Comparison of molecular detection methods for pertussis in children during a state-wide outbreak.

A state-wide pertussis outbreak occurred in Washington during the winter-spring months of 2012, concurrent with respiratory viral season. We compared performance characteristics of a laboratory-developed pertussis PCR (LD-PCR for Bordetella pertussis, Bordetella parapertussis, and Bordetella holmesii) and rapid multiplex PCR (RM-PCR) for respiratory viruses (FilmArray™, BioFire, B. pertussis data unblinded following FDA approval post outbreak). We analyzed three cohorts of patients using physician testing orders as a proxy for clinical suspicion for pertussis or respiratory viruses: Cohort 1, tested by LD-PCR for pertussis pathogens only by nasopharyngeal swab; Cohort 2, by RM-PCR for respiratory viruses only by mid-nasal turbinate swab; and Cohort 3, by both methods. B. pertussis was detected in a total of 25 of the 490 patients in Cohort 3 in which LD-PCR detected 20/25 (80 %) cases and the RM-PCR detected 24/25 (96 %; p = 0.2). Pertussis pathogens were detected in 21/584 (3.6 %) of samples from Cohort 1 where clinicians had a relatively strong suspicion for pertussis. In contrast, B. pertussis was detected in only 4/3071 (0.1 %) specimens from Cohort 2 where suspicion for pertussis was lower (p < 0.001 for comparison with Cohort 1). In summary, the two laboratory methods were comparable for the detection of B. pertussis.

Human herpesvirus 6B reactivation and delirium are frequent and associated events after cord blood transplantation.

Human herpesvirus 6B (HHV-6B) frequently reactivates after cord blood transplantation (CBT). We previously reported an association between HHV-6B reactivation and delirium after hematopoietic cell transplantation. In this prospective study, 35 CBT recipients underwent twice-weekly plasma PCR testing for HHV-6 and thrice-weekly delirium assessment until day 84. There was a quantitative association between HHV-6B reactivation and delirium in univariable (odds ratio, 2.88; 95% confidence interval (CI), 0.97-8.59) and bivariable models. In addition, intensified prophylaxis with high-dose valacyclovir mitigated HHV-6B reactivation (adjusted hazard ratio, 0.39; 95% CI, 0.14-1.08). Larger trials are needed to explore the utility of HHV-6B prophylaxis after CBT.

Effects of endothelin receptor antagonists on the plasma immunoreactive endothelin-1 level.

Endothelin (ET) receptor antagonists may be beneficial for treating several medical conditions. Human trials with various ET receptor antagonists show that these antagonists elevate the plasma immunoreactive endothelin-1 (irET-1) level, and different classes of antagonists seem to affect the plasma ET-1 level differently. In this report, we study effects of ETA-selective, ETB-selective, and nonselective receptor antagonists on the plasma irET-1 level in the rat, and also compare available clinical data. The plasma irET-1 level was increased by five- and ten-fold after rats were treated with A-192621, an ETB-selective antagonist with Ki values for ETA and ETB at 5600 and 8.8 nM, for 3 days at 30 and 100 mg/kg/day via food. The plasma irET-1 level was increased by 1.8 and 2.4-fold when rats were treated with A-216546, an antagonist with Ki values for ETA and ETB at 0.46 and 13 000 nM, at 10 and 50 mg/kg/day via food for 7 days. As a comparison, the plasma irET-1 level was increased by > 24-fold when rats were treated with A-182086, a nonselective antagonist with Ki values for ETA and ETB at 0.2 and 1.2 nM, at 100 mg/kg/day via food for 9 days. In humans, blockade of ETA by ABT-627 did not result in an elevation in irET-1 until after 7 days of treatment. The results are consistent with the hypothesis that the ETB-receptor is the clearance receptor for ET-1. Our data also suggest that the modest effect of ETA antagonists on the plasma irET-1 level is probably a result of the upregulation of the ET-1 gene via a feedback mechanism.

Pharmacology of A-216546: a highly selective antagonist for endothelin ET(A) receptor.

Endothelins, 21-amino acid peptides involved in the pathogenesis of various diseases, bind to endothelin ET(A) and ET(B) receptors to initiate their effects. Here, we characterize the pharmacology of A-216546 ([2S-(2,2-dimethylpentyl)-4S-(7-methoxy-1,3-benzodioxol-5-yl )-1-(N,N-di(n-butyl) aminocarbonylmethyl)-pyrrolidine-3R-carboxylic acid), a potent antagonist with > 25,000-fold selectivity for the endothelin ET(A) receptor. A-216546 inhibited [125I]endothelin-1 binding to cloned human endothelin ET(A) and ET(B) receptors competitively with Ki of 0.46 and 13,000 nM, and blocked endothelin-1-induced arachidonic acid release and phosphatidylinositol hydrolysis with IC50 of 0.59 and 3 nM, respectively. In isolated vessels, A-216546 inhibited endothelin ET(A) receptor-mediated endothelin-1-induced vasoconstriction, and endothelin ET(B) receptor-mediated sarafotoxin 6c-induced vasoconstriction with pA2 of 8.29 and 4.57, respectively. A-216546 was orally available in rat, dog and monkey. In vivo, A-216546 dose-dependently blocked endothelin-1-induced pressor response in conscious rats. Maximal inhibition remained constant for at least 8 h after dosing. In conclusion, A-216546 is a potent, highly endothelin ET(A) receptor-selective and orally available antagonist, and will be useful for treating endothelin-1-mediated diseases.

Pharmacological characterization of A-127722: an orally active and highly potent ETA-selective receptor antagonist.

Endothelins (ET) are potent vasoactive peptides implicated in the pathogenesis of a number of vascular diseases. The effects of ET on mammalian organs and cells are initiated by binding to ETA or ETB receptors. In this report, we document the pharmacology of A-127722, a novel ETA-selective receptor antagonist. A-127722 inhibits [125I]ET-1 binding to cloned human ETA and ETB receptors competitively with Ki values of 69 pM and 139 nM, respectively. A-127722 exhibits a dose-dependent inhibition of ET-1-induced arachidonic acid release in human pericardium smooth muscle cells with a pA2 value of 10.5 and inhibits ET-1-induced vasoconstriction in isolated rat aorta with a pA2 value of 9.2. In vivo, A-127722 dose-dependently blocks the pressor response to ET-1 (0.3 nmol/kg i.v.) in conscious rats. Statistically significant (P < .05) antagonism is seen at doses greater than 0.1 mg/kg p.o. Maximal inhibition, at 10 mg/kg, remains constant for at least 8 hr after dosing. No effect is seen on the ETB-mediated transient vasodepressor effect of exogenous ET-1. In conclusion, A-127722 is ETA-selective, orally bioavailable and efficacious for inhibiting the effects of ET in the rat, and A-127722 is the most potent ET receptor antagonist yet reported.

Cardiovascular effects of orally administered ABBOTT-81988, an angiotensin II antagonist, in conscious spontaneously hypertensive rats.

ABBOTT-81988 (A-81988), 2-(N-propyl-N[(2'-[1H-tetrazol-5-yl]biphenyl- 4yl)methyl] amino) pyridine-3-carboxylic acid, a nonpeptide angiotensin II (AII) antagonist was studied in the conscious spontaneously hypertensive rate (SHR) (male, 18 to 21 weeks) for cardiovascular effects of oral administration. Oral A-81988 at 0.3 to 3 mg/kg produced a dose-related 10 to 29% decrease in mean arterial pressure (MAP) in SHR (control, 161 to 177 mm Hg; n = 19) for 12 to 24 h without changing heart rate. Oral A-81988 at 3 mg/kg daily maintained MAP in SHR at normotensive levels (97 to 120 mm Hg) during a 5-day protocol with no rebound hypertension at termination of treatment. There was an increase in plasma renin activity in nanograms AI/milliliter/hour in SHR treated with A-81988 (32 +/- 3, n = 6 v 5 +/- 2, n = 6 for vehicle) during its antihypertensive action. The oral potency of A-81988 was enhanced about 10-fold in furosemide-treated SHR. The pressor response to AII was inhibited selectively in SHR even after an 8-day treatment with A-81988 (approximately 3 mg/kg/day orally). Total peripheral resistance was lowered and cardiac output unchanged in SHR administered A-81988 (3 mg/kg/day orally for 2 days). A-81988 (3 mg/kg orally) did not cause orthostatic hypotension in SHR.(ABSTRACT TRUNCATED AT 250 WORDS)

Endothelin ETA receptor antagonist reduces myocardial infarction induced by coronary artery occlusion and reperfusion in the rat.

The effect of the endothelin ETA receptor antagonist FR 139317 on myocardial infarction was studied in the rat. Under anesthesia, rats were subjected to 30 min of left main coronary artery occlusion and 3 h of reperfusion. FR 139317 (15, 35 and 70 mg/kg total dose) was continuously infused i.v. starting approximately 30 min before coronary artery occlusion and continuing throughout occlusion and reperfusion. The area at risk (AAR), determined using phthalocyanine dye, was in the range of 48-63% of the left ventricle (LV). The infarct zone (IZ) was evaluated by tetrazolium staining defect and its size was calculated as a percent of AAR. The IZ/AAR (%) was significantly reduced in rats treated with FR 139137 (15 mg/kg: 20 +/- 4%, n = 6; 35 mg/kg: 24 +/- 2%, n = 6, and 70 mg/kg: 26 +/- 4%, n = 8) compared to the vehicle group (36 +/- 2%, n = 22) (p < 0.05). When rats were treated beginning just prior to reperfusion, FR 139317 (35 mg/kg) also produced a significant reduction in infarct size (IZ/AAR: 22 +/- 1% for FR 139317, n = 6 vs. 39 +/- 6% for vehicle, n = 6, p < 0.05). These data suggest an important role for the ETA receptor-mediated effects of ET in the pathophysiology of myocardial infarction. ETA receptor antagonism may provide a novel therapeutic approach for cardioprotection in myocardial infarction.

Effects of nontransmural ischemia on inner and outer wall thickening in the canine left ventricle.

The effect of ischemic subendocardial dysfunction on contractile function in the normally perfused subepicardium remains controversial. Accordingly, regional wall thickening (WT) was measured directly in the left ventricle of 10 open-chest dogs using epicardial echocardiography. Two silk sutures, used as echocardiographic targets, were inserted beneath the transducer to a depth of 25.0 +/- 0.7% (subepicardium) and 48.0 +/- 2.7% (midmyocardium) of transmural thickness. A hydraulic cuff, placed around the left anterior descending coronary artery (LAD) was then inflated slowly until transmural WT was reduced to 62 +/- 2% of baseline. Myocardial blood flow (MBF) was not significantly altered in the subepicardial third of the wall; however, flow to the midwall and subendocardial thirds decreased by 39% (p less than 0.001) and 50% (p less than 0.001), respectively. Nontransmural ischemia produced a small but significant decrease in epicardial WT (baseline = 0.77 +/- 0.08 mm, ischemia = 0.69 +/- 0.08 mm; p less than 0.05) and substantially larger decreases in midwall (baseline = 1.66 +/- 0.14 mm, ischemia = 1.03 +/- 0.09 mm; p less than 0.001) and subendocardial WT (baseline = 3.39 +/- 0.34 mm, ischemia = 2.10 +/- 0.26 mm; p less than 0.001). The degree of regional dysfunction was linearly correlated with tissue depth (r = 0.88, p less than 0.001). Thus the degree of dysfunction produced by nontransmural ischemia increased progressively from the subepicardium to the subendocardium, paralleling the pattern of perfusion. We conclude that perfusion, rather than transmural tethering, largely determines subepicardial function in the setting of nontransmural ischemia.

Serum zinc levels in patients with basal-cell carcinoma.

Basal-cell carcinoma is a malignant epithelial neoplasm that arises from the germinative cells of the epidermis and its appendages. Various causative factors have been implicated in its pathogenesis. In recent years, it has become increasingly apparent that alterations in serum zinc concentration may relate to neoplastic diseases. The objective of this study was to determine whether or not a relationship exists between abnormal serum zinc levels and basal-cell carcinomas. The data indicate that a statistically significant elevation in mean serum zinc levels is associated with this neoplasm. This may, however, not be of clinical significance because of variation in environmental or statistical sampling factors.