Serotonin receptor HTR6-mediated mTORC1 signaling regulates dietary restriction-induced memory enhancement

Dietary restriction (DR; sometimes called calorie restriction) has profound beneficial effects on physiological, psychological, and behavioral outcomes in animals and in humans. We have explored the molecular mechanism of DR-induced memory enhancement and demonstrate that dietary tryptophan-a precursor amino acid for serotonin biosynthesis in the brain-and serotonin receptor 5-hydroxytryptamine receptor 6 (HTR6) are crucial in mediating this process. We show that HTR6 inactivation diminishes DR-induced neurological alterations, including reduced dendritic complexity, increased spine density, and enhanced long-term potentiation (LTP) in hippocampal neurons. Moreover, we find that HTR6-mediated mechanistic target of rapamycin complex 1 (mTORC1) signaling is involved in DR-induced memory improvement. Our results suggest that the HTR6-mediated mTORC1 pathway may function as a nutrient sensor in hippocampal neurons to couple memory performance to dietary intake

Liposome Consolidated with Cyclodextrin Provides Prolonged Drug Retention Resulting in Increased Drug Bioavailability in Brain

Although butylidenephthalide (BP) is an efficient anticancer drug, its poor bioavailability renders it ineffective for treating drug-resistant brain tumors. However, this problem is overcome through the use of noninvasive delivery systems, including intranasal administration. Herein, the bioavailability, drug stability, and encapsulation efficiency (EE, up to 95%) of BP were improved by using cyclodextrin-encapsulated BP in liposomal formulations (CDD1). The physical properties and EE of the CDD1 system were investigated via dynamic light scattering, transmission electron microscopy, UV–Vis spectroscopy, and nuclear magnetic resonance spectroscopy. The cytotoxicity was examined via MTT assay, and the cellular uptake was observed using fluorescence microscopy. The CDD1 system persisted for over 8 h in tumor cells, which was a considerable improvement in the retention of the BP-containing cyclodextrin or the BP-containing liposomes, thereby indicating a higher BP content in CDD1. Nanoscale CDD1 formulations were administered intranasally to nude mice that had been intracranially implanted with temozolomide-resistant glioblastoma multiforme cells, resulting in increased median survival time. Liquid chromatography–mass spectrometry revealed that drug biodistribution via intranasal delivery increased the accumulation of BP 10-fold compared to oral delivery methods. Therefore, BP/cyclodextrin/liposomal formulations have potential clinical applications for treating drug-resistant brain tumors

Segmental ureterectomy outcome of upper tract urothelial carcinoma in a high endemic area: A Taiwan nationwide collaborative study

Purpose:. According to the National Comprehensive Cancer Network guidelines, segmental ureterectomy (SU) of upper tract urothelial carcinoma (UTUC) is a considerable option for selected mid- and distal ureteral urothelial carcinoma (UC). As a UTUC endemic area, Taiwan lacks treatment outcome analysis of SU. Materials and methods:. This study retrospectively reviewed the treatment outcomes of SU for clinically localized UTUCs. Patients with biopsy or washing cytology-confirmed UTUCs who underwent open, laparoscopic, or robot-assisted management with curative intent were retrospectively reviewed for the eligibility of analysis. Cox regression was applied for univariable and multivariable analyses. Results:. A total of 161 patients who underwent SU were reviewed and analyzed. The median follow-up period was 44.5 (interquartile range, 21.6–84.9) months. After SU, 56/161 (34.8%) patients were free of UTUCs after the follow-up, 25/161 (15.5%) patients had local recurrence, and 35/161 (21.7%) had lymph node or distant metastasis. Surgical margin involvement was a risk factor associated with worse cancer-specific survival. Higher bladder recurrence and local recurrence rates were observed with concurrent bladder UC. Lymphovascular invasion and previous radical nephroureterectomy (RNU) for UC were related to higher local recurrence rates. Patients with pathological T3/T4 stage and end-stage renal disease tended to have higher metastasis rates. For the management of local recurrence, 19 patients received salvage RNU and 25 patients had adjuvant chemotherapy. However, 26/161 (16.1%) patients died of UTUCs and 2/161 (1.2%) patients died of surgery-related complications. Conclusion:. SU provides acceptable oncological outcomes if the surgeons select candidates carefully. SU is not recommended if the patient has T3 or higher stage or comorbidity of end-stage renal disease. Concurrent bladder UC is a risk factor for worse bladder recurrence-free survival and local recurrence-free survival. Lymphovascular invasion and previous RNU for UC were related to higher local recurrence rates. After SU, periodic follow-up is mandatory because the local recurrence rate is higher than radical surgery