS or bx. The sensitivities of repeat PS and bx in detecting SIL were calculated. The chi 2 test was used to assess statistical significance. The total cost of repeating the PS was calculated by multiplying the total number of patients (852) by the estimated cost of a single PS ($25). RESULTS: The sensitivities of repeat PS, bx and PS/bx combined were .89, .69 and .92 for low grade SIL (LSIL) and .74, .77 and .98 for high grade SIL (HSIL), respectively (P < .0001). Sixteen percent of the HSIL and 28% of the LSIL cases were diagnosed on repeat PS only (negative bx). If repeat PS was omitted, $21,300 would have been saved.     

A specific function of the motor cortex in the reorganization of coordination in motor learning in animals and humans

The findings suggest that a particular function of MCx in motor learning involves suppression of synergies and co-ordination which interferes with acquisition of new motor patterns. Experimental animal models based on inhibition of certain natural synergies or reflexes in the process of learning new co-ordination have been developed where the MCx is responsible for inhibition of natural motor patterns. Following the MCx lesion the natural synergies dominate again and the learned movement cannot be adequately performed. Similar disturbances occur after combined lesions of the premotor and parietal associative cortex or after lesions of the cerebellar nuclei. However, after the associative cortex or cerebellar lesions the recovery of learned co-ordinations is possible. This suggests the inhibition of inappropriate synergies or co-ordination during motor learning is a specific function of the MCx, the latter taking part in organisation of new co-ordination between posture and movement in humans as well.     

Human muscle stem cells are refractory to aging

Age‐related loss of muscle mass and strength is widely attributed to limitation in the capacity of muscle resident satellite cells to perform their myogenic function. This idea contains two notions that have not been comprehensively evaluated by experiment. First, it entails the idea that we damage and lose substantial amounts of muscle in the course of our normal daily activities. Second, it suggests that mechanisms of muscle repair are in some way exhausted, thus limiting muscle regeneration. A third potential option is that the aged environment becomes inimical to the conduct of muscle regeneration. In the present study, we used our established model of human muscle xenografting to test whether muscle samples taken from cadavers, of a range of ages, maintained their myogenic potential after being transplanted into immunodeficient mice. We find no measurable difference in regeneration across the range of ages investigated up to 78 years of age. Moreover, we report that satellite cells maintained their myogenic capacity even when muscles were grafted 11 days postmortem in our model. We conclude that the loss of muscle mass with increasing age is not attributable to any intrinsic loss of myogenicity and is most likely a reflection of progressive and detrimental changes in the muscle microenvironment such as to disfavor the myogenic function of these cells.