Resonance frequency analysis: measuring implant stability and osseointegration

Achievement and maintenance of implant stability are prerequisites for long-term positive outcomes for osseointegrated implants. Thus, implant stability is the key to clinical success. Until recently, it was not possible for the clinician to predictably distinguish implants with different degrees of stability. Because there seems to be a correlation between implant failure and bone properties, it is possible that clinically firms implants with poor stability are more prone to failure than more stable implants. This article discusses the development and possible future use of a novel technique for clinical measurement of implant stability and osseointegration--resonance frequency analysis.     

The role of anterior ectosylvian cortex in cross-modality orientation and approach behavior

Benzoporphyrin derivative (BPD), a sensitizer currently in clinical trials, was evaluated for the treatment of experimental Greene melanoma implanted in the rabbit iris. To improve tumor targeting, BPD was complexed with low-density lipoprotein (LDL) representing an endogenous carrier system for BPD as previously described. Twelve tumors were irradiated at a sensitizer dose of 2 mg kg-1 body weight using a dye laser at 692 nm. Tumor responses were documented by photography, angiography and light and electron microscopy. All tumors treated with 80 J cm-2 regressed irreversibly. The principal mechanism of tumor necrosis was thrombosis following disruption of endothelial membranes. Ultrastructure data suggested tumor cell damage, although evidence for this being the result of direct PDT-mediated tumor cell death was less clear. These data suggest that BPD-LDL may be used to improve the selectivity of photodynamic tumor therapy possibly by the increased uptake of lipoprotein-delivered sensitizer to neovascular endothelial cells.     

A new perspective on women's math achievement.

This article presents an examination of the little noted sex-related difference in classroom grades. In contrast to standardized measures of mathematics achievement, girls receive better math grades than do boys. Three hypotheses are proposed to account for this difference. The first hypothesis proposes that boys' greater math experience facilitates their performance on standardized tests. The second hypothesis proposes that math learning styles account for the observed differences. Autonomous learning behavior is presumed to facilitate performance on standardized tests, whereas rote learning is presumed to facilitate performance on classroom exams. The third hypothesis proposes that boys and girls respond differently to novel and familiar achievement situations. It is hypothesized that girls do better when dealing with familiar situations such as classroom exams, whereas boys do better when dealing with novel situations such as standardized tests. Theoretical and empirical evidence consistent with each hypothesis is reviewed, and directions for further research are explored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A system for classifying mechanical injuries of the eye (globe). The Ocular Trauma Classification Group

PURPOSE: To develop a classification system for mechanical injuries of the eye. METHODS: The Ocular Trauma Classification Group, a committee of 13 ophthalmologists from seven separate institutions, was organized to discuss the standardization of ocular trauma classification. To develop the classification system, the group reviewed trauma classification systems in ophthalmology and general medicine and, in detail, reports on the characteristics and outcomes of eye trauma, then established a classification system based on standard terminology and features of eye injuries at initial examination that have demonstrated prognostic significance. RESULTS: This system classifies both open-globe and closed-globe injuries according to four separate variables: type of injury, based on the mechanism of injury; grade of injury, defined by visual acuity in the injured eye at initial examination; pupil, defined as the presence or absence of a relative afferent pupillary defect in the injured eye; and zone of injury, based on the anteroposterior extent of the injury. This system is designed to be used by ophthalmologists and nonophthalmologists who care for patients or conduct research on ocular injuries. An ocular injury is classified during the initial examination or at the time of the primary surgical intervention and does not require extraordinary testing. CONCLUSIONS: This classification system will categorize ocular injuries at the time of initial examination. It is designed to promote the use of standard terminology and assessment, with applications to clinical management and research stud ies regarding eye injuries.     

Mating-related stimulation induces phosphorylation of dopamine- and cyclic AMP-regulated phosphoprotein-32 in progestin receptor-containing areas in the female rat brain

Vaginal-cervical stimulation induces a number of physiological and behavioral events, including the facilitation of mating behavior. Although the facilitation of one component of mating behavior, lordosis, by vaginal-cervical stimulation does not require the presence of progesterone, it appears to be mediated by neural progestin receptors. Abundant evidence suggests that dopamine may play a role in the neural circuitry activated by vaginal-cervical stimulation, including the mating-induced release of dopamine in progestin receptor-containing areas of the brain, changes in the activational state of progestin receptors because of dopamine D1 receptor stimulation, facilitation of lordosis by D1 receptor stimulation in estradiol-primed rats via progesterone-independent events, and D1 agonist-induced neuronal responses in progestin receptor-containing areas and cells. We tested the hypothesis that vaginal-cervical stimulation induces phosphorylation of dopamine- and cyclic AMP-regulated phosphoprotein (DARPP-32; Mr = 32,000), a protein phosphorylated predominantly in response to the stimulation of D1 receptors. At 9 d after ovariectomy, female rats were injected subcutaneously with a behaviorally effective dose of estradiol benzoate. At 48 hr later they received vaginal-cervical or control (perineal) stimulation, and they were perfused 1 hr later. Vaginal-cervical stimulation increased the number of cells expressing pDARPP-32 immunoreactivity by 92% in the medial preoptic nucleus, 134% in the caudal ventromedial hypothalamic nucleus, 123% in the posterodorsal medial amygdala, and 103% in the bed nucleus of the stria terminalis. These results suggest that some of the neuronal effects of vaginal-cervical stimulation, and perhaps other social or environmental stimuli, are mediated by phosphorylation of DARPP-32, perhaps via stimulation of D1 receptors, within progestin receptor-containing areas.     

Changing personality patterns of police officers.

Twenty-five police officers were evaluated at or shortly after their recruitment and again 2 years later. Eleven of the officers were available for follow-up 4 years after recruitment. Minnesota Multiphasic Personality Inventory (MMPI) scores showed significant changes over time, suggesting increasing somatic symptoms, anxiety, and alcohol vulnerability. The increased vulnerability to alcohol abuse was the strongest finding, and by the 4th year of service, mean MacAndrews Alcoholism Scale scores were within the critical range. Results are discussed in terms of the peculiar stresses of police work and the need for periodic reevaluation to prevent stress-associated problems and also initiate early intervention programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Justifying multimachine systems: An integrated strategic approach

Current problems in justifying multimachine systems are analyzed and an integrated framework is developed in which both strategic and tactical considerations are included. At the strategic level the tools for project selection are reviewed, followed by the economic analysis normally required for these systems. Special tools, notably simulation, are illustrated through an example situation.     

Highlights in the development of the Human Resources Research Organization (HumRRO).

Traces the development of HumRRO from its establishment in 1951 at the request of the US Department of the Army to perform research in training methods, motivation, morale and leadership, and psychological warfare to its current status as an independent, nonprofit corporation engaged in research and development to improve human performance in various organizational settings. Four points of contrast between HumRRO's operation as a Federal Contract Research Center and as an independent contractor are examined. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)