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Wyświetlanie 1-4 z 4
Tytuł:
Small intestine bacterial overgrowth is frequent in cystic fibrosis: combined hydrogen and methane measurements are required for its detection
Autorzy:
Lisowska, Aleksandra
Wójtowicz, Jerzy
Walkowiak, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/1040476.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cystic fibrosis
small intestine bacterial overgrowth
breath test
hydrogen
methane
Opis:
Introduction: Hydrogen breath test (BT) is commonly used as a diagnostic tool for the detection of small intestine bacterial overgrowth (SIBO). It was reported that colonic methane production is far more frequent in cystic fibrosis (CF) patients than in other subjects. Therefore, measuring exclusively hydrogen in the diagnostic breath test for diagnosing SIBO might be of limited value. We aimed to assess the usefulness of combined measurement of hydrogen and methane expiration for the diagnosis of SIBO in CF. Material and Methods: The study comprised 62 CF patients aged 5 to 18 years. Three-hundred-ninety subjects assessed due to gastrointestinal symptoms for the presence of SIBO served as a comparative group. In all subjects hydrogen/methane BT using glucose was performed. A positive BT was defined as fasting hydrogen ≥ 20 ppm or fasting methane ≥ 10 ppm or a rise of ≥ 12 ppm hydrogen or ≥ 6 ppm methane over baseline during the test. Results: In 23 (37.1%) CF patients and in 52 (13.3%) subjects from the comparative group abnormal BT results were found. In seven (11.3%) CF patients and 29 (7.4%) of the other subjects studied methane measurement allowed diagnosis of SIBO. Conclusions: Small intestine bacterial overgrowth is frequent in cystic fibrosis. For its detection in cystic fibrosis and other gastrointestinal patients, combined hydrogen and methane measurement instead of hydrogen breath test should be applied. Without the additional measurement of methane a significant percentage of SIBO will be missed.
Źródło:
Acta Biochimica Polonica; 2009, 56, 4; 631-634
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
5'-Esters of 2'-deoxyadenosine and 2-chloro-2'-deoxyadenosine with cell differentiation-provoking agents.
Autorzy:
Grieb, Paweł
Kryczka, Tomasz
Wójtowicz, Radosław
Kawiak, Jerzy
Kazimierczuk, Zygmunt
Powiązania:
https://bibliotekanauki.pl/articles/1043818.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cladribine
phenylacetate
all-trans-retinoic acid
2'-deoxyadenosine
nucleoside esters
13-cis-retinoic acid
Opis:
Phenylacetic and retinoic acids are carboxyacidic cell differentiating agents displaying anticancer activities. We report on a new class of compounds including the 5'-esters of 2'-deoxyadenosine (dA) or 2-chloro-2'-deoxyadenosine (cladribine, 2CdA) and the aforementioned acids. The rationale behind the synthesis of these esters was that if they are hydrolyzed inside the lymphoid cells, either dA will be removed from the intracellular environment by deamination, or 2CdA will be phosphorylated and accumulated. In either case targetted delivery of the differentiating agent to the lymphoid cells may be envisaged. The said compounds were synthesized by the Mitsunobu procedure employing triphenylphosphine and azadicarboxylic acid esters, and their stability was tested against various esterases. Esters of dA and 2CdA with phenylacetic acids were found to be resistant to enzymatic hydrolysis, whereas those with retinoic acids were efficiently hydrolyzed by commercially available hepatic esterase as well as by esterases present in the blood plasma and in diluted human lymphocyte lysate. Susceptibility to enzymatic hydrolysis was found to be a prerequisite of cytotoxic and/or differentiating activity of these esters in leukemic cell lines.
Źródło:
Acta Biochimica Polonica; 2002, 49, 1; 129-137
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetospectroscopy of CdTe/Cd₁-xMgxTe modulation-doped quantum wells in THz and visible range
Autorzy:
Łusakowski, Jerzy
Zaremba, Maciej
Siemaszko, Adam
Karpierz, Krzysztof
Adamus, Zbigniew
Wojtowicz, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/2204169.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
terahertz spectroscopy
optically detected cyclotron resonance
modulation-doped CdTe quantum wells
Opis:
Transport, photoluminescence, THz transmission, and optically detected cyclotron resonance studies were carried out on samples with a single modulation-doped CdTe/Cd1-xMgxTe quantum well. THz experiments were performed at liquid helium temperatures for photon energies between about 0.5 meV and 3.5 meV. An effective mass of electron was determined to be (0.1020 ± 0.0003)m₀. Observed photoluminescence and optically detected cyclotron resonance spectra cannot be explained within the simple model of Landau quantization of parabolic bands.
Źródło:
Opto-Electronics Review; 2023, 31, 2; art. no. e144597
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Terahertz response of CdTe/Cd1-xMgxTe modulation-doped multiple quantum wells
Autorzy:
Łusakowski, Jerzy
Frączak, Andrzej
Grymuza, Mikołaj
Imos, Eryk
Siemaszko, Adam
Solarska, Wiktoria
Woyciechowska, Aniela
Zaremba, Maciej
Zdunek, Rafał
Karpierz, Krzysztof
Adamus, Zbigniew
Słupiński, Tomasz
Wojtowicz, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/2204183.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
terahertz spectroscopy
Shubnikov-de Haas oscillations
modulation-doped multiple CdTe-based quantum wells
Opis:
Terahertz (THz) transmission, photoresistance, and electrical conductivity experiments were carried out at 4.2 K on a sample with modulation-doped CdTe/Cd1-xMgxTe multiple quantum wells. The measurements were carried out as a function of a magnetic field up to 9 T and a radiation frequency between 0.1 and 0.66 THz. A broad minimum in the transmission curve was observed at magnetic fields corresponding to the cyclotron resonance at given THz frequency which was followed at larger fields by an oscillatory signal, periodic in ˉˡ. Shubnikov-de Haas oscillations were observed in magnetoconductivity and in photoresistance. Each of these experimental signals revealed the same electron concentration equal to (1.01 ± 0.03) ∙10ˡ² cmˉ². THz spectroscopy results are compared with data obtained on a single quantum well and are discussed from the point of view of using such multiple quantum wells as THz optical elements.
Źródło:
Opto-Electronics Review; 2023, 31, 2; art. no. e144600
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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