Peking Union Medical College Hospital

Understanding biological processes requires spatiotemporal mapping of proliferative and transcriptional dynamics. Current spatial transcriptomics methods capture only protein-coding transcripts and static snapshots, obscuring non-coding RNAs (ncRNAs) and dynamic events. We developed SPTEdU-seq, integrating spatial total transcriptomics with 5-ethynyl-2'-deoxyuridine tracking to co-profile gene expression and proliferation dynamics. SPTEdU-seq demonstrates ultrahigh sensitivity for coding and non-coding transcripts and for splicing isoforms, with single-molecule probe design eliminating optical imaging. Applied to developing and adult mouse brains, it revealed spatial lncRNA patterns, reconstructed developmental trajectories, and enabled spatiotemporal lineage tracing. In murine ischemic stroke, it mapped regeneration dynamics and identified an Igfbp5+ astrocyte subtype within a pro-repair niche. In mouse and human renal tumors, it uncovered tumor-associated splicing and detected diagnostic 3p loss. By profiling newborn and resident cells in intact microenvironments, it unveiled previously inaccessible interaction networks. SPTEdU-seq thus establishes a powerful framework for investigating cell fate dynamics in regeneration, development, and cancer.

Retroauricular hyaluronic acid (HA) injection can enhance the cranio-auricular angle, thereby reducing perceived facial width and enhancing aesthetic appeal. Although this is generally a safe procedure, acute facial nerve paralysis is a rare but devastating complication. The aim of this study is to characterize the MRI features of acute facial paralysis following retroauricular HA injection, including manifestations of nerve injury and the distribution of the injected material, and to infer the potential etiology of the facial paralysis based on imaging findings. 15 patients presenting with acute complete unilateral facial paralysis following retroauricular HA filler injection between December 1, 2023, and August 10, 2025 were identified. No perceivable improvement was seen despite non-surgical interventions for 2 weeks. MRI using a 3.0-T scanner was conducted to acquire gadolinium-enhanced T1-weighted and T2-weighted images. Each segment of the facial nerve was evaluated, and the diffusion range of the HA injection was observed by examining the contralateral side. MRI demonstrated significant enhancement of the facial nerve on the affected side compared to the unaffected side in the tympanic (P = 0.006), mastoid (P = 0.004), and parotid segments (P < 0.001) on contrast-enhanced T1-weighted images. Additionally, the HA filler exhibited extensive diffusion (46.7 ± 12.2 mm horizontally, 53.1 ± 12.2 mm vertically) and infiltrating adjacent tissue spaces. This group of patients showed widespread distribution of HA beyond the injection site. Additionally, persistent facial nerve edema and enhancement were mainly localized to the tympanic segment and its distal end of the facial nerve, indicating a possible need for facial nerve decompression in this cohort. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Early recognition of postpartum nerve injury is critical for timely intervention and recovery. However, diagnosis is challenging because deficits may mimic residual epidural anesthesia, nerve root injury, or epidural hematoma. Anesthesiologists, often first consulted, are pivotal in early evaluation and diagnosis. Figure 1 shows fat-suppressed T2-weighted pelvic magnetic resonance imaging obtained on postpartum day 7 from a 35-yr-old primiparous woman who reported difficulty lifting her right leg 1 day after vaginal delivery of a 2,670-g infant at 37 + 6 weeks under uneventful epidural labor analgesia (first stage, 12 h; second stage, 1.5 h with mediolateral episiotomy). This image demonstrates T2 hyperintensity in the right pectineus with normal contralateral signal—findings consistent with acute denervation edema and early peripheral neuropathy. Focused examination on postpartum day 1 revealed right hip flexion weakness (3/5) and unexpected adduction weakness (3/5), impairing leg crossing. Reflexes and sensation, including assessment of the obturator nerve’s medial thigh territory, were intact (Supplemental Digital Content fig. S1, https://links.lww.com/ALN/E356). Given that the pectineus may receive obturator nerve innervation, the imaging findings aligned with the adduction weakness and raised suspicion for obturator neuropathy, later confirmed by needle electromyography at 6 weeks, showing spontaneous activity in the right adductor magnus. With conservative management, hip flexion recovered from 4/5 at 1 week to 5/5 by 2 months, and adduction progressed from 4/5 at 1 month to full recovery by 3 months (Supplemental Digital Content video S1, https://links.lww.com/ALN/E357).Fig. 1.: Axial (A) and coronal (B) fat-suppressed T2-weighted fast spin echo pelvic magnetic resonance imaging obtained on postpartum day 7. Yellow arrows indicate increased T2 signal intensity in the right pectineus, with normal signal on the contralateral side (white arrows), consistent with early denervation changes.Electrodiagnostic testing is critical for evaluating peripheral nerve injury but limited within the first 1 to 2 weeks, as denervation signs typically appear 10 to 28 days after injury.1 In contrast, magnetic resonance imaging can detect muscle denervation as early as 24 h,2 is readily available, and visualizes surrounding structures to promptly exclude compressive lesions, making it a valuable tool for early diagnosis and management. Postpartum obturator neuropathy is rare, often due to fetal head or positional compression.3 Anesthesiologists should begin evaluation with a detailed peripartum history and a focused neurologic examination, carefully testing hip adduction, as subtle or compensated deficits may aid localization. Serial assessments clarify symptom evolution, guiding to the underlying cause. If deficits persist or worsen, then early magnetic resonance imaging is essential for differential diagnosis and timely rehabilitation. Competing Interests The authors declare no competing interests. Supplemental Digital Content Supplemental Figure 1. Schematic of medial thigh sensory innervation, https://links.lww.com/ALN/E356 Supplemental Video S1. Serial assessment of right lower limb function over the first 8 weeks postpartum, https://links.lww.com/ALN/E357