Biomedical subjects

K Bean

Publications and source records attributed to K Bean.

30 records · Page 2Linked to original sources

PubMed1993

[Occupational activities and pregnancy. Physicians' opinions].

The aim of this paper is to analyse knowledge, opinions and attitudes of doctors, delivering prenatal care, about work and pregnancy. A postal survey was carried out in 1989 among all obstetricians and gynecologists and among a random sample of general practitioners in two French departments: Val-de-Marne and Aube. Response rate was 78% and the sample analysis included 367 respondents. Doctors' knowledge about occupational risks for pregnancy, social regulations and their attitudes about sick leave certifications are described. They are different depending on the specialty--GP or obstetricians--, the geographical department, gender and age of the doctors.

Adult↗

PubMed1993

Molecular cloning of murine FLT and FLT4.

A wide range of growth and differentiation processes are regulated by the signalling of receptor tyrosine kinases (RTKs). We have developed a nested polymerase chain reaction (PCR) procedure with degenerate primers, and used it to identify RTKs expressed in murine fetal thymus. A novel RTK, called FLT4, and the murine homologue of FLT were found, and their PCR fragment sequences were used to isolate larger cDNA clones spanning the complete coding regions of these receptors. FLT4 was found to contain an extracellular region similar to the corresponding sequences of FLT and Flk-1, containing seven immunoglobulin domains.

Amino Acid Sequence↗

PubMed1992

A French version of the Sickness Impact Profile (SIP): stages in the cross cultural validation of a generic quality of life scale.

The Sickness Impact Profile is a quality of life scale developed in the United States which is now widely used in clinical trials in chronic conditions such as chronic obstructive lung disease, angina, rheumatoid arthritis, chronic pain, psoriasis, inflammatory bowel disease and cancer. Validated generic scales permit cross cultural comparisons within disease processes in clinical trials. As a simple, direct translation of a scale is inadequate, we have created a French version of the original US version of the Sickness Impact Profile. The first phase was qualitative. A first French translation of the original US version was back translated into English by three independent translators. A second French version resulted from a consensus reached by a panel of lay subjects and health professionals after comparing the original US version, the first French version and the three back translations. This second version was tested with a group of 40 healthy volunteers. This qualitative phase resulted in a French Test Version with content and face validity. The quantitative phase assessed the equivalence of the rank order of each item, by sub scale, in the US version with that of the French Test Version, ie the rank of the French item was comparable (+/- 2) to the rank of the corresponding US item. The French Test Version was tested with 47 healthy subjects. Of the 136 items of the Sickness Impact Profile, 13 were retranslated to create a final French version. This was similarly tested on ten healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Response of Pseudomonas aeruginosa to pyocyanin: mechanisms of resistance, antioxidant defenses, and demonstration of a manganese-cofactored superoxide dismutase.

Pseudomonas aeruginosa produces a blue pigment, pyocyanin. Pyocyanin is a redox-active phenazine compound that kills mammalian and bacterial cells through the generation of reactive oxygen intermediates. We examined the mechanisms by which P. aeruginosa resists pyocyanin. [14C]pyocyanin was taken up by both Escherichia coli and P. aeruginosa, though more slowly by the latter. Cyanide-insensitive respiration, used as an indicator of intracellular superoxide and/or hydrogen peroxide production, was 50-fold less in pyocyanin-treated P. aeruginosa than in E. coli. P. aeruginosa showed less cyanide-insensitive respiration than E. coli upon exposure to other redox-active compounds (paraquat, streptonigrin, and plumbagin). Electron paramagnetic resonance spectrometry and spin trapping showed that P. aeruginosa generated less pyocyanin radical and superoxide than E. coli. Cell extracts from E. coli contained an NADPH:pyocyanin oxidoreductase which increased the rate of reduction of pyocyanin by NADPH. Conversely, cell extracts from P. aeruginosa contained no NADPH:pyocyanin oxidoreductase activity and actually decreased the rate of pyocyanin-mediated NADPH oxidation. Antioxidant defenses could also reduce the sensitivity of P. aeruginosa to pyocyanin. Under culture conditions of limited phosphate, both pyocyanin production and catalase activity were enhanced. Superoxide dismutase activity was also increased under low-phosphate conditions. When cells were grown in a high-phosphate succinate medium, P. aeruginosa formed a previously described iron-superoxide dismutase as well as a manganese-cofactored superoxide dismutase. These results demonstrate that P. aeruginosa resists pyocyanin because of limited redox cycling of this compound and that under conditions favoring pyocyanin production, catalase and superoxide dismutase activities increase.

Catalase↗

PubMed1992

Regulation of catalase in Neisseria gonorrhoeae. Effects of oxidant stress and exposure to human neutrophils.

We studied the effects of oxidant stress on the catalase activity and hydrogen peroxide sensitivity of Neisseria gonorrhoeae. N. gonorrhoeae is an obligate pathogen of man that evokes a remarkable but ineffective neutrophil response. Gonococci make no superoxide dismutase but express high catalase activity. Gonococcal catalase activity increased threefold when organisms were subjected to 1.0 mM hydrogen peroxide. This increase in catalase activity was marked by a parallel increase in protein concentration recognized by a rabbit polyclonal antibody raised against the purified gonococcal enzyme. Catalase was primarily localized to the gonococcal cytoplasm in the presence or absence of stress; only a single isoenzyme of catalase could be identified. Exposure of gonococci to neutrophil-derived oxidants was accomplished by stimulating neutrophils with phorbol myristate acetate or by using gonococcal Opa variants that interacted with neutrophils with different degrees of efficiency. Gonococci exposed to neutrophils demonstrated a twofold increase in catalase activity in spite of some reduction in viability. Exposure of gonococci to 1.0 mM hydrogen peroxide made the organisms significantly more resistant to higher concentrations of hydrogen peroxide and to neutrophils than control organisms. These results suggest that catalase is an important defense for N. gonorrhoeae during attack by human neutrophils. The rapid response of this enzyme to hydrogen peroxide should be taken into consideration in studies designed to evaluate the interaction between neutrophils and gonococci.

Catalase↗

PubMed1992

[French-language adaptation of an evaluation test of knowledge meant for insulin-dependent children: methodology and value for research in clinical practice].

A measure of knowledge level of diabetic patients is useful in evaluating their educational needs as well as the impact of the educational programs specifically designed for them. The lack of such scales in French, led us to translate and validate an existing knowledge scale for diabetic children, the Test of Diabetes Knowledge (TDK) (Johnson et al.). After several translations and back translations, the 33 item scale was submitted to the staff members of a pediatric diabetology unit, to establish its content validity. An assessment the questionnaire was performed in a group of 49 children, aged 7.9 to 12.8 years. The mean duration of diabetes was 4.6 +/- 2.9 years and their scholastic level varied from 1st to 6th grades. Time spent in filling out the questionnaires was 12 to 25 minutes. Few missing values were noted. The reliability of the scale was excellent as shown by Cronbach's alpha coefficient: 0.83 for the overall scale, 0.72 for the general knowledge subscale (20 items) and 0.70 for the problem solving subscale (13 items). The level of correct responses was correlated with age and scholastic level (p < 0.0001), but not with sex, duration of diabetes, or HbA1c levels. This study shows that the French version of the TDK is a valid and reliable tool for measuring the level of knowledge in children and adolescents with diabetes. This scale provides the researcher and clinician with a tool that facilitates the performance of an educational diagnosis and the evaluation of educational programs based on the transmission knowledge.

Adolescent↗

PubMed1991

Human interleukin-9: genomic sequence, chromosomal location, and sequences essential for its expression in human T-cell leukemia virus (HTLV)-I-transformed human T cells.

We have isolated the genomic sequence of human interleukin-9 (IL-9) based on its sequence homology with a human IL-9 cDNA isolated from human T-cell leukemia virus (HTLV)-I-transformed T cells by expression cloning. The entire genomic sequence has been determined and the gene consists of five exons and four introns. The human IL-9 gene is mapped to the long arm of human chromosome 5 at band 5q31-32, a region found to be deleted in a number of patients with acquired 5q- abnormalities and hematologic disorders. Several blocks of transcriptional control sequences have been identified at the 5'-flanking region of the human IL-9 gene that may play an important role in the control of IL-9 gene expression. The 5'-regulatory region of the human IL-9 gene also contains sequences identified in the 5'-flanking regions of other cytokine genes mapped to the long arm of human chromosome 5, including IL-3, IL-4, IL-5, and granulocyte-macrophage colony-stimulating factor and other T-cell growth factor genes including IL-2 and IL-6. The IL-9 gene is constitutively expressed in the HTLV-I-transformed human T cells and the expression of IL-9 in these cells can be further induced by 12-O-tetradecanoyl phorbol 13-acetate. Transient transfection analysis using the plasmid containing the 5'-flanking region of IL-9 gene upstream from the firefly luciferase ciferase report gene indicated that the 0.9-kb Smal-Sacl fragment of the IL-9 gene contains sequences required for the constitutive and activated expression of IL-9 gene in HTLV-I-transformed cells. These results will now allow us to study the regulatory mechanism of IL-9 gene expression in normal and leukemic human T cells.

Amino Acid Sequence↗

PubMed1991

Molecular cloning and characterization of a complete Chinese hamster provirus related to intracisternal A particle genomes.

We report here the nucleotide sequence of a full-length Chinese hamster genomic proviral element, CHIAP34. CHIAP34 is 6,403 bp long with long terminal repeats of 311 bp at each end. The genetic organization of CHIAP34 was determined by comparison with intracisternal A particle (IAP) genetic elements from the mouse and Syrian hamster. Extensive homology at the nucleotide and deduced amino acid sequence levels was observed between CHIAP34 and the mouse and Syrian hamster IAP elements. CHIAP34 may represent a defective Chinese hamster IAP genetic element. The gag gene consists of 837 codons, of which 558 codons are in a single long open reading frame followed by several frameshifts. The pol gene begins with a -1 frameshift and consists of a long open reading frame of 753 codons followed by a short open reading frame of 103 codons. The putative env region contains multiple termination codons in all reading frames. CHIAP34 is representative of the predominant retroviral elements in the Chinese hamster ovary cell genome present at around 80 copies per haploid genome.

Amino Acid Sequence↗

PubMed1991

[Validation in the French language of an evaluation scale for family functioning (FACES III): a tool for research and for clinical practice].

Valid and reliable scales are necessary to describe the numerous factors associated with health status. Multiple studies have shown the impact of familial factors, i.e. family functioning (FF) on health indicators. As no scale exists in french to assess FF, we performed a study to validate the Family Adaptability and Cohesion Evaluation Scale (FACES III, Olson et al.) in french. This scale has a high level of validity and reliability and has been widely used. After 2 translations and back-translations and a pilot study to establish face validity, the final version was studied in 976 healthy subjects (457 families) who attended a preventive medical center in Nancy, France. Parents and adolescents each filled out two 20 item self-administered questionnaires. There were few missing values (0-3% per item). Construct validity was assessed by principal component factor analysis, which found the same two individualized axes as in the original scale. The reliability of the french version was excellent and comparable to Olson's scale. This study demonstrates the validity and reliability of a french version of FACES III in a french population. It provides researchers and clinicians in France with a validated instrument for assessing, in a quantified way, factors associated with family functioning that influence health status in adults, adolescents and children, particularly those with chronic diseases. This scale is especially useful for developing and evaluating health programs.

Adolescent↗

PubMed1989

The role of hydroxyl radical in chromosomal and plasmid damage in Neisseria gonorrhoeae in vivo.

Viable Neisseria gonorrhoeae exposed to streptonigrin generate intracellular hydroxyl radical detected by spin-trapping with 5,5-dimethyl-l-pyrroline-N-oxide; gonococci exposed to paraquat generate primarily superoxide (J. Biol. Chem., 262: 13404-143048, 1987). The use of streptonigrin and paraquat provide a model with which to examine the action and site(s) of hydroxyl radical-mediated damage. N. gonorrhoeae exposed to streptonigrin, but not paraquat, developed extensive chromosomal, plasmid, and RNA damage. Addition of excess Fe+3 to the reaction mixture enhanced intracellular hydroxyl radical formation by paraquat, detectable as DNA damage. Desferal and dimethyl sulfoxide allowed approximately 25% of protection of plasmid DNA damage as judged by linear scanning densitometry. These results demonstrate DNA and RNA damage in viable organisms exposed to intracellular redox stress and confirm the critical role of hydroxyl radical in this process.

Chromosomes, Bacterial↗

PubMed1987

Preliminary observations on lactoferrin secretion in human vaginal mucus: variation during the menstrual cycle, evidence of hormonal regulation, and implications for infection with Neisseria gonorrhoeae.

The concentration of the iron-binding protein lactoferrin was measured in vaginal mucus of women throughout the menstrual cycle. Lactoferrin is proposed to limit growth of mucosal pathogens such as Neisseria gonorrhoeae. Lactoferrin concentration in mucus was highest just after menses (62.9 to 218 micrograms/mg of protein) and lowest (3.8 to 11.4 micrograms/mg of protein) just before menses. Overall concentration of mucus protein showed no variation with menstrual cycle, and little lactoferrin was detectable in cell debris. Plasma lactoferrin did not show the variation seen in vaginal mucus. Because of the suggestion of hormonal influence on vaginal lactoferrin, its concentration was determined in women receiving oral contraceptive therapy. Mean lactoferrin concentration in women taking oral contraceptives was significantly lower than in the control group (never exceeding 19.8 micrograms/mg of protein) and showed no monthly variation. Vaginal lactoferrin appears to be under hormonal control. Variation in vaginal lactoferrin concentration may result in alterations in susceptibility to bacterial pathogens such as Neisseriae gonorrhoeae.

Cervix Mucus↗

PubMed1987

Role of extracellular iron in the action of the quinone antibiotic streptonigrin: mechanisms of killing and resistance of Neisseria gonorrhoeae.

The quinone antibiotic streptonigrin is believed to kill bacteria by promoting formation of oxygen radicals. This antibiotic has also been used to select resistant bacterial mutants, some of which vary in iron utilization. We examined the effects of streptonigrin on Neisseria gonorrhoeae and several types of gonococcal mutants. Streptonigrin (0.025 microgram/ml) efficiently killed gonococcal strain FA1090, and this effect depended on iron. Streptonigrin-resistant mutant FA6271 had normal iron uptake but was moderately deficient in total iron. Resistance most likely resulted from failure of FA6271 to divert electrons to streptonigrin, as demonstrated by a reduction in KCN-insensitive respiration (a hallmark of the action of quinones) and superoxide formation. Other mutants selected for inability to use human iron-binding proteins (strains FA6273 and FA6275) had no increase in streptonigrin MIC and no decrease in KCN-insensitive respiration. Mutants did not demonstrate an increase in superoxide dismutase or catalase. Streptonigrin killing of gonococci depended on a reaction(s) in which extracellular iron was important, presumably because iron was required for catalysis of hydroxyl radical. The results suggest that a membrane component may be a target for the actions of streptonigrin.

Catalase↗