Communication: Chemisorption of muonium on gold nanoparticles: A sensitive new probe of surface magnetism and reactivity.

Chemisorption of muonium onto the surface of gold nanoparticles has been observed. Muonium (µ+e-), a light hydrogen-like atom, reacts chemically with uncapped 7 nm gold nanoparticles embedded in mesoporous silica (SBA-15) with a strong temperature-dependent rate. The addition rate is fast enough to allow coherent spin transfer into a diamagnetic muon state on the nanoparticle surface. The muon is well established as a sensitive probe of static or slowly fluctuating magnetic fields in bulk matter. These results represent the first muon spin rotation signal on a nanoparticle surface or any metallic surface. Only weak magnetic effects are seen on the surface of these Au nanoparticles consistent with Pauli paramagnetism.

The diagnostic conundrum and liver transplantation outcome for combined hepatocellular-cholangiocarcinoma.

Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare primary liver malignancy with mixed hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) histological features. It is almost impossible to obtain an accurate, preoperative noninvasive diagnosis of cHCC-CC with tumor markers or cross-sectional abdominal imaging due to the mixed histological features. Despite these difficulties, accurate cHCC-CC diagnosis remains an important goal with prognostic significance. In our study, we retrospectively reviewed the tumor markers: AFP and CA 19-9, and cross-sectional liver imaging, in light of liver explant findings, to identify and characterize cHCC-CC features followed by liver transplantation (LT) outcome analysis. The results from this 12 patient cohort failed to identify characteristic features for cHCC-CC. None of the imaging features helped to identify the cHCC-CC tumor and they mimicked either HCC or CC, depending on the degree of glandular differentiation expressed histologically. In our cHCC-CC LT recipients, the 1-, 3- and 5-year cumulative survival probabilities were 79%, 66% and 16%, respectively with a 5-year survival comparable to or better than LT for intrahepatic CC but poorer than LT for HCC following the Milan criteria. Conceivably explained by its cholangiocarcinoma component the LT outcome for this rare and hard to diagnose tumor appears poor.

Benign metastasizing leiomyoma responsive to megestrol: case report and review of the literature.

Benign metastasizing leiomyoma (BML) is an unusual condition typically treated by surgical resection and hormonal therapy. A 37-year-old woman presented with dyspnea 6 years after uterine myomectomy. Computed tomographic scans showed pelvic and right-sided lung masses. Total abdominal hysterectomy and right salpingo-oophorectomy revealed only leiomyomas and benign ovarian cysts. Thoracotomy revealed multiple nodules consistent with leiomyomas. Estrogen and progesterone receptors on lung and uterine tissue were positive. A 21- x 18-mm residual area of neoplasm in the lung completely resolved 3 months after treatment with megestrol. The patient remains free of disease 3 years after lung resection. We present a rare case of BML in which the lung neoplasm responded to megestrol alone in the setting of intact ovarian function.