Biomedical subjects

G E Rodey

Publications and source records attributed to G E Rodey.

At least 73 records · Page 4Linked to original sources

PubMed1976

A new method for studying splenic reticuloendothelial dysfunction in sickle cell disease patients and its clinical application: a brief report.

Differential interference contrast (DIC) microscopy (Nomarsky optics) readily demonstrates the formation of "pits" or crater-like depressions in red cell membranes of splenectomized individuals. Splenic reticuloendothelial dysfunction characteristic of many patients with sickle cell disease (SCD) can be demonstrated by technetium spleen scans, but this technique is expensive, requires injection of radioactive material into children, and is cumbersome to perform at regular intervals. However, pit formation in red cells, which also appears to reflect splenic dysfunction, can readily be quantitated in a finger-stick blood sample using DIC microscopy. In this study, the degree of red cell pitting was compared with results of technetium spleen scans and measurements of Howell-Jolly bodies in individuals with sickle cell disease. The average pitted cell percentage in the control population was 0.5% +/- 0.5 (range 0.0-2.6) and 30.5% +/- 13.9 in the SCD population (range 2.4-71.1) (less than 0.001). Of the individuals studied with SCD, 12 also had technetium (99mTc) sulfur colloid scans and measurements of Howell-Jolly bodies. The percentage of Howell-Jolly bodies was low and did not correlate well with the degree of splenic visualization. However, there was an excellent correlation between pit count and splenic dysfunction as measured by spleen scan. Determination of red cell pitting, therefore, appears to offer a simple means for clinical evaluation of splenic reticuloendothelial function in patients with SCD.

Adolescent↗

PubMed1976

Mitigation of graft-versus-host disease in mice by treatment of donors with bacterial endotoxin.

Treatment of DBA/2 (H-2d) mice with bacterial endotoxin prior to transplantation of their spleen and lymph node cells into immunosuppressed AKR (H-2k) mice prevented acute mortality from graft-versus-host (GVH) disease. AKR mice that received immunocompetent cells from untreated DBA/2 mice had a median survival time (MST) of 13 days. In contrast, AKR mice that received immunocompetent cells from endotoxin-treated DBA/2 donors had an MST of 54 days. Endotoxin treatment of AKR recipients was not essential for preventing mortality from acute GVH disease. Chimerism was proved by demonstrating that the lymphoid cells of long-term surviving AKR mice had the characteristics of DBA/2 lymphoid cells as measured by their response in mixed leukocyte culture (MLC) tests. Spleen cells from endotoxin-treated DBA/2 mice were able to stimulate, and to be stimulated by, AKR spleen cells in MLC assays. Furthermore, spleen cells from endotoxin-treated DBA/2 mice did not suppress the responses of DBA/2 or AKR spleen cells in 'three-party' MLC tests.

Animals↗

PubMed1976

Measurement of the fractional uptake of macromolecules by the renal vascular bed compared to other vascular beds.

Macromolecules resembling soluble immune complexes can be made from heat-aggregated human gamma globulin (AHGG). In 15 rats, we studied vascular trapping of 125I-labeled AHGG (AHGG)-125I) given by constant I.V. infusion over 1 hour while tissue blood flow was marked by intermittant aortic arch injections of 85Sr-labeled microspheres. Red cells labeled with 51Cr (RBC-51Cr) were also infused so that when the tissues were removed at the end of the experiment, the vascular volume of each tissue specimen could be balculated to correct issue 125I for AHGG-125I which was not trapped but simply in transit in the bascular space at the time the tissue was removed. These data permitted us to calculate the fractional uptake of AHGG-125I (FM) for a given tissue in comparison to any other tissue. We chose to compared the FM of each tissue to the FM of renal cortex. This comparison was expressed as a ratio termed the FM ratio for the given tissue. The following tissues had FM ratios significantly greater than 1.00 (i.e., per unit blood flow, these tissues trapped AHGG-125I more avidly than renal cortex): liver, spleen, skin, stomach, fat, testes, and large bowel. The respective ratios were 381 +/- 74, 15.7 +/- 4.0, 11.8 +/- 4.0, 7.47 +/- 1.95, 6.24 +/- 1.0 +/-, 3.03 +/- 0.67, 2.86 +/- 0.72 (all p less than 0.025). The FM ratio for adrenal, heart, thymus, and diaphragm were not significantly different from 1.00. The FM ratio of lung and brain were significantly less than 1.00: 0.014 +/- 0.008 and 0.14 +/- 0.065, respectively (p less than 0.001 for both). In 13 experiments, glomeruli was 23.8 +/- 3.5 per cent as assessed by recovery of the microspheres contained in renal cortex. Compared to whole renal cortex, the isolated glomeruli contained only minor amounts of AHGG-125I. We conclude that tissues vary widely with respect to their ability to trap macromolecules. When uptake is viewed in terms of the amount of complex trapped per unit delivery rate, many organs trap AHGG-125I for more avidly than renal cortex. Furthermore, under the present experimental conditions, glomeruli are not the major intrarenal site of macromolecule uptake.

Animals↗

PubMed1976

Alternative complement pathway activity in sera from patients with sickle cell disease.

The low molecular weight cobra venom factor (CoVF) was used to activate the terminal sequence of the alternative complement pathway in thirty-one sera from patients with sickle cell disease (SCD). The SCD sera were compared with normal sera as a source of the alternative complement pathway factors C3 proactivator (C3PA) and C3PA convertase. These factors are required for formation of the enzymatically active CoVF-C3PA complex which is capable of cleaving C3 and thus initiating generation of the cytolytic C5b-9 complex. CoVF cofactor activity was significantly less than normal in SCD sera as measured in an indirect lysis assay, indicating reduced C3PA or C3PA convertase activity in these sera. Qualitative (immunoelectrophoresis) and quantitative (radial immunodiffusion) measurement of C3PA showed, however, that this protein is normal or elevated in SCD sera. Taken together, the reduced CoVF cofactor activity and normal or elevated C3PA in SCD sera suggests that sera from patients with sickle cell disease have reduced C3PA convertase activity.

Adolescent↗

PubMed1975

Graft versus leukemia. VI. Adoptive immunotherapy in combination with chemoradiotherapy for spontaneous leukemia-lymphoma in AKR mice.

A three-step treatment plan incorporating adoptive immunotherapy and chemoradiotherapy was used to treat AKR (H-2k) mice bearing spontaneous leukemia-lymphoma (SLL). 1) Leukemic mice were treated with chemoradiotherapy for immunosuppression and leukemia cytoreduction. 2) To introduce a graft-versus-leukemia reaction against residual malignant cells, the immunosuppressed AKR mice were given immunocompetent cells from H-2 mismatched DBA/2 (H-2d) donors. 3) To "rescue" the AKR hosts from incipient graft-versus-host disease, the mismatched DBA/2 cells were killed with combination chemotherapy, and cells from allogeneic H-2 matched RF (H-2k) donors were administered to restore hematopoiesis. Leukemic AKR mice thus treated had significant prolongation of their median survival time and a higher 60-day survival rate post treatment than did untreated controls, chemoradiotherapy controls, or control mice that received chemoradiotherapy plus cells from syngeneic donors. Therefore, adoptive immunotherapy may be useful as an adjunct to conventional therapy for treatment of SLL in AKR mice.

Amphotericin B↗

PubMed1974