Geographic Representation of Authorship in Ophthalmic Research from Low- and Middle-Income Countries.

PURPOSE: Low- and middle-income countries (LMICs) are underrepresented in ophthalmic research, despite carrying the highest burden of visual impairment. To assess the representation of local authors in global ophthalmic research, this cross-sectional, bibliometric analysis measured the proportion of LMIC-affiliated authorship in LMIC-based ophthalmic research. METHODS: We sampled original, primary research conducted in LMICs and published in 1 of 7 high-impact ophthalmic journals between 2017 and 2021. For each article, we extracted the number and name of country study site(s), country affiliation(s) of first and last author, proportion of LMIC-affiliated authors, funding sources, and study design. RESULTS: Of the 1,333 studies exclusively conducted in LMICs, 89.4% of first authors and 80.6% of last authors were exclusively LMIC-affiliated. Representation of LMIC-affiliated first authors were lower in studies based in low-income countries (25.0%) or in sub-Saharan Africa (26.5%), published in journals with higher impact factors (68.0% in Ophthalmology), funded by high-income countries (HICs) (41.4%), or conducted in both LMICs and HICs (27.1%). The United States, United Kingdom, and Australia had the 3rd, 6th, and 8th largest shares of last authors. There were only 12 single-country studies conducted in low-income countries, namely Ethiopia, the Gambia, Guinea, Liberia, the Niger, and Sierra Leone. Of these countries, only three held first authorship and one held last authorship. CONCLUSIONS: Although LMIC-based ophthalmic research has demonstrated higher local authorship representation compared to other fields, underrepresentation can be exacerbated by country income level, journal "prestige," and degree of HIC involvement. These discrepancies highlight the need for more equitable data ownership in global ophthalmic research.

Unilateral Roth spots as an initial presentation in Essential Thrombocythemia.

PURPOSE: To describe a 25-year-old female patient with unilateral Roth spots as the initial presentation of Essential Thrombocythemia. METHOD: Case report. RESULTS: A 25 -year-old female presented with visual complaints of seeing flashing lights and mild blurred vision in her left eye. Dilated fundus exam revealed intra-retinal hemorrhages with a pattern compatible with Roth spots. Further work up showed thrombocythemia with positive JAK2 (V617F) mutation, confirming the diagnosis of Essential Thrombocythemia (ET). The symptoms and fundus findings resolved in one month after initiation of the treatment with low dose oral aspirin.ET which is defined as repeated platelet count of ≥ 450,000 per microliter without a secondary cause, can present with highly variable symptoms from being asymptomatic to chest pain, cerebral venous sinus thrombosis, retinal vascular occlusion, and granuloma annulare.In the presented case Roth spots hastened the need for more complete workup to determine the systemic cause of this ocular finding, ultimately leading to the diagnosis. CONCLUSION: Finding of Roth spots may warrant a systemic work up to find out the underlying pathologic condition, which in the present case was Essential Thrombocythemia, a potentially life-threatening condition. DECLARATION: Authors declare no conflict of interest.

Diabetic retinopathy in African-Americans with end-stage kidney disease: a cross-sectional study on prevalence and impact on quality of life.

INTRODUCTION: The prevalence, severity, and quality of life (QoL) impact of diabetic retinopathy (DR) among African-Americans (AAs) with end-stage kidney disease (ESKD) undergoing dialysis are unknown. RESEARCH DESIGN AND METHODS: A cross-sectional study was conducted on 93 AA adults with diabetes and ESKD. The diagnosis of DR was based on a review of medical records and/or a positive photograph with a portable hand-held device reviewed by both artificial intelligence software and a retinal specialist. QoL, physical disability social determinants of health (SDoHs) were assessed by standardized questionnaires. RESULTS: The prevalence of DR was 75%, with 33% of participants having mild, 9.6% moderate and 57.4% severe DR. A total of 43% had normal visual acuity; 45% had moderate visual impairment; and 12% had severe visual impairment. We found a high burden of disease, multiple SDoH challenges, and low QoL and general health among patients with ESKD. The presence of DR had no significant impact on physical health and QoL compared with participants without DR. CONCLUSIONS: DR is present in 75% of AA patients with diabetes and ESKD on haemodialysis. ESKD has a significant burden on general health and QoL; however, DR has a minor additional impact on the overall physical health and QoL in people with ESKD.

Activity of Plasmodium vivax promoter elements in Plasmodium knowlesi, and a centromere-containing plasmid that expresses NanoLuc throughout the parasite life cycle.

BACKGROUND: Plasmodium knowlesi is now the major cause of human malaria in Malaysia, complicating malaria control efforts that must attend to the elimination of multiple Plasmodium species. Recent advances in the cultivation of P. knowlesi erythrocytic-stage parasites in vitro, transformation with exogenous DNA, and infection of mosquitoes with gametocytes from culture have opened up studies of this pathogen without the need for resource-intensive and costly non-human primate (NHP) models. For further understanding and development of methods for parasite transformation in malaria research, this study examined the activity of various trans-species transcriptional control sequences and the influence of Plasmodium vivax centromeric (pvcen) repeats in plasmid-transfected P. knowlesi parasites. METHODS: In vitro cultivated P. knowlesi parasites were transfected with plasmid constructs that incorporated Plasmodium vivax or Plasmodium falciparum 5' UTRs driving the expression of bioluminescence markers (firefly luciferase or Nanoluc). Promoter activities were assessed by bioluminescence, and parasites transformed with human resistant allele dihydrofolate reductase-expressing plasmids were selected using antifolates. The stability of transformants carrying pvcen-stabilized episomes was assessed by bioluminescence over a complete parasite life cycle through a rhesus macaque monkey, mosquitoes, and a second rhesus monkey. RESULTS: Luciferase expression assessments show that certain P. vivax promoter regions, not functional in the more evolutionarily-distant P. falciparum, can drive transgene expression in P. knowlesi. Further, pvcen repeats may improve the stability of episomal plasmids in P. knowlesi and support detection of NanoLuc-expressing elements over the full parasite life cycle from rhesus macaque monkeys to Anopheles dirus mosquitoes and back again to monkeys. In assays of drug responses to chloroquine, G418 and WR9910, anti-malarial half-inhibitory concentration (IC50) values of blood stages measured by NanoLuc activity proved comparable to IC50 values measured by the standard SYBR Green method. CONCLUSION: All three P. vivax promoters tested in this study functioned in P. knowlesi, whereas two of the three were inactive in P. falciparum. NanoLuc-expressing, centromere-stabilized plasmids may support high-throughput screenings of P. knowlesi for new anti-malarial agents, including compounds that can block the development of mosquito- and/or liver-stage parasites.

Interactive Session for Residents and Medical Students on Dermatologic Care for Lesbian, Gay, Bisexual, Transgender, and Queer Patients.

Introduction: Despite increasing emphasis on LGBTQ health in medical education, evidence-based training on LGBTQ patient care in dermatology is lacking. We designed an interactive online didactic session on dermatologic care of LGBTQ patients for medical students and dermatology residents. Methods: Session content was based on continuing medical education articles and incorporated preexisting LGBTQ-inclusive policies, environments, and videos. We implemented the session via a web-based videoconferencing platform as part of a preexisting resident lecture series. We began with a 90-minute lecture on LGBTQ health care disparities and dermatologists' roles, best practices for providing inclusive care, and dermatologic health concerns and screening recommendations in LGBTQ populations. To solidify knowledge and promote practice of learned skills, a 30-minute interactive role-playing session followed where participants acted as observer, patient, or provider in three distinct clinical scenarios pertaining to dermatologic care of LGBTQ patients. Participants completed baseline and follow-up surveys, which included a psychometrically validated clinical skills scale and an ad hoc knowledge assessment. Results: Baseline and follow-up scores from the clinical skills scale increased overall (0.7; 95% CI, 0.5-0.9; p < .001), in self-reported clinical preparedness (1.1; 95% CI, 0.5-1.6; p = .001), and in basic knowledge (0.8; 95% CI, 0.3-1.4; p = .003). Discussion: An online interactive didactive session on dermatological care of LGBTQ patients increased participants' clinical preparedness and basic knowledge. Implementation of similar sessions at other institutions can improve gaps in preparing residents and medical students in dermatological care of LGBTQ patients.

Evidence for linkage of pfmdr1, pfcrt, and pfk13 polymorphisms to lumefantrine and mefloquine susceptibilities in a Plasmodium falciparum cross.

BACKGROUND: Lumefantrine and mefloquine are used worldwide in artemisinin-based combination therapy (ACT) of malaria. Better understanding of drug susceptibility and resistance is needed and can be obtained from studies of genetic crosses. METHODS: Drug response phenotypes of a cross between Plasmodium falciparum lines 803 (Cambodia) and GB4 (Ghana) were obtained as half-maximal effective concentrations (EC50s) and days to recovery (DTR) after 24 h exposure to 500 nM lumefantrine. EC50s of mefloquine, halofantrine, chloroquine, and dihydroartemisinin were also determined. Quantitative trait loci (QTL) analysis and statistical tests with candidate genes were used to identify polymorphisms associated with response phenotypes. RESULTS: Lumefantrine EC50s averaged 5.8-fold higher for the 803 than GB4 parent, and DTR results were 3-5 and 16-18 days, respectively. In 803 × GB4 progeny, outcomes of these two lumefantrine assays showed strong inverse correlation; these phenotypes also correlated strongly with mefloquine and halofantrine EC50s. By QTL analysis, lumefantrine and mefloquine phenotypes mapped to a chromosome 5 region containing codon polymorphisms N86Y and Y184F in the P. falciparum multidrug resistance 1 protein (PfMDR1). Statistical tests of candidate genes identified correlations between inheritance of PfK13 Kelch protein polymorphism C580Y (and possibly K189T) and lumefantrine and mefloquine susceptibilities. Correlations were detected between lumefantrine and chloroquine EC50s and polymorphisms N326S and I356T in the CVIET-type P. falciparum chloroquine resistance transporter (PfCRT) common to 803 and GB4. CONCLUSIONS: Correlations in this study suggest common mechanisms of action in lumefantrine, mefloquine, and halofantrine responses. PfK13 as well as PfMDR1 and PfCRT polymorphisms may affect access and/or action of these arylaminoalcohol drugs at locations of hemoglobin digestion and heme metabolism. In endemic regions, pressure from use of lumefantrine or mefloquine in ACTs may drive selection of PfK13 polymorphisms along with versions of PfMDR1 and PfCRT associated with lower susceptibility to these drugs.

Single-cell transcription analysis of Plasmodium vivax blood-stage parasites identifies stage- and species-specific profiles of expression.

Plasmodium vivax and P. falciparum, the parasites responsible for most human malaria worldwide, exhibit striking biological differences, which have important clinical consequences. Unfortunately, P. vivax, unlike P. falciparum, cannot be cultivated continuously in vitro, which limits our understanding of its biology and, consequently, our ability to effectively control vivax malaria. Here, we describe single-cell gene expression profiles of 9,215 P. vivax parasites from bloodstream infections of Aotus and Saimiri monkeys. Our results show that transcription of most P. vivax genes occurs during short periods of the intraerythrocytic cycle and that this pattern of gene expression is conserved in other Plasmodium species. However, we also identify a strikingly high proportion of species-specific transcripts in late schizonts, possibly associated with the specificity of erythrocyte invasion. Our findings provide new and robust markers of blood-stage parasites, including some that are specific to the elusive P. vivax male gametocytes, and will be useful for analyzing gene expression data from laboratory and field samples.

Transcriptome profiling of Plasmodium vivax in Saimiri monkeys identifies potential ligands for invasion.

Unlike the case in Asia and Latin America, Plasmodium vivax infections are rare in sub-Saharan Africa due to the absence of the Duffy blood group antigen (Duffy antigen), the only known erythrocyte receptor for the P. vivax merozoite invasion ligand, Duffy binding protein 1 (DBP1). However, P. vivax infections have been documented in Duffy-negative individuals throughout Africa, suggesting that P. vivax may use ligands other than DBP1 to invade Duffy-negative erythrocytes through other receptors. To identify potential P. vivax ligands, we compared parasite gene expression in Saimiri and Aotus monkey erythrocytes infected with P. vivax Salvador I (Sal I). DBP1 binds Aotus but does not bind to Saimiri erythrocytes; thus, P. vivax Sal I must invade Saimiri erythrocytes independent of DBP1. Comparing RNA sequencing (RNAseq) data for late-stage infections in Saimiri and Aotus erythrocytes when invasion ligands are expressed, we identified genes that belong to tryptophan-rich antigen and merozoite surface protein 3 (MSP3) families that were more abundantly expressed in Saimiri infections compared with Aotus infections. These genes may encode potential ligands responsible for P. vivax infections of Duffy-negative Africans.

Artemisinin resistance phenotypes and K13 inheritance in a Plasmodium falciparum cross and Aotus model.

Concerns about malaria parasite resistance to treatment with artemisinin drugs (ARTs) have grown with findings of prolonged parasite clearance t1/2s (>5 h) and their association with mutations in Plasmodium falciparum Kelch-propeller protein K13. Here, we describe a P. falciparum laboratory cross of K13 C580Y mutant with C580 wild-type parasites to investigate ART response phenotypes in vitro and in vivo. After genotyping >400 isolated progeny, we evaluated 20 recombinants in vitro: IC50 measurements of dihydroartemisinin were at similar low nanomolar levels for C580Y- and C580-type progeny (mean ratio, 1.00; 95% CI, 0.62-1.61), whereas, in a ring-stage survival assay, the C580Y-type progeny had 19.6-fold (95% CI, 9.76-39.2) higher average counts. In splenectomized Aotus monkeys treated with three daily doses of i.v. artesunate, t1/2 calculations by three different methods yielded mean differences of 0.01 h (95% CI, -3.66 to 3.67), 0.80 h (95% CI, -0.92 to 2.53), and 2.07 h (95% CI, 0.77-3.36) between C580Y and C580 infections. Incidences of recrudescence were 57% in C580Y (4 of 7) versus 70% in C580 (7 of 10) infections (-13% difference; 95% CI, -58% to 35%). Allelic substitution of C580 in a C580Y-containing progeny clone (76H10) yielded a transformant (76H10C580Rev) that, in an infected monkey, recrudesced regularly 13 times over 500 d. Frequent recrudescences of ART-treated P. falciparum infections occur with or without K13 mutations and emphasize the need for improved partner drugs to effectively eliminate the parasites that persist through the ART component of combination therapy.