Recombinant granulocyte-macrophage colony-stimulating factor restores deficient immune responses in mice with chronic Trypanosoma cruzi infections

Spleen cells from mice with chronic Trypanosoma cruzi infection generate a minimal plaque-forming response to SRBC in vitro. Addition of granulocyte-macrophage (GM)-CSF to cultures of spleen cells from chronically infected mice restored the plaque-forming cells (PFC) response to normal levels. Splenic adherent cells from chronically infected mice were deficient in their ability to reconstitute the PFC response of accessory cell-depleted normal spleen cells. Preincubation of splenic adherent cells from infected mice with GM-CSF restored their ability to reconstitute the PFC response of adherent cell depleted cultures. Ia Ag expression by splenic adherent cells from chronically infected mice was significantly lower compared to Ia Ag expression of cells from normal mice. Incubation of splenic adherent cells from chronically infected mice for 48 h with GM-CSF increased levels of Ia Ag expression to approximately those of uninfected mice. Peritoneal macrophages from infected mice produced IL-1 after incubation with GM-CSF at levels equivalent to those produced by similarly treated control macrophages. Spleen cells from chronically infected mice showed significant induction of IL-2 mRNA after GM-CSF treatment, and the addition of the anti-IL-2 mAb to GM-CSF supplemented cultures of spleen cells from infected mice blocked the restoration of the anti-SRBC PFC response. Thus, the ability of GM-CSF to restore the anti-PFC response to SRBC appears to involve the up-regulation of accessory cell function that includes increased Ia Ag expression and the induction of IL-1 production. These events also involve increased IL-2 production with resultant up-regulation of the response to SRBC by spleen cells from infected mice. Finally, it was shown that treatment of infected mice with rGM-CSF completely restored their depressed PFC production in vivo.     

Preliminary crystallographic study of C-reactive protein from Limulus polyphemus

Crystals of C-reactive protein from Limulus polyphemus have been grown both with and without calcium. The space group for the calcium-free crystals is I422 or I4(1)22, and the cell parameters are a = b = 173.33 (4) A, c = 98.81 (3) A. The crystals diffract to at least 2.8 A resolution and are suitable for detailed structural studies.     

Morphological and Anatomical Characterization of the Coleoptile of Triticum aestivum with Regard to the Evolution of Forms with Different Ploidy Levels

Details of the morphology and anatomy of the coleoptile of wheatplants are given; these have not been described adequately previously.The investigations focussed on the hexaploid summer wheat Triticumaestivum L. cv. Hatri, and three taxa with different ploidylevels. In darkness the longitudinal growth of the coleoptile was delayedby nearly 24 h but the final length, reached after 120 h, wasdouble that of coleoptiles of plants cultivated under continuouslight. As soon as the coleoptile has grown, the primary leafpushes through a pore pre-formed during the meristematic stageand located 1–1·5 mm behind the apex. The poreis stabilized mechanically by anastomosing of the originallyfree ends of the vascular bundles, as well as by increased lignificationin this region. The species investigated differ in length, f.wt and d. wt, size of epidermal cells, and especially in thesize of guard cells of the coleoptiles. The number of parenchymalayers, however, shows no specificity. Triticum aestivum L. cv. Hatri, wheat, coleoptile, morphology, anatomy, Aegilops spp     

Animal models in the study of vomiting

The emetic responses to various pharmacological agents, cytotoxins, and radiation are compared among animal species. The species included for comparison are the human, nonhuman primate, dog, cat, and ferret. The categories of pharmacologic compounds include both those compounds that act on identified membrane receptors (e.g., cholinergic agonists, catecholamines, and neuroactive peptides) and those that act on unidentified receptors (e.g., cardiac glycosides and Veratrum alkaloids, among others). Emphasis is placed on emetic dose-response relations and threshold ED50 and ED100 values calculated from these relations, as indices of species sensitivity to emetic stimuli. For the more noxious emetics, the cytotoxins and radiation, the latency to the first emetic episode and duration of emesis are also compared across species. The effect that peripheral and central nerve lesions have on species differences in emetic responses to stimuli is also discussed.