Retraction brain ischaemia: mannitol plus nimodipine preserves both cerebral blood flow and evoked potentials during normoventilation and hyperventilation.

In our miniature swine model simulating operating room brain retraction, we investigated the effects of mannitol plus nimodipine on cerebral blood flow (CBF) and evoked potentials (EP) ipsilateral and contralateral to retraction, in comparison with either agent alone, during both normoventilation and hyperventilation. We here report results in 27 animals with intravenous mannitol (2 g kg-1 over 15 min) and/or nimodipine (1 microgram kg-1 min-1 constant infusion). Mannitol plus nimodipine was superior both to controls and to either mannitol alone or nimodipine alone in preserving EP amplitude ipsilateral to retraction during both normoventilation and hyperventilation. Mannitol alone was effective in normoventilation at preserving EP, while nimodipine alone was effective in hyperventilation. No significant asymmetries in CBF or EP were seen with mannitol plus nimodipine in either normoventilation or hyperventilation. By five minutes postretraction CBF had returned to preretraction values for all groups, and EP amplitude had returned also except for hyperventilated controls. In this model of brain retraction, mannitol plus nimodipine is superior to either agent alone in maintaining both CBF and EP when normoventilation and hyperventilation are employed. The results are discussed in terms of the possible mechanisms for the different and complementary effects of mannitol and nimodipine.     

MULTICENTER STUDY DESIGN OF THE EX VIVO EVALUATION OF ENDOCYTOSCOPY IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Optical technological innovations enable us to visualize cellular nuclei endoscopically. Herein is described a protocol design for a multicenter study for the ex vivo evaluation of endocytoscopy. The present study was performed by the Endoscopy Forum Japan study group.     

Histologic Classification of Endoscopically Removed Flat Colorectal Polyps: A Multicentric Study

A total of 594 flat colorectal polyps, removed at endoscopy, were histologically classified into non-neoplastic (n=49) and neoplastic (n=545) polyps. Non-neoplastic polyps were subdivided into metaplastic (n=45) and hyperplastic (n=4), whereas neoplastic polyps were subdivided into adenomas (n=481), intramucosal carcinomas (n=28) and invasive adenocarcinomas (n=36). Several adenoma phenotypes were discerned: tubular (n=375), serrated (n=59), villous (n=39), mixed (n=7) and fenestrated (n=1). Intramucosal carcinomas were subdivided into tubular (n=26) and serrated (n=2), and invasive adenocarcinomas into tubular (n=32), serrated (n=3) and fenestrated (n=1). The microscopic characteristics of each histologic phenotype described in this communication are defined and illustrated.     

A Case of Herpes Zoster Associated with Colitis

A 58-year-old Japanese woman who had herpes zoster in association with colitis was successfully treated with intravenously administrated acyclovir. Vesicular lesions with red haloes ranged from the left side of her buttock to the left extremity, corresponding to the L4 to S2 dermatomes. Her colitis was considered to have been induced by varicella-zoster virus, based on the facts that the clinical courses were correlated and that the innervation of the affected site of the colon corresponded to an infected dermatome (S2).     

Flat adenoma and flat mucosal carcinoma (IIb type)— A new precursor of colorectal carcinoma?

Two flat adenomas and a flat mucosal carcinoma of the colon were reported in patients with synchronous and metachronous colonic carcinomas. These lesions were almost flat and were not detected by preoperative endoscopic examinations. Colonoscopists should be aware of the presence of flat adenomas, which can be easily missed, and recognize them as lesions that play an important role in the "adenoma-carcinoma sequence."