The phylogenetic relationships of the suborder Acanthuroidei (Teleostei: Perciformes) based on molecular and morphological evidence.

Fragments of 12S and 16S mitochondrial DNA genes were sequenced for 14 acanthuroid taxa (representing all six families) and seven outgroup taxa. The combined data set contained 1399 bp after removal of all ambiguously aligned positions. Examination of site saturation indicated that loop regions of both genes are saturated for transitions, which led to a weighted parsimony analysis of the data set. The resulting tree topology generally agreed with previous morphological hypotheses, most notably placing the Luvaridae within the Acanthuroidei, but it also differed in several areas. The putative sister group of Acanthuroidei, Drepane, was recovered within the suborder, and the sister group of the family Acanthuridae, Zanclus, was likewise recovered within the family. Morphological characters were included to produce a combined data set of 1585 characters for 14 acanthuroid taxa and a single outgroup taxon. An analysis of the same 15 taxa was performed with only the DNA data for comparison. The total-evidence analysis supports the monophyly of the Acanthuridae. A parametric bootstrap suggests the possibility that the paraphyly of Acanthuridae indicated by the molecular analyses is the result of long-branch attraction. The disagreement between molecular and morphological data on the relationships of the basal acanthuroids and its putative sister taxon is unresolved.

Levels of colorectal ornithine decarboxylase activity in patients with colon cancer, a family history of nonpolyposis hereditary colorectal cancer, and adenomas.

Ornithine decarboxylase (ODC), a key enzyme in mammalian polyamine biosynthesis, has been proposed to be a marker of colonic epithelial cell proliferation and risk for colorectal cancer. We investigated the basal levels of ODC activity in sigmoid and rectal mucosae, and basal and tumor promoter 12-O-tetradecanoylphorbol-13-acetate-induced levels of skin ODC activity in individuals with a personal history of colon cancer (n = 9 colon; n = 58 skin), a family history of nonpolyposis hereditary colorectal cancer (n = 49; n = 42), adenomas (n = 16; n = 40), and healthy, family history-negative control subjects (n = 40; n = 79). Using a fresh tissue assay and samples obtained after a standard colon lavage preparation, colon mucosal ODC levels ranged from 0 to 192 pmol/mg/h (sigmoid, 0-163 pmol/mg/h; mean, 36 +/- 32 pmol/mg/h; rectum, 0-192 pmol/mg/h; mean, 35 +/- 32 pmol/mg/h). No differences among the four groups of subjects were found for either colon or skin ODC levels, and there were no sex differences overall or in any group. These results are not compatible with the suggestion that ODC levels are a useful marker of risk for colorectal cancer.

Absence of effect of supplemental oral calcium on ornithine decarboxylase (ODC) activity in colonic mucosae of healthy individuals with a family history of colorectal cancer.

Tissue activity levels of ornithine decarboxylase (ODC) have been suggested to be a marker of colonic epithelial cell proliferation and risk for colorectal cancer. Supplemental dietary calcium has been hypothesized and reported to suppress colonic epithelial-cell proliferation. We measured sigmoid and rectal mucosal ODC activity levels in 45 healthy, disease-free subjects with strong family histories of colorectal cancer before and after 2 months, during which daily dietary supplementation with calcium carbonate (to provide 600 mg calcium base) was taken. Although the mean ODC activity levels decreased in both sigmoid and rectal specimens, these changes were small in relation to the standard deviation and were not statistically significant. These data suggest that the magnitude of dietary calcium intake does not significantly influence sigmoid-rectal mucosal ODC activity levels and that ODC measurements may not be a useful intermediate endpoint for interventions designed to interrupt the colon carcinogenic sequence.

Colon ornithine decarboxylase activity following standard endoscopy preparation regimens.

Ornithine decarboxylase (ODC) catalyzes the formation of putrescine from ornithine, which is the first step in the pathway of mammalian polyamine biosynthesis. Tissue activity levels of ODC have been suggested to be a marker of risk for colorectal cancer in hereditary polyposis and in adenoma formers. We analyzed ODC activity in rectal and sigmoid colon mucosal biopsies obtained at 10 cm and at 30 cm in 40 healthy, colon cancer risk factor-free adults following three endoscopic preparation regimens: 1) no special preparation; 2) two phosphate enemas; and 3) "Colyte" lavage preparation 12 hr previously. Levels of ODC, measured in fresh tissue, were approximately twofold higher for enema preparation vs. no preparation (for log-transformed data: sigmoid, P less than 0.0001; rectum, P = 0.0001) and for enema preparation vs. lavage (sigmoid, P = 0.0002; rectum, P = 0.008). Lavage and no preparation ODC levels were not significantly different. ODC activity levels ranged from 0.00 to 352.96 pmol/mg/hr.

Balloon dilation for the treatment of stomal stenosis complicating gastric surgery for morbid obesity.

In a retrospective analysis, we evaluated our results with endoscopic dilation of enterostomy stenoses that complicated gastric procedures performed for the treatment of morbid obesity. Of 541 patients who underwent a gastric procedure for treatment of morbid obesity, we found 19 patients in whom endoscopic dilations of stenoses had been attempted. We also include three patients who had surgery elsewhere but who underwent dilations at our institution. Fourteen had stenoses complicating gastric bypass with Roux-en-Y anastomoses, and eight had stenoses complicating a gastroplasty (gastrogastrostomy). Two different types of dilation were attempted during the interval reviewed--Fogarty balloon dilations and Grüntzig balloon dilations. None of the eight patients with gastroplasties benefited from the attempted dilation, but 10 of the 14 patients with stenoses complicating gastric bypasses have done well. We found no significant difference between Fogarty and Grüntzig balloon dilations. We conclude that balloon dilation is an effective means of treating stenosis that complicates gastric bypass performed with Roux-en-Y anastomoses in cases of morbid obesity.

Symptomatic ectopic gastric epithelium of the cervical esophagus. Demonstration of acid production with Congo red.

Four patients were found with patches of gastric fundal type epithelium just distal to the cricopharyngeus, separated from the gastroesophageal junction by 15-20 cm of normal squamous epithelium. Three of the four had symptoms of dysphagia localized to the area of the esophagus containing the epithelium. Congo red dye (a pH indicator) applied to the mucosa during endoscopy revealed acid production by the mucosa after stimulation with pentagastrin. Interestingly, the patients' symptoms decreased during treatment with cimetidine only to return on cessation of therapy.

Normal mucosal histochemistry and histopathology in familial colorectal cancer.

Histochemical and histopathologic changes have been described in mucosa adjacent to and overlying neoplasms and non-neoplastic conditions of the large bowel. These changes are considered by some investigators to be preneoplastic changes. We studied mucosal biopsy specimens obtained at colonoscopy from all sections of large bowel in 34 asymptomatic subjects. Every subject had a documented family history of colorectal cancer (Cancer Family Syndrome of Lynch); in addition, two had previous colorectal cancers and two had cancers diagnosed at the time of colonoscopy. Consistent interpretations of mucin species secretion were not obtained. Microscopic mucosal abnormalities were not detected. Mucin histochemical and histopathologic changes are not promising markers for colorectal cancer in the Cancer Family Syndrome of Lynch.

Colonoscopy in asymptomatic individuals with a family history of colorectal cancer.

A prevalence screening program with colonoscopy was undertaken in four kindreds manifesting the cancer family syndrome. Forty-five percent of counseled patients underwent colonoscopy, providing 42 asymptomatic individuals. Seven patients (17%) were found to have adenomatous or villous polyps; two of these were malignant and one showed epithelial atypia. Three of the seven patients with polyps had multiple lesions. Only two patients had rectosigmoid polyps. From these limited data, colonoscopy is recommended as a useful screening procedure in individuals at high risk for colorectal cancer.