Chronic Pancreatitis with Benign Biliary Obstruction: Management Issues

Background

Benign biliary obstruction (BBO) is an important complication in patients with advanced chronic pancreatitis (CP). Its presentation varies from an incidental finding to overt jaundice. Thus it presents certain management issues. The present study was therefore performed to analyze the clinical presentation and management of biliary obstruction in patients with CP.

Methods

Retrospective analysis was performed from a prospectively collected database of 155 CP patients managed at our institute from October 2003 to June 2012.

Results

Among 43 (28 %) CP patients with biliary obstruction, 3 patients had evidence of malignancy on follow-up examination and were excluded from the final analysis. The various presentations include chronic nonprogressive elevation of serum alkaline phosphatase (SAP) (n = 15), a progressive increase in SAP with episodes of jaundice (n = 17), and persistent jaundice (n = 8). Of 15 patients with chronic nonprogressive elevation of SAP, 5 were managed conservatively, and the remaining 10 underwent only a pancreatic drainage procedure. During a median follow-up of 41 months (range 11–90 months), none of the 15 patients developed complications related to biliary obstruction. All patients with progressive increase in SAP levels and persistent jaundice underwent the biliary drainage procedure [choledochojejunostomy (CDJ, n = 20) and choledochoduodenostomy (CDD, n = 3)]. During a median follow-up of 30 months (range 10–89 months), two patients died of unrelated causes and two patients had an asymptomatic elevation of SAP.

Conclusions

BBO is common in patients with CP; however, biliary drainage is not indicated for chronic nonprogressive elevation of SAP. In patients with a progressive increase in SAP or persistent jaundice, both CDJ and CDD provide effective biliary drainage.     

Solubilization of the low density lipoprotein receptor

The low density lipoprotein (LDL) receptor was solubilized from membranes of bovine adrenal cortex and cultured human cells by incubation with the nonionic detergent octyl-beta-D-glucoside. Receptor activity released into the 100,000 x g supernatant was assayed by a solid-phase procedure: an aliquot of the soluble extract was removed, the detergent was diluted below its critical micellar concentration, causing the receptor to precipitate as a lipid-protein aggregate; the precipitate was collected by centrifugation and incubated with (125)I-labeled LDL ((125)I-LDL); and the receptor-bound (125)I-LDL was separated from free (125)I-LDL by filtration. The (125)I-LDL binding site that was precipitated from the soluble extract of bovine adrenocortical membranes appeared to be the same as the functional LDL receptor of cultured bovine adrenocortical cells and human fibroblasts. It exhibited high affinity and specificity (affinity for LDL more than 200-fold greater than for acetylated LDL, methylated LDL, or high density lipoprotein), dependence on calcium, and susceptibility to destruction by Pronase. The amount of (125)I-LDL binding activity in solubilized membranes from cultured cells was proportional to the number of receptors on the surface of the intact cells. Thus, the number of solubilized receptors was 1/20th of normal in mutant fibroblasts from a subject with homozygous familial hypercholesterolemia and was 1/4th of normal in human epithelioid carcinoma A-431 cells when they were grown in the presence of 25-hydroxycholesterol plus cholesterol. While in the soluble form in the presence of octyl-beta-D-glucoside, the LDL receptor can be carried through several steps of purification.     

Plasmonic Ag decorated CdMoO4 as an efficient photocatalyst for solar hydrogen production

The synthesis of Ag-nanoparticle-decorated CdMoO₄ and its photocatalytic activity towards hydrogen generation under sunlight has been demonstrated. The CdMoO₄ samples were synthesized by a simple hydrothermal approach in which Ag nanoparticles were in situ decorated on the surface of CdMoO₄. A morphological study showed that 5 nm spherical Ag nanoparticles were homogeneously distributed on the surface of CdMoO₄ particles. The UV/DRS spectra show that the band gap of CdMoO₄ was narrowed by the incorporation of a small amount of Ag nanoparticles. The surface plasmonic effect of Ag shows broad absorption in the visible region. The enhanced photocatalytic hydrogen production activities of all the samples were evaluated by using methanol as a sacrificial reagent in water under natural sunlight conditions. The results suggest that the rate of photocatalytic hydrogen production using CdMoO₄ can be significantly improved by loading 2% Ag nanoparticles: i.e. 2465 μmol h⁻¹ g⁻¹ for a 15 mg catalyst. The strong excitation of surface plasmon resonance (SPR) absorption by the Ag nanoparticles was found in the Ag-loaded samples. In this system, the role of Ag nanoparticles on the surface of CdMoO₄ has been discussed. In particular, the SPR effect is responsible for higher hydrogen evolution under natural sunlight because of broad absorption in the visible region. The current study could provide new insights for designing metal/semiconductor interface systems to harvest solar light for solar fuel generation.

Plasmonic enhancement of photocatalytic hydrogen generation is demonstrated using hierarchical Ag decorated CdMoO₄ synthesized using a hydrothermal method.     

Tractostorm: The what,why, and how of tractography dissection reproducibility

Investigative studies of white matter (WM) brain structures using diffusion MRI (dMRI) tractography frequently require manual WM bundle segmentation, often called “virtual dissection.” Human errors and personal decisions make these manual segmentations hard to reproduce, which have not yet been quantified by the dMRI community. It is our opinion that if the field of dMRI tractography wants to be taken seriously as a widespread clinical tool, it is imperative to harmonize WM bundle segmentations and develop protocols aimed to be used in clinical settings. The EADC‐ADNI Harmonized Hippocampal Protocol achieved such standardization through a series of steps that must be reproduced for every WM bundle. This article is an observation of the problematic. A specific bundle segmentation protocol was used in order to provide a real‐life example, but the contribution of this article is to discuss the need for reproducibility and standardized protocol, as for any measurement tool. This study required the participation of 11 experts and 13 nonexperts in neuroanatomy and “virtual dissection” across various laboratories and hospitals. Intra‐rater agreement (Dice score) was approximately 0.77, while inter‐rater was approximately 0.65. The protocol provided to participants was not necessarily optimal, but its design mimics, in essence, what will be required in future protocols. Reporting tractometry results such as average fractional anisotropy, volume or streamline count of a particular bundle without a sufficient reproducibility score could make the analysis and interpretations more difficult. Coordinated efforts by the diffusion MRI tractography community are needed to quantify and account for reproducibility of WM bundle extraction protocols in this era of open and collaborative science.