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1.  Sex Differences in Parietal Lobe Structure and Development 
Gender Medicine  2012;9(1):44-55.
Structural MRI studies provide evidence for sex differences in the human brain. Differences in surface area and the proportion of gray to white matter volume are observed, particularly in the parietal lobe. To our knowledge, there are no studies examining sex differences of parietal lobe structure in younger populations or in the context of development. The current study evaluated sex difference in the structure of the parietal lobe in children (7-17 years of age). Also, by adding the cohort of previously studied adults (18-50 years of age), sex differences of parietal lobe morphology were examined across the age span of 7-50 years. In the youth sample, we found that, similar to adults, the ratio of parietal lobe cortex to white matter was greater in females. Unlike the adult sample, there were no sex differences in surface area. When examining effects of age, surface area had a significant sex-by-age interaction. Males had essentially no decrease in surfaces area over time, but females had a significant decrease in surface area over time. These findings support the notion of structural sex differences in the parietal lobe, not only in the context of cross sectional assessment, but also in terms of differences of developmental trajectories.
PMCID: PMC3326392  PMID: 22333522
development; parietal lobe; sex differences; surface area
2.  The ARV roll out and the disability grant: a South African dilemma? 
Prior to the antiretroviral (ARV) drug roll out in 2004, people living with HIV (PLHIV) in South Africa received disability grants when they were defined as "AIDS-sick". In the absence of available and effective medication, a diagnosis of AIDS portended disability. The disability grant is a critical component of South Africa's social security system, and plays an important role in addressing poverty among PLHIV. Given the prevalence of unemployment and poverty, disability grants ensure access to essential resources, like food, for PLHIV. Following the ARV roll out in South Africa, PLHIV experienced improved health that, in turn, affected their grant eligibility. Our aim is to explore whether PLHIV reduced or stopped treatment to remain eligible for the disability grant from the perspectives of both PLHIV and their doctors.
A mixed-methods design with concurrent triangulation was applied. We conducted: (1) in-depth semi-structured interviews with 29 PLHIV; (2) in-depth semi-structured interviews with eight medical doctors working in the public sector throughout the Cape Peninsula; (3) three focus group discussions with programme managers, stakeholders and community workers; and (4) a panel survey of 216 PLHIV receiving ARVs.
Unemployment and poverty were the primary concerns for PLHIV and the disability grant was viewed as a temporary way out of this vicious cycle. Although loss of the disability grant significantly affected the well-being of PLHIV, they did not discontinue ARVs. However, in a number of subtle ways, PLHIV "tipped the scales" to lower the CD4 count without stopping ARVs completely. Grant criteria were deemed ad hoc, and doctors struggled to balance economic and physical welfare when assessing eligibility.
It is crucial to provide sustainable economic support in conjunction with ARVs in order to make "positive living" a reality for PLHIV. A chronic illness grant, a basic income grant or an unemployment grant could provide viable alternatives when the PLHIV are no longer eligible for a disability grant.
PMCID: PMC3305561  PMID: 22340659
4.  Framing rights and responsibilities: accounts of women with a history of AIDS activism 
In South Africa, policy with respect to HIV/AIDS has had a strong rights-based framing in line with international trends and in keeping with the constitutional overhaul in the post-Apartheid era. There have also been considerable advances since 1994 towards legal enshrinement of sexual and reproductive health rights and in the provision of related services. Since HIV in this setting has heavily affected women of reproductive age, there has been discussion about the particular needs of this subgroup, especially in the context of service integration. This paper is concerned with the way in which HIV positive women conceptualise these rights and whether they wish and are able to actualise them in their daily lives.
In 2003 a group of women involved with the Treatment Action Campaign and Medicines Sans Frontières participated in an initiative to ‘map’ their bodies as affected by the virus. A book containing the maps and narratives was published and used as a political tool to pressure the government of the day to roll out antiretroviral therapy (ART) to the population. In 2008, the authors coordinated an initiative that involved conducting follow-up in-depth interviews in which five of these women reflected on those body maps and on how their lives had changed in the intervening five years since gaining the right to treatment through the public sector.
Drawing upon this qualitative data and published sources, these new accounts are analysed in order to reflect the perspectives of these women living with chronic HIV with respect to their sexual relations and fertility desires. The paper reveals difficulties faced by these women in negotiating sexual relationships and disclosure of their HIV positive status. It focuses on how they perceive relative responsibilities in terms of taking preventative measures in sexual encounters. Women adopt tactics within a context characterised by various inequalities in order to ‘make do’, such as by remaining silent about their status. Concerns about childbearing can be addressed by information and support from a health care worker.
Women’s experience of HIV as a chronic illness and the need to adhere to ART, is linked to the way in which the language of responsibility can come to counter-balance a language of rights in treatment programmes.
PMCID: PMC3287463  PMID: 22376178
5.  Neurodevelopmental effects of chronic exposure to elevated levels of pro-inflammatory cytokines in a developing visual system 
Neural Development  2010;5:2.
Imbalances in the regulation of pro-inflammatory cytokines have been increasingly correlated with a number of severe and prevalent neurodevelopmental disorders, including autism spectrum disorder, schizophrenia and Down syndrome. Although several studies have shown that cytokines have potent effects on neural function, their role in neural development is still poorly understood. In this study, we investigated the link between abnormal cytokine levels and neural development using the Xenopus laevis tadpole visual system, a model frequently used to examine the anatomical and functional development of neural circuits.
Using a test for a visually guided behavior that requires normal visual system development, we examined the long-term effects of prolonged developmental exposure to three pro-inflammatory cytokines with known neural functions: interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α. We found that all cytokines affected the development of normal visually guided behavior. Neuroanatomical imaging of the visual projection showed that none of the cytokines caused any gross abnormalities in the anatomical organization of this projection, suggesting that they may be acting at the level of neuronal microcircuits. We further tested the effects of TNF-α on the electrophysiological properties of the retinotectal circuit and found that long-term developmental exposure to TNF-α resulted in enhanced spontaneous excitatory synaptic transmission in tectal neurons, increased AMPA/NMDA ratios of retinotectal synapses, and a decrease in the number of immature synapses containing only NMDA receptors, consistent with premature maturation and stabilization of these synapses. Local interconnectivity within the tectum also appeared to remain widespread, as shown by increased recurrent polysynaptic activity, and was similar to what is seen in more immature, less refined tectal circuits. TNF-α treatment also enhanced the overall growth of tectal cell dendrites. Finally, we found that TNF-α-reared tadpoles had increased susceptibility to pentylenetetrazol-induced seizures.
Taken together our data are consistent with a model in which TNF-α causes premature stabilization of developing synapses within the tectum, therefore preventing normal refinement and synapse elimination that occurs during development, leading to increased local connectivity and epilepsy. This experimental model also provides an integrative approach to understanding the effects of cytokines on the development of neural circuits and may provide novel insights into the etiology underlying some neurodevelopmental disorders.
PMCID: PMC2819242  PMID: 20067608

Results 1-6 (6)