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Biomedical subjects

N Jacobsen

Publications and source records attributed to N Jacobsen.

At least 145 records · Page 8Linked to original sources
PubMed1977

Human submandibular gland tissue in culture 2. Nickel affinity to secretory proteins.

In view of the exposure to nickel through the oral cavity the relation between this metal (as 63NiCl2) and salivary macromolecules was studied by tissue culture, isoelectric focusing and equilibrium dialysis. During cultivation of human submandibular gland tissue, small amounts of nickel were incorporated into macromolecules with an isoelectric point of about 4.4 and approximately 7.5. No affinity independent of the protein synthesis was revealed between nickel and submandibular proteins, including the acidic, viscous, sulphate-incorporating glycoproteins. It is therefore possible that a nickel-containing metalloprotein is present in the submandibular secretion, but a complex formation between nickel and macromolecules similar to the nickel-albumin transport system in plasma was not found. The affinity of nickel to small molecular substances in the secretion was not studied.

Culture Techniques↗
PubMed1977

Quantitative aspects of an in vivo diffusion chamber assay for normal human hemopoietic colony forming units.

The purpose of the present study was to definite some of the quantitative characteristics of the colonies formed by normal human hemopoietic cells in diffusion chambers in vivo. The cells were cultured in fibrin clots in diffusion chambers, which were implanted i.p. into 450 R irradiated mice, reimplanted into newly irradiated mice after 7 days and harvested by a previously described chamber centrifugation technique after a total of 14 days. At low cell doses per chamber, no colonies were observed; however when more than 3-8 X 10(4) cells were inoculated per chamber, the number of granulocytic colonies was proportional to the cell dose. Similar dose-reponse curves were obtained when the cells were harvested in suspensions from the chambers. The granulocytic colonies do not conform to a Poisson distribution when identically prepared chamberbeare compared, but show a more heterogeneous distribution. Evidence is presented that this heterogeneity is not due to technical errors in the process of chamber filling and harvesting. A host factor was found to influence the mean number of cells per neutrophilic colony, but the heterogeneity of the total number of neutrophilic or eosinophilic colonies of more than five cells could not be ascribed to variable host factors. There was a mean of 3.6 granulocytic colonies (of more than 30 cells) per 10(5) cells implanted in a series of 15 normal bone marrows cultured. The mean size of neutrophilic colonies was 23 cells. Determinations in duplicate suggest that the method may serve as an assay for certain classes of colony forming cells, provided the number of chambers in each assay is sufficiently high.

Animals↗
PubMed1977

Proliferation of diffusion chamber colony-forming units (CFUD) in cultures of normal human bone marrow in diffusion chambers in mice.

Normal human bone marrow contains cells capable of forming colonies of hemopoietic cells in fibrin clots in diffusion chambers implanted intraperitoneally (i.p.) into irradiated mice. The present paper describes the proliferation of such colony-forming units (CFUD) in cultures in vivo. Cells harvested from diffusion chambers after 1-14 days of culture in 450-R irradiated mice contained CFUD, which formed neutrophilic, eosinophilic, or megakaryocytic colonies when tested by secondary culture in fibrin clot chambers. When bone marrow was precultured in irradiated mice at a concentration of 10(6) cells per chamber, an initial fall in the number of neutrophilic CFUD was observed. This decrease was followed by an increase to a maximum at day 2, and then a secondary decrease. The number of neutrophilic CFUD recovered after 2 days of preculture in irradiated mice varied between 60% and 250% of the number present before preculture. Preculture in nonirradiated mice resulted in a significantly lower recovery of neutrophilic CFUD. In vitro treatment of bone marrow cells with hydroxyurea (OHU) after 2 days of preculture in irradiated mice resulted in a 68% +/- 5% reduction in the number of neutrophilic CFUD. In contrast, OHU had no similar effect on precultures from nonirradiated mice. Both the recovery and sensitivity to OHU of eosinophilic CFUD were independent of host irradiation. Similarly, no effect of host irradiation on the recovery or the 3H-thymidine (3HTdR) labeling index of morphologically recognizable granulocytic cells was observed at day 2. The data suggest an effect of humoral host factor(s) on the proliferation of early precursor cells, which are or become committed to differentiate into the neutrophilic pathway in diffusion chambers.

Animals↗
PubMed1976

Human granulocytopoietic colonies in diffusion chambers in mice: growth of colonies and the effect of host irradiation.

Normal human non-separated bone marrow cells were cultured in fibrin clots in diffusion chambers implanted intraperitoneally in mice, and harvested at different intervals by a previously described chamber centrifugation technique. This method demonstrates the presence of cell aggregates in the diffusion chambers. When the chambers are implanted in irradiated mice (450 R) and retransplantated into newly irradiated mice every seventh day, a continous increase in number of cells per granulocytopoietic aggregate is observed from day 8 to day 21. This is compatible with the view that the aggregate is observed from day 8 to day 21. This is compatible with the view that the aggregates are colonies. The term 'colony forming unit diffusion chamber' (CFUD) is suggested to denote the ancestor(s) of the colonies. However, formal proof that one colony is derived from one cell is lacking. Preirradiation of mice with 450 R significantly increases the number of neutrophilic granulocytopoietic colonies at day 14, provided the chambers are retransplantated to newly irradiated mice at day 7, indicating that the neutrophilic colony forming unit or its progeny is involved as at least one of the targets of the stimulating effect of host irradiation. In contrast, no effect of host irradiation on the numbers of eosinophilic colonies was observed.

Adult↗
PubMed1976

The effect of syngeneic peripheral blood cells on the formation of colonies by normal human bone marrow cells in diffusion chambers in mice.

This paper describes the influence of cells capable of releasing colony stimulating activity (CSA) in vitro on the formation of granulocytic colonies by normal human bone marrow in diffusion chambers in mice. A carbonyl iron method was used to remove phagocytic cells from normal human bone marrow. This treatment prevented spontaneous colony and cluster formation when the cells were cultured in agar in vitro at initial concentrations of 2-5 x 105 cells per ml. However, non-phagocytic bone marrow cells formed granulocytic colonies when inoculated into diffusion chambers at 105 cells per chamber and cultured in 450 R-irradiated or non-irradiated mice. The formation of granulocytic colonies by carbonyl iron treated marrow in diffusion chamber cultures was not consistently enhanced by the admixture of 1.4 x 105 1500 R-irradiated syngeneic light density blood cells (less than 1.077 g/ml) to the chamber inoculum. In contrast, these cells induced cluster or colony formation when added in the same proportion to the marrow cells in agar cultures in vitro. Addition of 1.4 x 105 1500 R-irradiated high density blood cells(greater than 1.077 g/ml) to the inoculum resulted in a slight, non-significant decrease in the number of colonies in diffusion chambers. The stimulating effect of host irradiation on neutrophilic colony formation was independent of the presence of CSA releasing cells in the chamber inoculum.

Animals↗
PubMed1975

Chamber centrifugation: a harvesting technique for estimation of the growth of human haemopoietic cells in diffusion chambers.

A harvesting technique which gives information about the spatial relationships between cells grown in diffusion chambers in mice has been designed. The principle is that cells are centrifuged directly from the chamber clot onto a slide during pronase treatment. The technique has been applied to normal human bone marrow cells grown in diffusion chambers. The slides show that the cells are situated in clusters. A limiting dilution assay of progenitor cells based on the presence of granulopoietic clusters in the chambers demonstrates the use of the method for quantitation of progenitor cells.

Animals↗
PubMed1975

Strontium, lead and nickel incorporation into mouse calvaria in vitro.

Incorporation of strontium, lead and nickel radioisotopes was studied in mouse calvaria in tissue culture. About 90% of the incorporated strontium and 5-12% of the lead were recovered in the mineral phase of the calvaria (hot acid soluble fraction), whereas the nickel was recovered mainly in the organic phase (hot alkali soluble fraction). Metabolic inhibition enhanced the incorporation, which indicated that the mineral metabolism of the calvaria comprised ionic exchange or secondary mineralization phenomenons independent of the activity of bone cells but, possibly, guided by a metabolically active bone membrane.

Animals↗
PubMed1975

Cultivation of leukemic human bone marrow cells in diffusion chambers implanted into normal and irradiated mice.

In order to elucidate the question of whether the maturation defect in vivo in acute leukemia is due to environmental or cellular factors, we have cultured human leukemic cells in a nonleukemic milieu, i.e., diffusion chambers implanted into the abdominal cavity of normal and irradiated mice. For each harvest, the cell count was measured and differential counts and the number of peroxidase-positive cells determined. The cell number decreased with time, without significant difference between culture in irradiated (500 rads) and normal mice. The blast cells succeeded only in developing distorted promyelocytes and myelocytes. There was a general pattern of increase in the number of peroxidase-positive cells. The study supports the concept that acute myeloid leukemia (AML) is a disturbance of cellular maturation due to cellular rather than environmental defects.

Animals↗