Publications by authors named "Kazuyuki Nakamura"

Article Synopsis
  • Measuring mechanical forces of cell-cell interactions is key for understanding how multicellular organisms develop, but applying existing methods to tissues with cavities was uncertain.
  • The study tested a previous image-based method using simulated data and found expanding cavities introduced additional repulsive forces in cell interactions, which correctly simulated cavity structures.
  • Finally, the method was successfully applied to mouse blastocysts and two-dimensional cell sheets, demonstrating its effectiveness in modeling tissue morphologies with cavities.
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In sludge dewatering of most wastewater treatment plants (WWTPs), the dose of polymer flocculant is manually adjusted through direct visual inspection of the flocs without the aid of any instruments. Although there is a demand for the development of automatic control of flocculant dosing, this has been challenging owing to the lack of a reliable flocculation sensor. To address this issue, this study developed a novel image sensor for measuring the degree of flocculation (DF) based on deep learning.

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Background: Six percent of patients with Leigh syndrome (LS) present with infantile epileptic spasms syndrome (IESS). However, treatment strategies for IESS with LS remain unclear. This retrospective study aimed to evaluate the efficacy and safety of treatment strategies in patients with IESS complicated by LS and Leigh-like syndrome (LLS).

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Representation learning (RL) is a universal technique for deriving low-dimensional disentangled representations from high-dimensional observations, aiding in a multitude of downstream tasks. RL has been extensively applied to various data types, including images and natural language. Here, we analyze molecular dynamics (MD) simulation data of biomolecules in terms of RL.

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Article Synopsis
  • Mechanical forces play a crucial role in shaping the diverse 3D forms of multicellular systems, but understanding the specific cellular mechanical parameters influencing tissue morphology has been challenging due to limitations in live measurements.
  • A new framework was created to model the mechanical forces in cell-cell interactions by treating cells as particles and deriving effective forces based on statistical analysis of cell tracking data.
  • The study revealed that these interaction forces can be represented as pairwise potential energy that varies with cell distances, and significant differences in this energy profile exist among different species and embryonic stages, correlating with variations in their morphological characteristics.
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Autism spectrum disorder (ASD) is caused by combined genetic and environmental factors. Genetic heritability in ASD is estimated as 60-90%, and genetic investigations have revealed many monogenic factors. We analyzed 405 patients with ASD using family-based exome sequencing to detect disease-causing single-nucleotide variants (SNVs), small insertions and deletions (indels), and copy number variations (CNVs) for molecular diagnoses.

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Biallelic CC2D2A variants are associated with a wide range of neurodevelopmental disorders including Meckel syndrome. Here we report a Japanese girl with Meckel syndrome harboring a pathogenic deep intronic variant (NM_001378615.1:c.

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Article Synopsis
  • - The study focused on CDKL5 deficiency disorder (CDD) in a mouse model, which showed that seizures occur in female mice with specific genetic mutations, but not in male knockout mice or homozygous females, aiming to link genetic variants to clinical outcomes in CDD patients.
  • - It included 11 patients (6 females and 5 males), using digital PCR for genetic diagnosis and assessing their clinical features through standardized scoring methods while comparing the severity between patients with different genetic backgrounds, specifically hemizygous versus mosaic or heterozygous variants.
  • - Results indicated that all patients experienced seizures irrespective of their genetic type, but those with cellular mosaicism had less severe accompanying conditions like feeding and visual impairments. This suggests
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Pigmentary mosaicism of the Ito type, also known as hypomelanosis of Ito, is a neurocutaneous syndrome considered to be predominantly caused by somatic chromosomal mosaicism. However, a few monogenic causes of pigmentary mosaicism have been recently reported. Eleven unrelated individuals with pigmentary mosaicism (mostly hypopigmented skin) were recruited for this study.

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Article Synopsis
  • Previous research has shown glycolytic oscillations in cancer cells like HeLa and DU145 using monolayer cultures, but this study expands it to HeLa cell spheroids.
  • The findings reveal that HeLa cells in spheroids have more frequent oscillations because of increased enzyme activity, reduced glucose diffusion, and higher cell density.
  • Additionally, while nearby cells in the spheroids exhibited similar oscillation frequencies, they did not synchronize, indicating weak cell-to-cell interactions among them.
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Article Synopsis
  • The CHD5 gene, found in the critical 1p36 microdeletion region, is part of the NuRD complex essential for brain development, and variants in this gene are linked to neurodevelopmental disorders.
  • A study identified 16 individuals with heterozygous CHD5 variants via exome sequencing, revealing that most had new (de novo) mutations associated with conditions such as speech delays and learning disabilities.
  • The most common issues among these patients included language deficits (81%), behavioral problems (69%), intellectual disabilities (64%), and epilepsy (62%), indicating that CHD5 variants lead to a varied spectrum of neurodevelopmental disorders.
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Background/aim: Cancer is the most fatal disease worldwide whose most lethal characteristics are invasion and metastasis. Hepatocellular carcinoma (HCC) is one of the most fatal cancers worldwide. HCC often shows encapsulation, which is related to better prognosis.

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Polymicrogyria is a common malformation of cortical development whose etiology remains elusive. We conducted whole-exome sequencing for 124 patients with polymicrogyria and identified de novo variants in eight patients. Mutated causes functional brain diseases, including alternating hemiplegia of childhood (AHC), rapid-onset dystonia parkinsonism (RDP), and cerebellar ataxia, areflexia, pes cavus, optic nerve atrophy, and sensorineural deafness (CAPOS).

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Intellectual disability (ID) is characterized by significant limitations in both intellectual functioning and adaptive behaviors, originating before the age of 18 years. However, the genetic etiologies of ID are still incompletely elucidated due to the wide range of clinical and genetic heterogeneity. Whole genome sequencing (WGS) has been applied as a single-step clinical diagnostic tool for ID because it detects genetic variations with a wide range of resolution from single nucleotide variants (SNVs) to structural variants (SVs).

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Objective: Patients with pathogenic cyclin-dependent kinase-like-5 gene (CDKL5) variants are designated CDKL5 deficiency disorder (CDD). This study aimed to delineate the clinical characteristics of Japanese patients with CDD and elucidate possible appropriate treatments.

Methods: We recruited patients with pathogenic or likely pathogenic CDKL5 variants from a cohort of approximately 1,100 Japanese patients with developmental and epileptic encephalopathies, who underwent genetic analysis.

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High-speed atomic force microscopy (HS-AFM) is a scanning probe microscopy that can capture structural dynamics of biomolecules in real time at single molecule level near physiological condition. Albeit much improvement, while scanning one frame of HS-AFM movies, biomolecules often change their conformations largely. Thus, the obtained frame images can be hampered by the time-difference, the asynchronicity, in the data acquisition.

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Objective: To elucidate the genetic background and genotype-phenotype correlations for epilepsy with myoclonic-atonic seizures, also known as myoclonic-astatic epilepsy (MAE) or Doose syndrome.

Methods: We collected clinical information and blood samples from 29 patients with MAE. We performed whole-exome sequencing for all except one MAE case in whom custom capture sequencing identified a variant.

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MN1 was originally identified as a tumor-suppressor gene. Knockout mouse studies have suggested that Mn1 is associated with craniofacial development. However, no MN1-related phenotypes have been established in humans.

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Although there are many known Mendelian genes linked to epileptic or developmental and epileptic encephalopathy (EE/DEE), its genetic architecture is not fully explained. Here, we address this incompleteness by analyzing exomes of 743 EE/DEE cases and 2366 controls. We observe that damaging ultra-rare variants (dURVs) unique to an individual are significantly overrepresented in EE/DEE, both in known EE/DEE genes and the other non-EE/DEE genes.

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In patients with aromatic l-amino acid decarboxylase (AADC) deficiency, a decrease in catecholamines and serotonin levels in the brain leads to developmental delay and movement disorders. The beneficial effects of gene therapy in patients from 1 to 8 years of age with homogeneous severity of disease have been reported from Taiwan. We conducted an open-label phase 1/2 study of population including adolescent patients with different degrees of severity.

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Purpose: Numerous fixative solutions are available but many are not amenable to the histomorphological preservation of retinae. The investigators specifically focused on retinal histological studies, which rather than 4% formaldehyde (FA), often use Davidson's fixative. However the latter has its limitations.

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Recent studies have established important roles of de novo mutations (DNMs) in autism spectrum disorders (ASDs). Here, we analyze DNMs in 262 ASD probands of Japanese origin and confirm the "de novo paradigm" of ASDs across ethnicities. Based on this consistency, we combine the lists of damaging DNMs in our and published ASD cohorts (total number of trios, 4,244) and perform integrative bioinformatics analyses.

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Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality.

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Umbelliprenin (Umb), a natural coumarin, has demonstrated anti-tumor activities, both and particularly , in several types of cancer, including lung cancer. The present study aimed to identify molecular targets of Umb using a high-throughput approach. Lung cancer cell lines, QU-DB (large-cell lung carcinoma) and A549 (adenocarcinoma), were treated with Umb.

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