Whiplash-Associated Dysphagia and Dysphonia: A Scoping Review.

Swallowing and voice complaints after a whiplash injury have been observed and reported in several studies; however, variability in study design complicates current understanding of whether dysphagia and dysphonia should be recognised as potential adverse outcomes. A scoping review was conducted across six databases from 1950 to March 2019. A total of 18 studies were included for review. Data regarding study purpose, design, outcome measures, participant characteristics and outcomes reported were extracted. Level of evidence (LOE) was assessed by the American Speech-Language Language Association (ASHA)'s LOE system. All studies were exploratory, with 68% rated as poor (< 3) on quality ratings. Nearly half (n = 6) were single case reports. Only three studies investigated some type of swallow-related outcome specifically within the study aim/s. Incidence of swallow-related problems ranged from 2 to 29%, with unspecified complaints of "swallowing difficulty", "dysphagia" and fatigue and pain whilst chewing reported. Neither swallowing biomechanics nor the underlying pathophysiology of swallow or voice complaints was investigated in any study. Four case studies presented post-whiplash voice complaints; two of which described loss of pitch range. Others described hoarseness, loss of control and weak phonation. Most studies only mentioned swallow- or voice-related deficits when reporting a wider set of post-injury symptomatology and six did not describe the outcome measure used to identify the swallow and voice-related problems reported. The existing literature is limited and of low quality, contributing to an unclear picture of the true incidence and underlying mechanisms of whiplash-related dysphagia and dysphonia.

Cholesterol balance and fecal neutral steroid and bile acid excretion in normal men fed dietary fats of different fatty acid composition.

Six normal men were fed formula diets containing either highly saturated fat (cocoa butter, iodine value 32) or polyunsaturated fat (corn oil, iodine value 125). The sterol balance technique was used to compare the changes in serum cholesterol concentration with the excretion of fecal steroids. The method used for the analysis of fecal steroids was chemical, with a final identification and quantification by gas-liquid chromatography. It was confirmed that the chemical method for fecal steroid analysis was accurate and reproducible. The three dietary periods were each 3 wk in length. In sequence, cocoa butter (period I), corn oil, and cocoa butter (period III) were fed at 40% of the total calories. All diets were cholesterol free, contained similar amounts of plant sterols, and were identical in other nutrients. Corn oil had a hypocholesterolemic effect. Mean serum cholesterol concentrations were 222 mg/100 ml (cocoa butter, period I), 177 during corn oil, and 225 after the return to cocoa butter. Individual fecal steroids were determined from stools pooled for 7 days. Both neutral steroids and bile acids were altered significantly by dietary polyunsaturated fat. The change in bile acid excretion was considerably greater than the change in neutral steroids. Corn oil caused a greater fecal excretion of both deoxycholic and lithocholic acids. The total mean excretion (milligrams per day) of fecal steroids was 709 for cocoa butter (period I), 915 for corn oil, and 629 for the second cocoa butter period. The enhanced total fecal steroid excretion by the polyunsaturated fat of corn oil created a negative cholesterol balance vis-à-vis the saturated fat of cocoa butter. The hypocholesterolemic effect of polyunsaturated fat was associated with total fecal sterol excretion twice greater than the amount of cholesterol calculated to leave the plasma. This finding suggested possible loss of cholesterol from the tissues as well.

Conformations of myosin subfragment 1 ATPase intermediates from neutron and X-ray scattering.

In order to elucidate the structural changes that occur during the hydrolysis of ATP by myosin, low-angle neutron and X-ray scattering have been used to investigate the shape of the myosin head (S1) with various bound nucleotides and nucleotide analogs. It was found that the radius of gyration (Rg) of S1.MgADP.AlF4 and of S1MgADP.Vi were similar and significantly smaller (approximately 3%) than the similar Rg values of nucleotide-free S1, S1.MgADP and S1.MgADP.BeFx. In addition, S1 in the presence of MgATP, which is predominantly in the S1.MgADP.Pi state under the experimental conditions employed, showed a change in Rg comparable with that of S1.MgADP.AlF4 and S1.MgADP.Vi. The results obtained here with BeFx and AlF4 are in close harmony with crystallographic results on truncated S1 bearing MgADP.BeFx and MgADP.AlF4. A. Fisher and co-workers have postulated that these two systems, which exhibit some structural differences, represent the pre-hydrolysis state and the transition state of ATP hydrolysis, respectively. It was postulated that this structural difference might alter the orientation of the light-chain-binding domain (tail) of intact S1 relative to the remainder of the molecule. Since this orientation is the major determinant of the Rg of S1, the current data support the hypothesis that a unitary large-scale conformational cocking of S1 for subsequent force production occurs just before or during ATP hydrolysis. Modeling changes in Rg by rigid-body rotations indicates that the longitudinal component of the force-producing throw is likely to be less than 6 nm.

Comparison of the structure of myosin subfragment 1 bound to actin and free in solution. A neutron scattering study using actin made "invisible" by deuteration.

The structure of subfragment 1 (S1) bound to F-actin has been compared to the structure of free S1 using neutron scattering. The F-actin was rendered "invisible" to neutrons by selective deuteration and solvent contrast matching. Highly deuterated actin was purified from the slime mold Dictyostelium discoideum, which was fed deuterated Escherichia coli. The properties of this actin were found to be similar to those of protonated actin. The neutron-scattering pattern of S1 bound to this "invisible" actin was compared to that of free S1. At near-physiological ionic strength, a strong interference effect was observed, which arose from pairs of S1 molecules cross-linking actin filaments. However, at low ionic strength the only differences that could be observed were attributed to interference effects between neutrons scattered from S1s bound randomly to equivalent sites on an actin filament. These effects became negligible as the fraction of actin sites occupied by S1 approached zero. Thus, we conclude that the scattering by S1 attached to F-actin is identical with that of free S1, to a resolution of about 2.5 nm. The difference in apparent radii of gyration is less than 0.05 nm. Modeling calculations have been carried out to determine the sensitivity of neutron scattering to possible S1 deformations. The calculations showed that deformations of the structure of S1 that are large enough ultimately to produce a powerstroke of 5 nm or greater are only consistent with the data if they involve at most about 20% of the S1 mass. These results restrict the class of plausible models describing force generation in muscle contraction.

The effect of regulatory Ca2+ on the in situ structures of troponin C and troponin I: a neutron scattering study.

The effects of regulatory amounts of Ca2+ on the in situ structures of troponin C (TnC) and troponin I (TnI) in whole troponin have been investigated by neutron scattering. In separate difference experiments, 97% deuterated TnC and TnI within whole troponin were studied +/-Ca2+ in 41.6% 2H2O buffers in which protonated subunits were rendered "invisible". We found that the radius of gyration (Rg) of TnI decreased by approximately 10% upon addition of regulatory Ca2+ indicating that it was significantly more compact in the presence of Ca2+. The apparent cross-sectional radius of gyration (Rc) of TnI increased by about 9% when regulatory Ca2+ was bound to TnC. Modeling studies showed that the high-Q scattering patterns of TnI could be fit by a TnI which consisted of two subdomains: one, a highly oblate ellipsoid of revolution containing about 65% of the mass and the other, a highly prolate ellipsoid of revolution consisting of about 35% of the mass. No other fits could be found with this class of models. Best fits were achieved when the axes of revolution of these ellipsoids were steeply inclined with respect to each other. Ca2+ addition decreased the center of mass separation by about 1.5 nm. The Rg of TnI, its high-Q scattering pattern, and the resultant structure were different from previous results on neutron scattering by TnI in the (+Ca2+) TnC.TnI complex. The Rg of TnC indicated that it was elongate in situ. The Rg of TnC was not sensitive to the Ca2+ occupancy of its regulatory sites. However, Rc increased upon Ca2+ addition in concert with expectations from NMR and crystallography of isolated TnC. The present observations indicate that TnI acts like a molecular switch which is controlled by smaller Ca2+-induced changes in TnC.

Toothbrushing, flossing, and dental visits in relation to socioeconomic characteristics of white American families.

This study investigated the patterns of preventive dental behaviors, including toothbrushing, flossing, and dental visits with respect to certain selected socioeconomic characteristics, namely population density, age, family income, size of family, presence of children, and level of education. The sample of the study included 685 white American families. The results indicated that an individual's preventive dental behavior is related to certain socioeconomic characteristics. The individual who lives in an urban area, possesses a higher income or who has a higher educational level is more apt to take preventive dental actions. Among the socioeconomic variables, family income and educational level made significantly stronger differences with respect to toothbrushing, flossing, and dental visits. Dental visits, compared to other dental activities appeared to be more easily influenced by socioeconomic variables.

A three-year study of obesity and its relationship to high blood pressure in adolescents.

A sample of 356 matched cases were tracked for three years during high school. Measures taken included self-reported behavior and clinical measures of height, weight, skinfold, blood pressure, and body mass index. Data were analyzed by ethnic group, age, and sex groups. Three year (1981-1982 to 1984-1985) trends for students who were overfat, overweight, and obese revealed: a relatively greater proportion of female to male students were overfat as seniors; overweight trends for each of the four groups (ethnic group and gender) were stable over the study period; a sharp increase of obesity trends among black females was observed; and significant positive relationships existed between Percent Ideal Body Weight, skinfold thickness, Body Mass Index, and blood pressure among females of both ethnic groups. The hypothesis that the early onset of obesity is an indicator of obesity in older adolescents was supported. Students classified at risk as freshmen are more likely to remain at risk as seniors.

Knowledge, behavior, and attitudes of sixth-grade students toward family life education.

Although certain exceptions may be noted with respect to sex and type of school, generally lower socioeconomic students obtained lower mean scores on the knowledge and attitude sections of the survey instrument than their counterparts from the higher economic strata. Disadvantaged children from lower socioeconomic levels are reared in an atmosphere hardly conducive to study. Their homes are overcrowded; the children are often hungry, obtain insufficent rest, and possess little interest or motivation for the future--they just live for today. The lower socioeconomic child suffers most when he comes to school. His experiences in living have not prepared him for the demands of the typical school. Shaped by his environment, seeing himself as a person of little worth, he is called upon to conform and communicate. His value system that was bred in deprivation shows sharp contrast to the established "middle class" value system held by the school. Furthermore, disadvantaged children enter school with habits and attitudes that may conflict with many of the traditional modes of teaching. They have had few opportunities to learn the relationship between effort and achievement or to observe that learning has its own reward. Educators have a responsibility to provide the best type of family life education program to meet the needs of all youth. Innovative and challenging ways must be found to make family life education programs relevant to all socioeconomic strata. It would appear essential that educators should possess a thorough knowledge of the economic, social, and cultural conditions that exist in the area in which the educational process is to be conducted.

Estimating recharge distribution by incorporating runoff from mountainous areas in an alluvial basin in the Great Basin region of the southwestern United States.

A method is described to estimate the distribution of ground water recharge within hydrographic basins in the Great Basin region of the southwestern United States on the basis of estimated runoff from high mountainous areas and subsequent infiltration in alluvial fans surrounding the intermontane basins. The procedure involves a combination of Geographic Information System (GIS) analysis, empirical surface-runoff modeling, and water-balance calculations. The method addresses the need to develop and incorporate constraints on the distribution of recharge in regional-scale ground water flow modeling of arid and semiarid environments. The conceptual approach and methodology were developed for Crescent Valley, Nevada. However, the concept and method are generally applicable to any region where excess precipitation in upland areas is conveyed to lower elevations before it infiltrates to recharge the ground water system. Application of the procedure to a ground water flow model of Crescent Valley appears both qualitatively and quantitatively to result in a more accurate representation of actual recharge conditions than might otherwise have been prescribed.