Orifice

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Orifice

  • duct orifice
  • natural orifice

  • Terms modified by Orifice

  • orifice area
  • orifice transluminal endoscopic surgery

  • Selected Abstracts


    Efficient Synthesis of Open-Cage Fullerene Derivatives Having 16-Membered-Ring Orifices.

    CHEMINFORM, Issue 49 2007
    Manolis M. Roubelakis
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]


    In vivo confocal microscopy of the bulbar conjunctiva

    CLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 4 2009
    Nathan Efron PhD DSc
    Abstract Background:, The aim of this work is to develop a more complete qualitative and quantitative understanding of the in vivo histology of the human bulbar conjunctiva. Methods:, Laser scanning confocal microscopy (LSCM) was used to observe and measure morphological characteristics of the bulbar conjunctiva of 11 healthy human volunteer subjects. Results:, The superficial epithelial layer of the bulbar conjunctiva is seen as a mass of small cell nuclei. Cell borders are sometimes visible. The light grey borders of basal epithelial cells are clearly visible, but nuclei can not be seen. The conjunctival stroma is comprised of a dense meshwork of white fibres, through which traverse blood vessels containing cellular elements. Orifices at the epithelial surface may represent goblet cells that have opened and expelled their contents. Goblet cells are also observed in the deeper epithelial layers, as well as conjunctival microcysts and mature forms of Langerhans cells. The bulbar conjunctiva has a mean thickness of 32.9 ± 1.1 µm, and a superficial and basal epithelial cell density of 2212 ± 782 and 2368 ± 741 cells/mm2, respectively. Overall goblet and mature Langerhans cell densities are 111 ± 58 and 23 ± 25 cells/mm2, respectively. Conclusions:, LSCM is a powerful technique for studying the human bulbar conjunctiva in vivo and quantifying key aspects of cell morphology. The observations presented here may serve as a useful marker against which changes in conjunctival morphology due to disease, surgery, drug therapy or contact lens wear can be assessed. [source]


    Histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusa (Mecoptera: Panorpidae)

    ACTA ZOOLOGICA, Issue 4 2010
    Shuyu Liu
    Abstract Liu, S. and Hua, B. 2009. Histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusa (Mecoptera: Panorpidae). ,Acta Zoologica (Stockholm) 91: 457,465. The morphology, histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusaCheng 1949 were investigated using light microscopy and scanning and transmission electron microscopy. The salivary glands display a distinct sexual dimorphism. The female has only two small sac-like glands located in the prothorax, while the male possesses six long tubular glands extending into the sixth abdominal segment. The male salivary glands can be divided into five distinct regions. The apical long, thin secretory region possesses numerous secretory cells containing large secretory vesicles; the salivary reservoir expands in diameter, accumulating and temporarily storing the saliva in addition to secreting saliva; the constricted region contains prismatic cells with complex infolded plasma membrane; the sac has an internal brush border to absorb water and ions; the common salivary duct contains longitudinal muscles in the male, but not in the female. The salivary pump possesses independent strong dorsal muscles and abundant internal palm spines near its orifice. The anatomy and ultrastructure of the salivary glands and the salivary pump of scorpionflies as well as their possible functions are briefly discussed. [source]


    Assessment of the Tilting Properties of the Human Mitral Valve during Three Main Phases of the Heart Cycle: An Echocardiographic Study

    ECHOCARDIOGRAPHY, Issue 4 2006
    Daniel Vanhercke B.N., N.F.E.S.C., R.D.C.S.
    Rationale and Objectives: In experimental models of the left heart, the mitral valve (MV) is commonly implanted perpendicular to a central axis of the apex/MV. To adapt this to a more correct anatomical model, as well as for further studies of the left ventricle, we created a database of implantation angles of the MV and annulus during three main phases of the heart cycle, based on standard cardiac ultrasound measurements. Materials and Methods: Twenty-eight patients were studied with the standard cardiac ultrasound equipment. From the apical echo window, an anteroposterior (AP) plane and a perpendicular commisure-commisure (CC) plane were generated during three critical moments in the heart cycle: systole (S); diastole early filling (E); and diastole late filling (A). In both planes, the angles between the annular plane and each mitral leaflet, as well as the angle between a theoretical longitudinal axis through the apex and center of the MV orifice and the mitral annulus plane, were measured with a custom-made application of Matlab R14. Results: We observed an inclination of the angle mitral annulus/central left ventricle axis, with its lowest point in the direction of the aortic valve (AP plane) of 85°± 7° in systole (S), 88°± 8° in early diastole (E), and 88°± 7° in late diastole (A). In the CC plane, we observed an almost horizontal implantation of 91°± 5° in systole (S), 91°± 8° in early diastole (E), and 91°± 7° in late diastole (A). [source]


    Comparison of Proximal Isovelocity Surface Area Method and Pressure Half Time Method for Evaluation of Mitral Valve Area in Patients Undergoing Balloon Mitral Valvotomy

    ECHOCARDIOGRAPHY, Issue 9 2005
    Thottuvelil Narayanan Sunil Roy M.D.
    Background: The pressure half time (PHT) method is unreliable for measurement of mitral valve area (MVA) immediately after valvotomy. The proximal isovelocity surface area (PISA) method has been used to derive mitral valve area in patients with mitral stenosis. The aim of our study was to compare PISA method and PHT method in patients undergoing percutaneous balloon mitral valvotomy (BMV). Methods: The PISA was recorded from the apex and MVA was calculated using continuity equation by the formula 2,r2 Vr/Vm, where 2,r2 is the hemispheric isovelocity area, Vr is the velocity at the radial distance "r" from the orifice, and Vm is the peak velocity. A plain angle correction factor (,)/180 was used to correct the inlet angle subtended by leaflet tunnel as a result of leaflet doming. Results: MVA calculated using PISA method (r = 0.5217, P < 0.0001, SE = 0.016) and PHT (r = 0.6652, P < 0.0001, SE = 0.017) correlated well with 2D method in patients with mitral stenosis before BMV. After BMV, MVA by PISA method correlated well with 2D planimetry (r = 0.5803, P < 0.0001, SE = 0.053) but PHT showed poor correlation (r = 0.1334, P = 0.199, SE = 0.036). The variability of measurement of MVA was most marked with PHT method in the post-BMV period. Conclusion: The PISA method correlates well with 2D planimetry in patients with mitral stenosis before and after BMV and is superior to the PHT method in the post-BMV period where the latter may be unreliable. [source]


    The Use of Anatomic M-Mode Echocardiography to Determine the Left Atrial Appendage Functions in Patients with Sinus Rhythm

    ECHOCARDIOGRAPHY, Issue 2 2005
    Yekta Gurlertop M.D.
    Left atrial appendage (LAA) contractile dysfunction is associated with thrombus formation and systemic embolism. LAA function is determined by its flow velocities and fractional area change. This study was performed in order to determine the LAA functions with the anatomic M-mode echocardiography (AMME). Our study comprised 74 patients who had sinus rhythm and underwent transesophageal echocardiography (TEE) for various reasons. LAA fractional change (LAAFAC) was measured by manual planimetry in a transverse basal short-axis approach and LAA emptying and filling velocities also were measured. The AMME values were determined by an M-mode cross section from a cursor placed beneath the orifice of the LAA in transverse basal short-axis imaging. From these values LAA fractional shortening (LAAFS) and ejection fraction (LAAEF) were calculated. LAAEF was calculated by the Teicholz method. The comparisons were conducted, and no correlations between the LAA late filling and the anatomic M-mode values were found (for LAAFS r = 0.18; P > 0.05 and for LAAEF r = 0.19; P > 0.05). There were significant but poor correlations among the LAA late emptying with the anatomic M-mode measurements (for LAAFS r = 0.26; P < 0.05 and for LAAEF r = 0.30; P < 0.01), whereas, there were significant and good correlations between the LAAFAC and the anatomic M-mode values (for LAAFS r = 0.75; P < 0.01 and for LAAEF r = 0.78; P < 0.01). There were significant differences between the valvular heart disease group and the normal group, and between the valvular heart disease group and the ASD group (for LAAFAC P < 0.01, for LAAEF P < 0.01, for LAAFS P < 0.01). There was no difference between the normal group and the ASD group. Our study showed that the LAAEF and LAAFS in patients with sinus rhythm obtained via anatomical M-mode echocardiography is a new method, which can be used instead of left atrial appendage area change. [source]


    In Vitro Validation of a New Approach for Quantitating Regurgitations Using Proximal Isovelocity Surface Area

    ECHOCARDIOGRAPHY, Issue 7 2000
    A. Delouche
    The present work has been designed to validate the calculation of the effective regurgitant orifice (ERO) area with the use of a new formula that takes into account the velocity profile (Vr vs r) and that is insensitive to errors in the determination of the position of the orifice. Assuming a hemispheric model, ERO = 2,r2· Vr/Vo (with Vo= velocity at the orifice) and (Vo/Vr)0.5= (2,/ERO)0.5r. Thus, the slope of the corresponding linear regression allows ERO to be calculated as: ERO = 2,/slope2. This approach was tested in vitro in pulsatile conditions on circular, conical, and slit-like orifices. The calculated ERO was compared with the actual jet cross sectional area derived from the transverse velocity profile at the jet origin. For the purpose of comparison, the "classical" ERO was calculated for all the configurations, angulations, and threshold velocities. The relationship between (Vo/Vr)0.5 was linear (r > 0.98) over a wide range of velocities. The nonhemispheric components were found to modify the constant and not the slope. The mean variation of the calculated ERO was 6.5%. The correlation between the calculated and the actual ERO was very close (>0.97) with slope equal to 0.96. By comparison with the new method, the classical formula gave an underestimation of the ERO that dramatically increased when studying the flow closer to the orifice or in the case of error on the measurement of r. In conclusion, a method using velocity profiles instead of isolated values improves the accuracy of the proximal isovelocity surface area (PISA) method for measuring the ERO. [source]


    Influence of the Orifice Inlet Angle on the Velocity Profile Across a Flow Convergence Region by Color Doppler In Vitro

    ECHOCARDIOGRAPHY, Issue 5 2000
    Martin Giesler M.D.
    The converging flow field proximal to a leaking valve is determined among other things by the orifice inlet angle formed by the leaflets. Thus, the inlet angle affects the determination of regurgitant flow rate by the flow convergence method. Based on the hypothesis of spheric isovelocity surfaces, others had postulated that a local velocity within the flow convergence should change inversely proportional to changes in the three-dimensional inlet angle. This concept would allow correction of the determination of regurgitant flow for nonplanar orifice inlet angles. We tested this concept in vitro. In a flow model, the flow convergence region proximal to different orifice plates was imaged by color Doppler: funnel-shaped, planar and tip-shaped (inverted funnels) orifice plates, with circular orifices of 2- and 7-mm diameter. Velocity profiles across the flow convergence along the flow centerline were read from the color maps. As predicted, the local velocities were inversely related to the inlet angle, but only at the 2-mm funnel orifices, this effect was inversely proportional to the three-dimensional inlet angle (i.e., in agreement with the mentioned concept). However, for any 7-mm orifice and/or inlet angle of > 180°, the effect of the inlet angle was considerably less than predicted by the aforementioned concept. With increasing orifice diameter and with decreasing distance to the orifice, the effect of the orifice inlet angle was reduced. The effect of the orifice inlet angle on the flow convergence region is modulated by orifice size and the distance to the orifice. Therefore, correction of flow estimates in proportion to the three-dimensional inlet angle will lead to considerable errors in most situations of clinical relevance, namely to massive overcorrection when analyzing velocities located close to wide orifices. [source]


    Solid Contact Micropipette Ion Selective Electrode II: Potassium Electrode for SECM and In Vivo Applications

    ELECTROANALYSIS, Issue 17-18 2009
    Gergely Gyetvai
    Abstract Micropipette ion selective electrodes are very small, but fragile, short-life time sensors with very high resistance. Their high resistance is a draw back considering application in scanning electrochemical microscopy (SECM) and in life sciences. New, low resistance potassium micropipette electrodes were prepared, and applied. The electrode contains solid internal contact made of a carbon fiber lowered down all the way close to the orifice of the micropipette. The internal contact potential was kept constant by applying a doped, electrochemically prepared PEDOT coating on the fiber surface. The electrode performed well in in vivo experiments both in plant and animal tissue without capacitance neutralization and in SECM. [source]


    Solid Contact Micropipette Ion Selective Electrode for Potentiometric SECM

    ELECTROANALYSIS, Issue 10 2007
    Gergely Gyetvai
    Abstract New solid contact ammonium micropipette electrodes (ISE), well applicable in scanning electrochemical microscopy are reported. The solid contact was made of a PEDOT nanowire coated carbon fiber, lowered down close to the orifice, and dipped inside the cocktail being in the pipette tip. This configuration provided low electrical resistance and good potential stability. Submicron tip size, usual in case of micropipette ISE-s easily can be fabricated in this way. The applicability of the electrode in SECM has been proved in SG/TC mode imaging urease enzyme active spots in urea solutions. [source]


    Chip-CE/MS using a flat low-sheath-flow interface

    ELECTROPHORESIS, Issue 24 2008
    Fu-An Li
    Abstract A chip-CE/ESI/MS interface based on a low-sheath-flow design has been developed. A flat low-sheath-flow interface was fabricated to facilitate the coupling with a CE microchip. The interface consists of a PMMA reservoir block, a PMMA platform and a replaceable ESI sprayer. A CE interface was constructed by using a wire-assisted epoxy-fixing method to connect a 1.5,cm connecting capillary to the end of chip-CE channel. The opposite end of the connecting capillary was tapered to approximately 40,,m od to fit tightly inside the back end of a removable fused-silica capillary ESI sprayer, which was also tapered to give a 10,,m orifice. With this 1.5,cm connecting capillary, the sheath liquid flowed coaxially around the connecting capillary to create a low dead volume liquid junction at the interface between the connecting capillary and the ESI emitter. An advantage of the current design over existing chip-based CE/MS interfaces is that ESI emitter can easily be replaced. The analytical utility of this microdevice was demonstrated by the analysis of two synthetic mixtures: a series histamine antagonists and a mixture of synthetic peptides. [source]


    Diagnosis and treatment of chronic recurrent caecal impaction

    EQUINE VETERINARY JOURNAL, Issue S32 2000
    B. HUSKAMP
    Summary Ninety-six horses with chronic recurrent caecal impaction associated with hypertrophy of muscle layers in the caecal base or in the whole caecum were examined from 1990 to 1996. Enlargement of the caecocolic orifice was completed surgically in 58 horses. Of those horses having surgery, 50 were discharged from the hospital while 8 were subjected to euthanasia at the hospital due to complications. Twenty-seven of the 50 horses discharged were normal at follow-up while 23 died or were subjected to euthanasia due to acute or recurrent colic, recurrent impaction in the ascending or descending colon, complete caecal muscle layer hypertrophy, stomach rupture or lymphosarcoma. Approximately 50% of the cases were successfully treated by surgical enlargement of the caecocolic orifice. The results suggest, on the other hand, that enlargement of the caecocolic orifice was not successful in treating horses with hypertrophy of the caecal muscle layer in the whole caecum. [source]


    Muscle thickness and neuron density in the caecum of horses with chronic recurrent caecal impaction

    EQUINE VETERINARY JOURNAL, Issue S32 2000
    G. F. SCHUSSER
    Summary In this study, the hypothesis that caecal smooth muscle layers would be thinner and the linear neuron density of myenteric plexus greater was tested in normal horses compared to those with chronic recurrent caecal impaction. Four normal horses and 18 horses with chronic recurrent caecal impaction were subjected to euthanasia and 7 tissue samples were collected from each horse at different regions of the caecum (apex, dorsal body, cranial base, dorsal base, caudal base, caudal body, ventral body). Twelve horses with chronic recurrent caecal impaction were treated surgically. Only one tissue sample of the cranial part of the caecal base close to the caecocolic orifice was taken during surgery. The thickness of the circular muscle layer of all caecal regions measured in killed horses with chronic recurrent caecal impaction was significantly increased compared to the equivalent caecal region of normal horses. On the other hand, the longitudinal muscle layer was significantly thicker only in the cranial and caudal caecal base and in the dorsal region of the caecal body. The linear neuron densities of all caecal base areas and 2 caecal body regions, the caudal body region and of the apex, of killed horses with chronic recurrent caecal impaction were significantly lower compared with those in clinically normal horses. The circular muscle layer of all caecal regions was thickened (hypertrophied) probably as a consequence of chronic uncoordinated hypercontractility due to neuron deficit in the myenteric plexus of the caecal base. [source]


    Transfer of hydrocarbons from natural seeps to the water column and atmosphere

    GEOFLUIDS (ELECTRONIC), Issue 2 2002
    I. R. MacDonald
    Abstract Results from surface geochemical prospecting, seismic exploration and satellite remote sensing have documented oil and gas seeps in marine basins around the world. Seeps are a dynamic component of the carbon cycle and can be important indicators for economically significant hydrocarbon deposits. The northern Gulf of Mexico contains hundreds of active seeps that can be studied experimentally with the use of submarines and Remotely Operated Vehicles (ROV). Hydrocarbon flux through surface sediments profoundly alters benthic ecology and seafloor geology at seeps. In water depths of 500,2000 m, rapid gas flux results in shallow, metastable deposits of gas hydrate, which reduce sediment porosity and affect seepage rates. This paper details the processes that occur during the final, brief transition , as oil and gas escape from the seafloor, rise through the water and dissolve, are consumed by microbial processes, or disperse into the atmosphere. The geology of the upper sediment column determines whether discharge is rapid and episodic, as occurs in mud volcanoes, or more gradual and steady, as occurs where the seep orifice is plugged with gas hydrate. In both cases, seep oil and gas appear to rise through the water in close proximity instead of separating. Chemical alteration of the oil is relatively minor during transit through the water column, but once at the sea surface its more volatile components rapidly evaporate. Gas bubbles rapidly dissolve as they rise, although observations suggest that oil coatings on the bubbles inhibit dissolution. At the sea surface, the floating oil forms slicks, detectable by remote sensing, whose origins are laterally within ,1000 m of the seafloor vent. This contradicts the much larger distance predicted if oil drops rise through a 500 m water column at an expected rate of ,0.01 m s,1 while subjected to lateral currents of ,0.2 m s,1 or greater. It indicates that oil rises with the gas bubbles at speeds of ,0.15 m s,1 all the way to the surface. [source]


    Localization of root canal orifices in mandibular second molars in relation to occlusal dimension

    INTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2009
    O. Gorduysus
    Abstract Aim, To evaluate the localization and distribution of canal orifices of mandibular second molar teeth in relation to the mesio-distal and bucco-lingual dimensions of coronal tissue. Methodology, Fifty extracted mandibular second molar teeth were embedded into plaster blocks with their vertical axes aligned perpendicular to the horizontal plane. The teeth were photographed digitally from the occlusal aspect under 12 × magnification. Thereafter, the occlusal halves of crowns were sectioned off to expose the root canal orifices. The teeth were than photographed under the same magnification, after which the pre- and post-sectioning images of each specimen were stacked into a single file. To plot the coordinate of each canal orifice, a 0.5-mm grid analytical plane was mounted digitally on the stack so that the x - and y -axes of the plane were superimposed on the mesiodistal and buccolingual axes (bisectors) of the tooth crowns. Localization and distribution of the coordinates of the canal orifices were evaluated using the chi-square test (P = 0.05). Results, Only one tooth displayed a single root canal orifice, located in the mesiobuccal-distolingual ,centre' of the occlusal surface. The majority of mandibular second molars had three orifices (72%), followed by those with two (16%) and four (10%). The distal canal was located lingual to the centre of the occlusal plane. Conclusion, The distal canal was located lingual to the centre of the occlusal plane of mandibular second molars. The possibility of observing more divergent localizations and orifice numbers should not be overlooked in clinical practice. [source]


    Shaping ability of Hero 642 rotary nickel,titanium instruments in simulated root canals: Part 2

    INTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2000
    S. A. Thompson
    Abstract Aim To determine the shaping ability of Hero 642 nickel,titanium rotary instruments during the preparation of simulated canals. Methodology A total of 40 simulated root canals made up of four different shapes, in terms of angle and position of curvature, were prepared by Hero 642 instruments using a crown-down preparation sequence. Pre- and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and postoperative views were superimposed to highlight the amount and position of material removed during preparation. This report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape. Results Four zips and four elbows were created during preparation, all in canals with 40°, 12 mm curves. No perforations or danger zones were created. Highly significant differences (P < 0.001) were apparent between the canal shapes in total canal width at the apex and beginning of the curve, and in the amount of resin removed from the inner and outer aspects of the curve at the orifice. Canal transportation was most frequently directed toward the outer aspect of the curve at specific points along the canal, except at the orifice, where it was apparent that canals with 20° curves transported toward the inner. Overall, mean absolute transportation was always less than 0.15 mm; however, significant differences occurred between canal shapes at the end-point (P < 0.01), apex of the curve (P < 0.01) and at the orifice (P < 0.01). Conclusions Under the conditions of this study, Hero 642 rotary nickel,titanium instruments created canals with few aberrations and no perforations. The relatively high proportion of aberrations in canals with short, acute curves may indicate that instruments with increased taper should be used with caution at or near the full working distance. Further research in real teeth is necessary to elucidate the full potential of these new rotary instruments for use in root canal preparation. [source]


    Sporadic dystrophic epidermolysis bullosa with albopapuloid and prurigo- and folliculitis-like lesions

    INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 8 2009
    Yi-Ming Fan MD
    A case of sporadic dystrophic epidermolysis bullosa (DEB) with albopapuloid and prurigo- and folliculitis-like lesions is reported. Histopathology of the scalp biopsy showed hyperkeratosis, a subepidermal cleft near the orifice of a hair follicle, dermal fibrosis, and a moderate perivascular and perifollicular lymphohistiocytic inflammatory cell infiltrate in the papillary dermis, without neutrophilic infiltrate in the orifice of the hair follicle. It is uncertain whether the present case should be classified as DEB pruriginosa or represents a new subtype of DEB. [source]


    Stop female genital mutilation: appeal to the international dermatologic community

    INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 5 2002
    Aldo Morrone MD
    Female genital mutilation (FGM) is a traditional cultural practice, but also a form of violence against girls, which affects their lives as adult women. FGM comprises a wide range of procedures: the excision of the prepuce; the partial or total excision of the clitoris (clitoridectomy) and labia; or the stitching and narrowing of the vaginal orifice (infibulation). The number of girls and women who have been subjected to FGM is estimated at around 137 million worldwide and 2 million girls per year are considered at risk. Most females who have undergone mutilation live in 28 African countries. Globalization and international migration have brought an increased presence of circumcised women in Europe and developed countries. Healthcare specialists need to be made aware and trained in the physical, psychosexual, and cultural aspects and effects of FGM and in the response to the needs of genitally mutilated women. Health education programs targeted at immigrant communities should include information on sexuality, FGM, and reproduction. Moreover, healthcare workers should both discourage women from performing FGM on their daughters and receive information on codes of conduct and existing laws. The aim is the total eradication of all forms of FGM. [source]


    Thermal-fluid transport phenomena in an axially rotating flow passage with twin concentric orifices of different radii

    INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2006
    Shuichi Torii
    Abstract This paper investigates the thermal fluid-flow transport phenomena in an axially rotating passage in which twin concentric orifices of different radii are installed. Emphasis is placed on the effects of pipe rotation and orifice configuration on the flow and thermal fields, i.e. both the formation of vena contracta and the heat-transfer performance behind each orifice. The governing equations are discretized by means of a finite-difference technique and numerically solved for the distributions of velocity vector and fluid temperature subject to constant wall temperature and uniform inlet velocity and fluid temperature. It is found that: (i) for a laminar flow through twin concentric orifices in a pipe, axial pipe rotation causes the vena contracta in the orifice to stretch, resulting in an amplification of heat-transfer performance in the downstream region behind the rear orifice, (ii) simultaneously the heat transfer rate in the area between twin orifice is intensified by pipe rotation, (iii) the amplification of heat transfer performance is affected by the front and rear orifice heights. Results may find applications in automotive and rotating hydraulic transmission lines and in aircraft gas turbine engines. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    Idiopathic myelofibrosis with extramedullary haemopoiesis involving the urinary bladder in a Chinese lady

    INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2002
    Y. K. MAK
    Extramedullary haemopoiesis (EMH) associated with idiopathic myelofibrosis most commonly involves the reticuloendothelial organs, such as the spleen and liver, although ectopic haemopoietic tissue has also been described rarely in the lymph nodes, skin, gastrointestinal tract, pleura, peritoneum, central nervous system, and genital and urinary tracts. We report on a 54-year-old Chinese lady with a long history of idiopathic myelofibrosis who presented with gross haematuria and left hydronephrosis due to EMH in the bladder trigone. Cystoscopic examination revealed a sessile necrotic papillary growth at the trigone, obstructing the left ureteric orifice. Transurethral resection of the bladder tumour was performed, and microscopic examination of the tumour chips demonstrated atypical megakaryocytes, immature granulocytes and normoblasts, confirming the presence of EMH. The residual bladder tumour responded well to low dose radiotherapy, with subsequent disappearance of haematuria and normalization of ultrasonogram findings. [source]


    Ejaculatory dysfunction caused by the new ,1 -blocker silodosin: A preliminary study to analyze human ejaculation using color Doppler ultrasonography

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 10 2008
    Atsushi Nagai
    Objectives: In order to clinically investigate the mechanism of ejaculatory dysfunction attributable to the ,1 -blocker silodosin, a real-time observation of ejaculation by healthy males was performed. Methods: Following intake of silodosin, a newly developed selective ,1 -blocker for benign prostatic hypertrophy, ejaculation was dynamically observed using color Doppler ultrasound in three healthy males. Normal ejaculation was also investigated in the same manner. Results: With silodosin intake, no antegrade ejaculation was observed in cases 1 or 2. In case 1, seminal fluid slowly but continuously flowed out from the seminal vesicles into the bladder. In case 2, only a small amount of seminal fluid flowed into the bladder during the ejaculatory sensation. In case 3, ejection of a small amount of semen from the external urethral orifice was observed and inflow of a small amount of seminal fluid into the bladder was also captured. Without silodosin intake, all three subjects exhibited antegrade ejaculation. Conclusions: The mechanism of ejaculatory dysfunction is intricately related to retrograde ejaculation (retrograde inflow of seminal fluid), insufficient contraction of the seminal vesicles, and insufficient rhythmic contraction of the muscles of the pelvic floor. [source]


    Filarial chyluria: Long-term experience of a university hospital in India

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 4 2004
    VIPUL TANDON
    Abstract Background: Filariasis is an endemic problem in various Indian states. We evaluated the results of long-term follow up (10,20 years) of patients with filarial chyluria. Methods: We conducted a retrospective analysis of 160 patients treated for filarial chyluria who presented to the Banaras Hindu University Hospital from 1982 to 1992. Eighty-four patients (52.5%) were treated using diethylcarbamazine (DEC) and a fat restricted diet and 76 patients (47.5%) underwent surgery. To examine the long-term effects of filarial chyluria we analysed data on post-treatment recurrence, weight gain, dietary freedom, chyluria free period and a number of other associated factors. Results: Previous history of filariasis or its complication was documented in 19% of patients. In 71% of cases, cystoscopy showed that chylous efflux was predominant in the left ureteric orifice. The long-term remission rate was 62% in the conservatively managed group (DEC + fat restricted diet), whereas 90% of patients in the operated group were cured. Postoperative recurrence rate was 10%. There was more weight gain and dietary freedom along with a longer chyluria free period in the operated group relative to the conservatively managed group. Conclusions: Definitive surgical ablation of lymphatic urinary fistula is better than conservative medical management because it has a higher success rate, more dietary freedom and, therefore, better patient acceptability. [source]


    Evaluation of cases where the right kidney is higher than the left kidney

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 7 2003
    SEIICHI SAITO
    Abstract Background: Finding the right kidney higher than the left kidney on excretory urography (EXU) is unusual. In the present study, the position of the kidneys was evaluated in patients, and the frequency, causes or attribution were investigated. Methods: Kidney positions were evaluated in 1625 patients. Subsequent evaluations by computed tomography scan were performed for each case where the right kidney was higher than the left. If a patient had right hydronephrosis, bladder evaluations such as ultrasonography and/or cystoscopy were also conducted. Patients with a left contracted kidney were excluded. Results: The right kidney was higher than the left in 81 (5%) of 1625 cases. In 30 cases (37%), the cause or attribution existed in the right urinary tract. Eleven of these cases were due to tumors or cysts in the right kidney, four were due to congenital anomalies, and 15 were due to hydronephrosis. In 10 (12.3%) of the cases, the cause or attribution existed in the left urinary tract. All of them were cysts or tumors of the left kidney. Of the other 13 (16.0%) cases, eight were caused by hepatatrophy and splenomegaly as a result of liver cirrhosis, two were caused by aortic aneurysm, one was caused by visceral inversion, one was caused by a right ovarian tumor, and one was caused by pneumonectomy. Malignancies, including two renal cell carcinomas and three bladder cancers at the right ureteral orifice, were found in five cases (6%). Conclusion: The above results suggest that the right kidney is higher than the left in five percent of all cases undergoing EXU. In cases where the right kidney is higher than the left, and a left contracted kidney cannot be found, further evaluation is recommend. [source]


    Acute urethritis caused by Neisseria meningitidis

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2003
    NORIYUKI KANEMITSU
    Abstract A 48-year-old heterosexual Japanese man visited the outpatient clinic of Nagoya Urology Hospital, complaining of burning pain at voiding and pus discharge from the urethral orifice. These symptoms appeared the day following oral-genital contact (fellatio) with a commercial sex worker. On the basis of the presumptive clinical diagnosis of gonorrhea because of the microscopic detection of diplococci in the urethral discharge, he was treated with levofloxacin (300 mg per day) for 7 days. His symptoms responded quickly and urinalysis taken 7 days later was normal. Microbiological examinations isolated Neisseria meningitidis in the urethral discharge by culture with the use of enzymatic profiles. Further prevalence of sexually transmitted diseases (STD) through oral-genital contact would lead to an increase in meningococcal urethritis. [source]


    Correlation between gross anatomical topography, sectional sheet plastination, microscopic anatomy and endoanal sonography of the anal sphincter complex in human males

    JOURNAL OF ANATOMY, Issue 2 2009
    S. Al-Ali
    Abstract This study elucidates the structure of the anal sphincter complex (ASC) and correlates the individual layers, namely the external anal sphincter (EAS), conjoint longitudinal muscle (CLM) and internal anal sphincter (IAS), with their ultrasonographic images. Eighteen male cadavers, with an average age of 72 years (range 62,82 years), were used in this study. Multiple methods were used including gross dissection, coronal and axial sheet plastination, different histological staining techniques and endoanal sonography. The EAS was a continuous layer but with different relations, an upper part (corresponding to the deep and superficial parts in the traditional description) and a lower (subcutaneous) part that was located distal to the IAS, and was the only muscle encircling the anal orifice below the IAS. The CLM was a fibro-fatty-muscular layer occupying the intersphincteric space and was continuous superiorly with the longitudinal muscle layer of the rectum. In its middle and lower parts it consisted of collagen and elastic fibres with fatty tissue filling the spaces between the fibrous septa. The IAS was a markedly thickened extension of the terminal circular smooth muscle layer of the rectum and it terminated proximal to the lower part of the EAS. On endoanal sonography, the EAS appeared as an irregular hyperechoic band; CLM was poorly represented by a thin irregular hyperechoic line and IAS was represented by a hypoechoic band. Data on the measurements of the thickness of the ASC layers are presented and vary between dissection and sonographic imaging. The layers of the ASC were precisely identified in situ, in sections, in isolated dissected specimens and the same structures were correlated with their sonographic appearance. The results of the measurements of ASC components in this study on male cadavers were variable, suggesting that these should be used with caution in diagnostic and management settings. [source]


    Chordal Cutting VIA Aortotomy in Ischemic Mitral Regurgitation: Surgical and Echocardiographic Study

    JOURNAL OF CARDIAC SURGERY, Issue 1 2008
    Georges Fayad M.D.
    In addition, MR may exacerbate during exercise not only trough exercise-induced ischemia but also through an increase in tenting area. Accordingly, we aimed to perform chordal cutting through aortotomy in patients with exercise-induced ischemic worsening of MR. Methods: Five patients with ischemic MR, due to anterior leaflet tenting, whichworsened during exercise echocardiography were enrolled. All patients underwent cutting of the 2 basal chordae attached to the anterior mitral leaflet associated with myocardial revascularization. Three patients had additional mitral valve annuloplasty. Postoperative MR was evaluated using exercise echocardiography. Results: Age ranged from 63 to 78 years and 4 patients were male. Preoperative LV ejection fraction averaged 39 ± 3%. Chordal cutting was performed through aortotomy allowing comfortable access to the anterior mitral valve. Mitral effective regurgitant orifice at rest and at peak exercise was reduced by surgery (10 ± 3 to 0.6 ± 0.5 mm2 at rest and from 20 ± 3 to 6 ± 2 mm2 at peak exercise; p = 0.03). Mitral tenting area at rest and at peak exercise was concomitantly reduced by surgery (1.83 ± 0.21 cm2 to 0.50 ± 0.4 cm2 at rest and from 3.11 ± 0.58 to 1.7 ± 0.5 cm2 at peak exercise; p = 0.03). Left ventricular size and function remained unchanged after surgery. Conclusions: Chordal cutting through aortotomy may be an effective option to treat ischemic MR due to anterior leaflet tenting. Associated with myocardial revascularization, it resulted in a decrease of MR at rest and during exercise through a decrease in tenting area without impairment of LV function. [source]


    Morphologic Characteristics of the Left Atrial Appendage, Roof, and Septum: Implications for the Ablation of Atrial Fibrillation

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2006
    WANWARANG WONGCHAROEN M.D.
    Introduction: The left atrium (LA) ablation in different regions, including LA appendage (LAA), LA roof, and LA septum, has recently been proposed to improve the success rate of treating patients with atrial fibrillation (AF). The purpose of this study was to investigate the anatomy of LAA, LA roof, and LA septum, using computed tomography (CT). Methods and Results: Multidetector CT scan was used to depict the LA in 47 patients with drug-refractory paroxysmal AF (39 males, age = 50 ± 12 years) and 49 control subjects (34 males, age = 54 ± 11 years). The area of LAA orifice, neck, and the length of roof line were greater in AF group than in control subjects. Three types of LAA locations and two types of LAA ridges were observed. Higher incidence of inferior LAA was noted in AF patients. The different morphologies of LA roof were described. Roof pouches were revealed in 15% of AF and 14% of controls. Moreover, we found septal ridge in 32% of AF and 23% of controls. Conclusions: Considerable variations of LAA and LA roof morphologies were demonstrated. Peculiar structures, including roof pouches and septal ridges, were delineated by CT imaging. These findings were important for determining the strategy of AF ablation and avoiding the procedure-related complications. [source]


    Demonstration of Electrical and Anatomic Connections Between Marshall Bundles and Left Atrium in Dogs: Implications on the Generation of P Waves on Surface Electrocardiogram

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2002
    CHIKAYA OMICHI M.D.
    Marshall Bundle and P Wave.Introduction: The muscle bundles within the ligament of Marshall (LOM) are electrically active. The importance of these muscle bundles (Marshall bundle [MB]) to atrial activation and the generation of the ECG P wave is unclear. Methods and Results: We used optical mapping techniques to study epicardial activation patterns in isolated perfused left atrium in four dogs. In another seven dogs, P waves were studied before and after in vivo radiofrequency (RF) ablation of the connection between coronary sinus (CS) and the LOM. Computerized mapping was performed before and after RF ablation. Optical mapping studies showed that CS pacing resulted in broad wavefronts propagating from the middle and distal LOM directly to the adjacent left atrium (LA). Serial sections showed direct connection between MB and LA near the orifice of the left superior pulmonary vein in two dogs. In vivo studies showed that MB potentials were recorded in three dogs. After ablation, the duration of P waves remained unchanged. In the other four dogs, MB potentials were not recorded. Computerized mapping showed that LA wavefronts propagated to the MB region via LA-MB connection and then excited the CS. After ablation, the activation of CS muscle sleeves is delayed, and P wave duration increased from 65.3 ± 14.9 msec to 70.5 ± 17.2 msec (P = 0.025). Conclusion: In about half of the normal dogs, MB provides an electrical conduit between LA free wall and CS. Severing MB alters the atrial activation and lengthens the P wave. MB contributes to generation of the P wave on surface ECG. [source]


    Topographic Anatomy of the Inferior Pyramidal Space: Relevance to Radiofrequency Catheter Ablation

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2001
    DAMIÁN SÁNCHEZ-QUINTANA M.D.
    Inferior Pyramidal Space and Ablation.Introduction: Radiofrequency catheter ablation carried out in the vicinity of the triangle of Koch risks damaging not only the AV conduction tissues but also their arterial supply. The aim of this study was to examine the relationship of the AV nodal artery to the inferior pyramidal space, the triangle of Koch, and the right atrial endocardial surface. Methods and Results: We studied 41 heart specimens, 24 by gross dissections and 17 by histologic sections. The proximity of the AV nodal artery to the surface landmarks of the triangle of Koch was variable, but it was notable that in 75% of specimens the artery passed close to the endocardial surface of the right atrium and within 0.5 to 5 mm of the mouth of the coronary sinus. In all specimens, the mean distance of the artery to the endocardial surface was 3.5 ± 1.5 mm at the base of Koch's triangle. The location of the compact AV node and its inferior extensions varied within the landmarks of the triangle. At the mid-level of Koch's triangle, the compact node was medially situated in 82% of specimens, but it was closer to the hinge of the tricuspid valve in the remaining 18% of specimens. In 12% of specimens, the inferior parts of the node extended to the level of the mouth of the coronary sinus. Conclusion: The nodal artery runs close to the orifice of the coronary sinus, the endocardial surface of the right atrium, the middle cardiac vein, and the specialized conduction tissues in most hearts. The nodal artery and/or the AV conduction tissues can be at risk of damage when ablative procedures are carried out at the base of the triangle of Koch. [source]


    Typical Atrial Flutter Ablation: Conduction Across the Posterior Region of the Inferior Vena Cava Orifice May Mimic Unidirectional Isthmus Block

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2000
    MARCO SCAGLIONE M.D.
    Atrial Flutter Mapping. Introduction: The aim of this study was to map the low right atrium before and after radiofrequency ablation of the inferior vena cava-tricuspid annulus (IVC-TA) isthmus in patients with typical atrial flutter (AFI) to better understand the electrophysiologic meaning of incomplete or unidirectional block following the ablation procedure and its relationship with AFI recurrence. Methods and Results: We performed atrial mapping in 12 patients using a "basket" catheter in the IVC orifice, Halo catheter in the right atrium, and multipolar catheters in the coronary sinus (CS) and His region. In patients in sinus rhythm, atrial activation was analyzed during pacing from the CS and low lateral right atrium (KLRA) before and after ablation. Atrial activation propagated across the isthmus and posterior region of the IVC orifice simultaneously before ablation. Mapping during AFI in four patients showed that the crista terminalis was a site of functional block. After ablation, evaluation of Halo catheter recordings in three patients showed apparent unidirectional counterclockwise block, whereas analysis of basket catheter recordings demonstrated complete bidirectional block. The apparent conduction over the isthmus during pacing from proximal CS was due to conduction along the posterior part of the IVC orifice, which activated the LLRA despite complete isthmus block. Conclusion: Our results demonstrate that limited endocardial mapping may yield a pattern compatible with unidirectional block in the IVC-TA isthmus, although bidirectional block is present at this anatomic level. [source]