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81.
Nefedova VV Korenberg EI Nesterenko LN Gintsburg AL Kovalevskiĭ IuV Gorelova NB 《Parazitologiia》2001,35(1):3-8
Indication of Borrelia (B. burgdorferi sensu lato) in 205 adult unfed I. persulcatus ticks from a natural focus was carried out simultaneously by methods of PCR and dark-field microscopy of vital preparations. PCR method revealed Borrelia prevalence in considerable number of ticks, in which Borrelia were not found by microscopy of 250 microscopic fields in a preparation from each individual tick. At the same time, PCR method didn't give positive results for approximately 8% of ticks, which contained rather high concentration of Borrelia (more than 10 per 100 microscopic fields). In general, PCR method doesn't have advantages in comparison with a microscopy of vital preparations for study the Borrelia prevalence in ticks. 相似文献
82.
The body-wall musculature of invasive cercariae and metacercariae of Diplostomum chromatophorum at different intervals after the penetration into the experimental intermediate host Cyprinus carpio (1, 3, 5, 6, 7, 10, 12, 20, 34, 40 days) has been investigated with the help of TEM technique. During the first 10 days after the invasion (in conditions of our experiment), the cercarial subtegumental muscle fibres degenerate. These muscles are replaced by newly formed ones. Mass differentiation of myoblasts beneath the tegument was observed in 7-10-day-old metacercariae. Obtained data indicate the metamorphosis of body-wall musculature during the morphogenesis in Diplostomum chromatophorum metacercariae. 相似文献
83.
Mikheev AN Gushcha NI Malinovskiĭ IuIu 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》1999,39(5):548-556
The importance of radiation modification of epigenetic activity in the general mechanism of radiobiological reactions is proved. The inheritable epigenetic changes induced by irradiation are one of the basic reasons of formation of the remote radiation pathology. It is noted that epigenetic inheritable changes of cells have the determined character distinguishing them from mutation changes, being individual and not directed. It is underlined the ability of ionizing radiation to modify a level of spontaneous genetic instability inherited in a number of cell generations on the epigenetic mechanism. 相似文献
84.
Aniukhovskiĭ EP Rozenshtraukh LV 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》1999,85(7):918-930
The ACh shortened the AP in canine epicardial and endocardial cells, the effect being more obvious in the latter. The findings suggest that 4-aminophyridine-sensitive transient outward current is expressed in canine atrial epicardial and endocardial cells, that the ACh exerts direct effects on epicardial and endocardial AP duration, that differential responses of epicardial and endocardial AP duration to the ACh may alter the gradient of repolarisation across the atrial wall and contribute to the vagus-indoced atrial flutter and fibrillation. 相似文献
85.
Kuz'min AI Kalenikova EI Zaretskaia MV Zaretskiĭ DV Zakharova NV Medvedev OS Chazov EI 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》1999,85(7):867-877
Physostigmine and an 1-hour immobilisation stress similarly affected functions of the sympatho-adrenal and cardiovascular systems activating the catecholamine secretion and increasing the blood pressure. Yohimbine potentiated the secretory effect but did not change the pressor effect. Intermediate administration of atropine completely eliminated both effects of physostigmine but, being administered prior to the immobilisation, it potentiated the secretory response without affecting the pressor response. The findings reveal a difference in central cholinergic mechanisms of neurohumoral and haemodynamic responses to physostigmine and stress. 相似文献
86.
Osadchiĭ OE Pokrovskiĭ VM 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》1999,85(8):1051-1059
In anaesthetised cats, effects of 24 regulatory peptides upon inhibitory tonic and synchronizing components of vagal chronotropic action, were studied. The findings allowed to divide the peptidergic vagotropic activity into three types: (1) a selective action upon inhibitory tonic vagal effect; (2) a selective modulation of synchronizing vagal effect; (3) opposite changes in the vagal chronotropic effect components. The peptides seem to be able to modulate both the vagal bradycardia and the functional structure of parasympathetic chronotropic effect. 相似文献
87.
88.
The effect of temperature, nutrition, and density stresses on phenotypic and genetic variation in morphological traits (thorax length, wing length, number of sternopleural and abdominal bristles, and number of arista branches) was examined in Drosophila melanogaster. In addition, the effect of stress on developmental stability measured as fluctuation asymmetry of bilateral traits was analyzed. All of the stresses were shown to increase phenotypic variation and fluctuating asymmetry of bilateral traits. Genetic variation of morphometric traits estimated using the isofemale line technique was higher under stressful than under normal conditions. Biotic and abiotic stresses were similar in their effect on phenotypic and genetic variation. The effect of stress on variability of morphometric traits was generally higher than on that of meristic traits. Possible causes of the increase of genetic variation under stress are discussed. 相似文献
89.
Beijerinckia mobilis 1f capable of degrading polycyclic aromatic hydrocarbons (PAHs) was isolated from a soil contaminated with creosote. Strain 1f could utilize phenanthrene and naphthalene as the sole sources of carbon. The mean rate of phenanthrene degradation during culture growth was 7-8 micrograms/(ml h). After cultivation under nonselective conditions, strain 1f retained its ability to degrade phenanthrene. Cometabolism considerably widened the range of PAHs that could be transformed by strain 1f. The strain was able to grow in a mineral medium with creosote as the sole source of carbon. After 30 days of cultivation in this medium, the total concentration of PAHs decreased from 665.5 mg/l to 170 mg/l. 相似文献
90.