Altered intracellular localization of the glutamate receptor channel δ2 subunit in weaver and reeler Purkinje cells

The glutamate receptor (GluR) channel δ2 subunit is expressed abundantly and specifically in cerebellar Purkinje cells. Our previous study demonstrated that the GluR δ2 mRNA is expressed as early as embryonic day 15 prior to Purkinje cell synaptogenesis, and its protein product accumulates in dendritic spines during normal Purkinje cell maturation. In this study, we examined expression and distribution of the GluR δ2 in the weaver and reeler mutant cerebelli, which show abnormal cytoarchitecture and neural circuitry. In situ hybridization analysis showed that GluR δ2 mRNA was expressed in entire Purkinje cells in both mutant mice. Immunohistochemical analysis revealed that intracellular localization of GluR δ2 was altered in some region of mutant cerebelli. In the cortical surface where Purkinje cells form synapses with parallel fibers, GluR δ2-immunoreactivity was restricted to dendritic spines of Purkinje cells as observed in normal mice. In contrast, in the subcortical region where granule cells and parallel fibers are absent, the immunoreactivity was found widely in Purkinje dendrites. Thus, the GluR δ2 protein did not accumulate to the dendritic spines of Purkinje cells lacking synaptic contact with parallel fibers. These results suggest that the expression of both GluR δ2 mRNA and protein is independent of abnormalities in the mutant cerebelli, but relocalization of the GluR δ2 protein might depend on the formation of synapses between Purkinje cells and parallel fibers.     

Pure red cell aplasia after major ABO-incompatible bone marrow transplantation: two case reports of treatment with recombinant human erythropoietin

A 34-year-old man with acute myelocytic leukemia (AML: MO) and a 32-year-old woman with AML: M2 developed pure red cell aplasia (PRCA) after receiving a major ABO-incompatible bone marrow transplant (BMT). The first patient responded to recombinant human erythropoietin (rhEPO) therapy, while the second did not. The second patient also received methylprednisolone (m-PSL) but developed reticulocytosis and hemolysis after the administration of m-PSL. Plasmapheresis was then performed and the patient promptly recovered from hemolysis and PRCA. We conclude that close attention must be paid when treating PRCA following major ABO-in-compatible BMT with rhEPO and m-PSL, as there is always the potential for massive hemolysis.     

G-I hormones and gastric functions--with special reference to the pyloroplasty for the selective proximal vagotomy

Serum gastrin changes before and after selective proximal vagotomy (SPV) were studied in relation to the gastric motility and the acid secretion clinically and experimentally and the effects of pyloroplasty were investigated. Results and conclusions: Experimental studies revealed that test meals provoked gastrin secretion to stimulate gastric motility. Periodical gastric acid secretions were observed during hunger period, along with elevated serum gastrin levels. After SPV, gastrin responses to the test meals were significantly increased so that the pyloric ring motility was disturbed. Clinical studies revealed that adrenaline infusion test provoked significant gastrin responses to secrete acid secretions in duodenal ulcer patients. After SPV, increased gastrin responses to adrenaline restored acid secretions as much as preoperative acid secretions responded to the adrenaline test. Pyloroplasty for the SPV inhibited the gastrin and acid secretions responded to the adrenaline test.     

Novel macrocyclic antibiotics: megovalicins A, B, C, D, G and H. II. Isolation and chemical structures of megovalicins

Myxococcus flavescens AJ12298 was found to produce the complex of macrocyclic antibiotics named megovalicins. The physico-chemical studies revealed that megovalicins C and B were identical to myxovirescin A1 and antibiotic M-230B, respectively, and that megovalicins A, D, G and H were closely related new antibiotics.     

Autoradiographic demonstration of unscheduled DNA synthesis in oral tissues treated with chemical carcinogens in short-term organ culture

Abstract A system in which oral tissues of inbred F344 adult rats and Syrian golden hamster embryos were used in combination with autoradiography was developed for measurement of unscheduled DNA synthesis (UDS). For this, oral mucosa, submandibular gland, tooth germ and mandible in short-term organ cultures were treated with 4-nitroquinoline 1-oxide or N-methyl-N-nitrosourea plus (methyl-³H)thymidine. Significant numbers of silver grains, indicating UDS, were detected over the nuclei of cells of all these tissues except rat salivary gland after treatment with carcinogens. This autoradiographic method is suitable for detection of UDS in oral tissues in conditions mimicking those in vivo. Results obtained in this study indicated a potential use of this system for studies on the mechanism of carcinogenesis at a cellular level comparable to in vivo carcinogenesis studies on oral tissues.     

In vitro transformation of hamster embryo cells by betel tobacco extracts

In vitro carcinogenicity of betel tobacco extracts was examined in a transformation assay with cryopreserved hamster embryo cells. The ethanol extract induced a transformed colony at 100 $\text{μg}\text{ml}$ and the ethyl acetate extract induced 2 transformed colonies at $\text{5}\text{μg}\text{ml}$ and 2 at 100 $\text{μg}\text{ml}$.     

In vitro growth characteristics and heterogeneity of mouse hepatitis virus type 3

Summary Thein vitro virus yield of MHV3 reached 10⁷ PFU/ml in mouse DBT cells infected with a virus suspension in HEPES-buffered medium containing DEAE-dextran. The virus titer was 10⁶ PFU/ml in the presence of 10 µg actinomycin D/ml. MHV3 grown in DBT cells gave three peaks of density (1.10–1.14 g/cm³, 1.18–1.20 g/cm³, and 1.25–1.31 g/cm³) in sucrose gradients. All these peaks retained infectivity.With 2 Figures     

An improved method for titration of mouse hepatitis virus type 3 in a mouse cell culture

Summary Plaque assay in DBT cells with DEAE-dextran and trypsin presents a titration system for MHV3 as sensitive as the LD₅₀ assay in mice.With 1 Figure