Survey of human pathogenic actinomycetes and fungi in soil from Rome and other Italian areas

As part of a study sponsored by the Ministry of Health of Italy, a research program on pathogenic actinomycetes, keratinophilic and pathogenic fungi in soil was carried out. Two hundred soil samples, collected from different areas of the city of Rome, Calabria, Emilia Romagna, Latium, Apulia, Sardinia, Sicily, Tuscany and Umbria, were examined by several techniques to detect the widest possible variety of pathogenic actinomycetes and fungi. Seven isolates ofNocardia asteroides, four ofActinomadura madurae and one ofNocardiopsis dassonvillei were isolated for the first time from soil in Italy. In addition, numerous isolates ofPetriellidium boydii, Aspergillus fumigatus, A. flavus, A. niger and keratinophilic fungi of the generaMicrosporum, Trichophyton andChrysosporium were also recovered.Presented at the VII Congress of the International Society for Human and Animal Mycology, Jerusalem, Israel, 11–16 March, 1979.     

Cytochemical localization of ouabain-sensitive, K+ -dependent p-nitrophenylphosphatase and Ca++-stimulated adenosine triphosphatase activities in human parotid and submandibular glands

K+ -dependent p-nitrophenylphosphatase (pNPPase) and Ca++ -stimulated adenosine triphosphatase (ATPase) activities were studied in human parotid and submandibular glands using cytochemical methods at the ultrastructural level. In both glands, only the striated-duct epithelium showed K+ -pNPPase reaction product, thereby indicating the localization of Na+, K+ -ATPase. The precipitate was concentrated on the deep invaginations of the basolateral plasma membranes, in close association with their cytoplasmic surface. Ca++ -ATPase activity was also found on the basolateral plasma membranes, but two striking differences from the K+ -pNPPase distribution were observed: firstly, Ca++ -ATPase appeared in both acinar and ductal cells, and secondly, it was localized on the outer side of the plasma membranes.     

Vitamin A inhibits chondrogenesis but not myogenesis

Limb bud cells were isolated from HH stage 22–23 chick embryos and were grown as a ‘spot culture’ in in vitro conditions which support their differentiation into chondrocytes and myotubes. By day 4 of culture, numerous chondrocyte nodules developed and were scattered mainly in the very centre of the cell spot. In contrast, multinucleated myotubes formed at both the centre and the periphery of the cell spot. Treatment with vitamin A starting on day 1, inhibited chondrogenesis in these cultures, and by day 4–6 chondrocyte nodules could not be detected histologically. In contrast, no dose of vitamin A tested was effective in suppressing the development of multi-nucleated myotubes. These data show that vitamin A selectively inhibits chondrogenesis but not myogenesis in limb bud cell cultures.     

Alterations of lipid composition in a dystrophic muscle cell line

The composition of neutral lipids and phospholipids was determined in normal (Cb7) and dystrophic (DyA4) cell lines, derived from cloned satellite cells from control and dystrophic C57BL/6J/dydy mice. The results obtained showed that dystrophic cells contain a higher relative distribution of phospholipids than their normal counterparts. Moreover, the distribution of individual phospholipids differs between normal and dystrophic cells, with increased percentage of acidic phospholipids and reduced proportion of phosphatidylcholine in dystrophic cells. Cholesterol was increased but free fatty acids decreased in dystrophic cells. The possible pathogenetic significance and functional consequences of these abnormalities are discussed.     

Changes in protein and glycoprotein biosynthesis during differentiation of satellite cells in vitro

Satellite cells were isolated from leg skeletal muscles of adult mice and grown in culture. During the first few days in culture, satellite cells actively proliferated and starting on day 4 began to fuse into multinucleated myotubes. At various time points during the culture period, the biosynthesis of total cellular proteins and glycoproteins was analysed by pulse-labelling with radioactive leucine or sugars followed by electrophoretic analysis on two-dimensional gels. Our findings are: (1) Replicating mononucleated satellite cells on day 1 of culture did not synthesize detectable amounts of α and β tropomyosins, α-actin, and myosin light chains 1 and 2; (2) the synthesis of these polypeptides was readily detectable in multinucleated myotubes that formed by day 5–6 of culture; (3) other qualitative and quantitative differences in as yet unidentified proteins were observed in replicating cells as compared with multinucleated myotubes as well as to muscle fibroblasts; and (4) at least two distinct glucosamine-containing acidic glycoproteins of about 70 000 D and pI 5 were synthesized by myotubes, but not by replicating satellite cells.These data demonstrate that the biosynthetic programs for proteins and glycoproteins of cultured replicating satellite cells can be distinguished from those of multinucleated myotubes and from those of muscle fibroblasts. These data are interpreted to indicate that during muscle histogenesis in vivo, satellite cells become arrested prior to the expression of terminally differentiated traits.