Tooth loss as a risk factor for dementia: systematic review and meta-analysis of 21 observational studies.

BACKGROUND: Tooth loss is suggested to be associated with an increased risk of dementia in many studies. But the relationship between tooth loss and dementia is not yet fully understood. This systematic review and meta-analysis aimed to determine the relative effect of tooth loss on dementia risk. METHODS: An electronic search of PubMed, Scopus, Embase, and Web of Knowledge was conducted in March 2018 to identify relevant observational studies with the English language restriction. Studies were included if they assessed the relationship between tooth loss and risk of dementia. Study quality was detected by the modified Downs and Black scale. Odds risks (ORs) were pooled using a random-effects model in the crude model. RESULTS: The literature search initially yielded 1574 articles, and 21 observational studies published between 1994 and 2017 were finally included for the analyses. The crude results with random-effects model showed that patients with multiple tooth loss had higher incidence of dementia (OR 2.62, 95% CI 1.90-3.61, P < 0.001, I2 = 90.40%). The association remained noted when only adjusted results were pooled from 18 studies (OR 1.55, 95% CI 1.41-1.70, P = 0.13, I2 = 28.00%). Meta-regression analysis showed that study design explained about 16.52% of heterogeneity in the crude model. The overall quality rating scores of studies ranged from 11 to 16. CONCLUSIONS: Findings from this review evidenced that tooth loss is positively associated with an increased risk of dementia in adults. Future well-designed longitudinal researches examining the direct and indirect relationship between tooth loss and dementia risk are encouraged.

Comparison studies of ultrasound-guided botulinum toxin injection and balloon catheter dilatation in the treatment of neurogenic cricopharyngeal muscle dysfunction.

BACKGROUND: Cricopharyngeal muscle dysfunction (CPD) management has been challenging in clinical practice. OBJECTIVE: To compare the efficacy and safety of ultrasound-guided botulinum toxin injection and balloon catheter dilatation in treating CPD. METHODS: Forty patients with CPD were randomly divided into two groups, namely the botulinum toxin injection group (BTX group) and balloon dilatation group (BD group). Patients in the BTX group received a single ultrasound-guided injection of 50 units of botulinum toxin type A, while the BD group received dilatation therapy five times per week, consecutively for two weeks. Relative opening percentage of the upper esophageal sphincter (UES), the penetration-aspiration scale (PAS), and the Dysphagia Outcome Severity Scale (DOSS) were evaluated by a videofluoroscopic swallowing study (VFSS) at baseline, 1-month, and 3-months posttreatment. The Functional Oral Intake Scale (FOIS) and Standardized Swallowing Assessment (SSA) were also used to evaluate participants' swallowing function at baseline and the 1-week, 2-week, 1-month, and 3-month follow-ups. RESULTS: A generalized estimating equation (GEE) model revealed the significant main effect for time in UES, PAS, DOSS, FOIS, and SSA compared to baseline (P <0.05), while no group-by-time interactions (except for the PAS assessment) or main effect for treatment was detected among the above multiple variances. No systematic complications or severe adverse effects were noted. CONCLUSION: Both ultrasound-guided botulinum toxin type A injections and balloon dilatation therapy have been proven as safe and effective treatments for CPD patients. Future clinical trials with longer follow-up periods and more participants are warranted.

Neurotropin® alleviates hippocampal neuron damage through a HIF-1α/MAPK pathway.

AIMS: The main purpose was to verify the potent capacity of Neurotropin® against neuronal damage in hippocampus and to explore its underlying mechanisms. METHODS: HT22 cells were treated with 40 µmol/L Aß25-35 in the presence of various concentrations of Neurotropin® or in its absence. The cell viability was assessed with a CCK-8 assay, and flow cytometry was used to measure cell apoptosis, intracellular ROS levels, and mitochondrial membrane potential. Aß plaques were examined by Bielschowsky silver staining, and the activities of antioxidants were detected in hippocampus of APP/PS1 mice after Neurotropin® treatment. The expression of proteins, including HIF-1α, Bcl-2, Bax, and MAPKs signaling molecules was evaluated by Western blot. RESULTS: Neurotropin® significantly reversed the cell injury induced by Aß25-35 through increasing cell viability and mitochondrial membrane potential, decreasing intracellular ROS and cell apoptosis of HT22 cells (P<.05). Furthermore, Neurotropin® markedly reduced the formation of Aß plaques and upregulated the activities of antioxidants (P<.05). Additionally, the protein expression of HIF-1α, p-ERK1/2, p-JNK, and p-P38 was significantly inhibited in hippocampus of APP/PS1 mice. CONCLUSIONS: Neurotropin® exhibited a potent neuroprotective effect on inhibiting Aß-induced oxidative damage and alleviating Aß deposition in hippocampus via modulation of HIF-1α/MAPK signaling pathway.