Chronic cerebral hypoperfusion accelerates Alzheimer's disease pathology with the change of mitochondrial fission and fusion proteins expression in a novel mouse model

Mitochondrial dynamically undergo massive fusion and fission events to continuously maintain their function in cells. Although an impaired balance of mitochondrial fission and fusion was reported in in-vitro and in-vivo Alzheimer's disease (AD) model, changes of mitochondrial fission and fusion proteins have not been reported in AD with chronic cerebral hypoperfusion (HP) as an etiological factor related to the development of elder AD. To clarify the impacts of HP on mitochondrial fission and fusion, related oxidative stress in the pathogenesis of AD, and protective effect of galantamine, the novel AD with HP mouse model (APP23 + HP) was applied in this project. Compared with APP23 mice, APP23 + HP mice greatly enhanced the number of Aβ oligomer-positive/phosphorylated tau (pTau) cells, the expression of mitochondrial fission proteins (Drp1 and Fis1), and decreased the expression of mitochondrial fusion proteins (Opa1 and Mfn1) in the cerebral cortex (CTX) and thalamus (TH) at 12 month (M) of age. Moreover, the expression of peroxidation products (4-HNE and 8-OHdG) showed a significant increase in CTX and TH of APP23 + HP mice at 12 M. However, above neuropathological characteristics were retrieved by galantamine (Gal) treatment, detected through immunohistochemical analyses. The present study demonstrates that cerebral HP shifted the balance in mitochondrial morphology from fusion to fission with increasing Aβ oligomer/pTau accumulations in APP23 mice, and such neuropathologic processes were strongly attenuated by Gal treatment.

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.

Anti-MuSK Antibody-positive Myasthenia Gravis Successfully Treated with Outpatient Periodic Weekly Blood Purification Therapy

A 37-year-old man with anti-muscle-specific tyrosine kinase (MuSK) antibody-positive myasthenia gravis (MG) presented with subacute progressive dysphagia and muscle weakness of the neck and bilateral upper extremities. Conventional immune-suppressive treatments and high-dose intravenous immunoglobulin were ineffective. He then displayed repeated exacerbations and remissions over the course of two years, despite two to four sessions of plasma exchange (PE) every two months. The patient was successfully treated with outpatient periodic weekly blood purification therapy with alternative PE and double-filtration plasmapheresis using an internal shunt. This case report suggests the benefits of blood purification therapy with an internal shunt against anti-MuSK antibody-positive MG.

Polypoidal Choroidal Vasculopathy Associated with Optic Disc Coloboma

Purpose

To report a case of polypoidal choroidal vasculopathy associated with optic disc coloboma.

Methods

Case report.

Results

A 50-year-old woman presented with optic disc coloboma and retinochoroidal coloboma associated with subretinal hemorrhage and serous retinal detachment (SRD) in her left eye. Optical coherence tomography (OCT) confirmed SRD at the macula and showed a sharply elevated retinal epithelial detachment at the choroidal excavation. OCT also revealed choroidal cavitation along the temporal side of the optic coloboma. Fluorescein angiography showed hyperfluorescent dye leakage and indocyanine green angiography revealed polypoidal lesions. We diagnosed polypoidal choroidal vasculopathy (PCV). PCV was located at the end of the choroidal cavitation. Her left eye was treated with an intraocular injection of the anti-vascular endothelial growth factor aflibercept (2 mg). Photodynamic therapy was performed using the standard protocol 1 week after the intravitreal application of aflibercept. One month after the combined treatment, OCT showed completely resolved SRD and her symptoms disappeared. Her best-corrected visual acuity remained stable and no recurrence was found during a 12-month follow-up period.

Conclusion

PCV associated with optic disc coloboma has not been previously reported. The morphological abnormality of choroidal cavitation and choroidal excavation connecting with optic disc coloboma may contribute to the development of PCV in this case.

Hypertrophic Pachymeningitis in Sjögren's Syndrome

Although central nervous system manifestations seem common in primary Sjögren's syndrome, hypertrophic pachymeningitis is rare. We herein describe a case of Sjögren's syndrome that was associated with hypertrophic pachymeningitis. Sjögren's syndrome should be considered as a cause of hypertrophic pachymeningitis.

Familial and sporadic chronic progressive degenerative parietal ataxia

BACKGROUND & OBJECTIVE

Parietal ataxia has been mainly reported as a consequence of acute ischemic stroke, while degenerative parietal ataxia has not been reported.

METHODS

We investigated clinical characteristics, neuroimaging data, and genetic analysis of patients with cerebellar ataxia plus parietal atrophy.

RESULTS

We identified seven patients, including five patients from two families, with chronic progressive cerebellar ataxia due to degenerative parietal atrophy but not stroke. Age at onset of ataxia was 57.6 ± 6.9 years. All patients showed chronic progressive cerebellar ataxia with severity of ataxic gait > limb ataxia > dysarthria. Patients showed no cognitive dysfunction, muscle weakness, or parkinsonism, and only two patients showed mild sensory disturbances. The seven patients showed lateralized limb ataxia with greater contralateral parietal lobe atrophy by magnetic resonance imaging, and hypoperfusion by single photon emission computed tomography, without any abnormal cerebellar pathology (i.e., crossed cerebellar diaschisis). Pathogenic mutations in the microtubule-associated protein tau gene were not found using two single nucleotide polymorphisms.

CONCLUSIONS

This is the first description showing unique clinical features of familial and sporadic chronic progressive degenerative parietal ataxia.

Different Associations of Plasma Biomarkers in Alzheimer's Disease, Mild Cognitive Impairment, Vascular Dementia, and Ischemic Stroke

Background and Purpose

Cognitive and cerebrovascular diseases are common in the elderly, but differences in the plasma levels and associations of plasma biomarkers in these diseases remain elusive.

Methods

The present study investigated differences in plasma fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)], adiponectin, reptin, plasma markers of inflammation [high-sensitivity C-reactive protein (hsCRP) and serum amyloid A (serum AA)], and plasma lipids [high-density lipoprotein and low-density lipoprotein (LDL)] in patients with Alzheimer's disease (AD) (n=266), mild cognitive impairment (MCI) (n=44), vascular dementia (VaD) (n=33), and ischemic stroke (IS) (n=200) in comparison to normal controls (n=130).

Results

The serological data showed that lower EPA and DHA levels and higher reptin and LDL levels were associated with AD and IS, the reptin/adiponectin ratio was strongly associated with IS, the hsCRP level was more strongly associated with VaD and IS, and the serum AA level was associated with all three cognitive diseases and IS.

Conclusions

This is the first report of differences in the expression levels of plasma biomarkers and peripheral arterial tonometry among AD, MCI, VaD, and IS patients and normal controls. These different associations indicate that diverse pathological mechanisms underlie these diseases.

Emergency Caesarean Section Saved Both an Anti-MuSK Antibody-positive Myasthenia Gravis Mother with Pregnancy-induced Hypertension and Her Premature Baby

We herein report the case of a 46-year-old pregnant woman with anti-muscle specific kinase (MuSK) antibody-positive myasthenia gravis (MG) who showed pregnancy-induced hypertension and developed respiratory failure at 30 weeks and 5 days of pregnancy, and who underwent an emergency caesarean section (CS). Her MG symptoms gradually improved in the subsequent weeks. The premature baby with positive MuSK antibodies was successfully delivered, but the male baby required temporary artificial ventilation. However, his condition also gradually improved over time. The present case suggests that an emergency CS could rescue both the mother, who was in critical condition, and the prematurely born baby, even when suffering from acute respiratory insufficiency.

Detecting spinal pyramidal tract of amyotrophic lateral sclerosis patients with diffusion tensor tractography

The objective of this study was to determine alteration of corticospinal tract in patients with amyotrophic lateral sclerosis (ALS) using diffusion tensor tractograhy (DTT) focusing on the cervical spinal cord (C5) and transcranial magnetic stimulation (TMS). We recruited 38 ALS, 6 spinal and bulbar muscular atrophy (SBMA), 7 spastic paraplegia (SP) patients, and 8 age-matched normal controls, and then ALS were divided into two subgroups according to their clinical type: 28 ALS-limb and 10 ALS-bulbar. DTT was performed using the diffusion tensor image (DTI) track module to reconstruct two fiber tracts via C5. The fractional anisotropy (FA) values of ALS-total and ALS-limb patients were significantly reduced compared with normal controls, and SBMA patients. On the other hand, the mean diffusivity (MD) values were not significantly different among normal controls and the three disease groups. The rate of disease progression (ΔFRS-R) of ALS patients was significantly correlated with FA values and central motor conduction time (CMCT). In conclusion, the present study demonstrated a significant reduction of FA values in ALS patients, and the ΔFRS-R of ALS patients showed distinct regressions with FA values and CMCT, suggesting that this DTT analysis could be useful for detecting disease progression of ALS patients.

Effects of short-term fasting on the Akt-mediated pathway involved in protein metabolism in chicken skeletal muscle

In the present study, we show that short-term (4 h) fasting significantly decreased the levels of protein synthesis-related factors such as the plasma insulin concentration, skeletal muscle pAkt, and pS6 levels in 2-wk-old chickens (P < 0.05). An intravenous injection of insulin significantly elevated the contents of pAkt and p-S6 in the skeletal muscle (P < 0.01). These findings suggest that decreasing the plasma insulin causes the downregulation of the Akt/S6 pathway in chicken skeletal muscle under short-term fasting conditions. However, protein synthesis was not significantly affected by short-term fasting. In addition, no significant change was observed in the levels of proteolysis-related factors such as plasma N^τ-methylhistidine, phosphorylated forkhead box class O, and muscle ring finger-1 during 4-h fasting, indicating that short-term fasting does not induce skeletal muscle proteolysis in chickens. Interestingly, atrogin-1 expression significantly increased after 2-h fasting (P < 0.05), and insulin injection significantly reversed the fasting-induced atrogin-1 expression in chicken skeletal muscle (P < 0.01). Collectively, these findings suggest that short-term fasting downregulates the insulin-stimulated Akt/S6 pathway but does not significantly affect protein synthesis and proteolysis in chicken skeletal muscle, and that atrogin-1 expression is upregulated in a FOXO1-independent manners.

Successful Delayed Aortic Surgery for a Patient with Ischemic Stroke Secondary to Aortic Dissection

The diagnosis of aortic dissection (AD) is sometimes difficult within the limited time window of recombinant tissue plasminogen activator (tPA) for ischemic stroke (IS). A 60-year-old man developed sudden left hemiparesis due to IS. During tPA infusion, his blood pressure dropped and consciousness declined. After transfer to our hospital, carotid duplex ultrasonography led to a diagnosis of AD. Emergency surgery was postponed because of the risk of hemorrhagic transformation. The patient successfully underwent aortic surgery on day 5 and was discharged with a remarkable improvement in his symptoms. Delayed surgery may avoid hemorrhagic transformation in patients with AD-induced IS who have received tPA.