Inhibition of cell proliferation does not slow down echinoderm neural regeneration

BACKGROUND: Regeneration of the damaged central nervous system is one of the most interesting post-embryonic developmental phenomena. Two distinct cellular events have been implicated in supplying regenerative neurogenesis with cellular material – generation of new cells through cell proliferation and recruitment of already existing cells through cell migration. The relative contribution and importance of these two mechanisms is often unknown. METHODS: Here, we use the regenerating radial nerve cord (RNC) of the echinoderm Holothuria glaberrima as a model of extensive post-traumatic neurogenesis in the deuterostome central nervous system. To uncouple the effects of cell proliferation from those of cell migration, we treated regenerating animals with aphidicolin, a specific inhibitor of S-phase DNA replication. To monitor the effect of aphidicolin on DNA synthesis, we used BrdU immunocytochemistry. The specific radial glial marker ERG1 was used to label the regenerating RNC. Cell migration was tracked with vital staining with the lipophilic dye DiI. RESULTS: Aphidicolin treatment resulted in a significant 2.1-fold decrease in cell proliferation. In spite of this, the regenerating RNC in the treated animals did not differ in histological architecture, size and cell number from its counterpart in the control vehicle-treated animals. DiI labeling showed extensive cell migration in the RNC. Some cells migrated from as far as 2 mm away from the injury plane to contribute to the neural outgrowth. CONCLUSIONS: We suggest that inhibition of cell division in the regenerating RNC of H. glaberrima is compensated for by recruitment of cells, which migrate into the RNC outgrowth from deeper regions of the neuroepithelium. Neural regeneration in echinoderms is thus a highly regulative developmental phenomenon, in which the size of the cell pool can be controlled either by cell proliferation or cell migration, and the latter can neutralize perturbations in the former. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12983-017-0196-y) contains supplementary material, which is available to authorized users

Unemployment, Job Insecurity and Health: A Survey of Post-Unification Germany

181 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997.Previous research in sociology and epidemiology has shown strong adverse effects of unemployment on physical and psychological health. However, this research has two major limitations. First, researchers have ignored the effects of potential unemployment--job insecurity--and how its effects may differ from those of actual unemployment. Second, all of the studies have been done in either the U.S. or Western Europe. No study has examined the effects of unemployment or job insecurity on the health of persons living in the former socialist countries. The present study addresses two major questions. First, what is worse for health--unemployment or employment with high levels of job insecurity? Second, do the effects of unemployment and job insecurity differ between the capitalist and former socialist countries? I examine these questions using data from a national representative survey of 2,557 adults in unified Germany in 1992. I discovered that, first, employed persons have health that is better than the health of the unemployed only when those employed feel secure about their jobs. Second, the data show that the poorer health in East Germany (a former socialist society), as compared with West Germany (a capitalist society) results from both greater exposure and greater vulnerability of East Germans to unemployment and job insecurity. Furthermore, the present study challenges the dominating way of researching and thinking in epidemiology and public health--the way of focusing on rather proximate risk factors for major causes of morbidity and mortality. The present study of Germany after unification highlights the importance of placing these risk factors in a broad social context by showing that national economic and structural changes and the resulting growth in unemployment permeate the health of the population.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Firearm suicides and homicides in the United States: regional variations and patterns of gun ownership

Among industrialized countries, the United States has the highest rates of firearm suicide and homicide, as well as the highest rate of gun ownership. The present study compares the differential impact of gun availability on firearm suicides and homicides in the U.S. Using data from the NCHS Mortality Detail Files (1989-1991), the 1990 U.S. census population estimates, and the General Social Surveys (1989-1991) for nine geographic divisions, we computed rates of firearm and non-firearm suicides and homicides as well as rates of gun ownership for four gender-race groups. We tested the strength of the associations between gun availability and firearm suicide and homicide rates by computing the Spearman correlation coefficients. To help elucidate the role of method substitution, we conducted similar analyses on non-firearm suicide and homicide. The results show that gun ownership has a stronger impact on firearm suicides than homicides. These findings held up after stratifying by gender and race. The study suggests that reducing the aggregate level of gun availability may decrease the risk of firearm-related deaths.firearms suicide homicide gun ownership

Firearm suicide among older women in the U.S.

Contrary to the common view that older women (65+) in the United States use suicide methods that have relatively low potential for death, firearms have become the most common suicide method in this group. The present study examines the association between demographic and geographic factors and the use of firearms vs other suicide methods. Data were derived from the National Center for Health Statistics (NCHS) Mortality Detail Files (1989-1991). Results from a logistic regression analysis indicate that among white women 65 and over who died by suicide in 1989-1991, the risk of using firearms varied significantly across demographic and geographic subcategories of the population. The following characteristics among women were significantly more likely to be associated with the use of firearms as a suicide method: ages 65-74, married, of lower educational attainment, in nonmetropolitan areas, and in the South. Research is needed to assess the effects of limiting firearms on the growing proportion of firearm-related suicides among older women.older women suicide firearms

After unification: Gender and subjective health status in East and West Germany

Results of a random survey of 2574 adults in East and West Germany in 1992 show virtually no differences in subjective health status for the populations of East versus West Germany and only slight differences for men versus women. A closer analysis via multiple regression indicates, however, that contrary to previous results from other countries West German women have a better health status than men. Of the four gender groups analyzed separately East German men are the best off, while owing to a number of socio-economic status discrepancies, East German women report the worst health status. Surprisingly, West German men show a poorer subjective health status than East German men, although a number of factors like participation in sport, better income and younger age would predict otherwise. It is suggested that their health situation is negatively influenced not only by their work situation but also by outside private commitments not accounted for in this analysis. Also difficult to explain from the present data is the relatively good health status of East German men. Despite an insecure job and a difficult work situation they may experience unification in sociopolitical terms and their present social status as something positive. Overall, conditions in the system of West Germany show a tendency to favor women, while those in East Germany clearly favor men.German unification subjective health status gender employment work situation

A Minimum 2-Year Follow-up Using Modular Trabecular Metal Tibial Components in Total Knee Arthroplasty

INTRODUCTION: Early failure of tibial components remains a concern in total knee arthroplasty (TKA). Loss of fixation with cemented implants continues to be problematic in young, active patients.  We sought to determine outcomes in patients receiving trabecular metal (TM) implants in a single-surgeon community hospital setting. METHODS: A retrospective analysis was performed on 167 consecutive primary TKAs performed on 133 patients utilizing a TM tibial implant with a minimum two years follow-up. RESULTS: Failure due to aseptic loosening occurred in 4 of the 167 cases (2.4%). Local and systemic complication rates were low. Length of hospital stay and tourniquet time data were also reported. CONCLUSION: Overall complications were low in our cohort of patients receiving TM implants.  Longer follow-up is necessary to determine if the outcomes we observed are sustained over time