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Biomedical subjects

J Laurent

Publications and source records attributed to J Laurent.

At least 19 recordsLinked to original sources

[Hereditary angioneurotic edema: a case report in a 3-year-old child].

Hereditary angioneurotic edema is a dominant autosomal disease (incidence 1/150,000), whose diagnosis is crucial as this condition can lead to fatal asphyxia within minutes. We report the case of a three-year-old girl, misdiagnosed as allergic asthma. Recognition of the syndrome led to adapted care restoring normal family and school life. Pathogenic cascades involved and therapeutic principles of this disease are reviewed.

Adrenergic Agonists↗

Long-chain 3-hydroxyacylCoA dehydrogenase deficiency: a new case presenting with liver dysfunction, cholestasis and fibrosis.

UNLABELLED: A cholestatic 6-mo-old girl was admitted to our department because she recently presented with hypotonia and lethargy, apparently due to moderate and transient hypoglycaemia. Her urine contained 3-hydroxy-dicarboxylic acids of 12 to 14 carbons in length and her plasma acylcarnitine profile was consistent with long-chain 3-hydroxyacylCoA dehydrogenase deficiency. This diagnosis was confirmed by enzyme studies. This deficiency was due to a G1528C mutation on the paternal allele (mutation on the maternal allele as yet not identified). The patient improved dramatically with medium-chain triglyceride supplementation. CONCLUSION: Early cholestasis and hepatic fibrosis must lead to search for long-chain 3-hydroxyacylCoA dehydrogenase deficiency, particularly when hypoketotic hypoglycaemia is present.

Acyl-CoA Dehydrogenase, Long-Chain↗

An examination of the tripartite model of anxiety and depression and its application to youth.

The ability to differentiate anxiety and depression has been a topic of discussion in the adult and youth literatures for several decades. The tripartite model of anxiety and depression proposed by L. A. Clark and D. Watson (1991) has helped focus the discussion. In the tripartite model, anxiety is characterized by elevated levels of physiological hyperarousal (PH), depression is characterized by low levels of positive affect (PA), and negative affect (NA) or generalized emotional distress is common to both. The advent of the model led to the development of measures of tripartite constructs and subsequent validity studies. The tripartite model and resultant activity concerning the model was largely devoted to adult samples. However. those interested in anxiety and depression among youth are now incorporating the tripartite model in their work. This paper examines the current influence of the tripartite model in the youth literature, especially with regard to measuring anxiety and depression.

Adolescent↗

A randomized comparison of four omeprazole-based triple therapy regimens for the eradication of Helicobacter pylori in patients with non-ulcer dyspepsia.

BACKGROUND: Helicobacter pylori eradication rates in France after therapy with omeprazole, amoxicillin and clarithromycin are among the lowest in Europe. This study evaluated alternative eradication regimens. METHODS: Helicobacter pylori-positive patients (n=323) with non-ulcer dyspepsia were randomized to receive one of four 1-week regimens consisting of omeprazole, 20 mg b.d., plus either: amoxicillin, 1000 mg b.d., and clarithromycin, 500 mg b.d. (OAC); bacampicillin, 1200 mg b.d., and clarithromycin, 500 mg b.d. (OBC); clarithromycin, 250 mg b.d., and metronidazole, 500 mg b.d. (OCM); or amoxicillin, 1000 mg b.d, and azithromycin, 500 mg on day 1 and 250 mg on days 2-5 (OAAz). Eradication was confirmed by urea breath test 4-6 weeks after treatment. Susceptibility testing was performed in the case of eradication failure. RESULTS: The eradication rate with OAAz was 38% (95% CI, 25.6-49.4) on intention-to-treat analysis, which was lower (P < 0.05) than with the other regimens [OCM, 61% (50.0-72.8); OBC, 65% (54.0-76.5); OAC, 72% (61.8-81.8)]. Of the strains isolated following treatment failure with OAC, OBC or OCM, 84% were clarithromycin resistant. CONCLUSIONS: OAC remains the reference treatment for H. pylori eradication in France, although bacampicillin offers a useful alternative to amoxicillin. Susceptibility testing should be considered after unsuccessful eradication therapy.

Administration, Oral↗

A broad spectrum of clinical presentations in congenital disorders of glycosylation I: a series of 26 cases.

INTRODUCTION: Congenital disorders of glycosylation (CDG), or carbohydrate deficient glycoprotein syndromes, form a new group of multisystem disorders characterised by defective glycoprotein biosynthesis, ascribed to various biochemical mechanisms. METHODS: We report the clinical, biological, and molecular analysis of 26 CDG I patients, including 20 CDG Ia, two CDG Ib, one CDG Ic, and three CDG Ix, detected by western blotting and isoelectric focusing of serum transferrin. RESULTS: Based on the clinical features, CDG Ia could be split into two subtypes: a neurological form with psychomotor retardation, strabismus, cerebellar hypoplasia, and retinitis pigmentosa (n=11), and a multivisceral form with neurological and extraneurological manifestations including liver, cardiac, renal, or gastrointestinal involvement (n=9). Interestingly, dysmorphic features, inverted nipples, cerebellar hypoplasia, and abnormal subcutaneous fat distribution were not consistently observed in CDG Ia. By contrast, the two CDG Ib patients had severe liver disease, enteropathy, and hyperinsulinaemic hypoglycaemia but no neurological involvement. Finally, the CDG Ic patient and one of the CDG Ix patients had psychomotor retardation and seizures. The other CDG Ix patients had severe proximal tubulopathy, bilateral cataract, and white matter abnormalities (one patient), or multiorgan failure and multiple birth defects (one patient). CONCLUSIONS: Owing to the remarkable clinical variability of CDG, this novel disease probably remains largely underdiagnosed. The successful treatment of CDG Ib patients with oral mannose emphasises the paramount importance of early diagnosis of PMI deficiency.

Adipose Tissue↗

Cross-cultural examination of the tripartite model with children: data from the Barretstown studies.

The Positive and Negative Affect Scale for Children (PANAS-C) and the Physiological Hyperarousal Scale for Children (PH-C) were administered to a group of 240 children from European countries to determine their utility in examining the tripartite model of anxiety and depression in a cross-cultural sample. Most of the children (n = 196) had been diagnosed with a medical illness; the remainder were siblings of these youngsters (n = 44). Only slight variations were noted in items between this sample and samples from the United States. Despite these minor differences, 3 distinct scales measuring the positive affect, negative affect, and physiological hyperarousal constructs of the tripartite model were identified. These findings illustrate that the PH-PANAS-C provides a useful measure of the tripartite model in a cross-cultural sample of youth. The findings also demonstrate that the tripartite model is generalizable to a cross-cultural milieu.

Adolescent↗

Joint factor analysis of the Children's Depression Inventory and the Revised Children's Manifest Anxiety Scale.

Used a joint factor analysis with the Children's Depression Inventory (CDI; Kovacs, 1980/81, 1992) and Revised Children's Manifest Anxiety Scale (RCMAS; C. R. Reynolds & Richmond, 1978, 1985) to identify items that uniquely measured depression and anxiety. Data from 750 youngsters in Grades 4 through 7 were analyzed using principal-axis factoring with an oblique rotation. Salient factors were identified using guidelines provide by Gorsuch (1997). Item overlap and the large negative affectivity component across instruments were evident. Items that overlapped or had nonsalient loadings were eliminated. The sample was randomly split into 2 groups of 375 and analyses were repeated. Results indicated that a unique 9-item depression factor composed largely of items representing a negative view of oneself existed. In addition, a unique 7-item anxiety factor emerged that consisted of items reflecting worry. The validity of these abbreviated scales was explored using a separate sample of 131 students in Grades 4 through 9. The abbreviated scales were correlated with scales of positive and negative affect consistent with predictions. Findings suggest exploring alternative scoring strategies for the CDI and RCMAS to eliminate problems associated with overlapping items.

Adolescent↗

Early-branching or fast-evolving eukaryotes? An answer based on slowly evolving positions.

The current paradigm of eukaryotic evolution is based primarily on comparative analysis of ribosomal RNA sequences. It shows several early-emerging lineages, mostly amitochondriate, which might be living relics of a progressive assembly of the eukaryotic cell. However, the analysis of slow-evolving positions, carried out with the newly developed slow-fast method, reveals that these lineages are, in terms of nucleotide substitution, fast-evolving ones, misplaced at the base of the tree by a long branch attraction artefact. Since the fast-evolving groups are not always the same, depending on which macromolecule is used as a marker, this explains most of the observed incongruent phylogenies. The current paradigm of eukaryotic evolution thus has to be seriously re-examined as the eukaryotic phylogeny is presently best summarized by a multifurcation. This is consistent with the Big Bang hypothesis that all extant eukaryotic lineages are the result of multiple cladogeneses within a relatively brief period, although insufficiency of data is also a possible explanation for the lack of resolution. For further resolution, rare evolutionary events such as shared insertions and/or deletions or gene fusions might be helpful.

Actins↗

JLP5B9: new monoclonal antibody against polysialylated neural cell adhesion molecule is of value in phenotyping lung cancer.

Non-small-cell lung cancer (NSCLC) is currently one of the most prevalent malignant tumors. It displays a wide variety of phenotypes which includes neuroendocrine markers commonly found on small-cell lung cancers (SCLC) such as the neural cell adhesion molecule (NCAM) and in particular its highly polysialylated isoform, embryonic NCAM (eNCAM). NSCLC with neuroendocrine differentiation may represent a subset of tumors whose cells have a more aggressive biological behavior. A tumor marker that distinguishes this latter sub-type could be of clinical relevance. Accordingly, we have raised a monoclonal antibody of the IgM type (JLP5B9) directed against capsular polysaccharides of N. meningitidis B which bears polysialic acid groups. We have demonstrated that JLP5B9 recognizes eNCAM with high affinity and that it is specifically directed against the polysialic acid moieties of NCAM. JLP5B9 was also found to react with human SCLC, NSCLC and neuroblastoma cell lines. We then used JLP5B9 as a specific probe for the detection of tissue eNCAM and found that it was expressed on up to 20% of tumor cells obtained from 5 out of 13 patients with NSCLC. This mAb deserves further investigation to evaluate its potential as a tool for serodiagnosis of lung cancer.

Adult↗

Il-4 and IFN-gamma mRNA induction in human peripheral lymphocytes specific for beta-lactam antibiotics in immediate or delayed hypersensitivity reactions.

Beta-lactam antibiotics elicit CD4+ and CD8+ T-cell-mediated immune responses that play a central role in allergic reactions. However, the involvement of a type 1- (Th1 or Tc1) or a type 2-like (Th2 or Tc2) differentiation in drug allergy remains unclear. We investigated the expression of interleukin 4 (IL-4) and interferon gamma (IFN-gamma) mRNA by quantitative reverse transcription and polymerase chain reaction (RT-PCR) in patient-derived peripheral blood lymphocytes following specific in vitro stimulation. Samples were collected from a total of 19 patients who had developed immediate or delayed clinical manifestations of hypersensitivity to beta-lactam and from 11 control subjects. Peripheral blood mononuclear cells (PBMCs) were stimulated with either free antibiotics or antibiotic-human serum albumin (HSA) conjugates. Specific induction of IFN-gamma mRNA expression was observed in 11 of 11 allergic patients with immediate reactions, in 6 of 8 patients with delayed reactions, and in 4 of 11 control subjects. IL-4 mRNA expression was induced in 5 of 11 allergic individuals with immediate reactions but in none of the 8 patients with delayed responses and none of the 11 control subjects. IL-4 mRNA expression was only induced following activation with free drugs, while IFN-gamma mRNA expression was predominantly induced in CD4+ T cells following stimulation with HSA-conjugated drugs. Immediate-type hypersensitivity to beta-lactams was not associated with a pure type 2-like response when PBMCs were specifically stimulated in vitro: Some patients with well-documented history of beta-lactam-induced immediate allergic reaction showed a high IFN-gamma response. Contact dermatitis involved Tc1 and Th1 cells and other delayed hypersensitivity reactions to beta-lactams were restricted to Th1 responses.

Adolescent↗

Prospective multicenter study comparing a standard reusable sphincterotome with a disposable triple-lumen sphincterotome.

BACKGROUND: Few data are available on the comparative performance of different types of sphincterotome. The aim of this study was to compare the efficacy of endoscopic sphincterotomy performed with either a reusable, single-lumen sphincterotome or a disposable triple-lumen instrument. METHODS: Seventy-seven consecutive adults requiring endoscopic sphincterotomy were prospectively and randomly assigned treatment with either a standard reusable single-lumen sphincterotome (group A, n = 38) or a disposable triple-lumen sphincterotome with a guidewire (group B, n = 39). The success rate, complications, and cost of the procedure per patient were compared. RESULTS: Deep cannulation was successful in 87% of cases in each group and sphincterotomy was achieved in 76% and 84% of cases in group A and B, respectively (NS). In the endoscopists' opinion the two instruments performed almost equally well. Twelve procedure-related complications occurred: 5 (all hemorrhages) in group A and 7 (1 hemorrhage, 4 cases of pancreatitis and 2 of cholangitis) in group B (NS). Eight reusable sphincterotomes were used with a cost of $61 per patient, compared with 39 disposable sphincterotomes with a cost of $241 per patient (p = 0.02). CONCLUSIONS: A standard reusable sphincterotome is satisfactory for most endoscopic sphincterotomies, and yields a substantial cost savings without compromising the success or safety of the procedure.

Aged↗

Ethics committee recommendations for laboratory animals in private research in France.

Complementary to existing legislation, non-public research companies in France have been working together voluntarily within an organization known as Grice (Interprofessional Working Group on Ethics Committees for Laboratory Animals/Groupe de Réflexion Interprofessionnel sur les Comites d'Ethique appliquée à l'animal de laboratoire) with the objective of creating institutional ethics committees in an effort to promote animal welfare and good scientific procedures. Each company's commitment to the creation of these committees has been expressed by signing the Charter. Each ethics committee is composed of at least three members, including one who is not a scientist; a veterinarian is highly desirable. The committee examines all procedures and protocols involving animals and hands down a favourable or unfavourable opinion, or requests improvements, especially concerning animal well-being. Consensual approval of the protocol is an essential requirement before the purchase or allocation of animals. The committee examines every aspect of laboratory animal housing and care, and inspects all temporary or permanent animal housing facilities. Grice will continue its efforts in relation with public research organizations as well as with groups and in other countries whose objectives are in line with its own.

Animal Welfare↗

Biochemical analysis of the interaction between elongation factor 1alpha and alpha/beta-tubulins from a ciliate, Tetrahymena pyriformis.

The interaction between elongation factor 1alpha (EF-1alpha) and alpha/beta-tubulins has been analyzed in vivo and in vitro. An association of both alpha- and beta-tubulins with EF-1alpha in the lysate of Tetrahymena pyriformis was detected by co-immunoprecipitation analysis. In contrast, in vitro biomolecular interaction analysis with glutathione S-transferase (GST) fusion proteins revealed that GST-beta-tubulin, but not GST-alpha-tubulin, can bind to GST-EF-1alpha. Two beta-tubulin binding sites have been identified to reside in the domains I and III of EF-1alpha. In addition, beta-tubulin itself seems to have two distinct interaction sites for each of the domains. Since domain II of EF-1alpha did not interact with beta-tubulin, we have re-evaluated the phylogenetic status of ciliates using EF-1alpha sequences devoid of domain II. The phylogenetic tree thus obtained was significantly different from that inferred from the whole sequence of EF-1alpha, suggesting the presence of functional constraints on the molecular evolution of EF-1alpha.

Animals↗

Liver transplantation in urea cycle disorders.

We report here our experience in the long-term management of 28 patients with citrullinaemia, 13 patients with carbamoyl phosphate synthase deficiency and 15 patients with argininosuccinic aciduria. In addition, we report a national French survey of 119 patients with ornithine transcarbamylase (OTC) deficiency enzymatically characterized in our laboratory. We also include in this report four personal patients (two with OTC and two with citrullinaemia) who were liver transplanted, and one OTC patient from the National French survey. Although this retrospective series is not really representative of the modern treatment combining low protein diet and arginine, sodium benzoate and sodium phenylbutyrate, it is obvious that the long-term outcome of all urea cycle disorders remains very guarded. We highlight the severity of the neonatal forms of such disorders, and mostly for OTC-deficient males. According to this evidence, our policy is not to treat such severely affected patients in the neonatal period who die anyway spontaneously within 2 to 3 days. At the present time, we only have three patients with neonatal citrullinaemia, aged 1, 6 and 10 years respectively, who are still doing well. One of them has been successfully liver transplanted at 5 years. Another transplanted patient died in the post-surgical phase. We emphasize the unexpected severity of argininosuccinic aciduria in which there is no one patient doing well. This is a rather surprising finding as this disorder is easy to manage and rarely presents with recurrent attacks of hyperammonaemia when it is treated by arginine supplementation. This consideration would suggest to extend the indication of orthotopic liver transplantation in this disorder. Finally, the most difficult indication is in the late onset symptomatic female OTC group. In this last group, despite a significant residual activity due to heterozygote status, even with a variable lyonisation, only seven girls are still mentally and neurologically normal. Interestingly, three of these seven were liver-transplanted before the constitution of irreversible neurological damage. These three girls and their family declare their well-being, their feeling to be cured and enjoy their normal life.

Amino Acid Metabolism, Inborn Errors↗

Liver transplantation in propionic acidaemia.

Despite the improvement in dietary therapy during the past 20 years, the overall outcome of severe forms of propionic acidaemia (PA) remains often disappointing. Good results can be obtained at a very high price in terms of medical attention, family burden and high cost. In most early onset forms of PA, the intake of natural protein must be rigidly restricted to 8-12 g/day for the first 3 years of life, and then slowly increased to 15-20 g/day by the age of 6-8 years. Supplementation with a precursor-free aminoacid mixture to provide 1.5 g/kg protein per day is generally recommended, although remains controversial. From the age of 1 year onward, these children are often severely anorectic and most of the diet must be delivered by nocturnal gastric drip feeding or gastrostomy. Metronidazole is very effective in reducing the excretion of propionate metabolites derived from the gut. L-carnitine (50 to 100 mg/kg) is systematically given to promote propionylcarnitine synthesis and excretion. We report here a retrospective study of 33 patients with PA diagnosed during the last 20 years in our hospital. Of them, 2 have been liver transplanted. In these two patients who presented frequent severe and unexpected metabolic decompensations despite good compliance with the dietary therapy, orthotopic liver transplantation (OLT) was done at 7 and 9 years respectively. One child died 15 months after transplantation due to a severe lymphoproliferative disorder; the other child now aged 13.5 years is doing well. Despite a persistent methylcitrate excretion, she is under normal moderate daily protein intake (40-50 g/day) and still on carnitine supplementation. Interestingly, another patient who filled the criteria for OLT (very frequent and severe decompensations leading to frequent admissions to the intensive care unit despite excellent dietary management) was also placed on the list for OLT. From the time he was registered onward, he experienced no further episodes of metabolic decompensation, there was almost no interruption in his daily intake and he gained height and weight and developed well. He was finally removed from the list and is still doing very well 2 years thereafter. Correction of propionylCoA carboxylase deficiency restricted to hepatic tissues seems to induce a change towards clinical normalisation and a milder biochemical phenotype. Liver transplanted PA patients still require slight protein restriction and carnitine treatment. We consider that at the moment OLT should only be performed in severe forms of PA, mostly characterised by frequent and unexpected episodes of metabolic decompensation despite good dietary therapy. However, a strict appreciation of these criteria is difficult. A more generalised indication for OLT in PA will require more information about the long-term outcome of transplanted patients. We should also await other alternatives like auxiliary partial OLT from living donors or transplantation of isolated allogenic hepatocytes, genetically modified or not.

Adolescent↗

Parturition and angioneurotic oedema.

Angioneurotic oedema is a rare disease caused by Cl esterase inhibitor deficiency. Hereditary angioneurotic oedema includes type I (quantitative and functional) deficiency and type 11 (functional) deficiency. Its prophylactic treatment during pregnancy, based on danazol therapy if the fetus is male, may avoid acute attacks of generalized or laryngeal oedema. It must be instituted before delivery and carried into the postpartum period. If the fetus is female, epsilon aminocaproic acid may be used. The acquired form of angioneurotic oedema can be due to antibodies to C1 esterase inhibitor. A prophylactic therapy is not well established, but high doses of corticosteroids are recommended. Operative delivery is best avoided when possible. Regional analgesia is indicated for labour or caesarean section to prevent pain and stress and to avoid the difficulties associated with laryngeal oedema and tracheal intubation. In the treatment of an acute attack, Cl esterase inhibitor concentrates (1500 units) may be given i.v. We present two cases, one of hereditary and one of acquired angioneurotic oedema, both presenting during pregnancy and both delivered vaginally under epidural analgesia with successful outcome.

Journal Article↗

Mechanisms of drug-induced allergic contact dermatitis.

Allergic contact dermatitis is induced by a wide variety of drugs that trigger specific immune responses following topical exposure. Identified chemical structures involved in such reactions include the mercuric and thiosalicylic acid groups of thimerosal, the diphenylketone group of the anti-inflammatory drug ketoprofen, the amide or ester structure of local anesthetics, and the side-chain and thiazolidine ring of beta-lactams. The T cell responses to such compounds involve CD4+ and CD8+ alphabeta+ T lymphocytes and also CD4 /CD8 gammadelta+ T cells. Although "T helper 2" cytokine production by drug-specific human T cells from patients with allergic contact dermatitis has been described, T helper 1-like and T cytotoxic 1-like responses clearly play key roles in this cutaneous reaction.

Allergens↗