Biomedical subjects

S Perrin

Publications and source records attributed to S Perrin.

At least 19 recordsLinked to original sources

PubMed2002

Characterization of a purified beta-fructofuranosidase from Bifidobacterium infantis ATCC 15697.

AIMS: To characterize the beta-fructofuranosidase of Bifidobacterium infantis ATCC 15697 and to compare it with other bacterial beta-fructofuranosidases. METHODS AND RESULTS: The beta-fructofuranosidase of B. infantis ATCC 15697 was purified 46.8 times over the crude extract by anion exchange chromatography, ultrafiltration and gel filtration. The sequence of 15 amino acid residues of the NH2 terminal was determined. This enzyme was a monomeric protein (Mr 70 kDa) with beta-fructofuranosidase and invertase activities. The isoelectric point was pH 4.3, the optimum pH 6.0 and pKas (4.5 and 7.2) of two active groups were obtained. The activities were inhibited by Hg2+ and p-chloromercuribenzoic acid (pCMB). The optimal temperature was 37 degrees C and activities were unstable at 55 degrees C. beta-fructofuranosidase activity was more efficient than that of invertase with Vm/Km ratios of 0.65 and 0.025 x 10-3 l min(-1) mg(-1), respectively. The enzyme catalyses the hydrolysis of fructo-oligosaccharides, sucrose and inulin at relative velocities of 100, 10 and 6, respectively. CONCLUSIONS: The enzyme of B. infantis ATCC 15697 is an exo-inulinase which has beta-fructofuranosidase and invertase activities. This protein was different from the beta-fructofuranosidase of another strain of B. infantis (B. infantis JCM no. 7007). SIGNIFICANCE AND IMPACT OF THE STUDY: A better knowledge of bacterial beta-fructofuranosidases, especially from bifidobacteria, has been gained.

Bifidobacterium↗

PubMed2002

Fermentation of chicory fructo-oligosaccharides in mixtures of different degrees of polymerization by three strains of bifidobacteria.

We estimated and compared the action of three selected strains of bifidobacteria in a semi-synthetic medium for different degrees of polymerization of fructo-oligosaccharides contained in three commercial products derived from chicory inulin: Fibrulose F97 (shorter chains), Fibruline Instant (native chains), Fibruline LC (longer chains). Biomass and production of lactate and acetate were greater when the substrate contained mostly shorter chain fructo-oligosaccharides. Shorter chains were first to be consumed, and one strain could use longer chains. As the degree of polymerization increased, residual fructo-oligosaccharides increased after growth of the strains, and the rate of consumption of fructo-oligosaccharides decreased.

Acetates↗

PubMed2001

Fermentations of fructo-oligosaccharides and their components by Bifidobacterium infantis ATCC 15697 on batch culture in semi-synthetic medium.

AIMS: To compare the physiological behaviour of Bifidobacterium infantis ATCC 15697 growing on synthetic oligofructose or its components. METHODS AND RESULTS: The studies were carried out in regulated or non-regulated batch cultures on semi-synthetic media. Differences between the carbohydrate utilization patterns with glucose, fructose, sucrose and fructo-oligosaccharides (FOS) were determined. Glucose was the preferred substrate for growth and biomass production, whereas fructose was the best for lactate and acetate production. With sucrose, biomass production reached the level obtained with glucose, whereas with FOS, more metabolites were produced, as with fructose. In a mixture of FOS, the shorter saccharides were used first and fructose was released in the medium. Fructofuranosidase, an enzyme necessary to hydrolyse FOS, was inducible by fructose. CONCLUSION: Glucose contained in FOS and sucrose might sustain growth and cell production, while fructose might enable the production of major metabolites. SIGNIFICANCE AND IMPACT OF THE STUDY: A better understanding of the bifidogenic nature of oligofructose has been gained.

Bacterial Proteins↗

PubMed2001

War exposure and maternal reactions in the psychological adjustment of children from Bosnia-Hercegovina.

As part of a UNICEF-sponsored Psychosocial Programme in Bosnia, data were collected from a representative sample of 339 children aged 9-14 years, their mothers, and their teachers in order to investigate risk and moderating factors in children's psychological reactions to war. Self-report data from children revealed high levels of post-traumatic stress symptoms and grief reactions, but normal levels of depression and anxiety. Mothers' self-reports also indicated high levels of post-traumatic stress reactions, but normal levels of depression and anxiety. Child distress was related to both their level of exposure and to maternal reactions. Structural equation modeling was used to quantify the relationships between these risk factors and child distress, and to examine putative pathways to account for the association between child and maternal health. Children's adjustment was associated significantly with both exposure (phi = .37) and maternal mental health (phi = .37). Modeling also revealed a significant distorting effect of mother's own mental health on behavioural ratings of her child (psi = .59). Although evidence exists for an association between maternal mental health and mother rating errors, there is also a substantive association between maternal mental health and children's adjustment following war.

Adaptation, Psychological↗

PubMed2000

Effects of fructooligosaccharides and their monomeric components on bile salt resistance in three species of bifidobacteria.

The influence of fructooligosaccharides (FOS) and their monomeric components on bile salt resistance of Bifidobacterium breve ATCC 15700, Bif. longum ATCC 15707 and Bif. animalis ATCC 25527 was examined. The neosugars induced fructofuranosidase activities for the degradation of these saccharides. For the three strains tested the growth was identical and bile salts had the same inhibitory effect on growth whatever the carbohydrate used. The survival of Bif. breve and Bif. longum, in the presence of glycodeoxycholic acid depended, however, on carbohydrates: the toxic effects of the bile salt could be partly alleviated by the addition of a metabolizable C-source. For Bif. animalis, the presence of any carbohydrate in the incubation medium did not enhance the viability of the strain. But in the three deconjugating strains of bifidobacteria studied, the presence of neosugar during the growth led to improved resistance to the bactericidal effect of the bile salt compared with the monomeric components of these neosugars (glucose and fructose).

Animals↗

PubMed2000

Bile salt toxicity to some bifidobacteria strains: role of conjugated bile salt hydrolase and pH.

The purpose of this work was to study some aspects of bile salt toxicity towards bifidobacteria. A strain (Bifidobacterium coryneforme ATCC 25911) was selected for its lack of conjugated bile salt hydrolase activity (CBSH-), and was used with three deconjugating strains (CBSH+), for study of their growth and viability in the presence of two dihydroxylated conjugated bile salts (tauro- and glyco-deoxycholic acids). The presence of the glycoconjugate induced a more significant growth inhibition for the four strains than the tauroconjugate. The viability of the strains was measured at several pH levels. Glycodeoxycholic acid, but not taurodeoxycholic acid, exerted a lethal effect, which increased at low pH. This phenomenon was more pronounced for the CBSH- strain. We explain some of these results using an hypothesis based on the consequence of dissociation of conjugated and deconjugated bile salts, and the value of their pKa.

Amidohydrolases↗

PubMed2000

The assessment and treatment of Post-traumatic Stress Disorder in children and adolescents.

Post-traumatic Stress Disorder (PTSD) is a syndrome defined by the intrusive re-experiencing of a trauma, avoidance of traumatic reminders, and persistent physiological arousal. PTSD is associated with high levels of comorbidity and may increase the risk for additional disorders over time. While controversies remain regarding the applicability of the PTSD criteria to very young children, it has proved to be a useful framework for guiding assessment and treatment research with older children and adolescents. This article presents an overview of the literature on the clinical characteristics, assessment, and treatment of PTSD in children and adolescents.

Adaptation, Psychological↗

PubMed1999

The zebrafish swimbladder: A simple model for lung elastin injury and repair.

In this communication we offer data to suggest that the zebrafish swimbladder may provide a simple model of elastin injury and repair which is amenable to genetic analysis and pertinent to lung physiology. In situ hybridization of zebrafish embryos illustrated that elastin gene expression is evident in the developing gut tract prior to swimbladder morphogenesis. Northern blot analysis demonstrated that the major zebrafish elastin mRNA is 2.0 kb which is significantly smaller than its higher vertebrate counterpart. Amino acid analysis of alkali-resistant protein from the anterior chamber of the adult zebrafish swimbladder showed a composition similar to higher vertebrate elastins including significant amounts of desmosine crosslinks. Electron microscopic investigations of the swimbladder wall indicate a simple structure with an inner layer of elastin fibers. Elastase delivery to the swimbladder in vitro resulted in significant fragmentation of elastin in the anterior chamber providing an environment for studying elastin repair within the tissue.

Air Sacs↗

PubMed1998

Social desirability and self-reported anxiety in children: an analysis of the RCMAS Lie scale.

There are important applied and theoretical reasons for research into the association between social desirability and self-reported anxiety in young people. The aim of this study was to examine the relationship between anxiety and social desirability in a large normative sample of 7- to 14-year-olds (N = 1,786). Participants completed the Revised Children's Manifest Anxiety Scale and their teachers rated children as anxious-not anxious according to specified descriptions. Results indicated that anxiety and lie scores do not correlate for either gender or age grouping. However, anxiety scores interacted with lie scores differently for males and females in terms of the agreement between children's and teacher's ratings of anxiety. Indications are that social desirability levels may in part explain the consistent discrepancies found between child and adult reports of anxiety in young people.

Adolescent↗

PubMed1997

Worrisome thoughts in children clinically referred for anxiety disorder.

Administered a 31-item worry measure, based on criteria from the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) for anxiety disorders, to referred children with anxiety disorders (n = 72) or attention deficit hyperactivity disorder (ADHD; n = 50), and to nonreferred, never psychiatrically ill controls (n = 55). Anxiety and ADHD groups did not differ for self-reported worries. Anxious children did report more "intense" worries about separation and social evaluation than controls. ADHD children reported more intense worries about friends and school than controls. Separation worries were most prevalent in children with separation anxiety disorder, thus distinguishing this subgroup from both control groups. Results suggest that intense worries specific to one's anxiety disorder are more clinically relevant than the overall level of worry. Implications for assessment of worry are discussed.

Adolescent↗

PubMed1997

Developmental regulation of elastin gene expression.

Developmental regulation of elastin gene expression appears to be exerted primarily at the transcriptional level. Although the elastin gene promoter possesses features of "housekeeping" genes, these characteristics do not preclude transcriptional regulation as shown with a number of other gene promoters of this class. Direct evidence for transcriptional regulation has been obtained by nuclear run-on analysis of nuclei isolated from developing lung and aortic tissues and indirectly through elastin promoter activity in transgenic mice and transient tissue transfections of embryonic lung and aortic tissues. Although several different modulators have been proposed to control the developmental activation of elastin gene expression, only insulin-like growth factor I has been experimentally linked to increased transcription by in vivo studies. This link is specific for aortic smooth muscle cells in which cell cycle control appears intimately associated with elastogenesis. Recent studies suggest that progress in understanding developmental activation of the elastin gene lies in transgenic models and organ transfection assays that assess the direct relevancy of the modulators and cis- and trans-acting factors involved.

Animals↗

PubMed1997

Validation of the Keane MMPI-PTSD Scale against DSM-III-R criteria in a sample of battered women.

The Keane, Malloy, & Fairbank (1984) MMPI-PTSD Scale has proven to be a reliable and valid measure of posttraumatic stress disorder (PTSD) in combat veterans. However, few studies have examined the MMPI-PTSD Scale's validity in civilian trauma victims, including battered women. In the present study, 46 battered women who completed the MMPI-PTSD Scale were assigned to PTSD-Positive and PTSD-Negative groups based on a structured diagnostic interview and then contrasted on the MMPI-PTSD Scale. Significantly higher scores on the scale were found in the PTSD-Positive group. Also, a cutoff score of 22 on the MMPI-PTSD Scale correctly classified 80.4% of the sample. Correlations between the MMPI-PTSD and DSM-III-R criteria suggest that the scale is moderately sensitive to many of the symptoms particularly those involving intrusion and psychological arousal, comprising the diagnosis of PTSD. This investigation provides further support for the validity of the MMPI-PTSD Scale and its utility in screening battered women for PTSD.

Adolescent↗

PubMed1996

Assessing the effects of violence on women in battering relationships with the Keane MMPI-PTSD Scale.

The Minnesota Multiphasic Personality Inventory (MMPI)-Keane Posttraumatic Stress Disorder (PTSD) Scale (PK) has proven to be a reliable and valid measure of PTSD in combat veterans. However, few studies have examined the scale's validity in battered women, who often present with PTSD. Using empirically derived cutoff scores for the PK Scale, 69 battered women were assigned to PTSD-Positive and PTSD-Negative groups and then compared on measures of PTSD, distress, social support, and history of abuse in and out of the battering relationship. The PTSD-Positive group scored significantly higher across all measures of PTSD and distress, supporting the concurrent validity of the PK Scale in this population. However, the two groups differed only for the frequency of death threats, suggesting that the PK Scale is only mildly sensitive to the level of trauma exposure. Finally, lower levels of perceived social support were found in the PTSD-Positive than the PTSD-Negative group. Implications of these findings for the assessment of PTSD in battered women are discussed.

Adolescent↗

PubMed1996

Relationship between ADHD and anxiety in boys: results from a family study.

OBJECTIVE: Recent studies have found an increased risk for both anxiety disorder and attention-deficit hyperactivity disorder (ADHD) in the adult relatives of children with ADHD in comparison with adult relatives of normal controls. Such findings may account for the high rates of comorbid anxiety found in children with ADHD, and they suggest a relationship between the two disorders. However, additional studies are needed to address this relationship that include both anxiety disorder and normal control groups. METHOD: The first- (n = 239) and second-degree relatives (n = 1,266) of clinically referred boys with ADHD (n = 49), clinically referred boys with anxiety disorder (n = 46), and controls who have never been psychiatrically ill (NPI controls) (n = 37) were assessed with structured interview and diagnosed according to DSM-III-R criteria. Lifetime rates of ADHD and anxiety disorder were then compared for relatives in the three proband groups. RESULTS: Female relatives of ADHD probands had significantly higher rates of anxiety disorder than female relatives of NPI controls. However, relatives of anxious probands and NPI controls did not differ for ADHD. Furthermore, no evidence of cosegregation of anxiety disorder with ADHD was found in the relatives of probands in the two patient groups. CONCLUSIONS: ADHD and anxiety may share common risk factors but appear to be independently transmitted in families. The high rate of anxiety in female relatives of ADHD probands was comparable with that found in relatives of anxious probands and warrants further investigation.

Anxiety Disorders↗

PubMed1996

A prospective study of childhood anxiety disorders.

OBJECTIVE: To evaluate course and outcome of DSM-III-R anxiety disorders prospectively in clinically referred children. METHOD: Children were blindly and repeatedly assessed with a structured diagnostic interview over a 3- to 4-year period to determine recovery from anxiety disorder and development of new psychiatric disorders. Both psychopathological (attention-deficit hyperactivity disorder, n = 50) and never psychiatrically ill (NPI, n = 83) controls served as comparison groups for children with anxiety disorders (n = 84). RESULTS: The majority of children (82%) were free from their intake anxiety disorders by the end of the follow-up. Relapse of these anxiety disorders after remission was rare (8%). During follow-up, anxious children were more likely to develop new psychiatric disorders (30%), primarily new anxiety disorders (16%), than were NPI children (11% and 2%, respectively), but not psychopathological controls (42% and 10%, respectively). CONCLUSIONS: Overall, results suggest a favorable outcome with respect to diagnostic status for clinically referred children with anxiety disorders. However, these children may be at risk for new psychiatric disorders over time.

Adolescent↗

PubMed1994

Effects of isozyme-selective phosphodiesterase inhibitors on eosinophil infiltration in the guinea-pig lung.

The effects of selective phosphodiesterase isozyme inhibitors on eosinophil infiltration induced by antigen challenge or by exposure to an aerosol of platelet-activating factor (PAF) were investigated in the guinea-pig. Pretreatment 24 h and 3 h before antigen challenge or PAF exposure with theophylline (100 mg/kg), rolipram (5 mg/kg) and Ro 20-1724 (30 mg/kg) significantly reduced the increase in eosinophil numbers in bronchoalveolar lavage fluid. In contrast, milrinone, SK&F 94-120 and zaprinast were ineffective against antigen-induced eosinophil recruitment. Theophylline, rolipram and Ro 20-1724 also significantly reduced the release of eosinophil peroxidase into the bronchoalveolar lavage fluid. It is suggested that inhibitors of type IV phosphodiesterase have anti-inflammatory effects in the airways and may be useful in the treatment of asthma.

Aerosols↗

PubMed1994

The potential for faking on the Mississippi Scale for Combat-Related PTSD.

The Mississippi Scale for Combat-Related PTSD is widely used in the assessment of post-traumatic stress disorder (PTSD). The high face-validity of the scale may make it vulnerable to faking, however. The present study found that the scores of individuals instructed to respond "as if" they had PTSD did not differ from the scores of veterans with PTSD. Furthermore, although veterans who were diagnosed as having PTSD were found to have significantly higher Mississippi Scale scores than those who did not meet diagnostic criteria for PTSD, the mean score for all groups (veteran and non-veteran) exceeded the originally recommended diagnostic cut-off score of 107. A cutoff score of 121 was found to best differentiate veterans with PTSD from veterans who did not meet diagnostic criteria for the diagnosis, with high sensitivity but relatively low specificity.

Combat Disorders↗

PubMed1993

Anxiety disorders in African-American and white children.

There are little available data on African-American children with anxiety disorders. Treatment-seeking African-American (n = 30) and white children (n = 139), with a current DSM-III-R anxiety disorder, were compared on sociodemographic background variables, clinical characteristics, and lifetime rates of specific DSM-III-R anxiety disorders. Overall, results suggested that the anxiety-disordered African-American and white children who sought treatment from an outpatient mental health facility were more similar than different. The two groups did, however, differ somewhat on several variables (trend only), including rates of school refusal, severity of primary anxiety disorder, lifetime prevalence of posttraumatic stress disorder, and total scores on the Fear Survey Schedule for Children-Revised. More specifically, white children were more likely to present with school refusal and higher severity ratings, while African American children were more likely to have a history of posttraumatic stress disorder and score higher on the FSSC-R. The impact of these findings and the need for additional research are discussed.

Adolescent↗