Increase of white matter string vessels in Alzheimer's disease.

String vessels are collagenous structures connected to capillaries. They have no endothelial cells or lumen. We assessed collagen IV-labeled string vessels in the white matter (WM) of subjects with Alzheimer's disease (AD) (n = 12) and non-AD controls (n = 11) using 100 microm celloidin sections. Ten standard fields were digitally captured and the number and length of normal vessels and string vessels were quantified by computerized image analysis. The WM of the AD-diagnosed individuals contained more strings per mm2 (3.95 +/- 0.49) than comparable WM from controls (1.36 +/- 0.39) (p = 0.0005) and had increased total string vessel length in mm/mm2 (AD = 0.29 +/- 0.04; control = 0.10 +/- 0.03; p = 0.0015). There was a 25% increase (not statistically significant) in vessel density in mm/mm2 in AD subjects (AD = 11.88 +/- 0.87; control = 9.53 +/- 0.78; p = 0.06), presumably due to brain atrophy in the white matter. Although vessel length was slightly increased in AD subjects, they still had more than double the string length per total vessel length (AD = 2.88 +/- 0.38) compared to controls (1.36 +/- 0.27) (p = 0.0057). This increase in string vessels in the white matter of AD subjects suggests a decrease in vascular supply in this disease.

Laparoscopic radiofrequency ablation of the liver in proximity to major vasculature: effect of the Pringle maneuver.

BACKGROUND AND OBJECTIVES: The Pringle maneuver has been shown to increase ablation size during radiofrequency ablation (RFA). Efficacy of laparoscopic Pringle in proximity to major vasculature has not been well described. Laparoscopic RFA was performed in proximity to major hepatic vessels to examine effects of the Pringle on ablation size and vascular damage. METHODS: Laparoscopic RFA was performed in 10 pigs. Each underwent ablation of a peripheral site, and sites adjacent to the portal and hepatic veins. Ultrasound was used to position the RFA adjacent to vascular structures. US flow characteristics verified occlusion of blood flow. Five pigs underwent laparoscopic RFA with Pringle and five underwent laparoscopic RFA alone. Animals were then sacrificed for gross and microscopic evaluation. RESULTS: Peripheral, hepatic, and portal vein ablations showed no significant differences in volume between non-Pringle and Pringle lesions, though the median ablation volume for the peripheral site in the Pringle group was approximately twice that of the non-Pringle group. Pringle group overall median time to target temperature was significantly shorter (P = 0.047). Histologic examination revealed no evidence of endothelial damage or thermal-induced intravascular thrombosis of the hepatic or portal veins. CONCLUSIONS: Laparoscopic RFA with Pringle in proximity to major vascular structures does not significantly increase ablation size, or cause acute vascular damage. Further studies are necessary to determine the utility of the Pringle in proximity to major intrahepatic blood vessels.

Xanthoma disseminatum: a rare intracranial mass.

We report the CT, MR imaging, and histologic findings in a patient with an intracranial mass diagnosed as xanthoma disseminatum (XD). The mass demonstrated radiographic findings typical for a glioma. However, histologic examination of brain and dermal lesions showed findings characteristic of XD. XD is a rare dermatologic disorder of unknown cause that may be accompanied by systemic manifestations. In rare cases, it can appear as an intracranial mass.