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Biomedical subjects

A H Rose

Publications and source records attributed to A H Rose.

At least 19 recordsLinked to original sources

Cyclosporin immunosuppression of sheep: pharmacokinetics and allograft survival.

A chronically immunosuppressed sheep model was established using a regimen of cyclosporin A (CsA; 2-3mg/kg twice daily) and ketoconazole (10mg/kg twice daily). Blood CsA concentrations reached a steady-state after 17 days of treatment. The clearance of CsA decreased from a mean (95% CI) of 9.47 (6.2-12.7)ml/min/kg after a single (first) dose (3mg/kg i.v.) to 1.62 (1.38-1.86)ml/min/kg after 18 days of CsA (3mg/kg i.v. twice daily) co-administration with ketoconazole. These data indicated that the combination of CsA and ketoconazole could be used to give stable high concentrations of CsA in the sheep. Using this regimen in the sheep, the long-term survival of skin allografts was monitored as an indicator of effective immunosuppression. CsA in blood was measured daily and CsA dose adjusted to various target concentration ranges. Provided that the trough concentration of blood CsA was maintained between 1500-2500 mg/l, long-term healthy skin allografts were maintained on the sheep without significant adverse effects on haematological or biochemical parameters.

Animals↗

Validation of a new scoring system for the assessment of clinical trial research of oral mucositis induced by radiation or chemotherapy. Mucositis Study Group.

BACKGROUND: An impediment to mucositis research has been the lack of an accepted, validated scoring system. The objective of this study was to design, test, and validate a new scoring system for mucositis that can be used easily, is reproducible, and provides an accurate system for research applications. METHODS: A panel of experts, convened to design an objective, simple, and reproducible assessment tool to evaluate mucositis with specific application to multicenter clinical trials, developed a scale that measured objective and subjective indicators of mucositis. Nine centers participated in the study's validation. Paired investigators at each center evaluated patients receiving chemotherapy or head and neck radiation. Objective measures of mucositis evaluated ulceration/pseudomembrane formation and erythema. Subjective outcomes of mouth pain, ability to swallow, and function were measured. Analgesia use for mouth sensitivity was recorded. RESULTS: One hundred eight chemotherapy and 56 radiation therapy patients were evaluated. Seventy-eight percent of chemotherapy patients and 64% of radiation therapy patients had clinically significant mucositis. Cumulative daily mucositis scores demonstrated a high correlation among observers. Using area under the curve analysis, it was found that for chemotherapy patients, the highest correlations (correlation coefficient > 0.92) occurred for the scores that selected the three highest daily values over the course of mucositis assessment. High interobserver correlations were noted for patients receiving radiation therapy. Objective mucositis scores demonstrated strong correlation with symptoms. CONCLUSIONS: The scoring system evaluated was easily used, showed high interobserver reproducibility, was responsive over time, and measured those elements deemed to be associated with mucositis. The use of concomitant symptomatic measurements appeared to be unnecessary.

Adult↗

Orthotopic xenografts of human melanoma and colonic and ovarian carcinoma in sheep to evaluate radioimmunotherapy.

Extrapolation to humans from experimental radioimmunotherapy in nude mouse xenograft models is confounded by large relative tumour size and small volume of distribution in mice allowing tumour uptake of radiolabelled antibodies unattainable in patients. Our large animal model of human tumours in cyclosporin-immunosuppressed sheep demonstrated tumour uptake of targeted radiolabelled monoclonal antibodies comparable with uptakes reported in clinical trials. Sheep immunosuppression with daily intravenous cyclosporin augmented by oral ketoconazole maintained trough blood levels of cyclosporin within the range 1000-1500 ng ml(-1). Human tumour cells were transplanted orthotopically by inoculation of 10(7) cells: SKMEL melanoma subcutaneously; LS174T and HT29 colon carcinoma into bowel, peritoneum and liver; and JAM ovarian carcinoma into ovary and peritoneum. Tumour xenografts grew at all sites within 3 weeks of inoculation, preserving characteristic morphology without evidence of necrosis or host rejection. Lymphatic metastasis was demonstrated in regional nodes draining xenografts of melanoma and ovarian carcinoma. Colonic LS1 74T xenografts produced mucin and carcinoembryonic antigen (CEA). The anti-CEA IgG1 monoclonal antibody A5B7 was radiolabelled with iodine-131 and administered intravenously to sheep. Peak uptake at 5 days in orthotopic human tumour transplants in gut was 0.027% DI g(-1) (percentage of injected dose per gram) and 0.034% DI g(-1) in hepatic metastases with tumour to blood ratios of 2-2.5. Non-specific tumour uptake in melanoma was 0.003% DI g(-1). Uptake of radiolabelled monoclonal antibody in human tumours in our large animal model is comparable with that observed in patients and may be more realistic than nude mice xenografts for prediction of clinical efficacy of radioimmunotherapy.

Adenocarcinoma↗

Clonal analysis of lung and blood T cells in patients with sarcoidosis.

BACKGROUND: Sarcoidosis is a disease characterised by clinical "anergy" to delayed type hypersensitivity antigens and the formation of non-caseating granulomas, which frequently manifests in the lungs as a T lymphocyte/mononuclear cell alveolitis. Although there is an increased proportion of T cells in bronchoalveolar lavage (BAL) samples from these patients, and these T cells often show evidence of activation and spontaneous secretion of cytokines such as interleukin 2 (IL-2) and interferon gamma (IFN gamma)--a pattern similar to delayed type hypersensitivity reactions--it is unclear whether both cytokines are produced by the majority of T cells derived from the lungs of patients with sarcoidosis or whether unique subpopulations of T cells produce each cytokine. In this study the properties of T cells cloned from BAL fluid samples of patients with sarcoidosis have been analysed. METHODS: T cells were cloned by limiting dilution using IL-2, phytohaemagglutinin, and irradiated feeder cells. Cloning efficiencies were compared and phytohaemagglutinin induced clonal production of IL-2, IFN gamma, and IL-4 was determined by bioassay (IL-2 and IFN gamma) or ELISA (IL-4). RESULTS: T cells derived from the BAL fluid of patients with sarcoidosis cloned less efficiently than those from blood of the same individuals. Lung derived clones (CD4+ or CD8+) produced IFN gamma more frequently and to a higher titre than blood derived clones, whereas IL-2 production by CD4+ clones derived from BAL fluid was less than that from blood derived clones. Interestingly, IL-4 production by clones from both sites was similar. Analysis of the co-production of IL-2, IFN gamma, and IL-4 by these BAL fluid clones did not demonstrate a predominant "Th1"-like population which has been suggested to underlie delayed type hypersensitivity reactions. CONCLUSIONS: The reduced cloning efficiency of T cells from the lung compared with the blood in sarcoidosis is consistent with, although probably more pronounced than, previous observations in normal lungs and shows that T cell hyporesponsiveness is not overcome in the lungs of patients with sarcoidosis. Furthermore, major differences exist between the cytokine producing potential of T cells derived from the lung and the blood in sarcoidosis, and these parallel the differences in the properties of blood and lung T cells seen in healthy individuals.

Adult↗

An analysis of the relationship between gamma delta T cell receptor V gene usage and non-major histocompatibility complex-restricted cytotoxicity.

gamma delta T cells are capable of mediating non-major histocompatibility complex (MHC) restricted lysis of a variety of tumour cell lines. The mechanism of this lysis and its significance in tumour immunity are not clear. We have used a panel of five malignant mesothelioma (MM) cell lines, as well as standard tumour targets K562 and Daudi, to investigate some of the factors which could be involved in non-MHC restricted cytotoxicity mediated by gamma delta T cells. Individual MM cell lines, representing a panel of lines derived from a single cell type, varied in their susceptibility to lysis by gamma delta T cell clones. Individual gamma delta T cell clones also showed unique cytotoxic profiles, and differed in their cytotoxic potential. T cell receptor (TCR) V gamma gene usage correlated with the ability of clones to lyse Daudi or K562; clones lysing Daudi expressing V gamma 9 and clones lysing K562 expressing V gamma I subgroup genes. No strict correlation between V gamma and V delta gene usage and MM reactivity was, however, demonstrable. There was also no correlation between gamma delta T cell lysis of MM cell lines and the capacity of gamma delta T cells to produce interferon-gamma, tumour necrosis factor-alpha, interleukin-2 or interleukin-4, nor with their expression of CD8.

Clone Cells↗

Genetic 'risk' for atopy is associated with delayed postnatal maturation of T-cell competence.

Recent in vitro studies suggest that IgE production in adults is co-ordinately regulated by negative signals from gamma IFN-producing CD4+ T-helper-1 (TH-1) and positive signals from IL-4 producing (TH-2) T-cells. Additionally, seroepidemiological evidence has pinpointed infancy as the period of maximum lifetime risk for T-cell sensitization to ubiquitous environmental antigens. The present study sought to elucidate the relationship between these observations, by examination of CD4+ T-cell function in normal children and those genetically at 'high risk' for atopy, spanning the age range (up to 4 years) in which IgE responses to environmental allergens is typically manifest. Immunocompetent T-cell precursor frequencies (determined by cloning at limiting dilution) were markedly reduced in 'high risk' children relative to normals (0.53 +/- 0.29 vs 0.26 +/- 0.19; P = 0.0025). Consistent with reports from other laboratories employing bulk T-cell culture techniques, the gamma IFN producing capacity of CD4+ T-cell clones from both groups of children were markedly reduced relative to adults, and was lowest in the high risk group (P < 0.02). IL-4 production by CD4+ T-cell clones from the normal children was within the adult range, but again was significantly lower in the high risk group (P < 0.00005). This indicates that initial immune responses to environmental allergens in early childhood occur against a background of maturational 'deficiency' in CD4+ T-cell function, and suggests the possibility that variations in the rate of postnatal maturation of T-cell competence may be a contributing factor in the development of differing patterns of immunological responsiveness to environmental allergens.

Adult↗

A clonal analysis of lung T cells derived by bronchoalveolar lavage of healthy individuals.

The characteristics of the T-cell population in the healthy human lung have been investigated by analysing the properties of T-cell clones derived from bronchoalveolar lavage (BAL) samples and comparing them with T cells cloned from the blood of the same individuals. The proportions of CD4+ and CD8+ T cells in the starting populations from BAL and blood were similar although only 14% of BAL T cells were CD45RA+ compared to 70% of blood T cells. The precursor frequency of T-cell clones derived from BAL was less than from blood. The cytokine profiles [after phytohaemagglutinin (PHA) stimulation] of the clones derived from both sources were markedly different and these differences lay in the CD4+ population. BAL-derived CD4+ clones produced interferon-gamma (IFN-gamma) more frequently than did those from blood while blood-derived clones were more likely to produce interleukin-2 (IL-2) than those from BAL. IL-4 was produced by the majority of BAL- or blood-derived clones (93% and 88% respectively) either along with IFN-gamma (BAL) or IL-2 (blood). The cytokine profiles of BAL-derived T-cell clones are consistent with those derived from lung interstitium and suggest that the BAL T-cell populations reflect those in the lung wall. Whether the unique properties of lung T cells are acquired after leaving the blood or whether there is selective entry of T-cell subpopulations into the lung remains to be determined.

Adult↗

Incorporation of unsaturated fatty acids by Saccharomyces cerevisiae: conservation of fatty-acyl saturation in phosphatidylinositol.

Saccharomyces cerevisiae was grown anaerobically in media supplemented with myristoleic 14:1(9c), palmitoleic 16:1(9c), oleic 18:1(9c), linoleic 18:2(9,12c), gamma-linolenic 18:3(9,12,15c) or eicosenoic 20:1(11c) acid. Cells from exponential-phase cultures contained approximately the same proportions of the major phospholipid classes, namely phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine, the greatest differences being detected in cells grown in the presence of 14:1(9c) or 20:1(11c) acids. The extent to which phospholipids from cells were enriched with residues of the exogenously supplied acid varied from 52% in cells grown in the presence of 14:1(9c) acid to 13% in cells grown in media supplemented with 20:1(11c) acid. Analysis of the fatty-acyl composition of the four major phospholipid classes revealed that the degree of unsaturation varied considerably in three of the classes, while phosphatidylinositol conserved a high degree of saturation. The possible significance of the latter finding in relation to the physiological role of phosphatidylinositol in the plasma membrane is discussed.

Anaerobiosis↗

Pulmonary gamma interferon production in patients with fibrosing alveolitis.

Patients with fibrosing alveolitis have active inflammation within their lung interstitium. Previous studies have focused on the humoral (immune complex) driven processes. In this study increased pulmonary gamma interferon production has been evaluated. Bronchoalveolar lavage cells were obtained from 40 patients with fibrosing alveolitis, 22 with cryptogenic fibrosing alveolitis, and 18 with connective tissue disease associated (CTD) fibrosing alveolitis. Increased gamma interferon production was seen in 12 (30%) patients and was similar in the two study groups. Up to 512 units/10(6) cells were released over 24 hours, showing that the amounts of gamma interferon released could be as large as those seen in other pulmonary diseases associated with active cellular immune processes, such as sarcoidosis. Spontaneous gamma interferon production was related to increased serum concentrations of IgG and IgM but not to serum IgA, antinuclear antibody, or rheumatoid factor titres. There was no relation between gamma interferon production and pulmonary uptake of gallium-67 citrate. The ratio of helper-inducer (Leu-3) to suppressor-cytotoxic (Leu-2) cells in bronchoalveolar lavage fluid was similar in the two study groups and was similar in patients whose cells produced gamma interferon and those whose cells did not. These data suggest that gamma interferon is released in the lungs of a proportion of individuals with cryptogenic fibrosing alveolitis and CTD-fibrosing alveolitis, suggesting a role for this cytokine in mediating these diseases.

Bronchoalveolar Lavage Fluid↗

Accumulation of sulphite by Saccharomyces cerevisiae and Zygosaccharomyces bailii as affected by phospholipid fatty-acyl unsaturation and chain length.

Analyses were made of the fatty-acyl composition of phospholipids from each of two strains of Saccharomyces cerevisiae and Zygosaccharomyces bailii grown aerobically. Residues of C16:0, C16:1 and C18:1 predominated in phospholipids from strains of the first yeast, while phospholipids from Z. bailii contained mainly C16:0, C18:1 and C18:2 residues. S. cerevisiae NCYC 431, grown anaerobically in media supplemented with ergosterol and C14:1, C16:1, C18:1, C18:2, C18:3 or C20:1 fatty acids, contained phospholipids enriched with residues of the exogenously provided acid, to a greater extent with shorter chain than longer chain acids. A plot of the permeability coefficient for sulphite, derived from Woolf-Eadie plots, against the degree of unsaturation in phospholipids (expressed as delta mol-1 value) showed that the coefficient was greater the lower the degree of unsaturation in the phospholipids. A plot of the permeability coefficient against values for the mean fatty-acyl chain length divided by the delta mol-1 value, which is an approximation of the cross-section surface area of a phospholipid molecule, showed that the permeability coefficient tended to increase the greater the surface-area value.

Cell Membrane Permeability↗

Gallium lung scanning and bronchoalveolar lavage in crocidolite-exposed workers.

Gallium lung scanning is widely used to evaluate pulmonary inflammation in patients with interstitial lung disease but has not previously been reported in crocidolite-exposed workers. In order to characterize the pulmonary inflammation caused by crocidolite inhalation, GLS and BAL findings were related to chest x-ray film changes graded according to the ILO classification of roentgenograms of pneumoconioses. In individuals with roentgenographic evidence of asbestosis (CXR greater than or equal to 1/0, n = 15), 13 had a positive GLS and 13 had an abnormal BAL. In asbestos-exposed individuals with equivocal chest x-ray film changes (CXR 0/1, n = 12), six had a positive GLS and six had BAL changes (both GLS and BAL abnormal in three). In individuals with a normal chest x-ray film (CXR 0/0 n = 8), two had a positive GLS and two BAL changes (both abnormal in 1). These data demonstrate that most subjects with crocidolite-induced asbestosis have an abnormal GLS and BAL. In addition, many individuals with asbestos exposure and equivocal or no chest x-ray film changes have an abnormal GLS and/or BAL, suggesting the presence of active subclinical pulmonary inflammation in these individuals.

Asbestos↗

Sterol uptake by anaerobically grown Saccharomyces cerevisiae.

Wild-type Saccharomyces cerevisiae Y185 grown anaerobically was used to investigate the uptake and subsequent utilisation of sterol in S. cerevisiae. Results confirmed a minimum free sterol concentration below which growth was retarded. The yeast does, however, appear capable of taking up sterol well in excess of that required for growth. Evidence is presented indicating the ability of the yeast cell wall to bind cholesterol both in vivo and with isolated cell walls. There appears to be a role for low density vesicles in the movement of sterol once within the cell.

Aerobiosis↗

Long-chain alcohol production by yeasts.

Fourteen yeast strains from six genera were analysed for the presence of long-chain alcohols, the highest levels being found in Candida albicans. The major alcohols synthesized were saturated, primary alcohols with C14, C16 or C18 chain length with relative proportions of C16 greater than C18 greater than C14. In C. albicans synthesis of long-chain alcohols occurred only after the end of exponential growth. Long-chain alcohol contents were lower in organisms grown aerobically as compared with anaerobically and contents of all three classes increased as the concentration of glucose was raised from 1.0 to 30.0% (w/v). In anaerobic cultures greatest alcohol contents were obtained using medium containing 10% (w/v) glucose. Substituting glucose (10%, w/v) with the same concentration of galactose in aerobic cultures greatly decreased contents of long-chain alcohols, while inclusion of 10% (w/v) glycerol virtually abolished their synthesis. Supplementing anaerobic cultures with odd-chain fatty acids induced synthesis of odd-chain alcohols, Nitrogen limitation induced long-chain alcohol synthesis in aerobically grown Candida maltosa and quantities were increased with conditions of glucose excess and nitrogen limitation.

Aerobiosis↗

Bronchoalveolar lavage sampling of airway and alveolar cells.

Bronchoalveolar lavage (BAL) cell counts are used to assess 'alveolitis' in patients with interstitial lung diseases (ILD) but inflammatory cells from airways can contribute to the differential cell count. To determine what BAL volume samples airway cells in patients with ILD we measured the proportion of bronchial epithelial cells (BECs) in four successive 25 ml aliquots in a single lung subsegment in 23 patients with ILD (cryptogenic fibrosing alveolitis (CFA) four, rheumatoid lung (RL) three, asbestosis (ASB) 11, sarcoidosis (SARC) five). Cells recovered from the first two 25 ml lavages exhibited higher proportions of BECs (15 +/- 4% and 9 +/- 2% respectively) than those from the remaining two aliquots (3 +/- 1%, 3 +/- 1%, each P less than 0.01), suggesting that the first 50 ml BAL preferentially samples airway cells compared to the second 50 ml BAL. To evaluate airway and alveolar inflammatory cell proportions in ILD we performed two separate 50 ml BALs (samples I and II) in a single subsegment in 38 patients with ILD (CFA seven, RL five, ASB 19, SARC seven) and measured the proportions of recovered cells in each sample separately and combined. Seven control individuals were also studied. Sample I contained 1-67% (mean 26 +/- 3%) of the total recovered cells. Neutrophil (PMN) proportions were higher in sample I compared to sample II in CFA (20 +/- 6 vs 8 +/- 2%), RL (30 +/- 9 vs 8 +/- 2%) and ASB (12 +/- 2 vs 7 +/- 1%), P less than 0.05 for each, but were similar in samples I and II in patients with SARC (3 +/- 1 vs 2 +/- 1%) and controls (2 +/- 1 vs 2 +/- 1%). In combined samples (I + II), absolute PMN proportions were up to 8% higher than in sample II alone whereas absolute lymphocyte proportions were up to 8% less than in sample II alone. These data suggest that separate processing of the fluid recovered from the first 50 ml BAL in ILD patients provides information on the location of inflammatory cells and improves the accuracy of BAL cell counts.

Adult↗

Reactions of Saccharomyces cerevisiae and Zygosaccharomyces bailii to sulphite.

Sulphite inhibited growth of all four yeasts studied, Zygosaccharomyces bailii NCYC 563 being most sensitive and Saccharomyces cerevisiae NCYC 431 the least. Vertical Woolf-Eadie plots were obtained for initial velocities of 35S accumulation by all four yeasts suspended in high concentrations of sulphite. Equilibrium levels of 35S accumulation were reached somewhat faster with strains of S. cerevisiae than with those of Z. bailii. With all four yeasts, the greater the extent of 35S accumulation, the larger was the decline in internal pH value. Growth of S. cerevisiae TC8 and Z. bailii NCYC 563, but to a lesser extent of S. cerevisiae NCYC 431 and Z. bailii NCYC 1427, was inhibited when mid exponential-phase cultures were supplemented with 1.0 or 2.0 mM-sulphite, the decrease in growth being accompanied by a decline in ethanol production. Unless growth was completely inhibited, the sulphite-induced decline in growth was accompanied by production of acetaldehyde and additional glycerol.

Acetaldehyde↗

Effect of glucose and long-chain fatty acids on synthesis of long-chain alcohols by Candida albicans.

Candida albicans, grown aerobically in glucose-containing media, produced C14, C16 and C18 saturated long-chain alcohols only after the end of exponential growth. Contents of C14 alcohols were always lowest, and C16 and C18 alcohol contents about equal. Contents of all three classes of alcohol increased as the concentration of glucose in aerobic cultures harvested after 168 h incubation was raised from 1.0 to 30.0% (w/v). However, in 168 h anaerobic cultures, greatest long-chain alcohol contents in organisms were obtained using media containing 10% (w/v) glucose. Substituting glucose (10%, w/v) with the same concentration of galactose in aerobic cultures greatly decreased contents of long-chain alcohols, while inclusion of 10% (w/v) glycerol virtually abolished their synthesis. Supplementing anaerobic cultures with odd-chain fatty acids induced synthesis of odd-chain alcohols. Maximum conversion of fatty acid to the corresponding long-chain alcohol was observed with heptadecanoic acid. The effect of glucose on production of heptadecanol from exogenously provided heptadecanoic acid was similar to that observed on synthesis of the three major even-chain alcohols in media lacking a fatty-acid supplement. Cell-free extracts of organisms catalysed in vitro conversion of palmitoyl-CoA to 1-hexadecanol.

Alcohols↗