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Biomedical subjects

G Boyer

Publications and source records attributed to G Boyer.

At least 19 recordsLinked to original sources

3D behaviour of Frieden filters in confocal imaging.

The three-dimensional (3D) focal behaviour of the super-resolving Frieden filters is investigated numerically. It is shown that, as the central bright spot is sharpened, super-giant secondary maximums are formed on the optic axis. These lobes are much higher that the well-known side-lobes inherent to spatial filtering that surround the restricted, utilisable field, whose characteristics in the meridional plane are depicted for various values of the space-bandwidth parameter and for various numbers of terms that compose the window function. The two-terms filter is found to present, for the first time to my knowledge, some axial apodizing properties. To be compatible with practical realisation, the use of this class of filters in a single- and two-photon confocally scanned system is discussed in terms of 3D super-resolution with an intentionally limited light-power loss. It is shown that these filters match particularly well with recently designed axial apodizers for the transmission-mode confocal scanning microscope and provide a 3D intensity point-spread volume reduction of variable amount as high as 37 percent. The filtering process is shown to vary significantly with the mode of operation.

Filtration↗

Perceived and valued roles of adults with severe mental health problems.

The purpose of this article is to convey the findings of two studies related to the perception of past, present and future roles, the value attributed to these roles as well as the role patterns. Both studies were conducted with adults who have schizophrenia and are involved in a rehabilitation or work program. Data were collected from two sources: 1) secondary analysis of a study related to the methodology for validating the French translation (Hachey, Jumoorty, & Mercier, 1995) of the "Role Checklist", (Barris, Oakley, & Kielhofner, 1988) and 2) a research project on the perception of roles and quality of life. Results showed that the dominant roles assumed by participants regardless of time were family member, friend, home maintainer and hobbyist. The most valued roles were those of friend, worker, and family member. The discussion will address the questions asked and elucidate the role patterns. The conclusion underlines the importance, for occupational therapists and health professionals, of including roles in the daily lives of their clients, taking into consideration the ones they value most highly.

Activities of Daily Living↗

[The Edinburgh Postnatal Depression Scale: the validity of its Quebec version for a population low socioeconomic status mothers].

This paper investigates the construct validity and reliability of a Quebec version of the Edinburgh Postnatal Depression Scale (EPDS) for a population of low-socioeconomic-status mothers. This scale was constructed for the specific purpose of measuring mothers' symptoms of depression during the postnatal period in an effort to alleviate the validity problems that could arise from depression scales intended for the general population. Two hundred and twenty-four mothers participating in a Quebec prevention program, "Naître égaux, grandir en santé" (Martin & Boyer, 1995) filled out the EPDS between the 22nd and the 35th day postpartum. A confirmatory factor analysis, conducted with LISREL, gives a 2-factor structure for the EPDS, the first representing symptoms of depression and the second symptoms of anxiety. This structure differs from the one presented by Cox, Holden, and Sagovsky (1987), authors of the EPDS. It corresponds, however to the results of other authors who looked at the EPDS with confirmatory factor analysis (Pop, Komproe, & van Son, 1992) and indicates a good construct validity. The reliability of the scale also appears satisfactory, with a Cronbach alpha co-efficient of 0.82.

Adolescent↗

An evaluation of psychometric properties of the client's questionnaire of the Wisconsin Quality of Life Index-Canadian version (CaW-QLI).

Psychometric properties of Client's questionnaire from the Canadian version of the Wisconsin Quality of Life-Index (CaW-QLI) were assessed with two groups, 89 English (E) and 94 French (F) individuals with schizophrenia or schizoaffective disorder. Sub-samples of 40 E and 36 F were re-interviewed within a 2-week period. Spearman correlations-SC between each domain and CaW-QLI global Score ranged from 0.39 to 0.76, while interdomain correlations were low, confirming the multi-dimensional properties of the scale. Cronbach's alpha (internal consistency) were 0.78 (E) and 0.70 (F) for the CaW-QLI global scores and, from 0.45 to 0.88 among seven of eight domains. Test-retest (Concordance Correlation Coefficient--CCC) ranged from 0.36 to 0.80 among the domains, and from 0.80 (E) and 0.85 (F) between CaW-QLI global scores. Regarding convergent validity, SC between CaW-QLI global score and Spitzer's QOL-Index were 0.72 (E) and 0.58 (F). As hypothesized, there were higher correlations between CaW-QLI global scores (E and F) and SF-36 scales related to mental health than those related to physical health. Minor changes in the scoring are proposed to enhance face and content validity.

Adolescent↗

[Perception of social support given by health professionals according to the participants in a prenatal prevention program who live in extreme poverty].

One of the essential elements of the "Programme intégré de prévention en périnatalité--Naître-égaux-Grandir-en-san t" (Born Equal--Brought up Healthy) is to have a health professional offering general support to pregnant women living in poverty. This research is based on a secondary analysis of the transcriptions of interviews done in order to implement the program. The thematic content analysis was employed to analyze the women's perception of the support provided by the health professional, the relationship between client-professional, and the perceptions of these women about the impact that the social support had on their pregnancy experience. The categories of support that emerged from the analysis are: information support, emotional support, instrumental support, changing life style support, recreational support, and availability of support. The categories of impact perceived by the participants are: learning, changes in life style, to be in a good mood, and the use of community resources. A key element in the perception of support by the participants is the establishment of a relationship of trust between professional and client. This relationship of trust is important to the development of intimacy and to foster the perception of a more intense kind of support. Hence social support and the relationship of trust work in synergy and reinforce each other.

Attitude to Health↗

T-cell receptor polymorphisms in Tlingit Indians with rheumatoid arthritis.

Rheumatoid arthritis (RA) develops as a result of the interaction of both genetic and environmental factors. Among the genes in humans that have been suggested as candidate susceptibility genes in RA are those encoding the T cell receptor for antigen (TCR). A high prevalence and early age of onset of RA has previously been reported in Alaskan Tlingit Indians. In this study, the frequency of seven different restriction fragment length polymorphisms (RFLPs) in the TCR alpha and beta gene complexes were measured in a population of Alaskan Tlingit Indians. No statistically significant differences were noted when the frequencies of these RFLPs were compared between Tlingits with RA and healthy controls (p > 0.05). These results do not support the hypothesis of an RA-susceptibility allele in the vicinity of these TCR alpha or beta genes. Since TCR RFLPs have not been extensively studied in native American populations, TCR polymorphism frequencies in the Tlingits were also compared to the frequencies observed in a second control group of healthy Caucasians. Statistically significant differences were observed in these comparisons implying a different distribution of individuals in these populations with different TCR repertoires.

Alleles↗

[In vitro activity of glycopeptides on 114 coagulase-negative staphylococci: problems with the teicoplanin diffusion test, "alert" parameters indicating need for MIC determination].

The activity of vancomycin (Va) and teicoplanin (Tc) against 114 coagulase-negative staphylococci (CNS) strains was evaluated by disk-diffusion and agar dilution minimal inhibitory concentration (MIC) determination. Results were analysed by species and methicillin-resistance (MR) status. MICs for Va were in the susceptible range (< 4 mg/l) for all strains, with inhibition zone diameters of 17 mm or more in every case. MICs for teicoplanin were 8 or 16 mg/l for 19 CNS strains (including 18 with MR) of which 14 yielded an inhibition zone diameter of 17 mm or more (false susceptibility). Parameters which should lead to MIC determination for Tc regardless of disk diffusion findings include the species (S. haemolyticus), methicillin resistance, Tc zone diameter, and an at least 3 mm difference between the Va and Tc zone diameters.

Dose-Response Relationship, Drug↗

HLA antigens in Tlingit Indians with rheumatoid arthritis.

HLA-DR4 has been described in association with rheumatoid arthritis (RA) in multiple populations. We have studied HLA antigens in Alaskan Tlingit Indians. HLA-DR4 was decreased in the RA group (n = 32) compared with controls (n = 62) (6% vs 21% p = 0.07). The predominant DR4 allele observed was DRB1*0403 (Dw13.1). The most striking observation in these studies was a marked predominance of the DRB1*1402 allele encoding Dw16 (DRw14). This allele was present in 91% of RA cases, but was also highly prevalent in controls (80%, OR = 2.4 p = 0.20). DRB1*1402 only was observed in 47% of cases and 31% of controls. The DRB3*0101 (DRw52), and the DQA*0501 and DQB*0301 alleles encoding a subset of DQw3 were associated with DRB1*1402 in cases and in controls. HLA-Bw62 was increased in RA cases (28%) compared with controls (8%) (OR = 4.5, p = 0.01, corrected p = ns).

Adult↗

[Activity of ethambutol, isoniazid and rifampicin on Corynebacterium urealyticum and Corynebacterium jeikeium].

Because corynebacteria and mycobacteria have walls of similar composition, it was of interest to test the effects on resistant corynebacteria of two agents with anti-wall effects, i.e., ethambutol (EMB) and isoniazid (INH). Rifampicin was also studied to extend previous data and clarify conflicting results in the literature. INH was not active in levels achieved in vivo with standard dosages. The minimal inhibitory concentration (MIC) of EMB was under serum levels for only three of 78 strains. All minimal bactericidal concentration (MBCs) were greater than serum levels. With RIF, 59% of strains were susceptible and 19.2% exhibited intermediate susceptibility as defined by the French Committee on Antimicrobial Susceptibility Testing. CMI and CMB distributions were heterogeneous, suggesting a possible acquired heterogeneous resistance to RIF.

Corynebacterium↗

[Prevention of septicemia caused by gastrointestinal tract organisms in patients with granulopenia. Comparison of three gastrointestinal tract decontamination treatments].

Three gastrointestinal tract decontamination regimens were tested in patients with granulopenia: vancomycin 250 mg, tobramycin 75 mg, and colistin 1 million international units (regimen A); vancomycin 125 mg, tobramycin 75 mg, and colistin 1 million IU (regimen B); and colistin 1 million IU (regimen C); nystatin was added to all three regimens. Effectiveness was evaluated by stool organism counts and blood cultures to detect bacterial translocation (passage of bacteria from the intestinal tract to the bloodstream). Regimen C proved insufficiently effective. Regimen A was found to be poorly tolerated by the digestive mucosa. Regimen B was the best treatment since the low dosage of vancomycin proved effective. Nystatin satisfactorily eliminated yeasts.

Agranulocytosis↗

[Sensitivity curves of multiply resistant corynebacteria JK and D2].

Corynebacteria groups JK and D2 are opportunistic pathogens. They are sometimes responsible for severe infections, especially in immunocompromised patients. They are resistant to many antibiotics. Under these conditions it seemed important to discover which antibiotics among those regularly active, have a killing effect, what their bactericidal speed is, and how they react to combination with other antibiotics. Glycopeptids have a killing effect within 24 hours. Pristinamycin, rifampin, fusidic acid, when active, are bacteriostatic. Their combination with vancomycin is indifferent but in one case the combination vancomycin + rifampin is synergistic.

Anti-Bacterial Agents↗

Pathogenicity in two cases of Staphylococcus schleiferi, a recently described species.

Staphylococcus schleiferi is a new species of coagulase-negative staphylococcus first described in April 1988 (J. Freney, Y. Brun, M. Bes, H. Meugnier, F. Grimont, P. A. D. Grimont, C. Nervi, and J. Fleurette, Int. J. Syst. Bacteriol. 38:168-172, 1988). There are few data in the literature on its pathogenicity. We report two cases in which its role as an opportunistic nosocomial appears to be incontestable.

Cross Infection↗

[A 3-year evaluation of systematic research on Salmonella, Shigella, Campylobacter and Yersinia at a Montpellier hospital].

This work aims at assessing the prevalence of four bacterial genus that are the most frequently involved in infectious diarrhoea, among patients usually kept apart from this type of pathology (there is not a department of Digestive Tract Diseases, of Infectious Diseases, of Pediatry). Among 3.626 stools received in our laboratory from 1.163 patients, 12 strains of Campylobacter, 11 strains of Salmonella and only one strain of Yersinia were isolated. No strain of Shigella was found. Of the 12 strains of Campylobacter, 6 were found in patients in the department of Hematology. The effect of Campylobacter upon immunocompromised hosts and/or during decontamination of the digestive tract is discussed. Of the 11 strains of Salmonella that were isolated, we didn't notice any actual predominance of one of the species. Finally the scarcity of Yersinia in spite of twofold patterns of enriching is commented upon.

Adult↗

[Chronic diarrhea caused by Campylobacter jejuni in a patient with AIDS].

We report a case of C. jejuni chronic diarrhea in a homosexual man with AIDS. The antibiotic susceptibility of the bacteria was about normal for the species. Investigating specific immunity, we observed the presence of anti-C. jejuni IgG and the absence of anti-C. jejuni IgA. These findings concord with the hypothesis that specific IgA are necessary for C. jejuni clearance from the digestive tract.

Acquired Immunodeficiency Syndrome↗

[Course of the resistance of Staphylococcus aureus to pefloxacin. A study based on 782 strains isolated in 1985 and 1986].

We studied the evolution of the resistance of Staphylococcus aureus to pefloxacin during 1985 and 1986 in eight hospital units. The pefloxacin resistant Staphylococcus aureus, which amounted to 8.9% in 1985 reached 27% in 1986. They are found mainly among the methicillin-resistant Staphylococcus. There is no obvious relationship between this resistance and the consumption of pefloxacin in each of the units.

Drug Resistance, Microbial↗