Immunolocalization and regulation of cystic fibrosis transmembrane conductance regulator in the adult rat epididymis

Cystic fibrosis is the most common serious autosomal recessive condition in whites, and more than 95% of men with cystic fibrosis are infertile. The cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic adenosine monophosphate (cAMP)-regulated chloride channel, has been localized in the efferent ducts; however, to our knowledge, its expression and regulation in the epididymis by testicular factors have not been examined. In the present study, these parameters were examined immunocytochemically by the light microscope with an anti-CFTR antibody in Bouin-fixed, paraffin-embedded control adult rat epididymides and both orchidectomized adult rats with or without testosterone supplementation and efferent duct-ligated rats sacrificed at different time points. In control animals, a thick dense band of immunoperoxidase reaction product was visualized over the apical plasma membrane of the principal cells but not their microvilli. The apical band was prominent only in the corpus and cauda regions. While there was no CFTR expression in basal cells, clear cells of the corpus and cauda regions showed a weak-to-moderate band of apical plasma membrane staining. An examination of orchidectomized, orchidectomized and testosterone, and efferent duct-ligated rats revealed that CFTR was no longer expressed as an intense band on the apical plasma membrane of the principal cells of the corpus and cauda regions. However, under these conditions, an intense apical/supranuclear reaction was noted in the form of small vesicular structures. Clear cells were unaffected by the different experimental treatments. Together, these data indicate that CFTR is expressed in a cell- and region-specific manner and that, while its synthesis in principal cells is not under the control of testicular factors, targeting to the apical plasma membrane is regulated by a testicular luminal factor.     

Postnatal development and regulation of beta-hexosaminidase in epithelial cells of the rat epididymis

beta-Hexosaminidase (Hex) catalyzes the hydrolysis of terminal sugar residues from a number of substrates such as GM2 gangliosides, glycoproteins, glycolipids, and glycosaminoglycans. As an enzyme present in lysosomes of epithelial cells of the adult rat epididymis, it serves to degrade substances endocytosed from the epididymal lumen. In this way, it modifies and creates a luminal environment where sperm can undergo their maturational modifications. In this study, the postnatal developmental pattern of expression of Hex was examined in animals from days 7-56. In addition, the role of testicular factors on Hex expression in the different cell types and regions of the epididymis of adult rats was examined in orchidectomized and efferent duct-ligated rats. Both parameters were examined on Bouin-fixed epididymides in conjunction with light microscope immunocytochemistry. At postnatal day 7, the epithelium of the entire epididymis was unreactive for anti-Hex antibody. By day 21, narrow and clear cells of their respective regions became reactive, whereas basal cells became reactive only by day 29. Principal cells displayed only an occasional reactive lysosome at day 21, several by day 29, and numerous reactive lysosomes by day 39, comparable to the region-specific distribution noted for 90-day-old animals, and at an age when high androgen levels are attained. Thus, postnatal onset of Hex expression varies according to the different cell types of the epididymis, suggesting different regulatory factors. This finding was confirmed from studies employing adult orchidectomized and efferent duct-ligated adult rats. Indeed, in all experimental animals, Hex immunostaining in narrow, clear, and basal cells was intense and comparable to control animals. In contrast, there was a notable absence of lysosomal staining in principal cells at all time points after orchidectomy, which was restored, however, following testosterone replacement. No effect on Hex expression was observed in efferent duct-ligated animals. Taken together, the data suggest that Hex expression in lysosomes of principal cells is regulated by testosterone or one of its metabolites. However, the expression of Hex being independent of testicular factors in narrow, clear, and basal cells of adult animals, but occurring at different time points during postnatal development, suggests that different regulatory factors are responsible for onset of Hex expression in these cell types during development.     

Limited, protected postsurgical motion does not affect the results of digital nerve repair

PURPOSE: Casting for 3 to 4 weeks has been the accepted protocol after primary repair of digital nerve lacerations. In contrast, combined digital nerve and flexor tendon repairs are rehabilitated with immediate postsurgical range of motion. The purpose of this study was to compare the results of primary nerve repair in isolated digital nerve lacerations immobilized after surgery with nerve repairs combined with flexor tendon repairs that are mobilized in a limited, protected fashion immediately after surgery. METHODS: We reviewed retrospectively patients who had had surgical repair of isolated digital nerve lacerations or combined digital nerve and flexor tendon lacerations. Demographics recorded included age, hand dominance, injured digit, and time to mobilization. Follow-up data included range of motion at the metacarpophalangeal, proximal interphalangeal, distal interphalangeal, and wrist joints; static 2-point discrimination; and Semmes-Weinstein monofilament testing. Between-group comparisons were based on t-tests for continuous measures and chi-square tests for categoric measures. Paired t-tests were used for within-group comparisons. All comparisons were based on 2-tailed.05-level tests. RESULTS: Fourteen patients (16 digits) with isolated nerve repairs (group 1) and 12 patients (14 digits) with combined nerve and tendon repairs (group 2) were evaluated. The average age and duration at follow-up evaluation were similar in the 2 groups. The average time to mobilization, however, was 21 days in group 1 and 4 days in group 2. Injuries occurred equally in dominant and nondominant hands. Good range of motion returned in all digits. In addition there was no significant difference in final 2-point discrimination and Semmes-Weinstein testing between groups 1 and 2. CONCLUSIONS: Our data showed a decrease in sensibility between the injured and uninjured digits in each of the 2 groups studied, as has been shown previously. The difference in sensibility between the 2 groups, however, was not statistically significant. These data challenge the long-held belief that digital nerve repairs should be completely immobilized after surgery.     

Tracking of physical activity from childhood to adulthood

PURPOSE: To examine 1) relationships between adult PA at 35 yr and PA as a child, and 2) the influence of enhanced primary school physical education (physed+) and of parental PA upon the long-term tracking of PA in the offspring. METHODS: PA data from the 1970-1977 Trois-Rivieres Growth and Development Study, completed when the children were aged 10-12 yr, were compared with PA data collected on 166 of the same subjects in 1996-1998, when aged 34.9 +/- 1.1 yr. The weekly duration of total PA, intense PA, light PA, organized PA, and total sedentary behaviors other than sleep as a child were each correlated with a questionnaire assessment of total weekly PA as an adult. RESULTS: Considering males and females jointly, adult PA showed a significant but weak association with childhood PA, correlations for total PA, intense PA, light organized PA, and nonorganized PA amounting to r = 0.20, 0.18, 0.12, and 0.19, respectively. In males (N = 79), the total time spent during childhood in organized PA was associated with adult PA (r = 0.26, P < 0.05), due to students who received physed+ (r = 0.34). In females, also, a higher PA frequency as an adult was significantly associated with physed+. There was no association of PA patterns between children and their parents. CONCLUSION: Our results suggest a positive impact of early required physical education upon adult PA but provide little evidence of an overall association between time spent in other categories of PA during childhood and PA as an adult.     

The human gene map for performance and health-related fitness phenotypes: the 2003 update

This review presents the 2003 update of the human gene map for physical performance and health-related fitness phenotypes. It is based on peer-reviewed papers published by the end of 2003 and includes association studies with candidate genes, genome-wide scans with polymorphic markers, and single-gene defects causing exercise intolerance to variable degrees. The genes and markers with evidence of association or linkage with a performance or fitness phenotype in sedentary or active people, in adaptation to acute exercise, or for training-induced changes are positioned on the genetic map of all autosomes and the X chromosome. Negative studies are reviewed but a gene or locus must be supported by at least one positive study before being inserted on the map. By the end of 2000, 29 loci were depicted on the first edition of the map. In contrast, the 2003 human gene map for physical performance and health-related phenotypes includes 109 autosomal gene entries and QTL, plus two on the X chromosome. Moreover, there are 15 mitochondrial genes in which sequence variants have been shown to influence relevant fitness and performance phenotypes.     

Display color affects motion sickness symptoms in an optokinetic drum

BACKGROUND: Many stationary participants who view the patterned interior of a rotating cylinder (optokinetic drum) experience motion sickness (MS) symptoms. Most drum interiors have consisted of black and white patterns. An experiment was conducted to investigate the effects of chromaticity on MS onset and severity. METHODS: There were 12 individuals who participated in the experiment (4 men, 8 women, mean age = 25). Keeping rotation speed constant (5 RPM), the color of vertical stripes in an optokinetic drum was manipulated. There were three conditions used: 1) alternating black and white stripes; 2) gray stripes having different luminance values; and 3) chromatic stripes (white, red, yellow, black, green, and blue) that approximately matched the luminance values of the stripes in the gray condition. Every 2 min, eight motion sickness symptoms were assessed (for up to 16 min) using a subjective scale (0 = none, 1 = slight, 2 = moderate, 3 = severe). RESULTS: Overall, MS onset was fastest, and symptoms the most severe, in the chromatic condition. The two major MS symptoms that were significantly affected were headache and dizziness. CONCLUSIONS: Chromaticity may affect how much an observer's visual environment appears to be stationary, perhaps because chromaticity is such a common feature of the stationary environment in which our visual system evolved. In an optokinetic drum, the addition of chromaticity may increase the disparity between visual and vestibular inputs, a factor thought by many to contribute to MS onset and severity.