Pancreatic transplantation with duodenoduodenostomy drainage: technique, normal radiological appearance and complications.

Pancreas transplantation is considered the curative treatment for severe type 1 diabetes mellitus in selected cases. Since the first procedure in 1966, surgical techniques have been improved. The current trend among most medical centers, as well as at our Institution, is enteric drainage and systemic venous or portal anastomosis. The aim of this pictorial essay is to describe the main imaging features of pancreatic transplantation with duodenoduodenostomy drainage.

Co-localization of nestin and insulin and expression of islet cell markers in long-term human pancreatic nestin-positive cell cultures.

Strategies to differentiate progenitor cells into beta cells in vitro have been considered as an alternative to increase beta cell availability prior to transplantation. It has recently been suggested that nestin-positive cells could be multipotential stem cells capable of expressing endocrine markers upon specific stimulation; however, this issue still remains controversial. Here, we characterized short- and long-term islet cell cultures derived from three different human islet preparations, with respect to expression of nestin and islet cell markers, using confocal microscopy and semi-quantitative RT-PCR. The number of nestin-positive cells was found to be strikingly high in long-term cultures. In addition, a large proportion (49.7%) of these nestin-positive cells, present in long-term culture, are shown to be proliferative, as judged by BrdU incorporation. The proportion of insulin-positive cells was found to be high in short-term (up to 28 days) cultures and declined thereafter, when cells were maintained in the presence of 10% serum, concomitantly with the decrease in insulin and PDX-1 expression. Interestingly, insulin and nestin co-expression was observed as a rare event in a small proportion of cells present in freshly isolated human islets as well as in purified islet cells cultured in vitro for long periods of time. In addition, upon long-term subculturing of nestin-positive cells in 10% serum, we observed reappearance of insulin expression at the mRNA level; when these cultures were shifted to 1% serum for a month, expression of insulin, glucagon and somatostatin was also detected, indicating that manipulating the culture conditions can be used to modulate the nestin-positive cell's fate. Attempts to induce cell differentiation by plating nestin-positive cells onto Matrigel revealed that these cells tend to aggregate to form islet-like clusters, but this is not sufficient to increase insulin expression upon short-term culture. Our data corroborate previous findings indicating that, at least in vitro, nestin-positive cells may undergo the early stages of differentiation to an islet cell phenotype and that long-term cultures of nestin-positive human islet cells may be considered as a potential source of precursor cells to generate fully differentiated/ functional beta cells.

[Efficacy of contrast chromoendoscopy of the colon after oral administration of indigo carmine dye]. / Eficácia da cromoendoscopia de contraste do cólon com emprego do índigo-carmim administrado por via oral.

INTRODUCTION: Indigo carmine dye is usually spread directly over the colon in many chromoscopic techniques aiming better visualization of a lesion already detected by conventional colonoscopy. Examination of the colon already stained by oral administration of indigo carmine dye may increase detection of small lesions resulting in higher sensibility of the colonoscopy in diagnosing diminutive lesions. OBJECTIVE: Analyze the results regarding the quality of chromoscopic technique and the indigo carmine dye distribution over the colon after oral administration. PATIENTS AND METHODS: Fifty patients undergoing colonoscopy were evaluated. A capsule containing 100 mg of indigo carmine dye was offered to these patients 30 min before oral mannitol prep routinely used. The indigo carmine dye contrast effect was graded as bad, regular or good according to preestablished criteria in three segments of the colon: right and left colon and the rectum. RESULTS: In the right colon, good indigo carmine dye contrast effect was observed in only 9 (18.8%) patients, while it was considered regular and bad in 32 (66.6%) and in 7 (14.6%) patients, respectively. A good indigo carmine dye contrast effect was never observed in this series for the left colon or in the rectum. As a matter of fact, no indigo carmine dye was observed in the left colon in 80.9% and in the rectum in 92% of patients in this series. CONCLUSION: Although it may be simple and desirable, oral administration of indigo carmine dye seems ineffective for enhancing detection of diminutive lesions by chromoscopy as result of poor colonic distribution of indigo carmine dye mainly at distal colonic sites.