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Biomedical subjects

N Sellier

Publications and source records attributed to N Sellier.

At least 37 records · Page 2Linked to original sources

Aortitis with antiphospholipid antibodies: CT and MR findings.

Two cases of aortitis associated with the presence of antiphospholipid antibodies (APAs) are reported. Only CT and MR imaging were able to show these unusual form of aortitis preferentially affecting the outer aortic tunics. We conclude that aortitis could be a new manifestation of primary antiphospholipid syndrome (APS) and the initial pathological process before the development of aortic thrombosis, reported as a classical complication of APS.

Aged↗

Metabolism of a 5-nitroimidazole in susceptible and resistant isogenic strains of Bacteroides fragilis.

We investigated the metabolism of dimetridazole (1,2-dimethyl-5-nitroimidazole) (DMZ) by the resting cell method in a susceptible strain of Bacteroides fragilis and in the same strain containing the nimA gene, which conferred resistance to 5-nitroimidazole drugs. In both cases, under strict anaerobic conditions DMZ was metabolized without major ring cleavage or nitrate formation. However, one of two distinct metabolic pathways is involved, depending on the susceptibility of the strain. In the susceptible strain, the classical reduction pathway of nitroaromatic compounds is followed at least as far as the nitroso-radical anion, with further formation of the azo-dimer: 5,5'-azobis-(1,2-dimethylimidazole). In the resistant strain, DMZ is reduced to the amine derivative, namely, 5-amino-1,2-dimethylimidazole, preventing the formation of the toxic form of the drug. The specificity of the six-electron reduction of the nitro group, which is restricted to 4- and 5-nitroimidazole, suggests an enzymatic reaction. We thus conclude that nimA and related genes may encode a 5-nitroimidazole reductase.

Anti-Bacterial Agents↗

Purification and characterization of deep sea shark Centrophorus squamosus liver oil 1-O-alkylglycerol ether lipids.

The 1-O-alkylglycerol composition of the liver oil of the deep sea shark Centrophorus squamosus, a species which provides edible flesh, has been determined. After various fractionations of the oil, the unsaponifiable fraction was characterized by means of gas chromatography/mass spectrometry, electron impact, and positive-ion chemical ionization. The oil is composed of 60% unsaponifiable matter, containing 45% squalene, 4.5% cholesterol, and 10% of linear saturated and monounsaturated glycerol ethers with 14-18 carbon atoms. After a first separation by chromatography on silicic acid, monounsaturated glycerol ethers have been separated from the saturated homologues, in particular from 1-O-octadecylglycerol (batyl alcohol) and 1-O-hexadecylglycerol (chimyl alcohol), via urea complexation. This newer application of the urea method, already used in the past to extract saturated from polyunsaturated fatty acids, allowed the purification of the main components of the complex unsaturated glycerol ether fraction, namely, 1-O-octadecen-9'ylglycerol (selachyl alcohol) and 1-O-hexadecen-9'ylglycerol.

Animals↗

Characterization of apolipoproteins B-100, AI and C from plasma lipoprotein in the goose, Anser anser. Evidence for a genetic polymorphism in ApoC-like apolipoproteins.

In this study we have characterized four of the principle goose apolipoproteins and compared their physicochemical properties with human and avian counterparts. Goose ApoB-100 and ApoAI amino acid compositions were very similar to their chicken and human homologous proteins. The partial N-terminal sequence from goose ApoAI was 91% and 82% similar to the corresponding duck and chicken proteins, respectively. Most of the observed amino acid changes detected between the ApoAI sequences were amino acid replacements having the same characteristics and could be the result of a single base mutation. The N-terminal portion of two ApoC-like apolipoproteins were also studied. Goose ApoCa had an electrophoretic mobility of 0.31 and exhibited a nine-residue motif that was well conserved between ApoCIII sequences from different species. We therefore suggest that ApoCa is the equivalent of mammalian ApoCIII. The N-terminal portion of goose ApoCb, the second major ApoC in high-density apolipoprotein, showed no similarity to proteins previously described in the literature. This protein displayed two isomorphs in alkaline urea gel electrophoresis called ApoCb1 and ApoCb2 with Rf values of 0.36 and 0.39, respectively. A genetic polymorphism was detected in the population whereby 25% of the animals carried only one isomorph and 50% exhibited both ApoCb isomorphs. These frequencies were similar in females and males. The transmission mode of these ApoCb isomorphs was consistent with two segregating alleles from a single codominantly expressed gene.

Amino Acid Sequence↗

Effects of an LH-RH agonist on reproductive responses and endocrinological parameters in landais ganders.

Semen quantitative (sperm production) and qualitative parameters (percentage of live and normal spermatozoa, sperm motility, egg fertility and hatchability), as well as hormonal parameters (LH and testosterone plasma concentrations) were compared for landais ganders, which were treated or not, with an LH-RH agonist prior to being sexually active. Treatment with the LH-RH agonist at this physiological stage delayed the onset of sperm production in some of the treated males. Although, comparable data were obtained during the first half of the reproductive period, treatment with the LH-RH agonist maintained sperm output at higher levels during its second half. Although the percentage of normal and live spermatozoa, sperm motility and true hatchability did not differ, the LH-RH agonist treatment had a positive effect on gosling production because of the higher fertility of the treated birds during the second part of the reproductive period. Treatment induced a large short-term decrease in testosterone levels followed by a rebound, leading to higher levels during the second half of the reproductive period. We conclude that treatment of ganders with an LH-RH agonist partially prevented the naturally occurring decline in sperm production and induced an increase in the rate of fertility rates during the second half of the productive period.

Journal Article↗

[Preoperative diagnosis of xanthogranulomatous cholecystitis].

Xanthogranulomatous cholecystitis (XGC) is a benign chronic inflammation of the gallbladder, rarely described in the radiologic literature. Like xanthogranulomatous pyelonephritis, it can clinically and radiologically mimic carcinoma. This unusual entity is characterized morphologically by a broad spectrum of xanthogranulomatous changes seen from a small limited focus within yellow nodule in the gallbladder wall, to diffuse involvement of the entire gallbladder with extension of the fibrosis into surrounding tissues. It is clear that recurrent inflammation and calculi are important for the pathogenesis, which is not well understood. The clinical presentation and radiologic findings of XGC are non specific. Irregular thickening of the gallbladder wall and local extension of the process can mimic carcinoma. Diagnosis of XGC is always established by histological examination, characterized by the infiltration of round cells, lipid laden histocytes and multinucleated giant cells in the muscle layer. We report a case of 76-year-old woman who had an episode of epigastric and right upper quadrant pain, 4 months before admission. Physical examination demonstrated a palpable mass in gallbladder region. Echography and computed tomography showed a large gallbladder, a thickened wall and an infiltration of the adjacent liver. The relatively well defined gallbladder internal border and the absence of biliary tract's dilatation allowed us to suggest the diagnosis of XGC, which was confirmed intraoperatively by frozen section histology. Once the diagnosis was established, cholecystectomy was performed. Occasionally, the inflammatory reaction is so severe that a subtotal cholecystectomy is required. Postoperative recovery was, as usually, uneventful. Although a rare entity, XGC should be considered in the differential diagnosis of complex right upper quadrant masses, as well as neoplastic gallbladder disease.

Aged↗

The Wiedemann-Rautenstrauch neonatal progeroid syndrome: a case report and review of the literature.

We present the case of a post-term newborn with intrauterine growth retardation, pseudohydrocephalus, a tiny face and mouth, thin wrinkled skin, an aged appearance, lipoatrophy and a normal cranial CT scan, suggestive of the Wiedemann-Rautenstrauch neonatal progeroid syndrome. He developed hypothyroidism on day 18 due to a partial organification disorder as did a later born sib. His mental development remains normal at age 2 with delayed growth at -2.5 SD. The case is presented and discussed and the literature is reviewed.

Fetal Growth Retardation↗

Opercular malformations: clinical and MRI features in 11 children.

Opercular malformations are rare and complex brain malformations for which only very fragmented neuropathological descriptions have been reported. They are related to an abnormal development of both sylvian fissure and frontoparietal operculum. We report a retrospective clinical and MRI study of 11 patients presenting with opercular malformations. A congenital pseudobulbar syndrome was observed in six cases, various motor disorders in seven cases, mental retardation in six cases and epilepsy in four cases. The purpose of this study is to evaluate the main features of opercular malformations in children and to try to characterise this entity on the basis of its clinical features and MRI pattern.

Cerebral Cortex↗

Influence of orotic acid and estrogen on hepatic lipid storage and secretion in the goose susceptible to liver steatosis.

Fatty liver in the goose results from an increased hepatic lipogenesis in response to overfeeding, together with a deficient secretion of triacylglycerol as very-low-density lipoproteins (VLDL). Orotic acid and estrogen, which both modify lipid metabolism in the liver, were used in male geese as tools to understand the alterations of liver lipids and plasma lipoproteins during the induction of liver steatosis. Liver lipids were analyzed after solvent extraction and plasma lipoproteins after separation by density gradient ultracentrifugation. Contrary to what is known in the rat, orotic acid (1% in food for 2 weeks) failed to induce liver steatosis. In force-fed geese, liver weight increased from approximately 100 g to approximately 800 g in 2 weeks, as a consequence of a specific accumulation of triacylglycerol. In both groups, VLDL contained less triacylglycerol (35%) than normal. Such an uncoupling of triacylglycerol synthesis and secretion, of which the precise reason is still unknown, may facilitate their accumulation when force-feeding increases hepatic lipogenesis. As with force-feeding, triacylglycerol synthesis was enhanced by estrogen, but their secretion as VLDL was very efficient and prevented liver steatosis almost completely. Since HDL concentrations were considerably decreased by estrogen, VLDL were the main lipoprotein species, with 48 g/l and 62% triacylglycerol. Where estrogen-treated geese were force-fed concomitantly, VLDL concentration was even higher (62 g/l), but triacylglycerol secretion could not prevent liver steatosis (liver weight 640 g). The data are discussed in relation to in vitro studies showing that channelling of triacylglycerol towards secretion as VLDL or hepatic storage depends on their residence time in the different intracellular compartments.

Animal Feed↗

[Responses of medical imaging in battered children. The Silverman-Ambroise Tardieu syndrome].

Imaging procedures offer an important contribution to the syndrome of the abused child that F.N. Silverman himself proposes to call the Ambroise Tardieu syndrome. First they disclose and analyse the lesions which may involve bones, encephalon or spinal cord, viscera, soft tissues. Then they must answer four questions: Traumatic lesion or normal variant? If traumatic, are there arguments pointing to abuse, for instance multiple bone lesions of different ages and more specifically fractures of ribs, clavicle, spine, pelvis, phalanxes? Is there a possibility of a general disease explaining such traumatic lesions? Etiologies are revised including sensibility deficits. Finally are the bad treatments inflicted with an intention of hurting, injuring or destroying? The answer results of a discussion with clinicians and social interveners but some lesions, as phalanx fractures, may be determining. In this situation that involves the vital prognosis and may induce severe sequellae the imaging strategy, fully described, is of paramount importance.

Battered Child Syndrome↗

[Ultrasonography of the hip in infants].

Ultrasonography of the hip in high risk newborns is the natural extension of clinical examination to the diagnosis of congenital dislocation and dysplasia of the hip. At the end of the first month, ultrasonography allows a better adjustment of therapeutic to the orthopaedic status.

Hip Dislocation, Congenital↗

Plasma lipoproteins and liver lipids in two breeds of geese with different susceptibility to hepatic steatosis: changes induced by development and force-feeding.

Susceptibility to fatty liver in the force-fed goose is partly under genetic control. However, the mechanisms leading to liver steatosis in this avian model are poorly understood, but may involve perturbation in hepatic lipoprotein synthesis. Plasma lipoproteins were fractionated by density gradient ultracentrifugation from plasma of geese differing in their susceptibility to liver steatosis (Landes breed, highly susceptible; Rhine breed, partly resistant). The concentrations and chemical compositions of the major lipoprotein classes (VLDL, IDL, LDL and HDL) were characterized at 8, 22 and 27 wk of age and compared to the lipid composition of the corresponding liver. In non-force-fed geese, the lipoprotein profile was typical of birds, with high-density lipoprotein (HDL) predominating (4-5 g/L). However, at 22 and 27 wk of age, very low-density lipoprotein (VLDL) levels were significantly lower in Landes geese suggesting that this breed may possess a lower ability to export liver lipids, which would explain its susceptibility to liver steatosis when overfed. The livers of force-fed geese were specifically enriched in triglyceride, and to a lesser extent, in cholesteryl esters and non-esterified fatty acids as compared to those of control geese of the same age (27 wk). This accumulation of lipids was more pronounced in the Landes breed and was responsible for the higher liver weight in that breed. In both breeds, liver steatosis was accompanied by an increase in plasma levels of HDL (11 g/L), whereas low-density lipoproteins were essentially absent.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

Gas chromatographic-mass spectral studies after methylation of metabolites produced by some anaerobic bacteria in spent media.

The gas chromatographic analysis of metabolites such as volatile fatty acids (VFAs) and non-volatile fatty acids (NVFAs) for identification of anaerobic bacteria is now widely performed. Cultures of anaerobes tested for NVFAs as methyl esters were found to contain several unidentified compounds not previously detected and/or reported with methylation procedures. Gas chromatographic-mass spectrometric studies demonstrated that these compounds correspond to the methyl esters of both saturated and unsaturated short-chain fatty acids, and also of 2-hydroxy and 2-oxo acids. The distribution of these acids among different species of anaerobes was determined and their amounts were measured. The effects of supplementing the culture medium with either glucose or amino acids on the production of these acids are described. The use of very polar stationary phases is suggested for a better separation of all NVFAs.

Bacteria, Anaerobic↗

Value of systematic post mortem radiographic examinations of fetuses--400 cases.

A retrospective study of 400 cases of fetal deaths has been carried out to assess the value of systematic post mortem radiological examination. Apart from general diagnosis purpose, special attention was given to the assessment of bone age and mineralization. The results were correlated with the clinical, U.S., chromosomal and pathological data. Computerized analysis of our information show the following results: (1) The radiological examination was valuable for the final diagnosis in 13.5% of cases. (2) It brings additional information in 34.5% of cases. (3) It had no diagnostic value in 52%. Furthermore, several points deserve attention such as apparition of teeth (21 weeks), calcaneum (24 weeks). Major osteoporosis was always associated with a constitutional bone disease or an infectious process. An excessive length of the upper limbs (12) was seen in 11 cases of anencephaly. We suggest that a radiological examination should not be routinely performed, when the diagnosis is otherwise obvious, but should be considered in the presence of dwarfism, or other limb abnormalities and when the gestational age is uncertain. The films provide essential information especially for further genetic counselling. Systematic post mortem radiographic examinations are performed in all naturally aborted fetuses over 11 weeks of gestation in our institution. A retrospective study of the last 400 cases was designed in order to assess the value of this examination, with regard to overall diagnosis and assessment of bone maturation and mineralisation.

Bone Diseases, Developmental↗