Ocular Sarcoidosis Masquerading as Acute Retinal Necrosis: Two Case Reports.

PURPOSE: To report two cases of ocular sarcoidosis (OS) initially presenting as unilateral acute retinitis, which mimicked acute retinal necrosis. METHODS: Retrospective descriptive case reports. RESULTS: Two middle-aged healthy Asian women experienced progressive vision loss in their left eyes over a one-month period. Anterior uveitis, vitritis, and diffuse peripheral retinal infiltration were observed. Comprehensive diagnostic evaluations were conducted, including blood work-up, viral polymerase chain reaction of anterior chamber paracentesis samples, and chest X-ray, all yielding negative results. Despite prompt initiation of antiviral therapy, retinal infiltrations remained unchanged within the first 10 days. Chest CT imaging revealed multiple lymphadenopathies consistent with sarcoidosis. Case 1 was presumed OS, and case 2 was definite OS based on lung and lymph node biopsy results in accordance with the 2017 revised international workshop on OS (IWOS) criteria. In both cases, the retinal lesions gradually resolved after several weeks of systemic corticosteroids, and the best corrected vision of the affected eye improved to 20/25 at the 12 and 6-month follow-ups, respectively. CONCLUSION: Acute unilateral retinal infiltration in the peripheral region, exhibiting rapid progression resembling acute retinal necrosis, can be a rare manifestation of OS. Chest CT imaging can provide valuable assistance in the diagnostic process, especially when systemic examinations yield no significant findings.

Taiwan ocular inflammation society consensus recommendations for the management of juvenile idiopathic arthritis-associated uveitis.

We presented the development of a consensus guideline for managing juvenile idiopathic arthritis-associated uveitis (JIAU) in Taiwan, considering regional differences in manifestation and epidemiology. The Taiwan Ocular Inflammation Society (TOIS) committee formulated this guideline using a modified Delphi approach with two panel meetings. Recommendations were based on a comprehensive evidence-based literature review and expert clinical experiences, and were graded according to the Oxford Centre for Evidence-Based Medicine's "Levels of Evidence" guideline (March 2009). The TOIS consensus guideline consists of 10 recommendations in four categories: screening and diagnosis, treatment, complications, and monitoring, covering a total of 27 items. These recommendations received over 75% agreement from the panelists. Early diagnosis and a coordinated referral system between ophthalmologists and pediatric rheumatologists are crucial to prevent irreversible visual impairment in children with JIAU. However, achieving a balance between disease activity and medication use remains a key challenge in JIAU management, necessitating further clinical studies.

Heterogeneous Nuclear Ribonucleoprotein H1 Coordinates with Phytochrome and the U1 snRNP Complex to Regulate Alternative Splicing in Physcomitrella patens.

Plant photoreceptors tightly regulate gene expression to control photomorphogenic responses. Although gene expression is modulated by photoreceptors at various levels, the regulatory mechanism at the pre-mRNA splicing step remains unclear. Alternative splicing, a widespread mechanism in eukaryotes that generates two or more mRNAs from the same pre-mRNA, is largely controlled by splicing regulators, which recruit spliceosomal components to initiate pre-mRNA splicing. The red/far-red light photoreceptor phytochrome participates in light-mediated splicing regulation, but the detailed mechanism remains unclear. Here, using protein-protein interaction analysis, we demonstrate that in the moss Physcomitrella patens, phytochrome4 physically interacts with the splicing regulator heterogeneous nuclear ribonucleoprotein H1 (PphnRNP-H1) in the nucleus, a process dependent on red light. We show that PphnRNP-H1 is involved in red light-mediated phototropic responses in P. patens and that it binds with higher affinity to the splicing factor pre-mRNA-processing factor39-1 (PpPRP39-1) in the presence of red light-activated phytochromes. Furthermore, PpPRP39-1 associates with the core component of U1 small nuclear RNP in P. patens Genome-wide analyses demonstrated the involvement of both PphnRNP-H1 and PpPRP39-1 in light-mediated splicing regulation. Our results suggest that phytochromes target the early step of spliceosome assembly via a cascade of protein-protein interactions to control pre-mRNA splicing and photomorphogenic responses.

Electrostatic interaction of phytochromobilin synthase and ferredoxin for biosynthesis of phytochrome chromophore.

In plants, phytochromobilin synthase (HY2) synthesize the open chain tetrapyrrole chromophore for light-sensing phytochromes. It catalyzes the double bond reduction of a heme-derived tetrapyrrole intermediate biliverdin IXalpha (BV) at the A-ring diene system. HY2 is a member of ferredoxin-dependent bilin reductases (FDBRs), which require ferredoxins (Fds) as the electron donors for double bond reductions. In this study, we investigated the interaction mechanism of FDBRs and Fds by using HY2 and Fd from Arabidopsis thaliana as model proteins. We found that one of the six Arabidopsis Fds, AtFd2, was the preferred electron donor for HY2. HY2 and AtFd2 formed a heterodimeric complex that was stabilized by chemical cross-linking. Surface-charged residues on HY2 and AtFd2 were important in the protein-protein interaction as well as BV reduction activity of HY2. These surface residues are close to the iron-sulfur center of Fd and the HY2 active site, implying that the interaction promotes direct electron transfer from the Fd to HY2-bound BV. In addition, the C12 propionate group of BV is important for HY2-catalyzed BV reduction. A possible role for this functional group is to mediate the electron transfer by interacting directly with AtFd2. Together, our biochemical data suggest a docking mechanism for HY2:BV and AtFd2.

Development of an enzyme-linked immunosorbent assay for detecting infectious bursal disease virus (IBDV) infection based on the VP3 structural protein.

Infectious bursal disease virus (IBDV) causes a contagious immunosuppressive disease in chickens. The aim of the present study is to develop an enzyme-linked immunosorbent assay (ELISA) using the expressed VP2 or VP3 protein of IBDV as the coating antigen for detecting antibodies to IBDV. Experimental results were compared with virus neutralization assay and a commercial-available ELISA. These assays were used to examine the sera from farm chickens and chickens vaccinated experimentally. The VP3-based ELISA had a higher correlation coefficient (R2) of 0.812 with a commercial ELISA kit at a serum dilution of 1:500 than that of VP2-based ELISA (R2) of 0.671. The relative sensitivity between virus neutralization and VP2-ELISA and VP3-ELISA was 96% (251/262) and 100% (262/262), respectively, and that between virus neutralization and a commercial ELISA was 99% (257/261). Additionally, compared with virus neutralization assay, the reference technique for diagnosing IBDV, VP3-based ELISA had an agreement value of 99%, superior to that of VP2-based ELISA (95%) or the commercial kit (89%). These results revealed that the capability of either VP2-ELISA or VP3-ELISA in detecting the field chicken sera was comparable to the commercial one, which is generally used to replace the virus neutralization assay. However, the preparation of VP3 is derived from an Escherichia coli expression system with a high yield and purification efficiency by Ni2+-NTA gels, which is more favorable to the insect cell-derived particles formed by VP2. Therefore, VP3-ELISA could be developed as an efficient and low cost diagnostic method for IBDV infection in field chickens.

The flunitrazepam abuse prevention program at a general hospital in Taiwan: a descriptive study.

The Bureau of Controlled Drugs at Ministry of Health, Executive Yuan in Taiwan announced, on 1 April 2000, the schedules of controlled drugs with abuse potential and implemented a policy on 1 October 2000 to control them. Flunitrazepam (FM2), along with other two benzodiazepines (triazolam and brotizolam), is placed on Schedule III. The aim of the present study was to analyze the pattern of flunitrazepam prescriptions across all medical subspecialty departments at Taipei Medical University-Wan Fang Hospital (TMU-WFH), Taiwan. We analyzed 1170 prescriptions over 12 month period from 1 July 2000 to 31 May 2001. All prescription data were divided into three 4 month periods: period I was when the flunitrazepam prescription was not controlled, period II represented the time when flunitrazepam was placed on Schedule III and when physicians were required to use a special duplicated prescription form and period III was when the TMU-WFH started to set a stricter control for the prescription of flunitrazepam. The results indicated that the number of flunitrazepam prescriptions during period III had decreased significantly compared with period I (P < or = 0.05). Eventually, 45.7% of flunitrazepam-medicated patients were followed up monthly with a restriction of their flunitrazepam supply to no more than 14 days, 22.9% of patients were followed up fortnightly at clinics with a 14 day supply of flunitrazepam, 15.7% were followed up fortnightly with a 14 day restriction of flunitrazepam plus a non-flunitrazepan benzodiazepine supplement, 10.7% were referred to clinics within the Department of Psychiatry and 5% were switched from flunitrazepam to other drugs.