A New Computed Tomography-Based Measure that Provides Insight Into Hip Stability in Patients With Posterior Wall Acetabular Fractures.

OBJECTIVES: To describe the technique and results of a new sagittal plane computed tomography (CT)-based angular measure for predicting stability after posterior wall acetabular fractures (PWF). DESIGN: Retrospective review. SETTING: Academic Level II trauma center. PATIENT SELECTION CRITERIA: Fifty-eight consecutive patients with PWF (AO/OTA class 62A.1), 98% were high-energy injuries. INTERVENTION: A new sagittal CT measure of PWF based on the angle subtending the joint center, cranial and caudal fracture exits. OUTCOME MEASURES AND COMPARISONS: Hip incongruity or dislocation demonstrated using gold standard test, examination under anesthesia (EUA), or instability on static images. Prediction of hip instability using a sagittal CT angular measure based on cranial and caudal fracture exits was compared with previous axial CT measures suggestive of increased risk for instability including posterior wall size >50%, and those with cranial exit within 5.0 mm of the acetabular dome. RESULTS: There were 32 operative and 26 nonoperatively treated fractures. Thirty fractures were determined to be unstable, and 28 were stable after EUA. Measurements of >70 degrees using the sagittal CT angular measure predicted instability in 28 of 28 patients, and ≤70 degrees predicted stability in 30 of 30 patients (sensitivity 100% and specificity 100%). Prevalence of EUA confirmed instability for subgroups with PWF based on prior axial CT measures were as follows: ≥50% wall involvement (11/16; sensitivity 67% and specificity 60%; 95% CI, 45%-89%/45%-75%), fracture within 5.0 mm of dome (5/18; sensitivity 86% and specificity 73%; 95% CI, 71%-100%/59%-87%), fracture within 5.0 mm of dome and ≥50% involvement (1/9; sensitivity 89% and specificity 56%; 95% CI, 69%-100%/24%-88%). CONCLUSIONS: In a sample of 58 mostly high energy posterior wall fractures all having had an EUA, a new sagittal angular CT measurement of ≤70 degrees predicted hip stability and >70 degrees predicted instability with 100% sensitivity and specificity. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Long-Term Motor versus Sensory Lumbar Plexopathy After Lateral Lumbar Interbody Fusion: Single-Center Experience, Intraoperative Neuromonitoring Results, and Multivariate Analysis of Patient-Level Predictors.

BACKGROUND: Although lateral lumbar interbody fusion (LLIF) is an effective surgical option for lumbar arthrodesis, postoperative plexopathies are a common complication. We characterized post-LLIF plexopathies in a large cohort and analyzed potential risk factors for each. METHODS: A single-institutional cohort who underwent LLIF between May 2015 and December 2019 was retrospectively reviewed for postoperative lumbar plexopathies. Plexopathies were divided based on sensory and motor symptoms and duration, as well as by laterality relative to the surgical approach. We assessed these subgroups for associations with patient and surgical characteristics as well as psoas dimensions. We then evaluated risk of developing plexopathies after intraoperative neuromonitoring observations. RESULTS: A total of 127 patients were included. The overall rate of LLIF-induced sensory or motor lumbar plexopathy was 37.8% (48/127). Of all cases, 42 were ipsilateral to the surgical approach (33.1%); conversely, 6 patients developed contralateral plexopathies (4.7%). Most (31/48; 64.6%) resolved with a follow-up interval of 402 days in the plexopathy group. Of ipsilateral cases, 24 patients experienced persistent (>90 days) postoperative sensory symptoms (18.9%), whereas 20 experienced persistent weakness (15.7%). More levels fused predicted persistent sensory symptoms (odds ratio, 1.714 [1.246-2.359]; P = 0.0085), whereas surgical duration predicted persistent weakness (odds ratio, 1.004 [1.002-1.006]; P = 0.0382). Psoas anatomic variables were not significantly associated with plexopathy. Nonresolution of intraoperative evoked motor potential alerts was a significant risk factor for developing plexopathies (relative risk, 2.29 [1.17-4.45]). CONCLUSIONS: Post-LLIF plexopathies are common but usually resolve. Surgical complexity and unresolved neuromonitoring alerts are possible risk factors for persistent plexopathy.

Long-Term Efficacy and Safety of Superficial Radiation Therapy in Subjects With Nonmelanoma Skin Cancer: A Retrospective Registry Study

Background: Low-dose superficial radiation therapy (SRT) effectively treats nonmelanoma skin cancer (NMSC) without requiring invasive excision. SRT is especially safe and effective among the elderly who comprise most patients with basal cell and squamous cell carcinomas (BCCs and SCCs). Objective: To demonstrate the long-term safety and efficacy of SRT for treating NMSC with a new generation device. Methods: A retrospective chart review was performed at four clinical study sites. The study population included male and female patients (N=516) treated with SRT for NMSC (N=776) including BCCs (n=448) and SCCs (n=328) prior to January 2015 with long-term follow-up records. Results: The overall mean (SD) total treatment dosage was 4652.33 (366.34) cGy (range, 3636.6 to 5455 cGy) administered over a mean of 12.3 (1.85) sessions. The overall Kaplan-Meier survival probability estimate (95% CI) was 0.989 (0.980, 0.998) at 24 months, 0.989 (0.969, 1.000) at 60 months, and 0.989 (0.942, 1.000) at 85 months. There were six recurrences of BCCs (n=4) and SCCs (n=2). The most common adverse event was hypopigmentation. Limitations: Retrospective study design and some incomplete data. Conclusion: It is estimated that 98.9% of nonmelanoma skin cancers will not recur after 85 months following superficial radiation therapy. J Drugs Dermatol. 2020;19(2)163-168. doi:10.36849/JDD.2020.4647

Following molecular transitions with single residue spatial and millisecond time resolution.

"Footprinting" describes assays in which ligand binding or structure formation protects polymers such as nucleic acids and proteins from either cleavage or modification; footprinting allows the accessibility of individual residues to be mapped in solution. Equilibrium and time-dependent footprinting links site-specific structural information with thermodynamic and kinetic transitions, respectively. The hydroxyl radical (*OH) is a uniquely insightful footprinting probe by virtue of it being among the most reactive chemical oxidants; it reports the solvent accessibility of reactive sites on macromolecules with as fine as a single residue resolution. A novel method of millisecond time-resolved *OH footprinting is presented based on the Fenton reaction, Fe(II) + H(2)O(2) --> Fe(III) + *OH + OH(-). It is implemented using a standard three-syringe quench-flow mixer. The utility of this method is demonstrated by its application to the studies on RNA folding. Its applicability to a broad range of biological questions involving the function of DNA, RNA, and proteins is discussed.

Fast Fenton footprinting: a laboratory-based method for the time-resolved analysis of DNA, RNA and proteins.

'Footprinting' describes assays in which ligand binding or structure formation protects polymers such as nucleic acids and proteins from either cleavage or modification; footprinting allows the accessibility of individual residues to be mapped in solution. Equilibrium and time-dependent footprinting links site-specific structural information with thermodynamic and kinetic transitions. The hydroxyl radical (*OH) is a particularly valuable footprinting probe by virtue of it being among the most reactive of chemical oxidants; it reports the solvent accessibility of reactive sites on macromolecules with as fine as a single residue resolution. A novel method of millisecond time-resolved .OH footprinting has been developed based on the Fenton reaction, Fe(II) + H2O2 --> Fe(III) + *OH + OH-. This method can be implemented in laboratories using widely available three-syringe quench flow mixers and inexpensive reagents to study local changes in the solvent accessibility of DNA, RNA and proteins associated with their biological function.

51V magic angle spinning NMR spectroscopy of Keggin anions [PVnW12-nO40](3+n)-: effect of countercation and vanadium substitution on fine structure constants.

Vanadium environments in Keggin oxopolytungstates were characterized by (51)V solid-state MAS NMR spectroscopy. (C(4)H(9))(4)N(+)-, K(+)-, Cs(+)-, as well as mixed Na(+)/Cs(+)- salts of the mono-, di-, and trivanadium substituted oxotungstates, [VW(11)O(40)](4-), [V(2)W(10)O(40)](5-), and [V(3)W(9)O(40)](6-), have been prepared as microcrystalline and crystalline solids. Solid-state NMR spectra report on the local environment of the vanadium site in these Keggin ions via their anisotropic quadrupolar and chemical-shielding interactions. These (51)V fine structure constants in the solid state are determined by the number of vanadium atoms present in the oxoanion core. Surprisingly, the quadrupolar anisotropy tensors do not depend to any significant extent on the nature of the countercations. On the other hand, the chemical-shielding anisotropy tensors, as well as the isotropic chemical shifts, display large variations as a function of the cationic environment. This information can be used as a probe of the local cationic environment in the vanadium-substituted Keggin solids.

Periungual myxoid neurofibroma.

A 34-year-old woman presented with a slow growing nontender nodule on her left index finger that had been present for 2 years. The tumor was excised and was histologically determined to be a myxoid neurofibroma. We report this case because of the rarity of both the tumor and its periungual location and to provide a review of the literature.

Deoxygenation of Polynuclear Metal-Oxo Anions: Synthesis, Structure, and Reactivity of the Condensed Polyoxoanion [(C(4)H(9))(4)N](4)(NbW(5)O(18))(2)O.

The deoxygenation of the mixed-metal polyoxoanion [(C(4)H(9))(4)N](3)NbW(5)O(19) with benzoyl chloride in dichloromethane forms quantitatively the condensed polyoxanion [(C(4)H(9))(4)N](4)(NbW(5)O(18))(2)O, in which two polyoxoanion fragments are linked together by a Nb-O-Nb oxo bridge. The product is characterized by a strong IR band at 692 cm(-)(1) assigned to a Nb-O-Nb stretch and a broad single (93)Nb NMR resonance at 975 ppm. Partial hydrolysis of [(C(4)H(9))(4)N](4)(NbW(5)O(18))(2)O to NbW(5)O(19)O(3)(-) in wet acetonitrile was observed by IR and (17)O NMR spectroscopy. The reaction of [(C(4)H(9))(4)N](4)(NbW(5)O(18))(2)O with a variety of alcohols and phenol forms alkoxide-derivatized polyoxoanions [(C(4)H(9))(4)N](2)Nb(OR)W(5)O(18) (R = methyl, ethyl, isopropyl, cholesteryl, phenyl). The similarity of the IR spectra of these deriviatives suggests that functionalization occurs at the terminal NbO oxygen. A crystallographic study of [(C(4)H(9))(4)N](4)(NbW(5)O(18))(2)O revealed a crystallographically imposed linear Nb-O-Nb oxo bridge (Nb-O(bridge) = 1.887(3) Å) and a structure in which the terminal tungsten-oxo bonds on the adjoining polyoxoanion fragments are eclipsed. Crystal data: orthorhombic, Cmca; Z = 4, a = 15.817(2) Å, b = 17.870(2) Å, c = 35.058(2) Å; V = 9928.0(10) Å(3); R = 5.52%.