Cerebral phaeohyphomycosis due to Cladophialophora bantiana in a French Guianese child.

We report a case of cerebral phaeohyphomycosis, a fungal brain infection due to a dark (dematiaceous) fungi in a 6-year-old French Guyanese boy. The child presented fever and drowsiness due to several paraventricular brain abscesses. Neurological surgeries were performed to reduce intracranial hypertension and to obtain abscess biopsies. Mycological cultures of intraoperative samples led to the diagnosis of cerebral phaeohyphomycosis due to Cladophialophora bantiana. The patient neurological status deteriorated and remained critical after several weeks of combination antifungal therapy with voriconazole 8mg/kg/day, liposomal amphotericin B 10mg/kg/day and flucytosine 200mg/kg/day. A complete surgical resection was not possible because of multiple small abscesses. A multidisciplinary ethical staff decided on home medical care with palliative ventriculoperitoneal shunt, nasogastric feeding and analgesics. One year later, the patient's neurological condition had improved and cerebral lesions had regressed, while he had not received any antifungal treatment but only traditional medicines. Cerebral phaeohyphomycosis are rare diseases affecting immunocompromised but also apparently non-immunocompromised patients, as in this case. A complete surgical resection is not always possible and mortality rates are high in spite of treatments with a combination of antifungals. The diagnosis may be difficult because of these dematiaceous fungi's slowly growing and their potential pathogenicity for laboratory staff.

[Suboptimal care and severe bacterial infection in the French Caribbean area]. / Soins sub-optimaux et infections bactériennes sévères communautaires aux Antilles françaises.

OBJECTIVE: To study the frequency and types of suboptimal care in initial management of children suffering from a severe bacterial infection (SBI), in a French region where little is known about pediatric SBI epidemiology. METHOD: Retrospective single-center study over a 6-year period. Children between 3 months and 15 years of age, deceased or surviving and admitted to the pediatric intensive care unit of the university-affiliated hospital of Martinique for a community-onset SBI were included in this study. The optimality of the medical care before admission to the pediatric intensive care unit was assessed in a blinded fashion by two independent experts. RESULTS: Twenty-nine of the 30 children suffering from SBI could be analyzed. The median age was 3.7 years (IQR: 1.7-10.4); the mortality rate was 14 % (95 % CI: 1-27 %). Most frequently infections were pulmonary infections (48 %; 95 % CI: 29-67 %), followed by septic shock (44 %; 95 % CI: 25-63 %). Microbiological cultures were positive in 55 % (95 % CI, 36-74 %) (n=16) of the cases, with five pneumococcus and four Streptococcus pyogenes. Of the 29 children included in the study, 72 % (95 % CI: 55-89 %) (n=21) had received at least one episode of suboptimal care. Suboptimal care comprised delay in diagnosis (identification of serious symptoms) in 65 % (95 % CI: 47-83 %), a delay in seeking care in 41 % (95 % CI: 22-60 %), and a delay in the initiation of antibiotics or hemodynamic support in 45 % (95 % CI: 26-64 %) and 38 % (95 % CI: 20-56 %) of the cases, respectively. CONCLUSION: Suboptimal care was frequent in the initial management of SBI, particularly because of a delay in seeking care and the failure of physicians to recognize early signs of SBI. A large public information campaign, focusing on healthcare accessibility and better education of physicians in the early recognition of SBIs are means of improvement that need to be explored.

[Assessment of screening for Down syndrome in Martinique from 2011 to 2013: An island location favoured]. / Évaluation du dépistage de la trisomie 21 en Martinique de 2011 à 2013 : une situation insulaire privilégiée.

OBJECTIVES: The aim of this study is to evaluate the screening for trisomy 21 (T21) between 2011 and 2013 on Martinique French West Indies after the decree of 23 June 2009. MATERIALS AND METHODS: Were used the prenatal data provided by accredited laboratories and the data from the Registry of Congenital French West Indies (REMALAN). RESULTS: A total of 85.9 % of patients underwent screening: 60.5 % on a combined calculation of risk (CRC), 14.6 % on a sequential calculation of risk (CRS) and 10.8 % on serum markers 2nd trimester (MST2). Overall 5.4 % of the patients were placed in a risk group. During this period, 47 trisomy 21 were identified by the REMALAN which 38 (80.1 %) were detected prenatally: 24 of CRC, 3 on MST2 and 11 on signs of ultrasound at the 1st and 2nd trimester. The sensitivity of the CRC was 88 % for a false positive rate of 3.87 %. The overall sensitivity of screening (CRC, CRS and MST2) was 87 % for a false positive rate of 5.21 %. CONCLUSION: These data show that the coverage rate in Martinique is satisfactory and the screening fir Down syndrome meet expectations.

[Fungal colonization in preterm neonates weighing less than 1500g admitted to the neonatal intensive care unit]. / Colonisation à levures chez les prématurés de moins de 1500g hospitalisés en réanimation néonatale.

Fungal colonization is a common occurrence in preterm neonates. Our objective was to describe the profile and characteristics of fungal colonization in preterm infants admitted to the Martinique NICU. From March 2012 to January 2013, an epidemiological prospective cohort study was conducted with 57 very low-birth-weight infants. Cutaneous, rectal, gastric, respiratory, and urinary swabs were collected on admission, then every week for 4 weeks. The prevalence of fungal colonization was 68% (39/57): 46% by Malassezia species, 28% by Candida parapsilosis, 19% by C. albicans, 5% by C. glabrata, and 2% by C. guilliermondii. The colonized patients had a duration of parenteral nutrition and antibiotic therapy longer than the others (P<0.05). Nosocomial colonization (after 2 days of life) occurred in 52% of cases: Malassezia species and C. parapsilosis were the commensal skin yeasts most frequently implicated. Forty-nine percent (28/57) had suspected invasive fungal infections that received probabilistic treatment. Only one case of invasive fungal infection with C. glabrata was diagnosed. This study highlights the important role played by nosocomial transmission in the colonization of preterm newborns. Mycological surveillance cultures in the NICU are very useful for monitoring fungal ecology and can improve the prevention of fungal colonization in preterm infants at risk of invasive fungal infection.

Subject-specific musculoskeletal model of the lower limb in a lying and standing position.

Accurate estimation of joint loads implies using subject-specific musculoskeletal models. Moreover, as the lines of action of the muscles are dictated by the soft tissues, which are in turn influenced by gravitational forces, we developed a method to build subject-specific models of the lower limb in a functional standing position. Bones and skin envelope were obtained in a standing position, whereas muscles and a set of bony landmarks were obtained from conventional magnetic resonance images in a lying position. These muscles were merged with the subject-specific skeletal model using a nonlinear transformation, taking into account soft tissue movements and gravitational effects. Seven asymptomatic lower limbs were modelled using this method, and results showed realistic deformations. Comparing the subject-specific skeletal model to a scaled reference model rendered differences in terms of muscle length up to 4% and in terms of moment arm for adductor muscles up to 30%. These preliminary findings enlightened the importance of subject-specific modelling in a functional position.

Porcine model of early onset scoliosis based on animal growth created with posterior mini-invasive spinal offset tethering: a preliminary report.

Several models of scoliosis were developed in the past 10 years. In most of them, deformations are induced in old animals and required long time observation period and a chest wall ligation ± resection. The purpose of the study was to create a scoliosis model with a size similar to an early onset scoliosis and an important growth potential without chest wall injuring. An original offset implant was fixed posteriorly and connected with a cable in seven (6 + 1 control) one-month-old Landrace pigs. The mean initial spinal length (T1-S1) was 25 cm and the mean weight was 9 kg. After 2 months observation, spinal deformities were assessed with a three dimension stereographic analysis. In four animals, the cable was sectioned and the deformities followed-up for next 2 months. No post-operative complication was observed. Mean weight growth was 10 kg/month and mean spine lengthening (T1-S1) was 7 cm/month. In 2 months, we obtained structural scoliotic curves with vertebral and disk wedging which were maximal at the apex of the curve. Mean frontal and sagittal Cobb angles was 45°. Chest wall associated deformities were similar to those observed in scoliotic deformities and were correlated to spinal deformities (p = 0.03). The cable section resulted in a partial curve regression influenced by disk elasticity and could probably be influenced by gravity loads (Decrease of the Cobb angle of 30% in the sagittal plane and 45% in the frontal plane). According to the results, the model creates a structural scoliosis and chest wall deformity that is similar to an early onset scoliosis. The spinal deformities were obtained quickly, and were consistent between animals in term of amount and characteristic.

Fast 3D reconstruction of the rib cage from biplanar radiographs.

The stereoradiographic reconstruction method allows obtaining the three-dimensional (3D) rib cage geometry, which is essential for clinical evaluation or biomechanical studies. However, reconstruction time is still high (about 20 min considering operator time). The purpose of this study is to propose a 3D reconstruction of the rib cage from biplanar radiographs, based on the deformation of a prepersonalized object. Validation in comparison with computed tomography (CT-scan) acquisitions was performed. Local parameters (rib length, cord length, maximum width, area, and rib orientations) were computed from reconstructions. Parameters' reproducibility was assessed with two observers and two measurements for 15 subjects. Regarding validation of the parameters, the mean difference with the CT-scan was between 6.3 and 1.3%. Observer variability was maximal for rib area (6.2%) and was lower than 4.2% for others parameters. The proposed reconstruction method reduced time (less than three minutes for operator time) to obtain a 3D reconstruction of the rib cage.

The degree and distribution of cortical bone mineralization in the human femoral shaft change with age and sex in a microradiographic study.

BACKGROUND: The incidence of osteoporotic hip fractures increases with age, more sharply in women than in men, as a result of qualitative and quantitative bone alterations. Mineralization (a qualitative parameter) showed no differences with age or sex in cancellous bone in earlier studies. Few studies assessed such differences in cortical bone, a major contributor to femoral bone strength. The aim of this in vitro cross-sectional study of a large group of human femoral midshafts was to look for age- and sex-related differences in the degree and distribution of cortical mineralization that might be implicated in bone fragility. METHODS: Cortical bone specimens from 193 femurs were studied using quantitative microradiography, with an aluminum step-wedge reference. The femurs were from 99 females and 94 males in a Caucasian anthropological collection covering a broad age spectrum. We determined the mean degree of mineralization of osteons (On.DMB-Al), interstitial tissue (Int.DMB-Al), and total bone (Tt.DMB-Al), and representative parameters of density histograms. Results were expressed as relative values. Age- and sex-related differences in DMB-Al values were evaluated using non-parametric tests. RESULTS: Degree of tissue mineralization (Tt.DMB-Al) decreased significantly with age in females (r=-0.257; P=0.010) but did not change in males. Tt.DMB-Al was higher in females than males until 50 years of age (P=0.001) but was lower in elderly females than elderly males (P=0.016). DMB-Al distribution varied significantly with sex and age. The first DMB-Al quartiles in osteons and interstitial tissue were not different between males and females, but the third quartile and interquartile range differed significantly (P=0.032 and P=0.000, respectively). The mineralization difference between the two tissues indicated greater bone heterogeneity in females than males (P=0.000). CONCLUSIONS: In this in vitro cross-sectional study of anterior midfemoral cortical specimens, the degree and distribution of mineralization varied with age and sex. In females, mineralization started at a higher level than in males but was lower in the sixth decade, falling below the level in males. Mineralization was far more stable throughout life in males. In elderly females, the lower degree and greater heterogeneity of mineralization may have consequences on bone strength and the risk of fracture.

3D-patient-specific geometry of the muscles involved in knee motion from selected MRI images.

Patient-specific muscle geometry is not only an interesting clinical tool to evaluate different pathologies and treatments, but also provides an essential input data to more realistic musculoskeletal models. The protocol set up in our study provided the 3D-patient-specific geometry of the 13 main muscles involved in the knee joint motion from a few selected magnetic resonance images (MRIs). The contours of the muscles were identified on five to seven MRI axial slices. A parametric-specific object was then constructed for each muscle and deformed to fit those contours. The 13 muscles were obtained within 1 h, with less than 5% volume error and 5 mm point-surface error (2RMS). From this geometry, muscle volumes and volumic fractions of asymptomatic and anterior cruciate ligament deficient subjects could easily be computed and compared to previous studies. This protocol provides an interesting precision/time trade-off to obtain patient-specific muscular geometry.

Volumic patient-specific reconstruction of muscular system based on a reduced dataset of medical images.

Three-dimensional mechanical modelling of muscles is essential for various biomechanical applications and clinical evaluation, but it requires a tedious manual processing of numerous images. A muscle reconstruction method is presented based on a reduced set of images to generate an approximate parametric object from basic dimensions of muscle contours. A regular volumic mesh is constructed based on this parametric object. The approximate object and the corresponding mesh are deformed to fit the exact muscles contours yielding patient-specific geometry. Evaluation was performed by comparison of geometry to that obtained by contouring all computed tomography (CT) slices, and by quantification of the mesh quality criteria. Muscle fatty infiltration was estimated using a threshold between fat and muscle. Volumic fat index (VFI) of a muscle was computed using first all the complete CT scan slices containing the muscle (VFI(ref)) and a second time only the slices used for reconstruction (VFI(recons)). Mean volume error estimation was 2.6% and hexahedron meshes fulfilled quality criteria. VFI(recons) respect the individual variation of fat content.

An anatomical subject-specific FE-model for hip fracture load prediction.

In order to reduce the socio-economic burden induced by osteoporotic hip fractures, finite element models have been evaluated as an additional diagnostic tool for fracture prediction. For a future clinical application, the challenge is to reach the best compromise between model relevance and computing time. Based on this consideration, the current study focused on the development and validation of a subject-specific FE-model using an original parameterised generic model and a specific personalization method. A total of 39 human femurs were tested to failure under a quasi-static compression in stance configuration. The corresponding FE- models were generated and for each specimen the numerical fracture load (FFEM) was compared with the experimental value (FEXP), resulting in a significant correlation (FEXP = 1.006 FFEM with r2 = 0.87 and SEE = 1220 N, p < 0.05) obtained with a reasonable computing time (30 mn). Further in vivo study should confirm the ability of this FE-model to improve the fracture risk prediction.

DNA protection mechanisms are not involved in the radioresistance of the hyperthermophilic archaea Pyrococcus abyssi and P. furiosus.

Hyperthermophilic archaea of the genus Pyrococcus are resistant to gamma radiation, suggesting that efficient mechanisms for DNA repair exist in these organisms. To determine whether protective mechanisms might also be implicated in this radioresistance, we have estimated the linear density of DNA double-stranded breaks caused by gamma irradiation in the genomic DNA of two Pyrococcus species, using Escherichia coli and the radioresistant bacterium Deinococcus radiodurans as controls. The linear density of double-stranded breaks was essentially the same in all four microorganisms when irradiation was carried under similar anaerobic conditions, indicating that no specific DNA protection mechanisms exist in Pyrococcus species. Using one- and two-dimensional gel electrophoresis we compared the protein patterns from Pyrococcus abyssi and P. furiosus cells that had or had not been exposed to gamma rays. We did not detect any significant protein induction following DNA damage in either species.

Growth kinetics of the granulosa cell population in ovarian follicles: an approach by mathematical modelling.

This paper describes, from a mathematical viewpoint, the cellular changes in the granulosa of ovarian follicles during their terminal development. A dynamic model takes into account the processes of (1) cell division, (2) exit from the cell cycle towards differentiation, and (3) apoptotic cell death. Proliferative cells leave the cycle in an irreversible way. The risk of entering apoptosis applies to non-cycling cells. Changes in the cell numbers and in the growth fraction are derived from differential equations. The transitions between the different cell states are ruled by time-dependent rates. Numerical applications of the model concern ovulating and degenerating ovarian follicles in the ewe. The main feature of the ovulating case is the progressive exhaustion of the proliferating compartment for the benefit of the non-cycling cells. From an initial mainly proliferative state the granulosa progressively switches to a highly differentiated state, so that the growth fraction continuously decreases. In the atretic cases, the pattern of changes in the total viable cell number is influenced by the follicular age at the onset of the apoptotic process and by the intensity of the cell death rate. As apoptosis affects the non-cycling cells, the growth fraction is no longer strictly decreasing. The sensitivity of the model to the parameters is studied in a more general framework than the granulosa cell population.

[Methodological approach to the circadian pattern of food intake in the growing domestic rabbit]. / Approche méthodologique de la répartition nycthémérale des prises d'aliment chez le lapin domestique en croissance.

We graphically recorded the feeding pattern of 9 New Zealand male rabbits during weeks 6, 9, 12, 15 and 18 of age. Feeding was considered as a periodic series of discrete events. We fitted a periodic Poisson process to each particular series. In order to determine if the model was a good representation of the time series, we compared the estimated density curves with non-parametric estimations of density. Approximation of the circadian pattern using the model was better from week 15 on. Before this age, 24-hour feeding activity was generally characterized by two peaks. The parameters of the model--average number of food intakes over a 24-hour period, time of highest feeding activity and scatter index--were easy to interpret. Age variations in circadian feeding pattern were mainly characterized by shortening of scatter and shifting of peak feeding activity from the beginning to the middle of the dark period between weeks 6 and 18.

[Mathematical model on the development of progesterone in the cow: application and proof of differences between breeds]. / Modèle mathématique de l'évolution de progestérone chez la vache: application et mise en évidence de différence entre races.

Peripheral plasma progesterone levels were compared in "Normandy" (6), "Charolais" (6) and French Friesian (6) heifers. The progesterone curves were fitted to mathematical models for the luteal phase (a logistic function) and for the luteolytic phase (an exponential model). 1. Discriminating and multivariate analyses showed a breed difference in luteal phase duration (17.8 +/- 1.1, 16.8 +/- 2.3, 16.1 +/- 1.06 days, respectively, for Normandy, Charolais and French Friesian heifers) and in the rate of progesterone level increase (1.1 +/- 0.4, 1.09 +/- 0.3, 1.3 +/- 0.3 ng/ml/day, respectively) (chi 2 = 22.5; P less than 0.02). 2. Progressive multiple regression showed the duration of the luteal phase was highly correlated to oestrous cycle duration (20.8 +/- 1.7, 20.5 +/- 2.8, 19.2 +/- 1.5 days, respectively) (r = 0.89). It appears that breed differences in bovine oestrous cycle duration are due to differences in luteal phase duration. 3. The rate of progesterone level increase reached a maximum at 7.2 +/- 0.8, 6.9 +/- 1.1 and 6.4 +/- 0.6 days, respectively, concomitant with maximal corpus luteum secretion. 4. The reproducibility of these parameters, summarizing the progesterone pattern during two consecutive oestrous cycles, showed that each animal had an individual secretion pattern.