Heterogeneous spatial tuning in the auditory pathway of the Mongolian Gerbil (Meriones unguiculatus).

Sound-source localization is based on spatial cues arising due to interactions of sound waves with the torso, head and ears. Here, we evaluated neural responses to free-field sound sources in the central nucleus of the inferior colliculus (CIC), the medial geniculate body (MGB) and the primary auditory cortex (A1) of Mongolian gerbils. Using silicon probes we recorded from anaesthetized gerbils positioned in the centre of a sound-attenuating, anechoic chamber. We measured rate-azimuth functions (RAFs) with broad-band noise of varying levels presented from loudspeakers spanning 210° in azimuth and characterized RAFs by calculating spatial centroids, Equivalent Rectangular Receptive Fields (ERRFs), steepest slope locations and spatial-separation thresholds. To compare neuronal responses with behavioural discrimination thresholds from the literature we performed a neurometric analysis based on signal-detection theory. All structures demonstrated heterogeneous spatial tuning with a clear dominance of contralateral tuning. However, the relative amount of contralateral tuning decreased from the CIC to A1. In all three structures spatial tuning broadened with increasing sound-level. This effect was strongest in CIC and weakest in A1. Neurometric spatial-separation thresholds compared well with behavioural discrimination thresholds for locations directly in front of the animal. Our findings contrast with those reported for another rodent, the rat, which exhibits homogenous and sharply delimited contralateral spatial tuning. Spatial tuning in gerbils resembles more closely the tuning reported in A1 of cats, ferrets and non-human primates. Interestingly, gerbils, in contrast to rats, share good low-frequency hearing with carnivores and non-human primates, which may account for the observed spatial tuning properties.

Diagnosis of primary antibody and complement deficiencies in young adults after a first invasive bacterial infection.

OBJECTIVES: Screening for primary immunodeficiencies (PIDs) in adults is recommended after two severe bacterial infections. We aimed to evaluate if screening should be performed after the first invasive infection in young adults. METHODS: Eligible patients were retrospectively identified using hospital discharge and bacteriology databases in three centres during a 3-year period. Eighteen to 40-year-old patients were included if they had experienced an invasive infection with encapsulated bacteria commonly encountered in PIDs (Streptococcus pneumoniae (SP), Neisseria meningitidis (NM), Neisseria gonorrhoeae (NG), Haemophilus influenzae (HI), or group A Streptococcus (GAS)). They were excluded in case of general or local predisposing factors. Immunological explorations and PIDs diagnoses were retrieved from medical records. Serum complement and IgG/A/M testings were systematically proposed at the time of study to patients with previously incomplete PID screening. RESULTS: The study population comprised 38 patients. Thirty-six had experienced a first invasive episode and a PID was diagnosed in seven (19%): two cases of common variable immunodeficiency revealed by SP bacteraemia, one case of idiopathic primary hypogammaglobulinaemia, and two cases of complement (C6 and C7) deficiency revealed by NM meningitis, one case of IgG2/IgG4 subclasses deficiency revealed by GAS bacteraemia, and one case of specific polysaccharide antibody deficiency revealed by HI meningitis. Two patients had previously experienced an invasive infection before the study period: in both cases, a complement deficiency was diagnosed after a second NM meningitis and a second NG bacteraemia, respectively. CONCLUSION: PID screening should be considered after a first unexplained invasive encapsulated-bacterial infection in young adults.

Cognitive Impairment and Basal Ganglia Functional Connectivity in Vascular Parkinsonism.

BACKGROUND AND PURPOSE: Patients with vascular parkinsonism have higher cognitive decline and more basal ganglia lesions. We aimed to evaluate the relationship of cognitive impairment with functional connectivity between the basal ganglia and cingulate cortex in vascular parkinsonism. MATERIALS AND METHODS: Thirty patients (8 with vascular parkinsonism and 22 with Parkinson disease) and 23 controls were enrolled. The Mattis Dementia Rating Scale and the Stroop Task were used to assess cognitive decline. MR imaging examinations included T1-MPRAGE, FLAIR, and resting-state fMRI sequences. MPRAGE was segmented to obtain basal ganglia and cingulate cortex volumes. FLAIR was segmented to obtain white matter hyperintensity lesion volume. Resting-state fMRI sequences were used to compare basal ganglia functional connectivity with the cingulate cortex between patients and controls. RESULTS: Patients with vascular parkinsonism exhibited impaired attention, resistance to interference, and inhibitory control and an increased number of errors on the Stroop Task. They also had higher caudate nucleus and white matter hyperintensity lesion volumes, which were positively correlated (ρ = 0.75, P < .0001). Caudate nucleus functional connectivity with the perigenual anterior cingulate cortex was increased in patients with vascular parkinsonism compared with controls and patients with Parkinson disease, and it was positively correlated with the caudate nucleus volume (ρ = 0.44, P = .016). Caudate nucleus functional connectivity with the posterior cingulate cortex was decreased in patients with vascular parkinsonism compared with controls and negatively correlated with the number of errors on the Stroop test (ρ = -0.51, P = .0003). CONCLUSIONS: In patients with vascular parkinsonism, cognitive decline could be related to changes of caudate nucleus functional connectivity with the cingulate cortex at resting-state, which may be induced by ischemia-related remodelling.

Novel Approach to Surface Plasmon Resonance: A Third Dimension in Data Interpretation Through Surface Roughness Changes.

In a Surface Plasmon Resonance (SPR) experiment two key parameters are classically recorded: the time and the angle of SPR reflectivity. This paper brings into focus a third key parameter: SPR reflectivity. The SPR reflectivity is proved to be related to surface roughness changes. Practical investigations on (i) gold anodizing and (ii) polypyrrole film growth in presence of oxalic acid is detailed under potentiostatic conditions. These experimental results reveal the potential of using the SPR technique to investigate real-time changes both on the gold surface, but also in the gold film itself. This extends the versatility of the technique in particular as sensitive in-situ diagnostic tool.

Growth of chromium carbide in a hot wall DLICVD reactor.

Chromium carbide coatings were grown at 748 K in a hot wall CVD reactor fed by sublimation of bis(benzene)chromium, BBC (MOCVD) and by direct liquid injection using a BBC/toluene solution (DLICVD). The two types of coatings exhibit an amorphous structure and the same C content (22 at.%). DLICVD permits delivering higher mass flow rate of precursors and consequently the growth rate is 3 times higher and the thickness uniformity is better than using MOCVD. Chromium metal deposition has also been investigated by DLICVD in this hot wall reactor using BBC/toluene/additive as precursor. The purpose of the additive is to block carbide formation. Two additives have been studied: (i) hexachlorobenzene (C6Cl6) and (ii) thiophenol (C6H5SH). The ratio additive/BBC required for Cr metal deposition is a few percent. In this process, C6Cl6 is not decomposed and only traces of Cl (0.4 at.%) are found in the coatings. For a ratio C6Cl6/BBC > 27% the growth of any coating is blocked. The gas phase containing C6H5SH is more reactive since the onset of deposition occurs approximately 50 K before the temperature of the chlorinated compound. Furthermore, a sulfur contamination of 3 at.% has been analyzed in the coatings revealing a partial decomposition of the additive. The results are detailed and discussed in relation with previous works.

Short-range evaluation of air pollution near bus and railway stations.

In the early morning, during workdays, intensive activity is observed at both bus and railway stations. This particular time is critical because of the combination of three factors: (1) simultaneous departure of many buses and trains, (2) cold engines, and, quite frequently, (3) stable meteorological conditions. In our approach, we use ARIA Local, a simulation package applying CFD tools to air pollution modeling, to study different scenarios. The CFD model used in this study is the MERCURE model, developed by Electricite de France. For a bus station, we simulate a typical morning peak hour situation and study in detail how the pollution is accumulated in the station courtyard and the impact on the close vicinity. Two scenarios are presented: one with classical diesel engine and one with buses using AQUAZOL or NGV fuel. The definition of the sources inside the Eulerian grid is described as static linear sources. The total emission is averaged over the mean path driven by the bus from the bus stop to the exit of the bus station. For a railway station, we simulate a situation in a real railway station within the city of Paris. The emission from a diesel "locomotive" and its impact on air quality is computed and compared to the impact of other nonmobile emissions. In this case, the definition of sources is described as mobile point sources following the trajectory of the train. These two scenarios are discussed in an urban context, taking into account the flow around buildings and different meteorological conditions.

[Melkersson-Rosenthal syndrome: anatomo-clinical and evolutive concepts]. / Syndrome de Melkersson-Rosenthal. Concepts anatomo-cliniques et évolutifs.

PURPOSE: To inform ophthalmologists about the Melkersson-Rosenthal Syndrome. A new clinical classification is suggested. METHODS: Commented observation and review of the litterature. RESULTS: The presented case is characterized by an exclusive involvement of orbital sphere, due to inflammation of palpebral and orbital fat. CONCLUSION: Melkersson-Rosenthal Syndrome can be divided into type 1 characterized by perioral lesions and type 2 characterized by periocular lesions, with preferential involvement of fat and evolution towards fibrosis.

Assimilation of [57Co]-labeled cobalamin in human fetal gastrointestinal xenografts into nude mice.

Cobalamin (Cbl) and its Cbl-binding proteins are present in amniotic fluid. Because amniotic fluid is swallowed by the embryo-fetus, we studied the ability of Cbl to be transported and metabolized across the embryo-fetal digestive tract. Human embryonic stomachs and intestines were transplanted into nude mice. The basal secretion of Cbl-binding proteins was studied by gel filtration of the graft juices. Intrinsic factor (IF) was looked for in gastric mucosa by immunohistochemistry. The uptake of [57Co]-labeled Cbl by the intestinal graft was studied by Schilling tests and HPLC. IF, haptocorrin, and a transcobalamin-like protein were detected in gastric juice, with concentration ranges of 5.0-26.4, 1.9-27.1, and 5.2-12.6 pmol/mL, respectively. The IF [57Co]Cbl complex had a single isoprotein with a pI at 5.6, which was maintained after incubation with neuraminidase. Urine excretion percentages (Schilling tests) ranged from 5.5 to 21.2% and from 0.3 to 1.6% when cyano-[57Co]Cbl-IF or cyano-[57Co]Cbl, respectively, was instilled in intestinal grafts. Chloroquine reduced significantly the percentage of excreted [57Co]Cbl. The [57Co]Cbl was mainly excreted as cyano-[57Co]Cbl in urines, showing a low coenzyme conversion. In conclusion, IF is secreted by the nonstimulated embryonic stomach and lacks sialic acid. Cbl binds to it and is subsequently transported across the xenografted embryo-fetal intestine. This suggests that amniotic fluid may contribute to Cbl delivery to the embryo-fetus.

Comparison between serum alpha-glutathione S-transferase and aminotransaminases in detecting cytolysis in hepatitis C-infected children.

BACKGROUND: alpha-Glutathione S-transferase (alphaGST) has been proposed as a more sensitive indicator than serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in detecting hepatocellular damage due to chronic hepatitis C virus (HCV) infection. METHODS: The accuracy of alpha-GST was compared with that of ALT and AST in detecting cytolysis in 103 blood samples issued from 31 children positive for HCV RNA. RESULTS: alpha-GST had a lower sensitivity than ALT or AST (32% vs. 54.4% for each aminotransferase). The sensitivity of ALT and/or AST was 60.2%, whereas that of ALT and/or alpha-GST and AST and/or alpha-GST was lower (58.3% and 57.3%, respectively). Among 41 serum samples with negative ALT and AST, only 2 had positive alpha-GST, whereas alpha-GST failed to detect cytolysis in 31 samples with elevated ALT and/or AST. No correlation was found between alpha-GST, ALT, or AST and the Knodell score. CONCLUSIONS: The combination of ALT with AST is actually the best compromise in detecting cytolysis in untreated HCV-infected patients.

[Ovarian Leydig cell tumor of stromal localization]. / Tumeur ovarienne à cellule de Leydig de localisation stromale.

We report the case of a 63-year-old, menopausal patient, yielding hirsutism an associated with clinical virilization. Biological data evidenced an increased androgen production (plasma testosterone at 1.8 and 2.1 ng/ml). Radiological exams (ultrasonography, CT Scan and MRI Scan) failed to find any ovarian tumor, which led to perform an ovarian selective venous percutaneous catheterization. A stromal Leydig cell tumor, associated with a hilar leydigian hyperplasia, was evidenced in pathology. Clinical, biological, radiological and pathological data are successively discussed. Pathophysiology of Leydig cell tumor, particularly when located in the ovarian stroma is also reviewed.

[Extra-cardiac rhabdomyoma of the fetal type]. / Rhabdomyome extra-cardiaque de type foetal.

Rhabdomyomas are benign tumors of striated muscle. They are distinguished by topographic data: cardiac or genital and by histological criteria: foetal or adult type. The foetal type is the most heterogeneous, with either a majority of immature cells or a mixture of maturing elements. This diversity has led to distinguish immature (or standard) foetal Rhabdomyomas from intermediate foetal Rhabdomyomas. One observation of this last type is reported. The authors highlight the essential characteristics of foetal Rhabdomyomas, however the exact meaning remains unclear: an anomaly in the differentiation of the striated muscle? or a true tumoral process through genetic anomaly?

In-vitro development of corneal epithelial cells on a new hydrogel for epikeratoplasty.

This study demonstrates the adhesion and growth of bovine corneal epithelial cells on the surface of a new hydrogel. The hydrogel, containing 78% of water and 22% of AN-69 polymer (poly(acrylonitrile-sodium methallyle sulfonate)), was obtained by phase inversion of polymer-dimethylformamide solution in physiological saline (0.9% NaCl). Experiments were also carried out using hydrogel treated with arginine, human albumin and collagen IV. Covering of hydrogel samples by epithelial cells was completed within ten days, with good cell viability. The epithelial cells spread out and formed a consistent cell layer, confirmed by immunocytochemistry experiments against cytokeratins. Transmission electron micrographs showed numerous desmosomes between cells and the presence of some membrane differentiations at the cell/hydrogel interface. This study suggests therefore that the hydrogel might be suitable for the development of artificial epikeratoplasty grafts.

[Spinal tuberculosis. Study of clinical and radiological aspects from a series of 82 cases]. / La tuberculose vertébrale. Etude des aspects cliniques et radiologiques à partir d'une série de 82 cas.

We present a retrospective study of 82 cases of spinal tuberculosis diagnosed over the last 30 years. An increasing incidence of this disease not related to HIV infection has become apparent since 1992. 24% of patients were born outside continental France. The intradermal reaction was negative in 10% of patients. Discovertebral lesions detected in 93% of patients was the most frequent radiological presentation. Spondylitis with osteolysis or bone sclerosis at single or multiple levels was seen in the others. Tuberculous lesion of the posterior arch was associated in 10% of patients. In most cases CT scan showed a fragmentary vertebral destruction which was characteristic of the disease. MRI revealed the precise extent of the lesions into the spinal canal. Morphologic features suggestive of the tuberculous nature of paravertebral abcesses could be demonstrated when slices were performed in the axial or coronal plan. Tuberculous involvement of the spine is still a frequent disease. The main clinical and radiological findings are presented.

Peripheral pyogenic arthritis. A study of one hundred seventy-nine cases.

A retrospective medical record-based study of cases of peripheral pyogenic arthritis diagnosed in a rheumatology department between 1966 and 1993 was conducted. Of the 197 cases, 179 were evaluable. Pyogenic arthritis accounted for 0.68% of admissions and 30.3% of bone and joint infections during the study period. Incidence rose gradually from 2.2 new cases per year between 1966 and 1970 up to 6 to 10 new cases per year since 1991. In 88% of cases a single joint was involved, with the most commonly affected sites being the knee (32.5%), hip (22.2%), shoulder (12%) and sacroiliac joint (11.4%). Of the 22 patients with polyarticular arthritis, 19 had involvement of two joints. A portal of entry was identified in 53% of cases. Of the 13% of iatrogenic cases, half occurred after a local corticosteroid injection. The pathogen was identified in 65% of cases. Staphylococcus aureus was the most common organism (56%) followed by streptococci (9.5%) and E. coli (7%). Only three patients had gonococcal arthritis. Mean duration of therapy was four months. Although complications were exceedingly rare, three patients died and three others developed septic shock. Our data suggest that the presentation of pyogenic arthritis has remained essentially unchanged. In particular, we found no increase in iatrogenic forms, in contrast to recent experience with vertebral osteomyelitis.

Variations in the glycoforms of serum alpha 1-antichymotrypsin in liver diseases and after liver transplantation.

1. Using crossed immunoaffinity electrophoresis with free concanavalin A in the first dimension, we studied the microheterogeneity of alpha 1-antichymotrypsin due to various glycoforms in sera from patients with various liver diseases and after liver transplantation. 2. Studies by isoelectric focusing and immunoblotting and by crossed immunoelectrophoresis without concanavalin A in the first dimension allowed us to show that there is no dramatic variation in electrophoretic heterogeneity of alpha 1-antichymotrypsin in the serum of patients with liver diseases or after liver transplantation when compared with that of normal subjects. Therefore the heterogeneity observed in crossed immunoaffinity electrophoresis is due to various interactions with concanavalin A. 3. The results were expressed as the ratio of concanavalin A non-reactive glycoforms plus concanavalin A weakly reactive glycoforms to concanavalin A reactive glycoforms, called R alpha 1-ACT. R alpha 1-ACT was significantly higher in patients with cirrhosis (n = 53) when compared with normal subjects (n = 30). The median R alpha 1-ACT was 1 (range 0.72-1.25) in normal subjects. It was 1.6 (range 1.18-3.02), 1.45 (range 0.65-4.12) and 2.24 (range 1.03-19) in cirrhosis of Child's grade A, B and C, respectively. There was a dramatic decrease in glycoforms with mostly biantennary glycans in some patients with Child's grade C cirrhosis. Serum levels of alpha 1-antichymotrypsin were lower than normal only in some patients with Child's grade C cirrhosis. 4. Among the patients with acute viral hepatitis studied (n = 17), five were studied longitudinally.(ABSTRACT TRUNCATED AT 250 WORDS)