Search

Cerebral sinus thrombosis, which constitutes a small percentage of all strokes, usually affects young individuals and can lead to venous stroke. Ischemic and hemorrhagic Stroke are associated with Spreading Depolarization (SD) waves in brain tissue, which propagate through the affected areas and cause a transient disruption of ionic homeostasis and neuronal function. This interaction highlights the complexity of the neurological consequences associated with SD. In this study, we investigated the occurrence of SDs following the occlusion of the superior sagittal sinus (SSS) in a gyrencephalic model, specifically swine. To instigate an occlusion, we surgically clipped the middle third of the SSS. The animals were grouped and monitored using one of three methods: electrocorticography (ECoG) alone, ECoG with intrinsic optical signal (IOS) imaging, or ECoG in conjunction with laser speckle contrast and oxygen imaging (LSCI). Post-mortem, the brains were analyzed using 2,3,5-triphenyl tetrazolium chloride (TTC) staining to check for venous infarction. Our results confirmed the spontaneous occurrence of SDs in the gyrencephalic swine brain after SSS occlusion, which was detectable via all monitoring methodologies. SD activity was most frequent in the first hour post-occlusion, subsequently diminishing. IOS imaging identified four unique hemodynamic responses, while TTC staining indicated no infarction. This research is the first to document SDs in the gyrencephalic swine brain following SSS occlusion, laying the groundwork for future investigations in both animal models and human clinical studies. [ABSTRACT FROM AUTHOR]

Objective: To evaluate clinical outcome of low (G1), intermediate (G2), and high‐(G3) grade mucoepidermoid carcinomas (MEC) of the parotid gland. Study Design: Retrospective chart review including 212 patients. Clinicopathological data was statistically analyzed regarding grading, overall survival (OS), disease‐free survival (DFS) and disease‐specific survival (DSS). Results: 105 (49.5%) G1, 73 (34.5%) G2, and 34 (16%) G3 MEC were included and 56 (26.4%) patients presented with neck node metastases. The risk of occult nodal metastases was significantly associated with grading and increased from 9.2% in G1 to 26.7% and 27.8% in G2 and G3 tumors, respectively (p = 0.008). Elective periparotid and cervical lymph node dissection was performed in 170 (80.2%) and 70 (33%) patients, respectively. All patients with positive periparotid nodes when subjected to an additional neck dissection had associated cervical neck node involvement (p < 0.001). Grading was an independent significant prognostic factor for OS (HR 4.05; 95%CI: 1.15–14.35; p = 0.030) and DSS (HR 17.35; 95%CI: 1.10–273.53; p = 0.043). In a subgroup analysis, elective neck dissection (END) was also significantly associated with a better DFS (p = 0.041) in neck node‐negative G1 MECs. Conclusion: The risk of occult nodal metastasis in intermediate‐grade MEC is as high as in high‐grade MEC and that END in G1 tumors is associated with a prolonged DFS. Additionally, periparotid node involvement seems to be a predictor for positive neck node involvement. This study presents some preliminary data to consider END in clinically neck node negative patients with parotid MEC; however, larger series are needed. Level of Evidence: 3 Laryngoscope, 133:124–132, 2023 [ABSTRACT FROM AUTHOR]

Introduction Parapharyngeal space tumors with complex anatomy and diverse histology have remained a challenging phenomenon for treating physicians. Objectives We have conducted a comprehensive web search on the PubMed, Web of Science, EMBASE, Cochrane Library, Biomedical Literature Database (CBM), and Clinicaltrials.gov databases to determine the factors that are associated with postoperative complications in parapharyngeal space tumors. Data Synthesis Two researchers reviewed all identified articles independently with a third reviewer for adjudication. Patient demographics and other clinicopathological characteristics were explored. The systematic review has identified 631 benign parapharyngeal space tumors with neurogenic and salivary tissue histology in 13 studies, with a mean age of 42.9 ± 7.76 years old and a median follow-up of 40.98 ± 19.1 months. Salivary gland (50.8%) and neurogenic (49.1%) tumors were the most common histological entities. Tumor size, location, histology, deep parotid lobe involvement, and proximity to great vessels or to the skull base were the deciding factors in selecting the surgical approach. The factors considered to select the surgical approach do not seem to have a correlation with the outcome in terms of neurological sequalae (p = 0.106). Tumors with neurogenic histology have significantly increased chances of developing neurological complication (OR 6.07; p = 0.001). Conclusion Neurologic complications are significantly associated with neurogenic benign tumors rather than surgical approach. [ABSTRACT FROM AUTHOR]

Application of crushed recycled glass in concrete materials can offer significant economical and environmental benefits provided that the alkali-silica reaction (ASR) of glass in concrete is properly controlled. Previous work on the use of glass sand in mortars shows that the reactivity of glass is influenced by its particle size as mortars containing finer glass sand show reduced ASR expansions. This may be counterintuitive since ASR is considered to be a surface reaction and should accelerate by increasing the surface area (i.e., reducing the size) of reactive aggregates. This paper presents a more in-depth investigation of the size-effect phenomena using scanning electron microscopy (SEM)/energy dispersive spectroscopy imaging of mortars containing different size glass particles. The SEM micrographs reveal that ASR does not occur at the glass-paste interface; rather, it occurs inside microcracks that exist inside glass particles which were generated during the glass bottle crushing operations. Larger size glass particles show larger and more active microcracks which render their high alkali-silica reactivity. At its interface with cement paste, glass shows evidence of pozzolanic reaction which leads to the formation of nonexpansive CSH. For particles smaller than #30 sieve (0.6 mm), the intraparticle ASR is minimal and only the interfacial pozzolanic reaction proceeds. This agrees well with the results of ASTM C1260 tests showing that mixed color glass aggregate smaller than #30 sieve does not produce deleterious ASR expansions in mortars even when no ASR suppressant (e.g., fly ash) is used. DOI: 10.1061/(ASCE)MT.1943-5533.0000126 CE Database subject headings: Recycling; Glass; Concrete; Aggregates; Durability; Cracking. Author keywords: Recycling; Glass; Concrete aggregates; Durability; Cracking.