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Biomedical subjects

R Anderson

Publications and source records attributed to R Anderson.

At least 649 records · Page 36Linked to original sources

In vitro stimulation of neutrophil motility by metoprolol and sotalol related to inhibition of both H2O2 production and peroxidase mediated iodination of the cell and leucoattractant.

The effects of the beta-receptor blockading agents, metoprolol and sotalol on neutrophil random motility, chemotaxis, post-phagocytic glycolysis, superoxide production, hexose monophosphate shunt activity, myeloperoxidase (MPO) mediated protein iodination and hydrogen peroxide production were assessed in vitro. The concentration range investigated was 10(-8)--10(-2) M for each drug. Both agents caused significant stimulation of neutrophil motility at concentrations of more than 10(-4) M. Increased migration was not associated with increased glycolysis or significant cyclic nucleotide fluctuations, but was inversely related to inhibition of superoxide and hydrogen peroxide generation and MPO mediated iodination with both drugs. In a further series of experiments to determine the relationship between the drug induced inhibition of H2O2 production and MPO mediated protein iodination to stimulation of motility it was found that concentrations of sotalol and metoprolol that caused these effects prevented HRP/H2O2/I- induced inactivation of the leucoattractant and inhibition of neutrophil chemotactic responsiveness. Neither drug inhibited the activity of MPO per se nor the reduction of ferricytochrome c by superoxide generated by the xanthine: xanthine oxidase system in vitro. It is suggested that enhanced neutrophil motility is not related to beta-receptor blockade but rather to restricting the availability of hydrogen peroxide and reactive products of the MPO/H2O2/halide system.

Cell Movement↗

The effects of increasing weekly doses of ascorbate on certain cellular and humoral immune functions in normal volunteers.

Certain functions of the blood neutrophils and lymphocytes from normal adult volunteers were evaluated after the ingestion of increasing doses of ascorbate. Serum immunoglobulins and levels of C'3 and total hemolytic complement were also measured. Enhancement of neutrophil motility to a chemotactic stimulus of endotoxin-activated autologous serum was observed in normal adult volunteers after the ingestion of 2 and 3 g ascorbate daily. No alteration was observed at lower doses. Other neutrophil functions evaluated that remained unaltered by ascorbate, were postphagocytic hexose monophosphate shunt activity and myeloperoxidase mediated iodination of ingested protein. Stimulation of lymphocyte transformation to the mitogens phytohaemagglutinin and concanavalin A was detected after the daily ingestion of 1, 2, and 3 g of ascorbate. Mitogen-induced protein synthesis was unaffected. Serum levels of IgG, IgA, IgM, C'3, and C'4 and total complement activity were unaltered by ascorbate.

Adult↗

Effects of sulfamethoxazole and trimethoprim on human neutrophil and lymphocyte functions in vitro: in vivo effects of co-trimoxazole.

The effects of sulfamethoxazole and trimethoprim individually and in combination on in vitro neutrophil random migration, chemotaxis to autologous endotoxin-activated serum and the synthetic chemotactic tripeptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine, phagocytosis and postphagocytic Nitro Blue Tetrazolium reduction, glycolysis, hexose monophosphate shunt activity, myeloperoxidase-mediated protein iodination, hydrogen peroxide production, and degranulation were assessed. The effects on lymphocyte mitogen-induced transformation were also evaluated. It was found that the test agents individually and in combination at high concentrations (> 100 microgram/ml) caused the inhibition of neutrophil postphagocytic myeloperoxidase-mediated protein iodination, which was related to the interference with H2O2 formation as the enzyme per se was unaffected. Both agents caused the inhibition of lymphocyte transformation at high concentrations (> 100 microgram/ml). In vivo studies before and after the ingestion of co-trimoxazole by three individuals showed no inhibition of any of the neutrophil functions tested. The inhibition of lymphocyte transformation was observed in one individual after the ingestion of the chemotherapeutic agent. These findings indicate that the concentrations which inhibit neutrophil H2O2 production and lymphocyte transformation in vitro are not attainable in vivo.

Adult↗

Prescribed medicines: who takes what?

The number of prescribed medicines dispensed in England and Wales increased by 21% between 1969 and 1977. Surveys carried out at the Institute for Social Studies in Medical Care have been used to compare the reported consumption of prescribed medicines in those two years. Although there were some changes in the distribution of prescribed medicines between age, sex, and social class groups, there did not appear to be an increase in the use of these medicines commensurate with the increase in the number dispensed. It is suggested that a growing proportion of people may be deciding not to take their medicines as instructed.

Adolescent↗

Unusual polar lipids of Micrococcus radiodurans strain Sark.

The polar lipids of Micrococcus radiodurans strain Sark appear to be unique in that common bacterial phospholipids such as phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, and phosphatidylinositol are absent. Of the 13 polar lipids detected, 5 contain phosphorus and carbohydrate, 4 contain carbohydrate and no phosphorus, and 1 contains phosphorus as well as sulfur. None of the polar lipids contain free choline or amino groups and none are sensitive to phospholipases C or D. Of eight selected polar lipids tested, all were found to be labile to milk alkali, suggesting the presence of ester linkages. It is suggested that the unusual lipid profile of M. radiodurans strain Sark may be useful in taxonomic considerations.

Chromatography, Thin Layer↗

In vitro effects of histamine on eosinophil migration.

Histamine at concentrations of 5 X 10(-6) to 5 X 10(-5) M increased eosinophil movement to endotoxin-activated serum (EAS). This effect was due entirely to stimulation of random migration (chemokinesis). Directional motility (true chemotaxis) was inhibited by these concentrations. Regulation of chemotaxis was apparently mediated via an H2 receptor as metiamide, an H2 receptor antagonist, but not diphenylhydramine hydrochloride, an H1 receptor antagonist, blocked the histamine-induced inhibition of chemotaxis. Both histamine and metiamide when used alone had no effect on eosinophil motility. The histamine effects on motility were associated with increased levels of intracellular cAMP, whereas cGMP levels were not affected.

Cell Movement↗

An in vitro assessment of cellular and humoral immune function in pulmonary tuberculosis: correction of defective neutrophil motility by ascorbate, levamisole, metoprolol and propranolol.

Fifty-six tuberculosis patients and twenty-eight control subjects were evaluated in a comprehensive investigation of cellular and humoral immune function in pulmonary TB. The patient group showed significantly higher levels of secretory IgA and serum IgG, IgA and IgM than did the control group but 7% of patients displayed a selective secretory IgA deficiency. Levels of alpha-1-antitrypsin were also significantly higher in the patient group. There were no significant differences in levels of total haemolytic complement, C'3 and C'4. In moderate to moderately advanced TB patients there were no significant differences in T and B cell numbers nor in mitogen-induced lymphocyte transformation and lymphokine production, when compared with the control group. The range of PPD-induced lymphocyte transformation and lymphokine production levels encountered was similar in both groups although certain patients did not respond to the PPD antigen. Neutrophils from TB patients showed increased random motility in vitro but eight out of ten patients showed impaired directed motility (chemotaxis). Phagocytic and anti-microbial functions were normal in the patient group. The neutrophil chemotactic defect was reversible and could be corrected in vitro when the patients' cells were treated with sodium and calcium ascorbate, levamisole, metoprolol and propranolol.

Antibody Formation↗

Giant cell tumors of the maxilla in children.

Three types of giant cell lesions occur in the facial skeleton; namely, giant cell reparative granuloma, Brown tumor of hyperparathyroidism, and true giant cell tumor -- osteoclastoma preferably called giant cell neoplasm. An appraisal of the clinical course biochemical laboratory data, radiographic appearance, and histological features are all necessary to distinguish between these varieties. Differentiation is a prerequisite to treatment because the management differs in each lesion. Three case reports illustrate these features. The important considerations of facial growth following surgery to the facial skeleton of a child are discussed. Long-term observation is imperative.

Child↗

Effects of ascorbate on leucocytes: Part V. Effects of ascorbate and calcium and sodium ascorbate on certain functions of human blood lymphocytes in vitro.

The effects of ascorbate and calcium and sodium ascorbate at concentrations of 10(-8)M--10(-2)M on the following functions of human blood lymphocytes were investigated: mitogen-induced DNA synthesis and secreted and intracellular protein synthesis; migration towards a stimulus of endotoxin-activated serum; active E-rosette formation and lymphokine production. The mitogens used were concanavalin A (con A) and phytohaemagglutinin (PHA). No significant effects of ascorbate or its salts on lymphocyte mitogen-induced transformation, intracellular protein synthesis, motility and numbers of active E rosettes were found. However, increased incorporation of radiolabelled amino acids into secreted protein and increased production of leucocyte inhibitory factor (LIF) were observed at calcium and sodium ascorbate concentrations of 10(-6)M--10(-4)M.

Ascorbic Acid↗

Effects of ascorbate on leucocytes: Part III. In vitro and in vivo stimulation of abnormal neutrophil motility by ascorbate.

Abnormal in vitro neutrophil motility was found in 10 patients with recurrent bacterial infection. The defect appeared to be primary in 3 patients, secondary to hyperimmunoglobulinaemia E in 2 patients and secondary to bacterial infection in 5 patients. In 7 patients impaired polymorphonuclear leucocyte (PMN) motility was the only detectable abnormality; defective lymphocyte function was found in 2 patients and 1 had a total IgA deficiency. Increased random motility and migration to endotoxin-activated serum (EAS) and partially purified C5a was observed when patients' neutrophils were incubated with 5 x 10(-2)M calcium ascorbate or 10(-1)M sodium ascorbate in the presence of 5% autologous serum in vitro. Six of the patients, 4 children and 2 adults, were given oral ascorbate, 1 g daily for children and 3 g daily for adults, and tests of neutrophil migration were performed at monthly intervals thereafter. Improved neutrophil motility was observed in all patients and this correlated with clinical improvement in 5 of the 6.

Adult↗

Effects of ascorbate on leucocytes: Part I. Effects of ascorbate on neutrophil motility and intracellular cyclic nucleotide levels in vitro.

A preliminary series of experiments indicated that ascorbic acid and calcium and sodium ascorbate in the absence of serum had no stimulatory effect on neutrophil motility. However, when neutrophils were pre-incubated with ascorbate at concentrations between 5 X 10(-2)M and 1 X 10(-1)M in the presence of fresh normal autologous serum (5% final concentration) considerable stimulation of random motility and migration towards the leuco-attractants C5a and casein was observed. The serum factor required for ascorbate-mediated enhanced locomotion was heat unstable and was probably not serum albumin since no stimulation of cell migration was observed when serum was replaced with varying amounts of human serum albumin. Calcium ascorbate was the most potent stimulant of neutrophil motility. Concentrations of calcium and sodium ascorbate which increased migration promoted elevation of intracellular cyclic guanosine monophosphate (cGMP) levels, but not of adenosine monophosphate (cAMP). These same concentrations also caused increased glyclytic activity. It is suggested that the enhanced neutrophil motility mediated by ascorbic acid and calcium and sodium ascorbate in the presence of serum may be due to increased cGMP and/or glycolysis.

Ascorbic Acid↗