Bilateral Pseudomonas aeruginosa Keratitis in 7 Patients.

PURPOSE: To report 7 patients (14 eyes) with bilateral Pseudomonas aeruginosa keratitis (PAK). METHODS: Case records of patients with bilateral PAK were reviewed at a single academic medical center from April 2009 to December 2020. RESULTS: Seven patients aged 29 to 94 years presented with bilateral P. aeruginosa corneal ulcers. All patients were soft contact lens wearers except one elderly patient with a complex ocular history. Three patients wore specialty contact lens, including one cosmetic contact lens wearer, one multifocal contact lens wearer, and one extended-wear contact lens wearer. The remaining three patients were not overnight contact lens wearer but regularly showered in contact lens or used tap water for contact lens case cleaning. All patients presented with asymmetric disease, with visual acuity ranging from 20/20 to light perception. Ulcers were located centrally in 5 eyes (35.7%), diffusely over the entire cornea in 5 eyes (35.7%), temporally in 2 eyes (14.2%), and nasally in 1 eye (7.14%), and in 1 eye (8.3%), the ulcer location was not recorded. Corneal thinning was noted in 7 eyes (50%). Hypopyon was also noted in 7 eyes (50%). Two patients required procedures because of progressive stromal necrosis. All other patients were treated nonsurgically, with antibiotic drops, which resulted in ulcer resolution. Final visual acuity on last recorded follow-up ranged from 20/20 to no light perception. CONCLUSIONS: This is the largest case series of bilateral PAK, which occurred primarily in contact lens wearer. This case series reiterates the risk of contact lens infection related to poor hygiene.

Comparison of Clinical Features and Treatment Outcomes of Pseudomonas aeruginosa Keratitis in Contact Lens and Non-Contact Lens Wearers.

PURPOSE: To compare the outcomes of Pseudomonas aeruginosa keratitis (PAK) in contact lens wearers (CLWs) and non-contact lens wearers (non-CLWs) and identify risk factors for poor visual acuity (VA) outcomes in each group. DESIGN: Retrospective cohort study METHODS: Two hundred fourteen consecutive cases of PAK were included between January 2006 and December 2019. Clinical features, microbiologic results, and treatment course were compared between CLW and non-CLW groups. Analyses of clinical features predicting poor final VA were performed. RESULTS: This study identified 214 infected eyes in 207 patients with PAK, including 163 eyes (76.2%) in CLWs and 51 eyes (23.8%) in non-CLWs. The average age was 39.2 years in CLWs and 71.9 years in non-CLWs (P < .0001). The average logMAR visual acuity (VA) at presentation was 1.39 in CLWs and 2.17 in non-CLWs (P < .0001); average final VA was 0.76 in CLWs and 1.82 in non-CLWs (P < .0001). Stromal necrosis required a procedural or surgical intervention in 13.5% of CLWs and 49.0% of non-CLWs (P < .0001). A machine learning-based analysis yielded a list of clinical features that most strongly predict a poor VA outcome (worse than 20/40), including worse initial VA, older age, larger size of infiltrate or epithelial defect at presentation, and greater maximal depth of stromal necrosis. CONCLUSIONS: Non-CLWs have significantly worse VA outcomes and required a higher rate of surgical intervention, compared with CLWs. Our study elucidates risk factors for poor visual outcomes in non-CLWs with PAK.

A Required Ophthalmology Rotation: Providing Medical Students with a Foundation in Eye-Related Diagnoses and Management.

Introduction: Current ophthalmologic training in medical school is inadequate in preparing medical students to handle basic eye complaints as nonophthalmology residents. Most medical students are uncomfortable performing eye examinations, but increased ophthalmology training improves confidence in this area. The University of Pittsburgh School of Medicine (UPSOM) teaches students the basics of ophthalmology with a required 1-week rotation during the 1-month specialty care clerkship (SCC), providing students with skills to perform rudimentary eye examinations as nonophthalmology providers. Methods: Within a 1-week ophthalmology rotation, we developed a series of interactive case-based teaching sessions, handouts, and homework that accompanied clinical instruction to familiarize third- and fourth-year medical students with ophthalmic equipment, terminology, diagnosis, and management. Of learners, 67 (roughly 11 per cohort) rotated on six consecutive SCCs beginning in May 2019. All learners completed an in-house exam and received resident clinical evaluations at the end of their rotation. Results: Of the 64 participants who responded to the survey, 100% rated the quality of teaching sessions outstanding or good, and 83% of students strongly agreed or agreed with the statement, "I believe the overall teaching in the ophthalmology clinical settings was good quality." The average clinical and exam score for ophthalmology over 6 months was 4.5 out of 5, and 83% respectively. Discussion: Generally positive student feedback as well as high clinical and exam scores suggested that the required UPSOM ophthalmology clerkship was both engaging and effective. This course can be easily adapted to teach students at other medical institutions.

The Ophthalmology Mini-Elective Gives Vision to Preclinical Medical Students.

Introduction: Ophthalmology education during medical school is often very limited. To provide exposure to areas beyond its standard curriculum, the University of Pittsburgh School of Medicine offers mini-elective courses in various disciplines. We developed such a course to provide instruction in the basics of clinical ophthalmology to interested preclinical medical students. Methods: First- and second-year medical students electively enrolled in our course (mean number of students per year = 12), which included four sessions combining didactics and hands-on learning. Additionally, each student individually spent time with an ophthalmologist in the operating room. Our course was held each year from 2015 to 2019. Results: Participants completed pre- (n = 25) and postsurveys (n = 20), reflecting increased comfort with the ophthalmologic history and physical examination. In 2019, participants also completed pre- and posttests, demonstrating increased knowledge of ophthalmology. Discussion: The Ophthalmology Mini-Elective is a unique educational tool that introduces the principles of ophthalmology to preclinical medical students, addressing an area of medicine that is generally minimally included in the required curriculum.

FANCA safeguards interphase and mitosis during hematopoiesis in vivo.

The Fanconi anemia (FA/BRCA) signaling network controls multiple genome-housekeeping checkpoints, from interphase DNA repair to mitosis. The in vivo role of abnormal cell division in FA remains unknown. Here, we quantified the origins of genomic instability in FA patients and mice in vivo and ex vivo. We found that both mitotic errors and interphase DNA damage significantly contribute to genomic instability during FA-deficient hematopoiesis and in nonhematopoietic human and murine FA primary cells. Super-resolution microscopy coupled with functional assays revealed that FANCA shuttles to the pericentriolar material to regulate spindle assembly at mitotic entry. Loss of FA signaling rendered cells hypersensitive to spindle chemotherapeutics and allowed escape from the chemotherapy-induced spindle assembly checkpoint. In support of these findings, direct comparison of DNA crosslinking and anti-mitotic chemotherapeutics in primary FANCA-/- cells revealed genomic instability originating through divergent cell cycle checkpoint aberrations. Our data indicate that FA/BRCA signaling functions as an in vivo gatekeeper of genomic integrity throughout interphase and mitosis, which may have implications for future targeted therapies in FA and FA-deficient cancers.

Fanconi anemia signaling network regulates the spindle assembly checkpoint.

Fanconi anemia (FA) is a heterogenous genetic disease with a high risk of cancer. The FA proteins are essential for interphase DNA damage repair; however, it is incompletely understood why FA-deficient cells also develop gross aneuploidy, leading to cancer. Here, we systematically evaluated the role of the FA proteins in chromosome segregation through functional RNAi screens and analysis of primary cells from patients with FA. We found that FA signaling is essential for the spindle assembly checkpoint and is therefore required for high-fidelity chromosome segregation and prevention of aneuploidy. Furthermore, we discovered that FA proteins differentially localize to key structures of the mitotic apparatus in a cell cycle-dependent manner. The essential role of the FA pathway in mitosis offers a mechanistic explanation for the aneuploidy and malignant transformation known to occur after disruption of FA signaling. Collectively, our findings provide insight into the genetically unstable cancers resulting from inactivation of the FA/BRCA pathway.

The tumor suppressor CDKN3 controls mitosis.

Mitosis is controlled by a network of kinases and phosphatases. We screened a library of small interfering RNAs against a genome-wide set of phosphatases to comprehensively evaluate the role of human phosphatases in mitosis. We found four candidate spindle checkpoint phosphatases, including the tumor suppressor CDKN3. We show that CDKN3 is essential for normal mitosis and G1/S transition. We demonstrate that subcellular localization of CDKN3 changes throughout the cell cycle. We show that CDKN3 dephosphorylates threonine-161 of CDC2 during mitotic exit and we visualize CDC2(pThr-161) at kinetochores and centrosomes in early mitosis. We performed a phosphokinome-wide mass spectrometry screen to find effectors of the CDKN3-CDC2 signaling axis. We found that one of the identified downstream phosphotargets, CKß phosphorylated at serine 209, localizes to mitotic centrosomes and controls the spindle checkpoint. Finally, we show that CDKN3 protein is down-regulated in brain tumors. Our findings indicate that CDKN3 controls mitosis through the CDC2 signaling axis. These results have implications for targeted anticancer therapeutics.