Adjunctive stent implantation following directional coronary atherectomy in patients with coronary artery disease

Objectives. This prospective case-control study evaluated the acute and long-term results of stent implantation preceded by debulking of the plaque by means of directional coronary atherectomy.

Background. In comparison with balloon angioplasty, intracoronary stenting produces a larger luminal diameter, maintains artery patency and reduces the incidence of restenosis. Optimal stent deployment is a pivotal factor for achieving the best results, but the bulk of the atherosclerotic plaque opposes stent expansion and may limit the success of the procedure. Debulking of the plaque may provide a better milieu for optimal stent deployment.

Methods. Directional coronary atherectomy followed by a single Palmaz-Schatz stent implantation was attempted in 100 patients. The successes, complications and angiographic results of the combined procedure were evaluated both acutely and during follow-up. Matched patients undergoing successful Palmaz-Schatz stent implantation alone during the same period served as controls.

Results. Atherectomy followed by stent implantation was performed in 94 patients with 98 lesions; periprocedural complications were observed in four cases. The stenosis diameter decreased from 76 ± 9% at baseline to 30 ± 13% after atherectomy (p < 0.0001), and 5 ± 9% after stent implantation (p < 0.0001); it increased to 27 ± 15% at 6-month angiography (p < 0.0001). During the 14 ± 10 months of follow-up, none of the patients died or experienced myocardial infarction, but three patients underwent target lesion revascularization. The patients undergoing stent implantation alone achieved smaller acute gains, tended to have a higher late lumen loss, had a higher restenosis rate (30.5% vs. 6.8%, p < 0.0001) and showed a greater incidence of clinical events during follow-up (p < 0.0001).

Conclusions. Debulking atherosclerotic lesions by means of directional coronary atherectomy before stent implantation is a safe procedure with a high success rate and a low incidence of restenosis at follow-up.     

The phlebologist confronted with the neurologic foot. Phlebologic aspects of the neurologic foot

Vascular complications are frequent in paralyzing neurologic disorders, particularly in peripheral neurologic diseases: edema of the declive, cold feet, acrocyanosis, increased sudation. An enlarged leg in a paralyzed subject presenting frequently reduced sensitivity may indicate phlebitis, but also hematoma of an undetected fracture, or osteoarthropathy. Trophic disorders, such as edema, ulcerative hyperkeratosis and subcutaneous hematoma, are sometimes indicative of an unrecognized peripheral neuropathy, notably diabetic. Sclerous complications of venous impairment, or trophic disorders in algesic dystrophy, may result in incorrect diagnosis of a neurologic disorder. In practical therapeutic terms, it is necessary to emphasize the value of elastic retention, attentive pedicure and flexible and shock-absorbing footwear.     

Protected block time for teaching and learning in a postgraduate family practice residency program

Objective

To explore the elements necessary for a high-quality educational experience in a family practice residency program with respect to scheduling, learning environment, and approaches to teaching and learning.

Design

An interpretative, qualitative study using a generative-inquiry approach.

Setting

The Nanaimo Site of the University of British Columbia Family Practice Residency Program.

Participants

Fifteen physician instructors and 16 first- and second-year residents.

Methods

Data were gathered from 2 qualitative focus group interviews with residents; 2 qualitative focus group interviews with physician instructors; and structured and semistructured observation of 2 in-class seminars, with a focus on residents’ engagement with the class. Results were analyzed and categorized into themes independently and collectively by the researchers.

Main findings

Protected block time for teaching and learning at the Nanaimo Site has been effective in fostering a learning environment that supports collegial relationships and in-depth instruction. Residents and physician instructors benefit from the week-long academic schedule and the opportunity to teach and learn collaboratively. Participants specifically value the connections among learning environment, collegiality, relationships, reflective learning, and the teaching and learning process.

Conclusion

These findings suggest that strategic planning and scheduling of teaching and learning sessions in residency programs are important to promoting a comprehensive educational experience.     

Theophylline inhibits late asthmatic reactions induced by toluene diisocyanate in sensitised subjects.

Toluene diisocyanate (TDI)-induced asthma is a frequent occupational airway disease. To determine whether a calibrated dosage of oral slow-release theophylline inhibits asthmatic reactions and the associated increase of airway responsiveness to methacholine induced by TDI, we examined six asthmatic subjects who developed a late or a dual asthmatic reaction after TDI inhalation challenge. We administered oral slow-release theophylline or placebo to each subject for 7 days according to a double-blind, randomized, cross-over study design. When the subjects received a placebo, TDI caused a late or a dual asthmatic reaction. When the subjects received theophylline. TDI caused significantly reduced late asthmatic reactions. Mean serum theophylline concentrations were within the therapeutic range. Theophylline neither modified the baseline airway responsiveness to methacholine, nor the increase of airway responsiveness to methacholine induced by TDI. These results suggest that slow-release theophylline may improve TDI-induced late asthmatic reactions, but it does not change the baseline airway responsiveness to methacholine and the increase of airway responsiveness to methacholine induced by TDI.     

IGF-I enhances cortisol secretion from guinea-pig adrenal gland: in vivo and in vitro study

Insulin-like growth factor (IGF)-I is a ubiquitously synthesized peptide that, along with IGF-II, acts via the IGF-R type I receptor. IGF-I and its receptor are expressed in the adrenal gland of humans and bovines, the secretion of which they seem to stimulate. As in humans and cows, the main glucocorticoid hormone secreted by guinea-pig adrenals is cortisol, and hence we have studied the adrenocortical effects of IGF-I in this species. In vivo experiments showed that prolonged IGF-I administration raised the plasma concentration of cortisol in both normal and dexamethasone/captopril-treated guinea pigs, thereby ruling out the possibility that IGF-I may act by activating the hypothalamic-pituitary-adrenal axis and the renin-angiotensin system. In vitro experiments demonstrated that IGF-I enhanced basal, but not maximally agonist [ACTH and angiotensin-II (Ang-II)]-stimulated, cortisol secretion from freshly dispersed guinea-pig inner adrenocortical cells. The IGF-I immuno-neutralization suppressed the IGF-I secretagogue effect, without altering the cortisol response to both ACTH and Ang-II. IGF-I raised cyclic-AMP and inositol triphosphate release from dispersed guinea-pig cells, and the effect was reversed by the adenylate cyclase inhibitor SQ-22536 and the phospholipase-C (PLC) inhibitor U-73122. SQ-22536, U-73122, the protein kinase (PK) A inhibitor H-89 and the PKC inhibitor calphostin-C decreased by approximately 50% the cortisol response of dispersed cells to IGF-I, and the combined exposure to SQ-22536 and U-73122 abolished it. We conclude that IGF-I stimulates glucocorticoid secretion from guinea-pig adrenocortical cells, acting via selective receptors coupled to both the adenylate cyclase/PKA- and PLC/PKC-dependent signaling cascades.     

Getting across the plasma membrane and beyond: intracellular uses of colloidal semiconductor nanocrystals

Semiconductor nanocrystals (NCs) are increasingly being used as photoluminescen markers in biological imaging. Their brightness, large Stokes shift, and high photostability compared to organic fluorophores permit the exploration of biological phenomena at the single-molecule scale with superior temporal resolution and spatial precision. NCs have predominantly been used as extracellular markers for tagging and tracking membrane proteins. Successful internalization and intracellular labelling with NCs have been demonstrated for both fixed immunolabelled and live cells. However, the precise localization and subcellular compartment labelled are less clear. Generally, live cell studies are limited by the requirement of fairly invasive protocols for loading NCs and the relatively large size of NCs compared to the cellular machinery, along with the subsequent sequestration of NCs in endosomal/lysosomal compartments. For long-period observation the potential cytotoxicity of cytoplasmically loaded NCs must be evaluated. This review focuses on the challenges of intracellular uses of NCs.     

Bovine lactoferrin inhibits adenovirus infection by interacting with viral structural polypeptides

We recently demonstrated that lactoferrin, an antimicrobial glycoprotein, can inhibit adenovirus infection by competing for common glycosaminoglycan receptors. This study further characterizes the antiadenovirus activity of the protein, thus demonstrating that lactoferrin neutralizes infection by binding to adenovirus particles and that its targets are viral III and IIIa structural polypeptides.