Inhibiting Inducible Nitric Oxide Synthase with 1400W Reduces Soman (GD)-Induced Ferroptosis in Long-Term Epilepsy-Associated Neuropathology: Structural and Functional Magnetic Resonance Imaging Correlations with Neurobehavior and Brain Pathology.

Organophosphate (OP) nerve agent (OPNA) intoxication leads to long-term brain dysfunctions. The ineffectiveness of current treatments for OPNA intoxication prompts a quest for the investigation of the mechanism and an alternative effective therapeutic approach. Our previous studies on 1400W, a highly selective inducible nitric oxide synthase (iNOS) inhibitor, showed improvement in epilepsy and seizure-induced brain pathology in rat models of kainate and OP intoxication. In this study, magnetic resonance imaging (MRI) modalities, behavioral outcomes, and biomarkers were comprehensively investigated for brain abnormalities following soman (GD) intoxication in a rat model. T1 and T2 MRI robustly identified pathologic microchanges in brain structures associated with GD toxicity, and 1400W suppressed those aberrant alterations. Moreover, functional network reduction was evident in the cortex, hippocampus, and thalamus after GD exposure, and 1400W rescued the losses except in the thalamus. Behavioral tests showed protection by 1400W against GD-induced memory dysfunction, which also correlated with the extent of brain pathology observed in structural and functional MRIs. GD exposure upregulated iron-laden glial cells and ferritin levels in the brain and serum, 1400W decreased ferritin levels in the epileptic foci in the brain but not in the serum. The levels of brain ferritin also correlated with MRI parameters. Further, 1400W mitigated the overproduction of nitroxidative markers after GD exposure. Overall, this study provides direct evidence for the relationships of structural and functional MRI modalities with behavioral and molecular abnormalities following GD exposure and the neuroprotective effect of an iNOS inhibitor, 1400W. SIGNIFICANT STATEMENT: Our studies demonstrate the MRI microchanges in the brain following GD toxicity, which strongly correlate with neurobehavioral performances and iron homeostasis. The inhibition of iNOS with 1400W mitigates GD-induced cognitive decline, iron dysregulation, and aberrant brain MRI findings.

Volumetric measurement of terminal ileal Crohn's disease by magnetic resonance enterography: a feasibility study.

OBJECTIVES: Magnetic resonance enterography (MRE) interpretation of Crohn's disease (CD) is subjective and uses 2D analysis. We evaluated the feasibility of volumetric measurement of terminal ileal CD on MRE compared to endoscopy and sMARIA, and the responsiveness of volumetric changes to biologics. METHODS: CD patients with MRE and contemporaneous CD endoscopic index of severity-scored ileocolonoscopy were included. A centreline was placed through the terminal ileum (TI) lumen defining the diseased bowel length on the T2-weighted non-fat saturated sequence, used by two radiologists to independently segment the bowel wall to measure volume (phase 1). In phase 2, we measured disease volume in patients treated with biologics, who had undergone pre- and post-treatment MRE, with treatment response classified via global physician assessment. RESULTS: Phase 1 comprised 30 patients (median age 29 (IQR 24, 34) years). Phase 2 included 12 patients (25 years (22, 38)). In phase 1, the mean of the radiologist-measured volumes was used for analysis. The median disease volume in those with endoscopically active CD was 20.9 cm3 (IQR 11.3, 44.0) compared to 5.7 cm3 (2.9, 9.8) with normal endoscopy. The mean difference in disease volume between the radiologists was 3.0 cm3 (limits of agreement -21.8, 15.9). The median disease volume of patients with active CD by sMARIA was 15.0 cm3 (8.7, 44.0) compared to 2.85 cm3 (2.6, 3.1) for those with inactive CD. Pre- and post-treatment median disease volumes were 28.5 cm3 (26.4, 31.2), 11 cm3 (4.8, 16.6), respectively in biological responders, vs 26.8 cm3 (12.3, 48.7), 40.1 cm3 (10, 56.7) in non-responders. CONCLUSION: Volumetric measurement of terminal ileal CD by MRE is feasible, related to endoscopy and sMARIA activity, and responsive to biologics. CLINICAL RELEVANCE STATEMENT: Measuring the whole volume of diseased bowel on MRE in CD is feasible, related to how biologically active the disease is when assessed by endoscopy and by existing MRE activity scores, and is sensitive to treatment response. KEY POINTS: MRE reporting for CD is subjective and uses 2D images rather than assessing the full disease volume. Volumetric measurement of CD relates to endoscopic activity and shows reduced disease volumes in treatment responders. This technique is an objective biomarker that can assess disease activity and treatment response, warranting validation.

Impact of CYP3A5 genotype on de-novo LCP tacrolimus dosing and monitoring in kidney transplantation.

OBJECTIVES: LCP tac has a recommended starting dose of 0.14 mg/kg/day in kidney transplant. The goal of this study was to assess the influence of CYP3A5 on perioperative LCP tac dosing and monitoring. METHODS: This was a prospective observational cohort study of adult kidney recipients receiving de-novo LCP tac. CYP3A5 genotype was measured and 90-day pharmacokinetic and clinical were assessed. Patients were classified as CYP3A5 expressors (*1 homozygous or heterozygous) or nonexpressors (LOF *3/*6/*7 allele). RESULTS: In this study, 120 were screened, 90 were contacted and 52 provided consent; 50 had genotype results, and 22 patients expressed CYP3A5*1. African Americans (AA) comprised 37.5% of nonexpressors versus 81.8% of expressors (P = 0.001). Initial LCP tac dose was similar between CYP3A5 groups (0.145 vs. 0.137 mg/kg/day; P = 0.161), whereas steady state dose was higher in expressors (0.150 vs. 0.117 mg/kg/day; P = 0.026). CYP3A5*1 expressors had significantly more tac trough concentrations of less than 6 ng/ml and significantly fewer tac trough concentrations of more than 14 ng/ml. Providers were significantly more likely to under-adjust LCP tac by 10 and 20% in CYP3A5 expressors versus nonexpressors (P < 0.03). In sequential modeling, CYP3A5 genotype status explained the LCP tac dosing requirements significantly more than AA race. CONCLUSION: CYP3A5*1 expressors require higher doses of LCP tac to achieve therapeutic concentrations and are at higher risk of subtherapeutic trough concentrations, persisting for 30-day posttransplant. LCP tac dose changes in CYP3A5 expressors are more likely to be under-adjusted by providers.

Disease-modifying effects of a glial-targeted inducible nitric oxide synthase inhibitor (1400W) in mixed-sex cohorts of a rat soman (GD) model of epilepsy.

BACKGROUND: Acute exposure to seizurogenic organophosphate (OP) nerve agents (OPNA) such as diisopropylfluorophosphate (DFP) or soman (GD), at high concentrations, induce immediate status epilepticus (SE), reactive gliosis, neurodegeneration, and epileptogenesis as a consequence. Medical countermeasures (MCMs-atropine, oximes, benzodiazepines), if administered in < 20 min of OPNA exposure, can control acute symptoms and mortality. However, MCMs alone are inadequate to prevent OPNA-induced brain injury and behavioral dysfunction in survivors. We have previously shown that OPNA exposure-induced SE increases the production of inducible nitric oxide synthase (iNOS) in glial cells in both short- and long- terms. Treating with a water soluble and highly selective iNOS inhibitor, 1400W, for 3 days significantly reduced OPNA-induced brain changes in those animals that had mild-moderate SE in the rat DFP model. However, such mitigating effects and the mechanisms of 1400W are unknown in a highly volatile nerve agent GD exposure. METHODS: Mixed-sex cohort of adult Sprague Dawley rats were exposed to GD (132 µg/kg, s.c.) and immediately treated with atropine (2 mg/kg, i.m) and HI-6 (125 mg/kg, i.m.). Severity of seizures were quantified for an hour and treated with midazolam (3 mg/kg, i.m.). An hour post-midazolam, 1400W (20 mg/kg, i.m.) or vehicle was administered daily for 2 weeks. After behavioral testing and EEG acquisition, animals were euthanized at 3.5 months post-GD. Brains were processed for neuroinflammatory and neurodegeneration markers. Serum and CSF were used for nitrooxidative and proinflammatory cytokines assays. RESULTS: We demonstrate a significant long-term (3.5 months post-soman) disease-modifying effect of 1400W in animals that had severe SE for > 20 min of continuous convulsive seizures. 1400W significantly reduced GD-induced motor and cognitive dysfunction; nitrooxidative stress (nitrite, ROS; increased GSH: GSSG); proinflammatory cytokines in the serum and some in the cerebrospinal fluid (CSF); epileptiform spikes and spontaneously recurring seizures (SRS) in males; reactive gliosis (GFAP + C3 and IBA1 + CD68-positive glia) as a measure of neuroinflammation, and neurodegeneration (especially parvalbumin-positive neurons) in some brain regions. CONCLUSION: These findings demonstrate the long-term disease-modifying effects of a glial-targeted iNOS inhibitor, 1400W, in a rat GD model by modulating reactive gliosis, neurodegeneration (parvalbumin-positive neurons), and neuronal hyperexcitability.

Impact of obesity on the conversion of immediate-release tacrolimus to extended-release tacrolimus in kidney transplant recipients.

Outcomes analyzing conversion from IR-tacrolimus (IR) to LCP-tacrolimus (LCP) in obesity are limited. This was a retrospective longitudinal cohort study of patients converted from IR to LCP from June 2019 to October 2020. Primary outcomes were conversion ratios for weight-based dose at a steady-state therapeutic level and identification of appropriate dosing weight. Other outcomes included tacrolimus coefficient of variation (CV), time in therapeutic range (TITR), adverse events, infections, donor specific antibodies (DSAs), and acute rejection. A total of 292 patients were included; 156 and 136 patients with a BMI < 30 and BMI ≥ 30 kg/m2 , respectively. Baseline characteristics were similar, except for pancreas transplant, diabetes, and HLA mismatch. IR to LCP conversion ratio ranged from .73 to .79. Mean LCP dose was similar (.08 vs. .07 mg/kg/day for BMI < 30 and BMI ≥ 30 kg/m2 , respectively); there was a significant difference in IR and LCP mg/kg dosing at steady state with TBW (.11 mg/kg vs.09 mg/kg and .08 mg/kg vs. .06 mg/kg, respectively). The most appropriate dosing weight was adjusted body weight (AdjBW), consistent across IR and LCP steady-state doses, and might yield more accurate steady-state dosing requirements. In multivariable modeling, BMI was a significant predictor of steady state mg/kg dosing at therapeutic goal for total body weight (TBW), but not ideal body weight (IBW) or AdjBW.

Impact of converting adult kidney transplant recipients with high tacrolimus variability from twice daily immediate release tacrolimus to once daily LCP-Tacrolimus.

BACKGROUND: The influence of converting to once daily, extended-release LCP-Tacrolimus (Tac) for those with high tacrolimus variability in kidney transplant recipients (KTRs) is not well-studied. METHODS: Single-center, retrospective cohort study of adult KTRs converted from Tac immediate release to LCP-Tac 1-2 years post-transplant. Primary measures were Tac variability, using the coefficient of variation (CV) and time in therapeutic range (TTR), as well as clinical outcomes (rejection, infections, graft loss, death). RESULTS: A total of 193 KTRs included with a follow-up of 3.2 ± .7 years and 1.3 ± .3 years since LCP-Tac conversion. Mean age was 52 ± 13 years; 70% were African American, 39% were female, 16% living donor and 12% donor after cardiac death (DCD). In the overall cohort, tac CV was 29.5% before conversion, which increased to 33.4% after LCP-Tac (p = .008). In those with Tac CV >30% (n = 86), conversion to LCP-Tac reduced variability (40.6% vs. 35.5%; p = .019) and for those with Tac CV >30% and nonadherence or med errors (n = 16), LCP-Tac conversion substantially reduced Tac CV (43.4% vs. 29.9%; p = .026). TTR significantly improved for those with Tac CV >30% with (52.4% vs. 82.8%; p = .027) or without nonadherence or med errors (64.8% vs. 73.2%; p = .005). CMV, BK, and overall infections were significantly higher prior to LCP-Tac conversion. In the overall cohort, 3% had rejection before conversion and 2% after (p = NS). At end of follow-up, graft and patient survival were 94% and 96%, respectively. CONCLUSIONS: In those with high Tac CV, conversion to LCP-Tac is associated with a significant reduction in variability and improvement in TTR, particularly in those with nonadherence or medication errors.

Diabetes is a significant and independent predictor for tacrolimus immediate release and LCP-tacrolimus conversion ratios.

Diabetes (DM) is a common comorbidity in transplant patients with known effects on gastrointestinal (GI) motility and absorption; however, DM's impact on immediate release (IR) tacrolimus to LCP-tacrolimus (LCP) conversion ratios has not been studied. This multivariable analysis of a retrospective longitudinal cohort study included kidney transplant recipients converted from IR to LCP between 2019 and 2020. The primary outcome was IR to LCP conversion ratio based on DM status. Other outcomes included tacrolimus variability, rejection, graft loss, and death. Of the 292 patients included, 172 patients had DM and 120 did not. The IR:LCP conversion ratio was significantly higher with DM (67.5% ± 21.1% no DM vs. 79.8% ± 28.7% in DM; P < .001). In multivariable modeling, DM was the only variable significantly and independently associated with IR:LCP conversion ratios. No difference was observed in rejection rates. Graft (97.5% no DM vs. 92.4% in DM; P = .062) and patient survival (100% no DM vs. 94.8% in DM; P = .011) were lower with DM. The presence of DM significantly increased the IR:LCP conversion ratio by 13%-14%, compared to patients without DM. On multivariable analysis, DM was the only significant predictor of conversion ratios, potentially related to GI motility or absorption differences.

Clinical Profile and Outcome of Patients presenting with Guillain - Barré Syndrome in a Medical Intensive Care Unit of a Tertiary Care Hospital.

BACKGROUND: Guillain-Barré syndrome (GBS) is an inflammatory, autoimmune disorder of the peripheral nervous system that is acute in onset, self-limited, and can result in significant morbidity, placing a burden on the healthcare system. This study aims to study the clinical profile and outcome of patients with GBS who require intensive care unit (ICU) and mechanical ventilation (MV). MATERIALS AND METHODS: After Institutional Ethics Committee approval, a single-center, prospective, observational study was conducted, recruiting 51 patients from the medical ICU with GBS over 18 months. Patients were categorized into three groups as per the timing of the commencement of immunomodulator therapy. The association between dependent variables like the need for MV, patient outcome, and independent factors like time of initiation of immunomodulator therapy from the time of onset of symptoms and age-groups; were analyzed using the Chi-squared test and the overall disability sum score (ODSS) with Spearman's rank correlation test. RESULTS: Out of 51 patients in the study, (52.94%) were male, with a male:female ratio of 1.12:1. Most of them had quadriparesis (98.04%) or bulbar symptoms (56.86%). A total of 24 (47.05%) patients required MV. The presence of bulbar weakness at admission had a statistically significant positive correlation with the need for MV (Spearman's ρ = 0.663, p = 0.001), the need for prolonged MV (Spearman's ρ = 0.457, p = 0.001), duration of MV (Spearman's ρ = 0.512, p = 0.001) and duration of ICU stay (Spearman's ρ = 0.516, p = 0.001); and a negative correlation with improvement in ODSS (Spearman's ρ = -0.409, p = 0.001). Early commencement of immunomodulator therapy was associated with a significantly decreased probability of requiring ventilatory support (p = 0.001), decreased probability of requiring prolonged MV (p = 0.04), and a decreased duration of ICU stay (p = 0.004). CONCLUSION: Early commencement of immunomodulator therapy decreased the probability of requiring ventilatory support and improved the outcome. Breathlessness and bulbar symptoms at admission were poor prognostic indicators in terms of the need for MV and the duration of both the ICU stay and MV.

Are preoperative CT variables associated with the success or failure of subsequent ventral hernia repair: nested case-control study.

OBJECTIVES: Systematic review of CT measurements to predict the success or failure of subsequent ventral hernia repair has found limited data available in the indexed literature. To rectify this, we investigated multiple preoperative CT metrics to identify if any were associated with postoperative reherniation. METHODS: Following ethical permission, we identified patients who had undergone ventral hernia repair and had preoperative CT scanning available. Two radiologists made multiple measurements of the hernia and abdominal musculature from these scans, including loss of domain. Patients were divided subsequently into two groups, defined by hernia recurrence at 1-year subsequent to surgery. Hypothesis testing investigated any differences between CT measurements from each group. RESULTS: One hundred eighty-eight patients (95 male) were identified, 34 (18%) whose hernia had recurred by 1-year. Only three of 34 CT measurements were significantly different when patients whose hernia had recurred were compared to those who had not; these significant findings were assumed contingent on multiple testing. In particular, preoperative hernia volume (recurrence 155.3 cc [IQR 355.65] vs. no recurrence 78.2 [IQR 303.52], p = 0.26) nor loss of domain, whether calculated using the Tanaka (recurrence 0.02 [0.04] vs. no recurrence 0.009 [0.04], p = 0.33) or Sabbagh (recurrence 0.019 [0.05] vs. no recurrence 0.009 [0.04], p = 0.25) methods, differed between significantly between groups. CONCLUSIONS: Preoperative CT measurements of ventral hernia morphology, including loss of domain, appear unrelated to postoperative recurrence. It is likely that the importance of such measurements to predict recurrence is outweighed by other patient factors and surgical reconstruction technique. KEY POINTS: • Preoperative CT scanning is often performed for ventral hernia but systematic review revealed little data regarding whether CT variables predict postoperative reherniation. • We found that the large majority of CT measurements, including loss of domain, did not differ significantly between patients whose hernia did and did not recur. • It is likely that the importance of CT measurements to predict recurrence is outweighed by other patient factors and surgical reconstruction technique.

Radiation Therapy is Associated with Improved Outcomes in Merkel Cell Carcinoma.

BACKGROUND: Following wide excision of Merkel cell carcinoma (MCC), postoperative radiation therapy (RT) is typically recommended. Controversy remains as to whether RT can be avoided in selected cases, such as those with negative margins. Additionally, there is evidence that RT can influence survival. METHODS: We included 171 patients treated for non-metastatic MCC from 1994 through 2012 at a single institution. Patients without pathologic nodal evaluation (clinical N0 disease) were excluded to reflect modern treatment practice. The endpoints included local control (LC), locoregional control (LRC), disease-free survival (DFS), overall survival (OS), and disease-specific survival (DSS). RESULTS: Median follow-up was 33 months. Treatment with RT was associated with improved 3-year LC (91.2 vs. 76.9 %, respectively; p = 0.01), LRC (79.5 vs. 59.1 %; p = 0.004), DFS (57.0 vs. 30.2 %; p < 0.001), and OS (73 vs. 66 %; p = 0.02), and was associated with improved 3-year DSS among node-positive patients (76.2 vs. 48.1 %; p = 0.035), but not node-negative patients (90.1 vs. 80.8 %; p = 0.79). On multivariate analysis, RT was associated with improved LC [hazard ratio (HR) 0.18, 95 % confidence interval (CI) 0.07-0.46; p < 0.001], LRC (HR 0.28, 95 % CI 0.14-0.56; p < 0.001), DFS (HR 0.42, 95 % CI 0.26-0.70; p = 0.001), OS (HR 0.53, 95 % CI 0.31-0.93; p = 0.03), and DSS (HR 0.42, 95 % CI 0.26-0.70; p = 0.001). Patients with negative margins had significant improvements in 3-year LC (90.1 vs. 75.4 %; p < 0.001) with RT. Deaths not attributable to MCC were relatively evenly distributed between the RT and no RT groups (28.5 and 29.3 % of patients, respectively). CONCLUSIONS: RT for MCC was associated with improved LRC and survival. RT appeared to be beneficial regardless of margin status.

LINAC-based stereotactic radiosurgery to the brain with concurrent vemurafenib for melanoma metastases.

While selective BRAF inhibitors have demonstrated improved outcomes in patients with metastatic BRAF V600E mutant melanoma, management of brain metastases prior to and during therapy presents challenges. Stereotactic radiosurgery (SRS) is an effective treatment for melanoma brain metastases, but there is limited safety and efficacy data on the use of SRS during BRAF therapy. An analysis was performed of patients with metastatic melanoma and brain metastases treated with SRS while on vemurafenib. MRI scans were reviewed post-SRS to evaluate local control (LC) as well as distant control. We identified 80 metastatic melanoma brain lesions treated in 24 patients. The median planning target volume was 0.28 cm(3) (range 0.05-4.19 cm(3)), and lesions were treated to a median dose of 24 Gy (range 15-24 Gy). The median follow up was 5.1 months (range 2-25.2 months). Eight (10 %) lesions showed progression at a median of 6.1 months (range 2-20.1 months) following SRS. Kaplan-Meier LC estimates at 6 and 12 months were 92 and 75 %, respectively. Fourteen (58 %) patients were noted to have distant brain failure at a median of 3.4 months (range 1.9-16.1 months) following treatment with SRS. Median overall (OS) from the date of SRS was 7.2 months (range 1.5-26.8 months) with a median of 11.9 months (range 1.5-28.5 months) since the date of brain metastases diagnosis. There was no evidence of increased toxicity with the combination of SRS and vemurafenib. SRS to brain metastases appears to be both safe and effective for patients treated concurrently with BRAF inhibitors.

Radiotherapy influences local control in patients with desmoplastic melanoma.

BACKGROUND: Desmoplastic melanoma may have a high risk of local recurrence after wide excision. The authors hypothesized that adjuvant radiotherapy (RT) would improve local control in patients with desmoplastic melanoma, resulting in at least a 10% absolute decrease in local recurrence rate. METHODS: A total of 277 patients from 1989 through 2010 who were treated for nonmetastatic desmoplastic melanoma by surgery with or without adjuvant RT were reviewed. Clinicopathologic and treatment variables were assessed with regard to their role in local control. RESULTS: A total of 113 patients (40.8%) received adjuvant RT. After a median follow-up of 43.1 months, adjuvant RT was found to be independently associated with improved local control on multivariable analysis (hazards ratio, 0.15; 95% confidence interval, 0.06-0.39 [P<.001]). Among 35 patients with positive resection margins, 14% who received RT developed a local recurrence versus 54% who did not (P=.004). In patients with negative resection margins, there was a trend (P=.09) toward improved local control with RT. In patients with negative resection margins and traditionally high-risk features, including a head and neck tumor location, a Breslow depth >4 mm, or a Clark level V tumor, RT was found to significantly improve local control (P< .05). The data from the current study would suggest that patients who would be good candidates for omitting RT included those with negative resection margins, a Breslow depth ≤ 4 mm, and either no perineural invasion present or a non-head and neck tumor location. CONCLUSIONS: RT for desmoplastic melanoma was independently associated with improved local control. Patients with positive resection margins or deeper tumors appeared to benefit the most from RT, whereas selected low-risk patients can safely omit RT.

Radiation-induced autophagy potentiates immunotherapy of cancer via up-regulation of mannose 6-phosphate receptor on tumor cells in mice.

There is a significant body of evidence demonstrating that radiation therapy (XRT) enhances the effect of immune therapy. However, the precise mechanisms by which XRT potentiates the immunotherapy of cancer remain elusive. Here, we report that XRT potentiates the effect of immune therapy via induction of autophagy and resultant trafficking of mannose-6-phopsphate receptor (MPR) to the cell surface. Irradiation of different tumor cells caused substantial up-regulation of MPR on the cell surface in vitro and in vivo. Down-regulation of MPR in tumor cells with shRNA completely abrogated the combined effect of XRT and immunotherapy (CTLA4 antibody) in B16F10-bearing mice without changes in the tumor-specific responses of T cells. Radiation-induced MPR up-regulation was the result of redistribution of the receptor to the cell surface. This effect was caused by autophagy with redirection of MPR to autophagosomes in a clathrin-dependent manner. In autophagosomes, MPR lost its natural ligands, which resulted in subsequent trafficking of empty receptor(s) back to the surface. Together, our data demonstrated a novel mechanism by which XRT can enhance the effect of immunotherapy and the molecular mechanism of this process.

Fractionated stereotactic radiotherapy to the post-operative cavity for radioresistant and radiosensitive brain metastases.

Following surgical resection for brain metastases, fractionated stereotactic radiotherapy (FSRT) has been used as an alternative to single dose treatment for large cavities and to reduce risks of late toxicity. The purpose of this study was to evaluate the outcomes of patients treated with FSRT to the post-operative bed for both radioresistant and radiosensitive brain metastases. Between December 2009 and May 2013 a total of 65 patients with newly diagnosed brain metastases were treated with resection followed by FSRT. Patients were treated to a total dose of 20-30 Gy in five fractions. Median planning target volume (PTV) was 16.88 cm(3) (range 4.87-128.43 cm(3)). The median follow-up for all patients was 8.5 months (range 1.1-28.6 months) with a median of 12.9 months for living patients. One and two year Kaplan-Meier estimates of local control were 87.0 and 70.0 %, respectively. Local control at 1 year was 85.6 and 88.0% for radioresistant and radiosensitive tumors, respectively (p = 0.44). A PTV ≥17 cm(3), was associated with local failure, HR 8.63 ((1.44-164.78); p = 0.02). One and two year distant control rates were 50.9 and 46.2%, respectively with six patients (9.2%) experiencing leptomeningeal disease. OS rates at 1 and 2 years were 65.2 and 47.5%, respectively. Survival was significantly associated with recursive partitioning analysis class (p = 0.001) and graded prognostic assessment score (p = 0.005). One case of radionecrosis was noted on follow-up imaging. FSRT in five fractions offers excellent local control in both radiosensitive and radioresistant tumors with minimal toxicity.

Myocardial matrix-polyethylene glycol hybrid hydrogels for tissue engineering.

Similar to other protein-based hydrogels, extracellular matrix (ECM) based hydrogels, derived from decellularized tissues, have a narrow range of mechanical properties and are rapidly degraded. These hydrogels contain natural cellular adhesion sites, form nanofibrous networks similar to native ECM, and are biodegradable. In this study, we expand the properties of these types of materials by incorporating poly(ethylene glycol) (PEG) into the ECM network. We use decellularized myocardial matrix as an example of a tissue specific ECM derived hydrogel. Myocardial matrix-PEG hybrids were synthesized by two different methods, cross-linking the proteins with an amine-reactive PEG-star and photo-induced radical polymerization of two different multi-armed PEG-acrylates. We show that both methods allow for conjugation of PEG to the myocardial matrix by gel electrophoresis and infrared spectroscopy. Scanning electron microscopy demonstrated that the hybrid materials still contain a nanofibrous network similar to unmodified myocardial matrix and that the fiber diameter is changed by the method of PEG incorporation and PEG molecular weight. PEG conjugation also decreased the rate of enzymatic degradation in vitro, and increased material stiffness. Hybrids synthesized with amine-reactive PEG had gelation rates of 30 min, similar to the unmodified myocardial matrix, and incorporation of PEG did not prevent cell adhesion and migration through the hydrogels, thus offering the possibility to have an injectable ECM hydrogel that degrades more slowly in vivo. The photo-polymerized radical systems gelled in 4 min upon irradiation, allowing 3D encapsulation and culture of cells, unlike the soft unmodified myocardial matrix. This work demonstrates that PEG incorporation into ECM-based hydrogels can expand material properties, thereby opening up new possibilities for in vitro and in vivo applications.

Loop Catalog: a comprehensive HiChIP database of human and mouse samples.

HiChIP enables cost-effective and high-resolution profiling of regulatory and structural loops. To leverage the increasing number of publicly available HiChIP datasets from diverse cell lines and primary cells, we developed the Loop Catalog (https://loopcatalog.lji.org), a web-based database featuring HiChIP loop calls for 1319 samples across 133 studies and 44 high-resolution Hi-C loop calls. We demonstrate its utility in interpreting fine-mapped GWAS variants (SNP-to-gene linking), in identifying enriched sequence motifs and motif pairs at loop anchors, and in network-level analysis of loops connecting regulatory elements (community detection). Our comprehensive catalog, spanning over 4M unique 5kb loops, along with the accompanying analysis modalities constitutes an important resource for studies in gene regulation and genome organization.

Desmoplastic melanoma: is there a role for sentinel lymph node biopsy?

BACKGROUND: The utility of sentinel lymph node biopsy (SLNB) for desmoplastic melanoma (DM) is debated. We describe a large single-institution experience with SLNB for DM to determine clinicopathologic factors predictive of SLN metastasis. METHODS: Retrospective review identified 205 patients with DM who underwent SLNB from 1992 to 2010. Clinicopathologic characteristics were correlated with SLN status and outcome. RESULTS: Median age was 66 years, and 69 % of patients were male. Median Breslow thickness was 3.7 mm. In 128 cases (62 %), histologic subtype data was available; 61 cases (47.7 %) were mixed and 67 cases (52.3 %) were pure DM. A positive SLN was found in 28 cases (13.7 %); 24.6 % of mixed and 9 % of pure DM had SLN metastases. Multivariable analysis demonstrated that after controlling for age, histologic subtype correlated with SLN status [odds ratio: 3.0 for mixed vs pure, 95 % confidence interval: 1.1-8.7; p < .05]. Completion lymph node dissection was performed in 24 of 28 positive SLN patients with 16.7 % of cases having additional nodal disease. After a median follow-up of 6.3 years, 38 patients developed recurrence and 61 patients died. Positive SLN patients had a significantly higher risk of melanoma-related death compared with negative SLN patients (p = .01). CONCLUSIONS: The overall risk for SLN metastasis for DM is 13.7 % and is significantly higher for mixed (24.6 %) compared with pure (9.0 %) DM. We believe that these rates are sufficient to justify consideration of SLNB for both histologic variants, especially since detection of SLN disease appears to predict a higher risk for melanoma-related death.