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Biomedical subjects

Thomas Ullman

Publications and source records attributed to Thomas Ullman.

7 recordsLinked to original sources
PubMed2005

Gastrointestinal manifestations of Fabry disease: clinical response to enzyme replacement therapy.

Gastrointestinal symptoms are often an early and prominent manifestation of Fabry disease, an X-linked inborn error of metabolism caused by the deficient activity of the lysosomal enzyme, alpha-galactosidase A. This enzyme deficiency results in the progressive accumulation of globotriaosylceramide and other glycosphingolipids in tissue lysosomes throughout the body. In classically affected patients, glycosphingolipid accumulation in the vascular endothelium eventually culminates in life-threatening renal, cardiac, and cerebrovascular disease. In addition, over 50% of patients experience post-prandial abdominal pain and diarrhea that interferes with the ability to work and quality of life. Here, we describe four males aged 17-40 years with classic Fabry disease and severe gastrointestinal symptoms who participated in clinical trials of enzyme replacement therapy with agalsidase beta (Fabrazyme, 1 mg/kg every 2 weeks). Before therapy, the three adult patients experienced post-prandial abdominal pain, bloating, and severe diarrhea with 7-10 bowel movements per day every day and the 17-year-old had weekly episodes of diarrhea with six bowel movements per day. Other symptoms included vomiting, food intolerance, and poor weight gain. All patients took medications for these symptoms (diphenoxylate-atropine [Lomotil], ranitidine hydrochloride [Zantac], or sulfasalazine). After 6-7 months of agalsidase beta therapy, all patients reported "no or only occasional" abdominal pain or diarrhea, had discontinued their gastrointestinal medications, and had gained 3-8 kg. These marked improvements in gastrointestinal symptoms have persisted for over 3 years of treatment. In such patients, enzyme replacement at 1 mg/kg effects an early and significant clinical improvement in the gastrointestinal manifestations of Fabry disease.

Abdominal Pain↗
PubMed2005

Chemoprevention of colorectal neoplasia in ulcerative colitis: the effect of 6-mercaptopurine.

BACKGROUND & AIMS: Evidence suggests that mesalamine-based anti-inflammatory medicines may prevent colorectal cancer (CRC) in ulcerative colitis (UC). If mesalamine exerts its chemopreventive effect by its anti-inflammatory activity, then other medications that reduce colitis activity also should possess chemopreventive properties. Our aim was to determine the effect of the immunomodulators 6-mercaptopurine (6MP) and azathioprine (AZA) in preventing the development of dysplasia or CRC in UC. METHODS: Patients with UC who underwent a surveillance colonoscopy in 1996-1997 were identified from a gastrointestinal pathology database. A proportional hazards analysis assessing 6MP/AZA use as a time-changing covariate was performed to evaluate the effect of 6MP/AZA on: (1) progression to any neoplasia (low-grade dysplasia, high-grade dysplasia, or CRC), and (2) progression to advanced neoplasia (high-grade dysplasia or CRC). RESULTS: A total of 315 subjects met inclusion criteria and were followed for an average of 8 years from their first surveillance examination. There were no significant differences in rates of progression to advanced neoplasia or to any neoplasia between 6MP/AZA users and never-users by log-rank testing. The proportional hazards analysis resulted in hazard ratios of 1.06 (95% confidence interval, .59-1.93) and 1.30 (95% confidence interval, .45-3.75) when considering the effect of exposure to 6MP/AZA on progression to any or to advanced neoplasia, respectively. The results were unaffected by known potential confounders. CONCLUSIONS: In UC patients with no initial history of dysplasia, 6MP/AZA use appears to have little or no effect on the rate of neoplastic transformation in the colon. Importantly, the use of 6MP/AZA did not increase malignant transformation in UC.

Adult↗
PubMed2004

Patterns of colonic involvement at initial presentation in ulcerative colitis: a retrospective study of 46 newly diagnosed cases.

Studies have shown that rectal sparing and patchiness develop in treated and longstanding ulcerative colitis (UC), making the distinction from Crohn colitis increasingly difficult after treatment is initiated. However, no histologic studies of the incidence of rectal sparing in adults at UC onset have been performed. Colectomy specimens from 46 patients with classic UC histologic features and no Crohn disease features were identified. Biopsy specimens obtained before medical therapy were retrieved and examined blindly by 2 pathologists, along with appropriate control samples. Slides were scored for chronicity (crypt branching, subcryptal plasma cells, lamina propria plasma cells) and activity (cryptitis, crypt abscesses, epithelial injury). In 28 cases, only rectal biopsy specimens were taken; for 16, rectal and at least 1 proximal biopsy specimen were taken. All cases showed rectal involvement; none had rectal sparing at initial biopsy. Of 16 cases with rectal and more proximal biopsy specimens, 5 (31%) showed relative rectal sparing (lower scores in rectum than in more proximal sites). In 16 cases with rectal and more proximal biopsy specimens, chronicity and activity scores were higher in the rectum than in more proximal sites (P = .01; chronicity and activity). The mean overall chronicity score decreased in a linear manner from rectum to cecum. The rectum is involved and shows evidence of chronicity and activity at disease onset in UC, using colectomy as the gold standard for diagnosis. Because rectal sparing at UC onset has been reported, a prospective study using uniform biopsy protocols is needed to establish the true incidence of rectal sparing at presentation.

Adolescent↗
PubMed2003

Progression of flat low-grade dysplasia to advanced neoplasia in patients with ulcerative colitis.

BACKGROUND & AIMS: Long-standing ulcerative colitis has long been recognized as a risk factor for colorectal cancer, but there is still no universal consensus on the optimal management of ulcerative colitis patients with low-grade dysplasia in flat mucosa. Some authorities favor prompt colectomy, whereas others recommend continued surveillance. The purpose of our study was to determine the frequency with which flat low-grade dysplasia in ulcerative colitis progresses to advanced neoplasia (high-grade dysplasia or colorectal cancer) and whether specific variables could predict such progression. METHODS: We reviewed the medical histories, colonoscopic findings, and surgical and pathology reports of 46 patients with ulcerative colitis diagnosed with flat low-grade dysplasia on a surveillance colonoscopy. The rates of neoplastic progression, as well as the frequency of advanced neoplasia, were tabulated. We correlated progression with several clinical and colonoscopic variables: the number of biopsy samples positive for flat low-grade dysplasia, the duration and anatomic extent of disease, patient age, and medication use. RESULTS: Among these 46 patients, there were 7 cases of colorectal cancer, 5 of which were stage II or higher. Unexpected advanced neoplasia occurred in 4 of 17 (23.5%) patients who underwent colectomy for flat low-grade dysplasia. On an actuarial basis, the rate of neoplastic progression was 53% at 5 years. No clinical features predicted progression to advanced neoplasia. Cancers, including 2 at advanced stages, developed despite frequent follow-up surveillance examinations. CONCLUSIONS: A finding of flat low-grade dysplasia during ulcerative colitis surveillance is a strong predictor of progression to advanced neoplasia. Early colectomy should be recommended for such patients.

Actuarial Analysis↗