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Biomedical subjects

P K Ray

Publications and source records attributed to P K Ray.

At least 127 records · Page 7Linked to original sources
PubMed1983

Inhibition of rat mammary tumor growth by purified protein A--a potential anti-tumor agent.

Intravenous inoculations of purified Protein A of Staphylococcus aureus Cowan I cause significant (p less than 0.01) regression of di-methyl-benz-anthracene (DMBA)-induced mammary adenocarcinomas in Sprague-Dawley rats. Direct tumor cell counts of treated tumors showed fewer (p less than 0.005) viable tumor cells than did tumors from untreated controls. Plasma immunoglobulin G concentration showed a significant (p less than 0.05) increase compared to that of controls. However, the concentration of immune complexes and percentages of T-rosettes did not change. Peripheral blood mononuclear cells (PBMNC) from treated animals showed increased cytotoxicity (p less than 0.005) compared to that of controls. Plasma of treated animals potentiated PBMNC cytotoxicity (p less than 0.05) and showed increased antibody and complement-mediated cytotoxicity (p less than 0.025). The exact mechanism of protein A-induced potentiation of anti-tumor immune reactivities leading to tumoricidal response is not known. However, our data are suggestive of the involvement of both cellular and humoral immunity of the host in the tumor regressive phenomenon.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1982

Extracorporeal immunoadsorption of plasma from a metastatic colon carcinoma patient by protein A-containing nonviable Staphylococcus aureus: clinical, biochemical, serologic, and histologic evaluation of the patient's response.

A patient with a metastatic colon carcinoma was treated by immunoadsorption (IA) therapy using heat-killed, formalin-stabilized protein A-containing Staphylococcus aureus Cowan I as the immunoadsorbent. The patient experienced both subjective and objective positive clinical response without undue morbidity. The patient's response correlated well with laboratory findings of decreased concentrations of carcinoembryonic antigen (CEA), immunoglobulin G (IgG), immune complexes (IC) and histopathologic data. The patient underwent surgery following 15 IA treatments; she lived for eighteen months, post-treatment.

Adenocarcinoma↗
PubMed1982

Mechanism of regression of mammary adenocarcinomas in rats following plasma adsorption over protein A-containing Staphylococcus aureus.

The plasma from 7,12-dimethylbenz(a)anthracene-induced mammary tumor-bearing rats was adsorbed ex vivo with nonviable protein A-containing Staphylococcus aureus Cowan I and then injected into the rats, along with its original blood cells. Tumors in the treated rats showed significant (p less than 0.005) growth inhibition. There were fewer metastatic nodules; cellular cytotoxicity in the presence of plasma was augmented, and there was increased antitumor cytotoxic antibody activity in treated rats. Plasma from sham-treated rats, however, showed blocking activity. It appears that plasma perfusion over S. aureus decreases blocking activity and augments antitumor immunoreactivity of plasma. The exact mechanism by which growth of 7,12-dimethylbenz(a)anthracene-induced mammary tumors was inhibited in these treated Sprague-Dawley rats is not known. However, it is hypothesized that the observed tumor regression is at least partly attributable to the augmentation of antitumor immunoreactivity in the treated animals.

Adenocarcinoma↗
PubMed1982

Differential binding affinity of immobilized Concanavalin A-Sepharose 4B for normal and myelomatous immunoglobulins.

Immobilized Concanavalin A-Sepharose 4B (CSB) binds myeloma immunoglobulins (IgG through IgE) in larger proportions than it binds normal immunoglobulins. Some possible explanations for this are discussed. Also, CSB shows differential affinity among immunoglobulins, normal or myelomatous; its greatest affinity is for IgM and IgE. This property can be used to separate a large percentage of the IgM and IgE from both normal and myelomatous sera.

Humans↗
PubMed1981

Specific immunoadsorption of IgG antibody in a patient with chronic lymphocytic leukemia and autoimmune hemolytic anemia. A new form of therapy for the acute critical stage.

Progressive and severe autoimmune hemolytic anemia developed in a patient with chronic lymphocytic leukemia (CLL) despite treatment with chlorambucil, high doses of corticosteroids and attempts to transfuse packed red blood cells. Splenectomy was not performed because of severe coronary artery disease. Direct antiglobulin tests revealed a warm red blood cell autoantibody of IgG-type with anti-e specificity. The patient was treated by extracorporeal immunoadsorption of plasma IgG using a cell separator and protein A as the immunoadsorbent. The patient responded by an increase in the hemoglobin levels and platelet counts after two treatments. Specificity of the procedure was shown by a decrease in the serum IgG and by the demonstration of the same reactivity to ficin-treated reagent red blood cell panel of the eluate from the protein A. Antibody titers of the patient's red blood cell eluate decreased from 1:128 to 1:64 and eventually the anti-e specificity was lost. This is a report of a novel approach to treatment of the acute phase of an autoimmune hemolytic anemia.

Adsorption↗
PubMed1981

Low-dose cyclophosphamide inhibition of transplantable fibrosarcoma growth by augmentation of the host immune response.

Preinjection of a low dose of cyclophosphamide (Cy) (500 microgram/mouse) either delayed or inhibited tumor appearance following the inoculation of transplantable 3-methylcholanthrene-induced fibrosarcomas in inbred male C3H/HeJ mice. This dose of Cy decreased the spleen weight by 13% and the total spleen cell count by 23%. However, the same dose could potentiate the footpad swelling reaction (FPSR) measured against Staphylococcus aureus antigen. Splenic lymphocytes from Cy-treated animals showed increased blastogenic response against phytohemagglutinin-M and bacterial lipopolysaccharide. Thus 500 micrograms Cy/animal may have depleted suppressor cell populations leading to: a) an increase in FPSR, b) increased blastogenic transformation of lymphocytes, and c) tumor growth inhibition.

Animals↗
PubMed1981

Ability of nonviable Staphylococcus aureus Cowan I to bind ionized calcium in vitro and ex vivo in an extracorporeal perfusion system.

During immunoadsorption of plasma immunoglobulin G (IgG) and/or its complexes, using nonviable Staphylococcus aureus Cowan I (SA) as an immunoadsorbent, we observed a consistent drop in plasma calcium during every immunoadsorption procedure. The percentage of decrease in plasma calcium was directly dependent on the amount of SA adsorbent present. Although SA can bind both IgG and calcium, the degree of binding of IgG was greater than that of calcium. Calcium could not be detected in the IgG fraction of the plasma SA, however, could bind an appreciable amount of ionized calcium. Extracorporeal perfusion of plasma over SA greatly decreased plasma calcium in a hypercalcemic patient, indicating the feasibility of this method in such patients. Questions concerning the significance of lowering calcium levels as a concomitant of other effects observed in cancer patients undergoing immunoadsorption therapy using SA evolve from the above and become a new focus for attention.

Adsorption↗
PubMed1980

Efficient removal of abnormal immunoglobulin G from plasma of a multiple myeloma patient. Description of a new method for treatment of the hyperviscosity syndrome.

Patients with multiple myeloma who have complications secondary to hyperviscosity are treated by chemotherapy and/or plasmapheresis. Because the response to chemotherapy is usually delayed, plasmapheresis is required for the removal of larger concentrations of plasma proteins to avoid life-threatening complications. Until now there has been no available means to decrease the abnormal plasma proteins in a selective manner. This report describes a new method for the selective removal of immunoglobulin G from the plasma of a patient suffering from IgG-type multiple myeloma. Results obtained from plasmapheresis and selective immunoadsorption of IgG are compared. It appears that the technique described herein may offer a new, more efficient method for the palliative treatment of diseases associated with elevated concentrations of plasma immunoglobulin G.

Adult↗
PubMed1980

Stabilization of the remaining adrenal gland following unilateral adrenalectomy. A light- and electron-microscopic study in the rat.

The effects of unilateral adrenalectomy on the contralateral adrenal gland in rats form the basis of the present communication. The project has been undertaken in an attempt to establish on ultrastructural grounds the stage at which an animal is stabilized on the solitary adrenal gland. The work is chiefly based on electron microscopy, supplemented by gross morphological and light microscopic investigations. Morphological changes in the adrenal gland after removal of the contralateral one were confined exclusively to the cortex and did not involve the medulla. The changes in the fine structure involved most of the organelles that are known to play vital roles in the biosynthesis of corticosteroid hormones, namely, mitochondria, smooth endoplasmic reticulum (SER) and lipid droplets. The ultrastructural alterations showed remarkably wide variations at different time periods after the operation. The organelles eventually reverted to normal appearances after the 2nd postoperative week. These results have been correlated with the observations of previous workers, and the significance of the present findings, particularly in relation to the functional activity of the adrenal cortex, has been discussed.

Adaptation, Physiological↗
PubMed1980

Extracorporeal immunoadsorption of myeloma IgG and autoimmune antibodies: a clinically feasible modality of treatment.

Using heat-killed, formalin-stabilized Staphylococcus aureus Cowan I suspension, it was possible to remove myeloma IgG and autoimmune anti-red blood cell antibodies from two patients' plasma following an extracorporeal procedure. The arterial anticoagulated blood was processed through a cell separator machine. The separated plasma was pumped through a bacterial filter containing S. aureus suspension. The adsorbed plasma was then reunited with the blood cells and returned to the patient through the vein. S. aureus Cowan I could selectively remove the myeloma IgG and autoimmune anti-red cell antibodies from the patients' plasma prolonging the lives of these two terminal patients. The immunoadsorption procedure appears to be a safe, practical and quick method for the removal of pathological IgG from the patients' plasma.

Adult↗