Biogeochemical model of nitrogen cycling in Ahe (French Polynesia), a South Pacific coral atoll with pearl farming.

A biogeochemical model (ECO3M-Atoll) was configured to simulate the lower food web in Ahe Atoll lagoon where phytoplankton is mostly nitrogen limited. Understanding the dynamics of phytoplankton - the main food source for oysters - is crucial for the management and the allocation of new pearl farming sites. After parametrizing the model with in situ observations, we tested different hypotheses about nitrogen cycling (benthic remineralization, atmospheric N fixation, etc.) and compared the results to a large observational dataset. Model results show that simulated (pico- and nano-) phytoplankton biomass and nitrogen concentrations are close to in situ data. The simulated biogeochemical processes (uptake and primary production) are also very similar to the observed values. In the model, primary production ranged from 1.00 to 2.00 mg C m-3 h-1 for pico- and 0.40 to 1.00 mg C m-3 h-1 for nanophytoplankton; mean N uptake was 2.02 µmol N m-3 h-1 for pico- and 1.25 µmol N m-3 h-1 for nanophytoplankton.

Free-living amoebae promote Candida auris survival and proliferation in water.

Candida auris is an emerging species responsible for life-threatening infections. Its ability to be resistant to most systemic antifungal classes and its capacity to persist in a hospital environment have led to health concerns. Currently, data about environmental reservoirs are limited but remain essential in control of C. auris spread. The aim of our study was to explore the interactions between C. auris and two free-living amoeba (FLA) species, Vermamoeba vermiformis and Acanthamoeba castellanii, potentially found in the same water environment. Candida auris was incubated with FLA trophozoites or their culture supernatants. The number of FLA and yeasts was determined at different times and transmission electron microscopy (TEM) was performed. Supernatants of FLAs promoted yeast survival and proliferation. Internalization of viable C. auris within both FLA species was also evidenced by TEM. A water environmental reservoir of C. auris can therefore be considered through FLAs and contamination of the hospital water networks would consequently be possible.

Jean Rodier: History of Manganism in Morocco.

Jean Rodier (1920-2003), distinguished researcher and scientist, directed the Toxicology Department of Hygiene Institute of Rabat under the French Protectorate. From 1946, he developed numerous lines of research in occupational health, in particular on Manganism, a neurological disorder that impacted miners in his home country of Morocco. His many papers on Manganism, only one of which was published in English, describe field and laboratory research studies that focused its prevention and management.

In vitro activity of isavuconazole against three species of Acanthamoeba.

Acanthamoeba keratitis due to a genus of free-living amoebae is a severe corneal infection. Treatment of this disease is based on the combined use of antiseptics and other drugs, including azoles. We tested isavuconazole, the latest marketed azole, in vitro, against A. castellanii, A. lenticulata and A. hatchetti. Our results show that isavuconazole presents slight amoebistatic activity against A. castellanii trophozoites but no cysticidal activity. Isavuconazole could be used only in association for management of AK due to A. castellanii.

Unraveling the intrafamilial correlations and heritability of tumor types in MEN1: a Groupe d'étude des Tumeurs Endocrines study.

BACKGROUND: MEN1, which is secondary to the mutation of the MEN1 gene, is a rare autosomal-dominant disease that predisposes mutation carriers to endocrine tumors. Most studies demonstrated the absence of direct genotype-phenotype correlations. The existence of a higher risk of death in the Groupe d'étude des Tumeurs Endocrines-cohort associated with a mutation in the JunD interacting domain suggests heterogeneity across families in disease expressivity. This study aims to assess the existence of modifying genetic factors by estimating the intrafamilial correlations and heritability of the six main tumor types in MEN1. METHODS: The study included 797 patients from 265 kindred and studied seven phenotypic criteria: parathyroid and pancreatic neuroendocrine tumors (NETs) and pituitary, adrenal, bronchial, and thymic (thNET) tumors and the presence of metastasis. Intrafamilial correlations and heritability estimates were calculated from family tree data using specific validated statistical analysis software. RESULTS: Intrafamilial correlations were significant and decreased along parental degrees distance for pituitary, adrenal and thNETs. The heritability of these three tumor types was consistently strong and significant with 64% (s.e.m.=0.13; P<0.001) for pituitary tumor, 65% (s.e.m.=0.21; P<0.001) for adrenal tumors, and 97% (s.e.m.=0.41; P=0.006) for thNETs. CONCLUSION: The present study shows the existence of modifying genetic factors for thymus, adrenal, and pituitary MEN1 tumor types. The identification of at-risk subgroups of individuals within cohorts is the first step toward personalization of care. Next generation sequencing on this subset of tumors will help identify the molecular basis of MEN1 variable genetic expressivity.

Free-living amoebae: what part do they play in healthcare-associated infections?

Free-living amoebae (FLA) are ubiquitous protozoa that do not require a host organism for survival. They are found in natural environments such as water or soil, and man-made environments including tap water or swimming pools, where they may interact with other micro-organisms, including bacteria, fungi and viruses. FLA can harbour micro-organisms including those found in hospital water systems, offering them protection against hostile conditions, providing a vehicle of dissemination, and enabling them to prepare for subsequent survival in macrophages. The interaction between Legionella pneumophila and FLA has been studied extensively; subsequent investigations have shown that FLA may serve as a reservoir for other bacteria including mycobacteria, Pseudomonas aeruginosa, Acinetobacter baumannii, or even fungi and viruses. Amoebae found in hospital water systems can serve as a reservoir of potential pathogens and thus be indirectly related to healthcare-associated infections.

[Detection of Aspergillus antigen galactomannan using ELISA method: validation of the performances of the method for accreditation]. / Validation d'une méthode Elisa pour la recherche de l'antigène aspergillaire galactomannane en vue de l'accréditation.

Diagnosis of invasive aspergillosis for patients with high risk of infection is based on the monitoring of Aspergillus antigenemia assessed by the detection of galactomannan in serum by a sandwich-type ELISA (Biorad(®)). The validation of the method was displayed according to the guide COFRAC SH GTA 04. The internal quality control system settled, involves two quality control samples made of pools of sera (negative and positive). The repeatability of the measurements, as estimated by the coefficients of variation (CV), obtained by two different technicians was found from 9 to 13.7% for the positive control. The CV of the negative control, for which the provider indicates it is not useful in the analytical process, was found from 7.1 to 30%. In our experience it could be an indicator of environmental contamination. The evaluation of the intermediary fidelity was 15.7% for the positive control and 22.5% for the negative one. In the lack of reference material (International Standard) and recommendation from scientific societies, performances obtained will be discussed according to the results reported in the technical form of the supplier and those obtained by 39 laboratories participating in the only available external quality assessment program organized in France by ProBioQual(®) where the CV of reproducibility are 44.7% of unit (mean index 0.131) for the negative control and 18% (mean index 1.089) for the positive one in 2011.

Ipsilateral versus contralateral spontaneous post-stroke neuroplastic changes: involvement of BDNF?

Stroke is a leading cause of death and disability in industrialized countries. Although surviving patients exhibit a certain degree of restoration of function attributable to brain plasticity, the majority of stroke survivors has to struggle with persisting deficits. In order to potentiate post-stroke recovery, several rehabilitation therapies have been undertaken and many experimental studies have reported that brain-derived neurotrophic factor (BDNF) is central to many facets of neuroplastic processes. However, although BDNF role in brain plasticity is well characterized through strategies that manipulate its content, the involvement of this neurotrophin in spontaneous post-stroke recovery remains to be clarified. Besides, while the neuroplastic role of BDNF is restricted to its mature form, most studies investigating the proper effect of ischemia on post-stroke BDNF metabolism focused on mRNA or total protein expressions. In addition, these studies are mainly performed in brain regions collected either at or around the lesion site. Therefore, the objective of the present study was to investigate in both hemispheres, the long-term expression (up to one month) of both pro- and mature BDNF forms in rats subjected to photothrombotic ischemia. These assessments were performed in the cortex and in the hippocampus, two regions known to subserve functional recovery after stroke and were coupled to the study of synaptophysin expression, a marker of synaptogenesis. Our study reports that stroke induces an early and transient increase (4h) in mature BDNF expression in the cortex of both hemispheres that was associated with a delayed rise (30d) in synaptophysin levels ipsilateraly. In both hippocampal territories, the pattern of mature BDNF expression shows a more delayed increase (from 8 to 30d), which coincides with the evolution of synaptophysin expression. Interestingly, in these hippocampal territories, pro-BDNF levels evolve differently suggesting a differential gene regulation between the two hemispheres. While highlighting the complexity of changes in BDNF metabolism after stroke, our data suggest that BDNF involvement in spontaneous post-stroke plasticity is region-dependent.

Ultrasound screening strategies for the diagnosis of congenital anomalies of the kidney and urinary tract.

PURPOSE: Congenital anomalies of the kidneys and urinary tract (CAKUT) are among the most common anomalies in newborn infants, and may cause chronic renal disease in newborns. We investigated the sensitivity and specificity of different ultrasound-based screening strategies for CAKUT. MATERIALS AND METHODS: Newborns (n = 4331) were analyzed for CAKUT in at least one ultrasound examination as a part of the Survey of Neonates in Pomerania (SNiP), a 7-year population-based study on neonates in Western Pomerania (Germany). Intrauterine ultrasound examinations were compared with early postnatal ultrasound findings (from days 3 - 7 of life) and pathological findings within the first 6 months of postnatal life. RESULTS: Cases of CAKUT were detected in 309 (3.7 %) kidneys in one ultrasound examination at the following points of time at least: (i) prenatally in 56 newborns (18.2 %), (ii) 3 - 7 days postnatally in 201 newborns (65.2 %) and (iii) in 52 newborns (17 %) during the 6-month follow-up. The prevalence was significantly higher in male infants, and hydronephrosis was found to be the most frequent obstructive nephropathy (83.3 %). Significant co-morbidity was observed with CNS malformations. The diagnostic sensitivity was significantly higher in postnatal ultrasound screening (79.6 vs. 18.2 % prenatally), while the specificity was above 99 % at all time points. CONCLUSION: This study demonstrates a high prevalence of CAKUT and demonstrates the importance of combined prenatal and postnatal ultrasound examinations for early CAKUT diagnosis.

Risk factors and healing impact of multidrug-resistant bacteria in diabetic foot ulcers.

AIM: To determine the risk factors for acquiring multidrug-resistant organisms (MDRO) and their impact on outcome in infected diabetic foot ulcers. METHODS: Patients hospitalized in our diabetic foot unit for an episode of infected foot ulcer were prospectively included. Diagnosis of infection was based on clinical findings using the International Working Group on the Diabetic Foot-Infectious Diseases Society of America (IWGDF-ISDA) system, and wound specimens were obtained for bacterial cultures. Each patient was followed-up for 1 year. Univariate analysis was performed to compare infected ulcers according to the presence or absence of MDRO; logistic regression was used to identify explanatory variables for MDRO presence. Factors related to healing time were evaluated by univariate and multivariate survival analyses. RESULTS: MDRO were isolated in 45 (23.9%) of the 188 patients studied. Deep and recurrent ulcer, previous hospitalization, HbA(1c) level, nephropathy and retinopathy were significantly associated with MDRO-infected ulceration. By multivariate analysis, previous hospitalization (OR=99.6, 95% CI=[19.9-499.0]) and proliferative retinopathy (OR=7.4, 95% CI=[1.6-33.7]) significantly increased the risk of MDRO infection. Superficial ulcers were associated with a significant decrease in healing time, whereas neuroischaemic ulcer, proliferative retinopathy and high HbA(1c) level were associated with an increased healing time. In the multivariate analysis, presence of MDRO had no significant influence on healing time. CONCLUSION: MDRO are pathogens frequently isolated from diabetic foot infection in our foot clinic. Nevertheless, their presence appears to have no significant impact on healing time if early aggressive treatment, as in the present study, is given, including empirical broad-spectrum antibiotic treatment, later adjusted according to microbiological findings.

Serum procalcitonin and C-reactive protein concentrations to distinguish mildly infected from non-infected diabetic foot ulcers: a pilot study.

AIMS/HYPOTHESIS: Infection of diabetic foot ulcers is common; at early stages it is difficult to differentiate between non-infected ulcers (or those colonised with normal flora) and ulcers infected with virulent bacteria that lead to deterioration. This pilot study aimed to assess the diagnostic accuracy of inflammatory markers as an aid to making this distinction. METHODS: We included 93 diabetic patients who had an episode of foot ulcer and had not received antibiotics during the 6 months preceding the study. Ulcers were classified as infected or uninfected, according to the Infectious Diseases Society of America-International Working Group on the Diabetic Foot classification. Diabetic patients without ulcers (n=102) served as controls. C-reactive protein (CRP), orosomucoid, haptoglobin and procalcitonin were measured together with white blood cell and neutrophil counts. The diagnostic performance of each marker, in combination (using logistic regression) or alone, was assessed. RESULTS: As a single marker, CRP was the most informative for differentiating grade 1 from grade 2 ulcers (sensitivity 0.727, specificity 1.000, positive predictive value 1.000, negative predictive value 0.793) with an optimal cut-off value of 17 mg/l. In contrast, white blood cell and neutrophil counts were not predictive. The most relevant combination derived from the logistic regression was the association of CRP and procalcitonin (AUC 0.947), which resulted in a significantly more effective determination of ulcer grades, as shown by comparing receiver operating characteristic curves. CONCLUSIONS/INTERPRETATION: Measurement of only two inflammatory markers, CRP and procalcitonin, might be of value for distinguishing between infected and non-infected foot ulcers in subgroups of diabetic patients, to help ensure the appropriate allocation of antibiotic treatment. Nevertheless, external validation of the diagnostic value of procalcitonin and CRP in diabetic foot ulcers is needed before routine use can be recommended.

Hartmanella vermiformis can be permissive for Pseudomonas aeruginosa.

AIMS: The amoebae of the genus Hartmanella are frequently recovered from hospital water taps, whereas Pseudomonas aeruginosa is often implicated in nosocomial infections. Previous works suggested that free living amoebae can act as vehicles of bacterial transmission. The present work investigates the relationships between a strain of Hartmanella vermiformis and three strains of P. aeruginosa: a reference strain, a strain from a patient and an environmental strain. METHODS AND RESULTS: In a saline medium, H. vermiformis is not able to favour for the development of P. aeruginosa. In a rich co-cultivation medium, only the environmental strain has shown a growth. CONCLUSIONS: We showed that P. aeruginosa is not a good nutrient source for H. vermiformis. SIGNIFICANCE AND IMPACT OF THE STUDY: Nevertheless, in particular conditions and with particular strains, the presence of H. vermiformis could represent a possibility of growth for P. aeruginosa.

The Internet and the diabetic foot: quality of online information in French language.

UNLABELLED: The Internet has become a major source of health information for consumers. Nevertheless the quality of medical information varies widely and is generally poor. AIM: This study aimed to evaluate the quality of information delivered on French-speaking Internet about the diabetic foot. METHODS: Websites were selected using three popular search engines and introducing "foot+diabetes" and "foot+diabetic" as keywords. Two diabetologists independently evaluated the quality of information using a specially created scoring grid (range 0-52) based on acknowledged and published criteria with items relevant to general characteristics of the site and to information content. One hundred and twenty websites were selected but only 27 were included for analysis. RESULTS: Agreement between the two raters was close for global score and site content but lower for site characteristics. Averaged global score ranged from 8 to 44. Only five sites were assessed as very advisable with a score higher than 39; in contrast 18 sites were judged as not advisable at all (score lower than 26). CONCLUSION: This study, the first to be devoted to information about the diabetic foot on the Internet, clearly shows the variability and the general poor quality of information delivered by the great majority of French-speaking websites. Regulation organisms are urgently needed for checking and labelling public oriented health information in order to make the Internet a performing tool for patient information.

Paranasal sinus fungus ball: epidemiology, clinical features and diagnosis. A retrospective analysis of 173 cases from a single medical center in France, 1989-2002.

Over the last decade, we have observed a high frequency of Aspergillus rhinosinusitis in french medical centers. The epidemiological data, clinical presentations, radiology, mycology and histology results of 173 consecutive patients with paranasal sinus fungus balls who were admitted from 1989 to 2002 have been reviewed. The most common symptoms included purulent nasal discharges and nasal obstructions, with the maxillary sinus being the most common site of infection (152 cases, 87.8%). Computed tomography scans (CT scan) were performed in 92% (159/173) of the cases and heterogeneous opacities were observed in 132 patients (83%). Histology examinations were performed in all cases and proved positive in 162 patients. Fungi were recovered, mainly Aspergillus fumigatus, from samples of 50 patients, while specimens from the remaining 123 patients were negative. Since no specific clinical sign could be found, a diagnosis of fungus ball is frequently made after a long term symptomatic period. CT scan findings of metallic or calcified densities within an opacified sinus cavity are highly suggestive of a fungus ball, but mycological and histological studies are essential to confirm the diagnosis. Treatment consisted of functional endonasal sinus surgery and was successful in 172 out of 173 cases.

Insulin initiation in type 2 diabetic patients admitted in hospital in France and follow-up at 1 year.

OBJECTIVES AND METHODS: The IDAHO 2 epidemiological survey was conducted in departments of diabetology in insulin-naïve type 2 diabetics for whom insulin was initiated. The objective was to assess the patients' profile, the treatments proposed during hospital stay and after one year. RESULTS: 797 patients were analysed. Their characteristics were: age 64+/-12 years, 49% males, weight: 78+/-17 kg, BMI: 29+/-6 kg/m2, diabetes duration 11 years, prevalence of complications: 68%, fasting blood glucose 13+/-6 mmol/l, HbA1c: 10+/-2.2%; treatment prior to insulin comprised: at least 2 OHA: 71% of cases, one: 21%, no OAD: 8%. At hospital discharge, 54% of the patients used basal insulin. After 1 year, 670 continued on insulin. The insulin initiation was accompanied by a decrease in the FBG level (baseline: 13+/-6 mmol/l; final: 8.5+/-2.75 mmol/l; P<0.0001) and a HbA1c improvement (baseline: 10+/-2.2%; final: 7.9+/-1.4%; P<0.0001). This was observed du-ring the first 6 months (HbA1c: 7.8%, P<0.0001 versus baseline). 80% of the patients remained on the same insulin regimen after 1 year: 35% had 1 injection/day, 44% had 2, 12% had 3 and 9% had a complex regimen. The weight gain, the final daily dose and hypoglycaemias increased with the number of injections. The mean daily insulin dose was 33 U/day (24 U with 1 injection/day). CONCLUSION: The IDAHO study shows that insulin is effective in type 2 diabetics however, management is inadequate with insulin therapy being initiated too late and at doses which are low after one year.

[Imported malaria: prevention should strengthened]. / Paludisme d'importation: il faut renforcer le message de prévention.

INTRODUCTION: The risk of acquiring malaria infection can largely be prevented by the regular use of chemoprophylactic drugs combined with protective measures against mosquito bites. In a retrospective study we had for aim to evaluate the compliance to malaria chemoprophylaxis in patients presenting with malaria infection. METHODS: We analyzed the compliance to the recommended malaria chemoprophylaxis of French travelers hospitalized in a department of infectious diseases because of malaria infection, between January 1999 and December 2003. RESULTS: Eighty-five patients, with a mean age of 34.1 years (16-65) were treated for malaria infection. Seventy-seven were due to Plasmodium falciparum. The outcome was favorable for all patients, despite four severe accesses. Forty-six patients (54%) did not take any chemoprophylaxis (CP), 19 (22%) had an inadequate CP for the risk, 13 (15%) badly complied with intermittent intake of CP and seven (8%) complied well with the recommended malaria CP. Among the 85 patients, 27 (32%) had come to the travelers' consultation and been given recommendations and a recommended malaria CP prescription before traveling. CONCLUSION: These results confirm that the majority of imported malaria cases is a consequence of bad compliance to CP. Understanding user profiles and factors predicting non-compliance may help us to improve pretravel counseling, thereby reducing the risk for travelers to acquire malaria infection.

An economic evaluation of Losartan therapy in type 2 diabetic patients with nephropathy: an analysis of the RENAAL study adapted to France.

BACKGROUND: The RENAAL study enrolled 1,513 patients with type 2 diabetes mellitus and nephropathy defined by the presence of proteinuria (urinary albumin: creatinine ratio 300 mg/g or proteinuria > 500 mg per day). Compared to placebo, losartan therapy reduced by 16% (p=0.02) the risk of a composite endpoint (doubling of baseline serum creatinine level, end stage renal disease, or death) and by 28% (p=0.002) the risk of progression to end stage renal disease (ESRD). METHODS: The objective of this study was to compare, using French economic data, the additional cost of losartan therapy with the savings in cost generated by a decrease in the number of end stage renal disease days. Prospectively collected health care resource utilization were used (N(losartan)=751, N(placebo)=762). The follow-up period was 4 years. RESULTS: The mean cumulative cost of losartan over 4 years was 1,603 euros per patient. The reduction in the number of ESRD days over 4 years in patients treated with losartan significantly decreased costs associated with ESRD by 7,438 euros per patient (CI 95%: 3,029 euros - 11,847 euros, p=0.001). Compared to the placebo group, the average cost per patient over 4 years in the losartan group was lower by 5,834 euros (CI 95%: 1,407 euros - 10,301 euros, p=0.01). CONCLUSION: In addition to the medical benefit, this analysis demonstrated the economic relevance of treatment with losartan in type 2 diabetic patients with nephropathy.

Effect of matrix metalloprotease inhibitors on the 95 kDa metallopeptidase of Candida albicans.

A 95 kDa metallopeptidase of Candida albicans could be involved in the process of dissemination of the yeast. Matrix metalloproteases (MMPs) are also responsible for collagen breakdown in inflammatory and malignant processes. We tested six compounds on the C. albicans enzyme. Doxycycline, gentamicin, cefalothin, galardin, and elaidic and oleic acids are known for their capacity to inhibit some MMPs. Amongst these agents, only oleic acid was able to markedly inhibit the purified metallopeptidase at very low concentrations. Moreover, this fatty acid inhibited the secretion of the enzyme in the culture medium without altering the yeast viability.

Influence of sub-inhibitory concentrations of conventional antifungals on metabolism of Candida albicans and on its adherence to polystyrene and extracellular matrix proteins.

Five antifungal agents with different mechanisms of action were compared for their ability to affect mitochondrial dehydrogenase activity and adherence capacity of Candida albicans to polystyrene and extracellular matrix proteins. Only amphotericin B inhibited mitochondrial dehydrogenase activity when the culture medium was supplemented with galactose. 5-Fluorocytosine and terbinafine did not affect this activity, whereas itraconazole and fluconazole improved it. Furthermore, in these experimental conditions, the effect of sub-inhibitory concentrations of antifungals on adherence was dependent on the tested antifungal and the adherence surface: amphotericin B inhibited adherence to polystyrene and fibrinogen, but improved adherence to extracellular matrix. For all surfaces tested, when culture medium was supplemented with galactose, fluorocytosine did not affect adherence, and itraconazole, fluconazole and terbinafine inhibited adherence. Our results also confirmed the influence of the carbohydrates: sub-minimum inhibitory concentrations (MIC) of itraconazole increased or did not modify the mitochondrial metabolism of yeasts when the culture medium was supplemented with galactose, but this antifungal always decreased mitochondrial metabolism when the culture medium was supplemented with glucose. These data indicate that antifungals used below their MIC values can have various effects. It is important to distinguish the effects of antifungals on the metabolism of C. albicans from effects on its adherence capacity. The former effects are linked to the viability of the yeast and the latter depends on the colonization of cellular as opposed to inert surfaces.