Biomedical subjects

D S Nelson

Publications and source records attributed to D S Nelson.

At least 127 records · Page 7Linked to original sources

PubMed1975

Further observations on the immunological induction of DNA synthesis in mouse peritoneal macrophages. Role of products of activated lymphocytes.

Subcutaneous injection of ovalbumin (OA) into mice immunized with OA in Freund's complete adjuvant was followed by an increase in the numbers of peritoneal macrophages synthesizing DNA, determined by autoradiography. The effect was immunologically specific. The increase was followed by an increase in the numbers of peritoneal macrophages; the numbers of peritoneal lymphocytes also increased. Injection of OA into immunized or normal mice was followed by a blood monocytosis. Increased DNA synthesis, determined by liquid scintillation counting, occurred in spleen or lymph node cells from immunized mice, cultured with OA. Diluted supernatants from such cultures, injected intravenously into normal mice, caused increases in the numbers of DNA-synthesizing peritoneal macrophages. Similarly, supernatants from concanavalin A stimulated spleen cells, freed of Con A, also caused an increase in DNA-synthesizing macrophages.

Animals↗

PubMed1975

Role of a non-committed accessory cell in the in vivo suppression of a syngeneic tumour by immune lymphocytes.

CBA/J mice bearing a methylcholanthrene-induced sarcoma exhibited concomitant immunity to the tumour. The cellular basis for this immunity was investigated by local transfer of mixtures of lymphoid and tumour cells into the footpads of syngeneic mice. Peritoneal exudate cells obtained from tumour-bearing mice 1 day after intraperitoneal injection of saline had a marked tumour-suppressive effect, whereas normally resident peritoneal cells did not. Peritoneal exudate cells from which adherent cells had been removed ('lymphocytes') had a suppressive effect at high or low lymphocyte: tumour cell ratios in normal recipients. In irradiated (450 R) recipients the lymphocytes were suppressive at high ratios only. At low ratios the lymphocytes were suppressive only if the irradiated recipients had been partially shielded or if the lymphocytes were admixed with peritoneal exudate cells from normal mice. It is concluded that an amplifying mechanism, possibly involving macrophages, can operate in tumour cell suppression initiated by immune lymphocytes.

Animals↗

PubMed1975

Depressive effect of serum from patients with leprosy on mixed lymphocyte reactions. Influence of anti-leprosy treatment.

Mixed leucocyte cultures, from two normal donors, were set up in media containing human serum from one of the following sources: (a) a pool of normal group AB donors; (b) Chinese, Malay or Indian patients with untreated leprosy; (c) the same patients after effective anti-leprosy treatment; (d) control Chinese, Malay or Indian subjects. Transformation was estimated by measuring the incorporation of tritiated thymidine in the last 24 hr of a 7-day culture period. Transformation was impaired in sera from treated lepromatous patients, but was less impaired or not impaired at all in sera from treated lepromatous patients. The loss of depressive activity after treatment was more marked in Chinese and Indian than in Malay patients. Transformation was also impaired, though to a lesser extent, in sera from patients with untreated tuberculoid leprosy; it was still impaired in sera from treated tuberculoid patients. There was no evidence of specificity in impairment of mixed lymphocyte reactivity and lymphocytotoxic antibodies appeared to play no role. The incidences of hepatitis B antigen and antibody and of anti-nuclear factor were not notably high.

Adolescent↗

PubMed1974