Infant feeding practices in a high HIV prevalence rural district of KwaZulu-Natal, South Africa

Aim: To describe infant feeding practices at birth and at 14 weeks post-partum in the Ugu-North Health District, KwaZulu-Natal, South Africa.Methods: A prospective, cohort study design was used. Mothers who delivered over a one-month period were interviewed at birth and14 weeks later. Results: Initially, 168 mothers were interviewed within 24 hours of delivery, of whom 117 (70%) were contactable at 14 weeks post-partum. The vast majority (96%) initiated breast-feeding at birth. At birth, less than one-third (55/168 [32.7%]) of mothers declared an intention to both breast and formula (mix) feed in the next 14 weeks, but by the 14th week post-partum over three-quarters (89/117 [76.1%]) actually practised mixed feeding. At 14 weeks, the prevalence of exclusive breast-feeding was 18%: 52% of infants were offered water and 73% solids. The majority (20/23 [87%]) of HIV infected mothers chose to breastfeed their infants at birth. Nevertheless, they were significantly more likely to formula feed their infants compared to HIV negative mothers (3/23 [13.0%] vs 2/145 [1.4%], OR 10.73, 95% CI 1.34 – 99.16, p = 0.02). By 14 weeks, only 11% of HIV positive mothers were still exclusively breast-feeding, while almost two-thirds (12/19 [63%]) practised mixed feeding. This change was mainly ascribed to their need to return to school (40%) or to work (20%). Conclusions: Most infants were fed inappropriately by 14 weeks of age. The failure to maintain exclusive breast-feeding, despite high initiation rates, is of greatest concern. Routine prevention of mother-to-child transmission of HIV services was ineffective in influencing mothers to follow any feeding regimen exclusively

The Mycobacterium tuberculosis Drugome and Its Polypharmacological Implications

We report a computational approach that integrates structural bioinformatics, molecular modelling and systems biology to construct a drug-target network on a structural proteome-wide scale. The approach has been applied to the genome of Mycobacterium tuberculosis (M.tb), the causative agent of one of today's most widely spread infectious diseases. The resulting drug-target interaction network for all structurally characterized approved drugs bound to putative M.tb receptors, we refer to as the ‘TB-drugome’. The TB-drugome reveals that approximately one-third of the drugs examined have the potential to be repositioned to treat tuberculosis and that many currently unexploited M.tb receptors may be chemically druggable and could serve as novel anti-tubercular targets. Furthermore, a detailed analysis of the TB-drugome has shed new light on the controversial issues surrounding drug-target networks [1]–[3]. Indeed, our results support the idea that drug-target networks are inherently modular, and further that any observed randomness is mainly caused by biased target coverage. The TB-drugome (http://funsite.sdsc.edu/drugome/TB) has the potential to be a valuable resource in the development of safe and efficient anti-tubercular drugs. More generally the methodology may be applied to other pathogens of interest with results improving as more of their structural proteomes are determined through the continued efforts of structural biology/genomics

Understanding the trade-off between the environment and fertility in cows and ewes.

The environment contributes to production diseases that in turn badly affect cow performance, fertility and culling. Oestrus intensity is lower in lame cows, and in all cows 26% potential oestrus events are not expressed (to avoid getting pregnant). To understand these trade-offs, we need to know how animals react to their environment and how the environment influences hypothalamus-pituitary-adrenal axis (HPA) interactions with the hypothalamus-pituitary-ovarian axis (HPO). Neurotransmitters control secretion of GnRH into hypophyseal portal blood. GnRH/LH pulse amplitude and frequency drive oestradiol production, culminating in oestrus behaviour and a precisely-timed GnRH/LH surge, all of which are disrupted by poor environments. Responses to peripheral neuronal agents give clues about mechanisms, but do these drugs alter perception of stimuli, or suppress consequent responses? In vitro studies confirm some neuronal interactions between the HPA and HPO; and immuno-histochemistry clarifies the location and sequence of inter-neurone activity within the brain. In both species, exogenous corticoids, ACTH and/or CRH act at the pituitary (reduce LH release by GnRH), and hypothalamus (lower GnRH pulse frequency and delay surge release). This requires inter-neurones as GnRH cells do not have receptors for HPA compounds. There are two (simultaneous, therefore fail-safe?) pathways for CRH suppression of GnRH release via CRH-Receptors: one being the regulation of kisspeptin/dynorphin and other cell types in the hypothalamus, and the other being the direct contact between CRH and GnRH cell terminals in the median eminence. When we domesticate animals, we must provide the best possible environment otherwise animals trade-off with lower production, less intense oestrus behaviour, and impaired fertility. Avoiding life-time peri-parturient problems by managing persistent lactations in cows may be a worthy trade-off on both welfare and economic terms - better than the camouflage use of drugs/hormones/feed additives/intricate technologies? In the long term, getting animals and environment in a more harmonious balance is the ultimate strategy