Brain swelling, raised intracranial pressure and hypoxia-related brain injury
Helen Whitwell, Christopher Milroy, Daniel du Plessis in Forensic Neuropathology, 2021
The following features should be identified (Figure 12.15):Bright red to pink and not magenta cytoplasm.Pyknotic or disintegrating nuclei (pyknosis refers to nuclear shrinkage with dark intense staining and irregular profiles).Indistinct nucleoli and Nissl bodies.Prominent cell shrinkage.Red neuronal change should occur in groups of cells and not simply in rare, isolated cells interspersed with normal appearing neurons. It is acknowledged that metabolic differences between cells may allow some to develop these changes earlier than others and it is therefore possible that isolated cells surrounded by normal cells could represent cells possibly (not definitely) reflecting an early stage of injury in the form of dark neurons.
Tissue injury and repair
C. Simon Herrington in Muir's Textbook of Pathology, 2020
The microscopic changes that occur in necrosis reflect these key processes. Necrotic cells stain pink with routine (haematoxylin and eosin) stains, reflecting the presence of denatured proteins produced by the action of lysosomal enzymes. The cells lose definition under the microscope, reflecting the loss of organelles, again because of the effects of phospholipases and proteases. Nuclear changes are an important feature: there may be a loss of staining of the nucleus (karyolysis), shrinkage of the nucleus (pyknosis: more characteristically seen in apoptosis), and fragmentation of the nucleus (karyorrhexis). Eventually, the nucleus disappears completely. Calcium may be deposited in the dead cells, a process referred to as dystrophic calcification. It is important to recognize that the histological changes are only identifiable microscopically several hours after cell death in a surviving host.
A Histopathologic Classification of Chemical-Induced Injury of the Liver
Robert G. Meeks, Steadman D. Harrison, Richard J. Bull in Hepatotoxicology, 2020
Formation of acidophilic bodies or apoptosis is a different type of cell death which is differentiated clearly morphologically from that type of cell death associated with lytic necrosis (Figure 6) (Duvall and Wyllie, 1986). In this type of cell death the cytoplasm becomes dehydrated and more dense. This type of cell death is associated with nuclear pyknosis. Apoptosis is seen in a great variety of types of cell injury, particularly those of viral origin and also in atrophy as seen, for instance, in the myometrium after pregnancy. As far as chemical liver injury is concerned, apoptosis is seen in alcoholic liver injury and may also be found to some extent in injury by a great variety of toxic agents. Formation of apoptotic bodies is particularly striking in livers which are returning to normal size following lead-injection-induced hepatomegaly (Columbano et al., 1984).
Apoptosis is involved in paraoxon-induced histological changes in rat cerebellum
Published in Drug and Chemical Toxicology, 2022
Zohreh Zare, Sam Zarbakhsh, Shamim Mashhadban, Afshin Moradgholi, Moslem Mohammadi
In the current study, a decrease in the number of Purkinje cells (∼42%) and the thickness of both molecular and granular layers (∼30%) in animals intoxicated with a higher convulsive dose of paraoxon (1 mg/kg) at both time points. Pyknosis is the condensation of the chromatin in the nucleus of a cell undergoing apoptosis and often precedes nuclear fragmentation. It is important to note that pyknosis can also occur with necrotic cell death (Elmore 2007). Although we did not investigate the cause of pyknosis, pyknotic Purkinje cells were found in the cerebellum of animals treated with 1 mg/kg of paraoxon at both time points. No histological changes were observed in rats that received 0.3 and 0.7 mg/kg of paraoxon. In our previous studies, neuronal damage was observed in the CA1 region of the hippocampus following exposure to 1 mg/kg of paraoxon and in the prefrontal cortex and CA3 area post-exposure to 0.7 and 1 mg/kg of paraoxon (Zare et al. 2020a, 2020b). These results confirm that neuronal tissues have different vulnerabilities to OP-induced damage.
Antioxidant Effects of Resveratrol in Intervertebral Disk
Published in Journal of Investigative Surgery, 2022
Yachong Huo, Dalong Yang, Kaitao Lai, Ji Tu, Yibo Zhu, Wenyuan Ding, Sidong Yang
Apoptosis is characterized by the changes on cell morphology, nuclear pyknosis, mounts of apoptotic factors and reduction of cell connections.17 Oxidative stress and mitochondrial dysfunction both play a vital role in NPCs apoptosis and the regulation of apoptosis might be more benefit on NPCs survival.18 Increasing in vitro evidences have shown that hydrogen peroxide (H2O2), one of the apoptosis inducers, can cause significant NPCs apoptosis via oxidative stress by reducing cellular viability.19,20 Meanwhile, H2O2 can induce mitochondrial dysfunction with excessive ROS production, thus causing oxidative damage.21,22 Oxidative stress is closely related to mitochondrial function.23 Mitochondria are the organelles in the cell compartment that supply the energy needed to run cells. However, the damage of mitochondrial function would cause severe metabolic disorders, eventually causing excessive ROS production.24 Evidence has shown that NPCs apoptosis can be induced by the over-production of ROS through the mitochondrial apoptosis pathway.25 Thus, mitochondria are the target organelles that ROS damages and the major organelles that generate ROS.26,27
The adverse effects of carbofuran are efficiently counteracted by the supplementation of star anise (Illicium verum) in broiler chicks
Published in Toxin Reviews, 2021
Ashiq Ali, Aisha Khatoon, Zain Ul Abidin, Sajjad Hussain, Muhammad Kashif Saleemi, Rao Zahid Abbas, Muhammad Tariq Javed, Shafia Tehseen Gul, Farzana Rizvi
Renal parenchyma of control group was normal with normal tubular epithelial cells. Urinary spaces were normal with normal glomeruli throughout the parenchyma and both cortex and medullary regions were normal (Figure 2(D)). Similar pattern was also noticed in group D given star anise alone. However, in group B (CF 1), mild degree congestion was noticed and at few places, nuclei of tubular epithelial cells were pyknotic while in group C (CF 2) mild to moderate degree congestion was observed throughout the parenchyma with occlusion of fluid within lumen of renal tubules. At some places, pyknosis was noticed in nuclei of tubular epithelial cells indicating individual cell necrosis (Figure 2(E)). Pyknotic nuclei were also present at few places in the medullary region and at most of the places the urinary spaces were increased. Kidney of group E (CF 1 with star anise) showed congestion at only few places otherwise the parenchyma was normal in appearance. However, kidney of group F (CF 2 with star anise) showed mild congestion and urinary spaces were increased at some places. Pyknotic nuclei were also observed in tubular epithelial cells showing mild degree necrosis of individual cells (Figure 2(F)).