Acute care for patients exposed to a chemical attack: protocol for an international multicentric observational study.

INTRODUCTION: The use of weapons of mass destruction against civilian populations is of serious concern to public health authorities. Chemical weapons are of particular concern. A few studies have investigated medical responses in prehospital settings in the immediate aftermath of a chemical attack, and they were limited by the paucity of clinical data. This study aims to describe the acute management of patients exposed to a chemical attack from the incident site until their transfer to a medical facility. METHODS AND ANALYSIS: This international multicentric observational study addresses the period from 1970 to 2036. An online electronic case report form was created to collect data; it will be hosted on the Biomedical Telematics Laboratory Platform of the Quebec Respiratory Health Research Network. Participating medical centres and their clinicians are being asked to provide contextual and clinical information, including the use of protective equipment and decontamination capabilities for the medical evacuation of the patient from the incident site of the chemical attack to the moment of admission at the medical facility. In brief, variables are categorised as follows: (1) chemical exposure (threat); (2) prehospital and hospital/medical facility capabilities (staffing, first aid, protection, decontamination, disaster plans and medical guidelines); (3) clinical interventions before hospital admission, including the use of protection and decontamination and (4) outcomes (survivability vs mortality rates). Judgement criteria focus on decontamination drills applied to any of the patient's conditions. ETHICS AND DISSEMINATION: The Sainte-Justine Research Centre Ethics Committee approved this multicentric study and is acting as the main evaluating centre. Study results will be disseminated through various means, including conferences, indexed publications in medical databases and social media. TRIAL REGISTRATION NUMBER: NCT05026645.

Breaking down population density into different components to better understand its spatial variation.

BACKGROUND: Population size and densities are key parameters in both fundamental and applied ecology, as they affect population resilience to density-dependent processes, habitat changes and stochastic events. Efficient management measures or species conservation programs thus require accurate estimates of local population densities across time and space, especially for continuously distributed species. For social species living in groups, population density depends on different components, namely the number of groups and the group size, for which relative variations in space may originate from different environmental factors. Whether resulting spatial variations in density are mostly triggered by one component or the other remains poorly known. Here, we aimed at determining the magnitude of the spatial variation in population densities of a social, group-living species, i.e. the European badger Meles meles, in 13 different sites of around 50 km2 across France, to decipher whether sett density, group size or proportion of occupied sett variation is the main factor explaining density variation. Besides the intrinsic factors of density variation, we also assessed whether habitat characteristics such as habitat fragmentation, urbanisation, and resource availability, drove both the spatial variation of density components and local population densities. RESULTS: We proposed a new standardised approach combining use of multiple methods, namely distance sampling for estimating the density of occupied sett clusters, i.e. group density, and camera and hair trapping for genetic identification to determine the mean social group size. The density of adult badgers was on average 3.8 per km2 (range 1.7-7.9 per km2) and was positively correlated with the density of sett clusters. The density of adult badgers per site was less related to the social group size or to the proportion of occupied sett clusters. Landscape fragmentation also explained the spatial variation of adult badger density, with highly fragmented landscapes supporting lower adult densities. Density components were linked differently to environmental variables. CONCLUSIONS: These results underline the need to break down population density estimates into several components in group-living species to better understand the pattern of temporal and spatial variation in population density, as different components may vary due to different ecological factors.

[Focus on clinical and pathological management of conjunctival melanocytic tumors]. / Mise au point sur la prise en charge clinique et anatomo-pathologique des tumeurs mélanocytaires de la conjonctive.

Conjunctival-pigmented tumors are rare, but they are one of the most commonly encountered by the pathologist working with the department of ophthalmology. Nevus and melanoma can be encountered and have some histological difference compared to their cutaneous counterpart. Primary acquired melanosis (PAM) is a conjunctival specific entity. This clinical term includes several histological lesions ranging from benignity to melanoma precursor lesion. Histologic examination determines the therapy and the risk of progression to melanoma. We present here a histopathological, clinical and therapeutic synthesis of conjunctival-pigmented lesions, emphasizing the importance of a good understanding between clinicians and pathologists.

Acute Brachial Radiculoplexopathy and Giant Cell Arteritis.

INTRODUCTION: Giant cell arteritis (GCA), a vasculitis involving large-sized and medium-sized vessels (which most commonly involves temporal arteries), is easily recognized in older patients presenting with headache, scalp tenderness, and raised inflammatory markers. Neurological complications (either central or peripheral) are classically described in GCA. CASE REPORT: We report the case of an 85-year-old woman with bilateral acute brachial radiculoplexopathy, a rare neurological complication of GCA. She also presented right oculomotor palsy (with ptosis) and raised inflammatory markers, but she did not complain of the other classic cranial symptoms of the disease. We compare this case with 16 similar cases reported in the medical literature. CONCLUSIONS: In assessing a patient over 50 years of age with unexplained (unilateral or bilateral) brachial radiculoplexopathy (especially if C5-C6 nerve roots are affected) and elevated inflammatory markers, we would recommend specific enquiries with regard to the manifestations of GCA. The purpose is to reduce the risk of missing the wider spectrum of this condition and minimize the subsequent risk for disability of this treatable disease.

Primary diffuse leptomeningeal gliomatosis: do we miss the diagnosis?

Primary diffuse leptomeningeal gliomatosis (PDLG) is characterized by diffuse infiltration of the leptomeningeal space by neoplastic glial cells without evidence of intra-parenchymatous primary tumor. We report a case of PDLG in a 68-year-old man, who died 1 month after onset of symptoms. The diagnosis was made on autopsy data. We discuss the particularities of this entity, which is not registered in the WHO classification of tumors of the central nervous system (2016). In case of an unexplained inflammatory meningeal process and in the presence of atypical cells in the cerebrospinal fluid, PDLG needs to be considered. This diagnosis of PDLG has to be confirmed by meningeal imaging-guided biopsy, which must be repeated if necessary.
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Anterior capsule contraction treated by femtosecond laser capsulotomy.

PURPOSE: To describe a new method to treat severe anterior capsule contraction using a femtosecond laser anterior capsulotomy. METHODS: Case report. RESULTS: A 48-year-old woman with a history of myotonic dystrophy experienced a severe contraction of the anterior capsule following an uneventful phacoemulsification cataract surgery with a hydrophilic acrylic intraocular lens implanted in the capsular bag. A femtosecond laser anterior capsulotomy was performed using a non-applanating fluid-filled interface. The spectral-domain optical coherence tomography imaging system associated with the laser enabled precise centration and location of the capsulotomy with a posterior cut located between the anterior surface of the intraocular lens and the anterior capsule inner surface. The free-floating capsulotomy was easily removed after the laser procedure, and 8 days postoperatively visual acuity recovered and myopic shift regressed with an intraocular lens centered in the capsular bag. CONCLUSIONS: Femtosecond laser assisted by a high-resolution imaging system appears to be a safe and efficient treatment for severe anterior capsule contraction.

Forecasting the effects of land use scenarios on farmland birds reveal a potential mitigation of climate change impacts.

Climate and land use changes are key drivers of current biodiversity trends, but interactions between these drivers are poorly modeled, even though they could amplify or mitigate negative impacts of climate change. Here, we attempt to predict the impacts of different agricultural change scenarios on common breeding birds within farmland included in the potential future climatic suitable areas for these species. We used the Special Report on Emissions Scenarios (SRES) to integrate likely changes in species climatic suitability, based on species distribution models, and changes in area of farmland, based on the IMAGE model, inside future climatic suitable areas. We also developed six farmland cover scenarios, based on expert opinion, which cover a wide spectrum of potential changes in livestock farming and cropping patterns by 2050. We ran generalized linear mixed models to calibrate the effects of farmland cover and climate change on bird specific abundance within 386 small agricultural regions. We used model outputs to predict potential changes in bird populations on the basis of predicted changes in regional farmland cover, in area of farmland and in species climatic suitability. We then examined the species sensitivity according to their habitat requirements. A scenario based on extensification of agricultural systems (i.e., low-intensity agriculture) showed the greatest potential to reduce reverse current declines in breeding birds. To meet ecological requirements of a larger number of species, agricultural policies accounting for regional disparities and landscape structure appear more efficient than global policies uniformly implemented at national scale. Interestingly, we also found evidence that farmland cover changes can mitigate the negative effect of climate change. Here, we confirm that there is a potential for countering negative effects of climate change by adaptive management of landscape. We argue that such studies will help inform sustainable agricultural policies for the future.

Interface fluid syndrome after bioptics.

PURPOSE: To report an unusual case of interface fluid syndrome after refractive surgery. METHODS: A 37-year-old man with high myopia underwent a planned bioptics procedure including creation of a corneal flap using a mechanical microkeratome and concurrent anterior chamber phakic intraocular lens implantation; excimer laser ablation was not performed at this time. RESULTS: Postoperatively, the patient developed corneal edema and was referred to our department. Interface fluid syndrome was confirmed using optical coherence tomography; the mechanism was due to endothelial cell pump dysfunction. CONCLUSIONS: This is the first report to document interface fluid syndrome following a planned bioptics procedure.

Protein aggregation in the aging retina.

The age-related altered expression of neuron-related proteins as seen in other regions of the central nervous system is expected in the aging retina. Using immunohistochemical techniques, we characterized the distribution and aggregation of tau, ßA4-amyloid, α-synuclein, and ubiquitin in human retina obtained from 19 enucleated eyes of patients aged 49 to 87 years and correlated the findings with the ages. Using a phosphorylation-independent antibody, tau aggregates were observed within the cytoplasm of several photoreceptor cells, and there was a positive correlation between age and the number of tau-positive ganglionic cells. Tau deposits were immunonegative with a phosphorylation-dependent antibody. We did not observe ßA4-amyloid in subretinal pigment epithelium deposits or in neuroepithelial layers. α-Synuclein and ubiquitin inclusions were found in the inner nuclear layer, and there was colocalization of these proteins. The proportion of patients displaying such α-synuclein and/or ubiquitin intracytoplasmic inclusions was significantly higher with aging. The presence of ubiquitin deposits within drusen was remarkable, but diffuse ubiquitin aggregates between the retinal pigment epithelium and Bruch membrane were also noticed. These results indicate that protein aggregation in the retina increases with aging and that tau, α-synuclein, and ubiquitin should be the subjects of future investigations.

Keratoconus associated with Williams-Beuren syndrome: first case reports.

PURPOSE: To report two memorable clinical comorbid cases of Williams-Beuren syndrome (WBS) associated with keratoconus (KC). WBS is known to be an abnormal systemic development caused by a microdeletion of contiguous genes in chromosome 7q11.23, which includes the elastin gene. KC is currently suspected to have a genetic origin but the responsible gene has not been clearly identified. METHODS: KC and WBS is described for two cases. Risk factors for KC were investigated by interviewing parents, and WBS was confirmed by fluorescence in-situ hybridization (FISH). Histological analysis with Orcein (coloring specific to elastin) on the receiver corneal button of patient 1 was carried out. RESULTS: Because of the rarity of both pathologies and the absence of other risk factors for developing keratoconus, we considered a possible genetic link. The association had never been reported in the literature. The first histological investigation could not confirm the presence of abnormal elastin in the cornea, but another gene could be responsible. CONCLUSION: This report highlights the first cases of this association. Further histological and cytogenetic investigation on the deletion should be interesting in order to argue a possible physiopathological or genomic link.

Histopathological findings after intracorneal ring segment implantation in keratoconic human corneas.

PURPOSE: To evaluate histopathological changes induced in keratoconic corneas after implantation of Intacs intracorneal ring segments (Addition Technology, Inc.). SETTING: Departments of Ophthalmology and Pathology, Hospital Pellegrin, Bordeaux, France. METHODS: This retrospective study included 8 keratoconic, contact-lens-intolerant eyes of 8 patients who had penetrating keratoplasty (PKP) after removal of Intacs inserts because of a poor refractive outcome or insert extrusion. Light microscopy was performed on all specimens after conventional staining. Immunohistochemistry was performed to identify cell types located next to the tunnel using AE1/AE3 cytokeratins, CD34, vimentin, collagen IV, and alpha-smooth muscle actin monoclonal antibodies. RESULTS: Conventional histology showed hypoplasia of the epithelium immediately surrounding the channel. There was no evidence of an inflammatory response or foreign-body granuloma. Keratocyte density was decreased above and below the tunnel, and collagen IV synthesis was seen in the scar area. All samples stained negatively with alpha-smooth muscle actin, indicating that myofibroblasts were not present. These changes were no longer visible when PKP was performed more than 6 months after Intacs explantation. CONCLUSIONS: Intacs induced keratocyte apoptosis, probably through a switch to a collagenous synthetic phenotype. Although histological changes seem to be entirely reversible after implant removal, longer follow-up is necessary to determine whether they accelerate corneal thinning and keratoconus progression via apoptosis and release of metalloprotease.

Penetrating corneal transplant with inadvertent corneal button inversion.

PURPOSE: To report a penetrating corneal transplant in which there was inadvertent inversion of the corneal button. DESIGN: Interventional case report. METHODS: A 48-year-old man with lattice corneal dystrophy had a third penetrating keratoplasty in the right eye 3 years after the second procedure and 2 years following renal transplantation. RESULTS: Histologic examination of the corneal button from the second penetrating keratoplasty disclosed inadvertent corneal graft inversion. Survival epithelium from the donor in the anterior chamber may be explained by the ocular anterior chamber-associated immune deviation or by the patient's systemic cyclosporine A (CsA) treatment after renal transplantation. CONCLUSIONS: Histologically proven corneal button inversion is a rare cause of corneal graft failure.