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Biomedical subjects

A Rice

Publications and source records attributed to A Rice.

18 recordsLinked to original sources
PubMed1992

Mobilized blood stem cells: immunophenotyping and functional characteristics.

High levels of peripheral blood stem cells (PBSC) can be collected from patients with hematopoietic malignancies or solid tumors after high-dose chemotherapy and/or growth factors. Rapid, complete, and durable hematopoietic reconstitution has been observed in patients who have been transplanted with PBSC after conditioning with supralethal myeloablative therapy. We will review the recent data concerning the immunophenotype and functional capacities of mobilized blood stem cells. PBSC seem to be comprised of a mixture of primitive and committed hematopoietic progenitors and are not that different from bone marrow-derived stem cells.

Cells, Cultured↗
PubMed1992

Incomplete stroma formation after allogeneic marrow or autologous blood stem cell transplantation.

Long term and semi-solid culture techniques were used to evaluate the quality of stroma produced by bone marrow from 33 normal subjects and 57 patients (46 allogeneic bone marrow and 11 autologous blood stem cell transplant recipients). Bone marrow from transplant recipients was capable of sustained CFU-GM and nucleated cell production in long term culture. However, only 13% of the marrow investigated developed a complete, confluent stromal layer. These stromal abnormalities were observed in spite of complete hematopoietic reconstitution after transplantation and rarely improved with time. Our results suggest that the hematopoietic microenvironment is very fragile and susceptible to long term damage as a result of chemotherapy and the conditioning regimes used prior to transplantation.

Adolescent↗
PubMed1989

Long-term culture of peripheral blood stem cells: the effect of the addition of an irradiated stromal layer.

We have studied peripheral blood stem cells (PBSC) collected by cytapheresis following intensive chemotherapy, from 13 patients with acute leukemia, in long term culture (LTC). Peripheral blood was cultured with (n = 10) and without (n = 21) the addition of a preformed, irradiated stromal layer. In this latter LTC our results confirm that peripheral blood is capable of producing CFU-GM and nucleated cells in the absence of the formation of an adherent stromal layer. However, peripheral blood cultured in the presence of an irradiated stromal layer is capable of a significantly higher proliferative response (total production of CFU GM per flask - mean = 57529) than in the absence of an irradiated stromal layer (total production of CFU GM per flask - mean = 26739, p less than 0.03). Our results suggest that PBSC contain a primitive nonplastic adherent cell that requires the presence of a stromal layer for its expression. These findings provide further support for the use of peripheral blood stem cells for autologous transplantation.

Cells, Cultured↗
PubMed1989

[Autograft of blood stem cells].

Autologous blood stem cell transplantation (ABSCT) is a new technique which has been increasingly used in recent years. It is now well established that ABSCT can be performed as safely as autologous bone marrow transplantation (ABMT) when high numbers of hemopoietic precursors are infused. Multiple leukophoreses are performed during marrow regeneration following chemotherapy-induced aplasia. Hemopoietic recovery (predominantly the granulocytic series) is probably faster after ABSCT than after ABMT. Among other advantages there may be minimal contamination by residual tumor cells in buffy-coats; however, this has not been fully investigated.

Hematologic Diseases↗
PubMed1986

Mid-trimester levels of alphafetoprotein in the screening of low birthweight.

Elevated maternal levels of alphafetoprotein (AFP) in midtrimester are believed by some to be a useful screening test for premature labour, low birthweight and low birthweight for gestation. In a prospective study on 887 randomly selected pregnant women we found that although there was an association between low birthweight and elevated AFP, the test would miss five out of every six cases of low birthweight and there would be nine false-positives for every case correctly identified. The test is not therefore sufficiently predictive of low birthweight to be of value as a screening test for this condition.

False Positive Reactions↗
PubMed1985

Dramatic increase of placental protein 5 levels following injection of small doses of heparin.

In the course of an investigation on the effects of thyroid releasing hormone in pregnant women we noted a dramatic increase in the levels of placental protein 5 (PP5) in maternal blood. This increase ranged from 10 times to over 40 times the basal levels. Further study showed that the rise was associated with the use of heparin to maintain the patency of the cannula through which the samples were collected. Furthermore, the phenomenon appeared to be systemic rather than local, and may well be due to a direct effect of heparin on PP5 secretion by the placenta.

Female↗