Ocular involvement in Steven-Johnson syndrome/toxic epidermal necrolysis: recent insights into pathophysiology, biomarkers, and therapeutic strategies.

Purpose Of Review: To review the pathophysiology, recent biomarkers related to the ocular aspects of Steven-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), and to highlight notable evidence published in recent years.

Recent Findings: Several studies reveal the relationship between tear cytokines and the pathological components in eyes of SJS/TEN patients. Specific clinical features and associated risk factors in the acute stage have shown significant correlations with chronic ocular sequelae.

Impact of gender mismatch on corneal graft rejection and rejection-related graft failure in repeat penetrating keratoplasty.

Purpose: To explore the impact of gender mismatch on corneal allograft rejection and rejection-related graft failure in patients with repeat penetrating keratoplasty (PK).

Methods: A retrospective cohort was conducted at Ramathibodi Hospital, Bangkok, Thailand. Patients with repeat PK and follow-up period of at least 6 months were recruited.

Evaluating Dry Eye and Meibomian Gland Dysfunction With Meibography in Patients With Stevens-Johnson Syndrome.

Purpose: To investigate ocular surface and meibomian gland characteristics using infrared meibography in patients with Stevens-Johnson syndrome (SJS).

Methods: This is a single-center, prospective, noncontrolled, observational study. Thirty-two Thai patients (64 eyes) with SJS for 1 year or longer (1-44 years) were enrolled in the study.

3,4-Dihydroxyphenylacetate 2,3-dioxygenase from Pseudomonas aeruginosa: An Fe(II)-containing enzyme with fast turnover.

3,4-dihydroxyphenylacetate (DHPA) dioxygenase (DHPAO) from Pseudomonas aeruginosa (PaDHPAO) was overexpressed in Escherichia coli and purified to homogeneity. As the enzyme lost activity over time, a protocol to reactivate and conserve PaDHPAO activity has been developed. Addition of Fe(II), DTT and ascorbic acid or ROS scavenging enzymes (catalase or superoxide dismutase) was required to preserve enzyme stability.

The transfer of reduced flavin mononucleotide from LuxG oxidoreductase to luciferase occurs via free diffusion.

Bacterial luciferase (LuxAB) is a two-component flavin mononucleotide (FMN)-dependent monooxygenase that catalyzes the oxidation of reduced FMN (FMNH(-)) and a long-chain aliphatic aldehyde by molecular oxygen to generate oxidized FMN, the corresponding aliphatic carboxylic acid, and concomitant emission of light. The LuxAB reaction requires a flavin reductase to generate FMNH(-) to serve as a luciferin in its reaction. However, FMNH(-) is unstable and can react with oxygen to generate H2O2, so that it is important to transfer it efficiently to LuxAB.

Reduction kinetics of a flavin oxidoreductase LuxG from Photobacterium leiognathi (TH1): half-sites reactivity.

Bacterial bioluminescence is a phenomenon resulting from the reaction of a two-component FMN-dependent aldehyde monooxygenase system, which comprises a bacterial luciferase and a flavin reductase. Bacterial luciferase (LuxAB) is one of the most extensively investigated two-component monooxygenases, while its reductase partner, the flavin reductase (LuxG) from the same operon, has only been recently expressed in a functional form. This work reports transient kinetics identification of intermediates in the LuxG reaction using stopped-flow spectrophotometry.

LuxG is a functioning flavin reductase for bacterial luminescence.

The luxG gene is part of the lux operon of marine luminous bacteria. luxG has been proposed to be a flavin reductase that supplies reduced flavin mononucleotide (FMN) for bacterial luminescence. However, this role has never been established because the gene product has not been successfully expressed and characterized.

Luciferase from Vibrio campbellii is more thermostable and binds reduced FMN better than its homologues.

A new luciferase from V. campbellii (Lux_Vc) was cloned and expressed in Escherichia coli and purified to homogeneity. Although the amino acid sequences and the catalytic reactions of Lux_Vc are highly similar to those of the luciferase from V.