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Biomedical subjects

J E Repine

Publications and source records attributed to J E Repine.

At least 217 records · Page 12Linked to original sources

An improved nitroblue tetrazolium test using phorbol myristate acetate-coated coverslips.

The endotoxin--nitroblue tetrazolium (NBT) slide test was modified by precoating coverslips with phorbol myristate acetate instead of endotoxin. The percentage of control polymorphonuclear leukocytes reducing NBT was significantly (P less than .05) greater on phorbol myristate acetate-coated coverslips (99 +/- 0.21%) than on endotoxin-coated coverslips (96+/- 1.8%). Polymorphonuclear leukocytes from patients with chronic granulomatous disease did not reduce NBT on phorbol myristate acetate- or endotoxin-treated coverslips. NBT reduction by polymorphonuclear leukocytes from proven heterozygotic carriers of sex-linked chronic granulomatous disease was intermediate between NBT reductions by those from controls and patients. A statistically significant abnormality of NBT reduction was found in polymorphonuclear leukocytes from one carrier of chronic granulomatous disease with phorbol myristate acetate-treated, but not endotoxin-treated coverslips. The phorbol myristate acetate-NBT coverslip technic is a rapid, simple, reliable way to detect deficiencies in polymorphonuclear leukocytes from patients and carriers of chronic granulomatous disease.

Chemical Phenomena↗

Production of hydroxyl radical by human alveolar macrophages.

Stimulated human alveolar macrophages were demonstrated to oxidize B-methyl proprionaldehyde (methional) or 2-keto-4-thiomethylbutyric acid to ethylene (C2H4). Agents which are believed to scavenge the hydroxyl radical (.OH), sodium benzoate, and mannitol, as well as scavengers of superoxide anion (O2-) or hydrogen peroxide, decreased C2H4 production, implicaing .OH as the oxidizing radical. Differences in C2H4 rpoduction, as well as oxygen uptake and O2- release between human alveolar macrophages and polymorphonuclear leukocytes, were also documented.

Aldehydes↗

Defective oxidative metabolic responses in vitro of alveolar macrophages in chronic granulomatous disease.

After stimulation with bacteria, alveolar macrophages (AM) from uninfected normal subjects or persons with pneumonia approximately doubled their rates of O2 consumption, superoxide anion generation, and glucose (1(-14)C) oxidation. In contrast, bacteria-stimulated AM from a patient with chronic granulomatous disease (CGD) failed to consume more O2, make superoxide anion, or oxidize glucose. In addition, AM from the patient with CGD did not respond to stimulation by a chemical agent, phorbol myristate acetate, which increased the metabolic activities of AM from control subjects. The appearance, esterase and Gomori acid phosphatase staining, phagocytic ability, unstimulated O2 consumption, and response to methylene blue of AM from the CGD patient were normal. The results extend the biochemical defect in patients with CGD beyond abnormalities in their circulating neutrophils and monocytes, to their tissue-associated lung macrophages. The results also indicate that AM from patients with CGD may have an additional abnormality in metabolism, which is a lack of enhanced mitochondrial respiration during phagocytosis. The studies also document the selective action of phorbol myristate acetate, which stimulated the metabolic activities of normal AM, but not of those from the patient with CGD.

Adolescent↗

Generation of hydroxyl radical by enzymes, chemicals, and human phagocytes in vitro. Detection with the anti-inflammatory agent, dimethyl sulfoxide.

Methane (CH(4)) production from the anti-inflammatory agent, dimethyl sulfoxide (DMSO), was used to measure .OH from chemical reactions or human phagocytes. Reactions producing .OH (xanthine/xanthine oxidase or Fe(++)/EDTA/H(2)O(2)) generated CH(4) from DMSO, whereas reactions yielding primarily O-(2) or H(2)O(2) failed to produce CH(4). Neutrophils (PMN), monocytes, and alveolar macrophages also produced CH(4) from DMSO. Mass spectroscopy using d(6)-DMSO showed formation of d(3)-CH(4) indicating that CH(4) was derived from DMSO. Methane generation by normal but not chronic granulomatous disease or heat-killed phagocytes increased after stimulation with opsonized zymosan particles or the chemical, phorbol myristate acetate. Methane production from DMSO increased as the number of stimulated PMN was increased and the kinetics of CH(4) production approximated other metabolic activities of stimulated PMN. Methane production from stimulated phagocytes and DMSO was markedly decreased by purportedly potent .OH scavengers (thiourea or tryptophane) and diminished to lesser degrees by weaker .OH scavengers (mannitol, ethanol, or sodium benzoate). Superoxide dismutase or catalase also decreased CH(4) production but urea, albumin, inactivated superoxide dismutase, or boiled catalase had no appreciable effect. The results suggest that the production of CH(4) from DMSO may reflect release of .OH from both chemical systems and phagocytic cells. Interaction of the nontoxic, highly permeable DMSO with .OH may explain the anti-inflammatory actions of DMSO and provide a useful measurement of .OH in vitro and in vivo.

Cells, Cultured↗

The Chediak-Higashi syndrome: quantitation of a deficiency in maximal bactericidal capacity.

The maximum bactericidal capacity of neutrophils from a patient with the Chediak-Higashi syndrome (CHS) was measured by a quantitative assay in which the neutrophils were challenged with increasing multiples of Staphylococcus aureus, 502A. At various bacterial challenges from 0.5 to 65 bacteria per neutrophil, the CHS cells killed normal numbers of bacteria in 60 minutes. However, at higher ratios with a mean of 118 bacteria per neutrophil, the percentage of bacteria killed in 60 minutes by CHS neutrophils (8.1 +/- 2.3%) was significantly less (P < 0.001) than that killed by normal neutrophils (44 +/- 2.3%). The CHS neutrophils lagged in their ability to kill low challenges of bacteria (0.5 or 1.2 bacteria per neutrophil) only at 20 minutes. A hydrogen-peroxide-producing strain of Streptococcus faecalis was killed normally by the CHS neutrophils at 60 minutes, with all ratios of challenge up to 114 to 1. Electron microscopic examination of 60-minute specimens from high ratios of challenge that were stained for myeloperoxidase activity revealed a failure of many bacteria-laden phagosomes to display this marker of degranulation. The results of this study indicate that the maximal bactericidal capacity of CHS neutrophils is saturated by a significantly lower challenge of bacteria than is required to saturate normal cells. This appears to be the result of sequestration of a significant portion of these cells' bactericidal resources in the giant granules that do not participate appreciably in degranulation.

Adolescent↗

Influence of cationic local anesthetics on the metabolism and ultrastructure of human alveolar macrophages.

The concentrations of cationic local anesthetics present in effluents from subsegmental bronchoscopic lavage were determined. Subsequently, the effect of these agents on lavaged human AM was evaluated in vitro. The results indicate that concentrations of LDC that may alter human AM function are present in effluents during routine subsegmental bronchopulmonary lavage. LDC and TRC in a dose-dependent fashion rapidly inhibited oxygen consumption and superoxide anion (O-2.) release by unstimulated human AM or AM stimulated by bacteria or the membrane-active chemical PMA. Concentrations of 2 mM TRC or 16 mM LDC reduced O2 consumption and O-2. release by unstimulated AM by more than 70% and blocked the usual spurt in O2 uptake and O-2. release observed for stimulated AM. This inhibition was not due to cytotoxicity, since washing n a balanced salt solution restored the metabolic function of treated AM. TRC or LDC also had effects on the morphology of washed human AM, causing rounding of the cell surface (scanning electron microscopy). In summary, the findings show that anesthetic agents routinely present in lavage effluents have the capacity to alter the function and structure of human AM. Although the effect must be considered in the design and interpretation of studies using AM obtained by bronchopulmonary lavage, the cationic anesthetics may also prove to be valuable agents for evaluating cell membrane-related events of human AM.

Anesthetics, Local↗

Defective neutrophil locomotion in human blastomycosis: evidence for a serum inhibitor.

Unstimulated or stimulated locomotion, bactericidal, and metabolic activities of polymorphonuclear leukocytes (PMN) from 12 nonimmunosuppressed patients with invasive fungal infections proved by culture, were evaluated before and after treatment of the patients with antimicrobial drugs. The major observation was that PMN from patients with blastomycosis had a defect in stimulated locomotion. The specificity of the defect for blastomycosis was substantiated by the normal stimulated locomotion of PMN from uninfected control subjects or untreated patients with histoplasmosis, cryptococcosis, coccidioidomycosis, or sporotrichosis. The defect was due to a heat-stable, cell-directed, reversible serum inhibitor. In unheated or heated serum from untreated patients with blastomycosis, control PMN had decreased stimulated locomotion. Multiple washing followed by addition of control serum corrected locomotion of PMN from untreated patients with blastomycosis. The abnormality was not present in PMN from patients who had been treated with amphotericin B or had spontaneous resolution of their infections. Inhibition was not due to absence of chemoattractant activity because zymosan-activated patient serum or mixtures of patient and control serum stimulated PMN locomotion normally. The defect did not correlate with age, sex, neutrophil count, nitroblue tetrazolium reduction, serologic reactivity, or duration or severity of infection. No defect was found in bactericidal or metabolic activities of various combinations of PMN and serum from untreated or treated patients with blastomycosis or the 4 other fungal infections tested, indicating that the inhibitor was specific for stimulated locomotion.

Adolescent↗

Reversible impairment of the adherence of alveolar macrophages from cigarette smokers.

The nylon fiber adherence in vitro of alveolar macrophages (AM) from cigarette smokers was uniformly decreased. The mean adherence of AM from 16 cigarette smokers was 53 +/- 3.0 per cent, compared to a mean adherence of 77.2 +/- 1.7 per cent for AM from control nonsmokers. The defect was not present after the subjects quit smoking, was not a result of factors in lavage fluids from smokers, and was not apparent in polymorphonuclear leukocytes. The morphologic features of the surface of AM were examined with scanning electron microscopy to determine whether morphologic changes paralleled the decreased adherence of AM from smokers. Marked alterations in the surface of AM from cigarette smokers, which could affect the ability of AM to adhere optimally, were demonstrated before attachment to the fiber. In summary, there exists a reversible, intrinsic defect in the structure and adherence of AM from cigarette smokers that may influence their function and may accout, in part, for the increased yield of AM from the lavage fluid of cigarette smokers.

Cell Adhesion↗

The effect of phorbol myristate acetate on the metabolism and ultrastructure of human alveolar macrophages.

In the present investigation we examined the influence of the surface-active agent phorbol myristate acetate (PMA) and opsonized heat-killed bacteria (HKB) on oxygen consumption, superoxide release, and glucose oxidation of human alveolar macrophages (AM). Both PMA and HKB produced a surge in oxygen consumption, superoxide release, and oxidation of 1-14C-glucose and 6-14C-glucose by human AM. Examination of AM by electron microscopy following stimulation by these two agents demonstrated membrane ruffling, loss of microvilli, and increased vacuolization in PMA-treated cells and phagocytic vacuoles containing bacteria in HKB-treated cells. The vacuolization produced by PMA-treated AM was much less striking than the vacuolization produced in PMA-treated leukocytes. The similarity in the metabolic and some of the physical responses of AM stimulated by PMA and HKB suggest that PMA may be a useful agent for evaluating cell-membrane-related events of phagocytosis in AM.

Cell Membrane↗

Inhibition of human neutrophil oxidative metabolism and degranulation in vitro by nitroblue tetrazolium and vitamin E.

The effect of a mixture of nitroblue tetrazolium (NBT) and vitamin E on the metabolism and ultrastructure of polymorphonuclear leukocytes (PMN) from normal subjects or patients with chronic granulomatous disease (CGD) was determined in vitro. Increasing concentrations of NBT and vitamin E progressively decreased rates of oxygen consumption and 1-14C-glucose oxidation by normal PMN stimulated with particulates to a degree that exceeded either agent alone. NBT-vitamin-E also inhibited vacuole formation and the cytochemical release of myeloperoxidase-positive granules. The depressed oxidative metabolism and degranulation of NBT-vitamin-E-treated control PMN closely approximated the blunted responses of CGD PMN which were similar alone or in the presence of NBT-vitamin-E. In contrast to these effects, the highest concentration of NBT-vitamin-E used in the study did not damage, decrease rates of unstimulated oxidative metabolism of, or impair ingestion of particulates by control or CGD PMN. NBT and vitamin E impose a state on normal PMN which is remarkably similar to that observed in PMN from patients with CGD.

Glucose↗

Fine structural alterations induced in erythocytes by phorbol myristate acetate.

Prevous studies have demonstrated that PMA is a potent membrane-active agent causing cell-wall derived vacuole formation in neutrophils and granule labilization in platelets. The present investigation demonstrates that PMA also has marked effects on red blood cells. Erythrocytes exposed to PMA were converted into stomatocytes and stomatospherocytes. The effects of PMA on red cells were concentration-dependent, required removal of plasma, and occurred maximally at 37 C. Although the response of the red cell to PMA was not identical to that of other blood cells tested previously; the similarities suggest that the capacity of the agent to produce membrane invagination may be fundamental to its mode of action.

Cell Membrane↗

The Chédiak-Higashi syndrome. Evidence that defective leukotaxis is primarily due to an impediment by giant granules.

The primary defect of the Chédiak-Higashi syndrome (CHS) which links the several known neutrophil abnormalities in this disorder remains enigmatic. In an attempt to clarify the mechanism of one of the abnormalities of CHS neutrophils, ie, chemotactic migration, the effect of filter pore size was examined in the standard Boyden chamber assay. The response of normal neutrophils to a gradient of zymosan-activated serum was not influenced by increasing the filter pore size from 5 to 8 microgram. However, while CHS neutrophils showed a significant reduction in migratory response from the controls with 5-mu filters, the difference was eliminated when 8-mu filters were employed. Again, when an arachidonic acid gradient was used as the stimulus, migration of CHS neutrophils through 8-mu filters equalled that of controls. These findings indicate the intact nature of the surface receptor and motility systems of the CHS neutrophils and further suggest that the previously defined chemotactic defect in these cells can be explained in terms of the mechanical impediment provided by the CHS giant cytoplasmic granules.

Chediak-Higashi Syndrome↗

Comparison of the metabolism of alveolar macrophages from humans, rats, and rabbits: phorbol myristate acetate.

Metabolic activities of unstimulated or stimulated AMs from humans, rats, and rabbits were examined and compared in vitro. Rates of oxygen consumption, chemiluminescence, and glucose (1- or 6-14C) oxidation by unstimulated AMs from these three species increased following stimulation of the AMs by bacteria or PMA. Although the absolute metabolic responses of AMs from humans, rats, or wild rabbits were different, the metabolic activities from each species were nearly identical when compared on the basis of protein content of the cells. In contrast to the enhanced biochemical responses of AMs from humans, rats, or wild rabbits, stimulated AMs from certain commercially supplied rabbits failed to increase their metabolism. The failure of AMs from these rabbits to respond metabolically was probably due to an acquired abnormality resulting from their care and storage at the supplier. The defect was associated with the presence of large numbers of Bordetella bronchiseptica organisms in the lavage effluents from these commercially supplied rabbits. This abnormality in metabolism of AMs was reversed following prolonged residence of the rabbits in the laboratory, and the correction of the defect was accompanied by a disappearance of B. bronchiseptica from the lavage fluid. The results comprehensively compare and contrast the metabolism of AMs from humans and animals and emphasize the need to document the appropriateness of animal models before using them to predict biologic reactions of humans.

Animals↗