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121.
Barros RC Abe AS Cárnio EC Branco LG 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2004,138(1):97-104
Burrowing mammals usually have low respiratory sensitivity to hypoxia and hypercapnia. However, the interaction between ventilation (V), metabolism and body temperature (Tb) during hypoxic-hypercapnia has never been addressed. We tested the hypothesis that Clyomys bishopi, a burrowing rodent of the Brazilian cerrado, shows a small ventilatory response to hypoxic-hypercapnia, accompanied by a marked drop in Tb and metabolism. V, Tb and O(2) consumption (V?O(2)) of C. bishopi were measured during exposure to air, hypoxia (10% and 7% O(2)), hypercapnia (3% and 5% CO(2)) and hypoxic-hypercapnia (10% O(2)+ 3% CO(2)). Hypoxia of 7% but not 10%, caused a significant increase in V, and a significant drop in Tb. Both hypoxic levels decreased V?O(2) and 7% O(2) significantly increased V/V?O(2). Hypercapnia of 5%, but not 3%, elicited a significant increase in V, although no significant change in Tb, V?O(2) or V/V?O(2) was detected. A combination of 10% O(2) and 3% CO(2) had minor effects on V and Tb, while V?O(2) decreased and V/V?O(2) tended to increase. We conclude that C. bishopi has a low sensitivity not only to hypoxia and hypercapnia, but also to hypoxic-hypercapnia, manifested by a biphasic ventilatory response, a drop in metabolism and a tendency to increase V/V?O(2). The effect of hypoxic-hypercapnia was the summation of the hypoxia and hypercapnia effects, with respiratory responses tending to have hypercapnic patterns while metabolic responses, hypoxic patterns. 相似文献
122.
Hoyer J Ekici AB Endele S Popp B Zweier C Wiesener A Wohlleber E Dufke A Rossier E Petsch C Zweier M Göhring I Zink AM Rappold G Schröck E Wieczorek D Riess O Engels H Rauch A Reis A 《American journal of human genetics》2012,90(3):565-572
Intellectual disability (ID) is a clinically and genetically heterogeneous common condition that remains etiologically unresolved in the majority of cases. Although several hundred diseased genes have been identified in X-linked, autosomal-recessive, or syndromic types of ID, the establishment of an etiological basis remains a difficult task in unspecific, sporadic cases. Just recently, de novo mutations in SYNGAP1, STXBP1, MEF2C, and GRIN2B were reported as relatively common causes of ID in such individuals. On the basis of a patient with severe ID and a 2.5 Mb microdeletion including ARID1B in chromosomal region 6q25, we performed mutational analysis in 887 unselected patients with unexplained ID. In this cohort, we found eight (0.9%) additional de novo nonsense or frameshift mutations predicted to cause haploinsufficiency. Our findings indicate that haploinsufficiency of ARID1B, a member of the SWI/SNF-A chromatin-remodeling complex, is a common cause of ID, and they add to the growing evidence that chromatin-remodeling defects are an important contributor to neurodevelopmental disorders. 相似文献
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124.
Gruno M Peet N Seppet E Kadaja L Paju K Eimre M Orlova E Peetsalu M Tein A Soplepmann J Schlattner U Peetsalu A Seppet EK 《American journal of physiology. Regulatory, integrative and comparative physiology》2006,291(4):R936-R946
Energy metabolism in gastrobiopsy specimens of the antral and corpus mucosa, treated with saponin to permeabilize the cells, was studied in patients with gastric diseases. The results show twice lower oxidative capacity in the antral mucosa than in the corpus mucosa and the relative deficiency of antral mitochondria in complex I. The mucosal cells expressed mitochondrial and cytosolic isoforms of creatine kinase and adenylate kinase (AK). Creatine (20 mM) and AMP (2 mM) markedly stimulated mitochondrial respiration in the presence of submaximal ADP or ATP concentrations, and creatine reduced apparent Km for ADP in stimulation of respiration, which indicates the functional coupling of mitochondrial kinases to oxidative phosphorylation. Addition of exogenous cytochrome c increased ADP-dependent respiration, and the large-scale cytochrome c effect (>or=20%) was associated with suppressed stimulation of respiration by creatine and AMP in the mucosal preparations. These results point to the impaired mitochondrial outer membrane, probably attributed to the pathogenic effects of Helicobacter pylori. Compared with the corpus mucosa, the antral mucosa exhibited greater sensitivity to such type of injury as the prevalence of the large-scale cytochrome c effect was twice higher among the latter specimens. Active chronic gastritis was associated with decreased respiratory capacity of the corpus mucosa but with its increase in the antral mucosa. In conclusion, human gastric mucosal cells express the mitochondrial and cytosolic isoforms of CK and AK participating in intracellular energy transfer systems. Gastric mucosa disease is associated with the altered functions of these systems and oxidative phosphorylation. 相似文献
125.
Background
Salt stress has become a major threat to plant growth and productivity. Arbuscular mycorrhizal fungi colonize plant root systems and modulate plant growth in various ways.Scope
This review addresses the significance of arbuscular mycorrhiza in alleviation of salt stress and their beneficial effects on plant growth and productivity. It also focuses on recent progress in unravelling biochemical, physiological and molecular mechanisms in mycorrhizal plants to alleviate salt stress.Conclusions
The role of arbuscular mycorrhizal fungi in alleviating salt stress is well documented. This paper reviews the mechanisms arbuscular mycorrhizal fungi employ to enhance the salt tolerance of host plants such as enhanced nutrient acquisition (P, N, Mg and Ca), maintenance of the K+ : Na+ ratio, biochemical changes (accumulation of proline, betaines, polyamines, carbohydrates and antioxidants), physiological changes (photosynthetic efficiency, relative permeability, water status, abscissic acid accumulation, nodulation and nitrogen fixation), molecular changes (the expression of genes: PIP, Na+/H+ antiporters, Lsnced, Lslea and LsP5CS) and ultra-structural changes. Theis review identifies certain lesser explored areas such as molecular and ultra-structural changes where further research is needed for better understanding of symbiosis with reference to salt stress for optimum usage of this technology in the field on a large scale. This review paper gives useful benchmark information for the development and prioritization of future research programmes.Key words: Arbuscular mycorrhizal fungi, salt stress, PIP, Na+/H+ antiporters, nutrient uptake, soil salinity 相似文献126.
Stefan Georg Michalski Walter Durka Anke Jentsch Juergen Kreyling Sven Pompe Oliver Schweiger Evelin Willner Carl Beierkuhnlein 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(6):1151-1162
The use of local provenances in restoration, agriculture and forestry has been identified as measure to sustain biological
diversity and to improve local productivity. However, the delineation of regional provenances is challenging because it requires
the identification of well-defined groups based on spatiogenetic differentiation and/or the evidence of local adaptation.
In this study, we investigate genetic variation at 186 AFLP loci in 46 European accessions of the important grassland species
Arrhenatherum elatius and ask (1) whether genetic variation within accessions differs between European geographical regions; (2) at which spatial
scale populations are structured across Europe and (3) whether putatively adaptive markers contribute to this pattern and
whether these markers can be related to climatic site conditions. Basic expectations of population genetics are likely to
be altered in autotetraploid species, thus, we adopted a band-based approach to estimate genetic diversity and structuring.
Compared to other grasses A. elatius showed high genetic diversity and considerable differentiation among accessions (ΦST = 0.24). Accessions separated in a Western European and a Central/Eastern European group, without further structure within
groups. A genome scan approach identified four potentially adaptive loci, whose band frequencies correlated significantly
with climatic parameters, suggesting that genetic differentiation in A. elatius is also the result of adaptive processes. Knowledge on adaptive loci might in the long run also help to adapt ecosystems
to adverse climate change effects through assisted migration of ecotypes rather than introduction of new species. 相似文献
127.
Evelin Witkowska Krzysztof Niciski Dorota Korsak Bartomiej Dominiak Jacek Waluk Agnieszka Kamiska 《Journal of biophotonics》2020,13(5)
According to EU summary report on zoonoses, zoonotic agents and food‐borne outbreaks in 2017, Campylobacter was the most commonly reported gastrointestinal bacterial pathogen in humans in the EU. Unfortunately, the standard methods for the detection of thermotolerant Campylobacter spp. in foods are time‐consuming. Additionally, the qualified staff is obligatory. For this reason, new methods of pathogens detection are needed. The present work demonstrates that surface‐enhanced Raman scattering (SERS) is a reliable and fast method for detection of Campylobacter spp. in food samples. The proposed method combines the SERS measurements performed on an Ag/Si substrate with two initial steps of the ISO standard procedure. Finally, the principal component analysis (PCA) allows for statistical classification of the studied bacteria. By applying the proposed ISO‐SERS‐PCA method in the case of Campylobacter bacteria the total detection time may be reduced from 7 to 8 days required by ISO method to 3 to 4 days in the case of SERS‐based approach. 相似文献