No abstract

It is considered that a decrease of the ratio of polychromatic erythrocytes (PCE) to normochromatic erythrocytes (NCE) (P/N) in the micronucleus test is an indicator of bone marrow toxicity induced by mutagens. However, the exact meaning of fluctuation in the P/N ratio is not yet known. We have studied this point by counting the total number of erythrocytes and nucleated cells in the bone marrow following various treatments. The P/N ratio decreased gradually with time after administration of mitomycin C. Our data suggest that the decrease of P/N ratio was attributable to an increase in the numbers of the denominator, i.e. NCE, caused by rapid differentiation and multiplication or denucleation of erythroblasts which remained in the bone marrow instead of entering the peripheral blood stream. A decrease of P/N ratio was also observed in the early phase after administration of erythropoietin, an agent which induces differentiation and multiplication of erythroblasts. This phenomenon might result from an increase of PCE delivery into the blood circulation. However, following the initial decrease, the P/N ratio increased gradually 48 h after administration of erythropoietin. It is supposed that this increase probably resulted from an increase in PCE in the bone marrow due to the direct effects of erythropoietin on erythropoiesis. The drastic change in erythropoiesis in the bone marrow induced by either mutagen or erythropoietin treatment will affect the fluctuations of the P/N ratio or the number of micronucleated erythrocytes per non-micronucleated erythocytes in the micronucleus test. This contrasts with the original explanation for such fluctuations which attributed them to replenishment of the marrow by peripheral blood.

Significant improvement by intervention was shown in multiple domains including cognitive function and BPSD. Cognitive decline and worsening of BPSD are predictors of care burden and hospitalization, thus intensive rehabilitation for dementia was beneficial for both individuals with dementia and their caregivers.

No abstract

The formation of negative hydrogen ions is investigated in a pure hydrogen RF plasma using a grid-method for electron temperature control. Using the grid method we produce both high and low electron temperature plasmas in the separated regions in the chamber, in which the electron temperature in the downstream region is controlled by the grid potential. The production rate of negative ions depends strongly on the grid potential. We observe efficient negative hydrogen ion production in the downstream region when the grid is negatively biased in the hydrogen pressure range of 2–5 mTorr.