302 research outputs found
An exocyst component, Sec5, is essential for ascospore formation in Bipolaris maydis
In this study, we identified Sec5 in Bipolaris maydis, a homologue of Sec5 in Saccharomyces cerevisiae and a possible exocyst component of the fungus. To examine how Sec5 affects the life cycle of B. maydis, we generated null mutant strains of the gene (Δsec5). The Δsec5 strains showed a strong reduction in hyphal growth and a slight reduction in pathogenicity. In sexual reproduction, they possessed the ability to develop pseudothecia. However, all ascospores were aborted in any of the asci obtained from crosses between Δsec5 and the wild-type. Our cytological study revealed that the abortion was caused by impairments of the post-meiotic stages in ascospore development, where ascospore delimitation and young spore elongation occur
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Effect of pair interactions on transition probabilities between inactive and active states: achieving collective behaviour via pair interactions in social insects
To understand the evolution of well-organized social behaviour, we must first understand the mechanism by which collective behaviour establishes. In this study, the mechanisms of collective behaviour in a colony of social insects were studied in terms of the transition probability between active and inactive states, which is linked to mutual interactions. The active and inactive states of the social insects were statistically extracted from the velocity profiles. From the duration distributions of the two states, we found that 1) the durations of active and inactive states follow an exponential law, and 2) pair interactions increase the transition probability from inactive to active states. The regulation of the transition probability by paired interactions suggests that such interactions control the populations of active and inactive workers in the colony
リファキシミンは腸-肝臓-筋肉軸の調節により肝硬変ラットの骨格筋萎縮に対するL-カルニチンを介した予防効果を増強する
The gut‑liver‑muscle axis is associated with the
development of sarcopenia in liver cirrhosis. The present
study aimed to illustrate the combined effects of rifaximin
and L‑carnitine on skeletal muscle atrophy in cirrhotic rats
with steatohepatitis. For this purpose, a total of 344 Fischer
rats were fed a choline‑deficient L‑amino acid‑defined
(CD AA) diet with the daily oral administration of rifaximin
(100 mg/kg) and/or L‑carnitine (200 mg/kg), and measurements
of psoas muscle mass index and forelimb grip strength
were performed. After feeding for 12 weeks, blood samples,
and liver, ileum and gastrocnemius muscle tissues were
harvested. The effects of L‑carnitine on rat myocytes were
assessed using in vitro assays. Treatment with rifaximin
attenuated hyperammonemia and liver fibrosis in the
CD AA‑fed rats. Moreover, it improved intestinal permeability
with the restoration of tight junction proteins and
suppressed the lipopolysaccharide (LPS)‑mediated hepatic
macrophage activation and pro‑inflammatory response. In
addition, rifaximin prevented skeletal muscle mass atrophy
and weakness by decreasing intramuscular myostatin and
pro‑inflammatory cytokine levels. Moreover, rifaximin
synergistically enhanced the L‑carnitine‑mediated improvement
of skeletal muscle wasting by promoting the production
of insulin‑like growth factor‑1 and mitochondrial biogenesis,
resulting in the inhibition of the ubiquitin‑proteasome system
(UPS). The in vitro assays revealed that L‑carnitine directly
attenuated the impairment of mitochondrial biogenesis,
thereby inhibiting the UPS in rat myocytes that were stimulated
with LPS or tumor necrosis factor‑α. On the whole, the
present study demonstrates that the combination of rifaximin
with L‑carnitine may provide a clinical benefit for liver
cirrhosis‑related sarcopenia.博士(医学)・甲第863号・令和5年3月15
リファキシミンとルビプロストンの併用は脂肪性肝炎ラットの腸管バリア機能を修復し肝線維化を抑制する
Background: Although gut-derived lipopolysaccharide (LPS) affects the progression of non-alcoholic steatohepatitis (NASH) pathogenesis, few studies have focused on this relationship to develop treatments for NASH. Aims: To explore the effects of combination with rifaximin and lubiprostone on NASH liver fibrosis through the modulation of gut barrier function. Methods: To induce steatohepatitis, F344 rats were fed a choline-deficient l -amino acid-defined (CDAA) diet for 12 weeks and received oral administration of rifaximin and/or lubiprostone. Histological, molec- ular, and fecal microbial analyses were performed. Barrier function in Caco-2 cells were assessed by in vitro assays. Results: Combination rifaximin/lubiprostone treatment significantly suppressed macrophage expansion, proinflammatory responses, and liver fibrosis in CDAA-fed rats by blocking hepatic translocation of LPS and activation of toll-like receptor 4 signaling. Rifaximin and lubiprostone improved intestinal perme- ability via restoring tight junction proteins (TJPs) with the intestinal activation of pregnane X receptor and chloride channel-2, respectively. Moreover, this combination increased the abundance of Bacteroides, Lactobacillus, and Faecalibacterium as well as decreased that of Veillonella resulting in an increase of fecal short-chain fatty acids and a decrease of intestinal sialidase activity. Both agents also directly suppressed the LPS-induced barrier dysfunction and depletion of TJPs in Caco-2 cells. Conclusion: The combination of rifaximin and lubiprostone may provide a novel strategy for treating NASH-related fibrosis.博士(医学)・甲第860号・令和5年3月15
Free-breathing steady-state free precession 3D coronary MRA: investigation of the dependency on the running direction of the vessel and the direction of the motion correction
Mechanical homeostasis of liver sinusoid is involved in the initiation and termination of liver regeneration
Organogenesis and regeneration are fundamental for developmental progress and are associated with morphogenesis, size control and functional properties for whole-body homeostasis. The liver plays an essential role in maintaining homeostasis of the entire body through various functions, including metabolic functions, detoxification, and production of bile, via the three-dimensional spatial arrangement of hepatic lobules and has high regenerative capacity. The regeneration occurs as hypertrophy, which strictly controls the size and lobule structure. In this study, we established a three-dimensional sinusoidal network analysis method and determined valuable parameters after partial hepatectomy by comparison to the static phase of the liver. We found that mechanical homeostasis, which is crucial for organ morphogenesis and functions in various phenomena, plays essential roles in liver regeneration for both initiation and termination of liver regeneration, which is regulated by cytokine networks. Mechanical homeostasis plays critical roles in the initiation and termination of organogenesis, tissue repair and organ regeneration in coordination with cytokine networks
RNA Modification in Inflammatory Bowel Diseases
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder characterized by damage to the intestinal mucosa, which is caused by a combination of factors. These include genetic and epigenetic alterations, environmental influence, microorganism interactions, and immune conditions. Some populations with IBD show a cancer-prone phenotype. Recent studies have provided insight into the involvement of RNA modifications in the specific pathogenesis of IBD through regulation of RNA biology in epithelial and immune cells. Studies of several RNA modification-targeting reagents have shown preferable outcomes in patients with colitis. Here, we note a new awareness of RNA modification in the targeting of IBD and related diseases, which will contribute to early diagnosis, disease monitoring, and possible control by innovative therapeutic approaches
Optimization of quantum noise in space gravitational-wave antenna DECIGO with optical-spring quantum locking considering mixture of vacuum fluctuations in homodyne detection
Quantum locking using optical spring and homodyne detection has been devised
to reduce quantum noise that limits the sensitivity of DECIGO, a space-based
gravitational wave antenna in the frequency band around 0.1 Hz for detection of
primordial gravitational waves. The reduction in the upper limit of energy
density from to
, as inferred from recent observations, necessitates
improved sensitivity in DECIGO to meet its primary science goals. To accurately
evaluate the effectiveness of this method, this paper considers a detection
mechanism that takes into account the influence of vacuum fluctuations on
homodyne detection. In addition, an advanced signal processing method is
devised to efficiently utilize signals from each photodetector, and design
parameters for this configuration are optimized for the quantum noise. Our
results show that this method is effective in reducing quantum noise, despite
the detrimental impact of vacuum fluctuations on its sensitivity.Comment: 12 pages, 5 figure
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