Biomedical subjects

J H Haseman

Publications and source records attributed to J H Haseman.

5 recordsLinked to original sources

PubMed1997

Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice.

BACKGROUND & AIMS: The relative sensitivities of barium enema and colonoscopy for colorectal cancer are still debated. The aim of this study was to determine the relative sensitivity of barium enema and colonoscopy in general clinical practice. METHODS: Medical records of 2193 consecutive colorectal cancer cases identified in 20 central Indiana hospitals were reviewed. All procedures performed within 3 years of the diagnosis were identified. RESULTS: The sensitivity of colonoscopy for colorectal cancer (95%) was greater than that for barium enema (82.9%), with an odds ratio of 3.93 for a missed cancer by barium enema compared with colonoscopy. The sensitivity of double-contrast barium enema (85.2%) was not different from that of single-contrast (81.8%). Barium enema performed no better in the right than the left colon. Cancers detected by colonoscopy were more likely to be Dukes' class A (24.9%) than cancers detected by barium enema (9.8%). Colonoscopy performed by gastroenterologists was more sensitive (97.3%) for cancer than colonoscopy by nongastroenterologists (87%), with an odds ratio of 5.36 for a missed cancer by a nongastroenterologist compared with a gastroenterologist. CONCLUSIONS: Hospital quality assurance committees and/or third-party payors should review the sensitivity of barium enema and colonoscopy by practitioners in their institutions. Corrective measures are recommended when sensitivity deviates significantly below the standard set by gastroenterologists performing colonoscopy in this study.

Barium Sulfate↗

PubMed1997

Failure of colonoscopy to detect colorectal cancer: evaluation of 47 cases in 20 hospitals.

BACKGROUND: Colonoscopy is the gold standard for the detection of colon polyps and cancers, but failed detections can occur and the reasons are incompletely understood. METHODS: During a retrospective evaluation of the sensitivity of barium enema and colonoscopy in 20 Indiana Hospitals, we encountered 47 cases of colorectal cancer in which a colonoscopy performed within 3 years of the diagnosis had not detected the cancer. Cases were reviewed for location of tumor, extenuating factors, pathologic features, delay in diagnosis from failed detection, and who performed the examination. RESULTS: Failed detection was more likely when colonoscopy was performed by a nongastroenterologist than a gastroenterologist (odds ratio 5:36, 95% CI [2.94,9.77]). Twenty-seven cancers were "missed," and 20 were estimated to be not reached. However, the location of missed tumors and a general absence of adequate documentation of cecal intubation suggested that some cecal and ascending colon cancers recorded as missed may actually have been not reached. Variation in sensitivity among gastroenterologists suggested that meticulous examination is also important in maximizing sensitivity. CONCLUSIONS: These cases suggest several factors that might improve the quality and sensitivity of colonoscopy: (1) examiners should receive adequate training, (2) cecal intubation rates should be high, (3) cecal intubation should be verified by specific landmarks in all cases, (4) failure to reach the cecum should be followed by prompt barium enema, and (5) meticulous examination would appear to improve sensitivity for cancer detection.

Aged↗

PubMed1996

Neoplasia distal to the splenic flexure in patients with proximal colon cancer.

BACKGROUND: Current American Cancer Society recommendations are that persons aged 50 years or older undergo screening flexible sigmoidoscopy every 3 to 5 years. In clinical practice, persons with adenomas at sigmoidoscopy are generally referred for full colonoscopy. However, cancers proximal to the splenic flexure may not be accompanied by neoplasia distal to the splenic flexure. METHODS: In order to estimate how often screening flexible sigmoidoscopy would be negative in persons with proximal cancer, we retrospectively reviewed 2053 consecutive colorectal cancer cases diagnosed from 1988 to 1994. Seven hundred ninety-nine (38.9%) had tumors proximal to the splenic flexure. We selected 358 study cases based on full colonoscopy performed and the colonoscopy reports available. RESULTS: Colonoscopy demonstrated distal adenomas in 77 cases (21.5%): 29 (8.1%) had hyperplastic polyps only, 4 (1.1%) had synchronous cancer, and 248 (69.3%) had no distal polyps. In this population, 77.4% of patients with proximal colon cancer had no distal neoplasia. We estimate that 30% of all patients with colorectal cancer would have a negative screening flexible sigmoidoscopy. CONCLUSIONS: Prospective evaluation of colonoscopic findings in persons with proximal cancers is needed. Ongoing evaluation of colonoscopy as a general screening test is appropriate.

Adenocarcinoma↗

PubMed1993

The evolution of pyoderma gangrenosum. A clinicopathologic correlation.

Pyoderma gangrenosum is a well-known clinical cutaneous condition, that has had a variety of conflicting microscopic descriptions. In an attempt to further our understanding of this condition, we obtained nine skin biopsy specimens of evolving, fully developed, regressing, and resolved lesions from six patients with pyoderma gangrenosum. We found that histopathologically, pyoderma gangrenosum evolves from folliculitis and abscess formation; it may also show leukocytoclastic vasculitis. The lesions then evolve to suppurative granulomatous dermatitis and finally regress with prominent fibroplasia. We illustrate the clinical and microscopic features herein and compare them to previous descriptions.

Adult↗

PubMed1988

Phosphoserine as a recognition determinant for glycogen synthase kinase-3: phosphorylation of a synthetic peptide based on the G-component of protein phosphatase-1.

Prior phosphorylation of its substrate has been shown to be important for substrate recognition by the protein kinase glycogen synthase kinase-3 (GSK-3). Phosphorylation of glycogen synthase by GSK-3 is known to be enhanced by the previous action of casein kinase II and the sequence -SXXXS(P)- was proposed as the minimal recognition determinant for GSK-3. The glycogen binding subunit of type 1 phosphoprotein phosphatase has been shown to be phosphorylated by cyclic AMP-dependent protein kinase at serine-13 in the sequence KPGFS(5)PQPS(9)RRGS(13)ESSEEVYV (F.B. Caudwell, A. Hiraga, and P. Cohen (1986) FEBS Lett. 194, 85-89). Inspection of the sequence revealed potential GSK-3 sites at residues 5 and 9. Using a synthetic peptide with the above sequence, we found that phosphorylation of serine-13 by cyclic AMP-dependent protein kinase permitted the recognition of serine-9 and serine-5 by GSK-3. The work provides another example of a substrate for GSK-3 and demonstrates that the action of GSK-3 is linked to the presence of phosphate in the substrate and not the action of any particular protein kinase. In the course of the analyses, a novel feature of trypsin cleavage of phosphopeptides was noted. In the sequence -SRRGS(P)- trypsin acted uniquely after the first arginine whereas in the sequence -S(P)RRGS(P)- it cleaved randomly at either arginine residue. The fact that GSK-3 could phosphorylate a peptide derived from a phosphatase subunit also raises the possibility that GSK-3 might be involved in controlling glycogen-associated type 1 phosphatase and, more generally, in mediating cyclic AMP control of protein phosphorylation in cells.

Arginine↗