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Biomedical subjects

E D Smith

Publications and source records attributed to E D Smith.

At least 37 records · Page 2Linked to original sources
PubMed1991

Induction of multiple plasmid recombination in Saccharomyces cerevisiae by psoralen reaction and double strand breaks.

DNA damage-induced multiple recombination was studied by cotransforming yeast cells with pairs of nonreplicating plasmids carrying different genetic markers. Reaction of one of the plasmids with the interstrand crosslinking agent, psoralen, stimulated cellular transformation by the undamaged plasmid. The cotransformants carried copies of both plasmids cointegrated in tandem arrays at chromosomal sites homologous to either the damaged or the undamaged DNA. Plasmid linearization, by restriction endonuclease digestion, was also found to stimulate the cointegration of unmodified plasmids. Disruption of the RAD1 gene reduced the psoralen damage-induced cotransformation of intact plasmid, but had no effect on the stimulation by double strand breaks. Placement of the double strand breaks within yeast genes produced cointegration only at sequences homologous to the damaged plasmids, while digestion within vector sequences produced integration at chromosomal sites homologous to either the damaged or the undamaged plasmid molecules. These observations suggest a model for multiple recombination events in which an initial exchange occurs between the damaged DNA and homologous sequences on an undamaged molecule. Linked sequences on the undamaged molecule up to 870 base pairs distant from the break site participate in subsequent exchanges with other intact DNA molecules. These events result in recombinants produced by reciprocal exchange between three or more DNA molecules.

Cloning, Molecular↗
PubMed1991

Family dysfunction and the cancer patient: early recognition and intervention.

Cancer affects the entire family, not just the patient. Dysfunctional family systems can be assessed by looking for recurrent patterns of maladaptive processes that exclude other coping mechanisms. Intervening to ameliorate the situation in such families involves development of a plan to restore equilibrium wherever possible; when appropriate, a mental-health referral may be needed for families with severe dysfunction. A physician must know how to assess and appropriately intervene in dysfunctional family systems, both when support services are and are not available for assistance. To explain recognition and anticipation of the early signs of family dysfunction to the practicing oncologist, Olsen's Circumplex Model of family functioning is presented as a theoretical frame for assessment and intervention.

Adaptation, Psychological↗
PubMed1990

Acid etching of a glass ionomer cement base: SEM study.

The effects of acid-etching duration on the surface of a glass ionomer cement designed for use as an intermediary layer between composite resin and dentine were investigated. Cement topography changes occurred which could be related to etch duration. When compared with enamel etched for a similar period, undue loss of cement substance was not observed for any of the etch times used.

Acid Etching, Dental↗
PubMed1990

The "REST" program: a new treatment system for the oppositional defiant adolescent.

This study compared the REST (Real Economy System for Teens) program with traditional talk therapy in the treatment of oppositional defiant adolescents. The REST program uses rules for five target behaviors: room care, personal hygiene, completion of chores, abusiveness, and safety violations. Objective measures and subjective parental ratings were taken. Twenty-five adolescents were assigned to each therapy group. In the REST program the adolescent was provided with only food and shelter. The adolescent had to earn money through the REST allowance program to pay for everything else. Earning the allowance was made contingent upon compliance with all rules for the five target behaviors. The results showed significantly greater improvement on all target behaviors for the REST program than for traditional therapy. In addition, parents of adolescents in the REST group reported that their adolescents seemed happier, more relaxed, and closer to them.

Adolescent↗
PubMed1989

The role of black churches in supporting compliance with antihypertension regimens.

Although considerable gains have been made in hypertension control in the United States, the rate of control in blacks is lower than in whites. It has been asserted that this low control rate in blacks is due to lack of compliance. Using previously tested and new measures, as well as chart audit, this pilot study evaluated the specific role and effectiveness of the black church in promoting compliance with antihypertension regimens. A sample of 63 hypertensive subjects from two inner-city black churches participated; 33 were from a church that had a hypertension screening project and 30 were from one that did not. Clients from the church with the project did not score higher on a self-report compliance measure than those from the church without the project. Furthermore, no relationship was found between support and compliance and blood pressure control, although relationships were seen between age and compliance scores, and between following a doctor's advice and compliance scores. The church without a screening program was viewed by clients as more supportive than the one with the program.

Adult↗
PubMed1988

Rheologic predictors of the severity of the painful sickle cell crisis.

Deformable sickle erythrocytes have been reported by Mohandas and Evans to be more adherent to vascular endothelium than rigid irreversibly sickled cells (ISC). To define the clinical implications of this finding we have determined genetic, hematological, clinical, and rheological characteristics of sickle erythrocytes obtained from 65 patients with sickle cell anemia and fetal hemoglobin (Hb F) levels less than 15%. The alpha-globin gene number had a significant effect on the hematological parameters, the percentage of dense cells, ISC number, and HB A2 levels. The presence or absence of alpha thalassemia, however, had no effect on the frequency and severity of the sickle cell painful crisis (r = 0.06, P greater than .05). RBC deformability, determined by an ektacytometer, showed great heterogeneity among patients with three or four alpha-globin genes. Linear regression analyses of the data showed significant positive correlation of the frequency and severity of the painful crisis with RBC deformability (r = 0.49, P less than .001), and negative correlations with the percentage of dense cells (r = -0.37, P = .002), and the percentage of ISC (r = -0.46, P less than .001). We propose that the more deformable the sickle RBC are, the greater their adherence to vascular endothelium, and the more they cause vaso-occlusive crises, RBC deformability and the percentage of dense cells (or ISC) seem to have a predictive value of the frequency and severity of painful crises in sickle cell anemia.

Adolescent↗