An investigation of secondary electron emission from ZnO based nanomaterials for future applications in radiation detectors.

This paper discusses the use of nanomaterials for the improved performance of time-of-flight particle detectors based on secondary electron emission (SEE). The purpose of the research presented in this paper is to find a nanomaterial that has a higher SEE than gold. In this article, we present a measurement of the SEE properties from 1D (one-dimensional) nanostructures of ZnO and ZnO/GaN (ZnO with GaN coating) composed of a mostly regular pattern of nanotubes grown on a thin Si3N4 substrate. The study was performed with 4.77 meV/u Au beam. We observed an average increase of 2.5 in the SEE properties from the 1D ZnO nanotubes compared to gold.

Immunomodulation inhibits the development of endometriosis in rats.

Endometriosis, the presence of ectopic endometrium, has an unclear etiology and is commonly associated with endocrine, genetic, and immunological imbalance. This study determined whether immunomodulation by the RESAN vaccine could alter the potentially pathogenic gene expression profiles in the cells of the eutopic endometrium in an animal model of endometriosis. Preventing these changes could inhibit the early development of the illness and support the success of surgical treatment. Wistar rats were divided into three groups: prophylaxis (vaccinated before ectopic endometrium implantation, n = 23), therapeutic (vaccinated at the time of the ectopic excision, n = 23) and control (n = 10). During the first laparotomy, autotransplantation of the endometrium to the peritoneum was performed in the prophylaxis and therapeutic groups. The second laparotomy was carried out three months later in all groups to examine endometriotic foci and adhesions. Suspected endometriosis foci were removed. Three months later, the third laparotomy was performed in all animals, followed by suspected foci excision. Fragments of the eutopic endometrium were collected from all animals during the first and third laparotomies. All samples were analysed by real-time PCR to assess the expression of Bcl2, Bax, Bax/Bcl2 ratio, Mki67, and Tert genes. Endometrial foci were found in abdominal peritoneum at the second laparotomy in 1 animal in the prophylaxis group, compared to 16 animals in the therapeutic group. The prophylaxis group showed a high expression of Bax while the therapeutic group showed high expression of Bax, Tert and Mki67 genes. Additional analysis revealed that throughout the six months of the experiment, the expression of the Bax, Tert, and Mki67 genes decreased significantly in the prophylaxis group, Mki67 gene expression decreased in the therapeutic group, and Tert, Mki67, and Bcl2 gene expression decreased in the control group. The results indicate that immunomodulation affects the balance between apoptosis and proliferation in the eutopic endometrium and may prevent the onset and recurrence of endometriosis.

Propagation-based x-ray phase-contrast tomography of mastectomy samples using synchrotron radiation.

PURPOSE: Propagation-based phase-contrast computed tomography (PB-CT) is a method for three-dimensional x-ray imaging that utilizes refraction, as well as absorption, of x rays in the tissues to increase the signal-to-noise ratio (SNR) in the resultant images, in comparison with equivalent conventional absorption-only x-ray tomography (CT). Importantly, the higher SNR is achieved without sacrificing spatial resolution or increasing the radiation dose delivered to the imaged tissues. The present work has been carried out in the context of the current development of a breast CT imaging facility at the Australian Synchrotron. METHODS: Seven unfixed complete mastectomy samples with and without breast cancer lesions have been imaged using absorption-only CT and PB-CT techniques under controlled experimental conditions. The radiation doses delivered to the mastectomy samples during the scans were comparable to those approved for mammographic screening. Physical characteristics of the reconstructed images, such as spatial resolution and SNR, have been measured and compared with the results of the radiological quality assessment of the complete absorption CT and PB-CT image stacks. RESULTS: Despite the presence of some image artefacts, the PB-CT images have outperformed comparable absorption CT images collected at the same radiation dose, in terms of both the measured objective image characteristics and the radiological image scores. The outcomes of these experiments are shown to be consistent with predictions of the theory of PB-CT imaging and previous reported experimental studies of this imaging modality. CONCLUSIONS: The results presented in this paper demonstrate that PB-CT holds a high potential for improving on the quality and diagnostic value of images obtained using existing medical x-ray technologies, such as mammography and digital breast tomosynthesis (DBT). If implemented at suitable synchrotron imaging facilities, PB-CT can be used to complement existing imaging modalities, leading to more accurate breast cancer diagnosis.

The classification of lung cancers and their degree of malignancy by FTIR, PCA-LDA analysis, and a physics-based computational model.

Lung cancer has the highest mortality rate of all malignant tumours. The current effects of cancer treatment, as well as its diagnostics, are unsatisfactory. Therefore it is very important to introduce modern diagnostic tools, which will allow for rapid classification of lung cancers and their degree of malignancy. For this purpose, the authors propose the use of Fourier Transform InfraRed (FTIR) spectroscopy combined with Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA) and a physics-based computational model. The results obtained for lung cancer tissues, adenocarcinoma and squamous cell carcinoma FTIR spectra, show a shift in wavenumbers compared to control tissue FTIR spectra. Furthermore, in the FTIR spectra of adenocarcinoma there are no peaks corresponding to glutamate or phospholipid functional groups. Moreover, in the case of G2 and G3 malignancy of adenocarcinoma lung cancer, the absence of an OH groups peak was noticed. Thus, it seems that FTIR spectroscopy is a valuable tool to classify lung cancer and to determine the degree of its malignancy.

Monitoring breast cancer treatment using a Fourier transform infrared spectroscopy-based computational model.

Breast cancer affects one in four women, therefore, the search for new diagnostic technologies and therapeutic approaches is of critical importance. This involves the development of diagnostic tools to facilitate the detection of cancer cells, which is useful for assessing the efficacy of cancer therapies. One of the major challenges for chemotherapy is the lack of tools to monitor efficacy during the course of treatment. Vibrational spectroscopy appears to be a promising tool for such a purpose, as it yields Fourier transformation infrared (FTIR) spectra which can be used to provide information on the chemical composition of the tissue. Previous research by our group has demonstrated significant differences between the infrared spectra of healthy, cancerous and post-chemotherapy breast tissue. Furthermore, the results obtained for three extreme patient cases revealed that the infrared spectra of post-chemotherapy breast tissue closely resembles that of healthy breast tissue when chemotherapy is effective (i.e., a good therapeutic response is achieved), or that of cancerous breast tissue when chemotherapy is ineffective. In the current study, we compared the infrared spectra of healthy, cancerous and post-chemotherapy breast tissue. Characteristic parameters were designated for the obtained spectra, spreading the function of absorbance using the Kramers-Kronig transformation and the best fit procedure to obtain Lorentz functions, which represent components of the bands. The Lorentz function parameters were used to develop a physics-based computational model to verify the efficacy of a given chemotherapy protocol in a given case. The results obtained using this model reflected the actual patient data retrieved from medical records (health improvement or no improvement). Therefore, we propose this model as a useful tool for monitoring the efficacy of chemotherapy in patients with breast cancer.

Optimization of propagation-based x-ray phase-contrast tomography for breast cancer imaging.

The aim of this study was to optimise the experimental protocol and data analysis for in-vivo breast cancer x-ray imaging. Results are presented of the experiment at the SYRMEP beamline of Elettra Synchrotron using the propagation-based phase-contrast mammographic tomography method, which incorporates not only absorption, but also x-ray phase information. In this study the images of breast tissue samples, of a size corresponding to a full human breast, with radiologically acceptable x-ray doses were obtained, and the degree of improvement of the image quality (from the diagnostic point of view) achievable using propagation-based phase-contrast image acquisition protocols with proper incorporation of x-ray phase retrieval into the reconstruction pipeline was investigated. Parameters such as the x-ray energy, sample-to-detector distance and data processing methods were tested, evaluated and optimized with respect to the estimated diagnostic value using a mastectomy sample with a malignant lesion. The results of quantitative evaluation of images were obtained by means of radiological assessment carried out by 13 experienced specialists. A comparative analysis was performed between the x-ray and the histological images of the specimen. The results of the analysis indicate that, within the investigated range of parameters, both the objective image quality characteristics and the subjective radiological scores of propagation-based phase-contrast images of breast tissues monotonically increase with the strength of phase contrast which in turn is directly proportional to the product of the radiation wavelength and the sample-to-detector distance. The outcomes of this study serve to define the practical imaging conditions and the CT reconstruction procedures appropriate for low-dose phase-contrast mammographic imaging of live patients at specially designed synchrotron beamlines.

An influence of immunomodulation on Th1 and Th2 immune response in endometriosis in an animal model.

AIM: To assess the role of the Th1 and Th2 cellular response in the etiology of endometriosis observed in a rat model, with the use of the RESAN immunomodulator. MATERIALS AND METHODS: A comparative analysis of cytokines in blood serum typical of Th1 (TNF-α and INF-γ ) and Th2 (IL-4, IL-6, IL-10) cell response in groups of rats, in which RESAN preparation was used as prophylaxis (Gr. I) or treatment (Gr. II) of endometriosis. RESULTS: The results indicated an increase in the level of cytokines in blood serum typical of Th2 cell response by comparing the second and third stages of the experiment in the second group of rats and a decrease in IL-4 and IL-10 between III and IV stages. There was a significant difference in cytokine levels during the third stage of the experiment by comparing I and II groups of rats. In the III group of rats, levels of IL-10 significantly increased between the II and III stages of the experiment. CONCLUSION: RESAN preparation shows Th2 cell response, inhibiting the development of endometriosis in a rat model. Due to successful prophylactic action, one may speculate that RESAN vaccine may be effective as a complementary treatment after surgical excision.

Lyophilized Carnobacterium divergens AS7 bacteriocin preparation improves performance of broiler chickens challenged with Clostridium perfringens.

The present study aimed to investigate the effects of Carnobacterium divergens AS7 bacteriocin (divercin AS7) on growth performance, digestibility, fermentation processes, selected microbial populations, and histomorphology in broiler chickens challenged with a mixture of 3 Clostridium perfringens isolates. In total, 480 one-day-old male Ross 308 chicks were randomly assigned to 4 experimental groups (12 replicate pens of 10 birds per treatment). The diets were either nonsupplemented or supplemented with a lyophilized preparation of divercin AS7. On d 18, 19, and 20, half of the birds were challenged twice a day with the C. perfringens mixture. The C. perfringens challenge did not influence broiler BW gain but impaired feed conversion ratio from d 29 to 42 (P=0.023) and throughout the experimental period (P=0.038). Moreover, the C. perfringens challenge resulted in decreased pH levels of crop, gizzard, and ileum contents (P<0.05) and reduced the numbers of lactic acid bacteria in the ceca (P=0.01). Divercin supplementation decreased broiler feed intake from d 14 to 28 (P=0.001) but increased BW gain from d 29 to 42 (P=0.048). The divercin supplementation increased the AMEn level (P=0.015) and reduced digesta pH in crop and ileum (P=0.004 and P=0.042, respectively), but of nonchallenged birds only. Divercin supplementation, moreover, increased gizzard lactate concentrations (P=0.003). The crop concentrations of lactate and succinate and the ileum concentration of lactate were increased by divercin supplementation (P=0.005, P=0.027, and P=0.002, respectively) and C. perfringens challenge (P=0.034, P=0.053, and P=0.0002, respectively). Divercin supplementation decreased villus heights (P=0.0006) and crypt depths (P=0.044) in noninfected birds, whereas in challenged birds, villus heights (P<0.0001) were increased. In conclusion, the present study demonstrated a very complex response pattern of broilers exposed to C. perfringens challenge and dietary divercin AS7 supplementation, but it indicated that divercin AS7 may partly counterbalance the negative effects associated with C. perfringens.

Multivariate analysis techniques in the forensics investigation of the postblast residues by means of Fourier transform-infrared spectroscopy.

Fourier transform-infrared (FT-IR) spectroscopy has gained considerable attention among the forensic scientists because it shows high sensitivity and selectivity and offers near real time detection of analyzed samples. However, the amount of obtained information due to complexity of the measured spectra forces the use of additional data processing. Application of the multivariate statistical techniques for the analysis of the FT-IR data seems to be necessary in order to enable feature extraction, proper evaluation, and identification of obtained spectra. In this article, an attempt to develop a feasible procedure for characterization of spectroscopic signatures of the explosive materials in the remnants after explosion has been made. All spectra were derived after analysis of samples from debris after especially prepared and performed blasts with the use of three various highly explosive materials: C-4, 2,4,6-trinitrotoluene (TNT), and pentaerythritol tetranitrate (PETN). Two well-known multivariate statistical methods, hierarchical cluster analysis (HCA) and principal component analysis (PCA), were tested in order to classify the samples into separate classes using a broad wavelength data range (4000-600 cm(-1)) on collected spectra sets. After many trials it seems that PCA is the best choice for the mentioned earlier tasks. It was found that only three principal components carry over 99.6% of variance within the sample set. The results show that FT-IR spectroscopy in combination with multivariate methods is well-suited for identification and differentiation purposes even in quite large data sets, and for that reason forensic laboratories could employ these methods for rapid screening analysis.

5-aminolevulinic acid-mediated photodynamic therapy of human endometriotic primary epithelial cells.

OBJECTIVE: Despite progress in medicine, appropriate diagnosis and treatment of endometriosis poses a serious problem. For this reason, in in-vitro experiments were performed on a potential method of employing photodynamic therapy (PDT) of endometriosis using 5-aminolevulinic acid (ALA). BACKGROUND DATA: The exogenous application of ALA induces the accumulation of protoporphyrin IX, a natural and effective photosensitizer used in photodynamic diagnosis and therapy. MATERIALS AND METHODS: To this end primary epithelial cells were isolated from endometriotic foci, preincubated with various ALA concentrations, and then exposed to light energy (a bulb or laser) for 8 min; 24 and 48 h later cell lesions were evaluated using fluorescent staining. RESULTS: When bulb illumination was used, after 48 h cells were found that had disturbed chromatin concentration and fragmentation. Illumination with a laser beam resulted in strong induction of apoptosis 24 h post-exposure. With both types of illumination the number of necrotic cells was insignificant. Staining with rhodamine 123 demonstrated the presence within the endometriotic foci of epithelial cells that were resistant to ALA-induced photodynamic therapy. CONCLUSION: The effects of PDT on primary epithelial endometriotic cells may prove useful in designing a phototherapeutic procedure for the detection and treatment of endometriosis.

Photodynamic diagnosis (PDD) using 5-aminolevulinic acid-supplemented cultures of human endometrial epithelial cells.

PURPOSE: The studies were aimed at monitoring 5-aminolevulinic acid (5-ALA)-dependent accumulation of endogenous protoporphyrin IX (PpIX) in epithelial cells originating from normal endometrium or endometriotic foci, as related to steroid treatment. MATERIAL AND METHODS: Epithelial cells were cultured in presence of estradiol-17 beta (E2) and progesterone (P) in concentrations typical for the follicular stage (E2 alone, 220 pg/ml) or the luteal stage (E2 100 pg/ml and P 2 ng/ml) or in presence of progesterone alone (2 ng/ml) for a period of 24, 48 or 72 h. Effect of 5-ALA concentration on the accumulation of PpIX was defined in the cells incubated with 2.0 mmol/l 5-ALA for 2 h. PpIX fluorescence was detected using a confocal microscope. RESULTS: After hormonal stimulation, intensity of PpIX-specific fluorescence was only slightly increased in epithelial cells originating from normal endometrium. Cultures of epithelial cells from endometriosis foci showed higher concentration of PpIX than did the cells originating from normal endometrium. The highest peak of PpIX fluorescence was noted in epithelial endometriotic cells after 48h incubation with progesterone. CONCLUSIONS: The data on PpIX accumulation in epithelial cells in the presence of estradiol-17 beta or progesterone may provide indications as to the menstrual cycle phase(s) in which photodynamic therapy for endometriosis should be performed. It is concluded that hormonal condition of female body must be taken into account for diagnosis and treatment of endometriosis.

Effect of bromocriptine on cell apoptosis and proliferation in GH3 cell culture.

OBJECTIVES: In our study, with the use of GH3 cells line we decided to examine 1) what is the relation between the dose of bromocriptine and the development of apoptosis in GH3 cells 2) whether the induction of apoptosis is accompanied by alterations in bcl-2 and p53 content and 3) whether dibutyryl-cAMP or phorbol esters affect the initiation of apoptosis in GH3 cells. RESULTS: The current study demonstrated the absence of alterations in GH3 cells incubated for 24 h with bromocriptine at the concentrations of up to 15 micromol/l. Apoptotic and necrotic changes were observed after 48 h incubation with bromocriptine at the concentrations of 25 micromol/l. The ratio of necrotic to apoptotic cells increased at 40 micromol/l of bromocriptine concentration. An inhibitory effect of bromocriptine on cell proliferation was also observed. Phorbol-12-myristate-13-acetate (PMA), at concentrations ranging between 25 ng to 200 ng/ml, reduced the amount of apoptotic cells. CONCLUSIONS: Application of dibutyryl-cAMP at the concentration of 1 to 8 mmol/l resulted in an inhibition of apoptosis, followed by an increase in the number of cultured cells. Ultrastructural studies showed evident apoptotic lesions in the cells.

Effect of 5-aminolevulinic acid on kinetics of protoporphyrin IX production in CHO cells.

5-aminolevulinic acid (ALA) is utilized in a photodynamic therapy as a compound capable of augmenting intracellular pool of protoporphyrin IX (PpIX), which exhibits properties of a photosensitizer. The studies were aimed at monitoring accumulation of endogenous protoporphyrin IX in CHO cells under effect of various concentrations of ALA in culture medium and following removal of the compound from the culture medium. Cell content of PpIX was determined following incubation of the cells for 72 h in a culture medium containing different concentration of ALA. Moreover, the cells were preincubated for 2 h in ALA at various concentrations and separated from the compound by medium change and their PpIX content was monitored following incubation. PpIX content was defined by a fluorescent technique under the confocal microscope. In the course of continuous incubation of cells with ALA, biphasic alterations were noted in cellular PpIX concentration. Removal of ALA from the incubation medium resulted at first in a decrease in PpIX content in cells, which was followed by an evidently augmented accumulation of the compound in the cells. The results suggested that in the case of CHO cells, exogenous ALA was not an exclusive source of PpIX synthesis and that alterations in enzyme activities were responsible for production of PpIX.

Effect of 5-aminolevulinic acid (ALA) doses and oestrogen/progesterone on protoporphyrin IX (ppIX) accumulation in human endometrial epithelial cells.

Endometriosis represents one of the most frequent causes of restricted fecundity. Despite the progress in medicine, appropriate diagnosis and treatment pose significant problems. The aim of this study was to evaluate ALA-induced PpIX fluorescence of normal endometrial epithelial cells for the diagnosis of endometriosis. PpIX-fluorescence was measured after stimulation with estradiol-17 beta (E2) or with estradiol-17 beta (E2) and progesterone (P) and after incubation with ALA under a confocal microscope. The epithelial cells showed a significantly higher fluorescence of PpIX in the course of 24 and 48h incubation with hormones, than the cells without stimulation. After 72h, a significant decrease in cellular PpIX concentration was noted. The results suggested that E2 and P were required to convert ALA to PpIX in epithelial cells and increased PpIX concentration in a time-dependent fashion.

The influence of photodynamic reaction on R2C cells.

Photodynamic therapy (PDT) represents a therapeutic approach in which photosensitised neoplastic cells undergo destruction under effect of light. In this study we have attempted to define effects of photochemotherapy on R2C cells, sensitised with protoporphyrin IX (PpIX) and to find out whether inhibition of gene expression by cycloheximide affects development of lesions in the cells. The photosensitised cells were exposed to visible light and development of apoptotic and necrotic lesions was followed in the cells, using the fluorescent staining with propidium iodide and Hoechst 33342. The experiments demonstrated that PpIX and light, acting in parallel, induce development of apoptotic and necrotic lesions in R2C cells. Intensity of the lesions correlated with concentration of the applied photosensitiser and with duration of light exposure. Using cycloheximide, we also inhibited protein expression in cells photosensitised with protoporphyrin before they were exposed to light. In the latter case, development of apoptosis was clearly intensified which might be explained by inhibition of anti-apoptotic protein synthesis in the cells.

Studies on the effect of photodynamic therapy on in vitro cultured neoplastic cells.

Photodynamic therapy (PDT) represents a therapeutic approach in which photosensitised neoplastic cells undergo destruction under the effect of light. In this study we have attempted to define effects of PDT on CHO cells, sensitised with protoporphyrin IX (PpIX). The photosensitised CHO cells were exposed to a visible light and development of apoptotic and necrotic lesions was followed in the cells, using the fluorescent staining with propidium iodide and Hoechst 33342. The experiments demonstrated that PpIX and light, acting in parallel, induce development of apoptotic and necrotic lesions in the cells. Intensity of the lesions was correlated with the concentration of the applied photosensibiliser and with the duration of exposure to light. The control experiments suggest that development of apoptosis in the applied model probably reflect mitochondrial damage, while processes developing close to the cell membrane are responsible for necrosis. In order to corroborate the obtained results, ultrastructural studies were performed on experimental groups in which evident apoptotic lesions were observed in the cells.

Effect of lectin from Chelidonium majus L. on normal and cancer cells in culture.

Lectin from Chelidonium majus L. (CML) significantly stimulates the proliferation of human lymphocytes and has hemagglutination activity towards group B human erythrocytes and potent antimicrobial properties against multiresistant enterococci and staphylococci. In the present work we describe the effect of lectin from Chelidonium majus L on normal and cancercells in culture in vitro. The studies were performed on three types of cells: CHO, R2C and on normal mouse fibroblasts. Effects on the cultures were examined 24 h after addition of CML. Exposure to CML resulted in growth inhibition of CHO and R2C cells but not of fibroblasts. Moreover, evident apoptotic lesions were observed in CHO cells and less well marked apoptotic lesions in R2C cells. In contrast, only insignificant numbers of fibroblasts reacted to the applied lectin.

[The assessment of the value of ultrasound and magnetic resonance imaging in diagnosing hand joint arthritis]. / Ocena przydatnosci ultrasonografii i rezonansu magnetycznego w diagnostyce zapalenia stawów rak.

The main imaging investigation used in diagnosing rheumatoid arthritis is radiography of the hands and feet. It allows visualisation of bone erosions--typical of the disease. However, bone erosions occur during the later stages of the rheumatoid arthritis and are preceded by synovitis. The aims of the study were to use ultrasound (US) and magnetic resonance imaging (MRI) in examining joints in patients suffering from chronic arthritis, and also to assess the value of these methods in diagnostics. In 61 patients with chronic arthritis (39 with rheumatoid arthritis--RA, and 22 with another etiology arthritis), plain radiography, US and MRI of the hands was performed. MRI and US were more sensitivity in visualisation of bone erosions than plain radiography. Both methods showed synovitis in all patients with RA. In detecting bone erosions in the hand joints MRI and US are more sensitive methods than plain radiography. Both methods detect synovitis and tenosynovitis. Inflammatory changes shown using the MRI and US are more intensive in RA than in patients suffering from another etiology arthritis.

Permeability, cytotoxicity, and genotoxicity of Cr(III) complexes and some Cr(V) analogues in V79 Chinese hamster lung cells.

The permeabilities and genotoxicities of the Cr(III) complexes [Cr(en)(3)](3+), mer-[Cr(glygly)(2)](-), cis-[Cr(phen)(2)(OH(2))(2)](3+), and trans-[Cr(salen)(OH(2))(2)](+) and the Cr(V) analogues of cis-[Cr(phen)(2)(OH(2))(2)](3+) and trans-[Cr(salen)(OH(2))(2)](+) [en being 1,2-ethanediamine, glygly being glycylglycine, phen being 1,10-phenanthroline, and salen being N,N'-ethylenebis(salicylideneiminato)] have been studied in V79 Chinese hamster lung cells. Following exposure of approximately 10(6) cells to 0.4 mM Cr(III) for 4 h, the Cr uptake by single cells was less than 10(-)(14) g/cell (as determined by GFAAS analysis and as confirmed by PIXE analysis where the Cr concentration was below the limit of detection). Importantly, the Cr(V) analogue of cis-[Cr(phen)(2)(OH(2))(2)] was significantly more permeable than the Cr(III) complex. The cytotoxicity of the Cr(III) complexes increased in the following order: mer-[Cr(glygly)(2)](-) < [Cr(en)(3)](3+) approximately cis-[Cr(phen)(2)(OH(2))(2)](3+) < trans-[Cr(salen)(OH(2))(2)](+). No genotoxic effects were observed following exposure to mer-[Cr(glygly)(2)](-) or [Cr(en)(3)](3+) at concentrations up to 6 mM. The Cr(III) imine complexes trans-[Cr(salen)(OH(2))(2)](+) and cis-[Cr(phen)(2)(OH(2))(2)](3+), which could be oxidized to Cr(V) complexes, induced MN in vitro at rates of 13.6 and 3.3 MN/1000 BN cells/micromol of Cr, respectively. The comparative permeabilities and genotoxicities of trans-[Cr(salen)(OH(2))(2)](+) and [CrO(salen)](+) were similar due to the instability of the Cr(V) complex at physiological pH values (7.4). There was a substantial increase in the permeability of [Cr(O)(2)(phen)(2)](+), compared to that of the Cr(III) analogue, which was accompanied by a highly genotoxic response. Consequently, any Cr(III) complex that is absorbed by cells and can be oxidized to Cr(V) must be considered as a potential carcinogen. This has potential implications for the increased use of Cr(III) complexes as dietary supplements and highlights the need to consider the genotoxicities of a variety of Cr(III) complexes when determining the carcinogenic potential of Cr(III) particularly when "high" deliberately administered doses are concerned.

Absolute value of the difference of Tl-201 uptake between redistribution and rest is a specific marker of myocardial viability.

Although Tl-201 rest redistribution SPECT is widely used to assess myocardial viability, there is no agreement on the best prognostic marker of left ventricle contraction improvement after revascularization. More recent data suggest that not only rest or redistribution uptake but also reverse redistribution patterns may serve to indicate the viability of myocardium. The aim of this study was to define criteria (which include reversibility and reverse redistribution) for viability testing and prediction of functional outcome in Tl-201 rest redistribution SPECT. Twenty-five patients with left ventricle dyssynergy were studied before and after revascularization with Tl-201 SPECT and echocardiography. Perfusion and contractility was assessed in a 16-segment model of the left ventricle. Out of 400 left ventricular segments, contraction disturbances of various degree of intensity (hypokinesis, akinesis and dyskinesis) were found by echocardiography in 107 segments. Revascularization was performed in 97 segments. In 57% of the segments, improvement of contraction was observed after PTCA or CABG. Perfusion was analysed in the segments between segments with and without contraction improvement. In discriminant analysis, only the modulus of difference between rest and redistribution study > or = 10% was the common parameter for hypo-, a- and dyskinetic segments to predict the functional recovery of left ventricle (LV) with the specificity of 93% and sensitivity of 78%. The modulus of segmental quantitative difference between redistribution and rest image is a new parameter adding specificity to Tl-201 rest redistribution SPECT in prediction of recovery of left ventricle function.