The mouse as a model for the study of penile erection: moving towards a smaller animal

We evaluated erectile haemodynamics in mice and characterized the corpus cavernosum morphologically. Four-month-old male BALB/c mice and Sprague-Dawley rats were used. The following stimulation parameters were tested to achieve maximal erectile responses: voltage, 1-6 V; frequency, 6-24 Hz; pulse width, 1 msec; duration, 1 min (n = 7 per group). In a separate group of mice and rats (n = 10 per group), we measured systemic arterial pressure by use of either a 24-gauge angiocatheter or smaller calibre PE-10 tubing. Cavernous tissues from mice, rats or patients with psychogenic erectile dysfunction were stained for factor VIII, alpha-actin and Masson trichrome. Electrical stimulation of the cavernous nerve in mice produced voltage-dependent erectile responses of up to 5 V, with the highest response at a frequency of 12 Hz. The maximal intracavernous pressure recorded at this stimulation parameter was comparable with that in rats. A PE-10 catheter was more reliable for measuring systemic arterial pressure in mice than was a 24-gauge angiocatheter, and the values recorded were similar between mice and rats. The content of endothelial cells, smooth muscle cells and collagen was similar between mice and rats. However, the cavernous tissue of both animals contained lesser amounts of smooth muscle cells and greater amounts of collagen than that of humans (p < 0.01). These results suggest that the mouse is a useful and technically feasible model for the study of penile erection and has functional and structural properties similar to those of rats.     

Technique and early experience with posterior arthroscopic subtalar arthrodesis

BACKGROUND: Subtalar arthrodesis is a reliable procedure for pain relief and improved function in patients with isolated subtalar arthritis. Arthroscopic subtalar arthrodesis (ASTA) was designed to improve upon traditional methods by using a minimally invasive technique. However, posterior arthroscopic subtalar arthrodesis (PASTA) has not been described. The purpose of the present study was to investigate the early results of PASTA. METHODS: A retrospective review of 11 feet in 10 patients (one bilateral) that had PASTA was conducted. Inclusion criteria were isolated subtalar arthritis with no or minimal deformity and no significant bone loss. Exclusion criteria included patients requiring adjunctive open procedures or who had significant deformity. The technique involved prone positioning, two posterolateral portals and one posteromedial portal, posterior talocalcaneal facet debridement, percutaneous cancellous allografting and internal screw fixation. Outcome measures included patient satisfaction, the modified American Orthopaedic Foot and Ankle Society (AOFAS) score, union rate, time to union, and postoperative complications. RESULTS: All patients were discharged the day of surgery or stayed one night in the hospital. Eight patients were very satisfied, one satisfied, and one patient not satisfied with the results of their surgery. The average modified AOFAS score (maximum 94 points) improved from 36 points preoperatively to 86 points postoperatively. Ten joints fused by 10 weeks postoperatively, and one patient developed a nonunion. No other postoperative complications occurred. CONCLUSIONS: For surgeons familiar with posterior ankle or subtalar arthroscopy, PASTA offers superior exposure of the posterior talocalcaneal facet, high patient satisfaction, an excellent fusion rate, and less postoperative morbidity for patients with subtalar arthritis.     

Metastatic Disease to the Clivus Mimicking Clival Chordomas

Objectives/Hypothesis A comprehensive review of the literature of clival metastases and presentation of two additional cases.Study Design Literature review and report of two cases.Methods A literature review of the MEDLINE database (1950 to January 19, 2013) was performed to identify all cases of patients with metastatic disease to the clivus. Additionally, two novel cases are presented.Results In total, 47 cases were identified in the literature, including the two cases presented in this study. Metastatic disease to the clivus is the initial presenting symptom of the primary malignancy in 36% (13/36) of the cases. When there was a history of malignancy, the median interval of time to clival metastases was 24 months (range 1 to 172 months). Clinical symptoms manifested often as cranial neuropathies, with at least abducens palsies as the initial presenting symptom in 61.9% (26/42) of patients. Tumor pathology was diverse, but several pathologies were seen more commonly: prostate carcinoma (18.1%, 9/47), hepatocellular carcinoma (10.6%, 5/47), and thyroid follicular carcinoma (8.5%, 4/47).Conclusion Although clival metastases are extremely rare, they are an important part of the differential of clival masses as they can be the presenting symptom of distant malignancy.Level of Evidence 4.     

Attempted treatment of factor H deficiency by liver transplantation

Complement factor H (FH) deficiency is one of the causes of atypical hemolytic uremic syndrome (HUS). Most patients with FH deficiency associated HUS progress to end-stage renal disease despite plasma therapy. Moreover, the disease invariably recurs in the graft kidney and causes graft failure. We confirmed FH deficiency in a 30-month-old boy with recurrent HUS of 2 years duration, and attempted an auxiliary partial orthotopic liver transplantation (APOLT) to overcome the sustained intractable dependency on plasma therapy. APOLT restored the plasma FH level, without HUS recurrence, for 7 months. However, thereafter he suffered from serious infectious complications associated with immunosuppression and finally died 11 months after APOLT. In conclusion, although APOLT showed clinical and laboratory improvement for some period in this patient, the final fatal outcome suggests that liver transplantation should be cautiously applied to patients with HUS associated with FH deficiency.     

Balloon dilation of intrahepatic biliary strictures for percutaneous extraction of residual intrahepatic stones

Intrahepatic ductal strictures in cholangiohepatitis present an obstacle to successful removal of retained ductal stones via T-tube tracts. We studied the effectiveness of stricture dilatation for stone removal. Fifteen patients with intrahepatic gallstones retained behind strictures underwent balloon dilatation of their strictures to allow stone extraction. All had prior surgical T-tube placement allowing percutaneous access. Balloon dilatation was successful in reducing or eliminating strictures in 86.7% (13 of 15 patients), and complete stone extraction after the successful dilatation was possible in 76.9% (10 of 13 patients). The reasons for failure were impacted stones and acute ductal angulation which prevented passage of catheters. It is concluded that balloon dilatation of intrahepatic biliary strictures is an effective adjunct for extraction of intrahepatic biliary calculi associated with recurrent pyogenic cholangiohepatitis.     

Neuronal tumors of the central nervous system: radiologic findings and pathologic correlation.

Pure neuronal and mixed neuronal-glial tumors of the central nervous system are uncommon but fascinating because they are less aggressive than the more common glial tumors and their prognosis is excellent. Neurologic manifestations are varied and include seizures, symptoms of increased intracranial pressure, and neurologic deficits according to tumor location. Many neuronal tumors of the central nervous system demonstrate characteristic radiologic findings. At magnetic resonance (MR) imaging, gangliocytomas demonstrate low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and frequent enhancement on gadolinium-enhanced T1-weighted images. Characteristic MR imaging findings of Lhermitte-Duclos disease are a nonenhancing mass in a cerebellar hemisphere with a striated pattern. Central neurocytomas are typically located in the lateral ventricles near the foramen of Monro with a characteristic attachment to the septum pellucidum. Ganglioneurocytoma is a rare variant of central neurocytoma that is characterized by differentiation toward ganglion cells. In ganglioglioma, a well-defined cystic mass with a solid mural nodule is typically seen. Extension of enhancement to the leptomeninges is characteristic of desmoplastic infantile ganglioglioma and correlates with the firm dural attachment of the solid component. Dysembryoplastic neuroepithelial tumor has a well-demarcated, multilobulated or gyriform appearance.