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991.
Kenny-Caffey syndrome (KCS) and the similar but more severe osteocraniostenosis (OCS) are genetic conditions characterized by impaired skeletal development with small and dense bones, short stature, and primary hypoparathyroidism with hypocalcemia. We studied five individuals with KCS and five with OCS and found that all of them had heterozygous mutations in FAM111A. One mutation was identified in four unrelated individuals with KCS, and another one was identified in two unrelated individuals with OCS; all occurred de novo. Thus, OCS and KCS are allelic disorders of different severity. FAM111A codes for a 611 amino acid protein with homology to trypsin-like peptidases. Although FAM111A has been found to bind to the large T-antigen of SV40 and restrict viral replication, its native function is unknown. Molecular modeling of FAM111A shows that residues affected by KCS and OCS mutations do not map close to the active site but are clustered on a segment of the protein and are at, or close to, its outer surface, suggesting that the pathogenesis involves the interaction with as yet unidentified partner proteins rather than impaired catalysis. FAM111A appears to be crucial to a pathway that governs parathyroid hormone production, calcium homeostasis, and skeletal development and growth.  相似文献   
992.
Aquaporin-4 (AQP4) is the primary cellular water channel in the brain and is abundantly expressed by astrocytes along the blood-brain barrier and brain-cerebrospinal fluid interfaces. Water transport via AQP4 contributes to the activity-dependent volume changes of the extracellular space (ECS), which affect extracellular solute concentrations and neuronal excitability. AQP4 is anchored by α-syntrophin (α-syn), the deletion of which leads to reduced AQP4 levels in perivascular and subpial membranes. We used the real-time iontophoretic method and/or diffusion-weighted magnetic resonance imaging to clarify the impact of α-syn deletion on astrocyte morphology and changes in extracellular diffusion associated with cell swelling in vitro and in vivo. In mice lacking α-syn, we found higher resting values of the apparent diffusion coefficient of water (ADCW) and the extracellular volume fraction (α). No significant differences in tortuosity (λ) or non-specific uptake (k′), were found between α-syn-negative (α-syn −/−) and α-syn-positive (α-syn +/+) mice. The deletion of α-syn resulted in a significantly smaller relative decrease in α observed during elevated K+ (10 mM) and severe hypotonic stress (−100 mOsmol/l), but not during mild hypotonic stress (−50 mOsmol/l). After the induction of terminal ischemia/anoxia, the final values of ADCW as well as of the ECS volume fraction α indicate milder cell swelling in α-syn −/− in comparison with α-syn +/+ mice. Shortly after terminal ischemia/anoxia induction, the onset of a steep rise in the extracellular potassium concentration and an increase in λ was faster in α-syn −/− mice, but the final values did not differ between α-syn −/− and α-syn +/+ mice. This study reveals that water transport through AQP4 channels enhances and accelerates astrocyte swelling. The substantially altered ECS diffusion parameters will likely affect the movement of neuroactive substances and/or trophic factors, which in turn may modulate the extent of tissue damage and/or drug distribution.  相似文献   
993.
Differential modulation of NF-κB during meningococcal infection is critical in innate immune response to meningococcal disease. Non-invasive isolates of Neisseria meningitidis provoke a sustained NF-κB activation in epithelial cells. However, the hyperinvasive isolates of the ST-11 clonal complex (ST-11) only induce an early NF-κB activation followed by a sustained activation of JNK and apoptosis. We show that this temporal activation of NF-κB was caused by specific cleavage at the C-terminal region of NF-κB p65/RelA component within the nucleus of infected cells. This cleavage was mediated by the secreted 150 kDa meningococcal ST-11 IgA protease carrying nuclear localisation signals (NLS) in its α-peptide moiety that allowed efficient intra-nuclear transport. In a collection of non-ST-11 healthy carriage isolates lacking NLS in the α-peptide, secreted IgA protease was devoid of intra-nuclear transport. This part of iga polymorphism allows non-invasive isolates lacking NLS, unlike hyperinvasive ST-11 isolates of N. meningitides habouring NLS in their α-peptide, to be carried asymptomatically in the human nasopharynx through selective eradication of their ability to induce apoptosis in infected epithelial cells.  相似文献   
994.
The contribution deals with the phytocenological analysis of theRondeletio correifoliae-Andropogonetum multinervosi, an endemic savanna association occuring on the Siguanea Hills (Sierra de la Siguanea) near the Colony Hotel.  相似文献   
995.
Anaerobic degradation of naphthalene, 2-methylnaphthalene, and tetralin (1,2,3,4-tetrahydronaphthalene) was investigated with a sulfate-reducing enrichment culture obtained from a contaminated aquifer. Degradation studies with tetralin revealed 5,6,7,8-tetrahydro-2-naphthoic acid as a major metabolite indicating activation by addition of a C(1) unit to tetralin, comparable to the formation of 2-naphthoic acid in anaerobic naphthalene degradation. The activation reaction was specific for the aromatic ring of tetralin; 1,2,3,4-tetrahydro-2-naphthoic acid was not detected. The reduced 2-naphthoic acid derivatives tetrahydro-, octahydro-, and decahydro-2-naphthoic acid were identified consistently in supernatants of cultures grown with either naphthalene, 2-methylnaphthalene, or tetralin. In addition, two common ring cleavage products were identified. Gas chromatography-mass spectrometry (GC-MS) and high-resolution GC-MS analyses revealed a compound with a cyclohexane ring and two carboxylic acid side chains as one of the first ring cleavage products. The elemental composition was C(11)H(16)O(4) (C(11)H(16)O(4)-diacid), indicating that all carbon atoms of the precursor 2-naphthoic acid structure were preserved in this ring cleavage product. According to the mass spectrum, the side chains could be either an acetic acid and a propenic acid, or a carboxy group and a butenic acid side chain. A further ring cleavage product was identified as 2-carboxycyclohexylacetic acid and was assumed to be formed by beta-oxidation of one of the side chains of the C(11)H(16)O(4)-diacid. Stable isotope-labeling growth experiments with either (13)C-labeled naphthalene, per-deuterated naphthalene-d(8), or a (13)C-bicarbonate-buffered medium showed that the ring cleavage products derived from the introduced carbon source naphthalene. The series of identified metabolites suggests that anaerobic degradation of naphthalenes proceeds via reduction of the aromatic ring system of 2-naphthoic acid to initiate ring cleavage in analogy to the benzoyl-coenzyme A pathway for monoaromatic hydrocarbons. Our findings provide strong indications that further degradation goes through saturated compounds with a cyclohexane ring structure and not through monoaromatic compounds. A metabolic pathway for anaerobic degradation of bicyclic aromatic hydrocarbons with 2-naphthoic acid as the central intermediate is proposed.  相似文献   
996.
Sýkorová E  Lim KY  Fajkus J  Leitch AR 《Chromosoma》2003,112(4):164-172
The genus Cestrum in the Solanaceae family is unusual in lacking Arabidopsis-type telomeres (TTTAGGG)n, although short interstitial telomeric sequences (ITSs) occur scattered throughout the genome in both orientations. To isolate candidate telomeric sequences in Cestrum we assumed that some of the ITSs were residues of the original telomeres and that they may still be located in the vicinity of present-day telomeres. Three sequence types associated with ITSs were cloned and characterized; these were termed NA3G, BR23 and A/T-rich minisatellite. These high copy number sequences are dispersed across the genome and clustered at a number of chromosomal loci. Their association with ITSs, which can act as recombination hotspots, might indicate past recombination and chromosomal fusion events, processes that may have contributed to the large size of Cestrum chromosomes. The sequences are frequently arranged as NA3G-ITS-BR23 blocks embedded in an A/T-rich minisatellite array. The A/T-rich minisatellite is of particular interest because the consensus 5-T4–5AGCAG-3 might be a derivative of typical eukaryotic telomeric sequence motifs. The sequence is abundant at the end of some chromosomes in C. parqui and is found not only in Cestrum but also in the closely related genera Sessea and Vestia, which also lack Arabidopsis-type telomeric sequences. However, the sequence is absent from the Solanaceae genera investigated that are outside the group, including the closely related genus Streptosolen, which all have the Arabidopsis-type telomere. The data indicate that the A/T rich minisatellite might have evolved in response to the loss of Arabidopsis-type telomeres.Communicated by E.R. Schmidt  相似文献   
997.
The fermentability of rice bran (RB), alone or in combination with one of two probiotics, by canine faecal microbiota was evaluated in stirred, pH-controlled, anaerobic batch cultures. RB enhanced the levels of bacteria detected by probes Bif164 (bifidobacteria) and Lab158 (lactic acid bacteria); however, addition of the probiotics did not have a significant effect on the predominant microbial counts compared with RB alone. RB sustained levels of Bifidobacterium longum 05 throughout the fermentation; in contrast, Lactobacillus acidophilus 14 150B levels decreased significantly after 5-h fermentation. RB fermentation induced changes in the short-chain fatty acid (SCFA) profile. However, RB combined with probiotics did not alter the SCFA levels compared with RB alone. Denaturing gradient gel electrophoresis analysis of samples obtained at 24 h showed a treatment effect with RB, which was not observed in the RB plus probiotic systems. Overall, the negative controls displayed lower species richness than the treatment systems and their banding profiles were distinct. This study illustrates the ability of a common ingredient found in pet food to modulate the canine faecal microbiota and highlights that RB may be an economical alternative to prebiotics for use in dog food.  相似文献   
998.
Even though the uptake and assimilation of organic compounds by phytoplankton has been long recognized, very little is still known about its potential ecological role in natural marine communities and whether it varies depending on the light regimes the algae experience. We combined measurements of size-fractionated assimilation of trace additions of 3H-leucine and 35S-dimethylsulfoniopropionate (DMSP) with microautoradiography to assess the extent and relevance of osmoheterotrophy in summer phytoplankton assemblages from Arctic and Antarctic waters, and the role of solar radiation on it was further investigated by exposing samples to different radiation spectra. Significant assimilation of both substrates occurred in the size fraction containing most phytoplankton (>5 µm), sunlight exposure generally increasing 35S-DMSP-sulfur assimilation and decreasing 3H-leucine assimilation. Microautoradiography revealed that the capacity to take up both organic substrates seemed widespread among different polar algal phyla, particularly in pennate and centric diatoms, and photosynthetic dinoflagellates. Image analysis of the microautoradiograms showed for the first time interspecific variability in the uptakes of 35S-DMSP and 3H-leucine by phytoplankton depending on the solar spectrum. Overall, these results suggest that the role of polar phytoplankton in the utilization of labile dissolved organic matter may be significant under certain conditions and further confirm the relevance of solar radiation in regulating heterotrophy in the pelagic ocean.  相似文献   
999.
The measurement of core body temperature is an efficient method for monitoring heat stress amongst workers in hot conditions. However, invasive measurement of core body temperature (e.g. rectal, intestinal, oesophageal temperature) is impractical for such applications. Therefore, the aim of this study was to define relevant non-invasive measures to predict core body temperature under various conditions. We conducted two human subject studies with different experimental protocols, different environmental temperatures (10 °C, 30 °C) and different subjects. In both studies the same non-invasive measurement methods (skin temperature, skin heat flux, heart rate) were applied. A principle component analysis was conducted to extract independent factors, which were then used in a linear regression model. We identified six parameters (three skin temperatures, two skin heat fluxes and heart rate), which were included for the calculation of two factors. The predictive value of these factors for core body temperature was evaluated by a multiple regression analysis. The calculated root mean square deviation (rmsd) was in the range from 0.28 °C to 0.34 °C for all environmental conditions. These errors are similar to previous models using non-invasive measures to predict core body temperature. The results from this study illustrate that multiple physiological parameters (e.g. skin temperature and skin heat fluxes) are needed to predict core body temperature. In addition, the physiological measurements chosen in this study and the algorithm defined in this work are potentially applicable as real-time core body temperature monitoring to assess health risk in broad range of working conditions.  相似文献   
1000.
The stability and recovery of recombinant proteins expressed in plants are improved by fusion to elastin-like peptides (ELPs). In order to test the suitability of ELP for the production of pharmaceutical proteins, transgenic plants were created that individually expressed the light and heavy chains of the broadly neutralizing anti-human immunodeficiency virus type 1 (anti-HIV-1) monoclonal antibody 2F5, which is being evaluated as a microbicide component. The antibody chains were expressed both with and without a C-terminal ELP fusion. Crossing these plants in all combinations resulted in transgenic lines producing the full antibody in four formats, with ELP on either the light or heavy chains, on both or on neither. Characterization of the affinity-purified antibodies by surface plasmon resonance spectroscopy showed that the kinetic binding parameters were identical to those of a Chinese hamster ovary (CHO) cell counterpart lacking ELP. N -Glycan analysis showed that all four derivatives contained predominantly oligo-mannose-type N -glycans and that the ELP fusions had no significant effect on N -glycan structure. It was concluded that ELP fusion to the light chain, heavy chain or both chains of a plant-derived antibody had no adverse affects on protein quality, but had a positive impact on the yield. ELP fusions do not interfere with folding, assembly, trafficking in the secretory pathway or post-translational modification, but enhance stability whilst at the same time simplifying recovery.  相似文献   
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