Quantifying the impact of interventions against Plasmodium vivax: A model for country-specific use

In order to evaluate the impact of various intervention strategies on Plasmodium vivax dynamics in low endemicity settings without significant seasonal pattern, we introduce a simple mathematical model that can be easily adapted to reported case numbers similar to that collected by surveillance systems in various countries. The model includes case management, vector control, mass drug administration and reactive case detection interventions and is implemented in both deterministic and stochastic frameworks. It is available as an R package to enable users to calibrate and simulate it with their own data. Although we only illustrate its use on fictitious data, by simulating and comparing the impact of various intervention combinations on malaria risk and burden, this model could be a useful tool for strategic planning, implementation and resource mobilization.

Oncology clinical trial disruption during the COVID-19 pandemic: a COVID-19 and cancer outcomes study

Background

COVID-19 disproportionately impacted patients with cancer as a result of direct infection, and delays in diagnosis and therapy. Oncological clinical trials are resource-intensive endeavors that could be particularly susceptible to disruption by the pandemic, but few studies have evaluated the impact of the pandemic on clinical trial conduct.

Patients and methods

This prospective, multicenter study assesses the impact of the pandemic on therapeutic clinical trials at two large academic centers in the Northeastern United States between December 2019 and June 2021. The primary objective was to assess the enrollment on, accrual to, and activation of oncology therapeutic clinical trials during the pandemic using an institution-wide cohort of (i) new patient accruals to oncological trials, (ii) a manually curated cohort of patients with cancer, and (ii) a dataset of new trial activations.

Results

The institution-wide cohort included 4756 new patients enrolled to clinical trials from December 2019 to June 2021. A major decrease in the numbers of new patient accruals (−46%) was seen early in the pandemic, followed by a progressive recovery and return to higher-than-normal levels (+2.6%). A similar pattern (from −23.6% to +30.4%) was observed among 467 newly activated trials from June 2019 to June 2021. A more pronounced decline in new accruals was seen among academically sponsored trials (versus industry sponsored trials) (P < 0.05). In the manually curated cohort, which included 2361 patients with cancer, non-white patients tended to be more likely taken off trial in the early pandemic period (adjusted odds ratio: 2.60; 95% confidence interval 1.00-6.63), and substantial pandemic-related deviations were recorded.

Conclusions

Substantial disruptions in clinical trial activities were observed early during the pandemic, with a gradual recovery during ensuing time periods, both from an enrollment and an activation standpoint. The observed decline was more prominent among academically sponsored trials, and racial disparities were seen among people taken off trial.

Improving access to care and community health in Haiti with optimized community health worker placement

The national deployment of polyvalent community health workers (CHWs) is a constitutive part of the strategy initiated by the Ministry of Health to accelerate efforts towards universal health coverage in Haiti. Its implementation requires the planning of future recruitment and deployment activities for which mathematical modelling tools can provide useful support by exploring optimised placement scenarios based on access to care and population distribution. We combined existing gridded estimates of population and travel times with optimisation methods to derive theoretical CHW geographical placement scenarios including constraints on walking time and the number of people served per CHW. Four national-scale scenarios that align with total numbers of existing CHWs and that ensure that the walking time for each CHW does not exceed a predefined threshold are compared. The first scenario accounts for population distribution in rural and urban areas only, while the other three also incorporate in different ways the proximity of existing health centres. Comparing these scenarios to the current distribution, insufficient number of CHWs is systematically identified in several departments and gaps in access to health care are identified within all departments. These results highlight current suboptimal distribution of CHWs and emphasize the need to consider an optimal (re-)allocation.

Using observed incidence to calibrate the transmission level of a mathematical model for Plasmodium vivax dynamics including case management and importation

In this work, we present a simple and flexible model for Plasmodium vivax dynamics which can be easily combined with routinely collected data on local and imported case counts to quantify transmission intensity and simulate control strategies. This model extends the model from White et al. (2016) by including case management interventions targeting liver-stage or blood-stage parasites, as well as imported infections. The endemic steady state of the model is used to derive a relationship between the observed incidence and the transmission rate in order to calculate reproduction numbers and simulate intervention scenarios. To illustrate its potential applications, the model is used to calculate local reproduction numbers in Panama and identify areas of sustained malaria transmission that should be targeted by control interventions.

Frontal Fibrosing Alopecia survey of severity assessment methods in routine clinical practice and validation of the IFFACG measurement guidance

BACKGROUND

Lack of validated and responsive outcome measures in the management of Frontal Fibrosing Alopecia (FFA) significantly limits our ability to assess disease progression and treatment response over time.

OBJECTIVES

The aim of this study was to understand how FFA extent and progression is currently assessed in UK specialist centres, validate components of the International FFA Cooperative Group (IFFACG) statement on FFA assessment, and identify pragmatic advice to improve FFA management in clinic.

METHODS

Consultant Dermatologists with a specialist interest in hair loss (n=17) were invited to take part. Preferred FFA assessment methods were explored using questionnaires and clinical scenarios. Participants were asked to identify and mark the current hairline in 10 frontal and 10 temporal hairline images, with assessment repeated 3 months later (to assess intra-individual variability) and 12 months later (to test whether inter-individual accuracy could be improved with simple instruction).

RESULTS

All 17 clinicians (100%) completed the questionnaire at each time interval. We identified a wide variation in assessment techniques between our experts. Measurements were perceived as the most accurate method of assessing frontal recession whereas photography was preferred for temporal recession. Inter-rater reliability between clinicians measuring the frontal hairline scenarios indicated a moderate strength of agreement (ICC 0.613; 95% CI: 0.398 to 0.848), yet intra-rater reliability was found to be poor with wide limits of agreement (-8.71mm to 9.92mm) on follow-up. Importantly, when clear guidance was provided on how the hairline should be identified (questionnaire 3), inter-rater reliability improved significantly, with an ICC 0.702 suggesting moderate agreement (95% CI: 0.508 to 0.890; p<0.001). A similar pattern was seen with temporal hairline measurements, which again improved in accuracy with instruction.

CONCLUSION

We show that accuracy of measurements in FFA can be improved with simple instruction and validate components of the IFFACG measurement recommendations.

Dynamics of the COVID-19 epidemic in Ireland under mitigation

BACKGROUND

In Ireland and across the European Union the COVID-19 epidemic waves, driven mainly by the emergence of new variants of the SARS-CoV-2 have continued their course, despite various interventions from governments. Public health interventions continue in their attempts to control the spread as they wait for the planned significant effect of vaccination.

METHODS

To tackle this challenge and the observed non-stationary aspect of the epidemic we used a modified SEIR stochastic model with time-varying parameters, following Brownian process. This enabled us to reconstruct the temporal evolution of the transmission rate of COVID-19 with the non-specific hypothesis that it follows a basic stochastic process constrained by the available data. This model is coupled with Bayesian inference (particle Markov Chain Monte Carlo method) for parameter estimation and utilized mainly well-documented Irish hospital data.

RESULTS

In Ireland, mitigation measures provided a 78-86% reduction in transmission during the first wave between March and May 2020. For the second wave in October 2020, our reduction estimation was around 20% while it was 70% for the third wave in January 2021. This third wave was partly due to the UK variant appearing in Ireland. In June 2020 we estimated that sero-prevalence was 2.0% (95% CI: 1.2-3.5%) in complete accordance with a sero-prevalence survey. By the end of April 2021, the sero-prevalence was greater than 17% due in part to the vaccination campaign. Finally we demonstrate that the available observed confirmed cases are not reliable for analysis owing to the fact that their reporting rate has as expected greatly evolved.

CONCLUSION

We provide the first estimations of the dynamics of the COVID-19 epidemic in Ireland and its key parameters. We also quantify the effects of mitigation measures on the virus transmission during and after mitigation for the three waves. Our results demonstrate that Ireland has significantly reduced transmission by employing mitigation measures, physical distancing and lockdown. This has to date avoided the saturation of healthcare infrastructures, flattened the epidemic curve and likely reduced mortality. However, as we await for a full roll out of a vaccination programme and as new variants potentially more transmissible and/or more infectious could continue to emerge and mitigation measures change silent transmission, challenges remain.

A mechanistic and data-driven reconstruction of the time-varying reproduction number: Application to the COVID-19 epidemic

The effective reproduction number Reff is a critical epidemiological parameter that characterizes the transmissibility of a pathogen. However, this parameter is difficult to estimate in the presence of silent transmission and/or significant temporal variation in case reporting. This variation can occur due to the lack of timely or appropriate testing, public health interventions and/or changes in human behavior during an epidemic. This is exactly the situation we are confronted with during this COVID-19 pandemic. In this work, we propose to estimate Reff for the SARS-CoV-2 (the etiological agent of the COVID-19), based on a model of its propagation considering a time-varying transmission rate. This rate is modeled by a Brownian diffusion process embedded in a stochastic model. The model is then fitted by Bayesian inference (particle Markov Chain Monte Carlo method) using multiple well-documented hospital datasets from several regions in France and in Ireland. This mechanistic modeling framework enables us to reconstruct the temporal evolution of the transmission rate of the COVID-19 based only on the available data. Except for the specific model structure, it is non-specifically assumed that the transmission rate follows a basic stochastic process constrained by the observations. This approach allows us to follow both the course of the COVID-19 epidemic and the temporal evolution of its Reff(t). Besides, it allows to assess and to interpret the evolution of transmission with respect to the mitigation strategies implemented to control the epidemic waves in France and in Ireland. We can thus estimate a reduction of more than 80% for the first wave in all the studied regions but a smaller reduction for the second wave when the epidemic was less active, around 45% in France but just 20% in Ireland. For the third wave in Ireland the reduction was again significant (>70%).

Parallel trends in the transmission of SARS-CoV-2 and retail/recreation and public transport mobility during non-lockdown periods

Recent literature strongly supports the hypothesis that mobility restriction and social distancing play a crucial role in limiting the transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). During the first wave of the coronavirus disease 2019 (COVID-19) pandemic, it was shown that mobility restriction reduced transmission significantly. This study found that, in the period between the first two waves of the COVID-19 pandemic, there was high positive correlation between trends in the transmission of SARS-CoV-2 and mobility. These two trends oscillated simultaneously, and increased mobility following the relaxation of lockdown rules was significantly associated with increased transmission. From a public health perspective, these results highlight the importance of tracking changes in mobility when relaxing mitigation measures in order to anticipate future changes in the spread of SARS-CoV-2.

Predicting the impact of outdoor vector control interventions on malaria transmission intensity from semi-field studies

BACKGROUND

Semi-field experiments with human landing catch (HLC) measure as the outcome are an important step in the development of novel vector control interventions against outdoor transmission of malaria since they provide good estimates of personal protection. However, it is often infeasible to determine whether the reduction in HLC counts is due to mosquito mortality or repellency, especially considering that spatial repellents based on volatile pyrethroids might induce both. Due to the vastly different impact of repellency and mortality on transmission, the community-level impact of spatial repellents can not be estimated from such semi-field experiments.

METHODS

We present a new stochastic model that is able to estimate for any product inhibiting outdoor biting, its repelling effect versus its killing and disarming (preventing host-seeking until the next night) effects, based only on time-stratified HLC data from controlled semi-field experiments. For parameter inference, a Bayesian hierarchical model is used to account for nightly variation of semi-field experimental conditions. We estimate the impact of the products on the vectorial capacity of the given Anopheles species using an existing mathematical model. With this methodology, we analysed data from recent semi-field studies in Kenya and Tanzania on the impact of transfluthrin-treated eave ribbons, the odour-baited Suna trap and their combination (push-pull system) on HLC of Anopheles arabiensis in the peridomestic area.

RESULTS

Complementing previous analyses of personal protection, we found that the transfluthrin-treated eave ribbons act mainly by killing or disarming mosquitoes. Depending on the actual ratio of disarming versus killing, the vectorial capacity of An. arabiensis is reduced by 41 to 96% at 70% coverage with the transfluthrin-treated eave ribbons and by 38 to 82% at the same coverage with the push-pull system, under the assumption of a similar impact on biting indoors compared to outdoors.

CONCLUSIONS

The results of this analysis of semi-field data suggest that transfluthrin-treated eave ribbons are a promising tool against malaria transmission by An. arabiensis in the peridomestic area, since they provide both personal and community protection. Our modelling framework can estimate the community-level impact of any tool intervening during the mosquito host-seeking state using data from only semi-field experiments with time-stratified HLC.

Aedes mosquitoes acquire and transmit Zika virus by breeding in contaminated aquatic environments

Zika virus (ZIKV) is a mosquito-borne flavivirus that predominantly circulates between humans and Aedes mosquitoes. Clinical studies have shown that Zika viruria in patients persists for an extended period, and results in infectious virions being excreted. Here, we demonstrate that Aedes mosquitoes are permissive to ZIKV infection when breeding in urine or sewage containing low concentrations of ZIKV. Mosquito larvae and pupae, including from field Aedes aegypti can acquire ZIKV from contaminated aquatic systems, resulting in ZIKV infection of adult females. Adult mosquitoes can transmit infectious virions to susceptible type I/II interferon receptor-deficient (ifnagr-/-) C57BL/6 (AG6) mice. Furthermore, ZIKV viruria from infected AG6 mice can causes mosquito infection during the aquatic life stages. Our studies suggest that infectious urine could be a natural ZIKV source, which is potentially transmissible to mosquitoes when breeding in an aquatic environment.

Comparison of stochastic and deterministic frameworks in dengue modelling

We perform estimations of compartment models for dengue transmission in rural Cambodia with increasing complexity regarding both model structure and the account for stochasticity. On the one hand, we successively account for three embedded sources of stochasticity: observation noise, demographic variability and environmental hazard. On the other hand, complexity in the model structure is increased by introducing vector-borne transmission, explicit asymptomatic infections and interacting virus serotypes. Using two sources of case data from dengue epidemics in Kampong Cham (Cambodia), models are estimated in the bayesian framework, with Markov Chain Monte Carlo and Particle Markov Chain Monte Carlo. We highlight the advantages and drawbacks of the different formulations in a practical setting. Although in this case the deterministic models provide a good approximation of the mean trajectory for a low computational cost, the stochastic frameworks better reflect and account for parameter and simulation uncertainty.

Accounting for non-stationarity in epidemiology by embedding time-varying parameters in stochastic models

The spread of disease through human populations is complex. The characteristics of disease propagation evolve with time, as a result of a multitude of environmental and anthropic factors, this non-stationarity is a key factor in this huge complexity. In the absence of appropriate external data sources, to correctly describe the disease propagation, we explore a flexible approach, based on stochastic models for the disease dynamics, and on diffusion processes for the parameter dynamics. Using such a diffusion process has the advantage of not requiring a specific mathematical function for the parameter dynamics. Coupled with particle MCMC, this approach allows us to reconstruct the time evolution of some key parameters (average transmission rate for instance). Thus, by capturing the time-varying nature of the different mechanisms involved in disease propagation, the epidemic can be described. Firstly we demonstrate the efficiency of this methodology on a toy model, where the parameters and the observation process are known. Applied then to real datasets, our methodology is able, based solely on simple stochastic models, to reconstruct complex epidemics, such as flu or dengue, over long time periods. Hence we demonstrate that time-varying parameters can improve the accuracy of model performances, and we suggest that our methodology can be used as a first step towards a better understanding of a complex epidemic, in situation where data is limited and/or uncertain.

Structure in the variability of the basic reproductive number (R0) for Zika epidemics in the Pacific islands

Before the outbreak that reached the Americas in 2015, Zika virus (ZIKV) circulated in Asia and the Pacific: these past epidemics can be highly informative on the key parameters driving virus transmission, such as the basic reproduction number (R0). We compare two compartmental models with different mosquito representations, using surveillance and seroprevalence data for several ZIKV outbreaks in Pacific islands (Yap, Micronesia 2007, Tahiti and Moorea, French Polynesia 2013-2014, New Caledonia 2014). Models are estimated in a stochastic framework with recent Bayesian techniques. R0 for the Pacific ZIKV epidemics is estimated between 1.5 and 4.1, the smallest islands displaying higher and more variable values. This relatively low range of R0 suggests that intervention strategies developed for other flaviviruses should enable as, if not more effective control of ZIKV. Our study also highlights the importance of seroprevalence data for precise quantitative analysis of pathogen propagation, to design prevention and control strategies.

DOI:http://dx.doi.org/10.7554/eLife.19874.001

Zika virus is an infectious disease primarily transmitted between people by mosquitoes. While most people develop mild flu-like symptoms, infection during pregnancy can interfere with how the baby’s head and brain develop. Until recently, the virus had only been seen sporadically in Africa and Asia, but since 2007, outbreaks have been recorded on several Pacific islands. In 2015, the Zika virus reached the Americas, and within six months over 1.5 million cases had been reported in Brazil alone.

There is an urgent need to understand how the Zika virus moves within a population in order to help policymakers, and public health professionals, plan treatment and control of outbreaks of the disease. Researchers often use predictive models to estimate how a disease will spread. A parameter commonly calculated by these models is the “basic reproductive number”, or R₀, which represents the average number of additional cases of the disease caused by one infected individual.

Using models that incorporated data from Zika virus outbreaks that occurred on several Pacific islands, Champagne et al. have produced estimates of R₀ that range from 1.5-4.1.

The R₀ values are greater than one, indicating that infection will spread within a population, but in the same range as those obtained for dengue fever, another closely related mosquito-borne disease. This suggests that by taking appropriate measures, the spread of Zika and dengue can be controlled to similar extents.

A closer look at the relationship between the population size and the predicted R₀ value for each Pacific island revealed an unexpected inverse relationship: the smaller the population, the larger the value of R₀. Since other regional factors may also explain these large differences between settings, further work is needed to disentangle context-specific from disease-specific factors. In this respect, data about seroprevalence (the number of people whose blood shows evidence of a past infection) in different populations is crucial for precisely analyzing the spread of Zika virus.

DOI:http://dx.doi.org/10.7554/eLife.19874.002

Endoscopic septoplasty: Learning curve

AIMS

The aim of the current study was to report the learning curve for endoscopic septoplasty for a senior surgeon already trained in endonasal sinus surgery.

MATERIAL AND METHODS

From November 2011 to September 2012, 100 patients were prospectively included and grouped in 5 consecutive groups of 20 by date of surgery. The primary endpoint was operative time. Intra- and postoperative complications and functional assessment were also analyzed.

RESULTS

Operative time decreased with the surgeon's experience and became stable after 60 procedures. Operative time saving was about 10min per 20 procedures. Mean operative time was stable between groups 4 (21.1±9.6min) and 5 (19.2±8.2min). There was a 2% rate of conversion to conventional surgery for technical problems. The number of procedures free of accidental mucosal lesion increased and became stable after 40 procedures. There was a 4% rate of residual postoperative perforation. Nasal Obstruction and Septoplasty Effectiveness (NOSE) score improved postoperatively in each group (P<0.05).

CONCLUSION

After 60 endoscopic septoplasty procedures, a senior surgeon masters the surgical technique with satisfactory operative times, and a decreasing rate of intra- and postoperative complications.

Endoscopic vs. conventional septoplasty: A review of the literature

The aim of this review of literature was to compare conventional and endoscopic septoplasty in terms of operating time, functional efficacy and perioperative morbidity. A systematic review of the scientific literature was performed on the PubMed database, Google and Google Scholar, searching for randomized prospective trials comparing endoscopic and conventional septoplasty. The primary endpoint was operating time, and the secondary endpoints were intra- and postoperative complications, postoperative pain, hospital stay and functional result. Twenty-nine articles published between 1991 and 2012 compared conventional and endoscopic septoplasty, five of which were prospective randomized trials. Operating time was shorter with endoscopic surgery (P<0.001), with less mucosal damage (P<0.01); there was less synechia (P<0.01) and residual deformity (P<0.05); and postoperative pain was milder. Endoscopic septoplasty thus shortened surgery time and reduced perioperative complications, but the functional result was the same as with conventional septoplasty.

Endoscopic septoplasty: Tips and pearls

This article is designed to provide a step-by-step description of our endoscopic septoplasty technique and discuss its difficulties and technical tips. Endoscopic septoplasty comprises 10 steps: diagnostic endoscopy, subperichondral infiltration, left mucosal incision, dissection of the left subperichondral flap, cartilage incision (0.5 centimetre posterior to the mucosal incision), dissection of the right subperichondral flap, anterior cartilage resection, perpendicular plate dissection, dissection and resection of the maxillary crest, endoscopic revision, mucosal suture and Silastic stents. A satisfactory postoperative result was observed at 3 months in 97% of cases in this series. The main contraindication to endoscopic septoplasty is anterior columellar deviation of the nasal septum requiring a conventional procedure.

[Potential indications for helical tomotherapy in breast cancers]

PURPOSE

To evaluate the dosimetric gain obtained in either the planning target volume or organs at risk coverage by the use of intensity-modulated radiation therapy in some particular postoperative breast cancers.

PATIENTS AND METHOD

Prospective dosimetric comparison between monoisocentric conformal radiotherapy and intensity-modulated radiation therapy in nine patient files.

RESULTS

Using intensity-modulated radiation therapy was shown to improve in each case, at least one conformity, homogeneity, and coverage index either for planning target volumes or for organs at risk. Intensity-modulated radiation therapy was therefore always chosen rather than conformal monoisocentric radiotherapy.

CONCLUSIONS

Indications to retain intensity-modulated radiation therapy would consist of bilateral lesions, pectus excavatum, past thoracic irradiation (Hodgkin's disease) and complex volumes in obese or overweight patients.

Measuring food intake with digital photography

The digital photography of foods method accurately estimates the food intake of adults and children in cafeterias. When using this method, images of food selection and leftovers are quickly captured in the cafeteria. These images are later compared with images of 'standard' portions of food using computer software. The amount of food selected and discarded is estimated based upon this comparison, and the application automatically calculates energy and nutrient intake. In the present review, we describe this method, as well as a related method called the Remote Food Photography Method (RFPM), which relies on smartphones to estimate food intake in near real-time in free-living conditions. When using the RFPM, participants capture images of food selection and leftovers using a smartphone and these images are wirelessly transmitted in near real-time to a server for analysis. Because data are transferred and analysed in near real-time, the RFPM provides a platform for participants to quickly receive feedback about their food intake behaviour and to receive dietary recommendations for achieving weight loss and health promotion goals. The reliability and validity of measuring food intake with the RFPM in adults and children is also reviewed. In sum, the body of research reviewed demonstrates that digital imaging accurately estimates food intake in many environments and it has many advantages over other methods, including reduced participant burden, elimination of the need for participants to estimate portion size, and the incorporation of computer automation to improve the accuracy, efficiency and cost-effectiveness of the method.

Fish oil metabolites: translating promising findings from bench to bedside to reduce cardiovascular disease

Cardiovascular disease is an inflammatory process and the leading cause of death in the United States. Novel omega-3 derived potent lipid mediators, termed resolvins and protectins, have been identified as major pathophysiologic players in the resolution phase of the inflammatory response. Potent lipid mediators offer tremendous metabolic and pathophysiologic insights in regard to the risk and treatment of cardiovascular disease. In this review, resolvins and protectins are described and analyzed as accelerators of discovery via their potential role as biomarkers for research and clinical decision making in cardiovascular disease. Specific barriers relating to biomarker validation, laboratory methods, and improvement of risk models are introduced and discussed. Potential therapeutic impacts in cardiovascular disease are also mentioned with special consideration for cost-saving implications with respect to dietary fish oil as an alternative to resolvin and protectin treatment. Given the high tolerability of fish oil supplements and previously described benefits of omega-3 fatty acid intake in cardiovascular disease, we conclude that resolvins and protectins are set to soon take center stage as future biomarkers and well-tolerated therapies for cardiovascular disease.

First direct mass measurement of the two-neutron halo nucleus 6He and improved mass for the four-neutron halo 8He

The first direct mass measurement of {6}He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of {8}He was determined with improved precision over our previous measurement. The obtained masses are m({6}He)=6.018 885 883(57)  u and m({8}He)=8.033 934 44(11)  u. The {6}He value shows a deviation from the literature of 4σ. With these new mass values and the previously measured atomic isotope shifts we obtain charge radii of 2.060(8) and 1.959(16) fm for {6}He and {8}He, respectively. We present a detailed comparison to nuclear theory for {6}He, including new hyperspherical harmonics results. A correlation plot of the point-proton radius with the two-neutron separation energy demonstrates clearly the importance of three-nucleon forces.

Gender differences in systemic inflammation and atheroma formation following Porphyromonas gingivalis infection in heterozygous apolipoprotein E-deficient mice

BACKGROUND AND OBJECTIVE

Men are at higher risk for periodontal and cardiovascular diseases compared with women, although they have lower serum levels of risk markers, including lipids and acute phase proteins. In this study, we investigated whether infection with a major periodontal pathogen, Porphyromonas gingivalis, affected the inflammatory and atherosclerotic response of male and female mice differently.

MATERIAL AND METHODS

Forty-eight heterozygous apolipoprotein E-deficient mice (24 males and 24 females), maintained on normal diet, were infected twice by intrasubcutaneous chamber injections of P. gingivalis or vehicle at weeks 11 and 14 of age. Serum samples were collected before the first infection and bi-weekly thereafter, to quantify levels of high-density lipoprotein (HDL) cholesterol and the murine acute phase protein, serum amyloid A (SAA). Mice were killed at week 17 to evaluate aortic atheroma lesion score.

RESULTS

Males had significantly higher baseline HDL cholesterol levels (p < 0.01, factorial ANOVA). Following P. gingivalis infection, HDL cholesterol levels decreased over time in infected males only [p < 0.05, generalized estimating equation (GEE)], whereas SAA levels increased and remained elevated over time in both male and female infected mice (p < 0.01, GEE). Lesion scores were significantly higher in infected mice (3-fold, p < 0.01, factorial ANOVA), and lesion scores of all mice were positively correlated with SAA levels at the time of killing (Spearman correlation coefficient = 0.40, p < 0.01).

CONCLUSION

In these young mice, P. gingivalis infection induced sex-specific changes in serum lipids but no gender differences in acute phase proteins and atheroma lesion score.

The relationship between dietary protein intake and blood pressure: results from the PREMIER study

Observational and clinical studies suggest that high protein intake, particularly protein from plant sources, might reduce blood pressure (BP). To examine the association of dietary protein with BP, we analysed data from PREMIER, an 18-month clinical trial (n=810) that examined the effects of two multi-component lifestyle modifications on BP. We examined the association of protein intake with BP, and in particular the independent relationship of plant and animal protein with BP. Multivariable linear regression analyses were performed with both cross-sectional and longitudinal data. Dietary plant protein was inversely associated with both systolic and diastolic BP in cross-sectional analyses at the 6-month follow-up (P=0.0045 and 0.0096, respectively). Fruit and vegetable intake was also inversely associated with both systolic and diastolic BP cross-sectionally at 6 months (P=0.0003 and 0.0157, respectively). In longitudinal analyses, a high intake of plant protein at 6 months was marginally associated with a reduction of both systolic and diastolic BP from baseline to 6 months only (P=0.0797 and 0.0866, respectively), independent of change in body weight and waist circumference. Furthermore, increased intake of plant protein, and fruits and vegetables was significantly associated with a lower risk of hypertension at 6 but not at 18 months. Results of this study indicate that plant protein had a beneficial effect on BP and was associated with a lower risk of hypertension at 6 months. Our data, in conjunction with other research, suggest that an increased intake of plant protein may be useful as a means to prevent and treat hypertension.

Mechanical loading and ?12prostaglandin J2induce bone morphogenetic protein-2, peroxisome proliferator-activated receptor ?-1, and bone nodule formation in an osteoblastic cell line

BACKGROUND AND OBJECTIVE

We have previously reported that mechanical strain applied at a 1% level to an osteoblastic cell line induces the transcription of prostaglandin D2 synthase and increases the levels of prostaglandin D2 and its Delta12prostaglandin J2 metabolite. Mechanical strain also induces the expression of peroxisome proliferator-activated receptor gamma-1 and bone nodule formation. We hypothesized that mechanical load induces bone formation via Delta12prostaglandin J2-dependent synthesis of bone morphogenetic proteins. Our goal was to investigate the molecular events involved in osteogenesis induced by mechanical loading and Delta12prostaglandin J2, namely the induction of bone morphogenetic proteins and peroxisome proliferator-activated receptor gamma-1, a nuclear receptor for Delta12prostaglandin J2.

MATERIAL AND METHODS

Osteoblast monolayers were stretched for 1 h with a 1-h resting period and stretched for another hour at 1 Hz with 1% elongation. Cells were collected 0, 1, 6 and 16 h after stretching. Cyclooxygenase inhibitors and Delta12prostaglandin J2 were added in some experiments. Relative quantitative reverse transcriptase-polymerase chain reaction was used to examine whether the mRNA of bone morphogenetic protein-2, -4, -6, -7 and peroxisome proliferator-activated receptor gamma-1 was induced. Immunohistochemistry was used to evaluate bone morphogenetic protein expression in cells.

RESULTS

Mechanical strain significantly increased the mRNA expression of bone morphogenetic protein-2, -6, -7 and of peroxisome proliferator-activated receptor gamma-1, but not of bone morphogenetic protein-4. In stretched cells, bone morphogenetic protein-2 and peroxisome proliferator-activated receptor gamma-1 expression was blocked by cyclooxygenase inhibitors, but restored by exogenous Delta12prostaglandin J2. Delta12Prostaglandin J2 significantly enhanced bone nodule formation and bone morphogenetic protein-2 expression when added alone to resting osteoblasts.

CONCLUSION

These results suggest that the osteoblastic biomechanical pathways that trigger bone formation involve cyclooxygenase and prostaglandin D2 synthase activation, induction of Delta12prostaglandin J2 and its nuclear receptor, peroxisome proliferator-activated receptor gamma-1, and increased expression of bone morphogenetic protein-2. These data suggest that the Delta12prostaglandin J2/peroxisome proliferator-activated receptor gamma-1/bone morphogenetic protein-2 pathway plays an important role in osteogenesis.

Growth of probiotic bacteria and bifidobacteria in a soy yogurt formulation

Soy beverage and cows' milk yogurts were produced with Steptococcus thermophilus (ATCC 4356) and Lactobacillus delbrueckii subsp. bulgaricus (IM 025). The drop in pH during fermentation was faster in the soy beverage than in cows' milk, but the final pH values were similar. Yogurts were prepared with a yogurt starter in conjunction with either the probiotic bacteria Lactobacillus johnsonii NCC533 (La-1), Lactobacillus rhamnosus ATCC 53103 (GG) or human derived bifidobacteria. The presence of the probiotic bacteria did not affect the growth of the yogurt strains. Approximately 2 log increases in both L. rhamnosus GG and L. johnsonii La-1 were observed when each was added with the yogurt strains in both cows' milk and the soy beverage. Two of the five bifidobacteria strains grew well in the cows' milk and soy beverage during fermentation with the yogurt bacteria. High pressure liquid chromatography (HPLC) analyses showed that the probiotic bacteria and the bifidobacteria were using different sugars to support their growth, depending on whether the bacteria were growing in cows' milk or soy beverage.

[Intestinal helminthiasis in school children in Haiti in 2002]

A survey on intestinal helminths in school children was conducted in Haiti in 2002. This first nationwide study involving the entire country was stratified by department according to urban and rural zones using the cluster method. Focusing on elementary school children (n=5792; age range 3 to 20 years), it involved 26 urban and 49 rural schools randomly selected. Stools were preserved in formalin and examined by the Ritchie technique. Thirty-four per cent of stools (1981/5792) tested positive for intestinal helminths with the following parasites identified: Ascaris lumbricoides (27.3%), Trichuris trichiura (7.3%), Necator americanus (3.8%), Hymenolepsis nana (2%), Taenia sp. (0.3%) and Strongyloides stercoralis (0.2%). The helminth prevalence was higher in rural (38.4%) compared to urban areas (30%). There was no significant difference in prevalence by sex and age. The importance of geohelminths changed from one department to another with the highest prevalence found in the Southern department of Grande Anse (73.7%) and the lowest prevalence in the Center department (20.6%). Five out of the country's nine departments had a similar prevalence varying from 25.5% to 28.2%. Intestinal helminthic polyparasitism was observed in a percentage of infested school children comprise between 3.4% and 28.6% according in relation to the geographical area. A program to fight against geohelminths in school children should be initiated as a public health priority. Albendazole is the drug of choice. Frequency of drug distribution should be based on the prevalence of geohelminths in each department.

Is routine amniocentesis for advanced maternal age still indicated?

OBJECTIVE

To evaluate a policy of selective rather than routine use of amniocentesis for advanced maternal age.

METHOD

A consecutive series of 359 pregnant women aged 38-47 underwent nuchal translucency measurement (NTM) at 10-14 weeks, maternal serum screening (MSS) by alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) at 15-17 weeks, and second trimester ultrasound at 21-23 weeks. Women with NTM <3 mm, MSS-derived risk <1/250, and a normal second trimester sonography were considered at low risk and were suggested not to have an amniocentesis.

RESULTS

Either the NTM or MSS test was positive in 130 women; 105 (81%) of them elected to have an amniocentesis, versus 122 (53%) of 229 in whom both tests were negative (p < 0.001). Nineteen (5%) of 359 patients had NTM > or =3 mm; all 7 cases of Down's syndrome were in this group; 122 (34%) of 359 patients had a MSS-derived risk > or =1/250; 6 of the 7 cases of Down's syndrome were in this group: Ten patients had an abnormal second trimester ultrasound, 1 of which had trisomy 18. Of the 219 patients with MSS-derived risk <1/250, a NTM <3 mm, and a normal second trimester ultrasound, none had a baby with a chromosomal abnormality (95% confidence interval: 0-1.4%).

CONCLUSION

Amniocentesis may be offered on a selective rather than routine basis in women over 38, based upon the results of noninvasive screening tests.

[Diagnosis of trisomy 21: nuchal translucency and/or serum markers?]

OBJECTIVES

To compare alternative methods of antenatal screening for Down's syndrome (nuchal translucency measurement and second trimester maternal serum screening) in a low-risk population and to evaluate the consequences of a sequential estimation of risk.

METHODS

In a consecutive series of 4308 women aged less than 38 with a singleton pregnancy, we examined the detection rate of nuchal translucency (NT) measurement at 10-14 weeks and maternal serum screening (MSS) by human chorionic gonadotropin and alpha-feto-protein at 14-18 weeks. Women with a NT measurement = 3 mm and women with a MSS derived risk = 1/250 were recommended to have an amniocentesis. A second trimester detailed ultrasound scan was also performed in all women. The outcome of all pregnancies was entered in a computerized database and the detection rate and false-positive rate of different screening strategies were analysed.

RESULTS

Of the 4308 pregnancies that were followed (mean maternal age 30.1 years), there were 12 cases of Down's syndrome (0.28%), all detected prenatally. Seven of twelve cases had a NT measurement above 3 mm (58%), and 6 out of ten cases with available MSS had a calculated risk = 1/250 (60%). Four of the five cases with NT measurement below 3 mm were detected by subsequent MSS. At a threshold giving 5% of positive tests, the sensitivity of NT screening and MSS were 75% and 60%, respectively.

DISCUSSION AND CONCLUSION

Sequential screening for Down's syndrome by nuchal translucency and second trimester biochemistry is effective and appears to increase the detection rate compared to the use of any single test. However, this strategy is likely to raise the false-positive rate and the interpretation of MSS derived risk should be combined to the first trimester NT measurement.

Perceptions of community nutrition and health needs in the Lower Mississippi Delta: a key informant approach

OBJECTIVE

Key informants' perceptions of nutrition and health needs in their southern rural communities were assessed prior to nutrition intervention planning.

DESIGN

This cross-sectional survey used in-person interviews.

SUBJECTS/SETTINGS

A sample of 490 individuals from 12 professional and lay roles in 8 community sectors in 36 counties in Arkansas, Louisiana, and Mississippi was chosen.

STATISTICAL ANALYSES PERFORMED

Factor analysis was carried out on reported food, nutrition, and health problems and contributing factors. The General Linear Models procedure identified within- and between-subject effects for factors. Tukey's post hoc tests identified differences between sectors and states. Frequencies and weighted rankings were computed for health problems.

RESULTS

Key informants rated individual-level factors (food choices, education, willingness to change, health behavior) as more important than community-level factors (food and health care access, resources) with regard to nutrition and health problems and contributors to problems. The number one health problem was hypertension.

IMPLICATIONS

Key informants are knowledgeable about nutrition and health problems, contributing factors, and available resources. Individual factors were perceived as more important contributors to nutrition and health problems providing valuable information for planning nutrition interventions.