Medical Anthropology: Toward a Third Moment in Social Science?

This article about medical anthropology was inspired by the work of Pierre Bourdieu, specifically, his efforts to reconcile the antinomy of a "social structuralist" and a "cultural constructivist" perspective. These perspectives are often opposed in the literature, but, in Bourdieu's view, human life cannot be studied without taking into account both how individuals are situated within and constrained by social structures and how those individuals construct an understanding of and impose meaning on the world around them. I argue that the special subject matter of medical anthropology--human health--demands that a synthetic approach be taken in our theory and research. I illustrate this argument with examples from my own research on social and cultural factors associated with blood pressure, and I point to other examples of this synthesis in medical anthropology. The results of this research hold promise for the continuing refinement of culture theory.     

Sylvatic Plague Vaccine: A New Tool for Conservation of Threatened and Endangered Species?

Plague, a disease caused by Yersinia pestis introduced into North America about 100?years ago, is devastating to prairie dogs and the highly endangered black-footed ferret. Current attempts to control plague in these species have historically relied on insecticidal dusting of prairie dog burrows to kill the fleas that spread the disease. Although successful in curtailing outbreaks in most instances, this method of plague control has significant limitations. Alternative approaches to plague management are being tested, including vaccination. Currently, all black-footed ferret kits released for reintroduction are vaccinated against plague with an injectable protein vaccine, and even wild-born kits are captured and vaccinated at some locations. In addition, a novel, virally vectored, oral vaccine to prevent plague in wild prairie dogs has been developed and will soon be tested as an alternative, preemptive management tool. If demonstrated to be successful, oral vaccination of selected prairie dog populations could decrease the occurrence of plague epizootics in key locations, thereby reducing the source of bacteria while avoiding the indiscriminate environmental effects of dusting. Just as rabies in wild carnivores has largely been controlled through an active surveillance and oral vaccination program, we believe an integrated plague management strategy would be similarly enhanced with the addition of a cost-effective, bait-delivered, sylvatic plague vaccine for prairie dogs. Control of plague in prairie dogs, and potentially other rodents, would significantly advance prairie dog conservation and black-footed ferret recovery.     

Dental Status of New Caledonian Children: Is There a Need for a New Oral Health Promotion Programme?

Background

Before implementing a new oral health promotion program in the French overseas territory of Nouvelle Calédonie, the health authorities needed recent data about dental status of the New Caledonian child population.

Objectives

This study aimed to describe the dental status of 6, 9 and 12-yr-old New Caledonian children and to investigate the environmental and behavioural risk factors related to oral health.

Methods

A randomly selected sample of 2734 children (744 6-yr-olds, 789 9-yr-olds, and 1201 12-yr-olds) was examined clinically by seven calibrated investigators and participants responded to a questionnaire. The main variables were objective criteria about dental status and subjective criteria about experience of dental care, dental fear, self-perception of oral health, cultural or ethnic identity and environmental and behavioural risk factors.

Results

Overall, most of the children had infectious oral diseases: more than 50% had gingivitis, and 60% of 6- and 9 yr-olds had at least one deciduous or permanent tooth with untreated caries. The mean 12-yr-old number of decayed missing and filled teeth (DMFT) was 2.09±2.82. The number of carious lesions was related to the unfavourable lifestyle, deprived social status and no preventive dental care. Kanak, Polynesians and Caledonians (respectively 27%, 18% and 45% of the study sample) were more affected by caries than metropolitan French and Asian children. Children with many untreated carious lesions had negative perceptions of their oral health; they complained of chewing difficulty and had higher scores for dental anxiety.

Conclusion

This study highlights the need for new strategies aimed at improving oral health and at reducing inequalities in New Caledonia. An oral health promotion program would need to be developed in connection with other health programmes using the common risk factor approach within the context of the local environment.     

Possession and Usage of Insecticidal Bed Nets among the People of Uganda: Is BRAC Uganda Health Programme Pursuing a Pro-Poor Path?

Background

The use of insecticidal bed nets is found to be an effective public health tool for control of malaria, especially for under-five children and pregnant women. BRAC, an indigenous Bangladeshi non-governmental development organization, started working in the East African state of Uganda in June 2006. As part of its efforts to improve the health and well-being of its participants, BRAC Uganda has been distributing long lasting insecticide-treated bed nets (LLIN) at a subsidized price through health volunteers since February 2008. This study was conducted in March-April 2009 to examine how equitable the programme had been in consistence with BRAC Uganda''s pro-poor policy.

Methodology/Principal Findings

Information on possession of LLINs and relevant knowledge on its proper use and maintenance was collected from households either with an under-five child and/or a pregnant woman. The sample included three villages from each of the 10 branch offices where BRAC Uganda''s community-based health programme was operating. Data were collected by trained enumerators through face-to-face interviews using a hand-held personal digital assistant (PDA). Findings reveal that the study population had superficial knowledge on malaria and its transmission, including the use and maintenance of LLINs. The households'' rate of possession of bed nets (41–59%), and the proportion of under-five children (17–19%) and pregnant women (25–27%) who reported sleeping under an LLIN were not encouraging. Inequity was observed in the number of LLINs possessed by the households, in the knowledge on its use and maintenance, and between the two programme areas.

Conclusions/Significance

The BRAC Uganda''s LLINs distribution at a subsidized price appeared to be inadequate and inequitable, and BRAC''s knowledge dissemination is insufficient for initiating preventive actions such as proper use of LLINs to interrupt malaria transmission. Findings contribute to the on-going debate on LLINs distribution in Africa and make a strong case for its free distribution.     

Evolution of Cryptococcal Antigen Testing: What Is New?

Over the last decade, an upsurge in both the frequency and severity of fungal infections due to the HIV/AIDS epidemic and the use of immunosuppressive therapy has occurred. Even diagnostic methods like culture and microscopy, which have low sensitivity and longer turnaround times, are not widely available, leading to delays in timely antifungal therapy and detrimental patient outcomes. The evolution of cryptococcal antigen (CrAg) testing to develop inexpensive and more sensitive methods to detect cryptococcal antigen is significant. These newer tests employ immunoassays as part of point-of-care platforms, which do not require complex laboratory infrastructure, and they have the potential to detect early disease and reduce time to diagnosis of cryptococcal infection. Advocacy for widely available and efficacious life-saving antifungal treatment should be the only remaining challenge.     

Turning a Drug Target into a Drug Candidate: A New Paradigm for Neurological Drug Discovery?

The conventional paradigm for developing new treatments for disease mainly involves either the discovery of new drug targets, or finding new, improved drugs for old targets. However, an ion channel found only in invertebrates offers the potential of a completely new paradigm in which an established drug target can be re-engineered to serve as a new candidate therapeutic agent. The L-glutamate-gated chloride channels (GluCls) of invertebrates are absent from vertebrate genomes, offering the opportunity to introduce this exogenous, inhibitory, L-glutamate receptor into vertebrate neuronal circuits either as a tool with which to study neural networks, or a candidate therapy. Epileptic seizures can involve L-glutamate-induced hyper-excitation and toxicity. Variant GluCls, with their inhibitory responses to L-glutamate, when engineered into human neurons, might counter the excitotoxic effects of excess L-glutamate. In reviewing recent studies on model organisms, it appears that this approach might offer a new paradigm for the development of candidate therapeutics for epilepsy.     

Conservatism and Adaptability during Squirrel Radiation: What Is Mandible Shape Telling Us?

Both functional adaptation and phylogeny shape the morphology of taxa within clades. Herein we explore these two factors in an integrated way by analyzing shape and size variation in the mandible of extant squirrels using landmark-based geometric morphometrics in combination with a comparative phylogenetic analysis. Dietary specialization and locomotion were found to be reliable predictors of mandible shape, with the prediction by locomotion probably reflecting the underlying diet. In addition a weak but significant allometric effect could be demonstrated. Our results found a strong phylogenetic signal in the family as a whole as well as in the main clades, which is in agreement with the general notion of squirrels being a conservative group. This fact does not preclude functional explanations for mandible shape, but rather indicates that ancient adaptations kept a prominent role, with most genera having diverged little from their ancestral clade morphologies. Nevertheless, certain groups have evolved conspicuous adaptations that allow them to specialize on unique dietary resources. Such adaptations mostly occurred in the Callosciurinae and probably reflect their radiation into the numerous ecological niches of the tropical and subtropical forests of Southeastern Asia. Our dietary reconstruction for the oldest known fossil squirrels (Eocene, 36 million years ago) show a specialization on nuts and seeds, implying that the development from protrogomorphous to sciuromorphous skulls was not necessarily related to a change in diet.     

New 2-arylnaphthalenediols and triol inhibitors of HIV-1 integrase—Discovery of a new polyhydroxylated antiviral agent

A series of 13 hydroxylated 2-arylnaphthalenes have been synthesized and evaluated as HIV-1 integrase inhibitors. 7-(3,4,5-Trihydroxyphenyl)naphthalene-1,2,3-triol 1c revealed chemical instability upon storage, leading to the isolation of a dimer 5c which was also tested. In the 2-arylnaphthalene series, all compounds were active against HIV-1 IN with IC₅₀’s within the 1–10 μM range, except for 1c and 5c which displayed submicromolar activity. Antiviral activity against HIV-1 replication was measured on 1b–c and 5c. Amongst the tested molecules, only 5c was found to present antiviral properties with a low cytotoxicity on two different cell lines.     

Development and Evaluation of Chitosan-Coated Liposomes for Oral DNA Vaccine: The Improvement of Peyer’s Patch Targeting Using a Polyplex-Loaded Liposomes

The aim of this study was to develop chitosan-coated and polyplex-loaded liposomes (PLLs) containing DNA vaccine for Peyer’s patch targeting. Plain liposomes carrying plasmid pRc/CMV-HBs were prepared by the reverse-phase evaporation method. Chitosan coating was carried out by incubation of the liposomal suspensions with chitosan solution. Main lipid components of liposomes were phosphatidylcholine/cholesterol. Sodium deoxycholate and dicetyl phosphate were used as negative charge inducers. The zeta potentials of plain liposomes were strongly affected by the pH of the medium. Coating with chitosan variably increased the surface charges of the liposomes. To increase the zeta potential and stability of the liposome, chitosan was also used as a DNA condensing agent to form a polyplex. The PLLs were coated with chitosan solution. In vivo study of PLLs was carried out in comparison with chitosan-coated liposomes using plasmid encoding green fluorescence protein as a reporter. A single dose of plasmid equal to 100 μg was intragastrically inoculated into BALB/c mice. The expression of green fluorescence protein (GFP) was detected after 24 h using a confocal laser scanning microscope. The signal of GFP was obtained from positively charged chitosan-coated liposomes but found only at the upper part of duodenum. With chitosan-coated PLL540, the signal of GFP was found throughout the intestine. Chitosan-coated PLL demonstrated a higher potential to deliver the DNA to the distal intestine than the chitosan-coated liposomes due to the increase in permanent positive surface charges and the decreased enzymatic degradation.     

Development of a Microfluidic Culture Paradigm for Ex Vivo Maintenance of Human Glioblastoma Tissue: A New Glioblastoma Model?

BACKGROUND: One way to overcome the genetic and molecular variations within glioblastoma is to treat each tumour on an individual basis. To facilitate this, we have developed a microfluidic culture paradigm that maintains human glioblastoma tissue ex vivo. METHODS: The assembled device, fabricated using a photolithographic process, is composed of two layers of glass bonded together to contain a tissue chamber and a network of microchannels that allow continued tissue perfusion. RESULTS: A total of 128 tissue biopsies (from 33 patients) were maintained in microfluidic devices for an average of 72 hours. Tissue viability (measured with Annexin V and propidium iodide) was 61.1% in tissue maintained on chip compared with 68.9% for fresh tissue analysed at commencement of the experiments. Other biomarkers, including lactate dehydrogenase absorbance and trypan blue exclusion, supported the viability of the tissue maintained on chip. Histological appearances remained unchanged during the tissue maintenance period, and immunohistochemical analysis of Ki67 and caspase 3 showed no significant differences when compared with fresh tissues. A trend showed that tumours associated with poorer outcomes (recurrent tumours and Isocitrate Dehydrogenase - IDH wildtype) displayed higher viability on chip than tumours linked with improved outcomes (low-grade gliomas, IDH mutants and primary tumours). conclusions: This work has demonstrated for the first time that human glioblastoma tissue can be successfully maintained within a microfluidic device and has the potential to be developed as a new platform for studying the biology of brain tumours, with the long-term aim of replacing current preclinical GBM models and facilitating personalised treatments.     

LifeMap Discovery?: The Embryonic Development,Stem Cells,and Regenerative Medicine Research Portal

LifeMap Discovery™ provides investigators with an integrated database of embryonic development, stem cell biology and regenerative medicine. The hand-curated reconstruction of cell ontology with stem cell biology; including molecular, cellular, anatomical and disease-related information, provides efficient and easy-to-use, searchable research tools. The database collates in vivo and in vitro gene expression and guides translation from in vitro data to the clinical utility, and thus can be utilized as a powerful tool for research and discovery in stem cell biology, developmental biology, disease mechanisms and therapeutic discovery. LifeMap Discovery is freely available to academic nonprofit institutions at http://discovery.lifemapsc.com     

Hormonal therapies and meningioma: Is there a link?

Background: The aetiology of meningiomas is largely unknown although hormones have been suggested to play a role. Methods: A cohort study was performed to evaluate hormone-related factors associated with meningioma. Patients (12–89 years) with a first diagnosis of meningioma (January 1996–June 2008) were identified from The Health Improvement Network UK primary care database and age- and sex-matched to controls (n = 10 000) from the same cohort. Odds ratios (ORs) were calculated following a nested case control analysis using unconditional logistic regression. Results: In total, 745 patients with meningioma were identified from a study population of 2 171 287. No significantly increased risk of meningioma was found among female users of oral contraceptives (OR: 1.15; CI: 0.67–1.98), hormone replacement therapy (OR: 0.99; CI: 0.73–1.35) or low-dose cyproterone acetate (CPA; OR: 1.51; CI: 0.33–6.86) compared with non-users. There was a significantly increased risk of meningioma among male users of androgen analogues (OR: 19.09; CI: 2.81–129.74) and among users of high-dose CPA (OR: 6.30; CI: 1.37–28.94) compared with non-users, however there were only three cases currently using these drugs. No significant association was found between meningioma and prostate, breast, or genital cancers. Conclusions: Our results do not support a role for exogenous hormone use by females in meningioma development. The risk in males was only observed with high-dose, short-term (<1 year) therapy. Impact: While hormonal cancers and therapies are not associated with meningioma in females, the risk in males requires further investigation.