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Distal Segments (distal + segment)
Selected AbstractsHuman and climatic impact on late Quaternary deposition in the Sparta Basin Piedmont: Evidence from alluvial fan systemsGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 7 2003Richard J. J. Pope The evolution of four alluvial fans in the Evrotas Valley, southern Greece, was examined using a combination of geomorphological and sedimentological techniques. Source material for the fans is derived largely from the Taygetos Mountains, and thus the fan deposits provide proxy evidence for erosion of upland landscapes. Stratigraphic sequences exposed in the fanhead trenches suggest a progressive change in depositional style down-fan. Within the St. Johns, North Anogia, and North Xilocambi fans, debris flow deposits are gradually replaced by gravel-dominated hyperconcentrated flow deposits and then fine-grained hyperconcentrated flow deposits. Within the Kalivia Sokas fan, gravel-dominated hyperconcentrated flow deposits give way to fine-grained hyperconcentrated flow deposits, and finally to fluvial gravels. Mineral magnetic studies combined with thermoluminescence dating suggest that sedimentation also occurred over a similar time scale. Deposition cycles during the late Pleistocene appear to be climatically driven, with proximal and medial fan segments developing during stadial phases of the Riss/Würm and Würm, respectively. Distal segments aggraded during the Holocene. During interstadial episodes of the late Pleistocene, fan entrenchment occurred. Holocene accretion is likely to be related to human activity and appears to be concentrated in the early/middle Helladic and the Hellenistic periods, when population levels, indicated by increased numbers of archaeological sites, were rising. © 2003 Wiley Periodicals, Inc. [source] Endogenous BDNF is required for myelination and regeneration of injured sciatic nerve in rodentsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2000Jian-Yi Zhang Abstract Following a peripheral nerve injury, brain-derived neurotrophic factor (BDNF) and the p75 neurotrophin receptor are upregulated in Schwann cells of the Wallerian degenerating nerves. However, it is not known whether the endogenous BDNF is critical for the functions of Schwann cells and regeneration of injured nerve. Treatment with BDNF antibody was shown to retard the length of the regenerated nerve from injury site by 24%. Histological and ultrastructural examination showed that the number and density of myelinated axons in the distal side of the lesion in the antibody-treated mice was reduced by 83%. In the BDNF antibody-treated animals, there were only distorted and disorganized myelinated fibres in the injured nerve where abnormal Schwann cells and phagocytes were present. As a result of nerve degeneration in BDNF antibody-treated animals, subcellular organelles, such as mitochondria, disappeared or were disorganized and the laminal layers of the myelin sheath were loosened, separated or collapsed. Our in situ hybridization revealed that BDNF mRNA was expressed in Schwann cells in the distal segment of lesioned nerve and in the denervated muscle fibres. These results indicate that Schwann cells and muscle fibres may contribute to the sources of BDNF during regeneration and that the deprivation of endogenous BDNF results in an impairment in regeneration and myelination of regenerating axons. It is concluded that endogenous BDNF is required for peripheral nerve regeneration and remyelination after injury. [source] Endodontic and periodontal treatments of a geminated mandibular first premolarINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2002S. Aryanpour Abstract Aim, To describe a rare case of gemination involving a mandibular first premolar. Summary The complex morphology of geminated teeth renders their endodontic and periodontal management difficult. Root canal and periodontal treatments were performed on a geminated mandibular first premolar with three canals. Clinical examination showed two separated crowns with united roots. Radiographically, two distinct pulp chambers with two joined and a third independent canal were seen. Conventional root canal treatment resulted in complete healing of the apical lesion. However, the occurrence of a vertical fracture led to the extraction of the mesial segment. At the follow-up visit, the distal segment was clinically healthy and continued to satisfy functional demands. Key learning points ,Failure to diagnose the initial crack along a gemination groove resulted in further propagation and finally complete vertical fracture. ,Owing to the abnormal morphology of the crown and the complexity of the root canal system in geminated teeth, treatment protocols require special attention. ,For asymptomatic cases without aesthetic or orthodontic problems and without associated pathosis, routine review and careful maintenance are required. [source] Two new species of DiaphanosomaFischer, 1850(Crustacea: Branchiopoda: Cladocera) from the United StatesINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 2 2005Nikolai M. Korovchinsky Abstract Two new species of the genus Diaphanosoma,D. oligosetum and D. dorotheae, from Louisiana and North Carolina respectively, are described. The former species has large head with protruding dorsal part, large lanceolate spine on the basipodite's distal outer end, an extremely reduced number of antennal setae, up to six in adult specimens, and unique armament of valve margin. On the whole, it shows the pronounced combination of primitive and specialized morphological traits. D. dorotheae is a member of D. brachyurum species group differing from its other known representatives in presence of a small but very conspicuous spine on the end of proximal segment of antennal exopodite and a variable number of setae (seven or eight) on the distal segment of the branch. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Separation between the digestive and the respiratory lumina during the human embryonic period: morphometric study along the tracheo-oesophageal septumJOURNAL OF ANATOMY, Issue 1 2001JOSEP NEBOT-CEGARRA An isolated tracheo-oesophageal fistula could be caused by close proximity of the epithelia of both organs (O'Rahilly & Müller, 1984; Kluth et al. 1987) at certain embryonic stages, the most frequent location being the tracheal bifurcation. Thus the relative position and degree of separation between the digestive and the respiratory tubes throughout their development may be relevant to the origin of this anomaly. The aim of this study was to analyse along the different segments of the tracheo-oesophageal septum (TES) where the closest relationship between both lumina occurred and what degree of separation was present at each segment. Computer imaging techniques were applied on cross sections of a graded series of normal human embryos (Carnegie stages (CS) 13,23). In addition, the differentiation of the primitive TES was also studied (from CS 12) by light microscopy. Between CS 13 and 16 both tubes tended to separate (phase of separation), principally at the proximal segments of the laryngopharyngeal and the tracheo-oesophageal portions of the TES. During this phase the separation between the trachea and oesophagus was wider than between the larynx and pharynx. From CS 17 to CS 23 the digestive and respiratory lumina reached their widest separation at different levels of the laryngopharyngeal portion. Below these levels they tended to come closer together, principally at the proximal segment of the tracheo-oesophageal portion, but also at the distal part of the laryngopharyngeal portion. During this phase of approximation they reached their closest relationship at the proximal (CS 17) and the distal (from CS 18) segments of the tracheo-oesophageal portion. When finally the distal segment of the trachea (which includes the bifurcation) comes closest to the oesophagus, the coats of both organs have already undergone an appreciable differentiation. According to these observations, the origin of the most frequent isolated tracheo-oesophageal fistula at the bifurcation region could not be explained from the normal development of the TES. [source] Profile of P-glycoprotein distribution in the rat and its possible influence on the salbutamol intestinal absorption processJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2004Belén Valenzuela Abstract The intrinsic absorption of salbutamol in different intestinal segments of the rat was measured and related with the corresponding intestinal P-glycoprotein (P-gp) expression levels. The apparent absorption rate constants (ka, h,1) observed in each fraction by means of the "in situ" rat gut absorption method after perfusion of a 0.29-mM isotonic solution of salbutamol were used as absorption indexes. In a separate series of studies, a semiquantitative analysis of the mRNA expression of P-gp by means of polymerase chain reaction and Western blot with an antibody raised against the P-gp were also performed. The "in situ" ka values determined in the different segments (h,1) showed that the absorption is not homogeneous along the intestinal tract, that is, 0.499,±,0.054 for colon, 0.474,±,0.052 for the proximal segment, 0.345,±,0.014 for the mean, and 0.330,±,0.023 for the distal fraction. Addition of verapamil to the perfusion fluid did provide a better absorption of salbutamol in the distal segment. The analysis of the mRNA expression and levels of P-gp showed that the enzyme content in each section of the intestine was inversely related to salbutamol absorption. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1641,1648, 2004 [source] ELECTROPHYSIOLOGICAL ABNORMALITIES IN DIABETIC PATIENTSJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2000B. Lanzillo We studied 476 patients affected by diabetes: 166 male (mean age 61.6 ± 10 years, range 27,91) and 310 female (mean age 61.5 ± 8.4 years, range 25,82). Mean disease duration was 11.3 ± 7.6 years, range 0.3,37). All patients underwent surface motor and sensory nerve conduction along median, popliteal, and sural nerve. Results. Median nerve: in 3.1% of subjects sensory action potentials (SAP) was absent; sensory nerve conduction velocity (SNCV) was reduced in 41.8% in distal segment and in 27.5% in the proximal segment. Motor nerve conduction (MNCV) was reduced in 29.9% of the subjects. Sural nerve: SAP was absent in 24.4% and SNCV was reduced in 32.7%. Popliteal nerve: MNCV was abnormal in 30.4% of the subjects. Combining electrophysiological data we observed that: 1. 28.6% of the subjects resulted normal 2. 12.8% were affected by a lower limbs sensory neuropathy 3. 0.2% had a lower limbs motor neuropathy 4. 5.9% had a lower limbs sensory-motor neuropathy 5. 6.1% had a diffused sensory neuropathy 6. 30.2% had a diffused sensory-motor neuropathy 7. 16.2% had a carpal tunnel syndrome. Patients were divided in 2 groups: patients with and patients without neuropahy: the latter showed a significantly shorter disease duration (12.7 ± 8.1 vs 9.0 ± 6.3; p < 0.0001). In addition, we observed a significant correlation between disease duration and distal latency, median and popliteal MNCV, and SNCV in median and sural nerve (Regression test; p < 0.0001). Patients on insulin showed a longer disease duration and more severe electrophysiological abnormalities. [source] Divergent regulation of GIRK1 and GIRK2 subunits of the neuronal G protein gated K+ channel by G,iGDP and G,,THE JOURNAL OF PHYSIOLOGY, Issue 14 2009Moran Rubinstein G protein activated K+ channels (GIRK, Kir3) are switched on by direct binding of G,, following activation of Gi/o proteins via G protein-coupled receptors (GPCRs). Although G,i subunits do not activate GIRKs, they interact with the channels and regulate the gating pattern of the neuronal heterotetrameric GIRK1/2 channel (composed of GIRK1 and GIRK2 subunits) expressed in Xenopus oocytes. Coexpressed G,i3 decreases the basal activity (Ibasal) and increases the extent of activation by purified or coexpressed G,,. Here we show that this regulation is exerted by the ,inactive' GDP-bound G,i3GDP and involves the formation of G,i3,, heterotrimers, by a mechanism distinct from mere sequestration of G,,,away' from the channel. The regulation of basal and G,,-evoked current was produced by the ,constitutively inactive' mutant of G,i3, G,i3G203A, which strongly binds G,,, but not by the ,constitutively active' mutant, G,i3Q204L, or by G,,-scavenging proteins. Furthermore, regulation by G,i3G203A was unique to the GIRK1 subunit; it was not observed in homomeric GIRK2 channels. In vitro protein interaction experiments showed that purified G,, enhanced the binding of G,i3GDP to the cytosolic domain of GIRK1, but not GIRK2. Homomeric GIRK2 channels behaved as a ,classical' G,, effector, showing low Ibasal and strong G,,-dependent activation. Expression of G,i3G203A did not affect either Ibasal or G,,-induced activation. In contrast, homomeric GIRK1* (a pore mutant able to form functional homomeric channels) exhibited large Ibasal and was poorly activated by G,,. Expression of G,i3GDP reduced Ibasal and restored the ability of G,, to activate GIRK1*, like in GIRK1/2. Transferring the unique distal segment of the C terminus of GIRK1 to GIRK2 rendered the latter functionally similar to GIRK1*. These results demonstrate that GIRK1 containing channels are regulated by both G,i3GDP and G,,, while GIRK2 is a G,,-effector insensitive to G,i3GDP. [source] Effects of 6° elevation of the heels on 3D kinematics of the distal portion of the forelimb in the walking horseEQUINE VETERINARY JOURNAL, Issue 8 2004H. CHATEAU Summary Reasons for performing study: Understanding of the biomechanical effects of heel elevation remains incomplete because in vivo studies performed with skin markers do not measure the actual movements of the 3 digital joints. Objective: To quantify the effects of 6° heel wedge on the 3-dimensional movements of the 4 distal segments of the forelimb in the walking horse. Methods: Four healthy horses were used. Kinematics of the distal segments was measured invasively with a system based on ultrasonic triangulation. Three-dimensional rotations of the digital joints were calculated by use of a ,joint coordinate system' (JCS). Data obtained with heel wedges were compared to those obtained with standard shoes during the stance phase of the stride. Results: Heel wedges significantly increased maximal flexion of the proximal (PIPJ) and distal (DIPJ) interphalangeal joints and maximal extension (mean ± s.d. +0.8 ± 0.3°) of the metacarpophalangeal joint (MPJ). Extension of the PIPJ and DIPJ was decreased at heel-off. Few effects were observed in extrasagittal planes of movement. Conclusions: Heel wedges affect the sagittal plane kinematics of the 3 digital joints. Potential relevance: Controversial effects previously observed on the MPJ may be explained by the substantial involvement of the PIPJ, which was wrongly neglected in previous studies performed on the moving horse. [source] Identification of 2 putative critical segments of 17q gain in neuroblastoma through integrative genomicsINTERNATIONAL JOURNAL OF CANCER, Issue 5 2008Jo Vandesompele Abstract Partial gain of chromosome arm 17q is the most frequent genetic change in neuroblastoma (NB) and constitutes the strongest independent genetic factor for adverse prognosis. It is assumed that 1 or more genes on 17q contribute to NB pathogenesis by a gene dosage effect. In the present study, we applied chromosome 17 tiling path BAC arrays on a panel of 69 primary tumors and 28 NB cell lines in order to reduce the current smallest region of gain and facilitate identification of candidate dosage sensitive genes. In all tumors and cell lines with 17q gain, large distal segments were consistently present in extra copies and no interstitial gains were observed. In addition to these large regions of distal gain with breakpoints proximal to coordinate 44.3 Mb (17q21.32), smaller regions of gain (distal to coordinate 60 Mb at 17q24.1) were found superimposed on the larger region in a minority of cases. Positional gene enrichment analysis for 17q genes overexpressed in NB showed that dosage sensitive NB oncogenes are most likely located in the gained region immediately distal to the most distal breakpoint of the 2 breakpoint regions. Interestingly, comparison of gene expression profiles between primary tumors and normal fetal adrenal neuroblasts revealed 2 gene clusters on chromosome 17q that are overexpressed in NB, i.e. a region on 17q21.32 immediately distal to the most distal breakpoint (in cases with single regions of gain) and 17q24.1, a region coinciding with breakpoints leading to superimposed gain. © 2007 Wiley-Liss, Inc. [source] Comparison of Vasoactive Response of Left and Right Internal Thoracic Arteries to Isosorbide-Dinitrate and Nitroglycerin:JOURNAL OF CARDIAC SURGERY, Issue 4 2003An In Vitro Study Its distal region is, however, prone to vasospasm. We studied the effects of nitroglycerin (NTG) and isosorbide-dinitrate (DSDN) on distal segments of left versus right ITA. Methods: Rings of distal segments (6 to 9 mm proximal to bifurcation) of the human left and right ITA were studied. After baseline contraction of the rings, achieved using 60 mmol/L of KCl, they were exposed to increasing doses of ISDN and NTG (10 to 100 ,g/ml), and dose-response curves were recorded. Results: The contractile response of left ITA rings to KCl were significantly lower than those of right ITA rings (1.87 ± 0.25 g versus 3.5 ± 0.61 g, p < 0.005). Both nitrates inhibited the contractile response in a concentration-dependent manner, with relaxing effects of ISDN higher than those of NTG (p < 0.01) in both left and right ITA rings. Conclusions: The distal segment of the left ITA is less prone to vasospasm than that of the right. ISDN has a considerably higher relaxant effect on this segment than NTG. We therefore recommend favoring high doses of ISDN over NTG as an antispastic measure. (J Card Surg 2003; 18:279-285) [source] Effect of enamel matrix proteins (Emdogain®) on healing after re-implantation of "periodontally compromised" rootsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2003An experimental study in the dog Abstract Objective: The present experiment was performed to assess whether Emdogain® applied on the root surface of extracted teeth or teeth previously exposed to root planning can protect the tooth from ankylosis following re-implantation. Material and Methods: The experiment included two groups of dogs, including five animals each. The root canals of all mandibular third premolars (3 P 3) were reamed and filled with gutta-percha. A crestal incision was placed from the area of the second to the fourth premolar. Buccal and lingual full thickness flaps were elevated. With the use of a fissure bur, the crown and furcation area of 3 P 3 were severed in an apico-coronal cut. The distal and mesial tooth segments were luxated with an elevator and extracted with forceps. Group A: The mesial and distal segments of 3 P 3 were air dried on a glass surface for 60 min. The roots from the right side were conditioned and exposed to Emdogain® application. The roots from the left side received the same treatment with the exception of Emdogain® application. The mesial and distal tooth segments were re-implanted and the crown portions were severed with a horizontal cut and removed. The buccal and lingual flaps were mobilized and sutured to obtain complete coverage of the submerged roots. Group B: A notch was prepared in each root, 4,5 mm apical of the cemento-enamel junction. The area of the root that was located coronal to the notch was scaled and planned. The roots in the right side of the mandible were treated with Emdogain®, while the roots in the left side served as controls. After 6 months of healing, the dogs were killed and blocks containing one root with surrounding tissues were harvested, and prepared for histological examination, which also included morphometric assessments. Thus, the proportions of the roots that exhibited signs of (i) replacement (ii) inflammatory and (iii) surface resorption were calculated. Results and Conclusion: It was demonstrated that healing of a re-implanted root that had been extracted and deprived of vital cementoblasts was characterized by processes that included root resorption, ankylosis and new attachment formation. It was also demonstrated that Emdogain® treatment, i.e. conditioning with EDTA and placement of enamel matrix proteins on the detached root surface, failed to interfere with the healing process. Zusammenfassung Zielsetzung: Untersuchung, ob Emdogain®, wenn es auf die Wurzeloberfläche extrahierter Zähne oder von Zähnen, die zuvor eine Wurzelglättung bekommen haben, appliziert wird, die Zähne nach Reimplantation vor Ankylose schützen kann. Material und Methoden: Die Studie wurde bei 2 Gruppen von Hunden durchgeführt, die je 5 Tiere umfasste. Die Wurzelkanäle aller 3. Prämolaren des Unterkiefers (3 P 3) wurden aufbereitet und mit Guttapercha gefüllt. Ein Schnitt auf dem Limbus alveolaris wurde vom 2. zum 4 Prämolaren geführt. Bukkal und lingual wurde ein Vollschichtlappen mobilisiert. Mit einem Fissurenbohrer wurden die 3 P 3 mit einem Schnitt in koronoapikaler Richtung im Bereich der Krone und der Furkation geteilt. Die distalen und mesialen Zahnsegmente wurden mit einem Elevator luxiert und mit einer Zange extrahiert. Gruppe A: Die mesialen und distalen Segmente von 3 P 3 wurden auf einer Glasoberfläche 60 min lang luftgetrocknet. Die Wurzeln der rechten Seite wurden konditioniert und mit Emdogain® beschickt. Die Wurzeln der linken Seite erhielten die gleiche Behandlung mit der Ausnahme, dass keine Applikation von Emdogain® erfolgte. Die mesialen und distalen Wurzeln wurden reimplantiert und die Kronenanteile durch einen horizontalen Schnitt getrennt und entfernt. Die bukkalen und lingualen Lappen wurden mobilisiert und durch Naht ein vollständiger Verschluss der reimplantierten Wurzeln erreicht. Gruppe B: In jede Wurzel wurde 4,5 mm apikal der Schmelz-Zement-Grenze eine Kerbe präpariert. Der Bereich der Wurzel, der koronal dieser Kerbe lag, wurde gescalt und wurzelgeglättet. Die Wurzeln der rechten Unterkieferseite wurden mit Emdogain® behandelt, während die Wurzeln der linken Seite als Kontrolle dienten. Nach einer Heilung von 6 Monaten wurden die Hunde getötet und Blöcke, die eine Wurzel und das umgebende Gewebe enthielten, gewonnen und für die histologische Untersuchung präpariert, die auch morphometrische Befunde einschloss. Es wurden also die Anteile der Wurzeln berechnet, die Zeichen von (i) Ersatz- (ii) entzündlicher und (iii) Oberflächenresorption zeigten. Ergebnisse und Schlussfolgerungen: Es wurde gezeigt, dass die Heilung von reimplantierten Wurzeln, die extrahiert und von vitalen Zementoblasten befreit worden waren, durch Prozesse charakterisiert war, die Wurzelresorption, Ankylose und die Bildung neuen Attachments umfassten. Es wurde gezeigt, dass die Behandlung mit Emdogain®, d.h. Konditionierung mit EDTA und Applikation des Schmelz-Matrix-Proteins auf die freie Wurzeloberfläche diesen Heilungsprozess nicht beeinflussen konnte. Résumé Objectif: Cette expérimentation fut réalisée pour déterminer si Emdogain® appliqué sur la surface radiculaire de dents extraites ou de dents préalablement soumises à un surfaçage radiculaire pouvait protéger la dent de l'ankylose après réimplantation. Matériel et Méthodes: L'expérience comprenait 2 groupes de 5 chiens. Les canaux radiculaires de toutes les troisièmes premolaires mandibulaires (3 P 3) furent alésés et bouchés à la gutta-percha. Une incision crestale de la deuxième à la quatrième prémolaire permit de soulever un lambeau de pleine épaisseur vestibulaire et lingual. La couronne et la zone de furcation de 3 P 3 furent découpées à l'aide d'une fraise fissure d'apical en coronaire. Les segments distaux et mésiaux furent luxés avec un élévateur et extraits avec un davier. Groupe A: Les segments mésiaux et distaux de 3 P 3 furent séchés à l'air sur une plaque de verre pendant 60 min. Les racines du coté droit furent préparées et imprégnées d' Emdogain®. Les racines gauches reçurent le même traitement sans application d'Emdogain ®. Les segments mésiaux et distaux furent alors réimplantés et les couronnes découpées par un trait horizontal et éliminées. Les lambeaux vestibulaires et linguaux furent déplacés et suturés pour obtenir un recouvrement complet des racines enfouies. Groupe B: Une entaille a été préparée sur chaque racine, à 4,5 mm en apical de la jonction amélo-cémentaire. La surface de racine située coronairement à cette entaille fut alors détartrée et surfacée. Les racines du coté droit furent traitées par Emdogain® alors que les racines du coté gauche firent office de contrôle. Après 6 mois de cicatrisation, les chiens furent sacrifiés et des blocs contenant une racine et les tissus environnant furent prélevés pour un examen histologique et morphométrique. Ainsi, les proportions de racine présentant des signes de (i) remplacement (ii) d'inflammation et (iii) de résorption furent calculées. Résultats et conclusion: Nous avons démontré que la cicatrisation de racine réimplantées après extraction et élimination des cémentoblastes se caractérisait par un processus qui comprenait résorption radiculaire, ankylose et formation d'une nouvelle attache. Nous avons aussi démontré que le traitement par Emdogain®, c'est à dire conditionnement à l'EDTA et mise en place de protéines de la matrice améllaire sur la surface radiculaire, ne pouvait pas interférer avec le processus de cicatrisation. [source] Increased Dosage during Intracoronary Irradiation Due to Overlapped Source Stepping Shows No Long-Term Adverse Changes in Vessel MorphologyJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2004BONNI SYEDA M.Sc., M.D. Purpose: The purpose of this analysis was to evaluate if overdosage during intracoronary irradiation due to overlapped source stepping may result in long-term morphologic changes in vessel anatomy. Methods: Baseline angiograms of patients with in-stent restenosis undergoing coronary reintervention followed by intracoronary irradiation with source stepping were analyzed. Overlapping was considered present for the segment with overlapped reference isodose length (RIL) (RIL = segment with ,90% of reference dose at 1 mm vessel wall depth). Baseline and 6-months follow-up volumetric intravascular ultrasound (IVUS) analysis were performed for the overlapped segment and for proximal and distal segments of equal length. Results: Overlapping was found in six patients (three patients: 32P treatment; three patients: 90Sr/Y treatment); final analysis was performed in four patients. Comparison of the baseline and follow-up IVUS volumetric parameters revealed no significant change in lumen or vessel volumes at segments of overlaps in comparison to proximal and distal reference segments. Conclusion: Increased dosage due to overlapping during source stepping is not associated with morphologic changes in vessel anatomy at follow-up. (J Interven Cardiol 2004;17:143,149) [source] ROLE OF SURFACE WOUNDS AND BROWN ALGAL EPIPHYTES IN THE COLONIZATION OF ASCOPHYLLUM NODOSUM (PHAEOPHYCEAE) FRONDS BY VERTEBRATA LANOSA (RHODOPHYTA),JOURNAL OF PHYCOLOGY, Issue 3 2009Caroline M. Longtin Ascophyllum nodosum (L.) Le Jol. forms extensive beds in wave-sheltered, rocky intertidal habitats on the northwestern Atlantic coast. This fucoid seaweed is host to an obligate red algal epiphyte, Vertebrata lanosa (L.) T. A. Chr. [=Polysiphonia lanosa (L.) Tandy], and two facultative brown algal epiphytes, Elachista fucicola (Velley) Aresch. and Pylaiella littoralis (L.) Kjellm. Although V. lanosa can occur throughout most of the length of host fronds, it largely predominates in midfrond segments. The two brown algal epiphytes are restricted to distal segments. Through field experiments conducted in Nova Scotia, Canada, we tested the hypothesis that surface wounds are required for the colonization of distal segments of host fronds by V. lanosa. Distal tissues normally have a smooth surface because of their young age (A. nodosum fronds grow apically). By creating small wounds that mimicked grazing wounds distributed elsewhere on host fronds, we demonstrated that V. lanosa can colonize distal frond segments during the growth and reproductive season (summer and autumn). Approximately half of the artificial wounds were colonized by V. lanosa during this time. The experimental exclusion of both brown algal epiphytes from distal frond segments did not affect colonization by V. lanosa. Thus, we conclude that the absence of surface irregularities on distal segments of host fronds, specifically small wounds, is the main factor explaining the absence of V. lanosa there. We propose that further experimental work clarifying epiphyte distribution in host beds will enhance our ability to understand the functional role of epiphytes in intertidal ecosystems. [source] A New Simple Neurophysiological Method (Through Conventional Electrical Stimulation) To Assess Function Of Tactile Receptors And Related Nerve FibersJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2001L Padua Sometimes standard sensory nerve conduction studies show normal results in patients with definite symptoms of sensory polyneuropathy. This is usually explained because standard neurophysiological tests evaluate only large myelinated fibers and do not assess the slowest conducting fibers, more distal segments of the nerves and tactile receptors. Tactile stimulation is a test, not routinely available, that assesses the function of tactile receptors and conduction of fibers that are depolarized by these receptors. During conventional sensory nerve conduction studies (in patients and healthy subjects) through surface electrodes, where we slowly increased the intensity of the stimulus, we occasionally observed a sensory response characterized by a particular morphology with two peaks. After several experiments (performed in the neurophysiological laboratories of Catholic University of Rome and of University of Uppsala) we argued that the double component of the response is the expression of the stimulation of tactile receptors (and depolarization of their related fibers). Therefore an electrical stimulation through conventional EMG equipment allows us to assess function of tactile receptors (and related nerve fibers). This observation may have important diagnostic application in clinical practice to evaluate suspected polyneuropathies negative to neurophysiological conduction studies. [source] Protein fraction isolated from epididymal fluid re-associates sperm in vitro: Possible role of serpins in rat rosettes assemblyMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 5 2010María A. Monclus Abstract In many mammalian species, sperm associate as a consequence of the epididymal transit. From the classic Rouleaux in guinea pig to the most recent work in mouse and echidna, authors have focused mainly on a detailed morphological description of this phenomenon. Some of these articles have also begun to describe the nature of the material present between sperm heads. Here, we try to better understand the factor/s involved in rat sperm association (Rosette). Based on previous work describing the appearance of Rosettes in the distal segments of the rat epididymis, we consider that sperm during their transit must be in contact with factor/s present in the caudal lumen in order to associate with each other. By an in vitro sperm re-associating assay, we try to determine the in vivo phenomenon observed in the lumen. The assay consists of co-incubating non-associated sperm with several protein fractions obtained from epididymal caudal fluid. After establishing the most active fraction, the proteins were characterized by MALDI-TOF mass spectrometry. Among the proteins we found two members of the serine protease inhibitors family; an ,-1 antitrypsin and a new protein with an ,-1 antitrypsin like domain which includes a sequence compatible with the serpins' reactive center loop. These serpins may play a role in the assembly/disassembly process of Rosettes by modulating lumenal protease activity. Finally, a biochemical-morphological model which explains the sperm,proteases interaction was proposed. Mol. Reprod. Dev. 77: 410,419, 2010. © 2010 Wiley-Liss, Inc. [source] Secretin induces variable inhibition of motility in different parts of the Australian possum sphincter of OddiNEUROGASTROENTEROLOGY & MOTILITY, Issue 5 2001B. O. Al-Jiffry The sphincter of Oddi (SO) may not function as a single structure. We aimed to determine the response of the proximal and distal segments of the bile duct (BD-SO) and pancreatic duct (PD-SO) components of the SO to secretin, with and without neural blockade with tetrodotoxin (TTX). In anaesthetized Australian possums, separate manometry catheters were placed in the proximal and distal BD-SO or PD-SO segments to record motility. Secretin, 50,1000 ng kg,1, was administered, followed by TTX, and re-administration of secretin, 500 and 1000 ng kg,1. Changes in the motility index (MI, frequency × mean amplitude) were determined. Statistical analysis utilized repeated-measures ANOVA. Secretin produced a dose-dependent decrease in MI from the proximal and distal BD-SO and PD-SO (all P < 0.001). The maximum inhibition, at 1000 ng kg,1, was 21 ± 4%, 33 ± 6% and 42 ± 5% of control (mean ± SEM), for proximal and distal BD-SO, and distal PD-SO, respectively. The proximal PD-SO MI, however, was inhibited to 62 ± 6% of control, at 1000 ng kg,1. TTX enhanced the secretin-induced response to the same level at the four sites (P < 0.02). We conclude that secretin inhibits the motility of the possum SO in a nonuniform manner and is modulated by neural activity. [source] Allosyndetic recombinants of the Aegilops peregrina- derived Lr59 translocation in common wheatPLANT BREEDING, Issue 4 2010G. F. Marais With 2 figures and 2 tables Abstract The wild relatives constitute a valuable source of rust resistance genes that can be utilized in wheat breeding. However, translocation of desirable genes through chromosome engineering inevitably results in co-transfer of deleterious wild species chromatin. An attempt was made to replace such redundant alien chromatin on the Lr59 translocation through homoeologous chromosome pairing and crossing over in the absence of Ph1. Strong segregation distortion resulted in the recovery of an unexpectedly high frequency of resistant recombinants. Eight of these retained comparatively short, distal segments of foreign chromatin, including Lr59. The foreign chromatin that remained in the latter plants was characterized with the use of twelve anonymous AFLP loci, the data of which suggested reduced homoeology with 1AL that could have been the result of a sub-terminal, paracentric inversion. Crossing over within an inversion loop may have resulted in a low frequency of genetically unbalanced gametes. It will therefore be necessary to develop near-isogenic lines of the eight recombinants and to do field evaluations in order to identify those that retained the shortest, balanced translocations. [source] Relationships between morphological and sedimentological parameters in source-to-sink systems: a basis for predicting semi-quantitative characteristics in subsurface systemsBASIN RESEARCH, Issue 4 2009Tor O. Sømme ABSTRACT The study of source-to-sink systems relates long-term variations in sediment flux to morphogenic evolution of erosional,depositional systems. These variations are caused by an intricate combination of autogenic and allogenic forcing mechanisms that operate on multiple time scales , from individual transport events to large-scale filling of basins. In order to achieve a better understanding of how these mechanisms influence morphological characteristics on different scales, 29 submodern source-to-sink systems have been investigated. The study is based on measurements of morphological parameters from catchments, shelves and slopes derived from a ,1 km global digital elevation model dataset, in combination with data on basin floor fans, sediment supply, water discharge and deposition rates derived from published literature. By comparing various morphological and sedimentological parameters within and between individual systems, a number of relationships governing system evolution and behaviour are identified. The results suggest that the amount of low-gradient floodplain area and river channel gradient are good indicators for catchment storage potential. Catchment area and river channel length is also related to shelf area and shelf width, respectively. Similarly to the floodplain area, these parameters are important for long-term storage of sediment on the shelf platform. Additionally, the basin floor fan area is correlative to the long-term deposition rate and the slope length. The slope length thus proves to be a useful parameter linking proximal and distal segments in source-to-sink systems. The relationships observed in this study provide insight into segment scale development of source-to-sink systems, and an understanding of these relationships in modern systems may result in improved knowledge on internal and external development of source-to-sink systems over geological time scales. They also allow for the development of a set of semi-quantitative guidelines that can be used to predict similar relationships in other systems where data from individual system segments are missing or lacking. [source] Numerical distribution of lymphoid nodules in the human sigmoid colon, rectosigmoidal junction, rectum, and anal canalCLINICAL ANATOMY, Issue 2 2006Ivan L. Cameron Abstract There is little information on the numerical distribution of lymphoid nodules (LN) in distal segments of the human large bowel. A novel approach was therefore developed to assess the number of LN in the sigmoid colon, the rectosigmoid segment, the rectum, and the anal canal in humans. The distal large bowel from five cadavers was selected for quantitative study. The number of LN was scored macroscopically from the proximal sigmoid colon to the distal anal canal. A numerical distribution, previously unreported, consisting of two circular bands of LN was observed in each of the five cadavers. One band was located 3 cm proximal from the pectinate line and the other was located at the rectosigmoid segment. Significantly more LN occurred 3,5 cm proximal to the pectinate line compared to areas distal or proximal to this band of LN. This band of LN has not been reported previously in humans. Clin. Anat. 19:164,170, 2006. © 2006 Wiley-Liss, Inc. [source] Gender-Related Differences in Coronary Artery Dimensions: A Volumetric AnalysisCLINICAL CARDIOLOGY, Issue 2 2010Jennifer A. Dickerson MD Abstract Background Women consistently have poorer revascularization outcomes and more coronary vascular complications compared to men. This has been attributed to smaller coronary arteries, though limited data exist to support this assumption. Hypothesis By using volumetric data obtained from multidetector cardiovascular computed tomography (CCT), we sought to determine to what extent gender influences coronary artery dimensions and test the hypothesis that women would have smaller coronary dimensions even after normalizing for body surface area and cardiac mass. Methods CCT examinations completed on a 64-slice scanner were identified from a university cardiovascular database. Data sets from 50 women and 44 men without coronary artery disease were selected for analysis. Cross-sectional areas of proximal and distal segments of the left anterior descending (LAD), circumflex (LCx), and right coronary artery (RCA) were measured, blinded to patient gender. Measurements were compared using 2-sample t tests and linear regression analysis techniques accounting for body surface area (BSA) and left ventricular (LV) mass. Results Analysis of cross-sectional coronary artery areas, unadjusted for BSA and LV mass showed smaller coronary artery size in women compared to men in the proximal portion of both the LAD (P = .01) and RCA (P = .002), but no significant difference in the remaining coronary segments. Conclusion Gender significantly impacts proximal LAD and RCA size. Differences in coronary artery dimensions may explain some, but not all excess gender-related risk with coronary artery revascularization, underscoring the importance of considering multiple contributing factors. Copyright © 2010 Wiley Periodicals, Inc. [source] | ||||||||||||||||