Cytopathology and ultrastructure identification of primary hepatic acinar cell carcinoma: Case report.

INTRODUCTION: A primary acinar cell carcinoma (ACC) of the liver was incidentally diagnosed in a clinically asymptomatic 80-year-old man. This study aimed to delineate critical diagnostic characteristics of an ACC originating uniquely from the liver to improve its future identification. PRESENTATION OF CASE: Enhanced MRI revealed a heterogenous, cystic 7.7 × 11.1 × 10.4 cm tumour occupying hepatic segments II and III. The mass demonstrated mild diffuse enhancement in hepatic arterial phase with minimal portal venous washout in a liver without cirrhotic features. A central stellate T2-hyperintense necrotic scar and outer capsule were apparent. No primary lesion or metastasis outside the liver was discernable. Post-left hepatic lobectomy, the tumour immunophenotype was atypical for presumptive diagnoses of hepatocellular carcinoma (HCC) or cholangiocarcinoma. Extensive morphologic workup on electron microscopy definitively diagnosed primary hepatic ACC by establishing presence of secretory zymogen-like granules, intracytoplasmic microvilli and acinar cell differentiation. Cytopathology revealed cellular lumen expressing PAS-positive diastase-resistant granular cytoplasmic contents. DISCUSSION: This case showcased the novel utility of electron microscopy that was crucial in yielding the definitive diagnosis. The previous literature on hepatic ACC was compiled here in context of the present case. The mechanism of hepatic acinar cell localization was also discussed. CONCLUSION: Primary hepatic ACC may easily be confused for other lesions due to nonspecific imaging patterns. Specifically, the presence of a central scar without risk factors for HCC can favour a diagnosis of benign entities such as focal nodular hyperplasia (FNH). Electron microscopy presents an important tool to identify primary hepatic ACC and may improve future patient outcomes.

Robotic TMS mapping of motor cortex in the developing brain.

BACKGROUND: The human motor cortex can be mapped safely and painlessly with transcranial magnetic stimulation (TMS) to explore neurophysiology in health and disease. Human error likely contributes to heterogeneity of such TMS measures. Here, we aimed to use recently pioneered robotic TMS technology to develop an efficient, reproducible protocol to characterize cortical motor maps in a pediatric population. NEW METHOD: Magnetic resonance imaging was performed on 12 typically developing children and brain reconstructions were paired with the robotic TMS system. The system automatically aligned the TMS coil to target sites in 3 dimensions with near-perfect coil orientation and real-time head motion correction. Motor maps of 4 forelimb muscles were derived bilaterally by delivering single-pulse TMS at predefined, uniformly spaced trajectories across a 10 × 10 grid (7 mm spacing) customized to the participant's MRI. RESULTS: Procedures were well tolerated with no adverse events. Two male, eight-year-old participants had high resting motor thresholds that precluded mapping. The mean hotspot coordinate and centre of gravity coordinate were determined in each hemisphere for four forelimb muscles bilaterally. Average mapping time was 14.25 min per hemisphere. COMPARISON WITH EXISTING METHODS: Traditional manual TMS methods of motor mapping are time intensive, technically challenging, prone to human error, and arduous for use in pediatrics. This novel TMS robot approach facilitates improved efficiency, tolerability, and precision in derived, high-fidelity motor maps. CONCLUSIONS: Robotic TMS opens new avenues to explore motor map neurophysiology and its influence on developmental plasticity and therapeutic neuromodulation. Our findings provide evidence that TMS robotic motor mapping is feasible in young participants.

Spin-transfer torque generated by a topological insulator.

Magnetic devices are a leading contender for the implementation of memory and logic technologies that are non-volatile, that can scale to high density and high speed, and that do not wear out. However, widespread application of magnetic memory and logic devices will require the development of efficient mechanisms for reorienting their magnetization using the least possible current and power. There has been considerable recent progress in this effort; in particular, it has been discovered that spin-orbit interactions in heavy-metal/ferromagnet bilayers can produce strong current-driven torques on the magnetic layer, via the spin Hall effect in the heavy metal or the Rashba-Edelstein effect in the ferromagnet. In the search for materials to provide even more efficient spin-orbit-induced torques, some proposals have suggested topological insulators, which possess a surface state in which the effects of spin-orbit coupling are maximal in the sense that an electron's spin orientation is fixed relative to its propagation direction. Here we report experiments showing that charge current flowing in-plane in a thin film of the topological insulator bismuth selenide (Bi2Se3) at room temperature can indeed exert a strong spin-transfer torque on an adjacent ferromagnetic permalloy (Ni81Fe19) thin film, with a direction consistent with that expected from the topological surface state. We find that the strength of the torque per unit charge current density in Bi2Se3 is greater than for any source of spin-transfer torque measured so far, even for non-ideal topological insulator films in which the surface states coexist with bulk conduction. Our data suggest that topological insulators could enable very efficient electrical manipulation of magnetic materials at room temperature, for memory and logic applications.

Complications of combined intraoperative radiation (IORT) and external radiation (ERT) of the upper abdomen: an experimental model.

An experimental model in the rabbit is presented which is suitable for analysis of clinically relevant, early side-effects of combined upper abdominal IORT and ERT. Fractionated ERT alone given through an upper abdominal a.-p. field including the entire stomach caused gastric ulcerations within < or = 58 days. Latent times decreased with increasing dose and the ED50 for occurrence of ulcers was 39 +/- 3.3 Gy. Single doses of IORT of 20-40 Gy alone administered through a 2-cm diameter field localized on the coeliac axis and carefully excluding any intestinal mucosa caused neither gastric ulcerations nor other clinical symptoms. When ERT with 40 Gy was preceded by IORT with 20-40 Gy or by sham IORT, 13 out of 15 animals developed ulcers after latent times which in a life-table analysis were shown to be significantly shorter than after ERT alone. However, a statistically significant IORT dose-dependence of latent time or incidence of ulcers could not be demonstrated in the present experiment. The most significant histological changes were observed in the areas of gastric ulcers. Already during ERT, the mucosal epithelium was depleted and regenerative activity was evident in spite of ongoing fractionated irradiation. However, profound irregularities in glandular structure and distribution, as well as number of proliferating epithelial cells were still present in healed ulcers at 80 days. In summary, IORT to the coeliac artery did precipitate the development of gastric ulcers induced by subsequent ERT. On the one hand, the data indicate that the surgical procedure of IORT did contribute to this effect. On the other hand, IORT to the coeliac artery could cause transient, functional alterations in blood supply to the depending organs, i.e. the stomach, and could thus precipitate the development of radiation-induced ulcers.

[Percutaneous drainage treatment of abscess and fluid retention following abdominal surgery]. / Percutane Drainagebehandlung von Abscessen und liquiden Retentionen nach abdominellen Eingriffen.

61 patients with abdominal abscesses and fluid collections as a postoperative complication underwent percutaneous drainage. 60 abscesses, 11 haematomas, 3 steril seromas and 3 bile collections were drained. The fluid collections were associated with biliary or enteric fistulae in 16 cases. The percutaneous drainage was successful in 69%, additional surgery was required in 15%. The overall mortality rate was 13%. Reasons for drainage failure were infected clots, phlegmonic abscesses and pancreas involvement of the abscesses.