Repair of calvarial bone defects in mice using electrospun polystyrene scaffolds combined with β-TCP or gold nanoparticles

Non-biodegradable porous polystyrene (PS) scaffolds, composed of microfibers, have been prepared by electrospinning for the reconstruction of large bone defects. PS microfibers were prepared by incorporating β-TCP grains inside the polymer or grafting gold nanoparticles surface functionalized with mercaptosuccinic acid. Cytocompatibility of the three types of scaffolds (PS, β-TCP-PS and Au-PS) was studied by seeding human mesenchymal stem cells. Biocompatibility was evaluated by implanting β-TCP-PS and Au-PS scaffolds into a critical size (4mm) calvarial defect in mice. Calvaria were taken 6, 9, and 12 weeks after implantation; newly formed bone and cellular response was analyzed by microcomputed tomography (microCT) and histology. β-TCP-PS scaffolds showed a significantly higher cell proliferation in vitro than on PS or Au-PS alone; clearly, the presence of β-TCP grains improved cytocompatibility. Biocompatibility study in the mouse calvaria model showed that β-TCP-PS scaffolds were significantly associated with more newly-formed bone than Au-PS. Bone developed by osteoconduction from the defect margins to the center. A dense fibrous connective tissue containing blood vessels was identified histologically in both types of scaffolds. There was no inflammatory foci nor giant cell in these areas. AuNPs aggregates were identified histologically in the fibrosis and also incorporated in the newly-formed bone matrix. Although the different types of PS microfibers appeared cytocompatible during the in vitro experiment, they appeared biotolerated in vivo since they induced a fibrotic reaction associated with newly formed bone

The role of disclosure in relation to assent to participate in HIV-related research among HIV-infected youth: a formative study

<p>Abstract</p> <p>Background</p> <p>The objective of this study was to develop a culturally appropriate approach for obtaining assent from children aged eight to 17 years to participate in paediatric HIV-related operational research in Kinshasa, Democratic Republic of Congo (DRC). Included within this objective was to determine whether or not HIV disclosure should be included as part of the assent process prior to research participation, a component of research participation, or not incorporated in any aspect of the child's involvement in the research. Factors that influence parents' and caregivers' decisions to disclose HIV status to children in non-research contexts were also explored.</p> <p>Methods</p> <p>A qualitative formative study was conducted. Semi-structured interviews were conducted with 19 youth living with HIV, 36 parents and caregivers of youth living with HIV, and 17 health professionals who provide care and support to youth living with HIV and their families. Participants were purposefully selected from three HIV care, treatment and/or psychosocial support programmes in Kinshasa, DRC.</p> <p>Results</p> <p>Most youth interviewed believed minors participating in HIV-related research should be informed of their HIV-positive status. Parents and caregivers and health professionals had varied perspectives on if and when HIV status should be disclosed to minors during research participation. The age of the youth influenced parents and caregivers' responses, and disclosure to adolescents was more frequently supported than disclosure to children.</p> <p>Several parents and caregivers, as well as some health professionals, suggested that minors should never be told their HIV-positive status when participating in HIV-related research, regardless of their age. Within the context of treatment programmes, disclosure of HIV status to minors was supported by youth, parents and caregivers, and health professionals as a means to improve adherence to medication.</p> <p>Conclusion</p> <p>In settings where most minors are unaware of their HIV infection, researchers should consider excluding the term, "HIV", when explaining HIV-related research to minors, and omitting it from assent forms or informational sheets related to research participation. However, an individualized disclosure plan should be initiated with parents and caregivers at the time of enrolment in HIV-related research, particularly in research that involves treatment.</p

Perceived control over condom use among sex workers in Madagascar: a cohort study

<p>Abstract</p> <p>Background</p> <p>Women's perceived control over condom use has been found to be an important determinant of actual condom use in some studies. However, many existing analyses used cross-sectional data and little quantitative information exists to characterize the relationships between perceived control and actual condom use among sex worker populations.</p> <p>Methods</p> <p>We assessed the association between measures of perceived condom use control and self-reported use of male condoms employing data from a longitudinal pilot study among 192 sex workers in Madagascar.</p> <p>Results</p> <p>In multivariable models, a lack of perceived control over condom use with a main partner and having a main partner ever refuse to use a condom when asked were both associated with an increased number of sex acts unprotected by condoms in the past week with a main partner (RR 1.86; 95% CI 1.21-2.85; RR 1.34; 95% CI 1.03-1.73, respectively). Conversely, no measure of condom use control was significantly associated with condom use with clients.</p> <p>Conclusion</p> <p>Perceived control over condom use was an important determinant of condom use with main partners, but not clients, among sex workers in Madagascar. Programs working with sex workers should reach out to main and commercial partners of sex workers to increase male condom use.</p

Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development

Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development

Sputum Smear Microscopy: Evaluation of Impact of Training, Microscope Distribution, and Use of External Quality Assessment Guidelines for Resource-Poor Settings

Sputum smear microscopy is the main and often only laboratory technique used for the diagnosis of tuberculosis in resource-poor countries, making quality assurance (QA) of smear microscopy an important activity. We evaluated the effects of a 5-day refresher training course for laboratory technicians and the distribution of new microscopes on the quality of smear microscopy in 13 primary health care laboratories in Kinshasa, Democratic Republic of Congo. The 2002 external QA guidelines for acid-fast bacillus smear microscopy were implemented, and blinded rechecking of the slides was performed before and 9 months after the training course and microscope distribution. We observed that the on-site checklist was highly time-consuming but could be tailored to capture frequent problems. Random blinded rechecking by the lot QA system method decreased the number of slides to be reviewed. Most laboratories needed further investigation for possible unacceptable performance, even according to the least-stringent interpretation. We conclude that the 2002 external QA guidelines are feasible for implementation in resource-poor settings, that the efficiency of external QA can be increased by selecting sample size parameters and interpretation criteria that take into account the local working conditions, and that greater attention should be paid to the provision of timely feedback and correction of the causes of substandard performance at poorly performing laboratories

Migration, Multiple Sexual Partnerships, and Sexual Concurrency in the Garífuna Population of Honduras

The Garífuna, an ethnic minority group in Honduras, have been disproportionately affected by HIV. Previous research suggests that migration and high rates of multiple sexual partnerships are major drivers of the epidemic. Using data from a 2012 population-based survey, we assessed whether temporary migration was associated with 1) multiple sexual partnerships and 2) sexual concurrency among Garífuna men and women in Honduras. Among both men and women, temporary migration in the last year was associated with an increased likelihood of multiple sexual partnerships and with concurrency, though only the association between migration and multiple sexual partnerships among men was statistically significant (Adjusted Prevalence Ratio 1.7, 95% CI 1.2-2.4). Migration may contribute to HIV/STI vulnerability among Garífuna men and women via increases in these sexual risk behaviors. Research conducted among men and women at elevated risk of HIV should continue to incorporate measures of mobility, including history of internal migration

(Reinforcing) factors influencing a physical education teachers use of the direct instruction model teaching games

he purpose of this study was to explore how a physical education (PE) teacher employed the direct instruction model (DIM) teaching games in a United Kingdom secondary school. The research sought to identify how the teacher utilised the DIM and those factors that influenced his use of the model. Occupational socialization was used to identify the factors that encouraged his use of the DIM. Data were collected from interviews and lesson observations. Inductive data analysis showed that while the teacher presented a ‘full version’ of the DIM, his limited content knowledge impacted on the use of the model in teaching cricket. Factors influencing his use of the model were a sporting perspective, a Post Graduate Certificate in Education mentor and the ability and behaviour of the students. These factors reinforced his undergraduate learning and subsequent use of the DIM. It is suggested that the comparable backgrounds of many PE student teachers may make the DIM an apt model to learn in undergraduate and postgraduate PE courses. However, effective use of the model requires students to be taught and to possess in-depth content knowledge of the game(s)/activities being taught and learned

Clinical Characteristics Associated with Mycoplasma genitalium among Female Sex Workers in Nairobi, Kenya

The prevalence of Mycoplasma genitalium is high in vulnerable populations of women in low-resource settings. However, the epidemiology of infection in these populations is not well established. To determine the prevalence of Mycoplasma genitalium and its association with cervical cytology and other correlates, we recruited 350 female sex workers (FSW) who were 18 to 50 years old in Nairobi, Kenya, for a cross-sectional study. A questionnaire was administered at baseline to obtain information on sociodemographics and sexual behaviors. Women underwent a pelvic exam, during which a physician collected cervical-exfoliation samples for conventional cytology and sexually transmitted infection (STI) testing. Samples were tested for M. genitalium and other STI organisms (Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis) and the E6/E7 mRNA of human papillomavirus (HPV) by Aptima nucleic amplification assays. The prevalence of M. genitalium was 12.9%. FSW who engaged in sexual intercourse during menses were less likely to have M. genitalium infection than those who did not (odds ratio [OR], 0.3; 95% confidence interval [95% CI], 0.1, 0.9). M. genitalium was also less prevalent among FSW who had worked in prostitution for >5 years (6.2%) than among those who had worked for <3 years (17.6%) (OR, 0.3; 95% CI, 0.1, 0.8). FSW who reported more frequent condom use were more likely to be infected with M. genitalium than those who reported less frequent use (OR, 3.8; 95% CI, 1.2, 11.6). These correlates differ from those found in M. genitalium studies conducted with FSW from West Africa and China. Further longitudinal analyses assessing associations with persistent M. genitalium infection are needed

Pulmonary cystic disease in HIV positive individuals in the Democratic Republic of Congo: three case reports

Pulmonary emphysema and bronchiectasis in HIV seropositive patients has been described in the presence of injection drug use, malnutrition, repeated opportunistic infections, such as Pneumocytis jirovici pneumonia and Mycobacterium tuberculosis infection, and has been linked to the presence of HIV virus in lung tissue. Given the high burden of pulmonary infections and malnutrition among people living with HIV in resource poor settings, these individuals may be at increased risk of developing pulmonary emphysema, potentially reducing the long term benefit of antiretroviral therapy (ART) if initiated late in the course of HIV infection