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Long Process (long + process)
Selected AbstractsElectrophysiological and morphological characterization of dentate astrocytes in the hippocampusDEVELOPMENTAL NEUROBIOLOGY, Issue 2 2005Masako Isokawa Abstract We studied electrophysiological and morphological properties of astrocytes in the dentate gyrus of the rat hippocampus in slices. Intracellular application of Lucifer yellow revealed two types of morphology: one with a long process extruding from the cell body, and the other with numerous short processes surrounding the cell body. Their electrophysiological properties were either passive, that is, no detectable voltage-dependent conductance, or complex, with Na+/K+ currents similar to those reported in the Ammon's horn astrocytes. We did not find any morphological correlate to the types of electrophysiological profile or dye coupling. Chelation of cytoplasmic calcium ([Ca2+]i) by BAPTA increased the incidence of detecting a low Na+ conductance and transient outward K+ currents. However, an inwardly rectifying K+ current (Kir), a hallmark of differentiated CA1/3 astrocytes, was not a representative K+ -current in the complex dentate astrocytes, suggesting that these astrocytes could retain an immature form of K-currents. Dentate astrocytes may possess a distinct current profile that is different from those in CA1/3 Ammon's horn. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005 [source] Ethical issues related to epilepsy care in the developing worldEPILEPSIA, Issue 5 2009Chong-Tin Tan Summary There are three major issues of ethical concern related to epilepsy care in the developing world. First, is it ethical for a developing country to channel its limited resources from direct epilepsy care to research? The main considerations in addressing this question are the particular research questions to be addressed and whether such research will bring direct benefits to the local community. Second, in a country with limited resources, when does ignoring the high treatment gap become an ethical issue? This question is of particular concern when the community has enough resources to afford treatment for its poor, yet is not providing such care because of gross wastage and misallocation of the national resources. Third, do countries with plentiful resources have an ethical responsibility to help relieve the high epilepsy treatment gap of poor countries? Indeed, we believe that reasonable health care is a basic human right, and that human rights transcend national boundaries. Although health care is usually the responsibility of the nation-state, many modern states in the developing world are arbitrary creations of colonization. There is often a long process from the establishment of a political-legal state to a mature functional nation. During the long process of nation building, help from neighboring countries is often required. [source] Mission Encounters in the Colonial World: British Columbia and South-West AustraliaJOURNAL OF RELIGIOUS HISTORY, Issue 2 2000Peggy Brock This paper considers various aspects of the interactions of missions and indigenous peoples in regions of Canada and Australia. An analysis of first encounters indicates that the introduction of Christianity was dependent on both evangelist and client population agreeing to a modus operandi for the mission. The structure and operation of the mission were determined by the pre-existing indigenous society and the financial and personnel resources of the mission organizations. Attitudes towards, and acceptance of, Christianity were not static, they depended on changing material and political circumstances both within and outside indigenous communities. This comparative analysis indicates that religious change was not only negotiated between missionary and "convert," but among indigenous peoples themselves. The decision to profess Christianity was not a one-off decision made by individuals or communities. Rather it was a long process of change which was contingent on the perceived advantages and disadvantages of the mission world and countervailingpressures from within indigenous and colonial societies. [source] Corporatism and Democratic Transition: State and Labor During the Salinas and Zedillo AdministrationsLATIN AMERICAN POLITICS AND SOCIETY, Issue 4 2002James G. Samstad ABSTRACT A long process of free-market reforms and gradual democratization seems to be dismantling Mexico's corporatist system of labor representation. A thorough analysis of the country's corporatist institutions yields theoretical reasons to believe that Mexico's practice of labor relations is indeed changing. An empirical examination of the nation's labor congress and ruling party during the two previous presidential administrations (1988,2000) demonstrates that corporatism is being transformed at a practical level, although the process of reform has been complex and uneven at best. The continuing strength of an officialist labor sector will complicate the task of establishing a new system of labor representation, a problem that may have important implications for future democratic consolidation. [source] Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells.MICROSCOPY RESEARCH AND TECHNIQUE, Issue 4 2010Part 2: Changes in spermatid organelles associated with development of spermatozoa Abstract Spermiogenesis is a long process whereby haploid spermatids derived from the meiotic divisions of spermatocytes undergo metamorphosis into spermatozoa. It is subdivided into distinct steps with 19 being identified in rats, 16 in mouse and 8 in humans. Spermiogenesis extends over 22.7 days in rats and 21.6 days in humans. In this part, we review several key events that take place during the development of spermatids from a structural and functional point of view. During early spermiogenesis, the Golgi apparatus forms the acrosome, a lysosome-like membrane bound organelle involved in fertilization. The endoplasmic reticulum undergoes several topographical and structural modifications including the formation of the radial body and annulate lamellae. The chromatoid body is fully developed and undergoes structural and functional modifications at this time. It is suspected to be involved in RNA storing and processing. The shape of the spermatid head undergoes extensive structural changes that are species-specific, and the nuclear chromatin becomes compacted to accommodate the stream-lined appearance of the sperm head. Microtubules become organized to form a curtain or manchette that associates with spermatids at specific steps of their development. It is involved in maintenance of the sperm head shape and trafficking of proteins in the spermatid cytoplasm. During spermiogenesis, many genes/proteins have been implicated in the diverse dynamic events occurring at this time of development of germ cells and the absence of some of these have been shown to result in subfertility or infertility. Microsc. Res. Tech., 2010. © 2009 Wiley-Liss, Inc. [source] Saliva of the graminivorous Theropithecus gelada lacks proline-rich proteins and tannin-binding capacityAMERICAN JOURNAL OF PRIMATOLOGY, Issue 8 2009Marcus Mau Abstract Gelada baboons are the sole survivors of the genus Theropithecus and the only known graminivorous primates. They developed special adaptations to their diet such as high-crowned teeth for processing hard and abrasive feed. The fine-tuning of salivary protein composition might be another key mechanism that is used by species for adapting to the environment and competing with rivals for exploiting new ecological niches. In order to test whether gelada (graminivorous) and hamadryas baboons (omnivorous) differ in their salivary protein composition, we compared whole saliva samples of captive Theropithecus gelada and Papio hamadryas using gel electrophoresis and tannin-binding assay. We hypothesized that the amount of proline-rich salivary proteins with tannin-binding capacity is higher in baboons consuming a feed with high dicot/monocot rations. Dicots produce tannins as a chemical defense system, discouraging animals from eating them. In contrast to dicots, monocots do not synthesize tannins. The presence of tannin-binding proteins in saliva should effectively inactivate the dicot tannin-based defense mechanism and increase the dietary breadth and/or the capability to switch between monocots and dicot leaves. The lack of such tannin-binding proteins in saliva would indicate a narrow dietary spectrum more restricted to monocots. We found T. gelada to completely lack proline-rich proteins (PRPs) and tannin-binding capacity similar to a great variety of other grazing mammals. In contrast, P. hamadryas does possess PRPs with tannin-binding activity. The findings support a growing body of evidence suggesting a high-level specialization of T. gelada to grass diets. However, it remains unclear, whether loss of salivary tannin-binding capacity drove the gelada into its narrow feeding niche, or whether this loss is the result of a long process of increased specialization. Thus, from an ecological point of view, T. gelada appears to be more vulnerable to environmental changes than other baboon species owing to its narrow dietary traits. Am. J. Primatol. 71:663,669, 2009. © 2009 Wiley-Liss, Inc. [source] THE INDIVIDUAL AND TRANSFORMATION OF BRIDEWEALTH IN RURAL NORTH CHINATHE JOURNAL OF THE ROYAL ANTHROPOLOGICAL INSTITUTE, Issue 4 2005Yunxiang Yan Drawing on data collected from longitudinal fieldwork, this article explores how the practice of bridewealth in a north China village has been transformed into a new form of property division within the groom's family and how the bride has replaced her parents as the recipient of bridewealth. At the individual level, this transformation has evolved through a long process during which individual brides and grooms negotiated with their parents over control of bridewealth. A misunderstanding about Western individualism provides village youths with a new ideological tool to justify their relentless extraction of money from their parents. At the level of family life, the changing norm of bridewealth has shaped and in turn has helped to re-shape mate choice, family division, and support for the elderly. These family changes occurred within the context of other social changes at the macro level and are closely linked to the role of the powerful state. While emphasizing the active role of the individual in transforming the practice of bridewealth, an important phenomenon that by and large has been overlooked in most studies of marriage transactions, the article also examines the specific strategies by which individuals exercise their agency, choosing to take advantage of the custom of bridewealth instead of abandoning it when it affords them greater autonomy in mate choice and marriage negotiations. [source] Necrosis of the long process of the incus following stapes surgery: New anatomical observations,,THE LARYNGOSCOPE, Issue 4 2009Imre Gerlinger MD Abstract Objectives/Hypothesis: The most frequent complication (generally recognized during revision procedures) following seemingly successful stapedotomies and stapedectomies is necrosis of the long process of the incus. This is currently ascribed to a malcrimped stapes prosthesis or to a compromised blood supply of the incus. The two-point fixation can cause a mucosal injury with a resulting toxic reaction, and also osteoclastic activity. An important aspect in the engineering of ideal stapes prostheses is that they should be fixed circularly to the long process of the incus with appropriate strength. The objective of this study was to compare current knowledge relating to the blood supply of the ossicular chain with the present authors' observations on cadaver incudes. Most of the papers dealing with this issue appeared in the mid-20th century. Methods: The published data were compared with the authors' findings gained from photodocumentation on 100 cadaver incudes. The photos were taken with a Canon EOS 20 digital camera (Canon, Inc., Lake Success, NY) with a 5:1 macro-objective. The long processes of the incudes were examined from four directions under a Leica surface-analyzing microscope (Leica Microsystems GmbH, Wetzlar, Germany). Results: Analysis of the positions of the entrances of the feeding arteries (nutritive foramina) on the incudes revealed 1-4 nutritive foramina on the long processes of 48% (24) of the left-sided incudes and 56% (28) of the right-sided incudes. The positions of these foramina differed, however, from those previously described in the literature. They were mostly located not on the medial side of the incus body or on the short process or on the cranial third of the long processes, but antero-medially, mostly on the middle or cranial third. In 48% of all the incudes examined, an obvious foramen was not observed either in the body or in the long process of the incus. No relationship was discerned between the chronological age of the incus specimens and the numbers and/or locations of the nutritive foramina. In each case, the opening of the foramen was the beginning of a tunnel running obliquely and medially upward through the corticalis of the long process of the incus. The foramina are thought to be capable of ensuring a richer blood supply between the surface and the inside of the long process, allowing the arteries to run in and out. Conclusions: These observations indicate that conclusions drawn from classical anatomical works appear to need reconsideration. The present authors consider that the reason for the necrosis of the long process of the incus is not a compromised blood supply, except in some exceptional anatomical situations. They discuss the possible reasons why malcrimping may lead to necrosis of the long process of the incus. To prevent such malcrimping, attention is paid to the new generation of prostheses. Laryngoscope, 2009 [source] Quantitative Analysis of Tympanic Membrane Disease Using Video-Otoscopy ,THE LARYNGOSCOPE, Issue 10 2000Vikram J. Jaisinghani MD Abstract Objective To perform quantitative analysis of pathological changes in the tympanic membrane using video-otoscopic images. Study Design Prospective case-control study. Methods Forty-two ears of children with chronic otitis media with effusion (OME) and 15 ears of normal children were included in this study. Tympanic membrane images were captured and digitized using a Welch-Allyn (Skaneatales Falls, NY) VDX-300 Illumination and Imaging system with S-VHS input to a MIRO DC 30 (Pinnacle Systems, Mountain View, CA) visual board in a Power PC,based computer. These images were visualized and recorded during static and pneumatic pressure changes. Quantitative analysis of tympanic membrane disease was performed using Image Pro Plus Imaging software (Media Cybernetics, Del Mar, CA). The measurements included area of the tympanic membrane and its quadrants, area of tympanic membrane involved by disease, angle formed at the umbo, and length of the malleus versus vertical length of the tympanic membrane. Results Tympanosclerosis was present in 57% of ears and occurred most frequently in the anteroinferior quadrant, but the ma-imum area of involvement was in the posteroinferior quadrant. The ratio of the angles formed at the umbo was significantly greater (P = .01) for the OME group compared with the control group. The ratio of the length of the umbo and the vertical length of the tympanic membrane was almost identical for the OME and the control groups (P = .4). Conclusions Video-otoscopic images can be used for quantitative analysis of tympanic membrane disease. The ratio of the posterior angle to the anterior angle formed at the umbo seems to be a more reliable indicator of post otitis media than is a reduced length of the long process of malleus. [source] Audiometric evaluation of an attempt to optimize the fixation of the transducer of a middle-ear implant to the ossicular chain with bone cementCLINICAL OTOLARYNGOLOGY, Issue 1 2004A. Snik Audiometric evaluation of an attempt to optimize the fixation of the transducer of a middle-ear implant to the ossicular chain with bone cement Typically, an implantable hearing device consists of a transducer that is coupled to the ossicular chain and electronics. The coupling is of major importance. The Vibrant Soundbridge (VSB) is such an implantable device; normally, the VSB transducer is fixed to the ossicular chain by means of a special clip that is crimped around the long process of the incus. In addition to crimping, bone cement was used to optimize the fixation in six patients. Long-term results were compared to those of five controls with crimp fixation alone. To assess the effect of bone cement (SerenoCem®, Corinthian Medical Ltd, Nottingham, UK) on hearing thresholds, long-term post-surgery thresholds were compared to pre-surgery thresholds. Bone cement did not have any negative effect. Next, to test the hypothesis that aided thresholds might be better with the use of bone cement, aided thresholds were studied. After correction for the severity of hearing loss, only a small difference was found between the two groups at one frequency, viz. 2 kHz. It was concluded that there was no negative effect of using bone cement; however, there is also no reason to use bone cement in VSB users on a regular basis. [source] Glutamate Receptor Subunit ,2 Is Highly Expressed in a Novel Population of Glial-Like Cells in Rat Pineal Glands in CultureJOURNAL OF NEUROCHEMISTRY, Issue 3 2000Shouki Yatsushiro Abstract: The mammalian pineal gland uses L-glutamate as an intercellular chemical transmitter to regulate negatively melatonin synthesis. To receive glutamate signals, pinealocytes express at least three kinds of glutamate receptors: metabotropic receptor types 3 and 5 and an ionotropic receptor, GluR1. In this study, we examined whether or not the fourth class of ionotropic receptor, ,, which is known for its nondefinitive molecular function and its unique expression pattern in brain, is expressed in pineal gland. RT-PCR analyses with specific probes indicated the expression of mRNA of ,2 but not that of ,1 in pineal gland and cultured pineal cells. Western blotting analysis with polyclonal antibodies specific to the carboxyl-terminal region of the ,2 receptor recognized a single 110-kDa polypeptide of cerebellar membranes and specifically immunostained Purkinje cells. The ,2 antibodies recognized a 110-kDa polypeptide of pineal membranes and specifically immunostained huge glial-like cells with the occasional presence of several long, branching processes in a pineal cell culture. ,2 is not uniformly distributed throughout the cells and is relatively abundant at the periphery of the cell bodies and long processes, where the terminals of synaptophysin-positive processes of pinealocytes, a site for glutamate secretion, are frequently present. The ,2-positive cells constitute a very minor population among total pineal cells (,0.03%). Double immunolabeling with ,2 antibodies and antibodies against marker proteins for pineal interstitial cells clearly distinguishes ,2-positive pineal cells and other known interstitial cells, including glial fibrillary acidic protein- or vimentin-positive glial-like cells. These results indicated that the ,2 glutamate receptor is expressed in a novel subpopulation of pineal glial-like cells in culture and suggest the presence of a glutamate-mediated intercellular signal transduction mechanism between pinealocytes and ,2-expressing cells. The pineal cells may provide a good experimental system for studies on the function of glutamate receptor ,2. [source] Necrosis of the long process of the incus following stapes surgery: New anatomical observations,,THE LARYNGOSCOPE, Issue 4 2009Imre Gerlinger MD Abstract Objectives/Hypothesis: The most frequent complication (generally recognized during revision procedures) following seemingly successful stapedotomies and stapedectomies is necrosis of the long process of the incus. This is currently ascribed to a malcrimped stapes prosthesis or to a compromised blood supply of the incus. The two-point fixation can cause a mucosal injury with a resulting toxic reaction, and also osteoclastic activity. An important aspect in the engineering of ideal stapes prostheses is that they should be fixed circularly to the long process of the incus with appropriate strength. The objective of this study was to compare current knowledge relating to the blood supply of the ossicular chain with the present authors' observations on cadaver incudes. Most of the papers dealing with this issue appeared in the mid-20th century. Methods: The published data were compared with the authors' findings gained from photodocumentation on 100 cadaver incudes. The photos were taken with a Canon EOS 20 digital camera (Canon, Inc., Lake Success, NY) with a 5:1 macro-objective. The long processes of the incudes were examined from four directions under a Leica surface-analyzing microscope (Leica Microsystems GmbH, Wetzlar, Germany). Results: Analysis of the positions of the entrances of the feeding arteries (nutritive foramina) on the incudes revealed 1-4 nutritive foramina on the long processes of 48% (24) of the left-sided incudes and 56% (28) of the right-sided incudes. The positions of these foramina differed, however, from those previously described in the literature. They were mostly located not on the medial side of the incus body or on the short process or on the cranial third of the long processes, but antero-medially, mostly on the middle or cranial third. In 48% of all the incudes examined, an obvious foramen was not observed either in the body or in the long process of the incus. No relationship was discerned between the chronological age of the incus specimens and the numbers and/or locations of the nutritive foramina. In each case, the opening of the foramen was the beginning of a tunnel running obliquely and medially upward through the corticalis of the long process of the incus. The foramina are thought to be capable of ensuring a richer blood supply between the surface and the inside of the long process, allowing the arteries to run in and out. Conclusions: These observations indicate that conclusions drawn from classical anatomical works appear to need reconsideration. The present authors consider that the reason for the necrosis of the long process of the incus is not a compromised blood supply, except in some exceptional anatomical situations. They discuss the possible reasons why malcrimping may lead to necrosis of the long process of the incus. To prevent such malcrimping, attention is paid to the new generation of prostheses. Laryngoscope, 2009 [source] | ||||||||||||||||