Comparison of dietary assessment methods in nutritional epidemiology: weighed records v. 24 h recalls, food-frequency questionnaires and estimated-diet records

Women (n 160) aged 50 to 65 years were asked to weigh their food for 4 d on four occasions over the period of 1 year, using the PETRA (Portable Electronic Tape Recorded Automatic) scales. Throughout the year, they were asked to complete seven other dietary assessment methods: a simple 24 h recall, a structured 24 h recall with portion size assessments using photographs, two food-frequency questionnaires, a 7 d estimated record or open-ended food diary, a structured food-frequency (menu) record, and a structured food-frequency (menu) record with portion sizes assessed using photographs. Comparisons between the average of the 16 d weighed records and the first presentation of each method indicated that food-frequency questionnaires were not appreciably better at placing individuals in the distribution of habitual diet than 24 h recalls, due partly to inaccuracies in the estimation of frequency of food consumption. With a 7 d estimated record or open-ended food diary, however, individual values of nutrients were most closely associated with those obtained from 16 d weighed records, and there were no significant differences in average food or nutrient intakes.

The therapeutic design of environments for people with dementia: a review of the empirical research

Design of the physical environment is increasingly recognized as an important aid in caring for people with dementia. This article reviews the empirical research on design and dementia, including research concerning facility planning (relocation, respite and day care, special care units, group size), research on environmental attributes (noninstitutional character, sensory stimulation, lighting, safety), studies concerning building organization (orientation, outdoor space), and research on specific rooms and activity spaces (bathrooms, toilet rooms, dining rooms, kitchens, and resident rooms). The analysis reveals major themes in research and characterizes strengths and shortcomings in methodology, theoretical conceptualization, and applicability of findings.

Male mentally handicapped sex offenders

BACKGROUND

Sex offences are overrepresented in the mentally handicapped, but information about the characteristics and offence behaviour of this group is limited.

METHOD

A retrospective case note survey was made of 47 male patients referred for antisocial sexual behaviour.

RESULTS

Of 191 offences and/or incidents committed, 55.5% were heterosexual, 24% indecent exposure, 12.4% homosexual, 13.6% serious and 3.6% involved physical assault. Average age of the offenders was 23.9 years, with a mean IQ of 59.5, and there was a high prevalence of family psychopathology, psychiatric illness, minor physical disabilities, sexual experience, impaired relationship skills and sexual recidivism. Recidivists showed a low specificity for offence type and age and sex of victim. Categorical analysis differentiated a 'sex offences only' group from a 'sex plus other offences' group in the key areas of psychopathology, offence behaviour and outcome; this was supported by factor analysis.

CONCLUSION

The finding of two subgroups of mentally handicapped male sex offenders has important implications for prevention, assessment and treatment.

Psychiatric disorder in the middle-aged and elderly mentally handicapped

In a study of 357 long-stay hospital residents aged 40 years and over, 30% had significant psychiatric disorder, while a retrospective survey of 215 new admissions over a seven-year period to a psychiatric unit for the mentally handicapped revealed that 20% of patients were aged 40 years and over. Both similarities and differences were found in the overall pattern of disorders between the two groups and a non-handicapped population in a comparable age-range.

Defining the transcriptional signature of skeletal muscle stem cells

Satellite cells, the main source of myoblasts in postnatal muscle, are located beneath the myofiber basal lamina. The myogenic potential of satellite cells was initially documented based on their capacity to produce progeny that fused into myotubes. More recently, molecular markers of resident satellite cells were identified, further contributing to defining these cells as myogenic stem cells that produce differentiating progeny and self-renew. Herein, we discuss aspects of the satellite cell transcriptional milieu that have been intensively investigated in our research. We elaborate on the expression patterns of the paired box (Pax) transcription factors Pax3 and Pax7, and on the myogenic regulatory factors myogenic factor 5 (Myf5), myogenic determination factor 1 (MyoD), and myogenin. We also introduce original data on MyoD upregulation in newly activated satellite cells, which precedes the first round of cell proliferation. Such MyoD upregulation occurred even when parent myofibers with their associated satellite cells were exposed to pharmacological inhibitors of hepatocyte growth factor and fibroblast growth factor receptors, which are typically involved in promoting satellite cell proliferation. These observations support the hypothesis that most satellite cells in adult muscle are committed to rapidly entering myogenesis. We also detected expression of serum response factor in resident satellite cells prior to MyoD expression, which may facilitate the rapid upregulation of MyoD. Aspects of satellite cell self-renewal based on the reemergence of cells expressing Pax7, but not MyoD, in myogenic cultures are discussed further herein. We conclude by describing our recent studies using transgenic mice in which satellite cells are traced and isolated based on their expression of green fluorescence protein driven by regulatory elements of the nestin promoter (nestin-green fluorescence protein). This feature provides us with a novel means of studying satellite cell transcriptional signatures, heterogeneity among muscle groups, and the role of the myogenic niche in directing satellite cell self-renewal.

A hospital-based treatment programme for male mentally handicapped offenders

The paper describes a special hospital-based treatment programme for male mentally handicapped offenders, comprising a package of practical and personal skills training coupled with a socialisation programme based on token-economy strategies within a controlled and structured environment. Twenty patients admitted to the programme and followed up after discharge for an average of 3.3 years were studied in detail. All had committed serious or persistent offences and showed a high level of psychosocial pathology. A good or fair response to the treatment programme was made by 85%, and 65% were judged well adjusted or reasonably well adjusted at last follow-up contact. A good outcome was associated with more than two years' in-patient care, a good response to the treatment programme and stable residential placement, regular occupation and regular supervision and support in the community. Offenders against the person (sex and assault) had a better prognosis than and showed other interesting differences from property offenders (property and arson).

The correlation between the intake of lutein, lycopene and beta-carotene from vegetables and fruits, and blood plasma concentrations in a group of women aged 50-65 years in the UK

The correlations between the mean of 4 d weighed intakes of lutein, lycopene and beta-carotene and mean plasma concentrations during each of the four seasons were lutein r 0.64, lycopene r 0.47 and beta-carotene r 0.45. Intake was not significantly correlated with plasma concentrations during every seasonal time-point. There was a significantly higher intake of lutein during the spring compared with summer and autumn, lycopene intake was significantly higher during the summer and autumn and there were no significant seasonal differences in beta-carotene intake. There were, however, significant seasonal differences in plasma carotenoid concentrations, the highest levels occurring between May and October. There were large inter- and intra-individual variations in intake and plasma concentrations of carotenoids. BMI was inversely correlated with plasma beta-carotene (r-0.41). The findings suggest that plasma carotenoid concentrations are indicative of dietary intake, but the large intra-individual variation in plasma concentrations indicates that any assessment of longer-term status from data at any one time-point should be treated with caution.

Angiogenic growth factor messenger ribonucleic acids in uterine natural killer cells

Angiogenesis is essential for endometrial growth and repair, and disruption of this process may lead to common disorders of women, including menorrhagia and endometriosis. In pregnancy, failure of the endometrial spiral arterioles to undergo remodeling leads to preeclampsia. Here we report that in addition to vascular endothelial growth factor A (VEGF-A), human endometrium expresses messenger ribonucleic acids (mRNAs) encoding VEGF-C, placenta growth factor (PlGF), the angiopoietins, angiopoietin 1 (Ang1) and Ang2, and the receptors VEGFR-3 (Flt-4), Tie 1, and Tie 2. Levels of VEGF-C, PlGF, and Tie 2 changed during the menstrual cycle. Intense hybridization for VEGF-C and PlGF mRNAs was found in uterine nature killer cells in secretory phase endometrium and for Ang2 mRNA in the same cells in the late secretory phase. Interleukin-2 (IL-2) and IL-15 up-regulated VEGF-C, but not PlGF or Ang2, mRNA levels in isolated NK cells. Conditioned medium from decidual NK cells did not induce human umbilical vein endothelial cell apoptosis. These results indicate that human endometrium expresses a wide range of angiogenic growth factors and that uterine nature killer cells may play an important role in the abnormal endometrial angiogenesis that underlies a range of disorders affecting women.

Apolipoprotein E epsilon 2 allele promotes longevity and protects patients with Down's syndrome from dementia

Although individuals with Down's syndrome nearly always develop the clinical and pathological features of Alzheimer's disease, some clearly do not become demented despite living into their sixth and seventh decades. Genetic variation at the apolipoprotein E locus has recently been shown to be an important determinant of Alzheimer's disease, with the epsilon 4 allele having been shown to be associated with the disease and, at least in some cases, the epsilon 2 allele being negatively associated with the disease. Here we show, in a series of clinically assessed individuals with Down's syndrome, that the epsilon 2 allele of ApoE is associated with both longevity and the absence of clinical evidence of dementia. These data show that the clinical phenotype of Down's syndrome can be modulated by genes on chromosomes other than chromosome 21. The importance of this observation to the pathogenesis of Alzheimer's disease, both in Down's syndrome and in general, is discussed.

Plasmodium falciparum: parasites defective in early stages of gametocytogenesis

Some molecular characteristics of Plasmodium falciparum lines which do not produce gametocytes are described. Parasites carrying a subtelomerically deleted chromosome 9 cannot form even the earliest forms of gametocytes, detectable with antibodies against the gametocyte-specific antigen Pfg27. In a parasite culture of clone HB3, in which both intact and deleted forms of chromosome 9 are present, full-length chromosome 9 molecules are retained mainly in gametocytes. These data suggest that the subtelomeric portion of chromosome 9 is required at an early stage of gametocytogenesis. Parasite subclones derived from gametocyte producing clone 3D7, which completely lost ability to produce gametocytes, are also described. Unlike the previous gametocyteless lines, these parasites stably maintain a full-length chromosome 9 and the ability to cytoadhere to C32 melanoma cells after prolonged asexual propagation. Their defect in sexual development is therefore genetically and functionally distinct from that of parasites carrying a deleted chromosome 9. Gametocyteless subclones derived from 3D7 do not produce any Pfg27 mRNA, while this gene is anomalously expressed in asexual stage parasites of two lines of a different genetic background, 1776sel8 and C10, one able and the other unable to produce gametocytes.

Randomised crossover study of the Flutter device and the active cycle of breathing technique in non-cystic fibrosis bronchiectasis

BACKGROUND

Airway clearance techniques are an important part of the routine care of patients with bronchiectasis. The use of the Flutter, a hand held pipe-like device causing oscillating positive expiratory pressure within the airways, has been proposed as an alternative to more conventional airway clearance techniques.

METHODS

A randomised crossover study was performed in 17 stable patients with non-cystic fibrosis bronchiectasis at home, in which 4 weeks of daily active cycle of breathing technique (ACBT) were compared with 4 weeks of daily physiotherapy with the Flutter device.

RESULTS

No significant differences between the two techniques were found. Median weekly sputum weights were similar with a median treatment difference of 7.64 g (p=0.77) and there was no evidence of treatment order or order interaction effects (p=0.70). Health status (Chronic Respiratory Disease Questionnaire) and ventilatory function did not change significantly during either treatment period. There was no significant change in peak expiratory flow rate or in breathlessness (Borg score) after individual physiotherapy sessions with either technique. A questionnaire indicated subjectively that patients preferred the Flutter (11/17) to ACBT for routine use.

CONCLUSIONS

Daily use of the Flutter device in the home is as effective as ACBT in patients with non-cystic fibrosis bronchiectasis, and has a high level of patient acceptability.

Comparison of single-dose diethylcarbamazine and ivermectin for treatment of bancroftian filariasis in Papua New Guinea

This double-blind study compared the clinical safety and parasitologic efficacy of single-dose regimens of diethylcarbamazine (DEC) and ivermectin for treatment of bancroftian filariasis in Papua New Guinea. Five groups of 10 men each with mean levels of parasitemia ranging from 2,985 to 5,185 microfilariae (mf)/ml were given DEC (6 mg/kg of body weight one time or 1 mg/kg, then 6 mg/kg four days later) or ivermectin (220 micrograms/kg; 20 micrograms/kg, then 200 micrograms/kg four days later or 20 micrograms/kg, then 400 micrograms/kg four days later). No significant side effects (e.g., acute adenolymphangitis, fever lasting more than eight hours, hypotension) were observed in any of the five treatment groups. The magnitude of reduction in microfilaremia was greater (P < 0.01) for the three ivermectin groups versus the two DEC groups in the first 30 days after drug administration (mf levels < 1% of pretreatment values versus 22.6-41.5%, respectively). At 90 and 180 days, mf levels continued to decrease in the DEC groups whereas they increased in the ivermectin groups given a total dose of 220 micrograms/kg. Eighteen months after drug administration, individuals given DEC or 420 micrograms/kg of ivermectin had the greatest degree of reduction in microfilaremia (86-90% compared with the pretreatment values). Decreases in parasite antigenemia measured by enzyme-linked immunosorbent assay for a secreted 200-kD adult worm antigen were greatest for the single-dose DEC group (39.7% decrease relative to the pretreatment level versus 7.8-15.7% for the ivermectin groups). These results indicate that single-dose DEC and ivermectin are well-tolerated by Wuchereria bancrofti-infected individuals with high levels of microfilaremia.(ABSTRACT TRUNCATED AT 250 WORDS)

A CD2-green fluorescence protein-transgenic mouse reveals very late antigen-4-dependent CD8+ lymphocyte rolling in inflamed venules

Intravital microscopy allows detailed analysis of leukocyte trafficking in vivo, but fails to identify the nature of leukocytes investigated. Here, we describe the development of a CD2-enhanced green fluorescence protein (EGFP)-transgenic mouse to characterize lymphocyte trafficking during inflammation in vivo. A CD2-EGFP plasmid construct including the CD2 promoter, the EGFP transgene, and the CD2 locus control region was injected into B6CBA/F1 pronuclei. EGFP+ offspring were backcrossed into C57BL/6 mice for six generations. Flow cytometry demonstrated that all peripheral blood EGFP+ cells were positive for CD2 and negative for the granulocyte Ag Ly 6-G (GR-1). EGFP(high) cells stained positive for CD2, CD3, CD8, TCR beta-chain, and NK1.1 but did not express the B cell and monocyte markers CD45RA, CD19, and CD11b. In vitro stimulation assays revealed no difference in lymphocyte proliferation and IL-2 secretion between EGFP+ and EGFP- mice. Intravital microscopy of untreated or TNF-alpha-treated cremaster muscle venules showed EGFP+ cells in vivo, but these cells did not roll or adhere to the vessel wall. In cremaster muscle venules treated with both TNF-alpha and IFN-gamma, EGFP(high) cells rolled, adhered, and transmigrated at a rolling velocity slightly higher (11 microm/s) than that of neutrophils (10 microm/s). Blocking alpha4 integrin with a mAb increased rolling velocity to 24 microm/s. These findings show that CD8+ T cells roll in TNF-alpha/IFN-gamma-pretreated vessels in vivo via an alpha4 integrin-dependent pathway.

Vascular endothelial growth factor expression in human endometrium is regulated by hypoxia

Endometrial growth and repair after menstruation are associated with profound angiogenesis. Abnormalities in these processes result in excessive or unpredictable bleeding patterns and are common in many women. It is therefore important to understand which factors regulate normal endometrial angiogenesis. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that plays an important role in normal and pathological angiogenesis. In this study we show that expression of VEGF is regulated by hypoxia in human endometrium. Culture in vitro for 24 h under hypoxic conditions resulted in a 2- to 6-fold increase in VEGF secretion by both stromal and epithelial cells isolated from human endometrium. Quantitative RT-PCR was used to measure VEGF messenger ribonucleic acid (mRNA) levels in these cells. After hypoxia, VEGF mRNA levels increased 1.8-fold in stromal cells and 3.4-fold in glandular epithelial cells. The mRNA for each VEGF splice variant increased to an equal extent. The increase in VEGF secretion by stromal and epithelial cells in response to hypoxia was not altered by treatment at the same time with estradiol or progesterone. In situ hybridization of human endometrium during menstruation, when steroid levels are low but the tissue is subject to ischemia, showed strong hybridization to VEGF mRNA in both stromal and glandular cells. These results show that local factors, such as hypoxia, can regulate VEGF expression in the endometrium. This may play an important part in normal endometrial repair after menstruation. The secretion of VEGF by endometrial cells under hypoxic conditions may also be important in the pathogenesis of endometriosis, because it would be predicted to assist revascularization of desquamated endometrial explants when they attach at ectopic sites.

Aggregation and distribution of strains in microparasites

Recent research has shown that many parasite populations are made up of a number of epidemiologically distinct strains or genotypes. The implications of strain structure or genetic diversity for parasite population dynamics are still uncertain, partly because there is no coherent framework for the interpretation of field data. Here, we present an analysis of four published data sets for vector-borne microparasite infections where strains or genotypes have been distinguished: serotypes of African horse sickness (AHS) in zebra; types of Nannomonas trypanosomes in tsetse flies; parasite-induced erythrocyte surface antigen (PIESA) based isolates of Plasmodium falciparum malaria in humans, and the merozoite surface protein 2 gene (MSP-2) alleles of P. falciparum in humans and in anopheline mosquitoes. For each data set we consider the distribution of strains or types among hosts and any pairwise associations between strains or types. Where host age data are available we also compare age-prevalence relationships and estimates of the force of infection. Multiple infections of hosts are common and for most data sets infections have an aggregated distribution among hosts with a tendency towards positive associations between certain strains or types. These patterns could result from interactions (facilitation) between strains or types, or they could reflect patterns of contact between hosts and vectors. We use a mathematical model to illustrate the impact of host-vector contact patterns, finding that even if contact is random there may still be significant aggregation in parasite distributions. This effect is enhanced if there is non-random contact or other heterogeneities between hosts, vectors or parasites. In practice, different strains or types also have different forces of infection. We anticipate that aggregated distributions and positive associations between microparasite strains or types will be extremely common.

Plasmodium-induced inflammation by uric acid

Infection of erythrocytes with the Plasmodium parasite causes the pathologies associated with malaria, which result in at least one million deaths annually. The rupture of infected erythrocytes triggers an inflammatory response, which is induced by parasite-derived factors that still are not fully characterized. Induced secretion of inflammatory cytokines by these factors is considered a major cause of malaria pathogenesis. In particular, the inflammatory cytokine tumor necrosis factor (TNF) is thought to mediate most of the life-threatening pathologies of the disease. Here we describe the molecular characterization of a novel pathway that results in the secretion of TNF by host cells. We found that erythrocytes infected by Plasmodium accumulate high concentrations of hypoxanthine and xanthine. Degradation of Plasmodium-derived hypoxanthine/xanthine results in the formation of uric acid, which triggers the secretion of TNF. Since uric acid is considered a "danger signal" released by dying cells to alert the immune system, Plasmodium appears to have co-evolved to exploit this warning system. Identifying the mechanisms used by the parasite to induce the host inflammatory response is essential to develop urgently needed therapies against this disease.

Expression of the VEGF and angiopoietin genes in endometrial atypical hyperplasia and endometrial cancer

Angiogenesis is critical for the growth and metastasis of endometrial cancer and is therefore an important therapeutic target. Vascular endothelial growth factor-A (VEGF-A) is a key molecule in angiogenesis, but the identification of related molecules and the angiopoietins suggests a more complex picture. We investigated the presence of transcripts for VEGF-A, VEGF-B, VEGF-C, VEGF-D, Angiopoietin-1 and Angiopoietin-2 in benign endometrium, atypical complex hyperplasia (ACH) and endometrioid endometrial carcinoma using in situ hybridisation. We confirmed the presence of VEGF-A mRNA in the epithelial cells of cancers examined (13 out of 13), but not in benign endometrium or ACH. We also demonstrate, using quantitative polymerase chain reaction, that levels of VEGF-B mRNA are significantly lower in endometrial cancer than benign endometrium. We conclude that loss of VEGF-B may contribute to the development of endometrial carcinoma by modulating availability of receptors for VEGF-A.

An in vitro model of lissencephaly: expanding the role of DCX during neurogenesis

Lissencephaly comprises a spectrum of brain malformations due to impaired neuronal migration in the developing cerebral cortex. Classical lissencephaly is characterized by smooth cerebral surface and cortical thickening that result in seizures, severe neurological impairment and developmental delay. Mutations in the X-chromosomal gene DCX, encoding doublecortin, is the main cause of classical lissencephaly. Much of our knowledge about DCX-associated lissencephaly comes from post-mortem analyses of patient's brains, mainly since animal models with DCX mutations do not mimic the disease. In the absence of relevant animal models and patient brain specimens, we took advantage of induced pluripotent stem cell (iPSC) technology to model the disease. We established human iPSCs from two males with mutated DCX and classical lissencephaly including smooth brain and abnormal cortical morphology. The disease was recapitulated by differentiation of iPSC into neural cells followed by expression profiling and dissection of DCX-associated functions. Here we show that neural stem cells, with absent or reduced DCX protein expression, exhibit impaired migration, delayed differentiation and deficient neurite formation. Hence, the patient-derived iPSCs and neural stem cells provide a system to further unravel the functions of DCX in normal development and disease.

Zebrafish: a genetic model for hemostasis and thrombosis

Here we review the zebrafish hemostatic system, its relevance to mammalian hemostasis, and its efficacy as a vertebrate genetic model to further the understanding of hemostasis and thrombosis.

Detection of Lewy bodies in Trisomy 21 (Down's syndrome)

The presence of cortical senile plaques and neurofibrillary tangles sufficient to warrant a neuropathological diagnosis of Alzheimer's disease is well established in middle-aged individuals with Trisomy 21 (Down's syndrome). In contrast a relationship between Down's syndrome and Lewy bodies, one of the major neuropathological features of Parkinson's disease, has not been previously reported. In a clinico-neuropathological survey of 23 cases of Down's Syndrome, two patients, aged 50 and 56 years respectively, were found to have Lewy body formation in the substantia nigra in addition to cortical Alzheimer-type pathology. Neither case showed significant substantia nigra neuron loss although locus coeruleus loss was present in both. Since substantia nigra Lewy bodies are a characteristic neurohistological feature of idiopathic Parkinson's disease, their occurrence in cases of Down's syndrome with evidence of Alzheimer-type pathology supports an aetiopathological connection between Parkinson's disease, Alzheimer's disease, and Down's syndrome; and suggests that common pathogenic mechanisms may underlie aspects of neuronal degeneration in these three disorders, some of which may relate to aberrant chromosome 21 expression.

Population structuring of multi-copy, antigen-encoding genes in Plasmodium falciparum

The coexistence of multiple independently circulating strains in pathogen populations that undergo sexual recombination is a central question of epidemiology with profound implications for control. An agent-based model is developed that extends earlier ‘strain theory’ by addressing the var gene family of Plasmodium falciparum. The model explicitly considers the extensive diversity of multi-copy genes that undergo antigenic variation via sequential, mutually exclusive expression. It tracks the dynamics of all unique var repertoires in a population of hosts, and shows that even under high levels of sexual recombination, strain competition mediated through cross-immunity structures the parasite population into a subset of coexisting dominant repertoires of var genes whose degree of antigenic overlap depends on transmission intensity. Empirical comparison of patterns of genetic variation at antigenic and neutral sites supports this role for immune selection in structuring parasite diversity.

DOI:http://dx.doi.org/10.7554/eLife.00093.001

Malaria is an infectious disease that is estimated to kill more than half a million people every year, mostly young children in Africa. It is spread by mosquitos that are infected with Plasmodium parasites that attack red blood cells in the human body. Plasmodium falciparum, the species that is responsible for most of these deaths, causes malaria by entering red blood cells and releasing antigens that travel to the surface of the cells, where they change the adhesion properties. This causes the infected red blood cells to accumulate in small blood vessels, surface capillaries or the brain, which can have severe consequences for the person infected.

P. falciparum is particularly dangerous because of its ability to vary the antigens displayed on the cell surface: this process, known as antigenic variation, helps to maintain infections for extended periods of time by allowing the antigens to stay one step ahead of the immune system (a process known as immune escape). The origins of antigenic variation lie in the fact that each P. falciparum genome has a repertoire of between 50 and 60 var genes that code for the variability of a major antigen that is responsible for immune escape in malaria. Molecular sequencing has shown that local parasite populations contain thousands of different types of var genes: hence, meiotic recombination in the mosquito can create a vast number of combinations of var repertoires.

Artzy-Randrup et al. have developed a computational model of this highly diverse and complex system to address the following question: is a local pathogen population composed of largely random and ephemeral repertoires of these genes, or is it structured into independently circulating strains? Their model goes beyond previous models by including interactions within the local host population that arise as a result of indirect competition between different strains of the pathogen for available hosts: this competition is influenced by the history of infection and, therefore, by the patterns of immunity within the host population. Previous models included within-host processes but not these higher, local population-level interactions.

The model simulates the dynamics of all the unique combinations of var genes in a population of hosts, and shows that even with high rates of reproduction, the parasite population self-organizes into a limited number of coexisting strains: the distinct var repertoires of these strains only weakly overlap, suggesting that the immune response of the host population has been partitioned into distinct niches. By investigating genetic variation at both antigenic sites and regions of the genome that do not code for antigens, Artzy-Randrup et al. suggest that immune selection—the selection imposed on var repertoires by the build up of specific immunity at the population level—plays a central role in structuring parasite diversity.

The new model should lead to a better understanding of the epidemiology of Plasmodium and other pathogens that work in similar ways, including Trypanosoma brucei (sleeping sickness), Borellia burgdorferi (Lyme disease) and Giardia lamblia (gastroenteritis), and help with global efforts to eliminate malaria and other diseases.

DOI:http://dx.doi.org/10.7554/eLife.00093.002

Technology Informatics Guiding Education Reform - TIGER

Background: While health informatics recommendations on competencies and education serve as highly desirable corridors for designing curricula and courses, they cannot show how the content should be situated in a specific and local context. Therefore, global and local perspectives need to be reconciled in a common framework.

Objectives: The primary aim of this study is therefore to empirically define and validate a framework of globally accepted core competency areas in health informatics and to enrich this framework with exemplar information derived from local educational settings.

Methods: To this end, (i) a survey was deployed and yielded insights from 43 nursing experts from 21 countries worldwide to measure the relevance of the core competency areas, (ii) a workshop at the International Nursing Informatics Conference (NI2016) held in June 2016 to provide information about the validation and clustering of these areas and (iii) exemplar case studies were compiled to match these findings with the practice. The survey was designed based on a comprehensive compilation of competencies from the international literature in medical and health informatics.

Results: The resulting recommendation framework consists of 24 core competency areas in health informatics defined for five major nursing roles. These areas were clustered in the domains “data, information, knowledge”, “information exchange and information sharing”, “ethical and legal issues”, “systems life cycle management”, “management” and “biostatistics and medical technology”, all of which showed high reliability values. The core competency areas were ranked by relevance and validated by a different group of experts. Exemplar case studies from Brazil, Germany, New Zealand, Taiwan/China, United Kingdom (Scotland) and the United States of America expanded on the competencies described in the core competency areas.

Conclusions: This international recommendation framework for competencies in health informatics directed at nurses provides a grid of knowledge for teachers and learner alike that is instantiated with knowledge about informatics competencies, professional roles, priorities and practical, local experience. It also provides a methodology for developing frameworks for other professions/disciplines. Finally, this framework lays the foundation of cross-country learning in health informatics education for nurses and other health professionals.

Distribution of vascular endothelial growth factor (VEGF) and its binding sites at the maternal-fetal interface during gestation in pigs

Pigs show epitheliochorial placentation, in which the maternal uterine epithelium and the fetal trophectoderm become closely apposed. There is no invasion of trophoblast into the maternal tissue, and nutrient and waste exchange take place across two epithelial layers beneath which a complex network of capillaries forms. Later in gestation, the epithelial cells become indented by blood vessels, which greatly reduces the distance for diffusion between the two circulatory systems. Vascular endothelial growth factor is a secreted homodimeric angiogenic growth factor that is involved in physiological and pathological angiogenesis. Its receptors are generally restricted to endothelial cells. Ligand binding, in situ hybridization and immunohistochemistry were carried out in pig placenta throughout gestation to investigate the possible role of vascular endothelial growth factor and its receptors in non-invasive placentation. In situ hybridization and immunohistochemistry revealed that mRNA and immunoreactivity for vascular endothelial growth factor were localized in both maternal and fetal epithelial cells at the maternal-fetal interface and over the maternal glands, although the signal was generally weaker in the maternal glands. Ligand binding was used to localize for vascular endothelial growth factor receptors; no binding was observed over the maternal glands, but very strong binding was localized to the endometrial blood vessels. At the interface between maternal and fetal tissue, a similar pattern was observed whereby the numerous small capillaries at the bases of the two apposed epithelia bound vascular endothelial growth factor specifically. It is concluded that vascular endothelial growth factor produced by the maternal and fetal epithelial layers promotes the growth of capillaries locally, which would facilitate the development of two vascular networks for the efficient transfer of nutrients and waste products.