Effects of cadmium acetate and sodium selenite on mucociliary functions and adenosine triphosphate content in mouse trachea organ cultures.

The effects of cadmium acetate and sodium selenite in mouse trachea organ culture have been studied separately and in combination. Ciliary activity, morphology, rate of total protein and glycoconjugate (i.e.

Recovery of mouse embryos after short-term in vitro exposure to toxic nickel chloride.

The development of preimplantation mouse embryos in vitro was adversely affected by the addition of nickel chloride (NiCl2 X 6H2O) to the culture medium. For day 3 (4-8 cell) embryos developmental cessation occurred after 48 h in culture, in NiCl2 X 6H2O-containing medium. However, transfer to NiCl2 X 6H2O-free medium after 5 min, 1 h, and 3 h exposure, resulted in regaining of the developmental capacity for a proportion of the exposed embryos.

Effect of sodium selenite on the ciliary activity, adenosine triphosphate, and protein synthesis in mouse trachea organ cultures.

Trachea from albino mice were cut transversely into nearly identical rings and incubated in medium 199 with Hanks salts and HEPES buffer at 37 degrees C. Sodium selenite at 0.5-5 mM depressed the ciliary activity.

Concentrations of trace elements in human blood serum from different places in Norway determined by neutron activation analysis.

The concentrations of As, Fe, Hg, Sb, Se and Zn in 281 serum samples from people living in nine municipalities in Norway were determined by radiochemical neutron activation analysis. The concentrations of Br, Cl, Cs, Na, Rb, Se and Zn were determined in another set of 157 serum samples from four of the municipalities by instrumental neutron activation analysis. Higher arsenic concentrations were found in the coastal districts than in inland municipalities; otherwise no significant difference in mean values was observed between the districts.

Inhibitory effect of ricin on the development of preimplantation mouse embryos.

Preimplantation mouse embryos were exposed to ricin, a plant toxin, in vitro and in vivo. The effect was evaluated by morphological observations of the exposed embryos as well as by means of protein synthesis. Ricin was highly toxic to the preimplantation mouse embryo in vitro, the effect being greater on the 2-cell than on the 4-8 cell stage.

Freezing of mouse embryos in the oviduct.

The survival of 2-cell and 4-8-cell mouse embryos after freezing and storage in liquid nitrogen, -196 degrees C, was examined. Both isolated embryos and embryo-containing oviducts were frozen to -40 degrees C at a cooling rate of 0.3 degrees C/min, and then transferred to -196 degrees C for one week.

The use of frozen erythrocytes in macrophage studies. 2. Attachment and phagocytosis mediated by the two immunological receptors of the macrophages.

Sheep erythrocytes opsonized with IgG or C3b were frozen in various cryoprotective agents, thawed, and compared to corresponding unfrozen erythrocytes exposed to the cryoprotectants and to unfrozen erythrocytes not exposed to the cryoprotectants (controls) as test particles in macrophage attachment and phagocytosis assays. Fc-receptor-mediated attachment and phagocytosis were not influenced by the use of any cryoprotective agent tested or by freezing the erythrocytes. This was also the case with C3b-receptor-mediated attachment.

The use of frozen erythrocytes in macrophage studies. 1. Attachment to the foreign surface receptor of the macrophages.

The attachment of red cells to mouse peritoneal macrophages in vitro was tested with erythrocytes (from sheep and man) which had been subjected to different cryoprotective agents and freezing procedures. The experiments showed that with dimethylsulfoxide (DMSO) as the cryoprotective agent no difference in macrophage attachment was seen whether the erythrocytes were frozen or not. With the other cryoprotectants tested, macrophages were more efficient in attaching frozen than unfrozen erythrocytes.

Copper and zinc in human serum in Norway. Relationship to geography, sex and age.

Serum samples were collected from the adult population, age groups from 20 to 54 years, in 11 different Norwegian municipalities and analysed for zinc and copper by atomic absorption spectroscopy. Significant differences were found between several of the municipalities when the mean concentration of zinc in serum in 200 randomized samples were compared, with only two municipalities being different for copper. The values for zinc ranged from 13.

Whole-body autoradiography of 204Tl in embryos, fetuses and placentas of mice.

Whole-body autoradiography was used to study thallium uptake and retention in mice during gestation. Fifteen minutes after an intraperitoneal injection of 50 microCi 204Tl2SO4 into a 15-day pregnant mouse, thallium could be seen within the fetuses. Maximum fetal accumulation occurred 2-4 h after injection, and minimum at the last observation 4 days after injection.

Manganese-nickel interaction in a tracheal ring model system.

The effects of NiCl2 and MnCl2 on the ciliary activity in mouse trachea were observed in an organ culture system. Following exposure for 2 hours to NiCl2 (0.5 or 2.

Nickel toxicity in early embryogenesis in mice.

The development of mouse embryos was studied after intraperitoneal injection of nickel chloride in the preimplantation period. A single intraperitoneal injection of NiCl2 . 6H2O in 0.

Effect of nickel chloride and cadmium acetate on the development of preimplantation mouse embryos in vitro.

Preimplantation mouse embryos were used to investigate the toxic effect of nickel chloride and cadmium acetate on early embryo development in vitro. Embryos at the 2- and 4-8 cell stage were cultured in approximately 0.05 ml of mouse embryo culture medium (No.

Viral hepatitis in dentists in Norway.

Exceptions have occurred to the generally reported high prevalence of viral hepatitis in dentists. Thus a recent questionnaire survey (1) indicated a low risk of hepatitis in dental professionals in Norway. The present supplementary study was based on frequencies of serological markers of viral hepatitis and disclosed an exposure rate to hepatitis B insignificantly higher than that of the general population.

Salivary HBsAg in hepatitis B infection.

Hepatitis B surface antigen (HBsAg) was detected by solid phase radioimmunoassay (RIA) in mixed saliva of 15 out of 50 antigenemic patients. The salivary antigen was present in low titers for a short period of time in the acute stage of illness. Occult blood was detected in most mixed saliva samples.

Secretion of nickel in rabbit saliva.

Secretion of nickel into unstimulated and stimulated saliva of rabbits was studied after a single intraperitoneal injection of nickel chloride labelled with 63Ni. Maximum 63Ni in unstimulated saliva was obtained in specimens collected one hr after maximum serum-63Ni was reached and two hrs after the nickel administration. Compared to serum-63Ni, the secretion of isotope into saliva was low whether or not stimulation was carried out.

Autoradiography of 90Sr in developing rats.

The distribution patterns of 90Sr in five littermate, 8-day-old Wistar rats were studied by whole body autoradiography. Rats were killed 15 min, 1, 4, 24, and 72 h after a single intraperitoneal injection of the isotope. Immediately after administration, 90Sr was distributed throughout most of the soft tissues of the body.

Effect of cadmium acetate, copper sulphate and nickel chloride on organ cultures of mouse trachea.

Tracheas from albino mice were excised and cut into rings approximately 1 mm thick. After preincubation overnight in Medium 199 with 5% calf serum, they were placed into fresh medium. Cadmium acetate, copper sulphate or nickel chloride was added separately or in combination, to a final concentration of 10--200 micron.

Whole-body autoradiography of 63Ni in mice throughout gestation.

Whole-body autoradiography was used to study nickel uptake and retention in mice throughout gestation. After an intraperitoneal injection of 50 muCi 63NiCl2 into a 16-day-pregnant mouse, nickel appeared rapidly in connective tissues. Prominent sites of radioactivity 72 h after injection included the visceral yolk sac, lung, gastrointestinal tract and kidney.

90Sr placentas, embryos and foetuses of mice, evaluated by whole-body autoradiography.

90Sr is a hazardous fission product from nuclear reactions. Its transplacental passage is of particular interest because of the high sensitivity of embryos/foetuses to ionizing radiation. We have used whole-body autoradiography to study the foetal uptake and retention of 90Sr and the embryonic/foetal transfer of this isotope as a function of gestational age.

Frequency of hepatitis in dental health personnel in Norway.

Hepatitis B infection is considered a risk to dentists and their ancillary staff. To evaluate the magnitude of the risk for personnel in dental practice in Norway a questionnaire survey and a serologic investigation was performed, both disclosing frequencies of hepatitis B insignificantly higher than those in the general Norwegian population. The occurrence of anti-HBs in the general population, represented by 800 sera, appeared to be lower than the corresponding values found in Sweden and Denmark.