PubMed Health⌕ Search

Biomedical subjects

J E Arnold

Publications and source records attributed to J E Arnold.

At least 19 recordsLinked to original sources
PubMed2001

Pediatric otolaryngologists' knowledge and understanding of genetic testing for deafness.

OBJECTIVE: To assess the level of a cohort of pediatric otolaryngologists' knowledge and understanding of genetics and genetic testing for deafness and hard of hearing (D/HOH). METHODS: A questionnaire was designed to assess the level of knowledge and understanding of the genetic basis and genetic testing for deafness among a cohort of pediatric otolaryngologists. Three hundred questionnaires were made available to attendees of the 14th (1999) Annual Meeting of the American Society of Pediatric Otolaryngology, Palm Desert, Calif. A series of questions asked to gauge the respondent's level of knowledge of genetics and hearing impairment addressed estimating recurrence risks for deaf and normal-hearing parents and the likelihood of detecting a mutation in connexin 26 in specific clinical scenarios. RESULTS: A total of 28 questionnaires were completed and returned. All respondents reported that they regularly saw patients for D/HOH. Almost half commonly refer these patients for genetic testing and counseling. Seventeen (71%) of 24 otolaryngologists stated they offered genetic testing in all situations, while 6 offered counseling only at parental request or to address recurrence risk issues. One otolaryngologist offered genetic testing if there was a deaf sibling. Twelve (67%) of 18 offered pretest counseling, which was most frequently provided by a genetic counselor. Although 3 (19%) of 16 otolaryngologists provided the counseling themselves, 2 (13%) reported that they and a genetic counselor provided the counseling. While 24 (89%) of the 27 correctly stated that nonsyndromic D/HOH is usually autosomal recessive, recurrence risks were incorrectly estimated in several examples. CONCLUSIONS: While the surveyed pediatric otolaryngologists have a good knowledge of genetics and genetic testing for D/HOH, recurrence risks were often inaccurate. Since D/HOH testing is clinically available, it is imperative that physicians are educated about genetics and genetic testing and are able to communicate this to their patients and their patients' families.

Child↗
PubMed2001

Bioelectronic options for a totally implantable hearing device for partial and total hearing loss.

A semi-implantable electromagnetic hearing device (SIMEHD) for sensorineural hearing loss has been developed and tested in animals and limited clinical trial. The authors' electromagnetic transducer, which is the driver of the SIMEHD, when used in reverse mode is applicable to the fabrication of a bioelectronic microphone. Instead of being a driver, it transforms the sound-activated eardrum-ossicular vibration into an electric signal through the NdFeBo magnet implanted on the head of the malleus, interacting in a contactless manner with the electromagnetic coil.

Acoustics↗
PubMed2000

The rapid use of gender information: evidence of the time course of pronoun resolution from eyetracking.

Eye movements of listeners were monitored to investigate how gender information and accessibility influence the initial processes of pronoun interpretation. Previous studies on this issue have produced mixed results, and several studies have concluded that gender cues are not automatically used during the early processes of pronoun interpretation (e.g. Garnham, A., Oakhill, J. & Cruttenden, H. (1992). The role of implicit causality and gender cue in the interpretation of pronouns. Language and Cognitive Processes, 73 (4), 231-255; Greene, S. B., McKoon, G. & Ratcliff, R. (1992). Pronoun resolution and discourse models. Journal of Experimental Psychology: Learning, Memory, and Cognition, 182, 266-283). In the two experiments presented here, participants viewed a picture with two familiar cartoon characters of either same or different gender. They listened to a text describing the picture, in which a pronoun referred to either the first, more accessible, character, or the second. (For example, Donald is bringing some mail to ¿Mickey/Minnie¿ while a violent storm is beginning. He's carrying an umbrellaellipsis.) The results of both experiments show rapid use of both gender and accessibility at approximately 200 ms after the pronoun offset.

Cues↗
PubMed2000

The concomitant effects of phrase length and informational content in sentence comprehension.

Recent evidence suggests that phrase length plays a crucial role in modification ambiguities. Using a self-paced reading task, we extended these results by examining the additional pragmatic effects that length manipulations may exert. The results demonstrate that length not only modulates modification preferences directly, but that it also necessarily changes the informational content of a sentence, which itself affects modification preferences. Our findings suggest that the same length manipulation affects multiple sources of constraints, both structural and pragmatic, which can each exert differing effects on processing.

Adult↗
PubMed2000

Epiglottic hypoplasia associated with lacrimo-auriculo-dental-digital syndrome.

We present a case of a young boy with clinical manifestations of lacrimo-auriculo-dental-digital syndrome (LADD) with the additional finding of a hypoplastic epiglottis that caused airway obstruction at birth. We also reviewed the 30 cases of LADD that have been reported since 1967. It is a rare syndrome that includes lacrimal system, aural, digital, and dental anomalies. Our patient has lacrimal duct obstruction, deficient tissue in the inferior portion of the ear pinnae, and a hypoplastic epiglottis with collapse of the supraglottic tissue. Many findings of LADD are recognizable at birth. The clinical spectrum has widened with more case reports. Our patient adds a life-threatening airway abnormality, a hypoplastic epiglottis, to the clinical spectrum of LADD.

Abnormalities, Multiple↗
PubMed1999

Ubiquitin gene expression and ubiquitin conjugation in chicken muscle do not reflect differences in growth rate between broiler and layer birds.

Previous work has shown that chicken strains selected for growth (broilers) degrade muscle proteins less rapidly than those selected for egg laying. They also have decreased calpain and increased calpastatin content in breast muscle. This study aimed to test the hypothesis that these differences correlate with changes in the ATP- and ubiquitin-dependent proteolytic system. Chickens of a broiler strain (Ross 1) and a layer strain (ISABrown) were reared to the age of 4 wk under identical conditions with ad libitum access to feed and water. Mean fractional growth rates were 10.4%/d for broilers and 7.4%/d for layers. Feed intake measured in the last week of the trial was slightly greater in layer birds (.11 and .12 g x g body weight(-1) x d(-1) for broilers and layers respectively; P < .006). Polyubiquitin (UbI) messenger RNA was abundant in the muscles of these well-fed birds, but it showed little difference between strains. Muscle did not significantly express the UbII polyubiquitin gene. The ATP-dependent system conjugating ubiquitin to endogenous proteins had greatest activity in the gastrocnemius muscle of broiler birds but was not significantly different between breeds. Proteins cross-reactive with antisera to recombinant human proteasome regulatory subunits MSS1 (multicopy suppressor of SUG 1; S7) and TBP1 (tat binding protein 1; S6') were present in muscle homogenates from both strains of bird. The chick equivalent of TBP1 was more abundant in breast muscle of broiler birds than in leg muscle, or in either muscle of layers. Antiserum to recombinant yeast subunit mts2 (mitosis temperature sensitive gene 2; S4) did not react with any protein of the expected size but detected a 30-kDa peptide that was not associated with the 26S proteasome; this was found only in muscle from the layer strain. Hence, during normal growth of chickens, rates of protein degradation are not controlled by the expression of ubiquitin mRNA or the conjugation of ubiquitin. However, the composition of the 26S proteasome may be a regulatory factor.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1998

Favorable prognosis for children with Pfeiffer syndrome types 2 and 3: implications for classification.

Pfeiffer syndrome (PS) is an autosomal dominant condition comprising bilateral coronal craniosynostosis, midface hypoplasia with a beaked nasal tip, and broad and medially deviated thumbs and great toes. It is a clinically variable disorder and has been divided into three subtypes [Cohen, 1993: Am J Med Genet 45:300-307]. Type 1 represents the less severe cases, while types 2 and 3 are the more severe cases. These latter types tend to have a higher risk for neurodevelopmental problems and a reduced life expectancy. Here we review the clinical course of seven children with PS type 3. All of these children had severe manifestations of PS; however, development was essentially normal in three, mild delay was noted in two, and moderate delay in one. Favorable outcomes in children with types 2 and 3 PS were also documented by Moore et al. [1995: Cleft Pal-Craniofac J 32:62-70]. These cases illustrate that while children with PS types 2 and 3 have an increased risk for neurodevelopmental difficulties, a favorable outcome can be achieved in some cases with aggressive medical and surgical management. Finally, although such management should be the rule for PS types 2 and 3, it needs to be remembered that normal outcome is not the rule. The prognosis for favorable neurodevelopmental outcome and/or life expectancy remains guarded in most cases.

Acrocephalosyndactylia↗
PubMed1997

Synthetic, structural and biological studies of the ubiquitin system: synthesis and crystal structure of an analogue containing unnatural amino acids.

Ubiquitin is a 76-amino acid protein involved in the targeting for destruction of proteins in the cell. The protein can readily be synthesized chemically affording an extra dimension to studies of protein stability. Ubiquitin with various modifications to the hydrophobic core has been synthesized. In particular, two core amino acids have been replaced by aminobutyric acid (Val-26) and norvaline (for Ile-30) and the product crystallized. The refined crystal structure shows an overall contraction of the molecule and the side chain of Nva-30 rotates relative to Ile-30. However, the side chain rotation is not sufficient to compensate for the effect of the loss of the methyl group and hence a small cavity is introduced into the structure, which decreases the stability of the protein. The biological behaviour of the modified protein is unaltered. The observed changes in stability are of the magnitude expected for the removal of methyl groups from the hydrophobic core of a protein. Interestingly, the effect appears to be independent of the position of the removed methyl group. The intact structure, but not its stability, is important for recognition by the biological conjugating system.

Aminobutyrates↗
PubMed1997

Atrial flutter: an uncommon pediatric manifestation of hyperthyroidism.

OBJECTIVE: Atrial flutter is an uncommon arrhythmia in the pediatric population except for the immediate newborn period or following atrial repair of congenital heart disease. In children the diagnosis of atrial flutter may be difficult, attributable to rapid atrioventricular conduction and superimposition of flutter waves on QRS and T waves. Atrial flutter secondary to hyperthyroidism has been rarely reported in older adults, but there are no reports of children presenting with atrial flutter as the initial manifestation of hyperthyroidism. CASE REPORT: We report an interesting case of hyperthyroidism in a 3-year-old presenting with congestive heart failure and atrial flutter with 1:1 atrioventricular conduction. The responses to adenosine administration and to cardioversion were unusual and ultimately helpful in suggesting the diagnosis of hyperthyroidism. CONCLUSION: When atrial flutter is encountered in a pediatric patient in whom there is 1:1 atrioventricular conduction, a lack of a response to adenosine, and persistent sinus tachycardia after cardioversion, the clinician should be alert to the possibility of thyrotoxicosis.

Adenosine↗
PubMed1996

Development of a novel derivatization reagent for the sampling and analysis of total isocyanate group in air and comparison of its performance with that of several established reagents.

Analytical reference standards generally are not available for non-monomeric isocyanate species, making accurate identification and quantitation by high-performance liquid chromatography (HPLC) difficult. A successful derivatizing reagent must react rapidly with all isocyanate groups, the derivatized isocyanate must be detectable selectively and at very low levels, and the detector used for quantitation must give a response proportional to the number of derivatized isocyanate groups present. A novel derivatizing reagent, 1-(9-anthracenylmethyl)piperazine (MAP), was prepared in an attempt to achieve these goals. Derivatives were prepared by reacting five mono- and difunctional isocyanates with MAP and three other established isocyanate derivatizing reagents. These reagents included 1-(2-methoxyphenyl)piperazine (MOPP),9-(methylaminomethyl)anthracene (MAMA), and tryptamine (TRYP). The relative reactivities of MAP, MOPP, TRYP, and MAMA with phenyl isocyanate were found to be 100, 88, 30, and 25, respectively. Average molar absorptivities at the absorbance maxima +/- compound-to-compound variabilities were, for MAP: 1.47 x 10(5) +/- 3.50%; MAMA: 1.38 x 10(5) +/- 7.07%: and TRYP: 3.98 x 10(4) +/- 13.1%. Average fluorescence responses were, for MAP: 100 +/- 32.6%; MAMA: 41.0 +/- 58.8%; and TRYP: 2.27 +/- 15.6%. A comparison of MAP and MOPP ureas by HPLC/ultraviolet (UV)/electrochemical (EC) gave average responses for UV, EC, and EC/UV for MAP: 117 +/- 7.3%, 52.1 +/- 6.6%, and 0.447 +/- 10.7%, respectively; for MOPP: 24.3 +/- 62.5%, 76.7 +/- 28.5%, and 4.28 +/- 59.1%, respectively. The favorable performance of MAP warrants its further study as a reagent for the determination of total isocyanate group in air.

Air Pollutants, Occupational↗
PubMed1995

Developmental changes of the 26 S proteasome in abdominal intersegmental muscles of Manduca sexta during programmed cell death.

cDNA clone MS73 codes for an ATPase that is a regulatory subunit of the 26 S proteasome. Reverse transcriptase polymerase chain reaction analysis demonstrates that the expression of the gene dramatically increases in the pre-eclosion period. Western analyses show increases in other related. ATPases including MS73, MSS1, and mts2 but not TBP1. A similar increase in the 30-kDa subunit of the 20 S proteasome occurs. There are accompanying large changes in the peptidase activities of the 26 S proteasome. Relative to the 30-kDa subunit, there is no change in MSS1 and MS73, a 3-fold increase in mts2, and a 5-fold decline in TBP1. A large increase in the concentration of 26 S proteasomes together with extensive regulatory reprogramming may facilitate rapid muscular proteolysis.

Algorithms↗
PubMed1995

Adenotonsillectomy for treatment of obstructive sleep apnea in children.

OBJECTIVES: To determine (1) the prevalence of obstructive sleep apnea (OSA) in children with a suggestive history; (2) the effectiveness of surgery in treating OSA in children; and (3) factors that may help the physician select patients who have physiologically significant OSA and are likely to respond to surgery. DESIGN: Prospective study. PATIENTS: Sixty-nine children aged 1 to 14 years who were referred to the otolaryngologist for evaluation of suspected OSA. INTERVENTIONS: Thirty children with a respiratory disturbance index (RDI) greater than 5 underwent adenotosillectomy. Twenty-six of the 30 children had follow-up polysomnography. MAIN OUTCOME MEASURES: Polysomnography after surgery. RESULTS: Thirty-five (51%) of 69 children had an RDI greater than 5 on polysomnography. Twenty-six of the 30 children who underwent adenotonsillectomy for OSA had follow-up polysomnography. All 26 children had a lower RDI after surgery, although four patients still had an RDI greater than 5. A preoperative RDI of 19.1 or less predicted a postoperative RDI of 5 or less. History and physical findings were not useful in predicting outcome. CONCLUSIONS: All patients improved with adenotonsillectomy, but patients with the most severe RDI often had many respiratory events after surgery. History and physical examination alone are not sufficient to assess the severity of OSA or the likelihood of an adequate response to surgical treatment.

Adenoidectomy↗
PubMed1995

The abnormal isoform of the prion protein accumulates in late-endosome-like organelles in scrapie-infected mouse brain.

The prion encephalopathies are characterized by accumulation in the brain of the abnormal form PrPsc of a normal host gene product PrPc. The mechanism and site of formation of PrPsc from PrPc are currently unknown. In this study, ME7 scrapie-infected mouse brain was used to show, both biochemically and by double-labelled immunogold electron microscopy, that proteinase K-resistant PrPsc is enriched in subcellular structures which contain the cation-independent mannose 6-phosphate receptor, ubiquitin-protein conjugates, beta-glucuronidase, and cathepsin B, termed late endosome-like organelles. The glycosylinositol phospholipid membrane-anchored PrPc will enter such compartment for normal degradation and the organelles may therefore act as chambers for the conversion of PrPc into infectious PrPsc in this murine model of scrapie.

Animals↗
PubMed1995

Reproducibility and validity of a food-frequency questionnaire designed for use in girls age 7 to 12 years.

This study focused on a food-frequency questionnaire (FFQ) designed to measure nutrient intake in girls aged 7 to 12 years, inclusive. The instrument's reproducibility and validity were assessed using food records (FRs) as gold standards of measurement. Log-transformed nutrient intake estimates were compared from two FFQs and between FFQs and FRs. Intraclass correlation coefficients measuring the reproducibility of the FFQ ranged from 0.11 (starch) to 0.69 (fiber). Intraclass correlation coefficients measuring agreement between FFQ and 14l-day FR data varied between 0.15 (starch) and 0.68 (vitamin B2) for the first, and between 0.06 (starch) and 0.95 (vitamin B1) for the second FFQ. FFQs were in the best agreement with FRs for the following nutrients: fiber, vitamin B1, vitamin B2, vitamin C, and beta-carotene. Joint classifications revealed that overall, 36% of subjects were similarly categorized by FFQ and FR, and 70% of those in the lowest or highest FR quartiles were were found in the lowest or highest FR quartiles were found in the lowest or highest two FFQ quartiles, respectively.

Ascorbic Acid↗
PubMed1995

Investigation of the ability of MDHS method 25 to determine urethane-bound isocyanate groups.

Method 25 for the Determination of Hazardous Substances (MDHS 25) of the Health and Safety Executive of the United Kingdom attempts to identify and quantify all isocyanate species in an air sample. Isocyanate species are derivatized with 1-(2-methoxyphenyl)piperazine (MOPP) and analyzed by high-performance liquid chromatography (HPLC) with tandem ultraviolet/electrochemical (UV/EC) detection. The method identifies peaks as being isocyanate-derived if the EC/UV detector response ratio is between 0.75 and 1.5 times that of the derivatized monomer. This investigation sought to determine if the method correctly identifies and accurately quantifies intermediates created during polyurethane formation that possess free isocyanate groups. Model compounds derived from 2,4-toluene diisocyanate (2,4-TDI) and ethylene glycol were prepared. These urethane species contained two ("dimer") and three ("trimer") TDI units and terminal MOPP-derivatized isocyanate groups. Like monomeric 2,4-TDI/MOPP urea, each contained two derivatized isocyanate groups per molecule. This investigation found that neither the UV nor the EC response is proportional to the number of isocyanate groups present in the model compounds. Therefore, it is concluded that MDHS 25 is neither capable of correctly identifying TDI-urethane intermediates possessing MOPP-derivatized isocyanate groups nor is it capable of accurately quantifying these isocyanate groups. The proposed solution to this problem is the utilization of a derivatizing reagent that yields derivatized isocyanate species whose detector responses come more exclusively from the derivatized isocyanate moiety and, therefore, are more proportional to the number of derivatized isocyanate groups.

Chromatography, High Pressure Liquid↗
PubMed1995

Laryngeal hamartoma: a rare congenital abnormality.

Hamartoma is a rare congenital abnormality of the larynx that must be considered in the differential diagnosis of benign lesions of the larynx. Presenting symptoms may include changes in voice, eating, and activity levels, and respiratory complaints. We treated a 2 1/2-year-old boy with an 8-month history of upper airway compromise. Radiographic studies showed a rounded, right-sided, supraglottic soft tissue mass. Direct laryngoscopy revealed a well-mucosalized, encapsulated, firm 3 x 2.5-cm mass that originated from the right supraglottic structures. The mass was excised endoscopically. Histologic examination revealed a hamartoma. At 18 months, the patient has had an uneventful postoperative course.

Child, Preschool↗
PubMed1995

Otitis media following tympanostomy tube placement in children with IgG2 deficiency.

Children with IgG2 deficiency commonly develop recurrent acute otitis media. It is believed that these infections are secondary to impaired antibody response rather than eustachian tube dysfunction and are therefore less responsive to treatment with tympanostomy tubes. The authors compared the incidence of acute otitis media in IgG2-deficient patients following tympanostomy tube placement with controls in a retrospective cohort study. The charts of 20 patients (10 with IgG2 deficiency and 10 controls) were reviewed. Episodes of otitis media were recorded for 12 months. IgG2-deficient patients experienced three times as many occurrences of otitis media as did controls. This suggests that otitis media is much more common in these patients following tympanostomy tube placement. We believe that an immunodeficiency workup should be considered in patients with multiple episodes of otitis media following placement of tympanostomy tubes.

Acute Disease↗