bluuebunny/crossref_metadata_2025 huggingface dataset:
Lack of interferon‐beta bioactivity is associated with the occurrence of relapses in multiple sclerosis
Authors: Van Der Voort L. F. , Visser A. , Knol D. L. , Oudejans C. B. M. , Polman C. H. , Killestein J.
Published: May 2009

Background:  Treatment failure to Interferon‐beta (IFNβ) in multiple sclerosis (MS) can only partly be explained by anti‐IFNβ neutralising antibodies (NAb). Myxovirus resistance protein A (MxA) mRNA, reflecting IFNβ bioactivity, is studied as an alternative biomarker for IFNβ therapy response. Although absent IFNβ bioactivity is associated with NAb and NAb are associated with reduced drug efficacy, the direct relationship between IFNβ bioactivity and clinical disease activity is largely unknown.

Methods:  We enrolled 126 consecutive relapsing‐remitting MS patients on IFNβ treatment. MxA mRNA expression was assessed 4 h after IFNβ injection. Biological response status was determined after 3 months, by combined measurement of MxA mRNA expression and induction (MxA mRNA expression after/before IFNβ injection). Patients were considered biological non‐responders when both MxA mRNA expression and MxA mRNA induction were negative.

Results:  Biological non‐responders showed a significantly higher annualised relapse rate and smaller proportion relapse‐free patients compared with biological responders (relapse rate 0.81 vs. 0.37; proportion relapse free 37% vs. 67%).

Conclusions:  Our results suggest that a lack of IFNβ bioactivity is associated with the occurrence of relapses and therefore can be useful as a biomarker for unresponsiveness to IFNβ.
Cognitive deficits in multiple system atrophy correlate with frontal atrophy and disease duration
Authors: Chang C. C. , Chang Y. Y. , Chang W. N. , Lee Y. C. , Wang Y. L. , Lui C. C. , Huang C. W. , Liu W. L.
Published: May 2009

Background and purpose:  Dementia remains an exclusion criterion in diagnosing multiple system atrophy (MSA). This study aimed to determine the cognitive changes and brain atrophy patterns in the Parkinsonian (MSA‐P) and cerebellar (MSA‐C) variants of MSA.

Methods:  Voxel‐based morphometry (VBM) of magnetic resonance imaging (MRI) and neuro‐psychological tests were applied to 10 MSA‐C and 13 MSA‐P patients, and compared to 37 age‐matched controls. Correlation analyses were performed between cognitive test results and morphometric data extracted from the VBM data.

Results:  In neuro‐psychological testing, the 23 MSA patients scored lower in the Stroop interference test and took longer in the trail‐making test as compared with the controls, whereas MSA‐C performed worse than MSA‐P in the memory scores, Stroop test, and time to complete the trail‐making test. MSA, as a group, showed atrophy in the cerebellum, insular cortex, fusiform gyrus, inferior orbito‐frontal gyrus, superior temporal gyrus, and caudate nucleus. Memory scores correlated well with pre‐frontal lobe atrophy but not in the insular area.

Conclusion:  In conclusion, although dementia is not a typical presenting feature of MSA and is regarded as a sub‐cortical movement disorder, frontal atrophy, cognitive changes, and dementia are identifiable as MSA progresses.
Quantitative muscle ultrasound in neuromuscular disorders using the parameters ‘intensity’, ‘entropy’, and ‘fractal dimension’
Authors: Gdynia H.‐J. , Müller H.‐P. , Ludolph A. C. , Köninger H. , Huber R.
Published: May 2009

Background and purpose:  Ultrasound is a useful non‐invasive instrument in visualizing physiological and pathological morphology in skeletal muscle. Here, we evaluate the possibility that quantitative muscle ultrasound using the parameters ‘intensity’, ‘entropy’, and ‘fractal dimension’ is a feasible method to distinguish between dystrophic myopathies (DM), inflammatory myopathies (IM), and motor neuron disorders.

Methods:  Seven patients with IM, 12 patients with DM, nine patients with motor neuron diseases, and 24 healthy subjects underwent an identical ultrasound examination protocol, applied on gastrocnemius and tibialis anterior muscle. Analysis parameters were applied on grey scale images as well as on gradient images.

Results:  Statistical evaluation revealed no significant differences in the evaluated parameters for differentiation of the distinct disease groups. Compared with healthy controls however we found statistically significant differences between almost of all the investigated parameters, even in disease cases with clinically unaffected distal musculature.

Conclusion:  The parameters are able to distinguish between healthy and affected musculature but not between distinct disease entities. Studies are needed to establish whether or not the parameters are helpful to monitor muscle involvement and disease progression in neuromuscular diseases.
Configuration of the setal fields ofRhoptropus(Gekkota: Gekkonidae): functional, evolutionary, ecological and phylogenetic implications of observed pattern
Authors: Johnson Megan K. , Russell Anthony P.
Published: May 2009

Many gekkotans possess seta‐bearing adhesive subdigital pads. Details of setal structure, however, are largely based upon putatively exemplary fibrils deemed typical of the species. Little is known of the pattern of configuration of the setae across the subdigital pads and how great, if any, the variance in structure and dimensions is. To understand setal fields as functional entities, as opposed to individual setae, it is necessary to consider this pattern. Additionally, gekkotans within individual radiations occupy different environments and potentially are substrate‐specific in terms of the locomotor surface exploited. To investigate these issues, we herein examine the configuration and dimensions of seven species of the gekkotan genusRhoptropus, and an outgroup taxon,Chondrodactylus bibronii. All of these taxa are rupicolous and the array of rock surfaces exploited by this cluster of taxa is extensive. Our results show that setal field configuration follows a predictable pattern, both from one digit to another within a species, and between homologous digits and anatomical locations between species. One species,Rhoptropus afer, a more terrestrial taxon, exhibits significantly shorter setae and a smaller subdigital pad area than do its congeners, but exhibits the same overall pattern of setal arrangement. Our findings have implications for the understanding of the evolution of adhesive structures, and for the principles used for generating and manufacturing biomimetic artificial microfibrillar arrays.
A microstructural investigation of intervertebral disc lamellar connectivity: detailed analysis of the translamellar bridges
Authors: Schollum Meredith L. , Robertson Peter A. , Broom Neil D.
Published: May 2009

Little is known about the complex forces acting on the deformable multi‐layered annulus at a microstructural level as the spine is compressed, flexed and twisted. The recently described translamellar bridging network radially linking many lamellae at discrete locations around the disc wall could be expected to play a significant biomechanical role. In this study, segments of annular wall that were sectioned at a range of angles (oblique, in‐plane, sagittal and transverse) were examined using differential interference contrast microscopy to fully elucidate the fibrous detail of the translamellar bridging structures. Typically encompassing a width of 300–600 µm, translamellar bridging fibres proceed radially in the interbundle space within an individual lamella. Upon traversing the lamella, the bulk of these radial fibres bend through 90° to merge with the fibres of the adjacent lamellae. The central fibres of this bridging system continue into the equivalent bridging structures in the adjacent lamellae. As well as exposing structural details that underpin the biomechanical properties of the disc wall, this study has also exposed the limitations of using standard section planes commonly employed by disc researchers.
Myelin basic protein‐positive nerve fibres in human Meissner corpuscles
Authors: García‐Suárez O. , Montaño J. A. , Esteban I. , González‐Martínez T. , Alvarez‐Abad C. , López‐Arranz E. , Cobo J. , Vega J. A.
Published: May 2009

Myelinated nerve fibres forming sensory corpuscles become amyelinic before entering the corpuscle. Interestingly, in Meissner corpuscles from monkey myelin basic protein (MBP), a specific component of myelin sheath co‐localized with neuronal markers. To investigate whether or not this also occurs in human digital Meissner corpuscles, we used single and double immunohistochemistry to detect MBP associated with axonic (protein gene product (PGP) 9.5) or Schwann and Schwann‐related cell (S100 protein) markers. We also studied these markers in Pacinian corpuscles. Nerve fibres immunoreactive for MBP were detected in about 25% of the Meissner corpuscles examined; however, MBP never co‐localized with PGP 9.5 and MBP occasionally co‐localized with S100 protein. MBP‐immunoreactive fibres associated with Meissner corpuscles were observed at the periphery of the lamellar cells or within the corpuscle between the lamellar cells. These results describe the distribution of myelinated nerve fibres expressing MBP in human Meissner corpuscles, which is important when studying Meissner corpuscles in cutaneous biopsies used for the diagnosis of peripheral and degenerative neuropathies.
Three‐dimensional morphometric analysis of brain shape in nonsyndromic orofacial clefting
Authors: Weinberg Seth M. , Andreasen Nancy C. , Nopoulos Peg
Published: May 2009

Previous studies report structural brain differences in individuals with nonsyndromic orofacial clefts (NSOFC) compared with healthy controls. These changes involve non‐uniform shifts in tissue volume within the cerebral cortex and cerebellum, suggesting that the shape of the brain may be altered in cleft‐affected individuals. To test this hypothesis, a landmark‐based morphometric approach was utilized to quantify and compare brain shape in a sample of 31 adult males with cleft lip with or without cleft palate (CL/P), 14 adult males with cleft palate only (CPO) and 41 matched healthy controls. Fifteen midline and surface landmarks were collected from MRI brain scans and the resulting 3D coordinates were subjected to statistical shape analysis. First, a geometric morphometric analysis was performed in three steps: Procrustes superimposition of raw landmark coordinates, omnibus testing for group difference in shape, followed by canonical variates analysis (CVA) of shape coordinates. Secondly, Euclidean distance matrix analysis (EDMA) was carried out on scaled inter‐landmark distances to identify localized shape differences throughout the brain. The geometric morphometric analysis revealed significant differences in brain shape among all three groups (P < 0.001). From CVA, the major brain shape changes associated with clefting included selective enlargement of the anterior cerebrum coupled with a relative reduction in posterior and/or inferior cerebral portions, changes in the medio‐lateral position of the cerebral poles, posterior displacement of the corpus callosum, and reorientation of the cerebellum. EDMA revealed largely similar brain shape changes. Thus, compared with controls, major brain shape differences were present in adult males with CL/P and CPO. These results both confirm and expand previous findings from traditional volumetric studies of the brain in clefting and provide further evidence that the neuroanatomical phenotype in individuals with NSOFC is a primary manifestation of the defect and not a secondarily acquired characteristic.
Effect of refrigerated storage time on the viability of probiotic bacteria in fermented probiotic milk drinks
Authors: MOAYEDNIA NASRIN , EHSANI MOHAMAD R , EMAMDJOMEH ZAHRA , MAZAHERI AMIR F
Published: May 2009

The viability of Lactobacillus acidophilus and Bifidobacterium lactis in fermented milks A, B and AB, containing respectively these strains separately and mixed, was studied over 21 days of storage at 5°C. Samples were analysed for titratable acidity and viable cell counts of probiotics. Milks A and AB showed post‐acidification mainly due to the β‐galactosidase activity of L. acidophilus. Generally, the viability of the probiotics decreased during storage, whereas, in some cases, the proteoletic activity of L. acidophilus resulted in a higher survival rate of the probiotics even with the adverse effects of low temperature and organic acids.
Expression of p16INK4a in peripheral blood T‐cells is a biomarker of human aging
Authors: Liu Yan , Sanoff Hanna K. , Cho Hyunsoon , Burd Christin E. , Torrice Chad , Ibrahim Joseph G. , Thomas Nancy E. , Sharpless Norman E.
Published: May 2009

Expression of the p16INK4a tumor suppressor sharply increases with age in most mammalian tissues, and contributes to an age‐induced functional decline of certain self‐renewing compartments. These observations have suggested that p16INK4a expression could be a biomarker of mammalian aging. To translate this notion to human use, we determined p16INK4a expression in cellular fractions of human whole blood, and found highest expression in peripheral blood T‐lymphocytes (PBTL). We then measured INK4/ARF transcript expression in PBTL from two independent cohorts of healthy humans (170 donors total), and analyzed their relationship with donor characteristics. Expression of p16INK4a, but not other INK4/ARF transcripts, appeared to exponentially increase with donor chronologic age. Importantly, p16INK4a expression did not independently correlate with gender or body‐mass index, but was significantly associated with tobacco use and physical inactivity. In addition, p16INK4a expression was associated with plasma interleukin‐6 concentration, a marker of human frailty. These data suggest that p16INK4a expression in PBTL is an easily measured, peripheral blood biomarker of molecular age.
Getting to the Meat of the Matter: Beyond Protein Supplementation in Maintenance Dialysis
Authors: Bailey James L. , Franch Harold A.
Published: May 2009

Until recently, patients on dialysis with low serum albumin levels were characterized as suffering from protein malnutrition suggesting that the cause of this malady was due to an inadequate intake of protein. In fact, these patients tend to suffer from a wasting syndrome similar to cachexia commonly associated with inflammation in which there is loss of lean body mass and fat mass is underutilized. The term protein energy wasting has been used to characterize this syndrome and suggests that the simple addition of protein supplements to the dietary regimen of hemodialysis patients will not cure this malady. Correction of the underlying inflammatory disorder which drives losses of body protein and fuel reserves is far more important and is the single most effective therapy. Protein supplements which may promote albumin synthesis and synthesis of liver‐related proteins tend to increase muscle catabolism. Muscle growth is not fostered by increasing dietary protein above recommended goals for dialysis patients, but can be promoted by the addition of protein of high biological value that is rich in leucine and other essential amino acids in tandem with repetitive exercises. Ultimately, correction of PEW hinges on the diagnosis and treatment of co‐morbid conditions in combination with strategies to replenish caloric and protein stores. A supplementary exercise program would allow recovery of lean body mass. Given the multiple co‐morbidities that exist in this population, therapy would have to be individualized.
“I GOT YOUR BACK”: AN EXAMINATION OF THE PROTECTIVE FUNCTION OF GANG MEMBERSHIP IN ADOLESCENCE*
Authors: MELDE CHRIS , TAYLOR TERRANCE J. , ESBENSEN FINN‐AAGE
Published: May 2009

The threat of victimization has been regarded as a central feature in both the development and the continuation of youth gangs. Although many studies find the need for protection to be a common reason youth join gangs, recent literature suggests that gang members are at an increased risk of victimization. Given this seeming contradiction between expectations and reality, the current article examines the “objective” and “subjective” dimensions of gang member victimization using panel data collected from youth between the ages of 10 and 16 years. Findings reveal that gang members report higher levels of actual victimization and perceptions of victimization risk than non‐gang‐involved youth. Gang membership is associated with reduced levels of fear, however. Overall, although gangs may not be functional in terms of actual victimization, they seem to decrease anxiety associated with the threat of future victimization.
TRENDS IN THE GENDER GAP IN VIOLENT OFFENDING: NEW EVIDENCE FROM THE NATIONAL CRIME VICTIMIZATION SURVEY*
Authors: LAURITSEN JANET L. , HEIMER KAREN , LYNCH JAMES P.
Published: May 2009

Recent research has compared male and female trends in violent offending in Uniform Crime Report (UCR) arrest data with similar trends derived from victims' reports in the National Crime Victimization Survey (NCVS) and has concluded that the two data sources produce contrary findings. In this article, we reassess this issue and draw different conclusions. Using pooled National Crime Survey (NCS) and NCVS data for 1973 to 2005, we find that the female‐to‐male offending rate ratios for aggravated assault, robbery, and simple assault have increased over time and that the narrowing of the gender gaps is very similar to patterns in UCR arrest data. In addition, we find that these patterns are in part caused by larger decreases in male than female offending after the mid‐1990s and not by recent increases in violent offending rates among females. We conclude that changes in the gender gaps in aggravated assault, robbery, and simple assault are real and not artifacts; therefore, these changes deserve serious attention in future research. We conclude with a discussion of several hypotheses that might account for a narrowing of the gender gap in nonlethal violent offending over time.
INTERGROUP AND INTRAGROUP VIOLENCE: IS VIOLENT CRIME AN EXPRESSION OF GROUP CONFLICT OR SOCIAL DISORGANIZATION?*
Authors: HIPP JOHN R. , TITA GEORGE E. , BOGGESS LYNDSAY N.
Published: May 2009

The impact of residential turnover and compositional change at the neighborhood level on local patterns of crime lies at the center of most ecological studies of crime and violence. Of particular interest is how racial and ethnic change impacts intragroup and intergroup crime. Although many studies have examined this effect using city‐level data, few have evaluated it using neighborhood‐level data. Using incident‐level data for the South Bureau Policing Area of the Los Angeles Police Department aggregated to census tracts, we use a novel methodology to construct intragroup and intergroup rates of robbery and assaults. The South Bureau has experienced dramatic demographic change as it has transitioned from a predominately African‐American area to a predominately Latino area. We find support for the social disorganization model, as racial/ethnic transition in nearby tracts leads to greater levels of intergroup violence by both groups as well as to more intragroup violence by Latinos. Such neighborhoods seem to experience a breakdown in norms, which leads to higher levels of violence in all forms. Particularly noteworthy is that intragroup crime is highest in all settings, which includes the most heterogeneous tracts. We also find support for the consolidated inequality theory, as greater inequality across the two groups leads to more violence by the disadvantaged group.
Evaluation of the centreing ability of the ProTaper Universal™ rotary system in curved roots in comparison to Nitiflex™ files
Authors: Aguiar Carlos Menezes , De Andrade Mendes Daniela , Câmara Andréa Cruz , De Figueiredo Jose Antonio Poli
Published: May 2009

The aim of the present study was to assess the centreing ability of the ProTaper Universal™ rotary system in curved roots in comparison to Nitiflex™ files, by means of preoperative and postoperative imaging of a cross‐section of the apical third. Twenty mesiobuccal canals of human first mandibular molars with a degree of curvature ranging from 35° to 60° were divided into two groups of 10 specimens each: group 1, ProTaper Universal™ rotary system; group 2 (control), Nitiflex™ files. All instruments produced morphological alterations. The Student's t‐test and Kruskal–Wallis test showed that the differences were not statistically significant, except for the specimens instrumented by Nitiflex file #30. The ProTaper Universal™ showed the capacity for producing centered preparations in curved and thin root canals with low proportions of apical deviation.
Safety of laser use under the dental microscope
Authors: Saegusa Hidetoshi , Watanabe Satoshi , Anjo Tomoo , Ebihara Arata , Suda Hideaki
Published: May 2009

The aim of this study was to investigate the safety of laser use under the dental microscope. Nd:YAG, Er:YAG and diode lasers were used. The end of the tips was positioned at a distance of 5 cm from the objective lens of a dental microscope. Each eye protector was made into a flat disc, which was fixed on the lens of the microscope. The filters were placed in front of the objective lens or behind the eye lens. Transmitted energy through the microscope with or without the filters was measured. No transmitted laser energy was detected when using matched eye protectors. Mismatched eye protectors were not effective for shutting out laser energy, especially for Nd:YAG and diode lasers. None or very little laser energy was detected through the microscope even without any laser filter. Matched filters shut out all laser energy irrespective of their positions.
Changes in Dynamic and Kinematic Properties of Saccades in Ocular Myasthenia following Intravenous Immunoglobulin Treatment
Authors: Serra Alessandro , Thurtell Matthew J. , Leigh R. John
Published: May 2009

The dynamics and kinematics of saccades in a patient with severe ocular myasthenia were studied before and after treatment with intravenous immunoglobulin (IVIG). Before therapy, horizontal saccades were hypometric, but faster than similar‐sized saccades made by normal subjects. During a 5‐minute test period, saccades decreased in size (fatigue effect), but remained faster than those of controls. Listing's plane of the eye with greater ophthalmoplegia was increased in thickness. After IVIG treatment, the range of eye movements improved, but saccades remained faster than those of controls. Also, no fatigue was observed and the thickness of Listing's plane was reduced toward the normal range. Increased peak velocity, despite progressive hypometria due to fatigue, supports the hypothesis that the pale global extraocular muscle fibers are relatively spared in myasthenia. Involvement of other extraocular muscle‐fiber types leads to limited range of eye movements and an increase in the thickness of Listing's plane.
Upbeat‐Torsional Nystagmus and Contralateral Fourth‐Nerve Palsy due to Unilateral Dorsal Ponto Mesencephalic Lesion
Authors: Thurtell Matthew J. , Tomsak Robert L. , Leigh R. John
Published: May 2009

The central projections of the anterior semicircular canals are thought to be conveyed from the vestibular nuclei to the oculomotor nuclei in the midbrain by three distinct brainstem pathways: the medial longitudinal fasciculus, crossing ventral tegmental tract, and brachium conjunctivum. There is controversy as to whether upbeat nystagmus could result from lesions involving each of these pathways. We report a 52‐year‐old man who presented with a contralesional fourth‐nerve palsy and primary‐position upbeat‐torsional nystagmus due to a small unilateral dorsal pontomesencephalic lymphomatous deposit. It is postulated that the upbeat‐torsional nystagmus was caused by involvement of the brachium conjunctivum, which lies adjacent to the fourth‐nerve fascicles at the dorsal pontomesencephalic junction, but involvement of the crossing ventral tegmental tract cannot be excluded. These observations suggest that, in humans, excitatory upward‐torsional eye movement signals from the anterior semicircular canals could be partly conveyed to the midbrain by the brachium conjunctivum.
Distinct Roles for Eye and Head Movements in Selecting Salient Image Parts during Natural Exploration
Authors: Einhäuser Wolfgang , Schumann Frank , Vockeroth Johannes , Bartl Klaus , Cerf Moran , Harel Jonathan , Schneider Erich , König Peter
Published: May 2009

Humans adjust gaze by eye, head, and body movements. Certain stimulus properties are therefore elevated at the gaze center, but the relative contribution of eye‐in‐head and head‐in‐world movements to this selection process is unknown. Gaze‐ and head‐centered videos recorded with a wearable device (EyeSeeCam) during free exploration are reanalyzed with respect to responses of a face‐detection algorithm. In line with results on low‐level features, it was found that face detections are centered near the center of gaze. By comparing environments with few and many true faces, it was inferred that actual faces are centered by eye and head movements, whereas spurious face detections (“hallucinated faces”) are primarily centered by head movements alone. This analysis suggests distinct contributions to gaze allocation: head‐in‐world movements induce a coarse bias in the distribution of features, which eye‐in‐head movements refine.
Functional Magnetic Resonance Imaging Activations of Cortical Eye Fields during Saccades, Smooth Pursuit, and Optokinetic Nystagmus
Authors: Dieterich Marianne , Müller‐Schunk Stefanie , Stephan Thomas , Bense Sandra , Seelos Klaus , Yousry Tarek A.
Published: May 2009

Saccades, smooth pursuit, and optokinetic nystagmus (OKN) are three basic eye movements in our ocular motor repertoire that enable us to explore the visual field. These eye movements are cortically controlled in different cortical eye fields, including the frontal eye fields (FEF) and parietal eye fields (PEF), as well as the motion‐sensitive visual area MT+/V5. It is not known if this cortical control is organized in parallel cortico–cortical networks or in adjacent subregions of one system. Nor do we know where the specific eye fields are exactly located. Functional magnetic resonance imaging (fMRI) was used to investigate these open questions about the FEF, PEF, and MT+/V5. Activations of the cortical network of eye‐movement control were found in the frontal, parietal, and occipital cortex. While the activation pattern for OKN was not a combination of the patterns for saccades and smooth pursuit, the results suggest that cortical control of OKN occurs in a network parallel to that of saccades and smooth pursuit. Furthermore, a division of the FEF and the PEF into two parts was confirmed for the three ocular motor tasks, as well as a division within each of the three paradigms. MT+/V5 showed two partitions only for saccades, but not for smooth pursuit or OKN.
Lateral Canal Paroxysmal Positional Vertigo Revisited
Authors: Nuti Daniele , Mandalà Marco , Salerni Lorenzo
Published: May 2009

The first reports of an involvement of the lateral canal (LC) in paroxysmal positional vertigo (PPV), were published in 1985, by Luciano Cipparrone et al., from Italy and Joseph McClure from Canada. The increasing interest of otolaryngologists and neurologists has led to a progressive advance in the knowledge of this labyrinthine disorder regarding its epidemiological, physiopathological, clinical, and therapeutic aspects. According to the most recent data, LC–benign PPV accounts for 17% of all PPV patients, regardless of gender and between the two labyrinths. The LC–PPV syndrome is characterized by intense positional vertigo and direction‐changing geotropic horizontal nystagmus, both caused by rotation of the head in the supine position. Less frequently, it presents with apogeotropic nystagmus. In some patients nystagmus is also detectable in the sitting position, mimicking a spontaneous nystagmus. In most cases nystagmus is caused by displaced otoconia floating in the semicircular canal. The pathological side, which must be identified for successful treatment, is usually indicated by nystagmus intensity: the more intense positional nystagmus beats toward the affected ear. In a few cases, where there is no difference in nystgmus intensity, other indicators are necessary to determine the pathological side. Vestibular neuritis and posterior fossa lesions should be considered in the differential diagnosis. Treatment of LC–PPV relies on some physical maneuvers, the objective of which is to allow the otoconial debris to exit from the LC by centrifugal inertia and/or by gravitation.
Why Do Patients with Impaired Vergence Not Show “Saccadic” Vergence?
Authors: Rambold Holger , Sander Thurid , Sprenger Andreas , Helmchen Christoph
Published: May 2009

Low gain of the smooth‐pursuit system causes correcting saccades that are clinically observed as “saccadic pursuit.” In contrast, low gain of the vergence system during tracking does not appear to cause “saccadic tracking.” To further evaluate whether this clinical observation is caused by a missing interaction of vergence to step and ramp targets, vergence eye movements to step–ramp, step, and ramp targets in 3‐dimensional space were tested. Results show that vergence to a step and a ramp stimulus is additive in the step–ramp paradigm, indicating no interaction of both components.
The Configuration and Attachment of the Utricular and Saccular Maculae to the Temporal Bone
Authors: Curthoys Ian S. , Uzun‐Coruhlu Hilal , Wong Chris C. , Jones Allan S. , Bradshaw Andrew P.
Published: May 2009

High‐resolution X‐ray microtomography (micro‐CT) was used to show the spatial configuration of the membranous labyrinth of the fixed guinea pig and human inner ear. Whole temporal bones were en bloc stained in 2% osmium tetroxide for 2 days or more to allow the osmium to attach to the membranes of the inner ear, and then scanned with a Skyscan 1172 micro‐CT with highest resolution of 8 microns. The scans were segmented and reconstructed. The findings for guinea pigs and humans are similar. The saccular macula is closely attached to the curved medial wall of the temporal bone, but in both human and guinea pig the utricular macula is attached to the temporal bone only at the anterior region of the macula, and, as others have reported previously, much of the caudal area of the utricular macula is tenuously supported by a thin membrane, just above the dorsal margin of the stapes. This tenuous support may have important consequences for the sensing of forces by the utricular macula. Combining information from a dissected human horizontal canal with CT images allows an estimate of the orientation of the horizontal canal crista in human subjects, data which are necessary for treatment of benign paroyxsmal positional vertigo of the horizontal canal. The very high resolution achieved by micro‐CT shows that reconstruction from inadequately sampled CT data produces images that are not anatomically correct, so that canal deformations and aplasias may appear to be present.
Tell Me Your Vestibular Deficit, and I’ll Tell You How You’ll Compensate
Authors: Lacour Michel , Dutheil Sophie , Tighilet Brahim , Lopez Christophe , Borel Liliane
Published: May 2009

Most patients with unilateral vestibular loss exhibit a similar static and dynamic vestibular syndrome consisting of vestibulo‐ocular, posturolocomotor, and perceptive deficits. This vestibular syndrome recovers more or less completely and more or less rapidly over time. One open question is whether recovery mechanisms differ according to vestibular pathology and/or patients. It is reported here (1) data from three different cat models of unilateral vestibular loss reproducing vestibular pathology with sudden (unilateral vestibular neurectomy [UVN] model), gradual (unilateral labyrinthectomy [UL] model), or reversible (tetrodotoxine [TTX]) model) loss of vestibular function, and (2) clinical observations in a population of unilateral vestibular loss patients suffering the same pathology (Menière's disease). Animal models show that time courses and mechanisms of recovery depend on the type of vestibular deafferentation, and clinical findings show that Menière's patients compensate their postural and perceptive deficits using different vicarious processes. Taken together, results point to a more complex picture of compensation after unilateral vestibular loss, which cannot be reduced either to a common recovery mechanism or to a single process identical for all individuals. These findings should guide physiotherapists in treatment and rehabilitation for vestibular deficits.
Galvanic Vestibular Stimulation Combines with Earth‐Horizontal Rotation in Roll to Induce the Illusion of Translation
Authors: Schneider Erich , Bartl Klaus , Glasauer Stefan
Published: May 2009

Human head rotation in roll around an earth‐horizontal axis constitutes a vestibular stimulus that, by its rotational component, acts on the semicircular canals (SCC) and that, by its tilt of the gravity vector, also acts on the otoliths. Galvanic vestibular stimulation (GVS) is thought to resemble mainly a rotation in roll. A superposition of sinusoidal GVS with a natural earth‐horizontal roll movement was therefore applied in order to cancel the rotation effects and to isolate the otolith activation. By self‐adjusting the amplitude and phase of GVS, subjects were able to minimize their sensation of rotation and to generate the perception of a linear translation. The final adjustments are in the range of a model that predicts SCC activation during natural rotations and GVS. This indicates that the tilt‐translation ambiguity of the otoliths is resolved by SCC–otolith interaction. It is concluded that GVS might be able to cancel rotations in roll and that the residual tilt of the gravitoinertial force is possibly interpreted as a linear translation.
Reafferent Head‐Movement Signals Carried by Pursuit Neurons of the Simian Frontal Eye Fields during Head Movements
Authors: Fukushima Kikuro , Kasahara Satoshi , Akao Teppei , Saito Hiroshi , Kurkin Sergei , Fukushima Junko , Peterson Barry W.
Published: May 2009

The smooth‐pursuit system is important to precisely track a slowly moving object and maintain its image on the foveae during movement. During whole‐body rotation, the smooth‐pursuit system interacts with the vestibular system. The caudal part of the frontal eye fields (FEF) contains smooth pursuit–related neurons that signal eye velocity during pursuit. The majority of them receives vestibular inputs and signal gaze‐velocity during passive whole‐body rotation. It was asked whether discharge modulation of FEF pursuit neurons during head rotation on the stationary trunk could be accounted for by vestibular inputs only or if both vestibular and neck proprioceptive inputs contributed to the modulation. Discharge modulation during active head pursuit, passive head rotation on the stationary trunk, passive whole‐body rotation, and passive trunk rotation against the stationary head were compared. The results indicate that both vestibular and neck proprioceptive inputs contributed to the discharge modulation of FEF pursuit neurons during head movements.
Reversal of Initial Positioning Nystagmus in Benign Paroxysmal Positional Vertigo Involving the Horizontal Canal
Authors: Lee Seung‐Han , Kim Myeong‐Kyu , Cho Ki‐Hyun , Kim Ji Soo
Published: May 2009

In benign paroxysmal positional vertigo (BPPV), spontaneous reversal of the initial positioning nystagmus rarely occurs without further position changes. We analyzed the characteristics of spontaneous reversal of the initial head‐turning nystagmus in 21 patients with BPPV involving the horizontal semicircular canal. All patients showed initial geotropic nystagmus (first‐phase nystagmus) on head turning to either side while supine, which was followed by spontaneous reversal (second‐phase nystagmus). The reversal was either unilateral (n = 16) or bilateral (n = 5). The maximal slow phase velocity (SPV) and duration of the first‐phase nystagmus were greater and shorter than those of the second‐phase nystagmus. The reversal group showed greater maximal SPVs of the initial nystagmus in either ipsi‐ or contralesional direction than the control group. BPPV resolved after particle repositioning maneuver (PRM) in most patients. However, one patient showed persistent apogeotropic nystagmus after PRM. Short‐term adaptation of the vestibulo‐ocular reflex seems to be the main mechanism of spontaneous reversal of the initial positioning nystagmus. However, coexistence of canalo‐ and cupulolithiasis should be considered in the patient showing bilateral spontaneous reversal.
Causative Factors, Epidemiology, and Follow‐up of Bilateral Vestibulopathy
Authors: Zingler Vera Carina , Weintz Eva , Jahn Klaus , Huppert Doreen , Cnyrim Christian , Brandt Thomas , Strupp Michael
Published: May 2009

Bilateral vestibulopathy (BV) is characterized by impaired or lost function of both peripheral labyrinths or of the eighth nerves. In a review of 255 patients (mean age ± SD, 62 ± 16 years) with BV diagnosed in the authors’ dizziness unit between 1988 and 2005, 62% of the patients were male. Previous vertigo attacks had occurred in 36%, indicating a sequential manifestation. The definite cause of BV was determined in 24% and the probable cause in 25%. The most common causes were ototoxic aminoglycosides (13%), Ménière's disease (7%), and meningitis (5%). Strikingly, 25% exhibited cerebellar signs. Cerebellar dysfunction was associated with peripheral polyneuropathy in 32% compared with 18% in BV patients without cerebellar signs. In a follow‐up study on 82 BV‐patients (mean age at the time of diagnosis 56.3 ± 17.6 years), the frequency and degree of recovery or worsening of vestibular function over time were determined. The patients were reexamined 51 ± 6 months after the first examination. Electronystagmography with bithermal caloric irrigation was analyzed by measurement of the mean peak slow‐phase velocity (SPV) of the induced nystagmus. Statistical analysis of the mean peak SPV revealed a nonsignificant worsening over time (initial mean peak SPV 3.0 ± 3.5°/s vs. 2.1 ± 2.8°/s). Only patients with BV due to meningitis exhibited an increasing, but nonsignificant SPV (1.0 ± 1.4°/s vs. 1.9 ± 1.6°/s). Forty‐three percent of patients subjectively rated the course of their disease as stable, 28% as worsened, and 29% as improved.
Driving Dreams
Authors: Flanagin Virginia L. , Wutte Magdalena , Glasauer Stefan , Jahn Klaus
Published: May 2009

It is unclear how subjects perceive and process self‐motion cues in virtual reality environments. Movement could be perceived as passive, akin to riding in a car, or active, such as walking down the street. These two very different types of self‐motion were studied here using motor imagery in fMRI. In addition, the relative importance of visual and proprioceptive training cues was examined. Stronger activations were found during proprioceptive motor imagery compared with visual motor imagery, suggesting that proprioceptive signals are important for successful imagined movement. No significant activations were found during active movement with proprioceptive training. Passive locomotion, however, was correlated with activity in an occipital‐parietal and parahippocampal cortical network, which are the same regions found during navigation with virtual reality stimuli.
Modality‐dependent Indication of the Subjective Vertical during Combined Linear and Rotational Movements
Authors: Guenther Anna L. , Bartl Klaus , Nauderer Josef , Schneider Erich , Huesmann Alexander , Brandt Thomas , Glasauer Stefan
Published: May 2009

Humans can discriminate whether a change in the direction of gravito‐inertial force (GIF) is caused by body tilt or by linear translation. This ability, attributed to vestibular sensory fusion, is often examined by asking subjects to adjust an indicator to match their subjective earth‐fixed vertical (SV). We used two different modalities, visual and haptic, to examine continuous adjustment during different combinations of roll rotation and linear translation on a hexapod motion device. We conclude that, in conditions of combined translational and rotational motion, the modality of indication plays a major role for the perception of verticality of the indicator.
Estimating the Time Constants of the rVOR
Authors: Ramat S. , Bertolini G.
Published: May 2009

Single‐unit recordings of vestibular afferents from the semicircular canals of squirrel monkeys have shown that the cupular time constant (Tc) is between 5 and 6 sec. Such recordings obviously cannot be performed in humans, and the corresponding values have thus been inferred to be somewhat longer based on their size and on the cupula‐endolymph system. The ocular motor response of the rotational vestibulo‐ocular reflex (rVOR) is characterized by longer time constants, typically between 15 and 20 sec, due to the so‐called velocity storage mechanism (VSM), which prolongs the time constant of the afferents through central processing. Recent studies have attempted to determine the time constant of the cupula by fitting the slow phase velocity (SPV) of the response to postrotational stimuli using a mathematical model of the rVOR processing. To this goal they considered the processing of head velocity due to the peripheral vestibular organs and to the VSM. The resulting estimates of Tc are lower than expected, averaging about 4 sec. These modeling approaches, though, neglect both the processing of the final common pathway and the adaptation shown by the discharge of primary vestibular afferents. Here we argue that such an approach may be bound to underestimate the duration of the rVOR time constants.
Spatial Neglect: Hypothetical Mechanisms of Disturbed Interhemispheric Crosstalk for Orientation
Authors: Brandt Thomas , Glasauer Stefan , Strupp Michael , Dieterich Marianne
Published: May 2009

Schematic drawings are presented of the major anatomical structures involved, along with their functional excitatory and inhibitory connections as the basis of a hypothetical model of visuospatial neglect. It is assumed that multisensory integration centers for attention and orientation (MSO) are represented in the temporo‐parietal cortex of both hemispheres, with the dominant MSO being in the right hemisphere (nondominant hemisphere in right‐handedness). A lesion of the dominant MSO will cause a left‐sided neglect due to a lack of ipsilateral activation of the visual cortex, which is further enhanced by increased inhibition from the contralateral visual cortex. The nondominant MSO in the left hemisphere might be involved in the manifestation of the less frequent and more transient right‐sided neglect and in the plastic mechanisms of gradual recovery from a left‐sided neglect or extinction.
The Intensity of Downbeat Nystagmus during Daytime
Authors: Spiegel Rainer , Rettinger Nicole , Kalla Roger , Lehnen Nadine , Straumann Dominik , Brandt Thomas , Glasauer Stefan , Strupp Michael
Published: May 2009

On the basis of reports by patients with downbeat nystagmus (DBN) that their symptoms were worse during the morning but better during the daytime, we investigated whether the intensity of DBN changes during the daytime. DBN was measured at 9 am, 11 am, and 1 pm. The mean peak slow phase velocity (MPSPV) of DBN was determined in different eye positions, with and without fixation, as well as in three different body positions: sitting upright, lying supine with the nose up, and lying prone with the nose down. Twelve patients with DBN either due to cerebellar degeneration or of idiopathic etiology were examined. The major findings of this study were as follows. First, the intensity of DBN significantly decreased during the daytime. When measured in the sitting upright position and primary eye position, MPSPV decreased from 4.32 deg/sec (±SEM 1.02) at 9 am to 2.12 deg/sec (± 0.5) at 11 am (P < 0.01) and stayed constant around 1.93 deg/sec (± 0.57) at 1 pm (P < 0.01 from 9 am to 1 pm) and 2.08 deg/sec (± 0.75) at 3 pm (P < 0.01 from 9 am to 3 pm). Second, this change did not depend on fixation during the measurements. Third, this effect was not influenced by the eye position during the measurements (upward, downward, or straight ahead). Our data show that the intensity of DBN decreases during the daytime. This decrease correlates with the symptoms of the patients. This change during daytime did not depend on visual fixation. Another possible mechanism is the modulation of DBN by head position relative to gravity, that is, by otolith input. This should be evaluated in further studies.
How Actions Alter Sensory Processing
Authors: Cullen Kathleen E. , Brooks Jessica X. , Sadeghi Soroush G.
Published: May 2009

Our vestibular organs are simultaneously activated by our own actions as well as by stimulation from the external world. The ability to distinguish sensory inputs that are a consequence of our own actions (vestibular reafference) from those that result from changes in the external world (vestibular exafference) is essential for perceptual stability and accurate motor control. Recent work in our laboratory has focused on understanding how the brain distinguishes between vestibular reafference and exafference. Single‐unit recordings were made in alert rhesus monkeys during passive and voluntary (i.e., active) head movements. We found that neurons in the first central stage of vestibular processing (vestibular nuclei), but not the primary vestibular afferents, can distinguish between active and passive movements. In order to better understand how neurons differentiate active from passive head motion, we systematically tested neuronal responses to different combinations of passive and active motion resulting from rotation of the head‐on‐body and/or head‐and‐body in space. We found that during active movements, a cancellation signal was generated when the activation of proprioceptors matched the motor‐generated expectation.
The Gilbert Henderson Oration*
Authors: Sutherland K. J. G.
Published: May 2009

In expressing my gratitude for the honour of having been invited to deliver this Oration, I would like in turn to pay tribute to one of our esteemed dental colleagues who has dedicated his life so wholeheartedly and so sincerely to the profession for more than half a century.

No other dentist has identified himself more closely with the image of dentistry in Western Australia than has the President of this 17th Australian Dental Congress, and I would like to suggest that the title of this address, hitherto undedicated, be known as the Gilbert Henderson Oration.
Hardness and strength properties of a new “high impact” denture base resin
Authors: Leong A. , Harcourt J. K.
Published: May 2009

Abstract— Comparison of transverse strengths and hardnesses of a polyhydroxyethyl methacrylate and of a polymethyl methacrylate shows the former to be inferior in the three tests.
Ultrasonic scaling
Authors: Jacobson Lars
Published: May 2009

Abstract— A review of the uses and limitations of ultrasonic scaling is presented. Two instruments are described and procedures to be followed in the use of the method are given.
Dental Therapists in South Australia
Authors: Blaikie D. C.
Published: May 2009

Abstract— The development of the School of Dental Therapy in Adelaide, the education and employment of dental therapists in the School Dental Service section of the South Australian Department of Public Health has been described. The direction and supervision of dental therapists and the clinical duties which may be delegated to them have been reported.
Clinical control charts
Authors: Thomas W.
Published: May 2009

Abstract— Using a modified DMF index from existing data a method, based on the amount of treatment previously received, is demonstrated for constructing control charts for assessing the effectiveness of and for detecting trends in a school dental service.
The effect of age and the duration of diabetes mellitus on the width of the basement membrane of small vessels
Authors: Campbell M. J. A.
Published: May 2009

Abstract— Measurement shows that the basement membrane of small vessels from nine diabetic patients and eight non‐diabetic patients aged 9–20 years, is larger in the diabetic patient and that the membrane widens with increased duration of diabetes mellitus rather than the aging of the patient.
An aid for the manipulation of partial dentures by handicapped patients
Authors: Price Peter A. S.
Published: May 2009

Abstract— A device is described which enables manually handicapped patients to insert and remove partial dentures.