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Abstract The concept of the symplectic covariance property of the Wigner distribution function and the symplectic invariance of the Wigner–Rényi entropies has been leveraged to estimate the interaction time of the moving quantum state in the presence of an absolutely integrable time-dependent potential. For this study, the considered scattering centre is represented initially by the Gaussian barrier. Two modifications of this potential energy are considered: a sudden change from barrier to barrier and from barrier to well. The scattering state is prepared in the form of a Schrödinger cat, and the Moyal equation governs its further time evolution. The whole analysis of the considered scattering problem is conducted in the above-barrier regime using the phase-space representation of quantum theory. The presented concept shifts the focus from the dynamics of the quantum state to a symplectically invariant state functions in the form of the Wigner–Rényi entropies of order one and one-half. These quantities serve as indicators of the beginning and end of the interaction of the non-Gaussian state with the sufficiently fast decaying potential representing the scattering centre. The presented approach is significant because it provides a new way to estimate the interaction time of moving quantum states with the dynamical scattering centre. Moreover, it allows for studying scattering processes in various physical systems, including atoms, molecules, and condensed matter systems.

Abstract The phase-space approach based on the Wigner distribution function is used to study the quantum dynamics of the three families of the Schrödinger cat states identified as the even, odd, and Yurke–Stoler states. The considered states are formed by the superposition of two Gaussian wave packets localized on opposite sides of a smooth barrier in a dispersive medium and moving towards each other. The process generated by this dynamics is analyzed regarding the influence of the barrier parameters on the nonclassical properties of these states in the phase space below and above the barrier regime. The performed analysis employs entropic measure resulting from the Wigner–Rényi entropy for the fixed Rényi index. The universal relation of this entropy for the Rényi index equal one half with the nonclassicality parameter understood as a measure of the negative part of the Wigner distribution function is proved. This relation is confirmed in the series of numerical simulations for the considered states. Furthermore, the obtained results allowed the determination of the lower bound of the Wigner–Rényi entropy for the Rényi index greater than or equal to one half.

The article reports on the findings from the metallographic analysis of 13th c. archaeological objects from Chełm (eastern Poland). The group submitted for analysis includes jeweller’s dies used in the production of women’s ceremonial ornaments, crucibles and bronze ornaments. The Mongol invasion of 13th c. had caused craftsmen from central areas of East Europe to flee and seek shelter in the western parts of Rus. It may be safe to interpret the finds from Chełm as the remains of a jeweller’s workshop, the site of casting and working copper alloys and silver. The analysis of the technology used in casting copper alloys and silver in the jeweller’s workshop were made using optical microscopy, X-ray spectroscopy and X-ray radiography.

Objective: This study addressed the role of the pattern recognition receptors (PRR), which recognize different molecular structures present on microorganisms, apoptotic, senescent and tumor cells, in the stimulation of human monocyte and monocyte-derived macrophages (MDM) for the production of intracellular cytokines. Materials and methods: Monocytes and MDM were stimulated with different ligands of scavenger receptors (SR) and mannose receptor (MR). Production of intracellular cytokines: tumor necrosis factor alpha (TNFa), interleukin 10 and 12 (IL-10, IL-12) was determined by flow cytometry following staining with anti-cytokine monoclonal antibodies (mAbs). Results: The ligands of SR type A: fucoidan, polyguanylic acid (polyG), chemically modified low density lipoproteins (LDL), ligands of SR-B: native and chemically modified LDL, and ligand of mannose receptor (MR) – mannan induced strong expression of intracellular TNFa and weaker IL-10 in monocytes, while phosphatidylserine (PdS) was without effect. IL-12 was stimulated only by fucoidan and polyG. The induction of cytokine m-RNA generally followed the pattern and the magnitude of intracellular cytokine production. In MDM, intracellular TNFa and IL-12 expression was induced by mannan, native and modified LDL, but not other ligands. Expression of IL-10 was less pronounced and occurred following stimulation with fucoidan, polyG and modified, but not native, LDL. Conclusions: These results suggest that some PRR ligands may be involved in activation of monocytes/MDM for the production of mainly proinflammatory cytokines (TNFa, IL-12) implicating their role in the response to microbial and tumor invasion. [ABSTRACT FROM AUTHOR]

Spin-dependent electron transport has been studied in magnetic semiconductor waveguides (nanowires) in the helical magnetic field. We have shown that—apart from the well-known conductance dip located at the magnetic field equal to the helical-field amplitude Bh—the additional conductance dips (with zero conductance) appear at a magnetic field different from Bh. This effect occurring in the non-adiabatic regime is explained as resulting from the resonant Landau–Zener transitions between the spin-split subbands. [ABSTRACT FROM AUTHOR]

Possibility of reaching a consensus in social systems with strong initial fragmentation is one of the most interesting issues in sociophysics. It is also intriguing what the dynamics of such processes is. To address those problems, we performed computer simulations using well-established models of social opinion formation, namely, the voter, Sznajd, and Latané models. We investigated opinion dynamics in cases where the initial number of opinions is very large, equal to the number of actors (the voter and Latané models) or when every second actor has their own opinion (Sznajd model), with some variations on the update schemes, lattice topologies, effective ranges of interaction, and information noise levels. For all considered models, the number of opinions assumed by the actors is finally almost always reduced to only one. However, while the voter and Latané models exhibit a power-law time decrease in the number of opinions, the Sznajd model follows a complex three-stage behavior. We also demonstrated the mean/median time of reaching the consensus scales with system size according to a power law for voter and Sznajd models, while for the Latané model, this increase is even faster. Our results show that in the studied models, the consensus is possible, provided that a long enough and model-dependent time to reach this state is available., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)

The polarization of opinions and difficulties in reaching a consensus are central problems of many modern societies. Understanding the dynamics governing those processes is, therefore, one of the main aims of sociophysics. In this work, the Sznajd model of opinion dynamics is investigated with Monte Carlo simulations performed on four different regular lattices: triangular, honeycomb, and square with von Neumann or Moore neighborhood. The main objective is to discuss the interplay of the probability of convincing (conformity) and mass media (external) influence and to provide the details of the possible phase transitions. The results indicate that, while stronger bonds and openness to discussion and argumentation may help in reaching a consensus, external influence becomes destructive at different levels depending on the lattice.

The dynamics of social relations and the possibility of reaching the state of structural balance (Heider balance) under the influence of the temperature modeling the social noise level are discussed for interacting actors occupying nodes of classical random graphs. Depending on the graph density D, either a smooth crossover or a first-order phase transition from a balanced to an imbalanced state of the system is observed with an increase in the thermal noise level. The minimal graph density Dmin for which the first-order phase transition can be observed decreases with the system size N as Dmin∝N-0.58(1). For graph densities D>Dmin, the reduced critical temperature Tc⋆=Tc/Tc(D=1) increases with the graph density as Tc⋆∝D1.719(6) independently of the system size N., (© 2023 Author(s). Published under an exclusive license by AIP Publishing.)

The dynamics of social relations and the possibility of reaching the state of structural balance (Heider balance) are discussed for various networks of interacting actors under the influence of the temperature modeling the social noise level. For that purpose, two main types of lattices are considered. The first is created by removing some links from a regular triangular lattice to produce a diluted triangular lattice, and the second by adding more links to create an enhanced triangular lattice. In both those cases, the full range of possible graph densities is discussed, limited by the extreme cases of networks which consist of a small number of separated triads and fully connected networks. It is shown that the existence of the balanced state is not possible if the average node degree is too close to the value characterizing the regular triangular lattice. Otherwise, both balanced (or partially balanced) and imbalanced states are possible, depending on the temperature. However, only for graphs which are dense enough a phase transition of the first kind is observed, while less enhanced networks (and all diluted) indicate a smooth crossover between the two states. The crossover temperatures are size independent only for the diluted triangular lattices and depend on the size of the system for the enhanced triangular lattices, as is the case also for the critical temperatures of the phase transition observed in denser enhanced lattices.

The coherent superposition of two well separated Gaussian wavepackets, with defects caused by their imperfect preparation, is considered within the phase-space approach based on the Wigner distribution function. This generic state is called the defective Schrödinger cat state due to this imperfection which significantly modifies the interference term. Propagation of this state in the phase space is described by the Moyal equation which is solved for the case of a dispersive medium with a Gaussian barrier in the above-barrier reflection regime. Formally, this regime constitutes conditions for backscattering diffraction phenomena. Dynamical quantumness and the degree of localization in the phase space of the considered state as a function of its imperfection are the subject of the performed analysis. The obtained results allow concluding that backscattering communication based on the defective Schrödinger cat states appears to be feasible with existing experimental capabilities.

We perform simulations of structural balance evolution on a triangular lattice using the heat-bath algorithm. In contrast to similar approaches-but applied to the analysis of complete graphs-the triangular lattice topology successfully prevents the occurrence of even partial Heider balance. Starting with the state of Heider's paradise, it is just a matter of time when the evolution of the system leads to an unbalanced and disordered state. The time of the system relaxation does not depend on the system size. The lack of any signs of a balanced state was not observed in earlier investigated systems dealing with the structural balance.

We consider the dynamics of interpersonal relations which leads to balanced states in a fully connected network. Here this approach is applied to directed networks with asymmetric relations, and it is generalized to include self-evaluation of actors, according to the 'looking-glass self' theory. A new index of self-acceptance is proposed: the relation of an actor to him/herself is positive, if the majority of his/her positive relations to others are reciprocated. Sets of stable configurations of relations are obtained under the dynamics, where the self-evaluation of some actors is negative. Within each set all configurations have the same structure.

In the early Middle Ages, the region of the Cherven Towns, which is now located on both sides of the Polish-Ukrainian border, was fiercely contested by Slavs in the process of forming their early states. The main objective of the present study was to investigate the homogeneity of an early medieval population uncovered in that region, in the town of Gródek on the Bug River, by screening for non-local individuals. The origin of the studied skeletons was ascertained using analysis of oxygen isotopes in the phosphates isolated from bone tissue. In this paper, the isotope ratios obtained for samples collected from 62 human skeletons were compared to the background δ(18)O (in precipitation water) from the regions of Kraków (south-eastern Poland), Lviv (western Ukraine), Brest (western Belarus), and Gródek, as well as to the ratios determined for the animals coexisting with the studied population. Proportions of oxygen isotopes obtained for all the studied individuals were found to be similar to those for the precipitation water and animals, which indicates the absence of bone fragments of individuals originating in other regions., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Magnetotransport properties of a semiconductor nanowire with a constriction have been studied within the Landauer-Büttiker formalism in the presence of the axially oriented magnetic field at low temperatures. The one-electron quantum states in the nanowire have been calculated within the adiabatic approximation which takes into account the three-dimensional structure of the nanowire and allows us to study the effect of the transverse quantum states on the electronic current. The calculated current-voltage characteristics exhibit well pronounced peaks that result from the enhancement of the electron transmission by the Stark resonant states formed in the triangular quantum well near the constriction. The effect of the Stark resonances is clearly manifested in the magnetoresistance as a function of the drain-source voltage. The calculated magnetoresistance exhibits two interesting features: (i) rapid jumps at certain voltages, caused by the enhancement of the electron transmission by the Stark resonances, (ii) changes of sign that stem from the magnetic-field induced changes of the current-voltage characteristics slope. The influence of the constriction parameters (radius, length, smoothness of the potential barrier, position of the constriction in the nanowire) on the electronic current has also been analyzed. Since the effective potential barrier created by the constriction in the nanowire is similar to that generated by the negatively charged gate surrounding the nanowire, the presented results can also be applied to the description of the magnetoresistance in the gated nanowires.

Background: There is certain experimental and clinical evidence indicating that the covering of bare metal stents (BMS) with drug eluting polymers to produce drug eluting stents (DES) results in increased stent stiffness and modifies the mechanical properties of the stent platform. In addition, it has been speculated that the mechanical performance of DES, compared to BMS, may be related to the type of polymer used to cover stents., Aim: We aimed at evaluating the deliverability of DES with a lactate based biodegradable polymer and BMS in patients with stable coronary artery disease in a prospective randomised study., Methods: One hundred eleven consecutive patients (age: 36-77, mean 58.8 years) scheduled for routine angioplasty due to stable coronary disease were randomised to receive BMS (Chopin II(TM), Balton, Poland) or paclitaxel eluting stent (Chopin Luc(TM), Balton, Poland) using the same metal platform. Only patients scheduled for angioplasty using the direct implantation technique of a single stent were randomised. The exclusion criteria included patients 〉 80 years, multivessel disease and reference diameter of the target vessel 〉 3.5 mm., Results: In the BMS group (n = 55; 35 males and 20 females), the mean diameter of implanted stents was 3.09 ± 0.40 and the mean length was 11.37 ± 2.80, whereas in the DES group (n = 56; 34 males and 22 females) the mean stent sizes were 3.02 ± 0.34 and 17.90 ± 7.38 mm, respectively (p 〉 0.05 for length). The groups did not significantly differ regarding the frequency of stent implantation to particular coronary vessels. The direct stenting technique was attempted and failed, leading to the stents' implantation after predilatation in five patients in the BMS group and six patients in the DES group. Failure of stent implantation and subsequent implantation of another stent type was observed in no BMS patients and in one DES patient (NS)., Conclusions: Although stent covering with lactate based drug eluting polymer may increase its stiffness, it does not affect its deliverability in patients with stable coronary disease.

Background: Functional mitral regurgitation (MR) due to dilated cardiomyopathy or coronary artery disease remains a significant clinical problem. These clinical entities lead to left ventricular enlargement, which results in annular dilation and MR. Surgical valvuloplasty is associated with a high perioperative risk. This is the reason why percutaneous techniques for mitral valve repair are under development. One of the most advanced devices for mitral annuloplasty is the Carillon™ system., Aim: Functional assessment of patients who have undergone mitral annuloplasty using the Carillon™ device., Methods: Fourteen consecutive patients with functional MR who had undergone successful implantation of the Carillon™ device were enrolled. The device was implanted into the venous system of the heart and applied tension to the mitral annulus in order to improve coaptation of the cusps and reduce MR. In implanted patients echocardiographic MR parameters (vena contracta, effective regurgitant orifice area) were assessed before, immediately after the procedure and during 1-month follow-up. Furthermore, the 6-minute walk test (6MWT), Naughton stress test and the NYHA functional class assessment were performed before the procedure and at 1 month. Quality of life was evaluated by the Kansas City Cardiomyopathy Questionnaire. One month after the procedure patients were also asked to compare their health status with their baseline condition., Results: In implanted patients improvement of echocardiographic MR parameters was observed, both immediately after the procedure and during 1 month follow-up. These parameters included vena contracta (0.36 ± 0.03 and 0.31 ± 0.03 vs 0.65 ± ± 0.04 cm, both p < 0.001) as well as effective regurgitant orifice area (0.18 ± 0.02 and 0.20 ± 0.02 vs 0.28 ± 0.04 cm², p < 0.05 and p < 0.005, respectively). One month after the procedure the 6MWT (390 ± 26.25 vs 311.9 ± 15.71 m, p < 0.001), Naughton treadmill exercise test (5.06 ± 0.47 vs 3.49 ± 0.27 min, p < 0.005) and NYHA classification (1.93 ± ± 0.20 vs 2.93 ± 0.07, p < 0.005) were significantly improved. Quality of life improved from 67.93 ± 3.30 at baseline to 88.31 ± 4.02 at 1 month (p < 0.001). All the patients reported some degree of improvement at 1 month compared to baseline., Conclusions: Implantation of the Carillon™ device in patients with functional MR leads to increased exercise capacity and improvement of selected echocardiographic MR parameters. Randomised trials are needed to assess the clinical value of the technique. Kardiol Pol 2011; 69, 3: 228-233.

Background: Dilated cardiomyopathy is characterised by significant enlargement of cardiac chambers, which can lead to functional mitral regurgitation. Surgery is a widely accepted treatment of secondary mitral regurgitation. Conventional cardiac surgery has a high procedural risk and therefore new techniques for percutaneous repair of mitral valve are being developed. The CARILLON system is one of devices that is implanted into the coronary venous system, which enables tension of the mitral ring in order to improve coaptation of the leaflets., Aim: Echocardiographic analysis of the CARILLON system implantation efficacy evaluated directly and one month after implantation., Methods: The study in included 9 patients, aged 58.56 +/- 6 years, with severe functional mitral regurgitation, who fulfilled the following echocardiographic criteria: large central jet ł 4 cm(2) or ł 20% of the left atrium area or wall-impinging eccentric jet reaching the pulmonary veins, vena contracta (VC) ł 0.30 cm, effective regurgitant orifice area (ERO) ł 0.2 cm(2), regurgitant volume (RV) ł 30 ml or regurgitant fraction (RF) > 30%. Exclusion criteria were: concomitant severe tricuspid valve insufficiency, significant organic mitral valve pathology, chronic atrial fibrillation, foreign body in the coronary sinus, or thrombus in the left atrial appendage. The prerequsite for implanting the device was a significant reduction in the mitral regurgitation jet observed by transesophageal echo-cadiography (TEE), seen during the procedure. After one month, a transthoracic echocardiography (TTE) was performed to evaluate mitral regurgitation by analysing the same parameters assessed before implanting CARILLON to the coronary sinus., Results: A significant improvement of VC after the procedure, in comparison to the value before the procedure (0.43 +/- 0.12 vs. 0.66 +/- 0.14 cm, p < 0.05), was observed. This improvement was lower one month after the implantation of the device (0.35 +/- 0.1 cm, p < 0.005). The ratio of the jet area to the left atrial area was reduced from 54.96 +/- 11.18% to 38.57 +/- 9.79% (p < 0.005) and sustained after a month at 36.33 +/- 10.15% (p < 0.005). Other echocardiographic parameters of evaluation of mitral regurgitation tended to improve, however the differences did not reach statistical significance. The ERO in subsequent studies was: 0.25 +/- 0.09 cm(2), 0.23 +/- 0.07 cm(2), and 0.24 +/- 0.07 cm(2), and RV decreased from 33.06 +/- 11.81 ml before the procedure, to 32.33 +/- 7.84 ml one month after the procedure., Conclusions: The CARILLON system implantation to the coronary venous system in patients with secondary mitral regurgitation can lead to the improvement of selected echocardiographic indices of mitral regurgitation.

Mitral regurgitation may result from left ventricular dilatation and cause progression of heart failure. Percutaneous techniques for mitral valve repair are under development. Techniques utilizing a trans-coronary venous approach exploit the anatomical relationship between the mitral annulus and the venous system of the heart. The coronary sinus, great cardiac vein and the origin of the anterior interventricular vein surround the posterior mitral annulus. This enables percutaneous approaches to annuloplasty for mitral regurgitation. Devices can be implanted into the coronary veins that modify the shape and size of the mitral annulus. We present a case of ischaemic mitral regurgitation successfully treated by use of a percutaneous approach, the Carillon Mitral Contour System. Significant reduction of the mitral regurgitation jet was observed. The patient was discharged 4 days after the procedure. During the follow-up visits, the patient showed an improved general condition and increased exercise capacity. Procedural steps are shown in detail and the current status of the coronary sinus based technique is discussed. Percutaneous techniques for mitral valve repair may be an attractive alternative to cardiac surgery in heart failure patients with secondary mitral regurgitation. The Carillon Mitral Contour System is under ongoing clinical evaluation in the AMADEUS trial.

Objective: This study addressed the role of the pattern recognition receptors (PRR), which recognize different molecular structures present on microorganisms, apoptotic, senescent and tumor cells, in the stimulation of human monocyte and monocyte-derived macrophages (MDM) for the production of intracellular cytokines., Materials and Methods: Monocytes and MDM were stimulated with different ligands of scavenger receptors (SR) and mannose receptor (MR). Production of intracellular cytokines: tumor necrosis factor alpha (TNF alpha), interleukin 10 and 12 (IL-10, IL-12) was determined by flow cytometry following staining with anti-cytokine monoclonal antibodies (mAbs)., Results: The ligands of SR type A: fucoidan, polyguanylic acid (polyG), chemically modified low density lipoproteins (LDL), ligands of SR-B: native and chemically modified LDL, and ligand of mannose receptor (MR)-mannan induced strong expression of intracellular TNF alpha and weaker IL-10 in monocytes, while phosphatidylserine (PdS) was without effect. IL-12 was stimulated only by fucoidan and polyG. The induction of cytokine m-RNA generally followed the pattern and the magnitude of intracellular cytokine production. In MDM, intracellular TNF alpha and IL-12 expression was induced by mannan, native and modified LDL, but not other ligands. Expression of IL-10 was less pronounced and occurred following stimulation with fucoidan, polyG and modified, but not native, LDL., Conclusions: These results suggest that some PRR ligands may be involved in activation of monocytes/MDM for the production of mainly proinflammatory cytokines (TNF alpha, IL-12) implicating their role in the response to microbial and tumor invasion.

Although blood monocytes exhibit significant cytotoxic activity against tumor cells, the function of tumor infiltrating macrophages (TIM) is depressed in cancer patients. This study addresses the question of how the antitumor response of human monocytes, assessed by production of cytokines (tumor necrosis factor alpha, TNF; IL-10; IL-12p40) and cytotoxicity, is altered by exposure to cancer cells. Tumor cell--pre-exposed monocytes restimulated with tumor cells showed significantly decreased production of TNF, IL-12, increased IL-10 (mRNA and release) and inhibition of IL-1 receptor-associated kinase-1 (IRAK-1) expression. This down-regulation of cytokine production was selective, as the response of pre-exposed monocytes to lipopolysaccharide (LPS) was unaffected. Treatment of tumor cell--pre-exposed monocytes with hyaluronidase (HAase) improved their depressed production of TNF, while HAase-treated cancer cells did not cause monocyte dysfunction. The response of hyaluronan (HA)--pre-exposed monocytes to stimulation with tumor cells was also inhibited. Cytotoxic activity of monocytes pretreated with cancer cells was also decreased. This study shows that tumor cells selectively deactivate monocytes and suggests that tumor cell-derived HA by blocking CD44 on monocytes inhibits their antitumor response. These observations may provide some explanation for the depressed function of TIM in human malignancy.

The present study examined the ability of human monocytes to produce reactive oxygen intermediates after a contact with tumour cells. Monocytes generated oxygen radicals, as measured by luminol-enhanced chemiluminescence and superoxide anion production, after stimulation with the tumour, but not with untransformed, cells. The use of specific oxygen radical scavengers and inhibitors, superoxide dismutase, catalase, dimethyl sulphoxide and deferoxamine as well as the myeloperoxidase inhibitor 4-aminobenzoic acid hydrazide, indicated that chemiluminescence was dependent on the production of superoxide anion and hydroxyl radical and the presence of myeloperoxidase. The tumour cell-induced chemiluminescent response of monocytes showed different kinetics from that seen after activation of monocytes with phorbol ester. These results indicate that human monocytes can be directly stimulated by tumour cells for reactive oxygen intermediate production. Spontaneous monocyte-mediated cytotoxicity towards cancer cells was inhibited by superoxide dismutase, catalase, deferoxamine and hydrazide, implicating the role of superoxide anion, hydrogen peroxide, hydroxyl radical and hypohalite. We wish to suggest that so-called 'spontaneous' tumoricidal capacity of freshly isolated human monocytes may in fact be an inducible event associated with generation of reactive oxygen intermediates and perhaps other toxic mediators, resulting from a contact of monocytes with tumour cells.

The tumour necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) mRNA accumulation and the release of the cytokines TNF-alpha and IL-6 was determined in leukemic cells isolated from bone marrow biopsy from patients with acute lymphoblastic leukemia: ALL-common type (cALL), 11 patients; ALL-T type, nine patients. The non-leukemic bone marrow cells (BMMC) and peripheral blood mononuclear cells (PBMC) from healthy donors were used as a control. The mRNA was assessed by fluorescent in situ hybridization in cell suspension and analyzed with flow cytometry. The accumulation of cytokine mRNA was higher in cALL cells as compared to ALL-T and PBMC (control) and was comparable to cytokines mRNA accumulation in BMMC. The production of IL-6 by leukemic cells from both types of leukemia was significantly lower than in BMMC. The bioactive TNF was not detected in either of the leukemia groups studied. TNF-alpha protein was produced by ALL-T cells and BMMC but not by cALL type of leukemic cells. The synthesis of IL-6 was significantly enhanced by TNF-alpha in BMMC and ALL-T while the presence of TNF-alpha had no effect on IL-6 synthesis in the culture of cALL leukemic cells. It was concluded that despite IL-6 and TNF-alpha mRNA contents, leukemic cells representing early stage of B-cell development (CD10+) showed disregulation of production of these cytokines.

The question was asked whether tumour necrosis factor alpha (TNF) is involved in regulation of interferon gamma (IFN gamma) production by T cells. Monocytes were exposed to exogenous TNF or to TNF synthesis inhibitors (pentoxifylline, PTX and adriamycin, ADR) and then used as antigen (PPD) presenting cells for autologous T cells. The ability of T lymphocytes to release IFN gamma was assessed after 3 days of culture. Preincubation of monocytes with rTNF enhanced their ability to induce IFN gamma production while TNF synthesis inhibitors decreased it. Anti-TNF and anti-TNF-R2 monoclonal antibodies (mAbs) inhibited monocyte ability to present PPD for IFN gamma production which suggested that endogenously produced TNF by monocytes had to be released and acted on TNF-R2 on the monocyte surface. The enhancing effect of exogenous TNF was also abrogated by anti-TNF-R2 mAb. Pretreatment of monocytes with rTNF enhanced, while pretreatment with PTX decreased, PPD-induced IL-6 production. An increased production of IL-4 was found in cultures of PTX-treated, PPD-pulsed monocytes with T cells. This may indicate that in the relative absence of monocyte costimulatory signal(s), probably IL-6, Th2 cells are stimulated. These results indicate that TNF is involved in control of monocyte-mediated regulation of cytokine production by T cells.