WAF1/p21 regulates proliferation, but does not mediate p53-dependent apoptosis in urothelial carcinoma cell lines

The WAF1/p21 gene product is an inhibitor of cyclin-dependent kinases which can be induced by the tumor suppressor p53 and mediate some of its effects, or function in p53-independent pathways of cell cycle regulation. Although a potential tumor suppressor gene, WAF1/p21 is expressed in bladder cancer. To elucidate the function of p21 in tumor cells we have investigated in urothelial carcinoma cell lines: i) WAF1/p21 mRNA and protein expression, ii) the biological effects of p21 overexpression or down-regulation and (iii) whether p21 can be induced by p53. WAF1/p21 mRNA levels examined in four cell lines were comparable to bladder mucosa. One cell line, HT1376, failed to express p21 protein due to a frame shift mutation. Overexpression of WAF1/p21 cDNA inhibited clone formation in three cell lines, whereas transfection with antisense WAF1 increased clone sizes and numbers. WAF1 sense clones showed diminished cell proliferation compared to the parental cell line. Apoptosis- induced wild-type p53 was not inhibited by overexpression of antisense WAF1/p21. In a cell clone derived from line VMCub1 by stable transfection with wild-type p53 under the control of a metallothionein promotor, p21 was induced along with p53 upon activation of the promoter with zinc chloride. This induction was accompanied by a decrease in cell proliferation but by little apoptosis. These data suggest that p21 inhibits proliferation in a p53-dependent or independent manner but does not mediate p53-induced apoptosis in urothelial carcinoma cells.     

Variations in morphology and composition of barley endosperm cell walls

BACKGROUND: The endosperm cell walls (CWs) impact upon barley grain utilization as well as influence animal and human nutrition. The objective of this study was to examine the morphological and compositional differences in the endosperm CWs derived from barley grain grown in different (uncontrolled) environments in Canada, and differing in grain hardness, protein, and total β‐glucan contents. RESULTS: The endosperm CWs were isolated from barley, cv. Metcalfe, grown in Davidson, SK (sample A), Hythe, AB (sample B), and Hamiota, MB (sample C). The inner wall surfaces of sample A exhibited deep indentations made by large and small starch granules, whereas the CWs of sample B were thicker, had smooth surface, and exhibited a greater degree of binding between the adjoining cells. The CWs of sample A contained the lowest amount of β‐glucans but the highest amount of arabinoxylans and the mannose‐containing (glucomannans) polysaccharides. The CWs of sample B contained the highest ratio of ferulic and dehydrodiferulate residues to Xyl residues among the samples, indicating the greatest potential and degree of cross‐linking of arabinoxylans in these preparations which might be related to the strength and rigidity of the grain endosperm. The amino acid composition of the proteins detected in the isolated CW indicated the presence of 37–47 g kg^?1 of structural proteins. CONCLUSIONS: Substantial differences in the morphological appearance and chemical composition of the CW preparations were observed and some attempts were made to relate these differences to the variable composition and physical properties of barley grain as affected by the environmental factors. Copyright © 2008 Crown in the Right of Canada, Canadian Grain Commission. Published by John Wiley and Sons, Ltd     

Emulsifying and foaming properties of Phaseolus vulgaris and coccineus proteins

Protein isolates from two Phaseolus cultivars, common bean (Phaseolus vulgaris L.) and scarlet runner bean (Phaseolus coccineus L.), were prepared by wet extraction methods (isoelectric precipitation – 4000 rpm, ultrafiltration, extraction with NaCl 2%, and isoelectric precipitation – 9900 rpm). The protein isolates were characterized by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and then evaluated for their solubility. The emulsion stability of emulsions produced at pH 7.0 and 5.5 with 1% or 2% or 3% w/v protein isolate was evaluated by average droplet size diameter, viscosity and creaming measurements. Emulsions with 1% protein content were unstable through storage. Emulsions with 3% w/v protein isolate concentration, extracted by ultrafiltration at pH 5.5 from both cultivars, were flocculated; this was more pronounced for coccineus isolates. The foaming properties, for the respective foams, were investigated. Foams with 1% w/v protein showed little foaming ability Ultrafiltration isolates produced more foam, which was especially stable at pH 5.5.     

Lack of depression-like effects of saccharin deprivation in rats: Forced swim test, differential reinforcement of low rates and intracranial self-stimulation procedures.

In humans and laboratory animals, drug withdrawal often is associated with depression-like behaviors. In the present study, rats had unlimited free-choice access to water and a saccharin-containing solution before being subjected to repeated episodes of saccharin deprivation. Saccharin deprivation (1) reduced immobility time in the forced swim test, (2) increased reinforcement rate in rats trained to lever-press under the differential reinforcement of a low-rate (72-sec) schedule of food reinforcement, and (3) lowered intracranial self-stimulation thresholds in a discrete-trial current titration procedure. Taken together, these findings suggest that deprivation from a nondrug reinforcer, saccharin, is not associated with depression-like behaviors. In contrast, saccharin-deprived rats demonstrated improved performance in the behavioral paradigms used here. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Etude de la reaction d'oxydo-réduction de l'aluminium dans des bains de chlorures alcalins fondus

Résumé Dans le présent travail nous étudions la réaction d'oxydo-réduction de l'aluminium dans l'eutectique fondu NaCl–KCl–LiCl à 723 K en se penchant plus particulièrement sur le problème de la détermination de la valeur du nombre,n, d'électrons échangés au cours de cette réaction. Deux types d'expériences sont réalisées, tout d'abord des déterminations de l'activité des ions aluminium par mesure de fém, puis des mesures de cinétique à l'aide de la méthode chronopotentiométrique sur une électrode d'argent. Nous avons constaté que l'analyse des courbes provenant de ces méthodes nécessite la connaissance des coefficients d'activité ainsi que la variation du coefficient de diffusion, en fonction de temps pour en déduire une valeur den. La prise en compte de ces paramètres au cours de l'analyse des chronopotentiogrammes obtenus, conduit à des valeurs den voisines de 3 conformément à la réaction d'oxydo-réduction de l'aluminium.

---

A study of the redox reaction of aluminium in a NaCl–KCl–LiCl melt at 723 K has been carried out with particular emphasis on the problem of determination of the number of electrons,n, exchanged during this reaction. Two types of experiments were performed, initially the determination of the aluminium ion activity by e.m.f. measurement and, secondly, investigation of the reaction kinetics using chronopotentiometry on a silver electrode. For analysis of the curves resulting from this method, a knowledge of the activity coefficients and of the variation of the diffusion coefficient with time is needed in order to derive a value forn. Taking into account these parameters, a value ofn approximately equal to 3 was obtained for the aluminium redox reaction.

     

Molecular Toxicology of Substances Released from Resin�CBased Dental Restorative Materials

Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites’ molecular toxicology and to give implications for possible improvements concerning their biocompatibility.     

A comprehensive review of the implementation of hazard analysis critical control point (HACCP) to the production of flour and flour-based products

The production of flour and semolina and their ensuing products, such as bread, cake, spaghetti, noodles, and corn flakes, is of major importance, because these products constitute some of the main ingredients of the human diet. The Hazard Analysis Critical Control Point (HACCP) system aims at ensuring the safety of these products. HACCP has been implemented within the frame of this study on various products of both Asian and European origin; the hazards, critical control limits (CCLs), observation practices, and corrective actions have been summarized in comprehensive tables. Furthermore, the various production steps, packaging included, were thoroughly analyzed, and reference was made to both the traditional and new methodologies in an attempt to pinpoint the occurring differences (advantages and disadvantages) per process.     

ROC analysis of ultrasound tissue characterization classifiers for breast cancer diagnosis

Breast cancer diagnosis through ultrasound tissue characterization was studied using receiver operating characteristic (ROC) analysis of combinations of acoustic features, patient age, and radiological findings. A feature fusion method was devised that operates even if only partial diagnostic data are available. The ROC methodology uses ordinal dominance theory and bootstrap resampling to evaluate A(z) and confidence intervals in simple as well as paired data analyses. The combined diagnostic feature had an A(z) of 0.96 with a confidence interval of at a significance level of 0.05. The combined features show statistically significant improvement over prebiopsy radiological findings. These results indicate that ultrasound tissue characterization, in combination with patient record and clinical findings, may greatly reduce the need to perform biopsies of benign breast lesions.     

Differences in susceptibility to Mannheimia haemolytica-associated mastitis between two breeds of dairy sheep

We used a Mannheimia haemolytica isolate to study differences in susceptibility to experimental mastitis between two breeds of dairy sheep. The isolate was deposited into the teat duct of Karagouniko (K, n=8) or Frisarta (F, n=8) ewes. The animals were monitored by means of clinical, bacteriological, cytological and pathological methods. K ewes did not develop any systemic or mammary clinical signs, whilst F ewes became ill and developed acute clinical mastitis 12 h later (P<0.001). Bacteria were isolated from 34/48 samples from K ewes and from 46/46 samples from F ewes. Positive California mastitis test (CMT) results were 17/24 samples from K ewes and 23/23 samples from F ewes; leucocytes were seen in Giemsa-stained films. Total pathology score summed over all group K ewes was 41 (maximum possible: 128); Man. haemolytica was isolated from 12/24 tissue samples. Total pathology score summed over all group F ewes was 93; Man. haemolytica was isolated from 24/24 tissue samples. Hyperplastic lymphoid nodules consisting of lymphocytes and plasma cells with germinal activity were characteristically present at the border between teat duct-teat cistern of group K ewes; no such structures were observed in teats of group F ewes. The results identified differences in susceptibility/resistance to a mastitis pathogen among animals of the two breeds. Defence mechanisms of the teat appeared to be inadequate against the invading organisms; as lymphoid nodules have been considered important defensive mechanisms of the ovine teat, their observed lack in Frisarta ewes might have predisposed them to development of mastitis.