Background
Reflux monitoring using combined multichannel intraluminal impedance (MII) and pH-metry increases the sensitivity for identifying gastroesophageal reflux episodes. The likelihood of a ...positive symptom index (SI) for patients with reflux disease (gastroesophageal reflux disease GERD or nonerosive reflux disease NERD) receiving proton pump inhibitor (PPI) treatment has been used to select candidates for antireflux surgery. Little is known about the advantages of MII-pH monitoring compared with pH monitoring alone for evaluating GERD/NERD patients off PPI treatment considered as candidates for antireflux surgery or for assessing changes in MII-pH-detected reflux episodes after antireflux surgery. This study aimed to determine the additional value of MII over pH-metry alone for patients off PPI treatment before and after antireflux surgery.
Methods
For this study 12 patients (4 women and 8 men; mean age, 45 years; range, 27–74 years) were evaluated using ambulatory MII-pH monitoring before and 3 months after mesh-augmented hiatoplasty. Reflux events were identified by MII-pH (A) and pH-metry (B) as patients recorded symptoms on a data logger. For each symptom, a symptom index was calculated for reflux events identified by MII-pH and by pH-monitoring alone.
Results
Preoperatively, MII-pH monitoring identified 71.9 ± 8.4 reflux episodes, whereas pH monitoring identified only 51.0 ± 7.8 (
p
< 0.05). Postoperatively, MII-pH monitoring identified 35.5 ± 6.6 reflux episodes, whereas pH monitoring identified only 19.6 ± 4.7 (
p
< 0.05). The pre- and postoperative symptom index for MII-pH monitoring was higher than pH monitoring (preoperative 91.7% vs 25%,
p
= 0.006; postoperative 50% vs 16.7%,
p
= 0.012).
Conclusion
Combined MII-pH-metry improves the pre- and postoperative assessment of GERD patients off PPI and results in a higher symptom-reflux association.
— We report spectroscopic observations of meteors made from the FISTA aircraft on 1998 November 17 as a part of the Leonid multi‐instrument aircraft campaign. Low‐resolution spectra of 119 meteors of ...apparent visual magnitudes from +3 to −4, corresponding to meteoroid masses from 10−6 to 10−3 kg, were obtained. After analyzing a representative sample of the spectra and comparing them to the spectra of Perseid meteors from the Ondrejov archive, the following conclusions were reached: Leonid meteoroids are very loose and disintegrate easily in the atmosphere. This leads to much faster evaporation of volatile Na than of other elements, an effect which is not observed in the Perseid meteors. Relative bulk abundances of Mg, Fe, Ca, and Na in Leonid meteors are nearly CI‐chondritic within the uncertainty of the method (factor of 3). Smaller meteoroids tend to be poorer in Na, which is true also for Perseid meteors. Most meteoric vapor emissions could be reasonably well explained with the temperature of 4500 K. High‐temperature meteoric emissions (Ca+, Mg+) are present only in bright meteors. Leonid spectra are very rich in atmospheric emissions of O, N, and N2, even at high altitudes and in faint meteors. These emissions are therefore not connected with the meteor shock wave. Thermal continuum is also present in the spectra. Organic material was not revealed.
Since 2006, systematic double-station photographic observations of fireballs using all-sky cameras equipped with Zeiss Distagon “fisheye” objectives (
f
/3.5,
f
= 30 mm) with a 180° field of view ...have been carried out at two observatories, Gissar (GisAO) and Sanglokh (IAOS), of the Institute of Astrophysics of the Tajik Academy of Sciences. In the method of astrometric reduction of fireball photographs, the empirical formulae for converting the measured coordinates to horizontal celestial coordinates are used. These formulae contain 12 unknown constants to be determined by the least-squares method and the iteration method. Such an approach enables the determination of the coordinates of an object at any point of the celestial hemisphere with a precision close to the theoretical limit whose value is quite comparable with the measurement errors. In the photometric reduction, the dependence of the measured width of the diurnal star trails on their magnitudes was used. As a result of astrometric and photometric reduction of the double-station photographs of five fireballs, the data on atmospheric trajectories, the coordinates of radiants, orbits in interplanetary space, light curves, and photometric masses of meteoroids which produced fireballs were obtained, and the belonging of fireballs to the known meteor showers was determined as well.
A considerable depletion of sodium was observed in Geminid meteoroids. To explain this phenomenon, we developed a quantitative model of sodium loss from meteoroids due to solar heating. We found that ...sodium can be lost completely from Geminid meteoroids after several thousands of years when they are composed of grains with sizes up to ∼100 μm. The observed variations of sodium abundances in Geminid meteor spectra can be explained by differences in the grain sizes among these meteoroids. Sodium depletions are also to be expected for other meteoroid streams with perihelion distances smaller than ∼0.2 AU. In our model, the meteoroids were represented by spherical dust-balls of spherical grains with an interconnected pore space system. The grains have no porosity and contain usual minerals known from meteorites and IDP's, including small amount of Na-bearing minerals. We modeled the sequence of three consecutive processes for sodium loss in Geminid meteoroids: (i) solid-state diffusion of Na atoms from Na-bearing minerals to the surface of grains, (ii) thermal desorption from grain surfaces and (iii) diffusion through the pore system to the space. The unknown material parameters were approximated by terrestrial analogs; the solid-state diffusion of Na in the grains was approximated by the diffusion rates for albite and orthoclase.
Asteroids 3200 Phaethon and 196256 (2003 EH1) are connected with two major meteoroid streams, Geminids and Quadrantids, respectively. We have modeled the observed light curves and decelerations of ...Geminid and Quadrantid meteors and studied their spectra. In both cases, we have found typical bulk densities of about 2600 kg m−3, much larger than in cometary meteoroids. Sodium was partially lost from Geminids and Quadrantids due to solar heating. The Quadrantid material was therefore not hidden deep inside the parent body 1500 years ago, when the perihelion was low enough for sodium loss to occur.
The current gold standard in Barrett's esophagus monitoring consists of four-quadrant biopsies every 1-2 cm in accordance with the Seattle protocol. Adding brush cytology processed by digital image ...cytometry (DICM) may further increase the detection of patients with Barrett's esophagus who are at risk of neoplasia. The aim of the present study was to assess the additional diagnostic value and accuracy of DICM when added to the standard histological analysis in a cross-sectional multicenter study of patients with Barrett's esophagus in Switzerland.
One hundred sixty-four patients with Barrett's esophagus underwent 239 endoscopies with biopsy and brush cytology. DICM was carried out on 239 cytology specimens. Measures of the test accuracy of DICM (relative risk, sensitivity, specificity, likelihood ratios) were obtained by dichotomizing the histopathology results (high-grade dysplasia or adenocarcinoma vs. all others) and DICM results (aneuploidy/intermediate pattern vs. diploidy).
DICM revealed diploidy in 83% of 239 endoscopies, an intermediate pattern in 8.8%, and aneuploidy in 8.4%. An intermediate DICM result carried a relative risk (RR) of 12 and aneuploidy a RR of 27 for high-grade dysplasia/adenocarcinoma. Adding DICM to the standard biopsy protocol, a pathological cytometry result (aneuploid or intermediate) was found in 25 of 239 endoscopies (11%; 18 patients) with low-risk histology (no high-grade dysplasia or adenocarcinoma). During follow-up of 14 of these 18 patients, histological deterioration was seen in 3 (21%).
DICM from brush cytology may add important information to a standard biopsy protocol by identifying a subgroup of BE-patients with high-risk cellular abnormalities.
Health regulatory approval of the 1.5 μg/kg body weight dose of pegylated interferon (PEG‐I) alpha‐2b in combination with ribavirin for the treatment of chronic hepatitis C was based on a study using ...PEG‐I alpha‐2b at doses of only 0.5 and 1.5 μg/kg body weight (BW), in spite of the previously shown flat dose–response curve at doses of ≥1.0 μg/kg. Our aim was to compare PEG‐I alpha‐2b 1.0 μg/kg with 1.5 μg/kg, both in combination with ribavirin. Open‐label, randomized study in 227 patients with biopsy‐proven chronic hepatitis C (Metavir ≤F2), receiving oral ribavirin (400 mg, twice daily) in combination with subcutaneous PEG‐I alpha‐2b (1.0 or 1.5 μg/kg, once weekly) for 24 weeks (genotype 2 or 3), or 48 weeks (other genotypes), followed by a 24‐week drug‐free period. Virologic response rates did not differ between the two doses of PEG‐I alpha‐2b: in patients infected with hepatitis C virus (HCV) genotype 1 or 4 treated with PEG‐I 1.0 μg/kg BW, 38% (22/58) had a sustained virologic response compared with 39% (27/70) in the PEG‐I 1.5 μg/kg BW dose group (P = ns). The corresponding values in patients infected with HCV genotype 2 or 3 were 71% (39/55) and 81% (29/36) respectively (P = ns). Adverse events led to transient or permanent dose reductions in fewer patients in the 1.0 μg/kg BW dose group (48/113 patients; 42%) than in the 1.5 μg/kg BW dose group (63/106 patients; 59%, P = 0.015). Furthermore, 89% of patients treated for 24 weeks but only 58% of patients treated for 48 weeks (P < 0.001) tolerated the treatment without relevant dose reduction or premature termination. In combination with ribavirin, PEG‐I alpha‐2b 1.0 μg/kg was as effective as 1.5 μg/kg but was better tolerated in patients with chronic hepatitis C and up to moderate fibrosis.
Background—Exogenous cholecystokinin (CCK) inhibits antral motility and slows gastric emptying (GE) but the effect of endogenous CCK on the gastric motor mechanisms responsible for GE remains ...unclear. Methods—The effect of the CCK-A antagonist loxiglumide (LOX) on GE and motility was studied using magnetic resonance imaging in six healthy volunteers after ingestion of 500 ml Intralipid 10% (550 kcal). Subjects were studied in the supine position on two occasions during intravenous infusion of LOX (66 μmol/kg/h for 10 min followed by 22 μmol/kg/h) or placebo. GE was determined every 15 minutes using transaxial abdominal scans and motility was studied by means of 120 coronal scans, 1.2 seconds apart. For each coronal image the proximal and distal (antral) diameters were measured at a fixed point in the stomach to determine contraction frequency (ACF) and amplitude (AMP). Results—GE was faster during LOX infusion than placebo (t1/2 31 (22) versus 115 (67) minutes, p<0.03). There was little variation in the diameter of the proximal stomach with either LOX or placebo. In the distal stomach marked contractile activity was observed during LOX (ACF 2.9 (0.2) versus 1.5 (2.9) during placebo, p<0.01). AMP also increased during LOX compared with placebo (56 (22)% versus 27 (16)%, p<0.001). Conclusion—The increases in antral motility are likely to contribute to the acceleration of GE and suggest that CCK may regulate GE by acting on the distal stomach although an effect on the proximal stomach cannot be excluded.
Meteor Phenomena and Bodies Ceplecha, Zdenk; Borovicka, JirÍ; Elford, W Graham ...
Space science reviews,
01/1998, Volume:
84, Issue:
3-4
Journal Article
Peer reviewed
Meteoroids can be observed at collision with the Earth's atmosphere as meteors. Different methods of observing meteors are presented: besides the traditional counts of individual events, exact ...methods yield also data on the geometry of the atmospheric trajectory; on the dynamics and ablation of the body in the atmosphere; on radiation; on the spectral distribution of radiation; on ionization; on accompanying sounds; and also data on orbits. Theoretical models of meteoroid interaction with the atmosphere are given and applied to observational data. Attention is paid to radar observations; to spectroscopic observations; to experiments with artificial meteors and to different types of meteor sounds. The proposed composition and structure of meteoroids as well as their orbits link them to meteorites, asteroids and comets. Meteor streams can be observed as meteor showers and storms. The rate of influx of meteoroids of different sizes onto Earth is presented and potential hazards discussed.PUBLICATION ABSTRACT
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