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81.
82.
Expression of N-linked sialyl Le(x) determinants and O-glycans in the carbohydrate moiety of human amniotic fluid transferrin during pregnancy 总被引:3,自引:0,他引:3
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
83.
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
84.
Quezada-Rivera JJ RE Soria-Guerra FS Pérez-Juárez L Martínez-González SE Valdés- Rodríguez NL Vasco-Méndez JF Morales-Domínguez 《Phyton》2019,88(1):25-35
The use of antimicrobial peptides (AMPs) synthesized
by bacteria (bacteriocins) is an alternative for combating multidrug
resistant bacterial strains and their production by recombinant route
is a viable option for their mass production. The bacteriocin E-760
isolated from the genus Enterococcus sp. has been shown to possess
inhibitory activity against Gram-negative and Gram-positive
bacteria. In this study, the expression of a chimeric protein coding
for E-760 in the nucleus of C. reinhardtii was evaluated, as well as,
its antibacterial activity. The synthetic gene E-760S was inserted
into the genome of C. reinhardtii using Agrobacterium tumefaciens.
A transgenic line was identified in TAP medium with hygromycin
and also by PCR. The increment in the culture medium temperature
of the transgenic strain at 35 °C for 10 minutes, increased the
production level of the recombinant protein from 0.14 (Noninduced
culture, NIC) to 0.36% (Induced culture, IC) of total soluble
proteins (TSP); this was quantified by an ELISA assay. Recombinant
E-760 possesses activity against Staphylococcus aureus in 0.34 U
log, Streptococcus agalactiae in 0.48 U log, Enterococcus faecium in
0.36 U log, Pseudomonas aeruginosa in 2 U log and for Klebsiella
pneumoniae, the activity was 0.07 U log. These results demonstrate
that the nucleus transformation of C. reinhardtii can function as
a stable expression platform for the production of the synthetic
gene E-760 and it can potentially be used as an antibacterial agent. 相似文献
85.
86.
Active transportation to school over 2 years in relation to weight status and physical activity 总被引:1,自引:0,他引:1
Rosenberg DE Sallis JF Conway TL Cain KL McKenzie TL 《Obesity (Silver Spring, Md.)》2006,14(10):1771-1776
Objective: To prospectively examine potential benefits of active commuting to school on measures of weight status and physical activity in a sample of youth. Research Methods and Procedures: A cohort of students from seven elementary schools was measured four times—in the fall and spring of fourth grade (N = 1083) and fifth grade (N = 924). Participants were classified as active (walking, biking, or skateboarding to school almost every day for baseline analyses or at least 2 d/wk for analyses of consistent active commuting) or non‐active commuters to school. Accelerometers were used to measure physical activity. Height, weight, and skinfolds were objectively assessed. Results: Boys who actively commuted to school had lower BMI (p < 0.01) and skinfolds (p < 0.05) than non‐active commuters to school in the fourth grade. Active commuting to school over 2 years was not associated with BMI change or overweight status. Discussion: Walking and cycling to school may contribute to preventing excessive weight gain, or leaner children may walk or cycle to school. 相似文献
87.
Penelope R Whitehorn Matthew C Tinsley Mark JF Brown Ben Darvill Dave Goulson 《BMC evolutionary biology》2009,9(1):152-9
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88.
Kevin?WhittingstallEmail author Gerhard?Stroink Larry?Gates JF?Connolly Allen?Finley 《Biomedical engineering online》2003,2(1):14
Background
The electroencephalogram (EEG) reflects the electrical activity in the brain on the surface of scalp. A major challenge in this field is the localization of sources in the brain responsible for eliciting the EEG signal measured at the scalp. In order to estimate the location of these sources, one must correctly model the sources, i.e., dipoles, as well as the volume conductor in which the resulting currents flow. In this study, we investigate the effects of dipole depth and orientation on source localization with varying sets of simulated random noise in 4 realistic head models. 相似文献89.
Oliver Beckstein Ekaterina Ivanova Tian Geng Simone Weyand David Drew Joseph Lanigan David J Sharples Mark SP Sansom So Iwata Colin WG Fishwick A Peter Johnson Alexander D Cameron Peter JF Henderson 《The EMBO journal》2014,33(16):1831-1844
The hydantoin transporter Mhp1 is a sodium‐coupled secondary active transport protein of the nucleobase‐cation‐symport family and a member of the widespread 5‐helix inverted repeat superfamily of transporters. The structure of Mhp1 was previously solved in three different conformations providing insight into the molecular basis of the alternating access mechanism. Here, we elucidate detailed events of substrate binding, through a combination of crystallography, molecular dynamics, site‐directed mutagenesis, biochemical/biophysical assays, and the design and synthesis of novel ligands. We show precisely where 5‐substituted hydantoin substrates bind in an extended configuration at the interface of the bundle and hash domains. They are recognised through hydrogen bonds to the hydantoin moiety and the complementarity of the 5‐substituent for a hydrophobic pocket in the protein. Furthermore, we describe a novel structure of an intermediate state of the protein with the external thin gate locked open by an inhibitor, 5‐(2‐naphthylmethyl)‐L‐hydantoin, which becomes a substrate when leucine 363 is changed to an alanine. We deduce the molecular events that underlie acquisition and transport of a ligand by Mhp1. 相似文献
90.
Helen A Arcuri Geraldo FD Zafalon Evandro A Marucci Carlos E Bonalumi Nelson JF da Silveira José M Machado Walter F de AzevedoJr Mário S Palma 《BMC bioinformatics》2010,11(1):12