Properties of Boolean networks and methods for their tests

One of the major challenges in complex systems biology is that of providing a general theoretical framework to describe the phenomena involved in cell differentiation, i.e., the process whereby stem cells, which can develop into different types, become progressively more specialized. The aim of this study is to briefly review a dynamical model of cell differentiation which is able to cover a broad spectrum of experimentally observed phenomena and to present some novel results.     

POLLEN MORPHOLOGY AND DETAILED STRUCTURE OF FAMILY COMPOSITAE,TRIBE CICHORIEAE. II. SUBTRIBE MICROSERIDINAE

A survey of pollen morphology of 40 species representing eight genera of the primarily North American subtribe Microseridinae reveals seven of the eight genera to have caveate, echinolophate, tricolporate grains, Picrosia being the only taxon with echinate pollen. Sectioned grains reveal the exine to consist of an ektexine and endexine. The ektexine, composed of spines, columellae, and foot layer appears to be of two basic types, one with six or seven levels of horizontally anastomosing columellae which are reduced to a single columellar layer under the paraporal lacunae and the second, a bistratified ektexine not reduced to a single layer below the paraporal lacunae. Sectioned exines of Pyrrhopappus are unusual, having very large columellae fused to the foot layer below ridges and highly reduced columellae under lacunae. Endexine organization is similar in most of the genera. Exceptions to this are Pyrrhopappus and some species of Agoseris, which have an “endexine 2” layer. Subtribe Microseridinae is essentially stenopalynous. The pollen data support most of the relationships suggested by Stebbins in his classification. The genera Agoseris, Microseris, Nothocalais, and Phalacroseris seem to form a natural group while Krigia and Pyrrhopappus form another cohesive series. The position of Picrosia, as an advanced offshoot of Pyrrhopappus, is not supported by the pollen data.     

Effect of parathyroid extract and of glutaurine (gamma-L-glutamyl-taurine) on the manifestations of osteolathyrism

BAPN-induced osteolathyrism in young and older male rats was examined for its responses to parathormone-free, gel-filtered bovine parathyroid extract (extract P) and to glutaurine (gamma-L-glutamyl-taurine), the latter being a hitherto unknown putative hormone isolated from bovine parathyroid and reproduced by synthesis. In case of the daily administration of 20 mg BAPN + 0.2 mg extract P/100 g body weight and of 40 mg BAPN + 0.2 micrograms glutaurine/100 g body weight, both substances were found to attenuate the manifestations of osteolathyrism, to a significant extent, without, however preventing their development completely. The significantly decreased Ca, P, chondroitine sulphate and chrondroprotein values due to the administration of BAPN showed a significant, or highly significant, increase for the cartilage in response to extract P, and for both cartilage and bone in response to glutaurine, without however, attaining the control values. Additional evidence has been furnished by the present study that synthetic glutaurine is equal to the parathormone-free, gel-filtered parathyroid extract (extract P) in its attenuating effect on experimental osteolathyrism.     

Number of helper T cells and phytohemagglutinin stimulation correlate in cancer patients

Summary Mononuclear cells from 12 normal controls (co), 10 advanced untreated (c1), and 6 advanced treated cancer patients (c2) have been isolated. The numbers of mononuclear cells bearing Leu1, Leu2, Leu3, Leu2/HLA-DR and LeuM3 were measured with a fluorescence-activated cell sorter. Only the quantity of helper T cells (Leu3) was decreased in cancer patients (co: 0.89, c1: 0.32, c2: 0.44 × 10⁹/1). Expression of all other markers, including activated suppressor T cells (Leu2/HLA-DR), did not differ significantly from the control. The proliferation of the lymphocytes was determined in a phytohemagglutininculture assay. The cancer groups showed a significantly decreased response (co: 95.8 × 10⁹, cl: 28.7 × 10⁹, c2: 25.7 × 10⁹ cpm). These values correlated with the number of helper T cells but not with the suppressor T cells. Monocytes of cancer patients adsorbed significantly more immunoglobulins than the monocytes of controls. The addition of indomethacin or isoprinosine to phytohemagglutinin-culture assay increased the proliferation of lymphocytes from both the cancer patients and normal controls.Supported by the Swiss National Science Foundation