Early Life Vaccination of Companion Animal Pets

Development of the immune system of mammalian animal species parallels that of humans and involves the innate and adaptive (acquired) immune responses acting together with the thymus gland. Consequently, issues surrounding the adequacy and safety of vaccinations to protect pet animals from their relevant infectious diseases need to be addressed just as they are for humans. Pet animals, especially canines, also have unique needs because of the wide diversity of purebred and mixed breeds that vary greatly in size, type, temperament, and even maturation rates. Furthermore, pets in early life encounter a series of changes that can affect their development and induce stressors including parasite control, new homes and environment, novel foods, and the socialization that is essential at a time when vaccinations need to be given. While recognizing that this overall need is becoming more understood, current vaccination policy guidelines for companion animals are still only adhered to by about 40% of veterinarians worldwide. Clearly, vaccination of pets should no longer be considered as "one size fits all".

Survey of canine use and safety of isoxazoline parasiticides

A veterinarian and pet owner survey (Project Jake) examined the use and safety of isoxazoline parasiticides given to dogs. Data were received during August 1–31, 2018 from a total of 2,751 survey responses. Forty‐two percent (1,157) reported no flea treatment or adverse events (AE), while 58% (1594) had been treated with some parasiticide for flea control, and of those that received a parasiticide, the majority, or 83% (1,325), received an isooxazoline. When any flea treatment was given, AE were reported for 66.6% of respondents, with no apparent AE noted for 36.1%. Project Jake findings were compared to a retrospective analysis of publicly available Food and Drug Administration (FDA) and European Medicines Agency (EMA) reported AE. The number of total AE reported to FDA and EMA were comparable, although a 7 to 10 times higher occurrence of death and seizures was reported from the EMA or from outside the United States (US). Serious AE responses for death, seizures and neurological effects reported in our survey were higher than the FDA but moderately lower than the EMA reports. These sizable global data sets combined with this pre‐ and post‐parasiticide administration survey indicated that isoxazoline neurotoxicity was not flea‐ and tick‐specific. Post‐marketing serious AE were much higher than in Investigational New Drug (IND) submissions. Although the labels have recently been updated, dogs, cats and their caregivers remain impacted by their use. These aggregate data reports support the need for continued cross‐species studies and critical review of product labelling by regulatory agencies and manufacturers.

Duration of immunity after rabies vaccination in dogs: The Rabies Challenge Fund research study

A prospective study of 65 research beagles kept in a rabies-free environment was undertaken to determine the duration of immunity after they received licensed rabies vaccines. The eventual goal was to extend mandated rabies booster intervals to 5 or 7 years and help reduce the risk of vaccine-associated adverse events. Three groups of dogs were vaccinated with 1 of 2 commercial rabies vaccines or saline at 12 and 15 weeks of age. Beginning 5 years 5 months later, vaccinated and unvaccinated dogs were challenged with virulent rabies virus and observed for 90 days over a series of 3 trials. Humoral and cellular immune responses were examined by serology and flow cytometry. Brain tissue from all challenged dogs was tested for rabies virus. Challenge trial 1 was confounded due to insufficiently virulent virus. In trials 2 and 3 virulent challenge provided 100% mortality in controls. Vaccinate survival was 80% (4/5) after 6 years 7 months, 50% (6/12) after 7 years 1 month, and 20% (1/5) after 8years 0 months. Antibody responses 12 days post-challenge correlated strongly with survival. In a separate non-challenge trial, administration of either a recombinant or a killed rabies vaccine demonstrated memory antibody responses 6 years 1 month after initial vaccination compared with unvaccinated controls. Our data demonstrated that i) duration of immunity to rabies in vaccinated dogs extends beyond 3 years; ii) immunologic memory exists even in vaccinated dogs with serum antibody titer < 0.1 IU/mL; and iii) non-adjuvanted recombinant rabies vaccine induces excellent antibody responses in previously vaccinated dogs 14 days after administration.

Diagnosis of Feline Food Sensitivity and Intolerance Using Saliva: 1000 Cases

This prospective study assessed the efficacy of a novel saliva-based immunoassay of IgA- and IgM-antibodies in predicting feline food sensitivities and intolerances. Clinical samples were obtained from 1000 cats proven or suspected to have food intolerances. Most were of domestic shorthair breed type, over 10 years of age, and weighed around 5 kg; they were equally distributed between spayed females and neutered males. Saliva was collected after at least an 8-h fast with a dental cotton rope, placed in a double-sleeved saliva collection tube, and sent to the laboratory. Salivary antibodies elicited by 24 common foods were measured with goat anti-canine IgA and IgM. Low reacting foods were lamb, cow milk, pork, turkey, wheat (lowest) and white-colored fish, whereas high reacting foods were millet, white potato, rice (highest) and salmon. Thus, the novel salivary-based food sensitivity and intolerance test, described previously for canines, also provided a reliable and clinically predictive alternative to food elimination trials, serum-based food allergy testing, and skin patch testing in cats. Manufacturers of commercial cat foods and treats, as well as those making homemade diets and treats for cats, should consider avoiding the more highly reactive foods as determined by the present study.

Prothrombin Time Proficiency Testing: A Robust Grading Method

A robust two-way analysis of variance technique was applied to determine simultaneously the effects of method and thromboplastin on prothrombin time. A new approach to outlier detection for two-way analysis of variance was used. Focusing on the underlying error structure improved the uniformity of the grading procedure in the hematology proficiency testing program of the New York State Department of Health.

The logarithm-transformed scale produced constancy of error variance and resulted in uniformity of the acceptable spread of data. The common variance was lower than that obtained by previous methods and allowed for a narrower acceptable range of reported prothrombin times by reducing the inflated standard deviation, thus improving the efficiency of the grading procedure.

For proficiency testing, no advantage was found in the use of either a common thromboplastin or freeze-dried, coumadinized patient plasmas rather than artificially depleted commercial plasmas, except for special purposes.

Non-Thrombogenicity of Clean Glass Revealed by Native Whole Blood Assay in Bead Columns

The previously described native whole blood assay for materials in solution or suspension has been adapted to materials in a bead column configuration. These experiments showed that the glass itself accounts for little or none of the high blood-reactivity observed with conventional glass bead columns. Columns composed solely of soft glass that was “cleaned” by heat treatment (500-595° C 18 hr, electric oven) were benign toward flowing native whole blood for all variables measured (platelet count and platelet-free plasma [C14]-serotonin content, platelet factor 3 and factor XII activities, and recalcification time) with the standard contact protocol. In addition, the effluent successfully maintained perfusion of the isolated kidney, a measure of the ability of platelets to support vascular integrity. Prolonged (30 min) normothermic contact with titrated whole blood increased the subsequent reactivity of initially clean glass toward whole blood albeit to a level much less than that of conventional glass bead columns.

A Native Whole Blood Assay for Blood-Materials Interaction

A convenient, accurate, and reproducible method was developed and characterized to test the effects of particulate solids and soluble agents on native whole blood. The effects of citrate anticoagulation and of variation in flow and column parameters were characterized by ancillary experiments. The study utilized a relatively homogeneous strain of large rabbits that had received intravenous [C14]-serotonin as a platelet radiolabel. The assay included a 4 min contact time of either the test sample or saline control with freshly drawn arterial blood and was followed by a series of hemostatic measurements, both before and after passage of the blood through a standard 1 g glass bead column. Changes induced by soluble (ADP, ellagic acid, aspirin) and particulate (collagen) agents in the reactivity of this blood to the subsequent challenge of a large area of reactive surface revealed reproducible quantitative effects on platelets and clotting. Generally comparable results were obtained with native whole human blood when the glass bead surface was adjusted (2 g) for the species difference in coagulability and platelet reactivity.

Spontaneous Atrial Thrombosis in Aged Syrian Hamsters II. Hemostasis

Coagulation and fibrinolysis were studied in a colony of aged Syrian hamsters with spontaneous atrial thrombosis, and the results are consistent with concomitant consumption coagulopathy. In comparison to age- and sex-matched hamsters from the same colony, those with atrial thrombi had significantly prolonged prothrombin and partial thromboplastin times, reduced levels of factors II, VII, VIII and X activities and plasminogen; and concentrations of fibrinogen-fibrin split products in excess of 80 μg/ml. Hematocrits of the thrombosed animals were significantly decreased, total plasma proteins were increased, leukocyte counts were within normal limits, and platelet counts were about half those of the controls. Thrombosed hamsters had significantly reduced plasma albumin content, increased γ1-, β-, and γ-globulins, and reduced A/G ratios.

Aged sick hamsters without demonstrable thrombi also had reduced coagulation and fibrinolytic activities and platelet counts, but their fibrinogen levels were markedly elevated, and fibrinogen-fibrin split products were either absent or present in trace amounts. This suggests an earlier and/or less acute form of the thrombotic process.

Characterization of the Fawn-Hooded Rat as a Model for Hemostatic Studies

A large colony of fawn-hooded (FH) rats, comprising five original families and six generations of their progeny, was developed for genetic and comparative studies of their bleeding tendency. The characteristics of the bleeding diathesis in these rats are similar to those originally reported in related rats by Tschopp and Zucker. FH rats have normal clot retraction, ADP-induced platelet aggregation and platelet ADP ; variable aggregation with collagen; minimal aggregation with adrenaline and cobra venom factor; and reduced platelet ATP, ATP/ADP ratio, serotonin content and 14C-serotonin release. In comparison to age- and sex-matched Wistar rats, FH rats have significantly prolonged partial thromboplastin time, shortened Russell’s viper venom time and increased factor X and XI levels. Other coagulation screening tests and specific assays for fibrinogen, plasminogen and factors VII, VIII and IX were normal. Some age- and sex-related differences in coagulation and other parameters were observed within each rat strain. Plasma proteins, glycoproteins and cerulo-plasmin (copper oxidase activity) showed no abnormalities, nor did initial studies of immunoglobulins and complement. However, FH rats have significantly lower glucose and higher cholesterol levels than comparable Wistar rats.

Effects of Reagent and Instrument on Prothrombin Times, Activated Partial Thromboplastin Times and Patient/Control Ratios

Activated partial thromboplastin times accumulated from two proficiency testing surveys were analyzed to determine simultaneously the effects of the method and reagent used. Prothrombin time results were reevaluated concomitantly for comparison.

A robust two-way analysis of variance was applied to determine the effect of method and reagent on APTT results. The effect of the reagent and method on the ratio of abnormal to normal plasma clotting times was determined. We found a substantial difference in ratios for the PT using different reagents on the same instrument. There was an even larger effect of reagents on APTT ratios.

Our finding of substantial reagent effects for the PT and APTT clearly support the need for standardization. We found standardization to be feasible only for the PT, and only if applied in a form consistent with the inherent error structure of the data. For the APTT the present methodology and plasma samples did not achieve consistent standardization.

Remineralization of early caries by chewing sugar-free gum: a clinical study using quantitative light-induced fluorescence

PURPOSE

To determine whether sugar-free gum can provide remineralization and caries control of active enamel caries lesions compared to baseline (before gum chewing) and to a no-gum group, following daily chewing for 12 weeks by school children; to determine whether chewing frequency can affect the extent of remineralization.

METHOD

A pragmatic cluster-randomized controlled clinical trial with schools as the unit of randomization was employed. Three schools in Chengdu, PR China comprised the clusters. The study was approved by the Internal Review Board of Sichuan University. 177 school children, 8-13 years old, with at least one visible white-spot lesion were enrolled in the study. Each of the three clusters was randomly assigned to one of three groups: (1) no gum; (2) chew 2 pieces of sugar-free gum for 20 minutes, 3x per day; (3) chew 2 pieces of sugar-free gum for 12 minutes, 5x per day. White-spot lesions were examined by quantitative light-induced fluorescence (QLF) at baseline and after 4, 8, and 12 weeks of treatment.

RESULTS

155 subjects completed the study. Of them, the mean values of fluorescence loss at baseline were 9.52, 9.83 and 9.17 for no-gum group, 3x per day group and 5x per day group, respectively. For the area, the mean values at baseline were 2.52, 2.61 and 2.57 mm2 for no-gum group, 3x per day group and 5x per day group, respectively. For AQ, the mean values at baseline were -27.91, -28.29 and -29.67 for no-gum group, 3x per day group and 5x per day group, respectively. To adjust for differences in groups at baseline, ANCOVA was used. After 12-weeks, for all QLF metrics, the absolute values of 5x per day group were the lowest and the no gum group was the highest; the differences among three groups were statistically significant (P < 0.05). For AQ, which was accepted as the most useful metrics of QLF system, the adjusted mean values at 12 weeks were -26.35, -19.81 and -17.58 for no-gum group, 3x per day group and 5x per day group, respectively. There were significant differences between groups.

Association of canine hypothyroidism with a common major histocompatibility complex DLA class II allele

Dogs exhibit a range of immune-mediated conditions including a lymphocytic thyroiditis which has many similarities to Hashimoto's thyroiditis in man. We have recently reported an association in Doberman Pinschers between canine hypothyroidism and a rare DLA class II haplotype that contains the DLA-DQA1*00101 allele. We now report a further series of 173 hypothyroid dogs in a range of breeds where a significant association with DLA-DQA1*00101 is shown.

Clinical use of serum parvovirus and distemper virus antibody titers for determining revaccination strategies in healthy dogs

OBJECTIVE

To assess whether serum canine parvovirus (CPV) and canine distemper virus (CDV) antibody titers can be used to determine revaccination protocols in healthy dogs.

DESIGN

Case series.

ANIMALS

1,441 dogs between 6 weeks and 17 years old.

PROCEDURE

CPV and CDV antibody titers in serum samples submitted to a commercial diagnostic laboratory were measured by use of indirect fluorescent antibody (IFA) tests. On the basis of parallel measurements of CPV and CDV serum antibody titers in 61 paired serum samples determined by use of hemagglutination inhibition and serum neutralization methods, respectively, we considered titers > or = 1:5 (IFA test) indicative of an adequate antibody response.

RESULTS

Age, breed, and sex were not significantly associated with adequate CPV- or CDV-specific antibody responses. Of 1,441 dogs, 1,370 (95.1%) had adequate and 71 (4.9%) had inadequate antibody responses to CPV, whereas 1,346 of 1,379 (97.6%) dogs had adequate and 33 (2.4%) had inadequate responses to CDV. Vaccination histories were available for 468 dogs (468 for CPV, 457 for CDV). Interval between last vaccination and antibody measurement was 1 to 2 years for the majority (281/468; 60.0%) of dogs and 2 to 7 years for 142 of 468 (30.3%) dogs. Interval was < 1 year in only 45 of 468 (9.6%) dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

The high prevalence of adequate antibody responses (CPV, 95.1%; CDV, 97.6%) in this large population of dogs suggests that annual revaccination against CPV and CDV may not be necessary.

Correlation of electrical and contractile activities of the cricopharyngeus muscle in the cat

We correlated the electrical and contractile activities of the cricopharyngeus (CP) to better understand the function of the CP and the upper esophageal sphincter (UES). In 40 decerebrate cats, we recorded resting and active tension of the CP and CP force and electromyographic (EMG) activity simultaneously during electrical stimulation of the pharyngoesophageal (PE) nerve, esophageal distension, or swallowing. In six intact cats, the change in diameter of the UES during food swallows was determined in two planes using videofluoroscopy. We found that resting tension of the CP developed quickly with stretch, and the strain-energy function, y = 6.5e3.4(z-1), fit (r = 0.94 +/- 0.06) this relationship. Active tension peaked at 1.68 +/- 0.03 times resting length, which is greater than the maximum distension during swallowing. Activation and relaxation of the CP occurred in approximately 50 and 120 ms, respectively. PE nerve stimulation bilaterally caused a force equal to approximately 90% of the summed force generated by separate stimulation of each PE nerve. The magnitude of the EMG response of the contralateral CP was approximately 18% of the ipsilateral response to unilateral PE nerve stimulation. We conclude that the CP exhibits tension throughout its physiological range of stretch. The CP functions more like a bilateral than a single contiguous muscle, and more like cardiac than striated muscle with regard to its passive elastic properties.

Hemophilia B (factor IX deficiency) in a family of German shepherd dogs

Three male German Shepherd Dog pups were treated for vaccination-induced hematomas. Coagulation tests in 2 of these pups revealed markedly prolonged activated partial thromboplastin times, whereas specific coagulation factor tests revealed severe deficiency of factor IX activity. Investigation of the pedigree supported a sex-linked pattern of inheritance and a distant relationship to a pup found to have hemophilia B 7 years earlier. Dogs in the pedigree had variable manifestations of bleeding, including hematomas, deep muscle bleeding, profuse bloody diarrhea, and sudden neonatal deaths. von Willebrand's disease was concurrently detected in several dogs in the pedigree, and may have contributed to the bleeding tendency in some dogs. Medical management of 2 of the 3 pups included transfusion of fresh whole blood, canine fresh-frozen plasma, and canine plasma cryosupernatant, as indicated, and cage rest. Two pups were euthanatized because of the severity of recurrent bleeding episodes. A third dog remains alive, but requires periodic infusions of blood product to maintain hemostasis.

Factor XI deficiency in Kerry Blue Terriers

A 9-year-old female Kerry Blue Terrier with postoperative hemorrhage and prolonged activated partial thromboplastin and activated clotting times was determined to have factor XI deficiency. Transfusions of fresh-frozen plasma given on 4 consecutive days transiently returned the values for activated clotting time and plasma factor XI activity to within reference range limits and controlled the hemorrhage. Analysis of data from 10 other factor XI-deficient Kerry Blue Terriers with a tendency for mild posttraumatic or postoperative bleeding was suggestive of an autosomal mode of inheritance, with a mild tendency for posttraumatic or postoperative bleeding in homozygous and heterozygous dogs. Factor XI deficiency is the only contact phase protein defect that causes a bleeding disorder in animals, which can be explained by the fact that thrombin is more efficient than factor XIIa in activating factor XI. Factor XIa plays a key role in sustaining coagulation.

Characterization and quantification of a pharyngo-UES contractile reflex in cats

We characterized and quantified a reflex from the pharyngeal mucosa to the upper esophageal sphincter (UES). Seventeen cats were decerebrated, and the pharynx was exposed by opening the cricothyroid ligament. UES motor activity was assessed by recording electromyographic (EMG) activity from the pharyngeal constrictors, i.e., the thyropharyngeus (TP) and cricopharyngeus (CP). The pharyngeal mucosa was stimulated by touch or pressure. Both stimuli activated contraction of the CP primarily when applied to the naso-, laryngo-, or hypopharynx, but pressure was more effective. The anteromedial portion of the hypopharynx was the most sensitive zone, but there was no strong stimulus-response relationship. The reflex response to a 1-s stimulus occurred at a delay of 0.46 +/- 0.06 s and lasted 4.5 +/- 0.5 s. This pharyngo-UES reflex was blocked by anesthesia of the mucosa or transection of the glossopharyngeal or pharyngoesophageal nerves but not the vagus nerves. In contrast, the esophago-UES contractile reflex was not blocked by anesthesia of the pharyngeal mucosa or transection of the glossopharyngeal nerves but was blocked by transection of either the vagus or pharyngoesophageal nerves. We concluded that the pharyngo-UES contractile reflex was activated by pharyngeal mucosal mechanoreceptors whose afferent limb was the glossopharyngeal nerve and whose efferent limb was the pharyngoesophageal branch of the vagus nerve.

Analyses of normal and abnormal esophageal transport using computer simulations

Mathematical modeling and computer simulations are combined with concurrent manometric and videofluoroscopic data to analyze the contractile behavior of the esophageal wall during normal and abnormal esophageal bolus transport. The study focuses on axial variations in intraluminal pressure in relationship to deformations of the esophageal wall during the transport process. Four case studies of esophageal bolus transport described by Kahrilas et al. (Gastroenterology 94: 73-80, 1988), one normal and three abnormal, are analyzed in detail by capturing the major elements of both the videofluoroscopic and concurrent manometric data in the mathematical model. In all cases a strong correlation between the deformations of the luminal wall and the axial variations of intraluminal pressure is observed. Simulation of normal bolus transport shows that, whereas only gentle variations in intrabolus pressure occur in the main body of the bolus due to weak frictional forces there, large frictional forces force a rapid rise in pressure near the bolus tail induced by circular muscle squeeze. Of particular interest is the analysis of incomplete clearance of bolus fluid in the aortic arch region. The only physically correct model consistent both with the videofluoroscopic and the manometric data implies the existence of two separate contraction waves, one above and one below the transition zone.(ABSTRACT TRUNCATED AT 250 WORDS)

Coordination between respiration and swallowing: respiratory phase relationships and temporal integration

The coordination of breathing and swallowing was studied in 13 young healthy adult subjects during the administration of graduated volumes of water (3, 10, and 20 ml). Simultaneous submental electromyography, respiratory plethysmography, and fiber-optic endoscopy revealed a well-timed pattern between physiological respiratory events and related swallowing events. Expiration was the phase of respiration that was most closely associated with deglutition. Respiration was usually maintained at the onset of deglutition and halted before the onset of laryngeal elevation. The apneic interval was approximately 1 s for the 3-, 10-, and 20-ml boluses. A large-volume (100-ml) straw swallow resulted in variable respiration-swallowing patterns and in statistically significant differences (P < 0.01) in the duration of apneic pause and laryngeal excursion. The expiratory phase of respiration resumed nearly 0.50 s before the completion of swallowing. Clinical implications of the findings are addressed and related to aspiration and pulmonary complications in dysphagic patients.

Factor IX deficiency (hemophilia B) in a family of British shorthair cats

This report describes the clinical findings of a British shorthair cat with hemophilia B, the family pedigree surrounding the case, and how this disorder can be perpetuated in rare breeds of cats that may be inbred by necessity. Young cats with histories of bleeding episodes following elective or other surgical procedures, periodic shifting lamenesses, or the development of subcutaneous hematomas should be suspect for an inherited coagulation disorder. Hemophilia A (factor VIII deficiency) or hemophilia B (factor IX deficiency) are the most likely causes, although other inherited bleeding disorders also have been recognized in cats.

Pharyngeal, esophageal, and proximal gastric responses associated with vomiting

The motor activities of the pharynx, esophagus, and proximal stomach associated with vomiting were characterized and quantified in 25 awake chronically instrumented dogs. These motor events were correlated temporally with motor responses of the gastrointestinal and respiratory tracts. Vomiting was stimulated by apomorphine or UK-14304, and motor activities of striated and smooth muscles were recorded by electromyography and strain-gauge transducers, respectively. We found responses that began 1) before retching: increased swallow frequency, relaxation of the lower esophageal sphincter (LES) and proximal stomach, and tonic contraction of the cricopharyngeus and cervical esophagus; 2) during retching: rhythmic relaxation and contraction of the pharynx and cervical esophagus 180 degrees out of phase with retching; and 3) during vomitus expulsion: relaxation of the pharynx and cervical esophagus but strong contraction of the geniohyoideus and a retrograde contraction of the cervical esophagus and pharynx. The increased pharyngoesophageal tone occurred in an all-or-none fashion independent of vomiting or the gastrointestinal correlates of vomiting. Cervical vagal blockade increased swallow frequency but did not alter the other pharyngoesophageal responses associated with vomiting. We concluded that the motor events of the pharynx and esophagus play a significant role in gastrooral evacuation during vomiting and that these motor events (except LES relaxation) are not controlled by subnodose vagal pathways.

Prevention of barium aspiration during videofluoroscopic swallowing studies: value of change in posture

OBJECTIVE

We investigated the frequency with which changes in the position of a patient's head or body eliminated aspiration of liquid barium during videofluoroscopic swallowing studies in patients with oropharyngeal dysphagia. We also studied factors that influenced the effect of posture on aspiration.

SUBJECTS AND METHODS

The study group comprised 165 patients consecutively referred for videofluoroscopic examination of the oropharyngeal stages of swallowing in whom aspiration of barium occurred while swallowing 1, 3, 5, or 10 ml of thin liquid barium or drinking barium from a cup. When aspiration occurred, the patient changed to one of five postures (chin down, chin up, head rotated, head tilted, and lying down), selected on the basis of the specific swallowing abnormality causing the aspiration.

RESULTS

Changes in head or body position eliminated aspiration of at least one bolus of barium in 127 (77%) of the 165 patients, and of all four boluses plus drinking barium from a cup in 41 patients (25%). Postural changes were less beneficial in preventing aspiration in patients with substantial language or cognitive defects or restricted head movement.

CONCLUSIONS

Postural techniques can eliminate aspiration of barium of at least small volumes in most patients. Expansion of the oropharyngeal swallowing study to include the effect of various postures can be done with minimal risk of increased aspiration.

Effect of age and bolus variables on the coordination of the glottis and upper esophageal sphincter during swallowing

We studied 1) the effect of age and bolus variables on a) the coordination of deglutitive vocal cord adduction and upper esophageal sphincter (UES) relaxation and b) the duration of deglutitive vocal cord adduction; 2) the effect of the presence of a manometric catheter across the UES on the deglutitive glottal function; and 3) the temporal relationship between deglutitive vocal cord closure and swallow-induced apnea. We studied 10 young (23 +/- 2 yr) and 10 healthy elderly (73 +/- 2 yr) volunteers by concurrent videoendoscopy, UES manometry, respirography, and submental surface electromyography. In both groups the onset of vocal cord adduction preceded the onset of UES relaxation, deglutitive apnea, and submental electromyogram swallowing signal. In both groups, bolus volume and temperature did not have any significant effect on the duration of deglutitive vocal cord adduction. In both young and elderly volunteers, water swallows, compared with dry swallows, significantly shortened the interval between the onset of deglutitive vocal cord adduction and the onset of UES relaxation. In conclusion, coordination between deglutitive glottal and UES function, as well as the duration of deglutitive vocal cord adduction, is preserved in the elderly. Bolus volume and temperature do not have a modulatory effect on the duration of vocal cord closure, but water swallow shortens the interval between the onset of glottal closure and UES relaxation. This shortened interval may contribute to the safety of the airway during swallowing of liquid volumes.

Normal laryngeal valving patterns during three breath-hold maneuvers: a pilot investigation

Synchronized videonasendoscopy and respiratory recordings were conducted in six healthy male subjects to evaluate activity of the arytenoid cartilages, true vocal folds, false vocal folds, and epiglottis during repeated trials of three breath-hold maneuvers: EASY hold, INHALE HARD hold, and INHALE/EXHALE HARD hold. Five of the six subjects demonstrated maximal laryngeal valving on the HARD breath-hold conditions. One subject showed maximal laryngeal valving on the EASY hold condition, and rarely demonstrated any medial displacement or contact of the laryngeal valves on either effortful breath-hold maneuver. Arytenoid approximation and true vocal fold closure were produced consistently by the majority of subjects on all breath-hold maneuvers, but false vocal fold approximation and anterior arytenoid tilting were accomplished by the majority of subjects only during the effortful breath-hold conditions. Intratrial and intersubject variation indicated that presence or degree of laryngeal valving cannot be assumed during a breath-hold maneuver. We conclude that videonasendoscopy has merit in assessing a patient's laryngeal valving ability and progress in effectively using a breath-hold maneuver for safe swallowing function.

Effect of aging and bolus variables on pharyngeal and upper esophageal sphincter motor function

Effect of aging, bolus volume, temperature, and consistency on the pharyngeal peristalsis, as well as the effect of aging on the upper esophageal sphincter (UES) resting pressure and its response to esophageal distension by air and balloon, were studied in 14 young and 12 healthy elderly volunteers. In both age groups there was no significant volume or temperature effect on amplitude, duration, or velocity of the pharyngeal peristalsis. Compared with water swallows, mashed potato swallows resulted in a significant increase in the amplitude and duration of the hypopharyngeal peristaltic pressure wave (P < 0.05). For water swallows, the amplitude and duration of the peristaltic pressure wave in the hypopharynx were significantly increased in the elderly compared with the young group (P < 0.01). UES resting pressure in the elderly measured 43 +/- 5 (SE) mmHg and was significantly less than that of the young (71 +/- 8 mmHg; P < 0.01). Magnitude of the UES pressure decrease because of esophageal distension by air, as well as magnitude of its pressure increase because of esophageal balloon distension, was similar among young and elderly. 1) Contrary to common expectations, the parameters of the pharyngeal peristaltic pressure wave do not deteriorate in the elderly in their seventh and eighth decade. 2) Compared with the young, hypopharyngeal pressure wave amplitude and duration are significantly increased in the elderly. This increase could be caused by an adaptation response to a pharyngeal outflow compromise. 3) Pharyngeal peristaltic pressure wave amplitude and duration, but not its velocity, are modulated by the bolus consistency. This modulatory mechanism is preserved in the elderly. 4) Although UES resting pressure is significantly decreased in the elderly, its pressure response to esophageal distension by air and balloon is preserved.