bluuebunny/crossref_metadata_2025_split huggingface dataset:
INSERTION OF METALLIC STENTS FOR MALIGNANT GASTRIC OUTLET AND DUODENAL STENOSES
Authors: Uno Koji , Tanaka Kiyohito , Cho Eisai , Yasuda Kenjiro , Nakajima Masatsugu 
Published: July 2004

ABSTRACTRecently, an indication of gastrointestinal stenting is not only esophageal stenosis but it extends from the esophagus to the gastric outlet and duodenum. However, there are some problems such as shortness of the device for esophageal stenting, angulations of stenotic sites, and so on, when we perform the stenting for stenoses of the gastric outlet and duodenum. Until now, some refinements of stent insertion technique have been attempted to solve these problems. In this paper, we report three cases in which self‐expanding metallic stents were placed for stenoses of the gastric outlet and duodenum with refinements of stent insertion technique. Our attempts in these patients were an extension of stenting device to insert stents easily, and placement of covered metallic stent inside non‐covered metallic stent or a fixation of covered metallic stent to the gastrointestinal wall by means of endoclips to avoid dislocation of stents. Stents were inserted successfully in all patients, and the nutrition of these patients was improved after the placement of stents. Further refinements of stents and stent insertion technique are expected to achieve easy manipulation.
IS IT DIFFICULT FOR ENDOSCOPISTS WHO HAVE DONE CONVENTIONAL ENDOSCOPIC MUCOSAL RESECTION TO PERFORM SUBMUCOSAL DISSECTION?
Authors: Yagi Kazuyoshi , Nakamura Atsuo , Sekine Atsuo 
Published: July 2004

ABSTRACTSubmucosal resection is a very useful method of endoscopic mucosal resection (EMR) for en bloc resection. We began using this method in March 2003 and have resected lesions in 16 patients with gastric cancer. We describe the procedure times and complications associated with submucosal resection from a beginner's point of view. Our first five patients experienced bleeding and perforation. With the aid of a range of instruments and the advice of expert endoscopists, our complication rate became very low and the procedure time much shorter. Endoscopists who seek to perform submucosal dissections easily and safely should avail themselves of training and education from experts in the method. A program for training endoscopists in submucosal dissection is essential.
A STUDY OF PHYSICAL EFFICACY OF DIFFERENT SNARES FOR ENDOSCOPIC MUCOSAL RESECTION
Authors: Yamano Hiro‐o , Matsushita Hiro‐o , Yamanaka Kousei , Maeda Satoshi , Nakazato Masaru , Sato Kentaro , Fujita Kazuhiko , Satake Shinya 
Published: July 2004

ABSTRACTThere are various types of snares for endoscopic mucosal resection (EMR). Some endoscopists may choose the snare according to their feeling, but we supposed that there were some physical reasons behind each choice. In this paper, we raise the questions, ‘What is the best snare chosen for EMR?’, and ‘Why do we have to do it?’. From the theory of dynamics, we thought that the most important element was vertical force, which we could add against mucosa through the snare. First, we made two situations; one was keeping horizontal faced position of loop of snare (we defined it as HPW; horizontal faced position weight), and the other was rising up position of it (we defined it as RPW). We inspected these forces for the representative and different seven snares, and calculated the ‘Effective Range’, which was a RPW minus a HPW in average. The results demonstrated that both the spiral snare and the smaller ‘Snare Master’ showed higher than other snares in HPW, RPW, and the Effective Range. Based on our study, we judged them as the most adequate snares for EMR in physics and logicality.
STANDARD IMAGING TECHNIQUES IN THE PANCREATOBILIARY REGION USING RADIAL SCANNING ENDOSCOPIC ULTRASONOGRAPHY
Authors: Inui Kazuo , Kida Mitsuhiro , Fujita Naotaka , Maguchi Hiroyuki , Yasuda Kenjiro , Yamao Kenji 
Published: July 2004

ABSTRACTStandard imaging techniques using a radical scanning echoendoscope are summarized to facilitate the attainment of expertise in biliopancreatic endoscopic ultrasonography and to promote the widespread use of this diagnostic tool. Typical images of the biliopancreatic system and neighboring organs obtained by scanning from the stomach, duodenal bulb, and descending portion of the duodenum are shown in a sequential manner. Two methods of scanning from the descending portion of the duodenum, which is considered to be the most difficult, are presented (i.e. the Longitudinal Method and the Transverse Method). In addition, settings of the image control functions and the monitor are also detailed.
ENDOSCOPIC MANAGEMENT OF BILIARY STRICTURES
Authors: Kubota Yoshitsugu 
Published: July 2004

ABSTRACTEndoscopic stenting, due to being less invasive, is feasible for most patients with biliary strictures; however, presumed efficacy should be balanced against the procedure‐related morbidities for an individual patient. Self‐expandable metallic stents have a longer patency, but are not retrievable. Therefore, the use of self‐expandable metallic stents should be limited to those with unequivocal findings of unresectable malignancy. Plastic stents are indicated for strictures due to benign etiologies and equivocal malignancy. Endoscopic stenting for hilar biliary stricture is challenging. Bilateral hepatic drainage seems ideal but is often demanding to achieve with endoscopic technique, and contrast injection into undrained segments may pose a substantial risk for cholangitis and aggravate prognosis. Therefore, the extent of drainage should be balanced against the procedure‐related complications. Preoperative magnetic resonance cholangiopancreatography may help determine feasibility of bilateral drainage or an ‘intended and selective drainage’ with a single stent and might obviate the possible morbidities.
STRATEGY FOR CLINICAL MANAGEMENT OF BENIGN BILIARY STRICTURES
Authors: Aiura Koichi , Imaeda Hiroyuki , Kumai Koichiro 
Published: July 2004

ABSTRACTBenign biliary strictures (BBS) can present serious challenges in clinical management. We present a strategy for selecting therapeutic approaches to BBS based on our institute experience. Stricture etiology is important for developing a treatment plan, as it often determines the anatomical sites and structure of the stricture. If the initial passage of a guidewire through the stricture fails, surgical correction becomes the only option. Otherwise, non‐surgical endoscopic procedures such as percutaneous transhepatic or transpapillary balloon dilation with or without stent insertion provides a good outcome in most cases. However, patients with BBS of Bismuth type III/IV or those due to pancreatitis tend to present more difficulty for successful treatment by endoscopic procedures. The placement of double stents across the stricture may be beneficial to maintain greater diameter after dilation. In addition, endoscopic sphincterotomy required for stent emplacement could increase the chance of reflux cholangitis, especially in patients with bile duct strictures.
PLASTIC STENT PLACEMENT FOR UNRESECTABLE MALIGNANT BILIARY STRICTURE
Authors: Ito Kei , Fujita Naotaka , Noda Yutaka , Kobayashi Go , Kimura Katsumi 
Published: July 2004

ABSTRACTBackground:  Endoscopic stent placement is an efficacious treatment for patients with malignant biliary stricture. We investigated the indications for plastic stent placement in patients with unresectable malignant biliary stricture.Patients and methods:  Eighty‐three patients with unresectable malignant biliary stricture who had undergone endoscopic placement of either a plastic stent or a covered metal stent in our department between February 1997 and September 2002 were reviewed retrospectively.Results:  Metal stents had significantly longer patency (273 ± 99 days) than plastic stents (155 ± 52 days) (P = 0.0292). The two groups showed similar patency curves up to 150 days.Conclusions:  The indication for plastic stent placement as palliative therapy for unresectable malignant biliary stricture is drainage for patients with an expected survival of less than 5 months.
Changes in the expression of angiotensin II type 1 receptor in the development of liver fibrosis
Authors: WANG Wei Wei , YANG Xi Shan , LI Xu , WANG Jie , TIAN Ye , YANG Chuan Hong , LAI Huang Wen 
Published: July 2004

OBJECTIVE:  To detect the expression of angiotensin II type 1 receptor (AT1R) in the different stages of human liver fibrosis.METHODS:  The morphology and ultrastructure of hepatic stellate cells (HSC) in hepatic sinusoids were studied by transmission electron microscopy, collagen I (col I) was tested by immunohistochemical method, an indirect immunofluorescence labeling method was used to detect AT1R, and semiquantitative RT‐PCR was used to detect AT1R mRNA.RESULTS:  Positive expression of AT1R was mainly distributed in the periphery of hepatic lobules and in the cytoplasm of HSC in the sinusoids. In normal liver tissue from 12 cases, positive expression of AT1R was seen in 8, whereas in 18 fibrotic livers, all showed positive expression. Cells that positively expressed AT1R were significantly more abundant in the fibrotic liver group than in the normal liver group (P < 0.001), and were significantly increased with an increase in the collagenous surface area. The relative expression level of AT1R mRNA in the fibrotic liver group was also higher than in the normal liver group (P < 0.01).CONCLUSIONS:  The expressions of both AT1R and AT1R mRNA increased significantly with the degree of liver fibrosis, so angiotensin II and its receptor are probably important in the development of liver fibrosis.
Categorization of dysmotility in patients with chronic constipation and its significance for management
Authors: GUO Xiao Feng , KE Mei Yun , WANG Zhi Feng , FANG Xiu Cai , WU Bing , TU Yin Ping 
Published: July 2004

BACKGROUND:  Chronic constipation is a common gastrointestinal symptom with different patterns of dysmotility for which there is not one simple and effective diagnostic method for categorization. The present study assessed the diagnostic method used in patients with chronic constipation and its significance for clinical management.METHODS:  The study group comprised 210 consecutive patients with chronic constipation who underwent history, digital anorectal examination (DARE), gastrointestinal transit test (GITT) and anorectal manometry (ARM) to determine the pattern of dysmotility. Symptoms and the examinations were summarized for establishing the diagnostic method and evaluation of the role of the examinations.RESULTS:  Outlet obstructive constipation (OOC), slow transit constipation (STC) and mixed constipation (MC) accounted for 50.8%, 10.2% and 39.0% of cases, respectively. The stool was harder in STC or MC than in OOC (P = 0.036). The presence of a paradoxical inverse contraction of anal sphincter when straining to defecate during DARE or ARM was significant for the diagnosis of OOC (P < 0.001). The distribution of the residual markers on abdominal plain film after 48 h GITT was significant for the diagnosis of STC (P < 0.001). The sensitivity of DARE, GITT and ARM was 82.5%, 89.1% and 94.4%, and specificity was 95.2%, 87.9% and 82.6%, respectively. Clinical management was modified in 69.5% of patients after categorizing the constipation pattern.CONCLUSIONS:  The symptoms, DARE, GITT and ARM are effective methods of evaluating the dysmotility patterns in patients with chronic constipation. DARE and ARM could improve the diagnostic rate of OOC, and GITT assists in diagnosis of STC. Proper categorization of the dysmotility pattern is important for the clinical management of chronic constipation.
Study of visceral hypersensitivity in irritable bowel syndrome
Authors: DONG Wen Zhu , ZOU Duo Wu , LI Zhao Shen , ZOU Xiao Ping , ZHU Ai Yong , XU Guo Ming , YIN Ning , GONG Yan Fang , SUN Zhen Xing , MAN Xiao Hua 
Published: July 2004

OBJECTIVE:  Visceral hypersensitivity is highly prevalent in most functional bowel disorders, such as irritable bowel syndrome (IBS), and activation of intestinal mast cells (MC) may play a role because they have been found in close proximity to gastrointestinal mucosal sensory nerve terminals containing neuropeptides and a bi‐directional pathway connecting the central nervous system, gut, and MC has been demonstrated. The current study appraised the status of rectal visceral perception, as well as the changes in the MC and substance P (SP) in the intestinal mucosa of patients with IBS.METHODS:  The study group comprised 42 patients with IBS and 19 healthy subjects who underwent anorectal manometry and rectal perception thresholds to balloon distension. The MC and the SP‐ergic terminals in the mucosa were stained for respective histochemical and immunohistochemical investigations. The results were presented both qualitatively and quantitatively by color image analyzer, based on analysis of the intensity and area of stained fibrils. The structural relationship between the MC and nerve terminals was studied by electron microscopy, using an in situ embedding technique.RESULTS:  The anorectal resting pressure, squeezing pressure and relaxation pressure were normal in both groups. The sensation threshold, defecation threshold and pain threshold in diarrhea‐predominant IBS and the pain thresholds in constipation‐predominant IBS were much lower than in the controls. Rectal compliance decreased in IBS. The number of MC in the terminal ileum, the ileocecal junction and the ascending colon was significantly elevated in IBS (P < 0.01), and the MC showed great variation. A significantly increased concentration of SP was found in the colon of the IBS patients compared with the controls. There was a positive correlation between the profiles of mucosal MC and the SP‐ergic terminals, and MC were closely adjacent to SP‐ergic terminals in the lamina propria.CONCLUSION:  As altered rectal perception is present in almost all patients with IBS, it might be a reliable biological characteristic of the disease. Alterations in the MC and SP of the intestinal mucosa may be important factors in visceral hypersensitivity.
Input‐ and subunit‐specific AMPA receptor trafficking underlying long‐term potentiation at hippocampal CA3 synapses
Authors: Kakegawa Wataru , Tsuzuki Keisuke , Yoshida Yukari , Kameyama Kimihiko , Ozawa Seiji 
Published: July 2004

AbstractHippocampal CA3 pyramidal neurons receive synaptic inputs from both mossy fibres (MFs) and associational fibres (AFs). Long‐term potentiation (LTP) at these synapses differs in its induction sites and N‐methyl‐D‐aspartate receptor (NMDAR) dependence. Most evidence favours the presynaptic and postsynaptic mechanisms for induction of MF LTP and AF LTP, respectively. This implies that molecular and functional properties differ between MF and AF synapses at both presynaptic and postsynaptic sites. In this study, we focused on the difference in the postsynaptic trafficking of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptors (AMPARs) between these synapses. To trace the subunit‐specific trafficking of AMPARs at each synapse, GluR1 and GluR2 subunits were introduced into CA3 pyramidal neurons in hippocampal organotypic cultures using the Sindbis viral expression system. The electrophysiologically‐tagged GluR2 AMPARs, produced by the viral‐mediated transfer of the unedited form of GluR2 (GluR2Q), were inserted into both MF and AF postsynaptic sites in a neuronal activity‐independent manner. Endogenous Ca2+‐impermeable AMPARs at these synapses were replaced with exogenous Ca2+‐permeable receptors, and Ca2+ influx via the newly expressed postsynaptic AMPARs induced NMDAR‐independent LTP at AF synapses. In contrast, no GluR1 AMPAR produced by the gene transfer was constitutively incorporated into AF postsynaptic sites, and only a small amount into MF postsynaptic sites. The synaptic trafficking of GluR1 AMPARs was triggered by the activity of Ca2+/calmodulin‐dependent kinase II or high‐frequency stimulation to induce LTP at AF synapses, but not at MF synapses. These results indicate that MF and AF postsynaptic sites possess distinct properties for AMPAR trafficking in CA3 pyramidal neurons.
The distributed neuronal systems supporting choice‐making in real‐life situations: differences between men and women when choosing groceries detected using magnetoencephalography
Authors: Braeutigam Sven , Rose Steven P. R. , Swithenby Stephen J. , Ambler Tim 
Published: July 2004

AbstractIn this work, magnetoencephalography was used to study the temporal dynamics of neural responses in 16 subjects (eight women, eight men) choosing among different day‐to‐day consumer items. At short latencies (< 150 ms), the evoked responses showed striate and extrastriate cortical activation common to the processing of general objects. At about 300 ms, women activated preferentially left posterior cortices, whereas men activated preferentially right temporal cortices. This may reflect sex/gender differences in cognitive strategies, emphasizing category‐specific knowledge in women and spatial memories in men. At latencies greater than 500 ms, right parietal cortices were preferentially activated when previously bought or used items were chosen. In contrast, left inferior and right orbital cortices were preferentially activated when selecting less‐known items. This may be interpreted as representing the neural correlates of decisions where the outcome is consistent with previous experience, and of choices which are ‘difficult’ in some sense. Analysis of coherent γ‐oscillations (20–45 Hz) revealed neural activity over left anterior and right dorsolateral cortices at long latency (> 1500 ms) when brand knowledge is low. This is consistent with the late binding of (brand) memories and evaluation of multiple sources of information when a choice is not obvious. γ‐Activity showed that women may activate larger neural networks when preference is high, suggesting that men and women exhibit different patterns of neural activity even though their overt performances are similar.
Both d‐ and l‐glutamate induce transporter‐mediated presynaptic autoinhibition of transmitter release
Authors: Dudel Josef 
Published: July 2004

AbstractIn crayfish motor nerve terminals l‐glutamate (Glu) is the excitatory transmitter and low l‐Glu concentrations exert autoinhibition by inhibiting release of Glu quanta from the terminals. This autoinhibition has been shown to be mediated by binding and transport of l‐Glu by Glu transporters in the presynaptic membrane. Activated transporters open an associated Cl– channel and inhibit release [J. Dudel & M. Schramm (2003) Eur. J. Neurosci., 18, 902–910]. The excitatory, glutamatergic synaptic transmission is specific for the l‐Glu isomer. However, transporters are non‐selective for the stereoisomers. It is shown here that low concentrations (5 µm) of d‐ as well as l‐Glu inhibit quantal release on average to 55 and 68%, respectively. The power of inhibition varies widely at different terminals but the local sensitivity to d‐Glu is seen to be the same as that for l‐Glu. l‐Glutamate has been reported to reduce the mean amplitude of nerve terminal action currents (excitatory nerve terminal currents) by about 10%, presumably due to the opening of Cl– channels. Evidence is given that d‐Glu also inhibits this by an average of 10% (P < 0.001), as expected if both l‐ and d‐Glu activate a transporter‐associated Cl– conductance. The results give further support for this novel mechanism of regulation of synaptic strength.
Impaired behavioural flexibility and memory in mice lacking GDNF family receptor α2
Authors: Võikar Vootele , Rossi Jari , Rauvala Heikki , Airaksinen Matti S. 
Published: July 2004

AbstractThe glial cell line‐derived neurotrophic factor (GDNF) family receptor GFRα2 is the binding receptor for neurturin (NRTN). The main biological responses of GFRα2 are mediated via the Ret receptor tyrosine kinase, although it may also signal independently of Ret via the neural cell adhesion molecule NCAM. GFRα2 is expressed in many neurons of both the central and peripheral nervous system. Mice lacking GFRα2 receptors do not exhibit any gross defects in the central nervous system structure. However, they display profound deficits in the parasympathetic and enteric nervous system, accompanied by significant reduction in body weight after weaning. Here we present the results of behavioural analysis of the GFRα2‐knockout mice. The knockout mice did not differ from wild‐type mice in basic tests of motor and exploratory activity. However, differences were established in several memory tasks. The knockout mice were not impaired in the acquisition of spatial escape strategy. However, the deficit in flexibility in establishing a new strategy was revealed during reversal learning with the platform in the opposite quadrant of the pool. Furthermore, the knockout mice displayed significant impairment in contextual fear conditioning and conditioned taste aversion tests of memory. The results suggest that GFRα2 signalling plays a role in the development or maintenance of cognitive abilities that help in solving complex learning tasks.
Microstimulation of V1 delays the execution of visually guided saccades
Authors: Tehovnik Edward J. , Slocum Warren M. , Schiller Peter H. 
Published: July 2004

AbstractElectrical stimulation delivered to V1 concurrently with the presentation of a visual target interferes with both the selection and the detection of targets positioned in the receptive field of the stimulated neurons. In the present study, we examined the temporal course of this effect by delivering electrical stimulation to V1 of rhesus monkeys at various times before the appearance of a visual target. Each trial was initiated by the appearance of a fixation spot that, once acquired, was followed by the presentation of a visual target in the receptive field of the stimulated neurons. A monkey was reward after making a saccadic eye movement to the target. A delay in saccade generation was obtained when stimulation was delivered while an animal maintained fixation on the fixation spot. No delay occurred when the visual target was placed outside the receptive field of the stimulated neurons. The best parameters for inducing the saccadic delay were: (i) anode‐first pulses (as opposed to cathode‐first pulses) and (ii) train durations greater than 40 ms and frequencies greater than 100 Hz. The lowest current threshold for producing a saccadic delay occurred at 1.5 mm below the top of superficial V1. The chronaxies of the directly stimulated elements mediating the delay ranged from 0.13 to 0.24 ms. These values overlap with those that have been described for phosphene induction in human V1. We discuss how the elements mediating the saccadic delay might interrupt a visual signal as it passes along the geniculostriate pathway.
Temporary cyst formation in phytoplankton: a response to allelopathic competitors?
Authors: Fistarol Giovana O. , Legrand Catherine , Rengefors Karin , Granéli Edna 
Published: July 2004

SummaryCompetition among phytoplankton for limiting resources may involve direct or indirect interactions. A direct interaction of competitors is the release of chemicals that inhibit other species, a process known as allelopathy. Here, we investigated the allelopathic effect of three toxic microalgae species (Alexandrium tamarense, Karenia mikimotoi and Chrysochromulina polylepis) on a natural population of the dinoflagellate Scrippsiella trochoidea. Our major findings were that in addition to causing death of S. trochoidea cells, the allelopathic species also induced the formation of temporary cysts in S. trochoidea. Because cysts were not lysed, encystment may act as a defence mechanism for S. trochoidea to resist allelochemicals, especially when the allelopathic effect is moderate. By forming temporary cysts, S. trochoidea may be able to overcome the effect of allelochemicals, and thereby have an adaptive advantage over other organisms unable to do so.