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Biomedical subjects

R L Shelton

Publications and source records attributed to R L Shelton.

At least 19 recordsLinked to original sources
PubMed1989

Children's categorization of consonants by manner and place characteristics.

Ten normal-speaking 5-year-olds and 10 normal-speaking 7-year-olds were required to categorize consonants as "dripping" (stop) or "flowing" (fricative) and as "tongue" (lingual place of articulation) or "lip" (labial place of articulation). Both groups of children performed more accurately than would be expected on the basis of chance alone. However, 5-year-olds performed more poorly than did 7-year-olds, primarily because 5-year-olds were significantly less accurate than 7-year-olds in categorizing according to manner. Children's ability to categorize was evaluated as an indicator of their awareness of feature characteristics of consonants. Their performance does not unambiguously reflect feature awareness but may be related to other variables such as their use of response strategies or the nature of the task.

Age Factors↗
PubMed1986

Intraoral air pressure and oral air flow under different bleed and bite-block conditions.

Intraoral pressures and oral flows were measured as normal talkers produced /p lambda/ and /si/ under experimental conditions that perturbed the usual aeromechanical production characteristics of the consonants. A translabial pressure-release device was used to bleed off intraoral pressure during /p/. Bite-blocks were used to open the anterior bite artificially during /s/. For /p/, intraoral pressure decreased and translabial air leakage increased as bleed orifice area increased. For /s/, flow increased as the area of sibilant constriction increased, but differential pressure across the /s/ oral constriction did not vary systematically with changes in its area. Flow on postconsonantal vowels /lambda/ and /i/ did not vary systematically across experimental conditions. The data imply that maintenance of perturbed intraoral pressure was more effective when compensatory options included opportunity for increased respiratory drive and structural adjustments at the place of consonant articulation rather than increased respiratory drive alone.

Adult↗
PubMed1986

Use of a hinge-type speech prosthesis.

This report describes a hinge-type speech prosthesis and its owner's use of the two halves of her cleft velum to elevate the velar section of the prosthesis. With the prosthesis, her speech is free from articulation errors, audible nasal emission, and hypernasality. Acquisition of the ability to move the velar section is discussed.

Cleft Palate↗
PubMed1985

Location of the maltosyl isothiocyanate binding site on the human erythrocyte glucose transporter.

The covalent affinity probe maltosyl isothiocyanate (MITC) has been used previously to identify the glucose transporter of human erythrocytes as a component of band 3. By use of limited proteolysis, the site on the Mr 100 000 protein to which MITC attaches has been localized to a 17 000-dalton region near the center of the polypeptide chain which is intimately associated with the membrane. The erythrocyte anion transporter, which is probably homologous to the glucose carrier, has a corresponding segment which is known to bind the covalent affinity label 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid [Ramjeesingh, M., Gaarn, A., & Rothstein, A. (1980) Biochim. Biophys. Acta 559, 127-139]. These results suggest that, in addition to having structural features in common, the two carrier proteins may be quite similar with regard to functional organization.

Affinity Labels↗
PubMed1985

Custom-fabricated masks for aeromechanical measures.

A technique is described for the construction of custom fabricated face masks designed for use in aeromechanical studies of individuals with speech disorders, such as those associated with craniofacial defects. The wax-elimination method of mask fabrication described herein is similar to routine dental laboratory procedures. Materials employed are heat-cured acrylic resin for the body of the mask and heat-cured resilient liner for the tissue contacting surface of the mask.

Acrylic Resins↗
PubMed1984

Quantitation of the major proteins of the human erythrocyte membrane by amino acid analysis.

The proteins of the human erythrocyte membrane have been separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the resulting gel cut into 2-mm sections, and the amino acid content and composition of each slice measured using a sensitive method of amino acid analysis. The distribution of proteins among bands coincides closely with that estimated using staining intensity. Composition data for the major bands agree well with those reported for the purified proteins in all cases except that of band 4.5. Using quantitative amino acid analysis and resistive particle counting the total protein content of purified membranes was found to be 3.75 X 10(-13) g/cell, which is substantially less than previous estimates based on indirect methods. These data are used to calculate the number of copies of each major protein in a single erythrocyte.

Amino Acids↗
PubMed1984

Oronasal fistulas, intraoral air pressure, and nasal air flow during speech.

Aeromechanical data are presented for six patients with oronasal fistulas and one with a maxillary cleft. Patients were studied with the defects open and again with them closed with either acrylic dental appliances, dental wax, or denture adhesive. Only the largest openings appeared to allow sufficient loss of intraoral air pressure to weaken obstruent consonants. All but the smallest of the defects were associated with nasal air flow during syllable strings. Thus the data are compatible with a hypothesis that in the presence of small air leaks patients maintain sufficient intraoral air pressure for accurate consonant production. Presumably this is achieved by increase in respiratory effort. The relationship between fistula size and speech or speech related variables appears to be similar to that between area of the velopharyngeal opening and speech. However, the fistula is more constant in area across utterances than is the pathological velopharyngeal mechanism.

Adolescent↗
PubMed1983

Reconstitution of glucose transport using human erythrocyte band 3.

Band 3 and the diffuse component of zone 4.5, designated band 4.5.B, have been separately prepared from human erythrocyte membranes and incorporated into the membranes of 150 nm 1-palmitoyl-2-oleoyl phosphatidylcholine vesicles. The rates of glucose influx into these vesicles were measured under zero-trans conditions. Both sets of vesicles exhibited substrate-saturable transport which was inhibited by phloretin. However, the specific activity of the band 3 vesicles, 292 mumol X min-1 X (mg protein)-1, was more than twice that of the band 4.5.B vesicles, and the turnover number of transporters in the band 3 vesicles was at least 4-fold greater than those in the 4.5.B vesicles. Very little background density was visible in the band 4.5 region of erythrocyte membranes protected from degradation. In unprotected membranes, band 4.5.B was abundantly present, could be purified, and had glucose transport activity. Previously we have shown (Biochemistry 19, 1205 (1980] that maltosyl isothiocyanate, an affinity label for the glucose transporter, labelled a single 100 000 Mr protein of the intact erythrocyte membrane. Based upon the results of both affinity labelling and reconstitution we suggest that the native glucose transporter is a component of band 3, and that band 4.5.B contains a partially active fragment of the native transporter.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1982

A technique for identifying the subgroup membership of certain misarticulating children.

Cluster analysis was used to identify two homogeneous clusters of 8-9 1/2-year-old children who misarticulated /s/, /r/, or both. The analysis was based on the children's scores on 40 measures of language, reading, auditory processing, and other variables. Discriminant function analysis was then used to identify a subset of five measures and a means of computing classification scores. These measures and the classification scores can be used to identify the cluster membership of new subjects. The use of classification scores for identifying cluster membership was cross-validated against cluster analysis of a second group of children. The two clusters are described in terms of their performance on language and reading measures.

Articulation Disorders↗
PubMed1979

Influence of the emetic reflex on vasopressin release in man.

The mechanisms underlying the frequent association of nausea and vomiting with elevations of plasma vasopressin(PAVP) were studied in man and rat. After oral water loads (N = 16), plasma osmolality fell in all human subjects and was associated with a decline in PAVP in 14 asymptomatic human subjects. In 2 human subjects, nausea occurred and was associated with increases in PAVP, without changes in blood pressure. During ethanol infusion (N = 28), PAVP was suppressed unless nausea supervened. In 4 nauseated human subjects, PAVP escaped from ethanol inhibition and rose to levels 10 times basal, despite the absence of hemodynamic changes. Apomorphine, a potent dopamine agonist and emetic agent, was administered to human volunteers in doses of 7 to 24 microgram/kg. There was no increase in PAVP in 3 human subjects who remained asymptomatic (7 to 16 microgram/kg). Ten human subjects experienced nausea after 16 microgram/kg, which was followed shortly by marked increases in PAVP. Emesis occurred in 5 human subjects given 16 to 24 microgram/kg, and was followed by PAVP levels similar to those seen with nausea alone. In 7 human subjects from the nausea group, the repeat study (16 microgram/kg) after pretreatment with dopamine antagonist (haloperidol, N = 4; fluphenazine, N = 3) resulted in complete blockage of apomorphine-induced AVP release. In rats, which lack an emetic reflex, apomorphine doses of 200 microgram/kg induced only slight increases in PAVP when compared to the response to 16 microgram/kg in man. These studies indicate that stimulation of the emetic reflex results in AVP-release in man. Nausea-mediated AVP release supervenes over concomitant osmolar or pharmacologic (ethanol) inhibition.

Alcohols↗
PubMed1979

Planning and self-assessment in articulatory training.

Children misarticulating the /r/ or /s/ speech sounds or both were identified, and assigned randomly to one of two groups. Each group received speech lessons that were similar. However, during response acquisition training, Group 1 was requested to plan articulatory movements mentally, produce the target sound, and assess the production. Group 2 practiced the training units without using the planning and assessment procedures. Group 1 exceeded Group 2 on generalization measures when the planning and assessment training was in effect.

Articulation Disorders↗
PubMed1978

Assessment of parent-administered listening training for preschool children with articulation deficits.

Two studies concerning preschool misarticulating children are reported. The first study was concerned with direct effects of two varieties of parent-administered listening training. The second study focused on the influence of that same training on children's responses to sound-production training. Subjects were assigned to one of three conditions: listening, reading-talking, and control. Children in the first group were provided training by their parents that was intended to focus the child's attention on consonants in syllables or words and to teach discrimination between correctly and incorrectly articulated consonants. Parents of children in the second group read to and talked with them about the material. Neither treatment group surpassed the control group in gains made on any auditory processing or articulatory measure employed, and some parents found the listening training frustrating. In the second study, a subset of the children in each of the three groups was given sound-production training. The data obtained did not show any effect from earlier listening experiences on sound-production performance.

Attention↗
PubMed1978

Human rights and distributive justice in health care delivery.

This paper was first presented at the Annual Meeting of the American Society of Christian Ethics, Toronto School of Theology, Toronto, Ontario in January 1977. Robert Shelton aims to focus on the concept of 'right to health care,' its related principle, 'distributive justice' in an attempt to suggest 'where we are' at present and where we perhaps ought to be heading. The paper is divided into three parts, which in their turn explore the moral grounds, the US general public's policy and the part justice and government are likely to play in the development and distribution of health care. He concludes by highlighting 'omissions', an intentional one of his own and the other a major gap in the literature.

Delivery of Health Care↗
PubMed1978

Videoendoscopic feedback in training velopharyngeal closure.

Each of two adolescents with velopharyngeal closure deficits was taught to position him or herself on an endoscope attached to a television camera and to observe the velopharyngeal port during the production of syllables and other units. The videoendoscope was then used as a training apparatus, and each subject was given practice attempting to increase velopharyngeal closure while producing vowels and syllables. Videorecordings of each subject made without feedback before, during, and after the training period were played to panels of observers who were to rate closure during each utterance, and the data obtained indicated that the subjects more frequently approximated complete closure as the study progressed but improved performance was not established on an automatic level. Suggestions are made for the refinement and further investigation of videoendoscopic closure training.

Adolescent↗
PubMed1977

Identification and description of homogeneous subgroups within a sample of misarticulating children.

A multivariate, hierarchical clustering procedure was used to identify homogeneous subgroups among 98 misarticulating children age eight years through nine years, six months. Clustering was based on 40 tests or measures of language, auditory processing, school achievement, oral structure, oral form recognition, and other phenomena. Clusters were described and then compared for performance on measures of articulation status and articulation improvement with training. Clusters were also derived from subsets of children who misarticulated only one sound, either /s/or/r/. Also, the subset of children who misarticulated /s/ was compared with children who misarticulated /r/ for performance on the measures classified above. Few of the clusters identified differed in articulation status or improvement with training.

Anthropometry↗
PubMed1977

Factor analysis of measures of articulation, language, auditory processing, reading-spelling, and maxillofacial structure.

This study was concerned with the correspondence between the classification of measures by clinical judgement and by factor analysis. Forty-six measures were selected to assess language, auditory processing, reading-spelling, maxillofacial structure, articulation, and other processes. These were applied to 98 misarticulating eight- and nine-year-old children. Factors derived from the analysis corresponded well with categories the measures were selected to represent.

Cephalometry↗