1,721,081 research outputs found
EVALUATION OF ELECTROMYOGRAPHIC ACTIVITY OF THYROHYOIDEUS (TH) MUSCLE AND ULTRASONOGRAPHIC ASSESSMENT OF THE POSITION OF THE HYOID APPARATUS AT REST AND THEIR POSSIBLE ROLE IN THE PATHOGENESIS OF INTERMITTENT DORSAL DISPLACEMENT OF THE SOFT PALATE (DDSP) IN RACEHORSES.
Full text linkIntroduction
Dorsal displacement of the soft palate (DDSP) is one of the most common intermittent dysfunctions of the nasopharynx in racehorses. The DDSP etiopathogenesis is, still today, not clearly understood. Recently was induced DDSP in horses during exercise after bilateral resection of thyrohyoideus (TH) muscles. DDSP was also correlated to a more ventral position of the basihyoid bone evaluated using ultrasonographic scan of the laryngohyoid region.
Objectives
The purpose of the present work is to investigate TH activity at rest in horses affected with DDSP using surface electromyography (EMG) and correlate the results with the position of hyoid apparatus using ultrasonographic scan of the laringohyoid region.
Materials and method
12 racehorses (10 Standardbreds and 2 Thoroughbreds), referred with history of poor performance ranged in age between 2 and 4 years (mean age 3.1 ± 0,7 years) with a mean body weight of 468,9 ± 52,3 kg. All horses underwent a thorough diagnostic protocol, including examination at rest and during exercise of different body systems, ultrasonographic scan of the laryngeal-hyoid portion and EMG evaluation of TH muscles. Exercise tests were realized using an high-speed treadmill (SATO-I, Sweden) and all the exercise tests was performed using a standardized protocol. On day 4 the treadmill endoscopy using a videoendoscope (Stortz®-Germany) held in position with Velcro straps was performed. After videoendoscopy of the upper respiratory tract on treadmill horses were classified into one of two groups based: DDSP when the caudal border of the epiglottis was situated dorsal to the epiglottis for a minimum of 8 s and horses without DDSP if DDSP wasn’ t discovered..
Ultrasonographic scan of the laryngohyoid region comprised two acoustic windows the rostroventral and the midventral, scanned in longitudinal and transverse planes. Using the electronic caliper of the machine were measured the depth of the basihyoid bone at the base of lingual process, the depth of the caudal aspect of the basihyoid bone, the depth of the rostral aspect of the thyroid cartilage, and the distance from the caudal aspect of the basihyoid bone to the rostral aspect of the thyroid cartilage.
The EMG activity of the TH muscles was evaluated at rest with surface electrodes and a ground obtained with a subcutaneous needle electrode. The was applied on both sides at the level of the topographic area corresponding to the TH muscle, which was clipped and cleaned with alcohol. TH activity was measured during deglutition obtained following administration of 50 ml of water in the mouth using a 50 ml syringe. This operation was repeated at least five time for each side and every activity connected with deglutition recorded. Electromyographic signals were processed and analyzed and the mean electrical activity (MEA) of the muscles was evaluated. The statistical analysis of the results was made comparing the two groups, horses with DDSP (wDDSP) and without DDSP (nDDSP), considering all the measures of the laryngohyoid position, the MEA of TH muscle on the left side (MEAl), the MEA of TH muscle on the right side (MEAr) and mean MEA obtained from the two sides (MEArl) for every horse. The analysis was realized with a statistical software SIGMAPlot®12.
Using SIGMAPlot®12 was realized a Shapiro-Wilk test to assess the normal distribution of the data followed by a t-test to compare every data between the group wDDSP and nDDSP. Next a Pearson Product Moment Correlation was used to evaluate the correlation between the different data in nDDSP and wDDSP groups. Finally the relationship between age, sex and weight on MEAr, MEAl, MEArl and laringohyoid measures was analyzed using a linear regression test. For all statistical analysis, values were considered significant at P ≤ 0.05.
Results
The videoendoscopy of the upper airways during exercise on a high speed treadmill permitted to diagnose DDSP in 5 horses (4 standardbred and 1 Throughbred), pharyngeal collapse in 1 horse, pharyngeal collapse associated with axial deviation of the aryepiglottic folds (ADAF) in 2 horses and no dynamic abnormality of the upper respiratory tract (URT) in 4 horses. The statistical analysys, using Pearson Product Moment Correlation test, showed only in the wDDSP group some correlation between the data analyzed. A strong correlation (p. 0,0019) was found between the depth of the basihyoid bone at the base of lingual process and depth of the rostral aspect of the thyroid cartilage on the midventral window. Another strong correlation (p. 0,0092) was found between depth of the rostral aspect of the thyroid cartilage and depth of the caudal aspect of the basihyoid bone in the midventral window. Finally, strong correlations were found between MEAr and MEAl (p. 0,0039), MEAr and MEArl (p. 0,0005) and MEAl and MEArl (p. 0,0004). No other difference or correlation were found.
Discussion and conclusion:
Our results didn’t identify any statistical difference in laringohyoid measures between nDDSP and wDDSP groups. Anyway, in wDDSP group we found a high correlation between some ultrasonographic measures obtained confirming the importance of the connection between hyoid apparatus and larynx in DDSP patients. We didn’t find any difference between MEA in nDDSP and wDDSP patients at rest. Probably, our results are directly conditioned by the type of test realized. Probably more information regarding the activity of TH muscles could be obtained with the evaluation during exercise. The results obtained provide informations regarding the pathogenesis of intermittent DDSP. Future results obtained with the evaluation of the same parameters under exercise conditions may aid the clinician to identify the actual causes for DDSP
Creatine kinase reference intervals at rest and after maximal exercise in Standardbred racehorses
No full textDue to the high variability of data drawn from the literature, the aim of this study was to evaluate the effects of exercise on serum creatine kinase (CK) activity and to determine CK reference intervals (RIs) at rest and post-exercise in Standardbred racehorses. Data concerning history, physical examination, laboratory evaluation and ECG were collected retrospectively from a population of 258 Standardbreds in training that underwent incremental maximal treadmill exercise. Subjects with alterations potentially influencing CK were excluded. A reference sample of 194 healthy horses was eventually selected. Blood samples were collected 1 h before and 6 h post-exercise and analysed via a spectrophotometric method. Values were compared by Wilcoxon test for paired samples. The effect of age and sex was evaluated by Kruskal-Wallis and Dunn’s post-test (P<0.05). RIs were determined following Clinical and Laboratory Standard Institute (CLSI) guidelines, approved by the American Society for Veterinary Clinical Pathology. Using a macroinstruction set for Microsoft Excel (RefValAdv), RIs were determined with a non-parametric method. A significant increase (P<0.0001) in CK activity post-exercise was observed. Partition by sex and age did not show any statistical difference, either at rest or post-exercise. In determination of RIs no outliers were identified. RIs ranged from 25-394 IU/l at rest and from 44-734 IU/l post-exercise. To our knowledge, this is the first study considering CK post-exercise RIs in racehorses using CLSI’s guidelines and specific CK-related exclusion criteria. These RIs could be useful to discriminate between physiological and pathological post-exercise serum CK increases
Determinazione della concentrazione sierica di Troponina cardiaca I in cavalli trottatori prima e dopo esercizio massimale su treadmill
No full textLa determinazione della concentrazione sierica o plasmatica della Troponina cardiaca I è stata introdotta anche in medicina veterinaria quale marker di danno miocardico. Scopo del lavoro è quello di determinare la concentrazione sierica di cTnI in una popolazione omogenea di cavalli trottatori da corsa in allenamento e valutare le possibili variazioni di dosaggio di cTnI a riposo e dopo esercizio massimale.The evaluation of the cardiac Troponin I (cTnI) serum or plasma concentration was recently introduced in the veterinary medicine as a sensible and specific marker of myocardial damage. In the literature are available data regarding the cTnI normal value in horses at rest and after exercise, in athletic and in pastured horses, as well as the identification of the main cardiac diseases that may cause an increased cTnI serum concentration. Aim of the present paper is to determine the cTnI serum concentration in a homogeneous population of standardbred horses in training and to evaluate the significance of different cTnI concentrations before and after strenuous exercise. The mean cTnI serum value at rest was 0.01 ng/ml (range 0-0.05 ng/ml); the mean cTnI serum value 6 hours after strenuous exercise on treadmill was 0.09 ng/ml (range 0.01-0.36 ng/ml); the mean cTnI serum value 24 hours after strenuous exercise on treadmill was 0.05 ng/ml (range 0-0.22 ng/ml). There were no statistically significant differences between cTnI serum concentrations obtained before, 6 hours and 24 hours after the treadmill test, although an increased cTnI serum concentration was observed in horses 6 hours after treadmill exercise. Furthermore, no statistically significant correlation was found between cTnI concentrations before and after exercise and exercise intensity, sex and age of the horses
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
