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Biomedical subjects

R Levenson

Publications and source records attributed to R Levenson.

99 records · Page 6Linked to original sources
PubMed1978

Significance of the cell cycle in commitment of murine erythroleukemia cells to erythroid differentiation.

The relationship between differentiation of murine erythroleukemia cells (MEL) induced by DMSO and the cell division cycle has been analyzed. We demonstrate that incubation in the presence of DMSO increases the length of the G1 phase of the cell cycle. A method of synchronization of MEL cells by unit gravity sedimentation has been developed and characterized. Using this method, a series of synchronized cell populations covering the entire cell division cycle can be generated simultaneously. Cells synchronized by this technique were challenged with DMSO and analyzed for kinetics of commitment to the differentiation program. Our results indicate that populations of cells in G1 or G2 at the time of addition of inducer give rise to a greater proportion of committed cells than an unfractionated population, while cells in S phase result in a lower percentage of committed cells than the unfractionated population when cultured in DMSO.

Animals↗
PubMedDate not supplied

Supportive telephone intervention for patients receiving chemotherapy. A pilot study.

Psychosocial interventions have been shown to improve quality of life (QOL) for many cancer patients. A pilot study was conducted to assess the feasibility of a psychoeducational intervention for cancer patients receiving chemotherapy. Eight patients receiving chemotherapy for colorectal carcinoma participated. The intervention is based on a modification of Interpersonal Therapy. It consisted of four sessions, administered biweekly, using a manual format, by a psychiatric nurse clinician over the telephone. The participants also completed a set of QOL measures by telephone to assess tolerance of the planned assessment. The patients received assistance with treatment-related side effects, reported improved ability to communicate with their physician, and gained an understanding of the stresses they discussed. The patients felt satisfied with the emotional support and medical information provided. A randomized trial is planned to test the intervention for patients participating in a cooperative trial sponsored by the National Cancer Institute.

Aged↗
PubMedDate not supplied

Interaction between variation in the D2 dopamine receptor (DRD2) and the neuronal calcium sensor-1 (FREQ) genes in predicting response to nicotine replacement therapy for tobacco dependence.

We have previously demonstrated that a functional dopamine D2 receptor promoter variant (DRD2 -141 Ins/Del) predicts response to nicotine replacement therapy (NRT). The present study extends this finding in the same population of 363 NRT-treated subjects, by examining variation in the gene encoding the neuronal calcium sensor-1 protein (FREQ), which functions to regulate D2 receptor desensitization. The results indicate a statistically significant interaction effect of DRD2-141 and FREQ genotypes on abstinence at the end of the NRT treatment phase; 62% of the smokers with at least one copy of the DRD2 -141 Del allele and two copies of the FREQ rs1054879 A allele were abstinent from smoking, compared to 29-38% abstinence rates for other smokers in the trial. This result suggests that the interaction between variation in the DRD2 and FREQ genes, which both encode components of the D2 dopamine receptor signal transduction pathway, impacts the efficacy of NRT.

Administration, Cutaneous↗
PubMedDate not supplied

Do weighted nasoenteric feeding tubes facilitate duodenal intubations?

A widely held assumption is that postpyloric intubations occur more often with weighted than with unweighted nasally inserted feeding tubes. This randomized, prospective study compared the frequency of duodenal intubations using weighted and unweighted nasoenteric feeding tubes. One hundred sixteen patients had either weighted (61 patients) or unweighted (55 patients) 10F silicone elastomer feeding tubes inserted nasally 85 cm. Tubes were placed with wire stylets. Tube positions were verified radiographically within 4 hr after insertions. Radiographs were repeated daily for 3 days or until duodenal intubation occurred. Successful duodenal intubations were achieved in 35 patients (57%) with weighted feeding tubes and in 37 patients (67%) with unweighted feeding tubes. This difference was not significant. Weighted nasoenteric feeding tubes offer no advantage over unweighted tubes in achieving duodenal intubations.

Adolescent↗
PubMedDate not supplied

Inpatient immunization program: eliminating a missed opportunity.

In response to the nation's low immunization rates among preschool-aged children, health care providers need to consider alternate sites as potential opportunities to administer vaccinations. One hospital established a Childhood Immunization Group designed to identify and provide immunizations to hospitalized children, 0-2 years of age. Sixty percent of the over 1,600 children evaluated have required immunizations in which 70% of these were immunized prior to discharge. The integration of primary care with "hospital care" can contribute to improving the immunization rate of preschool-aged children.

Child Health Services↗