[Osteoarticular infections in children]. / Infecciones osteoarticulares en niños.

We presented a retrospective review of osteoarticular infections diagnosed at Sant Joan de Deu Hospital from Barcelona, in the last 10 years (1981-1990). A total of 127 arthritis and 113 osteomyelitis were recorded in children aged from a few days to 15 years. This represents a 3.5% of all infectious diseases patients during the study period. The most common microorganism was S. aureus (52.3%) followed by Brucella (8.2%) and Salmonella as well as Streptococcus agalactiae (7.3% each). The most common involved joint were hip and knee in arthritis cases, but long bones (tibia and humerus) in osteomyelitis cases.

Promotion of L1210 tumour growth by macrophages.

Low numbers (10(4)) of peritoneal exudate L1210 mouse lymphoma cells were injected into DBA/2 mice subcutaneously and the development of tumours was followed. Tumour takes occurred in 100% of the animals within 9 days after tumour transplantation. The latent period of tumour development was prolonged by 6-10 days when tumour cells of the peritoneal exudate, depleted of adherent/phagocytic cells, were used in the inoculum or when tumour cells derived from continuous cell cultures were used. Addition of adherent cells in high numbers to in-vitro-derived L1210 cells accelerated tumour growth. This effect was found to be not specific for adherent/phagocytic cells, as liver cells had the same influence on tumour growth. It is concluded that, under certain experimental conditions, a cell population with the functional properties of macrophages is able to promote tumour development, most likely due to their non-specific effect on the micro-environment of the growing tumour.

[Quantitative and functional response of a lymphatic subpopulation during adjuvant intermittent chemo-immunotherapy in breast cancer]. / Quantitatives und funktionelles Verhalten lymphatischer Subpopulationen unter einer adjuvanten intermittierenden Chemoimmunotherapie beim Mammacarcinom.

In this study, an attempt was made to describe and evaluate in vitro immune parameters in patients with breast cancer undergoing modified radical mastectomy and adjuvant chemoimmunotherapy. T and B lymphocytes and their in vitro functions were markedly reduced by intermittent combination chemotherapy with adriamycin and cyclophosphamide. Laevamisole was not found to influence immune parameters, neither when given between chemotherapy treatments nor when given after chemotherapy. Lymphocytes expressing Fc receptors and mediating antibody-dependent cell-mediated cytotoxicity were less affected and were even found to be elevated in some patients prior to initiation of therapy. Whether or not antibody-dependent cell-mediated cytotoxicity plays a role in patient defense against tumors remains to be investigated.

Adjuvant and suppressor activity of the polycation protamine hydrochloride in the primary immune response of mice.

The effect of protamine hydrochloride (PH), a polycation, on the primary immune response of mice to sheep red blood cells (SRBC) was studied. Like other adjuvants, PH enhances or depresses the immune response depending on the time of injection of PH in relation to the antigenic challenge. The suppressive effect of PH correlated with the appearance of "activated" macrophages in the peritoneal cavity. A second injection of PH together with antigen abolished this suppressive effect. Transfer of "activated" macrophages resulted in an enhanced immune response when antigen was administered at the time of transfer, and in a depressed response when the antigen was given 1 or 2 days after transfer. It is concluded that the duration of the influence of "activated" macrophages on T or B cells determines the subsequent immune reactivity. It is discussed that the basic mechanism of action of PH is its ability to release lysosomal enzymes from macrophages. The mechanism by which these enzymes amplify the immune response remains to be clarified.

Polyclonal stimulation of lymphocytes by macrophages.

To analyze the interaction between macrophages and splenic lymphocytes with reference to time and concentration, the Mishell-Dutton system was divided into two experimental steps. Step 1 consisted of the cocultivation of spleen cells with various doses of macrophages for different periods of time, while in step 2 macrophages were removed, spleen cells transferred to fresh petri dishes and cultivated until plaque assay. Cocultivation of spleen cells with high doses of macrophages for 4--8 h markedly enhanced the DNA synthesis and plaque-forming cell (PFC) response of sheep red blood cell-stimulated and unstimulated cultures. A cocultivation longer than 24 h resulted in an inhibition of both DNA synthesis and PFC response of spleen cells. These studies suggest a nonspecific function of macrophages on proliferation and differentiation processes in antibody formation.

Histocompatibility testing in dogs. II. Leukocyte typing in relation to the mixed lymphocyte culture (MLC) reactivity.

The correlation between MLC reactivity (LD) and serological leukocyte typing (SD) was studied in a beagle colony. Disparity for a serologically defined non-DL-A lymphocyte antigen did not correlate with MLC reactivity. Lymphocytes of colony members with common ancestors and SD identical DL-A haplotypes did not stimulate each other in the MLC. This implies that LD typing in the beagle coolony can be generally predicted by DL-A SD typing. Consequently, lymphocytes of sibs homozygous for a given DL-A SD haplotype could be shown, with few exceptions, to be also homozygous for MLC determinants. Cells of these homozygous sibs can be used in MLC typing as reference cells for DL-A LD specificities. Two exceptions to the expected linkage between DL-A SD typing and MLC reactivity were found. These findings could not be explained by recombination with the DL-A region assuming a single major LD locus coding for MLC. Thus, suggestive evidence for more than one single LD locus has been obtained.