Publications by authors named "Susan McKay"

Background: Enhanced recovery after surgery (ERAS) colorectal guideline implementation has occurred primarily in standalone institutions worldwide. We implemented the guideline in a single provincial healthcare system, and our study examined the effect of the guideline on patient outcomes [length of stay (LOS), complications, and 30-day post-discharge readmissions] across a healthcare system.

Methods: We compared pre- and post-guideline implementation in consecutive elective colorectal patients, ≥ 18 years, from six Alberta hospitals between February 2013 and December 2014.

View Article and Find Full Text PDF

Nicotinic acetylcholine receptor (nAChR) cell surface expression levels are modulated during nicotine dependence and multiple disorders of the nervous system, but the mechanisms underlying nAChR trafficking remain unclear. To determine the role of cysteine residues, including their palmitoylation, on neuronal α4 nAChR subunit maturation and cell surface trafficking, the cysteines in the two intracellular regions of the receptor were replaced with serines using site-directed mutagenesis. Palmitoylation is a post-translational modification that regulates membrane receptor trafficking and function.

View Article and Find Full Text PDF

• Inorganic arsenic (As(i) ) in rice (Oryza sativa) grains is a possible threat to human health, with risk being strongly linked to total dietary rice consumption and consumed rice As(i) content. This study aimed to identify the range and stability of genetic variation in grain arsenic (As) in rice. • Six field trials were conducted (one each in Bangladesh and China, two in Arkansas, USA over 2 yr, and two in Texas, USA comparing flooded and nonflood treatments) on a large number of common rice cultivars (c.

View Article and Find Full Text PDF

We calculate the local contributions to the Shannon entropy and excess entropy and use these information theoretic measures as quantitative probes of the order arising from quenched disorder in the diluted Ising antiferromagnet on a triangular lattice. When one sublattice is sufficiently diluted, the system undergoes a temperature-driven phase transition, with the other two sublattices developing magnetizations of equal magnitude and opposite sign as the system is cooled.(1) The diluted sublattice has no net magnetization but exhibits spin glass ordering.

View Article and Find Full Text PDF

Evidence exists supporting the involvement of adenomatous polyposis coli (APC) protein in the assembly of neuronal nicotinic acetylcholine receptors (nAChRs) in the postsynaptic complex. In the following studies, the effects of APC protein on cellular distribution of recombinant α3β4 nAChRs was investigated. RT-PCR and Western blotting techniques established the expression of APC protein both in bovine adrenal chromaffin cells, which express native α3β4* nAChRs, and in a HEK293 cell line expressing recombinant bovine adrenal α3β4 nAChRs (BMα3β4 cells).

View Article and Find Full Text PDF
Article Synopsis
  • The study uncovers a new functional link between alpha4beta2 AChRs and neurexin-1beta, a presynaptic cell adhesion molecule, which is essential for their organization at synapses.
  • When alpha4beta2 AChRs and neurexin-1beta are coexpressed in hippocampal neurons, they are effectively targeted to synapses, but this targeting is hindered by a mutant form of neurexin-1beta lacking an extracellular domain.
  • These findings suggest that dysfunctions in neurexin-1 may play a role in neurological conditions like nicotine dependence and autism spectrum disorders by affecting the positioning of alpha4beta2 AChRs at synapses.
View Article and Find Full Text PDF

Allosteric modulation of nAChRs is considered to be one of the most promising approaches for drug design targeting nicotinic acetylcholine receptors (nAChRs). We have reported previously on the pharmacological activity of several compounds that seem to act noncompetitively to inhibit the activation of alpha3beta4(*) nAChRs. In this study, the effects of 51 structurally similar molecules on native and recombinant alpha3beta4 nAChRs are characterized.

View Article and Find Full Text PDF

Novel 3,5-disubstituted ring E analogs of methyllycaconitine were prepared and evaluated in nicotinic acetylcholine receptor binding assays. The desired analogs were prepared through the Suzuki-Miyaura cross-coupling reaction of methyl 5-bromo-nicotinate. The Suzuki-Miyaura cross-coupling reactions of pyridines with electron withdrawing substituents have not been extensively described previously.

View Article and Find Full Text PDF

Controversy surrounds the expression of alpha7 nicotinic acetylcholine receptors (nAChRs) in adrenal chromaffin cells. In these studies, alpha7 nAChRs expressed in bovine adrenal chromaffin cells are investigated. Using radiolabeled ligand binding techniques, [(125)I]alpha-bungarotoxin (alphaBGT) binding reaches equilibrium within 4 h and is saturable with a K(d) value of 4.

View Article and Find Full Text PDF

As a novel approach to drug discovery involving neuronal nicotinic acetylcholine receptors (nAChRs), our laboratory targeted nonagonist binding sites (i.e., noncompetitive binding sites, negative allosteric binding sites) located on nAChRs.

View Article and Find Full Text PDF

Several pathological conditions involve alterations in expression of neuronal nicotinic acetylcholine receptors (nAChRs). Although some studies have addressed processes involved with muscle nAChR expression, knowledge of the regulation of neuronal nAChRs is particularly sparse. The following studies were designed to investigate cellular mechanisms involved with expression of neuronal alpha3beta4* nAChRs.

View Article and Find Full Text PDF

The development of novel agents for the differentiation of neuronal nicotinic acetylcholine receptors (nAChRs) is important for the treatment of a variety of pathological conditions. We have prepared and evaluated a number of simpler analogues of the norditerpeniod alkaloid methyllycaconitine (MLA) in an effort to understand molecular determinants of nAChR*small molecule interactions. We have previously reported the synthesis and evaluation of a series of ring E analogues of MLA.

View Article and Find Full Text PDF
Article Synopsis
  • The paper presents a new renormalization-group method tailored for nonequilibrium systems, specifically looking at a one-dimensional gas with open boundaries.
  • It defines three key parameters influencing particle dynamics: alpha (inflow probability), beta (outflow probability), and p (jumping right probability).
  • The study identifies a critical point (alpha(c)=beta(c)=1/2) that matches exact values, and calculates a critical exponent (nu=2.71), though this slightly differs from the exact value (nu=2.00).
View Article and Find Full Text PDF

Many pathological conditions involve alterations in expression of nicotinic acetylcholine receptors (nAChRs). The following studies were designed to investigate cellular mechanisms involved with expression and turnover of alpha3beta4* nAChRs. These studies support constitutive turnover of adrenal alpha3beta4* nAChRs and the use of cultured adrenal chromaffin cells to study nAChR regulation.

View Article and Find Full Text PDF

In these studies, [3H]epibatidine is used as the radioligand to characterize nicotinic acetylcholine receptors (nAChRs) from bovine adrenal medulla. Specific binding reaches equilibrium within 30 min, and is saturable with a Kd value of 0.5 nM.

View Article and Find Full Text PDF

The development of new agents that selectively interact with subtypes of neuronal nicotinic receptors (nAChRs) is of primary importance for the study of physiological processes and pathophysiological conditions involving these receptors. Our laboratory has evidence that simple ring E analogues of methyllycaconitine (MLA) act as antagonists to bovine adrenal alpha3beta4* nAChRs. The following studies were designed to characterize the concentration-response effects of several ring E analogues of MLA in order to assess structural requirements involved with their inhibitory activity on bovine adrenal alpha3beta4* nAChRs.

View Article and Find Full Text PDF