Imaging of a large collection of human embryo using a super-parallel MR microscope.

Using 4 and 8-channel super-parallel magnetic resonance (MR) microscopes with a horizontal bore 2.34T superconducting magnet developed for 3-dimensional MR microscopy of the large Kyoto Collection of Human Embryos, we acquired T(1)-weighted 3D images of 1204 embryos at a spatial resolution of (40 microm)(3) to (150 microm)(3) in about 2 years. Similarity of image contrast between the T(1)-weighted images and stained anatomical sections indicated that T(1)-weighted 3D images could be used for an anatomical 3D image database for human embryology.     

Graphic and movie illustrations of human prenatal development and their application to embryological education based on the human embryo specimens in the Kyoto collection.

Morphogenesis in the developing embryo takes place in three dimensions, and in addition, the dimension of time is another important factor in development. Therefore, the presentation of sequential morphological changes occurring in the embryo (4D visualization) is essential for understanding the complex morphogenetic events and the underlying mechanisms. Until recently, 3D visualization of embryonic structures was possible only by reconstruction from serial histological sections, which was tedious and time-consuming. During the past two decades, 3D imaging techniques have made significant advances thanks to the progress in imaging and computer technologies, computer graphics, and other related techniques. Such novel tools have enabled precise visualization of the 3D topology of embryonic structures and to demonstrate spatiotemporal 4D sequences of organogenesis. Here, we describe a project in which staged human embryos are imaged by the magnetic resonance (MR) microscope, and 3D images of embryos and their organs at each developmental stage were reconstructed based on the MR data, with the aid of computer graphics techniques. On the basis of the 3D models of staged human embryos, we constructed a data set of 3D images of human embryos and made movies to illustrate the sequential process of human morphogenesis. Furthermore, a computer-based self-learning program of human embryology is being developed for educational purposes, using the photographs, histological sections, MR images, and 3D models of staged human embryos.     

Heat-shock induced nuclear retention and recycling inhibition of importin alpha

Heat-shock induces a strong stress response and modifies all aspects of cellular physiology, which involves dynamic changes in the nucleocytoplasmic distributions of a variety of proteins. Many distinct nucleocytoplasmic transport pathways exist in eukaryotic cells, but how a particular transport pathway is regulated under different cellular conditions remains elusive. The finding of this study indicate that conventional nuclear import, which is mediated by importin alpha/beta, is down-regulated, while the nuclear import of 70 kD heat-shock cognate protein is up-regulated in heat-shock cells. Among the factors involved in the mediation of the conventional nuclear import, significant levels of importin alpha accumulate in the nucleus in response to heat-shock. An analysis of the behaviour of importin alpha with fluorescence recovery after photobleaching and fluorescence loss in photobleaching studies show that nuclear importin alpha becomes less mobile and its nucleocytoplasmic recycling is impaired in heat-shock cells. These data coincided well with biochemical and cytological studies. Our present data show that heat-shock induces the nuclear accumulation, nuclear retention, and recycling inhibition of importin alpha, resulting in the suppression of conventional nuclear import. This suggests a new regulatory mechanism for the adaptation of cells to environmental changes, such as heat-shock.     

Genetic verification of the role of CCK-AR in pancreatic proliferation and blood glucose and insulin regulation using a congenic rat carrying CCK-AR null allele

A number of studies have indicated that cholecystokinin type A receptor (CCK-AR) plays a crucial role in postnatal pancreatic proliferation and blood glucose regulation through stimulating insulin secretion. The Otsuka Long-Evans Tokushima Fatty (OLETF) rat has been shown to possess poor pancreatic proliferation (PPP) capability after pancreatectomy (Px). Here we have constructed a congenic strain which introgressed an OLETF-derived 18.5 cM genomic fragment identified in our previous quantitative trait locus (QTL) analysis as a locus responsible for PPP into normoglycemic F344 genetic background The introgressed region includes CCK-AR null mutation. After Px, the congenic rat showed weak pancreatic proliferation equivalent to that of the OLETF rat. Furthermore, post-surgery non-fasting blood glucose levels for the congenic rats are significantly higher in comparison with the F344 rats. At 28 days after Px, the congenic rats also showed lower blood insulin levels than the F344 rats. These results further provide the genetic evidence that 1) CCK-AR is essential for pancreatic regeneration; 2) impaired pancreatic proliferation mediates the development of hyperglycemia.     

Chromosomal and microsatellite instability in sporadic gastric cancer

BACKGROUND: Gastric cancer can progress through two pathways of genomic instability: chromosomal (CIN) and microsatellite instability (MSI). It is hypothesized that these two pathways are not always independent and that some tumors show overlap between these two mechanisms. METHODS: A total of 98 sporadic gastric cancers were classified based on their MSI status, using microsatellite assay with BAT26. Evidence for CIN was investigated by identifying loss of heterozygosity (LOH) events on chromosome arms, 5q, 10p, 17p, 17q, and 18q, which are regions harboring tumor suppressor genes that are significant in gastric cancer development. RESULTS: Twelve tumors (12%) showed high-frequency MSI (MSI-H). Overall, 43 of the tumors (44%) had at least one LOH event, with most frequent chromosomal losses observed on 10p and 18q (30%, respectively), followed by 5q (21%), 17p (14%), and 17q (12%). Interestingly, overlap was observed between CIN and MSI pathways. Of 43 cancers with LOH events, four (9%) were also MSI-H. It was also found that 48% of cancers without MSI-H had no LOH events identified, comprising a subgroup of tumors that were not representative of either of these two pathways of genomic instability. CONCLUSION: These results suggest that molecular mechanisms of genomic instability are not necessarily independent and may not be fully defined by either the MSI or CIN pathways in sporadic gastric cancers.     

Chronic Alcohol Abuse Leads to Gastric Atrophy and Decreased Gastric Secretory Capacity: A Histological and Physiological Study

We performed morphological and physiological studies in 43 male patients with alcohol dependence (ALC) who had no other apparent lesions in the upper gastrointestinal tract except atrophic and erosive gastritis. A gastric secretory study in which tetragastrin was used as the stimulant revealed that acid and pepsin secretion was less in ALC patients than in hospital controls (p less than 0.001). Endoscopic biopsy specimens of gastric mucosa from ALC patients revealed that atrophy of the gastric mucosa advanced with age. A strong negative correlation was also found between the secretory capacity of the stomach and the degree of atrophy. Possibly, the interval between recurrent episodes of acute mucosal damage was too short to allow complete healing of mucosal lesions. Failure to regenerate denuded epithelium would result in a decrease in the gastric secretory area. Thus, chronic alcohol abuse seems to be an etiological factor in atrophic gastritis.     

Wide QRS Complex and Lateral ST-T Segment Abnormality Are Associated With Worse Clinical Outcomes in COVID-19 Patients

BackgroundThe information on electrocardiographic features of patients with coronavirus disease 2019 (COVID-19) is limited. Our aim was to determine if baseline electrocardiographic features of hospitalized COVID-19 patients are associated with markers of myocardial injury and clinical outcomes.MethodsIn this retrospective, single center cohort study, we included 223 hospitalized patients with laboratory-confirmed COVID-19. Clinical, electrocardiographic and laboratory data were collected and analyzed. Primary composite endpoint of mortality, need for invasive mechanical ventilation, or admission to the intensive care unit was assessed.ResultsForty patients (17.9%) reached the primary composite endpoint. Patients with the primary composite endpoint were more likely to have wide QRS complex (>120 ms) and lateral ST-T segment abnormality. The multivariable Cox regression showed increasing odds of the primary composite endpoint associated with acute respiratory distress syndrome (odds ratio 7.76, 95% CI 2.67–22.59; p < 0.001), acute cardiac injury (odds ratio 3.14, 95% CI 1.26–7.99; p = 0.016), high flow oxygen therapy (odds ratio 2.43, 95% CI 1.05–5.62; p = 0.037) and QRS duration longer than >120 ms (odds ratio 3.62, 95% CI 1.39–9.380; p = 0.008) Patients with a wide QRS complex (>120 ms) had significantly higher median level of troponin T and pro-BNP than those without it. Patients with abnormality of lateral ST-T segment had significantly higher median level of troponin T and pro-BNP than patients without.ConclusionsThe presence of QRS duration longer than 120 ms and lateral ST-T segment abnormality were associated with worse clinical outcomes and higher levels of myocardial injury biomarkers.