6 research outputs found
Intentional Unilateral Epidural Block for Surgery in a Pregnant Patient
Unilateral epidural block often results inadvertently during routine epidurals. It can however be used intentionally to provide analgesia selectively to thelimb being operated. We present an application of this approach used to provide surgical anaesthesia and postoperative analgesia to a patient whosustained fracture of her right femur during second trimester of pregnancy and required open reduction
Development of the inner ear
The vertebrate inner ear is a sensory organ of exquisite design and sensitivity. It responds to sound, gravity and movement, serving both auditory (hearing) and vestibular (balance) functions. Almost all cell types of the inner ear, including sensory hair cells, sensory neurons, secretory cells and supporting cells, derive from the otic placode, one of the several ectodermal thickenings that arise around the edge of the anterior neural plate in the early embryo. The developmental patterning mechanisms that underlie formation of the inner ear from the otic placode are varied and complex, involving the reiterative use of familiar signalling pathways, together with roles for transcription factors, transmembrane proteins, and extracellular matrix components. In this review, I have selected highlights that illustrate just a few of the many recent discoveries relating to the development of this fascinating organ system
Peripheral vestibular dysfunction in patients With primary ciliary dyskinesia
This is an accepted manuscript of an article published by Lippincott, Williams and Wilkins in Otology and Neurotology in April 2015, available online: https://doi.org/10.1097/MAO.0000000000000592
The accepted version of the publication may differ from the final published version.Hypothesis
Patients with primary ciliary dyskinesia (PCD) have absent or reduced otoconial function compared to the normal population.
Background
Investigations in zebrafish show that ciliation is important for the development of the otolith organs, but this has never been evaluated in humans. PCD is a congenital defect of ciliary structure. We undertook a pilot study to determine whether patients with PCD have absent or reduced otoconial function compared to the normal population.
Methods
Vestibular function testing, including utricular centrifugation (UCF) testing, vestibular evoked myogenic potentials (VEMPs), and electronystagmography, was undertaken in five patients with known PCD. Patients also completed validated questionnaires regarding subjective balance function and symptoms.
Results
There were markedly reduced or unobtainable VEMPs bilaterally in three of the five subjects and unilaterally in the remaining two subjects. No subject had a pathological UCF asymmetry, but three subjects showed utricular abnormalities. The vestibulo-ocular reflex (VOR) at 0.25 Hz sinusoidal rotation was normal in all subjects. There were no subjective dizzy symptoms or balance issues.
Conclusion
We speculate that the reduced saccular and utricular function in PCD patients observed in this pilot study suggests a relationship between cilia structure and/or motility, and otoconia seeding and/or positioning. Further investigation is warranted.Published versio
Peripheral Vestibular Dysfunction in Patients With Primary Ciliary Dyskinesia
Hypothesis: Patients with primary ciliary dyskinesia (PCD) have absent or reduced otoconial function compared to the normal population.
Background: Investigations in zebrafish show that ciliation is important for the development of the otolith organs, but this has never been evaluated in humans. PCD is a congenital defect of ciliary structure. We undertook a pilot study to determine whether patients with PCD have absent or reduced otoconial function compared to the normal population.
Methods: Vestibular function testing, including utricular centrifugation (UCF) testing, vestibular evoked myogenic potentials (VEMPs), and electronystagmography, was undertaken in five patients with known PCD. Patients also completed validated questionnaires regarding subjective balance function and symptoms.
Results: There were markedly reduced or unobtainable VEMPs bilaterally in three of the five subjects and unilaterally in the remaining two subjects. No subject had a pathological UCF asymmetry, but three subjects showed utricular abnormalities. The vestibulo-ocular reflex (VOR) at 0.25 Hz sinusoidal rotation was normal in all subjects. There were no subjective dizzy symptoms or balance issues.
Conclusion: We speculate that the reduced saccular and utricular function in PCD patients observed in this pilot study suggests a relationship between cilia structure and/or motility, and otoconia seeding and/or positioning. Further investigation is warranted
Measurement of the diffractive cross-section in deep inelastic scattering
Diffractive scattering of , where is either a
proton or a nucleonic system with ~GeV has been measured in deep
inelastic scattering (DIS) at HERA. The cross section was determined by a novel
method as a function of the c.m. energy between 60 and 245~GeV
and of the mass of the system up to 15~GeV at average values of
14 and 31~GeV. The diffractive cross section is,
within errors, found to rise linearly with . Parameterizing the
dependence by the form d\sigma^{diff}/dM_X \propto
(W^2)^{(2\overline{\mbox{\alpha_{_{I\hspace{-0.2em}P}}}} -2)} the DIS data
yield for the pomeron trajectory
\overline{\mbox{\alpha_{_{I\hspace{-0.2em}P}}}} = 1.23 \pm 0.02(stat) \pm
0.04 (syst) averaged over in the measured kinematic range assuming the
longitudinal photon contribution to be zero. This value for the pomeron
trajectory is substantially larger than
\overline{\mbox{\alpha_{_{I\hspace{-0.2em}P}}}} extracted from soft
interactions. The value of \overline{\mbox{\alpha_{_{I\hspace{-0.2em}P}}}}
measured in this analysis suggests that a substantial part of the diffractive
DIS cross section originates from processes which can be described by
perturbative QCD. From the measured diffractive cross sections the diffractive
structure function of the proton F^{D(3)}_2(\beta,Q^2,
\mbox{x_{_{I\hspace{-0.2em}P}}}) has been determined, where is the
momentum fraction of the struck quark in the pomeron. The form F^{D(3)}_2 =
constant \cdot (1/ \mbox{x_{_{I\hspace{-0.2em}P}}})^a gives a good fit to
the data in all and intervals with $a = 1.46 \pm 0.04 (stat) \pmComment: 45 pages, including 16 figure