30 research outputs found
Effect of annealing mode on ZnS-Cu,CI properties
Influence of annealing modes on spectral characteristics of photoluminescence, elec -troluminescence, and electron spin resonance of ZnS:CuCI and ZnS:CuCI₂ powders has been studied. The thermal doping processes and structure properties of ZnS have been shown to be influenced considerably by the sample heating and cooling rates during the anneal. Increasing of the above-mentioned rates results in increased concentrations of doublecharged copper and mangenese impurities in zinc sulfide. Moreover, it has been shown that the blue (λmax ~ 450 nm) emission centers are more sensitive to excitation by ac electric field (8 = 250 V, f = 5000 Hz) than to photoexcitation.Исследовано влияние режимов отжига порошков ZnS:CuCI и ZnS:CuCl₂ на спектральные характеристики их фотолюминесценции, электролюминесценции и электронного парамагнитного резонанса. Показано, что на процессы термического легирования, а также на структурные свойства ZnS, существенное влияние оказывает характер разогрева и остывания образцов в процессе их отжига. Увеличение скорости разогрева и остывания образцов в процессе их отжига приводит к возрастанию концентрации в сульфиде цинка двухзарядных примесей меди и марганца. Кроме того, в работе показано, что центры синего свечения с λmax ~ 450 нм более чувствительны к возбуждению переменным электрическим полем (U = 250 В, f = 5000 Гц), чем к фотовозбуждению.Досліджєно вплив режимів відпалу порошків ZnS:CuCI та ZnS:CuCI₂ на спектральні характеристики їх фотолюмінесценції, електролюмінесценції та електронного пара-магнітногго резонансу. Показано, що на процеси термічного легування, а також на структурні властивості ZnS, значний вплив має характер розігріву та охолодження зразків у процесі їх відпалу. Збільшення швидкості розігріву та охолодження зразків у процесі їх відпалу веде до збільшення концентрації у сульфіді цинку двозарядних домішок міді та марганцю. Крім того, у роботі показано, що центри синього світіння з λmax ~ 450 нм більш чутливі до збудження змінним електричним полем (U= 250 В,
f = 5000 Гц), ніж до фотозбудження
Plasma methionine depletion and pharmacokinetic properties in mice of methionine γ-lyase from Citrobacter freundii, Clostridium tetani and Clostridium sporogenes
PK studies were carried out after a single i.v. administration of 500 and 1000 U/kg by measuring of MGL activity in plasma samples. L-methionine concentration was measured by mass spectrometry. After single i.v. injection of 500 U/kg the circulating T1/2 of enzymes in mice varies from 73 to 123 min. The AUC0-tinf values determined for MGL 500 U/kg from C. freundii, C. tetani and C. sporogenes are 8.21 ± 0.28, 9.04 ± 0.33 and 13.88 ± 0.39 U/(ml × h), respectively. Comparison of PK parameters of three MGL sources in the dose of 500 U/kg indicated the MGL C. sporogenes to have better PK parameters: clearance 0.83(95%CI: 0.779–0.871) – was lower than C. tetanii 1.27(95%CI: 1.18–1.36) and C. freundii 1.39(95%CI: 1.30–1.49). Mice plasma methionine decreased to undetectable level 10 min after MGL 1000 U/kg injection. After MGL C. sporogenes 500 U/kg injection plasma methionine level completely omitted after 10 min till 6 h, assuming the sustainability of negligible levels of methionine ( < 5 μM) in plasma of mice for about 6 h. The recovery of methionine concentration showed the advantageous efficiency of MGL from C. sporogenes: 95% 0.010–0.022 vs 0.023–0.061 for MGL C. freundii and 0.036–0.056 for MGL C. tetani. There are no significant differences between methionine cleavage after MGL C. tetani and MGL C. sporogenes i.v. injection at all doses. MGL from C. sporogenes may be considered as promising enzyme for further investigation as potential anticancer agent. © 2017 Elsevier Masson SA
Plasma methionine depletion and pharmacokinetic properties in mice of methionine gamma-lyase from Citrobacter freundii, Clostridium tetani and Clostridium sporogenes
Different mechanisms of protective and differentiative activities of homological peptides TGENHR and TQVEHR
Previously we identified a six-membered fragment 354TQVEHR 359 of the C-terminal part of the PEDF (Pigment Epithelium-Derived Factor) differentiation factor molecule that shares homology with fragment 41TGENHR46 of the HLDF (Human Leukemia Differentiation Factor) differentiation factor molecule, which is responsible for its differentiation activity. HLDF has been isolated from the culture medium of human promyelocytic leukemia cell line HL-60. Hexapeptides HLDF-6 (TGENHR) and PEDF-6 (TQVEHR) corresponding to these HLDF and PEDF molecule fragments, which were previously shown to induce cell differentiation (Kostanyan et al. (2000) Russian Journal of Bioorganic Chemistry, 26, 505-511), also have neuroprotective properties. Both peptides prevent degeneration of Purkinje cells of rat cerebellar vermis upon chemical hypoxia induced by sodium azide in vivo; this effect is also observed on a behavioral level. Peptide HLDF-6 but not PEDF-6 promotes survival of HL-60 cells upon chemical hypoxia. Peptides HLDF-6 and PEDF-6 affect different second messenger biosynthesis systems in HL-60 cells. HLDF-6 diminishes cyclic AMP level in those cells due to adenylate cyclase inhibition, while PEDF-6 inhibits phosphatidylinositol-specific phospholipase C stimulated by aluminum tetrafluoride anions
Plasma methionine depletion and pharmacokinetic properties in mice of methionine γ-lyase from Citrobacter freundii, Clostridium tetani and Clostridium sporogenes
PK studies were carried out after a single i.v. administration of 500 and 1000 U/kg by measuring of MGL activity in plasma samples. L-methionine concentration was measured by mass spectrometry. After single i.v. injection of 500 U/kg the circulating T1/2 of enzymes in mice varies from 73 to 123 min. The AUC0-tinf values determined for MGL 500 U/kg from C. freundii, C. tetani and C. sporogenes are 8.21 ± 0.28, 9.04 ± 0.33 and 13.88 ± 0.39 U/(ml × h), respectively. Comparison of PK parameters of three MGL sources in the dose of 500 U/kg indicated the MGL C. sporogenes to have better PK parameters: clearance 0.83(95%CI: 0.779–0.871) – was lower than C. tetanii 1.27(95%CI: 1.18–1.36) and C. freundii 1.39(95%CI: 1.30–1.49). Mice plasma methionine decreased to undetectable level 10 min after MGL 1000 U/kg injection. After MGL C. sporogenes 500 U/kg injection plasma methionine level completely omitted after 10 min till 6 h, assuming the sustainability of negligible levels of methionine ( < 5 μM) in plasma of mice for about 6 h. The recovery of methionine concentration showed the advantageous efficiency of MGL from C. sporogenes: 95% 0.010–0.022 vs 0.023–0.061 for MGL C. freundii and 0.036–0.056 for MGL C. tetani. There are no significant differences between methionine cleavage after MGL C. tetani and MGL C. sporogenes i.v. injection at all doses. MGL from C. sporogenes may be considered as promising enzyme for further investigation as potential anticancer agent. © 2017 Elsevier Masson SA
COMBINED TREATMENT OF PATIENTS WITH NON-SMALL CELL LUNG CANCER WITH PERSONALIZED PRESCRIPTION OF ADJUVANT CHEMOTHERAPY
Objective: To study the long-term results of the combined treatment of non-small cell lung cancer (NSCLC) using pre-surgery chemotherapy, radical surgery and personalized adjuvant chemotherapy based on the level of monoresistance genes.
Methods: Four-year results of treatment of 72 patients of NSCLC II-III stage were analyzed. All patients underwent 2 courses of neoadjuvant chemotherapy (vinorelbine/carboplatin) and surgical treatment. Personalized adjuvant chemotherapy based on the levels of expression of monoresistance genes АВСС5, RRM1, TYMS, TOP1, TOP2α, TUBB3, BRCA1, and ERCC1 was performed in the main group (n=35). Three courses of adjuvant chemotherapy (vinorelbine/carboplatin) were performed in the control group (n=37).
Results: In the main group the progression of the disease was observed in 14 out of 35, and in the control group – in 21 out of 37 patients. Relapsefree survival (RFS) in the main group was 60.0% (95% CI: 43.6-74.5), in the control group – 43.2% (95% CI: 28.7-59.1); Log-Rank test χ2 =3,071, р=0,080; RR=1,808 (95% CI: 0.918-3.561). The median RFS in the control group was 27 months (95% CI: 5.7-48.3). The overall survival rate in the main group was 77.1% (95% CI: 61.0-87.9), in the control group – 54.1% (95% CI: 38.4-69.0); Log-Rank test χ2 =2,813, p=0.094; RR=2,024 (95% CI: 0,870-4,709).
Conclusion: The developed method of personalized prescribing adjuvant chemotherapy to patients with NSCLC based on the molecular genetic characteristics of the tumor improves relapse-free and overall survival
Different mechanisms of protective and differentiative activities of homological peptides TGENHR and TQVEHR
Previously we identified a six-membered fragment 354TQVEHR 359 of the C-terminal part of the PEDF (Pigment Epithelium-Derived Factor) differentiation factor molecule that shares homology with fragment 41TGENHR46 of the HLDF (Human Leukemia Differentiation Factor) differentiation factor molecule, which is responsible for its differentiation activity. HLDF has been isolated from the culture medium of human promyelocytic leukemia cell line HL-60. Hexapeptides HLDF-6 (TGENHR) and PEDF-6 (TQVEHR) corresponding to these HLDF and PEDF molecule fragments, which were previously shown to induce cell differentiation (Kostanyan et al. (2000) Russian Journal of Bioorganic Chemistry, 26, 505-511), also have neuroprotective properties. Both peptides prevent degeneration of Purkinje cells of rat cerebellar vermis upon chemical hypoxia induced by sodium azide in vivo; this effect is also observed on a behavioral level. Peptide HLDF-6 but not PEDF-6 promotes survival of HL-60 cells upon chemical hypoxia. Peptides HLDF-6 and PEDF-6 affect different second messenger biosynthesis systems in HL-60 cells. HLDF-6 diminishes cyclic AMP level in those cells due to adenylate cyclase inhibition, while PEDF-6 inhibits phosphatidylinositol-specific phospholipase C stimulated by aluminum tetrafluoride anions
Features of the cell composition of inflammatory infiltrate in different phases of diffuse alveolar lung damage with COVID-19
Background. Acute respiratory distress syndrome (ARDS) with COVID-19 has a worse prognosis than ARDS with other diseases. Mortality from ARDS with COVID-19 is 26.0 — 61.5%, and due to other causes — 35.3—37.2%. Objective. To find of the correlation between polymorphonuclear leukocytes (PMNs), lymphocytes, and macrophages in the cellular composition of the inflammatory infiltrate at different stages and phases of diffuse alveolar damage (DAD) with COVID-19, analyzing the autopsy material. Material and methods. The lung tissue of 25 patients who died from ARDS with COVID-19 without a secondary bacterial or mycotic infection, another thanatologically significant pathology of the lungs, was studied. To study the cellular composition of the inflammatory infiltrate and the dynamics of its changes a double immunohistochemical analysis of the expression of antibodies to CD15, CD3, and CD68 was used. Results. The inflammatory infiltrate and intraalveolar exudate in the exudative phase of DAD was represented by 56.8% of PMNs (CD15-positive cells; hereinafter — the average value of the percentage of positive cells to the total number of cells of the inflammatory infiltrate), 6.9% — lymphocytes (CD3-positive cells) and 19.5% macrophages (CD68-positive cells). In the early stage of the proliferative phase: 14.1% PMNs, 38.7% lymphocytes and 13.5% macrophages. In the late stage of the proliferative phase: 11.3% PMNs, 14.5% lymphocytes and 39.3% macrophages. Conclusions. In the exudative phase of DAD a statistically significant predominance of PMN was revealed, which could determine the main volume of lung damage and the severity of ARDS with COVID-19. In the early stage of the proliferative phase of DAD, a statistically significant change in the composition of the inflammatory infiltrate was revealed to compare with the exudative phase: a significant decrease in the content of PMNs relative to the total number of cells in the inflammatory infiltrate; an increase in the number of lymphocytes, which is probably associated with the start of organization and repair processes. In the late stage of the proliferative phase of DAD, compared with its early stage, was revealed a statistically significant increase in the number of macrophages in ratio. © 2022, Media Sphera Publishing Group. All rights reserved