Fiber-reinforced Composite as Oral Implant Material. Experimental studies of glass fiber and bioactive glass in vitro and in vivo

Fiber-reinforced composite as oral implant material: Experimental studies of glass fiber and bioactive glass in vitro and in vivo Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku, Turku, Finland 2008. Biocompatibility and mechanical properties are important variables that need to be determined when new materials are considered for medical implants. Special emphasis was placed on these characteristics in the present work, which aimed to investigate the potential of fiber-reinforced composite (FRC) material as an oral implant. Furthermore, the purpose of this study was to explore the effect of bioactive glass (BAG) on osseointegration of FRC implants. The biocompatibility and mechanical properties of FRC implants were studied both in vitro and in vivo. The mechanical properties of the bulk FRC implant were tested with a cantilever bending test, torsional test and push-out test. The biocompatibility was first evaluated with osteoblast cells cultured on FRC substrates. Bone bonding was determined with the mechanical push-out test and histological as well as histomorplanimetric evaluation. Implant surface was characterized with SEM and EDS analysis. The results of these studies showed that FRC implants can withstand the static load values comparably to titanium. Threaded FRC implants had significantly higher push-out strength than the threaded titanium implants. Cell culture study revealed no cytotoxic effect of FRC materials on the osteoblast-like-cells. Addition of BAG particles enhanced cell proliferation and mineralization of the FRC substrates The in vivo study showed that FRC implants can withstand static loading until failure without fracture. The results also suggest that the FRC implant is biocompatible in bone. The biological behavior of FRC was comparable to that of titanium after 4 and 12 weeks of implantation. Furthermore, addition of BAG to FRC implant increases peri-implant osteogenesis and bone maturation.

The Changing Face of Psychiatric Nursing –Care or Control?

This report has been written as part of the project “Toward improved quality – developing nurse’s continuing vocational training in hospitals and inpatient units”. Its overall goal is to ensure high quality, ethically appropriate and therapeutically effective interventions to enable nurses to manage distressed and disturbed patients in European psychiatric hospitals and inpatient units. In this large-scale, multinational projects there are all together six European countries involved: Finland, Ireland, England, Portugal, Italy and Lithuania. The project work plan were during autumn 2006 and spring 2007. The content of this publication was produced in the first stage of the project aiming to collect the preliminary source material for the project. The literature review was carried out in the project stage, providing the groundwork for the next steps for the project. This project aims to develop an interactive multinational portal with training material. Therefore, it is important to share an understanding of basic information, psychiatric nurse’s continuing vocational education, laws and ethical codes and patient restriction used in mental health care. In this publication, the purpose of the material produced here is to understand nurses’ educational need related to vocational continuing education and to be used in further project stages as an empirical data collection. The data were collected as a preliminary source material for latter phases where nurse’s perceptions of the current practice, nurse’s attitudes to mental illness, prevalence of use of seclusion room and existing and desired vocational training provision will be collected in six different European countries. The following organisations are involved in this project: University of Turku, Dublin City University, St. Vincent Hospital, National Council for the Professional Development of Nursing and Midwifery, University of Padova, Klaipeda College - Health Faculty, Klaipeda Psychiatric Hospital, Escola Superior de Enfermagem de Lisboa, Centro Hospitalar Psiquiátrico de Lisboa, Omnia Vocational Institution the Espoo Region, Kellokoski psychiatric hospital, Hyvinkää hospital area, Pirkanmaa Hospital District, Kingston University & St. George’s Medical School and South West London & St. George’s Mental Health NHS Trust. A wide variety of different countries, organisations and individuals in this project give us a strong confidence that theoretical, practical, ethical and political issues around the topic of interest will be taken account during this project lifetime. We are aware the content of this book will be partially outdated almost as soon as it has been published. We still hope that this publication will encourage nurses and different professions working in mental health care field to have a basic understanding of similarities and differences between different European countries related in mental health care. We also hope that this publication will inspirate and motivate nurses in maintaining and developing the quality of psychiatric care in Europe.

The Effects of Endocrine Disrupters on Fetal Male Rat Testicular and Adrenal Development

Many of the reproductive disorders that emerge in adulthood have their origin during fetal development. Numerous studies have demonstrated that exposure to endocrine disrupting chemicals can permanently affect the reproductive health of experimental animals. In mammals, male sexual differentiation and development are androgen-dependent processes. In rat, the critical programming window for masculinization occurs between embryonic days (EDs) 15.5 and 19.5. Disorders in sex steroid balance during fetal life can disturb the development of the male reproductive tract. In addition to the fetal testis, the adrenal cortex starts to produce steroid hormones before birth. Glucocorticoids produced by the adrenal cortex are essential for preparing the fetus for birth. In the present study, the effects of exposure to endocrine disrupters on fetal male rat testicular and adrenal development were investigated. To differentiate the systemic and direct testicular effects of endocrine disrupters, both in vivo and in vitro experiments were performed. The present study also clarified the role of desert hedgehog signalling (Dhh) in the development of the testis. The results indicate that endocrine disrupters, diethylstilbestrol (DES) and flutamide, are able to induce rapid steroidogenic changes in fetal rat testis under in vitro conditions. Although in utero exposure to these chemicals did not show overt effects in fetal testis, they can induce permanent changes in the developing testis and accessory sex organs later in life. We also reported that exposure to antiandrogens can interfere with testicular Dhh signalling and result in impaired differentiation of the fetal Leydig cells and subsequently lead to abnormal testicular development and sexual differentiation. In utero exposure to tetrachlorodibenzo-p-dioxin (TCDD) caused direct testicular and pituitary effects on the fetal male rat but with different dose responses. In a study in which the effects of developmental exposure to environmental antiandrogens, di-isononylphthalate and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p^’-DDE), on fetal male rat steroidogenesis were investigated, chemicals did not down-regulate testicular or adrenal steroid hormone synthesis or production in 19.5-day-old fetal rats. However, p,p^’-DDE-treatment caused clear histological and ultrastructural changes in the prenatal testis and adrenal gland. These structural alterations can disturb the development and function of fetal testis and adrenal gland that may become evident later in life. Exposure to endocrine disrupters during fetal life can cause morphological abnormalities and alter steroid hormone production by fetal rat Leydig cells and adrenocortical cells. These changes may contribute to the maldevelopment of the testis and the adrenal gland. The present study highlights the importance of the fetal period as a sensitive window for endocrine disruption.

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