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.

Flavonoid-Peroxidase Reaction as a Detoxification Mechanism of Plant Cells against H2O2.

Recent studies have revealed that dietary flavonoids are potent radical scavengers, acting in a manner similar to ascorbate and [alpha]-tocopherol. However, it is still not clear whether flavonoids have a similar antioxidative function in plants. We examined the possibility that flavonoids could function as stress protectants in plant cells by scavenging H2O2. Two major flavonoids, quercetin and kaempferol glycosides, were isolated from leaves of the tropical tree Schefflera arboricola Hayata. Both glycosides and aglycones of isolated flavonols were oxidized by H2O2 in the presence of horse-radish peroxidase and/or in a soluble fraction of S. arboricola leaf extract. The rates of oxidation were in the order quercetin > kaempferol > quercetin glycoside >> kaempferol glycoside. Judging from the effects of inhibitors such as KCN, p-chloromercuribenzoate, and 3-amino-1H-1,2,4-triazole, we conclude that guaiacol peroxidase in the soluble fraction catalyzes H2O2-dependent oxidation of flavonols. In the flavonol-guaiacol peroxidase reaction, ascorbate had the potential to regenerate flavonols by reducing the oxidized product. These results provide further evidence that the flavonoid-peroxidase reaction can function as a mechanism for H2O2 scavenging in plants.

Deoxycytidine monophosphate deaminase in Acetabularia: properties and regulation in the early generative phase.

The occurrence of a dCMP deaminase in Acetabularia mediterranea has been demonstrated. The enzyme which is found in a particulate fraction is substantially stimulated by the addition of dCTP. The activity of the enzyme is increased at the beginning of the generative phase in nucleate as well as in anucleate cells. This regulation is due to de novo synthesis of the enzyme. By means of inhibitor studies, it has been shown that the enzyme is translated on 70S ribosomes of and coced for in cell organelles.