Pharmacological Inhibition of Epidermal Growth Factor Receptor Prevents Intracranial Aneurysm Rupture by Reducing Endoplasmic Reticulum Stress

BACKGROUND

Multiple pathways and factors are involved in the rupture of intracranial aneurysms. The EGFR (epidermal growth factor receptor) has been shown to mediate inflammatory vascular diseases, including atherosclerosis and aortic aneurysm. However, the role of EGFR in mediating intracranial aneurysm rupture and its underlying mechanisms have yet to be determined. Emerging evidence indicates that endoplasmic reticulum (ER) stress might be the link between EGFR activation and the resultant inflammation. ER stress is strongly implicated in inflammation and apoptosis of vascular smooth muscle cells, both of which are key components of the pathophysiology of aneurysm rupture. Therefore, we hypothesized that EGFR activation promotes aneurysmal rupture by inducing ER stress.

METHODS

Using a preclinical mouse model of intracranial aneurysm, we examined the potential roles of EGFR and ER stress in developing aneurysmal rupture.

RESULTS

Pharmacological inhibition of EGFR markedly decreased the rupture rate of intracranial aneurysms without altering the formation rate. EGFR inhibition also significantly reduced the mRNA (messenger RNA) expression levels of ER-stress markers and inflammatory cytokines in cerebral arteries. Similarly, ER-stress inhibition also significantly decreased the rupture rate. In contrast, ER-stress induction nullified the protective effect of EGFR inhibition on aneurysm rupture.

CONCLUSIONS

Our data suggest that EGFR activation is an upstream event that contributes to aneurysm rupture via the induction of ER stress. Pharmacological inhibition of EGFR or downstream ER stress may be a promising therapeutic strategy for preventing aneurysm rupture and subarachnoid hemorrhage.

Hemophagocytic Lymphohistiocytosis: Management and Special Consideration in Human Immunodeficiency Virus Positive Patients with Immune Reconstitution Syndrome

The human body is capable of reacting to multiple aggressors by developing an inflammatory response with the secretion of inflammatory cytokines. The worrisome clinical manifestations occur when this inflammatory response is disproportionate. Hemophagocytic lymphohistiocytosis (HLH) is a rare and severe condition characterized by an overwhelming inflammatory response that may result in end-organ damage and might be fatal. Correspondingly, immune reconstitution inflammatory syndrome (IRIS) is another well-known disorder, seen commonly in human immunodeficiency virus (HIV)-infected patients after the commencement of highly active antiretroviral therapy (HAART). Both entities share a similar clinical presentation and a dismal prognosis. Due to widespread clinical manifestations and laboratory abnormalities, diagnosis is often missed at the time of presentation. There is little consensus on the treatment of secondary HLH, which is usually handled on a case-by-case basis. Rapid curbing of the widespread inflammatory response is the main goal of treatment. To the best of our knowledge, there is scarce literature available on the coexistence of HLH and IRIS; therefore, medical management in the co-occurrence of these two conditions needs to be further investigated.

A Fatal Case of Large Cell Neuroendocrine Lung Cancer Metastatic to the Brain: A Case Report

Large cell neuroendocrine carcinoma (LCNEC) is part of lung neuroendocrine tumors. LCNEC represents an extremely rare entity with aggressive behavior and poor prognosis. Primary surgery is the mainstream of treatment, although it is rarely amenable due to local or systemic tumor metastasis at the time of the diagnosis. We present a case report of a female patient diagnosed with large cell neuroendocrine lung cancer metastatic to the brain. Noting the low incidence of the disease, the lack of relevant clinical data has resulted in a challenge in diagnosis and management.

An Aggressive Case of Sinonasal Squamous Cell Carcinoma, Invasive to Bone, Arising Within Inverted Papilloma with Intracranial Extension: A Case Report

Sinonasal squamous cell carcinoma represents a rare and aggressive disease. Clinical presentation usually mimics other benign entities and consequently this malignancy is seldom diagnosed in early stages. Surgical management, although is standard of care, is rarely amenable due to the structures involved, usually intracranially. This article encompasses a case report of squamous cell carcinoma involving the ethmoidal, maxillary, and sphenoid sinuses invasive to bone and extending intracranially.

Bilateral Basal Ganglia Infarction After Intranasal Use of Cocaine: A Case Report

We present a case of a young man who developed bilateral basal ganglia infarct after intranasal use of cocaine. Cerebral ischemic infarcts are a known complication of cocaine use. This complication is rare and has been reported in the past with cocaine and concomitant use of other drugs such as heroin and amphetamines.

Cerebellar Cavernous Malformation (Cavernoma): A Case Report

Cavernous malformations are congenital or acquired vascular abnormalities. They are uncommon entities with an incidence of 0.5% of the general population and usually are unnoticed until a hemorrhagic event occurs. Cavernomas can be concurrently seen with developmental venous anomalies (DVAs) in 20% (range 20%-40%) of cases, in which case they are known as mixed vascular malformations. We report a case of a healthy young adult, who presented with acute onset of headache, dizziness, and nausea with intermittent episodes of vomiting for four days. Brain tomography imaging at presentation revealed likely multiple foci of intracranial hemorrhage; however, magnetic resonance imaging (MRI) showed findings suggestive of an underlying cavernoma that had bled, in addition to a coexisting DVA. The patient was discharged home with no deficits. Outpatient follow-up five months later revealed no symptoms or neurologic deficits.

Driving position field study, differences with the whiplash protocol and biomechanics experimental responses

Rear-impact collisions at low speed are a leading cause of economic costs among motor vehicle accidents. Recently, EuroNCAP has incorporated in its protocol the whiplash test, to reproduce a low-speed rear impact. This paper presents a field driving study to assess the potential differences between the EuroNCAP dummy tests and actual drivers in the field, focusing on occupant position and biomechanics experimental results. A total of 182 drivers were randomly selected in two geographical areas in Spain. The driving position of each driver was recorded with a focus on the most relevant measurements for rear impact. Statistical analysis was performed to obtain means, standard deviations and density functions to compare observational seating position with that of the EuroNCAP testing protocol. The observational data showed a similar seatback angle to that used in the EuroNCAP protocol (24° in front of 25° for the protocol), a greater distance between the head vertex and the top of the head restraint (53mm compared to 39.5mm), and less distance between the occipital bone of the head and the headrest (67.9 compared to 89.3mm). Based on these data, 4 dummy tests were conducted using the dummy BioRID IIg. The baseline test was designed to reproduce the dummy position according to EuroNCAP 3.0 whiplash protocol. Three different additional tests were defined to reproduce the actual observed driving position as well as to assess a "worst case" scenario in terms of reduced seatback angle. These variations in initial driver position, comparing the EuroNCAP protocol to the observational study results, were not observed to cause significant differences in the biomechanical values measured in the BioRID IIg, The T1 acceleration was reduced less than 8%, the NIC was increased about 8%, and the NKm presented a reduction of 20%. Reducing the seat angle was observed to be more harmful in terms of NIC.