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Biomedical subjects

R Anderson

Publications and source records attributed to R Anderson.

At least 631 records · Page 35Linked to original sources
PubMed1981

A test of the Broen-Storms theory of cognitive deficit in schizophrenia.

Broen and Storms have developed a popular behavioristic theory to explain schizophrenic thought disorder. It holds that thought disorder results from schizophrenics' having higher drive levels and lower response-strength ceilings than non-schizophrenics. As a result, the strength of appropriate (usually strong) responses is rivaled by that of inappropriate, ordinarily-weak responses. This, in Broen and Storms' theory, is the cause of disorganized, schizophrenic behavior. We tested several hypotheses derived from Broen and Storms' assumptions that schizophrenics have higher drive and lower response strength ceilings than controls in a paired-associates learning study. We did not find support for our hypotheses that schizophrenics would show better early-trials learning than controls, that a presumably drive-inducing threat of pain would enhance early trials learning in schizophrenics or controls, that either threat of pain or schizophrenia would be associated with a low learning asymptote, or that either the positive or negative effects of pain would be accentuated in schizophrenics. The results did not support the theory.

Attention↗
PubMed1981

Prevention of peroxidase mediated inhibition of neutrophil motility and lymphocyte transformation by levamisole, OMPI, sodium aurothiomalate, indomethacin and tolmetin in vitro.

The effects of sodium aurothiomalate, levamisole, its active metabolite OMPI and the anti-inflammatory agents indomethacin and tolmetin on neutrophil motility and post-phagocytic hexose monophosphate shunt activity, superoxide and H2O2 generation and myeloperoxidase (MPO) mediated iodination of Candida albicans were investigated in vitro. All five agents caused stimulation of neutrophil random motility and migration towards the leucoattractants f-met-met-phe and EAS. Only levamisole caused inhibition of H2O2 and superoxide production, which was associated with inhibition of HMS activity and not related to superoxide scavenging activity. All five agents caused inhibition of MPO mediated iodination of C. albicans. The relationship between inhibition of peroxidase mediated iodination and enhanced motility was further investigated using the horseradish peroxidase (HRP) H2O2/iodide system. Incubation of neutrophils with this system caused inhibition of neutrophil motility. However in the presence of the various drugs neutrophils were protected from inhibition of motility by the HRP/H2O2/iodide system. Further experiments showed that lymphocyte transformation to mitogens was also inhibited by the HRP/H2O2/iodide system. Incubation of lymphocytes with the various drugs prior to exposure to HRP/H2O2/iodide protected the lymphocyte mitogenic responsiveness.

Anti-Inflammatory Agents↗
PubMed1981

A simple and reproducible experimental in vivo glioma model.

A simple and reproducible injection technique has been developed for inducing an in vivo experimental astrocytoma model in rats. Newborn rats were injected with a suspension of astrocytoma C-6 cells in doses ranging from 5 to 1 X 10 5 cells. The optimum dose of tumor cells was found to be between 10 4 and 10 5 cells, with a consistent 100% take rate seen above 1 X 10 4 injected cells. The injection of less than 10 4 cells resulted in a decreased ability to induce tumors, and a prolonged survival. The pathology was consistent with that of a glioblastoma multiforme. The tumor showed a diffuse infiltrating border, necrosis, and pseudopalisading. Light microscopy revealed undifferentiated tumor cells while electron microscopy demonstrated rough endoplasmic reticulum, Golgi complexes, mitochondria, and the occasional cilium and centriole. The nature of the astrocytoma C-6 cell line, and the advantages, disadvantages and possible uses of the model and discussed.

Animals↗
PubMed1981

Multifocal recurrent periostitis. Report of two cases.

Two case reports of recurrent multifocal periostitis in two girls aged 15 and 6 are added to the eight cases already reported in the literature. The disease is characterized clinically by recurrent mesomelic swelling of the extremities and radiologically by periosteal thickening and sclerosis of underlying bone. Hyperglobulinaemia is the most constant biochemical finding. The bone biopsy shows no typical features. The possibility of a viral etiology is discussed.

Adolescent↗
PubMed1981

Ascorbate-mediated stimulation of neutrophil motility and lymphocyte transformation by inhibition of the peroxidase/H2O2/halide system in vitro and in vivo.

Neutrophil migration, postphagocytic hexose-monophosphate shunt activity and myeloperoxidase-mediated iodination of ingested Candida albicans and lymphocyte mitogen-induced transformation were assessed in six normal volunteers before and 1 h after a single intravenous injection of 1 g ascorbate. Increased neutrophil motility was observed which was associated with decreased myeloperoxidase-mediated iodination of C. albicans and a slight increase in hexose-monophosphate shunt activity. Lymphocyte transformation was also increased. Alterations in these activities were related to serum ascorbate levels. To investigate the relationship of ascorbate-mediated increased neutrophil motility and lymphocyte transformation to decreased peroxidase activity neutrophils and lymphocytes from normal individuals were exposed to the horseradish peroxidase/H2O2/sodium iodide system in the presence and absence of ascorbate and tested for migratory and proliferative responses respectively. Exposure to the horseradish peroxidase/H2O2/halide system caused inhibition of neutrophil motility and lymphocyte responsiveness to mitogens. However, inclusion of ascorbate protected both the neutrophils and lymphocytes from the inhibitory effects of the horseradish peroxidase/H2O2/halide system.

Ascorbic Acid↗
PubMed1981

Cellular synthesis and modification of murine hepatitis virus polypeptides.

Mouse L fibroblasts infected with mouse hepatitis virus, MHV3, and radiolabelled with 35S-methionine, contained, in addition to the three major structural polypeptides, p24, p56 and p180, two additional ones, p22 and p50. Of these total five polypeptides, only three, p22, p56 and p180, were labelled in infected cells during a 2 min 35S-methionine pulse and are, therefore, presumed to be immediate translation products. Pulse-chases and chymotryptic peptide mapping experiments showed apparent precursor-product relationships between p56 and p50 and between p22 and p24. Protein synthesis in infected cells was synchronized at the initiation stage by pre-exposure to hypertonic medium. Using a 0.5 min pulse-10 min chase sequence, to limit incorporation of 35S-methionine to stretches of approx. 100 amino acids adjacent to translational initiation sites, it was found that all three polypeptides, p22, and p56 and p180 contained radiolabel. It is thus apparent that translation of the three major structural proteins (or precursors) is initiated independently rather than at a single site as in the cases of other positive-strand RNA viruses such as polio or Semliki Forest virus.

Animals↗
PubMed1981

In vitro and in vivo effects of dapsone on neutrophil and lymphocyte functions in normal individuals and patients with lepromatous leprosy.

The effects of dapsone on polymorphonuclear leukocyte functions and lymphocyte mitogen-induced transformation were assessed in vitro and in vivo in normal individuals and in newly diagnosed untreated patients with lepromatous leprosy. The effects of dapsone on the cell-free generation of superoxide by the xanthine: xanthine oxidase system and iodination of bovine serum albumin by horseradish peroxidase were also investigated. In normal individuals dapsone mediated stimulation of polymorphonuclear leukocyte migration in vitro and vivo. Dapsone had no effect on postphagocytic hexose monophosphate shunt activity in vivo. Similar effects were found in patients with lepromatous leprosy. Dapsone also decreased the inhibitory activity of serum from patients with lepromatous leprosy on normal polymorphonuclear leukocyte migration in vitro. Progressive loss of serum-mediated inhibition of migration was observed after ingestion of dapsone by the patients. Further experiments showed that stimulation of polymorphonuclear leukocyte motility was related to inhibition of lymphocyte transformation at high concentrations in vitro, but had slight stimulatory activity on phytohemagglutinin-induced transformation in controls and patients in vivo.

Cell Movement↗
PubMed1981

Tetraploidy in a liveborn infant with spina bifida and other anomalies.

Although tetraploidy of human chromosomes (92,XXYY) has been described frequently in abortuses, only one example in a liveborn infant has previously been described. A second malformed infant with a complete tetraploid chromosome complement, who lived for 15 days, is reported. In addition to many of the malformations described in the first case, this infant also had a sacral myelomeningocele and skeletal anomalies. The probable origin of the tetraploidy was a failure of cytoplasmic cleavage at the first mitotic division of the fertilised ovum.

Abnormalities, Multiple↗
PubMed1981

Levamisole stimulation of neutrophil chemotaxis and chemokinesis by protection of both the leucoattractant and the cellular chemotactic response from inactivation by the peroxidase/hydrogen peroxide/halide system in vitro.

The effects of levamisole, at concentrations known to stimulate neutrophil motility, on neutrophil post-phagocytic metabolic activity were investigated. Levamisole at these concentrations caused inhibition of hexose monophosphate shunt (HMS) activity, superoxide production, hydrogen peroxide generation and myeloperoxidase (MPO), mediated iodination of ingested Candida albicans,. The inhibition of MPO-mediated iodination was not solely due to lack of H2O availability as a result of decreased HMS activity but also to a primary inhibition of iodination as shown in a cell-free system with horse-radish peroxidase (HRP) and added H2O2 and sodium iodide. Further experiments were designed to investigate possible relationships between stimulation and motility and levamisole-induced inhibition of superoxide generation and peroxidase-mediated iodination. These showed that the peroxidase/halide/H2O2 system caused inactivation of both the leucoattractant and neutrophil chemotactic responsiveness. However, concentrations of levamisole, which stimulate motility and inhibit superoxide production and peroxidase-mediated iodination, protected both the leucoattractant response and the ability of the cell to respond to the leucoattractant from inactivation by the HRP/H2O2/iodide system.

Chemotaxis, Leukocyte↗
PubMed1981

Computerized axial tomography with air contrast of the cerebellopontine angle and internal auditory canal.

The introduction of computerized axial tomography (C.T.) in 1973 completely changed the diagnostic evaluation of acoustic neuromas. Seventy to eighty percent of all acoustic neuromas can be diagnosed with intravenous enhanced C.T. scan. Acoustic tumors with a diameter of less than 1.5 cm, however, are not consistently seen on C.T. scan. Twenty-six consecutive patients were evaluated by C.T. scan with air contrast posterior fossa myelography (C.T. air cisternography). Nineteen studies were normal, with complete air filling of the internal auditory canal. Surgically verified acoustic neuromas were demonstrated in four patients. Two studies were inconclusive and there was one false positive. Other than headaches, there is no morbidity associated with this technique. C.T. air cisternography should be considered as the definitive study for evaluating patients for acoustic neuromas who have normal intravenous contrast enhanced C.T. scans. This study reports the first intracanalicular tumor diagnosed with this technique.

Adult↗
PubMed1981

Assessment of oral ascorbate in three children with chronic granulomatous disease and defective neutrophil motility over a 2-year period.

Two brothers and their sister with chronic granulomatous disease, elevated levels of serum IgE and defective neutrophil motility were treated with a single oral daily dose of 1 g sodium ascorbate as a supplement to prophylactic trimethoprim--sulphamethoxazole therapy for 2 years. Laboratory tests of neutrophil functions were performed prior to ascorbate therapy and repeated at 1-monthly intervals for 6 months and at 6-monthly intervals thereafter. Introduction of ascorbate to the therapeutic regimen was accompanied by slight increases in neutrophil hexose monophosphate shunt activity and staphylocidal activity and good improvement of neutrophil motility in all three children. The improved staphylocidal activity was not due to ascorbate-mediated inhibition of neutrophil or serum catalase activities or to detectable increases in superoxide and H2O2 production or activity of the MPO/H2O2/halide system. Both male children have remained free from obvious infection since ascorbate was added to their therapeutic regimen; their sister has experienced one urinary tract infection during a period when treatment with prophylactic co-trimoxazole and ascorbate was inadvertently stopped. All three children have gained weight.

Ascorbic Acid↗
PubMed1981

In vitro and in vivo stimulation of neutrophil migration and lymphocyte transformation by thiamine related to inhibition of the peroxidase/H2O2/halide system.

The effects of thiamine on neutrophil functions and mitogen-induced lymphocyte transformation were investigated in vitro and in vivo in adult volunteers following the injection of 50 mg thiamine intramuscularly. Thiamine caused stimulation of neutrophil motility in vitro and in vivo and increased lymphocyte transformation in vivo. Enhancement of these functions was related to inhibition of neutrophil post-phagocytic iodination of Candida albicans by the MPO/H2O2/halide system. The horseradish peroxidase/-H2O2/125 I-mediated iodination of bovine serum albumin was also inhibited by thiamine concentrations which caused increased neutrophil motility. It was found that preincubation of neutrophils and lymphocytes with the horseradish peroxidase/H2O2/halide system caused considerable inhibition of the migratory and proliferative responses respectively. Inclusion of thiamine at concentrations which were found to inhibit the peroxidase/-H2O2/halide system protected the neutrophil migratory and lymphocyte proliferative responses from inactivation by this system. It is suggested that thiamine may cause increased neutrophil migration and lymphocyte transformation by protecting these cells from toxic oxidative products generated by the peroxidase/H2O2/halide system.

Adult↗
PubMed1980

The effect of ascorbate on cellular humoral immunity in asthmatic children.

Ten White children with bronchial asthma and exercise-induced bronchoconstriction were assessed immunologically before and 1, 3 and 6 months after the commencement of standard therapy supplemented with ascorbate 1 g/d. The tests of cellular immune function were neutrophil chemotaxis, phagocytosis and resting and stimulated nitroblue tetrazolium reduction, and lymphocyte mitogen-induced transformation. Humoral functions measured were secretory IgA, serum immunoglobulins, alpha 1-antitrypsin, C3, C4 and total haemolytic complement, antistreptolysin O (ASO) and C-reactive protein. Radio-allergosorbent testing to the common allergens Cynodon dactylon (grass), Dermatophagoides pteronyssinus (mite), house dust and cat epithelium was performed on each child before and 3 and 6 months after treatment. Two children had depressed neutrophil motility, 4 had depressed lymphocyte transformation, and 7 had elevated levels of ASO. These functions normalized after 6 months of ascorbate-supplemented therapy. Serum total IgE levels but not specific IgE levels were likewise reduced after 6 months of therapy. Reduced levels of serum alpha 1-antitrypsin were observed in 2 children, and remained unchanged throughout the study.

Antibody Formation↗