bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinants of attitudes towards predators in central Kenya and suggestions for increasing tolerance in livestock dominated landscapes
Authors: Romañach Stephanie S. , Lindsey Peter A. , Woodroffe Rosie
Published: May 2007

Where people and livestock live with predators there is often conflict that can lead to lethal control of predators. We evaluated attitudes of local people towards large predators and developed a novel index of tolerance by quantifying the number of livestock respondents would be willing to lose before killing the predator responsible. We interviewed 416 subsistence livestock farmers (community members) and commercial livestock ranchers in central Kenya. Commercial ranchers had more positive attitudes and higher tolerance than community members. Community members said their tolerance would increase if they were to derive income from ecotourism or trophy hunting. We found that community members with land title deeds were most tolerant of predators, stressing the importance of land security for conservation efforts. Subsistence livestock farming is the primary land use throughout much of Africa and, as a result, identifying strategies to improve tolerance of predators under this land tenure system is of major conservation significance.
Habitat changes reduce the carrying capacity of Hluhluwe-Umfolozi Park, South Africa, for Critically Endangered black rhinoceros Diceros bicornis
Authors: Reid Caroline , Slotow Rob , Howison Owen , Balfour Dave
Published: May 2007

The Critically Endangered black rhinoceros Diceros bicornis occurs mainly in protected areas. Hluhluwe-Umfolozi Park, South Africa, contains a key source population for black rhino conservation, and declining population productivity has been attributed to negative habitat changes and a reduction in carrying capacity. As home range increase may be an index of declining habitat quality we determined the home ranges of the black rhino in the Park and compared these ranges with previous estimates. The average size of the home ranges during 1991–2001 was 23.07 ± SE 0.81 km2, which is 54% greater than in the 1980s. Sex and the availability of water did not influence home ranges. Home ranges decreased in winter. Female:male ratios varied across the Park, indicating that one or both sexes may prefer specific areas. Changes in vegetation structure and composition may have caused rhino to maintain larger ranges in order to meet their nutritional requirements. Ongoing review of stocking rates, population performance (including indicators such as range size), and intervention strategies are necessary to manage black rhino in dynamic savannah ecosystems.
Rates and causes of mortality in Endangered African wild dogs
Lycaon pictus: lessons for management and
monitoring
Authors: Woodroffe Rosie , Davies-Mostert Harriet , Ginsberg Joshua , Graf Jan , Leigh Kellie , McCreery Kim , Robbins Robert , Mills Gus , Pole Alistair , Rasmussen Gregory , Somers Michael , Szykman Micaela
Published: May 2007

Effective species conservation depends upon correctly identifying the threats
that cause decline or hinder recovery. Because estimates of the relative
viability of different populations of Endangered African wild dogs Lycaon pictus are most strongly influenced by adult
and pup mortality, we analysed rates and causes of mortality in eight wild dog
populations under study in southern and eastern Africa. The probabilities of
detecting wild dog deaths were influenced by the monitoring methods used. The
least biased estimates of mortality causes were obtained through intensive
monitoring of radio-collared individuals; this is impossible for pups, however.
Mortality patterns varied substantially between populations. Rates of
human-caused mortality were higher for wild dogs radio-collared outside
protected areas than for those collared inside, but rates of natural mortality
were comparable, suggesting that anthropogenic mortality is additive to natural
mortality. The relative importance of factors such as snaring and infectious
disease also varied regionally. Hence, although our analyses identified no new
threats beyond those highlighted in a 1997 range-wide Action Plan, they suggest
that local plans will be valuable to target conservation activities more
precisely.
The potential of forest reserves for augmenting the protected area network in Africa
Authors: Burgess Neil D. , Loucks Colby , Stolton Sue , Dudley Nigel
Published: May 2007

The protected area network of Africa has grown from nothing to over 2 million km2 in the past 110 years. This network covers parts of all biomes and priority areas for biodiversity conservation but protected area gaps remain, as identified at the 5th World Parks Congress in 2003. Forest reserves, managed by Forest Departments, are typically excluded from global protected area lists, but in Africa they are found in 23 countries and cover at least 549,788 km2, adding 25% to the conservation estate. Forest reserves protect 5.3% (2,027 km2) of the dry forest habitats, 5% (165,285 km2) of lowland and montane moist forests, 2.6% (364,354 km2) of savannah woodlands, 1.8% (10,561 km2) of flooded grasslands, and 1.65% (1,177 km2) of mangroves. Forest reserves also protect parts of three conservation schemes: 6.5% (61,630 km2) of BirdLife's Endemic Bird Areas, 3.4% (147,718 km2) of Conservation International's Hotpots and 3.4% (346,864 km2) of WWF's Global 200 Ecoregions. Several of the global protected area gaps identified in Africa are also covered by forest reserves, in the Eastern Arc Mountains, Eastern African coastal forests, Kenyan Highlands, Cameroon-Nigerian Mountains, West African Forests and mountain areas of Malawi, Zimbabwe, Mozambique and Zambia. Some African forest reserves have a legally defined role in biodiversity conservation and are strictly protected; they thus fit criteria for protected areas. Working with forest departments in individual countries may help develop a more comprehensive protected area network without creating additional new reserves.
Validation of Cerebral Venous Oxygenation Measured Using Near-Infrared Spectroscopy and Partial Jugular Venous Occlusion in the Newborn Lamb
Authors: Wong Flora Y , Barfield Charles P , Campbell Louisa , Brodecky Vojta A , Walker Adrian M
Published: May 2007

Near-infrared spectroscopy combined with partial jugular venous occlusion (JVO) offers promise for determining cerebral venous saturation (CSvO2) in sick preterm infants, but has not been validated in the newborn brain or under conditions of hypoxaemia. We assessed the accuracy of the CSvO2 estimate using cerebral venous oxygen saturation in superior sagittal sinus blood (SSSO2) as the ‘gold standard’. Comparisons were made in seven newborn lambs over a wide range of arterial oxygen saturations (SaO2) of 20% to 100%. Overall, median (range) CSvO2 was 49.8% (10.6% to 88.5%), whereas SSSO2 was 45.5% (4.3% to 76.6%); Bland—Altman analysis revealed a mean difference (CSvO2—SSSO2) of 5.1% and limits of agreement of ±27.4%. The change in cerebral blood volume (Δ CBV) induced by JVO increased with SaO2 ( P <0.05). In addition, the strength of the correlation of CSvO2 with SSSO2 progressively improved with increasing change in total haemoglobin concentration (Δ HbT) induced by JVO. With Bland—Altman analysis repeated for data with Δ HbT >30 μmol cm, the mean difference (CSvO2—SSSO2) decreased to 2.4% with limits of agreement of ±18.8%. We conclude that the accuracy of estimating CSvO2 varies with the Δ CBV induced by JVO. Potential differences of optical properties between the head of the lamb and the human infant suggest that caution be exercised in directly applying these data to the human newborn. Nevertheless, this critical aspect of the JVO technique needs to be taken into consideration in developing an accurate measurement for sick preterm human infants.
Interleukin-6 Stimulates Circulating Blood-Derived Endothelial Progenitor Cell Angiogenesis in vitro
Authors: Fan Yongfeng , Ye Jianqin , Shen Fanxia , Zhu Yiqian , Yeghiazarians Yerem , Zhu Wei , Chen Yongmei , Lawton Michael T , Young William L , Yang Guo-Yuan
Published: May 2007

Circulating blood endothelial progenitor cells (EPCs) contribute to postnatal vasculogenesis, providing a novel therapeutic target for vascular diseases. However, the molecular mechanism of EPC-induced vasculogenesis is unknown. Interleukin-6 plays multiple functions in angiogenesis and vascular remodeling. Our previous study demonstrated that the polymorphism (174G > C) in IL-6 gene promoter was associated with brain vascular disease. In this study, we investigated if IL-6 receptor is expressed in human EPCs derived from circulating mononuclear cells, and if interleukin-6 (IL-6) stimulates EPC angiogenesis in vitro. First, we isolated and cultured mononuclear cells from adult human circulating blood. We obtained EPC clones that were further cultured and expended for the angiogenesis study. We found that the EPCs possessed human mature endothelial cell phenotypes; however, they proliferated much faster than mature endothelial cells ( P <0.05). We then found that IL-6 receptor (gp-80) was expressed in the EPCs, and that administration of IL-6 could activate receptor gp80/gp130 signaling pathways including downstream extracellular signal-regulated kinase 1/2 and STAT3 phosphorylation in EPCs. Furthermore, IL-6 stimulated EPC proliferation, migration, and matrigel tube formation in a dose-dependent manner ( P <0.05); anti-IL-6 antibodies or IL-6 receptor could abolish these effects ( P <0.05). These results suggest that IL-6 plays a crucial role in the biologic behavior of blood-derived EPCs, which may help clarify the mechanism of IL-6 inflammatory-related diseases.
Removal of triacylglycerols from chylomicrons and VLDL by capillary beds: the basis of lipoprotein remnant formation
Authors: Karpe F. , Bickerton A.S. , Hodson L. , Fielding B.A. , Tan G.D. , Frayn K.N.
Published: May 2007

The triacylglycerol content of chylomicrons and VLDL (very-low-density lipoprotein) compete for the same lipolytic pathway in the capillary beds. Although chylomicron triacylglycerols appear to be the favoured substrate for lipoprotein lipase, VLDL particles compete in numbers. Methods to quantify the specific triacylglycerol removal from VLDL and chylomicrons may involve endogenous labelling of the triacylglycerol substrate with stable isotopes in combination with arteriovenous blood sampling in humans. Arteriovenous quantification of remnant lipoproteins suggests that adipose tissue with its high lipoprotein lipase activity is a principal site for generation of remnant lipoproteins. Under circumstances of reduced efficiency in the removal of triacylglycerols from lipoproteins, there is accumulation of remnant lipoproteins, which are potentially atherogenic.
Using membrane stress to our advantage
Authors: Shearman G.C. , Attard G.S. , Hunt A.N. , Jackowski S. , Baciu M. , Sebai S.C. , Mulet X. , Clarke J.A. , Law R.V. , Plisson C. , Parker C.A. , Gee A. , Ces O. , Templer R.H.
Published: May 2007

The nature of the bilayer motif coupled with the ability of lipids and proteins to diffuse freely through this structure is crucial to the viability of cells and their ability to compartmentalize domains contained therein. It seems surprising to find then that biological as well as model membranes exist in a dynamic state of mechanical stress. The stresses within such membranes are surprisingly large, typically reaching up to 50 atm (1 atm=101.325 kPa) at the core of the membrane and vary as a function of depth. The uneven distribution of lateral pressures within monolayer leaflets causes them to bend away from or towards the water interface. This can result in the formation of complex, self-assembled mesophases, many of which occur in vivo. Our knowledge of the principles underlying membrane mechanics has reached the point where we are now able to manipulate them and create nano-structures with reasonable predictability. In addition, they can be used both to explain and control the partitioning of amphipathic proteins on to membranes. The dependence of the dynamics of membrane-bound proteins and the chemical reactivity of amphipathic drug molecules on membrane stresses suggests that Nature itself takes advantage of this. Understanding and manipulating these internal forces will be a key element in creating self-assembled, biocompatible, nanoscale cell-like systems.
Design and chance in the self-assembly of macromolecules
Authors: Worrall J.A.R. , Górna M. , Pei X.Y. , Spring D.R. , Nicholson R.L. , Luisi B.F.
Published: May 2007

The principles of self-assembly are described for naturally occurring macromolecules and for complex assemblies formed from simple synthetic constituents. Many biological molecules owe their function and specificity to their three-dimensional folds, and, in many cases, these folds are specified entirely by the sequence of the constituent amino acids or nucleic acids, and without the requirement for additional machinery to guide the formation of the structure. Thus sequence may often be sufficient to guide the assembly process, starting from denatured components having little or no folds, to the completion state with the stable, equilibrium fold that encompasses functional activity. Self-assembly of homopolymeric structures does not necessarily preserve symmetry, and some polymeric assemblies are organized so that their chemically identical subunits pack stably in geometrically non-equivalent ways. Self-assembly can also involve scaffolds that lack structure, as seen in the multi-enzyme assembly, the degradosome. The stable self-assembly of lipids into dynamic membraneous sheets is also described, and an example is shown in which a synthetic detergent can assemble into membrane layers.
Health effects of nanomaterials
Authors: Tetley T.D.
Published: May 2007

With the rapid growth of nanotechnology and future bulk manufacture of nanomaterials comes the need to determine, understand and counteract any adverse health effects of these materials that may occur during manufacture, during use, or accidentally. Nanotechnology is expanding rapidly and will affect many aspects of everyday life; there are already hundreds of products that utilize nanoparticles. Paradoxically, the unique properties that are being exploited (e.g. high surface reactivity and ability to cross cell membranes) might have negative health impacts. The rapid progress in development and use of nanomaterials is not yet matched by toxicological investigations. Epidemiological studies implicate the ultrafine (nano-sized) fraction of particulate air pollution in the exacerbation of cardiorespiratory disease and increased morbidity. Experimental animal studies suggest that the increased concentration of nanoparticles and higher reactive surface area per unit mass, alongside unique chemistry and functionality, is important in the acute inflammatory and chronic response. Some animal models have shown that nanoparticles which are deposited in one organ (e.g. lung and gut) may access the vasculature and target other organs (e.g. brain and liver). The exact relationship between the physicochemistry of a nanoparticle, its cellular reactivity, and its biological and systemic consequences cannot be predicted. It is important to understand such relationships to enjoy the benefits of nanotechnology without being exposed to the hazards.
Synthetic de novo designed polypeptides for control of nanoparticle assembly and biosensing
Authors: Aili D. , Enander K. , Baltzer L. , Liedberg B.
Published: May 2007

This contribution describes how de novo designed synthetic helix–loop–helix polypeptides are utilized to control the assembly of gold nanoparticles and as scaffolds for biosensing. The synthetic polypeptides are designed to fold into a four-helix bundle upon dimerization. When immobilized on gold nanoparticles, dimerization and folding occur between peptides on neighbouring particles as an effect of particle aggregation and the folded polypeptides are rigid enough to keep the particles separated at a distance corresponding to the size of the four-helix bundle. Moreover, peptide dimerization offers a convenient route to assemble nanoparticles into hybrid multilayers on planar substrates. The drastic change in the resonance conditions of the localized nanoparticle surface plasmon upon particle aggregation is shown to be useful for optical detection of biomolecular interactions.
The proteins BACE1 and BACE2 and β-secretase activity in normal and Alzheimer's disease brain
Authors: Stockley J.H. , O'Neill C.
Published: May 2007

The insidious progression of AD (Alzheimer's disease) is believed to be linked closely to the production, accumulation and aggregation of the ∼4.5 kDa protein fragment called Aβ (amyloid β-peptide). Aβ is produced by sequential cleavage of the amyloid precursor protein by two enzymes referred to as β- and γ-secretase. β-Secretase is of central importance, as it catalyses the rate-limiting step in the production of Aβ and was identified 7 years ago as BACE1 (β-site APP-cleaving enzyme 1). Soon afterwards, its homologue BACE2 was discovered, and both proteins represent a new subclass of the aspartyl protease family. Studies examining the regulation and function of β-secretase in the normal and AD brain are central to the understanding of excessive production of Aβ in AD, and in targeting and normalizing this β-secretase process if it has gone awry in the disease. Several reports indicate this, showing increased β-secretase activity in AD, with recent findings by our group showing changes in β-secretase enzyme kinetics in AD brain caused by an increased Vmax. This article gives a brief review of studies which have examined BACE1 protein levels and β-secretase activity in control and AD brain, considering further the expression of BACE2 in the human brain.
Exploiting new genome data and Internet resources for the phylogenetic analysis of proteases, substrates and inhibitors
Authors: Southan C.
Published: May 2007

Multiple alignments and phylogenetic tree constructions are established techniques for examining the evolutionary history of protease sequences in organisms such as humans, mice, fruitflies, nematode worms and yeast. They also facilitate the mapping of those conserved positions that are important for structure and catalytic function. However, the continued increase in completed or draft genomes offers new opportunities for examining protease evolution across a broader (e.g. more mammals) and deeper (e.g. more invertebrates) phylogenetic range. In addition, the improving annotation not only of proteases, but also of their substrates, interaction partners in proteolytic complexes and endogenous inhibitor proteins now means that aspects of co-evolution can be addressed. The increasing phylogenetic coverage is also important for resolving orthology issues that arise from protease gene duplication or loss in different lineages. Selected sequences will be used to exemplify the utility of Internet resources and present results for these types of analysis.
Genome plasticity in the mouse oocyte and early embryo
Authors: Peaston A.E. , Knowles B.B. , Hutchison K.W.
Published: May 2007

In dissecting the molecules and molecular mechanisms that control mammalian oocyte-to-embryo transition, we found abundant transcripts representing developmentally regulated ERVs (endogenous retroviruses) in mouse oocyte and two-cell stage embryo cDNA libraries. These retrotransposons can act as alternative promoters and first exons for diverse genes, synchronizing their expression. Heritable genetic change due to replication of these retrotransposons probably occurs specifically in oocytes and early embryos. ERVs are usually epigenetically silenced, through DNA methylation and chromatin-based mechanisms. Their activation and silencing indicates a change in the epigenetic state of the genome. The thousands of endogenous retro-elements in the mouse genome provides potential scope for large-scale co-ordinated epigenetic fluctuations and leads to the hypothesis that differential transposable element expression triggers sequential reprogramming of the embryonic genome during the oocyte-to-embryo transition.
Endogenous retrovirus expression in testis and epididymis
Authors: Crowell R.C. , Kiessling A.A.
Published: May 2007

ERVs (endogenous retroviruses), which comprise 8–10% of mouse and human genomes, are present in thousands of copies, ranging in size from complete 9 kb virus to truncated partial sequences. Despite well-documented differential expression of ERVs in normal and diseased tissues, their biological significance remains controversial. Work in this laboratory revealed remarkably high ERV expression in mouse epididymis, but not in testis. Similar early studies revealed expression of human ERV-E4.1 in both testis and epididymis, but expression of other HERVs (human ERVs) was not examined. Using degenerate primers to conserved regions of reverse transcriptase specific for each of nine HERV families, we have detected expression of six HERV families in epididymis and three in testis. Differential HERV expression may reflect the fully differentiated state of epididymal epithelium in contrast with the immature germ cell population in the testis. These two tissues may therefore lay the groundwork not only for understanding the influence of cellular differentiation on HERV expression, but also to reveal HERVs that are routinely exposed to sperm.
Macrolide use and the risk of vascular disease in HIV-infected men in the Multicenter AIDS Cohort Study
Authors: Woolley Ian J. , Li Xiuhong , Jacobson Lisa P. , Palella Frank J. , Ostergaard Lars
Published: May 2007

Background: There has been increasing concern that HIV-infected individuals may be more at risk for cardiovascular events in the highly-active antiretroviral therapy (HAART) era. This study examined the risk of thromboembolic events in HIV-infected and non-infected individuals and the effect of macrolide prophylaxis on those outcomes. Methods: A subcohort analysis was undertaken using data collected in the Multicenter AIDS Cohort Study to examine the relative risk of vascular events (myocardial infarction, unstable angina and ischaemic stroke). Cox proportional hazard model using age as the time scale with time varying cofactors obtained at each semi-annual visit were used to assess the independent effect of macrolide use. Results: Controlling for other significant effects including race and smoking, HIV-infection was not independently associated with vascular events. Increased risk was observed among those who used HAART (relative hazard 1.09, 95% confidence intervals 1.00–1.19 in multivariate model), antihypertensive treatment (1.81 [1.26–2.60]), lipid-lowering medication (1.65 [1.12–2.42]), and antibiotics (1.72 [1.25–2.36]). The protective association of macrolide use for a vascular event in the HAART era was also significant (0.10 [0.01–0.75]). Conclusions: Traditional risk factors are important in the pathogenesis of vascular events in HIV-infected individuals. Macrolide antibiotics may have a protective effect in the HIV-infected individuals in the HAART era.
Using hepatitis A and B vaccination as a paradigm for effective HIV vaccine delivery
Authors: Rhodes Scott D. , Yee Leland J.
Published: May 2007

Background: An understanding of vaccine acceptance and uptake is imperative for successful vaccination of populations that will be primary targets for vaccination after a vaccine against HIV is developed and ready for dissemination. Experiences with vaccination against vaccine-preventable hepatitis (VPH) among men who have sex with men (MSM) may offer key insights to inform future HIV vaccination strategies. The purpose of this analysis was to explore what is known currently about vaccination among MSM, using knowledge gained from vaccination against VPH, and to identify important considerations from these experiences that must be explored further as a vaccine against HIV is promoted among MSM. Because cultural and political differences make it difficult to extrapolate findings from studies in one country to another, we have focused our analyses on studies conducted in the USA. Methods: Through a qualitative systematic review of published reports, we identified eight studies that reported correlates of VPH among MSM in the USA. Results: Six major domains of variables associated with vaccination against VPH were identified, including: demographics (e.g. younger age, higher educational attainment); increased vaccine knowledge; increased access to health care; provider recommendation; behaviours (e.g. same-sex behaviour, health-promoting and disease-preventing behaviours); and psychosocial factors (e.g. openness about one’s sexual orientation, reduced barriers to being vaccinated, self-efficacy). Conclusions: Further research is needed to understand vaccination behaviour among MSM and to maximise acceptance and uptake after a vaccine exists. Experiences with VPH provide a real-world model on which to base preliminary assumptions about acceptance and uptake of a vaccine against HIV.
An extra pair of eyes: do patients want a chaperone when having an anogenital examination?
Authors: Baber James A. , Davies Stephen C. , Dayan Linda S.
Published: May 2007

Background: Anogenital examinations can be embarrassing for patients and can leave clinicians open to accusations of professional misconduct. Little is known about the attitudes of patients in Australia towards the use of chaperones. Methods: In 2006, we surveyed 480 patients attending two sexual health clinics in northern Sydney. Our aim was to determine their attitudes towards the use of chaperones for anogenital examinations. Results: Of the 480, 58% were male and 42% female. Most women (64%) preferred a female examining clinician, whereas most men (68%) had no preference for gender of the examining clinician (P < 0.0001). While 32% of women wanted a chaperone if being examined by a male, 29% did not. Only 4% of women wanted a chaperone when being examined by a female. Only 1% of men wanted a chaperone irrespective of the sex of the examining clinician. Independent predictors of women wanting a chaperone with a male clinician were preference for a female clinician (OR 6.59, 2.48–17.5; P < 0.001) and preference for a female chaperone (OR 4.02, 1.44–11.2; P = 0.008). The majority of participants felt that they should be involved in the decision to have a chaperone. Conclusions: Although a substantial minority of women want a chaperone when being examined by a male, a similar proportion do not want a chaperone. If a woman requests a female clinician, she should be offered a chaperone if there is only a male examiner available. Further study is required to determine why some women want a chaperone and how to distinguish them from other women.
Pilot of non-invasive (oral fluid) testing for HIV within a clinical setting
Authors: Debattista Joseph , Bryson Gregory , Roudenko Nicole , Dwyer John , Kelly Mark , Hogan Patrick , Patten John
Published: May 2007

Background: The objectives of the present study were: to determine the sensitivity and specificity of oral fluid testing compared with the performance of standard blood-based HIV enzyme immunoassay; to assess the feasibility of oral fluid specimen collection from clients for the purposes of HIV testing within a clinical setting; and to assess the clinical and laboratory impact regarding staffing, material resources, expertise and funding of oral fluid testing. Methods: A parallel comparative trial of oral fluid and blood testing was conducted among a group of HIV positive clients and a group of unknown HIV serostatus clients where each client was offered both tests. An ambulatory HIV clinic recruited 175 known HIV positive clients and 179 persons were recruited through an inner city sexual health clinic while attending for routine sexual health checks. Client responses to oral fluid collection were assessed. The sensitivity and specificity of oral fluid testing were calculated. Results: Of the 176 confirmed HIV reactive blood test results, the OraSure (OraSure Technologies, Beaverton, OR, USA) assay failed to detect only one of these, demonstrating a sensitivity of 99.4%. Of the 178 blood specimens that were tested as non-reactive by the AxSYM (Abbott Laboratories, Abbott Park, IL, USA) Combo system, OraSure recorded four of the corresponding oral fluid specimens as reactive (assumed to be false-positive), giving a specificity of 97.6%. Although evaluation of patients undergoing the test showed a large proportion (88.6%) preferred the OraSure test to conventional blood testing, a large minority of these (22.6%) made such a preference conditional on the OraSure test being as reliable as current blood testing. Conclusions: This limited clinic based trial of oral fluid testing for HIV antibodies among an outpatient population has demonstrated the potential of oral fluid as a specimen for HIV testing. However, the lower performance of the test compared with current serum-based tests may limit the usefulness of OraSure to epidemiological studies or as an alternative screening tool in outreach settings among higher risk populations.
Chaperones: protecting the patient or protecting the doctor?
Authors: Rogstad Karen E.
Published: May 2007

The routine use of chaperones during medical examinations, including intimate examinations, is variable. Practice varies between countries and also within them. Use of a chaperone may protect patients from sexual abuse by medical or nursing practitioners. An appropriate chaperone may also protect healthcare practitioners from false accusations. This article considers issues surrounding the use of chaperones and suggests a chaperoning policy for sexual health clinics, while acknowledging that it may not be appropriate or acceptable to all patients or medical staff, or for different parts of the world.
Australian sexual health practitioners' use of chaperones for genital examinations: a survey of attitudes and practice
Authors: Newton Danielle C. , Fairley Christopher K. , Teague Richard , Donovan Basil , Bowden Francis J. , Bilardi Jade , Pitts Marian , Chen Marcus Y.
Published: May 2007

Objectives: To examine the current practice and attitudes of Australian sexual health practitioners towards the use of chaperones for genital examinations. Methods: In July 2006, an anonymous, self-completed questionnaire was mailed to members of the Australasian Chapter of Sexual Health Medicine. Results: Of the 166 questionnaires sent to practitioners, 110 (66%) were returned completed. Of the 110 respondents, only 9% and 19% reported that their clinic routinely provided chaperones for all male and female genital examinations, respectively. Among practitioners whose services did not offer chaperones routinely, chaperones were offered with a mean frequency of 19% for female examinations and 8% for male examinations (P = 0.01). Compared to female practitioners, significantly more male practitioners thought a chaperone was important for medico-legal purposes when examining females (72% v. 53%, P < 0.05). Compared to male practitioners, significantly more female practitioners thought a chaperone was sometimes important for patient support when examining male patients (52% v. 26%, P < 0.001). Only 39% (n = 18) of male practitioners and 36% (n = 23) of female practitioners felt that resources spent on chaperones were justified by the benefits they provided. Conclusions: Despite only a minority of practitioners offering chaperones to patients or using them during examinations, many feel they are important for medico-legal reasons and as support for the patient. Best practice may be for services to routinely offer a chaperone and record instances where an offer is declined. This provides patients with choice and practitioners with some level of protection.
Quantifying HIV-1 transmission due to contaminated injections
Authors: White Richard G. , Ben S. Cooper , Kedhar Anusha , Orroth Kate K. , Biraro Sam , Baggaley Rebecca F. , Whitworth Jimmy , Korenromp Eline L. , Ghani Azra , Boily Marie-Claude , Hayes Richard J.
Published: May 2007

Assessments of the importance of different routes of HIV-1 (HIV) transmission are vital for prioritization of control efforts. Lack of consistent direct data and large uncertainty in the risk of HIV transmission from HIV-contaminated injections has made quantifying the proportion of transmission caused by contaminated injections in sub-Saharan Africa difficult and unavoidably subjective. Depending on the risk assumed, estimates have ranged from 2.5% to 30% or more. We present a method based on an age-structured transmission model that allows the relative contribution of HIV-contaminated injections, and other routes of HIV transmission, to be robustly estimated, both fully quantifying and substantially reducing the associated uncertainty. To do this, we adopt a Bayesian perspective, and show how prior beliefs regarding the safety of injections and the proportion of HIV incidence due to contaminated injections should, in many cases, be substantially modified in light of age-stratified incidence and injection data, resulting in improved (posterior) estimates. Applying the method to data from rural southwest Uganda, we show that the highest estimates of the proportion of incidence due to injections are reduced from 15.5% (95% credible interval) (0.7%, 44.9%) to 5.2% (0.5%, 17.0%) if random mixing is assumed, and from 14.6% (0.7%, 42.5%) to 11.8% (1.2%, 32.5%) under assortative mixing. Lower, and more widely accepted, estimates remain largely unchanged, between 1% and 3% (0.1–6.3%). Although important uncertainty remains, our analysis shows that in rural Uganda, contaminated injections are unlikely to account for a large proportion of HIV incidence. This result is likely to be generalizable to many other populations in sub-Saharan Africa.
Polyelectrostatic interactions of disordered ligands suggest a physical basis for ultrasensitivity
Authors: Borg Mikael , Mittag Tanja , Pawson Tony , Tyers Mike , Forman-Kay Julie D. , Chan Hue Sun
Published: May 2007

Regulation of biological processes often involves phosphorylation of intrinsically disordered protein regions, thereby modulating protein interactions. Initiation of DNA replication in yeast requires elimination of the cyclin-dependent kinase inhibitor Sic1 via the SCF
Cdc4
ubiquitin ligase. Intriguingly, the substrate adapter subunit Cdc4 binds to Sic1 only after phosphorylation of a minimum of any six of the nine cyclin-dependent kinase sites on Sic1. To investigate the physical basis of this ultrasensitive interaction, we consider a mean-field statistical mechanical model for the electrostatic interactions between a single receptor site and a conformationally disordered polyvalent ligand. The formulation treats phosphorylation sites as negative contributions to the total charge of the ligand and addresses its interplay with the strength of the favorable ligand–receptor contact. Our model predicts a threshold number of phosphorylation sites for receptor–ligand binding, suggesting that ultrasensitivity in the Sic1–Cdc4 system may be driven at least in part by cumulative electrostatic interactions. This hypothesis is supported by experimental affinities of Cdc4 for Sic1 fragments with different total charges. Thus, polyelectrostatic interactions may provide a simple yet powerful framework for understanding the modulation of protein interactions by multiple phosphorylation sites in disordered protein regions.
Biphasic role for Wnt/β-catenin signaling in cardiac specification in zebrafish and embryonic stem cells
Authors: Ueno Shuichi , Weidinger Gilbert , Osugi Tomoaki , Kohn Aimee D. , Golob Jonathan L. , Pabon Lil , Reinecke Hans , Moon Randall T. , Murry Charles E.
Published: May 2007

Understanding pathways controlling cardiac development may offer insights that are useful for stem cell-based cardiac repair. Developmental studies indicate that the Wnt/β-catenin pathway negatively regulates cardiac differentiation, whereas studies with pluripotent embryonal carcinoma cells suggest that this pathway promotes cardiogenesis. This apparent contradiction led us to hypothesize that Wnt/β-catenin signaling acts biphasically, either promoting or inhibiting cardiogenesis depending on timing. We used inducible promoters to activate or repress Wnt/β-catenin signaling in zebrafish embryos at different times of development. We found that Wnt/β-catenin signaling before gastrulation promotes cardiac differentiation, whereas signaling during gastrulation inhibits heart formation. Early treatment of differentiating mouse embryonic stem (ES) cells with Wnt-3A stimulates mesoderm induction, activates a feedback loop that subsequently represses the Wnt pathway, and increases cardiac differentiation. Conversely, late activation of β-catenin signaling reduces cardiac differentiation in ES cells. Finally, constitutive overexpression of the β-catenin-independent ligand Wnt-11 increases cardiogenesis in differentiating mouse ES cells. Thus, Wnt/β-catenin signaling promotes cardiac differentiation at early developmental stages and inhibits it later. Control of this pathway may promote derivation of cardiomyocytes for basic research and cell therapy applications.
Mother–offspring competition promotes colonization success
Authors: Cote J. , Clobert J. , Fitze P. S.
Published: May 2007

Colonization is the crucial process underlying range expansions, biological invasions, and metapopulation dynamics. Which individuals leave their natal population to colonize empty habitats is a crucial question and is presently unresolved. Dispersal is the first step in colonization. However, not all dispersing individuals are necessarily good colonizers. Indeed, in some species, the phenotype of dispersers differs depending on the selective pressures that induce dispersal. In particular, kin-based interactions, a factor driving social evolution, should induce different social response profiles in nondispersing and dispersing individuals. Kin competition (defined here as between the mother and offspring) has been proven to produce dispersers with a particular phenotype that may enhance their colonizing ability. By using the common lizard (Lacerta vivipara), we conducted a multipopulation experiment to study the effect of kin competition on dispersal and colonization success. We manipulated mother–offspring interactions, which are the most important component of kin competition in the studied species, at the family and population levels and measured the consequences on colonization success. We demonstrate that mother–offspring competition at the population level significantly influences colonization success. Increased competition at the population level enhanced the colonization rate of the largest juveniles as well as the growth and survival of the colonizers. Based on these results, we calculated that kin-induced colonization halves the extinction probability of a newly initiated population. Because interactions between relatives are likely to affect the ability of a species to track habitat modifications, kin-based dispersal should be considered in the study of invasion dynamics and metapopulation functioning.
Obstetric and perinatal complications in HIV‐infected women. Analysis of a cohort of 167 pregnancies between 1997 and 2003
Authors: MARTÍ COVADONGA , PEÑA JOSE M. , BATES ISABEL , MADERO ROSARIO , DE JOSÉ ISABEL , PALLARDO LUIS FELIPE , RAMÓN ARRIBAS JOSE , GONZALEZ‐GARCIA JUAN , GONZALEZ ANTONIO , JOSÉ VAZQUEZ JUAN
Published: May 2007

Background. The unquestionable benefit of antiretroviral therapy in reducing the rate of mother‐to‐child transmission can be lessened by potential maternal or neonatal toxicity. Objective. To analyze obstetric and perinatal complications in a cohort of HIV‐infected pregnant women and their relationship with maternal antiretroviral therapy. Population. One hundred and sixty‐seven HIV‐infected pregnant women who delivered at Hospital Universitario La Paz, Madrid, Spain between January 1997 and December 2003. Methods. Data on the clinical and epidemiological characteristics of HIV‐infected patients, previous and current antiretroviral therapy, gestational diabetes mellitus, length of pregnancy, mode of delivery, and weight of the newborn were collected. Pregnancy outcomes were compared with those of all the pregnant women attended at our hospital. Main outcome measures. Gestational diabetes mellitus, premature delivery, and low birth weight. Results. Gestational diabetes mellitus was diagnosed in 8.9% of patients. All the cases of gestational diabetes were in the combined antiretroviral therapy group, and the majority were receiving triple antiretroviral therapy with a protease inhibitor. The risk of developing this pathology was greater among women receiving antiretroviral therapy prior to pregnancy. The premature delivery rate was 29% and the low birth weight rate was 28%. Conclusion. Gestational diabetes mellitus is more common in HIV‐infected women than in the general population and is related to combined antiretroviral therapy, especially the use of protease inhibitors, which suggests the need for close follow‐up during pregnancy in HIV‐infected patients. Nevertheless, the adverse perinatal consequences observed were more related to maternal factors than to antiretroviral therapy.
Effect of maternal herpes simplex virus (HSV) serostatus and HSV type on risk of neonatal herpes
Authors: BROWN ELIZABETH L. , GARDELLA CAROLYN , MALM GUNILLA , PROBER CHARLES G. , FORSGREN MARIANNE , KRANTZ ELIZABETH M. , ARVIN ANN M. , YASUKAWA LINDA L. , MOHAN KATHLEEN , BROWN ZANE , COREY LAWRENCE , WALD ANNA
Published: May 2007

Background. Neonatal herpes simplex virus (HSV) is a rare but devastating disease. We have conducted pooled analyses of data from 3 cohorts to evaluate the effects of maternal HSV serostatus and HSV type on risk of neonatal HSV acquisition and severity. Methods. Data from cohorts in Seattle, WA, and Stanford, CA, USA, and Stockholm, Sweden were pooled using Mantel–Haenszel methods. Results. Seventy‐eight infants with documented neonatal HSV and known maternal HSV serostatus were included. The risk of neonatal HSV‐2 infection was similar in infants born to HSV seronegative women compared with HSV‐1 seropositive women (pooled OR: 1.6; 95% CI: 0.6–4.0). The odds of neonatal HSV infection was increased in the presence of exposure to maternal HSV‐1 versus HSV‐2 (adjusted pooled OR: 19.2; 95% CI: 5.8–63.6). An elevated odds of disseminated HSV in infants born to women with newly acquired genital herpes was observed in Stockholm (OR = 13.5; 95% CI: 1.4–630), but not in Seattle or Stanford. Conclusion. Our results suggest that maternal HSV‐1 antibody offers little, if any, protection against neonatal HSV‐2 infection. During reactivation, HSV‐1 appears more readily transmissible to the neonate than HSV‐2, a concerning finding given the rising frequency of genital HSV‐1 infection.
Risk factors for unsuccessful medical abortion with mifepristone and misoprostol
Authors: HAIMOV‐KOCHMAN RONIT , ARBEL REVITAL , SCIAKY‐TAMIR YAEL , BRZEZINSKI AMNON , LAUFER NERI , YAGEL SIMCHA
Published: May 2007

Background. The aim of this study was to determine the effectiveness of medical abortions with mifepristone and misoprostol following the approval of medical abortion in Israel. Methods. A retrospective review of 377 consecutive medical records at an ambulatory care unit of a university medical centre was performed, screening all women undergoing medical abortion with mifepristone and misoprostol. Transvaginal ultrasonographic study and serum βhCG measurement were performed 14–20 days after the procedure. The clinical outcome was defined as complete expulsion of intrauterine contents with (failed group) or without (successful group) surgical intervention. Results. Surgical intervention was performed in 7.4% of patients. Residual products of conception were confirmed in 89%. Older age, previous spontaneous abortions, multigravidity, and earlier follow‐up visit were independently associated with unsuccessful medical abortion. Significant differences were found in mean serum βhCG and mean endometrial thickness in the successful versus failed procedure groups. Conclusions. Medical termination of pregnancy with mifepristone and misoprostol is >90% effective. High risk group for failure of the procedure can be characterised. An algorithm of follow up using follow‐up visit date, serum βhCG and sonographic endometrial stripe is suggested to define high risk patients for failed medical abortion.
Training or EPT in perimenopause on balance and flushes
Authors: BERGSTRÖM INGRID , LANDGREN BRITT‐MARIE , PYYKKÖ ILLMARI
Published: May 2007

With advancing age, the postural balance function deteriorates as a consequence of decreased functional capacity. Deteriorating balance is a risk factor for bone fractures due to increased risks of falls. It has been suggested that the loss of estrogen, which occurs in relation to the menopause, may be associated with loss of balance. Regular physical exercise without balance training has, in some studies, been shown to have positive effects on the postural balance. The aim of the present study was to examine balance function during the perimenopausal period, and evaluate the effect of estrogen plus progesterone therapy (EPT) or aerobic training on balance. Sixty perimenopausal women were recruited to the study. The subjects were then randomised to either physical training (n = 20), EPT (n = 20), or to a control group (n = 20). The study period was 18 months. Postural stability was measured every third month using a custom‐made force platform. The women using EPT achieved better results in 3 of 6 parameters, after 18 months.
Cost‐minimisation analysis of vaginal wall repair in an inpatient or outpatient regimen
Authors: SØRENSEN JAN , AXELSEN SUSANNE MAIGAARD
Published: May 2007

Background. The study's objective was to compare the cost of vaginal wall repair under local anesthesia, undertaken in either an inpatient or an outpatient regimen. The perspective used was that of a department of gynecology over the short and medium term.Methods.The analysis was based on 2 consecutive cohorts of inpatients and outpatients treated in a Danish university hospital. Data on resource use were collected from clinical records and via a patient telephone survey. Salary and drug costs were estimated from national sources. Costs for consumables, complications and overnight stays were estimated from local data. The analysis compared the costs of inpatient and outpatient surgery relating to staff time, anesthesia, operation, recovery, overnight stays and complications. Multiple regression was employed to adjust for confounding variables.Results.The average cost was estimated to be 10,400 DKK per inpatient and 6,100 DKK per outpatient (2004 price level: 1€ = 7.50 DKK). Costs relating to overnight stays and staff costs during operation were the largest contributors to the cost difference. Total cost was significantly associated with type of regimen (in‐ or outpatient), type of operation and complications. After adjustment for confounding variables, the cost difference was estimated at 3,700 DKK (95% bootstrap confidence interval: 2,500–5,000 DKK). The risk of complication was similar for the 2 regimens.Conclusion.Vaginal wall repair under local anesthesia, undertaken in an outpatient regimen, appears to be less costly than in an inpatient regimen.