Duct

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Duct

  • bile duct
  • biliary duct
  • collecting duct
  • common bile duct
  • common hepatic duct
  • cystic duct
  • eccrine duct
  • efferent duct
  • ejaculatory duct
  • endolymphatic duct
  • excretory duct
  • extrahepatic bile duct
  • genital duct
  • gland duct
  • hepatic duct
  • intrahepatic bile duct
  • lower common bile duct
  • main excretory duct
  • main pancreatic duct
  • müllerian duct
  • nasolacrimal duct
  • pancreatic duct
  • salivary duct
  • square duct
  • striated duct
  • thoracic duct
  • wolffian duct

  • Terms modified by Duct

  • duct cancer
  • duct cannulation
  • duct carcinoma
  • duct cell
  • duct cyst
  • duct damage
  • duct diameter
  • duct dilatation
  • duct epithelial cell
  • duct epithelium
  • duct exploration
  • duct formation
  • duct hyperplasia
  • duct injury
  • duct invasion
  • duct lesion
  • duct ligation
  • duct obstruction
  • duct occluder
  • duct orifice
  • duct resection
  • duct stone
  • duct stricture
  • duct syndrome
  • duct system
  • duct unit
  • duct wall

  • Selected Abstracts


    ENDOSCOPIC OCCLUSION OF CYSTIC DUCT USING N -BUTYL CYANOACRYLATE FOR POSTOPERATIVE BILE LEAKAGE

    DIGESTIVE ENDOSCOPY, Issue 4 2010
    Eric K. Ganguly
    Bile leak after cholecystectomy is well described, with the cystic duct remnant the site of the leak in the majority of cases. Endoscopic retrograde cholangiopancreatography (ERCP) with biliary stent placement has a high success rate in such cases. When ERCP fails, options include surgery, and percutaneous and endoscopic transcatheter occlusion of the site of bile leak. Here, we describe a case of endoscopic transcatheter occlusion of a persistent cystic duct bile leak after cholecystectomy using N -butyl cyanoacrylate glue. A 51-year-old man had persistent pain and bilious drainage following a laparoscopic cholecystectomy. The bile leak persisted after endoscopic placement of a biliary stent for a confirmed cystic duct leak. A repeat ERCP was carried out and the cystic duct was occluded with a combination of angiographic coils and N -butyl cyanoacrylate glue. The patient's pain and bilious drainage resolved. A follow-up cholangiogram confirmed complete resolution of the cystic duct leak and a patent common bile duct. [source]


    TEACHING DEEP CANNULATION OF THE BILE DUCT DURING ENDOSCOPIC RETROGRADE CHOLANGIOGRAPHY

    DIGESTIVE ENDOSCOPY, Issue 4 2007
    Kiichi Tamada
    When performing endoscopic retrograde cholangiopancreatography (ERCP), the smooth introduction of the duodenoscope into the papilla of Vater, an appropriate view of the papilla of Vater, and deep cannulation of the bile duct are essential. The operator must know the difference between the side-viewing endoscope and the forward-viewing endoscope. The rotation of the body and the left arm of the operator, switching with the left wrist, and dialing of the endoscope are essential for appropriately viewing the papilla of Vater. When training operators to do ERCP, a model is useful for helping them understand basic handling. The approach to deep cannulation of the bile duct should be selected based on the type of papilla (slit type, onion type, tongue protrusion type, flat type, and tumor type). Cannulation is more difficult in patients with the tongue protrusion-type of papilla than with a slit type, onion type, or tumor type. According to previous reports, therapeutic ERCP requires the ability to cannulate the common bile duct deeply 80% of the time; 180 to 200 supervised ERCP are necessary to achieve this success rate. [source]


    Clinical and Pathological Findings in Testis, Epididymis, Deferens Duct and Prostate following Vasectomy in a Dog

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2006
    CC Pérez-Marín
    Contents We report the case of a bilateral and multilocular spermatocele and sperm granuloma in a dog that was vasectomized 5 years before. Clinical examination revealed scrotal dermatitis and benign prostatic hyperplasia. Orchiectomy was performed, and gross and histological examination showed testicular degeneration associated with epididymal sperm granuloma. In relation to this case, the literature about long-term effects of vasectomy in dogs has been reviewed. On the basis of these results, a preventive sonogram and physical assessment in prostate and other reproductive structures before vasectomy is recommended. [source]


    Onset of Apoptosis in the Cystic Duct During Metamorphosis of a Japanese Lamprey, Lethenteron reissneri

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 7 2010
    Mayako Morii
    Abstract A nonparasitic lamprey in Japan, Lethenteron reissneri, stops feeding prior to the commencement of metamorphosis. Resumption of feeding cannot take place due to major alterations in the digestive system, including loss of the gall bladder (GB) and biliary tree in the liver. This degeneration of bile ducts is considered to depend on programmed cell death or apoptosis, but molecular evidence of apoptosis remains lacking. Using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and immunohistochemistry with an antibody against active caspase-3, we showed that epithelial cells of the cystic duct (CD) and GB became TUNEL-positive by the early metamorphosing stage. Immunohistochemical staining of active caspase-3, a key mediator in the apoptotic cascade, showed that the apoptotic signal was initiated in the region around the CD in the late larval phase. In later stages, active caspase-3-positive epithelial cells were also observed in the large intrahepatic bile duct (IHBD) and peripheral small IHBDs. At the early metamorphosing stage, bile canaliculi between hepatocytes were dilated and displayed features resembling canaliculi in cholestasis. Onset of apoptosis around the CD, which is the pathway for the storage of bile juice, and progression of apoptosis towards the large IHBD, which is the pathway for the secretion of bile juice, may lead to temporary intrahepatic cholestasis. The present study represents the first precise spatial and temporal analysis of apoptosis in epithelial cells of the biliary tract system during metamorphosis of any lamprey species. Anat Rec 293:1155,1166, 2010. © 2010 Wiley-Liss, Inc. [source]


    Expression and Distribution of Intermediate-filament Proteins and Laminin during the Development of the Bovine Müllerian Duct

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2008
    R. A.-M.
    Summary The expression pattern of several intermediate-filament proteins (vimentin, cytokeratin 8, 18 and19) and the basal lamina component laminin was investigated in the Wolffian and the Müllerian ducts of bovine embryos and fetuses. The material studied comprised sexually undifferentiated stages [crown-rump length (CRL) 0.9 cm/1.0 cm/1.2 cm/1.9 cm/2.5 cm] and female stages (CRL 3.0 cm/4.2 cm/5.1 cm). Laminin could be demonstrated in the basal lamina of the developing Wolffian and Müllerian duct as well as in the stroma surrounding the Müllerian duct. The intermediate-filament protein vimentin was expressed in the mesothelium of the funnel field and in the epithelium of the Müllerian duct in all studied specimens, whereas the epithelial cells of the Wolffian duct only showed vimentin expression from a CRL of 2.2 cm onwards. In the cranial part of the Müllerian ducts only a few cells stained with pan-cytokeratin antibodies, whereas mesothelium and epithelium of the Wolffian duct showed as distinct immunostaining in all investigated stages. Both genital ducts showed no immunostaining with the antibody against cytokeratin 19 at any time of development. We conclude from our immunohistochemical results that the epithelial cells of the Wollfian duct do not contribute cells to the developing Müllerian duct. [source]


    A New Look on the Origin of the Gonad and the Müllerian Duct: the Sturgeon (Acipencer) as a Model for Vertebrate Urogenital Development

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005
    K. -H.
    The origin of the vertebrate gonad and the Müllerian duct are still a matter of debate. According to the majority of recent textbooks, the gonad is a product of the proliferating coelothelium and therefore derived from the mesoderm of the lateral plate region. The Müllerian duct grows parallel to the Wolffian duct, but it is not clear to what extent the latter contributes actively to the development of the former. In the last decade, we reinvestigated early gonadogenesis and Müllerian duct development in a number of vertebrate model species using various morphological techniques (TEM, SEM, immunohistochemistry). The conclusion of our studies is that rudimentary or regressing nephrostomial tubules, particularly cells of their nephrostomes, must be regarded as the immediate precursors of the somatic cells of the gonadal crest and the Müllerian infundibular field. According to this concept, both structures are derivatives of the intermediate mesoderm. Nephrostomial tubules are regular components of the primitive pro- and mesonephros. They connect the nephric tubule or the nephric corpuscle to the coelomic cavity and open into the latter by means of a funnel-like mouth, the nephrostome (coelomostome). In the larval sterlet, Acipenser ruthenus, short, segmentally arranged nephrostomial tubules with well-developed nephrostomes are present in the region of the cranial opisthonephros. Cells of the medial nephrostomial lips proliferate, surround the germ cells that have accumulated in this location and form a continuous gonadal crest. Cells of the lateral nephrostomial lips proliferate also, spread out on the coelomic surface, replace the original flat mesothelial cells over the Wolffian duct and the cranial opisthonephros and form the Müllerian infundibular field. At about 28 days, a flat pocket begins to invaginate the infundibular field. This pocket is the primordium of the Müllerian ostium abdominale. The findings in Acipenser can be generalized and transferred to other vertebrates. [source]


    Modification of epithelial cell barrier permeability and intercellular junctions by Clostridium sordellii lethal toxins

    CELLULAR MICROBIOLOGY, Issue 7 2006
    Catherine Boehm
    Summary Clostridium sordellii lethal toxin (LT) is a glucosyltransferase which inactivates small GTPases from the Rho and Ras families. In the present work, we studied the effects of two variants, LT82 and LT9048, on the integrity of epithelial cell barrier using polarized MCCD (Mouse Cortical Collecting Duct) and MDCK (Madin-Darby Canine Kidney) cells. Our results demonstrate for the first time that LTs have very limited effects on tight junctions. In contrast, we show that both toxins modified the paracellular permeability within 2,4 h. Concomitantly LT82 and LT9048 induced a disorganization of basolateral actin filaments, without modifying apical actin. Both toxins mainly altered adherens junctions by removing E-cadherin-catenin complexes from the membrane to the cytosol. Similar effects on adherens junctions have been observed with other toxins, which directly or indirectly depolymerize actin. Thereby, Rac, a common substrate of both LTs, might play a central role in LT-dependent adherens junction alteration. Here, we show that adherens junction perturbation induced by LTs results neither from a direct effect of toxins on adherens junction proteins nor from an actin-independent Rac pathway, but rather from a Rac-dependent disorganization of basolateral actin cytoskeleton. This further supports that a dynamic equilibrium of cortical actin filaments is essential for functional E-cadherin organization in epithelia. [source]


    Anatomy of the lactating human breast redefined with ultrasound imaging

    JOURNAL OF ANATOMY, Issue 6 2005
    D. T. Ramsay
    Abstract The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast. The breasts of 21 fully lactating women (1,6 months post partum) were scanned using an ACUSON XP10 (5,10 MHz linear array probe). The number of main ducts was measured, ductal morphology was determined, and the distribution of glandular and adipose tissue was recorded. Milk ducts appeared as hypoechoic tubular structures with echogenic walls that often contained echoes. Ducts were easily compressed and did not display typical sinuses. All ducts branched within the areolar radius, the first branch occurring 8.0 ± 5.5 mm from the nipple. Duct diameter was 1.9 ± 0.6 mm, 2.0 ± 90.7 mm and the number of main ducts was 9.6 ± 2.9, 9.2 ± 2.9, for left and right breast, respectively. Milk ducts are superficial, easily compressible and echoes within the duct represent fat globules in breastmilk. The low number and size of the ducts, the rapid branching under the areola and the absence of sinuses suggest that ducts transport breastmilk, rather than store it. The distribution of adipose and glandular tissue showed wide variation between women but not between breasts within women. The proportion of glandular and fat tissue and the number and size of ducts were not related to milk production. This study highlights inconsistencies in anatomical literature that impact on breast physiology, breastfeeding management and ultrasound assessment. [source]


    Atypical Fetal Prostate Development is Associated with Ipsilateral Hypoplasia of the Wolffian Ducts in the ACI Rat

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 5 2010
    Luke E. Hofkamp
    Abstract For over a half century, the ACI (August × Copenhagen) rat has been a primary model for studying renal agenesis and ipsilateral hypoplasia (IHP) of the Wolffian-derived structures (WDS). Because the ACI rat is also used as a model for prostate research, it is important to examine the relationship of IHP and urogenital sinus (UGS) development. The prostate is dependent on androgens for proper growth and differentiation. Alteration in androgen production and/or delivery to the UGS has the potential to perturbate normal development. In this study, we investigate whether the ipsilateral loss of the WDS is associated with altered prostate development. Digital images of serial-sectioned fetal ACI rat UGS were used to create three-dimensional (3-D) surface-rendered models of the developing prostate, seminal vesicle, vas deferens, and utricle on gestational day 21. The number and volume of prostate ducts developing from the UGS were calculated from the 3-D model data. Animals exhibiting IHP had a significant decrease in total fetal prostate volume (40%; P < 0.005) with significant regional specific differences when compared with normal male ACI rats. Anatomical and histological differences in the utricle, abnormal histology of the ipsilateral testes, and a truncation of the ipsilateral Wolffian ductal mesenchyme were also seen in the animals with IHP. Additional research is needed to further understand the mechanisms and consequences of IHP on prostate growth and development. Alterations to normal prenatal development of the male accessory sex organs can have important consequences for the growth and morphology of the adult gland. Anat Rec, 2010. © 2010 Wiley-Liss, Inc. [source]


    Atypical Fetal Prostate Development is Associated with Ipsilateral Hypoplasia of the Wolffian Ducts in the ACI Rat

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 5 2010
    Luke E. Hofkamp
    Serial section reconstruction images of the male ACI rat urogenital sinus shown from a dorso-cranial view. The image in the lower right illustrates the normal late gestation appearance of the accessory gland development, compared to the Wolffian duct ipsilateral abnormality observed in 25% of the male offspring (upper left). See Potok et al., Anatomical Record 239:747,753. [source]


    A Technical Improvement in Sialendoscopy to Enter the Salivary Ducts

    THE LARYNGOSCOPE, Issue 5 2006
    Cyrille Chossegros MD
    No abstract is available for this article. [source]


    Laparoscopic Cholecystectomy Of A Bifid Gall Bladder With Two Separate Cystic Ducts

    ANZ JOURNAL OF SURGERY, Issue 8 2000
    Koroush S. Haghighi
    No abstract is available for this article. [source]


    Mixing in Sub-micron Ducts

    CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2004
    E.B. Nauman
    Abstract This paper considers a class of fluidic devices, anticipated to become important in the near future, where characteristic channel dimensions are in the range 0.1 to 1.0 microns. Typical current applications of microfluidics have device sizes of 10 to 100 micron, this is sufficiently small to force laminar flow but not so small that molecular diffusion is a dominant factor. In the smaller devices contemplated here, diffusion is important and existing mixing strategies and correlations are no longer applicable. Novel results and interesting complexities are discussed for reactive, single and two phase flows in sub-micron channels. [source]


    Patent ductus arteriosus and cystic periventricular leucomalacia in preterm infants

    ACTA PAEDIATRICA, Issue 3 2001
    P Pladys
    Aim: To test the association between early disturbances in hemodynamics induced by left-to-right shunting through the duct and cystic periventricular leucomalacia. Patients: Forty-six preterm infants (27,32 wk) admitted to the neonatal intensive care unit with risk criteria. Methods: Patent ductus arteriosus was evaluated on days 1 and 4, and was significant (sPDA) in cases of absent or reversed end diastolic flow in the subductal aorta. Resistance index was measured in the anterior cerebral artery and in the subductal aorta. Main outcome: Diagnosis of cystic periventricular leucomalacia between day 10 and day 50. Results: The 12 infants who developed cystic periventricular leucomalacia were compared with those who did not. On day 1, sPDA was more frequent (64% vs 26%; p= 0.03) in the cystic periventricular leucomalacia group, left ventricular output was higher (median = 341 vs 279mlkg -1.min -1; p= 0.005), and rescue surfactant was more frequently used (83% vs 47%; p= 0.03). This latter association was confirmed by multivariate analysis. Resistance index in the anterior cerebral artery was increased in cases of significant patent ductus arteriosus (p < 0.01) and was correlated with resistance index in the subductal aorta. Conclusion: On day 1 in this selected population, sPDA has an effect on blood flow velocity waveform in cerebral arteries and is associated with an increase in the emergence of cystic periventricular leucomalacia. This association could be casual rather than causal. [source]


    The solution of fluid mechanics problems by probability methods

    COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 2 2005
    Sergio E. Perez
    Abstract This study shows how fluid mechanics problems may be solved using probability methods. Problems solved include velocity distributions in steady and unsteady flow between parallel plates as well as steady flow through a constant diameter three-dimensional duct. We find that the results approach exact solutions as the number of random walks increases, and that the complexity of the flow equations precludes extension of the technique to three dimensions. We also find that these techniques are much easier for students to put into practice than others. © 2005 Wiley Periodicals, Inc. Comput Appl Eng Educ 13: 133,136, 2005; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20038 [source]


    EndothelinA (ETA) and ETB receptor-mediated regulation of nitric oxide synthase 1 (NOS1) and NOS3 isoforms in the renal inner medulla

    ACTA PHYSIOLOGICA, Issue 4 2007
    J. C. Sullivan
    Abstract Aim:, Our laboratory and others have shown that endothelin (ET)-1 directly stimulates nitric oxide (NO) production in inner medullary collecting duct (IMCD) cells. The goal of this study was to determine which NO synthase (NOS) isoforms in IMCD are sensitive to ET-1, and the role of ETA and ETB receptor activation in vivo and in vitro. Methods:, NOS enzymatic activity and NOS isoform protein expression were examined in cultured IMCD-3 cells and isolated renal inner medulla. ETB receptor-deficient homozygous rats (sl/sl) have elevated levels of circulating ET-1 and lack a functional ETB signalling pathway in kidneys, and furthermore provides a unique model to study ETA receptor signalling in the renal inner medulla in vivo. Results:, Incubation of IMCD-3 cells with exogenous ET-1 (50 nm) resulted in ETA -dependent increased NOS1 protein expression in IMCD-3 cells with no effect on NOS2 or NOS3 expression. ETB receptor antagonism has no effect on NOS expression in IMCD-3 cells. Consistent with in vitro results, cytosolic NOS1 protein expression was significantly greater in the renal inner medulla of sl/sl rats compared with heterozygous (sl/+) controls, with no alteration in NOS3 expression. In contrast to protein expression data, NOS1- and NOS3-specific enzymatic activities decreased in the cytosolic fraction from the renal inner medulla of sl/sl compared with sl/+. Conclusion:, These results provide evidence that both ETA and ETB receptors regulate NOS isoform activity in the renal inner medulla and specifically support the hypothesis that ETA receptor activation increases NOS1 expression. [source]


    New method for evaluation of lung lymph flow rate with intact lymphatics in anaesthetized sheep

    ACTA PHYSIOLOGICA, Issue 2 2006
    T. Naito
    Abstract Aim:, Lung lymph has commonly been studied using a lymph fistula created by tube cannulation into the efferent duct of the caudal mediastinal node in sheep. In this method, the tail region of the caudal mediastinal node is resected and the diaphragm is cauterized to exclude systemic lymph contamination, and cannulation is performed into one of the multiple efferent ducts originating from the caudal mediastinal node. Moreover, the pumping activity of lymphatics might be diminished by cannulation. Therefore, the purpose of the study was to evaluate the flow rate of lung lymph with maintenance of intact lymphatic networks around the caudal mediastinal node to the thoracic duct in sheep. Methods:, An ultrasound transit-time flow meter was used to measure lung lymph flow. The thoracic duct was clamped just above the diaphragm and the flow probe was attached to the thoracic duct just after the last junction with an efferent duct from the caudal mediastinal node. The lung lymph flow rate was measured at baseline and under conditions of lung-oedema formation. Results:, The baseline lung lymph flow rate in our model was three- to sixfold greater than values obtained with the cannulation method. With oedema-formation, the lung lymph flow rate was the same as that measured using cannulation. Conclusion:, The lung lymph flow was unexpectedly large under the conditions of the study, and our data suggest that the drainage effect of lymphatics is significant as a safety factor against pulmonary oedema formation. [source]


    Dan is required for normal morphogenesis and patterning in the developing chick inner ear

    DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2007
    Takahiro Yamanishi
    During vertebrate inner ear development, compartmentalization of the auditory and vestibular apparatuses along two axes depends on the patterning of transcription factors expressed in a region-specific manner. Although most of the patterning is regulated by extrinsic signals, it is not known how Nkx5.1 and Msx1 are patterned. We focus on Dan, the founding member of the Cerberus/Dan gene family that encodes BMP antagonists, and describe its function in morphogenesis and patterning. First, we confirmed that Dan is expressed in the dorso-medial region of the otic vesicle that corresponds to the presumptive endolymphatic duct and sac (ed/es). Second, we used siRNA knockdown to demonstrate that depletion of Dan induced both a severe reduction in the size of the ed/es and moderate deformities of the semicircular canals and cochlear duct. Depletion of Dan also caused suppression of Nkx5.1 in the dorso-lateral region, suppression of Msx1 in the dorso-medial region, and ectopic induction of Nkx5.1 and Msx1 in the ventro-medial region. Most of these phenotypes also appeared following misexpression of the constitutively active form of BMP receptor type Ib. Thus, Dan is required for the normal morphogenesis of the inner ear and, by inhibiting BMP signaling, for the patterning of the transcription factors Nkx5.1 and Msx1. [source]


    Staying alive: Dalmatian mediated blocking of apoptosis is essential for tissue maintenance

    DEVELOPMENTAL DYNAMICS, Issue 6 2010
    Bilal E. Kerman
    Abstract In an EMS screen for mutations disrupting tracheal development, we identified new alleles of the dalmation (dmt) gene, which had previously been shown to affect peripheral nervous system (PNS) development. Here, we demonstrate that dmt loss results in programmed cell death, disrupting PNS patterning and leading to large gaps in the salivary duct and trachea. Dmt loss results in increased expression of the proapoptotic regulator genes head involution defective (hid) and reaper (rpr), and deletion of these genes or tissue-specific expression of the baculoviral apoptotic inhibitor P35 rescues the dmt defects. dmt is also required to protect cells from irradiation induced expression of hid and rpr during the irradiation resistant stage, which begins as cells become irreversibly committed to their final fates. Thus, we propose that Dmt keeps cells alive by blocking activation of hid and rpr as cells become irreversibly committed. Developmental Dynamics 239:1609,1621, 2010. © 2010 Wiley-Liss, Inc. [source]


    The embryonic expression patterns and the knockdown phenotypes of zebrafish ADP-ribosylation factor-like 6 interacting protein gene

    DEVELOPMENTAL DYNAMICS, Issue 1 2009
    Hsing-Yen Huang
    Abstract ADP-ribosylation factor-like 6 (Arl6) mutation is linked to human disease and Arl6 interacts with Arl6 interacting protein (Arl6ip). However, the expression pattern and function of Arl6ip during embryogenesis are unknown. To confirm whether abnormal Arl6ip function might result in embryonic defects in zebrafish, we examined the expression patterns of arl6ip during embryogenesis, and they were maternally expressed and exhibited in the brain, optic primordia, hypochord, spinal cord, myotome, heart, fin-bud, kidney, trunk, and retina. Knockdown of Arl6ip revealed the following phenotypic defects: microphthalmia, disorganized pigment pattern, flat head, defective tectum, deficient pectoral fins, abnormal pneumatic duct, pericardial edema, and deformed trunk. Particularly, histological dissection of the retinae of arl6ip -morphants revealed that neuronal differentiation is severely delayed, resulting in no formation of retinal layers. We further confirmed that opsins of arl6ip -morphants were not transcribed. Based on this evidence, Arl6ip may play important roles in zebrafish ocular, heart, and fin-bud development. Developmental Dynamics 238:232,240, 2009. © 2008 Wiley-Liss, Inc. [source]


    Patterning the embryonic kidney: BMP signaling mediates the differentiation of the pronephric tubules and duct in Xenopus laevis

    DEVELOPMENTAL DYNAMICS, Issue 1 2008
    Christina M. Bracken
    Abstract The Bone morphogenetic proteins (BMPs) mediate a wide range of diverse cellular behaviors throughout development. Previous studies implicated an important role for BMP signaling during the differentiation of the definitive mammalian kidney, the metanephros. In order to examine whether BMP signaling also plays an important role during the patterning of earlier renal systems, we examined the development of the earliest nephric system, the pronephros. Using the amphibian model system Xenopus laevis, in combination with reagents designed to inhibit BMP signaling during specific stages of nephric development, we revealed an evolutionarily conserved role for this signaling pathway during renal morphogenesis. Our results demonstrate that conditional BMP inhibition after specification of the pronephric anlagen is completed, but prior to the onset of morphogenesis and differentiation of renal tissues, results in the severe malformation of both the pronephric duct and tubules. Importantly, the effects of BMP signaling on the developing nephron during this developmental window are specific, only affecting the developing duct and tubules, but not the glomus. These data, combined with previous studies examining metanephric development in mice, provide further support that BMP functions to mediate morphogenesis of the specified renal field during vertebrate embryogenesis. Specifically, BMP signaling is required for the differentiation of two types of nephric structures, the pronephric tubules and duct. Developmental Dynamics 237:132,144, 2008. © 2007 Wiley-Liss, Inc. [source]


    Atlas of the developing inner ear in zebrafish

    DEVELOPMENTAL DYNAMICS, Issue 4 2002
    Michele Miller Bever
    Abstract This report provides a description of the normal developing inner ear of the zebrafish, Danio rerio, with special focus on the pars inferior. Zebrafish specimens, ranging in age from 3 to 30 days postfertilization (dpf), were processed for standard histologic sections or with a paint-fill method to show three-dimensional morphogenesis of the membranous labyrinth. Adult zebrafish (age 2 years) were also processed for inner ear paint-fills. Although development of the semicircular canals occurs rapidly (by 3 dpf), the pars inferior develops more gradually during days 5,20 postfertilization. A rudimentary endolymphatic duct emerges by 8 dpf. Differentiated hair cells of the lagenar macula are evident by 15 dpf, in a chamber located lateral and posterior to the saccule. By 20 dpf, the saccule itself is separated from the utricle, but remains connected by means of the utriculosaccular foramen. The maculae neglectae, each with differentiated hair cells, lie on the floor of the utricle near this foramen. A medial connection between the sacculi of right and left ears, the transverse canal, is also complete by 20 dpf. A ridge of mesenchyme, previously undescribed, bisects the saccule in zebrafish fry at 20,30 dpf. The images in the paint-fill atlas should provide a baseline for future studies of mutant zebrafish ears. © 2002 Wiley-Liss, Inc. [source]


    Enlarged vestibular aqueduct in two male siblings

    DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2002
    C M Varghese MSc MRCP FRCPCH
    This report describes the case history of two male siblings with sensorineural hearing loss and an enlarged vestibular aqueduct (EVA). Sibling 1 presented with a history of intermittent self-limiting ataxia and hearing loss at the age of 25 months and sibling 2 presented with a similar history at the age of 18 months. MRI showed an enlarged endolymphatic duct and sac bilaterally in both children. Perchlorate discharge tests were positive in both infants leading to a diagnosis of Pendred syndrome. A number of conditions associated with EVA are discussed with a view to devising management strategies. [source]


    Cytological features of cystadenocarcinoma in cyst fluid of the parotid gland: Diagnostic pitfalls and literature review

    DIAGNOSTIC CYTOPATHOLOGY, Issue 5 2010
    Akihiko Kawahara C.T., C.M.I.A.C., Ph.D.
    Abstract Cystadenocarcinoma is a rare malignant tumor, with an estimated incidence of 2% of malignant salivary gland tumors. Cytological diagnosis of cystadenocarcinoma is important for differential diagnosis between benign lesions and malignant tumors with cystic growth. We report a case of cystadenocarcinoma causing difficulty in cytological diagnosis. A 23-year-old man presented with an asymptomatic mass in the left parotid gland that had been present for 2 years. The mass was elastic hard, measuring 30 × 35 mm in diameter. Preoperative fine-needle aspiration cytology (FNAC) showed a small number of tumor cell clusters in the cystic fluid. The cluster was arranged in a ball-like structure and was cohesive with overlapping. Tumor cells had a small vacuolated, soap-bubble appearance in the cytoplasm. The papillary-cystic variant of acinic cell carcinoma (ACC-PCV) was suggested from these findings on FNAC. Histologically, the tumor was not encapsulated, but formed large cystic spaces against a background of fibrous connective tissue. The tumor cells in the cystic dilated duct showed papillary structures, which were continuous with the lining cuboidal cells. There was neither a definite double-layered arrangement in cystic ducts and solid islands nor histological findings characteristic of the papillary-cystic or follicular pattern of ACC-PCV. As tumor cells with a small vacuolated, soap-bubble appearance of the cytoplasm are common findings of both cystadenocarcinoma and ACC-PCV, they are of little use for differentiation; however, they are so characteristic that the majority of benign salivary gland lesions with cystic structures can be excluded, if enough attention is paid. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source]


    ENDOSCOPIC OCCLUSION OF CYSTIC DUCT USING N -BUTYL CYANOACRYLATE FOR POSTOPERATIVE BILE LEAKAGE

    DIGESTIVE ENDOSCOPY, Issue 4 2010
    Eric K. Ganguly
    Bile leak after cholecystectomy is well described, with the cystic duct remnant the site of the leak in the majority of cases. Endoscopic retrograde cholangiopancreatography (ERCP) with biliary stent placement has a high success rate in such cases. When ERCP fails, options include surgery, and percutaneous and endoscopic transcatheter occlusion of the site of bile leak. Here, we describe a case of endoscopic transcatheter occlusion of a persistent cystic duct bile leak after cholecystectomy using N -butyl cyanoacrylate glue. A 51-year-old man had persistent pain and bilious drainage following a laparoscopic cholecystectomy. The bile leak persisted after endoscopic placement of a biliary stent for a confirmed cystic duct leak. A repeat ERCP was carried out and the cystic duct was occluded with a combination of angiographic coils and N -butyl cyanoacrylate glue. The patient's pain and bilious drainage resolved. A follow-up cholangiogram confirmed complete resolution of the cystic duct leak and a patent common bile duct. [source]


    ALTERNATIVE METHODS IN THE ENDOSCOPIC MANAGEMENT OF DIFFICULT COMMON BILE DUCT STONES

    DIGESTIVE ENDOSCOPY, Issue 2010
    Dong Ki Lee
    The endoscopic method is accepted as a first treatment modality in the management of extrahepatic bile duct. Most large stones can be removed with basket and mechanical lithotripsy after endoscopic sphincterotomy. Currently, in treating large extrahepatic bile duct stones, endoscopic papillary large balloon dilation with mid-incision endoscopic sphincterotomy is actively performed instead of applying mechanical lithotripsy after full endoscopic sphincterotomy. Herein, we describe the conceptions, proper indications, methods and complications of endoscopic papillary large balloon dilation with regards to currently published reports. In addition, intracorporeal lithotripsy by peroral cholangioscopy with an ultra-slim upper endoscope is introduced, which is more convenient than previous conventional intracorporeal lithotripsy methods using mother,baby endoscopy or percutaneous transhepatic cholangioscopy. Lastly, biliary stenting with the choleretic agent administration method is briefly reviewed as an alternative treatment option for frail and elderly patients with large impacted common bile duct stones. [source]


    ROLE OF ENDOSCOPY IN SCREENING OF EARLY PANCREATIC CANCER AND BILE DUCT CANCER

    DIGESTIVE ENDOSCOPY, Issue 2009
    Kiyohito Tanaka
    In the screening of early pancreatic cancer and bile duct cancer, the first issue was ,what are the types of abnormality in laboratory data and symptoms in case of early pancreatic cancer and bile duct cancer?' Early cancer in the pancreaticobiliary region has almost no symptoms, however epigastralgia without abnormality in the gastrointestinal (GI) tract is a sign of early stage pancreaticobiliary cancer. Sudden onset and aggravation of diabetes mellitus is an important change in the case of pancreatic cancer. Extracorporeal ultrasonography is a very useful procedure of checking up changes of pancreatic and biliary lesions. As the role of endoscopy in screening, endoscopic ultrasonography (EUS) is the most effective means of cancer detection of the pancreas, and endoscopic retrograde cholangiopancreatography (ERCP) is most useful of diagnosis tool for abnormalities of the common bile duct. Endoscopic retrograde cholangiopancreatography is an important modality as the procedure of sampling of diagnostic materials. Endoscopic ultrasonography-fine needle aspiration (EUS-FNA) has the role of histological diagnosis of pancreatic mass lesion also. Especially, in the case of pancreas cancer without evidence of cancer by pancreatic juice cytology and brushing cytology, EUS-FNA is essential. Intra ductal ultrasonography (IUDS) and perotral cholangioscopy (POCS) are useful for determination of mucosal extent in extrahepatic bile duct cancer. Further improvements of endoscopical technology, endoscopic procedures are expected to be more useful modalities in detection and diagnosis of early pancreatic and bile duct cancers. [source]


    RISK FACTORS FOR RECURRENT BILE DUCT STONES AFTER ENDOSCOPIC PAPILLARY BALLOON DILATION: LONG-TERM FOLLOW-UP STUDY

    DIGESTIVE ENDOSCOPY, Issue 2 2009
    Akira Ohashi
    Background:, Little is known about the long-term results of endoscopic papillary balloon dilation (EPBD) for bile duct stones. Methods:, Between 1995 and 2000, 204 patients with bile duct stones successfully underwent EPBD and stone removal. Complete stone clearance was confirmed using balloon cholangiography and intraductal ultrasonography (IDUS). Long-term outcomes of EPBD were investigated retrospectively in the year 2007, and risk factors for stone recurrence were multivariately analyzed. Results:, Long-term information was available in 182 cases (89.2%), with a mean overall follow-up duration of 9.3 years. Late biliary complications occurred in 22 patients (12.1%), stone recurrence in 13 (7.1%), cholangitis in 10 (5.5%), cholecystitis in four, and gallstone pancreatitis in one. In 11 of 13 patients (84.6%), stone recurrence developed within 3 years after EPBD. All recurrent stones were bilirubinate. Multivariate analysis identified three risk factors for stone recurrence: dilated bile duct (>15 mm), previous cholecystectomy, and no confirmation of clean duct using IDUS. Conclusion:, Approximately 7% of patients develop stone recurrence after EPBD; however, retreatment with endoscopic retrograde cholangiopancreatography is effective. Careful follow up is necessary in patients with dilated bile duct or previous cholecystectomy. IDUS is useful for reducing stone recurrence after EPBD. [source]


    CHARACTERISTIC INTRADUCTAL ULTRASONOGRAPHIC FEATURES OF PORTAL BILIOPATHY

    DIGESTIVE ENDOSCOPY, Issue 4 2008
    Tsukasa Ikeura
    The term ,portal biliopathy' is used to describe cholangiographic abnormalities seen in patients with extrahepatic portal vein obstruction. Portal biliopathy is mainly composed of extrinsic compression of the bile duct caused by enlarged venous collaterals. Herein we report a case of asymptomatic portal biliopathy caused by idiopathic extrahepatic portal vein obstruction. In the present case, intraductal ultrasonography showed normal anatomic layers of the distal common bile duct wall, surrounded by numerous tubular structures which were suspected to be collateral vessels. We suggest that intraductal ultrasonography may be a helpful imaging procedure for detection of this pathological condition. [source]


    TEACHING DEEP CANNULATION OF THE BILE DUCT DURING ENDOSCOPIC RETROGRADE CHOLANGIOGRAPHY

    DIGESTIVE ENDOSCOPY, Issue 4 2007
    Kiichi Tamada
    When performing endoscopic retrograde cholangiopancreatography (ERCP), the smooth introduction of the duodenoscope into the papilla of Vater, an appropriate view of the papilla of Vater, and deep cannulation of the bile duct are essential. The operator must know the difference between the side-viewing endoscope and the forward-viewing endoscope. The rotation of the body and the left arm of the operator, switching with the left wrist, and dialing of the endoscope are essential for appropriately viewing the papilla of Vater. When training operators to do ERCP, a model is useful for helping them understand basic handling. The approach to deep cannulation of the bile duct should be selected based on the type of papilla (slit type, onion type, tongue protrusion type, flat type, and tumor type). Cannulation is more difficult in patients with the tongue protrusion-type of papilla than with a slit type, onion type, or tumor type. According to previous reports, therapeutic ERCP requires the ability to cannulate the common bile duct deeply 80% of the time; 180 to 200 supervised ERCP are necessary to achieve this success rate. [source]