A 76-amino acid disulfide loop in the Yersinia pseudotuberculosis invasin protein is required for integrin receptor recognition

The Yersinia pseudotuberculosis invasin protein is a 986-amino acid protein that promotes bacterial penetration into mammalian cells by avidly binding multiple beta 1-chain integrins. A 192-amino acid carboxyl-terminal domain of invasin was previously shown to be sufficient for binding. Evidence is presented here that a 76-amino acid disulfide loop in the integrin binding domain of invasin is required for invasin-mediated cell binding and entry. Bacterial mutants that were altered at either of 2 cysteine residues in the binding domain of invasin were completely defective for entry. Purified invasin protein derivatives altered at either of these cysteines, in contrast to the wild-type invasin, did not promote either cell binding or penetration. Analysis of proteolytic products of invasin in the presence or absence of reducing agent provided evidence of an intra-chain disulfide bond near the carboxyl terminus of the protein. Alkylation of invasin derivatives with [3H]iodoacetate indicated that these 2 cysteines were normally disulfide-bonded. A treatment that resulted in the maximal reduction of the disulfide bond also resulted in maximal loss of cell attachment activity. These results indicate that the 76-amino acid disulfide loop at the carboxyl terminus of invasin is required for recognition by integrins.     

Changes in Retinal N-Acylethanolamines and their Oxylipin Derivatives During the Development of Visual Impairment in a Mouse Model for Glaucoma

Neurons are especially susceptible to oxidative damage, which is increasingly implicated in neurodegenerative disease. Certain N‐acylethanolamines (NAEs) have been shown to protect neurons from oxidative stress. Since glaucoma may be considered a neurodegenerative disorder and the survival of retinal neurons could also be influenced by N‐acylethanolamines, our goal was to quantify changes in certain N‐acylethanolamine species and their oxylipin derivatives in the retina of a mouse model for glaucoma. We also sought to identify relationships between these and parameters of glaucoma disease development, specifically intraocular pressure, visual acuity, and contrast sensitivity. Five N‐acylethanolamine species and three NAE oxylipin derivatives were quantified in retina from young and aged DBA/2Crl mice. N‐Acylethanolamines and NAE‐oxylipins in retinal extracts were quantified against deuterated standards by isotope dilution gas chromatography–mass spectrometry. Levels (nmol/g dry weight) of N‐arachidonoylethanolamine (anandamide; NAE 20:4) were significantly (p = 0.008) decreased in aged (2.875 ± 0.6702) compared to young animals (5.175 ± 0.971). Conversely, the anandamide oxylipin, 15(S)‐HETE ethanolamide (15(S)‐HETE EA), was significantly (p = 0.042) increased in aged (0.063 ± 0.009) compared to young animals (0.039 ± 0.011). Enzymatic depletion of the anandamide pool by 15‐lipoxygenase and consequent accumulation of 15(S)‐HETE ethanolamine may contribute to decreased visual function in glaucomatous mice. Since N‐acylethanolamines effectively attenuate glaucoma pathogenesis and associated visual impairment, our data provides additional rationale and novel targets for glaucoma therapies.     

In Silico/In Vitro Hit-to-Lead Methodology Yields SMYD3 Inhibitor That Eliminates Unrestrained Proliferation of Breast Carcinoma Cells

SMYD3 is a lysine methyltransferase that regulates the expression of over 80 genes and is required for the uncontrolled proliferation of most breast, colorectal, and hepatocellular carcinomas. The elimination of SMYD3 restores normal expression patterns of these genes and halts aberrant cell proliferation, making it a promising target for small molecule inhibition. In this study, we sought to establish a proof of concept for our in silico/in vitro hit-to-lead enzyme inhibitor development platform and to identify a lead small molecule candidate for SMYD3 inhibition. We used Schrodinger^® software to screen libraries of small molecules in silico and the five compounds with the greatest predicted binding affinity within the SMYD3 binding pocket were purchased and assessed in vitro in direct binding assays and in breast cancer cell lines. We have confirmed the ability of one of these inhibitors, Inhibitor-4, to restore normal rates of cell proliferation, arrest the cell cycle, and induce apoptosis in breast cancer cells without affecting wildtype cell behavior. Our results provide a proof of concept for this fast and affordable small molecule hit-to-lead methodology as well as a promising candidate small molecule SMYD3 inhibitor for the treatment of human cancer.     

Miniaturization of Electrostatic Fluid Accelerators

Existing thermal-management methods for electronics do not meet the technology needs and remain a major bottleneck in the evolution of computing, sensing, and information technology. The decreasing size of microelectronic components and the resulting increasing thermal output density require novel cooling solutions. Electrostatic fluid accelerators (EFAs), also known as electrohydrodynamic ionic wind pumps, have the potential of becoming a critical element of electronic thermal-management solutions. In order to take full advantage of EFA-based thermal management, it is essential to miniaturize EFA technology. This paper demonstrates the successful operation of a mesoscale microfabricated silicon EFA. Several cantilever structures fabricated in bulk silicon with radii of tip curvature ranging from 0.5 to 25 mum are used as the corona electrode. The device was fabricated using the combination of deep reactive ion etching (DRIE) and reactive ion etch (RIE) microfabrication processes. Forced convection cooling is demonstrated using infrared imaging, showing a 25degC surface temperature reduction over an actively heated substrate. The fabrication and test results of a mesoscale microfabricated EFA are presented in this paper.     

Effect of castration and steroid treatments on the activity of some hydrolytic enzymes in dog prostate

Adult mongrel dogs were castrated and treated by intramuscular injections of 5 alpha-androstane-3 alpha,17 beta-diol (androstanediol) alone or in combination with estradiol in order to find convenient enzymatic markers of hormone action in prostate. The activities of 15 hydrolytic enzymes were determined. Arginine esterase, acid sulfatase, and acid phosphatase were found to be the most sensitive markers of testicular hormones since they were decreased 18-, 5- and 5-fold respectively after 1 month of castration. The enzyme activities returned to precastration levels after 2 weeks of injection of androstanediol to castrated animals. The effect of androstanediol on the majority of the remaining enzymes was small. In general, the activities obtained after androstanediol treatment in combination with estradiol were similar to those obtained with androstanediol alone. Finally, beta-glucuronidase and neutral sulfatase were increased after castration, a finding that suggests that these enzymes are constituents of stromal cells. These studies will provide a basis for future studies of hormone action in the dog prostate.     

The effects of chemical injury on the ocular surface

Chemical burns of the eye may destroy all of the corneal epithelium and large portions of conjunctival epithelium into the fornices. Restoration of the ocular surface after a chemical burn depends on the centritedal movement of conjunctival epithelial cells and their adherence to the altered corneal stroma. Epithelial movement after a corneal burn is normal for 72 hours after a burn, but persistent epithelial defects thereafter commonly are not resolved until total corneal vascularization occurs. Although this fresh epithelium may be protected by a bandage soft contact lens, more promising and far-reaching approaches may follow epithelial supplementation and even replacement. The link between the health and integrity of the epithelial layer as it relates to the corneal substratum and its cellular constituents remains to be forged.     

Vulnerabilities in Anonymous Credential Systems

We show the following:

(i) In existing anonymous credential revocation systems, the revocation authority can link the transactions of any user in a subset T of users in O(log|T|) fake failed sessions.

(ii) A concern about the DLREP-I anonymous credentials system described in [Stefan Brands: Rethinking public key infrastructure and Digital Certificates; The MIT Press, Cambridge Massachusetts, London England. ISBN 0-262-02491-8] and [Stefan Brands: A Technical Overview of Digital Credentials; February 2002 (was a white paper in credentica.com)].

A Heuristic Search for Identifying Required Application Libraries Supporting a Run-Time Security Policy

On a Windows platform it is possible to inject a DLL into a running process creating a new thread of execution within an authorized process. Security tools monitoring or examining DLLs loaded into the memory space of a given process rely on policies to determine the validity of the library. Two approaches to the policy specification include “all or nothing” and “per executable” rules also referred to as a run-time security policy. Developing the run-time policy requires the running of every executable for a period of time to train the system. An alternative to the training method of the run-time approach is to determine ahead of time which DLL should be loaded before execution. A tool called LibMon was developed to monitor loading of libraries by running applications. A heuristic search algorithm was created based on the analysis of the data collected with LibMon.     

Reviews

MARK FRESKO CONSULTANCY. Sources of digital information. British Library R&D Report 6102. London: British Library Research and Development Department, 1994. No ISBN given. No price indicated. 260 pp.

CHRIS CLARE and GORDON STUTELEY. Information systems — strategy to design. London: Chapman and Hall, 1995. ISBN 0 412 576708. £16.99.

POPE, IVAN. Internet UK. Hemel Hempstead: Prentice Hall International, 294 pp. ISBN 013 190950, £19.95. SCHOFIELD, SUE. UK Internet book. Wokingham: Addison‐Wesley, 301 pp. ISBN 0201 42766 4, £19.95.

RIMMER, STEVE. Planet Internet. New York: Windcrest, 1995. ISBN 0 8306 24724. £22.95 (pbk).

JILL H. ELLSWORTH and MATTHEW V. ELLSWORTH. The Internet business book. London: John Wiley & Sons, 1994. $22.95, 376pp. ISBN 0 471058092.

JOHN S. QUARTERMAN and SMOOT CARL‐MITCHELL. The e‐mail companion: communicate effectively via the Internet and other global networks. Addison‐Wesley, 1994. 318 pp. ISBN 0 201 40658 6. $19.95.

McCLURE, C.R., MOEN, W.E. and RYAN, J. Libraries and the Internet/NREN: perspectives, issues and challenges. London: Mecklermedia 1994. $35.00. ISBN 0 89736 824 7. McCLURE, C.R., BERTOT, J.C., and ZWEIZIG, D.L. Public libraries and the Internet: study results, policy issues and recommendations. Washington: National Commission on Libraries and Information Science, 1994. No price or ISBN given.

FRANCES BLOMELEY. Networks and network services: a user's guide. Immediate Publishing, 1994. ISBN 1–89831–00–03. 246 pp. £14.95.

NEIL SMITH (ed) ibraries, networks and Europe: a European networking study. British Library Research and Development Department, 1994. (LIR Series 101) 91 pp. ISBN 0 7123 3295 2. £25. (Distributed by Turpin Distribution Services Ltd, Blackhorse Road, Letchworth, Herts. SG6 1HN).

ALAN BRYANT. Creating successful bulletin board systems. Addison‐Wesley, 1994. ISBN 0–201–62668–3. $39.95.

Directory of electronic journals, newsletters and academic discussion lists. 4th ed. Compiled by Lisabeth A. King and Diane Kovacs, edited by Ann Okerson. Washington, DC: Association of Research Libraries, 1994. 575 pp. ISSN 1057–1337. $54 (paperback), $33 (ARL members).

THE BRITISH LIBRARY and ELECTRONIC PUBLISHING SERVICES LTD. Electronic publishing practice in the UK: LIR Report 95. University Press, Cambridge, 1994. 185 pp. ISBN 0 7123 3280 4. £30.00. (Distributed by Turpin Distribution Services, Blackhorse Road, Letchworth S96 1HN).

INTERNET WORLD'S On Internet 94: an international guide to electronic journals, newsletters, texts, discussion lists, and other resources on the Internet. edited by Tony Abbott with a Preface by Daniel P. Dem. Westport, London: Mecklermedia, 1994. £29.50 $45.00. ISBN 0–88736–929–4.

S. BANG. The Internet unleashed. Indianapolis: SAMS Publishing, 1994. $44.95. ISBN 0 672 30466 X.

GAIL K. DICKINSON, Selection and evaluation of electronic resources. Libraries Unlimited, 1994. ISBN 1 56308 098 2. £22.50.