Decreased CREB phosphorylation impairs embryonic retinal neurogenesis in the Oa1-/- mouse model of Ocular albinism.

Mutations in the human Ocular albinism type-1 gene OA1 are associated with abnormal retinal pigment epithelium (RPE) melanogenesis and poor binocular vision resulting from misrouting of ipsilateral retinal ganglion cell (iRGC) axons to the brain. We studied the latter using wild-type (WT) and Oa1-/- mouse eyes. At embryonic stages, the WT RPE-specific Oa1 protein signals through cAMP/Epac1-Erk2-CREB. Following CREB phosphorylation, a pCREB gradient extends from the RPE to the differentiating retinal amacrine and RGCs. In contrast to WT, the Oa1-/- RPE and ventral ciliary-margin-zone, a niche for iRGCs, express less pCREB while their retinas have a disrupted pCREB gradient, indicating Oa1's involvement in pCREB maintenance. Oa1-/- retinas also show hyperproliferation, enlarged nuclei, reduced differentiation, and fewer newborn amacrine and RGCs than WT retinas. Our results demonstrate that Oa1's absence leads to reduced binocular vision through a hyperproliferation-associated block in differentiation that impairs neurogenesis. This may affect iRGC axon's routing to the brain.

Apnea Testing on Conventional Mechanical Ventilation During Brain Death Evaluation.

INTRODUCTION: The use of continuous positive airway pressure has been shown to improve the tolerance of the apnea test, a critical component of brain death evaluation. The ability to deactivate the apnea backup setting has made apnea testing possible using several conventional mechanical ventilators. Our goal was to evaluate the safety and efficacy of apnea testing performed on mechanical ventilation, compared with the oxygen insufflation technique, for the determination of brain death. METHODS: This was a retrospective study. In 2016, our institution approved a change in policy to permit apnea testing on conventional mechanical ventilation. We examined the records of consecutive adults who underwent apnea testing as part of the brain death evaluation process between 2016 and 2022. Using an apnea test technique was decided at the discretion of the attending physician. Outcomes were successful apnea test and the occurrence of patient instability during the test. This included oxygen desaturation (SpO2) < 90%, hypotension (mean arterial pressure < 65 mm Hg despite titration of vasopressor), cardiac arrhythmia, pneumothorax, and cardiac arrest. RESULTS: Ninety-two adult patients underwent apnea testing during the study period: 58 (63%) with mechanical ventilation, 32 (35%) with oxygen insufflation, and 2 (2%) lacked documentation of technique. Apnea tests could not be completed successfully in 3 of 92 (3%) patients-two patients undergoing the oxygen insufflation technique (one patient with hypoxemia and one patient with hypotension) and one patient on mechanical ventilation (aborted for hemodynamic instability). Hypoxemia occurred in 4 of 32 (12.5%) patients with oxygen insufflation and in zero patients on mechanical ventilation (p = 0.01). Hypotension occurred during 3 of 58 (5%) tests with mechanical ventilation and 4 of 32 (12.5%) tests with oxygen insufflation (p = 0.24). In multivariate analysis, the use of oxygen insufflation was an independent predictor of patient instability during the apnea test (odds ratio 37.74, 95% confidence interval 2.74-520.14). CONCLUSIONS: Apnea testing on conventional mechanical ventilation is feasible and offers several potential advantages over other techniques.

Automated Plaque Detection and Agatston Score Estimation on Non-Contrast CT Scans: A Multicenter Study.

Coronary artery calcification (CAC) is a strong and independent predictor of cardiovascular disease (CVD). However, manual assessment of CAC often requires radiological expertise, time, and invasive imaging techniques. The purpose of this multicenter study is to validate an automated cardiac plaque detection model using a 3D multiclass nnU-Net for gated and non-gated non-contrast chest CT volumes. CT scans were performed at three tertiary care hospitals and collected as three datasets, respectively. Heart, aorta, and lung segmentations were determined using TotalSegmentator, while plaques in the coronary arteries and heart valves were manually labeled for 801 volumes. In this work we demonstrate how the nnU-Net semantic segmentation pipeline may be adapted to detect plaques in the coronary arteries and valves. With a linear correction, nnU-Net deep learning methods may also accurately estimate Agatston scores on chest non-contrast CT scans. Compared to manual Agatson scoring, automated Agatston scoring indicated a slope of the linear regression of 0.841 with an intercept of +16 HU (R2 = 0.97). These results are an improvement over previous work assessing automated Agatston score computation in non-gated CT scans.

Blood-Based Biomarkers for Neuroprognostication in Acute Brain Injury.

Acute brain injury causes loss of functionality in patients that often is devastating. Predicting the degree of functional loss and overall prognosis requires a multifaceted approach to help patients, and more so their families, make important decisions regarding plans and goals of care. A variety of blood-based markers have been studied as one aspect of this determination. In this review, we discuss CNS-derived and systemic markers that have been studied for neuroprognostication purposes. We discuss the foundation of each protein, the conditions in which it has been studied, and how the literature has used these markers for interpretation. We also discuss challenges to using each marker in each section as well.

Association Between Open Payments-Reported Industry Transfers of Value and Prostaglandin Analog Prescribing in the US.

Importance: Reported transfers of value (TOV) from pharmaceutical companies have been associated with greater use of branded anti-vascular endothelial growth factor agents by ophthalmologists, but payment under the Medicare Part B buy-and-bill model includes a financial incentive to choose costlier agents, potentially confounding analyses of pharmaceutical TOV and prescribing patterns. How these reported TOV are associated with prescribing patterns for prescription eye drops, not subject to the incentives created by Part B payments, should be considered. Objective: To assess the association between prostaglandin analog (PGA) eye drop prescribing and reported nonresearch TOV by makers of branded PGAs to US vision care professionals. Design, Setting, and Participants: This retrospective cohort analysis used a 20% nationally representative sample of 2018 Medicare Part D claims and industry TOV reported to the Open Payments program. Optometrists and ophthalmologists who had more than 10 claims for PGA drops in the 20% sample were analyzed. Analysis took place from June 2021 to February 2022. Main Outcomes and Measures: Multivariable logistic regression assessing the association between membership in strata of reported TOV and branded PGA prescribing rate, controlling for prescriber demographic factors, local area practices, total PGA prescribing volume, and plan formularies involved. Results: A total of 20 612 ophthalmologists and 5426 optometrists (7449 [29%] female and 18 589 [71%] male) prescribed PGA eye drops. Of these, 9685 (37%) were reported to have received TOV from manufacturers of branded PGAs in 2018, totaling $5 060 346. The median (IQR) reported TOV was $65 ($24-$147). Multivariable logistic regression showed that the predicted probability of primarily prescribing branded PGAs among prescribers who reported receiving no TOV was 12.9% (95% CI, 12.4%-13.4%). This figure increased to 19.6% (95% CI, 18.8%-20.4%) among prescribers receiving TOV, a 50% increase. There was a dose-response association, such that the top 10% of TOV recipients had a 29.2% probability (95% CI, 26.4%-31.9%) of preferential branded use. Conclusions and Relevance: While the median reported TOV to a PGA prescriber was relatively low in this study, there was a positive association between amount of reported nonresearch TOV received from PGA makers and the frequency of branded PGA use. This shows that small reported TOV were associated with differences in prescribing. High rates of branded PGA prescribing may pose a cost burden to patients that affects adherence. Clinicians and policy makers should be aware of these associations.

Incidence, Predictors and Outcomes of Delirium in Critically Ill Patients With COVID-19.

BACKGROUND AND PURPOSE: A variety of neurological manifestations have been attributed to COVID-19, but there is currently limited evidence regarding risk factors and outcomes for delirium in critically ill patients with COVID-19. The purpose of this study was to identify delirium in a large cohort of ICU patients with COVID-19, and to identify associated features and clinical outcomes at the time of hospital discharge. METHODS: This is an observational cohort study of 213 consecutive patients admitted to an ICU for COVID-19 respiratory illness. Delirium was diagnosed by trained abstractors using the CHART-DEL instrument. The associations between key clinical features, sedation and delirium were examined, as were the impacts of delirium on clinical outcomes. RESULTS: Delirium was identified in 57.3% of subjects. Delirious patients were more likely to receive mechanical ventilation, had lower P: F ratios, higher rates of renal replacement therapy and ECMO, and were more likely to receive enteral benzodiazepines. Only mechanical ventilation remained a significant predictor of delirium in a logistic regression model. Mortality was not significantly different, but delirious patients experienced greater mechanical ventilation duration, ICU/hospital lengths of stay, worse functional outcomes at discharge, and were less likely to be discharged home. CONCLUSIONS: Delirium is common in critically ill patients with COVID-19 and appears to be associated with greater disease severity. When present, delirium is associated with worse functional status at discharge, but not increased mortality. Additional studies are necessary to determine the generalizability of these results and the impact of delirium on longer-term cognitive and functional outcomes.

Screening Computed Tomography Angiography to Identify Patients at Low Risk for Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage.

Introduction: Delayed cerebral ischemia (DCI) occurs during a risk period of 3-21 days following aneurysmal subarachnoid hemorrhage (aSAH) and is associated with worse outcomes. The identification of patients at low risk for DCI might permit triage to less intense monitoring and management. While large-vessel vasospasm (LVV) is a distinct clinical entity from DCI, the presence of moderate-to-severe LVV is associated with a higher risk of DCI. Our hypothesis was that the absence of moderate-to-severe LVV on screening computed tomographic angiography (CTA) performed within the first few days of the DCI risk period will accurately identify patients at low risk for subsequent DCI. Methods: This was a retrospective cohort study. Our institutional SAH outcomes registry was queried for all aSAH patients admitted in 2016-2019 who underwent screening CTA brain between days 4 and 8 following ictus. We excluded patients diagnosed with DCI prior to the first CTA performed during this time period. All variables are prospectively entered into the registry, and outcomes including DCI and LVV are prospectively adjudicated. We evaluated the predictive value and accuracy of moderate-to-severe LVV on CTA performed 4-8 days following ictus for the prediction of subsequent DCI. Results: A total of 243 aSAH patients were admitted during the study timeframe. Of the 54 patients meeting the eligibility criteria, 11 (20%) had moderate-to-severe LVV on the screening CTA study performed during the risk period. Seven of the 11 (64%) patients with moderate-to-severe LVV on the days 4-8 screening CTA vs. six of 43 (14%) patients without, subsequently developed DCI. On multivariate analysis, the presence of LVV on days 4-8 screening CTA was an independent predictor of DCI (odds ratio 10.26, 95% CI 1.69-62.24, p = 0.011). NPV for the subsequent development of DCI was 86% (95% CI 77-92%). Sensitivity was 54% (25-81%), specificity 90% (77-97%), and positive predictive value 64% (38-83%). Conclusions: The presence of moderate-to-severe LVV on screening CTA performed between days 4 and 8 following aSAH was an independent predictor of DCI, but achieved only moderate diagnostic accuracy, with NPV 86% and sensitivity 54%. Complementary risk-stratification strategies are likely necessary.

T-Cell Acute Lymphoblastic Leukemia: A Cytogenomic Update.

OBJECTIVES: T-cell acute lymphoblastic leukemia (T-ALL) is a pervasive hematologic malignancy that arises from developmental and genetic abnormalities manifested in lymphoblasts belonging to the T-cell lineage. Responsible for 10-15% of pediatric acute lymphoblastic leukemia (ALL) and 25% of adult ALL patients, T-ALL is characterized not only by cytomorphic features, but also by the aberrant expression of specific genes critical to T-cell development. Such changes in the genome ultimately result in mutational and developmental cascades that alter the chromosomal constitution, the process of which are used to organize T-ALL cases into different subgroups according to specific gene expression signatures. Clinically, comprehensive categorizations are important in risk stratification, assessment, and treatment protocols. Notable genetic subgroups include that of TAL, TLX1, TLX3, HOXA, MYB, ETP and NKX2. Current research also recognizes phenotypic and immunologic categories, such as ALK-positive ALCL, ALK-negative ALCL, BIA ALCL, AITL, and PTCL, NOS, which has revolutionized our understanding of T-cell lymphoma. Furthermore, it has been suggested that most T-ALL patients present with abnormal NOTCH1 genes in addition to mutations involving the JAK-STAT signaling pathway. These abnormalities are associated with the regulatory malfunction of T-cell development as well as that of their respective tumor suppressors and oncogenes. While recent studies have revealed characteristic defects in T-ALL, the interactions between oncogenes and their tumor suppressors with leukemia development are not well known as the signaling pathways involved behind each genetic lesion have yet to be fully explored. Studies involving FISH, RT-PCR, aCGH, and NGS offer novel perspectives to potentially learn more about the pathogenesis and cytogenetics of T-ALL, a field that demands further attention and research.

Molecular Cytogenetic Characterization of a Complex Karyotype of a Pediatric Male Patient with B-Acute Lymphoblastic Leukemia.

OBJECTIVES: B-Acute lymphoblastic leukemia (B-ALL) is a malignant disease that arises from several cooperative genetic mutations in a single B-lymphoid progenitor, leading to altered blast cell proliferation, survival and maturation, and eventually the lethal accumulation of leukemic cells. B-ALL accounts for about 12% of all childhood and adult leukemias diagnosed in developed countries, and 60% of those diagnosed are patients younger than 20 years old. As the most common cancer in children (25% of all cases) with a peak incidence in patients between the ages of two and five years, with a second, smaller peak in the elderly, the factors predisposing children and adults to ALL remain largely unknown. Herein we present an eight-year-old male patient diagnosed with B-ALL. Chromosome studies of 20 G-banded metaphases of the bone marrow detected an abnormal male karyotype with loss of 9p [i(9)(q10)] and loss of 17p [der(17)(?::17q11.2->17p11.2::17p11.2->17qter)] within the context of a complex karyotype in eight metaphase cells. Four of these abnormal metaphases showed additional material of unknown origin on chromosome 12 at p11.2 [add(12)(p11.2)]. Metaphase FISH analysis was crucial to characterize such complex chromosomal abnormalities, underscoring the importance of molecular cytogenetics in characterizing complex karyotypes in this hematological malignancy.

Cytogenetic Findings in a Case of Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN).

OBJECTIVES: Blastic plasmacytoid dendritic cell neoplasm (BPDCN), previously known as natural killer (NK) cell leukemia/lymphoma, is categorized by the World Health Organization as a sole entity. Most often, BPDCN presents with features of both lymphoma and leukemia. The average age at diagnosis is 60 to 70 years and there are more men than women who are diagnosed with BPDCN. Herein we report a 67-year-old female with a recent peripheral blood morphology revealing a hematopoietic leukemia process. Flow cytometry revealed an atypical cell population without B-cell or T-cell lineage expression. It was positive for CD45 and CD123 and negative for CD34. The peripheral blood showed blastic plasmacytoid dendritic cell neoplasm, macrocytic anemia and moderate thrombocytopenia. Chromosome analysis showed an abnormal clone with i(7)(q10) and monosomies of chromosomes 13 and 15. She underwent a bone marrow biopsy. Bone marrow and peripheral blood showed a blastic plasmacytoid dendritic cell neoplasm (BPDCN), hypercellular marrow (estimated 95%) with 90.4% blasts (aspirate smear).

Duplication of the Band q21q27 on the Long Arm of Chromosome 3: A Rare Cytogenetic Event in B-Chronic Lymphocytic Leukemia (B-CLL).

OBJECTIVES: We present the case of an 83-year-old female with a long history of B-CLL followed by observation only. Twelve years after her diagnosis of CLL, routine follow-up chromosome analysis of peripheral blood revealed an abnormal metaphase with a dup(3)(q21q27) in 18 of 20 metaphase cells. To further characterize the abnormal chromosome 3, fluorescence in situ hybridization (FISH) was performed using the Abbott BCL6 probe for 3q27. An additional BCL6 signal was observed in 303 of the 500 interphase nuclei examined. The ISCN was reported as 46,XX,dup(3)(q21q27)[1]/46,XX[2]. nuc ish(5'BCL6, 3'BCL6)x3(5'BCL6 with 3'BCL6x3)[303/500]. This abnormality was seen again in one of three available metaphases in a follow-up peripheral blood study five years later, consistent with persistent disease. Molecular genetic analysis identified the presence of somatic hypermutation of the immunoglobulin heavy chain gene variable region (IGH-V), which is recognized as an independent favorable prognostic marker in CLL. FISH analysis was negative for loss of SEC63 (6q21), amplification of MYC (8q24), loss of ATM (11q22.3), trisomy 12, loss of D13S319 (13q14.3), loss of TP53 (17p13.1) and CCND1/MYEOV IGH rearrangement [t(11;14)(q13;q32.30)]. Partial trisomy 3 is a relatively rare event seen in B-CLL, with commonly overrepresented segments including the q21-23 region and the q25-29 region of the long arm of chromosome 3, as well as changes leading to gains of 3q26- q27. The clinical significance of this finding in B-CLL is uncertain; however, our patient remains well and has not required therapy 17 years after her initial diagnosis.