The aim of this study was to investigate the differences between the clinicopathological findings in two histologic types of carcinoma of the papilla of Vater. We histologically classified carcinoma of the papilla into two types: 1) an intestinal type that resembles tubular adenocarcinoma of the stomach or colon, and 2) a pancreaticobiliary type that is characterized by papillary projections with scant fibrous cores. We examined 53 cases of resected carcinoma of the papilla. The intestinal‐type carcinomas were similar to the intestinal mucosa in that they had lysozyme‐containing, Paneth or argyrophil cells, as demonstrated by the immunohistochemically positive stainings for the anti‐lysozyme antibody. Although both the sizes of the two types of carcinomas and the age distributions of cases with the two types of carcinoma were almost the same, the prognosis of the cases with the intestinal type was much better than that of the cases with the pancreaticobiliary type. Histological lymph node metastasis was found significantly more often in the pancreaticobiliary type. This result was supported by the fact that small carcinomas of the intestinal type showed little or no invasion into the surrounding interstitium, as opposed to the pancreaticobiliary type, which had a strong infiltrative tendency. The pathogenesis of carcinoma of the papilla of Vater should be further evaluated, taking into consideration the existence of these two histologic types.

These findings demonstrate that apathy is a frequent symptom among elderly stroke patients and may be accompanied by cognitive impairments, depressive state, and frontal dysfunction. The hypoactivity in the frontal lobe and anterior temporal regions may contribute to symptoms of apathy after stroke.

Neuropsychological and neuroimaging studies have indicated that global and local features of a visual scene are processed differentially by the two hemispheres. Although visual selective attention is suggested to play a role in the hemispheric asymmetry, the precise mechanism of attentional control for the global-local processing is not fully understood. We investigated the neural correlates of cerebral asymmetry in directing attention to the global pattern and local components of a hierarchical stimulus. Event-related brain potentials (ERPs) were recorded while the subjects shifted their attention to the global or local level of a hierarchically structured letter. The shift direction was controlled by a preceding cue stimulus. The ERPs to the cue stimuli demonstrated that the right temporal-parietal and left posterior temporal regions were differentially activated during attentional allocation to the global and local levels, respectively. These effects started 240 msec after the cue stimulus. The late ERP components to the target stimuli also manifested the hemispheric global-local asymmetry as seen during the attentional shift. These electrophysiological results provided an asymmetrical neural basis for the "top-down" allocation of attention to global and local features and revealed the contribution of the temporal-parietal cortex to this attentional mechanism.

No abstract

In order to clarify genetic changes in flat adenomas, K‐ras codon 12 point mutations were examined in 56 flat adenomas, 81 polypoid adenomas and 42 cancers of colon and rectum. The mutation frequency in flat adenomas was 23% (13/56), significantly lower than that in polypoid adenomas (67%: 54/81) and cancers (76%: 32/42). Even mildly dysplastic adenomas or small (less than 5 mm) adenomas showed higher mutation incidence in polypoid type (62%, 57%) than in flat type (23%, 19%). Among flat adenomas, flat elevated lesions exhibited relatively higher mutation frequency than completely flat or depressed ones. As for cancers, 14 tumors (33%) contained mutations only in a minor tumor cell population, indicating that these mutations occur at a late stage of tumorigenesis. These results suggest that the adenoma‐carcinoma sequence through flat adenomas may he different from that through polypoid adenomas, and genetic changes may be heterogeneous in colorectal carcinogenesis.