On the learning of addictive behavior: Sensation-seeking propensity predicts dopamine turnover in dorsal striatum

Brain Imaging and Behavior - We asked if sensation-seeking is linked to premorbid personality characteristics in patients with addictive disorders, or the characteristics follow the...     

Differential expression of perforin in muscle-infiltrating T cells in polymyositis and dermatomyositis.

Polymyositis (PM) and dermatomyositis (DM) are the prototypical inflammatory diseases of skeletal muscle. In PM, CD8+ T cells invade and destroy muscle fibers, whereas humoral effector mechanisms prevail in DM. We studied the expression of the cytotoxic mediator perforin in inflammatory cells in PM and DM muscle by semiquantitative PCR, immunohistochemistry and confocal laser microscopy. Similar levels of perforin mRNA were expressed in PM and DM, and abundant perforin-expressing CD3+CD8+ and CD3+ CD4+ T cells were observed in both diseases. However, there was a striking difference in the intracellular localization of perforin. In DM, perforin was distributed randomly in the cytoplasm of the inflammatory T cells. In contrast, 43% of the CD8+ T cells that contacted a muscle fiber in PM showed perforin located vectorially towards the target muscle fiber. The results suggest (a) that the random distribution of perforin in the cytoplasm of muscle-infiltrating T cells observed in DM reflects nonspecific activation, and (b) that the vectorial orientation observed only in PM reflects the specific recognition via the T cell receptor of an antigen on the muscle fiber surface, pointing to a perforin- and secretion-dependent mechanism of muscle fiber injury.     

The role of mechanotransduction in heart failure pathobiology—a concise review

Heart Failure Reviews - This review evaluates the role of mechanotransduction (MT) in heart failure (HF) pathobiology. Cardiac functional and structural modifications are regulated by biomechanical...     

Advancing the clinical nurse leader model through academic-practice-policy partnership

The nursing profession is tasked with identifying and evaluating models of care with potential to add value to health care delivery. In consideration of this goal, we describe the Clinical Nurse Leader (CNL) initiative and the activities of a national-level CNL research collaborative. The CNL initiative, launched by the American Association of Colleges of Nursing in collaboration with education and healthcare leaders, has delineated CNL education curriculum and practice competencies, and fostered the creation of academic-practice-policy partnerships to pilot CNL integration into frontline nursing care delivery. The partnership has evolved into an Agency for Healthcare Research and Quality affiliate practice-based research network, the CNL Research Collaborative, which links research, policy, education, and practice stakeholders to advance the CNL evidence base. We summarize foundational CNLRC research to explain CNL practice, quantify CNL effectiveness, and bring clarity to how CNLs can be implemented to consistently influence care, quality, and safety.     

Biosynthesis of the Pseudomonas polyketide coronafacic acid requires monofunctional and multifunctional polyketide synthase proteins

Coronafacic acid (CFA) is the polyketide component of the phytotoxin coronatine, a virulence factor of the plant pathogen Pseudomonas syringae. Our current knowledge of polyketide biosynthesis largely is based on the analysis of polyketide synthases (PKSs) in actinomycetes and other Gram-positive bacteria. Consequently, the cloning and characterization of the CFA biosynthetic gene cluster will contribute significantly to our knowledge of polyketide synthesis in Pseudomonas. In this report, we describe two genes in the CFA biosynthetic gene cluster that encode PKSs that are structurally and functionally similar to the multifunctional modular PKSs, which catalyze the synthesis of macrolide antibiotics. The CFA PKS genes were overproduced in Escherichia coli and shown to cross-react with antisera made to a modular PKS involved in erythromycin synthesis. A scheme for CFA biosynthesis is presented that incorporates the activities of all proteins in the CFA PKS. In this report a gene cluster encoding a pseudomonad polyketide has been completely sequenced and the deduced gene functions have been used to develop a biosynthetic scheme.     

Initial findings concerning a sexual knowledge questionnaire

SUMMARY: The authors describe a 69 item sexual knowledge questionnaire that covers the areas: physiology, pregnancy, the sex act, masturbation, contraception, types of sexuality, and venereal disease. There is also a ‘Belief in Myths’ scale. Mean scores for delinquent boys and young mentally handicapped adults are given, with the latter having lower scores. All areas correlate with total score. The handicapped group showed increased sexual knowledge when re-tested after a human relations course. A control group, tested after the same interval, showed only random changes. Further research is suggested.     

Analysis During Sinus Rhythm of Critical Sites in Reentry Circuits of Postinfarction Ventricular Tachycardia

Background: Critical sites within reentry circuits of postinfarction ventricular tachycardia (VT) were identified during sinus rhythm (SR) and VT to determine whether electrogram characteristics during SR may be helpful in identifying successful ablation sites. Methods: In 33 patients (mean age 67 ± 11 yrs) with prior infarction, mapping and radiofrequency (RF) catheter ablation of 57 hemodynamically-tolerated VT's (cycle length 478 ± 96) were performed. The morphologies of electrograms (EGM) at sites of concealed entrainment (CE) were compared during SR and VT. RF energy was delivered at 94 sites (51 successful and 43 unsuccessful ablation sites). Results: During SR, isolated potentials (IP), but not late potentials (LP) recorded via the mapping catheter, were associated with successful ablation. At 29/39 sites with an IP during sinus rhythm, an isolated diastolic potential (IDP) also was present during VT, whereas at 4 sites IP's were present only during SR (p < 0.001). At 11/29 sites where isolated potentials were present during SR and VT, the morphology of the isolated potential during VT and SR was similar; and all but one of these sites were successful ablation sites (p = 0.01). The EGM amplitude during VT correlated with the amplitude during SR (R = 0.9, p < 0.001). An identical pacemap was present during SR at 33/94 sites; this was not associated with successful ablation. Conclusion: SR mapping may be helpful in identifying critical sites of reentry in postinfarction VT. At sites within the reentry circuit, characteristics of sinus rhythm EGM's that are associated with successful ablation include the presence of IP's, but not the presence of LP's.