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BACKGROUND: Hyperperfusion-induced cerebral hemorrhage (HICH) is a rare but severe complication in patients with carotid stenosis undergoing stent placement for which predictive models are lacking. Our objective was to develop a nomogram to predict such risk. METHODS: We included a total of 1226 patients with carotid stenosis who underwent stenting between June 2015 and December 2022 from three medical centers, divided into a development cohort of 883 patients and a validation cohort of 343 patients. The model used LASSO regression for feature optimization and multivariable logistic regression to develop the predictive model. Model accuracy was assessed via the receiver operating characteristic curve, with further evaluation of calibration and clinical utility through calibration curves and decision curve analysis (DCA). The model underwent internal validation using bootstrapping and external validation with the validation cohort. RESULTS: Older age (OR 1.07, p=0.005), higher degrees of carotid stenosis (OR 1.07, p=0.006), poor collateral circulation (OR 6.26, p<0.001), elevated preoperative triglyceride levels (OR 1.27, p=0.041) and neutrophil counts (OR 1.36, p<0.001) were identified as independent risk factors for HICH during hospitalization. The nomogram constructed based on these predictive factors demonstrated an area under the curve (AUC) of 0.817. The AUCs for internal and external validation were 0.809 and 0.783, respectively. Calibration curves indicated good model fit, and DCA confirmed substantial clinical net benefit in both cohorts. CONCLUSION: We developed and validated a nomogram to predict HICH in patients with carotid stenosis post-stenting, facilitating early identification and preventive intervention in high-risk individuals.
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The objective of this study is to verify the role of digital modified parotid tumor zoning method in modified parotid incision. The data of patients with parotid benign tumors from November 2021 to December 2023 were collected. Through the use of digital technology for soft tissue reconstruction, the parotid tumor was divided into four areas according to the digital image marker points. We designed the surgical incision according to the parotid gland division, found that it was feasible to guide the incision selection by division, and summarized the common incision and division corresponding, zone I was I and V-shaped incision, zone II was V incision, zone III was V and C- shaped incision, and zone IV was C- shaped incision. We conclude that the digital modified parotid gland zoning method can provide a better distinction in the surgical incision, and provide a better cosmetic incision and prognosis.
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OBJECTIVE: The reported date in the repeat surgical intervention for adolescent lumbar disc herniation (ALDH) after percutaneous endoscopic lumbar discectomy (PELD) was quite scarce. This study aims to introduce cases of repeat surgeries after PELD for ALDH and assess the incidence, chief causes, repeat surgery methods, and surgical outcomes of repeat surgeries after PELD for ALDH. METHODS: A retrospective multicenter observational study was conducted on patients undergoing repeat surgeries after PELD for ALDH at four tertiary referral hospitals from January 2014 through August 2022. The incidence of repeat surgeries, chief causes, strategies for repeat surgeries, and timing of repeat surgeries were recorded and analyzed. The clinical outcomes were evaluated by the Numeric Rating Scales (NRS) scores and the modified MacNab criteria. Statistical analyses were performed with the Wilcoxon signed-rank test. RESULTS: A total of 23 patients who underwent repeat surgeries after PELD for ALDH were included. The chief causes were re-herniation (homo-lateral re-herniation at the same level, new disc herniation of adjacent level). The repeat surgery methods were revision PELD, micro-endoscopic discectomy (MED), open discectomy and instrumented lumbar inter-body fusion. The NRS scores decreased significantly in follow-up evaluations and these scores demonstrated significant improvement at the last follow-up (p < 0.002). For the modified MacNab criteria, at the last follow-up, 18 patients (78.26%) had an excellent outcome, and the overall success rate was 86.95%. CONCLUSION: This study's data suggest that young patients who underwent repeat surgery improved significantly compared to baseline. The chief cause was re-herniation. Revision PELD was the main surgical procedure, which provides satisfactory clinical results in young patients who underwent repeat surgeries.
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Discotomia Percutânea , Endoscopia , Deslocamento do Disco Intervertebral , Vértebras Lombares , Reoperação , Humanos , Deslocamento do Disco Intervertebral/cirurgia , Adolescente , Estudos Retrospectivos , Masculino , Feminino , Vértebras Lombares/cirurgia , Discotomia Percutânea/métodos , Endoscopia/métodos , Adulto JovemRESUMO
In the development of single-molecule spectroscopy, the simultaneous detection of the excitation and emission spectra has been limited. The fluorescence excitation spectrum based on background-free signals is compatible with the fluorescence-emission-based detection of single molecules and can provide insight into the variations in the input energy of the different terminal emitters. Here, we implement single-molecule excitation-emission spectroscopy (SMEES) for photosystem I (PSI) via a cryogenic optical microscope. To this end, we extended our line-focus-based excitation-spectral microscope system to the cryogenic temperature-compatible version. PSI is one of the two photosystems embedded in the thylakoid membrane in oxygen-free photosynthetic organisms. PSI plays an essential role in electron transfer in the photosynthesis reaction. PSIs of many organisms contain a few red-shifted chlorophylls (Chls) with much lower excitation energies than ordinary antenna Chls. The fluorescence emission spectrum originates primarily from the red-shifted Chls, whereas the excitation spectrum is sensitive to the antenna Chls that are upstream of red-shifted Chls. Using SMEES, we obtained the inclining two-dimensional excitation-emission matrix (2D-EEM) of PSI particles isolated from a cyanobacterium, Thermosynechococcus vestitus (equivalent to elongatus), at about 80 K. Interestingly, by decomposing the inclining 2D-EEMs within time course observation, we found prominent variations in the excitation spectra of the red-shifted Chl pools with different emission wavelengths, strongly indicating the variable excitation energy transfer (EET) pathway from the antenna to the terminal emitting pools. SMEES helps us to directly gain information about the antenna system, which is fundamental to depicting the EET within pigment-protein complexes.
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Cianobactérias , Complexo de Proteína do Fotossistema I , Complexo de Proteína do Fotossistema I/química , Imagem Individual de Molécula , Espectrometria de Fluorescência , Cianobactérias/química , Temperatura , Clorofila/químicaRESUMO
This meta-analysis assesses the impact of Enhanced Recovery After Surgery (ERAS) protocols on surgical site wound infections (SSWIs) in urological procedures. Analysing data from 10 studies, our focus was on SSWI rates on the third and seventh postoperative days. The results reveal a significant reduction in SSWI rates for patients managed under ERAS protocols compared with traditional care. Notably, Figure 4 demonstrates a substantial decrease in SSWI on the third day (I2 = 93%; random: standardized mean difference [SMD]: -6.25, 95% confidence interval [CI]: -7.42 to -5.05, p < 0.01), and Figure 5 mirrors this trend on the seventh day (I2 = 95%; random: SMD: -4.72, 95% CI: -6.28 to -3.16, p < 0.01). These findings underscore the effectiveness of ERAS protocols in minimizing early postoperative wound infections, emphasizing their importance for broader implementation in urological surgeries.
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Recuperação Pós-Cirúrgica Melhorada , Infecção da Ferida Cirúrgica , Humanos , Tempo de Internação , Complicações Pós-Operatórias , Período Pós-Operatório , Infecção da Ferida Cirúrgica/prevenção & controleRESUMO
OBJECTIVES: This work aimed to analyse the risk factors for poor outcomes and mortality among patients with anterior large vessel occlusion (LVO) ischaemic stroke, despite successful recanalisation. SETTING AND PARTICIPANTS: This study conducted a secondary analysis among patients who underwent successful recanalisation in the CAPTURE trial. The trial took place between March 2018 and September 2020 at 21 sites in China. The CAPTURE trial enrolled patients who had an acute ischaemic stroke aged 18-80 years with LVO in anterior circulation. INTERVENTIONS: Thrombectomy was immediately performed using Neurohawk or the Solitaire FR after randomisation in CAPTURE trial. Rescue treatment was available for patients with severe residual stenosis caused by atherosclerosis. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary goal was to predict poor 90-day survival or mortality within 90 days post-thrombectomy. Univariate analysis, using the χ2 test or Fisher's exact test, was conducted for each selected factor. Subsequently, a multivariable analysis was performed on significant factors (p≤0.10) identified through univariate analysis using the backward selection logistic regression approach. RESULTS: Among the 207 recruited patients, 79 (38.2%) exhibited poor clinical outcomes, and 26 (12.6%) died within 90 days post-thrombectomy. Multivariate analysis revealed that the following factors were significantly associated with poor 90-day survival: age ≥67 years, internal carotid artery (ICA) occlusion (compared with middle cerebral artery (MCA) occlusion), initial National Institutes of Health Stroke Scale (NIHSS) score ≥17 and final modified Thrombolysis in Cerebral Infarction (mTICI) score 2b (compared with mTICI 3). Additionally, the following factors were significantly associated with mortality 90 days post-thrombectomy: initial NIHSS score ≥17, ICA occlusion (compared with MCA occlusion) and recanalisation with more than one pass. CONCLUSIONS: Age, NIHSS score, occlusion site, mTICI score and the number of passes can be independently used to predict poor 90-day survival or mortality within 90 days post-thrombectomy. TRIAL REGISTRATION NUMBER: NCT04995757.
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Arteriopatias Oclusivas , Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Lactente , Arteriopatias Oclusivas/etiologia , Isquemia Encefálica/cirurgia , Isquemia Encefálica/etiologia , Infarto da Artéria Cerebral Média/terapia , AVC Isquêmico/etiologia , Estudos Retrospectivos , Acidente Vascular Cerebral/cirurgia , Acidente Vascular Cerebral/etiologia , Trombectomia/efeitos adversos , Resultado do TratamentoRESUMO
Oocytes matured in vitro are useful for assisted human and farm animal reproduction. However, the quality of in vitro matured oocytes is usually lower than that of in vivo matured oocytes, possibly due to the absence of some important signal regulators in vitro. In this study, untargeted metabolomics was used to detect the changes in the metabolites in the follicular fluid (FF) during in vivo pig oocyte maturation and in the culture medium during in vitro maturation. Our results showed that the total metabolite changing profile of the in vivo FF was different from that of the in vitro maturation medium, but the levels of 23 differentially expressed metabolites (DEMs) changed by following the same trend during both in vivo and in vitro pig oocyte maturation. These 23 metabolites may be important regulators of porcine oocyte maturation. We found that progesterone and androstenedione, two factors in the ovarian steroidogenesis pathway enriched from the DEMs, were upregulated in the FF during in vivo pig oocyte maturation. The levels of these two factors were 31 and 20 fold, respectively, and they were higher in the FF than in the culture medium at the oocyte mature stage. The supplementation of progesterone and androstenedione during in vitro maturation significantly improved the pig oocyte maturation rate and subsequent embryo developmental competence. Our finding suggests that a metabolic abnormality during in vitro pig oocyte maturation affects the quality of the matured oocytes. This study identified some important metabolites that regulate oocyte maturation and their developmental potential, which will be helpful to improve assisted animal and human reproduction.
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The formation of amyloid filaments through templated seeding is believed to underlie the propagation of pathology in most human neurodegenerative diseases. A widely used model system to study this process is to seed amyloid filament formation in cultured cells using human brain extracts. Here, we report the electron cryo-microscopy structures of tau filaments from undifferentiated seeded SH-SY5Y cells that transiently expressed N-terminally HA-tagged 1N3R or 1N4R human tau, using brain extracts from individuals with Alzheimer's disease or corticobasal degeneration. Although the resulting filament structures differed from those of the brain seeds, some degrees of structural templating were observed. Studying templated seeding in cultured cells, and determining the structures of the resulting filaments, can thus provide insights into the cellular aspects underlying neurodegenerative diseases.
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Doença de Alzheimer , Degeneração Corticobasal , Neuroblastoma , Humanos , Doença de Alzheimer/patologia , Proteínas tau/metabolismo , Microscopia Crioeletrônica , Neuroblastoma/patologia , Encéfalo/metabolismo , AmiloideRESUMO
Background: Stent placement can be an effective treatment for patients with symptomatic intracranial stenosis (sICAS) and hemodynamic impairment (HI). However, the association between lesion length and the risk of recurrent cerebral ischemia (RCI) after stenting remains controversial. Exploring this association can help predict patients at higher risk for RCI and develop individualized follow-up schedules. Method: In this study, we provided a post-hoc analysis of a prospective, multicenter registry study on stenting for sICAS with HI in China. Demographics, vascular risk factors, clinical variables, lesions, and procedure-specific variables were recorded. RCI includes ischemic stroke and transient ischemic attack (TIA), from month 1 after stenting to the end of the follow-up period. Smoothing curve fitting and segmented Cox regression analysis were used to analyze the threshold effect between lesion length and RCI in the overall group and subgroups of the stent type. Results: The non-linear relationship between lesion length and RCI was observed in the overall population and subgroups; however, the non-linear relationship differed by subgroup of stent type. In the balloon-expandable stent (BES) subgroup, the risk of RCI increased 2.17-fold and 3.17-fold for each 1-mm increase in the lesion length when the lesion length was <7.70 mm and >9.00 mm, respectively. In the self-expanding stent (SES) subgroup, the risk of RCI increased 1.83-fold for each 1-mm increase in the lesion length when the length was <9.00 mm. Nevertheless, the risk of RCI did not increase with the length when the lesion length was >9.00mm. Conclusion: A non-linear relationship exists between lesion length and RCI after stenting for sICAS with HI. The lesion length increases the overall risk of RCI for BES and for SES when the length was <9.00 mm, while no significant relationship was found when the length was >9.00 mm for SES.
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The abnormal modification of histone is an important factor restricting development of porcine cloned embryos. Overexpression of histone H3K9me3 demethylase KDM4 family can effectively improve the developmental efficiency of cloned embryos. In order to explore the effects of overexpression of H3K9me3 demethylase on the development of porcine cloned embryos, KDM4A mRNA and KDM4D mRNA were injected respectively into porcine cloned embryos at the 1-cell stage and 2-cell stage to detect the blastocyst rate; 2-cell stage cloned embryos injected with KDM4A mRNA and embryo injection water (the control group) at the 1-cell stage were collected to detect the expression level of H3K9me3, and 4-cell stage cloned embryos were collected for single cell transcriptome sequencing, then the sequencing data was analyzed with KEGG and GO. The results showed that the blastocyst rate of porcine cloned embryos injected with KDM4A mRNA at 1-cell stage was significantly higher than that of the control group (25.32 ± 0.74% vs 14.78 ± 0.87%), while cloned embryos injected with KDM4D mRNA had a similar blastocyst rate with cloned embryos in control group (16.27 ± 0.77% vs 14.78 ± 0.87%). Porcine cloned embryos injected with KDM4A mRNA and KDM4D mRNA at 2-cell stage had a similar blastocyst rate with cloned embryos in control group (32.18 ± 1.67%, 30.04 ± 0.91% vs 31.22 ± 1.40%). The expression level of H3K9me3 in cloned embryos injected with KDM4A mRNA at 1-cell stage was lower than that in control group. There were 133 differentially expressed genes detected by transcriptome sequencing, including 52 up-regulated genes and 81 down-regulated genes. Pathways enriched by GO analyses were mainly related to protein localization. Pathways enriched by KEGG analyses were related to cellular senescence and acute myeloid leukemia. These results suggest that overexpression of histone H3K9me3 demethylase KDM4A can significantly improve the developmental efficiency of porcine cloned embryos.
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Histona Desmetilases , Histonas , Suínos/genética , Animais , Histona Desmetilases/metabolismo , Histona Desmetilases/farmacologia , Histonas/genética , Histonas/metabolismo , Técnicas de Transferência Nuclear , Desenvolvimento Embrionário/genética , Blastocisto/metabolismo , RNA Mensageiro/metabolismo , Clonagem de OrganismosRESUMO
A 21-nucleotide duplication in one allele of SNCA was identified in a previously described disease with abundant α-synuclein inclusions that we now call juvenile-onset synucleinopathy (JOS). This mutation translates into the insertion of MAAAEKT after residue 22 of α-synuclein, resulting in a protein of 147 amino acids. Both wild-type and mutant proteins were present in sarkosyl-insoluble material that was extracted from frontal cortex of the individual with JOS and examined by electron cryo-microscopy. The structures of JOS filaments, comprising either a single protofilament, or a pair of protofilaments, revealed a new α-synuclein fold that differs from the folds of Lewy body diseases and multiple system atrophy (MSA). The JOS fold consists of a compact core, the sequence of which (residues 36-100 of wild-type α-synuclein) is unaffected by the mutation, and two disconnected density islands (A and B) of mixed sequences. There is a non-proteinaceous cofactor bound between the core and island A. The JOS fold resembles the common substructure of MSA Type I and Type II dimeric filaments, with its core segment approximating the C-terminal body of MSA protofilaments B and its islands mimicking the N-terminal arm of MSA protofilaments A. The partial similarity of JOS and MSA folds extends to the locations of their cofactor-binding sites. In vitro assembly of recombinant wild-type α-synuclein, its insertion mutant and their mixture yielded structures that were distinct from those of JOS filaments. Our findings provide insight into a possible mechanism of JOS fibrillation in which mutant α-synuclein of 147 amino acids forms a nucleus with the JOS fold, around which wild-type and mutant proteins assemble during elongation.
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Atrofia de Múltiplos Sistemas , Sinucleinopatias , Humanos , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Sinucleinopatias/genética , Nigéria , Atrofia de Múltiplos Sistemas/genética , Atrofia de Múltiplos Sistemas/metabolismo , Mutação/genéticaRESUMO
Objective: Nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) is highly expressed in some tumors, including hepatocellular carcinoma (HCC). However, its clinical significance in HCC prognosis is still unclear. The aim of this study was to explore the expression and prognostic value of NUCKS1 in HCC. Materials and Methods: Quantitative real-time polymerase chain reaction was used to detect relative expression of NUCKS1 mRNA in HCC tissues and corresponding adjacent normal tissues. The relationship between NUCKS1 expression and clinical characteristics of patients was analyzed by χ2 test. Kaplan-Meier method and Cox regression analysis were applied to estimate prognostic value of NUCKS1 in HCC. Results: Compared with normal ones, the expression of NUCKS1 mRNA was significantly upregulated in HCC tissues (p < 0.001). Besides, NUCKS1 expression was closely associated with tumor differentiation, tumor node metastasis stage, vascular invasion, and metastasis (p < 0.05). Kaplan-Meier analysis revealed that overall survival was obviously longer in HCC patients with low expression of NUCKS1 than those with high NUCKS1 expression (log rank test, p = 0.001). NUCKS1 might be an independent prognostic factor for HCC patients (HR = 1.905, 95% CI = 1.106-3.283, p = 0.020). Conclusions: NUCKS1 may be correlated with the progression of HCC and serve as a potential predictive factor for the prognosis of this disease.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/análise , Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/patologia , Prognóstico , RNA MensageiroRESUMO
Introduction: On prostate biopsy, multiparametric magnetic resonance imaging (mpMRI) and the Prostate Health Index (PHI) have allowed prediction of clinically significant prostate cancer (csPCa). Methods: To predict the likelihood of csPCa, we created a nomogram based on a multivariate model that included PHI and mpMRI. We assessed 315 males who were scheduled for prostate biopsies. Results: We used the Prostate Imaging Reporting and Data System version 2 (PI-RADS V2) to assess mpMRI and optimize PHI testing prior to biopsy. Univariate analysis showed that csPCa may be identified by PHI with a cut-off value of 77.77, PHID with 2.36, and PI-RADS with 3 as the best threshold. Multivariable logistic models for predicting csPCa were developed using PI-RADS, free PSA (fPSA), PHI, and prostate volume. A multivariate model that included PI-RADS, fPSA, PHI, and prostate volume had the best accuracy (AUC: 0.882). Decision curve analysis (DCA), which was carried out to verify the nomogram's clinical applicability, showed an ideal advantage (13.35% higher than the model that include PI-RADS only). Discussion: In conclusion, the nomogram based on PHI and mpMRI is a valuable tool for predicting csPCa while avoiding unnecessary biopsy as much as possible.
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The quality of in vitro matured oocytes is inferior to that of in vivo matured oocytes, which translates to low developmental capacity of embryos derived from in vitro matured oocytes. The developmental potential of in vitro matured oocytes is usually impaired due to oxidative stress. Stromal cell-derived factor-l (SDF1) can reduce oxidative stress and inhibit apoptosis. The aim of this study was to investigate the effects of SDF1 supplementation during pig oocyte in vitro maturation (IVM) on subsequent embryo development, and to explore the acting mechanisms of SDF1 in pig oocytes. We found that the IVM medium containing 20 ng/mL SDF1 improved the maturation rate of pig oocytes, as well as the cleavage rate and blastocyst rate of embryos generated by somatic cell nuclear transfer, in vitro fertilization, and parthenogenesis. Supplementation of 20 ng/mL SDF1 during IVM decreased the ROS level, increased the mitochondrial membrane potential, and altered the expression of apoptosis-related genes in the pig oocytes. The porcine oocyte transcriptomic data showed that SDF1 addition during IVM altered the expression of genes enriched in the purine metabolism and TNF signaling pathways. SDF1 supplementation during pig oocyte IVM also upregulated the mRNA and protein levels of YY1 and TET1, two critical factors for oocyte development. In conclusion, supplementation of SDF1 during pig oocyte IVM reduces oxidative stress, changes expression of genes involved in regulating apoptosis and oocyte growth, and enhances the ability of in vitro matured pig oocytes to support subsequent embryo development. Our findings provide a theoretical basis and a new method for improving the developmental potential of pig in vitro matured oocytes.
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Desenvolvimento Embrionário , Técnicas de Maturação in Vitro de Oócitos , Suínos , Animais , Técnicas de Maturação in Vitro de Oócitos/métodos , Espécies Reativas de Oxigênio/farmacologia , Suplementos Nutricionais , RNA Mensageiro , Purinas/farmacologiaRESUMO
Fluorescence-spectral microscope observations of photosynthetic organisms at cryogenic temperatures have the ability to spectrally resolve the two photosystems (PSs) and thus provide a powerful tool to elucidate the functional analysis of photosynthesis in vivo. In the present study, a measurement channel of the fluorescence lifetime at 680 nm was added to the cryo-microscope system previously developed by the authors. This provides access to information on the functional state of the light-harvesting system in living cells during regulation by a mechanism called state transitions. The observations of state1-locked and state2-locked Chlamydomonas cells at 80 K enabled us to identify a component showing rapidly decaying fluorescence with a lifetime of ca. 3 ps and emitting at around 676 nm. The component was assigned to the light-harvesting complex II (LHCII) that is isolated from both PSs and in a quenched state, probably due to the formation of aggregates. Simultaneous spectral observations revealed the accumulation of this free LHCII in the photosystem I (PSI)-enriched region within each state2-locked cell. To the best of our knowledge, this is the first in-vivo observation which suggests the localization of the quenched LHCII aggregates.
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Chlamydomonas reinhardtii , Chlamydomonas , Complexo de Proteína do Fotossistema I/metabolismo , Chlamydomonas/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Chlamydomonas reinhardtii/metabolismo , Complexos de Proteínas Captadores de Luz/metabolismo , FotossínteseRESUMO
Parkinson's disease (PD) is the most common movement disorder, with resting tremor, rigidity, bradykinesia and postural instability being major symptoms1. Neuropathologically, it is characterized by the presence of abundant filamentous inclusions of α-synuclein in the form of Lewy bodies and Lewy neurites in some brain cells, including dopaminergic nerve cells of the substantia nigra2. PD is increasingly recognised as a multisystem disorder, with cognitive decline being one of its most common non-motor symptoms. Many patients with PD develop dementia more than 10 years after diagnosis3. PD dementia (PDD) is clinically and neuropathologically similar to dementia with Lewy bodies (DLB), which is diagnosed when cognitive impairment precedes parkinsonian motor signs or begins within one year from their onset4. In PDD, cognitive impairment develops in the setting of well-established PD. Besides PD and DLB, multiple system atrophy (MSA) is the third major synucleinopathy5. It is characterized by the presence of abundant filamentous α-synuclein inclusions in brain cells, especially oligodendrocytes (Papp-Lantos bodies). We previously reported the electron cryo-microscopy structures of two types of α-synuclein filament extracted from the brains of individuals with MSA6. Each filament type is made of two different protofilaments. Here we report that the cryo-electron microscopy structures of α-synuclein filaments from the brains of individuals with PD, PDD and DLB are made of a single protofilament (Lewy fold) that is markedly different from the protofilaments of MSA. These findings establish the existence of distinct molecular conformers of assembled α-synuclein in neurodegenerative disease.
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Química Encefálica , Encéfalo , Microscopia Crioeletrônica , Doença por Corpos de Lewy , alfa-Sinucleína , Humanos , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , alfa-Sinucleína/ultraestrutura , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/ultraestrutura , Doença por Corpos de Lewy/patologia , Doença de Parkinson/complicações , Doença de Parkinson/patologia , Demência/complicações , Demência/patologiaRESUMO
Photosynthetic organisms have developed a regulation mechanism called state transition (ST) to rapidly adjust the excitation balance between the two photosystems by light-harvesting complex II (LHCII) movement. Though many researchers have assumed coupling of the dynamic transformations of the thylakoid membrane with ST, evidence of that remains elusive. To clarify the above-mentioned coupling in a model organism Chlamydomonas, here we used two advanced microscope techniques, the excitation-spectral microscope (ESM) developed recently by us and the superresolution imaging based on structured-illumination microscopy (SIM). The ESM observation revealed ST-dependent spectral changes upon repeated ST inductions. Surprisingly, it clarified a less significant ST occurrence in the region surrounding the pyrenoid, which is a subcellular compartment specialized for the carbon-fixation reaction, than that in the other domains. Further, we found a species dependence of this phenomenon: 137c strain showed the significant intracellular inhomogeneity of ST occurrence, whereas 4A+ strain hardly did. On the other hand, the SIM observation resolved partially irreversible fine thylakoid transformations caused by the ST-inducing illumination. This fine, irreversible thylakoid transformation was also observed in the STT7 kinase-lacking mutant. This result revealed that the fine thylakoid transformation is not induced solely by the LHCII phosphorylation, suggesting the highly susceptible nature of the thylakoid ultrastructure to the photosynthetic light reactions.