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Biomedical subjects

D Guerry

Publications and source records attributed to D Guerry.

At least 55 records · Page 3Linked to original sources
PubMed1982

Action spectrum for retinal injury from near-ultraviolet radiation in the aphakic monkey.

We found that the action spectrum for retinal damage (determined by the fundus photographic appearance of a minimal lesion immediately after exposure) extends into the near-ultraviolet by exposing three aphakic eyes from rhesus monkeys to 405-, 380-, 350-, and 320-nm wavelengths produced by a 2,500-W xenon lamp equipped with quartz optics and 10-nm interference filters. Exposure times were 100 and 1,000 seconds and the spot diameter on the retina was 500 micrometers. The retina was six times more sensitive to 350- and 325-nm wavelengths than to blue light (441 nm). Both ophthalmoscopic and histologic data showed that near-ultraviolet lesions differed in important respects from blue-light lesions. Near-ultraviolet produced irreparable damage to rod and cone photoreceptors.

Animals↗
PubMed1982

Granulocyte-associated IgG in neutropenic disorders.

We applied a radiolabeled antiglobulin test to a study of patients with a variety of neutropenic disorders. After defining the nature of the interaction of radiolabeled anti-IgG with the neutrophil, we studied 16 patients with neutropenia of uncertain etiology and adequate bone marrow granulocyte precursors. Twelve of these 16 patients had increased neutrophil-associated IgG (PMN-IgG). Patients with the highest levels of PMN-IgG had the lowest neutrophil counts. The majority of patients with neutropenia and increased PMN-IgG had an underlying immunologic disorder that included immune thrombocytopenic purpura in 5 patients and autoimmune hemolytic anemia in 1 patient. In some patients, elevated PMN-IgG preceded other evidence for immunologic disease. The direct antiglobulin test helped to distinguish neutropenic patients with increased PMN-IgG both from patients with neutropenia due to a known nonimmune disorder and from nonneutropenic patients with rheumatoid arthritis or systemic lupus erythematosis. Each of four patients with increased neutrophil-associated IgG treated with systemic corticosteroids responded clinically with an associated fall in neutrophil IgG and a rise in the circulating neutrophil count. The radiolabeled antiglobulin test appears useful in defining a subpopulation of patients with neutropenia due to an underlying immunologic disorder.

Adrenal Cortex Hormones↗
PubMed1982

Malignant angioendotheliomatosis proliferans treated with doxorubicin.

An 84-year-old man was examined for progressive pain, edema, and infiltrating skin lesions on his lower extremities. A skin biopsy specimen confirmed the suspected diagnosis of angioendotheliomatosis proliferans. The clinical course and histologic changes suggested the malignant form of this disease. Treatment with intravenous doxorubicin hydrochloride caused a complete clinical remission.

Aged↗
PubMed1981

Proliferation, differentiation, and cytogenetics of chronic leukemic B lymphocytes cultured with mitomycin-treated normal cells.

Lymphocytes from 6 patients with chronic lymphocytic leukemia of the B-cell variety (B-CLL) were cultured with equal numbers of mitomycin-treated mononuclear cells from normal blood. When stimulated with pokeweed mitogen (PWM), phytohemagglutinin (PHA), or the tumor-promoting agent, phorbol tetradecanoyl-acetate (TPA), the CLL cells proliferated actively by day 3 or 4 of culture, and in four cases, differentiated to significant numbers of immunoglobulin-containing cells. Chromosome studies on the proliferating lymphocytes demonstrated a cytogenetically abnormal clone in three patients, including two with a 14q+ marker chromosome and two with a translocation involving the short arm of chromosome 9. One patient had a translocation from 22q to 14q, producing a Philadelphia chromosome as well as the 14q+ marker. The results indicate that the neoplastic lymphocytes of B-CLL may proliferate and differentiate when appropriately stimulated in vitro, and that chromosomally abnormal clones are not uncommon. With several techniques now available for successful short-term culture of B-CLL lymphocytes, there is opportunity for better understanding of the cellular alterations in this disease.

B-Lymphocytes↗
PubMed1981

Cytogenetic evidence for the clonal nature of Richter's syndrome.

Sequential chromosome studies were done on a patient who developed diffuse histiocytic lymphoma (DHL) after a long history of untreated chronic T-cell leukemia. During the indolent phase of her disease, a pseudodiploid lymphocyte population with 3q+ and 14q+ chromosome markers gradually replaced the originally diploid tumor cells. The karyotype of the lymphoma was hypertriploid (70--74 chromosomes) with the same 3q+ and 14q+ markers. The findings indicate that DHL in this patient evolved from the leukemic T-cell clone.

Clone Cells↗
PubMed1979

Factor XII deficiency with systemic lupus erythematosus. Biological implications.

A patient with Factor XII (Hageman) deficiency and fulminant systemic lupus erythematosus is presented. The Factor XII deficiency was noted prior to the onset of clinical systemic lupus erythematosus and persisted throughout the patient's course without associated hemorrhagic manifestations. There was no evidence for a circulating anticoagulant. The patient had a rapidly progressive fatal course unresponsive to corticosteroid therapy. Factor XII levels did not increase during therapy with steroids. Despite absence of Hageman factor, evidence for activation of complement by the classic pathway and thromboembolic phenomenon was observed. The role of Factor XII in coagulation and inflammatory pathways and the influence of the factor deficiency on the course of the patient's illness are discussed.

Adolescent↗
PubMed1979

Human monocyte-lymphocyte interaction and its enhancement by levamisole.

We investigated the role of monocyte-lymphocyte interaction in the transformation of human peripheral blood lymphocytes by the mitogen concanavalin A (Con A). Human monocytes were separated from lymphocytes and were transiently exposed to Con A. The Con A-pretreated monocytes were able to subsequently bind autologus lymphocytes by a process that was selective for T cells. This interaction required the initial presence of Con A at the monocyte surface, and became independent of surface bound ligand after 72 hr. Levamisole, an agent thought to facilitate the participation of monocytes in the cellular immune response, enhanced the binding of lymphocytes to monocytes at low concentration of Con A (5--10 micrograms/ml). Levamisole did not lead to mitogen independent lymphocyte binding. The association between lymphocytes and Con A-pretreated monocytes resulted in the mitogenic transformation of lymphocytes in the absence of soluble Con A in the medium. These results suggest that, in addition to any possible soluble mediators, direct lymphocyte-monocyte contact is required for optimal mitogenic transformation. This T-cell-monocyte interaction over time becomes independent of cell-surface mitogen. The ability of levamisole to enhance this interaction may explain levamisole's capacity to stimulate lymphocyte proliferation.

Adult↗
PubMed1978

Dural arteriovenous fistula and spontaneous choroidal detachment: new cause of an old disease.

A case is presented in which bilateral spontaneous choroidal detachments appear to be the direce result of bilateral dural arteriovenous fistula of the cavernous sinus region. Rapid resolution of the clinical signs followed bilateral orbital decompression via the transfrontal approach. Similarities in clinical presentation of both entities are reviewed and a premise for their cause-and-effect relationship elaborated. A literature search for similar unrecognised cases is discussed. The paper suggests that this association may be more frequent than published reports would imply.

Aged↗
PubMed1977

A randomized clinical trial of granulocyte transfusions for infection in acute leukemia.

In a prospective, controlled, randomized study to evaluate the efficacy of filtration-leukapheresis granulocytes in granulocytopenic, febrile patients with leukemia, 19 patients received antibiotics alone, and 12 received antibiotics plus daily granulocyte transfusions from ABO-matched donors. In skin-chamber studies the granulocytes appeared at sites of inflammation for at least six hours after transfusion. Infected subjects survived longer if they received granulocytes. Differences between control and transfused patients were greatest in patients with persistent bone-marrow failure, the 21-day survival being 20 per cent in controls, and 75 per cent in transfused patients. Granulocytes appeared to have no effect on the outcome of febrile episodes in which infection was not documented, the 21-day survival being 79 per cent for controls and 88 per cent for transfused patients. The transfusion of granulocytes thus appears to offer a survival advantage to infected, persistently granulocytopenic patients.

Acute Disease↗
PubMed1977

Effect of cytochalasin B on human monocyte binding and sphering of IgG-coated human erythrocytes.

The ability of human mononuclear phagocytic cells to bind IgG-coated human erythrocytes (EA) and to cause bound EA to become osmotically fragile (sphered) was investigated in the presence of cytochalasin B, a known inhibitor of phagocytosis. Cytochalasin B inhibited the binding of EA to mononuclear cells in a dose-dependent fashion; 80% inhibition of binding was observed at a concentration of 5 mug/ml. This profound effect on EA binding together with presently available data suggested a role for IgG receptor mobility in the macrophage binding of IgG-coated erythrocytes. Cytochalasin B, however, had a minimal effect on the capacity of mononuclear cells to sphere adherent EA, suggesting that the processes involved in macrophage-induced spherocytosis may differ from those operable in phagocytosis.

Cell Adhesion↗
PubMed1976

Concanavalin A-mediated binding and sphering of human red blood cells by homologous monocytes.

Human red blood cells sensitized with concanavalin A became bound to homologous peripheral blood monocytes. Binding occured at a concentration of 10(5) molecules of tetrameric Con A per red blood cell (RBC) and increased with additional Con A. RBC binding began within 5 min and was maximal at 90 min. Phagocytosis of sensitized RBCs was minimal. RBC attachment was prevented by 0.01 M alpha-methyl-D-mannopyranoside, and, once the RBC-monocyte rosette was established, bound RBCs were largely removed with this specific saccharide inhibitor of Con A. RBCs attached to monocytes became spherocytic and osmotically fragile. The recognition of concanavalin A (Con A)-coated RBCs was not mediated through the monocyte IgG-Fc receptor. These studies demonstrate that, like IgG and C3b, Con A is capable of mediating the binding of human RBCs to human monocytes. Red cells so bound are damaged at the monocyte surface.

Binding Sites↗