Abnormal increase in multinuclear macrophages in primary cultures of BUF/Mna rat thymomas.

The in vitro characteristics of spontaneous thymomas from BUF/Mna rats, a strain with a high incidence of these tumors, were studied. In primary cultures, the adherent cells consisted of mononuclear macrophages, mono- and multi-nuclear epithelial cells and some fibroblastic cells on day 3. The macrophages rapidly increased in number with the formation of large multinuclear cells by day 9. A modest increase in the number and nuclearity of macrophages was also noted in adherent cultures of normal thymuses from 5-week-old BUF/Mna rats. On the other hand, in cultures of thymic cells from 1-year-old or 5-week-old ACI/NMs rats, a normal control rat strain, macrophages did not increase in number and only rarely formed multinuclear cells in adherent cell cultures. These results suggest that abnormal proliferation signal(s) to thymic macrophages and/or their progenitor cells accompanies and may be involved in the development of thymomas in BUF/Mna rats.     

Human T-lymphoblastoid cell lines with high and low abilities to produce interferon-gamma constitutively and their susceptibilities to interferon

A human T-lymphoblastoid cell line, TCL-Fuj, produces large amounts of interferon (IFN)-gamma constitutively. A variant cell line, 2M, was derived from it. Both cell lines express similar surface antigen markers, but differ in surface morphology. Compared with the parent TCL-Fuj cell line, 2M produced less IFN-gamma constitutively but more in response to IFN inducers. The IFNs produced constitutively and on stimulation with inducers were analyzed by SDS-polyacrylamide gel electrophoresis. In TCL-Fuj cells, the constitutive and induced IFNs consisted of the same molecular species (22K and 39K). In 2M cells, smaller IFNs were produced constitutively (18K and 32K) and induction resulted in a marked increase of 22K molecules. These two cell lines also differed in sensitivity to the antiviral activity of IFN. Other T-lymphoblastoid cell lines, HPB-ALL and TCL-Fuj 4 cells, which did not produce IFN-gamma were permissive for vesicular stomatitis virus (VSV) replication; its growth was markedly suppressed by IFN-gamma and -alpha. TCL-Fuj cells were also permissive for VSV, but were not susceptible to the antiviral effect of the IFNs. In contrast, in 2M cells the multiplication of VSV was restricted; the viral yield was further reduced by the IFNs and increased by treatment with anti-human IFN-gamma serum. Several clonal cell lines derived from TCL-Fuj and 2M cells had characteristics similar to the respective parent cell lines. The growth of both cell lines was not affected by IFN-gamma or by -alpha. The separation of antiviral and anti-proliferative susceptibilities was peculiar to 2M cells unlike other cell lines.     

Presence of glucagon-(1-21)-Like immunoreactive substance in the dog small intestinal mucosa

By using an antiserum (K291) specifically directed to the C-terminal of glucagon-(1-21)-peptide, we demonstrated the presence of glucagon-(1-21)-like immunoreactivity (G21-IR) in the dog intestine. G21-IR was found to be widely distributed throughout the small intestine and colon in parallel with the distribution of glucagon-like immunoreactivity (GLI), measured by N-terminal glucagon antiserum (OAL196). The subsequent analyses by gel filtration and three HPLC columns (reverse phase, ion exchange and further reverse phase columns) showed that G21-IR consisted of three main peaks, and the smallest molecular form of G21-IR is identical to glucagon-(1-21)-peptide.     

Separation of DNA-dependent DNA polymerase activities in Micrococcus radiodurans.

DNA polymerase activities in Micrococcus radiodurans were separated into two fractions after purification more than 2000 fold. They differ in pH optimum and residual activities in the absence of a full deoxyribonucleoside triphosphates complement. NAD partly inhibited one of the activities. Both activities were eluted as a single peak on gel filtration and sedimented at the same rate on glycerol gradient centrifugation. Molecular weight 140000 was calculated from Stokes radius and sedimentation constant. Deoxyribonuclease activity was detected on one of the polymerase activities which preferentially degraded double-stranded DNA. Priming activity of nicked DNA was reduced by gamma-irradiation. These results have been related to the possible rolls in repair synthesis in vivo or DNA synthesis in permeable cells of M. radiodurans.     

Anion transport activity in the human erythrocyte membrane modulated by proteolytic digestion of the 38,000-dalton fragment in Band 3

Extracellular treatment of human erythrocytes with papain completely converted the chymotryptic 38,000-dalton fragment of Band 3 to the 29,000-dalton fragment and inhibited the transport of inorganic phosphate in the cells. The inhibition, however, was not complete, indicating the presence of two components in the anion-transport system: the one resistant to papain digestion and the other sensitive to the digestion. The latter activity is well correlated with the degradation of the 38,000-dalton fragment. The activity remaining in the cells treated with papain was markedly different from that of the control cells. The remaining activity was not inhibited by pyridoxal phosphate and dinitrostilbene-2,2'-disulfonic acid, potent inhibitors to the anion transport, whereas phenyl phosphate inhibited the activities of both papain-treated and control cells. The results indicate that the anion-transport system consists of multiple anion-binding sites and a part of the system which is sensitive to pyridoxal phosphate and dinitrostilbene-2,2'-disulfonic acid was located in the papain-sensitive portion of 38,000-dalton fragment. A possible model of the anion-transport system was presented.     

Primary malignant lymphoma of the uterine corpus and cervix. Report of a case with immunocytochemical analysis

In a 69-year-old woman, a gynecologic smear was the first indication of the presence of a nonepithelial malignant tumor. While first thought to represent an adenocarcinoma, malignant lymphoma was later cytologically suspected because of the presence of isolated large malignant cells with macronucleoli. The initial clinical and histologic studies failed to indicate a malignancy. The malignant cells in postoperative tissue samples showed a positive immunohistochemical reaction for leukocyte-common antigen (LCA) and a negative reaction for epithelial membrane antigen, confirming the cytologic suggestion of a uterine lymphoma. Immunocytochemical staining subsequently performed on the destained cytologic specimen gave a positive immunoreactivity to LCA in the cytoplasm of the malignant cells.