PEDF-derived peptide protects against Amyloid-ß toxicity in vitro and prevents retinal dysfunction in rats.

Amyloid-beta (Aß), a family of aggregation-prone and neurotoxic peptides, has been implicated in the pathophysiology of age-related macular degeneration (AMD). We have previously shown that oligomeric and fibrillar species of Aß42 exerted retinal toxicity in rats, but while the consequences of exposure to amyloid were related to intracellular effects, the mechanism of Aß42 internalization in the retina is not well characterized. In the brain, the 67 kDa laminin receptor (67LR) participates in Aß-related neuronal cell death. A short peptide derived from pigment epithelium-derived factor (PEDF), formerly designated PEDF-335, was found to mitigate experimental models of ischemic retinopathy via targeting of 67LR. In the present study, we hypothesized that 67LR mediates the uptake of pathogenic Aß42 assemblies in the retina, and that targeting of this receptor by PEDF-335 may limit the internalization of Aß, thereby ameliorating its retinotoxicity. To test this assumption ARPE-19 cells in culture were incubated with PEDF-335 before treatment with fibrillar or oligomeric structures of Aß42. Immunostaining confirmed that PEDF-335 treatment substantially prevented amyloid internalization into ARPE-19 cells and maintained their viability in the presence of toxic oligomeric and fibrillar Aß42 entities in vitro. FRET competition assay was performed and confirmed the binding of PEDF-335 to 67LR in RPE-like cells. Wild-type rats were treated with intravitreal PEDF-335 in the experimental eye 2 days prior to administration of retinotoxic Aß42 oligomers or fibrils to both eyes. Retinal function was assessed by electroretinography through 6 weeks post injection. The ERG responses in rats treated with oligomeric or fibrillar Aß42 assemblies were near-normal in eyes previously treated with intravitreal PEDF-335, whereas those measured in the control eyes treated with injection of the Aß42 assemblies alone showed pathologic attenuation of the retinal function through 6 weeks. The retinal presence of 67LR was determined ex vivo by immunostaining and western blotting. Retinal staining demonstrated the constitutional expression of 67LR mainly in the retinal nuclear layers. In the presence of Aß42, the levels of 67LR were increased, although its retinal distribution remained largely unaltered. In contrast, no apparent differences in the retinal expression level of 67LR were noted following exposure to PEDF-335 alone, and its pattern of localization in the retina remained similarly concentrated primarily in the inner and outer nuclear layers. In summary, we found that PEDF-335 confers protection against Aß42-mediated retinal toxicity, with significant effects noted in cells as well as in vivo in rats. The effects of PEDF-335 in the retina are potentially mediated via binding to 67LR and by at least partial inhibition of Aß42 internalization. These results suggest that PEDF-335 may merit further consideration in the development of targeted inhibition of amyloid-related toxicity in the retina. More broadly, our observations provide evidence on the importance of extracellular versus intracellular Aß42 in the retina and suggest concepts on the molecular mechanism of Aß retinal pathogenicity.

The Surprising Nonlinear Effects of S100A9 Proteins in the Retina.

Age-related macular degeneration (AMD) is a complex disease in which inflammation is implicated as a key factor but the precise molecular mechanisms are poorly understood. AMD lesions contain an excess of the pro-inflammatory S100A9 protein, but its retinal significance was yet unexplored. S100A9 was shown to be intrinsically amyloidogenic in vitro and in vivo. Here, we hypothesized that the retinal effects of S100A9 are related to its supramolecular conformation. ARPE-19 cultures were treated with native dimeric and fibrillar S100A9 preparations, and cell viability was determined. Wild-type rats were treated intravitreally with the S100A9 solutions in the right eye and with the vehicle in the left. Retinal function was assessed longitudinally by electroretinography (ERG), comparing the amplitudes and configurations for each intervention. Native S100A9 had no impact on cellular viability in vitro or on the retinal function in vivo. Despite dispersed intracellular uptake, fibrillar S100A9 did not decrease ARPE-19 cell viability. In contrast, S100A9 fibrils impaired retinal function in vivo following intravitreal injection in rats. Intriguingly, low-dose fibrillar S100A9 induced contrasting in vivo effects, significantly increasing the ERG responses, particularly over 14 days postinjection. The retinal effects of S100A9 were further characterized by glial and microglial cell activation. We provide the first indication for the retinal effects of S100A9, showing that its fibrils inflicted retinal dysfunction and glial activation in vivo, while low dose of the same assemblies resulted in an unpredicted enhancement of the ERG amplitudes. These nonlinear responses highlight the consequences of self-assembly of S100A9 and provide insight into its pathophysiological and possibly physiological roles in the retina.

Radiological findings in poisoning by synthetic cannabinoids adulterated with brodifacoum.

OBJECTIVES: Severe coagulopathy due to consumption of synthetic cannabinoids adulterated with brodifacoum, a long-acting anticoagulant, is an emerging worldwide hazard. Here, we review the spectrum of imaging findings in adulterated cannabinoid poisoning. MATERIALS AND METHODS: In this retrospective study, we used the Israeli Poison Information Center database to identify patients with cannabinoid-associated coagulopathy who presented to the Rambam Health Care Campus, where most patients were treated during an outbreak in northern Israel between September 2021 and June 2022. All relevant imaging studies for these patients were reviewed. We estimated the sensitivity of findings for cannabinoid-associated coagulopathy. Associations between a continuous variable and a dichotomous outcome were assessed with the Mann-Whitney U test. RESULTS: We identified 48 patients (mean age 40 years ± 9 [SD], 43 males) with 54 hospitalizations due to cannabinoid-associated coagulopathy. Symptomatic hemorrhage was documented in 50 (93%) cases at presentation, most of whom (78%) had hemorrhage from multiple systems. The most common bleeding site was the genitourinary collecting system, with a characteristic sign of suburothelial bleeding in 16/18 of performed abdominal CTs (sensitivity 89% [CI 65-99%] for cannabinoid-associated coagulopathy). Intramural bowel hematomas were noted in 70% (7/10) of CTs of patients with gastrointestinal bleeding. Incidental bleeding sites were identified on imaging in 24% of patients. An increased number of bleeding sites was associated with need for vasopressors (difference in bleeding sites 3.00 [95% CI 0.99-4.00], p = 0.026). CONCLUSION: CT plays a key role in the diagnosis and work-up of adulterated cannabinoid-associated coagulopathy. Characteristic signs include suburothelial hemorrhage and intramural bowel hematomas. CLINICAL RELEVANCE STATEMENT: Recognition of radiological signs of adulterated synthetic cannabinoid-associated coagulopathy is critical for optimizing outbreak control on the public health level and ensuring timely treatment on the individual patient level. KEY POINTS: • Severe coagulopathy due to consumption of synthetic cannabinoids adulterated with brodifacoum, a long-acting anticoagulant, is an emerging worldwide threat. • Characteristic imaging signs include suburothelial bleeding, intramural bowel hematomas, and rare incidental bleeding sites. • Imaging has a pivotal role in optimizing outbreak control and ensuring timely and appropriate treatment.

Is there room for prompt routine ophthalmic examination in neonates with congenital cytomegalovirus (CMV) infection during the neonatal period?

PURPOSE: To establish the clinical necessity of routine targeted ophthalmic examination of newborns with congenital cytomegalovirus (CMV) infection during the neonatal period. METHODS: This retrospective study included consecutive neonates that were referred for ophthalmological screening within the context of a proven congenital CMV infection. The presence of CMV-related ocular and systemic findings was determined. RESULTS: Among the 91 patients included in this study, 72 (79.12%) were symptomatic with one or more of the following manifestations: abnormal brain ultrasound (42; 46.15%), small for gestational age (29; 31.87%), microcephaly (23; 25.27%), thrombocytopenia (14; 15.38%), sensory neural hearing loss (13; 14.29%), neutropenia (12; 13.19%), anemia (4; 4.4%), skin lesions (4; 4.4%), hepatomegaly (3; 3.3%), splenomegaly (3; 3.3%), direct hyperbilirubinemia (2; 2.2%). Not one single neonate in this cohort had any of the ocular findings surveyed. CONCLUSION: The presence of ophthalmological findings among neonates with congenital CMV infection during the neonatal period is infrequent, suggesting that routine ophthalmological screening may be safely deferred for the post-neonatal period.

Reduced Electroretinogram Responses in Morphologically Normal Retina in Patients with Primary Hyperoxaluria Type 1.

Purpose: To describe ocular findings in individuals with primary hyperoxaluria type 1 (PH1), focusing on the correlations between retinal anatomy and retinal function. To characterize the retinal alterations that occur at different disease stages by evaluating individuals with diverse degrees of renal impairment associated with PH1. Design: A cross-sectional study. Participants: Patients diagnosed with PH1 based on clinical criteria and genetic testing, treated in the Pediatric Nephrology Unit of the Ruth Children's Hospital, Rambam Health Care Campus, Haifa, Israel between 2013 and 2021. Methods: The ophthalmological assessment included a slit-lamp biomicroscopy of the anterior and posterior segment or indirect ophthalmoscopy. Electroretinography was employed for assessment of the retinal function, and retinal imaging included spectral-domain OCT and fundus autofluorescence. A systematic evaluation of the disease stage was based on clinical criteria including physical examination, purposeful imaging (X-ray, echocardiography, and US abdomen), and laboratory tests as needed. Main Outcome Measures: Anatomical and functional assessment of the retina in patients with PH1, and the relationship between retinal dysfunction and kidney impairment. Results: A total of 16 eyes were examined in the study of 8 children ranging in age from 4 to 19 years. Four eyes (25%) showed normal structural and functional retinal findings, 8 eyes (50%) presented functional impairment in the absence of pathological structural findings, and 4 eyes (25%) had advanced retinal damage that manifested as significant morphological and functional impairment. There was no direct relationship between the severity of the renal disease and the severity of the retinal phenotype. Conclusions: Subjects with PH1 present varying severity levels of the retinal phenotype, with possible discrepancy between the clinical retinal morphology and the retinal function noted on electroretinography. These findings raise questions about the molecular basis of the retinal manifestations in PH1. The presence of functional impairment in the absence of evident crystal deposition in the retina suggests that, in addition to oxalate crystal accumulation, other biomolecular processes may play a role in the development of retinopathy.

Unusual and Severe Complications of Acute Schistosomiasis in Travelers.

Acute schistosomiasis (ASC) is a hypersensitivity reaction seen mostly in nonimmune travelers and manifests mainly with fever, urticaria, and respiratory symptoms. We describe unusual severe presentations of ASC in 3 patients, including hip-monoarthritis, peri-myocarditis, and optic neuritis. In all 3 patients, clinical symptoms appeared or worsened after praziquantel administration.

Ophthalmologic emergency room visits during COVID-19 lockdown-Characterization from Haifa, Israel.

PURPOSE: To characterize quantitative differences among ophthalmologic emergency room (OER) encounters at Rambam Health Care Campus during a 6-week complete lockdown at the peak of the first COVID-19 wave as compared to a corresponding uneventful period a year earlier. METHODS: A retrospective chart analysis of all OER encounters during the lockdown and non-lockdown period was conducted. Patients were stratified into primary ophthalmological conditions (OER visits) and cases in which ophthalmologic consultations were requested by a non-ophthalmologist (OER consultations). The following parameters were compared: total number of cases, age, gender, chief complaint/diagnosis categorized into major entities, and discharge vs. hospitalization. For continuous variables a t-test was used and for categorical variables a chi-squared or Fisher's exact test was used. A 2-sided p value <0.05 was considered statistically significant. RESULTS: The total number of patients in the lockdown and non-lockdown groups was 486 and 992, respectively, showing a 51% decrease in visits during lockdown. In the non-lockdown and lockdown groups 56% and 61% of patients were male (p = 0.07), with an average age of 42 (range 0-97, SD 23) and 43 (range 0-90, SD 22) years, respectively (p = 0.44). No statistically significant proportional increase was found for any diagnostic category between the OER visits (p = 0.07) and OER consultation groups (p = 0.77). Nevertheless, analysis revealed a non-significant increase in the proportion of eye trauma from 14.8% to 21.2%, and reduction in eyelid conditions from 10.7% to 5.8%. The total number of OER visits demanding urgent intervention on admission was 43 (non-lockdown) and 24 (lockdown), while hospitalization ratio (hospitalizations/visits) was 8.8% and 10.6%, respectively (p = 0.44). CONCLUSIONS: During the COVID-19 lockdown the guideline for patients in Israel was to avoid unnecessary hospital visits. Since patients tended to avoid the OER rather uniformly regardless of their specific eye condition, determining the risk-benefit of such recommendations and identifying high-risk sub-populations are critical public health issues.

[CUFFING PRISONERS AND DETAINEES IN ISRAELI HOSPITALS - A MULTI-CENTER STUDY].

AIMS: To describe the extent of prisoner/detainee cuffing and characterize cuffing methods. BACKGROUND: Thousands of prisoners and detainees receive medical treatment in Israeli hospitals every year. According to the Israeli law, cuffing during hospital stay should be an exceptional measure, to be considered only in cases of real threat of violence or escape, based on individual assessment. There is no documentation of cuffing rates in hospitals. METHODS: A multi-center study in 12 hospitals was performed during 2020-2021. Data were collected prospectively or retrieved retrospectively from security records, when available. RESULTS: A total of 1857 prisoners/detainees were documented, of whom 1794 (96.6%) were cuffed. Of the 241 hospitalized patients, 230 (95.4%) were cuffed. Details regarding cuffing methods were available for 185 hospitalized patients, revealing that at least 63 patients (68% of patients for whom details regarding cuffing to bed were available) were cuffed to the bed with opposite arm and leg in a cross position. Cuffing rates of prisoners under custody of the Prisons Authority, police and the Israeli Defense Forces, were 98.5%, 96.6%, and 83%, respectively. Impaired mobility for medical reasons was documented in 64 cases, of whom 85.9% were cuffed regardless. CONCLUSIONS: Cuffing of prisoners/detainees in Israeli hospitals is performed non-selectively, in violation of the law. During hospitalization, cuffing is usually performed in a cross position, severely impairing mobility. Our findings highlight the need for routine documentation of cuffing due to its medical consequences and the responsibility of medical staff towards patients according to rules of ethics and regulations.

Severely Elevated Intraocular Pressure Following Traumatic Asphyxia: A Case Report.

BACKGROUND: Traumatic asphyxia is a syndrome caused by a sudden pressure rise in the chest caused by crushing injury of the thorax or upper abdomen. It is associated with a variety of thoracic injuries, neurological symptoms, and ocular complications. CASE REPORT: We report an unusual case of traumatic asphyxia complicated by severe, sight-threatening, elevation in intraocular pressure. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: After initial stabilization, the treatment of patients with traumatic asphyxia is supportive and is mainly directed toward the accompanying injuries and complications. A complete and prompt ophthalmologic examination, including tonometry, should be an integral part of the secondary survey. This is particularly important in patients who cannot report visual impairment, such as children or unconscious patients.

Neuroretinitis with secondary retinal venous stasis in a patient with Schistosomiasis.

PURPOSE: Schistosomiasis, one of the most important parasitic diseases in humans, is caused by the trematode parasites. Common manifestations include gastrointestinal and genitourinary symptoms while ophthalmologic involvement is rare. Here we report a case of retinal vein occlusion and neuroretinitis secondary to a schistosomiasisis infection. OBSERVATIONS: A healthy 23-year-old man presented with headache and decreased vision in his right eye. Ophthalmic examination revealed a swollen disc, engorged retinal veins with retinal hemorrhages in all quadrants and macular edema with hard exudates ('macular star'). Fluorescein Angiography demonstrated a hot disk and an irregular pattern of filling defects along a major retinal vein. Further questioning revealed that a few months earlier, the patient had returned from an endemic area and was found seropositive for schistosomiasis. CONCLUSION: In this case of neuroretinitis and secondary retinal venous stasis, the presumed underlying mechanism is associated with embolization of Schistosoma eggs or deposition of immune complexes. Although ophthalmic manifestations of schistosomiasis are rare, awareness should be maintained especially among world-travelers with unusual ocular findings.

The retinal toxicity profile towards assemblies of Amyloid-ß indicate the predominant pathophysiological activity of oligomeric species.

Amyloid-ß (Aß), reported as a significant constituent of drusen, was implicated in the pathophysiology of age-related macular degeneration (AMD), yet the identity of the major pathogenic Aß species in the retina has remained hitherto unclear. Here, we examined the in-vivo retinal impact of distinct supramolecular assemblies of Aß. Fibrillar (Aß40, Aß42) and oligomeric (Aß42) preparations showed clear biophysical hallmarks of amyloid assemblies. Measures of retinal structure and function were studied longitudinally following intravitreal administration of the various Aß assemblies in rats. Electroretinography (ERG) delineated differential retinal neurotoxicity of Aß species. Oligomeric Aß42 inflicted the major toxic effect, exerting diminished ERG responses through 30 days post injection. A lesser degree of retinal dysfunction was noted following treatment with fibrillar Aß42, whereas no retinal compromise was recorded in response to Aß40 fibrils. The toxic effect of Aß42 architectures was further reflected by retinal glial response. Fluorescence labelling of Aß42 species was used to detect their accumulation into the retinal tissue. These results provide conceptual evidence of the differential toxicity of particular Aß species in-vivo, and promote the mechanistic understanding of their retinal pathogenicity. Stratifying the impact of pathological Aß aggregation in the retina may merit further investigation to decipher the pathophysiological relevance of processes of molecular self-assembly in retinal disorders.

Induction of retinopathy by fibrillar oxalate assemblies.

The formation of metabolite fibrillar assemblies represents a paradigm shift in the study of human metabolic disorders. Yet, direct clinical relevance has been attributed only to metabolite crystals. A notable example for metabolite crystallization is calcium oxalate crystals observed in various diseases, including primary hyperoxaluria. We unexpectedly observed retinal damage among young hyperoxaluria patients in the absence of crystals. Exploring the possible formation of alternative supramolecular organizations and their biological role, here we show that oxalate can form ordered fibrils with no associated calcium. These fibrils inflict intense retinal cytotoxicity in cultured cells. A rat model injected with oxalate fibrils recaptures patterns of retinal dysfunction observed in patients. Antibodies purified from hyperoxaluria patient sera recognize oxalate fibrils regardless of the presence of calcium. These findings highlight a new molecular basis for oxalate-associated disease, and to our knowledge provide the first direct clinical indication for the pathogenic role of metabolite fibrillar assemblies.