Role of nitric oxide (NO) metabolism and inflammatory mediators in childhood obesity.

Objective And Design: The role of NO and adipocytokines in childhood obesity was studied, supposing that obesity provokes inflammation. Children were admitted to the pediatric clinic for a regular check up because of obesity.

Subjects: Obese (n = 79) and healthy (n = 12) children were selected and divided into subgroups according to their age, gender, glucose tolerance and nitric oxide synthase (NOS II) positivity.

Binding specificity of the L-arginine transport systems in mouse macrophages and human cells overexpressing the cationic amino acid transporter hCAT-1.

The uptake of L-arginine into mouse peritoneal macrophages can be inhibited by numerous amino acids and derivatives. Kinetic studies showed an almost entirely competitive inhibition for both cationic and neutral amino acids and derivatives suggesting that the comparison of their binding specificity by using a quantitative structure-activity relationship (QSAR) study is reasonable. The properties of the most efficient inhibitors were the following: the length of the aliphatic side chain, a general structural similarity to L-arginine (>0.

The effect of various inflammatory agents on the phagocytosis and cytokine profile of mouse and rat macrophages.

Objective And Design: The effects of various inflammatory stimuli on the cytokine profile and phagocytic capacity of mouse and rat peritoneal macrophages were investigated in vitro. The correlations between cytokine concentrations and the expressions of NOS II and arginase were also studied.

Methods: Mice and rats were injected intraperitoneally with various inflammatory agents.

The effect of various inflammatory agents on the alternative metabolic pathways of arginine in mouse and rat macrophages.

Objective And Design: The effects of various inflammatory stimuli on the alternative arginine metabolic pathways in mouse and rat peritoneal macrophages were investigated in vitro and compared.

Treatments: Mice and rats were injected i. p.

The cytotoxic anti-tumor effect of MTH-68/H, a live attenuated Newcastle disease virus is mediated by the induction of nitric oxide synthesis in rat peritoneal macrophages in vitro.

Rat peritoneal macrophages were induced to produce high amounts of nitric oxide (NO) when rats were challenged by MTH68/H, (a live attenuated oncolytic Newcastle disease virus strain). The increase in NO production was observed to be viral particle dose dependent. The higher NO production measured could be due to the enhanced expression of NO synthase II enzyme.

Multiple subphases of DNA repair and poly (ADP-ribose) synthesis in Chinese hamster ovary (CHO-K1) cells.

The two types of DNA synthesis as well as poly(ADP-ribose) biosynthesis were measured simultaneously in synchronized intact populations of CHO cells throughout the duration of S phase. Naturally occurring DNA fragmentation was detected by random primed oligonucleotide synthesis (ROPS assay). Fractions of synchronous cell populations were obtained by counterflow centrifugal elutriation.

Subphases of DNA replication in Drosophila cells.

Exponentially growing Drosophila S2 cells in suspension culture were synchronized at low- and high-resolution centrifugal elutriation, and DNA synthesis was measured by [(3)H]-thymidine incorporation throughout the S phase. At low resolution, one repair peak at the G(1)/G(0) border and two replication peaks known as early and late S subphases were observed. At high resolution, six chronologic compartments were distinguished.

Effect of cadmium on the relationship between replicative and repair DNA synthesis in synchronized CHO cells.

Repair and replicative DNA synthesis were measured at different stages of the cell cycle in control and cadmium-treated Chinese hamster ovary (CHO-K1) cells. Cells were synchronized by counterflow centrifugal elutriation. Elutriation resulted in five repair and four replication subphases.

Analysis of 5'-termini of early intermediates of Okazaki fragments accumulated in thymocytes after emetine treatment of mice.

Nascent Hg-DNA synthesized by the incorporation of Hg-dCTP in reversibly permeable cells of murine thymocytes has been characterized earlier. Here we describe the analysis of 5' ends of oligonucleotides isolated from thymocytes 48 hr after a single dose of emetine administration to mice. This small-molecular-weight population of nascent DNA shorter than Okazaki fragments was absent in control cells.

Elevated nascent DNA content of peripheral blood mononuclear cell compartment in lymphoma patients.

The kinetics of DNA synthesis and the DNA pattern of isolated peripheral blood mononuclear cells from control subjects and lymphoma patients prior to drug treatment were studied as a possible tool in the early diagnosis of lymphoma. Thymidine and [H3]-dTTP incorporation represented the measure of replicative DNA synthesis in permeable murine thymocytes and HT-168 human melanoma cells as described earlier. The kinetic parameters of nucleotide incorporation were compared with the ploidity parameters of the Feulgen-stained smears examined by the DNASK TV-cytophotometric system.

Formation of leucyl-leucine-O-methylester in leucine-O-methylester treated cells.

Porcine polymorphonuclear cells (PMN) and murine macrophages (M phi) were treated in vitro with Leu-OMe or Leu-Leu-OMe (1.5-5.0 mM) for various periods of time.

Evidence for the pre-synthesized state of secreted macrophage arginase: arginase activity cannot be modified in short-term cultures.

The arginase produced by peritoneal macrophages is not synthesized de novo in short-term (3 h) cultures after harvesting the cells. In long-term cultures the arginase synthesis is restored. In contrast to arginase lysozyme is continuously synthesized in short-term cultures.

In vitro effect of leucine-O-methylester on polymorphonuclear and mononuclear cells.

The uptake of Leu-OMe and Leu-Leu-OMe was studied in vitro in porcine PMN cells. Both methylesters are metabolized leading to the intracellular accumulation of leucine. Part of the hydrolyzed leucine gradually filtrates back into the culture medium in a time-, temperature- and methylester substrate concentration-dependent manner.

Oncogene expression in thymocytes after emetine treatment of mice.

Emetine (33 mg/kg IP) was used as an immunosuppressive agent to inhibit thymic development. The specific and reversible effect of emetine on the macromolecular biosynthesis of thymocytes provided an in vivo model to investigate cellular differentiation. Cortical cells emigrated upon emetine administration at the early stage of inhibition of macromolecular synthesis, followed by a repopulation stage and differentiation of the thymus.

Inverse relation in the de novo arginase synthesis and nitric oxide production in murine and rat peritoneal macrophages in long-term cultures in vitro.

1. The de novo synthesis of arginase was much higher in murine than in rat peritoneal macrophages. This process was inhibited irreversibly by protein synthesis inhibitors and reversibly by glycolysis blockers.

[The effect of low density lipoprotein (LDL) on NO formation and on arginase activity in mouse peritoneal macrophages].

A large body of the evidence is available to the causative relationship between the elevated blood plasma concentrations of LDL and the atherogenesis. The oxid-LDL (modified LDL) is internalized more rapidly by the macrophages, and there is now substantial evidence that the modified LDL is actually present in atherosclerotic lesions. Recently it has been proved that the endothel cells and monocyta/macrophages generate nitric oxide (NO) from arginine, and that the LDL inhibits the formation of NO in endothel cells.

[The role of endogenous free radicals of nitric oxide (NO)].

The role of endothelium in vasodilatation has only emerged in the last ten years. It was observed that many endogenous substances from endothelial cells triggered the release of a substance which was named endothelium-derived relaxing factor (EDRF). Later has been showed that NO accounted for most if not all of the biological activity of EDRF.

Differences and similarities in the sensitivity of lymphocytic and macrophage plasma membrane to deoxycholate.

Human tonsillar lymphocytes separated on nylon wool and rat macrophages showed different sensitivity to deoxycholate (DOC) treatment at a low (0.24 mM, 0.01%) concentration for 3 h.

Morphological studies on the effect of L-leucine methyl ester on mouse peritoneal macrophages in vitro.

Mouse peritoneal macrophages (MO) were treated in culture with 5 mM L-leucine methyl ester (L-Leu-OMe), for 5, 10, 20, 40, and 60 min. The treatment resulted in rapid vacuolisation of the cytoplasm due to the dilatation and disruption of lysosomes. Autophagy caused by lysosomal enzymes destroyed most of the cytoplasmic organelles by 40 minutes after L-Leu-OMe treatment, but the cell membrane and nucleus were in many MOs resistant to the damage.

Differences in the arginase activity produced by resident and stimulated murine and rat peritoneal macrophages.

1. Murine macrophages showed a considerably higher in vitro arginase production in short time cultures than rat peritoneal cells. 2.

Effect of emetine on the plasma cell population of chicken's gland of Harder.

The emetine effectively abolished the plasma cell population in the chicken's gland of Harder by day 3 of treatment. The plasma cell content regenerated by day 5 following emetine injection, possibly from a metabolically inactive, resting B cell population which was resistant to the emetine treatment. By day 7 extracellular substance in a very large quantity appeared among the plasma cells and epithelial cells which might represent a hyperactive plasma cell secretion.

The effect of L-leucine methyl ester on the phagocytosis and amino acid incorporation of murine peritoneal cells.

Murine peritoneal macrophages were treated in vitro with L-leucine methyl ester (0.25-5.0 mM).

Structural changes in the mouse thymus and lymph node after emetine treatment.

The effect of emetine which is a potent immunosuppresant was studied on the thymus and lymph node. The subcapsular zone of the thymus was depleted and large number of adherent cells accumulated in this thymic region. The medulla enlarged but the cortico-medullary border remained distinct.