Changes in U937 cell viability induced by stress factors - possible role of calmodulin.

Current studies were aimed to elucidate influence of magnetic field (MF) stimulation on cell viability and its effect on expression of calmodulin (CaM) and Hsp70 protein which plays a role of cell stress indicator and is a Ca2+-dependent CaM-binding protein. For the experimental model we have chosen U937 cell line exposed to chemical- and/or physical stress factors. Puromycin (PMC) was used as a chemical apoptosis inducer. Alternating (AC) (6.5rms mT, 35 Hz) magnetic field combined with 6 mT static (DC) component, or pulsed electromagnetic field (45 ± 5)mT, 50 Hz (PEMF) acted as physical stressors. Cell viability was assessed by flow cytometry, and the Western blot analysis was carried out for CaM and Hsp70 levels in cytosolic extracts of U937 cells. Cell viability in samples exposed to MF alone did not differ from sham sample, for both types of MF exposure systems. Simultaneous action of MF and PMC influenced cell viability in type of MF stimulation-dependent manner. In contrast to PEMF + PMC stimulated samples, combination of ACDCMF with PMC enhanced cell death compared to PMC control. The observed changes in cell viability were correlated with changes in level of CaM and Hsp70 proteins. Immunoblots have shown, that cytosolic content of both CaM and Hsp70 proteins was enhanced in PMC-treated sample, and further elevated for ACDCMF + PMC. For PEMF + PMC stimulated samples, level of CaM was reduced compared to PMC-treated sample. The results suggest that the changes in expression of CaM and CaM-dependent proteins might modulate effectiveness of cell death under stimulation with MF and/or cytotoxic agents.

The effect of LPS injections on non-specific immune response in affected pigeons.

The aim of the study was to investigate the effect of LPS injections on non-specific mechanisms of immunity in pigeons. On the first day of observation the experimental birds (n=18) were intravenously injected with Escherichia coli LPS (10 microg/kg b.w.), while the control animals (n=6) received in the same way apyrogenic physiological saline. On the second and the third day of the experiment LPS in the same doses was injected again. Four and a half hours after the saline and each pyrogen administration blood samples were collected from the control and experimental pigeons. The total protein, gamma globulin, lysozyme, acute phase protein (Cp, CRP, Tf, ferritin, Alb) and selected trace element (Fe, Cu, Zn) concentrations were investigated. The obtained results showed the increase in the concentration of total protein, Cp, CRP and Tf in endotoxin fever resulting from LPS injection in pigeons. In contrast, the concentration of gamma globulins, ferritin and A1lb were decreased in response to the first LPS injection. However, the consecutive injections of LPS caused a decrease in the concentration of total protein, CRP and Tf. In opposition to those results, a significant rise in the lysozyme and ferritin concentrations was observed. On the other hand, the first LPS injection caused a decline in the iron and zinc concentrations which remaining lower than the control values following repeated administration of LPS. On the contrary, the copper concentration increased successively in response to the next LPS injections.

A strategic development model for the role of the biomedical physicist in the education of healthcare professionals in Europe.

This is the third of a series of articles targeted at biomedical physicists providing educational services to other healthcare professions, whether in a university faculty of medicine/health sciences or otherwise (e.g., faculty of science, hospital-based medical physics department). The first paper identified the past and present role of the biomedical physicist in the education of the healthcare professions and highlighted issues of concern. The second paper reported the results of a comprehensive SWOT (strengths, weaknesses, opportunities, threats) audit of that role. In this paper we present a strategy for the development of the role based on the outcomes of the SWOT audit. The research methods adopted focus on the importance of strategic planning at all levels in the provision of educational services. The analytical process used in the study was a pragmatic blend of the various theoretical frameworks described in the literature on strategic planning research as adapted for use in academic role development. Important results included identification of the core competences of the biomedical physicist in this context; specification of benchmarking schemes based on experiences of other biomedical disciplines; formulation of detailed mission and vision statements; gap analysis for the role. The paper concludes with a set of strategies and specific actions for gap reduction.

Pulsating electromagnetic field stimulation prevents cell death of puromycin treated U937 cell line.

Aim of study was to verify whether pulsating electromagnetic field (PEMF) can affect cancer cells proliferation and death. U937 human lymphoid cell line at densities starting from 1 x 10(6) cells/ml to 0.0625 x 10(6) cells/ml, were exposed to a pulsating magnetic field 50 Hz, 45+/-5 mT three times for 3 h per each stimulation with 24 h intervals. Proliferation has been studied by counting number of cells stimulated and non-stimulated by PEMF during four days of cultivation. Viability of cells was analyzed by APC labeled Annexin V and 7-AAD (7-amino-actinomycin D) dye binding and flow cytometry. Growing densities of cells increase cell death in cultures of U937 cells. PEMF exposition decreased amount of cells only in higher densities. Measurement of Annexin V binding and 7-AAD dye incorporation has shown that density-induced cell death corresponds with decrease of proliferation activity. PEMF potentiated density-induced death both apoptosis and necrosis. The strongest influence of PEMF has been found for 1 x 10(6)cells/ml and 0.5 x 10(6) cells/ml density. To eliminate density effect on cell death, for further studies density 0.25 x 10(6) cells/ml was chosen. Puromycin, a telomerase inhibitor, was used as a cell death inducer at concentration 100 microg/ml. Combined interaction of three doses of puromycin and three fold PEMF interaction resulted in a reduced of apoptosis by 24,7% and necrosis by 13%. PEMF protects U937 cells against puromycin- induced cell death. PEMF effects on the human lymphoid cell line depends upon cell density. Increased density induced cells death and on the other hand prevented cells death induced by puromycin.

A comprehensive SWOT audit of the role of the biomedical physicist in the education of healthcare professionals in Europe.

Although biomedical physicists provide educational services to the healthcare professions in the majority of universities in Europe, their precise role with respect to the education of the healthcare professions has not been studied systematically. To address this issue we are conducting a research project to produce a strategic development model for the role using the well-established SWOT (Strengths, Weaknesses, Opportunities, Threats) methodology. SWOT based strategic planning is a two-step process: one first carries out a SWOT position audit and then uses the identified SWOT themes to construct the strategic development model. This paper reports the results of a SWOT audit for the role of the biomedical physicist in the education of the healthcare professions in Europe. Internal Strengths and Weaknesses of the role were identified through a qualitative survey of biomedical physics departments and biomedical physics curricula delivered to healthcare professionals across Europe. External environmental Opportunities and Threats were identified through a systematic survey of the healthcare, healthcare professional education and higher education literature and categorized under standard PEST (Political, Economic, Social-Psychological, Technological-Scientific) categories. The paper includes an appendix of terminology. Defined terms are marked with an asterisk in the text.

Alpha-ketoglutarate protects the liver of piglets exposed during prenatal life to chronic excess of dexamethasone from metabolic and structural changes.

Glucocorticoids play a role in the origin of the features of the metabolic diseases. Alpha-ketoglutarate (AKG) is defined as glutamine homologue and derivative, conditionally an essential amino acid. In the liver, glutamine serves as a precursor for ureagenesis, gluconeogenesis and acute phase protein synthesis The aim of the study was to determine the effect of AKG administered to piglets prenatally exposed to dexamethasone, on the structure of the liver and its metabolic function. Sows were administered with dexamethasone (3 mg/sow/48 h) from day 70 of pregnancy to the parturition, and then after the birth, the piglets were divided into the group administered with AKG (0.4 g/kg body weight) or physiological saline. Biochemical markers, lysozyme and ceruloplasmin serum activities, concentrations of selected free amino acids, macro- and microelements and histomorphometry of the liver tissue were determined. The total cholesterol concentrations in the sows and their newborns from the Dex groups were higher by 72% and 64%, respectively, compared with the control groups. Triacylglycerol concentration was higher by 50% in sows from the Dex group and 55% in the new-born piglets. Alpha-ketoglutarate administered to the piglets after prenatal influence of dexamethasone lowered the total cholesterol concentration by 40%, and enhanced aspartate by 41%, serine by 76%, glutamate by 105%, glutamine by 36%, glycine by 53% and arginine by 105%, as well as methionine and cystathionine, but increased the sulphur concentration compared with the control (p < 0.01). Intracellular space D decreased after AKG administration in comparison with the piglets from Dex/Control group not treated with AKG. Postnatal administration of AKG had a protective effect on liver structure, and lowered the total cholesterol concentration in piglets prenatally exposed to dexamethasone, and also influenced selected macro- and microelement serum concentrations and amino acids plasma concentration.

The role of the biomedical physicist in the education of the healthcare professions: an EFOMP project.

The role of the biomedical physicist in the education of the healthcare professions has not yet been studied in a systematic manner. This article presents the first results of an EFOMP project aimed at researching and developing this important component of the role of the biomedical physicist. A background to the study expands on the reasons that led to the need for the project. This is followed by an extensive review of the published literature regarding the role. This focuses mainly on the teaching contributions within programmes for physicians, diagnostic radiographers, radiation therapists, and the postgraduate medical specializations of radiology, radiotherapy, interventional radiology and cardiology. Finally a summary list of the specific research objectives that need to be immediately addressed is presented. These are the carrying out of a Europe-wide position audit for the role, the construction of a strategic role development model and the design of a curriculum development model suitable for modern healthcare professional education.

Magnetic field anti-inflammatory effects in Crohn's disease depends upon viability and cytokine profile of the immune competent cells.

AIM: We investigated effects of pulsating electromagnetic field (PEMF-50 Hz, 45 +/- 5 mT) on viability and cytokine production by human peripheral blood mononuclear cells (PBMC) from healthy donors and from Crohn's disease patients (CD). METHODS: The study was performed after activation of cells with phytohaemaglutinin (PHA) and lipopolisaccharide (LPS). Exposure of PBMC cultures to PEMF from both CD patients and from healthy donors decreased cell's viability of about 10% and 5% (p>0.05) respectively. PEMF influence was most effective after threefold application. Susceptibility of PBMCs to magnetic field exposure differs among the stimulated (PHA, LPS) and not stimulated (NS) cells. Mitogen activated cells during cell division are most susceptible to induction of the cell death as a result of magnetic interaction, contrary PEMF exposure has minimal effect on non-diving PBMCs from CD patients and from controls. Decreased viability of the Crohn derived cells upon magnetic stimulation was accompanied by altered cytokines profile. Exposed and stimulated PBMCs from Crohn patients decreased IFN-gamma proinflammatory and increased IL-10 anti-inflammatory cytokine production. The electromagnetically induced cell death could be an important step for non-invasive PEMF treatment in chronic inflammatory diseases.

Bone tissue incorporates in vitro gallium with a local structure similar to gallium-doped brushite.

During mineral growth in rat bone-marrow stromal cell cultures, gallium follows calcium pathways. The dominant phase of the cell culture mineral constitutes the poorly crystalline hydroxyapatite (HAP). This model system mimics bone mineralization in vivo. The structural characterization of the Ga environment was performed by X-ray absorption spectroscopy at the Ga K-edge. These data were compared with Ga-doped synthetic compounds (poorly crystalline hydroxyapatite, amorphous calcium phosphate and brushite) and with strontium-treated bone tissue, obtained from the same culture model. It was found that Sr(2+) substitutes for Ca(2+) in the HAP crystal lattice. In contrast, the replacement by Ga(3+) yielded a much more disordered local environment of the probe atom in all investigated cell culture samples. The coordination of Ga ions in the cell culture minerals was similar to that of Ga(3+), substituted for Ca(2+), in the Ga-doped synthetic brushite (Ga-DCPD). The Ga atoms in the Ga-DCPD were coordinated by four oxygen atoms (1.90 A) of the four phosphate groups and two oxygen atoms at 2.02 A. Interestingly, the local environment of Ga in the cell culture minerals was not dependent on the onset of Ga treatment, the Ga concentration in the medium or the age of the mineral. Thus, it was concluded that Ga ions were incorporated into the precursor phase to the HAP mineral. Substitution for Ca(2+ )with Ga(3+) distorted locally this brushite-like environment, which prevented the transformation of the initially deposited phase into the poorly crystalline HAP.

Stochastic simulations of remodeling applied to a two-dimensional trabecular bone structure.

In this investigation the stochastic dynamics of trabecular bone remodeling (which is a key concept in a range of remodeling models) is verified. For this purpose, two-dimensional binary images of horizontal histological sections of lumbar vertebral bone (L-3) were collected from young and old subjects. Then the stochastic algorithm of remodeling was applied to the images of young trabecular bone. The resulting images of "simulated" old structures and those of "real" old structures were analyzed to evaluate the following architectural parameters: bone volume/trabecular volume; mean area of marrow cavities; mean trabeculae length; marrow space star volume; Euler number density; trabecular thickness; trabecular number; trabecular separation; mean two-point distance along the skeleton of trabecular structure; probability of disconnection; the ratio of marrow space star volume to geometrical volume and dimensionless ratio of mean area of marrow cavities; and mean trabecular length squared (form factor). Using the parametric t-test, the groups of simulated and real old bone images were compared. It is found that the p value of the t-test is never less than 0.20. For eight parameters the p value is >0.45. It is concluded that, as long as the horizontal sections of lumbar vertebrae are considered (sections perpendicular to the direction of the main spine load), the stochastic algorithm of bone remodeling will properly reproduce the architectural properties of trabecular bone.

Optimizing the assessment of age-related changes in trabecular bone.

The goal of this study was to develop an optimal procedure to determine age-related changes in trabecular bone. The investigations were based on two-dimensional images of the human vertebral trabecular bone specimens. The following indices of trabecular structure were considered: bone volume/total volume, star volume of the marrow cavity, Euler number and the probability of disconnection (straightforwardly connected with the number of separated parts of the network). To follow precisely the changes in the trabecular structure with age, a computer simulation model was used. Up to 35 years of physiological remodelling were simulated. The validation of the model calculations was based on a quantitative comparison with the data measured for older individuals. The simulations confirmed that the description of the age-related changes in the trabecular bone by means of the architectural parameter (star volume) constitutes a promising tool for subjects older than approximately 50 years. For individuals younger than approximately 50 years bone mineral density (bone volume/total volume) seems to be the best suited descriptor. The results suggest that the optimal diagnostic procedure is age-dependent and should not be limited to the bone mineral density measurement. The clinical usefulness of the procedure has been validated by examination of the CT images.

Dysregulation of monocyte oxidative burst in streptococcal endocarditis.

BACKGROUND: Streptococcal subacute endocarditis is characterized by low-grade systemic inflammation. Although structural cardiac defects are pivotal, phagocytic cells, i.e. monocytes and neutrophils, are involved in the induction and the course of bacterial endocarditis. Decreased production of reactive oxygen metabolites was described in long-lasting infections. We hypothesized that the oxidative burst of phagocytes induced by the infecting organism is defective in patients with streptococcal endocarditis. PATIENTS AND METHODS: The monocytes and neutrophils of 11 patients with streptococcal native valve endocarditis were challenged with the respective pathogens and two control streptococcal strains, and the oxidative burst was determined by fluorescence-activated cell sorter analysis. These experiments were done before any antibiotic therapy was administered, and repeated at least 12 months after recovery. Eight volunteers served as healthy controls. RESULTS: The monocyte response to the respective pathogens was decreased in the patient groups compared to the response to the control streptococci. After cure the monocyte response to the pathogens was not different to the response to the control strains. The monocyte response of the healthy volunteers did not show any differences between the patients' pathogens and the control strains. The neutrophil oxidative burst to the pathogens was similar to that to the control streptococci in both patient and the volunteer group. CONCLUSION: The decreased response of patient monocytes to the pathogens may contribute to the low-grade inflammatory response and to the course of streptococcal endocarditis.

Urease prevents adherence of Helicobacter pylori to Kato III gastric epithelial cells.

The role of urease in Helicobacter pylori adherence to and internalization by Kato III cells was investigated. Kato III cells were incubated with wild-type strains (N6 or P1), with isogenic mutants lacking urease (N6ureB::TnKm or P1ureA::TnMax5) or producing the inactive apoprotein (N6ureG::TnKm), and with urease-positive clones recovered after complementation of N6ureB::TnKm with ureAB. Bacteria were stained with the green fluorescent dye PKH2, and the bacteria load of cells was analyzed by flow cytometry. With mutants lacking urease, the bacteria load was considerably increased, in comparison with the corresponding parental strains (P<.001). With clone K2(3), producing larger amounts of urease than N6, a significant reduction of bacteria load was observed, in comparison with the wild type (P<.001). N6ureG::TnKm showed adherence characteristics similar to those of N6. The role of urease in internalization was not clear. Thus, urease significantly inhibits H. pylori adherence to Kato III cells by a mechanism largely independent of enzymatic activity.

Genetic complementation of the urease-negative Helicobacter pylori mutant N6ureB::TnKm.

Helicobacter pylori produces urease composed of the structural subunits UreA and UreB. Isogenic mutants produced by shuttle mutagenesis from the wild-type strain N6 are widely used in the literature. We describe the genetic complementation of the mutant N6ureB::TnKm by stable transformation with the vector pHel2 containing the cloned genes ureA and ureB and their specific promoter sequence. The orientation of the cloned insert was found to be crucial for urease expression. The majority of complemented clones functionally expressed urease at higher levels than did N6. Homologous recombination between chromosomal and cloned genes occurred at a frequency of 5%.

[Presence of the trace elements from carbon dioxide absorbent containing lime using a circular apparatus during general anesthesia. ]. / Obecnosc pierwiastków sladowych w wapnie absorbujacym dwutlenek wegla w ukladzie okreznym aparatu do znieczulenia.

The aim of the study was to evaluate release of the trace elements from carbon dioxide absorbent containing soda lime during general anesthesia. We compared two suppliers Polish "Polfa" and German "Dräger". Following trace elements were evaluated: chromium, copper, zinc, cadmium, lead, nickel in soda lime. In blood of the patients we evaluated: copper, zinc, lead, cadmium, bromine, rubidium, iron, mercury. Proton Induced X-ray Emission (PIXE) was used to measure concentrations of the elements. Probes of soda lime were analyzed before anesthesia (Polfa, Dräger), 6 hr after the use (Polfa only) and after 10 weeks (Dräger only). 10 patients were divided in two equal groups, one was anesthetized using soda lime from Polfa and another one from Dräger. Blood samples were taken before anesthesia, immediately after and the next day. Mean values of the concentrations of the elements in soda lime coming from Polfa ranged from 0.20 ppm (nickel) to 7.19 ppm (zinc). In Dräger the measurements were from 0.22 ppm (nickel) to 3.70 ppm (zinc). Mean concentrations of trace elements in blood samples were between 0.20 ppm (lead) and 487 ppm (iron) for the patients anesthetized with Polfa soda lime. In Dräger the measurements ranged from 0.15 ppm (lead) to 485 ppm (iron). Concentrations of cadmium and mercury were below the method's limit. Mean values were almost the same in all time points. Statistical analysis was done using paired t-tests. Values of P < 0.05 were consider significant. We concluded that there were no statistically significant differences between examined groups. Thus, we can say that trace elements were not released from soda lime and concentrations of examined elements in patients' blood were not affected by general anesthesia.

Transport of traffic-related aerosols in urban areas.

This study was undertaken to assess the influence of traffic on particulate air pollution in an urban area, and to characterise the short-range transport of the aerosols generated by traffic. The study was conducted in Kraków, a city located in southern Poland with a population of approximately 800,000. Aerosol samples were collected using automatic sampling equipment at five sites located at different distances from the main road in Kraków, ranging from 5 to 1500 m. The sampling set-up allowed standardisation of the results due to continuous determination of the meteorological parameters (temperature, atmospheric pressure, wind speed and direction, rainfall and humidity). Aerosol particles were separated according to aerodynamic diameter into two size fractions: > 1.9 microm (coarse fraction); and 1.9-72 microm (fine fraction). The concentrations of 27 elements were measured in both size fractions (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Zr, Ba, Pb). The multielement analyses were performed by Particle-Induced X-ray Emission (PIXE) spectrometry. Traffic contribution to particulate air pollution was determined on the basis of 13 elements which were present above the detection limit in all samples (Mg, Al, Si, P, S, K, Ca, Ti, Mn, Fe, Cu, Zn, Pb). It was found that the traffic contribution in the coarse size fraction was approximately 80% up to 150 m from the road; it dropped abruptly by a factor of 2 over a distance of 150-200 m and declined further to 20% at 1500 m from the road. Traffic contribution for the fine particle concentrations of individual elements was 50-70% in the close vicinity of the road (5 m); then there was a decrease, followed by an increase at a greater distance from the road. Possible explanations for this behaviour of the fine particles are given.

Comparison of trabecular bone architecture in young and old bones.

In this study, different parameters currently applied for the description of trabecular bone architecture in young and old subjects are compared. Moreover, new parameters are proposed and assessed. For the investigations, the two-dimensional images of vertebral body sections are acquired with the use of a low-magnification digital camera. The parameters were calculated both for the skeleton and for the bone/marrow interface distinguished in the images of the trabecular network. The following methods of the descriptions of the trabecular bone architecture were considered: histomorphometric analysis (BV/TV, asymmetry, mean trabeculae length), fractal geometry technique, Euler characteristic, star volume of the marrow cavity, the mean distance between two points of the trabecular network, and the probability of disconnection (is straightforwardly connected with the number of separated parts of the network). Moreover, bone mineral density (BMD) was determined for comparative purposes. The quantities directly extracted form the images are also combined to produce new indexes, which better differentiate young and old bones. It was found that the BMD, the BV/TV, the star volume, the Euler number, and the probability of disconnection might be used as indicators of the age-related changes of trabecular bone. The parameters could be measured with the precision comparable to that of the BMD. The only exception is the probability of disconnection. Highly significant correlations were demonstrated between bone density (BMD, BV/TV) and trabecular architecture (SV/GV, probability of disconnection).

Purification of surface-associated urease from Helicobacter pylori.

Helicobacter pylori colonizes the human gastric mucosa and produces large amounts of urease. The enzyme was extracted from the bacteria by distilled water and purified by gel-permeation (Sephacryl S-300), anion-exchange chromatography (Mono Q) and a second gel-permeation (Superdex 200). Urease enzyme activity was detected with a spectrophotometic assay based on phenol red. The optimal pH for anion-exchange was 6.9. The recovery of urease was 55-75%, purity 93-98% and the overall protein recovery 0.8-1.4%. The urease in the final extract still had enzymatic activity and showed the typical subunits of Mr 66000 and Mr 30000 when subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

[Adaptation of computed tomography and roentgenography to bone density measurements]. / Adaptacja tomografii komputerowej i rentgenografii do pomiarów densytometrycznych tkanki kostnej.

The increasing interest in issues connected with osteoporosis has recently caused the development of many new diagnostic methods which allow the measurement of bone density. The DEXA method, performed by specialised densitometers, is one of the most developed and reliable methods. However, the high cost od densitometers and DEXA investigation prevent this method from becoming easily accessible for everyday diagnosis. The adaptation of computerised tomography and rentgenography to densitometric measurements could be one of the methods by which the problem of densitometric diagnosis accessibility could be solved. Both methods are usually applied in the imaging of human tissues, working on the basis of differences in tissue X-ray absorption. X-ray absorption and density are related by linear function in the energy range used in rentgenography and tomography; therefore, quantitative information concerning density should be easily received. The procedure adapting computerised tomography and rentgenography to quantitative measurements of bone density in the lumbar spine is outlined in this work. The quantitative information is obtained from digitalised tomographic and rentgenographic images through use of a personal computer. Both methods were tested using a set of phantoms imitating the lumbar spine and the surrounding tissues. The precision and accuracy of both methods were assessed and compared to the precision and accuracy of the DEXA method. The outlined results confirm the usefulness of the described method in diagnosis.

Helicobacter pylori urease significantly reduces opsonization by human complement.

The role of Helicobacter pylori urease in opsonization by human complement was investigated. H. pylori wild type strain N6 and isogenic mutants lacking either the large urease subunit (UreB) or an accessory urease protein (UreG) were incubated with different sera. C3b bound to the bacteria was measured by specific staining and flow cytometry. As compared with opsonization of N6 and the UreG-lacking mutant, opsonization of the UreB-lacking mutant was significantly increased after incubation with sera from both H. pylori uninfected (P<.001) or infected (P<.05) persons. However, when sera from uninfected persons were used, effective opsonization of this mutant proved to be dependent mainly on the classical pathway of complement activation. Irrespective of the serum used, opsonization values were very low after selective inactivation of the classical or the alternative pathway. Reduced opsonization of the urease-expressing strains could, to some extent, result from degradation of bound C3b.