The green fields of chromatography.

Researchers are finding that chromatographic separations that use less solvent and stationary phase provide cheaper, more efficient, and more sensitive results. Sarah Webb explores how these changes are leading to the "greening" of chromatography.

Found in translation.

In the quest to move more basic research discoveries into the clinic, the medical community is building training programs to help researchers gain "translational" skills. Sarah Webb explores how PhDs are learning to speak the language of the clinic.

High affinity binding to profilin by a covalently constrained, soluble mimic of phosphatidylinositol-4,5-bisphosphate micelles.

Phosphoinositide (PI) lipids are essential regulators of a wide variety of cellular functions. We present here the preparation of a multivalent analogue of a phosphatidylinositol-4,5-bisphosphate (PIP(2)) micelle containing only the polar headgroup portion of this lipid. We show that this dendrimer binds to the cytoskeletal protein profilin with an affinity indistinguishable from that of PIP(2), despite the fact that profilin discriminates between PIP(2) and its monomeric hydrolysis product inositol-1,4,5-triphosphate (IP(3)) under physiological conditions. These data demonstrate that the diacylglycerol (DAG) moiety of PIP(2) is not required for high-affinity binding and suggest that profilin uses multivalency as a key means to distinguish between the intact lipid and IP(3). The class of soluble membrane analogues described here is likely to have broad applicability in the study of protein.PI interactions.

Cannabinoid receptor antagonism increases female sexual motivation.

The current experiments examined whether treatment with a CB1 antagonist/inverse agonist (AM251) affects sexual motivation, proceptivity, and receptivity in female rats. In experiment #1, 92 Long-Evans rats were tested for their socio-sexual motivation via a runway methodology. Motivation to approach and maintain close proximity to an empty goalbox, a female, and a male target was assessed following hormonal and drug treatment. Hormone treatments were: oil vehicle, 10 microg estradiol, and 10 microg estradiol+500 microg progesterone. Drug doses were 0, 2, and 4 mg/kg AM251 (IP, 60 min prior to testing). In experiment #2, 32 female subjects were tested for receptivity and proceptivity in a paced mating chamber. Subjects were given either a high (10 microg estradiol+500 microg progesterone) or low dose of hormones (2 microg estradiol+250 microg progesterone), and either vehicle or 2 mg/kg AM251. AM251 significantly increased sexual motivation for a male target in the runway in females primed with both estradiol and progesterone. AM251 also enhanced lordosis (in low hormone females) and increased hop-darts. These findings suggest that endocannabinoids tonically inhibit estrous behaviors. Cannabinoid antagonists could serve as new treatment option for women suffering from abnormally low libido.

Comparison of self-report measures for identifying late-life generalized anxiety in primary care.

This study evaluated the Penn State Worry Questionnaire, Penn State Worry Questionnaire-Abbreviated, and the Generalized Anxiety Disorder Questionnaire-IV for identifying generalized anxiety disorder in older medical patients. Participants were 191 of 281 patients screened for a clinical trial evaluating cognitive-behavior treatment, n = 110 with generalized anxiety disorder, 81 without. Participants completed the Penn State Worry Questionnaire and Generalized Anxiety Disorder Questionnaire-IV at pretreatment. Kappa coefficients estimated agreement with the Structured Clinical Interview for Diagnosis. Receiver operating characteristic curves compared sensitivity and specificity of self-report measures. The Penn State Worry Questionnaire (cutoff = 50) provided the strongest prediction of generalized anxiety disorder (sensitivity, 76%; specificity, 73%; 75% correctly classified; kappa = .49. Item 2 of the Generalized Anxiety Disorder Questionnaire-IV demonstrated comparable accuracy. The Penn State Worry Questionnaire, Generalized Anxiety Disorder Questionnaire-IV, and briefer versions of these measures may be useful in identifying late-life generalized anxiety disorder in medical settings.

Treatment outcome for adolescent obsessive-compulsive disorder in a specialized hospital setting.

Although few data are available concerning adolescents with obsessive-compulsive disorder (OCD), the existing literature suggests that cognitive-behavioral therapy (CBT) is the first-line treatment of choice for adolescents with mild to moderate OCD. A combination of CBT and serotonin reuptake inhibitors (SRIs) is recommended for more severe forms of OCD, based on the Expert Consensus Guidelines for the Treatment of Obsessive-Compulsive Disorder and the Pediatric OCD Treatment Study (POTS). Despite the effectiveness of CBT, a recent meta-analysis found that 27% of adolescent outpatients fail to show clinically significant improvement following CBT and many also fail to show improvement with pharmacotherapy. One alternative for those who do not improve with outpatient treatment is an intensive inpatient program. Within the last 10 years, two specialty hospitals have created programs that provide intensive CBT milieu treatment with multidisciplinary support (e.g., nursing, psychopharmacology) to treat adolescents with OCD. This naturalistic study describes treatment outcomes in 23 patients who received treatment in one of these programs between 2005 and 2006. Results suggest significant improvements on the majority of outcome measures, with 70% of the patients judged to meet criteria for clinically significant change. Thus, inpatient treatment appears potentially efficacious, although future controlled trials with larger samples are needed.

Synthesis and characterization of covalent mimics of phosphatidylinositol-4,5-bisphosphate micelles.

There is increasing evidence that multivalency plays an important role in protein-lipid recognition and membrane targeting in biological systems. We describe here the preparation and characterization of multivalent analogues of the signaling lipid phosphatidylinositol-4,5-bisphosphate (PIP2). Tetherable analogues of the PIP2 headgroup were appended to polyamidoamine dendrimers via a squarate linker to afford polymers displaying four or eight headgroup moieties. This class of molecules should provide a powerful tool for the study of protein-lipid interactions.

Psychophysiological profiles of batterers: autonomic emotional reactivity as it predicts the antisocial spectrum of behavior among intimate partner abusers.

On the basis of studies finding heart rate deceleration among severely violent (SV) batterers (J. M. Gottman et al., 1995) and unsuccessful psychopaths (S. S. Ishikawa, A. Raine, T. Lencz, S. Bihrle, & L. Lacasse, 2001), this study compares the physiological reactivity of SV batterers (n=35) with low-level violent (LLV) batterers (n=37) and nonviolent men (n=21) during 2 laboratory tasks. Men's heart rate and skin conductance level were recorded during baseline, a conflict discussion, and a standardized anger induction. Results suggest that autonomic hyporeactivity is a risk marker for antisocial features among SV men, whereas autonomic hyperreactivity is a risk marker among LLV men. Psychophysiological responding appears to be a stronger correlate of general antisocial behavior than of intimate partner abuse.

A second failure to replicate the Gottman et al. (1995) typology of men who abuse intimate partners...and possible reasons why.

The present study attempts to replicate Gottman et al.'s (1995; see record 1995-44075-001; and Jacobson & Gottman, 1998) psychophysiological study that classifies partner assaultive men into two distinct groups: heart rate (HR) decelerators (Type 1 batterers) and HR accelerators (Type 2 batterers). Current results indicate no significant differences between Type 1 and Type 2 batterers on the antisocial spectrum of behaviors. Resting HR, rather than HR change, was negatively related to the antisocial spectrum of behavior for batterers with severe, clinical levels of violence only. Reasons for subsequent failures to replicate the Type 1 versus Type 2 distinctions may be attributable to unusually high autonomic arousal during baseline in the original study. Consideration of resting HR and the use of dimensional as opposed to categorical approaches in analyzing the heterogeneity of batterers are proposed as possible solutions to clarifying inconsistencies across laboratories.

Engineering of tooth-supporting structures by delivery of PDGF gene therapy vectors.

Platelet-derived growth factor (PDGF) exerts potent effects on wound healing including the regeneration of tooth-supporting structures. Limitations of topical protein delivery to periodontal osseous defects include transient biological activity and the bioavailability of PDGF at the wound site. The objective of this investigation was to determine the feasibility of in vivo PDGF-B gene transfer to stimulate periodontal tissue regeneration in large tooth-associated alveolar bone defects in rats. Periodontal lesions (0.3 x 0.2 cm in size) were treated with a 2.6% collagen matrix alone or a matrix containing adenoviruses encoding luciferase (control), a dominant negative mutant of PDGF-A (PDGF-1308), or PDGF-B. Block biopsies were harvested at 3, 7, and 14 days post-gene delivery and descriptive histology and histomorphometric analyses were performed. The defects treated with Ad-PDGF-B demonstrated greater proliferating cell nuclear antigen positively stained cells and strong evidence of bone and cementum regeneration beyond that of Ad-luciferase and Ad-PDGF-1308 groups. Quantitative image analysis showed a nearly fourfold increase in bridging bone and sixfold increase in tooth-lining cemental repair in the Ad-PDGF-B-treated sites compared to lesions treated with Ad-luciferase or collagen matrix alone, which showed limited hard tissue neogenesis. In addition, the Xenogen In Vivo Imaging System revealed sustained and localized gene expression of the luciferase reporter at the periodontal lesions for up to 21 days after gene transfer. These results indicate that in vivo direct gene transfer of PDGF-B stimulates alveolar bone and cementum regeneration in large periodontal defects. Gene therapy utilizing PDGF-B may offer the potential for periodontal tissue engineering applications.

Platelet-derived growth factor gene delivery stimulates ex vivo gingival repair.

Destruction of tooth support due to the chronic inflammatory disease periodontitis is a major cause of tooth loss. There are limitations with available treatment options to tissue engineer soft tissue periodontal defects. The exogenous application of growth factors (GFs) such as platelet-derived growth factor (PDGF) has shown promise to enhance oral and periodontal tissue regeneration. However, the topical administration of GFs has not led to clinically significant improvements in tissue regeneration because of problems in maintaining therapeutic protein levels at the defect site. The utilization of PDGF gene transfer may circumvent many of the limitations with protein delivery to soft tissue wounds. The objective of this study was to test the effect of PDGF-A and PDGF-B gene transfer to human gingival fibroblasts (HGFs) on ex vivo repair in three-dimensional collagen lattices. HGFs were transduced with adenovirus encoding PDGF-A and PDGF-B genes. Defect fill of bilayer collagen gels was measured by image analysis of cell repopulation into the gingival defects. The modulation of gene expression at the defect site and periphery was measured by RT-PCR during a 10-day time course after gene delivery. The results demonstrated that PDGF-B gene transfer stimulated potent (>4-fold) increases in cell repopulation and defect fill above that of PDGF-A and corresponding controls. PDGF-A and PDGF-B gene expression was maintained for at least 10 days. PDGF gene transfer upregulated the expression of phosphatidylinosital 3-kinase and integrin alpha5 subunit at 5 days after adenovirus transduction. These results suggest that PDGF gene transfer has potential for periodontal soft tissue-engineering applications.