Mechanistic understanding and potential targets for mustard gas keratopathy

Sulfur mustard gas (SM), a vesicating and alkylating agent, has been used as a warfare agent since World War I and recently in Syria. SM exposure causes severe corneal injury, pain, and irreversible blindness. The cornea provides twothirds of the eye's light refraction vital for vision. Clinically, SM rapidly penetrates the cornea after exposure and causes a grade-3 or grade-4 clinical pathology called mustard gas keratopathy (MGK). MGK is characterized by ocular inflammation, loss of epithelial barrier, recurrent epithelial erosions, epithelialstromal separation, haze/fibrosis, and neovascularization in the cornea. Despite the high risk of SM for terrorism and mass obliteration, the pathophysiological mechanisms associated with MGK remain elusive. MGK-related corneal haze/fibrosis results from the transdifferentiation of keratocytes into pathological cellular phenotype called myofibroblasts that cause massive overproduction of collagen during wound healing. Keratocytes and collagens residing in the stroma play an essential role in maintaining corneal transparency and are regulated by cytokines and chemokines. The predominant collagens in the stroma are Type I, V, and VII. Additionally, a unique arrangement of collagen fibrils is required for transparency and corneal function. Collagen fibrils are narrow with uniform diameter and arranged with a high degree of lateral ordering. The mechanisms involving myofibroblast formation and collagen derangement after mustard gas exposure are unknown. Presently, a major knowledge gap is how SM exposure affects myofibroblast generation and collagen fibril arrangement in the wounded cornea. My dissertation fills this knowledge gap through successful testing of a novel central hypothesis that mustard gas exposure to the eye results in corneal haze/fibrosis by excessive production of myofibroblasts via TGFβ/SMAD signaling and alters the distinctive organization of collagen fibrils by regulating LOX activity via PI3K/MAPK signaling in the stroma. The formation of haze/fibrosis post SM exposure was tested using an in vivo rabbit model, in which live New Zealand White rabbits received SM vapor exposure localized to the eye. The goals of my PhD thesis were to characterize time-dependent changes in the stroma in live animals in situ employing eye examinations and state-of-the-art multimodal clinical ophthalmic imaging techniques in live rabbits with Stereo, Slit-lamp, HRT-RCM3, and Spectralis microscopy system. Fantes grading, fluorescein staining, Schirmer's tests, pachymetry, and applanation tonometry were conducted to measure levels of corneal haze, ocular surface healing, tears, corneal thickness, and intraocular pressure, respectively. H and E and PSR staining were used for histopathological cellular changes in the cornea. In vivo confocal and OCT imaging revealed significant changes in structural and morphological appearance of the cornea in vivo in SM-exposed rabbit corneas in a time-dependent manner compared to naive cornea (p [less than] 0.001 or p [less than] 0.0001). Also, SM-exposed eyes showed loss of corneal transparency characterized by increased stromal thickness (p [less than] 0.0001), debris, and light-scattering myofibroblasts or activated keratocytes, representing haze formation in the cornea. Naive eyes did not show any structural, cellular, and functional abnormalities. SM exposure showed increased central corneal thickness, ocular edema and tearing compared to the eyes of the naive (p [less than] 0.001 or p [less than] 0.0001). This study concluded that structural and cellular changes in primary corneal layers are early pathological events contributing to MGK in vivo. Next, I tested if TGFβ/SMAD is a major molecular mechanism for myofibroblast formation following SM exposure. Rabbit corneas exposed to SM had a time-dependent increase in [alpha]SMA, a maker for myofibroblast formation. Additionally, using an established in vitro model of primary human corneal fibroblasts (hCSF) treated with nitrogen mustard (NM), an analogous agent to SM, or NM+SMAD inhibitors, I verified my hypothesis that SMAD is a predominant pathway for myofibroblast formation in MGK. Primary hCSF treated with NM showed a significant time-dependent increase (p [less than] 0.05, p [less than] 0.01) in [alpha]SMA expression which was significantly decreased by SMAD inhibitors (p [less than] 0.05, p [less than] 0.01). This data strongly supported my notion that SMAD is a major pathway for myofibroblast formation in corneal stroma after mustard gas exposure. The final section of my thesis tested another novel postulate that lysyl oxidase (LOX) is a possible mechanism to cause changes in the collagen lamella. LOX activity regulates extracellular cross-linking; however, literature/knowledge on LOX function in the cornea is very limited. Thus, I tested if p38 and PI3K are major regulatory pathways. p38 and PI3K have shown to regulate steady state LOX mRNA in cardiac fibroblasts. An in vitro study using hCSF cells, NM, p38 inhibitor, and PI3K inhibitor concluded that (a) p38 follow the pattern similar to SMAD signaling, and (b) PI3K was directly related to LOX production. Subsequent research showed that p38 has a function correlative to SMAD function in the corneal epithelium. This finding was the first to identify the role of PI3K in the mustard gas exposed corneal stroma. In conclusion, my dissertation identified time-dependent in situ structural and cellular aberrations in the rabbit cornea in vivo after mustard gas exposure and remarkably improved mechanistic knowledge that will be instrumental in developing novel strategies and molecular targets for newer therapeutics to prevent and treat corneal mustard gas keratopathy. Additionally, it might help understanding corneal pathologies caused by other alkylating/vesicating agents.Includes bibliographical references

Science, Technology and Innovation Equity and Inclusion in Electric Vehicle Sector

The rapid growth of the electric vehicle (EV) industry offers a unique chance to ensure that technological progress benefits all of society. This research paper centers on developing indicators to assess and encourage equity and inclusion in EV science, technology, and innovation. By establishing a comprehensive framework, this study aims to track progress, pinpoint areas for enhancement, and contribute to a more just and innovative future. The paper emphasizes clear goals, including increased workforce diversity, equitable EV technology access for marginalized communities, and fostering an inclusive innovation ecosystem. Collaboration with diverse stakeholders researchers, policymakers, industry experts, community representatives, and advocacy groups is crucial for an unbiased perspective. Key areas within the EV sector are focal points for equity and inclusion efforts, such as workforce diversity, research funding distribution, technology accessibility, and community engagement. To measure progress, indicators are developed, incorporating qualitative aspects. Targets and benchmarks are set for each indicator to promote a challenging yet achievable path toward equity. Regular monitoring and reporting provide insights into intervention effectiveness, guided by stakeholder feedback and iteration. Acknowledging and celebrating equity and inclusion achievements motivate sustained progress. Knowledge sharing and community collaboration promote collective growth and better understanding of best practices. This research paper offers a comprehensive guide to developing indicators that assess and promote equity and inclusion in the EV science, technology, and innovation sectors. Applying these indicators and strategies enables stakeholders to contribute to a more just and innovative future, ensuring that technological benefits are accessible to all members of society

Thiazides in advanced chronic kidney disease—time for a randomized controlled trial?

Purpose of review: Chronic kidney disease is common, associated with increased cardiovascular risk, and frequently complicated by hypertension, requiring multiple agents for control. Thiazides are naturally attractive for use in this population; unfortunately, they are classically thought to be ineffective in advanced chronic kidney disease based on both theoretical considerations and the earliest studies of these agents. This report reviews the studies of thiazide use in chronic kidney disease since the 1970s, including five randomized controlled trials, all of which report at least some degree of efficacy. Recent findings: Two recent studies add further evidence for the utility and efficacy of thiazides in chronic kidney disease. Of these two, one used gold standard ambulatory blood pressure monitoring in patients with poorly controlled hypertension and advanced chronic kidney disease and found chlorthalidone reduces blood pressure. The second is the largest study to date of thiazides in chronic kidney disease; adding a fixed low-dose chlorthalidone as the first diuretic to the antihypertensive regimen improved blood pressure. Summary: These numerous small but positive studies reinforce the need for a randomized trial to demonstrate safety and efficacy of thiazides in advanced chronic kidney disease

Hypertension Treatment for Patients with Advanced Chronic Kidney Disease

Chronic kidney disease is common and frequently complicated with hypertension. As a major modifiable risk factor for cardiovascular disease in this high risk population, treatment of hypertension in chronic kidney disease is of paramount importance. We review the epidemiology and pathogenesis of hypertension in chronic kidney disease and then update the latest study results for treatment including salt restriction, invasive endovascular procedures, and pharmacologic therapy. Recent trials draw into question the efficacy of renal artery stenting or renal denervation for hypertension in chronic kidney disease, as well as renin-angiotensin-aldosterone system blockade as first line therapy of hypertension in end stage renal disease. Positive trial results reemphasize salt restriction and challenge the prevailing prejudice against the use of thiazide-like diuretics in advanced chronic kidney disease. Lastly, clinical practice guidelines are trending away from recommending tight blood pressure control in chronic kidney disease

Setting the dry weight and its cardiovascular implications

Volume overload is common and associated with adverse outcomes in the hemodialysis population including systemic hypertension, pulmonary hypertension, left ventricular hypertrophy, and mortality. Since the beginning of the era of maintenance dialysis, prescribing and maintaining a dry weight remains the standard of care for managing volume overload on hemodialysis. Reducing dry weight even by relatively small amounts has been shown to improve blood pressure and has been associated with reductions in left ventricular hypertrophy. Maintaining an adequately low dry weight requires attention to sodium intake and adequate time on dialysis, as well as a high index of suspicion for volume overload. Reducing dry weight can provoke decreased cardiac chamber filling and is associated with risks including intradialytic hypotension. The ideal method to minimize intradialytic morbidity is unknown, but more frequent dialysis should be considered. Experimental methods of assessing volume status may allow identification of patients most likely both to tolerate and to benefit from dry weight reduction, but further study is needed