Assessing outcomes for dysphonic patients

This study was designed to evaluate a disease-specific outcome measure for patients with selected voice disorders and to relate this instrument to a standardized quality of life measurement. In addition, the study attempts to document the degree of handicap for dysphonia patients globally, between different vocal pathologies, and in comparison to other chronic diseases. In this prospective, observational study, 260 adult patients evaluated for alterations of voice completed a general quality of life measure (the Medical Outcomes Trust Short Form 36-Item[SF-36]) and a voice-specific instrument (Voice Handicap Index [VHI]) pretreatment.

The highest correlation was between the social functioning score of the SF-36and the total score of the VHI and the physical, emotional, and functional subscales (p < 0.001) of the VHI. Significant correlation was also obtained for the SF-36 domains mental health (p < 0.01), general health (p < 0.01), and role functioning emotional (p < 0.017) with the three VHI domains and the total VHI score. Patients had significantly lower scores than the general U.S. population in five of the eight domains of SF-36. Patients with vocal fold paralysis had the highest level of pretreatment disability as measured on both the VHI and SF-36 among voice patients. The patients with dysphonia had a lower level of physical functioning than the patients with chronic sinusitis (p < 0.01), reflecting a greater handicap. In addition, the dysphonia group had lower levels of social functioning than the angina (p < 0.01) and sciatica (p < 0.01) groups and a lower score for mental health than the angina group (p < 0.01).

The SF-36 correlates with the VHI in the domains of social functioning,mental health, and role functioning emotional. The baseline handicap for voice disorders represents a significant disability even in comparison to conditions such as angina pectoris, sciatica, and chronic sinusitis.     

Frequency of voice problems among teachers and other occupations

This study describes the frequency of reporting vocal problems among a random sample of elementary and high school teachers (n = 554) compared to individuals working in other occupations (n = 220). Teachers were more likely to define themselves as ever having a voice problem (32% versus. 1 %, p < .05); having a tired, weak, or effortful voice (p < .05 each); and having a higher frequency of symptoms of physical discomfort with speaking (p < .05). They also were more likely to perceive that their voice problem negatively affected current job performance (p < .05) and limited options regarding change in work (p < .05). About 20% of teachers but only 4% of nonteachers had missed work due to their voice. These findings suggest that teachers are at highrisk for disability from voice disorders and that this health problem may have significant work-related and economic effects.     

The ChatterVox™ Portable Voice Amplifier: A Means to Vibration Dose Reduction?

By speaking loudly for extended periods, teachers are vulnerable to laryngeal and voice changes associated with vocal fold “vibration overdose.” Voice clinicians frequently recommend voice amplification ostensibly designed to reduce vibration dose and improve voice. However, there are few data regarding the degree of vocal loudness attenuation achieved by specific amplification devices. The purpose of this investigation was to examine the effectiveness of the ChatterVox™ Portable Voice Amplification System (Siemens Hearing Instruments) for reducing the sound pressure level (SPL) of a speaker's voice during a simulated classroom lecture. Ten participants were instructed to continuously read one of two phonetically balanced passages while amplified and unamplified. Voice intensity measurements were obtained at three inches from the mouth (i.e., mouth level) and at the back of a classroom in both amplified and unamplified conditions. When amplified with the ChatterVox™, speakers experienced an average decrease in vocal intensity at mouth-level of 6.03 dB SPL (p < 0.002). Furthermore, an average increase of 2.55 dB SPL (p < 0.038) at the back of the classroom was observed. Collectively, these results indicate that the ChatterVox™ amplification device reduced the speaker's vocal intensity level at the microphone, while it augmented the voice heard at the back of the classroom. By inference, this degree of vocal attenuation at mouth level should contribute to a desirable reduction in vibration dose, thus lowering the risk of vibration overdose.     

Morphometry in temporal lobe epilepsy

We demonstrate a method for quantitating changes in volume and morphology of the temporal lobe in epilepsy. The temporal lobes of 10 neurologically normal subjects and six subjects with well defined left-sided mesial temporal epilepsy were studied. From high resolution T₁-weighted magnetic resonance images, the grey and white matter were manually segmented over a predetermined extent. The volumes of the grey and white matter were determined. Using the segmented images, the grey matter/CSF surface and the white matter/grey matter surface were reconstructed, allowing estimates of the surface area and calculation of indices of curvature for the two surfaces. The index of curvature was calculated for each vertex of a polygonal mesh that was fitted to the surfaces. An index of grey matter thickness (grey matter volume/white matter surface area) was also calculated. There was a significant bilateral decrease in the total volume (p < .01), grey matter volume (p < .001) and grey matter thickness index (p < .05) in epileptic subjects. In addition, there was a bilateral decrease in white matter surface area (p < .05) and a small left-sided decrease in white matter volume (p < .05) in epileptic subjects. The average distributions of indices of curvature for both surfaces differed significantly (p < .05) between normal and epileptic subjects. In the grey matter/CSF surface of normal subjects, a large peak corresponding to surface concavity was present. The amplitude of this peak was significantly lower in epileptic subjects (p < .05 for the right hemisphere; p < .001 for the left hemisphere).     

Incommensurability in an exactly-soluble quantal and classical model for a kicked rotator

The Hamiltonian H = 2πp + V(θ) Σ^∞_−∞ δ(t − n)(0 θ < 2π) is solved exactly, classically and quantally; the so lutions depend strongly on . There is no classical chaos and the phase cylinder p, θ is filled with invariant curves, which are finite loops around the cylinder if is sufficiently irrational and are translates of the infinitely long p axis if is rational. Quantal quasi-energy states correspond exactly to these invariant curves: localized in p and extended in θ if is sufficiently irrational, and extended in p and localized in θ if is rational. For a classical or quantal initial pure-momentum state, the energy at time t = n grows as n² if is rational (resonance) and remains bounded if is sufficiently irrational (non-resonance). If is very nearly rational (marginal resonance), the energy may grow as n^λ where λ is expressed in terms of exponents describing the irrationality of and the continuity class of V(θ). If the value of is uncertain, ensemble-averaging over shows that the energy grows ultimately as n, i.e. diffusively, as though under random impulses.     

π-electroproduction on hydrogen near threshold at four-momentum transfers of 0.2, 0.4 and 0.6 GeV

The reaction e + p → e + π⁰ + p was measured near the one pion threshold, detecting the final electron and proton in coincidence for values of q² = 0.2, 0.4 and 0.6 GeV². The slope of the cross section at threshold is determined. The data are compared with those of the e + p → e + π⁺ + n reaction, measured simultaneously, and with the results of pseudovector Born approximation and with dispersion theoretical calculations.     

Effects of meson exchange currents on pion absorption

The effect of the π exchange current on the pion absorption process π⁺ + d → p + p has been investigated. The absorption cross section is significantly enhanced particularly in the energy region above the 33 resonance.     

Search for up-down quark mass differences via isospin symmetry breaking

We performed a series of experiments employing the two pion production reactions p + d → ³He + π⁰ and p + d → ³H + π⁺. The two isopin related reactions differ by a Clebsch Gordan coefficient of 2. We searched for deviations in this ratio in complete angular distributions in the range of the Δ excitation as well as in the vicinity of the η production threshold.     

Simultaneous measurements of the p+d→(A=3)+π reactions

A stack of annular detectors made of high-purity germanium was used to measure simultaneously pd → ³H π⁺ and pd → ³He π⁰ differential cross sections at beam momenta of 750 MeV/c, 800 MeV/c, and 850 MeV/c over a large angular range. The extracted total cross sections for the pd → ³He π⁰ reactions bridge a gap between near threshold data and those in the resonance region. The ratio of the cross sections for the two reaction channels taken at the same η=p^cm_π/m_π yields 2.11±0.08 indicating that a deviation from isospin symmetry is very small.     

Experimental observation of a copious yield of electrons with small transverse momenta in pp collisions at high energies

Inclusive electron and positron emission have been observed for θ_cm = 30° and S = 2800 GeV² at the CERN Intersecting Storage Rings (ISR). Over the transverse momentum interval 0.2 GeV/c < p_T < 1.5 GeV/c, electrons and positrons, which are equal in number within the experimental accuracies, appear to grow with respect to other particles (pions) approximately like 1/p_T. We are unable to explain their number and p_T-dependence in terms of “conventional” mechanisms.     

Absorption cross sections for antiprotons on carbon, aluminum and copper at 485 and 597 MeV/c

Absorption cross sections for antiprotons on C, Al and Cu have been measured by a transmission method at 485 and 597 MeV/c. Nuclei are shown to be black to antiprotons at these momenta. Using the available data up to 280 GeV/c, the momentum dependence of the absorption cross sections is investigated. Empirically, a simple expression σ_abs = γ(p/p₀)^−β, with β and γ constants and p₀ = 1 GeV/c, gives a good account of the data in a remarkably wide momentum range, 0.5–280 GeV/c.     

Magnetic moment of the Δ (1232) resonance

The reaction γp → π^°γ′p has been measured with the TAPS BaF₂ calorimeter at the Mainz Microtron accelerator facility MAMI for energies between √2 = 1221–1331 MeV. Cross sections differential in angle and energy have been determined for the photon γ′ in three bins of the excitation energy. This reaction channel provides access to the magnetic dipole moment of the Δ⁺(1232) resonance and, for the first time, a value of μ_Δ+ = (2.7^+1.0_−1.3(stat) ± 1.5(syst) ± (theor)) π_N has been extracted.     

Quantitative estimation of brain white matter abnormalities in elderly subjects using magnetic resonance imaging

Twenty-five elderly subjects were examined with brain magnetic resonance imaging (MRI). The subjects were divided into two groups: those with Mini-Mental State Examination (MMSE) scores above 25, and those subjects with MMSE scores between 18 and 24. The degree of white matter abnormalities (WMA) (expressed as relative volumes) as well as the presence of cerebrovascular risk factors were evaluated in the two groups. We found that a) subjects with low MMSE scores had significantly larger relative volumes of WMA than the subjects with higher scores, b) a significant correlation (r_s = 0.53, p < 0.009) between MMSE scores and the relative volume of WMA was also established, and c) a weak significant correlation (r_s = −0.51, p < 0.05) between arterial blood pressure and WMA was found in the subjects with high MMSE scores. Besides these findings no other correlations between the presence of cerebrovascular risk factors and WMA were found in any of the groups.     

The reactions pp→pΛK and pp→pΣK near their thresholds

The reactions pp→pΛK⁺ and pp→pΣ⁰K⁺ are studied near their thresholds. The strangeness production process is described by the π- and K exchange mechanisms. Effects from the final state interaction in the hyperon-nucleon system are taken into account rigorously. The Λ production turns out to be dominated by K exchange whereas K- as well as π exchange play an important role for the Σ⁰ case. It is shown that the experimentally observed strong suppression of Σ⁰ production compared to Λ production at the same excess energy can be explained by a destructive interference between π and K exchange in the reaction pp→pΣ⁰K⁺. Implications of such an interference on the reaction pp→nΣ⁺K⁺ are pointed out.     

Strangeness production in proton collisions close to threshold at COSY-TOF

The K-meson production in elementary proton induced reactions is studied exclusively at the external COSY beam using the time-of-flight spectrometer TOF. The complete measurement of all primary and decay particle tracks allows the extraction of total and differential cross sections as well as Dalitz plots and invariant mass spectra of the subsystems for the channels pp → K⁺ Δp, K⁰Σ⁺p, K⁺Σ⁰p and K⁺Σ⁺n. For all channels the full phase space is covered from the reaction threshold up to the COSY-limit of about 3.5 GeV/c. Especially the analysis of the Dalitz plots of the channel pp→K⁺Δp show a strong influence of N₋^* resonances.     

Scaling limit of deeply virtual compton scattering

I outline a perturbative QCD approach to the analysis of the deeply virtual Compton scattering process γ^*p → γp′ in the limit of vanishing momentum transfer t = (p′ − p)². The DVCS amplitude in this limit exhibits a scaling behavior described by two-argument distributions F(x,y) which specify the fractions of the initial momentum p and the momentum transfer r ≡ p′ − p carried by the constituents of the nucleon. The kernel R(x,y;ξ,η) governing the evolution of the non-forward distributions F(x,y) has a remarkable property: it produces the GLAPD evolution kernel P(x/ξ) when integrated over y and reduces to the Brodsky-Lepage evolution kernel V(y,η) after the x-integration. This property is used to construct the solution of the one-loop evolution equation for the flavor non-singlet part of the non-forward quark distribution.     

Magnetic resonance imaging with superparamagnetic iron oxide particles for the detection of myocardial reperfusion

The effect of superparamagnetic iron oxide particles on magnetic resonance myocardial signal intensity was examined in order to define the ability of this agent to identify normal, ischemic, and reperfused myocardium. Data were obtained from 6 normal rats (group 1) and from 6 heterotopic isogenic rat heart transplants (group 2) at 4.7 T with a multislice spin-echo sequence. Images were acquired in (a) normal rats before and after the infusion of 36 μmol Fe/kg of AMI-25 (group 1) and (b) rat heart transplants during control, global myocardial ischemia (before and after the injection of 72 μmol Fe/kg of AMI-25), and following reperfusion (group 2). Myocardial signal intensity decreased by 36 ± 4%, p < 0.001, following contrast infusion in normal hearts (group 1). The intensity remained constant in the rat heart transplants (group 2) during coronary occlusion, both before and after the infusion of AMI-25 and decreased by 61 ± 7%, p < 0.001, upon reperfusion. The larger effect of AMI-25 in reperfused as compared to normal myocardium suggests the presence of ischemia-induced hyperemia. There was no significant difference (analysis of variance) among intensities from different myocardial regions in either group at any stage of the experiment. We conclude that the use of AMI-25 permits identification of normal, ischemic, and reperfused myocardium and may therefore be helpful for the early detection of reperfusion following thrombolytic therapy for acute myocardial infarction.     

On- and off-resonance spin-lock MR imaging of normal human brain at 0.1 T: possibilities to modify image contrast

The aim of the present investigation was to determine spin lock (SL) relaxation parameters for the normal brain tissues and thus, to provide basis for optimizing the imaging contrast at 0.1 T. 68 healthy volunteers were included. On-resonance spin lock relaxation time (T_1ρ) and off-resonance spin lock relaxation parameters (T_1ρ^off, M_e/M_o), MT parameters (T_1sat, M_s/M_o), and T₁, T₂ were determined for the cortical gray matter, and for the frontal and parietal white matters. The T_1ρ for the frontal and parietal white matters ranged from 110 to 133 ms and from 122 to 155 ms with locking field strengths from 50 μT to 250 μT, respectively. Accordingly, the values for the gray matter ranged from 127 to 155 ms. With a locking field strength of 50 μT, T_1ρ^off for the frontal and parietal white matters were from 114 to 217 ms and from 126 to 219 ms, and for the gray matter from 136 to 267 ms with the angle between the effective magnetic field (B_eff) and the z-axis (θ) ranging from 60° to 15°, respectively. The T_1ρ of the white and gray matters increased significantly with increasing locking field amplitude (p < 0.001). The T_1ρ^off decreased significantly with increasing θ (p < 0.001). T_1ρ and T_1ρ^off with θ ≥ 30° were statistically significantly shorter in the frontal than in the parietal white matters (p < 0.05). The duration, amplitude and θ of the locking pulse provide additional parameters to optimize contrast in brain SL imaging.     

Assessment of mitral regurgitation by magnetic resonance imaging

To evaluate the potential of magnetic resonance imaging (MRI) in detection and quantification of mitral regurgitation, 26 pts. with echocardiographically or angiographically documented mitral regurgitation were examined using a 0.5 Tesla superconducting magnet. In each patient a multislice-multiphase study in a sagittal-coronal double angulated projection (four-chamber view equivalent) was performed to assess left and right ventricular volumes, ejection fraction and regurgitant fraction. Additionally a blood flow sensitive cine-study (fast field echo: FFE) was done to visualize direction and area of regurgitant jet. MRI data were compared with quantitative and qualitative assessment of mitral regurgitation by angiography, 2D echocardiography, Doppler sonography and color flow mapping. Using the FFE mode MRI was able to detect the regurgitant jet as a typical signal loss within the left atrium in all patients. The ratio of regurgitant jet area/left atrium area as determined by MRI showed a correlation with a comparable ratio from color Doppler sonography of R = 0.87 (p < 0.001). There was also good agreement in semiquantitative grading of mitral regurgitation between MRI and angiography (R = 0.77, p < 0.001). The determination of left and right ventricular stroke volume allowed the calculation of the regurgitant fraction, which showed a correlation with invasively determined regurgitation fraction of R = 0.84 (p < 0.001). These data provide additional information that MRI may be useful as a noninvasive technique to detect and quantify mitral regurgitation.