Impact of Pancreatic Enzymes on Enteral Fat and Nitrogen Absorption in Short Bowel Syndrome.

OBJECTIVES: Patients with short bowel syndrome (SBS) can have a high morbidity rate. To minimize morbidity, enteral autonomy is the primary goal in clinical management of patients with SBS. This is often difficult to achieve because of significant malabsorption. To date, there are limited therapies that improve absorption in patients with SBS. The impact of pancreatic enzyme replacement treatment on enteral absorption has not been studied in this population and was the primary aim of this study. SUBJECTS/METHODS: This was an interventional study in 11 subjects (6 pediatric subjects ages 4.0-17.9 years, 5 adult subjects 18-75 years) that compared enteral absorption in each subject before and after pancreatic enzyme medication (Creon). Coefficient of fat absorption (CFA) and coefficient of nitrogen absorption (CNA) were used as markers of enteral absorption of fat and protein, respectively. RESULTS: There was no statistically significant mean change in CFA and CNA before and after pancreatic enzyme medication therapy. Six subjects demonstrated an increase in CFA and 8 subjects demonstrated an increase in CNA after the use of pancreatic enzyme medication therapy. CONCLUSIONS: There was no statistically significant improvement in enteral fat and protein absorption in the cohort as a whole, though several subjects demonstrated an improvement. These results suggest that some patients with SBS may benefit from treatment with pancreatic enzymes. Further studies are needed to better evaluate the effect of pancreatic enzyme therapy on enteral absorption in subjects with SBS and to characterize factors that may predict a positive response.

The effect of HTLV1 infection on inflammatory and oxidative parameters in the liver, kidney, and pancreases of BALB/c mice.

Viral infections are linked to the progression of inflammatory reactions and oxidative stress that play pivotal roles in systemic diseases. To confirm this phenomenon, in the present study, TNF-α level and oxidative stress markers were examined in the liver, kidney, and pancreas of HTLV1-infected male BALB/c mice. To this end, twenty BALB/c mice were divided into HTLV1-infected mice that were inoculated with 1-million HTLV1-infected cells (MT-2), and the control groups. Two months after inoculation, the peripheral blood, mesenteric lymph nodes, liver, kidney, and pancreas were collected after deep anesthetization of mice (ketamine, 30 mg/kg). The extracted DNA of mesenteric lymph nodes was obtained to quantify proviral load (PVL) using quantitative real-time polymerase chain reaction (qRT-PCR). The levels of lipid peroxidation, total thiol (SH), nitric oxide (NO), TNF-α, catalase (CAT), and superoxide dismutase (SOD) activities were examined in the liver, kidney, and pancreases. Furthermore, histopathological changes in the liver and kidney were evaluated. In liver tissue, the levels of MDA, TNF-α, and blood cell infiltration were significantly increased, and the levels of CAT and SOD were significantly decreased. In the kidney, a reduction in SOD, CAT, and total SH and an increase in MDA and NO were observed. In the pancreas, CAT activity, total SH, and SOD were decreased, and the levels of MDA and NO were enhanced. In terms of TNF-α production, it has been shown that the level of this inflammatory cytokine was increased in the liver, kidney, and pancreas. The HTLV1 may have a role in inducing inflammatory reactions and oxidative stress pathways in the tissues.

Pancreatic lipase inhibitory constituents from Fructus Psoraleae.

Pancreatic lipase (PL), a crucial enzyme in the digestive system of mammals, has been proven as a therapeutic target to prevent and treat obesity. The purpose of this study is to evaluate and characterize the PL inhibition activities of the major constituents from Fructus Psoraleae (FP), one of the most frequently used Chinese herbs with lipid-lowering activity. To this end, a total of eleven major constituents isolated from Fructus Psoraleae have been obtained and their inhibition potentials against PL have been assayed by a fluorescence-based assay. Among all tested compounds, isobavachalcone, bavachalcone and corylifol A displayed strong inhibition on PL (IC50 < 10 µmol·L-1). Inhibition kinetic analyses demonstrated that isobavachalcone, bavachalcone and corylifol A acted as mixed inhibitors against PL-mediated 4-methylumbelliferyl oleate (4-MUO) hydrolysis, with the Ki values of 1.61, 3.77 and 10.16 µmol·L-1, respectively. Furthermore, docking simulations indicated that two chalcones (isobavachalcone and bavachalcone) could interact with the key residues located in the catalytic cavity of PL via hydrogen binding and hydrophobic interactions. Collectively, these finding provided solid evidence to support that Fructus Psoraleae contained bioactive compounds with lipid-lowering effects via targeting PL, and also suggested that the chalcones in Fructus Psoraleae could be used as ideal leading compounds to develop novel PL inhibitors.

Pancreatic Function in Chronic Pancreatitis: A Cohort Study Comparing 3 Methods of Detecting Fat Malabsorption and the Impact of Short-term Pancreatic Enzyme Replacement Therapy.

OBJECTIVES: Reliable pancreatic function tests in patients with chronic pancreatitis (CP) are needed. This cohort study identified malabsorption in people with CP compared with healthy people and then investigated short-term pancreatic enzyme replacement therapy (PERT) and fat malabsorption, nutritional status, and quality of life (QOL). METHODS: Subjects with CP were evaluated before and after PERT and compared with the healthy cohort using coefficient of fat absorption (CFA), stool bomb calorimetry, and the malabsorption blood test (MBT). Anthropometrics, micronutrients, and QOL data were collected. Group means at baseline and after PERT were analyzed. RESULTS: The 24 subjects with CP had greater stool energy loss (5668 cal/g [standard deviation {SD}, 753] vs 5152 cal/g [SD, 418], P < 0.01), reduced triglyceride absorption (MBT, 8.3 mg·h/dL [SD, 4.3] vs 17.7 mg·h/dL [SD, 10.3], P < 0.001), lower fat intake, and poorer QOL. Differences in CFA were not significant (90.9% [SD, 12.8] vs 95.4% [SD, 9.3]). After PERT, triglyceride absorption (Δ = 1.7 [SD, 3], P < 0.05) and QOL increased. CONCLUSIONS: The MBT detected changes in triglyceride absorption in the absence of CFA changes. The MBT may be helpful in guiding PERT initiation in patients with CP before significant morbidity.

Enzyme Promiscuity as a Remedy for the Common Problems with Knoevenagel Condensation.

A new protocol based on lipase-catalyzed tandem reaction toward α,ß-enones/enoesters is presented. For the synthesis of the desired products the tandem process based on enzyme-catalyzed hydrolysis and Knoevenagel reaction starting from enol acetates and aldehyde is developed. The relevant impact of the reaction conditions including organic solvent, enzyme type, and temperature on the course of the reaction was revealed. It was shown that controllable release of the active methylene compound from the corresponding enol carboxylate ensured by enzymatic reaction diminishes significantly the formation of the unwanted co-products. Furthermore, this protocol was extended by including a second tandem chemoenzymatic transformation engaging various aldehyde precursors. After a careful optimization of the reaction conditions, the target products were obtained with yields up to 86 % and with excellent E/Z-selectivity.

Characterisation and antidiabetic utility of a novel hybrid peptide, exendin-4/gastrin/xenin-8-Gln.

Enteroendocrine derived hormones such as glucagon-like-peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), gastrin and xenin are known to exert complementary beneficial metabolic effects in diabetes. This study has assessed the biological activity and therapeutic utility of a novel GLP-1/gastrin/xenin hybrid peptide, namely exendin-4/gastrin/xenin-8-Gln hybrid, both alone and in combination with the stable GIP mimetic, (DAla2)GIP. Exendin-4/gastrin/xenin-8-Gln increased in vitro insulin secretion to a similar or superior extent, as the parent peptides. Insulinotropic effects were mainly linked to modulation of GLP-1 and neurotensin receptors. Exendin-4/gastrin/xenin-8-Gln also augmented the insulinotropic actions of (DAla2)GIP. Acute administration of exendin-4/gastrin/xenin-8-Gln in mice induced significant appetite suppressive, glucose lowering and insulin secretory effects, with a duration of biological action beyond 8 h. Twice daily administration of exendin-4, exendin-4/gastrin/xenin-8-Gln, either alone or in combination with (DAla2)GIP, reduced circulating glucose, increased plasma insulin as well as improving glucose tolerance, insulin sensitivity and metabolic response to GIP in high fat fed mice. Body weight, food intake, circulating glucagon and amylase activity were unaltered. All hybrid peptide treated high fat mice exhibited marked reductions in LDL-cholesterol and body fat mass. Energy expenditure and locomotor activity were increased in mice treated with exendin-4/gastrin/xenin-8-Gln in combination with (DAla2)GIP. Interestingly, exendin-4 and exendin-4/gastrin/xenin-8-Gln treatment, but not exendin-4/gastrin/xenin-8-Gln in combination with (DAla2)GIP, reduced pancreatic islet and beta-cell area when compared to high fat controls. These studies confirm that unimolecular multi-agonist peptide hormones exert beneficial metabolic effects in diabetes, highlighting their potential as novel treatment strategies.

Use of an In-line Digestive Cartridge With Enteral Nutrition Improves the Weight Trajectory of 2 Children With Cystic Fibrosis Complicated by Another Medical Diagnosis.

This clinical observation describes the enteral nutrition (EN) management of 2 toddlers at high nutrition risk due to cystic fibrosis (CF), exocrine pancreatic insufficiency, and comorbid medical conditions. The first case report describes a boy with severe malabsorption after intestinal resection. The second case report reviews a boy with CF and neuroblastoma. When pancreatic enzyme replacement therapy with EN was not effective or appropriate, use of an in-line digestive cartridge was initiated. While using the digestive cartridge, both children showed improvements in their anthropometric measures. This observation reviews the nutrition management throughout their clinical course and describes the use of a digestive cartridge with EN.

Caco-2 Cell Conditions Enabling Studies of Drug Absorption from Digestible Lipid-Based Formulations.

PURPOSE: To identify conditions allowing the use of cell-based models for studies of drug absorption during in vitro lipolysis of lipid-based formulations (LBFs). METHODS: Caco-2 was selected as the cell-based model system. Monolayer integrity was evaluated by measuring mannitol permeability after incubating Caco-2 cells in the presence of components available during lipolysis. Pure excipients and formulations representing the lipid formulation classification system (LFCS) were evaluated before and after digestion. Porcine mucin was evaluated for its capacity to protect the cell monolayer. RESULTS: Most undigested formulations were compatible with the cells (II-LC, IIIB-LC, and IV) although some needed mucin to protect against damaging effects (II-MC, IIIB-MC, I-LC, and IIIA-LC). The pancreatic extract commonly used in digestion studies was incompatible with the cells but the Caco-2 monolayers could withstand immobilized recombinant lipase. Upon digestion, long chain formulations caused more damage to Caco-2 cells than their undigested counterparts whereas medium chain formulations showed better tolerability after digestion. CONCLUSIONS: Most LBFs and components thereof (undigested and digested) are compatible with Caco-2 cells. Pancreatic enzyme is not tolerated by the cells but immobilized lipase can be used in combination with the cell monolayer. Mucin is beneficial for critical formulations and digestion products.

[Effect of Electroacupuncture at "Weiwanxiashu" (EX-B 3) on Islet Morphology and the Expression of Pancreatic Glucagon-like Peptide-1 Receptor in Type 2 Diabetes Rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on pancreatic glucagon-like peptide-1 receptor (GLP-1 R), pancreatic and duodenal homeobox 1 (PDX-1) protein expression and blood glucose in type 2 diabetes rats, so as to explore the underlying mechanism of EA treatment in improving type 2 diabetes. METHODS: Sprague-Dawley rats were randomly divided into blank control group, model group, "Weiwanxiashu" (EX-B 3) group, "Xinshu" (BL 15) group, and "Shenshu" (BL 23) group, 12 rats in each group. Diabetes model was established by feeding the rat with high fat and high sugar diet combined with intraperitoneal injection of streptozotocin (35 mg/kg). All the EA groups received 2 Hz, 2 mA continuous wave treatment for 20 min everyday, 6 times per week lasting for 4 weeks. Fasting blood glucose was measured by Roche glucometer before and after treatment. Hematoxylin and eosin (HE) staining and Masson staining were used to detect pancreas morphology. GLP-1 R and PDX-1 protein expressions in the pancreas were detected by Western blot. RESULTS: Compared to the blank control group, fasting blood glucose was significantly increased in the model group(P<0.01), accompanied with shrunken islet area, reduced nucleus counts of islet ß cells, and compensatorily enlarged ß cell nucleus. Compared to the model group, EA intervention significantly reduced fasting blood glucose level only in the EX-B 3 group (P<0.05), partly restored pancreas morphology and nucleus counts of islet ß cells in the EX-B 3, BL 15, and BL 23 groups. Compared to the blank control group, GLP-1 R and PDX-1 expressions were decreased in the model group (P<0.01), while EA treatment could obviously increase GLP-1 R expression in the EX-B 3(P<0.01), BL 15 (P<0.01) and BL 23 (P<0.05) groups compared with the model group. The expression of GLP-1 R in the BL 15 group was the highest among the three EA groups (P<0.05,P<0.01), and that in the EX-B 3 group was higher than in the BL 23 group (P<0.05).There were no signifincant differences in the expression of PDX-1 protein among the three EA groups (P>0.05). CONCLUSIONS: EA treatment at EX-B 3 can reduce blood glucose via regulating pancreas function, increasing pancreatic GLP-1 R expression, and partly restoring the morphology of pancreas.

Transgenerational pancreatic impairment with Igf2/H19 epigenetic alteration induced by p,p'-DDE exposure in early life.

The hypothesis of fetal origins indicates that exposures in early development could induce epigenetic modifications in the male germ-line, affecting the susceptibility of adult-onset disease for generations. p,p'-DDE, the primary metabolite of persistent organochlorine pesticide DDT, is highly correlated with impaired glucose tolerance (IGT) and a strong contributing factor to type 2 diabetes. In our previous study, ancestral p,p'-DDE exposure could induce transgenerational impaired male fertility with sperm Igf2 hypomethylation. It is still unknown whether this germline epigenetic defect would affect the somatic tissue endocrine pancreas. Gestating F0 generation females were exposed to p,p'-DDE from gestation day 8 to 15. The F1 male offspring were mated with female to produce F2 progeny. F3 generation was obtained by intercrossing the control and treated male and female of F2 generation and divided as C♂-C♀, DDE♂-DDE♀, DDE♂-C♀ and C♂-DDE♀. Results indicated that F1 offspring in p,p'-DDE group exhibited impaired glucose tolerance (IGT), abnormal insulin secretion, ß-cell dysfunction and altered Igf2 and H19 expression induced by Igf2/H19 hypomethylation, which could be transferred to the F3 offspring through the male germ line. IGT and abnormal insulin secretion were more obvious in males than those in females. Ancestral p,p'-DDE exposure could induce transgenerational pancreatic impairment with Igf2/H19 epigenetic defect.

Antilipase and antiproliferative activities of novel fluoroquinolones and triazolofluoroquinolones.

Fluoroquinolones (FQs) have been identified recently as potent inhibitors of pancreatic lipase (PL). The aim of this study was to synthesize novel FQs and triazolofluoroquinolones (TFQs) and to evaluate them in vitro with respect to their antilipolytic efficacy and potency properties. The PL-IC50 values of 12 FQs and TFQs (3 (a-c)-6 (a-c)) were in the range of 12.5-189.1 µm. These values are further supported by docking studies. The suggested association between obesity and colorectal cancer initiated the evaluation of antiproliferative activity of the new FQs and TFQs against a panel of obesity-related colorectal cells (HT29, HCT116, SW620 CACO2, and SW480). Sulforodamine B colorimetric assay revealed that some derivatives exhibited unselective cytotoxicity against HT29, HCT116, SW620 CACO2, and SW480. Remarkably, FQ 4a's selective cytotoxicity against HCT116 was found valuable with IC50 value of 4.2 µm which exceeds that of cisplatin with a substantial selective cytotoxicity in periodontal ligament fibroblasts. In conclusion, FQ and TFQ derivatives may unveil new antiobesity and anticancer agents in the future.

Simulating Intestinal Transporter and Enzyme Activity in a Physiologically Based Pharmacokinetic Model for Tenofovir Disoproxil Fumarate.

Tenofovir disoproxil fumarate (TDF), a prodrug of tenofovir, has oral bioavailability (25%) limited by intestinal transport (P-glycoprotein), and intestinal degradation (carboxylesterase). However, the influence of luminal pancreatic enzymes is not fully understood. Physiologically based pharmacokinetic (PBPK) modeling has utility for estimating drug exposure from in vitro data. This study aimed to develop a PBPK model that included luminal enzyme activity to inform dose reduction strategies. TDF and tenofovir stability in porcine pancrelipase concentrations was assessed (0, 0.48, 4.8, 48, and 480 U/ml of lipase; 1 mM TDF; 37°C; 0 to 30 min). Samples were analyzed using mass spectrometry. TDF stability and permeation data allowed calculation of absorption rates within a human PBPK model to predict plasma exposure following 6 days of once-daily dosing with 300 mg of TDF. Regional absorption of drug was simulated across gut segments. TDF was degraded by pancrelipase (half-lives of 0.07 and 0.62 h using 480 and 48 U/ml, respectively). Previously reported maximum concentration (Cmax; 335 ng/ml), time to Cmax (Tmax; 2.4 h), area under the concentration-time curve from 0 to 24 h (AUC0-24; 3,045 ng · h/ml), and concentration at 24 h (C24; 48.3 ng/ml) were all within a 0.5-fold difference from the simulated Cmax (238 ng/ml), Tmax (3 h), AUC0-24 (3,036 ng · h/ml), and C24 (42.7 ng/ml). Simulated TDF absorption was higher in duodenum and jejunum than in ileum (p<0.05). These data support that TDF absorption is limited by the action of intestinal lipases. Our results suggest that bioavailability may be improved by protection of drug from intestinal transporters and enzymes, for example, by coadministration of enzyme-inhibiting agents or nanoformulation strategies.

BIRC7 and KLF4 expression in benign and malignant lesions of pancreas and their clinicopathological significance.

This study investigated the KLF4 and BIRC7 protein expression in malignant and benign pancreatic tissues by immunohistochemical staining and the clinical and pathological significance of KLF4 and BIRC7 expression in PDAC. KLF4 expression was significantly lower, whereas BIRC7 expression was significantly higher in PDAC than that in peritumoral tissue, benign pancreatic lesions, and normal pancreatic tissue (P < 0.01). The percentage of positive BIRC7 and negative KLF4 expression was significantly lower in PDAC patients with well differentiated tumors, maximum tumor size < 3 cm, no lymph node metastasis, no invasion to the surrounding tissues and organs, and TNM stage I/II stage disease than in patients with poorly differentiated tumor, maximum tumor size > 5 cm, lymph node metastasis, invasion to surrounding tissues and organs, and TNM stage III/IV disease (P < 0.05 or P < 0.01). Kaplan-Meier survival analysis showed that the differentiation, maximum tumor size, TNM stage, lymph node metastasis, invasion, negative KLF4 expression, and positive BIRC7 expression were significantly associated with the short survival of patients with PDAC (P < 0.05 or P < 0.01). Cox multivariate analysis revealed that positive BIRC7 expression and negative KLF4 expression were independent poor prognosis factors in PDAC patients. In conclusions, positive BIRC7 expression and negative KLF4 expression are associated with the progression of PDAC and poor prognosis in patients with PDAC.

Sensitivity profile of the human EndoC-ßH1 beta cell line to proinflammatory cytokines.

AIMS/HYPOTHESIS: The aim of this study was to perform a detailed analysis of cytokine toxicity in the new human EndoC-ßH1 beta cell line. METHODS: The expression profile of the antioxidative enzymes in the new human EndoC-ßH1 beta cells was characterised and compared with that of primary beta cells in the human pancreas. The effects of proinflammatory cytokines on reactive oxygen species formation, insulin secretory responsiveness and apoptosis of EndoC-ßH1 beta cells were determined. RESULTS: EndoC-ßH1 beta cells were sensitive to the toxic action of proinflammatory cytokines. Glucose-dependent stimulation of insulin secretion and an increase in the ATP/ADP ratio was abolished by proinflammatory cytokines without induction of IL-1ß expression. Cytokine-mediated caspase-3 activation was accompanied by reactive oxygen species formation and developed more slowly than in rodent beta cells. Cytokines transiently increased the expression of unfolded protein response genes, without inducing endoplasmic reticulum stress-marker genes. Cytokine-mediated NFκB activation was too weak to induce inducible nitric oxide synthase expression. The resultant lack of nitric oxide generation in EndoC-ßH1 cells, in contrast to rodent beta cells, makes these cells dependent on exogenously generated nitric oxide, which is released from infiltrating immune cells in human type 1 diabetes, for full expression of proinflammatory cytokine toxicity. CONCLUSIONS/INTERPRETATION: EndoC-ßH1 beta cells are characterised by an imbalance between H2O2-generating and -inactivating enzymes, and react to cytokine exposure in a similar manner to primary human beta cells. They are a suitable beta cell surrogate for cytokine-toxicity studies.

Evaluation of the recombinant turkey pancreatic lipase phospholipase activity: A monolayer study.

Classical lipases are well known for being enzymes hydrolysing triacylglycérols as substrate, except the porcine pancreatic lipase (PPL) which was able to hydrolyze phosphatidylcholine. Amino acid sequence alignments revealed that Valine 260 residue in PPL lid, postulated to be responsible for the PPL phospholipase activity, was present in the Turkey pancreatic lipase (TPL). The importance of Val 260 in the phospholipase activities expression has been reported. To confirm this fact, Val 260 was mutated to Alanine in the TPL lid. Mutated protein has conserved its phospholipase activity as well as the non mutated TPL. Therefore, Valine 260 residue in the lid is not involved in the pancreatic lipases phospholipase activity. The rTPL phospholipase activity was also studied using monolayer technique. This avian pancreatic lipase has shown phospholipase activity toward differently charged phospholipids. The highest phospholipase activity was found on phosphatidylglycerol (negatively charged substrate) at a surface pressure of 20mN/m, but when a zwitterionic substrate was used (DLPC), a lower activity was found at a surface pressure of 10mN/m. However, it is worth noticing that the TPL phospholipase activity is about 100 fold lower than its lipase activity. GC chromatography analyses of the released fatty acids from the hydrolysis of 1,2-POPC have shown that rTPL hydrolyses esters bonds at the sn-1 as well as the sn-2 position of phospholipids. Hence, rTPL shows a low phospholipase activity in comparison to its activity toward triacylglycerols.

Molecular interactions between (-)-epigallocatechin gallate analogs and pancreatic lipase.

The molecular interactions between pancreatic lipase (PL) and four tea polyphenols (EGCG analogs), like (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin (EC), were studied from PL activity, conformation, kinetics and thermodynamics. It was observed that EGCG analogs inhibited PL activity, and their inhibitory rates decreased by the order of EGCG>GCG>ECG>EC. PL activity at first decreased rapidly and then slowly with the increase of EGCG analogs concentrations. α-Helix content of PL secondary structure decreased dependent on EGCG analogs concentration by the order of EGCG>GCG>ECG>EC. EGCG, ECG, and EC could quench PL fluorescence both dynamically and statically, while GCG only quenched statically. EGCG analogs would induce PL self-assembly into complexes and the hydrodynamic radii of the complexes possessed a close relationship with the inhibitory rates. Kinetics analysis showed that EGCG analogs non-competitively inhibited PL activity and did not bind to PL catalytic site. DSC measurement revealed that EGCG analogs decreased the transition midpoint temperature of PL enzyme, suggesting that these compounds reduced PL enzyme thermostability. In vitro renaturation through urea solution indicated that interactions between PL and EGCG analogs were weak and non-covalent.

Disruption of protein-tyrosine phosphatase 1B expression in the pancreas affects ß-cell function.

Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and energy balance. However, the role of PTP1B in pancreatic endocrine function remains largely unknown. To investigate the metabolic role of pancreatic PTP1B, we generated mice with pancreas PTP1B deletion (panc-PTP1B KO). Mice were fed regular chow or a high-fat diet, and metabolic parameters, insulin secretion and glucose tolerance were determined. On regular chow, panc-PTP1B KO and control mice exhibited comparable glucose tolerance whereas aged panc-PTP1B KO exhibited mild glucose intolerance. Furthermore, high-fat feeding promoted earlier impairment of glucose tolerance and attenuated glucose-stimulated insulin secretion in panc-PTP1B KO mice. The secretory defect in glucose-stimulated insulin secretion was recapitulated in primary islets ex vivo, suggesting that the effects were likely cell-autonomous. At the molecular level, PTP1B deficiency in vivo enhanced basal and glucose-stimulated tyrosyl phosphorylation of EphA5 in islets. Consistently, PTP1B overexpression in the glucose-responsive MIN6 ß-cell line attenuated EphA5 tyrosyl phosphorylation, and substrate trapping identified EphA5 as a PTP1B substrate. In summary, these studies identify a novel role for PTP1B in pancreatic endocrine function.

Comparison of various solutions to dissolve critical care diet clots.

BACKGROUND: Enteral feeding tubes are frequently placed in animals to provide assisted nutritional support; however, one major reported complication is clogging of the tubes. The goal of this study was to determine which solution is most effective at dissolving in vitro clots made using a veterinary canned critical care diet. METHODS: Various solutions were tested for their ability to dissolve enteral feed clots, including water, meat tenderizers in water, predetermined amounts of pancreatic enzymes (with and without sodium bicarbonate) in water, carbonated beverages, and cranberry juice. RESULTS: The solution that resulted in the greatest dissolution was » teaspoon pancreatic enzymes and 325 mg sodium bicarbonate in 5 mL water, which was significantly better than all other solutions (water: P = 0.03; » teaspoon pancreatic enzymes in water: P = 0.002; all others: P < 0.001). Water was significantly better than all carbonated beverages and cranberry juice (P < 0.001). The least successful solution was ½ teaspoon pancreatic enzymes and sodium bicarbonate in water. CLINICAL RELEVANCE: Despite anecdotal reports of using carbonated beverages, cranberry juice, and ½ teaspoon pancreatic enzymes to unclog feeding tubes, all were significantly less effective than water. In vivo studies to evaluate the effectiveness of methods to unclog feeding tubes are warranted to further investigate these findings.

Liver iron and serum ferritin levels are misleading for estimating cardiac, pancreatic, splenic and total body iron load in thalassemia patients: factors influencing the heterogenic distribution of excess storage iron in organs as identified by MRI T2*.

A comparative assessment of excess storage iron distribution in the liver, heart, spleen and pancreas of ß-thalassemia major (ß-ΤΜ) patients has been carried out using magnetic resonance imaging (MRI) relaxation times T2*. The ß-ΤΜ patients (8-40 years, 11 males, 9 females) had variable serum ferritin levels (394-5603 µg/L) and were treated with deferoxamine (n = 10), deferiprone (n = 5) and deferoxamine/deferiprone combination (n = 5). MRI T2* assessment revealed that excess iron is not proportionally distributed among the organs but is stored at different concentrations in each organ and the distribution is different for each ß-ΤΜ patient. There is random variation in the distribution of excess storage iron from normal to severe levels in each organ among the ß-ΤΜ patients by comparison to the same organs of ten normal volunteers. The correlation of serum ferritin with T2* was for spleen (r = -0.81), liver (r = -0.63), pancreas (r = -0.33) and none with heart. Similar trend was observed in the correlation of liver T2* with the T2* of spleen (r = 0.62), pancreas (r = 0.61) and none with heart. These studies contradict previous assumptions that serum ferritin and liver iron concentration is proportional to the total body iron stores in ß-ΤΜ and especially cardiac iron load. The random variation in the concentration of iron in the organs of ß-ΤΜ patients appears to be related to the chelation protocol, organ function, genetic, dietary, pharmacological and other factors. Monitoring of the iron load for all the organs is recommended for each ß-ΤΜ patient.