Benchmarking Visual Performance with Monofocal Intraocular Lenses with and without Enhanced Optical Properties in a Nighttime Driving Simulator Environment: A Proof-of-Concept Study. / Vergleich der Sehleistung mit monofokalen Intraokularlinsen mit und ohne verbesserte optische Eigenschaften in einem Nachtfahrsimulator: eine Proof-of-Concept-Studie.

BACKGROUND: The purpose of this study is to introduce a method for benchmarking intraocular lenses during driving activities under highly standardized conditions, specifically with regard to visual acuity (VA) and contrast sensitivity (CS). Therefore, patients with intraocular lens (IOL) implants ICB00 (Tecnis Eyhance, Johnson & Johnson, Santa Ana, CA, USA) vs. CNA0T0 (Clareon, Alcon Laboratories Inc., Fort Worth, TX, USA) were examined clinically and in a nighttime driving simulator. PATIENTS AND METHODS: Clinical tests for high (HCVA), low contrast (LCVA) distant VA, and mesopic CS were conducted in subjects at least 2 months after binocular IOL surgery (inclusion criteria: VA > 20/25, ophthalmologically normal, except cataract surgery). All patients completed a straight driving simulator route. VA, CS, and halo size were assessed binocularly during nighttime driving using eight-position Landolt Cs in four different locations and two (far and intermediate) distances. RESULTS: Results are presented as median/interquartile range: ICB00 data (corresponding CNA0T0 data are shown in brackets): 5 (6) subjects, aged 69.6/8.3 (71.1/13.0) years were enrolled. Clinical tests: logMAR HCVA 0.11/0.39 (0.00/0.51), logMAR LCVA 0.78/0.52 (0.80/0.54); logCS without glare 0.50/0.31 (0.30/0.65), logCS with glare 0.20/0.15 (0.20/0.5). Nighttime driving simulator: logMAR VA thresholds for right roadside, dashboard, navigation screen, and interior rear-view mirror were 0.50/0.06 (0.57/0.22), 0.81/0.07 (0.91/0.14), 0.80/0.17 (0.92/0.27), 0.50/0.11 (0.63/0.26); logCS thresholds were1.53/0.67 (1.00/0.81), 0.82/0.11 (0.61/0.19), 0.71/0.14 (0.50/0.15), 0.87/0.07 (0.81/0.11). Halo size: 5.40°/0.89° (5.88°/2.00°). CONCLUSIONS: Within a nighttime driving simulator environment, ICB00 exceeded CNA0T0 in median logMAR (VA) and logCS by 0.1 log unit at intermediate distances (dashboard, navigation screen). The clinical test for far and remote distances did not show a difference. These results confirm benefits of monofocal IOLs with enhanced optical properties for intermediate distances compared to conventional monofocal lenses within the target medium distance ranges.

[Level of knowledge and behavior regarding HIV prevention in a population of migrants]. / Niveau de connaissances et comportement en matière de prévention du VIH au sein d'une population de migrants.

In Geneva an HIV voluntary counselling and testing (VCT) consultation for migrants exists in a primary care center. A semi-structured questionnaire, was filled out during the VCT consultations. 650 questionnaires were analyzed. 82 % were asylum seekers. 30 % said they did not really understand how HIV is transmitted and 27 % cited erroneous modes of contamination. 78 % of women who did not use condoms regularly gave having a stable partner as the reason compared to 49 % for men. VCT is a great prevention tool : the counseling accompanying the test provides an opportunity to openly raise various risk practices and to personalize the information. However, this requires a suitable and affordable structure.

A Genève, une consultation de conseil et test volontaire du VIH (VCT, Voluntary Counselling and Testing) pour migrants existe dans une structure de médecine de premier recours. Un questionnaire semi-structuré, servant aussi de guide d'entretien, est rempli durant ces consultations VCT. 650 questionnaires ont été analysés. 82 % sont demandeurs d'asile. 30 % déclarent ne pas vraiment comprendre les modes de transmission du VIH et 27 % citent des modes de contamination erronés. 78 % des femmes n'utilisent pas le préservatif systématiquement, et mentionnent pour motif le partenaire stable contre 49 % pour les hommes. Le VCT constitue un outil de prévention idéal : l'entretien accompagnant le test permet de discuter ouvertement sur les différentes pratiques à risque et individualiser l'information. Cependant, cela nécessite une structure adaptée, accessible financièrement.

Dissociation between red and white stimulus perception: A perimetric quantification of protanopic color vision deficiencies.

SIGNIFICANCE: Horizontal visual field extension was assessed for red and white stimuli in subjects with protanopia using semi-automated kinetic perimetry. In contrast to a conventional anomaloscope, the "red/white dissociation ratio" (RWR) allows to describe protanopia numerically. For the majority of subjects with protanopia a restriction for faint red stimuli was found. PURPOSE: Comparing the horizontal visual field extensions for red and white stimuli in subjects with protanopia and those with normal trichromacy and assessing the related intra-subject intra-session repeatability. METHODS: The subjects were divided into groups with protanopia and with normal trichromacy, based on color vision testing (HMC anomaloscope, Oculus, Wetzlar/FRG). Two stimulus characteristics, III4e and III1e, according to the Goldmann-classification, were presented with semi-automated kinetic perimetry (Octopus 900 perimeter, Haag-Streit, Köniz/CH). They moved along the horizontal meridian, with an angular velocity of 3°/s towards the visual field center, starting from either the temporal or nasal periphery. If necessary, a 20° nasal fixation point offset was chosen to capture the temporal periphery of the visual field. For each condition the red/white dissociation ratio (RWR); Pat Appl. DPMA DRN 43200082D) between the extent of the isopter for red (RG610, Schott, Mainz/ FRG) and white stimuli along the horizontal meridian was determined. RESULTS: All data are listed as median/interquartile range: Five males with protanopia (age 22.1/4.5 years) and six males with normal trichromacy (control group, age 30.5/15.2 years) were enrolled. The RWR is listed for the right eye, as no clinically relevant difference between right and left eye occurred. Protanopes' RWR for mark III4e (in brackets: control group) was 0.941/0.013 (0.977/0.019) and for mark III1e 0.496/0.062 (0.805/0.051), respectively. CONCLUSIONS: In this exploratory "proof-of-concept study" red/white dissociation ratio perimetry is introduced as a novel technique aiming at assessing and quantifying the severity of protanopia. Further effort is needed to understand the magnitude of the observed red-/white dissociation and to extend this methodology to a wider age range of the sample and to anomalous trichromacies (protanomalia) with varying magnitude.

Functional complementation between the PDX1 vitamin B6 biosynthetic gene of Cercospora nicotianae and pdxJ of Escherichia coli.

The pathway for de novo vitamin B(6) biosynthesis has been characterized in Escherichia coli, however plants, fungi, archaebacteria, and most bacteria utilize an alternative pathway. Two unique genes of the alternative pathway, PDX1 and PDX2, have been described. PDX2 encodes a glutaminase, however the enzymatic function of the product encoded by PDX1 is not known. We conducted reciprocal transformation experiments to determine if there was functional homology between the E. coli pdxA and pdxJ genes and PDX1 of Cercospora nicotianae. Although expression of pdxJ and pdxA in C. nicotianae pdx1 mutants, either separately or together, failed to complement the pyridoxine mutation in this fungus, expression of PDX1 restored pyridoxine prototrophy to the E. coli pdxJ mutant. Expression of PDX1 in the E. coli pdxA mutant restored very limited ability to grow on medium lacking pyridoxine. We conclude that the PDX1 gene of the alternative B(6) pathway encodes a protein responsible for synthesis of the pyridoxine ring.

Involvement of dendritic cell subsets in the induction of oral tolerance and immunity.

Dendritic cells (DCs) play a central role in the generation of immune responses in the intestine. DCs induce differentiation and tolerance of T cells, and may have a direct role in B cell switching to IgA. Four distinct subsets of CD11c(+) DCs are present in murine Peyer's patches, which represent primary sites for the induction of mucosal T and B cell responses. Studies suggest that CD11b(+) DCs or plasmacytoid DCs may be specialized for the induction of regulatory T cells, and CD8alpha(+) DCs for the induction of clonal deletion in response to soluble oral antigen, while all DC subsets (including CD8alpha(-)/CD11b(-) DCs) may be involved in responses to pathogens. We are currently using reovirus type-1 Lang (TIL) to explore the role of DC populations in mucosal immunity in vivo, as oral administration of live T1L to mice induces strong mucosal and systemic antiviral immune responses, whereas oral administration of inactivated T1L results in tolerance to viral proteins. We found that primary infection with T1L occurs in epithelial cells of the PP follicle-associated epithelium, but that CD8alpha(-)/CD11b(-) DCs in the subepithelial dome region (SED) are loaded with T1L antigens in the absence of active DC infection. At least a portion of this antigen is associated with cell fragments from apoptotic epithelial cells, demonstrating that SED DCs cross-present antigens from apoptotic epithelial cells. In vitro, in contrast to exposure to several TLR-ligands or anti-CD40, exposure to T1L does not activate DCs to mature or to produce cytokines, despite clear loading of the DCs with viral antigens. These data suggest that T1L is taken up by a "silent" receptor on DCs, and that the induction of immunity to T1L is dependent on signals from non-DCs following active viral infection that induce DC maturation. Thus, the decision between tolerance and immunity to inactive and live virus, respectively, likely depends on whether there is active infection of epithelial cells by T1L, which results in the elaboration of molecules, such as cytokines, that induce DC maturation.