ABSTRACT
Purpose: To understand the degree and explore the possible causes of ocular graft-versus-host disease (oGVHD) underdiagnosis in patients following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients and Methods: A 15-question survey was emailed to 6032 subscribers to the Blood and Marrow Transplant Information Network. A total of 371 respondents confirmed the history of allo-HSCT, of which 335 were symptomatic. Their self-reported symptoms, onset, treatments tried, degree of symptom control and established diagnoses of systemic chronic graft-versus-host disease (cGVHD) and oGVHD were analyzed. Results: Among the 335 symptomatic survey respondents, 306 reported their ocular symptom onset was after allo-HSCT, with only 170 [55.6% (170/306)] ever receiving a diagnosis of oGVHD; 23 reported worsening pre-existing ocular symptoms after allo-HSCT, with only 5 [21.7% (5/23)] ever receiving a diagnosis of oGVHD; 6 reported stable symptoms before and after allo-HSCT, with 1 ever receiving a diagnosis of oGVHD. Of the 176 respondents carrying the diagnosis of oGVHD, 167 [94.9% (167/176)] also had the diagnosis of cGVHD. Logistic regression analysis showed that the diagnosis of oGVHD was highly correlated with the number of symptoms and treatments one reported. Furthermore, 35% of the respondents with new onset ocular symptoms reported onset within the first 6 months after allo-HSCT (previously reported), as well as 39% of the respondents with worsened existing symptoms. Conclusion: oGVHD underdiagnosis is likely associated with the previous diagnostic criteria, in which cGVHD of another organ system was required. The correct notion that oGVHD commonly causes severe dry eye disease has likely led to its underdiagnosis in patients with fewer number of symptoms and/or who tried fewer treatments.
ABSTRACT
Head injury is a known risk factor for Parkinson's disease. Disruption in the perivascular clearance of metabolic waste and unwanted proteins is thought to be a contributing factor to disease progression. We hypothesized that repetitive mild head impacts, without evidence of structural brain damage, would increase microgliosis and AQP4 expression and depolarization and alter perivascular flow in the midbrain dopaminergic system. Adult male rats were subjected to sham, or two mild head impacts separated by 48 h. Three weeks later, fully awake rats were imaged using dynamic, contrast-enhanced MRI to follow the distribution of intraventricular gadobenate dimeglumine contrast agent. Images were registered to and analysed using a 3D MRI rat atlas providing site-specific data on 171 different brain areas. Following imaging, rats were tested for cognitive function using the Barnes maze assay. Histological analyses of tyrosine hydroxylase, microglia activation and AQP4 expression and polarization were performed on a parallel cohort of head impacted rats at 20 days post insult to coordinate with the time of imaging. There was no change in the global flux of contrast agent between sham and head impacted rats. The midbrain dopaminergic system showed a significant decrease in the influx of contrast agent as compared to sham controls together with a significant increase in microgliosis, AQP4 expression and depolarization. There were no deficits in cognitive function. The histology showed a significant level of neuroinflammation in the midbrain dopaminergic system 3 weeks post mild repetitive head impact but no loss in tyrosine hydroxylase. MRI revealed no structural brain damage emphasizing the potential serious consequences of mild head impacts on sustained brain neuroinflammation in this area critical to the pathophysiology of Parkinson's.
ABSTRACT
PURPOSE: To evaluate the utilization of scleral lenses and prosthetic replacement of the ocular surface ecosystem devices (SL/PDs) in the management of ocular graft-versus-host disease (oGVHD). PATIENTS AND METHODS: A survey of 15 questions was sent via email to 6032 subjects registered with the Blood and Marrow Transplant Information Network. The survey reviewed transplant history, graft-versus-host disease history, as well as oGVHD symptoms and onset. Additional questions surveyed treatments used for oGVHD, as well as the degree of ocular symptom control and experience with SL/PDs. A total of 306 respondents met the eligibility requirements to be part of the analyzed cohort. RESULTS: The mean number of symptoms reported from the analyzed cohort was 4.79 ± 2.44, median (IQR) of 5.0 (3.0 to 7.0), with the most common symptom being gritty, dry eyes (87%). The mean number of treatments utilized across the analyzed cohort was 3.21 ± 2.55, median (IQR) of 2.5 (1.0 to 5.0), with the most common treatment being artificial tears (86%). Wearing scleral lenses resulted in a mean of 5.42 ± 1.86, median (IQR) of 6.0 (4.0 to 7.0) symptoms improving, with improved dryness/grittiness of the eyes (94%), improved eye pain (92%) and improved quality of life (89%) being the most commonly improved symptoms. Fifty-six percent of those wearing scleral lenses wished the lenses had been recommended sooner. The most common reason patients cited for not wearing scleral lenses was that they had never heard of them (63%). CONCLUSION: SL/PDs help to control the symptoms of oGVHD. With their use, clinicians are able to improve the quality of life of this patient population. Despite the known benefits, SL/PDs still remain underutilized in oGVHD care. A majority of current SL/PD wearers wish that they had been recommended sooner as a treatment option. SL/PDs should be considered a component of comprehensive oGVHD management.
ABSTRACT
INTRODUCTION: Novel sensors were developed to detect exhaled volatile organic compounds to aid in the diagnosis of mild cognitive impairment associated with early stage Alzheimer's disease (AD). The sensors were sensitive to a rat model that combined the human apolipoprotein E (APOE)4 gene with aging and the Western diet. METHODS: Gas sensors fabricated from molecularly imprinted polymer-graphene were engineered to react with alkanes and small fatty acids associated with lipid peroxidation. With a detection sensitivity in parts per trillion the sensors were tested against the breath of wild-type and APOE4 male rats. Resting state BOLD functional connectivity was used to assess hippocampal function. RESULTS: Only APOE4 rats, and not wild-type controls, tested positive to several small hydrocarbons and presented with reduced functional coupling in hippocampal circuitry. DISCUSSION: These results are proof-of-concept toward the development of sensors that can be used as breath detectors in the diagnosis, prognosis, and treatment of presymptomatic AD.
