RESUMO
Unilateral spatial neglect (USN) results from impaired attentional networks and can affect various sensory modalities, such as visual and somatosensory. The rodent medial agranular cortex (AGm), located in the medial part of the forebrain from rostral to caudal direction, is considered a region associated with spatial attention. The AGm selectively receives multisensory input with the rostral AGm receiving somatosensory input and caudal part receiving visual input. Our previous study showed slower recovery from neglect with anterior AGm lesion using the somatosensory neglect assessment. Conversely, the functional differences in spatial attention across the entire AGm locations (anterior, intermediate, and posterior parts) are unknown. Here, we investigated the relationship between the severity of neglect and various locations across the entire AGm in a mouse stroke model using a newly developed program-based analysis method that does not require human intervention. Among various positions of the lesions, the recovery from USN during recovery periods (postoperative day; POD 10-18) tended to be slower in cases with more rostral lesions in the AGm (r = - 0.302; p = 0.028). Moreover, the total number of arm entries and maximum moving speed did not significantly differ between before and after AGm infarction. According to these results, the anterior lesions may slowly recover from USN-like behavior, and there may be a weak association between the AGm infarct site and recovery rate. In addition, all unilateral focal infarctions in the AGm induced USN-like behavior without motor deficits.
Assuntos
Modelos Animais de Doenças , Transtornos da Percepção , Animais , Transtornos da Percepção/fisiopatologia , Transtornos da Percepção/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Lateralidade Funcional/fisiologia , Percepção Espacial/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/complicações , Córtex Cerebral/fisiopatologiaRESUMO
Ovarian follicle development is an essential process for continuation of sexually reproductive animals, and is controlled by a wide variety of regulatory factors such as neuropeptides and peptide hormones in the endocrine, neuroendocrine, and nervous systems. Moreover, while some molecular mechanisms underlying follicle development are conserved, others vary among species. Consequently, follicle development processes are closely related to the evolution and diversity of species. Ciona intestinalis type A (Ciona rubusta) is a cosmopolitan species of ascidians, which are the closest relative of vertebrates. However, unlike vertebrates, ascidians are not endowed with the hypothalamus-pituitary-gonadal axis involving pituitary gonadotropins and sexual steroids. Combined with the phylogenetic position of ascidians as the closest relative of vertebrates, such morphological and endocrine features suggest that ascidians possess both common and species-specific regulatory mechanisms in follicle development. To date, several neuropeptides have been shown to participate in the growth of vitellogenic follicles, oocyte maturation of postvitellogenic follicles, and ovulation of fully mature follicles in a developmental stage-specific fashion. Furthermore, recent studies have shed light on the evolutionary processes of follicle development throughout chordates. In this review, we provide an overview of the neuropeptidergic molecular mechanism in the premature follicle growth, oocyte maturation, and ovulation in Ciona, and comparative views of the follicle development processes of mammals and teleosts.
Assuntos
Ciona intestinalis , Neuropeptídeos , Animais , Feminino , Filogenia , Ovulação , Folículo Ovariano , MamíferosRESUMO
The bacterium Leptothrix cholodnii generates cell chains encased in sheaths that are composed of woven nanofibrils. The nanofibrils are mainly composed of glycoconjugate repeats, and several glycosyltransferases (GTs) are required for its biosynthesis. However, only one GT (LthA) has been identified to date. In this study, we screened spontaneous variants of L. cholodnii SP6 to find those that form smooth colonies, which is one of the characteristics of sheathless variants. Genomic DNA sequencing of an isolated variant revealed an insertion in the locus Lcho_0972, which encodes a putative GT family 8 protein. We thus designated this protein LthB and characterized it using deletion mutants and antibodies. LthB localized adjacent to the cell envelope. ΔlthB cell chains were nanofibril free and thus sheathless, indicating that LthB is involved in nanofibril biosynthesis. Unlike the ΔlthA mutant and the wild-type strain, which often generate planktonic cells, most ΔlthB organisms presented as long cell chains under static conditions, resulting in deficient pellicle formation, which requires motile planktonic cells. These results imply that sheaths are not required for elongation of cell chains. Finally, calcium depletion, which induces cell chain breakage due to sheath loss, abrogated the expression of LthA, but not LthB, suggesting that these GTs cooperatively participate in glycoconjugate biosynthesis under different signaling controls. IMPORTANCE In recent years, the regulation of cell chain elongation of filamentous bacteria via extracellular signals has attracted attention as a potential strategy to prevent clogging of water distribution systems and filamentous bulking of activated sludge in industrial settings. However, a fundamental understanding of the ecology of filamentous bacteria remains elusive. Since sheath formation is associated with cell chain elongation in most of these bacteria, the molecular mechanisms underlying nanofibril sheath formation, including the intracellular signaling cascade in response to extracellular stimuli, must be elucidated. Here, we isolated a sheathless variant of L. cholodnii SP6 and thus identified a novel glycosyltransferase, LthB. Although mutants with deletions of lthA, encoding another GT, and lthB were both defective for nanofibril formation, they exhibited different phenotypes of cell chain elongation and pellicle formation. Moreover, LthA expression, but not LthB expression, was influenced by extracellular calcium, which is known to affect nanofibril formation, indicating the functional diversities of LthA and LthB. Such molecular insights are critical for a better understanding of ecology of filamentous bacteria, which, in turn, can be used to improve strategies to control filamentous bacteria in industrial facilities.
Assuntos
Glicosiltransferases , Leptothrix , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Leptothrix/fisiologia , Cálcio/metabolismo , Análise de Sequência de DNA , Glicoconjugados/metabolismoRESUMO
The bacterium Leptothrix cholodnii generates filaments encased in a sheath comprised of woven nanofibrils. In static liquid culture, L. cholodnii moves toward the air-liquid interface, where it forms porous pellicles. Observations of aggregation at the interface reveal that clusters consisting of only a few bacteria primarily grow by netting free cells. These growing clusters hierarchically enlarge through the random docking of other small clusters. We find that the bacteria swim using their polar flagellum toward the interface, where their sheath assists them in intertwining with others and thereby promotes the formation of small clusters. In contrast, sheathless hydrophobic mutant cells get stuck to the interface. We find that the nanofibril sheath is vital for robust pellicle formation as it lowers cell surface hydrophobicity by 60%, thereby reducing their adsorption and enabling cells to move toward and stick together at the air-liquid interface. IMPORTANCE Efficient and sustainable management of water resources is becoming a fundamental issue for supporting growing populations and for developing economic activity. Fundamental to this management is the treatment of wastewater. Microorganisms are the active component of activated sludge that is employed in the biodegradation process of many wastewater treatment facilities. However, uncontrolled growth of filamentous bacteria such as Sphaerotilus often results in filamentous bulking, lowering the efficiency of water treatment systems. To prevent this undesirable condition, strategies based on a fundamental understanding of the ecology of filamentous bacteria are required. Although the filamentous bacterium Leptothrix cholodnii, which is closely related to Sphaerotilus, is a minor inhabitant of activated sludge, its complete genome sequence is known, making gene manipulation relatively easy. Moreover, L. cholodnii generates porous pellicles under static conditions, which may be a characteristic of filamentous bulking. We show that both swimming motility and nanofibril-mediated air-liquid interface attachment are required for porous pellicle formation. These insights are critical for a better understanding of the characteristics of filamentous bulking and might improve strategies to control activated sludge.
Assuntos
Leptothrix , Esgotos/microbiologia , Porosidade , Águas Residuárias , Bactérias/metabolismoRESUMO
BACKGROUND: Cerebral blood flow (CBF) and dopamine transporter (DAT) images are clinically used for the differential diagnosis of parkinsonian disorders. OBJECTIVES: This study aimed to examine the correlation of CBF with striatal DAT in patients with Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) and evaluate the diagnostic power of DAT-correlated CBF in PD through machine learning with each imaging modality alone or in combination. METHODS: Fifty-eight patients with PD and 71 with APS (24 with multiple system atrophy, 21 with progressive supranuclear palsy, and 26 with corticobasal syndrome) underwent 123 I-IMP and 123 I-FP-CIT single-photon emission computed tomography. Multiple regression analyses for CBF and striatal DAT binding were conducted on each group. PD probability was predicted by machine learning and receiver operating characteristic curves. RESULTS: The PD group showed more affected striatal DAT binding positively correlated with the ipsilateral prefrontal perfusion and negatively with the bilateral cerebellar perfusion. In corticobasal syndrome, striatal DAT binding positively correlated with the ipsilateral prefrontal perfusion and negatively with the contralateral precentral perfusion. In Richardson's syndrome, striatal DAT binding positively correlated with perfusion in the ipsilateral precentral cortex and basal ganglia. Machine learning showed that the combination of CBF and DAT was better for delineating PD from APS (area under the curve [AUC] = 0.87) than either CBF (0.67) or DAT (0.50) alone. CONCLUSIONS: In PD and four-repeat tauopathy, prefrontal perfusion was related to ipsilateral nigrostriatal dopaminergic function. This dual-tracer frontostriatal relationship may be effectively used as a diagnostic tool for delineating PD from APS. © 2022 International Parkinson and Movement Disorder Society.
Assuntos
Doença de Parkinson , Transtornos Parkinsonianos , Circulação Cerebrovascular , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Transtornos Parkinsonianos/diagnóstico por imagem , Transtornos Parkinsonianos/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodosRESUMO
Extraneural recurrence of a medulloblastoma is rare with dismal prognosis. A 9-year-old girl with medulloblastoma was treated with gross total resection followed by a combination of chemotherapy and radiotherapy. Fourteen months after treatment completion, she developed multifocal bone metastases. Despite chemotherapy combined with irradiation, she died 18 months after recurrence due to progressive disease. Fluorescence in situ hybridization on formalin-fixed paraffin-embedded tissue sections revealed MYCN amplification and TP53 loss, consistent with the genetic alterations of a rapidly progressive subgroup of recurrent medulloblastomas. In clinical practice, dismal biologic features can be determined using fluorescence in situ hybridization in defective materials.
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Neoplasias Encefálicas , Neoplasias Cerebelares , Meduloblastoma , Neoplasias Encefálicas/patologia , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/terapia , Criança , Feminino , Humanos , Hibridização in Situ Fluorescente , Meduloblastoma/genética , Meduloblastoma/patologia , Meduloblastoma/terapia , Proteína Proto-Oncogênica N-Myc/genética , Proteína Supressora de Tumor p53/genéticaRESUMO
PURPOSE: We aimed to evaluate sleep-related hypoventilation in multiple system atrophy (MSA) using polysomnography (PSG) with transcutaneous partial pressure of carbon dioxide (PtcCO2) monitoring. METHODS: This prospective study included 34 patients with MSA. Motor and autonomic function, neuropsychological tests, PSG with PtcCO2 monitoring, and pulmonary function tests were performed. Sleep-related hypoventilation disorder (SRHD) was defined according to the International Classification of Sleep Disorders, third edition. RESULTS: Nine (27%) of the 34 patients met the diagnostic criteria of SRHD. Twenty-nine (85%) patients had sleep-related breathing disorders based on an Apnea-Hypopnea Index of ≥ 5/h. The patients with MSA and SRHD had a higher arousal index (p = 0.017) and obstructive apnea index (p = 0.041) than those without SRHD. There was no difference in the daytime partial pressure of carbon dioxide in arterial blood or respiratory function between MSA patients with and without SRHD. CONCLUSION: Sleep-related hypoventilation may occur in patients with MSA even with a normal daytime partial pressure of carbon dioxide. This can be noninvasively detected by PSG with PtcCO2 monitoring. SRBD and sleep-related hypoventilation are common among patients with MSA, and clinicians should take this into consideration while evaluating and treating this population.
Assuntos
Atrofia de Múltiplos Sistemas , Transtornos do Sono-Vigília , Humanos , Polissonografia , Hipoventilação/diagnóstico , Hipercapnia/diagnóstico , Dióxido de Carbono , Atrofia de Múltiplos Sistemas/diagnóstico , Estudos Prospectivos , Apneia , SonoRESUMO
BACKGROUND: Patients with diffuse idiopathic skeletal hyperostosis (DISH) are susceptible to spinal column injuries with neurological deterioration. Previous studies indicated that the prevalence of diabetes mellitus (DM) in patients with DISH was higher than that in patients without DISH. This study investigates the impact of DM on surgical outcomes for spinal fractures in patients with DISH. METHODS: We retrospectively evaluated 177 spinal fractures in patients with DISH (132 men and 45 women; mean age, 75 ± 10 years) who underwent surgery from a multicenter database. The subjects were classified into two groups according to the presence of DM. Perioperative complications, neurological status by Frankel grade, mortality rate, and status of surgical site infection (SSI) were compared between the two groups. RESULTS: DM was present in 28.2% (50/177) of the patients. The proportion of men was significantly higher in the DM group (DM group: 86.0% vs. non-DM group: 70.1%) (p = 0.03). The overall complication rate was 22.0% in the DM group and 19.7% in the non-DM group (p = 0.60). Poisson regression model revealed that SSI was significantly associated with DM (DM group: 10.0% vs. non-DM group: 2.4%, Relative risk: 4.5) (p = 0.048). Change in neurological status, mortality rate, instrumentation failure, and nonunion were similar between both groups. HbA1c and fasting blood glucose level (SSI group: 7.2% ± 1.2%, 201 ± 67 mg/dL vs. non-SSI group: 6.6% ± 1.1%, 167 ± 47 mg/dL) tended to be higher in patients with SSI; however, there was no significant difference. CONCLUSIONS: In spinal fracture in patients with DISH, although DM was an associated factor for SSI with a relative risk of 4.5, DM did not negatively impact neurological recovery. Perioperative glycemic control may be useful for preventing SSI because fasting blood glucose level was high in patients with SSI.
Assuntos
Diabetes Mellitus , Hiperostose Esquelética Difusa Idiopática , Fraturas da Coluna Vertebral , Idoso , Idoso de 80 Anos ou mais , Glicemia , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Hiperostose Esquelética Difusa Idiopática/complicações , Hiperostose Esquelética Difusa Idiopática/diagnóstico por imagem , Hiperostose Esquelética Difusa Idiopática/cirurgia , Masculino , Estudos Retrospectivos , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/cirurgia , Infecção da Ferida Cirúrgica/epidemiologiaRESUMO
Located in the critical 1p36 microdeletion region, the chromodomain helicase DNA-binding protein 5 (CHD5) gene encodes a subunit of the nucleosome remodeling and deacetylation (NuRD) complex required for neuronal development. Pathogenic variants in six of nine chromodomain (CHD) genes cause autosomal dominant neurodevelopmental disorders, while CHD5-related disorders are still unknown. Thanks to GeneMatcher and international collaborations, we assembled a cohort of 16 unrelated individuals harboring heterozygous CHD5 variants, all identified by exome sequencing. Twelve patients had de novo CHD5 variants, including ten missense and two splice site variants. Three familial cases had nonsense or missense variants segregating with speech delay, learning disabilities, and/or craniosynostosis. One patient carried a frameshift variant of unknown inheritance due to unavailability of the father. The most common clinical features included language deficits (81%), behavioral symptoms (69%), intellectual disability (64%), epilepsy (62%), and motor delay (56%). Epilepsy types were variable, with West syndrome observed in three patients, generalized tonic-clonic seizures in two, and other subtypes observed in one individual each. Our findings suggest that, in line with other CHD-related disorders, heterozygous CHD5 variants are associated with a variable neurodevelopmental syndrome that includes intellectual disability with speech delay, epilepsy, and behavioral problems as main features.
Assuntos
DNA Helicases/genética , Deficiência Intelectual/genética , Mutação de Sentido Incorreto , Proteínas do Tecido Nervoso/genética , Transtornos do Neurodesenvolvimento/genética , Adolescente , Domínio Catalítico , Criança , Pré-Escolar , Estudos de Coortes , Epilepsia/genética , Feminino , Genes Dominantes , Humanos , Deficiência Intelectual/fisiopatologia , Masculino , Transtornos do Neurodesenvolvimento/fisiopatologia , Linhagem , Adulto JovemRESUMO
Corpus callosum anomalies (CCA) is a common congenital brain anomaly with various etiologies. Although one of the most important etiologies is genetic factors, the genetic background of CCA is heterogenous and diverse types of variants are likely to be causative. In this study, we analyzed 16 Japanese patients with corpus callosum anomalies to delineate clinical features and the genetic background of CCAs. We observed the common phenotypes accompanied by CCAs: intellectual disability (100%), motor developmental delay (93.8%), seizures (60%), and facial dysmorphisms (50%). Brain magnetic resonance imaging showed colpocephaly (enlarged posterior horn of the lateral ventricles, 84.6%) and enlarged supracerebellar cistern (41.7%). Whole exome sequencing revealed genetic alterations in 9 of the 16 patients (56.3%), including 8 de novo alterations (2 copy number variants and variants in ARID1B, CDK8, HIVEP2, and TCF4) and a recessive variant of TBCK. De novo ARID1B variants were identified in three unrelated individuals, suggesting that ARID1B variants are major genetic causes of CCAs. A de novo TCF4 variant and somatic mosaic deletion at 18q21.31-qter encompassing TCF4 suggest an association of TCF4 abnormalities with CCAs. This study, which analyzes CCA patients usung whole exome sequencing, demonstrates that comprehensive genetic analysis would be useful for investigating various causal variants of CCAs.
Assuntos
Agenesia do Corpo Caloso/diagnóstico , Encéfalo/diagnóstico por imagem , Anormalidades Congênitas/diagnóstico , Malformações do Sistema Nervoso/diagnóstico , Adolescente , Adulto , Agenesia do Corpo Caloso/complicações , Agenesia do Corpo Caloso/genética , Agenesia do Corpo Caloso/patologia , Encéfalo/patologia , Encefalopatias/complicações , Encefalopatias/diagnóstico , Encefalopatias/genética , Encefalopatias/patologia , Criança , Pré-Escolar , Anormalidades Congênitas/genética , Anormalidades Congênitas/patologia , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/patologia , Variações do Número de Cópias de DNA/genética , Feminino , Humanos , Deficiência Intelectual/complicações , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Japão , Ventrículos Laterais/anormalidades , Ventrículos Laterais/patologia , Masculino , Transtornos Motores/complicações , Transtornos Motores/diagnóstico , Transtornos Motores/genética , Transtornos Motores/patologia , Mutação/genética , Malformações do Sistema Nervoso/complicações , Malformações do Sistema Nervoso/genética , Malformações do Sistema Nervoso/patologia , Fenótipo , Sequenciamento do Exoma , Adulto JovemRESUMO
Kinesin super family (KIF) genes encode motor kinesins, a family of evolutionary conserved proteins, involved in intracellular trafficking of various cargoes. These proteins are critical for various physiological processes including neuron function and survival, ciliary function and ciliogenesis, and cell-cycle progression. Recent evidence suggests that alterations in motor kinesin genes can lead to a variety of human diseases, including monogenic disorders. Neuropathies, impaired higher brain functions, structural brain abnormalities and multiple congenital anomalies (i.e., renal, urogenital, and limb anomalies) can result from pathogenic variants in many KIF genes. We expand the phenotype associated with KIF4A variants from developmental delay and intellectual disability with or without epilepsy to a congenital anomaly phenotype with hydrocephalus and various brain anomalies at the more severe end of phenotypic manifestations. Additional anomalies of the kidneys and urinary tract, congenital lymphedema, eye, and dental anomalies seem to be variably associated and overlap with clinical signs observed in other kinesinopathies. Caution still applies to missense variants, but hopefully, future work will further establish genotype-phenotype correlations in a larger number of patients and functional studies may give further insights into the complex function of KIF4A.
Assuntos
Anormalidades Múltiplas/genética , Encéfalo/metabolismo , Cinesinas/genética , Anormalidades Urogenitais/genética , Refluxo Vesicoureteral/genética , Anormalidades Múltiplas/patologia , Encéfalo/anormalidades , Encéfalo/patologia , Epilepsia/genética , Epilepsia/patologia , Feminino , Estudos de Associação Genética , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Masculino , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , Neurônios/metabolismo , Neurônios/patologia , Fenótipo , Anormalidades Urogenitais/patologia , Refluxo Vesicoureteral/patologiaRESUMO
BACKGROUND. Pancreatic ductal adenocarcinoma (PDAC) is highly lethal, partly because of challenges in early diagnosis. However, the prognosis for earlier stages (carcinoma in situ or category T1a invasive carcinoma) is relatively favorable. OBJECTIVE. The purpose of this study was to investigate findings of an earlier diagnosis of PDAC on CT examinations performed at least 1 year before the diagnosis of clinical stage I PDAC. METHODS. This retrospective study included 103 patients with clinical stage I PDAC and a CT examination performed at least 1 year before the CT examination that detected PDAC, as well as 103 control patients without PDAC on CT examinations separated by at least 10 years. The frequency and temporal characteristics of focal pancreatic abnormalities (pancreatic mass, main pancreatic duct [MPD] change, parenchymal atrophy, faint parenchymal enhancement, cyst, and parenchymal calcification) seen on CT examinations conducted before diagnosis (prediagnostic CT) were determined. RESULTS. A focal pancreatic abnormality was present on the most recent prediagnostic CT examination in 55/103 (53.4%) patients with PDAC versus 21/103 (20.4%) control patients (p < .001). In patients with PDAC, the most common focal abnormalities on prediagnostic CT were atrophy (39/103, 37.9%), faint enhancement (17/65, 26.2%), and MPD change (14/103, 13.6%), which were all more frequent in patients with PDAC than in control patients (p < .05). In 54/55 (98.2%) patients with PDAC, the PDAC corresponded to the site of a focal abnormality (exact location or the abnormality's upstream or downstream edge) on prediagnostic CT. Frequency of focal abnormalities decreased with increasing time before CT that detected PDAC (> 1 to ≤ 2 years before diagnosis, 64.9%; > 2 to ≤ 3 years, 49.2%; > 3 to ≤ 5 years, 41.8%; > 5 to ≤ 7 years, 29.7%; > 7 to ≤ 10 years, 18.5%; more than 10 years, 0%). Mean duration from the finding's initial appearance to diagnosis of PDAC was 4.6 years for atrophy, 3.3 years for faint enhancement, and 1.1 years for MPD change. CONCLUSION. Most patients with clinical stage I PDAC showed focal pancreatic abnormalities on CT performed at least 1 year before diagnosis. Focal MPD change exhibited the shortest duration from its development to subsequent diagnosis, whereas atrophy and faint enhancement exhibited a relatively prolonged course. CLINICAL IMPACT. These findings could facilitate earlier PDAC diagnosis and thus improve prognosis.
Assuntos
Adenocarcinoma/diagnóstico por imagem , Carcinoma Ductal Pancreático/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Ductal Pancreático/patologia , Estudos de Casos e Controles , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pâncreas/diagnóstico por imagem , Pâncreas/patologia , Ductos Pancreáticos/diagnóstico por imagem , Ductos Pancreáticos/patologia , Neoplasias Pancreáticas/patologia , Estudos RetrospectivosRESUMO
We study the dynamic switching properties of a nanomagnet under microwave electric field pumping. The periodic modulation of an anisotropy field induced by microwave electric field pumping efficiently excites the uniform magnetization oscillation, allowing for precise control of magnetization switching. Accurate shaping of the pumping voltage waveform also enables us to investigate the transient reaction of magnetization to the relative phase difference of the pumping signal. We demonstrate both experimentally and theoretically the existence of a dead angle in which the uniform oscillation of magnetization is inhibited even though the microwave frequency itself satisfies the conditions of parametric excitation. Our results provide an energy-efficient way of manipulating ultrafast magnetization dynamics in nanomagnetic devices.
RESUMO
Neuromotor systems have the capacity for functional recovery following local damage. The literature suggests a possible role for the premotor cortex and cerebellum in motor recovery. However, the specific changes to interactions between these areas following damage remain unclear. Here, we demonstrate potential rewiring of connections from the ipsilesional ventral premotor cortex (ip-PMv) to cerebellar structures in a nonhuman primate model of primary motor cortex (M1) lesion and motor recovery. Cerebellar connections arising from the ip-PMv were investigated by comparing biotinylated dextran amine (BDA) between two groups of male Macaca mulatta: M1-lesion/motor recovery group and intact group. There were more BDA-labeled boutons and axons in all ipsilesional deep cerebellar nuclei (fastigial, interposed, and dentate) in the M1-lesion/recovery group than in the intact group. The difference was evident in the ipsilesional fastigial nucleus (ip-FN), and particularly observed in its middle, a putative somatosensory region of the ip-FN, which was characterized by absent or little expression of aldolase C. Some of the altered projections from the ip-PMv to ip-FN neurons were confirmed as functional because the synaptic markers, synaptophysin and vesicular glutamate transporter 1, were colocalized with BDA-labeled boutons. These results suggest that the adult primate brain after motor lesions can reorganize large-scale networks to enable motor recovery by enhancing sensorimotor coupling and motor commands via rewired fronto-cerebellar connections.SIGNIFICANCE STATEMENT Damaging the motor cortex causes motor deficits, which can be recovered over time. Such motor recovery may result from functional compensation in remaining neuromotor areas, including the ventral premotor cortex. We investigated compensatory changes in neural axonal outputs from ventral premotor to deep cerebellar nuclei in a monkey model of primary motor cortical lesion and motor recovery. The results showed an increase in premotor projections and synaptic formations in deep cerebellar nuclei, especially the sensorimotor region of the fastigial nucleus. Our results provide the first evidence that large-scale reorganization of fronto-cerebellar circuits may underlie functional recovery after motor cortical lesions.
Assuntos
Cerebelo/fisiopatologia , Ácido Ibotênico/toxicidade , Córtex Motor/fisiopatologia , Rede Nervosa/fisiopatologia , Plasticidade Neuronal/fisiologia , Recuperação de Função Fisiológica/fisiologia , Animais , Cerebelo/efeitos dos fármacos , Macaca mulatta , Córtex Motor/efeitos dos fármacos , Rede Nervosa/efeitos dos fármacosRESUMO
Extracellular DNA (eDNA) is a biofilm component that contributes to the formation and structural stability of biofilms. Streptococcus mutans, a major cariogenic bacterium, induces eDNA-dependent biofilm formation under specific conditions. Since cell death can result in the release and accumulation of DNA, the dead cells in biofilms are a source of eDNA. However, it remains unknown how eDNA is released from dead cells and is localized within S. mutans biofilms. We focused on cell death induced by the extracellular signaling peptide called competence-stimulating peptide (CSP). We demonstrate that nucleic acid release into the extracellular environment occurs in a subpopulation of dead cells. eDNA production induced by CSP was highly dependent on the lytF gene, which encodes an autolysin. Although lytF expression was induced bimodally by CSP, lytF-expressing cells further divided into surviving cells and eDNA-producing dead cells. Moreover, we found that lytF-expressing cells were abundant near the bottom of the biofilm, even when all cells in the biofilm received the CSP signal. Dead cells and eDNA were also abundantly present near the bottom of the biofilm. The number of lytF-expressing cells in biofilms was significantly higher than that in planktonic cultures, which suggests that adhesion to the substratum surface is important for the induction of lytF expression. The deletion of lytF resulted in reduced adherence to a polystyrene surface. These results suggest that lytF expression and eDNA production induced near the bottom of the biofilm contribute to a firmly attached and structurally stable biofilm.IMPORTANCE Bacterial communities encased by self-produced extracellular polymeric substances (EPSs), known as biofilms, have a wide influence on human health and environmental problems. The importance of biofilm research has increased, as biofilms are the preferred bacterial lifestyle in nature. Furthermore, in recent years it has been noted that the contribution of phenotypic heterogeneity within biofilms requires analysis at the single-cell or subpopulation level to understand bacterial life strategies. In Streptococcus mutans, a cariogenic bacterium, extracellular DNA (eDNA) contributes to biofilm formation. However, it remains unclear how and where the cells produce eDNA within the biofilm. We focused on LytF, an autolysin that is induced by extracellular peptide signals. We used single-cell level imaging techniques to analyze lytF expression in the biofilm population. Here, we show that S. mutans generates eDNA by inducing lytF expression near the bottom of the biofilm, thereby enhancing biofilm adhesion and structural stability.
Assuntos
Biofilmes , DNA Bacteriano/metabolismo , Matriz Extracelular de Substâncias Poliméricas/fisiologia , Streptococcus mutans/fisiologia , N-Acetil-Muramil-L-Alanina Amidase/análiseRESUMO
BACKGROUND: The "hot cross bun" (HCB) sign, a cruciform hyperintensity in the pons on magnetic resonance imaging (MRI), has gradually been identified as a typical finding in multiple system atrophy, cerebellar-type (MSA-C). Few reports have evaluated the sensitivity of an HCB, including a cruciform hyperintensity and vertical line in the pons, which precedes a cruciform hyperintensity, in the early stages of MSA-C. Moreover, the difference in frequency and timing of appearance of an HCB between MSA-C and spinocerebellar ataxia type 3 (SCA3) has not been fully investigated. METHODS: This study investigated the time at which an HCB and orthostatic hypotension (OH) appeared in 41 patients with MSA-C, based on brain MRI and head-up tilt test. The MRI findings were compared with those of 26 patients with SCA3. The pontine signal findings on T2-weighted MRI were graded as 0 (no change), 1 (a vertical T2 high-intensity line), or 2 (a cruciform T2 high-intensity line), with grades 1 or 2 considered as an HCB. OH 30/15 was defined as a decrease in systolic blood pressure of > 30 mmHg or diastolic blood pressure of > 15 mmHg. RESULTS: Among the 24 patients with MSA-C within 2 years from the onset of motor symptoms, an HCB was detected in 91.7%, whereas OH 30/15 was present in 60.0%. Among the 36 patients with MSA-C within 3 years from the onset of motor symptoms, a grade 2 HCB was detected in 66.7% of those with MSA-C but in none of those with SCA-3. CONCLUSIONS: HCB is a highly sensitive finding for MSA-C, even in the early stages of the disease. A grade 2 HCB in the early stage is an extremely specific finding for differentiating MSA-C from SCA-3.
Assuntos
Hipotensão Ortostática/etiologia , Doença de Machado-Joseph/diagnóstico , Atrofia de Múltiplos Sistemas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Cerebelo/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Ponte/patologia , Estudos Retrospectivos , Adulto JovemRESUMO
Grain size is one of the most important agricultural traits in rice. To increase grain yield, we screened a large grain mutant from mutants with the 'Koshihikari' background. As a result, we obtained a mutant, KEMS39, that has a large grain size and increased yield. Cultivation tests revealed that this mutant had improved lodging resistance with thicker internodes. Next-generation sequencing analysis revealed the presence of a 67 bp deletion in the GW2 mRNA, owing to a mutation in the 3' splice site of the sixth intron of the GW2 gene. To determine whether this mutation was responsible for the larger grain and thicker internodes, we performed gene editing and obtained a mutant with a 7 bp deletion, including this 3' splice site. As this gw2 mutant had large grains and thicker internodes, the causal gene of KEMS39 was determined as GW2. Thicker internodes are attributed to the pleiotropic effect of gw2 mutation. On the basis of these results, we conclude that gw2 mutation has the potential to be an important genetic resource with the ability to achieve a well-balanced and high-yielding effect that simultaneously improves grain productivity and lodging resistance.
RESUMO
Gonadotropin-releasing hormones (GnRHs) play pivotal roles in reproduction via the hypothalamus-pituitary-gonad axis (HPG axis) in vertebrates. GnRHs and their receptors (GnRHRs) are also conserved in invertebrates lacking the HPG axis, indicating that invertebrate GnRHs do not serve as "gonadotropin-releasing factors" but, rather, function as neuropeptides that directly regulate target tissues. All vertebrate and urochordate GnRHs comprise 10 amino acids, whereas amphioxus, echinoderm, and protostome GnRH-like peptides are 11- or 12-residue peptides. Intracellular calcium mobilization is the major second messenger for GnRH signaling in cephalochordates, echinoderms, and protostomes, while urochordate GnRHRs also stimulate cAMP production pathways. Moreover, the ligand-specific modulation of signal transduction via heterodimerization between GnRHR paralogs indicates species-specific evolution in Ciona intestinalis. The characterization of authentic or putative invertebrate GnRHRs in various tissues and their in vitro and in vivo activities indicate that invertebrate GnRHs are responsible for the regulation of both reproductive and nonreproductive functions. In this review, we examine our current understanding of and perspectives on the primary sequences, tissue distribution of mRNA expression, signal transduction, and biological functions of invertebrate GnRHs and their receptors.
Assuntos
Hipotálamo/metabolismo , Invertebrados/metabolismo , Receptores LHRH/metabolismo , Animais , Evolução Biológica , Células COS , Cálcio/metabolismo , Chlorocebus aethiops , Ciona intestinalis , AMP Cíclico/metabolismo , Equinodermos , Feminino , Hormônio Liberador de Gonadotropina/metabolismo , Células HEK293 , Humanos , Ligantes , Masculino , Cadeias de Markov , Moluscos , Transdução de Sinais , Distribuição Tecidual , UrocordadosRESUMO
The digestive system is responsible for nutrient intake and defense against pathogenic microbes. Thus, identification of regulatory factors for digestive functions and immune systems is a key step to the verification of the life cycle, homeostasis, survival strategy and evolutionary aspects of an organism. Over the past decade, there have been increasing reports on neuropeptides, their receptors, variable region-containing chitin-binding proteins (VCBPs) and Toll-like receptors (TLRs) in the ascidian, Ciona intestinalis. Mass spectrometry-based peptidomes and genome database-searching detected not only Ciona orthologs or prototypes of vertebrate peptides and their receptors, including cholecystokinin, gonadotropin-releasing hormones, tachykinin, calcitonin and vasopressin but also Ciona-specific neuropeptides including Ci-LFs and Ci-YFVs. The species-specific regulation of GnRHergic signaling including unique signaling control via heterodimerization among multiple GnRH receptors has also been revealed. These findings shed light on the remarkable significance of ascidians in investigations of the evolution and diversification of the peptidergic systems in chordates. In the defensive systems of C. intestinalis, VCBPs and TLRs have been shown to play major roles in the recognition of exogenous microbes in the innate immune system. These findings indicate both common and species-specific functions of the innate immunity-related molecules between C. intestinalis and vertebrates. In this review article, we present recent advances in molecular and functional features and evolutionary aspects of major neuropeptides, their receptors, VCBPs and TLRs in C. intestinalis.
Assuntos
Ciona intestinalis , Sistema Digestório , Neuropeptídeos , Receptores de Peptídeos , Receptores Toll-Like , Animais , Ciona intestinalis/imunologia , Ciona intestinalis/metabolismo , Sistema Digestório/imunologia , Sistema Digestório/metabolismo , Neuropeptídeos/química , Neuropeptídeos/genética , Filogenia , Receptores de Peptídeos/química , Receptores de Peptídeos/genética , Especificidade da Espécie , Receptores Toll-Like/química , Receptores Toll-Like/genéticaRESUMO
OBJECTIVES: Multiple system atrophy (MSA) is a disease that combines autonomic (orthostatic or bladder) with motor [parkinsonian (MSA-P) or cerebellar (MSA-C)] dysfunction. While bladder dysfunction may occur earlier than motor disorders, thus far no prospective study has been available to determine how often and how early bladder autonomic dysfunction predates motor dysfunction in MSA. Therefore, we present data from detailed history-taking in patients with MSA. METHODS: This is a prospective cohort study. Detailed history-taking was performed and a questionnaire administered in 121 MSA patients (73 MSA-C, 48 MSA-P; 74 men, 47 women; age, 58 ± 8.0 years; initial recruitment period, 5 years; follow-up, 6.5 ± 4.0 years). RESULTS: Among the patients with MSA-C, 40 patients (55%) suffered motor dysfunction first, 22 (30%) suffered autonomic dysfunction first, and 11 (15%) initially suffered both simultaneously. Among the patients with MSA-P, 22 patients (46%) suffered motor dysfunction first, 22 (46%) suffered autonomic dysfunction first, and two (8%) initially suffered both simultaneously. Among the 'autonomic-first' subgroup of MSA-C patients, five suffered orthostatic dysfunction first, 13 suffered urinary dysfunction first, and four initially suffered both simultaneously. Among the 'autonomic-first' subgroup of MSA-P patients, six suffered orthostatic dysfunction first, nine suffered urinary dysfunction first, and seven initially suffered both simultaneously. Urinary symptoms were further preceded by erectile dysfunction in men. Overall, 18.2% of patients suffered only urinary symptoms initially, and the mean interval from the onset of urinary to the onset of motor symptoms was 2.8 years (range 1-7 years). CONCLUSION: In MSA patients, 18.2% presented with bladder dysfunction as the sole initial manifestation, and the mean interval from the onset of urinary to the onset of motor symptoms was 2.8 years. It is clinically important to avoid unnecessary prostatic surgery when MSA patients see urologists before neurologists.