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Episodic Upper Eyelid Edema in an African American Patient. JAMA Ophthalmol 2024:2819149. [PMID: 38780928 DOI: 10.1001/jamaophthalmol.2024.1517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
An African American patient in their 60s with a history of monoclonal gammopathy of unknown significance presents to the oculoplastic service for intermittent, bilateral upper eyelid swelling and pain for 2 years. Examination reveals hyperpigmented, spongy eyelid edema with redundant skin, and no lymphadenopathy is present. What would you do next?
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Using optical coherence tomography to optimize Mohs micrographic surgery. Sci Rep 2024; 14:8900. [PMID: 38632358 PMCID: PMC11024158 DOI: 10.1038/s41598-024-53457-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 01/31/2024] [Indexed: 04/19/2024] Open
Abstract
Mohs micrographic surgery (MMS) is considered the gold standard for treating high-risk cutaneous basal cell carcinoma (BCC), but is expensive, time-consuming, and can be unpredictable as to how many stages will be required or how large the final lesion and corresponding surgical defect will be. This study is meant to investigate whether optical coherence tomography (OCT), a highly researched modality in dermatology, can be used preoperatively to map out the borders of BCC, resulting in fewer stages of MMS or a smaller final defect. In this prospective study, 22 patients with BCC undergoing surgical excision were enrolled at a single institution. All patients had previously received a diagnostic biopsy providing confirmation of BCC and had been referred to our center for excision with MMS. Immediately prior to performing MMS, OCT was used to map the borders of the lesion. MMS then proceeded according to standard protocol. OCT images were compared to histopathology for agreement. Histopathologic analysis of 7 of 22 MMS specimens (32%) revealed a total absence of BCC, indicating resolution of BCC after previous diagnostic biopsy. This outcome was correctly predicted by OCT imaging in 6 of 7 cases (86%). Nine tumors (9/22, 41%) had true BCC and required a single MMS stage, which was successfully predicted by pre-operative OCT analysis in 7 of 9 cases (78%). The final six tumors (27%) had true BCC and required two MMS stages for complete excision; preoperative OCT successfully predicted the need for a second stage in five cases (5/6, 83.3%). Overall, OCT diagnosed BCC with 95.5% accuracy (Cohen's kappa, κ = 0.89 (p-value = < 0.01) in the center of the lesion. Following a diagnostic biopsy, OCT can be used to verify the existence or absence of residual basal cell carcinoma. When residual tumor is present that requires excision with MMS, OCT can be used to predict tumor borders, optimize surgery and minimize the need for additional surgical stages.
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Transcutaneous retrobulbar amphotericin B for rhino-orbital-cerebral mucormycosis: a multi-center retrospective comparative study. Orbit 2024; 43:41-48. [PMID: 36880205 DOI: 10.1080/01676830.2023.2186435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/25/2023] [Indexed: 03/08/2023]
Abstract
PURPOSE To assess whether transcutaneous retrobulbar amphotericin B injections (TRAMB) reduce exenteration rate without increasing mortality in rhino-orbital-cerebral mucormycosis (ROCM). METHODS In this retrospective case-control study, 46 patients (51 eyes) with biopsy-proven ROCM were evaluated at 9 tertiary care institutions from 1998 to 2021. Patients were stratified by radiographic evidence of local orbital versus extensive involvement at presentation. Extensive involvement was defined by MRI or CT evidence of abnormal or loss of contrast enhancement of the orbital apex with or without cavernous sinus, bilateral orbital, or intracranial extension. Cases (+TRAMB) received TRAMB as adjunctive therapy while controls (-TRAMB) did not. Patient survival, globe survival, and vision/motility loss were compared between +TRAMB and -TRAMB groups. A generalized linear mixed effects model including demographic and clinical covariates was used to evaluate the impact of TRAMB on orbital exenteration and disease-specific mortality. RESULTS Among eyes with local orbital involvement, exenteration was significantly lower in the +TRAMB group (1/8) versus -TRAMB (8/14) (p = 0.04). No significant difference in mortality was observed between the ±TRAMB groups. Among eyes with extensive involvement, there was no significant difference in exenteration or mortality rates between the ±TRAMB groups. Across all eyes, the number of TRAMB injections correlated with a statistically significant decreased rate of exenteration (p = 0.048); there was no correlation with mortality. CONCLUSIONS Patients with ROCM with local orbital involvement treated with adjunctive TRAMB demonstrated a lower exenteration rate and no increased risk of mortality. For extensive involvement, adjunctive TRAMB does not improve or worsen these outcomes.
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Cocaine Orbitopathy Complicated by Orbital Wall Defects, Bilateral Naso-Orbital Fistulas, Phthisis, and Bilateral Vision Loss. Ophthalmic Plast Reconstr Surg 2023; 39:e211. [PMID: 36928035 DOI: 10.1097/iop.0000000000002372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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Rapidly Enlarging Primary Cutaneous Anaplastic Large-Cell Lymphoma of the Eyelid. Ophthalmic Plast Reconstr Surg 2023; 39:e170. [PMID: 36852836 DOI: 10.1097/iop.0000000000002343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
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Predictability of the Phenylephrine Test in Congenital Ptosis: Ten Years of Experience. Ophthalmic Plast Reconstr Surg 2023; 39:465-469. [PMID: 36893062 DOI: 10.1097/iop.0000000000002365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
PURPOSE To assess the predictability of phenylephrine testing for congenital ptosis and review outcomes of Müller's Muscle-conjunctival resection (MMCR) for congenital ptosis across ten years of follow-up. METHODS In this retrospective case series, all patients who underwent MMCR for congenital ptosis at a single institution between 2010 and 2020 were identified. Exclusion criteria included patients who had not undergone preoperative testing with 2.5% phenylephrine in the superior fornix; patients who underwent revision surgery; and patients who had a broken suture in the early postoperative period. Demographics, margin-reflex distance 1 (MRD1) values pre- and postphenylephrine, millimeters of tissue resected intraoperatively, and final postoperative MRD1 were recorded. RESULTS A total of 28 patients were included; 19 patients received MMCR and 9 patients received a combined MMCR plus tarsectomy. The amount of tissue resected ranged from 5 to 11 mm. There was no significant difference between median postphenylephrine MRD1 and median final postoperative MRD1 in either surgical group. Neither patient age nor levator function was significantly associated with a change in MRD1 in either group. The addition of a tarsectomy had no bearing on the final MRD1 value. CONCLUSIONS MMCR is a viable option for patients with congenital ptosis and moderate levator function with a response to phenylephrine. In these patients, MRD1 after 2.5% phenylephrine testing correlates to the final postoperative MRD1 outcome within 0.5 mm.
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Kinking of palpebral spring mimicking extrusion. Orbit 2023; 42:224-225. [PMID: 33641592 DOI: 10.1080/01676830.2021.1890136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
PURPOSE Surgical correction of myogenic ptosis is a sophisticated endeavor, as the disease is progressive and the post-operative course is prone to significant complications. We sought to review the literature for repair techniques in different types of myogenic ptosis. METHODS A PubMed/MEDLINE literature search of publications pertaining to surgical outcomes of progressive myogenic ptosis repair was performed. Studies included were original retrospective studies with a minimum of four patients. RESULTS A total of 27 articles were identified and divided by etiology of myogenic ptosis; either chronic progressive external ophthalmoplegia (CPEO), oculopharyngeal muscular dystrophy (OPMD), myasthenia gravis (MG), or mixed. Surgical techniques predominantly involved levator advancement, levator resection, frontalis sling, blepharoplasty, and Fasanella-Servat. Success rates ranged from 60.5% to 100%. Significant postoperative complications included ptosis recurrence, under-correction, over-correction, keratopathy, lagophthalmos, sling exposure, and sling infection. CONCLUSION Like surgical repair for other forms of ptosis, correction of progressive myogenic ptosis is guided by levator excursion. However, myogenic ptosis is especially challenging as it is characterized by worsening ptosis and the loss of protective corneal mechanisms. The goals of care with myogenic ptosis involves repairing ptosis just sufficiently to alleviate visual obstruction while avoiding adverse post-operative complications. This intentional under-correction subsequently increases susceptibility for ptosis recurrence. Myogenic ptosis repair therefore requires delicate balancing between function, sustained repair, and corneal protection.
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Changes in Rat Scleral Collagen Structure Induced by UVA-Riboflavin Crosslinking at Various Tissue Depths in Whole Globe Versus Scleral Patch. Transl Vis Sci Technol 2022; 11:2. [PMID: 35913416 PMCID: PMC9351595 DOI: 10.1167/tvst.11.8.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate structural changes in scleral collagen fibers at various tissue depths before and after photosensitized crosslinking (CXL) both isolated scleral patch versus whole globe using second-harmonic generation (SHG) imaging. Methods Scleral tissues were harvested from Sprague-Dawley rats and separated into three groups: untreated sclera (control), full-thickness scleral patch for CXL (Free Scleral CXL group), and sclera in intact globe for CXL (Globe CXL group). The CXL groups were soaked in 0.1% riboflavin and irradiated with 365 nm ultraviolet-A light (power, 0.45 mW/cm2) for 30 minutes. SHG images were acquired every 5 µm between 10 and 60 µm from the outer scleral surface. Collagen fiber waviness was calculated as the ratio of the total length of a traced fiber and the length of a straight path between the fiber ends. Results In the Free Scleral CXL group, collagen waviness was significantly increased compared to the control group at 35 to 50 µm (P < 0.05). In the Globe CXL group, collagen waviness was decreased compared to control at all depths with statistical significance (P < 0.05) achieved from 10 to 45 µm. Conclusions Depending upon its initial state (i.e., free scleral patch versus mechanically loaded intact globe under pressure), collagen may experience different structural changes after CXL. In addition, the extent of the CXL effects may vary at different depths away from the surface. Translational Relevance Understanding the CXL effects on collagen structure may be important in optimizing the scleral crosslinking protocol for future clinical applications such as preventing myopic progression.
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An Unusual Case of Severe Bilateral Extraocular Muscle Enlargement. JAMA Ophthalmol 2022; 140:738-739. [PMID: 35511150 DOI: 10.1001/jamaophthalmol.2022.0265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Abstract
Purpose Surgery is the standard treatment for floppy eyelid syndrome, but crosslinking (CXL) tarsus has recently been proposed as an alternative. To the best of our knowledge, this study is the first to use second-harmonic generation (SHG) microscopy to examine tarsal collagen ex vivo before and after photo-activated crosslinking. To quantify crosslinking, this study examined fluorescence recovery after photobleaching (FRAP), which indirectly measures tissue stiffness. Methods Upper eyelid tarsal plates were dissected from 21 Sprague-Dawley rats (total of 42 tarsal plates). Six normal plates were sent for histopathology and SHG imaging; the remaining 36 were crosslinked with phosphate-buffered saline (PBS) alone or riboflavin in PBS (concentrations of 0.1%, 0.3%, and 0.5%). Tissues were irradiated with 365-nm ultraviolet A light (power, 0.45 mW/cm2) for 30 minutes and immediately underwent SHG microscopy. Stiffness was indirectly measured with FRAP using fluorescein isothiocyanate (FITC)-dextran. Results SHG imaging of normal tarsus showed that the organization of collagen bundles is complex and varies greatly depending on location. After crosslinking with high-concentration riboflavin (0.5%), collagen fibers showed clear structural changes, becoming more densely packed and wavier compared to control. FRAP half-time to fluorescence recovery was significantly increased (P < 0.05), indirectly indicating increased tissue stiffness. No structural changes were observed after crosslinking with lower riboflavin concentrations of 0.1% and 0.3%. Conclusions This is the first report of SHG microscopy used to image tarsus collagen before and after crosslinking. These results highlight collagen structural changes, with effects on tissue stiffness indirectly confirmed by FRAP. Translational Relevance Collagen fibers in the tarsus may be a therapeutic target for crosslinking in order to treat symptomatic floppy eyelid syndrome.
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Bilateral Ptosis and Ophthalmoplegia in a Young Man. JAMA Ophthalmol 2021; 139:234-235. [PMID: 33270091 DOI: 10.1001/jamaophthalmol.2020.4071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Ophthalmic Eosinophilic Granulomatosis With Polyangiitis (Churg-Strauss Syndrome): A Systematic Review of the Literature. Ophthalmic Plast Reconstr Surg 2019; 35:7-16. [PMID: 30134390 DOI: 10.1097/iop.0000000000001202] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE To review and summarize the clinical features, presentations, diagnostic modalities, and management of ophthalmic manifestations of eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss Syndrome). METHODS A systematic PubMed search of all English articles on EGPA with ophthalmic involvement was performed. Emphasis was placed on English-language articles, but any article with an abstract translated into English was also included. Only those cases that satisfied the American Rheumatology criteria (1990) for diagnosis were included. Data examined included epidemiology, pathogenesis, presentations, diagnostic modalities, and management. RESULTS There was a wide range in ophthalmic manifestations of EGPA. In order of most frequent presentation to least frequent, these include central retinal artery or vein occlusion, ischemic optic neuropathy, conjunctival nodules, orbital myositis, proptosis, dacryoadenitis, retinal vasculitis/infarcts/edema, cranial nerve palsy, and amaurosis. The 46 qualifying cases were divided into the categories of ischemic vasculitis versus idiopathic orbital inflammation due to prognostic significance. Ischemic vasculitis cases tended to be older patients (p = 0.03), unilateral (p = 0.006), require immunosuppressive therapy beyond steroids (p = 0.015), and were less likely to show improvement on therapy (p = 0.0003). CONCLUSIONS Prompt diagnosis of EGPA by the ophthalmologist can decrease patient morbidity and mortality. This requires knowledge of likely ophthalmic EGPA presentations, as well as recommended workups and treatment.
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Sinus pericranii in the upper eyelid: diagnosis and management guidelines. Orbit 2019; 39:422-425. [PMID: 31739717 DOI: 10.1080/01676830.2019.1692874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Sinus pericranii (SP) is a rare malformation involving aberrant connections between the dural venous sinuses and extracranial veins. Classically considered congenital pathology, there are reported instances of post-traumatic SP in adults. Very rarely, the upper eyelid is involved and the resulting ptosis can obstruct the visual axis. In these cases, surgical removal may be warranted. Because of the high risk of massive intraoperative hemorrhage, careful preoperative identification and diagnostic workup is essential. The authors report a patient with new onset, asymmetric eyelid ptosis referred for evaluation, and subsequently diagnosed with SP. Through a multi-disciplinary assessment, deferring surgical intervention was determined to be appropriate management. The lesion was monitored clinically, and at 6 months follow-up, there were no noted adverse outcomes.
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Descemet membrane endothelial keratoplasty for endothelial decompensation after previous radial keratotomy. Am J Ophthalmol Case Rep 2019; 15:100503. [PMID: 31317085 PMCID: PMC6611982 DOI: 10.1016/j.ajoc.2019.100503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/22/2019] [Accepted: 06/25/2019] [Indexed: 11/29/2022] Open
Abstract
Purpose To report Descemet membrane endothelial keratoplasty (DMEK) for endothelial decompensation in an eye with previous radial keratotomy. Observations A history of radial keratotomy may hasten endothelial dysfunction. Previously reported surgical treatments include penetrating kerotoplasty and Descemet stripping automated endothelial keratoplasty. Conclusions and Importance DMEK may be successfully used in post-RK eyes with good recovery of visual acuity and patient satisfaction.
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Occipital tip injury with homonymous central scotoma: OCT-NFL and RGC correlation. Am J Ophthalmol Case Rep 2019; 14:10-13. [PMID: 30766939 PMCID: PMC6360247 DOI: 10.1016/j.ajoc.2019.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/21/2018] [Accepted: 01/20/2019] [Indexed: 11/07/2022] Open
Abstract
Purpose To report one case of homonymous paracentral scotoma with corresponding optical coherence tomography (OCT) findings in a young woman after injury to the left occipital lobe tip. Observations A young woman with past medical history of Hodgkin's lymphoma and large B-cell lymphoma metastatic to the left occipital lobe status post resection presented to the eye clinic with a chief complaint of a “blind spot” in the right eye since her surgery. Humphrey visual field (HVF) showed a right homonymous paracentral scotoma corresponding to the non-decussating and decussating optic radiation for central vision originating from the left lateral geniculate nucleus (LGN). OCT confirmed atrophy of the right nasal hemifovea with fibers originating from the papillomacular bundle and the left temporal hemifovea with fibers originating from the superior temporal segment of the optic nerve. These fibers correspond to the central vision involved with the left posterior occipital lobe tip. Conclusions and Importance We report a case of right homonymous central vision loss as a result of injury to the left posterior occipital lobe tip with certain unique features. Here, a small lesion in the posterior visual pathway led to a relatively large loss of ganglion cell layer.
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Rare Optic Neuropathy in a Jamaican Couple Linked to Cassava Root Consumption. Neuroophthalmology 2018; 44:49-53. [PMID: 32076451 DOI: 10.1080/01658107.2018.1561719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/22/2018] [Accepted: 12/18/2018] [Indexed: 10/27/2022] Open
Abstract
We report central visual loss with selective papillomacular bundle damage in a Jamaican couple, husband and wife, with long-term cassava root consumption. The two cases presented independently with gradual central visual loss. Examination revealed bilateral temporal pallor of the optic nerve head and automated static perimetry demonstrated a central or caecocentral scotoma in each patient. Optical coherence tomography findings are described. The only mutual risk factor, reported independently, was long-term cassava consumption. Cessation of cassava intake and vitamin supplementation resulted in partial recovery of visual function. As thiocyanate levels in urine were not measured, the aetiology in these patients is not definitively confirmed, but chronic cassava consumption should be considered in similar cases as a rare cause of potentially reversible optic neuropathy.
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Growth patterns of survivors of retinoblastoma treated with ophthalmic artery chemosurgery. PLoS One 2018; 13:e0197052. [PMID: 29734385 PMCID: PMC5937785 DOI: 10.1371/journal.pone.0197052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 04/25/2018] [Indexed: 12/31/2022] Open
Abstract
Although studies from pediatric cancers (largely acute lymphoblastic leukemia) have shown that patients undergoing systemic chemotherapy may experience decreased growth velocity during the treatment phase, no such data exist for retinoblastoma patients treated with systemic chemotherapy or ophthalmic artery chemosurgery (OAC). The purpose of this study is to report growth patterns of our retinoblastoma (Rb) population who were treated with OAC in a retrospective, single center (Memorial Sloan Kettering Cancer Center) review of 341 patients treated between 2006 and 2016. Children who only received OAC were classified as naive; those who were treated initially with systemic chemotherapy and subsequently presented to our center for OAC were termed secondary; and a small group of patients who received single-agent systemic chemotherapy prior to OAC were labeled bridge. For all patients, height and weight were recorded at monthly intervals during OAC (short-term) and then annually during a follow-up period (long-term) up to 3 years after treatment. Excluded from this study were children who received external radiation therapy and those with genetic syndromes, which are independently associated with growth derangements. During OAC, there was no significant difference in growth velocity between the naïve and secondary groups. In either group, number of treatments also did not affect growth rate. Three years after the end of OAC, naïve patients were in the 68th percentile by height (95% CI 61.30, 74.63) compared to secondary patients in the 61st percentile (95% CI 51.1, 71.47). Both groups were in the same weight percentiles during the first two years of follow-up but at the three-year follow-up period, naïve patients were in the 63rd percentile (95% CI 57.4, 69.4) and secondary patients were in the 60th percentile (95% CI 50.4, 69.7). OAC for retinoblastoma does not appear to impact short-term growth velocity, weight gain during the treatment period or after three years.
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Comparison of in vitro and in utero ethanol exposure on indices of oxidative stress. IN VITRO & MOLECULAR TOXICOLOGY 2001; 13:281-96. [PMID: 11319279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Prenatal ethanol exposure produces neural tube defects and growth retardation in experimental animals. Because ethanol's teratogenic effects may involve oxidative stress and effects may differ in vitro and in utero, glutathione, cysteine and ATP were evaluated in gestational day 10 rat conceptuses exposed to ethanol. Cultured embryos exposed to ethanol (1.5 or 3.0 mg/mL) maintained a concentration-dependent decrease in glutathione of 21 or 35%, respectively, at 6 h; visceral yolk sac (VYS) glutathione (GSH) decreased by 22 or 18%, respectively, at 3 h. Maternal ethanol exposure (4.5 g/kg) decreased glutathione by 30% in embryos and VYSs at 3 h, but values rebounded. Cultured embryonic cysteine decreased after 30 min by 42% with both doses and after 6 h by 32 or 38% with 1.5 or 3.0 mg/mL, respectively. Ethanol (1.5 mg/mL) increased VYS cysteine by 35% after 30 min. In utero ethanol exposure decreased embryonic cysteine by 58% at 3 h. Ethanol (1.5 mg/mL) decreased adenosine triphosphate (ATP) by 30-60% in embryos and VYSs at 30 min. After 6 h, embryonic ATP decreased by 41 and 30% with 1.5 and 3.0 mg/mL, respectively, while VYS ATP decreased by 38% with 1.5 mg/mL. In utero ethanol exposure decreased ATP by 31% at 3 h in VYSs. While decreases in GSH and cysteine were evident earlier in utero than in vitro, values returned to control suggesting embryos exposed in utero respond rapidly to chemical-induced oxidative stress due to maternal protective mechanisms. Differences between in vitro and in utero responses to ethanol have important implications for interpretation of in vitro developmental studies.
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Abstract
The ubiquitous NAD+ kinase (NADK) is the only known enzyme to catalyze formation of NADP+ from NAD+. The capacity to maintain an adequate supply of NADP(H) has important implications for development because of its requirement as a cofactor and electron donor in biosynthesis and detoxication reactions. Modulation of NADK may directly influence NADP(H) concentrations and cell sensitivity to embryotoxicants. Measurable activities of NADK were not detected in gestational day (GD) 10 rat conceptuses. By GD 11, specific activities of 1.8 and 7.0 pmol NADP+/min/microg protein were measured in embryos and visceral yolk sacs (VYSs), respectively. The VYS specific activities decreased thereafter to 0.5 pmol NADP+/min/microg protein by GD 18. Specific activities of NADK in placenta increased from 1.3 pmol NADP+/min/microg protein on GD 11 to 32.7 pmol NADP+/min/microg protein on GD 15. Specific activities in the liver increased from 1.7 pmol NADP+/min/microg protein on GD 15 to 51.1 pmol NADP+/min/microg protein on GD 21. NADK specific activities were also determined in other developmentally relevant tissues such as the heart and the brain. In the heart, NADK activity was at its lowest just before birth while in the brain it peaked at 5.4 pmol NADP+/min/microg protein just prior to birth. In the lung, activity increased from 0.9 pmol NADP+/min/microg protein on GD 17 to 5.9 pmol NADP+/min/microg protein on GD 21. However, activities dropped in the kidney from 2.0 pmol NADP+/min/microg protein on GD 17 to 1.1 pmol NADP+/min/microg protein on GD 21. These results demonstrate dramatic temporal and spatial variations in NADK activity. Tissue variations in NADK activities may reflect alterations in functional needs for cofactors during differentiation and a cooperation between tissues to optimize detoxification capacity. This is particularly important when chemical exposure during pregnancy disrupts pyridine nucleotide redox status and the conceptus must rely on NADK to provide additional NADP(H).
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Abstract
It is proposed that protection of the developing embryo from chemical and environmental insults that produces oxidative stress requires a proper glutathione (GSH) and pyridine nucleotide status in both the embryo and extra-embryonic membranes. Modulation of pyridine nucleotide flux [NAD(H) and NAD(P)H] in the visceral yolk sac (VYS) by the thiol oxidants diamide and tert-butyl hydroperoxide (tBH) was studied in real time using microfiberoptic sensors in GD 10 rat conceptuses. Consecutive 5-min exposures to 125- and 250-microM diamide resulted in a fluorescence decrease of 14 and 32 Arbitrary Fluorescence Units (AFU). An additional consecutive exposure to 500-microM diamide caused an attenuated decrease followed by a rebound increase of 22 AFU. Consecutive 5-min exposures to tBH at 250 and 500 microM produced fluorescence decreases similar to that of 500 microM diamide, but the decreases were attenuated at 1000 microM. However, there was variability in the rebound increase. A 5-min exposure to tBH (500 microM) alone caused a fluorescence decrease of 14 AFU followed by a rebound increase of 8 AFU. The rate of fluorescence decrease was attenuated by 50% with pretreatment with the glutathione reductase (GSSG-Rd) inhibitor, BCNU (1,3, bis(2 chloroethyl)-1-nitrosourea), indicating that the decrease in surface fluorescence was probably attributable to a decrease in NADPH. Decreases in fluorescence, observed from the surface of the VYS, correlated with decreases in GSH/GSSG ratios in the embryos and the VYS. After exposure to tBH, GSH levels in conceptuses decreased at the end of 5 and 15 min, with a corresponding increase in oxidized glutathione (GSSG) at the end of 3, 5, and 15 min. Our results demonstrate that the increased production of GSSG on exposure to thiol oxidants correlates with a decrease in the reduced pyridine nucleotide, implying the presence of an active GSSG-Rd pathway in the conceptus during organogenesis, and implicating an important role of the pyridine nucleotides in the restoration of GSH homeostasis in the developing rat conceptus during organogenesis.
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Monoclonal antibodies to Escherichia coli ribosomal proteins L9 and L10. Effects on ribosome function and localization of L9 on the surface of the 50 S ribosomal subunit. J Biol Chem 1991; 266:22129-35. [PMID: 1939233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Monoclonal antibodies against Escherichia coli ribosomal proteins L9 and L10 were obtained and their specificity confirmed by Western blot analysis of total ribosomal protein. This was particularly important for the L9 antibody, since the immunizing antigen mixture contained predominantly L11. Each antibody recognized both 70 S ribosomes and 50 S subunits. Affinity-purified antibodies were tested for their effect on in vitro assays of ribosome function. Anti-L10 and anti-L9 inhibited poly(U)-directed polyphenylalanine synthesis almost completely. The antibodies had no effect on subunit association or dissociation and neither antibody inhibited peptidyltransferase activity. Both antibodies inhibited the binding of the ternary complex that consisted of aminoacyl-tRNA, guanylyl beta, gamma-methylenediphosphonate, and elongation factor Tu, and the binding of elongation factor G to the ribosome. The intact antibodies were more potent inhibitors than the Fab fragments. In contrast to the previously established location of L10 at the base of the L7/L12 stalk near the factor-binding site, the site of anti-L9 binding to 50 S subunits was shown by immune electron microscopy to be on the L1 lateral protuberance opposite the L7/L12 stalk as viewed in the quasisymmetric projection. The inhibition of factor binding by both antibodies, although consistent with established properties of L10 in the ribosome, suggests a long range effect on subunit structure that is triggered by the binding of anti-L9.
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