A lyophilized form of xenogeneic total RNA stimulates hematopoiesis in post-radiation myelosuppression

Введение. Аллогенная суммарная РНК, выделенная из клеток лимфоидных органов, стимулирует регенерацию кроветворной ткани после острого и хронического нарушения кроветворной функции. Цель исследования: 1) доказательство отсутствия ксеногенных ограничений механизмов лимфоцитарного контроля регенеративных процессов на примере гемостимулирующего действия суммарной РНК лимфоцитов бычьей селезенки в отношении кроветворения крыс, подвергшихся гамма-облучению в сублетальной дозе; 2) сравнительный анализ эффективности нативной и лиофилизированной форм указанной РНК. Методика. Работа выполнена на белых нелинейных крысах-самцах массой 200-220 г. Cуммарную РНК выделяли методом фенол - хлороформной экстракции из лимфоидных клеток бычьей селезенки. Для создания исходной миелосупрессии 30 крыс подвергли однократному общему воздействию гамма-излучения с источником 60Co в дозе 6 Гр при мощности дозы 0,1 Гр/с, после чего разделили их на 3 равные группы. Через 2 ч после облучения крысам контрольной группы внутрибрюшинно ввели по 0,5 мл 0,9% NaCl; крысам 2-й группы - нативную суммарную РНК в дозе 30 мкг/100г массы, крысам 3-й группы - лиофилизированную суммарную РНК в аналогичной дозе. На 3-и, 7-е и 12-е сут в периферической крови определяли количество ретикулоцитов, лейкоцитов и тромбоцитов, после чего крысы были выведены из эксперимента с целью исследования костномозгового кроветворения. Через 12 сут в костном мозге определяли количество эритроидных, лимфоидных, мегакариоцитарных и миелоидных клеток. Из костного мозга выделяли эритробластические островки (ЭО) и дифференцировали их на пролиферирующие (ЭО 1,2 классов и реконструирующиеся ЭО) и зрелые (ЭО 3 класса и инволюциирующие ЭО) морфо-функциональные клеточные ассоциации. Результаты. Под влиянием ксеногенной суммарной РНК в периферической крови крыс в 2-3 раза увеличилось количество лейкоцитов и в 1,6-1,75 раза возросло число ретикулоцитов. В костном мозге увеличилось количество пролиферирующих миелоидных и лимфоидных элементов, а также общее число клеток эритроидного ряда. Ксеногенная суммарная РНК стимулировала образование ЭО как на основе контакта свободных костномозговых макрофагов с молодыми эритроидными клетками (ЭО 1 и 2 классов), так и на базе реконструкции (ЭО реконструирующиеся). Сравнительный анализ эффектов нативной и лиофилизированной суммарной РНК не выявил различий между гемопоэтическими показателями у крыс, получивших эти препаратов. Заключение. Суммарная РНК, выделенная из лимфоидных клеток бычьей селезенки, активирует гемопоэз у крыс с постлучевой миелосупрессией, что свидетельствует об отсутствии ксеногенных ограничений у млекопитающих в механизмах лимфоцитарного контроля восстановительных процессов. Лиофилизированная суммарная РНК активирует костномозговое кроветворение в те же сроки и в том же объеме, что и нативная форма. Introduction. Allogeneic total RNA isolated from cells of lymphoid organs stimulates regeneration of hematopoietic tissue after acute and chronic disturbance of hematopoietic function. Aim. 1) To prove the absence of xenogeneic limitation for the lymphocytic regulation of regenerative processes using an example of the hemo-stimulating effect of total RNA from bovine spleen lymphocytes on hematopoiesis in rats exposed to sublethal gamma-irradiation; 2) To perform a comparative analysis of the effectiveness of the native and lyophilized forms of the total RNA. Methods. Experiments were performed on white outbred male rats weighing 200-220 g. Total RNA was isolated from bovine spleen lymphoid cells by phenol-chloroform extraction. To create the initial myelosuppression, 30 rats were exposed to a single general 60Co gamma radiation (6 Gy at 0.1 Gy/s). The rats were then divided into 3 equal groups. Two hrs after irradiation, the rats of the control group were injected intraperitoneally with 0.5 ml of 0.9% NaCl; rats of the second group received native total RNA, 30 μg/100 g body weight, and rats of the third group received lyophilized total RNA at a similar dose. On days 3, 7, and 12, the number of peripheral blood reticulocytes, leukocytes, and platelets was measured. The rats were then sacrificed, and bone marrow hematopoiesis was studied. After 12 days, the number of bone marrow erythroid, lymphoid, megakaryocytic, and myeloid cells was measured. Erythroblastic islets (EIs) were isolated from the bone marrow and differentiated into proliferating (class 1 and 2 EIs and reconstructing EIs) and mature (class 3 EIs and involving EIs) morpho-functional cell associations. Results. Under the influence of xenogeneic total RNA, the number of peripheral blood leukocytes increased by 2-3 times, and the number of reticulocytes increased by 1.6-1.75 times. In the bone marrow, the number of proliferating myeloid and lymphoid cells increased, as did the total number of erythroid cells. Xenogeneic total RNA stimulated formation of EIs, based both on the contact of free bone marrow macrophages with young erythroid cells (class 1 and 2 EIs) and on reconstruction (reconstructing EIs). Comparative analysis of the effects of native and lyophilized total RNA did not reveal differences between hematopoietic parameters in rats that received these agents. Conclusion. Total RNA isolated from bovine spleen lymphoid cells activates hematopoiesis in rats with post-radiation myelosuppression. This indicates the absence of mammalian xenogenic limitation of lymphocytic control of recovery processes. Lyophilized total RNA activates bone marrow hematopoiesis at the same rate and to the same extent as the native form.

Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the NRC, Canada and the BIPM in 60Co gamma radiation

Main text A new key comparison of the standards for absorbed dose to water of the National Research Council of Canada (NRC), Canada and the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in October 2020. The comparison result, based on the calibration coefficients for three transfer standards and evaluated as a ratio of the NRC and the BIPM standards for absorbed dose to water, is 0.9995 with a combined standard uncertainty of 3.4 parts in 103. The result agrees within the uncertainties with the comparison carried out in 2009. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the NRC, Canada and the BIPM in 60Co gamma radiation

Main text A new key comparison of the standards for air kerma of the National Research Council of Canada (NRC), Canada and the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in October 2020. The comparison result, based on the calibration coefficients for three transfer chambers and expressed as a ratio of the NRC and the BIPM standards for air kerma, is 1.0022 with a combined standard uncertainty of 2.2 parts in 103. The result agrees within the uncertainties with the indirect comparison carried out in 2009. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Effects of Gamma Radiation-Induced Crosslinking of Collagen Type I Coated Dental Titanium Implants on Osseointegration and Bone Regeneration

This study aimed to compare two methods of crosslinking collagen type I on implanted titanium surfaces, that is, using glutaraldehyde (GA) or gamma-rays (GRs), in a beagle dog model. For in vivo experiments, implants were allocated to three groups and applied to mandibular bone defects in beagle dogs; Group SLA; non-treated Sandblasted, large grit, acid-etched (SLA) implants, Group GA; SLA implants coated with GA crosslinked collagen type I, Group GR; SLA surface implants coated with collagen type I and crosslinked using 25 kGy of 60Co gamma radiation. New bone μCT volumes were obtained, and histologic and histometric analyses were performed in regions of interest. The GR group had significantly better new bone areas (NBAs) and bone to implant contact (BIC) results than the SLA group (p < 0.05), but the GA and GR groups were similar in this respect. New bone volumes and inter-thread bone densities (ITBD) were non-significantly different in the three groups (p > 0.05). Within the limits of this study, gamma-ray collagen crosslinking on titanium implants can be considered a substitute for glutaraldehyde crosslinking.

Assessment of 60Co gamma radiation on early phenological stages of two generations of OFADA rice

Traditional Ofada rice varieties from South-West, Nigeria is preferred for its unique taste, aroma and massive potential for export but has low yield. Based on this background, two Ofada rice varieties, FUNAABOR 1 and FUNAABOR 2 were irradiated to create genetic variability as it affects vegetative traits. Seeds from the varieties were exposed to nine levels of 60Co gamma irradiation (0, 50, 100, 150, 200, 250, 300, 350 and 400 Gy). The seeds were nursed for 30 days before M1 seedlings were transplanted into a well tilled soil in a two factorial RCBD with three replicates. Selections from M1 plants were used to establish M2 plants generation. The results revealed diverse effects of 60Co gamma irradiation treatments on different plant vegetative traits. The establishment rates of M1 Ofada rice population were unaffected (p > 0.01) by increasing gamma irradiation from 0 to 300 Gy but decreased at 350 Gy. Above 300 Gy, tiller numbers, plant height, lodging incidence, leaf number, leaf length and leaf angle decreased significantly when compared with control (p < 0.01) in both generations (M1 and M2). Moderately tillered (10 tillers), tall plant (116.9 cm) obtained from 350 dosage rate recorded highest grain weight of 7.8 g per panicle. High phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) promoted by the irradiation dosages in M1 selection indicate the extent of environmental influence. High broad sense heritability observed from leaf number, leaf angle, leaf length, leaf blade colour, basal leaf sheath colour and grain weight per panicle shows possibility of rapid genetic improvement of these characters through selection.