An animal study on the effect of topically administered ambroxol for dry eye.

OBJECTIVE: To evaluate the effect of 0.2% ambroxol eye drop on tear secretion and corneal healing on a rabbit dry eye model, and to delineate potential underlying mechanisms. MATERIALS AND METHOD: A mixed mechanism dry eye model was created using 12 healthy New Zealand rabbits by excision of the main lacrimal glands, Harderian gland and nictitating membrane. Establishment of the model was confirmed by the decrease of Schirmer I and increase of corneal fluorescein staining scores. Two weeks after model creation, the rabbits were randomly and evenly divided into NaCl, 0.1% sodium hyaluronate and 0.2% ambroxol groups. Each group was administered the respective eye drops 4 times a day for four weeks. The Schirmer I test and corneal fluorescein staining were performed at two and four weeks. After four weeks of treatment, the animals were sacrificed and the conjunctiva and eyelid specimens collected. Inflammatory factors IL-8, TNF-α, and goblet cell specific mucin MUC5AC were measured by ELISA while the lid meibomian gland was evaluated by oil red O staining. RESULTS: Compared with the baseline, 2 weeks after the surgery, Schirmer I test value decreased significantly (20.35 ± 5.18 mm/5 min vs 13.95 ± 4.64 mm/5 min, p < 0.01), and the fluorescein staining score increased significantly (0.5 ± 0.6 vs 5.5 ± 1.4, p < 0.01). After four weeks of treatment, compared with the NaCl and sodium hyaluronate groups, tear secretion in ambroxol group increased significantly (p < 0.01), while the corneal fluorescence staining score decreased significantly (p < 0.01). In the conjunctival tissue, significant decrease was seen in TNF-α (p < 0.01) and IL-8 [p (unilateral) < 0.05] concentrations in ambroxol group, and significant increase in MUC5AC concentration (p < 0.01) in ambroxol group as well. The lipid content in the lid meibomian glands appeared increased after the administration of ambroxol. CONCLUSION: The present rabbit dry eye model study demonstrated potentials of topically administered 0.2% ambroxol in stimulating tear and mucin secretion, inhibiting ocular surface inflammation, promoting corneal healing, and possibly augmenting meibomian gland lipid production.

Corneal Crosslinking Biomechanics Evaluated by a Novel and Easily Implemented Differential Tonometry Method.

Purpose: Evaluate potential corneal biomechanical changes following corneal crosslinking (CXL) by paired differential tonometry intraocular pressure (IOP) measurements with a Goldmann tonometer (GAT) prism and corneal compensating, correcting applanation tonometry surface (CATS) prism.Methods: IOP was measured prospectively on 23 unique eyes undergoing CXL for keratoconus with a GAT using a standard flat GAT prism and a curved corneal error correcting CATS prism before treatment and at 2 weeks, 2 months and 6 months after treatment. Concurrent measurements of central corneal thickness (CCT) and corneal hysteresis (CH) were completed.Results: Paired IOP measurements with standard GAT and corneal correcting CATS prisms indicated a significant sustained relative increase in the differential IOP between the two prisms after CXL (p = .002,0.051,0.062). CH initially decreased at two weeks post-CXL then returned to sustained pre-op levels (p = .033,0.20,0.20). CCT progressively decreased following CXL (p = .005).Discussion: Differential tonometry between standard GAT and corneal biomechanical compensating CATS prisms indicates findings consistent with increased corneal rigidity following CXL and may demonstrate a simple and sensitive method for measurement of relative corneal biomechanical changes due to pharmacologic agents and procedures.

Adverse Events of Intense Pulsed Light Combined With Meibomian Gland Expression Versus Meibomian Gland Expression in the Treatment of Meibomian Gland Dysfunction.

BACKGROUND AND OBJECTIVE: To analyze the occurrence and causes of adverse events (AEs) in intense pulsed light (IPL) combined with meibomian gland expression (MGX) and MGX treatment alone for meibomian gland dysfunction (MGD). STUDY DESIGN/MATERIALS AND METHODS: A retrospective study was conducted on MGD patients treated in Wuhan Aier Hankou Eye Hospital from February 2018 to October 2019 to compare the AEs between IPL-MGX and MGX groups. Relevant AEs that occurred during the treatment and within 1 month after the patients' last treatment were recorded and the causes of the AEs were analyzed. RESULTS: A total of 2,282 patients received IPL-MGX and 1,407 received MGX treatment. No serious AEs occurred in both groups. There were 74 AEs in the IPL-MGX group, with an incidence of 3.24%, including 14 significant AEs (2 cases of epidemic keratoconjunctivitis, 1 recurrent herpes simplex keratitis (HSK), 9 new onsets of floaters, 1 recurrent glaucomatocyclitic crises, and 1 recurrent iridocyclitis). There were 27 AEs in the MGX group with a rate of 1.92%, including 4 significant AEs (2 cases of keratoconjunctivitis epidemic, 2 new cases of floaters). Compared with the IPL-MGX group, the incidence of AEs in the MGX group was lower (P = 0.017). CONCLUSIONS: Both IPL-MGX and MGX treatment are safe therapies with low risk for AEs. IPL treatment is not recommended for young children (age 10 or less) as well as patients with anterior uveitis or glaucomatocyclitic crises. The previous history of HSK and eyes with high myopia are advised to exercise caution in IPL treatment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Evaluation of the Safety and Efficacy of a Low-Temperature Plasma Surgical System for Pterygium.

PURPOSE: Surgical excision is the standard treatment for pterygium. This study was conducted to evaluate the safety and efficacy of a novel technique using low-temperature plasma (LTP) for excision and hemostasis in pterygium surgery. METHODS: A prospective, comparative, and randomized clinical trial was conducted on 60 patients (60 eyes) undergoing pterygium excision with conjunctival autografts using fibrin glue. Patients were equally divided into the following 2 groups: a control group and a LTP group. Postoperative follow-up visits were scheduled on day 1, week 1, and months 1 and 3, and recurrence was evaluated at 1 year. Patients were examined for operative time, best corrected visual acuity, conjunctival autograft inflammation (CAI), graft stability (GS), pain, recurrence, and final appearance. Factors related to pterygium recurrence and final appearance were analyzed. RESULTS: Mean operative times were shorter in the LTP group (16.7 ± 3.4 min) than those in the control group (20.1 ± 4.7 min, P = 0.002). LTP eyes had milder CAI than control eyes at postoperative day 1 (P = 0.000) and week 1 (P = 0.000). Patients in the LTP group exhibited better GS (P = 0.01) and milder pain (P = 0.04) than those in the control group on day 1. Two control patients (6.7%) and no (0%) LTP patients experienced recurrence (P = 0.08). GS and CAI were the significant factors contributing to recurrence (GS: R = 0.425, P = 0.001; CAI: R = 0.309, P = 0.016). CONCLUSIONS: LTP to replace surgical blades and disposable cautery for ablation and hemostasis is safe and efficient for pterygium surgery, resulting in shorter operative time, milder inflammation, and better graft stability without increasing complication risk.

Human lens epithelial cell apoptosis and epithelial to mesenchymal transition in femtosecond laser-assisted cataract surgery.

AIM: To evaluate human lens epithelium cell apoptosis and epithelial to mesenchymal transition (EMT) induced by femtosecond laser in femtosecond laser assisted cataract surgery (FLACS). METHODS: Sixty cataract patients with N2 to N3 stage according to the LOCS III were enrolled in this study and divided into three groups randomly: FLACS1 group (cataract surgery by FLACS with LenSx), FLACS2 group (cataract surgery by FLACS with LensAR) and manual group (cataract surgery by phacoemulsification). Patients in two FLACS groups performed anterior capsulotomy by LenSx or LensAR laser system. Patients in the manual group were performed continuous curvilinear capsulorrhexis (CCC) manually. The anterior capsules were fixed right after moved out of eye. Hematoxylin-eosine staining, immunofluorescence staining and real-time PCR were performed in order to observe human lens epithelium cells changes after cataract surgery. RESULTS: The capsule cutting edge was shown irregularity and roughness in two FLACS groups and smooth edge in manual capsulotomy by pathologic staining. Irregularities of the cell configuration with partly swollen and destroyed nuclei were observed in two FLACS groups. Femtosecond laser could induce a significantly higher cell apoptosis in human lens epithelium cell than manually performed CCC (P<0.05). Lens epithelium cells apoptosis were correlated with femtosecond laser duration according to Pearson correlation analysis. Decreased N-cadherin expression, alpha-SMA and FSP-1 level in two FLACS groups showed the inhibition of cell EMT. CONCLUSION: Femtosecond laser may affect the apoptosis and EMT of lens epithelium cells which are under the peeled central lens capsule.

Excisional keratectomy combined with focal cryotherapy and amniotic membrane inlay for recalcitrant filamentary fungal keratitis: A retrospective comparative clinical data analysis.

The aim of the present study was to investigate the efficacy of a novel surgical intervention, excisional keratectomy combined with focal cryotherapy and amniotic membrane inlay (EKCAI), for the treatment of recalcitrant filamentary fungal keratitis. A retrospective analysis was performed of patients who underwent excisional keratectomy combined with conjunctival flap inlay (EKCFI), EKCAI or therapeutic penetrating keratoplasty (TPK) from January 2006 to January 2011. Recalcitrance was determined as being unresponsive to standard medical antifungal therapy for at ≥1 week. Outcome measures among the three intervention modalities were compared. A total of 128 patients had a follow-up of ≥1 year after the primary intervention. The success rates of interventions at 1-year follow-up were 58.33% in the EKCFI group, 88.37% in the EKCAI group and 93.44% in the TPK group (P<0.0002). The preoperative visual acuity of the three groups were similar (P=0.6458), while the postoperative best-corrected visual acuity (BCVA) of patients without recurrence was significantly different among the three groups 3 months after surgery. The best postoperative BCVA was found in the TPK group, while the worst was in the EKCFI group. In conclusion, EKCAI does not require donor cornea, is straightforward surgically, and has a favorable success rate compared with EKCFI.

Optimal incision sites to reduce corneal aberration variations after small incision phacoemulsification cataract surgery.

AIM: To analyze the effect of steep meridian small incision phacoemulsification cataract surgery on anterior, posterior and total corneal wavefront aberration. METHODS: Steep meridian small incision phacoemulsification cataract surgery was performed in age-related cataract patients which were divided into three groups according to the incision site: 12 o'clock, 9 o'clock and between 9 and 12 o'clock (BENT) incision groups. The preoperative and 3-month postoperative root mean square (RMS) values of anterior, posterior and total corneal wavefront aberration including coma, spherical aberration, and total higher-order aberrations (HOAs), were measured by Pentacam scheimpflug imaging. The mean preoperative and postoperative corneal wavefront aberrations were documented. RESULTS: Total corneal aberration and total lower-order aberrations decreased significantly in three groups after operation. RMS value of total HOAs decreased significantly postoperatively in the 12 o'clock incision group (P<0.001). Corneal spherical aberration was statistically significantly lower after steep meridian small incision phacoemulsification cataract surgery in BENT incision group (P<0.05) and Pearson correlation analysis indicated that spherical aberration changes had no significant relationship with total astigmatism changes in all three corneal incision location. CONCLUSION: Corneal incision of phacoemulsification cataract surgery can affect corneal wavefront aberration. The 12 o'clock corneal incision eliminated more HOAs and the spherical aberrations decreased in BENT incision group obviously when we selected steep meridian small incision. Cataract lens replacement using wavefront-corrected intraocular lens combined with optimized corneal incision site would improve ocular aberration results.

Evaluating the Functionality of Conjunctiva Using a Rabbit Dry Eye Model.

Purpose. To assess the conjunctival functionality in a rabbit dry eye (DE) model. Methods. Nictitating membrane, lacrimal and Harderian glands were surgically excised from male New Zealand white rabbits using minimally invasive surgery. Fluorescein/rose Bengal staining of ocular surface (OS) and Schirmer test were done before (BE) and after excision (AE). The expression of interleukin- (IL-) 1ß, tumor necrosis factor- (TNF-) α, and MUC5AC proteins were estimated by immunoblotting from conjunctival impression cytology specimens. MUC5AC mRNA was quantified as well. The effect of epithelial sodium channel (ENaC) blockers on tear production and potential differences (PD) of OS were assessed under anesthesia in rabbits with and without surgery. Results. Increase in corneal and conjunctival staining was observed 1 month AE compared to BE. Schirmer tests failed to show decrease in tear production. Elevated IL-1ß, and TNF-α, 1 month AE indicated inflammation. MUC5AC expression was elevated 1 month AE. ENaC blockers did not improve tear production in rabbit eyes AE but characteristic changes in PD were observed in rabbits with surgery. Conclusions. DE biomarkers are important tools for OS assessment and MUC5AC expression is elevated in rabbit DE. PD measurement revealed significant electrophysiological changes in rabbits with surgery.

Follicular Lymphoma Presenting Solely as Chronic Follicular Conjunctivitis.

PURPOSE: Conjunctival lymphoma rarely can have atypical clinical presentations. The authors report a case of conjunctival follicular lymphoma that presented solely as bilateral chronic follicular conjunctivitis. This case underscores that the pathological characteristics of conjunctival follicles can only be determined by histopathologic examination. METHODS: The patient underwent conjunctival scraping and biopsy after clinical history and examination failed to reveal the etiology of his chronic, symptomatic, follicular conjunctivitis. RESULTS: Histopathologic and immunohistochemical testing disclosed a bilateral low-grade conjunctival follicular lymphoma. The patient was treated with radiation therapy and remained in remission clinically 6 months after the treatment. CONCLUSIONS: Although rare, conjunctival lymphoma should be included in the differential diagnosis of chronic follicular conjunctivitis. This case is unique and further supports the notion that tissue biopsy may be needed for chronic, symptomatic conjunctivitis of unknown etiology.

Tear Production After Bilateral Main Lacrimal Gland Resection in Rabbits.

PURPOSE: This study reports tear compensation observed in rabbits with bilateral resection of main lacrimal gland (LG) and explored the potential mechanisms. METHODS: Dry eye conditions were created by resection of nictitating membrane (NM), Harderian gland (HG), and main LG in eight (16 eyes) male New Zealand White rabbits. In addition to Schirmer test, Periodic acid-Schiff (PAS) staining, and ocular surface staining with fluorescein and rose Bengal, conjunctival impression cytology was employed before and up to 4 months after excision (AE). Using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), expression of inflammatory biomarkers (IL-1ß, TNF-α, and matrix metalloproteinase-9) were monitored. Further, involvement of ionic and water transporters were investigated in conjunctival epithelium. RESULTS: Significant dry eye phenotypes in rabbits were observed 1 month AE, which corroborated with elevated biomarker mRNA expression. However, Schirmer test score and goblet cell numbers never decreased AE in conjunctival epithelium. Moreover, ocular surface staining, and biomarker expression declined to baseline in over 4 months AE. No upregulation was observed of the following conjunctival ionic transporters: cystic fibrosis transmembrane conductance regulator, sodium potassium chloride cotransporters, sodium potassium ATPase, and epithelial sodium channels. Instead, aquaporin (AQP) 4 and AQP5 were upregulated. Immunolocalization and immune blotting of AQP4 was demonstrated in rabbit conjunctival epithelium. CONCLUSIONS: In the absence of NM, HG, and main LG in rabbits, tear secretion was not decreased and significant improvement of dry eye phenotypes observed with time AE. Conjunctival AQPs are possibly involved in a compensatory tear fluid production.

ENaC in the Rabbit Lacrimal Gland and its Changes During Sjögren Syndrome and Pregnancy.

PURPOSE: Epithelial sodium channel (ENaC) plays a critical role in the control of Na(+) balance and the development and progression of exocrine gland pathologic condition. The aim of the present study was to investigate the presence of ENaC in the rabbit lacrimal gland (LG) and its potential changes during induced autoimmune dacryoadenitis (IAD) and pregnancy. METHODS: Total messenger RNA (mRNA) of α, ß, and γ subunits was extracted from whole LG, acinar cells, and ductal cells by laser capture microdissection (LCM) for real-time reverse-transcriptase polymerase chain reaction. Lacrimal glands were processed for Western blot and immunofluorescence. RESULTS: Messenger RNA for both α and γ was expressed in whole LG lysates, whereas ß was undetectable. In rabbits with IAD, the levels of mRNA for α and γ were 20.9% and 58.9% lower (P<0.05), whereas no significant changes were observed in term-pregnant rabbits (P=0.152). However, we were unable to detect mRNA of any subunit in LCM specimens of ductal cells because of their low levels. Western blot demonstrated bands for both α (90 kDa) and γ (85 kDa) but ß was undetectable. In rabbits with IAD, densitometry analysis showed that expression of α decreased 22%, whereas γ decreased 26% (P<0.05). In pregnant rabbits, however, α expression was 31% lower, whereas γ expression was 34% lower (P<0.05). From immunofluorescence studies, all subunits were present in ductal cells, whereas virtually no immunoreactivity was detected in acini. No noticeable changes of their distribution pattern and intensity were found in rabbits with IAD or during pregnancy. CONCLUSIONS: The present study demonstrated the presence of ENaC in the rabbit LG and its alterations in IAD and pregnancy, suggesting that ENaC may contribute to the pathogenesis of altered LG secretion and ocular surface symptoms in these animals.

Loss of NHE8 expression impairs ocular surface function in mice.

Sodium/hydrogen exchanger (NHE) 8 is expressed at the apical membrane of the epithelial cells and plays important roles in neutral sodium absorption in the gastrointestinal tract and the kidney. It also has an important role in epithelial mucosal protection in the gastric gland and the intestine. Although NHE8 has broad tissue distribution, the precise location and the physiological role of NHE8 in the eye remain unknown. In the present study, we successfully detected the expression of NHE8 in the ocular surface by PCR and Western blot in human and mouse eyes. Immunohistochemistry staining located NHE8 protein at the plasma membrane of the epithelial cells in the conjunctiva, the cornea, and the lacrimal gland both in human and mouse. We also detected the expression of downregulated-in-adenoma (DRA, a Cl(-)/HCO3 (-) transporter) in the ocular surface epithelial cells. Using NHE8-/- mouse model, we found that loss of NHE8 function resulted in reduced tear production and increased corneal staining. These NHE8-/- mice also showed increased expression of TNF-α and matrix metalloproteinase 9 (MMP9) genes. The expression of epithelial keratinization marker genes, small proline-rich protein 2h (Sprr2h) and transglutaminase 1 (Tgm1), were also increased in NHE8-/- eyes. Furthermore, DRA expression in NHE8-/- mice was reduced in the conjunctiva, the cornea, and the lacrimal glands in association with a reduction in conjunctival mucosal pH. Altered ocular surface function and reduced epithelial DRA expression in NHE8-/- mice suggest that the role of NHE8 in ocular surface tissue involve in tear production and ocular epithelial protection. This study reveals a potential novel mechanism of dry eye condition involving abnormal NHE8 function.

MicroRNA-125b inhibits lens epithelial cell apoptosis by targeting p53 in age-related cataract.

MicroRNA-125b (miR-125b) has been implicated in a variety of diseases as either repressors or promoters, and plays crucial roles in many cellular processes such as cell differentiation, proliferation and apoptosis. Age-related cataract has become one of the most serious problems facing the aging population in the world. The purpose of this study was to investigate the role of miR-125b in the development of age-related cataract. We demonstrated that miR-125b was downregulated in both age-related cataract tissue and lens epithelial cell apoptosis induced by UV irradiation. We also identified the impact of miR-125b on apoptosis in a lens epithelial cell line. In vitro, miR-125b regulates human lens epithelial cell apoptosis at least in part by directly targeting p53. In addition,an inverse relationship between miR-125b and p53 expression was seen in age-related cataract tissue. In conclusion,this study suggests that miR-125b might be closely involved in the pathogenesis of cataract, and has the potential to be a diagnostic biomarker or even a therapeutic modality for cataract.

Mucin deficiency causes functional and structural changes of the ocular surface.

MUC5AC is the most abundant gel-forming mucin in the ocular system. However, the specific function is unknown. In the present study, a Muc5ac knockout (KO) mouse model was subject to various physiological measurements as compared to its wide-type (WT) control. Interestingly, when KO mice were compared to WT mice, the mean tear break up time (TBUT) values were significantly lower and corneal fluorescein staining scores were significantly higher. But the tear volume was not changed. Despite the lack of Muc5ac expression in the conjunctiva of KO mice, Muc5b expression was significantly increased in these mice. Corneal opacification, varying in location and severity, was found in a few KO mice but not in WT mice. The present results suggest a significant difference in the quality, but not the quantity, of tear fluid in the KO mice compared to WT mice. Dry eye disease is multifactorial and therefore further evaluation of the varying components of the tear film, lacrimal unit and corneal structure of these KO mice may help elucidate the role of mucins in dry eye disease. Because Muc5ac knockout mice have clinical features of dry eye, this mouse model will be extremely useful for further studies regarding the pathophysiology of the ocular surface in dry eye in humans.

Loss of Msx2 function down-regulates the FoxE3 expression and results in anterior segment dysgenesis resembling Peters anomaly.

Complex molecular interactions dictate the developmental steps that lead to a mature and functional cornea and lens. Peters anomaly is one subtype of anterior segment dysgenesis especially due to abnormal development of the cornea and lens. MSX2 was recently implicated as a potential gene that is critical for anterior segment development. However, the role of MSX2 within the complex mechanisms of eye development remains elusive. Our present study observed the morphologic changes in conventional Msx2 knockout (KO) mice and found phenotypes consistent with Peters anomaly and microphthalmia seen in humans. The role of Msx2 in cornea and lens development was further investigated using IHC, in situ hybridization, and quantification of proliferative and apoptotic lens cells. Loss of Msx2 down-regulated FoxE3 expression and up-regulated Prox1 and crystallin expression in the lens. The FoxE3 and Prox1 malfunction and precocious Prox1 and crystallin expression contribute to a disturbed lens cell cycle in lens vesicles and eventually to cornea-lentoid adhesions and microphthalmia in Msx2 KO mice. The observed changes in the expression of FoxE3 suggest that Msx2 is an important contributor in controlling transcription of target genes critical for early eye development. These results provide the first direct genetic evidence of the involvement of MSX2 in Peters anomaly and the distinct function of MSX2 in regulating the growth and development of lens vesicles.

Confocal microscopic evaluation of cornea after AquaLase liquefaction cataract extraction.

AIM: The most recent and innovative AquaLase liquefaction technology has offered an alternative to lens extraction. Many studies have investigated its functions and advantages. This article focuses on evaluating the in vivo microscopic cornea changes after AquaLase liquefaction by using a laser confocal microscope. METHODS: In this perspective, randomized case study, 37 eyes of 35 patients submitted to cataract surgery were chosen to undergo AquaLase liquefaction cataract extraction. Each patient was assessed before the operation, on the 1(st), 7(th), and 30(th) postoperative days, and 6 months after the cataract extraction. The morphologies and quantitative comparisons of corneal cells and corneal nerves layer by layer were evaluated in vivo with the Heidelberg Retina Tomograph III-Rostock Cornea Module (HRT-III RCM) confocal microscope. ANOVA and Post-Hoc Bonferroni test were carried out to compare the results pre- and post-operation. RESULTS: ANOVA results indicated no post-operation changes for epithelium and anterior stroma cells. Irregular segments of sub-basal nerve fiber were most pronounced seven days post-operation. In the mid and posterior stroma, keratocytes were obvious compared with the preoperative condition. Corneal endothelium cells became obviously swollen in cytoplasm and nucleus. The mid and posterior stroma cell density decreased from the 1(st) to 7(th) postoperative days (P<0.05). The corneal endothelium cell density decreased (P<0.05) and did not revert to the preoperative level after six months (P<0.05). CONCLUSION: Slight microstructural abnormalities were identified in the corneal recovery process after AquaLase liquefaction. AquaLase liquefaction cataract extraction is safe for cornea.

Myxofibrosarcoma of the orbit: an underrecognized entity? Case report and review of the literature.

PURPOSE: To describe the clinicopathologic and immunohistochemical features of a rare case of myxofibrosarcoma (MFS) involving the orbit. DESIGN: Retrospective interventional case report and review of literature. METHODS: The clinical history, systemic imaging studies, and histopathologic results of the orbital biopsy are reviewed. MAIN OUTCOME MEASURES: Clinical, radiologic, and histologic features of MFS. RESULTS: A 63-year-old Chinese male sought treatment for a history of rapidly progressive proptosis associated with decreased vision in the left eye over 10 days. Magnetic resonance imaging of the orbit revealed a homogenous mass extending to the optic canal. The mass was excised partially and was submitted for histologic and ultrastructural examination. Histologic testing revealed features of MFS with characteristic diffuse proliferation of atypical, spindle-shaped fibroblasts with prominent myxoid stroma. Tumor cells were reactive for vimentin. Ultrastructural examination revealed spindle-shaped tumor cells, rich in dilated rough endoplasmic reticulum and prominent vacuoles. CONCLUSIONS: For historical reasons, MFS involving the orbit is likely to be underrecognized and categorized erroneously as malignant fibrous histiocytoma or other soft tissue sarcoma. Although orbital MFS is an extremely rare diagnosis, ophthalmologists should be aware of the possibility and consider a diagnosis of MFS when an adult seeks treatment for an orbital tumor with aggressive growth.

Molecular and phylogenetic analyses of a new amphotropic murine leukemia virus (MuLV-1313).

BACKGROUND: The amphotropic murine leukemia viruses (MuLV-A's) are naturally occurring, exogenously acquired gammaretroviruses that are indigenous to the Southern California wild mice. These viruses replicate in a wide range of cell types including human cells in vitro and they can cause both hematological and neurological disorders in feral as well as in the inbred laboratory mice. Since MuLV-A's also exhibit discrete interference and neutralization properties, the envelope proteins of these viruses have been extremely useful for studying virus-host cell interactions and as vehicles for transfer of foreign genes into a variety of hosts including human cells. However, the genomic structure of any of the several known MuLV-A's has not been established and the evolutionary relationship of amphotropic retroviruses to the numerous exogenous or endogenous MuLV strains remains elusive. Herein we present a complete genetic structure of a novel amphotropic virus designated MuLV-1313 and demonstrate that this retrovirus together with other MuLV-A's belongs to a distinct molecular, biological and phylogenetic class among the MuLV strains isolated from a large number of the laboratory inbred or feral mice. RESULTS: The host range of MuLV-1313 is similar to the previously isolated MuLV-A's except that this virus replicates efficiently in mammalian as well as in chicken cells. Compared to ENV proteins of other MuLV-A's (4070A, 1504A and 10A-1), the gp70 protein of MuLV-1313 exhibits differences in its signal peptides and the proline-rich hinge regions. However, the MuLV-1313 envelope protein is totally unrelated to those present in a broad range of murine retroviruses that have been isolated from various inbred and feral mice globally. Genetic analysis of the entire MuLV-1313 genome by dot plot analyses, which compares each nucleotide of one genome with the corresponding nucleotide of another, revealed that the genome of this virus, with the exception of the env gene, is more closely related to the biologically distinct wild mouse ecotropic retrovirus (Cas-Br-E) isolated from another region of the Southern California, than to any of the 15 MuLV strains whose full-length sequences are present in the GenBank. This finding was corroborated by phylogenetic analyses and hierarchical clustering of the entire genomic sequence of MuLV-1313, which also placed all MULV-A's in a genetically distinct category among the large family of retroviruses isolated from numerous mouse strains globally. Likewise, construction of separate dendrograms for each of the Gag, Pol and Env proteins of MuLV-1313 demonstrated that the amphotropic retroviruses belong to a phylogenetically exclusive group of gammaretroviruses compared to all known MuLV strains. CONCLUSION: The molecular, biological and phylogenetic properties of amphotropic retroviruses including MuLV-1313 are distinct compared to a large family of exogenously- or endogenously-transmitted ecotropic, polytropic and xenotropic MuLV strains of the laboratory and feral mice. Further, both the naturally occurring amphotropic and a biologically discrete ecotropic retrovirus of the Southern California wild mice are more closely related to each other on the evolutionary tree than any other mammalian gammaretrovirus indicating a common origin of these viruses. This is the first report of a complete genomic analysis of a unique group of phylogenetically distinct amphotropic virus.