Biomedical subjects

H Blomgren

Publications and source records attributed to H Blomgren.

At least 199 records · Page 11Linked to original sources

PubMed1975

Reduced capacity to produce specific 'effector' cells after injection of CBA mice with C3H cells.

Lymphocytes from mice of strain CBA are strongly MLC-responsive to lymphocytes from the H-2-compatible but M-antigen-incompatible strain C3H. This strong reactivity disappears after infusion of CBA mice with C3H lymphocytes. This study shows that the host-versus-graft reactivity (swelling of local lymph node after antigen injection) is specifically reduced after injection of CBA mice with C3H times CBA spleen cells. However, lymphocytes from such mice showed a specifically increased GVH reactivity (inhibition of erythroid cell growth) compared with lymphocytes from unimmunized mice. Lymphocytes from normal CBA mice showed a high proliferative rate in the spleens of irradiated C3H times CBA mice. Such 'educated' cells showed strongly increased specific GVH reactivity. Lymphocytes from CBA mice previously injected with C3H times CBA cells showed reduced capacity to proliferate when injected into irradiated C3H times CBA hybrids and a poor capacity to develop new 'effector' cells reactive against C3H times CBA bone marrow target cells. The results indicate that the presence of specifically 'MLC-responsive' lymphocytes in a lymphoid cell population is a prerequisite of its production of 'effector' cells able to respond in this GVH assay.

Animals↗

PubMed1975

Role of B cells in the expression of the PPD response of human lymphocytes in vitro.

Human blood lymphocytes were tested for their proliferative response to purified protein derivative (PPD) in vitro. Purified T cells showed a lower response than the orginial purified lymphocyte suspension. Purified B cells were unresponsive to PPD. Mixtures of preparations of T and B cells were stimulated to a greater extent by this antigen than anticipated by adding the responses of the two cell types tested separately. This cell synergy could largely be explained by soluble factors released by PPD-stimulated T cells, which were found to be mitogenic for B cells.

Adult↗

PubMed1975

Evidence of different cell populations in the mouse thymus releasing and responding to mitogenic factor.

The thymocyte population of mice treated with cortisone was examined at various times with respect to its relative capacity to be triggered to DNA synthesis by soluble phytomitogens or mitogenic factors (MF) released by lymph node cells exposed to phytomitogens. The capacity of the thymocyte population to produce MF in response to phytomitogen exposure was also examined. We found that the relative blastogenic activity of both phytomitogens and MF on thymocytes increased as the cell number of the thymus was reduced by the cortisone treatment. However, the reactivity to phytomitogens increased to a higher extent. During the subsequent regeneration of the organ the stimulability of the cells by phytomitogen decreased far below that of MF. The relative capacity of thymocytes to produce MF seemed to parallel their phytomitogen reactivities. One possible explanation of the results is that there exists one subpopulation of cells in the thymus more responsive to phytomitogens than to MF and another more responsive to MF than to phytomitogen. It is possible that the cells that are phytomitogen-responsive are those that can produce MF.

Animals↗

PubMed1975

Capacity of sera from patients with mammary carcinoma to promote PHA-stimulation of human lymphocytes.

Lymphocytes from patients with carcinoma have been reported to exhibit impaired immunologic reactivity and responsiveness to non-specific stimuli both in vivo and in vitro due to inhibitory serum factors. In the present investigation it is tested whether sera from patients with mammary carcinoma may inhibit the response of lymphocytes from normal donors to phytohaemagglutinin (PHA) in vitro. Neither sera from patients with newly diagnosed breast malignancy nor patients with wide spread disease differed from control patients with benign breast lesions. Serum activity did not change within 3 weeks after radical mastectomy or local irradiation but increased slightly after 6 weeks. It is suggested that the impaired PHA-responsiveness of lymphocytes in patients with mammary carcinoma is not due to blocking serum factors but to intrinsic cellular abnormality.

Adult↗

PubMed1975

Thyroid hormones and lymphoid cells.

The impact of D- and L-forms of triiodothyronine and thyroxine on DNA-synthesis of human lymphoid cells was tested in vitro. The incorporation of 14C-thymidine into DNA was increased by addition of large quantities of both types of hormone in either racemic form.

Cells, Cultured↗

PubMed1975

Release of mitogenic factor by mouse lymph node cells stimulated with PHA in vitro. Inhibition of this phenomenon by the addition of thymocytes.

Thymidine uptakes of mouse lymph node cells and thymocytes in response to phytomitogen lectins were investigated in vitro. It was observed that mixtures of lymph node cells and thymocytes yielded higher 3H-TdR incorporations than expected when exposed to concanavalin A (Con A) or pokeweed mitogen (PWM), but lower incorporations than anticipated with phytohemagglutinin (PHA) as a stimulant. The observed enhancement of the response could be explained by factors which are stimulatory for thymocytes released by the lymph node cells. However, such mitogenic factors (MF) were released not only by Con A and PWM exposed cells but also by PHA expose lymph node cells. Further experiments showed that the admixture of thymocytes inhibited the release of MF by lymph node cells exposed to PHA but not to Con A or PWM. Since medullary thymocytes did not exhibit any inhibitory activity, it is likely that cortical thymocytes are responsible for this effect. The mechanism by which thymocytes inhibit MF production of lymph node cells exposed to PHA is not clear. MF was efficiently produced by lymph node cells cultured with PHA in "thymocyte-conditioned" medium and the MF activity was only marginally decreased by absorption with thymocytes. The results are discussed in the light of recent findings showing that thymocytes may both enhance and depress the immune response of other lymphocytes.

Animals↗

PubMed1975

Characterization of mouse cells releasing or responding to mitogenic factor induced by phytomitogens in vitro.

Mouse lymphocyte populations exposed to mitogen were tested for their capacity to release factors that stimulate other lymphocytes to synthesize DNA or enhance their response to mitogens in vitro. The target lymphocyte for this mitogenic factor(s) (MF) was also characterized. The results showed that lymph node and spleen cells release more MF than thymocytes upon exposure to Con A, PHA or PWM in vitro. The T cells were found to be largely responsible for MF production, since cell suspensions depleted of phagocytic cells did not exhibit any decreased ability to produce MF and spleen cells from congenitally athymic (nude) mice produced no detectable MF activity. The MF stimulated thymocytes, lymph node cells, and spleen cells to synthesize DNA. Spleen cells from nude mice were also stimulated. The MF released by lymphocytes in response to Con A was found to induce DNA synthesis of lymphocytes in itself and did not require the presence of mitogen. It is concluded that phytomitogen lectins stimulate T cells to synthesize DNA and to release soluble factor(s) which are mitogenic for both T and B cells. The latter cells may thus be unresponsive to the phytomitogen, but still undergo blast transformation.

Animals↗

PubMed1975

Autoantibodies in patients with carcinoma of the breast. Correlation with prognosis.

Sera from a hundred patients with operable carcinoma of the breast and seventy-five age-matched controls were examined for antinuclear, smooth muscle, glomerular and mitochondrial antibodies by indirect immunofluorescence technique. Antinuclear and smooth muscle antibodies were found to be more frequent in cancer patients than in controls. The incidence of autoantibodies at the time the diagnosis was established was higher in patients who developed local recurrences or distant metastases within 2 years than in patients free from recurrence.

Antibodies, Antinuclear↗

PubMed1975

Effect of radiotherapy on lymphocyte cytotoxicity in vitro.

The cytotoxic functions of highly purified blood lymphocytes from patients with breast cancer were studied before and after radiotherapy. Addition of PHA or of rabbit antibodies to target cells (chicken erythrocytes) were chosen as two means of inducing lymphocyte cytotoxicity in vitro. The proportion of T and non-T-lymphocytes was determined by means of E and EAC rosette tests. The antibody-induced cytotoxocity of lymphocytes decreased following radiotherapy while that mediated by PHA remained unchanged. There was some reduction in the percentage of EAC rosette-forming cells. These results, as well as our earlier observations, suggest that the decrease in the peripheral blood of the proportion of lymphocytes with receptors for activated complement is responsible for changes in the antibody-mediated lymphocyte cytotoxicity.

Adult↗

PubMed1974