Prevention of excessive exercise-induced adverse effects in rats with Bacillus subtilis BSB3.

AIMS: To characterize efficacy of the Bacillus subtilis BSB3 (BSB3) strain in the prevention of excessive exercise-induced side effects and in maintaining stability of the gut microbiota. METHODS AND RESULTS: Rats were pretreated by oral gavage with B. subtilis BSB3 (BSB3) or with phosphate-buffered saline (PBS) twice a day for 2 days, and were either exposed forced treadmill running or remained sedentary. Histological analysis of intestine, immunofluorescence staining of tight junction (TJ) proteins, serum lipopolysaccharide and intestinal fatty acid-binding protein assay, culture-based analysis and pyrosequencing for the gut microbiota were performed for each rat. Forced running resulted in a substantial decrease in intestinal villi height and total mucosa thickness, the depletion of Paneth cells, an inhibition of TJ proteins expression. Short-term treatment of rats with BSB3 before running prevented these adverse effects. Culture-based analysis of the gut microbiota revealed significant elevation of pathogenic microorganisms only in treadmill-exercised rats pretreated with PBS. High-throughput 16S rRNA gene sequencing also revealed an increase in pathobionts in this group. Preventive treatment of animals with BSB3 resulted in predominance of beneficial bacteria. CONCLUSIONS: BSB3 prevents excessive exercise-associated complications by beneficial modulation of the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study shows a new application of beneficial bacteria for prevention the adverse effects of excessive exercise.

Acetylcholine sensitivity of cat petrosal ganglion neurons.

We investigated if neuronal nicotinic acetylcholine receptors (nAChRs) are localized in chemoreceptor afferent neurons in the cat petrosal ganglion (PG) and if acetylcholine (ACh) excites chemoreceptor afferent neurons. Immunocytochemistry revealed that a majority of PG neurons expressed alpha 4 and/or alpha 7 subunits of neuronal nAChRs, and a part of them were tyrosine hydroxylase positive. Excitability of cultured PG neurons was studied with patch clamp techniques (whole cell configuration). ACh and nicotine evoked both inward and outward currents. The inward current was partially blocked by removal of extracellular calcium and by antagonists for alpha 4 beta 2 (dihydro-beta-erythroidine) or alpha 7 nAChRs (methyllycaconitine). Outward current was blocked by 4-aminopyridine (4-AP) and sometimes by atropine. ACh-induced membrane potential changes were well correlated with ACh-induced currents. Depolarization and hyperpolarization occurred in response to ACh. Occasionally depolarization was followed by a train of action potentials. The results suggest that heterogeneous neuronal nAChRs are widely distributed in both chemoreceptor and other PG neurons. In some neurons nAChRs may be functionally coupled with outward K+ channels. Further studies are required to determine whether chemoreceptor neurons have a distinct distribution pattern of nAChRs and K+ channels.

Presence of nicotinic acetylcholine receptors in cat carotid body afferent system.

With immunocytochemical techniques using a monoclonal antibody for alpha7 subunits of neuronal nicotinic acetylcholine receptors, we have found these subunits to be exclusively expressed in nerve fibers in the carotid body. Double-immunostaining showed that alpha7 subunit-positive nerve endings enveloped tyrosine hydroxylase-positive glomus cells. Some carotid sinus nerve fibers and tyrosine hydroxylase-positive petrosal ganglion neurons also expressed alpha7 subunits. These data support a role for acetylcholine in carotid body neurotransmission.

Lens tropomodulin: developmental expression during differentiation.

Lens epithelial cells undergo a dramatic transformation during the process of differentiation into elongated fiber cells. The membrane-associated actin cytoskeleton is likely to play a critical role in the stabilization and maintenance of the highly elongated fiber cell shape. Tropomodulin is a tropomyosin-binding protein associated with actin filaments in a variety of terminally differentiated cell types where stable actin filament organization is required for cell function. We now present results of studies to determine the temporal expression of tropomodulin in the developing lens. In situ hybridization experiments detected expression of tropomodulin mRNA in the developing mouse lens in elongating cells with a pattern similar to that of the fiber specific beta- and gamma-crystallins. Tropomodulin mRNA expression first appeared around 11.5 days post-coitum in elongating cells in the posterior part of the lens vesicle. At later stages the signal for tropomodulin was present in the elongating cells at the lens equator and in cortical fiber cells; signal was absent from the epithelium. To investigate the possible link between tropomodulin expression and fiber differentiation we used a well-established lens epithelial explant culture system in which fiber differentiation is induced by fibroblast growth factor (FGF). Tropomodulin expression was only observed in FGF-treated explants in conjunction with morphologic changes characteristic of lens fiber cell differentiation. The appearance of tropomodulin during the process of fiber cell differentiation suggests that tropomodulin may be important for stabilization and/or determination of actin filament length.

Association among fitness components, anxiety, and confidence following aerobic training in aquarunning.

The relationship of actual and perceived physiological and physical changes, i.e., VO2max, percent body fat, body weight, and perceived fitness change, to changes in anxiety and confidence were investigated. 15 adults volunteered to participate in an 8-wk. exercise program and 15 adults volunteered to be in a nonexercising control group. Physiological and physical measures (VO2max, percent body fat, body weight) were taken at Week 1 (pretest week) and Week 10 (posttest week) of the program. Each subject completed the Competitive Sport Anxiety Inventory-II prior to and just after the 8-wk. training program. Cognitive and somatic anxiety scores significantly decreased for both groups over the 8-wk. period. Confidence scores did not change for either group. The physiological variable and the physical measures were significantly related to cognitive anxiety, somatic anxiety, or confidence. It appears that both the aquarunning exercise and quiet rest sessions can be associated with anxiety within 8 wk.

Diffractive smoothing of excimer laser ablation using a defocused beam.

OBJECTIVE: To determine if excimer laser myopic ablation with a defocused laser image produces a smoother ablation profile than does focused laser light. METHODS: An ArF excimer laser was used to ablate a 5.00-diopter myopic correction in test blocks using both a contracting and expanding iris aperture. Defocused ablation was performed using a contracting iris aperture by translating the target away from the laser source. A confocal laser scanning microscope was used to analyze the surface smoothness at 55x and 275x magnifications. RESULTS: The confocal laser scanning micrographs revealed a series of sharply demarcated concentric ridges in the focused ablation, and less prominent, slightly wavy lines in the defocused ablation performed with a contracting aperture. The focused ablation with an expanding aperture also created concentric ridges toward the periphery, but with slightly smoother edges.

Gender differences in motor performance of 50- to 79-year-old adults.

This study was conducted to assess gender and age differences among 73 men and women (50-59, 60-69, and 70-79 yr.) on five motor tasks (balance, standing long jump, sit and reach, hand grip, and softball throw). Differences between men and women on the standing long jump, hand grip, and the softball throw favored men. The men had better performance scores than the women on each of these tasks. An interaction of gender by age was noted on the balance task. Women 50-59 yr. old balanced significantly longer than the men of that age group. Age differences were found for the standing long jump, hand grip, and softball throw. The 50-59 age group performed significantly better than the 60-69 and the 70-79 age groups. Performance decreased on each task across age groups. These findings suggest gender differences in motor performance of older adults as has been noted for children.

The influence of proficiency level, transfer distality, and gender on the contextual interference effect.

This study examined the impact of high and low proficiency level, transfer distality, and gender on the contextual interference effect with an open skill. Subjects were separated into two levels of proficiency based on performance on a pretest similar to the experimental task. Analysis of error scores during acquisition indicated that the partitioning of subjects according to ability level had been successful. Transfer distality was varied by presenting subjects with two tasks varying in similarity to the acquisition task. Analysis of absolute constant, constant, variable, and total error scores in transfer strongly suggested that subjects' consistency rather than response bias was affected by the experimental variables. The findings suggested that, for the task used in this study, proficiency level does not account for gender differences in the contextual interference effect, as the effect was only reliably found for females. For coincident timing skills, it appears that there may be two distinct conclusions drawn from the results of this study: contextual interference only benefits female subjects' consistency and the effect of contextual interference increases with the distality of transfer, regardless of the subjects' proficiency level.

The relationship between children's perceived and actual motor competence.

To examine the relationship between children's perceived and actual motor competence, 218 children between the ages of 9 and 11 years individually completed the Motor Skill Perceived Competence Scale. After completing the scale, the subject's actual motor competence was measured on a series of gross motor tests. Incomplete principal component analysis identified two actual motor competence dimensions from the motor test battery. The two factors included a lower-body and an upper-body factor of actual motor competence. A two-factor analysis of variance indicated that the boys and girls differed in perceived competence and actual competence. The boys showed higher perceived competence and actual motor competence. In addition, the 9-, 10-, and 11-year-old age groups differed from each other on the lower-body factor of actual motor competence. As age increased, lower-body competence increased. Regression analysis indicated that actual and perceived motor competence was moderately correlated. Adding age to the multiple regression model significantly increased the multiple correlation. Adding gender to the model did not increase the correlation, showing that perceived competence was a function of actual motor competence and age, and this finding held for boys and girls. These findings showed that 9-, 10-, and 11-yr-old children can assess personal motor competence. However, practitioners should attempt to understand children's perceived competence given that their assessments are not extremely accurate.

How should Fitts' Law be applied to human-computer interaction?

The paper challenges the notion that any Fitts' Law model can be applied generally to human-computer interaction, and proposes instead that applying Fitts' Law requires knowledge of the users' sequence of movements, direction of movement, and typical movement amplitudes as well as target sizes. Two experiments examined a text selection task with sequences of controlled movements (point-click and point-drag). For the point-click sequence, a Fitts' Law model that used the diagonal across the text object in the direction of pointing (rather than the horizontal extent of the text object) as the target size provided the best fit for the pointing time data, whereas for the point-drag sequence, a Fitts' Law model that used the vertical size of the text object as the target size gave the best fit. Dragging times were fitted well by Fitts' Law models that used either the vertical or horizontal size of the terminal character in the text object. Additional results of note were that pointing in the point-click sequence was consistently faster than in the point-drag sequence, and that pointing in either sequence was consistently faster than dragging. The discussion centres around the need to define task characteristics before applying Fitts' Law to an interface design or analysis, analyses of pointing and of dragging, and implications for interface design.

Influence of perceived competence and causal dimension orientation on expectations, persistence, and performance during perceived failure.

This investigation was conducted to compare the influence of high and low perceived competence (PC) and various causal dimension orientations on expectations, persistence, and performance while perceiving failure on a motor task. Based on a response to a PC scale, 84 junior high school students were selected to participate in this study. Separately, 42 low and 42 high PC subjects were oriented to perceive their performance on a stabilometer balancing task as due to: (a) internal, controllable, unstable factors (ICU); (b) internal, uncontrollable, stable factors (IUS); or (c) nothing in particular (NDO). Subjects then received fictitious negative feedback over 15 trials. Results revealed that persistence, expectations, and performance dependent measures were significant for PC and Causal Dimension groups. More specifically, the High PC group persisted longer, had higher expectations, and performed significantly better than the Low PC group. Furthermore, the subjects presented ICU orientations persisted for a longer amount of time, revealed higher expectations over trials, and performed significantly better over trials than the subjects in the IUS and NDO groups. These findings suggest that perceived competence and causal dimensional orientations influence children's expectations, persistence, and performance when perceiving failure on a motor task.

White sponge nevus. Diagnosis by light microscopic and ultrastructural cytology.

The lesions of white sponge nevus, an autosomal dominant abnormality of squamous epithelial differentiation that primarily affects the oral cavity, may be grossly similar to those of other hereditary mucosal syndromes, infections or preneoplastic/neoplastic processes. This differential diagnosis is best resolved in many cases by exfoliative cytology, interpreted in the context of clinical history and physical findings. The following report describes a case of white sponge nevus with typical clinical and cytologic findings, in which the diagnosis was confirmed by ultrastructural cytology. Light microscopic cytology revealed parakeratotic cells and many cells containing dense eosinophilic intracytoplasmic inclusions. Electron micrographs of exfoliated cells demonstrated that these inclusions are composed of disordered aggregates of tonofilaments.

The in vitro growth and characterization of the skeletal muscle component of Wilms' tumor.

Skeletal muscle differentiation within a Wilms' tumor is a well-documented histopathologic entity thought to occur at a relatively low incidence and influence prognosis. A serum-free hormonally defined growth medium has been developed, allowing the long-term growth of the skeletal muscle component of Wilms' tumors. Eight Wilms' tumors have been grown under these conditions. Three cases grew a homogeneous population of cells which ultrastructurally displayed all stages of myogenesis through myotubule formation. They also possessed immunoreactivity for skeletal muscle myosin and myoglobin and synthesized the M and B subunits of creatine kinase. Of interest was the finding that the ability to yield skeletal muscle cultures was limited to those cases which exhibited skeletal muscle fibers in vivo. This technique is also a very sensitive marker for identifying Wilms' tumors possessing a myoid component. A second serum-free hormonally defined medium has also been developed that supports the long-term culture of a unique cell type from Wilms' tumors which contain a myoid component. These cells are spindle-shaped and exhibit all of the characteristics of early myoblasts.

Explant culture of human submandibular gland epithelial cells: evidence for ductal origin.

As an approach to investigating the disease cystic fibrosis, attempts were undertaken to culture from human submandibular glands epithelial cells with a potential for manifesting the cystic fibrosis genetic defect. To initiate the culture of submandibular gland epithelial cells, tissue fragments from glands were explanted as a function of both the composition of the serum-free growth medium and of the matrix utilized to coat the culture vessel growth surface. A morphologically homogeneous growth of submandibular gland epithelial cells, uncontaminated by fibroblasts, was obtained, once optimum culture conditions were defined. Light microscopic examination of these explant cultures in a transverse plane of section demonstrated variation in the outgrowth according to distance from the explant. At its outer margin, the outgrowth consisted of one or two layers of viable low cuboidal cells, and more centrally, it was multilayered. Mitotic figures were observed in the periphery of the outgrowth. In the region, a few cells removed from the periphery where the outgrowth consisted of about three to six cell layers, dilated intercellular spaces, indicative of secretion of fluid and ions into the spaces, separated the basal cuboidal cells. Overlying cells were increasingly flattened toward the culture surface and devoid of nuclei. Centrally, near the explant, the multilayer appeared completely involuted throughout. Ultrastructural examination in a transverse plane of the multilayered region with viable basal cells confirmed these observations showing wide spaces separating the cuboidal basal cells, keratinization of midstratum cells, and complete involution of the upper layer of ghost-like cells. These cells cultured from the submandibular gland reacted positively to immunochemical staining for keratin.