ER Stress, Secretory Granule Biogenesis, and Insulin

Insulin is secreted from pancreatic β-cells, and the high demand of insulin biosynthesis is known to cause β-cell dysfunction in patients with type 2 diabetes mellitus. The insulin biosynthetic pathway has been extensively studied and is still an exciting area for future studies. In this chapter, first, we focus on proinsulin biosynthetic pathway in the endoplasmic reticulum (ER) and recent progress of our knowledge about ER stress. We discuss about how ER stress is involved in the development of diabetes. Second, we focus on the formation of insulin secretory granules. The biogenesis of secretory granules has been explored for several decades; however, it still has been debated and has yet to be understood. We review the current knowledge about the secretory granules and discuss about the problems for future studies

Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours

BACKGROUND: Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm). Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. RESULTS: Large consort males transfer smaller (average total length = 73 μm) sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm) sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. CONCLUSIONS: Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external), whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size

Drop Metastasis of Adrenocorticotropic Hormone-Producing Pituitary Carcinoma to the Cauda Equina

The diagnosis of pituitary carcinoma cannot be made easily histologically, and most cases of pituitary carcinoma are diagnosed only after the clinical detection of metastasis. Distant metastasis of pituitary tumor occurs in 0.1% to 0.2% of cases and has been reported in the liver, bone and central nervous system, with only one case of metastasis to the cauda equine reported. This study describes a rare case of the drop metastasis of adrenocorticotropic hormone-producing pituitary adenocarcinoma to the cauda equina, causing cauda equina syndrome

看護師のストレスマネジメントに関する文献検討

本研究の目的は、看護師のストレスマネジメントに関する研究を概観し、今後の取り組むべき研究課題を検討することである。ストレスマネジメントの研究の内容は、尺度の開発と尺度の有用性、ストレス要因、心の健康状態と関連要因、コーピングと関連要因、ストレスマネジメントに対する研修会の検討の5つに分類できた。今後の研究課題として、①ストレスマネジメントを測定できる尺度の検討、②ストレスマネジメントの肯定的な側面に注目した研究の必要性、③ストレスマネジメント研修会の検討の3点が明らかになった

Glaucomatous Visual Field Defect Severity and the Prevalence of Motor Vehicle Collisions in Japanese: A Hospital/Clinic-Based Cross-Sectional Study

Purpose. This study examined the association between the severity of visual field defects and the prevalence of motor vehicle collisions (MVCs) in subjects with primary open-angle glaucoma (POAG). Methods. This is a cross-sectional study. Japanese patients who have had driver’s licence between 40 and 85 years of age were screened for eligibility. Participants answered a questionnaire about MVCs experienced during the previous 5 years. Subjects with POAG were classified as having mild, moderate, or severe visual field defect. We evaluated associations between the severity of POAG and the prevalence of MVCs by logistic regression models. Results. The prevalence of MVCs was significantly associated with the severity of POAG categorized by worse eye MD (control: 30/187 = 16.0%; mild POAG: 17/92 = 18.5%; moderate POAG: 14/60 = 23.3%; severe POAG: 14/47 = 29.8%; P=0.025, Cochran-Armitage trend test). Compared to the control group, the adjusted OR for MVC prevalence in subjects with mild, moderate, or severe POAG in the worse eye was 1.07 (95% CI: 0.55 to 2.10), 1.44 (95% CI: 0.68 to 3.08), and 2.28 (95% CI: 1.07 to 4.88). Conclusions. There is a significant association between the severity of glaucoma in the worse eye MD and the prevalence of MVCs

ArfGAPs: key regulators for receptor sorting

Mammalian cells have many membranous organelles that require proper composition of proteins and lipids. Cargo sorting is a process required for transporting specific proteins and lipids to appropriate organelles, and if this process is disrupted, organelle function as well as cell function is disrupted. ArfGAP family proteins have been found to be critical for receptor sorting. In this review, we summarize our recent knowledge about the mechanism of cargo sorting that require function of ArfGAPs in promoting the formation of transport vesicles, and discuss the involvement of specific ArfGAPs for the sorting of a variety of receptors, such as MPR, EGFR, TfR, Glut4, TRAIL-R1/DR4, M5-muscarinic receptor, c-KIT, rhodopsin and β1-integrin. Given the importance of many of these receptors to human disease, the studies of ArfGAPs may provide novel therapeutic strategies in addition to providing mechanistic insight of receptor sorting

ArfGAP1 function in COPI mediated membrane traffic: Currently debated models and comparison to other coat-binding ArfGAPs

The ArfGAPs are a family of proteins containing an ArfGAP catalytic domain that induces the hydrolysis of GTP bound to the small guanine nucleotide binding-protein ADP-ribosylation factor (Arf). Functional models for Arfs, which are regulators of membrane traffic, are based on the idea that guanine nucleotide-binding proteins function as switches: Arf with GTP bound is active and binds to effector proteins; the conversion of GTP to GDP inactivates Arf. The cellular activities of ArfGAPs have been examined primarily as regulatory proteins that inactivate Arf; however, Arf function in membrane traffic does not strictly adhere to the concept of a simple switch, adding complexity to models explaining the role of ArfGAPs. Here, we review the literature addressing the function Arf and ArfGAP1 in COPI mediated transport, focusing on two critical and integrated functions of membrane traffic, cargo sorting and vesicle coat polymerization. We briefly discuss other ArfGAPs that may have similar function in Arf-dependent membrane traffic outside the ER-Golgi

POTENTIAL ENERGY SURFACES AND BRANCHING RATIO OF THE DISSOCIATIVE RECOMBINATION REACTION HCNH++e−HCNH^{+}{_+}e^{-}: AN {AB INTIO MOLECULAR ORBITAL STUDY}

Author Institution: Department of Chemistry, Faculty of Science, Ochanomizu University; Department of Information Sciences, Faculty of Science, Ochanomizu University; Department of Applied Chemistry, Faculty of Engineering, University of TokyoTwo dimensional potential energy surfaces for the dissociative recombination reaction. $HCNH^{+} + e^{-} \rightarrow (HCNH)- \rightarrow HCN/HNC +$H, have teen calculated by the CASSCF-MRSDCI/cc-pVQZ {ab initio} molecular orbital method. Near the $HCNH^{+}$ ground state surface, which also represents the upper limit of the neutral HCNH Rydbergs state surface, only two dissociative valence states of The HCNH are located: One is the ${^{2}} \Sigma^{+}$ state resulting in the H-C bond seission yielding HNC and the other the ${^{2}} \Sigma^{+}$ state resulting in the H-N bond session yielding HCN. The seam of intersection of these two surfaces almost bisects the zero-point vibrational wave function of the Rydberg-limit state of the neutral HCNH species, indicating that, while descending Rydberg ladder, transition to each dissociative surface occurs with almost equal probability. Thus, the branching ratio [HNC]/[HCN] is predicted to be nearly one or slightly more, explaining the thermochemically unrealistic interstellar |HNC]/[HCN] ratio of 4.4 observed toward L134N