Acta Medica Okayama volume29 issue5

Formation of 5'-AMP, 5'-GMP, 5'-CMP and 5'UMP was confirmed in isolated rat liver mitochondria incubated with alpha-ketoglutarate, inorganic phosphate, purine nucleoside and pyrimidine nucleoside. Increased incorporation of 32Pi into ATP, GTP and UTP was observed by adding purine- and pyrimidine nucleosides. The phosphorylation of nucleosides was inhibited severely by arsenite and affected slightly by the addition of nuclear or post-mitochondrial fraction.

In vitro transformations of brain cells of hamsters of various ages were examined after the administration of human adenovirus type 12 (Ad 12) to determine the type and origin of the target cell. Hamster brain cells at all examined ages were transformed by Ad12. Although the virus was not isolated, virus specific tumor antigen was demonstrated in the transformed cells. The histological features of tumors that developed by transplantation of transformed cells closely resembled Ad12-induced brain tumors. The transformed cell focus tended to appear near the embryonic brain cell (EB cell) or glioblastic cell (GB cell). The transformed cells were morphologically similar to the EB or GB cell. Some subcultured transformed cells showed a rosette-like pattern, and the surrounding space arrangement was similar to that of the ventricular wall. The incidence of brain cell transformations decreased with increased hamster age. This decreased incidence with age corresponded to the decreased numbers of EB or GB cells present in progressively older hamsters. From these results, it is concluded that the target cells of AD12 in hamster brain cell cultures are probably the EB or GB cells.

Two alpha1-globulin bands of fetal serum with relative mobilities against bromophenol blue of 0.55 and 0.58 on 7% polyacrylamide gel electrophoresis reacted with a monospecific rabbit antiserum to alpha-fetoprotein (AFP). The former globulin band was clearly detected in the fetal liver supernatant. AFP was immunochemically purified from both the fetal serum and liver, and their electrophoretic and immunochemical properties were compared. Liver AFP purified by immunoadsorbent column yielded electrophoretic mobilities and relative amounts of the two electrophoretically distinct components identical with the purified serum AFP. The immunological reactivity of the two components of the purified preparations from serum and liver against the monospecific anti-AFP serum was also indistinguishable. After the removal of the sialic acid residues from purified serum and liver AFP by treatment with neuraminidase for 6 to 12 hr, disc electrophoretic patterns on 5% polyacrylamide gel and immunoelectrophoretic patterns of the treated AFP were found to be closely similar in both preparations. It may be possible to conclude that serum and liver AFP are structurally indistinguishable and probably identical.

Glucocorticoid effect on thyrotropin-releasing hormone (TRH)-induced prolactin (PRL) release was studied in female patients with collagen or autoimmune diseases. Long-term, high dose glucocorticoid therapy tended to inhibit the response of plasma PRL to TRH. A negative correlation (r=-0.40) was found between the logarithm of total dose of glucocorticoids received and the magnitude of plasma PRL response to TRH (p less than .05).

In vitro transformation of brain cells of hamsters at various ages was examined after the addition of bovine adenovirus type 3 to determine the type and origin of the target cells. Cellular transformations occurred only in cultures of fetus and newborn animals and at low incidences. Nine cell lines were obtained. Virus specific tumor antigens were demonstrated in the transformed cells. The present investigation suggested that bovine adenovirus type 3 might transform mesenchymal cells (ME cell) and that these cells are probably of meningeal or vascular origin. The histological picture of tumors following transplantation of the transformed cells resembled human primary sarcoma of the meninges and brain.

Acute myeloblastosis and several forms of tumor, including one case of lymphosarcoma occurred when avian myeloblastosis virus (BAI-A strain) was inoculated into newly hatched chicks (SPF). The homogenate of lymphosarcoma inoculated intraperitoneally into other newly hatched chicks induced a high incidence of erythroblastic leucosis. Electron microscopy did not reveal the presence of C-type virus particles in the tumor tissue. The relationship between avian myeloblastosis virus, lymphosarcoma and erythroblastic leucosis is discussed.

Native and heat-treated RNAs from the purified Schmidt-Ruppin strain of Rous sarcoma virus (RSV) were fractionated by sucrose density gradients in the presence of ribonuclease inhibitor diethyl-pyrocarbonate and observed by electron microscopy. The structure of native 60-70S RNA was classified into two forms: tanglefolded type and linear type. In the tangle-folded type double stranded portions were observed in several sites. A high frequency of 60-70S RNA were 1.0 mum and 3-3.5 mum in length. Molecules with length about 9mum were of the tangle-folded type while molecules shorter than 6 mum were of the linear form. The structure of heat-treated RNA(30-40S) was linear with the most frequent length being 1-1.5 mum. These results indicate that native 60-70S RNA is folded with the total molecular length being in the order of 6 to 9 mum. Molecules about 3mum long are likely to be the main subunits of 60-70S RNA, and they are fragmented further into smaller subunits of about 1 mum length.