Thrombin has multiple functions, including its function as a key enzyme during blood coagulation and other physiologic activities. We studied brain tissue reactions to thrombin that might be present in the central nervous system (CNS) following injury. Thrombin and three different types of controls--buffer, albumin, and plasmin--were individually infused into the rat caudate nucleus by a continuous osmotic mini-pump. Brains were examined by conventional histologic and immunohistologic techniques. Antibodies for bromodeoxyuridine (BrdU), glial fibrillary acidic protein (GFAP), vimentin, and laminin were employed to assess the infiltration of inflammatory cells, proliferation activity of cells, and reaction of astrocytes and mesenchymal cells, respectively. The number of inflammatory cells, number of BrdU-positive cells, area and number of vimentin-positive astrocytes, and the area of GFAP-positive astrocytes were quantitatively analyzed. Thrombin caused infiltration of inflammatory cells, proliferation of mesenchymal cells, induction of angiogenesis, and an increase in vimentin-positive reactive astrocytes. These histologic changes caused by thrombin infusion resembled the inflammation, scar formation, and reactive gliosis in the CNS following injury. These results suggest that thrombin may play an important role in inflammatory responses to CNS injury since thrombin is one of the blood borne factors that may interact with brain tissue after CNS injury. The data further suggest that the therapeutic application of antithrombin agents for CNS injury suppresses inflammation and the excessive gliosis and scar formation, which are barriers to neuronal regeneration.

Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored< 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; < 0.001). This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).

Subarachnoid haemorrhage (SAH) often leads to subarachnoid fibrosis and resultant normal pressure hydrocephalus; however, how subarachnoid fibrosis occurs is unknown. We examined the changes within arachnoid granulations (AGs) and the subarachnoid space (SAS) chronologically at the parasagittal region obtained from patients with SAH at autopsy and made comparison with controls by immunostaining for cytokeratin, specific marker for leptomeningeal cells and by the elastica Masson-Goldner methods. Within a week some AGs were torn, and many inflammatory cells filled the AGs and SAS. Cytokeratin positive cells were scarce. During the next two weeks cytokeratin positive cells increased. After three weeks, AGs and SAS were filled by dense deposits of extracellular matrices surrounded by multiple layers of leptomeningeal cells.

CSF overproduction caused by bilateral choroid plexus papillomas can result in hydrocephalus. Radical resection of the bilateral ventricular lesions should be considered for this entity. Thorough evaluation of the surgical specimen is recommended because histological examination of only the lobular surface of the choroid plexus lesion may fail to identify choroid plexus neoplasm.

Gangliocytic paraganglioma (GP) has been regarded as a rare benign tumor that commonly arises from the second part of the duodenum. As GP does not exhibit either prominent mitotic activity or Ki-67 immunoreactivity, it is often misdiagnosed as neuroendocrine tumor (NET) G1. However, the prognosis might be better in patients with GP than in those with NET G1. Therefore, it is important to differentiate GP from NET G1. Moreover, our previous study indicated that GP accounts for a substantial, constant percentage of duodenal NETs. In the present article, we describe up-to-date data on the clinicopathological characteristics of GP and on the immunohistochemical findings that can help differentiate GP from NET G1, as largely revealed in our new and larger literature survey and recent multi-institutional retrospective study. Furthermore, we would like to refer to differential diagnosis and clinical management of this tumor and provide intriguing information about the risk factors for lymph node metastasis on GP.

Endoscopic submucosal dissection with a transparent hood fitted with a mucosa-holding forceps channel is highly useful, safe and simple when applied to the esophagus.

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