Association of shift work with incident dementia: a community-based cohort study.

BACKGROUND: Some observational studies had found that shift work would increase risks of metabolic disorders, cancers, and cardiovascular diseases, but there was no homogeneous evidence of such an association between shift work and incident dementia. This study aimed to investigate whether shift work would increase the risk of dementia in a general population. METHODS: One hundred seventy thousand seven hundred twenty-two employed participants without cognitive impairment or dementia at baseline recruited between 2006 and 2010 were selected from the UK Biobank cohort study. Follow-up occurred through June 2021. Shift work status at baseline was self-reported by participants and they were categorized as non-shift workers or shift workers. Among shift workers, participants were further categorized as night shift workers or shift but non-night shift workers. The primary outcome was all-cause dementia in a time-to-event analysis, and the secondary outcomes were subtypes of dementia, including Alzheimer's disease, vascular dementia, and other types of dementia. RESULTS: In total, 716 dementia cases were observed among 170,722 participants over a median follow-up period of 12.4 years. Shift workers had an increased risk of all-cause dementia as compared with non-shift workers after multivariable adjustment (hazard ratio [HR], 1.30, 95% confidence interval [CI], 1.08-1.58); however, among shift workers, night shift work was not associated with the risk of dementia (HR, 1.04, 95% CI, 0.73-1.47). We found no significant interaction between shift work and genetic predisposition to dementia on the primary outcome (P for interaction = 0.77). CONCLUSIONS: Shift work at baseline was associated with an increased risk of all-cause dementia. Among shift workers, there was no significant association between night shift work and the risk of dementia. The increased incidence of dementia in shift workers did not differ between participants in different genetic risk strata for dementia.

DNA damage and repair in the visual center in the rhesus monkey model of glaucoma.

To study the DNA damage and repair methods of visual central neurons in a glaucoma model, a rhesus monkey chronic glaucoma model was established by laser induction, and changes in intraocular pressure (IOP), the optic cup fundus, the thickness of the retinal nerve fiber layer and the diameter of the optic nerve were evaluated. After a sufficient period of time, the model was euthanized, and the lateral geniculate body, primary visual cortex (V1 region) and secondary visual cortex (V2 region) were removed. Through immunofluorescence, ELISA and western blotting assays, the expressions of 8-hydroxyguanosine (8-OHG), a biomarker of oxidative stress, and γH2AX, a marker of DNA double-strand breaks, in the neurons of the LGN, V1 and V2 in the glaucoma model were higher than those of the control group (P < 0.05). The expression of key DNA repair proteins Ku80, Mre11, PCNA, DNA ligase IV and APE1 antibodies in the LGN, V1 and V2 of the glaucoma model was higher than that of the control group (P < 0.05), and in the positive TUNEL cells, the levels of cleaved caspase 3, Beclin 1 and LC3B-II/LC3B-I were significantly increased in the LGN of the glaucoma model (P < 0.05), but there was no significant positive expression in the V1 and V2 regions of the glaucoma model compared with the normal control group (P > 0.05). Transmission electron microscopy also showed that apoptotic bodies and autolysosomes (changes in neuronal apoptosis and autophagy activation) appeared in some neurons of the LGN in glaucoma, but there were no significant abnormal changes in the V1 and V2 regions of glaucoma or in any specimens in the normal group. In terms of neuron counting, the number of neurons in the LGN of the glaucoma model was lower than that in the normal control group (P < 0.05), but there was no significant difference in the number of neurons in the V1 and V2 regions between the two groups (P > 0.05). Similarly, the expression of glial cells in the LGN, V1 and V2 of the glaucoma model was higher than that in the control group (P < 0.05). Therefore, the results showed that DNA oxidative damage and various repair processes occurred in neurons of the LGN, V1 and V2 of the glaucoma model, and finally, LGN neurons died in the glaucoma model.

Transient ischemic attack presenting as recurrent migratory numbness by seconds: a rare case confirmed by transcranial Doppler micro-emboli monitoring.

BACKGROUND: Transient ischemic attack (TIA) is a brief episode of cerebral ischemia. However, if a symptom is not presented as drop attack or hemiplegia, and alarming to the patient and the physician, how short of a symptom duration would raise the concern of a physician for TIA? It will be more complicated if the location of the neurological deficit is vagrant. This report highlights a rare TIA case which presented a very short duration of migratory patchy distribution numbness. CASE PRESENTATION: A middle-aged gentleman was presented with recurrent patchy distribution numbness on the right side of the body for 2 months, with the episode lasting as short as about 10 s. The location of the numbness was erratic and migratory. Magnetic resonance angiography (MRA) revealed mild stenosis on the left middle cerebral artery (MCA). Transcranial Doppler (TCD) micro-emboli monitoring detected positive micro-emboli signals (MES), leading to the confirmation of a TIA diagnosis. After a standard dual antiplatelet treatment combined with enhanced lipid reduction therapy with statins, MES disappeared on dynamic TCD emboli monitoring, and no more episodes of TIA have been noticed on the follow-ups. CONCLUSION: TIA caused by micro-emboli can display as recurrent migratory neurological deficit within seconds. TCD micro-emboli monitoring is very helpful to differentiate this situation from TIA mimics with follow-ups, as well as to locate unstable plague.

Analysis of a method for establishing a model with more stable chronic glaucoma in rhesus monkeys.

In this study, we utilized yellow-wavelength laser treatment and measured aqueous outflow facility to establish a model for chronic glaucoma in rhesus monkeys. We then compared the effects of photocoagulation resulting from exposure to the yellow laser or to a green laser. Twelve rhesus monkeys were used to establish the model, and the yellow and green lasers were utilized for 360° photocoagulation in the anterior-chamber angles of the right eye in all subjects. After certain periods of time before and after the creation of the glaucoma model, the cornea, aqueous humor, optic cup, intraocular pressure (IOP), outflow facility, retinal nerve fiber layer (RNFL), and pathology of the trabecular meshwork were analyzed. Both the yellow and green lasers caused an increase in IOP compared with before photocoagulation (18.6 ± 2.6 mm Hg and 16.1 ± 1.8 mm Hg, respectively), with an average photocoagulation from the yellow and green lasers of 39.2 ± 7.9 mm Hg and 30.3 ± 4.7 mm Hg, respectively (P < 0.01). However, the success rate of a second photocoagulation treatment in the yellow laser group was significantly higher than in the green laser group (P < 0.05). After the increase in IOP, both groups exhibited an inflammatory response in the anterior segment, enlarged cupping, and a decrease in the average thickness of the RNFL. However, the yellow laser caused less corneal edema than the green laser (P < 0.05), and the outflow facility of the two groups (0.33 ± 0.09 and 0.30 ± 0.07 µl/min/mm Hg for the yellow and green lasers, respectively) showed different degrees of differences (0.05 ± 0.02 and 0.07 ± 0.02 µl/min/mm Hg for the yellow and green lasers, respectively) into the abnormal range after photocoagulation. Pathological examination revealed that the depth of destruction of the trabecular meshwork appeared to be deeper in the yellow laser group than in the green laser group. In conclusion, application of a yellow laser combined with measuring aqueous outflow facility produced a glaucoma model with a minor inflammatory response and few IOP fluctuations.

Prehypertension is associated with increased carotid atherosclerotic plaque in the community population of Southern China.

BACKGROUND: The proceeding of blood pressure (BP) from normal level to the hypertension has been found to be associated with increased cardiovascular events and multiple vascular risk factors. However, whether the process is associated with increased carotid atherosclerotic plaque per se or not is still unclear. METHODS: Nine hundred and forty-two participants aged from 46 to 75 were enrolled from community population in Southern China. Their metabolic risk factors, carotid intima-media thickness (cIMT) and atherosclerotic plaque formation were analyzed and stratified by different blood pressure levels according to JNC-7 or ESH/ESC-2007 classification. RESULTS: From low BP level to higher BP level, multiple metabolic risk factors increased linearly. Prehypertension in JNC-7 classification (or normal BP and high normal BP in ESH/ESC-2007 classification) was correlated with thicker cIMT and more plaque formation than normotension (or optimal BP) (p < 0.001). After adjusting multiple metabolic factors, the differences were still significant (p < 0.05). Furthermore, prehypertensive participants had a trend to be thicker carotid IMT (OR and its 95% CI: 1.65, 0.97-2.82, p = 0.067) and significantly higher carotid plaque occurrence (OR and its 95% CI: 2.36, 1.43-3.88, p = 0.001) than normotensive ones. However, there was no significant difference of cIMT and plaque formation between normal BP and high normal BP (p > 0.05). Plaque formation in prehypertension was as significant as that in hypertension. CONCLUSION: Prehypertension is associated with significantly increased carotid atherosclerotic plaque and is a primary stratify risk factor for carotid atherosclerosis which could cause ischemic stroke in middle-aged and elderly population in Southern China.

G protein-coupled receptor 158 modulates sensitivity to the sedative-hypnotic effect of ethanol in male mice.

BACKGROUND: Sensitivity to ethanol provides an index of the predisposition to recover from unconsciousness induced by a dose of ethanol. The role of the G protein-coupled receptor 158 (GPR158) in modulating sensitivity to the sedative-hypnotic effect of ethanol has not been investigated. METHODS: Loss of righting reflex (LORR) is a behavioral indicator of hypnosis in rodents. In this study, Gpr158-/- mice and wild-type (WT) littermates (n = 8/genotype) were tested using LORR induced by a dose of 3.5 g/kg ethanol, an open-field test (OFT), and a measure of blood ethanol concentration. The OFT was used to examine the role of GPR158 in the ethanol effect on motor activity in Gpr158-/- mice (n = 6/genotype). We also tested CamK2A-Cre;Gpr158fl/fl (n = 9) and Vgat-Cre;Gpr158fl/fl mice (n = 10) using the LORR test and OFT to compare with controls (n = 9 and 8, respectively). RESULTS: Gpr158 deficiency prolonged the LORR duration by 110.6%, t(14) = -5.241, p = 0.0001, without altering spontaneous activity, t(14) = -0.718, p = 0.485, or ethanol metabolism, F(1, 8) = 0.259, p = 0.625. Gpr158 knockout did not change the ethanol effect on locomotion, F(1, 10) = 0.262, p = 0.62. The LORR duration increased by 69% in the conditional knockouts of Gpr158 within calcium/calmodulin-dependent protein kinase II alpha-positive (CamK2A+ ) neurons, t(16) = -2.914, p = 0.01, and by 92% in the vesicular GABA transporter-positive (Vgat+ ) neurons, t(9.802) = -2.519, p = 0.023. Locomotion was not altered in Camk2A-Cre;Gpr158fl/fl , t(16) = 0.49, p = 0.631 or Vgat-Cre;Gpr158fl/fl mice, t(16) = 0.035, p = 0.972. CONCLUSIONS: This study reveals the key role of neuronal GPR158 in shaping sensitivity to the sedative-hypnotic effect of ethanol. These findings contribute to our understanding of the neurobiology of ethanol intoxication.

Association of earlier age at menopause with risk of incident dementia, brain structural indices and the potential mediators: a prospective community-based cohort study.

Background: To date, there is no homogeneous evidence of whether earlier age at menopause is associated with incident dementia. In addition, the underlying mechanism and driven mediators are largely unknown. We aimed to fill these knowledge gaps. Methods: This community-based cohort study included 154,549 postmenopausal women without dementia at enrolment (between 2006 and 2010) from the UK Biobank who were followed up until June 2021. We followed up until June 2021. Age at menopause was entered as a categorical variable (<40, 40-49, and ≥50 years) with ≥50 years taken as a reference. The primary outcome was all-cause dementia in a time-to-event analysis and the secondary outcomes included Alzheimer's disease, vascular dementia, and other types of dementia. In addition, we investigated the association between magnetic resonance (MR) brain structure indices with earlier menopause, and explored the potential underlying driven mediators on the relationship between earlier menopause and dementia. Findings: 2266 (1.47%) dementia cases were observed over a median follow-up period of 12.3 years. After adjusting for confounders, women with earlier menopause showed a higher risk of all-cause dementia compared with those ≥50 years (adjusted-HRs [95% CIs]: 1.21 [1.09-1.34] and 1.71 [1.38-2.11] in the 40-49 years and <40 years groups, respectively; P for trend <0.001). No significant interactions between earlier menopause and polygenic risk score, cardiometabolic factors, type of menopause, or hormone-replacement therapy strata were found. Earlier menopause was negatively associated with brain MR global and regional grey matter indices, and positively associated with white matter hyperintensity. The relationship between earlier menopause and dementia was partially mediated by menopause-related comorbidities including sleep disturbance, mental health disorder, frailty, chronic pain, and metabolic syndrome, with the proportion (95% CI) of mediation effect being 3.35% (2.18-5.40), 1.38% (1.05-3.20), 5.23% (3.12-7.83), 3.64% (2.88-5.62) and 3.01% (2.29-4.40), respectively. Multiple mediator analysis showed a combined effect being 13.21% (11.11-18.20). Interpretation: Earlier age at menopause was associated with risk of incident dementia and deteriorating brain health. Further studies are warranted to clarify the underlying mechanisms by which earlier age at menopause is linked to an increased risk of dementia, and to determine public health strategies to attenuate this association. Funding: National Natural Science Foundation of China, the Science and Technology Program of Guangzhou, the Key Area Research and Development Program of Guangdong Province, the China Postdoctoral Science Foundation, and the Guangdong Basic and Applied Basic Research Foundation.

Different types of milk consumption and the risk of dementia: Analysis from a large-scale cohort study.

BACKGROUND & AIMS: Previous studies have investigated whether milk consumption has a role in preventing the development of cognitive impairment, but the results were inconsistent. Importantly, most of them have disregarded the role of different types of milk. This study aimed to examine the associations between different types of milk consumption and the risk of dementia. METHODS: In this large-scale cohort study, participants without cognitive impairment at baseline were included from the UK Biobank. The type of milk mainly used was self-reported at baseline, including full-cream milk, skimmed-milk, soy milk, other milk, and no milk. The primary outcome was all-cause dementia. Secondary outcomes included Alzheimer's disease and vascular dementia. RESULTS: Of the 307,271 participants included in the study (mean age 56.3 [SD 8.1] years), 3789 (1.2%) incident all-cause dementia cases were observed over a median follow-up of 12.3 years. After adjustment for potential confounders, only soy milk consumers had a statistically significantly lower risk of all-cause dementia compared with no milk consumers (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.54 to 0.90). When compared with soy milk non-consumers consisting of full-cream milk, skimmed-milk, and other milk consumers, soy milk consumers still showed a lower risk of all-cause dementia (HR, 0.76; 95% CI, 0.63 to 0.92), and there was no significant interaction with genetic risk for dementia (P for interaction = 0.15). Soy milk consumers showed a lower risk of Alzheimer's disease (HR, 0.70; 95% CI, 0.51 to 0.94; P = 0.02), while the association was not significant for vascular dementia (HR, 0.72; 95% CI, 0.47 to 1.12; P = 0.14). CONCLUSIONS: The main consumption of soy milk was associated with a lower risk of dementia, particularly non-vascular dementia. Additional studies are needed to investigate how this association varies with the dose or frequency of the consumption of soy milk and to examine the generalizability of these findings in different populations.

Salmon Calcitonin Exerts an Antidepressant Effect by Activating Amylin Receptors.

Depressive disorder is defined as a psychiatric disease characterized by the core symptoms of anhedonia and learned helplessness. Currently, the treatment of depression still calls for medications with high effectiveness, rapid action, and few side effects, although many drugs, including fluoxetine and ketamine, have been approved for clinical usage by the Food and Drug Administration (FDA). In this study, we focused on calcitonin as an amylin receptor polypeptide, of which the antidepressant effect has not been reported, even if calcitonin gene-related peptides have been previously demonstrated to improve depressive-like behaviors in rodents. Here, the antidepressant potential of salmon calcitonin (sCT) was first evaluated in a chronic restraint stress (CRS) mouse model of depression. We observed that the immobility duration in CRS mice was significantly increased during the tail suspension test and forced swimming test. Furthermore, a single administration of sCT was found to successfully rescue depressive-like behaviors in CRS mice. Lastly, AC187 as a potent amylin receptor antagonist was applied to investigate the roles of amylin receptors in depression. We found that AC187 significantly eliminated the antidepressant effects of sCT. Taken together, our data revealed that sCT could ameliorate a depressive-like phenotype probably via the amylin signaling pathway. sCT should be considered as a potential therapeutic candidate for depressive disorder in the future.

Structural and Lipidomic Alterations of Striatal Myelin in 16p11.2 Deletion Mouse Model of Autism Spectrum Disorder.

Myelin abnormalities have been observed in autism spectrum disorder (ASD). In this study, we seek to discover myelin-related changes in the striatum, a key brain region responsible for core ASD features, using the 16p11.2 deletion (16p11.2±) mouse model of ASD. We found downregulated expression of multiple myelin genes and decreased myelin thickness in the striatum of 16p11.2± mice versus wild type controls. Moreover, given that myelin is the main reservoir of brain lipids and that increasing evidence has linked dysregulation of lipid metabolism to ASD, we performed lipidomic analysis and discovered decreased levels of certain species of sphingomyelin, hexosyl ceramide and their common precursor, ceramide, in 16p11.2± striatum, all of which are major myelin components. We further identified lack of ceramide synthase 2 as the possible reason behind the decrease in these lipid species. Taken together, our data suggest a role for myelin and myelin lipids in ASD development.

Elevated Intraocular Pressure Induces Amyloid-ß Deposition and Tauopathy in the Lateral Geniculate Nucleus in a Monkey Model of Glaucoma.

Purpose: Recent evidence has suggested a potential association between Alzheimer's disease (AD) and glaucoma and found significant deposition of amyloid-ß (Aß) and Tau protein in the retinas of glaucoma patients. However, no coherent finding has emerged regarding the AD-like changes in the central visual system (CVS). Studies confirming the presence of Aß and Tau neuropathology are warranted to identify the underlying mechanism that contributes to the visual impairment observed in glaucoma. Methods: A chronic glaucoma model was established in rhesus monkeys. The retina, optic nerve, CVS including the lateral geniculate nucleus (LGN) and primary visual cortex (V1), and cognitive areas including the hippocampus (Hpp) were evaluated. Aß 1-42 and phosphorylated-Tau (p-Tau) were tested in the aforementioned structure using immunohistochemistry, Western blotting and ELISA, and the neuritic plaques and argyrophilic structures/neurofilaments were observed using silver staining and transmission electron microscopy (TEM). Results: Immunohistochemistry revealed positive Aß and p-Tau labeling in the LGN. According to Western blotting assay and ELISA, Aß and p-Tau were present in the LGN. Aß also was expressed weakly in the primary visual cortex. In contrast, the hippocampus, which is the most severely affected region in AD, showed no positive labeling. Structurally, silver staining and TEM revealed neuritic plaques and argyrophilic structures/neurofibrillary tangles, in the LGN. Conclusions: For the first time to our knowledge, these data collectively establish the existence of hallmark AD-like pathologies in the glaucomatous LGN. Our results may provide new targets for developing research therapies that will enhance neuroprotection in glaucoma patients.

WITHDRAWN: Effects of atorvastatin treatment and withdrawal on blood brain barrier in focal cerebral ischemia-reperfusion injury.

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.