Polarization-Sensitive Photoluminescence from Aligned Carbon Chains Terminated by Gold Clusters.

We synthesize a thin film composed of long carbyne chains terminated by gold clusters and study its optical properties. The presence of gold particles stabilizes longer chains and leads to their alignment. We show that the gold clusters also act as a source of electron doping, thus, changing the intensity of photoluminescence from quadratic dependence on the pumping intensity without gold to linear with gold. We also observe that the excitation of the film at the gold plasmon frequency causes the blue shift of photoluminescence and estimate, on the basis of this effect, the minimum length of the carbyne chains. The high degree of alignment of the gold-terminated carbyne chains results in strongly anisotropic light absorption characterized by a distinctive cosine dependence on the angle between the carbyne molecule and polarization plane of the excitation. This paves the way for a new class of ultimately thin polarization sensitive emitters to be used in future integrated quantum photonics devices.

Ischemia-Modified Albumin and Antioxidant Protection in Newborns with Asphyxia of Varying Severity.

The content of ischemia-modified albumin (IMA), serum albumin, and antioxidant capacity of blood serum was studied in healthy newborns and in newborns with moderate and severe asphyxia on days 1-2 and 3-4 of the postnatal period. Changes in these indicators were found in both groups of newborns with birth asphyxia in comparison with the group of healthy newborns and were more pronounced in children with severe asphyxia. An increase in the IMA level (by 1.6 times; p<0.001) and antioxidant capacity of blood serum (by 2.4 times; p<0.001) and a decrease in serum albumin content (by 1.5 times; p<0.001) were found in severe asphyxia on days 1-2. Analysis of changes in these indicators by days 3-4 allows to talk about a decrease in the intensity of free-radical reactions in newborns with birth asphyxia during complex therapy.

Changes in the Number of Residual γH2AX Foci in Ki-67-Positive and Ki-67-Negative Human Fibroblasts Irradiated with X-Rays in Doses of 2-10 Gy.

We studied changes in the number of residual γH2AX foci in cultured human fibroblasts with different expression of the cell proliferation marker protein Ki-67 24, 48, and 72 h after exposure to X-ray radiation in doses of 2-10 Gy. It was shown that, regardless of the expression of Ki-67, the number of residual γH2AX foci in irradiated cells linearly depends on the absorbed dose of X-ray radiation. However, the quantitative yield of residual γH2AX foci per unit of the absorbed dose in Ki-67+ cells 24 and 48 h after irradiation was higher than in Ki-67- cells by 1.8 and 2.0 times, respectively. In Ki-67- cells, the quantitative yield of residual γH2AX foci per unit of absorbed dose decreases by ~1.7 times with increasing the time after irradiation from 24 to 72 h. For the purposes of practical radiation biodosimetry, it can be recommended to quantify residual γH2AX foci in non-proliferating cells at least 72 h after irradiation.

Binding of Iron (II) Ions by Aqueous Extractions from Yerba Mate (Ilex paraguariensis).

We studied the ability of an aqueous extract from yerba mate and a dry extract obtained on the basis of this aqueous extract to remove Fe(II) ions from an aqueous medium. Aqueous extracts from mate dose-dependently reduced the concentration of free Fe(II) ions assayed by the reaction with 1,10-phenanthroline. This can be attributed to polyphenolic compounds with iron-chelating properties present in aqueous extracts from mate, namely quercetin, rutin, caffeic and chlorogenic acids. These substances effectively removed Fe(II) ions from the medium (the initial concentration of these ions was 15 µM) in the concentration range of 20-30 µM. Binding of Fe(II) ions by aqueous mate extracts (due to the formation of chelate complexes with the participation of polyphenolic compounds) modified their absorption spectra in the visible region. Binding of Fe(II) ions can be a mechanism of the antioxidant action of yerba mate.

DNIC is a Structure Providing Specificity of Physiological Effects of NO.

Metabolism of nitric oxide (NO) donors: dinitrosyl iron complexes (DNIC), nitrosothiols (RSNO), and nitroprusside was studied on a chick embryo model. The obtained results give reason to assume that DNIC constituting the main pool of nitroso compounds in the vast majority of tissues are NO donors immediately interacting with the physiological target of NO, and other NO donors can perform this function after their transformation into DNIC. NO is released from DNIC not spontaneously, but under a joint influence of a factor destroying the complex and a target having chemical affinity for NO. A similar mechanism is apparently implicated in NO passage through the cell membrane.

Phenotypic Characteristics of Dormant Human Non-Small Cell Lung Cancer Cells Surviving Multifraction X-Ray Irradiation.

Phenotypic characteristics of human non-small cell lung cancer cells, A549 (p53 wild-type) and H1299 (p53-deficient) as well as their descendants surviving after multifraction X-ray irradiation at a cumulative dose of 60 Gy (sublines A549HR and H1299HR, respectively) were studied before and after additional 2 Gy single dose irradiation. In 24 h after the additional irradiation, we observed a significant increase in the proportion of cells with signs of entosis (by 5 times, p<0.05) and SA-ß-gal+ cells (by 1.6 times, p<0.01) in the general population of A549HR cells. In contrast, a significant increase in the proportion of only SA-ß-gal+ multinucleated giant cancer cells was revealed in the parental A549 cells. Additional single dose irradiation resulted in a significant (by 1.8 times, p<0.05) increase in the proportion of multinucleated giant cancer cells in H1299HR cells in comparison with their parental H1299 cells. These changes did not correlate with changes in the proportion of entotic cells, because their high basal content in the absence of functional p53 did not change in response to additional single dose irradiation. At the same time, both p53-deficient non-small cell lung cancer cell lines showed a significant (2.9-fold for H1299 and 5.5-fold for H1299HR cells, p<0.001) increase in the proportion of SA-ß-gal+ cells in the general population, but not in the multinucleated giant cancer cells population.

The possibility of diagnosing intrauterine infection by the content of nitrite and non-thiolate nitroso compounds in maternal blood plasma.

The aim of the study is to develop a method for early diagnosis of intrauterine infection (IUI). A study of markers of inflammation in the venous blood of 60 pregnant women was conducted. The study was followed by a retrospective assessment of the outcomes of pregnancies and childbirth. Of these, 33 patients with a gestation period of more than 37 weeks (full-term pregnancy) and, accordingly, 27 patients from whom the blood sample was taken at a period of less than 37 weeks - patients with the threat of premature birth (PB). PB is the main factor contributing to the development of IUI. 27 patients were diagnosed with premature rupture of the membranes (PROM). Of these, 15 are with the threat of PB. 8 of them had a diagnosed IUI. In all cases of diagnosed PROM, including those with IUI, the concentration of nitrite and nontiolate nitroso compounds (NO2-+RNO) in the mother's blood plasma was 2.3±1.2 µM, while normally it does not exceed 0.1 µM (p<0.001). Regardless of the duration of pregnancy. The use of antibiotics in the case of PROM contributed to the normalization of the concentration (NO2-+RNO). Therefore, increasing of this indicator is result of bacterial infection. Indications of other markers of inflammation: the number of leukocytes in venous blood and in a smear of vaginal contents, the level of C-RB did not significantly change in both PROM and IUI (p>0.1). Since the concentration index (NO2-+RNO) increased in almost all cases of PREM, unlike all other clinical and biochemical indicators used in modern medicine, there is an obvious sense of its use for the current monitoring of the health of pregnant women. But it is still impossible to say unequivocally about the possibility of monitoring the fetal health by concentration (NO2-+RNO) in the mother's blood.

[Forensic medical characteristics of fatal injuries in a traffic accident in the car cabin]. / Sudebno-meditsinskaya kharakteristika smertel'nykh povrezhdenii, prichinennykh pri dorozhno-transportnom proisshestvii v kabine legkovogo avtomobilya.

The study objective is to identify the most common fatal injuries in car accidents and observe the trends of the proportion of deaths at the scene, in an ambulance, and a hospital. We analyzed all forensic examination reports (protocols) of those who died in the car due to a traffic accident in Moscow from 2018 to 2020. Male drivers died 15 times more often than female drivers, and male passengers died twice as often as females. Most of the victims were young and middle-aged. Both drivers and passengers most commonly had traumatic brain injury with fractures of the bones of the vault and base of the skull, intracranial hemorrhages, crushing, and dislocation of the damaged brain. At the scene of traffic accidents, the cause of death was fatal bodily injuries. An increased risk of fatal traffic accidents was identified in autumn and winter.

Transcriptomic Analysis of DNA Repair Pathways in Human Non-Small Cell Lung Cancer Cells Surviving Multifraction X-Ray Irradiation.

Radioresistant sublines of non-small cell lung cancer cells differing in the p53 status were obtained: A549 (p53 wild type) and H1299 (p53 deficient). The exposure to ionizing radiation was carried out using a standard protocol developed on the basis of empirical clinical experience and consisting in exposure in a dose of 2 Gy once a day, 5 days a week up to total dose of 60 Gy. The cells survived after irradiation demonstrated reduced radiosensitivity, as well as changes in differential gene expression in comparison with parental cells. Some differences in the signaling pathways involved in DNA repair were revealed.

Comparative Study of the Effect of Snake Venoms on the Growth of Ciliates Tetrahymena pyriformis: Identification of Venoms with High Antiprotozoal Activity.

To search for compounds with antiprotozoal activity, effects of snake venoms on the ciliates Tetrahymena pyriformis was studied. T. pyriformis from subkingdom of Protozoa, including the protozoal pathogens, was used as a model organism to select the venoms that are the most active against parasitic protozoans. Various concentrations of venoms were added to the cells, and the cells that survived after 24 h were counted. Among the six snake species from the Viperidae family, the venom of the viper Vipera berus, which completely killed the cells at 49 µg/mL, was the most active. Among four species from the Elapidae family, the previously studied cobra venoms containing cytotoxins with strong antiprotozoal activity as well as the venom of krait Bungarus multicinctus (10 µg/mL) were the most active. The venoms of the pit vipers and Nikolsky's viper did not show any activity at 12.5 mg/mL. Thus, the venoms of V. berus and B. multicinctus are promising for the isolation of new antiprotozoal compounds.

Increased Yield of Residual γH2AX Foci in p53-Deficient Human Lung Carcinoma Cells Exposed to Subpicosecond Beams of Accelerated Electrons.

We studied quantitative yield of residual (24 h post-irradiation) phosphorylated histone (γH2AX) foci as a marker of DNA double strand breaks in wild-type A549 and p53-deficient H1299 human lung carcinoma cells after exposure to subpicosecond (energy 4 MeV, pulse duration 400 fsec, peak dose rate during the pulse 16 GGy/s) and quasi-continuous (energy 3.6 MeV) beams of accelerated electrons in a dose range of 0.5-10.0 Gy. The efficiency of pulse irradiation in A549 and H1299 cells assessed by the yield of residual foci was higher than the efficiency of quasi-continuous exposure by 1.8 and 5.3 times, respectively. Significant differences in quantitative yield of residual γH2AX foci between wild-type and p53-deficient cell lines were observed only after exposure to subpicosecond, but not quasi-continuous beams of accelerated electrons.

Tightly Focused Femtosecond Laser Radiation Induces DNA Double-Strand Breaks in Human Tumor Cells.

We studied the formation of double-strand DNA breaks (DNA DSB) induced by femtosecond laser radiation in A549 human lung adenocarcinoma cells using immunocytochemical staining of the resulting tracks of a specific DSB marker protein phosphorylated ATM kinase (phospho-ATM). Additionally, colocalization of phospho-ATM tracks with γH2AX protein tracks was studied. The results of immunocytochemical analysis showed that 30 min after irradiation of cells with femtosecond pulses with energies of 1 and 2 nJ (radiation power density 2×1011 and 4×1011 W×cm-2, respectively), the formation of tracks consisting of phospho-ATM and γH2AX proteins located in sites where the laser beam passes through the cell nuclei was observed. The presence of phospho-ATM tracks co-localized with γH2AX allows us to conclude that exposure to focused femtosecond infrared laser radiation with a pulse energy of 1-2 nJ leads to the formation of DNA DSB in irradiated cells.

New Plant Species Showing Antiprotozoian Activity.

The effects of extracts of ten plant species from Russia and five species from Vietnam on the growth and survival of ciliates Tetrahymena pyriformis were studied. T. pyriformis belongs to the subkingdom Protozoa, which also includes pathogens of protozoan infections. Extraction of dried plants was carried out with acidic and alkaline aqueous solutions, as well as with an aqueous ethanol. Various amounts of extracts were added to the ciliate cells, and the number of cells survived after incubation for 1 and 24 h was recorded. We found that our samples of several plants, including wormwood, harmala, and licorice, similarly to those studied earlier, exhibit antiprotozoal activity, which may indicate that the secondary metabolites are the same in plants from different regions. Using the ciliate T. pyriformis as a model organism, the presence of antiprotozoal activity in extracts of lilac, chondrilla, cinquefoil, hop, and elm was shown for the first time.

DNA Damage in Splenocytes of Mice Exposed to Secondary Radiation Created by 650 MeV Protons Bombarding a Concrete Shielding Barrier.

The proportion of splenocytes with a high level of DNA double-strand breaks was determined in mice exposed to primary and secondary radiation created by bombarding of a concrete barrier (thickness 20, 40, and 80 cm) by 650 MeV protons. The proportion of splenocytes with a high level of DNA double-strand breaks was assessed by flow cytometric analysis of γH2AX+ and TUNEL+ cells. It is shown that concrete barrier can significantly reduce primary proton radiation; the severity of negative biological effects in mice irradiated in the center of the proton beam decreased with increasing the thickness of this barrier. However, the spectrum of secondary radiation changes significantly with increasing the barrier thickness from 20 to 80 cm and the distance from central axis of the beam from 0 to 20 cm, and the proportion of the neutron component increases, which also causes negative biological effects manifesting in a significant (p<0.05) increase in the percentage of splenocytes with a high level of DNA damage in mice irradiated at a distance of 20 cm from the center of the proton beam and receiving relatively low doses (0.10-0.17 Gy).

Comparative Study of the γH2AX Foci Forming in Human Lung Fibroblasts Incubated in Media Containing Tritium-Labeled Thymidine or Amino Acids.

We compared the formation of γH2AX foci (marker of DNA double-strand breaks) in human lung fibroblasts (MRC-5 line) during their 24-h incubation in a medium containing 3H-labeled thymidine or amino acids (glycine, alanine, and proline) with specific radioactivity from 100 to 400 MBq/liter. A linear dependence of changes in the number of γH2AX foci on the specific radioactivity of the medium was revealed. The quantitative yield of DNA double-strand breaks under the influence of 3H-thymidine was more than 2-fold higher than under the influence of 3H-labeled amino acids. Comparative analysis of the yields of DNA double-strand breaks during cell incubation with 3H-labeled amino acids showed that 3H-alanine produced more pronounced effect that 3H-proline, which is consistent with the data on the content of their non-radioactive analogs in chromatin proteins.

Long-Term Persistence of Increased Number of γH2AX+ Peripheral Blood Lymphocytes in Monkeys Exposed to Negative Factors of Space Flights: Ionizing Radiation and Simulated Hypogravity.

We studied the influence of ionizing radiation and hypogravity as negative factors of space flights on DNA damage in peripheral blood lymphocytes of rhesus monkeys at different times after exposure (from 1 to 446 days). The proportion of cells with high numbers of DNA double-strand breaks (DSB), positive for the surrogate DSB marker-protein γH2AX, was monitored using flow cytometry. Some animals were exposed to 7-day antiorthostatic hypokinesia simulating hypogravity, the others to a combined effect of antiorthostatic hypokinesia, whole-body γ-irradiation (2.34 cGy/h, dose 1 Gy), and irradiation of the head with 12C ions (450 MeV, dose 1 Gy). Exposure to antiorthostatic hypokinesia led to a significant increase in the proportion of γH2AX+ lymphocytes only on the first day after exposure, whereas after combined exposure, increased numbers of damaged lymphocytes were recorded up to 42 days after exposure.

Colony-Forming Ability and Residual Foci of DNA Repair Proteins in Human Lung Fibroblasts Irradiated with Subpicosecond Beams of Accelerated Electrons.

We performed a comparative study of the colony-forming ability and the number of residual foci of DNA repair proteins in cultured human lung fibroblasts (MRC-5 cell line) after exposure to subpicosecond beams of accelerated electrons with an energy of 3.6 MeV and quasi-continuous radiation (accelerated electrons with an energy of 4 MeV and X-rays). The yield of damages causing reproductive cell death after pulsed subpicosecond radiation exposure was higher by ~1.8 times than after quasi-continuous radiation exposure. The quantitative yield of residual γH2AX foci (phosphorylated H2AX histone, a protein marker of DNA double breaks) in cells irradiated with subpicosecond beams of accelerated electrons was shown to be ~2.0- 2.5-fold higher than in cells irradiated with quasi-continuous beams of accelerated electrons.

Putative Role of Ligands of DNIC in the Physiological Action of the Complex.

In a relatively isolated system of avian embryo, the metabolism of NO, a component of the dinitrosyl iron complexes (DNIC), the main NO donor in most tissues, depends on the ligands that make up the complex. This fact corroborates the earlier hypothesis that these ligands perform a regulatory function in NO metabolism. It is also shown that nitrite injected into the embryo is not oxidized to nitrate like NO in DNIC, but is accumulated outside the amniotic sac. Normally, nitrite is present in an embryo in trace amounts. These facts suggest that NO in the embryo is transferred from the donor molecule to a target in the embryo tissues further transformed with minimum oxidation to nitrite.

Tipping the immunostimulatory and inhibitory DAMP balance to harness immunogenic cell death.

Induction of tumor cell death is the therapeutic goal for most anticancer drugs. Yet, a mode of drug-induced cell death, known as immunogenic cell death (ICD), can propagate antitumoral immunity to augment therapeutic efficacy. Currently, the molecular hallmark of ICD features the release of damage-associated molecular patterns (DAMPs) by dying cancer cells. Here, we show that gemcitabine, a standard chemotherapy for various solid tumors, triggers hallmark immunostimualtory DAMP release (e.g., calreticulin, HSP70, and HMGB1); however, is unable to induce ICD. Mechanistic studies reveal gemcitabine concurrently triggers prostaglandin E2 release as an inhibitory DAMP to counterpoise the adjuvanticity of immunostimulatory DAMPs. Pharmacological blockade of prostaglandin E2 biosythesis favors CD103+ dendritic cell activation that primes a Tc1-polarized CD8+ T cell response to bolster tumor rejection. Herein, we postulate that an intricate balance between immunostimulatory and inhibitory DAMPs could determine the outcome of drug-induced ICD and pose COX-2/prostaglandin E2 blockade as a strategy to harness ICD.

Behavioral Responses and Immune and Cytogenetic Parameters of Food-Restricted Mice.

The experiments on mice showed that subchronic food restriction to 40 and 8% of unrestricted ration is a strong stressor inducing devastation of lymphoid organs, primarily the thymus and spleen. The mice in the group with severe food restriction (8% of normal ration) demonstrated increased front paw grip force. We also observed an increase in spontaneous motor activity in these animals correlated with food restriction. Food deprivation led to inhibition of proliferative activity of the bone marrow cells and suppression of erythropoiesis. Moreover, severe food restriction was accompanied by a decrease in the number of double-strand DNA breaks evaluated by the release of γH2AX+-cells and the ratio of polychromatophilic erythrocytes.