Nuclear Localization of Human SOD1 in Motor Neurons in Mouse Model and Patient Amyotrophic Lateral Sclerosis: Possible Links to Cholinergic Phenotype, NADPH Oxidase, Oxidative Stress, and DNA Damage.

Amyotrophic lateral sclerosis (ALS) is a fatal disease that causes degeneration of motor neurons (MNs) and paralysis. ALS can be caused by mutations in the gene that encodes copper/zinc superoxide dismutase (SOD1). SOD1 is known mostly as a cytosolic antioxidant protein, but SOD1 is also in the nucleus of non-transgenic (tg) and human SOD1 (hSOD1) tg mouse MNs. SOD1's nuclear presence in different cell types and subnuclear compartmentations are unknown, as are the nuclear functions of SOD1. We examined hSOD1 nuclear localization and DNA damage in tg mice expressing mutated and wildtype variants of hSOD1 (hSOD1-G93A and hSOD1-wildtype). We also studied ALS patient-derived induced pluripotent stem (iPS) cells to determine the nuclear presence of SOD1 in undifferentiated and differentiated MNs. In hSOD1-G93A and hSOD1-wildtype tg mice, choline acetyltransferase (ChAT)-positive MNs had nuclear hSOD1, but while hSOD1-wildtype mouse MNs also had nuclear ChAT, hSOD1-G93A mouse MNs showed symptom-related loss of nuclear ChAT. The interneurons had preserved parvalbumin nuclear positivity in hSOD1-G93A mice. hSOD1-G93A was seen less commonly in spinal cord astrocytes and, notably, oligodendrocytes, but as the disease emerged, the oligodendrocytes had increased mutant hSOD1 nuclear presence. Brain and spinal cord subcellular fractionation identified mutant hSOD1 in soluble nuclear extracts of the brain and spinal cord, but mutant hSOD1 was concentrated in the chromatin nuclear extract only in the spinal cord. Nuclear extracts from mutant hSOD1 tg mouse spinal cords had altered protein nitration, footprinting peroxynitrite presence, and the intact nuclear extracts had strongly increased superoxide production as well as the active NADPH oxidase marker, p47phox. The comet assay showed that MNs from hSOD1-G93A mice progressively (6-14 weeks of age) accumulated DNA single-strand breaks. Ablation of the NCF1 gene, encoding p47phox, and pharmacological inhibition of NADPH oxidase with systemic treatment of apocynin (10 mg/kg, ip) extended the mean lifespan of hSOD1-G93A mice by about 25% and mitigated genomic DNA damage progression. In human postmortem CNS, SOD1 was found in the nucleus of neurons and glia; nuclear SOD1 was increased in degenerating neurons in ALS cases and formed inclusions. Human iPS cells had nuclear SOD1 during directed differentiation to MNs, but mutant SOD1-expressing cells failed to establish wildtype MN nuclear SOD1 levels. We conclude that SOD1 has a prominent nuclear presence in the central nervous system, perhaps adopting aberrant contexts to participate in ALS pathobiology.

Healthcare utilization and outcomes of spinal cord injured veterans with stage 3-4 pressure injuries.

BACKGROUND: Pressure injuries (PI) are a significant source of morbidity for individuals with spinal cord injury/disease (SCI/D). They are also associated with significant healthcare resource utilization including prolonged hospitalizations. However, the long-term outcomes in terms of wound recurrence-free survival, hospital readmission rates, and all-cause mortality in this population remain largely unknown. OBJECTIVE: To examine the clinical characteristics, healthcare utilization and outcomes of SCI Veterans hospitalized at the VA North Texas Health Care System (VANTHCS) SCI inpatient unit with stage 3 and 4 PI, and compare these between those who received a myocutaneous flap surgery (flap patients (FP)) and those treated medically (non-flap patients (NFP)). METHODS: A retrospective chart review was conducted of all adult patients admitted to the VANTHCS SCI/D unit with stage 3 or 4 pelvic PI between 1/1/2013 and 12/31/2018. Healthcare utilization and outcome information was extracted for pre-specified time points. RESULTS: 78 patients met criteria (113 hospitalizations; 27 FP; 51 NFP). Average length of stay (LOS) was 122 days; FP had a significantly higher LOS than NFP (P = 0.01). Average number of consults was 24. Estimated cost per hospitalization was $175,198. Readmission rate within 30 days was 12.39%. The mortality rate within 1 year of discharge was 21.57% for NFP, as opposed to 3.70% in the FP group. Only 5.00% of NFP wounds were healed at discharged with sustained healing at 1 year, significantly less than FP wounds (55.26%, P < 0.01). CONCLUSIONS: Despite the high investment in terms of healthcare utilization, outcomes in terms of wound healing are poor. Additionally, nearly 22% of NFP died within one year of discharge. This calls into question the utility of prolonged hospitalizations for PI in the SCI/D population in terms of wound treatment efficacy, healthcare costs, and patient morbidity/mortality.

Increasing cumulative exposure to volatile anesthetic agents is associated with poorer neurodevelopmental outcomes in children with hypoplastic left heart syndrome.

OBJECTIVES: Despite improved survival in children with hypoplastic left heart syndrome (HLHS), significant concern persists regarding their neurodevelopmental (ND) outcomes. Previous studies have identified patient factors, such as prematurity and genetic syndromes, to be associated with worse ND outcomes. However, no consistent relationships have been identified among modifiable management factors, including cardiopulmonary bypass strategies, and ND outcomes after cardiac surgery in infancy. Studies in immature animals, including primates, have demonstrated neurodegeneration and apoptosis in the brain after certain levels and extended durations of anesthetic exposure. Retrospective human studies have also suggested relationships between adverse ND effects and anesthetic exposure. METHODS: Cumulative minimum alveolar concentration hours (MAC-hrs) of exposure to volatile anesthetic agents (VAA) (desflurane, halothane, isoflurane, and sevoflurane) were collected from an anesthetic database and medical record review for 96 patients with HLHS or variants. ND testing was performed between ages 4 and 5 years, including full-scale IQ, verbal IQ, performance IQ, and processing speed. Four generalized linear modes were hypothesized a priori and tested using a Gaussian (normal) distribution with an identity link. RESULTS: Cumulative VAA exposure ranged from 0 to 35.3 MAC-hrs (median 7.5 hours). Using specified covariates identified previously as significant predictors of ND outcomes, statistically significant relationships were identified between total MAC-hrs exposure and worse full-scale IQ and verbal IQ scores (P's < .05) alone and after adjusting for relevant covariates. CONCLUSIONS: Increased cumulative MAC-hrs exposure to VAA is associated with worse ND outcomes in certain domains in children with HLHS and variants.

Knowledge of diagnosis, treatment history, and risk of late effects among childhood cancer survivors and parents: The impact of a survivorship clinic.

BACKGROUND: Childhood cancer survivors are at risk for treatment-related adverse health outcomes, known as late effects. Through matched and longitudinal cohorts, we assessed the impact of survivorship care on patient and parent knowledge of treatment history and associated health risks. PROCEDURE: Childhood cancer survivors were recruited from a single-institution survivorship clinic and matched with survivors receiving routine follow-up care (controls) on diagnosis, age, and time off therapy. One hundred seventy-four participants completed telephone interviews assessing knowledge of diagnosis, treatment history, and risk of late effects. Additionally, 48 new survivorship patients were followed longitudinally with serial interviews for 18 months. RESULTS: In the case-control study, survivorship participants were more likely than controls to correctly report their diagnosis (98% vs. 90%, P = 0.039) and indicate a previous discussion of risk of late effects (99% vs. 62%, P<0.0001). Compared to controls, survivorship participants were 13% more sensitive reporting chemotherapeutics (95%CI 2.8-23.7%, P = 0.013) and 12% more sensitive reporting late effect risk (95%CI 7.3-16.6%, P<0.0001). In the longitudinal cohort, participants were 7% more sensitive reporting chemotherapeutics (95%CI 5.4-10.8%, P < 0.001) and 9% more sensitive reporting late effect risk (95%CI 5.6-23.8%, P<0.001) at 3 months compared to baseline. In regression analysis, baseline knowledge correlated with subsequent interview performance, and time since survivorship visit correlated with decreased knowledge of late effects, but not diagnosis or treatment history. CONCLUSIONS: Survivorship care was associated with increased knowledge of diagnosis, treatment history, and risk of late effects in both cohorts. Knowledge of late effects decreases with time, suggesting the need for additional educational strategies.