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81.
The macaque brain serves as a model for the human brain, but its suitability is challenged by unique human features, including connectivity reconfigurations, which emerged during primate evolution. We perform a quantitative comparative analysis of the whole brain macroscale structural connectivity of the two species. Our findings suggest that the human and macaque brain as a whole are similarly wired. A region-wise analysis reveals many interspecies similarities of connectivity patterns, but also lack thereof, primarily involving cingulate regions. We unravel a common structural backbone in both species involving a highly overlapping set of regions. This structural backbone, important for mediating information across the brain, seems to constitute a feature of the primate brain persevering evolution. Our findings illustrate novel evolutionary aspects at the macroscale connectivity level and offer a quantitative translational bridge between macaque and human research.  相似文献   
82.
83.
DNA damage responses (DDR) invoke senescence or apoptosis depending on stimulus intensity and the degree of activation of the p53-p21(Cip1/Waf1) axis; but the functional impact of NF-κB signaling on these different outcomes in normal vs. human cancer cells remains poorly understood. We investigated the NF-κB-dependent effects and mechanism underlying reactive oxygen species (ROS)-mediated DDR outcomes of normal human lung fibroblasts (HDFs) and A549 human lung cancer epithelial cells. To activate DDR, ROS accumulation was induced by different doses of H(2)O(2). The effect of ROS induction caused a G2 or G2-M phase cell cycle arrest of both human cell types. However, ROS-mediated DDR eventually culminated in different end points with HDFs undergoing premature senescence and A549 cancer cells succumbing to apoptosis. NF-κB p65/RelA nuclear translocation and Ser536 phosphorylation were induced in response to H(2)O(2)-mediated ROS accumulation. Importantly, blocking the activities of canonical NF-κB subunits with an IκBα super-repressor or suppressing canonical NF-κB signaling by IKKβ knock-down accelerated HDF premature senescence by up-regulating the p53-p21(Cip1/Waf1) axis; but inhibiting the canonical NF-κB pathway exacerbated H(2)O(2)-induced A549 cell apoptosis. HDF premature aging occurred in conjunction with γ-H2AX chromatin deposition, senescence-associated heterochromatic foci and beta-galactosidase staining. p53 knock-down abrogated H(2)O(2)-induced premature senescence of vector control- and IκBαSR-expressing HDFs functionally linking canonical NF-κB-dependent control of p53 levels to ROS-induced HDF senescence. We conclude that IKKβ-driven canonical NF-κB signaling has different functional roles for the outcome of ROS responses in the contexts of normal vs. human tumor cells by respectively protecting them against DDR-dependent premature senescence and apoptosis.  相似文献   
84.
At each round of infection, viruses fall apart to release their genome for replication, and then reassemble into stable particles within the same host cell. For most viruses, the structural details that underlie these disassembly and assembly reactions are poorly understood. Cryo-electron tomography (cryo-ET), a unique method to investigate large and asymmetric structures at the near molecular resolution, was previously used to study the complex structure of vaccinia virus (VV). Here we study the disassembly of VV by cryo-ET on intact, rapidly frozen, mammalian cells, infected for up to 60 minutes. Binding to the cell surface induced distinct structural rearrangements of the core, such as a shape change, the rearrangement of its surface spikes and de-condensation of the viral DNA. We propose that the cell surface induced changes, in particular the decondensation of the viral genome, are a prerequisite for the subsequent release of the vaccinia DNA into the cytoplasm, which is followed by its cytoplasmic replication. Generally, this is the first study that employs whole cell cryo-ET to address structural details of pathogen-host cell interaction.  相似文献   
85.

Background

Comorbidities are common in chronic systemic connective tissue diseases and are associated with adverse outcomes, increased morbidity and mortality. Although the prevalence of comorbidities has been well-studied in isolated diseases, comparative studies between different autoimmune diseases are limited. In this study, we compared the prevalence of common comorbidities between patients with systemic sclerosis (SSc) and patients with rheumatoid arthritis (RA).

Methods

Between 2016 and 2017, 408 consecutive patients with SSc, aged 59?±?13?years (87% women), were matched 1:1 for age and gender with 408 patients with RA; mean disease duration was 10?±?8 and 9?±?8?years, respectively. Rates of cardiovascular risk factors, coronary artery disease, stroke, chronic obstructive pulmonary disease (COPD), osteoporosis, neoplasms and depression were compared between the two cohorts.

Results

The prevalence of dyslipidemia (18.4% vs 30.1%, p?=?0.001) and diabetes mellitus (5.6% vs 11.8%, p?=?0.007) and body mass index (p?=?0.001) were lower in SSc compared to RA, while there was no difference in arterial hypertension or smoking. While there was a trend for lower prevalence of ischemic stroke in SSc than in RA (1.1% vs 3.2%, p?=?0.085), coronary artery disease was comparable (2.7% vs 3.7%). No differences were found between patients with SSc and patients with RA in the prevalence of COPD (5.2% vs 3.7%), osteoporosis (24% vs 22%) or neoplasms overall (1.1% vs 1.7%); however lung cancer was the most prevalent cancer in SSc (7/17, 41%), whereas hematologic malignancies (7/19, 36%) and breast cancer (7/19, 36%) predominated in RA. Depression was more prevalent in SSc (22% vs 12%, p?=?0.001), especially in diffuse SSc.

Conclusions

Despite the prevalence of dyslipidemia and diabetes mellitus in SSc being almost half that in RA, the cardiovascular comorbidity burden appears to be similar in both. The overall prevalence of neoplasms is no higher in SSc than in RA, but SSc has a more negative impact on quality of life, as clearly, more SSc patients develop depression compared to patients with RA.
  相似文献   
86.
An ongoing re-investigation of the early Miocene Saldanha Bay (South Africa) palynoflora, using combined light and scanning electron microscopy (single grain method), is revealing several pollen types new to the African fossil record. One of the elements identified is Loranthaceae pollen. These grains represent the first and only fossil record of Loranthaceae in Africa. The fossil pollen grains resemble those produced by the core Lorantheae and are comparable to recent Asian as well as some African taxa/lineages. Molecular and fossil signals indicate that Loranthaceae dispersed into Africa via Asia sometime during the Eocene. The present host range of African Loranthaceae and the composition of the palynoflora suggest that the fossil had a range of potential host taxa to parasitise during the early Miocene in the Saldanha Bay region.  相似文献   
87.
88.
A chemostat is well known to be a tool for selecting microorganisms with minimum doubling times during continuous fermentation, which is of special importance for slowly growing microorganisms like those used in anaerobic digestion. By set point control (SPC) of the operation parameters — especially of residence time — by means of a process computer, the selection stress can be optimized. A continuous operation very close to wash-out conditions is possible in spite of the microorganisms population changing properties. For anaerobic digestion of acid, a biomass was obtained that could reduce the chemical oxygen demand (COD) by more than 20 kg per kg dry biomass per d. For a high space-time yield, not only a high biomass activity but also a high biomass concentration is needed; therefore, methods for biomass retention or recycling have been developed. A porous glass sponge with free permeable macropores that can be colonized by anaerobic microorganisms proved to be especially useful. Raschig ring-shaped particles of this material were used in fixed-bed loop reactors for the anaerobic digestion of organically high polluted effluents.Paper presented at the 6th Japanese-German Workshop on Applied Genetics and Bioreactor in Kyoto, November 24–25, 1987  相似文献   
89.
The specific activities of acid (pH 5.5) and neutral (pH 7) DNases and RNases were determined in alfalfa (Medicago sativa L.) seedlings grown in the dark in the presence of 3.7 mM paraquat (PQ) or 1 mM roundup (RD). Seedlings were taken at 0, 1, 3, and 5 days. Plant growth parameters (plant height and fresh weight) were dramatically reduced under these conditions of growth comparing to the control (grown in water). The DNase and RNase specific activities of herbicide-treated seedlings were reduced. The reduction of activities ranged by about 50–90 and 15–70% in PQ- and RD-treated seedlings, respectively. In vitro, PQ- and RD-treated nucleic acids [single-stranded DNA (ssDNA), RNA, and plasmid DNA (pl-DNA)] were incubated with acid and neutral nucleases. Both enzymes were isolated and purified from alfalfa seedlings. Electrophoretic analysis on agarose gel of the above incubated mixtures revealed the following: (a) neutral nuclease (pH 7) was capable of hydrolyzing PQ-treated ssDNA while acid nuclease (pH 5.5) was incapable. This could be due to the fact that acid and neutral nucleases displayed different base linkage specificity toward ssDNA; (b) RD formed strong complexes with ssDNA that were unable to be hydrolyzed by both nucleases; (c) in contrast, both enzymes were capable of hydrolyzing PQ- or RD-treated RNA; (d) neutral nuclease was capable of nicking and linearizing both PQ- and RD-treated pl-DNA while acid nuclease had the same activity only toward the PQ-treated pl-DNA; (e) the enzyme activities were not inhibited in the presence of both herbicides. The data suggest that the complexes of PQ or RD with DNA should not be functional substrates of nucleases, and consequently cell processes (e.g., metabolism of nucleic acids, gene expression, replication), in which DNA and nucleases are involved, could be disturbed.  相似文献   
90.
The evolution of the coleopteran suborder Adephaga is discussed based on a robust phylogenetic background. Analyses of morphological characters yield results nearly identical to recent molecular phylogenies, with the highly specialized Gyrinidae placed as sister to the remaining families, which form two large, reciprocally monophyletic subunits, the aquatic Haliplidae + Dytiscoidea (Meruidae, Noteridae, Aspidytidae, Amphizoidae, Hygrobiidae, Dytiscidae) on one hand, and the terrestrial Geadephaga (Trachypachidae + Carabidae) on the other. The ancestral habitat of Adephaga, either terrestrial or aquatic, remains ambiguous. The former option would imply two or three independent invasions of aquatic habitats, with very different structural adaptations in larvae of Gyrinidae, Haliplidae and Dytiscoidea.  相似文献   
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