Publications

2020

Jacob A, Brun L, Gil PJ, Ménard L, Bouzelha M, Broucque F, Roblin A, Vandenberghe L, Adjali O, Robin C, François A, Blouin V, Penaud-Budloo M, Ayuso E. Homologous Recombination Offers Advantages Over Transposition-Based Systems to Generate Recombinant Baculovirus for Adeno-Associated Viral Vector Production. Biotechnol J. 2020;:e2000014.
Viral vectors have a great potential for gene delivery, but manufacturing at a pharmaceutical scale is a big challenge for the industry. The baculovirus-insect cell system is one of the most scalable platforms to produce clinical-grade recombinant Adeno-Associated Virus (rAAV) vectors. The standard procedure to generate recombinant baculovirus is based on Tn7 transposition which is time-consuming and still suffers technical constraints. Moreover, werecently showed that baculoviral sequences adjacent to the AAV ITRs are preferentially encapsidated into the rAAV vector particles. This observation raised concerns about safety for clinical applications due to the presence of bacterial and antibiotic resistance coding sequences with a Tn7-mediated system for the construction of baculoviruses reagents. Here, weinvestigated a faster and safer method based on homologous recombination (HR). First, weconfirmed the functionality of the inserted cassette and the absence of undesirable genes into HR-derived baculoviral genomes. Strikingly, wefound that the exogenous cassette showed increased stability over passages when using the HR system. Finally, wetested these materials to produce rAAV vectors. The baculoviruses originated from both systems lead to high rAAV vector genome yields, with the advantage of the HR system being exempted from undesirable bacterial genes which provides an additional level of safety for the manufacturing of rAAV vectors. Overall, this study highlights the importance of the upstream process and starting biologic materials to generate safer rAAV biotherapeutic products. This article is protected by copyright. All rights reserved.
Steinberg E, Fluksman A, Zemmour C, Tischenko K, Karsch-Bluman A, Brill-Karniely Y, Birsner A, D’Amato R, Benny O. Low dose amiodarone reduces tumor growth and angiogenesis. Sci Rep. 2020;10(1):18034.
Amiodarone is an anti-arrhythmic drug that was approved by the US Food and Drug Administration (FDA) in 1985. Pre-clinical studies suggest that Amiodarone induces cytotoxicity in several types of cancer cells, thus making it a potential candidate for use as an anti-cancer treatment. However, it is also known to cause a variety of severe side effects. We hypothesized that in addition to the cytotoxic effects observed in cancer cells Amiodarone also has an indirect effect on angiogensis, a key factor in the tumor microenvironment. In this study, we examined Amiodarone's effects on a murine tumor model comprised of U-87 MG glioblastoma multiforme (GBM) cells, known to form highly vascularized tumors. We performed several in vitro assays using tumor and endothelial cells, along with in vivo assays utilizing three murine models. Low dose Amiodarone markedly reduced the size of GBM xenograft tumors and displayed a strong anti-angiogenic effect, suggesting dual cancer fighting properties. Our findings lay the ground for further research of Amiodarone as a possible clinical agent that, used in safe doses, maintains its dual properties while averting the drug's harmful side effects.
Valdes L, Bispo P, Sobrin L. Application of Metagenomic Sequencing in the Diagnosis of Infectious Uveitis. Semin Ophthalmol. 2020;:1–4.
: to summarize the origin and very recent history of the use of metagenomic sequencing for the diagnosis of infectious uveitis, convey the technique as described by one of the primary institutions experimenting with the technology, and present recent successful applications of the technology as well as potential advantages and pitfalls compared to other current diagnostic tools.: review of peer-reviewed literature concerning metagenomic sequencing for the diagnosis of infectious uveitis.: compared to existing diagnostic methods, metagenomic deep sequencing is a sensitive, unbiased, and comprehensive technique with great potential for diagnosing the causative pathogens of cases of infectious uveitis. However, many issues remain to be addressed in the process of developing this technology, including but not limited to the potentially overwhelming amount of information generated, definition of diagnostic thresholds, demonstration of validity, contamination, and cost.
Roh M, Miller J, Jeng-Miller K, Wang J, Laíns I, Silverman R, Loewenstein J, Husain D, Vavvas D, Miller J. Subthreshold Exudative Choroidal Neovascularization Associated With Age-Related Macular Degeneration Identified by Optical Coherence Tomography Angiography. J Vitreoretin Dis. 2020;4(5):377–385.
Purpose: This article describes the clinical and multimodal imaging characteristics of subthreshold exudative choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD). Methods: Among 3773 patients with AMD, 8 eyes (6 patients) were identified with the clinical phenotype of interest. Dilated fundus examinations, color fundus photography, fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT), and OCT angiography (OCTA) were performed. Results: OCT typically showed a moderately reflective irregular pigment epithelial detachment with overlying subretinal fluid (SRF). Traditional FA did not show leakage and ICGA showed no definitive neovascular network or hot spots. However, OCTA clearly demonstrated a CNV within the pigment epithelial detachment. The majority of our cases (7 of 8) did not receive antivascular endothelial growth factor (anti-VEGF) injections, and visual acuity remained stable over the available follow-up period of I to 10 years. Conclusions: CNV is often associated with SRF and vision loss in AMD, usually requiring frequent anti-VEGF injections. OCTA allowed us to better identify CNV not readily detected on FA and ICGA. Although some have suggested early clinical intervention with anti-VEGF injections in any case with fluid and confirmed CNV on OCTA, we describe a subset of AMD patients with SRF who may be better managed by observation. These cases may represent a more indolent, mature, and stable vascular network.
Duarte, Bauer, Pinto, Saleh Velez, Estudillo-Guerra, Pacheco-Barrios, Gunduz, Crandell, Merabet L, Fregni. Cortical plasticity in phantom limb pain: A fMRI study on the neural correlates of behavioral clinical manifestations. Psychiatry Res Neuroimaging. 2020;304:111151.
The neural mechanism of phantom limb pain (PLP) is related to the intense brain reorganization process implicating plasticity after deafferentation mostly in sensorimotor system. There is a limited understanding of the association between the sensorimotor system and PLP. We used a novel task-based functional magnetic resonance imaging (fMRI) approach to (1) assess neural activation within a-priori selected regions-of-interested (motor cortex [M1], somatosensory cortex [S1], and visual cortex [V1]), (2) quantify the cortical representation shift in the affected M1, and (3) correlate these changes with baseline clinical characteristics. In a sample of 18 participants, we found a significantly increased activity in M1 and S1 as well as a shift in motor cortex representation that was not related to PLP intensity. In an exploratory analyses (not corrected for multiple comparisons), they were directly correlated with time since amputation; and there was an association between increased activity in M1 with a lack of itching sensation and V1 activation was negatively correlated with PLP. Longer periods of amputation lead to compensatory changes in sensory-motor areas; and itching seems to be a protective marker for less signal changes. We confirmed that PLP intensity is not associated with signal changes in M1 and S1 but in V1.
Subburaman GB, Kempen J, Durairaj S, Balakrishnan V, Valaguru V, Namperumalsamy VP, Thulasiraj RD, Gupta S. Making the decision to donate eyes: Perspectives from the families of the deceased in Madurai, India. Indian J Ophthalmol. 2020;68(10):2094–2098.
Purpose: To identify factors affecting family members' decision whether to donate eye organs. Methods: A community-based case-control study based on in-home interviews with families of deceased individuals who had or had not donated eye organs, in Madurai district, Tamil Nadu, India. Data collected were knowledge and awareness of eye donations, whether the deceased individual had expressed or pledged willingness to donate, and family members' attitudes and willingness to donate their own eye organs. Results: Seventy-six families of donors and 256 families of non-donors completed the survey. Multivariable analysis showed that the following variables were significantly associated with a donation: age, whether the deceased had registered for eye donation, pre-expressed willingness of deceased to donate, whether family members personally know beneficiaries of eye donations, and higher score on a scale evaluating knowledge and awareness about eye donation. The majority of donors' families (71%) had been encouraged by someone to donate. Among non-donor families, a substantially larger fraction (52.8%) indicated they would have donated had someone reminded or encouraged them to do so, in comparison with those who indicated lack of awareness or knowledge (14.5%). Conclusion: Community programs are likely to be effective if they encourage individuals to pledge their eyes or express their willingness to donate their eyes to family members in advance of death; they increase public awareness of the value of eye donation. A friend, family member, neighbor or counselor approaching bereaved families and having a dialogue about eye donation would substantially increase the probability of a decision to donate.
Jafari, Lehmann, Wolkow, Juliano, Bleier, Reinshagen. Radioanatomic Characteristics of the Posteromedial Intraconal Space: Implications for Endoscopic Resection of Orbital Lesions. AJNR Am J Neuroradiol. 2020;41(12):2327–2332.
BACKGROUND AND PURPOSE: Imaging is essential in the diagnostic work-up of patients with orbital lesions. The position of an orbital lesion relative to the inferomedial muscular trunk of the ophthalmic artery determines endoscopic resectability, anticipated technical difficulty, and patient morbidity. Although the inferomedial muscular trunk is not readily identifiable on preoperative imaging, we hypothesize that it is spatially approximate to the location where the ophthalmic artery crosses the optic nerve. Our aim was to determine whether the ophthalmic artery-optic nerve crosspoint anatomically approximates the inferomedial muscular trunk in a cadaver study and can be appreciated on imaging of known posteromedial orbital lesions. MATERIALS AND METHODS: Dissection was performed on 17 fresh-frozen cadaver orbits to assess the relationship between the inferomedial muscular trunk and ophthalmic artery-optic nerve crosspoint. Retrospective review of imaging in 9 patients with posteromedial orbital lesions assessed posteromedial orbital compartment characteristics and the ability to locate the ophthalmic artery-optic nerve crosspoint. RESULTS: In our cadaver study, the mean distance between the ophthalmic artery-optic nerve crosspoint and the inferomedial muscular trunk was 1.21 ± 0.64 mm. Retrospectively, the ophthalmic artery-optic nerve crosspoint was identifiable in 9/9 patients, whereas the inferomedial muscular trunk was not identifiable in any patient. Total or partial effacement of the posteromedial intraconal fat triangle was observed in 9/9 patients. CONCLUSIONS: This study of neurovascular relationships within the posteromedial orbit demonstrates that the ophthalmic artery-optic nerve crosspoint closely approximates the inferomedial muscular trunk and can be seen in patients with posteromedial orbital lesions. Posteromedial intraconal fat effacement may help to localize these lesions. These findings may facilitate multidisciplinary communication and help predict lesion resectability and patient outcomes.
Narayanan D, Rodriguez J, Wallstrom G, Welch D, Chapin M, Arrigg P, Abelson M. An exploratory study to evaluate visual function endpoints in non-advanced age-related macular degeneration. BMC Ophthalmol. 2020;20(1):424.
BACKGROUND: To prevent irreversible vision loss in age-related macular degeneration (AMD), it is critical to detect retinal dysfunction before permanent structural loss occurs. In the current study we evaluated a series of visual function tests to identify potential endpoints to detect visual dysfunction in non-advanced AMD. METHODS: A series of visual function tests were performed on 23 non-advanced AMD subjects (AREDS grade 1-4 on simplified scale) and 34 age-matched normals (AREDS grade 0). Tests included some commonly used endpoints such as ETDRS visual acuity (VA), low luminance (LL) 2.0ND ETDRS VA, MNREAD as well as newly developed tests such as the Ora-VCF™ test, Ora-tablet reading test, color sensitivity etc. Differences between the two groups were compared for each test. Test-retest repeatability and reproducibility was assessed on a subset of subjects and percent agreement was calculated. RESULTS: There was no difference in standard ETDRS VA between non-advanced AMD (0.06 ± 0.02 logMAR) and normal groups (0.04 ± 0.02 logMAR) (p = 0.57). LL 2.0 ETDRS VA and MNREAD showed no difference between the groups (p > 0.05). Ora-VCF™ test was significantly worse in the non-advanced AMD group compared to normals (0.67 ± 0.07 in AMD; 0.45 ± 0.04 in normals, p = 0.005). Non-advanced AMD subjects also had significantly worse reading performance using the Ora-tablet with LL 2.0ND (114.55 ± 11.22 wpm in AMD; 145.17 ± 9.55 wpm in normals p = 0.049). No significant difference between the groups was noted using other tests. Repeatability was 82% for Ora-VCF™ test and 92% for Ora-tablet LL 2.0ND reading. Reproducibility was 89% for both Ora-VCF™ test and Ora-tablet LL 2.0ND reading. CONCLUSION: While there was no significant difference between non-advanced AMD and normal groups using some current common endpoints such as ETDRS VA, LL 2.0 ETDRS VA or MNREAD, Ora-VCF™ test and Ora-tablet LL 2.0ND reading tests were able to identify significant visual dysfunction in non-advanced AMD subjects. These tests show promise as endpoints for AMD studies.
Venkatraman P, Mills-Henry I, Padmanabhan KR, Pascuzzi P, Hassan M, Zhang J, Zhang X, Ma P, Pang CP, Dowling J, Zhang M, Leung YF. Rods Contribute to Visual Behavior in Larval Zebrafish. Invest Ophthalmol Vis Sci. 2020;61(12):11.
Purpose: Although zebrafish rods begin to develop as early as 2 days postfertilization (dpf), they are not deemed anatomically mature and functional until 15 to 21 dpf. A recent study detected a small electroretinogram (ERG) from rods in a cone mutant called no optokinetic response f (nof) at 5 dpf, suggesting that young rods are functional. Whether they can mediate behavioral responses in larvae is unknown. Methods: We first confirmed rod function by measuring nof ERGs under photopic and scotopic illumination at 6 dpf. We evaluated the role of rods in visual behaviors using two different assays: the visual-motor response (VMR) and optokinetic response (OKR). We measured responses from wild-type (WT) larvae and nof mutants under photopic and scotopic illuminations at 6 dpf. Results: Nof mutants lacked a photopic ERG. However, after prolonged dark adaptation, they displayed scotopic ERGs. Compared with WT larvae, the nof mutants displayed reduced VMRs. The VMR difference during light onset gradually diminished with decreased illumination and became nearly identical at lower light intensities. Additionally, light-adapted nof mutants did not display an OKR, whereas dark-adapted nof mutants displayed scotopic OKRs. Conclusions: Because the nof mutants lacked a photopic ERG but displayed scotopic ERGs after dark adaptation, the mutants clearly had functional rods. WT larvae and the nof mutants displayed comparable scotopic light-On VMRs and scotopic OKRs after dark adaptation, suggesting that these responses were driven primarily by rods. Together, these observations indicate that rods contribute to zebrafish visual behaviors as early as 6 dpf.