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921.
922.
Dilly OC Anumba Saad El Gelany Sarah L Elliott Tin C Li 《Reproductive biology and endocrinology : RB&E》2010,8(1):62
Background
We have recently shown that serum relaxin-2 levels are attenuated in women with a history of recurrent pregnancy loss (RPL). We sought to determine whether a history of RPL is also associated with changes in serum matrix metalloproteases (MMPs) and tissue inhibitors of matrix metalloproteases (TIMP) -1 and -2. 相似文献923.
Crude liver membrane fractions as substrate preserve liver-specific functions in long-term,serum-free rat hepatocyte cultures 总被引:1,自引:0,他引:1
Bashar Saad Hanspeter Schawalder Peter Maier 《In vitro cellular & developmental biology. Animal》1993,29(1):32-40
Summary Over time, rat hepatocytes cultured on collagen lose the capacity to express liver-specific functions. The influence on this
degradation process of an alternative substratum—crude membrane fractions prepared from the liver of the same rat strain—was
investigated. Freshly isolated rat hepatocytes were cultured in serum-free Williams E medium supplemented with aprotinin,
selenium, dexamethasone, and insulin in flasks coated with a mixture of rat liver crude membrane fractions:collagen type I
(100:1). The cells adhered firmly, exhibiting minimal spreading and remaining grouped in columns or in cell islands, and retained
their liver-specific functions for more than 1 wk. Hepatocytes secreted substantially higher amounts of albumin than cells
cultured on collagen-coated dishes, and on Days 1 and 9 in culture the total P-450 content was 72 and 40%, respectively, of
that of freshly isolated cells. On Day 6, the 7-ethoxyresorufin-O-de-ethylase and the aldrin epoxidase activities were still more than 50% that of freshly isolated hepatocytes. Exposure to
phenobarbital on Days 3 to 6 increased the total cytochrome P-450 content twofold; exposure to 3-methylcholanthrene increased
the activity of the corresponding cytochrome P-450 isoforms to 20 times that observed in untreated cultures and 6 times that
observed in freshly isolated cells. Thus, given the ease with which they are prepared, the use of crude membrane fractions
combined with culture medium supplemented with aprotinin and selenium can facilitate the preparation of reproducible cultures
suitable for long-term in vitro pharmacotoxicologic studies using rat hepatocytes. 相似文献
924.
Federico Galvagni Fawzy A. Saad Gian Antonio Danieli Marta Miorin Libero Vitiello Maria Luisa Mostacciuolo Corrado Angelini 《Human genetics》1994,94(1):83-87
Starting from a group of 265 Italian patients affected with Duchenne or Becker muscular dystrophy a screening for duplications in the dystrophin gene was performed on 112 cases in which no deletions had previously been detected. The 21 intragenic duplications detected account for 7.9% of the total. Among these, one duplication including exons from 3 to 43 is the largest reported so far. Data from this study were combined with those from the literature and breakpoint distribution by intron was analysed. In general breakpoints occur mostly in the proximal third of the gene, in particular in intron 7. However, both the frequency of duplications and the distribution of breakpoints by intron are different in the Japanese sample compared with the other groups of patients. The role of geographical differentiation of intron sequences by genetic drift and of transposon-like sequences in explaining these differences is discussed. 相似文献
925.
Pierre I. Gumowski Bernard Clot Alain Davet Saad Saad Hélène Hassler Sylvie Dunoyer-Geindre 《Aerobiologia》2000,16(1):83-86
Hornbeam (Carpinus sp.) flowering occurs generallysimultaneously with birch anthesis. While birch pollenis known as the major tree-allergen in central andnorthern Europe, the quantitative and qualitative roleof hornbeam pollen in allergy has not been evaluated.In some regions of Switzerland, the annual ratiohornbeam SPI / birch SPI reaches 20–30% on average,and 50–180% some years. The relative importance ofhornbeam pollen hypersensitivity has been evaluated inmore than 200 patients suffering from spring allergiesto pollen during the last five years (1993–1997) inthe region of Geneva. Among symptomatic patientsduring the March-April period, 73.5% werehypersensitive to Betulaceae pollen. Overall, 71.7%of the patients allergic to Betulaceae pollen werefound to be sensitive to hornbeam, and 12.5% of thesame group of patients were sensitive to hornbeampollen only. Among this last group, half of thepatients, besides allergic rhino-conjunctivitis, werealso suffering from asthma. Hornbeam pollen isabundant and appears to have a significativeimportance in spring allergies. In some cases,specific immunotherapy to hornbeam pollen shouldperhaps be considered. 相似文献
926.
Mona Saad Binkadem Huda Salem AlSalem Soha Talal Al-Goul Mohamed A. El Hamd Mohamed Oraby Faten M. Ali Zainy Mohamed A. Abdel-Lateef 《Luminescence》2023,38(10):1836-1843
Naftidrofuryl is a vasodilator medication used for treating cerebral and peripheral vascular diseases. In this study, two spectroscopical techniques, spectrofluorimetric and resonance Rayleigh scattering (RRS), were utilized to quantify naftidrofuryl in its pharmaceutical samples. The developed methodologies in this study rely on a facile process of forming an association complex between erythrosine B reagent and naftidrofuryl under acidic conditions. The fluorimetric assay is based on the ability of naftidrofuryl to quench and decrease the native fluorescence intensity of the reagent when measured at = 550 nm ( = 526 nm). Under similar reaction conditions, the RRS method relies on the observed amplification in the RRS spectrum of the reagent at a wavelength of 577 nm following its interaction with naftidrofuryl. The methods exhibited linearity within the ranges 0.2–1.6 μg/ml (r2 = 0.999) and 0.1–1.4 μg/ml (r2 = 0.9994), with limit of quantitation values of 0.146 and 0.099 μg/ml, and limit of detection values of 0.048 and 0.032 μg/ml, for the fluorometric and the RRS methods, respectively. Moreover, the quenching between the dye and naftidrofuryl was studied using Stern–Volmer analysis, and the methodologies were experimentally optimized and validated. Additionally, acceptable recoveries were achieved when the procedures were applied to determine naftidrofuryl in pharmaceutical samples. 相似文献
927.
Mneimneh Saad 《IEEE/ACM transactions on computational biology and bioinformatics / IEEE, ACM》2009,6(4):682-688
The interaction of two RNA molecules is a common mechanism for many biological processes. Small interfering RNAs represent a simple example of such an interaction. But other more elaborate instances of RNA-RNA interaction exist. Therefore, algorithms that predict the structure of the RNA complex thus formed are of great interest. Most of the proposed algorithms are based on dynamic programming. RNA-RNA interaction is generally NP-complete; therefore, these algorithms (and other polynomial time algorithms for that matter) are not expected to produce optimal structures. Our goal is to characterize this suboptimality. We demonstrate the existence of constant factor approximation algorithms that are based on dynamic programming. In particular, we describe 1/2 and 2/3 factor approximation algorithms. We define an entangler and prove that 2/3 is a theoretical upper bound on the approximation factor of algorithms that produce entangler-free solutions, e.g., the mentioned dynamic programming algorithms. 相似文献
928.
The polymerase chain reaction (PCR) has the potential to detect low levels of the human pathogen Escherichia coli O157 : H7 in bovine faeces. To improve the utility of PCR for this application, several methods for preparing template DNA from bovine faeces, both directly and after non-selective enrichment, were tested. These were boiling, enzyme treatment, enzyme treatment plus phenol-chloroform extraction, and enzyme treatment plus phenol-chloroform extraction plus Geneclean® purification. Of these, the boiling method was the most consistent and had a sensitivity of approximately 3 cfu g−1 faeces, with an assay time of less than 32 h. The boiling method was also combined with immunomagnetic separation (IMS) to detect E. coli O157 : H7 in less than 8 h, but with a sensitivity of approximately 103 cfu g−1 faeces. These methods can be used to prepare template for PCR screening of bovine faeces using any appropriate PCR primers. 相似文献
929.
The spleen of Agama stellio is composed mainly of red pulp; the white pulp is poorly developed, and its clusters are scattered throughout the organ and contain lymphocytes, reticular cells, and some plasma cells. The red pulp consists of clear reticular cells intermingled with blood cells, sinusoids, and pigment cells. The spleen of Chalcides ocellatus is encapsulated by connective tissue and is composed of white and red pulp. The white pulp consists of lymphoid tissue that surrounds the central arterioles, forming the periarteriolar lymphocyte sheath (PALS). The red pulp is composed of a system of venous sinuses and cords. The results of various histochemical procedures designed to demonstrate mucosubstances, proteins, and nucleic acids indicate that the spleen in these species resembles the mammalian spleen. © 1993 Wiley-Liss, Inc. 相似文献
930.