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171.
Babesiosis, recognized since ancient times as an important disease of livestock and more recently as an emerging disease in dogs worldwide, is caused by intraerythrocytic protozoa of the genus Babesia and is transmitted by ticks. The pathophysiology of canine babesiosis has been extensively studied but many questions remain unanswered, especially regarding the diversity of disease manifestations in different European countries. Continued investigation of the similarities and differences in host-parasite interplay in canine babesiosis in different European countries should lead to a better understanding of the disease process, potentially leading to better prediction of disease outcome and the development of new treatment modalities. From the European point of view it is important to conduct these studies on Babesia canis.  相似文献   
172.
173.
The structural basis of water permeation and proton exclusion in aquaporins   总被引:2,自引:0,他引:2  
Fu D  Lu M 《Molecular membrane biology》2007,24(5-6):366-374
Aquaporins (AQPs) represent a ubiquitous class of integral membrane proteins that play critical roles in cellular osmoregulations in microbes, plants and mammals. AQPs primarily function as water-conducting channels, whereas members of a sub-class of AQPs, termed aquaglyceroporins, are permeable to small neutral solutes such as glycerol. While AQPs facilitate transmembrane permeation of water and/or small neutral solutes, they preclude the conduction of protons. Consequently, openings of AQP channels allow rapid water diffusion down an osmotic gradient without dissipating electrochemical potentials. Molecular structures of AQPs portray unique features that define the two central functions of AQP channels: effective water permeation and strict proton exclusion. This review describes AQP structures known to date and discusses the mechanisms underlying water permeation, proton exclusion and water permeability regulation.  相似文献   
174.
We report on a series of alpha-substituted-beta-tetralin-derived and related phenethyl-based isoquinolinyl and hydroxynaphthyl ureas as potent antagonists of the human TRPV1 receptor. The synthesis and Structure-activity relationships (SAR) of the series are described.  相似文献   
175.
The purpose of the present work was to evaluate the iron bioavailability of a new ferric pyrophosphate salt stabilized and solubilized with glycine. The prophylactic–preventive test in rats, using ferrous sulfate as the reference standard, was applied as the evaluating methodology both using water and yogurt as vehicles. Fifty female Sprague–Dawley rats weaned were randomized into five different groups (group 1: FeSO4; group 2: pyr; group 3: FeSO4 + yogurt; group 4: pyr + yogurt and group 5: control). The iron bioavailability (BioFe) of each compound was calculated using the formula proposed by Dutra-de-Oliveira et al. where BioFe % = (HbFef − HbFei) × 100/ToFeIn. Finally, the iron bioavailability results of each iron source were also given as relative biological value (RBV) using ferrous sulfate as the reference standard. The results showed that both BioFe % and RBV % of the new iron source tested is similar to that of the reference standard independently of the vehicle employed for the fortification procedure (FeSO4 49.46 ± 12.0% and 100%; Pyr 52.66 ± 15.02% and 106%; FeSO4 + yogurth 54.39 ± 13.92% and 110%; Pyr + yogurt 61.97 ± 13.54% and 125%; Control 25.30 ± 6.60, p < 0.05). Therefore, the stabilized and soluble ferric pyrophosphate may be considered as an optimal iron source for food fortification.  相似文献   
176.
Using a 'directed' iodination procedure, novel iodo-resiniferatoxin congeners were synthesized from 4-acetoxy-3-methoxyphenylacetic acid and resiniferinol- 9,13,14-ortho-phenylacetate (ROPA). The 2-iodo-4-hydroxy-5-methoxyphenylacetic acid ester of resiniferinol 5 displayed high affinity binding (K(i)=0.71 nM) for the human vanilloid VR1 receptor and functioned as a partial agonist.  相似文献   
177.
[3a,4,5,9b-Tetrahydro-1H-benzo[e]indol-2-yl]amines were prepared via reductive amination and concomitant cyclization of alpha-cyanomethyl-beta-aminotetralins. N-acylation with omega-sulfonamido-carboxylic acids and subsequent reduction afforded a series of N-(sulfonamido)alkyl[tetrahydro-1H-benzo[e]indol-2-yl]amines, which bound to the human neuropeptide Y Y5 receptor with nanomolar affinity.  相似文献   
178.
In this research, we measured the iron bioavailability of ferrous gluconate stabilized with glycine (SFG) when it is used to fortify petit suisse cheese using the prophylactic-preventive method in rats. Three groups of male, weaned rats received a basal diet (control diet; 5.2 ppm Fe), a reference standard diet (SO4Fe; 9.2 ppm Fe), and a basal diet using iron-fortified petit suisse cheese as the iron source (cheese diet; 8.8 ppm Fe) for 22d. The iron bioavailability was calculated as the ratio between the mass of iron incorporated into hemoglobin and the total iron intake per animal during the treatment. These values (BioFe) were 68% and 72% for SFG and ferrous sulfate, respectively. The value of the Relative Biological Value (RBV) was 95% for SFG in petit suisse cheese. These results show that according to this method, the iron bioavailability from industrial fortified petit suisse cheese can be considered as a high bioavailability rate.  相似文献   
179.
Ferritin is a ubiquitously distributed iron-binding protein. Cell culture studies have demonstrated that ferritin plays a role in maintenance of iron homoeostasis and in the protection against cytokine- and oxidant-induced stress. To test whether FerH (ferritin H) can regulate tissue iron homoeostasis in vivo, we prepared transgenic mice that conditionally express FerH and EGFP (enhanced green fluorescent protein) from a bicistronic tetracycline-inducible promoter. Two transgenic models were explored. In the first, the FerH and EGFP transgenes were controlled by the tTA(CMV) (Tet-OFF) (where tTA and CMV are tet transactivator protein and cytomegalovirus respectively). In skeletal muscle of mice bearing the FerH/EGFP and tTA(CMV) transgenes, FerH expression was increased 6.0+/-1.1-fold (mean+/-S.D.) compared with controls. In the second model, the FerH/EGFP transgenes were controlled by an optimized Tet-ON transactivator, rtTA2(S)-S2(LAP) (where rtTA is reverse tTA and LAP is liver activator protein), resulting in expression predominantly in the kidney and liver. In mice expressing these transgenes, doxycycline induced FerH in the kidney by 14.2+/-4.8-fold (mean+/-S.D.). Notably, increases in ferritin in overexpressers versus control littermates were accompanied by an elevation of IRP (iron regulatory protein) activity of 2.3+/-0.9-fold (mean+/-S.D.), concurrent with a 4.5+/-2.1-fold (mean+/-S.D.) increase in transferrin receptor, indicating that overexpression of FerH is sufficient to elicit a phenotype of iron depletion. These results demonstrate that FerH not only responds to changes in tissue iron (its classic role), but can actively regulate overall tissue iron balance.  相似文献   
180.
During the floral transition the shoot apical meristem changes its identity from a vegetative to an inflorescence state. This change in identity can be promoted by external signals, such as inductive photoperiod conditions or vernalization, and is accompanied by changes in expression of key developmental genes. The change in meristem identity is usually not reversible, even if the inductive signal occurs only transiently. This implies that at least some of the key genes must possess an intrinsic memory of the newly acquired expression state that ensures irreversibility of the process. In this review, we discuss different molecular scenarios that may underlie a molecular memory of gene expression.  相似文献   
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