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51.
Susana Fuentes Els van Nood Sebastian Tims Ineke Heikamp-de Jong Cajo JF ter Braak Josbert J Keller Erwin G Zoetendal Willem M de Vos 《The ISME journal》2014,8(8):1621-1633
Recurrent Clostridium difficile infection (CDI) can be effectively treated by infusion of a healthy donor faeces suspension. However, it is unclear what factors determine treatment efficacy. By using a phylogenetic microarray platform, we assessed composition, diversity and dynamics of faecal microbiota before, after and during follow-up of the transplantation from a healthy donor to different patients, to elucidate the mechanism of action of faecal infusion. Global composition and network analysis of the microbiota was performed in faecal samples from nine patients with recurrent CDI. Analyses were performed before and after duodenal donor faeces infusion, and during a follow-up of 10 weeks. The microbiota data were compared with that of the healthy donors. All patients successfully recovered. Their intestinal microbiota changed from a low-diversity diseased state, dominated by Proteobacteria and Bacilli, to a more diverse ecosystem resembling that of healthy donors, dominated by Bacteroidetes and Clostridium groups, including butyrate-producing bacteria. We identified specific multi-species networks and signature microbial groups that were either depleted or restored as a result of the treatment. The changes persisted over time. Comprehensive and deep analyses of the microbiota of patients before and after treatment exposed a therapeutic reset from a diseased state towards a healthy profile. The identification of microbial groups that constitute a niche for C. difficile overgrowth, as well as those driving the reinstallation of a healthy intestinal microbiota, could contribute to the development of biomarkers predicting recurrence and treatment outcome, identifying an optimal microbiota composition that could lead to targeted treatment strategies. 相似文献
52.
53.
Phylogeny of some Fusarium species, as determined by large-subunit rRNA sequence comparison 总被引:16,自引:0,他引:16
Fifty-two strains from eight species of Fusarium were analyzed by rapid
rRNA sequencing. Two highly variable stretches (138 and 214 nucleotides) of
the 5' end of the 28S-like rRNA molecule were sequenced. Such stretches
permit evaluation of the divergence between closely related species and
even between varieties within a species. The phylogenetic tree computed
from the number of nucleotide differences shows seven Fusarium species to
be more closely related to one another than the eighth species, F. nivale,
is to them. On the basis of these data, we discuss both the phylogenetic
value of taxonomical criteria and the impact of our findings on the
demarcation of the genus Fusarium. We conclude that this method is suitable
for establishing a precise phylogeny between closely related species within
a genus.
相似文献
54.
55.
Nelson JF da Silveira Helen A Arcuri Carlos E Bonalumi Fátima P de Souza Isabel MVGC Mello Paula Rahal Jo?o RR Pinho Walter F de Azevedo 《BMC structural biology》2005,5(1):1
Background
Hepatitis C virus (HCV) currently infects approximately three percent of the world population. In view of the lack of vaccines against HCV, there is an urgent need for an efficient treatment of the disease by an effective antiviral drug. Rational drug design has not been the primary way for discovering major therapeutics. Nevertheless, there are reports of success in the development of inhibitor using a structure-based approach. One of the possible targets for drug development against HCV is the NS3 protease variants. Based on the three-dimensional structure of these variants we expect to identify new NS3 protease inhibitors. In order to speed up the modeling process all NS3 protease variant models were generated in a Beowulf cluster. The potential of the structural bioinformatics for development of new antiviral drugs is discussed. 相似文献56.
Letenneur L Pérès K Fleury H Garrigue I Barberger-Gateau P Helmer C Orgogozo JM Gauthier S Dartigues JF 《PloS one》2008,3(11):e3637
Background
Herpes Simplex Virus (HSV) infection has been proposed as a possible risk factor of Alzheimer''s Disease (AD) notably because it is neurotropic, ubiquitous in the general population and able to establish lifelong latency in the host. The fact that HSV was present in elderly subjects with AD suggests that the virus could be a co-factor of the disease. We investigated the risk of developing AD in anti-HSV immunoglobulin G (IgG) positive subjects (indicator of a lifelong infection to HSV) and IgM-positive subjects (indicator of primary infection or reactivation of the virus) in a longitudinal population-based cohort of elderly subjects living in the community.Methods
Cox proportional hazard models were used to study the risk of developing AD according to the presence or not of anti-HSV IgG and IgM antibodies, assessed in the sera of 512 elderly initially free of dementia followed for 14 years.Results
During the follow-up, 77 incident AD cases were diagnosed. Controlled for age, gender, educational level and Apolipoprotein E4 (APOE4) status, IgM-positive subjects showed a significant higher risk of developing AD (HR = 2.55; 95% CI [1.38–4.72]), although no significant increased risk was observed in IgG-positive subjects (HR = 1.67; 95%CI [0.75–3.73]). No modification effect with APOE4 status was found.Conclusion
Reactivation of HSV seropositivity is highly correlated with incident AD. HSV chronic infection may therefore be contributive to the progressive brain damage characteristic of AD. 相似文献57.
B Kornmatitsuk E Dahl E Ropstad JF Beckers H Gustafsson H Kindahl 《Acta veterinaria Scandinavica》2004,45(1):47
The high incidence of stillbirth in Swedish Holstein heifers has increased continuously during the last 15 years to an average
of 11% today. The pathological reasons behind the increased incidence of stillbirth are unknown. The present experiment was
undertaken to investigate possible causes of stillbirth and to study possible physiological markers for predicting stillbirth.
Twenty Swedish Holstein dairy heifers sired by bulls with breeding values for a high risk of stillbirth (n = 12) (experimental
group) and a low risk of stillbirth (n = 8) (control group, group B) were selected based on information in the Swedish AI-data
base. The experimental group consisted of 2 subgroups of heifers (groups A1 and A2) inseminated with 2 different bulls with
3.5% and 9% higher stillbirth rates than the average, and the control group consisted of heifers pregnant with 5 different
bulls with 0%–6% lower stillbirth rates than the average. The bull used for group A1 had also calving difficulties due to
large calves as compared to the bull in group A2 showing no calving difficulties. The heifers were supervised from 6–7 months
of pregnancy up to birth, and the pregnancies and parturitions were compared between groups regarding hormonal levels, haematology,
placental characteristics and calf viability. In group A1, 1 stillborn, 1 weak and 4 normal calves were recorded. In group
A2, 2 stillborn and 4 normal calves were registered. All animals in the control group gave birth to a normal living calf without
any assistance. The weak calf showed deviating profiles of body temperature, saturated oxygen and heart rates, compared with
the normal living calves. No differences of the placentome thickness, measured in vivo by ultrasonography were seen between the groups. The number of leukocytes and differential cell counts in groups A1 and A2
followed the profiles found in the control group. In group A1, a slight decrease of oestrone sulphate (E1SO4) levels was found
in the animal delivering a stillborn calf from the first 24-h blood sampling at 6 weeks to the second at 3 weeks prior to
delivery, while the levels of E1SO4 at both periods in the animal delivering a weak calf followed the profile in animals delivering
a normal living calf. During late pregnancy and at the time of parturition, the levels of E1SO4 and PAGs in animals delivering
a stillborn or weak calf (from group A1) followed the normal profiles found in animals delivering a normal living calf. In
group A2, low levels of E1SO4 and pregnancy associated glycoproteins (PAGs) over 24 h at both 3 and 6 weeks prior to parturition
(<1.5 nmol/L) were recorded in animals delivering a stillborn calf. During late pregnancy and parturition, the levels of E1SO4
and PAGs were slightly lower during 30–50 days prior to delivery and increased with a lower magnitude at the time of parturition.
In conclusion, our results indicate that the aetiology behind stillbirth varies depending on the AI-bulls used and is associated
with dystocia or low viability of the calves. Deviating profiles of oestrone sulphate (E1SO4) and pregnancy associated glycoproteins
(PAGs) in animals delivering a stillborn calf not caused by dystocia were observed, suggesting placental dysfunction as a
possible factor. The finding suggests that the analyses of E1SO4 and PAGs could be used for monitoring foetal well-being in
animals with a high risk of stillbirth at term. 相似文献
58.
In our studies of the health effects of internalized depleted uranium, we developed a simple and rapid light microscopic method to stain specifically intracellular uranium deposits. Using J774 cells, a mouse macrophage line, treated with uranyl nitrate and the pyridylazo dye 2-(5-bromo-2- pyridylazo)-5-diethylaminophenol, uranium uptake by the cells was followed. Specificity of the stain for uranium was accomplished by using masking agents to prevent the interaction of the stain with other metals. Prestaining wash consisting of a mixture of sodium citrate and ethylenediaminetetraacetic acid eliminated staining of metals other than uranium. The staining solution consisted of the pyridylazo dye in borate buffer along with a quaternary ammonium salt, ethylhexadecyldimethylammonium bromide, and the aforementioned sodium citrate/ethylene-diaminetetraacetic acid mixture. The buffer was essential for maintaining the pH within the optimum range of 8 to 12, and the quaternary ammonium salt prevented precipitation of the dye. Staining was conducted at room temperature and was complete in 30 min. Staining intensity correlated with both uranyl nitrate concentration and incubation time. Our method provides a simple procedure for detecting intracellular uranium deposits in macrophages. 相似文献
59.
Glycosylation sites and site-specific glycosylation in human Tamm- Horsfall glycoprotein 总被引:4,自引:1,他引:3
The N-glycosylation sites of human Tamm-Horsfall glycoprotein from one
healthy male donor have been characterized, based on an approach using
endoproteinase Glu-C (V-8 protease, Staphylococcus aureus ) digestion and a
combination of chromatographic techniques, automated Edman sequencing, and
fast atom bombardment mass spectrometry. Seven out of the eight potential
N-glycosylation sites, namely, Asn52, Asn56, Asn208, Asn251, Asn298,
Asn372, and Asn489, turned out to be glycosylated, and the potential
glycosylation site at Asn14, being close to the N-terminus, is not used.
The carbohydrate microheterogeneity on three of the glycosylation sites was
studied in more detail by high-pH anion-exchange chromatographic profiling
and 500 MHz1H-NMR spectroscopy. Glycosylation site Asn489 contains mainly
di- and tri-charged oligosaccharides which comprise, among others, the
GalNAc4 S (beta1-4)GlcNAc terminal sequence. Only glycosylation site Asn251
bears oligomannose-type carbohydrate chains ranging from Man5GlcNAc2to
Man8GlcNAc2, in addition to a small amount of complex- type structures.
Profiling of the carbohydrate moieties of Asn208 indicates a large
heterogeneity, similar to that established for native human Tamm-Horsfall
glycoprotein, namely, multiply charged complex-type carbohydrate
structures, terminated by sulfate groups, sialic acid residues, and/or the
Sda-determinant.
相似文献
60.
Alzheimer's disease and related disorders (dementia) are a major public health problem due to the number of cases in the general population, the projections for the future, and the consequences of these diseases. We can estimate that about 850 000 cases of dementia were present in France in 2005 and this number will increase to 1,200,000 in 2020 and 2,100,000 in 2040 if the incidence and the duration of the disease did not change. The development of prevention is therefore necessary. Four ways of prevention are credible. The most important is the treatment of vascular risk factors and particularly hypertension. Other ways are nutritional factors, stimulating leisure activities and depression. 相似文献