Carotid artery plaque composition : Relationship to clinical presentation and ultrasound B-mode imaging

Objective: To correlate B-mode ultrasound findings to carotid plaque histology. Design: European multicentre study (nine centres). Material and Methods: Clinical presentation and risk factors were recorded and preoperative ultrasound Duplex scanning with special emphasis on B-mode imaging studies was performed in 270 patients undergoing carotid endarterectomy. Perioperatively macroscopic plaque features were evaluated and the removed specimens were analysed histologically for fibrous tissue, calcification and 'soft tissue' (primarily haemorrhage and lipid). Results: Males had more soft tissue than females (p = 0.0006), hypertensive patients less soft tissue than normotensive (p = 0.01) and patients with recent symptoms more soft tissue than patients with earlier symptoms (p = 0.004). There was no correlation between surface description on ultrasound images compared to the surface judged intraoperatively by the surgeon. Echogenicity on B-mode images was inversely related to soft tissue (p=0.005) and calcification ions directly related to echogenicity (p < 0.0001). Heterogeneous plaques contained more calcification than homogeneous (p = 0.003), however there was no difference in content of soft tissue. Conclusion: Ultrasound B-mode characteristics are related to the histological composition of carotid artery plaques and to patient's history. These results may imply that patients with distant symptoms may be regarded and treated as asymptomatic patients whereas asymptomatic patients with echolucent plaques should be considered for carotid endarterectomy

Dendrimers as biopharmaceuticals: Synthesis and properties

Two general aspects which need to be considered for the successful application of dendrimers for biomedical purposes are their availability at an acceptable cost and their suitability as regards their pharmacodynamic and pharmacokinetic properties. These two aspects are covered in this review. In the first part, synthetic strategies for the preparation of dendrimers are outlined and emphasis is given to recent work on methodologies whose aim is the development of more efficient routes to dendrimers in terms of the materials used for their synthesis as well as in terms of the procedures required for their purification. These include procedures involving double-stage and double exponential synthesis, orthogonal coupling strategies, self-assembly and solid-phase approaches, as well as particularly useful synthetic protocols such as those used in &quot;click chemistry&quot;. The second part of the review deals with the way in which the size, chemical constitution and physicochemical properties of dendrimers used for drug delivery may affect pharmacodynamic and pharmacokinetic parameters which are important considerations for drug bioavailability. This is illustrated by an overview of examples from recent work involving non-steroidal anti-inflammatory drugs, anticancer drugs and antibacterials. © 2008 Bentham Science Publishers Ltd

Cohesion as Shared Beliefs in Exercise Classes

The purpose of the study was to determine if perceptions of cohesion in exercise classes demonstrated sufficiently high consensus and between-group variance to support a conclusion that exercise classes are groups. Participants (N = 1,700) in 130classes were tested on either the Group Environment Questionnaire (GEQ) or the Physical Activity Group Environment Questionnaire (PAGEQ). Results showed that exercise classes satisfied the statistical criteria necessary to support a conclusion that they are true groups; that is, they exhibited acceptable levels of consensus about cohesion within classes and acceptable differences in cohesion between classes. In addition, index-of-agreement values were significantly greater for participants completing the PAGEQ than for participants completing the GEQ. Finally, consensus was greatest when participants evaluated how the exercise class satisfied their own personal task needs (i.e., individual attractions to the group-task), and second greatest when participants evaluated the collective unity around the task objectives (i.e., group integration-task)