Esophageal motility in eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is characterized by eosinophilic infiltration of the esophagus and is a potential cause of dysphagia and food impaction, most commonly affecting young men. Esophageal manometry findings vary from normal motility to aperistalsis, simultaneous contractions, diffuse esophageal spasm, nutcracker esophagus or hypotonic lower esophageal sphincter (LES). It remains unclear whether esophageal dysmotility plays a significant role in the clinical symptoms of EoE. AIM: Our aim is to review the pathogenesis, diagnosis, and effect of treatment on esophageal dysmotility in EoE. METHODS: A literature search utilizing the PubMed database was performed using keywords: eosinophilic esophagitis, esophageal dysmotility, motility, manometry, impedance planimetry, barium esophagogram, endoscopic ultrasound, and dysphagia. RESULTS: Fifteen studies, totaling 387 patients with eosinophilic esophagitis were identified as keeping in accordance with the aim of this study and included in this review. The occurrence of abnormal esophageal manometry was reported to be between 4 and 87% among patients with EoE. Esophageal motility studies have shown reduced distensibility, abnormal peristalsis, and hypotonicity of the LES in patients with EoE, which may also mimic other esophageal motility disorders such as achalasia or nutcracker esophagus. Studies have shown conflicting results regarding the presence of esophageal dysmotility and symptoms with some reports suggesting a higher rate of food impaction, while others report no correlation between motor function and dysphagia. CONCLUSIONS: Motility dysfunction of the esophagus in EoE has not been well reported in the literature and studies have reported conflicting evidence regarding the clinical significance of dysmotility seen in EoE. The correlation between esophageal dysmotility and symptoms of EoE remains unclear. Larger studies are needed to investigate the incidence of esophageal dysmotility, clinical implications, and effect of treatment on patients with EoE.

Auger-mediated sticking of positrons to surfaces: evidence for a single-step transition from a scattering state to a surface image potential bound state.

We present the observation of an efficient mechanism for positron sticking to surfaces termed here Auger-mediated sticking. In this process the energy associated with the positrons transition from an unbound scattering state to a bound image potential state is coupled to a valence electron which can then have sufficient energy to leave the surface. Compelling evidence for this mechanism is found in a narrow secondary electron peak observed at incident positron kinetic energies well below the electron work function.

A multi-stop time-of-flight spectrometer for the measurement of positron annihilation-induced electrons in coincidence with the Doppler-shifted annihilation gamma photon.

In this study, we describe an advanced multi-functional, variable-energy positron beam system capable of measuring the energies of multiple "positron-induced" electrons in coincidence with the Doppler-shifted gamma photon resulting from the annihilation of the correlated positron. The measurements were carried out using the unique characteristics of the digital time-of-flight spectrometer and the gamma spectrometer available with the advanced positron beam system. These measurements have resulted in (i) the first digital time-of-flight spectrum of positron annihilation-induced Auger electrons generated using coincident signals from a high-purity Ge detector and a micro-channel plate, (ii) a two-dimensional array of the energy of Doppler-broadened annihilation gamma and the time-of-flight of positron-annihilation induced Auger electrons/secondary electrons measured in coincidence with the annihilation gamma photon, and (iii) the time-of-flight spectra of multiple secondary electrons ejected from a bilayer graphene surface as a result of the impact and/or annihilation of positrons. The novelty of the gamma-electron coincidence spectroscopy has been demonstrated by extracting the Doppler-broadened spectrum of gamma photons emitted due to the annihilation of positrons exclusively with 1s electrons of carbon. The width of the extracted Doppler-broadened gamma spectrum has been found to be consistent with the expected broadening of the annihilation gamma spectrum due to the momentum of the 1s electrons in carbon.

Auger electron emission initiated by the creation of valence-band holes in graphene by positron annihilation.

Auger processes involving the filling of holes in the valence band are thought to make important contributions to the low-energy photoelectron and secondary electron spectrum from many solids. However, measurements of the energy spectrum and the efficiency with which electrons are emitted in this process remain elusive due to a large unrelated background resulting from primary beam-induced secondary electrons. Here, we report the direct measurement of the energy spectra of electrons emitted from single layer graphene as a result of the decay of deep holes in the valence band. These measurements were made possible by eliminating competing backgrounds by employing low-energy positrons (<1.25 eV) to create valence-band holes by annihilation. Our experimental results, supported by theoretical calculations, indicate that between 80 and 100% of the deep valence-band holes in graphene are filled via an Auger transition.

Time of flight spectrometer for background-free positron annihilation induced Auger electron spectroscopy.

We describe a novel spectrometer designed for positron annihilation induced Auger electron spectroscopy employing a time-of-flight spectrometer. The spectrometer's new configuration enables us to implant monoenergetic positrons with kinetic energies as low as 1.5 eV on the sample while simultaneously allowing for the detection of electrons emitted from the sample surface at kinetic energies ranging from ∼500 eV to 0 eV. The spectrometer's unique characteristics made it possible to perform (a) first experiments demonstrating the direct transition of a positron from an unbound scattering state to a bound surface state and (b) the first experiments demonstrating that Auger electron spectra can be obtained down to 0 eV without the beam induced secondary electron background obscuring the low energy part of the spectra. Data are presented which show alternative means of estimating positron surface state binding energy and background-free Auger spectra.

Ahomocysteinemia in molybdenum cofactor deficiency.

We report an infant with molybdenum cofactor deficiency (MCD) and a unique clinical presentation of hemiplegia, hypotonia, dystonia, and bilateral basal ganglia changes. Biochemistry revealed absent serum homocysteine, low concentrations of plasma cystine, high levels of urinary S-sulfocysteine and sulfite, and high levels of oxypurines in serum and urine. The depletion of cysteine and cystine through reaction with sulfite suggests that other thiols and thiol-dependent proteins may be similarly depleted. Ahomocysteinemia may be a clue to the mechanism of cytotoxicity in MCD.

Ankyloblepharon filiforme adnatum.

We treated 4 infants with ankyloblepharon filiforme adnatum (AFA), an uncommon anomaly in which the apposing eyelid margins are connected by abnormal tissue strands. One infant had AFA alone, one had Hay-Wells syndrome, characterized by ectodermal dysplasia, and the other 2 had chromosome abnormalities, trisomy 18, and complex chromosome rearrangement, with visceral malformations. Despite heterogeneity and phenotypic variability, these developmental abnormalities shared (1) involvement of tissues growing in apposition and (2) temporal overlap of their occurrence. This suggests a common defect in the mechanism(s) that regulate tissue fusion at multiple sites during development.

Complex microphthalmos.

Forty patients were diagnosed as having complex microphthalmos on the basis of a malformed globe with a total axial length measurement at least 2 SDs below the mean for age-similar controls. Three had anterior segment dysgenesis; 4, congenital lens abnormalities; 14, chorioretinal colobomas; 12, persistent hyperplastic primary vitreous; 4, retinal dysplasia; and 3, complex malformations due to ipsilateral facial malformations. Measurements of total axial length indicated that complex microphthalmos was congenital and that postnatal growth of the malformed eye was similar to that of normal eyes. In most patients the anterior segment length was normal, while in all patients the posterior segment length was at least 2 SDs below the mean. Corneal diameter correlated significantly with total axial length (r2 = .57) and decreased linearly as total axial length decreased. In most patients in whom measurements were obtained, the lens and corneal power were increased, thereby compensating for decreased total axial length. We propose that inadequate production of secondary vitreous is the cause of the microphthalmos, given that the posterior segment was disproportionately reduced in size and the secondary vitreous is its predominant component. Evidence that each of the various ocular malformations can influence the production of secondary vitreous is presented.

Simple microphthalmos.

Simple microphthalmos was diagnosed in 22 patients on the basis of a normal-appearing eye and a total axial length at least 2 SDs below the mean for age. Anterior segment length was normal in most patients while posterior segment length was at least 2 SDs below the mean in all patients, indicating that disproportionate reduction in posterior segment length accounted for the microphthalmos. The normal values for total axial length, anterior segment length, and posterior segment length were determined from the analysis of axial length measurements obtained from age-similar controls. Ten patients had isolated microphthalmos. One of them was diagnosed as having nanophthalmos on the basis of microcornea, total axial length less than 18 mm, and absence of systemic disease. Twelve patients had associated systemic disorders, such as fetal alcohol syndrome, myotonic dystrophy, and achondroplasia, which implicated decreased size of the optic cup, altered vitreous proteoglycans, low intraocular pressure, and abnormal release of growth factors in the pathogenesis of microphthalmos.

Parental leave: comparing children's hospitals with Fortune 500 companies.

OBJECTIVE: To identify parental leave policies and availability of support systems for new parents employed by children's hospitals and compare these benefits with those offered by Fortune 500 companies. DESIGN: Telephone or facsimile survey of all (n=118) children's hospitals and pediatric medical centers in the National Association of Children's Hospitals and Related Institutions 1995 Directory of Members, and 118 geographically matched Fortune 500 companies. Policies for maternity and paternity leave, adoption benefits, and support services for new parents were compared. RESULTS: Ninety-four children's hospitals (80%) and 82 Fortune 500 companies (69%) responded to the survey. No difference in duration of maternity (P>.30) or paternity (P=.12) leave was found. Sixty-two companies (77%) classified maternity leave as short-term disability while 47 hospitals (50%) classified it as sick time (P<.005). Classifying maternity leave as short-term disability generally gives better benefits to employees with short duration of service, whereas classifying maternity leave as sick time usually favors employees with longer employment. Companies provided more financial support for adoption expenses (P<.05), but there was no difference in duration of paid or unpaid leave for adoption (P=.14). Hospitals provided more on-site day care (69% vs 42%; P<.001) and better support systems for breast-feeding mothers (49% vs 24%; P<.002). CONCLUSIONS: Children's hospitals do not offer better parental leave benefits than Fortune 500 companies; however, they offer better support systems for parents returning to work after the birth of a child.

Adrenal suppression after corticosteroid injection of periocular hemangiomas.

Two infants with symptomatic periocular hemangiomas received 1-ml intralesional injections of a 50:50 mixture of triamcinolone acetonide (40 mg/ml) and betamethasone (8 mg/ml). Both developed adrenal suppression as evidenced by the immediate depression of their serum cortisol and adrenocorticotrophic hormone levels. One patient remained adrenal suppressed for five months and, concurrently, her growth rate and weight dropped from normal to below the fifth percentile. Adrenal suppression should be added to the growing list of complications caused by the corticosteroid injection of periocular hemangiomas.

Unilateral high myopia: optical components, associated factors, and visual outcomes.

AIM: To elucidate the optical basis for unilateral high myopia and to identify the factors associated with its development. METHODS: Medical records of 48 children (aged 4 months to 17 years; mean age 6.8 years) with unilateral high myopia (5 dioptres or more) seen consecutively by the author during a 15 year period were reviewed. 45 (94%) of the 48 patients had unilateral axial myopia. RESULTS: The mean refractive difference between paired eyes was 9.4 (SD 3.6) dioptres and the more myopic eye was on average 3.3 (1.8) mm longer than the less myopic eye. All but three of the patients had an ocular disorder associated with reduced acuity, central nervous system abnormality, or family history of high myopia. CONCLUSION: Clinical conditions associated with unilateral high myopia can be identified in the majority of patients and often account for the associated visual impairment.

Development of the spatio-chromatic visual evoked potential (VEP): a longitudinal study.

Most prior visual evoked potential (VEP) research on the development of color vision has employed pattern-reversing stimuli that are not optimal for producing chromatic responses. We measured infant VEPs using low spatial frequency, onset-offset stimuli, modulated along the three axes of a cone-based color space (Derrington et al. [J. Physiol 1984;357, 241-265.]). Three color-normal infants were tested in a longitudinal design over the first postnatal year. One red/green color-deficient infant was also tested at 197 days. We found that VEP responses to S-axis (tritan) stimuli have their initial onset later than responses to red/green (L-M) or achromatic stimuli, and that developmental changes in VEP waveforms are more complex and longer lasting for chromatic than for achromatic stimuli. Possible mechanisms underlying these changes are discussed.

The swollen and droopy eyelid. Signs of systemic disease.

Swollen and droopy eyelids are obvious ocular findings, unlike many ocular conditions that require the use of special equipment to observe. Neither of these findings is a specific diagnosis but rather each is evidence of localized disease and often is a sign of underlying systemic disorder. Therefore, it is important for the clinician evaluating the child with a swollen or droopy lid to have a working knowledge of these diagnostic possibilities. In this article the author presents the various causes of the swollen and droopy eyelid, focus on the most relevant clinical characteristics, and emphasize systemic associations.

Blue cone monochromatism.

Blue cone monochromatism (BCM) is a subtype of achromatopsia in which the blue cone mechanism predominates. Each of the four patients in this study had BCM proven by their having peak spectral sensitivities in the blue region of the visible spectrum (near 440 nm). Clinically, the diagnosis was suspected because of x-linked inheritance, the presence of acuities better than 20/200 in two patients and myopia ranging from -1.75 to -15.00 diopters in three patients. Congenital nystagmus was the presenting sign in three of the four patients. Examination of the fundi was uniformly normal. The distinctive spectral properties of BCM were demonstrated by the American Optical H-R-R and the Panel D-15 tests. All affected patients correctly identified three of the four blue-yellow plates and a variable number of the red-green plates in the American Optical H-R-R test. The study patients consistently made errors oriented along the protan and deutan axes but they made none along the tritan axis. The authors conclude that the results of these two color discrimination tests are useful in diagnosing BCM.

Neuroretinitis in childhood.

We report the clinical features and results of laboratory testing of seven children with neuroretinitis, diagnosed on the basis of reduced visual acuity, relative afferent pupillary defect, and distinctive appearance of the fundi. Disc swelling was segmental in five patients with unilateral disease and diffuse in two patients with bilateral disease. Retinal infiltrates were transiently present in two patients. Swelling of the optic disc and peripapillary retina, along with the inflammatory vitritis resolved by 2 to 6 weeks but macular exudates persisted for 3 to 12 months. Two patients developed optic atrophy with permanent visual loss and two patients had visual acuity reduction detected only under low contrast conditions. Cat-scratch disease was implicated as the cause of the neuroretinitis in two patients; the etiology of the remaining cases was not established.

Primary and secondary orbital teratomas.

Two patients with primary teratomas of the orbit and a third patient with a teratoma invading the orbit from the maxillary sinus are presented. The clinical presentation of each patient was spectacular. In the primary teratomas, the globe was displaced out of the orbit by the attached tumor, causing extreme proptosis. Computed tomography was virtually diagnostic, showing a variegated orbital mass with solid and cystic components. Histologic examination showed multiple tissues derived from two or three germinal layers. The surgical removal of the tumors and reasons for the poor visual outcome are discussed. The appearance of teratomas in the orbit and other cephalic structures appears to arise from the survival and proliferation of germ cells deposited there during embryogenesis.