Hemodynamic component in cerebral compensatory processes following unilateral exclusion of the somatosensory cortex]

In experiments on anesthetised and awake cats the dynamics of the cerebral blood flow was studied by the thermoelectric method in one hemisphere in experimental lesion of the somatosensory zone of the opposite one. Temporary exclusion of the cortical area by cold produced evident hemodynamic changes, i. e. a two-phase vasoreaction and an initial blood flow decrease followed by a prolonged increase of blood supply, in the other hemisphere. Analogous vasoreactions were seen on unilateral extirpation of the cortical layer of the somatosensory zone, as well. Such vasoreactions indicate enhanced activity of the cortical structures in the intact hemisphere and may be considered as a compensatory reaction to the local lesion of certain cortical areas.     

Age-related changes to adipose tissue and peripheral neuropathy in genetically diverse HET3 mice differ by sex and are not mitigated by rapamycin longevity treatment

Neural communication between the brain and adipose tissues regulates energy expenditure and metabolism through modulation of adipose tissue functions. We have recently demonstrated that under pathophysiological conditions (obesity, diabetes, and aging), total subcutaneous white adipose tissue (scWAT) innervation is decreased (‘adipose neuropathy’). With advanced age in the C57BL/6J mouse, small fiber peripheral nerve endings in adipose tissue die back, resulting in reduced contact with adipose-resident blood vessels and other cells. This vascular neuropathy and parenchymal neuropathy together likely pose a physiological challenge for tissue function. In the current work, we used the genetically diverse HET3 mouse model to investigate the incidence of peripheral neuropathy and adipose tissue dysregulation across several ages in both male and female mice. We also investigated the anti-aging treatment rapamycin, an mTOR inhibitor, as a means to prevent or reduce adipose neuropathy. We found that HET3 mice displayed a reduced neuropathy phenotype compared to inbred C56BL/6 J mice, indicating genetic contributions to this aging phenotype. Compared to female HET3 mice, male HET3 mice had worse neuropathic phenotypes by 62 weeks of age. Female HET3 mice appeared to have increased protection from neuropathy until advanced age (126 weeks), after reproductive senescence. We found that rapamycin overall had little impact on neuropathy measures, and actually worsened adipose tissue inflammation and fibrosis. Despite its success as a longevity treatment in mice, higher doses and longer delivery paradigms for rapamycin may lead to a disconnect between life span and beneficial health outcomes.     

Determination of metabolic resistance mechanisms in pyrethroid‐resistant and fipronil‐tolerant brown dog ticks

Rhipicephalus sanguineus (Latreille) (Ixodida: Ixodidae) is a three‐host dog tick found worldwide that is able to complete its' entire lifecycle indoors. Options for the management of R. sanguineus are limited and its' control relies largely on only a few acaricidal active ingredients. Previous studies have confirmed permethrin resistance and fipronil tolerance in R. sanguineus populations, commonly conferred by metabolic detoxification or target site mutations. Herein, five strains of permethrin‐resistant and three strains of fipronil‐tolerant ticks were evaluated for metabolic resistance using synergists to block metabolic enzymes. Synergist studies were completed with triphenyl phosphate (TPP) for esterase inhibition, piperonyl butoxide (PBO) for cytochrome P450 inhibition, and diethyl maleate (DEM) for glutathione‐S‐transferase inhibition. Additionally, increased esterase activity was confirmed using gel electrophoresis. The most important metabolic detoxification mechanism in permethrin‐resistant ticks was increased esterase activity, followed by increased cytochrome P450 activity. The inhibition of metabolic enzymes did not have a marked impact on fipronil‐tolerant tick strains.     

Effect of hyperbaric factors on the biochemical and hematological indicators in rats (in vivo) and in humans (in vitro)]

The influence of hyperbaric factors on complex of biochemical and haematological parameters was examined in rats (in vivo) on donor blood samples. It was established, that the sojourn in heliox under the pressure 6.1 MPa and rO2 60 kPa results in activation of lipid peroxidation, alteration of erythrocyte oxygen transport function and the suppression of lipid metabolism. There are no significant alterations of these parameters in the comparative experiment with the pO2 40 kPa. The decompression of donor blood samples from 5.1 MPa to 0.1 MPa during 50 minutes had no significant influence on complex of biochemical, haematological and immunological parameters as compared to control probes.     

Various mechanisms of regulation of lipid peroxidation in human erythrocytes after long-term exposure to hyperbaric oxygenation]

Intensity of lipid peroxidation and activity of antioxidant protection enzymes in erythrocytes were measured in three experiments with 10-24 days exposure of aquanauts under 4.6 and 5.1 MPa. It is established that there is no pathological intensification of lipid peroxidation when oxygen partial pressure in breathing gas mixture is optimal. This process is under reliable control by modulation of antioxidant enzymes activity. The high sensitivity of these research methods allows using them to determine exposure limitations under high pressure and optimal oxygen concentrations in breathing gas mixture.     

Characterization of the trnL-trnF spacer sequence of the chloroplast tRNA genes in Spirodela species

The trnL-trnF spacer region of the chloroplast tRNA genes was sequenced and characterized in 14 accessions of the genus Spirodela (Lemnaceae). Only a low intraspecific variation of the spacer was observed in geographically isolated and morphologically different accessions of S. polyrrhiza, the most widespread Spirodela species. Five haplotypes of the spacer were identified, differing in mono-and oligonucleotide repeats and extended indels, specific to S. polyrrhiza, Landoltia punctata, and Lemna sp. The result supported the isolation of Landoltia from Spirodela.