tip functionalization
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The distal end of the eukaryotic flagellum/cilium is important for axonemal growth and signaling and has distinct biomechanical properties. Specific flagellum tip structures exist, yet their composition, dynamics, and functions are largely unknown. We used biochemical approaches to identify seven constituents of the flagella connector at the tip of an assembling trypanosome flagellum and three constituents of the axonemal capping structure at the tips of both assembling and mature flagella. Both tip structures contain evolutionarily conserved as well as kinetoplastid-specific proteins, and component assembly into the structures occurs very early during flagellum extension. Localization and functional studies reveal that the flagella connector membrane junction is attached to the tips of extending microtubules of the assembling flagellum by a kinesin-15 family member. On the opposite side, a kinetoplastid-specific kinesin facilitates attachment of the junction to the microtubules in the mature flagellum. Functional studies also suggest roles of several other components and the definition of subdomains in the tip structures.
The shape and form of the flagellated eukaryotic parasite Leishmania is sculpted to its ecological niches and needs to be transmitted to each generation with great fidelity. The shape of the Leishmania cell is defined by the sub-pellicular microtubule array and the positioning of the nucleus, kinetoplast and the flagellum within this array. The flagellum emerges from the anterior end of the cell body through an invagination of the cell body membrane called the flagellar pocket. Within the flagellar pocket the flagellum is laterally attached to the side of the flagellar pocket by a cytoskeletal structure called the flagellum attachment zone (FAZ). During the cell cycle single copy organelles duplicate with a new flagellum assembling alongside the old flagellum. These are then segregated between the two daughter cells by cytokinesis, which initiates at the anterior cell tip. Here, we have investigated the role of the FAZ in the morphogenesis of the anterior cell tip. We have deleted the FAZ filament protein, FAZ2 and investigated its function using light and electron microscopy and infection studies. The loss of FAZ2 caused a disruption to the membrane organisation at the anterior cell tip, resulting in cells that were connected to each other by a membranous bridge structure between their flagella. Moreover, the FAZ2 null mutant was unable to develop and proliferate in sand flies and had a reduced parasite burden in mice. Our study provides a deeper understanding of membrane-cytoskeletal interactions that define the shape and form of an individual cell and the remodelling of that form during cell division.
- MeSH
- buněčná membrána MeSH
- cytokineze MeSH
- cytoskelet metabolismus MeSH
- flagella fyziologie ultrastruktura MeSH
- interakce hostitele a parazita * MeSH
- Leishmania růst a vývoj ultrastruktura MeSH
- leishmanióza parazitologie MeSH
- morfogeneze * MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- protozoální proteiny genetika metabolismus MeSH
- Psychodidae parazitologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
INTRODUCTION: Stroke is one of the most feared complications during catheter ablation of atrial fibrillation (AF). While symptomatic thromboembolic events are rare, magnetic resonance imaging (MRI) may identify asymptomatic (ie, silent) cerebral lesions (SCLs) following pulmonary vein isolation (PVI) procedures. METHODS AND RESULTS: The REDUCE-TE Pilot was a prospective multicenter, single-arm observational study investigating the incidence of SCL in patients with symptomatic paroxysmal AF undergoing PVI with a novel gold-tip, externally irrigated ablation catheter. After ablation, cerebral diffusion-weighted MRI and a postablation follow-up were performed at 1 to 3 days after the ablation procedure. A neurocognitive test was done before and after ablation. The primary study endpoint was the occurrence of one or more new SCLs. Secondary study endpoints included neurocognitive status, procedural success rate, and periprocedural complications including symptomatic thromboembolic events. A total of 104 patients were enrolled (69% male, mean age: 61.5 ± 9.7 years, mean CHA2 DS 2 -VASc score: 1.7 ± 1.2). Postprocedural MRI examination was performed in 97 patients, and in nine of them (9.3%; 95% CI: 4.3-16.9%) a total of 11 SCLs were detected. Univariate analyses did not reveal any significant predictor for new SCLs. Nonsignificant trends were observed for low activated clotting time during ablation and for international normalized ratio value outside the range of 2 to 3 at ablation. There was no evidence of significant deterioration of neurocognitive function after PVI. In four patients, a pericardial tamponade was noted but all patients fully recovered during follow-up. CONCLUSIONS: Ablation of AF using a novel gold-tip, externally irrigated ablation catheter, resulted in SCLs in approximately one out of 10 patients without a measurable effect on neurocognitive function.
- MeSH
- akční potenciály MeSH
- asymptomatické nemoci MeSH
- časové faktory MeSH
- design vybavení MeSH
- difuzní magnetická rezonance MeSH
- fibrilace síní komplikace diagnóza patofyziologie chirurgie MeSH
- incidence MeSH
- intrakraniální embolie diagnostické zobrazování epidemiologie MeSH
- katetrizační ablace škodlivé účinky přístrojové vybavení MeSH
- kognice * MeSH
- léčebná irigace škodlivé účinky přístrojové vybavení MeSH
- lidé středního věku MeSH
- lidé MeSH
- pilotní projekty MeSH
- pooperační kognitivní dysfunkce diagnóza epidemiologie psychologie MeSH
- senioři MeSH
- srdeční frekvence MeSH
- srdeční katétry * MeSH
- testy pro posouzení mentálních funkcí a demence MeSH
- venae pulmonales patofyziologie chirurgie MeSH
- výsledek terapie MeSH
- zlato * MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- pozorovací studie MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Německo MeSH
Uzavření defektu hrotu nosu má svá specifika vzhledem k jeho tvaru, barvě, síle a textuře kůže. Při rekonstrukci musíme respektovat estetické a funkční hledisko k optimalizaci výsledku. Existuje více způsobů uzavření defektu v této lokalizaci. Jednou z možností je využít některý z místních laloků. Při výběru optimálního postupu je vhodné brát v úvahu rozdělení nosu na estetické podjednotky. Využití V-Y laloku má své výhody ve srovnání s rotačním nebo transpozičním lalokem, u kterých mohou vznikat další patrné jizvy a deformace jako např. „dog-ear“. Tento stav může následně vyžadovat další úpravu. Erçöçen et al. popsali V-Y ostrůvkový dorzální nosní lalok, který použili k uzavření defektu hrotu nosu. Lalok oboustranně zásobují terminální větve arteria angularis (1). V našem případě jsme k uzavření defektu hrotu použili výše zmíněný lalok, který jsme vypreparovali pouze na terminálních větvích arteria angularis jedné strany.
Closure of a nasal tip defect has specific characteristics with regards to the shape, colour, thickness and texture of skin. During the reconstruction it is necessary to observe aesthetic and functional characteristics to achieve an optimal result. There are several methods for closure of a defect in this area. One of the possible techniques is usage of a local flap. In the selection of an optimal procedure it is suitable to consider the aesthetic subunits in the nose. Usage of the V-Y flap is beneficial compared to a rotation flap or a transposition flap, which are associated with significant scaring and deformities, such as a dog-ear. Such conditions may require further corrections later. Erçöçen et al. described a V-Y island dorsal nasal flap, which they used to close a nasal tip defect. The blood supply of the flap was based on the terminal branches of angular artery on both sides (1). In our case report we used the aforementioned flap to close a nasal defect. The flap was based on the terminal branches of the angular artery only on one side.
- MeSH
- bazocelulární karcinom * chirurgie MeSH
- chirurgické laloky krevní zásobení MeSH
- lidé MeSH
- nádory kůže chirurgie MeSH
- nádory nosu * chirurgie MeSH
- senioři nad 80 let MeSH
- zákroky plastické chirurgie * metody MeSH
- Check Tag
- lidé MeSH
- senioři nad 80 let MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
INTRODUCTION: Frequent ventricular premature complexes (VPCs) may cause symptoms and/or lead to deterioration of LV systolic function. Although frequent VPCs may be abolished by catheter ablation, it may be challenging in case of their origin from the LV papillary muscles (PMs). Our collaborative study aimed to analyze in detail the site of origin and the outcome of ablation. METHODS: Consecutive 34 patients (males: 68%; aged 62 ± 12 years; LV ejection fraction: 50 ± 9%) undergoing catheter ablation of VPCs originating from PMs were included. All procedures were guided by intracardiac echocardiography. RESULTS: The size and shape of PMs were highly variable. The length of anterolateral and posteromedial PM was 23 ± 4 mm and 28 ± 7 mm, respectively. In about one-third of patients, the PM was formed by two distinctly separate heads. The ectopic foci were located on anterolateral, posteromedial or both PM in 35%, 56% and 9% of cases, respectively. Their location was found within the distal, mid, or proximal (basal) third of PM in the 67%, 19%, and 14%, respectively. A total of 86% of PM foci were acutely abolished and long-term success was achieved in 65% of patients. Absence of VPCs of other morphologies and a high burden of ectopic activity before ablation were associated with favorable clinical outcome. CONCLUSION: VPCs originate predominantly from the distal portion of the PM. This knowledge may facilitate the mapping in patients with infrequent ectopic beats. Intracardiac echocardiography is of crucial importance for navigation of the ablation catheter and for assessment of its stability at PM target sites.
- MeSH
- akční potenciály MeSH
- časové faktory MeSH
- echokardiografie MeSH
- elektrofyziologické techniky kardiologické MeSH
- funkce levé komory srdeční * MeSH
- katetrizační ablace MeSH
- komorové extrasystoly diagnóza patofyziologie chirurgie MeSH
- lidé středního věku MeSH
- lidé MeSH
- papilární svaly diagnostické zobrazování patofyziologie chirurgie MeSH
- senioři MeSH
- srdeční frekvence * MeSH
- srdeční komory diagnostické zobrazování patofyziologie chirurgie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- Geografické názvy
- Evropa MeSH
PURPOSE OF THE STUDY: This study investigated the relationship between the position of the tip of the coracoid process (CP) relative to the glenoid with subscapularis (Ssc) tears. We hypothesized that the coracoid tip is more inferior, lateral and posterior in patients with Ssc tear. MATERIAL AND METHODS: This research enrolled 34 isolated Ssc tears and 44 controls. We introduced the axial central glenoid-coracoid angle (acGCA) and sagittal central glenoid-coracoid angle (scGCA) to evaluate the position of the tip of the CP relative to the glenoid center on MRI images. In both groups, acGCA, scGCA on MRI and critical shoulder angle (CSA), glenoid inclination (GI) on true anterior-posterior shoulder radiography were evaluated. RESULTS: When both groups were compared in terms of acGCA, the acGCA values of the Ssc tear group were significantly higher than the control group (p<0.001). The best cut-off value of acGCA for Ssc tears was 28.3°. acGCA values higher than 28.3° showed 93.3% sensitivity and 93.1% specificity for Ssc tears (likelihood ratio:13.53, AUC: 0.979, 95% CI of AUC: 0.950- 0.999). In terms of acGCA, the power analysis between Ssc tears group and control group was 99.9% between Ssc tears and the control group (effect size d=2.63). When both groups were compared in terms of scGCA, the scGCA values of the Ssc tear group were significantly higher than the control group (p<0.001). The best cut-off value of scGCA for Ssc tears was 41.4°. Scores of scGCA greater than 41.8° showed 80% sensitivity and 89.7% specificity for Ssc tears (likelihood ratio: 7.73, AUC: 0.899 95% CI of AUC: 0.837-0.958). In terms of scGCA, the power analysis between Ssc tear and control group was 99.8% (effect size d=1.23). When both groups were compared in terms of CSA and GI; CSA and GI values in the Ssc tear group were significantly higher (p<0.001 and p<0.012, respectively). CONCLUSIONS: AcGCA values higher than 28.3° indicate that the coracoid tip is located more laterally and posteriorly; scGCA values higher than 41.8° indicate that the coracoid tip is located more inferiorly and these two new indexes are showing that more laterally, posteriorly and inferiorly coracoid tip is related to subscapularis tears. KEY WORDS: coracoid process, subscapularis tear, coracoid morphology, scapula morphology.
- MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie * metody MeSH
- poranění rotátorové manžety * diagnostické zobrazování MeSH
- processus coracoideus * zranění diagnostické zobrazování MeSH
- ramenní kloub diagnostické zobrazování MeSH
- senzitivita a specificita MeSH
- studie případů a kontrol MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The exocyst, a eukaryotic tethering complex, coregulates targeted exocytosis as an effector of small GTPases in polarized cell growth. In land plants, several exocyst subunits are encoded by double or triple paralogs, culminating in tens of EXO70 paralogs. Out of 23 Arabidopsis thaliana EXO70 isoforms, we analyzed seven isoforms expressed in pollen. Genetic and microscopic analyses of single mutants in EXO70A2, EXO70C1, EXO70C2, EXO70F1, EXO70H3, EXO70H5, and EXO70H6 genes revealed that only a loss-of-function EXO70C2 allele resulted in a significant male-specific transmission defect (segregation 40%:51%:9%) due to aberrant pollen tube growth. Mutant pollen tubes grown in vitro exhibited an enhanced growth rate and a decreased thickness of the tip cell wall, causing tip bursts. However, exo70C2 pollen tubes could frequently recover and restart their speedy elongation, resulting in a repetitive stop-and-go growth dynamics. A pollen-specific depletion of the closest paralog, EXO70C1, using artificial microRNA in the exo70C2 mutant background, resulted in a complete pollen-specific transmission defect, suggesting redundant functions of EXO70C1 and EXO70C2. Both EXO70C1 and EXO70C2, GFP tagged and expressed under the control of their native promoters, localized in the cytoplasm of pollen grains, pollen tubes, and also root trichoblast cells. The expression of EXO70C2-GFP complemented the aberrant growth of exo70C2 pollen tubes. The absent EXO70C2 interactions with core exocyst subunits in the yeast two-hybrid assay, cytoplasmic localization, and genetic effect suggest an unconventional EXO70 function possibly as a regulator of exocytosis outside the exocyst complex. In conclusion, EXO70C2 is a novel factor contributing to the regulation of optimal tip growth of Arabidopsis pollen tubes.
- MeSH
- Arabidopsis genetika růst a vývoj metabolismus MeSH
- geneticky modifikované rostliny MeSH
- konfokální mikroskopie MeSH
- kořeny rostlin genetika metabolismus MeSH
- mutace MeSH
- protein - isoformy genetika metabolismus MeSH
- proteiny huseníčku genetika metabolismus MeSH
- pyl genetika růst a vývoj metabolismus MeSH
- pylová láčka genetika růst a vývoj metabolismus MeSH
- regulace genové exprese u rostlin * MeSH
- vezikulární transportní proteiny genetika metabolismus MeSH
- vývojová regulace genové exprese * MeSH
- zelené fluorescenční proteiny genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Cieľ práce: Úprava hypospádie metódou tubularizovanej incidovanej platničky (TIP) bola prvýkrát publikovaná v roku 1994, v súčasnosti si získala širokú popularitu. Cieľom chirurgickej liečby je vytvoriť funkčne a kozmeticky normálny penis. Cieľom práce je poukázať na naše skúsenosti s použitím TIP.
Objective: Tubularized incised plate (TIP) was first described in 1994 by Snodgrass and today is very popular. The aim of hypospadias surgery is to achieve a normal function and cosmetical appearance of penis. The aim of our retrospective study was to summarize our experience with this method.
Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis.
- MeSH
- acyltransferasy genetika metabolismus MeSH
- Arabidopsis genetika růst a vývoj metabolismus účinky záření MeSH
- cytokininy metabolismus farmakologie MeSH
- fenotyp MeSH
- membránové lipidy biosyntéza MeSH
- meristém účinky léků genetika růst a vývoj účinky záření MeSH
- morfogeneze * účinky léků účinky záření MeSH
- mutace MeSH
- proteiny huseníčku genetika metabolismus MeSH
- regulace genové exprese u rostlin účinky léků účinky záření MeSH
- semenáček účinky léků genetika růst a vývoj účinky záření MeSH
- tma MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
