Biomedical subjects

R V Gardner

Publications and source records attributed to R V Gardner.

5 recordsLinked to original sources

PubMed1988

The decrease in long-term marrow repopulating capacity seen after transplantation is not the result of irradiation-induced stromal injury.

Marrow cells from nonirradiated F1-W/Wv mice repopulated slightly less well than cells from lethally irradiated recipients. Therefore, avoiding irradiation of recipients did not improve the relative repopulating ability of their marrow cells. In other experiments, F1-W/Wv mice were transplanted by parabiosis with marrow of WBB6F1-+/+ (F1-+/+) mice, avoiding cellular handling and irradiation. Marrow cells transplanted to F1-W/Wv mice by this procedure demonstrated slightly better repopulating ability than did marrow cells transplanted by injection. However, they performed no better than those transplanted by parabiosis to irradiated F1-+/+ recipients. Significant impairment of stromal function after irradiation was not indicated. Apparently, stem cell damage caused by transplantation may have greater importance in causing loss of stem cell replicative potential than effects of irradiation-induced stromal injury.

Animals↗

PubMed1988

The University of Florida sickle cell screening program for neonates: design and results.

During the first 18 months of a pilot program for sickle cell screening at the University of Florida College of Medicine, Gainesville, 2,058 black neonates were screened. An incidence of homozygous sickle disease of 0.5 percent was greater than that expected or predicted by carrier frequency (8.3 percent). Fifty percent of all infants with abnormal cord blood electrophoreses were retested. All infants with actual homozygous disease or other clinically significant variants had confirmation of their diagnosis and were channeled for appropriate care. A change of phenotypic diagnosis based on a follow-up sample was made in eight cases. Errors were either interpretational or through contamination of cord blood samples by maternal blood at the time of delivery. Although location of infants for retesting after discharge was made more difficult by the largely rural composition of the target population, certain measures were taken to improve patient retrieval: use of public health personnel; enlistment of the aid of private physicians in the community; and inclusion of information regarding the screening program in the hospital discharge packets of black mothers. It is concluded that screening programs serving rural populations can adequately identify infants with abnormal hemoglobin patterns while educating and caring for families of these infants in a cost-efficient and effective manner.

Anemia, Sickle Cell↗

PubMed1986

The effect of T cells from patients with infectious mononucleosis on CFU-CGM proliferation: a preliminary report.

The neutropenia occurring during infection is a poorly understood phenomenon. Immunologically-stimulated T lymphocytes, acting upon normal bone marrow stem cells, have been etiologically implicated in several disorders. Fifteen patients, ages 17 to 25 years, and diagnosed with infectious mononucleosis by positive heterophile titers, were studied. Peripheral blood T lymphocytes were separated using sheep red blood cell rosetting. They were then cocultured with normal bone marrow cells, in a concentration of 2 X 10(4) cells/ml, in methylcellulose containing 10% colony-stimulating activity. Normal BM was obtained from patients with nonmalignant hematologic disorders, or leukemia in remission. Bone marrow cells were cultured at a concentration of 1 X 10(5) or 5 X 10(5) cells/ml, alone (control) or with T lymphocytes. Plates were incubated at 37 degrees C with 5% CO2. Colonies were scored at 14 days. Inhibition of normal, bone marrow growth was observed at both concentrations, after addition of T lymphocytes to the culture system. Such suppression was significant (p less than 0.05) for the lower concentration of normal bone marrow cells only. Variable and partial abrogation of effect was seen after overnight incubation of T lymphocytes, possibly due to loss of suppressor activity. There were insufficient numbers of tests with supernatant to allow computation of statistical significance. Correlation between T-cell ratios and suppressive effect has not been determined, although it is suspected that the responsible cells are within the T-suppressor fraction.

Adolescent↗

PubMed1985

High-dose cyclophosphamide and intermediate-dose methotrexate for the treatment of far-advanced Burkitt's lymphoma.

Ten consecutive patients were entered on a pilot study--for the treatment of children with far-advanced Burkitt's lymphoma--which was conducted at the Roswell Park Memorial Institute (R.P.M.I.) and the University of Rochester Medical Center (U. of R.). With the use of high-dose cyclophosphamide (HDC), intermediate-dose methotrexate (IDM), vincristine (VCR), prednisone (PRED), and intrathecal (IT) chemotherapy, nine of these 10 children achieved a complete remission (CR), and six of these nine children have remained in CR for more than 3 years and are likely cured of their disease. This regimen had significant, but generally manageable, toxicity. A single patient with ataxia-telangiectasia died during induction therapy of pneumonia and a gastrointestinal hemorrhage. A single patient with severe hemorrhagic cystitis required the substitution of cytosine arabinoside for cyclophosphamide (Cytoxan) in the regimen. One of five children presenting with bone marrow involvement survives. Such involvement appears to place patients at greater risk for developing meningeal disease. Attempts at more aggressive methods of central nervous system (CNS) prophylaxis should be employed in this group of patients.

Adolescent↗

PubMedDate not supplied

The role of eosinophil in regulation of granulopoiesis.

An association between eosinophilia and neutropenia has been observed in a number of clinical conditions. To probe the role of eosinophils in granulopoiesis, marrow and peritoneal eosinophils, obtained from Schistosoma mansoni-infected mice, were separated and purified. Normal bone marrow cells were cultured in semi-solid culture medium in concentrations ranging from 5 X 10(4) to 5 X 10(5), with and without added eosinophils. To examine whether high prostaglandin E (PGE) content of eosinophils affects granulopoiesis, indomethacin was added to duplicate marrow cultures containing eosinophils. The addition of eosinophils to normal syngeneic marrow culture caused a significant inhibition of granulocyte-macrophage colony formation (CFU-GM) in culture. This suppressive effect was reversible upon addition of indomethacin. These findings suggest that eosinophils, in vitro, are capable of inhibition of granulopoiesis. The reversal of this effect by indomethacin indicates that this suppression may be prostaglandin mediated.

Alprostadil↗