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81.
Speyer CL Rancilio NJ McClintock SD Crawford JD Gao H Sarma JV Ward PA 《American journal of physiology. Cell physiology》2005,289(4):C881-C890
Complex I (NADH:ubiquinone oxidoreductase) is the largest multisubunit assembly of the oxidative phosphorylation system, and its malfunction is associated with a wide variety of clinical syndromes ranging from highly progressive, often early lethal, encephalopathies to neurodegenerative disorders in adult life. The changes in mitochondrial structure and function that are at the basis of the clinical symptoms are poorly understood. Video-rate confocal microscopy of cells pulse-loaded with mitochondria-specific rhodamine 123 followed by automated analysis of form factor (combined measure of length and degree of branching), aspect ratio (measure of length), and number of revealed marked differences between primary cultures of skin fibroblasts from 13 patients with an isolated complex I deficiency. These differences were independent of the affected subunit, but plotting of the activity of complex I, normalized to that of complex IV, against the ratio of either form factor or aspect ratio to number revealed a linear relationship. Relatively small reductions in activity appeared to be associated with an increase in form factor and never with a decrease in number, whereas relatively large reductions occurred in association with a decrease in form factor and/or an increase in number. These results demonstrate that complex I activity and mitochondrial structure are tightly coupled in human isolated complex I deficiency. To further prove the relationship between aberrations in mitochondrial morphology and pathological condition, fibroblasts from two patients with a different mutation but a highly fragmented mitochondrial phenotype were fused. Full restoration of the mitochondrial network demonstrated that this change in mitochondrial morphology was indeed associated with human complex I deficiency. mitochondria; oxidative phosphorylation; rhodamine 123; fibroblast 相似文献
82.
Inorganic soil nitrogen under grassland plant communities of different species composition and diversity 总被引:3,自引:0,他引:3
Cecilia Palmborg Michael Scherer-Lorenzen Ari Jumpponen Georg Carlsson Kerstin Huss-Danell Peter Högberg 《Oikos》2005,110(2):271-282
We measured aboveground plant biomass and soil inorganic nitrogen pools in a biodiversity experiment in northern Sweden, with plant species richness ranging from 1 to 12 species. In general, biomass increased and nitrate pools decreased with increasing species richness. Transgressive overyielding of mixed plant communities compared to the most productive of the corresponding monocultures occurred in communities with and without legumes. N2 -fixing legumes had a fertilizing function, while non-legumes had a N retaining function. Plant communities with only legumes had a positive correlation between biomass and soil nitrate content, whereas in plant communities without legumes they were negatively correlated. Both nitrate and ammonium soil pools in mixed non-legume communities were approximately equal to the lowest observed in the corresponding monocultures. In mixed legume/non-legume communities, no correlation was found for soil nitrate with either biomass or legume biomass as percentage of total biomass. The idea of complementarity among species in nitrogen acquisition was supported in both pure non-legume and mixed non-legume/legume communities. In the latter, however, facilitation through increased nitrogen availability and retention, was probably dominating. Our results suggest that diversity effects on biomass and soil N pools through resource use complementarity depend on the functional traits of species, especially N2 fixation or high productivity. 相似文献
83.
Daniele Capitanio Michele Vasso Sara De Palma Chiara Fania Enrica Torretta Francesco P. Cammarata Valerio Magnaghi Patrizia Procacci Cecilia Gelfi 《Proteomics》2016,16(4):645-656
In the skeletal muscle, the ageing process is characterized by a loss of muscle mass and strength, coupled with a decline of mitochondrial function and a decrease of satellite cells. This profile is more pronounced in hindlimb than in forelimb muscles, both in humans and in rodents. Utilizing light and electron microscopy, myosin heavy chain isoform distribution, proteomic analysis by 2D‐DIGE, MALDI‐TOF MS and quantitative immunoblotting, this study analyzes the protein levels and the nuclear localization of specific molecules, which can contribute to a preferential muscle loss. Our results identify the molecular changes in the hindlimb (gastrocnemius) and forelimb (triceps) muscles during ageing in rats (3‐ and 22‐month‐old). Specifically, the oxidative metabolism contributes to tissue homeostasis in triceps, whereas respiratory chain disruption and oxidative‐stress‐induced damage imbalance the homeostasis in gastrocnemius muscle. High levels of dihydrolipoyllysine‐residue acetyltransferase (Dlat) and ATP synthase subunit alpha (Atp5a1) are detected in triceps and gastrocnemius, respectively. Interestingly, in triceps, both molecules are increased in the nucleus in aged rats and are associated to an increased protein acetylation and myoglobin availability. Furthermore, autophagy is retained in triceps whereas an enhanced fusion, decrement of mitophagy and of regenerative potential is observed in aged gastrocnemius muscle. 相似文献
84.
Nguyen le B Diskin SJ Capasso M Wang K Diamond MA Glessner J Kim C Attiyeh EF Mosse YP Cole K Iolascon A Devoto M Hakonarson H Li HK Maris JM 《PLoS genetics》2011,7(3):e1002026
Neuroblastoma is a malignant neoplasm of the developing sympathetic nervous system that is notable for its phenotypic diversity. High-risk patients typically have widely disseminated disease at diagnosis and a poor survival probability, but low-risk patients frequently have localized tumors that are almost always cured with little or no chemotherapy. Our genome-wide association study (GWAS) has identified common variants within FLJ22536, BARD1, and LMO1 as significantly associated with neuroblastoma and more robustly associated with high-risk disease. Here we show that a GWAS focused on low-risk cases identified SNPs within DUSP12 at 1q23.3 (P = 2.07×10−6), DDX4 and IL31RA both at 5q11.2 (P = 2.94×10−6 and 6.54×10−7 respectively), and HSD17B12 at 11p11.2 (P = 4.20×10−7) as being associated with the less aggressive form of the disease. These data demonstrate the importance of robust phenotypic data in GWAS analyses and identify additional susceptibility variants for neuroblastoma. 相似文献
85.
Heliotherapy for Neonatal Hyperbilirubinemia in Southwest,Nigeria: A Baseline Pre-Intervention Study
Background
A novel filtered-sunlight phototherapy (FSPT) device has been demonstrated to be safe and efficacious for treating infants with neonatal jaundice in resource-constrained tropical settings. We set out to provide baseline data for evaluating the clinical impact of this device in a referral pediatric hospital.Methods
We reviewed the medical records of infants admitted for neonatal hyperbilirubinemia in an inner-city Children’s Hospital in Lagos, between January 2012 and December 2014 to determine the pattern, treatment and outcomes during the pre-intervention period. Factors associated with adverse outcomes were identified through multivariable logistic regression.Results
Of the 5,229 neonatal admissions over the period, a total of 1,153 (22.1%) were admitted for neonatal hyperbilirubinemia. Complete records for 1,118 infants were available for analysis. The incidence of acute bilirubin encephalopathy (ABE) and exchange transfusion (ET) were 17.0% (95% CI: 14.9%–19.3%) and 31.5% (95% CI: 28.8%–34.3%) respectively. A total of 61 (5.5%, 95% CI: 4.3%–6.9%) of the jaundiced infants died. Weight on admission, peak total serum bilirubin (TSB), sepsis and exposure to hemolytic products were predictive of ABE, while age on admission, peak TSB, ABO incompatibility and ABE were predictive of ET. Rhesus incompatibility, asphyxia, exposure to hemolytic substances and ABE were associated with elevated mortality risk, while ET was a protective factor. Lack of routine irradiance monitoring and steady energy supply were frequent challenges for conventional blue-light phototherapy.Conclusions
Severe hyperbilirubinemia is associated with high rates of ABE and ET in this setting, and remains a significant contributor to neonatal admissions and mortality. To be impactful, FSPT, complemented with improved diagnostic facilities, should effectively curtail jaundice-related adverse outcomes in this and comparable settings. 相似文献86.
Marina Allegrezza Silvia Montecchiari Cecilia Ottaviani Veronica Pelliccia Giulio Tesei 《Plant biosystems》2019,153(4):616-623
This study presents the results of a floristic vegetational study on Robinia pseudoacacia neoformation forests in the peri-Adriatic sector of central Italy. This has allowed the characterization of these coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These currently represent the southernmost syntaxa of the Robinietea class described for the Italian peninsula, and the first syntaxonomic contribution of this class in Europe for the Mediterranean biogeographical region. We propose here the new alliance Lauro nobilis–Robinion pseudoacaciae of the order Chelidonio–Robinietalia pseudoacaciae and class Robinietea, with two new associations: Melisso altissimae–Robinietum pseudoacaciae and Rubio peregrinae–Robinietum pseudoacaciae. The new alliance Lauro nobilis–Robinion pseudoacaciae (typus: Melisso altissimae–Robinietum pseudoacaciae) brings together neoformation forests and pre-forest dominated by R. pseudoacacia in those territories with a Mediterranean macroclimate of the peri-Adriatic sector of central Italy. The optimum is found for the alluvial plain and low-slope morphologies, on soils that are moist and rich in organic matter and in areas with anthropic disturbance. On the basis of comparisons with the European context, the alliance Bryonio–Robinion described for the temperate territories of northern Italy is here validated. 相似文献
87.
Acrylic bone cements are widely used for fixation of joint prostheses as well as for vertebral body augmentation procedures of vertebroplasty and balloon kyphoplasty, with the cement zone(s) being subjected to repeated mechanical loading in each of these applications. Although, in vertebroplasty and balloon kyphoplasty, the cement zone is exposed to mainly cyclical compressive load, the compressive fatigue properties of acrylic bone cements used in these procedures are yet to be determined. The purposes of the present study were to determine the compressive fatigue properties of a commercially available cement brand used in vertebroplasty, including the effect of frequency on these properties; to identify the cement failure modes under compressive cyclical load; and to introduce a screening method that may be used to shorten the lengthy character of the standardized fatigue tests. Osteopal \({^\circledR } \mathrm{V}\) was used as the model cement in this study. The combinations of maximum stress and frequency used were 50.0, 55.0, 60.0, 62.5 and 75.5 MPa at 2 Hz; and of 40.0, 55.0, 60.0, 62.5 or 75.5 MPa at 10 Hz. Through analysis of nominal strain-number of loading cycles results, three cement failure modes were identified. The estimated mean fatigue limit at 2 Hz (55.4 MPa) was significantly higher than that at 10 Hz (41.1 MPa). The estimated fatigue limit at 2 Hz is much higher than stresses commonly found in the spine and also higher than that for other acrylic bone cements tested in a full tension–compression fatigue test, which indicates that tension–compression fatigue testing may substantially underestimate the performance of cements intended for vertebroplasty. A screening method was introduced which may be used to shorten the time spent in performing compressive fatigue tests on specimens of acrylic bone cement for use in vertebral body augmentation procedures. 相似文献
88.
Valentina Vernocchi Maria Giorgia Morselli Sara Varesi Simona Nonnis Elisa Maffioli Armando Negri Gabriella Tedeschi Gaia Cecilia Luvoni 《Theriogenology》2014
Ubiquitin is a 8.5-kDa peptide that tags other proteins for proteasomal degradation. It has been proposed that ubiquitination might be responsible for the elimination of defective spermatozoa during transit through the epididymis in humans and cattle, but its exact biological function in seminal plasma has not yet been clarified. In the domestic cat (Felis catus), the percentage of immature, unviable, and abnormal spermatozoa decreases during the epididymal transit, indicating the existence of a mechanism that removes defective spermatozoa. Magnetic cell separation techniques, based on the use of magnetic beads coated with anti-ubiquitin antibodies, may allow the selective capture of ubiquitinated spermatozoa from semen, thus contributing to the identification of a potential correlation between semen quality and ubiquitination process. Moreover, the selective identification of all the ubiquitinated proteins in different epididymal regions could give a better understanding of the ubiquitin role in feline sperm maturation. The aims of this study were as follows: (1) to verify the possibility of separating ubiquitinated spermatozoa with magnetic ubiquitin beads and identify the morphological and acrosomal differences between whole sample and unbound gametes, (2) to characterize all the ubiquitinated proteins in spermatozoa retrieved in the three epididymal regions by a proteomic approach. The data indicated the presence of ubiquitinated proteins in cat epididymal semen. However, a correlation between abnormal and ubiquitinated spermatozoa has not been found, and ubiquitin cannot be considered as a biomarker of quality of epididymal feline spermatozoa. To the author's knowledge, this is the first identification of all the ubiquitinated proteins of cat spermatozoa collected from different epididymal regions. The proteomic pattern allows a further characterization of cat epididymal semen and represents a contribute to a better understanding of the ubiquitin role in feline sperm maturation. 相似文献
89.
23Na nuclear magnetic resonance (NMR) has previously been used to monitor Na+ translocation across membranes in gram-negative bacteria and in various other organelles and liposomes using a membrane-impermeable shift reagent to resolve the signals resulting from internal and external Na+. In this work, the 23Na NMR method was adapted for measurements of internal Na+ concentration in the gram-positive bacterium Bacillus subtilis, with the aim of assessing the Na+ translocation activity of the Mrp (multiple resistance and pH) antiporter complex, a member of the cation proton antiporter-3 (CPA-3) family. The sodium-sensitive growth phenotype observed in a B. subtilis strain with the gene encoding MrpA deleted could indeed be correlated to the inability of this strain to maintain a lower internal Na+ concentration than an external one. 相似文献
90.
Fed‐batch synthesis of galacto‐oligosaccharides with Aspergillus oryzae β‐galactosidase using optimal control strategy 下载免费PDF全文
Fed‐batch synthesis of galacto‐oligosaccharides (GOS) from lactose with β‐galactosidase from Aspergillus oryzae was evaluated experimentally and reaction yield was maximized via optimal control technique. The optimal lactose and enzyme feed flow rate profiles were determined using a model for GOS synthesis previously reported by the authors. Experimentally it was found that fed‐batch synthesis allowed an increase on the maximum total GOS concentration from 115 (batch synthesis) to 218 g L?1 as consequence of the increase in total sugars concentration from 40 to 58% w/w. Such high concentration of total sugars was not attainable in batch operation because of the low solubility of lactose at the reaction temperature (40°C). Simulations predicted a GOS yield of 32.5 g g?1 in fed‐batch synthesis under optimal conditions, while experimentally the same yield as in batch synthesis was obtained (28 g g?1). Besides, an enrichment of total oligosaccharides in GOS with a high polymerization degree (GOS‐5 and GOS‐6) was observed in the fed‐batch synthesis. Experimental profiles for all sugars were similar to the ones predicted by simulation, which supports the use of this methodology for the optimization of GOS synthesis. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 30:59–67, 2014 相似文献