Relative Dormancy Research Articles

Self-Reproduction and Evolution in Cellular Automata: 25 Years After Evoloops.

The year 2024 marks the 25th anniversary of the publication of evoloops, an evolutionary variant of Chris Langton's self-reproducing loops, which proved constructively that Darwinian evolution of self-reproducing organisms by variation and natural selection is possible within deterministic cellular automata. Over the last few decades, this line of Artificial Life research has since undergone several important developments. Although it experienced a relative dormancy of activity for a while, the recent rise of interest in open-ended evolution and the success of continuous cellular automata models have brought researchers' attention back to how to make spatiotemporal patterns self-reproduce and evolve within spatially distributed computational media. This article provides a review of the relevant literature on this topic over the past 25 years and highlights the major accomplishments made so far, the challenges being faced, and promising future research directions.

FEATURES OF DETERMINATION OF MODERN GAS MIGRATION IN THE UPPER LAYERS OF THE LITHOSPHERE

The study of modern gas migration is a topical issue both to determine its impact on mineral deposits and the environmental impact of gases released into the Earth's atmosphere. The redistribution of gases in the lithosphere and their release to the surface correspond to geological processes that last for millions of years. Each geologic structure can have both more active periods and periods of relative dormancy. Discontinuous faults in the lithosphere are the paths of migration of gases (fluids). 
 The modern migration in different geological structures was determined on the basis of gas samples taken from the surface. The author's methodology is based on determining the gas state of the upper layers of the lithosphere and establishing individual compositions of gas mixtures from the selected samples. The development is based on geological, structural and geochemical studies to determine gas migration to the surface. The results can also be used to identify discontinuities and areas with anomalous gas content, which are mainly characteristic of oil and gas and coal deposits. 
 Based on the change in quantitative and qualitative gas indicators compared to the generally accepted data on the gas composition of the atmosphere, areas with the most abnormal gas indicators, in particular methane or its homologues, are identified, which allows us to identify areas with active modern gas migration. It is worth noting that gas indicators may differ at different times of the year. Such peculiarities are usually determined by the intensity of migration to the surface, which is characteristic of each structure, and not only by the change of season. 
 On the basis of studies of gas mixtures (methane, heavy hydrocarbons, hydrogen, nitrogen, carbon dioxide and helium), the polygenetic composition of natural gas in the studied areas opened by mine workings at the surface and at depth is substantiated. This allows us to attribute them to mobile gas-geodynamic systems, in which intensive gas transfer processes are still taking place in the near-surface layers of the lithosphere.

Abstract 1164: Spatiotemporal profiling defines persister and resistance signatures in targeted treatment of melanoma

Abstract Over half of BRAF mutant melanoma patients with response to targeted therapy recur within 15 months. Resistance is postulated to arise from certain clonal populations that enter a slow cycling persister state, evade treatment with relative dormancy, and repopulate the tumor when reactivated. Via longitudinal profiling we define expression states of clonal populations and track their evolutionary progression. BRAF mutant patient derived melanoma xenografts were treated with BRAF/MEK inhibitors through maximum tumor size reduction and re-growth. Spatial transcriptomics (ST) was performed at 5 timepoints across 94 days of treatment, tracking clonal populations with intact tissue structure. Deep learning on H&E-stained images automatically detected histological features that co-localize with expression levels. A novel computational pipeline performed clustering, differential expression and pathway enrichment analysis, copy number variation detection, and pseudotemporal ordering, allowing spatial recreation of clonal phylogenies and cell fate trajectory inference during the treatment course. Three clonal categories were defined; Sensitive: predominant in treatment-naïve samples, Persister: remaining clusters in maximally shrunken specimens, Resistant: re-emergent, fast-proliferating. Analysis of clonal composition identified GAPDH and CCND1 as highly expressed in sensitive clones, suppressed in persisters, and reactivated in resistant clones; TYRP1, DCT, MITF, and NGFR showed an opposite pattern. Persister clones evolved from oxidative phosphorylation toward glycolysis and MAPK regulation. Spatial analysis showed increased glycolysis:oxidative phosphorylation ratio in centrally located sensitive clusters, with more balanced peripheral expression. Resistant clones showed upregulated DUSP6 expression and enrichment in Orexin signaling and MAPK regulation. Imaging- and expression-based clones were highly concordant. Spatial profiling during melanoma treatment identified transient persister and emergent resistant clones, defining expression profiles and phenotypic features. Altered ratio of oxidative to glycolytic metabolic pathways was a hallmark of clonal evolution in both space and time. Specific MAPK pathway re-entry points were identified as candidate resistance mechanisms, suggesting potential therapeutic targets. Deep learning features derived from histological images showed good correlation with ST profiles, providing a promising method for clonal tracking via images alone. This longitudinal experiment mimics a tumor’s clinical course, inducing persistence and resistance via treatment that parallels that seen by patients. Combining ST and imaging techniques, we provide insight into clonal dynamics with novel spatiotemporal resolution, defining an evolutionary roadmap to acquired treatment resistance. Citation Format: Jill Carol Rubinstein, Sergii Domanskyi, Todd B. Sheridan, Brian J. Sanderson, SungHee Park, Jessica Kaster, Haiyin Li, Olga Anczukow, Meenhard Herlyn, Jeffrey H. Chuang. Spatiotemporal profiling defines persister and resistance signatures in targeted treatment of melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1164.

Hepatitis A: Current view of an ancient disease

Hepatitis A: Current view of an ancient disease

Fire and seed maturity drive the viability, dormancy, and germination of two invasive species: Acacia longifolia (Andrews) Willd. and Acacia mearnsii De Wild

Key message: Acacia longifoliaandAcacia mearnsiiexhibit different reproductive behavior (viability, germination, and dormancy) in relation to fire and seed maturation. The potential of invasion ofA. longifoliais stronger than that ofA. mearnsii.A. longifoliagerminates abundantly between fires and after fires, whileA. mearnsiionly germinates after fire and needs higher thermal thresholds to break dormancy. Context: Fire affects environments through the modification of biological processes such as seed viability, dormancy, and germination. Seed maturation stage can modulate seed response to fire. Invasive alien species could be enhanced by forest fires. Aims: To analyze the viability, germination, and dormancy of two invasive alien species (Acacia longifolia and Acacia mearnsii) in relation to fire and seed maturation. Methods: Viability of seeds was obtained performing a tetrazolium test. Additionally, we obtained germination and dormancy in mature and fresh seeds simulating fire conditions through different levels of fire factors (smoke, ash, charcoal, and heat). Results: Control viability of seeds was 100% in the two Acacia species and maturation stages and severe heat reduced it to zero. Germination of A. longifolia varied depending on the maturation stage, being higher in fresh seeds. In A. mearnsii, germination did not change with maturation. In both species, heat stimulated germination by breaking seed dormancy. Seed maturation stage and fire factors affect the germination speed of each species differently. Conclusion: Fire reduces viability, stimulates germination, and breaks dormancy of the two species. Seed maturity exerts notable effects on A. longifolia reproductive behavior.

Influence of psychoemotional stress on microbal landscape of gingival furrow

Relevance of the research topic. The oral cavity is one of the most diverse microbiomes in the human body, which is divided into several biotopes: oral mucosa, dental plaque, gingival fluid and gingival sulcus zone and others. The biotope of the gingival sulcus is unique in that quantitative and qualitative changes in the microbial communities of this microecological system can lead to the development of the main dental diseases — gingivitis, periodontitis and caries. Purpose. To study the influence of emotional stress on the microbal landscape of the gingival furrow, which is in a state of eubiosis and dysbiosis. Materials and methods. The study involved 67 aged by 30–49 years. A microbiological study was made of the general microbial contamination of the gingival furrow and its colonization by individual microbal species using aerobic and anaerobic cultivation methods. Results. In the state of relative dormancy, 100 % of people without gum disease were found to have an eubiotic condition of the gingival microbal, at 100 % of persons with periodontis the microbal of the gingival groove was in a state of dysbiosis. Summary. The influence of the stressor on the disorder of the balance of the microbial homeostasis of the dental gingival slit causes an increase in the imbalance of microbial associations in the form of a decrease in the comensal microflora and an increase in the opportunistic pathogenicity. Highlights. 1. Emotional stress may cause the development of periodontal diseases in people who work in the field of law enforcement. 2. On a background of emotional stress the dysbalance of microbial associations increases.

ИЗУЧЕНИЕ МИКРОБНОГО ПЕЙЗАЖА ДЕСНЕВОЙ БОРОЗДЫ В ЗАВИСИМОСТИ ОТ КЛИНИЧЕСКОГО СОСТОЯНИЯ ТКАНЕЙ ПАРОДОНТА И УРОВНЯ ЭМОЦИОНАЛЬНОГО НАПРЯЖЕНИЯ

Relevance of the research topic. The oral cavity is one of the most diverse microbiomes in the human body, which is divided into several biotopes: oral mucosa, dental plaque, gingival fluid and gingival sulcus zone and others. The biotope of the gingival sulcus is unique in that quantitative and qualitative changes in the microbial communities of this microecological system can lead to the development of the main dental diseases - gingivitis, periodontitis and caries. The scientific literature on the etiology of these diseases determines the microbial landscape of the gingival sulcus as the dominant causative factor. A significant influence on the microflora of periodontal tissues is exerted by various stressors of a modern person. 
 Purpose ― to study the influence of emotional stress on the microbal landscape of the gingival furrow, which is in a state of eubiosis and dysbiosis.
 Materials and methods. The study involved 67 aged by 35―44 years. A microbiological study was made of the general microbial contamination of the gingival furrow and its colonization by individual microbal species using aerobic and anaerobic cultivation methods. 
 Results. In the state of relative dormancy, 100 % of people without gum disease were found to have an eubiotic condition of the gingival microbal, 100 % of persons with periodontis - the microbal of the gingival groove were in a state of dysbiosis.
 Summary. The influence of the stressor on the disorder of the balance of the microbial homeostasis of the dental gingival slit causes an increase in the imbalance of microbial associations in the form of a decrease in the comensal microflora and an increase in the opportunistic pathogenicity.

Characteristics and mechanisms of coupled road and rainfall-induced landslide in Sichuan China

Field reconnaissance, geological mapping and photographic interpretation are utilized to study the failure mechanisms of July 2 catastrophic debris slide in 2017. The results suggested that the landslide was a reactivation of an ancient landslide after periods of relative dormancy, as manifestation of a retrogressive motion, which is triggered by the continuous engineering excavation as leads to rock mass unloading and decrease of mechanical properties of rock–soil mixture. The reactivated zone dominantly spread on the upper part of the ancient landslide area. The frequent tectonic movements rendered the potential landslide zone by fragmenting the structure. The fractured and fissile rock mass became further weakened by incessant rainfall that finally led to the failure of the rock mass.

Seed dormancy in relation to predation and pathogenicity of four tropical Fabaceae species from Sri Lanka

According to the seed defense theory, predation and pathogenicity should be lower in physically dormant (PY) seeds than those of no-dormant (ND). Thus, a study was conducted to determine the predation and pathogenicity of four tropical Fabaceae species to test the above hypothesis. Imbibition and germination of manually scarified (MS) and untreated (UT) seeds were tested using locally collected seeds. Pathogenicity and predatory rates of MS and UT seeds of each species was observed by keeping them separately in a woodland and a grassland for four weeks. Nutrient content and production of volatile compounds in seeds were determined. Germination and imbibition experiments confirmed the physical dormancy of two Senna spp., non-dormancy of Bauhinia variegata and physiological dormancy in Pterocarpus indicus seeds. Predation and pathogenicity were higher in the woodland than in the grassland. Lowest seed predation and pathogenicity were recorded in P. indicus and the highest in B. variegata. Pathogenicity and predation of MS seeds of Senna spp. were higher than that of UT seeds. No correlation was revealed between nutrient content and pathogenicity or predation. MS seeds released more volatile compounds than intact seeds as they were in imbibed state. Pathogenicity and predation depended on seed dormancy classes.

RESULTS OF THE ELECTROMYOGRAPHIC STUDY OF MASSETERS IN PATIENTS WITH HYPERMOBILITY OF HEADS OF THE MANDIBLE BY STANDARD TREATMENT AND USING TRANSCRANIAL ELECTRICAL STIMULATION

Aim. This research was designed to study the functional state of masseters in patients with hypermobility of heads of the mandible by the traditional treatment and using transcranial electrostimulation.Materials and methods. There was conducted the examination and treatment of 80 patients with hypermobility of heads of the mandible. All patients were divided into two groups: the 1st group (n=20) received standard treatment, the second group (n=60) received traditional treatment with the inclusion of myogymnastics, massage in the temporomandibular joint area, transcranial electrostimulation, use of the apparatus of A. Sidorenko that limits the movement of the lower jaw. The control group included 10 volunteers without the pathology in the temporomandibular joint. The masseters were studied by an electromyography method before the treatment, in 1 month and in 6 months after the treatment using the computer and Miokom electromyograph. The obtained results were processed with use of the "Statistica Statsoft" program version 6.1 and "Microsoft Excel 2010".Results. The analysis of the amplitude of bioelectric potentials of the masseters made it possible to establish that when using transcranial electrostimulation and the proposed intraoral apparatus of Sidorenko AN, limiting the amplitude of mouth opening, in 6 months after the end of the treatment in patients with hypermobility of the lower jaw the increased bioelectrical activity of the masseters in the state of relative physiological dormancy disappeared, the amplitude of their contractions (93.2%) normalized.Conclusion. The results of the electromyographic study of temporal and masseter muscles made it possible to conclude that use of the transcranial electrostimulation and the intraoral apparatus of Sidorenko AN, limiting the movement of the lower jaw, has a positive effect on the functional state of the muscular apparatus in patients with hypermobility of the mandible heads. In the state of relative physiological dormancy the bioelectric potentials of the temporal and masseter muscles decrease, the amplitude of the bioelectric potentials while chewing and maximum compression of the jaws increases.

American Writers and the Approach of World War II, 1935–1941: A Literary HistoryShell Shock, Memory, and the Novel in the Wake of World War I

American Writers and the Approach of World War II, 1935–1941: A Literary HistoryShell Shock, Memory, and the Novel in the Wake of World War I

Histone 2B-GFP Label-Retaining Prostate Luminal Cells Possess Progenitor Cell Properties and Are Intrinsically Resistant to Castration.

SummaryThe existence of slow-cycling luminal cells in the prostate has been suggested, but their identity and functional properties remain unknown. Using a bigenic mouse model to earmark, isolate, and characterize the quiescent stem-like cells, we identify a label-retaining cell (LRC) population in the luminal cell layer as luminal progenitors. Molecular and biological characterizations show that these luminal LRCs are significantly enriched in the mouse proximal prostate, exhibit relative dormancy, display bipotency in both in vitro and in vivo assays, and express a stem/progenitor gene signature with resemblance to aggressive prostate cancer. Importantly, these LRCs, compared with bulk luminal cells, maintain a lower level of androgen receptor (AR) expression and are less androgen dependent and also castration resistant in vivo. Finally, analysis of phenotypic markers reveals heterogeneity within the luminal progenitor cell pool. Our study establishes luminal LRCs as progenitors that may serve as a cellular origin for castration-resistant prostate cancer.

Sleep onset insomnia, daytime sleepiness and sleep duration in relationship to Toxoplasma gondii IgG seropositivity and serointensity.

Toxoplasma gondii (T. gondii) infects central nervous tissue and is kept in relative dormancy by a healthy immune system. Sleep disturbances have been found to precipitate mental illness, suicidal behavior and car accidents, which have been previously linked to T. gondii as well. We speculated that if sleep disruption, particularly insomnia, would mediate, at least partly, the link between T. gondii infection and related behavioral dysregulation, then we would be able to identify significant associations between sleep disruption and T. gondii. The mechanisms for such an association may involve dopamine (DA) production by T. gondii, or collateral effects of immune activation necessary to keep T. gondii in check. Sleep questionnaires from 2031 Old Order Amish were analyzed in relationship to T. gondii-IgG antibodies measured by enzyme-linked immunosorbent assay (ELISA). Toxoplasma gondii seropositivity and serointensity were not associated with any of the sleep latency variables or Epworth Sleepiness Scale (ESS). A secondary analysis identified, after adjustment for age group, a statistical trend toward shorter sleep duration in seropositive men (p = 0.07). In conclusion, it is unlikely that sleep disruption mediates links between T. gondii and mental illness or behavioral dysregulation. Trending gender differences in associations between T. gondii and shorter sleep need further investigation.

Streamflow as an ecological factor influencing radial growth of European ash (Fraxinus excelsior (L.))

The aim of our study was to find the hydrological, precipitation and temperature signal in tree rings and selected cell parameters of European ash (Fraxinus excelsior L.) in the floodplain forest of the Warta River. A total of 30 samples were taken at breast height, using a Pressler borer, from 15 trees (2 samples per tree) during the 2012 vegetation season. We measured the tree-ring widths, built the chronology, selected the tree that was the best correlated with the rest, and used both samples from this tree for cell analysis. For earlywood vessels, average and total density, as well as the percentage of water conductive area were calculated for the years 1950–2011. We found that high water levels during September to January of the previous year positively influence tree growth. This finding could be associated with the accumulation of nutrients, like nitrogen, in the floodplain soil, which are then used at the beginning of the growing season or earlier, when the trees transition from the true dormancy phase to relative dormancy. Temperature at the end of winter and early spring did not play a big role in tree-ring width, whereas low temperature in February negatively affected the number and the area of the earlywood cells. In addition, precipitation during the growing season, especially in June, had a positive effect on ring width. To summarize, our research showed that in the case of European ash from lowland flood-areas, river flows had a large influence on growth. Precipitation and air temperature, which both shape the river regime and directly supply forest ecosystems with water, were also important for tree growth and tree-ring structure.

Variability of physical dormancy in relation to seed mechanical properties of three legume species

Many Fabaceae species have a hard and impermeable seed coat that requires scarification for germination. The variability within a batch and between batches of the same species can be very high, resulting in inefficient dormancy breaking. The main objectives of this study were to investigate the variability in hardseededness among four populations of the legume species Medicago polymorpha, Trifolium glomeratum and T. subterraneum, and to evaluate the effect of the best scarification treatments on the mechanical properties of the seed coat. These species have very small seeds that hinder scarification procedures. Different treatments, including sanding and temperature changes, were studied. Results varied among species, and the most efficient treatment for breaking dormancy was determined for each one. For each species, wide variability was observed in the best scarification treatment within and among populations. The effect of the best scarification treatment on the seed coat of each species was examined by means of scanning electronic microscopy (SEM). Evident differences were found in T. glomeratum, as the treatment used was sanding. In T. subterraneum, scarified seeds (by thermal treatment) showed wider hilum opening. No differences were observed in M. polymorpha seeds.

Onset of drying and dormancy in relation to water dynamics of semi-arid grasslands from MODIS NDWI

Our knowledge of autumn phenology and its response to climate variability is currently limited. One way to improve our understanding of autumn phenology at the landscape scale is to investigate autumn vegetation dynamics based on multiple vegetation indices from remote sensing data. In this study, we derived two autumn phenological metrics (phenometrics), onset of drying and dormancy, for semi-arid grasslands from MODIS normalized difference water index (NDWI) time series. The onset of drying represents the start of decline in the vegetation’s metabolism during autumn, and the onset of NDWI-based dormancy signifies the end of metabolic activity. These NDWI-based phenometrics were then compared with enhanced vegetation index (EVI)-based phenometrics in northeastern China from 2001 to 2013. Influences of climatic variability on autumn phenology were analyzed using partial correlation analysis. We found that, in general, the onset of drying was slightly later than the onset of EVI-based senescence. Both did not strongly correlate with precipitation and mean minimum temperature in August. The onset of NDWI-based dormancy had, on average, a time lag of seven days, relative to the onset of EVI-based dormancy during 2001–2013. Moreover, it showed a much stronger response to mean minimum temperature in September than EVI-based dormancy. A colder autumn generally advanced the onset of NDWI-based dormancy, while it had little effect on the onset of EVI-based dormancy in the study area. These results suggest that phenological studies using NDWI could expand our understanding of land surface phenology. Furthermore, considering the different responses of the onset of NDWI- and EVI-based dormancy to climate variability, a combination of these phenometrics could contribute to the study of the ecosystem processes (e.g., carbon cycle) in semi-arid grasslands.

Lake Victoria Goldfields

After a period of relative dormancy, the Lake Victoria Goldfields (LVG) in Tanzania, Kenya and Uganda have emerged as an important site for gold mining and exploration in Africa. The Neoarchaean greenstone belts of the LVG are composed mainly of metavolcanic sequences overlain by younger Kavirondian clastic metasedimentary strata. Intermediate to felsic plutonic rocks include local, older syn-volcanic bodies and an extensive suite of late, circa 2650-2640 Ma potassic (K)-granitoids, which substantially invade and disrupt the greenstone belts. Gold deposits are widely distributed but particularly concentrated in three belts: Sukumaland, Musoma-Mara and Busia-Kakamega. Many deposits are simply composed of quartz veins in shear zones and fractures in the Nyanzian host rocks (e.g. Bulyanhulu, Buck Reef and Rosterman). Buzwagi and Nyabirama are composed of quartz vein arrays within intrusions. Several are hosted by folded banded iron-formation (Geita, Golden Ridge, Tulawaka, and Nyanzaga). Nyanzaga, however, is a discordant pipe shaped stockwork containing dolomite, silica and sulphides as open-space fill in high level veins. Gokona- Nyabigena at North Mara is closely associated with porphyritic volcanic and sub-volcanic intrusive rocks and is noted for stockwork-disseminated mineralisation and extreme K-feldspar alteration. Field evidence points to a relatively late, syn-orogenic timing for the majority of the deposits irrespective of style. Most deposits were discovered and exploited in colonial times but many have been expanded considerably by modern exploration. Improved geological knowledge has resulted from this private sector exploration using high-resolution aeromagnetic, electromagnetic and radiometric surveys, followed up by regolith and outcrop mapping and systematic drill testing of large areas (rotary air blast (RAB), reverse circulation (RC), aircore and diamond drill core). Lithogeochemistry and geochronological studies have been carried out by several companies in support of their regional exploration programmes. The LVG is now considered mature from an exploration point of view, so future developments will require the investigation of vein deposits to greater depth and/or the discovery of additional examples of the lower grade stockwork-disseminated styles which may have been overlooked during the early rounds of exploration.

The influence of the method of silver fir growing and nutrition on sprouting and chlorophyll fluorescence during spring

To compare breaking of dormancy in relation with climatic conditions and reaction to late frost fir plants growing in sun, in shade and at magnesium deficiency were evaluated. Sprouting and chlorophyll a fluorescence of needles were evaluated from March to May 2011. As a consequence of May frost 100% of plants from sunny treatments and 70% of firs shaded with shade cloth were affected by necrosis of sprouting shoots; fir-trees shaded by the stand remained fully intact. No relationship between the index of shoot sprouting and damage was confirmed. Firs with Mg deficiency had the lowest maximum quantum yield of PSII photochemistry of the dark-adapted tissue (F V /F M ) and performance index on absorption basis (PI abs ) in the long term. Regression models of F V /F M and PI abs and selected environmental parameters showed that chlorophyll fluorescence was influenced to the largest extent by minimum temperature of the day of measurement and also by acclimation to the light environment. The process of breaking of dormancy increased fir vulnerability to thermal stresses of the environment - late frosts.

Seed dormancy and germination characteristics in relation to the regeneration of Acer pycnanthum, a vulnerable tree species in Japan

Seed dormancy and germination characteristics of the vulnerable tree species Acer pycnanthum were investigated to understand its regeneration strategy. Seeds of A. pycnanthum mature 1 month after pollination and are dispersed in late spring. All dispersed seeds were in dormancy upon collection from which they were released by cold (5 °C) stratification over a period of at least 12 weeks. Germination percentages were higher under low temperature conditions (10–20 °C) and when the temperature was alternated in diurnal cycles. Light effects on germination were not observed. Seed viability was not lost even though seeds had experienced room temperature conditions (20–30 °C, 35–70 % humidity) after dispersal for 5–10 months. Seeds of A. pycnanthum can endure summer heat and survive until the following spring, allowing their seedlings to germinate promptly. In the case of light intensity-independent dormancy release, regeneration can occur under canopy conditions where shade-intolerant seedlings are at a disadvantage. To verify this conclusion, the shade tolerance of A. pycnanthum requires further investigation.

CLINICAL STATUS AND CHEMILUMINESCENT ACTIVITY OF NEUTROPHILS IN PATIENTS WITH ADVANCED PURULENT PERITONITIS IN THE DYNAMICS OF POSTOPERATIVE PERIOD

The aim of this study was to evaluate the clinical condition and to study the chemiluminescent activity of granulocytes of patients with widespread purulent peritonitis in the dynamics of post-operative treatment. The severity of the patients was determined by the SAPS scale, the presence of systemic inflammatory response syndrome was assessed by the criteria of the ACCP/SCCM. Severity and prognosis of the disease was evaluated using the Mannheim peritonitis index and the index of abdominal cavity. The severity of multiple organ failure at admission to the hospital and in postoperative period dynamics were determined by the scale of the SOFA. The study of lucigenin- and luminal-dependent chemiluminescence of neutrophils in peritonitis were taken on admission to the hospital, and on the 7th, 14th and 24th day of the postoperative period. There were a variety of systemic complications (tertiary peritonitis, perforation of hollow organs, abscesses of the abdominal cavity and other) in patients with widespread purulent peritonitis 2nd severity in 96,2% of cases. The mortality rate among patients amounted to 22.2%. It was found in the study of neutrophils chemiluminescent activity that intensity of the “respiratory burst” in pre- and postoperative periods in patients with peritonitis is defined mainly by the synthesis level of secondary reactive oxygen species. The level of synthesis of superoxide radicals by neutrophils in a state of relative dormancy, increased by 14 days after the operation and is reduced to the reference level to the 21st day. In the preoperative period and before the end of the observation level of synthesis of secondary reactive oxygen species by neutrophils of patients with peritonitis was increased, but is on the background of the slow activation of enzymes, providing a “respiratory burst”. Trend towards normalization of neutrophils chemiluminescent activity in the blood of patients with peritonitis by the end of the observation period (24th day of the postoperative period).