Morphological Changes in the Somatosensory Cortex of Guinea Pigs Following Simulation of the Abdominal Surgery Wound

The aim of research was to study the effect of the abdominal wall injuries and ascorbic acid (AA) on morphometric parameters of the somatosensory cortex.Material and methods. The density of the arrangement of neurons, sizes of nuclei and perikaryons of neurons, density and area of blood vessels in the somatosensory cortex were detected in guinea pigs after simulation of the abdominal wall injury. The process was accompanied by the parenteral administration of AA.Results. Simulation of the abdominal wall injury in guinea pigs resulted in a decreased thickness of the somatosensory cortex and a decreased density of neurons arrangement (on average by 32-37%). In 7 days after the operation, the exposed animals demonstrated a decreased density of blood vessels by 14–18%, the size of blood vessels also decreased by 27–46%; the fact evidencing a deterioration in the blood supply to the somatosensory cortex in the postoperative period. The effect of AA was mainly manifested in the increased size of the nuclei and perikaryons of neurons (by 20–40%); this evidencing activation of their metabolic activity. The most significant changes in the studied parameters were observed in the outer granular and, to a lesser extent, in the pyramidal and inner granular cytoarchitectonic layers.Conclusion. Experimental abdominal surgical interventions resulted in a decreased size and density of blood vessels in the somatosensory cortex. The results obtained can be used to develop methods of postoperative rehabilitation with the inclusion of drugs that improve blood supply and metabolism of the brain neurons. AA potentiates some of the effects of surgery on the somatosensory cortex; currently, there are no sufficient data to recommend it as a neuroprotective agent in the postoperative period.

Imaging of Intracellular and Plasma Membrane Pools of PI(4,5)P2 and PI4P in Human Platelets

Phosphoinositides (PIs) are phosphorylated membrane lipids that have a plethora of roles in the cell, including vesicle trafficking, signaling, and actin reorganization. The most abundant PIs in the cell are phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] and phosphatidylinositol-4-monophosphate (PI4P). The localization and roles of both PI(4,5)P2 and PI4P are well established, is the broadly accepted methodological approach for their immunocytochemical visualization in different cell compartments in several cell lines. However, not much is known about these PIs in platelets (PLTs), the smallest blood cells that detect vessel wall injury, activate, and stop the bleeding. Therefore, we sought to investigate the localization of PI(4,5)P2 and PI4P in resting and activated PLTs by antibody staining. Here, we show that the intracellular pools of PI(4,5)P2 and PI4P can be detected by the established staining protocol, and these pools can be modulated by inhibitors of OCRL phosphatase and PI4KIIIα kinase. However, although resting PLTs readily stain for the plasma membrane (PM) pools of PI(4,5)P2 and PI4P, just a few activated cells were stained with the established protocol. We show that optimized protocol allows for the visualization of PI(4,5)P2 and PI4P at PM in activated PLTs, which could also be modulated by OCRL and PI4KIIIα inhibitors. We conclude that PI(4,5)P2 and PI4P are more sensitive to lipid extraction by permeabilizing agents in activated than in resting human PLTs, which suggests their different roles during PLT activation.

Fluid-Structure Interaction in Coronary Stents: A Discrete Multiphysics Approach

Stenting is a common method for treating atherosclerosis. A metal or polymer stent is deployed to open the stenosed artery or vein. After the stent is deployed, the blood flow dynamics influence the mechanics by compressing and expanding the structure. If the stent does not respond properly to the resulting stress, vascular wall injury or re-stenosis can occur. In this work, a Discrete Multiphysics modelling approach is used to study the mechanical deformation of the coronary stent and its relationship with the blood flow dynamics. The major parameters responsible for deforming the stent are sorted in terms of dimensionless numbers and a relationship between the elastic forces in the stent and pressure forces in the fluid is established. The blood flow and the stiffness of the stent material contribute significantly to the stent deformation and affect its rate of deformation. The stress distribution in the stent is not uniform with the higher stresses occurring at the nodes of the structure. From the relationship (correlation) between the elastic force and the pressure force, depending on the type of material used for the stent, the model can be used to predict whether the stent is at risk of fracture or not after deployment.

Decreased Incidence of Rib Fractures in Pregnant Patients After Motor Vehicle Collisions

Background Rib fractures are common after motor vehicle collisions. The hormonal changes associated with pregnancy decrease the stiffness and increase the laxity of cartilage and tendons. The effect of these changes on injury mechanics is not completely understood. Objectives To compare the incidences of chest wall injury following blunt thoracic trauma between pregnant and nonpregnant women. Methods The authors conducted a retrospective review of female patients seen at a level I trauma center from 2009 to 2017 after a motor vehicle collision. Patient characteristics were compared to determine if pregnancy affected the incidence of chest wall injury. Statistics were calculated with SPSS version 24 and are presented as mean (SD) or median (interquartile range). Results In total, 1618 patients were identified. The incidence of rib/sternal fracture was significantly lower in pregnant patients (7.9% vs 15.2%, P = .047), but the incidence of intrathoracic injury was similar between the groups. Pregnant and nonpregnant patients with rib/sternal fractures had similar Injury Severity Score results (21 [13-27] vs 17 [11-22], P = .36), but pregnant patients without fractures had significantly lower scores (1 [0-5] vs 4 [1-9], P < .001). Conclusions Pregnant patients have a lower rate of rib fracture after a motor vehicle collision than nonpregnant patients. The difference in injury mechanics may be due to hormonal changes that increase elasticity and resistance to bony injury of the ribs. In pregnant trauma patients, intrathoracic injury without rib fracture should raise concerns about injury severity. A multicenter evaluation of these findings is needed.

Hyoid Elongation May Be a Rare Cause of Recurrent Ischemic Stroke in Youth-A Case Report and Literature Review

The investigation for etiology of ischemic stroke in young adults remains a diagnostic challenge. Hyoid bone–related carotid injury is a rare and under-recognized cause of ischemic stroke, without established guidelines. We describe a case of recurrent ischemic stroke in a young patient presumably attributed to an impingement of the carotid artery by an elongated hyoid bone, and present other cases reported in the literature. Based on the imaging study as well as the lack of other findings, we attributed recurrent neurovascular events to the repetitive mechanical stimulation by the elongated hyoid bone that caused a vessel wall injury with subsequent thrombus and embolus. Given repeated recurrence under antiplatelet treatment, anticoagulation was added. The following 2-year follow-up showed no new neurologic events or any other complaints. Among the young, a broad spectrum of possibilities should be considered and we call attention to this infrequent etiology of ischemic stroke.