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931.
Wioleta Dudzinska Anna Lubkowska Barbara Dolegowska Krzysztof Safranow 《Journal of physiology and biochemistry》2010,66(3):189-196
During prolonged maximal exercise, oxygen deficits occur in working muscles. Progressive hypoxia results in the impairment
of the oxidative resynthesis of ATP and increased degradation of purine nucleotides. Moreover, ATP consumption decreases the
conversion of UDP to UTP, to use ATP as a phosphate donor, resulting in an increased concentration of UDP, which enhances
pyrimidine degradation. Because the metabolism of pyrimidine nucleotides is related to the metabolism of purines, in particular
with the cellular concentration of ATP, we decided to investigate the impact of a standardized exercise with increasing intensity
on the concentration of uridine, inosine, hypoxanthine, and uric acid. Twenty-two healthy male subjects volunteered to participate
in this study. Blood concentrations of metabolites were determined at rest, immediately after exercise, and after 30 min of
recovery using high-performance liquid chromatography. We also studied the relationship between the levels of uridine and
indicators of myogenic purine degradation. The results showed that exercise with increasing intensity leads to increased concentrations
of inosine, hypoxanthine, uric acid, and uridine. We found positive correlations between blood uridine levels and indicators
of myogenic purine degradation (hypoxanthine), suggesting that the blood uridine level is related to purine metabolism in
skeletal muscles. 相似文献
932.
933.
Beata Osiecka Kamil Jurczyszyn Krzysztof Symonowicz Andrzej Bronowicz Paweł Ostasiewicz Elżbieta Czapińska Katarzyna Hotowy Małgorzata Krzystek-Korpacka Elżbieta Gębarowska Ilona Iżykowska Piotr Dzięgiel Grzegorz Terlecki Piotr Ziółkowski 《Cellular & molecular biology letters》2010,15(4):630-650
Photodynamic therapy (PDT) is a well-known method for the treatment of malignant tumors, and its principles have been well established over the past 30 years. This therapy involves the application of a chemical called a photosensitizer and its subsequent excitation with light at the appropriate wavelength and energy. Topical photodynamic therapy with aminolevulinic acid (5-ALA) is an alternative therapy for many malignant processes, including nonmelanoma skin cancers such as basal-cell carcinoma (BCC). Our novel approach for this study was to use a liposomal formulation of 5-ALA and its methyl ester (commercially available as metvix) both in vitro and in vivo, and to check whether the liposome-entrapped precursors of photosensitizers can induce the expression of metalloproteinases (MMPs) in animal tumor cells and in other tissues from tumor-bearing rats and in selected cell lines in vitro. We also checked whether the application of tissue inhibitors of matrix metalloproteinases (TIMPs) has any effect on MMPs in the above-mentioned experimental models, and if they can cause complete inhibition of MMP expression. Immunohistochemical studies revealed that after the PDT, the intensity of expression of MMPs in healthy animals was very low and seen in single cells only. After the PDT in tumor-bearing rats, MMP-3 was expressed in the tumor cells with the highest intensity of staining in the tissues directly adjacent to the tumors, while MMP-2 and -9 were not found. In the control groups, there was no observed expression of MMPs. In vitro studies showed that MMP-3 was expressed in MCF-7 cells after PDT, but MMP-9 was not observed and MMP-2 was only seen in single cases. Our studies confirmed that the application of an MMP-3 inhibitor may block an induction of MMP-3 expression which had previously been initiated by PDT. The preliminary data obtained from cancer patients revealed that new precursors are effective in terms of PDT, and that using MMP inhibitors should be considered as a potential enhancing factor in clinical PDT. 相似文献
934.
Time-resolved fluorescence studies with a 3-ps temporal resolution were performed in order to: (1) test the recent model of the reversible primary charge separation in Photosystem I (Müller et al., 2003; Holwzwarth et al., 2005, 2006), and (2) to reconcile this model with a mechanism of excitation energy quenching by closed Photosystem I (with P700 pre-oxidized to P700+). For these purposes, we performed experiments using Photosystem I core samples isolated from Chlamydomonas reinhardtii wild type, and two mutants in which the methionine axial ligand to primary electron acceptor, A0, has been change to either histidine or serine. The temporal evolution of fluorescence spectra was recorded for each preparation under conditions where the “primary electron donor,” P700, was either neutral or chemically pre-oxidized to P700+. For all the preparations under study, and under neutral and oxidizing conditions, we observed multiexponential fluorescence decay with the major phases of ∼ 7 ps and ∼ 25 ps. The relative amplitudes and, to a minor extent the lifetimes, of these two phases were modulated by the redox state of P700 and by the mutations near A0: both pre-oxidation of P700 and mutations caused slight deceleration of the excited state decay. These results are consistent with a model in which P700 is not the primary electron donor, but rather a secondary electron donor, with the primary charge separation event occurring between the accessory chlorophyll, A, and A0. We assign the faster phase to the equilibration process between the excited state of the antenna/reaction center ensemble and the primary radical pair, and the slower phase to the secondary electron transfer reaction. The pre-oxidation of P700 shifts the equilibrium between the excited state and the primary radical pair towards the excited state. This shift is proposed to be induced by the presence of the positive charge on P700+. The same charge is proposed to be responsible for the fast A+A0− → AA0 charge recombination to the ground state and, in consequence, excitation quenching in closed reaction centers. Mutations of the A0 axial ligand shift the equilibrium in the same direction as pre-oxidation of P700 due to the up-shift of the free energy level of the state A+A0−. 相似文献
935.
Marcin Słojewski Bogusław Czerny Krzysztof Safranow Katarzyna Jakubowska Maria Olszewska Andrzej Pawlik Adam Gołąb Marek Droździk Dariusz Chlubek Andrzej Sikorski 《Biological trace element research》2010,137(3):301-316
The role of trace elements in lithogenesis is still unclear. The aim of this study was to evaluate the levels of elements
in urinary stones and in the urine and hair of stone formers to identify these elements that have synergic correlations in
studied materials and may contribute to lithogenesis. A total of 219 consecutive patients with idiopathic upper urinary tract
stones were prospectively enrolled in the study. Urine and hair samples were collected from all patients. The content of the
stone was evaluated using atomic absorption spectrometry, spectrophotometry, and colorimetric methods. The analysis of 29
elements in stones and hair and 21 elements in urine was performed using inductively coupled plasma-atomic emission spectrometry.
The strength of correlation was described with the value of Spearman’s rank correlation coefficient. The positive correlation
between concentration of sodium, potassium, magnesium, barium, vanadium, zinc, silicon, phosphorus, and iodine in phosphate
stones was observed. Only a few incidental correlations between the composition of stones and the distribution of elements
in urine and in hair were found. There were 109 positive two-element correlations between two materials. The most common were
observed for vanadium, aluminum, lead, cobalt, and molybdenum. Two-element positive correlations for all samples were established
only for three elements: vanadium, lead, and aluminum. Results indicate that analysis of particular elements in hair and urine
cannot predict the composition of urinary stones. This study showed, for the first time, correlations between the levels of
vanadium, lead, and aluminum in the stones, urine, and hair of stone formers. 相似文献
936.
Aleksandra Krolicka Anna Szpitter Krzysztof Stawujak Rafal Baranski Anna Gwizdek-Wisniewska Anita Skrzypczak Marian Kaminski Ewa Lojkowska 《Plant Cell, Tissue and Organ Culture》2010,103(3):285-292
Plants belonging to genus Drosera (family Droseraceae) contain pharmacologically active naphthoquinones such as ramentaceone and plumbagin. Hairy root cultures
obtained following Agrobacterium rhizogenes-mediated transformation have been reported to produce elevated levels of secondary compounds as well as exhibit desirable
rapid biomass accumulation in comparison to untransformed plants. The aim of this study was to establish hairy root or teratoma
cultures of Drosera capensis var. alba and to increase the level of ramentaceone in transformed tissue by application of abiotic and biotic elicitors. The appearance
of transformed tissues—teratomas but not hairy roots was observed 18 weeks after transformation. The transformation efficiency
was 10% and all teratoma cultures displayed about 3 times higher growth rate than non-transformed cultures of D. capesis. The transformation was confirmed by PCR and Southern hybridization using primers based on the A. rhizogenes
rolB and rolC gene sequences. HPLC analysis of ramentaceone content indicated 60% higher level of this metabolite in teratoma tissue in
comparison to non-transformed cultures. Among the elicitors tested jasmonic acid (2.5 mg l−1) turned out to be the most effective. The productivity of ramentaceone in elicited teratoma cultures was about sevenfold
higher than in liquid cultures of D. capensis var. alba and amounted to 2.264 and 0.321 mg respectively during 4 weeks of cultivation. This is the first report on the transformation
of Drosera plant with A. rhizogenes. 相似文献
937.
Zatonski T Bolanowski M Skrzypek A Morawska-Kochman M Kaluzny M Zatonska K Moron K Badowski R Krecicki T 《Neuro endocrinology letters》2010,31(6):796-800
OBJECTIVE: Acromegaly is a rare disease, which symptoms are caused by excess secretion of a growth hormone (GH) from the anterior pituitary benign tumor - adenoma. Authors present an evaluation of computed tomography (CT) and magnetic resonance (MR) images of temporal bone and paranasal sinuses of patients with acromegaly. CONCLUSIONS: 1. In all patients with acromegaly, morphological changes in paranasal sinuses were shown. They were mostly pronounced within the maxillary sinuses including the mucosa thickening up to 6 mm and encysted fluid occurrence. 2. CT of temporal bone did not reveal structural changes of internal and median ear. 3. There is a need for further studies on hearing impairment in patients with acromegaly. 相似文献
938.
Marcin Baranowski Agnieszka Blachnio-Zabielska Tomasz Hirnle Dorota Harasiuk Krzysztof Matlak Malgorzata Knapp Piotr Zabielski Jan Gorski 《Journal of lipid research》2010,51(1):74-80
Data from animal experiments strongly suggest that ceramide is an important mediator of lipotoxicity in the heart and that accumulation of ceramide contributes to cardiomyocyte apoptosis associated with type 2 diabetes and obesity. However, it remains unknown whether a similar relationship is present also in the human heart. Therefore, we aimed to examine whether myocardial apoptosis in obese and type 2 diabetic patients is associated with elevated ceramide level. The study included 11 lean and 26 overweight or moderately obese subjects without (n = 11, OWT) or with (n = 15, T2D-OWT) a history of type 2 diabetes. Samples of the right atrial appendage were obtained from patients at the time of coronary bypass surgery. Compared with lean subjects, the extent of DNA fragmentation (a marker of apoptosis) was significantly higher in the myocardium of OWT patients and increased further in T2D-OWT subjects. However, the content of ceramide and sphingoid bases remained stable. Interestingly, the mRNA level of enzymes involved in synthesis and degradation of ceramide including serine palmitoyltransferase, sphingosine kinase 1, neutral sphingomyelinase, and ceramidases was markedly higher in the myocardium of OWT and T2D-OWT patients compared with lean subjects. Our results indicate that in the human heart, or at least in the atrium, ceramide is not a major factor in cardiomyocyte apoptosis associated with obesity and type 2 diabetes. 相似文献
939.
Two-dimensional imaging of tumour control probabilities and normal tissue complication probabilities
Aim
To create a presentation method of TCP and NTCP distributions calculated based on dose distribution for a selected CT slice.Materials and methods
Three 24-bit colour maps – of dose distribution, delineated structures and CT information – were converted into m-by-n-by-3 data arrays, containing intensities of red, green, and blue colour components for each pixel. All calculations were performed with Matlab v.6.5. The transformation function, which consists of five linear functions, was prepared to translate the colour map into a one-dimensional data array of dose values. A menu-driven application based on the transformation function and mathematical models of complication risk (NTCP) and treatment control probability (TCP) was designed to allow pixel-by-pixel translation of colour maps into one-dimensional arrays of TCP and NTCP values.Results
The result of this work is an application created to visualize the TCP and NTCP distribution for a single CT scan based on the spatial dose distribution calculated in the treatment planning system. The application allows 10 targets (PTV) and 10 organs at risks (OaR) to be defined. The interface allows alpha/beta values to be inserted for each delineated structure. The application computes TCP and NTCP matrices, which are presented as colour maps superimposed on the corresponding CT slice. There is a set of parameters used for TCP/NTCP calculations which can be defined by the user.Conclusion
Our application is a prototype of an evaluation tool. Although limited to a single plane of the treatment plan, it is believed to be a starting point for further development. 相似文献940.
Marcin Hetnał Alicja Kielaszek-Ćmiel Magdalena Wolanin Stanisław Korzeniowski Piotr Brandys Krzysztof Małecki Beata Sas-Korczyńska Monika Chłosta Anna Kokoszka 《Reports of Practical Oncology and Radiotherapy》2010,15(5):113-118