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Biomedical subjects

B Christensen

Publications and source records attributed to B Christensen.

At least 181 records · Page 10Linked to original sources
PubMed1984

Antibody producing human-human hybridomas. II. Derivation and characterization of an antibody specific for human leukemia cells.

Human-human hybridoma technology was used to immortalize human B lymphocytes from patients with acute myeloid leukemia (AML) to study the antigenic repertoire of the humoral immune response against the patients' own leukemia cells and against leukemic cells from other patients. Nine fusions were done with lymphocytes from seven AML patients, and all with the human RH-L4 B lymphoma line as malignant fusion partner. A total of 305 Ig-producing hybrids were obtained. 26 reacted with cell surface components on AML cells, but 21 were found not to be specific for leukemia cells, when screened for reactivity against a panel of normal and malignant cells of both human and murine origin. Five hybridomas secreted Ig with high specificity for human leukemia cells, but only one hybridoma culture, aml-18, was stable in respect to Ig-production and growth upon repeated clonings and expansion in liquid cultures. A method was developed to grow human hybridomas as ascites tumors in nude mice, but the ascites fluid did not contain increased amount of antibody. The reactivity of the aml-18 antibody (gamma, kappa) was analyzed against samples of mononuclear cells from peripheral blood of 63 patients with leukemia and with cytologically verified leukemia cells in the blood. 22 of 54 AML samples reacted with aml-18. The reactivity pattern was not correlated to any categories of the French-American-British (FAB) classification; two of four ALL were positive. Moreover, a pronounced intratumoral antigenic heterogeneity in regard to aml-18 reactivity was seen and indicates a high degree of diversity in the immunological phenotype within individual AML cell populations. The study demonstrates that some patients with AML generate an immune response against their autologous malignant cells, and that the antigenic determinant in the case of aml-18 is also expressed specifically on leukemic cells from other patients.

Antibodies, Monoclonal↗
PubMed1984

Induction of DNA repair synthesis in human urothelial cells by the N-hydroxy metabolites of carcinogenic arylamines.

Urinary N-hydroxy metabolites of carcinogenic arylamines were investigated for their abilities to induce unscheduled DNA synthesis (UDS) in human urothelial cell lines HCV 29, HU 1734, and HU 1752, and in a primary culture of human urothelial cells. N-Hydroxy-2-aminofluorene (CAS: 53-94-1; N-OH-AF), N-hydroxy-2-acetylaminofluorene (CAS: 53-95-2; N-OH-AAF), and the N-glucuronide of N-OH-AF induced UDS in HCV 29, HU 1734, and HU 1752. N-Hydroxy-4-aminobiphenyl (CAS: 6810-26-0; N-OH-ABP), N-hydroxy-4-acetylaminobiphenyl (CAS: 4463-22-3; N-OH-AABP), N-hydroxy-2-aminonaphthalene (CAS: 613-47-8; N-OH-AN), N-hydroxy-2-acetylaminonaphthalene (CAS: 2508-23-8; N-OH-AAN), and the N-glucuronide of N-OH-ABP induced UDS in HCV 29. However, the N-glucuronide of N-OH-AN did not. The O-glucuronide of N-OH-AAF induced UDS in HCV 29 only when beta-glucuronidase was present. Paraoxon inhibited the induction of UDS in HCV 29 by N-OH-AAF and N-acetoxy-2-acetylaminofluorene (CAS: 6098-44-8), but not by N-OH-AF. When examined in a primary culture of human urothelial cells, N-OH-AF, N-OH-AAF, N-OH-ABP, and N-OH-AABP were active, but N-OH-AN, N-OH-AAN, 2-aminonaphthalene (CAS: 91-59-8), 2-aminofluorene (CAS: 153-78-6;), and 4-aminobiphenyl (CAS: 92-67-1) were not. These results demonstrate that human urothelial cells are able to activate both acetylated and non-acetylated N-hydroxy metabolites of carcinogenic arylamines, and they suggest that O-glucuronidation may be a detoxification mechanism for N-arylacethydroxamic acids.

2-Naphthylamine↗
PubMed1983

Comparative studies of normal, 'spontaneously' transformed and malignant human urothelium cells in vitro.

In numerous in vitro studies of cell-mediated cytotoxicity directed against transitional cell carcinomas (TCC) urothelial cells of normal origin have served as control material. In the present work, which includes 13 human bladder cell lines of non-malignant or malignant origin, a comparison was made of morphology, chromosomal mode, growth fraction and tumorigenicity in nude mice. Signs of apparently spontaneous transformation were seen in two cell lines of non-malignant origin. The possibilities for cross-contamination as an explanation of these signs of 'spontaneous' transformation are discussed. During these studies radiation-dependent cytotoxicity of disposable microtissue culture plates was revealed as another important source of error.

Aged↗
PubMed1983

Selected nutrient intakes of free-living white children ages 6-19 years. The Lipid Research Clinics Program Prevalence Study.

We report energy intake and selected nutrient intakes-protein, fat (total, saturated, and polyunsaturated), carbohydrate (total, starch, and sucrose), and cholesterol-for 1251 white children ages 6-19 years. The data were obtained, by means of a 24-h dietary recall, from children who were randomly selected from the North American populations studied by the Lipid Research Clinics Program. Females (N = 584) consumed about 2000 kcal daily, an intake that remained relatively constant throughout the age groups studied. Males (N = 667) had an energy intake of 2000 kcal/day during childhood that increased to over 3000 kcal/day in adolescence. Energy sources for both sexes were approximately 15% protein, 38% total fat, 15% saturated fat, 6% polyunsaturated fat, 48% total carbohydrate, 19% starch, and 11% sucrose; cholesterol intake averaged about 145 mg/1000 kcal. For both sexes, fat intake increased with age. Compared to females, males ingested greater amounts of cholesterol and total and saturated fat.

Adolescent↗
PubMed1983

Angiogenesis-inducing ability of human bladder epithelium cell lines and "spontaneously" transformed murine fibroblasts.

Ten human bladder epithelium cell lines were tested for their ability to induce blood vessel formation after intradermal injection into irradiated ST/a mice. Cell lines that were shown to be tumorigenic in nude mice, were able to evoke angiogenesis of a higher intensity than nontumorigenic cell lines. No difference was observed between the angiogeneic ability of tumorigenic cells originating from tumors and from in vitro transformed urothelium of nontumor origin. Similarly the origin of nontumorigenic urothelial cell lines did not show any influence on their angiogeneic abilities, but nontumorigenic cell lines which had undergone "infinite growth transformation" exhibited a higher angiogeneic activity than nontumorigenic cell lines with a finite life. The angiogeneic reaction evoked by human bladder epithelium cell lines showed cell dose- and time-dependence; but it was unrelated to the growth potential of the cultured cells. Two "spontaneously" altered sarcoma-producing murine cell lines showed a higher angiogeneic activity than tumorigenic human bladder epithelial cells. The angiogeneic response to these two murine cell lines was unrelated to morphological signs of transformation and to differences in growth rate, serum requirement, saturation density, anchorage dependence, and isoimmunizing properties.

Animals↗
PubMed1983

Blind quantitative electron microscopy of cilia from patients with primary ciliary dyskinesia and from normal subjects.

Cilia from the nasal cavity of 27 patients with congenital ciliary dyskinesia (immotile cilia syndrome) and of 15 normal persons were examined by transmission electron microscopy. The patients had on average a significantly higher number of cilia with absent or markedly reduced numbers of outer or inner dynein arms, of cilia with various types of abnormal configuration of the microtubules, except for compound cilia, and of cilia with an abnormally large variation of the beating axis. Compound cilia were equally frequent in patients and controls. The main structural defect in 9 patients was absent or abnormality low number of outer dynein arms in 4 in conjunction with an abnormally large axis variation and in 1 with a markedly reduced number of inner dynein arms also in 1 with supernumerous axonemal microtubules also. In 9 patients the main defects were abnormal configuration of the axonemal microtubules and a large axis variation. Seven of these had eccentrically located central pairs of microtubules and radial spoke defects, 5 in conjunction with abnormally low numbers of inner dynein arms. In one patient there were various types of abnormal configuration of the axonemal microtubules together with absent inner dynein arms, in another cilia with supernumerous microtubules only were present. The only abnormal finding in 1 patient was an extreme variation in the ciliary axes. Completely normal ciliary ultrastructure was found in 8 patients.

Adolescent↗