Expression and lysosomal targeting of CLN7, a major facilitator superfamily transporter associated with variant late-infantile neuronal ceroid lipofuscinosis.

Neuronal ceroid lipofuscinoses (NCLs) constitute a group of progressive neurodegenerative disorders resulting from mutations in at least eight different genes. Mutations in the most recently identified NCL gene, MFSD8/CLN7, underlie a variant of late-infantile NCL (vLINCL). The MFSD8/CLN7 gene encodes a polytopic protein with unknown function, which shares homology with ion-coupled membrane transporters. In this study, we confirmed the lysosomal localization of the native CLN7 protein. This localization of CLN7 is not impaired by the presence of pathogenic missense mutations or after genetic ablation of the N-glycans. Expression of chimeric and full-length constructs showed that lysosomal targeting of CLN7 is mainly determined by an N-terminal dileucine motif, which specifically binds to the heterotetrameric adaptor AP-1 in vitro. We also show that CLN7 mRNA is more abundant in neurons than astrocytes and microglia, and that it is expressed throughout rat brain, with increased levels in the granular layer of cerebellum and hippocampal pyramidal cells. Interestingly, this cellular and regional distribution is in good agreement with the autofluorescent lysosomal storage and cell loss patterns found in brains from CLN7-defective patients. Overall, these data highlight lysosomes as the primary site of action for CLN7, and suggest that the pathophysiology underpinning CLN7-associated vLINCL is a cell-autonomous process.

Bovine pericardium as a wrapping for orbital implants.

PURPOSE: We report the use of bovine pericardium as an alternative wrapping for porous orbital implants after enucleation. METHODS: We retrospectively reviewed the records of all patients who received a bovine pericardium-wrapped orbital implant after enucleation by the authors between August 1, 1996, and December 1, 1999. RESULTS: Eighty patients underwent placement of bovine pericardium-wrapped orbital implants. The average age at the time of implantation was 49.3 years (range, 5 years to 83 years). The mean follow-up interval was 11.8 months (range, 2 to 41 months). There were no intraoperative complications. No patient had secondary systemic infection or showed evidence of rejection. There was no clinical evidence to suggest that vascularization of the porous implant was unusually delayed, and there were no complications after secondary drilling and placement of a coupling post. Four (5%) of 80 patients had complications requiring removal of the spherical implant. All 4 patients had hydroxyapatite implants. Two patients had significant exposure requiring removal of the implant at 2 months after surgery; 1 patient had a chronic fistulous tract with secondary infection 3 years after surgery: and 1 patient had chronic orbital pain requiring removal of the implant at 1 year after surgery. CONCLUSIONS: The incidence of implant exposure was less than 4%. This compares favorably to the incidence of exposure of 9% to 21% reported in recent literature. Other complications were few and of minimal clinical significance. The authors conclude that bovine pericardium is a viable option to sclera as a wrapping for porous orbital implants.

Multiple recurrences in malignant peripheral nerve sheath tumor of the orbit: a case report and a review of the literature.

PURPOSE: To report the onset of malignant peripheral nerve sheath tumor of the orbit 8 years after irradiation in a patient with neurofibromatosis type-1. METHODS: Case report of a young man with neurofibromatosis type-1 who received irradiation for presumed bilateral optic nerve and chiasmal gliomas and in whom a malignant peripheral nerve sheath tumor later developed. Exenteration with extirpation of the entire contents of the orbit was performed 6 times. RESULTS: Complete recurrence of the tumor occurred after each surgical procedure until the patient died of malignancy. CONCLUSIONS: Our case underscores the risk of irradiation, especially in children with neurofibromatosis type-1, and emphasizes that radiotherapy should never be given as an empirical therapy. The authors believe that irradiation and neurofibromatosis type-1 may, in combination, pose a significant risk for the development of malignancies. Clear-cut indications and a precise tissue diagnosis are desirable before the initiation of radiotherapy, particularly in the pediatric population. We recommend that if irradiation is necessary in persons with neurofibromatosis type-1, regular follow-up is imperative. In view of the hostile nature of malignant peripheral nerve sheath tumor, early aggressive treatment appears to be the only viable alternative at present.

Blepharoptosis-induced superior keratoconus.

PURPOSE: This clinical case report demonstrates blepharoptosis-induced corneal steepening and its subsequent resolution after blepharoptosis surgery. METHODS: A 62-year-old man complaining of blurred vision without apparent cause on clinical examination underwent keratometry and computerized corneal topography, which revealed superior corneal steepening in both eyes. Bilateral upper eyelid blepharoptosis surgery was performed. RESULTS: Three months after blepharoptosis surgery, repeat computerized corneal topography revealed normal corneal contours with improved vision in both eyes. CONCLUSIONS: Blepharoptosis is a common condition that may induce superior corneal ectasia that is not evident by manifest refraction, slit-lamp examination, or keratometry. Computerized corneal topography can help detect such subtle corneal abnormalities and guide therapy.

Orbital Ewing's sarcoma of the orbit.

PURPOSE: Ewing's tumor is a primary tumor of bone in childhood that only rarely involves the orbit. Most such cases are metastatic from distant sites. This tumor may be confused with other small round cell malignancies of childhood, and immunohistochemical studies are essential in making the diagnosis. METHODS: We present two cases of Ewing's tumor of the orbit. One was in a 22-year-old boy with an occult primary tumor in the frontal bone that became symptomatic after forehead trauma. The other example was in a 7-year-old boy with a known Ewing's primary of the clavicle. The clinical manifestations and diagnostic criteria are discussed. RESULTS: In most cases with orbital involvement, ophthalmic symptoms consist of proptosis, pain, and occasionally visual loss and motility restriction. The diagnosis is typically unsuspected before histologic evaluation. Electron microscopic and immunohistochemical analyses are essential in making the diagnosis and are necessary for all such small round cell tumors. CONCLUSIONS: Ewing's sarcoma is a rare orbital tumor of bone mainly affecting children. Local treatment relying on surgical extirpation and radiotherapy alone has proven inadequate, with 5-year survival rates of <10%. The addition of chemotherapy has improved survival rates significantly to approximately 50%.

Anterior tarsal V-wedge resection for cicatricial entropion.

PURPOSE: To determine the effectiveness of using a radiofrequency instrument to resect a V-shaped tarsal wedge for the correction of cicatricial upper eyelid entropion. METHODS: Prospective evaluation of 16 upper eyelids of 11 consecutive patients. RESULTS: The operation was successful in all 16 eyelids, with excellent cosmetic and functional outcomes. CONCLUSIONS: Tarsal V-wedge resection is an effective alternative to other complicated techniques in the management of upper eyelid cicatricial entropion.

Direct internal eyelash bulb extirpation for trichiasis.

PURPOSE: To evaluate the success of internal eyelash bulb extirpation in the management of trichiasis. METHODS: The procedure was performed on 26 consecutive eyelids. RESULTS: Our technique was successful in all cases, with no recurrence of signs or symptoms. CONCLUSIONS: Internal eyelash bulb extirpation is a safe and effective technique to remove trichiatic lashes, while avoiding injury to the conjunctiva.

A comparative study of bovine pericardium (periguard) and homologous sclera as lower eyelid spacer graft analogs in New Zealand white rabbits.

PURPOSE: To compare bovine pericardium (Periguard; Bio-Vascular, Inc., St. Paul, MN, U.S.A.) and homologous sclera as spacer graft analogs in a rabbit model. METHODS: A nonrandomized experimental animal study was conducted. Elliptical subconjunctival implants were placed in one lower eyelid each of 10 rabbits. Five rabbits received homologous sclera implants, and five received bovine pericardium implants. The rabbits were killed 7 weeks later, and the lower eyelids were examined clinically and histopathologically. RESULTS: Rabbit eyelids implanted with Periguard had a more marked inflammatory reaction and more significant collagen lamellar disruption than eyelids implanted with homologous sclera, although clinically they appeared quite similar. CONCLUSIONS: Although bovine pericardium elicited a more intense inflammatory response at the histopathologic level, both implants were similarly tolerated at the clinical level. These findings are consistent with animal and human investigations of bovine pericardium in other parts of the body, and warrant further studies into its potential use in the human eyelid.

The influence of hyperbaric oxygen therapy and irradiation on hydroxyapatite ocular implant exposure and fibrovascular ingrowth in New Zealand white rabbits.

PURPOSE: Lack of adequate fibrovascular ingrowth has been implicated as a cause of exposure of hydroxyapatite (HA) implants in anophthalmic sockets. We investigated the vasculopathic effects of external beam irradiation, and the fibrovascular-enhancement effects of hyperbaric oxygen (HBO), on HA implant exposure and fibrovascular ingrowth in a rabbit model. METHODS: Eighteen rabbits underwent enucleation with implantation of a 12-mm HA sphere. Six rabbits received 20 Gy of external beam orbital irradiation prior to enucleation. Three irradiated and 6 nonirradiated rabbits received postoperative HBO. Three weeks postoperatively, all rabbits were evaluated clinically for evidence of implant exposure. Implants were then removed, and histopathologic analysis of fibrovascular ingrowth was performed. RESULTS: The amount of vascularization as measured by the depth of ingrowth was greater for nonirradiated (89% ingrowth) than for irradiated (71% ingrowth) animals. HA implant exposure occurred in 1 of 12 (8%) of the nonirradiated, and 4 of 6 (67%) of the irradiated rabbit orbits. HBO did not protect irradiated rabbits from exposure, but did enhance fibrovascular ingrowth in nonirradiated rabbits (100% ingrowth vs. 77% ingrowth). CONCLUSION: Impaired orbital vascularization from prior irradiation appears to retard fibrovascular ingrowth into HA implants, and is associated with an increased incidence of exposure. While HBO did not diminish the likelihood of exposure in irradiated sockets, HA fibrovascular ingrowth in normal orbits appeared to increase with HBO. This may have beneficial clinical application in cases of exposure in nonirradiated orbits.

Bovine pericardium versus homologous sclera as wrapping materials for hydroxyapatite ocular implants: an animal study.

PURPOSE: We compared bovine pericardium and homologous sclera as wrapping materials for hydroxyapatite (HA) ocular implants in enucleated New Zealand white rabbits. METHODS: Eighteen rabbits were unilaterally enucleated and the sockets implanted with 10-mm HA spherical implants. Six implants were wrapped with homologous sclera, 6 with bovine pericardium, and 6 were not wrapped. The rabbits were killed 7 weeks later and the sockets were examined clinically for inflammation and implant exposure. Exenterated specimens were assessed histopathologically for inflammation and vascularization. RESULTS: No clinical evidence of implant exposure or extrusion was detected in rabbits receiving sclera or bovine pericardium wrapped implants. Histopathologically, the bovine pericardium displayed more inflammation in its outer portion, as well as more disruption of its lamellar arrangement than did the sclera. Fibrovascular in-growth was complete in all wrapped implants. CONCLUSION: Bovine pericardium behaves similar clinically to homologous sclera as a wrapping material for spherical HA ocular implants in a rabbit model, and may represent a reasonable alternative to sclera in such procedures in humans.

Embryonic expression of the human GATA-3 gene.

The spatial and temporal analysis of GATA-3 expression pattern in the human embryo revealed its expression in new anatomical sites. These include the endoderm of the primitive foregut, pharynx and allantois, the branchial arches and the mesenchymal cells surrounding the stomach and dorsal aorta. On the other hand, human (h) GATA-3 expression in the central nervous system, somites and embryonic kidney confirms the tissue specificity of this gene throughout vertebrate evolution.

Differential expression of KDR/VEGFR-2 and CD34 during mesoderm development of the early human embryo.

Recent findings on vertebrate embryos have provided compelling evidence for the existence of hemangioblasts, i.e. common precursors for endothelial and hematopoietic cells, characterized by expression of the VEGFR2/Flk1 receptor. We describe here a population of KDR+ CD34- mesoderm cells that emerges in early-somitic human embryos, by the beginning of the 4th week of gestation. In the developing blood vessels, KDR-expressing CD34- cells gradually coexpress increasing levels of CD34 antigen. Remarkably, as development proceeds, a KDR+ CD34- contingent persists in the paraaortic splanchnopleura until just prior to the emergence of aorta-associated hematopoietic cell clusters. These observations suggest that KDR+ CD34- mesodermal cells might represent the putative hemangioblastic precursor of human hematopoietic and endothelial lineages.

Decrease in intraocular pressure after orbital decompression for thyroid orbitopathy.

BACKGROUND: The effect of thyroid orbitopathy on intraocular pressure (IOP) remains controversial. We carried out a study to determine the effect of orbital decompression surgery on the IOP in patients with advanced thyroid orbitopathy. METHODS: The records of 12 consecutive patients (22 eyes) who underwent decompression surgery for severe thyroid orbitopathy between 1985 and 1996 were reviewed. All patients were maintained on essentially the same medications before and after surgery. The IOP readings, obtained by means of applanation tonometry in primary gaze, from the pre- and postoperative visits were recorded, and the net change was calculated. RESULTS: The mean preoperative and postoperative IOP values were 19.8 mm Hg and 16.8 mm Hg respectively, a significant difference (p = 0.008). Seven of eight eyes with an IOP of 21 mm Hg or greater preoperatively had a postoperative IOP less than 21 mm Hg; these eyes showed a mean decrease in IOP of 5.6 mm Hg. The degree of preoperative IOP elevation was found to be a strong predictor of the amount of IOP lowering after surgery (p = 0.014). INTERPRETATION: Our results support the concept that orbital congestion associated with thyroid orbitopathy produces an increase in IOP by elevation of episcleral venous pressure (EVP) and that orbital decompression may reduce the IOP by decreasing EVP. Decompression surgery may obviate the need for more aggressive management of glaucoma in patients with severe thyroid orbitopathy.

Age-related changes in type-I collagen synthesis in human eyelid skin.

PURPOSE: This study was to determine whether age-related decrements in type I collagen synthesis occur in human eyelid skin. METHODS: Using an antibody to procollagen I, we investigated collagen synthetic activity in skin removed for cosmetic purposes from 10 white patients between the ages of 4 and 77 years. Eleven masked referees graded the immunostaining on a scale of 1 (most intense) to 10 (least intense). RESULTS: The multiple range test for rank by group demonstrated more intense staining in younger patients compared with older patients. An average correlation coefficient of 0.8432 (p < 0.05) existed between each of the referee's rankings. CONCLUSION: Type I collagen synthesis diminishes with age in eyelid skin.

Hemorrhagic cyst following remote alloplastic implantation for orbital floor fracture repair.

Hemorrhagic cyst formation may occur within months or years following repair of orbital fractures with alloplastic materials. Patients present with a sensation of pressure in the involved orbit, double vision, and globe displacement. Evaluation must rule out infectious, inflammatory, and vascular etiologies. Computerized tomography scans reveal a soft tissue density surrounding the alloplastic implant. Drainage of the cyst and fibrous capsule, with excision of the capsule and removal of the alloplastic implant, is curative. This article presents three clinical cases, highlighting the evaluation and management of this postsurgical development. Use of the protocol described resulted in complete resolution of all clinical symptoms, and the CT scans were normal. As these materials will continue to be utilized, surgeons should be aware of this potential delayed complication and its management.

Deviated hydroxyapatite orbital implant syndrome.

PURPOSE: To describe a patient with a deviated orbital implant after enucleation. METHOD: Case report. RESULT: We examined a postenucleation patient with a medially deviated ("esotropic") implant after peg drilling. Modification of the posterior surface of the prosthesis improved cosmesis in the primary position. CONCLUSIONS: During enucleation surgery, surgeons may use a spherical implant rather than modify the anterior face in patients with preexisting strabismus, with severe trauma to the extraocular muscles, or with risk of implant deviation. Additionally, secondary procedures may alter implant position. Occasionally, patients without obvious preoperative risk factors may have deviation of the modified face of the implant. Flattening the implant creates an asymmetric surface that may lead to a deviated orbital implant.

Lower eyelid recession combined with ptosis surgery in patients with poor ocular motility.

BACKGROUND: The authors treated ten patients (13 eyelids) with visually significant blepharoptosis and compromised corneal protective mechanisms resulting from paresis of ocular motility and absent Bell phenomenon. METHODS: Traditional upper eyelid surgery consisting of frontalis suspension (6 eyelids) or levator aponeurosis advancement (7 eyelids) was used. In all patients, the ptosis repair was combined with maximum recession of the lower eyelid, using a posterior lamellar scleral spacer graft. The goal was to maintain a narrow, vertical, interpalpebral fissure to allow for eyelid closure, but to reposition this opening centrally over the pupil. RESULTS: Postoperatively, all patients achieved significant improvement in superior visual field, with no associated keratopathy. Complications were few, minor, and transient. The postoperative cosmetic appearance was acceptable in all patients. CONCLUSIONS: This combined procedure allows repair of fair- to poor-function ptosis in patients in whom ptosis surgery previously has been considered risky. For the authors, this technique has been proven safe and effective and should be considered in any patient population with compromised corneal protective mechanisms.

Melanotransferrin gene expression in melanoma cells is correlated with high levels of Jun/Fos family transcripts and with the presence of a specific AP1-dependent ternary complex.

The involvement of the transcription factor AP1 in the regulation of melanotransferrin (MTf) gene expression was investigated. MTf, also known as p97, is a tumour-associated antigen that is overproduced in most melanomas. Its gene expression is under the control of an enhancer element containing two AP1 binding sites. By Northern analysis, we demonstrate that MTf mRNA is detected at various levels in melanoma SK-MEL-28 cells and that its greatest expression coincides with the presence of large amounts of jun and fos transcripts. Gel retardation assays revealed that the induction of expression of these proto-oncogenes is correlated with increased AP1 binding activity and that a region of the MTf enhancer is involved in the formation of a ternary AP1-dependent complex, implicating a second nuclear factor whose binding characteristics are similar to those of nuclear factor of activated T cells (NF-AT). In transient expression experiments, the activity resulting from ternary complex formation was high and specific to melanoma cells. These data provide a possible explanation for the mechanisms of AP1 factor family involvement in MTf up-regulation in melanoma cells.

Solitary fibrous tumor of the orbit.

PURPOSE: We studied a case of solitary fibrous tumor of the orbit in a 75-year-old man. METHODS: The patient had painless, slowly progressive proptosis of eight months' duration. He underwent magnetic resonance imaging, which showed a well-circumscribed retrobulbar mass. The tumor was excised. RESULTS: Examination of the tumor disclosed haphazardly arranged spindle cells alternating with collagenous, hypocellular areas in a richly vascular background without necrosis. Immunoperoxidase stains showed characteristic expression of CD34 and vimentin. CONCLUSION: Solitary fibrous tumor can infrequently involve the orbit and may recur locally and metastasize, necessitating long-term follow-up.

Differential care of corneal ulcers in the community based on apparent severity.

PURPOSE: To describe current practice patterns in treating infectious keratitis. METHODS: A questionnaire was designed that asked ophthalmologists to describe the diagnostic equipment accessible to their practice for performing smears and obtaining scrapings for microbial culture and sensitivity testing. The questionnaire also presented two hypothetical cases of patients with infectious keratitis. Bacterial keratitis was relatively early and less severe in the first patient, and it was more advanced and more severe in the second patient. Recipients were asked about their diagnostic and therapeutic approach. The survey was mailed to 300 ophthalmologists in Florida, Illinois, and New York. RESULTS: One hundred twenty-four completed surveys (45%) were returned. Six surveys were from cornea specialists, who were excluded from the analysis. Only 18 practices (15%) maintained access to Gram stain supplies, and 58 (50%) maintained culture supplies. Whereas 56% of respondents would treat the patient with the less severe bacterial keratitis without obtaining samples for cultures, only 13% would treat the patient with the more severe condition in this manner (P<0.00001). Of the respondents, 82% would treat the patient with the less severe bacterial keratitis with a fluoroquinolone, compared with 62% for the patient with the more severe infection (P=0.002). The mean frequency of fluoroquinolone administration for the patient with more-severe bacterial keratitis was one drop every 0.88 hours, compared with one drop every 1.48 hours for the patient with the less severe infection. CONCLUSIONS: Ophthalmologists appear to treat suspected infectious keratitis differently, depending on perceived severity; they choose different antibiotic regimens; and are more likely to forgo scrapings for Gram staining and cultures for ulcers that appear less severe. The justification for this approach should be established.