Secondary gliosarcoma: the clinicopathological features and the development of a patient-derived xenograft model of gliosarcoma.

BACKGROUND: Gliosarcoma (GSM) is a distinct and aggressive variant of glioblastoma multiforme (GBM) with worse prognosis and few treatment options. It is often managed with the same treatment modalities with temozolomide (TMZ) as in GBM. However, the therapeutic benefits on GSM from such treatment regimen is largely unknown. Patient-derived xenograft (PDX) models have been used widely to model tumor progression, and subsequently to validate biomarkers and inform potential therapeutic regimens. Here, we report for the first time the successful development of a PDX model of secondary GSM. METHODS: Tissue obtained from a tumor resection revealed a secondary GSM arising from GBM. The clinical, radiological, and histopathological records of the patient were retrospectively reviewed. Samples obtained from surgery were cultured ex vivo and/or implanted subcutaneously in immunocompromised mice. Histopathological features between the primary GBM, secondary GSM, and GSM PDX are compared. RESULTS: In explant culture, the cells displayed a spindle-shaped morphology under phase contrast microscopy, consistent with the sarcomatous component. GSM samples were subcutaneously engrafted into immunocompromised mice after single-cell suspension. Xenografts of serial passages showed enhanced growth rate with increased in vivo passage. We did not observe any histopathological differences between the secondary GSM and its serial in vivo passages of PDX tumors. CONCLUSIONS: Our PDX model for GSM retained the histopathological characteristics of the engrafted tumor from the patient. It may provide valuable information to facilitate molecular and histopathological modelling of GSM and be of significant implication in future research to establish precise cancer medicine for this highly malignant tumor.

Acute calcitriol treatment mitigates vitamin D deficiency-associated mortality after intracerebral haemorrhage.

OBJECTIVE: Vitamin D deficiency (VDD) is emerging as a predictor of poor prognosis in various neurological conditions, where clinical outcomes are often worse in stroke patients with VDD. This study aimed to provide experimental evidence on whether and how pre-existing VDD would affect survival and neurofunctional outcomes in intracerebral haemorrhage (ICH), and to evaluate whether acute vitamin D (VD) supplementation would improve post-stroke outcomes. METHODS: Experimental ICH models were induced in mice with and without VDD. Haematoma size was measured using T2*-weighted MRI and haemoglobin concentration. Post-ICH mortality, neurofunctional outcomes and the extent of blood-brain barrier (BBB) leakage were assessed to identify their correlations with VD status. Therapeutic benefits of acute VD administration were also evaluated. RESULTS: Mice with VDD exhibited significantly higher acute mortality rates and more severe motor deficits than mice without VDD post-ICH. Marked haematoma expansion and increased Evans blue extravasation were observed in VDD mice, suggesting that VDD was associated outcomes with increased BBB disruption. Acute treatment with a loading dose of VD (calcitriol) significantly improved outcomes in VDD mice. CONCLUSION: This study provides novel insights into the pathophysiological mechanisms at play in ICH concomitant with VDD and a scientific rationale for acute treatment with VD.

Risk of Seizure Aggravation after COVID-19 Vaccinations in Patients with Epilepsy.

Although Coronavirus disease 2019 (COVID-19) vaccinations are generally recommended for persons with epilepsy (PwE), a significant vaccination gap remains due to patient concerns over the risk of post-vaccination seizure aggravation (PVSA). In this single-centre, retrospective cohort study, we aimed to determine the early (7-day) and delayed (30-day) risk of PVSA, and to identify clinical predictors of PVSA among PwE. Adult epilepsy patients aged ≥18 years without a history of COVID-19 infection were recruited from a specialty epilepsy clinic in early 2022. Demographic, epilepsy characteristics, and vaccination data were extracted from a centralized electronic patient record. Seizure frequency before and after vaccination, vaccination-related adverse effects, and reasons for or against vaccination were obtained by a structured questionnaire. A total of 786 PwEs were included, of which 27.0% were drug-resistant. At the time of recruitment, 74.6% had at least 1 dose of the COVID-19 vaccine. Subjects with higher seizure frequency (p < 0.0005), on more anti-seizure medications (p = 0.004), or had drug-resistant epilepsy (p = 0.001) were less likely to be vaccinated. No significant increase in seizure frequency was observed in the early (7 days) and delayed phases (30 days) after vaccination in our cohort. On the contrary, there was an overall significant reduction in seizure frequency 30 days after vaccination (1.31 vs. 1.89, t = 3.436; p = 0.001). This difference was seen in both types of vaccine (BNT162b2 and CoronaVac) and drug-resistant epilepsy, but just missed significance for the second dose (1.13 vs. 1.87, t = 1.921; p = 0.055). Only 5.3% had PVSA after either dose of vaccine. Higher pre-vaccination seizure frequency of ≥1 per week (OR 3.01, 95% CI 1.05-8.62; p = 0.04) and drug-resistant status (OR 3.32, 95% CI 1.45-249 7.61; p = 0.005) were predictive of PVSA. Meanwhile, seizure freedom for 3 months before vaccination was independently associated with a lower risk of PVSA (OR 0.11, 95% CI 0.04-0.28; p < 0.0005). This may guide epilepsy treatment strategies to achieve better seizure control for at least 3 months prior to vaccination. As COVID-19 shifts to an endemic phase, this study provides important data demonstrating the overall safety of COVID-19 vaccinations among PwE. Identification of high-risk patients with subsequent individualized approaches in treatment and monitoring strategies may alleviate vaccination hesitancy among PwE.