Surface pretreatments for medical application of adhesion

Medical implants and prostheses (artificial hips, tendono- and ligament plasties) usually are multi-component systems that may be machined from one of three material classes: metals, plastics and ceramics. Typically, the body-sided bonding element is bone. The purpose of this contribution is to describe developments carried out to optimize the techniques , connecting prosthesis to bone, to be joined by an adhesive bone cement at their interface. Although bonding of organic polymers to inorganic or organic surfaces and to bone has a long history, there remains a serious obstacle in realizing long-term high-bonding strengths in the in vivo body environment of ever present high humidity. Therefore, different pretreatments, individually adapted to the actual combination of materials, are needed to assure long term adhesive strength and stability against hydrolysis. This pretreatment for metal alloys may be silica layering; for PE-plastics, a specific plasma activation; and for bone, amphiphilic layering systems such that the hydrophilic properties of bone become better adapted to the hydrophobic properties of the bone cement. Amphiphilic layering systems are related to those developed in dentistry for dentine bonding. Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body. The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m). This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body

Drug dosing during pregnancy—opportunities for physiologically based pharmacokinetic models

Drugs can have harmful effects on the embryo or the fetus at any point during pregnancy. Not all the damaging effects of intrauterine exposure to drugs are obvious at birth, some may only manifest later in life. Thus, drugs should be prescribed in pregnancy only if the expected benefit to the mother is thought to be greater than the risk to the fetus. Dosing of drugs during pregnancy is often empirically determined and based upon evidence from studies of non-pregnant subjects, which may lead to suboptimal dosing, particularly during the third trimester. This review collates examples of drugs with known recommendations for dose adjustment during pregnancy, in addition to providing an example of the potential use of PBPK models in dose adjustment recommendation during pregnancy within the context of drug-drug interactions. For many drugs, such as antidepressants and antiretroviral drugs, dose adjustment has been recommended based on pharmacokinetic studies demonstrating a reduction in drug concentrations. However, there is relatively limited (and sometimes inconsistent) information regarding the clinical impact of these pharmacokinetic changes during pregnancy and the effect of subsequent dose adjustments. Examples of using pregnancy PBPK models to predict feto-maternal drug exposures and their applications to facilitate and guide dose assessment throughout gestation are discussed

The Use of Curriculum-Based Measures in Young At-Risk Writers: Measuring Change Over Time and Potential Moderators of Change

This study examined gains in written language as assessed by targeted curriculum-based measures (CBMs), and explored how these gains were affected by moderator variables of specific cognitive functions and student subgroups. The sample included 68 second grade students who were at risk for writing disabilities. Handwritten compositions were collected throughout a written language intervention at baseline, sessions 3, 5, 10, 13, 15, 20, 22, and termination. Specific CBM variables included Total Number of Words Written, Words Spelled Correctly, Correct Word Sequences, and Percentage of Correct Word Sequences. Using latent growth curve analysis, models were estimated for each of the CBMs, but the data showed poor model fit. Latent class groupings using cognitive variables and student subgroups significantly moderated the growth rate for written language assessed by specific CBMs. Although these latter findings reflected potential moderators of change in written language, the lack of model fit raised questions around the use of these CBM variables in monitoring writing progress for second grade students at risk for writing disabilities. Findings from this investigation revealed the measurement complexities that likely remain hidden from teachers and other professionals engaged in routine progress monitoring using CBM variables

Carbamazepine clearance and seizure stability during pregnancy

The aims of this study were to characterize the alterations in total and free carbamazepine (CBZ) and total and free carbamazepine-epoxide (CBZ-EPO) clearances during pregnancy; to calculate the change in free fractions of CBZ and CBZ-EPO during pregnancy; and to determine whether seizure worsening is associated with a low ratio to non-pregnant baseline concentration of total or free CBZ or CBZ-EPO. Women on CBZ were enrolled before conception or during pregnancy in this prospective, observational study. Concomitant medications and seizure frequency were recorded. Serum total and free CBZ and CBZ-EPO were collected at each visit. Changes in clearance of all four compounds and free fractions of CBZ and CBZ-EPO were compared to non-pregnant baseline. During pregnancy, the ratios to baseline concentrations of total and free CBZ and CBZ-EPO were compared for months with and without increased seizure frequency. Total and free CBZ and CBZ-EPO clearances were calculated in 15 pregnancies in 12 women. Clearances did not change for any of these compounds during pregnancy. The free fraction of CBZ increased from 0.23 at baseline to a maximum of 0.32 in the third trimester (p=0.008), In the six women on CBZ monotherapy with adequate seizure diaries and blood sampling, seizure worsening did not correspond to a ratio to baseline concentration of less than 0.65 for total or free CBZ or CBZ-EPO. In conclusion, total and free CBZ and CBZ-epoxide clearances did not change substantially during pregnancy, and seizure frequency worsening was not associated with decreased concentrations of total or free CBZ; therefore, therapeutic drug monitoring may not be necessary for all women on CBZ during pregnancy. Further studies with larger sample sizes are needed before definitive recommendations can be made. CBZ monotherapy may be a relatively safe and cost effective treatment option for women with focal epilepsy syndromes during pregnancy

Bringing Community and Academic Scholars Together to Facilitate and Conduct Authentic Community Based Participatory Research: Project UNITED

Cultural competency, trust, and research literacy can affect the planning and implementation of sustainable community-based participatory research (CBPR). The purpose of this manuscript is to highlight: (1) the development of a CBPR pilot grant request for application; and (2) a comprehensive program supporting CBPR obesity-related grant proposals facilitated by activities designed to promote scholarly collaborations between academic researchers and the community. After a competitive application process, academic researchers and non-academic community leaders were selected to participate in activities where the final culminating project was the submission of a collaborative obesity-related CBPR grant application. Teams were comprised of a mix of academic researchers and non-academic community leaders, and each team submitted an application addressing obesity-disparities among rural predominantly African American communities in the US Deep South. Among four collaborative teams, three (75%) successfully submitted a grant application to fund an intervention addressing rural and minority obesity disparities. Among the three submitted grant applications, one was successfully funded by an internal CBPR grant, and another was funded by an institutional seed funding grant. Preliminary findings suggest that the collaborative activities were successful in developing productive scholarly relationships between researchers and community leaders. Future research will seek to understand the full-context of our findings

Exploring personal values, attitudes, perceived injunctive and descriptive norms, and intrapersonal value-attitude relationships in relation to alcohol use and alcohol-related problems among college students

Alcohol use among college students continues to be a public health issue in spite of health promotion activities and programming. College alcohol use literature regularly examines the impact of perceived norms on alcohol use; however, little research has been done on the influence of personal values on alcohol use and alcohol-related problems. The purpose of this study was to examine the relationships between personal values, attitudes, perceived injunctive and descriptive norms, alcohol, and alcohol-related problems. The study also conceptualized and tested an idea termed intrapersonal value-attitude relationship, which was an interaction between values and attitudes. The current study employed a cross-sectional design utilizing a paper-and pencil survey administered to college students (n=910) within the classrooms. Personal attitudes and perceived descriptive norms of alcohol-related problems consistently predicted alcohol use and alcohol-related problems even after controlling for potential confounding variables. The exploration of the innovative concept of intrapersonal value-attitude relationship is a first step to examine the complex relationships between values and attitudes. Findings from this study suggest that the examination of values, attitudes, injunctive and descriptive norms are relevant and worth investigating further in regard to alcohol use and other health behaviors. (Published By University of Alabama Libraries