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151.
N. K. Belisheva A. A. Martynova S. V. Pryanichnikov N. L. Solov’evskaya R. E. Mikhailov 《Human physiology》2016,42(2):156-168
The results of analysis of specific characteristics of the heart rate variability (HRV) regulation in preschool children living under the Arctic high-latitude conditions are presented. The principal ageand gender-specific differences in the HRV regulation have been inferred from the intergroup evaluations of the HRV indicators in boys and girls. A functional developmental delay has been shown in 2.5-year-old girls compared with boys of the same age group. The applied orthostatic test has shown lower reserve capacities in children of the senior group compared with the junior group. It has been shown that the mechanisms of the regulation of cardiac rhythm in girls experience higher strain during orthostasis as compared with boys. The division of children into age groups with an age difference of one year has allowed the detection of the tendency towards basically different responses to functional loads during orthostasis. The mean HRV values characteristic of four- to six-year-old children living in the Arctic are presented. It has been shown that the children living at middle latitudes have a higher adaptive potential compared with the children living in high-latitude Arctic areas. 相似文献
152.
MG Oliveira Alves CFL Carta M-E Padín-Iruegas M Pérez-Sayáns JM Suarez-Peñaranda JS Issa 《Biotechnic & histochemistry》2016,91(4):263-268
We investigated the gene and protein expressions of V-type ATPase protein subunit C1 (ATP6V1C1) in cases of oral squamous cell carcinoma (OSCC) and contralateral normal mucosa in smokers, nonsmokers and former smokers. Subjects were separated into five groups of 15: group 1, smokers with OSCC; group 2, normal contralateral mucosa of OSCC patients; group 3, chronic smokers; group 4, former smokers who had stopped smoking 1 year earlier; group 5, individuals who had never smoked. Exfoliative cytology specimens from oral mucosa of smokers, former smokers and nonsmokers showed normal gene and protein expression. We found significantly greater gene expression in the OSCC group than in the nonsmoker groups. No difference in gene expression was observed between normal contralateral mucosa and nonsmoker groups, smoker and nonsmoker groups or former smoker and nonsmoker groups. We observed intense immunostaining for ATP6V1C1 protein in all cases of OSCC and weak or no staining in smoker, former smoker and nonsmoker groups. Significantly greater expression of ATP6V1C1 protein was observed in the OSCC group compared to the other groups, which supports the role of ATP6V1C1 in effecting changes associated with oral cancer. Analysis of the mucosae of chronic smokers, former smokers and the normal contralateral mucosa of patients with OSCC showed unaltered ATP6V1C1 gene and protein expression. Early stages of carcinogenesis, represented by altered epithelium of chronic smokers, had neither gene nor protein alterations as seen in OSCC. Therefore, we infer that the changes in ATP6V1C1 occur during later stages of carcinogenesis. Our preliminary study provides a basis for future studies of using ATP6V1C1 levels for detecting early stage OSCC. 相似文献
153.
The interaction between mouse angora-Y (Fgf5 go-Y) and hairless (hr) genes have been studied. Homozygous mutant gene Fgf5 go-Y increases length of all hair types, while homozygotes for the h gene lose hair completely starting on day 14 after birth. We obtained mice with genotypes +/+ hr/hr F2, +/Fgf5 go-Y hr/hr and Fgf5 go-Y/Fgf5 go-Y hr/hr. Both +/Fgf5 go-Y hr/hr and +/+ hr/hr mice began to loose hair from their heads on day 14. This further extended on the whole body. On day 21 the mice were completely deprived of hair. Therefore a single dose of gene Fgf5 go-Y does not modify alopecia in mice homozygous for hr. However in double homozygotes Fgf5 go-Y/Fgf5 go-Y hr/hr alopecia started 4 days later, namely on day 18. It usually finished 10–12 days after detection of first bald patches. On days 28–30 double homozygotes lose coat completely. Hair loss in double homozygous mice was 1.5-fold slower than in +/+ hr/hr mice. This resulted from a significant extension of anagen phase induced by a mutant homozygous gene Fgf5 go-Y in morphogenesis of the hair follicle. The hr gene was expressed at the transmission phase from anagen to catagen. Our data shows that the angora gene is a modifier of the hairless gene and this results in a strong repression of alopecia progression in double homozygous mice compared to +/+ hr/hr animals. 相似文献
154.
Demonstration of spontaneous chiral symmetry breaking in asymmetric Mannich and Aldol reactions 总被引:1,自引:0,他引:1
Spontaneous symmetry breaking in reactive systems, known as a rare physical phenomenon and for the Soai autocatalytic irreversible reaction, might in principle also occur in other, more common asymmetric reactions when the chiral product is capable to promote its formation and an element of "nonlinearity" is involved in the reaction scheme. Such phenomena are long sought after in chemistry as a possible explanation for the biological homochirality of biomolecules. We have investigated homogeneous organic stereoselective Mannich and Aldol reactions, in which the product is capable to form H-bridged complexes with the prochiral educt, and found by applying NMR spectroscopy, HPLC analysis, and optical rotation measurements 0.3-50.8% of random product enantiomeric excess under essentially achiral reaction conditions. These findings imply a hitherto overlooked mechanism for spontaneous symmetry breaking and, hence, a novel approach to the problem of absolute asymmetric synthesis and could have also potential significance for the conundrum of homochirality. 相似文献
155.
Equine arteritis virus (EAV) induces apoptosis in infected cells. Cell death caused by EAV has been studied mainly using three cell lines, BHK-21, RK-13 and Vero cells. The mechanism of apoptosis varies among cell lines and results cannot be correlated owing to differences in EAV strains used. We evaluated different markers for apoptosis in BHK-21, RK-13 and Vero cell lines using the Bucyrus EAV reference strain. Acridine orange/ethidium bromide staining revealed morphological changes in infected cells, while flow cytometry indicated the extent of apoptosis. We also observed DNA fragmentation, but the DNA ladder was detected at different times post-infection depending on the cell line, i.e., 48, 72 and 96 h post-infection in RK-13, Vero and BHK-21 cells, respectively. Measurement of viral titers obtained with each cell line indicated that apoptosis causes interference with viral replication and therefore decreased viral titers. As an unequivocal marker of apoptosis, we measured the expression of caspase-3 and caspases-8 and -9 as extrinsic and intrinsic markers of apoptosis pathways, respectively. Caspase-8 in BHK-21 cells was the only protease that was not detected at any of the times assayed. We found that Bucyrus EAV strain exhibited a distinctive apoptosis pathway depending on the cell line. 相似文献
156.
E Iu Bychkova E R Martynova O S Medvedev V P Krotov F E Meertsuk 《Biulleten' eksperimental'no? biologii i meditsiny》1990,109(1):20-23
The systemic and regional hemodynamics during antiorthostatic hypokinesia were studied in male Wistar rats using the radioactive microsphere technique. The animals were hanged up by the tail with the head tilted down (30 degrees) and were able to exercise using only front limbs. Twenty four hours long exposure to antiorthostasis induced significant changes in systemic hemodynamics as well as in regional blood flow in skeletal muscles, spleen, liver and pancreas. Antiorthostasis induced blood flow changes in lungs, heart and brain were less pronounced. 相似文献
157.
V Iu Khalatov E R Martynova R S Akchurin O S Medvedev 《Biulleten' eksperimental'no? biologii i meditsiny》1990,110(12):586-588
Hemodynamics of intra-abdominally transplanted rat heart was studied. Investigations were performed on 14 rats 7 to 260 days after transplantation. Significant changes revealed included increase in coronary vascular resistance and decrease in coronary blood flow and left ventricular contractility. These hemodynamic changes are ascribed to total denervation of the transplanted heart, absence of pump function and asynchronous contractions of transplanted and recipient hearts. 相似文献
158.
杨善元 《植物生理与分子生物学学报》1989,15(1):83-87
叶绿素b由单体聚合成多聚体后吸收光谱明显红移。叶绿素b聚集体膜在光下产生150 mV的光电位,停止照光后此电位消失速度比叶绿素a聚集体膜的慢。叶绿素b聚集体吸收光能后形成相当稳定的能化态,半生命期约几分钟。当聚集体解聚时所吸收的光能又以光的形式辐射出来。叶绿素b聚集体能化态的能量可快速而有效地传给叶绿素a聚集体,以叶绿素a的延迟发光形式释放出来。 相似文献
159.
160.
Phylogenetic relationships among prokaryotic and eukaryotic catalases 总被引:13,自引:1,他引:12
Seventy-four catalase protein sequences, including 29 bacterial, 8 fungal,
7 animal, and 30 plant sequences, were compiled, and 70 were used for
phylogenetic reconstruction. The core of the resulting tree revealed
unique, separate groups of plant and animal catalases, two groups of fungal
catalases, and three groups of bacterial catalases. The only overlap of
kingdoms occurred within one branch and involved fungal and bacterial
large-subunit enzymes. The other fungal branch was closely linked to the
group of animal enzymes. Group I bacterial catalases were more closely
related to the plant enzymes and contained such diverse taxa as the
Gram-positive Listeria seeligeri, Deinocococcus radiodurans, and
gamma-proteobacteria. Group III bacterial sequences were more closely
related to fungal and animal sequences and included enzymes from a broad
range of bacteria including high- and low-GC Gram positives,
proteobacteria, and a bacteroides species. Group II was composed of
large-subunit catalases from diverse sources including Gram positives
(low-GC Bacilli and high-GC Mycobacteria), proteobacteria, and species of
the filamentous fungus Aspergillus. These data can be interpreted in terms
of two gene duplication events that produced a minimum of three catalase
gene family members that subsequently evolved in response to environmental
demands. Horizontal gene transfer may have been responsible for the group
II mixture of bacterial and fungal large-subunit catalases.
相似文献