Anatomical Structures (anatomical + structure)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Anatomical Structures

  • complex anatomical structure

  • Selected Abstracts

    Evolution of the nose and nasal skeleton in primates

    Timothy D. Smith
    Abstract One traditional diagnostic feature of the Order Primates is a decreased emphasis on olfaction.1, 2 Some authors attribute this feature only to tarsiers and anthropoids, either through convergence or as a common feature of haplorhines.2,4 Other authors de-emphasize olfaction relative to vision,5,7 which does not necessarily denote olfactory reduction per se. There are lengthy roots to this discussion. The importance of the sense of smell to at least some primates, humans in particular, has long been viewed as secondary to the importance of visual, auditory, and tactile senses. Smell, or olfaction, is viewed as the primitive special sense, the stimuli perceived in an unconscious manner, submerged relative to higher neural functions,1 and a sense that has been increasingly reduced during the course of primate evolution.1,8 Anatomical structures related to olfaction differ profoundly in proportions and complexity between higher taxonomic groups of primates (Haplorhini, Strepsirrhini). These anatomical differences are beyond dispute (Box 1). However, the relationship between the anatomical differences and primate sensory abilities, and hence the validity of using them to group primates into "microsmatic" or "macrosmatic" categories,9, 10 is less clear when we examine the physiological and genetic data on primate olfaction. [source]

    Automatic muscle generation for character skin deformation

    Xiaosong Yang
    Abstract As skin shape depends on the underlying anatomical structure, the anatomy-based techniques usually afford greater realism than the traditional skeleton-driven approach. On the downside, however, it is against the current animation workflow, as the animator has to model many individual muscles before the final skin layer arrives, resulting in an unintuitive modelling process. In this paper, we present a new anatomy-based technique that allows the animator to start from an already modelled character. Muscles having visible influence on the skin shape at the rest pose are extracted automatically by studying the surface geometry of the skin. The extracted muscles are then used to deform the skin in areas where there exist complex deformations. The remaining skin areas, unaffected or hardly affected by the muscles, are handled by the skeleton-driven technique, allowing both techniques to play their strengths. In order for the extracted muscles to produce realistic local skin deformation during animation, muscle bulging and special movements are both represented. Whereas the former ensues volume preservation, the latter allows a muscle not only to deform along a straight path, but also to slide and bend around joints and bones, resulting in the production of sophisticated muscle movements and deformations. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Magnetic resonance spectroscopy (MRS) and its application in Alzheimer's disease

    Pravat K. Mandal
    Abstract Magnetic resonance spectroscopy (MRS) is a noninvasive tool to measure the chemical composition of tissues (in vivo) and characterize functional metabolic processes in different parts of the human organs. It provides vital biological information at the molecular level. Combined with magnetic resonance imaging (MRI), an integrated MRI/MRS examination provides anatomical structure, pathological function, and biochemical information about a living system. MRS provides a link between the biochemical alterations and the pathophysiology of disease. This article provides a comprehensive description of the MRS technique and its application in Alzheimer's disease (AD) research. This review is a primer for students and researchers seeking a firm theoretical understanding of MRS physics as well as its application in clinical AD research. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 40,64, 2007. [source]

    Tufted stellate hairs in Valeriana tomentosa Kunth

    FEDDES REPERTORIUM, Issue 3-4 2009
    F. Weberling Professor Dr.
    In the general characteristics of the family Valerianaceae the occurrence of "stellate hairs" described by the authors of Valeriana tomentosa Kunth and V. malvaceae Graebn. still remains unconsidered. Beyond their diagnostic value, however, it is interesting, that at least the specific ontogeny and anatomical structure of the "stellate hairs" of V. tomentosa corresponds very well with similar trichomes known for several other taxa of Dipsacales, namely species of Viburnum (Viburnaceae) and some Dipsacaceae (Cephalaria, Scabiosa). (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Lesion development in stems of rough- and smooth-barked Eucalyptus nitens following artificial inoculations with canker fungi

    FOREST PATHOLOGY, Issue 3 2001
    Z. Q. Yuan
    A study of lesion development in stems of Eucalyptus nitens following artificial inoculations with canker fungi was carried out on 16-year-old plantation trees. In a first trial cambium bark wounds on smooth- and rough-barked trees were inoculated with the mycelium of nine species of canker fungi, including Endothia gyrosa. In a second trial spores or mycelium of E. gyrosa were applied directly onto undamaged or superficially wounded bark surfaces. Infection subsequent to artificial inoculation via wounding (whatever the wounding technique or type of inoculum) resulted in significantly larger external lesions (mean lesion area up to 35.6 cm2 20 months after inoculation) on smooth bark compared with those on rough bark (up to 19.0 cm2). Microscopic studies of infected rough and smooth bark suggest that, once smooth bark is compromised by wounding and artificial inoculation, the particular anatomical structure of smooth bark may offer less mechanical resistance to post-penetration hyphal spread in comparison with rough bark. It is suggested that at a pre-penetration stage under natural conditions spores of E. gyrosa more easily infect rough bark via cracks associated with this type of bark but not present in smooth bark. Développement des lésions sur les troncs d'Eucalyptus nitens àécorce lisse ou rugueuse, après inoculation par des champignons agents de chancre L'étude a été conduite en plantation sur des arbres de 16 ans. Dans un premier essai, des blessures de l'écorce jusqu'au cambium sur des arbres àécorce lisse ou rugueuse, ont été inoculées avec le mycélium de 9 espèces de champignons agents de chancre, dont Endothia gyrosa. Dans un deuxième essai, des spores ou du mycélium de E. gyrosa ont été appliqués directement sur l'écorce intacte ou blessée seulement superficiellement. Quel que soit la technique d'inoculation ou le type d'inoculum, l'infection a été plus importante extérieurement (surface moyenne jusqu'à 35,6 cm2 après 20 mois) chez les écorces lisses que chez les rugueuses (jusqu'à 19,0 cm2). L'étude microscopique des écorces infectées suggérait qu'à condition que l'écorce lisse soit impliquée dans la blessure, sa structure anatomique particulière offre moins de résistance mécanique à la post-pénétration mycélienne que l'écorce rugueuse. Il est suggéré qu'au stade de la pré-pénétration en conditions naturelles, les spores de E. gyrosa infectent plus facilement l'écorce rugueuse à la faveur des fissures qui sont présentes chez ce type d'écorce mais absentes chez les écorces lisses. Entwicklung von Läsionen am Stamm von rauh- und glattrindigen Individuen von Eucalyptus nitens nach künstlicher Inokulation mit krebserregenden Pilzen Es wurde die Entwicklung von Läsionen an Stämmen 16jähriger Eucalyptus nitens -Pflanzungen nach künstlicher Inokulation mit Krebserregern untersucht. In einem ersten Versuch wurden an rauh- und glattrindigen Bäumen Rindenwunden, die bis zum Kambium reichten, mit Myzel von neun Arten krebserregender Pilze, einschliesslich Endothia gyrosa, beimpft. In einem zweiten Versuch wurden Sporen oder Myzel von E. gyrosa direkt auf unverletzte oder nur oberflächlich verletzte Rinde aufgebracht. Künstliche Inokulation von Wunden (unabhängig von der Methode der künstlichen Verwundung oder der Art des Inokulums) führte zu signifikant grösseren, äusseren Wunden auf glatter (durchschnittliche Läsionsfläche 35.6 cm2 20 Monate nach Inokulation) als auf rauher Rinde (bis 19.0 cm2). Mikroskopische Untersuchungen zeigten, dass glatte Rinde gegen die Ausbreitung von Pilzhyphen mechanisch weniger resistent ist als rauhe Rinde. Unter natürlichen Bedingungen dürften dagegen Sporen von E. gyrosa Bäume mit rauher Rinde leichter durch vorhandene Rindenrisse infizieren, die bei glatter Rinde fehlen. [source]

    Recent Perspective on Coronary Bifurcation Intervention: Statement of the "Bifurcation Club in KOKURA"

    The treatment of coronary bifurcation lesion remains a challenging issue even in the drug-eluting stent era. Frequent restenosis and stent thrombosis have been recently shown to be related not only to geometrical gap or stent structural deformation but also to rheological disturbance. Low wall shear stress at the lateral side of the bifurcation is likely to cause atherosclerotic changes due to easy access of the macrophages that induce chemical mediators. The turbulent flow over stent metal may facilitate accumulation of platelets, which results in thrombosis. The jailed strut and excess metal overlap may increase these risks. Since dramatic changes of the coronary flow pattern at the bifurcation are closely related to the genesis of atherosclerosis, future bifurcation intervention technique should be considered to restore the original physiological state as well as the anatomical structure. This article summarizes the global consensus of the members of the Asian Bifurcation Club and European Bifurcation Club at the KOKURA meeting. It also provides a perspective of basic sciences relating to bifurcation anatomy, physiology, and pathology, in the search for a best strategy for bifurcation intervention. (J Interven Cardiol 2010;23:295,304) [source]

    Pacinian corpuscle in the juxtaoral organ of Chievitz

    Fumio Ide
    The juxtaoral organ of Chievitz (JOOC) is a normal permanent anatomical structure located within the soft tissue overlying the angle of the mandible in the buccotemporal space. Although the sensory organ nature of JOOC, repeatedly mentioned in German publications, has been neglected in the last decade by the American anatomists and pathologists, we incidentally found JOOC-type squamous epithelium accompanied by Pacinian corpuscles. This fortuitous finding appears to be the first report of the authentic Paciniform nerve endings within JOOC, supporting its mechanosensory function. [source]

    Detection of muscarinic receptor subtypes in human urinary bladder mucosa: Age and gender-dependent modifications,,§

    Nicola Arrighi
    Abstract Aims Muscarinic receptor subtypes expressed in the human urinary bladder mucosa were characterized, investigating whether there were gender-dependent differences and if aging could induce changes in their expression. Methods The study was carried out on 34 subjects, 22 men and 12 women, divided in four groups, based on gender and age. Gene expression was evaluated by quantitative RT-PCR. The Western blot was performed using the 4,12% NuPAGE Bis,Tris Gel System. Results The molecular expression of each subtype of the M1 receptor family was observed and it was not influenced either by gender or age. M2 receptor family transcripts revealed that both M2 and M4 were detected and that the M2 transcripts were modified by both gender and age. Indeed, M2 mRNA was lower in old rather than adult men (P,<,0.05), but higher in rather old than adult women (P,<,0.05). Further, adult men expressed more M2 mRNA than adult women (P,<,0.05), while the opposite was detected in old age (P,<,0.05). The Western blot followed by quantification confirmed that the mRNAs were translated into proteins, and that the M2 subtype showed similar modifications found at molecular level. Discussion The selective modification of M2 receptors observed at the urinary bladder mucosa levels indicates that this anatomical structure could play an active role in the pathophysiology of micturition and supports evidence suggesting an effect of antimuscarinic drugs at this level. Whether these results may influence the age-dependent development of micturition disorders remains to be determined. Neurourol. Urodynam. 27:421,428, 2008. © 2007 Wiley-Liss, Inc. [source]

    The plasma membrane Na+/H+ antiporter SOS1 is essential for salt tolerance in tomato and affects the partitioning of Na+ between plant organs

    PLANT CELL & ENVIRONMENT, Issue 7 2009
    ABSTRACT We have identified a plasma membrane Na+/H+ antiporter gene from tomato (Solanum lycopersicum), SlSOS1, and used heterologous expression in yeast to confirm that SlSOS1 was the functional homolog of AtSOS1. Using post-transcriptional gene silencing, we evaluated the role played by SlSOS1 in long-distance Na+ transport and salt tolerance of tomato. Tomato was used because of its anatomical structure, more complex than that of Arabidopsis, and its agricultural significance. Transgenic tomato plants with reduced expression of SlSOS1 exhibited reduced growth rate compared to wild-type (WT) plants in saline conditions. This sensitivity correlated with higher accumulation of Na+ in leaves and roots, but lower contents in stems of silenced plants under salt stress. Differential distribution of Na+ and lower net Na+ flux were observed in the xylem sap in the suppressed plants. In addition, K+ concentration was lower in roots of silenced plants than in WT. Our results demonstrate that SlSOS1 antiporter is not only essential in maintaining ion homeostasis under salinity, but also critical for the partitioning of Na+ between plant organs. The ability of tomato plants to retain Na+ in the stems, thus preventing Na+ from reaching the photosynthetic tissues, is largely dependent on the function of SlSOS1. [source]

    Reconstruction and Morphometric Analysis of the Nasal Airway of the Dog (Canis familiaris) and Implications Regarding Olfactory Airflow

    Brent A. Craven
    Abstract The canine nasal airway is an impressively complex anatomical structure, having many functional roles. The complicated branching and intricate scrollwork of the nasal conchae provide large surface area for heat, moisture, and odorant transfer. Of the previous anatomical studies of the canine nasal airway, none have included a detailed rendering of the maxilloturbinate and ethmoidal regions of the nose. Here, we present a high-resolution view of the nasal airway of a large dog, using magnetic resonance imaging scans. Representative airway sections are shown, and a three-dimensional surface model of the airway is reconstructed from the image data. The resulting anatomic structure and detailed morphometric data of the airway provide insight into the functional nature of canine olfaction. A complex airway network is revealed, wherein the branched maxilloturbinate and ethmoturbinate scrolls appear structurally distinct. This is quantitatively confirmed by considering the fractal dimension of each airway, which shows that the maxilloturbinate airways are more highly contorted than the ethmoidal airways. Furthermore, surface areas of the maxilloturbinate and ethmoidal airways are shown to be much different, despite having analogous physiological functions. Functionally, the dorsal meatus of the canine nasal airway is shown to be a bypass for odorant-bearing inspired air around the complicated maxilloturbinate during sniffing for olfaction. Finally, nondimensional analysis is used to show that the airflow within both the maxilloturbinate and ethmoturbinate regions must be laminar. This work has direct relevance to biomimetic sniffer design, chemical trace detector development, intranasal drug delivery, and inhalation toxicology. Anat Rec, 290:1325,1340, 2007. © 2007 Wiley-Liss, Inc. [source]

    Two novel neuropeptides in innervation of the salivary glands of the black-legged tick, Ixodes scapularis: Myoinhibitory peptide and SIFamide

    The peptidergic signaling system is an ancient cell,cell communication mechanism that is involved in numerous behavioral and physiological events in multicellular organisms. We identified two novel neuropeptides in the neuronal projections innervating the salivary glands of the black-legged tick, Ixodes scapularis (Say, 1821). Myoinhibitory peptide (MIP) and SIFamide immunoreactivities were colocalized in the protocerebral cells and their projections terminating on specific cells of salivary gland acini (types II and III). Immunoreactive substances were identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis: a 1,321.6-Da peptide with the sequence typical for MIP (ASDWNRLSGMWamide) and a 1,395.7-Da SIFamide (AYRKPPFNGSIFamide), which are highly conserved among arthropods. Genes encoding these peptides were identified in the available Ixodes genome and expressed sequence tag (EST) database. In addition, the cDNA encoding the MIP prepropeptide was isolated by rapid amplification of cDNA ends (RACE). In this report, we describe the anatomical structure of specific central neurons innervating salivary gland acini and identify different neuropeptides and their precursors expressed by these neurons. Our data provide evidence for neural control of salivary gland by MIP and SIFamide from the synganglion, thus lending a basis for functional studies of these two distinct classes of neuropeptides. J. Comp. Neurol. 517:551,563, 2009. © 2009 Wiley-Liss, Inc. [source]

    Two novel neuropeptides in innervation of the salivary glands of the black-legged tick, Ixodes scapularis: Myoinhibitory peptide and SIFamide

    Abstract The peptidergic signaling system is an ancient cell,cell communication mechanism that is involved in numerous behavioral and physiological events in multicellular organisms. We identified two novel neuropeptides in the neuronal projections innervating the salivary glands of the black-legged tick, Ixodes scapularis (Say, 1821). Myoinhibitory peptide (MIP) and SIFamide immunoreactivities were colocalized in the protocerebral cells and their projections terminating on specific cells of salivary gland acini (types II and III). Immunoreactive substances were identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis: a 1,321.6-Da peptide with the sequence typical for MIP (ASDWNRLSGMWamide) and a 1,395.7-Da SIFamide (AYRKPPFNGSIFamide), which are highly conserved among arthropods. Genes encoding these peptides were identified in the available Ixodes genome and expressed sequence tag (EST) database. In addition, the cDNA encoding the MIP prepropeptide was isolated by rapid amplification of cDNA ends (RACE). In this report, we describe the anatomical structure of specific central neurons innervating salivary gland acini and identify different neuropeptides and their precursors expressed by these neurons. Our data provide evidence for neural control of salivary gland by MIP and SIFamide from the synganglion, thus leading a basis for functional studies of these two distinct classes of neuropeptides. J. Comp. Neurol. 517:551,563, 2009. © 2009 Wiley-Liss, Inc. [source]

    REVIEW ARTICLE: Clinical Implication of Natural Killer Cells and Reproduction

    Joanne Kwak-Kim
    The regulation of natural killer (NK) cells in the peripheral blood and endometrial layers has been associated with reproductive immunopathology such as recurrent spontaneous abortions (RSA), infertility of implantation failures, or pre-eclampsia. The placenta has a complex anatomical structure and different subsets of NK cells with various functional roles can directly interact with trophoblasts. NK cell subpopulations and their functions, putative roles of NK cells in peripheral blood and endometrium are reviewed in relation to RSA and infertility. An increase in NK cell numbers and /or activity in pre- or post-conceptional period in women with RSA or infertility with multiple implantation failures are a significant clinical concern. In addition, immuno-phenotypic characteristics of NK cells in these women support the changes for their increased activity status. Further studies are needed to explore underlying mechanism of NK cells in RSA, infertility, and other reproductive immunopathologies. Possible neurological and hormonal control of NK cells and NK cell interaction with various leukocyte populations need further investigation in women with reproductive failures. [source]

    The anatomy of the perineal membrane: its relationship to injury in childbirth and episiotomy

    Christopher N Hudson
    ABSTRACT Background Episiotomy during childbirth, intended to protect the anal sphincter, may fail to do so. Furthermore damage to the anal sphincter complex may occur without complete perineal tear. We hypothesise that these particular injuries may occur due to posterior displacement of the anus leading to distraction of the anal sphincter complex from an anterior attachment to the perineal membrane. However, the anatomical basis for this has not been well defined. Objective To investigate the relationship between the anal sphincter and the perineal membrane. Materials and methods High-resolution MRI scans of a female cadaver perineum were performed. The imaging findings were correlated with the anatomical structure identified on dissection and histological examination. Results The perineal membrane was easily identified on MR imaging. Fibres from the perineal membrane could be seen to attach to the anal sphincter complex at the apex of the perineal body. This was confirmed on histological examination and was a deeper layer than that of the decussation of the superficial transverse perineal muscle with the superficial part of the external anal sphincter. Conclusion The upper ano-rectal canal and apex of the perineal body have demonstrable attachment to the free margin of the perineal membrane postero-lateral to the lower vagina. This attachment would resist posterior displacement of the anal canal. [source]

    Characterization of the anatomical extension pattern of localized prostate cancer arising in the peripheral zone

    BJU INTERNATIONAL, Issue 11 2010
    Mototsugu Muramaki
    Study Type , Diagnostic (non-consecutive series) Level of Evidence 3b OBJECTIVES To characterize the anatomical extension pattern of prostate cancer arising in the peripheral zone (PZ) in radical prostatectomy (RP) specimens and to evaluate its prognostic significance. PATIENTS AND METHODS Of 174 consecutive patients undergoing RP, 128 diagnosed as having PZ cancer (PZC) were enrolled. The maximum tumour area (MTA) and maximum tumour volume (MTV) in RP specimens were measured using digital planimetry. A circle with an area equal to the MTA, in which the central point was the intersection of the longest line of the MTA and the line perpendicularly bisecting the first line, was defined as a hypothetical extension area, regardless of anatomical structure. The area within this circle that did not overlap the MTA was defined as ,TA. RESULTS There was a significant correlation between the MTV and ,TA/MTA, introduced as a variable representing the degree of PZC extension along the anatomical shape of the PZ. The ,TA/MTA in patients with a MTV of >5 mL was significantly greater than that in those with a MTV of ,5 mL. Furthermore, ,TA/MTA was significantly associated with several prognostic indicators, including extracapsular extension, surgical margin status and perineural invasion. Multivariate analysis identified ,TA/MTA in addition to preoperative serum prostate-specific antigen level, extracapsular extension and surgical margin status as independent predictors of biochemical recurrence after RP. CONCLUSIONS PZC tends to extend along the anatomical shape of the PZ during progression, resulting in higher ,TA/MTA value in advanced PZC than that in early PZC. [source]

    2332: Pathological changes of anatomical structure and markers of limbal stem cell niche due to inflammation

    Purpose It's known that severe inflammatory processes may cause limbal stem cell (SC) deficiency decreasing the number of SC niches and changing the microanatomy of these structures. Methods The aim of this study was to evaluate the expression of different SC markers in normal human limbus and to study how an inflammatory conditions can modulate these antigens. To understand the pathological changes in limbal crypts structure due to severe inflammation, a case of corneal melting and perforation in advanced herpes simplex (HSV) disease, two cases of endophthalmitis and a case of fungal infection were analyzed.Samples were examined by immunohistochemistry or immunofluorescence for p63, vimentin, laminin5, integrin (Int) ,6, int ,1, int ,4, ABCG2, desmoglein 3, connexin43, N-cadherin and cytokeratin (K) 12 positivity. We evaluated the anatomical structure of limbal crypts in each case and the positivity for SC marker used to identify SC. Results In normal limbus, the investigated SC markers were positive. In the HSV we didn't observe presence of crypts, whereas in both cases of endophthalmitis crypts were still present but they had an atypical structure: the basal cells in the crypts were "stretched" and endowed by inflammatory cells. In the pathological cases, we observed positivity for K12 while, among SC markers, p63, ABCG2 and connexin43 were still present; the others antigens were variably expressed. Conclusion Different pathologies involving the limbus may result in marked chenges of expression of SC markers within the crypts. [source]

    In search for correlation among markers for limbal stem cells niche

    Purpose The corneoscleral limbus is known to be the site of corneal epithelial stem cells (SC). Several molecules have been proposed as SC markers but none of them is able to univocally identify them. The aim of this study was to evaluate co-expression of different SC markers in human limbus. Methods In this work five corneoscleral specimens from normal human donor eye-bank eyes (age 52-73 years) were fixed in formalin, divided in 8 segments, embedded in paraffin and examined by immunohistochemistry and immunofluorescence for p63, vimentin (vim), laminin 5, integrin (Int) ,6, Int ,1, Int ,4, connexin 43, ki67 and N-cadherin positivity. We firstly analyzed the distribution and the anatomical structure of limbal crypts in each of the segments. Then we evaluated the percentage of positive areas in the niches. Finally we looked for colocalizations and possible correlations among markers. Results We confirmed a different number of niches among the segments of the same corneoscleral rim. Moreover we observed high variability of niches number among patients which interestingly correlates with the percentage of p63 positivity of niche cells. Confocal microscopy double staining for p63 and vim did not show evident colocalization and vim + cells were seen in the superficial layers rather than in the deep layer of crypts. Int ,1 staining directly correlated with p63 positivity while the remaining proteins appeared variably and widely distributed Conclusion Colocalization was evident at least for two SC markers (Int ,1/p63) within the basal layers, while vim, expressed mainly in the superficial layers could act as late progenitor cell marker. [source]

    Characterization within and around the Limbal Epithelial Crypt

    Purpose: The Limbal Epithelial Crypt (LEC) is an anatomical structure that is found between the junction of the cornea and sclera and is in a unique position to make it an ideal structure to examine further. Previous studies have demonstrated the LEC to have properties that suggest it may be a stem cell niche. Basal cells of the LEC are significantly smaller than basal cells found in adjacent rete pegs, and morphologically they have a higher nuclear:cytoplasmic ratio. We set out to examine LEC further by exploring the surrounding LEC matrix proteins, and with known differentiation markers. Methods: Donated corneo-sclero rims were cut into eight equal sized pieces and frozen. Each piece was cut into 7,m serial sections, and was examined by microscopy for LEC structures. Identified LEC was collected on slides and stored until they were fixed in acetone and processed by standard immunofluorescence techniques for each differentiation marker. Results: Tenacin C was more positively taken up by the basement membrane of the LEC compared with the surrounding limbus. In addition, staining for desmoglein was negative against isolated small subpopulations of cells within the basal regions of the LEC. Conclusions: The LEC structure demonstrates properties that may identify this as a possible stem cell niche. Further studies are necessary to determine the significance of the LEC in its role in stem cell maintenance. [source]

    An enigmatic eye: the histology of the tuatara pineal complex

    Casey Y-J Ung MB BS (Qld)
    Abstract Aim: To examine the histology of the tuatara pineal complex and to compare findings wtih those of Dendy. Some reptiles have an anatomically sophisticated pineal complex with a median pineal eye, a paraphysis and a pineal sac. In comparison, the human pineal gland is simple and homogenous and thought to be a phylogenetic relic. It is now considered a neuroendocrine gland the function of which is still not fully understood. Its simple anatomical structure is in contrast to its biochemical complexity; its secretions (the most studied being melatonin) modifying the function of the adeno- and neurohypophysis, thyroid and parathyroids, adrenal cortex and medulla, endocrine pancreas and the gonads. Methods: Histological sections of the brain of a neonatal tuatara were studied by light microscopy. Results: The histological findings of the pineal eye demonstrated a cornea-like structure, rudimentary lens and simple retina. The adjacent paraphysis was a large, multisaccular organ and the pineal sac a very large saccular organ with a poorly differentiated retina. Conclusion: The pineal eye of the tuatara has a remarkably eye-like structure with photoreceptors that in other reptiles have been shown to exhibit photoreceptive capabilities. The paraphysis appeared to have a secretory function that is as yet undetermined, while the pineal sac had the appearance of a poorly differentiated retina. Thus it appears that the complex biochemistry of the human pineal gland is reflected in the complex anatomical structure of this primitive reptile. [source]

    Gross morphology of the vastus lateralis muscle: An anatomical review

    CLINICAL ANATOMY, Issue 4 2009
    Ines Becker
    Abstract To understand the role of the vastus lateralis (VL) muscle in the pathogenesis of common knee disorders such as patellofemoral joint syndrome, knowledge of its anatomical structure is essential. The aim of this study was to review currently available information on the gross morphology of VL. A structured literature review was undertaken and 36 references, comprising 22 scientific papers and 14 anatomical textbooks, were included. Results of this literature review show that most of the included studies exhibited methodological limitations, and focused on different parameters of the VL muscle. Hence, reproducibility of these studies and comparison of results was difficult. This review also demonstrates a dearth of information on the muscle architecture, compartmentalization, nerve supply and fusion of VL, and that there has been no investigation of the muscle as a whole unit. Further research is required of the architecture and innervation of the VL muscle to better understand its function. Clin. Anat. 22:436,450, 2009. © 2009 Wiley-Liss, Inc. [source]

    Sonographic detection of the optic radiation

    ACTA PAEDIATRICA, Issue 10 2005
    Annemieke Boxma
    Abstract Objective: To describe a region of hyperechoic white matter adjacent to the atrium of the lateral ventricle of preterms, and to speculate on the relevance of detecting preterm white matter injury. Patients and methods: Cranial ultrasound images of 92 preterms of gestational age (GA) 32 wk or less were reviewed. For each infant, one first week standard coronal image was used for measurement of grey values around the para-atrial region of interest (PAROI) relative to the choroid plexus. For verification of the sonographic anatomy, MR images of an adult brain were used. For reference, neuro-anatomical images were compared in several atlases. In a group of nine preterms of similar GA with cystic periventricular leukomalacia (PVL) or MR-confirmed white matter disease, the disappearance of the PAROI was examined. Results: The hyperechoic para-atrial area, subjectively detected in 84% of the patients, was situated bilaterally between the inner end of the lateral fissure and the upper third of the choroid plexus. In white matter caudal to the atrium, the hyperechoic band could be pursued towards the calcarine area. The average ratio of grey value around the PAROI to the choroid plexus was 0.787 (SD=0.072, median 0.791). There was no correlation between PAROI grey value and gestational age. At 26 wk gestational age, the average ratio was 0.781 (n=14), and 0.789 (n=17) at 31 wk. Location of the PAROI agrees with the angle of the upper loop of the optic radiation. None of the nine infants with white matter damage had PAROIs clearly distinguishable from flaring. Conclusion: The symmetrical and unchanged acoustic character between 26 and 31 wk of gestational age argues in favour of the hypothesis that the PAROI is an anatomical structure. The localization of the hyperechoic band supports the hypothesis that it represents part of the optic radiation. Further study is needed to examine the absence of a hyperechoic para-atrial band as a prognostic marker of the extension and severity of white matter injury. [source]

    Intracardiac Echocardiography in Patients with Pacing and Defibrillating Leads: A Feasibility Study

    ECHOCARDIOGRAPHY, Issue 6 2008
    Maria Grazia Bongiorni M.D.
    Background: Lead extraction, an important and necessary component of treatment for many common device and lead-related complications, is a procedure that can provoke much anxiety in even the most experienced operators given the potentially serious complications. The principal impediment to lead extraction is the body's response to an intravascular foreign body with matrix intravascular neoformation, which causes the lead to adhere to the endocardium or vascular structure, increasing the risk of vascular or myocardial damage with lead removal. Fluoroscopic visualization, the commonly visualization used tool, has several limits in terms of anatomical structures visualization. The aim of this study was to assess the safety and feasibility of intracardiac echocardiography (ICE) in patients undergoing pacing and defibrillating leads before and during a transvenous device removal, and its potential role in detecting intracardiac leads and areas of fibrous adherence. Methods: ICE interrogation was performed in 25 consecutive patients with pacing and defibrillating implantable cardioverter defibrillators (ICD) leads before and during device removal. Results: A programmed ICE analysis was completed in 23 out of 25 patients with excellent resolution, providing a "qualitative-quantitative" information on anatomical structures, cardiac leads, and related areas of fibrous adherence. No ICE-related complications occurred. Conclusions: ICE evaluation is safe and feasible in patients with pacing and defibrillating leads before and during transvenous lead removal, offering an excellent visualization of cardiac leads and related areas of adherence. ICE can assist pacing and ICD lead removal and could improve procedure efficacy and safety. [source]

    Reconstruction of the main portal vein for a large saccular aneurysm

    HPB, Issue 3 2003
    Vojko Flis
    Background A large aneurysm of the main portal vein is rare, and the appropriate surgical procedure is uncertain. Reconstruction of a main portal vein affected by a large saccular aneurysm is described. Case outline Abdominal pain led to the diagnosis of a large saccular aneurysm of the main portal vein in a 58-year-old woman who had undergone cholecystectomy 10 years earlier. At laparotomy a dorsolateral approach to the hepatoduodenal ligament was performed with no attempt at extensive separate exposure of the anatomical structures in the hepatoduodenal ligament, so as to avoid the devascularisation of the common hepatic duct and additional weakening of the portal vein wall. The aneurysm was longitudinally incised, and the portal vein was reconstructed from the walls of the aneurysm with a longitudinal running suture. The rest of the aneurysmal wall was wrapped around the portal vein, leaving it normal in size and contour. Recovery was uneventful. Follow-up CT scan showed a patent portal vein in the region of the former aneurysm. Discussion Large saccular aneurysms can rupture, bleed and cause death. The potential hazards of manipulation of large portal vein aneurysms are negligible in comparison with the possible complications of the aneurysm itself. In our opinion the ease with which the main portal vein was dissected and reconstructed make an elective operation in such cases a reasonable approach. [source]

    Prenatal and early postnatal morphogenesis and growth of human laryngotracheal structures

    JOURNAL OF ANATOMY, Issue 2 2008
    Pierre Fayoux
    Abstract Advances in neonatal medicine have resulted in increased care of fetal and neonatal airways. These advances have required an exhaustive knowledge of fetal airway anatomy and development. The aim of this study was to determine the anatomical development of laryngotracheal structures during the fetal and immediate postnatal period and to correlate these observations with other fetal biometric parameters to estimate developmental particularities of the fetal airway. An anatomical prospective study was based on examination of larynx and trachea from 300 routine autopsies of fetuses and infants, free of malformation and never intubated. Anatomical measurements of cricoid cartilage, thyroid cartilage, glottis, arytenoid cartilage and trachea were performed using a precision calliper and precision divider. Statistical analysis was performed to represent the growth of anatomical structures and to evaluate the correlation with biometric data. Raw data and 10th and 90th percentile curves were fitted satisfactorily with a linear model for gestational age. A linear relationship between laryngotracheal measurement and body weight and height was observed except for glottis length, interarytenoid distance and anterior cricoid height. The diameter of the cricoid lumen was significantly less than that of the trachea and glottis lumen. A sexual dysmorphism was noted for thyroid cartilage measurements and interarytenoid distance, with measurements significantly smaller in females. This study reports the anatomical development of normal laryngotracheal structures during the fetal period. Despite the fact that this study was performed during postmortem examination, these observations can be useful to develop criteria, materials and surgical procedures adapted to fetal and neonatal airways as well as for the purposes of early diagnosis and management of laryngotracheal malformations. [source]

    Volumetric analysis of extraction sockets using cone beam computed tomography: a pilot study on ex vivo jaw bone

    Jimoh Olubanwo Agbaje
    Abstract Aim: The aim of this study was to determine the accuracy of volumetric analysis of extraction sockets using cone beam computed tomography (CBCT). Material and Methods: The volume of 40 dental alveoli in nine dry skull specimens (four mandibles and five maxillae) was determined by measuring the volume of the tooth socket impression using the water displacement technique. This was considered as the gold standard. Then, the tooth socket was scanned with CBCT and data were uploaded in the semi-automated Livewire® segmentation software. The software segments the tooth socket in consecutive 1 mm-thick two-dimensional slices. After segmentation, the total volume of the delineated socket was computed. The statistical difference between direct volumetric measurements and those obtained with CBCT imaging was assessed using the Student paired t -test. Result: The mean socket volume of the skull specimens was 227±91 mm3 when obtained by direct measurement and 225±90 mm3 when obtained by CBCT imaging. Student paired t -test showed no significant differences between both volume measurements (p>0.1). Conclusions: CBCT permits imaging of anatomical structures in three planes and allows for reliable volume estimates. The results should be verified in clinical circumstances and might have potential applicability for evaluation of extraction socket healing under different conditions. [source]

    Pathology associated with retained fishing hooks in blue sharks, Prionace glauca (L.), with implications for their conservation

    J Borucinska
    Fishing hooks retained from previous capture events were found in 6 of 211 blue sharks, Prionace glauca (L.), landed in the summers of 1999 and 2000 by recreational fishermen off Long Island (New York, USA). The hooks were embedded within the distal oesophagus (n=3), or perforated the gastric wall (n=3) and lacerated the liver (n=2). The hooks were surrounded by excessive fibronecrotic tissue which ablated the normal anatomical structures and in the three sharks with oesophageal hooks caused partial luminal obstruction. Accompanying lesions included oesophagitis, gastritis, hepatitis and proliferative peritonitis. Aeromonas sp. and Vibrio sp. were isolated from the peritoneal fluid of one shark with peritonitis and intralesional bacteria were seen on histological examination in all sharks. This is the first report of the prevalence and pathology of retained fishing hooks in a large number of wild-caught sharks. [source]

    Larynx morphology and sound production in three species of Testudinidae

    Roberto Sacchi
    Abstract Although the ability to vocalize is widespread among tortoises, the mechanisms of sound production in chelonians remain undescribed. In this study, we analyze the morphology and histology of the larynx of three species of Testudinidae (Testudo hermanni, T. graeca, and T. marginata) in order to ascertain the presence of vibrating acoustic structure, and based on our findings we propose a general model for phonation in tortoises. The structure of the larynx of the three tortoises analyzed is simple: three cartilages (the cricoid and two arytenoids) form the skeleton of the larynx, while two pairs of muscles (the dilators and constrictors) control the widening and closing of the glottis. The larynx is supported in the oral cavity by the hyoid cartilage, which in tortoises assumes the same functions of the thyroid cartilage of mammals. Two bands of elastic fibers are inserted in the lateral walls of the larynx just upstream of the glottis, and can be stretched away from the hyoid by the movements of the arytenoids. Their position and structure suggest that these bands are capable of vibrating during exhalation, and therefore may be considered vocal cords. The cricoid of T. marginata and T. graeca hold two diverticula, not previously reported, which might function as a low-frequency resonating chamber, improving the harmonic structure of tortoise calls. The structure of the larynx is compared with that of other vertebrates and the relationships between morphology and phonation are discussed. This is the first detailed description of anatomical structures possibly devoted to vocalization in chelonians. J. Morphol. 261:175,183, 2004. © 2004 Wiley-Liss, Inc. [source]

    Origin of evolutionary novelty: Examples from limbs

    Neil H. Shubin
    Abstract Classic hypotheses of vertebrate morphology are being informed by new data and new methods. Long nascent issues, such as the origin of tetrapod limbs, are being explored by paleontologists, molecular biologists, and functional anatomists. Progress in this arena will ultimately come down to knowing how macroevolutionary differences between taxa emerge from the genetic and phenotypic variation that arises within populations. The assembly of limbs over developmental and evolutionary time offers examples of the major processes at work in the origin of novelties. Recent comparative developmental analyses demonstrate that many of the mechanisms used to pattern limbs are ancient. One of the major consequences of this phenomenon is parallelism in the evolution of anatomical structures. Studies of both the fossil record and intrapopulational variation of extant populations reveal regularities in the origin of variation. These examples reveal processes acting at the level of populations that directly affect the patterns of diversity observed at higher taxonomic levels. J. Morphol. 252:15,28, 2002. © 2002 Wiley-Liss, Inc. [source]

    Using a cross section to train veterinary students to visualize anatomical structures in three dimensions,

    Judy Provo
    A cross section was used to enhance three-dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n,=,124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test,retest reliability. A live-dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed. © 2002 John Wiley & Sons, Inc. J Res Sci Teach 39: 10,34, 2002 [source]

    Scaling of plantar pressures in mammals

    JOURNAL OF ZOOLOGY, Issue 3 2009
    F. Michilsens
    Abstract The interaction of the limbs with the substrate can teach a lot about an animal's gait mechanics. Unlike ground-reaction forces, plantar pressure distributions are rarely studied in animals, but they may provide more detailed information about the loading patterns and locomotor function of specific anatomical structures. With this study, we aim to describe pressures for a large and diverse sample of mammalian species, focusing on scaling effects. We collected dynamic plantar pressure distributions during voluntary walking in 28 mammal species. A dynamic classification of foot use was made, which distinguished between plantiportal, digitiportal and unguliportal animals. Analysis focused on scaling effects of peak pressures, peak forces and foot contact areas. Peak pressure for the complete mammal sample was found to scale to (mass)1/2, higher than predicted assuming geometric similarity, and we found no difference between the different types of foot use. Only the scaling of peak force is dependent on the dynamic foot use. We conclude that plantar peak pressure rises faster with mass than expected, regardless of the type of foot use, and scales higher than in limb bones. These results might explain some anatomical and behavioural adaptations in graviportal animals. [source]