Citations

AbstractPurposeNumerous surgical techniques have been described for the treatment of peroneal nerve palsy after knee dislocation with less than optimal outcomes. The purpose of this article is to present a review of the literature including modern surgical treatment options for peroneal nerve palsy after knee dislocation.MethodReview of the current body of literature relevant to the topic was undertaken and summarized accordingly. Mechanism of injury, pathology and prognosis as well as current and novel treatment options are presented.ResultsNeurolysis and nerve grafting results are dependant on nerve graft length, with documented recovery rates of only 44% for nerve grafts longer than 6 cm. Posterior tibial tendon transfer procedures have had reasonable success in allowing patients to return to ambulation without assistive devices; however, dorsiflexion strength on the affected side has been reported at only 30% that of the normal contralateral side, and return to activities more strenuous than walking has not been reported. Future concepts including partial nerve transfer of a motor branch of the tibial nerve to the peroneal nerve have been described, but no outcome data is currently available.ConclusionPeroneal nerve palsy after knee dislocation leads to significant functional impairment. Prior treatment strategies utilized for restoration of dorsiflexion and peroneal nerve function have yielded overall poor results. Newer surgical techniques are being developed and clinical trials are under way to evaluate their effectiveness.

Without adequate safety measures, oral chemotherapy can lead to undetected dosing errors. The Mayo Clinic launched a project to ensure that all capecitabine and temozolomide prescriptions receive an independent double check.

Exosomes are small extracellular vesicles that are thought to participate in intercellular communication. Recent work from our laboratory suggests that, in normal and cystic liver, exosome-like vesicles accumulate in the lumen of intrahepatic bile ducts, presumably interacting with cholangiocyte cilia. However, direct evidence for exosome-ciliary interaction is limited and the physiological relevance of such interaction remains unknown. Thus, in this study, we tested the hypothesis that biliary exosomes are involved in intercellular communication by interacting with cholangiocyte cilia and inducing intracellular signaling and functional responses. Exosomes were isolated from rat bile by differential ultracentrifugation and characterized by scanning, transmission, and immunoelectron microscopy. The exosome-ciliary interaction and its effects on ERK1/2 signaling, expression of the microRNA, miR-15A, and cholangiocyte proliferation were studied on ciliated and deciliated cultured normal rat cholangiocytes. Our results show that bile contains vesicles identified as exosomes by their size, characteristic “saucer-shaped” morphology, and specific markers, CD63 and Tsg101. When NRCs were exposed to isolated biliary exosomes, the exosomes attached to cilia, inducing a decrease of the phosphorylated-to-total ERK1/2 ratio, an increase of miR-15A expression, and a decrease of cholangiocyte proliferation. All these effects of biliary exosomes were abolished by the pharmacological removal of cholangiocyte cilia. Our findings suggest that bile contains exosomes functioning as signaling nanovesicles and influencing intracellular regulatory mechanisms and cholangiocyte proliferation through interaction with primary cilia.

This paper concerns the ultrasonic characterization of air-saturated double-layered porous materials by solving the inverse problem using experimental reflected signals at normal incidence. The double-layered porous media consist of two slabs of homogeneous isotropic porous materials with a rigid frame. The ultrasonic propagation in double-layered porous material is modeled using a temporal model in which the inertial effects are described by the tortuosity. The viscous and thermal losses of the medium are described by two susceptibility kernels which depend on the viscous and thermal characteristic lengths. The sensitivity of porosity, tortuosity, and viscous characteristic length of each layer is studied showing their effect on the reflected interface waveforms. The inverse problem is solved numerically by the least-squares method. Five parameters are inverted: porosity and tortuosity of the two layers and the viscous characteristic length of the first layer. The minimization of the discrepancy between experimental and theoretical data is made in the time domain. The inverse problem is shown to be well posed and its solution to be unique. Experimental results for waves reflected by the interfaces of the double-layered porous material are given and compared with theoretical predictions.

AbstractPurposeThe purpose of this study was (1) to describe a staged protocol for management of the dislocated knee and (2) to describe clinical and functional outcomes for patients who received initial spanning external fixation as part of this protocol.MethodNine knees in 9 patients, consisting of 6 males and 3 females, mean age 30.4 (range 19–44) years with diagnosis or presumption of knee dislocation were treated with a protocol of stabilization with external fixator. Mean follow‐up was 24 (range 13–42) months. Indications for spanning external fixation included significant vascular injury, gross instability on examination with failure to maintain joint reduction, open knee dislocation, inability to tolerate mobilization in a brace. The standard protocol involved vascular examination including ankle‐brachial index, ligamentous examination (under anesthesia when applicable), stabilization with temporary joint spanning external fixator, thromboprophylaxis, reconstructive knee surgery, and standard rehabilitation.ResultsMean range of motion (ROM) was 97.4° (range 80°–150°, SD 20.75, median 127.5). Median IKDC score was 80 (range 30–95), and mean Lysholm score was 76.7 (range 46–95). Heterotopic ossification (HO) was noted in 4 knees (44%).ConclusionThe treatment algorithm utilized in this series for management of the dislocated knee demonstrated satisfactory clinical and functional outcomes. This staged protocol provides a management option for those patients who may be best served with initial spanning joint external fixation. Larger prospective studies are needed to fully understand the merit of staged protocols in this setting.

Context: Intermittent PTH treatment stimulates bone formation, but the mechanism(s) of this effect remain unclear. Sclerostin is an inhibitor of Wnt signaling, and animal studies have demonstrated that PTH suppresses sclerostin production. Objective: The objective of the study was to test whether intermittent PTH treatment of postmenopausal women alters circulating sclerostin levels. Design: Prospective study. Setting: The study was conducted at a clinical research unit. Participants and Interventions: Participants included 27 postmenopausal women treated with PTH (1-34) for 14 d and 28 control women. Main Outcome Measures: Serum sclerostin levels were measured. Results: Circulating sclerostin levels decreased significantly in the PTH-treated subjects, from (mean ± SEM) 551 ± 32 to 482 ± 31 pg/ml (−12.7%, P < 0.0001) but did not change in the control women (baseline, 559 ± 34 pg/ml; end point, 537 ± 40 pg/ml, P = 0.207; P = 0.017 for difference in changes between groups). Bone marrow plasma was obtained in a subset of the control and PTH-treated subjects (n = 19 each) at the end of the treatment period, and marrow plasma and peripheral serum sclerostin levels were significantly correlated (R = 0.64, P < 0.0001). Marrow plasma sclerostin levels were 24% lower in PTH-treated compared with control women, but perhaps due to the smaller sample size, this difference was not statistically significant (P = 0.173). Conclusions: Circulating sclerostin levels correlate with bone marrow plasma levels and are reduced by intermittent PTH therapy in postmenopausal women. Further studies are needed to assess the extent to which decreases in sclerostin production contribute to the anabolic skeletal response to PTH.

Paraneoplastic opsoclonus is well described in neuroblastoma. In the adult oncologic population, opsoclonus is seen usually within the context of opsoclonus-myoclonus ataxia and is associated most strongly with small-cell lung cancer. Patients with paraneoplastic opsoclonus are often seronegative. Patients with gynecologic malignancies are known to be predisposed to paraneoplastic syndromes; however, we describe the first case of paraneoplastic opsoclonus in association with endometrial cancer.