Correlated Light-Serial Scanning Electron Microscopy (CoLSSEM) for ultrastructural visualization of single neurons in vivo

A challenging aspect of neuroscience revolves around mapping the synaptic connections within neural circuits (connectomics) over scales spanning several orders of magnitude (nanometers to meters). Despite significant improvements in serial section electron microscopy (SSEM) technologies, several major roadblocks have impaired its general applicability to mammalian neural circuits. In the present study, we introduce a new approach that circumvents some of these roadblocks by adapting a genetically-encoded ascorbate peroxidase (APEX2) as a fusion protein to a membrane-targeted fluorescent reporter (CAAX-Venus), and introduce it in single pyramidal neurons in vivo using extremely sparse in utero cortical electroporation. This approach allows us to perform Correlated Light-SSEM (CoLSSEM), a variant of Correlated Light-EM (CLEM), on individual neurons, reconstructing their dendritic and axonal arborization in a targeted way via combination of high-resolution confocal microscopy, and subsequent imaging of its ultrastructural features and synaptic connections with ATUM-SEM (automated tape-collecting ultramicrotome - scanning electron microscopy) technology. Our method significantly will improve the feasibility of large-scale reconstructions of neurons within a circuit, and permits the description of some ultrastructural features of identified neurons with their functional and/or structural connectivity, one of the main goal of connectomics

Ice sheet history in the southern part of the Soya Coast, East Antarctica revealed by glacial landforms and surface exposure dating

The Tenth Symposium on Polar Science/Ordinary sessions: [OG] Polar Geosciences, Wed. 4 Dec. / 3F Seminar room, National Institute of Polar Researc

ER-mitochondria tethering by PDZD8 regulates Ca2+ dynamics in mammalian neurons

Interfaces between organelles are emerging as critical platforms for many biological responses in eukaryotic cells. In yeast, the ERMES complex is an endoplasmic reticulum (ER)-mitochondria tether composed of four proteins, three of which contain a SMP (synaptotagmin-like mitochondrial-lipid binding protein) domain. No functional ortholog for any ERMES protein has been identified in metazoans. Here, we identified PDZD8 as an ER protein present at ER-mitochondria contacts. The SMP domain of PDZD8 is functionally orthologous to the SMP domain found in yeast Mmm1. PDZD8 was necessary for the formation of ER-mitochondria contacts in mammalian cells. In neurons, PDZD8 was required for calcium ion (Ca2+) uptake by mitochondria after synaptically induced Ca2+-release from ER and thereby regulated cytoplasmic Ca2+ dynamics. Thus, PDZD8 represents a critical ER-mitochondria tethering protein in metazoans. We suggest that ER-mitochondria coupling is involved in the regulation of dendritic Ca2+ dynamics in mammalian neurons

Multiple episodes of ice loss from the Wilkes Subglacial Basin during the Last Interglacial

The Last Interglacial (LIG: 130,000–115,000 years ago) was a period of warmer global mean temperatures and higher and more variable sea levels than the Holocene (11,700–0 years ago). Therefore, a better understanding of Antarctic ice-sheet dynamics during this interval would provide valuable insights for projecting sea-level change in future warming scenarios. Here we present a high-resolution record constraining ice-sheet changes in the Wilkes Subglacial Basin (WSB) of East Antarctica during the LIG, based on analysis of sediment provenance and an ice melt proxy in a marine sediment core retrieved from the Wilkes Land margin. Our sedimentary records, together with existing ice-core records, reveal dynamic fluctuations of the ice sheet in the WSB, with thinning, melting, and potentially retreat leading to ice loss during both early and late stages of the LIG. We suggest that such changes along the East Antarctic Ice Sheet margin may have contributed to fluctuating global sea levels during the LIG

Expression of HER2 and MUC1 in Advanced Colorectal Cancer: Frequency and Clinicopathological Characteristics

There have been many reports on the overexpression of human epidermal growth factor receptor 2 (HER2) in patients with colon cancer. However, the role and frequency of HER2 overexpression have not been clearly defined. Anti-HER2 therapy has been shown to improve the prognosis of HER2-positive patients with breast and stomach cancers. In this study, we explored HER2 expression in patients with colon cancer at stages II and III by immunohistochemistry (IHC) and dual-color in situ hybridization (DISH), and examined the correlation between HER2 expression and clinicopathological factors. Moreover, we examined the correlation between HER2 expression and mucin 1 (MUC1) expression. The subjects were 121 patients with colon cancer at stages II and III who underwent surgery in our hospital during the period from 2007 to 2009. Sections containing the deepest part of a lesion were subjected to immunostaining for HER2 and MUC1. HER2 expression was assessed in accordance with Ventana\u27s Guidelines for HER2 Testing in Stomach Cancer, with sections comprising less than 10% of weakly to moderately stained tumor cells scored as 1 > 2. HER2 expression scored as 2 was defined with sections comprising more than 10% of the weakly to moderately stained tumor cells. Patients with a score of 1 > 2 and 2 were also subjected to DISH using a Dual ISH HER2 kit. MUC1 expression was scored according to the percentage of stained area as follows: 0, 0 to 5%; 1, 5 to 50%; and 2, 50% and higher. Patients with a score of 1 and 2 were defined as MUC1-positive. The analysis of HER2 by IHC yielded the following scores: 45 patients (37.2%), 0; 38 patients (31.4%), 1; 14 patients (11.6%); 1 > 2; 24 patients (19.8%), 2; and 0 patients (0%), 3. For the 38 patients with a score of 1 > 2 and 2, DISH returned ratios of HER2 to Chr17 expression (HER2: Chr17 ratio) from 1.13 to 1.93 (mean = 1.46). There was no significant correlation between HER2 expression and clinicopathological factors. The numbers of MUC1-positive patients according to HER2 score were as follows: 22 patients (48.9%) in the score 0 group (45 patients); 25 patients (65.8%) in the score 1 group (38 patients); 10 patients (71.4%) in the score 1 > 2 group (14 patients), and 22 patients (91.7%) in the score 2 group (24 patients). There was a positive correlation between HER2 expression and MUC1 expression. Specifically, MUC1 expression levels increased with HER2 expression level, and the percentage of MUC1-positive patients was significantly higher in the HER2 score 2 group than in the HER2 score 0 group (P < 0.01). Rates of HER2 positivity by DISH or fluorescence in situ hybridization (FISH) in patients who had an HER2 score of 2+ by IHC were 45% and 24% in the patients with stomach and breast cancers, respectively. However, the positivity rate was 0% in the patients with colon cancer in this study. This result indicates that patients with colon cancer who have an IHC HER2 score of 2+ are more likely to be HER2 negative by DISH than patients with breast and stomach cancers, although larger cohort studies are required before a definitive conclusion can be made. There was a positive correlation between HER2 expression and MUC1 expression in this study, although further examination is required because there were no patients who had an HER2 score of 3+ or 2+ by IHC and were HER2 positive by DISH in this study. HER2 expression in colon cancer should be cautiously assessed by both IHC and DISH

Clinicopathologtcal Study of Serrated Polyps of the Colorectum, with Special Reference to Maspin Expression

Aims: We compared the clinicopathologic features of three types of colorectal serrated polyps, namely, hyperplastic polyps (HPs), sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs), and analyzed the expression pattern of maspin in these serrated lesions. We retrospectively examined 173 polypoid lesions that were endoscopically excised from 136 patients and diagnosed as hyperplastic or adenomatous serrated lesions, and histologically classified as HPs, SSA/Ps, or TSAs. Maspin expression was immunohistochemically examined in all lesions. Overall, 59 lesions (34%) were classified as HPs, 70 (40%) as SSA/Ps and 44 (25%) as TSAs. There were no significant differences in mean age or gender of patients between types, but SSA/Ps frequently developed on the right colon and showed a superficial/flat elevation, whereas HPs and TSAs frequently developed on the left colon and showed protruded lesions. The average diameters of HPs, SSA/Ps, and TSAs were 7.2, 9.9, and 12.9mm, respectively, showing significant differences. Diffuse cytoplasmic expression of maspin was observed in the serrated glands of all three types. In addition, focal or diffuse intranuclear localization of maspin was observed in 15% of HPs, 13% of SSA/Ps, and 84% of TSAs, showing significant differences between TSAs and the other two types. The three types of serrated polyp examined in this study showed distinct clinicopathological features. The presence of maspin expression in these polyps, regardless of whether they were hyperplastic or neoplastic, indicates that maspin might be commonly associated with cell proliferation, although the underlying mechanism might be different between types

A Clinicopathological Study of Primary Small Intestinal Cancer with Emphasis on Cellular Characteristics

We examined the clinicopathological profiles and cellular characteristics of 10 cases of surgically resected primary small intestinal cancers (excluding duodenal cancers). Histological examination revealed nine adenocarcinomas and one sarcomatoid carcinoma. Invasion depth was subserosal in five cases, serosal in four cases and to the adjacent transverse colon in the remaining case. Metastasis was present in lymph node in seven cases, in distant organs in six, and in the peritoneum in seven cases. Of the 10 cases, 7 underwent postoperative chemotherapy, and 6 of the eight traceable patients died from the disease (mean period of survival: 386 days). Histomorphologically, eight of nine adenocarcinomas showed an intestinal phenotype (unclassifiable in the other) in the upper layer, while in the lower layer, there showed an intestinal phenotype and five a non-intestinal phenotyp. Immunohistochemistry revealed a mean positive rate in the upper/lower layers as follows: 93%/86% and 38%/29% by intestinal markers CDX2 and MUC2; 19%/28% and 13%/32% by pancreatobiliary markers CK7 and MUC1; and 4%/19% and 2%/9% by gastric markers MUC5AC and MUC6, respectively. Thus, the intestinal phenotype predominated in almost all small intestinal cancer in this study, although some showed a transformation to non-intestinal or hybrid phenotypes with tumor progression. Flexible management for the diversity and transformation of cellular characteristics is therefore recommended treating and diagnosing small intestinal cancers

A Case of Unusual Polypoid Mixed Hemangioma of the Sigmoid Colon: Possibly an Angioadenomatous Polyp

Herein, we report on an unusual case of polypoid mixed hemangioma of the sigmoid colon. An 85-year-old woman who underwent colonoscopic examination was found to have a smooth, red polypoid tumor, 6mm in diameter, in the sigmoid colon. The polyp was resected endoscopically. Microscopically, the polyp contained two pathologic components: (i) adenomatous proliferative glands as the epithelial component; and (ii) mixed hemangioma as the mesenchymal component. On the basis of these findings, a pathological diagnosis of angioadenomatous polyp was made. Although seven previous cases of polypoid hemangioma located in the submucosa have been reported in the literature, the present case is the first in which the hemangioma is localized only in the mucosa. The mixed hemangioma may be the pathogen stimulating the adenomatous proliferation of the glands

Pneumonia Caused by Severe Acute Respiratory Syndrome Coronavirus 2 and Influenza Virus: A Multicenter Comparative Study

Background: Detailed differences in clinical information between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia (CP), which is the main phenotype of SARS-CoV-2 disease, and influenza pneumonia (IP) are still unclear. Methods: A prospective, multicenter cohort study was conducted by including patients with CP who were hospitalized between January and June 2020 and a retrospective cohort of patients with IP hospitalized from 2009 to 2020. We compared the clinical presentations and studied the prognostic factors of CP and IP. Results: Compared with the IP group (n = 66), in the multivariate analysis, the CP group (n = 362) had a lower percentage of patients with underlying asthma or chronic obstructive pulmonary disease (P < .01), lower neutrophil-to-lymphocyte ratio (P < .01), lower systolic blood pressure (P < .01), higher diastolic blood pressure (P < .01), lower aspartate aminotransferase level (P < .05), higher serum sodium level (P < .05), and more frequent multilobar infiltrates (P < .05). The diagnostic scoring system based on these findings showed excellent differentiation between CP and IP (area under the receiver operating characteristic curve, 0.889). Moreover, the prognostic predictors were different between CP and IP. Conclusions: Comprehensive differences between CP and IP were revealed, highlighting the need for early differentiation between these 2 pneumonias in clinical settings

Rapid glaciation and a two-step sea-level plunge into The Last Glacial Maximum

The approximately 10,000-year-long Last Glacial Maximum, before the termination of the last ice age, was the coldest period in Earth’s recent climate history1. Relative to the Holocene epoch, atmospheric carbon dioxide was about 100 parts per million lower and tropical sea surface temperatures were about 3 to 5 degrees Celsius lower2,3. The Last Glacial Maximum began when global mean sea level (GMSL) abruptly dropped by about 40 metres around 31,000 years ago4 and was followed by about 10,000 years of rapid deglaciation into the Holocene1. The masses of the melting polar ice sheets and the change in ocean volume, and hence in GMSL, are primary constraints for climate models constructed to describe the transition between the Last Glacial Maximum and the Holocene, and future changes; but the rate, timing and magnitude of this transition remain uncertain. Here we show that sea level at the shelf edge of the Great Barrier Reef dropped by around 20 metres between 21,900 and 20,500 years ago, to −118 metres relative to the modern level. Our findings are based on recovered and radiometrically dated fossil corals and coralline algae assemblages, and represent relative sea level at the Great Barrier Reef, rather than GMSL. Subsequently, relative sea level rose at a rate of about 3.5 millimetres per year for around 4,000 years. The rise is consistent with the warming previously observed at 19,000 years ago1,5, but we now show that it occurred just after the 20-metre drop in relative sea level and the related increase in global ice volumes. The detailed structure of our record is robust because the Great Barrier Reef is remote from former ice sheets and tectonic activity. Relative sea level can be influenced by Earth’s response to regional changes in ice and water loadings and may differ greatly from GMSL. Consequently, we used glacio-isostatic models to derive GMSL, and find that the Last Glacial Maximum culminated 20,500 years ago in a GMSL low of about −125 to −130 metres.Financial support of this research was provided by the JSPS KAKENHI (grant numbers JP26247085, JP15KK0151, JP16H06309 and JP17H01168), the Australian Research Council (grant number DP1094001), ANZIC, NERC grant NE/H014136/1 and Institut Polytechnique de Bordeaux