No abstract available

No abstract available

[en] Protein Phosphatase 2A (PP2A) is a major serine/threonine phosphatase in cells. It consists of a catalytic subunit (C), a structural subunit (A), and a regulatory/variable B-type subunit. PP2A has a critical role to play in homeostasis where its predominant function is as a phosphatase that regulates the major cell signaling pathways in cells. Changes in the assembly, activity and substrate specificity of the PP2A holoenzyme have a direct role in disease and are a major contributor to the maintenance of the transformed phenotype in cancer. We have learned a lot about how PP2A functions from specific mutations that disrupt the core assembly of PP2A and from viral proteins that target PP2A and inhibit its effect as a phosphatase. This prompted various studies revealing that restoration of PP2A activity benefits some cancer patients. However, our understanding of the mechanism of action of this is limited because of the complex nature of PP2A holoenzyme assembly and because it acts through a wide variety of signaling pathways. Information on PP2A is also conflicting as there are situations whereby inactivation of PP2A induces apoptosis in many cancer cells. In this review we discuss this relationship and we also address many of the pertinent and topical questions that relate to novel therapeutic strategies aimed at altering PP2A activity

[en] How cells move through the three-dimensional extracellular matrix (ECM) is of increasing interest in attempts to understand important biological processes such as cancer metastasis. Just as in motion on flat surfaces, it is expected that experimental measurements of cell-generated forces will provide valuable information for uncovering the mechanisms of cell migration. However, the recovery of forces in fibrous biopolymer networks may suffer from large errors. Here, within the framework of lattice-based models, we explore possible issues in force recovery by solving the inverse problem: how can one determine the forces cells exert to their surroundings from the deformation of the ECM? Our results indicate that irregular cell traction patterns, the uncertainty of local fiber stiffness, the non-affine nature of ECM deformations and inadequate knowledge of network topology will all prevent the precise force determination. At the end, we discuss possible ways of overcoming these difficulties. (paper)

[en] The values for α/β (fractionation sensitivity, or recovery capacity) for early and late reactions in human normal tissues are consistent with results from experimental animals. For breast treatments direct analysis indicates that for early reactions α/β is in the range 7 to 11 Gy, while for late effects it is the range 2 to 4 Gy. Data on recovery kinetics in human tissues is limited but these indicate that recovery may be slower in humans than in rodents. For early skin reactions the halftime of recovery is about 1 h, while for late telangiectasia it is more than 3 h. α/β values for human tumors are more variable than in rodents: some are high (head and neck, lung, skin, cervix) and similar to those for early reacting normal tissues. Others are low, icluding melanomas, where α/β was estimated at 0.6 (-1.1, 2.5) Gy, and liposarcomas, where direct analysis of cases surveyed from the literature suggested that α/β=0.4 (-1.4, 5.4 Gy). Repopulation kinetics is faster in the mucosa of the soft palate and faucial pillars (1.8 Gy/day) than in head and neck tumors (up to 1 Gy/day). (author). 78 refs.; 2 figs.; 2 tabs

[en] Post-traumatic joint contracture induced by scar tissues following a surgery or injury can leave patients in a permanent state of pain and disability, which is difficult to resolve by current treatments. This randomized controlled trial examines the therapeutic effect of pulsed high-intensity laser (PHIL) and pulsed high-intensity focused ultrasound (PHIFU) for post-traumatic joint contracture due to arthrofibrosis. The peak power levels of both PHIL and PHIFU are much higher than that of laser or ultrasound currently used in physical therapy, while short pulses are utilized to prevent damage. To test the effectiveness of these treatments, a rabbit knee model for joint contracture was established. Twenty-one rabbits were split into four groups: untreated control (n  =  5), PHIL (n  =  5), PHIFU (n  =  5), and a PHIL  +  PHIFU group (n  =  6). Maximum extension of the surgically modified rabbit knee was compared to that of the contralateral control knee over the course of 16 weeks. The rabbits in the untreated control group maintained a relatively consistent level of joint contracture, while every rabbit in each of the treatment groups had improved range of motion, eventually leading to a restoration of normal joint extension. Average recovery time was 7.6  ±  1.5 weeks for the PHIL treatment group, 9.8  ±  3.7 weeks for the PHIFU group, and 8.0  ±  2.2 weeks for the combined treatment group. Histopathology demonstrated reduced density and accelerated resorption of scar tissues in the treated knee joints. This study provides evidence that both PHIL and PHIFU are effective in treating post-traumatic joint contracture in rabbits and warrant further investigation into the underlying mechanisms to optimize PHIL and PHIFU based treatments in a larger number of animals. (paper)

[en] In this study, one of the two sections of Cizre-Mardin Ulucami door is investigated by x-ray radiography technique whether it has some patterns similar to those which were discovered during the restoration of the first section of the door. Some painted and traced parts have been fixed and torn down, cleared and investigated. In the study, many pieces of the first part of the door including the second door have been investigated by x-ray radiography technique and have been evaluated. Furthermore, neutrography has been applied on some painted parts for the investigation of traces of painting. (author)

[en] Objective: To evaluate the clinical results of three dimensional conformal radiotherapy (3DCRT) for esophageal carcinoma. Methods: From May 1999 to May 2001, 104 patients with pathologically confirmed esophageal carcinoma were randomly divided into conventional radiotherapy (CT) and three dimensional conformal radiotherapy(3DCRT) groups, with 52 patients in each arm. The patients in CT group received conventional radiotherapy in 2.0 Gy/f, 5 fractions a week to a total dose of 70 Gy in 7 weeks. The patients in 3DCRT group were first treated by the same fractionation in CT group to the dose of 40 Gy, and then treated by 3DCRT in 3.0 Gy/f, 5 fractions a week to the total dose of 70 Gy in 6 weeks. Results: The 1- and 3-year local control rates were 80.2% and 60.5% in 3DCRT group and 61.6% and 31.7% in CT group(χ²=4.87, P<0.05). The 1- and 3-year survival rates were 72.4% and 53.4% in 3DCRT group and 51.5% and 27.8% in CT group (χ²=4.19, P<0.05). Between the two groups, there was no significant difference in radiation toxicities. Conclusions: The 1- and 3-year local control rate and survival rate of patients with esophageal carcinoma treated by three dimensional conformal radiotherapy is superior to conventional radiotherapy. However, longer-term results need further study which involves more patients and prolonged follow-up. (authors)

[en] The bioremediation of nickel pollution of the mixed metal solution containing lead, nickel and chromium has been studied by using the natural biomass of Oedogonium sp. The effect of various concentrations of the biomass show that the maximum biosorption of Nickel from the mixed metal solution occurred at 3.5g, when the concentration of Nickel pollutant was 50 ppm in a 100 ml of the mixed metal solution. The biosorption of Nickel from single metal solution show that biosorption of lead and chromium do not interfere with the biosorption of Nickel by Oedogonium sp. (author)

[en] In experiments in which liquid holding recovery (LHR) was measured, the majority of cellular population is formed by non-viable cells and cell multiplication may be important for LHR expression. In order to distinguish between recuperation of viability (true LHR) and cell multiplication, it was necessary to employ improved plating techniques and a fluctuation test based on Poisson distribution. Our results are an indication that this fluctuation test, used together with the traditional method, is a good tool to distinguish repair from cell multiplication. (author)