The role of thyroid and steroid hormones in maturation of the adreline-sensitive reabsorptive mechanism of the fetal lung

Around the time of birth, the lung switches from a secretory- to a liquid absorptive organ to enable the fetus to transit from an intra-uterine to an air-breathing environment. This study concerns hormonal control of the liquid reabsorptive mechanism in the fetal lung which allows this transition to take place. Thyroidectomy in the fetal sheep at 118 days gestation (term = 147 days) prevented the development of adrenaline- or cyclic AMP-sensitivity which, in euthyroid fetuses, resulted in the capacity to absorb lung liquid from 130 days onwards. Studies in which T₃ and T₄ were infused to thyroidectornized fetal sheep showed that T₃ was required for the normal evolution of the reabsorptive response. However, infusion of this hormone to immature fetuses (110 days) did not advance the gestation at which adrenaline-sensitive absorption is first seen. Co-infusion of T₃ and hydrocortisone showed that these 2 hormones have a powerful synergistic effect on the absorption mechanism. Within a few hours of infusion of these 2 hormones to immature fetuses, a reabsorptive response to adrenaline similar to that normally seen in mature fetuses was observed. This response was fully reversible on withdrawal of T₃ and hydrocortisone infusion, and the hormonal effect was blocked by the protein synthesis inhibitor, cyclohexirnide. These findings suggest that the normal rise in T₃ and cortisol seen in the fetus in late gestation is responsible for maturation of the liquid absorption mechanism which allows the fetus to make a transition to an independent air-breathing existence. These observations may be of significance in the clinical management of infants born prematurely, who may have had insufficient pre-natal exposure to T₃ and cortisol

Managing HIV as a chronic disease: Using interactive data collection to improve clinical care

As South Africa and the rest of the developing world respond to the AIDS crisis, a critical task will be to develop scalable systems for sustainable and effective delivery of antiretroviral (ARV) drugs in a variety of resource-restricted settings. With the emergence, from national governments, the World Health Organization (WHO) and major international donors, of the political will and funding to support treatment programmes, it has become urgent that we consider how ARVs will be delivered. In this review, we consider how ARVs allow us to manage HIV/AIDS as a chronic disease, and the data systems that are required to support this approach to therapy. Southern African Journal of HIV Medicine Vol. 5(4) 2004: 7-1

Does postnatal care have a role in improving newborn feeding? A study in 15 sub–Saharan African countries

Breastfeeding is known as a key intervention to improve newborn health and survival while prelacteal feeds (liquids other than breastmilk within 3 days of birth) represents a departure from optimal feeding practices. Recent programmatic guidelines from the WHO and UNICEF outline the need to improve newborn feeding and points to postnatal care (PNC) as a potential mechanism to do so. This study examines if PNC and type of PNC provider are associated with key newborn feeding practices: breastfeeding within 1 day and prelacteal feeds

A framework for scaling up health interventions: lessons from large-scale improvement initiatives in Africa

BackgroundScaling up complex health interventions to large populations is not a straightforward task. Without intentional, guided efforts to scale up, it can take many years for a new evidence-based intervention to be broadly implemented. For the past decade, researchers and implementers have developed models of scale-up that move beyond earlier paradigms that assumed ideas and practices would successfully spread through a combination of publication, policy, training, and example.Drawing from the previously reported frameworks for scaling up health interventions and our experience in the USA and abroad, we describe a framework for taking health interventions to full scale, and we use two large-scale improvement initiatives in Africa to illustrate the framework in action. We first identified other scale-up approaches for comparison and analysis of common constructs by searching for systematic reviews of scale-up in health care, reviewing those bibliographies, speaking with experts, and reviewing common research databases (PubMed, Google Scholar) for papers in English from peer-reviewed and “gray” sources that discussed models, frameworks, or theories for scale-up from 2000 to 2014. We then analyzed the results of this external review in the context of the models and frameworks developed over the past 20years by Associates in Process Improvement (API) and the Institute for Healthcare improvement (IHI). Finally, we reflected on two national-scale improvement initiatives that IHI had undertaken in Ghana and South Africa that were testing grounds for early iterations of the framework presented in this paper.ResultsThe framework describes three core components: a sequence of activities that are required to get a program of work to full scale, the mechanisms that are required to facilitate the adoption of interventions, and the underlying factors and support systems required for successful scale-up. The four steps in the sequence include (1) Set-up, which prepares the ground for introduction and testing of the intervention that will be taken to full scale; (2) Develop the Scalable Unit, which is an early testing phase; (3) Test of Scale-up, which then tests the intervention in a variety of settings that are likely to represent different contexts that will be encountered at full scale; and (4) Go to Full Scale, which unfolds rapidly to enable a larger number of sites or divisions to adopt and/or replicate the intervention.ConclusionsOur framework echoes, amplifies, and systematizes the three dominant themes that occur to varying extents in a number of existing scale-up frameworks. We call out the crucial importance of defining a scalable unit of organization. If a scalable unit can be defined, and successful results achieved by implementing an intervention in this unit without major addition of resources, it is more likely that the intervention can be fully and rapidly scaled. When tying this framework to quality improvement (QI) methods, we describe a range of methodological options that can be applied to each of the four steps in the framework’s sequence

In Vivo Airway Surface Liquid Cl− Analysis with Solid-State Electrodes

The pathogenesis of cystic fibrosis (CF) airways disease remains controversial. Hypotheses that link mutations in CFTR and defects in ion transport to CF lung disease predict that alterations in airway surface liquid (ASL) isotonic volume, or ion composition, are critically important. ASL [Cl−] is pivotal in discriminating between these hypotheses, but there is no consensus on this value given the difficulty in measuring [Cl−] in the “thin” ASL (∼30 μm) in vivo. Consequently, a miniaturized solid-state electrode with a shallow depth of immersion was constructed to measure ASL [Cl−] in vivo. In initial experiments, the electrode measured [Cl−] in physiologic salt solutions, small volume (7.6 μl) test solutions, and in in vitro cell culture models, with ≥93% accuracy. Based on discrepancies in reported values and/or absence of data, ASL Cl− measurements were made in the following airway regions and species. First, ASL [Cl−] was measured in normal human nasal cavity and averaged 117.3 ± 11.2 mM (n = 6). Second, ASL [Cl−] measured in large airway (tracheobronchial) regions were as follows: rabbit trachea and bronchus = 114.3 ± 1.8 mM; (n = 6) and 126.9 ± 1.7 mM; (n = 3), respectively; mouse trachea = 112.8 ± 4.2 mM (n = 13); and monkey bronchus = 112.3 ± 10.9 mM (n = 3). Third, Cl− measurements were made in small (1–2 mm) diameter airways of the rabbit (108.3 ± 7.1 mM, n = 5) and monkey (128.5 ± 6.8 mM, n = 3). The measured [Cl−], in excess of 100 mM throughout all airway regions tested in multiple species, is consistent with the isotonic volume hypothesis to describe ASL physiology

Using quality improvement to accelerate highly active antiretroviral treatment coverage in South Africa

IntroductionThe authors report on a health systems strengthening intervention using quality improvement (QI) methods at the subdistrict level to accelerate highly active antiretroviral treatment (HAART) initiation in South Africa.MethodsUsing a phased scale-up design between August 2006 and November 2009, 14 primary healthcare clinics, one community health centre, one district hospital and one tertiary hospital in a subdistrict were recruited into a ‘learning network’ using QI methods to facilitate cross-facility learning/mentorship/support. Clinic teams consisting of nurses, counsellors, clerks and/or doctors set collective and individual performance targets, analysed their care systems using ‘real-time’ data feedback, and designed/implemented a set of simple changes to improve HIV testing and HAART initiation rates across the region.Data analysisPrimary clinic data were used to measure HAART initiation rates (primary outcome) and HIV testing (secondary outcome). We analysed data variation/trends using an interrupted time series design. Logistic regression analysis was applied to examine trends in HAART initiation during the intervention phases.ResultsClinics in the learning network increased HIV testing by 301.8% from 891/month (SD=94.2) to 3580/month (SD=327.7) (p<0.0001). Monthly HAART initiations increased by 185.5% from 179/month (SD=17.22) to 511/month (SD=44.93) (p<0.0001). During the pilot (phase I), the monthly rate of HAART initiations increased by 3.6 patients. In the prototype collaborative (phase II), there was no acceleration in the rate of increase (3.3/month, p=0.92). Significant acceleration was observed in the rate of increase during the QI scale up (phase III) (10.1/month, p<0.001). The proportion of estimated need for HAART met in the region increased from 35.8% to 72.4% at a time of rapid population growth.ConclusionA QI approach, using learning networks to teach simple data-driven methods for addressing system failures, with increased training and resource inputs, can assist districts to quickly reach universal coverage targets

Anomalous quantum confined Stark effects in stacked InAs/GaAs self-assembled quantum dots

Vertically stacked and coupled InAs/GaAs self-assembled quantum dots (SADs) are predicted to exhibit a strong non-parabolic dependence of the interband transition energy on the electric field, which is not encountered in single SAD structures nor in other types of quantum structures. Our study based on an eight-band strain-dependent ${\bf k}\cdot{\bf p}$ Hamiltonian indicates that this anomalous quantum confined Stark effect is caused by the three-dimensional strain field distribution which influences drastically the hole states in the stacked SAD structures.Comment: 4 pages, 4 figure

The habitus and the critique of the present. A Wittgensteinian reading of Bourdieu’s social theory

I tackle some major criticisms addressed to Pierre Bourdieu’s notion of habitus by foregrounding its affinities with Ludwig Wittgenstein’s notion of rule-following. To this end, I first clarify the character of the habitus as a theoretical device, and then elucidate what features of Wittgenstein’s analysis Bourdieu found of interest from a methodological viewpoint. To vindicate this reading, I contend that Wittgenstein’s discussion of rule-following was meant to unearth the internal connection between rules and the performative activities whereby rules are brought into life. By portraying rules as tools that allow agents to stabilize and renegotiate practices, I illustrate the active role social agents play in the production of shared accounts of practices. I conclude by showing that, if viewed through this prism, the habitus proves to be meant to provide guidance on how social theory helps historicize and denaturalize the social world