Accelerated cross-linking technique using a protective corneal donor flap in the treatment of progressive keratoconus on «thin» corneas

Purpose. To develop a method of accelerated ultraviolet crosslinking with an initial corneal thickness equal to or less than 400 microns using a protective donor corneal flap. Definition of safety and effectiveness of this method in the treatment of progressive keratoconus.Material and methods. 20 patients (20 eyes) with a diagnosis of progressive keratoconus 2–3 stages were included in the study. The accelerated crosslinking was carried out with an IROC-VX-2000 device (Switzerland). A protective donor corneal flap was cut out by using a Femto LDV Z8 femtosecond laser («Ziemer», Switzerland). The thickness of the protective flap of the donor cornea was determined as the difference between 450 μm and the obtained value of the patient’s pachymetry in 30 minutes of saturation with Dextralink in μm.Results. Indicators of uncorrected visual acuity and corrected visual acuity returned to the level of preoperative values and did not tend to decrease until the end of the observation period for 6 months. The average keratometry indices gradually decreased: after 3 months – 50.3±1.5 μm, after 6 months – 48.9±1.8 μm, by 12 months – 46.7±2.1 μm. A decrease in elevation indicators of the anterior and posterior surfaces was marked on elevation maps throughout the observation period.Conclusion. The proposed ultraviolet crosslinking technique using a protective donor corneal flap in patients with corneal thickness 400 μm or less is reproducible. This technique proves its effectiveness and safety and allows to stabilize the condition in patients with progressive keratoconus with adequate visual function. This makes this technique necessary, taking into account the lack of adequate cross-linking technology with a thin cornea

Alkaloid content variability in the seeds of narrow-leafed lupine accessions from the VIR collection under the conditions of the Russian Northwest

Alkaloid content was assessed in the seeds of 59 narrow-leafed lupine (Lupinus angustifolius L.) accessions from the VIR collection in the environments of Leningrad Province. The selected set included accessions of different statuses (wild forms, landraces, and advanced cultivars) and different years of introduction to the collection. Alkaloids were analyzed using gas-liquid chromatography coupled with mass spectrometry. Concentrations of main alkaloids: lupanine, 13-hydroxylupanine, sparteine, angustifoline and isolupanine, and their total content were measured. The total alkaloid content variability identified in the seeds of the studied set of accessions was 0.0015 to 2.017 %. In most cases, the value of the character corresponded to the accession’s status: modern improved cultivars, with the exception of green manure ones, entered the group with the range of 0.0015–0.052 %, while landraces and wild forms showed values from 0.057 to 2.17 %. It is meaningful that the second group mainly included accessions that came to the collection before the 1950s, i. e., before the times when low-alkaloid cultivars were intensively developed. Strong variability of the character across the years was observed in the accessions grown under the same soil and climate conditions in both years. In 2019, the average content of alkaloids in the sampled set was 1.9 times higher than in 2020. An analysis of weather conditions suggested that the decrease in alkaloid content occurred due to a significant increase in total rainfall in 2020. Searching for links between the content of alkaloids and the type of pod (spontaneously non-dehiscent, or cultivated, spontaneously dehiscent, or wild, and intermediate) showed a tendency towards higher (approximately twofold in both years of research) total alkaloid content in the accessions with the wild pod type and the nearest intermediate one compared to those with the pod non-dehiscent without threshing. The correlation between the average total alkaloid content and seed color, reduced to three categories (dark, or wild, light, or cultivated, and intermediate), was significantly stronger in the group with dark seeds (5.2 times in 2019, and 3.7 times in 2020). There were no significant differences in the percentage of individual alkaloids within the total amount either between the years of research or among the groups with different pod types or the groups with different seed coat colors

Complex assessment of narrow-leaved lupine (<i>Lupinus angustifolius</i> L.) accessions from the VIR collection in Belarus

Fifty narrow-leaved lupine accessions of various origin from the VIR collection were studied in Minsk District, Republic of Belarus, and described by a set of morphobiological, biochemical and molecular-genetic characters. According to the results of field and laboratory studies, 10 promising accessions were selected. They are recommended for use in regional breeding programs and included in the working collection of the Belarusian State University

Ultraviolet crosslinking of corneal collagen in patients with thin cornea. Literature review

For the treatment of progressive keratoconus in the early stages, corneal collagen crosslinking is currently actively used. This technique is based on the stabilization of the pathological process by increasing the biomechanical properties of the own cornea. The thickness of the cornea less than 400 microns significantly limits the possibility of a standard cross-linking procedure performing.The article analyzes the literature data on the use of various methods of corneal crosslinking with a corneal thickness of less than 400 microns, which signifi cantly limits the possibilities of the standard procedure.It is known, that during crosslinking, at the initial stage, de-epithelialization of the cornea is performed, which, in the postoperative period, leads to a pronounced corneal syndrome. This determined the direction of the fi rst modifi cations of the technique associated with the use of partial de-epithelialization or its complete absence. Later, during cross-linking of “thin” corneas, techniques with the use of additional covering materials were actively used in order to replenish the missing corneal tissue of the patient during the UV irradiation procedure. Among them are the use of a soft contact lens without an ultraviolet fi lter, the use of a corneal lenticule obtained after SMILE surgery, the use of a protective fl ap of the donor cornea obtained using a femtosecond laser from the residual stroma of the corneal disc after descemet membrane transplantation or posterior lamellar keratoplasty. The variety of the proposed modifications and the ongoing search for better options indicate the demand for this technology and the need for further research, taking into account the individual characteristics of the patient’s ectasia

Impact of weather and climate on seed protein and oil content of soybean in the North Сaucasus

For a targeted search of initial breeding material for the quality of soybean seeds, it is necessary to know the patterns of the dependence of the corresponding seed characters on the weather and climatic conditions in a particular region. Global climatic change, the concretization of which is relevant, has a share in this dependence. Thus, the aim of this work was to identify the relationship between the variability of protein and oil content in soybean seeds with climatic parameters in the North Caucasus as well as trends in this variability over a long time period. The study of 1 442 soybean accessions from VIR collection in the Krasnodar region during 1987–2015 had been carried out and the tendencies of the variability of protein and oil content in seeds in this environment were estimated. The regression analysis in differences with forward stepwise selection of variables has been used to construct models for the dependence of the protein and oil content on generalized agrometeorological indices. During 1987–2015, for the period with temperatures above 10 °C, the sums of active temperatures increased by 218 °C/10 years and precipitation decreased by 20.9 mm/10 years. In the dynamics of protein content, a trend has been revealed as an increase by 2.5 % over 10 years, while there is no reliable trend in oil content. The maximum average mean of oil content and the smallest protein were in the middle-maturing accessions (22.2 and 38.8 %), and a relatively high protein content was detected, on average, in the early- (21.6 and 40.0 %) and late-maturing (20.2 and 39.9 %) varieties. The protein content had been increasing with a growth of the duration of the period with temperatures above 22 °C and decreasing with a raise in precipitation over a period of temperatures above 18 °C. The accumulation of oil in seeds was promoted by an increase of the hydrothermal coefficient over the period with temperatures above 19 °C, and, in late-maturating varieties, prevented by a prolonged autumn period with temperatures below 15 °C. Long-term growth in protein content is due to both climatic change and genetic improvement of varieties

On the results of the 5th Vavilov International Conference (November 21–25, 2022)

Under the auspices of the 5th Vavilov International Conference held in St. Petersburg on 21–25 November 2022, eight events were held on the conservation, development, study and practical use of plant genetic resources (PGR) collections, as well as on the scientific heritage of Nikolay Ivanovich Vavilov and the development of the scientific schools founded by him and the activities of his associates and followers. In view of the modern context of new trends in the development of science, fundamental knowledge, modern methods and technologies, as well as of climatic and economic challenges, the development of the scientific heritage of N.I. Vavilov plays a big role for scientific and technological development. A total of 185 oral presentations was made at the 5th Vavilov International Conference. Meetings of the Conference attracted over 330 participants. This publication reflects the main objectives and content of the performed activities and contains key recommendations emanating from the Conference, including (1) recommendations for the conservation, study and use of PGR, including those on the multidisciplinary basis; (2) recommendations on activities to ensure coordination in the field of conservation, research, breeding and seed production; (3) recommendations on the normative and legislative regulation in the sphere of breeding, seed production, development, maintenance and use of genetic resource collections; (4) recommendations on training, guidance and education. Presentations made at the Conference show that over the past five years there has been a significant increase in the use of modern methodical approaches, i.e. molecular-genetic, genomic and omics in the field of PGR research. All this provides a solid basis for the development of new breeding methods (Next-Generation Breeding). At the same time, it is emphasized that new breeding technologies based on the acquired knowledge, can lead to further progress not in isolation from, but in conjunction with the amassed heritage of classical breeding. Among the discussed and proposed issues, the Conference Resolution identifies those requiring special and urgent attention: (1) the need to legislate for the preservation and expansion of crop diversity in the State Register of Varieties and Hybrids of Agricultural Plants Approved for Use; (2) the inadmissibility of reducing the list of these crops; (3) the inadmissibility of reducing of the number of state variety testing sites; (4) the inadmissibility of reducing of time limits of state variety testing from three to two years or one year; (5) the need to bring the concepts of “genetic passportˮ and “genetic passportizationˮ used in legal and regulatory acts to the canonical understanding of “genetic passportˮ as a document reflecting individual genetic features of an organism (cultivar/hybrid/breed/strain), which make it possible to distinguish its genotype from that of other organisms (cultivars/hybrids/breeds/ strains) of a particular species and the need to carefully elaborate methods of genetic certification of each crop, taking into account all types of genetic markers (molecular-genetic markers (DNA markers), protein and morphological markers). The Conference also noted that under the conditions of the increasing climate change and its sudden unpredictable fluctuations, reliable conservation of valuable plant genetic resources in situ and ex situ is required in order to avoid the irreversible loss of part of plant agrobiodiversity. In addition, extensive expeditionary surveys should be undertaken in the nearest future in crop and CWR diversity centers, under-explored areas, as well as in the regions with extreme environmental conditions and those prone to anthropogenic impacts

Selection of an optimal method for screening the collection of narrow-leaved lupine held by the Vavilov Institute for the qualitative and quantitative composition of seed alkaloids

Narrow-leaved lupine (Lupinus аngustifolius L.) is a widely cultivated leguminous forage and green manure crop with a potential for human nutrition. However, the presence of secondary metabolites – alkaloids – in lupine seeds considerably affects the quality of raw produce, reducing its nutritive value; in addition, high concentrations of alkaloids are toxic to humans and animals. Therefore, plant breeders working with lupine need to gain knowledge about the variability of alkaloid content in seeds of different genotypes and search for the sources of their low concentrations in the crop’s gene pool. The collection of narrow-leaved lupine genetic resources held by the N.I. Vavilov Institute of Plant Genetic Resources (VIR) offers wide opportunities for such search by means of mass screening. For its part, largescale gene pool screening requires the selection of an optimal technique to measure alkaloid content in seeds, so that it would be easily reproducible and as little labor-, time- and fund-consuming as possible. The results of the search for such method are presented. Qualitative and quantitative indices were compared when target compounds had been extracted with multicomponent mixtures and individual reagents (chloroform, methanol, etc.) and the extracts analyzed using gas chromatography-mass spectrometry. High-performance liquid chromatography combined with mass spectrometry was also employed. Five major alkaloids were found to be present in all types of extracts: lupanine, 13-hydroxylupanine (dominant ones), angustifoline, sparteine, and isolupanine. The fullest extraction of alkaloids was observed when the extractant with an added alkaline agent was used (425 mg/100 g). The lowest level of extraction was registered with chloroform (216 mg/100 g). The significance of the differences was confirmed statistically

ИССЛЕДОВАНИЕ РАДИОАКТИВНОГО ЗАГРЯЗНЕНИЯ МОРСКОЙ БИОТЫ В СВЯЗИ С АВАРИЕЙ НА АЭС «ФУКУСИМА-1»

134Cs and 137Cs contents have been studied in 44 samples of the marine biota including four species of brown and red algae (11 samples), four species of invertebrates (8 samples) and ten species of fish (25 samples). The samples have been collected in the Northwest Pacific Ocean and in the Seas of Okhotsk and Japan within the framework of the Russian monitoring program that started in 2011 to study environmental consequences of the accident at “Fukushima-1” NPP. In 2011–2012, total activity of both cesium radioisotopes for all the samples analyzed did not exceed 1 Bq kg–1 (wet weight). This value is negligible compared to the safe level of 130 Bq kg–1 (for 137Cs) for the fish consumption in Russia. 134Cs, a marker of the Fukushima-derived contamination, has been determined at a level of 0.2–0.4 Bq kg–1 (wet weight) for three samples of pacific saury (Cololabis saira) collected from areas near Shikotan Island in Sempember 2011 and 2012. The study shows that the Fukushima accident has no considerable impact on radiation conditions in the Kuril-Kamchatka region of the Northwest Pacific Ocean and in the Russian waters of the Sea of Japan.Изучено содержание радионуклидов 134Cs и 137Cs в 44 пробах морских организмов, представленных четырьмя видами водорослей (11 проб), четырьмя видами беспозвоночных животных (8 проб) и десятью видами рыб (25 проб). Образцы морских организмов были отобраны в водах Японского и Охотского морей и северо-западной части Тихого океана в 2011–2012 гг. в рамках программы комплексных исследований по изучению последствий аварии на АЭС «Фукусима-1» для дальневосточных регионов Российской Федерации. Во всех проанализированных пробах удельная активность радионуклидов цезия (по сумме двух изотопов) не превышала 1 Бк/кг (на сырой вес). Присутствие 134Cs – маркера «фукусимских» выбросов и сбросов – было достоверно обнаружено в трех пробах тихоокеанской сайры (Cololabis saira), выловленной у Южных Курил в 2011 и 2012 гг. Проведенное исследование показывает, что авария на АЭС «Фукусима-1» не оказывает заметного воздействия на радиационную обстановку в Японском море и Курило-Камчатском районе Тихого океана

Migration, proliferation and cell death of regenerating liver macrophages in an experimental model

Relevance . Macrophages are the leading regulatory cell-lineage taking part in reparative processes in mammals, and the liver is no exception. The ratio of monocyte migration, proliferation and death of macrophages during liver regeneration requires further studies. The aim was to quantify the intensity of monocyte migration, cell proliferation and apoptosis of resident liver macrophages after its 70 % resection in a mouse model. Materials and Methods. We performed 70 % liver resection in sexually mature male BalbC mice. Cells of liver monocyte-macrophage system were obtained by magnetic sorting by marker F4/80. The immunophenotype of the isolated cells was further studied by cytofluorimetry, the level of proliferation and cell death, the content of cyclins and P53 was determined by western blot. Results and Discussion . It was found that after partial hepatectomy there is a marked migration of monocytes/macrophages positive for Ly6C and CD11b markers to the liver, the migration process starts already in the first day after the operation. On the same terms there is a rise in proliferative activity of macrophages, established by Ki67 marker, the peak of proliferation - 3 days after partial hepatectomy. A significant increase in the number of dying macrophages was found early after liver resection. Conclusion . The obtained data indicate that liver regeneration in mammals on the model in mice is accompanied by proliferation migration and cell death of macrophages. Taking into account the immunophenotype of macrophages, we can conclude that Ly6C+ blood monocytes migrate to the liver, and resident macrophages participate in proliferation. The obtained data confirm the universality of the course of reparative processes in mammals

Standing stock of Antarctic krill (Euphausia superba Dana, 1850) (Euphausiacea) in the Southwest Atlantic sector of the Southern Ocean, 2018–19

Estimates of the distribution and density of Antarctic krill (Euphausia superba Dana, 1850) were derived from a large-scale survey conducted during the austral summer in the Southwest Atlantic sector of the Southern Ocean and across the Scotia Sea in 2018–19, the ‘2018–19 Area 48 Survey’. Survey vessels were provided by Norway, the Association of Responsible Krill harvesting companies and Aker BioMarine AS, the United Kingdom, Ukraine, Republic of Korea, and China. Survey design followed the transects of the Commission for the Conservation of Antarctic Marine Living Resources synoptic survey, carried out in 2000 and from regular national surveys performed in the South Atlantic sector by the U.S., China, Republic of Korea, Norway, and the U.K. The 2018–19 Area 48 Survey represents only the second large-scale survey performed in the area and this joint effort resulted in the largest ever total transect line (19,500 km) coverage carried out as one single exercise in the Southern Ocean. We delineated and integrated acoustic backscatter arising from krill swarms to produce distribution maps of krill areal biomass density and standing stock (biomass) estimates. Krill standing stock for the Area 48 was estimated to be 62.6 megatonnes (mean density of 30 g m–2 over 2 million km2) with a sampling coefficient variation of 13%. The highest mean krill densities were found in the South Orkney Islands stratum (93.2 g m–2) and the lowest in the South Georgia Island stratum (6.4 g m–2). The krill densities across the strata compared to those found during the previous survey indicate some regional differences in distribution and biomass. It is currently not possible to assign any such differences or lack of differences between the two survey datasets to longer term trends in the environment, krill stocks or fishing pressure