Impaired reprogramming of the autophagy flux in maturing dendritic cells from crohn disease patients with core autophagy gene-related polymorphisms

Crohn disease (CD) is an inflammatory bowel disease whose pathogenesis involves inappropriate immune responses toward gut microbiota on genetically predisposed backgrounds. Notably, CD is associated with single-nucleotide polymorphisms affecting several genes involved in macroautophagy/autophagy, the catabolic process that ensures the degradation and recycling of cytosolic components and microorganisms. In a clinical translation perspective, monitoring the autophagic activity of CD patients will require some knowledge on the intrinsic functional status of autophagy. Here, we focused on monocyte-derived dendritic cells (DCs) to characterize the intrinsic quantitative features of the autophagy flux. Starting with DCs from healthy donors, we documented a reprogramming of the steady state flux during the transition from the immature to mature status: both the autophagosome pool size and the flux were diminished at the mature stage while the autophagosome turnover remained stable. At the cohort level, DCs from CD patients were comparable to control in term of autophagy flux reprogramming capacity. However, the homozygous presence of ATG16L1 rs2241880 A>G (T300A) and ULK1 rs12303764 (G/T) polymorphisms abolished the capacity of CD patient DCs to reprogram their autophagy flux during maturation. This effect was not seen in the case of CD patients heterozygous for these polymorphisms, revealing a gene dose dependency effect. In contrast, the NOD2 rs2066844 c.2104C>T (R702W) polymorphism did not alter the flux reprogramming capacity of DCs. The data, opening new clinical translation perspectives, indicate that polymorphisms affecting autophagy-related genes can differentially influence the capacity of DCs to reprogram their steady state autophagy flux when exposed to proinflammatory challenges.Abbreviation: BAFA1: bafilomycin A1, CD: Crohn disease; DC: dendritic cells; HD: healthy donor; iDCs: immature DCs; IL: interleukin; J: autophagosome flux; LPS: lipopolysaccharide; MHC: major histocompatibility complex; nA: autophagosome pool size; SNPs: single-nucleotide polymorphisms; PCA: principal component analysis; TLR: toll like receptor; τ: transition time; TNF: tumor necrosis factor.

Relationships of circulating CD4+ T cell subsets and cytokines with the risk of relapse in patients with Crohn’s disease

Background and aims

We aimed to analyze circulating CD4+ T cell subsets and cytokines during the course of Crohn’s disease (CD).

Methods and results

CD4+ T cell subsets, ultrasensitive C-reactive protein (usCRP), and various serum cytokines (IL-6, IL-8, IL-10, IL-13, IL-17A, IL-23, TNFα, IFNγ, and TGFβ) were prospectively monitored every 3 months for 1 year, using multicolor flow cytometry and an ultrasensitive Erenna method in CD patients in remission at inclusion. Relapse occurred in 35 out of the 113 consecutive patients (31%). For patients in remission within 4 months prior to relapse and at the time of relapse, there was no significant difference in Th1, Th17, Treg, and double-positive CD4+ T cell subsets co-expressing either IFNγ and FOXP3, IL-17A and FOXP3, or IFNγ and IL-17A. On the contrary, in patients who remained in remission, the mean frequency and number of double-positive IL-17A+FOXP3+ CD4+ T cells and the level of usCRP were significantly higher (p ≤ 0.01) 1 to 4 months prior to relapse. At the time of relapse, only the IL-6 and usCRP levels were significantly higher (p ≤ 0.001) compared with those patients in remission. On multivariate analysis, a high number of double-positive IL-17A+FOXP3+ CD4+ T cells (≥1.4 cells/mm3) and elevated serum usCRP (≥3.44 mg/L) were two independent factors associated with risk of relapse.

Conclusions

Detection of circulating double-positive FOXP3+IL-17A+ CD4+ T cell subsets supports that T cell plasticity may reflect the inflammatory context of Crohn’s disease. Whether this subset contributes to the pathogenesis of CD relapse needs further studies.

Intestinal Conventional Ultrasonography, Contrast-Enhanced Ultrasonography and Magnetic Resonance Enterography in Assessment of Crohn's Disease Activity: A Comparison with Surgical Histopathology Analysis

BACKGROUND AND AIMS

Contrast-enhanced ultrasonography (CEUS) is a potential interesting method for assessing accurately Crohn's disease (CD) activity. We compared the value of intestinal ultrasonography (US) coupled with contrast agent injection with that of magnetic resonance enterography (MRE) in the assessment of small bowel CD activity using surgical histopathology analysis as reference.

METHODS

Seventeen clinically active CD patients (14 women, mean age 33 years) requiring an ileal or ileocolonic resection were prospectively enrolled. All performed a MRE and a US coupled with contrast agent injection (CEUS) less than 8 weeks prior to surgery. Various imaging qualitative and quantitative parameters were recorded and their respective performance to detect disease activity, disease extension and presence of complications was compared to surgical histopathological analysis.

RESULTS

The median wall thickness measured by US differed significantly between patients with non-severely active CD (n = 5) and those with severely active CD (n = 12) [7.0 mm, IQR (6.5-9.5) vs 10.0 mm, IQR (8.0-12.0), respectively; p = 0.03]. A non-significant trend was found with MRE with a median wall thickness in severe active CD of 10.0 mm, IQR (8.0-13.7) compared with 8.0 mm, IQR (7.5-10.5) in non-severely active CD (p = 0.07). The area under the ROC curve (AUROC) of the wall thickness assessed by US and MRE to identify patients with or without severely active CD on surgical specimens were 0.85, 95% CI (0.64-1.04), p = 0.03 and 0.80, 95% CI (0.56-1.01), p = 0.07, respectively. Among the parameters derived from the time-intensity curve during CEUS, time to peak and rise time were the two most accurate markers [AUROC = 0.88, 95% CI (0.70-1.04), p = 0.02 and 0.86, 95% CI (0.68-1.04), p = 0.03] to detect patients with severely active CD assessed on surgical specimens.

CONCLUSION

The accuracy of intestinal CEUS is close to that of conventional US to detect disease activity. A thickened bowel and shortened time to peak and rise time were the most accurate to identify CD patients with severe histological disease activity.

Oral anticoagulants but not antiplatelet agents increase the risk of delayed bleeding after endoscopic papillectomy: a large study in a tertiary referral center

BACKGROUND

Endoscopic papillectomy (EP) is an effective curative treatment in patients with ampullary adenomas. However, EP is burdened by a not-negligible risk of bleeding. The aim of this study was to determine risk factors for delayed bleeding after EP.

METHODS

A retrospective analysis of a prospectively-collected database was performed, retrieving all EP performed over a 20-year period. Anti-thrombotic treatments were managed according to guidelines. Delayed bleeding was defined as overt gastrointestinal bleeding or drop in haemoglobin level. Multivariate logistic regression was used to identify variables related to delayed bleeding.

RESULTS

Three-hundred-seven patients (48.5% male, median age 68-year-old) entered the study; of them, 51 (16.6%) received anti-thrombotic treatments. Delayed bleeding occurred in 44 (14.3%) patients. No difference was observed in patients receiving antiplatelet agents. Multivariate analysis identified oral anticoagulant agents (odd Ratio 4.37 [2.86-5.95]) and procedural bleeding (OR 2.22 [1.10-4.40]) as independently related to delayed bleeding; in patients with no procedural bleeding, oral anticoagulant agents (OR 5.63 [2.25-9.83]) and ampullary tumor size (OR 1.07 [1.01-1.13]) were independently related to delayed bleeding. Patients on anticoagulant agents presented significantly higher need for blood transfusion (16.7 vs. 1.5%); no difference in intensive care unit admission, surgery or mortality was observed.

CONCLUSIONS

This study demonstrates that patients on oral antiplatelet agents do not present increased risk for post-EP delayed bleeding. EP represents a valid alternative to surgery even in patients on anticoagulant agents, despite significantly increased risk of delayed bleeding. A tailored approach to those cases should be planned.

Serious and atypical presentations of Bartonella henselae infection in kidney transplant recipients

This article describes 5 cases of bartonellosis with fever and atypical clinical presentations in kidney transplant recipients: thrombotic microangiopathies, recurrent hemophagocytosis, and immune reconstitution syndrome after treatment. The diagnosis, the pathological lesions, and treatments are described. Bartonellosis must be researched in solid organ transplant recipients with fever of undetermined origin.

Low Levels of Fecal Calprotectin 3 Months After Surgery Predict Subsequent Endoscopic Postoperative Remission in Crohn's Disease

BACKGROUND/AIMS

In Crohn's disease (CD) few data are available on the usefulness of monitoring fecal calprotectin (FC) in the early postoperative setting. We assessed prospectively the accuracy of FC measured 3 months after surgery to predict the risk of endoscopic postoperative recurrence (POR) within 1 year after resection.

METHODS

In 55 consecutive CD patients who had undergone ileocolonic resection samples were collected 3 months after surgery for measuring serum CRP and FC. Endoscopic POR was assessed by ileocolonoscopy within 6-12 months (median 7 months). Receiver operating characteristic (ROC) curves were generated to assess accuracy of the markers, to determine the best threshold and to calculate sensitivity, specificity, positive and negative predictive values.

RESULTS

In contrast with median CRP levels, median FC concentrations measured 3 months after surgery were significantly higher in patients who later experienced endoscopic POR (Rutgeerts ≥ i2) compared with those who stayed in endoscopic remission within the following 6-12 months (205 μg/g IQR [106-721] vs. 103 μg/g IQR [60-219], p = 0.008). Area under the ROC curve for FC was 0.71. The best cutoff value of FC to identify patients in subsequent endoscopic remission 3 months after surgery was 65 μg/g (96% sensitivity, 31% specificity, 50% positive and 91% negative predictive values). In multivariate analysis, FC < 65 µg/g at 3 months was the only factor associated with subsequent endoscopic remission.

CONCLUSION

FC measured 3 months after surgery below 65 μg/g is an accurate marker to identify CD patients who will later stay in endoscopic remission within 1 year after resection.

Advanced nitrogen removal from anaerobically pre-treated potato wastewater via partial nitritation-anammox in a continuous fed SBR

Partial nitritation-anammox was carried out successfully in a continuous fed Sequencing Batch Reactor (cf-SBR), composed of 3 compartments operated in continuous mode. The reactor was operated with floccular biomass (flocs) and biofilm to remove nitrogen from the anaerobic effluent from the potato industry at different nitrogen loading rates (0.16 g TN L^-1 d^-1 - 0.8 g TN L^-1 d^-1). At the maximum nitrogen loading rate (NLR) evaluated the nitrogen removal and ammonia oxidation achieved were 62% and 74% respectively. During the evaluation of the NLR, it was observed an improvement of the characteristics of the sludge, improving the Sludge Volumetric Index (SVI) from 228 to 63 mL g^-1 MLSS. Moreover, molecular analysis (qPCR) confirmed the presence of anammox bacteria on the flocs and in the biofilm from the cf-SBR. The results showed the capability of the reactor to carry out the partial nitritation-anammox in the same reactor at pilot scale. The cf-SBR was presented as a suitable and feasible technology for advanced nitrogen removal under partial nitritation and anammox conditions.

91 Can propylene glycol modulate insulin and insulin-like growth factor-1 in superovulated dairy heifers?

The aim of this study was to determine the effect of propylene glycol (PPG) on serum concentrations of insulin and insulin-like growth factor (IGF)-1 in superovulated dairy heifers. We hypothesised that administration of PPG would have a positive effect on superovulation results via increased insulin and IGF-1. A total of 20 clinically healthy Holstein heifers with an average age of 12 months were used for this experiment. Superovulation was performed using a standard protocol. Briefly, each heifer received 3mg of oestradiol-17β IM and an intravaginal progesterone-releasing insert (CIDR) containing 1.9g of progesterone at random stages of the oestrous cycle (designated Day 0). From Day 4 to 8, heifers received a total of 200mg of NIH-follicle-stimulating hormone-P1 administered intramuscularly through 9 injections of decreasing doses (from 50 to 10mg) at 12-h intervals. On Day 7, heifers received 2 injections of 500µg of cloprostenol, a PGF2α analogue, at ~6-h intervals, after which intravaginal inserts were removed. Artificial insemination was performed on Day 10, 12h after treatment with 100µg of gonadotropin-releasing hormone IM. Embryos were flushed from the uterus of donor heifers 6 days after AI. The method consisted of simultaneously using 1 catheter per uterine horn. Catheters were maintained in place to perform 2 flushes 1h apart. A total of 1L of flushing medium was used, 700 and 300mL for the first and the second flush, respectively. Embryos were assessed for viability immediately after collection using the IETS classification. Heifers were divided into 2 groups (PPG and control group). From Day 4 to 14 of the superovulation protocol, PPG group received a daily dose of 400mL of a 66.7% propylene glycol solution, whereas the control group received the same amount of water. Two months later, the same experiment was conducted by inverting the groups. At Day 4 and 14, four blood samples were collected to measure insulin and IGF-1 at 25-min intervals. The first sample (0) was taken before heifers received PPG or water. Insulin was analysed using an ELISA kit following manufacturer’s instructions, whereas IGF-1 was determined using a chemiluminescence immunoassay. Embryo associated data were analysed using t-test. Both IGF-1 and insulin data were analysed using a two-way ANOVA, followed by Bonferroni post-hoc test. Treatment with PPG had no effect on the number of transferable embryos (8±5.1v. 7±5.5), degenerated embryos (0.5±0.8v. 1.5±2.4), or unfertilized oocytes (0.3±0.7v. 0.7±1.2) recovered. There was also no effect of PPG on IGF-1 serum concentrations at the beginning (Day 4) or the end (Day 14) of the treatment regimen. However, PPG treatment enhanced (P = 0.02) serum insulin concentrations 50min after administration on Day 4 (10.69 v. 6.88 pmol/L), as well as at 25 (19.58 v. 9.64 pmol/L) and 50min (16.67v. 8.21 pmol/L) on Day 14. It has been suggested that PPG metabolism may stimulate insulin and IGF-1 secretion, which can promote embryo development. However, in the present study, there was no effect of oral doses of PPG on IGF-1. Although higher serum concentrations of insulin were observed after PPG treatment, there was no effect of PPG treatment on the number of transferable embryos recovered following superovulation.

90 Effects of treatment with the nonsteroidal anti-inflammatory drug Anafen prior to embryo recovery and the number of embryo flush procedures performed on prostaglandin levels in uterine fluid and pregnancy rate following embryo transfer

Some studies have shown that performing a second flush during embryo collection can increase the number of embryos recovered. However, this technique results in greater uterine manipulation that may increase PGF2α in the uterine fluid of donor cows and affect pregnancy rate in recipient females. Two experiments were conducted (1) to determine whether PGF2α concentration in uterine fluid was affected by treatment with a non-steroidal anti-inflammatory drug (NSAID) before embryo recovery and (2) to determine whether the percent of recipients becoming pregnant following embryo transfer (P/ET) was affected by flush number. In both experiments, lactating Holstein cows were used as donors (n=18 and 34, respectively) and subjected to a standard superovulation protocol (Baracaldo et al. 2000 Theriogenology 53, 1239-1250, DOI: 10.1016/S0093-691X(00)00268-5). Embryo recovery was performed using 2 catheters that were inserted simultaneously into the uterus, 1 into each horn. During the first flush, a volume of 300mL of flush medium was used in each horn. At the end of the first flush approximately 75mL of fluid was left and, after 1h, a second flush was performed to recover the remaining fluid. Samples were taken from each horn at the first and second flush to determine PGF2α concentration using a bovine PGFM ELISA kit. Data for PGF2α concentrations in uterine fluid were presented as the average of both uterine horns. In Exp. 1, donors were randomly assigned to be treated with or without 1.2g of the NSAID Anafen (ketoprofen) IM 20min before embryo recovery. In Exp. 2, recovered grade-1 embryos from the first and second flush procedures were frozen in ethylene glycol and subsequently transferred to synchronized Holstein heifers (n=106 and 49 for the first and second flushes, respectively). Pregnancy was diagnosed by rectal palpation at Day 60. All data were analysed using t-test. In Exp. 1, Anafen treatment 20min before embryo recovery reduced PGF2α in uterine fluid during the second flush procedure (105.9±11.4v. 43.6±5.7 pg/mL; P&lt;0.001), but not during the first (54.7±7.3v. 44.2±5.6 pg/mL; P=0.34). In Exp. 2, PGF2α in uterine fluid was greater for the second flush as compared to the first flush (95.9±7.4v. 56.3±5.5 pg/mL; P&lt;0.001). A total of 345 viable embryos were recovered from the 34 donors in Exp. 2 (n=276 and 69 for the first and second flushes, respectively). The P/ET at Day 60 was greater (P&lt;0.05) for recipients that received embryos from the first flush as compared to recipients that received embryos from the second flush (64.2v. 49.0%). Taken together, the results of the present study indicate that the second flush procedure results in greater PGF2α levels in uterine fluid and that embryos recovered during the second flush are less likely to establish pregnancy following transfer. Moreover, pretreatment of donors with the NSAID Anafen reduced PGF2α levels in uterine fluid during the second flush. Further research is needed to determine whether treatment of donors with NSAID can improve the P/ET achieved following the transfer of embryos recovered following a second flush procedure.

Radiofrequency ablation of stage IA non-small cell lung cancer in patients ineligible for surgery: results of a prospective multicenter phase II trial

Background

A prospective multicenter phase II trial to evaluate the survival outcomes of percutaneous radiofrequency ablation (RFA) for patients with stage IA non-small cell lung cancer (NSCLC), ineligible for surgery.

Methods

Patients with a biopsy-proven stage IA NSCLC, staging established by a positron emission tomography-computed tomography (PET-CT), were eligible. The primary objective was to evaluate the local control of RFA at 1-year. Secondary objectives were 1- and 3-year overall survival (OS), 3-year local control, lung function (prior to and 3 months after RFA) and quality of life (prior to and 1 month after RFA).

Results

Of the 42 patients (mean age 71.7 y) that were enrolled at six French cancer centers, 32 were eligible and assessable. Twenty-seven patients did not recur at 1 year corresponding to a local control rate of 84.38% (95% CI, [67.21–95.72]). The local control rate at 3 years was 81.25% (95% CI, [54.35–95.95]). The OS rate was 91.67% (95% CI, [77.53–98.25]) at 1 year and 58.33% (95% CI, [40.76–74.49]) at 3 years. The forced expiratory volume was stable in most patients apart from two, in whom we observed a 10% decrease. There was no significant change in the global health status or in the quality of life following RFA.

Conclusion

RFA is an efficient treatment for medically inoperable stage IA NSCLC patients. RFA is well tolerated, does not adversely affect pulmonary function and the 3-year OS rate is comparable to that of stereotactic body radiotherapy, in similar patients.

Trial registration

ClinicalTrials.gov Identifier NCT01841060 registered in November 2008.

MACVIA-LR (Fighting Chronic Diseases for Active and Healthy Ageing in Languedoc-Roussillon): A Success Story of the European Innovation Partnership on Active and Healthy Ageing

The Région Languedoc Roussillon is the umbrella organisation for an interconnected and integrated project on active and healthy ageing (AHA). It covers the 3 pillars of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA): (A) Prevention and health promotion, (B) Care and cure, (C) and (D) Active and independent living of elderly people. All sub-activities (poly-pharmacy, falls prevention initiative, prevention of frailty, chronic respiratory diseases, chronic diseases with multimorbidities, chronic infectious diseases, active and independent living and disability) have been included in MACVIA-LR which has a strong political commitment and involves all stakeholders (public, private, patients, policy makers) including CARSAT-LR and the Eurobiomed cluster. It is a Reference Site of the EIP on AHA. The framework of MACVIA-LR has the vision that the prevention and management of chronic diseases is essential for the promotion of AHA and for the reduction of handicap. The main objectives of MACVIA-LR are: (i) to develop innovative solutions for a network of Living labs in order to reduce avoidable hospitalisations and loss of autonomy while improving quality of life, (ii) to disseminate the innovation. The three years of MACVIA-LR activities are reported in this paper.

[Outpatient management of pulmonary embolism diagnosed in emergency services]

In the emergency department, the management of patients with pulmonary embolism depends on the early mortality risk. Outpatient care is possible in low-risk patients. We present the existing scores and the strategy proposed by the North Alps Emergency Network, which uses the simplified PESI score (Pulmonary Embolism Severity Index) to select those low-risk patients, candidates for early discharge.

[Tracheal adenoid cystic carcinoma treated by complete carinal reconstruction with the help of an ECMO: about a case]

Primitive tumors of the trachea are rare, accounting for 0.1% of the airway tumors. Cystic adenoid carcinoma (or cylindroma) represents the second most frequent type of tracheal cancers. Histologically speaking, this tumor type is divided in three patterns: cribriform, tubular and solid; it presents a slow growth, perineural invasion and potential local recurrence and metastasis. We presented herein the case of a 56-year-old female suffering from a cystic adenoid carcinoma of the low trachea. She has been treated by carinal resection with negative airway margin and complete reconstruction, with the help of an extra corporeal membrane oxygenation (ECMO).

CT evaluation of torsional malalignment after intertrochanteric fracture fixation

INTRODUCTION

Trochanteric fractures are commonly stabilized either by intramedullary nailing or plate and screw fixation after reduction on the orthopaedic surgical table under radiological guidance.

HYPOTHESIS

Closed trochanteric fracture anatomic reduction is difficult in the transversal plane.

OBJECTIVES

The objective of this prospective study was to assess the rotational malalignment induced after reduction and osteosynthesis of trochanteric fractures.

PATIENTS AND METHODS

Prospective study including 40 patients (mean age, 78 years; range, 51-90 years) operated for a trochanteric fracture between January 2007 and September 2008. Fourteen fractures were treated using DHS™ (Synthes™) plate and screw fixation and 26 with intramedullary nailing (trochanteric nail™, Stryker™). All these patients underwent postoperative CT of the pelvis during their hospitalization with measurement of anteversion of the operated and healthy femoral necks at the posterior condyles. The evaluation criterion was whether or not there was malalignment greater than 15° on the operated side compared to the healthy side.

RESULTS

The mean anteversion was 14.2° for the healthy side and 23° for the operated side. The mean rotational malalignment was 15.3°. Forty percent of the rotational malalignments were greater than 15°, with a majority of cases showing excess internal rotation (35%) of the distal fragment.

CONCLUSION AND DISCUSSION

The rate of internal rotational malalignment of the distal fragment greater than 15° was high (40% of this series). This should encourage surgeons to reduce the excess internal rotation that tends to be attributed to the distal fragment during preoperative reduction of these fractures.

LEVEL OF EVIDENCE

Level III. Prospective diagnostic study with no control group.

Predictors of depression in multiple sclerosis patients

Depression is one of the major problems associated with multiple sclerosis (MS). Several physical and psychological factors tend to interact and make it difficult to pinpoint the predictors of the depression. It seemed particularly important to examine how anxiety and illness evolution (characterized by the functional status) influence the appearance of depression symptoms. Thus, the aim of this article was to clarify the relationship between depression and the factors associated with it. One hundred and fifteen participants living at home recruited through various associations and MS clinics answered socio demographic, medical and psychological questions and questionnaires (depression, anxiety, coping, social support, locus of control, alexithymia, self-esteem). Results show that functional status (EDSS), trait anxiety, alexithymia and satisfaction with social support system are the predicting factors of depression. Trait anxiety and functional status are two predictors that independently and simultaneously lead to the appearance of depression symptoms, with trait anxiety playing a predominant role. Alexithymia and social support indirectly influence the appearance of these symptoms.

Characterization of a major colon cancer susceptibility locus (Ccs3) on mouse chromosome 3

Treatment of mice with the carcinogen azoxymethane (AOM) induces a number of lesions in the colon, including hyperplastic lesions, as well adenomas and carcinomas in situ. Inbred strains of mice show different responses to AOM-induced carcinogenesis. A/J mice are highly susceptible and develop a greater number of hyperplastic lesions and tumors (15-70 tumors per mouse) than resistant C57BL/6J mice (0-6 tumors per mouse). Susceptibility to AOM-induced tumors segregates as a co-dominant trait in (A x B6)F1 hybrids. Using a set of 23 AcB and BcA recombinant congenic mouse strains derived from A/J (susceptible) and B6 (resistant) parents, we observed that the number of hyperplastic lesions and tumors induced by AOM was under different genetic controls in AcB/BcA strains. The multiplicity of AOM-induced tumors is controlled by a major locus that we have mapped on the distal portion of chromosome 3, to which we have given the temporary designation colon cancer susceptibility locus 3 (Ccs3). B6 and A/J alleles at Ccs3 are associated with resistance and susceptibility, respectively. Haplotype analysis in key informative AcB/BcA strains restricts the size of the Ccs3 locus to a 14 Mb segment that contains 94 annotated genes. The expression level of all these genes in normal colon has been established by transcript profiling with microarrays, and has led to the identification of a subset of positional candidates that are expressed at high levels in this tissue. The 4q and 1p human chromosomal segments sharing syntenic homology with the mouse Ccs3 segment are known to be associated with inflammatory bowel diseases and colorectal tumors in humans, suggesting that the study of the mouse Ccs3 locus may help further the pathogenesis of these human conditions.

Comparison of epidemiological, clinical, and biological features of invasive aspergillosis in neutropenic and nonneutropenic patients: a 6-year survey

BACKGROUND

Invasive aspergillosis is an opportunistic infection that occurs mainly among patients with prolonged neutropenia. Few data are available on invasive aspergillosis in nonneutropenic patients.

METHODS

The aim of this survey was to compare neutropenic and nonneutropenic patients who had received a diagnosis of invasive aspergillosis at our institution during a 6-year period.

RESULTS

Among the 88 cases of invasive aspergillosis analyzed here, 12 were histologically proven, 52 were probable, and 24 were possible. Forty-seven percent of cases were diagnosed in the intensive care unit, and 40% were diagnosed in hematology units. Neutropenia was a risk factor for 52 patients (59%), most of whom had hematological or solid malignancies. Among the 36 nonneutropenic patients (41%), the main underlying conditions were steroid-treated chronic obstructive pulmonary disease, asthma, rheumatoid arthritis, giant-cell arteritis, and microvascular disorders; 10 patients were recipients of solid-organ transplants, and 1 patient was seropositive for human immunodeficiency virus. The distribution of proven and probable invasive aspergillosis was similar for neutropenic and nonneutropenic patients. The mortality rate was 71.5% overall and was significantly higher among nonneutropenic patients than among neutropenic patients (89% vs. 60%; P<.05). Compared with neutropenic patients, nonneutropenic patients were significantly less likely to have symptoms of invasive aspergillosis and more likely to have frequent intercurrent pneumonia due to another microorganism. The sensitivity of mycological examination of bronchoalveolar lavage fluid specimens was higher for nonneutropenic patients than for neutropenic patients (85% vs. 58%; P<.05), whereas the sensitivity of antigenemia was the same for the 2 populations (65% vs. 64%). Findings on thoracic computed tomographs were similar, except that segmental areas of consolidation occurred more frequently among neutropenic patients.

CONCLUSION

This survey at a whole institution underlines the high number of cases of invasive aspergillosis among nonneutropenic patients, with an overall mortality rate that was significantly higher than that for neutropenic patients.

Comparison between shell morphology and genetic diversity in two sympatric lymnaeid snails, vectors of fasciolosis

Species determination of freshwater snails is particularly important in the case of disease vectors. In central France, for example, it has been shown that Galba truncatula (Müller, 1774) and Omphiscola glabra (Müller, 1774), which can be found in sympatry, are intermediate hosts for fasciolosis. Although these two species are distinguishable based on their shell morphology, some snails present in sympatric zones possess shell characteristics that are common to both species, suggesting possible gene flow. To test this hypothesis, we carried out multilocus enzyme electrophoreses on individuals sampled in one zone of sympatry. Our results clearly show that all snails with shell characteristics common to both species are O. glabra. We also note an absence of hybridization between G. truncatula and O. glabra in the study area. Remarkably, we observe a total monomorphism at the six studied loci among individuals of G. truncatula. Similarly, we find a total lack of heterozygotes in the O. glabra sample (with classic or intermediate shell characteristics). These results suggest a predominance of selfing in the reproductive mode of both species. Our results suggest that conchological characteristics can provide information about the taxonomic position of lymnaeids. However, they are insufficient to confidently differentiate species.

Intérêts et difficultés d’interprétation du coefficient de transfert du CO (TLCO/VA)

INTRODUCTION

Interpreting measurements of carbon monoxide can be problematic.

STATE OF THE ART

The transfer factor (TLCO) is usually calculated by multiplying the decrease in alveolar CO concentration between the beginning and the end of a 10 second breath hold (KCO) by the alveolar volume (VA). Thus a reduced TLCO may occur due to either a low KCO, a reduced VA, or a combination of both.

PERSPECTIVES

A careful examination of KCO and VA will usually suggest a specific explanation for a reduction in TLCO. In restrictive lung diseases from extrapulmonary origin, TLCO is low but TLCO/VA [[/INF 120% of the reference values. In interstitial lung disease, the value of TLCO/VA depends on whether the loss of lung units is diffuse or not, and probably also on the status of the microcirculation. In airflow obstruction, a low VA is caused by uneven distribution of inspired He/CO mixture within the breath-hold time.

CONCLUSIONS

The transfer factor for carbon monoxide is best interpreted in terms of its components, alveolar volume and carbon monoxide transfer coefficient.

Small effective population sizes in a widespread selfing species, Lymnaea truncatula (Gastropoda: Pulmonata)

We present here a spatial and temporal population genetic survey of a common freshwater snail, also a predominantly selfing species, Lymnaea truncatula. The rate of genetic diversity loss was quantified by estimating the effective size (Ne) of the snail populations, using two different methods. A temporal survey allowed estimation of a variance effective size of the populations, and a spatial survey allowed the estimation of an inbreeding effective size, from two-locus identity disequilibria estimates. Both methods were consistent and provided low Ne values. Drift due to (i) high amounts of selfing and (ii) fluctuations in population sizes because of temporary habitats, and also selection coupled to genome-wide linkage disequilibria, could explain such reductions in Ne. The loss of genetic diversity appears to be counterbalanced only very partially by low apparent rates of gene flow.

How shunting inhibition affects the discharge of lumbar motoneurones: a dynamic clamp study in anaesthetized cats

In the present work, dynamic clamp was used to inject a current that mimicked tonic synaptic activity in the soma of cat lumbar motoneurones with a microelectrode. The reversal potential of this current could be set at the resting potential so as to prevent membrane depolarization or hyperpolarization. The only effect of the dynamic clamp was then to elicit a constant and calibrated increase of the motoneurone input conductance. The effect of the resulting shunt was investigated on repetitive discharges elicited by current pulses. Shunting inhibition reduced very substantially the firing frequency in the primary range without changing the slope of the current-frequency curves. The shift of the I-f curve was proportional to the conductance increase imposed by the dynamic clamp and depended on an intrinsic property of the motoneurone that we called the shunt potential. The shunt potential ranged between 11 and 37 mV above the resting potential, indicating that the sensitivity of motoneurones to shunting inhibition was quite variable. The shunt potential was always near or above the action potential voltage threshold. A theoretical model allowed us to interpret these experimental results. The shunt potential was shown to be a weighted time average of membrane voltage. The weighting factor is the phase response function of the neurone that peaks at the end of the interspike interval. The shunt potential indicates whether mixed synaptic inputs have an excitatory or inhibitory effect on the ongoing discharge of the motoneurone.

[Value of the association of D-dimer measurement and the evaluation of clinical probability in a non-invasive diagnostic strategy of pulmonary embolism]

New diagnostic tools in suspected pulmonary embolism complete the classical diagnostic strategy of pulmonary scintigraphy and pulmonary angiography to limit the indications of these two invasive investigations. In a prospective series of 204 consecutive patients with suspected pulmonary embolism the association of D-dimer measurement and clinical probability was assessed for the exclusion of the diagnosis of pulmonary embolism. The D-DI Liatest is a new generation, unitary, rapid and quantitative latex test with a comparative diagnostic performance to that of the reference ELISA test, and well adapted to emergency situations.The clinical probability was assessed by a quantitative score based on past history, clinical symptoms and signs. The positive diagnosis of pulmonary embolism was made by spiral CT scanner and/or pulmonary angiography, associated with Duplex ultrasonography of the leg veins in nondiagnostic results. The prevalence of pulmonary embolism was 42.6% and the absence of anticoagulation in patients considered not to have pulmonary embolism was associated with a thrombo-embolic incidence of 0.9% at 3 months. Fifty-six patients had D-dimer concentrations equal or inferior to the threshold of 500 microg/L; the sensitivity was 99% and the specificity 47% with a negative predictive value of 98% to 100% in cases with a low clinical probability. D-dimer measurement is reliable and has a high cost-benefit value in ambulatory patients with suspected of pulmonary embolism and is even more valuable when the clinical probability of this diagnosis is low.

Field and experimental evidence of preferential selfing in the freshwater mollusc Lymnaea truncatula (Gastropoda, Pulmonata)

We have conducted a thorough study of the mating system of Lymnaea truncatula, the intermediate host of the liver fluke, using three approaches: (i) a population genetics study, (ii) controlled pairings in the laboratory and (iii) a progeny-array analysis. The population genetics study revealed high levels of inbreeding in the studied populations, with strong clues that the extensive heterozygote deficiencies observed are due to selfing. However, Wahlund effects may also arise due to recolonisations from different source populations after bottleneck events. A breeding experiment helped to disentangle the mating system and the Wahlund effects, and showed that high levels of selfing occurred in isolation and in controlled pairings. However, the progeny-array analysis performed after a high-density culturing of the snails suggests that substantial outcrossing may also occur.