<ORIGINAL ARTICLE>Actin Filaments of Taste Buds in the Goldfish and Parrot

The filaments in the apical region of the taste bud cells of both goldfish and parrot were examined by fluorescence histochemistry and electron microscopy. The apical cytoplasm of goldfish taste buds terminated in long, slender processes and microvilli, and contained thin and straight filaments composed of f-actin, as detected by fluorecein-labeled phalloidin binding. In the parrot, the apical cytoplasm of taste buds terminating in microvilli also showed phalloidin fluorescence. The result suggests that the apex of taste buds of most vertebrate species is composed of actin filaments

<ORIGINAL ARTICLE>Histochemical Localization of Carbonic Anhydrase in the Taste Buds of the Mouse and Goldfish

The activity of carbonic anhydrase in the taste buds of the mouse and goldfish was examined by enzyme histochemistry. An intense reaction of carbonic anhydrase was observed in the middle and basal regions of the taste buds in the mouse circumvallate papillae. Under the electron microscope, the reaction product was found in the cytoplasm of type-I cells which are characterized by the presence of ribosomes and rough endoplasmic reticulum. In other cell types (type-II and type-Ill cells), no reaction was detected. In the fungiform papillae, the reactivity was similar to that in the circumvallate ones; however, only a few cells were positively stained. In the goldfish, the receptor cells, which are characterized by the presence of tubular system, showed strong carbonic anhydrase activity. The results suggest that the activity of carbonic anhydrase, which is usually associated with H^+ or HCOs transport, is present in a specific type of taste bud cells

Accelerated Fibrinolysis and Its Propagation on Vascular Endothelial Cells by Secreted and Retained tPA

We successfully visualized the secretory dynamics of tissue-type plasminogen activator (tPA) tagged by green fluorescent protein (tPA-GFP) from cultured vascular endothelial cells (VECs) using total internal reflection fluorescence (TIRF) microscopy and demonstrated that tPA-GFP secreted from VECs was retained on cell surfaces in a heavy-chain-dependent manner. Progressive binding of Alexa568-labeled Glu-plasminogen was also observed on the surface of active tPA-GFP expressing cells via lysine binding sites (LBS), which was not observed on inactive mutant tPA-GFP expressing cells. These results suggest that retained tPA on VECs effectively activated plasminogen to plasmin, which then facilitated the binding of additional plasminogen on the cell surface by proteolytically cleaving surface-associated proteins and exposing their C-terminal lysine residues. Thus prolonged retention of tPA appeared to play an important role in initiating and amplifying plasmin generation on VECs. LBS-dependent binding of plasminogen was also observed as a narrow band at the lytic front of the fibrin mesh formed on active tPA-GFP expressing cells, which expanded outward as the lytic area increased. This binding was not observed on inactive mutant tPA-GFP expressing cells or in the presence of aprotinin. The binding of plasminogen to partially digested fibrin appears to be indispensable for spontaneous fibrinolysis

<ORIGINAL ARTICLE>Stem cells of olfactory cells during embryonic development

胎生期のマウスの嗅上皮と鋤鼻器の嗅細胞の幹細胞についてブロモデオキシウリジン(BrdU)と神経細胞接着分子(NCAM)の抗体を用いた二重染色と電顕により調べた。妊娠マウスにBrdUを投与し1時間後屠殺すると,胎生12日目の嗅上皮と鋤鼻器では上皮全体にBrdU標識細胞が多数みられ,活発に分裂していることが示唆された。これらの細胞は円柱形で,少数のリボゾーム,粗面小胞体を有しNCAM陰性であった。これらの細胞の間にNCAM陽性の嗅細胞が少数みられた。胎生14日目には,円柱形細胞は上皮の基底側に限局するようになった。円柱形細胞のBrdU標識は,BrdU投与24時間後には大部分,上皮中央の嗅細胞層へ移動することから,この円柱形細胞が嗅細胞へ分化することが示唆された。胎生17～19日目には,円柱形細胞は,鋤鼻器ではNCAM陽性の丸い細胞に,嗅上皮では二種類の基底細胞(globose basal cells, basal cells proper)に置き代るようになる。Stem cells of olfactory (receptor) cells in the olfactory epithelium and vomeronasal organ during embryonic development of mice were investigated by double immunostaining using anti-neural cell adhesion molecule (NCAM) and anti-bromodeoxyuridine (BrdU) antibodies and by electron microscopy. The columnar-shaped cells which were negative for NCAM and located throughout the epithelium on embryonic day (E) 12 and then in the basal region after E 14, were numerously labeled with BrdU, indicating active division, when BrdU was injected 1 hr before sacrifice. These cells are presumed to develop into NCAM-immunoreactive olfactory (receptor) cells of the middle region of the epithelium since numerous labelings appeared in the middle region 24 hrs after injection of BrdU. Evidence of migration of the columnar cells from olfactory epithelium along the axons was observed. On E 17, the columnar cells in the vomeronasal organ became round-shaped, located above the processes of the supporting cells, and were stained with NCAM. On the other hand, the columnar cells in the olfactory epithelium differentiated into round-shaped cells and pyramidal-shaped cells on E 19, which respectively corresponded to globose basal cells and basal cells proper seen in postnatal epithelium, although the round-shaped cells were negative for NCAM. The result suggests that the columnar cells as stem cells of olfactory (recepetor) cells observed in embryonic days differentiate into round-shaped cells in late embryonic days and that cells in the olfactory epithelium mature at a later stage than those in the VNO

Factors related to hospital nurse intention to leave: Does striving for work-life balance and sense of coherence affect wishes to stay in the organization?

The aim of this study is to identify relationships between striving for work-life balance (S-WLB), sense of coherence (SOC), and intention to leave among hospital nurses. In August of 2017, we conducted a self-administered questionnaire survey to 2239 nurses at nine public hospitals. The questionnaire included demographic factors, work environmental factors, organizational factors, striving for worklife balance, a 13-item SOC, the Maslach Burnout Inventory, and intention to leave. We carried out a multiple regression analysis with intention to leave as the dependent variable and others as independent variables. We obtained valid responses from 1368 full-time employed nurses (61.1%). The mean age of respondents was 36.38 ± 10.18 years, and the length of clinical experience 13.4 ± 9.65 years. The mean total score of the intention to leave was 14.58 ± 5.09. As a result of the multiple regression analysis, the SWLB and the SOC were found to be statistically related to the intention to leave even after controlling for the confounding factor of burnout. In addition, the satisfaction of desire level for the actual working assignment at the workplace was a significant independent factor. In this study, the full-time nursing staff had a low intention to leave score when they had a high score in the SWLB and the SOC. It was also found that the level of satisfaction with appointment to a desired assignment is a significant factor in the intention to leave. In establishing an attractive workplace for nursing staff, it is important to create a workplace environment and supports to be able to properly evaluate workplace satisfaction after assignments are made while taking into account individual S-WLB and SOC functions

マウス歯発生時におけるインシュリン様成長因子ファミリーの遺伝子発現(Gene expression of insulin-like growth factor family during tooth development of the mouse)

マウス臼歯発生時におけるインシュリン様成長因子(IGF)とIGF結合蛋白質(IGFBP)の発現の時間的・空間的パターンを調べた。IGFとIGFBP発現はin situハイブリダイゼーションにて決定した。E14マウス胚の帽状期、E15胚の帽状期後期、E17-P0の鐘状期、P0-P13のクラウン形成期、P5-P13のルート形成期につき、IGF-I、IGF-II、IGFBP-2、-3、-4、-5、IGF-I受容体(IGF-IR)の発現部位と時期を網羅した。IGFおよびその作用調節因子は歯の成長分化の局所仲介因子となり、歯胚の上皮と間充織で局所的に発現するIGFBP-2、-3、-4、-5は歯の成長分化に役割を果たす可能性が示唆された。マウス臼歯発生時におけるインシュリン様成長因子(IGF)とIGF結合蛋白質(IGFBP)の発現の時間的・空間的パターンを調べた。IGFとIGFBP発現はin situハイブリダイゼーションにて決定した。E14マウス胚の帽状期、E15胚の帽状期後期、E17-P0の鐘状期、P0-P13のクラウン形成期、P5-P13のルート形成期につき、IGF-I、IGF-II、IGFBP-2、-3、-4、-5、IGF-I受容体(IGF-IR)の発現部位と時期を網羅した。IGFおよびその作用調節因子は歯の成長分化の局所仲介因子となり、歯胚の上皮と間充織で局所的に発現するIGFBP-2、-3、-4、-5は歯の成長分化に役割を果たす可能性が示唆された

Des couples iraniens en migration

L’Iran représente le quatrième pays d’origine des migrants en Suède. L’engouement des Iraniens pour ce pays ne s’est pas démenti entre la première vague d’immigration faisant suite à l’avènement de la République islamique et la seconde après l’élection présidentielle de 2005. Si les réfugiés iraniens trouvent en Suède des conditions d’accueil favorables pour eux et leur famille, fondée sur la politique multiculturaliste, leur intégration culturelle dans cette nouvelle société censée n’avoir aucune similitude avec leur pays d’origine demande à chacun un énorme investissement

Causal Model of Work Engagement among Registered Nurses and Licensed Practical Nurses Working in Long-Term Care Contexts in Japan

The objective of this study was to determine a causal process underlying work engagement, in which individual resources (i.e., resilience) and job resources influence work performance, mediated by work engagement in different types of nurses working in long-term care contexts. We investigated a work engagement causal model in which individual and job resources were set as antecedent factors, work engagement as a mediating factor, and work performance as the outcome, to clarify differences between registered nurses (RNs) and licensed practical nurses (LPNs) working in long-term care contexts. We conducted a questionnaire-based survey with 1,786 Japanese nurses working in long-term care contexts in the Tohoku region. Using 1,269 respondents, we examined the causal model using structural equation modeling (SEM) and multiple population analysis to compare between RNs and LPNs. The results revealed a process whereby individual and job resources influenced work performance, mediated by work engagement, in RNs. In other words, greater individual and job resources enhance pride in work and positive emotion (i.e., work engagement), and greater positive emotion improves work performance. This process was not equivalent in LPNs. In LPNs, the most significant factor affecting work performance was the direct effect of job resources; moreover, the mediating effect of work engagement was not supported. The results demonstrated that in order to improve performance among LPNs working in long-term care contexts, it is important to provide job resource support, as well as to facilitate positive emotion through pride in one’s work

Unique secretory dynamics of tissue plasminogen activator and its modulation by plasminogen activator inhibitor-1 in vascular endothelial cells

We analyzed the secretory dynamics of tissue plasminogen activator (tPA) in EA.hy926 cells, an established vascular endothelial cell (VEC) line producing GFP-tagged tPA, using total internal reflection fluorescence (TIR-F) microscopy. tPA-GFP was detected in small granules in EA.hy926 cells, the distribution of which was indistinguishable from intrinsically expressed tPA. Its secretory dynamics were unique, with prolonged (>5min.) retention of the tPA-GFP on the cell surface, appearing as fluorescent spots in two-thirds of the exocytosis events. The rapid disappearance (mostly by 250ms) of a domain-deletion mutant of tPA-GFP possessing only the signal peptide and catalytic domain indicates that the amino-terminal heavy chain of tPA-GFP is essential for binding to the membrane surface. The addition of PAI-1 dose-dependently facilitated the dissociation of membrane-retained tPA and increased the amounts of tPA-PAI-1 high molecular weight complexes in the medium. Accordingly, suppression of PAI-1 synthesis in EA.hy926 cells by siRNA prolonged the dissociation of tPA-GFP, whereas a catalytically inactive mutant of tPA-GFP not forming complexes with PAI-1 remained on the membrane even after PAI-1 treatment. Our results provide new insights into the relationship between exocytosed, membrane-retained tPA and PAI-1, which would modulate cell surface-associated fibrinolytic potential