Salivary protein changes in response to acute stress in medical residents performing advanced clinical simulations: a pilot proteomics study.

CONTEXT: Quantitative changes of salivary proteins due to acute stress were detected. OBJECTIVE: To explore protein markers of stress in saliva of eight medical residents who performed emergency medicine simulations. MATERIALS AND METHODS: Saliva was collected before the simulations, after the simulations, and following morning upon waking. Proteins were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), identified by mass spectrometry (MS), and relatively quantified by densitometry. RESULTS: Salivary alpha-amylase and S-type cystatins significantly increased, while the ∼26 kDa and low-molecular weight (MW) (<10 kDa) SDS-PAGE bands exhibited changes after stress. DISCUSSION AND CONCLUSION: Alpha-amylase and cystatins are potential salivary markers of acute stress, but further validation should be performed using larger sample populations.

Reliability of corticomotor excitability in leg and thigh musculature at 14 and 28 days.

CONTEXT: Alterations in corticomotor excitability are observed in a variety of patient populations, including the musculature surrounding the knee and ankle after joint injury. Active motor threshold (AMT) and motor-evoked-potential (MEP) amplitudes elicited through transcranial magnetic stimulation (TMS) are outcome measures used to assess corticomotor excitability and have been deemed reliable in upper-extremity musculature. However, there are few studies assessing the reliability of TMS measures in lower-extremity musculature. OBJECTIVE: To determine the intersession reliability of AMT and MEP amplitudes over 14 and 28 d in the quadriceps and fibularis longus (FL). DESIGN: Descriptive laboratory study. SETTING: University laboratory PARTICIPANTS: 20 able-bodied volunteers (10 men, 10 women; 22.35 ± 2.3 y, 1.71 ± 0.11 m, 73.61 ± 16.77 kg). MAIN OUTCOME MEASURES: AMT and MEP amplitudes were evaluated at 95%, 100%, 105%, 110%, 120%, 130%, and 140% of AMT in the dominant and nondominant quadriceps and FL. Interclass correlation coefficients (ICCs) were used to assess reliability for absolute agreement and internal consistency between baseline and 2 follow-up sessions at 14 and 28 d postbaseline. Each ICC was fit with the best-fit straight line or parabola to smooth out noise in the observations and best determine if a pattern existed in determining the most reliable MEP value. RESULTS: All muscles yielded strong ICCs between baseline and both time points for AMT. MEPs in both the quadriceps and FL produced varying degrees of reliability, with the greatest reliability demonstrated on day 28 at 130% and 140% of AMT in the quadriceps and FL, respectively. The dominant FL muscle showed a significant pattern; as TMS intensity increased, MEP reliability increased. CONCLUSION: TMS can be used to reliably identify corticomotor alterations after therapeutic interventions, as well as monitor disease progression.

Developmental selenomethionine and methylmercury exposures affect zebrafish learning.

Methylmercury (MeHg) is a ubiquitous environmental pollutant and has been shown to affect learning in vertebrates following relatively low exposures. Zebrafish were used to model long-term learning deficits after developmental MeHg exposure. Selenomethionine (SeMet) co-exposure was used to evaluate its role in neuroprotection. Embryos were exposed from 2 to 24h post fertilization to (1) MeHg without SeMet, (2) SeMet without MeHg and (3) in combination of MeHg and SeMet. In case (1), the levels of MeHg were 0.00, 0.01, 0.03, 0.06, 0.10, and 0.30 microM. In case (2), the levels of SeMet were 0.00. 0.03, 0.06, 0.10, and 0.30 microM. In case (3), co-exposure levels of (MeHg, SeMet) were (0.03, 0.03), (0.03, 0.06), (0.03, 0.10), (0.03, 0.30), (0.10, 0.03), (0.10, 0.06), (0.10, 0.10), and (0.10, 0.30) microM. Learning functions were tested in individual adults, 4 months after developmental exposure using a spatial alternation paradigm with food delivery on alternating sides of the aquarium. Low levels of MeHg (<0.1 microM) exposure delayed learning in treated fish; fish exposed to higher MeHg levels were unable to learn the task; SeMet co-exposure did not prevent this deficit. These data are consistent with findings in laboratory rodents. The dorsal and lateral telencephalon are the primary brain regions in fish involved in spatial learning and memory. Adult telencephalon cell body density decreased significantly at all MeHg exposures >0.01 microM MeHg. SeMet co-exposure ameliorated but did not prevent changes in telencephalon cell body density. In summary, MeHg affected both learning and brain structure, but SeMet only partially reversed the latter.

A synergism model for PPARalpha and PXR agonist effects on HDL-cholesterol and apoA1.

Synergism between gemfibrozil and CDD 3540, drugs used to elevate mouse serum HDL cholesterol and apoprotein A1, is modeled using nonlinear response surface techniques. This approach employs a common simple pharmacological model to describe the dose-response function. Its parameters are modeled as functions of drug mixture fractions using models borrowed from mixture experiment analysis methods. This study advances previous in vitro synergy studies in three key areas. First, it was in vivo, with the associated additional variability. Second, the sample size was much smaller than in previous studies. Finally, this was the first specially designed study with this type of statistical analysis in mind. The design consisted of replicated observations along each of five rays at combination amounts chosen employing the principles of D-optimality. Also, the observed in vivo synergism of the combined use of these drugs, elevated levels of HDL-C and apoA1, and the experimental results and statistical models may provide important clues regarding the biological mechanisms of action of the two compounds.

Modeling the combination of amphotericin B, micafungin, and nikkomycin Z against Aspergillus fumigatus in vitro using a novel response surface paradigm.

Response surface methods for the study of multiple-agent interaction allow one to model all of the information present in full concentration-effect data sets and to visualize and quantify local regions of synergy, additivity, and antagonism. In randomized wells of 96-well plates, Aspergillus fumigatus was exposed to various combinations of amphotericin B, micafungin, and nikkomycin Z. The experimental design was comprised of 91 different fixed-ratio mixtures, all performed in quintuplicate. After 24 h of drug exposure, drug effect on fungal viability was assessed using the tetrazolium salt 2,3-bis {2-methoxy-4-nitro-5-[(sulfenylamino) carbonyl]-2H-tetrazolium-hydroxide} (XTT) assay. First, we modeled each fixed-ratio combination alone using the four-parameter Hill concentration-effect model. Then, we modeled each parameter, including the 50% inhibitory concentration (IC(50)) effect, versus the proportion of each agent using constrained polynomials. Finally, we modeled the three-agent response surface overall. The overall four-dimensional response surface was complex, but it can be explained in detail both analytically and graphically. The grand model that fit the best included complex polynomial equations for the slope parameter m and the combination index (equivalent to the IC(50) for a fixed-ratio concentration, but with concentrations normalized by the respective IC(50)s of the drugs alone). There was a large region of synergy, mostly at the nikkomycin Z/micafungin edge of the ternary plots for equal normalized proportions of each drug and extending into the center of the plots. Applying this response surface method to a huge data set for a three-antifungal-agent combination is novel. This new paradigm has the potential to significantly advance the field of combination antifungal pharmacology.

Verapamil, but not probenecid, co-administration can convert desloratadine to a sedating antihistamine in mice.

The possibility that non-sedating antihistamines could elicit sedation in mice due to drug-induced inhibition of brain PgP was evaluated by measuring the ability of desloratadine alone or in combination with verapamil to cause ataxia in mice. Also, the concentrations of desloratadine in plasma and in brain homogenates were measured by liquid chromatography-mass spectrometry. Relative to methylcellulose (control) treatment, verapamil plus desloratadine decreased rotarod performance of mice. Plasma concentrations of desloratadine appeared comparable in the mice treated with either desloratadine or verapamil plus desloratadine, however the rate of decline of desloratadine from brain tissue was slower in mice treated with verapamil plus desloratadine compared to mice treated with desloratadine only. These data suggest that inhibition of brain PgP can convert desloratadine to a sedating antihistamine in mice.

A new nonlinear mixture response surface paradigm for the study of synergism: a three drug example.

A flexible approach to response surface modeling for the study of the joint action of three active anticancer agents is used to model a complex pattern of synergism, additivity and antagonism in an in vitro cell growth assay. The method for determining a useful nonlinear response surface model depends upon a series of steps using appropriate scaling of drug concentrations and effects, raw data modeling, and hierarchical parameter modeling. The method is applied to a very large in vitro study of the combined effect of Trimetrexate (TMQ), LY309887 (LY), and Tomudex (TDX) on inhibition of cancer cell growth. The base model employed for modeling dose-response effect is the four parameter Hill equation [1]. In the hierarchical aspect of the final model, the base Hill model is treated as a function of the total amount of the three drug mixture and the Hill parameters, background B, dose for 50% effect D50, and slope m, are understood as functions of the three drug fractions. The parameters are modeled using the canonical mixture polynomials from the mixture experiment methodologies introduced by Scheff [2]. We label the model generated a Nonlinear Mixture Amount model with control observations, or zero amounts, an "NLMAZ" model. This modeling paradigm provides for the first time an effective statistical approach to modeling complex patterns of local synergism, additivity, and antagonism in the same data set, the possibility of including additional experimental components beyond those in the mixture, and the capability of modeling three or more drugs.

Provision of drug information to patients by pharmacists: the impact of the Omnibus Budget Reconciliation Act of 1990 a decade later.

Drug-related illness in the United States factors substantially in health care costs, although often these illnesses and their attendant costs are preventable. One strategy for minimizing adverse drug reactions is to provide drug information to consumers in the form of prescription counseling at pharmacies. The Omnibus Budget Reconciliation Act of 1990 (OBRA 1990) contained provisions for mandating such counseling to Medicaid patients. OBRA 1990 was implemented in 1993, but most states acted quickly to extend counseling services to all patients receiving prescription drugs. We looked at the extent and quality of prescription counseling available in community pharmacies 1 decade after OBRA 1990 was written. We evaluated the counseling services afforded at large chain pharmacies, independent community pharmacies, and on-line pharmacies for a hydrochlorothiazide prescription. We found that most (69%) pharmacies offered to provide prescription counseling service, and that average counseling index scores, a measure of the quality or extent of information provided as determined by a Rasch analysis, were generally satisfactory. Our observations based on a single prescription for hydrochlorothiazide, along with other studies, suggest that there is a positive upward trend in the number of pharmacies providing prescription drug information, and that the extent of information provided suggests that the objectives of OBRA 1990 and related legislation to reduce ADRs are being fundamentally satisfied.

Herbal and nonherbal alternative medicine use in Northwest Ohio.

OBJECTIVE: To determine the prevalence and characteristics of herbal and nonherbal alternative medicine use among adults living in northwest Ohio. DESIGN: Cross-sectional survey. SETTING: Three grocery store intercepts in northwest Ohio. SUBJECTS: A consecutive sample of 326 English-speaking persons > or =18 years old. METHODS: A 26-item survey self-administered to participants over a 6-month period. OUTCOME MEASURES: Prevalence of herbal remedy use. RESULTS: Forty percent of respondents have used an herbal remedy during the last 12 months. The average number of herbs used was 2.3 per person. Herbal remedy use was not associated with specific sociodemographic variables. Desire to improve general health was the most common reason for use of an herbal remedy (16%). Herbal users cited "herbals are natural" as the most common benefit. Magazines (17%), health food stores (16%), and friends (14%) were the most common sources of herbal remedy information. Only 50% of the population informed their physician of such use. Forty-one percent used an herbal remedy sometimes to always to self-treat before seeking medical care from a physician. Fifteen percent of adults treated their children with herbs. Nearly all (86%) respondents believed the herb was helpful or very helpful. CONCLUSIONS: A significant number of the adults surveyed in the Toledo metropolitan area commonly used complementary and alternative medicine (CAM). There were no independent factors associated with herbal remedy use. It is important for healthcare providers to acknowledge this growing trend of CAM therapy use and begin to incorporate open discussion about CAM into the patient-provider relationship.