Ilana Agranovich

Objective: to evaluate the dynamics of intestinal wall perfusion in adhesive acute intestinal obstruction and to determine the critical period of reversibility of ischemic changes. Material and methods. The study was performed in 50 rats in an acute experimental setting. Chronic adhesive disease was induced 30 days prior to the main experiment. Animals were divided into a control group (laparotomy without adhesions) and four experimental groups with adhesive disease: sham group (without obstruction), group A (strangulation for 1 hour), group B (24 hours), and group C (48 hours). Microcirculation was measured using non-contact laser Doppler flowmetry with vibration noise suppression; the M1 parameter (first spectral moment reflecting blood flow intensity, TPU) was evaluated. Statistical analysis was performed using STATISTICA 10.0 with parametric and non-parametric tests. Results. Peritoneal adhesions were found to reduce basal perfusion by 10.5% (0.95±0.05 vs 0.85±0.06 TPU; p=0.0256). Initiation of strangulation resulted in a sharp decrease in M1 by approximately three-fold within the first 10 minutes (to 0.34±0.09 TPU). Perfusion recovery after obstruction resolution depended on ischemia duration: at 1 hour, 68% of baseline level was recovered; at 24 hours, 24%; at 48 hours, no recovery was observed (p=0.567), indicating development of the irreversible "no-reflow" phenomenon. Conclusion. After strangulation, perfusion levels progressively decreased until the development of "biological zero" of microcirculation. The critical period of ischemia reversibility in adhesive strangulation is in the range of 24–48 hours.

Objective: to evaluate the dynamics of gastrointestinal wall perfusion in acute adhesive intestinal obstruction and to determine the critical period of reversibility of ischemic changes. Materials and Methods: The study was conducted on 50 rats in an acute experimental setting. Chronic adhesive disease was induced 30 days prior to the main experiment. Animals were divided into a control group (laparotomy without adhesions) and four experimental groups with adhesive disease: sham group (without obstruction), group A (strangulation for 1 hour), group B (strangulation for 24 hours), and group C (strangulation for 48 hours). Microcirculation was measured using non-contact laser Doppler flowmetry with vibration noise suppression; the M1 parameter (first spectral moment reflecting blood flow intensity, TPU) was evaluated. Statistical analysis was performed using STATISTICA 10.0 with parametric and non-parametric tests. Results: Peritoneal adhesions were found to reduce basal perfusion by 10.5% (0.95±0.05 vs 0.85±0.06 TPU; p=0.0256). The initiation of strangulation resulted in a sharp, approximately three-fold decrease in M1 within the first 10 minutes (to 0.34±0.09 TPU). Perfusion recovery after obstruction resolution depended on the duration of ischemia: after 1 hour, 68% of the baseline level was recovered; after 24 hours, 24%; and after 48 hours, no recovery was observed (p=0.567), indicating the development of the irreversible "no-reflow" phenomenon. Conclusion: Following strangulation, perfusion levels progressively decreased until the development of "biological zero" of microcirculation. The critical period of ischemia reversibility in adhesive strangulation is in the range of 24–48 hours.

Oxana Semyachkina-Glushkovskaya, Inna Blokhina, Nikita Navolokin, Arina Evsukova, Georgy Karandin, Alexander Khorovodov, Andrey Terskov, Ivan Fedosov, Alexander Dubrovsky, Maria Tzoy, Vasily Ageev, Ilana Agranovich, Valeria Telnova, Anna Tsven, Jürgen Kurths. J Acupunct Meridian Stud 2022;15:43-9. https://doi.org/10.51507/j.jams.2022.15.1.43

The recently rediscovered meningeal lymphatic system (MLS) opens new insight into pathways of brain clearing and drainage functions that play an important role in neurorehabilitation. The development of breakthrough strategies for augmentation of MLS might be a promising therapeutic target for preventing of neurological diseases. Here we demonstrate photostimulation (PS, 1268 nm) of clearing and drainage function of MLS in healthy male mice. We uncover PS‐mediated increase of the mesenteric lymphatic permeability to fluorescent macrophages via a decrease of expression of tight junction and transendothelial resistance. In sum, our results clearly show PS stimulation of meningeal clearing and drainage functions as well as effects of PS on permeability of the lymphatic endothelium to macrophages. These findings open new strategies for alternative nonpharmacological therapy of brain diseases via PS modulation of lymphatic mechanisms of the homeostasis of central nervous system.

There is a hypothesis that augmentation of the drainage and clearing function of the meningeal lymphatic vessels (MLVs) might be a promising therapeutic target for preventing neurological diseases. Here we investigate mechanisms of photobiomodulation (PBM, 1267 nm) of lymphatic drainage and clearance. Our results obtained at optical coherence tomography (OCT) give strong evidence that low PBM doses (5 and 10 J/cm²) stimulate drainage function of the lymphatic vessels via vasodilation (OCT data on the mesenteric lymphatics) and stimulation of lymphatic clearance (OCT data on clearance of gold nanorods from the brain) that was supported by confocal imaging of clearance of FITC-dextran from the cortex via MLVs. We assume that PBM-mediated relaxation of the lymphatic vessels can be possible mechanisms underlying increasing the permeability of the lymphatic endothelium that allows molecules transported by the lymphatic vessels and explain PBM stimulation of lymphatic drainage and clearance. These findings open new strategies for the stimulation of MLVs functions and non-pharmacological therapy of brain diseases.

In this paper, measurements of the optical properties (diffuse reflectance, total and collimated transmittance) of brain tissues in healthy rats and rats with C6-glioma were performed in the spectral range from 350 to 1800 nm. Using these measurements, characteristic tissue optical parameters, such as absorption coefficient, scattering coefficient, reduced scattering coefficient, and scattering anisotropy factor were reconstructed. It was obtained that the 10-day development of glioma led to increase of absorption coefficient, which was associated with the water content elevation in the tumor. However, further development of the tumor (formation of the necrotic core) led to decrease in the water content. The dependence of the scattering properties on the different stages of model glioma development was more complex. Light penetration depth into the healthy and tumor brain was evaluated.

Sex differences in stress-related diseases such as stroke and stomach cancer are well established, but the mechanisms underlying this phenomenon remain unknown. Despite the fact that sexual hormones play an important role in the high resistance of females to harmful effects of stress compared with males, the regulation of oxygenation status can be a potential factor, which might explain sex differences in stress-induced cerebrovascular catastrophes in newborn rats and in mutagens activation in adult rats with stomach cancer.