Whole exome sequencing identifies new causative mutations in Tunisian families with non-syndromic deafness.

Identification of the causative mutations in patients affected by autosomal recessive non syndromic deafness (DFNB forms), is demanding due to genetic heterogeneity. After the exclusion of GJB2 mutations and other mutations previously reported in Tunisian deaf patients, we performed whole exome sequencing in patients affected with severe to profound deafness, from four unrelated consanguineous Tunisian families. Four biallelic non previously reported mutations were identified in three different genes: a nonsense mutation, c.

Doppler ultrasonography of peripheral vascular disease: the potential for ultrasound contrast agents.

Noninvasive diagnosis of peripheral vascular disease started with the introduction of Doppler technology. The development of high frequency ultrasound and color Doppler imaging allows continuous assessment of vascular disorders along the arterial tree. However, the technique remains operator dependent.

[Transcranial pulsed Doppler].

Transcranial Doppler ultrasonography is the only non invasive examination enabling the reliable measurement of the blood flow velocity in the intracranial arterial trunks. However, it cannot be constantly perfect. It is fully realized in about 10% of the patient.

Genetic restriction of murine hepatitis virus type 3 expression in liver and brain: comparative study in BALB/c and C3H mice by immunochemistry and hybridization in situ.

To study the host-dependent genetic variations in murine hepatitis virus type 3 (MHV 3) induced diseases, we localized the sites of MHV 3 (Mill Hill strain) expression within liver and brain by immunohistochemistry or hybridization in situ. Two strains of mice were studied: BALB/c mice, which develop an acute and lethal hepatitis and C3H mice which develop a chronic brain infection. In BALB/c mice, viral RNA and antigens appeared during the first 24h post infection (p.

Human immunodeficiency virus type 1-infected monocytic cells can destroy human neural cells after cell-to-cell adhesion.

Primary cultures of human embryonic neurons and astrocytes have been used to test the interactions between neural cells and either human immunodeficiency virus type 1 (HIV-1) or HIV-1-infected monocytes. After direct infection with HIV-1, neither morphological alteration of neurons and astrocytes nor signs of viral replication were observed. Similarly, cultured human neurons and astrocytes were resistant to incubation with the supernatant of HIV-1-infected U937 cells, a human monoblastoid cell line.

[Transcranial pulsed Doppler. Problems posed by the temporal window (834 patients)].

The absence of temporal windows represents an indisputable limitation of transcranial pulse Doppler (13% of 834 patients). We wanted to specify the elements causing this condition. The patient's age is a determinant factor, especially after 60 years of age.

[Encephalitis with viral replication. Clinical aspects, prognosis and treatment].

Encephalites with viral replication are due to multiplication of a virus within the central nervous system. Diagnosis and initial therapeutic decisions rest on simple clinical and paraclinical findings: age of the child, presence of high-grade fever, presence and localization of seizures, CSF characteristics, and EEG findings. Acyclovir is always indicated in a drowsy child with a high fever who has even a brief seizure and CSF abnormalities.

[Acute hydrocephalus due to Candida meningitis in a 2-month-old infant].

A case of triventricular acute hydrocephalus is reported in a 2 month-old male. The etiology was a Candida sepsis with neonatal onset and subacute course of meningitis and arthritis. No immune deficiency was detected and antibiotic treatment appeared to be the only predisposing factor to systemic candidiasis in this neonate.

[Popliteal vein entrapment, popliteal cyst, desmoid tumor and fabella syndrome].

The popliteal fossa is a relatively small, muscle-bound strategic anatomical area where is found, on the posterior aspect of the knee, a vasculonervous pedicle and where both vascular and pseudovascular disease may develop, the latter originating from wall-constituting parts. Among non-typical popliteal diseases, the authors have singled out four rare syndromes. The popliteal vein may be trapped due to fibrous strangulation or, more often, to compression by the hypertrophied gastrocnemius muscle.

[Transcranial Doppler: first results of exploration of the circle of Willis].

Over a two year period, 500 intracranial examinations were performed to explore the arteries at the base of the skull (middle, anterior and posterior cerebral) as well as the basilar artery. Exploration of the carotid siphons by the transorbital route is not systematic but used when approach to the vessels by the temporal windows is impossible. The transcranial Doppler examination is particularly indicated in the following circumstances: (1) In patients presenting a tight stenosis on the extracranial internal carotid artery (50 cases).

Effect of cyclosporin A on an experimental chronic viral infection of the central nervous system.

The effects of cyclosporin A (CsA) on neuropathological lesions induced by a chronic viral infection have been tested in the experimental model of the mouse hepatitis virus 3 (MHV3) infection. Daily injections of CsA (50 mg/kg) inhibited the expression of the MHV3-induced ependymitis, meningitis, hydrocephalus and vasculitis. The effect was preserved even if CsA treatment was initiated 15 days after virus infection but was lost if CsA treatment was given later on or for a shorter period of time.

[Transcranial Doppler pulse. Methodology, diagnostic value and limitations].

Vessels of base of skull were inaccessible to conventional ultrasonic image until 1982, when the use of pulsed Doppler emitting a beam of 2 MHz coupled with a frequency analyzer allowed direct exploration of terminal branches of the internal carotid artery (ICA) and the basilar trunk. It is now possible to measure rate of flow in middle cerebral artery (MCA), anterior (ACA) and posterior (PCA) cerebral arteries, communicating arteries and those of basilar trunk. Practical applications of this new method are numerous in cerebrovascular disease: diagnosis of brain stem lesions, evaluation of effects of extracranial lesions, detection and follow up of arteriovenous malformations, functional value of the circle of Willis prior to carotid surgery.

[Ultrasonic tomography in the study of supra-aortic trunks].

Real time mode B echotomography completes ultrasound exploration of supra-aortic trunks. Continuous Doppler recording is essential for detection of vessels and identification of significant lesions. However, it cannot detect arterial wall lesions that have no effect on arterial blood flow but can be at the origin of migrating emboli.

Selective tropism of a neurotropic coronavirus for ependymal cells, neurons, and meningeal cells.

The ability of a neurotropic virus, mouse hepatitis virus type 3 (MHV3), to invade the central nervous system (CNS) and to recognize cells selectively within the brain was investigated in vivo and in vitro. In vivo, MHV3 induced in C3H mice a genetically controlled infection of meningeal cells, ependymal cells, and neurons. In vitro, purified MHV3 bound to the surface of isolated ependymal cells and cultured cortical neurons but not to oligodendrocytes or cultured astrocytes.

Neurotransmitter changes during development of cortical neuronal cultures.

Benzodiazepine (BDZ) ligands clonazepam (CLO) and Ro5-4864 which preferentially bind to neuronal and non-neuronal elements, respectively, have been used to follow neuronal and non-neuronal development in fetal murine cortical cultures. CLO-displaceable BDZ binding, choline acetyltransferase (CAT) activity, high-affinity delta-aminobutyric acid (GABA) uptake, and glutamic acid decarboxylase (GAD) activity reached a maximum value at the end of the second week in culture reflecting maximum neuronal maturation and development. There is a developmental order of these four functions: CAT activity (main enzyme in the synthesis of acetylcholine, a stimulating neurotransmitter) reached maximal levels first, 3H-GABA uptake and CLO-displaceable flunitrazepam receptor binding reached maximal levels 1 day later, and 4 days later GAD activity (primary enzyme in the synthesis of GABA, an inhibitor neurotransmitter) reached maximal levels.

Ultrasonography of supra-aortic trunks.

Ultrasonography by the Doppler technique combined with B-mode echotomography are useful methods in the investigation of disease of the major arteries in the neck supplying the brain. The investigations are described together with the significance of major findings.

[Acute hemiplegia complicating Kawasaki disease].

An infarct in the left middle cerebral artery territory in a 9 months old girl occurred in the course of Kawasaki's disease which in addition had induced a coronary aneurysm and a myocardial infarct. Embolism from the myocardial infarct was likely to have provoked the cerebral infarction. Neurological symptoms and signs are unusual in Kawasaki's disease.

[Malignant phenylketonuria caused by biopterin synthetase deficiency. Study of neuromediator catabolites in the cerebrospinal fluid during treatment].

In a child presenting with malignant phenylketonuria due to dihydrobiopterin synthetase deficiency, the authors studied the cerebrospinal fluid (CSF) homovanillic acid and 5 hydroxyindole acetic acid levels under different circumstances: without treatment; under a treatment with tetrahydrobiopterin used alone at various doses; under a treatment associating BH4, L-dopa, 5 hydroxytryptophan and carbidopa, with increasing doses and varying administration schedules. This biological study compared with clinical evolution, shows clearly the inefficacy, regardless of the doses, of BH4 on the CSF levels of neuromediators and on the neurological status, and the excellent efficacy of neuromediator precursors provided high doses are given, divided in the nyctohemeral period.

[Monoarthritis with positive Yersinia pseudotuberculosis serology in an 18-month-old girl].

A case of Yersinia pseudo-tuberculosis arthritis is reported in a 18 month-old girl. The authors emphasize the rarity of such cases, the value of testing for Yersinia antibodies in cases with arthritis of unknown origin and the uncertain long-term outcome.