PubMed Health⌕ Search

Biomedical subjects

B R Andersen

Publications and source records attributed to B R Andersen.

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

Characterization of canine neutrophil granules.

The purpose of this study was to isolate distinct populations of canine neutrophil granules and to compare them with neutrophil granules from other species. Size, shape, density, and content of canine neutrophil granules were determined. Neutrophils obtained by Ficoll-Hypaque sedimentation were homogenized, and granule populations were separated by isopycnic centrifugation on a linear sucrose gradient (rho, 1.14 to 1.22 g/ml). The most dense granule population (rho, 1.197 g/ml) contained all of the myeloperoxidase, beta-glucuronidase, and elastase, more than half of the acid beta-glycerophosphatase, and most of the lysozyme. The population with intermediate density (rho, 1.179 g/ml) contained lactoferrin, vitamin B12-binding protein, and the remainder of the acid beta-glycerophosphatase and lysozyme. The least dense granule population did not contain a major peak of any of the enzymes or binding proteins tested but was distinguished by density and morphology. The size and shape of the granules were determined from scanning electron micrographs and assessment of shape was aided by transmission electron micrographs. By these methods three populations of canine neutrophil granules were characterized and named: myeloperoxidase granules, vitamin B12-binding protein granules, and low-density granules.

Animals↗
PubMed1982

Nosocomial outbreak of nitrate-negative Serratia marcescens infections.

Bacteremia due to multiply-antibiotic-resistant Serratia marcescens occurred within 1 week in four patients who were in adjacent beds in an intensive care unit. The strains were serotyped as O14:H12 and were nitrate negative. This unusual biochemical marker was useful in the investigation of the outbreak.

Aged↗
PubMed1981

The effects of arachidonic and other fatty acids on canine neutrophil metabolism.

The effect of arachidonic acid on the metabolic activity and chemiluminescence of canine neutrophils was investigated to gain further insight into its role in the neutrophil metabolic burst. Arachidonic acid was found to stimulate metabolic activity and luminol-augmented chemiluminescence. The increased metabolic activity was detected by both oxygen uptake measurements and assays of hexose monophosphate shunt activity. An inhibitor of lipoxygenase and cyclooxygenase, 5, 8, 11, 14-eicosatetraynoic acid prevented the hexose monophosphate shunt response to arachidonic acid. Aspirin or indomethacin, blockers of cyclooxygenase, inhibited chemiluminescence but failed to block the metabolic response to arachidonic acid. Since superoxide dismutase and 2-deoxyglucose, a blocker of glucose metabolism, inhibited the chemiluminescent response of neutrophils to arachidonic acid, it is likely that oxygen radicals produced via the hexose monophosphate shunt are required for the chemiluminescent reaction. In addition it was found that inhibition of cyclooxygenase activity blocked chemiluminescence but not the metabolic stimulation induced by sodium fluoride, suggesting that the chemiluminescence stimulated by sodium fluoride is associated with endogenous fatty acid stores. From these studies it can be concluded that arachidonic acid products of the cyclooxygenase pathway do not play a significant role in the metabolic response of neutrophils when arachidonic acid or sodium fluoride is the stimulant while the lipoxygenase pathway appears to be involved. The metabolic response is not linked to the chemical reaction that caused neutrophil chemiluminescence, although the chemiluminescent response depends on hexose monophosphate shunt activity and presumably the oxygen radicals that ultimately result from that process.

Animals↗
PubMed1981

Stimulation of human and canine neutrophil metabolism by amphotericin B.

The effect of an antifungal agent, amphotericin B, on human and canine neutrophil metabolism was studied. Commercial preparations of amphotericin B in concentrations ranging from 5 to 100 micrograms/ml stimulated neutrophil chemiluminescence in the presence of 10(-8) M luminol. This response was blocked by 2-deoxyglucose, a metabolic inhibitor, and by the absence of extracellular calcium ions. Neither pure amphotericin B nor the solubilizing agent present in the commercial preparation, alone or in combination, stimulated neutrophil chemiluminescence. Commercial amphotericin B caused an increase in oxygen uptake by neutrophils but no detectable superoxide anion production. Neutrophils were injured by commercial amphotericin B, as shown by an increase in trypan blue dye uptake but not cell lysis. Binding of amphotericin B to neutrophil membrane sterol with a subsequent alteration in membrane configuration is the most likely cause of metabolic stimulation.

Amphotericin B↗
PubMed1980

Activation of human neutrophil metabolism by streptolysin O.

The effect of streptolysin O on the metabolic activity of human neutrophils was examined. Streptolysin O, within the range of 3 to 75 hemolytic units, stimulated neutrophils to emit light. This chemiluminescence was the result of metabolic activation, as confirmed by oxygen uptake studies and the suppression of chemiluminescence by the metabolic inhibitor, 2-deoxyglucose. Free cholesterol, which prevents streptolysin O from binding to membrane cholesterol, blocked the neutrophil chemiluminescent response to streptolysin O. Extracellular calcium ions were necessary for the streptolysin O-stimulated chemiluminescent response of neutrophils. Some cell viability was lost, as measured by trypan blue uptake and neutrophil lysis within the range of streptolysin O concentration that caused metabolic stimulation. These observations suggest a possible role for streptolysin O as a pathogenic factor in streptococcal infections.

Calcium↗
PubMed1979

Defective initiation of oxidative metabolism in polymorphonuclear leukocytes.

The polymorphonuclear leukocytes of a two-year-old boy who had multiple episodes of bacterial infections demonstrated defective oxidative metabolism with phagocytic, but not with soluble (non-phagocytic), metabolic stimuli. We used a chemiluminescence assay to examine the patient's polymorphonuclear leukocyte responses to numerous particulate and soluble stimuli. The patient's polymorphonuclear leukocytes had substantially depressed chemiluminescent responses during phagocytosis of opsonized particles (latex, pneumococci, pseudomonas, streptococci and zymosan); however, we observed normal chemiluminescent responses when these leukocytes were stimulated with soluble agents (sodium fluoride, concanavalin A, cytochalasin E, calcium ionophore A23187 or phorbol myristate acetate). Polymorphonuclear leukocyte oxygen consumption and superoxide production were impaired during phagocytosis, even though phagocytosis was normal. In addition to the metabolic defect, this patient's polymorphonuclear leukocytes had depressed chemotactic and bactericidal activities. This study provides evidence that polymorphonuclear leukocytes have more than one mechanism for initiating oxidative metabolism.

Blood Bactericidal Activity↗
PubMed1979

Light generation with Fenton's reagent. Its relationship to granulocyte chemiluminescence.

A simple chemical system consisting of FeSO4 and H2O2 (Fenton's reagent) was shown to emit light (chemiluminescence). The addition of tryptophan to the reaction markedly enhanced light production. Very little chemiluminescence was observed when H2O2 was omitted from the reaction and when ferric, instead of ferrous, ions were used. Hydroxyl radical (OH.) and singlet oxygen (1 deltagO2) quenchers suppressed chemiluminescence of the FeSO4 + tryptophan + H2O2 system; and, deuterium oxide (2H2O) enhanced chemiluminescence of both FeSO4 reactions. These observations suggest that a radical chain reaction involving both OH. and 1 deltag O2 is responsible for the chemiluminescent reactions. Six iron-containing proteins, some of which are located within granulocytes, all emitted light in the presence of H2O2. Since iron and H2O2 are present in metabolically stimulated granulocytes, it is likely that chemiluminescent reactions similar to the ones demonstrated in this study account for part of the chemiluminescence of activated granulocytes.

Chemical Phenomena↗
PubMed1979

Failure of trimethoprim/sulfamethoxazole in invasive Nocardia asteroides infection.

A case of pulmonary nocardiosis occurred with progressive involvement of the pleura, pericardium, mediastinum, and sternum. Surgical resection and drainage procedures followed by administration of the drug combination, trimethoprim/sulfamethoxazole, over a six-month period led to clinical recovery. Discontinuation of drug therapy, however, was followed by relapse and further invasion by the same organism. A literature survey of Nocardia asteroides infections treated with trimethoprim/sulfamethoxazole disclosed that posttreatment follow-up is often too brief or unknown, making the ultimate success of therapy uncertain.

Administration, Oral↗
PubMed1978

Chemically shifted singlet oxygen spectrum.

The estimated light emission spectrum was determined for a singlet oxygen (1O2)-producing system, NaOCl + H2O2, alone and in the presence of tryptophan and bovine serum albumin. Tryptophan and bovine serum albumin caused a decrease in the red emission of 1O2 and an increase in the amount of shorter wavelength light. This effect was due to chemiluminescence rather than fluorescence. Arachidonic acid caused a similar spectral shift, while guanosine demonstrated a late chemiluminescent reaction of predominantly short wavelength light in the presence of 1O2.

Hydrogen Peroxide↗
PubMed1978

Use of a unique chemiluminescence spectrometer in a study of factors influencing granulocyte light emission.

Factors contributing to variability in chemiluminescence (CL) measurements of phagocytizing granulocytes were identified and controlled. Observed CL was decreased by light quenching caused by red blood cells, hemoglobin, phagocytizable particles, and granulocytes. Increases in CL were achieved by opsonization with heat labile and heat stable (antibody) serum factors, reaction temperatures in the range of 37-40 degrees C, and mixing. The effects of controlled temperature variation and mixing were studied with a chemiluminescence spectrometer uniquely designed for such studies. Features of this spectrometer which make it more suitable than the previously employed scintillation spectrometers for the observation of granulocyte and other chemiluminescent systems include; (1) the ability to measure CL immediately upon reaction initiation; (2) simplicity of photomultiplier tube exchange; and (3) built-in optical filter holders for spectral analysis.

Animals↗
PubMed1978

Chemiluminescence of human and canine polymorphonuclear leukocytes in the absence of phagocytosis.

Polymorphonuclear leukocytes (PMNs) have increased oxidative metabolism during phagocytosis and emit light (chemiluminescence, CL) as a result of metabolic activation. The present study examined PMN CL in the absence of phagocytosis using sodium fluoride (NaF), a nonparticulate agent and known stimulator of cellular oxidative metabolism. Normal human and canine PMNs were assayed in a CL spectrometer which permitted continuous sample mixing and constant temperature regulation during CL measurement. PMNs treated with 20 mM NaF demonstrated maximum CL responses of 10,000-20,000 cpm above background, 13-17 min after addition of NaF at 37 degrees C. Temperature regulation of reaction mixtures was found to be a critical factor in assaying PMN CL responses to NaF, because a small decrease in temperature (i.e. 1.5 degrees C) substantially depressed and delayed the CL response. Superoxide anion production correlated closely with CL responses in NaF-treated human PMNs. CL responses were completely suppressed in the presence of the oxidative metabolic inhibitors, iodoacetamide, and N-ethylmalemide; and were partially suppressed in the presence of either superoxide dismutase or sodium azide.CL responses of NaF-treated PMNs were significantly lower than responses generated by PMNs phagocytizing opsonized yeast. When NaF was evaluated for its effect on light generation from a singlet oxygen dependent CL reaction, it was found that NaF did not quench singlet oxygen light. This study demonstrates that PMN CL can occur in the absence of phagocytosis, and it proposes that a nonphagocytic PMN CL assay may be useful in evaluating leukocyte metabolic defects.

Animals↗
PubMed1978

Efficacy of granulocyte transfusions in the control of systemic candidiasis in the leukopenic host.

An experimental canine model was designed to evaluate the effect of granulocyte transfusions on systemic infection with Candida albicans in the granulocytopenic host. Each of a pair of dogs was rendered granulocytopenic with a single intravenous (i.v.) dose of cyclophosphamide (50 mg/kg body weight) and challenged with 10(6) Candida albicans organisms administered i.v. when granulocyte counts were less than or equal to 500/mm3. Granulocytes procured by leukofiltration were infused into six experimental dogs 1, 24, 48, and 72 hr after challenge with Candida. An average of 13 +/- 1.3 X 10(9) granulocytes were administered per infusion, producing an average 1-hr increment of 588 +/- 146 granulocytes/mm3 over the pretransfusion granulocyte count. Experimental and control dogs were killed 96 hr after challenge and organs examined grossly and by quantitative culture techniques to measure the extent of infection. All animals receiving granulocyte transfusions had significantly less tissue infection than nontransfused controls (p less than 0.05). It was concluded that granulocyte transfusions are effective in reducing the severity of infection by Candida albicans during periods of leukopenia.

Animals↗
PubMed1977

Chemiluminescence spectra of human myeloperoxidase and polymorphonuclear leukocytes.

The light emission spectra of myeloperoxidase-H2O2-Cl- and phagocytizing polymorphonuclear leukocytes were estimated by a computer simulation technique by using light transmittance data from nine band-pass filters. No shift in the chemiluminescence spectrum of either system was observed during the course of the reactions, suggesting that the light-generating mechanisms remain constant after their initiation. Transmittances were virtually identical for both myeloperoxidase-H2-O2-Cl- and polymorphonuclear leukocyte reactions, suggesting that the light-generating mechanisms are identical and leading to the estimation of nearly identical spectra. Both spectra were broad, with maximum light emission near 570 nm.

Computers↗