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Biomedical subjects

J B Palmer

Publications and source records attributed to J B Palmer.

At least 19 recordsLinked to original sources
PubMed2005

Cyclic motion of the soft palate in feeding.

The soft palate moves rhythmically during feeding, but the timing and frequency of this motion are not known. We tested the hypothesis that cyclic soft palate motion is temporally linked to cyclic jaw movement. Nine healthy, asymptomatic human subjects with normal dentition ate solid food coated with barium. Videofluorographic recordings showed that rhythmic motions of the soft palate during mastication were linked temporally to jaw motion. Soft palate motion occurred in every recording but not in every jaw cycle. The soft palate moved upward as the jaw opened, but the nasopharynx was not sealed. During swallowing, however, the soft palate invariably elevated during the intercuspal phase of jaw motion, sealing the nasopharynx. The frequency of soft palate cycles was lowest early in a feeding sequence and gradually increased as the sequence progressed from ingestion to swallowing. We conclude that cyclic movement of the soft palate in feeding is temporally linked to jaw motion.

Adult↗
PubMed2004

Comparison of adult and fetal cytokine secretion during mixed lymphocyte reactions.

Umbilical cord blood transplants are associated with a lower incidence of graft-versus-host disease (GVHD) than adult marrow or peripheral blood stem cell transplants, and this could be related to a difference in cytokine production between fetal and adult mononuclear cells after allogeneic stimulation. Mixed lymphocyte reactions (MLRs) involving adult cells were associated with greater interferon-gamma (IFNgamma) secretion than MLRs between cord blood cells, although IL-2 secretion was similar. Experiments in which T cells were separated from accessory cells then recombined in artificial combinations indicated that differences in T cells were primarily responsible for the greater [IFNgamma]:[IL-2] ratios generally found after MLRs involving adult cells compared to fetal cells, but accessory cells also influenced this ratio. The cellular basis for the observed difference was not established, but mononuclear cell preparations from cord blood contained significantly higher proportions of CD16(+)56(-) NK-type cells and a CD19(+)1c(+) B cell subset, as well as more CD45 RA-expressing nai;ve T cells.

Antigen-Presenting Cells↗
PubMed2001

Effect of liquid bolus consistency and delivery method on aspiration and pharyngeal retention in dysphagia patients.

There is no empirically derived consensus as to what food consistency types and method of food delivery (spoon, cup, straw) should be included in the videofluoroscopic swallowing (VFSS) studies. In the present study, we examine the rates of aspiration and pharyngeal retention in 190 dysphagic patients given thin (apple juice) and thick (apricot nectar) liquids delivered by teaspoon and cup and ultrathick (pudding-like) liquid delivered by teaspoon. Each patient was tested with each of the bolus/delivery method combinations. The fractions of patients exhibiting aspiration for each bolus/method of delivery combination were (1) thick liquids (cup), 13.2%; (2) thick liquids (spoon), 8.9%; (3) thin liquids (cup), 23.7%; (4) thin liquids (spoon), 15.8%, (5) ultrathick liquids (spoon), 5.8%. In each comparison [thick liquid (cup) vs. thick liquid (spoon), thin liquid (cup) vs. thin liquid (spoon), thick liquid (cup) vs. thin liquid (cup), thick liquid (spoon) vs. thin liquid (spoon), and thick liquid (spoon) vs. ultrathick liquid (spoon)], the p value for chi 2 was < 0.001. These results suggest that utilizing thin, thick, and ultrathick liquids and delivery by cup and spoon during a VFSS of a patient with mild or moderate dysphagia can increase the chances of identifying a consistency that the patient can swallow without aspirating and without pharyngeal retention after swallowing.

Administration, Oral↗
PubMed2001

Ontogeny of postnatal hyoid and larynx descent in humans.

Postnatal descent of the hyoid and larynx relative to the palate and mandible, which occurs uniquely in humans, is an anatomical prerequisite for quantal speech. This study tested the hypothesis that spatial constraints related to deglutition impose greater restrictions on the rate and degree of hyo-laryngeal descent than do adaptations for vocalization. Ontogenetic data on changes in the size and shape of the pharynx, the vocal tract, and the spatial positions of the larynx, hyoid, mandible and hard palate relative to each other and to the oral cavity were obtained for 15 males and 13 females from a longitudinal series of lateral radiographs (the Denver Growth Study) taken between the ages of 1 month and 14 years. To establish growth patterns, nine linear dimensions of the pharynx and 15 different pharyngeal and vocal-tract proportions were regressed against percentage growth. The results demonstrate that certain aspects of vocal-tract shape change markedly during ontogeny, especially in the first postnatal year and during the adolescent growth spurt. The ratio of pharynx height to oral cavity length (which is important for speech) decreases significantly (P<0.001) from 1.5 to 1.0 between birth and 6-8 years, after which it remains stable. In contrast, regression analyses indicated that superoinferior spatial relations between the positions of the vocal folds, the hyoid body, the mandible and the hard palate do not change significantly throughout the entire postnatal growth period (P<0.05). Sexual dimorphism in pharyngeal shape and size before the age of 14 years is very limited. The results suggest that the descent of the hyoid and larynx relative to the mandible is constrained by muscle function related to deglutition, highlighting the different functional roles of the hyoid during speech and oral transport.

Adolescent↗
PubMed2000

Evaluation and treatment of swallowing impairments.

Swallowing disorders are common, especially in the elderly, and may cause dehydration, weight loss, aspiration pneumonia and airway obstruction. These disorders may affect the oral preparatory, oral propulsive, pharyngeal and/or esophageal phases of swallowing. Impaired swallowing, or dysphagia, may occur because of a wide variety of structural or functional conditions, including stroke, cancer, neurologic disease and gastroesophageal reflux disease. A thorough history and a careful physical examination are important in the diagnosis and treatment of swallowing disorders. The physical examination should include the neck, mouth, oropharynx and larynx, and a neurologic examination should also be performed. Supplemental studies are usually required. A videofluorographic swallowing study is particularly useful for identifying the pathophysiology of a swallowing disorder and for empirically testing therapeutic and compensatory techniques. Manometry and endoscopy may also be necessary. Disorders of oral and pharyngeal swallowing are usually amenable to rehabilitative measures, which may include dietary modification and training in specific swallowing techniques. Surgery is rarely indicated. In patients with severe disorders, it may be necessary to bypass the oral cavity and pharynx entirely and provide enteral or parenteral nutrition.

Age Distribution↗
PubMed2000

Motions of the posterior pharyngeal wall in human swallowing: a quantitative videofluorographic study.

OBJECTIVE: To quantify segmental motions of the posterior pharyngeal wall during swallowing. DESIGN: Prospective study. SETTING: Hospital radiology suite. PARTICIPANTS: Six healthy adult volunteers. INTERVENTIONS: Videofluorography of the pharynx in posteroanterior and lateral projections during water swallows by 6 able-bodied adults. Radiopaque suction markers, inserted through the nose, were attached by suction to the midline of the posterior pharyngeal wall of the upper and lower oropharynx, pharyngoesophageal segment (PES), or cervical esophagus. MAIN OUTCOME MEASURES: Displacement of the larynx, hyoid bone, and markers. RESULTS: Marker pathways were ovoid in the oropharynx but linear in the PES and esophagus. Marker displacement was greatest in the vertical dimension, intermediate in posteroanterior dimension, and smallest in mediolateral dimension. Vertical displacement was greater for the PES marker than for larynx, hyoid bone, or oropharynx markers (p < .001), so that the pharynx shortened significantly during each swallow. Marker displacement was unaffected by bolus volume. CONCLUSIONS: The pharyngeal wall shortened during swallowing. The mechanism for PES elevation may differ from that of laryngeal elevation. Shortening of the pharynx may be produced by contraction of the pharyngeal suspensory muscles and traction on the larynx by suprahyoid muscles.

Adult↗
PubMed1999

Food transport and bolus formation during complete feeding sequences on foods of different initial consistency.

Food movements during complete feeding sequences on soft and hard foods (8 g of chicken spread, banana, and hard cookie) were investigated in 10 normal subjects; 6 of these subjects also ate 8 g peanuts. Foods were coated with barium sulfate. Lateral projection videofluorographic tapes were analyzed, and jaw and hyoid movements were established after digitization of records for 6 subjects. Sequences were divided into phases, each involving different food management behaviors. After ingestion, the bite was moved to the postcanines by a pull-back tongue movement (Stage I transport) and processed for different times depending on initial consistency. Stage II transport of chewed food through the fauces to the oropharyngeal surface of the tongue occurred intermittently during jaw motion cycles. This movement, squeeze-back, depended on tongue-palate contact. The bolus accumulated on the oropharyngeal surface of the tongue distal to the fauces, below the soft palate, but was cycled upward and forward on the tongue surface, returning through the fauces into the oral cavity. The accumulating bolus spread into the valleculae. The total oropharyngeal accumulation time differed with initial food consistency but could be as long as 8-10 sec for the hard foods. There was no predictable tongue-palate contact at any time in the sequence. A new model for bolus formation and deglutition is proposed.

Adult↗
PubMed1999

Helicobacter pylori infection rates in duodenal ulcer patients in the United States may be lower than previously estimated.

OBJECTIVE: Published studies have estimated the rate of Helicobacter pylori (H. pylori) infection in patients with duodenal ulcer disease to be as high as 95%; the majority of remaining duodenal ulcers have been attributed to the use of ulcerogenic drugs such as nonsteroidal antiinflammatory drugs (NSAIDs). We aimed to assess the H. pylori prevalence rates of U.S. duodenal ulcer patients in large, well-controlled studies. METHODS: More than 2900 patients with endoscopically diagnosed non-NSAID duodenal ulcers were enrolled in a series of six placebo-controlled, double-blind studies conducted in the United States that assessed H. pylori using a combination of tests. Patients were considered infected with H. pylori only if culture growth was observed, or both histological and CLOtest results were positive. Patients were considered uninfected if the results of at least two tests were negative. Patients with missing test results, results of only a single test, or conflicting test results were not evaluable for H. pylori assessment. RESULTS: Of the 2394 endoscopically diagnosed evaluable duodenal ulcer patients, 73% (1737) were confirmed infected with H. pylori at study entry. CONCLUSIONS: The results of six carefully designed and controlled studies suggest that an assumed H. pylori infection rate of approximately 95% may overestimate the actual rate of H. pylori infection in duodenal ulcer patients in the United States. Although H. pylori infection is an important factor in the etiology of noniatrogenic duodenal ulcer disease, other factors may predominate in some patients and should not be overlooked in determining an appropriate course of treatment. The empiric use of antibiotic therapy for ulcer patients without confirmation of the presence of H. pylori cannot be recommended.

Adolescent↗
PubMed1998

Intra- and interrater variation in the evaluation of videofluorographic swallowing studies.

The objective of this study was to determine the inter- and intrarater reliability in evaluating videofluoroscopic swallowing studies (VFSS). Participants included 4 physicians (3 physiatrists and 1 internist) and 5 speech-language pathologists with at least 5 years experience in evaluating VFSS. The main outcomes of the study were reliability ratios of positive and negative tests in inter- and intrarater evaluations. Raters independently rated each of 20 VFSS on two separate occasions. Traits evaluated included oral stage impairment, aspiration, pharyngeal retention, and several functional components: timing of swallow onset, adequacy of velopharyngeal apposition, laryngeal elevation, epiglottic tilt, pharyngeal contraction, and pharyngoesophageal (PE) segment opening. Reliability varied widely depending on food type and the trait under evaluation. Inter- and intrarater reliability ratios did not differ widely. Reliability ratios values typically were highest (greater than 90%) for aspiration, especially with solid food, and lowest for the functional components. It was concluded that inter- and intrarater reliability in VFSS are adequate for evaluating oral stage, laryngeal penetration, and aspiration and pharyngeal retention, but questionable for functional components.

Cineradiography↗
PubMed1998

Bolus aggregation in the oropharynx does not depend on gravity.

OBJECTIVE: To determine whether bolus aggregation in the oropharynx (before swallowing) depends on gravity. DESIGN: Before-during trial, with subjects serving as their own controls. SETTING: Hospital radiology suite. PARTICIPANTS: Five asymptomatic adult volunteers. INTERVENTIONS: Videofluorography was performed while subjects ate soft and hard foods containing barium, first seated upright and then kneeling face down (quadruped position). MAIN OUTCOME MEASURES: Duration of food processing in the oral cavity, bolus aggregation in the valleculae, and pharyngeal swallow. RESULTS: Transport of chewed solid food from the oral cavity to the oropharynx (stage II transport) typically started several seconds before onset of swallow, regardless of head position or initial food consistency. Bolus aggregation in the valleculae (between the epiglottis and the tongue) began an average of 1.7 +/- 2.5sec before the onset of the pharyngeal swallow (p < .001). Stage II transport was driven by tongue-palate contact. CONCLUSIONS: Transport of chewed solid food from the oral cavity to the pharynx is driven actively by tongue-palate contact and does not depend on gravity. A bolus may accumulate in the valleculae for several seconds before the swallow.

Adult↗
PubMed1998

Developmental variation in stem-cell markers from human fetal liver and umbilical cord blood leukocytes.

Fetal tissues containing haematopoietic stem cells (HSC) are of potential value for allogeneic transplantation and gene therapy. Flow cytometry was used to investigate CD34+ cells from human fetal livers and umbilical cord (placental) blood (UCB). CD34+ cells, expressed as a proportion of CD45-positive leukocytes, were much more abundant in fetal livers (mean 38%) than in UCB (mean 0.3%), but fetal liver cells had lower proportions of CD34+HLA-DR+ and CD34+ CD38+ subsets. In fetal liver, there was a strong and highly significant inverse correlation between CD34+ cells (as a proportion of total leukocytes) and gestational age; no such relationship was found for subsets of CD34+ cells coexpressing CD38 or CDw90 (Thy-1), but CD34+HLA-DR+ cells were less abundant in first-compared to second-trimester livers. In UCB, a trend towards decreasing CD34+ cells (as a proportion of total leukocytes) with increasing gestational age in late pregnancy was also observed. The composition of fetal leukocytes changes during development, and therefore the timing of fetal HSC harvesting could be of relevance to transplantation outcome.

Antigens, CD↗
PubMed1997

Tongue-jaw linkages in human feeding: a preliminary videofluorographic study.

Motions of the tongue and jaw are closely coupled during feeding in mammals, but this relation has not been studied in humans. A videofluorographic method for measuring tongue movement relative to jaw motion using small radiopaque markers affixed to the tongue with dental adhesive was developed and tested in five individuals. Sagittal movements of the anterior tongue marker (ATM) and the lower jaw were measured for complete feeding sequences with a computerized image-analysis system. The ATM and jaw moved in loosely linked, semirhythmic cycles. Vertical and horizontal maxima of ATM motion were determined for each motion cycle in relation to maximum and minimum gape (greatest jaw opening and closing, respectively). The amplitude of tongue movements and their timing differed between hard and soft foods (p < 0.001). For both food types, motions varied as the feeding sequence progressed from ingestion to terminal swallow (p < 0.001). A basic temporal sequence was found in 70% of the 224 cycles analysed. On average, the ATM reached its most inferior position just after maximum gape, its most posterior during jaw closing, its most superior just after minimum gape, and its most anterior during jaw opening (p < 0.001). This study confirms that tongue and jaw movements are linked during human feeding, as they are in other mammals.

Adult↗
PubMed1994

The efficacy and tolerability of inhaled salmeterol and individually dose-titrated, sustained-release theophylline in patients with reversible airways disease.

In a double-blind, double-dummy, cross-over, multicentre study, 141 patients with moderate reversible airways disease were randomized to receive either 50 micrograms salmeterol via a metered dose inhaler or individually dose-titrated oral theophylline, both twice daily for a 2-week period. Just over half (n = 77) the patients had received theophylline before, but 64 patients were new to theophylline therapy. Efficacy was based on lung function data and symptom scores. Salmeterol produced significantly higher increase in mean morning peak expiratory flow (PEF) of 161 min-1 (P < 0.001; 95% Confidence Interval (CI); 8-241 min-1) and mean evening PEF of 151 min-1 (p < 0.001; 95% CI; 7-221 min-1) compared with theophylline therapy. Further analysis of the data revealed that the increase in PEF with salmeterol compared with theophylline was highest in a sub-group of patients new to theophylline therapy. Patients on salmeterol had significantly less night-time awakenings than those on theophylline (P = 0.011) and significantly less daytime symptoms (P = 0.017). There was also a significant increase in the number of nights (P = 0.013) and days (P < 0.001) on salmeterol when no additional salbutamol was required compared with theophylline. Theophylline produced a higher incidence of adverse events compared with salmeterol. The results of this study show that inhaled salmeterol is more effective and better tolerated than individually dose-titrated oral theophylline over a 2-week study period in patients with moderate asthma.

Administration, Inhalation↗
PubMed1994

Multidrug resistance gene (MDR 1) expression in neuro-axial tumours of children and young adults.

Drug resistance in many cancers outside the CNS has been associated with over-expression of the multidrug resistance gene (MDR1), which codes for the transmembrane efflux pump P-glycoprotein (Pgp). To determine whether tumours of the neuroaxis over-express MDR1 and to identify the site of Pgp expression we examined 50 tumour specimens from 46 children and young adults using immunocytochemistry. Pgp was not expressed by any neoplastic cells, but was detected in the endothelium of tumour blood vessels in 35 of the 50 samples (70%). 11/35 (31%) were Pgp positive in the majority of vessels, 11/35 (31%) in a proportion, but < 50% of vessels, and 13/35 (37%) in one or two vessels. Pgp was also detected in surrounding normal brain capillaries. MDR1 may play a role in the chemoresistance of neuro-axial tumours either by its expression in the normal blood-brain barrier or by forming a blood-tumour barrier. The proportion of vessels expressing Pgp may determine the degree of resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗