bluuebunny/crossref_metadata_2025 huggingface dataset:
A fusion protein containing a lepidopteran-specific toxin from the South Indian red scorpion (Mesobuthus tamulus) and snowdrop lectin shows oral toxicity to target insects
Authors: Trung Nghia Pham , Fitches Elaine , Gatehouse John A
Published: April 2006

Background

Despite evidence suggesting a role in plant defence, the use of plant lectins in crop protection has been hindered by their low and species-specific insecticidal activity. Snowdrop lectin (Galanthus nivalis agglutinin; GNA) is transported to the haemolymph of insects after oral ingestion, and can be used as a basis for novel insecticides. Recombinant proteins containing GNA expressed as a fusion with a peptide or protein, normally only toxic when injected into the insect haemolymph, have the potential to show oral toxicity as a result of GNA-mediated uptake.

Results

A gene encoding a toxin, ButaIT, from the red scorpion (Mesobuthus tamulus) was synthesised and assembled into expression constructs. One construct contained ButaIT alone, whereas the other contained ButaIT fused N-terminally to a GNA polypeptide (ButaIT/GNA). Both recombinant proteins were produced using the yeast Pichia pastoris as an expression host, and purified. Recombinant ButaIT and ButaIT/GNA were acutely toxic when injected into larvae of tomato moth (Lacanobia oleracea), causing slow paralysis, leading to mortality or decreased growth. ButaIT/GNA was chronically toxic when fed to L. oleracea larvae, causing decreased survival and weight gain under conditions where GNA alone was effectively non-toxic. Intact ButaIT/GNA was detected in larval haemolymph from insects fed the fusion protein orally, demonstrating transport of the linked polypeptide across the gut. Proteolysis of the fusion protein was also observed. ButaIT/GNA was significantly more toxic that GNA alone when fed to the homopteran Nilaparvata lugens (rice brown planthopper) in liquid artificial diet.

Conclusion

The ButaIT/GNA recombinant fusion protein is toxic to lepidopteran larvae both when injected and when fed orally, showing the utility of GNA as a carrier to transport potentially toxic peptides and proteins across the insect gut. Although ButaIT has been claimed to be lepidopteran-specific, the fusion protein has more wide-ranging insecticidal activity. Fusion proteins based on plant lectins have potential applications in crop protection, both as exogenously applied treatments and as endogenous products in transgenic plants.
Multi-substrate chromosome preparations for high throughput comparative FISH
Authors: Hasterok Robert , Dulawa Joanna , Jenkins Glyn , Leggett Mike , Langdon Tim
Published: April 2006

Background

A modification of a standard method of fluorescence in situ hybridisation (FISH) is described, by which a combination of several substrates and probes on single microscope slides enables more accurate comparisons of the distribution and abundance of chromosomal sequences and improves the relatively low throughput of standard FISH methods.

Results

The utility and application of multi-colour, multi-substrate FISH is illustrated by the simultaneous physical mapping of retrotransposon sequences to three species of Avena, and single locus BAC (bacterial artificial chromosome) clones and rDNA probes to three species of Brachypodium, demonstrating how this would enable better understanding of complex phylogenetic relationships among some of the species belonging to these two genera.

Conclusion

The results show that use of multi-substrate chromosome preparations significantly increases the utility of FISH in comparative analyses of the distribution and abundance of chromosomal sequences in closely related plant species.
Antagonistic interactions between honey bee bacterial symbionts and implications for disease
Authors: Evans Jay D , Armstrong Tamieka-Nicole
Published: April 2006

Background

Honey bees, Apis mellifera, face many parasites and pathogens and consequently rely on a diverse set of individual and group-level defenses to prevent disease. One route by which honey bees and other insects might combat disease is through the shielding effects of their microbial symbionts. Bees carry a diverse assemblage of bacteria, very few of which appear to be pathogenic. Here we explore the inhibitory effects of these resident bacteria against the primary bacterial pathogen of honey bees, Paenibacillus larvae.

Results

Here we isolate, culture, and describe by 16S rRNA and protein-coding gene sequences 61 bacterial isolates from honey bee larvae, reflecting a total of 43 distinct bacterial taxa. We culture these bacteria alongside the primary larval pathogen of honey bees, Paenibacillus larvae, and show that many of these isolates severely inhibit the growth of this pathogen. Accordingly, symbiotic bacteria including those described here are plausible natural antagonists toward this widespread pathogen.

Conclusion

The results suggest a tradeoff in social insect colonies between the maintenance of potentially beneficial bacterial symbionts and deterrence at the individual and colony level of pathogenic species. They also provide a novel mechanism for recently described social components behind disease resistance in insect colonies, and point toward a potential control strategy for an important bee disease.
Statistical deconvolution of enthalpic energetic contributions to MHC-peptide binding affinity
Authors: Davies Matthew N , Hattotuwagama Channa K , Moss David S , Drew Michael GB , Flower Darren R
Published: April 2006

Background

MHC Class I molecules present antigenic peptides to cytotoxic T cells, which forms an integral part of the adaptive immune response. Peptides are bound within a groove formed by the MHC heavy chain. Previous approaches to MHC Class I-peptide binding prediction have largely concentrated on the peptide anchor residues located at the P2 and C-terminus positions.

Results

A large dataset comprising MHC-peptide structural complexes was created by re-modelling pre-determined x-ray crystallographic structures. Static energetic analysis, following energy minimisation, was performed on the dataset in order to characterise interactions between bound peptides and the MHC Class I molecule, partitioning the interactions within the groove into van der Waals, electrostatic and total non-bonded energy contributions.

Conclusion

The QSAR techniques of Genetic Function Approximation (GFA) and Genetic Partial Least Squares (G/PLS) algorithms were used to identify key interactions between the two molecules by comparing the calculated energy values with experimentally-determined BL50 data. Although the peptide termini binding interactions help ensure the stability of the MHC Class I-peptide complex, the central region of the peptide is also important in defining the specificity of the interaction. As thermodynamic studies indicate that peptide association and dissociation may be driven entropically, it may be necessary to incorporate entropic contributions into future calculations.
The posterior communicating arteries in the patients with sudden deafness: evaluation with magnetic resonance imaging (MRA)
Authors: Tsushima Yoshito , Taketomi-Takahashi Ayako , Endo Keigo
Published: April 2006

Background

A strong association was suggested between a non-functioning posterior communicating artery (Pcom) of the circle of Willis and sudden deafness (SD). The purpose of this study was to determine the rate of depiction of Pcom on magnetic resonance angiography (MRA) in patients with SD.

Methods

Sixteen patients with SD (47.7 +/- 13.3 years; range, 24 – 76 years; nine males) were evaluated with intracranial MRA as well as magnetic resonance imaging (MRI) of the head. The depiction of Pcom on MRA was correlated with the laterality of SD. One hundred twenty-eight controls (49.1 +/- 8.4 years; range, 22 – 66 years; 87 male) were selected from neurologically normal subjects who underwent MR examinations as a part of an annual medical check-up in our hospital.

Results

Four (25%) of 16 SD patients had bilateral Pcom on MRA, four patients had unilateral Pcom and eight patients had bilaterally absent Pcom These results were not significantly different from the controls (p = 0.96). In 6 (37.5 %) of 16 SD patients, the ipsilateral Pcom was present on MRA, and 104 (40.6%) of 256 Pcom were present in 128 normal controls (p = 0.81).

Conclusion

Since there was no link between the occurrence of SD and the absence of the ipsilateral Pcom, our results cannot support the hypothesis that the absence of Pcom may be a risk factor for the occurrence of SD.
Neurocognitive function in children with compensated hypothyroidism: lack of short term effects on or off thyroxin
Authors: Aijaz Naghma J , Flaherty Evelyn M , Preston Thomas , Bracken Stacey Storch , Lane Andrew H , Wilson Thomas A
Published: April 2006

Background

Although thyroxin therapy clearly is beneficial to children with frank hypothyroidism there is little data on the effects of thyroxin in children with compensated or subclinical hypothyroidism. The objective of this study was to determine the effect of thyroxin therapy on cognitive function in children with compensated hypothyroidism. The hypothesis was that thyroxin therapy would change neuropsychological function.

Methods

Eleven patients with a history of sub clinical hypothyroidism entered the study. At the start of the study, six out of the 11 were on thyroxin therapy, while 5 were off therapy. All patients underwent a battery of neuropsychological testing and thyroid function tests at the start of study. Based on the results of thyroid function tests, two of the 5 patients who were off thyroxin were started back on thyroxin. All of the 6 patients who were on thyroxin were taken off thyroxin. All patients then underwent repeat neuropsychological testing and thyroid functions after an average of 91 days.

Results

Thyroxin therapy could not be shown to have an effect on neuropsychological function in this short term study. Our patients had attention problems as compared to the normal population. No significant differences were found between our subjects and normal population standards in verbal processing, visual processing, motor speed/coordination and achievement.

Conclusion

In this small, short term study, thyroxin therapy could not be shown to affect neuropsychological function in children with compensated hypothyroidism. These children may have attention problems but appear to have normal verbal and visual processing, motor speed/coordination and achievement.
Validity of measures of pain and symptoms in HIV/AIDS infected households in resources poor settings: results from the Dominican Republic and Cambodia
Authors: Pappas Gregory , Wolf R Cameron , Morineau Guy , Harding Richard
Published: April 2006

Background

HIV/AIDS treatment programs are currently being mounted in many developing nations that include palliative care services. While measures of palliative care have been developed and validated for resource rich settings, very little work exists to support an understanding of measurement for Africa, Latin America or Asia.

Methods

This study investigates the construct validity of measures of reported pain, pain control, symptoms and symptom control in areas with high HIV-infected prevalence in Dominican Republic and Cambodia Measures were adapted from the POS (Palliative Outcome Scale). Households were selected through purposive sampling from networks of people living with HIV/AIDS. Consistencies in patterns in the data were tested used Chi Square and Mantel Haenszel tests.

Results

The sample persons who reported chronic illness were much more likely to report pain and symptoms compared to those not chronically ill. When controlling for the degrees of pain, pain control did not differ between the chronically ill and non-chronically ill using a Mantel Haenszel test in both countries. Similar results were found for reported symptoms and symptom control for the Dominican Republic. These findings broadly support the construct validity of an adapted version of the POS in these two less developed countries.

Conclusion

The results of the study suggest that the selected measures can usefully be incorporated into population-based surveys and evaluation tools needed to monitor palliative care and used in settings with high HIV/AIDS prevalence.
Screening of Tanzanian medicinal plants for anti-Candida activity
Authors: Runyoro Deborah KB , Matee Mecky IN , Ngassapa Olipa D , Joseph Cosam C , Mbwambo Zakaria H
Published: April 2006

Background

Candida albicans has become resistant to the already limited, toxic and expensive anti-Candida agents available in the market. These factors necessitate the search for new anti-fungal agents.

Methods

Sixty-three plant extracts, from 56 Tanzanian plant species obtained through the literature and interviews with traditional healers, were evaluated for anti-Candida activity. Aqueous methanolic extracts were screened for anti-Candida activity by bioautography agar overlay method, using a standard strain of Candida albicans (ATCC 90028).

Results

Twenty- seven (48%) out of the 56 plants were found to be active. Extracts of the root barks of Albizia anthelmintica and Balanites aegyptiaca, and roots of Plectranthus barbatus showed strong activity.

Conclusion

The extracts that showed strong anti-Candida activity are worth of further investigation in order to isolate and identify the active compounds.
Measuring changes in self-concept: a qualitative evaluation of outcome questionnaires in people having acupuncture for their chronic health problems
Authors: Paterson Charlotte
Published: April 2006

Background

Changes in self-concept are an important potential outcome for many interventions for people with long-term conditions. This study sought to identify and evaluate outcome questionnaires suitable for quantifying changes in self-concept in people with long-term conditions, in the context of treatment with acupuncture and Chinese medicine.

Methods

A literature search was followed by an evaluation of three questionnaires: The Wellbeing Questionnaire W-BQ12, the Patient Enablement Instrument (PEI), and the Arizona Integrative Outcome Scale (AIOS). A convenience sample of 23 people completed the questionnaires on two occasions and were interviewed about their experience and their questionnaire responses. All acupuncturists were interviewed.

Results

Changes in self-concept were common and emerged over time. The three questionnaires had different strengths and weaknesses in relation to measuring changes in self-concept. The generic AIOS had face validity and was sensitive to changes in self-concept over time, but it lacked specificity. The PEI was sensitive and specific in measuring these changes but had lower acceptability. The sensitivity of the W-BQ12 was affected by initial high scores (ceiling effect) and a shorter timescale but was acceptable and is suitable for repeated administration. The PEI and W-BQ12 questionnaires worked well in combination.

Conclusion

Changes in self-concept are important outcomes of complex interventions for people with long-term illness and their measurement requires carefully evaluated tools and long-term follow-up. The literature review and the analysis of the strengths and weaknesses of the questionnaires is a resource for other researchers. The W-BQ12 and the PEI both proved useful for this population and a larger quantitative study is planned.
Evaluation of a multifaceted "Resident-as-Teacher" educational intervention to improve morning report
Authors: James Matthew T , Mintz Marcy J , McLaughlin Kevin
Published: April 2006

Background

Resident-led morning report is an integral part of most residency programs and is ranked among the most valuable of educational experiences. The objectives of this study were to evaluate the effect of a resident-as-teacher educational intervention on the educational and teaching experience of morning report.

Methods

All senior internal medicine residents were invited to participate in this study as teaching participants. All internal medicine residents and clerks were invited to participate as audience participants. The educational intervention included reading material, a small group session and feedback after teaching sessions. The educational and teaching experiences were rated prior to and three months after the intervention using questionnaires.

Results

Forty-six audience participants and 18 teaching participants completed the questionnaires. The degree to which morning report met the educational needs of the audience was higher after the educational intervention (effect size, d = 0.26, p = 0.01). The perceptions of the audience were that delivery had improved and that the sessions were less intimidating and more interactive. The perception of the teaching participants was that delivery was less stressful, but this group now reported greater difficulty in engaging the audience and less confidence in their medical knowledge.

Conclusion

Following the educational intervention the audience's perception was that the educational experience had improved although there were mixed results for the teaching experience. When evaluating such interventions it is important to evaluate the impact on both the educational and teaching experiences as results may differ.
Differences in per capita rates of revascularization and in choice of revascularization procedure for eleven states
Authors: Hannan Edward L , Wu Chuntao , Chassin Mark R
Published: April 2006

Background

A few studies have investigated differences in elective procedure rates across small and medium sized referral regions. The purposes of this study are to investigate differences in revascularizations across 11 entire states and to investigate differences in choice of revascularization procedure (percutaneous coronary intervention (PCI) vs. coronary artery bypass graft (CABG) surgery).

Methods

Age-sex adjusted rates per 100,000 population who were 20 or older were calculated for PCI, CABG surgery, and total revascularization for each state. Also, the risk-adjusted proportion of revascularized patients who underwent PCI was calculated for each state and differences were compared.

Results

We found variations in procedures performed per capita of 1.83-fold for PCI, 1.54-fold for CABG surgery, and 1.54-fold for total revascularization. For patients undergoing revascularization of two or more vessels, the age/sex adjusted maximum rate of 224 per 100,000 population over 20 years old in Florida was 53% higher than the minimum rate of 146 in Colorado. Higher catheterization rates per 1,000 Medicare enrollees and higher percent of white patients were significant predictors of higher revascularization rates, and density of specialists was a significant predictor of catheterization rate. The risk-adjusted percentage of revascularized patients with two or more arteries attempted who underwent PCI ranged from 10.4% in Oregon to 29.0% in Iowa.

Conclusion

There are reasonably large differences among states in total revascularization rates and in type of revascularization among revascularization. These differences appear to be related to practice pattern differences. Future effort should be devoted to understanding the reason for these differences and the impact on patients' health and survival.
Lipopolysaccharide regulated protein expression is only partly impaired in monocytes from patients with type I diabetes
Authors: Wehrwein Gabriele , Neumeier Markus , Schäffler Andreas , Kopp Andrea , Weigert Johanna , Abke Sabine , Schölmerich Jürgen , Buechler Christa
Published: April 2006

Background

Monocytes play an important role in innate immunity and atherosclerosis. A disturbed secretion of cytokines in lipopolysaccharide (LPS) activated monocytes from type 1 diabetes (T1D) patients has been described and may contribute to the impaired inflammatory response in these individuals. In the present study the influence of LPS on five different proteins with a function in immunity and atherosclerosis was analyzed in monocytes from controls and T1D patients.

Methods

Monocytes were isolated from controls and T1D patients and the LPS-stimulated increase of IL-6, CXCL8, monocyte chemotactic protein 1 (CCL2, MCP-1) and superoxide dismutase (SOD 2), as well as the LPS-mediated decrease of apolipoprotein E (Apo E) in primary human monocytes from controls and T1D patients was determined.

Results

CCL2 and IL-6 secretion in response to LPS was found significantly reduced in monocytes from T1D patients when compared to controls whereas basal CCL2 release was similar in control and T1D cells. In contrast, CXCL8 and apolipoprotein E secretion and SOD 2 expression upon LPS stimulation is similar from T1D and control monocytes.

Conclusion

These data indicate that LPS-mediated protein expression is only partly disturbed in monocytes from T1D patients. Reduced secretion of IL-6 and CCL2 in activated monocytes of these patients may contribute to an impaired inflammatory response and vascular disease.
Intensification of the aerobic bioremediation of an actual site soil historically contaminated by polychlorinated biphenyls (PCBs) through bioaugmentation with a non acclimated, complex source of microorganisms
Authors: Di Toro Sara , Zanaroli Giulio , Fava Fabio
Published: April 2006

Background

The biotreatability of actual-site polychlorinated biphenyl (PCB)-contaminated soils is often limited by their poor content of autochthonous pollutant-degrading microorganisms. In such cases, inoculation might be the solution for a successful bioremediation. Some pure and mixed cultures of characterized PCB degrading bacteria have been tested to this purpose. However, several failures have been recorded mostly due to the inability of inoculated microbes to compete with autochthonous microflora and to face the toxicity and the scarcity of nutrients occurring in the contaminated biotope. Complex microbial systems, such as compost or sludge, normally consisting of a large variety of robust microorganisms and essential nutrients, would have better chances to succeed in colonizing degraded contaminated soils. However, such sources of microorganisms have been poorly applied in soil bioremediation and in particular in the biotreatment of soil with PCBs. Thus, in this study the effects of Enzyveba, i.e. a consortium of non-adapted microorganisms developed from composted material, on the slurry- and solid-phase aerobic bioremediation of an actual-site, aged PCB-contaminated soil were studied.

Results

A slow and only partial biodegradation of low-chlorinated biphenyls, along with a moderate depletion of initial soil ecotoxicity, were observed in the not-inoculated reactors. Enzyveba significantly increased the availability and the persistence of aerobic PCB- and chlorobenzoic acid-degrading cultivable bacteria in the bioreactors, in particular during the earlier phase of treatment. It also markedly enhanced PCB-biodegradation rate and extent (from 50 to 100%) as well as the final soil detoxification, in particular under slurry-phase conditions. Taken together, data obtained suggest that Enzyveba enhanced the biotreatability of the selected soil by providing exogenous bacteria and fungi able to remove inhibitory or toxic intermediates of PCB biodegradation and/or exogenous nutrients able to sustain microorganisms in charge for PCB mineralization.

Conclusion

Enzyveba appears a promising agent for bioaugmenting actual-site PCB-polluted soils with a native low content of indigenous specialized microflora. This not only for its positive effects on the soil biotreatability but also for its availability on the market at a relatively low cost.
Multicellular Tumour Spheroid as a model for evaluation of [18F]FDG as biomarker for breast cancer treatment monitoring
Authors: Monazzam Azita , Razifar Pasha , Simonsson Martin , Qvarnström Fredrik , Josephsson Raymond , Blomqvist Carl , Långström Bengt , Bergström Mats
Published: April 2006

Background

In order to explore a pre-clinical method to evaluate if [18F]FDG is valid for monitoring early response, we investigated the uptake of FDG in Multicellular tumour spheroids (MTS) without and with treatment with five routinely used chemotherapy agents in breast cancer.

Methods

The response to each anticancer treatment was evaluated by measurement of the [18F]FDG uptake and viable volume of the MTSs after 2 and 3 days of treatment.

Results

The effect of Paclitaxel and Docetaxel on [18F]FDG uptake per viable volume was more evident in BT474 (up to 55% decrease) than in MCF-7 (up to 25% decrease).

Doxorubicin reduced the [18F]FDG uptake per viable volume more noticeable in MCF-7 (25%) than in BT474 MTSs.

Tamoxifen reduced the [18F]FDG uptake per viable volume only in MCF-7 at the highest dose of 1 μM.

No effect of Imatinib was observed.

Conclusion

MTS was shown to be appropriate to investigate the potential of FDG-PET for early breast cancer treatment monitoring; the treatment effect can be observed before any tumour size changes occur.

The combination of PET radiotracers and image analysis in MTS provides a good model to evaluate the relationship between tumour volume and the uptake of metabolic tracer before and after chemotherapy. This feature could be used for screening and selecting PET-tracers for early assessment of treatment response.

In addition, this new method gives a possibility to assess quickly, and in vitro, a good preclinical profile of existing and newly developed anti-cancer drugs.
A preliminary study of placental umbilical cord whole blood transfusion in under resourced patients with malaria in the background of anaemia
Authors: Bhattacharya Niranjan
Published: April 2006

Background

Malaria is an annual killer of over one million people globally and its essential co-morbidity is anaemia. Cord blood, because of its rich mix of foetal and adult haemoglobin, high platelet and WBC counts, hypo-antigenic nature, altered metabolic profile and high affinity for oxygen as well as its anti-malarial effect, is an ideal choice in malaria with anaemia, necessitating blood transfusion.

Methods

This paper presents an alternative protocol for fresh whole blood/packed cell transfusion from the hospital's biological waste resources, i.e., the placenta, after the birth of a healthy baby from a healthy mother. This collected blood was routinely transfused to patients admitted in our hospital with severe anaemia in the background of confirmed malaria. 94 units of placental umbilical cord whole blood were collected after lower uterine caesarean section (LUCS) from consenting mothers (from 1st April 1999 to April 2005), and safely transfused to 39 informed, consenting patients (age varying from 8 to 72 years). The collected volume of cord blood from each placenta (Unit) varied from 52 ml to 143 ml, with a mean packed cell volume of 48.9 ± 4.1 SD and a mean haemoglobin concentration of 16.4 Gm percent ± 1.6 Gm percent SD. The blood was immediately transfused after following the standard adult blood transfusion protocol of screening and cross-matching between the donor and the recipient. On occasion, the collected cord blood was preserved in the refrigerator, if no volunteer was readily available, and transfused within 72 hours of collection.

Results

Cord blood transfusion was tested on twenty two patients infected with Plasmodium falciparum and 17 patients with Plasmodium vivax. For inclusion in this study, the patient's plasma haemoglobin had to be 8 gm percent or less (the pre-transfusion haemoglobin in the malaria-infected patients in this series varied from 5.4 gm/dl to 7.9 gm/dl). The rise of haemoglobin within 72 hours of two units of freshly collected cord blood transfusion was 0.5 gm/dl to 1.6 gm/dl. Each patient received two to six units of freshly collected cord blood transfusion (two units at a time), depending on availability and compatibility. No clinical immunological or non-immunological reaction has been encountered in this series.

Conclusion

Properly screened cord blood is safe for transfusion, in victims of severe malarial anaemia who need transfusion support.
Spatial variability in the density, distribution and vectorial capacity of anopheline species in a high transmission village (Equatorial Guinea)
Authors: Cano Jorge , Descalzo Miguel Ángel , Moreno Marta , Chen Zhaoguo , Nzambo Sisinio , Bobuakasi Leonardo , Buatiche Jesús N , Ondo Melchor , Micha Francisco , Benito Agustín
Published: April 2006

Background

Malaria transmission varies from one country to another and there are also local differences in time and space. An important variable when explaining the variability in transmission is the breeding behaviour of the different vector species and the availability of breeding sites. The aim of this study was to determine the geographical variability of certain entomological parameters: human biting rate (HBR), sporozoitic index (SI) for Plasmodium falciparum and entomological inoculation rate (EIR).

Methods

The study was carried out in a small village in the mainland region of Equatorial Guinea. Adult mosquitoes were collected by CDC light traps. Polymerase Chain Reaction was employed to identify the species within the Anopheles gambiae complex and to detect P. falciparum sporozoites. The geographical position of all the dwellings in the village were taken using a global positioning system receiver unit. Data relating to the dwelling, occupants, use of bednets and the mosquitoes collection data were used to generate a geographical information system (GIS). This GIS allowed the minimum distance of the dwellings to the closest water point (potential breeding sites) to be determined.

Results

A total of 1,173 anophelines were caught: 279 A. gambiae s.l. (217 A. gambiae s.s. and one Anopheles melas), 777 Anopheles moucheti and 117 Anopheles carnevalei. A. moucheti proved to be the main vector species and was responsible for 52.38 [95% IC: 33.7–71] night infective bites during this period. The highest SI was found in A. carnevalei (24%), even though the HBR was the lowest for this species. A significant association was found between the distance from the dwellings to the closest water point (River Ntem or secondary streams) and the total HBR.

Conclusion

A clear association has been observed between the distance to potential breeding sites and the variability in the anopheline density, while the other parameters measured do not seem to condition this spatial variability. The application of GIS to the study of vector-transmitted diseases considerably improves the management of the information obtained from field surveys and facilitates the study of the distribution patterns of the vector species.
Using green fluorescent malaria parasites to screen for permissive vector mosquitoes
Authors: Frischknecht Friedrich , Martin Beatrice , Thiery Isabelle , Bourgouin Catherine , Menard Robert
Published: April 2006

Background

The Plasmodium species that infect rodents, particularly Plasmodium berghei and Plasmodium yoelii, are useful to investigate host-parasite interactions. The mosquito species that act as vectors of human plasmodia in South East Asia, Africa and South America show different susceptibilities to infection by rodent Plasmodium species. P. berghei and P. yoelii infect both Anopheles gambiae and Anopheles stephensi, which are found mainly in Africa and Asia, respectively. However, it was reported that P. yoelii can infect the South American mosquito, Anopheles albimanus, while P. berghei cannot.

Methods

P. berghei lines that express the green fluorescent protein were used to screen for mosquitoes that are susceptible to infection by P. berghei. Live mosquitoes were examined and screened for the presence of a fluorescent signal in the abdomen. Infected mosquitoes were then examined by time-lapse microscopy to reveal the dynamic behaviour of sporozoites in haemolymph and extracted salivary glands.

Results

A single fluorescent oocyst can be detected in live mosquitoes and P. berghei can infect A. albimanus. As in other mosquitoes, P. berghei sporozoites can float through the haemolymph and invade A. albimanus salivary glands and they are infectious in mice after subcutaneous injection.

Conclusion

Fluorescent Plasmodium parasites can be used to rapidly screen susceptible mosquitoes. These results open the way to develop a laboratory model in countries where importation of A. gambiae and A. stephensi is not allowed.
Lack of association between putative transporter gene polymorphisms in Plasmodium falciparum and chloroquine resistance in imported malaria isolates from Africa
Authors: Cojean Sandrine , Noël Alain , Garnier Dimitri , Hubert Véronique , Le Bras Jacques , Durand Rémy
Published: April 2006

Background

Plasmodium falciparum drug resistance represents a major health problem in malaria endemic countries. The mechanisms of resistance are not fully elucidated. Recently, an association between putative transporter gene polymorphisms and in vitro response to chloroquine (CQ) and quinine has been reported in culture-adapted, cloned isolates from various geographical origins. However, this was not confirmed in another study performed on isolates from a defined region in Thailand.

Methods

This study tried to find an association between putative transporters gene polymorphisms with in vitro response to CQ and pfcrt genotype in isolates originating from various African countries. To avoid biases of parasites adaptation in culture, fresh isolates obtained from symptomatic, malaria-infected travellers returning from Africa to France were used. Monoclonal isolates included in the study were selected using a msp-2 fragment analysis method. In vitro susceptibility to CQ, single nucleotide polymorphisms and microsatellite polymorphisms in pfcrt, pfmdr1 and six putative transporter genes were established in 27 isolates and three reference strains.

Results

Polymorphism of pfcrt at positions 76 and 220 showed a significant association with in vitro chloroquine resistance (P < .02 and P < .05 respectively). Polymorphism of pfmdr1 at position 86 showed an equally significant association with in vitro chloroquine response (P < .05). No association was found between SNPs or microsatellite polymorphisms of putative transporter genes and in vitro CQR or pfcrt genotype in imported malaria isolates from Africa.

Conclusion

The previously described association between putative transporter gene polymorphisms and in vitro response to chloroquine (CQ) was not confirmed in the present study.
The capacity of short-chain fructo-oligosaccharides to stimulate faecal bifidobacteria: a dose-response relationship study in healthy humans
Authors: Bouhnik Yoram , Raskine Laurent , Simoneau Guy , Paineau Damien , Bornet Francis
Published: April 2006

Background

Short-chain fructo-oligosaccharides (scFOS) are well-known for their bifidogenicity. In a large study comprising 200 healthy volunteers, we determined the bifidogenic properties of 7 non-digestible carbohydrates administered at a dose of 10 g/d in the diet; we analysed dose-response relationships of the bifidogenic substrates at doses ranging from 2.5 to 10 g/d in comparison with a placebo. The aim of this presentation is to give more details about the dose-response effects of short-chain fructo-oligosaccharides (scFOS).

Methods

Forty healthy volunteers (18 males, 22 females) eating their usual diets were randomly divided into 5 groups of 8 subjects and received scFOS at a dose of 2.5, 5.0, 7.5 and 10 g/d or a placebo for 7 d. Stools were collected before (day (d) 8) and at the end (day (d) 15) of sugar consumption, and tolerance was evaluated using a daily chart.

Results (m ± SEM)

Bifidobacteria counts increase was higher in scFOS than in placebo group for all doses tested [2.5 g/d (from 9.15 ± 0.59 to 9.39 ± 0.70; P = 0.02); 5 g/d (from 10.21 ± 0.21 to 10.67 ± 0.22; P = 0.03); 7.5 g/d (from 9.28 ± 0.49 to 9.85 ± 0.35;P = 0.01); 10 g/d (from 9.00 ± 0.81 to 10.18 ± 0.60; P = 0.003)]. A significant correlation between the ingested dose of scFOS and faecal bifidobacteria counts was observed at d15 (r2= 0.307, P < 0.001). Total anaerobes increased at the dose of 10 g/d. No significant differences were found for Bacteroides, Lactobacillus, enterobacteria or pH in any group. The frequency of digestive symptoms was not different between scFOS at any of the doses tested and placebo. Bloating was significantly more intense during scFOS ingestion at doses of 2.5 and 5 g/d, but not at doses of 7.5 and 10 g/d. Excess flatus, borborygmi and abdominal pain did not differ from the placebo at any of the doses tested.

Conclusion

This study showed that scFOS is bifidogenic and well tolerated at doses ranging from 2.5 to 10 g/d, and that there is a dose-response relationship in healthy volunteers.
Antimicrobial titanium/silver PVD coatings on titanium
Authors: Ewald Andrea , Glückermann Susanne K , Thull Roger , Gbureck Uwe
Published: April 2006

Background

Biofilm formation and deep infection of endoprostheses is a recurrent complication in implant surgery. Post-operative infections may be overcome by adjusting antimicrobial properties of the implant surface prior to implantation. In this work we described the development of an antimicrobial titanium/silver hard coating via the physical vapor deposition (PVD) process.

Methods

Coatings with a thickness of approximately 2 μm were deposited on titanium surfaces by simultaneous vaporisation of both metals in an inert argon atmosphere with a silver content of approximately 0.7 – 9% as indicated by energy dispersive X-ray analysis. On these surfaces microorganisms and eukaryotic culture cells were grown.

Results

The coatings released sufficient silver ions (0.5–2.3 ppb) when immersed in PBS and showed significant antimicrobial potency againstStaphylococcus epidermisandKlebsiella pneumoniaestrains. At the same time, no cytotoxic effects of the coatings on osteoblast and epithelial cells were found.

Conclusion

Due to similar mechanical performance when compared to pure titanium, the TiAg coatings should be suitable to provide antimicrobial activity on load-bearing implant surfaces.
Recreational and occupational field exposure to freshwater cyanobacteria – a review of anecdotal and case reports, epidemiological studies and the challenges for epidemiologic assessment
Authors: Stewart Ian , Webb Penelope M , Schluter Philip J , Shaw Glen R
Published: April 2006

Cyanobacteria are common inhabitants of freshwater lakes and reservoirs throughout the world. Under favourable conditions, certain cyanobacteria can dominate the phytoplankton within a waterbody and form nuisance blooms. Case reports and anecdotal references dating from 1949 describe a range of illnesses associated with recreational exposure to cyanobacteria: hay fever-like symptoms, pruritic skin rashes and gastro-intestinal symptoms are most frequently reported. Some papers give convincing descriptions of allergic reactions while others describe more serious acute illnesses, with symptoms such as severe headache, pneumonia, fever, myalgia, vertigo and blistering in the mouth. A coroner in the United States found that a teenage boy died as a result of accidentally ingesting a neurotoxic cyanotoxin from a golf course pond. This death is the first recorded human fatality attributed to recreational exposure to cyanobacteria, although uncertainties surround the forensic identification of the suspected cyanotoxin in this case.

We systematically reviewed the literature on recreational exposure to freshwater cyanobacteria. Epidemiological data are limited, with six studies conducted since 1990. Statistically significant increases in symptoms were reported in individuals exposed to cyanobacteria compared to unexposed counterparts in two Australian cohort studies, though minor morbidity appeared to be the main finding. The four other small studies (three from the UK, one Australian) did not report any significant association. However, the potential for serious injury or death remains, as freshwater cyanobacteria under bloom conditions are capable of producing potent toxins that cause specific and severe dysfunction to hepatic or central nervous systems. The exposure route for these toxins is oral, from ingestion of recreational water, and possibly by inhalation.

A range of freshwater microbial agents may cause acute conditions that present with features that resemble illnesses attributed to contact with cyanobacteria and, conversely, acute illness resulting from exposure to cyanobacteria or cyanotoxins in recreational waters could be misdiagnosed. Accurately assessing exposure to cyanobacteria in recreational waters is difficult and unreliable at present, as specific biomarkers are unavailable. However, diagnosis of cyanobacteria-related illness should be considered for individuals presenting with acute illness following freshwater contact if a description is given of a waterbody visibly affected by planktonic mass development.
Cyanobacterial lipopolysaccharides and human health – a review
Authors: Stewart Ian , Schluter Philip J , Shaw Glen R
Published: April 2006

Cyanobacterial lipopolysaccharide/s (LPS) are frequently cited in the cyanobacteria literature as toxins responsible for a variety of heath effects in humans, from skin rashes to gastrointestinal, respiratory and allergic reactions. The attribution of toxic properties to cyanobacterial LPS dates from the 1970s, when it was thought that lipid A, the toxic moiety of LPS, was structurally and functionally conserved across all Gram-negative bacteria. However, more recent research has shown that this is not the case, and lipid A structures are now known to be very different, expressing properties ranging from LPS agonists, through weak endotoxicity to LPS antagonists. Although cyanobacterial LPS is widely cited as a putative toxin, most of the small number of formal research reports describe cyanobacterial LPS as weakly toxic compared to LPS from the Enterobacteriaceae.

We systematically reviewed the literature on cyanobacterial LPS, and also examined the much lager body of literature relating to heterotrophic bacterial LPS and the atypical lipid A structures of some photosynthetic bacteria. While the literature on the biological activity of heterotrophic bacterial LPS is overwhelmingly large and therefore difficult to review for the purposes of exclusion, we were unable to find a convincing body of evidence to suggest that heterotrophic bacterial LPS, in the absence of other virulence factors, is responsible for acute gastrointestinal, dermatological or allergic reactions via natural exposure routes in humans.

There is a danger that initial speculation about cyanobacterial LPS may evolve into orthodoxy without basis in research findings. No cyanobacterial lipid A structures have been described and published to date, so a recommendation is made that cyanobacteriologists should not continue to attribute such a diverse range of clinical symptoms to cyanobacterial LPS without research confirmation.
Tabebuia avellanedae naphthoquinones: activity against methicillin-resistant staphylococcal strains, cytotoxic activity and in vivo dermal irritability analysis
Authors: Pereira Eliezer Menezes , Machado Thelma de Barros , Leal Ivana Correa Ramos , Jesus Desyreé Murta , Damaso Clarissa Rosa de Almeida , Pinto Antonio Ventura , Giambiagi-deMarval Marcia , Kuster Ricardo Machado , dos Santos Kátia Regina Netto
Published: April 2006

Background

Methicillin-resistantStaphylococcus aureus(MRSA) and coagulase-negative staphylococcus infections are a worldwide concern. Currently, these isolates have also shown resistance to vancomycin, the last therapy used in these cases. It has been observed that quinones and other related compounds exhibit antibacterial activity. This study evaluated the antibacterial activity, toxicity andin vivodermal irritability of lapachol extracted fromTabebuia avellanedaeand derivatives against methicillin-resistant staphylococcal isolates. In addition, its mechanism of action was also analyzed.

Methods

The compounds β-lapachone, 3-hydroxy βNlapachone and α-lapachone were tested to determine the MIC values against methicillin-resistantS. aureus,S. epidermidisandS. haemolyticusstrains, being the two last ones hetero-resistant to vancomycin. Experiments of protein synthesis analysis to investigate the naphthoquinones action were assessed.In vitrotoxicity to eukaryotic BSC-40 African Green Monkey Kidney cell cultures andin vivoprimary dermal irritability in healthy rabbits were also performed.

Results

The compounds tested showed antibacterial activity (MICs of 8, 4/8 and 64/128 μg/mL to β-lapachone, 3-hydroxy β N lapachone and α-lapachone, respectively), but no bactericidal activity was observed (MBC > 512 μg/mL for all compounds). Although it has been observed toxic effect in eukaryotic cells, the compounds were shown to be atoxic when applied as topic preparations in healthy rabbits. No inhibition of proteins synthesis was observed.

Conclusion

Our results suggest that quinones could be used in topic preparations against wound infections caused by staphylococci, after major investigation of the pharmacological properties of the compounds. Studies about the use of these compounds on tumoral cells could be carried on, due to their effect in eukaryotic cells metabolism.
In vitro and in vivo effects of the PPAR-alpha agonists fenofibrate and retinoic acid in endometrial cancer
Authors: Saidi Samir A , Holland Cathrine M , Charnock-Jones D Stephen , Smith Stephen K
Published: April 2006

Fenofibrate, an agonist of PPAR-alpha, in doses above 25 μM, inhibits proliferation and induces apoptosis in Ishikawa endometrial cancer cells. We show that these effects are potentiated by retinoic acid, an agonist of the retinoid-X-receptor. DNA content analysis shows that G1/S phase progression through the cell cycle is inhibited. Independent Component Analysis of gene microarray experiments demonstrated downregulation of Cyclin D1 (CCND1) and associated changes in cell cycle gene expression. Expression of PPAR-alpha mRNA was reduced by >75% using RNA-interference but this resulted in only minor changes in biological effects. A nude mouse model of endometrial carcinoma was used to investigate the effect of fenofibratein vivobut failed to show consistent inhibition of tumour growth.

Conclusion

The combination of fenofibrate and retinoic acid is a potent inhibitor of Ishikawa endometrial cancer cell growthin vitro.
Short-term duodenal seal oil administration normalised n-6 to n-3 fatty acid ratio in rectal mucosa and ameliorated bodily pain in patients with inflammatory bowel disease
Authors: Bjørkkjær Tormod , Brun Johan G , Valen Merete , Arslan Gülen , Lind Ragna , Brunborg Linn A , Berstad Arnold , Frøyland Livar
Published: April 2006

Background

A high dietary intake of n-6 compared to n-3 fatty acids (FAs) may promote the production of pro-inflammatory eicosanoids and cytokines. In two recent studies, short-term (10-day) duodenal administration of n-3 polyunsaturated fatty acid rich seal oil ameliorated joint pain in patients with inflammatory bowel disease (IBD). Using unpublished data from these two studies we here investigated whether normalisation of the n-6 to n-3 FA ratio in blood and tissues by seal oil administration was associated with improved health related quality of life (HRQOL) as assessed by the generic short-form 36 (SF-36) questionnaire.

Results

In the first pilot study, baseline n-6 to n-3 FA ratio in rectal mucosal biopsies from 10 patients with IBD (9 of those had joint pain) was significantly increased compared with that in 10 control patients without IBD or joint pain. Following seal oil administration, the n-6 to n-3 FA ratio of the IBD-patients was significantly lowered to the level seen in untreated controls. In the subsequent, randomized controlled study (n = 19), seal oil administration reduced the n-6 to n-3 FA ratio in blood similarly and also the SF-36 assessed bodily pain, while n-6 FA rich soy oil administration had no such effect.

Conclusion

In these two separate studies, short-term duodenal administration of seal oil normalised the n-6 to n-3 FA ratio in rectal mucosa and improved the bodily pain dimension of HRQOL of patients with IBD-related joint pain. The possibility of a causal relationship between n-6 to n-3 FA ratio in rectal mucosa and bodily pain in IBD-patients warrants further investigations.