Developmentally regulated mitochondrial biogenesis and cell death competence in maize pollen.

BACKGROUND: Cytoplasmic male sterility (CMS) is a maternally inherited failure to produce functional pollen that most commonly results from expression of novel, chimeric mitochondrial genes. In Zea mays, cytoplasmic male sterility type S (CMS-S) is characterized by the collapse of immature, bi-cellular pollen. Molecular and cellular features of developing CMS-S and normal (N) cytoplasm pollen were compared to determine the role of mitochondria in these differing developmental fates. RESULTS: Terminal deoxynucleotidyl transferase dUTP nick end labeling revealed both chromatin and nuclear fragmentation in the collapsed CMS-S pollen, demonstrating a programmed cell death (PCD) event sharing morphological features with mitochondria-signaled apoptosis in animals. Maize plants expressing mitochondria-targeted green fluorescent protein (GFP) demonstrated dynamic changes in mitochondrial morphology and association with actin filaments through the course of N-cytoplasm pollen development, whereas mitochondrial targeting of GFP was lost and actin filaments were disorganized in developing CMS-S pollen. Immunoblotting revealed significant developmental regulation of mitochondrial biogenesis in both CMS-S and N mito-types. Nuclear and mitochondrial genome encoded components of the cytochrome respiratory pathway and ATP synthase were of low abundance at the microspore stage, but microspores accumulated abundant nuclear-encoded alternative oxidase (AOX). Cytochrome pathway and ATP synthase components accumulated whereas AOX levels declined during the maturation of N bi-cellular pollen. Increased abundance of cytochrome pathway components and declining AOX also characterized collapsed CMS-S pollen. The accumulation and robust RNA editing of mitochondrial transcripts implicated translational or post-translational control for the developmentally regulated accumulation of mitochondria-encoded proteins in both mito-types. CONCLUSIONS: CMS-S pollen collapse is a PCD event coincident with developmentally programmed mitochondrial events including the accumulation of mitochondrial respiratory proteins and declining protection against mitochondrial generation of reactive oxygen species.

T Helper 2 IL-4/IL-13 Dual Blockade with Dupilumab Is Linked to Some Emergent T Helper 17‒Type Diseases, Including Seronegative Arthritis and Enthesitis/Enthesopathy, but Not to Humoral Autoimmune Diseases.

Dupilumab, an IL-4/IL-13 receptor blocker, has been linked to emergent seronegative inflammatory arthritis and psoriasis that form part of the spondyloarthropathy spectrum. We systematically investigated patterns of immune disorders, including predominantly T helper 17‒(spondyloarthropathy pattern) and T helper 2‒mediated disorders and humoral autoimmune pattern diseases, using VigiBase, the World Health Organization's global pharmacovigilance of adverse drug reactions. Several bioinformatics databases and repositories were mined to couple dupilumab-related immunopharmacovigilance with molecular cascades relevant to reported findings. A total of 37,848 dupilumab adverse drug reaction cases were reported, with skin, eye, and musculoskeletal systems most affected. Seronegative arthritis (OR = 9.61), psoriasis (OR = 1.48), enthesitis/enthesopathy (OR = 12.65), and iridocyclitis (OR = 3.77) were highly associated. However, ankylosing spondylitis and inflammatory bowel disease were not conclusively associated. Overall, classic polygenic humoral‒mediated autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus were not associated with dupilumab use. Pathway analysis identified several biological pathways potentially involved in dupilumab‒associated adverse drug reactions, including the fibroblast GF receptor (in particular, FGFR2) pathway. MicroRNAs analysis revealed the potential involvement of hsa-miR-21-5p and hsa-miR-335-5p. In conclusion, IL-4/IL-13 blockers are not unexpectedly protective against humoral autoimmune diseases but dynamically skew immune responses toward some IL-23/IL-17 cytokine pathway‒related diseases. IL-4/13 axis also plays a role in homeostatic tissue repair and we noted evidence for a link with ocular and arterial pathology.

Systemic corticosteroid use in UK Uveitis practice: results from the ocular inflammation steroid toxicity risk (OSTRICH) study.

OBJECTIVES: To ascertain adherence to an international consensus target of ≤7.5 mg/day of prednisolone for maintenance systemic corticosteroid (CS) prescribing in uveitis and report the frequency of courses of high-dose systemic CS in the UK. METHODS: We conducted a national, multicentre audit of systemic CS prescribing for uveitis at 11 UK sites between November 2018 and March 2019. High-dose CS was defined as (1) maintenance >7.5 mg prednisolone for >3 consecutive months, or (2) >1 course ≥40 mg oral CS or ≥500 mg intravenous (IV) methylprednisolone in the past 12 months. Case notes of patients exceeding threshold CS doses were reviewed by an independent uveitis specialist and judged as avoidable or not, based upon a scoring matrix. RESULTS: Of 667 eligible patients, 285 (42.7%) were treated with oral or IV CS over the preceding 12 months; 96 (33.7%) of these exceeded the threshold for high-dose CS. Twenty-five percent of prescribing in patients on excess CS was judged avoidable; attributed to either prescribing long-term CS without evidence of consideration of alternative strategies, prescribing error or miscommunication. More patients received immunomodulatory therapy (IMT) in the group treated with CS above threshold than below threshold (p < 0.001) but there was no significant difference in doses of IMT. CONCLUSION: 33% of patients had been prescribed excessive corticosteroid when compared to the reference standard. An analysis of decision-making suggests there may be opportunity to reduce excess CS prescribing in 25% of these patients.

Unilateral acute maculopathy associated with adult onset hand, foot and mouth disease: case report and review of literature.

BACKGROUND: Acute maculopathy is a rare condition of unknown aetiology and Coxsackie virus is known to be associated with this macular chorioretinitis. FINDINGS: We report a case of acute unilateral maculopathy in a 35-year-old woman with concurrent hand foot and mouth disease. Furthermore, we display multimodal imaging (colour fundus photographs, autofluorescence, spectral domain ocular coherence tomography, fluorescein angiography and indocyanine green angiography) charting the course of the disease. The source of the virus was thought to be the patient's child. Empirical treatment with oral corticosteroids was commenced and the inflammation resolved, leaving a residual macular scar. CONCLUSIONS: We present this case combined with the review of literature of adult onset Coxsackie-virus-associated retinitis. This case reiterates the fact that Coxsackie virus is an uncommon but important consideration in the differential diagnosis of chorioretinitis and posterior uveitis with atypical retinopathy.

Repeatability of ocular blood flow pneumotonometry.

PURPOSE: To establish the repeatability of ocular blood flow (OBF) pneumotonometry and its agreement with Goldmann tonometry. DESIGN: Instrument evaluation study. PARTICIPANTS: Ten female healthcare professionals. METHODS: Intraocular pressure (IOP) was measured by one experienced ophthalmologist in both eyes of 10 healthy female subjects on 10 different occasions at the same time of day. The two methods were performed by alternate allocation, and laterality was chosen by random order. Repeatability coefficients and agreement plots were calculated by using the Bland-Altman method. MAIN OUTCOME MEASURES: Intraocular pressure repeatability coefficients. RESULTS: Mean IOPs were 15.6 mmHg (right) and 15.1 mmHg (left) by OBF pneumotonometry and 12.6 mmHg (right) and 12.4 mmHg (left) by Goldmann tonometry (P < 0.001). The repeatability coefficients were 7.06 (right) and 7.66 (left) for the OBF pneumotonometer and 4.81 (right) and 3.87 (left) for the Goldmann tonometer. With regard to agreement, the OBF pneumotonometer read significantly higher than did the Goldmann tonometer. The mean bias for the right eye was 2.92 (95% limits of agreement, -4.37 to 10.20), and for the left eye it was 2.68 (95% limits of agreement, -3.93 to 9.28). CONCLUSIONS: In our group of healthy females, the repeatability of the OBF pneumotonometer was worse than that of the Goldmann tonometer. This casts doubt on the value of the OBF pneumotonometer as a tool for measuring IOP. The agreement plots indicate that the OBF pneumotonometer may produce significant numbers of false-positive results in screening programs.