The adult human brain represents only 2% of the body's total weight, however it is one of the most metabolically active organs in the mammalian body. Its high metabolic activity necessitates an efficacious waste clearance system. Besides the blood, there are two fluids closely linked to the brain and spinal cord drainage system: interstitial fluid (ISF) and cerebrospinal fluid (CSF). The aim of this review is to summarize the latest research clarifying the channels of metabolite removal by fluids from brain tissue, subarachnoid space (SAS) and brain dura (BD). Special attention is focused on lymphatic vascular structures in the brain dura, their localizations within the meninges, morphological properties and topographic anatomy. The review ends with an account of the consequences of brain lymphatic drainage failure. Knowledge of the physiological state of the clearance system is crucial in order to understand the changes related to impaired brain drainage.
The aim of this study was to observe the influence of electromagnetic radiation (EMR) on the structure and ultrastructure of the rat's liver. The pregnant rats used in the experiment were exposed to a pulsed microwave radiation (frequency of 2.45 GHz; mean power density of 2.8 mW/cm2) daily for 2 h, throughout their pregnancy. After delivery, the offspring was not exposed to EMR. Samples of the liver of 5-week-old offspring were subjected to histopathological evaluation. They were processed for light and transmission electron microscopy. Our results indicated that EMR did not cause pronounced changes in the structure of the liver of the investigated offspring. The size and shape of liver lobuli was preserved and the amount of connective tissue in the liver parenchyma did not increase. However, electron microscopy revealed changes in the shape and number of microvilli at the vascular pole of hepatocytes, and formation of vesicles of various shapes and sizes. The endothelial cells were swollen with larger fenestrations compared to the control group. The spaces of Disse were irregular and dilated. Even though these changes were only mild, further studies are needed to determine the effect of EMR and clarify its potential risk during pregnancy.
BACKGROUND: Nowadays, mobile devices that emit non-ionizing electromagnetic radiation (EMR) are predominantly used by juveniles and pubescents. The aim of the present study was to evaluate the effect of whole body pulsed EMR on the juvenile Wistar albino rat testis at a frequency of 2.45 GHz and mean power density of 2.8 mW/cm2. METHODS: The investigated animals (n=24) were divided into two control and two EMR groups (5 and 6 week old rats; 6 rats per group). Both EMR groups were irradiated continually for 3 weeks (2h/day) from postnatal days 14 and 21, respectively. RESULTS: EMR caused an irregular shape of seminiferous tubules with desquamated immature germ cells in the lumen, a large number of empty spaces along the seminiferous epithelium and dilated and congested blood vessels in the interstitial tissue of the testis. The cytoplasm of Sertoli cells showed strong vacuolization and damaged organelles, with the cytoplasm full of different heterophagic and lipid vacuoles or the cytoplasm of spermatocytes with swollen mitochondria in both irradiated groups. A significant increase in the total tubular area of seminiferous tubules was observed in both EMR groups compared with controls (P<0.001). A significant increase in the TUNEL-positive apoptotic nuclei (P<0.01) was accompanied by a significant rise in both Cu-Zn-SOD (P<0.01) and Mn-SOD (P<0.001) positive cells in the 6 week old experimental rats compared to control animals. CONCLUSION: Our results confirmed a harmful effect of non-ionizing radiation on the structure and ultrastructure of the juvenile rat testis.
