Adherent, trypsin-resistant, peritoneal cells from mice with chronic schistosomiasis mansoni, and from control mice, were cultivated in vitro up to 20 days. Fibroblasts regularly appeared, about 6 days after seeding, in cultures ofthe manyfold more numerous cells from infected mice, concomitantly with a dramatic increase, detected by autoradiography, in the percentage of DNA-replicating cells of the monocyte-macrophage lineage. Peritoneal cells from healthy and from infected mice were fractionated on discontinuous Percoll gradients. Eight cell subsets were harvested in both cases, quantitated, and studied by electron microscopy. Two fractions (2 and 3: 1.041 < densities < 1.060 g/ml) from infected mice were greatly enriched in monoblasts and promonocytes. The cells of the different subsets were seeded separately, trypsin-treated and cultivated in vitro. Cultures of cell fractions 2 and 3 from infected mice contained the majority of the DNA-synthesizing cells and gave regularly rise to fibroblasts. Cultures of the different fractions were used for sequential morphological observations (2-11 days) at the electron microscope level. Early cultures were also used for the ultrastructural detection of the Mac-1 (CD 18/CD11b) surface antigen by gold immunocytochemistry. A few fibroblasts were rarely observed in cultures of fractions 2 and 3 from control mice, while cells with ultrastructural features of myofibroblasts were regularly observed in cultures of the same fractions harvested from mice with chronic schistosomiasis. Fractions 2and 3 from infected mice contained a large number of Mac-1 positive monoblasts. The correlations between the presence of monoblasts, DNA replication in cells ofthe monocyte-macrophage lineage and the appearance of myofibroblasts in culturesof the same fractions derived from infected mice are discussed.
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The nature and causes of the disappearance of Neanderthals and their apparent replacement by modern humans are subjects of considerable debate. Many researchers have proposed biologically or technologically mediated dietary differences between the two groups as one of the fundamental causes of Neanderthal disappearance. Some scenarios have focused on the apparent lack of plant foods in Neanderthal diets. Here we report direct evidence for Neanderthalconsumption of a variety of plant foods, in the form of phytoliths and starch grains recovered from dental calculus of Neanderthal skeletons from Shanidar Cave, Iraq, and Spy Cave, Belgium. Some of the plants are typical of recent modern human diets, including date palms (Phoenix spp.), legumes, and grass seeds (Triticeae), whereas others are known to be edible but are not heavily used today. Many of the grass seed starches showed damage that is a distinctive marker of cooking. Our results indicate that in both warm eastern Mediterranean and cold northwestern European climates, and across their latitudinal range, Neanderthalsmade use of the diverse plant foods available in their local environment and transformed them into more easily digestible foodstuffs in part through cooking them, suggesting an overall sophistication in Neanderthal dietary regimes.
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