Direct Drug Transport from the Rat Nasal Cavity to the Cerebrospinal Fluid: the Relation to the Molecular Weight of Drugs

To clarify the relationship between the direct transport from the rat nasal cavity to the cerebrospinal fluid (CSF) and the molecular weight of the drug, the transport of fluorescein isothiocyanate-labelled dextran (FD) with various molecular weights was investigated. FDs (average molecular weights 4400 (FD4); 9400 (FD10); 18 900 (FD20); 40 500 Da (FD40)) were administered nasally or intravenously to rats, and the concentrations in the plasma and the CSF were measured and compared. None of the FDs were detected in the CSF after intravenous administration. However, FD4, FD10 and FD20 were observed to appear in the CSF after nasal administration, whereas the concentration in the plasma was much lower than that after intravenous administration. FD40 was not detected even after nasal administration. In addition, the concentration of these FDs in the CSF decreased with the increase in the molecular weight of FDs. These findings show that drugs with a molecular weight up to at least 20 000 Da can be directly transported from the nasal cavity to the CSF and that the transport of FDs to the CSF is dependent on their molecular weights.     

Retrosigmoid Approach in the Supine Position Using ORBEYE: A Consecutive Series of 14 Cases

One of the merits of recently introduced exoscopes, including ORBEYE, is that they are superior to a conventional microscope in terms of ergonomic features. Taking advantage of it, the retrosigmoid approach can be performed in the supine position using ORBEYE. We report a consecutive series of 14 operations through the retrosigmoid approach in the supine position using ORBEYE. Fourteen consecutive patients who underwent surgery through the retrosigmoid approach for cerebellopontine (CP) angle lesions in the supine position using ORBEYE were targeted, and surgical outcomes and complications were examined. We evaluated the posture of the operator and the surgical field during this approach compared with those using a conventional microscope. In all 14 cases, all operative procedures were accomplished only using the ORBEYE. There were no operative complications due to this approach. Using ORBEYE, even when the angle of the operative visual axis was horizontal, the operators could manipulate in a comfortable posture. They were not forced to be in an uncomfortable posture that extended their arms, as is often the case with a conventional microscope. Therefore, they could use shorter surgical instruments. As the cerebellum shifted downward with gravity even using slight retraction during this approach, the working space of the surgical field was easily secured. Through this approach, the operators can perform stable microsurgery of CP angle lesions in a comfortable posture. This approach can reduce the burden on the operator and the patient, leading to a refined surgical procedure.     

Primary solitary intracranial melanoma in the sylvian fissure: MR demonstration

European Radiology - We present a rare case of a primary intracranial melanoma originating from leptomeningeal melanoblasts in the sylvian fissure. The mass appeared hyperintense on T1-weighted MR...     

Infection-induced urethral defect treated by urethral reconstruction with a radial forearm flap

Abstract A 47-year-old man was admitted with the chief complaint of a urethral defect. An approximately 17-cm defect of the urethra seemed to have been occurred by the infection of implanted foreign bodies in the penile skin. Reconstruction of the urethra and the ventral skin was performed with a free radial forearm flap. A fistula formed at the proximal anastomosis after the operation, but was controlled conservatively. Urethral stricture at the proximal anastomosis subsequently developed. A urethral stent made of shape memory alloy was placed with the preservation of voiding function.     

Periventricular intraparenchymal schwannoma

A 60-year-old male presented with a rare case of periventricular schwannoma. Imaging studies revealed a partially calcified, well-enhanced tumor in the periventricular area of the left frontal horn. The preoperative diagnosis was low grade glioma, but postoperative pathological findings revealed that the tumor was schwannoma. Most intraparenchymal schwannomas are benign, so total extirpation is usually curative. However, this uncommon neoplasm is difficult to distinguish from mimics, especially low grade gliomas, with only preoperative radiological findings or intraoperative pathological findings. Based on our experience and analysis of the characteristic radiological and pathological features in previous cases, we suggest that an accurate intraoperative diagnosis is possible. The key element is the combination of correct interpretation of the intraoperative pathology analysis and careful evaluation of the preoperative radiological studies. An appropriate intraoperative judgment is important, because the treatment, including the surgical management, would be totally different for schwannoma and glioma.     

Endoscope-assisted minilaparotomic radical retropubic prostatectomy

OBJECTIVE: To assess the clinical efficacy of endoscope-assisted minilaparotomic radical retropubic prostatectomy (EAM-RRP) compared with conventional radical retropubic prostatectomy (cRRP). METHODS: From September 2001 to December 2003, 30 patients with localized prostate cancer were treated by EAM-RRP. The surgical manipulation was performed through the wound with thoracoscopic assistance, using standard surgical instruments. In all cases, 800 mL of blood was collected from the patient for autotransfusion. For both EAM-RRP and cRRP, the internal iliac and obturator lymph nodes were dissected before the prostate removal. Clinical indicators such as operation time, blood loss, and duration of postoperative urine incontinence were analysed in the two groups. RESULTS: The postoperative period before ambulation and the duration of postoperative urine incontinence were significantly shorter after EAM-RRP than after cRRP, while no significant difference was found in operation time, blood loss, and duration of urethral catheterization. None of the cases required allotransfusion. CONCLUSION: EAM-RRP, which had a shorter postoperative period before ambulation and continence, is considered a safe and useful technique for radical prostatectomy.     

Severe autoimmune hemolytic anemia associated with IgM warm auto‐antibodies in primary Sjögren’s syndrome

Primary Sjögren’s syndrome is an autoimmune disorder involving mainly salivary and lachrymal glands. However, many extraglandular symptoms have also been reported. Although leucocytopenia and lymphocytopenia are frequently observed in hematological disorders, autoimmune hemolytic anemia is rarely reported. We experienced a case of primary Sjögren’s syndrome developing severe autoimmune hemolytic anemia. The patient’s red blood cells showed spontaneous agglutination in saline at room temperature, and immunoglobulin M (IgM) was detected on the surface of red blood cells by flow cytometry, indicating that autoimmune hemolytic anemia was caused by warm reactive IgM antibodies. Immediate corticosteroid therapy resulted in a dramatic recovery. We report a first case of severe autoimmune hemolytic anemia caused by warm reactive IgM antibodies in primary Sjögren’s syndrome.