Cytotoxicity of mouse peritoneal cells after alloimmunization]

CBA Mice were immunized by two intraperitoneal injections of 30 X 10(6) DBA/2 or C57BL/6 spleen cells at days--12 and--2. Peritoneal cell population was obtained at day zero by washing the peritoneal cavity of Mice. Adherent cells were then separated using a 2 hrs. incubation in "Falcon" plates followed by washing. This macrophage-rich peritoneal cell population was found nonspecifically cytotoxic against 51Cr labeled tumoral target cells: P815 X DBA/2 mastocytoma cells, EL4 X C57BL/L lymphoma cells and spontaneous lymphoma AKR cells (same H--2k as CBA). This adherent peritoneal cell cytoxicity was demonstrated after 24 hrs. incubation with the target cells. It was found in nonspecific combination as well as when using target cells syngeneic to the donor. These findings suggest that adherent peritoneal cell cytotoxicity could be at least partly due to macrophages and result from factor (s) released by sensitized lymphocytes in vivo in the same way as has been previously demonstrated in vitro.     

Degradation of ribosomal RNA from Escherichia coli by ribonuclease U2 and in vitro transcription of "RNA-fragments" into complementary DNA]

Under well defined conditions ribosomal RNAs purified from Escherichia coli can be degraded by ribonuclease U2 giving rise to RNA fragments of 60--70 nucleotides. In vitro, these fragments are efficiently transcribed into a complementary DNA by DNA polymerase RNA dependent, partially purified from extracts of E. coli. In vivo, "RNA-fragments-U2" inhibit the development of plant tumors.     

Effect of cortisone or triiodothyronine administration to pregnant rats on lysosomal hydrolases in fetal forebrain and cerebellum

Triiodothyronine injected daily to pregnant rats for the last week of gestation (50 microgram/100 g b.wt) increased the specific activities of 5 acid glycosidases in the fetal forebrain and cerebellum. Cortisone (50 mg/100 g b.wt) administered in the same period had no effect on cerebellum acid hydrolases, but decreased their activity in the forebrain.     

New lectin receptors in carcinoembryonic antigen (CEA).

The glycoprotein CEA (carcinoembryonic antigen) carries carbohydrate groups, which react with the plant lectins from Agaricus bisporus, Arachis hypogaea (peanut), with Tridacnin from invertebrate clams and with the anti-A lectins from snails. Accordingly, it has cryptantigenic structures, which correspond to the T or T-like antigen, the Tridacnin receptor and to the so called A-like antigen.     

Conversion of mammalian cyclic GMP-dependent protein kinase into modulator-dependent protein kinase (type II) in vitro

The spontaneous conversion of mammalian cyclic GMP-dependent protein kinase (G-PK) into modulator-dependent protein kinase (type II) (M-PKII) in the absence of cGMP or histone was observed in vitro. The findings, together with similarity in substrate protein specificity, suggest that M-PKII is the catalytic subunit of mammalian G-PK.     

Effects of thyrotrophic-releasing hormone (TRH) on thermoregulation in the rat

At ambient temperatures (Ta) of both 8 and 22 degrees C, intraventricular administration of TRH (10-80 microgram) produced a dose-dependent hypothermia in rats. The hypothermia was due to both decreased metabolic heat production and cutaneous vasodilatation. In contrast, at 30 degrees C Ta, TRH increased metabolic heat production (due to behavioral excitation) and led to hyperthermia.     

Nucleolus organizer region location and ‘ring’ chromosomes in the bharal

Summary Silver-staining has been used to identify the nucleolus organizer regions (NORs) in the bharal. These show homology with sheep, goat, cattle and aoudad. The association of the NORs on both telomeres of chromosome 3 results in a ring chromosome.     

H-Y Evolution

Summary The female: male sex ratio in litters born to C57 black mice immunized with male spleen preparations is 21 and males were stillborn. In additionDrosophila busckii males are H-Y antigen positive. It is argued that H-Y is the primary testicular determinant and that this role is evolutionarily ancient.     

Presence of natural killer cells in Peyer's patches of the mouse

Summary Natural cell-mediated cytotoxicity of normal murine Peyer's patch cells against Ehrlich ascites carcinoma was found in a short-term⁵¹Cr release assay. Peyer's patch and lymph node cells showed natural cytotoxicity at approximately the same level.Acknowledgments. This work was supported by grant No. 10.5 from the Polish Academy of Sciences.     

Epithelial-mesenchymal interaction in differentiation of duodenal epithelium of fetal rats in organ culture

Summary Epithelial-mesenchymal interaction in the differentiation of duodenal epithelium of fetal rats was investigated by recombination experiments in vitro. The proportion of goblet cells in duodenal epithelium was significantly greater on recombination of developing duodenal epithelium with mesenchyme of the glandular stomach than on recombination with that of the duodenum. Mesenchyme of the glandular stomach or forestomach was better than duodenal mesenchyme in supporting morphogenesis of duodenal epithelium. Treatment of tissues with N-methyl-N-nitro-N-nitrosoguanidine (MNNG) did not affect these tissue interactions.This work was supported by grants-in-aid for cancer research from the Ministry of Education, Science and Culture, Japan.Acknowledgment. The authors wish to express their gratitude to Prof. T. Mizuno of the University of Tokyo for valuable suggestions.