Phagocytosis activity of monocytes and macrophages in patients with plasmacytoma

The capacity to phagocytosis in monocytic macrophages was investigated in 24 patients with plasmocytoma. The investigation of this capacity was made by using short-term cultures with sheep erythrocytes loaded with antibodies and complement. In comparison to the control group the percentage of phagocyting macrophages was lowered in 16 from 24 patients. This impairment of the function of monocytic macrophages seems to be bound neither to the type of plasmocytoma nor to the stage of disease. Among other things, the nature of cell defect is discussed. The necessity of further investigations is emphasized.     

Microbial characteristics of sandy soils exposed to diazinon under laboratory conditions

Changes in microbiological characteristics in response to diazinon, applied at three different dosages of 7, 35 and 700 mg kg^?1 soil, were studied in pots filled with sandy soils of different texture. The insecticide dosages corresponded to the maximum predicted environmental concentration (PEC) in field conditions and five or hundred times this rate, respectively. To ascertain these changes, activities of selected soil enzymes, numbers of some microbial populations and bacterial community structure (r/K-strategists) were determined. Acid phosphatase activity and concentrations of ammonium ions either increased or were unaffected by the diazinon dosages. In contrast, nitrate ions, alkaline phosphatase, urease and especially dehydrogenase activities decreased in both soils treated with the higher dosages of the insecticide. The diazinon treatments increased the numbers of culturable bacteria and fungi; however, N-fixing bacteria and nitrifiers (but not denitrifiers) were decreased in both soils. When the high concentration of diazinon (100-times PEC) was added to the loamy sand soil (LS), simulating an undiluted chemical spill, the bacterial community structure shifted towards domination of K-strategists over time. However, r-strategists dominated in the community exposed to the same dosage of the insecticide in the sandy loam soil (SL). Generally, SL soil characteristics were more suitable for microbial activity and growth than those of LS soil were. The results indicate that except a situation of undiluted spill diazinon seems to be a non-hazardous chemical for the culturable soil microorganisms when applied at recommended concentrations.     

Sensitivity of insect ovarian tissues to various pteridines as tested in tissue culture

The effect of pteridine derivatives and analogues on the cell outgrowth from the ovarian explants of the waxmoth, Galleria mellonella, was examined in hanging-drop cultures and cytochemical tests were made for succinate and glucose-6-phosphate dehydrogenases. Most of the derivatives and analogues of 2-amino-4-hydroxypteridine injured to a lesser or greater extent insect ovarian tissues in vitro, depending on the drug structure and the concentration applied. Of all the pteridine derivatives and analogues tested only 2-amino-4-mercaptopteridine and its C-6,7-dimethyl derivative (10 μM) promoted cell outgrowth from the explants as did folate.     

Multiple forms of acid phosphatase in rat liver parenchymal,endothelial, and kupffer cells

Purified suspensions of highly viable parenchymal, endothelial, and Kupffer cells were prepared from rat liver. In the liver cell classes, total activities of acid phosphatase were determined with 4-methylumbelliferylphosphate, 1-naphthylphosphate, and p-nitrophenylphosphate. The specific enzyme activities were different for each type of cell and, even within one cell class, the enzymes showed different conversion rates for the three substrates. These results indicate the presence of multiple forms of acid phosphatase enzymes in each cell class. The inhibiting effects of tartrate, fluoride, and alloxan on the acid phosphatase activities were investigated. Depending on the substrate used, the inhibitors inactivated the enzymes at different rates, which also indicates the presence of multiple forms of acid phosphatase enzymes in the liver cell classes. By means of an isoelectric focusing technique, acid phosphatase enzymes could be separated on the basis of their differences in isoelectric points. One form with an isoelectric point around 4 is found in Kupffer cells, whereas another form with an isoelectric point of about 7 is found in parenchymal cells. Endothelial cells possess both forms. These findings suggest a specificity in the function of this lysosomal enzyme in each cell class.     

Effect of adrenalin, insulin and contractions on the content of the free fatty acid fraction in skeletal muscle.

The fraction of free fatty acids (FFA) is present in skeletal muscles. However, there is almost no data regarding regulation in the content of this intramuscular lipid pool. We took advantage of the isolated muscle preparation to examine whether: a) increasing exogenous concentration of FFA (500microM or 700microM, 30min) b) insulin (10.00 I.U./L, 30min), c) adrenalin (4.4 nM, 30 min), or d) contractions (200ms, tetani, 1Hz, 30min), affect the FFA content inside myocytes. Incubation of soleus (S) and extensor digitorum longus (EDL) with increasing concentrations of exogenous FFA (from 500microM to 700microM) resulted in an increase in the total FFA fraction in both muscles studied (by 280.2% and 259.1%, respectively). In contracting muscles FFA pool was significantly reduced both in S (by 73.1%) and in EDL (by 31.1%). Neither stimulation by adrenalin nor insulin affected the total content of FFA fraction in the muscles examined. We conclude that a) increased availability of exogenous FFA at the sarcolemma level results in an increase in the size of intramuscular FFA fraction b) the intracellular FFA fraction is utilized by contracting muscles with regard to the fiber composition and to a greater extent in more oxidative muscles, c) FFA fraction remains stable upon stimulation by insulin or adrenalin.