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Biomedical subjects

D J Tucker

Publications and source records attributed to D J Tucker.

18 recordsLinked to original sources
PubMed1999

Antiretroviral adherence issues among HIV-positive adolescents and young adults.

A total of 31 youth from a multidisciplinary adolescent human immunodeficiency virus clinic were surveyed to gain information about their adherence to complex antiretroviral regimens and elucidate factors that may be associated with adherence. Results indicated that 61% of subjects reported >90% compliance with their medications in the previous 90 days.

Adolescent↗
PubMed1998

Fractures of the lateral process of the talus: two case reports and a comprehensive literature review.

Fractures of the lateral process of the talus are frequently overlooked and should be considered in the differential diagnosis of patients with acute and chronic ankle pain. Early diagnosis is emphasized in all series reviewed in the literature to prevent long-term complications. Thorough radiographic evaluation is necessary to determine the need for operative vs. nonoperative management. Small nondisplaced fractures are treated with cast immobilization, whereas large or displaced fractures usually require open reduction and internal fixation. Comminution of fragments may necessitate surgical excision. To achieve the best possible results, a timely diagnosis is required, and it is our belief that early treatment has better overall results.

Adult↗
PubMed1996

Determination of morphine in process streams by sequential injection analysis with chemiluminescence detection.

A procedure for the determination of morphine in process streams by sequential injection analysis based on the chemiluminescence reaction of morphine with acidic potassium permanganate in the presence of sodium hexametaphosphate is presented. The chemiluminescence emission has been monitored using an in-house detection system which consisted of a fibre optic flowthrough cell and a sensitive, low dark current, photomultiplier tube. The calibration graph (range 2 x 10(-8) to 1 x 10(-4) mol/l) was not linear over the entire range of concentration, with a polynomial equation of best fit of y = 1.0 x 10(15) x(3) - 2.2 x 10(11) x(2) + 1.3 x 10(7) x - 8.3. The calibration function approximates linearity over the concentration range 2.5 x 10(-6) to 3.0 x 10(-5) mol/l where the slope of the log-log plot is 1.09 +/- 0.16. The detection limit was estimated at about 10(-8) mol/l from the response of the lowest calibration standard (2.5 x 10(-8) mol/l) which gave a signal to noise ratio of 3 : 1. Although the structurally related codeine did not interfere significantly the results suggest that this method may be susceptible to matrix effects, dependent on the location of sampling from the process stream.

Journal Article↗
PubMed1996

Nailbed injuries with hallucal phalangeal fractures--evaluation and treatment.

Adequate assessment of crush injuries to the hallux is necessary before appropriate management can be initiated. When distal phalangeal fractures of the hallux are detected by routine radiography and subungual hematomas are present, open fractures of the hallux may be overlooked if the physician does not routinely avulse the nailplate. The authors review current modalities for the detection and evaluation of these injuries and present a protocol for treatment.

Anti-Bacterial Agents↗
PubMed1991

Quantitation of tryptophan and other plasma amino acids by automated pre-column o-phthaldialdehyde derivatization high-performance liquid chromatography: improved sample preparation.

Pre-column derivatization with o-phthaldialdehyde is a rapid and sensitive method for the quantitation of amino acids in biological fluids. This method uses acetonitrile as a deproteinizing reagent which gives improved recovery of tryptophan compared with 5-sulfosalicylic acid and permits the measurement of aspartic acid which coelutes with 5-sulfosalicylic acid. The method is automated to increase reproducibility and convenience. Mean coefficients of variation for peak areas relative to internal standard were 3.2 and 5.2% for amino acid standards and plasma samples, respectively. The presence of nitrilotriacetic acid stabilized the o-phthaldialdehyde reagent which is important in an automated system. The method is suitable for the analysis of large numbers of plasma samples where total tryptophan and aspartic acid are of interest.

Acetonitriles↗
PubMed1984

Changes in urinary homocysteine following synthetic steroidal estrogen and progestogen administration to rats.

The present work involved the administration of both ethynyl estradiol and levonorgestrel to groups of rats, followed by determination of the homocysteine excretion rate in urine. The results indicate that a statistically significant difference exists between the excreted levels of homocysteine in the urine of both control and levonorgestrel-treated rats and the levels shown by rats treated with ethynyl estradiol. The implications of these results are discussed, especially with respect to observations which indicate that homocysteine may be a precipitating factor in the development of thrombosis. Also included in this paper is a study which confirms the identity of the HPLC peak as being homocysteine by forming a radioactive derivative of this particular sulphydryl-containing amino acid, and then analysing the resulting mixture by TLC.

Animals↗
PubMed1980

Coordination and citizen participation.

This study investigates the validity of the assumption that coordination and citizen participation are related inversely and, thus, are incompatible as features in the same social service reform strategy. Seventeen social service organizations situated in the same urban area were studied. Data were obtained by structured interview. The concepts of coordination and citizen participation were operationalized by means of scales. The findings support the validity of the assumption noted above. Although interpretations of the findings can be provided, they are post-factum. This implies a need for explanatory research which might be guided by theories of community power structure and of organizational behavior.

Canada↗
PubMed1980

Teaching severely multihandicapped students to put on their own hearing aids.

Two experiments were conducted with six severely multihandicapped students with hearing impairments to: (a) train the six students to put on their own hearing aids independently, and (b) provide an empirical evaluation of a comprehensive instructional program for putting on a hearing aid by assessing acquisition, maintenance, and generalization of that skill across environments. All six students acquired the skill rapidly, with two students requiring remedial training on one step of the program. Because for two of the original three students the newly learned skill failed initially to generalize to other environments, a second experiment was initiated to assess generalization across environments as well as to replicate the efficiency of the acquisition program. When a variation of the multiple-probe baseline technique was used, the behavior of three additional students generalized to other settings without direct training in those settings.

Adolescent↗
PubMed1973

Increasing mentally retarded adolescents' verbalizations about current events.

The effects of antecedent and consequent events on the verbal behavior of three institutionalized mentally retarded adolescents were examined. Verbal statements, related to current national and international events, were recorded after exposures to television news programs. The study examined the accuracy of verbalizations as a function of: (1) exposures to television news presentations in massed (i.e., viewing the entire news program before an opportunity to describe it) versus distributed from (i.e., viewing each news item separately with each followed by an opportunity to describe it), and (2) contingent tokens and social praise for correct verbal responses (i.e., statements corresponding to news items presented). Both the temporal distribution of news presentations and the reinforcement procedures improved the accuracy of verbal statements emitted by the subjects.

Journal Article↗
PubMedDate not supplied

Lateral subtalar dislocation: review of the literature and case presentation.

Lateral subtalar joint dislocations are rare injuries which are usually the result of a violent eversional force, driving the talar head medially and displacing the rest of the foot laterally. Associated fractures and obstruction to closed reduction are more common with lateral than medial dislocations. Avascular necrosis of the talus and navicular as well as subtalar instability may result from these injuries. Severe post-traumatic subtalar arthritis may warrant triple arthrodesis. Prompt closed reduction of lateral subtalar dislocation is recommended to avoid soft-tissue or neurovascular compromise. A short period of immobilization limits loss of subtalar range of motion. Open reduction may be required, particularly with entrapment of the posterior tibial tendon or obstructing fracture fragments. A case of lateral subtalar joint dislocation is presented.

Aged↗