PubMed Health⌕ Search

Biomedical subjects

R Steer

Publications and source records attributed to R Steer.

6 recordsLinked to original sources
PubMed2000

Effect of angiotensin II on hematopoietic progenitor cell proliferation.

Angiotensin II (AII) induced the proliferation of hematopoietic progenitor cells (HPC) isolated from murine bone marrow or human cord blood. The formation of colonies with more than 50 cells increased approximately five-sevenfold in cultures of murine lineage-negative (Lin(-)) bone marrow cells both in the presence (day 10) and absence (day 13) of colony-stimulating factors (CSF). This could be blocked with addition of Losartan, an antagonist of AIITR1. The increase in proliferation of early hematopoietic progenitors (Lin(-)Sca l(+) cells) by AII was approximately threefold and occurred only in the presence of CSF, suggesting that AII may affect mesenchymal stromal cells to induce CSF production and might directly affect early HPC. These in vitro studies were replicated with human HPC isolated from cord blood. AII also accelerated the proliferation and formation of colony-forming units (CFU)-granulocyte/erythroid/macrophage/megakaryocyte and CFU-granulocyte/macrophage colonies by CD34(+)CD38(-) enriched progenitors but only in the presence of CSF. Additional studies also indicated that AII can act to increase proliferation in suspension culture. Exposure of CD34(+) cells to AII in suspension culture, prior to placement in a semisolid medium with erythropoietin, increased the formation of colonies with more than 50 cells and erythroid progenitors approximately five- and 20-fold, respectively. Further, mRNA for the AT1a receptor was expressed by human bone marrow CD34(+)CD38(-) cells, CD34(+)CD38(-) cells, and lymphocytes, but not mature myeloid cells. Similarly, mRNA for the AT1a receptor was expressed on human stromal cell clones, offering further support to the hypothesis that AII acts partially through the mesenchymal compartment of the bone marrow. These data suggest that AII may be a factor which stimulates the proliferation of hematopoietic progenitors.

ADP-ribosyl Cyclase↗
PubMed1994

Factors complicating cost containment in the treatment of suicidal patients.

OBJECTIVE: The treatment of suicidal patients contributes to escalating mental health expenditures. Fiscal realities necessitate that cost-containment measures be implemented wherever possible. The authors reviewed the literature to delineate factors that impede cost containment for the treatment of suicidal patients and to outline strategies for controlling costs while improving the quality of care. METHODS: Psychological Abstracts and MEDLINE databases were reviewed. Retrieval and analysis focused on literature published between 1982 and 1992. RESULTS AND CONCLUSIONS: Five factors unique to the treatment of suicidal patients that impede cost containment were identified: the lack of a specific and cost-effective screening method to determine true risk of suicide, the high number of parasuicidal and malingering patients, revolving-door admissions of involuntary patients who become noncompliant with treatment after discharge, the adverse clinical consequences of further increases in existing discriminatory mental health benefits, and the medicolegal liability incurred in treating suicidal patients. The low frequency of completed suicides in relation to attempts and reported ideation indicates that most inpatients labeled suicidal are hospitalized unnecessarily. Thus inpatient treatment should be reserved for patients who make attempts of high lethality and patients with suicidal ideation who are at high risk because of other factors. Ideally, suicidal patients should be committed not to an inpatient facility but to a treatment network in which they can move appropriately between inpatient, day hospital, and outpatient care.

Cost Control↗
PubMed1994

Commitment decisions: identification of indeterminate cases.

Research shows that most involuntary commitments conform to legal criteria and that psychiatrists generally agree on which patients should be committed. There are many cases, however, that cause disagreement among psychiatrists making commitment decisions. No research has been done regarding types of cases causing disagreement. The authors developed 10 clinical vignettes termed "ambiguous case constructs" that could be proven to be indeterminate and explore what underlying themes these indeterminate cases might hold in common. A pilot study was conducted to develop a set of 10 clinical vignettes, which were found to be representative of psychiatric emergencies and likely to cause discordance among evaluating psychiatrists. These validated vignettes were then presented to 62 psychiatrists who were asked to determine the commitment disposition for each vignette patient. Seven of these vignettes elicited significant disagreement among respondents and were identified as indeterminate cases. The frequency and percentage of psychiatrists endorsing commitment for each vignette is listed. This study validates the existence of indeterminate cases which prompt disagreement among psychiatrists making commitment decisions. Upon retrospective review, disagreement evoked by the seven indeterminate cases is proposed to have originated from one of four themes. The implications for clinical practice are noted.

Adult↗