New insights on P2X purinoceptors

Significant advances in understanding of P2X purinoceptor pharmacology have been made in the last few years. The limitations of nucleotide agonists as drug tools have now been amply demonstrated. Fortunately, inhibitors of the degrading ecto-ATPase enzymes are becoming available and it has become apparent that the complete removal of all divalent cations can be used experimentally in some systems to prevent nucleotide breakdown. Despite these issues, convincing evidence for P2X receptor heterogeneity, from data with agonists, has recently been reported. A number of new antagonists at P2X purinoceptors have also recently been described which to some degree appear to be more specific and useful than earlier antagonists like suramin. It is now apparent that suramin is a poor antagonist of ATP in many tissues because it potently inhibits ATPase activity at similar concentrations to those at which it blocks the P2X purinoceptor. Advances in the use of radiolabelled nucleotides as radioligands for binding studies has allowed the demonstration of P2X purinoceptors in a variety of tissues throughout the body including the brain. These studies have also provided evidence for receptor heterogeneity. Excitingly, two P2X purinoceptor genes have been cloned but operational studies suggest that more than two types exist. The cloning studies have also demonstrated a unique structure for the P2X purinoceptor which differentiates it from all other ligand-gated ion channel receptors. Further studies on P2X purinoceptor operation and structure are needed to help resolve controversies alluded to regarding the characterization and classification of nucleotide receptors. Hopefully such studies will also lead to a better understanding of the physiological and pathological importance of ATP and its activation of P2X purinoceptors. This will require the identification of better drug tools, in particular antagonists which may also provide the basis for novel therapeutic agents.     

Can blind infants and children use sonar sensory aids?

Discusses research on the use of auditory–spatial perception in sighted and blind children. Infants may use a sonar-sensory device to signal that there is an object to reach for and to explore near space. Mobile infants and toddlers may use the device to help avoid obstacles. School-age Ss can use the device in locomotion, to locate objects, perceive spatial layouts, and to identify surfaces and objects. Ss' level of perceptual and cognitive development influences the use of the sonar aid, and the impact of the aid on general auditory development is unknown. It is suggested that Ss may habituate to aid signals resulting in inattention. (French abstract) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Electrons and Cavitation in Liquid Helium-3

We report preliminary results from a study of the effect of electrons on cav-itation in liquid ³ He. We have measured the negative pressure at which electron bubbles explode. The results are in good agreement with theoretical expectations.     

Introducing the personal software process

The personal software process (PSP) has been developed by the Software Engineering Institute (SEI) to address the improvement needs of individual software engineers. It should also be of help to small projects and modest-sized software organizations. In a one-semester graduate-level course, engineers are introduced to measurement, planning, and quality control methods. A defined sequence of programming exercises are used to illustrate these methods and the exercise data are used to provide the students with feedback on their performance. The PSP course has been taught at five universities at both the graduate and senior undergraduate level. Various PSP introduction methods have also been tried at four industrial organizations, but the course format has also been found most effective. Results to date indicate that PSP training motivates engineers to use disciplined methods and it helps them to achieve significant quality and productivity improvements. While PSP principles have been demonstrated with software engineering students, their effectiveness has not yet been measured in industrial practice. This paper describes the PSP process, the strategic approach and experience to date.This work is supported by the US Department of Defense.     

An extended scheme of magnetic-bubble electronic dictionary

A scheme to incorporate input/output of simplified Chinese characters and phonetic Chinese into an electronic dictionary is described. Allowable search keys include HCH codes for ordinary Chinese characters, HCH codes for simplified Chinese characters, Chinese phonetic codes, Universal Words, and English and French words. The dictionary look-up can be done by specifying part of the key content. A microprocessor-based prototype has been cohstructed to demonstrate the scheme using magnetic bubble memory.     

The differential effects of rape prevention programming on attitudes, behavior, and knowledge.

This investigation evaluated whether type of programming differentially affects elaboration likelihood model central route processing of rape prevention messages, attitudes, knowledge, behaviors, and stability of change. The 258 participants were assigned to a didactic-video program, an interactive drama, or control. Measured over S time periods, results indicated that (a) the interactive drama was most effective in promoting central route processing; (b) the didactic-video intervention was more effective than the control at altering men's rape myth acceptance at 1 month, but change was not stable; (c) a pattern of rebounding scores on rape attitudes occurred for both interventions; (d) interactive drama participants were more able to identify consent versus coercion; and (e) interactive drama participants demonstrated differences on behavioral indicators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigation of a synthetic peptide as immunogen for a variant epidermal growth factor receptor associated with gliomas

We have previously demonstrated antibody production to a glioma-associated variant form of the human epidermal growth factor receptor in rabbits that had received a synthetic peptide mimicking the unique primary structure of the variant protein as immunogen. We report here the response of mice, rabbits, goats, and macaques immunized by various protocols to this peptide. Titers to both peptide- and cell-elaborated variant receptor were measured, and the capacity to recognize the variant receptor in human tumor samples was determined. Within the range of species and strains investigated, we demonstrated a variable species-associated response to the peptide (rabbits > mice > goats > rats > macaques). Rabbits and a single goat produced specific, high titer antibody activity to the variant receptor protein following immunization with peptide alone. Murine titers to the parent protein were not appreciable following peptide immunization alone; additional immunization with variant receptor as expressed on cell membranes was used to boost this response.     

Suspected spinal cord compression in breast cancer patients: a multidisciplinary risk assessment

Most prolactin (PRL) in the circulation is produced by the pituitary. However, a wide variety of traditional target tissues of the hormone have also been shown to produce their own prolactin. The amount produced per cell is low, but may well be sufficient for autocrine/paracrine activity. Although dopamine agonists allow one to study the target tissue effects of pituitary PRL, other agents, such as PRL receptor (PRLR) antagonists, are needed to analyze autocrine/paracrine loops. With PRLR antagonists, it should be possible to dissect out the role of extrapituitary prolactin in both the normal physiology, and the pathophysiology of various tissues. In tissues where the locally produced PRL may promote disease, such antagonists have the potential to be important therapeutics. This article briefly, but critically, reviews current understanding of PRL-receptor interactions and initial signaling, and describes the development of both growth hormone (GH) and PRL antagonists within that context. In the final section, results with a very potent PRL antagonist further one theme of the article, which is whether the simple receptor dimerization model explains all signal transduction following PRLR binding.     

Solute diffusion in swollen membranes. Part V: Solute diffusion in poly(2-hydroxyethyl methacrylate)

Studies with phenylalanine diffusing in well-characterized poly(2-hydroxyethyl methacrylate) (PHEMA) membranes swollen in water at 37°C were conducted. Films were prepared by reaction of HEMA monomer with the cross-linking agent ethylene glycol dimethacrylate (EGDMA) at cross-linking ratios, X, of 0.005, 0.01, 0.0128, 0.025, and 0.050 mole EGDMA/mole HEMA in the presence of 40 weight percent water at 60°C for 12 hours. These membranes were subsequently swollen in water at 37°C and their structure analyzed using a modified Gaussian distribution equation of swelling. The calculated values of M?_c varied between 1,700 and 3,425 daltons, which corresponded to a correlation length of the mesh size, egr, of 24 to 35 A. The phenylalanine solute diffusion coefficient varied from 0.17 × 10^?6 to 0.97 × 10^?6 cm²/s, and depended on the aforementioned structural parameters of the membranes.