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B Caplan

Publications and source records attributed to B Caplan.

35 records · Page 2Linked to original sources
PubMed1982

Interleukin-2 does not induce murine B cells to secrete Ig.

We previously defined two T cell-derived lymphokines, BDCF mu and BCDF gama, which induce B cell differentiation in the absence of IL 2. Although these studies indicated that IL 2 was not required to induce Ig secretion, the effect of IL 2 on B cell differentiation was not established. In the present studies we have assessed the ability of purified IL 2 to induce IgM or IgG secretion. Our results demonstrate that IL 2 does not induce IgM secretion by BCL1 tumor cells, nor does it enhance BCDF mu-induced IgM secretion by these cells. Similarly, IL 2 had no effect on LPS or BCDF gamma-induced IgG secretion by normal B cells. Thus, we conclude that IL 2 does not act directly on B cells to induce differentiation.

Animals↗
PubMed1982

Neuropsychology in rehabilitation: its role in evaluation and intervention.

Knowledge of the mechanisms underlying cerebral function, breakdown, and recovery can provide a rational basis for designing rehabilitation programs for brain-injured patients. Specialists in clinical neuropsychology, those who assess the cognitive and behavioral effects of brain damage, thus have useful diagnostic and therapeutic expertise to offer rehabilitation units. Concepts pertaining to functional recovery after brain damage, for example, reorganization, substitution, compensation, and amelioration, are discussed. Several reports are reviewed that illustrate the increasingly widespread application of a neurophysiologic perspective to the analysis and remediation of deficits in memory, expressive language, perception, and reading. Intervention strategies encompassing the use of visual imagery, patient self-instruction, reeducation and drill, and computer-based techniques are described. The role of the neurophysiologist in assessment, treatment planning, retraining, and discharge planning is outlined.

Brain Diseases↗
PubMed1982

Mixing sexes on a rehabilitation unit.

Sixty-one former patients were interviewed regarding their reactions to sharing a hospital room with a patient of the opposite sex. Patients under 30 years of age had more favorable responses upon initial exposure than did intermediate age (30 to 49 years) or older (50 and above) patients, but a positive shift occurred in all groups. By the time of discharge, 90% of all patients reported an overall positive reaction to the experience. The use of mixed sex rooms, by fostering a noninstitutional atmosphere, may be a useful therapeutic tool.

Adolescent↗
PubMed1981

Properties of sodium dodecyl sulfate-denatured Interleukin 2.

Murine Interleukin 2 (IL2) was denatured with sodium dodecyl sulfate (SDS) with or without concomitant reduction of disulfide bonds. Between 50 and 100% of the activity was recovered upon removal of SDS. When SDS-denatured IL2 was chromatographed on a calibrated gel filtration column in the presence of SDS, it eluted with proteins of m.w. 16,000. This value is supported by sedimentation velocity studies in SDS-containing glycerol gradients. Three activities previously associated with IL2, namely the obligatory role in thymocyte mitogenesis, helper activity in the generation of cytotoxic T lymphocytes, and T cell growth factor activity, co-purified after SDS denaturation. These results indicate that the essential component of murine IL2 is a peptide of m.w. about 16,000. The 3 species of Interleukin 2 studied so far--rat, human, and murine--thus can all exist as polypeptide chains of 15,000 to 16,000 m.w. The murine factor is normally isolated as a larger entity, of about twice this m.w.

Animals↗
PubMed1981

Translation of lymphocyte mRNA into biologically-active Interleukin 2 in oocytes.

A variant line of murine T lymphoma EL4 produces high levels of the lymphokine Interleukin 2 (IL 2) when it is stimulated with phorbol myristate acetate. We have extracted poly A+ RNA from the stimulated cells and injected it into Xenopus laevis oocytes. The injected oocytes synthesize a material with biologic and biochemical properties of murine IL 2. Namely, it stimulates the continued growth of a cloned, cytotoxic T cell line (the T cell growth factor assay) and it chromatographs on a gel filtration column (G-100) with IL 2 produced by the stimulated EL4 line. The RNA responsible for the biologic activity sediments with markers of 11 to 12S in a sucrose gradient. The IL 2 produced by injected oocytes from a given preparation of mRNA is about 1% of the amount produced by the EL4 cells stimulated originally with phorbol myristate acetate. When RNA is extracted and purified from unstimulated EL4 cells it does not induce IL 2 production in oocytes. We conclude that IL 2 is essentially protein in nature, that the protein is coded for by poly A+ mRNA, and that the amount of this mRNA increases significantly after stimulation of the variant EL4 cells with the inducer phorbol myristate acetate.

Animals↗
PubMed1980

Interleukin 2 in cell-mediated immune responses.

The lymphokine Interleukin 2(IL2) restores T cell responses in a number of in vitro systems where immunogenicity has been compromised. UV irradiation of the stimulating allogeneic cells in a mixed leukocyte culture eliminates the production of cytotoxic T lymphocytes and greatly reduces the DNA synthesis response. IL2 restores both parameters. UV-irradiated stimulators are also unable to induce the normal production of IL2 which is observed in a mixed leukocyte culture. The cytotoxic activity of allogeneically stimulated thymocytes is almost completely lost within 24 hours after removal of IL2 at 5 days, indicating that the lymphokine is continuously required to maintain CTL. Thymocytes in 4-day cultures do not adsorb IL2 unless they are simultaneously activated with a mitogen. Finally, IL2 does not adequately restore a secondary response to the purified protein derivative of tuberculin (PPD) in adherent-cell-depleted cultures, indicating that macrophages, in addition to being required for IL2 production, have other functions. These probably include the presentation of soluble antigens to responding cells.

Animals↗
PubMed1980

Aldolase isoenzyme patterns during human ontogeny and in lung, kidney and breast cancer.

Enzyme patterns characteristic of fetal tissue have been noted in some experimental tumor models, particularly in hepatomas. In this study we undertook to determine whether biochemical evidence of a similar reversion could be detected in tumors of other human organs. As marker, we chose to use the aldolase isoenzymes A, B and C, for which distinct adult and fetal tissue patterns have been described. Using monospecific antibodies, we determined the aldolase isoenzyme pattern in a variety of human organs ranging in age from 14 to 40 weeks of gestation, in the 2- to 3-month postnatal period and in adults. In addition, 19 breast cancers, 19 primary lung cancers and 8 kidney cancers were examined. Our studies on breast cancer revealed three apparently distinct groups -- one showing primarily the A isoenzyme type (6 cases), a second containing mainly A with considerable quantities of B and C isoenzymes (9 cases) and a third group (4 cases) which may contain a different isoenzyme altogether since the combined activity of the three known forms was less than 100% in each case. In lung cancer, fetal characteristics could be substantiated since in fetal and adult lung tissue, the isoenzyme pattern is almost identical; 3 out of 19 cases showed substantial quantities of the B isoenzyme. In kidney tumors, a reversion to the A form with an appreciable fraction of the C form was found, which is similar to the fetal pattern.

Adenocarcinoma↗