Trace-metal contamination in the glacierized Rio Santa watershed, Peru.

The objective of this research is to characterize the variability of trace metals in the Rio Santa watershed based on synoptic sampling applied at a large scale. To that end, we propose a combination of methods based on the collection of water, suspended sediments, and riverbed sediments at different points of the watershed within a very limited period. Forty points within the Rio Santa watershed were sampled between June 21 and July 8, 2013.

Access to care for children with symptoms of sleep disordered breathing.

Objectives: To determine if children with sleep disordered breathing who have Medicaid insurance encounter more difficulty accessing an otolaryngologist than those with private insurance.

Design: Retrospective study.

Setting: Urban tertiary care pediatric hospital.

Synchronous airway lesions in children younger than age 3 years undergoing adenotonsillectomy.

Objective: Determine the prevalence of synchronous airway lesions (SALs) in children younger than age 3 years undergoing adenoidectomy or adenotonsillectomy for sleep-disordered breathing (SDB) at Children’s Memorial Hospital.

Design: Case series with chart review.

Setting: Tertiary care pediatric hospital.

MRI of orbital cellulitis and orbital abscess: the role of diffusion-weighted imaging.

Objective: Our aims were to describe the role of diffusion-weighted imaging (DWI) in detecting abscess as a complication of orbital cellulitis and to assess whether abscess can be diagnosed with a combination of conventional unenhanced sequences and whole-brain DWI with parallel acquisition. Nine cases of orbital cellulitis imaged with MRI were retrospectively reviewed, including six cases with pyogenic abscess.

Conclusion: In this preliminary study, DWI improved diagnostic confidence in nearly all cases of orbital abscess when used in conjunction with contrast-enhanced imaging.

Enantiomeric propanolamines as selective N-methyl-D-aspartate 2B receptor antagonists.

Enantiomeric propanolamines have been identified as a new class of NR2B-selective NMDA receptor antagonists. The most effective agents are biaryl structures, synthesized in six steps with overall yields ranging from 11-64%. The compounds are potent and selective inhibitors of NR2B-containing recombinant NMDA receptors with IC 50 values between 30-100 nM.

Subunit-specific mechanisms and proton sensitivity of NMDA receptor channel block.

We have compared the potencies of structurally distinct channel blockers at recombinant NR1/NR2A, NR1/NR2B, NR1/NR2C and NR1/NR2D receptors. The IC50 values varied with stereochemistry and subunit composition, suggesting that it may be possible to design subunit-selective channel blockers. For dizocilpine (MK-801), the differential potency of MK-801 stereoisomers determined at recombinant NMDA receptors was confirmed at native receptors in vitro and in vivo.

Postoperative pain management after craniotomy: evaluation and cost analysis.

Objective: Patients undergoing craniotomies have traditionally received opiates for the management of their postoperative pain. The use of narcotic pain medications can be costly, can decrease early walking, can lengthen hospital stay, and can alter a patient's neurological examination results. The use of alternative pain medications such as cyclooxygenase-2 (COX-2) inhibitors may benefit patients by resolving many of these issues.

Serum protein profile analysis in patients with head and neck squamous cell carcinoma.

Objectives: To analyze surface-enhanced laser desorption and ionization time-of-flight mass spectrometry (SELDI-TOF-MS) protein profiles of patients with head and neck squamous cell carcinoma (HNSCC) and healthy controls and to determine the sensitivity and specificity of SELDI assay for HNSCC detection before and after treatment.

Design: Proteomic analysis and comparison of serum samples.

Setting: Tertiary care academic medical center.

Molecular determinants of proton-sensitive N-methyl-D-aspartate receptor gating.

Extracellular protons inhibit N-methyl-D-aspartate (NMDA) receptors with an IC50 value in the physiological pH range. To identify the molecular determinants of proton sensitivity, we used scanning mutagenesis of the NR1 subunit to search for residues that control proton inhibition of NMDA receptors. Homology modeling of the extracellular domains suggested that residues at which mutations perturbed pH sensitivity were localized in discrete regions.

Interactions between opioids and cocaine on locomotor activity in rats: influence of an opioid's relative efficacy at the mu receptor.

Rationale: Cocaine and mu opioid agonists increase central dopamine concentrations and produce robust interactions at both neurochemical and behavioral levels. Although the interactions between cocaine and high-efficacy mu opioids have been well characterized, the interactions between cocaine and lower efficacy opioids have not been as extensively examined.

Objective: The purpose of this study was to examine the interactions between cocaine and opioids possessing a range of relative efficacy at the mu receptor.

Age-related differences in sensitivity to the antinociceptive effects of kappa opioids in adult male rats.

Rationale: Significant differences in the potency and effectiveness of opioid analgesics have been reported in subject populations differing in age. Although the relationship between aging and sensitivity to the antinociceptive effects of mu opioids has been examined extensively, relatively few studies have examined this relationship in kappa opioids.

Objectives: The purpose of the present investigation was to examine the antinociceptive effects of selected kappa and mixed-action opioids in young (3 months) and aged (21 months) male rats.