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Biomedical subjects

W A Parker

Publications and source records attributed to W A Parker.

At least 19 recordsLinked to original sources
PubMed1992

HLA-DR4-associated nonresponsiveness to mountain-cedar allergen.

We did human lymphocyte antigen (HLA)-DR and DQ typing on 37 subjects with mountain-cedar (MC) pollinosis as defined by history and a positive skin test. Of these 37 subjects, 31 were subdivided into 18 subjects with a single positive skin test (SPST) and 13 subjects with multiple positive skin tests (MPSTs). We also typed 51 subjects without MC sensitivity or atopy as defined by history and negative skin tests to a battery of aeroallergens. We also typed 116 subjects in whom MC sensitivity had not been determined. Total IgE, Mc-specific immunoglobulin E (sIgE), and MC-sIgE binding bands by immunoblot were also determined on the subjects with SPSTs and MPSTs. No significant differences were found between the subjects with SPSTs and MPSTs for HLA type, total IgE, MC sIgE, or bands bound by MC sIgE by immunoblot. There was a strong negative relationship between HLA-DR4 and subjects with MC pollinosis; chi-square, 14.857; p = 0.0096; and odds ratio, 0.139. These findings suggest that there is no difference in genetic immunoregulation between subjects with SPSTs and MPSTs but that the presence of the DR4 gene product is associated with a decreased risk of an IgE response to MC and protection from MC pollenosis.

Allergens↗
PubMed1991

The ACT as a predictor of success on the National Board Dental Hygiene Examination.

The purpose of this study was to determine the predictive ability of the American College Test (ACT) with respect to success (achieving a passing score of 75 or higher) on the National Board Dental Hygiene Examination (NBDHE). Records of 209 dental hygiene graduates from the 1975-1984 baccalaureate degree program at the Baylor College of Dentistry were used in this retrospective study. Descriptive statistics, median (MD), mean, standard deviation, maximum/minimum values, and 95% confidence intervals were determined for each year for the ACT and NBDHE. Pearson product moment correlation coefficients (Pearson r), coefficients of determination (r2), t-ratios and p-values were calculated. The ACT scores were found to be a weak to moderate predictor of success (75+ passing score) on the NBDHE in five of the 11 years investigated.

Adult↗
PubMed1989

The relationships between late cutaneous responses and specific antibody responses with outcome of immunotherapy for seasonal allergic rhinitis.

Mountain cedar (MC) (Juniperus ashei) causes a significant and isolated seasonal allergic rhinitis in south-central Texas during the winter months. Retrospective studies have indicated that patients segregate into two categories based on skin test reactions: single positive skin test to MC only and multiple positive skin tests. These two populations differed in age, personal and family history of atopy, levels of both IgE and total MC-specific IgE (sIgE), and symptomatology. It has been speculated that the subjects with only a single positive skin test may actually be nonatopic and develop an IgE response to MC because of some peculiarity of the antigen. In a prospective, randomized, controlled trial, we tested the efficacy of immunotherapy (IT) with MC extract in 51 subjects, 12 single positive skin tests and 39 multiple positive skin tests, to determine if these differences indeed exist and if IT is equally effective in both groups. We failed to demonstrate significant differences in age, sex, MC sIgE, total IgE, initial immediate cutaneous response, initial late cutaneous response, or personal or family history of atopy. IT was equally effective in both groups of subjects with no significant differences noted in response to MC sIgE, MC sIgG1, MC sIgG4, or with suppression of the late cutaneous response. In addition, we found that suppression of the late cutaneous response correlated significantly with cumulative dose of MC extract, postseasonal level of MC sIgG1 and MC sIgG4, and improvement of symptomatology. Suppression of the late cutaneous response may be a clinically useful parameter to follow in monitoring patients during IT. Caution is advised because this procedure may result in systemic reactions.

Adolescent↗
PubMed1989

Suppression of the late cutaneous response by immunotherapy.

In a prospective, double-blind, placebo-controlled study, we examined the effect of mountain cedar (MC) immunotherapy on the MC-induced late cutaneous response (LCR). Fourteen MC-sensitive patients were intradermally skin tested before and after immunotherapy with MC extract. We measured the size of the wheal at 15 minutes and the area of tissue swelling at 6 hours. Patients were matched by the size of the LCR and started receiving either MC immunotherapy or placebo immunotherapy. MC-specific immunoglobulins (MC sIgG, MC sIgG1, MC sIgG4, and MC sIgE) were measured by ELISA. Symptom-medication scores (SMSs) were recorded on a daily basis during the MC season and tabulated at the end of the study. Comparison of the 14 paired patients revealed no significant differences between MC-treated and placebo-treated groups in preimmunotherapy MC sIgG1 and SIgG4. However, when MC immunotherapy was compared to placebo immunotherapy, patients receiving MC immunotherapy developed significantly higher MC sIgG1 (p less than 0.04) and MC sIgG4 (p less than 0.01) after immunotherapy. Patients receiving MC immunotherapy also demonstrated significantly greater suppression of the LCR after immunotherapy (p less than 0.005) with the postimmunotherapy LCR correlating significantly with both MC sIgG4 (rs = 0.715; p = 0.008) and cumulative dose of MC received (rs = 0.808; p = 0.004). MC sIgE was similar in both groups after immunotherapy. The reduction in SMSs in the MC-treated group did not reach significance, nor was there a correlation of SMSs with MC sIgE, sIgG, sIgG1, or sIgG4.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

The prevalence of fluorosis-like lesions associated with topical and systemic fluoride usage in an area of optimal water fluoridation.

The frequency of using self-applied (over-the-counter) fluoride products and prescribed supplemental fluorides, and the prevalence of fluorosis-like enamel lesions in the permanent dentitions of children living in an optimally fluoridated urban community were investigated. Subjects were selected randomly, and consent forms and questionnaires concerning fluoride usage and residency status were provided to guardians prior to examination. After a supervised tooth brushing event, 300 consenting subjects were examined by the principal investigator using Dean's index to assess levels of fluorosis-like lesions. The principal investigator was standardized with another investigator prior to the examinations to obtain an interexaminer agreement level of 97%, and an intraexaminer agreement level of 96%. Portable dental equipment was used during all examinations. Chi-square analysis indicated no statistically significant difference between the frequency of tooth brushing with a fluoridated dentifrice at an early age and the prevalence of fluorosis-like enamel lesions. However, there was a significant difference (P less than 0.05) between the prevalence of fluorosis-like lesions, and the frequency of using prescribed fluoride supplements and gels, and over-the-counter rinses.

Adolescent↗
PubMed1986

Dentistry's commitment to Head Start: an evaluation of selected programs.

The effectiveness of seven randomly selected dental Head Start programs in meeting national and regional standards is evaluated. The dental health education component, topical fluoride application, and classroom oral hygiene aspects, except for in one program, were being conducted in an outstanding manner.

Child Day Care Centers↗
PubMed1984

Prolonged hypnotic response to triazolam-cimetidine combination in an elderly patient.

An 82-year-old white female developed a 36-hour episode of unresponsiveness/drowsiness after a single dose of triazolam 0.5 mg in combination with cimetidine. This case illustrates the need for careful dose-titration of drug therapy in the elderly, particularly when a drug with the potential to impair drug metabolism is coadministered. Cimetidine, when coadministered with triazolam, may increase the intensity and duration of action of single doses of triazolam.

Aged↗
PubMed1982

Benzodiazepine withdrawal syndrome: a literature review and evaluation.

The capacity of the benzodiazepine drugs to produce dependence and addiction has been associated with what has recently been recognized as a benzodiazepine withdrawal syndrome. Abrupt discontinuation of benzodiazepine treatment may show a spectrum of symptoms similar to those observed from withdrawal of alcohol or barbiturates. Such reactions have been reported with and are reviewed for the following drugs: chlordiazepoxide, diazepam, oxazepam, lorazepam, nitrazepam, temazepam, and clobazam. Generally, the higher the dose and the longer the benzodiazepine is taken, the greater the risk of developing withdrawal symptoms. However, withdrawal symptoms may occur in patients receiving recommended doses and/or short-term therapy. Although most withdrawal reactions have been reported with the long-acting benzodiazepines having psychoactive metabolites, reactions may also occur with the short-acting agents. In contrast, rebound insomnia occurs with greater frequency and severity with the short-acting agents. Benzodiazepine therapy should be stopped as early as possible, with tapering after moderate dose and/or prolonged use therapy.

Anti-Anxiety Agents↗