On Psychological Continuity and Dementia

This letter responds to the article “On the Authority of Advance Euthanasia Directives for People with Severe Dementia: Reflections on a Dutch Case,” by Henri Wijsbek and Thomas Nys, in the September-October 2022 issue of the Hastings Center Report.     

The Risk of Alzheimer's Disease After Acute Appendicitis With or Without Appendectomy

ObjectivePrevious epidemiologic studies have suggested an association between appendectomy and Parkinson's disease. The aim of the current study was to examine the risk of Alzheimer's disease (AD) and other types of dementia following appendicitis or appendectomy for appendicitis.DesignPopulation-based cohort study.Setting and participantsWe used claims data from the Taiwan National Health Insurance Research Database. Participants aged ≥45 years with acute appendicitis or who received appendectomy for appendicitis were enrolled and followed up for more than 15 years. Cases and controls underwent 1:1 matching by age, sex, index date, and dementia-related comorbidities.MethodsThe primary outcome was AD, and secondary outcomes included other dementia types. Adjusted hazard ratios (aHRs) were calculated, and a competing risk regression model was created. The E value for causality of evidence was calculated.ResultsPatients developing appendicitis (0.6% vs 0.1%, P = .005) and those receiving appendectomy for appendicitis (0.4% vs 0.1%, P = .003) had higher incidences of AD than the controls during the follow-up period. A Cox regression analysis with adjustment for potential confounders showed that patients with appendicitis [aHR 6.68, 95% confidence interval (CI) 1.84-24.48] and those receiving appendectomy for appendicitis (aHR 5.01, 95% CI 1.33-18.85) were more likely to develop AD than the controls. These 2 groups also had higher risks for unspecified dementia and all types of dementia but not for vascular dementia than the controls. The age at dementia diagnosis was 88.51 years in the controls; however, among people who developed dementia following appendicitis, the mean age at diagnosis was 70.18 years, and dementia occurred 5.84 years after appendicitis. The competing risk regression models and the E values support the study findings.Conclusions and implicationsAfter recovery from appendicitis, these patients should be followed up for signs of AD.     

Pharmacokinetics and Early Tumor Response to Conventional Transarterial Chemoembolization with Sorafenib and Doxorubicin in a VX2 Rabbit Tumor Model

PurposeTo investigate the pharmacokinetics (PK) and early effects of conventional transarterial chemoembolization (TACE) using sorafenib and doxorubicin on tumor necrosis, hypoxia markers, and angiogenesis in a rabbit VX2 liver tumor model.Materials and MethodsVX2 tumor-laden New Zealand White rabbits (N = 16) were divided into 2 groups: 1 group was treated with hepatic arterial administration of ethiodized oil and doxorubicin emulsion (DOX-TACE), and the other group was treated with ethiodized oil, sorafenib, and doxorubicin emulsion (SORA-DOX-TACE). Animals were killed within 3 days of the procedure. Levels of sorafenib and doxorubicin were measured in blood, tumor, and adjacent liver using mass spectrometry. Tumor necrosis was determined by histopathological examination. Intratumoral hypoxia-inducible factor (HIF) 1α, vascular endothelial growth factor (VEGF), and microvessel density (MVD) were determined by immunohistochemistry.ResultsThe median intratumoral concentration of sorafenib in the SORA-DOX-TACE group was 17.7 μg/mL (interquartile range [IQR], 7.42–33.5 μg/mL), and its maximal plasma concentration (C_max) was 0.164 μg/mL (IQR, 0.0798–0.528 μg/mL). The intratumoral concentration and C_max of doxorubicin were similar between the groups: 4.08 μg/mL (IQR, 3.18–4.79 μg/mL) and 0.677 μg/mL (IQR, 0.315–1.23 μg/mL), respectively, in the DOX-TACE group and 1.68 μg/mL (IQR, 0.795–4.08 μg/mL) and 0.298 μg/mL (IQR, 0.241–0.64 μg/mL), respectively, in the SORA-DOX-TACE group. HIF-1α expression was increased in the SORA-DOX-TACE group than in the DOX-TACE group. Tumor volume, tumor necrosis, VEGF expression, and MVD were similar between the 2 groups.ConclusionsThe addition of sorafenib to DOX-TACE delivered to VX2 liver tumors resulted in high intratumoral and low systemic concentrations of sorafenib without altering the PK of doxorubicin.     

补肾活血方对血管性痴呆大鼠海马神经细胞自噬的影响＊

目的 探究补肾活血方对血管性痴呆（Vascular Dementia， VD）大鼠模型自噬的影响。方法 52周龄SD雄性大鼠50只，随机分为假手术组（Sham组）、模型组（VD组）、模型+补肾活血方组（BSHX组）、模型+雷帕霉素组（Rap组）和模型+3-甲基腺嘌呤组（3-MA组），每组10只大鼠。除Sham组外其余各组采用两血管阻断法（2-VO）建立VD模型。BSHX组中药灌胃治疗28天；自噬干预组于造模前30 min侧脑室给药。运用Morris水迷宫测试各组大鼠的学习记忆能力；通过尼氏染色和透射电子显微镜（Transmission electron microscope，TEM）观察大鼠海马区病理形态及自噬变化；采用蛋白免疫印迹（Western blot）法和反转录实时荧光定量PCR（RT-qPCR）检测大鼠海马Beclin-1、P62以及微管相关蛋白1轻链3（LC3）蛋白及mRNA表达情况。结果 与VD组比较，BSHX组大鼠学习记忆能力显著提升（P<0.05），镜下观察BSHX组和3-MA组的细胞形态及数量均有改善，自噬小体鲜见，Beclin-1以及LC3蛋白和mRNA表达水平显著降低（P<0.05），P62蛋白和mRNA表达水平明显升高（P<0.05）结论 补肾活血方可以降低VD大鼠海马区Beclin-1和LC3蛋白及mRNA的表达，提高P62的表达，通过抑制自噬的发生，减轻对神经细胞的损伤，改善学习记忆能力。     

Interoception Primes Emotional Processing: Multimodal Evidence from Neurodegeneration

Recent frameworks in cognitive neuroscience and behavioral neurology underscore interoceptive priors as core modulators of negative emotions. However, the field lacks experimental designs manipulating the priming of emotions via interoception and exploring their multimodal signatures in neurodegenerative models. Here, we designed a novel task that involves interoceptive and control-exteroceptive priming conditions followed by post-interoception and post-exteroception facial emotion recognition (FER). We recruited 114 participants, including healthy controls (HCs) as well as patients with behavioral variant frontotemporal dementia (bvFTD), Parkinson''s disease (PD), and Alzheimer''s disease (AD). We measured online EEG modulations of the heart-evoked potential (HEP), and associations with both brain structural and resting-state functional connectivity patterns. Behaviorally, post-interoception negative FER was enhanced in HCs but selectively disrupted in bvFTD and PD, with AD presenting generalized disruptions across emotion types. Only bvFTD presented impaired interoceptive accuracy. Increased HEP modulations during post-interoception negative FER was observed in HCs and AD, but not in bvFTD or PD patients. Across all groups, post-interoception negative FER correlated with the volume of the insula and the ACC. Also, negative FER was associated with functional connectivity along the (a) salience network in the post-interoception condition, and along the (b) executive network in the post-exteroception condition. These patterns were selectively disrupted in bvFTD (a) and PD (b), respectively. Our approach underscores the multidimensional impact of interoception on emotion, while revealing a specific pathophysiological marker of bvFTD. These findings inform a promising theoretical and clinical agenda in the fields of nteroception, emotion, allostasis, and neurodegeneration.SIGNIFICANCE STATEMENT We examined whether and how emotions are primed by interoceptive states combining multimodal measures in healthy controls and neurodegenerative models. In controls, negative emotion recognition and ongoing HEP modulations were increased after interoception. These patterns were selectively disrupted in patients with atrophy across key interoceptive-emotional regions (e.g., the insula and the cingulate in frontotemporal dementia, frontostriatal networks in Parkinson''s disease), whereas persons with Alzheimer''s disease presented generalized emotional processing abnormalities with preserved interoceptive mechanisms. The integration of both domains was associated with the volume and connectivity (salience network) of canonical interoceptive-emotional hubs, critically involving the insula and the anterior cingulate. Our study reveals multimodal markers of interoceptive-emotional priming, laying the groundwork for new agendas in cognitive neuroscience and behavioral neurology.     

Neurovascular-modulation: A review of primary vascular responses to transcranial electrical stimulation as a mechanism of action

BackgroundThe ubiquitous vascular response to transcranial electrical stimulation (tES) has been attributed to the secondary effect of neuronal activity forming the classic neurovascular coupling. However, the current density delivered transcranially concentrates in: A) the cerebrospinal fluid of subarachnoid space where cerebral vasculature resides after reaching the dural and pial surfaces and B) across the blood-brain-barrier after reaching the brain parenchyma. Therefore, it is anticipated that tES has a primary vascular influence.ObjectivesFocused review of studies that demonstrated the direct vascular response to electrical stimulation and studies demonstrating evidence for tES-induced vascular effect in coupled neurovascular systems.ResultstES induces both primary and secondary vascular phenomena originating from four cellular elements; the first two mediating a primary vascular phenomenon mainly in the form of an immediate vasodilatory response and the latter two leading to secondary vascular effects and as parts of classic neurovascular coupling: 1) The perivascular nerves of more superficially located dural and pial arteries and medium-sized arterioles with multilayered smooth muscle cells; and 2) The endothelial lining of all vessels including microvasculature of blood-brain barrier; 3) Astrocytes; and 4) Neurons of neurovascular units.ConclusionA primary vascular effect of tES is highly suggested based on various preclinical and clinical studies. We explain how the nature of vascular response can depend on vessel anatomy (size) and physiology and be controlled by stimulation waveform. Further studies are warranted to investigate the mechanisms underlying the vascular response and its contribution to neural activity in both healthy brain and pathological conditions – recognizing many brain diseases are associated with alteration of cerebral hemodynamics and decoupling of neurovascular units.     

香萱益神方对血管性痴呆模型大鼠神经元凋亡机制研究

目的:探讨香萱益神方治疗血管性痴呆(VD)模型大鼠认知功能作用及其对神经元凋亡机制的研究。方法:两血管阻断法建立VD大鼠模型,给予中药方香萱益神方灌胃治疗6周,分别于造模后、中药喂养6周后进行Morris水迷宫行为学检测,测试大鼠认知行为能力改变,行为学测试结束后,检测VD模型大鼠海马中海马组织脑源性神经营养因子(BDNF)表达水平的变化。结果:香萱益神方治疗6周后,血管性痴呆大鼠模型学习记忆能力得到改善,上调脑内海马组织神经营养因子水平,海马神经元凋亡率下降。结论:香萱益神方是治疗血管性痴呆的有效方剂,可以有效改善VD大鼠模型认知行为功能的障碍情况,起到减少海马神经元细胞凋亡,诱导海马神经元细胞修复的作用。香萱益神方可能是通过激活BDNF相关通路,起到保护海马神经元的作用。