Interacting roles of myofibroblasts, apoptosis and fibrogenic growth factors in the pathogenesis of renal tubulo-interstitial fibrosis

The interrelationship between myofibroblasts and fibrogenic growth factors in the pathogenesis of renal fibrosis is poorly defined. A temporal and spatial analysis of myofibroblasts, their proliferation and death, and presence of transforming growth factor-beta1 (TGF-beta1) and platelet-derived growth factor-B (PDGF-B) was carried out in an established rodent model in which chronic renal scarring and fibrosis occurs after healed renal papillary necrosis (RPN), similar to that seen with analgesic nephropathy. Treated and control groups (N = 6 and 4, respectively) were compared at 2, 4, 8 and 12 weeks. A positive relationship was found between presence of tubulo-interstitial myofibroblasts and development of fibrosis. Apoptotic myofibroblasts were identified in the interstitium and their incidence peaked 2 weeks after treatment. Levels of interstitial cell apoptosis and fibrosis were negatively correlated over time (r = -0.57, p < 0.01 ), suggesting that as apoptosis progressively failed to limit myofibroblast numbers, fibrosis increased. In comparison with the diminishing apoptosis in the interstitium, the tubular epithelium had progressively increasing levels of apoptosis over time, indicative of developing atrophy of nephrons. TGF-beta1 protein expression had a close spatial and temporal association with fibrosis and myofibroblasts, whilst PDGF-B appeared to have a closer link with populations of other chronic inflammatory cells such as infiltrating lymphocytes. Peritubular myofibroblasts were often seen near apoptotic cells in the tubular epithelium, suggestive of a paracrine toxic effect of factor/s secreted by the myofibroblasts. In vitro , TGF-beta1 was found to be toxic to renal tubular epithelial cells. These findings suggest an interaction between myofibroblasts, their deletion by apoptosis, and the presence of the fibrogenic growth factor TGF-beta1 in renal fibrosis, whereby apoptotic deletion of myofibroblasts could act as a controlling factor in progression of fibrosis.

Microevolution in island forms: the roles of drift and directional selection in morphological divergence of a passerine bird

Theory predicts that in small isolated populations random genetic drift can lead to phenotypic divergence; however this prediction has rarely been tested quantitatively in natural populations. Here we utilize natural repeated island colonization events by members of the avian species complex, Zosterops lateralis, to assess whether or not genetic drift alone is an adequate explanation for the observed patterns of microevolutionary divergence in morphology. Morphological and molecular genetic characteristics of island and mainland populations are compared to test three predictions of drift theory: (1) that the pattern of morphological change is idiosyncratic to each island; (2) that there is concordance between morphological and neutral genetic shifts across island populations; and (3) for populations whose time of colonization is known, that the rate of morphological change is sufficiently slow to be accounted for solely by genetic drift. Our results are not consistent with these predictions. First, the direction of size shifts was consistently towards larger size, suggesting the action of a nonrandom process. Second, patterns of morphological divergence among recently colonized populations showed little concordance with divergence in neutral genetic characters. Third, rate tests of morphological change showed that effective population sizes were not small enough for random processes alone to account for the magnitude of microevolutionary change. Altogether, these three lines of evidence suggest that drift alone is not an adequate explanation of morphological differentiation in recently colonized island Zosterops and therefore we suggest that the observed microevolutionary changes are largely a result of directional natural selection.

Patterns of change and stability in the gender division of household labour in Australia, 1986-1997

Recent research in Australia and overseas has suggested that we are witnessing a convergence of men's and women's time on domestic labour activities. But there is disagreement about whether this is due to women reducing their time on housework or men increasing their time on housework. This article addresses these issues using national survey data collected in Australia in 1986, 1993 and 1997. The results show some changes in the proportional responsibilities of men and women in the home with men reporting a greater share of traditional indoor activities. But overall both men and women are spending less time on housework. In particular, women's time on housework has declined by six hours per week since 1986. Hence, while the gender gap between men's and women's involvement in the home is getting smaller, it is not the result of men increasing their share of the load, but is due to the large decline in women's time spent on domestic labour. There is also evidence of change in the relationship. between paid and unpaid work for women. Women's hours of,paid labour had a greater impact on their involvement in domestic labour in 1997 compared to a decade earlier. The article concludes that women's increased labour force involvement in combination with changing patterns and styles, of consumption is leading to some changes in the gender-division:of household labour, but not in the direction anticipated by earlier commentators on the domestic division of labour.

Can medical education be fun as well as educational?

Today's challenge to medical educators is to provide continuing education that supports excellence in clinical practice while finding new approaches to make learning more stimulating, motivating, and entertaining. At our hospital we are experimenting with innovative teaching techniques, incorporating games and debate, which encapsulate core concepts of the theory of adult learning: active participation by learners, application of knowledge, informal presentation, and feedback(1).

Racialised schooling, 'ethnic success' and Asian-Australian students

Based on discussions with Asian-Australian young women at a mixed-sex, Australia State high school, this article argues that the pro-school conformity of Asian-Australian young women sets them in a problematic and precarious relationship to the material and symbolic and processes of racialisation. The first part of the article identifies the limitations of research into the pro-school/anti-school orientations of minority students, arguing that most accounts are based on theories of culture, acculturation, class and gender, and class and race that neglect an analysis of race and sex. I then argue that practices of racialisation and sexualisation actually sustain pro-school culture and Asian female group associations. While these formations are effective in securing Asian female educational success, they are also problematic because they limit the educational possibilities and employment opportunities of Asian young women in Australia.

Acoustic signature of the normal swallow: Characterization by age, gender, and bolus volume

Despite growing clinical use, cervical auscultation suffers from a lack of research-based data. One of the strongest criticisms of cervical auscultation is that there has been little research to demonstrate how dysphagic swallowing sounds are different from normal swallowing sounds, In order to answer this question, however, one first needs to document the acoustic characteristics of normal, nondysphagic swallowing sounds, This article provides the first normative database of normal swallowing sounds for the adult population. The current investigation documents the acoustic characteristics of normal swallowing sounds for individuals from 18 to more than 60 years of age over a range of thin liquid volumes. Previous research has shown the normal swallow to be a dynamic event. The normal swallow is sensitive to aging of the oropharyngeal system, and also to the volume of bolus swallowed. The current investigation found that the acoustic signals generated during swallowing were sensitive to an individual's age and to the volume of the bolus swallowed. There were also some gender-specific differences in the acoustic profile of the swallowing sound, It is anticipated that the results will provide a catalyst for further research into cervical auscultation.

Up close and personal on physical education teachers' identity: Is conflict an issue?

Much of the research on teachers' work is informed by role theory, that assumes teachers' identity is largely ascribed. When there are inconsistencies in teachers' and others' expectations for different occupational roles such as physical education teacher and sports coach, 'role conflict' is said to occur. This stud), sought to investigate if role conflict was a major concern for Australian physical education teacher/coaches. Findings, informed by case studies with five teacher/coaches, challenge the assumption that moving between professional responsibilities causes role conflict. Rather, in moving across contexts, the physical education teachers managed inconsistencies in ways that resulted in positive and rawarding work experiences.

Globalization and women in southeast Asian higher education management

This paper draws on data from a group case study of women in higher education management in Hong Kong, Singapore, Malaysia, and Thailand. I investigate culture-specific dimensions of what the Western literature has conceptualized as glass ceiling impediments to women's career advancement in higher education. I frame my argument within recent debates about globalization and glocalization to show how the push-pull and disjunctive dynamics of globalization are experienced in local sites by social actors who traverse global flows and yet remain tethered to local discourses, values, and practices. All of the women in this study were trained in Western universities and are fluent English speakers, world-class experts in their fields, well versed with equity discourses, and globally connected on international nongovernment organization (NGO) and academic circuits. They are indeed global cosmopolitans. And yet their testimonies indicate that so-called Asian values and religious-cultural ideologies demand the enactment of a specific construct of Asian femininity that militates against meritocratic equality and academic career aspirations to senior management levels. Despite the global nature of the University and increasing global flows of academics, students, and knowledge, the politics of academic glass ceilings are not universal but always locally inflected with cultural values and norms. As such, the politics of disadvantage for women in higher education require local and situated analyses in the context of global patterns of the educational status Of women and the changing nature of higher education.

Age and gender differences in objectively measured physical activity in youth

TROST. S. G., R. R. PATE, J. F. SALLIS, P. S. FREEDSON, W. C. TAYLOR, M. DOWDA, and J. SIRARD. Age and gender differences in objectively measured physical activity in youth. Med. Sci. Sports Ererc., Vol. 34, No. 2, pp. 350-355, 2002. Purpose: The purpose of this study was to evaluate age and gender differences in objectively measured physical activity (PA) in a population-based sample of students in grades 1-12. Methods: Participants (185 male, 190 female) wore a CSA 7164 accelerometer for 7 consecutive days. To examine age-related trends. students were grouped as follows: grades 1-3 (N = 90), grades 4-6 (N = 91), grades 7-9 (N = 96). and grades 10-12 (N = 92). Bouts of PA and minutes spent in moderate-to-vigorous PA (MVPA) and vigorous PA (VPA) were examined. Results: Daily MVPA and VPA exhibited a significant inverse relationship with grade level, with the largest differences occurring between grades 1d-3 and 4-6. Boys were more active than girls; however, for overall PA, the magnitudes of the gender differences were modest. Participation in continuous 20-min bouts of PA was low to nonexistent. Conclusion: Our results support the notion that PA declines rapidly during childhood and adolescence and that accelerometers are feasible alternatives to self-report methods in moderately sized population-level surveillance studies.