Factors affecting RNA synthesis in rat bone-marrow cells

Neutrophils which are the first type of cells observed in the course of an inflammatory response to injury, are severely depleted in bone-marrow cells of animals after injection of antigens and insoluble thrombin, both of which provoke an inflammatory response. Increased RNA synthesis in neutrophils on phagocytosis of solid particles has also been reported. Since inhibitors of RNA synthesis in vivo can prevent the mobilisation of lymphocytes but not of neutrophils to the damaged area, and the arrival of lymphocytes is dependent on prior presence of neutrophils, it is possible that RNA synthesized in neutrophils controls the mobilisation of lymhocytes in the inflammatory response. Consistent with this hypothesis is the finding that neutrophils disintegrate after phagocytosis thus RNA so released could be taken up by lymphocytes. A study was therefore conducted on the effect of various chemotactic and phagocytosis - promoting factors on H3-uridine incorporation into RNA by rat bone-marrow cells. These cells have a high concentration of neutrophils. Chemotactic factors, anti-genantibody complexes, fibrin and fibrinogen had little effect on H3-uridine incorporation into RNA. A delipidized bovine plasma fraction, which has fibrinolytic activity, stimulated the incorporation of H3-uridine into these cells. A study of phagocytosis-promoting globulin led to the purification of a post-heparin lipoprotein lipase enzyme which stimulated RNA synthesis in bone marrow cells and also in peritoneal neutrophils. The results suggest that this enzyme increases RNA synthesis in neutrophils by affecting the plasma membrane. This could be an important reaction in the control of the inflammatory response(AU)

Insulin and growth hormone inter-relationships in vitro and in vivo - abstract

The effect of growth hormone on insulin release was observed in rabbit pancreas in vitro. Isolated islets and pancreas slices were incubated with varying concentrations of human growth hormone. Insulin released in the medium was measured by double antibody immunoassay. Human growth harmone stimulated insulin release in both pancreas preparations (p=.01). However the response was concentration dependent in that insulin release was inhibited at high concentrations of growth hormone. These observations support the concept that growth hormone plays a physiological role in the control of insulin release. Correlation between insulin and growth hormone levels in vivo was investigated in infants recovering from malnutrition. Plasma immunoreactive insulin was measured by a specially modified assay which descriminated between 0, 3, 6 and 12 uu/ml (P=.01). Growth hormone assay was equally sensitive, detecting 0.16 uu/ml. Fasting hormone levels were observed during acute malnutrition, rapid catch-up growth and recovery. In 19 acutely malnourished children insulin levels were low (2.3ñ0.3 uu/ml) (mean ñ SEM) while growth hormone levels were high (32.5 ñ 7.1). During the phase of rapid growth, insulin levels were significantly increased (4.5 ñ 0.6) (p = 0.025) while growth hormone level was 21.7 ñ 4.1. When growth curves plateaued with recovery, mean insulin level was 2.8 ñ 0.3 while growth hormone was 17.6 ñ 3.4. It is concluded that rapid catch-up after protein-calorie malnutrition is associated with a significant elevation of plasma insulin (AU)

Immunological studies on leakage of heart antigens in Jamaican cardiomyopathies

Antibodies to cow-heart tissue were prepared in mice. These antibodies were used to demonstrate the presence of cardiac antigens in sera of patients with cardiac disease. Normal individuals gave positive reactions, but to a lesser extent (AU)

Polyamines in human serum

Antibodies to Spermine have been prepared in the mouse, rabbit and goat using Sperminated Lysozyme or BSA Spermine as antigens. The reaction between the antiserum and the antigen is inhibited by the tetramine spermine, and the triamine spermidine but not by the diamines putrescine and cadaverine. This antiserum precipates with certain human sera and this has been used as the basis of a qualitative immunoelectrophoretic test for spermine in human sera. It has been found that the sera from patients with cancer and infection give a positive reaction, whilst those from patients with other pathological conditions, examined to date, are negative. The antigen responsible for the precipitation migrates in the region of O2 lipo-proteins with the spermine moiety bond to lipid as a lip-spermine complex. The results are discussed in the light of other lipo-spermine complexes found in human malignant tissue and in bacteria (AU)