Sherman M. Chamberlain

Thyroid Hormone Differentially Regulates Rat Intestinal Brush Border Enzyme Gene Expression

Thyroid hormone [triiodothyronine (T3)] has been shown to play a critical role in the growth and maturation of the mammalian small intestine, but its mechanism of action has not been well studied. In the current study, an animal model of hypothyroidism and hyperthyroidism was used to study the effects of T3 on the small intestine. Adult rats were treated with propylthiouracil for a 6-week period and then given injections of either saline (hypothyroid) or 30 micrograms/100 g body wt of T3 (hyperthyroid). Northern blot analyses showed marked differential regulation of brush border enzyme gene expression. Lactase messenger RNA (mRNA) levels decreased approximately 75% along the length of the small intestine, whereas sucrase levels were unchanged. The intestinal alkaline phosphatase mRNA species were upregulated by T3, especially the 3-kilobase band, which increased most dramatically in jejunum. Further experiments showed significant levels of both the alpha-1 and beta-1 T3 receptor mRNAs within the small intestinal mucosa. Histological examination showed that T3 treatment causes marked villus hyperplasia throughout the length of the small intestine. These results provide insight into the mechanism by which T3 exerts its influence on the growth and differentiation of the intestinal epithelium.

Lubiprostone used with polyethylene glycol in diabetic patients enhances colonoscopy preparation quality.

AIM To assess the additive effect of lubiprostone on the quality of colon preparation in diabetics given single-dosed polyethylene glycol electrolyte (PEG) for colonoscopy. METHODS This was an investigator-initiated, single-center, single-blinded prospective trial comparing the efficacy of L + PEG to PEG alone on colon preparation quality in diabetics undergoing screening colonoscopy. The study was approved by our institutions IRB. The PEG was given as a single-dose to address patient-compliance concerns voiced by our IRB with split-dosing. All patients received only clear liquids the day prior to colonoscopy. Experimental group (Grp L) received PEG + 1 dose L 2 h prior to and 2 h after PEG completion. Control group (Grp C) received only PEG the evening prior to the colonoscopy. Patients were randomly assigned to one of the 2 groups. The endoscopist was blinded to which colon prep was given and all colonoscopies were complete. Upon colonoscopy completion, the endoscopist rated the colon prep-quality by a validated 5-point Likert scale (1-excellent to 5-inadequate). RESULTS Sixty patients were enrolled in the study; 30 Grp L and 30 Grp C. Overall, patients were excluded due to study non-completion in 12 (41%) Grp L and 5 (17%) Grp C, P = 0.04. Average colon preparation score Grp L = 2.47 and Grp C = 3.00, P = 0.09. Although this was not statistically significant, there was a trend towards improved colon prep in Grp L. Statistical significance may have been achieved if completion rates had been similar between both study groups. CONCLUSION Use of 2-L capsules with PEG resulted in a trend towards improved colon prep over PEG alone in diabetic patients when given as a single-dose regimen.

Colonoscopy polypectomy management in Glanzmann’s thrombasthenia

Glanzmanns thrombasthenia (GT) is a rare autosomal recessive bleeding syndrome characterized by abnormal Glycoprotein IIb/IIIa complex (GIIb/IIIa) on platelets with resultant abnormality in platelet aggregation. There is very little information regarding polypectomy management in GT. We report a single patient with this rare disease, who underwent sequential endoscopic management of large colon polyps. Polypectomy in our GT patient was complicated by immediate and delayed bleeding. Multiple clips used after standard cautery polypectomy for a polyp 10 mm or larger in our GT patient, was most effective in preventing immediate and delayed post-polypectomy bleeding than other known therapeutic approaches. We favor preemptive use of multiple clips in large polypectomy defects for GT patients and we may argue the added cost may be offset by the reduction in the need for blood products, and by averting or shortening potential hospitalizations.

Unintentional Weight Loss as the Sole Indication for Colonoscopy is Rarely Associated with Colorectal Cancer

Introduction: Weight loss is a commonly used indication for colonoscopy. Methods: This is a prospective case study of colonoscopies from 1998 to 2009. Descriptive statistics were used to evaluate age, sex, colonoscopy indications, and findings. Multiple logistic regression analysis was used to determine the odds of colorectal cancer (CRC) based on age, sex, and weight loss. Results: We reviewed 6425 colonoscopies. The mean age of patients was 57.4 years (SD, ±13.5 years), and 55% of patients were women. One hundred thirty-six (2.1%) of these had unintentional weight loss; for 32 patients (0.4%), unintentional weight loss was the only indication for the procedure. CRC was diagnosed in 116 patients (1.8%), but CRC was not detected in any patients for whom unintentional weight loss as the only indication for colonoscopy. Conclusion: Based on our prospective case study, unintentional weight loss alone was not associated with CRC.