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Biomedical subjects

D Munster

Publications and source records attributed to D Munster.

8 recordsLinked to original sources

Identification of formyl Met-Leu-Phe in culture filtrates of Helicobacter pylori.

Helicobacter pylori synthesizes and secretes a substance which co-chromatographs and is antigenically cross-reactive with the bacterial chemotactic peptide fMet-Leu-Phe. Using reverse phase and affinity chromatography this substance has now been purified. Carboxypeptidase Y microsequencing has verified that this material is fMet-Leu-Phe. The infiltration of polymorphonuclear leucocytes to sites of H. pylori infection may be a response to mucosal permeation of soluble, diffusable bioreactive substances such as fMet-Leu-Phe.

Amino Acid Sequence

Neutrophil activation by Helicobacter pylori.

Helicobacter pylori infection of the stomach is accompanied by a persistent polymorphonuclear leukocyte (PMNL) infiltrate of the mucosa. The aim of this work was to study the activation of human PMNL by substances produced by H pylori. Filtered H pylori conditioned media stimulated a significant PMNL oxidative burst (p less than 0.002). This was equal to 26% of the maximal response stimulated by the PMNL chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP, 1 mumol/l). The response to FMLP was prolonged by the combined presence of complement inactivated human anti-H pylori plasma and conditioned medium (p less than 0.002). High pressure liquid chromatography of an extract of conditioned medium showed a fraction that stimulated PMNL, eluted, and antigenically cross reacted with FMLP. Washed H pylori cells, and those opsonised with complement inactivated human anti-H pylori plasma, did not induce a significant oxidative burst. Opsonized H pylori, however, prolonged the oxidative burst induced by FMLP (p less than 0.02). In conclusion, H pylori synthesizes and secretes a substance, probably FMLP, that may account for the PMNL accumulation that accompanies H pylori infections. Immune complexes composed of H pylori antigen and specific antibody potentiate the PMNL oxidative burst. This combination of H pylori derived products, and host PMNL and antibodies, may be involved in the mucosal damage observed in H pylori associated gastritis.

Antibodies, Bacterial

Acid phosphatase in leukemic blasts: characterization by isoelectric focusing in polyacrylamide gel.

Using the high resolution technique of isoelectric focusing in polyacrylamide gel, isoenzymatic components of acid phosphatase were detected in cell-free extracts prepared from different cytologic types of leukemic blasts in adults. Results indicate that for different cytologic types, different characteristic patterns of acid phosphatase isoenzyme could be detected. These studies extend conventional cytochemistry and indicate that characteristic patterns of acid phosphatase isoenzyme can be detected for various cytologic types of acute leukemia.

Acid Phosphatase

Nonspecific esterases in leukemic blasts. Characterization by isoelectric focusing in polyacrylamide gel.

Using high-resolution technics of isoelectric focusing in polyacrylamide gel, isoenzymatic components of nonspecific esterases extracted from various cytologic types of leukemic blasts were visualized using alpha-naphthyl acetate and alpha-naphthyl butyrate as substrates. For each cytologic type of leukemic blast, consistent and distinctive patterns of nonspecific esterase activity were visualized. These studies provide further evidence for heterogeneity of nonspecific esterases, and for elaboration of isoenzymatic components as a reflection of cellular differentiation.

Esterases

Acid phosphatase in normal human blood cells: characterization by isoelectric focusing in polyacrylamide gel.

Using the high resolution technique of isoelectric focusing in polyacrylamide gel, isoenzymatic components could be discerned in acid phosphatase extracted from normal human lymphocytes, granulocytes, monocytes, and platelets. For each cell type, distinctive isoenzymatic patterns of acid phosphatase activity could be observed. These studies provide further evidence that various types of cellular differentiation are associated with differences in isoenzymatic components of acid phosphatase.

Acid Phosphatase

Nonspecific esterases in normal human blood cells: characterization of isoenzymes by isoelectric focusing in polyacrylamide gel.

Using the high resolution technique of isoelectric focusing in polyacrylamide gel, isoenzymatic components of nonspecific esterase were resolved in esterase-rich extracts obtained from normal human monocytes, lymphocytes, granulocytes and platelets. In the case of each cell type, different isoenzymatic patterns of nonspecific esterase activity could be visualized. These studies extend the cytochemistry of nonspecific esterases by detection of previously undescribed isoenzymatic components, and suggest that the elaboration of nonspecific esterase isoenzymes may be a function of cellular differentiation.

Blood Cells

Arginine methyltransferase activity in chronic erythremic myelosis (Diguglielmo syndrome).

Activity of S-adenosylmethionine-dependent arginine methyltransferase was substantially higher in sonicated bone marrow samples from 6 patients with chronic erythremic myelosis than in bone marrow from 3 patients with untreated pernicious anemia, 2 patients with autoimmune hemolytic anemia, and 4 normal persons. Increased activity of this enzyme may be one of the factors contributing to the pathogenesis fo methylated arginines in histones of erythroblasts from patients with chronic erythremic myelosis.

Arginine