[Preoperative diagnosis of intestinal ischemia in small bowel obstruction. Only computed tomography? A multiple-center observational study]. / Dooperatsionnaya diagnostika intestinal'noi ishemii pri tonkokishechnoi neprokhodimosti. Tol'ko komp'yuternaya tomografiya?! Rezul'taty mnogotsentrovogo observatsionnogo issledovaniya.

OBJECTIVE: To evaluate the accuracy of clinical, laboratory and instrumental methods for diagnosis of intestinal ischemia following small bowel obstruction in emergency hospitals. MATERIAL AND METHODS: Multiple-center observational retrospective study enrolled 158 consecutive patients with benign small bowel obstruction (SBO) treated at four hospitals between May 2017 and December 2019. The role of clinical, laboratory and instrumental diagnostic methods for intestinal ischemia was analyzed. We assessed the impact of CT and contrast-enhanced X-ray examination on survival of patients. RESULTS: Laboratory parameters as criteria of ischemia following SBO were similar (leukocytosis >14·109/l (p=1.0), serum lactate >2.0 mmol/l (p=0.28), heart rate >90/min (p=0.71) and fever (p=0.74)). The only laboratory indicator with significant differences was serum sodium. Decrease in leukocytosis over time was less common in patients with ischemia (25% vs. 61.3%, p=0.012). Univariate Kaplan-Meier analysis did not establish the effect of CT on survival (7.8% [95% CI 7.6-8.0] vs. 6.5% [95% CI 6.3-6.6], p=0.786). Logistic regression revealed 6.4-fold higher chance of accurate diagnosis (ischemia/non-ischemia) in case of CT-based conclusion of ischemia (95% CI 0.025-0.85). Univariate analysis showed that the use of water-soluble contrast for adhesive SBO was associated with lower mortality (4.1% [95% CI 4.0-4.2] vs. 14.3% [95% CI 13.7-14.9], p=0.032) without assessing the comparability of groups. CONCLUSION: Routine laboratory tests were not specific for intestinal ischemia. Therefore, they should not be considered as the only criteria for surgical tactics in intestinal obstruction. Only CT showed acceptable diagnostic accuracy, and, apparently, only this method has real prospects for improving the quality of diagnosis due to technical support, training of surgeons and specialists for diagnosis.

Brighter is better: bill fluorescence increases social attraction in a colonial seabird and reveals a potential link with foraging.

Crested auklets (Aethia cristatella) are colonial seabirds with brilliant orange bills during the breeding season. We characterized the bill pigment with spectroscopy methods (resonance Raman, fluorescence, absorbance). We excluded carotenoids as a possible chromophore and showed that the pigment most closely resembles pterins. Like pterins the bill pigment fluoresces, and it occurred in two phenotypes that may differ geographically, perhaps due to environmental heterogeneity. The pigment is unique in the Genus Aethia, and its spectra did not match any known molecule. The UV-Vis absorbance spectrum of the bill pigment overlaps with the extracted pigment of euphausiids, a favored food of crested auklets. A color preference associated with prey may have favored characteristics of the crested auklet's accessory bill plates. Crest size, a signal of dominance, tended to correlate positively with highest fluorescence in the single-band phenotype. Brighter bills may function in self-advertisement and verify the status signal of the crest ornament. We tested for a behavioral preference using identical decoys that differed only in bill fluorescence. Crested auklets approached models with fluorescent bills at a higher frequency. In cases where sex of crested auklets was known, males responded at a higher frequency to fluorescent bills, but females did not. In an evolutionary context, bill fluorescence could have conferred an advantage in social interactions, e.g., in dimly lit rock crevices. Bill brightness and color may communicate success in foraging and may function as an honest signal of mate quality.

[Biomarkers of system inflammation in local and diffuse peritonitis]. / Markery sistemnogo vospaleniia pri mestnom i rasprostranennom peritonite.

In cases of any acute surgical abdominal disease the progression of purulent inflammation can lead to local or diffuse peritonitis. The indicators of the degree and specificity of the inflammatory response in blood such as cytokine concentration, neutrophil activity, plasma antioxidant capacity (thiols concentration) could be considered as potential predictors of complications. The luminol-dependent chemiluminescence (CL) response of blood activated by the phorbol ester (PMA), and the concentration of cytokines IL-6, IL-8, IL-10, myeloperoxidase (MPO) and thiols in plasma were measured in patients with uncomplicated condition (group 1, n=8), local peritonitis (group 2, n=9) or diffuse peritonitis (group 3, n=9) at admission to surgery (before surgical operation, b/o), immediately after surgical operation (a/o) and a day after surgery (1 day) as well as in healthy volunteers (norm, n=12). In all time-points the cytokines and MPO concentrations measured by ELISA, in group 3 were higher than in healthy volunteers and in patients in groups 1 and 2. Blood CL demonstrated a more than 5-fold increase above the normal values in all patients, and was also higher in group 2 as compared to group 1 (b/o and a/o). Patients in group 3 had shown both maximum and minimum of CL values, which could be a consequence of neutrophil priming or exhaustion ("immune paralysis"), respectively. The same patients' plasma exhibited low thiol concentration (≤30% vs normal values). In patients with fatal outcomes (group 3, n=2) within a day after surgery, either a decrease of the CL to zero values concurrently with elevated IL-8 and IL-6 concentrations and low thiol levels was observed, or CL exceeded normal values more than 20 times with concurrent complete exhaustion of the plasma thiol pool. No clear dependency between the plasma parameters and neutrophil activity was found. Hence a parameter set for prognosis and/or early diagnosis of infectious complications in acute abdominal pathology should include different biomarkers of the inflammatory response: cytokine profile (IL-6, IL-8, IL-10), MPO and neutrophil activity, antioxidant plasma capacity (e.g., total thiols concentration).

[Appendectomy technique: paradigm shift or a well-forgotten old one? The role of mesoappendectomy in prevention of infectious intra-abdominal complications (announcement of RCT)]. / Metodika appendektomii: smena paradigm ili khorosho zabytoe staroe? Rol' mezoappendiksektomii v profilaktike infektsionnykh intraabdominal'nykh oslozhnenii (anons RKI).

OBJECTIVE: To analyze the role of mesoappendixectomy in the development of intra-abdominal surgical site infection (IAB SSI) after LAE. MATERIAL AND METHODS: A prospective randomized non-blind multiple-center registered (ClinicalTrials.gov NCT03754777) study has been performed for the period from 2016 to 2018. The study was devoted to effectiveness and safety of the modified enhanced recovery protocol in LAE. In the main group, this protocol (n=56) included routine mesoappendixectomy, restrictive strategy for abdominal drainage and postoperative antibiotic prevention. In the control group (n=71), mesoappendixectomy was performed only in case of necrotic changes. Both groups were comparable by demographic parameters and severity of comorbidities. RESULTS: In the main group, significant decrease in the incidence of IAB SSI was found (0% versus 9.8%). Moreover, the main group was characterized by reduced length of hospital-stay (1.43±1.34 d versus 2.94±2, 43 days). CONCLUSION: Mesoappendixectomy should be evaluated in further research as a potential factor in prevention of IAB SSI.

[Laparoscopic surgery for advanced appendicular peritonitis]. / Laparoskopicheskaya khirurgiya rasprostranennogo appendikulyarnogo peritonita.

OBJECTIVE: To evaluate the results of laparoscopic treatment of patients with advanced appendicular peritonitis. MATERIAL AND METHODS: There were 271 patients with acute appendicitis complicated by peritonitis. The main group consisted of patients who underwent laparoscopic appendectomy after diagnostic laparoscopy (n=231), the control group - diagnostic laparoscopy followed by conversion to median laparotomy (n=36). Four extremely ill patients were operated through laparotomy and excluded from the further analysis. RESULTS: Diagnostic laparoscopy was performed in 267 patients with advanced appendicular peritonitis. Laparoscopic appendectomy, debridement and abdominal drainage were performed in 231 (85.2%) patients. Mean age of patients was 44±18.5 years, duration of disease - 36.2±20.3 hours. Diffuse peritonitis was diagnosed in 219 (82%) patients, advanced peritonitis - in 48 (16.5%) cases. Incidence of conversion was 13.5%. Mortality was absent in both groups. Postoperative morbidity was significantly higher in the conversion group (72.2% vs. 29.4%, p<0.0001). CONCLUSION: Laparoscopic interventions for common appendicular peritonitis are feasible, effective and reduce postoperative morbidity.

[Spontaneous diffuse chylous peritonitis during pregnancy]. / Spontannyi khileznyi peritonit vo vremia beremennosti.

Spontaneous chylous peritonitis during pregnancy is a rare disease. Only a few publications are currently devoted to this problem. The authors reported successful treatment of a patient with spontaneous chylous peritonitis in the first trimester of pregnancy. Moreover, etiology, epidemiology, pathophysiology, diagnosis and treatment of patients with spontaneous chylous peritonitis and chiloperitoneum are analyzed. The authors consider laparoscopy as a safe and efficient method of treatment of patients with spontaneous chylous peritonitis including pregnant women.

[Fast-track rehabilitation for acute cholecystitis: intermediate outcomes of prospective randomized trial]. / Uskorennoe vyzdorovlenie pri ostrom kholetsistite: promezhutochnye rezul'taty prospektivnogo randomizirovannogo issledovaniia.

AIM: To analyze an efficacy of FT-protocol in patients with acute cholecystitis. MATERIAL AND METHODS: Prospective randomized study included 102 patients (45 of main group (FT) and 57 of control groups). Patients did not differ by TG13 severity index. The protocol included information, antibiotic prophylaxis, restriction of drainage, intraperitoneal anesthesia with long-term anesthetics, low pressure pneumoperitoneum, antiemetics in the presence of risk factors, early activation and feeding of the patient. Pain was assessed by VAS immediately after surgery, and 2, 6 and 12-24 hours postoperatively. RESULTS: Surgery time was similar in both groups. Need for anesthesia and pain severity were significantly lower in the FT group. A total absence of pain (VAS 0-1) on the 1st postoperative day was noted in 8 (17.7%) of the FT group and 2 (3.5%) patients of the control group (p=0.038). Shoulder pain developed in 4 (8.9%) cases of the main and 22 (38.6%) cases of the control group (p=0.001). Postoperative nausea developed in 13% of the FT group vs 40.5% in the control group (p=0.05). Hospital-stay was 1.29±0.7 days and 2.7±1.6 (p<0.0001), respectively. The time of the first stool was similar. Twenty-four (53.5%) patients of the FT group and 8,9% of the control group were discharged on 1st postoperative day. There were 2 (IIIA) complications in the main group and 3 - in the control group (IIIA, IIIB and IV). There were no mortality and readmissions. CONCLUSION: FT protocol in AC reduce postoperative pain, dyspepsia, shoulder pain and in-hospital stay with equal number of postoperative complications.

[Comparison of standard and fast track rehabilitation in patients with acute appendicitis. Intermediate results of multicenter prospective randomized trial]. / Sravnitel'naia otsenka metodov standartnoi i uskorennoi reabilitatsii bol'nykh s ostrym appenditsitom. Promezhutochnye rezul'taty mnogotsentrovogo prospektivnogo randomizirovannogo issledovaniia.

AIM: To analyze outcomes of fast track rehabilitation in patients with acute appendicitis. MATERIAL AND METHODS: Prospective, randomized multi-center trial including 86 patients was conducted. There were 38 patients in the main group and 48 in the control group. All patients underwent laparoscopic appendectomy under endotracheal anesthesia. Protocol included informing, no premedication, glucose infusion prior to surgery, antibiotics administration, mesoappendix excision, limited deployment of drainage tubes, intraabdominal prolonged anesthesia, minimal pneumoperitoneum, limited irrigation, minimum power monopolar electrocautery, antiemetics, early activation and eating (2 and 6 hours after surgery). Pain was evaluated by visual-analogue scale. Auscultative peristalsis was considered every 2 hours after surgery. Cortisol level was assessed preoperatively, in 6 and 12-24 hours after surgery in 11 (29%) and 15 (31%) patients of the main and control groups respectively. Discharge criteria: no leukocytosis, fever and pain syndrome requiring anesthesia, no signs of complications and patient's consent. RESULTS: Terms of disease, gender, age and comorbidities were similar in all patients. Duration of surgery under minimal pneumoperitoneum and standard pressure was also similar: 69.2±3.98 and 70.9±3.89 min (p=0.762). Pain syndrome grade and need for analgesics were significantly lower in the main group within entire follow-up. Pain syndrome was absent at the 1st postoperative day in 16 (42%) and 2 (4.1%) patients of both groups, respectively (score 0-1). Phrenic nerve syndrome was observed in 36.8% of the main group and 60.4% of the control group (p=0.05). Incidence of dyspepsia and terms of peristalsis onset were similar. Length of hospital-stay was 1.45 days in the main group and 3.15 days in the control group (p=0.002). In the main group 18 (47%) patients were discharged on the first day after surgery. There were only 4 (8.3%) patients with similar hospital-stay in the control group (p<0.001). There were no repeated hospitalizations. Postoperative cortisol concentration was similar in both groups as well as in complicated and uneventful postoperative period. In the main group postoperative intestinal paresis (Clavien-Dindo grade 2) occurred in 1 patient. In the control group 7 patients had postoperative infiltrate and 1 patient - intestinal paresis (Clavien-Dindo grade 2). Postoperative drainage tube was deployed in 3 out of 7 patients with postoperative infiltrates and 6 of them received antibiotic therapy. Medication was successfully applied in all patients with complications. CONCLUSION: There are some advantages of FTR for AA including reduced pain syndrome, morbidity and less length of hospital-stay. Issue of cortisol concentration requires further trials.

[Transmembrane transport of K+ and Cl- during pollen grain activation in vivo and in vitro].

We studied the possibility of K+ and Cl- efflux from tobacco pollen grains during their activation in vitro or on the stigma of a pistil. For this purpose the X-ray microanalysis and spectrofluorometry were applied. We found that the relative content of potassium and chlorine in the microvolume of pollen grain decreases during its hydration and activation on stigma. Efflux of these ions was found both in vivo and in vitro. In model in vitro experiments anion channel inhibitor NPPB ((5-nitro-2-(3-phenylpropylamino) benzoic acid) in the concentration that was blocking pollen germination, reduced Cl- efflux; potassium channel inhibitor (tetraethylammonium chloride) partially reduced K+ efflux and lowered the percent of activated cells. Another blocker of potassium channels Ba2+ caused severe decrease in cell volume and blocked the activation. In general, the obtained data demonstrates that the initiation of pollen germination both in vivo and in vitro involves the activation of K+ and Cl- release. An important role in these processes is played by NPPB-, TEA- and Ba(2+)-sensitive plasmalemma ion channels.

[Sporopollenin accumulation in Nicotiana tabacum L. microspore wall during its development].

Accumulation of sporopollenin components in microspore wall, its polymerization dynamics and possible participation of reactive oxygen species (ROS) in this process has been studied. For this purpose fluorescent and electron microscopy (TEM) was used. It has been determined that phenylpropanoid components of sporopollenin that form the exine accumulate in the microspore cell wall at the middle and late tetrad stages. At the late tetrad stage, they fully cover the microspore surface and accumulate abundantly in aperture areas. In accordance with this, numerous thick sporopollenin lamellae, electron-dense and acetolysis-resistant, emerge in aperture areas. Exine in the areas between apertures includes both acetolysis-resistant sporopollenin and washout components. These particular parts of the wall are intensively stained with fluorescent dye MitoSOX, which detects the presence of ROS. The staining disappeared after the treatment of microspore with superoxide dismutase, demonstrating the presence of superoxide in the exine. Superoxide easily converts to hydrogen peroxide, which can cause oxidative polymerization of sporopollenin components, leading to the formation of chemically stable biopolymer. The data obtained favor the hypothesis of ROS involvement in the formation of sporopollenin.

[Antioxidant properties of the pollen exine polymer matrix].

The antioxidant properties of exine polymer matrix which forms the outer layer of pollen grain wall were studied. The main component of this matrix is sporopollenin - a unique biopolymer resistant to mechanical and chemical damage. The samples of isolated exine, purified from soluble compounds, were studied with EPR using stable nitroxyl radical TEMPO and DMPO spin trap. At the same time, we analyzed changes in fluorescence of DCFH which detected ROS in the solution. It has been established that exine effectively reduces TEMPO radical and eliminates hydroxyl radical. Also, the fluorometric analysis demonstrated that the exine eliminated H2O2, and this ability significantly decreased after treatment of exine with feruloyl esterase or mild alkaline hydrolysis (1M NaOH), i.e. after hydrolysis of hydroxycinnamic acid esters. After harsh hydrolysis (4M NaOH, 170 degrees C) of ethers bonds a large amount of hydroxycinnamic acids has been released, and exines have lost their antioxidant capacity almost completely. The obtained results point to the ability of extracellular polymer matrix of the exine to eliminate free radicals and H2O2 during crucial periods of male gametophyte development. The participation of ferulic acid and, possibly, of other hydroxycinnamic acids of sporopollenin in these processes has been demonstrated.

[Another discussion of membrane voltage alterations in growing pollen tube].

Here we give a critical analysis of the opinion of Andreev (2011) on membrane potential distribution along the pollen tube plasmalemma. He assumes that a lateral gradient of dipole potential exists, but suggests a lateral gradient of transmembrane potential impossible. We demonstrate by concrete examples that the argumentation of the initiator of discussion is based on inaccurate citation of our experimental data (Breygina et al., 2009) and incomplete analysis of previously published articles. Speaking about transmembrane potential, he doesn't consider numerous facts demonstrating the uneven distribution of transmembrane ion fluxes and ion-transport proteins in the pollen tube plasmalemma, as well as data obtained by modeling of transmembrane potential distribution in objects of different shape. In addition, the assumption on the uneven distribution of dipole potential doesn't have an experimental basis neither in studies of the pollen tube, nor in the practice of using fluorescent voltage-sensitive dyes DiBAC4(3) and Di-4-ANEPPS. We are expecting the author to obtain experimental data in support of his position.

Skin carotenoid status measured by resonance Raman spectroscopy as a biomarker of fruit and vegetable intake in preschool children.

BACKGROUND/OBJECTIVE: Dietary assessment in children is difficult, suggesting a need to develop more objective biomarkers of intake. Resonance Raman spectroscopy (RRS) is a non-invasive, validated method of measuring carotenoid status in skin as a biomarker of fruit/vegetable intake. The purpose of this study was to examine the feasibility of using RRS in preschool children, to describe inter-individual variability in skin carotenoid status and to identify factors associated with the biomarker in this population. SUBJECTS/METHODS: We conducted a cross-sectional study of 381 economically disadvantaged preschoolers in urban centers in Connecticut (USA). In all, 85.5% were black non-Hispanic or Hispanic/Latino, and 14.1% were obese and 16.9% were overweight by age- and sex-specific body mass index (BMI) percentiles. Children had their skin carotenoid status assessed by RRS in the palm of the hand. Fruit/vegetable consumption was assessed by a brief parent/guardian-completed food frequency screener and a liking survey. RESULTS: We observed inter-individual variation in RRS values that was nearly normally distributed. In multiple regression analysis, higher carotenoid status, measured by RRS, was positively associated with fruit/vegetable consumption (P=0.02) and fruit/vegetable preference (P<0.01). Lower carotenoid status was observed among younger children, those participating in the US Supplemental Nutrition Assistance Program, and those with greater adiposity (P<0.05 for all). CONCLUSIONS: We observed wide variability in skin carotenoid status in a population of young children, as assessed by RRS. Parent-reported fruit/vegetable intake and several demographic factors were significantly associated with RRS-measured skin carotenoid status. We recommend further development of this biomarker in children, including evaluating response to controlled interventions.

[Ion-exchange properties of cell walls of red seaweed Phyllophora crispa].

Research into ion-exchange properties of cell walls isolated from thallus of red seaweed Phyllophora crispa was carried out. Ion-exchange capacity and the swelling coefficient of the red alga cell walls were estimated at various pH values (from 2 to 12) and at constant ionic strength of a solution (10 mM). It was established that behavior of cell walls as ion-exchangers is caused by the presence in their matrix of two types of cation-exchange groups and amino groups. The amount of the functional group of each type was estimated, and the corresponding values of pK(a) were calculated. It can be assumed that ionogenic groups with pK(a) -5 are carboxyl groups of uronic acids, and ionogenic groups with pK(a) -7.5 are carboxyl groups of the proteins. Intervals of pH in which cation-exchange groups are ionized and can take part in exchange reactions with cations in the environment are defined. It was found that protein was a major component of cell wall polymeric matrix because its content was 36%.

[Effects of anion channel blockers NPPB and DIDS on tobacco pollen tube growth and its mitochondria state].

Influence of anion channel blockers NPPB and DIDS on pollen tube growth and its mitochondria functioning was studied by means of fluorescence microscopy and flow cytometry. NPPB (40 microM) blocked pollen tube growth completely, but did not change its diameter. DIDS (20-80 microM) caused pollen tube swelling and bursting, suggesting that DIDS-sensitive channels take part in the regulation of pollen tube osmotic balance. The osmotic effect of low DIDS concentration (20 (Mkappa)M) was not accompanied by changes in the tube growth rate. The mapping of membrane potential on the pollen tube plasmalemma using Di-4-ANEPPS revealed the involvement of NPPB-sensitive but not DIDS-sensitive anion channels in the maintenance of the longitudinal membrane potential gradient along the tube surface. The study of isolated pollen mitochondria showed that DIDS increased their capacity to take up potential-dependent dye DiOC5(3), i. e. caused hyperpolarization of mitochondrial membranes. At the same time DIDS influenced on intramitochondrial ROS content and excretion of ROS from mitochondria. Thus, NPPB and DIDS differently influenced on transmembrane potential distribution along pollen tube plasmalemma, on its osmotic balance, and on mitochondria functioning. This set of data suggests that pollen tube growth is dependent on activity of anion channels that differ in localization and functions.

[Membrane potential changes during pollen germination and tube growth].

We applied quantitative fluorescent microscopy to study membrane potential alterations during pollen germination and in growing pollen tube. Two voltage-sensitive dyes were applied: DiBAC4(3) was used to detect average membrane potential values in pollen grains and isolated protoplasts; Di-4-ANEPPS gave an option of membrane potential mapping on pollen protoplast and pollen tube surfaces. We have found out that tobacco pollen grain activation is accompanied by hyperpolarization of the vegetative cell plasma membrane by about 8 mV. Lily pollen protoplasts were significantly hyperpolarized (-108 mV) with respect to the pollen grains (-23 mV) from which they were isolated. We found polar distribution of the membrane potential along the protoplast surface, and longitudinal potential gradient along the pollen tube. In the presence of plasma membrane H(+)-ATPase inhibitor, sodium orthovanadate (1 mM) or its activator fusicoccin (1 microM), the longitudinal voltage gradient altered but did not disappear. Anion channel blocker, NPPB (40 microM), fully discarded the gradient in pollen tubes. Obtained results give evidence of the plasma membrane hyperpolarization during pollen germination and uneven potential distribution on pollen grain and tube surfaces. Inhibitory analysis showed involvement of the plasma membrane H(+)-ATPase and anion channels in membrane potential regulation.

Nonaqueous titration of amino groups in polymeric matrix of plant cell walls.

Nonaqueous titration was used for detection of free amino groups in the polymeric matrix of plant cell walls. The content of amino groups varied in the range 0.54-0.91 and total nitrogen in the range 1.0-4.2 mmol per gram dry mass of cell walls depending on the plant species. However, these data on the high content of free amino groups do not correlate with the present day concept that the nitrogen fraction in charged amino groups in plant cell wall proteins, which are assumed to be mainly amino groups of lysine and arginine residues, is about 10%. It is supposed that most detected free amino groups belong to the hydroxy-amino acids hydroxyproline and tyrosine that can be bound at the hydroxyl group with the carbohydrate part of glycoprotein or another structural cell wall polymer.

Controlling the unstable emission of a semiconductor laser subject to conventional optical feedback with a filtered feedback branch.

We show the advantages of controlling the unstable dynamics of a semiconductor laser subject to conventional optical feedback by means of a second filtered feedback branch. We give an overview of the analytical solutions of the double cavity feedback and show numerically that the region of stabilization is much larger when using a second branch with filtered feedback than when using a conventional feedback one.

[Formation of reactive oxygen species during pollen grain germination].

The formation of reactive oxygen species in pollen at the early germination stage, which precedes the formation of the pollen tube, was studied. During this period, pollen grain is being hydrated, abruptly increasing its volume, and it passes from the resting state to active metabolism. Fluorescent methods have made it possible to reveal reactive oxygen species in the cytoplasm and inner layer of the pollen wall, intine. The cytoplasmic reactive oxygen species were mostly found in mitochondria, while extracellular ones were localized in aperture zones of intine, as well as in the solution surrounding pollen grains in vitro. The content of extracellular reactive oxygen species decreased after superoxide dismutase (100 units per ml) and diphenylene iodonium (100 microM), which indicates NADPH oxidase as one of possible producent of them. In conditions of suppression of extracellular reactive oxygen species production (100 microM diphenilene iodonium) or their promoted removal (after addition of 10 to 100 microM ascorbic acid), the number of germinating pollen grains increased. This effect disappeared after further increase in the concentration of the listed reagents. The result is evidence of the significance of processes of generation/removal of extracellular reactive oxygen species for pollen germination.