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Biomedical subjects

N Rand

Publications and source records attributed to N Rand.

27 records · Page 2Linked to original sources
PubMed1985

In vitro immunization of human lymphocytes. I. Production of human monoclonal antibodies against bombesin and tetanus toxoid.

A procedure for in vitro sensitization of human lymphocytes against bombesin conjugated to tetanus toxoid (BTT) is described. Bombesin is a tetradecapeptide associated with small cell lung carcinoma. We found that antibody responses against bombesin as well as tetanus toxoid could be generated in vitro by culturing nylon-separated human splenic lymphocytes for 6 days with lipopolysaccharide, phytohemagglutinin-activated lymphocyte supernatants, human AB serum, and bombesin conjugated to tetanus toxoid. Cells sensitized by this procedure were fused to murine myeloma cells, NS-1. The specificities of resulting hybrids were analyzed by enzyme-linked immunoassays and competitive inhibition experiments. Hybrids secreting anti-bombesin (IgM) or anti-tetanus toxoid (IgM or IgG) were obtained. The ratio of IgG to IgM antibodies against tetanus toxoid could be increased by using antigen coupled to Sepharose beads. The sensitization procedure described here offers a system for the study of antigenic stimulation of human B lymphocytes in vitro and for the production of human monoclonal antibodies with the desired specificities.

Animals↗
PubMed1984

Retinoblastoma: tissue culture lines and monoclonal antibody studies.

Retinoblastoma patients have cellular and humoral reactivity towards antigens expressed on retinoblastoma cells. We report the ultrastructural, cytogenetic, and immunologic features of four new retinoblastoma derived tissue culture cell lines. Studies with hybridoma produced monoclonal antibodies demonstrate that these lines share antigens with a previously described long-term allogeneic retinoblastoma derived tissue culture cell line, as well as with antigens on fresh retinoblastoma.

Antibodies, Monoclonal↗
PubMed1983

Antiretinoblastoma monoclonal antibodies.

Mouse-mouse somatic hybridization techniques were used to produce monoclonal antibodies directed towards antigen expressed on retinoblastoma-derived tissue culture cell lines. Four monoclonal antibodies were produced with varying avidity which were reactive against allogeneic retinoblastoma-associated antigens. Sensitivity and specificity was demonstrated using ELISA and chromium release assays. Immunofluorescent antibody studies suggest that these monoclonal antibodies may be useful diagnostically.

Animals↗
PubMed1982

Repair and replication of DNA in hereditary (bilateral) retinoblastoma cells after X-irradiation.

Fibroblasts from patients with hereditary retinoblastoma reportedly exhibit increased sensitivity to killing by X-rays. Although some human syndromes with similar or greater hypersensitivity to DNA-damaging agents (e.g., X-rays, ultraviolet light, and chemical carcinogens), such as xeroderma pigmentosum, are deficient in DNA repair, most do not have such clearly demonstrable defects in repair. Retinoblastoma cells appear to be normal in repairing single-strand breaks and performing repair replication after X-irradiation and also in synthesizing poly(adenosine diphosphoribose). Semiconservative DNA replication in these cells, however, is slightly more resistant than normal after X-irradiation, suggesting that continued replication of damaged parental DNA could contribute to the pathogenesis of the disease. This effect is small, however, and may be a consequence rather than a cause of the fundamental enzymatic abnormality in retinoblastoma that causes the tumorigenesis.

DNA↗
PubMed1982

Binding of retinoblastoma and normal sera to retinoblastoma-derived cultured cells.

We have observed increased binding of retinoblastoma patients' sera to a retinoblastoma-derived cultured cell line (Y-79). This reactivity was mediated by the serum IgG fraction and was directed toward different tumor or target cell (Y-79, Molt, Raji, and fibroblasts) cultured in media containing fetal calf serum. Normal pooled serum IgG fractions did not demonstrate any similar binding. When target cells were cultured in media containing human serum instead of fetal calf serum, a considerable reduction in retinoblastoma sera binding activity was observed. Reactivity against target retinoblastoma cells could be reduced but not entirely eliminated by quantitative absorption with nonretinoblastoma (Molt) cells grown in media with fetal calf serum. Retinoblastoma and normal sera binding to autologous fibroblasts, nonautologous fibroblasts, and cultured melanoma cells was also minimal. These findings suggest that residual binding activity in the sera tested may be directed against retinoblastoma tumor antigens. The fetal calf serum component responsible for reactivity with certain retinoblastoma sera was shown by immunoprecipitation, competitive inhibition, and gel electrophoresis to be bovine serum albumin.

Adolescent↗
PubMed1981

Fc and C3b receptors on cultured retinoblastoma cells.

Fc and C3b receptors were identified on cultured retinoblastoma cells. Labeled receptor protein bound to affinity gels prepared with IgG, Aggregated IgG, and Fc but not to control gels prepared from Fab'2 or Sepharose-4B alone. Eluted Fc receptors was partially characterized by polyacrylamide gel electrophoresis. Molecular weight of the isolated receptor or its subunit was approximately 4.3 X 10(4) daltons. Cultured retinoblastoma cells were found to rosette with human indicator erythrocytes specific for C3b and Fc receptors. This study indicates that considerable reactivity between retinoblastoma patients' sera and cultured tumor cells may be mediated by these receptors as well as by reactivity toward retinoblastoma antigens.

Cells, Cultured↗
PubMedDate not supplied

Degenerative lumbar stenosis: diagnosis and management.

Degenerative lumbar stenosis is a common cause of disabling back and lower extremity pain among older persons. The process usually begins with degeneration of the intervertebral disks and facet joints, resulting in narrowing of the spinal canal and neural foramina. Associated factors may include a developmentally narrow spinal canal and degenerative spinal instability. Nonoperative management includes restriction of aggravating activities, physical therapy, and anti-inflammatory medications. If nonoperative treatment has failed, surgical treatment may be appropriate. Decompression should be performed so as to address all clinically relevant neural elements while maintaining spinal stability. If instability is present, autogenous intertransverse bone grafting is recommended. There may be an advantage to augmenting some of these procedures with internal fixation. Surgical success rates as high as 85% have been reported, but may be compromised by inadequate decompression, inadequate stabilization, or medical comorbidities. Short-term follow-up data indicate that operative management provides more effective relief than nonoperative treatment, but prospective studies comparing the effects of nonoperative and operative interventions on the long-term natural history of lumbar spinal stenosis are needed.

Aged↗