[Development of the diaphragmatic muscle].

Muscle biopsies were taken at the oesophageal opening and in the costal part of the diaphragm from 15 foetuses (aged between 11 and 40 weeks) and from four children aged 1 week, 5 months, 3 and 16 years. Subjects with multiple congenital abnormalities or neuromuscular diseases were not included in this study. Enzyme histochemistry (myosin ATPases) and immunohistochemistry using antibodies directed against vimentin, desmin, titin and different isoforms of the myosin heavy chains (MHCs) were carried out on serial frozen sections.

Chromatin structure and nucleic acid synthesis in human lymphocyte activation by phytohemagglutinin.

Alterations in chromatin structure were explored as a function of time following phytohemagglutinin (PHA) activation of human lymphocytes. Nuclear refringency (related to chromatin status), ultrastructural changes, and modifications of nucleic acid synthesis were compared. Chromatin dispersion was observed within 20 min of stimulation, with a concomitant increase in [3H]uridine incorporation; both were inhibited by actinomycin D.

The enhancement of interleukin 2 like production after in vivo stimulation of rat lymphoid cells by an acute non specific inflammatory process.

Interleukin 2 (IL 2) production was studied in lymphoid cells from rats undergoing an acute non specific inflammatory reaction induced by intrapleural injection of calcium pyrophosphate. Spleen and lymph node cells derived from inflamed animals had an increased level of IL 2 like production compared to cells from normal animals. Thymocytes also showed enhanced IL 2 like production although the absolute levels were lower than spleen or lymph node cells.

Lymphocyte nuclear refringence in two inbred strains of rat. Modifications of NRT during adjuvant arthritis.

Nuclear refringence test (NRT) was studied in two inbred strains of rats: Lewis (LEW) and Wistar AG (WAG), the first develops a severe arthritis while the later only slight inflammation. Before adjuvant injection, a good NRT to ConA, PHA and Isoprinosine was observed in LEW but a poor one in WAG. After adjuvant injection a striking difference appears between the two strains concerning ConA response: in LEW the response is significantly lower on day 14, while in WAG the initial poor response is not modified.