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101.
102.

Background  

AP65 is a prominent adhesin of Trichomonas vaginalis that mediates binding of parasites to host vaginal epithelial cells (VECs). AP65 with no secretion signal sequence, membrane targeting peptide, and anchoring motif was recently found to be secreted.  相似文献   
103.

Background  

Inbreeding and the loss of genetic diversity are known to be significant threats to small, isolated populations. Hymenoptera represent a special case regarding the impact of inbreeding. Haplodiploidy may permit purging of deleterious recessive alleles in haploid males, meaning inbreeding depression is reduced relative to diploid species. In contrast, the impact of inbreeding may be exacerbated in Hymenopteran species that have a single-locus complementary sex determination system, due to the production of sterile or inviable diploid males. We investigated the costs of brother-sister mating in the bumblebee Bombus terrestris. We compared inbred colonies that produced diploid males and inbred colonies that did not produce diploid males with outbred colonies. Mating, hibernation and colony founding took place in the laboratory. Once colonies had produced 15 offspring they were placed in the field and left to forage under natural conditions.  相似文献   
104.

Background  

Trichomonas vaginalis is a human urogenital pathogen responsible for trichomonosis, the number-one, non-viral sexually transmitted disease (STD) worldwide, while T. tenax is a commensal of the human oral cavity, found particularly in patients with poor oral hygiene and advanced periodontal disease. The extent of genetic identity between T. vaginalis and its oral commensal counterpart is unknown.  相似文献   
105.
106.
Early origin of foraminifera suggested by SSU rRNA gene sequences   总被引:11,自引:3,他引:8  
Foraminifera are one of the largest groups of unicellular eukaryotes with probably the best known fossil record. However, the origin of foraminifera and their phylogenetic relationships with other eukaryotes are not well established. In particular, two recent reports, based on ribosomal RNA gene sequences, have reached strikingly different conclusions about foraminifera's evolutionary position within eukaryotes. Here, we present the complete small subunit (SSU) rRNA gene sequences of three species of foraminifera. Phylogenetic analysis of these sequences indicates that they branch very deeply in the eukaryotic evolutionary tree: later than those of the amitochondrial Archezoa, but earlier than those of the Euglenozoa and other mitochondria-bearing phyla. Foraminifera are clearly among the earliest eukaryotes with mitochondria, but because of the peculiar nature of their SSU genes we cannot be certain that they diverged first, as our data suggest.   相似文献   
107.
108.
Transferrin, a glycoprotein involved in iron transport in body fluids, was isolated from amniotic fluid of a hydramniospatient by sequential anion-exchange chromatography and gel filtration. The N-glycans of human amniotic fluid transferrin (hAFT) were enzymatically liberated by PNGase-F digestion, isolated by gel filtration and fractionated by (high-pH) anion-exchange chromatography. After alkaline borohydride treatment of native hAFT, the released O-glycans were isolated by gel filtration and fractionated by anion-exchange chroma-tography. Structure elucidation of 14 N- and 2 O-glycans was performed by 500 or 600 MHz1H-NMR spectroscopy. Besides conventional N-glycans established earlier for human serum transferrin (hST), new (alpha1-3)-fucosylated N- glycans were found, representing sialyl Le(x) elements. Furthermore, as compared to hST, a higher degree of (alpha1-6)-fucosylation and an increase in branching from di- to triantennary compounds has been detected. The presence of O-glycans is demonstrated for the first time in transferrin.   相似文献   
109.
A male cause is responsible in near 50% of infertilities. The radiologist takes place in a multidisciplinary management, after clinical and biological screening, which distinguishes:
  • - excretory infertilities, of which some causes are curable. Transrectal sonography (TRUS) and scrotal sonography are the first tests. In case of epididymal obstacle, scrotal abnormalities may correspond to constitutional or acquired causes; TRUS is normal. TRUS usually identifies congenital bilateral absence of vas deferens; without renal agenesia, a genital form of cystic fibrosis must be evocated. In case of distal obstacles, TRUS may be completed with MRI, especially in case of voluminous cystic tumors. Vasography, which directly shows was deferens patency, is required to accurately diagnose obstruction when ultrasound is not conclusive; vasography must be integrated in a surgical strategy.
  • - secretory azoospermies, from gonadic or hypothalamo-hypophyseal causes. Scrotal sonography may complete clinical examination. When hypothalamo-hypophyseal axis must be explored, MRI is the reference test.
  • - oligo-astheno-teratospermies, where infertilities are often mixed, with various male factors.
  • Three groups must be explored: hyperprolactinemies (MRI); chronic genital infection (ultrasound); varicoceles; Doppler color ultrasound may help to the detection; spermatic phlebography produce a pretherapeutic cartography, and may be the first step of a percutaneous sclerotherapy.  相似文献   
    110.
    SCH 58261 is a reported adenosine A2A receptor antagonist, which is active in rat in vivo models of Parkinson’s Disease upon ip administration. However, it has poor selectivity versus the A1 receptor and does not demonstrate oral activity. We report the design and synthesis of biaryl and heteroaryl analogs of SCH 58261 which improve the A2A receptor binding selectivity as well as the pharmacokinetic properties of SCH 58261. In particular, the quinoline 25 has excellent A2A receptor in vitro binding affinity and selectivity, sustained rat plasma levels upon oral dosing, and is active orally in a rat behavioral assay.  相似文献   
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