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Justin A Maykel

Publications and source records attributed to Justin A Maykel.

9 recordsLinked to original sources
PubMed2006

Crohn's colitis: the incidence of dysplasia and adenocarcinoma in surgical patients.

PURPOSE: Data supporting an increased risk of colorectal cancer in patients with Crohn's colitis are inconsistent. Despite this, clinical recommendations regarding colonoscopic screening and surveillance for patients with Crohn's colitis are extrapolated from chronic ulcerative colitis protocols. The primary aim of our study was to determine the incidence of dysplasia and carcinoma in pathology specimens of patients undergoing segmental or total colectomy for Crohn's disease of the large bowel. In addition, we sought to identify risk factors associated with the development of dysplasia and carcinoma. METHODS: We performed a retrospective review of all patients operated on at our institution for Crohn's colitis between January 1992 and May 2004. Data were retrieved from patient charts, operative notes, and pathology reports. Logistic regression was used to model the probability of having dysplasia or adenocarcinoma. RESULTS: Two hundred twenty-two patients (138 females) who underwent surgical resection for the treatment of Crohn's colitis were included in the study. Mean age at surgery was 41 (range, 15-82) years and the mean duration of disease was 10 (range, 0-53) years. There were five cases of dysplasia (2.3 percent) and six cases of adenocarcinoma (2.7 percent). Three patients with dysplasia and one with adenocarcinoma were diagnosed on preoperative colonoscopy; while the other cases were discovered incidentally on pathologic examination of resected specimens. Factors associated with the presence of dysplasia or adenocarcinoma included older age at diagnosis (38.2 vs. 30.3 years, P = 0.02), longer disease duration (16.0 vs. 10.1 years, P = 0.05), and disease extent (90 percent extensive vs. 59 percent limited, P = 0.05). CONCLUSIONS: Patients with severe Crohn's colitis requiring surgery are at significant risk for developing dysplasia and adenocarcinoma, particularly when diagnosed at an older age, after longer disease duration, and with more extensive colon involvement.

Adenocarcinoma↗
PubMed2004

Abnormal regulation of serum lipid fatty acid profiles in short gut rats fed parenteral nutrition with lipid.

Despite absence of essential fatty acid deficiency (EFAD), increases in arachidonic acid to linoleic acid ratios occur in serum phospholipid of patients treated with chronic total parenteral nutrition (TPN). The parenteral lipid component of TPN contains abundant linoleate; thus low phospholipid linoleate may reflect increased conversion to arachidonate. Arachidonic acid excess has been associated with a proinflammatory milieu through increased eicosanoid production and might contribute to the increases in inflammatory markers seen in home TPN patients. We investigated fatty acid metabolism in a rodent model of malabsorption. We hypothesized that short gut rats would metabolize parenteral lipid differently from intact rats. We performed laparotomy and 80% small bowel resection (or sham surgery) in rats. Sixteen sham and 16 short gut rats were randomly assigned to TPN with lipid or fat-free TPN. After 5 days, weight loss was similar in all groups. Analysis of serum phospholipids demonstrated that 20:3omega9 (eicosatrienoic acid) was relatively increased in fat-free TPN groups, irrespective of surgery type, as were distal very long chain omega3 class fatty acids, as anticipated. Uniquely, both nutrition (TPN/lipid v fat-free TPN) and surgery type (sham v short gut) were significant in determining arachidonic acid levels. Relatively elevated arachidonate occurred in both groups of fat-free rats, suggesting increased Delta6 and/or Delta5 desaturase activity, as expected. In contrast, giving TPN/lipid lowered arachidonate (suggesting appropriately downregulated desaturases) in sham animals, but not in short gut animals. Ratios of arachidonic and di-homo-gamma-linolenic to linoleic acids further suggested increased turnover of precursor omega6 to arachidonic acid in short gut rats given lipid compared with the other groups. These preliminary data show that intravenous (IV) lipid gave rise to serum lipid fatty acid profiles that differed in short gut and sham rats. The short gut rat may have a heightened hepatic desaturase activity, inappropriate for the quantity of linoleic acid provided parenterally. Therefore, the short gut rat is an appropriate model to study further arachidonic acid excess in home TPN patients.

Animals↗
PubMedDate not supplied

Liver and skeletal muscle lipids have differing fatty acid profiles in short-gut rats fed via parenteral nutrition.

BACKGROUND: In short-gut rats, we showed marked abnormalities in plasma lipid fatty acids using parenteral nutrition (PN) with lipid vs sham surgery rats. This suggests that either sensing or metabolism of parenteral lipid is abnormal in malabsorption. The goal of this study was to determine fatty acid profiles in skeletal muscle and liver in short-gut rats treated with PN compared with sham rats. METHODS: Sprague-Dawley rats underwent laparotomy and massive small bowel resection (or sham surgery). Rats (n = 32, 16 sham, 16 short gut) were randomly assigned to PN with lipid or fat-free PN. After 5 days, weight loss was similar in all groups, and mixed hindlimb skeletal muscle and liver were biopsied. RESULTS: We found marked differences between liver and skeletal muscle. In livers of short-gut animals, 22:4omega6, 22:5omega6, and 22:6omega3 were higher (all p < .05) than in sham. In skeletal muscle, short gut had no effect on fatty acid profiles. In liver, fat-free PN led to significant increases in 20:3omega6, 22:4omega6, 22:5omega6, 20:3omega9, 20:5omega3, 22:6omega3, and triene/tetraene ratio (all p < .05) compared with feeding PN with lipid, irrespective of short gut. In muscle, levels of the distal long-chain fatty acid metabolites and triene/tetraene ratio were minimally affected by nutrition. Serum glucose and insulin concentrations were similar in all 4 groups. CONCLUSIONS: Both the presence of short gut and type of PN led to increases in distal metabolites of fatty acids on omega:3 and omega:6 pathway in liver phospholipids but not in skeletal muscle during short-term PN feeding in rats.

Animals↗