PEDF peptide plus hyaluronic acid stimulates cartilage regeneration in osteoarthritis via STAT3-mediated chondrogenesis

Aims

Pigment epithelium-derived factor (PEDF) is known to induce several types of tissue regeneration by activating tissue-specific stem cells. Here, we investigated the therapeutic potential of PEDF 29-mer peptide in the damaged articular cartilage (AC) in rat osteoarthritis (OA).

Methods

Mesenchymal stem/stromal cells (MSCs) were isolated from rat bone marrow (BM) and used to evaluate the impact of 29-mer on chondrogenic differentiation of BM-MSCs in culture. Knee OA was induced in rats by a single intra-articular injection of monosodium iodoacetate (MIA) in the right knees (set to day 0). The 29-mer dissolved in 5% hyaluronic acid (HA) was intra-articularly injected into right knees at day 8 and 12 after MIA injection. Subsequently, the therapeutic effect of the 29-mer/HA on OA was evaluated by the Osteoarthritis Research Society International (OARSI) histopathological scoring system and changes in hind paw weight distribution, respectively. The regeneration of chondrocytes in damaged AC was detected by dual-immunostaining of 5-bromo-2'-deoxyuridine (BrdU) and chondrogenic markers.

Results

The 29-mer promoted expansion and chondrogenic differentiation of BM-MSCs cultured in different defined media. MIA injection caused chondrocyte death throughout the AC, with cartilage degeneration thereafter. The 29-mer/HA treatment induced extensive chondrocyte regeneration in the damaged AC and suppressed MIA-induced synovitis, accompanied by the recovery of cartilage matrix. Pharmacological inhibitors of PEDF receptor (PEDFR) and signal transducer and activator of transcription 3 (STAT3) signalling substantially blocked the chondrogenic promoting activity of 29-mer on the cultured BM-MSCs and injured AC.

Conclusion

The 29-mer/HA formulation effectively induces chondrocyte regeneration and formation of cartilage matrix in the damaged AC.

Potential Benefits of Integrin αvβ3 Antagonists in a Mouse Model of Experimental Dry Eye

PURPOSE

The purpose of this study was to extensively evaluate the efficacy of integrin αvβ3 antagonists for the treatment of experimental dry eye (EDE).

METHODS

Vitronectin, an αvβ3 ligand, was used to induce tumor necrosis factor-α gene expression in human THP-1 macrophages. To induce EDE, C57BL/6 mice were housed in a low-humidity controlled environment chamber and injected subcutaneously with scopolamine for 7 days. Subsequently, αvβ3 antagonists, including RGDfD, c(RGDfD), c(RGDiD), c(RGDfK), ATN-161, SB273005, and cilengitide, were administered topically to EDE animals under controlled environment chamber conditions. Corneal epithelial damage in EDE was assessed by fluorescein staining. The density of conjunctival goblet cells and secretion of tears was measured by period acid-Schiff staining and phenol red-impregnated cotton threads, respectively. Inflammation markers, including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-17A, and metalloproteinase (MMP)-9, in the pooled cornea and conjunctiva tissues were examined by real-time polymerase chain reaction.

RESULTS

The inhibitory effects of αvβ3 antagonists on the vitronectin-induced tumor necrosis factor-α gene expression and integrin-mediated inflammatory signaling were validated in THP-1 macrophages. αvβ3 antagonists ameliorated the impairment of the corneal epithelial barrier with varying therapeutic efficacies, compared with vehicle-treated mice. c(RGDfD) and c(RGDiD) significantly protected against goblet cell loss, tear reduction, and proinflammatory gene expression in EDE.

CONCLUSIONS

Topical applications of αvβ3 antagonists yield therapeutic benefits in EDE by promoting corneal epithelial defect healing and reducing inflammation. Antagonistic targeting αvβ3 may be a novel promising strategy to treat patients with dry eye disease.

Short peptides derived from pigment epithelium-derived factor attenuate retinal ischemia reperfusion injury through inhibition of apoptosis and inflammatory response in rats

Pigment epithelium-derived factor (PEDF) is widely recognized as a neuroprotective factor expressed in the retina and has shown therapeutic potential in several retinal diseases. Our study aimed to identify the neuroprotective fragment in PEDF and investigate its protective activity in retinas under ischemia-reperfusion (IR) condition. We synthesized a series of shorter synthetic peptides, 6-mer (Ser93-Gln98) and its d-form variant (6 dS) derived from the 44-mer (Val78-Thr121; a PEDF neurotrophic fragment), to determine their cytoprotective activity in IR injury, which was induced in rat retinas by injection of saline into the anterior chamber to increase the intraocular pressure (IOP) followed by reperfusion. We found the cytoprotective effect of 6-mer on glutamate-treated Neuro-2a cells and tert-butyl hydroperoxide (tBHP)-treated 661W cells were 2.6-fold and 1.5-fold higher than the 44-mer, respectively. The cytoprotective effect was blocked by a chemical inhibitor atglistatin and blocking antibody targeting PEDF receptor (PEDF-R). IR induced several impairments in retina, including cell apoptosis, activation of microglia/macroglia, degeneration of retinal capillaries, reduction in electroretinography (ERG) amplitudes, and retinal atrophy. Such IR injuries were ameliorated by treatment with 6-mer and 6 dS eye drops. Also, the neuroprotective activity of 6-mer and 6 dS in ischemic retinas were dramatically reversed by atglistatin preconditioning. Taken together, our data demonstrate smallest neuroprotective fragment of PEDF has potential to treat retinal degeneration-related diseases.

The Therapeutic Effects of a PEDF-Derived Short Peptide on Murine Experimental Dry Eye Involves Suppression of MMP-9 and Inflammation

Purpose

To evaluate the efficacy of a pigment epithelium-derived factor (PEDF)-derived short peptide 29-mer, on the treatment and prevention of experimental dry eye (EDE).

Methods

C57BL/6 mice were housed in a low humidity controlled environment chamber for 14 days to induce EDE. The 29-mer was administered topically to their eyes, for treatment or dosing, from the point of housing in the controlled environment chamber. The efficacy of the 29-mer on EDE was evaluated in terms of corneal epithelial integrity, tear secretion, and the density of conjunctival goblet cells. PEDF and inflammatory factors, including tumor necrosis factor-α, IL-1β, IL-6, monocyte chemotactic protein (MCP)-1, matrix metalloproteinase-9, and macrophage infiltration, were examined by real-time polymerase chain reaction, Western blotting, and immunostaining. The involvement of the PEDF receptor/PNPLA2 on the 29-mer effects was evaluated by a specific inhibitor, atglistatin. Rabbit corneal epithelial cells were exposed to hyperosmotic medium to induce inflammatory responses.

Results

The levels of PEDF protein increased in the corneal epithelium of EDE, compared with the nonstressed mice. The 29-mer showed a therapeutic effect on EDE and prevented the development of EDE, accompanied by amelioration of the inflammatory factors. The 29-mer effects of inflammatory relief were dramatically reversed by atglistatin. The 29-mer also suppressed the expression of matrix metalloproteinase-9 and proinflammatory cytokines in rabbit corneal epithelial cells induced by hyperosmolarity.

Conclusions

Through this animal study, we provide a proof of concept of the anti-inflammatory domain of PEDF having potential to treat dry eye disease.

Translational Relevance

This study shows the 29-mer has novel potential as an ophthalmic drop treatment for dry eye disease.

A short peptide derived from pigment epithelial-derived factor exhibits an angioinhibitory effect

Background

Pigment epithelial-derived factor (PEDF), a 50 kDa secreted glycoprotein, exhibits distinct effects on a range of cell types. PEDF has been shown to inhibit vascular endothelial growth factor (VEGF)-mediated angiogenesis and widely accepted as a promising agent for treatment eye diseases related to neovascularization. A pool of short peptide fragments derived from PEDF reportedly manifests angioinhibitory activity. This study aims to determine the minimal PEDF fragment which can exert the anti-VEGF effect.

Methods

A series of shorter synthetic peptides, derived from the 34-mer (PEDF amino acid positions Asp44-Asn77), were synthesized. An MTT assay was used to evaluate the ability of the 34-mer-derived peptides to inhibit VEGF-induced proliferation of multiple myeloma RPMI8226 cells. Cell apoptosis was monitored by annexin V-FITC staining. Western blot analysis was used to detect phosphorylated kinases, including c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), and the expression of apoptosis-associated proteins, including p53, bax and caspase-3. VEGF-mediated angiogenesis of human umbilical vein endothelial cells (HUVECs), rat aortic ring and mouse cornea were used to detect the angioinhibitory activity of the PEDF-derived peptides.

Results

The MTT assay showed that the anti-VEGF effect of a 7-mer (Asp64-Ser70) was 1.5-fold greater than the 34-mer. In addition, massive apoptosis (37%) was induced by 7-mer treatment. The 7-mer induced JNK phosphorylation in RPMI8226 cells. Cell apoptosis and apoptosis-associated proteins induced by the 7-mer were blocked by pharmacological inhibition of JNK, but not p38 MAPK. Moreover, the 7-mer prevented VEGF-mediated angiogenesis of endothelial cells (ECs), including tube formation, aortic EC spreading and corneal neovascularization in mice.

Conclusions

This is the first study to show that the PEDF 7-mer peptide manifests anti-VEGF activity, further establishing its potential as an anti-angiogenic agent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02295-0.

Pigment Epithelium-Derived Factor Peptide Promotes Corneal Nerve Regeneration: An In Vivo and In Vitro Study

Purpose

To investigate the potential of a pigment epithelium-derived factor (PEDF) peptide 44-mer to promote nerve regeneration in a rabbit corneal nerve injury model to demonstrate its neurotrophic ability in cultivated mouse trigeminal neuron cells.

Methods

Subconjunctival or intrastromal injection of 44-mer on the cornea was performed in a rabbit model of corneal nerve injury created by corneal epithelial debridement. Immunocytochemical analysis (44-mer, anti-tubulin III, SMI312, CD11b, and α-SMA) and in vivo confocal microscopy were performed. Corneal sensation was estimated using a Cochet-Bonnet corneal esthesiometer. Primary cultivated mouse trigeminal neurons were used to examine the in vitro neurotrophic ability of 44-mer. The cellular morphology and the immunocytochemical staining with anti-tubulin III and SMI312 in different concentrations of 44-mer were compared, and a quantitative assessment of neurite outgrowth was performed.

Results

Immunohistochemical staining showed the retention of 44-mer in the corneal stroma for at least 7 days after a single dose of corneal intrastromal injection and promoted corneal nerve regeneration revealed by in vivo confocal microscopy. Corneal esthesiometer demonstrated gradual recovery of the corneal sensation in 44-mer-treated eyes with a lower corneal touch threshold than wounded vehicles and closer to baseline at 3 weeks after corneal injury (P < 0.001). In vitro studies showed a dose-dependent neurotrophic effect of 44-mer in cultivated trigeminal neuron cells.

Conclusions

The 44-mer showed in vivo and in vitro corneal neurotrophic abilities. Our results suggest that intrastromal injection of 44-mer into the corneal stroma may have a potential role in treating diseases related to corneal nerve damage.

Ophthalmologic manifestations in Taiwanese patients with mucopolysaccharidoses

Background

Mucopolysaccharidoses (MPSs) are a group of rare lysosomal storage disorders characterized by the accumulation of glycosaminoglycans in various tissues and organs. Ocular problems that affect the cornea, trabecular meshwork, sclera, retina, and optic nerve are very common in these patients. However, there was limited literature focusing on comprehensive ocular findings in different types of MPS.

Methods

We retrospectively reviewed the clinical ophthalmologic features and electrodiagnostic results of 50 Taiwanese patients with a diagnosis of MPS (34 males and 16 females; age range, 1.1–34.9 years; nine with MPS I, 17 with MPS II, 17 with MPS IV, and seven with MPS VI).

Results

Among 44 patients with available data for visual acuity, 15 patients (34%) had a visual acuity of less than 0.5 (6/12) equivalent in their better eye, including 71% of those with MPS VI, 38% with MPS IV, 29% with MPS I, and 14% with MPS II. Severe corneal opacities existed in 57% of MPS VI patients and 11% of MPS I patients, compared with none for MPS II and MPS IV patients. Among 80 eyes with available data of refraction, 11 eyes (14%) had myopia (≦−0.50 D), 55 eyes (69%) had hyperopia (≧0.50 D), and 55 eyes (69%) had high astigmatism (≧1.50 D). Ocular hypertension was found in 45% (28/62) of eyes. There were 16% (14/90), 11% (10/90), 13% (12/90), 31% (27/86), and 79% (30/38) of MPS eyes with lens opacities, optic disc swelling, optic disc cupped, retinopathy, and visual pathway dysfunction, respectively. Intraocular pressure was positively correlated with the severity of corneal opacity (p < 0.01).

Conclusions

Ocular complications with significant reduction in visual acuity are common in MPS patients. Diagnostic problems may arise in these patients with severe corneal opacification, especially for those with MPS VI and MPS I.

PEDF-derived peptide promotes tendon regeneration through its mitogenic effect on tendon stem/progenitor cells

Background

Tendon stem/progenitor cells (TSPC) exhibit a low proliferative response to heal tendon injury, leading to limited regeneration outcomes. Exogenous growth factors that activate TSPC proliferation have emerged as a promising approach for treatment. Here, we evaluated the pigment epithelial-derived factor (PEDF)-derived short peptide (PSP; 29-mer) for treating acute tendon injury and to determine the timing and anatomical features of CD146- and necleostemin-positive TSPC in the tendon healing process.

Methods

Tendon cells were isolated from rabbit Achilles tendons, stimulated by the 29-mer and analyzed for colony-forming capacity. The expression of the TSPC markers CD146, Oct4, and nestin, induced by the 29-mer, was examined by immunostaining and western blotting. Tendo-Achilles injury was induced in rats by full-thickness insertion of an 18-G needle and immediately treated topically with an alginate gel, loaded with 29-mer. The distribution of TSPC in the injured tendon and their proliferation were monitored using immunohistochemistry with antibodies to CD146 and nucleostemin and by BrdU labeling.

Results

TSPC markers were enriched among the primary tendon cells when stimulated by the 29-mer. The 29-mer also induced the clonogenicity of CD146⁺ TSPC, implying TSPC stemness was retained during TSPC expansion in culture. Correspondingly, the expanded TSPC differentiated readily into tenocyte-like cells after removal of the 29-mer from culture. 29-mer/alginate gel treatment caused extensive expansion of CD146⁺ TSPC in their niche on postoperative day 2, followed by infiltration of CD146⁺/BrdU⁻ TSPC into the injured tendon on day 7. The nucleostemin⁺ TSPC were located predominantly in the healing region of the injured tendon in the later phase (day 7) and exhibited proliferative capacity. By 3 weeks, 29-mer-treated tendons showed more organized collagen fiber regeneration and higher tensile strength than control tendons. In culture, the mitogenic effect of the 29-mer was found to be mediated by the phosphorylation of ERK2 and STAT3 in nucleostemin⁺ TSPC.

Conclusions

The anatomical analysis of TSPC populations in the wound healing process supports the hypothesis that substantial expansion of resident TSPC by exogenous growth factor is beneficial for tendon healing. The study suggests that synthetic 29-mer peptide may be an innovative therapy for acute tendon rupture.

Pigment Epithelial-Derived Factor Peptide Regenerated Limbus Serves as Regeneration Source for Limbal Regeneration in Rabbit Limbal Deficiency

PURPOSE

To demonstrate that a 44-amino acid peptide from pigment epithelial-derived factor (PEDF) induces the regeneration of limbal excision wound, and the regenerated limbus can act as the regeneration source for new limbal excisional injuries in rabbit model of limbal deficiency.

METHODS

Half circumference partial limbal excision was followed by PEDF peptide treatment to achieve limbal wound regeneration. Three months later, a second stage half circumference partial limbal excision removed the remaining native limbal tissue followed by PEDF peptide treatment. The structure and function of the regenerated limbus were analyzed at 3 and 6 months. Conjunctivalization was analyzed by impression cytology. Immunohistochemical analysis was performed with antibodies to corneal epithelium-associated keratin 3 (K3), conjunctival epithelium-associated keratin 13 (K13), ΔNp63α, ABCG2, and BrdU. Extensive limbal excision was performed to examine the regeneration potential of the PEDF peptide.

RESULTS

Total limbal stem cell deficiency occurred with severe inflammation and conjunctivalization of the limbal wound and adjacent cornea in vehicle control eyes. In PEDF peptide treated eyes, the regenerated limbus prevented fibrovascular invasion and goblet cell migration into the corneal surface. Immunohistochemical staining of the regenerated limbus showed a wide distribution of cells expressing ΔNp63α and ABCG2 as in the native limbus. BrdU labeling assay revealed the presence of slow-cycling cells in the basal layer of the regenerated limbus. The PEDF peptide can heal extensive limbal excisional wounds and sustain ocular surface integrity.

CONCLUSIONS

The addition of PEDF peptide has the potential to repair limbal excisional wounds with the recovery of normal limbus-like anatomy and function. The PEDF peptide is a potential remedy for extensive limbal injury.

Intramuscular hemangioma causing periosteal reaction and cortical hypertrophy misdiagnosed as osteoid osteoma

•

We report a case of intramuscular hemangioma mimicking osteoid osteoma.

•

Magnetic resonance image (MRI) is the most precise diagnostic tool for the identification of soft-tissue mass adjacent to the bone.

•

Precise preoperative diagnosis is essential to avoid excessive surgery.

Introduction

Intramuscular hemangioma in the periosteal region is rare. Although comprising less than 1% of all hemangiomas, they represent the most common type of intramuscular tumors. When located adjacent to bone, a periosteal reaction can occur. The deep localization of the hemangioma poses the diagnosis difficult. Only 8% to 19% of cases were diagnosed before surgery according to the literature review.

Presentation of case

We present a case of forty-one-year-old female diagnosed with intramuscular hemangioma, mimicking osteoid osteoma, adjacent to the periosteal region of tibia diaphysis treated by surgical excision.

Discussion

When intramuscular hemangioma occurs nearby a bone structure, it can cause cortical, medullary and periosteal bone changes that are frequently misdiagnosed by plain radiography. Due to their infrequency, deep location, and atypical presentation, these lesions are seldom diagnosed at presentation. The hemangioma of the periosteal region can be locally destructive due to compression exerted on neighboring structures. It does not regress spontaneously, and surgical excision is frequently needed.

Conclusion

Intramuscular hemangioma of periosteal region occurs most commonly adjacent to long bones of the lower limb. They can cause hypertrophic periosteal reactions mimicking a periosteal or parosteal tumor. Although osteoid osteoma was considered in the differential diagnosis, MRI with enhancement should be performed to exclude intramuscular hemangioma. This may avoid unnecessary aggressive en-bloc tumor excisions resulting in bone weakness and prolonged rehabilitation.

This case report has been written in line with the SCARE criteria (Agha et al., 2016 [1]).

Development of a millimetrically scaled biodiesel transesterification device that relies on droplet-based co-axial fluidics

In this study, we investigated a fluidic system that adheres to new concepts of energy production. To improve efficiency, cost, and ease of manufacture, a millimetrically scaled device that employs a droplet-based co-axial fluidic system was devised to complete alkali-catalyzed transesterification for biodiesel production. The large surface-to-volume ratio of the droplet-based system, and the internal circulation induced inside the moving droplets, significantly enhanced the reaction rate of immiscible liquids used here – soybean oil and methanol. This device also decreased the molar ratio between methanol and oil to near the stoichiometric coefficients of a balanced chemical equation, which enhanced the total biodiesel volume produced, and decreased the costs of purification and recovery of excess methanol. In this work, the droplet-based co-axial fluidic system performed better than other methods of continuous-flow production. We achieved an efficiency that is much greater than that of reported systems. This study demonstrated the high potential of droplet-based fluidic chips for energy production. The small energy consumption and low cost of the highly purified biodiesel transesterification system described conforms to the requirements of distributed energy (inexpensive production on a moderate scale) in the world.

Pigment Epithelial-Derived Factor Peptide Facilitates the Regeneration of a Functional Limbus in Rabbit Partial Limbal Deficiency

PURPOSE

To investigate the potential of a pigment epithelial-derived factor (PEDF) peptide 44-mer to promote limbal regeneration in a rabbit partial limbal deficiency model.

METHODS

Limbal excision (180°) was created surgically, and topical application of 44-mer-containing ointment once a day for 2 weeks was started immediately after injury. Limbal barrier function was inspected at 2 and 6 months after treatment. Corneal neovascularization was observed under slit-lamp microscope. The presence of goblet cells on the corneal surface was examined using impression cytology. The resulting repair tissue was assessed by immunohistochemical staining with antibodies for putative limbal stem cell (LSC) markers ΔNp63α and ABCG2. Cells harvested from the regenerated tissue were analyzed for colony-forming capacity and expression of LSC markers by immunostaining assay and quantitative real-time PCR (qPCR).

RESULTS

Eyes treated with the 44-mer blocked vascularization and goblet cell migration onto the corneal surface. By means of immunohistochemical staining and cell isolation in the repair tissue, we showed that LSCs were widely distributed at the regenerated tissue after 44-mer treatment. The repaired limbus contributed robustly to corneal wound healing as effectively as undamaged limbus.

CONCLUSIONS

We demonstrated that 44-mer regenerates a functional limbus-like structure on limbal excision wounds. Our finding suggests that the PEDF peptide derivative may be an innovative strategy for tissue engineering and repair therapy in partial LSC deficiency diseases.

Distribution of corneal and ocular spherical aberrations in eyes with cataract in the Taiwanese population

Purpose:

To investigate the distribution of corneal and ocular spherical aberrations (SAs) in eyes with cataract in the Taiwanese population.

Methods:

Corneal and ocular SAs were measured in the central 6-mm optical zone using wavefront aberrometry. Axial length (AL) and keratometry (K) were also evaluated in each eye.

Results:

A total of 413 eyes in 234 patients were analyzed. The mean age of the patients was 66.8 ± 10.64 years. The mean AL and K values were 24.32 mm and 44.08 D, respectively. The mean corneal SA was 0.307 ± 0.135 μm and ocular SA was −0.042 ± 0.487 μm. Ocular and corneal SAs were significantly correlated (r² = 0.04, p < 0.001). Corneal and ocular SAs were not significantly correlated with K (p = 0.096 and p = 0.634, respectively), but were significantly correlated with AL (p < 0.001). Multilinear regression showed that corneal SAs and age were the dependent variables that predicted ocular SAs (r² = 0.143, F = 13.65, p < 0.01), especially in patients who were aged > 50 years, for whom a strongly significant positive correlation was found (r² = 0.102, F = 11.10, p < 0.001).

Conclusion:

Corneal and ocular SAs varied among cataract patients and correlated with AL. After 50 years of age, ocular SAs increased significantly because of an increase in internal (lenticular) SAs. Corneal SAs in Taiwanese patients were larger than those in Japanese patients and similar to those in Chinese and Malaysian populations. Preoperative measurement of wavefront aberrations is necessary to select which aspherical intraocular lenses are most suitable for achieving better postoperative visual quality.

Characteristics of peripapillary choroidal cavitation detected by optical coherence tomography

PURPOSE

To evaluate the clinical features of peripapillary choroidal cavitation (PCC) detected by optical coherence tomography (OCT).

DESIGN

Retrospective, observational case series.

PARTICIPANTS

One hundred twenty-two eyes from 83 patients diagnosed with PCC by OCT database review were included in this study.

METHODS

Stereoscopic color fundus photographs from eyes with PCC were reviewed by 2 independent ophthalmologists. They were masked to the refractive error, axial length, and OCT findings.

MAIN OUTCOME MEASURES

Chart review and data analysis included gender, age, best-corrected visual acuity (BCVA), refractive error, axial length, clinical appearance of the peripapillary area, and associated funduscopic abnormalities.

RESULTS

One hundred twenty-two eyes with PCC from 83 patients were analyzed. Among the patients, 41.8% were men and 58.2% were women. The mean age was 48.2 ± 12.6 years and mean BCVA in logarithm of the minimum angle of resolution units was 0.23 ± 0.43. The mean refractive error in spherical equivalent was -9.03 ± 5.11 diopters (D) and mean axial length (AL) was 27.36 ± 2.09 mm. With respect to refractive error, 90 eyes (73.8%) were highly myopic (≥-6.00 D), 24 eyes (19.7%) had low myopia (<-6.00 D), 5 eyes (4.1%) were emmetropic (1.00 to -1.00 D), and 3 eyes (2.6%) were hyperopic (>1.00 D). Forty eyes (32.8%) with PCC had AL of less than 26.50 mm (mean, 25.11 ± 1.07 mm; range, 22.51-26.42 mm). Patients with eyes with PCC that had low myopia, were emmetropic, and were hyperopic also were significantly older than patients with highly myopic eyes (P<0.05). Stereoscopic fundus photographs demonstrated a yellow-orange, localized, well-circumscribed peripapillary lesion in 57 (46.7%) eyes with PCC. A PCC with opening was observed in 14 (26.4%) of 53 eyes with excavated myopic conus and in 5 (7.2%) of 69 eyes without excavated myopic conus (P<0.05).

CONCLUSIONS

This study demonstrated that peripapillary choroidal cavitation is common and not exclusive to highly myopic eyes. The funduscopic finding of a yellow-orange peripapillary abnormality may not be evident in all eyes with demonstrable PCC by OCT. Although its pathogenesis and pathologic significance require further investigation, PCC may be a degenerative change in aging eyes.

Eclipse photodynamic therapy for a presumed peripapillary metastatic tumor

PURPOSE

We report a successful use of a modified photodynamic therapy (PDT) termed Eclipse PDT in treating a patient with peripapillary metastatic choroidal tumor.

METHODS

Optic disk protection effect was measured with different colored paper disk attached to the reflecting mirror of the laser machine.

RESULTS

Black paper disk was chosen to perform Eclipse PDT because of its maximal blocking effect. A patient with peripapillary metastatic choroidal tumor was treated using this method, and the postoperative outcome was favorable, with improvement in visual acuity and resolution of subretinal fluid.

CONCLUSION

With the new technique, treatment can be modified according to the lesion's shape and location without damaging the optic disk. Eclipse PDT can further extend the indication of PDT treatment to peripapillary choroidal neovascularization as well as choroidal tumors close to the optic disk.

MMP-7 knock-in corneal fibroblast cell lines secrete MMP-7 with proteolytic activity towards collagen XVIII

PURPOSE

To determine whether matrix metalloproteinase-7 (MMP-7) that is stably overexpressed by mouse corneal fibroblast cell lines exhibits proteolytic activity against the NC1 fragment of collagen XVIII.

METHODS

Corneal fibroblasts isolated from MMP-7 knockout (7ko) mice were subjected to SV40 T-antigen immortalization and stably transfected with a bicistronic retroviral vector encoding green fluorescence protein and active MMP-7. The resulting MMP-7 knock-in fibroblasts (7ko-MMP-7 cells) were isolated and enriched by fluorescence activated cell sorting (FACS). Culture media samples from 7ko and 7ko-MMP-7 cells were then incubated with the recombinant NC1 fragment of collagen XVIII, and NC1 degradation was monitored by immunoblotting.

RESULTS

Immunoblot analysis revealed that MMP-7 was present in lysates and culture media from 7ko-MMP-7 fibroblasts, but not media from immortalized 7ko fibroblasts. Importantly, lower amounts of the NC1 fragment were present in in vitro enzymatic reaction mixtures containing concentrated 7ko-MMP-7 media than in those containing concentrated 7ko media.

CONCLUSION

Immortalized fibroblasts stably transfected with MMP-7 secrete active MMP-7 with proteolytic activity towards the NC1 fragment of collagen XVIII.

Vitrectomy without internal limiting membrane peeling for macular retinoschisis and foveal detachment in highly myopic eyes

PURPOSE

To report the surgical outcome of pars plana vitrectomy (PPV) without internal limiting membrane (ILM) peeling in three highly myopic patients with macular retinoschisis and associated posterior staphyloma.

METHODS

We report three highly myopic patients with macular retinoschisis and foveal detachment who underwent simple PPV without ILM peeling, with long-acting gas tamponade. Main outcome evaluations included best corrected visual acuity, biomicroscopic appearance and optical coherence tomography findings.

RESULTS

Pars plana vitrectomy without ILM peeling resulted in anatomic and functional improvement in all three operated eyes for follow-up periods of > or = 12 months.

CONCLUSIONS

Pars plana vitrectomy without ILM peeling is effective for treating macular retinoschisis and foveal detachment in highly myopic eyes with posterior staphyloma. Visual and anatomic outcomes are comparable with those in previous studies in which ILM removal was performed.

Subconjunctival injection of recombinant AAV-angiostatin ameliorates alkali burn induced corneal angiogenesis

PURPOSE

To evaluate the effect of subconjunctival injection of recombinant adeno-associated virus (rAAV)-angiostatin in alkali burn-induced corneal angiogenesis.

METHODS

Adeno-associated viral vector-mediated gene delivery into extraocular tissue was determined by fluorescent microscopy three weeks after subconjunctival injection of viral vector expressing green fluorescent protein (rAAV-GFP). Subconjunctival injection of recombinant adeno-associated viral vector expressing human angiostatin (rAAV-angiostatin) and blank rAAV viral vector (control) was performed in the left eye of male Sprague-Dawley rats (n=6). Alkaline induction of corneal neovascularization (NV) was performed three weeks later. Corneal NV regression was analyzed 7-14 days after alkali burn with slit lamp and digital pictures. Transgenic expression of angiostatin in the cornea, conjunctiva, retina, and muscle insertions was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Transgenic GFP gene expression was detected mainly in the muscle fibers at the extraocular muscle (EOM) insertions after subconjunctival injection. The area of corneal neovascularization was significantly lower in eyes injected with rAAV-angiostatin (p<0.01) than in eyes injected with the control virus. RT-PCR demonstrated that the angiostatin gene expression was highly detectable in muscle fibers and not detectable in the conjunctiva, cornea, and retina.

CONCLUSIONS

Subconjunctival injection of rAAV-angiostatin reduced alkali burn-induced corneal angiogenesis. We proved the concept that ocular gene therapy by subconjunctival injection of adenovirus-associated gene transfer of angiogenesis inhibitors can be a simple and safe treatment modality that can achieve therapeutic levels and long lasting effects in the treatment of corneal NV induced by ocular surface disorders.

The future of wavefront sensing and customization

The possibility of achieving supernormal vision in terms of acuity and contrast has fueled the imagination and creativity of vision researchers to pursue the goal of customized wavefront refractive surgery. This goal is achieved by generating an optimal ablation pattern based on individual anatomical and functional characteristics of the treated eye. However, increasing concerns regarding the clinical applicability of customized wavefront correction have emerged, and the possibility of achieving supernormal vision in all patients has been challenged. It is by understanding current optical, physiologic,and technological challenges faced by treating physicians and basic researchers that we can develop clear objectives for the future development of customized refractive surgery.

Gait analysis in advanced Parkinson's disease--effect of levodopa and tolcapone

OBJECTIVE

To determine the therapeutic effect of levodopa/benserazide and tolcapone on gait in patients with advanced Parkinson's disease.

METHODS

Instrumental gait analysis was performed in 38 out of 40 patients with wearing-off phenomenon during a randomized, double-blind, placebo-controlled trial of tolcapone.

RESULTS

Gait analysis disclosed a significant improvement by levodopa/benserazide in walking speed, stride length and the range of motion of hip, knee and ankle joints. At the end of the study, both the UPDRS motor scores during off-period and the percentage of off time improved significantly using tolcapone. However, gait analysis could not confirm this improvement. With respect to levodopa/benserazide effect, the reduction in rigidity correlated with improved angular excursion of the ankle, whereas the decreased bradykinesia correlated with improved stride length and angular excursion of the hip and knee joints.

CONCLUSION

The results of our gait analysis confirmed that in parkinsonian patients with fluctuating motor symptoms levodopa/benserazide, but not tolcapone, produced a substantial improvement.

Detection of oligoclonal bands in patients with neurologic diseases: comparison between agarose gel-, immunofixation- and isoelectric-focusing electrophoresis

BACKGROUND

The presence of oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) often implies the involvement of the humoral immune response in the disease process. We compared three methods of electrophoresis to determine the frequency and pattern of OCBs in Chinese patients with various neurologic diseases.

METHODS

CSF samples and matched serum samples were collected from 122 patients. OCBs were examined in all the CSF samples after agarose gel electrophoresis (AGE) or isoelectric-focusing electrophoresis (IEF); some samples were selected and concentrated for immunofixation electrophoresis (IFE).

RESULTS

While 46.7% of the CSF samples showed elevated immunoglobulins using AGE, OCBs were unequivocally identified in 16.4% of samples. In contrast, the detection rate of OCBs using IEF was 54.1%, while that of monoclonal bands was 4.9%. Some OCBs could be detected by IFE, which demonstrated that most of them were IgG-kappa. Using IEF, the sensitivity was 66.7% in multiple sclerosis, 47.8% in myelopathy, 88.9% in chronic inflammatory demyelinating polyradiculoneuropathy, 62.5% in acute inflammatory demyelinating polyradiculoneuropathy, 80.0% in meningoencephalitis and 23.0% in other neurologic diseases.

CONCLUSIONS

IEF was the most sensitive method for detecting OCBs. Most patients with type 2 or type 3 patterns of OCBs had multiple sclerosis or meningoencephalitis, although some of these patients may present with a type 4 pattern. Most patients with other diseases had identical patterns of OCBs in both serum and CSF.

Genetic screening for Huntington's disease in Chinese patients with involuntary movements

The diagnosis of Huntington's disease (HD) can be confirmed by detecting the expanded CAG repeat in the IT15 gene. Besides chorea, patients with HD may present with a variety of bizarre involuntary movements, resulting in confusion in making the diagnosis. Under such conditions, genetic analysis is the final confirmatory test. To determine if any patient with involuntary movements of undetermined etiology might be related to HD, we did genetic analysis on 22 patients and identified three with expanded CAG repeat. We could not obtain family history of HD in these patients due to adoption, early death of parents, or a vague history. All three patients were among the group with generalized chorea, but one had additional marked dystonic posturing. Together with four clinically recognizable HD patients, the relative frequency of HD among the 103 patients with choreiform movements in this hospital is 6.8%.

An add-on study of selegiline to Madopar in the treatment of parkinsonian patients with dose-related fluctuations: comparison between Jumexal and Parkryl

BACKGROUND

To improve dose-related fluctuations in patients with Parkinson's disease, the efficacy of selegiline, a selective inhibitor of monoamine oxidase B, was determined.

METHODS

Twenty parkinsonian patients were selected for a short-term, single-blind, cross-over trial. Each patient received one of the two brands of selegiline, Parkryl (Mei-Shih), 10 mg per day as an adjunct to Madopar. After a 6-week treatment period and a 4-week wash-out period, the treatment was switched to the other brand of selegiline, Jumexal (Labatec), for another 6 weeks.

RESULTS

Five patients dropped out of the study because of the development of intolerable dyskinesia, hallucination or agitation. The 15 patients that completed the study made a mild improvement in the total motor scores of the on-period during both treatments of Parkryl (p < 0.01) and of Jumexal (p < 0.05). The recorded daily off-time decreased from 37.8% to 20.7% in the Parkryl group (p < 0.01), and to 21.0% in the Jumexal group (p < 0.01).

CONCLUSION

Selegiline, as an adjunct therapy to Madopar, has a moderate effect in prolonging the duration of on-time in parkinsonian patients with dose-related fluctuations. Jumexal seemed to produce no greater effect than Parkryl.

Experience of pergolide in the treatment of Chinese parkinsonian patients with dose-related fluctuations

BACKGROUND

To improve dose-related fluctuations in patients with Parkinson's disease, the efficacy of pergolide, a long-acting dopamine receptor agonist, was determined.

METHODS

Using a stringent diagnostic criterion for Parkinson's disease, 20 patients were selected for a short-term open-label trial, and were divided into three groups based on the accuracy of clinical diagnosis.

RESULTS

Nineteen patients completed the study. The mean dosage of pergolide was 2.89 mg per day. The total motor score improved by 34.1% during the "on" period and by 34.8% during the "off" period (p < 0.001). The recorded daily off time decreased from 40.3% to 11.5% (p < 0.001). There was no statistically significant difference in the magnitude of response among different groups of patients; however, patients with shorter duration of illness also received significantly lower dosage of pergolide. Hallucination, worsening of peak-dose dyskinesia, and lowering of blood pressure were major adverse effects. Pergolide could not prevent the occurrence of neuroleptic malignant syndrome in one patient.

CONCLUSIONS

Pergolide is very effective for moderate to advanced Parkinson's disease.

Absence of 4,977-bp deletion of blood cell mitochondrial DNA in patients with young-onset Parkinson's disease

Decreased mitochondrial Complex I activities and a 4,977-bp deletion in mitochondrial DNA (mtDNA) have been reported in patients with Parkinson's disease. Based on the assumption of possible links between this 4,977-bp deletion and the etiology of Parkinson's disease, we analyzed mtDNA of blood cells from 15 patients with young-onset Parkinson's disease after the DNA was amplified by polymerase chain reaction. We could not detect the 4,977-bp mtDNA deletion in any of these patients. This result suggests that Parkinson's disease is not a mitochondrial disease due to the 4,977-bp mtDNA deletion. The 4,977-bp deletion in mtDNA appears to be an age-related phenomenon.