Retinal Nerve Fiber Layer Optical Texture Analysis: Detecting Axonal Fiber Bundle Defects in Patients with Ocular Hypertension.

PURPOSE: To apply retinal nerve fiber layer (RNFL) optical texture analysis (ROTA) to investigate the prevalence, patterns, and risk factors of RNFL defects in patients with ocular hypertension (OHT) who showed normal optic disc and RNFL configuration in clinical examination, normal RNFL thickness on OCT analysis, and normal visual field (VF) results. DESIGN: Cross-sectional study. PARTICIPANTS: Six hundred eyes of 306 patients with OHT. METHODS: All participants underwent clinical examination of the optic disc and RNFL, OCT RNFL imaging, and 24-2 standard automated perimetry. To detect RNFL defects, ROTA was applied. The risk score for glaucoma development was calculated according to the Ocular Hypertension Treatment Study and European Glaucoma Prevention Study (OHTS-EGPS) risk prediction model. Risk factors associated with RNFL defects were analyzed using multilevel logistic regression analysis. MAIN OUTCOME MEASURES: Prevalence of RNFL defects. RESULTS: The average intraocular pressure (IOP) measured from 3 separate visits within 6 months was 24.9 ± 1.8 mmHg for the eye with higher IOP and 23.7 ± 1.7 mmHg for the eye with lower IOP; the respective central corneal thicknesses were 568.7 ± 30.8 µm and 568.8 ± 31.2 µm. Of 306 patients with OHT, 10.8% (33 patients, 37 eyes) demonstrated RNFL defects in ROTA in at least 1 eye. Of the 37 eyes with RNFL defects, the superior arcuate bundle was the most frequently involved (62.2%), followed by the superior papillomacular bundle (27.0%) and the inferior papillomacular bundle (21.6%). Papillofoveal bundle defects were observed in 10.8% of eyes. The smallest RNFL defect spanned 0.0° along Bruch's membrane opening margin, whereas the widest RNFL defect extended over 29.3°. Age (years) (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.03-1.13), VF pattern standard deviation (decibels [dB]) (OR, 1.82; 95% CI, 1.01-3.29), cup volume (mm3) (OR, 1.24; 95% CI, 1.01-1.53), and the OHTS-EPGS risk score (OR, 1.04; 95% CI, 1.01-1.07) were associated with RNFL defects. CONCLUSIONS: A considerable proportion of patients with OHT who showed no signs of optic disc and RNFL thickness abnormalities on clinical and OCT examination exhibited RNFL defects on ROTA. Axonal fiber bundle defects on ROTA may represent the earliest discernible sign of glaucoma in the glaucoma continuum. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Socioeconomic and Survival Analysis of Radioembolization in Patients with Intrahepatic Cholangiocarcinoma: A Propensity Score-Adjusted Study.

PURPOSE: To determine whether transarterial radioembolization (TARE) is associated with longer survival of patients with intrahepatic cholangiocarcinoma (ICC) and whether access to TARE is influenced by socioeconomic factors. MATERIALS AND METHODS: Retrospective review of patients with ICC in the National Cancer Database from 2004 to 2018 was performed with Cox regression analysis to identify predictors of survival. Overall survival (OS) was estimated using the Kaplan-Meier method. Socioeconomic factors were compared between 2 groups using the Wilcoxon rank-sum test and χ2 test. Propensity score-matched cohorts were created between patients with ICC who did and did not undergo TARE. RESULTS: The number of patients receiving TARE for ICC increased over time from 1 in 2004 to 210 in 2018. Patients in the TARE group were more likely to be White (87.9% vs 84.3%; P = .012) and less likely to be Hispanic/Latino (7.7% vs 11.0%; P = .009). Fewer patients who underwent TARE were uninsured (0.9% vs 2.8%; P = .012). Older age, male sex, non-White race, higher tumor grade size, and stage, earlier year of diagnosis, lack of treatment with surgery or systemic therapy, and presence of lymphatic or vascular invasion exhibited significant associations with decreased survival (P < .05 for all). Patients who underwent TARE had longer survival in both unadjusted and adjusted cohorts, with an OS of 17.5 months (vs 7.2 months in the non-TARE group) after propensity matching. CONCLUSIONS: Patients with ICC who had undergone TARE experienced significantly longer survival than that experienced by those who had not after adjusting for measurable confounders. Significant socioeconomic disparities in access to TARE remain.

Retinal Nerve Fiber Layer Optical Texture Analysis: Involvement of the Papillomacular Bundle and Papillofoveal Bundle in Early Glaucoma.

PURPOSE: To apply retinal nerve fiber layer (RNFL) optical texture analysis (ROTA) in eyes with early glaucoma to investigate (1) the pattern of RNFL defects, (2) how often the papillomacular bundle and papillofoveal bundles are involved, and (3) the association between papillomacular and papillofoveal bundle defects and visual field (VF) sensitivity abnormalities. DESIGN: Cross-sectional study. PARTICIPANTS: Two hundred four eyes with early glaucoma (VF mean deviation, ≥ -6 dB) with RNFL defects from 171 consecutively enrolled patients with glaucoma. METHODS: All eyes underwent 24-2 VF testing and OCT for ROTA. The borders of RNFL defects were delineated from ROTA, and the involvement of the arcuate bundle, papillomacular bundle (i.e., bundles from the macula, excluding the fovea), and papillofoveal bundle (i.e., bundles from the fovea) was determined for each eye. Multilevel logistic regression analysis was applied to evaluate the structure-function association. MAIN OUTCOME MEASURES: Proportions of eyes with papillomacular or papillofoveal bundle defects. RESULTS: Of the 204 eyes, 71.6% and 17.2% demonstrated RNFL defects involving the papillomacular and papillofoveal bundles, respectively; 25.0% showed arcuate bundle defects without involvement of papillomacular or papillofoveal bundles. The pattern of RNFL defects was diverse; the most common was concomitant involvement of the inferior arcuate bundle and the inferior papillomacular bundle (20.6%). Papillomacular or papillofoveal bundle defects were not associated with VF defects (i.e., with ≥ 3 contiguous locations with abnormal VF sensitivity in the pattern deviation probability plot) in the corresponding hemifield, although VF sensitivity of any 1 of the central 4 VF locations of the 24-2 test, which were within the macula, was more likely to be abnormal (P < 0.05 in the pattern deviation probability plot; odds ratio, 12.5; 95% confidence interval, 7.0-22.5) when the VF stimulus was projected onto a papillomacular or papillofoveal bundle defect than that projected onto an intact papillomacular or papillofoveal bundle. CONCLUSIONS: Contrary to the conventional notion that the fovea and macula are not affected until the late stages of glaucoma, papillofoveal and papillomacular bundle defects were common in early glaucoma, and they were associated with central VF sensitivity loss at the corresponding VF test locations.

Geniculate Artery Embolization: Role in Knee Hemarthrosis and Osteoarthritis.

Roughly 37% of Americans 60 years of age and older experience chronic pain due to osteoarthritis (OA) of the knee. After conservative treatment (pharmacologic, physical therapy, and joint injections) fails, patients often require total knee arthroplasty to alleviate pain and regain knee function. Given the high economic burden of surgery paired with its invasive nature, many patients with this degenerative joint disease seek alternative treatment. Moreover, many patients with severe knee OA who also have comorbidities that preclude surgery-most often morbid obesity-are left without options. Geniculate artery embolization (GAE) is a minimally invasive intra-arterial intervention that was originally developed for the treatment of knee hemarthrosis that has recently been adapted for symptomatic knee OA. Through selective embolization of geniculate branches corresponding to the site of knee pain, GAE inhibits the neovascularity that contributes to the catabolic and inflammatory drive of OA. Preliminary trials over the past decade have demonstrated promising clinical results, including decreased pain and improved function and quality of life after treatment. Given such success, GAE provides another minimally invasive treatment option for knee OA to patients who feel reluctant to undergo or are ineligible for surgery. The authors review the radiographic manifestations and current standard of treatment of OA and hemarthrosis of the knee. Procedural technique, embolic selection, and clinical evidence for GAE in the treatment of OA and hemarthrosis of the knee are also explored. The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2021.

Application of the VORTEC Technique in Creating a Proximal Inflow Conduit in the Circumferentially-Calcified or "Lead-Pipe" Aorta.

A heavily calcified or "lead-pipe" aorta can present many challenges to any surgeon. There is higher risk of vessel wall rupture or disruption, distal embolization, and prolonged ischemia time of visceral organs due to longer clamp times. Hybrid revascularization techniques, which were originally described in visceral revascularization during complex aortic procedures, can be potentially utilized for lower extremity bypasses. These techniques, such as "VORTEC," are well-studied and have been shown to have similar patency rates as traditional bypass grafts with the added benefit of decreased ischemia time and lower levels of acute kidney injury and visceral organ ischemia. This allows VORTEC and other similar hybrid techniques to be utilized as options when traditional vessel control cannot be safely achieved during distal revascularization procedures, as we describe in our patient.

Wide-field Trend-based Progression Analysis of Combined Retinal Nerve Fiber Layer and Ganglion Cell Inner Plexiform Layer Thickness: A New Paradigm to Improve Glaucoma Progression Detection.

OBJECTIVE: Evaluation of glaucoma progression with OCT has been centered on the analysis of progressive retinal nerve fiber layer (RNFL) thinning over the parapapillary region and/or progressive ganglion cell inner plexiform layer (GCIPL) thinning over the macula. We investigated (1) whether combining the RNFL and GCIPL as a single layer (i.e., RNFL-GCIPL) for wide-field progression analysis outperforms wide-field progression analysis of the RNFL or the GCIPL, and (2) whether eyes with progressive RNFL-GCIPL thinning are at risk of visual field (VF) progression. DESIGN: Prospective, longitudinal study. PARTICIPANTS: A total of 440 eyes from 236 glaucoma patients; 98 eyes from 49 healthy individuals. METHODS: OCT RNFL/GCIPL/RNFL-GCIPL thickness and VF measurements were obtained at ∼4-month intervals for ≥3 years. Progressive changes of the RNFL/GCIPL/RNFL-GCIPL thicknesses were analyzed over a wide field (12×9 mm2) covering the parapapillary region and the macula with trend-based progression analysis (TPA) controlled at a false discovery rate of 5%. VF progression was determined by the Early Manifest Glaucoma Trial criteria. MAIN OUTCOME MEASURES: Proportions of eyes with progressive RNFL/GCIPL/RNFL-GCIPL thinning; hazard ratios (HRs) for development of VF progression. RESULTS: More eyes showed progressive RNFL-GCIPL thinning (127 eyes; 28.9%, 95% confidence interval [CI]: 23.9%-33.8%) than progressive RNFL thinning (74 eyes; 16.8%, 95% CI: 13.1%-20.6%) and progressive GCIPL thinning (26 eyes; 5.9%, 95% CI: 3.7%-8.1%) in the glaucoma group over the study follow-up. Progressive RNFL-GCIPL thinning was almost always detected before or simultaneously with progressive RNFL thinning or progressive GCIPL thinning. The specificity of TPA (estimated from the healthy group) for detection of progressive RNFL-GCIPL thinning, progressive RNFL thinning, and progressive GCIPL thinning was 83.7% (95% CI: 74.9%-92.4%), 94.9% (95% CI: 90.6%-99.2%), and 96.9% (95% CI: 93.5%-100.0%), respectively. Eyes with progressive RNFL-GCIPL thinning had a higher risk to develop possible (HR: 2.4, 95% CI: 1.2-5.0) or likely (HR: 4.6, 95% CI: 1.5-14.0) VF progression, with adjustment of covariates, compared with eyes without progressive RNFL-GCIPL thinning. CONCLUSIONS: Progression analysis of RNFL-GCIPL thickness reveals a significant portion of progressing eyes that neither progression analysis of RNFL thickness nor GCIPL thickness would identify. Wide-field progression analysis of RNFL-GCIPL thickness is effective to inform the risk of VF progression in glaucoma patients.

Adjuvant radiation followed by chemotherapy is associated with improved overall survival in endometrial cancer.

OBJECTIVE: Although multimodality therapy has been shown to improve outcomes for patients with high-risk endometrial carcinoma, optimal type and timing of adjuvant therapies is unknown. METHODS: Patients with stage I-IVA endometrial carcinoma diagnosed from 2004 to 2015, and treated with surgery, chemotherapy, and radiation were identified in the National Cancer Database. Adjuvant treatment was categorized as sequential radiation followed by chemotherapy (RT-CT), concurrent chemoradiation (CCRT, RT and CT started within 7 days), or sequential chemotherapy followed by radiation (CT-RT). Analysis for propensity score matched (PSM) cohorts comparing RT-CT to CCRT and CT-RT groups was additionally performed. RESULTS: A total of 17,070 patients were identified, including 12,402 (72.7%) treated with RT-CT, 2,153 (12.6%) with CCRT, and 2,515 (14.7%) with CT-RT. Median follow-up was 44.3 months. Five-year overall-survival (OS) by adjuvant treatment regimen was 77.3% (95% CI 76.4%-78.2%), 74.3% (95% CI 72.0%-76.3%), and 74.4% (95% CI 72.5%-76.3%), respectively (p < .001). When unmatched cohorts were stratified by stage, adjuvant RT-CT was associated with improved OS in stage I and III patients. A similar survival advantage associated with RT-CT was observed in PSM cohorts comparing RT-CT group to CCRT/CT-RT group (5-year OS 77.4% vs 74.2%, p = .001). However, the difference in OS was significant only among stage III patients (RT-CT 73.9% compared to CCRT/CT-RT 69.7%, p =.002). CONCLUSION: Our findings suggest survival benefit with adjuvant RT-CT compared to CT-RT or CCRT in patients undergoing trimodality therapy for endometrial cancer. This survival benefit may be limited to stage III patients.

Atherectomy with balloon angioplasty compared to balloon angioplasty alone for the treatment of chronic limb threatening ischemia: A national surgical quality improvement program database analysis.

OBJECTIVES: To compare perioperative outcomes related to atherectomy with percutaneous transluminal angioplasty versus percutaneous transluminal angioplasty alone for the treatment of lower extremity chronic limb threatening ischemia using a national patient database. METHODS: Patients with chronic limb threatening ischemia treated with atherectomy and percutaneous transluminal angioplasty or percutaneous transluminal angioplasty alone from 2011 to 2016 in the National Surgical Quality Improvement Program database were identified. Primary outcomes were major adverse limb events (30-day untreated loss of patency, major reintervention, major amputation) and major adverse cardiac events (cardiac arrest, composite outcome of myocardial infarction or stroke). Secondary outcomes included 30-day mortality, length of stay, and any unplanned readmission within 30 days. Multivariate regression analyses were performed to determine independent predictors of outcome. Propensity score matched cohort analysis was performed. A p-value <0.05 was considered statistically significant. Subgroup analyses of femoropopliteal and infrapopliteal interventions were performed. RESULTS: In total, 2636 (77.2%) patients were treated with percutaneous transluminal angioplasty and 778 (22.8%) were treated with atherectomy and percutaneous transluminal angioplasty. Multivariate analyses of the unadjusted cohort revealed no significant differences in major adverse cardiac events or major adverse limb events between the two groups (p-value >0.05). Subgroup analysis of femoropopliteal interventions demonstrated a significantly decreased likelihood of untreated loss of patency in 30 days in the atherectomy group compared to the percutaneous transluminal angioplasty group (1.1% vs. 2.7%, respectively; p-value = 0.034), which persisted on propensity score matched analysis (1.1% vs. 3.1%, respectively; p-value = 0.026). CONCLUSION: Atherectomy with balloon angioplasty of femoropopliteal disease provides a significant decrease in untreated loss of patency compared to balloon angioplasty alone.

Association of FK506 binding proteins with RyR channels - effect of CLIC2 binding on sub-conductance opening and FKBP binding.

Ryanodine receptor (RyR) Ca2+ channels are central to striated muscle function and influence signalling in neurons and other cell types. Beneficially low RyR activity and maximum conductance opening may be stabilised when RyRs bind to FK506 binding proteins (FKBPs) and destabilised by FKBP dissociation, with submaximal opening during RyR hyperactivity associated with myopathies and neurological disorders. However, the correlation with submaximal opening is debated and quantitative evidence is lacking. Here, we have measured altered FKBP binding to RyRs and submaximal activity with addition of wild-type (WT) CLIC2, an inhibitory RyR ligand, or its H101Q mutant that hyperactivates RyRs, which probably causes cardiac and intellectual abnormalities. The proportion of sub-conductance opening increases with WT and H101Q CLIC2 and is correlated with reduced FKBP-RyR association. The sub-conductance opening reduces RyR currents in the presence of WT CLIC2. In contrast, sub-conductance openings contribute to excess RyR 'leak' with H101Q CLIC2. There are significant FKBP and RyR isoform-specific actions of CLIC2, rapamycin and FK506 on FKBP-RyR association. The results show that FKBPs do influence RyR gating and would contribute to excess Ca2+ release in this CLIC2 RyR channelopathy.

Demographic and facility volume related outcomes in radiofrequency ablation for early-stage hepatocellular carcinoma.

BACKGROUND: To evaluate outcomes related to disparities in facility volume and patient demographics in patients with early-stage hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA). METHODS: This is a retrospective study of patients with stage I/II HCC treated with RFA in the National Cancer Database. Independent contributors to overall survival were determined with Cox regression analysis. The Kaplan-Meier method and log-rank analyses were used to estimate overall survival and compare survival curves. A propensity score matched cohort analysis was performed. P-values < 0.05 were considered statistically significant. RESULTS: In total, 2911 patients were included. Stage II disease (p-value = 0.006), increasing alpha fetoprotein (p-value = 0.007), and increasing bilirubin (p-value < 0.001) were associated with worse survival. Improved survival was seen in patients treated at high-volume centers (p-value = 0.004), which persisted following propensity score adjustment (p-value = 0.003). Asian race was associated with significantly improved survival (p-value < 0.001), while governmental insurance was associated with a significant decrease in survival (p-value < 0.001). CONCLUSION: Treatment at a high-volume center and Asian race were significantly associated with improved survival following RFA for early-stage HCC. Governmental insurance, increasing alpha fetoprotein, increasing bilirubin, and higher disease stage were significantly associated with worse survival.

A National Cancer Database Analysis of Radiofrequency Ablation versus Stereotactic Body Radiotherapy in Early-Stage Non-Small Cell Lung Cancer.

PURPOSE: To compare overall survival (OS) after radiofrequency (RF) ablation and stereotactic body radiotherapy (SBRT) at high-volume centers in patients with early-stage non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Cases in the National Cancer Database of stage 1a and 1b NSCLC treated with primary RF ablation or SBRT from 2004 to 2014 were included. Patients treated at low-volume centers, defined as facilities below the 95th percentile in volume of cases performed, were excluded. Outcomes measured include OS and rate of 30-day readmission. The Kaplan-Meier method was used to estimate OS. The log-rank test was used to compare survival curves. Propensity score matched cohort analysis was performed. P < .05 was considered statistically significant. RESULTS: The final cohort comprised 4,454 cases of SBRT and 335 cases of RF ablation. Estimated median survival and follow-up were 38.8 months and 42.0 months, respectively. Patients treated with RF ablation had significantly more comorbidities (P < .001) and higher risk for an unplanned readmission within 30 days (hazard ratio = 11.536; P < .001). No difference in OS for the unmatched groups was found on multivariate Cox regression analysis (P = .285). No difference was found in the matched groups with 1-, 3-, and 5-year OS of 85.5%, 54.3%, and 31.9% in the SBRT group vs 89.3%, 52.7%, and 27.1% in the RF ablation group (P = .835). CONCLUSIONS: No significant difference in OS was seen between patients with early-stage NSCLC treated with RF ablation and SBRT.

Patient and Facility Demographics Related Outcomes in Early-Stage Non-Small Cell Lung Cancer Treated with Radiofrequency Ablation: A National Cancer Database Analysis.

PURPOSE: To determine facility and patient demographics associated with survival in early-stage non-small cell lung cancer (NSCLC) treated with radiofrequency (RF) ablation. MATERIALS AND METHODS: The National Cancer Database was queried for cases of stage 1a NSCLC treated with RF ablation without chemotherapy or radiotherapy from 2004 to 2014. High-volume centers (HVCs) were defined as the top 95th percentile of facilities by number of procedures performed. Overall survival (OS) was estimated with the Kaplan-Meier method, and comparisons between survival curves were performed with the log-rank test. Propensity score-matched cohort analysis was performed. P values less than .05 were considered statistically significant. RESULTS: In the final cohort, 967 cases were included. Estimated median survival and follow-up were 33.1 and 62.5 months, respectively. Of 305 facilities, 15 were determined to be HVCs, treating 13 or more patients from 2004 to 2014. A total of 335 cases (34.6%) were treated at HVCs. On multivariate Cox regression analysis, treatment at an HVC was independently associated with improved OS (hazard ratio [HR] = 0.766; P = .006). After propensity score adjustment, 1-, 3-, and 5-year OS was 89.8%, 51.2%, and 27.7%, respectively, for patients treated at HVCs, compared to 85.2%, 41.5%, and 19.6%, respectively, for patients treated at non-HVCs (P = .015). Increasing age (HR = 1.012; P = .013) and higher T-classification (HR = 1.392; P < .001) were independently associated with worse OS. CONCLUSION: Patients with early-stage NSCLC treated with RF ablation at HVCs experienced a significant increase in OS, suggesting regionalization of lung cancer management as a means of improving outcomes.

Radiogenomics and IR.

Radiogenomics involves the integration of mineable data from imaging phenotypes with genomic and clinical data to establish predictive models using machine learning. As a noninvasive surrogate for a tumor's in vivo genetic profile, radiogenomics may potentially provide data for patient treatment stratification. Radiogenomics may also supersede the shortcomings associated with genomic research, such as the limited availability of high-quality tissue and restricted sampling of tumoral subpopulations. Interventional radiologists are well suited to circumvent these obstacles through advancements in image-guided tissue biopsies and intraprocedural imaging. Comprehensive understanding of the radiogenomic process is crucial for interventional radiologists to contribute to this evolving field.

The Anthracycline Metabolite Doxorubicinol Abolishes RyR2 Sensitivity to Physiological Changes in Luminal Ca2+ through an Interaction with Calsequestrin.

The chemotherapeutic anthracycline metabolite doxorubicinol (doxOL) has been shown to interact with and disrupt the function of the cardiac ryanodine receptor Ca2+ release channel (RyR2) in the sarcoplasmic reticulum (SR) membrane and the SR Ca2+ binding protein calsequestrin 2 (CSQ2). Normal increases in RyR2 activity in response to increasing diastolic SR [Ca2+] are influenced by CSQ2 and are disrupted in arrhythmic conditions. Therefore, we explored the action of doxOL on RyR2's response to changes in luminal [Ca2+] seen during diastole. DoxOL abolished the increase in RyR2 activity when luminal Ca2+ was increased from 0.1 to 1.5 mM. This was not due to RyR2 oxidation, but depended entirely on the presence of CSQ2 in the RyR2 complex. DoxOL binding to CSQ2 reduced both the Ca2+ binding capacity of CSQ2 (by 48%-58%) and its aggregation, and lowered CSQ2 association with the RyR2 complex by 67%-77%. Each of these effects on CSQ2, and the lost RyR2 response to changes in luminal [Ca2+], was duplicated by exposing native RyR2 channels to subphysiologic (≤1.0 µM) luminal [Ca2+]. We suggest that doxOL and low luminal Ca2+ both disrupt the CSQ2 polymer, and that the association of the monomeric protein with the RyR2 complex shifts the increase in RyR2 activity with increasing luminal [Ca2+] away from the physiologic [Ca2+] range. Subsequently, these changes may render the channel insensitive to changes of luminal Ca2+ that occur through the cardiac cycle. The altered interactions between CSQ2, triadin, and/or junctin and RyR2 may produce an arrhythmogenic substrate in anthracycline-induced cardiotoxicity.

Multiple actions of phi-LITX-Lw1a on ryanodine receptors reveal a functional link between scorpion DDH and ICK toxins.

We recently reported the isolation of a scorpion toxin named U1-liotoxin-Lw1a (U1-LITX-Lw1a) that adopts an unusual 3D fold termed the disulfide-directed hairpin (DDH) motif, which is the proposed evolutionary structural precursor of the three-disulfide-containing inhibitor cystine knot (ICK) motif found widely in animals and plants. Here we reveal that U1-LITX-Lw1a targets and activates the mammalian ryanodine receptor intracellular calcium release channel (RyR) with high (fM) potency and provides a functional link between DDH and ICK scorpion toxins. Moreover, U1-LITX-Lw1a, now described as ϕ-liotoxin-Lw1a (ϕ-LITX-Lw1a), has a similar mode of action on RyRs as scorpion calcines, although with significantly greater potency, inducing full channel openings at lower (fM) toxin concentrations whereas at higher pM concentrations increasing the frequency and duration of channel openings to a submaximal state. In addition, we show that the C-terminal residue of ϕ-LITX-Lw1a is crucial for the increase in full receptor openings but not for the increase in receptor subconductance opening, thereby supporting the two-binding-site hypothesis of scorpion toxins on RyRs. ϕ-LITX-Lw1a has potential both as a pharmacological tool and as a lead molecule for the treatment of human diseases that involve RyRs, such as malignant hyperthermia and polymorphic ventricular tachycardia.

Assessing the clinical utility of color Doppler ultrasound for ovarian torsion in the setting of a negative contrast-enhanced CT scan of the abdomen and pelvis.

PURPOSE: The purpose of this study is to evaluate the utility of color Doppler ultrasound (CDU) in the assessment of ovarian torsion following a negative contrast-enhanced computed tomography (CT) examination. METHODS: This is a retrospective study of women who presented to the ED with abdominal pain and received both a contrast-enhanced CT and CDU within a 24-h period. The abdominal/pelvic CT examinations were evaluated for findings specific to torsion, including ovarian size greater than 5 cm, the presence of free fluid, uterine deviation, fallopian tube thickening, ovarian fat stranding, smooth wall thickening, the presence of the "twisted pedicle" sign, and abnormal ovarian enhancement. The results were compared to the presence or absence of ovarian torsion on the concurrent US. RESULTS: The initial query yielded 834 cases among 789 women. Of those 834 cases, 283 cases in 261 women received both imaging modalities within a 24-h period. The CT examinations demonstrated 48 cases with an ovarian size greater than 5 cm. 84 cases showed the presence of free fluid. Three cases of fallopian tube thickening were identified. One case of smooth wall thickening and a "twisted pedicle" sign were noted. Fifteen cases demonstrated stranding of the peri-ovarian fat. Twenty nine cases showed abnormal ovarian enhancement. A total of 111 cases showed at least one positive finding. Fourteen positive cases were identified on the CDU studies. Of the 14 positive cases, 11 had ovarian size greater than 5 cm. Twelve cases demonstrated the presence of free fluid. There was no uterine deviation or smooth wall thickening. One twisted pedicle was noted. Seven cases showed peri-ovarian fat stranding. Ten cases showed abnormal enhancement. Abnormalities on CT were noted in all cases suspicious for ovarian torsion on CDU. No negative CT examinations were associated with a positive CDU. In this small sample size, the negative predictive value of a negative CT examination was 100%. CONCLUSION: A negative contrast-enhanced CT examination of the abdomen and pelvis is sufficient to rule out ovarian torsion. Therefore, there is no utility in the addition of CDU specifically to evaluate for ovarian torsion following a negative contrast-enhanced CT scan of the abdomen and pelvis.

Erdheim-Chester disease: an unusual presentation of an uncommon disease.

Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis with classic radiographic findings of patchy or diffuse osteosclerosis predominantly involving the long bones in a bilaterally symmetrical pattern. A 49-year-old woman presented with diffuse lymphadenopathy, painful skin lesions, and constitutional symptoms. Recent history was significant for a nontraumatic fracture of the tibia 3 weeks prior to admission. Physical examination and laboratory studies were notable for lower extremity pain and swelling, nodular lesions on the skin, and normocytic, normochromic anemia. Plain radiographs showed a lytic pattern of destruction with a superimposed fracture in the left proximal tibia. MRI showed focal bone marrow replacement extending from the subchondral bone to the tibial diaphysis. Excisional lymph node and skin biopsies of the lesions demonstrated a CD-68 positive, S-100 variable, and CD1a-negative histiocytic cell proliferation filling the dermis and completely replacing the sampled lymph node with an accompanying chronic inflammatory infiltrate and fibrosis, pathognomonic for ECD. We report an unusual case of ECD presenting initially as diffuse, painful lymphadenopathy, and subsequently demonstrating a lytic lesion of the tibia underlying a nontraumatic fracture.

The BKCa (slo) channel regulates the cardiac function of Drosophila.

The large conductance, calcium, and voltage-active potassium channels (BKCa) were originally discovered in Drosophila melanogaster as slowpoke (slo). They are extensively characterized in fly models as ion channels for their roles in neurological and muscular function, as well as aging. BKCa is known to modulate cardiac rhythm and is localized to the mitochondria. Activation of mitochondrial BKCa causes cardioprotection from ischemia-reperfusion injury, possibly via modulating mitochondrial function in adult animal models. However, the role of BKCa in cardiac function is not well-characterized, partially due to its localization to the plasma membrane as well as intracellular membranes and the wide array of cells present in mammalian hearts. Here we demonstrate for the first time a direct role for BKCa in cardiac function and cardioprotection from IR injury using the Drosophila model system. We have also discovered that the BKCa channel plays a role in the functioning of aging hearts. Our study establishes the presence of BKCa in the fly heart and ascertains its role in aging heart function.