122 research outputs found
Mutations, associated with early-onset Alzheimer’s disease, discovered in Asian countries
Crystal structure of Helicobacter pylori MinE, a cell division topological specificity factor
In Gram-negative bacteria, proper placement of the FtsZ ring, mediated by nucleoid occlusion and the activities of the dynamic oscillating Min proteins MinC, MinD and MinE, is required for correct positioning of the cell division septum. MinE is a topological specificity factor that counters the activity of MinCD division inhibitor at the mid-cell division site. Its structure consists of an anti-MinCD domain and a topology specificity domain (TSD). Previous NMR analysis of truncated Escherichia coli MinE showed that the TSD domain contains a long α-helix and two anti-parallel β-strands, which mediate formation of a homodimeric α/β structure. Here we report the crystal structure of full-length Helicobacter pylori MinE and redefine its TSD based on that structure. The N-terminal region of the TSD (residues 19–26), previously defined as part of the anti-MinCD domain, forms a β-strand (βA) and participates in TSD folding. In addition, H. pylori MinE forms a dimer through the interaction of anti-parallel βA-strands. Moreover, we observed serial dimer–dimer interactions within the crystal packing, resulting in the formation of a multimeric structure. We therefore redefine the functional domain of MinE and propose that a multimeric filamentous structure is formed through anti-parallel β-strand interactions
Follicular Thyroid Carcinoma Presenting as Bilateral Cheek Masses
Mandibular metastasis of thyroid carcinoma is extremely rare. We present the case of a 46-year-old woman who had bilateral huge cheek masses that had grown rapidly over several years. Intra-oral mucosal tissue biopsy and imaging work-up including computed tomography scan and magnetic resonance imaging were performed and the initial diagnosis was presumed to be central giant cell granuloma. Incidentally detected thyroid lesions were studied with ultra-sonography guided fine needle aspiration and diagnosed as simple benign nodules. Due to continuous oral bleeding and the locally destructive feature of the lesions, we decided to excise the mass surgically. To avoid functional deficit, a stepwise approach was performed: Firstly, the larger left mass was excised and the mandible was reconstructed with a fibular free flap. The final pathologic diagnosis was follicular thyroid cancer. Postoperative I-131 thyroid scan and whole body positron-emissions-tomography were performed. Right side mass was revealed as a thyroid malignancy. Multiple bony metastases were detected. Since further radioactive iodine therapy was required, additional total thyroidectomy and right side mandibulectomy with fibular free flap reconstruction was performed. The patient also underwent high dose radioactive iodine therapy and palliative extra-beam radiotherapy for the metastatic lumbar lesion. Follicular thyroid carcinoma should be considered as a differential diagnosis for mandibular mass lesions
TonEBP suppresses IL-10-mediated immunomodulation
TonEBP is a key transcriptional activator of M1 phenotype in macrophage, and its high expression is associated with many inflammatory diseases. During the progression of the inflammatory responses, the M1 to M2 phenotypic switch enables the dual role of macrophages in controlling the initiation and resolution of inflammation. Here we report that in human and mouse M1 macrophages TonEBP suppresses IL-10 expression and M2 phenotype. TonEBP knockdown promoted the transcription of the IL-10 gene by enhancing chromatin accessibility and Sp1 recruitment to its promoter. The enhanced expression of M2 genes by TonEBP knockdown was abrogated by antagonism of IL-10 by either neutralizing antibodies or siRNA-mediated silencing. In addition, pharmacological suppression of TonEBP leads to similar upregulation of IL-10 and M2 genes. Thus, TonEBP suppresses M2 phenotype via downregulation of the IL-10 in M1 macrophagesope
Novel PSEN1 G209A mutation in early-onset Alzheimer dementia supported by structural prediction
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the Creative Commons license, and indicate if changes were made.Abstract
Background
Three main genes are described as causative genes for early-onset Alzheimer dementia (EOAD): APP, PSEN1 and PSEN2. We describe a woman with EOAD had a novel PSEN1 mutation.
Case report
A 54-year-old right-handed woman presented 12-year history of progressive memory decline. She was clinically diagnosed as familial Alzheimer's disease due to a PSEN1 mutation.
One of two daughters also has the same mutation, G209A in the TM-IV of PS1 protein. Her mother had unspecified dementia that began at the age of 40s. PolyPhen2 and SIFT prediction suggested that G209A might be a damaging variant with high scores. 3D modeling revealed that G209A exchange could result significant changes in the PS1 protein.
Conclusion
We report a case of EOAD having probable novel PSEN1 (G209A) mutation verified with structural prediction
Incidentally Detected Situs Ambiguous in Adults
Situs ambiguous is rare congenital anomaly in adults. In 2 adult patients who admitted for different cardiac problems, situs ambiguous with polysplenia was detected. A 42-year-old male admitted for radio frequent catheter ablation of atrial fibrillation, and he had left-sided inferior vena cava (IVC), hepatic segment of IVC interruption with hemiazygos continuation, multiple spleens and intestinal malrotation. And in a 52-year-old female case who was hospitalized due to infective endocarditis after implanting pacemaker for sick sinus syndrome, multiple spleens, left-sided stomach, bilateral liver with midline gallbladder, and left-sided IVC were found. Those findings were consistent with situs ambiguous with polysplenia, but their features were distinctive
Factors Related to Regional Recurrence in Early Stage Squamous Cell Carcinoma of the Oral Tongue
ObjectivesThis study analyzed various clinical and histopathologic factors for patients with early stage squamous cell carcinoma (SCC) of the oral tongue to define a high risk group for regional recurrence and finally to find out the indication of elective neck dissection (END).MethodsRetrospective chart review was performed for 63 patients with T1-T2N0 SCC of the oral tongue who underwent partial glossectomy with/without END. Clinical and histopathologic factors assessed were age, gender, clinical T stage, tumor cell differentiation, depth of invasion, pathologic nodal status, and intrinsic muscle involvement, perineural invasion, lymphovascular emboli and resection margin involvement.ResultsFive year overall survival rate was 97.1% in stage I and 76.2% in stage II, and 5-yr disease free survival rate was 76.7% in stage I and 43.5% in stage II. Rates of occult nodal metastasis in stage I and II were 15.4% and 42.9%, respectively. Overall regional recurrence rate was 15.9%, which consisted of 10.2% in stage I and 35.7% in stage II. The success rate of salvage treatment was 100% in stage I and 40% in stage II. Higher T stage, higher histologic grade, depth of invasion ≥3 mm, presence of intrinsic muscle involvement were significantly related to regional recurrence (P=0.035, P=0.011, P=0.016, P=0.009, respectively). In stage I, the non-END group (n=36) showed 13.9% of regional recurrence rate, while END group (n=13) did not have any regional recurrence (P=0.198). Five year disease free survival rate of END group was significantly higher than non-END group (100% and 68.7%, respectively, P=0.045).ConclusionWe recommend to perform END in early stage SCC of the oral tongue if the primary tumor has T2 stage, and T1 stage with higher histologic grade, depth of invasion more than 3 mm, or presence of intrinsic muscle involvement
Decreased Exosomal Acetylcholinesterase Activity in the Plasma of Patients With Parkinson’s Disease
Exosomes, which are small extracellular vesicles produced from various cell types, contain a variety of molecular constituents, such as proteins, lipids, and RNA. Recently, exosomal biomarkers have been investigated to probe the understanding and diagnosis of neurodegenerative disorders. Previous reports have demonstrated increased exosomal α-synuclein (α-syn) in patients with Parkinson’s disease (PD) in comparison to healthy controls (HC). Interestingly, the cholinergic loss was revealed in the central and peripheral nervous systems in histopathology and molecular neuroimaging. Thereby, we simultaneously examined acetylcholinesterase (AChE) with α-syn as exosomal markers. Exosomes were isolated from the plasma of 34 FP-CIT PET proven patients with PD and 29 HC. Exosomal α-syn and AChE activity were quantified andthe relationship with clinical parameters was analyzed. Remarkably, exosomal AChE activity was significantly decreased in PD compared to HC (P = 0.002). Moreover, exosomal AChE activity in PD revealed a strong negative correlation with disease severity, including H&Y (P = 0.007) and UPDRS part III (P = 0.047) scores. By contrast, no significant difference in exosomal α-syn concentration was observed between groups. These results support the occurrence of cholinergic dysfunction in PD, and they could be implicated with disease progression, especially motor deficits. Exosomal AChE activity with advanced exosome isolation techniques may be a reliable biomarker for the early diagnosis and prognosis of PD
Plasma amyloid-β oligomerization assay as a pre-screening test for amyloid status
Objective
We assessed the performance of plasma amyloid oligomerization tendency (OAβ) as a marker for abnormal amyloid status. Additionally, we examined long-term storage effects on plasma OAβ.
Methods
We included 399 subjects regardless of clinical diagnosis from the Amsterdam Dementia Cohort and European Medical Information Framework for AD project (age, 63.8 ± 6.6; 44% female). Amyloid status was determined by visual read on positron emission tomography (PET; nabnormal = 206). Plasma OAβ was measured using the multimer detection system (MDS). Long-term storage effects on MDS-OAβ were assessed using general linear models. Associations between plasma MDS-OAβ and Aβ-PET status were assessed using logistic regression and receiver operating characteristics analyses. Correlations between plasma MDS-OAβ and CSF biomarker levels were evaluated using Pearson correlation analyses.
Results
MDS-OAβ was higher in individuals with abnormal amyloid, and it identified abnormal Aβ-PET with an area under the curve (AUC) of 0.74 (95% CI, 0.67–0.81), especially in samples with a storage duration < 4 years. Combining APOEe4 and age with plasma MDS-OAβ revealed an AUC of 81% for abnormal amyloid PET status (95% CI, 74–87%). Plasma MDS-OAβ correlated negatively with MMSE (r = − 0.29, p < .01) and CSF Aβ42 (r = − 0.20, p < 0.05) and positively with CSF Tau (r = 0.20, p = 0.01).
Conclusions
Plasma MDS-OAβ combined with APOEe4 and age accurately identifies brain amyloidosis in a large Aβ-confirmed population. Using plasma MDS-OAβ as a screener reduced the costs and number of PET scans needed to screen for amyloidosis, which is relevant for clinical trials. Additionally, plasma MDS-OAβ levels appeared affected by long-term storage duration, which could be of interest for others measuring plasma Aβ biomarkers.The Alzheimer Center Amsterdam is supported by Stichting Alzheimer Nederland and Stichting VUmc fonds. Research of the Alzheimer center Amsterdam is part of the neurodegeneration research program of Amsterdam Neuroscience. The clinical database structure was developed with funding from Stichting Dioraphte. The VUmc Biobank is supported by VUmc. The research leading to these results has received support from the Innovative Medicines Initiative Joint Undertaking under EMIF grant agreement no. 115372, resources of which are composed of financial contribution from the European Unions Seventh Framework Programme
(FP7/2007-2013) and EFPIA companies in kind contribution
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