The influence of recombinant human erythropoietin on tumor necrosis factor alpha and interleukin-10 production by whole blood cell cultures in hemodialysis patients

Impaired immunological response in hemodialysis (HD) patients, which leads to inappropriate cytokine production, is partially caused by the hyperstimulation of both T lymphocytes and monocytes/macrophages. Recent data suggest that human recombinant erythropoietin (rhEPO) may have an immunological action. The goal of our study was to estimate the influence of rhEPO treatment on the production of the inflammatory cytokine tumor necrosis factor alpha (TNFalpha) and antiinflammatory cytokin interleukin-10 (IL-10) in 10 HD patients receiving rhEPO for 6 months. The levels of cytokines were measured in the in vitro cultures of whole blood. The level of IL-10 increased in all treated patients during the therapy, and it was accompanied by a transitory decrease of TNFalpha. The results of our studies suggest that rhEPO may reduce the inflammatory process by decreasing production of TNFalpha and increasing production of IL-10.

Significance of tumor necrosis factor alpha in patients with long-standing type-I diabetes mellitus

Fifteen out of the forty-five patients with long-standing diabetes mellitus type I were characterised by the presence of TNFalpha in the sera when examined on several occasions over a period of five years. TNFalpha-producing patients had a better control of the disease and a smaller percentage of them suffered from diabetic complications as compared with those not producing this cytokine. TNFalpha-producing patients had lower levels of the proinflammatory markers - IL6 and CRP, and higher concentrations of ACTH and cortisol than those not producing this cytokine. We suggest that TNFalpha released systemically in diabetic patients stimulates the hypophysis-adrenal axis, and in that way indirectly ameliorates autoimmune response occurring during the advanced phase of the disease.

Increase of interleukin 6 and decrease of interleukin 2 production during the ageing process are influenced by the health status

The ageing process is accompanied by the disregulation of interleukin 2 (IL2) and interleukin 6 (IL6) production. In our paper, we asked whether the age between 60 and 70 years is a turning point for the disregulation of both IL2 and IL6 production. Fifty volunteers 60-70 years old, 25 aged 36-59, and 50 of 20-35 years old were enrolled into the study. Their health status was graded according to the criteria of the Senieur Protocol (SP) as 'healthy' and 'almost-healthy'. The cytokines level was determined in the sera of the volunteers. Moreover, the spontaneous release of IL6 by peripheral blood mononuclear cells (PBMC) and the activity of the IL6 gene in non-stimulated PBMC were also analysed. Cytokine levels were measured by biological assays, mRNA for IL6 was detected by RT-PCR method. The results showed that the production of IL2 is not disregulated in the 'healthy' people until the age of 60-70. People not fulfilling all SP criteria are characterised by a lower level of IL2 in the sera. The overproduction of IL6 into the sera and supernatants from non-stimulated PBMC and PBL as well as the activation of IL6 gene start between the ages 36 and 59 and is more pronounced in the 'almost-healthy'.

Suppression of growth of Bomirski Ab melanoma and its metastasis in hamsters by angiogenesis inhibitor TNP-470

The growth of solid tumors and their metastasis is dependent on the development of new blood vessels (angiogenesis). In this study, we examined the effect of the angiogenesis inhibitor TNP-470 on a fast growing melanoma in hamsters. The effect was observed both on tumor growth and metastasis. Treatment with TNP-470 caused a significant decrease in the rate of tumor growth and suppression of the development of metastasis in 63% of treated animals. Some of the hamsters treated with TNP-470 had the tumor excised and the effect of that operation on the development of metastasis was examined. In such cases the inhibitory effect of TNP-470 was weaker than in tumor bearing animals. This indicates that excision of tumor created more favourable conditions for angiogenesis and that the dose of TNP-470 should be increased to be effective in such conditions.

Overactivity of tumor necrosis factor-alpha but not interleukin 6 is associated with low natural killer cytotoxic activity in the elderly

In this paper we asked whether the increased production of two proinflammatory cytokines-tumor necrosis factor-alpha (TNF alpha) and interleukin-6 (IL6) in the absence of the inflammatory stimulus, a phenomenon frequently occurring in the elderly, may contribute to the decrease of natural killer (NK) cytotoxic activity. NK cell activity is a part of a nonspecific immunity directed against infected and transformed cells. We measured the levels of bioactive TNF alpha and IL6 during cytotoxic NK reactions and analyzed the effect of neutralizing monoclonal antibodies anti-TNF alpha and anti-IL6 on the outcome of cytotoxic reaction. Bioactive TNF alpha was produced in higher amounts during cytotoxic reactions of the elderly with low NK activity in comparison with its production by the elderly with high NK activity. Anti-TNF alpha decreased already low cytotoxic responses of the elderly while not having an effect on the cytotoxic potential of high responders. More of the bioactive IL6 was released during cytotoxic reactions of the elderly as compared with young people. There was, however, no relation between the height of NK cytotoxic activity and the amount of IL6. Our results suggest that the increased level of TNF alpha seen in the elderly low NK responders may pose a compensatory mechanism, necessary to keep the highest possible level of NK responses. The increased bioactivity of IL6 during NK reaction of the elderly does not seem to participate in the regulation of the level of NK cytotoxic activity.

Elderly high NK responders are characterized by intensive proliferative response to PHA and Con A and optimal health status

In this paper we verify a hypothesis emerging from recent immunogerontological studies assuming that an elevated level of NK activity in the elderly may be regarded as a factor compensating for a decreased reactivity of T cells. According to this assumption a high NK activity should be associated with a poor reactivity of T cells. In our study the mitogenic responses of lymphocytes of the elderly and the young high and low NK responders to phytohemagglutinin (PHA) and Concanavalin A (Con A) were measured. A high level of NK activity was not found, as would be expected from the hypothesis, to be associated with a poor reactivity to PHA and Con A. In contrast, the mitogenic response to PHA and Con A was intensive in both the young and old high NK responders while weak proliferative responses to T cell mitogens were characteristic of the young and old low NK responders. Thus, our results do not support the assumption of an association between a high NK activity and a low proliferative response to T cell mitogens in the elderly. We also found that both the elderly and the young high NK responders were characterized by an optimal health status.

Monocytes are responsible for depressed natural killer (NK) activity in both young and elderly low NK responders

Two age groups--young (19-35) and elderly (70-91)--were compared with respect to natural killer (NK) cytotoxic activity. In both groups, low and high NK responders could be distinguished. Low NK responders constituted about 70% of all elderly and 40% of young individuals. The differences in the magnitude of NK activity among the young and elderly groups could only be observed when peripheral-blood mononuclear cells but not peripheral-blood lymphocytes were used as effector cells in a 51Cr release assay. Experiments with removal or addition of graded numbers of monocytes showed that these cells were responsible for the low level of NK activity in both the young and elderly low NK responders.

Natural killer sensitivity of tumor cells isolated from primary and metastatic lesions of four Bomirski melanoma variants

Natural killer (NK) sensitivity of melanoma cells isolated from primary and metastatic lesions of four Bomirski melanoma variants was compared. The hamster melanomas differed in their growth rate and metastatic pattern. We found that during tumor growth of all the variants tested, NK sensitivity of melanoma cells at the metastasis formation stage was significantly lower in both primary and metastatic tumors than in cells isolated from primary tumors at transplantation. In the case of Ma, Ab and Ab-455, NK sensitivity of primary tumor cells was higher than that of the cells isolated from metastatic deposits. These data obtained from a spontaneous metastasis tumor model argue for the role of NK cells in preventing metastatic spread of Bomirski melanomas studied.

Modification of mitogenic response to concanavalin A of lymphocytes from old-aged donors by ion channel blockers

Mitogenic response of lymphocytes from young and old donors to Concanavalin A in the absence or presence of Na+ channel blocker--saxitoxin--was compared. Effect of Ca++ channel blockers (Verapamil Diltiazem) on mitogenic response of lymphocytes from old subjects was also examined. It was found that the mitogenic response to Concanavalin A of lymphocytes from donors was significantly lower than that of young ones. In the presence of Saxitoxin the enhancement of the response was noticeable in both groups and the mean responses were similar. However, among the old donors, opposite to the young ones, very high and very poor responders were present. Verapamil and Diltiazem caused significant reduction of mitogenic response to Concanavalin A in the group of old donors. These observations suggest a possible effect of ion channel blockers on immunological functions which would have special significance for old organisms.

Activity of acid phosphatase in target binding cells expressing NK cytotoxic potential

Activity of acid phosphatase was analysed in the NK-effectors from human blood forming conjugates with K 562 cells. Presence of activity of acid phosphatase was associated with the cytolytic potential of the NK-effectors. The non-lytic target-binders did not express activity of this enzyme. The results suggest that activity of acid phosphatase in the effector cells of NK reaction is important in the lethal hit stage.

Effects of air ions on the membrane Na, K-ATPase activity of L 1210 cells

The effect of exposure of L 1210 mouse leukemia cells to artificially generated air ions on the activity of membrane Na, K-ATPase in the cells was investigated. The exposure of cells to air ions of both signs gave identical results, i.e. diminution of transport activity of the enzyme, measured by radioactive 86Rb transport into the cell (ouabain-dependent). Passive ouabain-independent transport of Rb+ into the cells remained unchanged in the air ion-treated cells, as did the passive efflux of the radioisotope from preloaded cells. The possible explanation of the phenomena observed is discussed.

Effect of air ions on L 1210 cells: changes in fluorescence of membrane-bound 1,8-aniline-naphthalene-sulfonate (ANS) after in vitro exposure of cells to air ions

The ability of air ions to produce changes in the electrical properties of L 1210 mouse leukemia cells was tested. The fluorescence of ANS incorporated into a membrane lipid bilayer (measured microphotometrically) was used as a probe. It was shown that the action of air ions of both signs could change (negative ions by increasing and the positive ones by decreasing) the fluorescence intensity of ANS in the cell surface structures or to an imbalance of ions inside and outside the cell. Both possibilities are discussed in the light of the results of experiments using ouabain or biguanide as factors diminishing the intensity of ANS fluorescence.

Effect of air ions on healing of wounds of rat skin

Rat skin was deprived of epidermis and the wound was exposed to ions generated with Bion 80 apparatus, for 3 h, just after wounding, only once. In comparison with the control, positive air ions retarded and negative air ions accelerated the wound healing. This effect was almost the same when air, nitrogen, oxygen and carbon dioxide were applied. A direct action of air ions is suggested.

Age-dependent decline of natural killer and antibody-dependent cell mediated cytotoxicity activity of human lymphocytes is connected with decrease of their acid phosphatase activity

Decline of cytotoxic potential of lymphocytes of aged persons in ADCC and NK cell mediated cytotoxic reaction was paralleled by a drop in the activity of acid phosphatase. Intensity of ADCC reaction and the level of acid phosphatase activity showed statistically significant correlation when these two parameters were measured in peripheral blood of the same persons. The role of acid phosphatase in cytotoxic function of lymphocytes is discussed.

Activity of acid phosphatase in resting and mitogen-stimulated human peripheral blood lymphocytes

Activity of acid phosphatase was found to be higher in T than in non-T cells of human peripheral blood lymphocytes. The T cell mitogen PHA induced an increase in the magnitude of acid phosphatase activity, while the B cell mitogen LPS was not able to produce any effect on acid phosphatase activity. Acid phosphatase activity in lymphocytes correlated with their spontaneous proliferative activity.

Increase of size and dry mass of mouse erythrocytes depending on age of donors

It was found that during aging of mice the size and the dry mass of their erythrocytes increased. Similarity of this phenomenon to that observed during aging in vitro and in vivo is suggested.

Age-related changes of activity of acid phosphatase in PHA-stimulated lymphocytes

Peripheral blood lymphocytes of 70-year-old individuals as well as spleen cells of 18-month-old Balb/c mice were characterized by diminished activity of acid phosphatase in relation to the activity of that enzyme in cells from young subjects. Simultaneously performed histochemical tests revealed that aging process in both species examined was accompanied by a reduction of the number of cells, disclosing the activity of acid phosphatase. Age-related differences with regard to the level of acid phosphatase became more pronounced after stimulation of cells with PHA. The decrease of acid phosphatase activity during aging is discussed in relation to the function of lymphocytes.

Urea synthesis in hepatocytes isolated from young and old rats

Effects of glucagon and epinephrine stimulation on urea synthesis from lactate, pyruvate, NH4Cl, and ornithine in isolated rat hepatocytes from young and old rats were compared. It was found that the production of urea from those substrates was almost the same in both age groups. The concentrations of hormones that caused the maximum effect were the same for both groups of rats. The effectiveness of the stimulation of urea synthesis by glucagon and epinephrine was the same in hepatocytes isolated from young and old rats.

Dielectric properties of murine lymphocytes

Dielectric measurements in frequency range from 0.032 up to 110 MHZ were performed on the suspension of lymphocytes isolated from the spleen of Balb/c mouse. Basing on measurements of electric capacitance (C) and electric conductance (G) of lymphocyte suspension and on the simplified Pauly-Schwan equations the following electrical parameters of lymphocytes were calculated: relative electrical permittivity of the intracellular substance (epsilon i = 136) electrical conductivity of the inner phase (intracellular substance) (kappa i = 8.94 mS/cm), specific capacitance of cell membrane (CM = 0.82 microF/cm2). Relative electrical permittivity of the membrane (epsilon s = 4.6) has also been calculated. Two of those quantities (epsilon i = and kappa i) additionally determined by means of empirical dependences. The value of epsilon i and kappa i were respectively 125 and 8.79 mS/cm. All those measurements were taken at temperature amounting to 293 K.

Age-dependent changes of hormone-stimulated gluconeogenesis in isolated rat hepatocytes

Effects of glucagon or catecholamine stimulation on glucose synthesis from lactate/pyruvate, alanine, fructose or glycerol in isolated hepatocytes from young and old rats were compared. It was found that production of glucose by non-stimulated hepatocytes was almost the same in hepatocytes both from young and old rats. The concentrations of hormones which caused the maximal effect were the same for both compared groups of rats. However, the effect of stimulation by glucagon was significantly greater in hepatocytes of young rats than of old ones, when lactate/pyruvate or alanine were used as substrates, while no such difference was observed when fructose or glycerol were used. Epinephrine and norepinephrine stimulated glucose synthesis from all substrates investigated to the same extent in hepatocytes isolated from both compared groups of rats. The biochemical and physiological aspects of these findings are discussed.

The ANAE reaction pattern of reticular stromal cells of lymphatic organs from normal and hydrocortisone--treated mice

The pattern of alpha-naphthyl-acetate esterase (ANAE) activity in stromal and lymphatic cells has been examined in lymphatic organs from normal and hydrocortisone (HC)-treated mice. The distribution of ANAE-positive lymphocytes as well as stromal cells in peripheral lymphatic organs was different in T- and B-dependent regions, while in the thymus there was the difference between cortex and medulla. The HC application evoked a marked changes in the pattern of ANAE-positive cells distribution of the thymus, producing only a slight ones in the remaining organs. The influence of HC on the ANAE reaction intensity and distribution in the examined tissue sections is discussed.