Mycolactone toxin induces an inflammatory response by targeting the IL-1ß pathway: Mechanistic insight into Buruli ulcer pathophysiology.

Mycolactone, a lipid-like toxin, is the major virulence factor of Mycobacterium ulcerans, the etiological agent of Buruli ulcer. Its involvement in lesion development has been widely described in early stages of the disease, through its cytotoxic and immunosuppressive activities, but less is known about later stages. Here, we revisit the role of mycolactone in disease outcome and provide the first demonstration of the pro-inflammatory potential of this toxin. We found that the mycolactone-containing mycobacterial extracellular vesicles produced by M. ulcerans induced the production of IL-1ß, a potent pro-inflammatory cytokine, in a TLR2-dependent manner, targeting NLRP3/1 inflammasomes. We show our data to be relevant in a physiological context. The in vivo injection of these mycolactone-containing vesicles induced a strong local inflammatory response and tissue damage, which were prevented by corticosteroids. Finally, several soluble pro-inflammatory factors, including IL-1ß, were detected in infected tissues from mice and Buruli ulcer patients. Our results revisit Buruli ulcer pathophysiology by providing new insight, thus paving the way for the development of new therapeutic strategies taking the pro-inflammatory potential of mycolactone into account.

Cutaneous basidiobolomycosis: Seven cases in southern Benin.

BACKGROUND: Cutaneous basidiobolomycosis is the most common form of entomophthoramycosis. Herein we report seven cases of cutaneous basidiobolomycosis. PATIENTS AND METHODS: A retrospective observational study was conducted at the Buruli ulcer treatment centre in Pobè and at the national teaching hospital in Cotonou from 2010 to 2015. RESULTS: Seven cases of cutaneous basidiobolomycosis were diagnosed. The mean patient age was 9.53 years. There were 4 female and 3 male patients, all from southeast Benin. Clinically, the disease presented in all cases as a hard, well-defined, subcutaneous plaque with little inflammation, and which could easily be lifted from the deep structures but remained attached to the surface structures. The overlying skin was hyperpigmented. Plaques were localized to the buttocks or thighs. All patients had inflammatory anaemia with an accelerated erythrocyte sedimentation rate (30 to 70mm over the first hour), and a low haemoglobin count (8.7 to 11.4g/dL). Blood hypereosinophilia (650 to 3784elements/mm3) was present in six of the seven subjects. Histopathology (performed for 5 of the 7 subjects) showed granulomatous lesions with foreign-body giant cells, and inflammatory cells, with occasional eosinophils surrounding fungal hyphae (Splendore-Hoeppli phenomenon). Mycological analysis revealed Basidiobolus ranarum in three cases. The patients were treated with ketoconazole (5/7) and itraconazole (2/7), with good outcomes after 10 to 24 weeks of therapy. DISCUSSION: Cutaneous basidiobolomycosis is uncommon in southern Benin, with only seven cases being diagnosed over 6 years. The diagnosis of cutaneous basidiobolomycosis is a challenge in the field in Benin due to the non-specific clinical presentation, the lack of technical resources, and the existence of numerous differential diagnoses. CONCLUSION: Cutaneous basidiobolomycosis is an uncommon fungal infection in southern Benin chiefly affecting children.

[Rhinofacial conidiobolomycosis associated with cervical, thoracic and brachial localizations: one clinical case in Nigeria]. / Conidiobolomycose rhinofaciale avec localisations cervicales, thoraciques et brachiales: à propos d'un cas nigérian.

We report here the clinical case of a Nigerian adult patient who received medical care during October 2010, at the Center for Diagnosis and Treatment of Buruli ulcer in Pobè (Benin). He presented a massive facial tumor associated with several subcutaneous (cervical, thoracic and upper limbs) nodules, evolving since several years. Tissue samples collected at Pobè medical center were addressed to the mycology and histology laboratories of Angers University Hospital (France), according to the medical exchange agreement between the two institutions about the diagnosis and treatment of Buruli ulcer disease. Histological examination showed a Splendore-Hoeppli phenomenon, consisting of a granulomatous reaction made of eosinophilic polynuclear cells surrounding rare, large and irregular, non-septate hyphae. A filamentous fungus was isolated by cultivation of the clinical samples, which was identified as Conidiobolus coronatus. The patient was treated orally with daily doses of ketoconazole (400 mg per day). After 4 months of treatment, a marked regression of the facial lesion was obtained. A first constructive facial surgery was achieved, but the patient did not attend the second step. This case report allows us to remind the mycological diagnosis of this exotic mycosis, but also to emphasize the main difficulties encountered in medical management in the developing countries.

[Teaching and perception of urology by medical students at the end of the second cycle: an appraisal]. / Enseignement et perception de l'urologie à la fin du deuxième cycle des études médicales: état des lieux.

OBJECTIVES: Our purpose was to determine how the medical students from the second cycle perceived urology and what their learning methods were. MATERIAL AND METHODS: An e-questionnaire was sent to 1600 students in 16 teaching faculties during the last year of their second cycle. RESULTS: Overall, we obtained 590 answers (36.8%). In our population, 70.2% of the students were women. Of them, 24.1% had been already enrolled in an academic urology unit. Urology was defined as a medical, surgical and medico-surgical discipline by 3.7%, 37.8% and 58% of the students, respectively. Urology was considered as very important, important, not very important and not important at all by 5.1%, 54.4%, 37.5% and 2.4% of the students. The teaching methods used to learn urology were duplicated-notes for ENC preparation (45.3%), conferences for ENC (French national ranking exam) preparation (43.7%), courses of the national urology college (38.6%) and courses of the faculty (32%). The best mastered items were lithiasis disease (86.3%), voiding dysfunction (76.3%) and urological cancers (56.7%). On the contrary, only 34.7% and 28% considered their knowledge sufficient on the erectile dysfunctions and on renal transplantation. Lastly, 7.3% intended to become urologists. Having a work experience in a urology unit was significantly associated to the feeling of being prepared to become an intern (p<0.001) and to the project of becoming a urologist (p<0.001). CONCLUSION: Urology was considered like an important discipline by half of the students at the end of the second cycle even though it is under-represented in the national teaching programme for ENC. A third of the students used courses from the faculty to learn urology and a quarter of them had a work experience in a urology unit during their second cycle.

[Evidence-based medicine and French medical students: an appraisal]. / Evidence-based medicine et étudiants en médecine français : état des lieux.

INTRODUCTION: Nowadays, evidence-based medicine (EBM) is essential to learn and to practice medicine. The aim of the current study was to investigate the baseline level of knowledge of French students regarding EBM. MATERIALS AND METHODS: Between April and May2008, a questionnaire was sent by e-mail to 900students in their last year of medical study. RESULTS: On 327 answers, 297 (91%), 94 (29%) and 85 (26%) students declared they read, write and speak medical English. Ninety (28%) read an article of a French medical review once a month and 43 (13%) read an article of an international medical review once a month. Three hundred and eleven (95%) knew the bases of medical research on the Internet and 219 (67%) used them. Twenty-four (7%) had already participated in a editorial staff of a medical article, 7 (2%) had been co-authors. Two hundred and seventy-two (83%) had made an oral presentation during a medical staff and 3 (1%) during a congress. Finally, 237 (73%) understood the interest of the critical analysis of an article at the ECN and 70 (21%) thought they were prepared. CONCLUSION: The incapacity of learning EBM is one of the limits of the French medical training system. The introduction of the reading critical of an article at the ECN is the concrete beginning of an answer to this problem.

[Evaluation of the practical skills of final year medical students: example of bladder catheterization]. / Evaluation des compétences pratiques en fin de deuxième cycle des études médicales: exemple du drainage du bas appareil urinaire.

INTRODUCTION: When performed incorrectly, bladder catheterization can cause iatrogenic complications, especially urinary tract infections and trauma. The objective of this study was to determine the capacity of final year medical students to perform the various bladder catheterization techniques. MATERIAL AND METHODS: Between January and March 2007, a catheterization self-administered questionnaire was sent by e-mail to a representative sample of final year medical students, two months before the national classifying examination. RESULTS: Two hundred and seventy-seven questionnaires were returned and analysed. Seventy-two students (26%) considered that they were able to perform bladder catheterization in males and 106 (38.3%) in females at the end of their medical training. Seventy-one out of 277 (25.5%) students had completed an urology term during their training and 53.5% of them considered that they had acquired the indwelling catheter technique in males (p<0.001) versus 39 (54.9%) in females (p<0.001). Seventy-three students (26.4%) considered that they were able to perform intermittent catheterization in males or females and only one student was able to perform suprapubic catheterization. CONCLUSION: Teaching of catheterization procedures is inappropriate during medical training and young doctors consider themselves unable to perform these techniques at the end of their training. This is unfortunate, as all doctors should be able to perform catheterization as part of their daily practice, especially in hospital. This study indicates the need for improved teaching of essential medical procedures during undergraduate medical training.

C-cell hyperplasia.

Routine calcitonin assay programs and recent studies on the natural history of familial medullary thyroid carcinoma (MTC) have greatly added to our understanding of C-cell hyperplasia (CCH) and refined its classification. This article is an update on CCH physiopathology related to clinical presentation. With this combined approach, two types of CCH that differ by their physiological characteristics can be identified: neoplastic CCH and reactive (also called physiological) CCH. Neoplastic CCH is caused by a germline mutation of the RET protooncogene in a multiple endocrine neoplasia type 2 (MEN 2) syndrome. It progresses to MTC following a time line that depends on the RET mutation involved. CCH may actually be a misnomer for a neoplastic condition that some authors have proposed to call "in situ-MTC". Reactive CCH is considered to be caused by a stimulus that is external to the C-cell, and its premalignant potential is not documented. Many situations such as hypercalcemia, hyperparathyroidy, chronic lymphocytic thyroiditis or follicular tumors have been associated with reactive CCH, the pathogenesis of which remains unclear. But C-cell density in normal patients is subject to important variability, and several studies have demonstrated the dramatic male predominance in physiological CCH when hypercalcitoninemia was a random discovery. These data suggest that a number of conditions which were previously associated with reactive CCH might be purely fortuitous. Our clinical/pathological confrontation contributes to appropriately distinguishing between various CCH types, and in turn to identify the best way of managing patients.

[Evaluation of the attitude towards disabled persons of 3rd and 4th year medical students using the "Attitude towards disabled persons" questionnaire. Effect of courses and rotations in physical medicine and rehabilitation departments]. / Evaluation de l'attitude vis-à-vis des personnes handicapées des étudiants en médecine de 3e et 4e année par le questionnaire "Attitude towards disabled persons". Effets de l'enseignement théorique et de stages dans les services de médecine physique et réadaptation.

UNLABELLED: Modifications of the medical curriculum have included a compulsory course on disability. OBJECTIVE: To determine whether attendance in a course on disability and/or rotations in physical medicine and rehabilitation departments modify the attitude of medical students towards disabled people. METHODS: All third- and fourth-year students completed a translated version of the ATDPb. This questionnaire rates items evaluating attitude towards disabled people on a 6-point scale (minimum 0; maximum 180). Retro-translation was performed to control the translation. During the second year, all students had attended a general course in ethics. Fourth-year students had attended a 17 hours course on disability, and 21 of 78 had spent 9 weeks in the physical medicine and rehabilitation department. The study compares fourth-year students to third-year students, considered as controls, and students having spent a rotation in the physical medicine and rehabilitation department to others. RESULTS: The mean score of all students was 108.86+/-15.84 (73-160) on the ATDP scale. Males and females did not differ significantly, and the score did not change from that before the course on disability (109.95+/-14.98 vs 107.6+/-16.65, P=0.23) nor after a rotation in the physical medicine and rehabilitation department (113.52+/-11.42 vs 108.54+/-16.03, P=0.14). CONCLUSION: Development and validation of scores that would fit better to the European cultural context would be useful. The present method of theoretical courses and rotations do not improve the attitude of students towards disabled people and should be modified if this objective is to be achieved.

[Ecology and transmission of Mycobacterium ulcerans]. / Ecologie et mode de transmission de Mycobacterium ulcerans.

Mycobacterium ulcerans is an environmental pathogen concerning mainly the tropical countries; it is the causative agent of Buruli ulcer, which has become the third most important mycobacterial disease. In spite of water-linked epidemiological studies to identify the sources of M. ulcerans, the reservoir and the mode of transmission of this organism remain elusive. To determine the ecology and the mode of transmission of M. ulcerans we have set up an experimental model. This experimental model demonstrated that water bugs were able to transmit M. ulcerans by bites. In insects, the bacilli were localized exclusively within salivary glands, where it could both multiply contrary to other mycobacteria species. In another experimental study, we report that the crude extracts from aquatic plants stimulate in vitro the growth of M. ulcerans as much as the biofilm formation by M. ulcerans has been observed on aquatic plants. Given that the water bugs are essentially carnivorous, it is difficult to imagine a direct contact in the contamination of aquatic bugs and plants. It seems very likely that an intermediate host exists. In an endemic area of Daloa in Côte d'Ivoire, our observations were confirmed.

High field magnetic resonance imaging evaluation of superparamagnetic iron oxide nanoparticles in a permanent rat myocardial infarction.

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate superparamagnetic iron oxide (SPIO) nanoparticles to discriminate infarcted from normal tissue after myocardial infarction using high field MR imaging (7 tesla). MATERIALS AND METHODS: Permanent myocardial infarction was induced in rats. SPIO nanoparticles (1 mg Fe/kg) were assessed with T1-weighted gradient echo sequence to visualize the myocardial infarction 48 hours after ligature (n = 6). Furthermore, MR Imaging was performed using a T2-weighted RARE sequence and nanoparticles were injected (5 or 10 mg Fe/kg) on 36 rats 5, 24 or 48 hours after infarction. RESULTS: No changes in contrast between normal and infarcted myocardium was observed after nanoparticle injection on T1-weighted images. However, nanoparticles induced a significant contrast increase between normal and infarcted myocardium on T2-weighted images whatever the delay between infarction and imaging (2.99 +/- 1.66 preinjection vs. 7.82 +/- 1.96 after SPIO injection at a dose of 5 mg Fe/kg 5 hours postinfarction, P = 0.0001). CONCLUSIONS: Nanoparticle injection made it possible to discriminate normal from infarcted myocardium on T2-weighted images. However, the high magnetic field prevented the visualization of the T1 effect of SPIO nanoparticles.

[Pelvic malignant ectomesenchymoma: a case report]. / Ectomésenchymome malin pelvien. A propos d'un cas.

We report the case of a 19 month old boy referred to our institution because of a pelvic tumor initially identified as an embryonal rhabdomyosarcoma and treated with surgery and chemotherapy. Eight years after the initial surgery, a local tumor recurrence with bone metastasis was found. Histological examination and immunohistochemistry showed a double differentiation with both muscular and neuronal cells. This double differentiation was retrospectively found in the initial tumor, then allowing the diagnosis of malignant ectomesenchymoma also called gangliorhabdomyosarcoma. This rare tumor, occurring mainly during childhood, is composed of neuroblasts and / or ganglion cells and of malignant mesenchymal cells (usually rhabdomyosarcomatous cells).

High-field quantitative transverse relaxation time, magnetization transfer and apparent water diffusion in experimental rat brain tumour.

The potential of quantitative parameter images of transverse relaxation time T(2), apparent diffusion coefficient (ADC) and magnetization transfer ratio (MTR) to characterize experimental brain tumours was studied. Necrosis or haemorrhage can be detected using either MTR, ADC or T(2) (necrosis-MTR reduced by 35%, ADC and T(2) increased respectively by 170% and 100% compared with normal brain tissue; haemorrhage-MTR increased by 60%, ADC and T(2) decreased by 40% and 20%, respectively). Normal brain tissue can only be distinguished from tumour on T(2) and MTR parameter images. However, for small tumours (10 microl), the best contrast is observed with MTR, ca. 30%, whereas for T(2) the contrast is ca. 10%.

[Diagnosis of parathyroid cysts: value of parathyroid hormone level in puncture fluid]. / Diagnostic des kystes parathyroïdiens: intérêt du dosage de la parathormone dans le liquide de ponction.

OBJECTIVE: Determine a means of establishing the diagnosis of parathyroid cysts preoperatively. PATIENTS AND METHODS: Classically, crystal-clear watery fluid removed by fine-needle aspiration of a suspected thyroid mass raises the suspicion of a parathyroid cyst. Immunoradiometric assay of parathyroid hormone level in the fluid may give the diagnosis sparing unnecessary surgery. RESULTS: Over the last 5 years, among the 12 patients presenting a suspected thyroid cyst containing a crystal-clear fluid, we were able to diagnose 3 cases of parathyroid cysts due to the considerable elevation of parathyroid hormone in the puncture fluid. None of these patients had hyperparathyroidism. In patients with a thyroid cyst, parathyroid hormone level in the puncture fluid was nil. CONCLUSION: The parathyroid nature of cervical cysts containing crystal-clear fluid can be established by assaying parathyroid hormone in the puncture fluid. Non-functional parathyroid cysts may be treated by repeated aspiration. Serum calcium level must be checked regularly to detect potential hyperparathryoidism.

Hepatic hyper-vitaminosis A: importance of retinyl ester level determination.

We report the case of a 32-year-old man with portal hypertension without cirrhosis due to chronic vitamin A intoxication. Portal hypertension revealed by oesophageal varice rupture progressively worsened and ascites occurred 5 years after the patient stopped vitamin A intake. Initially, serum retinyl palmitate concentration was increased whereas serum retinol concentration was normal. There was no hepatic fibrosis on light microscopic examination of liver biopsy specimens. Five years after the patient stopped excessive vitamin A intake, serum retinol and retinol-binding protein concentrations were below the normal range even though there was an increased hepatic retinyl ester content. This was attributed to the late development of peri-sinusoidal fibrosis. This case mainly shows the importance of retinyl ester level determination: serum retinyl palmitate should be measured immediately after intoxication and hepatic retinyl esters should be measured initially and particularly later. Indeed, later serum and hepatic retinol levels in chronic hyper-vitaminosis A may be normal and lead to under-estimation of liver vitamin A overload.

MRI study of transient cerebral ischemia in the gerbil: interest of T2 mapping.

RATIONALE AND OBJECTIVES: The aim of this study was to evaluate the diagnostic use of MRI and, more precisely, the use of quantitative T2 imaging at 7 T for the early detection of neuronal cerebral alterations after transient ischemia in the gerbil. METHODS: One hundred forty-seven Mongolian gerbils were separated into four groups for which a bicarotid artery occlusion lasted for 4, 6, 8, or 10 minutes, respectively. The animals were scanned before carotid artery occlusion and at 3, 6, 10, 24, and 48 hours and 5 days after the ischemic incident. MR images were acquired on a Bruker Avance DRX300 mini-imaging system. RESULTS: Our results show that T2 mapping is able to localize brain damage induced by transient ischemia and to detect early perturbations in water content (as early as 6 hours after ischemia). CONCLUSIONS: T2 measurements in the striata are correlated with the severity of the ischemic incident, since the changes observed on the T2 images are directly proportional to the duration of occlusion.

Medullary thyroid microcarcinoma: a clinicopathologic retrospective study of 38 patients with no prior familial disease.

Thirty-eight patients (25 women, 13 men; mean age, 57.8 [32 to 91]) showing one or more medullary thyroid microcarcinomas (ie, < 1 cm), with no prior MEN II or medullary thyroid carcinoma history in their family, were reviewed. Follow-up was available for 29 patients (mean, 53.6 months [1 to 147]). 21 patients (72.4%) are alive and free of disease, four patients (13.8%) died during follow-up without disease, 2 patients are alive with disease (local recurrence and persistent hypercalcitoninemia) after 80 and 99 months, respectively, and 2 patients died of disease after 24 and 46 months. Most tumors were incidental pathological findings (19 of 38) or were discovered by systematic blood calcitonin measurement for a nodular thyroid disease (15 of 38). Only the four patients who had an unfavorable outcome were symptomatic cases (palpable micro-MTC, diarrhea, cervical lymph node metastasis and pulmonary metastatic disease). The two patients with metastatic disease at diagnosis died during follow-up. In univariate analysis, a symptomatic medullary thyroid carcinoma was a strong predictor of an unfavourable outcome (p < .00008), as were the preoperative calcitonin level (P = .007) and an elevated postoperative calcitonin level (P = .004). Among 30 histopathological criteria, only the presence of amyloid correlated with an unfavorable outcome (P = .018).

Local and sustained delivery of 5-fluorouracil from biodegradable microspheres for the radiosensitization of glioblastoma: a pilot study.

BACKGROUND: The authors have developed a new method of drug delivery into the brain using implantable biodegradable microspheres. In this study, this method was used to provide localized and sustained delivery of 5-fluorouracil (5-FU) after the surgical resection of glioblastoma. This antimetabolite and radiosensitizing drug was selected in an attempt to decrease the rate of local recurrence of the tumor. METHODS: Eight patients with newly diagnosed glioblastoma were included in the study and 2 increasing amounts of 5-FU were studied (70 mg and 132 mg). After surgical resection of the tumor, poly(D-L lactide-co-glycolide) 5-FU-loaded microspheres with an average dimension of 45 microm were implanted in the wall of the surgical bed. External beam radiation (59.4 grays) was initiated before the seventh postsurgical day. Patients were followed by clinical examination, magnetic resonance imaging, and 5-FU assays in the blood and cerebrospinal fluid (CSF). RESULTS: 5-FU assays confirmed sustained concentrations in the CSF for at least 1 month. Concentrations of 5-FU in the blood were lower and transitory. Systemic tolerance to the treatment was good; one case of recurrent brain swelling was observed at the higher dose studied. At the time of last follow-up the overall median survival time was 98 weeks from the time of implantation and 2 patients had achieved disease remission at 139 and 153 weeks, respectively. CONCLUSIONS: This study demonstrates that biodegradable microspheres are efficient systems for drug delivery into the brain and may have future application in the treatment of brain tumors. Further studies are needed to confirm the potential of 5-FU-loaded microspheres for the radiosensitization of glioblastoma. [Please see editorial on pages 197-9, this issue].