Comprehensive diagnostic ability of endocytoscopy compared with biopsy for colorectal neoplasms: a prospective randomized noninferiority trial.

BACKGROUND AND STUDY AIMS: Endocytoscopy enables observation at 450-fold magnification during gastrointestinal endoscopy, allowing on-site "optical biopsy." We compared the accuracies of endocytoscopy and standard biopsy for the diagnosis of colorectal neoplasms. PATIENTS AND METHODS: We performed a randomized, controlled, open-label trial of patients with colorectal lesions (≥ 5 mm) detected during colonoscopy in a tertiary referral center. We randomly assigned the 203 detected lesions of 170 eligible patients to either the endocytoscopy or standard biopsy group. An on-site endoscopist assessed the histopathology of the endocytoscopy group lesions according to the endocytoscopic findings, whereas a pathologist later assessed standard biopsy group lesions by microscopic examination of the biopsy specimens. We calculated the diagnostic accuracies in both groups with reference to the final histopathology of the resected specimens. The primary endpoint was to determine whether the diagnostic accuracy of endocytoscopy for neoplastic lesions was noninferior to that of standard biopsy (with a predefined noninferiority margin of 10%). Analyses were by intention-to-treat and per-protocol. The study is registered, number UMIN000003923. RESULTS: Overall, 102 lesions in the endocytoscopy group and 101 in the standard biopsy group were available for primary outcome analysis. There were no complications. The diagnostic accuracy of endocytoscopy for the discrimination of neoplastic lesions was 94.1% (95% confidence interval 87.6% to 97.8%), whereas that of standard biopsy was 96.0% (90.2% to 98.9%), which is within the noninferiority margin (absolute difference -1.9%, -8.6% to +5.0%). CONCLUSIONS: Endocytoscopy is noninferior to standard biopsy for the discrimination of neoplastic lesions. With its advantage of providing an on-site diagnosis, endocytoscopy could provide a novel alternative to standard biopsy in routine colonoscopy.

Diagnosis of colorectal lesions with a novel endocytoscopic classification - a pilot study.

BACKGROUND AND STUDY AIMS: Recent advances in endocytoscopy have enabled in vivo evaluation not on ly of structural atypia, but also of cellular atypia with observation of lumens and nuclei in the surface layer of the mucosa. The aim of this prospective pilot study was to evaluate the usefulness of our novel endocytoscopic classification in colorectal lesions. PATIENTS AND METHODS: A total of 206 consecutive patients were enrolled in the study and underwent endocytoscopic examination. Endocytoscopic images were stored electronically and two endoscopists blinded to the findings at live examination assigned them diagnoses using the endocytoscopic (EC) classification. The endocytoscopic diagnosis was then compared to the final histopathological diagnosis. RESULTS: In all, 196 patients with 213 specimens were available for analysis. All normal mucosae were classified as EC1a and all hyperplastic polyps as EC1b. Dysplasias were mainly classified as EC2, while massively invasive submucosal cancers (SMm) or worse, which have the possibility of metastasis, were mainly EC3b. Assuming that an EC1b classification was diagnostic of hyperplastic polyps, we were able to differentiate nonneoplastic from neoplastic lesions with a sensitivity of 100 % and a specificity of 100 % (P < 0.05). Assuming that an EC3b classification was diagnostic of SMm or worse, we were able to differentiate "SMm or worse" from other neoplastic lesions (dysplasias and slightly invasive submucosal cancers) with a sensitivity of 90.1 % and a specificity of 99.2 % (P < 0.05). CONCLUSIONS: The endocytoscopic classification was particularly useful for differentiating between neoplastic and nonneoplastic lesions and between "SMm or worse" and other neoplastic lesions, which in the case of colorectal neoplasms would help to determine treatment.

Effect of glutaraldehyde on NADPH oxidase system of guinea pig polymorphonuclear leukocytes.

In an attempt to elucidate properties and activation mechanisms of the NADPH oxidase system, which is known to be responsible for the production of superoxide anion (O2-) in cell membranes of polymorphonuclear leukocytes (PMNL), intact guinea pig PMNL were treated with glutaraldehyde, a protein crosslinking reagent, before or after stimulation with phorbol 12-myristate 13-acetate (PMA). Then, PMNL were disrupted and NADPH oxidase activity was measured. After the treatment of resting PMNL with glutaraldehyde, NADPH oxidase was no longer activated by PMA. On the other hand, the NADPH oxidase activity enhanced by PMA in advance was markedly retained by the glutaraldehyde treatment of such PMA-stimulated PMNL as compared to that in untreated cells. Similar retention by glutaraldehyde of the stimulated NADPH oxidase activity was observed in PMNL stimulated by formyl-methionyl-leucyl-phenylalanine (FMLP) and cytochalasin D. Furthermore, the oxidase activity of glutaraldehyde-treated PMNL was stable during incubation at 37 degrees C, the half life of the oxidase activity of the treated PMNL being more than 90 min whereas that of the untreated PMNL is about 15 min. This ability of the glutaraldehyde treatment to retain the activity was also observed against inactivation by high concentrations of NaCl and by positively charged alkylamine.

Mechanism for the inhibitory effect of a seleno-organic compound, Ebselen, and its analogues on superoxide anion production in guinea pig polymorphonuclear leukocytes.

Effects of Ebselen and its analogs (PZ-25, NAT06-123, NAT02-761, NAT02-801, NAT06-099, and NAT06-513) on superoxide anion (O2-) production induced by tetradecanoyl phorbol acetate (TPA) were examined in intact guinea pig polymorphonuclear leukocytes (PMNL). Four compounds having a structure of 1,2 benzoisoselenazol-3-(2H) one (Ebselen, NAT06-123, and NAT02-761) and its sulfur-substituted analog (PZ-25), had a potent inhibitory effect on O2- production as compared with others. Ebselen and NAT06-123 also markedly inhibited nicotinamide adenine dinuclestide phosphate (NADPH) oxidase activity, which is responsible for O2- production in intact cells, and in a particulate fraction prepared from TPA-stimulated PMNL, whereas PZ-25 inhibited this enzyme weakly and NAT02-761 did not. On the other hand, Ebselen and PZ-25 had the same degree of potent inhibitory effect on protein kinase C which was involved in the regulation of NADPH oxidase activation. Thus, it is plausible that inhibition of O2- production in intact PMNL by these compounds were due not only to direct inhibition of NADPH oxidase but also to inhibition of protein kinase C.