Improved auscultation skills in paramedic students using a modified stethoscope.

Background: The Ventriloscope® (Lecat's SimplySim, Tallmadge, OH) is a modified stethoscope used as a simulation training device for auscultation.

Objective: To test the effectiveness of the Ventriloscope as a training device in teaching heart and lung auscultatory findings to paramedic students.

Methods: A prospective, single-hospital study conducted in a paramedic-teaching program.

Discovery of potent hepatitis C virus NS5A inhibitors with dimeric structures.

The exceptional in vitro potency of the hepatitis C virus (HCV) NS5A inhibitor BMS-790052 has translated into an in vivo effect in proof-of-concept clinical trials. Although the 50% effective concentration (EC(50)) of the initial lead, the thiazolidinone BMS-824, was ~10 nM in the replicon assay, it underwent transformation to other inhibitory species after incubation in cell culture medium. The biological profile of BMS-824, including the EC(50), the drug concentration required to reduce cell growth by 50% (CC(50)), and the resistance profile, however, remained unchanged, triggering an investigation to identify the biologically active species.

The synthesis and evaluation of a novel class of (E)-3-(1-cyclohexyl-1H-pyrazol-3-yl)-2-methylacrylic acid hepatitis C virus polymerase NS5B inhibitors.

Herein we report the identification and evaluation of a novel series of (E)-3-(1-cyclohexyl-1H-pyrazol-3-yl)-2-methylacrylic acid derivatives identified from a deannulation study performed on the reported benzimidazole NS5B inhibitor, 1. This resulted in the identification of (E)-3-(2-(4-((4'-cyano-4-(4-hydroxypiperidine-1-carbonyl)biphenyl-2-yl)methoxy)phenyl)-1-cyclohexyl-1H-imidazol-4-yl)-2-methylacrylic acid (11) as a potent inhibitor of NS5B. Potential pathways for the further optimization of this series are suggested.

Syntheses and initial evaluation of a series of indolo-fused heterocyclic inhibitors of the polymerase enzyme (NS5B) of the hepatitis C virus.

Herein, we present initial SAR studies on a series of bridged 2-arylindole-based NS5B inhibitors. The introduction of bridging elements between the indole N1 and the ortho-position of the 2-aryl moiety resulted in conformationally constrained heterocycles that possess multiple additional vectors for further exploration. The binding mode and pharmacokinetic (PK) properties of select examples, including: 13-cyclohexyl-6-oxo-6,7-dihydro-5H-indolo[2,1-d][1,4]benzodiazepine-10-carboxylic acid (7) (IC(50)=0.

Inhibitors of HCV NS5A: From Iminothiazolidinones to Symmetrical Stilbenes.

The iminothiazolidinone BMS-858 (2) was identified as a specific inhibitor of HCV replication in a genotype 1b replicon assay via a high-throughput screening campaign. A more potent analogue, BMS-824 (18), was used in resistance mapping studies, which revealed that inhibitory activity was related to disrupting the function of the HCV nonstructural protein 5A. Despite the development of coherent and interpretable SAR, it was subsequently discovered that in DMSO 18 underwent an oxidation and structural rearrangement to afford the thiohydantoin 47, a compound with reduced HCV inhibitory activity.

Identification of hepatitis C virus NS5A inhibitors.

Using a cell-based replicon screen, we identified a class of compounds with a thiazolidinone core structure as inhibitors of hepatitis C virus (HCV) replication. The concentration of one such compound, BMS-824, that resulted in a 50% inhibition of HCV replicon replication was approximately 5 nM, with a therapeutic index of >10,000. The compound showed good specificity for HCV, as it was not active against several other RNA and DNA viruses.

3-[(5-Chloro-2-hydroxyphenyl)methyl]-5-[4-(trifluoromethyl)phenyl ]-1,3,4-oxadiazol-2(3H)-one, BMS-191011: opener of large-conductance Ca(2+)-activated potassium (maxi-K) channels, identification, solubility, and SAR.

Compound 8a (BMS-191011), an opener of the cloned large-conductance, Ca2+-activated potassium (maxi-K) channel, demonstrated efficacy in in vivo stroke models, which led to its nomination as a candidate for clinical evaluation. Its maxi-K channel opening properties were consistent with its structural topology, being derived by combining elements from other known maxi-K openers. However, 8a suffered from poor aqueous solubility, which complicated elucidation of SAR during in vitro evaluation.

Dihydropyridine neuropeptide Y Y1 receptor antagonists 2. bioisosteric urea replacements.

Structure-activity studies around the urea linkage in BMS-193885 (4a) identified the cyanoguanidine moiety as an effective urea replacement in a series of dihydropyridine NPY Y(1) receptor antagonists. In comparison to urea 4a (K(i)=3.3 nM), cyanoguanidine 20 (BMS-205749) displayed similar binding potency at the Y(1) receptor (K(i)=5.

Novel openers of Ca2+-dependent large-conductance potassium channels: symmetrical pharmacophore and electrophysiological evaluation of bisphenols.

Electrophysiological evaluation of symmetrical analogues of the known maxi-K opener NS-004 (1) led to the discovery of bisphenols 2a, 3a and 4a as openers of cloned maxi-K channels expressed in oocytes.

4,5-diphenyltriazol-3-ones: openers of large-conductance Ca(2+)-activated potassium (maxi-K) channels.

A series of diphenyl-substituted heterocycles were synthesized and evaluated by electrophysiological techniques as openers of the cloned mammalian large-conductance, Ca(2+)-activated potassium (maxi-K) channel. The series was designed from deannulation of known benzimidazolone maxi-K opener NS-004 (2) thereby providing an effective template for obtaining structure-activity-related information. The triazolone ring system was the most studied wherein 4,5-diphenyltriazol-3-one 6d (maxi-K = 158%) was identified as the optimal maxi-K channel opener.

Dihydropyridine neuropeptide Y Y(1) receptor antagonists.

Dihydropyridine 5a was found to be an inhibitor of neuropeptide Y(1) binding in a high throughput (125)I-PYY screening assay. Structure-activity studies around certain portions of the dihydropyridine chemotype identified BMS-193885 (6e) as a potent and selective Y(1) receptor antagonist. In a forskolin-stimulated c-AMP production assay using CHO cells expressing the human Y(1) receptor, 6e demonstrated full functional antagonism (K(b)=4.