Combined effects of gamma rays, cis-diamminedichloroplatinum (CDDP) and systemic hyperthermia mastocytoma transplanted into muscle in the mouse

Comparison was made between the effects of local irradiation of gamma rays, s. c. injection of cis-diamminedichloroplatinum (II) (CDDP), systemic hyperthermia and their combinations on the i. m. transplanted murine mastocytoma. Increase of the mean survival time (M. S. T.) by a factor of 1.72 and of 1.68 was achieved by a single irradiation at 20 Gy, given on day 5 after transplantation, and by injections of CDDP at 2 mg/kg, given s. c. on days 5 and 12 after transplantation, respectively. Increase of M. S. T. by a factor of 1.10 which was achieved with systemic hyperthermia of 41.8 degrees C of the core body temperature for 5 min, given twice, on days 5 and 12 after transplantation, was not statistically significant. The most effective one among all possible combinations within the 3 modalities was that of radiation and CDDP. Increase of M. S. T. was by a factor of 4.01.     

Muscarinic acetylcholine receptors in rat gastric mucosa

Summary The muscarinic cholinergic innervation of the rat gastric mucosa was investigated by localizing the muscarinic receptors using a tritiated muscarinic antagonist, pirenzepine. Radioautography was performed by freeze drying stomach tissue, which was then embedded in Epon and wet sectioned with ethylene glycol, and dry mounting on emulsion film by the wire-loop method to prevent loss of the labelled substance during fixation and the radioautographic procedure. Light and electron microscopy showed that the specific pirenzepine-binding sites were localized predominantly on parietal cells, chief cells and perivascular plexuses. Analysis of the grain distribution on parietal cells revealed that the silver grains corresponding to the pirenzepine-binding sites were mainly on the basolateral plasma membrane. On the other hand, the surface mucous or mucous neck cells had few pirenzepine-binding sites.     

Sensitivity of mice to systemic hyperthermia: effect of the transplantation of ascites tumor cells modified by preheating, and by an injection of CDDP or interferon

Effects of preheating and injection of cis-DDP (CDDP) or interferon on tumor-induced sensitization to systemic hyperthermia (SH) was investigated in mice. LD50 of SH at 42.0 +/- 0.2 degrees C (core body temperature) was 43 min in normal mice and 8 min in mice which were i.p. transplanted with FMA3 cells at a dose of 10(5) one day before. In mice which had received the SH for 10 min one hour before, one hour after or one day before the transplantation, LD50 of the SH one day after the transplantation was 41, 35 and 22 min, respectively. An injection of CDDP given i.p. at a dose of 4 mg/kg one day after the transplantation, which was effective to kill about 99% of the tumor cells, did not change the course of thermosensitization after the transplantation. An i.p. injection of mouse interferon did not change the thermosensitivity of normal mice, but greatly suppressed the thermosensitizing effect of tumor cells when it was given one day before the transplantation.     

Isolation of virus causing hemorrhagic fever with renal syndrome (HFRS) through a cell culture system

Twenty-three rat lung specimens collected in outbreaks of hemorrhagic fever with renal syndrome (HFRS) in three medical institutions were inoculated onto the VERO-E6 cell monolayers. After several blind passages, an agent growing serially in the cell cultures and reacting specifically with known HFRS-positive sera was isolated from two of these specimens. The two isolates were antigenically identical each other. The agent, named strain SR-11, was identified as the causative virus of HFRS by its antigenic identity with E6 cell-adapted HFRS virus, Hantaan 76-118 strain, and the specific reactions with sera from various HFRS cases.     

Induction of human microvascular endothelial tubular morphogenesis by human keratinocytes: involvement of transforming growth factor-alpha.

Transforming growth factor-alpha(TGF-alpha), homologous to epidermal growth factor(EGF), is closely involved in hyperproliferation of human keratinocytes. Psoriasis is a common hyperproliferative skin disease characterized by hyperproliferation of keratinocytes and abnormal development of dermal capillary networks. In this study, we have examined whether keratinocytes could enhance angiogenesis. TGF-alpha or EGF efficiently stimulated formation of tubular-like structures of human omental microvascular endothelial(HOME) cells in type I collagen gels. Human keratinocytes produced TGF-alpha. To examine whether co-cultured keratinocytes could induce tubulogenesis of HOME cells in collagen gel, we have developed a co-culture system with human keratinocytes. Surprisingly, there appeared new development of many tubular-like structures of HOME cells in collagen gels when co-cultured with keratinocytes. This keratinocytes-dependent tubulogenesis was almost completely blocked when anti-TGF-alpha-antibody was present. The TGF-alpha molecules derived from keratinocytes appeared to enhance tubulogenesis of human microvascular endothelial cells. We propose the hypothesis that secretory TGF-alpha from human keratinocytes may promote an autocrine loop to proliferate the skin keratinocytes and also a paracrine loop to induce the skin angiogenesis.     

Long-Term Acceptance of Major Histocompatibility Complex-Mismatched Cardiac Allograft Induced by a Low Dose of CTLA4IgM Plus FK506

The immunosuppressant FK506 prolongs allograft survival. However, at therapeutic doses it has significant side effects. A fusion protein consisting of the extracellular portion of CTLA4 and the Fc portion of human IgG (CTLA4IgG) also prolongs allograft survival, but large doses of CTLA4IgG are required for the induction of cardiac allograft acceptance. Therefore, we constructed a pentameric form of a new CTLA4 fusion protein, CTLA4IgM. We tested whether low doses of CTLA4IgG or CTLA4IgM in combination with subtherapeutic doses of FK506 can prolong allograft survival in a synergistic fashion. C57BL/6 (H-2^b) neonatal hearts were transplanted to CBA/J (H-2^k) mice in a heterotopic, nonvascularized cardiac allograft model. The findings demonstrate that a combination of low doses of FK506 plus a pentameric form of CTLA4Ig, CTLA4IgM, leads to significant graft survival, while a combination of FK506 plus CTLA4IgG does not.     

Phosphorylation of a Protein (pp56) is Related to the Regeneration of Rice Cultured Suspension Cells

Short-term cultured suspension cells of rice (Oryza sativa L.)are capable of regeneration, but not in long-term culture. Forclarification of the mechanism of regeneration, protein phosphorylationin short-term and long-term cultured suspension cells was comparedby two dimensional- polyacrylamide gel electrophoresis. A 56kDa protein having an isoelectric point of 4.5 was phosphorylatedin vitro in short-term cultured suspension cells, but was notphosphorylated after regeneration. This protein in longtermcultured suspension cells remained phosphorylated after transferto the regeneration medium. However, using an antibody raisedagainst this protein from short-term cultured suspension cells,it was always detected in long-term and short-term culturedsuspension cells after transfer to the regeneration medium.The partial amino acid sequence of the HPLC-purified proteinshowed homology to a calcium-binding protein from maize. Thephosphorylation of the 56 kDa protein (pp56) appears to be associatedwith the regeneration of cultured rice cells. (Received December 11, 1995; Accepted June 3, 1996)