Clinical services and demographic characteristics of police psychologists.

Surveyed 56 police psychologists to ascertain their demographic characteristics and the nature of the services that they provide for law enforcement organizations. Ss identified themselves as either staff (n?=?33) or consulting (n?=?23) psychologists. Selected results show that the modal respondent had a doctoral degree in clinical or counseling psychology and provided a wide variety of clinical services. Daily consulting fees varied widely, but the full-time salaries of staff psychologists were comparable with those reported by psychologists in other clinical settings. The staff psychologist's most common service was providing therapy, whereas the consultant's greatest allotment of time was devoted to assessment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative detection of protein arrays

We introduce a quantitative method that utilizes scanning electron microscopy for the analysis of protein chips (SEMPC). SEMPC is based upon counting target-coated gold particles interacting specifically with ligands or proteins arrayed on a derivative microscope glass slide by utilizing backscattering electron detection. As model systems, we quantified the interactions of biotin and streptavidin and of an antibody with its cognate hapten. Our method gives quantitative molecule-counting capabilities with an excellent signal-to-noise ratio and demonstrates a broad dynamic range while retaining easy sample preparation and realistic automation capability. Increased sensitivity and dynamic range are achieved in comparison to currently used array detection methods such as fluorescence, with no signal bleaching, affording high reproducibility and compatibility with miniaturization. Thus, our approach facilitates the determination of the absolute number of molecules bound to the chip rather than their relative amounts, as well as the use of smaller samples.     

Ethical dilemmas in police psychology.

A body of police psychologists was surveyed with regard to the ethical dilemmas that they experienced in providing psychological services to law enforcement organizations. A majority (55%) of the respondents reported that they had encountered an ethical conflict. The most common ethical dilemmas were related to issues of confidentiality, conflicts between the ethical standards of the psychologist and the needs of the agency, and dual relationships. In this article these areas of concern are explored, and suggestions to help resolve these issues are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mixed alkanethiol monolayers on submicrometric gold patterns: a controlled platform for studying cell-ligand interactions

Nanoscale organization of surface ligands often has a critical effect on cell-surface interactions. We have developed an experimental system that allows a high degree of control over the 2-D spatial distribution of ligands. As a proof of concept, we used the developed system to study how T-cell activation is independently affected by antigen density and antigen amount per cell. Arrays of submicrometer gold islands at varying surface coverage were defined on silicon by electron beam lithography (EBL). The gold islands were functionalized with alkanethiol self-assembled monolayers (SAMs) containing a small antigen, 2,4,6-trinotrophenyl (TNP), at various densities. Genetically engineered T-cell hybridomas expressing TNP-specific chimeric T-cell antigen receptor (CAR) were cultured on the SAMs, and their activation was assessed by IL-2 secretion and CD69 expression. It was found that, at constant antigen density, activation increased monotonically with the amount of antigen, while at constant antigen amount activation was maximal at an intermediate antigen density, whose value was independent of the amount of antigen.     

pH on-off switching of antibody-hapten binding by site-specific chemical modification of tyrosine

Tetranitromethane (TNM) chemically mutates the binding sitesof antibodies so that the nitrated antibodies exhibit pH-dependentbinding near physiological pH. Three monoclonal antibodies wereselectively modified, each under different conditions, withthe resultant loss of binding activity at pH > 8 which isrecovered at pH < 6. Recovery and loss of binding are ascribedto the protonation and deprotonation, respectively, of the hydroxylgroup of the resulting 3-nitrotyrosine side chain (pK_a 7) atthe binding site of these antibodies. pH on–off dependencyof binding activity, common to all TNM-modified antibodies studiedby us so far, may find use in a variety of applications in whichcontrolled modulation under mild conditions is required     

Electrically controlled molecular recognition harnessed to activate a cellular response

Seamless embedment of electronic devices in biological systems is expected to add the outstanding computing power, memory, and speed of electronics to the biochemical toolbox of nature. Such amalgamation requires transduction of electronic signals into biochemical cues that affect cells. Inspired by biology, where pathways are directed by molecular recognition, we propose and demonstrate a generic electrical-to-biological transducer comprising a two-state electronic antigen and a chimeric cell receptor engineered to bind the antigen exclusively in its "on" state. T-cells expressing these receptors remain inactivated with the antigen in its "off" state. Switching the antigen to its "on" state by an electrical signal leads to its recognition by the T-cells and correspondingly to cell activation.