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251.
Distribution of neurones detectable with antisera to the corazonin (Crz) and the pigment-dispersing factor (PDF) was mapped in the workers or pseudergates of 10 species representing six out of seven termite families. All species contained two triads of Crz-immunoreactive (Crz-ir) neurones in the protocerebrum. Their fibres were linked to the opposite hemisphere, formed a network in the fronto-lateral protocerebrum, and projected to the corpora cardiaca (CC); in most species the fibres also supplied the deuto- and tritocerebrum and the frontal ganglion. Some species possessed additional Crz-ir perikarya in the protocerebrum and the suboesophageal ganglion (SOG). The PDF-ir somata were primarily located in the optic lobe (OL) and SOG. OL harboured a group (3 groups in Coptotermes) of 2-6 PDF-ir cells with processes extending to the medulla, connecting to the contralateral OL, forming 1-2 networks in the protocerebrum, and in most species running also to CC. Such a PDF-ir system associated with the OL was missing in Reticulitermes. Except for Mastotermes, the termites contained 1-2 PDF-ir cell pairs in the SOG and two species had additional perikarya in the protocerebrum. The results are consistent with the view of a monophyletic termite origin and demonstrate how the Crz-ir and PDF-ir systems diversified in the course of termite phylogeny.  相似文献   
252.
Recombinant Escherichia coli cells expressing eight Baeyer-Villiger monooxygenases of bacterial origin have been utilized to oxidize prochiral heterocyclic ketones containing a pyran ring system. Within the biotransformation, two stereogenic centers were introduced with high control of enantioselectivity. The chemoselectivity of the enzymatic reaction was found to be high in favor of the Baeyer-Villiger process when using substituted ketone precursors incorporating functional groups labile to oxidation. A significantly different behavior was observed for two groups of monooxygenases with respect to substrate acceptance, which is consistent with our previous classification into two enzyme clusters.  相似文献   
253.
Arnold JN  Saldova R  Hamid UM  Rudd PM 《Proteomics》2008,8(16):3284-3293
The identification of serum biomarkers has lead to improvements in the detection and diagnosis of cancer, and combinations of these biomarkers have increased further their sensitivity and specificity. Glycosylation is the most common PTM of secreted proteins and the identification of novel serum glyco-biomarkers has become a topic of increasing interest because the glycan processing pathways are frequently disturbed in cancer cells. A future goal is to combine current biomarkers with glyco-biomarkers to yield further improvements. Well characterised N-glycosylation changes in the serum glycome of cancer patients include changes in the levels of tri- and tetra-antennary glycan structures, sialyl Lewis X epitopes and agalactosylated bi-antennary glycans. Several of these glycosylated markers have been linked to chronic inflammatory diseases, promoting questions about the links between inflammation and cancer. In this review, the glycoproteins which display these glycan epitopes, the glycosyl transferases which can generate them, their potential functions and their use as biomarkers are evaluated.  相似文献   
254.
Insulin resistance and obesity are very frequent disorders and are described as the dominant risk factors for cardiovascular disease. The aim of this study was to analyze the interrelations between several metabolic variables (including TNF-alpha) and factors related to insulin resistance in groups of both normal and hyperlipidemic postmenopausal women and men of appropriate age, and to attempt to elucidate the gender differences. The study was carried out on 70 out-patients of the Metabolic Center. From these, 40 patients (20 men and 20 women) were selected with mild hyperlipidemia. Two other groups (10 men and 20 women) with approximately normal serum lipids parameters were taken as "controls". In hyperlipidemic women the mean serum concentration of the TNF-alpha was no different from that in the control group in spite of the fact that values of HOMA IR, insulin, proinsulin and lipid parameters increased significantly. In hyperlipidemic men we have found the decrease in TNF-alpha in comparison with the control group. In all four groups the statistical analysis showed correlations between metabolic parameters (including TNF-alpha) and parameters related to insulin resistance. Also differences in relation to the gender have been found. Multiple regression analysis demonstrated the important role of TNF-alpha in the regulation of both the insulin resistance and in the secretion of insulin in women. In men, BMI and HDL-cholesterol played a dominant role, while the role of TNF-alpha seemed to be minimal.  相似文献   
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256.
The anti-arrhythmic effect was tested on the model of aconitine-induced arrhythmia. The experiment was performed in vivo with 31 male Wistar laboratory rats. Group A was first administered aconitine and, after the onset of the first sinus rhythm disorders, the 44Bu compound was administered. Group B was first administered the 44Bu compound and only after that the aconitine. The control group was administered aconitine and saline as a replacement of the tested compound. In group A, there was a decrease in the ventricular fibrillation occurrence from 100 % to 8 % (p < 0.001) after the administration of the 44Bu compound. In the B group, the onsets of all monitored arrhythmia types were delayed by an average of 15.6 min. Ventricular rhythm occurrence was decreased from 100 to 20 %, as well as ventricular fibrillations, from 100 to 0 % (p < 0.001).  相似文献   
257.
Ribozymes are catalytically active RNA molecules that cleave other RNA molecules in a sequence-specific fashion, with significant turnover. The successful design and synthesis of ribozymes with modifications to increase their stability in biological fluids, while maintaining catalytic activity, has been instrumental in moving this technology from the laboratory into clinical trials. With the entry of ribozymes into the clinical setting, the need has arisen for reagents and/or assays to detect these drugs in tissues. We have developed a monoclonal antibody to the 2(')-deoxy-2(')-C-allyl uridine modification present in our synthetic hammerhead ribozymes. The monoclonal antibody, termed CA1USR, is a murine IgG1(k), whose epitope appears to involve both the 2(')-C-allyl modification, and the uridine base. Use of CA1USR for immunohistochemical detection of ribozymes in the tissues of mice which were administered two structurally different ribozymes has demonstrated its utility as a reagent for in vivo localization of ribozymes containing the 2(')-C-allyl uridine modification.  相似文献   
258.
Extracts from mycorrhizal roots, non-mycorrhizal roots obtained from mycorrhizal root systems, and non-inoculated maize roots were fractionated by gel chromatography and their effects on the hyphal growth of arbuscular mycorrhizal fungusGlomus intraradices were studied under aseptic conditions. Low-molecular (MW lower than 3000) extracts obtained from mycorrhizal roots contained the fraction that most rapidly suppresses the hyphae growth. This was not observed for the fastest fraction obtained from non-mycorrhizal roots. The increased content of some inorganic ions, mainly potassium, was recorded in the fastest fraction of the mycorrhizal root extracts. At the same time, higher contents of two unidentified major organic compounds were revealed in this fraction of the mycorrhizal root extract compared to the non-mycorrhizal one. Some of these compounds, which are locally accumulated in the mycorrhizal parts of the root, are probably responsible for the effect observed. Potassium alone, even at a high concentration, cannot be responsible for the supression observed.  相似文献   
259.
260.
Ribosomal DNA (rDNA) loci encoding 5S and 45S (18S-5.8S-28S) rRNAs are important components of eukaryotic chromosomes. Here, we set up the animal rDNA database containing cytogenetic information about these loci in 1343 animal species (264 families) collected from 542 publications. The data are based on in situ hybridisation studies (both radioactive and fluorescent) carried out in major groups of vertebrates (fish, reptiles, amphibians, birds, and mammals) and invertebrates (mostly insects and mollusks). The database is accessible online at www.animalrdnadatabase.com. The median number of 45S and 5S sites was close to two per diploid chromosome set for both rDNAs despite large variation (1–74 for 5S and 1–54 for 45S sites). No significant correlation between the number of 5S and 45S rDNA loci was observed, suggesting that their distribution and amplification across the chromosomes follow independent evolutionary trajectories. Each group, irrespective of taxonomic classification, contained rDNA sites at any chromosome location. However, the distal and pericentromeric positions were the most prevalent (>?75% karyotypes) for 45S loci, while the position of 5S loci was more variable. We also examined potential relationships between molecular attributes of rDNA (homogenisation and expression) and cytogenetic parameters such as rDNA positions, chromosome number, and morphology.  相似文献   
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