Apex

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Apex

  • cardiac apex
  • open apex
  • radiographic apex
  • right ventricular apex
  • root apex
  • shoot apex
  • tip apex
  • ventricular apex

  • Terms modified by Apex

  • apex predator
  • apex removal

  • Selected Abstracts


    Impacts of Alternative Manure Application Rates on Texas Animal Feeding Operations: A Macro Level Analysis,

    JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2008
    E. Osei
    Abstract:, An integrated economic and environmental modeling system was developed for evaluating agro-environmental policies and practices implemented on large scales. The modeling system, the Comprehensive Economic and Environmental Optimization Tool-Macro Modeling System (CEEOT-MMS), integrates the Farm-level Economic Model (FEM) and the Agricultural Policy Environmental eXtender (APEX) model, as well as national databases and clustering and aggregation algorithms. Using micro simulations of statistically derived representative farms and subsequent aggregation of farm-level results, a wide range of agricultural best management practices can be investigated within CEEOT-MMS. In the present study, CEEOT-MMS was used to evaluate the economic and water quality impacts of nitrogen (N) and phosphorus (P) based manure application rates when implemented on all animal feeding operations in the State of Texas. Results of the study indicate that edge-of-field total P losses can be reduced by about 0.8 kg/ha/year or 14% when manure applications are calibrated to supply all of the recommended crop P requirements from manure total P sources only, when compared to manure applications at the recommended crop N agronomic rate. Corresponding economic impacts are projected to average a US$4,800 annual cost increase per farm. Results are also presented by ecological subregion, farm type, and farm size categories. [source]


    APEX: A new map of the cold dust in our galaxy

    ASTRONOMY & GEOPHYSICS, Issue 4 2009
    Article first published online: 20 JUL 200
    An atlas of the Milky Way galaxy at submillimetre wavelengths will prove a useful guide for forthcoming science from ALMA and Herschel. [source]


    Safety and efficacy of bortezomib in high-risk and elderly patients with relapsed multiple myeloma

    BRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2007
    Paul G. Richardson
    Summary Adverse prognostic factors in multiple myeloma include advanced age, number of prior therapies, and higher International Staging System (ISS) disease stage. In the international, randomised, phase-3 Assessment of Proteasome Inhibition for Extending Remissions (APEX) study, bortezomib demonstrated significantly longer time to progression (TTP), higher response rates and improved survival compared with high-dose dexamethasone in patients with relapsed multiple myeloma following one to three prior therapies. In this APEX subgroup analysis, efficacy of bortezomib and dexamethasone was compared in elderly (age ,65 years) and high-risk (>1 prior line of therapy; ISS stage II/III; refractory to prior therapy) patients. Bortezomib demonstrated substantial clinical activity in these patients. Response rate (34,40% vs. 13,19%), including complete response rate (5,8% vs. 0,1%), was significantly higher with bortezomib versus dexamethasone in all four subgroups. Similarly, median TTP was significantly longer with bortezomib versus dexamethasone, and 1-year survival probability was significantly higher in all subgroups. As in the total APEX population, rates of grade 3/4 adverse events were higher in bortezomib- versus dexamethasone-treated patients aged ,65 years and with >1 prior line, while rates of serious adverse events were similar; toxicities generally proved manageable. Bortezomib should be considered an appropriate treatment for elderly and high-risk patients with relapsed multiple myeloma. [source]


    APEX (Assessment of Pexelizumab in Acute Myocardial Infarction)

    CLINICAL CARDIOLOGY, Issue 1 2007
    Article first published online: 29 JAN 200
    No abstract is available for this article. [source]


    Accuracy of three different electronic apex locators in detecting simulated horizontal and vertical root fractures

    AUSTRALIAN ENDODONTIC JOURNAL, Issue 2 2006
    Aqeel K. Ebrahim bds
    Abstract The aim of this in vitro study was to evaluate the accuracy of three electronic apex locators (EALs): Root ZX, Foramatron D10 and Apex NRG, in the detection of fractures in teeth having simulated horizontal and vertical root fractures. A total of 90 extracted intact, straight, single-rooted teeth were divided into six groups of 15 teeth each. In Groups A, B and C, an incomplete horizontal fracture was simulated by preparing a horizontal incision in the coronal, middle or apical portion of the root until the circumferential half of the canal was exposed in the horizontal plane respectively. In Groups D, E and F, an incomplete vertical root fracture was simulated by preparing a vertical straight incision to expose the canal in the coronal, middle or apical portion of the root all the way in the longitudinal plane respectively. The simulated fractures were 0.25 mm in thickness in all groups. The teeth were embedded in 1% agar and the canals were irrigated with saline solution during electronic measurement. Detection of the simulated root fractures was established with a size 10 K-file when the meter value reached ,APEX' on each EAL. In Groups A, B and C, Kruskal,Wallis tests revealed that there were no statistically significant differences between the three EALs. However, statistically significant differences were found among the EALs in Groups D, E and F (P < 0.0001, one-way anova and Tukey's post-hoc test). In conclusion, the three EALs tested were accurate and acceptable clinical tools in the detection of horizontal root fractures. However, the three EALs were unreliable in detecting the position of vertical root fractures. [source]


    Factors associated with cancer distress in the Asbestos Post-Exposure Survey (APEXS),

    AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 4 2009
    Marion Maurel MSc
    Abstract Objectives CT-scan screening programs for lung cancer detection have been proposed in high-risk subjects, and more recently in former asbestos-exposed subjects. However, to date no data are available on psychological impact of such programs. The aim of this study is to examine the risk factors of psychological distress at baseline of a CT-scan screening program among asbestos-exposed subjects. Methods The Asbestos Post-Exposure Survey (APEXS) was carried out in France between October 2003 and December 2005 in order to screen asbestos-related diseases by CT-scan. Volunteers underwent self-administered questionnaires including an asbestos exposure assessment and, for a large sub-sample, a validated psychological distress scale. Non-exposed subjects were used as reference group. Results At baseline, a significant higher level of distress was observed in exposed subjects (n,=,3,122) relative to the reference group (n,=,486) after adjustment on age, sex, and tobacco status. This distress is associated independently with the self-perception of (i) intensity of asbestos exposure and (ii) the risk of current or future disease related to the asbestos exposure. The perception of the cancer risk related to asbestos seems to play a fundamental role in this psychological distress. Conclusion In this study, asbestos-exposed subjects experienced a higher significant cancer distress than previously described in literature. These findings may be of potential public health importance. First, the impact of such occupational exposures on quality of life of patients who suffer from cancer related to these exposures has to be appraised. Secondly, the assessment of psychological impact of CT-scan screening programs among asbestos-exposed subjects is also required. Am. J. Ind. Med. 52:288,296, 2009. © 2009 Wiley-Liss, Inc. [source]


    Engineering antibody fragments to fold in the absence of disulfide bonds

    PROTEIN SCIENCE, Issue 2 2009
    Min Jeong Seo
    Abstract Disulfide bonds play a critical role in the stabilization of the immunoglobulin ,-sandwich sandwich. Under reducing conditions, such as those that prevail in the cytoplasm, disulfide bonds do not normally form and as a result most antibodies expressed in that compartment (intrabodies) accumulate in a misfolded and inactive state. We have developed a simple method for the quantitative isolation of antibody fragments that retain full activity under reducing conditions from large mutant libraries. In E. coli, inactivation of the cysteine oxidoreductase DsbA abolishes protein oxidation in the periplasm, which leads to the accumulation of scFvs and other disulfide-containing proteins in a reduced form. Libraries of mutant scFvs were tethered onto the inner membrane of dsbA cells and mutants that could bind fluorescently labeled antigen in the reducing periplasm were screened by Anchored Periplasmic Expression (APEx; Harvey et al., Proc Natl Acad Sci USA 2004;101:9193,9198.). Using this approach, we isolated scFv antibody variants that are fully active when expressed in the cytoplasm or when the four Cys residues that normally form disulfides are substituted by Ser residues. [source]


    TWO NEW SPECIES OF MICROGASTER LATREILLE (HYMENOPTERA: BRACONIDAE) FROM CHINA,

    INSECT SCIENCE, Issue 3 2000
    XU Wei-an
    Abstract The present paper describes two new species of Microgaster Latreille, 1804, viz: M. longiterebra sp. nov. (,) and M. longicaudatus sp. nov. (,). M. longiterebra sp. nov. is described from Kunming, Yunnan Prov. in China closely related to M. subcompletus, but differs from the latter in the combination of the following features: 1) APOL as long as OD; 2) Mesonotum strongly punctate on anterior 2/ 3) r shorter than width of stigma; 4) cu-a of hind wing medially curved; 5) Apex of hypopygium ending far beyond apex of abdomen. M. longicaudatus sp. nov. is described from Tianmushan, Zhejiang Prov. in China closely related to M. ductilis, but differs from the latter in the combination of the following features: 1) middle and hind femora reddish yellow only with apical 1/4 blackish; 2) 1-SR 0.5 times as long as 1-M; 3) the hairy part of ovipositor sheath 0.5 times as long as hind tibia; 4) tergite 3 with slightly weaker rugosity. The type specimens are deposited in Zhejiang University, Hangzhou, China. [source]


    Behavioural responses of the seven-spot ladybird Coccinella septempunctata to plant headspace chemicals collected from four crop Brassicas and Arabidopsis thaliana, infested with Myzus persicae

    AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2008
    R. D. Girling
    Abstract 1,Insects using olfactory stimuli to forage for prey/hosts are proposed to encounter a ,reliability,detectability problem', where the usability of a stimulus depends on its reliability as an indicator of herbivore presence and its detectability. 2,We investigated this theory using the responses of female seven-spot ladybirds Coccinella septempunctata (Coleoptera: Coccinellidae) to plant headspace chemicals collected from the peach-potato aphid Myzus persicae and four commercially available Brassica cultivars; Brassica rapa L. cultivar ,turnip purple top', Brassica juncea L. cultivar ,red giant mustard', Brassica napus L. cultivar ,Apex', Brassica napus L. cultivar ,Courage' and Arabidopsis thaliana. For each cultivar/species, responses to plants that were undamaged, previously infested by M. persicae and infested with M. persicae, were investigated using dual-choice Petri dish bioassays and circular arenas. 3,There was no evidence that ladybirds responded to headspace chemicals from aphids alone. Ladybirds significantly preferred headspace chemicals from B. napus cv. Apex that were undamaged compared with those from plants infested with aphids. For the other four species/cultivars, there was a consistent trend of the predators being recorded more often in the half of the Petri dish containing plant headspace chemicals from previously damaged and infested plants compared with those from undamaged ones. Furthermore, the mean distance ladybirds walked to reach aphid-infested A. thaliana was significantly shorter than to reach undamaged plants. These results suggest that aphid-induced plant chemicals could act as an arrestment or possibly an attractant stimulus to C. septempunctata. However, it is also possible that C. septempunctata could have been responding to aphid products, such as honeydew, transferred to the previously damaged and infested plants. 4,The results provide evidence to support the ,reliability,detectability' theory and suggest that the effectiveness of C. septempunctata as a natural enemy of aphids may be strongly affected by which species and cultivar of Brassica are being grown. [source]


    Interpectoral approach to dissection of the Axillary Apex: An elegant and effective approach

    JOURNAL OF SURGICAL ONCOLOGY, Issue 3 2006
    Ajit Pai MS
    Abstract Background Axillary dissection is the goldstandard for treatment of the axilla. It provides important prognostic information, accurately stages the axilla, and has the lowest recurrence rate among all modalities. In today's age of conservation surgery, the axilla is often addressed through a cosmetically acceptable small incision with limited access, thereby making clearance of the level III nodes difficult. Methods We describe a method of apical lymph node dissection through the interpectoral plane, which effectively clears the apex despite the constraints of limited exposure. Results This method has been used in nearly 5,000 axillary dissections performed at our institute, with excellent results. It preserves the innervation of the pectoral muscles and affords access to the interpectoral nodes. Conclusions Our method has a short learning curve, provides good exposure of a difficult area and consistently provides a good yield of nodes. J. Surg. Oncol. 2006;94:252,254. © 2006 Wiley-Liss, Inc. [source]


    Time-course Expression of DNA Repair-related Genes in Hepatocytes of Zebrafish (Danio rerio) After UV-B Exposure

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2009
    Juliana Z. Sandrini
    The objective of this study was to evaluate the time-course effects of UV-B exposure on expression of genes involved in the DNA repair system of zebrafish (Danio rerio) hepatocytes, a highly competent species in terms of damage repair induced by UV radiation. For gene expression analysis (RT-PCR), cells were exposed to 23.3 mJ cm,2 UV-B, which was the dose that affected viable cell number (reduction of 30% when compared with the control group) and produced no visual alteration on cell morphology. The early response observed (6 h) showed induction in the expression of the CDKI gene (cyclin-dependent kinase inhibitor) and genes related to DNA damage repair (mainly XPC and DDB2), while the late response observed (24 h) was more related to up-regulation of p53 and genes involved in cell cycle arrest (gadd45a, cyclinG1). In all times analyzed, the anti-apoptotic gene Bcl-2 was down-regulated. Another interesting result observed was the up-regulation of the Apex- 1 gene after UV-B exposure, which could indicate the induction of oxidative lesions in the DNA molecule. In conclusion, these results demonstrate an activation of the DNA repair system in hepatocytes of zebrafish exposed to UV-B radiation, mainly involving the participation of p53. [source]


    Evaluation of Membrane Oxygenators and Reservoirs in Terms of Capturing Gaseous Microemboli and Pressure Drops

    ARTIFICIAL ORGANS, Issue 11 2009
    Yulong Guan
    Abstract An increasing amount of evidence points to cerebral embolization during cardiopulmonary bypass (CPB) as the principal etiologic factor of neurologic complications. In this study, the capability of capturing and classification of gaseous emboli and pressure drop of three different membrane oxygenators (Sorin Apex, Terumo Capiox SX25, Maquet QUADROX) were measured in a simulated adult model of CPB using a novel ultrasound detection and classification quantifier system. The circuit was primed with 1000 mL heparinized human packed red blood cells and 1000 mL lactated Ringer's solution (total volume 2000 mL, corrected hematocrit 26,28%). After the injection of 5 mL air into the venous line, an Emboli Detection and Classification Quantifier was used to simultaneously record microemboli counts at post-pump, post-oxygenator, and post-arterial filter sites. Trials were conducted at normothermic (35°C) and hypothermic (25°C) conditions. Pre-oxygenator and post-oxygenator pressure were recorded in real time and pressure drop was calculated. Maquet QUADROX membrane oxygenator has the lowest pressure drops compared to the other two oxygenators (P < 0.001). The comparison among the three oxygenators indicated better capability of capturing gaseous emboli with the Maquet QUADROX and Terumo Capiox SX25 membrane oxygenator and more emboli may pass through the Sorin Apex membrane oxygenator. Microemboli counts uniformly increased with hypothermic perfusion (25°C). Different types of oxygenators and reservoirs have different capability of capturing gaseous emboli and transmembrane pressure drop. Based on this investigation, Maquet QUADROX membrane oxygenator has the lowest pressure drop and better capability for capturing gaseous microemboli. [source]


    Accuracy of an electronic apex locator in primary teeth with root resorption

    INTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2009
    O. Angwaravong
    Abstract Aim, To evaluate whether root resorption of primary molar teeth affects the accuracy of the Root ZX apex locator and to compare the Root ZX at different meter readings with direct canal measurement. Methodology, Sixty extracted primary molar teeth with root resorption affecting one sixth to one third of root length were used. The teeth were embedded in an alginate model. A K-type file was used in association with a Root ZX apex locator to measure canal length. Measurements were recorded using the Root ZX meter reading ,Apex' and ,0.5 bar'. Actual tooth length was measured with a K-file to the major foramen. All measurements were read under a stereomicroscope at 15× magnification. The deviation of the Root ZX measurement from the actual canal length was determined. Results, Mean differences between Root ZX length meter reading ,Apex' and actual length were 0.01 ± 0.23 mm whereas mean differences between Root ZX length meter reading ,0.5 bar' and actual length were ,0.33 ± 0.30 mm. The Root ZX was 96.7% accurate to within ± 0.5 mm of the apical foramen when compared with the actual canal length of primary molars with root resorption. Conclusions, Using a criterion of ± 0.5 mm, the accuracy of the Root ZX was high and not affected by root resorption. When compared with direct canal measurement, the error in locating the apical foramen was smaller with measurement at meter reading ,Apex' than meter reading ,0.5 bar'. [source]


    Behavioural responses of the seven-spot ladybird Coccinella septempunctata to plant headspace chemicals collected from four crop Brassicas and Arabidopsis thaliana, infested with Myzus persicae

    AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2008
    R. D. Girling
    Abstract 1,Insects using olfactory stimuli to forage for prey/hosts are proposed to encounter a ,reliability,detectability problem', where the usability of a stimulus depends on its reliability as an indicator of herbivore presence and its detectability. 2,We investigated this theory using the responses of female seven-spot ladybirds Coccinella septempunctata (Coleoptera: Coccinellidae) to plant headspace chemicals collected from the peach-potato aphid Myzus persicae and four commercially available Brassica cultivars; Brassica rapa L. cultivar ,turnip purple top', Brassica juncea L. cultivar ,red giant mustard', Brassica napus L. cultivar ,Apex', Brassica napus L. cultivar ,Courage' and Arabidopsis thaliana. For each cultivar/species, responses to plants that were undamaged, previously infested by M. persicae and infested with M. persicae, were investigated using dual-choice Petri dish bioassays and circular arenas. 3,There was no evidence that ladybirds responded to headspace chemicals from aphids alone. Ladybirds significantly preferred headspace chemicals from B. napus cv. Apex that were undamaged compared with those from plants infested with aphids. For the other four species/cultivars, there was a consistent trend of the predators being recorded more often in the half of the Petri dish containing plant headspace chemicals from previously damaged and infested plants compared with those from undamaged ones. Furthermore, the mean distance ladybirds walked to reach aphid-infested A. thaliana was significantly shorter than to reach undamaged plants. These results suggest that aphid-induced plant chemicals could act as an arrestment or possibly an attractant stimulus to C. septempunctata. However, it is also possible that C. septempunctata could have been responding to aphid products, such as honeydew, transferred to the previously damaged and infested plants. 4,The results provide evidence to support the ,reliability,detectability' theory and suggest that the effectiveness of C. septempunctata as a natural enemy of aphids may be strongly affected by which species and cultivar of Brassica are being grown. [source]


    Blind Apexes and Scholarly Vision: Mark Twain Studies and The Art of HighPerformance Driving Or The Road Fast Traveled

    THE MARK TWAIN ANNUAL, Issue 1 2008
    MICHAEL J. KISKIS
    First page of article [source]


    Hsüa deflexa sp. nov. from the Xujiachong Formation (Lower Devonian) of eastern Yunnan, China

    BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2003
    DE-MING WANG
    A new vascular plant, Hsüa deflexa sp. nov., is documented from the Lower Devonian ((upper) Pragian-lower Emsian) Xujiachong Formation, near Xujiachong village, Qujing District, eastern Yunnan, South China. In three dimensions, the branching system comprises a robust creeping main axis and comparatively slender erect lateral axes inserted oppositely or alternately. The lateral axes depart at right angles from the main axis. Towards the apex, the main axis is perhaps erect with the lateral axes attached at smaller angles. The lateral axes dichotomize equally one to three times in different planes and decrease in diameter and length acropetally. They bear sparse and irregular tiny spines. Apices of a pair of distal lateral axes curve in opposite directions and each terminates in a rounded to reniform sporangium. The sporangium dehisces into two equal valves along an indistinct convex marginal thickening. The xylem is possibly centrarch. This plant fits Hsüa in branching pattern, sporangial characters and xylem maturation. Hsüa deflexa sp. nov. differs mainly from the type species H. robusta in the presence of axial spines, perpendicular extension of lateral axes from the main axis and curving of distal lateral axes. Based on the possibly centrarch xylem and terminal sporangium, this plant relates to the rhyniophytes (sensu Banks, 1968). In view of the equal sporangial valves with marginal thickenings it resembles the zosterophyllophytes (sensu Banks, 1968). Hsüa is now treated as incertae sedis. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 142, 255,271. [source]


    Large Apical Muscular Ventricular Septal Defect: Asymptomatic due to Anomalous Muscle Bundles in the Right Ventricle

    CONGENITAL HEART DISEASE, Issue 1 2007
    Anant Khositseth MD
    ABSTRACT This case report demonstrated an apical muscular ventricular septal defect (VSD) that was a large defect but behaved like a small defect because of the restrictive flow across the anomalous muscle bundles in the right ventricular (RV) apex. The anomalous muscle bundles separated the RV sinus into two parts: the RV apex connecting with the left ventricle through the apical muscular VSD on one side, and the rest of the RV sinus connecting with RV inflow and RV outflow on the other side. These findings explained why the 11-year-old girl in this study remained asymptomatic without evidence of volume load. Thus far, it was not necessary to close her defect because of the hemodynamic insignificance. [source]


    Dynamic compartmentalization of protein tyrosine phosphatase receptor Q at the proximal end of stereocilia: Implication of myosin VI-based transport

    CYTOSKELETON, Issue 7 2008
    Hirofumi Sakaguchi
    Abstract Hair cell stereocilia are apical membrane protrusions filled with uniformly polarized actin filament bundles. Protein tyrosine phosphatase receptor Q (PTPRQ), a membrane protein with extracellular fibronectin repeats has been shown to localize at the stereocilia base and the apical hair cell surface, and to be essential for stereocilia integrity. We analyzed the distribution of PTPRQ and a possible mechanism for its compartmentalization. Using immunofluorescence we demonstrate that PTPRQ is compartmentalized at the stereocilia base with a decaying gradient from base to apex. This distribution can be explained by a model of transport directed toward the stereocilia base, which counteracts diffusion of the molecules. By mathematical analysis, we show that this counter transport is consistent with the minus end-directed movement of myosin VI along the stereocilia actin filaments. Myosin VI is localized at the stereocilia base, and exogenously expressed myosin VI and PTPRQ colocalize in the perinuclear endosomes in COS-7 cells. In myosin VI-deficient mice, PTPRQ is distributed along the entire stereocilia. PTPRQ-deficient mice show a pattern of stereocilia disruption that is similar to that reported in myosin VI-deficient mice, where the predominant features are loss of tapered base, and fusion of adjacent stereocilia. Thin section and freeze-etching electron microscopy showed that localization of PTPRQ coincides with the presence of a dense cell surface coat. Our results suggest that PTPRQ and myosin VI form a complex that dynamically maintains the organization of the cell surface coat at the stereocilia base and helps maintain the structure of the overall stereocilia bundle. Cell Motil. Cytoskeleton 2008. Published 2008 Wiley-Liss, Inc. [source]


    A subclass of myosin XI is associated with mitochondria, plastids, and the molecular chaperone subunit TCP-1, in maize

    CYTOSKELETON, Issue 4 2004
    Zhengyuan Wang
    Abstract The role and regulation of specific plant myosins in cyclosis is not well understood. In the present report, an affinity-purified antibody generated against a conserved tail region of some class XI plant myosin isoforms was used for biochemical and immunofluorescence studies of Zea mays. Myosin XI co-localized with plastids and mitochondria but not with nuclei, the Golgi apparatus, endoplasmic reticulum, or peroxisomes. This suggests that myosin XI is involved in the motility of specific organelles. Myosin XI was more than 50% co-localized with tailless complex polypeptide-1, (TCP-1,) in tissue sections of mature tissues located more than 1.0 mm from the apex, and the two proteins co-eluted from gel filtration and ion exchange columns. On Western blots, TCP-1, isoforms showed a developmental shift from the youngest 5.0 mm of the root to more mature regions that were more than 10.0 mm from the apex. This developmental shift coincided with a higher percentage of myosin XI /TCP-1, co-localization, and faster degradation of myosin XI by serine protease. Our results suggest that class XI plant myosin requires TCP-1, for regulating folding or providing protection against denaturation. Cell Motil. Cytoskeleton 57:218,232, 2004. © 2004 Wiley-Liss, Inc. [source]


    Dilaceration of maxillary central incisor: a literature review

    DENTAL TRAUMATOLOGY, Issue 5 2010
    Nikolaos Topouzelis
    In early developmental stages, the permanent tooth germ of the maxillary incisor is situated palatally and superiorly to the apex of the primary incisor and gradually changes direction in a labial direction with its crown coming closer to the resorbing primary root. For reasons of this close relationship between the permanent tooth germ and the apex of the primary incisor, it is believed that an acute trauma to the primary predecessor can cause dilaceration of the long axis of the permanent successor. Clinically, dilaceration can be revealed by palpation high in the labial sulcus or in the hard palate, while its radiographic view is characteristic. The therapeutic approach to the dilacerated maxillary central incisors has to be carefully planned and needs the cooperation of several specialities to attain the final objective. [source]


    pH changes in external root surface cavities after calcium hydroxide is placed at 1, 3 and 5 mm short of the radiographic apex

    DENTAL TRAUMATOLOGY, Issue 5 2009
    Thaddeus M. Chamberlain
    The root canals of single-rooted anterior human teeth were cleaned and shaped after decoronation. Cavities about 0.50 mm deep and 1.0 mm wide located at 1, 3 and 5 mm from the radiographic apex were prepared on the external root surface and the teeth were randomly divided into four groups. The roots were filled with calcium hydroxide at 1, 3 and 5 mm from the radiographic apex, and the control group was left empty. pH readings were obtained at intervals over a 28-day study. The roots which were filled within 1 mm of the radiographic apex had the greatest increase in pH in each of the cavities. These results demonstrate that the greatest pH change on the external root surface near the apex is obtained when the canal is more completely filled with calcium hydroxide. [source]


    Pulp and periodontal healing of laterally luxated permanent teeth: results after 4 years

    DENTAL TRAUMATOLOGY, Issue 6 2008
    Elena C. Ferrazzini Pozzi
    Material and methods:, Patients presenting with lateral luxation of permanent teeth during 2001,2002 were enrolled in this clinical study. Laterally luxated teeth were repositioned and splinted with a TTS/composite resin splint for 4 weeks. Immediate (prophylactic) root-canal treatment was performed in severely luxated teeth with radiographically closed apices. All patients received tetracycline for 10 days. Re-examinations were performed after 1, 2, 3, 6, 12 and 48 months. Results:, All 47 laterally luxated permanent teeth that could be followed over the entire study period survived. In 10 teeth (21.3%), a prophylactic root-canal treatment was performed within 2 weeks following injury. The remaining 37 teeth showed the following characteristics at the 4-year re-examination: 19 teeth (51.4%) had pulp survival (no clinical or radiographic signs or symptoms), nine teeth (24.3%) presented with pulp canal calcification, and pulp necrosis was seen in another nine teeth (24.3%), within the first year after trauma. None of the teeth with a radiographically open apex at the time of lateral luxation showed complications. External root resorption was only seen in one tooth. Conclusions:, Laterally luxated permanent teeth with incomplete root formation have a good prognosis, with all teeth surviving in this study. The most frequent complication was pulp necrosis that was only seen in teeth with closed apices. [source]


    An unusual lateral luxation of an upper incisor owing to long-term boxing without protection

    DENTAL TRAUMATOLOGY, Issue 5 2008
    Ron Bechor
    The tooth displacement gradually worsened over several months because the boxer received repeated blows to the head without using a mouthguard. Being a chronic dental trauma, rather than an acute lateral luxation, this case had several unique features: the labial plate of the alveolar bone was penetrated, the root apex was free in the vestibulum, the tooth was mobile (second degree) and radiographs revealed bone resorption. This case emphasized the need for a mouthguard to be used even with amateur boxing. The dental practitioner should educate his sportsmen,patients of the risk of sport-related dental trauma and the benefit of a mouthguard. [source]


    Comparative in vitro study of the sealing efficiency of white vs grey ProRoot mineral trioxide aggregate formulas as apical barriers

    DENTAL TRAUMATOLOGY, Issue 2 2008
    Spyridon Stefopoulos
    Recently conventional grey MTA has been replaced by a new white MTA formula. The aim of this study was to compare the root canal adaptation of white MTA to that of grey MTA when used as an apical barrier in teeth with open apices. We also examined whether a previous calcium hydroxide intracanal medication affects MTA's sealing ability and investigated the ability to remove calcium hydroxide from the root canal walls. Forty-nine teeth were prepared in a manner to simulate a divergent open apex of immature teeth. Four teeth were used in a preliminary experiment to demonstrate the inefficacy of calcium hydroxide removal from the canal walls in teeth with open apices. Four groups of 10 teeth each were created: groups A and B were treated with calcium hydroxide intracanal medication and then received an apical plug of grey and white MTA respectively. Groups C and D received an apical plug of grey and white MTA respectively without previous intracanal medication. Four teeth served as negative and one as a positive control. The marginal adaptation and sealing ability of the apical barrier were tested by means of a dye tracer (basic fuchsine) after longitudinal sectioning. It was found that MTA apical barrier resisted displacement during gutta-percha condensation. Calcium hydroxide pretreatment, adversely affected white MTA sealing ability (P < 0.05). [source]


    Reattachment of subgingivally fractured central incisor with an open apex

    DENTAL TRAUMATOLOGY, Issue 3 2007
    Ece Eden
    Abstract,,, A case report of a 6-year-old girl with a fractured maxillary left central incisor with an open apex is presented. The procedure used to repair the fracture included flap surgery with an intrasulcular incision and endodontic treatment. The patient was called for 3 months regular follow-up to check the root formation. At the end of 32 months just before the root was obturated by guttaperka, she fractured the same tooth. Flap surgery was repeated and the tooth was restored. The root canal was obturated with a root filling paste and guttaperka as the apex was closed. Examination 10 months after treatment revealed good periodontal health, aesthetics and normal function. [source]


    Factors affecting treatment outcomes following complicated crown fractures managed in primary and secondary care

    DENTAL TRAUMATOLOGY, Issue 4 2006
    N. G. Jackson
    Abstract,,, The aims of this retrospective observational study were to determine the factors which affect treatment provision and the Median Survival Time (MST) for maintenance of tooth vitality following complicated crown fracture. The survey was carried out for patients treated at Newcastle Dental Hospital (NDH) according to departmental guidelines over a 2-year period following the introduction of a new protocol for management of these types of injuries. Seventy-three cases of complicated crown fracture were identified in 69 children with a mean age of 10.3 years (SD = 2.5 years). Seventy-one percent of the fractures occurred in males (M:F ratio was 2.5:1). Fifty-one percent of the complicated crown fractures were in immature teeth. Of the 73 traumatised teeth, 45% presented initially in general dental practice (GDP), 37% at the dental hospital and 8% at local accident and emergency departments with the remaining 10% seen at other or unrecorded locations. Of the 41 fractures, which presented initially at a location other than the dental hospital, 38% were referred to the dental hospital without the provision of an emergency pulp bandage. The overall definitive treatments provided for the 37 open apex teeth included pulp cap (19%), partial pulpotomy (32%), cervical pulpotomy (8%) and pulpectomy (35%), while for the 36 closed apex teeth it was pulp cap (28%), pulpotomy (11%), and pulpectomy (61%). Of the 30 teeth, which underwent vital pulp therapy (18 open and 12 closed apex), the MST for the 15 teeth treated with pulp caps was 1460 days (95% CI: 1067, 1853) while for the 15 teeth treated with pulpotomies it was 1375 days (95% CI: 964, 1786). There was no statistically significant difference in the MST between teeth treated with pulp caps and pulpotomies. In conclusion, the proportion of patients referred to secondary care with complicated crown fractures without provision of a pulp bandage is of some concern. More conservative treatment of closed apex teeth sustaining complicated crown fractures, utilizing vital pulp therapy techniques would appear to be appropriate. [source]


    Naturally Occurring Female Hairline Patterns

    DERMATOLOGIC SURGERY, Issue 6 2009
    BERNARD P. NUSBAUM MD
    BACKGROUND Hair transplantation is gaining popularity in women. Although much has been written about hairline design in male patients, more information is needed about natural female hairlines. OBJECTIVE To determine the frequency, dimensions, and location of structures that compose the female hairline. METHODS Hairline characteristics were measured in 360 female volunteers at an informal hair salon setting. RESULTS A widow's peak was present in 81%. The mean distance from the mid-eyebrow to the frontal midpoint was 5.5 cm. Lateral mounds were observed in 98%. The mean distance from the frontal midpoint to the apex of the lateral mounds was 3.74 cm on the right and 3.97 cm on the left. The mean distance from the apex of the lateral mounds to the apex of the temporal points was 3.78 cm on the right and 3.51 cm on the left. The shape of the temporal recessions was concave triangular or concave oval in 87% of the subjects. CONCLUSION This study provides proposed guidelines for designing the hairline in women. [source]


    Development of lymphatic vessels in mouse embryonic and early postnatal hearts

    DEVELOPMENTAL DYNAMICS, Issue 10 2008
    Juszy, Micha
    Abstract We aimed to study the spatiotemporal pattern of lymphatic system formation in the embryonic and early postnatal mouse hearts. The first sign of the development of lymphatics are Lyve-1,positive cells located on the subepicardial area. Strands of Lyve-1,positive cells occur first along the atrioventricular sulcus of the diaphragmatic surface and then along the great arteries. Lumenized tubules appear, arranged in rows or in a lattice. They are more conspicuous in dorsal atrioventricular junction, along the major venous and coronary artery branches and at the base of the aorta and the pulmonary trunk extending toward the heart apex. At later stages, some segments of the lymphatic vessels are partially surrounded by smooth muscle cells. Possible mechanisms of lymphangiogenesis are: addition of Lyve-1,positive cells to the existing tubules, elongation of the lymphatic lattice, sprouting and coalescence of tubules. We discuss the existence of various subpopulations of endothelial cells among the Lyve-1,positive cells. Developmental Dynamics 237:2973,2986, 2008. © 2008 Wiley-Liss, Inc. [source]


    Sensillary morphology on the rostral apex and their possible role in prey location behaviour of the carnivorous stinkbug, Eocanthecona furcellata (Wolff) (Heteroptera: Pentatomidae)

    ACTA ZOOLOGICA, Issue 3 2009
    Pathipati Usha Rani
    Abstract Eocanthecona furcellata (Wolff), the carnivorous heteropteran, demonstrates interesting feeding mechanisms that suggest the involvement of the antennal and labial tip sensilla. This study was conducted to identify the morphology of various sensilla present on the labial tip of this insect using scanning electron microscopy. Four morphologically different types of trichoid sensilla comprise the largest and most numerous sensilla and occur throughout the surface of the labial tip. Three new and unique types of sensilla were discovered. Long hairs with profusely branched shafts are present at the entrance of the rostral groove. An oval-shaped peg surrounded by sensory hairs with branched shafts and a short, stout peg encircled by a group of long hair-like sensilla was found among the sensilla population of two lobes. The morphology of the new sensilla is given and possible functions of individual receptors are suggested on morphological grounds. [source]


    Morphometric controls and geomorphic responses on fans in the Southern Alps, New Zealand

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2004
    Fes A. de Scally
    Abstract Morphometric variables associated with 41 debris-,ow and 18 ,uvial fans and their basins in the Southern Alps of New Zealand are examined. The results show statistically signi,cant differences in the area, maximum elevation, relief and ruggedness (Melton's R) of the basin and the area, gradient, and apex and toe elevations of the fan between debris-,ow and ,uvial sites. Concavity of the fan longitudinal pro,le also differs between the two fan types, although this could not be tested statistically. Most of these morphometric differences re,ect differences in processes and environmental controls on them. Discriminant analysis indicates that basin area and fan gradient best differentiate the two fan types by process. Moderately strong correlations exist, on both debris-,ow and ,uvial fans, between basin area or Melton's R and fan area. Correlations between basin area or Melton's R and fan gradient are generally weaker. The results of this study also indicate that on debris-,ow-prone fans the fan gradient and basin Melton's R have lower thresholds which overlap little with upper thresholds associated with basins where only stream,ow reaches the fan. These thresholds may therefore have value in preliminary morphometric assessments of debris-,ow hazard on fans in the Southern Alps. Copyright © 2004 John Wiley & Sons, Ltd. [source]