Modified Corneal Collagen Crosslinking (CXL) Reduces Corneal Edema and Diurnal Visual Fluctuations in Fuchs' Dystrophy

Purpose: Crosslinking of corneal collagen with riboflavin and ultraviolet-A irradiation (CXL) induces crosslinks within and between collagen fibers. CXL increases corneal biomechanical and biochemical stability and is currently used clinically to treat keratectasia. CXL also significantly reduces the stromal swelling capacity. We investigated whether a modified CXL treatment protocol would be beneficial in early Fuchs' dystrophy with various degrees of corneal edema and diurnal variations in visual acuity. Methods: CXL was performed as published previously with the following modification: in cases where the stroma was thicker than 450 µm after abrasion and 30 minutes of instillation of isoosmolar riboflavin solution, glycerol 70% solution was applied every 5 seconds for two minutes, and central corneal thickness (CCT) was measured using ultrasound pachymetry. Glycerol 70% solution was administered repeatedly until the target corneal thickness of 370-430 µm was reached. During irradiation, CCT was monitored by ultrasound pachymetry every five minutes and glycerol 70% solution was applied, if necessary. Results: Three eyes in two patients were treated using the modified CXL protocol. Representative case: a 50-year-old woman with Fuchs' dystrophy and a history of 3 years of diurnal visual fluctuations was referred to us in March 2008. Preoperative best spectacle-corrected visual acuity (BSCVA) was 20/50. We performed modified CXL in the left eye. At one month after CXL, Scheimpflug analysis of CCT showed a reduction of more than 100 µm, and the Corneal Thickness Spatial Profile (CTSP) and Percentage of Increase in Thickness (PIT) showed a regularization of the "flattening" typical for Fuchs' dystrophy. Accordingly, diurnal analysis of corneal thickness showed a distinct postoperative reduction in CCT at all time points measured. At one month after CXL, the patient reported a reduction of diurnal visual fluctuations and we measured an increase in BSCVA to 20/32. The patient showed stable topographical and visual acuity at the three months follow-up. Conclusions: We saw a distinct reduction in CCT, an improvement of the corneal thickness spatial profile (CTSP) and an increase in BSCVA at one month after treatment, which remained stable at the three months follow-up. Patients with early Fuchs' dystrophy and disturbing diurnal visual fluctuations represent a novel application for CXL. Although CXL may not prevent the outcome of the dystrophy, it may increase the patients' visual comfort until keratoplasty becomes necessary.

Neonatal treatment with recombinant ectodysplasin prevents respiratory disease in dogs with X-linked ectodermal dysplasia.

Patients with defective ectodysplasin A (EDA) have X-linked hypohidrotic ectodermal dysplasia (XLHED; OMIM#305100), a condition comprising hypotrichosis, inability to sweat, abnormal teeth, and frequent pulmonary infections. The XLHED dogs show the same clinical signs as humans with the disorder, including frequent respiratory infections that can be fatal. The respiratory disease in humans and dogs is thought to be due to the absence of tracheal and bronchial glands which are a vital part of the mucociliary clearance mechanism. In our XLHED model, the genetically missing EDA was replaced by postnatal intravenous administration of recombinant EDA resulting in long-term, durable corrective effect on adult, permanent dentition. After treatment with EDA, significant correction of the missing tracheal and bronchial glands was achieved in those dogs that received higher doses of EDA. Moreover, successful treatment resulted in the presence of esophageal glands, improved mucociliary clearance, and the absence of respiratory infection. These results demonstrate that a short-term treatment at a neonatal age with a recombinant protein can reverse a developmental disease and result in vastly improved quality of life.

Respiratory surveillance of patients with Duchenne and Becker muscular dystrophy.

Duchenne muscular dystrophy is is the most common form of the childhood muscular dystrophies. It follows a predictable clinical course marked by progressive skeletal muscle weakness, lost of ambulation before teen-age and death in early adulthood secondary to respiratory or cardiac failure. Becker muscular dystrophy is less common and has a milder clinical course but also results in respiratory and cardiac failure.Altough recent advances in respiratory care and new technologies have improved the outlook many patients already received only a traditional non-interventional approach. The aims of this work are: to analyse the pathophysiology and natural history of respiratory function in these diseases, to descript their clinical manifestations, to present the diagnostics tools and to provide recommendations for an adequated respiratory care in this particular population based on the updated literature referenced.

β-Glucan Antigenemia Anticipates Diagnosis of Blood Culture-Negative Intraabdominal Candidiasis.

Rationale: Life-threatening intraabdominal candidiasis (IAC) occurs in 30 to 40% of high-risk surgical intensive care unit (ICU) patients. Although early IAC diagnosis is crucial, blood cultures are negative, and the role of Candida score/colonization indexes is not established. Objectives: The aim of this prospective Fungal Infection Network of Switzerland (FUNGINOS) cohort study was to assess accuracy of 1,3-β-d-glucan (BG) antigenemia for diagnosis of IAC. Methods: Four hundred thirty-four consecutive adults with abdominal surgery or acute pancreatitis and ICU stay 72 hours or longer were screened: 89 (20.5%) at high risk for IAC were studied (68 recurrent gastrointestinal tract perforation, 21 acute necrotizing pancreatitis). Diagnostic accuracy of serum BG (Fungitell), Candida score, and colonization indexes was compared. Measurements and Main Results: Fifty-eight of 89 (65%) patients were colonized by Candida; 29 of 89 (33%) presented IAC (27 of 29 with negative blood cultures). Nine hundred twenty-one sera were analyzed (9/patient): median BG was 253 pg/ml (46-9,557) in IAC versus 99 pg/ml (8-440) in colonization (P < 0.01). Sensitivity and specificity of two consecutive BG measurements greater than or equal to 80 pg/ml were 65 and 78%, respectively. In recurrent gastrointestinal tract perforation it was 75 and 77% versus 90 and 38% (Candida score ≥ 3), 79 and 34% (colonization index ≥ 0.5), and 54 and 63% (corrected colonization index ≥ 0.4), respectively. BG positivity anticipated IAC diagnosis (5 d) and antifungal therapy (6 d). Severe sepsis/septic shock and death occurred in 10 of 11 (91%) and 4 of 11 (36%) patients with BG 400 pg/ml or more versus 5 of 18 (28%, P = 0.002) and 1 of 18 (6%, P = 0.05) with BG measurement less than 400 pg/ml. β-Glucan decreased in IAC responding to therapy and increased in nonresponse. Conclusions: BG antigenemia is superior to Candida score and colonization indexes and anticipates diagnosis of blood culture-negative IAC. This proof-of-concept observation in strictly selected high-risk surgical ICU patients deserves investigation of BG-driven preemptive therapy.

Generation and characterization of function-blocking anti-ectodysplasin A (EDA) monoclonal antibodies that induce ectodermal dysplasia.

Development of ectodermal appendages, such as hair, teeth, sweat glands, sebaceous glands, and mammary glands, requires the action of the TNF family ligand ectodysplasin A (EDA). Mutations of the X-linked EDA gene cause reduction or absence of many ectodermal appendages and have been identified as a cause of ectodermal dysplasia in humans, mice, dogs, and cattle. We have generated blocking antibodies, raised in Eda-deficient mice, against the conserved, receptor-binding domain of EDA. These antibodies recognize epitopes overlapping the receptor-binding site and prevent EDA from binding and activating EDAR at close to stoichiometric ratios in in vitro binding and activity assays. The antibodies block EDA1 and EDA2 of both mammalian and avian origin and, in vivo, suppress the ability of recombinant Fc-EDA1 to rescue ectodermal dysplasia in Eda-deficient Tabby mice. Moreover, administration of EDA blocking antibodies to pregnant wild type mice induced in developing wild type fetuses a marked and permanent ectodermal dysplasia. These function-blocking anti-EDA antibodies with wide cross-species reactivity will enable study of the developmental and postdevelopmental roles of EDA in a variety of organisms and open the route to therapeutic intervention in conditions in which EDA may be implicated.

Candidoses en réanimation [Candidiasis and intensive care patients]

Le développement dune candidose invasive est une complication hospitalière particulièrement redoutée en raison de sa mortalité élevée, comparable à celle du choc septique (40 %-60 %). La candidémie survient chez 0,05 % des patients hospitalisés, mais touche près de 1 % de ceux séjournant en réanimation, et est responsable de 5 à 10 % des bactériémies nosocomiales. Bien quune proportion élevée de patients hospitalisés soient colonisés par des levures du genre Candida, seule une minorité développe une candidose sévère. Celle-ci est toutefois difficile à diagnostiquer : les signes évocateurs dune dissémination ne surviennent habituellement que tardivement. Un traitement empirique précoce ou préemptif pourrait améliorer le pronostic, mais pour des raisons tant épidémiologiques quéconomiques, un tel traitement ne peut être appliqué à tous les patients à risque de développer une candidose sévère. Chez les patients présentant des facteurs de risque, la pratique de cultures de surveillance systématiques permet de déceler le développement dune colonisation et d'en quantifier le degré, de manière à ne débuter un traitement préemptif que lorsque lindex de colonisation dépasse un seuil critique prédictif d'infection secondaire. Ces éléments physiopathologiques et la mise à disposition des dérivés triazolés moins toxiques que l'amphotéricine B ont permis l'application de traitements prophylactiques. Chez les patients immunosupprimés, la généralisation de cette approche a été incriminée comme lun des éléments déterminant de lémergence dinfections à Candida non albicans dont le pronostic est moins favorable. Pour les patients de réanimation, une stricte limitation aux groupes soigneusement identifiés comme étant à risque élevé et chez lesquels lefficacité de la prophylaxie a pu être démontrée doit contribuer à limiter cet impact épidémiologique défavorable.

The expansion of 300 CTG repeats in myotonic dystrophy transgenic mice does not induce sensory or motor neuropathy.

Although many studies have been carried out to verify the involvement of the peripheral nervous system (PNS) in dystrophia myotonica (DM1) patients, the results remain controversial. The generation of DM1 transgenic mice displaying the human DM1 phenotype provides a useful tool to investigate the type and incidence of structural abnormalities in the PNS. In the present study, the morphological and morphometric analysis of semi-thin sections of sciatic and sural nerves, lumbar dorsal root ganglia (DRG) and lumbar spinal cords revealed that in DM1 transgenic mice carrying 300 CTG repeats, there is no change in the number and diameter of myelinated axons compared to wild type. Only a non-significant reduction in the percentage of thin myelinated axons was detected in electron micrographs of ultra-thin sciatic nerve sections. Analysis of the number of neurons did not reveal a loss in number of either sensory neurons in the lumbar DRG or motor neurons in the lumbar spinal cord in these DM1 mice. Furthermore, in hind limb muscle sections, stained with a neurofilament antibody and alpha-bungarotoxin, the intramuscular axon arborization appeared normal in DM1 mice and undistinguishable from that in wild-type mice. Moreover, in DM1 mice, there was no irregularity in the structure or an increase in the endplate area. Also statistical analysis did not show an increase in endplate density or in the concentration of acetylcholine receptors. Altogether, these results suggest that 300 CTG repeats are not sufficient to induce axonopathy, demyelination or neuronopathies in this transgenic mouse model.

Deposits of transforming growth factor-beta-induced protein in granular corneal dystrophy type II after LASIK.

PURPOSE: To analyze components of the deposits in the corneal flap interface of granular corneal dystrophy type II (GCD II) patients after laser in situ keratomileusis (LASIK). METHODS: Four corneal GCD II specimens displaying disease exacerbation after LASIK were analyzed. Three of these specimens included the recipient corneal button after penetrating keratoplasty or deep lamellar keratoplasty for advanced GCD II after LASIK. The fourth specimen, a similar case of GCD II after LASIK, included the amputated corneal flap. Specimens were processed for histopathologic and immunohistochemical analyses. RESULTS: Corneal stromal deposits in the LASIK flaps of all specimens were stained with 3 anti-transforming growth factor-beta-induced protein (TGFBIp) antibodies. The deposits displayed bright red color staining with Masson trichrome; however, negative staining was seen with Congo red, suggesting that hyaline is the main component localizing to the TGFBIp deposits rather than amyloid. CONCLUSIONS: Amorphous granular material deposited along the interface of the LASIK flap in GCD II corneas is composed mainly of hyaline deposits.

Retinal Dystrophy In The Oculo-auricular Syndrome Due to HMX1 Mutation.

Purpose: To report on the clinical and electrophysiological findings in a patient with oculo-auricular syndrome due to HMX1 mutation, with a follow-up of 12 years. Background: Oculo-auricular syndrome (MIM: 612109) is a rare developmental recessive condition affecting the eye and external ear that results from a mutation in the HMX1 gene. Previously described ocular abnormalities include bilateral microcornea, posterior synechiae, cataract, chorioretinal colobomas and rod-cone dystrophy. Methods: Retrospective chart review of an affected boy followed over a period of 12 years who had serial complete ophthalmologic examinations, fundus photographs, Goldmann perimetry and full-field electroretinograms (ERG). Results: Initial ERG tracings revealed generalized rod more than cone dysfunction. Thereafter, a rapid deterioration in rod and cone function was detected on follow up ERGs. Conclusion: The retinal degeneration in the recessively inherited oculo-auricular syndrome is a progressive rod-cone dystrophy. Visual prognosis is guarded considering the progressive nature of the retinal dystrophy in early infancy.

Fluconazole prophylaxis prevents intra-abdominal candidiasis in high-risk surgical patients.

OBJECTIVE: To evaluate the efficacy and safety of intravenous fluconazole for the prevention of intra-abdominal Candida infections in high-risk surgical patients. DESIGN: Randomized, prospective, double-blind, placebo-controlled study. SETTING: Two university-affiliated hospitals in Switzerland. PATIENTS: Forty-nine surgical patients with recurrent gastrointestinal perforations or anastomotic leakages. INTERVENTIONS: Prophylaxis with intravenous fluconazole (400 mg per day) or placebo continued until resolution of the underlying surgical condition. MEASUREMENTS AND MAIN RESULTS: Patients were evaluated daily, and specimens for culture were obtained three times per week during prophylaxis. The primary study end points were the frequency of and the time to intra-abdominal Candida infections. Secondary end points were the frequency of candidiasis (intra-abdominal and extra-abdominal) and the emergence or persistence of Candida colonization. Among patients who were not colonized at study entry, Candida was isolated from surveillance cultures during prophylaxis in 15% of the patients in the fluconazole group and in 62% of the patients in the placebo group (relative risk, 0.25; 95% confidence interval, 0.07 to 0.96; p = .04). Candida peritonitis occurred in one of 23 patients (4%) who received fluconazole and in seven of 20 patients (35%) who received placebo (relative risk, 0.12; 95% confidence interval, 0.02 to 0.93; p = .02). In addition, one catheter-related Candida albicans sepsis occurred in a fluconazole-treated patient. Thus, overall, candidiasis developed in two fluconazole patients and seven placebo patients (relative risk, 0.25; 95% confidence interval, 0.06 to 1.06; p = .06). C. albicans accounted for 87% of the Candida species isolated before or during prophylaxis, and all C. albicans strains were susceptible to fluconazole. Fluconazole was well tolerated, and adverse events occurred at similar frequencies in both treatment groups. CONCLUSIONS: Fluconazole prophylaxis prevents colonization and invasive intra-abdominal Candida infections in high-risk surgical patients.

A dystroglycan mutation associated with limb-girdle muscular dystrophy.

Dystroglycan, which serves as a major extracellular matrix receptor in muscle and the central nervous system, requires extensive O-glycosylation to function. We identified a dystroglycan missense mutation (Thr192→Met) in a woman with limb-girdle muscular dystrophy and cognitive impairment. A mouse model harboring this mutation recapitulates the immunohistochemical and neuromuscular abnormalities observed in the patient. In vitro and in vivo studies showed that the mutation impairs the receptor function of dystroglycan in skeletal muscle and brain by inhibiting the post-translational modification, mediated by the glycosyltransferase LARGE, of the phosphorylated O-mannosyl glycans on α-dystroglycan that is required for high-affinity binding to laminin.

Mutations leading to X-linked hypohidrotic ectodermal dysplasia affect three major functional domains in the tumor necrosis factor family member ectodysplasin-A.

Mutations in the epithelial morphogen ectodysplasin-A (EDA), a member of the tumor necrosis factor (TNF) family, are responsible for the human disorder X-linked hypohidrotic ectodermal dysplasia (XLHED) characterized by impaired development of hair, eccrine sweat glands, and teeth. EDA-A1 and EDA-A2 are two splice variants of EDA, which bind distinct EDA-A1 and X-linked EDA-A2 receptors. We identified a series of novel EDA mutations in families with XLHED, allowing the identification of the following three functionally important regions in EDA: a C-terminal TNF homology domain, a collagen domain, and a furin protease recognition sequence. Mutations in the TNF homology domain impair binding of both splice variants to their receptors. Mutations in the collagen domain can inhibit multimerization of the TNF homology region, whereas those in the consensus furin recognition sequence prevent proteolytic cleavage of EDA. Finally, a mutation affecting an intron splice donor site is predicted to eliminate specifically the EDA-A1 but not the EDA-A2 splice variant. Thus a proteolytically processed, oligomeric form of EDA-A1 is required in vivo for proper morphogenesis.

Zapfen-Stäbchen-Dystrophie durch eine neue reinerbige RPE65-Mutation in Leberscher kongenitaler Amaurose Cone-Rod Dystrophy Caused by a Novel Homozygous RPE65 Mutation in Leber Congenital Amaurosis.

Background: The aim of this study was to describe an unexpected phenotype in a family with Leber congenital amaurosis (LCA) due to a retinal pigment epithelium-specific protein 65 kDa (RPE65) homozygous mutation. History and Signs: We analyzed a family from Yemen in which 3 individuals were affected with LCA. Linkage analysis using markers flanking the known LCA genes was done, followed by direct sequencing of RPE65. Therapy and Outcome: Severe visual impairment and night blindness were observed during infancy. We observed photophobia only in the 8-year-old patient. The youngest affected had bilateral hyperopia of + 3.50 and visual acuity of 1/60. The oldest two had visual acuity limited to hand movements in the right eye (OD) and counting fingers in the left eye (OS) for the oldest and of 5/60 OD, 6/60 OS for the other. They showed disc pallor, attenuated vessels, white flecks in the retina mid-periphery and bull's eye maculopathy. ERGs of the oldest child were completely unresponsive. Genomic sequencing identified a novel homozygous missense mutation, IVS2-3C > G, in the second RPE65 intron. Conclusions: We identified a novel LCA-related homozygous RPE65 mutation associated with a severe clinical presentation including an early and severe cone dysfunction. This is in contrast with the presentation associated with other RPE65 mutations predominantly causing rod-cone dystrophy with residual visual function.

Invasive candidiasis as a cause of sepsis in the critically ill patient.

Invasive fungal infections are an increasingly frequent etiology of sepsis in critically ill patients causing substantial morbidity and mortality. Candida species are by far the predominant agent of fungal sepsis accounting for 10% to 15% of health-care associated infections, about 5% of all cases of severe sepsis and septic shock and are the fourth most common bloodstream isolates in the United States. One-third of all episodes of candidemia occur in the intensive care setting. Early diagnosis of invasive candidiasis is critical in order to initiate antifungal agents promptly. Delay in the administration of appropriate therapy increases mortality. Unfortunately, risk factors, clinical and radiological manifestations are quite unspecific and conventional culture methods are suboptimal. Non-culture based methods (such as mannan, anti-mannan, β-d-glucan, and polymerase chain reaction) have emerged but remain investigational or require additional testing in the ICU setting. Few prophylactic or pre-emptive studies have been performed in critically ill patients. They tended to be underpowered and their clinical usefulness remains to be established under most circumstances. The antifungal armamentarium has expanded considerably with the advent of lipid formulations of amphotericin B, the newest triazoles and the echinocandins. Clinical trials have shown that the triazoles and echinocandins are efficacious and well tolerated antifungal therapies. Clinical practice guidelines for the management of invasive candidiasis have been published by the European Society for Clinical Microbiology and Infectious Diseases and the Infectious Diseases Society of North America.