Neuropathie optique rétrobulbaire post-actinique [Post-actinic retrobulbar optic neuropathy]

BACKGROUND: Radiation optic neuropathy (RON) is a rare, unpredictable, late complication of radiotherapy secondary to obliterative endarteritis. Tumor recurrence has to be ruled out by a clinical and neuroradiological examination. METHODS: Five patients with RON were investigated by magnetic resonance imaging (MRI) during 1992. RESULTS: Radiation-induced lesions of the intracranial visual pathways were easily visible on MRI. Without Gadolinium, a sectorial swelling was detectable, which markedly enhanced with Gadolinium. Intracranial optic nerve was affected in 5/5 cases, optic chiasm in 3/5 cases, and optic tract in 2/5 cases. CONCLUSIONS: MRI is the examination of choice when RON is suspected: it will easily delineate the extent of the lesion, and compression/infiltration by a recurrent tumor will be formally ruled out. A segmental swelling of visual pathway with marked Gadolinium enhancement on MRI is highly suggestive of radionecrosis.

Polymorphism at a sex-linked transcription cofactor in European tree frogs (Hyla arborea): Sex-antagonistic selection or neutral processes?

Nascent sex chromosomes offer a unique opportunity to investigate the evolutionary fate of genesrecently trapped in non-recombining segments. A housekeeping gene (MED15) was recently shown to lie on the nascent sex-chromosomes of the European tree frog (Hyla arborea), with different alleles fixed on the X and the Y chromosomes. Here we document a polymorphism (glutamine deletion) in the X copy of the gene, and use population surveys and experimental crosses to test whether this polymorphism is neutral or maintained by sex-antagonistic selection. Tadpoles from parents of known genotypes revealed significant discrepancies from Mendelian inheritance, suggesting possible sex-antagonistic effects under laboratory conditions. Quantitatively, however, these effects did not meet the conditions for polymorphism maintenance. Furthermore, field estimates of female genotypic frequencies did not differ from Hardy-Weinberg equilibrium and allelic frequencies on the X chromosome did not differ between sexes. In conclusion, although sex antagonistic effects cannot be excluded given the laboratory conditions, the X-linked polymorphism under study appears neutral in the wild. Alternatively, sex-antagonistic selection might still account for the fixation of a male specific allele on the Y chromosome.

Development of a retrospective job exposure matrix for PCB-exposed workers in capacitor manufacturing

Objectives: Polychlorinated biphenyls (PCBs) are considered probable human carcinogens by the International Agency for Research on Cancer and one congener, PCB126, has been rated as a known human carcinogen. A period-specific job exposure matrix (JEM) was developed for former PCB-exposed capacitor manufacturing workers (n=12,605) (1938-1977). Methods: A detailed exposure assessment for this plant was based on a number of exposure determinants (proximity, degree of contact with PCBs, temperature, ventilation, process control, job mobility). The intensity and frequency of PCB exposures by job for both inhalation and dermal exposures, and additional chemical exposures were reviewed. The JEM was developed in nine steps: (1) all unique jobs (n=1,684) were assessed using (2) defined PCB exposure determinants; (3) the exposure determinants were used to develop exposure profiles; (4) similar exposure profiles were combined into categories having similar PCB exposures; (5) qualitative intensity (high-medium-low-baseline) and frequency (continuous-intermittent) ratings were developed, and (6) used to qualitatively rate inhalation and dermal exposure separately for each category; (7) quantitative intensity ratings based on available air concentrations were developed for inhalation and dermal exposures based on equal importance of both routes of exposure; (8) adjustments were made for overall exposure, and (9) for each category the product of intensity and frequency was calculated, and exposure in the earlier era was weighted. Results: A period-specific JEM modified for two eras of stable PCB exposure conditions. Conclusions: These exposure estimates, derived from a systematic and rigorous use of the exposure determinant data, lead to cumulative PCB exposure-response relationships in the epidemiological cancer mortality and incidence studies of this cohort. [Authors]

Contribution de la biomicroscopie ultrasonore au traitement conservateur des mélanomes de l'uvée antérieure [Contribution of ultrasound biomicroscopy to conservative treatment of anterior uveal melanoma]

BACKGROUND: Ultrasound Biomicroscopy (UBM) is a new ophthalmological imaging technique essentially designed for the study of the anterior eye segment. Over the last 10 months, we've evaluated its contribution to the conservative treatment of anterior uveal melanoma's by means of accelerated proton beam irradiation. MATERIAL: Using UBM, we have examined 55 cases of uveal melanoma's, whose anterior border was situated at 6 mm or less from the limbus and that were consequently treated by proton beam irradiation. RESULTS: The presumed tumoral origin was the ciliary body's pars plicata in 13 cases and the pars plana or the choroid in 42 cases, 17 of which presented a tumoral invasion of the pars plicata. A pars plana detachment anterior to or surrounding the anterior tumoral border, was present in 22 cases. The height of the tumor could only be measured by UBM if it was less than 2.5 mm. Information gathered using UBM have contributed to an improvement of the therapy plan in 32 cases. CONCLUSION: Because of the strong attenuation of the high frequency ultrasound signal, UBM can only be used for the examination of intra-ocular structures situated in direct neighbourhood to the global wall. Despite this technical limitation, ist contribution to the planning of the conservative treatment of anterior uveal melanoma's by proton beam irradiation has appeared to be considerable.

Intérêt de l'angiographie numérisée au vert d'indocyanine dans le diagnostic différentiel des tumeurs non pigmentées de la choroïde [Value of indocyanine green videoangiography in differential diagnosis of nonpigmented tumors of the choroid]

BACKGROUND: Indocyanine green video-angiography (ICG) is a recent examination technique, its possibilities and limitations as far as intraocular tumours are concerned, haven't been fully explored yet. MATERIAL AND METHODS: We have studied 50 cases of non-pigmented choroidal tumours, including 14 cases of choroidal hemangioma's, 11 cases of posterior uveal metastases and 25 cases of non-pigmented melanoma's. RESULTS: Characteristic images were obtained when examining choroidal hemangioma's and, until a certain point, posterior choroidal metastases. Non pigmented melanoma's on the contrary, presented a great variety of different indocyanine green angiographic pictures. CONCLUSION: Indocyanine green video-angiography (ICG) has a definite value in the differential diagnosis of non-pigmented posterior choroidal tumours.

Comparing Bone Microarchitecture by Trabecular Bone Score (TBS) in Caucasian American Women with and Without Osteoporotic Fractures.

Several cross-sectional studies have shown the ability of the TBS to discriminate between those with and without fractures in European populations. The aim of this study was to assess the ability of TBS to discriminate between those with and without fractures in a large female Caucasian population in the USA. This was a case-control study of 2,165 Caucasian American women aged 40 and older. Patients with illness or taking medications known to affect bone metabolism were excluded. Those in the fracture group (n = 289) had at least one low-energy fracture. BMD was measured at L1-L4, TBS calculated directly from the same DXA image. Descriptive statistics and inferential tests for difference were used. Univariate and multivariate logistic regression models were created to investigate possible association between independent variables and the status of fracture. Odds ratios per standard deviation decrease (OR) and areas under the ROC curve were calculated for discriminating parameters. Weak correlations were observed between TBS and BMD and between TBS and BMI (r = 0.33 and -0.17, respectively, p < 0.01). Mean age, weight, BMD and TBS were significantly different between control and fracture groups (all p ≤ 0.05), whereas no difference was noted for BMI or height. After adjusting for age, weight, BMD, smoking, and maternal and family history of fracture, TBS (but not BMD) remained a significant predictor of fracture: OR 1.28[1.13-1.46] even after adjustment. In a US female population, TBS again was able to discriminate between those with and those without fractures, even after adjusting for other clinical risk factors.

Origin of minority drug-resistant HIV-1 variants in primary HIV-1 infection.

BACKGROUND: Drug-resistant human immunodeficiency virus type 1 (HIV-1) minority variants (MVs) are present in some antiretroviral therapy (ART)-naive patients. They may result from de novo mutagenesis or transmission. To date, the latter has not been proven. METHODS: MVs were quantified by allele-specific polymerase chain reaction in 204 acute or recent seroconverters from the Zurich Primary HIV Infection study and 382 ART-naive, chronically infected patients. Phylogenetic analyses identified transmission clusters. RESULTS: Three lines of evidence were observed in support of transmission of MVs. First, potential transmitters were identified for 12 of 16 acute or recent seroconverters harboring M184V MVs. These variants were also detected in plasma and/or peripheral blood mononuclear cells at the estimated time of transmission in 3 of 4 potential transmitters who experienced virological failure accompanied by the selection of the M184V mutation before transmission. Second, prevalence between MVs harboring the frequent mutation M184V and the particularly uncommon integrase mutation N155H differed highly significantly in acute or recent seroconverters (8.2% vs 0.5%; P < .001). Third, the prevalence of less-fit M184V MVs is significantly higher in acutely or recently than in chronically HIV-1-infected patients (8.2% vs 2.5%; P = .004). CONCLUSIONS: Drug-resistant HIV-1 MVs can be transmitted. To what extent the origin-transmission vs sporadic appearance-of these variants determines their impact on ART needs to be further explored.

Les métastases orbitaires [Orbital metastasis]

PURPOSE: The purpose of this paper is to present our data and to provide some conclusions about the attitude that has to be chosen when metastasis of the orbit is suspected. PATIENTS AND METHODS: Between 1965 and 1994, 571 patients with non-traumatic orbital diseases were controlled in the department of ophthalmology of Lausanne. Thirty-four cases of metastasis of the orbit were selected, that is 24 females and 10 males, aged from 1 to 81 years. Tumors of the breast are the most frequent origin of this metastasis, followed by cutaneous melanomas and pulmonary tumors. Orbital metastasis was the first sign of a malignant process in 7 patients. The histologic diagnosis was confirmed in 15 patients. The type of treatment is presented herein and the follow-up of more than half of the cases is given. RESULTS AND CONCLUSION: Orbital metastasis can develop after a long time in patients who were previously treated for malignant tumors. In several cases, orbital metastasis was the first sign of a malignant process which starts to become general. This diagnosis has to be taken into account when a patient was treated earlier for a malignant tumor, and it is reasonable to propose a biopsy or an excision biopsy in every orbital pathology which was not confirmed by clinical or paraclinical investigations.

Women Sports Journalists in Switzerland: Between Assignment and Negotiation of Roles

In this paper, we analyze working experiences of female sports journalists in the French-speaking Swiss daily press. We draw on Bourdieu's theory of habitus and field to examine how structures of power shape these journalists' lives. Based on 27 semistructured interviews and observations in the field, we found that women journalists' work experiences depend on the relationship between their position in the field and their ethos and hexis. We identified three main strategies through which the women journalists negotiated their experiences: (1) conforming to the dominant male ethos (2) threatening the orthodoxy (3) resisting while hijacking the assigned role.

New gene functions in megakaryopoiesis and platelet formation.

Platelets are the second most abundant cell type in blood and are essential for maintaining haemostasis. Their count and volume are tightly controlled within narrow physiological ranges, but there is only limited understanding of the molecular processes controlling both traits. Here we carried out a high-powered meta-analysis of genome-wide association studies (GWAS) in up to 66,867 individuals of European ancestry, followed by extensive biological and functional assessment. We identified 68 genomic loci reliably associated with platelet count and volume mapping to established and putative novel regulators of megakaryopoiesis and platelet formation. These genes show megakaryocyte-specific gene expression patterns and extensive network connectivity. Using gene silencing in Danio rerio and Drosophila melanogaster, we identified 11 of the genes as novel regulators of blood cell formation. Taken together, our findings advance understanding of novel gene functions controlling fate-determining events during megakaryopoiesis and platelet formation, providing a new example of successful translation of GWAS to function.

Fishery-induced selection on an Alpine whitefish: quantifying genetic and environmental effects on individual growth rate

Size-selective fishing, environmental changes and reproductive strategies are expected to affect life-history traits such as the individual growth rate. The relative contribution of these factors is not clear, particularly whether size-selective fishing can have a substantial impact on the genetics and hence on the evolution of individual growth rates in wild populations. We analysed a 25-year monitoring survey of an isolated population of the Alpine whitefish Coregonus palaea. We determined the selection differentials on growth rate, the actual change of growth rate over time and indicators of reproductive strategies that may potentially change over time. The selection differential can be reliably estimated in our study population because almost all the fish are harvested within their first years of life, i.e. few fish escape fishing mortality. We found a marked decline in average adult growth rate over the 25 years and a significant selection differential for adult growth, but no evidence for any linear change in reproductive strategies over time. Assuming that the heritability of growth in this whitefish corresponds to what was found in other salmonids, about a third of the observed decline in growth rate would be linked to fishery-induced evolution. Size-selective fishing seems to affect substantially the genetics of individual growth in our study population.