PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Phagocyte Bactericidal Dysfunction”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1989

Evaluation of a fluorochrome assay for assessing the bactericidal activity of neutrophils in human phagocyte dysfunctions.

We evaluated a method for the assessment of the phagocytic and bactericidal activity of human peripheral neutrophils against Staphylococcus aureus Cowan I, which is a modified version of the acridine orange staining technique originally described by Smith and Rommel (1977). The modification consisted of the use of free leukocyte suspensions rather than coverglass adhered leukocytes in order to avoid two main problems: the inefficient neutrophil adherence to glass that can be observed in specimens from patients with certain functional phagocyte defects, and the risk of selecting among neutrophils. An additional advantage of the modified procedure is that it permits a uniform bacteria: phagocyte ratio in different cell samples. The method was tested on 25 healthy adults and on four children with functional phagocytic defects (chronic granulomatous disease of infancy, Chediak-Higashi syndrome, and Rothmund-Thomson syndrome associated to persistent neutropenia and low chemotactic response). The neutrophils of all four patients showed a low bactericidal activity, with percent values of intracellular killed bacteria below the mean +/- 2 SD range observed in the healthy population at all incubation times tested (5, 15 and 30 min). A significant reduction in phagocytosis index and in % killed unopsonized S. aureus was observed in relation to bacteria treated with a pool of normal human serum. These results demonstrate the high sensitivity of the method, which could be used to determine intrinsic and extrinsic functional alterations in human neutrophils.

Acridine Orange↗
PubMed1973

Granulocytopathies.

Explore the source record for details and available documents.

Arthritis, Rheumatoid↗
PubMed1983

Persistent mandibular infection in three patients with lazy and incompetent phagocyte syndromes.

Three patients with the lazy phagocyte syndrome suffered from recurrent infections in the orofacial region which persisted despite treatment with antibiotics. All had neutrophil counts at the lower normal limits which did not increase after strenuous exercise or rise during infections. Tests of chemotaxis, random mobility and the skin window were abnormal. Ingestion and intracellular killing, however, were normal in one patient and abnormal in two. The findings are compatible with the lazy leucocyte syndrome but the symptoms were not manifest in early childhood as originally described by Miller et al. (1971), and the neutrophil counts were not as low as in his patients. Two of our patients also differed in showing a defective intracellular killing for Candida albicans. The lazy leucocyte syndrome should now be recognized to include different variants, some with late onset, a range in the degree of neutropenia, and some with defective ingestion and killing, though all possess a basic intrinsic defect of movement.

Adult↗
PubMed1975

The role of superoxide anion generation in phagocytic bactericidal activity. Studies with normal and chronic granulomatous disease leukocytes.

The capacity of human phagocytes to generate superoxide anion (O2-), a free radical of oxygen, and a possible role for this radical or its derivatives in the killing of phagocytized bacteria were explored using leukocytes from normal individuals and patients with chronic granulomatous disease (CGD). Superoxide dismutase, which removes O2-, consistently inhibited phagocytosis-associated nitroblue tetrazolium (NBT) reduction indicating the involvement of O2- in this process. Similarly, superoxide dismutase inhibited the luminescence that occurs with phagocytosis, implicating O2- in this phenomenon, perhaps through its spontaneous dismutation into singlet oxygen. Subcellular fractions from homogenates of both normal and CGD leukocytes generated O2- effectively in the presence of NADH as substrate. However, O2- generation by intact cells during phagocytosis was markedly diminished in nine patients with CGD. Leukocytes from mothers determined to be carriers of X-linked recessive CGD by intermediate phagocytic reduction of NBT elaborated O2- to an intermediate extent, further demonstrating the interrelationship between NBT reduction and O2- generation in phagocytizing cells. Activity of superoxide dismutase, the enzyme responsible for protecting the cell from the damaging effects of O2-, was approximately equal in homogenates of normal and CGD granulocytes. Polyacrylamide electrophoresis separated this activity into a minor band that appeared to be the manganese-containing superoxide dismutase associated with mitochondria and a more concentrated, cyanide-sensitive, cytosol form of the enzyme with electrophoretic mobility that corresponded to that of erythrocyte cuprozinc superoxide dismutase. Superoxide dismutase inhibited the phagocytic killing of Escherichia coli, Staphylococcus aureus, and Streptococcus viridans. A similar inhibitory effect was noted with catalase which removes hydrogen peroxide. Neither enzyme inhibited the ingestion of bacteria. Peroxide and O2- are believed to interact to generate the potent oxidant, hydroxyl radical (.OH). A requirement for .OH in the phagocytic bactericidal event might explain the apparent requirement for both O2- and H2O2 for such activity. In agreement with this possibility, benzoate and mannitol, scavengers of .OH, inhibited phagocytic bactericidal activity. Generation of singlet oxygen from O2- and .OH also might explain these findings. It would seem clear from these and other studies that the granulo cyte elaborates O2- as a concomitant of the respiratory burst that occurs with phagocytosis. To what extent the energy inherent in O2- is translated into microbialdeath through O2- itself, hydrogen peroxide, .OH, singlet oxygen, or some other agent remains to be clearly defined.

Catalase↗