Major pol gene progenitors in the evolution of oncoviruses

The genetic relationships among molecularly cloned prototype viruses representing all of the major oncovirus genera were investigated by molecular hybridization and nucleotide sequence analysis. One of the major progenitors of the pol genes of such viruses gives rise to mammalian type C viruses and another gives rise to type A, B, D, and avian type C oncoviruses. Evidence of unusual patterns of homology among the env genes of mammalian type C and D oncoviruses illustrates that genetic interactions between their progenitors contributed to the evolution of oncoviruses.     

Infiltrating Foxp3+ Regulatory T cells and Histopathological Features in Canine Classical and Spermatocytic Seminomas

In humans, regulatory T (T reg) cells are known to play a critical role in both the regulation of immune homoeostasis and the progression of cancer. However, there is little information about the identification, characterization and the function of T reg cells in canine tumours. We identified T reg cells in 28 canine seminoma samples using a Forkhead box P3 (Foxp3) antibody and investigated the relationship between T reg cell infiltration and histopathological features of classical and spermatocytic seminomas (SE and SS, respectively). The Foxp3 protein showed nuclear immunostaining in infiltrating lymphocytes, and Foxp3+ cells were diffused or focally distributed in seminoma tissues. Foxp3+ cells were frequently present in the SS histotype, in seminomas that showed no evidence of tumour cell invasion into the vessels and in seminomas showing a diffuse growth pattern with three cell types. Neither the SE/SS histotype nor the histopathological features of the tumour correlated with Foxp3+ cell counts. These results indicate that Foxp3+ T reg cells may be associated with a less malignant histological phenotype or may not play a critical role in the immune response of canine seminomas. Moreover, Foxp3+ T reg cells may be associated with SS seminoma, but further studies, involving a larger number of samples, are required to better understand whether these cells play a critical role in the immune response in canine seminomas. This is the first report to demonstrate the characteristics of T reg cell infiltration in canine seminoma.     

Effect of Dimethyl Sulfoxide on Cell Cycle Synchronization of Goldfish Caudal Fin Derived Fibroblasts Cells

Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin‐derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.     

Temporal changes in metal levels of the lichens Parmotrema praesorediosum and Ramalina stenospora,Southwest Louisiana

Two species of lichen native to southwest Lousiana, Parmotrema praesorediosum (Nyl.) Hale and Ramalina stenospora, Mull. Arg. have been investigated as air pollution monitors. Over the period 1983–88 samples were collected at 18 stations in the Lake Charles/Westlake/Sulphur area. The samples were analyzed for A1, Fe, Cu, Pb, Cd, Hg, Cr, and Zn. When metal concentrations in lichens were plotted vs year for certain representative stations, a dramatic reduction in the concentrations of certain metals was seen after 1983. When the most recent data are compared with those previously obtained, the effects of the industrial zone, which was previously demonstrated, have now all but disappeared.     

The identification of point sources of heavy metals in an industrially impacted waterway by periphyton and surface sediment monitoring

Periphyton and sediment samples were collected from 12 stations along Bayou d'Inde, a very polluted waterway, in Southwestern Louisiana. The samples were analyzed for Zn, Cu, Pb, Ni, Fe, Cr, Al, Cd, and Ag. When metal concentrations in periphyton or sediment are plotted vs sampling station, the metal distributions clearly indicate a major point source of metals at one station which is located at the mouth of an industrial ditch. Metal levels in periphyton generally parallel those found in surface sediments at the same location, but metal levels in periphyton are generally higher than in sediment from the same location, indicating an enrichment over sediment values. For sediments two types of extraction were investigated using leaching with concentrated HNO₃ in a high-pressure decomposition vessel and shaking with 1 N HCl for 2 hr. Both methods correlate well for all metals except Ni, but HNO₃ extracted more total metal. Correlations between periphyton and sediment were best for Pb, Fe, and Ag. Poorest correlations were seen for Mn, Ni, and Cd. When periphyton and sediment metal concentrations were normalized to Fe, Mn, and Al, correlation factors for some metals improved while others deteriorated.     

Large odd-numbered carbon clusters from fullerene-ozone reactions

The odd-numbered carbon clusters C(119), C(129), and C(139) have been observed in the mass spectra of toluene extracts of fullerene soots and of the products of ozone-fullerene reactions. Specifically, ozone-C(60) reactions yield C(119), ozone-C(70) reactions yield C(139), and ozone-(C(60)/C(70)) reactions produce C(119), C(129), and C(139). These unexpected species correspond to dimers of C(60), C(60)/C(70), and C(70), respectively, less one carbon atom, and are stable gas-phase ions with behavior similar to that of fullerenes. The results suggest a new route to functionalization and derivatization of fullerenes through controlled ozone-catalyzed cage-opening reactions.