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S Perrin

Publications and source records attributed to S Perrin.

31 records · Page 2Linked to original sources
PubMed1993

Effects of repeated mild stress and two antidepressant treatments on the behavioral response to 5HT1C receptor activation in rats.

This study investigated the possible involvement of 5HT1C receptors in the development of depressive states and in the mode of action of antidepressants. The effects of repeated unpredictable mild stress (a regimen known to induce an anhedonic state in the rat) and of chronic administration of either of two recognized antidepressant treatments (sleep deprivation or inhibition of monoamine oxidase type A) in rats were studied on a 5HT1C receptor initiated response, i.e. mCPP-induced penile erection. A 3-week period of repeated, but unpredictable exposure to mild stressors induced a shift to the left of the dose-response curve for mCPP-induced penile erection. In contrast, 72-h REM sleep deprivation resulted in a shift to the right of the mCPP dose-response curve and 10-day administration of the monoamine oxidase type A inhibitor moclobemide (20 mg/kg IP bid) also resulted in a decreased number of mCPP-induced penile erections. These findings support the hypothesis that neuronal activities initiated via 5HT1C receptor stimulation may play a role in the pathophysiology and treatment of depression.

Animals↗
PubMed1992

Do childhood anxiety measures measure anxiety?

The Fear Survey Schedule for Children-Revised (FSSC-R), Revised-Children's Manifest Anxiety Scale (RCMAS), and the Modified State-Trait Anxiety Inventory for Children (STAIC-M) are three widely used self-report measures of childhood anxiety. While previous studies have established the reliability of these measures, their validity in discriminating anxious from non-anxious youngsters remains to be established. The present study examines the discriminant validity of the three measures by comparing clinic referred samples of boys with an anxiety disorder (n = 105) or ADHD (n = 59) with a community sample of never-psychiatrically-ill boys (n = 49). Results indicated that the two patient groups differed significantly from the never-psychiatrically-ill group on the RCMAS and STAIC-M, but the anxious and ADHD groups did not differ from each other. None of the three groups differed on the FSSC-R. The implications of these findings for the assessment of childhood anxiety disorders are discussed.

Adolescent↗
PubMed1992

DSM-III-R anxiety disorders in children: sociodemographic and clinical characteristics.

This study investigated the characteristics of each of the specific DSM-III-R (American Psychiatric Association, 1987) anxiety disorders in a clinic sample of 188 anxiety disordered children. Characteristics examined included sociodemographic variables (age-at-intake, gender, and race of the child, and family marital and socioeconomic status) and clinical variables (disorder age-at-onset and severity, and history of additional disorders). Findings are discussed in light of the contemporary literature on childhood anxiety disorders.

Adolescent↗
PubMed1992

Symptoms following mild head injury: expectation as aetiology.

An affective, somatic, and memory check-list of symptoms was administered to subjects who had no personal experience or knowledge of head injury. Subjects indicated their current experiences of symptoms, then imagined having sustained a mild head injury in a motor vehicle accident, and endorsed symptoms they expected to experience six months after the injury. The checklist of symptoms was also administered to a group of patients with head injuries for comparison. Imaginary concussion reliably showed expectations in controls of a coherent cluster of symptoms virtually identical to the postconcussion syndrome reported by patients with head trauma. Patients consistently underestimated the premorbid prevalence of these symptoms compared with the base rate in controls. Symptom expectations appear to share as much variance with postconcussion syndrome as head injury itself. An aetiological role is suggested.

Activities of Daily Living↗
PubMed1991

Clonality in myeloproliferative disorders: analysis by means of the polymerase chain reaction.

The myeloproliferative syndromes are acquired disorders of hematopoiesis that provide insights into the transition from somatic cell mutation to neoplasia. The clonal origin of specific blood cells can be assessed in patients with X chromosome-linked polymorphisms, taking advantage of random inactivation of the X chromosome. We have adapted the PCR for determination of clonality on as few as 100 cells, including individual colonies grown in culture. Amplifying a polymorphic portion of the X chromosome-linked phosphoglycerate kinase (PGK) gene after selective digestion of the active X chromosome with a methylation-sensitive restriction enzyme gave results fully concordant with standard Southern blotting of DNA samples from normal (polyclonal) polymorphonuclear cells (PMN) as well as clonal PMN from patients with myelodysplastic syndrome and polycythemia vera (PCV). We have used this technique to demonstrate heterogeneity of lineage involvement in patients with PCV. The same clinical phenotype may arise from clonal proliferation of different hematopoietic progenitors.

Base Sequence↗
PubMed1991

Anxiety disorders in children and their families.

The first- and second-degree relatives of children with anxiety disorders were compared with relatives of children with attention deficit-hyperactivity disorder and children who had never been psychiatrically ill for lifetime rates of psychopathological conditions, particularly anxiety disorders. Results from blind, diagnostic interviews indicated an increased prevalence of anxiety disorders in the first-degree relatives of children with anxiety disorder compared with relatives of both children with attention deficit-hyperactivity disorder and never psychiatrically ill children. Relationships between specific anxiety disorders in children and their relatives revealed an increased rate of panic disorder among the first-degree relatives of children with over-anxious disorder, compared with the relatives of children with separation anxiety disorder and children with other types of anxiety disorders. There also was a trend for panic disorder to be more prevalent among relatives of children with panic disorder than among relatives of children with anxiety disorder without panic. Obsessive-compulsive disorder was the only other anxiety disorder that appeared to show a similar specific relationship between children and their relatives. In general, the findings from this study suggest that there is a familial component involved in the pathogenesis of childhood anxiety disorders. The specificity of this relationship varies among individual anxiety disorders.

Adolescent↗
PubMed1991

[The homocysteinemia vascular risk factor. Methodologies and application to a clinical case].

Early onset vascular disease unexplained until today by usual risk factors (hyperlipidemia, hypertension, tobacco, stress), can now find an explanation in sulfur amino acid metabolism defect. By transsulfuration, alimentary methionine leads to homocysteine, which is itself turn into cysteine, or remethylated into methionine. Several abnormalities of these different pathways lead to plasma accumulation of homocysteine, which will be responsible of arterial or venous occlusive lesions, concerning peripheral or deep vessels. Homocysteine stays in plasma upon several forms: 75% being linked by disulfide bounds to proteins, 22% as disulfide, homocystine (homocysteine-homocysteine) or mixed-disulfide (homocysteine-cysteine), and less than 3% as free reduced homocysteine. Plasma reduction allows total homocysteine evaluation with amino acid autoanalyzer. The basal plasma homocysteine level is less than 14 microMl. However, levels near this basal value can be found in patients with latent abnormality, which needs to be revealed by a methionine loading test. This study concerns two methodologies and their application to the exploration of a patient with unidentified neurologic disorders. The first one describes a new galenic oral form of methionine. Other authors use the methionine load of 100 mg/kg dissolving it in a fruit juice glass. In order to obtain a complete dissolution of this weakly soluble substance and to ensure its total absorbtion by the patient, we prepare a granular form aimed to give in water a perfect flavoured suspension. The second methodology concerns methionine loading test and amino acid analysis. After 10 hours fasting, a 100 mg/kg peroral methionine load is realized performing 5 EDTA blood samples before and 4, 8, 12 and 24 hours after loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1990

Site-specific mutagenesis using asymmetric polymerase chain reaction and a single mutant primer.

A method is described for preparing site-specific mutants using a polymerase chain reaction (PCR) based protocol. The protocol requires a single mutant primer, and has been used to introduce mutations into DNA fragments ranging in size from 200 bp to 1569 bp in length in the GM-CSF, beta-actin, human growth hormone and erythropoietin genes. Sequence analysis of PCR derived mutant fragments shows an error rate of less than one bp change per 1500 bp incorporated. Single base pair mutations have been introduced into these genes which create unique restriction sites. We demonstrate that these mutant templates may be used for competitive PCR to quantitate mRNA and DNA. This method thus offers a rapid means for producing competitive templates for use in quantitative PCR.

Actins↗
PubMed1990

Analysis of cytokine mRNA and DNA: detection and quantitation by competitive polymerase chain reaction.

The expression of two cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 3 (IL-3), has been investigated in MLA-144 cells before and after induction with phorbol 12-myristate 13-acetate. We describe an adaptation of the polymerase chain reaction (PCR) for highly accurate quantitation of mRNA or DNA from a small number of cells. Aliquots of the PCR mixture containing cDNA copies of the RNA to be assayed were added to serial dilutions of a competitor DNA fragment that differed from the cDNA of interest by having either a small intron or a mutated internal restriction enzyme site. Therefore, the same primers were used to coamplify the unknown and the competitor. The ratio of products remains constant through the amplification and can be readily quantitated. In unstimulated cells, no GM-CSF or IL-3 mRNA could be detected. However, with appropriate induction, mRNA for both cytokines was detected and quantitated in as few as 200 cells. Competitive PCR was also used to accurately quantitate the copy number of the human GM-CSF gene in normal human cells, in a clonal population of cells from a patient with 5q- syndrome, and in a human-hamster cell line known to have only one copy of the human GM-CSF gene.

Base Sequence↗
PubMed1989

Expression of pertussis toxin in Bordetella bronchiseptica and Bordetella parapertussis carrying recombinant plasmids.

Pertussis toxin is produced only by strains of Bordetella pertussis. Cloned genes encoding pertussis toxin from B. pertussis were transferred into Bordetella bronchiseptica and Bordetella parapertussis by conjugation. These transconjugants expressed pertussis toxin at levels comparable to those expressed by B. pertussis. The toxin made by these strains was biologically active in the Chinese hamster cell clumping assay, contained all five subunits, and was mostly periplasmic. Toxin expression appeared to be modulated in the same way as are the vir-regulated genes of B. pertussis. Introduction of these plasmids into B. pertussis failed to produce hypertoxigenic strains. Instead, these transconjugants underwent plasmid loss, gene deletions, or conversion to the avirulent phase.

Antibodies, Monoclonal↗
PubMedDate not supplied

Palindromic unit highly repetitive DNA sequences exhibit species specificity within Enterobacteriaceae.

Palindromic units (PU, or REP for repetitive extragenic palindrome) constitute a family of DNA sequences of 40 nucleotides which is highly repeated in the genome of Escherichia coli. We analysed the presence of PU sequences in 99 different bacterial genomes by cross-hybridization. When PU sequences were used as a probe, only DNA from Enterobacteriaceae closely related to E. coli exhibited an appreciable hybridization signal: Shigella sonnei, Shigella boydii, Salmonella enteritica serotype Typhimurium, Citrobacter freundii and Levinea malonatica. Furthermore, these bacteria could be divided into two groups which corresponded to a slight difference in their PU sequence: the E. coli group includes S. sonnei and S. boydii; the S. enteritica serotype Typhimurium group includes C. freundii and L. malonatica.

Blotting, Southern↗
PubMedDate not supplied

Substance refusal skills in a population of adolescents diagnosed with conduct disorder and substance abuse.

The present study examined substance refusal skills of 44 conduct-disordered male adolescents. Fifty percent of these adolescents were dually diagnosed with substance abuse/dependence. Substance refusal skills were assessed utilizing a role-play test that consisted of four interpersonal scenarios in which a confederate prompted youths to engage in illicit drug and alcohol activity. The test demonstrated adequate interrater agreement and validity. Overall skill in refusing alcohol was positively related to adolescents' perceptions of belonging and attention, and overall skill in refusing illicit drugs was positively related to school performance and social competence. Contrary to expectations, substance refusal skills of dually diagnosed adolescents were comparable to their non-substance-abusing counterparts. Clinical implications of this study are discussed.

Adolescent↗