A comprehensive program of optimization the brain oxygen status in newborns with respiratory disorders based on targeting regional oxygenation

NIRS provides the ability to obtain information about the brain oxygen status non-invasively. Therefore, potentially, this technology can make it possible to correct therapy that affects the blood and oxygen supply to the brain.The aim of our study was to develop a guideline for a dynamic monitoring of the oxygen status based on regional oxygenation data, as well as an effective therapeutic tool for newborns with respiratory distress.78 newborns with respiratory disorders were included (37 late preterm and 41 full-term) in this observational cohort study. In addition to a standard cardiorespiratory monitoring, a simultaneous monitoring of abdominal and cerebral oxygenation was performed during the early neonatal period.The developed treatment guideline was based on a multisystem approach in diagnosis and optimization of the brain oxygen delivery and consumption. The proposed algorithm focused on maintaining an adequate perfusion pressure, cardiac output, oxygen, and carbon dioxide content in the arterial blood in newborns with respiratory disorders.Implementing the developed treatment guideline in the neonatal intensive care units should increase the treatment effectiveness in newborns with respiratory disorders.Implementation developed treatment guideline in the neonatal intensive care units should increase the effectiveness of treatment in newborns with respiratory disorders.

Phosphonated mesoporous silica nanoparticles bearing ruthenium complexes used as molecular probes for tracking oxygen levels in cells and tissues

Phosphonated mesoporous silica nanoparticles bearing ruthenium complexes in their pores were prepared as biocompatible molecular probes to visualize oxygen status in cells and tissues.

Modeling the Effect of Hypoxia and DNA Repair Inhibition on Cell Survival After Photon Irradiation

Mechanistic approaches to modeling the effects of ionizing radiation on cells are on the rise, promising a better understanding of predictions and higher flexibility concerning conditions to be accounted for. In this work we modified and extended a previously published mechanistic model of cell survival after photon irradiation under hypoxia to account for radiosensitization caused by deficiency or inhibition of DNA damage repair enzymes. The model is shown to be capable of describing the survival data of cells with DNA damage repair deficiency, both under norm- and hypoxia. We find that our parameterization of radiosensitization is invariant under change of oxygen status, indicating that the relevant parameters for both mechanisms can be obtained independently and introduced freely to the model to predict their combined effect.

Assessment of the oxygen status of the brain during the oral cavity sanation in children aged 3–7 years under general anesthesia on an outpatient setting

Summary. Unfortunately, today, mental and behavioral disorders in children are quite common. It is proved that one of the main causes of cognitive decline is the disease of the small vessels of the brain. In the literature, there are data on the study of the relationship of cognitive impairment due to functional changes on the background of oxygen starvation of the brain. The aim of the study – the article presents the rationale for the need to limit the time for oral rehabilitation in an outpatient setting under general anesthesia in order to preserve the cognitive functions of the brain of the child due to its functional changes in violation of the oxygen status of cerebral vessels. Materials and Methods. The oral cavity sanation in the conditions of general anesthesia was conducted in 39 children aged 3–7 years on the basis of the Dental Medical Center at the National Medical University named after O. O. Bohomolets. This age group of children according to the classification of temperament (Thomas and Chess, 1997) includes: 11 children with “mild” temperament; 19 children – with «difficult» temperament; 9 children – temperament «long warms up». In order to monitor the oxygen status of the brain, cerebral oximetry was used. Results and Discussion. The linear decrease of rSO2 occurs from 43 minutes. To 60 min. rSO2 = (58.6±0.01) %, with a possible minimum value of 60.26 %. Min rSO2 within the normal range = (60.26±0.22) % is between 57 and 58 minutes. Therefore, in order to prevent the occurrence of brain hypoxia, dental rehabilitation of the oral cavity for children aged 3–7 years should be performed within (40±15) min. Respiratory complications (laryngospasm) in 10.25 % of children were noted during the rehabilitation of the oral cavity under general anesthesia. The mean rSO2 for laryngospasm is (68.83±7.39) %, which is 8.63 % relative to the mean rSO2 of the respective age group (rSO2 = (75.33±2.68) %). SO rSO2 of 16 min. 33 minutes each (≤20 min) by 11.42 % (rSO2 = (60.57±5.44) %). The peak of the decline occurred in 20–21 min. (rSO2 = (53.5±2.45 %) and accounted for 28.97 % of the total group value and 11.67 % of rSO2 directly for laryngospasm. In 75 % of children who had complications in the form of laryngospasm during the rehabilitation of the oral cavity under general anesthesia were noted ≤ 2 weeks after complete recovery for acute respiratory diseases (ARD). In order to study the effect of inflammatory processes of the respiratory tract on the possibility of complications in the process of dental rehabilitation in the outpatient setting under general anesthesia, we selected a group of children who had a history of ≥2 weeks but ≤ 4 weeks (group I) and analyzed the results indices of rSO2 with a group of children who had a history of ARD with a history of ≤ 2 weeks (group II) relative to those of rSO2 in the general group of children aged 3–7 years (group III). rSO2 in children of group I – (68.65±7.72) % ↓ rSO2 from 16 min to 32 minutes (≤20 min) is 14.59 % (rSO2 = (58.63±4.55) %). In the group II of children, rSO2 (74.92±6.84) %) coincides with rSO2 (74.84±6.63) %) in group III. Conclusions. Dental sanitation of the oral cavity under general anesthesia on an outpatient basis for children aged 3–7 years has a time limit (40±15) min. A contraindication for routine oral sanitation under general anesthesia on an outpatient basis is the presence of acute respiratory infections in the history of ≤ 2 weeks. In acute dental conditions, if there is a history of acute respiratory infections ≤ 2 weeks, ambulance care on an outpatient basis under general anesthesia is possible within 15 minutes. SpO2 values do not correlate with rSO2 indicators. The method of cerebral oximetry makes it possible to early detect changes in the oxygen balance of the brain and support it in time. The method of cerebral oximetry makes it possible to early detect changes in the oxygen balance of the brain and support it in time.

Decreased β-Cell Proliferation and Vascular Density in a Subpopulation of Low-Oxygenated Male Rat Islets

Low-oxygenated and dormant islets with a capacity to become activated when needed may play a crucial role in the complex machinery behind glucose homeostasis. We hypothesized that low-oxygenated islets, when not functionally challenged, do not rapidly cycle between activation and inactivation but are a stable population that remain low-oxygenated. As this was confirmed, we aimed to characterize these islets with regard to cell composition, vascular density, and endocrine cell proliferation. The 2-nitroimidazole low-oxygenation marker pimonidazole was administered as a single or repeated dose to Wistar Furth rats. The stability of oxygen status of islets was evaluated by immunohistochemistry as the number of islets with incorporated pimonidazole adducts after one or repeated pimonidazole injections. Adjacent sections were evaluated for islet cell composition, vascular density, and endocrine cell proliferation. Single and repeated pimonidazole injections over an 8-hour period yielded accumulation of pimonidazole adducts in the same islets. An average of 30% of all islets was in all cases positively stained for pimonidazole adducts. These islets showed a similar endocrine cell composition as other islets but had lower vascular density and β-cell proliferation. In conclusion, low-oxygenated islets were found to be a stable subpopulation of islets for at least 8 hours. Although they have previously been observed to be less functionally active, their islet cell composition was similar to that of other islets. Consistent with their lower oxygenation, they had fewer blood vessels than other islets. Notably, β-cell regeneration preferentially occurred in better-oxygenated islets.