Isolation and characterization of liver-derived hepatitis B e antigen

Two subpopulations of hepatitis B e antigen (HBeAg) were isolated from a human liver infected with hepatitis B virus. HBeAg extracted from liver homogenate subsequent to treatment with buffered 3 M NaSCN or 0.5 M MgCl2 banded at the density of 1.13 g/cm3 in CsCl and was polydispersed on gel filtration. In contrast, HBeAg released with phosphate-buffered saline (PBS) was detected mainly at a density of 1.20 g/cm3 in a CsCl gradient and consisted of low molecular weight species on gel chromatography. Polypeptides of 40,000 and 45,000 daltons were found in NaSCN and PBS-released HBeAg preparations, respectively. The results are interpreted as suggestive that liver HBeAg is a dimer of the major core particle polypeptide in different physicochemical forms.     

Arterial vascularization of the human moderator band: an analysis of this structure's role as a collateral circulation route

In the human heart, the moderator band, or trabecula septomarginalis, is a muscle column that courses inferiorly from the right portion of the interventricular septum to the base of the anterior papillary muscle of the right ventricle This muscular structure is crossed by one or more arteries, which come from the anterior interventricular artery and perfuses the anterior papillary muscle of the right ventricle. In order to clarify the arterial supply of this muscle column, we studied 28 adult hearts, free of any signs of coronary disorder. The path of the moderator band artery was followed by means of microdissection, and we studied the source, course, and interconnections made with other arteries. We observed that the source of the moderator band artery lies in the first three anterior septal arteries, most often in the second one. In relation to the short axis of the heart, the artery of the moderator band can either follow a horizontal path to the septal papillary muscle of the right ventricle or an oblique route to the moderator band, depending on the position of its source. In all the hearts studied, the moderator band artery made anastomotic connections at the base of the anterior papillary muscle of the right ventricle with various branches of the right coronary artery, which means that it can play a key role in collateral circulation following obstruction of the epicardium coronary arteries.     

Mariner is defective in myosin VIIA: a zebrafish model for human hereditary deafness

The zebrafish (Danio rerio) possesses two mechanosensory organs believed to be homologous to each other: the inner ear, which is responsible for the senses of audition and equilibrium, and the lateral line organ, which is involved in the detection of water movements. Eight zebrafish circler or auditory/vestibular mutants appear to have defects specific to sensory hair cell function. The circler genes may therefore encode components of the mechanotransduction apparatus and/or be the orthologous counterparts of the genes underlying human hereditary deafness. In this report, we show that the phenotype of the circler mutant, mariner, is due to mutations in the gene encoding Myosin VIIA, an unconventional myosin which is expressed in sensory hair cells and is responsible for various types of hearing disorder in humans, namely Usher 1B syndrome, DFNB2 and DFNA11. Our analysis of the fine structure of hair bundles in the mariner mutants suggests that a missense mutation within the C-terminal FERM domain of the tail of Myosin VIIA has the potential to dissociate the two different functions of the protein in hair bundle integrity and apical endocytosis. Notably, mariner sensory hair cells display morphological and functional defects that are similar to those present in mouse shaker-1 hair cells which are defective in Myosin VIIA. Thus, this study demonstrates the striking conservation of the function of Myosin VIIA throughout vertebrate evolution and establishes mariner as the first fish model for human hereditary deafness.     

Mesothelial cyst of the adrenal gland

We report a case of a mesothelial adrenal cyst which was incidentally discovered in a 38-year old woman. The diagnosis was confirmed by an immunohistochemistry study. Adrenal cysts are rare. They occur more commonly in female patients during the 4th and 5th decades and are usually asymptomatic. Adrenal cysts are divided into four groups : parasitic, epithelial, endothelial cysts and pseudocysts. The management is still discussed : follow-up, surgical resection or fine-needle aspiration.     

Neural basis of visually guided head movements studied with fMRI

We used event-related fMRI to measure brain activity while subjects performed saccadic eye, head, and gaze movements to visually presented targets. Two distinct patterns of response were observed. One set of areas was equally active during eye, head, and gaze movements and consisted of the superior and inferior subdivisions of the frontal eye fields, the supplementary eye field, the intraparietal sulcus, the precuneus, area MT in the lateral occipital sulcus and subcortically in basal ganglia, thalamus, and the superior colliculus. These areas have been previously observed in functional imaging studies of human eye movements, suggesting that a common set of brain areas subserves both oculomotor and head movement control in humans, consistent with data from single-unit recording and microstimulation studies in nonhuman primates that have described overlapping eye- and head-movement representations in oculomotor control areas. A second set of areas was active during head and gaze movements but not during eye movements. This set of areas included the posterior part of the planum temporale and the cortex at the temporoparietal junction, known as the parieto-insular vestibular cortex (PIVC). Activity in PIVC has been observed during imaging studies of invasive vestibular stimulation, and we confirm its role in processing the vestibular cues accompanying natural head movements. Our findings demonstrate that fMRI can be used to study the neural basis of head movements and show that areas that control eye movements also control head movements. In addition, we provide the first evidence for brain activity associated with vestibular input produced by natural head movements as opposed to invasive caloric or galvanic vestibular stimulation.     

Protective effects of HN and F glycoprotein-specific monoclonal antibodies on experimental newcastle disease

Monoclonal antibodies directed against two different epitopes of HN protein of NDV Italien neutralised this virus in both in vitro and in vivo tests. Moreover, the combination of these two HN monoclonal antibodies neutralised the Italien virus synergistically. Five monoclonal antibodies directed against the F protein of NDV had variable neutralising activity against NDV Italien. Passive protection afforded by some anti F monoclonal antibodies was higher than that observed with the combination of the two HN monoclonal antibodies and even equivalent or better than that obtained with rabbit polyclonal antiserum. The importance of the F protein in the immune response against NDV is demonstrated.     

Screening of SLC26A4 (PDS) gene in Pendred's syndrome: a large spectrum of mutations in France and phenotypic heterogeneity

Sensorineural hearing defect and goiter are common features of Pendred's syndrome. The clinical diagnosis of Pendred's syndrome remains difficult because of the lack of sensitivity and specificity of the thyroid signs. The identification of PDS as the causative gene allowed molecular screening and enabled a re-evaluation of the syndrome to identify potential diagnostic characteristics. This report presents the clinical and genotypic findings of 30 French families, for whom a diagnosis of Pendred's syndrome had been made. Twenty-seven families had at least one mutated allele. Twenty-eight different mutations were identified, 11 of which had never been previously reported. The main clinical characteristics were: early hearing loss, fluctuation in terms of during deafness evolution, and the presence of an enlarged vestibular aqueduct.