Carboxypeptidases B of Anopheles gambiae as targets for a Plasmodium falciparum transmission-blocking vaccine

Anopheles gambiae is the major African vector of Plasmodium falciparum, the most deadly species of human malaria parasite and the most prevalent in Africa. Several strategies are being developed to limit the global impact of malaria via reducing transmission rates, among which are transmission-blocking vaccines (TBVs), which induce in the vertebrate host the production of antibodies that inhibit parasite development in the mosquito midgut. So far, the most promising components of a TBV are parasite-derived antigens, although targeting critical mosquito components might also successfully block development of the parasite in its vector. We previously identified A. gambiae genes whose expression was modified in P. falciparum-infected mosquitoes, including one midgut carboxypeptidase gene, cpbAg1. Here we show that P. falciparum up-regulates the expression of cpbAg1 and of a second midgut carboxypeptidase gene, cpbAg2, and that this up-regulation correlates with an increased carboxypeptidase B (CPB) activity at a time when parasites establish infection in the mosquito midgut. The addition of antibodies directed against CPBAg1 to a P. falciparum-containing blood meal inhibited CPB activity and blocked parasite development in the mosquito midgut. Furthermore, the development of the rodent parasite Plasmodium berghei was significantly reduced in mosquitoes fed on infected mice that had been immunized with recombinant CPBAg1. Lastly, mosquitoes fed on anti-CPBAg1 antibodies exhibited reduced reproductive capacity, a secondary effect of a CPB-based TBV that could likely contribute to reducing Plasmodium transmission. These results indicate that A. gambiae CPBs could constitute targets for a TBV that is based upon mosquito molecules.

Evaluation of postural stability by means of a single inertial sensor

Human posture control during standing is a combination of many complicated control processes. Physical therapists perform different clinical balance tests to either assess postural control or identify balance disorders that can ultimately cause a patient to fall. In this article, several standardized clinical exercises for balance assessment are executed together with an orientation tracker strapped onto the volunteer's sternum. The tracker estimates the 3-D orientation of the trunk in real-time using an efficient attitude determination algorithm. The device is fully portable and sensitive to anteroposterior and mediolateral sways. Analysis of the resulting angles provides several parameters that are useful in assessing and quantifying balance function. This approach could be a valuable tool for a therapist for patient's follow-up and could be combined with existing procedures such as force platforms or optical motion analysis systems. Also, statistical analysis on these parameters could help to characterize normal and pathological performances in a population.

Chromatographic alignment combined with chemometrics profile reconstruction approaches applied to LC-MS data

This paper presents a full proteomics analysis LC-MS (Liquid Chromatography-Mass Spectrometry) chain combining bio, nano and information technologies in order to quantify targeted proteins in blood sample. The objective is to enable an early detection of pancreatic cancer. We focus on the data processing step which estimates the proteins' concentration. First, we pre-process the data in order to correct time shift between the experiments. We propose to use block matching algorithm. Second, quantification of protein is performed using chemometrics approaches and more precisely CLS, PLS, N-PLS and PARAFAC algorithms. Performances of the various methods have been compared on cytochrome c protein LC-MS analyses.

[Optic disc metastasis from pulmonary adenocarcinoma]

INTRODUCTION

Ocular metastases are becoming less and less rare. However, the optic nerve remains an exceptional site of metastases. Metastases to the optic disc account only for 4.5% of all intraocular metastases and are most of the time accompanied by an adjacent juxtapapillary choroidal component.

OBSERVATION

We report the case of a 65 year-old man presenting an unilateral impairment of visual acuity at the left eye. This man is treated for lung cancer. The left optic disc shows a diffuse yellow thickening and flame-shaped hemorrhages. The diagnosis of an optic disc metastasis was retained according to the ophthalmoscopy and various complementary investigations.

DISCUSSION

The optic disc metastasis can occur in a well-known cancer history but may sometimes be the first manifestation of it. Breast and lung cancers are the most common primary neoplasms. Women are more affected than men. The mean age at the time of ocular diagnosis is 55 years. The prognosis is poor because optic nerve metastases occur in advanced metastatic cancer. The mean survival is 13 months after ocular diagnosis. The mean treatments are external radiotherapy associated with systemic chemotherapy.

CONCLUSION

Presence of an optic disc lesion may suggest the possibility of a papillary metastasis despite the lack of a cancer history.

Ericksonian hypnosis in tinnitus therapy

OBJECTIVE

To evaluate the effect of Ericksonian therapy on tinnitus

STUDY DESIGN

Non-randomised, prospective longitudinal study.

SETTING

Tertiary referral centre.

PATIENTS

A total of 49 patients underwent hypnosis therapy. Fourteen patients failed to finish the therapy (drop-out rate: 35%). Of the 35 patients who completed the therapy, 20 were male and 15 female. The average age was 46.3 years (range 17-78).

INTERVENTION

The treatment is based on the principles and approaches of Ericksonian hypnosis. The first session was mainly dedicated to the evaluation of the impact of tinnitus on the patient's life and to an explanation of hypnosis therapy. The next sessions were "learning sessions" based on relaxation and mental imaging. Exercises were first based on all senses other than hearing. Then they focused on hearing, teaching patients how to modulate sound intensity, and finally how to modulate tinnitus intensity. Patients also learnt self-hypnosis.

MAIN OUTCOME MEASURE(S)

To evaluate the effect of the treatment, tinnitus was assessed with the Tinnitus Handicap Inventory questionnaire before and after the therapy.

RESULTS

After 5 to 10 sessions (mean: 8.09 + -1.92) of Ericksonian hypnosis therapy, the 35 patients were capable of self-hypnosis with the aim of modulating their tinnitus, and the measured THI score fell for all patients. The global score improved significantly from 60:23 before EH therapy to 16.9 at discharge. Within the group, the initial score was distributed as follows: 0% slight, 14% mild, 31% moderate, 31% severe and 23% catastrophic. The t-test for dependent variables revealed significant improvements in all subgroups (p < or = 0.005).

CONCLUSIONS

The results of this clinical trial demonstrate that Ericksonian hypnosis, in particular using self-hypnosis, is a promising technique for treating patients with tinnitus.

Paragangliomes malins héréditaires : problèmes liés à la prise en charge des formes non sécrétantes

Non-functional paraganglioma have not clinical or biological characteristics, so that the diagnostic is most of the time delayed and made on the occasion of advanced abdominal tumor or symptomatic metastasis management. Hereditary forms, notably those with SDHB mutation, seem to have a poor prognosis. On the other hand, and on the oposite to sporadic forms, they are the only ones to benefit from genetic testing which make possible, if positive, an earlier diagnostic, before apparition of symptoms, recurrence or metastasis. We report a case of non-functional malignant hereditary paraganglioma diagnosed belatedly and we will consider management problems raised by non-functional forms.

Transstadial and transovarial persistence of Babesia divergens DNA in Ixodes ricinus ticks fed on infected blood in a new skin-feeding technique

Although Babesia divergens is the the principal confirmed zoonotic Babesia sp. in Europe, there are gaps in our knowledge of its biology and transmission by the tick Ixodes ricinus. In order to reproduce the part of the parasite cycle that occurs in the vector, an in vitro animal skin feeding technique on blood containing in vitro cultivated B. divergens was developed. Parasite DNA was detected in all samples of salivary glands of nymphs and adults that had fed on parasitized blood as larvae and nymphs, respectively, indicating acquisition as well as a transtadial persistence of B. divergens. PCR performed on eggs and larvae produced by females that had fed on parasitized blood demonstrated the existence of a transovarial transmission of the parasite. Gorging B. divergens infected larvae on non-infected gerbils showed persistance of the parasite over moulting into the resulting nymphs. These results indicate that the parasitic stages infective for the vector (i.e. the sexual stages) can be produced in vitro. To our knowledge, this is the first report of artificial feeding of I. ricinus via membrane as well as in vitro transmission of B. divergens to its vector. The opportunities offered by the use of such a transmission model of a pathogen by I. ricinus are discussed.

Receptor-interacting protein 140 differentially regulates estrogen receptor-related receptor transactivation depending on target genes

We have investigated the effects of receptor-interacting protein 140 (RIP140) on transcriptional regulation by estrogen receptor-related receptors (ERRs). We first show that RIP140 inhibits transactivation by ERRalpha, beta, and gamma on natural or artificial reporter genes containing different types of response elements. This repression correlates with a strong in vitro binding between several regions of RIP140 and the three ERR isoforms. Surprisingly, although RIP140 inhibits transactivation of the thyroid hormone receptor-alpha gene by ERRbeta, it significantly increases its regulation by ERRalpha and ERRgamma. Mutagenesis and transient transfections in SL2 cells indicate that thyroid hormone receptor-alpha promoter expression involved Sp1 sites. In support of this observation, we demonstrate that RIP140 also positively regulates ERRs transactivation of other known Sp1 targets such as the p21 gene. This effect requires the two proximal Sp1 binding sites of the promoter and is partially dependent on the activation function 2 domain of ERRs. Finally, we provide evidences for a role of histone deacetylases in the regulation of p21 promoter by RIP140. Altogether, these data indicate that RIP140 differentially regulates ERR activity depending on the target sequence on the promoters.

Léiomyosarcome du segment moyen de la veine cave inférieure : problèmes tactiques soulevés par la revascularisation cave et rénale

INTRODUCTION

Leiomyosarcoma of the inferior vena cava is mesenchymal tumor accounting for 95% of primary tumors of the vena cava. Characteristic features include late invasion of adjacent structures and metastases, and delayed diagnosis.

OBSERVATION

We report a case of inferior vena cava (IVC) leiomyosarcoma (LMS) found in a 53 year-old man who complained of abdominal pain. Morphologic exams found a very large polycyclic mass in the inferior vena cava involving the middle segment of the vena cava extending from the renal veins to the hepatic veins. An "en bloc" resection of the tumor was achieved. Caval outflow was restored using a ring-reinforced PTFE tube graft, the left renal vein was ligated and not re-implanted, the right renal vein was implanted in a lumbar sub-renal vein using a short prosthesis. Pathological examination documented a grade II leiomyosarcoma of the inferior vena cava and the patient was given adjuvant chemotherapy (anthracycline). One year later, there was no local or regional relapse.

COMMENT

We emphasize the importance of restoring caval outflow which provides effective results when used with a ring-reinforced polytetrafluoroethylene (PTFE) prosthesis. Furthermore, the importance of restoring right renal outflow is highlighted because ligature of the renal vein can lead to renal ischemia and nephrectomy which should only be performed in specific cases. The tactical problems of renal and caval revascularisation, including the place of prosthetic replacement, are discussed.

cpbAg1 encodes an active carboxypeptidase B expressed in the midgut of Anopheles gambiae

We previously used differential display to identify several Anopheles gambiae genes, whose expression in the mosquito midgut was regulated upon ingestion of Plasmodium falciparum. Here, we report the characterization of one of these genes, cpbAg1, which codes for the first zinc-carboxypeptidase B identified in An. gambiae and in any insect. Expression of cpbAg1 in baculovirus gave rise to an active enzyme, and determination of the N-terminal amino acids confirmed that CPBAg1 contains a signal peptide and a pro-peptide, typical features of digestive zinc carboxypeptidases. cpbAg1 mRNA was mainly produced in the mosquito midgut, where it accumulated in unfed females and was rapidly down-regulated upon blood feeding. Annotation of the An. gambiae genome predicts twenty-three sequences coding for zinc-carboxypeptidases of which only two (cpbAg1 and cpbAg2) are expressed at a significant level in the mosquito midgut.

Plasmodium falciparum transmission blocking immunity under conditions of low and high endemicity in Cameroon

Transmission blocking immunity (TBI) was studied in relation to age, gametocyte density and transmission intensity. subjects with high gametocytaemias were selected in a hypo-endemic urban district and a hyper-endemic rural area in South Cameroon. TBI was determined in blood from gametocyte carriers in a bioassay (Direct Membrane Feeding Assay), with either autologous plasma (OWN) or control serum (AB). Mosquito infection rates (IR) were compared. infection rates correlated positively with gametocyte and oocyst densities. Three TBI indicators were analysed: the proportion of transmission reducers (IRAB > IROWN, P < 0.01), the mean intensity of TBI (IRAB - IROWN), and the contribution of TBI to total inhibition [(IRAB-IROWN)/(100-IROWN)]. we could not discriminate between areas with regard to either the proportion of transmission reducers (urban 15% and rural 29%) or the mean levels of TBI (urban 10% and rural 9%), or contribution of TBI to total inhibition (urban 10% and rural 13%). there was no relationship between TBI indicators and age, but a trend of increasing values was observed with rising gametocytaemia, which was considered as a confusing factor. a multivariable analysis showed that the probability of being a reducer was 4.6 fold higher in the rural area than in the urban district.

Stage-specific effects of host plasma factors on the early sporogony of autologous Plasmodium falciparum isolates within Anopheles gambiae

Summary Quantitatively assessing the impact of naturally occurring transmission-blocking (TB) immunity on malaria parasite sporogonic development may provide a useful interpretation of the underlying mechanisms. Here, we compare the effects of plasma derived from 23 naturally infected gametocyte carriers (OWN) with plasma from donors without previous malaria exposure (AB) on the early sporogonic development of Plasmodium falciparum in Anopheles gambiae. Reduced parasite development efficiency was associated with mosquitoes taking a blood meal mixed with the gametocyte carriers' own plasma, whereas replacing autologous plasma with non-immune resulted in the highest level of parasite survival. Seven days after an infective blood meal, 39.1% of the gametocyte carriers' plasma tested showed TB activity as only a few macrogametocytes ingested along with immune plasma ended up as ookinetes but subsequent development was blocked in the presence of immune plasma. In other experiments (60.9%), the effective number of parasites declined dramatically from one developmental stage to the next, and resulted in an infection rate that was two-fold lower in OWN than in AB infection group. These findings are in agreement with those in other reports and go further by quantitatively examining at which transition stages TB immunity exerts its action. The transitions from macrogametocytes to gamete/zygote and from gamete/zygote to ookinete were identified as main targets. However, the net contribution of host plasma factors to these interstage parasite reductions was low (5-20%), suggesting that irrespective of the host plasma factors, mosquito factors might also lower the survival level of parasites during the early sporogonic development.

Histone deacetylase inhibition and estrogen receptor alpha levels modulate the transcriptional activity of partial antiestrogens

In this study, we have analysed the effects of histone deacetylase (HDAC) inhibition on estrogen receptor (ER) expression and on its transcriptional activity in response to antiestrogens. In several breast cancer cell lines, trichostatin A (TSA), a potent HDAC inhibitor, strongly decreases ERalpha expression in a dose-dependent manner. This repression is observed independently of the presence of ligand and also occurs in ovarian and endometrial cell lines. In addition, we show that in MCF7 cells bearing a stably transfected reporter plasmid (MELN cells), partial antiestrogens such as 4-OH-tamoxifen (OHTam), raloxifen or LY117018, switch to an agonist activity upon HDAC inhibition. This effect is blocked by the pure antiestrogen ICI182780 and exhibits a half-maximal concentration of OHTam equivalent to its affinity for ERalpha. The TSA-dependent decrease of ERalpha expression is required to induce the agonist switch of OHTam properties as it is lost in cells constitutively expressing exogenous receptors (MELN-ERalpha or ERbeta). By contrast, the transrepression activity of OHTam is abolished by TSA independently of the decrease of ERalpha expression. Interestingly, in MELN-ERalpha, ICI182780 remains inhibitory suggesting the involvement of HDAC-independent mechanisms. Finally, in the absence of TSA, transcriptional activity in response to OHTam is significantly raised in MELN cells expressing low levels of ERalpha after transfection of antisense oligonucleotides. In conclusion, inhibition of HDAC enzymatic activity and modulation of ERalpha levels tightly control the relative agonist activity of partial antiestrogens on a stably integrated reporter transgene.

Multiple domains of the Receptor-Interacting Protein 140 contribute to transcription inhibition

In this study, we have investigated the role of C-terminal binding proteins (CtBPs) and histone deacetylases (HDACs) in the repressive activity of the nuclear receptor cofactor Receptor-Interacting Protein 140 (RIP140). We have defined the interaction of both CtBP1 and CtBP2 with RIP140 and delineated two motifs (PIDLS and PINLS) differentially required for in vitro interaction. Using different approaches (titration of endogenous CtBPs, mutagenesis and transfection in CtBP knock-out cells), we find that recruitment of CtBPs only partially explains the negative regulation exerted by RIP140. We then demonstrate that RIP140 associates in vitro not only with class I HDACs but also with class II enzymes such as HDAC5. This interaction mainly involves the N-terminus of RIP140 (residues 27-199) and two domains of HDAC5. Moreover, the two proteins functionally interfere in transfection experiments, and confocal microscopy indicates that they co-localize in the nucleus. Interestingly, using the specific HDAC inhibitor trichostatin A, we show that HDAC activity is dispensable for active transrepression by RIP140. Finally, we demonstrate that the C-terminal region of RIP140 contains two additional silencing domains and confers strong active transrepression independently of HDAC activity and CtBPs. Altogether, these data indicate that transcriptional inhibition by the cofactor RIP140 involves complex mechanisms relying on multiple domains and partners.

Body motion capture for activity monitoring

CEA-LETI has developed a 3D orientation tracker based on accelerometers and magnetometers. Owing to an efficient data fusion algorithm, the tracker provides accurate 3D orientation angles. The tracker is small enough to be used as a wearable device and therefore is an interesting tool for body motion capture. Investigations are being performed to analyse how activity of a person can be monitored from body motion measured with the tracker. In the domain of healthcare monitoring, many applications are envisaged such as rehabilitation with 3D body motion capture, elderly dependency evaluation, context acquisition for physiological monitoring.

[Cause of unusual unilateral vitreous hemorrhage: neuroretinitis of Cat-Scratch disease. Presentation of a case]

A 49 years old woman presents an unilateral decrease of vision. An important vitreous hemorrhage obscures the fundus. After partial resorption a typical aspect of neuroretinitis is seen: macular and disc edema with macular star formation. Cat-Scratch disease is suspected after general examination of the patient. This diagnosis will be confirmed by the laboratory investigation. This disease is not so rare and represents one of the principal causes of neuroretinitis. The vitreous hemorrhage can be due to vascular insult by the bacterium responsible for Cat-Scratch disease which one has an important tropism for endothelial cells and can be responsible for vascular occlusive phenomena. Clinical signs, treatment and evolution of this disease are going to be discussed in this article.

Estimation of malaria transmission from humans to mosquitoes in two neighbouring villages in south Cameroon: evaluation and comparison of several indices

Malaria transmission from humans to mosquitoes was assessed in two neighbouring villages in a rural area near Yaoundé, Cameroon during high and low transmission seasons during 1998-2000, using several indices previously evaluated in different areas endemic for malaria but never directly compared. These indices were estimated from human parasitological data and mosquito infection rates and, for each individual, thick blood films were prepared at the same time as experimental infection of laboratory-bred mosquitoes. Among the 685 volunteers examined, the prevalence of Plasmodium falciparum gametocyte carriers was 16%, and 8% of individuals were able to infect mosquitoes. The percentage of mosquitoes that became infected by feeding on the infectious individuals was 21%. Children aged < 10 years contributed to about 75% of the infectious reservoir, although they constituted only 35% of the total population. Differences were found between the transmission seasons and the villages, and varied according to the index examined. Although there were more infectious individuals in one of the two villages, they were less infectious than those in the other village during the high transmission season. Comparative analysis of the transmission indices suggests the existence of functioning transmission-blocking immunity in one of the villages, which until now has been only hypothetically considered to play a role in malaria transmission in a natural setting. The epidemiological value of all the indices used and their accuracy in estimating the human infectious reservoir and its natural or induced variations are discussed.

Level and dynamics of malaria transmission and morbidity in an equatorial area of South Cameroon

We conducted parasitological and entomological malaria surveys among the population of Mengang district in southern Cameroon to analyse the relationship between malaria transmission intensity and malaria morbidity. We investigated two adjacent areas which differ 10-fold in transmission intensity [annual entomological inoculation rate (EIR) 17 vs. 170], but have very similar Plasmodium falciparum malariometric profiles with parasite prevalences of 58 vs. 64%, high parasitaemia prevalences (> 1000 parasites/microl) of 15 vs. 16% and the same morbidity of 0.17-0.5 attacks/person/year. Plasmodium malariae prevalence was 14 vs. 16%. One possible explanation is that the similarity of the duration of the short and high transmission seasons in both areas is equally, if not more, significant for parasitological and clinical profiles as the annual EIR. We discuss the relationships between variations in transmission levels, parasitaemia and clinical incidence, and draw parallels to similar situations elsewhere.

[Grave complications of local anesthesia for cataract extraction: reports of 8 cases]

Cataract extraction performed under local anesthesia is not so safe. During a 2 years period, 8 patients have presented a complication: 3 patients are presented with diplopia, 4 patients are presented with eyeball perforation and 1 patient developed a central complication. All those complications are caused by the superior peribulbar injections of anesthetics. A survey of the different etiologies of the superior rectus muscle blow and of eyeball perforation is given.

Effect of chronic hypoxia on agonist-induced tone and calcium signaling in rat pulmonary artery

The effect of chronic hypoxia (CH) for 14 days on Ca2+ signaling and contraction induced by agonists in the rat main pulmonary artery (MPA) was investigated. In MPA myocytes obtained from control (normoxic) rats, endothelin (ET)-1, angiotensin II (ANG II), and ATP induced oscillations in intracellular Ca2+ concentration ([Ca2+]i) in 85-90% of cells, whereas they disappeared in myocytes from chronically hypoxic rats together with a decrease in the percentage of responding cells. However, both the amount of mobilized Ca2+ and the sources of Ca2+ implicated in the agonist-induced response were not changed. Analysis of the transient caffeine-induced [Ca2+]i response revealed that recovery of the resting [Ca2+]i value was delayed in myocytes from chronically hypoxic rats. The maximal contraction induced by ET-1 or ANG II in MPA rings from chronically hypoxic rats was decreased by 30% compared with control values. Moreover, the D-600- and thapsigargin-resistant component of contraction was decreased by 40% in chronically hypoxic rats. These data indicate that CH alters pulmonary arterial reactivity as a consequence of an effect on both Ca2+ signaling and Ca2+ sensitivity of the contractile apparatus. A Ca2+ reuptake mechanism appears as a CH-sensitive phenomenon that may account for the main effect of CH on Ca2+ signaling.

Chronic hypoxia-induced spontaneous and rhythmic contractions in the rat main pulmonary artery

The effect of chronic hypoxia (CH; 1-4 wk) on the electromechanical properties of the rat main pulmonary artery (MPA) was investigated. MPA rings obtained from rats exposed for 14 days to hypobaric (50.5 kPa) CH exhibited spontaneous and rhythmic contractions (SRCs) that were never observed in control (normoxic) rats. SRCs were unaffected by tetrodotoxin, phentolamine, BQ-123 and BQ-788, N-nitro-L-arginine methyl ester, or endothelium removal. CH depolarized smooth muscle cells from -58.8 +/- 9 to -38.6 +/- 5.4 mV and increased the resting cytosolic Ca2+ concentration from 67.3 +/- 11.9 to 112.5 +/- 16.4 nM. CH also induced spontaneous spikelike depolarizations. All of these effects were inhibited by external Ca2+ removal or nifedipine (1 microM). Moreover, depletion of intracellular Ca2+ stores with ryanodine (1-5 microM) or cyclopiazonic acid (3 microM) progressively attenuated SRCs. This study demonstrates that CH switches the MPA from a quiescent to a spontaneously active mechanical state. Finally, the fact that SRCs precede the development of right ventricle hypertrophy and disappear when this hypertrophy reaches a maximal value (after 3-4 wk of CH) suggests that SRCs may play a role in the adaptive process of the pulmonary circulation to CH.

Transcripts of the malaria vector Anopheles gambiae that are differentially regulated in the midgut upon exposure to invasive stages of Plasmodium falciparum

Understanding the interactions between the most deadly malaria parasite, Plasmodium falciparum, and its main vector, Anopheles gambiae, would be of great help in developing new malaria control strategies. The malaria parasite undergoes several developmental transitions in the mosquito midgut and suffers population losses to which mosquito factors presumably contribute. To identify such factors, we analysed An. gambiae midgut transcripts whose expression is regulated upon ingestion of invasive or non-invasive forms of P. falciparum using a differential display approach. Sixteen cDNA were studied in detail; 12 represent novel genes of An. gambiae including a gene encoding profilin. Four transcripts were specifically regulated by P. falciparum gametocytes (invasive forms), whereas the others were regulated by either non-invasive or both non-invasive and invasive forms of the parasite. This differential regulation of some genes may reflect the adaptation of P. falciparum to its natural vector. These genes may be involved in the development of P. falciparum in An. gambiae or in the defence reaction of the mosquito midgut towards the parasite.