bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioartificial Pancreas: Alternative Supply of Insulin‐secreting Cells
Authors: ZHOU DAOBIAO , KINTSOURASHVILI EKATERINA , MAMUJEE SALIM , VACEK IVAN , SUN ANTHONY M. 
Published: February 2006

ABSTRACT: In this study, insulin secretion function of INS‐1 cells immunoisolated in microcapsules was evaluated. Following encapsulation, the immunoisolated INS‐1 cells continued to propagate and flourish within the microcapsules during the entire two‐month in vitro incubation period. The insulin secretion from encapsulated INS‐1 cells following seven days of in vitro culture increased from 1.6 ± 0.2 ng/2H/106 cells in a glucose‐free medium to 11.5 ± 2.1 ng/2h/106 cells at 16.7 mM glucose. In vivo, transplants of 1.2 × 107 cells into each of six diabetic C57BL/6 mice resulted in the restoration of normoglycemia in all graft recipients for up to 60 days post transplantation. most capsules recovered from two animals 30 days post tarnsplantation were free of cell overgrowth and physically intact. Immunostaining for insulin of the cells within the recovered capsules clearly indicated the presence of insulin.The presented data demonstrate the potential use of an immunoisolated β‐cell line for the treatment of diabetes.
Mutation Testing in Charcot‐Marie‐Tooth Neuropathy
Authors: NICHOLSON GARTH A. 
Published: February 2006

ABSTRACT: In order to determine the optimal approach for mutation testing in the form of Charcot‐Marie‐Tooth (CMT) neuropathy, consecutive patients with a CMT phenotype, available family history information on at least first‐degree relatives, and median motor conduction velocities of less than 50 m/sec were tested for the CMT1A duplication and for connexin32, peripheral myelin protein 22 (PMP22) and myelin protein zero (P0) point mutations. A cutoff value for median motor conduction velocity of less than 50 m/sec was adopted to include all CMTX families.All of the connexin32 mutations, except for one sporadic case, were found by first selecting families with no male‐to‐male inheritance of CMT and neurophysiological indicators of CMTX. All PMP22 and P0 mutations were found by selecting Dejerine‐Sottas cases or dominantly inherited CMT1 with a very severe phenotype. It is concluded that “blind” testing of CMT1 families for connexin32, P0, and PMP22 mutations is of limited value.
Calpain Inhibitors as Therapeutic Agents in Nerve and Muscle Degeneration
Authors: STRACHER ALFRED 
Published: February 2006

ABSTRACT: It seems plausible to hypothesize that in all forms of neurodegeneration or other forms of tissue degeneration, a common pathway exists that, when deciphered, could lead to our understanding of a variety of diseases that result in tissue necrosis, as well as offer potential for therapeutic intervention. In recent years progress toward elucidating this common pathway has been accelerated through the studies of a number of laboratories, including our own, on the role of the protease calpain in this process. Thus, in a variety of disorders, such as stroke, spinal cord injury, traumatic nerve injury, Parkinson's disease, amyotrophic lateral sclerosis (ALS), Alzheimer's disease, muscular dystrophy, cataract formation, unregulated calpain proteolysis, initiated via dysregulation of calcium ion homeostasis, participates in the pathogenesis and is a potentially unifying mechanistic event.In order to demonstrate the feasibility of the approach we have taken in using the calpain inhibitor leupeptin as a therapeutic agent, I will describe two areas of research in which we have been engaged over the past 20 years. One is our long‐standing interest in muscular dystrophy. The other is of more recent vintage, and involves the use of calpain inhibitors to protect sensory hair cells and spiral ganglion neurons from damage associated with acoustic trauma, this latter in collaboration with Dr. R. Salvi at SUNY‐Buffalo and Dr. A. Shulman at SUNY‐Downstate.
Acute and Chronic Effects of Aminoglycosides on Cochlear Hair Cells
Authors: ARAN JEAN‐MARIE , ERRE JEAN‐PAUL , DA COSTA DEISE LIMA , DEBBARH IKRAM , DULON DIDIER 
Published: February 2006

ABSTRACT: The first detectable effect on the auditory system after a single high‐dose injection of an aminoglycosidic antibiotic (AA) like gentamicin (GM) is the reversible blockade of medial efferent function, probably via blockade of calcium channels at the base of the outer hair cells (OHC). The kinetics of this effect are compatible with that of the molecule in perilymph. In the course of chronic treatment with lower doses, however, ototoxicity develops only after several days of treatment. Still GM can be observed inside the OHCs as soon as 24 hours after the first injection, and will be still present in some OHCs as long as 11 months after a chronic, nonototoxic 6‐day treatment. In vitro, the short‐term viability of isolated OHCs is not affected by exposure to AAs, but their transduction channels and their response to acetylcholine are reversibly blocked. However, developing organs of Corti in culture are highly and rapidly affected by exposure to AAs. Yet during direct intracochlear perilymphatic perfusion of GM, 2‐mM solutions are not ototoxic, and with perfusion with a 20‐mM solution ototoxicity develops only after several days of perfusion.From these various observations one can describe some aspects of the mechanisms of ototoxicity of AAs, from their access to perilymph and endolymph, to penetration in the hair cells, likely via endocytosis at their apical pole, and intracellular cytotoxic events.
Normal and Altered Cytoarchitecture of the Inner Ear
Authors: SERRA A. , GRASSO D. L. , COCUZZA S. , TROMBETTA L. , LA MANTIA I. 
Published: February 2006

ABSTRACT: Scanning electron microscope gave new insights into real morphology of the inner ear and has enhanced basic research. In fact, during the last twenty years, the cellular system that composes the organ of Corti and the vestibular apparatus has been clearly described by many authors. We now have a better understanding of each cell type and that they have a physiological functioning as ear and vestibular system.In addition, new insights into the damage caused by many drugs, such as aminoglucosides, can be investigated by studying the morphological changes and the reparative process following the injury. Animals such as guinea pigs can be used as ideal models to investigate the alterations in the sensory epithelium of the cochlear and veastibular receptors following ototoxic poisoning.
Role of Neurotrophins and Lectins in Prevention of Ototoxicity
Authors: GAO WEI‐QIANG 
Published: February 2006

ABSTRACT: Degeneration of hair cells (HC) and/or spiral ganglion neurons (SGN) is a major cause of hearing loss. Postnatal rat cochlear explant cultures are used to study the toxic actions of different classes of ototoxins and to identify molecules that can protect SGN and HC from ototoxic damage. Various ototoxins induce differential damage to HC and/or SGN. While gentamicin preferentially causes HC death, sodium salicylate selectively induces degeneration of SGN. In contrast, cisplatin results in destruction of both SGN and HC. Specific neurotrophins, including NT‐4/5, BDNF, and NT‐3, greatly protect SGN from all three types of ototoxins. In contrast, NGF and other growth factors have no effect.Of the 51 compounds examined, only concanavalin A (Con A), a lectin molecule, significantly protects HC from gentamicin. A dose‐dependent study of Con A shows that maximal protection occurred at 100 nM. Further experiments indicates that preincubation of Con A with gentamicin does not form a complex, and coaddition of Con A and gentamicin to bacterial cultures, such as E. Coli cultures, does not interfere with the antibiotic activity of gentamicin. When the other 21 lectins are examined, Erythrina cristagalli lectin and Detura stramonium lectin also show activity similar to Con A. These findings may help elucidate the mechanisms of ototoxins and suggest that specific neurotrophins and lectins may be of therapeutic value in the prevention of ototoxin‐induced hearing loss.
Treatment of Acoustic Trauma
Authors: D'ALDIN CHRISTINE , CHERNY LILY , DEVRIÈRE FRANCIS , DANCER A. 
Published: February 2006

ABSTRACT:The aim of this study is to determine the actual efficiency of the present medical treatments of acoustic trauma. Untreated and treated groups of guinea pigs are exposed to a traumatic noise exposure, inducing up to 60‐dB threshold shift. The recovery is followed for up to 14 days. The first results indicate that in some animals the recovery of the threshold shifts are complete despite the fact that significant areas of hair cells are damaged.The most widely used medical treatments of acoustic trauma (oxygenotherapy, carbogen, hyperbaric oxygen, vasoactive agents, and corticotherapy) have been tested. Preliminary results indicate that pure oxygen and carbogen seem ineffective, hyperbaric oxygen used alone is dangerous, and corticoids and combined corticoid/hyperbaric oxygen seem to improve functional and morphological recovery. This study will be taken as a reference to look for new treatments that will be applied directly to the cochlea by means of an implanted osmotic micropump.
Protective Effect of the Cochlear Efferent System During Noise Exposure
Authors: ATTANASIO GIUSEPPE , BARBARA MAURIZIO , BUONGIORNO GIUSEPPE , CORDIER ALDO , MAFERA BARBARA , PICCOLI FEDERICO , NOSTRO GABRIELE , FILIPO ROBERTO 
Published: February 2006

ABSTRACT: The aim of the present study was to confirm the hypothesis that the cochlear efferent system is involved in the mechanisms underlying the “toughening” effect at high frequencies. The toughening effect is defined as a progressive threshold shift reduction when repeated exposures to the same noise are applied. Vestibular neurectomy was performed through a posterior cranial fossa approach in six healthy pigmented guinea pigs, and it assured the interruption of both crossed and uncrossed olivocochlear bundles to one ear only, before their entrance in the internal auditory meatus. The animals were then implanted with permanent electrodes for the electrocochleographic findings. Ten days after the operation the animals were exposed to octave‐band toughening noise, centered at 4 kHz, at 85‐dB SPL, for 10 consecutive days, 6 hours on/18 hours off. The hearing threshold was registered before and at the end of each exposure session. The behavior of the hearing threshold in the operated ears was then compared to that of the controlateral, nonoperated ears. Complete recovery from TS in the control ear began after four days of exposure, whereas in the operated ear hearing loss increased to day 7 (55 dB), with only a partial reduction (45 dB) beyond ten days of exposure.The results of the present study clearly demonstrated that sectioning of the OCB in guinea pigs causes persistent hearing loss during noise‐exposure conditioning, in comparison to the contralateral, nonoperated ear. Thus, one can assume that the lack of decrease of TS during intermittent noise exposure could be due to the loss of the protective effect of the efferent fibers, perhaps mediated by the lateral OC neurons that synapse beneath the IHCs.
Intratympanic Therapy for Ménière's Disease: High‐Concentration Gentamicin with Round‐Window Protection
Authors: QUARANTA A. , ALOISI A. , DE BENEDITTIS G. , SCARINGI A. 
Published: February 2006

ABSTRACT: Many therapeutic options exist for the management of patients with Ménière's disease. In the last few years, the use of intratympanic gentamicin has been investigated as an alternative treatment to vestibular nerve section or labyrinthectomy.In humans, the concentration of gentamicin used for intratympanic treatment of vertigo ranges from 10 mg/mL to 40 mg/mL, and the number of doses from 2 to 14, with a total administered amount between 6 and 2.400 mg. Here lower doses of gentamicin were used, usually had the lowest incidence of hearing loss, but more injections were needed to ablate vestibular function.The purpose of this study was to evaluate the acute and chronic ototoxic effects of intratympanic high‐concentration gentamicin after having obliterated the round‐window niche with connective tissue in 11 subjects' ears with Ménière's disease.Intratympanic gentamicin was administered according to a predetermined and fixed schedule consisting of two doses of 0.5 mL gentamicin solution, injected once a week with a drug concentration of 80 mg/mL. The total dose of gentamicin was ≤80 mg.The charts of the patients were surveyed in accordance with the 1995 AAO‐HNS guidelines. Three patients had recurrence of vertigo between 3 and 6 months after the second injection and went on to one additional dose of gentamicin.At 2 years follow‐up, 10 patients (91%) had complete and 1 (9%) substantial control of vertigo; 3 subjects (27%) had hearing decreased. Tinnitus disappeared or decreased in 3 patients (27%); eight subjects (73%) reported their aural pressure abolished or decreased.The present study demonstrates that in patients with Ménière's disease, 0.5 mL gentamicin solution, with a concentration of 80 mg/mL (total dose ≤80 mg), injected intratympanically once a week after having obliterated the round‐window niche, permits complete or substantial control of vertigo in two‐thirds of cases after two doses and in all subjects after three doses. This vertigo control rate is compared to that observed after vestibular nerve section. Hearing results are not different from those with natural control, with endolymphatic sac surgery, and with vestibular nerve section.
Cochlear Effects of Mesna Application into the Middle Ear
Authors: VINCENTI V. , MONDAIN M. , PASANISI E. , PIAZZA F. , PUEL J.‐L. , BACCIU S. , QUARANTA N. , UZIEL A. , ZINI C. 
Published: February 2006

ABSTRACT: Mesna (sodium 2‐mercapto‐ethane sulphonate) belongs to a class of thiol compounds that produce mucolysis by disrupting the disulphide bonds of the mucus polypeptide chains. The registered indications of mesna include the treatment of pathologies of the respiratory tract and, in oncology, the prevention of toxic lesions of the urinary tract by antineoplastic agents.In the E.N.T. Clinic of the University of Parma, it has been found that mesna can be used to facilitate the dissection of the various tissue layers in any surgical procedure. One of these indications is surgical treatment of cholesteatoma, which is mainly composed by keratin, a protein rich in disulphide bonds that are easily disrupted by mesna. The aim of this study was to evaluate the toxicity of mesna application into the middle ear on the cochlear anatomy and physiology. Three groups of guinea pigs were used as subjects. Mesna solution (10 or 20%) was applied in one ear, while the opposite ear received a placebo (saline solution). Toxicity of mesna was assessed by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), and auditory brain‐stem response (ABR). TEM and SEM did not show any toxic effect on cochlear morphology. There were no differences in ABR thresholds and wave III amplitude and latency between mesna‐treated and control ears.
The Cochleovestibular System/Ototoxicity/Clinical Issues
Authors: SHULMAN ABRAHAM 
Published: February 2006

ABSTRACT: It is recommended that the experiences of basic science with ototoxicity be applied to the development of specific clinical strategies for the treatment of the cochleovestibular complaints of hearing loss, tinnitus, vertigo, and ear blockage. The treatment goals are to maintain/improve function, namely, hearing and balance, as well as to control aberrant auditory and vestibular phenomena, for example, tinnitus and vertigo originating within the peripheral and/or central cochleovestibular system.It is hypothesized that a “common” neurochemical basis for “toxicity” exists, whatever the primary toxic etiology. It is also recommended that the neurochemical mechanisms of neuroprotection and apoptosis be considered for investigations of ototoxicity.Furthermore, it is suggested that ototoxicities are reflected in clinical manifestations of sensory cochleovestibular complaints of hearing loss, tinnitus, and vertigo, and affect complaints of stress, pain, and neuropsychiatric disorders.
Diagnostics and Modelling of a Thermal RF Plasma Process Used for the Flash Evaporation of Zirconia Powders
Authors: Buchner P. , Schubert H. , Uhlenbusch J. , Weiβ M. , Willée K. 
Published: February 2006

ABSTRACT: The evaporation process of zirconia powders injected in a thermal RF plasma is investigated. Both model calculations and experimental techniques such as Optical Emission Spectroscopy (OES) and Laser Doppler Anemometry (LDA) are used to study the evaporation behaviour. Gas temperatures and velocity distributions are determined numerically from conservation laws and Maxwell equations. The influence of plasma and particle parameters on the thermal interaction of injected particles is discussed. Asymmetric Abel inversion is applied to detect asymmetric emission profiles in the plasma source. Spectroscopic measurements reveal that evaporated zirconia is concentrated near the axis of the plasma. Numerical calculations show that line‐integrated emission profiles can be used to distinguish the cases of complete and incomplete evaporation.LDA measurements of the particle velocity distribution show good agreement with the results achieved with modelling.
Replication of Passive Whole‐Body Linear Displacements from Inertial Cues: Facts and Mechanisms
Authors: GRASO R. , GLASAUER S. , GEORGE‐FRANÇOIS P. , ISRAËL I. 
Published: February 2006

Abstract: Using path integration, normal subjects should be able to compute the distance of a traveled path even from the sole inertial sensory input. Blindfolded subjects were submitted to a passive linear forward displacement along 2 to 10 m. Their task was to replicate the traveled distance, still blindfolded, by driving the vehicle they were seated upon using a joystick that controlled linear speed.Subjects replicated both the length and the velocity profile of the passive travel, suggesting that a dynamic record of experienced motion is stored in memory. Even when the replication of passive motion dynamics was made impossible, the subjects could still replicate the displacement.The results are explained by a dynamic feedback model that performs a running comparison between the perceived instantaneous displacement of the ongoing motion and the displacement derived from a spatiotemporal record of perceived passive motion. A multimodal acceleration‐related sensory input is transformed into a displacement‐related perception through double time‐integration.
Rofecoxib and tramadol do not attenuate delayed-onset muscle soreness or ischaemic pain in human volunteers
Authors: Loram L.C. , Mitchell D. , Fuller A. 
Published: February 2006

We assessed the effect of rofecoxib, a cyclo-oxygenase-2 inhibitor, and tramadol, a centrally acting analgesic, on both delayed-onset muscle soreness (DOMS) and experimentally induced ischaemic pain. We induced DOMS in 10 male and 5 female healthy volunteers by downhill running for 30 min at a 12% decline and a speed of 9 km·h–1. We also induced ischaemic pain by finger movements with an arterial tourniquet around the arm. In a randomized, double-blind crossover format, we administered rofecoxib (50 mg, daily), tramadol (50 mg, 3 times per day), and a placebo (orally for 3 days), starting immediately after exercise. A 100 mm visual analogue scale (VAS) and McGill pain questionnaire were used to describe muscle soreness and ischaemic forearm pain 24 h after the exercise. The pressure pain threshold (PPT) in the thigh and ischaemic pain tolerance in the forearm were measured before exercise and 24 and 72 h after exercise. PPT decreased 24 h after exercise, compared with pre-exercise values (ANOVA, p < 0.05), but neither drug had any significant effect on the PPT. Neither rofecoxib nor tramadol had any effect on time of ischaemia tolerated or amount of finger activity during ischaemia. The VAS and pain-rating index, for both muscle soreness and experimental ischaemic pain, were not affected significantly by either drug. Both DOMS and ischaemic pain share peripheral and central mechanisms, yet neither are attenuated by rofecoxib or tramadol.
Serial magnetic resonance imaging based assessment of the early effects of an ACE inhibitor on postinfarction left ventricular remodeling in rats
Authors: Prunier Fabrice , Marescaux Laurent , Franconi Florence , Thia Alain , Legras Pierre , Lejeune Jean-Jacques , Furber Alain 
Published: February 2006

In vivo assessment of treatment efficacy on postinfarct left ventricular (LV) remodeling is crucial for experimental studies. We examined the technical feasibility of serial magnetic resonance imaging (MRI) for monitoring early postinfarct remodeling in rats. MRI studies were performed with a 7-Tesla unit, 1, 3, 8, 15, and 30 days after myocardial infarction (MI) or sham operation, to measure LV mass, volume, and the ejection fraction (EF). Three groups of animals were analyzed: sham-operated rats (n = 6), MI rats receiving lisinopril (n = 11), and MI rats receiving placebo (n = 8). LV dilation occurred on day 3 in both MI groups. LV end-systolic and end-diastolic volumes were significantly lower in lisinopril-treated rats than in placebo-treated rats at days 15 and 30. EF was lower in both MI groups than in the sham group at all time points, and did not differ between the MI groups during follow-up. Less LV hypertrophy was observed in rats receiving lisinopril than in rats receiving placebo at days 15 and 30. We found acceptable within- and between-observer agreement and an excellent correlation between MRI and ex vivo LV mass (r = 0.96; p < 0.001). We demonstrated the ability of MRI to detect the early beneficial impact of angiotensin-converting enzyme (ACE) inhibitors on LV remodeling. Accurate and noninvasive, MRI is the tool of choice to document response to treatment targeting postinfarction LV remodeling in rats.
LOCAL ACTIVITY IS THE ORIGIN OF COMPLEXITY
Authors: CHUA LEON O. 
Published: February 2006

Many scientists have struggled to uncover the elusive origin of "complexity", and its many equivalent jargons, such as emergence, self-organization, synergetics, collective behaviors, nonequilibrium phenomena, etc. They have provided some qualitative, but not quantitative, characterizations of numerous fascinating examples from many disciplines. For example, Schrödinger had identified "the exchange of energy" from open systems as a necessary condition for complexity. Prigogine has argued for the need to introduce a new principle of nature which he dubbed "the instability of the homogeneous". Turing had proposed "symmetry breaking" as an origin of morphogenesis. Smale had asked what "axiomatic" properties must a reaction–diffusion system possess to make the Turing interacting system oscillate. The purpose of this paper is to show that all the jargons and issues cited above are mere manifestations of a new fundamental principle called local activity, which is mathematically precise and testable. The local activity theorem provides the quantitative characterization of Prigogine's "instability of the homogeneous" and Smale's quest for an axiomatic principle on Turing instability. Among other things, a mathematical proof is given which shows none of the complexity-related jargons cited above is possible without local activity. Explicit mathematical criteria are given to identify a relatively small subset of the locally-active parameter region, called the edge of chaos, where most complex phenomena emerge.