We have addressed questions raised by the observation in fetal rats of delayed ossification induced by caffeine at maternal doses above 80 mg/kg body weight per day. The effect of caffeine on endochondral bone development and mineralization has been studied in an experimental model system of bone formation which involves implantation of demineralized bone particles (DBP) in subcutaneous pockets of young growing rats. Caffeine's effects on cellular events associated with endochondral ossification were examined directly by quantitating cellular mRNA levels of chondrocyte and osteoblast growth and differentiation markers in DBP implants from caffeine-treated rats harvested at specific stages of development (day 7 through day 15). Oral caffeine administration to rats implanted with DBP resulted in a dose dependent inhibition of the formation of cartilage tissue in the implants. Histologic examination of the implants revealed a decrease in the number of cells which were transformed to chondrocytes compared to control implants. Those cartilaginous areas that did form, however, proceeded through the normal sequelae of calcified cartilage and bone formation. At the 100 mg/kg dose, cellular levels of mRNA for histone, collagen type II, and TGF beta were all reduced by greater than 40% of control implants consistent with the histological findings. Alkaline phosphatase activity in the implants and mRNA levels for proteins reflecting the hypertrophic chondrocyte and bone phenotype, collagen type I and osteocalcin were markedly decreased compared to controls. Lower doses of 50 and 12.5 mg/kg caffeine also resulted in decreased cellular proliferation and transformation to cartilage histologically and reflected by significant inhibition of type II collagen mRNA levels (day 7). The effects of caffeine on gene expression observed in vivo during the period of bone formation (day 11 to day 15) in the DBP model were similar to the inhibited expression of H4, alkaline phosphatase, osteocalcin, and osteopontin found in fetal rat calvarial derived osteoblast cultures following 24 hour exposure of the cultures to 0.4 mM caffeine. Thus the observed delayed mineralization in the fetal skeleton associated with caffeine appears to be related to an inhibition of endochondral bone formation at the early stages of proliferation of undifferentiated mesenchymal cells to cartilage specific cells as well as at later stages of bone formation.

One of the most understudied health disparity populations in the United States is the Deaf community-a sociolinguistic minority group of at least 500,000 individuals who communicate using American Sign Language. Research within this population is lacking, in part, due to researchers' use of methodologies that are inaccessible to Deaf sign language users. Traditional qualitative methods were developed to collect and analyze participants' spoken language. There is, therefore, a paradigm shift that must occur to move from an auditory data schema to one that prioritizes the collection and analysis of visual data. To effectively navigate this shift when working with Deaf sign language users, there are unique linguistic and sociopolitical considerations that should be taken into account. The current article explores these considerations and outlines an emerging method of conducting qualitative analysis that, we argue, has the potential to enhance qualitative researchers' work regardless of the population of focus.

One of the most understudied health disparity populations in the United States is the Deaf community, a sociolinguistic minority group of more than 500,000 individuals who communicate via American Sign Language. Research on Deaf health disparities is lacking due to inaccessible recruitment, sampling, and data collection procedures, as well as the fundamental disconnect between medical and cultural views of Deaf people. A potential starting place for addressing inaccessible research methods and mistrust of the biomedical research community is the careful reconsideration of the traditional informed consent process, often a Deaf individual’s first point of contact with the research world. Yet, most Deaf individuals experience obstacles to engaging in informed consent due to differences in language and development compared to hearing individuals. In response to these issues, our team led a three-phase, formative, community-engaged approach to adapt the informed consent process and train research staff in the updated method so that all required components are properly communicated and understood. The goals of our work were to promote Deaf engagement in research about the Deaf community, increase the number of Deaf individuals who participate in general population biomedical research, and generalize our findings to improve research accessibility for the general population.

The U.S. Deaf community is a sociolinguistic minority group of 500,000 Americans who communicate using American Sign Language (ASL). This population is one of the most understudied populations in biomedical research. At this time, most research procedures are not designed to provide access to Deaf people and informed consent procedures for research are not provided in an accessible language for Deaf participants. Furthermore, because of a long history of mistreatment of Deaf people in the research world, there is a feeling of mistrust toward researchers and strong resistance to enrolling in research studies. 1-3 It is vital that researchers find a way to improve access and build trust with the Deaf community to include this underserved and at-risk population in biomedical research.

The U.S. Deaf community-a sociolinguistic minority group of 500,000 Americans who communicate using American Sign Language (ASL)-is often not included in health research. Deaf people, however, constitute a high risk population who experience higher rates of obesity, domestic violence, and suicide than the general population. 1 While future health studies need to include Deaf people in their samples, most research procedures do not meet the needs of the Deaf community. For example, all human subjects' research involves an informed consent process, during which potential participants learn about research procedures, possible risks of being in the research study, and then decide if they would like to participate in the study. This information is usually communicated in written or spoken English, rather than translated into ASL, making the process inaccessible to the Deaf community. In addition, the Deaf community often feels mistrust toward researchers and strong resistance to enrolling in research studies because of the long history of mistreatment of Deaf people in the research world. 2-4 Researchers must develop ways to improve access and build trust with the Deaf community to include this underserved and at-risk population in human subjects' research studies.