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Purpose: Leptospirosis is a waterborne zoonotic disease that primarily causes systemic illness, followed by uveitis. After heavy flooding in Madurai district, an epidemic outbreak of systemic and ocular leptospirosis occurred in 1994. Our data shows a transition to endemicity after each epidemic. Aim: The aim of this study is to report the clinical signs, epidemic outbreaks, and persistent endemicity of leptospiral uveitis, as well as the diagnostic dilemmas associated with it. Methods: A retrospective analysis of clinical signs was conducted using medical records of leptospiral uveitis patients over a period of 27 years (1994–2020) in a tertiary care eye hospital. The clinical workup of uveitis included a detailed clinical history, systemic, and ophthalmic examination. Microagglutination tests (MATs) was done at the Centers for Disease Control and Prevention (CDC) in Atlanta and later in our regional laboratory. Serum samples were collected from human systemic leptospirosis cases and a small group of animals in and around Madurai. Results: The first epidemic outbreak resulted in 200 seropositive patients. Subsequent epidemic outbreaks occurred in 1997, 1998, 2001, 2005, and 2012, with Madurai experiencing multiple outbreaks. However, the disease remained endemic, with 25–50 patients being observed per year in between the peaks. Ocular examination revealed acute non-granulomatous uveitis (94.9%), pan uveitis (59.8%), vitreous inflammatory reaction (55.4%), retinal vasculitis (29.5%), disc hyperemia (20.9%), and hypopyon. (16.2%). New serovars emerged every year, resulting in decreased sensitivity of the MAT. Over time, the MAT started to miss diagnoses. Conclusion: The persistent endemicity of leptospiral uveitis emphasizes the need for accessible diagnostic tests. The low performance of the MAT can be attributable to the use of an older panel. The incorporation of new isolates in the MAT by a national laboratory will improve the accuracy of diagnosis.

The anterior lens epithelium has the ability to differentiate into lens fibres throughout its life. The present study aims to identify and functionally characterize the adult stem cells in the human lens epithelium. Whole mounts of lens epithelium from donor eyes (normal/cataract) were immunostained for SOX2, gap junction protein alpha 1 (GJA1), PAX6, α, β and γ-crystallins, followed by a confocal analysis. The functional property of adult stem cells was analysed by their sphere forming ability using cultured lens epithelial cells from different zones. Based on marker expression, the lens epithelium was divided into four zones: the central zone, characterized by a small population of PAX6+, GJA1−, β-crystallin− and γ-crystallin− cells; the germinative zone, characterized by PAX6+, GJA1+, β-crystallin− and γ-crystallin−; the transitional zone, characterized by PAX6+, GJA1+, β-crystallin+ and γ-crystallin−; and the equatorial zone, characterized by PAX6+/−, GJA1+, β-crystallin+, and γ-crystallin+ cells. The putative lens epithelial stem cells identified as SOX2+ and GJA1 membrane expression negative cells were located only in the central zone (1.89 ± 0.84%). Compared to the other zones, a significant percentage of spheres were identified in the central zone (1.68 ± 1.04%), consistent with the location of the putative adult lens epithelial stem cells. In the cataractous lens, an absence of SOX2 expression and a significant reduction in sphere forming ability (0.33 ± 0.11%) were observed in the central zone. The above findings confirmed the presence of putative stem cells in the central zone of the adult human lens epithelium and indicated their probable association with cataract development.

Abstract The purpose of the present study was to assess the differential intraocular pressure response (IOP) to dexamethasone (DEX) treatment at two dose levels (100 or 500 nM) in perfusion cultured Indian cadaveric eyes to investigate glucocorticoid (GC) responsiveness. In a human organ-cultured anterior segment (HOCAS) set-up, the eye pressure was monitored for every 24 h post DEX infusion (100 or 500 nM) or 0.1% ethanol treatment for 7 days after baseline stabilization. The expression of DEX-inducible proteins such as myocilin and fibronectin in HOCAS-TM tissues was assessed by immunostaining. Elevated IOP was observed in 6/16 eyes [Mean ± SEM (mΔIOP): 15.50 ± 1.96 mmHg; 37.5% responders] and 3/15 eyes (Mean ± SEM mΔIOP: 10 ± 0.84 mmHg; 20% responders) in 100 nM and 500 nM dose groups respectively. Elevated IOP in GC responder eyes was substantiated with a significant increase in myocilin (11.8-fold; p = 0.0002) and fibronectin (eightfold; p = 0.04) expression as compared to vehicle-treated eyes by immunofluorescence analysis. This is the first study reporting the GC responsiveness in Indian cadaveric eyes. The observed GC response rate was comparable with the previous studies and hence, this model will enable us to investigate the relationship between differential gene expression and individual GC responsiveness in our population.

To elucidate the microarchitecture of limbus and cornea in subjects with Vogt Koyanagi Haradas syndrome (VKH) From January 2019 to December 2019 a total of 17 VKH subjects, 5 acute and 12 chronic, 18 non VKH uveitis controls, and 6 healthy controls were recruited for this study. In vivo confocal microscopic (IVCM) analysis of the limbal basal epithelium, scleral side of the limbus, limbal niche, corneal keratocytes, and corneal nerves was carried out. Absence of pigmented cells in the limbal basal epithelium, presence of inflammatory cells on the scleral side of the limbus, fibrotic niche, degenerated keratocytes, thinning, and beading of corneal nerves were noted in VKH eyes as compared to controls. Presence of inflammatory cells and depigmentation of limbus in chronic VHK points to disease progression.Keratocyte and corneal nerve changes in Vogt Koyanagi Haradas syndrom are novel findings. [ABSTRACT FROM AUTHOR]

Over the years, there has been a growing need for producing cost effective, porous scaffold biomaterials for tissue engineering. Therefore, this study focused on fabrication of β-chitosan based scaffold from the waste of the pen of locally available squid variety Loligo duvauceli (Indian Squid). The scaffold was prepared by the solvent casting method which requires less time and minimum energy. To the best of our knowledge,there are no reports on scaffold preparation from the extracted β-chitosan. The biological properties of extracted chitosan scaffolds C(L) were evaluated and compared with those of commercial chitosan scaffold C(S). The prepared scaffolds were characterized by SEM, swelling property, in vitro enzymatic degradation, and hemo, biocompatibility properties. C(L) scaffolds had an average pore size of 60 µm and the swelling ratio was 16.2 ± 2.2% with mass loss percentage of 20.8 ± 4.5% after 4 weeks of degradation. It has exhibited good hemocompatible properties and thermal stability. Mouse fibroblast 3T3 cells were able to adhere and proliferate well in the extracted β-chitosan C(L) scaffold. All these results indicated that extracted β-chitosan C(L) is a suitable alternative for biomaterials used for tissue engineering purposes. [ABSTRACT FROM AUTHOR]

Purpose Till date there is no exclusive marker for human corneal epithelial stem cells (CESCs). In this study, our strategy is to combine high expression of ABCG2, a putative SC marker with high N/C ratio to develop a specific method for identification of CESCs. Methods Limbal/corneal epithelial cells ( LECs/ CECs) were isolated from cadaver eyes by enzymatic treatment and the cytospin smears/cryosections were immunostained for ABCG2, p63, or connexin-43 ( Cx-43) and counterstained with propidium iodide/ DAPI. Analysis was carried out for (1) ABCG2 expression, N/C ratio, (2) p63, ABCG2, N/C ratio, and (3) ABCG2, Cx-43, N/C ratio using confocal/fluorescence microscopy. Results ABCG2 was highly expressed by cells in the basal and suprabasal layers of limbus. The SCs identified on the basis of our earlier method using high levels of p63 expression along with high (>0.7) N/C ratio were strongly positive for ABCG2 and negative for differentiation marker Cx-43. High expression of ABCG2 was also observed in cells with high p63 expression and low (<0.7) N/C ratio; however, they were positive for Cx-43. Combining high ABCG2 expression with large N/C ratio in fluorescence microscopy identified 5.3 ± 3.5% LECs as putative SCs and this was confirmed by confocal microscopic analysis. Conclusions We demonstrate the importance of combining ABCG2 expression with N/C ratio for identification and quantification of human CESCs. This method will have application in evaluating the role of niche cells/factors in the maintenance of stemness. Microsc. Res. Tech. 76:242-248, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]